[PATCH 5.4 052/214] btrfs: file: reserve qgroup space after the hole punch range is locked

Greg Kroah-Hartman
2020-09-01T16:41:02Z

From: Qu Wenruo <wqu@suse.com>

[ Upstream commit a7f8b1c2ac21bf081b41264c9cfd6260dffa6246 ]

The incoming qgroup reserved space timing will move the data reservation
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 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.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/file.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 3cfbccacef7fd..a02c44b6a2be5 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3130,14 +3130,14 @@ reserve_space:
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),
--
2.25.1