diff options
| author | Josef Bacik <josef@toxicpanda.com> | 2019-11-19 13:59:20 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-04 13:40:12 +0100 |
| commit | 85562d8aac9e5264514d6549ee0b6cac5640b0dc (patch) | |
| tree | 1d940c38594b63a10a95844b41575076abb3650e /fs/btrfs | |
| parent | 795b4ef803e29c5922927dbc78732b98a0e28a73 (diff) | |
btrfs: don't double lock the subvol_sem for rename exchange
[ Upstream commit 943eb3bf25f4a7b745dd799e031be276aa104d82 ]
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: cdd1fedf8261 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/inode.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 80937c5ca477..bb8863958ac0 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9597,9 +9597,8 @@ static int btrfs_rename_exchange(struct inode *old_dir, return -EXDEV; /* close the race window with snapshot create/destroy ioctl */ - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) - down_read(&root->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(&dest->fs_info->subvol_sem); /* @@ -9785,9 +9784,8 @@ out_fail: ret2 = btrfs_end_transaction(trans, root); ret = ret ? ret : ret2; out_notrans: - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) - up_read(&dest->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(&root->fs_info->subvol_sem); return ret; |