5.4-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
[ Upstream commit 157501b0469969fc1ba53add5049575aadd79d80 ]
We are setting the parent directory's last_unlink_trans directly which may result in a concurrent task starting to log the directory not see the update and therefore can log the directory after we removed a child directory which had a snapshot within instead of falling back to a transaction commit. Replaying such a log tree would result in a mount failure since we can't currently delete snapshots (and subvolumes) during log replay. This is the type of failure described in commit 1ec9a1ae1e30 ("Btrfs: fix unreplayable log after snapshot delete + parent dir fsync").
Fix this by using btrfs_record_snapshot_destroy() which updates the last_unlink_trans field while holding the inode's log_mutex lock.
Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 8f92f998dc37b..757111e529948 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4772,7 +4772,7 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) * deletes for directory foo. */ if (BTRFS_I(inode)->last_unlink_trans >= trans->transid) - BTRFS_I(dir)->last_unlink_trans = BTRFS_I(inode)->last_unlink_trans; + btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { err = btrfs_unlink_subvol(trans, dir, dentry);