Re: spurious sillyrename after O_DIRECT writes get ENOSPC

["J. Bruce Fields" <bfields@fieldses.org>]

On Thu, Dec 14, 2017 at 01:55:14PM -0500, J. Bruce Fields wrote:
> So actually what happens is if you do a direct io write where some
> WRITEs succeed and the one fails, then this:
> 
> 	if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
> 		dreq->flags = 0;
> 		dreq->error = hdr->error;
> 	}
> 
> clears the NFS_ODIRECT_DO_COMMIT flag, so nfs_direct_write_complete
> never scheduels the commit calls.  It looks like that leaves a bunch of
> nfs_pages on some to-be-committed list, so we end up leaking a bunch of
> stuff, with the most visible symptom being an unnecessarily sillyrename
> on close.
> 
> I can just remove that clear of dreq_flags and that fixes the problem,
> but I doubt that's correct.

Or, maybe it is.  If *any* WRITE(s) involved in this write might need
a commit or reschedule, then surely we should run
nfs_direct_write_schedule_work and let it sort them out?  I'm having
trouble seeing why clearing that field partway through could ever be
correct.

Trond, Anna, does the following look right?

--b.