NLM: Add nlmclnt_release_call

Add a helper function to simplify the freeing of NLM client requests.

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

4 files changed, 129 insertions, 199 deletions

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 7a23986..3f8ad7c 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -152,9 +152,8 @@ static void nlmclnt_release_lockargs(struct nlm_rqst *req)
 int
 nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
 {
-	struct nfs_server	*nfssrv = NFS_SERVER(inode);
 	struct nlm_host		*host;
-	struct nlm_rqst		reqst, *call = &reqst;
+	struct nlm_rqst		*call;
 	sigset_t		oldset;
 	unsigned long		flags;
 	int			status, proto, vers;
@@ -168,23 +167,17 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
 	/* Retrieve transport protocol from NFS client */
 	proto = NFS_CLIENT(inode)->cl_xprt->prot;
 
-	if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
+	host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers);
+	if (host == NULL)
 		return -ENOLCK;
 
-	/* Create RPC client handle if not there, and copy soft
-	 * and intr flags from NFS client. */
-	if (host->h_rpcclnt == NULL) {
-		struct rpc_clnt	*clnt;
+	call = nlm_alloc_call(host);
+	if (call == NULL)
+		return -ENOMEM;
 
-		/* Bind an rpc client to this host handle (does not
-		 * perform a portmapper lookup) */
-		if (!(clnt = nlm_bind_host(host))) {
-			status = -ENOLCK;
-			goto done;
-		}
-		clnt->cl_softrtry = nfssrv->client->cl_softrtry;
-		clnt->cl_intr = nfssrv->client->cl_intr;
-	}
+	nlmclnt_locks_init_private(fl, host);
+	/* Set up the argument struct */
+	nlmclnt_setlockargs(call, fl);
 
 	/* Keep the old signal mask */
 	spin_lock_irqsave(&current->sighand->siglock, flags);
@@ -197,26 +190,10 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
 	    && (current->flags & PF_EXITING)) {
 		sigfillset(&current->blocked);	/* Mask all signals */
 		recalc_sigpending();
-		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
-		call = nlmclnt_alloc_call();
-		if (!call) {
-			status = -ENOMEM;
-			goto out_restore;
-		}
 		call->a_flags = RPC_TASK_ASYNC;
-	} else {
-		spin_unlock_irqrestore(&current->sighand->siglock, flags);
-		memset(call, 0, sizeof(*call));
-		locks_init_lock(&call->a_args.lock.fl);
-		locks_init_lock(&call->a_res.lock.fl);
 	}
-	call->a_host = host;
-
-	nlmclnt_locks_init_private(fl, host);
-
-	/* Set up the argument struct */
-	nlmclnt_setlockargs(call, fl);
+	spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
 	if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
 		if (fl->fl_type != F_UNLCK) {
@@ -229,24 +206,26 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
 	else
 		status = -EINVAL;
 
- out_restore:
+	fl->fl_ops->fl_release_private(fl);
+	fl->fl_ops = NULL;
+
 	spin_lock_irqsave(&current->sighand->siglock, flags);
 	current->blocked = oldset;
 	recalc_sigpending();
 	spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
-done:
 	dprintk("lockd: clnt proc returns %d\n", status);
-	nlm_release_host(host);
 	return status;
 }
 EXPORT_SYMBOL(nlmclnt_proc);
 
 /*
  * Allocate an NLM RPC call struct
+ *
+ * Note: the caller must hold a reference to host. In case of failure,
+ * this reference will be released.
  */
-struct nlm_rqst *
-nlmclnt_alloc_call(void)
+struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
 {
 	struct nlm_rqst	*call;
 
@@ -255,16 +234,30 @@ nlmclnt_alloc_call(void)
 		if (call != NULL) {
 			locks_init_lock(&call->a_args.lock.fl);
 			locks_init_lock(&call->a_res.lock.fl);
+			call->a_host = host;
 			return call;
 		}
 		if (signalled())
 			break;
-		printk("nlmclnt_alloc_call: failed, waiting for memory\n");
+		printk("nlm_alloc_call: failed, waiting for memory\n");
 		schedule_timeout_interruptible(5*HZ);
 	}
+	nlm_release_host(host);
 	return NULL;
 }
 
+void nlm_release_call(struct nlm_rqst *call)
+{
+	nlm_release_host(call->a_host);
+	nlmclnt_release_lockargs(call);
+	kfree(call);
+}
+
+static void nlmclnt_rpc_release(void *data)
+{
+	return nlm_release_call(data);
+}
+
 static int nlm_wait_on_grace(wait_queue_head_t *queue)
 {
 	DEFINE_WAIT(wait);
@@ -361,7 +354,7 @@ in_grace_period:
 /*
  * Generic NLM call, async version.
  */
-int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
 {
 	struct nlm_host	*host = req->a_host;
 	struct rpc_clnt	*clnt;
@@ -369,48 +362,23 @@ int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops
 		.rpc_argp	= &req->a_args,
 		.rpc_resp	= &req->a_res,
 	};
-	int		status;
-
-	dprintk("lockd: call procedure %d on %s (async)\n",
-			(int)proc, host->h_name);
-
-	/* If we have no RPC client yet, create one. */
-	if ((clnt = nlm_bind_host(host)) == NULL)
-		return -ENOLCK;
-	msg.rpc_proc = &clnt->cl_procinfo[proc];
-
-        /* bootstrap and kick off the async RPC call */
-        status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
-
-	return status;
-}
-
-static int nlmclnt_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
-{
-	struct nlm_host	*host = req->a_host;
-	struct rpc_clnt	*clnt;
-	struct nlm_args	*argp = &req->a_args;
-	struct nlm_res	*resp = &req->a_res;
-	struct rpc_message msg = {
-		.rpc_argp	= argp,
-		.rpc_resp	= resp,
-	};
-	int		status;
+	int status = -ENOLCK;
 
 	dprintk("lockd: call procedure %d on %s (async)\n",
 			(int)proc, host->h_name);
 
 	/* If we have no RPC client yet, create one. */
-	if ((clnt = nlm_bind_host(host)) == NULL)
-		return -ENOLCK;
+	clnt = nlm_bind_host(host);
+	if (clnt == NULL)
+		goto out_err;
 	msg.rpc_proc = &clnt->cl_procinfo[proc];
 
-	/* Increment host refcount */
-	nlm_get_host(host);
         /* bootstrap and kick off the async RPC call */
         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
-	if (status < 0)
-		nlm_release_host(host);
+	if (status == 0)
+		return 0;
+out_err:
+	nlm_release_call(req);
 	return status;
 }
 
@@ -423,26 +391,28 @@ nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
 	int	status;
 
 	status = nlmclnt_call(req, NLMPROC_TEST);
-	nlmclnt_release_lockargs(req);
 	if (status < 0)
-		return status;
+		goto out;
 
-	status = req->a_res.status;
-	if (status == NLM_LCK_GRANTED) {
-		fl->fl_type = F_UNLCK;
-	} if (status == NLM_LCK_DENIED) {
-		/*
-		 * Report the conflicting lock back to the application.
-		 */
-		fl->fl_start = req->a_res.lock.fl.fl_start;
-		fl->fl_end = req->a_res.lock.fl.fl_start;
-		fl->fl_type = req->a_res.lock.fl.fl_type;
-		fl->fl_pid = 0;
-	} else {
-		return nlm_stat_to_errno(req->a_res.status);
+	switch (req->a_res.status) {
+		case NLM_LCK_GRANTED:
+			fl->fl_type = F_UNLCK;
+			break;
+		case NLM_LCK_DENIED:
+			/*
+			 * Report the conflicting lock back to the application.
+			 */
+			fl->fl_start = req->a_res.lock.fl.fl_start;
+			fl->fl_end = req->a_res.lock.fl.fl_start;
+			fl->fl_type = req->a_res.lock.fl.fl_type;
+			fl->fl_pid = 0;
+			break;
+		default:
+			status = nlm_stat_to_errno(req->a_res.status);
 	}
-
-	return 0;
+out:
+	nlm_release_call(req);
+	return status;
 }
 
 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
@@ -560,7 +530,7 @@ out_unblock:
 	if (resp->status == NLM_LCK_BLOCKED)
 		nlmclnt_cancel(host, req->a_args.block, fl);
 out:
-	nlmclnt_release_lockargs(req);
+	nlm_release_call(req);
 	return status;
 }
 
@@ -623,32 +593,24 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
 	 */
 	do_vfs_lock(fl);
 
-	if (req->a_flags & RPC_TASK_ASYNC) {
-		status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
-					&nlmclnt_unlock_ops);
-		/* Hrmf... Do the unlock early since locks_remove_posix()
-		 * really expects us to free the lock synchronously */
-		if (status < 0) {
-			nlmclnt_release_lockargs(req);
-			kfree(req);
-		}
-		return status;
-	}
+	if (req->a_flags & RPC_TASK_ASYNC)
+		return nlm_async_call(req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
 
 	status = nlmclnt_call(req, NLMPROC_UNLOCK);
-	nlmclnt_release_lockargs(req);
 	if (status < 0)
-		return status;
+		goto out;
 
+	status = 0;
 	if (resp->status == NLM_LCK_GRANTED)
-		return 0;
+		goto out;
 
 	if (resp->status != NLM_LCK_DENIED_NOLOCKS)
 		printk("lockd: unexpected unlock status: %d\n", resp->status);
-
 	/* What to do now? I'm out of my depth... */
-
-	return -ENOLCK;
+	status = -ENOLCK;
+out:
+	nlm_release_call(req);
+	return status;
 }
 
 static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
@@ -670,9 +632,6 @@ static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
 	if (status != NLM_LCK_GRANTED)
 		printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
 die:
-	nlm_release_host(req->a_host);
-	nlmclnt_release_lockargs(req);
-	kfree(req);
 	return;
  retry_rebind:
 	nlm_rebind_host(req->a_host);
@@ -682,6 +641,7 @@ die:
 
 static const struct rpc_call_ops nlmclnt_unlock_ops = {
 	.rpc_call_done = nlmclnt_unlock_callback,
+	.rpc_release = nlmclnt_rpc_release,
 };
 
 /*
@@ -703,20 +663,15 @@ static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl
 	recalc_sigpending();
 	spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
-	req = nlmclnt_alloc_call();
+	req = nlm_alloc_call(nlm_get_host(host));
 	if (!req)
 		return -ENOMEM;
-	req->a_host  = host;
 	req->a_flags = RPC_TASK_ASYNC;
 
 	nlmclnt_setlockargs(req, fl);
 	req->a_args.block = block;
 
-	status = nlmclnt_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
-	if (status < 0) {
-		nlmclnt_release_lockargs(req);
-		kfree(req);
-	}
+	status = nlm_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
 
 	spin_lock_irqsave(&current->sighand->siglock, flags);
 	current->blocked = oldset;
@@ -757,9 +712,6 @@ static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
 	}
 
 die:
-	nlm_release_host(req->a_host);
-	nlmclnt_release_lockargs(req);
-	kfree(req);
 	return;
 
 retry_cancel:
@@ -773,6 +725,7 @@ retry_cancel:
 
 static const struct rpc_call_ops nlmclnt_cancel_ops = {
 	.rpc_call_done = nlmclnt_cancel_callback,
+	.rpc_release = nlmclnt_rpc_release,
 };
 
 /*
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index ac4a700..cb51c70 100644
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -480,43 +480,37 @@ nlm4svc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_res *resp)
 	struct nlm_host	*host;
 	struct nlm_rqst	*call;
 
-	if (!(call = nlmclnt_alloc_call()))
+	host = nlmsvc_lookup_host(rqstp);
+	if (host == NULL)
 		return rpc_system_err;
 
-	host = nlmsvc_lookup_host(rqstp);
-	if (!host) {
-		kfree(call);
+	call = nlm_alloc_call(host);
+	if (call == NULL)
 		return rpc_system_err;
-	}
+
 
 	call->a_flags = RPC_TASK_ASYNC;
-	call->a_host  = host;
 	memcpy(&call->a_args, resp, sizeof(*resp));
 
-	if (nlmsvc_async_call(call, proc, &nlm4svc_callback_ops) < 0)
-		goto error;
-
+	if (nlm_async_call(call, proc, &nlm4svc_callback_ops) < 0)
+		return rpc_system_err;
 	return rpc_success;
- error:
-	kfree(call);
-	nlm_release_host(host);
-	return rpc_system_err;
 }
 
 static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
 {
-	struct nlm_rqst	*call = data;
+	dprintk("lockd: %4d callback returned %d\n", task->tk_pid,
+			-task->tk_status);
+}
 
-	if (task->tk_status < 0) {
-		dprintk("lockd: %4d callback failed (errno = %d)\n",
-					task->tk_pid, -task->tk_status);
-	}
-	nlm_release_host(call->a_host);
-	kfree(call);
+static void nlm4svc_callback_release(void *data)
+{
+	nlm_release_call(data);
 }
 
 static const struct rpc_call_ops nlm4svc_callback_ops = {
 	.rpc_call_done = nlm4svc_callback_exit,
+	.rpc_release = nlm4svc_callback_release,
 };
 
 /*
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index a95d260..185bf7e 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -117,12 +117,12 @@ nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock, int remove)
 				(long long)lock->fl.fl_start,
 				(long long)lock->fl.fl_end, lock->fl.fl_type);
 	for (head = &nlm_blocked; (block = *head) != 0; head = &block->b_next) {
-		fl = &block->b_call.a_args.lock.fl;
+		fl = &block->b_call->a_args.lock.fl;
 		dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n",
 				block->b_file, fl->fl_pid,
 				(long long)fl->fl_start,
 				(long long)fl->fl_end, fl->fl_type,
-				nlmdbg_cookie2a(&block->b_call.a_args.cookie));
+				nlmdbg_cookie2a(&block->b_call->a_args.cookie));
 		if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) {
 			if (remove) {
 				*head = block->b_next;
@@ -156,7 +156,7 @@ nlmsvc_find_block(struct nlm_cookie *cookie,  struct sockaddr_in *sin)
 	for (block = nlm_blocked; block; block = block->b_next) {
 		dprintk("cookie: head of blocked queue %p, block %p\n", 
 			nlm_blocked, block);
-		if (nlm_cookie_match(&block->b_call.a_args.cookie,cookie)
+		if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie)
 				&& nlm_cmp_addr(sin, &block->b_host->h_addr))
 			break;
 	}
@@ -182,28 +182,30 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
 {
 	struct nlm_block	*block;
 	struct nlm_host		*host;
-	struct nlm_rqst		*call;
+	struct nlm_rqst		*call = NULL;
 
 	/* Create host handle for callback */
 	host = nlmsvc_lookup_host(rqstp);
 	if (host == NULL)
 		return NULL;
 
+	call = nlm_alloc_call(host);
+	if (call == NULL)
+		return NULL;
+
 	/* Allocate memory for block, and initialize arguments */
-	if (!(block = (struct nlm_block *) kmalloc(sizeof(*block), GFP_KERNEL)))
+	block = kzalloc(sizeof(*block), GFP_KERNEL);
+	if (block == NULL)
 		goto failed;
-	memset(block, 0, sizeof(*block));
-	locks_init_lock(&block->b_call.a_args.lock.fl);
-	locks_init_lock(&block->b_call.a_res.lock.fl);
 	kref_init(&block->b_count);
 
-	if (!nlmsvc_setgrantargs(&block->b_call, lock))
+	if (!nlmsvc_setgrantargs(call, lock))
 		goto failed_free;
 
 	/* Set notifier function for VFS, and init args */
-	block->b_call.a_args.lock.fl.fl_flags |= FL_SLEEP;
-	block->b_call.a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
-	block->b_call.a_args.cookie = *cookie;	/* see above */
+	call->a_args.lock.fl.fl_flags |= FL_SLEEP;
+	call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
+	call->a_args.cookie = *cookie;	/* see above */
 
 	dprintk("lockd: created block %p...\n", block);
 
@@ -217,16 +219,16 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
 	file->f_blocks  = block;
 
 	/* Set up RPC arguments for callback */
-	call = &block->b_call;
-	call->a_host    = host;
+	block->b_call = call;
 	call->a_flags   = RPC_TASK_ASYNC;
+	call->a_block = block;
 
 	return block;
 
 failed_free:
 	kfree(block);
 failed:
-	nlm_release_host(host);
+	nlm_release_call(call);
 	return NULL;
 }
 
@@ -242,7 +244,7 @@ static int nlmsvc_unlink_block(struct nlm_block *block)
 	dprintk("lockd: unlinking block %p...\n", block);
 
 	/* Remove block from list */
-	status = posix_unblock_lock(block->b_file->f_file, &block->b_call.a_args.lock.fl);
+	status = posix_unblock_lock(block->b_file->f_file, &block->b_call->a_args.lock.fl);
 	nlmsvc_remove_block(block);
 	return status;
 }
@@ -263,9 +265,8 @@ static void nlmsvc_free_block(struct kref *kref)
 		}
 	}
 
-	if (block->b_host)
-		nlm_release_host(block->b_host);
-	nlmsvc_freegrantargs(&block->b_call);
+	nlmsvc_freegrantargs(block->b_call);
+	nlm_release_call(block->b_call);
 	kfree(block);
 }
 
@@ -316,10 +317,8 @@ static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
 
 	if (lock->oh.len > NLMCLNT_OHSIZE) {
 		void *data = kmalloc(lock->oh.len, GFP_KERNEL);
-		if (!data) {
-			nlmsvc_freegrantargs(call);
+		if (!data)
 			return 0;
-		}
 		call->a_args.lock.oh.data = (u8 *) data;
 	}
 
@@ -329,17 +328,8 @@ static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
 
 static void nlmsvc_freegrantargs(struct nlm_rqst *call)
 {
-	struct file_lock *fl = &call->a_args.lock.fl;
-	/*
-	 * Check whether we allocated memory for the owner.
-	 */
-	if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
+	if (call->a_args.lock.oh.data != call->a_owner)
 		kfree(call->a_args.lock.oh.data);
-	}
-	if (fl->fl_ops && fl->fl_ops->fl_release_private)
-		fl->fl_ops->fl_release_private(fl);
-	if (fl->fl_lmops && fl->fl_lmops->fl_release_private)
-		fl->fl_lmops->fl_release_private(fl);
 }
 
 /*
@@ -371,9 +361,9 @@ again:
 	block = nlmsvc_lookup_block(file, lock, 0);
 	if (block == NULL) {
 		if (newblock != NULL)
-			lock = &newblock->b_call.a_args.lock;
+			lock = &newblock->b_call->a_args.lock;
 	} else
-		lock = &block->b_call.a_args.lock;
+		lock = &block->b_call->a_args.lock;
 
 	error = posix_lock_file(file->f_file, &lock->fl);
 	lock->fl.fl_flags &= ~FL_SLEEP;
@@ -523,7 +513,7 @@ nlmsvc_notify_blocked(struct file_lock *fl)
 
 	dprintk("lockd: VFS unblock notification for block %p\n", fl);
 	for (bp = &nlm_blocked; (block = *bp) != 0; bp = &block->b_next) {
-		if (nlm_compare_locks(&block->b_call.a_args.lock.fl, fl)) {
+		if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
 			nlmsvc_insert_block(block, 0);
 			svc_wake_up(block->b_daemon);
 			return;
@@ -558,7 +548,7 @@ static void
 nlmsvc_grant_blocked(struct nlm_block *block)
 {
 	struct nlm_file		*file = block->b_file;
-	struct nlm_lock		*lock = &block->b_call.a_args.lock;
+	struct nlm_lock		*lock = &block->b_call->a_args.lock;
 	int			error;
 
 	dprintk("lockd: grant blocked lock %p\n", block);
@@ -606,7 +596,7 @@ callback:
 
 	/* Call the client */
 	kref_get(&block->b_count);
-	if (nlmsvc_async_call(&block->b_call, NLMPROC_GRANTED_MSG,
+	if (nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
 						&nlmsvc_grant_ops) < 0)
 		nlmsvc_release_block(block);
 out_unlock:
@@ -624,7 +614,7 @@ out_unlock:
 static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
 {
 	struct nlm_rqst		*call = data;
-	struct nlm_block	*block = container_of(call, struct nlm_block, b_call);
+	struct nlm_block	*block = call->a_block;
 	unsigned long		timeout;
 
 	dprintk("lockd: GRANT_MSG RPC callback\n");
diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index 4986fbe..956d1d7 100644
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -505,43 +505,36 @@ nlmsvc_callback(struct svc_rqst *rqstp, u32 proc, struct nlm_res *resp)
 	struct nlm_host	*host;
 	struct nlm_rqst	*call;
 
-	if (!(call = nlmclnt_alloc_call()))
+	host = nlmsvc_lookup_host(rqstp);
+	if (host == NULL)
 		return rpc_system_err;
 
-	host = nlmsvc_lookup_host(rqstp);
-	if (!host) {
-		kfree(call);
+	call = nlm_alloc_call(host);
+	if (call == NULL)
 		return rpc_system_err;
-	}
 
 	call->a_flags = RPC_TASK_ASYNC;
-	call->a_host  = host;
 	memcpy(&call->a_args, resp, sizeof(*resp));
 
-	if (nlmsvc_async_call(call, proc, &nlmsvc_callback_ops) < 0)
-		goto error;
-
+	if (nlm_async_call(call, proc, &nlmsvc_callback_ops) < 0)
+		return rpc_system_err;
 	return rpc_success;
- error:
-	nlm_release_host(host);
-	kfree(call);
-	return rpc_system_err;
 }
 
 static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
 {
-	struct nlm_rqst	*call = data;
+	dprintk("lockd: %4d callback returned %d\n", task->tk_pid,
+			-task->tk_status);
+}
 
-	if (task->tk_status < 0) {
-		dprintk("lockd: %4d callback failed (errno = %d)\n",
-					task->tk_pid, -task->tk_status);
-	}
-	nlm_release_host(call->a_host);
-	kfree(call);
+static void nlmsvc_callback_release(void *data)
+{
+	nlm_release_call(data);
 }
 
 static const struct rpc_call_ops nlmsvc_callback_ops = {
 	.rpc_call_done = nlmsvc_callback_exit,
+	.rpc_release = nlmsvc_callback_release,
 };
 
 /*