LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Anton Altaparmakov <aia21@cam.ac.uk>
To: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
	Hugh Dickins <hugh@veritas.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Linux Memory Management <linux-mm@kvack.org>,
	David Howells <dhowells@redhat.com>,
	Andrew Morton <akpm@osdl.org>
Subject: Re: page_mkwrite caller is racy?
Date: Tue, 30 Jan 2007 14:58:50 +0000 (GMT)	[thread overview]
Message-ID: <Pine.LNX.4.64.0701301456250.6541@hermes-1.csi.cam.ac.uk> (raw)
In-Reply-To: <20070130015159.GA14799@ca-server1.us.oracle.com>

On Mon, 29 Jan 2007, Mark Fasheh wrote:
> On Tue, Jan 30, 2007 at 12:14:24PM +1100, Nick Piggin wrote:
> > This is another discussion, but do we want the page locked here? Or
> > are the filesystems happy to exclude truncate themselves?
> 
> No page lock please. Generally, Ocfs2 wants to order cluster locks outside
> of page locks. Also, the sparse b-tree support I'm working on right now will
> need to be able to allocate in ->page_mkwrite() which would become very
> nasty if we came in with the page lock - aside from the additional cluster
> locks taken, ocfs2 will want to zero some adjacent pages (because we support
> atomic allocation up to 1 meg).

Ditto for NTFS.  I will need to lock pages on both sides of the page for 
large volume cluster sizes thus I will have to drop the page lock if it is 
already taken so it might as well not be...  Although I do not feel 
strongly about it.  If the page is locked I will just drop the lock and 
then take it again.  If possible to not have the page locked that would 
make my code a little easier/more efficient I expect...

Best regards,

	Anton
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer, http://www.linux-ntfs.org/

  reply	other threads:[~2007-01-30 15:00 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-29 10:20 Nick Piggin
2007-01-29 16:08 ` Hugh Dickins
2007-01-29 20:41   ` Anton Altaparmakov
2007-01-30  1:14   ` Nick Piggin
2007-01-30  1:51     ` Mark Fasheh
2007-01-30 14:58       ` Anton Altaparmakov [this message]
2007-01-31  1:18         ` Nick Piggin
2007-01-29 20:00 ` Mark Fasheh
2007-02-01 11:44 ` David Howells

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=Pine.LNX.4.64.0701301456250.6541@hermes-1.csi.cam.ac.uk \
    --to=aia21@cam.ac.uk \
    --cc=akpm@osdl.org \
    --cc=dhowells@redhat.com \
    --cc=hugh@veritas.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mark.fasheh@oracle.com \
    --cc=nickpiggin@yahoo.com.au \
    --subject='Re: page_mkwrite caller is racy?' \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).