On 01/07/2025 19:08, Darrick J. Wong wrote:
From: Darrick J. Wong <djwong@xxxxxxxxxx>
Try to align the AG size to the maximum hardware atomic write unit so
that we can give users maximum flexibility in choosing an RWF_ATOMIC
write size.
Regardless of comments below, FWIW:
Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>
Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
libxfs/topology.h | 6 ++++--
libxfs/topology.c | 36 ++++++++++++++++++++++++++++++++++++
mkfs/xfs_mkfs.c | 48 +++++++++++++++++++++++++++++++++++++++++++-----
3 files changed, 83 insertions(+), 7 deletions(-)
diff --git a/libxfs/topology.h b/libxfs/topology.h
index 207a8a7f150556..f0ca65f3576e92 100644
--- a/libxfs/topology.h
+++ b/libxfs/topology.h
@@ -13,8 +13,10 @@
struct device_topology {
int logical_sector_size; /* logical sector size */
int physical_sector_size; /* physical sector size */
- int sunit; /* stripe unit */
- int swidth; /* stripe width */
+ int sunit; /* stripe unit */
+ int swidth; /* stripe width */
+ int awu_min; /* min atomic write unit in bbcounts */
awu_min is not really used, but, like the kernel code does, I suppose
useful to store it
+ int awu_max; /* max atomic write unit in bbcounts */
};
struct fs_topology {
diff --git a/libxfs/topology.c b/libxfs/topology.c
index 96ee74b61b30f5..7764687beac000 100644
--- a/libxfs/topology.c
+++ b/libxfs/topology.c
@@ -4,11 +4,18 @@
* All Rights Reserved.
*/
+#ifdef OVERRIDE_SYSTEM_STATX
+#define statx sys_statx
+#endif
+#include <fcntl.h>
+#include <sys/stat.h>
+
#include "libxfs_priv.h"
#include "libxcmd.h"
#include <blkid/blkid.h>
#include "xfs_multidisk.h"
#include "libfrog/platform.h"
+#include "libfrog/statx.h"
#define TERABYTES(count, blog) ((uint64_t)(count) << (40 - (blog)))
#define GIGABYTES(count, blog) ((uint64_t)(count) << (30 - (blog)))
@@ -278,6 +285,34 @@ blkid_get_topology(
device);
}
+static void
+get_hw_atomic_writes_topology(
+ struct libxfs_dev *dev,
+ struct device_topology *dt)
+{
+ struct statx sx;
+ int fd;
+ int ret;
+
+ fd = open(dev->name, O_RDONLY);
+ if (fd < 0)
+ return;
+
+ ret = statx(fd, "", AT_EMPTY_PATH, STATX_WRITE_ATOMIC, &sx);
+ if (ret)
+ goto out_close;
+
+ if (!(sx.stx_mask & STATX_WRITE_ATOMIC))
+ goto out_close;
+
+ dt->awu_min = sx.stx_atomic_write_unit_min >> 9;
+ dt->awu_max = max(sx.stx_atomic_write_unit_max_opt,
+ sx.stx_atomic_write_unit_max) >> 9;
for a bdev, stx_atomic_write_unit_max_opt should be zero
However, I suppose some bdev could have hybrid atomic write support,
just like xfs, so what you are doing looks good
