From: Nick Piggin <nickpiggin@yahoo.com.au>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] Preserve the dirty bit in init_page_buffers
Date: Mon, 28 May 2007 14:59:03 +1000 [thread overview]
Message-ID: <465A6197.5010402@yahoo.com.au> (raw)
In-Reply-To: <465A6078.6010804@yahoo.com.au>
Nick Piggin wrote:
> Eric W. Biederman wrote:
>> When we initialize the ramdisk by writing to /dev/ram0 usually in
>> init/do_mounts_rd.c we don't allocate buffer heads but we do set
>> the dirty bit, and the page is in the page cache. So when we
>> later call getblk it reuses the same page and then calls
>> init_page_buffers.
>
>
> Hmm, so this would be a problem for block_dev.c as well, then?
> Because it would be possible to have a dirty block dev page
> have its buffers reclaimed and then reinitialised via
> init_page_buffers, AFAIKS.
Oh, no, try_to_free_buffers won't drop dirty buffers. However we
could still set_page_dirty of a block device page without buffers
via an mmap.
--
SUSE Labs, Novell Inc.
next prev parent reply other threads:[~2007-05-28 4:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-22 2:31 [PATCH 1/3] Preserve the dirty bit in init_page_buffers Eric W. Biederman
2007-05-22 2:36 ` [PATCH 2/3] rd: Mark ramdisk buffer heads dirty in ramdisk_set_page_dirty Eric W. Biederman
2007-05-22 2:40 ` [PATCH 3/3] rd: Simplify by using the same helper functions in libfs Eric W. Biederman
2007-05-28 4:09 ` [PATCH 1/3] Preserve the dirty bit in init_page_buffers Nick Piggin
2007-05-28 4:30 ` Eric W. Biederman
2007-05-28 4:54 ` Nick Piggin
2007-05-28 4:59 ` Nick Piggin [this message]
2007-05-28 14:05 ` Eric W. Biederman
2007-05-29 5:14 ` Nick Piggin
2007-05-29 5:28 ` Eric W. Biederman
2007-05-31 11:56 ` Eric W. Biederman
2007-05-31 15:55 ` Andrew Morton
2007-05-31 16:40 ` [PATCH] rd: Remove ramdisk_set_page_dirty Eric W. Biederman
2007-05-31 16:43 ` [PATCH] buffer: Kill old incorrect? comment Eric W. Biederman
2007-05-28 13:52 ` [PATCH 1/3] Preserve the dirty bit in init_page_buffers Eric W. Biederman
2007-05-28 6:37 ` Nick Piggin
2007-05-28 13:58 ` Eric W. Biederman
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