Re: [RFC] block integrity: Fix write after checksum calculationproblem

[Joel Becker]

On Wed, Feb 23, 2011 at 03:35:11PM -0500, Chris Mason wrote:
> >     ocfs2 handles stable metadata for its checksums when feeding
> > things to the journal.  If we're doing pagecache-based I/O, is the
> > pagecache going to help here for data?
> 
> Data is much easier than metadata.  All you really need is to wait on
> writeback in file_write, wait on writeback in page_mkwrite, and make
> sure you don't free blocks back to the allocator that are actively under
> IO.
> 
> I expect the hard part to be jbd and metadata in ext34.

	Yeah, catching use-without-access is not trivial.  I keep
thinking we've found them all, and then another bug crops up ;-)  At
least our checksums catch it.

Joel

-- 

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 man really clever who has not found that he is stupid."
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			jlbec@xxxxxxxxxxxx
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