tree 5a2a62efa453f8c85299063cc83a1bd819f0778a
parent 9a99af494bd7141d567d00b5ef94b141821e158c
author Trond Myklebust <Trond.Myklebust@netapp.com> 1360082608 -0500
committer Trond Myklebust <Trond.Myklebust@netapp.com> 1360614792 -0500

NFSv4.1: Don't lose locks when a server reboots during delegation return

If the server reboots while we are converting a delegation into
OPEN/LOCK stateids as part of a delegation return, the current code
will simply exit with an error. This causes us to lose both
delegation state and locking state (i.e. locking atomicity).

Deal with this by exposing the delegation stateid during delegation
return, so that we can recover the delegation, and then resume
open/lock recovery.

Note that not having to hold the nfs_inode->rwsem across the
calls to nfs_delegation_claim_opens() also fixes a deadlock against
the NFSv4.1 reboot recovery code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>