lockd: fix nlmsvc_notify_blocked locking

J. Bruce Fields · arndb · commit a282a1fa6b23 · 2010-10-27T21:39:50.000+02:00
nlmsvc_notify_blocked walks the nlm_blocked list,
which requires nlm_blocked_lock.

Signed-off-by: J. Bruce Fields &lt;bfields@redhat.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
@@ -700,14 +700,16 @@ nlmsvc_notify_blocked(struct file_lock *fl)
 	struct nlm_block	*block;
 
 	dprintk("lockd: VFS unblock notification for block %p\n", fl);
+	spin_lock(&nlm_blocked_lock);
 	list_for_each_entry(block, &nlm_blocked, b_list) {
 		if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
-			nlmsvc_insert_block(block, 0);
+			nlmsvc_insert_block_locked(block, 0);
+			spin_unlock(&nlm_blocked_lock);
 			svc_wake_up(block->b_daemon);
 			return;
 		}
 	}
-
+	spin_unlock(&nlm_blocked_lock);
 	printk(KERN_WARNING "lockd: notification for unknown block!\n");
 }
 

Original file line number	Diff line number	Diff line change
`@@ -700,14 +700,16 @@ nlmsvc_notify_blocked(struct file_lock *fl)`
`700`	`700`	`struct nlm_block *block;`
`701`	`701`
`702`	`702`	`dprintk("lockd: VFS unblock notification for block %p\n", fl);`
	`703`	`+ spin_lock(&nlm_blocked_lock);`
`703`	`704`	`list_for_each_entry(block, &nlm_blocked, b_list) {`
`704`	`705`	`if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {`
`705`		`- nlmsvc_insert_block(block, 0);`
	`706`	`+ nlmsvc_insert_block_locked(block, 0);`
	`707`	`+ spin_unlock(&nlm_blocked_lock);`
`706`	`708`	`svc_wake_up(block->b_daemon);`
`707`	`709`	`return;`
`708`	`710`	`}`
`709`	`711`	`}`
`710`		`-`
	`712`	`+ spin_unlock(&nlm_blocked_lock);`
`711`	`713`	`printk(KERN_WARNING "lockd: notification for unknown block!\n");`
`712`	`714`	`}`
`713`	`715`