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.
cc: stable@xxxxxxxxxxxxxxx
Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
fs/btrfs/inode.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b13c212b1bed..8db7455fee38 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9563,9 +9563,8 @@ 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);
/*
@@ -9799,9 +9798,8 @@ 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));
--
2.23.0
