ocfs2: fix race between mount and delete node/cluster (0986fe9b) · Commits · 戴 / test

There is a race case between mount and delete node/cluster, which will lead o2hb_thread to malfunctioning dead loop. o2hb_thread { o2nm_depend_this_node(); <<<<<< race window, node may have already been deleted, and then enter the loop, o2hb thread will be malfunctioning because of no configured nodes found. while (!kthread_should_stop() && !reg->hr_unclean_stop && !reg->hr_aborted_start) { } So check the return value of o2nm_depend_this_node() is needed. If node has been deleted, do not enter the loop and let mount fail. Signed-off-by:

Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/cluster/heartbeat.c

+16 −3

Original line number	Diff line number	Diff line
		@@ -219,7 +219,8 @@ struct o2hb_region {
		unsigned hr_unclean_stop:1,
		hr_aborted_start:1,
		hr_item_pinned:1,
		hr_item_dropped:1;
		hr_item_dropped:1,
		hr_node_deleted:1;

		/* protected by the hr_callback_sem */
		struct task_struct *hr_task;
		@@ -1078,7 +1079,13 @@ static int o2hb_thread(void *data)
		set_user_nice(current, MIN_NICE);

		/* Pin node */
		o2nm_depend_this_node();
		ret = o2nm_depend_this_node();
		if (ret) {
		mlog(ML_ERROR, "Node has been deleted, ret = %d\n", ret);
		reg->hr_node_deleted = 1;
		wake_up(&o2hb_steady_queue);
		return 0;
		}

		while (!kthread_should_stop() &&
		!reg->hr_unclean_stop && !reg->hr_aborted_start) {
		@@ -1787,7 +1794,8 @@ static ssize_t o2hb_region_dev_write(struct o2hb_region *reg,
		spin_unlock(&o2hb_live_lock);

		ret = wait_event_interruptible(o2hb_steady_queue,
		atomic_read(&reg->hr_steady_iterations) == 0);
		atomic_read(&reg->hr_steady_iterations) == 0 \|\|
		reg->hr_node_deleted);
		if (ret) {
		atomic_set(&reg->hr_steady_iterations, 0);
		reg->hr_aborted_start = 1;
		@@ -1798,6 +1806,11 @@ static ssize_t o2hb_region_dev_write(struct o2hb_region *reg,
		goto out3;
		}

		if (reg->hr_node_deleted) {
		ret = -EINVAL;
		goto out3;
		}

		/* Ok, we were woken. Make sure it wasn't by drop_item() */
		spin_lock(&o2hb_live_lock);
		hb_task = reg->hr_task;

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