[PATCH 23/43] xfs: fix xfs_get_extsz_hint behavior with realtime alwayscow files

Darrick J. Wong
2024-12-13T01:16:14Z

From: Darrick J. Wong <djwong@kernel.org>

Currently, we (ab)use xfs_get_extsz_hint so that it always returns a
nonzero value for realtime files. This apparently was done to disable
delayed allocation for realtime files.

However, once we enable realtime reflink, we can also turn on the
alwayscow flag to force CoW writes to realtime files. In this case, the
logic will incorrectly send the write through the delalloc write path.

Fix this by adjusting the logic slightly.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_bmap.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index d63713630236e7..ae3d33d6076102 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -6500,9 +6500,8 @@ xfs_get_extsz_hint(
* No point in aligning allocations if we need to COW to actually
* write to them.
*/
- if (xfs_is_always_cow_inode(ip))
- return 0;
- if ((ip->i_diflags & XFS_DIFLAG_EXTSIZE) && ip->i_extsize)
+ if (!xfs_is_always_cow_inode(ip) &&
+ (ip->i_diflags & XFS_DIFLAG_EXTSIZE) && ip->i_extsize)
return ip->i_extsize;
if (XFS_IS_REALTIME_INODE(ip) &&
ip->i_mount->m_sb.sb_rextsize > 1)