DAFS: VnLock after VnWaitQuiescent in VAllocVnode
authorAndrew Deason <adeason@sinenomine.net>
Fri, 25 Feb 2011 22:01:32 +0000 (16:01 -0600)
committerDerrick Brashear <shadow@dementia.org>
Fri, 4 Mar 2011 15:37:32 +0000 (07:37 -0800)
In VAllocVnode, we write-lock the newly-allocated vnode. In DAFS,
however, we need to VnWaitQuiescent_r before VnLock'ing, since VnLock
in DAFS just sets the writer tid/pid. So, in VAllocVnode, move the
VnLock call to after we wait for quiescence, so we don't stomp over
the vnode when someone else has it write-locked.

Change-Id: Ib234634dba9d09eea877bc91660ea3a8a4e2b746
Reviewed-on: http://gerrit.openafs.org/4059
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>

src/vol/vnode.c

index 3c10baa..532fe83 100644 (file)
@@ -669,9 +669,6 @@ VAllocVnode_r(Error * ec, Volume * vp, VnodeType type)
            /* This won't block */
            VnLock(vnp, WRITE_LOCK, VOL_LOCK_HELD, WILL_NOT_DEADLOCK);
        } else {
-           /* other users present; follow locking hierarchy */
-           VnLock(vnp, WRITE_LOCK, VOL_LOCK_HELD, MIGHT_DEADLOCK);
-
 #ifdef AFS_DEMAND_ATTACH_FS
            /*
             * DAFS:
@@ -689,6 +686,9 @@ VAllocVnode_r(Error * ec, Volume * vp, VnodeType type)
            }
 #endif
 
+           /* other users present; follow locking hierarchy */
+           VnLock(vnp, WRITE_LOCK, VOL_LOCK_HELD, MIGHT_DEADLOCK);
+
            /*
             * verify state of the world hasn't changed
             *