[PATCH] lock_buffer_wq do lock

[Hugh Dickins]

I've twice got fs/buffer.c:2668 submit_bh BUG_ON(!buffer_locked(bh)):
when called from sync_dirty_buffer which clearly does the lock_buffer.
My suspicion falls on lock_buffer_wq (whereas __lock_page_wq looks OK).

I'm leaving a test running,
can't judge until tomorrow whether this is indeed the fix to that.

Hugh

--- 2.5.71-mm1/include/linux/buffer_head.h	Sun Jun 15 12:36:11 2003
+++ linux/include/linux/buffer_head.h	Mon Jun 16 14:13:25 2003
@@ -291,9 +291,11 @@
 
 static inline int lock_buffer_wq(struct buffer_head *bh, wait_queue_t *wait)
 {
-	if (test_set_buffer_locked(bh))
-		return __wait_on_buffer_wq(bh, wait);
-
+	while (test_set_buffer_locked(bh)) {
+		int ret = __wait_on_buffer_wq(bh, wait);
+		if (ret)
+			return ret;
+	}
 	return 0;
 }