Cache deferral improvements - try N+2

I don't think it is quite 6 months since I last posted these, but I've definitely dropped the ball... so here they are again.

This set allows kernel threads to wait a short while for an upcall (to get auth info) to complete rather than having to queue and retry the whole request.
It also changes NFSv4 to never use the old deferral scheme at all.

The last two patches are just little clean-ups that I found while wandering around the code.

I think I have address all the concern raised previously, e.g.
http://www.spinics.net/lists/linux-nfs/msg12253.html

Note that there is a conflict between this patch set and the other one. The other changes someing in nfs4idmap.c, and this one removes all the code that was changed. Very easy to resolve.

Thanks,
NeilBrown

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NeilBrown (6):
sunrpc/cache: allow threads to block while waiting for cache update. nfsd/idmap: drop special request deferal in favour of improved default.
sunrpc: close connection when a request is irretrievably lost.
nfsd: disable deferral for NFSv4
svcauth_gss: replace a trivial 'switch' with an 'if' sunrpc/cache: change deferred-request hash table to use hlist.

 fs/nfsd/nfs4idmap.c               |  105 ++++---------------------------------
 fs/nfsd/nfs4proc.c                |    4 +
 include/linux/sunrpc/cache.h      |    5 +-
 include/linux/sunrpc/svcauth.h    |   10 ++--
 net/sunrpc/auth_gss/svcauth_gss.c |   51 ++++++++----------
 net/sunrpc/cache.c                |   71 +++++++++++++++++++------
 net/sunrpc/svc.c                  |    3 +
 net/sunrpc/svc_xprt.c             |   11 ++++
 net/sunrpc/svcauth_unix.c         |   11 +++-
 9 files changed, 125 insertions(+), 146 deletions(-)

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