[Ocfs2-commits] zab commits r1763 - trunk/cluster

[svn-commits at oss.oracle.com]

Author: zab
Date: 2005-01-12 19:01:12 -0600 (Wed, 12 Jan 2005)
New Revision: 1763

Modified:
   trunk/cluster/dlmmod.c
Log:
o fix double-unlocks and lock-free list_for_each in unlock paths.


Modified: trunk/cluster/dlmmod.c
===================================================================
--- trunk/cluster/dlmmod.c	2005-01-13 00:59:40 UTC (rev 1762)
+++ trunk/cluster/dlmmod.c	2005-01-13 01:01:12 UTC (rev 1763)
@@ -675,6 +675,7 @@
 EXPORT_SYMBOL(dlmunlock);
 
 
+/* called holding both res->spinlock and lock->spinlock */
 dlm_status dlmunlock_local(dlm_ctxt *dlm, dlm_lock_resource *res, dlm_lock *lock, dlm_lockstatus *lksb, int flags, int *call_ast)
 {
 	dlm_status status;
@@ -938,14 +939,16 @@
 	status = DLM_IVLOCKID;
 	res = dlm_lookup_lock(dlm, &lockname);
 	if (res) {
-		spin_lock(&res->spinlock);
 		queue = &res->granted;
 again:
+		found = 0;
+		spin_lock(&res->spinlock);
 		list_for_each(iter, queue) {
 			lock = list_entry(iter, dlm_lock, list);
 			if (lock->cookie == unlock->cookie &&
 			    lock->node == unlock->node_idx) {
 				found = 1;
+				spin_lock(&lock->spinlock);
 				lksb = lock->lksb;
 				/* unlockast only called on originating node */
 				if (flags & LKM_PUT_LVB) {
@@ -958,6 +961,8 @@
 				break;
 			}
 		}
+		if (!found)
+			spin_unlock(&res->spinlock);
 		if (queue == &res->granted) {
 			queue = &res->converting;
 			goto again;
@@ -965,7 +970,6 @@
 			queue = &res->blocked;
 			goto again;
 		}
-		spin_unlock(&res->spinlock);
 	}
 	if (!found)
 		dlmprintk("failed to find lock to unlock!  cookie=%llu\n", unlock->cookie);
@@ -1785,7 +1789,9 @@
 				break;
 			}
 		}
-		spin_unlock(&res->spinlock);
+		/* dlmconvert_lock released res->spinlock! */
+		if (!found)
+			spin_unlock(&res->spinlock);
 	}
 	if (!found)
 		dlmprintk("failed to find lock to convert on grant queue!  cookie=%llu\n", convert->cookie);