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>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 700154e..45d9bf1 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -95,6 +95,8 @@
mempool_t *mpio_pool;
struct mutex work_mutex;
+
+ unsigned suspended; /* Don't create new I/O internally when set. */
};
/*
@@ -1274,6 +1276,7 @@
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 @@
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 @@
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);