From: Jan Blunck <jblunck@suse.de>
To: Oliver Neukum <oliver@neukum.org>
Cc: "Jamie Lokier" <jamie@shareable.org>,
"Alan Cox" <alan@lxorguk.ukuu.org.uk>,
linux-fsdevel@vger.kernel.org,
"Linux-Kernel Mailinglist" <linux-kernel@vger.kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
jkacur@redhat.com, "Thomas Gleixner" <tglx@linutronix.de>,
"Arnd Bergmann" <arnd@arndb.de>,
"Christoph Hellwig" <hch@infradead.org>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"Alexander Viro" <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH 1/2] BKL: Remove BKL from default_llseek()
Date: Wed, 18 Nov 2009 18:55:40 +0100 [thread overview]
Message-ID: <20091118175540.GR21750@bolzano.suse.de> (raw)
In-Reply-To: <200911181835.55007.oliver@neukum.org>
On Wed, Nov 18, Oliver Neukum wrote:
> Am Mittwoch, 18. November 2009 18:27:30 schrieb Jamie Lokier:
> > > No. Your logic is flawed
> > >
> > > The BKL is protected something here - it protects the change of offset
> > > with respect to other BKL users within drivers. The question is what if
> > > anything in any other driver code depends upon the BKL and uses it to
> > > protect f_pos. Probably very little if anything but a grep for f_pos
> > > through the drivers might not be a bad idea before assuming this. Very
> > > few touch f_pos except in their own llseek method.
> >
> > Of course, drivers shouldn't be using f_pos outside their llseek
> > method, as they should all behave the same with pread/pwrite as with
> > llseek+read/write.
>
> Might not a driver update f_pos after read/write?
Actually the VFS is doing that for you in read/write syscall. So anything you
change in your driver gets corrected (or overwritten anyway).
Regards,
Jan
--
Jan Blunck <jblunck@suse.de>
next prev parent reply other threads:[~2009-11-18 17:55 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-18 16:07 Jan Blunck
2009-11-18 16:07 ` [PATCH 2/2] BKL: Update documentation on llseek( \b) Jan Blunck
2009-11-18 17:15 ` [PATCH 1/2] BKL: Remove BKL from default_llseek() Alan Cox
2009-11-18 17:27 ` Jamie Lokier
2009-11-18 17:33 ` Arnd Bergmann
2009-11-18 18:00 ` Alan Cox
2009-11-18 18:06 ` Arnd Bergmann
2009-11-18 18:14 ` Alan Cox
2009-11-18 19:17 ` Arnd Bergmann
2009-11-18 17:35 ` Oliver Neukum
2009-11-18 17:50 ` Jamie Lokier
2009-11-18 18:16 ` Alan Cox
2009-11-19 2:40 ` Jamie Lokier
2009-11-19 10:13 ` Alan Cox
2009-11-18 17:55 ` Alan Cox
2009-11-18 17:55 ` Jan Blunck [this message]
2009-11-18 17:53 ` Jan Blunck
2009-11-18 18:17 ` Alan Cox
2009-11-18 20:02 ` Jan Blunck
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=20091118175540.GR21750@bolzano.suse.de \
--to=jblunck@suse.de \
--cc=akpm@linux-foundation.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=arnd@arndb.de \
--cc=fweisbec@gmail.com \
--cc=hch@infradead.org \
--cc=jamie@shareable.org \
--cc=jkacur@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oliver@neukum.org \
--cc=tglx@linutronix.de \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®