3 files changed, 53 insertions, 0 deletions

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index d32b3aa6600d..113e1aa9b0e8 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -102,6 +102,12 @@ struct nfsd_net {
 	 */
 	struct timeval nfssvc_boot;
 
+	/*
+	 * Max number of connections this nfsd container will allow. Defaults
+	 * to '0' which is means that it bases this on the number of threads.
+	 */
+	unsigned int max_connections;
+
 	struct svc_serv *nfsd_serv;
 };
 
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 6a6f65cc8b34..4e042105fb6e 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -39,6 +39,7 @@ enum {
 	NFSD_Versions,
 	NFSD_Ports,
 	NFSD_MaxBlkSize,
+	NFSD_MaxConnections,
 	NFSD_SupportedEnctypes,
 	/*
 	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
@@ -62,6 +63,7 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
 static ssize_t write_versions(struct file *file, char *buf, size_t size);
 static ssize_t write_ports(struct file *file, char *buf, size_t size);
 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
+static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
 #ifdef CONFIG_NFSD_V4
 static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
 static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
@@ -77,6 +79,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 	[NFSD_Versions] = write_versions,
 	[NFSD_Ports] = write_ports,
 	[NFSD_MaxBlkSize] = write_maxblksize,
+	[NFSD_MaxConnections] = write_maxconn,
 #ifdef CONFIG_NFSD_V4
 	[NFSD_Leasetime] = write_leasetime,
 	[NFSD_Gracetime] = write_gracetime,
@@ -886,6 +889,44 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
 							nfsd_max_blksize);
 }
 
+/**
+ * write_maxconn - Set or report the current max number of connections
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * OR
+ *
+ * Input:
+ * 			buf:		C string containing an unsigned
+ * 					integer value representing the new
+ * 					number of max connections
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C string
+ *			containing numeric value of max_connections setting
+ *			for this net namespace;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	struct net *net = file->f_dentry->d_sb->s_fs_info;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	unsigned int maxconn = nn->max_connections;
+
+	if (size > 0) {
+		int rv = get_uint(&mesg, &maxconn);
+
+		if (rv)
+			return rv;
+		nn->max_connections = maxconn;
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
+}
+
 #ifdef CONFIG_NFSD_V4
 static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
 				  time_t *time, struct nfsd_net *nn)
@@ -1061,6 +1102,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
 		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
+		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
 #if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
 		[NFSD_SupportedEnctypes] = {"supported_krb5_enctypes", &supported_enctypes_ops, S_IRUGO},
 #endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 209474174fe4..5d026dca00ca 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -405,6 +405,7 @@ int nfsd_create_serv(struct net *net)
 	if (nn->nfsd_serv == NULL)
 		return -ENOMEM;
 
+	nn->nfsd_serv->sv_maxconn = nn->max_connections;
 	error = svc_bind(nn->nfsd_serv, net);
 	if (error < 0) {
 		svc_destroy(nn->nfsd_serv);
@@ -563,6 +564,7 @@ nfsd(void *vrqstp)
 	struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
 	struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
 	struct net *net = perm_sock->xpt_net;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 	int err;
 
 	/* Lock module and set up kernel thread */
@@ -596,6 +598,9 @@ nfsd(void *vrqstp)
 	 * The main request loop
 	 */
 	for (;;) {
+		/* Update sv_maxconn if it has changed */
+		rqstp->rq_server->sv_maxconn = nn->max_connections;
+
 		/*
 		 * Find a socket with data available and call its
 		 * recvfrom routine.