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path: root/drivers/md/dm.c
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Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 73f28802dc7a..9b641b38b857 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2616,6 +2616,19 @@ void dm_get(struct mapped_device *md)
BUG_ON(test_bit(DMF_FREEING, &md->flags));
}
+int dm_hold(struct mapped_device *md)
+{
+ spin_lock(&_minor_lock);
+ if (test_bit(DMF_FREEING, &md->flags)) {
+ spin_unlock(&_minor_lock);
+ return -EBUSY;
+ }
+ dm_get(md);
+ spin_unlock(&_minor_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_hold);
+
const char *dm_device_name(struct mapped_device *md)
{
return md->name;
@@ -2638,10 +2651,16 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
if (dm_request_based(md))
flush_kthread_worker(&md->kworker);
+ /*
+ * Take suspend_lock so that presuspend and postsuspend methods
+ * do not race with internal suspend.
+ */
+ mutex_lock(&md->suspend_lock);
if (!dm_suspended_md(md)) {
dm_table_presuspend_targets(map);
dm_table_postsuspend_targets(map);
}
+ mutex_unlock(&md->suspend_lock);
/* dm_put_live_table must be before msleep, otherwise deadlock is possible */
dm_put_live_table(md, srcu_idx);
@@ -3115,6 +3134,7 @@ void dm_internal_suspend_fast(struct mapped_device *md)
flush_workqueue(md->wq);
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
}
+EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
void dm_internal_resume_fast(struct mapped_device *md)
{
@@ -3126,6 +3146,7 @@ void dm_internal_resume_fast(struct mapped_device *md)
done:
mutex_unlock(&md->suspend_lock);
}
+EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
/*-----------------------------------------------------------------
* Event notification.