diff mbox series

[v5,5/7] xfs: Support atomic write for statx

Message ID 20240817094800.776408-6-john.g.garry@oracle.com (mailing list archive)
State New, archived
Headers show
Series block atomic writes for xfs | expand

Commit Message

John Garry Aug. 17, 2024, 9:47 a.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 | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

Comments

Darrick J. Wong Aug. 21, 2024, 5:09 p.m. UTC | #1
On Sat, Aug 17, 2024 at 09:47:58AM +0000, John Garry wrote:
> 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 | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index 6e017aa6f61d..c20becd3a7c9 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -570,6 +570,27 @@ 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)
> +{
> +	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
> +	struct xfs_mount	*mp = ip->i_mount;
> +	struct xfs_sb		*sbp = &mp->m_sb;
> +	unsigned int		extsz_bytes = XFS_FSB_TO_B(mp, ip->i_extsize);
> +
> +	if (!xfs_inode_has_atomicwrites(ip)) {

Here's where you might want to check that DIFLAG2_ATOMICWRITES is sset
and stripe alignment still makes sense before handing out nonzero
STATX_WRITE_ATOMIC information.  The rest of the patch looks ok to me.

--D

> +		*unit_min = 0;
> +		*unit_max = 0;
> +		return;
> +	}
> +
> +	*unit_min = sbp->sb_blocksize;
> +	*unit_max = min(target->bt_bdev_awu_max, extsz_bytes);
> +}
> +
>  STATIC int
>  xfs_vn_getattr(
>  	struct mnt_idmap	*idmap,
> @@ -643,6 +664,13 @@ 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);
> -- 
> 2.31.1
> 
>
diff mbox series

Patch

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 6e017aa6f61d..c20becd3a7c9 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -570,6 +570,27 @@  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)
+{
+	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_sb		*sbp = &mp->m_sb;
+	unsigned int		extsz_bytes = XFS_FSB_TO_B(mp, ip->i_extsize);
+
+	if (!xfs_inode_has_atomicwrites(ip)) {
+		*unit_min = 0;
+		*unit_max = 0;
+		return;
+	}
+
+	*unit_min = sbp->sb_blocksize;
+	*unit_max = min(target->bt_bdev_awu_max, extsz_bytes);
+}
+
 STATIC int
 xfs_vn_getattr(
 	struct mnt_idmap	*idmap,
@@ -643,6 +664,13 @@  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);