SUNRPC: Add a convenient default for the hostname when calling rpc_create()

A couple of callers just use a stringified IP address for the rpc client's
hostname.  Move the logic for constructing this into rpc_create(), so it can
be shared.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 17 insertions, 15 deletions

diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index 878d7a5cb6d4..2892ec843066 100644
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -28,8 +28,7 @@
 #define MOUNT_UMNT              3
  */
 
-static struct rpc_clnt *        mnt_create(char *, struct sockaddr_in *,
-                                                                int, int);
+static struct rpc_clnt *        mnt_create(struct sockaddr_in *, int, int);
 static struct rpc_program       mnt_program;
 
 struct mnt_fhstatus {
@@ -52,14 +51,12 @@ nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
                 .rpc_argp       = path,
                 .rpc_resp       = &result,
         };
-        char                    hostname[32];
         int                     status;
 
         dprintk("NFS:      nfs_mount(%08x:%s)\n",
                         (unsigned)ntohl(addr->sin_addr.s_addr), path);
 
-        sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr->sin_addr.s_addr));
-        mnt_clnt = mnt_create(hostname, addr, version, protocol);
+        mnt_clnt = mnt_create(addr, version, protocol);
         if (IS_ERR(mnt_clnt))
                 return PTR_ERR(mnt_clnt);
 
@@ -73,15 +70,13 @@ nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
         return status < 0? status : (result.status? -EACCES : 0);
 }
 
-static struct rpc_clnt *
-mnt_create(char *hostname, struct sockaddr_in *srvaddr, int version,
-                int protocol)
+static struct rpc_clnt *mnt_create(struct sockaddr_in *srvaddr, int version,
+                                   int protocol)
 {
         struct rpc_create_args args = {
                 .protocol       = protocol,
                 .address        = (struct sockaddr *)srvaddr,
                 .addrsize       = sizeof(*srvaddr),
-                .servername     = hostname,
                 .program        = &mnt_program,
                 .version        = version,
                 .authflavor     = RPC_AUTH_UNIX,
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 6b1b487db1ec..5443c52b57aa 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -394,7 +394,6 @@ nfsd4_probe_callback(struct nfs4_client *clp)
                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
                 .rpc_argp       = clp,
         };
-        char clientname[16];
         int status;
 
         if (atomic_read(&cb->cb_set))
@@ -417,11 +416,6 @@ nfsd4_probe_callback(struct nfs4_client *clp)
         memset(program->stats, 0, sizeof(cb->cb_stat));
         program->stats->program = program;
 
-        /* Just here to make some printk's more useful: */
-        snprintf(clientname, sizeof(clientname),
-                "%u.%u.%u.%u", NIPQUAD(addr.sin_addr));
-        args.servername = clientname;
-
         /* Create RPC client */
         cb->cb_client = rpc_create(&args);
         if (IS_ERR(cb->cb_client)) {
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index e1553cf2a68f..0d9b5275fac3 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -234,6 +234,7 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 {
         struct rpc_xprt *xprt;
         struct rpc_clnt *clnt;
+        char servername[20];
 
         xprt = xprt_create_transport(args->protocol, args->address,
                                         args->addrsize, args->timeout);
@@ -241,6 +242,18 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
                 return (struct rpc_clnt *)xprt;
 
         /*
+         * If the caller chooses not to specify a hostname, whip
+         * up a string representation of the passed-in address.
+         */
+        if (args->servername == NULL) {
+                struct sockaddr_in *addr =
+                                        (struct sockaddr_in *) &args->address;
+                snprintf(servername, sizeof(servername), NIPQUAD_FMT,
+                        NIPQUAD(addr->sin_addr.s_addr));
+                args->servername = servername;
+        }
+
+        /*
          * By default, kernel RPC client connects from a reserved port.
          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
          * but it is always enabled for rpciod, which handles the connect