dm mpath: prevent io from work queue while suspended

Reject messages that can generate I/O while the device itself
is suspended.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mike Anderson 2009-12-10 23:52:21 +00:00 committed by Alasdair G Kergon
parent 6380f26f04
commit 67a46dad25

View file

@ -95,6 +95,8 @@ struct multipath {
mempool_t *mpio_pool;
struct mutex work_mutex;
unsigned suspended; /* Don't create new I/O internally when set. */
};
/*
@ -1274,6 +1276,7 @@ static void multipath_postsuspend(struct dm_target *ti)
struct multipath *m = ti->private;
mutex_lock(&m->work_mutex);
m->suspended = 1;
flush_multipath_work();
mutex_unlock(&m->work_mutex);
}
@ -1286,6 +1289,10 @@ static void multipath_resume(struct dm_target *ti)
struct multipath *m = (struct multipath *) ti->private;
unsigned long flags;
mutex_lock(&m->work_mutex);
m->suspended = 0;
mutex_unlock(&m->work_mutex);
spin_lock_irqsave(&m->lock, flags);
m->queue_if_no_path = m->saved_queue_if_no_path;
spin_unlock_irqrestore(&m->lock, flags);
@ -1421,6 +1428,11 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
mutex_lock(&m->work_mutex);
if (m->suspended) {
r = -EBUSY;
goto out;
}
if (argc == 1) {
if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) {
r = queue_if_no_path(m, 1, 0);