NFSv4: Clean up nfs_delegation_reap_unclaimed()

Convert nfs_delegation_reap_unclaimed() to use nfs_client_for_each_server()
for efficiency.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/delegation.c

@@ -1092,22 +1092,15 @@ void nfs_delegation_mark_reclaim(struct nfs_client *clp)
 	rcu_read_unlock();
 }
 
-/**
- * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
- * @clp: nfs_client to process
- *
- */
-void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
+static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
+		void __always_unused *data)
 {
 	struct nfs_delegation *delegation;
-	struct nfs_server *server;
 	struct inode *inode;
-
 restart:
 	rcu_read_lock();
-	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
-		list_for_each_entry_rcu(delegation, &server->delegations,
-								super_list) {
+restart_locked:
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
 		if (test_bit(NFS_DELEGATION_INODE_FREEING,
 					&delegation->flags) ||
 		    test_bit(NFS_DELEGATION_RETURNING,
@@ -1115,14 +1108,9 @@ void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
 		    test_bit(NFS_DELEGATION_NEED_RECLAIM,
 					&delegation->flags) == 0)
 			continue;
-			if (!nfs_sb_active(server->super))
-				break; /* continue in outer loop */
 		inode = nfs_delegation_grab_inode(delegation);
-			if (inode == NULL) {
-				rcu_read_unlock();
-				nfs_sb_deactive(server->super);
-				goto restart;
-			}
+		if (inode == NULL)
+			goto restart_locked;
 		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
 		rcu_read_unlock();
 		if (delegation != NULL) {
@@ -1133,12 +1121,22 @@ void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
 			nfs_put_delegation(delegation);
 		}
 		iput(inode);
-			nfs_sb_deactive(server->super);
 		cond_resched();
 		goto restart;
 	}
-	}
 	rcu_read_unlock();
+	return 0;
+}
+
+/**
+ * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
+ * @clp: nfs_client to process
+ *
+ */
+void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
+{
+	nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations,
+			NULL);
 }
 
 static inline bool nfs4_server_rebooted(const struct nfs_client *clp)