2024-04-25 11:40:05

by Pankaj Raghav (Samsung)

Subject: [PATCH v4 09/11] xfs: expose block size in stat

From: Pankaj Raghav <[email protected]>

For block size larger than page size, the unit of efficient IO is
the block size, not the page size. Leaving stat() to report
PAGE_SIZE as the block size causes test programs like fsx to issue
illegal ranges for operations that require block size alignment
(e.g. fallocate() insert range). Hence update the preferred IO size
to reflect the block size in this case.

This change is based on a patch originally from Dave Chinner.[1]

[1] https://lwn.net/ml/linux-fsdevel/[email protected]/

Signed-off-by: Pankaj Raghav <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
---
fs/xfs/xfs_iops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 66f8c47642e8..77b198a33aa1 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -543,7 +543,7 @@ xfs_stat_blksize(
return 1U << mp->m_allocsize_log;
}

- return PAGE_SIZE;
+ return max_t(uint32_t, PAGE_SIZE, mp->m_sb.sb_blocksize);
}

STATIC int
--
2.34.1

2024-04-26 15:20:42

by Darrick J. Wong

Subject: Re: [PATCH v4 09/11] xfs: expose block size in stat

On Thu, Apr 25, 2024 at 01:37:44PM +0200, Pankaj Raghav (Samsung) wrote:
> From: Pankaj Raghav <[email protected]>
>
> For block size larger than page size, the unit of efficient IO is
> the block size, not the page size. Leaving stat() to report
> PAGE_SIZE as the block size causes test programs like fsx to issue
> illegal ranges for operations that require block size alignment
> (e.g. fallocate() insert range). Hence update the preferred IO size
> to reflect the block size in this case.
>
> This change is based on a patch originally from Dave Chinner.[1]
>
> [1] https://lwn.net/ml/linux-fsdevel/[email protected]/
>
> Signed-off-by: Pankaj Raghav <[email protected]>
> Signed-off-by: Luis Chamberlain <[email protected]>

Seems reasonable to me...
Reviewed-by: Darrick J. Wong <[email protected]>

--D

> ---
> fs/xfs/xfs_iops.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index 66f8c47642e8..77b198a33aa1 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -543,7 +543,7 @@ xfs_stat_blksize(
> return 1U << mp->m_allocsize_log;
> }
>
> - return PAGE_SIZE;
> + return max_t(uint32_t, PAGE_SIZE, mp->m_sb.sb_blocksize);
> }
>
> STATIC int
> --
> 2.34.1
>
>