SUNRPC: Convert rpc_clnt->cl_users to a kref

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

5 files changed, 35 insertions, 44 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 96070bff93fc..c252a1c95857 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -161,15 +161,9 @@ nlm_destroy_host(struct nlm_host *host)
          */
         nsm_unmonitor(host);
 
-        if ((clnt = host->h_rpcclnt) != NULL) {
-                if (atomic_read(&clnt->cl_users)) {
-                        printk(KERN_WARNING
-                                "lockd: active RPC handle\n");
-                        clnt->cl_dead = 1;
-                } else {
-                        rpc_destroy_client(host->h_rpcclnt);
-                }
-        }
+        clnt = host->h_rpcclnt;
+        if (clnt != NULL)
+                rpc_shutdown_client(clnt);
         kfree(host);
 }
 
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 2f4b520a7419..003d8ea70c19 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -24,8 +24,8 @@ struct rpc_inode;
  * The high-level client handle
  */
 struct rpc_clnt {
+        struct kref             cl_kref;        /* Number of references */
         atomic_t                cl_count;       /* Number of clones */
-        atomic_t                cl_users;       /* number of references */
         struct list_head        cl_clients;     /* Global list of clients */
         struct list_head        cl_tasks;       /* List of tasks */
         spinlock_t              cl_lock;        /* spinlock */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 424dfdc6862c..254a6e1a5770 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -121,7 +121,6 @@ static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, s
         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
         if (!clnt)
                 goto out_err;
-        atomic_set(&clnt->cl_users, 0);
         atomic_set(&clnt->cl_count, 1);
         clnt->cl_parent = clnt;
 
@@ -157,6 +156,8 @@ static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, s
         clnt->cl_rtt = &clnt->cl_rtt_default;
         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 
+        kref_init(&clnt->cl_kref);
+
         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
         if (err < 0)
                 goto out_no_path;
@@ -272,10 +273,10 @@ rpc_clone_client(struct rpc_clnt *clnt)
         if (!new)
                 goto out_no_clnt;
         atomic_set(&new->cl_count, 1);
-        atomic_set(&new->cl_users, 0);
         new->cl_metrics = rpc_alloc_iostats(clnt);
         if (new->cl_metrics == NULL)
                 goto out_no_stats;
+        kref_init(&new->cl_kref);
         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
         if (err != 0)
                 goto out_no_path;
@@ -311,40 +312,28 @@ out_no_clnt:
 int
 rpc_shutdown_client(struct rpc_clnt *clnt)
 {
-        dprintk("RPC:       shutting down %s client for %s, tasks=%d\n",
-                        clnt->cl_protname, clnt->cl_server,
-                        atomic_read(&clnt->cl_users));
+        dprintk("RPC:       shutting down %s client for %s\n",
+                        clnt->cl_protname, clnt->cl_server);
 
-        while (atomic_read(&clnt->cl_users) > 0) {
+        while (!list_empty(&clnt->cl_tasks)) {
                 /* Don't let rpc_release_client destroy us */
                 clnt->cl_oneshot = 0;
                 clnt->cl_dead = 0;
                 rpc_killall_tasks(clnt);
                 wait_event_timeout(destroy_wait,
-                        !atomic_read(&clnt->cl_users), 1*HZ);
-        }
-
-        if (atomic_read(&clnt->cl_users) < 0) {
-                printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
-                                clnt, atomic_read(&clnt->cl_users));
-#ifdef RPC_DEBUG
-                rpc_show_tasks();
-#endif
-                BUG();
+                        list_empty(&clnt->cl_tasks), 1*HZ);
         }
 
         return rpc_destroy_client(clnt);
 }
 
 /*
- * Delete an RPC client
+ * Free an RPC client
  */
-int
-rpc_destroy_client(struct rpc_clnt *clnt)
+static void
+rpc_free_client(struct kref *kref)
 {
-        if (!atomic_dec_and_test(&clnt->cl_count))
-                return 1;
-        BUG_ON(atomic_read(&clnt->cl_users) != 0);
+        struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 
         dprintk("RPC:       destroying %s client for %s\n",
                         clnt->cl_protname, clnt->cl_server);
@@ -368,23 +357,33 @@ out_free:
         clnt->cl_metrics = NULL;
         xprt_put(clnt->cl_xprt);
         kfree(clnt);
-        return 0;
 }
 
 /*
- * Release an RPC client
+ * Release reference to the RPC client
  */
 void
 rpc_release_client(struct rpc_clnt *clnt)
 {
-        dprintk("RPC:       rpc_release_client(%p, %d)\n",
-                        clnt, atomic_read(&clnt->cl_users));
+        dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 
-        if (!atomic_dec_and_test(&clnt->cl_users))
-                return;
-        wake_up(&destroy_wait);
+        if (list_empty(&clnt->cl_tasks))
+                wake_up(&destroy_wait);
         if (clnt->cl_oneshot || clnt->cl_dead)
                 rpc_destroy_client(clnt);
+        kref_put(&clnt->cl_kref, rpc_free_client);
+}
+
+/*
+ * Delete an RPC client
+ */
+int
+rpc_destroy_client(struct rpc_clnt *clnt)
+{
+        if (!atomic_dec_and_test(&clnt->cl_count))
+                return 1;
+        kref_put(&clnt->cl_kref, rpc_free_client);
+        return 0;
 }
 
 /**
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 5887457dc936..826190dacfce 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -344,7 +344,7 @@ rpc_info_open(struct inode *inode, struct file *file)
                 mutex_lock(&inode->i_mutex);
                 clnt = RPC_I(inode)->private;
                 if (clnt) {
-                        atomic_inc(&clnt->cl_users);
+                        kref_get(&clnt->cl_kref);
                         m->private = clnt;
                 } else {
                         single_release(inode, file);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 0e9fbbd4f987..bb12983580a0 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -846,7 +846,7 @@ void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, cons
         task->tk_workqueue = rpciod_workqueue;
 
         if (clnt) {
-                atomic_inc(&clnt->cl_users);
+                kref_get(&clnt->cl_kref);
                 if (clnt->cl_softrtry)
                         task->tk_flags |= RPC_TASK_SOFT;
                 if (!clnt->cl_intr)
@@ -898,9 +898,7 @@ out:
 cleanup:
         /* Check whether to release the client */
         if (clnt) {
-                printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
-                        atomic_read(&clnt->cl_users), clnt->cl_oneshot);
-                atomic_inc(&clnt->cl_users); /* pretend we were used ... */
+                kref_get(&clnt->cl_kref); /* pretend we were used ... */
                 rpc_release_client(clnt);
         }
         goto out;