block: Dynamically allocate and refcount backing_dev_info
Instead of storing backing_dev_info inside struct request_queue,
allocate it dynamically, reference count it, and free it when the last
reference is dropped. Currently only request_queue holds the reference
but in the following patch we add other users referencing
backing_dev_info.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index e850e76..ad95581 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -10,6 +10,7 @@
#include <linux/flex_proportions.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
+#include <linux/kref.h>
struct page;
struct device;
@@ -144,6 +145,7 @@ struct backing_dev_info {
char *name;
+ struct kref refcnt; /* Reference counter for the structure */
unsigned int capabilities; /* Device capabilities */
unsigned int min_ratio;
unsigned int max_ratio, max_prop_frac;
