diff mbox series

[v2,12/14] fs: xfs: Support atomic write for statx

Message ID 20240304130428.13026-13-john.g.garry@oracle.com
State New
Headers
Series block atomic writes for XFS |

Commit Message

John Garry March 4, 2024, 1:04 p.m. UTC 
  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. This is required by iomap
DIO.

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@oracle.com>
---
 fs/xfs/xfs_iops.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
diff mbox series

Patch

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index a0d77f5f512e..6316448083d2 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -546,6 +546,37 @@  xfs_stat_blksize(
 	return PAGE_SIZE;
 }
 
+static 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;
+	struct request_queue	*q = bdev->bd_queue;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_sb		*sbp = &mp->m_sb;
+	unsigned int		awu_min, awu_max;
+	unsigned int		extsz_bytes = XFS_FSB_TO_B(mp, extsz);
+
+	awu_min = queue_atomic_write_unit_min_bytes(q);
+	awu_max = queue_atomic_write_unit_max_bytes(q);
+
+	if (sbp->sb_blocksize > awu_max || awu_min > sbp->sb_blocksize ||
+	    !xfs_inode_atomicwrites(ip)) {
+		*unit_min = 0;
+		*unit_max = 0;
+		return;
+	}
+
+	/* Floor at FS block size */
+	*unit_min = max(sbp->sb_blocksize, awu_min);
+
+	*unit_max = min(extsz_bytes, awu_max);
+}
+
 STATIC int
 xfs_vn_getattr(
 	struct mnt_idmap	*idmap,
@@ -619,6 +650,13 @@  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);