Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
[sfrench/cifs-2.6.git] / fs / nfs / super.c
index ed3ec4477a0fedf61c5946a8baf791c66c576caa..b878528b64c1a9d0aed22fd19b20339bc1644b22 100644 (file)
@@ -45,6 +45,7 @@
 #include <linux/inet.h>
 #include <linux/nfs_xdr.h>
 #include <linux/magic.h>
+#include <linux/parser.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
 #define NFSDBG_FACILITY                NFSDBG_VFS
 
+
+struct nfs_parsed_mount_data {
+       int                     flags;
+       int                     rsize, wsize;
+       int                     timeo, retrans;
+       int                     acregmin, acregmax,
+                               acdirmin, acdirmax;
+       int                     namlen;
+       unsigned int            bsize;
+       unsigned int            auth_flavor_len;
+       rpc_authflavor_t        auth_flavors[1];
+       char                    *client_address;
+
+       struct {
+               struct sockaddr_in      address;
+               unsigned int            program;
+               unsigned int            version;
+               unsigned short          port;
+               int                     protocol;
+       } mount_server;
+
+       struct {
+               struct sockaddr_in      address;
+               char                    *hostname;
+               char                    *export_path;
+               unsigned int            program;
+               int                     protocol;
+       } nfs_server;
+};
+
+enum {
+       /* Mount options that take no arguments */
+       Opt_soft, Opt_hard,
+       Opt_intr, Opt_nointr,
+       Opt_posix, Opt_noposix,
+       Opt_cto, Opt_nocto,
+       Opt_ac, Opt_noac,
+       Opt_lock, Opt_nolock,
+       Opt_v2, Opt_v3,
+       Opt_udp, Opt_tcp,
+       Opt_acl, Opt_noacl,
+       Opt_rdirplus, Opt_nordirplus,
+       Opt_sharecache, Opt_nosharecache,
+
+       /* Mount options that take integer arguments */
+       Opt_port,
+       Opt_rsize, Opt_wsize, Opt_bsize,
+       Opt_timeo, Opt_retrans,
+       Opt_acregmin, Opt_acregmax,
+       Opt_acdirmin, Opt_acdirmax,
+       Opt_actimeo,
+       Opt_namelen,
+       Opt_mountport,
+       Opt_mountprog, Opt_mountvers,
+       Opt_nfsprog, Opt_nfsvers,
+
+       /* Mount options that take string arguments */
+       Opt_sec, Opt_proto, Opt_mountproto,
+       Opt_addr, Opt_mounthost, Opt_clientaddr,
+
+       /* Mount options that are ignored */
+       Opt_userspace, Opt_deprecated,
+
+       Opt_err
+};
+
+static match_table_t nfs_mount_option_tokens = {
+       { Opt_userspace, "bg" },
+       { Opt_userspace, "fg" },
+       { Opt_soft, "soft" },
+       { Opt_hard, "hard" },
+       { Opt_intr, "intr" },
+       { Opt_nointr, "nointr" },
+       { Opt_posix, "posix" },
+       { Opt_noposix, "noposix" },
+       { Opt_cto, "cto" },
+       { Opt_nocto, "nocto" },
+       { Opt_ac, "ac" },
+       { Opt_noac, "noac" },
+       { Opt_lock, "lock" },
+       { Opt_nolock, "nolock" },
+       { Opt_v2, "v2" },
+       { Opt_v3, "v3" },
+       { Opt_udp, "udp" },
+       { Opt_tcp, "tcp" },
+       { Opt_acl, "acl" },
+       { Opt_noacl, "noacl" },
+       { Opt_rdirplus, "rdirplus" },
+       { Opt_nordirplus, "nordirplus" },
+       { Opt_sharecache, "sharecache" },
+       { Opt_nosharecache, "nosharecache" },
+
+       { Opt_port, "port=%u" },
+       { Opt_rsize, "rsize=%u" },
+       { Opt_wsize, "wsize=%u" },
+       { Opt_bsize, "bsize=%u" },
+       { Opt_timeo, "timeo=%u" },
+       { Opt_retrans, "retrans=%u" },
+       { Opt_acregmin, "acregmin=%u" },
+       { Opt_acregmax, "acregmax=%u" },
+       { Opt_acdirmin, "acdirmin=%u" },
+       { Opt_acdirmax, "acdirmax=%u" },
+       { Opt_actimeo, "actimeo=%u" },
+       { Opt_userspace, "retry=%u" },
+       { Opt_namelen, "namlen=%u" },
+       { Opt_mountport, "mountport=%u" },
+       { Opt_mountprog, "mountprog=%u" },
+       { Opt_mountvers, "mountvers=%u" },
+       { Opt_nfsprog, "nfsprog=%u" },
+       { Opt_nfsvers, "nfsvers=%u" },
+       { Opt_nfsvers, "vers=%u" },
+
+       { Opt_sec, "sec=%s" },
+       { Opt_proto, "proto=%s" },
+       { Opt_mountproto, "mountproto=%s" },
+       { Opt_addr, "addr=%s" },
+       { Opt_clientaddr, "clientaddr=%s" },
+       { Opt_mounthost, "mounthost=%s" },
+
+       { Opt_err, NULL }
+};
+
+enum {
+       Opt_xprt_udp, Opt_xprt_tcp,
+
+       Opt_xprt_err
+};
+
+static match_table_t nfs_xprt_protocol_tokens = {
+       { Opt_xprt_udp, "udp" },
+       { Opt_xprt_tcp, "tcp" },
+
+       { Opt_xprt_err, NULL }
+};
+
+enum {
+       Opt_sec_none, Opt_sec_sys,
+       Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
+       Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
+       Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
+
+       Opt_sec_err
+};
+
+static match_table_t nfs_secflavor_tokens = {
+       { Opt_sec_none, "none" },
+       { Opt_sec_none, "null" },
+       { Opt_sec_sys, "sys" },
+
+       { Opt_sec_krb5, "krb5" },
+       { Opt_sec_krb5i, "krb5i" },
+       { Opt_sec_krb5p, "krb5p" },
+
+       { Opt_sec_lkey, "lkey" },
+       { Opt_sec_lkeyi, "lkeyi" },
+       { Opt_sec_lkeyp, "lkeyp" },
+
+       { Opt_sec_err, NULL }
+};
+
+
 static void nfs_umount_begin(struct vfsmount *, int);
 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
@@ -138,7 +300,10 @@ static const struct super_operations nfs4_sops = {
 };
 #endif
 
-static struct shrinker *acl_shrinker;
+static struct shrinker acl_shrinker = {
+       .shrink         = nfs_access_cache_shrinker,
+       .seeks          = DEFAULT_SEEKS,
+};
 
 /*
  * Register the NFS filesystems
@@ -159,7 +324,7 @@ int __init register_nfs_fs(void)
        if (ret < 0)
                goto error_2;
 #endif
-       acl_shrinker = set_shrinker(DEFAULT_SEEKS, nfs_access_cache_shrinker);
+       register_shrinker(&acl_shrinker);
        return 0;
 
 #ifdef CONFIG_NFS_V4
@@ -177,12 +342,11 @@ error_0:
  */
 void __exit unregister_nfs_fs(void)
 {
-       if (acl_shrinker != NULL)
-               remove_shrinker(acl_shrinker);
+       unregister_shrinker(&acl_shrinker);
 #ifdef CONFIG_NFS_V4
        unregister_filesystem(&nfs4_fs_type);
-       nfs_unregister_sysctl();
 #endif
+       nfs_unregister_sysctl();
        unregister_filesystem(&nfs_fs_type);
 }
 
@@ -291,6 +455,7 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
                { NFS_MOUNT_NONLM, ",nolock", "" },
                { NFS_MOUNT_NOACL, ",noacl", "" },
                { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
+               { NFS_MOUNT_UNSHARED, ",nosharecache", ""},
                { 0, NULL, NULL }
        };
        const struct proc_nfs_info *nfs_infop;
@@ -463,13 +628,463 @@ static int nfs_verify_server_address(struct sockaddr *addr)
        return 0;
 }
 
+/*
+ * Error-check and convert a string of mount options from user space into
+ * a data structure
+ */
+static int nfs_parse_mount_options(char *raw,
+                                  struct nfs_parsed_mount_data *mnt)
+{
+       char *p, *string;
+
+       if (!raw) {
+               dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
+               return 1;
+       }
+       dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
+
+       while ((p = strsep(&raw, ",")) != NULL) {
+               substring_t args[MAX_OPT_ARGS];
+               int option, token;
+
+               if (!*p)
+                       continue;
+
+               dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
+
+               token = match_token(p, nfs_mount_option_tokens, args);
+               switch (token) {
+               case Opt_soft:
+                       mnt->flags |= NFS_MOUNT_SOFT;
+                       break;
+               case Opt_hard:
+                       mnt->flags &= ~NFS_MOUNT_SOFT;
+                       break;
+               case Opt_intr:
+                       mnt->flags |= NFS_MOUNT_INTR;
+                       break;
+               case Opt_nointr:
+                       mnt->flags &= ~NFS_MOUNT_INTR;
+                       break;
+               case Opt_posix:
+                       mnt->flags |= NFS_MOUNT_POSIX;
+                       break;
+               case Opt_noposix:
+                       mnt->flags &= ~NFS_MOUNT_POSIX;
+                       break;
+               case Opt_cto:
+                       mnt->flags &= ~NFS_MOUNT_NOCTO;
+                       break;
+               case Opt_nocto:
+                       mnt->flags |= NFS_MOUNT_NOCTO;
+                       break;
+               case Opt_ac:
+                       mnt->flags &= ~NFS_MOUNT_NOAC;
+                       break;
+               case Opt_noac:
+                       mnt->flags |= NFS_MOUNT_NOAC;
+                       break;
+               case Opt_lock:
+                       mnt->flags &= ~NFS_MOUNT_NONLM;
+                       break;
+               case Opt_nolock:
+                       mnt->flags |= NFS_MOUNT_NONLM;
+                       break;
+               case Opt_v2:
+                       mnt->flags &= ~NFS_MOUNT_VER3;
+                       break;
+               case Opt_v3:
+                       mnt->flags |= NFS_MOUNT_VER3;
+                       break;
+               case Opt_udp:
+                       mnt->flags &= ~NFS_MOUNT_TCP;
+                       mnt->nfs_server.protocol = IPPROTO_UDP;
+                       mnt->timeo = 7;
+                       mnt->retrans = 5;
+                       break;
+               case Opt_tcp:
+                       mnt->flags |= NFS_MOUNT_TCP;
+                       mnt->nfs_server.protocol = IPPROTO_TCP;
+                       mnt->timeo = 600;
+                       mnt->retrans = 2;
+                       break;
+               case Opt_acl:
+                       mnt->flags &= ~NFS_MOUNT_NOACL;
+                       break;
+               case Opt_noacl:
+                       mnt->flags |= NFS_MOUNT_NOACL;
+                       break;
+               case Opt_rdirplus:
+                       mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
+                       break;
+               case Opt_nordirplus:
+                       mnt->flags |= NFS_MOUNT_NORDIRPLUS;
+                       break;
+               case Opt_sharecache:
+                       mnt->flags &= ~NFS_MOUNT_UNSHARED;
+                       break;
+               case Opt_nosharecache:
+                       mnt->flags |= NFS_MOUNT_UNSHARED;
+                       break;
+
+               case Opt_port:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0 || option > 65535)
+                               return 0;
+                       mnt->nfs_server.address.sin_port = htons(option);
+                       break;
+               case Opt_rsize:
+                       if (match_int(args, &mnt->rsize))
+                               return 0;
+                       break;
+               case Opt_wsize:
+                       if (match_int(args, &mnt->wsize))
+                               return 0;
+                       break;
+               case Opt_bsize:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0)
+                               return 0;
+                       mnt->bsize = option;
+                       break;
+               case Opt_timeo:
+                       if (match_int(args, &mnt->timeo))
+                               return 0;
+                       break;
+               case Opt_retrans:
+                       if (match_int(args, &mnt->retrans))
+                               return 0;
+                       break;
+               case Opt_acregmin:
+                       if (match_int(args, &mnt->acregmin))
+                               return 0;
+                       break;
+               case Opt_acregmax:
+                       if (match_int(args, &mnt->acregmax))
+                               return 0;
+                       break;
+               case Opt_acdirmin:
+                       if (match_int(args, &mnt->acdirmin))
+                               return 0;
+                       break;
+               case Opt_acdirmax:
+                       if (match_int(args, &mnt->acdirmax))
+                               return 0;
+                       break;
+               case Opt_actimeo:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0)
+                               return 0;
+                       mnt->acregmin =
+                       mnt->acregmax =
+                       mnt->acdirmin =
+                       mnt->acdirmax = option;
+                       break;
+               case Opt_namelen:
+                       if (match_int(args, &mnt->namlen))
+                               return 0;
+                       break;
+               case Opt_mountport:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0 || option > 65535)
+                               return 0;
+                       mnt->mount_server.port = option;
+                       break;
+               case Opt_mountprog:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0)
+                               return 0;
+                       mnt->mount_server.program = option;
+                       break;
+               case Opt_mountvers:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0)
+                               return 0;
+                       mnt->mount_server.version = option;
+                       break;
+               case Opt_nfsprog:
+                       if (match_int(args, &option))
+                               return 0;
+                       if (option < 0)
+                               return 0;
+                       mnt->nfs_server.program = option;
+                       break;
+               case Opt_nfsvers:
+                       if (match_int(args, &option))
+                               return 0;
+                       switch (option) {
+                       case 2:
+                               mnt->flags &= ~NFS_MOUNT_VER3;
+                               break;
+                       case 3:
+                               mnt->flags |= NFS_MOUNT_VER3;
+                               break;
+                       default:
+                               goto out_unrec_vers;
+                       }
+                       break;
+
+               case Opt_sec:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       token = match_token(string, nfs_secflavor_tokens, args);
+                       kfree(string);
+
+                       /*
+                        * The flags setting is for v2/v3.  The flavor_len
+                        * setting is for v4.  v2/v3 also need to know the
+                        * difference between NULL and UNIX.
+                        */
+                       switch (token) {
+                       case Opt_sec_none:
+                               mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 0;
+                               mnt->auth_flavors[0] = RPC_AUTH_NULL;
+                               break;
+                       case Opt_sec_sys:
+                               mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 0;
+                               mnt->auth_flavors[0] = RPC_AUTH_UNIX;
+                               break;
+                       case Opt_sec_krb5:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
+                               break;
+                       case Opt_sec_krb5i:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
+                               break;
+                       case Opt_sec_krb5p:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
+                               break;
+                       case Opt_sec_lkey:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
+                               break;
+                       case Opt_sec_lkeyi:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
+                               break;
+                       case Opt_sec_lkeyp:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
+                               break;
+                       case Opt_sec_spkm:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
+                               break;
+                       case Opt_sec_spkmi:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
+                               break;
+                       case Opt_sec_spkmp:
+                               mnt->flags |= NFS_MOUNT_SECFLAVOUR;
+                               mnt->auth_flavor_len = 1;
+                               mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
+                               break;
+                       default:
+                               goto out_unrec_sec;
+                       }
+                       break;
+               case Opt_proto:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       token = match_token(string,
+                                           nfs_xprt_protocol_tokens, args);
+                       kfree(string);
+
+                       switch (token) {
+                       case Opt_xprt_udp:
+                               mnt->flags &= ~NFS_MOUNT_TCP;
+                               mnt->nfs_server.protocol = IPPROTO_UDP;
+                               mnt->timeo = 7;
+                               mnt->retrans = 5;
+                               break;
+                       case Opt_xprt_tcp:
+                               mnt->flags |= NFS_MOUNT_TCP;
+                               mnt->nfs_server.protocol = IPPROTO_TCP;
+                               mnt->timeo = 600;
+                               mnt->retrans = 2;
+                               break;
+                       default:
+                               goto out_unrec_xprt;
+                       }
+                       break;
+               case Opt_mountproto:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       token = match_token(string,
+                                           nfs_xprt_protocol_tokens, args);
+                       kfree(string);
+
+                       switch (token) {
+                       case Opt_xprt_udp:
+                               mnt->mount_server.protocol = IPPROTO_UDP;
+                               break;
+                       case Opt_xprt_tcp:
+                               mnt->mount_server.protocol = IPPROTO_TCP;
+                               break;
+                       default:
+                               goto out_unrec_xprt;
+                       }
+                       break;
+               case Opt_addr:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       mnt->nfs_server.address.sin_family = AF_INET;
+                       mnt->nfs_server.address.sin_addr.s_addr =
+                                                       in_aton(string);
+                       kfree(string);
+                       break;
+               case Opt_clientaddr:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       mnt->client_address = string;
+                       break;
+               case Opt_mounthost:
+                       string = match_strdup(args);
+                       if (string == NULL)
+                               goto out_nomem;
+                       mnt->mount_server.address.sin_family = AF_INET;
+                       mnt->mount_server.address.sin_addr.s_addr =
+                                                       in_aton(string);
+                       kfree(string);
+                       break;
+
+               case Opt_userspace:
+               case Opt_deprecated:
+                       break;
+
+               default:
+                       goto out_unknown;
+               }
+       }
+
+       return 1;
+
+out_nomem:
+       printk(KERN_INFO "NFS: not enough memory to parse option\n");
+       return 0;
+
+out_unrec_vers:
+       printk(KERN_INFO "NFS: unrecognized NFS version number\n");
+       return 0;
+
+out_unrec_xprt:
+       printk(KERN_INFO "NFS: unrecognized transport protocol\n");
+       return 0;
+
+out_unrec_sec:
+       printk(KERN_INFO "NFS: unrecognized security flavor\n");
+       return 0;
+
+out_unknown:
+       printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
+       return 0;
+}
+
+/*
+ * Use the remote server's MOUNT service to request the NFS file handle
+ * corresponding to the provided path.
+ */
+static int nfs_try_mount(struct nfs_parsed_mount_data *args,
+                        struct nfs_fh *root_fh)
+{
+       struct sockaddr_in sin;
+       int status;
+
+       if (args->mount_server.version == 0) {
+               if (args->flags & NFS_MOUNT_VER3)
+                       args->mount_server.version = NFS_MNT3_VERSION;
+               else
+                       args->mount_server.version = NFS_MNT_VERSION;
+       }
+
+       /*
+        * Construct the mount server's address.
+        */
+       if (args->mount_server.address.sin_addr.s_addr != INADDR_ANY)
+               sin = args->mount_server.address;
+       else
+               sin = args->nfs_server.address;
+       if (args->mount_server.port == 0) {
+               status = rpcb_getport_sync(&sin,
+                                          args->mount_server.program,
+                                          args->mount_server.version,
+                                          args->mount_server.protocol);
+               if (status < 0)
+                       goto out_err;
+               sin.sin_port = htons(status);
+       } else
+               sin.sin_port = htons(args->mount_server.port);
+
+       /*
+        * Now ask the mount server to map our export path
+        * to a file handle.
+        */
+       status = nfs_mount((struct sockaddr *) &sin,
+                          sizeof(sin),
+                          args->nfs_server.hostname,
+                          args->nfs_server.export_path,
+                          args->mount_server.version,
+                          args->mount_server.protocol,
+                          root_fh);
+       if (status < 0)
+               goto out_err;
+
+       return status;
+
+out_err:
+       dfprintk(MOUNT, "NFS: unable to contact server on host "
+                NIPQUAD_FMT "\n", NIPQUAD(sin.sin_addr.s_addr));
+       return status;
+}
+
 /*
  * Validate the NFS2/NFS3 mount data
  * - fills in the mount root filehandle
+ *
+ * For option strings, user space handles the following behaviors:
+ *
+ * + DNS: mapping server host name to IP address ("addr=" option)
+ *
+ * + failure mode: how to behave if a mount request can't be handled
+ *   immediately ("fg/bg" option)
+ *
+ * + retry: how often to retry a mount request ("retry=" option)
+ *
+ * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
+ *   mountproto=tcp after mountproto=udp, and so on
+ *
+ * XXX: as far as I can tell, changing the NFS program number is not
+ *      supported in the NFS client.
  */
-static int nfs_validate_mount_data(struct nfs_mount_data *data,
-                                  struct nfs_fh *mntfh)
+static int nfs_validate_mount_data(struct nfs_mount_data **options,
+                                  struct nfs_fh *mntfh,
+                                  const char *dev_name)
 {
+       struct nfs_mount_data *data = *options;
+
        if (data == NULL)
                goto out_no_data;
 
@@ -502,8 +1117,78 @@ static int nfs_validate_mount_data(struct nfs_mount_data *data,
                        memset(mntfh->data + mntfh->size, 0,
                               sizeof(mntfh->data) - mntfh->size);
                break;
-       default:
-               goto out_bad_version;
+       default: {
+               unsigned int len;
+               char *c;
+               int status;
+               struct nfs_parsed_mount_data args = {
+                       .flags          = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP),
+                       .rsize          = NFS_MAX_FILE_IO_SIZE,
+                       .wsize          = NFS_MAX_FILE_IO_SIZE,
+                       .timeo          = 600,
+                       .retrans        = 2,
+                       .acregmin       = 3,
+                       .acregmax       = 60,
+                       .acdirmin       = 30,
+                       .acdirmax       = 60,
+                       .mount_server.protocol = IPPROTO_UDP,
+                       .mount_server.program = NFS_MNT_PROGRAM,
+                       .nfs_server.protocol = IPPROTO_TCP,
+                       .nfs_server.program = NFS_PROGRAM,
+               };
+
+               if (nfs_parse_mount_options((char *) *options, &args) == 0)
+                       return -EINVAL;
+
+               data = kzalloc(sizeof(*data), GFP_KERNEL);
+               if (data == NULL)
+                       return -ENOMEM;
+
+               /*
+                * NB: after this point, caller will free "data"
+                * if we return an error
+                */
+               *options = data;
+
+               c = strchr(dev_name, ':');
+               if (c == NULL)
+                       return -EINVAL;
+               len = c - dev_name;
+               if (len > sizeof(data->hostname))
+                       return -ENAMETOOLONG;
+               strncpy(data->hostname, dev_name, len);
+               args.nfs_server.hostname = data->hostname;
+
+               c++;
+               if (strlen(c) > NFS_MAXPATHLEN)
+                       return -ENAMETOOLONG;
+               args.nfs_server.export_path = c;
+
+               status = nfs_try_mount(&args, mntfh);
+               if (status)
+                       return status;
+
+               /*
+                * Translate to nfs_mount_data, which nfs_fill_super
+                * can deal with.
+                */
+               data->version           = 6;
+               data->flags             = args.flags;
+               data->rsize             = args.rsize;
+               data->wsize             = args.wsize;
+               data->timeo             = args.timeo;
+               data->retrans           = args.retrans;
+               data->acregmin          = args.acregmin;
+               data->acregmax          = args.acregmax;
+               data->acdirmin          = args.acdirmin;
+               data->acdirmax          = args.acdirmax;
+               data->addr              = args.nfs_server.address;
+               data->namlen            = args.namlen;
+               data->bsize             = args.bsize;
+               data->pseudoflavor      = args.auth_flavors[0];
+
+               break;
+               }
        }
 
        if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
@@ -532,11 +1217,6 @@ out_no_sec:
        dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
        return -EINVAL;
 
-out_bad_version:
-       dfprintk(MOUNT, "NFS: bad nfs_mount_data version %d\n",
-                data->version);
-       return -EINVAL;
-
 #ifndef CONFIG_NFS_V3
 out_v3_not_compiled:
        dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
@@ -623,11 +1303,51 @@ static void nfs_clone_super(struct super_block *sb,
        nfs_initialise_sb(sb);
 }
 
-static int nfs_set_super(struct super_block *s, void *_server)
+#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
+
+static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
 {
-       struct nfs_server *server = _server;
+       const struct nfs_server *a = s->s_fs_info;
+       const struct rpc_clnt *clnt_a = a->client;
+       const struct rpc_clnt *clnt_b = b->client;
+
+       if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
+               goto Ebusy;
+       if (a->nfs_client != b->nfs_client)
+               goto Ebusy;
+       if (a->flags != b->flags)
+               goto Ebusy;
+       if (a->wsize != b->wsize)
+               goto Ebusy;
+       if (a->rsize != b->rsize)
+               goto Ebusy;
+       if (a->acregmin != b->acregmin)
+               goto Ebusy;
+       if (a->acregmax != b->acregmax)
+               goto Ebusy;
+       if (a->acdirmin != b->acdirmin)
+               goto Ebusy;
+       if (a->acdirmax != b->acdirmax)
+               goto Ebusy;
+       if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
+               goto Ebusy;
+       return 1;
+Ebusy:
+       return 0;
+}
+
+struct nfs_sb_mountdata {
+       struct nfs_server *server;
+       int mntflags;
+};
+
+static int nfs_set_super(struct super_block *s, void *data)
+{
+       struct nfs_sb_mountdata *sb_mntdata = data;
+       struct nfs_server *server = sb_mntdata->server;
        int ret;
 
+       s->s_flags = sb_mntdata->mntflags;
        s->s_fs_info = server;
        ret = set_anon_super(s, server);
        if (ret == 0)
@@ -637,13 +1357,20 @@ static int nfs_set_super(struct super_block *s, void *_server)
 
 static int nfs_compare_super(struct super_block *sb, void *data)
 {
-       struct nfs_server *server = data, *old = NFS_SB(sb);
+       struct nfs_sb_mountdata *sb_mntdata = data;
+       struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
+       int mntflags = sb_mntdata->mntflags;
 
-       if (old->nfs_client != server->nfs_client)
+       if (memcmp(&old->nfs_client->cl_addr,
+                               &server->nfs_client->cl_addr,
+                               sizeof(old->nfs_client->cl_addr)) != 0)
+               return 0;
+       /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
+       if (old->flags & NFS_MOUNT_UNSHARED)
                return 0;
        if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
                return 0;
-       return 1;
+       return nfs_compare_mount_options(sb, server, mntflags);
 }
 
 static int nfs_get_sb(struct file_system_type *fs_type,
@@ -654,10 +1381,14 @@ static int nfs_get_sb(struct file_system_type *fs_type,
        struct nfs_fh mntfh;
        struct nfs_mount_data *data = raw_data;
        struct dentry *mntroot;
+       int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+       struct nfs_sb_mountdata sb_mntdata = {
+               .mntflags = flags,
+       };
        int error;
 
        /* Validate the mount data */
-       error = nfs_validate_mount_data(data, &mntfh);
+       error = nfs_validate_mount_data(&data, &mntfh, dev_name);
        if (error < 0)
                goto out;
 
@@ -667,9 +1398,13 @@ static int nfs_get_sb(struct file_system_type *fs_type,
                error = PTR_ERR(server);
                goto out;
        }
+       sb_mntdata.server = server;
+
+       if (server->flags & NFS_MOUNT_UNSHARED)
+               compare_super = NULL;
 
        /* Get a superblock - note that we may end up sharing one that already exists */
-       s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
+       s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
                goto out_err_nosb;
@@ -682,7 +1417,6 @@ static int nfs_get_sb(struct file_system_type *fs_type,
 
        if (!s->s_root) {
                /* initial superblock/root creation */
-               s->s_flags = flags;
                nfs_fill_super(s, data);
        }
 
@@ -698,6 +1432,8 @@ static int nfs_get_sb(struct file_system_type *fs_type,
        error = 0;
 
 out:
+       if (data != raw_data)
+               kfree(data);
        return error;
 
 out_err_nosb:
@@ -732,6 +1468,10 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
        struct super_block *s;
        struct nfs_server *server;
        struct dentry *mntroot;
+       int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+       struct nfs_sb_mountdata sb_mntdata = {
+               .mntflags = flags,
+       };
        int error;
 
        dprintk("--> nfs_xdev_get_sb()\n");
@@ -742,9 +1482,13 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
                error = PTR_ERR(server);
                goto out_err_noserver;
        }
+       sb_mntdata.server = server;
+
+       if (server->flags & NFS_MOUNT_UNSHARED)
+               compare_super = NULL;
 
        /* Get a superblock - note that we may end up sharing one that already exists */
-       s = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
+       s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
                goto out_err_nosb;
@@ -757,7 +1501,6 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
 
        if (!s->s_root) {
                /* initial superblock/root creation */
-               s->s_flags = flags;
                nfs_clone_super(s, data->sb);
        }
 
@@ -871,8 +1614,93 @@ static int nfs4_validate_mount_data(struct nfs4_mount_data **options,
                *ip_addr = c;
 
                break;
-       default:
-               goto out_bad_version;
+       default: {
+               unsigned int len;
+               struct nfs_parsed_mount_data args = {
+                       .rsize          = NFS_MAX_FILE_IO_SIZE,
+                       .wsize          = NFS_MAX_FILE_IO_SIZE,
+                       .timeo          = 600,
+                       .retrans        = 2,
+                       .acregmin       = 3,
+                       .acregmax       = 60,
+                       .acdirmin       = 30,
+                       .acdirmax       = 60,
+                       .nfs_server.protocol = IPPROTO_TCP,
+               };
+
+               if (nfs_parse_mount_options((char *) *options, &args) == 0)
+                       return -EINVAL;
+
+               if (!nfs_verify_server_address((struct sockaddr *)
+                                               &args.nfs_server.address))
+                       return -EINVAL;
+               *addr = args.nfs_server.address;
+
+               switch (args.auth_flavor_len) {
+               case 0:
+                       *authflavour = RPC_AUTH_UNIX;
+                       break;
+               case 1:
+                       *authflavour = (rpc_authflavor_t) args.auth_flavors[0];
+                       break;
+               default:
+                       goto out_inval_auth;
+               }
+
+               /*
+                * Translate to nfs4_mount_data, which nfs4_fill_super
+                * can deal with.
+                */
+               data = kzalloc(sizeof(*data), GFP_KERNEL);
+               if (data == NULL)
+                       return -ENOMEM;
+               *options = data;
+
+               data->version   = 1;
+               data->flags     = args.flags & NFS4_MOUNT_FLAGMASK;
+               data->rsize     = args.rsize;
+               data->wsize     = args.wsize;
+               data->timeo     = args.timeo;
+               data->retrans   = args.retrans;
+               data->acregmin  = args.acregmin;
+               data->acregmax  = args.acregmax;
+               data->acdirmin  = args.acdirmin;
+               data->acdirmax  = args.acdirmax;
+               data->proto     = args.nfs_server.protocol;
+
+               /*
+                * Split "dev_name" into "hostname:mntpath".
+                */
+               c = strchr(dev_name, ':');
+               if (c == NULL)
+                       return -EINVAL;
+               /* while calculating len, pretend ':' is '\0' */
+               len = c - dev_name;
+               if (len > NFS4_MAXNAMLEN)
+                       return -ENAMETOOLONG;
+               *hostname = kzalloc(len, GFP_KERNEL);
+               if (*hostname == NULL)
+                       return -ENOMEM;
+               strncpy(*hostname, dev_name, len - 1);
+
+               c++;                    /* step over the ':' */
+               len = strlen(c);
+               if (len > NFS4_MAXPATHLEN)
+                       return -ENAMETOOLONG;
+               *mntpath = kzalloc(len + 1, GFP_KERNEL);
+               if (*mntpath == NULL)
+                       return -ENOMEM;
+               strncpy(*mntpath, c, len);
+
+               dprintk("MNTPATH: %s\n", *mntpath);
+
+               if (args.client_address == NULL)
+                       goto out_no_client_address;
+
+               *ip_addr = args.client_address;
+
+               break;
+               }
        }
 
        return 0;
@@ -890,9 +1718,8 @@ out_no_address:
        dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
        return -EINVAL;
 
-out_bad_version:
-       dfprintk(MOUNT, "NFS4: bad nfs_mount_data version %d\n",
-                data->version);
+out_no_client_address:
+       dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
        return -EINVAL;
 }
 
@@ -910,6 +1737,10 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
        struct nfs_fh mntfh;
        struct dentry *mntroot;
        char *mntpath = NULL, *hostname = NULL, *ip_addr = NULL;
+       int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+       struct nfs_sb_mountdata sb_mntdata = {
+               .mntflags = flags,
+       };
        int error;
 
        /* Validate the mount data */
@@ -925,9 +1756,13 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
                error = PTR_ERR(server);
                goto out;
        }
+       sb_mntdata.server = server;
+
+       if (server->flags & NFS4_MOUNT_UNSHARED)
+               compare_super = NULL;
 
        /* Get a superblock - note that we may end up sharing one that already exists */
-       s = sget(fs_type, nfs_compare_super, nfs_set_super, server);
+       s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
                goto out_free;
@@ -940,7 +1775,6 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
 
        if (!s->s_root) {
                /* initial superblock/root creation */
-               s->s_flags = flags;
                nfs4_fill_super(s);
        }
 
@@ -993,6 +1827,10 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
        struct super_block *s;
        struct nfs_server *server;
        struct dentry *mntroot;
+       int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+       struct nfs_sb_mountdata sb_mntdata = {
+               .mntflags = flags,
+       };
        int error;
 
        dprintk("--> nfs4_xdev_get_sb()\n");
@@ -1003,9 +1841,13 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
                error = PTR_ERR(server);
                goto out_err_noserver;
        }
+       sb_mntdata.server = server;
+
+       if (server->flags & NFS4_MOUNT_UNSHARED)
+               compare_super = NULL;
 
        /* Get a superblock - note that we may end up sharing one that already exists */
-       s = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
+       s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
                goto out_err_nosb;
@@ -1018,7 +1860,6 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
 
        if (!s->s_root) {
                /* initial superblock/root creation */
-               s->s_flags = flags;
                nfs4_clone_super(s, data->sb);
        }
 
@@ -1060,6 +1901,10 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
        struct nfs_server *server;
        struct dentry *mntroot;
        struct nfs_fh mntfh;
+       int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+       struct nfs_sb_mountdata sb_mntdata = {
+               .mntflags = flags,
+       };
        int error;
 
        dprintk("--> nfs4_referral_get_sb()\n");
@@ -1070,9 +1915,13 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
                error = PTR_ERR(server);
                goto out_err_noserver;
        }
+       sb_mntdata.server = server;
+
+       if (server->flags & NFS4_MOUNT_UNSHARED)
+               compare_super = NULL;
 
        /* Get a superblock - note that we may end up sharing one that already exists */
-       s = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
+       s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
                goto out_err_nosb;
@@ -1085,7 +1934,6 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
 
        if (!s->s_root) {
                /* initial superblock/root creation */
-               s->s_flags = flags;
                nfs4_fill_super(s);
        }