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Date: Fri, 19 Aug 2005 20:40:45 +0100
From: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
To: Mika =?iso-8859-1?Q?Penttil=E4?= <mika.penttila@kolumbus.fi>
Cc: Linus Torvalds <torvalds@osdl.org>, Anton Altaparmakov <aia21@cam.ac.uk>,
       vandrove@vc.cvut.cz, Andrew Morton <akpm@osdl.org>, linware@sh.cvut.cz,
       fsdevel <linux-fsdevel@vger.kernel.org>,
       lkml <linux-kernel@vger.kernel.org>
Subject: Re: Kernel bug: Bad page state: related to generic symlink code and mmap
Message-ID: <20050819194045.GG29811@parcelfarce.linux.theplanet.co.uk>
References: <1124450088.2294.31.camel@imp.csi.cam.ac.uk> <20050819142025.GA29811@parcelfarce.linux.theplanet.co.uk> <1124466246.2294.65.camel@imp.csi.cam.ac.uk> <Pine.LNX.4.58.0508190855350.3412@g5.osdl.org> <Pine.LNX.4.58.0508190913570.3412@g5.osdl.org> <Pine.LNX.4.58.0508190934470.3412@g5.osdl.org> <20050819165332.GD29811@parcelfarce.linux.theplanet.co.uk> <20050819180218.GE29811@parcelfarce.linux.theplanet.co.uk> <4306301F.9060707@kolumbus.fi>
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On Fri, Aug 19, 2005 at 10:16:47PM +0300, Mika Penttilä wrote:
> Just out of curiosity - what protects even local filesystems against 
> concurrent truncate and symlink resolving when using the page cache helpers?

How do you get truncate(2) or ftruncate(2) to do something with a symlink?
The former follows links, the latter takes an open file...