From: Nick Piggin <nickpiggin@yahoo.com.au>
To: David Howells <dhowells@redhat.com>
Cc: akpm@osdl.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 3/3] AFS: Implement basic file write support
Date: Fri, 11 May 2007 16:14:39 +1000 [thread overview]
Message-ID: <464409CF.4090203@yahoo.com.au> (raw)
In-Reply-To: <27482.1178790992@warthog.cambridge.redhat.com>
David Howells wrote:
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
>
>>Why do you call SetPageUptodate when the page is not up to date?
>>That leaks uninitialised data, AFAIKS.
>
>
> It only seems that way. If afs_prepare_write() is called, but doesn't return
> an error, then afs_commit_write() will be called, and it seems that the copy
> in of the data will be guaranteed not to fail by the caller.
Not only does it seem that way, it is that way :) PG_uptodate is being set
when the page is not uptodate, isn't it?
> Furthermore, afs_prepare_page() will have filled in the missing bits.
>
> And whilst all that is going on, the page lock will be help by the caller, so
> that no-one else can access the partially complete page.
When a page is uptodate in pagecache, the generic read and nopage functions
do not take the page lock. So how are you excluding those?
--
SUSE Labs, Novell Inc.
prev parent reply other threads:[~2007-05-11 6:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-08 19:43 [PATCH 1/3] AFS: Export a couple of core functions for AFS write support David Howells
2007-05-08 19:44 ` [PATCH 2/3] AFS: AFS fixups David Howells
2007-05-08 19:44 ` [PATCH 3/3] AFS: Implement basic file write support David Howells
2007-05-09 0:00 ` Andrew Morton
2007-05-09 10:25 ` David Howells
2007-05-09 10:41 ` Andrew Morton
2007-05-09 11:07 ` David Howells
2007-05-09 16:28 ` Andrew Morton
2007-05-09 23:42 ` Nick Piggin
2007-05-10 9:56 ` David Howells
2007-05-11 6:14 ` Nick Piggin [this message]
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