[Ocfs2-commits] smushran commits r2992 - branches/ocfs2-1.2/fs/ocfs2/dlm

[svn-commits at oss.oracle.com]

Author: smushran
Date: 2007-03-22 14:11:20 -0700 (Thu, 22 Mar 2007)
New Revision: 2992

Modified:
   branches/ocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c
   branches/ocfs2-1.2/fs/ocfs2/dlm/dlmthread.c
Log:
ocfs2_dlm: Fixes lockres ref counting bug

During umount, the umount thread migrates the lockres' and the dlm_thread
frees the empty lockres'. Due to a race, the reference counting on the
lockres goes awry leading to extra puts.

Signed-off-by: mfasheh

Modified: branches/ocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c
===================================================================
--- branches/ocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c	2007-03-16 16:40:23 UTC (rev 2991)
+++ branches/ocfs2-1.2/fs/ocfs2/dlm/dlmdomain.c	2007-03-22 21:11:20 UTC (rev 2992)
@@ -111,8 +111,10 @@
 
 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
 {
-	hlist_del_init(&lockres->hash_node);
-	dlm_lockres_put(lockres);
+	if (!hlist_unhashed(&lockres->hash_node)) {
+		hlist_del_init(&lockres->hash_node);
+		dlm_lockres_put(lockres);
+	}
 }
 
 void __dlm_insert_lockres(struct dlm_ctxt *dlm,

Modified: branches/ocfs2-1.2/fs/ocfs2/dlm/dlmthread.c
===================================================================
--- branches/ocfs2-1.2/fs/ocfs2/dlm/dlmthread.c	2007-03-16 16:40:23 UTC (rev 2991)
+++ branches/ocfs2-1.2/fs/ocfs2/dlm/dlmthread.c	2007-03-22 21:11:20 UTC (rev 2992)
@@ -257,20 +257,14 @@
 			break;
 		}
 
-		mlog(0, "removing lockres %.*s:%p from purgelist\n",
-		     lockres->lockname.len, lockres->lockname.name, lockres);
-		list_del_init(&lockres->purge);
-		dlm_lockres_put(lockres);
-		dlm->purge_count--;
+		dlm_lockres_get(lockres);
 
 		/* This may drop and reacquire the dlm spinlock if it
 		 * has to do migration. */
-		mlog(0, "calling dlm_purge_lockres!\n");
-		dlm_lockres_get(lockres);
 		if (dlm_purge_lockres(dlm, lockres))
 			BUG();
+
 		dlm_lockres_put(lockres);
-		mlog(0, "DONE calling dlm_purge_lockres!\n");
 
 		/* Avoid adding any scheduling latencies */
 		cond_resched_lock(&dlm->spinlock);