Re: [PATCH 0/3] nfs: fix -ENOSPC DIO write regression

[Trond Myklebust <trondmy@hammerspace.com>]

On Fri, 2022-07-22 at 14:12 -0400, Jeff Layton wrote:
> Boyang reported that xfstest generic/476 would never complete when
> run
> against a filesystem that was "too small".
> 
> What I found was that we would end up trying to issue a large DIO
> write
> that would come back short. The kernel would then follow up and try
> to
> write out the rest and get back -ENOSPC. It would then try to issue a
> commit, which would then try to reissue the writes, and around it
> would
> go.
> 
> This patchset seems to fix it. Unfortunately, I'm not positive which
> patch _broke_ this as it seems to have happened quite some time ago.
> 
> Jeff Layton (3):
>   nfs: add new nfs_direct_req tracepoint events
>   nfs: always check dreq->error after a commit
>   nfs: only issue commit in DIO codepath if we have uncommitted data
> 
>  fs/nfs/direct.c         | 50 +++++++++--------------------
>  fs/nfs/internal.h       | 33 ++++++++++++++++++++
>  fs/nfs/nfstrace.h       | 69
> +++++++++++++++++++++++++++++++++++++++++
>  fs/nfs/write.c          | 48 +++++++++++++++++-----------
>  include/linux/nfs_xdr.h |  1 +
>  5 files changed, 148 insertions(+), 53 deletions(-)
> 

With this series applied, I'm seeing things like xfstests generic/013
looping forever.

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com