All of lore.kernel.org
 help / color / mirror / Atom feed
From: Miklos Szeredi <mszeredi@suse.cz>
To: Amerigo Wang <amwang@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, heiko.carstens@de.ibm.com,
	linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk
Subject: Re: [Patch] pipe: use file_update_time() when hold i_mutex
Date: Tue, 21 Jul 2009 13:09:40 +0200	[thread overview]
Message-ID: <1248174580.28516.595.camel@tucsk> (raw)
In-Reply-To: <4A65934B.9050904@redhat.com>

On Tue, 2009-07-21 at 18:07 +0800, Amerigo Wang wrote:
> Andrew Morton wrote:
> > On Mon, 6 Jul 2009 01:35:30 -0400
> > Amerigo Wang <amwang@redhat.com> wrote:
> >
> >   
> >> file_update_time() should be called with i_mutex held,
> >> move it before mutex_unlock().
> >>
> >>     
> >
> > Why do you believe that file_update_time() needs i_mutex?
> >   
> file_update_time() modifies inode, no? :)

So does touch_atime(), yet neither needs i_mutex.

But calling file_update_time() within the locked region in pipe_write()
might make sense regardless: that way a task waiting for data would be
guaranteed to see the time change after receiving a POLLIN event for
example.

Thanks,
Miklos



  reply	other threads:[~2009-07-21 11:09 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-06  5:35 [Patch] pipe: use file_update_time() when hold i_mutex Amerigo Wang
2009-07-20 21:11 ` Andrew Morton
2009-07-21 10:07   ` Amerigo Wang
2009-07-21 11:09     ` Miklos Szeredi [this message]
2009-07-22  9:21       ` Amerigo Wang
2009-08-03 16:58         ` Miklos Szeredi

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=1248174580.28516.595.camel@tucsk \
    --to=mszeredi@suse.cz \
    --cc=akpm@linux-foundation.org \
    --cc=amwang@redhat.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    /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.