[RFC PATCH 6/8] xfs: Report atomic write min and max for buf io as well
From: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Date: 2025-11-12 11:07:39
Also in:
linux-block, linux-ext4, linux-fsdevel, linux-mm, linux-xfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
Now that we can reliably perform a HW based single block buffered atomic write for page size == blocksize, start advertising it in XFS. Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> --- fs/xfs/xfs_iops.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f036c46b19c5..67d370947d95 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c@@ -604,9 +604,10 @@ xfs_get_atomic_write_min( struct xfs_inode *ip, bool is_dio) { - if (is_dio) { - struct xfs_mount *mp = ip->i_mount; + struct xfs_mount *mp = ip->i_mount; + uint32_t bs = mp->m_sb.sb_blocksize; + if (is_dio) { /* * If we can complete an atomic write via atomic out of place writes, * then advertise a minimum size of one fsblock. Without this
@@ -618,10 +619,15 @@ xfs_get_atomic_write_min( */ if (xfs_inode_can_hw_atomic_write(ip) || xfs_inode_can_sw_atomic_write(ip)) - return mp->m_sb.sb_blocksize; + return bs; } + /* + * Buffered IO only supports hw single block atomic writes and bs == ps + * configurations. + */ + if (xfs_inode_can_hw_atomic_write(ip) && bs == PAGE_SIZE) + return bs; - /* buffered IO not supported yet so return 0 right away */ return 0; }
@@ -630,7 +636,8 @@ xfs_get_atomic_write_max( struct xfs_inode *ip, bool is_dio) { - struct xfs_mount *mp = ip->i_mount; + struct xfs_mount *mp = ip->i_mount; + uint32_t bs = mp->m_sb.sb_blocksize; if (is_dio) { /*
@@ -640,7 +647,7 @@ xfs_get_atomic_write_max( */ if (!xfs_inode_can_sw_atomic_write(ip)) { if (xfs_inode_can_hw_atomic_write(ip)) - return mp->m_sb.sb_blocksize; + return bs; return 0; }
@@ -653,8 +660,13 @@ xfs_get_atomic_write_max( return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_RTG].awu_max); return XFS_FSB_TO_B(mp, mp->m_groups[XG_TYPE_AG].awu_max); } + /* + * Buffered IO only supports hw single block atomic writes and bs == ps + * configurations. + */ + if (xfs_inode_can_hw_atomic_write(ip) && bs == PAGE_SIZE) + return bs; - /* buffered IO not supported yet so return 0 right away */ return 0; }
@@ -679,7 +691,7 @@ xfs_get_atomic_write_max_opt( return min(awu_max, xfs_inode_buftarg(ip)->bt_awu_max); } - /* buffered IO not supported yet so return 0 right away */ + /* buffered IO for now only supports 1 filesyste block so max_opt is 0 */ return 0; }
--
2.51.0