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: 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 c50abeb380
commit 6380f26f04

View file

@ -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 (!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)
goto error;
if (argc != 2) {
DMWARN("Unrecognised multipath message received.");
goto out;
}
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("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,