NFS: Extend the -overs= mount option to allow 4.x minorversions

Allow the user to mount an NFSv4.0 or NFSv4.1 partition using a
standard syntax of '-overs=4.0', or '-overs=4.1' rather than the
more cumbersome '-overs=4,minorversion=1'.

See also the earlier patch by Dros Adamson, which added the
Linux-specific syntax '-ov4.0', '-ov4.1'.

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

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 8154acc..ab58bb9 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -98,10 +98,10 @@ enum {
        Opt_namelen,
        Opt_mountport,
        Opt_mountvers,
-       Opt_nfsvers,
        Opt_minorversion,
 
        /* Mount options that take string arguments */
+       Opt_nfsvers,
        Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
        Opt_addr, Opt_mountaddr, Opt_clientaddr,
        Opt_lookupcache,
@@ -166,9 +166,10 @@ static const match_table_t nfs_mount_option_tokens = {
        { Opt_namelen, "namlen=%s" },
        { Opt_mountport, "mountport=%s" },
        { Opt_mountvers, "mountvers=%s" },
+       { Opt_minorversion, "minorversion=%s" },
+
        { Opt_nfsvers, "nfsvers=%s" },
        { Opt_nfsvers, "vers=%s" },
-       { Opt_minorversion, "minorversion=%s" },
 
        { Opt_sec, "sec=%s" },
        { Opt_proto, "proto=%s" },
@@ -262,6 +263,22 @@ static match_table_t nfs_local_lock_tokens = {
        { Opt_local_lock_err, NULL }
 };
 
+enum {
+       Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
+       Opt_vers_4_1,
+
+       Opt_vers_err
+};
+
+static match_table_t nfs_vers_tokens = {
+       { Opt_vers_2, "2" },
+       { Opt_vers_3, "3" },
+       { Opt_vers_4, "4" },
+       { Opt_vers_4_0, "4.0" },
+       { Opt_vers_4_1, "4.1" },
+
+       { Opt_vers_err, NULL }
+};
 
 static void nfs_umount_begin(struct super_block *);
 static int  nfs_statfs(struct dentry *, struct kstatfs *);
@@ -1064,6 +1081,40 @@ static int nfs_parse_security_flavors(char *value,
        return 1;
 }
 
+static int nfs_parse_version_string(char *string,
+               struct nfs_parsed_mount_data *mnt,
+               substring_t *args)
+{
+       mnt->flags &= ~NFS_MOUNT_VER3;
+       switch (match_token(string, nfs_vers_tokens, args)) {
+       case Opt_vers_2:
+               mnt->version = 2;
+               break;
+       case Opt_vers_3:
+               mnt->flags |= NFS_MOUNT_VER3;
+               mnt->version = 3;
+               break;
+       case Opt_vers_4:
+               /* Backward compatibility option. In future,
+                * the mount program should always supply
+                * a NFSv4 minor version number.
+                */
+               mnt->version = 4;
+               break;
+       case Opt_vers_4_0:
+               mnt->version = 4;
+               mnt->minorversion = 0;
+               break;
+       case Opt_vers_4_1:
+               mnt->version = 4;
+               mnt->minorversion = 1;
+               break;
+       default:
+               return 0;
+       }
+       return 1;
+}
+
 static int nfs_get_option_str(substring_t args[], char **option)
 {
        kfree(*option);
@@ -1317,26 +1368,6 @@ static int nfs_parse_mount_options(char *raw,
                                goto out_invalid_value;
                        mnt->mount_server.version = option;
                        break;
-               case Opt_nfsvers:
-                       if (nfs_get_option_ul(args, &option))
-                               goto out_invalid_value;
-                       switch (option) {
-                       case NFS2_VERSION:
-                               mnt->flags &= ~NFS_MOUNT_VER3;
-                               mnt->version = 2;
-                               break;
-                       case NFS3_VERSION:
-                               mnt->flags |= NFS_MOUNT_VER3;
-                               mnt->version = 3;
-                               break;
-                       case NFS4_VERSION:
-                               mnt->flags &= ~NFS_MOUNT_VER3;
-                               mnt->version = 4;
-                               break;
-                       default:
-                               goto out_invalid_value;
-                       }
-                       break;
                case Opt_minorversion:
                        if (nfs_get_option_ul(args, &option))
                                goto out_invalid_value;
@@ -1348,6 +1379,15 @@ static int nfs_parse_mount_options(char *raw,
                /*
                 * options that take text values
                 */
+               case Opt_nfsvers:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       rc = nfs_parse_version_string(string, mnt, args);
+                       kfree(string);
+                       if (!rc)
+                               goto out_invalid_value;
+                       break;
                case Opt_sec:
                        string = match_strdup(args);
                        if (string == NULL)