NFSv4: Do not accept delegated opens when a delegation recall
is in effect (bnc#864409).

suse-commit: 36bde8609e685a4967374c0ceb33c555adfa0c8f
NFSv4.1: Fix a race in the pNFS return-on-close code
(bnc#864409).

suse-commit: 8ba216aaa013c999d4be18f53acf587090d247da
NFSv4.1: Fix an ABBA locking issue with session and state
serialisation (bnc#864409).

suse-commit: 1f3fe9ef734d40f4431e16db90e6adaeec9a27fc
pnfs: defer release of pages in layoutget (bnc#864411).

suse-commit: 15d4d8f691db6ab894c4a54bb37eefd361c6b052
NFSv4.1: Don't decode skipped layoutgets (bnc#864411).

suse-commit: 358a8b0bd119018a86a301e1fef83d6014315848