From: Zach Brown <zach.brown@oracle.com>
To: Nick Piggin <npiggin@suse.de>
Cc: linux-fsdevel@vger.kernel.org,
Linux Memory Management List <linux-mm@kvack.org>,
Mark Fasheh <mfasheh@suse.com>, Sage Weil <sage@newdream.net>
Subject: Re: [patch][rfc] mm: hold page lock over page_mkwrite
Date: Wed, 25 Feb 2009 08:42:50 -0800 [thread overview]
Message-ID: <49A5750A.1080006@oracle.com> (raw)
In-Reply-To: <20090225093629.GD22785@wotan.suse.de>
Nick Piggin wrote:
> I want to have the page be protected by page lock between page_mkwrite
> notification to the filesystem, and the actual setting of the page
> dirty. Do this by holding the page lock over page_mkwrite, and keep it
> held until after set_page_dirty.
I fear that this will end up creating lock inversions with file systems
who grab cross-node locks, which are ordered outside of the page lock,
inside their ->page_mkwrite(). See ocfs2's call of ocfs2_inode_lock()
from ocfs2_page_mkwrite().
In a sense, it's prepare_write() all over again. Please don't call into
file systems after having acquired the page lock.
Instead, can we get a helper that the file system would call after
having acquired its locks and the page lock? Something like that.
- z
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next prev parent reply other threads:[~2009-02-25 16:42 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-25 9:36 [patch][rfc] mm: hold page lock over page_mkwrite Nick Piggin
2009-02-25 16:42 ` Zach Brown [this message]
2009-02-25 16:55 ` Nick Piggin
2009-02-25 16:58 ` Zach Brown
2009-02-25 17:02 ` Nick Piggin
2009-02-25 22:35 ` Mark Fasheh
2009-02-25 16:48 ` Chris Mason
2009-02-26 9:20 ` Peter Zijlstra
2009-02-26 11:09 ` Nick Piggin
2009-03-01 8:17 ` Dave Chinner
2009-03-01 13:50 ` Nick Piggin
2009-03-02 8:19 ` Dave Chinner
2009-03-02 8:37 ` Nick Piggin
2009-03-02 15:26 ` jim owens
2009-03-03 4:33 ` Nick Piggin
2009-03-03 17:25 ` Jamie Lokier
2009-03-04 4:37 ` Dave Chinner
2009-03-04 9:23 ` Nick Piggin
2009-03-04 18:13 ` Jamie Lokier
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