From: Dave Chinner <david@fromorbit.com>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Jiaying Zhang <jiayingz@google.com>, linux-ext4@vger.kernel.org
Subject: Re: [URGENT PATCH] ext4: fix potential deadlock in ext4_evict_inode()
Date: Fri, 26 Aug 2011 18:44:03 +1000 [thread overview]
Message-ID: <20110826084403.GA3162@dastard> (raw)
In-Reply-To: <20110826073507.GZ3162@dastard>
On Fri, Aug 26, 2011 at 05:35:07PM +1000, Dave Chinner wrote:
> On Thu, Aug 25, 2011 at 11:33:44PM -0400, Theodore Ts'o wrote:
> >
> > Note: this will probably need to be sent to Linus as an emergency
> > bugfix ASAP, since it was introduced in 3.1-rc1, so it represents a
> > regression.
>
> It doesn't appear to be a bug. All of the new ext4 lockdep reports
> in 3.1 I've seen (except for the mmap_sem/i_mutex one) are false
> positives....
While the lockdep report is false positive, I agree that your
change is the right fix to make - the IO completions are already
queued on the workqueue, so they don't need to be flushed to get
them to complete. All that needs to be done is call
ext4_ioend_wait() for them to complete, and that gets rid of the
i_mutex altogether. (*)
Sorry for the noise, Ted.
Cheers,
Dave.
(*) Even better would be to get rid of that flush list altogether
and just use ext4_ioend_wait() everywhere....
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2011-08-26 8:44 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-26 3:33 [URGENT PATCH] ext4: fix potential deadlock in ext4_evict_inode() Theodore Ts'o
2011-08-26 3:56 ` Tao Ma
2011-08-26 9:28 ` Tao Ma
2011-08-26 7:35 ` Dave Chinner
2011-08-26 7:42 ` Tao Ma
2011-08-26 8:44 ` Dave Chinner [this message]
2011-08-26 8:50 ` Christoph Hellwig
2011-08-26 9:10 ` Tao Ma
2011-08-26 9:17 ` Christoph Hellwig
2011-08-26 11:35 ` Theodore Tso
2011-08-26 14:53 ` Tao Ma
2011-08-26 9:03 ` Tao Ma
2011-08-26 9:24 ` Dave Chinner
2011-08-26 9:27 ` Tao Ma
2011-08-26 15:52 ` Ted Ts'o
2011-08-26 16:58 ` Jiaying Zhang
2011-08-26 20:22 ` Ted Ts'o
2011-08-27 5:17 ` Jiaying Zhang
2011-08-31 1:15 ` Jiaying Zhang
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=20110826084403.GA3162@dastard \
--to=david@fromorbit.com \
--cc=jiayingz@google.com \
--cc=linux-ext4@vger.kernel.org \
--cc=tytso@mit.edu \
/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 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.