[PATCH 3/3] xfs: cancel COW in xfs_cancel_ioend

[Darrick J. Wong]

On Thu, Jan 07, 2016 at 04:25:42PM +0100, Christoph Hellwig wrote:
> On Wed, Jan 06, 2016 at 04:32:27PM -0800, Darrick J. Wong wrote:
> > Ok.  I spent a couple of days trying to find all the places where we need to
> > delete CoW reservations (hole punch, truncate, etc.) and found some places
> > where the code was leaving reservations behind in the CoW fork (most notable
> > truncate).  I also made the inode eviction code purge any CoW leftovers, so
> > that should all go away.
> 
> Can you send that part out for NFS testing?

Ok, I've uploaded the latest kernel + xfstests to github:
https://github.com/djwong/linux/commits/for-dave
https://github.com/djwong/xfstests/tree/for-dave

(Big pile of new tests to try to exercise the cow cancellation code.)

> 
> > I also wrote some more xfstests that try to hit all the CoW-cancelling code
> > paths (fpunch, fzero, fcollapse, finsert, truncate, -EIO) to smoke test all
> > that.  By the way, do you have a testcase handy for the "non-blocking writeback
> > EAGAIN" case?  I'm guessing that we could hit that pretty easily by lowering
> > dirty_background_* and dirtying a lot of pages while reflinking?
> 
> I did hit it pretty easily testing over NFS to a local nfs server with
> xfstests.

Hmm.  If my latest round of fixes didn't get this one, I'll see next week if
I can get the NFS stuff working so I can test it directly.

--D

> 
> _______________________________________________
> xfs mailing list
> xfs at oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs