commit e6df3a663a5d1ee68aeae7f007197f272700d9cc
author Joel Becker <joel.becker@oracle.com> Tue Feb 06 15:45:39 2007 -0800
committer Mark Fasheh <mark.fasheh@oracle.com> Tue Jul 10 17:19:46 2007 -0700
tree e484382e0ae46553febd3dd56c0f8a9e882ec71b
parent 16c6a4f24de2933b26477ad5dfb71f518220d641

ocfs2: Wake up a starting region if it gets killed in the background.

Tell o2cb_region_dev_write() to wake up if rmdir(2) happens on the
heartbeat region while it is starting up.  Then o2hb_region_dev_write()
can check to see if it is alive and act accordingly.  This prevents a hang
(not being woken) and a crash (if it's woken by a signal).

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/cluster/heartbeat.c

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 2877d46..2bd7f78 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -1335,6 +1335,7 @@
 	ret = wait_event_interruptible(o2hb_steady_queue,
 				atomic_read(&reg->hr_steady_iterations) == 0);
 	if (ret) {
+		/* We got interrupted (hello ptrace!).  Clean up */
 		spin_lock(&o2hb_live_lock);
 		hb_task = reg->hr_task;
 		reg->hr_task = NULL;
@@ -1345,7 +1346,16 @@
 		goto out;
 	}
 
-	ret = count;
+	/* Ok, we were woken.  Make sure it wasn't by drop_item() */
+	spin_lock(&o2hb_live_lock);
+	hb_task = reg->hr_task;
+	spin_unlock(&o2hb_live_lock);
+
+	if (hb_task)
+		ret = count;
+	else
+		ret = -EIO;
+
 out:
 	if (filp)
 		fput(filp);
@@ -1523,6 +1533,15 @@
 	if (hb_task)
 		kthread_stop(hb_task);
 
+	/*
+	 * If we're racing a dev_write(), we need to wake them.  They will
+	 * check reg->hr_task
+	 */
+	if (atomic_read(&reg->hr_steady_iterations) != 0) {
+		atomic_set(&reg->hr_steady_iterations, 0);
+		wake_up(&o2hb_steady_queue);
+	}
+
 	config_item_put(item);
 }