locking/atomic, kref: Add kref_read()

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 36d2b9f4e836..436baa66f701 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1535,7 +1535,7 @@ static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
 {
         dout("%s: obj %p (was %d)\n", __func__, obj_request,
-                atomic_read(&obj_request->kref.refcount));
+                kref_read(&obj_request->kref));
         kref_get(&obj_request->kref);
 }
 
@@ -1544,14 +1544,14 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
 {
         rbd_assert(obj_request != NULL);
         dout("%s: obj %p (was %d)\n", __func__, obj_request,
-                atomic_read(&obj_request->kref.refcount));
+                kref_read(&obj_request->kref));
         kref_put(&obj_request->kref, rbd_obj_request_destroy);
 }
 
 static void rbd_img_request_get(struct rbd_img_request *img_request)
 {
         dout("%s: img %p (was %d)\n", __func__, img_request,
-             atomic_read(&img_request->kref.refcount));
+             kref_read(&img_request->kref));
         kref_get(&img_request->kref);
 }
 
@@ -1562,7 +1562,7 @@ static void rbd_img_request_put(struct rbd_img_request *img_request)
 {
         rbd_assert(img_request != NULL);
         dout("%s: img %p (was %d)\n", __func__, img_request,
-                atomic_read(&img_request->kref.refcount));
+                kref_read(&img_request->kref));
         if (img_request_child_test(img_request))
                 kref_put(&img_request->kref, rbd_parent_request_destroy);
         else