[PATCH] btrfs: Unlock extents in btrfs_zero_range in case of errors

[Nikolay Borisov]

If btrfs_qgroup_reserve_data returns an error (i.e quota limit reached)
the handling logic directly goes to the 'out' label without first
unlocking the extent range between lockstart, lockend. This results in
deadlocks as processes try to lock the same extent.

Fixes: a7f8b1c2ac21 ("btrfs: file: reserve qgroup space after the hole punch 
range is locked")
Signed-off-by: Nikolay Borisov <nbori...@suse.com>
---
 fs/btrfs/file.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 1e68349c3884..af0253473508 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3259,8 +3259,11 @@ static int btrfs_zero_range(struct inode *inode,
                        goto out;
                ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
                                                alloc_start, bytes_to_reserve);
-               if (ret)
+               if (ret) {
+                       unlock_extent_cached(&BTRFS_I(inode)->io_tree, 
lockstart,
+                                            lockend, &cached_state);
                        goto out;
+               }
                ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
                                                alloc_end - alloc_start,
                                                i_blocksize(inode),
-- 
2.25.1