linux-uconsole/fs/btrfs
Filipe Manana 4fd45ef704 btrfs: always log symlinks in full mode
commit d0e64a981f upstream.

On Linux, empty symlinks are invalid, and attempting to create one with
the system call symlink(2) results in an -ENOENT error and this is
explicitly documented in the man page.

If we rename a symlink that was created in the current transaction and its
parent directory was logged before, we actually end up logging the symlink
without logging its content, which is stored in an inline extent. That
means that after a power failure we can end up with an empty symlink,
having no content and an i_size of 0 bytes.

It can be easily reproduced like this:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  $ mkdir /mnt/testdir
  $ sync

  # Create a file inside the directory and fsync the directory.
  $ touch /mnt/testdir/foo
  $ xfs_io -c "fsync" /mnt/testdir

  # Create a symlink inside the directory and then rename the symlink.
  $ ln -s /mnt/testdir/foo /mnt/testdir/bar
  $ mv /mnt/testdir/bar /mnt/testdir/baz

  # Now fsync again the directory, this persist the log tree.
  $ xfs_io -c "fsync" /mnt/testdir

  <power failure>

  $ mount /dev/sdc /mnt
  $ stat -c %s /mnt/testdir/baz
  0
  $ readlink /mnt/testdir/baz
  $

Fix this by always logging symlinks in full mode (LOG_INODE_ALL), so that
their content is also logged.

A test case for fstests will follow.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-12 12:25:43 +02:00
..
tests btrfs: fix missing delalloc new bit for new delalloc ranges 2020-11-13 22:15:59 +01:00
acl.c
async-thread.c btrfs: fix memory ordering between normal and ordered work functions 2021-11-26 10:39:20 +01:00
async-thread.h Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
backref.c btrfs: remove BUG_ON(!eie) in find_parent_nodes 2022-01-27 10:54:19 +01:00
backref.h btrfs: add asserts for deleting backref cache nodes 2021-03-04 11:38:29 +01:00
block-group.c btrfs: remove unused variable in btrfs_{start,write}_dirty_block_groups() 2022-04-20 09:23:10 +02:00
block-group.h btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
block-rsv.c btrfs: print the block rsv type when we fail our reservation 2020-11-05 13:02:05 +01:00
block-rsv.h btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
btrfs_inode.h btrfs: fix race between marking inode needs to be logged and log syncing 2021-09-03 10:09:28 +02:00
check-integrity.c btrfs: check-integrity: remove unnecessary failure messages during memory allocation 2020-07-27 12:55:21 +02:00
check-integrity.h btrfs: remove btrfsic_submit_bh() 2020-03-23 17:01:39 +01:00
compression.c btrfs: mark compressed range uptodate only if all bio succeed 2021-08-04 12:46:39 +02:00
compression.h btrfs: compression: move declarations to header 2020-10-07 12:06:55 +02:00
ctree.c btrfs: check the root node for uptodate before returning it 2022-01-27 10:54:27 +01:00
ctree.h btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
delalloc-space.c btrfs: add btrfs_reserve_data_bytes and use it 2020-10-07 12:06:52 +02:00
delalloc-space.h btrfs: make btrfs_delalloc_reserve_space take btrfs_inode 2020-07-27 12:55:36 +02:00
delayed-inode.c btrfs: abort transaction if we fail to update the delayed inode 2021-07-14 16:55:55 +02:00
delayed-inode.h btrfs: delayed-inode: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
delayed-ref.c btrfs: account for new extents being deleted in total_bytes_pinned 2021-03-04 11:38:30 +01:00
delayed-ref.h btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-03-04 11:38:30 +01:00
dev-replace.c btrfs: fix deadlock when cloning inline extent and low on free metadata space 2021-01-17 14:16:54 +01:00
dev-replace.h
dir-item.c
discard.c btrfs: merge critical sections of discard lock in workfn 2021-01-19 18:27:24 +01:00
discard.h btrfs: discard: Use the correct style for SPDX License Identifier 2020-04-20 17:43:42 +02:00
disk-io.c btrfs: fix root ref counts in error handling in btrfs_get_root_ref 2022-04-20 09:23:27 +02:00
disk-io.h btrfs: add a helper to read the tree_root commit root for backref lookup 2020-10-26 15:04:57 +01:00
export.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
export.h btrfs: export helpers for subvolume name/id resolution 2020-03-23 17:01:42 +01:00
extent-io-tree.h btrfs: remove struct extent_io_ops 2020-10-07 12:13:25 +02:00
extent-tree.c btrfs: unlock newly allocated extent buffer after error 2021-10-20 11:44:59 +02:00
extent_io.c btrfs: clear extent buffer uptodate when we fail to write it 2021-12-14 11:32:38 +01:00
extent_io.h btrfs: fix qgroup reserve overflow the qgroup limit 2022-04-13 21:01:08 +02:00
extent_map.c Btrfs: fix race between using extent maps and merging them 2020-02-12 17:16:46 +01:00
extent_map.h btrfs: remove extent_map::bdev 2019-11-18 23:43:44 +01:00
file-item.c btrfs: replace BUG_ON() in btrfs_csum_one_bio() with proper error handling 2021-10-09 14:40:56 +02:00
file.c btrfs: fix fallocate to use file_modified to update permissions consistently 2022-04-20 09:23:19 +02:00
free-space-cache.c btrfs: fix race between extent freeing/allocation when using bitmaps 2021-03-09 11:11:11 +01:00
free-space-cache.h btrfs: let btrfs_return_cluster_to_free_space() return void 2020-07-27 12:55:21 +02:00
free-space-tree.c btrfs: fix possible free space tree corruption with online conversion 2021-02-03 23:28:40 +01:00
free-space-tree.h btrfs: rename btrfs_block_group_cache 2019-11-18 17:51:51 +01:00
inode-item.c
inode-map.c btrfs: make btrfs_delalloc_reserve_space take btrfs_inode 2020-07-27 12:55:36 +02:00
inode-map.h
inode.c btrfs: do not warn for free space inode in cow_file_range 2022-04-20 09:23:19 +02:00
ioctl.c fsnotify: invalidate dcache before IN_DELETE event 2022-02-01 17:25:48 +01:00
Kconfig btrfs: disable build on platforms having page size 256K 2021-07-14 16:55:56 +02:00
locking.c btrfs: add nesting tags to the locking helpers 2020-10-07 12:12:16 +02:00
locking.h btrfs: introduce BTRFS_NESTING_NEW_ROOT for adding new roots 2020-10-07 12:12:17 +02:00
lzo.c
Makefile Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
misc.h btrfs: rename tree_entry to rb_simple_node and export it 2020-05-25 11:25:19 +02:00
ordered-data.c btrfs: remove inode argument from btrfs_start_ordered_extent 2020-10-07 12:13:22 +02:00
ordered-data.h btrfs: remove inode argument from btrfs_start_ordered_extent 2020-10-07 12:13:22 +02:00
orphan.c
print-tree.c btrfs: print the actual offset in btrfs_root_name 2021-01-27 11:55:06 +01:00
print-tree.h btrfs: print the actual offset in btrfs_root_name 2021-01-27 11:55:06 +01:00
props.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
props.h
qgroup.c btrfs: qgroup: fix deadlock between rescan worker and remove qgroup 2022-03-08 19:09:38 +01:00
qgroup.h btrfs: export and rename qgroup_reserve_meta 2021-03-11 14:17:22 +01:00
raid56.c treewide: Change list_sort to use const pointers 2021-09-30 10:11:04 +02:00
raid56.h
rcu-string.h btrfs: rcu-string: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
reada.c btrfs: fix readahead hang and use-after-free after removing a device 2020-10-26 15:03:59 +01:00
ref-verify.c btrfs: ref-verify: fix memory leak in btrfs_ref_tree_mod 2020-11-05 13:03:39 +01:00
ref-verify.h
reflink.c btrfs: fix unexpected error path when reflinking an inline extent 2022-04-08 14:40:04 +02:00
reflink.h Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
relocation.c btrfs: convert logic BUG_ON()'s in replace_path to ASSERT()'s 2021-05-11 14:47:22 +02:00
root-tree.c btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling 2021-12-14 11:32:38 +01:00
scrub.c btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
send.c btrfs: send: in case of IO error log it 2022-02-23 12:00:58 +01:00
send.h btrfs: send: avoid copying file data 2020-10-07 12:13:17 +02:00
space-info.c btrfs: prevent __btrfs_dump_space_info() to underflow its free space 2021-09-30 10:11:00 +02:00
space-info.h btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-03-04 11:38:30 +01:00
struct-funcs.c btrfs: use unaligned helpers for stack and header set/get helpers 2020-10-07 12:13:23 +02:00
super.c btrfs: fix transaction leak and crash after RO remount caused by qgroup rescan 2021-01-19 18:27:24 +01:00
sysfs.c btrfs: sysfs: fix format string for some discard stats 2021-07-14 16:55:55 +02:00
sysfs.h btrfs: split and refactor btrfs_sysfs_remove_devices_dir 2020-10-07 12:12:21 +02:00
transaction.c btrfs: clear defrag status of a root if starting transaction fails 2021-07-14 16:55:40 +02:00
transaction.h btrfs: fix race between marking inode needs to be logged and log syncing 2021-09-03 10:09:28 +02:00
tree-checker.c btrfs: tree-checker: check item_size for dev_item 2022-03-02 11:42:45 +01:00
tree-checker.h
tree-defrag.c btrfs: remove unused btrfs_root::defrag_trans_start 2020-07-27 12:55:28 +02:00
tree-log.c btrfs: always log symlinks in full mode 2022-05-12 12:25:43 +02:00
tree-log.h btrfs: make fast fsyncs wait only for writeback 2020-10-07 12:06:56 +02:00
ulist.c
ulist.h
uuid-tree.c btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
volumes.c btrfs: mark resumed async balance as writing 2022-04-20 09:23:27 +02:00
volumes.h btrfs: fix lockdep warning due to seqcount_mutex on 32bit arch 2021-02-03 23:28:40 +01:00
xattr.c btrfs: fix warning when creating a directory with smack enabled 2021-03-09 11:11:12 +01:00
xattr.h
zlib.c btrfs: use larger zlib buffer for s390 hardware compression 2020-01-31 10:30:40 -08:00
zstd.c