linux-hardened/fs
Brian Foster 95808459b1 xfs: refactor xfs_buf_log_item reference count handling
The xfs_buf_log_item structure has a reference counter with slightly
tricky semantics. In the common case, a buffer is logged and
committed in a transaction, committed to the on-disk log (added to
the AIL) and then finally written back and removed from the AIL. The
bli refcount covers two potentially overlapping timeframes:

 1. the bli is held in an active transaction
 2. the bli is pinned by the log

The caveat to this approach is that the reference counter does not
purely dictate the lifetime of the bli. IOW, when a dirty buffer is
physically logged and unpinned, the bli refcount may go to zero as
the log item is inserted into the AIL. Only once the buffer is
written back can the bli finally be freed.

The above semantics means that it is not enough for the various
refcount decrementing contexts to release the bli on decrement to
zero. xfs_trans_brelse(), transaction commit (->iop_unlock()) and
unpin (->iop_unpin()) must all drop the associated reference and
make additional checks to determine if the current context is
responsible for freeing the item.

For example, if a transaction holds but does not dirty a particular
bli, the commit may drop the refcount to zero. If the bli itself is
clean, it is also not AIL resident and must be freed at this time.
The same is true for xfs_trans_brelse(). If the transaction dirties
a bli and then aborts or an unpin results in an abort due to a log
I/O error, the last reference count holder is expected to explicitly
remove the item from the AIL and release it (since an abort means
filesystem shutdown and metadata writeback will never occur).

This leads to fairly complex checks being replicated in a few
different places. Since ->iop_unlock() and xfs_trans_brelse() are
nearly identical, refactor the logic into a common helper that
implements and documents the semantics in one place. This patch does
not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29 13:45:26 +10:00
..
9p Pull request for inclusion in 4.19, take two 2018-08-17 17:27:58 -07:00
adfs adfs: use timespec64 for time conversion 2018-08-22 10:52:51 -07:00
affs affs: fix potential memory leak when parsing option 'prefix' 2018-05-28 12:36:41 +02:00
afs fs/afs: use new return type vm_fault_t 2018-08-23 18:48:43 -07:00
autofs Merge branch 'akpm' (patches from Andrew) 2018-08-22 12:34:08 -07:00
befs fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
bfs bfs_add_entry: pass name/len as qstr pointer 2018-05-22 14:27:50 -04:00
btrfs overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
cachefiles cachefiles: Wait rather than BUG'ing on "Unexpected object collision" 2018-07-25 14:49:00 +01:00
ceph The main things are support for cephx v2 authentication protocol and 2018-08-20 18:26:55 -07:00
cifs cifs: update internal module version number for cifs.ko to 2.12 2018-08-23 15:11:10 -05:00
coda vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
configfs configfs: fix registered group removal 2018-07-17 06:14:07 -07:00
cramfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
crypto f2fs-for-4.18-rc1 2018-06-11 10:16:13 -07:00
debugfs Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent" 2018-06-12 20:52:16 -07:00
devpts devpts: Convert to new IDA API 2018-08-21 23:54:17 -04:00
dlm treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
ecryptfs Merge branch 'fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into aio-base 2018-05-26 09:16:25 +02:00
efivarfs efivars: Call guid_parse() against guid_t type of variable 2018-07-22 14:13:44 +02:00
efs
exofs exofs: use bio_clone_fast in _write_mirror 2018-07-24 14:43:20 -06:00
exportfs ovl: do not try to reconnect a disconnected origin dentry 2018-04-12 12:04:49 +02:00
ext2 Merge branch 'akpm' (patches from Andrew) 2018-08-17 16:49:31 -07:00
ext4 ext4: readpages() should submit IO as read-ahead 2018-08-17 16:20:29 -07:00
f2fs f2fs-for-4.19-rc1 2018-08-22 13:29:39 -07:00
fat fat: propagate 64-bit inode timestamps 2018-08-22 10:52:50 -07:00
freevxfs freevxfs_lookup(): use d_splice_alias() 2018-05-22 14:27:51 -04:00
fscache fscache: Fix reference overput in fscache_attach_object() error handling 2018-07-25 14:49:00 +01:00
fuse fuse update for 4.19 2018-08-21 18:47:36 -07:00
gfs2 gfs2 4.19 merge 2018-08-15 22:40:03 -07:00
hfs hfs: prevent crash on exit from failed search 2018-08-23 18:48:42 -07:00
hfsplus hfsplus: prevent crash on exit from failed search 2018-08-23 18:48:42 -07:00
hostfs vfs: discard ATTR_ATTR_FLAG 2018-08-17 16:20:28 -07:00
hpfs hpfs: remove unnecessary checks on the value of r when assigning error code 2018-08-25 12:42:33 -07:00
hugetlbfs mm: zero out the vma in vma_init() 2018-08-22 10:52:44 -07:00
isofs isofs: fix potential memory leak in mount option parsing 2018-04-16 09:47:41 +02:00
jbd2 jbd2: replace current_kernel_time64 with ktime equivalent 2018-07-29 15:51:47 -04:00
jffs2 jffs2: use unsigned 32-bit timstamps consistently 2018-07-18 16:44:01 +02:00
jfs Just one jfs patch for 4.19 2018-08-15 22:47:23 -07:00
kernfs Driver core patches for 4.19-rc1 2018-08-18 11:44:53 -07:00
lockd nfsd: fix leaked file lock with nfs exported overlayfs 2018-08-09 16:11:21 -04:00
minix minix_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
nfs NFS client updates for Linux 4.19 2018-08-23 16:03:58 -07:00
nfs_common net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
nfsd A mistake on my part caused me to tag my branch 6 commits too early, 2018-08-23 16:00:10 -07:00
nilfs2 fs/nilfs2/file.c: use new return type vm_fault_t 2018-08-22 10:52:49 -07:00
nls
notify Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-08-21 13:47:29 -07:00
ntfs ntfs: mft: remove VLA usage 2018-08-17 16:20:27 -07:00
ocfs2 overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
omfs omfs_lookup(): report IO errors, use d_splice_alias() 2018-05-22 14:27:58 -04:00
openpromfs openpromfs: switch to d_splice_alias() 2018-05-22 14:27:57 -04:00
orangefs orangefs: remove redundant pointer orangefs_inode 2018-08-14 12:07:14 -04:00
overlayfs ovl: set I_CREATING on inode being created 2018-08-22 13:15:25 -07:00
proc Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-26 11:25:21 -07:00
pstore pstore: add zstd compression support 2018-08-03 18:12:18 -07:00
qnx4 qnx4_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
qnx6 qnx6_lookup: switch to d_splice_alias() 2018-05-22 14:27:54 -04:00
quota quota: Cleanup list iteration in dqcache_shrink_scan() 2018-06-20 11:04:26 +02:00
ramfs
reiserfs reiserfs: fix broken xattr handling (heap corruption, bad retval) 2018-08-22 10:52:50 -07:00
romfs romfs_lookup: switch to d_splice_alias() 2018-05-22 14:27:55 -04:00
squashfs Squashfs: Compute expected length from inode size rather than block length 2018-08-02 09:34:02 -07:00
sysfs Driver core patches for 4.19-rc1 2018-08-18 11:44:53 -07:00
sysv fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp 2018-08-22 10:52:51 -07:00
tracefs tracefs: Annotate tracefs_ops with __ro_after_init 2018-07-31 11:32:44 -04:00
ubifs ubifs: Remove empty file.h 2018-08-24 13:50:07 +02:00
udf \n 2018-08-17 09:38:39 -07:00
ufs fs/ufs: use ktime_get_real_seconds for sb and cg timestamps 2018-08-17 16:20:27 -07:00
xfs xfs: refactor xfs_buf_log_item reference count handling 2018-09-29 13:45:26 +10:00
aio.c Merge branch 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-08-13 20:56:23 -07:00
anon_inodes.c anon_inode_getfile(): switch to alloc_file_pseudo() 2018-07-12 10:04:27 -04:00
attr.c fs: Fix attr.c kernel-doc 2018-07-03 16:44:45 -04:00
bad_inode.c get rid of 'opened' argument of ->atomic_open() - part 3 2018-07-12 10:04:20 -04:00
binfmt_aout.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_elf.c Here are the main MIPS changes for 4.19. 2018-08-13 19:24:32 -07:00
binfmt_elf_fdpic.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
binfmt_em86.c
binfmt_flat.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_misc.c turn filp_clone_open() into inline wrapper for dentry_open() 2018-07-10 23:29:03 -04:00
binfmt_script.c
block_dev.c for-4.19/block-20180812 2018-08-14 10:23:25 -07:00
buffer.c fs, mm: account buffer_head to kmemcg 2018-08-17 16:20:30 -07:00
char_dev.c block, char_dev: Use correct format specifier for unsigned ints 2018-03-15 17:59:24 +01:00
compat.c ncpfs: remove compat functionality 2018-06-05 19:23:26 +02:00
compat_binfmt_elf.c
compat_ioctl.c media: dvb/audio.h: get rid of unused APIs 2018-07-30 16:21:49 -04:00
coredump.c
d_path.c split d_path() and friends into a separate file 2018-03-29 15:07:46 -04:00
dax.c libnvdimm-for-4.19_dax-memory-failure 2018-08-25 18:43:59 -07:00
dcache.c fs/dcache.c: fix kmemcheck splat at take_dentry_name_snapshot() 2018-08-17 16:20:28 -07:00
dcookies.c fs: add do_lookup_dcookie() helper; remove in-kernel call to syscall 2018-04-02 20:15:39 +02:00
direct-io.c block: consistently use GFP_NOIO instead of __GFP_NORECLAIM 2018-05-14 08:55:18 -06:00
drop_caches.c
eventfd.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
eventpoll.c fs/eventpoll.c: simplify ep_is_linked() callers 2018-08-22 10:52:49 -07:00
exec.c Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-08-21 13:47:29 -07:00
fcntl.c signal: Don't send signals to tasks that don't exist 2018-08-15 23:03:20 -05:00
fhandle.c
file.c fs: add ksys_close() wrapper; remove in-kernel calls to sys_close() 2018-04-02 20:16:00 +02:00
file_table.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
filesystems.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
fs-writeback.c bdi: Fix oops in wb_workfn() 2018-05-03 16:11:37 -06:00
fs_pin.c
fs_struct.c
inode.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
internal.h overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
ioctl.c vfs: export vfs_ioctl() to modules 2018-07-18 15:44:40 +02:00
iomap.c Changes since last update: 2018-08-21 18:15:47 -07:00
Kconfig autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
Kconfig.binfmt kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
libfs.c fs, dax: prepare for dax-specific address_space_operations 2018-03-30 11:34:55 -07:00
locks.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
Makefile autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
mbcache.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
mount.h
mpage.c mpage: mpage_readpages() should submit IO as read-ahead 2018-08-17 16:20:29 -07:00
namei.c namei: allow restricted O_CREAT of FIFOs and regular files 2018-08-23 18:48:43 -07:00
namespace.c Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax 2018-08-26 11:48:42 -07:00
no-block.c
nsfs.c net: Export open_related_ns() 2018-02-15 15:34:42 -05:00
open.c overlayfs update for 4.19 2018-08-21 18:19:09 -07:00
pipe.c Merge branch 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-08-13 19:58:36 -07:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
read_write.c vfs: export vfs_dedupe_file_range_one() to modules 2018-07-18 15:44:40 +02:00
readdir.c fs: add ksys_getdents64() helper; remove in-kernel calls to sys_getdents64() 2018-04-02 20:16:02 +02:00
select.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
seq_file.c fs/seq_file.c: simplify seq_file iteration code and interface 2018-08-17 16:20:28 -07:00
signalfd.c Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:21:50 +09:00
splice.c Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:21:50 +09:00
stack.c
stat.c fs: add do_readlinkat() helper; remove internal call to sys_readlinkat() 2018-04-02 20:15:34 +02:00
statfs.c kernel: add kcompat_sys_{f,}statfs64() 2018-07-12 14:49:48 +01:00
super.c Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax 2018-08-26 11:48:42 -07:00
sync.c Changes for this release: 2018-04-04 12:44:02 -07:00
timerfd.c Merge branch 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-08-13 20:56:23 -07:00
userfaultfd.c mm: Change return type int to vm_fault_t for fault handlers 2018-08-23 18:48:44 -07:00
utimes.c fs: add do_compat_futimesat() helper; remove in-kernel call to compat syscall 2018-04-02 20:15:44 +02:00
xattr.c Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-08-24 09:25:39 -07:00