[PATCH 6.6.y] btrfs: do not free data reservation in fallback from inline due to -ENOSPC

[Li hongliang]

From: Filipe Manana <fdmanana@xxxxxxxx>

[ Upstream commit f8da41de0bff9eb1d774a7253da0c9f637c4470a ]

If we fail to create an inline extent due to -ENOSPC, we will attempt to
go through the normal COW path, reserve an extent, create an ordered
extent, etc. However we were always freeing the reserved qgroup data,
which is wrong since we will use data. Fix this by freeing the reserved
qgroup data in __cow_file_range_inline() only if we are not doing the
fallback (ret is <= 0).

Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[ Minor conflict resolved. ]
Signed-off-by: Li hongliang <1468888505@xxxxxxx>
---
 fs/btrfs/inode.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index cf39f52fc048..3ae77a836588 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -691,8 +691,12 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
 	 * it won't count as data extent, free them directly here.
 	 * And at reserve time, it's always aligned to page size, so
 	 * just free one page here.
+	 *
+	 * If we fallback to non-inline (ret == 1) due to -ENOSPC, then we need
+	 * to keep the data reservation.
 	 */
-	btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE, NULL);
+	if (ret <= 0)
+		btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE, NULL);
 	btrfs_free_path(path);
 	if (trans)
 		btrfs_end_transaction(trans);
-- 
2.34.1