dm mpath: wait for pg_init completion when suspending

When suspending the device we must wait for all I/O to complete, but
pg-init may be still in progress even after flushing the workqueue
for kmpath_handlerd in multipath_postsuspend.

This patch waits for pg-init completion correctly in
multipath_postsuspend().

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Kiyoshi Ueda 2010-03-06 02:32:13 +00:00 committed by Alasdair G Kergon
parent d0259bf0ee
commit 2bded7bd7e

View file

@ -69,6 +69,7 @@ struct multipath {
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
unsigned pg_init_in_progress; /* Only one pg_init allowed at once */
wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */
unsigned nr_valid_paths; /* Total number of usable paths */
struct pgpath *current_pgpath;
@ -200,6 +201,7 @@ 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);
init_waitqueue_head(&m->pg_init_wait);
mutex_init(&m->work_mutex);
m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
if (!m->mpio_pool) {
@ -891,9 +893,34 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
return r;
}
static void flush_multipath_work(void)
static void multipath_wait_for_pg_init_completion(struct multipath *m)
{
DECLARE_WAITQUEUE(wait, current);
unsigned long flags;
add_wait_queue(&m->pg_init_wait, &wait);
while (1) {
set_current_state(TASK_UNINTERRUPTIBLE);
spin_lock_irqsave(&m->lock, flags);
if (!m->pg_init_in_progress) {
spin_unlock_irqrestore(&m->lock, flags);
break;
}
spin_unlock_irqrestore(&m->lock, flags);
io_schedule();
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&m->pg_init_wait, &wait);
}
static void flush_multipath_work(struct multipath *m)
{
flush_workqueue(kmpath_handlerd);
multipath_wait_for_pg_init_completion(m);
flush_workqueue(kmultipathd);
flush_scheduled_work();
}
@ -902,7 +929,7 @@ static void multipath_dtr(struct dm_target *ti)
{
struct multipath *m = ti->private;
flush_multipath_work();
flush_multipath_work(m);
free_multipath(m);
}
@ -1193,6 +1220,11 @@ static void pg_init_done(void *data, int errors)
queue_work(kmultipathd, &m->process_queued_ios);
/*
* Wake up any thread waiting to suspend.
*/
wake_up(&m->pg_init_wait);
out:
spin_unlock_irqrestore(&m->lock, flags);
}
@ -1281,7 +1313,7 @@ static void multipath_postsuspend(struct dm_target *ti)
struct multipath *m = ti->private;
mutex_lock(&m->work_mutex);
flush_multipath_work();
flush_multipath_work(m);
mutex_unlock(&m->work_mutex);
}