[PATCH v9 06/15] xfs: allow block allocator to take an alignment hint
From: John Garry <john.g.garry@oracle.com>
Date: 2025-04-25 16:47:56
Also in:
linux-block, linux-ext4, linux-fsdevel, linux-xfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
Add a BMAPI flag to provide a hint to the block allocator to align extents according to the extszhint. This will be useful for atomic writes to ensure that we are not being allocated extents which are not suitable (for atomic writes). Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: John Garry <john.g.garry@oracle.com> Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> --- fs/xfs/libxfs/xfs_bmap.c | 5 +++++ fs/xfs/libxfs/xfs_bmap.h | 6 +++++- 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 63255820b58a..d954f9b8071f 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c@@ -3312,6 +3312,11 @@ xfs_bmap_compute_alignments( align = xfs_get_cowextsz_hint(ap->ip); else if (ap->datatype & XFS_ALLOC_USERDATA) align = xfs_get_extsz_hint(ap->ip); + + /* Try to align start block to any minimum allocation alignment */ + if (align > 1 && (ap->flags & XFS_BMAPI_EXTSZALIGN)) + args->alignment = align; + if (align) { if (xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, align, 0, ap->eof, 0, ap->conv, &ap->offset,
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index b4d9c6e0f3f9..d5f2729305fa 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h@@ -87,6 +87,9 @@ struct xfs_bmalloca { /* Do not update the rmap btree. Used for reconstructing bmbt from rmapbt. */ #define XFS_BMAPI_NORMAP (1u << 10) +/* Try to align allocations to the extent size hint */ +#define XFS_BMAPI_EXTSZALIGN (1u << 11) + #define XFS_BMAPI_FLAGS \ { XFS_BMAPI_ENTIRE, "ENTIRE" }, \ { XFS_BMAPI_METADATA, "METADATA" }, \
@@ -98,7 +101,8 @@ struct xfs_bmalloca { { XFS_BMAPI_REMAP, "REMAP" }, \ { XFS_BMAPI_COWFORK, "COWFORK" }, \ { XFS_BMAPI_NODISCARD, "NODISCARD" }, \ - { XFS_BMAPI_NORMAP, "NORMAP" } + { XFS_BMAPI_NORMAP, "NORMAP" },\ + { XFS_BMAPI_EXTSZALIGN, "EXTSZALIGN" } static inline int xfs_bmapi_aflag(int w)
--
2.31.1