tree 391b3b25eb0ac4780c5498f76fef1927f59fe907
parent 07d9a380680d1c0eb51ef87ff2eab5c994949e69
author Jeff Layton <jlayton@redhat.com> 1476970471 -0400
committer J. Bruce Fields <bfields@redhat.com> 1477342281 -0400

nfsd: move blocked lock handling under a dedicated spinlock

Bruce was hitting some lockdep warnings in testing, showing that we
could hit a deadlock with the new CB_NOTIFY_LOCK handling, involving a
rather complex situation involving four different spinlocks.

The crux of the matter is that we end up taking the nn->client_lock in
the lm_notify handler. The simplest fix is to just declare a new
per-nfsd_net spinlock to protect the new CB_NOTIFY_LOCK structures.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>