NFS: Remake nfsroot_mount as a permanent part of NFS client

In preparation for supporting NFSv2 and NFSv3 mount option handling in the
kernel NFS client, convert mount_clnt.c to be a permanent part of the NFS
client, instead of built only when CONFIG_ROOT_NFS is enabled.

In addition, we also replace the "struct sockaddr_in *" argument with
something more generic, to help support IPv6 at some later point.

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

3 files changed, 32 insertions, 30 deletions

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index f4580b44eef4..b55cb236cf74 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -6,8 +6,8 @@ obj-$(CONFIG_NFS_FS) += nfs.o
 
 nfs-y                   := client.o dir.o file.o getroot.o inode.o super.o nfs2xdr.o \
                            pagelist.o proc.o read.o symlink.o unlink.o \
-                           write.o namespace.o
-nfs-$(CONFIG_ROOT_NFS)  += nfsroot.o mount_clnt.o      
+                           write.o namespace.o mount_clnt.o
+nfs-$(CONFIG_ROOT_NFS)  += nfsroot.o
 nfs-$(CONFIG_NFS_V3)    += nfs3proc.o nfs3xdr.o
 nfs-$(CONFIG_NFS_V3_ACL)        += nfs3acl.o
 nfs-$(CONFIG_NFS_V4)    += nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o \
diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index 2892ec843066..ee4899d96629 100644
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -18,7 +18,7 @@
 #include <linux/nfs_fs.h>
 
 #ifdef RPC_DEBUG
-# define NFSDBG_FACILITY        NFSDBG_ROOT
+# define NFSDBG_FACILITY        NFSDBG_MOUNT
 #endif
 
 /*
@@ -28,7 +28,6 @@
 #define MOUNT_UMNT              3
  */
 
-static struct rpc_clnt *        mnt_create(struct sockaddr_in *, int, int);
 static struct rpc_program       mnt_program;
 
 struct mnt_fhstatus {
@@ -36,14 +35,21 @@ struct mnt_fhstatus {
         struct nfs_fh *         fh;
 };
 
-/*
- * Obtain an NFS file handle for the given host and path
+/**
+ * nfs_mount - Obtain an NFS file handle for the given host and path
+ * @addr: pointer to server's address
+ * @len: size of server's address
+ * @hostname: name of server host, or NULL
+ * @path: pointer to string containing export path to mount
+ * @version: mount version to use for this request
+ * @protocol: transport protocol to use for thie request
+ * @fh: pointer to location to place returned file handle
+ *
+ * Uses default timeout parameters specified by underlying transport.
  */
-int
-nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
-                int version, int protocol)
+int nfs_mount(struct sockaddr *addr, size_t len, char *hostname, char *path,
+              int version, int protocol, struct nfs_fh *fh)
 {
-        struct rpc_clnt         *mnt_clnt;
         struct mnt_fhstatus     result = {
                 .fh             = fh
         };
@@ -51,12 +57,23 @@ nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
                 .rpc_argp       = path,
                 .rpc_resp       = &result,
         };
+        struct rpc_create_args args = {
+                .protocol       = protocol,
+                .address        = addr,
+                .addrsize       = len,
+                .servername     = hostname,
+                .program        = &mnt_program,
+                .version        = version,
+                .authflavor     = RPC_AUTH_UNIX,
+                .flags          = RPC_CLNT_CREATE_INTR,
+        };
+        struct rpc_clnt         *mnt_clnt;
         int                     status;
 
-        dprintk("NFS:      nfs_mount(%08x:%s)\n",
-                        (unsigned)ntohl(addr->sin_addr.s_addr), path);
+        dprintk("NFS: sending MNT request for %s:%s\n",
+                (hostname ? hostname : "server"), path);
 
-        mnt_clnt = mnt_create(addr, version, protocol);
+        mnt_clnt = rpc_create(&args);
         if (IS_ERR(mnt_clnt))
                 return PTR_ERR(mnt_clnt);
 
@@ -70,22 +87,6 @@ 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(struct sockaddr_in *srvaddr, int version,
-                                   int protocol)
-{
-        struct rpc_create_args args = {
-                .protocol       = protocol,
-                .address        = (struct sockaddr *)srvaddr,
-                .addrsize       = sizeof(*srvaddr),
-                .program        = &mnt_program,
-                .version        = version,
-                .authflavor     = RPC_AUTH_UNIX,
-                .flags          = RPC_CLNT_CREATE_INTR,
-        };
-
-        return rpc_create(&args);
-}
-
 /*
  * XDR encode/decode functions for MOUNT
  */
diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
index f0db4703b1c9..3490322d1145 100644
--- a/fs/nfs/nfsroot.c
+++ b/fs/nfs/nfsroot.c
@@ -496,7 +496,8 @@ static int __init root_nfs_get_handle(void)
                                         NFS_MNT3_VERSION : NFS_MNT_VERSION;
 
         set_sockaddr(&sin, servaddr, htons(mount_port));
-        status = nfsroot_mount(&sin, nfs_path, &fh, version, protocol);
+        status = nfs_mount((struct sockaddr *) &sin, sizeof(sin), NULL,
+                           nfs_path, version, protocol, &fh);
         if (status < 0)
                 printk(KERN_ERR "Root-NFS: Server returned error %d "
                                 "while mounting %s\n", status, nfs_path);