public inbox for linux-xfs@vger.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: Lachlan McIlroy <lmcilroy@redhat.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH] xfs_file_last_byte() needs to acquire ilock
Date: Fri, 24 Apr 2009 13:52:24 -0400	[thread overview]
Message-ID: <20090424175224.GB32198@infradead.org> (raw)
In-Reply-To: <1624785772.3251240539480564.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com>

On Thu, Apr 23, 2009 at 10:18:00PM -0400, Lachlan McIlroy wrote:
> We had some systems crash with this stack:
> 
> [<a00000010000cb20>] ia64_leave_kernel+0x0/0x280
> [<a00000021291ca00>] xfs_bmbt_get_startoff+0x0/0x20 [xfs]
> [<a0000002129080b0>] xfs_bmap_last_offset+0x210/0x280 [xfs]
> [<a00000021295b010>] xfs_file_last_byte+0x70/0x1a0 [xfs]
> [<a00000021295b200>] xfs_itruncate_start+0xc0/0x1a0 [xfs]
> [<a0000002129935f0>] xfs_inactive_free_eofblocks+0x290/0x460 [xfs]
> [<a000000212998fb0>] xfs_release+0x1b0/0x240 [xfs]
> [<a0000002129ad930>] xfs_file_release+0x70/0xa0 [xfs]
> [<a000000100162ea0>] __fput+0x1a0/0x420
> [<a000000100163160>] fput+0x40/0x60
> 
> The problem here is that xfs_file_last_byte() does not acquire the
> inode lock and can therefore race with another thread that is modifying
> the extext list.  While xfs_bmap_last_offset() is trying to lookup
> what was the last extent some extents were merged and the extent list
> shrunk so the index we lookup is now beyond the end of the extent list
> and potentially in a freed buffer.

Looks good.


Reviewed-by: Christoph Hellwig <hch@lst.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

  parent reply	other threads:[~2009-04-24 17:52 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-24  2:18 [PATCH] xfs_file_last_byte() needs to acquire ilock Lachlan McIlroy
2009-04-24  2:49 ` Eric Sandeen
2009-04-24  4:25 ` Felix Blyakher
2009-04-24 17:52 ` Christoph Hellwig [this message]
2009-04-24 19:30 ` Felix Blyakher
     [not found] <344266684.4811240544710893.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com>
2009-04-24  3:46 ` Lachlan McIlroy
2009-04-24 21:42   ` Felix Blyakher
     [not found] <869141559.5581240549433363.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com>
2009-04-24  5:07 ` Lachlan McIlroy
     [not found] <1913401106.233581240891740242.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com>
2009-04-28  4:11 ` Lachlan McIlroy
2009-04-28  5:03   ` Felix Blyakher
2009-04-28  5:33     ` Lachlan McIlroy
2009-04-28 14:34       ` Felix Blyakher

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=20090424175224.GB32198@infradead.org \
    --to=hch@infradead.org \
    --cc=lmcilroy@redhat.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