From: Keith Busch <kbusch@xxxxxxxxxx>
If requested on a raw block device, report the maximum write hint the
block device supports.
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
---
block/bdev.c | 5 +++++
fs/stat.c | 1 +
include/linux/stat.h | 1 +
include/uapi/linux/stat.h | 3 ++-
4 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/block/bdev.c b/block/bdev.c
index 738e3c8457e7f..9a59f0c882170 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -1296,6 +1296,11 @@ void bdev_statx(struct path *path, struct kstat *stat,
stat->result_mask |= STATX_DIOALIGN;
}
+ if (request_mask & STATX_WRITE_HINT) {
+ stat->write_hint_max = bdev_max_write_hints(bdev);
+ stat->result_mask |= STATX_WRITE_HINT;
+ }
+
if (request_mask & STATX_WRITE_ATOMIC && bdev_can_atomic_write(bdev)) {
struct request_queue *bd_queue = bdev->bd_queue;
diff --git a/fs/stat.c b/fs/stat.c
index 41e598376d7e3..60bcd5c2e2a1d 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -704,6 +704,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
+ tmp.stx_write_hint_max = stat->write_hint_max;
return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}
diff --git a/include/linux/stat.h b/include/linux/stat.h
index 3d900c86981c5..48f0f64846a02 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -57,6 +57,7 @@ struct kstat {
u32 atomic_write_unit_min;
u32 atomic_write_unit_max;
u32 atomic_write_segments_max;
+ u32 write_hint_max;
};
/* These definitions are internal to the kernel for now. Mainly used by nfsd. */
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 887a252864416..10f5622c21113 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -132,7 +132,7 @@ struct statx {
__u32 stx_atomic_write_unit_max; /* Max atomic write unit in bytes */
/* 0xb0 */
__u32 stx_atomic_write_segments_max; /* Max atomic write segment count */
- __u32 __spare1[1];
+ __u32 stx_write_hint_max;
/* 0xb8 */
__u64 __spare3[9]; /* Spare space for future expansion */
/* 0x100 */
@@ -164,6 +164,7 @@ struct statx {
#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */
#define STATX_SUBVOL 0x00008000U /* Want/got stx_subvol */
#define STATX_WRITE_ATOMIC 0x00010000U /* Want/got atomic_write_* fields */
+#define STATX_WRITE_HINT 0x00020000U /* Want/got write_hint_max */
#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */
--
2.43.5
