All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Brian Foster <bfoster@redhat.com>
Cc: linux-xfs@vger.kernel.org, Dave Chinner <david@fromorbit.com>,
	Martin Svec <martin.svec@zoner.cz>
Subject: Re: [PATCH 1/3] xfs: fix up quotacheck buffer list error handling
Date: Thu, 6 Apr 2017 15:39:21 -0700	[thread overview]
Message-ID: <20170406223921.GB4864@birch.djwong.org> (raw)
In-Reply-To: <1487966001-63263-2-git-send-email-bfoster@redhat.com>

On Fri, Feb 24, 2017 at 02:53:19PM -0500, Brian Foster wrote:
> The quotacheck error handling of the delwri buffer list assumes the
> resident buffers are locked and doesn't clear the _XBF_DELWRI_Q flag
> on the buffers that are dequeued. This can lead to assert failures
> on buffer release and possibly other locking problems.
> 
> Update the error handling code to lock each buffer as it is removed
> from the buffer list and clear the delwri queue flag.
> 
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> ---
>  fs/xfs/xfs_buf.c | 2 ++
>  fs/xfs/xfs_qm.c  | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index ac3b4db..e566510 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -1078,6 +1078,8 @@ void
>  xfs_buf_unlock(
>  	struct xfs_buf		*bp)
>  {
> +	ASSERT(xfs_buf_islocked(bp));
> +
>  	XB_CLEAR_OWNER(bp);
>  	up(&bp->b_sema);
>  
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index b669b12..4ff993c 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -1387,6 +1387,8 @@ xfs_qm_quotacheck(
>  	while (!list_empty(&buffer_list)) {
>  		struct xfs_buf *bp =
>  			list_first_entry(&buffer_list, struct xfs_buf, b_list);
> +		xfs_buf_lock(bp);
> +		bp->b_flags &= ~_XBF_DELWRI_Q;
>  		list_del_init(&bp->b_list);
>  		xfs_buf_relse(bp);

Hmm, was this the only place we ever _buf_unlock'd an unlocked buffer?

--D

>  	}
> -- 
> 2.7.4
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2017-04-06 22:39 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-24 19:53 [PATCH v2 0/3] xfs: quotacheck vs. dquot reclaim deadlock Brian Foster
2017-02-24 19:53 ` [PATCH 1/3] xfs: fix up quotacheck buffer list error handling Brian Foster
2017-04-06 22:39   ` Darrick J. Wong [this message]
2017-04-07 12:02     ` Brian Foster
2017-04-07 18:20       ` Darrick J. Wong
2017-04-07 18:38         ` Brian Foster
2017-04-10  4:18   ` Dave Chinner
2017-04-10 14:13     ` Brian Foster
2017-02-24 19:53 ` [PATCH 2/3] xfs: push buffer of flush locked dquot to avoid quotacheck deadlock Brian Foster
2017-04-06 22:34   ` Darrick J. Wong
2017-04-07 12:06     ` Brian Foster
2017-04-07 20:07       ` Darrick J. Wong
2017-04-10 14:19         ` Brian Foster
2017-04-10  5:00   ` Dave Chinner
2017-04-10 14:15     ` Brian Foster
2017-04-10 23:55       ` Dave Chinner
2017-04-11 14:53         ` Brian Foster
2017-04-18  2:35           ` Dave Chinner
2017-04-18 13:55             ` Brian Foster
2017-04-19  2:46               ` Dave Chinner
2017-04-19 19:55                 ` Darrick J. Wong
2017-04-19 20:46                   ` Brian Foster
2017-04-21 12:18                     ` Brian Foster
2017-04-19 20:40                 ` Brian Foster
2017-04-11 12:50     ` Brian Foster
2017-02-24 19:53 ` [PATCH 3/3] [RFC] xfs: release buffer list after quotacheck buf reset Brian Foster

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=20170406223921.GB4864@birch.djwong.org \
    --to=darrick.wong@oracle.com \
    --cc=bfoster@redhat.com \
    --cc=david@fromorbit.com \
    --cc=linux-xfs@vger.kernel.org \
    --cc=martin.svec@zoner.cz \
    --subject='Re: [PATCH 1/3] xfs: fix up quotacheck buffer list error handling' \
    /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

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.