From: Christoph Hellwig <hch@infradead.org>
To: Amit Sahrawat <amit.sahrawat83@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>,
xfs masters <xfs-masters@oss.sgi.com>, xfs <xfs@oss.sgi.com>,
linux kernel <linux-kernel@vger.kernel.org>,
Alex Elder <aelder@sgi.com>
Subject: Re: [PATCH 1/1] xfs: serialise unaligned direct IOs
Date: Wed, 11 Jan 2012 06:34:28 -0500 [thread overview]
Message-ID: <20120111113428.GA14423@infradead.org> (raw)
In-Reply-To: <1325845990-5664-1-git-send-email-amit.sahrawat83@gmail.com>
> + /*
> + * In most cases the direct IO writes will be done with IOLOCK_SHARED
> + * allowing them to be done in parallel with reads and other direct IO
> + * writes. However,if the IO is not aligned to filesystem blocks, the
> + * direct IO layer needs to do sub-block zeroing and that requires
> + * serialisation against other direct IOs to the same block. In this
> + * case we need to serialise the submission of the unaligned IOs so
> + * that we don't get racing block zeroing in the dio layer.
> + * To avoid the problem with aio, we also need to wait for outstanding
> + * IOs to complete so that unwritten extent conversion is completed
> + * before we try to map the overlapping block. This is currently
> + * implemented by hitting it with a big hammer (i.e. xfs_ioend_wait()).
> + */
> +
This comment is lacking one level of indentation, that's because the old
kernel is missing the split of xfs_file_aio_write that reduces one level
of indentation.
Otherwise the backport looks fine, please send it to
stable@vger.kernel.org, with a [PATCH 0/0] coverletter stating it's for
2.6.35-stable.
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
prev parent reply other threads:[~2012-01-11 11:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-06 10:33 [PATCH 1/1] xfs: serialise unaligned direct IOs Amit Sahrawat
2012-01-11 11:34 ` Christoph Hellwig [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120111113428.GA14423@infradead.org \
--to=hch@infradead.org \
--cc=aelder@sgi.com \
--cc=amit.sahrawat83@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=xfs-masters@oss.sgi.com \
--cc=xfs@oss.sgi.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox