ceph: use kref for ceph_osd_request

Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/osd_client.c

@@ -77,12 +77,12 @@ static void calc_layout(struct ceph_osd_client *osdc,
 /*
  * requests
  */
-void ceph_osdc_put_request(struct ceph_osd_request *req)
+void ceph_osdc_release_request(struct kref *kref)
 {
-	dout("osdc put_request %p %d -> %d\n", req, atomic_read(&req->r_ref),
-	     atomic_read(&req->r_ref)-1);
-	BUG_ON(atomic_read(&req->r_ref) <= 0);
-	if (atomic_dec_and_test(&req->r_ref)) {
+	struct ceph_osd_request *req = container_of(kref,
+						    struct ceph_osd_request,
+						    r_kref);
+
 	if (req->r_request)
 		ceph_msg_put(req->r_request);
 	if (req->r_reply)
@@ -95,7 +95,6 @@ void ceph_osdc_put_request(struct ceph_osd_request *req)
 		mempool_free(req, req->r_osdc->req_mempool);
 	else
 		kfree(req);
-	}
 }
 
 /*
@@ -149,7 +148,7 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
 
 	req->r_osdc = osdc;
 	req->r_mempool = use_mempool;
-	atomic_set(&req->r_ref, 1);
+	kref_init(&req->r_kref);
 	init_completion(&req->r_completion);
 	init_completion(&req->r_safe_completion);
 	INIT_LIST_HEAD(&req->r_unsafe_item);

fs/ceph/osd_client.h

@@ -2,6 +2,7 @@
 #define _FS_CEPH_OSD_CLIENT_H
 
 #include <linux/completion.h>
+#include <linux/kref.h>
 #include <linux/mempool.h>
 #include <linux/rbtree.h>
 
@@ -49,7 +50,7 @@ struct ceph_osd_request {
 	int r_prepared_pages, r_got_reply;
 
 	struct ceph_osd_client *r_osdc;
-	atomic_t          r_ref;
+	struct kref       r_kref;
 	bool              r_mempool;
 	struct completion r_completion, r_safe_completion;
 	ceph_osdc_callback_t r_callback, r_safe_callback;
@@ -118,9 +119,13 @@ extern struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *,
 
 static inline void ceph_osdc_get_request(struct ceph_osd_request *req)
 {
-	atomic_inc(&req->r_ref);
+	kref_get(&req->r_kref);
+}
+extern void ceph_osdc_release_request(struct kref *kref);
+static inline void ceph_osdc_put_request(struct ceph_osd_request *req)
+{
+	kref_put(&req->r_kref, ceph_osdc_release_request);
 }
-extern void ceph_osdc_put_request(struct ceph_osd_request *req);
 
 extern int ceph_osdc_start_request(struct ceph_osd_client *osdc,
 				   struct ceph_osd_request *req,