Support providing info on atomic write unit min and max for an inode.
For simplicity, currently we limit the min at the FS block size, but a
lower limit could be supported in future.
The atomic write unit min and max is limited by the guaranteed extent
alignment for the inode.
Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
fs/xfs/xfs_iops.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_iops.h | 4 ++++
2 files changed, 49 insertions(+)
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index a0d77f5f512e..0890d2f70f4d 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -546,6 +546,44 @@ xfs_stat_blksize(
return PAGE_SIZE;
}
+void xfs_get_atomic_write_attr(
+ struct xfs_inode *ip,
+ unsigned int *unit_min,
+ unsigned int *unit_max)
+{
+ xfs_extlen_t extsz = xfs_get_extsz(ip);
+ struct xfs_buftarg *target = xfs_inode_buftarg(ip);
+ struct block_device *bdev = target->bt_bdev;
+ unsigned int awu_min, awu_max, align;
+ struct request_queue *q = bdev->bd_queue;
+ struct xfs_mount *mp = ip->i_mount;
+
+ /*
+ * Convert to multiples of the BLOCKSIZE (as we support a minimum
+ * atomic write unit of BLOCKSIZE).
+ */
+ awu_min = queue_atomic_write_unit_min_bytes(q);
+ awu_max = queue_atomic_write_unit_max_bytes(q);
+
+ awu_min &= ~mp->m_blockmask;
+ awu_max &= ~mp->m_blockmask;
+
+ align = XFS_FSB_TO_B(mp, extsz);
+
+ if (!awu_max || !xfs_inode_atomicwrites(ip) || !align ||
+ !is_power_of_2(align)) {
+ *unit_min = 0;
+ *unit_max = 0;
+ } else {
+ if (awu_min)
+ *unit_min = min(awu_min, align);
+ else
+ *unit_min = mp->m_sb.sb_blocksize;
+
+ *unit_max = min(awu_max, align);
+ }
+}
+
STATIC int
xfs_vn_getattr(
struct mnt_idmap *idmap,
@@ -619,6 +657,13 @@ xfs_vn_getattr(
stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
stat->dio_offset_align = bdev_logical_block_size(bdev);
}
+ if (request_mask & STATX_WRITE_ATOMIC) {
+ unsigned int unit_min, unit_max;
+
+ xfs_get_atomic_write_attr(ip, &unit_min, &unit_max);
+ generic_fill_statx_atomic_writes(stat,
+ unit_min, unit_max);
+ }
fallthrough;
default:
stat->blksize = xfs_stat_blksize(ip);
diff --git a/fs/xfs/xfs_iops.h b/fs/xfs/xfs_iops.h
index 7f84a0843b24..76dd4c3687aa 100644
--- a/fs/xfs/xfs_iops.h
+++ b/fs/xfs/xfs_iops.h
@@ -19,4 +19,8 @@ int xfs_vn_setattr_size(struct mnt_idmap *idmap,
int xfs_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr);
+void xfs_get_atomic_write_attr(struct xfs_inode *ip,
+ unsigned int *unit_min,
+ unsigned int *unit_max);
+
#endif /* __XFS_IOPS_H__ */
--
2.31.1
