features/locks: Fix broken interface grant_blocked_inode_locks

Signed-off-by: Pavan Vilas Sondur <pavan@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 496 (deadlock in pl_inode_setlk)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=496

2 files changed, 35 insertions, 22 deletions

diff --git a/xlators/features/locks/src/common.h b/xlators/features/locks/src/common.h
index 46da9e78cb1..00532ea6f92 100644
--- a/xlators/features/locks/src/common.h
+++ b/xlators/features/locks/src/common.h
@@ -54,7 +54,7 @@ pl_dom_list_t *
 get_domain (pl_inode_t *pl_inode, const char *volume);
 
 void
-grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_inode_lock_t *lock, pl_dom_list_t *dom);
+grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom);
 
 void
 __delete_inode_lock (pl_inode_lock_t *lock);
diff --git a/xlators/features/locks/src/inodelk.c b/xlators/features/locks/src/inodelk.c
index 9e9d6d17389..50a5996d74a 100644
--- a/xlators/features/locks/src/inodelk.c
+++ b/xlators/features/locks/src/inodelk.c
@@ -304,7 +304,8 @@ out:
 
 }
 static void
-__grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom)
+__grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, 
+			     struct list_head *granted, pl_dom_list_t *dom)
 {
 	int	      bl_ret = 0;
 	pl_inode_lock_t *bl = NULL;
@@ -322,19 +323,7 @@ __grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t
 		bl_ret = __lock_inodelk (this, pl_inode, bl, 1, dom);
 
 		if (bl_ret == 0) {
-                        gf_log (this->name, GF_LOG_TRACE,
-                                "%s (pid=%d) (lk-owner=%"PRIu64") %"PRId64" - %"PRId64" => Granted",
-                                bl->fl_type == F_UNLCK ? "Unlock" : "Lock",
-                                bl->client_pid,
-                                bl->owner,
-                                bl->user_flock.l_start,
-                                bl->user_flock.l_len);
-
-                        pl_trace_out (this, bl->frame, NULL, NULL, F_SETLKW,
-                                      &bl->user_flock, 0, 0, bl->volume);
-
-
-                        STACK_UNWIND_STRICT (inodelk, bl->frame, 0, 0);
+			list_add (&bl->blocked_locks, granted);
                 }
         }
 	return;
@@ -342,18 +331,39 @@ __grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t
 
 /* Grant all inodelks blocked on a lock */
 void
-grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_inode_lock_t *lock, pl_dom_list_t *dom)
+grant_blocked_inode_locks (xlator_t *this, pl_inode_t *pl_inode, pl_dom_list_t *dom)
 {
+	struct list_head granted;
+	pl_inode_lock_t *lock;
+	pl_inode_lock_t *tmp;
+
+	INIT_LIST_HEAD (&granted);
 
         if (list_empty (&dom->blocked_inodelks)) {
                 gf_log (this->name, GF_LOG_TRACE,
                         "No blocked locks to be granted for domain: %s", dom->domain);
-                goto out;
         }
 
-	__grant_blocked_inode_locks (this, pl_inode, dom);
-out:
-        __destroy_inode_lock (lock);
+        pthread_mutex_lock (&pl_inode->mutex);
+	{
+		__grant_blocked_inode_locks (this, pl_inode, &granted, dom);
+	}
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+	list_for_each_entry_safe (lock, tmp, &granted, blocked_locks) {
+                gf_log (this->name, GF_LOG_TRACE,
+			"%s (pid=%d) (lk-owner=%"PRIu64") %"PRId64" - %"PRId64" => Granted",
+			lock->fl_type == F_UNLCK ? "Unlock" : "Lock",
+			lock->client_pid,
+			lock->owner,
+			lock->user_flock.l_start,
+			lock->user_flock.l_len);
+
+		pl_trace_out (this, lock->frame, NULL, NULL, F_SETLKW,
+			      &lock->user_flock, 0, 0, lock->volume);
+
+		STACK_UNWIND_STRICT (inodelk, lock->frame, 0, 0);
+	}
 
 }
 
@@ -408,8 +418,8 @@ release_inode_locks_of_transport (xlator_t *this, pl_dom_list_t *dom,
                                 continue;
 
                         __delete_inode_lock (l);
+			__destroy_inode_lock (l);
 
-			grant_blocked_inode_locks (this, pinode, l, dom);
 
                         if (inode_path (inode, NULL, &path) < 0) {
                                 gf_log (this->name, GF_LOG_TRACE,
@@ -440,6 +450,7 @@ unlock:
                 FREE (l);
         }
 
+	grant_blocked_inode_locks (this, pinode, dom);
 	return 0;
 }
 
@@ -484,13 +495,15 @@ pl_inode_setlk (xlator_t *this, pl_inode_t *pl_inode, pl_inode_lock_t *lock,
                         ret = -EINVAL;
                         goto out;
                 }
+		__destroy_inode_lock (retlock);
 
                 ret = 0;
 
-                grant_blocked_inode_locks (this, pl_inode, retlock, dom);
+
 	}
 out:
 	pthread_mutex_unlock (&pl_inode->mutex);
+	grant_blocked_inode_locks (this, pl_inode, dom);
         return ret;
 }