Re: [PATCH 1/3] xfs: fix the calculation of length and end

From: Darrick J. Wong
Date: Wed Sep 14 2022 - 14:13:43 EST


On Fri, Sep 02, 2022 at 10:35:59AM +0000, Shiyang Ruan wrote:
> The end should be start + length - 1. Also fix the calculation of the
> length when seeking for intersection of notify range and device.
>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>

Looks correct to me,
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>

--D

> ---
> fs/xfs/xfs_notify_failure.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/xfs/xfs_notify_failure.c b/fs/xfs/xfs_notify_failure.c
> index c4078d0ec108..3830f908e215 100644
> --- a/fs/xfs/xfs_notify_failure.c
> +++ b/fs/xfs/xfs_notify_failure.c
> @@ -114,7 +114,7 @@ xfs_dax_notify_ddev_failure(
> int error = 0;
> xfs_fsblock_t fsbno = XFS_DADDR_TO_FSB(mp, daddr);
> xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, fsbno);
> - xfs_fsblock_t end_fsbno = XFS_DADDR_TO_FSB(mp, daddr + bblen);
> + xfs_fsblock_t end_fsbno = XFS_DADDR_TO_FSB(mp, daddr + bblen - 1);
> xfs_agnumber_t end_agno = XFS_FSB_TO_AGNO(mp, end_fsbno);
>
> error = xfs_trans_alloc_empty(mp, &tp);
> @@ -210,7 +210,7 @@ xfs_dax_notify_failure(
> ddev_end = ddev_start + bdev_nr_bytes(mp->m_ddev_targp->bt_bdev) - 1;
>
> /* Ignore the range out of filesystem area */
> - if (offset + len < ddev_start)
> + if (offset + len - 1 < ddev_start)
> return -ENXIO;
> if (offset > ddev_end)
> return -ENXIO;
> @@ -222,8 +222,8 @@ xfs_dax_notify_failure(
> len -= ddev_start - offset;
> offset = 0;
> }
> - if (offset + len > ddev_end)
> - len -= ddev_end - offset;
> + if (offset + len - 1 > ddev_end)
> + len -= offset + len - 1 - ddev_end;
>
> return xfs_dax_notify_ddev_failure(mp, BTOBB(offset), BTOBB(len),
> mf_flags);
> --
> 2.37.2
>