Merge tag 'nfs-for-3.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Features include:

   - Full audit of BUG_ON asserts in the NFS, SUNRPC and lockd client
     code.  Remove altogether where possible, and replace with
     WARN_ON_ONCE and appropriate error returns where not.
   - NFSv4.1 client adds session dynamic slot table management.  There
     is matching server side code that has been submitted to Bruce for
     consideration.

     Together, this code allows the server to dynamically manage the
     amount of memory it allocates to the duplicate request cache for
     each client.  It will constantly resize those caches to reserve
     more memory for clients that are hot while shrinking caches for
     those that are quiescent.

  In addition, there are assorted bugfixes for the generic NFS write
  code, fixes to deal with the drop_nlink() warnings, and yet another
  fix for NFSv4 getacl."

* tag 'nfs-for-3.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (106 commits)
  SUNRPC: continue run over clients list on PipeFS event instead of break
  NFS: Don't use SetPageError in the NFS writeback code
  SUNRPC: variable 'svsk' is unused in function bc_send_request
  SUNRPC: Handle ECONNREFUSED in xs_local_setup_socket
  NFSv4.1: Deal effectively with interrupted RPC calls.
  NFSv4.1: Move the RPC timestamp out of the slot.
  NFSv4.1: Try to deal with NFS4ERR_SEQ_MISORDERED.
  NFS: nfs_lookup_revalidate should not trust an inode with i_nlink == 0
  NFS: Fix calls to drop_nlink()
  NFS: Ensure that we always drop inodes that have been marked as stale
  nfs: Remove unused list nfs4_clientid_list
  nfs: Remove duplicate function declaration in internal.h
  NFS: avoid NULL dereference in nfs_destroy_server
  SUNRPC handle EKEYEXPIRED in call_refreshresult
  SUNRPC set gss gc_expiry to full lifetime
  nfs: fix page dirtying in NFS DIO read codepath
  nfs: don't zero out the rest of the page if we hit the EOF on a DIO READ
  NFSv4.1: Be conservative about the client highest slotid
  NFSv4.1: Handle NFS4ERR_BADSLOT errors correctly
  nfs: don't extend writes to cover entire page if pagecache is invalid
  ...

13 files changed, 144 insertions, 74 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 909dc0c31aab..6e5c824b040b 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -192,17 +192,23 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
 	const void *q;
 	unsigned int seclen;
 	unsigned int timeout;
+	unsigned long now = jiffies;
 	u32 window_size;
 	int ret;
 
-	/* First unsigned int gives the lifetime (in seconds) of the cred */
+	/* First unsigned int gives the remaining lifetime in seconds of the
+	 * credential - e.g. the remaining TGT lifetime for Kerberos or
+	 * the -t value passed to GSSD.
+	 */
 	p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 	if (IS_ERR(p))
 		goto err;
 	if (timeout == 0)
 		timeout = GSSD_MIN_TIMEOUT;
-	ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
-	/* Sequence number window. Determines the maximum number of simultaneous requests */
+	ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
+	/* Sequence number window. Determines the maximum number of
+	 * simultaneous requests
+	 */
 	p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 	if (IS_ERR(p))
 		goto err;
@@ -237,9 +243,12 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
 		p = ERR_PTR(ret);
 		goto err;
 	}
+	dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u\n",
+		__func__, ctx->gc_expiry, now, timeout);
 	return q;
 err:
-	dprintk("RPC:       %s returning %ld\n", __func__, -PTR_ERR(p));
+	dprintk("RPC:       %s returns %ld gc_expiry %lu now %lu timeout %u\n",
+		__func__, -PTR_ERR(p), ctx->gc_expiry, now, timeout);
 	return p;
 }
 
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index a9c0bbccad6b..890a29912d5a 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -59,7 +59,7 @@ static void xprt_free_allocation(struct rpc_rqst *req)
 	struct xdr_buf *xbufp;
 
 	dprintk("RPC:        free allocations for req= %p\n", req);
-	BUG_ON(test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
+	WARN_ON_ONCE(test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
 	xbufp = &req->rq_private_buf;
 	free_page((unsigned long)xbufp->head[0].iov_base);
 	xbufp = &req->rq_snd_buf;
@@ -191,7 +191,9 @@ void xprt_destroy_backchannel(struct rpc_xprt *xprt, unsigned int max_reqs)
 
 	dprintk("RPC:        destroy backchannel transport\n");
 
-	BUG_ON(max_reqs == 0);
+	if (max_reqs == 0)
+		goto out;
+
 	spin_lock_bh(&xprt->bc_pa_lock);
 	xprt_dec_alloc_count(xprt, max_reqs);
 	list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
@@ -202,6 +204,7 @@ void xprt_destroy_backchannel(struct rpc_xprt *xprt, unsigned int max_reqs)
 	}
 	spin_unlock_bh(&xprt->bc_pa_lock);
 
+out:
 	dprintk("RPC:        backchannel list empty= %s\n",
 		list_empty(&xprt->bc_pa_list) ? "true" : "false");
 }
@@ -255,7 +258,7 @@ void xprt_free_bc_request(struct rpc_rqst *req)
 	dprintk("RPC:       free backchannel req=%p\n", req);
 
 	smp_mb__before_clear_bit();
-	BUG_ON(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
+	WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
 	clear_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 	smp_mb__after_clear_bit();
 
diff --git a/net/sunrpc/bc_svc.c b/net/sunrpc/bc_svc.c
index 0b2eb388cbda..15c7a8a1c24f 100644
--- a/net/sunrpc/bc_svc.c
+++ b/net/sunrpc/bc_svc.c
@@ -53,7 +53,7 @@ int bc_send(struct rpc_rqst *req)
 	if (IS_ERR(task))
 		ret = PTR_ERR(task);
 	else {
-		BUG_ON(atomic_read(&task->tk_count) != 1);
+		WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
 		ret = task->tk_status;
 		rpc_put_task(task);
 	}
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index fc2f7aa4dca7..9afa4393c217 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -775,11 +775,11 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
 	if (rp->q.list.next == &cd->queue) {
 		spin_unlock(&queue_lock);
 		mutex_unlock(&inode->i_mutex);
-		BUG_ON(rp->offset);
+		WARN_ON_ONCE(rp->offset);
 		return 0;
 	}
 	rq = container_of(rp->q.list.next, struct cache_request, q.list);
-	BUG_ON(rq->q.reader);
+	WARN_ON_ONCE(rq->q.reader);
 	if (rp->offset == 0)
 		rq->readers++;
 	spin_unlock(&queue_lock);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index cdc7564b4512..822f020fa7f4 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -132,8 +132,10 @@ static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 	int error;
 
 	dir = rpc_d_lookup_sb(sb, dir_name);
-	if (dir == NULL)
+	if (dir == NULL) {
+		pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 		return dir;
+	}
 	for (;;) {
 		q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 		name[sizeof(name) - 1] = '\0';
@@ -192,7 +194,8 @@ static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 	case RPC_PIPEFS_MOUNT:
 		dentry = rpc_setup_pipedir_sb(sb, clnt,
 					      clnt->cl_program->pipe_dir_name);
-		BUG_ON(dentry == NULL);
+		if (!dentry)
+			return -ENOENT;
 		if (IS_ERR(dentry))
 			return PTR_ERR(dentry);
 		clnt->cl_dentry = dentry;
@@ -234,7 +237,7 @@ static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 	spin_lock(&sn->rpc_client_lock);
 	list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 		if (clnt->cl_program->pipe_dir_name == NULL)
-			break;
+			continue;
 		if (rpc_clnt_skip_event(clnt, event))
 			continue;
 		if (atomic_inc_not_zero(&clnt->cl_count) == 0)
@@ -607,6 +610,13 @@ EXPORT_SYMBOL_GPL(rpc_killall_tasks);
  */
 void rpc_shutdown_client(struct rpc_clnt *clnt)
 {
+	/*
+	 * To avoid deadlock, never call rpc_shutdown_client from a
+	 * workqueue context!
+	 */
+	WARN_ON_ONCE(current->flags & PF_WQ_WORKER);
+	might_sleep();
+
 	dprintk_rcu("RPC:       shutting down %s client for %s\n",
 			clnt->cl_protname,
 			rcu_dereference(clnt->cl_xprt)->servername);
@@ -693,21 +703,19 @@ struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 				      const struct rpc_program *program,
 				      u32 vers)
 {
+	struct rpc_create_args args = {
+		.program	= program,
+		.prognumber	= program->number,
+		.version	= vers,
+		.authflavor	= old->cl_auth->au_flavor,
+		.client_name	= old->cl_principal,
+	};
 	struct rpc_clnt *clnt;
-	const struct rpc_version *version;
 	int err;
 
-	BUG_ON(vers >= program->nrvers || !program->version[vers]);
-	version = program->version[vers];
-	clnt = rpc_clone_client(old);
+	clnt = __rpc_clone_client(&args, old);
 	if (IS_ERR(clnt))
 		goto out;
-	clnt->cl_procinfo = version->procs;
-	clnt->cl_maxproc  = version->nrprocs;
-	clnt->cl_protname = program->name;
-	clnt->cl_prog     = program->number;
-	clnt->cl_vers     = version->number;
-	clnt->cl_stats    = program->stats;
 	err = rpc_ping(clnt);
 	if (err != 0) {
 		rpc_shutdown_client(clnt);
@@ -832,7 +840,12 @@ int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flag
 	};
 	int status;
 
-	BUG_ON(flags & RPC_TASK_ASYNC);
+	WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
+	if (flags & RPC_TASK_ASYNC) {
+		rpc_release_calldata(task_setup_data.callback_ops,
+			task_setup_data.callback_data);
+		return -EINVAL;
+	}
 
 	task = rpc_run_task(&task_setup_data);
 	if (IS_ERR(task))
@@ -908,7 +921,7 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 
 	task->tk_action = call_bc_transmit;
 	atomic_inc(&task->tk_count);
-	BUG_ON(atomic_read(&task->tk_count) != 2);
+	WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 	rpc_execute(task);
 
 out:
@@ -1368,6 +1381,7 @@ call_refreshresult(struct rpc_task *task)
 		return;
 	case -ETIMEDOUT:
 		rpc_delay(task, 3*HZ);
+	case -EKEYEXPIRED:
 	case -EAGAIN:
 		status = -EACCES;
 		if (!task->tk_cred_retry)
@@ -1654,7 +1668,6 @@ call_transmit(struct rpc_task *task)
 	task->tk_action = call_transmit_status;
 	/* Encode here so that rpcsec_gss can use correct sequence number. */
 	if (rpc_task_need_encode(task)) {
-		BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
 		rpc_xdr_encode(task);
 		/* Did the encode result in an error condition? */
 		if (task->tk_status != 0) {
@@ -1738,7 +1751,6 @@ call_bc_transmit(struct rpc_task *task)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
 
-	BUG_ON(task->tk_status != 0);
 	task->tk_status = xprt_prepare_transmit(task);
 	if (task->tk_status == -EAGAIN) {
 		/*
@@ -1785,7 +1797,7 @@ call_bc_transmit(struct rpc_task *task)
 		 * We were unable to reply and will have to drop the
 		 * request.  The server should reconnect and retransmit.
 		 */
-		BUG_ON(task->tk_status == -EAGAIN);
+		WARN_ON_ONCE(task->tk_status == -EAGAIN);
 		printk(KERN_NOTICE "RPC: Could not send backchannel reply "
 			"error: %d\n", task->tk_status);
 		break;
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 80f5dd23417d..fd10981ea792 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -1093,7 +1093,7 @@ void rpc_put_sb_net(const struct net *net)
 {
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
-	BUG_ON(sn->pipefs_sb == NULL);
+	WARN_ON(sn->pipefs_sb == NULL);
 	mutex_unlock(&sn->pipefs_sb_lock);
 }
 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
@@ -1152,14 +1152,19 @@ static void rpc_kill_sb(struct super_block *sb)
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
 	mutex_lock(&sn->pipefs_sb_lock);
+	if (sn->pipefs_sb != sb) {
+		mutex_unlock(&sn->pipefs_sb_lock);
+		goto out;
+	}
 	sn->pipefs_sb = NULL;
 	mutex_unlock(&sn->pipefs_sb_lock);
-	put_net(net);
 	dprintk("RPC:       sending pipefs UMOUNT notification for net %p%s\n",
 		net, NET_NAME(net));
 	blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
 					   RPC_PIPEFS_UMOUNT,
 					   sb);
+	put_net(net);
+out:
 	kill_litter_super(sb);
 }
 
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index a70acae496e4..411f332de0b3 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -884,7 +884,10 @@ static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 	u32 len;
 
 	len = strlen(string);
-	BUG_ON(len > maxstrlen);
+	WARN_ON_ONCE(len > maxstrlen);
+	if (len > maxstrlen)
+		/* truncate and hope for the best */
+		len = maxstrlen;
 	p = xdr_reserve_space(xdr, 4 + len);
 	xdr_encode_opaque(p, string, len);
 }
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 6357fcb00c7e..d17a704aaf5f 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -98,6 +98,23 @@ __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
 	list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list);
 }
 
+static void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
+{
+	queue->priority = priority;
+}
+
+static void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
+{
+	queue->owner = pid;
+	queue->nr = RPC_BATCH_COUNT;
+}
+
+static void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
+{
+	rpc_set_waitqueue_priority(queue, queue->maxpriority);
+	rpc_set_waitqueue_owner(queue, 0);
+}
+
 /*
  * Add new request to a priority queue.
  */
@@ -109,9 +126,11 @@ static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue,
 	struct rpc_task *t;
 
 	INIT_LIST_HEAD(&task->u.tk_wait.links);
-	q = &queue->tasks[queue_priority];
 	if (unlikely(queue_priority > queue->maxpriority))
-		q = &queue->tasks[queue->maxpriority];
+		queue_priority = queue->maxpriority;
+	if (queue_priority > queue->priority)
+		rpc_set_waitqueue_priority(queue, queue_priority);
+	q = &queue->tasks[queue_priority];
 	list_for_each_entry(t, q, u.tk_wait.list) {
 		if (t->tk_owner == task->tk_owner) {
 			list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
@@ -133,7 +152,9 @@ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue,
 		struct rpc_task *task,
 		unsigned char queue_priority)
 {
-	BUG_ON (RPC_IS_QUEUED(task));
+	WARN_ON_ONCE(RPC_IS_QUEUED(task));
+	if (RPC_IS_QUEUED(task))
+		return;
 
 	if (RPC_IS_PRIORITY(queue))
 		__rpc_add_wait_queue_priority(queue, task, queue_priority);
@@ -178,24 +199,6 @@ static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_tas
 			task->tk_pid, queue, rpc_qname(queue));
 }
 
-static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
-{
-	queue->priority = priority;
-	queue->count = 1 << (priority * 2);
-}
-
-static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
-{
-	queue->owner = pid;
-	queue->nr = RPC_BATCH_COUNT;
-}
-
-static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
-{
-	rpc_set_waitqueue_priority(queue, queue->maxpriority);
-	rpc_set_waitqueue_owner(queue, 0);
-}
-
 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues)
 {
 	int i;
@@ -334,7 +337,7 @@ static void __rpc_sleep_on_priority(struct rpc_wait_queue *q,
 
 	__rpc_add_wait_queue(q, task, queue_priority);
 
-	BUG_ON(task->tk_callback != NULL);
+	WARN_ON_ONCE(task->tk_callback != NULL);
 	task->tk_callback = action;
 	__rpc_add_timer(q, task);
 }
@@ -343,7 +346,12 @@ void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
 				rpc_action action)
 {
 	/* We shouldn't ever put an inactive task to sleep */
-	BUG_ON(!RPC_IS_ACTIVATED(task));
+	WARN_ON_ONCE(!RPC_IS_ACTIVATED(task));
+	if (!RPC_IS_ACTIVATED(task)) {
+		task->tk_status = -EIO;
+		rpc_put_task_async(task);
+		return;
+	}
 
 	/*
 	 * Protect the queue operations.
@@ -358,7 +366,12 @@ void rpc_sleep_on_priority(struct rpc_wait_queue *q, struct rpc_task *task,
 		rpc_action action, int priority)
 {
 	/* We shouldn't ever put an inactive task to sleep */
-	BUG_ON(!RPC_IS_ACTIVATED(task));
+	WARN_ON_ONCE(!RPC_IS_ACTIVATED(task));
+	if (!RPC_IS_ACTIVATED(task)) {
+		task->tk_status = -EIO;
+		rpc_put_task_async(task);
+		return;
+	}
 
 	/*
 	 * Protect the queue operations.
@@ -367,6 +380,7 @@ void rpc_sleep_on_priority(struct rpc_wait_queue *q, struct rpc_task *task,
 	__rpc_sleep_on_priority(q, task, action, priority - RPC_PRIORITY_LOW);
 	spin_unlock_bh(&q->lock);
 }
+EXPORT_SYMBOL_GPL(rpc_sleep_on_priority);
 
 /**
  * __rpc_do_wake_up_task - wake up a single rpc_task
@@ -451,8 +465,7 @@ static struct rpc_task *__rpc_find_next_queued_priority(struct rpc_wait_queue *q
 		/*
 		 * Check if we need to switch queues.
 		 */
-		if (--queue->count)
-			goto new_owner;
+		goto new_owner;
 	}
 
 	/*
@@ -697,7 +710,9 @@ static void __rpc_execute(struct rpc_task *task)
 	dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
 			task->tk_pid, task->tk_flags);
 
-	BUG_ON(RPC_IS_QUEUED(task));
+	WARN_ON_ONCE(RPC_IS_QUEUED(task));
+	if (RPC_IS_QUEUED(task))
+		return;
 
 	for (;;) {
 		void (*do_action)(struct rpc_task *);
@@ -981,7 +996,7 @@ static void rpc_release_task(struct rpc_task *task)
 {
 	dprintk("RPC: %5u release task\n", task->tk_pid);
 
-	BUG_ON (RPC_IS_QUEUED(task));
+	WARN_ON_ONCE(RPC_IS_QUEUED(task));
 
 	rpc_release_resources_task(task);
 
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 3ee7461926d8..dfa4ba69ff45 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -324,7 +324,9 @@ svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
 	 * The caller checks for sv_nrpools > 1, which
 	 * implies that we've been initialized.
 	 */
-	BUG_ON(m->count == 0);
+	WARN_ON_ONCE(m->count == 0);
+	if (m->count == 0)
+		return;
 
 	switch (m->mode) {
 	case SVC_POOL_PERCPU:
@@ -585,7 +587,9 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
 				       * We assume one is at most one page
 				       */
 	arghi = 0;
-	BUG_ON(pages > RPCSVC_MAXPAGES);
+	WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
+	if (pages > RPCSVC_MAXPAGES)
+		pages = RPCSVC_MAXPAGES;
 	while (pages) {
 		struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
 		if (!p)
@@ -946,7 +950,9 @@ int svc_register(const struct svc_serv *serv, struct net *net,
 	unsigned int		i;
 	int			error = 0;
 
-	BUG_ON(proto == 0 && port == 0);
+	WARN_ON_ONCE(proto == 0 && port == 0);
+	if (proto == 0 && port == 0)
+		return -EINVAL;
 
 	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
 		for (i = 0; i < progp->pg_nvers; i++) {
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 194d865fae72..b8e47fac7315 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -218,7 +218,9 @@ static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
  */
 static void svc_xprt_received(struct svc_xprt *xprt)
 {
-	BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
+	WARN_ON_ONCE(!test_bit(XPT_BUSY, &xprt->xpt_flags));
+	if (!test_bit(XPT_BUSY, &xprt->xpt_flags))
+		return;
 	/* As soon as we clear busy, the xprt could be closed and
 	 * 'put', so we need a reference to call svc_xprt_enqueue with:
 	 */
@@ -577,7 +579,10 @@ int svc_alloc_arg(struct svc_rqst *rqstp)
 
 	/* now allocate needed pages.  If we get a failure, sleep briefly */
 	pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
-	BUG_ON(pages >= RPCSVC_MAXPAGES);
+	WARN_ON_ONCE(pages >= RPCSVC_MAXPAGES);
+	if (pages >= RPCSVC_MAXPAGES)
+		/* use as many pages as possible */
+		pages = RPCSVC_MAXPAGES - 1;
 	for (i = 0; i < pages ; i++)
 		while (rqstp->rq_pages[i] == NULL) {
 			struct page *p = alloc_page(GFP_KERNEL);
@@ -926,7 +931,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
 	spin_lock_bh(&serv->sv_lock);
 	if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
 		list_del_init(&xprt->xpt_list);
-	BUG_ON(!list_empty(&xprt->xpt_ready));
+	WARN_ON_ONCE(!list_empty(&xprt->xpt_ready));
 	if (test_bit(XPT_TEMP, &xprt->xpt_flags))
 		serv->sv_tmpcnt--;
 	spin_unlock_bh(&serv->sv_lock);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 03827cef1fa7..cc3020d16789 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -84,7 +84,11 @@ static struct lock_class_key svc_slock_key[2];
 static void svc_reclassify_socket(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
-	BUG_ON(sock_owned_by_user(sk));
+
+	WARN_ON_ONCE(sock_owned_by_user(sk));
+	if (sock_owned_by_user(sk))
+		return;
+
 	switch (sk->sk_family) {
 	case AF_INET:
 		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 08f50afd5f2a..56055632f151 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -318,7 +318,10 @@ xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
 
 	tail = buf->tail;
 	head = buf->head;
-	BUG_ON (len > head->iov_len);
+
+	WARN_ON_ONCE(len > head->iov_len);
+	if (len > head->iov_len)
+		len = head->iov_len;
 
 	/* Shift the tail first */
 	if (tail->iov_len != 0) {
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 75853cabf4c9..68b0a81c31d5 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1746,7 +1746,6 @@ static inline void xs_reclassify_socketu(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 
-	BUG_ON(sock_owned_by_user(sk));
 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
 }
@@ -1755,7 +1754,6 @@ static inline void xs_reclassify_socket4(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 
-	BUG_ON(sock_owned_by_user(sk));
 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
 }
@@ -1764,13 +1762,16 @@ static inline void xs_reclassify_socket6(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 
-	BUG_ON(sock_owned_by_user(sk));
 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
 }
 
 static inline void xs_reclassify_socket(int family, struct socket *sock)
 {
+	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
+	if (sock_owned_by_user(sock->sk))
+		return;
+
 	switch (family) {
 	case AF_LOCAL:
 		xs_reclassify_socketu(sock);
@@ -1901,6 +1902,10 @@ static void xs_local_setup_socket(struct work_struct *work)
 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
 		break;
+	case -ECONNREFUSED:
+		dprintk("RPC:       xprt %p: connection refused for %s\n",
+				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
+		break;
 	default:
 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
 				__func__, -status,
@@ -2329,9 +2334,11 @@ static void *bc_malloc(struct rpc_task *task, size_t size)
 	struct page *page;
 	struct rpc_buffer *buf;
 
-	BUG_ON(size > PAGE_SIZE - sizeof(struct rpc_buffer));
-	page = alloc_page(GFP_KERNEL);
+	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
+	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
+		return NULL;
 
+	page = alloc_page(GFP_KERNEL);
 	if (!page)
 		return NULL;
 
@@ -2393,7 +2400,6 @@ static int bc_send_request(struct rpc_task *task)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
 	struct svc_xprt	*xprt;
-	struct svc_sock         *svsk;
 	u32                     len;
 
 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
@@ -2401,7 +2407,6 @@ static int bc_send_request(struct rpc_task *task)
 	 * Get the server socket associated with this callback xprt
 	 */
 	xprt = req->rq_xprt->bc_xprt;
-	svsk = container_of(xprt, struct svc_sock, sk_xprt);
 
 	/*
 	 * Grab the mutex to serialize data as the connection is shared