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linux-hardened/fs/btrfs/tree-log.c
Josef Bacik 8c6c592831 btrfs: log csums for all modified extents 
Amir reported a bug discovered by his cleaned up version of my
dm-log-writes xfstests where we were missing csums at certain replay
points.  This is because fsx was doing an msync(), which essentially
fsync()'s a specific range of a file.  We will log all modified extents,
but only search for the checksums in the range we are being asked to
sync.  We cannot simply log the extents in the range we're being asked
because we are logging the inode item as it is currently, which if it
has had a i_size update before the msync means we will miss extents when
replaying.  We could possibly get around this by marking the inode with
the transaction that extended the i_size to see if we have this case,
but this would be racy and we'd have to lock the whole range of the
inode to make sure we didn't have an ordered extent outside of our range
that was in the middle of completing.

Fix this simply by keeping track of the modified extents range and
logging the csums for the entire range of extents that we are logging.
This makes the xfstest pass.

Reported-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-26 14:54:16 +02:00

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/*
* Copyright (C) 2008 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/list_sort.h>
#include "tree-log.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "backref.h"
#include "hash.h"
#include "compression.h"
#include "qgroup.h"
/* magic values for the inode_only field in btrfs_log_inode:
*
* LOG_INODE_ALL means to log everything
* LOG_INODE_EXISTS means to log just enough to recreate the inode
* during log replay
*/
#define LOG_INODE_ALL 0
#define LOG_INODE_EXISTS 1
#define LOG_OTHER_INODE 2
/*
* directory trouble cases
*
* 1) on rename or unlink, if the inode being unlinked isn't in the fsync
* log, we must force a full commit before doing an fsync of the directory
* where the unlink was done.
* ---> record transid of last unlink/rename per directory
*
* mkdir foo/some_dir
* normal commit
* rename foo/some_dir foo2/some_dir
* mkdir foo/some_dir
* fsync foo/some_dir/some_file
*
* The fsync above will unlink the original some_dir without recording
* it in its new location (foo2). After a crash, some_dir will be gone
* unless the fsync of some_file forces a full commit
*
* 2) we must log any new names for any file or dir that is in the fsync
* log. ---> check inode while renaming/linking.
*
* 2a) we must log any new names for any file or dir during rename
* when the directory they are being removed from was logged.
* ---> check inode and old parent dir during rename
*
* 2a is actually the more important variant. With the extra logging
* a crash might unlink the old name without recreating the new one
*
* 3) after a crash, we must go through any directories with a link count
* of zero and redo the rm -rf
*
* mkdir f1/foo
* normal commit
* rm -rf f1/foo
* fsync(f1)
*
* The directory f1 was fully removed from the FS, but fsync was never
* called on f1, only its parent dir. After a crash the rm -rf must
* be replayed. This must be able to recurse down the entire
* directory tree. The inode link count fixup code takes care of the
* ugly details.
*/
/*
* stages for the tree walking. The first
* stage (0) is to only pin down the blocks we find
* the second stage (1) is to make sure that all the inodes
* we find in the log are created in the subvolume.
*
* The last stage is to deal with directories and links and extents
* and all the other fun semantics
*/
#define LOG_WALK_PIN_ONLY 0
#define LOG_WALK_REPLAY_INODES 1
#define LOG_WALK_REPLAY_DIR_INDEX 2
#define LOG_WALK_REPLAY_ALL 3
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
int inode_only,
const loff_t start,
const loff_t end,
struct btrfs_log_ctx *ctx);
static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid);
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all);
/*
* tree logging is a special write ahead log used to make sure that
* fsyncs and O_SYNCs can happen without doing full tree commits.
*
* Full tree commits are expensive because they require commonly
* modified blocks to be recowed, creating many dirty pages in the
* extent tree an 4x-6x higher write load than ext3.
*
* Instead of doing a tree commit on every fsync, we use the
* key ranges and transaction ids to find items for a given file or directory
* that have changed in this transaction. Those items are copied into
* a special tree (one per subvolume root), that tree is written to disk
* and then the fsync is considered complete.
*
* After a crash, items are copied out of the log-tree back into the
* subvolume tree. Any file data extents found are recorded in the extent
* allocation tree, and the log-tree freed.
*
* The log tree is read three times, once to pin down all the extents it is
* using in ram and once, once to create all the inodes logged in the tree
* and once to do all the other items.
*/
/*
* start a sub transaction and setup the log tree
* this increments the log tree writer count to make the people
* syncing the tree wait for us to finish
*/
static int start_log_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
mutex_lock(&root->log_mutex);
if (root->log_root) {
if (btrfs_need_log_full_commit(fs_info, trans)) {
ret = -EAGAIN;
goto out;
}
if (!root->log_start_pid) {
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
} else if (root->log_start_pid != current->pid) {
set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
}
} else {
mutex_lock(&fs_info->tree_log_mutex);
if (!fs_info->log_root_tree)
ret = btrfs_init_log_root_tree(trans, fs_info);
mutex_unlock(&fs_info->tree_log_mutex);
if (ret)
goto out;
ret = btrfs_add_log_tree(trans, root);
if (ret)
goto out;
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
}
atomic_inc(&root->log_batch);
atomic_inc(&root->log_writers);
if (ctx) {
int index = root->log_transid % 2;
list_add_tail(&ctx->list, &root->log_ctxs[index]);
ctx->log_transid = root->log_transid;
}
out:
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* returns 0 if there was a log transaction running and we were able
* to join, or returns -ENOENT if there were not transactions
* in progress
*/
static int join_running_log_trans(struct btrfs_root *root)
{
int ret = -ENOENT;
smp_mb();
if (!root->log_root)
return -ENOENT;
mutex_lock(&root->log_mutex);
if (root->log_root) {
ret = 0;
atomic_inc(&root->log_writers);
}
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* This either makes the current running log transaction wait
* until you call btrfs_end_log_trans() or it makes any future
* log transactions wait until you call btrfs_end_log_trans()
*/
int btrfs_pin_log_trans(struct btrfs_root *root)
{
int ret = -ENOENT;
mutex_lock(&root->log_mutex);
atomic_inc(&root->log_writers);
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* indicate we're done making changes to the log tree
* and wake up anyone waiting to do a sync
*/
void btrfs_end_log_trans(struct btrfs_root *root)
{
if (atomic_dec_and_test(&root->log_writers)) {
/*
* Implicit memory barrier after atomic_dec_and_test
*/
if (waitqueue_active(&root->log_writer_wait))
wake_up(&root->log_writer_wait);
}
}
/*
* the walk control struct is used to pass state down the chain when
* processing the log tree. The stage field tells us which part
* of the log tree processing we are currently doing. The others
* are state fields used for that specific part
*/
struct walk_control {
/* should we free the extent on disk when done? This is used
* at transaction commit time while freeing a log tree
*/
int free;
/* should we write out the extent buffer? This is used
* while flushing the log tree to disk during a sync
*/
int write;
/* should we wait for the extent buffer io to finish? Also used
* while flushing the log tree to disk for a sync
*/
int wait;
/* pin only walk, we record which extents on disk belong to the
* log trees
*/
int pin;
/* what stage of the replay code we're currently in */
int stage;
/* the root we are currently replaying */
struct btrfs_root *replay_dest;
/* the trans handle for the current replay */
struct btrfs_trans_handle *trans;
/* the function that gets used to process blocks we find in the
* tree. Note the extent_buffer might not be up to date when it is
* passed in, and it must be checked or read if you need the data
* inside it
*/
int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen);
};
/*
* process_func used to pin down extents, write them or wait on them
*/
static int process_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
struct walk_control *wc, u64 gen)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
/*
* If this fs is mixed then we need to be able to process the leaves to
* pin down any logged extents, so we have to read the block.
*/
if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
ret = btrfs_read_buffer(eb, gen);
if (ret)
return ret;
}
if (wc->pin)
ret = btrfs_pin_extent_for_log_replay(fs_info, eb->start,
eb->len);
if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
if (wc->pin && btrfs_header_level(eb) == 0)
ret = btrfs_exclude_logged_extents(fs_info, eb);
if (wc->write)
btrfs_write_tree_block(eb);
if (wc->wait)
btrfs_wait_tree_block_writeback(eb);
}
return ret;
}
/*
* Item overwrite used by replay and tree logging. eb, slot and key all refer
* to the src data we are copying out.
*
* root is the tree we are copying into, and path is a scratch
* path for use in this function (it should be released on entry and
* will be released on exit).
*
* If the key is already in the destination tree the existing item is
* overwritten. If the existing item isn't big enough, it is extended.
* If it is too large, it is truncated.
*
* If the key isn't in the destination yet, a new item is inserted.
*/
static noinline int overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
u32 item_size;
u64 saved_i_size = 0;
int save_old_i_size = 0;
unsigned long src_ptr;
unsigned long dst_ptr;
int overwrite_root = 0;
bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
overwrite_root = 1;
item_size = btrfs_item_size_nr(eb, slot);
src_ptr = btrfs_item_ptr_offset(eb, slot);
/* look for the key in the destination tree */
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
return ret;
if (ret == 0) {
char *src_copy;
char *dst_copy;
u32 dst_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
if (dst_size != item_size)
goto insert;
if (item_size == 0) {
btrfs_release_path(path);
return 0;
}
dst_copy = kmalloc(item_size, GFP_NOFS);
src_copy = kmalloc(item_size, GFP_NOFS);
if (!dst_copy || !src_copy) {
btrfs_release_path(path);
kfree(dst_copy);
kfree(src_copy);
return -ENOMEM;
}
read_extent_buffer(eb, src_copy, src_ptr, item_size);
dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
item_size);
ret = memcmp(dst_copy, src_copy, item_size);
kfree(dst_copy);
kfree(src_copy);
/*
* they have the same contents, just return, this saves
* us from cowing blocks in the destination tree and doing
* extra writes that may not have been done by a previous
* sync
*/
if (ret == 0) {
btrfs_release_path(path);
return 0;
}
/*
* We need to load the old nbytes into the inode so when we
* replay the extents we've logged we get the right nbytes.
*/
if (inode_item) {
struct btrfs_inode_item *item;
u64 nbytes;
u32 mode;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
nbytes = btrfs_inode_nbytes(path->nodes[0], item);
item = btrfs_item_ptr(eb, slot,
struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, nbytes);
/*
* If this is a directory we need to reset the i_size to
* 0 so that we can set it up properly when replaying
* the rest of the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
} else if (inode_item) {
struct btrfs_inode_item *item;
u32 mode;
/*
* New inode, set nbytes to 0 so that the nbytes comes out
* properly when we replay the extents.
*/
item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, 0);
/*
* If this is a directory we need to reset the i_size to 0 so
* that we can set it up properly when replaying the rest of
* the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
insert:
btrfs_release_path(path);
/* try to insert the key into the destination tree */
path->skip_release_on_error = 1;
ret = btrfs_insert_empty_item(trans, root, path,
key, item_size);
path->skip_release_on_error = 0;
/* make sure any existing item is the correct size */
if (ret == -EEXIST || ret == -EOVERFLOW) {
u32 found_size;
found_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
if (found_size > item_size)
btrfs_truncate_item(fs_info, path, item_size, 1);
else if (found_size < item_size)
btrfs_extend_item(fs_info, path,
item_size - found_size);
} else if (ret) {
return ret;
}
dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
/* don't overwrite an existing inode if the generation number
* was logged as zero. This is done when the tree logging code
* is just logging an inode to make sure it exists after recovery.
*
* Also, don't overwrite i_size on directories during replay.
* log replay inserts and removes directory items based on the
* state of the tree found in the subvolume, and i_size is modified
* as it goes
*/
if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
struct btrfs_inode_item *src_item;
struct btrfs_inode_item *dst_item;
src_item = (struct btrfs_inode_item *)src_ptr;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(eb, src_item) == 0) {
struct extent_buffer *dst_eb = path->nodes[0];
const u64 ino_size = btrfs_inode_size(eb, src_item);
/*
* For regular files an ino_size == 0 is used only when
* logging that an inode exists, as part of a directory
* fsync, and the inode wasn't fsynced before. In this
* case don't set the size of the inode in the fs/subvol
* tree, otherwise we would be throwing valid data away.
*/
if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
ino_size != 0) {
struct btrfs_map_token token;
btrfs_init_map_token(&token);
btrfs_set_token_inode_size(dst_eb, dst_item,
ino_size, &token);
}
goto no_copy;
}
if (overwrite_root &&
S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
save_old_i_size = 1;
saved_i_size = btrfs_inode_size(path->nodes[0],
dst_item);
}
}
copy_extent_buffer(path->nodes[0], eb, dst_ptr,
src_ptr, item_size);
if (save_old_i_size) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
}
/* make sure the generation is filled in */
if (key->type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
btrfs_set_inode_generation(path->nodes[0], dst_item,
trans->transid);
}
}
no_copy:
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
/*
* simple helper to read an inode off the disk from a given root
* This can only be called for subvolume roots and not for the log
*/
static noinline struct inode *read_one_inode(struct btrfs_root *root,
u64 objectid)
{
struct btrfs_key key;
struct inode *inode;
key.objectid = objectid;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
if (IS_ERR(inode)) {
inode = NULL;
} else if (is_bad_inode(inode)) {
iput(inode);
inode = NULL;
}
return inode;
}
/* replays a single extent in 'eb' at 'slot' with 'key' into the
* subvolume 'root'. path is released on entry and should be released
* on exit.
*
* extents in the log tree have not been allocated out of the extent
* tree yet. So, this completes the allocation, taking a reference
* as required if the extent already exists or creating a new extent
* if it isn't in the extent allocation tree yet.
*
* The extent is inserted into the file, dropping any existing extents
* from the file that overlap the new one.
*/
static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int found_type;
u64 extent_end;
u64 start = key->offset;
u64 nbytes = 0;
struct btrfs_file_extent_item *item;
struct inode *inode = NULL;
unsigned long size;
int ret = 0;
item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
nbytes = btrfs_file_extent_num_bytes(eb, item);
extent_end = start + nbytes;
/*
* We don't add to the inodes nbytes if we are prealloc or a
* hole.
*/
if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
nbytes = 0;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size = btrfs_file_extent_inline_len(eb, slot, item);
nbytes = btrfs_file_extent_ram_bytes(eb, item);
extent_end = ALIGN(start + size,
fs_info->sectorsize);
} else {
ret = 0;
goto out;
}
inode = read_one_inode(root, key->objectid);
if (!inode) {
ret = -EIO;
goto out;
}
/*
* first check to see if we already have this extent in the
* file. This must be done before the btrfs_drop_extents run
* so we don't try to drop this extent.
*/
ret = btrfs_lookup_file_extent(trans, root, path,
btrfs_ino(BTRFS_I(inode)), start, 0);
if (ret == 0 &&
(found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
struct btrfs_file_extent_item cmp1;
struct btrfs_file_extent_item cmp2;
struct btrfs_file_extent_item *existing;
struct extent_buffer *leaf;
leaf = path->nodes[0];
existing = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
read_extent_buffer(eb, &cmp1, (unsigned long)item,
sizeof(cmp1));
read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
sizeof(cmp2));
/*
* we already have a pointer to this exact extent,
* we don't have to do anything
*/
if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
btrfs_release_path(path);
goto out;
}
}
btrfs_release_path(path);
/* drop any overlapping extents */
ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1);
if (ret)
goto out;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 offset;
unsigned long dest_offset;
struct btrfs_key ins;
if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
btrfs_fs_incompat(fs_info, NO_HOLES))
goto update_inode;
ret = btrfs_insert_empty_item(trans, root, path, key,
sizeof(*item));
if (ret)
goto out;
dest_offset = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
copy_extent_buffer(path->nodes[0], eb, dest_offset,
(unsigned long)item, sizeof(*item));
ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
ins.type = BTRFS_EXTENT_ITEM_KEY;
offset = key->offset - btrfs_file_extent_offset(eb, item);
/*
* Manually record dirty extent, as here we did a shallow
* file extent item copy and skip normal backref update,
* but modifying extent tree all by ourselves.
* So need to manually record dirty extent for qgroup,
* as the owner of the file extent changed from log tree
* (doesn't affect qgroup) to fs/file tree(affects qgroup)
*/
ret = btrfs_qgroup_trace_extent(trans, fs_info,
btrfs_file_extent_disk_bytenr(eb, item),
btrfs_file_extent_disk_num_bytes(eb, item),
GFP_NOFS);
if (ret < 0)
goto out;
if (ins.objectid > 0) {
u64 csum_start;
u64 csum_end;
LIST_HEAD(ordered_sums);
/*
* is this extent already allocated in the extent
* allocation tree? If so, just add a reference
*/
ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
ins.offset);
if (ret == 0) {
ret = btrfs_inc_extent_ref(trans, fs_info,
ins.objectid, ins.offset,
0, root->root_key.objectid,
key->objectid, offset);
if (ret)
goto out;
} else {
/*
* insert the extent pointer in the extent
* allocation tree
*/
ret = btrfs_alloc_logged_file_extent(trans,
fs_info,
root->root_key.objectid,
key->objectid, offset, &ins);
if (ret)
goto out;
}
btrfs_release_path(path);
if (btrfs_file_extent_compression(eb, item)) {
csum_start = ins.objectid;
csum_end = csum_start + ins.offset;
} else {
csum_start = ins.objectid +
btrfs_file_extent_offset(eb, item);
csum_end = csum_start +
btrfs_file_extent_num_bytes(eb, item);
}
ret = btrfs_lookup_csums_range(root->log_root,
csum_start, csum_end - 1,
&ordered_sums, 0);
if (ret)
goto out;
/*
* Now delete all existing cums in the csum root that
* cover our range. We do this because we can have an
* extent that is completely referenced by one file
* extent item and partially referenced by another
* file extent item (like after using the clone or
* extent_same ioctls). In this case if we end up doing
* the replay of the one that partially references the
* extent first, and we do not do the csum deletion
* below, we can get 2 csum items in the csum tree that
* overlap each other. For example, imagine our log has
* the two following file extent items:
*
* key (257 EXTENT_DATA 409600)
* extent data disk byte 12845056 nr 102400
* extent data offset 20480 nr 20480 ram 102400
*
* key (257 EXTENT_DATA 819200)
* extent data disk byte 12845056 nr 102400
* extent data offset 0 nr 102400 ram 102400
*
* Where the second one fully references the 100K extent
* that starts at disk byte 12845056, and the log tree
* has a single csum item that covers the entire range
* of the extent:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
*
* After the first file extent item is replayed, the
* csum tree gets the following csum item:
*
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which covers the 20K sub-range starting at offset 20K
* of our extent. Now when we replay the second file
* extent item, if we do not delete existing csum items
* that cover any of its blocks, we end up getting two
* csum items in our csum tree that overlap each other:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which is a problem, because after this anyone trying
* to lookup up for the checksum of any block of our
* extent starting at an offset of 40K or higher, will
* end up looking at the second csum item only, which
* does not contain the checksum for any block starting
* at offset 40K or higher of our extent.
*/
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums;
sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = btrfs_del_csums(trans, fs_info,
sums->bytenr,
sums->len);
if (!ret)
ret = btrfs_csum_file_blocks(trans,
fs_info->csum_root, sums);
list_del(&sums->list);
kfree(sums);
}
if (ret)
goto out;
} else {
btrfs_release_path(path);
}
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
/* inline extents are easy, we just overwrite them */
ret = overwrite_item(trans, root, path, eb, slot, key);
if (ret)
goto out;
}
inode_add_bytes(inode, nbytes);
update_inode:
ret = btrfs_update_inode(trans, root, inode);
out:
if (inode)
iput(inode);
return ret;
}
/*
* when cleaning up conflicts between the directory names in the
* subvolume, directory names in the log and directory names in the
* inode back references, we may have to unlink inodes from directories.
*
* This is a helper function to do the unlink of a specific directory
* item
*/
static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_inode *dir,
struct btrfs_dir_item *di)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct inode *inode;
char *name;
int name_len;
struct extent_buffer *leaf;
struct btrfs_key location;
int ret;
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
name_len = btrfs_dir_name_len(leaf, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name)
return -ENOMEM;
read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
btrfs_release_path(path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
ret = -EIO;
goto out;
}
ret = link_to_fixup_dir(trans, root, path, location.objectid);
if (ret)
goto out;
ret = btrfs_unlink_inode(trans, root, dir, BTRFS_I(inode), name,
name_len);
if (ret)
goto out;
else
ret = btrfs_run_delayed_items(trans, fs_info);
out:
kfree(name);
iput(inode);
return ret;
}
/*
* helper function to see if a given name and sequence number found
* in an inode back reference are already in a directory and correctly
* point to this inode
*/
static noinline int inode_in_dir(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, u64 objectid, u64 index,
const char *name, int name_len)
{
struct btrfs_dir_item *di;
struct btrfs_key location;
int match = 0;
di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
index, name, name_len, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else
goto out;
btrfs_release_path(path);
di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else
goto out;
match = 1;
out:
btrfs_release_path(path);
return match;
}
/*
* helper function to check a log tree for a named back reference in
* an inode. This is used to decide if a back reference that is
* found in the subvolume conflicts with what we find in the log.
*
* inode backreferences may have multiple refs in a single item,
* during replay we process one reference at a time, and we don't
* want to delete valid links to a file from the subvolume if that
* link is also in the log.
*/
static noinline int backref_in_log(struct btrfs_root *log,
struct btrfs_key *key,
u64 ref_objectid,
const char *name, int namelen)
{
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
unsigned long ptr;
unsigned long ptr_end;
unsigned long name_ptr;
int found_name_len;
int item_size;
int ret;
int match = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
if (ret != 0)
goto out;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
if (btrfs_find_name_in_ext_backref(path, ref_objectid,
name, namelen, NULL))
match = 1;
goto out;
}
item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
ref = (struct btrfs_inode_ref *)ptr;
found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
if (found_name_len == namelen) {
name_ptr = (unsigned long)(ref + 1);
ret = memcmp_extent_buffer(path->nodes[0], name,
name_ptr, namelen);
if (ret == 0) {
match = 1;
goto out;
}
}
ptr = (unsigned long)(ref + 1) + found_name_len;
}
out:
btrfs_free_path(path);
return match;
}
static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_root *log_root,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
u64 inode_objectid, u64 parent_objectid,
u64 ref_index, char *name, int namelen,
int *search_done)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
char *victim_name;
int victim_name_len;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key search_key;
struct btrfs_inode_extref *extref;
again:
/* Search old style refs */
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = parent_objectid;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret == 0) {
struct btrfs_inode_ref *victim_ref;
unsigned long ptr;
unsigned long ptr_end;
leaf = path->nodes[0];
/* are we trying to overwrite a back ref for the root directory
* if so, just jump out, we're done
*/
if (search_key.objectid == search_key.offset)
return 1;
/* check all the names in this back reference to see
* if they are in the log. if so, we allow them to stay
* otherwise they must be unlinked as a conflict
*/
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
while (ptr < ptr_end) {
victim_ref = (struct btrfs_inode_ref *)ptr;
victim_name_len = btrfs_inode_ref_name_len(leaf,
victim_ref);
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name,
(unsigned long)(victim_ref + 1),
victim_name_len);
if (!backref_in_log(log_root, &search_key,
parent_objectid,
victim_name,
victim_name_len)) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = btrfs_unlink_inode(trans, root, dir, inode,
victim_name, victim_name_len);
kfree(victim_name);
if (ret)
return ret;
ret = btrfs_run_delayed_items(trans, fs_info);
if (ret)
return ret;
*search_done = 1;
goto again;
}
kfree(victim_name);
ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
}
/*
* NOTE: we have searched root tree and checked the
* corresponding ref, it does not need to check again.
*/
*search_done = 1;
}
btrfs_release_path(path);
/* Same search but for extended refs */
extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
inode_objectid, parent_objectid, 0,
0);
if (!IS_ERR_OR_NULL(extref)) {
u32 item_size;
u32 cur_offset = 0;
unsigned long base;
struct inode *victim_parent;
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
base = btrfs_item_ptr_offset(leaf, path->slots[0]);
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *)(base + cur_offset);
victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
goto next;
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
victim_name_len);
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(parent_objectid,
victim_name,
victim_name_len);
ret = 0;
if (!backref_in_log(log_root, &search_key,
parent_objectid, victim_name,
victim_name_len)) {
ret = -ENOENT;
victim_parent = read_one_inode(root,
parent_objectid);
if (victim_parent) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = btrfs_unlink_inode(trans, root,
BTRFS_I(victim_parent),
inode,
victim_name,
victim_name_len);
if (!ret)
ret = btrfs_run_delayed_items(
trans,
fs_info);
}
iput(victim_parent);
kfree(victim_name);
if (ret)
return ret;
*search_done = 1;
goto again;
}
kfree(victim_name);
next:
cur_offset += victim_name_len + sizeof(*extref);
}
*search_done = 1;
}
btrfs_release_path(path);
/* look for a conflicting sequence number */
di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
ref_index, name, namelen, 0);
if (di && !IS_ERR(di)) {
ret = drop_one_dir_item(trans, root, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
/* look for a conflicing name */
di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
name, namelen, 0);
if (di && !IS_ERR(di)) {
ret = drop_one_dir_item(trans, root, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
return 0;
}
static int extref_get_fields(struct extent_buffer *eb, int slot,
unsigned long ref_ptr, u32 *namelen, char **name,
u64 *index, u64 *parent_objectid)
{
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ref_ptr;
*namelen = btrfs_inode_extref_name_len(eb, extref);
if (!btrfs_is_name_len_valid(eb, slot, (unsigned long)&extref->name,
*namelen))
return -EIO;
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)&extref->name,
*namelen);
*index = btrfs_inode_extref_index(eb, extref);
if (parent_objectid)
*parent_objectid = btrfs_inode_extref_parent(eb, extref);
return 0;
}
static int ref_get_fields(struct extent_buffer *eb, int slot,
unsigned long ref_ptr, u32 *namelen, char **name,
u64 *index)
{
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ref_ptr;
*namelen = btrfs_inode_ref_name_len(eb, ref);
if (!btrfs_is_name_len_valid(eb, slot, (unsigned long)(ref + 1),
*namelen))
return -EIO;
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
*index = btrfs_inode_ref_index(eb, ref);
return 0;
}
/*
* replay one inode back reference item found in the log tree.
* eb, slot and key refer to the buffer and key found in the log tree.
* root is the destination we are replaying into, and path is for temp
* use by this function. (it should be released on return).
*/
static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct inode *dir = NULL;
struct inode *inode = NULL;
unsigned long ref_ptr;
unsigned long ref_end;
char *name = NULL;
int namelen;
int ret;
int search_done = 0;
int log_ref_ver = 0;
u64 parent_objectid;
u64 inode_objectid;
u64 ref_index = 0;
int ref_struct_size;
ref_ptr = btrfs_item_ptr_offset(eb, slot);
ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *r;
ref_struct_size = sizeof(struct btrfs_inode_extref);
log_ref_ver = 1;
r = (struct btrfs_inode_extref *)ref_ptr;
parent_objectid = btrfs_inode_extref_parent(eb, r);
} else {
ref_struct_size = sizeof(struct btrfs_inode_ref);
parent_objectid = key->offset;
}
inode_objectid = key->objectid;
/*
* it is possible that we didn't log all the parent directories
* for a given inode. If we don't find the dir, just don't
* copy the back ref in. The link count fixup code will take
* care of the rest
*/
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
inode = read_one_inode(root, inode_objectid);
if (!inode) {
ret = -EIO;
goto out;
}
while (ref_ptr < ref_end) {
if (log_ref_ver) {
ret = extref_get_fields(eb, slot, ref_ptr, &namelen,
&name, &ref_index, &parent_objectid);
/*
* parent object can change from one array
* item to another.
*/
if (!dir)
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
} else {
ret = ref_get_fields(eb, slot, ref_ptr, &namelen,
&name, &ref_index);
}
if (ret)
goto out;
/* if we already have a perfect match, we're done */
if (!inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
btrfs_ino(BTRFS_I(inode)), ref_index,
name, namelen)) {
/*
* look for a conflicting back reference in the
* metadata. if we find one we have to unlink that name
* of the file before we add our new link. Later on, we
* overwrite any existing back reference, and we don't
* want to create dangling pointers in the directory.
*/
if (!search_done) {
ret = __add_inode_ref(trans, root, path, log,
BTRFS_I(dir),
BTRFS_I(inode),
inode_objectid,
parent_objectid,
ref_index, name, namelen,
&search_done);
if (ret) {
if (ret == 1)
ret = 0;
goto out;
}
}
/* insert our name */
ret = btrfs_add_link(trans, BTRFS_I(dir),
BTRFS_I(inode),
name, namelen, 0, ref_index);
if (ret)
goto out;
btrfs_update_inode(trans, root, inode);
}
ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
kfree(name);
name = NULL;
if (log_ref_ver) {
iput(dir);
dir = NULL;
}
}
/* finally write the back reference in the inode */
ret = overwrite_item(trans, root, path, eb, slot, key);
out:
btrfs_release_path(path);
kfree(name);
iput(dir);
iput(inode);
return ret;
}
static int insert_orphan_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 ino)
{
int ret;
ret = btrfs_insert_orphan_item(trans, root, ino);
if (ret == -EEXIST)
ret = 0;
return ret;
}
static int count_inode_extrefs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret = 0;
int name_len;
unsigned int nlink = 0;
u32 item_size;
u32 cur_offset = 0;
u64 inode_objectid = btrfs_ino(inode);
u64 offset = 0;
unsigned long ptr;
struct btrfs_inode_extref *extref;
struct extent_buffer *leaf;
while (1) {
ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
&extref, &offset);
if (ret)
break;
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
cur_offset = 0;
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
name_len = btrfs_inode_extref_name_len(leaf, extref);
nlink++;
cur_offset += name_len + sizeof(*extref);
}
offset++;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret < 0 && ret != -ENOENT)
return ret;
return nlink;
}
static int count_inode_refs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
unsigned int nlink = 0;
unsigned long ptr;
unsigned long ptr_end;
int name_len;
u64 ino = btrfs_ino(inode);
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
process_slot:
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid != ino ||
key.type != BTRFS_INODE_REF_KEY)
break;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
while (ptr < ptr_end) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
name_len = btrfs_inode_ref_name_len(path->nodes[0],
ref);
ptr = (unsigned long)(ref + 1) + name_len;
nlink++;
}
if (key.offset == 0)
break;
if (path->slots[0] > 0) {
path->slots[0]--;
goto process_slot;
}
key.offset--;
btrfs_release_path(path);
}
btrfs_release_path(path);
return nlink;
}
/*
* There are a few corners where the link count of the file can't
* be properly maintained during replay. So, instead of adding
* lots of complexity to the log code, we just scan the backrefs
* for any file that has been through replay.
*
* The scan will update the link count on the inode to reflect the
* number of back refs found. If it goes down to zero, the iput
* will free the inode.
*/
static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_path *path;
int ret;
u64 nlink = 0;
u64 ino = btrfs_ino(BTRFS_I(inode));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = count_inode_refs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink = ret;
ret = count_inode_extrefs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink += ret;
ret = 0;
if (nlink != inode->i_nlink) {
set_nlink(inode, nlink);
btrfs_update_inode(trans, root, inode);
}
BTRFS_I(inode)->index_cnt = (u64)-1;
if (inode->i_nlink == 0) {
if (S_ISDIR(inode->i_mode)) {
ret = replay_dir_deletes(trans, root, NULL, path,
ino, 1);
if (ret)
goto out;
}
ret = insert_orphan_item(trans, root, ino);
}
out:
btrfs_free_path(path);
return ret;
}
static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
struct inode *inode;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
break;
if (ret == 1) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
ret = btrfs_del_item(trans, root, path);
if (ret)
goto out;
btrfs_release_path(path);
inode = read_one_inode(root, key.offset);
if (!inode)
return -EIO;
ret = fixup_inode_link_count(trans, root, inode);
iput(inode);
if (ret)
goto out;
/*
* fixup on a directory may create new entries,
* make sure we always look for the highset possible
* offset
*/
key.offset = (u64)-1;
}
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* record a given inode in the fixup dir so we can check its link
* count when replay is done. The link count is incremented here
* so the inode won't go away until we check it
*/
static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid)
{
struct btrfs_key key;
int ret = 0;
struct inode *inode;
inode = read_one_inode(root, objectid);
if (!inode)
return -EIO;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = objectid;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(path);
if (ret == 0) {
if (!inode->i_nlink)
set_nlink(inode, 1);
else
inc_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
} else if (ret == -EEXIST) {
ret = 0;
} else {
BUG(); /* Logic Error */
}
iput(inode);
return ret;
}
/*
* when replaying the log for a directory, we only insert names
* for inodes that actually exist. This means an fsync on a directory
* does not implicitly fsync all the new files in it
*/
static noinline int insert_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 dirid, u64 index,
char *name, int name_len,
struct btrfs_key *location)
{
struct inode *inode;
struct inode *dir;
int ret;
inode = read_one_inode(root, location->objectid);
if (!inode)
return -ENOENT;
dir = read_one_inode(root, dirid);
if (!dir) {
iput(inode);
return -EIO;
}
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
name_len, 1, index);
/* FIXME, put inode into FIXUP list */
iput(inode);
iput(dir);
return ret;
}
/*
* Return true if an inode reference exists in the log for the given name,
* inode and parent inode.
*/
static bool name_in_log_ref(struct btrfs_root *log_root,
const char *name, const int name_len,
const u64 dirid, const u64 ino)
{
struct btrfs_key search_key;
search_key.objectid = ino;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = dirid;
if (backref_in_log(log_root, &search_key, dirid, name, name_len))
return true;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(dirid, name, name_len);
if (backref_in_log(log_root, &search_key, dirid, name, name_len))
return true;
return false;
}
/*
* take a single entry in a log directory item and replay it into
* the subvolume.
*
* if a conflicting item exists in the subdirectory already,
* the inode it points to is unlinked and put into the link count
* fix up tree.
*
* If a name from the log points to a file or directory that does
* not exist in the FS, it is skipped. fsyncs on directories
* do not force down inodes inside that directory, just changes to the
* names or unlinks in a directory.
*
* Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
* non-existing inode) and 1 if the name was replayed.
*/
static noinline int replay_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb,
struct btrfs_dir_item *di,
struct btrfs_key *key)
{
char *name;
int name_len;
struct btrfs_dir_item *dst_di;
struct btrfs_key found_key;
struct btrfs_key log_key;
struct inode *dir;
u8 log_type;
int exists;
int ret = 0;
bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
bool name_added = false;
dir = read_one_inode(root, key->objectid);
if (!dir)
return -EIO;
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
log_type = btrfs_dir_type(eb, di);
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
btrfs_dir_item_key_to_cpu(eb, di, &log_key);
exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
if (exists == 0)
exists = 1;
else
exists = 0;
btrfs_release_path(path);
if (key->type == BTRFS_DIR_ITEM_KEY) {
dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
name, name_len, 1);
} else if (key->type == BTRFS_DIR_INDEX_KEY) {
dst_di = btrfs_lookup_dir_index_item(trans, root, path,
key->objectid,
key->offset, name,
name_len, 1);
} else {
/* Corruption */
ret = -EINVAL;
goto out;
}
if (IS_ERR_OR_NULL(dst_di)) {
/* we need a sequence number to insert, so we only
* do inserts for the BTRFS_DIR_INDEX_KEY types
*/
if (key->type != BTRFS_DIR_INDEX_KEY)
goto out;
goto insert;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
/* the existing item matches the logged item */
if (found_key.objectid == log_key.objectid &&
found_key.type == log_key.type &&
found_key.offset == log_key.offset &&
btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
update_size = false;
goto out;
}
/*
* don't drop the conflicting directory entry if the inode
* for the new entry doesn't exist
*/
if (!exists)
goto out;
ret = drop_one_dir_item(trans, root, path, BTRFS_I(dir), dst_di);
if (ret)
goto out;
if (key->type == BTRFS_DIR_INDEX_KEY)
goto insert;
out:
btrfs_release_path(path);
if (!ret && update_size) {
btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2);
ret = btrfs_update_inode(trans, root, dir);
}
kfree(name);
iput(dir);
if (!ret && name_added)
ret = 1;
return ret;
insert:
if (name_in_log_ref(root->log_root, name, name_len,
key->objectid, log_key.objectid)) {
/* The dentry will be added later. */
ret = 0;
update_size = false;
goto out;
}
btrfs_release_path(path);
ret = insert_one_name(trans, root, key->objectid, key->offset,
name, name_len, &log_key);
if (ret && ret != -ENOENT && ret != -EEXIST)
goto out;
if (!ret)
name_added = true;
update_size = false;
ret = 0;
goto out;
}
/*
* find all the names in a directory item and reconcile them into
* the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
* one name in a directory item, but the same code gets used for
* both directory index types
*/
static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
u32 item_size = btrfs_item_size_nr(eb, slot);
struct btrfs_dir_item *di;
int name_len;
unsigned long ptr;
unsigned long ptr_end;
struct btrfs_path *fixup_path = NULL;
ptr = btrfs_item_ptr_offset(eb, slot);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
di = (struct btrfs_dir_item *)ptr;
if (verify_dir_item(fs_info, eb, slot, di))
return -EIO;
name_len = btrfs_dir_name_len(eb, di);
ret = replay_one_name(trans, root, path, eb, di, key);
if (ret < 0)
break;
ptr = (unsigned long)(di + 1);
ptr += name_len;
/*
* If this entry refers to a non-directory (directories can not
* have a link count > 1) and it was added in the transaction
* that was not committed, make sure we fixup the link count of
* the inode it the entry points to. Otherwise something like
* the following would result in a directory pointing to an
* inode with a wrong link that does not account for this dir
* entry:
*
* mkdir testdir
* touch testdir/foo
* touch testdir/bar
* sync
*
* ln testdir/bar testdir/bar_link
* ln testdir/foo testdir/foo_link
* xfs_io -c "fsync" testdir/bar
*
* <power failure>
*
* mount fs, log replay happens
*
* File foo would remain with a link count of 1 when it has two
* entries pointing to it in the directory testdir. This would
* make it impossible to ever delete the parent directory has
* it would result in stale dentries that can never be deleted.
*/
if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
struct btrfs_key di_key;
if (!fixup_path) {
fixup_path = btrfs_alloc_path();
if (!fixup_path) {
ret = -ENOMEM;
break;
}
}
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
ret = link_to_fixup_dir(trans, root, fixup_path,
di_key.objectid);
if (ret)
break;
}
ret = 0;
}
btrfs_free_path(fixup_path);
return ret;
}
/*
* directory replay has two parts. There are the standard directory
* items in the log copied from the subvolume, and range items
* created in the log while the subvolume was logged.
*
* The range items tell us which parts of the key space the log
* is authoritative for. During replay, if a key in the subvolume
* directory is in a logged range item, but not actually in the log
* that means it was deleted from the directory before the fsync
* and should be removed.
*/
static noinline int find_dir_range(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, int key_type,
u64 *start_ret, u64 *end_ret)
{
struct btrfs_key key;
u64 found_end;
struct btrfs_dir_log_item *item;
int ret;
int nritems;
if (*start_ret == (u64)-1)
return 1;
key.objectid = dirid;
key.type = key_type;
key.offset = *start_ret;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
if (ret != 0)
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != key_type || key.objectid != dirid) {
ret = 1;
goto next;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
if (*start_ret >= key.offset && *start_ret <= found_end) {
ret = 0;
*start_ret = key.offset;
*end_ret = found_end;
goto out;
}
ret = 1;
next:
/* check the next slot in the tree to see if it is a valid item */
nritems = btrfs_header_nritems(path->nodes[0]);
path->slots[0]++;
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != key_type || key.objectid != dirid) {
ret = 1;
goto out;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
*start_ret = key.offset;
*end_ret = found_end;
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* this looks for a given directory item in the log. If the directory
* item is not in the log, the item is removed and the inode it points
* to is unlinked
*/
static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_path *log_path,
struct inode *dir,
struct btrfs_key *dir_key)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
struct extent_buffer *eb;
int slot;
u32 item_size;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
int name_len;
unsigned long ptr;
unsigned long ptr_end;
char *name;
struct inode *inode;
struct btrfs_key location;
again:
eb = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(eb, slot);
ptr = btrfs_item_ptr_offset(eb, slot);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
di = (struct btrfs_dir_item *)ptr;
if (verify_dir_item(fs_info, eb, slot, di)) {
ret = -EIO;
goto out;
}
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
log_di = NULL;
if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
log_di = btrfs_lookup_dir_item(trans, log, log_path,
dir_key->objectid,
name, name_len, 0);
} else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
log_di = btrfs_lookup_dir_index_item(trans, log,
log_path,
dir_key->objectid,
dir_key->offset,
name, name_len, 0);
}
if (!log_di || (IS_ERR(log_di) && PTR_ERR(log_di) == -ENOENT)) {
btrfs_dir_item_key_to_cpu(eb, di, &location);
btrfs_release_path(path);
btrfs_release_path(log_path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
kfree(name);
return -EIO;
}
ret = link_to_fixup_dir(trans, root,
path, location.objectid);
if (ret) {
kfree(name);
iput(inode);
goto out;
}
inc_nlink(inode);
ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
BTRFS_I(inode), name, name_len);
if (!ret)
ret = btrfs_run_delayed_items(trans, fs_info);
kfree(name);
iput(inode);
if (ret)
goto out;
/* there might still be more names under this key
* check and repeat if required
*/
ret = btrfs_search_slot(NULL, root, dir_key, path,
0, 0);
if (ret == 0)
goto again;
ret = 0;
goto out;
} else if (IS_ERR(log_di)) {
kfree(name);
return PTR_ERR(log_di);
}
btrfs_release_path(log_path);
kfree(name);
ptr = (unsigned long)(di + 1);
ptr += name_len;
}
ret = 0;
out:
btrfs_release_path(path);
btrfs_release_path(log_path);
return ret;
}
static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
const u64 ino)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key search_key;
struct btrfs_path *log_path;
int i;
int nritems;
int ret;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_XATTR_ITEM_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
process_leaf:
nritems = btrfs_header_nritems(path->nodes[0]);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_key key;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
u32 total_size;
u32 cur;
btrfs_item_key_to_cpu(path->nodes[0], &key, i);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
ret = 0;
goto out;
}
di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
total_size = btrfs_item_size_nr(path->nodes[0], i);
cur = 0;
while (cur < total_size) {
u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
u32 this_len = sizeof(*di) + name_len + data_len;
char *name;
ret = verify_dir_item(fs_info, path->nodes[0], i, di);
if (ret) {
ret = -EIO;
goto out;
}
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(path->nodes[0], name,
(unsigned long)(di + 1), name_len);
log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
name, name_len, 0);
btrfs_release_path(log_path);
if (!log_di) {
/* Doesn't exist in log tree, so delete it. */
btrfs_release_path(path);
di = btrfs_lookup_xattr(trans, root, path, ino,
name, name_len, -1);
kfree(name);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
ASSERT(di);
ret = btrfs_delete_one_dir_name(trans, root,
path, di);
if (ret)
goto out;
btrfs_release_path(path);
search_key = key;
goto again;
}
kfree(name);
if (IS_ERR(log_di)) {
ret = PTR_ERR(log_di);
goto out;
}
cur += this_len;
di = (struct btrfs_dir_item *)((char *)di + this_len);
}
}
ret = btrfs_next_leaf(root, path);
if (ret > 0)
ret = 0;
else if (ret == 0)
goto process_leaf;
out:
btrfs_free_path(log_path);
btrfs_release_path(path);
return ret;
}
/*
* deletion replay happens before we copy any new directory items
* out of the log or out of backreferences from inodes. It
* scans the log to find ranges of keys that log is authoritative for,
* and then scans the directory to find items in those ranges that are
* not present in the log.
*
* Anything we don't find in the log is unlinked and removed from the
* directory.
*/
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all)
{
u64 range_start;
u64 range_end;
int key_type = BTRFS_DIR_LOG_ITEM_KEY;
int ret = 0;
struct btrfs_key dir_key;
struct btrfs_key found_key;
struct btrfs_path *log_path;
struct inode *dir;
dir_key.objectid = dirid;
dir_key.type = BTRFS_DIR_ITEM_KEY;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
dir = read_one_inode(root, dirid);
/* it isn't an error if the inode isn't there, that can happen
* because we replay the deletes before we copy in the inode item
* from the log
*/
if (!dir) {
btrfs_free_path(log_path);
return 0;
}
again:
range_start = 0;
range_end = 0;
while (1) {
if (del_all)
range_end = (u64)-1;
else {
ret = find_dir_range(log, path, dirid, key_type,
&range_start, &range_end);
if (ret != 0)
break;
}
dir_key.offset = range_start;
while (1) {
int nritems;
ret = btrfs_search_slot(NULL, root, &dir_key, path,
0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != dirid ||
found_key.type != dir_key.type)
goto next_type;
if (found_key.offset > range_end)
break;
ret = check_item_in_log(trans, root, log, path,
log_path, dir,
&found_key);
if (ret)
goto out;
if (found_key.offset == (u64)-1)
break;
dir_key.offset = found_key.offset + 1;
}
btrfs_release_path(path);
if (range_end == (u64)-1)
break;
range_start = range_end + 1;
}
next_type:
ret = 0;
if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
key_type = BTRFS_DIR_LOG_INDEX_KEY;
dir_key.type = BTRFS_DIR_INDEX_KEY;
btrfs_release_path(path);
goto again;
}
out:
btrfs_release_path(path);
btrfs_free_path(log_path);
iput(dir);
return ret;
}
/*
* the process_func used to replay items from the log tree. This
* gets called in two different stages. The first stage just looks
* for inodes and makes sure they are all copied into the subvolume.
*
* The second stage copies all the other item types from the log into
* the subvolume. The two stage approach is slower, but gets rid of
* lots of complexity around inodes referencing other inodes that exist
* only in the log (references come from either directory items or inode
* back refs).
*/
static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen)
{
int nritems;
struct btrfs_path *path;
struct btrfs_root *root = wc->replay_dest;
struct btrfs_key key;
int level;
int i;
int ret;
ret = btrfs_read_buffer(eb, gen);
if (ret)
return ret;
level = btrfs_header_level(eb);
if (level != 0)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
nritems = btrfs_header_nritems(eb);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
/* inode keys are done during the first stage */
if (key.type == BTRFS_INODE_ITEM_KEY &&
wc->stage == LOG_WALK_REPLAY_INODES) {
struct btrfs_inode_item *inode_item;
u32 mode;
inode_item = btrfs_item_ptr(eb, i,
struct btrfs_inode_item);
ret = replay_xattr_deletes(wc->trans, root, log,
path, key.objectid);
if (ret)
break;
mode = btrfs_inode_mode(eb, inode_item);
if (S_ISDIR(mode)) {
ret = replay_dir_deletes(wc->trans,
root, log, path, key.objectid, 0);
if (ret)
break;
}
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
/* for regular files, make sure corresponding
* orphan item exist. extents past the new EOF
* will be truncated later by orphan cleanup.
*/
if (S_ISREG(mode)) {
ret = insert_orphan_item(wc->trans, root,
key.objectid);
if (ret)
break;
}
ret = link_to_fixup_dir(wc->trans, root,
path, key.objectid);
if (ret)
break;
}
if (key.type == BTRFS_DIR_INDEX_KEY &&
wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
if (wc->stage < LOG_WALK_REPLAY_ALL)
continue;
/* these keys are simply copied */
if (key.type == BTRFS_XATTR_ITEM_KEY) {
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
} else if (key.type == BTRFS_INODE_REF_KEY ||
key.type == BTRFS_INODE_EXTREF_KEY) {
ret = add_inode_ref(wc->trans, root, log, path,
eb, i, &key);
if (ret && ret != -ENOENT)
break;
ret = 0;
} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
ret = replay_one_extent(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
} else if (key.type == BTRFS_DIR_ITEM_KEY) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
}
btrfs_free_path(path);
return ret;
}
static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 root_owner;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u32 blocksize;
int ret = 0;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
while (*level > 0) {
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
WARN_ON(btrfs_header_level(cur) != *level);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
blocksize = fs_info->nodesize;
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
next = btrfs_find_create_tree_block(fs_info, bytenr);
if (IS_ERR(next))
return PTR_ERR(next);
if (*level == 1) {
ret = wc->process_func(root, next, wc, ptr_gen);
if (ret) {
free_extent_buffer(next);
return ret;
}
path->slots[*level]++;
if (wc->free) {
ret = btrfs_read_buffer(next, ptr_gen);
if (ret) {
free_extent_buffer(next);
return ret;
}
if (trans) {
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
clean_tree_block(fs_info, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
}
WARN_ON(root_owner !=
BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_and_pin_reserved_extent(
fs_info, bytenr,
blocksize);
if (ret) {
free_extent_buffer(next);
return ret;
}
}
free_extent_buffer(next);
continue;
}
ret = btrfs_read_buffer(next, ptr_gen);
if (ret) {
free_extent_buffer(next);
return ret;
}
WARN_ON(*level <= 0);
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
cond_resched();
return 0;
}
static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 root_owner;
int i;
int slot;
int ret;
for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
return 0;
} else {
struct extent_buffer *parent;
if (path->nodes[*level] == root->node)
parent = path->nodes[*level];
else
parent = path->nodes[*level + 1];
root_owner = btrfs_header_owner(parent);
ret = wc->process_func(root, path->nodes[*level], wc,
btrfs_header_generation(path->nodes[*level]));
if (ret)
return ret;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[*level];
if (trans) {
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
clean_tree_block(fs_info, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
}
WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_and_pin_reserved_extent(
fs_info,
path->nodes[*level]->start,
path->nodes[*level]->len);
if (ret)
return ret;
}
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
static int walk_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int orig_level;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
level = btrfs_header_level(log->node);
orig_level = level;
path->nodes[level] = log->node;
extent_buffer_get(log->node);
path->slots[level] = 0;
while (1) {
wret = walk_down_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
wret = walk_up_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
}
/* was the root node processed? if not, catch it here */
if (path->nodes[orig_level]) {
ret = wc->process_func(log, path->nodes[orig_level], wc,
btrfs_header_generation(path->nodes[orig_level]));
if (ret)
goto out;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[orig_level];
if (trans) {
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
clean_tree_block(fs_info, next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
}
WARN_ON(log->root_key.objectid !=
BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_and_pin_reserved_extent(fs_info,
next->start, next->len);
if (ret)
goto out;
}
}
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function to update the item for a given subvolumes log root
* in the tree of log roots
*/
static int update_log_root(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret;
if (log->log_transid == 1) {
/* insert root item on the first sync */
ret = btrfs_insert_root(trans, fs_info->log_root_tree,
&log->root_key, &log->root_item);
} else {
ret = btrfs_update_root(trans, fs_info->log_root_tree,
&log->root_key, &log->root_item);
}
return ret;
}
static void wait_log_commit(struct btrfs_root *root, int transid)
{
DEFINE_WAIT(wait);
int index = transid % 2;
/*
* we only allow two pending log transactions at a time,
* so we know that if ours is more than 2 older than the
* current transaction, we're done
*/
do {
prepare_to_wait(&root->log_commit_wait[index],
&wait, TASK_UNINTERRUPTIBLE);
mutex_unlock(&root->log_mutex);
if (root->log_transid_committed < transid &&
atomic_read(&root->log_commit[index]))
schedule();
finish_wait(&root->log_commit_wait[index], &wait);
mutex_lock(&root->log_mutex);
} while (root->log_transid_committed < transid &&
atomic_read(&root->log_commit[index]));
}
static void wait_for_writer(struct btrfs_root *root)
{
DEFINE_WAIT(wait);
while (atomic_read(&root->log_writers)) {
prepare_to_wait(&root->log_writer_wait,
&wait, TASK_UNINTERRUPTIBLE);
mutex_unlock(&root->log_mutex);
if (atomic_read(&root->log_writers))
schedule();
finish_wait(&root->log_writer_wait, &wait);
mutex_lock(&root->log_mutex);
}
}
static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
if (!ctx)
return;
mutex_lock(&root->log_mutex);
list_del_init(&ctx->list);
mutex_unlock(&root->log_mutex);
}
/*
* Invoked in log mutex context, or be sure there is no other task which
* can access the list.
*/
static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
int index, int error)
{
struct btrfs_log_ctx *ctx;
struct btrfs_log_ctx *safe;
list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
list_del_init(&ctx->list);
ctx->log_ret = error;
}
INIT_LIST_HEAD(&root->log_ctxs[index]);
}
/*
* btrfs_sync_log does sends a given tree log down to the disk and
* updates the super blocks to record it. When this call is done,
* you know that any inodes previously logged are safely on disk only
* if it returns 0.
*
* Any other return value means you need to call btrfs_commit_transaction.
* Some of the edge cases for fsyncing directories that have had unlinks
* or renames done in the past mean that sometimes the only safe
* fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
* that has happened.
*/
int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_log_ctx *ctx)
{
int index1;
int index2;
int mark;
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *log = root->log_root;
struct btrfs_root *log_root_tree = fs_info->log_root_tree;
int log_transid = 0;
struct btrfs_log_ctx root_log_ctx;
struct blk_plug plug;
mutex_lock(&root->log_mutex);
log_transid = ctx->log_transid;
if (root->log_transid_committed >= log_transid) {
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
index1 = log_transid % 2;
if (atomic_read(&root->log_commit[index1])) {
wait_log_commit(root, log_transid);
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
ASSERT(log_transid == root->log_transid);
atomic_set(&root->log_commit[index1], 1);
/* wait for previous tree log sync to complete */
if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
wait_log_commit(root, log_transid - 1);
while (1) {
int batch = atomic_read(&root->log_batch);
/* when we're on an ssd, just kick the log commit out */
if (!btrfs_test_opt(fs_info, SSD) &&
test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
mutex_unlock(&root->log_mutex);
schedule_timeout_uninterruptible(1);
mutex_lock(&root->log_mutex);
}
wait_for_writer(root);
if (batch == atomic_read(&root->log_batch))
break;
}
/* bail out if we need to do a full commit */
if (btrfs_need_log_full_commit(fs_info, trans)) {
ret = -EAGAIN;
btrfs_free_logged_extents(log, log_transid);
mutex_unlock(&root->log_mutex);
goto out;
}
if (log_transid % 2 == 0)
mark = EXTENT_DIRTY;
else
mark = EXTENT_NEW;
/* we start IO on all the marked extents here, but we don't actually
* wait for them until later.
*/
blk_start_plug(&plug);
ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
if (ret) {
blk_finish_plug(&plug);
btrfs_abort_transaction(trans, ret);
btrfs_free_logged_extents(log, log_transid);
btrfs_set_log_full_commit(fs_info, trans);
mutex_unlock(&root->log_mutex);
goto out;
}
btrfs_set_root_node(&log->root_item, log->node);
root->log_transid++;
log->log_transid = root->log_transid;
root->log_start_pid = 0;
/*
* IO has been started, blocks of the log tree have WRITTEN flag set
* in their headers. new modifications of the log will be written to
* new positions. so it's safe to allow log writers to go in.
*/
mutex_unlock(&root->log_mutex);
btrfs_init_log_ctx(&root_log_ctx, NULL);
mutex_lock(&log_root_tree->log_mutex);
atomic_inc(&log_root_tree->log_batch);
atomic_inc(&log_root_tree->log_writers);
index2 = log_root_tree->log_transid % 2;
list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
root_log_ctx.log_transid = log_root_tree->log_transid;
mutex_unlock(&log_root_tree->log_mutex);
ret = update_log_root(trans, log);
mutex_lock(&log_root_tree->log_mutex);
if (atomic_dec_and_test(&log_root_tree->log_writers)) {
/*
* Implicit memory barrier after atomic_dec_and_test
*/
if (waitqueue_active(&log_root_tree->log_writer_wait))
wake_up(&log_root_tree->log_writer_wait);
}
if (ret) {
if (!list_empty(&root_log_ctx.list))
list_del_init(&root_log_ctx.list);
blk_finish_plug(&plug);
btrfs_set_log_full_commit(fs_info, trans);
if (ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out;
}
btrfs_wait_tree_log_extents(log, mark);
btrfs_free_logged_extents(log, log_transid);
mutex_unlock(&log_root_tree->log_mutex);
ret = -EAGAIN;
goto out;
}
if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
blk_finish_plug(&plug);
list_del_init(&root_log_ctx.list);
mutex_unlock(&log_root_tree->log_mutex);
ret = root_log_ctx.log_ret;
goto out;
}
index2 = root_log_ctx.log_transid % 2;
if (atomic_read(&log_root_tree->log_commit[index2])) {
blk_finish_plug(&plug);
ret = btrfs_wait_tree_log_extents(log, mark);
btrfs_wait_logged_extents(trans, log, log_transid);
wait_log_commit(log_root_tree,
root_log_ctx.log_transid);
mutex_unlock(&log_root_tree->log_mutex);
if (!ret)
ret = root_log_ctx.log_ret;
goto out;
}
ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
atomic_set(&log_root_tree->log_commit[index2], 1);
if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
wait_log_commit(log_root_tree,
root_log_ctx.log_transid - 1);
}
wait_for_writer(log_root_tree);
/*
* now that we've moved on to the tree of log tree roots,
* check the full commit flag again
*/
if (btrfs_need_log_full_commit(fs_info, trans)) {
blk_finish_plug(&plug);
btrfs_wait_tree_log_extents(log, mark);
btrfs_free_logged_extents(log, log_transid);
mutex_unlock(&log_root_tree->log_mutex);
ret = -EAGAIN;
goto out_wake_log_root;
}
ret = btrfs_write_marked_extents(fs_info,
&log_root_tree->dirty_log_pages,
EXTENT_DIRTY | EXTENT_NEW);
blk_finish_plug(&plug);
if (ret) {
btrfs_set_log_full_commit(fs_info, trans);
btrfs_abort_transaction(trans, ret);
btrfs_free_logged_extents(log, log_transid);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
ret = btrfs_wait_tree_log_extents(log, mark);
if (!ret)
ret = btrfs_wait_tree_log_extents(log_root_tree,
EXTENT_NEW | EXTENT_DIRTY);
if (ret) {
btrfs_set_log_full_commit(fs_info, trans);
btrfs_free_logged_extents(log, log_transid);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
btrfs_wait_logged_extents(trans, log, log_transid);
btrfs_set_super_log_root(fs_info->super_for_commit,
log_root_tree->node->start);
btrfs_set_super_log_root_level(fs_info->super_for_commit,
btrfs_header_level(log_root_tree->node));
log_root_tree->log_transid++;
mutex_unlock(&log_root_tree->log_mutex);
/*
* nobody else is going to jump in and write the the ctree
* super here because the log_commit atomic below is protecting
* us. We must be called with a transaction handle pinning
* the running transaction open, so a full commit can't hop
* in and cause problems either.
*/
ret = write_all_supers(fs_info, 1);
if (ret) {
btrfs_set_log_full_commit(fs_info, trans);
btrfs_abort_transaction(trans, ret);
goto out_wake_log_root;
}
mutex_lock(&root->log_mutex);
if (root->last_log_commit < log_transid)
root->last_log_commit = log_transid;
mutex_unlock(&root->log_mutex);
out_wake_log_root:
mutex_lock(&log_root_tree->log_mutex);
btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
log_root_tree->log_transid_committed++;
atomic_set(&log_root_tree->log_commit[index2], 0);
mutex_unlock(&log_root_tree->log_mutex);
/*
* The barrier before waitqueue_active is implied by mutex_unlock
*/
if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
wake_up(&log_root_tree->log_commit_wait[index2]);
out:
mutex_lock(&root->log_mutex);
btrfs_remove_all_log_ctxs(root, index1, ret);
root->log_transid_committed++;
atomic_set(&root->log_commit[index1], 0);
mutex_unlock(&root->log_mutex);
/*
* The barrier before waitqueue_active is implied by mutex_unlock
*/
if (waitqueue_active(&root->log_commit_wait[index1]))
wake_up(&root->log_commit_wait[index1]);
return ret;
}
static void free_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
int ret;
u64 start;
u64 end;
struct walk_control wc = {
.free = 1,
.process_func = process_one_buffer
};
ret = walk_log_tree(trans, log, &wc);
/* I don't think this can happen but just in case */
if (ret)
btrfs_abort_transaction(trans, ret);
while (1) {
ret = find_first_extent_bit(&log->dirty_log_pages,
0, &start, &end, EXTENT_DIRTY | EXTENT_NEW,
NULL);
if (ret)
break;
clear_extent_bits(&log->dirty_log_pages, start, end,
EXTENT_DIRTY | EXTENT_NEW);
}
/*
* We may have short-circuited the log tree with the full commit logic
* and left ordered extents on our list, so clear these out to keep us
* from leaking inodes and memory.
*/
btrfs_free_logged_extents(log, 0);
btrfs_free_logged_extents(log, 1);
free_extent_buffer(log->node);
kfree(log);
}
/*
* free all the extents used by the tree log. This should be called
* at commit time of the full transaction
*/
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
{
if (root->log_root) {
free_log_tree(trans, root->log_root);
root->log_root = NULL;
}
return 0;
}
int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
if (fs_info->log_root_tree) {
free_log_tree(trans, fs_info->log_root_tree);
fs_info->log_root_tree = NULL;
}
return 0;
}
/*
* If both a file and directory are logged, and unlinks or renames are
* mixed in, we have a few interesting corners:
*
* create file X in dir Y
* link file X to X.link in dir Y
* fsync file X
* unlink file X but leave X.link
* fsync dir Y
*
* After a crash we would expect only X.link to exist. But file X
* didn't get fsync'd again so the log has back refs for X and X.link.
*
* We solve this by removing directory entries and inode backrefs from the
* log when a file that was logged in the current transaction is
* unlinked. Any later fsync will include the updated log entries, and
* we'll be able to reconstruct the proper directory items from backrefs.
*
* This optimizations allows us to avoid relogging the entire inode
* or the entire directory.
*/
int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *dir, u64 index)
{
struct btrfs_root *log;
struct btrfs_dir_item *di;
struct btrfs_path *path;
int ret;
int err = 0;
int bytes_del = 0;
u64 dir_ino = btrfs_ino(dir);
if (dir->logged_trans < trans->transid)
return 0;
ret = join_running_log_trans(root);
if (ret)
return 0;
mutex_lock(&dir->log_mutex);
log = root->log_root;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out_unlock;
}
di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
name, name_len, -1);
if (IS_ERR(di)) {
err = PTR_ERR(di);
goto fail;
}
if (di) {
ret = btrfs_delete_one_dir_name(trans, log, path, di);
bytes_del += name_len;
if (ret) {
err = ret;
goto fail;
}
}
btrfs_release_path(path);
di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
index, name, name_len, -1);
if (IS_ERR(di)) {
err = PTR_ERR(di);
goto fail;
}
if (di) {
ret = btrfs_delete_one_dir_name(trans, log, path, di);
bytes_del += name_len;
if (ret) {
err = ret;
goto fail;
}
}
/* update the directory size in the log to reflect the names
* we have removed
*/
if (bytes_del) {
struct btrfs_key key;
key.objectid = dir_ino;
key.offset = 0;
key.type = BTRFS_INODE_ITEM_KEY;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (ret == 0) {
struct btrfs_inode_item *item;
u64 i_size;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
i_size = btrfs_inode_size(path->nodes[0], item);
if (i_size > bytes_del)
i_size -= bytes_del;
else
i_size = 0;
btrfs_set_inode_size(path->nodes[0], item, i_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
} else
ret = 0;
btrfs_release_path(path);
}
fail:
btrfs_free_path(path);
out_unlock:
mutex_unlock(&dir->log_mutex);
if (ret == -ENOSPC) {
btrfs_set_log_full_commit(root->fs_info, trans);
ret = 0;
} else if (ret < 0)
btrfs_abort_transaction(trans, ret);
btrfs_end_log_trans(root);
return err;
}
/* see comments for btrfs_del_dir_entries_in_log */
int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *inode, u64 dirid)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *log;
u64 index;
int ret;
if (inode->logged_trans < trans->transid)
return 0;
ret = join_running_log_trans(root);
if (ret)
return 0;
log = root->log_root;
mutex_lock(&inode->log_mutex);
ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
dirid, &index);
mutex_unlock(&inode->log_mutex);
if (ret == -ENOSPC) {
btrfs_set_log_full_commit(fs_info, trans);
ret = 0;
} else if (ret < 0 && ret != -ENOENT)
btrfs_abort_transaction(trans, ret);
btrfs_end_log_trans(root);
return ret;
}
/*
* creates a range item in the log for 'dirid'. first_offset and
* last_offset tell us which parts of the key space the log should
* be considered authoritative for.
*/
static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
int key_type, u64 dirid,
u64 first_offset, u64 last_offset)
{
int ret;
struct btrfs_key key;
struct btrfs_dir_log_item *item;
key.objectid = dirid;
key.offset = first_offset;
if (key_type == BTRFS_DIR_ITEM_KEY)
key.type = BTRFS_DIR_LOG_ITEM_KEY;
else
key.type = BTRFS_DIR_LOG_INDEX_KEY;
ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
if (ret)
return ret;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
/*
* log all the items included in the current transaction for a given
* directory. This also creates the range items in the log tree required
* to replay anything deleted before the fsync
*/
static noinline int log_dir_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path, int key_type,
struct btrfs_log_ctx *ctx,
u64 min_offset, u64 *last_offset_ret)
{
struct btrfs_key min_key;
struct btrfs_root *log = root->log_root;
struct extent_buffer *src;
int err = 0;
int ret;
int i;
int nritems;
u64 first_offset = min_offset;
u64 last_offset = (u64)-1;
u64 ino = btrfs_ino(inode);
log = root->log_root;
min_key.objectid = ino;
min_key.type = key_type;
min_key.offset = min_offset;
ret = btrfs_search_forward(root, &min_key, path, trans->transid);
/*
* we didn't find anything from this transaction, see if there
* is anything at all
*/
if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
min_key.objectid = ino;
min_key.type = key_type;
min_key.offset = (u64)-1;
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret < 0) {
btrfs_release_path(path);
return ret;
}
ret = btrfs_previous_item(root, path, ino, key_type);
/* if ret == 0 there are items for this type,
* create a range to tell us the last key of this type.
* otherwise, there are no items in this directory after
* *min_offset, and we create a range to indicate that.
*/
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp,
path->slots[0]);
if (key_type == tmp.type)
first_offset = max(min_offset, tmp.offset) + 1;
}
goto done;
}
/* go backward to find any previous key */
ret = btrfs_previous_item(root, path, ino, key_type);
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
if (key_type == tmp.type) {
first_offset = tmp.offset;
ret = overwrite_item(trans, log, dst_path,
path->nodes[0], path->slots[0],
&tmp);
if (ret) {
err = ret;
goto done;
}
}
}
btrfs_release_path(path);
/* find the first key from this transaction again */
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (WARN_ON(ret != 0))
goto done;
/*
* we have a block from this transaction, log every item in it
* from our directory
*/
while (1) {
struct btrfs_key tmp;
src = path->nodes[0];
nritems = btrfs_header_nritems(src);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
btrfs_item_key_to_cpu(src, &min_key, i);
if (min_key.objectid != ino || min_key.type != key_type)
goto done;
ret = overwrite_item(trans, log, dst_path, src, i,
&min_key);
if (ret) {
err = ret;
goto done;
}
/*
* We must make sure that when we log a directory entry,
* the corresponding inode, after log replay, has a
* matching link count. For example:
*
* touch foo
* mkdir mydir
* sync
* ln foo mydir/bar
* xfs_io -c "fsync" mydir
* <crash>
* <mount fs and log replay>
*
* Would result in a fsync log that when replayed, our
* file inode would have a link count of 1, but we get
* two directory entries pointing to the same inode.
* After removing one of the names, it would not be
* possible to remove the other name, which resulted
* always in stale file handle errors, and would not
* be possible to rmdir the parent directory, since
* its i_size could never decrement to the value
* BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors.
*/
di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
btrfs_dir_item_key_to_cpu(src, di, &tmp);
if (ctx &&
(btrfs_dir_transid(src, di) == trans->transid ||
btrfs_dir_type(src, di) == BTRFS_FT_DIR) &&
tmp.type != BTRFS_ROOT_ITEM_KEY)
ctx->log_new_dentries = true;
}
path->slots[0] = nritems;
/*
* look ahead to the next item and see if it is also
* from this directory and from this transaction
*/
ret = btrfs_next_leaf(root, path);
if (ret == 1) {
last_offset = (u64)-1;
goto done;
}
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
if (tmp.objectid != ino || tmp.type != key_type) {
last_offset = (u64)-1;
goto done;
}
if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
ret = overwrite_item(trans, log, dst_path,
path->nodes[0], path->slots[0],
&tmp);
if (ret)
err = ret;
else
last_offset = tmp.offset;
goto done;
}
}
done:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (err == 0) {
*last_offset_ret = last_offset;
/*
* insert the log range keys to indicate where the log
* is valid
*/
ret = insert_dir_log_key(trans, log, path, key_type,
ino, first_offset, last_offset);
if (ret)
err = ret;
}
return err;
}
/*
* logging directories is very similar to logging inodes, We find all the items
* from the current transaction and write them to the log.
*
* The recovery code scans the directory in the subvolume, and if it finds a
* key in the range logged that is not present in the log tree, then it means
* that dir entry was unlinked during the transaction.
*
* In order for that scan to work, we must include one key smaller than
* the smallest logged by this transaction and one key larger than the largest
* key logged by this transaction.
*/
static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx)
{
u64 min_key;
u64 max_key;
int ret;
int key_type = BTRFS_DIR_ITEM_KEY;
again:
min_key = 0;
max_key = 0;
while (1) {
ret = log_dir_items(trans, root, inode, path, dst_path, key_type,
ctx, min_key, &max_key);
if (ret)
return ret;
if (max_key == (u64)-1)
break;
min_key = max_key + 1;
}
if (key_type == BTRFS_DIR_ITEM_KEY) {
key_type = BTRFS_DIR_INDEX_KEY;
goto again;
}
return 0;
}
/*
* a helper function to drop items from the log before we relog an
* inode. max_key_type indicates the highest item type to remove.
* This cannot be run for file data extents because it does not
* free the extents they point to.
*/
static int drop_objectid_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 objectid, int max_key_type)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
int start_slot;
key.objectid = objectid;
key.type = max_key_type;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
BUG_ON(ret == 0); /* Logic error */
if (ret < 0)
break;
if (path->slots[0] == 0)
break;
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != objectid)
break;
found_key.offset = 0;
found_key.type = 0;
ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
&start_slot);
ret = btrfs_del_items(trans, log, path, start_slot,
path->slots[0] - start_slot + 1);
/*
* If start slot isn't 0 then we don't need to re-search, we've
* found the last guy with the objectid in this tree.
*/
if (ret || start_slot != 0)
break;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret > 0)
ret = 0;
return ret;
}
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode, int log_inode_only,
u64 logged_isize)
{
struct btrfs_map_token token;
btrfs_init_map_token(&token);
if (log_inode_only) {
/* set the generation to zero so the recover code
* can tell the difference between an logging
* just to say 'this inode exists' and a logging
* to say 'update this inode with these values'
*/
btrfs_set_token_inode_generation(leaf, item, 0, &token);
btrfs_set_token_inode_size(leaf, item, logged_isize, &token);
} else {
btrfs_set_token_inode_generation(leaf, item,
BTRFS_I(inode)->generation,
&token);
btrfs_set_token_inode_size(leaf, item, inode->i_size, &token);
}
btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
btrfs_set_token_timespec_sec(leaf, &item->atime,
inode->i_atime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->atime,
inode->i_atime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->mtime,
inode->i_mtime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->mtime,
inode->i_mtime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->ctime,
inode->i_ctime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->ctime,
inode->i_ctime.tv_nsec, &token);
btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
&token);
btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
btrfs_set_token_inode_block_group(leaf, item, 0, &token);
}
static int log_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct btrfs_path *path,
struct btrfs_inode *inode)
{
struct btrfs_inode_item *inode_item;
int ret;
ret = btrfs_insert_empty_item(trans, log, path,
&inode->location, sizeof(*inode_item));
if (ret && ret != -EEXIST)
return ret;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
0, 0);
btrfs_release_path(path);
return 0;
}
static noinline int copy_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *dst_path,
struct btrfs_path *src_path, u64 *last_extent,
int start_slot, int nr, int inode_only,
u64 logged_isize)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
unsigned long src_offset;
unsigned long dst_offset;
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item *extent;
struct btrfs_inode_item *inode_item;
struct extent_buffer *src = src_path->nodes[0];
struct btrfs_key first_key, last_key, key;
int ret;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
char *ins_data;
int i;
struct list_head ordered_sums;
int skip_csum = inode->flags & BTRFS_INODE_NODATASUM;
bool has_extents = false;
bool need_find_last_extent = true;
bool done = false;
INIT_LIST_HEAD(&ordered_sums);
ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
nr * sizeof(u32), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
first_key.objectid = (u64)-1;
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
for (i = 0; i < nr; i++) {
ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
}
ret = btrfs_insert_empty_items(trans, log, dst_path,
ins_keys, ins_sizes, nr);
if (ret) {
kfree(ins_data);
return ret;
}
for (i = 0; i < nr; i++, dst_path->slots[0]++) {
dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
dst_path->slots[0]);
src_offset = btrfs_item_ptr_offset(src, start_slot + i);
if (i == nr - 1)
last_key = ins_keys[i];
if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
inode_item = btrfs_item_ptr(dst_path->nodes[0],
dst_path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, dst_path->nodes[0], inode_item,
&inode->vfs_inode,
inode_only == LOG_INODE_EXISTS,
logged_isize);
} else {
copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
src_offset, ins_sizes[i]);
}
/*
* We set need_find_last_extent here in case we know we were
* processing other items and then walk into the first extent in
* the inode. If we don't hit an extent then nothing changes,
* we'll do the last search the next time around.
*/
if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY) {
has_extents = true;
if (first_key.objectid == (u64)-1)
first_key = ins_keys[i];
} else {
need_find_last_extent = false;
}
/* take a reference on file data extents so that truncates
* or deletes of this inode don't have to relog the inode
* again
*/
if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY &&
!skip_csum) {
int found_type;
extent = btrfs_item_ptr(src, start_slot + i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_generation(src, extent) < trans->transid)
continue;
found_type = btrfs_file_extent_type(src, extent);
if (found_type == BTRFS_FILE_EXTENT_REG) {
u64 ds, dl, cs, cl;
ds = btrfs_file_extent_disk_bytenr(src,
extent);
/* ds == 0 is a hole */
if (ds == 0)
continue;
dl = btrfs_file_extent_disk_num_bytes(src,
extent);
cs = btrfs_file_extent_offset(src, extent);
cl = btrfs_file_extent_num_bytes(src,
extent);
if (btrfs_file_extent_compression(src,
extent)) {
cs = 0;
cl = dl;
}
ret = btrfs_lookup_csums_range(
fs_info->csum_root,
ds + cs, ds + cs + cl - 1,
&ordered_sums, 0);
if (ret) {
btrfs_release_path(dst_path);
kfree(ins_data);
return ret;
}
}
}
}
btrfs_mark_buffer_dirty(dst_path->nodes[0]);
btrfs_release_path(dst_path);
kfree(ins_data);
/*
* we have to do this after the loop above to avoid changing the
* log tree while trying to change the log tree.
*/
ret = 0;
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = btrfs_csum_file_blocks(trans, log, sums);
list_del(&sums->list);
kfree(sums);
}
if (!has_extents)
return ret;
if (need_find_last_extent && *last_extent == first_key.offset) {
/*
* We don't have any leafs between our current one and the one
* we processed before that can have file extent items for our
* inode (and have a generation number smaller than our current
* transaction id).
*/
need_find_last_extent = false;
}
/*
* Because we use btrfs_search_forward we could skip leaves that were
* not modified and then assume *last_extent is valid when it really
* isn't. So back up to the previous leaf and read the end of the last
* extent before we go and fill in holes.
*/
if (need_find_last_extent) {
u64 len;
ret = btrfs_prev_leaf(inode->root, src_path);
if (ret < 0)
return ret;
if (ret)
goto fill_holes;
if (src_path->slots[0])
src_path->slots[0]--;
src = src_path->nodes[0];
btrfs_item_key_to_cpu(src, &key, src_path->slots[0]);
if (key.objectid != btrfs_ino(inode) ||
key.type != BTRFS_EXTENT_DATA_KEY)
goto fill_holes;
extent = btrfs_item_ptr(src, src_path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(src, extent) ==
BTRFS_FILE_EXTENT_INLINE) {
len = btrfs_file_extent_inline_len(src,
src_path->slots[0],
extent);
*last_extent = ALIGN(key.offset + len,
fs_info->sectorsize);
} else {
len = btrfs_file_extent_num_bytes(src, extent);
*last_extent = key.offset + len;
}
}
fill_holes:
/* So we did prev_leaf, now we need to move to the next leaf, but a few
* things could have happened
*
* 1) A merge could have happened, so we could currently be on a leaf
* that holds what we were copying in the first place.
* 2) A split could have happened, and now not all of the items we want
* are on the same leaf.
*
* So we need to adjust how we search for holes, we need to drop the
* path and re-search for the first extent key we found, and then walk
* forward until we hit the last one we copied.
*/
if (need_find_last_extent) {
/* btrfs_prev_leaf could return 1 without releasing the path */
btrfs_release_path(src_path);
ret = btrfs_search_slot(NULL, inode->root, &first_key,
src_path, 0, 0);
if (ret < 0)
return ret;
ASSERT(ret == 0);
src = src_path->nodes[0];
i = src_path->slots[0];
} else {
i = start_slot;
}
/*
* Ok so here we need to go through and fill in any holes we may have
* to make sure that holes are punched for those areas in case they had
* extents previously.
*/
while (!done) {
u64 offset, len;
u64 extent_end;
if (i >= btrfs_header_nritems(src_path->nodes[0])) {
ret = btrfs_next_leaf(inode->root, src_path);
if (ret < 0)
return ret;
ASSERT(ret == 0);
src = src_path->nodes[0];
i = 0;
}
btrfs_item_key_to_cpu(src, &key, i);
if (!btrfs_comp_cpu_keys(&key, &last_key))
done = true;
if (key.objectid != btrfs_ino(inode) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
i++;
continue;
}
extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(src, extent) ==
BTRFS_FILE_EXTENT_INLINE) {
len = btrfs_file_extent_inline_len(src, i, extent);
extent_end = ALIGN(key.offset + len,
fs_info->sectorsize);
} else {
len = btrfs_file_extent_num_bytes(src, extent);
extent_end = key.offset + len;
}
i++;
if (*last_extent == key.offset) {
*last_extent = extent_end;
continue;
}
offset = *last_extent;
len = key.offset - *last_extent;
ret = btrfs_insert_file_extent(trans, log, btrfs_ino(inode),
offset, 0, 0, len, 0, len, 0, 0, 0);
if (ret)
break;
*last_extent = extent_end;
}
/*
* Need to let the callers know we dropped the path so they should
* re-search.
*/
if (!ret && need_find_last_extent)
ret = 1;
return ret;
}
static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
{
struct extent_map *em1, *em2;
em1 = list_entry(a, struct extent_map, list);
em2 = list_entry(b, struct extent_map, list);
if (em1->start < em2->start)
return -1;
else if (em1->start > em2->start)
return 1;
return 0;
}
static int wait_ordered_extents(struct btrfs_trans_handle *trans,
struct inode *inode,
struct btrfs_root *root,
const struct extent_map *em,
const struct list_head *logged_list,
bool *ordered_io_error)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_ordered_extent *ordered;
struct btrfs_root *log = root->log_root;
u64 mod_start = em->mod_start;
u64 mod_len = em->mod_len;
const bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
u64 csum_offset;
u64 csum_len;
LIST_HEAD(ordered_sums);
int ret = 0;
*ordered_io_error = false;
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
em->block_start == EXTENT_MAP_HOLE)
return 0;
/*
* Wait far any ordered extent that covers our extent map. If it
* finishes without an error, first check and see if our csums are on
* our outstanding ordered extents.
*/
list_for_each_entry(ordered, logged_list, log_list) {
struct btrfs_ordered_sum *sum;
if (!mod_len)
break;
if (ordered->file_offset + ordered->len <= mod_start ||
mod_start + mod_len <= ordered->file_offset)
continue;
if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
!test_bit(BTRFS_ORDERED_IOERR, &ordered->flags) &&
!test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
const u64 start = ordered->file_offset;
const u64 end = ordered->file_offset + ordered->len - 1;
WARN_ON(ordered->inode != inode);
filemap_fdatawrite_range(inode->i_mapping, start, end);
}
wait_event(ordered->wait,
(test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) ||
test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)));
if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) {
/*
* Clear the AS_EIO/AS_ENOSPC flags from the inode's
* i_mapping flags, so that the next fsync won't get
* an outdated io error too.
*/
filemap_check_errors(inode->i_mapping);
*ordered_io_error = true;
break;
}
/*
* We are going to copy all the csums on this ordered extent, so
* go ahead and adjust mod_start and mod_len in case this
* ordered extent has already been logged.
*/
if (ordered->file_offset > mod_start) {
if (ordered->file_offset + ordered->len >=
mod_start + mod_len)
mod_len = ordered->file_offset - mod_start;
/*
* If we have this case
*
* |--------- logged extent ---------|
* |----- ordered extent ----|
*
* Just don't mess with mod_start and mod_len, we'll
* just end up logging more csums than we need and it
* will be ok.
*/
} else {
if (ordered->file_offset + ordered->len <
mod_start + mod_len) {
mod_len = (mod_start + mod_len) -
(ordered->file_offset + ordered->len);
mod_start = ordered->file_offset +
ordered->len;
} else {
mod_len = 0;
}
}
if (skip_csum)
continue;
/*
* To keep us from looping for the above case of an ordered
* extent that falls inside of the logged extent.
*/
if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM,
&ordered->flags))
continue;
list_for_each_entry(sum, &ordered->list, list) {
ret = btrfs_csum_file_blocks(trans, log, sum);
if (ret)
break;
}
}
if (*ordered_io_error || !mod_len || ret || skip_csum)
return ret;
if (em->compress_type) {
csum_offset = 0;
csum_len = max(em->block_len, em->orig_block_len);
} else {
csum_offset = mod_start - em->start;
csum_len = mod_len;
}
/* block start is already adjusted for the file extent offset. */
ret = btrfs_lookup_csums_range(fs_info->csum_root,
em->block_start + csum_offset,
em->block_start + csum_offset +
csum_len - 1, &ordered_sums, 0);
if (ret)
return ret;
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = btrfs_csum_file_blocks(trans, log, sums);
list_del(&sums->list);
kfree(sums);
}
return ret;
}
static int log_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, struct btrfs_root *root,
const struct extent_map *em,
struct btrfs_path *path,
const struct list_head *logged_list,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *log = root->log_root;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
struct btrfs_map_token token;
struct btrfs_key key;
u64 extent_offset = em->start - em->orig_start;
u64 block_len;
int ret;
int extent_inserted = 0;
bool ordered_io_err = false;
ret = wait_ordered_extents(trans, &inode->vfs_inode, root, em,
logged_list, &ordered_io_err);
if (ret)
return ret;
if (ordered_io_err) {
ctx->io_err = -EIO;
return 0;
}
btrfs_init_map_token(&token);
ret = __btrfs_drop_extents(trans, log, &inode->vfs_inode, path, em->start,
em->start + em->len, NULL, 0, 1,
sizeof(*fi), &extent_inserted);
if (ret)
return ret;
if (!extent_inserted) {
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = em->start;
ret = btrfs_insert_empty_item(trans, log, path, &key,
sizeof(*fi));
if (ret)
return ret;
}
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_token_file_extent_generation(leaf, fi, trans->transid,
&token);
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
btrfs_set_token_file_extent_type(leaf, fi,
BTRFS_FILE_EXTENT_PREALLOC,
&token);
else
btrfs_set_token_file_extent_type(leaf, fi,
BTRFS_FILE_EXTENT_REG,
&token);
block_len = max(em->block_len, em->orig_block_len);
if (em->compress_type != BTRFS_COMPRESS_NONE) {
btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
em->block_start,
&token);
btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
&token);
} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
em->block_start -
extent_offset, &token);
btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
&token);
} else {
btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token);
btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0,
&token);
}
btrfs_set_token_file_extent_offset(leaf, fi, extent_offset, &token);
btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token);
btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token);
btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type,
&token);
btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token);
btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
return ret;
}
static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct list_head *logged_list,
struct btrfs_log_ctx *ctx,
const u64 start,
const u64 end)
{
struct extent_map *em, *n;
struct list_head extents;
struct extent_map_tree *tree = &inode->extent_tree;
u64 logged_start, logged_end;
u64 test_gen;
int ret = 0;
int num = 0;
INIT_LIST_HEAD(&extents);
down_write(&inode->dio_sem);
write_lock(&tree->lock);
test_gen = root->fs_info->last_trans_committed;
logged_start = start;
logged_end = end;
list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
list_del_init(&em->list);
/*
* Just an arbitrary number, this can be really CPU intensive
* once we start getting a lot of extents, and really once we
* have a bunch of extents we just want to commit since it will
* be faster.
*/
if (++num > 32768) {
list_del_init(&tree->modified_extents);
ret = -EFBIG;
goto process;
}
if (em->generation <= test_gen)
continue;
if (em->start < logged_start)
logged_start = em->start;
if ((em->start + em->len - 1) > logged_end)
logged_end = em->start + em->len - 1;
/* Need a ref to keep it from getting evicted from cache */
refcount_inc(&em->refs);
set_bit(EXTENT_FLAG_LOGGING, &em->flags);
list_add_tail(&em->list, &extents);
num++;
}
list_sort(NULL, &extents, extent_cmp);
btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end);
/*
* Some ordered extents started by fsync might have completed
* before we could collect them into the list logged_list, which
* means they're gone, not in our logged_list nor in the inode's
* ordered tree. We want the application/user space to know an
* error happened while attempting to persist file data so that
* it can take proper action. If such error happened, we leave
* without writing to the log tree and the fsync must report the
* file data write error and not commit the current transaction.
*/
ret = filemap_check_errors(inode->vfs_inode.i_mapping);
if (ret)
ctx->io_err = ret;
process:
while (!list_empty(&extents)) {
em = list_entry(extents.next, struct extent_map, list);
list_del_init(&em->list);
/*
* If we had an error we just need to delete everybody from our
* private list.
*/
if (ret) {
clear_em_logging(tree, em);
free_extent_map(em);
continue;
}
write_unlock(&tree->lock);
ret = log_one_extent(trans, inode, root, em, path, logged_list,
ctx);
write_lock(&tree->lock);
clear_em_logging(tree, em);
free_extent_map(em);
}
WARN_ON(!list_empty(&extents));
write_unlock(&tree->lock);
up_write(&inode->dio_sem);
btrfs_release_path(path);
return ret;
}
static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
struct btrfs_path *path, u64 *size_ret)
{
struct btrfs_key key;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
if (ret < 0) {
return ret;
} else if (ret > 0) {
*size_ret = 0;
} else {
struct btrfs_inode_item *item;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
*size_ret = btrfs_inode_size(path->nodes[0], item);
}
btrfs_release_path(path);
return 0;
}
/*
* At the moment we always log all xattrs. This is to figure out at log replay
* time which xattrs must have their deletion replayed. If a xattr is missing
* in the log tree and exists in the fs/subvol tree, we delete it. This is
* because if a xattr is deleted, the inode is fsynced and a power failure
* happens, causing the log to be replayed the next time the fs is mounted,
* we want the xattr to not exist anymore (same behaviour as other filesystems
* with a journal, ext3/4, xfs, f2fs, etc).
*/
static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path)
{
int ret;
struct btrfs_key key;
const u64 ino = btrfs_ino(inode);
int ins_nr = 0;
int start_slot = 0;
key.objectid = ino;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
while (true) {
int slot = path->slots[0];
struct extent_buffer *leaf = path->nodes[0];
int nritems = btrfs_header_nritems(leaf);
if (slot >= nritems) {
if (ins_nr > 0) {
u64 last_extent = 0;
ret = copy_items(trans, inode, dst_path, path,
&last_extent, start_slot,
ins_nr, 1, 0);
/* can't be 1, extent items aren't processed */
ASSERT(ret <= 0);
if (ret < 0)
return ret;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
break;
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
cond_resched();
}
if (ins_nr > 0) {
u64 last_extent = 0;
ret = copy_items(trans, inode, dst_path, path,
&last_extent, start_slot,
ins_nr, 1, 0);
/* can't be 1, extent items aren't processed */
ASSERT(ret <= 0);
if (ret < 0)
return ret;
}
return 0;
}
/*
* If the no holes feature is enabled we need to make sure any hole between the
* last extent and the i_size of our inode is explicitly marked in the log. This
* is to make sure that doing something like:
*
* 1) create file with 128Kb of data
* 2) truncate file to 64Kb
* 3) truncate file to 256Kb
* 4) fsync file
* 5) <crash/power failure>
* 6) mount fs and trigger log replay
*
* Will give us a file with a size of 256Kb, the first 64Kb of data match what
* the file had in its first 64Kb of data at step 1 and the last 192Kb of the
* file correspond to a hole. The presence of explicit holes in a log tree is
* what guarantees that log replay will remove/adjust file extent items in the
* fs/subvol tree.
*
* Here we do not need to care about holes between extents, that is already done
* by copy_items(). We also only need to do this in the full sync path, where we
* lookup for extents from the fs/subvol tree only. In the fast path case, we
* lookup the list of modified extent maps and if any represents a hole, we
* insert a corresponding extent representing a hole in the log tree.
*/
static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
struct btrfs_path *path)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
struct btrfs_key key;
u64 hole_start;
u64 hole_size;
struct extent_buffer *leaf;
struct btrfs_root *log = root->log_root;
const u64 ino = btrfs_ino(inode);
const u64 i_size = i_size_read(&inode->vfs_inode);
if (!btrfs_fs_incompat(fs_info, NO_HOLES))
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
ASSERT(ret != 0);
if (ret < 0)
return ret;
ASSERT(path->slots[0] > 0);
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
/* inode does not have any extents */
hole_start = 0;
hole_size = i_size;
} else {
struct btrfs_file_extent_item *extent;
u64 len;
/*
* If there's an extent beyond i_size, an explicit hole was
* already inserted by copy_items().
*/
if (key.offset >= i_size)
return 0;
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, extent) ==
BTRFS_FILE_EXTENT_INLINE) {
len = btrfs_file_extent_inline_len(leaf,
path->slots[0],
extent);
ASSERT(len == i_size ||
(len == fs_info->sectorsize &&
btrfs_file_extent_compression(leaf, extent) !=
BTRFS_COMPRESS_NONE));
return 0;
}
len = btrfs_file_extent_num_bytes(leaf, extent);
/* Last extent goes beyond i_size, no need to log a hole. */
if (key.offset + len > i_size)
return 0;
hole_start = key.offset + len;
hole_size = i_size - hole_start;
}
btrfs_release_path(path);
/* Last extent ends at i_size. */
if (hole_size == 0)
return 0;
hole_size = ALIGN(hole_size, fs_info->sectorsize);
ret = btrfs_insert_file_extent(trans, log, ino, hole_start, 0, 0,
hole_size, 0, hole_size, 0, 0, 0);
return ret;
}
/*
* When we are logging a new inode X, check if it doesn't have a reference that
* matches the reference from some other inode Y created in a past transaction
* and that was renamed in the current transaction. If we don't do this, then at
* log replay time we can lose inode Y (and all its files if it's a directory):
*
* mkdir /mnt/x
* echo "hello world" > /mnt/x/foobar
* sync
* mv /mnt/x /mnt/y
* mkdir /mnt/x # or touch /mnt/x
* xfs_io -c fsync /mnt/x
* <power fail>
* mount fs, trigger log replay
*
* After the log replay procedure, we would lose the first directory and all its
* files (file foobar).
* For the case where inode Y is not a directory we simply end up losing it:
*
* echo "123" > /mnt/foo
* sync
* mv /mnt/foo /mnt/bar
* echo "abc" > /mnt/foo
* xfs_io -c fsync /mnt/foo
* <power fail>
*
* We also need this for cases where a snapshot entry is replaced by some other
* entry (file or directory) otherwise we end up with an unreplayable log due to
* attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
* if it were a regular entry:
*
* mkdir /mnt/x
* btrfs subvolume snapshot /mnt /mnt/x/snap
* btrfs subvolume delete /mnt/x/snap
* rmdir /mnt/x
* mkdir /mnt/x
* fsync /mnt/x or fsync some new file inside it
* <power fail>
*
* The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
* the same transaction.
*/
static int btrfs_check_ref_name_override(struct extent_buffer *eb,
const int slot,
const struct btrfs_key *key,
struct btrfs_inode *inode,
u64 *other_ino)
{
int ret;
struct btrfs_path *search_path;
char *name = NULL;
u32 name_len = 0;
u32 item_size = btrfs_item_size_nr(eb, slot);
u32 cur_offset = 0;
unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
search_path = btrfs_alloc_path();
if (!search_path)
return -ENOMEM;
search_path->search_commit_root = 1;
search_path->skip_locking = 1;
while (cur_offset < item_size) {
u64 parent;
u32 this_name_len;
u32 this_len;
unsigned long name_ptr;
struct btrfs_dir_item *di;
if (key->type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *iref;
iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
parent = key->offset;
this_name_len = btrfs_inode_ref_name_len(eb, iref);
name_ptr = (unsigned long)(iref + 1);
this_len = sizeof(*iref) + this_name_len;
} else {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)(ptr +
cur_offset);
parent = btrfs_inode_extref_parent(eb, extref);
this_name_len = btrfs_inode_extref_name_len(eb, extref);
name_ptr = (unsigned long)&extref->name;
this_len = sizeof(*extref) + this_name_len;
}
ret = btrfs_is_name_len_valid(eb, slot, name_ptr,
this_name_len);
if (!ret) {
ret = -EIO;
goto out;
}
if (this_name_len > name_len) {
char *new_name;
new_name = krealloc(name, this_name_len, GFP_NOFS);
if (!new_name) {
ret = -ENOMEM;
goto out;
}
name_len = this_name_len;
name = new_name;
}
read_extent_buffer(eb, name, name_ptr, this_name_len);
di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
parent, name, this_name_len, 0);
if (di && !IS_ERR(di)) {
struct btrfs_key di_key;
btrfs_dir_item_key_to_cpu(search_path->nodes[0],
di, &di_key);
if (di_key.type == BTRFS_INODE_ITEM_KEY) {
ret = 1;
*other_ino = di_key.objectid;
} else {
ret = -EAGAIN;
}
goto out;
} else if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
btrfs_release_path(search_path);
cur_offset += this_len;
}
ret = 0;
out:
btrfs_free_path(search_path);
kfree(name);
return ret;
}
/* log a single inode in the tree log.
* At least one parent directory for this inode must exist in the tree
* or be logged already.
*
* Any items from this inode changed by the current transaction are copied
* to the log tree. An extra reference is taken on any extents in this
* file, allowing us to avoid a whole pile of corner cases around logging
* blocks that have been removed from the tree.
*
* See LOG_INODE_ALL and related defines for a description of what inode_only
* does.
*
* This handles both files and directories.
*/
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
int inode_only,
const loff_t start,
const loff_t end,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct btrfs_path *dst_path;
struct btrfs_key min_key;
struct btrfs_key max_key;
struct btrfs_root *log = root->log_root;
struct extent_buffer *src = NULL;
LIST_HEAD(logged_list);
u64 last_extent = 0;
int err = 0;
int ret;
int nritems;
int ins_start_slot = 0;
int ins_nr;
bool fast_search = false;
u64 ino = btrfs_ino(inode);
struct extent_map_tree *em_tree = &inode->extent_tree;
u64 logged_isize = 0;
bool need_log_inode_item = true;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dst_path = btrfs_alloc_path();
if (!dst_path) {
btrfs_free_path(path);
return -ENOMEM;
}
min_key.objectid = ino;
min_key.type = BTRFS_INODE_ITEM_KEY;
min_key.offset = 0;
max_key.objectid = ino;
/* today the code can only do partial logging of directories */
if (S_ISDIR(inode->vfs_inode.i_mode) ||
(!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags) &&
inode_only >= LOG_INODE_EXISTS))
max_key.type = BTRFS_XATTR_ITEM_KEY;
else
max_key.type = (u8)-1;
max_key.offset = (u64)-1;
/*
* Only run delayed items if we are a dir or a new file.
* Otherwise commit the delayed inode only, which is needed in
* order for the log replay code to mark inodes for link count
* fixup (create temporary BTRFS_TREE_LOG_FIXUP_OBJECTID items).
*/
if (S_ISDIR(inode->vfs_inode.i_mode) ||
inode->generation > fs_info->last_trans_committed)
ret = btrfs_commit_inode_delayed_items(trans, inode);
else
ret = btrfs_commit_inode_delayed_inode(inode);
if (ret) {
btrfs_free_path(path);
btrfs_free_path(dst_path);
return ret;
}
if (inode_only == LOG_OTHER_INODE) {
inode_only = LOG_INODE_EXISTS;
mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING);
} else {
mutex_lock(&inode->log_mutex);
}
/*
* a brute force approach to making sure we get the most uptodate
* copies of everything.
*/
if (S_ISDIR(inode->vfs_inode.i_mode)) {
int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
if (inode_only == LOG_INODE_EXISTS)
max_key_type = BTRFS_XATTR_ITEM_KEY;
ret = drop_objectid_items(trans, log, path, ino, max_key_type);
} else {
if (inode_only == LOG_INODE_EXISTS) {
/*
* Make sure the new inode item we write to the log has
* the same isize as the current one (if it exists).
* This is necessary to prevent data loss after log
* replay, and also to prevent doing a wrong expanding
* truncate - for e.g. create file, write 4K into offset
* 0, fsync, write 4K into offset 4096, add hard link,
* fsync some other file (to sync log), power fail - if
* we use the inode's current i_size, after log replay
* we get a 8Kb file, with the last 4Kb extent as a hole
* (zeroes), as if an expanding truncate happened,
* instead of getting a file of 4Kb only.
*/
err = logged_inode_size(log, inode, path, &logged_isize);
if (err)
goto out_unlock;
}
if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags)) {
if (inode_only == LOG_INODE_EXISTS) {
max_key.type = BTRFS_XATTR_ITEM_KEY;
ret = drop_objectid_items(trans, log, path, ino,
max_key.type);
} else {
clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags);
clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags);
while(1) {
ret = btrfs_truncate_inode_items(trans,
log, &inode->vfs_inode, 0, 0);
if (ret != -EAGAIN)
break;
}
}
} else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags) ||
inode_only == LOG_INODE_EXISTS) {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
max_key.type = BTRFS_XATTR_ITEM_KEY;
ret = drop_objectid_items(trans, log, path, ino,
max_key.type);
} else {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
goto log_extents;
}
}
if (ret) {
err = ret;
goto out_unlock;
}
while (1) {
ins_nr = 0;
ret = btrfs_search_forward(root, &min_key,
path, trans->transid);
if (ret < 0) {
err = ret;
goto out_unlock;
}
if (ret != 0)
break;
again:
/* note, ins_nr might be > 0 here, cleanup outside the loop */
if (min_key.objectid != ino)
break;
if (min_key.type > max_key.type)
break;
if (min_key.type == BTRFS_INODE_ITEM_KEY)
need_log_inode_item = false;
if ((min_key.type == BTRFS_INODE_REF_KEY ||
min_key.type == BTRFS_INODE_EXTREF_KEY) &&
inode->generation == trans->transid) {
u64 other_ino = 0;
ret = btrfs_check_ref_name_override(path->nodes[0],
path->slots[0], &min_key, inode,
&other_ino);
if (ret < 0) {
err = ret;
goto out_unlock;
} else if (ret > 0 && ctx &&
other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
struct btrfs_key inode_key;
struct inode *other_inode;
if (ins_nr > 0) {
ins_nr++;
} else {
ins_nr = 1;
ins_start_slot = path->slots[0];
}
ret = copy_items(trans, inode, dst_path, path,
&last_extent, ins_start_slot,
ins_nr, inode_only,
logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ins_nr = 0;
btrfs_release_path(path);
inode_key.objectid = other_ino;
inode_key.type = BTRFS_INODE_ITEM_KEY;
inode_key.offset = 0;
other_inode = btrfs_iget(fs_info->sb,
&inode_key, root,
NULL);
/*
* If the other inode that had a conflicting dir
* entry was deleted in the current transaction,
* we don't need to do more work nor fallback to
* a transaction commit.
*/
if (IS_ERR(other_inode) &&
PTR_ERR(other_inode) == -ENOENT) {
goto next_key;
} else if (IS_ERR(other_inode)) {
err = PTR_ERR(other_inode);
goto out_unlock;
}
/*
* We are safe logging the other inode without
* acquiring its i_mutex as long as we log with
* the LOG_INODE_EXISTS mode. We're safe against
* concurrent renames of the other inode as well
* because during a rename we pin the log and
* update the log with the new name before we
* unpin it.
*/
err = btrfs_log_inode(trans, root,
BTRFS_I(other_inode),
LOG_OTHER_INODE, 0, LLONG_MAX,
ctx);
iput(other_inode);
if (err)
goto out_unlock;
else
goto next_key;
}
}
/* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
if (min_key.type == BTRFS_XATTR_ITEM_KEY) {
if (ins_nr == 0)
goto next_slot;
ret = copy_items(trans, inode, dst_path, path,
&last_extent, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ins_nr = 0;
if (ret) {
btrfs_release_path(path);
continue;
}
goto next_slot;
}
src = path->nodes[0];
if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
ins_nr++;
goto next_slot;
} else if (!ins_nr) {
ins_start_slot = path->slots[0];
ins_nr = 1;
goto next_slot;
}
ret = copy_items(trans, inode, dst_path, path, &last_extent,
ins_start_slot, ins_nr, inode_only,
logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
if (ret) {
ins_nr = 0;
btrfs_release_path(path);
continue;
}
ins_nr = 1;
ins_start_slot = path->slots[0];
next_slot:
nritems = btrfs_header_nritems(path->nodes[0]);
path->slots[0]++;
if (path->slots[0] < nritems) {
btrfs_item_key_to_cpu(path->nodes[0], &min_key,
path->slots[0]);
goto again;
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path,
&last_extent, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ret = 0;
ins_nr = 0;
}
btrfs_release_path(path);
next_key:
if (min_key.offset < (u64)-1) {
min_key.offset++;
} else if (min_key.type < max_key.type) {
min_key.type++;
min_key.offset = 0;
} else {
break;
}
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path, &last_extent,
ins_start_slot, ins_nr, inode_only,
logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ret = 0;
ins_nr = 0;
}
btrfs_release_path(path);
btrfs_release_path(dst_path);
err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path);
if (err)
goto out_unlock;
if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
btrfs_release_path(path);
btrfs_release_path(dst_path);
err = btrfs_log_trailing_hole(trans, root, inode, path);
if (err)
goto out_unlock;
}
log_extents:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (need_log_inode_item) {
err = log_inode_item(trans, log, dst_path, inode);
if (err)
goto out_unlock;
}
if (fast_search) {
ret = btrfs_log_changed_extents(trans, root, inode, dst_path,
&logged_list, ctx, start, end);
if (ret) {
err = ret;
goto out_unlock;
}
} else if (inode_only == LOG_INODE_ALL) {
struct extent_map *em, *n;
write_lock(&em_tree->lock);
/*
* We can't just remove every em if we're called for a ranged
* fsync - that is, one that doesn't cover the whole possible
* file range (0 to LLONG_MAX). This is because we can have
* em's that fall outside the range we're logging and therefore
* their ordered operations haven't completed yet
* (btrfs_finish_ordered_io() not invoked yet). This means we
* didn't get their respective file extent item in the fs/subvol
* tree yet, and need to let the next fast fsync (one which
* consults the list of modified extent maps) find the em so
* that it logs a matching file extent item and waits for the
* respective ordered operation to complete (if it's still
* running).
*
* Removing every em outside the range we're logging would make
* the next fast fsync not log their matching file extent items,
* therefore making us lose data after a log replay.
*/
list_for_each_entry_safe(em, n, &em_tree->modified_extents,
list) {
const u64 mod_end = em->mod_start + em->mod_len - 1;
if (em->mod_start >= start && mod_end <= end)
list_del_init(&em->list);
}
write_unlock(&em_tree->lock);
}
if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) {
ret = log_directory_changes(trans, root, inode, path, dst_path,
ctx);
if (ret) {
err = ret;
goto out_unlock;
}
}
spin_lock(&inode->lock);
inode->logged_trans = trans->transid;
inode->last_log_commit = inode->last_sub_trans;
spin_unlock(&inode->lock);
out_unlock:
if (unlikely(err))
btrfs_put_logged_extents(&logged_list);
else
btrfs_submit_logged_extents(&logged_list, log);
mutex_unlock(&inode->log_mutex);
btrfs_free_path(path);
btrfs_free_path(dst_path);
return err;
}
/*
* Check if we must fallback to a transaction commit when logging an inode.
* This must be called after logging the inode and is used only in the context
* when fsyncing an inode requires the need to log some other inode - in which
* case we can't lock the i_mutex of each other inode we need to log as that
* can lead to deadlocks with concurrent fsync against other inodes (as we can
* log inodes up or down in the hierarchy) or rename operations for example. So
* we take the log_mutex of the inode after we have logged it and then check for
* its last_unlink_trans value - this is safe because any task setting
* last_unlink_trans must take the log_mutex and it must do this before it does
* the actual unlink operation, so if we do this check before a concurrent task
* sets last_unlink_trans it means we've logged a consistent version/state of
* all the inode items, otherwise we are not sure and must do a transaction
* commit (the concurrent task might have only updated last_unlink_trans before
* we logged the inode or it might have also done the unlink).
*/
static bool btrfs_must_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
bool ret = false;
mutex_lock(&inode->log_mutex);
if (inode->last_unlink_trans > fs_info->last_trans_committed) {
/*
* Make sure any commits to the log are forced to be full
* commits.
*/
btrfs_set_log_full_commit(fs_info, trans);
ret = true;
}
mutex_unlock(&inode->log_mutex);
return ret;
}
/*
* follow the dentry parent pointers up the chain and see if any
* of the directories in it require a full commit before they can
* be logged. Returns zero if nothing special needs to be done or 1 if
* a full commit is required.
*/
static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct super_block *sb,
u64 last_committed)
{
int ret = 0;
struct dentry *old_parent = NULL;
struct btrfs_inode *orig_inode = inode;
/*
* for regular files, if its inode is already on disk, we don't
* have to worry about the parents at all. This is because
* we can use the last_unlink_trans field to record renames
* and other fun in this file.
*/
if (S_ISREG(inode->vfs_inode.i_mode) &&
inode->generation <= last_committed &&
inode->last_unlink_trans <= last_committed)
goto out;
if (!S_ISDIR(inode->vfs_inode.i_mode)) {
if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
goto out;
inode = BTRFS_I(d_inode(parent));
}
while (1) {
/*
* If we are logging a directory then we start with our inode,
* not our parent's inode, so we need to skip setting the
* logged_trans so that further down in the log code we don't
* think this inode has already been logged.
*/
if (inode != orig_inode)
inode->logged_trans = trans->transid;
smp_mb();
if (btrfs_must_commit_transaction(trans, inode)) {
ret = 1;
break;
}
if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
break;
if (IS_ROOT(parent)) {
inode = BTRFS_I(d_inode(parent));
if (btrfs_must_commit_transaction(trans, inode))
ret = 1;
break;
}
parent = dget_parent(parent);
dput(old_parent);
old_parent = parent;
inode = BTRFS_I(d_inode(parent));
}
dput(old_parent);
out:
return ret;
}
struct btrfs_dir_list {
u64 ino;
struct list_head list;
};
/*
* Log the inodes of the new dentries of a directory. See log_dir_items() for
* details about the why it is needed.
* This is a recursive operation - if an existing dentry corresponds to a
* directory, that directory's new entries are logged too (same behaviour as
* ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
* the dentries point to we do not lock their i_mutex, otherwise lockdep
* complains about the following circular lock dependency / possible deadlock:
*
* CPU0 CPU1
* ---- ----
* lock(&type->i_mutex_dir_key#3/2);
* lock(sb_internal#2);
* lock(&type->i_mutex_dir_key#3/2);
* lock(&sb->s_type->i_mutex_key#14);
*
* Where sb_internal is the lock (a counter that works as a lock) acquired by
* sb_start_intwrite() in btrfs_start_transaction().
* Not locking i_mutex of the inodes is still safe because:
*
* 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
* that while logging the inode new references (names) are added or removed
* from the inode, leaving the logged inode item with a link count that does
* not match the number of logged inode reference items. This is fine because
* at log replay time we compute the real number of links and correct the
* link count in the inode item (see replay_one_buffer() and
* link_to_fixup_dir());
*
* 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
* while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and
* BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item
* has a size that doesn't match the sum of the lengths of all the logged
* names. This does not result in a problem because if a dir_item key is
* logged but its matching dir_index key is not logged, at log replay time we
* don't use it to replay the respective name (see replay_one_name()). On the
* other hand if only the dir_index key ends up being logged, the respective
* name is added to the fs/subvol tree with both the dir_item and dir_index
* keys created (see replay_one_name()).
* The directory's inode item with a wrong i_size is not a problem as well,
* since we don't use it at log replay time to set the i_size in the inode
* item of the fs/subvol tree (see overwrite_item()).
*/
static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *start_inode,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *log = root->log_root;
struct btrfs_path *path;
LIST_HEAD(dir_list);
struct btrfs_dir_list *dir_elem;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
if (!dir_elem) {
btrfs_free_path(path);
return -ENOMEM;
}
dir_elem->ino = btrfs_ino(start_inode);
list_add_tail(&dir_elem->list, &dir_list);
while (!list_empty(&dir_list)) {
struct extent_buffer *leaf;
struct btrfs_key min_key;
int nritems;
int i;
dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list,
list);
if (ret)
goto next_dir_inode;
min_key.objectid = dir_elem->ino;
min_key.type = BTRFS_DIR_ITEM_KEY;
min_key.offset = 0;
again:
btrfs_release_path(path);
ret = btrfs_search_forward(log, &min_key, path, trans->transid);
if (ret < 0) {
goto next_dir_inode;
} else if (ret > 0) {
ret = 0;
goto next_dir_inode;
}
process_leaf:
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key di_key;
struct inode *di_inode;
struct btrfs_dir_list *new_dir_elem;
int log_mode = LOG_INODE_EXISTS;
int type;
btrfs_item_key_to_cpu(leaf, &min_key, i);
if (min_key.objectid != dir_elem->ino ||
min_key.type != BTRFS_DIR_ITEM_KEY)
goto next_dir_inode;
di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
type = btrfs_dir_type(leaf, di);
if (btrfs_dir_transid(leaf, di) < trans->transid &&
type != BTRFS_FT_DIR)
continue;
btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
if (di_key.type == BTRFS_ROOT_ITEM_KEY)
continue;
btrfs_release_path(path);
di_inode = btrfs_iget(fs_info->sb, &di_key, root, NULL);
if (IS_ERR(di_inode)) {
ret = PTR_ERR(di_inode);
goto next_dir_inode;
}
if (btrfs_inode_in_log(BTRFS_I(di_inode), trans->transid)) {
iput(di_inode);
break;
}
ctx->log_new_dentries = false;
if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK)
log_mode = LOG_INODE_ALL;
ret = btrfs_log_inode(trans, root, BTRFS_I(di_inode),
log_mode, 0, LLONG_MAX, ctx);
if (!ret &&
btrfs_must_commit_transaction(trans, BTRFS_I(di_inode)))
ret = 1;
iput(di_inode);
if (ret)
goto next_dir_inode;
if (ctx->log_new_dentries) {
new_dir_elem = kmalloc(sizeof(*new_dir_elem),
GFP_NOFS);
if (!new_dir_elem) {
ret = -ENOMEM;
goto next_dir_inode;
}
new_dir_elem->ino = di_key.objectid;
list_add_tail(&new_dir_elem->list, &dir_list);
}
break;
}
if (i == nritems) {
ret = btrfs_next_leaf(log, path);
if (ret < 0) {
goto next_dir_inode;
} else if (ret > 0) {
ret = 0;
goto next_dir_inode;
}
goto process_leaf;
}
if (min_key.offset < (u64)-1) {
min_key.offset++;
goto again;
}
next_dir_inode:
list_del(&dir_elem->list);
kfree(dir_elem);
}
btrfs_free_path(path);
return ret;
}
static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->skip_locking = 1;
path->search_commit_root = 1;
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
u32 cur_offset = 0;
u32 item_size;
unsigned long ptr;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
/* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
break;
item_size = btrfs_item_size_nr(leaf, slot);
ptr = btrfs_item_ptr_offset(leaf, slot);
while (cur_offset < item_size) {
struct btrfs_key inode_key;
struct inode *dir_inode;
inode_key.type = BTRFS_INODE_ITEM_KEY;
inode_key.offset = 0;
if (key.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)
(ptr + cur_offset);
inode_key.objectid = btrfs_inode_extref_parent(
leaf, extref);
cur_offset += sizeof(*extref);
cur_offset += btrfs_inode_extref_name_len(leaf,
extref);
} else {
inode_key.objectid = key.offset;
cur_offset = item_size;
}
dir_inode = btrfs_iget(fs_info->sb, &inode_key,
root, NULL);
/* If parent inode was deleted, skip it. */
if (IS_ERR(dir_inode))
continue;
if (ctx)
ctx->log_new_dentries = false;
ret = btrfs_log_inode(trans, root, BTRFS_I(dir_inode),
LOG_INODE_ALL, 0, LLONG_MAX, ctx);
if (!ret &&
btrfs_must_commit_transaction(trans, BTRFS_I(dir_inode)))
ret = 1;
if (!ret && ctx && ctx->log_new_dentries)
ret = log_new_dir_dentries(trans, root,
BTRFS_I(dir_inode), ctx);
iput(dir_inode);
if (ret)
goto out;
}
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function around btrfs_log_inode to make sure newly created
* parent directories also end up in the log. A minimal inode and backref
* only logging is done of any parent directories that are older than
* the last committed transaction
*/
static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
struct dentry *parent,
const loff_t start,
const loff_t end,
int exists_only,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
struct super_block *sb;
struct dentry *old_parent = NULL;
int ret = 0;
u64 last_committed = fs_info->last_trans_committed;
bool log_dentries = false;
struct btrfs_inode *orig_inode = inode;
sb = inode->vfs_inode.i_sb;
if (btrfs_test_opt(fs_info, NOTREELOG)) {
ret = 1;
goto end_no_trans;
}
/*
* The prev transaction commit doesn't complete, we need do
* full commit by ourselves.
*/
if (fs_info->last_trans_log_full_commit >
fs_info->last_trans_committed) {
ret = 1;
goto end_no_trans;
}
if (root != inode->root || btrfs_root_refs(&root->root_item) == 0) {
ret = 1;
goto end_no_trans;
}
ret = check_parent_dirs_for_sync(trans, inode, parent, sb,
last_committed);
if (ret)
goto end_no_trans;
if (btrfs_inode_in_log(inode, trans->transid)) {
ret = BTRFS_NO_LOG_SYNC;
goto end_no_trans;
}
ret = start_log_trans(trans, root, ctx);
if (ret)
goto end_no_trans;
ret = btrfs_log_inode(trans, root, inode, inode_only, start, end, ctx);
if (ret)
goto end_trans;
/*
* for regular files, if its inode is already on disk, we don't
* have to worry about the parents at all. This is because
* we can use the last_unlink_trans field to record renames
* and other fun in this file.
*/
if (S_ISREG(inode->vfs_inode.i_mode) &&
inode->generation <= last_committed &&
inode->last_unlink_trans <= last_committed) {
ret = 0;
goto end_trans;
}
if (S_ISDIR(inode->vfs_inode.i_mode) && ctx && ctx->log_new_dentries)
log_dentries = true;
/*
* On unlink we must make sure all our current and old parent directory
* inodes are fully logged. This is to prevent leaving dangling
* directory index entries in directories that were our parents but are
* not anymore. Not doing this results in old parent directory being
* impossible to delete after log replay (rmdir will always fail with
* error -ENOTEMPTY).
*
* Example 1:
*
* mkdir testdir
* touch testdir/foo
* ln testdir/foo testdir/bar
* sync
* unlink testdir/bar
* xfs_io -c fsync testdir/foo
* <power failure>
* mount fs, triggers log replay
*
* If we don't log the parent directory (testdir), after log replay the
* directory still has an entry pointing to the file inode using the bar
* name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
* the file inode has a link count of 1.
*
* Example 2:
*
* mkdir testdir
* touch foo
* ln foo testdir/foo2
* ln foo testdir/foo3
* sync
* unlink testdir/foo3
* xfs_io -c fsync foo
* <power failure>
* mount fs, triggers log replay
*
* Similar as the first example, after log replay the parent directory
* testdir still has an entry pointing to the inode file with name foo3
* but the file inode does not have a matching BTRFS_INODE_REF_KEY item
* and has a link count of 2.
*/
if (inode->last_unlink_trans > last_committed) {
ret = btrfs_log_all_parents(trans, orig_inode, ctx);
if (ret)
goto end_trans;
}
while (1) {
if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
break;
inode = BTRFS_I(d_inode(parent));
if (root != inode->root)
break;
if (inode->generation > last_committed) {
ret = btrfs_log_inode(trans, root, inode,
LOG_INODE_EXISTS, 0, LLONG_MAX, ctx);
if (ret)
goto end_trans;
}
if (IS_ROOT(parent))
break;
parent = dget_parent(parent);
dput(old_parent);
old_parent = parent;
}
if (log_dentries)
ret = log_new_dir_dentries(trans, root, orig_inode, ctx);
else
ret = 0;
end_trans:
dput(old_parent);
if (ret < 0) {
btrfs_set_log_full_commit(fs_info, trans);
ret = 1;
}
if (ret)
btrfs_remove_log_ctx(root, ctx);
btrfs_end_log_trans(root);
end_no_trans:
return ret;
}
/*
* it is not safe to log dentry if the chunk root has added new
* chunks. This returns 0 if the dentry was logged, and 1 otherwise.
* If this returns 1, you must commit the transaction to safely get your
* data on disk.
*/
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct dentry *dentry,
const loff_t start,
const loff_t end,
struct btrfs_log_ctx *ctx)
{
struct dentry *parent = dget_parent(dentry);
int ret;
ret = btrfs_log_inode_parent(trans, root, BTRFS_I(d_inode(dentry)),
parent, start, end, 0, ctx);
dput(parent);
return ret;
}
/*
* should be called during mount to recover any replay any log trees
* from the FS
*/
int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
{
int ret;
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_key tmp_key;
struct btrfs_root *log;
struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
struct walk_control wc = {
.process_func = process_one_buffer,
.stage = 0,
};
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
trans = btrfs_start_transaction(fs_info->tree_root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto error;
}
wc.trans = trans;
wc.pin = 1;
ret = walk_log_tree(trans, log_root_tree, &wc);
if (ret) {
btrfs_handle_fs_error(fs_info, ret,
"Failed to pin buffers while recovering log root tree.");
goto error;
}
again:
key.objectid = BTRFS_TREE_LOG_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_ROOT_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
if (ret < 0) {
btrfs_handle_fs_error(fs_info, ret,
"Couldn't find tree log root.");
goto error;
}
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
btrfs_release_path(path);
if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
break;
log = btrfs_read_fs_root(log_root_tree, &found_key);
if (IS_ERR(log)) {
ret = PTR_ERR(log);
btrfs_handle_fs_error(fs_info, ret,
"Couldn't read tree log root.");
goto error;
}
tmp_key.objectid = found_key.offset;
tmp_key.type = BTRFS_ROOT_ITEM_KEY;
tmp_key.offset = (u64)-1;
wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
if (IS_ERR(wc.replay_dest)) {
ret = PTR_ERR(wc.replay_dest);
free_extent_buffer(log->node);
free_extent_buffer(log->commit_root);
kfree(log);
btrfs_handle_fs_error(fs_info, ret,
"Couldn't read target root for tree log recovery.");
goto error;
}
wc.replay_dest->log_root = log;
btrfs_record_root_in_trans(trans, wc.replay_dest);
ret = walk_log_tree(trans, log, &wc);
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
ret = fixup_inode_link_counts(trans, wc.replay_dest,
path);
}
key.offset = found_key.offset - 1;
wc.replay_dest->log_root = NULL;
free_extent_buffer(log->node);
free_extent_buffer(log->commit_root);
kfree(log);
if (ret)
goto error;
if (found_key.offset == 0)
break;
}
btrfs_release_path(path);
/* step one is to pin it all, step two is to replay just inodes */
if (wc.pin) {
wc.pin = 0;
wc.process_func = replay_one_buffer;
wc.stage = LOG_WALK_REPLAY_INODES;
goto again;
}
/* step three is to replay everything */
if (wc.stage < LOG_WALK_REPLAY_ALL) {
wc.stage++;
goto again;
}
btrfs_free_path(path);
/* step 4: commit the transaction, which also unpins the blocks */
ret = btrfs_commit_transaction(trans);
if (ret)
return ret;
free_extent_buffer(log_root_tree->node);
log_root_tree->log_root = NULL;
clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
kfree(log_root_tree);
return 0;
error:
if (wc.trans)
btrfs_end_transaction(wc.trans);
btrfs_free_path(path);
return ret;
}
/*
* there are some corner cases where we want to force a full
* commit instead of allowing a directory to be logged.
*
* They revolve around files there were unlinked from the directory, and
* this function updates the parent directory so that a full commit is
* properly done if it is fsync'd later after the unlinks are done.
*
* Must be called before the unlink operations (updates to the subvolume tree,
* inodes, etc) are done.
*/
void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
int for_rename)
{
/*
* when we're logging a file, if it hasn't been renamed
* or unlinked, and its inode is fully committed on disk,
* we don't have to worry about walking up the directory chain
* to log its parents.
*
* So, we use the last_unlink_trans field to put this transid
* into the file. When the file is logged we check it and
* don't log the parents if the file is fully on disk.
*/
mutex_lock(&inode->log_mutex);
inode->last_unlink_trans = trans->transid;
mutex_unlock(&inode->log_mutex);
/*
* if this directory was already logged any new
* names for this file/dir will get recorded
*/
smp_mb();
if (dir->logged_trans == trans->transid)
return;
/*
* if the inode we're about to unlink was logged,
* the log will be properly updated for any new names
*/
if (inode->logged_trans == trans->transid)
return;
/*
* when renaming files across directories, if the directory
* there we're unlinking from gets fsync'd later on, there's
* no way to find the destination directory later and fsync it
* properly. So, we have to be conservative and force commits
* so the new name gets discovered.
*/
if (for_rename)
goto record;
/* we can safely do the unlink without any special recording */
return;
record:
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
}
/*
* Make sure that if someone attempts to fsync the parent directory of a deleted
* snapshot, it ends up triggering a transaction commit. This is to guarantee
* that after replaying the log tree of the parent directory's root we will not
* see the snapshot anymore and at log replay time we will not see any log tree
* corresponding to the deleted snapshot's root, which could lead to replaying
* it after replaying the log tree of the parent directory (which would replay
* the snapshot delete operation).
*
* Must be called before the actual snapshot destroy operation (updates to the
* parent root and tree of tree roots trees, etc) are done.
*/
void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir)
{
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
}
/*
* Call this after adding a new name for a file and it will properly
* update the log to reflect the new name.
*
* It will return zero if all goes well, and it will return 1 if a
* full transaction commit is required.
*/
int btrfs_log_new_name(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, struct btrfs_inode *old_dir,
struct dentry *parent)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
struct btrfs_root *root = inode->root;
/*
* this will force the logging code to walk the dentry chain
* up for the file
*/
if (S_ISREG(inode->vfs_inode.i_mode))
inode->last_unlink_trans = trans->transid;
/*
* if this inode hasn't been logged and directory we're renaming it
* from hasn't been logged, we don't need to log it
*/
if (inode->logged_trans <= fs_info->last_trans_committed &&
(!old_dir || old_dir->logged_trans <= fs_info->last_trans_committed))
return 0;
return btrfs_log_inode_parent(trans, root, inode, parent, 0,
LLONG_MAX, 1, NULL);
}
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