Re: [PATCH 0/4] 2.6.21-rc7 NFS writes: fix a series of issues

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Tue, 2007-04-17 at 21:19 -0400, Trond Myklebust wrote:
> I've split the issues introduced by the 2.6.21-rcX write code up into 4
> subproblems.
> 
> The first patch is just a cleanup in order to ease review.
> 
> Patch number 2 ensures that we never release the PG_writeback flag until
> _after_ we've either discarded the unstable request altogether, or put it
> on the nfs_inode's commit or dirty lists.
> 
> Patch number 3 fixes the 'desynchronized value of nfs_i.ncommit' error. It
> uses the PG_NEED_COMMIT flag as an indicator for whether or not the request
> may be redirtied.
> 
> Patch number 4 protects the NFS '.set_page_dirty' address_space operation
> against races with nfs_inode_add_request.

Ok, stuck them in, and my debug patch from yesterday, just in case...

However, I can't seem to run long enough to establish whether the
problem is gone. It deadlocks between 10-30 minutes due to missing IO
completions, whereas yesterday it took between 45-60 minutes to trigger
the 'desynchronized value of nfs_i.ncommit' messages.

I will continue trying go get a good run, however if you got some
(perhaps experimental .22) patches you want me to try..