mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-03 23:58:05 +00:00
Code Issues Releases Wiki Activity

btrfs: don't double lock the subvol_sem for rename exchange

Browse source 
If we're rename exchanging two subvols we'll try to lock this lock
twice, which is bad.  Just lock once if either of the ino's are subvols.

Fixes: cdd1fedf82 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Josef Bacik 2019-11-19 13:59:20 -05:00 committed by David Sterba
parent db8fe64f9c
commit 943eb3bf25
1 changed files with 4 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
fs/btrfs/inode.c
View file

@ -9554,9 +9554,8 @@ static int btrfs_rename_exchange(struct inode *old_dir,
btrfs_init_log_ctx(&ctx_dest, new_inode);
/* close the race window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
if (old_ino == BTRFS_FIRST_FREE_OBJECTID ||
new_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
/*
@ -9790,9 +9789,8 @@ static int btrfs_rename_exchange(struct inode *old_dir,
ret = ret ? ret : ret2;
}
out_notrans:
if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
if (new_ino == BTRFS_FIRST_FREE_OBJECTID ||
old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
ASSERT(list_empty(&ctx_root.list));