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Commit 6380f26f authored by Mike Anderson's avatar Mike Anderson Committed by Alasdair G Kergon
Browse files

dm mpath: add mutex to synchronize adding and flushing work 



Add a mutex to allow possible creators of new work to synchronize with
flushing work queues.

Signed-off-by: default avatarMike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: default avatarKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent c50abeb3

drivers/md/dm-mpath.c

+38 −21
Original line number Diff line number Diff line
@@ -93,6 +93,8 @@ struct multipath { 
	 * can resubmit bios on error.

	 */

	mempool_t *mpio_pool;



	struct mutex work_mutex;

};



/*
@@ -198,6 +200,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti) 
		m->queue_io = 1;

		INIT_WORK(&m->process_queued_ios, process_queued_ios);

		INIT_WORK(&m->trigger_event, trigger_event);

		mutex_init(&m->work_mutex);

		m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);

		if (!m->mpio_pool) {

			kfree(m);
@@ -1268,7 +1271,11 @@ static void multipath_presuspend(struct dm_target *ti) 


static void multipath_postsuspend(struct dm_target *ti)

{

	struct multipath *m = ti->private;



	mutex_lock(&m->work_mutex);

	flush_multipath_work();

	mutex_unlock(&m->work_mutex);

}



/*
@@ -1407,51 +1414,61 @@ static int multipath_status(struct dm_target *ti, status_type_t type, 


static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)

{

	int r;

	int r = -EINVAL;

	struct dm_dev *dev;

	struct multipath *m = (struct multipath *) ti->private;

	action_fn action;



	mutex_lock(&m->work_mutex);



	if (argc == 1) {

		if (!strnicmp(argv[0], MESG_STR("queue_if_no_path")))

			return queue_if_no_path(m, 1, 0);

		else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path")))

			return queue_if_no_path(m, 0, 0);

	}



	if (argc != 2)

		goto error;



	if (!strnicmp(argv[0], MESG_STR("disable_group")))

		return bypass_pg_num(m, argv[1], 1);

	else if (!strnicmp(argv[0], MESG_STR("enable_group")))

		return bypass_pg_num(m, argv[1], 0);

	else if (!strnicmp(argv[0], MESG_STR("switch_group")))

		return switch_pg_num(m, argv[1]);

	else if (!strnicmp(argv[0], MESG_STR("reinstate_path")))

		if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) {

			r = queue_if_no_path(m, 1, 0);

			goto out;

		} else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) {

			r = queue_if_no_path(m, 0, 0);

			goto out;

		}

	}



	if (argc != 2) {

		DMWARN("Unrecognised multipath message received.");

		goto out;

	}



	if (!strnicmp(argv[0], MESG_STR("disable_group"))) {

		r = bypass_pg_num(m, argv[1], 1);

		goto out;

	} else if (!strnicmp(argv[0], MESG_STR("enable_group"))) {

		r = bypass_pg_num(m, argv[1], 0);

		goto out;

	} else if (!strnicmp(argv[0], MESG_STR("switch_group"))) {

		r = switch_pg_num(m, argv[1]);

		goto out;

	} else if (!strnicmp(argv[0], MESG_STR("reinstate_path")))

		action = reinstate_path;

	else if (!strnicmp(argv[0], MESG_STR("fail_path")))

		action = fail_path;

	else

		goto error;

	else {

		DMWARN("Unrecognised multipath message received.");

		goto out;

	}



	r = dm_get_device(ti, argv[1], ti->begin, ti->len,

			  dm_table_get_mode(ti->table), &dev);

	if (r) {

		DMWARN("message: error getting device %s",

		       argv[1]);

		return -EINVAL;

		goto out;

	}



	r = action_dev(m, dev, action);



	dm_put_device(ti, dev);



out:

	mutex_unlock(&m->work_mutex);

	return r;



error:

	DMWARN("Unrecognised multipath message received.");

	return -EINVAL;

}



static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,