dm: disable interrupt when taking map_lock
This patch disables interrupt when taking map_lock to avoid
lockdep warnings in request-based dm.
request-based dm takes map_lock after taking queue_lock with
disabling interrupt:
spin_lock_irqsave(queue_lock)
q->request_fn() == dm_request_fn()
=> dm_get_table()
=> read_lock(map_lock)
while queue_lock could be (but isn't) taken in interrupt context.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 00c7688..3c6d4ee 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -512,12 +512,13 @@
struct dm_table *dm_get_table(struct mapped_device *md)
{
struct dm_table *t;
+ unsigned long flags;
- read_lock(&md->map_lock);
+ read_lock_irqsave(&md->map_lock, flags);
t = md->map;
if (t)
dm_table_get(t);
- read_unlock(&md->map_lock);
+ read_unlock_irqrestore(&md->map_lock, flags);
return t;
}
@@ -1910,6 +1911,7 @@
{
struct request_queue *q = md->queue;
sector_t size;
+ unsigned long flags;
size = dm_table_get_size(t);
@@ -1940,10 +1942,10 @@
__bind_mempools(md, t);
- write_lock(&md->map_lock);
+ write_lock_irqsave(&md->map_lock, flags);
md->map = t;
dm_table_set_restrictions(t, q, limits);
- write_unlock(&md->map_lock);
+ write_unlock_irqrestore(&md->map_lock, flags);
return 0;
}
@@ -1951,14 +1953,15 @@
static void __unbind(struct mapped_device *md)
{
struct dm_table *map = md->map;
+ unsigned long flags;
if (!map)
return;
dm_table_event_callback(map, NULL, NULL);
- write_lock(&md->map_lock);
+ write_lock_irqsave(&md->map_lock, flags);
md->map = NULL;
- write_unlock(&md->map_lock);
+ write_unlock_irqrestore(&md->map_lock, flags);
dm_table_destroy(map);
}