From: Dave Chinner <david@fromorbit.com>
To: Jeff Liu <jeff.liu@oracle.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH v7 3/4] xfs: xfs_seek_data() refinement with unwritten extents check up from page cache
Date: Tue, 21 Aug 2012 09:16:07 +1000 [thread overview]
Message-ID: <20120820231607.GK19235@dastard> (raw)
In-Reply-To: <5028FC39.5060809@oracle.com>
On Mon, Aug 13, 2012 at 09:08:09PM +0800, Jeff Liu wrote:
> Improve xfs_seek_data() to search data offset from page cache for unwritten extents.
>
> Signed-off-by: Jie Liu <jeff.liu@oracle.com>
One minor addition, otherwise
Reviewed-by: Dave Chinner <dchinner@redhat.com>
....
> +
> + /*
> + * map[0] is hole or its an unwritten extent but
> + * without data in page cache. Probably means that
> + * we are reading after EOF if nothing in map[1].
> + */
> if (nmap == 1) {
> error = ENXIO;
> goto out_unlock;
> }
>
> - offset = max_t(loff_t, start,
> - XFS_FSB_TO_B(mp, map[1].br_startoff));
> + /*
> + * Nothing was found, proceed to the next round of search
> + * if reading offset not beyond or hit EOF.
> + */
ASSERT(i > 1);
> + fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
> + start = XFS_FSB_TO_B(mp, fsbno);
> + if (start >= isize) {
> + error = ENXIO;
> + goto out_unlock;
> + }
> }
>
> +out:
> if (offset != file->f_pos)
> file->f_pos = offset;
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
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next prev parent reply other threads:[~2012-08-20 23:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-13 13:08 [PATCH v7 3/4] xfs: xfs_seek_data() refinement with unwritten extents check up from page cache Jeff Liu
2012-08-20 18:21 ` Mark Tinguely
2012-08-20 23:16 ` Dave Chinner [this message]
2012-08-21 5:07 ` Jie Liu
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