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Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block

Browse source 
Pull block driver updates from Jens Axboe:
 "It might look big in volume, but when categorized, not a lot of
  drivers are touched.  The pull request contains:

   - mtip32xx fixes from Micron.

   - A slew of drbd updates, this time in a nicer series.

   - bcache, a flash/ssd caching framework from Kent.

   - Fixes for cciss"

* 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits)
  bcache: Use bd_link_disk_holder()
  bcache: Allocator cleanup/fixes
  cciss: bug fix to prevent cciss from loading in kdump crash kernel
  cciss: add cciss_allow_hpsa module parameter
  drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions
  mtip32xx: Workaround for unaligned writes
  bcache: Make sure blocksize isn't smaller than device blocksize
  bcache: Fix merge_bvec_fn usage for when it modifies the bvm
  bcache: Correctly check against BIO_MAX_PAGES
  bcache: Hack around stuff that clones up to bi_max_vecs
  bcache: Set ra_pages based on backing device's ra_pages
  bcache: Take data offset from the bdev superblock.
  mtip32xx: mtip32xx: Disable TRIM support
  mtip32xx: fix a smatch warning
  bcache: Disable broken btree fuzz tester
  bcache: Fix a format string overflow
  bcache: Fix a minor memory leak on device teardown
  bcache: Documentation updates
  bcache: Use WARN_ONCE() instead of __WARN()
  bcache: Add missing #include <linux/prefetch.h>
  ...
This commit is contained in:
Linus Torvalds 2013-05-08 11:51:05 -07:00
commit ebb3727779
62 changed files with 17685 additions and 376 deletions
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156
Documentation/ABI/testing/sysfs-block-bcache Normal file
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@ -0,0 +1,156 @@
What: /sys/block/<disk>/bcache/unregister
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
A write to this file causes the backing device or cache to be
unregistered. If a backing device had dirty data in the cache,
writeback mode is automatically disabled and all dirty data is
flushed before the device is unregistered. Caches unregister
all associated backing devices before unregistering themselves.
What: /sys/block/<disk>/bcache/clear_stats
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
Writing to this file resets all the statistics for the device.
What: /sys/block/<disk>/bcache/cache
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a backing device that has cache, a symlink to
the bcache/ dir of that cache.
What: /sys/block/<disk>/bcache/cache_hits
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: integer number of full cache hits,
counted per bio. A partial cache hit counts as a miss.
What: /sys/block/<disk>/bcache/cache_misses
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: integer number of cache misses.
What: /sys/block/<disk>/bcache/cache_hit_ratio
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: cache hits as a percentage.
What: /sys/block/<disk>/bcache/sequential_cutoff
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: Threshold past which sequential IO will
skip the cache. Read and written as bytes in human readable
units (i.e. echo 10M > sequntial_cutoff).
What: /sys/block/<disk>/bcache/bypassed
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
Sum of all reads and writes that have bypassed the cache (due
to the sequential cutoff). Expressed as bytes in human
readable units.
What: /sys/block/<disk>/bcache/writeback
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: When on, writeback caching is enabled and
writes will be buffered in the cache. When off, caching is in
writethrough mode; reads and writes will be added to the
cache but no write buffering will take place.
What: /sys/block/<disk>/bcache/writeback_running
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: when off, dirty data will not be written
from the cache to the backing device. The cache will still be
used to buffer writes until it is mostly full, at which point
writes transparently revert to writethrough mode. Intended only
for benchmarking/testing.
What: /sys/block/<disk>/bcache/writeback_delay
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: In writeback mode, when dirty data is
written to the cache and the cache held no dirty data for that
backing device, writeback from cache to backing device starts
after this delay, expressed as an integer number of seconds.
What: /sys/block/<disk>/bcache/writeback_percent
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For backing devices: If nonzero, writeback from cache to
backing device only takes place when more than this percentage
of the cache is used, allowing more write coalescing to take
place and reducing total number of writes sent to the backing
device. Integer between 0 and 40.
What: /sys/block/<disk>/bcache/synchronous
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, a boolean that allows synchronous mode to be
switched on and off. In synchronous mode all writes are ordered
such that the cache can reliably recover from unclean shutdown;
if disabled bcache will not generally wait for writes to
complete but if the cache is not shut down cleanly all data
will be discarded from the cache. Should not be turned off with
writeback caching enabled.
What: /sys/block/<disk>/bcache/discard
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, a boolean allowing discard/TRIM to be turned off
or back on if the device supports it.
What: /sys/block/<disk>/bcache/bucket_size
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, bucket size in human readable units, as set at
cache creation time; should match the erase block size of the
SSD for optimal performance.
What: /sys/block/<disk>/bcache/nbuckets
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, the number of usable buckets.
What: /sys/block/<disk>/bcache/tree_depth
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, height of the btree excluding leaf nodes (i.e. a
one node tree will have a depth of 0).
What: /sys/block/<disk>/bcache/btree_cache_size
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
Number of btree buckets/nodes that are currently cached in
memory; cache dynamically grows and shrinks in response to
memory pressure from the rest of the system.
What: /sys/block/<disk>/bcache/written
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, total amount of data in human readable units
written to the cache, excluding all metadata.
What: /sys/block/<disk>/bcache/btree_written
Date: November 2010
Contact: Kent Overstreet <kent.overstreet@gmail.com>
Description:
For a cache, sum of all btree writes in human readable units.

431
Documentation/bcache.txt Normal file
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@ -0,0 +1,431 @@
Say you've got a big slow raid 6, and an X-25E or three. Wouldn't it be
nice if you could use them as cache... Hence bcache.
Wiki and git repositories are at:
http://bcache.evilpiepirate.org
http://evilpiepirate.org/git/linux-bcache.git
http://evilpiepirate.org/git/bcache-tools.git
It's designed around the performance characteristics of SSDs - it only allocates
in erase block sized buckets, and it uses a hybrid btree/log to track cached
extants (which can be anywhere from a single sector to the bucket size). It's
designed to avoid random writes at all costs; it fills up an erase block
sequentially, then issues a discard before reusing it.
Both writethrough and writeback caching are supported. Writeback defaults to
off, but can be switched on and off arbitrarily at runtime. Bcache goes to
great lengths to protect your data - it reliably handles unclean shutdown. (It
doesn't even have a notion of a clean shutdown; bcache simply doesn't return
writes as completed until they're on stable storage).
Writeback caching can use most of the cache for buffering writes - writing
dirty data to the backing device is always done sequentially, scanning from the
start to the end of the index.
Since random IO is what SSDs excel at, there generally won't be much benefit
to caching large sequential IO. Bcache detects sequential IO and skips it;
it also keeps a rolling average of the IO sizes per task, and as long as the
average is above the cutoff it will skip all IO from that task - instead of
caching the first 512k after every seek. Backups and large file copies should
thus entirely bypass the cache.
In the event of a data IO error on the flash it will try to recover by reading
from disk or invalidating cache entries. For unrecoverable errors (meta data
or dirty data), caching is automatically disabled; if dirty data was present
in the cache it first disables writeback caching and waits for all dirty data
to be flushed.
Getting started:
You'll need make-bcache from the bcache-tools repository. Both the cache device
and backing device must be formatted before use.
make-bcache -B /dev/sdb
make-bcache -C /dev/sdc
make-bcache has the ability to format multiple devices at the same time - if
you format your backing devices and cache device at the same time, you won't
have to manually attach:
make-bcache -B /dev/sda /dev/sdb -C /dev/sdc
To make bcache devices known to the kernel, echo them to /sys/fs/bcache/register:
echo /dev/sdb > /sys/fs/bcache/register
echo /dev/sdc > /sys/fs/bcache/register
To register your bcache devices automatically, you could add something like
this to an init script:
echo /dev/sd* > /sys/fs/bcache/register_quiet
It'll look for bcache superblocks and ignore everything that doesn't have one.
Registering the backing device makes the bcache show up in /dev; you can now
format it and use it as normal. But the first time using a new bcache device,
it'll be running in passthrough mode until you attach it to a cache. See the
section on attaching.
The devices show up at /dev/bcacheN, and can be controlled via sysfs from
/sys/block/bcacheN/bcache:
mkfs.ext4 /dev/bcache0
mount /dev/bcache0 /mnt
Cache devices are managed as sets; multiple caches per set isn't supported yet
but will allow for mirroring of metadata and dirty data in the future. Your new
cache set shows up as /sys/fs/bcache/<UUID>
ATTACHING:
After your cache device and backing device are registered, the backing device
must be attached to your cache set to enable caching. Attaching a backing
device to a cache set is done thusly, with the UUID of the cache set in
/sys/fs/bcache:
echo <UUID> > /sys/block/bcache0/bcache/attach
This only has to be done once. The next time you reboot, just reregister all
your bcache devices. If a backing device has data in a cache somewhere, the
/dev/bcache# device won't be created until the cache shows up - particularly
important if you have writeback caching turned on.
If you're booting up and your cache device is gone and never coming back, you
can force run the backing device:
echo 1 > /sys/block/sdb/bcache/running
(You need to use /sys/block/sdb (or whatever your backing device is called), not
/sys/block/bcache0, because bcache0 doesn't exist yet. If you're using a
partition, the bcache directory would be at /sys/block/sdb/sdb2/bcache)
The backing device will still use that cache set if it shows up in the future,
but all the cached data will be invalidated. If there was dirty data in the
cache, don't expect the filesystem to be recoverable - you will have massive
filesystem corruption, though ext4's fsck does work miracles.
ERROR HANDLING:
Bcache tries to transparently handle IO errors to/from the cache device without
affecting normal operation; if it sees too many errors (the threshold is
configurable, and defaults to 0) it shuts down the cache device and switches all
the backing devices to passthrough mode.
- For reads from the cache, if they error we just retry the read from the
backing device.
- For writethrough writes, if the write to the cache errors we just switch to
invalidating the data at that lba in the cache (i.e. the same thing we do for
a write that bypasses the cache)
- For writeback writes, we currently pass that error back up to the
filesystem/userspace. This could be improved - we could retry it as a write
that skips the cache so we don't have to error the write.
- When we detach, we first try to flush any dirty data (if we were running in
writeback mode). It currently doesn't do anything intelligent if it fails to
read some of the dirty data, though.
TROUBLESHOOTING PERFORMANCE:
Bcache has a bunch of config options and tunables. The defaults are intended to
be reasonable for typical desktop and server workloads, but they're not what you
want for getting the best possible numbers when benchmarking.
- Bad write performance
If write performance is not what you expected, you probably wanted to be
running in writeback mode, which isn't the default (not due to a lack of
maturity, but simply because in writeback mode you'll lose data if something
happens to your SSD)
# echo writeback > /sys/block/bcache0/cache_mode
- Bad performance, or traffic not going to the SSD that you'd expect
By default, bcache doesn't cache everything. It tries to skip sequential IO -
because you really want to be caching the random IO, and if you copy a 10
gigabyte file you probably don't want that pushing 10 gigabytes of randomly
accessed data out of your cache.
But if you want to benchmark reads from cache, and you start out with fio
writing an 8 gigabyte test file - so you want to disable that.
# echo 0 > /sys/block/bcache0/bcache/sequential_cutoff
To set it back to the default (4 mb), do
# echo 4M > /sys/block/bcache0/bcache/sequential_cutoff
- Traffic's still going to the spindle/still getting cache misses
In the real world, SSDs don't always keep up with disks - particularly with
slower SSDs, many disks being cached by one SSD, or mostly sequential IO. So
you want to avoid being bottlenecked by the SSD and having it slow everything
down.
To avoid that bcache tracks latency to the cache device, and gradually
throttles traffic if the latency exceeds a threshold (it does this by
cranking down the sequential bypass).
You can disable this if you need to by setting the thresholds to 0:
# echo 0 > /sys/fs/bcache/<cache set>/congested_read_threshold_us
# echo 0 > /sys/fs/bcache/<cache set>/congested_write_threshold_us
The default is 2000 us (2 milliseconds) for reads, and 20000 for writes.
- Still getting cache misses, of the same data
One last issue that sometimes trips people up is actually an old bug, due to
the way cache coherency is handled for cache misses. If a btree node is full,
a cache miss won't be able to insert a key for the new data and the data
won't be written to the cache.
In practice this isn't an issue because as soon as a write comes along it'll
cause the btree node to be split, and you need almost no write traffic for
this to not show up enough to be noticable (especially since bcache's btree
nodes are huge and index large regions of the device). But when you're
benchmarking, if you're trying to warm the cache by reading a bunch of data
and there's no other traffic - that can be a problem.
Solution: warm the cache by doing writes, or use the testing branch (there's
a fix for the issue there).
SYSFS - BACKING DEVICE:
attach
Echo the UUID of a cache set to this file to enable caching.
cache_mode
Can be one of either writethrough, writeback, writearound or none.
clear_stats
Writing to this file resets the running total stats (not the day/hour/5 minute
decaying versions).
detach
Write to this file to detach from a cache set. If there is dirty data in the
cache, it will be flushed first.
dirty_data
Amount of dirty data for this backing device in the cache. Continuously
updated unlike the cache set's version, but may be slightly off.
label
Name of underlying device.
readahead
Size of readahead that should be performed. Defaults to 0. If set to e.g.
1M, it will round cache miss reads up to that size, but without overlapping
existing cache entries.
running
1 if bcache is running (i.e. whether the /dev/bcache device exists, whether
it's in passthrough mode or caching).
sequential_cutoff
A sequential IO will bypass the cache once it passes this threshhold; the
most recent 128 IOs are tracked so sequential IO can be detected even when
it isn't all done at once.
sequential_merge
If non zero, bcache keeps a list of the last 128 requests submitted to compare
against all new requests to determine which new requests are sequential
continuations of previous requests for the purpose of determining sequential
cutoff. This is necessary if the sequential cutoff value is greater than the
maximum acceptable sequential size for any single request.
state
The backing device can be in one of four different states:
no cache: Has never been attached to a cache set.
clean: Part of a cache set, and there is no cached dirty data.
dirty: Part of a cache set, and there is cached dirty data.
inconsistent: The backing device was forcibly run by the user when there was
dirty data cached but the cache set was unavailable; whatever data was on the
backing device has likely been corrupted.
stop
Write to this file to shut down the bcache device and close the backing
device.
writeback_delay
When dirty data is written to the cache and it previously did not contain
any, waits some number of seconds before initiating writeback. Defaults to
30.
writeback_percent
If nonzero, bcache tries to keep around this percentage of the cache dirty by
throttling background writeback and using a PD controller to smoothly adjust
the rate.
writeback_rate
Rate in sectors per second - if writeback_percent is nonzero, background
writeback is throttled to this rate. Continuously adjusted by bcache but may
also be set by the user.
writeback_running
If off, writeback of dirty data will not take place at all. Dirty data will
still be added to the cache until it is mostly full; only meant for
benchmarking. Defaults to on.
SYSFS - BACKING DEVICE STATS:
There are directories with these numbers for a running total, as well as
versions that decay over the past day, hour and 5 minutes; they're also
aggregated in the cache set directory as well.
bypassed
Amount of IO (both reads and writes) that has bypassed the cache
cache_hits
cache_misses
cache_hit_ratio
Hits and misses are counted per individual IO as bcache sees them; a
partial hit is counted as a miss.
cache_bypass_hits
cache_bypass_misses
Hits and misses for IO that is intended to skip the cache are still counted,
but broken out here.
cache_miss_collisions
Counts instances where data was going to be inserted into the cache from a
cache miss, but raced with a write and data was already present (usually 0
since the synchronization for cache misses was rewritten)
cache_readaheads
Count of times readahead occured.
SYSFS - CACHE SET:
average_key_size
Average data per key in the btree.
bdev<0..n>
Symlink to each of the attached backing devices.
block_size
Block size of the cache devices.
btree_cache_size
Amount of memory currently used by the btree cache
bucket_size
Size of buckets
cache<0..n>
Symlink to each of the cache devices comprising this cache set.
cache_available_percent
Percentage of cache device free.
clear_stats
Clears the statistics associated with this cache
dirty_data
Amount of dirty data is in the cache (updated when garbage collection runs).
flash_vol_create
Echoing a size to this file (in human readable units, k/M/G) creates a thinly
provisioned volume backed by the cache set.
io_error_halflife
io_error_limit
These determines how many errors we accept before disabling the cache.
Each error is decayed by the half life (in # ios). If the decaying count
reaches io_error_limit dirty data is written out and the cache is disabled.
journal_delay_ms
Journal writes will delay for up to this many milliseconds, unless a cache
flush happens sooner. Defaults to 100.
root_usage_percent
Percentage of the root btree node in use. If this gets too high the node
will split, increasing the tree depth.
stop
Write to this file to shut down the cache set - waits until all attached
backing devices have been shut down.
tree_depth
Depth of the btree (A single node btree has depth 0).
unregister
Detaches all backing devices and closes the cache devices; if dirty data is
present it will disable writeback caching and wait for it to be flushed.
SYSFS - CACHE SET INTERNAL:
This directory also exposes timings for a number of internal operations, with
separate files for average duration, average frequency, last occurence and max
duration: garbage collection, btree read, btree node sorts and btree splits.
active_journal_entries
Number of journal entries that are newer than the index.
btree_nodes
Total nodes in the btree.
btree_used_percent
Average fraction of btree in use.
bset_tree_stats
Statistics about the auxiliary search trees
btree_cache_max_chain
Longest chain in the btree node cache's hash table
cache_read_races
Counts instances where while data was being read from the cache, the bucket
was reused and invalidated - i.e. where the pointer was stale after the read
completed. When this occurs the data is reread from the backing device.
trigger_gc
Writing to this file forces garbage collection to run.
SYSFS - CACHE DEVICE:
block_size
Minimum granularity of writes - should match hardware sector size.
btree_written
Sum of all btree writes, in (kilo/mega/giga) bytes
bucket_size
Size of buckets
cache_replacement_policy
One of either lru, fifo or random.
discard
Boolean; if on a discard/TRIM will be issued to each bucket before it is
reused. Defaults to off, since SATA TRIM is an unqueued command (and thus
slow).
freelist_percent
Size of the freelist as a percentage of nbuckets. Can be written to to
increase the number of buckets kept on the freelist, which lets you
artificially reduce the size of the cache at runtime. Mostly for testing
purposes (i.e. testing how different size caches affect your hit rate), but
since buckets are discarded when they move on to the freelist will also make
the SSD's garbage collection easier by effectively giving it more reserved
space.
io_errors
Number of errors that have occured, decayed by io_error_halflife.
metadata_written
Sum of all non data writes (btree writes and all other metadata).
nbuckets
Total buckets in this cache
priority_stats
Statistics about how recently data in the cache has been accessed. This can
reveal your working set size.
written
Sum of all data that has been written to the cache; comparison with
btree_written gives the amount of write inflation in bcache.

7
MAINTAINERS
View file

@ -1620,6 +1620,13 @@ W: http://www.baycom.org/~tom/ham/ham.html
S: Maintained
F: drivers/net/hamradio/baycom*
BCACHE (BLOCK LAYER CACHE)
M: Kent Overstreet <koverstreet@google.com>
L: linux-bcache@vger.kernel.org
W: http://bcache.evilpiepirate.org
S: Maintained:
F: drivers/md/bcache/
BEFS FILE SYSTEM
S: Orphan
F: Documentation/filesystems/befs.txt

6
drivers/block/aoe/aoecmd.c
View file

@ -920,16 +920,14 @@ bio_pagedec(struct bio *bio)
static void
bufinit(struct buf *buf, struct request *rq, struct bio *bio)
{
struct bio_vec *bv;
memset(buf, 0, sizeof(*buf));
buf->rq = rq;
buf->bio = bio;
buf->resid = bio->bi_size;
buf->sector = bio->bi_sector;
bio_pageinc(bio);
buf->bv = bv = bio_iovec(bio);
buf->bv_resid = bv->bv_len;
buf->bv = bio_iovec(bio);
buf->bv_resid = buf->bv->bv_len;
WARN_ON(buf->bv_resid == 0);
}

22
drivers/block/cciss.c
View file

@ -75,6 +75,12 @@ module_param(cciss_simple_mode, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(cciss_simple_mode,
"Use 'simple mode' rather than 'performant mode'");
static int cciss_allow_hpsa;
module_param(cciss_allow_hpsa, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(cciss_allow_hpsa,
"Prevent cciss driver from accessing hardware known to be "
" supported by the hpsa driver");
static DEFINE_MUTEX(cciss_mutex);
static struct proc_dir_entry *proc_cciss;
@ -4115,9 +4121,13 @@ static int cciss_lookup_board_id(struct pci_dev *pdev, u32 *board_id)
*board_id = ((subsystem_device_id << 16) & 0xffff0000) |
subsystem_vendor_id;
for (i = 0; i < ARRAY_SIZE(products); i++)
for (i = 0; i < ARRAY_SIZE(products); i++) {
/* Stand aside for hpsa driver on request */
if (cciss_allow_hpsa)
return -ENODEV;
if (*board_id == products[i].board_id)
return i;
}
dev_warn(&pdev->dev, "unrecognized board ID: 0x%08x, ignoring.\n",
*board_id);
return -ENODEV;
@ -4959,6 +4969,16 @@ static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
ctlr_info_t *h;
unsigned long flags;
/*
* By default the cciss driver is used for all older HP Smart Array
* controllers. There are module paramaters that allow a user to
* override this behavior and instead use the hpsa SCSI driver. If
* this is the case cciss may be loaded first from the kdump initrd
* image and cause a kernel panic. So if reset_devices is true and
* cciss_allow_hpsa is set just bail.
*/
if ((reset_devices) && (cciss_allow_hpsa == 1))
return -ENODEV;
rc = cciss_init_reset_devices(pdev);
if (rc) {
if (rc != -ENOTSUPP)

246
drivers/block/drbd/drbd_actlog.c
View file

@ -104,7 +104,6 @@ struct update_al_work {
int err;
};
static int al_write_transaction(struct drbd_conf *mdev);
void *drbd_md_get_buffer(struct drbd_conf *mdev)
{
@ -168,7 +167,11 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
bio->bi_end_io = drbd_md_io_complete;
bio->bi_rw = rw;
if (!get_ldev_if_state(mdev, D_ATTACHING)) { /* Corresponding put_ldev in drbd_md_io_complete() */
if (!(rw & WRITE) && mdev->state.disk == D_DISKLESS && mdev->ldev == NULL)
/* special case, drbd_md_read() during drbd_adm_attach(): no get_ldev */
;
else if (!get_ldev_if_state(mdev, D_ATTACHING)) {
/* Corresponding put_ldev in drbd_md_io_complete() */
dev_err(DEV, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n");
err = -ENODEV;
goto out;
@ -199,9 +202,10 @@ int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
BUG_ON(!bdev->md_bdev);
dev_dbg(DEV, "meta_data io: %s [%d]:%s(,%llus,%s)\n",
dev_dbg(DEV, "meta_data io: %s [%d]:%s(,%llus,%s) %pS\n",
current->comm, current->pid, __func__,
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ",
(void*)_RET_IP_ );
if (sector < drbd_md_first_sector(bdev) ||
sector + 7 > drbd_md_last_sector(bdev))
@ -209,7 +213,8 @@ int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
current->comm, current->pid, __func__,
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, MD_BLOCK_SIZE);
/* we do all our meta data IO in aligned 4k blocks. */
err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, 4096);
if (err) {
dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n",
(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ", err);
@ -217,44 +222,99 @@ int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
return err;
}
static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr)
static struct bm_extent *find_active_resync_extent(struct drbd_conf *mdev, unsigned int enr)
{
struct lc_element *al_ext;
struct lc_element *tmp;
int wake;
spin_lock_irq(&mdev->al_lock);
tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
if (unlikely(tmp != NULL)) {
struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
spin_unlock_irq(&mdev->al_lock);
if (wake)
wake_up(&mdev->al_wait);
return NULL;
}
if (test_bit(BME_NO_WRITES, &bm_ext->flags))
return bm_ext;
}
al_ext = lc_get(mdev->act_log, enr);
return NULL;
}
static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr, bool nonblock)
{
struct lc_element *al_ext;
struct bm_extent *bm_ext;
int wake;
spin_lock_irq(&mdev->al_lock);
bm_ext = find_active_resync_extent(mdev, enr);
if (bm_ext) {
wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
spin_unlock_irq(&mdev->al_lock);
if (wake)
wake_up(&mdev->al_wait);
return NULL;
}
if (nonblock)
al_ext = lc_try_get(mdev->act_log, enr);
else
al_ext = lc_get(mdev->act_log, enr);
spin_unlock_irq(&mdev->al_lock);
return al_ext;
}
void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i)
bool drbd_al_begin_io_fastpath(struct drbd_conf *mdev, struct drbd_interval *i)
{
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
D_ASSERT((unsigned)(last - first) <= 1);
D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
/* FIXME figure out a fast path for bios crossing AL extent boundaries */
if (first != last)
return false;
return _al_get(mdev, first, true);
}
bool drbd_al_begin_io_prepare(struct drbd_conf *mdev, struct drbd_interval *i)
{
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
unsigned enr;
bool locked = false;
bool need_transaction = false;
D_ASSERT(first <= last);
D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
for (enr = first; enr <= last; enr++)
wait_event(mdev->al_wait, _al_get(mdev, enr) != NULL);
for (enr = first; enr <= last; enr++) {
struct lc_element *al_ext;
wait_event(mdev->al_wait,
(al_ext = _al_get(mdev, enr, false)) != NULL);
if (al_ext->lc_number != enr)
need_transaction = true;
}
return need_transaction;
}
static int al_write_transaction(struct drbd_conf *mdev, bool delegate);
/* When called through generic_make_request(), we must delegate
* activity log I/O to the worker thread: a further request
* submitted via generic_make_request() within the same task
* would be queued on current->bio_list, and would only start
* after this function returns (see generic_make_request()).
*
* However, if we *are* the worker, we must not delegate to ourselves.
*/
/*
* @delegate: delegate activity log I/O to the worker thread
*/
void drbd_al_begin_io_commit(struct drbd_conf *mdev, bool delegate)
{
bool locked = false;
BUG_ON(delegate && current == mdev->tconn->worker.task);
/* Serialize multiple transactions.
* This uses test_and_set_bit, memory barrier is implicit.
@ -264,13 +324,6 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i)
(locked = lc_try_lock_for_transaction(mdev->act_log)));
if (locked) {
/* drbd_al_write_transaction(mdev,al_ext,enr);
* recurses into generic_make_request(), which
* disallows recursion, bios being serialized on the
* current->bio_tail list now.
* we have to delegate updates to the activity log
* to the worker thread. */
/* Double check: it may have been committed by someone else,
* while we have been waiting for the lock. */
if (mdev->act_log->pending_changes) {
@ -280,11 +333,8 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i)
write_al_updates = rcu_dereference(mdev->ldev->disk_conf)->al_updates;
rcu_read_unlock();
if (write_al_updates) {
al_write_transaction(mdev);
mdev->al_writ_cnt++;
}
if (write_al_updates)
al_write_transaction(mdev, delegate);
spin_lock_irq(&mdev->al_lock);
/* FIXME
if (err)
@ -298,6 +348,66 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i)
}
}
/*
* @delegate: delegate activity log I/O to the worker thread
*/
void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i, bool delegate)
{
BUG_ON(delegate && current == mdev->tconn->worker.task);
if (drbd_al_begin_io_prepare(mdev, i))
drbd_al_begin_io_commit(mdev, delegate);
}
int drbd_al_begin_io_nonblock(struct drbd_conf *mdev, struct drbd_interval *i)
{
struct lru_cache *al = mdev->act_log;
/* for bios crossing activity log extent boundaries,
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
unsigned nr_al_extents;
unsigned available_update_slots;
unsigned enr;
D_ASSERT(first <= last);
nr_al_extents = 1 + last - first; /* worst case: all touched extends are cold. */
available_update_slots = min(al->nr_elements - al->used,
al->max_pending_changes - al->pending_changes);
/* We want all necessary updates for a given request within the same transaction
* We could first check how many updates are *actually* needed,
* and use that instead of the worst-case nr_al_extents */
if (available_update_slots < nr_al_extents)
return -EWOULDBLOCK;
/* Is resync active in this area? */
for (enr = first; enr <= last; enr++) {
struct lc_element *tmp;
tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
if (unlikely(tmp != NULL)) {
struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
if (!test_and_set_bit(BME_PRIORITY, &bm_ext->flags))
return -EBUSY;
return -EWOULDBLOCK;
}
}
}
/* Checkout the refcounts.
* Given that we checked for available elements and update slots above,
* this has to be successful. */
for (enr = first; enr <= last; enr++) {
struct lc_element *al_ext;
al_ext = lc_get_cumulative(mdev->act_log, enr);
if (!al_ext)
dev_info(DEV, "LOGIC BUG for enr=%u\n", enr);
}
return 0;
}
void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i)
{
/* for bios crossing activity log extent boundaries,
@ -350,6 +460,24 @@ static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
(BM_EXT_SHIFT - BM_BLOCK_SHIFT));
}
static sector_t al_tr_number_to_on_disk_sector(struct drbd_conf *mdev)
{
const unsigned int stripes = mdev->ldev->md.al_stripes;
const unsigned int stripe_size_4kB = mdev->ldev->md.al_stripe_size_4k;
/* transaction number, modulo on-disk ring buffer wrap around */
unsigned int t = mdev->al_tr_number % (mdev->ldev->md.al_size_4k);
/* ... to aligned 4k on disk block */
t = ((t % stripes) * stripe_size_4kB) + t/stripes;
/* ... to 512 byte sector in activity log */
t *= 8;
/* ... plus offset to the on disk position */
return mdev->ldev->md.md_offset + mdev->ldev->md.al_offset + t;
}
static int
_al_write_transaction(struct drbd_conf *mdev)
{
@ -432,23 +560,27 @@ _al_write_transaction(struct drbd_conf *mdev)
if (mdev->al_tr_cycle >= mdev->act_log->nr_elements)
mdev->al_tr_cycle = 0;
sector = mdev->ldev->md.md_offset
+ mdev->ldev->md.al_offset
+ mdev->al_tr_pos * (MD_BLOCK_SIZE>>9);
sector = al_tr_number_to_on_disk_sector(mdev);
crc = crc32c(0, buffer, 4096);
buffer->crc32c = cpu_to_be32(crc);
if (drbd_bm_write_hinted(mdev))
err = -EIO;
/* drbd_chk_io_error done already */
else if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
err = -EIO;
drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
} else {
/* advance ringbuffer position and transaction counter */
mdev->al_tr_pos = (mdev->al_tr_pos + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
mdev->al_tr_number++;
else {
bool write_al_updates;
rcu_read_lock();
write_al_updates = rcu_dereference(mdev->ldev->disk_conf)->al_updates;
rcu_read_unlock();
if (write_al_updates) {
if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
err = -EIO;
drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
} else {
mdev->al_tr_number++;
mdev->al_writ_cnt++;
}
}
}
drbd_md_put_buffer(mdev);
@ -474,20 +606,18 @@ static int w_al_write_transaction(struct drbd_work *w, int unused)
/* Calls from worker context (see w_restart_disk_io()) need to write the
transaction directly. Others came through generic_make_request(),
those need to delegate it to the worker. */
static int al_write_transaction(struct drbd_conf *mdev)
static int al_write_transaction(struct drbd_conf *mdev, bool delegate)
{
struct update_al_work al_work;
if (current == mdev->tconn->worker.task)
if (delegate) {
struct update_al_work al_work;
init_completion(&al_work.event);
al_work.w.cb = w_al_write_transaction;
al_work.w.mdev = mdev;
drbd_queue_work_front(&mdev->tconn->sender_work, &al_work.w);
wait_for_completion(&al_work.event);
return al_work.err;
} else
return _al_write_transaction(mdev);
init_completion(&al_work.event);
al_work.w.cb = w_al_write_transaction;
al_work.w.mdev = mdev;
drbd_queue_work_front(&mdev->tconn->sender_work, &al_work.w);
wait_for_completion(&al_work.event);
return al_work.err;
}
static int _try_lc_del(struct drbd_conf *mdev, struct lc_element *al_ext)

13
drivers/block/drbd/drbd_bitmap.c
View file

@ -612,6 +612,17 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
}
}
/* For the layout, see comment above drbd_md_set_sector_offsets(). */
static u64 drbd_md_on_disk_bits(struct drbd_backing_dev *ldev)
{
u64 bitmap_sectors;
if (ldev->md.al_offset == 8)
bitmap_sectors = ldev->md.md_size_sect - ldev->md.bm_offset;
else
bitmap_sectors = ldev->md.al_offset - ldev->md.bm_offset;
return bitmap_sectors << (9 + 3);
}
/*
* make sure the bitmap has enough room for the attached storage,
* if necessary, resize.
@ -668,7 +679,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits)
words = ALIGN(bits, 64) >> LN2_BPL;
if (get_ldev(mdev)) {
u64 bits_on_disk = ((u64)mdev->ldev->md.md_size_sect-MD_BM_OFFSET) << 12;
u64 bits_on_disk = drbd_md_on_disk_bits(mdev->ldev);
put_ldev(mdev);
if (bits > bits_on_disk) {
dev_info(DEV, "bits = %lu\n", bits);

179
drivers/block/drbd/drbd_int.h
View file

@ -753,13 +753,16 @@ struct drbd_md {
u32 flags;
u32 md_size_sect;
s32 al_offset; /* signed relative sector offset to al area */
s32 al_offset; /* signed relative sector offset to activity log */
s32 bm_offset; /* signed relative sector offset to bitmap */
/* u32 al_nr_extents; important for restoring the AL
* is stored into ldev->dc.al_extents, which in turn
* gets applied to act_log->nr_elements
*/
/* cached value of bdev->disk_conf->meta_dev_idx (see below) */
s32 meta_dev_idx;
/* see al_tr_number_to_on_disk_sector() */
u32 al_stripes;
u32 al_stripe_size_4k;
u32 al_size_4k; /* cached product of the above */
};
struct drbd_backing_dev {
@ -891,6 +894,14 @@ struct drbd_tconn { /* is a resource from the config file */
} send;
};
struct submit_worker {
struct workqueue_struct *wq;
struct work_struct worker;
spinlock_t lock;
struct list_head writes;
};
struct drbd_conf {
struct drbd_tconn *tconn;
int vnr; /* volume number within the connection */
@ -1009,7 +1020,6 @@ struct drbd_conf {
struct lru_cache *act_log; /* activity log */
unsigned int al_tr_number;
int al_tr_cycle;
int al_tr_pos; /* position of the next transaction in the journal */
wait_queue_head_t seq_wait;
atomic_t packet_seq;
unsigned int peer_seq;
@ -1032,6 +1042,10 @@ struct drbd_conf {
atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */
unsigned int peer_max_bio_size;
unsigned int local_max_bio_size;
/* any requests that would block in drbd_make_request()
* are deferred to this single-threaded work queue */
struct submit_worker submit;
};
static inline struct drbd_conf *minor_to_mdev(unsigned int minor)
@ -1148,25 +1162,44 @@ extern int drbd_bitmap_io_from_worker(struct drbd_conf *mdev,
char *why, enum bm_flag flags);
extern int drbd_bmio_set_n_write(struct drbd_conf *mdev);
extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev);
extern void drbd_go_diskless(struct drbd_conf *mdev);
extern void drbd_ldev_destroy(struct drbd_conf *mdev);
/* Meta data layout
We reserve a 128MB Block (4k aligned)
* either at the end of the backing device
* or on a separate meta data device. */
*
* We currently have two possible layouts.
* Offsets in (512 byte) sectors.
* external:
* |----------- md_size_sect ------------------|
* [ 4k superblock ][ activity log ][ Bitmap ]
* | al_offset == 8 |
* | bm_offset = al_offset + X |
* ==> bitmap sectors = md_size_sect - bm_offset
*
* Variants:
* old, indexed fixed size meta data:
*
* internal:
* |----------- md_size_sect ------------------|
* [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*]
* | al_offset < 0 |
* | bm_offset = al_offset - Y |
* ==> bitmap sectors = Y = al_offset - bm_offset
*
* [padding*] are zero or up to 7 unused 512 Byte sectors to the
* end of the device, so that the [4k superblock] will be 4k aligned.
*
* The activity log consists of 4k transaction blocks,
* which are written in a ring-buffer, or striped ring-buffer like fashion,
* which are writtensize used to be fixed 32kB,
* but is about to become configurable.
*/
/* The following numbers are sectors */
/* Allows up to about 3.8TB, so if you want more,
/* Our old fixed size meta data layout
* allows up to about 3.8TB, so if you want more,
* you need to use the "flexible" meta data format. */
#define MD_RESERVED_SECT (128LU << 11) /* 128 MB, unit sectors */
#define MD_AL_OFFSET 8 /* 8 Sectors after start of meta area */
#define MD_AL_SECTORS 64 /* = 32 kB on disk activity log ring buffer */
#define MD_BM_OFFSET (MD_AL_OFFSET + MD_AL_SECTORS)
/* we do all meta data IO in 4k blocks */
#define MD_BLOCK_SHIFT 12
#define MD_BLOCK_SIZE (1<<MD_BLOCK_SHIFT)
#define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */
#define MD_4kB_SECT 8
#define MD_32kB_SECT 64
/* One activity log extent represents 4M of storage */
#define AL_EXTENT_SHIFT 22
@ -1256,7 +1289,6 @@ struct bm_extent {
/* in one sector of the bitmap, we have this many activity_log extents. */
#define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT))
#define BM_WORDS_PER_AL_EXT (1 << (AL_EXTENT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL))
#define BM_BLOCKS_PER_BM_EXT_B (BM_EXT_SHIFT - BM_BLOCK_SHIFT)
#define BM_BLOCKS_PER_BM_EXT_MASK ((1<<BM_BLOCKS_PER_BM_EXT_B) - 1)
@ -1276,16 +1308,18 @@ struct bm_extent {
*/
#define DRBD_MAX_SECTORS_32 (0xffffffffLU)
#define DRBD_MAX_SECTORS_BM \
((MD_RESERVED_SECT - MD_BM_OFFSET) * (1LL<<(BM_EXT_SHIFT-9)))
#if DRBD_MAX_SECTORS_BM < DRBD_MAX_SECTORS_32
#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM
#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_BM
#elif !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
/* we have a certain meta data variant that has a fixed on-disk size of 128
* MiB, of which 4k are our "superblock", and 32k are the fixed size activity
* log, leaving this many sectors for the bitmap.
*/
#define DRBD_MAX_SECTORS_FIXED_BM \
((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9)))
#if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32
#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32
#else
#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM
#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_FIXED_BM
/* 16 TB in units of sectors */
#if BITS_PER_LONG == 32
/* adjust by one page worth of bitmap,
@ -1418,6 +1452,7 @@ extern void conn_free_crypto(struct drbd_tconn *tconn);
extern int proc_details;
/* drbd_req */
extern void do_submit(struct work_struct *ws);
extern void __drbd_make_request(struct drbd_conf *, struct bio *, unsigned long);
extern void drbd_make_request(struct request_queue *q, struct bio *bio);
extern int drbd_read_remote(struct drbd_conf *mdev, struct drbd_request *req);
@ -1576,7 +1611,10 @@ extern const char *drbd_conn_str(enum drbd_conns s);
extern const char *drbd_role_str(enum drbd_role s);
/* drbd_actlog.c */
extern void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i);
extern int drbd_al_begin_io_nonblock(struct drbd_conf *mdev, struct drbd_interval *i);
extern void drbd_al_begin_io_commit(struct drbd_conf *mdev, bool delegate);
extern bool drbd_al_begin_io_fastpath(struct drbd_conf *mdev, struct drbd_interval *i);
extern void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i, bool delegate);
extern void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i);
extern void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector);
extern int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector);
@ -1755,9 +1793,9 @@ static inline void drbd_chk_io_error_(struct drbd_conf *mdev,
* BTW, for internal meta data, this happens to be the maximum capacity
* we could agree upon with our peer node.
*/
static inline sector_t _drbd_md_first_sector(int meta_dev_idx, struct drbd_backing_dev *bdev)
static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev)
{
switch (meta_dev_idx) {
switch (bdev->md.meta_dev_idx) {
case DRBD_MD_INDEX_INTERNAL:
case DRBD_MD_INDEX_FLEX_INT:
return bdev->md.md_offset + bdev->md.bm_offset;
@ -1767,36 +1805,19 @@ static inline sector_t _drbd_md_first_sector(int meta_dev_idx, struct drbd_backi
}
}
static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev)
{
int meta_dev_idx;
rcu_read_lock();
meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx;
rcu_read_unlock();
return _drbd_md_first_sector(meta_dev_idx, bdev);
}
/**
* drbd_md_last_sector() - Return the last sector number of the meta data area
* @bdev: Meta data block device.
*/
static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
{
int meta_dev_idx;
rcu_read_lock();
meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx;
rcu_read_unlock();
switch (meta_dev_idx) {
switch (bdev->md.meta_dev_idx) {
case DRBD_MD_INDEX_INTERNAL:
case DRBD_MD_INDEX_FLEX_INT:
return bdev->md.md_offset + MD_AL_OFFSET - 1;
return bdev->md.md_offset + MD_4kB_SECT -1;
case DRBD_MD_INDEX_FLEX_EXT:
default:
return bdev->md.md_offset + bdev->md.md_size_sect;
return bdev->md.md_offset + bdev->md.md_size_sect -1;
}
}
@ -1818,18 +1839,13 @@ static inline sector_t drbd_get_capacity(struct block_device *bdev)
static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev)
{
sector_t s;
int meta_dev_idx;
rcu_read_lock();
meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx;
rcu_read_unlock();
switch (meta_dev_idx) {
switch (bdev->md.meta_dev_idx) {
case DRBD_MD_INDEX_INTERNAL:
case DRBD_MD_INDEX_FLEX_INT:
s = drbd_get_capacity(bdev->backing_bdev)
? min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
_drbd_md_first_sector(meta_dev_idx, bdev))
drbd_md_first_sector(bdev))
: 0;
break;
case DRBD_MD_INDEX_FLEX_EXT:
@ -1848,39 +1864,24 @@ static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev)
}
/**
* drbd_md_ss__() - Return the sector number of our meta data super block
* @mdev: DRBD device.
* drbd_md_ss() - Return the sector number of our meta data super block
* @bdev: Meta data block device.
*/
static inline sector_t drbd_md_ss__(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev)
static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev)
{
int meta_dev_idx;
const int meta_dev_idx = bdev->md.meta_dev_idx;
rcu_read_lock();
meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx;
rcu_read_unlock();
switch (meta_dev_idx) {
default: /* external, some index */
return MD_RESERVED_SECT * meta_dev_idx;
case DRBD_MD_INDEX_INTERNAL:
/* with drbd08, internal meta data is always "flexible" */
case DRBD_MD_INDEX_FLEX_INT:
/* sizeof(struct md_on_disk_07) == 4k
* position: last 4k aligned block of 4k size */
if (!bdev->backing_bdev) {
if (__ratelimit(&drbd_ratelimit_state)) {
dev_err(DEV, "bdev->backing_bdev==NULL\n");
dump_stack();
}
return 0;
}
return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL)
- MD_AL_OFFSET;
case DRBD_MD_INDEX_FLEX_EXT:
if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT)
return 0;
}
/* Since drbd08, internal meta data is always "flexible".
* position: last 4k aligned block of 4k size */
if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)
return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8;
/* external, some index; this is the old fixed size layout */
return MD_128MB_SECT * bdev->md.meta_dev_idx;
}
static inline void
@ -2053,9 +2054,11 @@ static inline void put_ldev(struct drbd_conf *mdev)
if (mdev->state.disk == D_DISKLESS)
/* even internal references gone, safe to destroy */
drbd_ldev_destroy(mdev);
if (mdev->state.disk == D_FAILED)
if (mdev->state.disk == D_FAILED) {
/* all application IO references gone. */
drbd_go_diskless(mdev);
if (!test_and_set_bit(GO_DISKLESS, &mdev->flags))
drbd_queue_work(&mdev->tconn->sender_work, &mdev->go_diskless);
}
wake_up(&mdev->misc_wait);
}
}

255
drivers/block/drbd/drbd_main.c
View file

@ -45,7 +45,7 @@
#include <linux/reboot.h>
#include <linux/notifier.h>
#include <linux/kthread.h>
#include <linux/workqueue.h>
#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include <linux/vmalloc.h>
@ -2299,6 +2299,7 @@ static void drbd_cleanup(void)
idr_for_each_entry(&minors, mdev, i) {
idr_remove(&minors, mdev_to_minor(mdev));
idr_remove(&mdev->tconn->volumes, mdev->vnr);
destroy_workqueue(mdev->submit.wq);
del_gendisk(mdev->vdisk);
/* synchronize_rcu(); No other threads running at this point */
kref_put(&mdev->kref, &drbd_minor_destroy);
@ -2588,6 +2589,21 @@ void conn_destroy(struct kref *kref)
kfree(tconn);
}
int init_submitter(struct drbd_conf *mdev)
{
/* opencoded create_singlethread_workqueue(),
* to be able to say "drbd%d", ..., minor */
mdev->submit.wq = alloc_workqueue("drbd%u_submit",
WQ_UNBOUND | WQ_MEM_RECLAIM, 1, mdev->minor);
if (!mdev->submit.wq)
return -ENOMEM;
INIT_WORK(&mdev->submit.worker, do_submit);
spin_lock_init(&mdev->submit.lock);
INIT_LIST_HEAD(&mdev->submit.writes);
return 0;
}
enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr)
{
struct drbd_conf *mdev;
@ -2677,6 +2693,12 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
goto out_idr_remove_minor;
}
if (init_submitter(mdev)) {
err = ERR_NOMEM;
drbd_msg_put_info("unable to create submit workqueue");
goto out_idr_remove_vol;
}
add_disk(disk);
kref_init(&mdev->kref); /* one ref for both idrs and the the add_disk */
@ -2687,6 +2709,8 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
return NO_ERROR;
out_idr_remove_vol:
idr_remove(&tconn->volumes, vnr_got);
out_idr_remove_minor:
idr_remove(&minors, minor_got);
synchronize_rcu();
@ -2794,6 +2818,7 @@ void drbd_free_bc(struct drbd_backing_dev *ldev)
blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
kfree(ldev->disk_conf);
kfree(ldev);
}
@ -2833,8 +2858,9 @@ void conn_md_sync(struct drbd_tconn *tconn)
rcu_read_unlock();
}
/* aligned 4kByte */
struct meta_data_on_disk {
u64 la_size; /* last agreed size. */
u64 la_size_sect; /* last agreed size. */
u64 uuid[UI_SIZE]; /* UUIDs. */
u64 device_uuid;
u64 reserved_u64_1;
@ -2842,13 +2868,17 @@ struct meta_data_on_disk {
u32 magic;
u32 md_size_sect;
u32 al_offset; /* offset to this block */
u32 al_nr_extents; /* important for restoring the AL */
u32 al_nr_extents; /* important for restoring the AL (userspace) */
/* `-- act_log->nr_elements <-- ldev->dc.al_extents */
u32 bm_offset; /* offset to the bitmap, from here */
u32 bm_bytes_per_bit; /* BM_BLOCK_SIZE */
u32 la_peer_max_bio_size; /* last peer max_bio_size */
u32 reserved_u32[3];
/* see al_tr_number_to_on_disk_sector() */
u32 al_stripes;
u32 al_stripe_size_4k;
u8 reserved_u8[4096 - (7*8 + 10*4)];
} __packed;
/**
@ -2861,6 +2891,10 @@ void drbd_md_sync(struct drbd_conf *mdev)
sector_t sector;
int i;
/* Don't accidentally change the DRBD meta data layout. */
BUILD_BUG_ON(UI_SIZE != 4);
BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
del_timer(&mdev->md_sync_timer);
/* timer may be rearmed by drbd_md_mark_dirty() now. */
if (!test_and_clear_bit(MD_DIRTY, &mdev->flags))
@ -2875,9 +2909,9 @@ void drbd_md_sync(struct drbd_conf *mdev)
if (!buffer)
goto out;
memset(buffer, 0, 512);
memset(buffer, 0, sizeof(*buffer));
buffer->la_size = cpu_to_be64(drbd_get_capacity(mdev->this_bdev));
buffer->la_size_sect = cpu_to_be64(drbd_get_capacity(mdev->this_bdev));
for (i = UI_CURRENT; i < UI_SIZE; i++)
buffer->uuid[i] = cpu_to_be64(mdev->ldev->md.uuid[i]);
buffer->flags = cpu_to_be32(mdev->ldev->md.flags);
@ -2892,7 +2926,10 @@ void drbd_md_sync(struct drbd_conf *mdev)
buffer->bm_offset = cpu_to_be32(mdev->ldev->md.bm_offset);
buffer->la_peer_max_bio_size = cpu_to_be32(mdev->peer_max_bio_size);
D_ASSERT(drbd_md_ss__(mdev, mdev->ldev) == mdev->ldev->md.md_offset);
buffer->al_stripes = cpu_to_be32(mdev->ldev->md.al_stripes);
buffer->al_stripe_size_4k = cpu_to_be32(mdev->ldev->md.al_stripe_size_4k);
D_ASSERT(drbd_md_ss(mdev->ldev) == mdev->ldev->md.md_offset);
sector = mdev->ldev->md.md_offset;
if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
@ -2910,13 +2947,141 @@ out:
put_ldev(mdev);
}
static int check_activity_log_stripe_size(struct drbd_conf *mdev,
struct meta_data_on_disk *on_disk,
struct drbd_md *in_core)
{
u32 al_stripes = be32_to_cpu(on_disk->al_stripes);
u32 al_stripe_size_4k = be32_to_cpu(on_disk->al_stripe_size_4k);
u64 al_size_4k;
/* both not set: default to old fixed size activity log */
if (al_stripes == 0 && al_stripe_size_4k == 0) {
al_stripes = 1;
al_stripe_size_4k = MD_32kB_SECT/8;
}
/* some paranoia plausibility checks */
/* we need both values to be set */
if (al_stripes == 0 || al_stripe_size_4k == 0)
goto err;
al_size_4k = (u64)al_stripes * al_stripe_size_4k;
/* Upper limit of activity log area, to avoid potential overflow
* problems in al_tr_number_to_on_disk_sector(). As right now, more
* than 72 * 4k blocks total only increases the amount of history,
* limiting this arbitrarily to 16 GB is not a real limitation ;-) */
if (al_size_4k > (16 * 1024 * 1024/4))
goto err;
/* Lower limit: we need at least 8 transaction slots (32kB)
* to not break existing setups */
if (al_size_4k < MD_32kB_SECT/8)
goto err;
in_core->al_stripe_size_4k = al_stripe_size_4k;
in_core->al_stripes = al_stripes;
in_core->al_size_4k = al_size_4k;
return 0;
err:
dev_err(DEV, "invalid activity log striping: al_stripes=%u, al_stripe_size_4k=%u\n",
al_stripes, al_stripe_size_4k);
return -EINVAL;
}
static int check_offsets_and_sizes(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
{
sector_t capacity = drbd_get_capacity(bdev->md_bdev);
struct drbd_md *in_core = &bdev->md;
s32 on_disk_al_sect;
s32 on_disk_bm_sect;
/* The on-disk size of the activity log, calculated from offsets, and
* the size of the activity log calculated from the stripe settings,
* should match.
* Though we could relax this a bit: it is ok, if the striped activity log
* fits in the available on-disk activity log size.
* Right now, that would break how resize is implemented.
* TODO: make drbd_determine_dev_size() (and the drbdmeta tool) aware
* of possible unused padding space in the on disk layout. */
if (in_core->al_offset < 0) {
if (in_core->bm_offset > in_core->al_offset)
goto err;
on_disk_al_sect = -in_core->al_offset;
on_disk_bm_sect = in_core->al_offset - in_core->bm_offset;
} else {
if (in_core->al_offset != MD_4kB_SECT)
goto err;
if (in_core->bm_offset < in_core->al_offset + in_core->al_size_4k * MD_4kB_SECT)
goto err;
on_disk_al_sect = in_core->bm_offset - MD_4kB_SECT;
on_disk_bm_sect = in_core->md_size_sect - in_core->bm_offset;
}
/* old fixed size meta data is exactly that: fixed. */
if (in_core->meta_dev_idx >= 0) {
if (in_core->md_size_sect != MD_128MB_SECT
|| in_core->al_offset != MD_4kB_SECT
|| in_core->bm_offset != MD_4kB_SECT + MD_32kB_SECT
|| in_core->al_stripes != 1
|| in_core->al_stripe_size_4k != MD_32kB_SECT/8)
goto err;
}
if (capacity < in_core->md_size_sect)
goto err;
if (capacity - in_core->md_size_sect < drbd_md_first_sector(bdev))
goto err;
/* should be aligned, and at least 32k */
if ((on_disk_al_sect & 7) || (on_disk_al_sect < MD_32kB_SECT))
goto err;
/* should fit (for now: exactly) into the available on-disk space;
* overflow prevention is in check_activity_log_stripe_size() above. */
if (on_disk_al_sect != in_core->al_size_4k * MD_4kB_SECT)
goto err;
/* again, should be aligned */
if (in_core->bm_offset & 7)
goto err;
/* FIXME check for device grow with flex external meta data? */
/* can the available bitmap space cover the last agreed device size? */
if (on_disk_bm_sect < (in_core->la_size_sect+7)/MD_4kB_SECT/8/512)
goto err;
return 0;
err:
dev_err(DEV, "meta data offsets don't make sense: idx=%d "
"al_s=%u, al_sz4k=%u, al_offset=%d, bm_offset=%d, "
"md_size_sect=%u, la_size=%llu, md_capacity=%llu\n",
in_core->meta_dev_idx,
in_core->al_stripes, in_core->al_stripe_size_4k,
in_core->al_offset, in_core->bm_offset, in_core->md_size_sect,
(unsigned long long)in_core->la_size_sect,
(unsigned long long)capacity);
return -EINVAL;
}
/**
* drbd_md_read() - Reads in the meta data super block
* @mdev: DRBD device.
* @bdev: Device from which the meta data should be read in.
*
* Return 0 (NO_ERROR) on success, and an enum drbd_ret_code in case
* Return NO_ERROR on success, and an enum drbd_ret_code in case
* something goes wrong.
*
* Called exactly once during drbd_adm_attach(), while still being D_DISKLESS,
* even before @bdev is assigned to @mdev->ldev.
*/
int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
{
@ -2924,12 +3089,17 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
u32 magic, flags;
int i, rv = NO_ERROR;
if (!get_ldev_if_state(mdev, D_ATTACHING))
return ERR_IO_MD_DISK;
if (mdev->state.disk != D_DISKLESS)
return ERR_DISK_CONFIGURED;
buffer = drbd_md_get_buffer(mdev);
if (!buffer)
goto out;
return ERR_NOMEM;
/* First, figure out where our meta data superblock is located,
* and read it. */
bdev->md.meta_dev_idx = bdev->disk_conf->meta_dev_idx;
bdev->md.md_offset = drbd_md_ss(bdev);
if (drbd_md_sync_page_io(mdev, bdev, bdev->md.md_offset, READ)) {
/* NOTE: can't do normal error processing here as this is
@ -2948,46 +3118,52 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
rv = ERR_MD_UNCLEAN;
goto err;
}
rv = ERR_MD_INVALID;
if (magic != DRBD_MD_MAGIC_08) {
if (magic == DRBD_MD_MAGIC_07)
dev_err(DEV, "Found old (0.7) meta data magic. Did you \"drbdadm create-md\"?\n");
else
dev_err(DEV, "Meta data magic not found. Did you \"drbdadm create-md\"?\n");
rv = ERR_MD_INVALID;
goto err;
}
if (be32_to_cpu(buffer->al_offset) != bdev->md.al_offset) {
dev_err(DEV, "unexpected al_offset: %d (expected %d)\n",
be32_to_cpu(buffer->al_offset), bdev->md.al_offset);
rv = ERR_MD_INVALID;
goto err;
}
if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
dev_err(DEV, "unexpected bm_offset: %d (expected %d)\n",
be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
rv = ERR_MD_INVALID;
goto err;
}
if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
dev_err(DEV, "unexpected md_size: %u (expected %u)\n",
be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
rv = ERR_MD_INVALID;
goto err;
}
if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) {
dev_err(DEV, "unexpected bm_bytes_per_bit: %u (expected %u)\n",
be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE);
rv = ERR_MD_INVALID;
goto err;
}
bdev->md.la_size_sect = be64_to_cpu(buffer->la_size);
/* convert to in_core endian */
bdev->md.la_size_sect = be64_to_cpu(buffer->la_size_sect);
for (i = UI_CURRENT; i < UI_SIZE; i++)
bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
bdev->md.flags = be32_to_cpu(buffer->flags);
bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);
bdev->md.md_size_sect = be32_to_cpu(buffer->md_size_sect);
bdev->md.al_offset = be32_to_cpu(buffer->al_offset);
bdev->md.bm_offset = be32_to_cpu(buffer->bm_offset);
if (check_activity_log_stripe_size(mdev, buffer, &bdev->md))
goto err;
if (check_offsets_and_sizes(mdev, bdev))
goto err;
if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
dev_err(DEV, "unexpected bm_offset: %d (expected %d)\n",
be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
goto err;
}
if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
dev_err(DEV, "unexpected md_size: %u (expected %u)\n",
be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
goto err;
}
rv = NO_ERROR;
spin_lock_irq(&mdev->tconn->req_lock);
if (mdev->state.conn < C_CONNECTED) {
unsigned int peer;
@ -2999,8 +3175,6 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
err:
drbd_md_put_buffer(mdev);
out:
put_ldev(mdev);
return rv;
}
@ -3238,8 +3412,12 @@ static int w_go_diskless(struct drbd_work *w, int unused)
* end up here after a failed attach, before ldev was even assigned.
*/
if (mdev->bitmap && mdev->ldev) {
/* An interrupted resync or similar is allowed to recounts bits
* while we detach.
* Any modifications would not be expected anymore, though.
*/
if (drbd_bitmap_io_from_worker(mdev, drbd_bm_write,
"detach", BM_LOCKED_MASK)) {
"detach", BM_LOCKED_TEST_ALLOWED)) {
if (test_bit(WAS_READ_ERROR, &mdev->flags)) {
drbd_md_set_flag(mdev, MDF_FULL_SYNC);
drbd_md_sync(mdev);
@ -3251,13 +3429,6 @@ static int w_go_diskless(struct drbd_work *w, int unused)
return 0;
}
void drbd_go_diskless(struct drbd_conf *mdev)
{
D_ASSERT(mdev->state.disk == D_FAILED);
if (!test_and_set_bit(GO_DISKLESS, &mdev->flags))
drbd_queue_work(&mdev->tconn->sender_work, &mdev->go_diskless);
}
/**
* drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap
* @mdev: DRBD device.

200
drivers/block/drbd/drbd_nl.c
View file

@ -696,37 +696,52 @@ out:
return 0;
}
/* initializes the md.*_offset members, so we are able to find
* the on disk meta data */
/* Initializes the md.*_offset members, so we are able to find
* the on disk meta data.
*
* We currently have two possible layouts:
* external:
* |----------- md_size_sect ------------------|
* [ 4k superblock ][ activity log ][ Bitmap ]
* | al_offset == 8 |
* | bm_offset = al_offset + X |
* ==> bitmap sectors = md_size_sect - bm_offset
*
* internal:
* |----------- md_size_sect ------------------|
* [data.....][ Bitmap ][ activity log ][ 4k superblock ]
* | al_offset < 0 |
* | bm_offset = al_offset - Y |
* ==> bitmap sectors = Y = al_offset - bm_offset
*
* Activity log size used to be fixed 32kB,
* but is about to become configurable.
*/
static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev)
{
sector_t md_size_sect = 0;
int meta_dev_idx;
unsigned int al_size_sect = bdev->md.al_size_4k * 8;
rcu_read_lock();
meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx;
bdev->md.md_offset = drbd_md_ss(bdev);
switch (meta_dev_idx) {
switch (bdev->md.meta_dev_idx) {
default:
/* v07 style fixed size indexed meta data */
bdev->md.md_size_sect = MD_RESERVED_SECT;
bdev->md.md_offset = drbd_md_ss__(mdev, bdev);
bdev->md.al_offset = MD_AL_OFFSET;
bdev->md.bm_offset = MD_BM_OFFSET;
bdev->md.md_size_sect = MD_128MB_SECT;
bdev->md.al_offset = MD_4kB_SECT;
bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
break;
case DRBD_MD_INDEX_FLEX_EXT:
/* just occupy the full device; unit: sectors */
bdev->md.md_size_sect = drbd_get_capacity(bdev->md_bdev);
bdev->md.md_offset = 0;
bdev->md.al_offset = MD_AL_OFFSET;
bdev->md.bm_offset = MD_BM_OFFSET;
bdev->md.al_offset = MD_4kB_SECT;
bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
break;
case DRBD_MD_INDEX_INTERNAL:
case DRBD_MD_INDEX_FLEX_INT:
bdev->md.md_offset = drbd_md_ss__(mdev, bdev);
/* al size is still fixed */
bdev->md.al_offset = -MD_AL_SECTORS;
bdev->md.al_offset = -al_size_sect;
/* we need (slightly less than) ~ this much bitmap sectors: */
md_size_sect = drbd_get_capacity(bdev->backing_bdev);
md_size_sect = ALIGN(md_size_sect, BM_SECT_PER_EXT);
@ -735,14 +750,13 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
/* plus the "drbd meta data super block",
* and the activity log; */
md_size_sect += MD_BM_OFFSET;
md_size_sect += MD_4kB_SECT + al_size_sect;
bdev->md.md_size_sect = md_size_sect;
/* bitmap offset is adjusted by 'super' block size */
bdev->md.bm_offset = -md_size_sect + MD_AL_OFFSET;
bdev->md.bm_offset = -md_size_sect + MD_4kB_SECT;
break;
}
rcu_read_unlock();
}
/* input size is expected to be in KB */
@ -805,7 +819,7 @@ void drbd_resume_io(struct drbd_conf *mdev)
enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *mdev, enum dds_flags flags) __must_hold(local)
{
sector_t prev_first_sect, prev_size; /* previous meta location */
sector_t la_size, u_size;
sector_t la_size_sect, u_size;
sector_t size;
char ppb[10];
@ -828,7 +842,7 @@ enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *mdev, enum dds
prev_first_sect = drbd_md_first_sector(mdev->ldev);
prev_size = mdev->ldev->md.md_size_sect;
la_size = mdev->ldev->md.la_size_sect;
la_size_sect = mdev->ldev->md.la_size_sect;
/* TODO: should only be some assert here, not (re)init... */
drbd_md_set_sector_offsets(mdev, mdev->ldev);
@ -864,7 +878,7 @@ enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *mdev, enum dds
if (rv == dev_size_error)
goto out;
la_size_changed = (la_size != mdev->ldev->md.la_size_sect);
la_size_changed = (la_size_sect != mdev->ldev->md.la_size_sect);
md_moved = prev_first_sect != drbd_md_first_sector(mdev->ldev)
|| prev_size != mdev->ldev->md.md_size_sect;
@ -886,9 +900,9 @@ enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *mdev, enum dds
drbd_md_mark_dirty(mdev);
}
if (size > la_size)
if (size > la_size_sect)
rv = grew;
if (size < la_size)
if (size < la_size_sect)
rv = shrunk;
out:
lc_unlock(mdev->act_log);
@ -903,7 +917,7 @@ drbd_new_dev_size(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
sector_t u_size, int assume_peer_has_space)
{
sector_t p_size = mdev->p_size; /* partner's disk size. */
sector_t la_size = bdev->md.la_size_sect; /* last agreed size. */
sector_t la_size_sect = bdev->md.la_size_sect; /* last agreed size. */
sector_t m_size; /* my size */
sector_t size = 0;
@ -917,8 +931,8 @@ drbd_new_dev_size(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
if (p_size && m_size) {
size = min_t(sector_t, p_size, m_size);
} else {
if (la_size) {
size = la_size;
if (la_size_sect) {
size = la_size_sect;
if (m_size && m_size < size)
size = m_size;
if (p_size && p_size < size)
@ -1127,15 +1141,32 @@ static bool should_set_defaults(struct genl_info *info)
return 0 != (flags & DRBD_GENL_F_SET_DEFAULTS);
}
static void enforce_disk_conf_limits(struct disk_conf *dc)
static unsigned int drbd_al_extents_max(struct drbd_backing_dev *bdev)
{
if (dc->al_extents < DRBD_AL_EXTENTS_MIN)
dc->al_extents = DRBD_AL_EXTENTS_MIN;
if (dc->al_extents > DRBD_AL_EXTENTS_MAX)
dc->al_extents = DRBD_AL_EXTENTS_MAX;
/* This is limited by 16 bit "slot" numbers,
* and by available on-disk context storage.
*
* Also (u16)~0 is special (denotes a "free" extent).
*
* One transaction occupies one 4kB on-disk block,
* we have n such blocks in the on disk ring buffer,
* the "current" transaction may fail (n-1),
* and there is 919 slot numbers context information per transaction.
*
* 72 transaction blocks amounts to more than 2**16 context slots,
* so cap there first.
*/
const unsigned int max_al_nr = DRBD_AL_EXTENTS_MAX;
const unsigned int sufficient_on_disk =
(max_al_nr + AL_CONTEXT_PER_TRANSACTION -1)
/AL_CONTEXT_PER_TRANSACTION;
if (dc->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
dc->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
unsigned int al_size_4k = bdev->md.al_size_4k;
if (al_size_4k > sufficient_on_disk)
return max_al_nr;
return (al_size_4k - 1) * AL_CONTEXT_PER_TRANSACTION;
}
int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
@ -1182,7 +1213,13 @@ int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
if (!expect(new_disk_conf->resync_rate >= 1))
new_disk_conf->resync_rate = 1;
enforce_disk_conf_limits(new_disk_conf);
if (new_disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
new_disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
if (new_disk_conf->al_extents > drbd_al_extents_max(mdev->ldev))
new_disk_conf->al_extents = drbd_al_extents_max(mdev->ldev);
if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ;
if (fifo_size != mdev->rs_plan_s->size) {
@ -1330,7 +1367,8 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
goto fail;
}
enforce_disk_conf_limits(new_disk_conf);
if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
new_plan = fifo_alloc((new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ);
if (!new_plan) {
@ -1343,6 +1381,12 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
goto fail;
}
write_lock_irq(&global_state_lock);
retcode = drbd_resync_after_valid(mdev, new_disk_conf->resync_after);
write_unlock_irq(&global_state_lock);
if (retcode != NO_ERROR)
goto fail;
rcu_read_lock();
nc = rcu_dereference(mdev->tconn->net_conf);
if (nc) {
@ -1399,8 +1443,16 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
goto fail;
}
/* RT - for drbd_get_max_capacity() DRBD_MD_INDEX_FLEX_INT */
drbd_md_set_sector_offsets(mdev, nbc);
/* Read our meta data super block early.
* This also sets other on-disk offsets. */
retcode = drbd_md_read(mdev, nbc);
if (retcode != NO_ERROR)
goto fail;
if (new_disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
new_disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
if (new_disk_conf->al_extents > drbd_al_extents_max(nbc))
new_disk_conf->al_extents = drbd_al_extents_max(nbc);
if (drbd_get_max_capacity(nbc) < new_disk_conf->disk_size) {
dev_err(DEV, "max capacity %llu smaller than disk size %llu\n",
@ -1416,7 +1468,7 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
min_md_device_sectors = (2<<10);
} else {
max_possible_sectors = DRBD_MAX_SECTORS;
min_md_device_sectors = MD_RESERVED_SECT * (new_disk_conf->meta_dev_idx + 1);
min_md_device_sectors = MD_128MB_SECT * (new_disk_conf->meta_dev_idx + 1);
}
if (drbd_get_capacity(nbc->md_bdev) < min_md_device_sectors) {
@ -1467,8 +1519,6 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
if (!get_ldev_if_state(mdev, D_ATTACHING))
goto force_diskless;
drbd_md_set_sector_offsets(mdev, nbc);
if (!mdev->bitmap) {
if (drbd_bm_init(mdev)) {
retcode = ERR_NOMEM;
@ -1476,10 +1526,6 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
}
}
retcode = drbd_md_read(mdev, nbc);
if (retcode != NO_ERROR)
goto force_diskless_dec;
if (mdev->state.conn < C_CONNECTED &&
mdev->state.role == R_PRIMARY &&
(mdev->ed_uuid & ~((u64)1)) != (nbc->md.uuid[UI_CURRENT] & ~((u64)1))) {
@ -2158,8 +2204,11 @@ static enum drbd_state_rv conn_try_disconnect(struct drbd_tconn *tconn, bool for
return SS_SUCCESS;
case SS_PRIMARY_NOP:
/* Our state checking code wants to see the peer outdated. */
rv = conn_request_state(tconn, NS2(conn, C_DISCONNECTING,
pdsk, D_OUTDATED), CS_VERBOSE);
rv = conn_request_state(tconn, NS2(conn, C_DISCONNECTING, pdsk, D_OUTDATED), 0);
if (rv == SS_OUTDATE_WO_CONN) /* lost connection before graceful disconnect succeeded */
rv = conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_VERBOSE);
break;
case SS_CW_FAILED_BY_PEER:
/* The peer probably wants to see us outdated. */
@ -2406,22 +2455,19 @@ int drbd_adm_invalidate(struct sk_buff *skb, struct genl_info *info)
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
drbd_flush_workqueue(mdev);
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T), CS_ORDERED);
if (retcode < SS_SUCCESS && retcode != SS_NEED_CONNECTION)
/* If we happen to be C_STANDALONE R_SECONDARY, just change to
* D_INCONSISTENT, and set all bits in the bitmap. Otherwise,
* try to start a resync handshake as sync target for full sync.
*/
if (mdev->state.conn == C_STANDALONE && mdev->state.role == R_SECONDARY) {
retcode = drbd_request_state(mdev, NS(disk, D_INCONSISTENT));
if (retcode >= SS_SUCCESS) {
if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write,
"set_n_write from invalidate", BM_LOCKED_MASK))
retcode = ERR_IO_MD_DISK;
}
} else
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T));
while (retcode == SS_NEED_CONNECTION) {
spin_lock_irq(&mdev->tconn->req_lock);
if (mdev->state.conn < C_CONNECTED)
retcode = _drbd_set_state(_NS(mdev, disk, D_INCONSISTENT), CS_VERBOSE, NULL);
spin_unlock_irq(&mdev->tconn->req_lock);
if (retcode != SS_NEED_CONNECTION)
break;
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T));
}
drbd_resume_io(mdev);
out:
@ -2475,21 +2521,22 @@ int drbd_adm_invalidate_peer(struct sk_buff *skb, struct genl_info *info)
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
drbd_flush_workqueue(mdev);
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S), CS_ORDERED);
if (retcode < SS_SUCCESS) {
if (retcode == SS_NEED_CONNECTION && mdev->state.role == R_PRIMARY) {
/* The peer will get a resync upon connect anyways.
* Just make that into a full resync. */
retcode = drbd_request_state(mdev, NS(pdsk, D_INCONSISTENT));
if (retcode >= SS_SUCCESS) {
if (drbd_bitmap_io(mdev, &drbd_bmio_set_susp_al,
"set_n_write from invalidate_peer",
BM_LOCKED_SET_ALLOWED))
retcode = ERR_IO_MD_DISK;
}
} else
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S));
}
/* If we happen to be C_STANDALONE R_PRIMARY, just set all bits
* in the bitmap. Otherwise, try to start a resync handshake
* as sync source for full sync.
*/
if (mdev->state.conn == C_STANDALONE && mdev->state.role == R_PRIMARY) {
/* The peer will get a resync upon connect anyways. Just make that
into a full resync. */
retcode = drbd_request_state(mdev, NS(pdsk, D_INCONSISTENT));
if (retcode >= SS_SUCCESS) {
if (drbd_bitmap_io(mdev, &drbd_bmio_set_susp_al,
"set_n_write from invalidate_peer",
BM_LOCKED_SET_ALLOWED))
retcode = ERR_IO_MD_DISK;
}
} else
retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S));
drbd_resume_io(mdev);
out:
@ -3162,6 +3209,7 @@ static enum drbd_ret_code adm_delete_minor(struct drbd_conf *mdev)
CS_VERBOSE + CS_WAIT_COMPLETE);
idr_remove(&mdev->tconn->volumes, mdev->vnr);
idr_remove(&minors, mdev_to_minor(mdev));
destroy_workqueue(mdev->submit.wq);
del_gendisk(mdev->vdisk);
synchronize_rcu();
kref_put(&mdev->kref, &drbd_minor_destroy);

10
drivers/block/drbd/drbd_proc.c
View file

@ -313,8 +313,14 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
static int drbd_proc_open(struct inode *inode, struct file *file)
{
if (try_module_get(THIS_MODULE))
return single_open(file, drbd_seq_show, PDE_DATA(inode));
int err;
if (try_module_get(THIS_MODULE)) {
err = single_open(file, drbd_seq_show, PDE_DATA(inode));
if (err)
module_put(THIS_MODULE);
return err;
}
return -ENODEV;
}

16
drivers/block/drbd/drbd_receiver.c
View file

@ -850,6 +850,7 @@ int drbd_connected(struct drbd_conf *mdev)
err = drbd_send_current_state(mdev);
clear_bit(USE_DEGR_WFC_T, &mdev->flags);
clear_bit(RESIZE_PENDING, &mdev->flags);
atomic_set(&mdev->ap_in_flight, 0);
mod_timer(&mdev->request_timer, jiffies + HZ); /* just start it here. */
return err;
}
@ -2266,7 +2267,7 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
drbd_set_out_of_sync(mdev, peer_req->i.sector, peer_req->i.size);
peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
drbd_al_begin_io(mdev, &peer_req->i);
drbd_al_begin_io(mdev, &peer_req->i, true);
}
err = drbd_submit_peer_request(mdev, peer_req, rw, DRBD_FAULT_DT_WR);
@ -2662,7 +2663,6 @@ static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
if (hg == -1 && mdev->state.role == R_PRIMARY) {
enum drbd_state_rv rv2;
drbd_set_role(mdev, R_SECONDARY, 0);
/* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
* we might be here in C_WF_REPORT_PARAMS which is transient.
* we do not need to wait for the after state change work either. */
@ -3993,7 +3993,7 @@ static int receive_state(struct drbd_tconn *tconn, struct packet_info *pi)
clear_bit(DISCARD_MY_DATA, &mdev->flags);
drbd_md_sync(mdev); /* update connected indicator, la_size, ... */
drbd_md_sync(mdev); /* update connected indicator, la_size_sect, ... */
return 0;
}
@ -4660,8 +4660,8 @@ static int drbd_do_features(struct drbd_tconn *tconn)
#if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE)
static int drbd_do_auth(struct drbd_tconn *tconn)
{
dev_err(DEV, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
dev_err(DEV, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
conn_err(tconn, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
conn_err(tconn, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
return -1;
}
#else
@ -5258,9 +5258,11 @@ int drbd_asender(struct drbd_thread *thi)
bool ping_timeout_active = false;
struct net_conf *nc;
int ping_timeo, tcp_cork, ping_int;
struct sched_param param = { .sched_priority = 2 };
current->policy = SCHED_RR; /* Make this a realtime task! */
current->rt_priority = 2; /* more important than all other tasks */
rv = sched_setscheduler(current, SCHED_RR, &param);
if (rv < 0)
conn_err(tconn, "drbd_asender: ERROR set priority, ret=%d\n", rv);
while (get_t_state(thi) == RUNNING) {
drbd_thread_current_set_cpu(thi);

192
drivers/block/drbd/drbd_req.c
View file

@ -34,14 +34,14 @@
static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size);
/* Update disk stats at start of I/O request */
static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req, struct bio *bio)
static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req)
{
const int rw = bio_data_dir(bio);
const int rw = bio_data_dir(req->master_bio);
int cpu;
cpu = part_stat_lock();
part_round_stats(cpu, &mdev->vdisk->part0);
part_stat_inc(cpu, &mdev->vdisk->part0, ios[rw]);
part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], bio_sectors(bio));
part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], req->i.size >> 9);
(void) cpu; /* The macro invocations above want the cpu argument, I do not like
the compiler warning about cpu only assigned but never used... */
part_inc_in_flight(&mdev->vdisk->part0, rw);
@ -263,8 +263,7 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m)
else
root = &mdev->read_requests;
drbd_remove_request_interval(root, req);
} else if (!(s & RQ_POSTPONED))
D_ASSERT((s & (RQ_NET_MASK & ~RQ_NET_DONE)) == 0);
}
/* Before we can signal completion to the upper layers,
* we may need to close the current transfer log epoch.
@ -755,6 +754,11 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
D_ASSERT(req->rq_state & RQ_NET_PENDING);
mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK|RQ_NET_DONE);
break;
case QUEUE_AS_DRBD_BARRIER:
start_new_tl_epoch(mdev->tconn);
mod_rq_state(req, m, 0, RQ_NET_OK|RQ_NET_DONE);
break;
};
return rv;
@ -861,8 +865,10 @@ static void maybe_pull_ahead(struct drbd_conf *mdev)
bool congested = false;
enum drbd_on_congestion on_congestion;
rcu_read_lock();
nc = rcu_dereference(tconn->net_conf);
on_congestion = nc ? nc->on_congestion : OC_BLOCK;
rcu_read_unlock();
if (on_congestion == OC_BLOCK ||
tconn->agreed_pro_version < 96)
return;
@ -956,14 +962,8 @@ static int drbd_process_write_request(struct drbd_request *req)
struct drbd_conf *mdev = req->w.mdev;
int remote, send_oos;
rcu_read_lock();
remote = drbd_should_do_remote(mdev->state);
if (remote) {
maybe_pull_ahead(mdev);
remote = drbd_should_do_remote(mdev->state);
}
send_oos = drbd_should_send_out_of_sync(mdev->state);
rcu_read_unlock();
/* Need to replicate writes. Unless it is an empty flush,
* which is better mapped to a DRBD P_BARRIER packet,
@ -975,8 +975,8 @@ static int drbd_process_write_request(struct drbd_request *req)
/* The only size==0 bios we expect are empty flushes. */
D_ASSERT(req->master_bio->bi_rw & REQ_FLUSH);
if (remote)
start_new_tl_epoch(mdev->tconn);
return 0;
_req_mod(req, QUEUE_AS_DRBD_BARRIER);
return remote;
}
if (!remote && !send_oos)
@ -1020,12 +1020,24 @@ drbd_submit_req_private_bio(struct drbd_request *req)
bio_endio(bio, -EIO);
}
void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
static void drbd_queue_write(struct drbd_conf *mdev, struct drbd_request *req)
{
const int rw = bio_rw(bio);
struct bio_and_error m = { NULL, };
spin_lock(&mdev->submit.lock);
list_add_tail(&req->tl_requests, &mdev->submit.writes);
spin_unlock(&mdev->submit.lock);
queue_work(mdev->submit.wq, &mdev->submit.worker);
}
/* returns the new drbd_request pointer, if the caller is expected to
* drbd_send_and_submit() it (to save latency), or NULL if we queued the
* request on the submitter thread.
* Returns ERR_PTR(-ENOMEM) if we cannot allocate a drbd_request.
*/
struct drbd_request *
drbd_request_prepare(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
{
const int rw = bio_data_dir(bio);
struct drbd_request *req;
bool no_remote = false;
/* allocate outside of all locks; */
req = drbd_req_new(mdev, bio);
@ -1035,7 +1047,7 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
* if user cannot handle io errors, that's not our business. */
dev_err(DEV, "could not kmalloc() req\n");
bio_endio(bio, -ENOMEM);
return;
return ERR_PTR(-ENOMEM);
}
req->start_time = start_time;
@ -1044,28 +1056,40 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
req->private_bio = NULL;
}
/* For WRITES going to the local disk, grab a reference on the target
* extent. This waits for any resync activity in the corresponding
* resync extent to finish, and, if necessary, pulls in the target
* extent into the activity log, which involves further disk io because
* of transactional on-disk meta data updates.
* Empty flushes don't need to go into the activity log, they can only
* flush data for pending writes which are already in there. */
/* Update disk stats */
_drbd_start_io_acct(mdev, req);
if (rw == WRITE && req->private_bio && req->i.size
&& !test_bit(AL_SUSPENDED, &mdev->flags)) {
if (!drbd_al_begin_io_fastpath(mdev, &req->i)) {
drbd_queue_write(mdev, req);
return NULL;
}
req->rq_state |= RQ_IN_ACT_LOG;
drbd_al_begin_io(mdev, &req->i);
}
return req;
}
static void drbd_send_and_submit(struct drbd_conf *mdev, struct drbd_request *req)
{
const int rw = bio_rw(req->master_bio);
struct bio_and_error m = { NULL, };
bool no_remote = false;
spin_lock_irq(&mdev->tconn->req_lock);
if (rw == WRITE) {
/* This may temporarily give up the req_lock,
* but will re-aquire it before it returns here.
* Needs to be before the check on drbd_suspended() */
complete_conflicting_writes(req);
/* no more giving up req_lock from now on! */
/* check for congestion, and potentially stop sending
* full data updates, but start sending "dirty bits" only. */
maybe_pull_ahead(mdev);
}
/* no more giving up req_lock from now on! */
if (drbd_suspended(mdev)) {
/* push back and retry: */
@ -1078,9 +1102,6 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
goto out;
}
/* Update disk stats */
_drbd_start_io_acct(mdev, req, bio);
/* We fail READ/READA early, if we can not serve it.
* We must do this before req is registered on any lists.
* Otherwise, drbd_req_complete() will queue failed READ for retry. */
@ -1137,7 +1158,116 @@ out:
if (m.bio)
complete_master_bio(mdev, &m);
return;
}
void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
{
struct drbd_request *req = drbd_request_prepare(mdev, bio, start_time);
if (IS_ERR_OR_NULL(req))
return;
drbd_send_and_submit(mdev, req);
}
static void submit_fast_path(struct drbd_conf *mdev, struct list_head *incoming)
{
struct drbd_request *req, *tmp;
list_for_each_entry_safe(req, tmp, incoming, tl_requests) {
const int rw = bio_data_dir(req->master_bio);
if (rw == WRITE /* rw != WRITE should not even end up here! */
&& req->private_bio && req->i.size
&& !test_bit(AL_SUSPENDED, &mdev->flags)) {
if (!drbd_al_begin_io_fastpath(mdev, &req->i))
continue;
req->rq_state |= RQ_IN_ACT_LOG;
}
list_del_init(&req->tl_requests);
drbd_send_and_submit(mdev, req);
}
}
static bool prepare_al_transaction_nonblock(struct drbd_conf *mdev,
struct list_head *incoming,
struct list_head *pending)
{
struct drbd_request *req, *tmp;
int wake = 0;
int err;
spin_lock_irq(&mdev->al_lock);
list_for_each_entry_safe(req, tmp, incoming, tl_requests) {
err = drbd_al_begin_io_nonblock(mdev, &req->i);
if (err == -EBUSY)
wake = 1;
if (err)
continue;
req->rq_state |= RQ_IN_ACT_LOG;
list_move_tail(&req->tl_requests, pending);
}
spin_unlock_irq(&mdev->al_lock);
if (wake)
wake_up(&mdev->al_wait);
return !list_empty(pending);
}
void do_submit(struct work_struct *ws)
{
struct drbd_conf *mdev = container_of(ws, struct drbd_conf, submit.worker);
LIST_HEAD(incoming);
LIST_HEAD(pending);
struct drbd_request *req, *tmp;
for (;;) {
spin_lock(&mdev->submit.lock);
list_splice_tail_init(&mdev->submit.writes, &incoming);
spin_unlock(&mdev->submit.lock);
submit_fast_path(mdev, &incoming);
if (list_empty(&incoming))
break;
wait_event(mdev->al_wait, prepare_al_transaction_nonblock(mdev, &incoming, &pending));
/* Maybe more was queued, while we prepared the transaction?
* Try to stuff them into this transaction as well.
* Be strictly non-blocking here, no wait_event, we already
* have something to commit.
* Stop if we don't make any more progres.
*/
for (;;) {
LIST_HEAD(more_pending);
LIST_HEAD(more_incoming);
bool made_progress;
/* It is ok to look outside the lock,
* it's only an optimization anyways */
if (list_empty(&mdev->submit.writes))
break;
spin_lock(&mdev->submit.lock);
list_splice_tail_init(&mdev->submit.writes, &more_incoming);
spin_unlock(&mdev->submit.lock);
if (list_empty(&more_incoming))
break;
made_progress = prepare_al_transaction_nonblock(mdev, &more_incoming, &more_pending);
list_splice_tail_init(&more_pending, &pending);
list_splice_tail_init(&more_incoming, &incoming);
if (!made_progress)
break;
}
drbd_al_begin_io_commit(mdev, false);
list_for_each_entry_safe(req, tmp, &pending, tl_requests) {
list_del_init(&req->tl_requests);
drbd_send_and_submit(mdev, req);
}
}
}
void drbd_make_request(struct request_queue *q, struct bio *bio)

8
drivers/block/drbd/drbd_req.h
View file

@ -88,6 +88,14 @@ enum drbd_req_event {
QUEUE_FOR_NET_READ,
QUEUE_FOR_SEND_OOS,
/* An empty flush is queued as P_BARRIER,
* which will cause it to complete "successfully",
* even if the local disk flush failed.
*
* Just like "real" requests, empty flushes (blkdev_issue_flush()) will
* only see an error if neither local nor remote data is reachable. */
QUEUE_AS_DRBD_BARRIER,
SEND_CANCELED,
SEND_FAILED,
HANDED_OVER_TO_NETWORK,

28
drivers/block/drbd/drbd_state.c
View file

@ -570,6 +570,13 @@ is_valid_state(struct drbd_conf *mdev, union drbd_state ns)
mdev->tconn->agreed_pro_version < 88)
rv = SS_NOT_SUPPORTED;
else if (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)
rv = SS_NO_UP_TO_DATE_DISK;
else if ((ns.conn == C_STARTING_SYNC_S || ns.conn == C_STARTING_SYNC_T) &&
ns.pdsk == D_UNKNOWN)
rv = SS_NEED_CONNECTION;
else if (ns.conn >= C_CONNECTED && ns.pdsk == D_UNKNOWN)
rv = SS_CONNECTED_OUTDATES;
@ -635,6 +642,10 @@ is_valid_soft_transition(union drbd_state os, union drbd_state ns, struct drbd_t
&& os.conn < C_WF_REPORT_PARAMS)
rv = SS_NEED_CONNECTION; /* No NetworkFailure -> SyncTarget etc... */
if (ns.conn == C_DISCONNECTING && ns.pdsk == D_OUTDATED &&
os.conn < C_CONNECTED && os.pdsk > D_OUTDATED)
rv = SS_OUTDATE_WO_CONN;
return rv;
}
@ -1377,13 +1388,6 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
&drbd_bmio_set_n_write, &abw_start_sync,
"set_n_write from StartingSync", BM_LOCKED_TEST_ALLOWED);
/* We are invalidating our self... */
if (os.conn < C_CONNECTED && ns.conn < C_CONNECTED &&
os.disk > D_INCONSISTENT && ns.disk == D_INCONSISTENT)
/* other bitmap operation expected during this phase */
drbd_queue_bitmap_io(mdev, &drbd_bmio_set_n_write, NULL,
"set_n_write from invalidate", BM_LOCKED_MASK);
/* first half of local IO error, failure to attach,
* or administrative detach */
if (os.disk != D_FAILED && ns.disk == D_FAILED) {
@ -1748,13 +1752,9 @@ _conn_rq_cond(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state
if (test_and_clear_bit(CONN_WD_ST_CHG_FAIL, &tconn->flags))
return SS_CW_FAILED_BY_PEER;
rv = tconn->cstate != C_WF_REPORT_PARAMS ? SS_CW_NO_NEED : SS_UNKNOWN_ERROR;
if (rv == SS_UNKNOWN_ERROR)
rv = conn_is_valid_transition(tconn, mask, val, 0);
if (rv == SS_SUCCESS)
rv = SS_UNKNOWN_ERROR; /* cont waiting, otherwise fail. */
rv = conn_is_valid_transition(tconn, mask, val, 0);
if (rv == SS_SUCCESS && tconn->cstate == C_WF_REPORT_PARAMS)
rv = SS_UNKNOWN_ERROR; /* continue waiting */
return rv;
}

1
drivers/block/drbd/drbd_strings.c
View file

@ -89,6 +89,7 @@ static const char *drbd_state_sw_errors[] = {
[-SS_LOWER_THAN_OUTDATED] = "Disk state is lower than outdated",
[-SS_IN_TRANSIENT_STATE] = "In transient state, retry after next state change",
[-SS_CONCURRENT_ST_CHG] = "Concurrent state changes detected and aborted",
[-SS_OUTDATE_WO_CONN] = "Need a connection for a graceful disconnect/outdate peer",
[-SS_O_VOL_PEER_PRI] = "Other vol primary on peer not allowed by config",
};

24
drivers/block/drbd/drbd_worker.c
View file

@ -89,7 +89,8 @@ void drbd_md_io_complete(struct bio *bio, int error)
md_io->done = 1;
wake_up(&mdev->misc_wait);
bio_put(bio);
put_ldev(mdev);
if (mdev->ldev) /* special case: drbd_md_read() during drbd_adm_attach() */
put_ldev(mdev);
}
/* reads on behalf of the partner,
@ -1410,7 +1411,7 @@ int w_restart_disk_io(struct drbd_work *w, int cancel)
struct drbd_conf *mdev = w->mdev;
if (bio_data_dir(req->master_bio) == WRITE && req->rq_state & RQ_IN_ACT_LOG)
drbd_al_begin_io(mdev, &req->i);
drbd_al_begin_io(mdev, &req->i, false);
drbd_req_make_private_bio(req, req->master_bio);
req->private_bio->bi_bdev = mdev->ldev->backing_bdev;
@ -1425,7 +1426,7 @@ static int _drbd_may_sync_now(struct drbd_conf *mdev)
int resync_after;
while (1) {
if (!odev->ldev)
if (!odev->ldev || odev->state.disk == D_DISKLESS)
return 1;
rcu_read_lock();
resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after;
@ -1433,7 +1434,7 @@ static int _drbd_may_sync_now(struct drbd_conf *mdev)
if (resync_after == -1)
return 1;
odev = minor_to_mdev(resync_after);
if (!expect(odev))
if (!odev)
return 1;
if ((odev->state.conn >= C_SYNC_SOURCE &&
odev->state.conn <= C_PAUSED_SYNC_T) ||
@ -1515,7 +1516,7 @@ enum drbd_ret_code drbd_resync_after_valid(struct drbd_conf *mdev, int o_minor)
if (o_minor == -1)
return NO_ERROR;
if (o_minor < -1 || minor_to_mdev(o_minor) == NULL)
if (o_minor < -1 || o_minor > MINORMASK)
return ERR_RESYNC_AFTER;
/* check for loops */
@ -1524,6 +1525,15 @@ enum drbd_ret_code drbd_resync_after_valid(struct drbd_conf *mdev, int o_minor)
if (odev == mdev)
return ERR_RESYNC_AFTER_CYCLE;
/* You are free to depend on diskless, non-existing,
* or not yet/no longer existing minors.
* We only reject dependency loops.
* We cannot follow the dependency chain beyond a detached or
* missing minor.
*/
if (!odev || !odev->ldev || odev->state.disk == D_DISKLESS)
return NO_ERROR;
rcu_read_lock();
resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after;
rcu_read_unlock();
@ -1652,7 +1662,9 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
clear_bit(B_RS_H_DONE, &mdev->flags);
write_lock_irq(&global_state_lock);
if (!get_ldev_if_state(mdev, D_NEGOTIATING)) {
/* Did some connection breakage or IO error race with us? */
if (mdev->state.conn < C_CONNECTED
|| !get_ldev_if_state(mdev, D_NEGOTIATING)) {
write_unlock_irq(&global_state_lock);
mutex_unlock(mdev->state_mutex);
return;

2
drivers/block/mg_disk.c
View file

@ -780,6 +780,7 @@ static const struct block_device_operations mg_disk_ops = {
.getgeo = mg_getgeo
};
#ifdef CONFIG_PM_SLEEP
static int mg_suspend(struct device *dev)
{
struct mg_drv_data *prv_data = dev->platform_data;
@ -824,6 +825,7 @@ static int mg_resume(struct device *dev)
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(mg_pm, mg_suspend, mg_resume);

83
drivers/block/mtip32xx/mtip32xx.c
View file

@ -728,7 +728,10 @@ static void mtip_async_complete(struct mtip_port *port,
atomic_set(&port->commands[tag].active, 0);
release_slot(port, tag);
up(&port->cmd_slot);
if (unlikely(command->unaligned))
up(&port->cmd_slot_unal);
else
up(&port->cmd_slot);
}
/*
@ -1560,10 +1563,12 @@ static int mtip_get_identify(struct mtip_port *port, void __user *user_buffer)
}
#endif
#ifdef MTIP_TRIM /* Disabling TRIM support temporarily */
/* Demux ID.DRAT & ID.RZAT to determine trim support */
if (port->identify[69] & (1 << 14) && port->identify[69] & (1 << 5))
port->dd->trim_supp = true;
else
#endif
port->dd->trim_supp = false;
/* Set the identify buffer as valid. */
@ -2557,7 +2562,7 @@ static int mtip_hw_ioctl(struct driver_data *dd, unsigned int cmd,
*/
static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector,
int nsect, int nents, int tag, void *callback,
void *data, int dir)
void *data, int dir, int unaligned)
{
struct host_to_dev_fis *fis;
struct mtip_port *port = dd->port;
@ -2570,6 +2575,7 @@ static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector,
command->scatter_ents = nents;
command->unaligned = unaligned;
/*
* The number of retries for this command before it is
* reported as a failure to the upper layers.
@ -2598,6 +2604,9 @@ static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector,
fis->res3 = 0;
fill_command_sg(dd, command, nents);
if (unaligned)
fis->device |= 1 << 7;
/* Populate the command header */
command->command_header->opts =
__force_bit2int cpu_to_le32(
@ -2644,9 +2653,13 @@ static void mtip_hw_submit_io(struct driver_data *dd, sector_t sector,
* return value
* None
*/
static void mtip_hw_release_scatterlist(struct driver_data *dd, int tag)
static void mtip_hw_release_scatterlist(struct driver_data *dd, int tag,
int unaligned)
{
struct semaphore *sem = unaligned ? &dd->port->cmd_slot_unal :
&dd->port->cmd_slot;
release_slot(dd->port, tag);
up(sem);
}
/*
@ -2661,22 +2674,25 @@ static void mtip_hw_release_scatterlist(struct driver_data *dd, int tag)
* or NULL if no command slots are available.
*/
static struct scatterlist *mtip_hw_get_scatterlist(struct driver_data *dd,
int *tag)
int *tag, int unaligned)
{
struct semaphore *sem = unaligned ? &dd->port->cmd_slot_unal :
&dd->port->cmd_slot;
/*
* It is possible that, even with this semaphore, a thread
* may think that no command slots are available. Therefore, we
* need to make an attempt to get_slot().
*/
down(&dd->port->cmd_slot);
down(sem);
*tag = get_slot(dd->port);
if (unlikely(test_bit(MTIP_DDF_REMOVE_PENDING_BIT, &dd->dd_flag))) {
up(&dd->port->cmd_slot);
up(sem);
return NULL;
}
if (unlikely(*tag < 0)) {
up(&dd->port->cmd_slot);
up(sem);
return NULL;
}
@ -3010,6 +3026,11 @@ static inline void hba_setup(struct driver_data *dd)
dd->mmio + HOST_HSORG);
}
static int mtip_device_unaligned_constrained(struct driver_data *dd)
{
return (dd->pdev->device == P420M_DEVICE_ID ? 1 : 0);
}
/*
* Detect the details of the product, and store anything needed
* into the driver data structure. This includes product type and
@ -3232,8 +3253,15 @@ static int mtip_hw_init(struct driver_data *dd)
for (i = 0; i < MTIP_MAX_SLOT_GROUPS; i++)
dd->work[i].port = dd->port;
/* Enable unaligned IO constraints for some devices */
if (mtip_device_unaligned_constrained(dd))
dd->unal_qdepth = MTIP_MAX_UNALIGNED_SLOTS;
else
dd->unal_qdepth = 0;
/* Counting semaphore to track command slot usage */
sema_init(&dd->port->cmd_slot, num_command_slots - 1);
sema_init(&dd->port->cmd_slot, num_command_slots - 1 - dd->unal_qdepth);
sema_init(&dd->port->cmd_slot_unal, dd->unal_qdepth);
/* Spinlock to prevent concurrent issue */
for (i = 0; i < MTIP_MAX_SLOT_GROUPS; i++)
@ -3836,7 +3864,7 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio)
struct scatterlist *sg;
struct bio_vec *bvec;
int nents = 0;
int tag = 0;
int tag = 0, unaligned = 0;
if (unlikely(dd->dd_flag & MTIP_DDF_STOP_IO)) {
if (unlikely(test_bit(MTIP_DDF_REMOVE_PENDING_BIT,
@ -3872,7 +3900,15 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio)
return;
}
sg = mtip_hw_get_scatterlist(dd, &tag);
if (bio_data_dir(bio) == WRITE && bio_sectors(bio) <= 64 &&
dd->unal_qdepth) {
if (bio->bi_sector % 8 != 0) /* Unaligned on 4k boundaries */
unaligned = 1;
else if (bio_sectors(bio) % 8 != 0) /* Aligned but not 4k/8k */
unaligned = 1;
}
sg = mtip_hw_get_scatterlist(dd, &tag, unaligned);
if (likely(sg != NULL)) {
blk_queue_bounce(queue, &bio);
@ -3880,7 +3916,7 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio)
dev_warn(&dd->pdev->dev,
"Maximum number of SGL entries exceeded\n");
bio_io_error(bio);
mtip_hw_release_scatterlist(dd, tag);
mtip_hw_release_scatterlist(dd, tag, unaligned);
return;
}
@ -3900,7 +3936,8 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio)
tag,
bio_endio,
bio,
bio_data_dir(bio));
bio_data_dir(bio),
unaligned);
} else
bio_io_error(bio);
}
@ -4156,26 +4193,24 @@ static int mtip_block_remove(struct driver_data *dd)
*/
static int mtip_block_shutdown(struct driver_data *dd)
{
dev_info(&dd->pdev->dev,
"Shutting down %s ...\n", dd->disk->disk_name);
/* Delete our gendisk structure, and cleanup the blk queue. */
if (dd->disk) {
if (dd->disk->queue)
del_gendisk(dd->disk);
else
put_disk(dd->disk);
}
dev_info(&dd->pdev->dev,
"Shutting down %s ...\n", dd->disk->disk_name);
if (dd->disk->queue) {
del_gendisk(dd->disk);
blk_cleanup_queue(dd->queue);
} else
put_disk(dd->disk);
dd->disk = NULL;
dd->queue = NULL;
}
spin_lock(&rssd_index_lock);
ida_remove(&rssd_index_ida, dd->index);
spin_unlock(&rssd_index_lock);
blk_cleanup_queue(dd->queue);
dd->disk = NULL;
dd->queue = NULL;
mtip_hw_shutdown(dd);
return 0;
}

11
drivers/block/mtip32xx/mtip32xx.h
View file

@ -52,6 +52,9 @@
#define MTIP_FTL_REBUILD_MAGIC 0xED51
#define MTIP_FTL_REBUILD_TIMEOUT_MS 2400000
/* unaligned IO handling */
#define MTIP_MAX_UNALIGNED_SLOTS 8
/* Macro to extract the tag bit number from a tag value. */
#define MTIP_TAG_BIT(tag) (tag & 0x1F)
@ -333,6 +336,8 @@ struct mtip_cmd {
int scatter_ents; /* Number of scatter list entries used */
int unaligned; /* command is unaligned on 4k boundary */
struct scatterlist sg[MTIP_MAX_SG]; /* Scatter list entries */
int retries; /* The number of retries left for this command. */
@ -452,6 +457,10 @@ struct mtip_port {
* command slots available.
*/
struct semaphore cmd_slot;
/* Semaphore to control queue depth of unaligned IOs */
struct semaphore cmd_slot_unal;
/* Spinlock for working around command-issue bug. */
spinlock_t cmd_issue_lock[MTIP_MAX_SLOT_GROUPS];
};
@ -502,6 +511,8 @@ struct driver_data {
int isr_binding;
int unal_qdepth; /* qdepth of unaligned IO queue */
struct list_head online_list; /* linkage for online list */
struct list_head remove_list; /* linkage for removing list */

2
drivers/md/Kconfig
View file

@ -174,6 +174,8 @@ config MD_FAULTY
In unsure, say N.
source "drivers/md/bcache/Kconfig"
config BLK_DEV_DM
tristate "Device mapper support"
---help---

1
drivers/md/Makefile
View file

@ -29,6 +29,7 @@ obj-$(CONFIG_MD_RAID10) += raid10.o
obj-$(CONFIG_MD_RAID456) += raid456.o
obj-$(CONFIG_MD_MULTIPATH) += multipath.o
obj-$(CONFIG_MD_FAULTY) += faulty.o
obj-$(CONFIG_BCACHE) += bcache/
obj-$(CONFIG_BLK_DEV_MD) += md-mod.o
obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
obj-$(CONFIG_DM_BUFIO) += dm-bufio.o

42
drivers/md/bcache/Kconfig Normal file
View file

@ -0,0 +1,42 @@
config BCACHE
tristate "Block device as cache"
select CLOSURES
---help---
Allows a block device to be used as cache for other devices; uses
a btree for indexing and the layout is optimized for SSDs.
See Documentation/bcache.txt for details.
config BCACHE_DEBUG
bool "Bcache debugging"
depends on BCACHE
---help---
Don't select this option unless you're a developer
Enables extra debugging tools (primarily a fuzz tester)
config BCACHE_EDEBUG
bool "Extended runtime checks"
depends on BCACHE
---help---
Don't select this option unless you're a developer
Enables extra runtime checks which significantly affect performance
config BCACHE_CLOSURES_DEBUG
bool "Debug closures"
depends on BCACHE
select DEBUG_FS
---help---
Keeps all active closures in a linked list and provides a debugfs
interface to list them, which makes it possible to see asynchronous
operations that get stuck.
# cgroup code needs to be updated:
#
#config CGROUP_BCACHE
# bool "Cgroup controls for bcache"
# depends on BCACHE && BLK_CGROUP
# ---help---
# TODO

7
drivers/md/bcache/Makefile Normal file
View file

@ -0,0 +1,7 @@
obj-$(CONFIG_BCACHE) += bcache.o
bcache-y := alloc.o btree.o bset.o io.o journal.o writeback.o\
movinggc.o request.o super.o sysfs.o debug.o util.o trace.o stats.o closure.o
CFLAGS_request.o += -Iblock

599
drivers/md/bcache/alloc.c Normal file
View file

@ -0,0 +1,599 @@
/*
* Primary bucket allocation code
*
* Copyright 2012 Google, Inc.
*
* Allocation in bcache is done in terms of buckets:
*
* Each bucket has associated an 8 bit gen; this gen corresponds to the gen in
* btree pointers - they must match for the pointer to be considered valid.
*
* Thus (assuming a bucket has no dirty data or metadata in it) we can reuse a
* bucket simply by incrementing its gen.
*
* The gens (along with the priorities; it's really the gens are important but
* the code is named as if it's the priorities) are written in an arbitrary list
* of buckets on disk, with a pointer to them in the journal header.
*
* When we invalidate a bucket, we have to write its new gen to disk and wait
* for that write to complete before we use it - otherwise after a crash we
* could have pointers that appeared to be good but pointed to data that had
* been overwritten.
*
* Since the gens and priorities are all stored contiguously on disk, we can
* batch this up: We fill up the free_inc list with freshly invalidated buckets,
* call prio_write(), and when prio_write() finishes we pull buckets off the
* free_inc list and optionally discard them.
*
* free_inc isn't the only freelist - if it was, we'd often to sleep while
* priorities and gens were being written before we could allocate. c->free is a
* smaller freelist, and buckets on that list are always ready to be used.
*
* If we've got discards enabled, that happens when a bucket moves from the
* free_inc list to the free list.
*
* There is another freelist, because sometimes we have buckets that we know
* have nothing pointing into them - these we can reuse without waiting for
* priorities to be rewritten. These come from freed btree nodes and buckets
* that garbage collection discovered no longer had valid keys pointing into
* them (because they were overwritten). That's the unused list - buckets on the
* unused list move to the free list, optionally being discarded in the process.
*
* It's also important to ensure that gens don't wrap around - with respect to
* either the oldest gen in the btree or the gen on disk. This is quite
* difficult to do in practice, but we explicitly guard against it anyways - if
* a bucket is in danger of wrapping around we simply skip invalidating it that
* time around, and we garbage collect or rewrite the priorities sooner than we
* would have otherwise.
*
* bch_bucket_alloc() allocates a single bucket from a specific cache.
*
* bch_bucket_alloc_set() allocates one or more buckets from different caches
* out of a cache set.
*
* free_some_buckets() drives all the processes described above. It's called
* from bch_bucket_alloc() and a few other places that need to make sure free
* buckets are ready.
*
* invalidate_buckets_(lru|fifo)() find buckets that are available to be
* invalidated, and then invalidate them and stick them on the free_inc list -
* in either lru or fifo order.
*/
#include "bcache.h"
#include "btree.h"
#include <linux/random.h>
#define MAX_IN_FLIGHT_DISCARDS 8U
/* Bucket heap / gen */
uint8_t bch_inc_gen(struct cache *ca, struct bucket *b)
{
uint8_t ret = ++b->gen;
ca->set->need_gc = max(ca->set->need_gc, bucket_gc_gen(b));
WARN_ON_ONCE(ca->set->need_gc > BUCKET_GC_GEN_MAX);
if (CACHE_SYNC(&ca->set->sb)) {
ca->need_save_prio = max(ca->need_save_prio,
bucket_disk_gen(b));
WARN_ON_ONCE(ca->need_save_prio > BUCKET_DISK_GEN_MAX);
}
return ret;
}
void bch_rescale_priorities(struct cache_set *c, int sectors)
{
struct cache *ca;
struct bucket *b;
unsigned next = c->nbuckets * c->sb.bucket_size / 1024;
unsigned i;
int r;
atomic_sub(sectors, &c->rescale);
do {
r = atomic_read(&c->rescale);
if (r >= 0)
return;
} while (atomic_cmpxchg(&c->rescale, r, r + next) != r);
mutex_lock(&c->bucket_lock);
c->min_prio = USHRT_MAX;
for_each_cache(ca, c, i)
for_each_bucket(b, ca)
if (b->prio &&
b->prio != BTREE_PRIO &&
!atomic_read(&b->pin)) {
b->prio--;
c->min_prio = min(c->min_prio, b->prio);
}
mutex_unlock(&c->bucket_lock);
}
/* Discard/TRIM */
struct discard {
struct list_head list;
struct work_struct work;
struct cache *ca;
long bucket;
struct bio bio;
struct bio_vec bv;
};
static void discard_finish(struct work_struct *w)
{
struct discard *d = container_of(w, struct discard, work);
struct cache *ca = d->ca;
char buf[BDEVNAME_SIZE];
if (!test_bit(BIO_UPTODATE, &d->bio.bi_flags)) {
pr_notice("discard error on %s, disabling",
bdevname(ca->bdev, buf));
d->ca->discard = 0;
}
mutex_lock(&ca->set->bucket_lock);
fifo_push(&ca->free, d->bucket);
list_add(&d->list, &ca->discards);
atomic_dec(&ca->discards_in_flight);
mutex_unlock(&ca->set->bucket_lock);
closure_wake_up(&ca->set->bucket_wait);
wake_up(&ca->set->alloc_wait);
closure_put(&ca->set->cl);
}
static void discard_endio(struct bio *bio, int error)
{
struct discard *d = container_of(bio, struct discard, bio);
schedule_work(&d->work);
}
static void do_discard(struct cache *ca, long bucket)
{
struct discard *d = list_first_entry(&ca->discards,
struct discard, list);
list_del(&d->list);
d->bucket = bucket;
atomic_inc(&ca->discards_in_flight);
closure_get(&ca->set->cl);
bio_init(&d->bio);
d->bio.bi_sector = bucket_to_sector(ca->set, d->bucket);
d->bio.bi_bdev = ca->bdev;
d->bio.bi_rw = REQ_WRITE|REQ_DISCARD;
d->bio.bi_max_vecs = 1;
d->bio.bi_io_vec = d->bio.bi_inline_vecs;
d->bio.bi_size = bucket_bytes(ca);
d->bio.bi_end_io = discard_endio;
bio_set_prio(&d->bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
submit_bio(0, &d->bio);
}
/* Allocation */
static inline bool can_inc_bucket_gen(struct bucket *b)
{
return bucket_gc_gen(b) < BUCKET_GC_GEN_MAX &&
bucket_disk_gen(b) < BUCKET_DISK_GEN_MAX;
}
bool bch_bucket_add_unused(struct cache *ca, struct bucket *b)
{
BUG_ON(GC_MARK(b) || GC_SECTORS_USED(b));
if (fifo_used(&ca->free) > ca->watermark[WATERMARK_MOVINGGC] &&
CACHE_REPLACEMENT(&ca->sb) == CACHE_REPLACEMENT_FIFO)
return false;
b->prio = 0;
if (can_inc_bucket_gen(b) &&
fifo_push(&ca->unused, b - ca->buckets)) {
atomic_inc(&b->pin);
return true;
}
return false;
}
static bool can_invalidate_bucket(struct cache *ca, struct bucket *b)
{
return GC_MARK(b) == GC_MARK_RECLAIMABLE &&
!atomic_read(&b->pin) &&
can_inc_bucket_gen(b);
}
static void invalidate_one_bucket(struct cache *ca, struct bucket *b)
{
bch_inc_gen(ca, b);
b->prio = INITIAL_PRIO;
atomic_inc(&b->pin);
fifo_push(&ca->free_inc, b - ca->buckets);
}
#define bucket_prio(b) \
(((unsigned) (b->prio - ca->set->min_prio)) * GC_SECTORS_USED(b))
#define bucket_max_cmp(l, r) (bucket_prio(l) < bucket_prio(r))
#define bucket_min_cmp(l, r) (bucket_prio(l) > bucket_prio(r))
static void invalidate_buckets_lru(struct cache *ca)
{
struct bucket *b;
ssize_t i;
ca->heap.used = 0;
for_each_bucket(b, ca) {
/*
* If we fill up the unused list, if we then return before
* adding anything to the free_inc list we'll skip writing
* prios/gens and just go back to allocating from the unused
* list:
*/
if (fifo_full(&ca->unused))
return;
if (!can_invalidate_bucket(ca, b))
continue;
if (!GC_SECTORS_USED(b) &&
bch_bucket_add_unused(ca, b))
continue;
if (!heap_full(&ca->heap))
heap_add(&ca->heap, b, bucket_max_cmp);
else if (bucket_max_cmp(b, heap_peek(&ca->heap))) {
ca->heap.data[0] = b;
heap_sift(&ca->heap, 0, bucket_max_cmp);
}
}
for (i = ca->heap.used / 2 - 1; i >= 0; --i)
heap_sift(&ca->heap, i, bucket_min_cmp);
while (!fifo_full(&ca->free_inc)) {
if (!heap_pop(&ca->heap, b, bucket_min_cmp)) {
/*
* We don't want to be calling invalidate_buckets()
* multiple times when it can't do anything
*/
ca->invalidate_needs_gc = 1;
bch_queue_gc(ca->set);
return;
}
invalidate_one_bucket(ca, b);
}
}
static void invalidate_buckets_fifo(struct cache *ca)
{
struct bucket *b;
size_t checked = 0;
while (!fifo_full(&ca->free_inc)) {
if (ca->fifo_last_bucket < ca->sb.first_bucket ||
ca->fifo_last_bucket >= ca->sb.nbuckets)
ca->fifo_last_bucket = ca->sb.first_bucket;
b = ca->buckets + ca->fifo_last_bucket++;
if (can_invalidate_bucket(ca, b))
invalidate_one_bucket(ca, b);
if (++checked >= ca->sb.nbuckets) {
ca->invalidate_needs_gc = 1;
bch_queue_gc(ca->set);
return;
}
}
}
static void invalidate_buckets_random(struct cache *ca)
{
struct bucket *b;
size_t checked = 0;
while (!fifo_full(&ca->free_inc)) {
size_t n;
get_random_bytes(&n, sizeof(n));
n %= (size_t) (ca->sb.nbuckets - ca->sb.first_bucket);
n += ca->sb.first_bucket;
b = ca->buckets + n;
if (can_invalidate_bucket(ca, b))
invalidate_one_bucket(ca, b);
if (++checked >= ca->sb.nbuckets / 2) {
ca->invalidate_needs_gc = 1;
bch_queue_gc(ca->set);
return;
}
}
}
static void invalidate_buckets(struct cache *ca)
{
if (ca->invalidate_needs_gc)
return;
switch (CACHE_REPLACEMENT(&ca->sb)) {
case CACHE_REPLACEMENT_LRU:
invalidate_buckets_lru(ca);
break;
case CACHE_REPLACEMENT_FIFO:
invalidate_buckets_fifo(ca);
break;
case CACHE_REPLACEMENT_RANDOM:
invalidate_buckets_random(ca);
break;
}
pr_debug("free %zu/%zu free_inc %zu/%zu unused %zu/%zu",
fifo_used(&ca->free), ca->free.size,
fifo_used(&ca->free_inc), ca->free_inc.size,
fifo_used(&ca->unused), ca->unused.size);
}
#define allocator_wait(ca, cond) \
do { \
DEFINE_WAIT(__wait); \
\
while (1) { \
prepare_to_wait(&ca->set->alloc_wait, \
&__wait, TASK_INTERRUPTIBLE); \
if (cond) \
break; \
\
mutex_unlock(&(ca)->set->bucket_lock); \
if (test_bit(CACHE_SET_STOPPING_2, &ca->set->flags)) { \
finish_wait(&ca->set->alloc_wait, &__wait); \
closure_return(cl); \
} \
\
schedule(); \
mutex_lock(&(ca)->set->bucket_lock); \
} \
\
finish_wait(&ca->set->alloc_wait, &__wait); \
} while (0)
void bch_allocator_thread(struct closure *cl)
{
struct cache *ca = container_of(cl, struct cache, alloc);
mutex_lock(&ca->set->bucket_lock);
while (1) {
/*
* First, we pull buckets off of the unused and free_inc lists,
* possibly issue discards to them, then we add the bucket to
* the free list:
*/
while (1) {
long bucket;
if ((!atomic_read(&ca->set->prio_blocked) ||
!CACHE_SYNC(&ca->set->sb)) &&
!fifo_empty(&ca->unused))
fifo_pop(&ca->unused, bucket);
else if (!fifo_empty(&ca->free_inc))
fifo_pop(&ca->free_inc, bucket);
else
break;
allocator_wait(ca, (int) fifo_free(&ca->free) >
atomic_read(&ca->discards_in_flight));
if (ca->discard) {
allocator_wait(ca, !list_empty(&ca->discards));
do_discard(ca, bucket);
} else {
fifo_push(&ca->free, bucket);
closure_wake_up(&ca->set->bucket_wait);
}
}
/*
* We've run out of free buckets, we need to find some buckets
* we can invalidate. First, invalidate them in memory and add
* them to the free_inc list:
*/
allocator_wait(ca, ca->set->gc_mark_valid &&
(ca->need_save_prio > 64 ||
!ca->invalidate_needs_gc));
invalidate_buckets(ca);
/*
* Now, we write their new gens to disk so we can start writing
* new stuff to them:
*/
allocator_wait(ca, !atomic_read(&ca->set->prio_blocked));
if (CACHE_SYNC(&ca->set->sb) &&
(!fifo_empty(&ca->free_inc) ||
ca->need_save_prio > 64))
bch_prio_write(ca);
}
}
long bch_bucket_alloc(struct cache *ca, unsigned watermark, struct closure *cl)
{
long r = -1;
again:
wake_up(&ca->set->alloc_wait);
if (fifo_used(&ca->free) > ca->watermark[watermark] &&
fifo_pop(&ca->free, r)) {
struct bucket *b = ca->buckets + r;
#ifdef CONFIG_BCACHE_EDEBUG
size_t iter;
long i;
for (iter = 0; iter < prio_buckets(ca) * 2; iter++)
BUG_ON(ca->prio_buckets[iter] == (uint64_t) r);
fifo_for_each(i, &ca->free, iter)
BUG_ON(i == r);
fifo_for_each(i, &ca->free_inc, iter)
BUG_ON(i == r);
fifo_for_each(i, &ca->unused, iter)
BUG_ON(i == r);
#endif
BUG_ON(atomic_read(&b->pin) != 1);
SET_GC_SECTORS_USED(b, ca->sb.bucket_size);
if (watermark <= WATERMARK_METADATA) {
SET_GC_MARK(b, GC_MARK_METADATA);
b->prio = BTREE_PRIO;
} else {
SET_GC_MARK(b, GC_MARK_RECLAIMABLE);
b->prio = INITIAL_PRIO;
}
return r;
}
pr_debug("alloc failure: blocked %i free %zu free_inc %zu unused %zu",
atomic_read(&ca->set->prio_blocked), fifo_used(&ca->free),
fifo_used(&ca->free_inc), fifo_used(&ca->unused));
if (cl) {
closure_wait(&ca->set->bucket_wait, cl);
if (closure_blocking(cl)) {
mutex_unlock(&ca->set->bucket_lock);
closure_sync(cl);
mutex_lock(&ca->set->bucket_lock);
goto again;
}
}
return -1;
}
void bch_bucket_free(struct cache_set *c, struct bkey *k)
{
unsigned i;
for (i = 0; i < KEY_PTRS(k); i++) {
struct bucket *b = PTR_BUCKET(c, k, i);
SET_GC_MARK(b, GC_MARK_RECLAIMABLE);
SET_GC_SECTORS_USED(b, 0);
bch_bucket_add_unused(PTR_CACHE(c, k, i), b);
}
}
int __bch_bucket_alloc_set(struct cache_set *c, unsigned watermark,
struct bkey *k, int n, struct closure *cl)
{
int i;
lockdep_assert_held(&c->bucket_lock);
BUG_ON(!n || n > c->caches_loaded || n > 8);
bkey_init(k);
/* sort by free space/prio of oldest data in caches */
for (i = 0; i < n; i++) {
struct cache *ca = c->cache_by_alloc[i];
long b = bch_bucket_alloc(ca, watermark, cl);
if (b == -1)
goto err;
k->ptr[i] = PTR(ca->buckets[b].gen,
bucket_to_sector(c, b),
ca->sb.nr_this_dev);
SET_KEY_PTRS(k, i + 1);
}
return 0;
err:
bch_bucket_free(c, k);
__bkey_put(c, k);
return -1;
}
int bch_bucket_alloc_set(struct cache_set *c, unsigned watermark,
struct bkey *k, int n, struct closure *cl)
{
int ret;
mutex_lock(&c->bucket_lock);
ret = __bch_bucket_alloc_set(c, watermark, k, n, cl);
mutex_unlock(&c->bucket_lock);
return ret;
}
/* Init */
void bch_cache_allocator_exit(struct cache *ca)
{
struct discard *d;
while (!list_empty(&ca->discards)) {
d = list_first_entry(&ca->discards, struct discard, list);
cancel_work_sync(&d->work);
list_del(&d->list);
kfree(d);
}
}
int bch_cache_allocator_init(struct cache *ca)
{
unsigned i;
/*
* Reserve:
* Prio/gen writes first
* Then 8 for btree allocations
* Then half for the moving garbage collector
*/
ca->watermark[WATERMARK_PRIO] = 0;
ca->watermark[WATERMARK_METADATA] = prio_buckets(ca);
ca->watermark[WATERMARK_MOVINGGC] = 8 +
ca->watermark[WATERMARK_METADATA];
ca->watermark[WATERMARK_NONE] = ca->free.size / 2 +
ca->watermark[WATERMARK_MOVINGGC];
for (i = 0; i < MAX_IN_FLIGHT_DISCARDS; i++) {
struct discard *d = kzalloc(sizeof(*d), GFP_KERNEL);
if (!d)
return -ENOMEM;
d->ca = ca;
INIT_WORK(&d->work, discard_finish);
list_add(&d->list, &ca->discards);
}
return 0;
}

1259
drivers/md/bcache/bcache.h Normal file
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1192
drivers/md/bcache/bset.c Normal file
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379
drivers/md/bcache/bset.h Normal file
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@ -0,0 +1,379 @@
#ifndef _BCACHE_BSET_H
#define _BCACHE_BSET_H
/*
* BKEYS:
*
* A bkey contains a key, a size field, a variable number of pointers, and some
* ancillary flag bits.
*
* We use two different functions for validating bkeys, bch_ptr_invalid and
* bch_ptr_bad().
*
* bch_ptr_invalid() primarily filters out keys and pointers that would be
* invalid due to some sort of bug, whereas bch_ptr_bad() filters out keys and
* pointer that occur in normal practice but don't point to real data.
*
* The one exception to the rule that ptr_invalid() filters out invalid keys is
* that it also filters out keys of size 0 - these are keys that have been
* completely overwritten. It'd be safe to delete these in memory while leaving
* them on disk, just unnecessary work - so we filter them out when resorting
* instead.
*
* We can't filter out stale keys when we're resorting, because garbage
* collection needs to find them to ensure bucket gens don't wrap around -
* unless we're rewriting the btree node those stale keys still exist on disk.
*
* We also implement functions here for removing some number of sectors from the
* front or the back of a bkey - this is mainly used for fixing overlapping
* extents, by removing the overlapping sectors from the older key.
*
* BSETS:
*
* A bset is an array of bkeys laid out contiguously in memory in sorted order,
* along with a header. A btree node is made up of a number of these, written at
* different times.
*
* There could be many of them on disk, but we never allow there to be more than
* 4 in memory - we lazily resort as needed.
*
* We implement code here for creating and maintaining auxiliary search trees
* (described below) for searching an individial bset, and on top of that we
* implement a btree iterator.
*
* BTREE ITERATOR:
*
* Most of the code in bcache doesn't care about an individual bset - it needs
* to search entire btree nodes and iterate over them in sorted order.
*
* The btree iterator code serves both functions; it iterates through the keys
* in a btree node in sorted order, starting from either keys after a specific
* point (if you pass it a search key) or the start of the btree node.
*
* AUXILIARY SEARCH TREES:
*
* Since keys are variable length, we can't use a binary search on a bset - we
* wouldn't be able to find the start of the next key. But binary searches are
* slow anyways, due to terrible cache behaviour; bcache originally used binary
* searches and that code topped out at under 50k lookups/second.
*
* So we need to construct some sort of lookup table. Since we only insert keys
* into the last (unwritten) set, most of the keys within a given btree node are
* usually in sets that are mostly constant. We use two different types of
* lookup tables to take advantage of this.
*
* Both lookup tables share in common that they don't index every key in the
* set; they index one key every BSET_CACHELINE bytes, and then a linear search
* is used for the rest.
*
* For sets that have been written to disk and are no longer being inserted
* into, we construct a binary search tree in an array - traversing a binary
* search tree in an array gives excellent locality of reference and is very
* fast, since both children of any node are adjacent to each other in memory
* (and their grandchildren, and great grandchildren...) - this means
* prefetching can be used to great effect.
*
* It's quite useful performance wise to keep these nodes small - not just
* because they're more likely to be in L2, but also because we can prefetch
* more nodes on a single cacheline and thus prefetch more iterations in advance
* when traversing this tree.
*
* Nodes in the auxiliary search tree must contain both a key to compare against
* (we don't want to fetch the key from the set, that would defeat the purpose),
* and a pointer to the key. We use a few tricks to compress both of these.
*
* To compress the pointer, we take advantage of the fact that one node in the
* search tree corresponds to precisely BSET_CACHELINE bytes in the set. We have
* a function (to_inorder()) that takes the index of a node in a binary tree and
* returns what its index would be in an inorder traversal, so we only have to
* store the low bits of the offset.
*
* The key is 84 bits (KEY_DEV + key->key, the offset on the device). To
* compress that, we take advantage of the fact that when we're traversing the
* search tree at every iteration we know that both our search key and the key
* we're looking for lie within some range - bounded by our previous
* comparisons. (We special case the start of a search so that this is true even
* at the root of the tree).
*
* So we know the key we're looking for is between a and b, and a and b don't
* differ higher than bit 50, we don't need to check anything higher than bit
* 50.
*
* We don't usually need the rest of the bits, either; we only need enough bits
* to partition the key range we're currently checking. Consider key n - the
* key our auxiliary search tree node corresponds to, and key p, the key
* immediately preceding n. The lowest bit we need to store in the auxiliary
* search tree is the highest bit that differs between n and p.
*
* Note that this could be bit 0 - we might sometimes need all 80 bits to do the
* comparison. But we'd really like our nodes in the auxiliary search tree to be
* of fixed size.
*
* The solution is to make them fixed size, and when we're constructing a node
* check if p and n differed in the bits we needed them to. If they don't we
* flag that node, and when doing lookups we fallback to comparing against the
* real key. As long as this doesn't happen to often (and it seems to reliably
* happen a bit less than 1% of the time), we win - even on failures, that key
* is then more likely to be in cache than if we were doing binary searches all
* the way, since we're touching so much less memory.
*
* The keys in the auxiliary search tree are stored in (software) floating
* point, with an exponent and a mantissa. The exponent needs to be big enough
* to address all the bits in the original key, but the number of bits in the
* mantissa is somewhat arbitrary; more bits just gets us fewer failures.
*
* We need 7 bits for the exponent and 3 bits for the key's offset (since keys
* are 8 byte aligned); using 22 bits for the mantissa means a node is 4 bytes.
* We need one node per 128 bytes in the btree node, which means the auxiliary
* search trees take up 3% as much memory as the btree itself.
*
* Constructing these auxiliary search trees is moderately expensive, and we
* don't want to be constantly rebuilding the search tree for the last set
* whenever we insert another key into it. For the unwritten set, we use a much
* simpler lookup table - it's just a flat array, so index i in the lookup table
* corresponds to the i range of BSET_CACHELINE bytes in the set. Indexing
* within each byte range works the same as with the auxiliary search trees.
*
* These are much easier to keep up to date when we insert a key - we do it
* somewhat lazily; when we shift a key up we usually just increment the pointer
* to it, only when it would overflow do we go to the trouble of finding the
* first key in that range of bytes again.
*/
/* Btree key comparison/iteration */
struct btree_iter {
size_t size, used;
struct btree_iter_set {
struct bkey *k, *end;
} data[MAX_BSETS];
};
struct bset_tree {
/*
* We construct a binary tree in an array as if the array
* started at 1, so that things line up on the same cachelines
* better: see comments in bset.c at cacheline_to_bkey() for
* details
*/
/* size of the binary tree and prev array */
unsigned size;
/* function of size - precalculated for to_inorder() */
unsigned extra;
/* copy of the last key in the set */
struct bkey end;
struct bkey_float *tree;
/*
* The nodes in the bset tree point to specific keys - this
* array holds the sizes of the previous key.
*
* Conceptually it's a member of struct bkey_float, but we want
* to keep bkey_float to 4 bytes and prev isn't used in the fast
* path.
*/
uint8_t *prev;
/* The actual btree node, with pointers to each sorted set */
struct bset *data;
};
static __always_inline int64_t bkey_cmp(const struct bkey *l,
const struct bkey *r)
{
return unlikely(KEY_INODE(l) != KEY_INODE(r))
? (int64_t) KEY_INODE(l) - (int64_t) KEY_INODE(r)
: (int64_t) KEY_OFFSET(l) - (int64_t) KEY_OFFSET(r);
}
static inline size_t bkey_u64s(const struct bkey *k)
{
BUG_ON(KEY_CSUM(k) > 1);
return 2 + KEY_PTRS(k) + (KEY_CSUM(k) ? 1 : 0);
}
static inline size_t bkey_bytes(const struct bkey *k)
{
return bkey_u64s(k) * sizeof(uint64_t);
}
static inline void bkey_copy(struct bkey *dest, const struct bkey *src)
{
memcpy(dest, src, bkey_bytes(src));
}
static inline void bkey_copy_key(struct bkey *dest, const struct bkey *src)
{
if (!src)
src = &KEY(0, 0, 0);
SET_KEY_INODE(dest, KEY_INODE(src));
SET_KEY_OFFSET(dest, KEY_OFFSET(src));
}
static inline struct bkey *bkey_next(const struct bkey *k)
{
uint64_t *d = (void *) k;
return (struct bkey *) (d + bkey_u64s(k));
}
/* Keylists */
struct keylist {
struct bkey *top;
union {
uint64_t *list;
struct bkey *bottom;
};
/* Enough room for btree_split's keys without realloc */
#define KEYLIST_INLINE 16
uint64_t d[KEYLIST_INLINE];
};
static inline void bch_keylist_init(struct keylist *l)
{
l->top = (void *) (l->list = l->d);
}
static inline void bch_keylist_push(struct keylist *l)
{
l->top = bkey_next(l->top);
}
static inline void bch_keylist_add(struct keylist *l, struct bkey *k)
{
bkey_copy(l->top, k);
bch_keylist_push(l);
}
static inline bool bch_keylist_empty(struct keylist *l)
{
return l->top == (void *) l->list;
}
static inline void bch_keylist_free(struct keylist *l)
{
if (l->list != l->d)
kfree(l->list);
}
void bch_keylist_copy(struct keylist *, struct keylist *);
struct bkey *bch_keylist_pop(struct keylist *);
int bch_keylist_realloc(struct keylist *, int, struct cache_set *);
void bch_bkey_copy_single_ptr(struct bkey *, const struct bkey *,
unsigned);
bool __bch_cut_front(const struct bkey *, struct bkey *);
bool __bch_cut_back(const struct bkey *, struct bkey *);
static inline bool bch_cut_front(const struct bkey *where, struct bkey *k)
{
BUG_ON(bkey_cmp(where, k) > 0);
return __bch_cut_front(where, k);
}
static inline bool bch_cut_back(const struct bkey *where, struct bkey *k)
{
BUG_ON(bkey_cmp(where, &START_KEY(k)) < 0);
return __bch_cut_back(where, k);
}
const char *bch_ptr_status(struct cache_set *, const struct bkey *);
bool __bch_ptr_invalid(struct cache_set *, int level, const struct bkey *);
bool bch_ptr_bad(struct btree *, const struct bkey *);
static inline uint8_t gen_after(uint8_t a, uint8_t b)
{
uint8_t r = a - b;
return r > 128U ? 0 : r;
}
static inline uint8_t ptr_stale(struct cache_set *c, const struct bkey *k,
unsigned i)
{
return gen_after(PTR_BUCKET(c, k, i)->gen, PTR_GEN(k, i));
}
static inline bool ptr_available(struct cache_set *c, const struct bkey *k,
unsigned i)
{
return (PTR_DEV(k, i) < MAX_CACHES_PER_SET) && PTR_CACHE(c, k, i);
}
typedef bool (*ptr_filter_fn)(struct btree *, const struct bkey *);
struct bkey *bch_next_recurse_key(struct btree *, struct bkey *);
struct bkey *bch_btree_iter_next(struct btree_iter *);
struct bkey *bch_btree_iter_next_filter(struct btree_iter *,
struct btree *, ptr_filter_fn);
void bch_btree_iter_push(struct btree_iter *, struct bkey *, struct bkey *);
struct bkey *__bch_btree_iter_init(struct btree *, struct btree_iter *,
struct bkey *, struct bset_tree *);
/* 32 bits total: */
#define BKEY_MID_BITS 3
#define BKEY_EXPONENT_BITS 7
#define BKEY_MANTISSA_BITS 22
#define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1)
struct bkey_float {
unsigned exponent:BKEY_EXPONENT_BITS;
unsigned m:BKEY_MID_BITS;
unsigned mantissa:BKEY_MANTISSA_BITS;
} __packed;
/*
* BSET_CACHELINE was originally intended to match the hardware cacheline size -
* it used to be 64, but I realized the lookup code would touch slightly less
* memory if it was 128.
*
* It definites the number of bytes (in struct bset) per struct bkey_float in
* the auxiliar search tree - when we're done searching the bset_float tree we
* have this many bytes left that we do a linear search over.
*
* Since (after level 5) every level of the bset_tree is on a new cacheline,
* we're touching one fewer cacheline in the bset tree in exchange for one more
* cacheline in the linear search - but the linear search might stop before it
* gets to the second cacheline.
*/
#define BSET_CACHELINE 128
#define bset_tree_space(b) (btree_data_space(b) / BSET_CACHELINE)
#define bset_tree_bytes(b) (bset_tree_space(b) * sizeof(struct bkey_float))
#define bset_prev_bytes(b) (bset_tree_space(b) * sizeof(uint8_t))
void bch_bset_init_next(struct btree *);
void bch_bset_fix_invalidated_key(struct btree *, struct bkey *);
void bch_bset_fix_lookup_table(struct btree *, struct bkey *);
struct bkey *__bch_bset_search(struct btree *, struct bset_tree *,
const struct bkey *);
static inline struct bkey *bch_bset_search(struct btree *b, struct bset_tree *t,
const struct bkey *search)
{
return search ? __bch_bset_search(b, t, search) : t->data->start;
}
bool bch_bkey_try_merge(struct btree *, struct bkey *, struct bkey *);
void bch_btree_sort_lazy(struct btree *);
void bch_btree_sort_into(struct btree *, struct btree *);
void bch_btree_sort_and_fix_extents(struct btree *, struct btree_iter *);
void bch_btree_sort_partial(struct btree *, unsigned);
static inline void bch_btree_sort(struct btree *b)
{
bch_btree_sort_partial(b, 0);
}
int bch_bset_print_stats(struct cache_set *, char *);
#endif

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#ifndef _BCACHE_BTREE_H
#define _BCACHE_BTREE_H
/*
* THE BTREE:
*
* At a high level, bcache's btree is relatively standard b+ tree. All keys and
* pointers are in the leaves; interior nodes only have pointers to the child
* nodes.
*
* In the interior nodes, a struct bkey always points to a child btree node, and
* the key is the highest key in the child node - except that the highest key in
* an interior node is always MAX_KEY. The size field refers to the size on disk
* of the child node - this would allow us to have variable sized btree nodes
* (handy for keeping the depth of the btree 1 by expanding just the root).
*
* Btree nodes are themselves log structured, but this is hidden fairly
* thoroughly. Btree nodes on disk will in practice have extents that overlap
* (because they were written at different times), but in memory we never have
* overlapping extents - when we read in a btree node from disk, the first thing
* we do is resort all the sets of keys with a mergesort, and in the same pass
* we check for overlapping extents and adjust them appropriately.
*
* struct btree_op is a central interface to the btree code. It's used for
* specifying read vs. write locking, and the embedded closure is used for
* waiting on IO or reserve memory.
*
* BTREE CACHE:
*
* Btree nodes are cached in memory; traversing the btree might require reading
* in btree nodes which is handled mostly transparently.
*
* bch_btree_node_get() looks up a btree node in the cache and reads it in from
* disk if necessary. This function is almost never called directly though - the
* btree() macro is used to get a btree node, call some function on it, and
* unlock the node after the function returns.
*
* The root is special cased - it's taken out of the cache's lru (thus pinning
* it in memory), so we can find the root of the btree by just dereferencing a
* pointer instead of looking it up in the cache. This makes locking a bit
* tricky, since the root pointer is protected by the lock in the btree node it
* points to - the btree_root() macro handles this.
*
* In various places we must be able to allocate memory for multiple btree nodes
* in order to make forward progress. To do this we use the btree cache itself
* as a reserve; if __get_free_pages() fails, we'll find a node in the btree
* cache we can reuse. We can't allow more than one thread to be doing this at a
* time, so there's a lock, implemented by a pointer to the btree_op closure -
* this allows the btree_root() macro to implicitly release this lock.
*
* BTREE IO:
*
* Btree nodes never have to be explicitly read in; bch_btree_node_get() handles
* this.
*
* For writing, we have two btree_write structs embeddded in struct btree - one
* write in flight, and one being set up, and we toggle between them.
*
* Writing is done with a single function - bch_btree_write() really serves two
* different purposes and should be broken up into two different functions. When
* passing now = false, it merely indicates that the node is now dirty - calling
* it ensures that the dirty keys will be written at some point in the future.
*
* When passing now = true, bch_btree_write() causes a write to happen
* "immediately" (if there was already a write in flight, it'll cause the write
* to happen as soon as the previous write completes). It returns immediately
* though - but it takes a refcount on the closure in struct btree_op you passed
* to it, so a closure_sync() later can be used to wait for the write to
* complete.
*
* This is handy because btree_split() and garbage collection can issue writes
* in parallel, reducing the amount of time they have to hold write locks.
*
* LOCKING:
*
* When traversing the btree, we may need write locks starting at some level -
* inserting a key into the btree will typically only require a write lock on
* the leaf node.
*
* This is specified with the lock field in struct btree_op; lock = 0 means we
* take write locks at level <= 0, i.e. only leaf nodes. bch_btree_node_get()
* checks this field and returns the node with the appropriate lock held.
*
* If, after traversing the btree, the insertion code discovers it has to split
* then it must restart from the root and take new locks - to do this it changes
* the lock field and returns -EINTR, which causes the btree_root() macro to
* loop.
*
* Handling cache misses require a different mechanism for upgrading to a write
* lock. We do cache lookups with only a read lock held, but if we get a cache
* miss and we wish to insert this data into the cache, we have to insert a
* placeholder key to detect races - otherwise, we could race with a write and
* overwrite the data that was just written to the cache with stale data from
* the backing device.
*
* For this we use a sequence number that write locks and unlocks increment - to
* insert the check key it unlocks the btree node and then takes a write lock,
* and fails if the sequence number doesn't match.
*/
#include "bset.h"
#include "debug.h"
struct btree_write {
struct closure *owner;
atomic_t *journal;
/* If btree_split() frees a btree node, it writes a new pointer to that
* btree node indicating it was freed; it takes a refcount on
* c->prio_blocked because we can't write the gens until the new
* pointer is on disk. This allows btree_write_endio() to release the
* refcount that btree_split() took.
*/
int prio_blocked;
};
struct btree {
/* Hottest entries first */
struct hlist_node hash;
/* Key/pointer for this btree node */
BKEY_PADDED(key);
/* Single bit - set when accessed, cleared by shrinker */
unsigned long accessed;
unsigned long seq;
struct rw_semaphore lock;
struct cache_set *c;
unsigned long flags;
uint16_t written; /* would be nice to kill */
uint8_t level;
uint8_t nsets;
uint8_t page_order;
/*
* Set of sorted keys - the real btree node - plus a binary search tree
*
* sets[0] is special; set[0]->tree, set[0]->prev and set[0]->data point
* to the memory we have allocated for this btree node. Additionally,
* set[0]->data points to the entire btree node as it exists on disk.
*/
struct bset_tree sets[MAX_BSETS];
/* Used to refcount bio splits, also protects b->bio */
struct closure_with_waitlist io;
/* Gets transferred to w->prio_blocked - see the comment there */
int prio_blocked;
struct list_head list;
struct delayed_work work;
uint64_t io_start_time;
struct btree_write writes[2];
struct bio *bio;
};
#define BTREE_FLAG(flag) \
static inline bool btree_node_ ## flag(struct btree *b) \
{ return test_bit(BTREE_NODE_ ## flag, &b->flags); } \
\
static inline void set_btree_node_ ## flag(struct btree *b) \
{ set_bit(BTREE_NODE_ ## flag, &b->flags); } \
enum btree_flags {
BTREE_NODE_read_done,
BTREE_NODE_io_error,
BTREE_NODE_dirty,
BTREE_NODE_write_idx,
};
BTREE_FLAG(read_done);
BTREE_FLAG(io_error);
BTREE_FLAG(dirty);
BTREE_FLAG(write_idx);
static inline struct btree_write *btree_current_write(struct btree *b)
{
return b->writes + btree_node_write_idx(b);
}
static inline struct btree_write *btree_prev_write(struct btree *b)
{
return b->writes + (btree_node_write_idx(b) ^ 1);
}
static inline unsigned bset_offset(struct btree *b, struct bset *i)
{
return (((size_t) i) - ((size_t) b->sets->data)) >> 9;
}
static inline struct bset *write_block(struct btree *b)
{
return ((void *) b->sets[0].data) + b->written * block_bytes(b->c);
}
static inline bool bset_written(struct btree *b, struct bset_tree *t)
{
return t->data < write_block(b);
}
static inline bool bkey_written(struct btree *b, struct bkey *k)
{
return k < write_block(b)->start;
}
static inline void set_gc_sectors(struct cache_set *c)
{
atomic_set(&c->sectors_to_gc, c->sb.bucket_size * c->nbuckets / 8);
}
static inline bool bch_ptr_invalid(struct btree *b, const struct bkey *k)
{
return __bch_ptr_invalid(b->c, b->level, k);
}
static inline struct bkey *bch_btree_iter_init(struct btree *b,
struct btree_iter *iter,
struct bkey *search)
{
return __bch_btree_iter_init(b, iter, search, b->sets);
}
/* Looping macros */
#define for_each_cached_btree(b, c, iter) \
for (iter = 0; \
iter < ARRAY_SIZE((c)->bucket_hash); \
iter++) \
hlist_for_each_entry_rcu((b), (c)->bucket_hash + iter, hash)
#define for_each_key_filter(b, k, iter, filter) \
for (bch_btree_iter_init((b), (iter), NULL); \
((k) = bch_btree_iter_next_filter((iter), b, filter));)
#define for_each_key(b, k, iter) \
for (bch_btree_iter_init((b), (iter), NULL); \
((k) = bch_btree_iter_next(iter));)
/* Recursing down the btree */
struct btree_op {
struct closure cl;
struct cache_set *c;
/* Journal entry we have a refcount on */
atomic_t *journal;
/* Bio to be inserted into the cache */
struct bio *cache_bio;
unsigned inode;
uint16_t write_prio;
/* Btree level at which we start taking write locks */
short lock;
/* Btree insertion type */
enum {
BTREE_INSERT,
BTREE_REPLACE
} type:8;
unsigned csum:1;
unsigned skip:1;
unsigned flush_journal:1;
unsigned insert_data_done:1;
unsigned lookup_done:1;
unsigned insert_collision:1;
/* Anything after this point won't get zeroed in do_bio_hook() */
/* Keys to be inserted */
struct keylist keys;
BKEY_PADDED(replace);
};
void bch_btree_op_init_stack(struct btree_op *);
static inline void rw_lock(bool w, struct btree *b, int level)
{
w ? down_write_nested(&b->lock, level + 1)
: down_read_nested(&b->lock, level + 1);
if (w)
b->seq++;
}
static inline void rw_unlock(bool w, struct btree *b)
{
#ifdef CONFIG_BCACHE_EDEBUG
unsigned i;
if (w &&
b->key.ptr[0] &&
btree_node_read_done(b))
for (i = 0; i <= b->nsets; i++)
bch_check_key_order(b, b->sets[i].data);
#endif
if (w)
b->seq++;
(w ? up_write : up_read)(&b->lock);
}
#define insert_lock(s, b) ((b)->level <= (s)->lock)
/*
* These macros are for recursing down the btree - they handle the details of
* locking and looking up nodes in the cache for you. They're best treated as
* mere syntax when reading code that uses them.
*
* op->lock determines whether we take a read or a write lock at a given depth.
* If you've got a read lock and find that you need a write lock (i.e. you're
* going to have to split), set op->lock and return -EINTR; btree_root() will
* call you again and you'll have the correct lock.
*/
/**
* btree - recurse down the btree on a specified key
* @fn: function to call, which will be passed the child node
* @key: key to recurse on
* @b: parent btree node
* @op: pointer to struct btree_op
*/
#define btree(fn, key, b, op, ...) \
({ \
int _r, l = (b)->level - 1; \
bool _w = l <= (op)->lock; \
struct btree *_b = bch_btree_node_get((b)->c, key, l, op); \
if (!IS_ERR(_b)) { \
_r = bch_btree_ ## fn(_b, op, ##__VA_ARGS__); \
rw_unlock(_w, _b); \
} else \
_r = PTR_ERR(_b); \
_r; \
})
/**
* btree_root - call a function on the root of the btree
* @fn: function to call, which will be passed the child node
* @c: cache set
* @op: pointer to struct btree_op
*/
#define btree_root(fn, c, op, ...) \
({ \
int _r = -EINTR; \
do { \
struct btree *_b = (c)->root; \
bool _w = insert_lock(op, _b); \
rw_lock(_w, _b, _b->level); \
if (_b == (c)->root && \
_w == insert_lock(op, _b)) \
_r = bch_btree_ ## fn(_b, op, ##__VA_ARGS__); \
rw_unlock(_w, _b); \
bch_cannibalize_unlock(c, &(op)->cl); \
} while (_r == -EINTR); \
\
_r; \
})
static inline bool should_split(struct btree *b)
{
struct bset *i = write_block(b);
return b->written >= btree_blocks(b) ||
(i->seq == b->sets[0].data->seq &&
b->written + __set_blocks(i, i->keys + 15, b->c)
> btree_blocks(b));
}
void bch_btree_read_done(struct closure *);
void bch_btree_read(struct btree *);
void bch_btree_write(struct btree *b, bool now, struct btree_op *op);
void bch_cannibalize_unlock(struct cache_set *, struct closure *);
void bch_btree_set_root(struct btree *);
struct btree *bch_btree_node_alloc(struct cache_set *, int, struct closure *);
struct btree *bch_btree_node_get(struct cache_set *, struct bkey *,
int, struct btree_op *);
bool bch_btree_insert_keys(struct btree *, struct btree_op *);
bool bch_btree_insert_check_key(struct btree *, struct btree_op *,
struct bio *);
int bch_btree_insert(struct btree_op *, struct cache_set *);
int bch_btree_search_recurse(struct btree *, struct btree_op *);
void bch_queue_gc(struct cache_set *);
size_t bch_btree_gc_finish(struct cache_set *);
void bch_moving_gc(struct closure *);
int bch_btree_check(struct cache_set *, struct btree_op *);
uint8_t __bch_btree_mark_key(struct cache_set *, int, struct bkey *);
void bch_keybuf_init(struct keybuf *, keybuf_pred_fn *);
void bch_refill_keybuf(struct cache_set *, struct keybuf *, struct bkey *);
bool bch_keybuf_check_overlapping(struct keybuf *, struct bkey *,
struct bkey *);
void bch_keybuf_del(struct keybuf *, struct keybuf_key *);
struct keybuf_key *bch_keybuf_next(struct keybuf *);
struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *,
struct keybuf *, struct bkey *);
#endif

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/*
* Asynchronous refcounty things
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include "closure.h"
void closure_queue(struct closure *cl)
{
struct workqueue_struct *wq = cl->wq;
if (wq) {
INIT_WORK(&cl->work, cl->work.func);
BUG_ON(!queue_work(wq, &cl->work));
} else
cl->fn(cl);
}
EXPORT_SYMBOL_GPL(closure_queue);
#define CL_FIELD(type, field) \
case TYPE_ ## type: \
return &container_of(cl, struct type, cl)->field
static struct closure_waitlist *closure_waitlist(struct closure *cl)
{
switch (cl->type) {
CL_FIELD(closure_with_waitlist, wait);
CL_FIELD(closure_with_waitlist_and_timer, wait);
default:
return NULL;
}
}
static struct timer_list *closure_timer(struct closure *cl)
{
switch (cl->type) {
CL_FIELD(closure_with_timer, timer);
CL_FIELD(closure_with_waitlist_and_timer, timer);
default:
return NULL;
}
}
static inline void closure_put_after_sub(struct closure *cl, int flags)
{
int r = flags & CLOSURE_REMAINING_MASK;
BUG_ON(flags & CLOSURE_GUARD_MASK);
BUG_ON(!r && (flags & ~(CLOSURE_DESTRUCTOR|CLOSURE_BLOCKING)));
/* Must deliver precisely one wakeup */
if (r == 1 && (flags & CLOSURE_SLEEPING))
wake_up_process(cl->task);
if (!r) {
if (cl->fn && !(flags & CLOSURE_DESTRUCTOR)) {
/* CLOSURE_BLOCKING might be set - clear it */
atomic_set(&cl->remaining,
CLOSURE_REMAINING_INITIALIZER);
closure_queue(cl);
} else {
struct closure *parent = cl->parent;
struct closure_waitlist *wait = closure_waitlist(cl);
closure_debug_destroy(cl);
atomic_set(&cl->remaining, -1);
if (wait)
closure_wake_up(wait);
if (cl->fn)
cl->fn(cl);
if (parent)
closure_put(parent);
}
}
}
/* For clearing flags with the same atomic op as a put */
void closure_sub(struct closure *cl, int v)
{
closure_put_after_sub(cl, atomic_sub_return(v, &cl->remaining));
}
EXPORT_SYMBOL_GPL(closure_sub);
void closure_put(struct closure *cl)
{
closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
}
EXPORT_SYMBOL_GPL(closure_put);
static void set_waiting(struct closure *cl, unsigned long f)
{
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
cl->waiting_on = f;
#endif
}
void __closure_wake_up(struct closure_waitlist *wait_list)
{
struct llist_node *list;
struct closure *cl;
struct llist_node *reverse = NULL;
list = llist_del_all(&wait_list->list);
/* We first reverse the list to preserve FIFO ordering and fairness */
while (list) {
struct llist_node *t = list;
list = llist_next(list);
t->next = reverse;
reverse = t;
}
/* Then do the wakeups */
while (reverse) {
cl = container_of(reverse, struct closure, list);
reverse = llist_next(reverse);
set_waiting(cl, 0);
closure_sub(cl, CLOSURE_WAITING + 1);
}
}
EXPORT_SYMBOL_GPL(__closure_wake_up);
bool closure_wait(struct closure_waitlist *list, struct closure *cl)
{
if (atomic_read(&cl->remaining) & CLOSURE_WAITING)
return false;
set_waiting(cl, _RET_IP_);
atomic_add(CLOSURE_WAITING + 1, &cl->remaining);
llist_add(&cl->list, &list->list);
return true;
}
EXPORT_SYMBOL_GPL(closure_wait);
/**
* closure_sync() - sleep until a closure a closure has nothing left to wait on
*
* Sleeps until the refcount hits 1 - the thread that's running the closure owns
* the last refcount.
*/
void closure_sync(struct closure *cl)
{
while (1) {
__closure_start_sleep(cl);
closure_set_ret_ip(cl);
if ((atomic_read(&cl->remaining) &
CLOSURE_REMAINING_MASK) == 1)
break;
schedule();
}
__closure_end_sleep(cl);
}
EXPORT_SYMBOL_GPL(closure_sync);
/**
* closure_trylock() - try to acquire the closure, without waiting
* @cl: closure to lock
*
* Returns true if the closure was succesfully locked.
*/
bool closure_trylock(struct closure *cl, struct closure *parent)
{
if (atomic_cmpxchg(&cl->remaining, -1,
CLOSURE_REMAINING_INITIALIZER) != -1)
return false;
closure_set_ret_ip(cl);
smp_mb();
cl->parent = parent;
if (parent)
closure_get(parent);
closure_debug_create(cl);
return true;
}
EXPORT_SYMBOL_GPL(closure_trylock);
void __closure_lock(struct closure *cl, struct closure *parent,
struct closure_waitlist *wait_list)
{
struct closure wait;
closure_init_stack(&wait);
while (1) {
if (closure_trylock(cl, parent))
return;
closure_wait_event_sync(wait_list, &wait,
atomic_read(&cl->remaining) == -1);
}
}
EXPORT_SYMBOL_GPL(__closure_lock);
static void closure_delay_timer_fn(unsigned long data)
{
struct closure *cl = (struct closure *) data;
closure_sub(cl, CLOSURE_TIMER + 1);
}
void do_closure_timer_init(struct closure *cl)
{
struct timer_list *timer = closure_timer(cl);
init_timer(timer);
timer->data = (unsigned long) cl;
timer->function = closure_delay_timer_fn;
}
EXPORT_SYMBOL_GPL(do_closure_timer_init);
bool __closure_delay(struct closure *cl, unsigned long delay,
struct timer_list *timer)
{
if (atomic_read(&cl->remaining) & CLOSURE_TIMER)
return false;
BUG_ON(timer_pending(timer));
timer->expires = jiffies + delay;
atomic_add(CLOSURE_TIMER + 1, &cl->remaining);
add_timer(timer);
return true;
}
EXPORT_SYMBOL_GPL(__closure_delay);
void __closure_flush(struct closure *cl, struct timer_list *timer)
{
if (del_timer(timer))
closure_sub(cl, CLOSURE_TIMER + 1);
}
EXPORT_SYMBOL_GPL(__closure_flush);
void __closure_flush_sync(struct closure *cl, struct timer_list *timer)
{
if (del_timer_sync(timer))
closure_sub(cl, CLOSURE_TIMER + 1);
}
EXPORT_SYMBOL_GPL(__closure_flush_sync);
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
static LIST_HEAD(closure_list);
static DEFINE_SPINLOCK(closure_list_lock);
void closure_debug_create(struct closure *cl)
{
unsigned long flags;
BUG_ON(cl->magic == CLOSURE_MAGIC_ALIVE);
cl->magic = CLOSURE_MAGIC_ALIVE;
spin_lock_irqsave(&closure_list_lock, flags);
list_add(&cl->all, &closure_list);
spin_unlock_irqrestore(&closure_list_lock, flags);
}
EXPORT_SYMBOL_GPL(closure_debug_create);
void closure_debug_destroy(struct closure *cl)
{
unsigned long flags;
BUG_ON(cl->magic != CLOSURE_MAGIC_ALIVE);
cl->magic = CLOSURE_MAGIC_DEAD;
spin_lock_irqsave(&closure_list_lock, flags);
list_del(&cl->all);
spin_unlock_irqrestore(&closure_list_lock, flags);
}
EXPORT_SYMBOL_GPL(closure_debug_destroy);
static struct dentry *debug;
#define work_data_bits(work) ((unsigned long *)(&(work)->data))
static int debug_seq_show(struct seq_file *f, void *data)
{
struct closure *cl;
spin_lock_irq(&closure_list_lock);
list_for_each_entry(cl, &closure_list, all) {
int r = atomic_read(&cl->remaining);
seq_printf(f, "%p: %pF -> %pf p %p r %i ",
cl, (void *) cl->ip, cl->fn, cl->parent,
r & CLOSURE_REMAINING_MASK);
seq_printf(f, "%s%s%s%s%s%s\n",
test_bit(WORK_STRUCT_PENDING,
work_data_bits(&cl->work)) ? "Q" : "",
r & CLOSURE_RUNNING ? "R" : "",
r & CLOSURE_BLOCKING ? "B" : "",
r & CLOSURE_STACK ? "S" : "",
r & CLOSURE_SLEEPING ? "Sl" : "",
r & CLOSURE_TIMER ? "T" : "");
if (r & CLOSURE_WAITING)
seq_printf(f, " W %pF\n",
(void *) cl->waiting_on);
seq_printf(f, "\n");
}
spin_unlock_irq(&closure_list_lock);
return 0;
}
static int debug_seq_open(struct inode *inode, struct file *file)
{
return single_open(file, debug_seq_show, NULL);
}
static const struct file_operations debug_ops = {
.owner = THIS_MODULE,
.open = debug_seq_open,
.read = seq_read,
.release = single_release
};
void __init closure_debug_init(void)
{
debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
}
#endif
MODULE_AUTHOR("Kent Overstreet <koverstreet@google.com>");
MODULE_LICENSE("GPL");

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#ifndef _LINUX_CLOSURE_H
#define _LINUX_CLOSURE_H
#include <linux/llist.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
/*
* Closure is perhaps the most overused and abused term in computer science, but
* since I've been unable to come up with anything better you're stuck with it
* again.
*
* What are closures?
*
* They embed a refcount. The basic idea is they count "things that are in
* progress" - in flight bios, some other thread that's doing something else -
* anything you might want to wait on.
*
* The refcount may be manipulated with closure_get() and closure_put().
* closure_put() is where many of the interesting things happen, when it causes
* the refcount to go to 0.
*
* Closures can be used to wait on things both synchronously and asynchronously,
* and synchronous and asynchronous use can be mixed without restriction. To
* wait synchronously, use closure_sync() - you will sleep until your closure's
* refcount hits 1.
*
* To wait asynchronously, use
* continue_at(cl, next_function, workqueue);
*
* passing it, as you might expect, the function to run when nothing is pending
* and the workqueue to run that function out of.
*
* continue_at() also, critically, is a macro that returns the calling function.
* There's good reason for this.
*
* To use safely closures asynchronously, they must always have a refcount while
* they are running owned by the thread that is running them. Otherwise, suppose
* you submit some bios and wish to have a function run when they all complete:
*
* foo_endio(struct bio *bio, int error)
* {
* closure_put(cl);
* }
*
* closure_init(cl);
*
* do_stuff();
* closure_get(cl);
* bio1->bi_endio = foo_endio;
* bio_submit(bio1);
*
* do_more_stuff();
* closure_get(cl);
* bio2->bi_endio = foo_endio;
* bio_submit(bio2);
*
* continue_at(cl, complete_some_read, system_wq);
*
* If closure's refcount started at 0, complete_some_read() could run before the
* second bio was submitted - which is almost always not what you want! More
* importantly, it wouldn't be possible to say whether the original thread or
* complete_some_read()'s thread owned the closure - and whatever state it was
* associated with!
*
* So, closure_init() initializes a closure's refcount to 1 - and when a
* closure_fn is run, the refcount will be reset to 1 first.
*
* Then, the rule is - if you got the refcount with closure_get(), release it
* with closure_put() (i.e, in a bio->bi_endio function). If you have a refcount
* on a closure because you called closure_init() or you were run out of a
* closure - _always_ use continue_at(). Doing so consistently will help
* eliminate an entire class of particularly pernicious races.
*
* For a closure to wait on an arbitrary event, we need to introduce waitlists:
*
* struct closure_waitlist list;
* closure_wait_event(list, cl, condition);
* closure_wake_up(wait_list);
*
* These work analagously to wait_event() and wake_up() - except that instead of
* operating on the current thread (for wait_event()) and lists of threads, they
* operate on an explicit closure and lists of closures.
*
* Because it's a closure we can now wait either synchronously or
* asynchronously. closure_wait_event() returns the current value of the
* condition, and if it returned false continue_at() or closure_sync() can be
* used to wait for it to become true.
*
* It's useful for waiting on things when you can't sleep in the context in
* which you must check the condition (perhaps a spinlock held, or you might be
* beneath generic_make_request() - in which case you can't sleep on IO).
*
* closure_wait_event() will wait either synchronously or asynchronously,
* depending on whether the closure is in blocking mode or not. You can pick a
* mode explicitly with closure_wait_event_sync() and
* closure_wait_event_async(), which do just what you might expect.
*
* Lastly, you might have a wait list dedicated to a specific event, and have no
* need for specifying the condition - you just want to wait until someone runs
* closure_wake_up() on the appropriate wait list. In that case, just use
* closure_wait(). It will return either true or false, depending on whether the
* closure was already on a wait list or not - a closure can only be on one wait
* list at a time.
*
* Parents:
*
* closure_init() takes two arguments - it takes the closure to initialize, and
* a (possibly null) parent.
*
* If parent is non null, the new closure will have a refcount for its lifetime;
* a closure is considered to be "finished" when its refcount hits 0 and the
* function to run is null. Hence
*
* continue_at(cl, NULL, NULL);
*
* returns up the (spaghetti) stack of closures, precisely like normal return
* returns up the C stack. continue_at() with non null fn is better thought of
* as doing a tail call.
*
* All this implies that a closure should typically be embedded in a particular
* struct (which its refcount will normally control the lifetime of), and that
* struct can very much be thought of as a stack frame.
*
* Locking:
*
* Closures are based on work items but they can be thought of as more like
* threads - in that like threads and unlike work items they have a well
* defined lifetime; they are created (with closure_init()) and eventually
* complete after a continue_at(cl, NULL, NULL).
*
* Suppose you've got some larger structure with a closure embedded in it that's
* used for periodically doing garbage collection. You only want one garbage
* collection happening at a time, so the natural thing to do is protect it with
* a lock. However, it's difficult to use a lock protecting a closure correctly
* because the unlock should come after the last continue_to() (additionally, if
* you're using the closure asynchronously a mutex won't work since a mutex has
* to be unlocked by the same process that locked it).
*
* So to make it less error prone and more efficient, we also have the ability
* to use closures as locks:
*
* closure_init_unlocked();
* closure_trylock();
*
* That's all we need for trylock() - the last closure_put() implicitly unlocks
* it for you. But for closure_lock(), we also need a wait list:
*
* struct closure_with_waitlist frobnicator_cl;
*
* closure_init_unlocked(&frobnicator_cl);
* closure_lock(&frobnicator_cl);
*
* A closure_with_waitlist embeds a closure and a wait list - much like struct
* delayed_work embeds a work item and a timer_list. The important thing is, use
* it exactly like you would a regular closure and closure_put() will magically
* handle everything for you.
*
* We've got closures that embed timers, too. They're called, appropriately
* enough:
* struct closure_with_timer;
*
* This gives you access to closure_delay(). It takes a refcount for a specified
* number of jiffies - you could then call closure_sync() (for a slightly
* convoluted version of msleep()) or continue_at() - which gives you the same
* effect as using a delayed work item, except you can reuse the work_struct
* already embedded in struct closure.
*
* Lastly, there's struct closure_with_waitlist_and_timer. It does what you
* probably expect, if you happen to need the features of both. (You don't
* really want to know how all this is implemented, but if I've done my job
* right you shouldn't have to care).
*/
struct closure;
typedef void (closure_fn) (struct closure *);
struct closure_waitlist {
struct llist_head list;
};
enum closure_type {
TYPE_closure = 0,
TYPE_closure_with_waitlist = 1,
TYPE_closure_with_timer = 2,
TYPE_closure_with_waitlist_and_timer = 3,
MAX_CLOSURE_TYPE = 3,
};
enum closure_state {
/*
* CLOSURE_BLOCKING: Causes closure_wait_event() to block, instead of
* waiting asynchronously
*
* CLOSURE_WAITING: Set iff the closure is on a waitlist. Must be set by
* the thread that owns the closure, and cleared by the thread that's
* waking up the closure.
*
* CLOSURE_SLEEPING: Must be set before a thread uses a closure to sleep
* - indicates that cl->task is valid and closure_put() may wake it up.
* Only set or cleared by the thread that owns the closure.
*
* CLOSURE_TIMER: Analagous to CLOSURE_WAITING, indicates that a closure
* has an outstanding timer. Must be set by the thread that owns the
* closure, and cleared by the timer function when the timer goes off.
*
* The rest are for debugging and don't affect behaviour:
*
* CLOSURE_RUNNING: Set when a closure is running (i.e. by
* closure_init() and when closure_put() runs then next function), and
* must be cleared before remaining hits 0. Primarily to help guard
* against incorrect usage and accidentally transferring references.
* continue_at() and closure_return() clear it for you, if you're doing
* something unusual you can use closure_set_dead() which also helps
* annotate where references are being transferred.
*
* CLOSURE_STACK: Sanity check - remaining should never hit 0 on a
* closure with this flag set
*/
CLOSURE_BITS_START = (1 << 19),
CLOSURE_DESTRUCTOR = (1 << 19),
CLOSURE_BLOCKING = (1 << 21),
CLOSURE_WAITING = (1 << 23),
CLOSURE_SLEEPING = (1 << 25),
CLOSURE_TIMER = (1 << 27),
CLOSURE_RUNNING = (1 << 29),
CLOSURE_STACK = (1 << 31),
};
#define CLOSURE_GUARD_MASK \
((CLOSURE_DESTRUCTOR|CLOSURE_BLOCKING|CLOSURE_WAITING| \
CLOSURE_SLEEPING|CLOSURE_TIMER|CLOSURE_RUNNING|CLOSURE_STACK) << 1)
#define CLOSURE_REMAINING_MASK (CLOSURE_BITS_START - 1)
#define CLOSURE_REMAINING_INITIALIZER (1|CLOSURE_RUNNING)
struct closure {
union {
struct {
struct workqueue_struct *wq;
struct task_struct *task;
struct llist_node list;
closure_fn *fn;
};
struct work_struct work;
};
struct closure *parent;
atomic_t remaining;
enum closure_type type;
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
#define CLOSURE_MAGIC_DEAD 0xc054dead
#define CLOSURE_MAGIC_ALIVE 0xc054a11e
unsigned magic;
struct list_head all;
unsigned long ip;
unsigned long waiting_on;
#endif
};
struct closure_with_waitlist {
struct closure cl;
struct closure_waitlist wait;
};
struct closure_with_timer {
struct closure cl;
struct timer_list timer;
};
struct closure_with_waitlist_and_timer {
struct closure cl;
struct closure_waitlist wait;
struct timer_list timer;
};
extern unsigned invalid_closure_type(void);
#define __CLOSURE_TYPE(cl, _t) \
__builtin_types_compatible_p(typeof(cl), struct _t) \
? TYPE_ ## _t : \
#define __closure_type(cl) \
( \
__CLOSURE_TYPE(cl, closure) \
__CLOSURE_TYPE(cl, closure_with_waitlist) \
__CLOSURE_TYPE(cl, closure_with_timer) \
__CLOSURE_TYPE(cl, closure_with_waitlist_and_timer) \
invalid_closure_type() \
)
void closure_sub(struct closure *cl, int v);
void closure_put(struct closure *cl);
void closure_queue(struct closure *cl);
void __closure_wake_up(struct closure_waitlist *list);
bool closure_wait(struct closure_waitlist *list, struct closure *cl);
void closure_sync(struct closure *cl);
bool closure_trylock(struct closure *cl, struct closure *parent);
void __closure_lock(struct closure *cl, struct closure *parent,
struct closure_waitlist *wait_list);
void do_closure_timer_init(struct closure *cl);
bool __closure_delay(struct closure *cl, unsigned long delay,
struct timer_list *timer);
void __closure_flush(struct closure *cl, struct timer_list *timer);
void __closure_flush_sync(struct closure *cl, struct timer_list *timer);
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
void closure_debug_init(void);
void closure_debug_create(struct closure *cl);
void closure_debug_destroy(struct closure *cl);
#else
static inline void closure_debug_init(void) {}
static inline void closure_debug_create(struct closure *cl) {}
static inline void closure_debug_destroy(struct closure *cl) {}
#endif
static inline void closure_set_ip(struct closure *cl)
{
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
cl->ip = _THIS_IP_;
#endif
}
static inline void closure_set_ret_ip(struct closure *cl)
{
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
cl->ip = _RET_IP_;
#endif
}
static inline void closure_get(struct closure *cl)
{
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
BUG_ON((atomic_inc_return(&cl->remaining) &
CLOSURE_REMAINING_MASK) <= 1);
#else
atomic_inc(&cl->remaining);
#endif
}
static inline void closure_set_stopped(struct closure *cl)
{
atomic_sub(CLOSURE_RUNNING, &cl->remaining);
}
static inline bool closure_is_stopped(struct closure *cl)
{
return !(atomic_read(&cl->remaining) & CLOSURE_RUNNING);
}
static inline bool closure_is_unlocked(struct closure *cl)
{
return atomic_read(&cl->remaining) == -1;
}
static inline void do_closure_init(struct closure *cl, struct closure *parent,
bool running)
{
switch (cl->type) {
case TYPE_closure_with_timer:
case TYPE_closure_with_waitlist_and_timer:
do_closure_timer_init(cl);
default:
break;
}
cl->parent = parent;
if (parent)
closure_get(parent);
if (running) {
closure_debug_create(cl);
atomic_set(&cl->remaining, CLOSURE_REMAINING_INITIALIZER);
} else
atomic_set(&cl->remaining, -1);
closure_set_ip(cl);
}
/*
* Hack to get at the embedded closure if there is one, by doing an unsafe cast:
* the result of __closure_type() is thrown away, it's used merely for type
* checking.
*/
#define __to_internal_closure(cl) \
({ \
BUILD_BUG_ON(__closure_type(*cl) > MAX_CLOSURE_TYPE); \
(struct closure *) cl; \
})
#define closure_init_type(cl, parent, running) \
do { \
struct closure *_cl = __to_internal_closure(cl); \
_cl->type = __closure_type(*(cl)); \
do_closure_init(_cl, parent, running); \
} while (0)
/**
* __closure_init() - Initialize a closure, skipping the memset()
*
* May be used instead of closure_init() when memory has already been zeroed.
*/
#define __closure_init(cl, parent) \
closure_init_type(cl, parent, true)
/**
* closure_init() - Initialize a closure, setting the refcount to 1
* @cl: closure to initialize
* @parent: parent of the new closure. cl will take a refcount on it for its
* lifetime; may be NULL.
*/
#define closure_init(cl, parent) \
do { \
memset((cl), 0, sizeof(*(cl))); \
__closure_init(cl, parent); \
} while (0)
static inline void closure_init_stack(struct closure *cl)
{
memset(cl, 0, sizeof(struct closure));
atomic_set(&cl->remaining, CLOSURE_REMAINING_INITIALIZER|
CLOSURE_BLOCKING|CLOSURE_STACK);
}
/**
* closure_init_unlocked() - Initialize a closure but leave it unlocked.
* @cl: closure to initialize
*
* For when the closure will be used as a lock. The closure may not be used
* until after a closure_lock() or closure_trylock().
*/
#define closure_init_unlocked(cl) \
do { \
memset((cl), 0, sizeof(*(cl))); \
closure_init_type(cl, NULL, false); \
} while (0)
/**
* closure_lock() - lock and initialize a closure.
* @cl: the closure to lock
* @parent: the new parent for this closure
*
* The closure must be of one of the types that has a waitlist (otherwise we
* wouldn't be able to sleep on contention).
*
* @parent has exactly the same meaning as in closure_init(); if non null, the
* closure will take a reference on @parent which will be released when it is
* unlocked.
*/
#define closure_lock(cl, parent) \
__closure_lock(__to_internal_closure(cl), parent, &(cl)->wait)
/**
* closure_delay() - delay some number of jiffies
* @cl: the closure that will sleep
* @delay: the delay in jiffies
*
* Takes a refcount on @cl which will be released after @delay jiffies; this may
* be used to have a function run after a delay with continue_at(), or
* closure_sync() may be used for a convoluted version of msleep().
*/
#define closure_delay(cl, delay) \
__closure_delay(__to_internal_closure(cl), delay, &(cl)->timer)
#define closure_flush(cl) \
__closure_flush(__to_internal_closure(cl), &(cl)->timer)
#define closure_flush_sync(cl) \
__closure_flush_sync(__to_internal_closure(cl), &(cl)->timer)
static inline void __closure_end_sleep(struct closure *cl)
{
__set_current_state(TASK_RUNNING);
if (atomic_read(&cl->remaining) & CLOSURE_SLEEPING)
atomic_sub(CLOSURE_SLEEPING, &cl->remaining);
}
static inline void __closure_start_sleep(struct closure *cl)
{
closure_set_ip(cl);
cl->task = current;
set_current_state(TASK_UNINTERRUPTIBLE);
if (!(atomic_read(&cl->remaining) & CLOSURE_SLEEPING))
atomic_add(CLOSURE_SLEEPING, &cl->remaining);
}
/**
* closure_blocking() - returns true if the closure is in blocking mode.
*
* If a closure is in blocking mode, closure_wait_event() will sleep until the
* condition is true instead of waiting asynchronously.
*/
static inline bool closure_blocking(struct closure *cl)
{
return atomic_read(&cl->remaining) & CLOSURE_BLOCKING;
}
/**
* set_closure_blocking() - put a closure in blocking mode.
*
* If a closure is in blocking mode, closure_wait_event() will sleep until the
* condition is true instead of waiting asynchronously.
*
* Not thread safe - can only be called by the thread running the closure.
*/
static inline void set_closure_blocking(struct closure *cl)
{
if (!closure_blocking(cl))
atomic_add(CLOSURE_BLOCKING, &cl->remaining);
}
/*
* Not thread safe - can only be called by the thread running the closure.
*/
static inline void clear_closure_blocking(struct closure *cl)
{
if (closure_blocking(cl))
atomic_sub(CLOSURE_BLOCKING, &cl->remaining);
}
/**
* closure_wake_up() - wake up all closures on a wait list.
*/
static inline void closure_wake_up(struct closure_waitlist *list)
{
smp_mb();
__closure_wake_up(list);
}
/*
* Wait on an event, synchronously or asynchronously - analogous to wait_event()
* but for closures.
*
* The loop is oddly structured so as to avoid a race; we must check the
* condition again after we've added ourself to the waitlist. We know if we were
* already on the waitlist because closure_wait() returns false; thus, we only
* schedule or break if closure_wait() returns false. If it returns true, we
* just loop again - rechecking the condition.
*
* The __closure_wake_up() is necessary because we may race with the event
* becoming true; i.e. we see event false -> wait -> recheck condition, but the
* thread that made the event true may have called closure_wake_up() before we
* added ourself to the wait list.
*
* We have to call closure_sync() at the end instead of just
* __closure_end_sleep() because a different thread might've called
* closure_wake_up() before us and gotten preempted before they dropped the
* refcount on our closure. If this was a stack allocated closure, that would be
* bad.
*/
#define __closure_wait_event(list, cl, condition, _block) \
({ \
bool block = _block; \
typeof(condition) ret; \
\
while (1) { \
ret = (condition); \
if (ret) { \
__closure_wake_up(list); \
if (block) \
closure_sync(cl); \
\
break; \
} \
\
if (block) \
__closure_start_sleep(cl); \
\
if (!closure_wait(list, cl)) { \
if (!block) \
break; \
\
schedule(); \
} \
} \
\
ret; \
})
/**
* closure_wait_event() - wait on a condition, synchronously or asynchronously.
* @list: the wait list to wait on
* @cl: the closure that is doing the waiting
* @condition: a C expression for the event to wait for
*
* If the closure is in blocking mode, sleeps until the @condition evaluates to
* true - exactly like wait_event().
*
* If the closure is not in blocking mode, waits asynchronously; if the
* condition is currently false the @cl is put onto @list and returns. @list
* owns a refcount on @cl; closure_sync() or continue_at() may be used later to
* wait for another thread to wake up @list, which drops the refcount on @cl.
*
* Returns the value of @condition; @cl will be on @list iff @condition was
* false.
*
* closure_wake_up(@list) must be called after changing any variable that could
* cause @condition to become true.
*/
#define closure_wait_event(list, cl, condition) \
__closure_wait_event(list, cl, condition, closure_blocking(cl))
#define closure_wait_event_async(list, cl, condition) \
__closure_wait_event(list, cl, condition, false)
#define closure_wait_event_sync(list, cl, condition) \
__closure_wait_event(list, cl, condition, true)
static inline void set_closure_fn(struct closure *cl, closure_fn *fn,
struct workqueue_struct *wq)
{
BUG_ON(object_is_on_stack(cl));
closure_set_ip(cl);
cl->fn = fn;
cl->wq = wq;
/* between atomic_dec() in closure_put() */
smp_mb__before_atomic_dec();
}
#define continue_at(_cl, _fn, _wq) \
do { \
set_closure_fn(_cl, _fn, _wq); \
closure_sub(_cl, CLOSURE_RUNNING + 1); \
return; \
} while (0)
#define closure_return(_cl) continue_at((_cl), NULL, NULL)
#define continue_at_nobarrier(_cl, _fn, _wq) \
do { \
set_closure_fn(_cl, _fn, _wq); \
closure_queue(cl); \
return; \
} while (0)
#define closure_return_with_destructor(_cl, _destructor) \
do { \
set_closure_fn(_cl, _destructor, NULL); \
closure_sub(_cl, CLOSURE_RUNNING - CLOSURE_DESTRUCTOR + 1); \
return; \
} while (0)
static inline void closure_call(struct closure *cl, closure_fn fn,
struct workqueue_struct *wq,
struct closure *parent)
{
closure_init(cl, parent);
continue_at_nobarrier(cl, fn, wq);
}
static inline void closure_trylock_call(struct closure *cl, closure_fn fn,
struct workqueue_struct *wq,
struct closure *parent)
{
if (closure_trylock(cl, parent))
continue_at_nobarrier(cl, fn, wq);
}
#endif /* _LINUX_CLOSURE_H */

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/*
* Assorted bcache debug code
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "request.h"
#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/seq_file.h>
static struct dentry *debug;
const char *bch_ptr_status(struct cache_set *c, const struct bkey *k)
{
unsigned i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i)) {
struct cache *ca = PTR_CACHE(c, k, i);
size_t bucket = PTR_BUCKET_NR(c, k, i);
size_t r = bucket_remainder(c, PTR_OFFSET(k, i));
if (KEY_SIZE(k) + r > c->sb.bucket_size)
return "bad, length too big";
if (bucket < ca->sb.first_bucket)
return "bad, short offset";
if (bucket >= ca->sb.nbuckets)
return "bad, offset past end of device";
if (ptr_stale(c, k, i))
return "stale";
}
if (!bkey_cmp(k, &ZERO_KEY))
return "bad, null key";
if (!KEY_PTRS(k))
return "bad, no pointers";
if (!KEY_SIZE(k))
return "zeroed key";
return "";
}
struct keyprint_hack bch_pkey(const struct bkey *k)
{
unsigned i = 0;
struct keyprint_hack r;
char *out = r.s, *end = r.s + KEYHACK_SIZE;
#define p(...) (out += scnprintf(out, end - out, __VA_ARGS__))
p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_OFFSET(k), KEY_SIZE(k));
if (KEY_PTRS(k))
while (1) {
p("%llu:%llu gen %llu",
PTR_DEV(k, i), PTR_OFFSET(k, i), PTR_GEN(k, i));
if (++i == KEY_PTRS(k))
break;
p(", ");
}
p("]");
if (KEY_DIRTY(k))
p(" dirty");
if (KEY_CSUM(k))
p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]);
#undef p
return r;
}
struct keyprint_hack bch_pbtree(const struct btree *b)
{
struct keyprint_hack r;
snprintf(r.s, 40, "%zu level %i/%i", PTR_BUCKET_NR(b->c, &b->key, 0),
b->level, b->c->root ? b->c->root->level : -1);
return r;
}
#if defined(CONFIG_BCACHE_DEBUG) || defined(CONFIG_BCACHE_EDEBUG)
static bool skipped_backwards(struct btree *b, struct bkey *k)
{
return bkey_cmp(k, (!b->level)
? &START_KEY(bkey_next(k))
: bkey_next(k)) > 0;
}
static void dump_bset(struct btree *b, struct bset *i)
{
struct bkey *k;
unsigned j;
for (k = i->start; k < end(i); k = bkey_next(k)) {
printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
(uint64_t *) k - i->d, i->keys, pkey(k));
for (j = 0; j < KEY_PTRS(k); j++) {
size_t n = PTR_BUCKET_NR(b->c, k, j);
printk(" bucket %zu", n);
if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets)
printk(" prio %i",
PTR_BUCKET(b->c, k, j)->prio);
}
printk(" %s\n", bch_ptr_status(b->c, k));
if (bkey_next(k) < end(i) &&
skipped_backwards(b, k))
printk(KERN_ERR "Key skipped backwards\n");
}
}
#endif
#ifdef CONFIG_BCACHE_DEBUG
void bch_btree_verify(struct btree *b, struct bset *new)
{
struct btree *v = b->c->verify_data;
struct closure cl;
closure_init_stack(&cl);
if (!b->c->verify)
return;
closure_wait_event(&b->io.wait, &cl,
atomic_read(&b->io.cl.remaining) == -1);
mutex_lock(&b->c->verify_lock);
bkey_copy(&v->key, &b->key);
v->written = 0;
v->level = b->level;
bch_btree_read(v);
closure_wait_event(&v->io.wait, &cl,
atomic_read(&b->io.cl.remaining) == -1);
if (new->keys != v->sets[0].data->keys ||
memcmp(new->start,
v->sets[0].data->start,
(void *) end(new) - (void *) new->start)) {
unsigned i, j;
console_lock();
printk(KERN_ERR "*** original memory node:\n");
for (i = 0; i <= b->nsets; i++)
dump_bset(b, b->sets[i].data);
printk(KERN_ERR "*** sorted memory node:\n");
dump_bset(b, new);
printk(KERN_ERR "*** on disk node:\n");
dump_bset(v, v->sets[0].data);
for (j = 0; j < new->keys; j++)
if (new->d[j] != v->sets[0].data->d[j])
break;
console_unlock();
panic("verify failed at %u\n", j);
}
mutex_unlock(&b->c->verify_lock);
}
static void data_verify_endio(struct bio *bio, int error)
{
struct closure *cl = bio->bi_private;
closure_put(cl);
}
void bch_data_verify(struct search *s)
{
char name[BDEVNAME_SIZE];
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
struct closure *cl = &s->cl;
struct bio *check;
struct bio_vec *bv;
int i;
if (!s->unaligned_bvec)
bio_for_each_segment(bv, s->orig_bio, i)
bv->bv_offset = 0, bv->bv_len = PAGE_SIZE;
check = bio_clone(s->orig_bio, GFP_NOIO);
if (!check)
return;
if (bch_bio_alloc_pages(check, GFP_NOIO))
goto out_put;
check->bi_rw = READ_SYNC;
check->bi_private = cl;
check->bi_end_io = data_verify_endio;
closure_bio_submit(check, cl, &dc->disk);
closure_sync(cl);
bio_for_each_segment(bv, s->orig_bio, i) {
void *p1 = kmap(bv->bv_page);
void *p2 = kmap(check->bi_io_vec[i].bv_page);
if (memcmp(p1 + bv->bv_offset,
p2 + bv->bv_offset,
bv->bv_len))
printk(KERN_ERR
"bcache (%s): verify failed at sector %llu\n",
bdevname(dc->bdev, name),
(uint64_t) s->orig_bio->bi_sector);
kunmap(bv->bv_page);
kunmap(check->bi_io_vec[i].bv_page);
}
__bio_for_each_segment(bv, check, i, 0)
__free_page(bv->bv_page);
out_put:
bio_put(check);
}
#endif
#ifdef CONFIG_BCACHE_EDEBUG
unsigned bch_count_data(struct btree *b)
{
unsigned ret = 0;
struct btree_iter iter;
struct bkey *k;
if (!b->level)
for_each_key(b, k, &iter)
ret += KEY_SIZE(k);
return ret;
}
static void vdump_bucket_and_panic(struct btree *b, const char *fmt,
va_list args)
{
unsigned i;
console_lock();
for (i = 0; i <= b->nsets; i++)
dump_bset(b, b->sets[i].data);
vprintk(fmt, args);
console_unlock();
panic("at %s\n", pbtree(b));
}
void bch_check_key_order_msg(struct btree *b, struct bset *i,
const char *fmt, ...)
{
struct bkey *k;
if (!i->keys)
return;
for (k = i->start; bkey_next(k) < end(i); k = bkey_next(k))
if (skipped_backwards(b, k)) {
va_list args;
va_start(args, fmt);
vdump_bucket_and_panic(b, fmt, args);
va_end(args);
}
}
void bch_check_keys(struct btree *b, const char *fmt, ...)
{
va_list args;
struct bkey *k, *p = NULL;
struct btree_iter iter;
if (b->level)
return;
for_each_key(b, k, &iter) {
if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) {
printk(KERN_ERR "Keys out of order:\n");
goto bug;
}
if (bch_ptr_invalid(b, k))
continue;
if (p && bkey_cmp(p, &START_KEY(k)) > 0) {
printk(KERN_ERR "Overlapping keys:\n");
goto bug;
}
p = k;
}
return;
bug:
va_start(args, fmt);
vdump_bucket_and_panic(b, fmt, args);
va_end(args);
}
#endif
#ifdef CONFIG_DEBUG_FS
/* XXX: cache set refcounting */
struct dump_iterator {
char buf[PAGE_SIZE];
size_t bytes;
struct cache_set *c;
struct keybuf keys;
};
static bool dump_pred(struct keybuf *buf, struct bkey *k)
{
return true;
}
static ssize_t bch_dump_read(struct file *file, char __user *buf,
size_t size, loff_t *ppos)
{
struct dump_iterator *i = file->private_data;
ssize_t ret = 0;
while (size) {
struct keybuf_key *w;
unsigned bytes = min(i->bytes, size);
int err = copy_to_user(buf, i->buf, bytes);
if (err)
return err;
ret += bytes;
buf += bytes;
size -= bytes;
i->bytes -= bytes;
memmove(i->buf, i->buf + bytes, i->bytes);
if (i->bytes)
break;
w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY);
if (!w)
break;
i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", pkey(&w->key));
bch_keybuf_del(&i->keys, w);
}
return ret;
}
static int bch_dump_open(struct inode *inode, struct file *file)
{
struct cache_set *c = inode->i_private;
struct dump_iterator *i;
i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
if (!i)
return -ENOMEM;
file->private_data = i;
i->c = c;
bch_keybuf_init(&i->keys, dump_pred);
i->keys.last_scanned = KEY(0, 0, 0);
return 0;
}
static int bch_dump_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
static const struct file_operations cache_set_debug_ops = {
.owner = THIS_MODULE,
.open = bch_dump_open,
.read = bch_dump_read,
.release = bch_dump_release
};
void bch_debug_init_cache_set(struct cache_set *c)
{
if (!IS_ERR_OR_NULL(debug)) {
char name[50];
snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
c->debug = debugfs_create_file(name, 0400, debug, c,
&cache_set_debug_ops);
}
}
#endif
/* Fuzz tester has rotted: */
#if 0
static ssize_t btree_fuzz(struct kobject *k, struct kobj_attribute *a,
const char *buffer, size_t size)
{
void dump(struct btree *b)
{
struct bset *i;
for (i = b->sets[0].data;
index(i, b) < btree_blocks(b) &&
i->seq == b->sets[0].data->seq;
i = ((void *) i) + set_blocks(i, b->c) * block_bytes(b->c))
dump_bset(b, i);
}
struct cache_sb *sb;
struct cache_set *c;
struct btree *all[3], *b, *fill, *orig;
int j;
struct btree_op op;
bch_btree_op_init_stack(&op);
sb = kzalloc(sizeof(struct cache_sb), GFP_KERNEL);
if (!sb)
return -ENOMEM;
sb->bucket_size = 128;
sb->block_size = 4;
c = bch_cache_set_alloc(sb);
if (!c)
return -ENOMEM;
for (j = 0; j < 3; j++) {
BUG_ON(list_empty(&c->btree_cache));
all[j] = list_first_entry(&c->btree_cache, struct btree, list);
list_del_init(&all[j]->list);
all[j]->key = KEY(0, 0, c->sb.bucket_size);
bkey_copy_key(&all[j]->key, &MAX_KEY);
}
b = all[0];
fill = all[1];
orig = all[2];
while (1) {
for (j = 0; j < 3; j++)
all[j]->written = all[j]->nsets = 0;
bch_bset_init_next(b);
while (1) {
struct bset *i = write_block(b);
struct bkey *k = op.keys.top;
unsigned rand;
bkey_init(k);
rand = get_random_int();
op.type = rand & 1
? BTREE_INSERT
: BTREE_REPLACE;
rand >>= 1;
SET_KEY_SIZE(k, bucket_remainder(c, rand));
rand >>= c->bucket_bits;
rand &= 1024 * 512 - 1;
rand += c->sb.bucket_size;
SET_KEY_OFFSET(k, rand);
#if 0
SET_KEY_PTRS(k, 1);
#endif
bch_keylist_push(&op.keys);
bch_btree_insert_keys(b, &op);
if (should_split(b) ||
set_blocks(i, b->c) !=
__set_blocks(i, i->keys + 15, b->c)) {
i->csum = csum_set(i);
memcpy(write_block(fill),
i, set_bytes(i));
b->written += set_blocks(i, b->c);
fill->written = b->written;
if (b->written == btree_blocks(b))
break;
bch_btree_sort_lazy(b);
bch_bset_init_next(b);
}
}
memcpy(orig->sets[0].data,
fill->sets[0].data,
btree_bytes(c));
bch_btree_sort(b);
fill->written = 0;
bch_btree_read_done(&fill->io.cl);
if (b->sets[0].data->keys != fill->sets[0].data->keys ||
memcmp(b->sets[0].data->start,
fill->sets[0].data->start,
b->sets[0].data->keys * sizeof(uint64_t))) {
struct bset *i = b->sets[0].data;
struct bkey *k, *l;
for (k = i->start,
l = fill->sets[0].data->start;
k < end(i);
k = bkey_next(k), l = bkey_next(l))
if (bkey_cmp(k, l) ||
KEY_SIZE(k) != KEY_SIZE(l))
pr_err("key %zi differs: %s != %s",
(uint64_t *) k - i->d,
pkey(k), pkey(l));
for (j = 0; j < 3; j++) {
pr_err("**** Set %i ****", j);
dump(all[j]);
}
panic("\n");
}
pr_info("fuzz complete: %i keys", b->sets[0].data->keys);
}
}
kobj_attribute_write(fuzz, btree_fuzz);
#endif
void bch_debug_exit(void)
{
if (!IS_ERR_OR_NULL(debug))
debugfs_remove_recursive(debug);
}
int __init bch_debug_init(struct kobject *kobj)
{
int ret = 0;
#if 0
ret = sysfs_create_file(kobj, &ksysfs_fuzz.attr);
if (ret)
return ret;
#endif
debug = debugfs_create_dir("bcache", NULL);
return ret;
}

54
drivers/md/bcache/debug.h Normal file
View file

@ -0,0 +1,54 @@
#ifndef _BCACHE_DEBUG_H
#define _BCACHE_DEBUG_H
/* Btree/bkey debug printing */
#define KEYHACK_SIZE 80
struct keyprint_hack {
char s[KEYHACK_SIZE];
};
struct keyprint_hack bch_pkey(const struct bkey *k);
struct keyprint_hack bch_pbtree(const struct btree *b);
#define pkey(k) (&bch_pkey(k).s[0])
#define pbtree(b) (&bch_pbtree(b).s[0])
#ifdef CONFIG_BCACHE_EDEBUG
unsigned bch_count_data(struct btree *);
void bch_check_key_order_msg(struct btree *, struct bset *, const char *, ...);
void bch_check_keys(struct btree *, const char *, ...);
#define bch_check_key_order(b, i) \
bch_check_key_order_msg(b, i, "keys out of order")
#define EBUG_ON(cond) BUG_ON(cond)
#else /* EDEBUG */
#define bch_count_data(b) 0
#define bch_check_key_order(b, i) do {} while (0)
#define bch_check_key_order_msg(b, i, ...) do {} while (0)
#define bch_check_keys(b, ...) do {} while (0)
#define EBUG_ON(cond) do {} while (0)
#endif
#ifdef CONFIG_BCACHE_DEBUG
void bch_btree_verify(struct btree *, struct bset *);
void bch_data_verify(struct search *);
#else /* DEBUG */
static inline void bch_btree_verify(struct btree *b, struct bset *i) {}
static inline void bch_data_verify(struct search *s) {};
#endif
#ifdef CONFIG_DEBUG_FS
void bch_debug_init_cache_set(struct cache_set *);
#else
static inline void bch_debug_init_cache_set(struct cache_set *c) {}
#endif
#endif

397
drivers/md/bcache/io.c Normal file
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@ -0,0 +1,397 @@
/*
* Some low level IO code, and hacks for various block layer limitations
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "bset.h"
#include "debug.h"
static void bch_bi_idx_hack_endio(struct bio *bio, int error)
{
struct bio *p = bio->bi_private;
bio_endio(p, error);
bio_put(bio);
}
static void bch_generic_make_request_hack(struct bio *bio)
{
if (bio->bi_idx) {
struct bio *clone = bio_alloc(GFP_NOIO, bio_segments(bio));
memcpy(clone->bi_io_vec,
bio_iovec(bio),
bio_segments(bio) * sizeof(struct bio_vec));
clone->bi_sector = bio->bi_sector;
clone->bi_bdev = bio->bi_bdev;
clone->bi_rw = bio->bi_rw;
clone->bi_vcnt = bio_segments(bio);
clone->bi_size = bio->bi_size;
clone->bi_private = bio;
clone->bi_end_io = bch_bi_idx_hack_endio;
bio = clone;
}
/*
* Hack, since drivers that clone bios clone up to bi_max_vecs, but our
* bios might have had more than that (before we split them per device
* limitations).
*
* To be taken out once immutable bvec stuff is in.
*/
bio->bi_max_vecs = bio->bi_vcnt;
generic_make_request(bio);
}
/**
* bch_bio_split - split a bio
* @bio: bio to split
* @sectors: number of sectors to split from the front of @bio
* @gfp: gfp mask
* @bs: bio set to allocate from
*
* Allocates and returns a new bio which represents @sectors from the start of
* @bio, and updates @bio to represent the remaining sectors.
*
* If bio_sectors(@bio) was less than or equal to @sectors, returns @bio
* unchanged.
*
* The newly allocated bio will point to @bio's bi_io_vec, if the split was on a
* bvec boundry; it is the caller's responsibility to ensure that @bio is not
* freed before the split.
*
* If bch_bio_split() is running under generic_make_request(), it's not safe to
* allocate more than one bio from the same bio set. Therefore, if it is running
* under generic_make_request() it masks out __GFP_WAIT when doing the
* allocation. The caller must check for failure if there's any possibility of
* it being called from under generic_make_request(); it is then the caller's
* responsibility to retry from a safe context (by e.g. punting to workqueue).
*/
struct bio *bch_bio_split(struct bio *bio, int sectors,
gfp_t gfp, struct bio_set *bs)
{
unsigned idx = bio->bi_idx, vcnt = 0, nbytes = sectors << 9;
struct bio_vec *bv;
struct bio *ret = NULL;
BUG_ON(sectors <= 0);
/*
* If we're being called from underneath generic_make_request() and we
* already allocated any bios from this bio set, we risk deadlock if we
* use the mempool. So instead, we possibly fail and let the caller punt
* to workqueue or somesuch and retry in a safe context.
*/
if (current->bio_list)
gfp &= ~__GFP_WAIT;
if (sectors >= bio_sectors(bio))
return bio;
if (bio->bi_rw & REQ_DISCARD) {
ret = bio_alloc_bioset(gfp, 1, bs);
idx = 0;
goto out;
}
bio_for_each_segment(bv, bio, idx) {
vcnt = idx - bio->bi_idx;
if (!nbytes) {
ret = bio_alloc_bioset(gfp, vcnt, bs);
if (!ret)
return NULL;
memcpy(ret->bi_io_vec, bio_iovec(bio),
sizeof(struct bio_vec) * vcnt);
break;
} else if (nbytes < bv->bv_len) {
ret = bio_alloc_bioset(gfp, ++vcnt, bs);
if (!ret)
return NULL;
memcpy(ret->bi_io_vec, bio_iovec(bio),
sizeof(struct bio_vec) * vcnt);
ret->bi_io_vec[vcnt - 1].bv_len = nbytes;
bv->bv_offset += nbytes;
bv->bv_len -= nbytes;
break;
}
nbytes -= bv->bv_len;
}
out:
ret->bi_bdev = bio->bi_bdev;
ret->bi_sector = bio->bi_sector;
ret->bi_size = sectors << 9;
ret->bi_rw = bio->bi_rw;
ret->bi_vcnt = vcnt;
ret->bi_max_vecs = vcnt;
bio->bi_sector += sectors;
bio->bi_size -= sectors << 9;
bio->bi_idx = idx;
if (bio_integrity(bio)) {
if (bio_integrity_clone(ret, bio, gfp)) {
bio_put(ret);
return NULL;
}
bio_integrity_trim(ret, 0, bio_sectors(ret));
bio_integrity_trim(bio, bio_sectors(ret), bio_sectors(bio));
}
return ret;
}
static unsigned bch_bio_max_sectors(struct bio *bio)
{
unsigned ret = bio_sectors(bio);
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
unsigned max_segments = min_t(unsigned, BIO_MAX_PAGES,
queue_max_segments(q));
struct bio_vec *bv, *end = bio_iovec(bio) +
min_t(int, bio_segments(bio), max_segments);
if (bio->bi_rw & REQ_DISCARD)
return min(ret, q->limits.max_discard_sectors);
if (bio_segments(bio) > max_segments ||
q->merge_bvec_fn) {
ret = 0;
for (bv = bio_iovec(bio); bv < end; bv++) {
struct bvec_merge_data bvm = {
.bi_bdev = bio->bi_bdev,
.bi_sector = bio->bi_sector,
.bi_size = ret << 9,
.bi_rw = bio->bi_rw,
};
if (q->merge_bvec_fn &&
q->merge_bvec_fn(q, &bvm, bv) < (int) bv->bv_len)
break;
ret += bv->bv_len >> 9;
}
}
ret = min(ret, queue_max_sectors(q));
WARN_ON(!ret);
ret = max_t(int, ret, bio_iovec(bio)->bv_len >> 9);
return ret;
}
static void bch_bio_submit_split_done(struct closure *cl)
{
struct bio_split_hook *s = container_of(cl, struct bio_split_hook, cl);
s->bio->bi_end_io = s->bi_end_io;
s->bio->bi_private = s->bi_private;
bio_endio(s->bio, 0);
closure_debug_destroy(&s->cl);
mempool_free(s, s->p->bio_split_hook);
}
static void bch_bio_submit_split_endio(struct bio *bio, int error)
{
struct closure *cl = bio->bi_private;
struct bio_split_hook *s = container_of(cl, struct bio_split_hook, cl);
if (error)
clear_bit(BIO_UPTODATE, &s->bio->bi_flags);
bio_put(bio);
closure_put(cl);
}
static void __bch_bio_submit_split(struct closure *cl)
{
struct bio_split_hook *s = container_of(cl, struct bio_split_hook, cl);
struct bio *bio = s->bio, *n;
do {
n = bch_bio_split(bio, bch_bio_max_sectors(bio),
GFP_NOIO, s->p->bio_split);
if (!n)
continue_at(cl, __bch_bio_submit_split, system_wq);
n->bi_end_io = bch_bio_submit_split_endio;
n->bi_private = cl;
closure_get(cl);
bch_generic_make_request_hack(n);
} while (n != bio);
continue_at(cl, bch_bio_submit_split_done, NULL);
}
void bch_generic_make_request(struct bio *bio, struct bio_split_pool *p)
{
struct bio_split_hook *s;
if (!bio_has_data(bio) && !(bio->bi_rw & REQ_DISCARD))
goto submit;
if (bio_sectors(bio) <= bch_bio_max_sectors(bio))
goto submit;
s = mempool_alloc(p->bio_split_hook, GFP_NOIO);
s->bio = bio;
s->p = p;
s->bi_end_io = bio->bi_end_io;
s->bi_private = bio->bi_private;
bio_get(bio);
closure_call(&s->cl, __bch_bio_submit_split, NULL, NULL);
return;
submit:
bch_generic_make_request_hack(bio);
}
/* Bios with headers */
void bch_bbio_free(struct bio *bio, struct cache_set *c)
{
struct bbio *b = container_of(bio, struct bbio, bio);
mempool_free(b, c->bio_meta);
}
struct bio *bch_bbio_alloc(struct cache_set *c)
{
struct bbio *b = mempool_alloc(c->bio_meta, GFP_NOIO);
struct bio *bio = &b->bio;
bio_init(bio);
bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
bio->bi_max_vecs = bucket_pages(c);
bio->bi_io_vec = bio->bi_inline_vecs;
return bio;
}
void __bch_submit_bbio(struct bio *bio, struct cache_set *c)
{
struct bbio *b = container_of(bio, struct bbio, bio);
bio->bi_sector = PTR_OFFSET(&b->key, 0);
bio->bi_bdev = PTR_CACHE(c, &b->key, 0)->bdev;
b->submit_time_us = local_clock_us();
closure_bio_submit(bio, bio->bi_private, PTR_CACHE(c, &b->key, 0));
}
void bch_submit_bbio(struct bio *bio, struct cache_set *c,
struct bkey *k, unsigned ptr)
{
struct bbio *b = container_of(bio, struct bbio, bio);
bch_bkey_copy_single_ptr(&b->key, k, ptr);
__bch_submit_bbio(bio, c);
}
/* IO errors */
void bch_count_io_errors(struct cache *ca, int error, const char *m)
{
/*
* The halflife of an error is:
* log2(1/2)/log2(127/128) * refresh ~= 88 * refresh
*/
if (ca->set->error_decay) {
unsigned count = atomic_inc_return(&ca->io_count);
while (count > ca->set->error_decay) {
unsigned errors;
unsigned old = count;
unsigned new = count - ca->set->error_decay;
/*
* First we subtract refresh from count; each time we
* succesfully do so, we rescale the errors once:
*/
count = atomic_cmpxchg(&ca->io_count, old, new);
if (count == old) {
count = new;
errors = atomic_read(&ca->io_errors);
do {
old = errors;
new = ((uint64_t) errors * 127) / 128;
errors = atomic_cmpxchg(&ca->io_errors,
old, new);
} while (old != errors);
}
}
}
if (error) {
char buf[BDEVNAME_SIZE];
unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT,
&ca->io_errors);
errors >>= IO_ERROR_SHIFT;
if (errors < ca->set->error_limit)
pr_err("%s: IO error on %s, recovering",
bdevname(ca->bdev, buf), m);
else
bch_cache_set_error(ca->set,
"%s: too many IO errors %s",
bdevname(ca->bdev, buf), m);
}
}
void bch_bbio_count_io_errors(struct cache_set *c, struct bio *bio,
int error, const char *m)
{
struct bbio *b = container_of(bio, struct bbio, bio);
struct cache *ca = PTR_CACHE(c, &b->key, 0);
unsigned threshold = bio->bi_rw & REQ_WRITE
? c->congested_write_threshold_us
: c->congested_read_threshold_us;
if (threshold) {
unsigned t = local_clock_us();
int us = t - b->submit_time_us;
int congested = atomic_read(&c->congested);
if (us > (int) threshold) {
int ms = us / 1024;
c->congested_last_us = t;
ms = min(ms, CONGESTED_MAX + congested);
atomic_sub(ms, &c->congested);
} else if (congested < 0)
atomic_inc(&c->congested);
}
bch_count_io_errors(ca, error, m);
}
void bch_bbio_endio(struct cache_set *c, struct bio *bio,
int error, const char *m)
{
struct closure *cl = bio->bi_private;
bch_bbio_count_io_errors(c, bio, error, m);
bio_put(bio);
closure_put(cl);
}

787
drivers/md/bcache/journal.c Normal file
View file

@ -0,0 +1,787 @@
/*
* bcache journalling code, for btree insertions
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "request.h"
/*
* Journal replay/recovery:
*
* This code is all driven from run_cache_set(); we first read the journal
* entries, do some other stuff, then we mark all the keys in the journal
* entries (same as garbage collection would), then we replay them - reinserting
* them into the cache in precisely the same order as they appear in the
* journal.
*
* We only journal keys that go in leaf nodes, which simplifies things quite a
* bit.
*/
static void journal_read_endio(struct bio *bio, int error)
{
struct closure *cl = bio->bi_private;
closure_put(cl);
}
static int journal_read_bucket(struct cache *ca, struct list_head *list,
struct btree_op *op, unsigned bucket_index)
{
struct journal_device *ja = &ca->journal;
struct bio *bio = &ja->bio;
struct journal_replay *i;
struct jset *j, *data = ca->set->journal.w[0].data;
unsigned len, left, offset = 0;
int ret = 0;
sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]);
pr_debug("reading %llu", (uint64_t) bucket);
while (offset < ca->sb.bucket_size) {
reread: left = ca->sb.bucket_size - offset;
len = min_t(unsigned, left, PAGE_SECTORS * 8);
bio_reset(bio);
bio->bi_sector = bucket + offset;
bio->bi_bdev = ca->bdev;
bio->bi_rw = READ;
bio->bi_size = len << 9;
bio->bi_end_io = journal_read_endio;
bio->bi_private = &op->cl;
bch_bio_map(bio, data);
closure_bio_submit(bio, &op->cl, ca);
closure_sync(&op->cl);
/* This function could be simpler now since we no longer write
* journal entries that overlap bucket boundaries; this means
* the start of a bucket will always have a valid journal entry
* if it has any journal entries at all.
*/
j = data;
while (len) {
struct list_head *where;
size_t blocks, bytes = set_bytes(j);
if (j->magic != jset_magic(ca->set))
return ret;
if (bytes > left << 9)
return ret;
if (bytes > len << 9)
goto reread;
if (j->csum != csum_set(j))
return ret;
blocks = set_blocks(j, ca->set);
while (!list_empty(list)) {
i = list_first_entry(list,
struct journal_replay, list);
if (i->j.seq >= j->last_seq)
break;
list_del(&i->list);
kfree(i);
}
list_for_each_entry_reverse(i, list, list) {
if (j->seq == i->j.seq)
goto next_set;
if (j->seq < i->j.last_seq)
goto next_set;
if (j->seq > i->j.seq) {
where = &i->list;
goto add;
}
}
where = list;
add:
i = kmalloc(offsetof(struct journal_replay, j) +
bytes, GFP_KERNEL);
if (!i)
return -ENOMEM;
memcpy(&i->j, j, bytes);
list_add(&i->list, where);
ret = 1;
ja->seq[bucket_index] = j->seq;
next_set:
offset += blocks * ca->sb.block_size;
len -= blocks * ca->sb.block_size;
j = ((void *) j) + blocks * block_bytes(ca);
}
}
return ret;
}
int bch_journal_read(struct cache_set *c, struct list_head *list,
struct btree_op *op)
{
#define read_bucket(b) \
({ \
int ret = journal_read_bucket(ca, list, op, b); \
__set_bit(b, bitmap); \
if (ret < 0) \
return ret; \
ret; \
})
struct cache *ca;
unsigned iter;
for_each_cache(ca, c, iter) {
struct journal_device *ja = &ca->journal;
unsigned long bitmap[SB_JOURNAL_BUCKETS / BITS_PER_LONG];
unsigned i, l, r, m;
uint64_t seq;
bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
pr_debug("%u journal buckets", ca->sb.njournal_buckets);
/* Read journal buckets ordered by golden ratio hash to quickly
* find a sequence of buckets with valid journal entries
*/
for (i = 0; i < ca->sb.njournal_buckets; i++) {
l = (i * 2654435769U) % ca->sb.njournal_buckets;
if (test_bit(l, bitmap))
break;
if (read_bucket(l))
goto bsearch;
}
/* If that fails, check all the buckets we haven't checked
* already
*/
pr_debug("falling back to linear search");
for (l = 0; l < ca->sb.njournal_buckets; l++) {
if (test_bit(l, bitmap))
continue;
if (read_bucket(l))
goto bsearch;
}
bsearch:
/* Binary search */
m = r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
pr_debug("starting binary search, l %u r %u", l, r);
while (l + 1 < r) {
m = (l + r) >> 1;
if (read_bucket(m))
l = m;
else
r = m;
}
/* Read buckets in reverse order until we stop finding more
* journal entries
*/
pr_debug("finishing up");
l = m;
while (1) {
if (!l--)
l = ca->sb.njournal_buckets - 1;
if (l == m)
break;
if (test_bit(l, bitmap))
continue;
if (!read_bucket(l))
break;
}
seq = 0;
for (i = 0; i < ca->sb.njournal_buckets; i++)
if (ja->seq[i] > seq) {
seq = ja->seq[i];
ja->cur_idx = ja->discard_idx =
ja->last_idx = i;
}
}
c->journal.seq = list_entry(list->prev,
struct journal_replay,
list)->j.seq;
return 0;
#undef read_bucket
}
void bch_journal_mark(struct cache_set *c, struct list_head *list)
{
atomic_t p = { 0 };
struct bkey *k;
struct journal_replay *i;
struct journal *j = &c->journal;
uint64_t last = j->seq;
/*
* journal.pin should never fill up - we never write a journal
* entry when it would fill up. But if for some reason it does, we
* iterate over the list in reverse order so that we can just skip that
* refcount instead of bugging.
*/
list_for_each_entry_reverse(i, list, list) {
BUG_ON(last < i->j.seq);
i->pin = NULL;
while (last-- != i->j.seq)
if (fifo_free(&j->pin) > 1) {
fifo_push_front(&j->pin, p);
atomic_set(&fifo_front(&j->pin), 0);
}
if (fifo_free(&j->pin) > 1) {
fifo_push_front(&j->pin, p);
i->pin = &fifo_front(&j->pin);
atomic_set(i->pin, 1);
}
for (k = i->j.start;
k < end(&i->j);
k = bkey_next(k)) {
unsigned j;
for (j = 0; j < KEY_PTRS(k); j++) {
struct bucket *g = PTR_BUCKET(c, k, j);
atomic_inc(&g->pin);
if (g->prio == BTREE_PRIO &&
!ptr_stale(c, k, j))
g->prio = INITIAL_PRIO;
}
__bch_btree_mark_key(c, 0, k);
}
}
}
int bch_journal_replay(struct cache_set *s, struct list_head *list,
struct btree_op *op)
{
int ret = 0, keys = 0, entries = 0;
struct bkey *k;
struct journal_replay *i =
list_entry(list->prev, struct journal_replay, list);
uint64_t start = i->j.last_seq, end = i->j.seq, n = start;
list_for_each_entry(i, list, list) {
BUG_ON(i->pin && atomic_read(i->pin) != 1);
if (n != i->j.seq)
pr_err(
"journal entries %llu-%llu missing! (replaying %llu-%llu)\n",
n, i->j.seq - 1, start, end);
for (k = i->j.start;
k < end(&i->j);
k = bkey_next(k)) {
pr_debug("%s", pkey(k));
bkey_copy(op->keys.top, k);
bch_keylist_push(&op->keys);
op->journal = i->pin;
atomic_inc(op->journal);
ret = bch_btree_insert(op, s);
if (ret)
goto err;
BUG_ON(!bch_keylist_empty(&op->keys));
keys++;
cond_resched();
}
if (i->pin)
atomic_dec(i->pin);
n = i->j.seq + 1;
entries++;
}
pr_info("journal replay done, %i keys in %i entries, seq %llu",
keys, entries, end);
while (!list_empty(list)) {
i = list_first_entry(list, struct journal_replay, list);
list_del(&i->list);
kfree(i);
}
err:
closure_sync(&op->cl);
return ret;
}
/* Journalling */
static void btree_flush_write(struct cache_set *c)
{
/*
* Try to find the btree node with that references the oldest journal
* entry, best is our current candidate and is locked if non NULL:
*/
struct btree *b, *best = NULL;
unsigned iter;
for_each_cached_btree(b, c, iter) {
if (!down_write_trylock(&b->lock))
continue;
if (!btree_node_dirty(b) ||
!btree_current_write(b)->journal) {
rw_unlock(true, b);
continue;
}
if (!best)
best = b;
else if (journal_pin_cmp(c,
btree_current_write(best),
btree_current_write(b))) {
rw_unlock(true, best);
best = b;
} else
rw_unlock(true, b);
}
if (best)
goto out;
/* We can't find the best btree node, just pick the first */
list_for_each_entry(b, &c->btree_cache, list)
if (!b->level && btree_node_dirty(b)) {
best = b;
rw_lock(true, best, best->level);
goto found;
}
out:
if (!best)
return;
found:
if (btree_node_dirty(best))
bch_btree_write(best, true, NULL);
rw_unlock(true, best);
}
#define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1)
static void journal_discard_endio(struct bio *bio, int error)
{
struct journal_device *ja =
container_of(bio, struct journal_device, discard_bio);
struct cache *ca = container_of(ja, struct cache, journal);
atomic_set(&ja->discard_in_flight, DISCARD_DONE);
closure_wake_up(&ca->set->journal.wait);
closure_put(&ca->set->cl);
}
static void journal_discard_work(struct work_struct *work)
{
struct journal_device *ja =
container_of(work, struct journal_device, discard_work);
submit_bio(0, &ja->discard_bio);
}
static void do_journal_discard(struct cache *ca)
{
struct journal_device *ja = &ca->journal;
struct bio *bio = &ja->discard_bio;
if (!ca->discard) {
ja->discard_idx = ja->last_idx;
return;
}
switch (atomic_read(&ja->discard_in_flight) == DISCARD_IN_FLIGHT) {
case DISCARD_IN_FLIGHT:
return;
case DISCARD_DONE:
ja->discard_idx = (ja->discard_idx + 1) %
ca->sb.njournal_buckets;
atomic_set(&ja->discard_in_flight, DISCARD_READY);
/* fallthrough */
case DISCARD_READY:
if (ja->discard_idx == ja->last_idx)
return;
atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT);
bio_init(bio);
bio->bi_sector = bucket_to_sector(ca->set,
ca->sb.d[ja->discard_idx]);
bio->bi_bdev = ca->bdev;
bio->bi_rw = REQ_WRITE|REQ_DISCARD;
bio->bi_max_vecs = 1;
bio->bi_io_vec = bio->bi_inline_vecs;
bio->bi_size = bucket_bytes(ca);
bio->bi_end_io = journal_discard_endio;
closure_get(&ca->set->cl);
INIT_WORK(&ja->discard_work, journal_discard_work);
schedule_work(&ja->discard_work);
}
}
static void journal_reclaim(struct cache_set *c)
{
struct bkey *k = &c->journal.key;
struct cache *ca;
uint64_t last_seq;
unsigned iter, n = 0;
atomic_t p;
while (!atomic_read(&fifo_front(&c->journal.pin)))
fifo_pop(&c->journal.pin, p);
last_seq = last_seq(&c->journal);
/* Update last_idx */
for_each_cache(ca, c, iter) {
struct journal_device *ja = &ca->journal;
while (ja->last_idx != ja->cur_idx &&
ja->seq[ja->last_idx] < last_seq)
ja->last_idx = (ja->last_idx + 1) %
ca->sb.njournal_buckets;
}
for_each_cache(ca, c, iter)
do_journal_discard(ca);
if (c->journal.blocks_free)
return;
/*
* Allocate:
* XXX: Sort by free journal space
*/
for_each_cache(ca, c, iter) {
struct journal_device *ja = &ca->journal;
unsigned next = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
/* No space available on this device */
if (next == ja->discard_idx)
continue;
ja->cur_idx = next;
k->ptr[n++] = PTR(0,
bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
ca->sb.nr_this_dev);
}
bkey_init(k);
SET_KEY_PTRS(k, n);
if (n)
c->journal.blocks_free = c->sb.bucket_size >> c->block_bits;
if (!journal_full(&c->journal))
__closure_wake_up(&c->journal.wait);
}
void bch_journal_next(struct journal *j)
{
atomic_t p = { 1 };
j->cur = (j->cur == j->w)
? &j->w[1]
: &j->w[0];
/*
* The fifo_push() needs to happen at the same time as j->seq is
* incremented for last_seq() to be calculated correctly
*/
BUG_ON(!fifo_push(&j->pin, p));
atomic_set(&fifo_back(&j->pin), 1);
j->cur->data->seq = ++j->seq;
j->cur->need_write = false;
j->cur->data->keys = 0;
if (fifo_full(&j->pin))
pr_debug("journal_pin full (%zu)", fifo_used(&j->pin));
}
static void journal_write_endio(struct bio *bio, int error)
{
struct journal_write *w = bio->bi_private;
cache_set_err_on(error, w->c, "journal io error");
closure_put(&w->c->journal.io.cl);
}
static void journal_write(struct closure *);
static void journal_write_done(struct closure *cl)
{
struct journal *j = container_of(cl, struct journal, io.cl);
struct cache_set *c = container_of(j, struct cache_set, journal);
struct journal_write *w = (j->cur == j->w)
? &j->w[1]
: &j->w[0];
__closure_wake_up(&w->wait);
if (c->journal_delay_ms)
closure_delay(&j->io, msecs_to_jiffies(c->journal_delay_ms));
continue_at(cl, journal_write, system_wq);
}
static void journal_write_unlocked(struct closure *cl)
__releases(c->journal.lock)
{
struct cache_set *c = container_of(cl, struct cache_set, journal.io.cl);
struct cache *ca;
struct journal_write *w = c->journal.cur;
struct bkey *k = &c->journal.key;
unsigned i, sectors = set_blocks(w->data, c) * c->sb.block_size;
struct bio *bio;
struct bio_list list;
bio_list_init(&list);
if (!w->need_write) {
/*
* XXX: have to unlock closure before we unlock journal lock,
* else we race with bch_journal(). But this way we race
* against cache set unregister. Doh.
*/
set_closure_fn(cl, NULL, NULL);
closure_sub(cl, CLOSURE_RUNNING + 1);
spin_unlock(&c->journal.lock);
return;
} else if (journal_full(&c->journal)) {
journal_reclaim(c);
spin_unlock(&c->journal.lock);
btree_flush_write(c);
continue_at(cl, journal_write, system_wq);
}
c->journal.blocks_free -= set_blocks(w->data, c);
w->data->btree_level = c->root->level;
bkey_copy(&w->data->btree_root, &c->root->key);
bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
for_each_cache(ca, c, i)
w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
w->data->magic = jset_magic(c);
w->data->version = BCACHE_JSET_VERSION;
w->data->last_seq = last_seq(&c->journal);
w->data->csum = csum_set(w->data);
for (i = 0; i < KEY_PTRS(k); i++) {
ca = PTR_CACHE(c, k, i);
bio = &ca->journal.bio;
atomic_long_add(sectors, &ca->meta_sectors_written);
bio_reset(bio);
bio->bi_sector = PTR_OFFSET(k, i);
bio->bi_bdev = ca->bdev;
bio->bi_rw = REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH;
bio->bi_size = sectors << 9;
bio->bi_end_io = journal_write_endio;
bio->bi_private = w;
bch_bio_map(bio, w->data);
trace_bcache_journal_write(bio);
bio_list_add(&list, bio);
SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors);
ca->journal.seq[ca->journal.cur_idx] = w->data->seq;
}
atomic_dec_bug(&fifo_back(&c->journal.pin));
bch_journal_next(&c->journal);
journal_reclaim(c);
spin_unlock(&c->journal.lock);
while ((bio = bio_list_pop(&list)))
closure_bio_submit(bio, cl, c->cache[0]);
continue_at(cl, journal_write_done, NULL);
}
static void journal_write(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, journal.io.cl);
spin_lock(&c->journal.lock);
journal_write_unlocked(cl);
}
static void __journal_try_write(struct cache_set *c, bool noflush)
__releases(c->journal.lock)
{
struct closure *cl = &c->journal.io.cl;
if (!closure_trylock(cl, &c->cl))
spin_unlock(&c->journal.lock);
else if (noflush && journal_full(&c->journal)) {
spin_unlock(&c->journal.lock);
continue_at(cl, journal_write, system_wq);
} else
journal_write_unlocked(cl);
}
#define journal_try_write(c) __journal_try_write(c, false)
void bch_journal_meta(struct cache_set *c, struct closure *cl)
{
struct journal_write *w;
if (CACHE_SYNC(&c->sb)) {
spin_lock(&c->journal.lock);
w = c->journal.cur;
w->need_write = true;
if (cl)
BUG_ON(!closure_wait(&w->wait, cl));
__journal_try_write(c, true);
}
}
/*
* Entry point to the journalling code - bio_insert() and btree_invalidate()
* pass bch_journal() a list of keys to be journalled, and then
* bch_journal() hands those same keys off to btree_insert_async()
*/
void bch_journal(struct closure *cl)
{
struct btree_op *op = container_of(cl, struct btree_op, cl);
struct cache_set *c = op->c;
struct journal_write *w;
size_t b, n = ((uint64_t *) op->keys.top) - op->keys.list;
if (op->type != BTREE_INSERT ||
!CACHE_SYNC(&c->sb))
goto out;
/*
* If we're looping because we errored, might already be waiting on
* another journal write:
*/
while (atomic_read(&cl->parent->remaining) & CLOSURE_WAITING)
closure_sync(cl->parent);
spin_lock(&c->journal.lock);
if (journal_full(&c->journal)) {
/* XXX: tracepoint */
closure_wait(&c->journal.wait, cl);
journal_reclaim(c);
spin_unlock(&c->journal.lock);
btree_flush_write(c);
continue_at(cl, bch_journal, bcache_wq);
}
w = c->journal.cur;
w->need_write = true;
b = __set_blocks(w->data, w->data->keys + n, c);
if (b * c->sb.block_size > PAGE_SECTORS << JSET_BITS ||
b > c->journal.blocks_free) {
/* XXX: If we were inserting so many keys that they won't fit in
* an _empty_ journal write, we'll deadlock. For now, handle
* this in bch_keylist_realloc() - but something to think about.
*/
BUG_ON(!w->data->keys);
/* XXX: tracepoint */
BUG_ON(!closure_wait(&w->wait, cl));
closure_flush(&c->journal.io);
journal_try_write(c);
continue_at(cl, bch_journal, bcache_wq);
}
memcpy(end(w->data), op->keys.list, n * sizeof(uint64_t));
w->data->keys += n;
op->journal = &fifo_back(&c->journal.pin);
atomic_inc(op->journal);
if (op->flush_journal) {
closure_flush(&c->journal.io);
closure_wait(&w->wait, cl->parent);
}
journal_try_write(c);
out:
bch_btree_insert_async(cl);
}
void bch_journal_free(struct cache_set *c)
{
free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
free_fifo(&c->journal.pin);
}
int bch_journal_alloc(struct cache_set *c)
{
struct journal *j = &c->journal;
closure_init_unlocked(&j->io);
spin_lock_init(&j->lock);
c->journal_delay_ms = 100;
j->w[0].c = c;
j->w[1].c = c;
if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
!(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)) ||
!(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)))
return -ENOMEM;
return 0;
}

215
drivers/md/bcache/journal.h Normal file
View file

@ -0,0 +1,215 @@
#ifndef _BCACHE_JOURNAL_H
#define _BCACHE_JOURNAL_H
/*
* THE JOURNAL:
*
* The journal is treated as a circular buffer of buckets - a journal entry
* never spans two buckets. This means (not implemented yet) we can resize the
* journal at runtime, and will be needed for bcache on raw flash support.
*
* Journal entries contain a list of keys, ordered by the time they were
* inserted; thus journal replay just has to reinsert the keys.
*
* We also keep some things in the journal header that are logically part of the
* superblock - all the things that are frequently updated. This is for future
* bcache on raw flash support; the superblock (which will become another
* journal) can't be moved or wear leveled, so it contains just enough
* information to find the main journal, and the superblock only has to be
* rewritten when we want to move/wear level the main journal.
*
* Currently, we don't journal BTREE_REPLACE operations - this will hopefully be
* fixed eventually. This isn't a bug - BTREE_REPLACE is used for insertions
* from cache misses, which don't have to be journaled, and for writeback and
* moving gc we work around it by flushing the btree to disk before updating the
* gc information. But it is a potential issue with incremental garbage
* collection, and it's fragile.
*
* OPEN JOURNAL ENTRIES:
*
* Each journal entry contains, in the header, the sequence number of the last
* journal entry still open - i.e. that has keys that haven't been flushed to
* disk in the btree.
*
* We track this by maintaining a refcount for every open journal entry, in a
* fifo; each entry in the fifo corresponds to a particular journal
* entry/sequence number. When the refcount at the tail of the fifo goes to
* zero, we pop it off - thus, the size of the fifo tells us the number of open
* journal entries
*
* We take a refcount on a journal entry when we add some keys to a journal
* entry that we're going to insert (held by struct btree_op), and then when we
* insert those keys into the btree the btree write we're setting up takes a
* copy of that refcount (held by struct btree_write). That refcount is dropped
* when the btree write completes.
*
* A struct btree_write can only hold a refcount on a single journal entry, but
* might contain keys for many journal entries - we handle this by making sure
* it always has a refcount on the _oldest_ journal entry of all the journal
* entries it has keys for.
*
* JOURNAL RECLAIM:
*
* As mentioned previously, our fifo of refcounts tells us the number of open
* journal entries; from that and the current journal sequence number we compute
* last_seq - the oldest journal entry we still need. We write last_seq in each
* journal entry, and we also have to keep track of where it exists on disk so
* we don't overwrite it when we loop around the journal.
*
* To do that we track, for each journal bucket, the sequence number of the
* newest journal entry it contains - if we don't need that journal entry we
* don't need anything in that bucket anymore. From that we track the last
* journal bucket we still need; all this is tracked in struct journal_device
* and updated by journal_reclaim().
*
* JOURNAL FILLING UP:
*
* There are two ways the journal could fill up; either we could run out of
* space to write to, or we could have too many open journal entries and run out
* of room in the fifo of refcounts. Since those refcounts are decremented
* without any locking we can't safely resize that fifo, so we handle it the
* same way.
*
* If the journal fills up, we start flushing dirty btree nodes until we can
* allocate space for a journal write again - preferentially flushing btree
* nodes that are pinning the oldest journal entries first.
*/
#define BCACHE_JSET_VERSION_UUIDv1 1
/* Always latest UUID format */
#define BCACHE_JSET_VERSION_UUID 1
#define BCACHE_JSET_VERSION 1
/*
* On disk format for a journal entry:
* seq is monotonically increasing; every journal entry has its own unique
* sequence number.
*
* last_seq is the oldest journal entry that still has keys the btree hasn't
* flushed to disk yet.
*
* version is for on disk format changes.
*/
struct jset {
uint64_t csum;
uint64_t magic;
uint64_t seq;
uint32_t version;
uint32_t keys;
uint64_t last_seq;
BKEY_PADDED(uuid_bucket);
BKEY_PADDED(btree_root);
uint16_t btree_level;
uint16_t pad[3];
uint64_t prio_bucket[MAX_CACHES_PER_SET];
union {
struct bkey start[0];
uint64_t d[0];
};
};
/*
* Only used for holding the journal entries we read in btree_journal_read()
* during cache_registration
*/
struct journal_replay {
struct list_head list;
atomic_t *pin;
struct jset j;
};
/*
* We put two of these in struct journal; we used them for writes to the
* journal that are being staged or in flight.
*/
struct journal_write {
struct jset *data;
#define JSET_BITS 3
struct cache_set *c;
struct closure_waitlist wait;
bool need_write;
};
/* Embedded in struct cache_set */
struct journal {
spinlock_t lock;
/* used when waiting because the journal was full */
struct closure_waitlist wait;
struct closure_with_timer io;
/* Number of blocks free in the bucket(s) we're currently writing to */
unsigned blocks_free;
uint64_t seq;
DECLARE_FIFO(atomic_t, pin);
BKEY_PADDED(key);
struct journal_write w[2], *cur;
};
/*
* Embedded in struct cache. First three fields refer to the array of journal
* buckets, in cache_sb.
*/
struct journal_device {
/*
* For each journal bucket, contains the max sequence number of the
* journal writes it contains - so we know when a bucket can be reused.
*/
uint64_t seq[SB_JOURNAL_BUCKETS];
/* Journal bucket we're currently writing to */
unsigned cur_idx;
/* Last journal bucket that still contains an open journal entry */
unsigned last_idx;
/* Next journal bucket to be discarded */
unsigned discard_idx;
#define DISCARD_READY 0
#define DISCARD_IN_FLIGHT 1
#define DISCARD_DONE 2
/* 1 - discard in flight, -1 - discard completed */
atomic_t discard_in_flight;
struct work_struct discard_work;
struct bio discard_bio;
struct bio_vec discard_bv;
/* Bio for journal reads/writes to this device */
struct bio bio;
struct bio_vec bv[8];
};
#define journal_pin_cmp(c, l, r) \
(fifo_idx(&(c)->journal.pin, (l)->journal) > \
fifo_idx(&(c)->journal.pin, (r)->journal))
#define JOURNAL_PIN 20000
#define journal_full(j) \
(!(j)->blocks_free || fifo_free(&(j)->pin) <= 1)
struct closure;
struct cache_set;
struct btree_op;
void bch_journal(struct closure *);
void bch_journal_next(struct journal *);
void bch_journal_mark(struct cache_set *, struct list_head *);
void bch_journal_meta(struct cache_set *, struct closure *);
int bch_journal_read(struct cache_set *, struct list_head *,
struct btree_op *);
int bch_journal_replay(struct cache_set *, struct list_head *,
struct btree_op *);
void bch_journal_free(struct cache_set *);
int bch_journal_alloc(struct cache_set *);
#endif /* _BCACHE_JOURNAL_H */

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/*
* Moving/copying garbage collector
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "request.h"
struct moving_io {
struct keybuf_key *w;
struct search s;
struct bbio bio;
};
static bool moving_pred(struct keybuf *buf, struct bkey *k)
{
struct cache_set *c = container_of(buf, struct cache_set,
moving_gc_keys);
unsigned i;
for (i = 0; i < KEY_PTRS(k); i++) {
struct cache *ca = PTR_CACHE(c, k, i);
struct bucket *g = PTR_BUCKET(c, k, i);
if (GC_SECTORS_USED(g) < ca->gc_move_threshold)
return true;
}
return false;
}
/* Moving GC - IO loop */
static void moving_io_destructor(struct closure *cl)
{
struct moving_io *io = container_of(cl, struct moving_io, s.cl);
kfree(io);
}
static void write_moving_finish(struct closure *cl)
{
struct moving_io *io = container_of(cl, struct moving_io, s.cl);
struct bio *bio = &io->bio.bio;
struct bio_vec *bv = bio_iovec_idx(bio, bio->bi_vcnt);
while (bv-- != bio->bi_io_vec)
__free_page(bv->bv_page);
pr_debug("%s %s", io->s.op.insert_collision
? "collision moving" : "moved",
pkey(&io->w->key));
bch_keybuf_del(&io->s.op.c->moving_gc_keys, io->w);
atomic_dec_bug(&io->s.op.c->in_flight);
closure_wake_up(&io->s.op.c->moving_gc_wait);
closure_return_with_destructor(cl, moving_io_destructor);
}
static void read_moving_endio(struct bio *bio, int error)
{
struct moving_io *io = container_of(bio->bi_private,
struct moving_io, s.cl);
if (error)
io->s.error = error;
bch_bbio_endio(io->s.op.c, bio, error, "reading data to move");
}
static void moving_init(struct moving_io *io)
{
struct bio *bio = &io->bio.bio;
bio_init(bio);
bio_get(bio);
bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
bio->bi_size = KEY_SIZE(&io->w->key) << 9;
bio->bi_max_vecs = DIV_ROUND_UP(KEY_SIZE(&io->w->key),
PAGE_SECTORS);
bio->bi_private = &io->s.cl;
bio->bi_io_vec = bio->bi_inline_vecs;
bch_bio_map(bio, NULL);
}
static void write_moving(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct moving_io *io = container_of(s, struct moving_io, s);
if (!s->error) {
trace_bcache_write_moving(&io->bio.bio);
moving_init(io);
io->bio.bio.bi_sector = KEY_START(&io->w->key);
s->op.lock = -1;
s->op.write_prio = 1;
s->op.cache_bio = &io->bio.bio;
s->writeback = KEY_DIRTY(&io->w->key);
s->op.csum = KEY_CSUM(&io->w->key);
s->op.type = BTREE_REPLACE;
bkey_copy(&s->op.replace, &io->w->key);
closure_init(&s->op.cl, cl);
bch_insert_data(&s->op.cl);
}
continue_at(cl, write_moving_finish, NULL);
}
static void read_moving_submit(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct moving_io *io = container_of(s, struct moving_io, s);
struct bio *bio = &io->bio.bio;
trace_bcache_read_moving(bio);
bch_submit_bbio(bio, s->op.c, &io->w->key, 0);
continue_at(cl, write_moving, bch_gc_wq);
}
static void read_moving(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, moving_gc);
struct keybuf_key *w;
struct moving_io *io;
struct bio *bio;
/* XXX: if we error, background writeback could stall indefinitely */
while (!test_bit(CACHE_SET_STOPPING, &c->flags)) {
w = bch_keybuf_next_rescan(c, &c->moving_gc_keys, &MAX_KEY);
if (!w)
break;
io = kzalloc(sizeof(struct moving_io) + sizeof(struct bio_vec)
* DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS),
GFP_KERNEL);
if (!io)
goto err;
w->private = io;
io->w = w;
io->s.op.inode = KEY_INODE(&w->key);
io->s.op.c = c;
moving_init(io);
bio = &io->bio.bio;
bio->bi_rw = READ;
bio->bi_end_io = read_moving_endio;
if (bch_bio_alloc_pages(bio, GFP_KERNEL))
goto err;
pr_debug("%s", pkey(&w->key));
closure_call(&io->s.cl, read_moving_submit, NULL, &c->gc.cl);
if (atomic_inc_return(&c->in_flight) >= 64) {
closure_wait_event(&c->moving_gc_wait, cl,
atomic_read(&c->in_flight) < 64);
continue_at(cl, read_moving, bch_gc_wq);
}
}
if (0) {
err: if (!IS_ERR_OR_NULL(w->private))
kfree(w->private);
bch_keybuf_del(&c->moving_gc_keys, w);
}
closure_return(cl);
}
static bool bucket_cmp(struct bucket *l, struct bucket *r)
{
return GC_SECTORS_USED(l) < GC_SECTORS_USED(r);
}
static unsigned bucket_heap_top(struct cache *ca)
{
return GC_SECTORS_USED(heap_peek(&ca->heap));
}
void bch_moving_gc(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, gc.cl);
struct cache *ca;
struct bucket *b;
unsigned i;
if (!c->copy_gc_enabled)
closure_return(cl);
mutex_lock(&c->bucket_lock);
for_each_cache(ca, c, i) {
unsigned sectors_to_move = 0;
unsigned reserve_sectors = ca->sb.bucket_size *
min(fifo_used(&ca->free), ca->free.size / 2);
ca->heap.used = 0;
for_each_bucket(b, ca) {
if (!GC_SECTORS_USED(b))
continue;
if (!heap_full(&ca->heap)) {
sectors_to_move += GC_SECTORS_USED(b);
heap_add(&ca->heap, b, bucket_cmp);
} else if (bucket_cmp(b, heap_peek(&ca->heap))) {
sectors_to_move -= bucket_heap_top(ca);
sectors_to_move += GC_SECTORS_USED(b);
ca->heap.data[0] = b;
heap_sift(&ca->heap, 0, bucket_cmp);
}
}
while (sectors_to_move > reserve_sectors) {
heap_pop(&ca->heap, b, bucket_cmp);
sectors_to_move -= GC_SECTORS_USED(b);
}
ca->gc_move_threshold = bucket_heap_top(ca);
pr_debug("threshold %u", ca->gc_move_threshold);
}
mutex_unlock(&c->bucket_lock);
c->moving_gc_keys.last_scanned = ZERO_KEY;
closure_init(&c->moving_gc, cl);
read_moving(&c->moving_gc);
closure_return(cl);
}
void bch_moving_init_cache_set(struct cache_set *c)
{
bch_keybuf_init(&c->moving_gc_keys, moving_pred);
}

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#ifndef _BCACHE_REQUEST_H_
#define _BCACHE_REQUEST_H_
#include <linux/cgroup.h>
struct search {
/* Stack frame for bio_complete */
struct closure cl;
struct bcache_device *d;
struct task_struct *task;
struct bbio bio;
struct bio *orig_bio;
struct bio *cache_miss;
unsigned cache_bio_sectors;
unsigned recoverable:1;
unsigned unaligned_bvec:1;
unsigned write:1;
unsigned writeback:1;
/* IO error returned to s->bio */
short error;
unsigned long start_time;
/* Anything past op->keys won't get zeroed in do_bio_hook */
struct btree_op op;
};
void bch_cache_read_endio(struct bio *, int);
int bch_get_congested(struct cache_set *);
void bch_insert_data(struct closure *cl);
void bch_btree_insert_async(struct closure *);
void bch_cache_read_endio(struct bio *, int);
void bch_open_buckets_free(struct cache_set *);
int bch_open_buckets_alloc(struct cache_set *);
void bch_cached_dev_request_init(struct cached_dev *dc);
void bch_flash_dev_request_init(struct bcache_device *d);
extern struct kmem_cache *bch_search_cache, *bch_passthrough_cache;
struct bch_cgroup {
#ifdef CONFIG_CGROUP_BCACHE
struct cgroup_subsys_state css;
#endif
/*
* We subtract one from the index into bch_cache_modes[], so that
* default == -1; this makes it so the rest match up with d->cache_mode,
* and we use d->cache_mode if cgrp->cache_mode < 0
*/
short cache_mode;
bool verify;
struct cache_stat_collector stats;
};
struct bch_cgroup *bch_bio_to_cgroup(struct bio *bio);
#endif /* _BCACHE_REQUEST_H_ */

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/*
* bcache stats code
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "stats.h"
#include "btree.h"
#include "request.h"
#include "sysfs.h"
/*
* We keep absolute totals of various statistics, and addionally a set of three
* rolling averages.
*
* Every so often, a timer goes off and rescales the rolling averages.
* accounting_rescale[] is how many times the timer has to go off before we
* rescale each set of numbers; that gets us half lives of 5 minutes, one hour,
* and one day.
*
* accounting_delay is how often the timer goes off - 22 times in 5 minutes,
* and accounting_weight is what we use to rescale:
*
* pow(31 / 32, 22) ~= 1/2
*
* So that we don't have to increment each set of numbers every time we (say)
* get a cache hit, we increment a single atomic_t in acc->collector, and when
* the rescale function runs it resets the atomic counter to 0 and adds its
* old value to each of the exported numbers.
*
* To reduce rounding error, the numbers in struct cache_stats are all
* stored left shifted by 16, and scaled back in the sysfs show() function.
*/
static const unsigned DAY_RESCALE = 288;
static const unsigned HOUR_RESCALE = 12;
static const unsigned FIVE_MINUTE_RESCALE = 1;
static const unsigned accounting_delay = (HZ * 300) / 22;
static const unsigned accounting_weight = 32;
/* sysfs reading/writing */
read_attribute(cache_hits);
read_attribute(cache_misses);
read_attribute(cache_bypass_hits);
read_attribute(cache_bypass_misses);
read_attribute(cache_hit_ratio);
read_attribute(cache_readaheads);
read_attribute(cache_miss_collisions);
read_attribute(bypassed);
SHOW(bch_stats)
{
struct cache_stats *s =
container_of(kobj, struct cache_stats, kobj);
#define var(stat) (s->stat >> 16)
var_print(cache_hits);
var_print(cache_misses);
var_print(cache_bypass_hits);
var_print(cache_bypass_misses);
sysfs_print(cache_hit_ratio,
DIV_SAFE(var(cache_hits) * 100,
var(cache_hits) + var(cache_misses)));
var_print(cache_readaheads);
var_print(cache_miss_collisions);
sysfs_hprint(bypassed, var(sectors_bypassed) << 9);
#undef var
return 0;
}
STORE(bch_stats)
{
return size;
}
static void bch_stats_release(struct kobject *k)
{
}
static struct attribute *bch_stats_files[] = {
&sysfs_cache_hits,
&sysfs_cache_misses,
&sysfs_cache_bypass_hits,
&sysfs_cache_bypass_misses,
&sysfs_cache_hit_ratio,
&sysfs_cache_readaheads,
&sysfs_cache_miss_collisions,
&sysfs_bypassed,
NULL
};
static KTYPE(bch_stats);
static void scale_accounting(unsigned long data);
void bch_cache_accounting_init(struct cache_accounting *acc,
struct closure *parent)
{
kobject_init(&acc->total.kobj, &bch_stats_ktype);
kobject_init(&acc->five_minute.kobj, &bch_stats_ktype);
kobject_init(&acc->hour.kobj, &bch_stats_ktype);
kobject_init(&acc->day.kobj, &bch_stats_ktype);
closure_init(&acc->cl, parent);
init_timer(&acc->timer);
acc->timer.expires = jiffies + accounting_delay;
acc->timer.data = (unsigned long) acc;
acc->timer.function = scale_accounting;
add_timer(&acc->timer);
}
int bch_cache_accounting_add_kobjs(struct cache_accounting *acc,
struct kobject *parent)
{
int ret = kobject_add(&acc->total.kobj, parent,
"stats_total");
ret = ret ?: kobject_add(&acc->five_minute.kobj, parent,
"stats_five_minute");
ret = ret ?: kobject_add(&acc->hour.kobj, parent,
"stats_hour");
ret = ret ?: kobject_add(&acc->day.kobj, parent,
"stats_day");
return ret;
}
void bch_cache_accounting_clear(struct cache_accounting *acc)
{
memset(&acc->total.cache_hits,
0,
sizeof(unsigned long) * 7);
}
void bch_cache_accounting_destroy(struct cache_accounting *acc)
{
kobject_put(&acc->total.kobj);
kobject_put(&acc->five_minute.kobj);
kobject_put(&acc->hour.kobj);
kobject_put(&acc->day.kobj);
atomic_set(&acc->closing, 1);
if (del_timer_sync(&acc->timer))
closure_return(&acc->cl);
}
/* EWMA scaling */
static void scale_stat(unsigned long *stat)
{
*stat = ewma_add(*stat, 0, accounting_weight, 0);
}
static void scale_stats(struct cache_stats *stats, unsigned long rescale_at)
{
if (++stats->rescale == rescale_at) {
stats->rescale = 0;
scale_stat(&stats->cache_hits);
scale_stat(&stats->cache_misses);
scale_stat(&stats->cache_bypass_hits);
scale_stat(&stats->cache_bypass_misses);
scale_stat(&stats->cache_readaheads);
scale_stat(&stats->cache_miss_collisions);
scale_stat(&stats->sectors_bypassed);
}
}
static void scale_accounting(unsigned long data)
{
struct cache_accounting *acc = (struct cache_accounting *) data;
#define move_stat(name) do { \
unsigned t = atomic_xchg(&acc->collector.name, 0); \
t <<= 16; \
acc->five_minute.name += t; \
acc->hour.name += t; \
acc->day.name += t; \
acc->total.name += t; \
} while (0)
move_stat(cache_hits);
move_stat(cache_misses);
move_stat(cache_bypass_hits);
move_stat(cache_bypass_misses);
move_stat(cache_readaheads);
move_stat(cache_miss_collisions);
move_stat(sectors_bypassed);
scale_stats(&acc->total, 0);
scale_stats(&acc->day, DAY_RESCALE);
scale_stats(&acc->hour, HOUR_RESCALE);
scale_stats(&acc->five_minute, FIVE_MINUTE_RESCALE);
acc->timer.expires += accounting_delay;
if (!atomic_read(&acc->closing))
add_timer(&acc->timer);
else
closure_return(&acc->cl);
}
static void mark_cache_stats(struct cache_stat_collector *stats,
bool hit, bool bypass)
{
if (!bypass)
if (hit)
atomic_inc(&stats->cache_hits);
else
atomic_inc(&stats->cache_misses);
else
if (hit)
atomic_inc(&stats->cache_bypass_hits);
else
atomic_inc(&stats->cache_bypass_misses);
}
void bch_mark_cache_accounting(struct search *s, bool hit, bool bypass)
{
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
mark_cache_stats(&dc->accounting.collector, hit, bypass);
mark_cache_stats(&s->op.c->accounting.collector, hit, bypass);
#ifdef CONFIG_CGROUP_BCACHE
mark_cache_stats(&(bch_bio_to_cgroup(s->orig_bio)->stats), hit, bypass);
#endif
}
void bch_mark_cache_readahead(struct search *s)
{
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
atomic_inc(&dc->accounting.collector.cache_readaheads);
atomic_inc(&s->op.c->accounting.collector.cache_readaheads);
}
void bch_mark_cache_miss_collision(struct search *s)
{
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
atomic_inc(&dc->accounting.collector.cache_miss_collisions);
atomic_inc(&s->op.c->accounting.collector.cache_miss_collisions);
}
void bch_mark_sectors_bypassed(struct search *s, int sectors)
{
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
atomic_add(sectors, &dc->accounting.collector.sectors_bypassed);
atomic_add(sectors, &s->op.c->accounting.collector.sectors_bypassed);
}

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#ifndef _BCACHE_STATS_H_
#define _BCACHE_STATS_H_
struct cache_stat_collector {
atomic_t cache_hits;
atomic_t cache_misses;
atomic_t cache_bypass_hits;
atomic_t cache_bypass_misses;
atomic_t cache_readaheads;
atomic_t cache_miss_collisions;
atomic_t sectors_bypassed;
};
struct cache_stats {
struct kobject kobj;
unsigned long cache_hits;
unsigned long cache_misses;
unsigned long cache_bypass_hits;
unsigned long cache_bypass_misses;
unsigned long cache_readaheads;
unsigned long cache_miss_collisions;
unsigned long sectors_bypassed;
unsigned rescale;
};
struct cache_accounting {
struct closure cl;
struct timer_list timer;
atomic_t closing;
struct cache_stat_collector collector;
struct cache_stats total;
struct cache_stats five_minute;
struct cache_stats hour;
struct cache_stats day;
};
struct search;
void bch_cache_accounting_init(struct cache_accounting *acc,
struct closure *parent);
int bch_cache_accounting_add_kobjs(struct cache_accounting *acc,
struct kobject *parent);
void bch_cache_accounting_clear(struct cache_accounting *acc);
void bch_cache_accounting_destroy(struct cache_accounting *acc);
void bch_mark_cache_accounting(struct search *s, bool hit, bool bypass);
void bch_mark_cache_readahead(struct search *s);
void bch_mark_cache_miss_collision(struct search *s);
void bch_mark_sectors_bypassed(struct search *s, int sectors);
#endif /* _BCACHE_STATS_H_ */

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/*
* bcache sysfs interfaces
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "sysfs.h"
#include "btree.h"
#include "request.h"
#include <linux/sort.h>
static const char * const cache_replacement_policies[] = {
"lru",
"fifo",
"random",
NULL
};
write_attribute(attach);
write_attribute(detach);
write_attribute(unregister);
write_attribute(stop);
write_attribute(clear_stats);
write_attribute(trigger_gc);
write_attribute(prune_cache);
write_attribute(flash_vol_create);
read_attribute(bucket_size);
read_attribute(block_size);
read_attribute(nbuckets);
read_attribute(tree_depth);
read_attribute(root_usage_percent);
read_attribute(priority_stats);
read_attribute(btree_cache_size);
read_attribute(btree_cache_max_chain);
read_attribute(cache_available_percent);
read_attribute(written);
read_attribute(btree_written);
read_attribute(metadata_written);
read_attribute(active_journal_entries);
sysfs_time_stats_attribute(btree_gc, sec, ms);
sysfs_time_stats_attribute(btree_split, sec, us);
sysfs_time_stats_attribute(btree_sort, ms, us);
sysfs_time_stats_attribute(btree_read, ms, us);
sysfs_time_stats_attribute(try_harder, ms, us);
read_attribute(btree_nodes);
read_attribute(btree_used_percent);
read_attribute(average_key_size);
read_attribute(dirty_data);
read_attribute(bset_tree_stats);
read_attribute(state);
read_attribute(cache_read_races);
read_attribute(writeback_keys_done);
read_attribute(writeback_keys_failed);
read_attribute(io_errors);
read_attribute(congested);
rw_attribute(congested_read_threshold_us);
rw_attribute(congested_write_threshold_us);
rw_attribute(sequential_cutoff);
rw_attribute(sequential_merge);
rw_attribute(data_csum);
rw_attribute(cache_mode);
rw_attribute(writeback_metadata);
rw_attribute(writeback_running);
rw_attribute(writeback_percent);
rw_attribute(writeback_delay);
rw_attribute(writeback_rate);
rw_attribute(writeback_rate_update_seconds);
rw_attribute(writeback_rate_d_term);
rw_attribute(writeback_rate_p_term_inverse);
rw_attribute(writeback_rate_d_smooth);
read_attribute(writeback_rate_debug);
rw_attribute(synchronous);
rw_attribute(journal_delay_ms);
rw_attribute(discard);
rw_attribute(running);
rw_attribute(label);
rw_attribute(readahead);
rw_attribute(io_error_limit);
rw_attribute(io_error_halflife);
rw_attribute(verify);
rw_attribute(key_merging_disabled);
rw_attribute(gc_always_rewrite);
rw_attribute(freelist_percent);
rw_attribute(cache_replacement_policy);
rw_attribute(btree_shrinker_disabled);
rw_attribute(copy_gc_enabled);
rw_attribute(size);
SHOW(__bch_cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
#define var(stat) (dc->stat)
if (attr == &sysfs_cache_mode)
return bch_snprint_string_list(buf, PAGE_SIZE,
bch_cache_modes + 1,
BDEV_CACHE_MODE(&dc->sb));
sysfs_printf(data_csum, "%i", dc->disk.data_csum);
var_printf(verify, "%i");
var_printf(writeback_metadata, "%i");
var_printf(writeback_running, "%i");
var_print(writeback_delay);
var_print(writeback_percent);
sysfs_print(writeback_rate, dc->writeback_rate.rate);
var_print(writeback_rate_update_seconds);
var_print(writeback_rate_d_term);
var_print(writeback_rate_p_term_inverse);
var_print(writeback_rate_d_smooth);
if (attr == &sysfs_writeback_rate_debug) {
char dirty[20];
char derivative[20];
char target[20];
bch_hprint(dirty,
atomic_long_read(&dc->disk.sectors_dirty) << 9);
bch_hprint(derivative, dc->writeback_rate_derivative << 9);
bch_hprint(target, dc->writeback_rate_target << 9);
return sprintf(buf,
"rate:\t\t%u\n"
"change:\t\t%i\n"
"dirty:\t\t%s\n"
"derivative:\t%s\n"
"target:\t\t%s\n",
dc->writeback_rate.rate,
dc->writeback_rate_change,
dirty, derivative, target);
}
sysfs_hprint(dirty_data,
atomic_long_read(&dc->disk.sectors_dirty) << 9);
var_printf(sequential_merge, "%i");
var_hprint(sequential_cutoff);
var_hprint(readahead);
sysfs_print(running, atomic_read(&dc->running));
sysfs_print(state, states[BDEV_STATE(&dc->sb)]);
if (attr == &sysfs_label) {
memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
buf[SB_LABEL_SIZE + 1] = '\0';
strcat(buf, "\n");
return strlen(buf);
}
#undef var
return 0;
}
SHOW_LOCKED(bch_cached_dev)
STORE(__cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
unsigned v = size;
struct cache_set *c;
#define d_strtoul(var) sysfs_strtoul(var, dc->var)
#define d_strtoi_h(var) sysfs_hatoi(var, dc->var)
sysfs_strtoul(data_csum, dc->disk.data_csum);
d_strtoul(verify);
d_strtoul(writeback_metadata);
d_strtoul(writeback_running);
d_strtoul(writeback_delay);
sysfs_strtoul_clamp(writeback_rate,
dc->writeback_rate.rate, 1, 1000000);
sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
d_strtoul(writeback_rate_update_seconds);
d_strtoul(writeback_rate_d_term);
d_strtoul(writeback_rate_p_term_inverse);
sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
dc->writeback_rate_p_term_inverse, 1, INT_MAX);
d_strtoul(writeback_rate_d_smooth);
d_strtoul(sequential_merge);
d_strtoi_h(sequential_cutoff);
d_strtoi_h(readahead);
if (attr == &sysfs_clear_stats)
bch_cache_accounting_clear(&dc->accounting);
if (attr == &sysfs_running &&
strtoul_or_return(buf))
bch_cached_dev_run(dc);
if (attr == &sysfs_cache_mode) {
ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1);
if (v < 0)
return v;
if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) {
SET_BDEV_CACHE_MODE(&dc->sb, v);
bch_write_bdev_super(dc, NULL);
}
}
if (attr == &sysfs_label) {
memcpy(dc->sb.label, buf, SB_LABEL_SIZE);
bch_write_bdev_super(dc, NULL);
if (dc->disk.c) {
memcpy(dc->disk.c->uuids[dc->disk.id].label,
buf, SB_LABEL_SIZE);
bch_uuid_write(dc->disk.c);
}
}
if (attr == &sysfs_attach) {
if (bch_parse_uuid(buf, dc->sb.set_uuid) < 16)
return -EINVAL;
list_for_each_entry(c, &bch_cache_sets, list) {
v = bch_cached_dev_attach(dc, c);
if (!v)
return size;
}
pr_err("Can't attach %s: cache set not found", buf);
size = v;
}
if (attr == &sysfs_detach && dc->disk.c)
bch_cached_dev_detach(dc);
if (attr == &sysfs_stop)
bcache_device_stop(&dc->disk);
return size;
}
STORE(bch_cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
mutex_lock(&bch_register_lock);
size = __cached_dev_store(kobj, attr, buf, size);
if (attr == &sysfs_writeback_running)
bch_writeback_queue(dc);
if (attr == &sysfs_writeback_percent)
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
mutex_unlock(&bch_register_lock);
return size;
}
static struct attribute *bch_cached_dev_files[] = {
&sysfs_attach,
&sysfs_detach,
&sysfs_stop,
#if 0
&sysfs_data_csum,
#endif
&sysfs_cache_mode,
&sysfs_writeback_metadata,
&sysfs_writeback_running,
&sysfs_writeback_delay,
&sysfs_writeback_percent,
&sysfs_writeback_rate,
&sysfs_writeback_rate_update_seconds,
&sysfs_writeback_rate_d_term,
&sysfs_writeback_rate_p_term_inverse,
&sysfs_writeback_rate_d_smooth,
&sysfs_writeback_rate_debug,
&sysfs_dirty_data,
&sysfs_sequential_cutoff,
&sysfs_sequential_merge,
&sysfs_clear_stats,
&sysfs_running,
&sysfs_state,
&sysfs_label,
&sysfs_readahead,
#ifdef CONFIG_BCACHE_DEBUG
&sysfs_verify,
#endif
NULL
};
KTYPE(bch_cached_dev);
SHOW(bch_flash_dev)
{
struct bcache_device *d = container_of(kobj, struct bcache_device,
kobj);
struct uuid_entry *u = &d->c->uuids[d->id];
sysfs_printf(data_csum, "%i", d->data_csum);
sysfs_hprint(size, u->sectors << 9);
if (attr == &sysfs_label) {
memcpy(buf, u->label, SB_LABEL_SIZE);
buf[SB_LABEL_SIZE + 1] = '\0';
strcat(buf, "\n");
return strlen(buf);
}
return 0;
}
STORE(__bch_flash_dev)
{
struct bcache_device *d = container_of(kobj, struct bcache_device,
kobj);
struct uuid_entry *u = &d->c->uuids[d->id];
sysfs_strtoul(data_csum, d->data_csum);
if (attr == &sysfs_size) {
uint64_t v;
strtoi_h_or_return(buf, v);
u->sectors = v >> 9;
bch_uuid_write(d->c);
set_capacity(d->disk, u->sectors);
}
if (attr == &sysfs_label) {
memcpy(u->label, buf, SB_LABEL_SIZE);
bch_uuid_write(d->c);
}
if (attr == &sysfs_unregister) {
atomic_set(&d->detaching, 1);
bcache_device_stop(d);
}
return size;
}
STORE_LOCKED(bch_flash_dev)
static struct attribute *bch_flash_dev_files[] = {
&sysfs_unregister,
#if 0
&sysfs_data_csum,
#endif
&sysfs_label,
&sysfs_size,
NULL
};
KTYPE(bch_flash_dev);
SHOW(__bch_cache_set)
{
unsigned root_usage(struct cache_set *c)
{
unsigned bytes = 0;
struct bkey *k;
struct btree *b;
struct btree_iter iter;
goto lock_root;
do {
rw_unlock(false, b);
lock_root:
b = c->root;
rw_lock(false, b, b->level);
} while (b != c->root);
for_each_key_filter(b, k, &iter, bch_ptr_bad)
bytes += bkey_bytes(k);
rw_unlock(false, b);
return (bytes * 100) / btree_bytes(c);
}
size_t cache_size(struct cache_set *c)
{
size_t ret = 0;
struct btree *b;
mutex_lock(&c->bucket_lock);
list_for_each_entry(b, &c->btree_cache, list)
ret += 1 << (b->page_order + PAGE_SHIFT);
mutex_unlock(&c->bucket_lock);
return ret;
}
unsigned cache_max_chain(struct cache_set *c)
{
unsigned ret = 0;
struct hlist_head *h;
mutex_lock(&c->bucket_lock);
for (h = c->bucket_hash;
h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
h++) {
unsigned i = 0;
struct hlist_node *p;
hlist_for_each(p, h)
i++;
ret = max(ret, i);
}
mutex_unlock(&c->bucket_lock);
return ret;
}
unsigned btree_used(struct cache_set *c)
{
return div64_u64(c->gc_stats.key_bytes * 100,
(c->gc_stats.nodes ?: 1) * btree_bytes(c));
}
unsigned average_key_size(struct cache_set *c)
{
return c->gc_stats.nkeys
? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
: 0;
}
struct cache_set *c = container_of(kobj, struct cache_set, kobj);
sysfs_print(synchronous, CACHE_SYNC(&c->sb));
sysfs_print(journal_delay_ms, c->journal_delay_ms);
sysfs_hprint(bucket_size, bucket_bytes(c));
sysfs_hprint(block_size, block_bytes(c));
sysfs_print(tree_depth, c->root->level);
sysfs_print(root_usage_percent, root_usage(c));
sysfs_hprint(btree_cache_size, cache_size(c));
sysfs_print(btree_cache_max_chain, cache_max_chain(c));
sysfs_print(cache_available_percent, 100 - c->gc_stats.in_use);
sysfs_print_time_stats(&c->btree_gc_time, btree_gc, sec, ms);
sysfs_print_time_stats(&c->btree_split_time, btree_split, sec, us);
sysfs_print_time_stats(&c->sort_time, btree_sort, ms, us);
sysfs_print_time_stats(&c->btree_read_time, btree_read, ms, us);
sysfs_print_time_stats(&c->try_harder_time, try_harder, ms, us);
sysfs_print(btree_used_percent, btree_used(c));
sysfs_print(btree_nodes, c->gc_stats.nodes);
sysfs_hprint(dirty_data, c->gc_stats.dirty);
sysfs_hprint(average_key_size, average_key_size(c));
sysfs_print(cache_read_races,
atomic_long_read(&c->cache_read_races));
sysfs_print(writeback_keys_done,
atomic_long_read(&c->writeback_keys_done));
sysfs_print(writeback_keys_failed,
atomic_long_read(&c->writeback_keys_failed));
/* See count_io_errors for why 88 */
sysfs_print(io_error_halflife, c->error_decay * 88);
sysfs_print(io_error_limit, c->error_limit >> IO_ERROR_SHIFT);
sysfs_hprint(congested,
((uint64_t) bch_get_congested(c)) << 9);
sysfs_print(congested_read_threshold_us,
c->congested_read_threshold_us);
sysfs_print(congested_write_threshold_us,
c->congested_write_threshold_us);
sysfs_print(active_journal_entries, fifo_used(&c->journal.pin));
sysfs_printf(verify, "%i", c->verify);
sysfs_printf(key_merging_disabled, "%i", c->key_merging_disabled);
sysfs_printf(gc_always_rewrite, "%i", c->gc_always_rewrite);
sysfs_printf(btree_shrinker_disabled, "%i", c->shrinker_disabled);
sysfs_printf(copy_gc_enabled, "%i", c->copy_gc_enabled);
if (attr == &sysfs_bset_tree_stats)
return bch_bset_print_stats(c, buf);
return 0;
}
SHOW_LOCKED(bch_cache_set)
STORE(__bch_cache_set)
{
struct cache_set *c = container_of(kobj, struct cache_set, kobj);
if (attr == &sysfs_unregister)
bch_cache_set_unregister(c);
if (attr == &sysfs_stop)
bch_cache_set_stop(c);
if (attr == &sysfs_synchronous) {
bool sync = strtoul_or_return(buf);
if (sync != CACHE_SYNC(&c->sb)) {
SET_CACHE_SYNC(&c->sb, sync);
bcache_write_super(c);
}
}
if (attr == &sysfs_flash_vol_create) {
int r;
uint64_t v;
strtoi_h_or_return(buf, v);
r = bch_flash_dev_create(c, v);
if (r)
return r;
}
if (attr == &sysfs_clear_stats) {
atomic_long_set(&c->writeback_keys_done, 0);
atomic_long_set(&c->writeback_keys_failed, 0);
memset(&c->gc_stats, 0, sizeof(struct gc_stat));
bch_cache_accounting_clear(&c->accounting);
}
if (attr == &sysfs_trigger_gc)
bch_queue_gc(c);
if (attr == &sysfs_prune_cache) {
struct shrink_control sc;
sc.gfp_mask = GFP_KERNEL;
sc.nr_to_scan = strtoul_or_return(buf);
c->shrink.shrink(&c->shrink, &sc);
}
sysfs_strtoul(congested_read_threshold_us,
c->congested_read_threshold_us);
sysfs_strtoul(congested_write_threshold_us,
c->congested_write_threshold_us);
if (attr == &sysfs_io_error_limit)
c->error_limit = strtoul_or_return(buf) << IO_ERROR_SHIFT;
/* See count_io_errors() for why 88 */
if (attr == &sysfs_io_error_halflife)
c->error_decay = strtoul_or_return(buf) / 88;
sysfs_strtoul(journal_delay_ms, c->journal_delay_ms);
sysfs_strtoul(verify, c->verify);
sysfs_strtoul(key_merging_disabled, c->key_merging_disabled);
sysfs_strtoul(gc_always_rewrite, c->gc_always_rewrite);
sysfs_strtoul(btree_shrinker_disabled, c->shrinker_disabled);
sysfs_strtoul(copy_gc_enabled, c->copy_gc_enabled);
return size;
}
STORE_LOCKED(bch_cache_set)
SHOW(bch_cache_set_internal)
{
struct cache_set *c = container_of(kobj, struct cache_set, internal);
return bch_cache_set_show(&c->kobj, attr, buf);
}
STORE(bch_cache_set_internal)
{
struct cache_set *c = container_of(kobj, struct cache_set, internal);
return bch_cache_set_store(&c->kobj, attr, buf, size);
}
static void bch_cache_set_internal_release(struct kobject *k)
{
}
static struct attribute *bch_cache_set_files[] = {
&sysfs_unregister,
&sysfs_stop,
&sysfs_synchronous,
&sysfs_journal_delay_ms,
&sysfs_flash_vol_create,
&sysfs_bucket_size,
&sysfs_block_size,
&sysfs_tree_depth,
&sysfs_root_usage_percent,
&sysfs_btree_cache_size,
&sysfs_cache_available_percent,
&sysfs_average_key_size,
&sysfs_dirty_data,
&sysfs_io_error_limit,
&sysfs_io_error_halflife,
&sysfs_congested,
&sysfs_congested_read_threshold_us,
&sysfs_congested_write_threshold_us,
&sysfs_clear_stats,
NULL
};
KTYPE(bch_cache_set);
static struct attribute *bch_cache_set_internal_files[] = {
&sysfs_active_journal_entries,
sysfs_time_stats_attribute_list(btree_gc, sec, ms)
sysfs_time_stats_attribute_list(btree_split, sec, us)
sysfs_time_stats_attribute_list(btree_sort, ms, us)
sysfs_time_stats_attribute_list(btree_read, ms, us)
sysfs_time_stats_attribute_list(try_harder, ms, us)
&sysfs_btree_nodes,
&sysfs_btree_used_percent,
&sysfs_btree_cache_max_chain,
&sysfs_bset_tree_stats,
&sysfs_cache_read_races,
&sysfs_writeback_keys_done,
&sysfs_writeback_keys_failed,
&sysfs_trigger_gc,
&sysfs_prune_cache,
#ifdef CONFIG_BCACHE_DEBUG
&sysfs_verify,
&sysfs_key_merging_disabled,
#endif
&sysfs_gc_always_rewrite,
&sysfs_btree_shrinker_disabled,
&sysfs_copy_gc_enabled,
NULL
};
KTYPE(bch_cache_set_internal);
SHOW(__bch_cache)
{
struct cache *ca = container_of(kobj, struct cache, kobj);
sysfs_hprint(bucket_size, bucket_bytes(ca));
sysfs_hprint(block_size, block_bytes(ca));
sysfs_print(nbuckets, ca->sb.nbuckets);
sysfs_print(discard, ca->discard);
sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
sysfs_hprint(btree_written,
atomic_long_read(&ca->btree_sectors_written) << 9);
sysfs_hprint(metadata_written,
(atomic_long_read(&ca->meta_sectors_written) +
atomic_long_read(&ca->btree_sectors_written)) << 9);
sysfs_print(io_errors,
atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
sysfs_print(freelist_percent, ca->free.size * 100 /
((size_t) ca->sb.nbuckets));
if (attr == &sysfs_cache_replacement_policy)
return bch_snprint_string_list(buf, PAGE_SIZE,
cache_replacement_policies,
CACHE_REPLACEMENT(&ca->sb));
if (attr == &sysfs_priority_stats) {
int cmp(const void *l, const void *r)
{ return *((uint16_t *) r) - *((uint16_t *) l); }
/* Number of quantiles we compute */
const unsigned nq = 31;
size_t n = ca->sb.nbuckets, i, unused, btree;
uint64_t sum = 0;
uint16_t q[nq], *p, *cached;
ssize_t ret;
cached = p = vmalloc(ca->sb.nbuckets * sizeof(uint16_t));
if (!p)
return -ENOMEM;
mutex_lock(&ca->set->bucket_lock);
for (i = ca->sb.first_bucket; i < n; i++)
p[i] = ca->buckets[i].prio;
mutex_unlock(&ca->set->bucket_lock);
sort(p, n, sizeof(uint16_t), cmp, NULL);
while (n &&
!cached[n - 1])
--n;
unused = ca->sb.nbuckets - n;
while (cached < p + n &&
*cached == BTREE_PRIO)
cached++;
btree = cached - p;
n -= btree;
for (i = 0; i < n; i++)
sum += INITIAL_PRIO - cached[i];
if (n)
do_div(sum, n);
for (i = 0; i < nq; i++)
q[i] = INITIAL_PRIO - cached[n * (i + 1) / (nq + 1)];
vfree(p);
ret = snprintf(buf, PAGE_SIZE,
"Unused: %zu%%\n"
"Metadata: %zu%%\n"
"Average: %llu\n"
"Sectors per Q: %zu\n"
"Quantiles: [",
unused * 100 / (size_t) ca->sb.nbuckets,
btree * 100 / (size_t) ca->sb.nbuckets, sum,
n * ca->sb.bucket_size / (nq + 1));
for (i = 0; i < nq && ret < (ssize_t) PAGE_SIZE; i++)
ret += snprintf(buf + ret, PAGE_SIZE - ret,
i < nq - 1 ? "%u " : "%u]\n", q[i]);
buf[PAGE_SIZE - 1] = '\0';
return ret;
}
return 0;
}
SHOW_LOCKED(bch_cache)
STORE(__bch_cache)
{
struct cache *ca = container_of(kobj, struct cache, kobj);
if (attr == &sysfs_discard) {
bool v = strtoul_or_return(buf);
if (blk_queue_discard(bdev_get_queue(ca->bdev)))
ca->discard = v;
if (v != CACHE_DISCARD(&ca->sb)) {
SET_CACHE_DISCARD(&ca->sb, v);
bcache_write_super(ca->set);
}
}
if (attr == &sysfs_cache_replacement_policy) {
ssize_t v = bch_read_string_list(buf, cache_replacement_policies);
if (v < 0)
return v;
if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) {
mutex_lock(&ca->set->bucket_lock);
SET_CACHE_REPLACEMENT(&ca->sb, v);
mutex_unlock(&ca->set->bucket_lock);
bcache_write_super(ca->set);
}
}
if (attr == &sysfs_freelist_percent) {
DECLARE_FIFO(long, free);
long i;
size_t p = strtoul_or_return(buf);
p = clamp_t(size_t,
((size_t) ca->sb.nbuckets * p) / 100,
roundup_pow_of_two(ca->sb.nbuckets) >> 9,
ca->sb.nbuckets / 2);
if (!init_fifo_exact(&free, p, GFP_KERNEL))
return -ENOMEM;
mutex_lock(&ca->set->bucket_lock);
fifo_move(&free, &ca->free);
fifo_swap(&free, &ca->free);
mutex_unlock(&ca->set->bucket_lock);
while (fifo_pop(&free, i))
atomic_dec(&ca->buckets[i].pin);
free_fifo(&free);
}
if (attr == &sysfs_clear_stats) {
atomic_long_set(&ca->sectors_written, 0);
atomic_long_set(&ca->btree_sectors_written, 0);
atomic_long_set(&ca->meta_sectors_written, 0);
atomic_set(&ca->io_count, 0);
atomic_set(&ca->io_errors, 0);
}
return size;
}
STORE_LOCKED(bch_cache)
static struct attribute *bch_cache_files[] = {
&sysfs_bucket_size,
&sysfs_block_size,
&sysfs_nbuckets,
&sysfs_priority_stats,
&sysfs_discard,
&sysfs_written,
&sysfs_btree_written,
&sysfs_metadata_written,
&sysfs_io_errors,
&sysfs_clear_stats,
&sysfs_freelist_percent,
&sysfs_cache_replacement_policy,
NULL
};
KTYPE(bch_cache);

110
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#ifndef _BCACHE_SYSFS_H_
#define _BCACHE_SYSFS_H_
#define KTYPE(type) \
struct kobj_type type ## _ktype = { \
.release = type ## _release, \
.sysfs_ops = &((const struct sysfs_ops) { \
.show = type ## _show, \
.store = type ## _store \
}), \
.default_attrs = type ## _files \
}
#define SHOW(fn) \
static ssize_t fn ## _show(struct kobject *kobj, struct attribute *attr,\
char *buf) \
#define STORE(fn) \
static ssize_t fn ## _store(struct kobject *kobj, struct attribute *attr,\
const char *buf, size_t size) \
#define SHOW_LOCKED(fn) \
SHOW(fn) \
{ \
ssize_t ret; \
mutex_lock(&bch_register_lock); \
ret = __ ## fn ## _show(kobj, attr, buf); \
mutex_unlock(&bch_register_lock); \
return ret; \
}
#define STORE_LOCKED(fn) \
STORE(fn) \
{ \
ssize_t ret; \
mutex_lock(&bch_register_lock); \
ret = __ ## fn ## _store(kobj, attr, buf, size); \
mutex_unlock(&bch_register_lock); \
return ret; \
}
#define __sysfs_attribute(_name, _mode) \
static struct attribute sysfs_##_name = \
{ .name = #_name, .mode = _mode }
#define write_attribute(n) __sysfs_attribute(n, S_IWUSR)
#define read_attribute(n) __sysfs_attribute(n, S_IRUGO)
#define rw_attribute(n) __sysfs_attribute(n, S_IRUGO|S_IWUSR)
#define sysfs_printf(file, fmt, ...) \
do { \
if (attr == &sysfs_ ## file) \
return snprintf(buf, PAGE_SIZE, fmt "\n", __VA_ARGS__); \
} while (0)
#define sysfs_print(file, var) \
do { \
if (attr == &sysfs_ ## file) \
return snprint(buf, PAGE_SIZE, var); \
} while (0)
#define sysfs_hprint(file, val) \
do { \
if (attr == &sysfs_ ## file) { \
ssize_t ret = bch_hprint(buf, val); \
strcat(buf, "\n"); \
return ret + 1; \
} \
} while (0)
#define var_printf(_var, fmt) sysfs_printf(_var, fmt, var(_var))
#define var_print(_var) sysfs_print(_var, var(_var))
#define var_hprint(_var) sysfs_hprint(_var, var(_var))
#define sysfs_strtoul(file, var) \
do { \
if (attr == &sysfs_ ## file) \
return strtoul_safe(buf, var) ?: (ssize_t) size; \
} while (0)
#define sysfs_strtoul_clamp(file, var, min, max) \
do { \
if (attr == &sysfs_ ## file) \
return strtoul_safe_clamp(buf, var, min, max) \
?: (ssize_t) size; \
} while (0)
#define strtoul_or_return(cp) \
({ \
unsigned long _v; \
int _r = kstrtoul(cp, 10, &_v); \
if (_r) \
return _r; \
_v; \
})
#define strtoi_h_or_return(cp, v) \
do { \
int _r = strtoi_h(cp, &v); \
if (_r) \
return _r; \
} while (0)
#define sysfs_hatoi(file, var) \
do { \
if (attr == &sysfs_ ## file) \
return strtoi_h(buf, &var) ?: (ssize_t) size; \
} while (0)
#endif /* _BCACHE_SYSFS_H_ */

26
drivers/md/bcache/trace.c Normal file
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#include "bcache.h"
#include "btree.h"
#include "request.h"
#include <linux/module.h>
#define CREATE_TRACE_POINTS
#include <trace/events/bcache.h>
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_request_start);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_request_end);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_passthrough);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_hit);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_miss);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_read_retry);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writethrough);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writeback);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_write_skip);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_read);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_write);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_write_dirty);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_read_dirty);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_journal_write);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_insert);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_start);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_end);

377
drivers/md/bcache/util.c Normal file
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/*
* random utiility code, for bcache but in theory not specific to bcache
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/types.h>
#include "util.h"
#define simple_strtoint(c, end, base) simple_strtol(c, end, base)
#define simple_strtouint(c, end, base) simple_strtoul(c, end, base)
#define STRTO_H(name, type) \
int bch_ ## name ## _h(const char *cp, type *res) \
{ \
int u = 0; \
char *e; \
type i = simple_ ## name(cp, &e, 10); \
\
switch (tolower(*e)) { \
default: \
return -EINVAL; \
case 'y': \
case 'z': \
u++; \
case 'e': \
u++; \
case 'p': \
u++; \
case 't': \
u++; \
case 'g': \
u++; \
case 'm': \
u++; \
case 'k': \
u++; \
if (e++ == cp) \
return -EINVAL; \
case '\n': \
case '\0': \
if (*e == '\n') \
e++; \
} \
\
if (*e) \
return -EINVAL; \
\
while (u--) { \
if ((type) ~0 > 0 && \
(type) ~0 / 1024 <= i) \
return -EINVAL; \
if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) || \
(i < 0 && -ANYSINT_MAX(type) / 1024 > i)) \
return -EINVAL; \
i *= 1024; \
} \
\
*res = i; \
return 0; \
} \
STRTO_H(strtoint, int)
STRTO_H(strtouint, unsigned int)
STRTO_H(strtoll, long long)
STRTO_H(strtoull, unsigned long long)
ssize_t bch_hprint(char *buf, int64_t v)
{
static const char units[] = "?kMGTPEZY";
char dec[4] = "";
int u, t = 0;
for (u = 0; v >= 1024 || v <= -1024; u++) {
t = v & ~(~0 << 10);
v >>= 10;
}
if (!u)
return sprintf(buf, "%llu", v);
if (v < 100 && v > -100)
snprintf(dec, sizeof(dec), ".%i", t / 100);
return sprintf(buf, "%lli%s%c", v, dec, units[u]);
}
ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
size_t selected)
{
char *out = buf;
size_t i;
for (i = 0; list[i]; i++)
out += snprintf(out, buf + size - out,
i == selected ? "[%s] " : "%s ", list[i]);
out[-1] = '\n';
return out - buf;
}
ssize_t bch_read_string_list(const char *buf, const char * const list[])
{
size_t i;
char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
if (!d)
return -ENOMEM;
s = strim(d);
for (i = 0; list[i]; i++)
if (!strcmp(list[i], s))
break;
kfree(d);
if (!list[i])
return -EINVAL;
return i;
}
bool bch_is_zero(const char *p, size_t n)
{
size_t i;
for (i = 0; i < n; i++)
if (p[i])
return false;
return true;
}
int bch_parse_uuid(const char *s, char *uuid)
{
size_t i, j, x;
memset(uuid, 0, 16);
for (i = 0, j = 0;
i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
i++) {
x = s[i] | 32;
switch (x) {
case '0'...'9':
x -= '0';
break;
case 'a'...'f':
x -= 'a' - 10;
break;
default:
continue;
}
if (!(j & 1))
x <<= 4;
uuid[j++ >> 1] |= x;
}
return i;
}
void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
{
uint64_t now = local_clock();
uint64_t duration = time_after64(now, start_time)
? now - start_time : 0;
uint64_t last = time_after64(now, stats->last)
? now - stats->last : 0;
stats->max_duration = max(stats->max_duration, duration);
if (stats->last) {
ewma_add(stats->average_duration, duration, 8, 8);
if (stats->average_frequency)
ewma_add(stats->average_frequency, last, 8, 8);
else
stats->average_frequency = last << 8;
} else {
stats->average_duration = duration << 8;
}
stats->last = now ?: 1;
}
unsigned bch_next_delay(struct ratelimit *d, uint64_t done)
{
uint64_t now = local_clock();
d->next += div_u64(done, d->rate);
return time_after64(d->next, now)
? div_u64(d->next - now, NSEC_PER_SEC / HZ)
: 0;
}
void bch_bio_map(struct bio *bio, void *base)
{
size_t size = bio->bi_size;
struct bio_vec *bv = bio->bi_io_vec;
BUG_ON(!bio->bi_size);
BUG_ON(bio->bi_vcnt);
bv->bv_offset = base ? ((unsigned long) base) % PAGE_SIZE : 0;
goto start;
for (; size; bio->bi_vcnt++, bv++) {
bv->bv_offset = 0;
start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset,
size);
if (base) {
bv->bv_page = is_vmalloc_addr(base)
? vmalloc_to_page(base)
: virt_to_page(base);
base += bv->bv_len;
}
size -= bv->bv_len;
}
}
int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp)
{
int i;
struct bio_vec *bv;
bio_for_each_segment(bv, bio, i) {
bv->bv_page = alloc_page(gfp);
if (!bv->bv_page) {
while (bv-- != bio->bi_io_vec + bio->bi_idx)
__free_page(bv->bv_page);
return -ENOMEM;
}
}
return 0;
}
/*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
* use permitted, subject to terms of PostgreSQL license; see.)
* If we have a 64-bit integer type, then a 64-bit CRC looks just like the
* usual sort of implementation. (See Ross Williams' excellent introduction
* A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
* ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
* If we have no working 64-bit type, then fake it with two 32-bit registers.
*
* The present implementation is a normal (not "reflected", in Williams'
* terms) 64-bit CRC, using initial all-ones register contents and a final
* bit inversion. The chosen polynomial is borrowed from the DLT1 spec
* (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
*
* x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
* x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
* x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
* x^7 + x^4 + x + 1
*/
static const uint64_t crc_table[256] = {
0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
0x9AFCE626CE85B507ULL,
};
uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
{
const unsigned char *data = _data;
while (len--) {
int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
crc = crc_table[i] ^ (crc << 8);
}
return crc;
}
uint64_t bch_crc64(const void *data, size_t len)
{
uint64_t crc = 0xffffffffffffffffULL;
crc = bch_crc64_update(crc, data, len);
return crc ^ 0xffffffffffffffffULL;
}

589
drivers/md/bcache/util.h Normal file
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#ifndef _BCACHE_UTIL_H
#define _BCACHE_UTIL_H
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/llist.h>
#include <linux/ratelimit.h>
#include <linux/vmalloc.h>
#include <linux/workqueue.h>
#include "closure.h"
#define PAGE_SECTORS (PAGE_SIZE / 512)
struct closure;
#include <trace/events/bcache.h>
#ifdef CONFIG_BCACHE_EDEBUG
#define atomic_dec_bug(v) BUG_ON(atomic_dec_return(v) < 0)
#define atomic_inc_bug(v, i) BUG_ON(atomic_inc_return(v) <= i)
#else /* EDEBUG */
#define atomic_dec_bug(v) atomic_dec(v)
#define atomic_inc_bug(v, i) atomic_inc(v)
#endif
#define BITMASK(name, type, field, offset, size) \
static inline uint64_t name(const type *k) \
{ return (k->field >> offset) & ~(((uint64_t) ~0) << size); } \
\
static inline void SET_##name(type *k, uint64_t v) \
{ \
k->field &= ~(~((uint64_t) ~0 << size) << offset); \
k->field |= v << offset; \
}
#define DECLARE_HEAP(type, name) \
struct { \
size_t size, used; \
type *data; \
} name
#define init_heap(heap, _size, gfp) \
({ \
size_t _bytes; \
(heap)->used = 0; \
(heap)->size = (_size); \
_bytes = (heap)->size * sizeof(*(heap)->data); \
(heap)->data = NULL; \
if (_bytes < KMALLOC_MAX_SIZE) \
(heap)->data = kmalloc(_bytes, (gfp)); \
if ((!(heap)->data) && ((gfp) & GFP_KERNEL)) \
(heap)->data = vmalloc(_bytes); \
(heap)->data; \
})
#define free_heap(heap) \
do { \
if (is_vmalloc_addr((heap)->data)) \
vfree((heap)->data); \
else \
kfree((heap)->data); \
(heap)->data = NULL; \
} while (0)
#define heap_swap(h, i, j) swap((h)->data[i], (h)->data[j])
#define heap_sift(h, i, cmp) \
do { \
size_t _r, _j = i; \
\
for (; _j * 2 + 1 < (h)->used; _j = _r) { \
_r = _j * 2 + 1; \
if (_r + 1 < (h)->used && \
cmp((h)->data[_r], (h)->data[_r + 1])) \
_r++; \
\
if (cmp((h)->data[_r], (h)->data[_j])) \
break; \
heap_swap(h, _r, _j); \
} \
} while (0)
#define heap_sift_down(h, i, cmp) \
do { \
while (i) { \
size_t p = (i - 1) / 2; \
if (cmp((h)->data[i], (h)->data[p])) \
break; \
heap_swap(h, i, p); \
i = p; \
} \
} while (0)
#define heap_add(h, d, cmp) \
({ \
bool _r = !heap_full(h); \
if (_r) { \
size_t _i = (h)->used++; \
(h)->data[_i] = d; \
\
heap_sift_down(h, _i, cmp); \
heap_sift(h, _i, cmp); \
} \
_r; \
})
#define heap_pop(h, d, cmp) \
({ \
bool _r = (h)->used; \
if (_r) { \
(d) = (h)->data[0]; \
(h)->used--; \
heap_swap(h, 0, (h)->used); \
heap_sift(h, 0, cmp); \
} \
_r; \
})
#define heap_peek(h) ((h)->size ? (h)->data[0] : NULL)
#define heap_full(h) ((h)->used == (h)->size)
#define DECLARE_FIFO(type, name) \
struct { \
size_t front, back, size, mask; \
type *data; \
} name
#define fifo_for_each(c, fifo, iter) \
for (iter = (fifo)->front; \
c = (fifo)->data[iter], iter != (fifo)->back; \
iter = (iter + 1) & (fifo)->mask)
#define __init_fifo(fifo, gfp) \
({ \
size_t _allocated_size, _bytes; \
BUG_ON(!(fifo)->size); \
\
_allocated_size = roundup_pow_of_two((fifo)->size + 1); \
_bytes = _allocated_size * sizeof(*(fifo)->data); \
\
(fifo)->mask = _allocated_size - 1; \
(fifo)->front = (fifo)->back = 0; \
(fifo)->data = NULL; \
\
if (_bytes < KMALLOC_MAX_SIZE) \
(fifo)->data = kmalloc(_bytes, (gfp)); \
if ((!(fifo)->data) && ((gfp) & GFP_KERNEL)) \
(fifo)->data = vmalloc(_bytes); \
(fifo)->data; \
})
#define init_fifo_exact(fifo, _size, gfp) \
({ \
(fifo)->size = (_size); \
__init_fifo(fifo, gfp); \
})
#define init_fifo(fifo, _size, gfp) \
({ \
(fifo)->size = (_size); \
if ((fifo)->size > 4) \
(fifo)->size = roundup_pow_of_two((fifo)->size) - 1; \
__init_fifo(fifo, gfp); \
})
#define free_fifo(fifo) \
do { \
if (is_vmalloc_addr((fifo)->data)) \
vfree((fifo)->data); \
else \
kfree((fifo)->data); \
(fifo)->data = NULL; \
} while (0)
#define fifo_used(fifo) (((fifo)->back - (fifo)->front) & (fifo)->mask)
#define fifo_free(fifo) ((fifo)->size - fifo_used(fifo))
#define fifo_empty(fifo) (!fifo_used(fifo))
#define fifo_full(fifo) (!fifo_free(fifo))
#define fifo_front(fifo) ((fifo)->data[(fifo)->front])
#define fifo_back(fifo) \
((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
#define fifo_idx(fifo, p) (((p) - &fifo_front(fifo)) & (fifo)->mask)
#define fifo_push_back(fifo, i) \
({ \
bool _r = !fifo_full((fifo)); \
if (_r) { \
(fifo)->data[(fifo)->back++] = (i); \
(fifo)->back &= (fifo)->mask; \
} \
_r; \
})
#define fifo_pop_front(fifo, i) \
({ \
bool _r = !fifo_empty((fifo)); \
if (_r) { \
(i) = (fifo)->data[(fifo)->front++]; \
(fifo)->front &= (fifo)->mask; \
} \
_r; \
})
#define fifo_push_front(fifo, i) \
({ \
bool _r = !fifo_full((fifo)); \
if (_r) { \
--(fifo)->front; \
(fifo)->front &= (fifo)->mask; \
(fifo)->data[(fifo)->front] = (i); \
} \
_r; \
})
#define fifo_pop_back(fifo, i) \
({ \
bool _r = !fifo_empty((fifo)); \
if (_r) { \
--(fifo)->back; \
(fifo)->back &= (fifo)->mask; \
(i) = (fifo)->data[(fifo)->back] \
} \
_r; \
})
#define fifo_push(fifo, i) fifo_push_back(fifo, (i))
#define fifo_pop(fifo, i) fifo_pop_front(fifo, (i))
#define fifo_swap(l, r) \
do { \
swap((l)->front, (r)->front); \
swap((l)->back, (r)->back); \
swap((l)->size, (r)->size); \
swap((l)->mask, (r)->mask); \
swap((l)->data, (r)->data); \
} while (0)
#define fifo_move(dest, src) \
do { \
typeof(*((dest)->data)) _t; \
while (!fifo_full(dest) && \
fifo_pop(src, _t)) \
fifo_push(dest, _t); \
} while (0)
/*
* Simple array based allocator - preallocates a number of elements and you can
* never allocate more than that, also has no locking.
*
* Handy because if you know you only need a fixed number of elements you don't
* have to worry about memory allocation failure, and sometimes a mempool isn't
* what you want.
*
* We treat the free elements as entries in a singly linked list, and the
* freelist as a stack - allocating and freeing push and pop off the freelist.
*/
#define DECLARE_ARRAY_ALLOCATOR(type, name, size) \
struct { \
type *freelist; \
type data[size]; \
} name
#define array_alloc(array) \
({ \
typeof((array)->freelist) _ret = (array)->freelist; \
\
if (_ret) \
(array)->freelist = *((typeof((array)->freelist) *) _ret);\
\
_ret; \
})
#define array_free(array, ptr) \
do { \
typeof((array)->freelist) _ptr = ptr; \
\
*((typeof((array)->freelist) *) _ptr) = (array)->freelist; \
(array)->freelist = _ptr; \
} while (0)
#define array_allocator_init(array) \
do { \
typeof((array)->freelist) _i; \
\
BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *)); \
(array)->freelist = NULL; \
\
for (_i = (array)->data; \
_i < (array)->data + ARRAY_SIZE((array)->data); \
_i++) \
array_free(array, _i); \
} while (0)
#define array_freelist_empty(array) ((array)->freelist == NULL)
#define ANYSINT_MAX(t) \
((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
int bch_strtoint_h(const char *, int *);
int bch_strtouint_h(const char *, unsigned int *);
int bch_strtoll_h(const char *, long long *);
int bch_strtoull_h(const char *, unsigned long long *);
static inline int bch_strtol_h(const char *cp, long *res)
{
#if BITS_PER_LONG == 32
return bch_strtoint_h(cp, (int *) res);
#else
return bch_strtoll_h(cp, (long long *) res);
#endif
}
static inline int bch_strtoul_h(const char *cp, long *res)
{
#if BITS_PER_LONG == 32
return bch_strtouint_h(cp, (unsigned int *) res);
#else
return bch_strtoull_h(cp, (unsigned long long *) res);
#endif
}
#define strtoi_h(cp, res) \
(__builtin_types_compatible_p(typeof(*res), int) \
? bch_strtoint_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), long) \
? bch_strtol_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), long long) \
? bch_strtoll_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), unsigned int) \
? bch_strtouint_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), unsigned long) \
? bch_strtoul_h(cp, (void *) res) \
: __builtin_types_compatible_p(typeof(*res), unsigned long long)\
? bch_strtoull_h(cp, (void *) res) : -EINVAL)
#define strtoul_safe(cp, var) \
({ \
unsigned long _v; \
int _r = kstrtoul(cp, 10, &_v); \
if (!_r) \
var = _v; \
_r; \
})
#define strtoul_safe_clamp(cp, var, min, max) \
({ \
unsigned long _v; \
int _r = kstrtoul(cp, 10, &_v); \
if (!_r) \
var = clamp_t(typeof(var), _v, min, max); \
_r; \
})
#define snprint(buf, size, var) \
snprintf(buf, size, \
__builtin_types_compatible_p(typeof(var), int) \
? "%i\n" : \
__builtin_types_compatible_p(typeof(var), unsigned) \
? "%u\n" : \
__builtin_types_compatible_p(typeof(var), long) \
? "%li\n" : \
__builtin_types_compatible_p(typeof(var), unsigned long)\
? "%lu\n" : \
__builtin_types_compatible_p(typeof(var), int64_t) \
? "%lli\n" : \
__builtin_types_compatible_p(typeof(var), uint64_t) \
? "%llu\n" : \
__builtin_types_compatible_p(typeof(var), const char *) \
? "%s\n" : "%i\n", var)
ssize_t bch_hprint(char *buf, int64_t v);
bool bch_is_zero(const char *p, size_t n);
int bch_parse_uuid(const char *s, char *uuid);
ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
size_t selected);
ssize_t bch_read_string_list(const char *buf, const char * const list[]);
struct time_stats {
/*
* all fields are in nanoseconds, averages are ewmas stored left shifted
* by 8
*/
uint64_t max_duration;
uint64_t average_duration;
uint64_t average_frequency;
uint64_t last;
};
void bch_time_stats_update(struct time_stats *stats, uint64_t time);
#define NSEC_PER_ns 1L
#define NSEC_PER_us NSEC_PER_USEC
#define NSEC_PER_ms NSEC_PER_MSEC
#define NSEC_PER_sec NSEC_PER_SEC
#define __print_time_stat(stats, name, stat, units) \
sysfs_print(name ## _ ## stat ## _ ## units, \
div_u64((stats)->stat >> 8, NSEC_PER_ ## units))
#define sysfs_print_time_stats(stats, name, \
frequency_units, \
duration_units) \
do { \
__print_time_stat(stats, name, \
average_frequency, frequency_units); \
__print_time_stat(stats, name, \
average_duration, duration_units); \
__print_time_stat(stats, name, \
max_duration, duration_units); \
\
sysfs_print(name ## _last_ ## frequency_units, (stats)->last \
? div_s64(local_clock() - (stats)->last, \
NSEC_PER_ ## frequency_units) \
: -1LL); \
} while (0)
#define sysfs_time_stats_attribute(name, \
frequency_units, \
duration_units) \
read_attribute(name ## _average_frequency_ ## frequency_units); \
read_attribute(name ## _average_duration_ ## duration_units); \
read_attribute(name ## _max_duration_ ## duration_units); \
read_attribute(name ## _last_ ## frequency_units)
#define sysfs_time_stats_attribute_list(name, \
frequency_units, \
duration_units) \
&sysfs_ ## name ## _average_frequency_ ## frequency_units, \
&sysfs_ ## name ## _average_duration_ ## duration_units, \
&sysfs_ ## name ## _max_duration_ ## duration_units, \
&sysfs_ ## name ## _last_ ## frequency_units,
#define ewma_add(ewma, val, weight, factor) \
({ \
(ewma) *= (weight) - 1; \
(ewma) += (val) << factor; \
(ewma) /= (weight); \
(ewma) >> factor; \
})
struct ratelimit {
uint64_t next;
unsigned rate;
};
static inline void ratelimit_reset(struct ratelimit *d)
{
d->next = local_clock();
}
unsigned bch_next_delay(struct ratelimit *d, uint64_t done);
#define __DIV_SAFE(n, d, zero) \
({ \
typeof(n) _n = (n); \
typeof(d) _d = (d); \
_d ? _n / _d : zero; \
})
#define DIV_SAFE(n, d) __DIV_SAFE(n, d, 0)
#define container_of_or_null(ptr, type, member) \
({ \
typeof(ptr) _ptr = ptr; \
_ptr ? container_of(_ptr, type, member) : NULL; \
})
#define RB_INSERT(root, new, member, cmp) \
({ \
__label__ dup; \
struct rb_node **n = &(root)->rb_node, *parent = NULL; \
typeof(new) this; \
int res, ret = -1; \
\
while (*n) { \
parent = *n; \
this = container_of(*n, typeof(*(new)), member); \
res = cmp(new, this); \
if (!res) \
goto dup; \
n = res < 0 \
? &(*n)->rb_left \
: &(*n)->rb_right; \
} \
\
rb_link_node(&(new)->member, parent, n); \
rb_insert_color(&(new)->member, root); \
ret = 0; \
dup: \
ret; \
})
#define RB_SEARCH(root, search, member, cmp) \
({ \
struct rb_node *n = (root)->rb_node; \
typeof(&(search)) this, ret = NULL; \
int res; \
\
while (n) { \
this = container_of(n, typeof(search), member); \
res = cmp(&(search), this); \
if (!res) { \
ret = this; \
break; \
} \
n = res < 0 \
? n->rb_left \
: n->rb_right; \
} \
ret; \
})
#define RB_GREATER(root, search, member, cmp) \
({ \
struct rb_node *n = (root)->rb_node; \
typeof(&(search)) this, ret = NULL; \
int res; \
\
while (n) { \
this = container_of(n, typeof(search), member); \
res = cmp(&(search), this); \
if (res < 0) { \
ret = this; \
n = n->rb_left; \
} else \
n = n->rb_right; \
} \
ret; \
})
#define RB_FIRST(root, type, member) \
container_of_or_null(rb_first(root), type, member)
#define RB_LAST(root, type, member) \
container_of_or_null(rb_last(root), type, member)
#define RB_NEXT(ptr, member) \
container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)
#define RB_PREV(ptr, member) \
container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)
/* Does linear interpolation between powers of two */
static inline unsigned fract_exp_two(unsigned x, unsigned fract_bits)
{
unsigned fract = x & ~(~0 << fract_bits);
x >>= fract_bits;
x = 1 << x;
x += (x * fract) >> fract_bits;
return x;
}
#define bio_end(bio) ((bio)->bi_sector + bio_sectors(bio))
void bch_bio_map(struct bio *bio, void *base);
int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp);
static inline sector_t bdev_sectors(struct block_device *bdev)
{
return bdev->bd_inode->i_size >> 9;
}
#define closure_bio_submit(bio, cl, dev) \
do { \
closure_get(cl); \
bch_generic_make_request(bio, &(dev)->bio_split_hook); \
} while (0)
uint64_t bch_crc64_update(uint64_t, const void *, size_t);
uint64_t bch_crc64(const void *, size_t);
#endif /* _BCACHE_UTIL_H */

414
drivers/md/bcache/writeback.c Normal file
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@ -0,0 +1,414 @@
/*
* background writeback - scan btree for dirty data and write it to the backing
* device
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
static struct workqueue_struct *dirty_wq;
static void read_dirty(struct closure *);
struct dirty_io {
struct closure cl;
struct cached_dev *dc;
struct bio bio;
};
/* Rate limiting */
static void __update_writeback_rate(struct cached_dev *dc)
{
struct cache_set *c = dc->disk.c;
uint64_t cache_sectors = c->nbuckets * c->sb.bucket_size;
uint64_t cache_dirty_target =
div_u64(cache_sectors * dc->writeback_percent, 100);
int64_t target = div64_u64(cache_dirty_target * bdev_sectors(dc->bdev),
c->cached_dev_sectors);
/* PD controller */
int change = 0;
int64_t error;
int64_t dirty = atomic_long_read(&dc->disk.sectors_dirty);
int64_t derivative = dirty - dc->disk.sectors_dirty_last;
dc->disk.sectors_dirty_last = dirty;
derivative *= dc->writeback_rate_d_term;
derivative = clamp(derivative, -dirty, dirty);
derivative = ewma_add(dc->disk.sectors_dirty_derivative, derivative,
dc->writeback_rate_d_smooth, 0);
/* Avoid divide by zero */
if (!target)
goto out;
error = div64_s64((dirty + derivative - target) << 8, target);
change = div_s64((dc->writeback_rate.rate * error) >> 8,
dc->writeback_rate_p_term_inverse);
/* Don't increase writeback rate if the device isn't keeping up */
if (change > 0 &&
time_after64(local_clock(),
dc->writeback_rate.next + 10 * NSEC_PER_MSEC))
change = 0;
dc->writeback_rate.rate =
clamp_t(int64_t, dc->writeback_rate.rate + change,
1, NSEC_PER_MSEC);
out:
dc->writeback_rate_derivative = derivative;
dc->writeback_rate_change = change;
dc->writeback_rate_target = target;
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
}
static void update_writeback_rate(struct work_struct *work)
{
struct cached_dev *dc = container_of(to_delayed_work(work),
struct cached_dev,
writeback_rate_update);
down_read(&dc->writeback_lock);
if (atomic_read(&dc->has_dirty) &&
dc->writeback_percent)
__update_writeback_rate(dc);
up_read(&dc->writeback_lock);
}
static unsigned writeback_delay(struct cached_dev *dc, unsigned sectors)
{
if (atomic_read(&dc->disk.detaching) ||
!dc->writeback_percent)
return 0;
return bch_next_delay(&dc->writeback_rate, sectors * 10000000ULL);
}
/* Background writeback */
static bool dirty_pred(struct keybuf *buf, struct bkey *k)
{
return KEY_DIRTY(k);
}
static void dirty_init(struct keybuf_key *w)
{
struct dirty_io *io = w->private;
struct bio *bio = &io->bio;
bio_init(bio);
if (!io->dc->writeback_percent)
bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
bio->bi_size = KEY_SIZE(&w->key) << 9;
bio->bi_max_vecs = DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS);
bio->bi_private = w;
bio->bi_io_vec = bio->bi_inline_vecs;
bch_bio_map(bio, NULL);
}
static void refill_dirty(struct closure *cl)
{
struct cached_dev *dc = container_of(cl, struct cached_dev,
writeback.cl);
struct keybuf *buf = &dc->writeback_keys;
bool searched_from_start = false;
struct bkey end = MAX_KEY;
SET_KEY_INODE(&end, dc->disk.id);
if (!atomic_read(&dc->disk.detaching) &&
!dc->writeback_running)
closure_return(cl);
down_write(&dc->writeback_lock);
if (!atomic_read(&dc->has_dirty)) {
SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
bch_write_bdev_super(dc, NULL);
up_write(&dc->writeback_lock);
closure_return(cl);
}
if (bkey_cmp(&buf->last_scanned, &end) >= 0) {
buf->last_scanned = KEY(dc->disk.id, 0, 0);
searched_from_start = true;
}
bch_refill_keybuf(dc->disk.c, buf, &end);
if (bkey_cmp(&buf->last_scanned, &end) >= 0 && searched_from_start) {
/* Searched the entire btree - delay awhile */
if (RB_EMPTY_ROOT(&buf->keys)) {
atomic_set(&dc->has_dirty, 0);
cached_dev_put(dc);
}
if (!atomic_read(&dc->disk.detaching))
closure_delay(&dc->writeback, dc->writeback_delay * HZ);
}
up_write(&dc->writeback_lock);
ratelimit_reset(&dc->writeback_rate);
/* Punt to workqueue only so we don't recurse and blow the stack */
continue_at(cl, read_dirty, dirty_wq);
}
void bch_writeback_queue(struct cached_dev *dc)
{
if (closure_trylock(&dc->writeback.cl, &dc->disk.cl)) {
if (!atomic_read(&dc->disk.detaching))
closure_delay(&dc->writeback, dc->writeback_delay * HZ);
continue_at(&dc->writeback.cl, refill_dirty, dirty_wq);
}
}
void bch_writeback_add(struct cached_dev *dc, unsigned sectors)
{
atomic_long_add(sectors, &dc->disk.sectors_dirty);
if (!atomic_read(&dc->has_dirty) &&
!atomic_xchg(&dc->has_dirty, 1)) {
atomic_inc(&dc->count);
if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
/* XXX: should do this synchronously */
bch_write_bdev_super(dc, NULL);
}
bch_writeback_queue(dc);
if (dc->writeback_percent)
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
}
}
/* Background writeback - IO loop */
static void dirty_io_destructor(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
kfree(io);
}
static void write_dirty_finish(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
struct keybuf_key *w = io->bio.bi_private;
struct cached_dev *dc = io->dc;
struct bio_vec *bv = bio_iovec_idx(&io->bio, io->bio.bi_vcnt);
while (bv-- != io->bio.bi_io_vec)
__free_page(bv->bv_page);
/* This is kind of a dumb way of signalling errors. */
if (KEY_DIRTY(&w->key)) {
unsigned i;
struct btree_op op;
bch_btree_op_init_stack(&op);
op.type = BTREE_REPLACE;
bkey_copy(&op.replace, &w->key);
SET_KEY_DIRTY(&w->key, false);
bch_keylist_add(&op.keys, &w->key);
for (i = 0; i < KEY_PTRS(&w->key); i++)
atomic_inc(&PTR_BUCKET(dc->disk.c, &w->key, i)->pin);
pr_debug("clearing %s", pkey(&w->key));
bch_btree_insert(&op, dc->disk.c);
closure_sync(&op.cl);
atomic_long_inc(op.insert_collision
? &dc->disk.c->writeback_keys_failed
: &dc->disk.c->writeback_keys_done);
}
bch_keybuf_del(&dc->writeback_keys, w);
atomic_dec_bug(&dc->in_flight);
closure_wake_up(&dc->writeback_wait);
closure_return_with_destructor(cl, dirty_io_destructor);
}
static void dirty_endio(struct bio *bio, int error)
{
struct keybuf_key *w = bio->bi_private;
struct dirty_io *io = w->private;
if (error)
SET_KEY_DIRTY(&w->key, false);
closure_put(&io->cl);
}
static void write_dirty(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
struct keybuf_key *w = io->bio.bi_private;
dirty_init(w);
io->bio.bi_rw = WRITE;
io->bio.bi_sector = KEY_START(&w->key);
io->bio.bi_bdev = io->dc->bdev;
io->bio.bi_end_io = dirty_endio;
trace_bcache_write_dirty(&io->bio);
closure_bio_submit(&io->bio, cl, &io->dc->disk);
continue_at(cl, write_dirty_finish, dirty_wq);
}
static void read_dirty_endio(struct bio *bio, int error)
{
struct keybuf_key *w = bio->bi_private;
struct dirty_io *io = w->private;
bch_count_io_errors(PTR_CACHE(io->dc->disk.c, &w->key, 0),
error, "reading dirty data from cache");
dirty_endio(bio, error);
}
static void read_dirty_submit(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
trace_bcache_read_dirty(&io->bio);
closure_bio_submit(&io->bio, cl, &io->dc->disk);
continue_at(cl, write_dirty, dirty_wq);
}
static void read_dirty(struct closure *cl)
{
struct cached_dev *dc = container_of(cl, struct cached_dev,
writeback.cl);
unsigned delay = writeback_delay(dc, 0);
struct keybuf_key *w;
struct dirty_io *io;
/*
* XXX: if we error, background writeback just spins. Should use some
* mempools.
*/
while (1) {
w = bch_keybuf_next(&dc->writeback_keys);
if (!w)
break;
BUG_ON(ptr_stale(dc->disk.c, &w->key, 0));
if (delay > 0 &&
(KEY_START(&w->key) != dc->last_read ||
jiffies_to_msecs(delay) > 50)) {
w->private = NULL;
closure_delay(&dc->writeback, delay);
continue_at(cl, read_dirty, dirty_wq);
}
dc->last_read = KEY_OFFSET(&w->key);
io = kzalloc(sizeof(struct dirty_io) + sizeof(struct bio_vec)
* DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS),
GFP_KERNEL);
if (!io)
goto err;
w->private = io;
io->dc = dc;
dirty_init(w);
io->bio.bi_sector = PTR_OFFSET(&w->key, 0);
io->bio.bi_bdev = PTR_CACHE(dc->disk.c,
&w->key, 0)->bdev;
io->bio.bi_rw = READ;
io->bio.bi_end_io = read_dirty_endio;
if (bch_bio_alloc_pages(&io->bio, GFP_KERNEL))
goto err_free;
pr_debug("%s", pkey(&w->key));
closure_call(&io->cl, read_dirty_submit, NULL, &dc->disk.cl);
delay = writeback_delay(dc, KEY_SIZE(&w->key));
atomic_inc(&dc->in_flight);
if (!closure_wait_event(&dc->writeback_wait, cl,
atomic_read(&dc->in_flight) < 64))
continue_at(cl, read_dirty, dirty_wq);
}
if (0) {
err_free:
kfree(w->private);
err:
bch_keybuf_del(&dc->writeback_keys, w);
}
refill_dirty(cl);
}
void bch_writeback_init_cached_dev(struct cached_dev *dc)
{
closure_init_unlocked(&dc->writeback);
init_rwsem(&dc->writeback_lock);
bch_keybuf_init(&dc->writeback_keys, dirty_pred);
dc->writeback_metadata = true;
dc->writeback_running = true;
dc->writeback_percent = 10;
dc->writeback_delay = 30;
dc->writeback_rate.rate = 1024;
dc->writeback_rate_update_seconds = 30;
dc->writeback_rate_d_term = 16;
dc->writeback_rate_p_term_inverse = 64;
dc->writeback_rate_d_smooth = 8;
INIT_DELAYED_WORK(&dc->writeback_rate_update, update_writeback_rate);
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
}
void bch_writeback_exit(void)
{
if (dirty_wq)
destroy_workqueue(dirty_wq);
}
int __init bch_writeback_init(void)
{
dirty_wq = create_singlethread_workqueue("bcache_writeback");
if (!dirty_wq)
return -ENOMEM;
return 0;
}

6
include/linux/cgroup_subsys.h
View file

@ -78,3 +78,9 @@ SUBSYS(hugetlb)
#endif
/* */
#ifdef CONFIG_CGROUP_BCACHE
SUBSYS(bcache)
#endif
/* */

5
include/linux/drbd.h
View file

@ -52,7 +52,7 @@
#endif
extern const char *drbd_buildtag(void);
#define REL_VERSION "8.4.2"
#define REL_VERSION "8.4.3"
#define API_VERSION 1
#define PRO_VERSION_MIN 86
#define PRO_VERSION_MAX 101
@ -319,7 +319,8 @@ enum drbd_state_rv {
SS_IN_TRANSIENT_STATE = -18, /* Retry after the next state change */
SS_CONCURRENT_ST_CHG = -19, /* Concurrent cluster side state change! */
SS_O_VOL_PEER_PRI = -20,
SS_AFTER_LAST_ERROR = -21, /* Keep this at bottom */
SS_OUTDATE_WO_CONN = -21,
SS_AFTER_LAST_ERROR = -22, /* Keep this at bottom */
};
/* from drbd_strings.c */

11
include/linux/drbd_limits.h
View file

@ -126,13 +126,12 @@
#define DRBD_RESYNC_RATE_DEF 250
#define DRBD_RESYNC_RATE_SCALE 'k' /* kilobytes */
/* less than 7 would hit performance unnecessarily.
* 919 slots context information per transaction,
* 32k activity log, 4k transaction size,
* one transaction in flight:
* 919 * 7 = 6433 */
/* less than 7 would hit performance unnecessarily. */
#define DRBD_AL_EXTENTS_MIN 7
#define DRBD_AL_EXTENTS_MAX 6433
/* we use u16 as "slot number", (u16)~0 is "FREE".
* If you use >= 292 kB on-disk ring buffer,
* this is the maximum you can use: */
#define DRBD_AL_EXTENTS_MAX 0xfffe
#define DRBD_AL_EXTENTS_DEF 1237
#define DRBD_AL_EXTENTS_SCALE '1'

10
include/linux/idr.h
View file

@ -124,11 +124,13 @@ static inline void *idr_find(struct idr *idr, int id)
* @idp: idr handle
* @entry: the type * to use as cursor
* @id: id entry's key
*
* @entry and @id do not need to be initialized before the loop, and
* after normal terminatinon @entry is left with the value NULL. This
* is convenient for a "not found" value.
*/
#define idr_for_each_entry(idp, entry, id) \
for (id = 0, entry = (typeof(entry))idr_get_next((idp), &(id)); \
entry != NULL; \
++id, entry = (typeof(entry))idr_get_next((idp), &(id)))
#define idr_for_each_entry(idp, entry, id) \
for (id = 0; ((entry) = idr_get_next(idp, &(id))) != NULL; ++id)
/*
* Don't use the following functions. These exist only to suppress

1
include/linux/lru_cache.h
View file

@ -256,6 +256,7 @@ extern void lc_destroy(struct lru_cache *lc);
extern void lc_set(struct lru_cache *lc, unsigned int enr, int index);
extern void lc_del(struct lru_cache *lc, struct lc_element *element);
extern struct lc_element *lc_get_cumulative(struct lru_cache *lc, unsigned int enr);
extern struct lc_element *lc_try_get(struct lru_cache *lc, unsigned int enr);
extern struct lc_element *lc_find(struct lru_cache *lc, unsigned int enr);
extern struct lc_element *lc_get(struct lru_cache *lc, unsigned int enr);

10
include/linux/rwsem.h
View file

@ -133,10 +133,20 @@ do { \
_down_write_nest_lock(sem, &(nest_lock)->dep_map); \
} while (0);
/*
* Take/release a lock when not the owner will release it.
*
* [ This API should be avoided as much as possible - the
* proper abstraction for this case is completions. ]
*/
extern void down_read_non_owner(struct rw_semaphore *sem);
extern void up_read_non_owner(struct rw_semaphore *sem);
#else
# define down_read_nested(sem, subclass) down_read(sem)
# define down_write_nest_lock(sem, nest_lock) down_write(sem)
# define down_write_nested(sem, subclass) down_write(sem)
# define down_read_non_owner(sem) down_read(sem)
# define up_read_non_owner(sem) up_read(sem)
#endif
#endif /* _LINUX_RWSEM_H */

4
include/linux/sched.h
View file

@ -1411,6 +1411,10 @@ struct task_struct {
#ifdef CONFIG_UPROBES
struct uprobe_task *utask;
#endif
#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
unsigned int sequential_io;
unsigned int sequential_io_avg;
#endif
};
/* Future-safe accessor for struct task_struct's cpus_allowed. */

271
include/trace/events/bcache.h Normal file
View file

@ -0,0 +1,271 @@
#undef TRACE_SYSTEM
#define TRACE_SYSTEM bcache
#if !defined(_TRACE_BCACHE_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_BCACHE_H
#include <linux/tracepoint.h>
struct search;
DECLARE_EVENT_CLASS(bcache_request,
TP_PROTO(struct search *s, struct bio *bio),
TP_ARGS(s, bio),
TP_STRUCT__entry(
__field(dev_t, dev )
__field(unsigned int, orig_major )
__field(unsigned int, orig_minor )
__field(sector_t, sector )
__field(dev_t, orig_sector )
__field(unsigned int, nr_sector )
__array(char, rwbs, 6 )
__array(char, comm, TASK_COMM_LEN )
),
TP_fast_assign(
__entry->dev = bio->bi_bdev->bd_dev;
__entry->orig_major = s->d->disk->major;
__entry->orig_minor = s->d->disk->first_minor;
__entry->sector = bio->bi_sector;
__entry->orig_sector = bio->bi_sector - 16;
__entry->nr_sector = bio->bi_size >> 9;
blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),
TP_printk("%d,%d %s %llu + %u [%s] (from %d,%d @ %llu)",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->rwbs,
(unsigned long long)__entry->sector,
__entry->nr_sector, __entry->comm,
__entry->orig_major, __entry->orig_minor,
(unsigned long long)__entry->orig_sector)
);
DEFINE_EVENT(bcache_request, bcache_request_start,
TP_PROTO(struct search *s, struct bio *bio),
TP_ARGS(s, bio)
);
DEFINE_EVENT(bcache_request, bcache_request_end,
TP_PROTO(struct search *s, struct bio *bio),
TP_ARGS(s, bio)
);
DECLARE_EVENT_CLASS(bcache_bio,
TP_PROTO(struct bio *bio),
TP_ARGS(bio),
TP_STRUCT__entry(
__field(dev_t, dev )
__field(sector_t, sector )
__field(unsigned int, nr_sector )
__array(char, rwbs, 6 )
__array(char, comm, TASK_COMM_LEN )
),
TP_fast_assign(
__entry->dev = bio->bi_bdev->bd_dev;
__entry->sector = bio->bi_sector;
__entry->nr_sector = bio->bi_size >> 9;
blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),
TP_printk("%d,%d %s %llu + %u [%s]",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->rwbs,
(unsigned long long)__entry->sector,
__entry->nr_sector, __entry->comm)
);
DEFINE_EVENT(bcache_bio, bcache_passthrough,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_cache_hit,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_cache_miss,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_read_retry,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_writethrough,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_writeback,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_write_skip,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_btree_read,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_btree_write,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_write_dirty,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_read_dirty,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_write_moving,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_read_moving,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DEFINE_EVENT(bcache_bio, bcache_journal_write,
TP_PROTO(struct bio *bio),
TP_ARGS(bio)
);
DECLARE_EVENT_CLASS(bcache_cache_bio,
TP_PROTO(struct bio *bio,
sector_t orig_sector,
struct block_device* orig_bdev),
TP_ARGS(bio, orig_sector, orig_bdev),
TP_STRUCT__entry(
__field(dev_t, dev )
__field(dev_t, orig_dev )
__field(sector_t, sector )
__field(sector_t, orig_sector )
__field(unsigned int, nr_sector )
__array(char, rwbs, 6 )
__array(char, comm, TASK_COMM_LEN )
),
TP_fast_assign(
__entry->dev = bio->bi_bdev->bd_dev;
__entry->orig_dev = orig_bdev->bd_dev;
__entry->sector = bio->bi_sector;
__entry->orig_sector = orig_sector;
__entry->nr_sector = bio->bi_size >> 9;
blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),
TP_printk("%d,%d %s %llu + %u [%s] (from %d,%d %llu)",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->rwbs,
(unsigned long long)__entry->sector,
__entry->nr_sector, __entry->comm,
MAJOR(__entry->orig_dev), MINOR(__entry->orig_dev),
(unsigned long long)__entry->orig_sector)
);
DEFINE_EVENT(bcache_cache_bio, bcache_cache_insert,
TP_PROTO(struct bio *bio,
sector_t orig_sector,
struct block_device *orig_bdev),
TP_ARGS(bio, orig_sector, orig_bdev)
);
DECLARE_EVENT_CLASS(bcache_gc,
TP_PROTO(uint8_t *uuid),
TP_ARGS(uuid),
TP_STRUCT__entry(
__field(uint8_t *, uuid)
),
TP_fast_assign(
__entry->uuid = uuid;
),
TP_printk("%pU", __entry->uuid)
);
DEFINE_EVENT(bcache_gc, bcache_gc_start,
TP_PROTO(uint8_t *uuid),
TP_ARGS(uuid)
);
DEFINE_EVENT(bcache_gc, bcache_gc_end,
TP_PROTO(uint8_t *uuid),
TP_ARGS(uuid)
);
#endif /* _TRACE_BCACHE_H */
/* This part must be outside protection */
#include <trace/define_trace.h>

4
kernel/fork.c
View file

@ -1304,6 +1304,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->memcg_batch.do_batch = 0;
p->memcg_batch.memcg = NULL;
#endif
#ifdef CONFIG_BCACHE
p->sequential_io = 0;
p->sequential_io_avg = 0;
#endif
/* Perform scheduler related setup. Assign this task to a CPU. */
sched_fork(p);

1
kernel/lockdep.c
View file

@ -2998,6 +2998,7 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
EXPORT_SYMBOL_GPL(lockdep_init_map);
struct lock_class_key __lockdep_no_validate__;
EXPORT_SYMBOL_GPL(__lockdep_no_validate__);
static int
print_lock_nested_lock_not_held(struct task_struct *curr,

16
kernel/rwsem.c
View file

@ -126,6 +126,15 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest)
EXPORT_SYMBOL(_down_write_nest_lock);
void down_read_non_owner(struct rw_semaphore *sem)
{
might_sleep();
__down_read(sem);
}
EXPORT_SYMBOL(down_read_non_owner);
void down_write_nested(struct rw_semaphore *sem, int subclass)
{
might_sleep();
@ -136,6 +145,13 @@ void down_write_nested(struct rw_semaphore *sem, int subclass)
EXPORT_SYMBOL(down_write_nested);
void up_read_non_owner(struct rw_semaphore *sem)
{
__up_read(sem);
}
EXPORT_SYMBOL(up_read_non_owner);
#endif

1
kernel/trace/blktrace.c
View file

@ -1808,6 +1808,7 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
rwbs[i] = '\0';
}
EXPORT_SYMBOL_GPL(blk_fill_rwbs);
#endif /* CONFIG_EVENT_TRACING */

56
lib/lru_cache.c
View file

@ -365,7 +365,13 @@ static int lc_unused_element_available(struct lru_cache *lc)
return 0;
}
static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, bool may_change)
/* used as internal flags to __lc_get */
enum {
LC_GET_MAY_CHANGE = 1,
LC_GET_MAY_USE_UNCOMMITTED = 2,
};
static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, unsigned int flags)
{
struct lc_element *e;
@ -380,22 +386,31 @@ static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, bool
* this enr is currently being pulled in already,
* and will be available once the pending transaction
* has been committed. */
if (e && e->lc_new_number == e->lc_number) {
if (e) {
if (e->lc_new_number != e->lc_number) {
/* It has been found above, but on the "to_be_changed"
* list, not yet committed. Don't pull it in twice,
* wait for the transaction, then try again...
*/
if (!(flags & LC_GET_MAY_USE_UNCOMMITTED))
RETURN(NULL);
/* ... unless the caller is aware of the implications,
* probably preparing a cumulative transaction. */
++e->refcnt;
++lc->hits;
RETURN(e);
}
/* else: lc_new_number == lc_number; a real hit. */
++lc->hits;
if (e->refcnt++ == 0)
lc->used++;
list_move(&e->list, &lc->in_use); /* Not evictable... */
RETURN(e);
}
/* e == NULL */
++lc->misses;
if (!may_change)
RETURN(NULL);
/* It has been found above, but on the "to_be_changed" list, not yet
* committed. Don't pull it in twice, wait for the transaction, then
* try again */
if (e)
if (!(flags & LC_GET_MAY_CHANGE))
RETURN(NULL);
/* To avoid races with lc_try_lock(), first, mark us dirty
@ -477,7 +492,27 @@ static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, bool
*/
struct lc_element *lc_get(struct lru_cache *lc, unsigned int enr)
{
return __lc_get(lc, enr, 1);
return __lc_get(lc, enr, LC_GET_MAY_CHANGE);
}
/**
* lc_get_cumulative - like lc_get; also finds to-be-changed elements
* @lc: the lru cache to operate on
* @enr: the label to look up
*
* Unlike lc_get this also returns the element for @enr, if it is belonging to
* a pending transaction, so the return values are like for lc_get(),
* plus:
*
* pointer to an element already on the "to_be_changed" list.
* In this case, the cache was already marked %LC_DIRTY.
*
* Caller needs to make sure that the pending transaction is completed,
* before proceeding to actually use this element.
*/
struct lc_element *lc_get_cumulative(struct lru_cache *lc, unsigned int enr)
{
return __lc_get(lc, enr, LC_GET_MAY_CHANGE|LC_GET_MAY_USE_UNCOMMITTED);
}
/**
@ -648,3 +683,4 @@ EXPORT_SYMBOL(lc_seq_printf_stats);
EXPORT_SYMBOL(lc_seq_dump_details);
EXPORT_SYMBOL(lc_try_lock);
EXPORT_SYMBOL(lc_is_used);
EXPORT_SYMBOL(lc_get_cumulative);