Messages in this thread | | | From | Daniel Phillips <> | Subject | Re: introduce dm-snap-mv | Date | Fri, 8 Oct 2010 06:22:57 -0700 |
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On Friday 08 October 2010, Christoph Hellwig wrote: > 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.
And that will automatically give him the PAGE_CACHE_SIZE objects he wants. I still don't understand why his model cannot be generalized to arbitrary block size specifiable at create time.
Regards,
Daniel
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