[PATCH v2 6/7] xfs: Add RT atomic write unit max to xfs_mount

John Garry
2024-12-10T13:00:35Z

rtvol guarantees alloc unit alignment through rt_extsize. As such, it is
possible to atomically write multiple FS blocks in a rtvol (up to
rt_extsize).

Add a member to xfs_mount to hold the pre-calculated atomic write unit max.

The value in rt_extsize does not need to be a power-of-2, so find the
largest power-of-2 evenly divisible into rt_extsize.

Signed-off-by: John Garry <john.g.garry@oracle.com>
---
fs/xfs/libxfs/xfs_sb.c | 3 +++
fs/xfs/xfs_mount.h | 1 +
fs/xfs/xfs_rtalloc.c | 25 +++++++++++++++++++++++++
fs/xfs/xfs_rtalloc.h | 4 ++++
4 files changed, 33 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index a809513a290c..f59d48f6557c 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -25,6 +25,7 @@
#include "xfs_da_format.h"
#include "xfs_health.h"
#include "xfs_ag.h"
+#include "xfs_rtalloc.h"
#include "xfs_rtbitmap.h"
#include "xfs_exchrange.h"
#include "xfs_rtgroup.h"
@@ -1148,6 +1149,8 @@ xfs_sb_mount_rextsize(
rgs->blklog = 0;
rgs->blkmask = (uint64_t)-1;
}
+
+ xfs_rt_awu_update(mp);
}

/* Update incore sb rt extent size, then recompute the cached rt geometry. */
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index db9dade7d22a..8cd161238893 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -191,6 +191,7 @@ typedef struct xfs_mount {
bool m_fail_unmount;
bool m_finobt_nores; /* no per-AG finobt resv. */
bool m_update_sb; /* sb needs update in mount */
+ unsigned int m_rt_awu_max; /* rt atomic write unit max */

/*
* Bitsets of per-fs metadata that have been checked and/or are sick.
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 0cb534d71119..3551f09fd2cb 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -735,6 +735,30 @@ xfs_rtginode_ensure(
return xfs_rtginode_create(rtg, type, true);
}

+void
+xfs_rt_awu_update(
+ struct xfs_mount *mp)
+{
+ unsigned int rsize = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize);
+ unsigned int awu_max;
+
+ if (is_power_of_2(rsize)) {
+ mp->m_rt_awu_max = rsize;
+ return;
+ }
+
+ /*
+ * Find highest power-of-2 evenly divisible into sb_rextsize
+ */
+ awu_max = mp->m_sb.sb_blocksize;
+ while (1) {
+ if (rsize % (awu_max * 2))
+ break;
+ awu_max *= 2;
+ }
+ mp->m_rt_awu_max = awu_max;
+}
+
static struct xfs_mount *
xfs_growfs_rt_alloc_fake_mount(
const struct xfs_mount *mp,
@@ -969,6 +993,7 @@ xfs_growfs_rt_bmblock(
*/
mp->m_rsumlevels = nmp->m_rsumlevels;
mp->m_rsumblocks = nmp->m_rsumblocks;
+ mp->m_rt_awu_max = nmp->m_rt_awu_max;

/*
* Recompute the growfsrt reservation from the new rsumsize.
diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index 8e2a07b8174b..fcb7bb3df470 100644
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -42,6 +42,10 @@ xfs_growfs_rt(
struct xfs_mount *mp, /* file system mount structure */
xfs_growfs_rt_t *in); /* user supplied growfs struct */

+void
+xfs_rt_awu_update(
+ struct xfs_mount *mp);
+
int xfs_rtalloc_reinit_frextents(struct xfs_mount *mp);
#else
# define xfs_growfs_rt(mp,in) (-ENOSYS)
--
2.31.1