[v2,3/5] btrfs: file: reserve qgroup space after the hole punch range locked

Commit Message

Qu Wenruo June 10, 2020, 12:57 a.m. UTC

The incoming qgroup reserved space timing will move the data reserve to
ordered extent completely.

However in btrfs_punch_hole_lock_range() will call
btrfs_invalidate_page(), which will clear QGROUP_RESERVED bit for the
range.

In current stage it's OK, but if we're making ordered extents to handle
the reserved space, then btrfs_punch_hole_lock_range() can clear the
QGROUP_RESERVED bit before we submit ordered extent, leading to qgroup
reserved space leakage.

So here change the timing to make reserve data space after
btrfs_punch_hole_lock_range().
The new timing is fine for either current code or the new code.

Signed-off-by: Qu Wenruo <[e-mail]>
---
 fs/btrfs/file.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index fde125616687..3f4b8f7666a9 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3188,14 +3188,14 @@  static int btrfs_zero_range(struct inode *inode,
 		if (ret < 0)
 			goto out;
 		space_reserved = true;
-		ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
-						alloc_start, bytes_to_reserve);
-		if (ret)
-			goto out;
 		ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
 						  &cached_state);
 		if (ret)
 			goto out;
+		ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
+						alloc_start, bytes_to_reserve);
+		if (ret)
+			goto out;
 		ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
 						alloc_end - alloc_start,
 						i_blocksize(inode),