libceph: make ceph_osdc_put_request() accept NULL

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/addr.c

@@ -1099,7 +1099,6 @@ static int ceph_writepages_start(struct address_space *mapping,
 		mapping->writeback_index = index;
 
 out:
-	if (req)
 	ceph_osdc_put_request(req);
 	ceph_put_snap_context(snapc);
 	dout("writepages done, rc = %d\n", rc);
@@ -1824,9 +1823,7 @@ static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
 out_unlock:
 	up_write(&mdsc->pool_perm_rwsem);
 
-	if (rd_req)
 	ceph_osdc_put_request(rd_req);
-	if (wr_req)
 	ceph_osdc_put_request(wr_req);
 out:
 	if (!err)

net/ceph/osd_client.c

@@ -354,9 +354,11 @@ EXPORT_SYMBOL(ceph_osdc_get_request);
 
 void ceph_osdc_put_request(struct ceph_osd_request *req)
 {
+	if (req) {
 		dout("%s %p (was %d)\n", __func__, req,
 		     atomic_read(&req->r_kref.refcount));
 		kref_put(&req->r_kref, ceph_osdc_release_request);
+	}
 }
 EXPORT_SYMBOL(ceph_osdc_put_request);