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From: Christoph Hellwig <hch@lst.de>
To: McPacino <mcpacino@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>,
	Daniel Phillips <phillips@phunq.net>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	dm-devel@redhat.com, Andrew Morton <akpm@linux-foundation.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Nick Piggin <npiggin@kernel.dk>
Subject: Re: introduce dm-snap-mv
Date: Fri, 8 Oct 2010 11:24:27 +0200	[thread overview]
Message-ID: <20101008092427.GA5426@lst.de> (raw)
In-Reply-To: <AANLkTim9KFuP1_mrUUsMOEspxkfA=SZW2dmTX4WJbfep@mail.gmail.com>

On Fri, Oct 08, 2010 at 05:14:27PM +0800, McPacino wrote:
> Hi Christoph,
> 
> I have to take care the cache problem If using the bio directly.
> BHs can be released by kernel when necessary.
> 
> Is there any existing code using bio to read/write metadata
> blocks? How do they handle the timing freeing bios? I really
> wish to learn something form it.

If you actually need caching just use the pagecache, e.g.
read_mapping_page to read in your data.  That completely abstracts
away the underlying block size.

  reply	other threads:[~2010-10-08  9:24 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-06  8:31 introduce dm-snap-mv Cong Meng
2010-10-06  8:31 ` Cong Meng
2010-10-06  8:31 ` Cong Meng
2010-10-07 21:31 ` Daniel Phillips
2010-10-07 21:31   ` Daniel Phillips
2010-10-08  8:22   ` Christoph Hellwig
2010-10-08  9:14     ` McPacino
2010-10-08  9:24       ` Christoph Hellwig [this message]
2010-10-08  9:28         ` McPacino
2010-10-08 13:22         ` Daniel Phillips
2010-10-13 16:45         ` McPacino
2010-10-13 16:45           ` McPacino
2010-10-08  9:01   ` McPacino
2010-10-19 19:58 ` [dm-devel] " Mikulas Patocka
2010-11-06  3:24   ` Daniel Phillips

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