obj-$(CONFIG_NFS_FS) += nfs.o
 
-nfs-y                  := client.o dir.o file.o inode.o super.o nfs2xdr.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      
 
 
 static DEFINE_SPINLOCK(nfs_client_lock);
 static LIST_HEAD(nfs_client_list);
+static LIST_HEAD(nfs_volume_list);
 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
 
 /*
  * Look up a client by IP address and protocol version
  * - creates a new record if one doesn't yet exist
  */
-struct nfs_client *nfs_get_client(const char *hostname,
-                                 const struct sockaddr_in *addr,
-                                 int nfsversion)
+static struct nfs_client *nfs_get_client(const char *hostname,
+                                        const struct sockaddr_in *addr,
+                                        int nfsversion)
 {
        struct nfs_client *clp, *new = NULL;
        int error;
                return ERR_PTR(error);
        }
 
+       BUG_ON(clp->cl_cons_state != NFS_CS_READY);
+
        dprintk("--> nfs_get_client() = %p [share]\n", clp);
        return clp;
 }
 /*
  * Mark a server as ready or failed
  */
-void nfs_mark_client_ready(struct nfs_client *clp, int state)
+static void nfs_mark_client_ready(struct nfs_client *clp, int state)
 {
        clp->cl_cons_state = state;
        wake_up_all(&nfs_client_active_wq);
 /*
  * Create an RPC client handle
  */
-int nfs_create_rpc_client(struct nfs_client *clp, int proto,
-                         unsigned int timeo,
-                         unsigned int retrans,
-                         rpc_authflavor_t flavor)
+static int nfs_create_rpc_client(struct nfs_client *clp, int proto,
+                                               unsigned int timeo,
+                                               unsigned int retrans,
+                                               rpc_authflavor_t flavor)
 {
        struct rpc_timeout      timeparms;
        struct rpc_xprt         *xprt = NULL;
        clp->cl_rpcclient = clnt;
        return 0;
 }
+
+/*
+ * Version 2 or 3 client destruction
+ */
+static void nfs_destroy_server(struct nfs_server *server)
+{
+       if (!IS_ERR(server->client_acl))
+               rpc_shutdown_client(server->client_acl);
+
+       if (!(server->flags & NFS_MOUNT_NONLM))
+               lockd_down();   /* release rpc.lockd */
+}
+
+/*
+ * Version 2 or 3 lockd setup
+ */
+static int nfs_start_lockd(struct nfs_server *server)
+{
+       int error = 0;
+
+       if (server->nfs_client->cl_nfsversion > 3)
+               goto out;
+       if (server->flags & NFS_MOUNT_NONLM)
+               goto out;
+       error = lockd_up();
+       if (error < 0)
+               server->flags |= NFS_MOUNT_NONLM;
+       else
+               server->destroy = nfs_destroy_server;
+out:
+       return error;
+}
+
+/*
+ * Initialise an NFSv3 ACL client connection
+ */
+#ifdef CONFIG_NFS_V3_ACL
+static void nfs_init_server_aclclient(struct nfs_server *server)
+{
+       if (server->nfs_client->cl_nfsversion != 3)
+               goto out_noacl;
+       if (server->flags & NFS_MOUNT_NOACL)
+               goto out_noacl;
+
+       server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
+       if (IS_ERR(server->client_acl))
+               goto out_noacl;
+
+       /* No errors! Assume that Sun nfsacls are supported */
+       server->caps |= NFS_CAP_ACLS;
+       return;
+
+out_noacl:
+       server->caps &= ~NFS_CAP_ACLS;
+}
+#else
+static inline void nfs_init_server_aclclient(struct nfs_server *server)
+{
+       server->flags &= ~NFS_MOUNT_NOACL;
+       server->caps &= ~NFS_CAP_ACLS;
+}
+#endif
+
+/*
+ * Create a general RPC client
+ */
+static int nfs_init_server_rpcclient(struct nfs_server *server, rpc_authflavor_t pseudoflavour)
+{
+       struct nfs_client *clp = server->nfs_client;
+
+       server->client = rpc_clone_client(clp->cl_rpcclient);
+       if (IS_ERR(server->client)) {
+               dprintk("%s: couldn't create rpc_client!\n", __FUNCTION__);
+               return PTR_ERR(server->client);
+       }
+
+       if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
+               struct rpc_auth *auth;
+
+               auth = rpcauth_create(pseudoflavour, server->client);
+               if (IS_ERR(auth)) {
+                       dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
+                       return PTR_ERR(auth);
+               }
+       }
+       server->client->cl_softrtry = 0;
+       if (server->flags & NFS_MOUNT_SOFT)
+               server->client->cl_softrtry = 1;
+
+       server->client->cl_intr = 0;
+       if (server->flags & NFS4_MOUNT_INTR)
+               server->client->cl_intr = 1;
+
+       return 0;
+}
+
+/*
+ * Initialise an NFS2 or NFS3 client
+ */
+static int nfs_init_client(struct nfs_client *clp, const struct nfs_mount_data *data)
+{
+       int proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
+       int error;
+
+       if (clp->cl_cons_state == NFS_CS_READY) {
+               /* the client is already initialised */
+               dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
+               return 0;
+       }
+
+       /* Check NFS protocol revision and initialize RPC op vector */
+       clp->rpc_ops = &nfs_v2_clientops;
+#ifdef CONFIG_NFS_V3
+       if (clp->cl_nfsversion == 3)
+               clp->rpc_ops = &nfs_v3_clientops;
+#endif
+       /*
+        * Create a client RPC handle for doing FSSTAT with UNIX auth only
+        * - RFC 2623, sec 2.3.2
+        */
+       error = nfs_create_rpc_client(clp, proto, data->timeo, data->retrans,
+                       RPC_AUTH_UNIX);
+       if (error < 0)
+               goto error;
+       nfs_mark_client_ready(clp, NFS_CS_READY);
+       return 0;
+
+error:
+       nfs_mark_client_ready(clp, error);
+       dprintk("<-- nfs_init_client() = xerror %d\n", error);
+       return error;
+}
+
+/*
+ * Create a version 2 or 3 client
+ */
+static int nfs_init_server(struct nfs_server *server, const struct nfs_mount_data *data)
+{
+       struct nfs_client *clp;
+       int error, nfsvers = 2;
+
+       dprintk("--> nfs_init_server()\n");
+
+#ifdef CONFIG_NFS_V3
+       if (data->flags & NFS_MOUNT_VER3)
+               nfsvers = 3;
+#endif
+
+       /* Allocate or find a client reference we can use */
+       clp = nfs_get_client(data->hostname, &data->addr, nfsvers);
+       if (IS_ERR(clp)) {
+               dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
+               return PTR_ERR(clp);
+       }
+
+       error = nfs_init_client(clp, data);
+       if (error < 0)
+               goto error;
+
+       server->nfs_client = clp;
+
+       /* Initialise the client representation from the mount data */
+       server->flags = data->flags & NFS_MOUNT_FLAGMASK;
+
+       if (data->rsize)
+               server->rsize = nfs_block_size(data->rsize, NULL);
+       if (data->wsize)
+               server->wsize = nfs_block_size(data->wsize, NULL);
+
+       server->acregmin = data->acregmin * HZ;
+       server->acregmax = data->acregmax * HZ;
+       server->acdirmin = data->acdirmin * HZ;
+       server->acdirmax = data->acdirmax * HZ;
+
+       /* Start lockd here, before we might error out */
+       error = nfs_start_lockd(server);
+       if (error < 0)
+               goto error;
+
+       error = nfs_init_server_rpcclient(server, data->pseudoflavor);
+       if (error < 0)
+               goto error;
+
+       server->namelen  = data->namlen;
+       /* Create a client RPC handle for the NFSv3 ACL management interface */
+       nfs_init_server_aclclient(server);
+       if (clp->cl_nfsversion == 3) {
+               if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
+                       server->namelen = NFS3_MAXNAMLEN;
+               server->caps |= NFS_CAP_READDIRPLUS;
+       } else {
+               if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
+                       server->namelen = NFS2_MAXNAMLEN;
+       }
+
+       dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
+       return 0;
+
+error:
+       server->nfs_client = NULL;
+       nfs_put_client(clp);
+       dprintk("<-- nfs_init_server() = xerror %d\n", error);
+       return error;
+}
+
+/*
+ * Load up the server record from information gained in an fsinfo record
+ */
+static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *fsinfo)
+{
+       unsigned long max_rpc_payload;
+
+       /* Work out a lot of parameters */
+       if (server->rsize == 0)
+               server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
+       if (server->wsize == 0)
+               server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
+
+       if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
+               server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
+       if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
+               server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
+
+       max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
+       if (server->rsize > max_rpc_payload)
+               server->rsize = max_rpc_payload;
+       if (server->rsize > NFS_MAX_FILE_IO_SIZE)
+               server->rsize = NFS_MAX_FILE_IO_SIZE;
+       server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+       server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
+
+       if (server->wsize > max_rpc_payload)
+               server->wsize = max_rpc_payload;
+       if (server->wsize > NFS_MAX_FILE_IO_SIZE)
+               server->wsize = NFS_MAX_FILE_IO_SIZE;
+       server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+       server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
+
+       server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
+       if (server->dtsize > PAGE_CACHE_SIZE)
+               server->dtsize = PAGE_CACHE_SIZE;
+       if (server->dtsize > server->rsize)
+               server->dtsize = server->rsize;
+
+       if (server->flags & NFS_MOUNT_NOAC) {
+               server->acregmin = server->acregmax = 0;
+               server->acdirmin = server->acdirmax = 0;
+       }
+
+       server->maxfilesize = fsinfo->maxfilesize;
+
+       /* We're airborne Set socket buffersize */
+       rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
+}
+
+/*
+ * Probe filesystem information, including the FSID on v2/v3
+ */
+static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
+{
+       struct nfs_fsinfo fsinfo;
+       struct nfs_client *clp = server->nfs_client;
+       int error;
+
+       dprintk("--> nfs_probe_fsinfo()\n");
+
+       if (clp->rpc_ops->set_capabilities != NULL) {
+               error = clp->rpc_ops->set_capabilities(server, mntfh);
+               if (error < 0)
+                       goto out_error;
+       }
+
+       fsinfo.fattr = fattr;
+       nfs_fattr_init(fattr);
+       error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
+       if (error < 0)
+               goto out_error;
+
+       nfs_server_set_fsinfo(server, &fsinfo);
+
+       /* Get some general file system info */
+       if (server->namelen == 0) {
+               struct nfs_pathconf pathinfo;
+
+               pathinfo.fattr = fattr;
+               nfs_fattr_init(fattr);
+
+               if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
+                       server->namelen = pathinfo.max_namelen;
+       }
+
+       dprintk("<-- nfs_probe_fsinfo() = 0\n");
+       return 0;
+
+out_error:
+       dprintk("nfs_probe_fsinfo: error = %d\n", -error);
+       return error;
+}
+
+/*
+ * Copy useful information when duplicating a server record
+ */
+static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
+{
+       target->flags = source->flags;
+       target->acregmin = source->acregmin;
+       target->acregmax = source->acregmax;
+       target->acdirmin = source->acdirmin;
+       target->acdirmax = source->acdirmax;
+       target->caps = source->caps;
+}
+
+/*
+ * Allocate and initialise a server record
+ */
+static struct nfs_server *nfs_alloc_server(void)
+{
+       struct nfs_server *server;
+
+       server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
+       if (!server)
+               return NULL;
+
+       server->client = server->client_acl = ERR_PTR(-EINVAL);
+
+       /* Zero out the NFS state stuff */
+       INIT_LIST_HEAD(&server->client_link);
+       INIT_LIST_HEAD(&server->master_link);
+
+       server->io_stats = nfs_alloc_iostats();
+       if (!server->io_stats) {
+               kfree(server);
+               return NULL;
+       }
+
+       return server;
+}
+
+/*
+ * Free up a server record
+ */
+void nfs_free_server(struct nfs_server *server)
+{
+       dprintk("--> nfs_free_server()\n");
+
+       spin_lock(&nfs_client_lock);
+       list_del(&server->client_link);
+       list_del(&server->master_link);
+       spin_unlock(&nfs_client_lock);
+
+       if (server->destroy != NULL)
+               server->destroy(server);
+       if (!IS_ERR(server->client))
+               rpc_shutdown_client(server->client);
+
+       nfs_put_client(server->nfs_client);
+
+       nfs_free_iostats(server->io_stats);
+       kfree(server);
+       nfs_release_automount_timer();
+       dprintk("<-- nfs_free_server()\n");
+}
+
+/*
+ * Create a version 2 or 3 volume record
+ * - keyed on server and FSID
+ */
+struct nfs_server *nfs_create_server(const struct nfs_mount_data *data,
+                                    struct nfs_fh *mntfh)
+{
+       struct nfs_server *server;
+       struct nfs_fattr fattr;
+       int error;
+
+       server = nfs_alloc_server();
+       if (!server)
+               return ERR_PTR(-ENOMEM);
+
+       /* Get a client representation */
+       error = nfs_init_server(server, data);
+       if (error < 0)
+               goto error;
+
+       BUG_ON(!server->nfs_client);
+       BUG_ON(!server->nfs_client->rpc_ops);
+       BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
+
+       /* Probe the root fh to retrieve its FSID */
+       error = nfs_probe_fsinfo(server, mntfh, &fattr);
+       if (error < 0)
+               goto error;
+       if (!(fattr.valid & NFS_ATTR_FATTR)) {
+               error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
+               if (error < 0) {
+                       dprintk("nfs_create_server: getattr error = %d\n", -error);
+                       goto error;
+               }
+       }
+       memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
+
+       dprintk("Server FSID: %llx:%llx\n", server->fsid.major, server->fsid.minor);
+
+       BUG_ON(!server->nfs_client);
+       BUG_ON(!server->nfs_client->rpc_ops);
+       BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
+
+       spin_lock(&nfs_client_lock);
+       list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
+       list_add_tail(&server->master_link, &nfs_volume_list);
+       spin_unlock(&nfs_client_lock);
+
+       server->mount_time = jiffies;
+       return server;
+
+error:
+       nfs_free_server(server);
+       return ERR_PTR(error);
+}
+
+#ifdef CONFIG_NFS_V4
+/*
+ * Initialise an NFS4 client record
+ */
+static int nfs4_init_client(struct nfs_client *clp,
+               int proto, int timeo, int retrans,
+               rpc_authflavor_t authflavour)
+{
+       int error;
+
+       if (clp->cl_cons_state == NFS_CS_READY) {
+               /* the client is initialised already */
+               dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
+               return 0;
+       }
+
+       /* Check NFS protocol revision and initialize RPC op vector */
+       clp->rpc_ops = &nfs_v4_clientops;
+
+       error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour);
+       if (error < 0)
+               goto error;
+
+       error = nfs_idmap_new(clp);
+       if (error < 0) {
+               dprintk("%s: failed to create idmapper. Error = %d\n",
+                       __FUNCTION__, error);
+               __set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
+               goto error;
+       }
+
+       nfs_mark_client_ready(clp, NFS_CS_READY);
+       return 0;
+
+error:
+       nfs_mark_client_ready(clp, error);
+       dprintk("<-- nfs4_init_client() = xerror %d\n", error);
+       return error;
+}
+
+/*
+ * Set up an NFS4 client
+ */
+static int nfs4_set_client(struct nfs_server *server,
+               const char *hostname, const struct sockaddr_in *addr,
+               rpc_authflavor_t authflavour,
+               int proto, int timeo, int retrans)
+{
+       struct nfs_client *clp;
+       int error;
+
+       dprintk("--> nfs4_set_client()\n");
+
+       /* Allocate or find a client reference we can use */
+       clp = nfs_get_client(hostname, addr, 4);
+       if (IS_ERR(clp)) {
+               error = PTR_ERR(clp);
+               goto error;
+       }
+       error = nfs4_init_client(clp, proto, timeo, retrans, authflavour);
+       if (error < 0)
+               goto error_put;
+
+       server->nfs_client = clp;
+       dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
+       return 0;
+
+error_put:
+       nfs_put_client(clp);
+error:
+       dprintk("<-- nfs4_set_client() = xerror %d\n", error);
+       return error;
+}
+
+/*
+ * Create a version 4 volume record
+ */
+static int nfs4_init_server(struct nfs_server *server,
+               const struct nfs4_mount_data *data, rpc_authflavor_t authflavour)
+{
+       int error;
+
+       dprintk("--> nfs4_init_server()\n");
+
+       /* Initialise the client representation from the mount data */
+       server->flags = data->flags & NFS_MOUNT_FLAGMASK;
+       server->caps |= NFS_CAP_ATOMIC_OPEN;
+
+       if (data->rsize)
+               server->rsize = nfs_block_size(data->rsize, NULL);
+       if (data->wsize)
+               server->wsize = nfs_block_size(data->wsize, NULL);
+
+       server->acregmin = data->acregmin * HZ;
+       server->acregmax = data->acregmax * HZ;
+       server->acdirmin = data->acdirmin * HZ;
+       server->acdirmax = data->acdirmax * HZ;
+
+       error = nfs_init_server_rpcclient(server, authflavour);
+
+       /* Done */
+       dprintk("<-- nfs4_init_server() = %d\n", error);
+       return error;
+}
+
+/*
+ * Create a version 4 volume record
+ * - keyed on server and FSID
+ */
+struct nfs_server *nfs4_create_server(const struct nfs4_mount_data *data,
+                                     const char *hostname,
+                                     const struct sockaddr_in *addr,
+                                     const char *mntpath,
+                                     const char *ip_addr,
+                                     rpc_authflavor_t authflavour,
+                                     struct nfs_fh *mntfh)
+{
+       struct nfs_fattr fattr;
+       struct nfs_server *server;
+       int error;
+
+       dprintk("--> nfs4_create_server()\n");
+
+       server = nfs_alloc_server();
+       if (!server)
+               return ERR_PTR(-ENOMEM);
+
+       /* Get a client record */
+       error = nfs4_set_client(server, hostname, addr, authflavour,
+                       data->proto, data->timeo, data->retrans);
+       if (error < 0)
+               goto error;
+
+       /* set up the general RPC client */
+       error = nfs4_init_server(server, data, authflavour);
+       if (error < 0)
+               goto error;
+
+       BUG_ON(!server->nfs_client);
+       BUG_ON(!server->nfs_client->rpc_ops);
+       BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
+
+       /* Probe the root fh to retrieve its FSID */
+       error = nfs4_path_walk(server, mntfh, mntpath);
+       if (error < 0)
+               goto error;
+
+       dprintk("Server FSID: %llx:%llx\n", server->fsid.major, server->fsid.minor);
+       dprintk("Mount FH: %d\n", mntfh->size);
+
+       error = nfs_probe_fsinfo(server, mntfh, &fattr);
+       if (error < 0)
+               goto error;
+
+       BUG_ON(!server->nfs_client);
+       BUG_ON(!server->nfs_client->rpc_ops);
+       BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
+
+       spin_lock(&nfs_client_lock);
+       list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
+       list_add_tail(&server->master_link, &nfs_volume_list);
+       spin_unlock(&nfs_client_lock);
+
+       server->mount_time = jiffies;
+       dprintk("<-- nfs4_create_server() = %p\n", server);
+       return server;
+
+error:
+       nfs_free_server(server);
+       dprintk("<-- nfs4_create_server() = error %d\n", error);
+       return ERR_PTR(error);
+}
+
+/*
+ * Create an NFS4 referral server record
+ */
+struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
+                                              struct nfs_fh *fh)
+{
+       struct nfs_client *parent_client;
+       struct nfs_server *server, *parent_server;
+       struct nfs_fattr fattr;
+       int error;
+
+       dprintk("--> nfs4_create_referral_server()\n");
+
+       server = nfs_alloc_server();
+       if (!server)
+               return ERR_PTR(-ENOMEM);
+
+       parent_server = NFS_SB(data->sb);
+       parent_client = parent_server->nfs_client;
+
+       /* Get a client representation.
+        * Note: NFSv4 always uses TCP, */
+       error = nfs4_set_client(server, data->hostname, data->addr,
+                       data->authflavor,
+                       parent_server->client->cl_xprt->prot,
+                       parent_client->retrans_timeo,
+                       parent_client->retrans_count);
+
+       /* Initialise the client representation from the parent server */
+       nfs_server_copy_userdata(server, parent_server);
+       server->caps |= NFS_CAP_ATOMIC_OPEN;
+
+       error = nfs_init_server_rpcclient(server, data->authflavor);
+       if (error < 0)
+               goto error;
+
+       BUG_ON(!server->nfs_client);
+       BUG_ON(!server->nfs_client->rpc_ops);
+       BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
+
+       /* probe the filesystem info for this server filesystem */
+       error = nfs_probe_fsinfo(server, fh, &fattr);
+       if (error < 0)
+               goto error;
+
+       dprintk("Referral FSID: %llx:%llx\n",
+               server->fsid.major, server->fsid.minor);
+
+       spin_lock(&nfs_client_lock);
+       list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
+       list_add_tail(&server->master_link, &nfs_volume_list);
+       spin_unlock(&nfs_client_lock);
+
+       server->mount_time = jiffies;
+
+       dprintk("<-- nfs_create_referral_server() = %p\n", server);
+       return server;
+
+error:
+       nfs_free_server(server);
+       dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
+       return ERR_PTR(error);
+}
+
+#endif /* CONFIG_NFS_V4 */
+
+/*
+ * Clone an NFS2, NFS3 or NFS4 server record
+ */
+struct nfs_server *nfs_clone_server(struct nfs_server *source,
+                                   struct nfs_fh *fh,
+                                   struct nfs_fattr *fattr)
+{
+       struct nfs_server *server;
+       struct nfs_fattr fattr_fsinfo;
+       int error;
+
+       dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
+               fattr->fsid.major, fattr->fsid.minor);
+
+       server = nfs_alloc_server();
+       if (!server)
+               return ERR_PTR(-ENOMEM);
+
+       /* Copy data from the source */
+       server->nfs_client = source->nfs_client;
+       atomic_inc(&server->nfs_client->cl_count);
+       nfs_server_copy_userdata(server, source);
+
+       server->fsid = fattr->fsid;
+
+       error = nfs_init_server_rpcclient(server, source->client->cl_auth->au_flavor);
+       if (error < 0)
+               goto out_free_server;
+       if (!IS_ERR(source->client_acl))
+               nfs_init_server_aclclient(server);
+
+       /* probe the filesystem info for this server filesystem */
+       error = nfs_probe_fsinfo(server, fh, &fattr_fsinfo);
+       if (error < 0)
+               goto out_free_server;
+
+       dprintk("Cloned FSID: %llx:%llx\n",
+               server->fsid.major, server->fsid.minor);
+
+       error = nfs_start_lockd(server);
+       if (error < 0)
+               goto out_free_server;
+
+       spin_lock(&nfs_client_lock);
+       list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
+       list_add_tail(&server->master_link, &nfs_volume_list);
+       spin_unlock(&nfs_client_lock);
+
+       server->mount_time = jiffies;
+
+       dprintk("<-- nfs_clone_server() = %p\n", server);
+       return server;
+
+out_free_server:
+       nfs_free_server(server);
+       dprintk("<-- nfs_clone_server() = error %d\n", error);
+       return ERR_PTR(error);
+}
 
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
 #include <linux/namei.h>
+#include <linux/mount.h>
 
 #include "nfs4_fs.h"
 #include "delegation.h"
        return (nd->intent.open.flags & O_EXCL) != 0;
 }
 
-static inline int nfs_reval_fsid(struct inode *dir,
-               struct nfs_fh *fh, struct nfs_fattr *fattr)
+static inline int nfs_reval_fsid(struct vfsmount *mnt, struct inode *dir,
+                                struct nfs_fh *fh, struct nfs_fattr *fattr)
 {
        struct nfs_server *server = NFS_SERVER(dir);
 
        if (!nfs_fsid_equal(&server->fsid, &fattr->fsid))
                /* Revalidate fsid on root dir */
-               return __nfs_revalidate_inode(server, dir->i_sb->s_root->d_inode);
+               return __nfs_revalidate_inode(server, mnt->mnt_root->d_inode);
        return 0;
 }
 
                res = ERR_PTR(error);
                goto out_unlock;
        }
-       error = nfs_reval_fsid(dir, &fhandle, &fattr);
+       error = nfs_reval_fsid(nd->mnt, dir, &fhandle, &fattr);
        if (error < 0) {
                res = ERR_PTR(error);
                goto out_unlock;
        res = (struct dentry *)inode;
        if (IS_ERR(res))
                goto out_unlock;
+
 no_entry:
-       res = d_add_unique(dentry, inode);
+       res = d_materialise_unique(dentry, inode);
        if (res != NULL)
                dentry = res;
        nfs_renew_times(dentry);
                dput(dentry);
                return NULL;
        }
-       alias = d_add_unique(dentry, inode);
+
+       alias = d_materialise_unique(dentry, inode);
        if (alias != NULL) {
                dput(dentry);
                dentry = alias;
        }
+
        nfs_renew_times(dentry);
        nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
        return dentry;
 
--- /dev/null
+/* getroot.c: get the root dentry for an NFS mount
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/lockd/bind.h>
+#include <linux/smp_lock.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/nfs_idmap.h>
+#include <linux/vfs.h>
+#include <linux/namei.h>
+#include <linux/namespace.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#include "nfs4_fs.h"
+#include "delegation.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY                NFSDBG_CLIENT
+#define NFS_PARANOIA 1
+
+/*
+ * get an NFS2/NFS3 root dentry from the root filehandle
+ */
+struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
+{
+       struct nfs_server *server = NFS_SB(sb);
+       struct nfs_fsinfo fsinfo;
+       struct nfs_fattr fattr;
+       struct dentry *mntroot;
+       struct inode *inode;
+       int error;
+
+       /* create a dummy root dentry with dummy inode for this superblock */
+       if (!sb->s_root) {
+               struct nfs_fh dummyfh;
+               struct dentry *root;
+               struct inode *iroot;
+
+               memset(&dummyfh, 0, sizeof(dummyfh));
+               memset(&fattr, 0, sizeof(fattr));
+               nfs_fattr_init(&fattr);
+               fattr.valid = NFS_ATTR_FATTR;
+               fattr.type = NFDIR;
+               fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR;
+               fattr.nlink = 2;
+
+               iroot = nfs_fhget(sb, &dummyfh, &fattr);
+               if (IS_ERR(iroot))
+                       return ERR_PTR(PTR_ERR(iroot));
+
+               root = d_alloc_root(iroot);
+               if (!root) {
+                       iput(iroot);
+                       return ERR_PTR(-ENOMEM);
+               }
+
+               sb->s_root = root;
+       }
+
+       /* get the actual root for this mount */
+       fsinfo.fattr = &fattr;
+
+       error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
+       if (error < 0) {
+               dprintk("nfs_get_root: getattr error = %d\n", -error);
+               return ERR_PTR(error);
+       }
+
+       inode = nfs_fhget(sb, mntfh, fsinfo.fattr);
+       if (IS_ERR(inode)) {
+               dprintk("nfs_get_root: get root inode failed\n");
+               return ERR_PTR(PTR_ERR(inode));
+       }
+
+       /* root dentries normally start off anonymous and get spliced in later
+        * if the dentry tree reaches them; however if the dentry already
+        * exists, we'll pick it up at this point and use it as the root
+        */
+       mntroot = d_alloc_anon(inode);
+       if (!mntroot) {
+               iput(inode);
+               dprintk("nfs_get_root: get root dentry failed\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       if (!mntroot->d_op)
+               mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
+
+       return mntroot;
+}
+
+#ifdef CONFIG_NFS_V4
+
+/*
+ * Do a simple pathwalk from the root FH of the server to the nominated target
+ * of the mountpoint
+ * - give error on symlinks
+ * - give error on ".." occurring in the path
+ * - follow traversals
+ */
+int nfs4_path_walk(struct nfs_server *server,
+                  struct nfs_fh *mntfh,
+                  const char *path)
+{
+       struct nfs_fsinfo fsinfo;
+       struct nfs_fattr fattr;
+       struct nfs_fh lastfh;
+       struct qstr name;
+       int ret;
+       //int referral_count = 0;
+
+       dprintk("--> nfs4_path_walk(,,%s)\n", path);
+
+       fsinfo.fattr = &fattr;
+       nfs_fattr_init(&fattr);
+
+       if (*path++ != '/') {
+               dprintk("nfs4_get_root: Path does not begin with a slash\n");
+               return -EINVAL;
+       }
+
+       /* Start by getting the root filehandle from the server */
+       ret = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
+       if (ret < 0) {
+               dprintk("nfs4_get_root: getroot error = %d\n", -ret);
+               return ret;
+       }
+
+       if (fattr.type != NFDIR) {
+               printk(KERN_ERR "nfs4_get_root:"
+                      " getroot encountered non-directory\n");
+               return -ENOTDIR;
+       }
+
+       if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+               printk(KERN_ERR "nfs4_get_root:"
+                      " getroot obtained referral\n");
+               return -EREMOTE;
+       }
+
+next_component:
+       dprintk("Next: %s\n", path);
+
+       /* extract the next bit of the path */
+       if (!*path)
+               goto path_walk_complete;
+
+       name.name = path;
+       while (*path && *path != '/')
+               path++;
+       name.len = path - (const char *) name.name;
+
+eat_dot_dir:
+       while (*path == '/')
+               path++;
+
+       if (path[0] == '.' && (path[1] == '/' || !path[1])) {
+               path += 2;
+               goto eat_dot_dir;
+       }
+
+       if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || !path[2])
+           ) {
+               printk(KERN_ERR "nfs4_get_root:"
+                      " Mount path contains reference to \"..\"\n");
+               return -EINVAL;
+       }
+
+       /* lookup the next FH in the sequence */
+       memcpy(&lastfh, mntfh, sizeof(lastfh));
+
+       dprintk("LookupFH: %*.*s [%s]\n", name.len, name.len, name.name, path);
+
+       ret = server->nfs_client->rpc_ops->lookupfh(server, &lastfh, &name,
+                                                   mntfh, &fattr);
+       if (ret < 0) {
+               dprintk("nfs4_get_root: getroot error = %d\n", -ret);
+               return ret;
+       }
+
+       if (fattr.type != NFDIR) {
+               printk(KERN_ERR "nfs4_get_root:"
+                      " lookupfh encountered non-directory\n");
+               return -ENOTDIR;
+       }
+
+       if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+               printk(KERN_ERR "nfs4_get_root:"
+                      " lookupfh obtained referral\n");
+               return -EREMOTE;
+       }
+
+       goto next_component;
+
+path_walk_complete:
+       memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
+       dprintk("<-- nfs4_path_walk() = 0\n");
+       return 0;
+}
+
+/*
+ * get an NFS4 root dentry from the root filehandle
+ */
+struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
+{
+       struct nfs_server *server = NFS_SB(sb);
+       struct nfs_fattr fattr;
+       struct dentry *mntroot;
+       struct inode *inode;
+       int error;
+
+       dprintk("--> nfs4_get_root()\n");
+
+       /* create a dummy root dentry with dummy inode for this superblock */
+       if (!sb->s_root) {
+               struct nfs_fh dummyfh;
+               struct dentry *root;
+               struct inode *iroot;
+
+               memset(&dummyfh, 0, sizeof(dummyfh));
+               memset(&fattr, 0, sizeof(fattr));
+               nfs_fattr_init(&fattr);
+               fattr.valid = NFS_ATTR_FATTR;
+               fattr.type = NFDIR;
+               fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR;
+               fattr.nlink = 2;
+
+               iroot = nfs_fhget(sb, &dummyfh, &fattr);
+               if (IS_ERR(iroot))
+                       return ERR_PTR(PTR_ERR(iroot));
+
+               root = d_alloc_root(iroot);
+               if (!root) {
+                       iput(iroot);
+                       return ERR_PTR(-ENOMEM);
+               }
+
+               sb->s_root = root;
+       }
+
+       /* get the info about the server and filesystem */
+       error = nfs4_server_capabilities(server, mntfh);
+       if (error < 0) {
+               dprintk("nfs_get_root: getcaps error = %d\n",
+                       -error);
+               return ERR_PTR(error);
+       }
+
+       /* get the actual root for this mount */
+       error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
+       if (error < 0) {
+               dprintk("nfs_get_root: getattr error = %d\n", -error);
+               return ERR_PTR(error);
+       }
+
+       inode = nfs_fhget(sb, mntfh, &fattr);
+       if (IS_ERR(inode)) {
+               dprintk("nfs_get_root: get root inode failed\n");
+               return ERR_PTR(PTR_ERR(inode));
+       }
+
+       /* root dentries normally start off anonymous and get spliced in later
+        * if the dentry tree reaches them; however if the dentry already
+        * exists, we'll pick it up at this point and use it as the root
+        */
+       mntroot = d_alloc_anon(inode);
+       if (!mntroot) {
+               iput(inode);
+               dprintk("nfs_get_root: get root dentry failed\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       if (!mntroot->d_op)
+               mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
+
+       dprintk("<-- nfs4_get_root()\n");
+       return mntroot;
+}
+
+#endif /* CONFIG_NFS_V4 */
 
        struct idmap *idmap;
        int error;
 
-       if (clp->cl_idmap != NULL)
-               return 0;
+       BUG_ON(clp->cl_idmap != NULL);
 
         if ((idmap = kzalloc(sizeof(*idmap), GFP_KERNEL)) == NULL)
                 return -ENOMEM;
 
  out_fileid:
        printk(KERN_ERR "NFS: server %s error: fileid changed\n"
                "fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
-               NFS_SERVER(inode)->hostname, inode->i_sb->s_id,
+               NFS_SERVER(inode)->nfs_client->cl_hostname, inode->i_sb->s_id,
                (long long)nfsi->fileid, (long long)fattr->fileid);
        goto out_err;
 }
 
 
 #include <linux/mount.h>
 
+struct nfs_string;
+struct nfs_mount_data;
+struct nfs4_mount_data;
+
+/* Maximum number of readahead requests
+ * FIXME: this should really be a sysctl so that users may tune it to suit
+ *        their needs. People that do NFS over a slow network, might for
+ *        instance want to reduce it to something closer to 1 for improved
+ *        interactive response.
+ */
+#define NFS_MAX_READAHEAD      (RPC_DEF_SLOT_TABLE - 1)
+
 struct nfs_clone_mount {
        const struct super_block *sb;
        const struct dentry *dentry;
 };
 
 /* client.c */
+extern struct rpc_program nfs_program;
+
 extern void nfs_put_client(struct nfs_client *);
 extern struct nfs_client *nfs_find_client(const struct sockaddr_in *, int);
-extern struct nfs_client *nfs_get_client(const char *, const struct sockaddr_in *, int);
-extern void nfs_mark_client_ready(struct nfs_client *, int);
-extern int nfs_create_rpc_client(struct nfs_client *, int, unsigned int,
-                                unsigned int, rpc_authflavor_t);
+extern struct nfs_server *nfs_create_server(const struct nfs_mount_data *,
+                                           struct nfs_fh *);
+extern struct nfs_server *nfs4_create_server(const struct nfs4_mount_data *,
+                                            const char *,
+                                            const struct sockaddr_in *,
+                                            const char *,
+                                            const char *,
+                                            rpc_authflavor_t,
+                                            struct nfs_fh *);
+extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
+                                                     struct nfs_fh *);
+extern void nfs_free_server(struct nfs_server *server);
+extern struct nfs_server *nfs_clone_server(struct nfs_server *,
+                                          struct nfs_fh *,
+                                          struct nfs_fattr *);
 
 /* nfs4namespace.c */
 #ifdef CONFIG_NFS_V4
 #endif
 
 /* super.c */
-extern struct file_system_type nfs_referral_nfs4_fs_type;
-extern struct file_system_type clone_nfs_fs_type;
+extern struct file_system_type nfs_xdev_fs_type;
 #ifdef CONFIG_NFS_V4
-extern struct file_system_type clone_nfs4_fs_type;
+extern struct file_system_type nfs4_xdev_fs_type;
+extern struct file_system_type nfs4_referral_fs_type;
 #endif
 
 extern struct rpc_stat nfs_rpcstat;
 extern void __exit unregister_nfs_fs(void);
 
 /* namespace.c */
-extern char *nfs_path(const char *base, const struct dentry *dentry,
+extern char *nfs_path(const char *base,
+                     const struct dentry *droot,
+                     const struct dentry *dentry,
                      char *buffer, ssize_t buflen);
 
-/*
- * Determine the mount path as a string
- */
+/* getroot.c */
+extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *);
 #ifdef CONFIG_NFS_V4
-static inline char *
-nfs4_path(const struct dentry *dentry, char *buffer, ssize_t buflen)
-{
-       return nfs_path(NFS_SB(dentry->d_sb)->mnt_path, dentry, buffer, buflen);
-}
+extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *);
+
+extern int nfs4_path_walk(struct nfs_server *server,
+                         struct nfs_fh *mntfh,
+                         const char *path);
 #endif
 
 /*
  * Determine the device name as a string
  */
 static inline char *nfs_devname(const struct vfsmount *mnt_parent,
-                        const struct dentry *dentry,
-                        char *buffer, ssize_t buflen)
+                               const struct dentry *dentry,
+                               char *buffer, ssize_t buflen)
 {
-       return nfs_path(mnt_parent->mnt_devname, dentry, buffer, buflen);
+       return nfs_path(mnt_parent->mnt_devname, mnt_parent->mnt_root,
+                       dentry, buffer, buflen);
 }
 
 /*
        if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
                sb->s_maxbytes = MAX_LFS_FILESIZE;
 }
-
-/*
- * Check if the string represents a "valid" IPv4 address
- */
-static inline int valid_ipaddr4(const char *buf)
-{
-       int rc, count, in[4];
-
-       rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
-       if (rc != 4)
-               return -EINVAL;
-       for (count = 0; count < 4; count++) {
-               if (in[count] > 255)
-                       return -EINVAL;
-       }
-       return 0;
-}
 
  * linux/fs/nfs/namespace.c
  *
  * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
+ * - Modified by David Howells <dhowells@redhat.com>
  *
  * NFS namespace
  */
 /*
  * nfs_path - reconstruct the path given an arbitrary dentry
  * @base - arbitrary string to prepend to the path
+ * @droot - pointer to root dentry for mountpoint
  * @dentry - pointer to dentry
  * @buffer - result buffer
  * @buflen - length of buffer
  * This is mainly for use in figuring out the path on the
  * server side when automounting on top of an existing partition.
  */
-char *nfs_path(const char *base, const struct dentry *dentry,
+char *nfs_path(const char *base,
+              const struct dentry *droot,
+              const struct dentry *dentry,
               char *buffer, ssize_t buflen)
 {
        char *end = buffer+buflen;
        *--end = '\0';
        buflen--;
        spin_lock(&dcache_lock);
-       while (!IS_ROOT(dentry)) {
+       while (!IS_ROOT(dentry) && dentry != droot) {
                namelen = dentry->d_name.len;
                buflen -= namelen + 1;
                if (buflen < 0)
        struct nfs_fattr fattr;
        int err;
 
+       dprintk("--> nfs_follow_mountpoint()\n");
+
        BUG_ON(IS_ROOT(dentry));
        dprintk("%s: enter\n", __FUNCTION__);
        dput(nd->dentry);
        nd->dentry = dget(dentry);
-       if (d_mountpoint(nd->dentry))
-               goto out_follow;
+
        /* Look it up again */
        parent = dget_parent(nd->dentry);
        err = server->nfs_client->rpc_ops->lookup(parent->d_inode,
        schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
 out:
        dprintk("%s: done, returned %d\n", __FUNCTION__, err);
+
+       dprintk("<-- nfs_follow_mountpoint() = %d\n", err);
        return ERR_PTR(err);
 out_err:
        path_release(nd);
        switch (server->nfs_client->cl_nfsversion) {
                case 2:
                case 3:
-                       mnt = vfs_kern_mount(&clone_nfs_fs_type, 0, devname, mountdata);
+                       mnt = vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
                        break;
                case 4:
-                       mnt = vfs_kern_mount(&clone_nfs4_fs_type, 0, devname, mountdata);
+                       mnt = vfs_kern_mount(&nfs4_xdev_fs_type, 0, devname, mountdata);
        }
        return mnt;
 #else
-       return vfs_kern_mount(&clone_nfs_fs_type, 0, devname, mountdata);
+       return vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
 #endif
 }
 
        char *page = (char *) __get_free_page(GFP_USER);
        char *devname;
 
+       dprintk("--> nfs_do_submount()\n");
+
        dprintk("%s: submounting on %s/%s\n", __FUNCTION__,
                        dentry->d_parent->d_name.name,
                        dentry->d_name.name);
        free_page((unsigned long)page);
 out:
        dprintk("%s: done\n", __FUNCTION__);
+
+       dprintk("<-- nfs_do_submount() = %p\n", mnt);
        return mnt;
 }
 
 }
 
 /*
- * Bare-bones access to getattr: this is for nfs_read_super.
+ * Bare-bones access to getattr: this is for nfs_get_root/nfs_get_sb
  */
 static int
 nfs3_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
 
 extern void nfs4_renew_state(void *);
 
 /* nfs4state.c */
-extern void init_nfsv4_state(struct nfs_server *);
-extern void destroy_nfsv4_state(struct nfs_server *);
 struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp);
 extern u32 nfs4_alloc_lockowner_id(struct nfs_client *);
 
 
 #else
 
-#define init_nfsv4_state(server)  do { } while (0)
-#define destroy_nfsv4_state(server)       do { } while (0)
-#define nfs4_put_state_owner(inode, owner) do { } while (0)
-#define nfs4_put_open_state(state) do { } while (0)
 #define nfs4_close_state(a, b) do { } while (0)
 
 #endif /* CONFIG_NFS_V4 */
 
  * linux/fs/nfs/nfs4namespace.c
  *
  * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
+ * - Modified by David Howells <dhowells@redhat.com>
  *
  * NFSv4 namespace
  */
        return ERR_PTR(-ENAMETOOLONG);
 }
 
+/*
+ * Determine the mount path as a string
+ */
+static char *nfs4_path(const struct vfsmount *mnt_parent,
+                      const struct dentry *dentry,
+                      char *buffer, ssize_t buflen)
+{
+       const char *srvpath;
+
+       srvpath = strchr(mnt_parent->mnt_devname, ':');
+       if (srvpath)
+               srvpath++;
+       else
+               srvpath = mnt_parent->mnt_devname;
+
+       return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
+}
+
+/*
+ * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
+ * believe to be the server path to this dentry
+ */
+static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
+                               const struct dentry *dentry,
+                               const struct nfs4_fs_locations *locations,
+                               char *page, char *page2)
+{
+       const char *path, *fs_path;
+
+       path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
+       if (IS_ERR(path))
+               return PTR_ERR(path);
+
+       fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
+       if (IS_ERR(fs_path))
+               return PTR_ERR(fs_path);
+
+       if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
+               dprintk("%s: path %s does not begin with fsroot %s\n",
+                       __FUNCTION__, path, fs_path);
+               return -ENOENT;
+       }
+
+       return 0;
+}
+
+/*
+ * Check if the string represents a "valid" IPv4 address
+ */
+static inline int valid_ipaddr4(const char *buf)
+{
+       int rc, count, in[4];
+
+       rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
+       if (rc != 4)
+               return -EINVAL;
+       for (count = 0; count < 4; count++) {
+               if (in[count] > 255)
+                       return -EINVAL;
+       }
+       return 0;
+}
 
 /**
  * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
                .dentry = dentry,
                .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
        };
-       char *page, *page2;
-       char *path, *fs_path;
+       char *page = NULL, *page2 = NULL;
        char *devname;
-       int loc, s;
+       int loc, s, error;
 
        if (locations == NULL || locations->nlocations <= 0)
                goto out;
        dprintk("%s: referral at %s/%s\n", __FUNCTION__,
                dentry->d_parent->d_name.name, dentry->d_name.name);
 
-       /* Ensure fs path is a prefix of current dentry path */
        page = (char *) __get_free_page(GFP_USER);
-       if (page == NULL)
+       if (!page)
                goto out;
+
        page2 = (char *) __get_free_page(GFP_USER);
-       if (page2 == NULL)
+       if (!page2)
                goto out;
 
-       path = nfs4_path(dentry, page, PAGE_SIZE);
-       if (IS_ERR(path))
-               goto out_free;
-
-       fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
-       if (IS_ERR(fs_path))
-               goto out_free;
-
-       if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
-               dprintk("%s: path %s does not begin with fsroot %s\n", __FUNCTION__, path, fs_path);
-               goto out_free;
+       /* Ensure fs path is a prefix of current dentry path */
+       error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
+       if (error < 0) {
+               mnt = ERR_PTR(error);
+               goto out;
        }
 
        devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
        if (IS_ERR(devname)) {
                mnt = (struct vfsmount *)devname;
-               goto out_free;
+               goto out;
        }
 
        loc = 0;
                        addr.sin_port = htons(NFS_PORT);
                        mountdata.addr = &addr;
 
-                       mnt = vfs_kern_mount(&nfs_referral_nfs4_fs_type, 0, devname, &mountdata);
+                       mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, devname, &mountdata);
                        if (!IS_ERR(mnt)) {
                                break;
                        }
                loc++;
        }
 
-out_free:
-       free_page((unsigned long)page);
-       free_page((unsigned long)page2);
 out:
+       free_page((unsigned long) page);
+       free_page((unsigned long) page2);
        dprintk("%s: done\n", __FUNCTION__);
        return mnt;
 }
  */
 struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
 {
-       struct vfsmount *mnt = ERR_PTR(-ENOENT);
+       struct vfsmount *mnt = ERR_PTR(-ENOMEM);
        struct dentry *parent;
        struct nfs4_fs_locations *fs_locations = NULL;
        struct page *page;
                goto out_free;
 
        /* Get locations */
+       mnt = ERR_PTR(-ENOENT);
+
        parent = dget_parent(dentry);
-       dprintk("%s: getting locations for %s/%s\n", __FUNCTION__, parent->d_name.name, dentry->d_name.name);
+       dprintk("%s: getting locations for %s/%s\n",
+               __FUNCTION__, parent->d_name.name, dentry->d_name.name);
+
        err = nfs4_proc_fs_locations(parent->d_inode, dentry, fs_locations, page);
        dput(parent);
-       if (err != 0 || fs_locations->nlocations <= 0 ||
+       if (err != 0 ||
+           fs_locations->nlocations <= 0 ||
            fs_locations->fs_path.ncomponents <= 0)
                goto out_free;
 
 
        return err;
 }
 
+/*
+ * get the file handle for the "/" directory on the server
+ */
 static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
-               struct nfs_fsinfo *info)
+                             struct nfs_fsinfo *info)
 {
-       struct nfs_fattr *      fattr = info->fattr;
-       unsigned char *         p;
-       struct qstr             q;
-       struct nfs4_lookup_arg args = {
-               .dir_fh = fhandle,
-               .name = &q,
-               .bitmask = nfs4_fattr_bitmap,
-       };
-       struct nfs4_lookup_res res = {
-               .server = server,
-               .fattr = fattr,
-               .fh = fhandle,
-       };
-       struct rpc_message msg = {
-               .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP],
-               .rpc_argp = &args,
-               .rpc_resp = &res,
-       };
        int status;
 
-       /*
-        * Now we do a separate LOOKUP for each component of the mount path.
-        * The LOOKUPs are done separately so that we can conveniently
-        * catch an ERR_WRONGSEC if it occurs along the way...
-        */
        status = nfs4_lookup_root(server, fhandle, info);
-       if (status)
-               goto out;
-
-       p = server->mnt_path;
-       for (;;) {
-               struct nfs4_exception exception = { };
-
-               while (*p == '/')
-                       p++;
-               if (!*p)
-                       break;
-               q.name = p;
-               while (*p && (*p != '/'))
-                       p++;
-               q.len = p - q.name;
-
-               do {
-                       nfs_fattr_init(fattr);
-                       status = nfs4_handle_exception(server,
-                                       rpc_call_sync(server->client, &msg, 0),
-                                       &exception);
-               } while (exception.retry);
-               if (status == 0)
-                       continue;
-               if (status == -ENOENT) {
-                       printk(KERN_NOTICE "NFS: mount path %s does not exist!\n", server->mnt_path);
-                       printk(KERN_NOTICE "NFS: suggestion: try mounting '/' instead.\n");
-               }
-               break;
-       }
        if (status == 0)
                status = nfs4_server_capabilities(server, fhandle);
        if (status == 0)
                status = nfs4_do_fsinfo(server, fhandle, info);
-out:
        return nfs4_map_errors(status);
 }
 
 
 void
 nfs4_renewd_prepare_shutdown(struct nfs_server *server)
 {
-       struct nfs_client *clp = server->nfs_client;
-
-       if (!clp)
-               return;
        flush_scheduled_work();
-       down_write(&clp->cl_sem);
-       if (!list_empty(&server->nfs4_siblings))
-               list_del_init(&server->nfs4_siblings);
-       up_write(&clp->cl_sem);
 }
 
-/* Must be called with clp->cl_sem locked for writes */
 void
 nfs4_kill_renewd(struct nfs_client *clp)
 {
        down_read(&clp->cl_sem);
-       if (!list_empty(&clp->cl_superblocks)) {
-               up_read(&clp->cl_sem);
-               return;
-       }
        cancel_delayed_work(&clp->cl_renewd);
        up_read(&clp->cl_sem);
        flush_scheduled_work();
 
 
 static LIST_HEAD(nfs4_clientid_list);
 
-void
-init_nfsv4_state(struct nfs_server *server)
-{
-       server->nfs_client = NULL;
-       INIT_LIST_HEAD(&server->nfs4_siblings);
-}
-
-void
-destroy_nfsv4_state(struct nfs_server *server)
-{
-       kfree(server->mnt_path);
-       server->mnt_path = NULL;
-       if (server->nfs_client) {
-               nfs_put_client(server->nfs_client);
-               server->nfs_client = NULL;
-       }
-}
-
 static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
 {
        int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
 
                rdata->args.offset = page_offset(page) + rdata->args.pgbase;
 
                dprintk("NFS: nfs_proc_read(%s, (%s/%Ld), %Lu, %u)\n",
-                       NFS_SERVER(inode)->hostname,
+                       NFS_SERVER(inode)->nfs_client->cl_hostname,
                        inode->i_sb->s_id,
                        (long long)NFS_FILEID(inode),
                        (unsigned long long)rdata->args.pgbase,
 
  *
  *  Split from inode.c by David Howells <dhowells@redhat.com>
  *
+ * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
+ *   particular server are held in the same superblock
+ * - NFS superblocks can have several effective roots to the dentry tree
+ * - directory type roots are spliced into the tree when a path from one root reaches the root
+ *   of another (see nfs_lookup())
  */
 
 #include <linux/config.h>
 
 #define NFSDBG_FACILITY                NFSDBG_VFS
 
-/* Maximum number of readahead requests
- * FIXME: this should really be a sysctl so that users may tune it to suit
- *        their needs. People that do NFS over a slow network, might for
- *        instance want to reduce it to something closer to 1 for improved
- *        interactive response.
- */
-#define NFS_MAX_READAHEAD      (RPC_DEF_SLOT_TABLE - 1)
-
 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 *);
 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
-static int nfs_clone_nfs_sb(struct file_system_type *fs_type,
+static int nfs_xdev_get_sb(struct file_system_type *fs_type,
                int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static void nfs_kill_super(struct super_block *);
 
        .fs_flags       = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
-struct file_system_type clone_nfs_fs_type = {
+struct file_system_type nfs_xdev_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "nfs",
-       .get_sb         = nfs_clone_nfs_sb,
+       .get_sb         = nfs_xdev_get_sb,
        .kill_sb        = nfs_kill_super,
        .fs_flags       = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 #ifdef CONFIG_NFS_V4
 static int nfs4_get_sb(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
-static int nfs_clone_nfs4_sb(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
-static int nfs_referral_nfs4_sb(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
+static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
+       int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
+static int nfs4_referral_get_sb(struct file_system_type *fs_type,
+       int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static void nfs4_kill_super(struct super_block *sb);
 
 static struct file_system_type nfs4_fs_type = {
        .fs_flags       = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
-struct file_system_type clone_nfs4_fs_type = {
+struct file_system_type nfs4_xdev_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "nfs4",
-       .get_sb         = nfs_clone_nfs4_sb,
+       .get_sb         = nfs4_xdev_get_sb,
        .kill_sb        = nfs4_kill_super,
        .fs_flags       = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
-struct file_system_type nfs_referral_nfs4_fs_type = {
+struct file_system_type nfs4_referral_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "nfs4",
-       .get_sb         = nfs_referral_nfs4_sb,
+       .get_sb         = nfs4_referral_get_sb,
        .kill_sb        = nfs4_kill_super,
        .fs_flags       = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
        nfs_show_mount_options(m, nfss, 0);
 
        seq_puts(m, ",addr=");
-       seq_escape(m, nfss->hostname, " \t\n\\");
+       seq_escape(m, nfss->nfs_client->cl_hostname, " \t\n\\");
 
        return 0;
 }
 
 /*
  * Begin unmount by attempting to remove all automounted mountpoints we added
- * in response to traversals
+ * in response to xdev traversals and referrals
  */
 static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
 {
-       struct nfs_server *server;
-       struct rpc_clnt *rpc;
-
        shrink_submounts(vfsmnt, &nfs_automount_list);
-       if (!(flags & MNT_FORCE))
-               return;
-       /* -EIO all pending I/O */
-       server = NFS_SB(vfsmnt->mnt_sb);
-       rpc = server->client;
-       if (!IS_ERR(rpc))
-               rpc_killall_tasks(rpc);
-       rpc = server->client_acl;
-       if (!IS_ERR(rpc))
-               rpc_killall_tasks(rpc);
 }
 
 /*
- * Obtain the root inode of the file system.
+ * Validate the NFS2/NFS3 mount data
+ * - fills in the mount root filehandle
  */
-static struct inode *
-nfs_get_root(struct super_block *sb, struct nfs_fh *rootfh, struct nfs_fsinfo *fsinfo)
+static int nfs_validate_mount_data(struct nfs_mount_data *data,
+                                  struct nfs_fh *mntfh)
 {
-       struct nfs_server       *server = NFS_SB(sb);
-       int                     error;
-
-       error = server->nfs_client->rpc_ops->getroot(server, rootfh, fsinfo);
-       if (error < 0) {
-               dprintk("nfs_get_root: getattr error = %d\n", -error);
-               return ERR_PTR(error);
+       if (data == NULL) {
+               dprintk("%s: missing data argument\n", __FUNCTION__);
+               return -EINVAL;
        }
 
-       server->fsid = fsinfo->fattr->fsid;
-       return nfs_fhget(sb, rootfh, fsinfo->fattr);
-}
-
-/*
- * Do NFS version-independent mount processing, and sanity checking
- */
-static int
-nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
-{
-       struct nfs_server       *server;
-       struct inode            *root_inode;
-       struct nfs_fattr        fattr;
-       struct nfs_fsinfo       fsinfo = {
-                                       .fattr = &fattr,
-                               };
-       struct nfs_pathconf pathinfo = {
-                       .fattr = &fattr,
-       };
-       int no_root_error = 0;
-       unsigned long max_rpc_payload;
-
-       /* We probably want something more informative here */
-       snprintf(sb->s_id, sizeof(sb->s_id), "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
-
-       server = NFS_SB(sb);
-
-       sb->s_magic      = NFS_SUPER_MAGIC;
-
-       server->io_stats = nfs_alloc_iostats();
-       if (server->io_stats == NULL)
-               return -ENOMEM;
+       if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
+               dprintk("%s: bad mount version\n", __FUNCTION__);
+               return -EINVAL;
+       }
 
-       root_inode = nfs_get_root(sb, &server->fh, &fsinfo);
-       /* Did getting the root inode fail? */
-       if (IS_ERR(root_inode)) {
-               no_root_error = PTR_ERR(root_inode);
-               goto out_no_root;
+       switch (data->version) {
+               case 1:
+                       data->namlen = 0;
+               case 2:
+                       data->bsize  = 0;
+               case 3:
+                       if (data->flags & NFS_MOUNT_VER3) {
+                               dprintk("%s: mount structure version %d does not support NFSv3\n",
+                                               __FUNCTION__,
+                                               data->version);
+                               return -EINVAL;
+                       }
+                       data->root.size = NFS2_FHSIZE;
+                       memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
+               case 4:
+                       if (data->flags & NFS_MOUNT_SECFLAVOUR) {
+                               dprintk("%s: mount structure version %d does not support strong security\n",
+                                               __FUNCTION__,
+                                               data->version);
+                               return -EINVAL;
+                       }
+                       /* Fill in pseudoflavor for mount version < 5 */
+                       data->pseudoflavor = RPC_AUTH_UNIX;
+               case 5:
+                       memset(data->context, 0, sizeof(data->context));
        }
-       sb->s_root = d_alloc_root(root_inode);
-       if (!sb->s_root) {
-               no_root_error = -ENOMEM;
-               goto out_no_root;
+
+#ifndef CONFIG_NFS_V3
+       /* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
+       if (data->flags & NFS_MOUNT_VER3) {
+               dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
+               return -EPROTONOSUPPORT;
        }
-       sb->s_root->d_op = server->nfs_client->rpc_ops->dentry_ops;
-
-       /* mount time stamp, in seconds */
-       server->mount_time = jiffies;
-
-       /* Get some general file system info */
-       if (server->namelen == 0 &&
-           server->nfs_client->rpc_ops->pathconf(server, &server->fh, &pathinfo) >= 0)
-               server->namelen = pathinfo.max_namelen;
-       /* Work out a lot of parameters */
-       if (server->rsize == 0)
-               server->rsize = nfs_block_size(fsinfo.rtpref, NULL);
-       if (server->wsize == 0)
-               server->wsize = nfs_block_size(fsinfo.wtpref, NULL);
-
-       if (fsinfo.rtmax >= 512 && server->rsize > fsinfo.rtmax)
-               server->rsize = nfs_block_size(fsinfo.rtmax, NULL);
-       if (fsinfo.wtmax >= 512 && server->wsize > fsinfo.wtmax)
-               server->wsize = nfs_block_size(fsinfo.wtmax, NULL);
-
-       max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
-       if (server->rsize > max_rpc_payload)
-               server->rsize = max_rpc_payload;
-       if (server->rsize > NFS_MAX_FILE_IO_SIZE)
-               server->rsize = NFS_MAX_FILE_IO_SIZE;
-       server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
-       if (server->wsize > max_rpc_payload)
-               server->wsize = max_rpc_payload;
-       if (server->wsize > NFS_MAX_FILE_IO_SIZE)
-               server->wsize = NFS_MAX_FILE_IO_SIZE;
-       server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+#endif /* CONFIG_NFS_V3 */
 
-       if (sb->s_blocksize == 0)
-               sb->s_blocksize = nfs_block_bits(server->wsize,
-                                                        &sb->s_blocksize_bits);
-       server->wtmult = nfs_block_bits(fsinfo.wtmult, NULL);
-
-       server->dtsize = nfs_block_size(fsinfo.dtpref, NULL);
-       if (server->dtsize > PAGE_CACHE_SIZE)
-               server->dtsize = PAGE_CACHE_SIZE;
-       if (server->dtsize > server->rsize)
-               server->dtsize = server->rsize;
-
-       if (server->flags & NFS_MOUNT_NOAC) {
-               server->acregmin = server->acregmax = 0;
-               server->acdirmin = server->acdirmax = 0;
-               sb->s_flags |= MS_SYNCHRONOUS;
+       /* We now require that the mount process passes the remote address */
+       if (data->addr.sin_addr.s_addr == INADDR_ANY) {
+               dprintk("%s: mount program didn't pass remote address!\n",
+                       __FUNCTION__);
+               return -EINVAL;
        }
-       server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
 
-       nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
+       /* Prepare the root filehandle */
+       if (data->flags & NFS_MOUNT_VER3)
+               mntfh->size = data->root.size;
+       else
+               mntfh->size = NFS2_FHSIZE;
 
-       server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0;
-       server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0;
+       if (mntfh->size > sizeof(mntfh->data)) {
+               dprintk("%s: invalid root filehandle\n", __FUNCTION__);
+               return -EINVAL;
+       }
+
+       memcpy(mntfh->data, data->root.data, mntfh->size);
+       if (mntfh->size < sizeof(mntfh->data))
+               memset(mntfh->data + mntfh->size, 0,
+                      sizeof(mntfh->data) - mntfh->size);
 
-       /* We're airborne Set socket buffersize */
-       rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
        return 0;
-       /* Yargs. It didn't work out. */
-out_no_root:
-       dprintk("nfs_sb_init: get root inode failed: errno %d\n", -no_root_error);
-       if (!IS_ERR(root_inode))
-               iput(root_inode);
-       return no_root_error;
 }
 
 /*
- * Create an RPC client handle.
+ * Initialise the common bits of the superblock
  */
-static struct rpc_clnt *
-nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
+static inline void nfs_initialise_sb(struct super_block *sb)
 {
-       struct nfs_client       *clp;
-       struct rpc_clnt         *clnt;
-       int                     proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
-       int                     nfsversion = 2;
-       int                     err;
-
-#ifdef CONFIG_NFS_V3
-       if (server->flags & NFS_MOUNT_VER3)
-               nfsversion = 3;
-#endif
-
-       clp = nfs_get_client(server->hostname, &server->addr, nfsversion);
-       if (!clp) {
-               dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
-               return ERR_PTR(PTR_ERR(clp));
-       }
-
-       if (clp->cl_cons_state == NFS_CS_INITING) {
-               /* Check NFS protocol revision and initialize RPC op
-                * vector and file handle pool. */
-#ifdef CONFIG_NFS_V3
-               if (nfsversion == 3) {
-                       clp->rpc_ops = &nfs_v3_clientops;
-                       server->caps |= NFS_CAP_READDIRPLUS;
-               } else {
-                       clp->rpc_ops = &nfs_v2_clientops;
-               }
-#else
-               clp->rpc_ops = &nfs_v2_clientops;
-#endif
-
-               /* create transport and client */
-               err = nfs_create_rpc_client(clp, proto, data->timeo,
-                                           data->retrans, RPC_AUTH_UNIX);
-               if (err < 0)
-                       goto client_init_error;
-
-               nfs_mark_client_ready(clp, 0);
-       }
+       struct nfs_server *server = NFS_SB(sb);
 
-       /* create an nfs_server-specific client */
-       clnt = rpc_clone_client(clp->cl_rpcclient);
-       if (IS_ERR(clnt)) {
-               dprintk("%s: couldn't create rpc_client!\n", __FUNCTION__);
-               nfs_put_client(clp);
-               return ERR_PTR(PTR_ERR(clnt));
-       }
+       sb->s_magic = NFS_SUPER_MAGIC;
 
-       if (data->pseudoflavor != clp->cl_rpcclient->cl_auth->au_flavor) {
-               struct rpc_auth *auth;
+       /* We probably want something more informative here */
+       snprintf(sb->s_id, sizeof(sb->s_id),
+                "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
 
-               auth = rpcauth_create(data->pseudoflavor, server->client);
-               if (IS_ERR(auth)) {
-                       dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
-                       return ERR_PTR(PTR_ERR(auth));
-               }
-       }
+       if (sb->s_blocksize == 0)
+               sb->s_blocksize = nfs_block_bits(server->wsize,
+                                                &sb->s_blocksize_bits);
 
-       server->nfs_client = clp;
-       return clnt;
+       if (server->flags & NFS_MOUNT_NOAC)
+               sb->s_flags |= MS_SYNCHRONOUS;
 
-client_init_error:
-       nfs_mark_client_ready(clp, err);
-       nfs_put_client(clp);
-       return ERR_PTR(err);
+       nfs_super_set_maxbytes(sb, server->maxfilesize);
 }
 
 /*
- * Clone a server record
+ * Finish setting up an NFS2/3 superblock
  */
-static struct nfs_server *nfs_clone_server(struct super_block *sb, struct nfs_clone_mount *data)
+static void nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data)
 {
        struct nfs_server *server = NFS_SB(sb);
-       struct nfs_server *parent = NFS_SB(data->sb);
-       struct inode *root_inode;
-       struct nfs_fsinfo fsinfo;
-       void *err = ERR_PTR(-ENOMEM);
-
-       sb->s_op = data->sb->s_op;
-       sb->s_blocksize = data->sb->s_blocksize;
-       sb->s_blocksize_bits = data->sb->s_blocksize_bits;
-       sb->s_maxbytes = data->sb->s_maxbytes;
-
-       server->client_acl = ERR_PTR(-EINVAL);
-       server->io_stats = nfs_alloc_iostats();
-       if (server->io_stats == NULL)
-               goto out;
-
-       server->client = rpc_clone_client(parent->client);
-       if (IS_ERR((err = server->client)))
-               goto out;
-
-       if (!IS_ERR(parent->client_acl)) {
-               server->client_acl = rpc_clone_client(parent->client_acl);
-               if (IS_ERR((err = server->client_acl)))
-                       goto out;
-       }
-       root_inode = nfs_fhget(sb, data->fh, data->fattr);
-       if (!root_inode)
-               goto out;
-       sb->s_root = d_alloc_root(root_inode);
-       if (!sb->s_root)
-               goto out_put_root;
-       fsinfo.fattr = data->fattr;
-       if (NFS_PROTO(root_inode)->fsinfo(server, data->fh, &fsinfo) == 0)
-               nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
-       sb->s_root->d_op = server->nfs_client->rpc_ops->dentry_ops;
-       sb->s_flags |= MS_ACTIVE;
-       return server;
-out_put_root:
-       iput(root_inode);
-out:
-       return err;
-}
-
-/*
- * Copy an existing superblock and attach revised data
- */
-static int nfs_clone_generic_sb(struct nfs_clone_mount *data,
-               struct super_block *(*fill_sb)(struct nfs_server *, struct nfs_clone_mount *),
-               struct nfs_server *(*fill_server)(struct super_block *, struct nfs_clone_mount *),
-               struct vfsmount *mnt)
-{
-       struct nfs_server *server;
-       struct nfs_server *parent = NFS_SB(data->sb);
-       struct super_block *sb = ERR_PTR(-EINVAL);
-       char *hostname;
-       int error = -ENOMEM;
-       int len;
-
-       server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
-       if (server == NULL)
-               goto out_err;
-       memcpy(server, parent, sizeof(*server));
-       atomic_inc(&server->nfs_client->cl_count);
-       hostname = (data->hostname != NULL) ? data->hostname : parent->hostname;
-       len = strlen(hostname) + 1;
-       server->hostname = kmalloc(len, GFP_KERNEL);
-       if (server->hostname == NULL)
-               goto free_server;
-       memcpy(server->hostname, hostname, len);
-
-       sb = fill_sb(server, data);
-       if (IS_ERR(sb)) {
-               error = PTR_ERR(sb);
-               goto free_hostname;
-       }
 
-       if (sb->s_root)
-               goto out_share;
+       sb->s_blocksize_bits = 0;
+       sb->s_blocksize = 0;
+       if (data->bsize)
+               sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
 
-       server = fill_server(sb, data);
-       if (IS_ERR(server)) {
-               error = PTR_ERR(server);
-               goto out_deactivate;
+       if (server->flags & NFS_MOUNT_VER3) {
+               /* The VFS shouldn't apply the umask to mode bits. We will do
+                * so ourselves when necessary.
+                */
+               sb->s_flags |= MS_POSIXACL;
+               sb->s_time_gran = 1;
        }
-       return simple_set_mnt(mnt, sb);
-out_deactivate:
-       up_write(&sb->s_umount);
-       deactivate_super(sb);
-       return error;
-out_share:
-       kfree(server->hostname);
-       nfs_put_client(server->nfs_client);
-       kfree(server);
-       return simple_set_mnt(mnt, sb);
-free_hostname:
-       kfree(server->hostname);
-free_server:
-       nfs_put_client(server->nfs_client);
-       kfree(server);
-out_err:
-       return error;
+
+       sb->s_op = &nfs_sops;
+       nfs_initialise_sb(sb);
 }
 
 /*
- * Set up an NFS2/3 superblock
- *
- * The way this works is that the mount process passes a structure
- * in the data argument which contains the server's IP address
- * and the root file handle obtained from the server's mount
- * daemon. We stash these away in the private superblock fields.
+ * Finish setting up a cloned NFS2/3 superblock
  */
-static int
-nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data, int silent)
+static void nfs_clone_super(struct super_block *sb,
+                           const struct super_block *old_sb)
 {
-       struct nfs_server       *server;
-       rpc_authflavor_t        authflavor;
+       struct nfs_server *server = NFS_SB(sb);
+
+       sb->s_blocksize_bits = old_sb->s_blocksize_bits;
+       sb->s_blocksize = old_sb->s_blocksize;
+       sb->s_maxbytes = old_sb->s_maxbytes;
 
-       server           = NFS_SB(sb);
-       sb->s_blocksize_bits = 0;
-       sb->s_blocksize = 0;
-       if (data->bsize)
-               sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
-       if (data->rsize)
-               server->rsize = nfs_block_size(data->rsize, NULL);
-       if (data->wsize)
-               server->wsize = nfs_block_size(data->wsize, NULL);
-       server->flags    = data->flags & NFS_MOUNT_FLAGMASK;
-
-       server->acregmin = data->acregmin*HZ;
-       server->acregmax = data->acregmax*HZ;
-       server->acdirmin = data->acdirmin*HZ;
-       server->acdirmax = data->acdirmax*HZ;
-
-       /* Start lockd here, before we might error out */
-       if (!(server->flags & NFS_MOUNT_NONLM))
-               lockd_up();
-
-       server->namelen  = data->namlen;
-       server->hostname = kmalloc(strlen(data->hostname) + 1, GFP_KERNEL);
-       if (!server->hostname)
-               return -ENOMEM;
-       strcpy(server->hostname, data->hostname);
-
-       /* Fill in pseudoflavor for mount version < 5 */
-       if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
-               data->pseudoflavor = RPC_AUTH_UNIX;
-       authflavor = data->pseudoflavor;        /* save for sb_init() */
-       /* XXX maybe we want to add a server->pseudoflavor field */
-
-       /* Create RPC client handles */
-       server->client = nfs_create_client(server, data);
-       if (IS_ERR(server->client))
-               return PTR_ERR(server->client);
-
-       /* RFC 2623, sec 2.3.2 */
        if (server->flags & NFS_MOUNT_VER3) {
-#ifdef CONFIG_NFS_V3_ACL
-               if (!(server->flags & NFS_MOUNT_NOACL)) {
-                       server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
-                       /* No errors! Assume that Sun nfsacls are supported */
-                       if (!IS_ERR(server->client_acl))
-                               server->caps |= NFS_CAP_ACLS;
-               }
-#else
-               server->flags &= ~NFS_MOUNT_NOACL;
-#endif /* CONFIG_NFS_V3_ACL */
-               /*
-                * The VFS shouldn't apply the umask to mode bits. We will
-                * do so ourselves when necessary.
+               /* The VFS shouldn't apply the umask to mode bits. We will do
+                * so ourselves when necessary.
                 */
                sb->s_flags |= MS_POSIXACL;
-               if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
-                       server->namelen = NFS3_MAXNAMLEN;
                sb->s_time_gran = 1;
-       } else {
-               if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
-                       server->namelen = NFS2_MAXNAMLEN;
        }
 
-       sb->s_op = &nfs_sops;
-       return nfs_sb_init(sb, authflavor);
+       sb->s_op = old_sb->s_op;
+       nfs_initialise_sb(sb);
 }
 
-static int nfs_set_super(struct super_block *s, void *data)
+static int nfs_set_super(struct super_block *s, void *_server)
 {
-       s->s_fs_info = data;
-       return set_anon_super(s, data);
+       struct nfs_server *server = _server;
+       int ret;
+
+       s->s_fs_info = server;
+       ret = set_anon_super(s, server);
+       if (ret == 0)
+               server->s_dev = s->s_dev;
+       return ret;
 }
 
 static int nfs_compare_super(struct super_block *sb, void *data)
 {
-       struct nfs_server *server = data;
-       struct nfs_server *old = NFS_SB(sb);
+       struct nfs_server *server = data, *old = NFS_SB(sb);
 
-       if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
+       if (old->nfs_client != server->nfs_client)
                return 0;
-       if (old->addr.sin_port != server->addr.sin_port)
+       if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
                return 0;
-       return !nfs_compare_fh(&old->fh, &server->fh);
+       return 1;
 }
 
 static int nfs_get_sb(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
 {
-       int error;
        struct nfs_server *server = NULL;
        struct super_block *s;
-       struct nfs_fh *root;
+       struct nfs_fh mntfh;
        struct nfs_mount_data *data = raw_data;
+       struct dentry *mntroot;
+       int error;
 
-       error = -EINVAL;
-       if (data == NULL) {
-               dprintk("%s: missing data argument\n", __FUNCTION__);
-               goto out_err_noserver;
-       }
-       if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
-               dprintk("%s: bad mount version\n", __FUNCTION__);
-               goto out_err_noserver;
-       }
-       switch (data->version) {
-               case 1:
-                       data->namlen = 0;
-               case 2:
-                       data->bsize  = 0;
-               case 3:
-                       if (data->flags & NFS_MOUNT_VER3) {
-                               dprintk("%s: mount structure version %d does not support NFSv3\n",
-                                               __FUNCTION__,
-                                               data->version);
-                               goto out_err_noserver;
-                       }
-                       data->root.size = NFS2_FHSIZE;
-                       memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
-               case 4:
-                       if (data->flags & NFS_MOUNT_SECFLAVOUR) {
-                               dprintk("%s: mount structure version %d does not support strong security\n",
-                                               __FUNCTION__,
-                                               data->version);
-                               goto out_err_noserver;
-                       }
-               case 5:
-                       memset(data->context, 0, sizeof(data->context));
-       }
-#ifndef CONFIG_NFS_V3
-       /* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
-       error = -EPROTONOSUPPORT;
-       if (data->flags & NFS_MOUNT_VER3) {
-               dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
-               goto out_err_noserver;
-       }
-#endif /* CONFIG_NFS_V3 */
+       /* Validate the mount data */
+       error = nfs_validate_mount_data(data, &mntfh);
+       if (error < 0)
+               return error;
 
-       error = -ENOMEM;
-       server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
-       if (!server)
+       /* Get a volume representation */
+       server = nfs_create_server(data, &mntfh);
+       if (IS_ERR(server)) {
+               error = PTR_ERR(server);
                goto out_err_noserver;
-       /* Zero out the NFS state stuff */
-       init_nfsv4_state(server);
-       server->client = server->client_acl = ERR_PTR(-EINVAL);
-
-       root = &server->fh;
-       if (data->flags & NFS_MOUNT_VER3)
-               root->size = data->root.size;
-       else
-               root->size = NFS2_FHSIZE;
-       error = -EINVAL;
-       if (root->size > sizeof(root->data)) {
-               dprintk("%s: invalid root filehandle\n", __FUNCTION__);
-               goto out_err;
-       }
-       memcpy(root->data, data->root.data, root->size);
-
-       /* We now require that the mount process passes the remote address */
-       memcpy(&server->addr, &data->addr, sizeof(server->addr));
-       if (server->addr.sin_addr.s_addr == INADDR_ANY) {
-               dprintk("%s: mount program didn't pass remote address!\n",
-                               __FUNCTION__);
-               goto out_err;
        }
 
+       /* 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);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
-               goto out_err;
+               goto out_err_nosb;
        }
 
-       if (s->s_root)
-               goto out_share;
+       if (s->s_fs_info != server) {
+               nfs_free_server(server);
+               server = NULL;
+       }
 
-       s->s_flags = flags;
+       if (!s->s_root) {
+               /* initial superblock/root creation */
+               s->s_flags = flags;
+               nfs_fill_super(s, data);
+       }
 
-       error = nfs_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
-       if (error) {
-               up_write(&s->s_umount);
-               deactivate_super(s);
-               return error;
+       mntroot = nfs_get_root(s, &mntfh);
+       if (IS_ERR(mntroot)) {
+               error = PTR_ERR(mntroot);
+               goto error_splat_super;
        }
-       s->s_flags |= MS_ACTIVE;
-       return simple_set_mnt(mnt, s);
 
-out_share:
-       kfree(server);
-       return simple_set_mnt(mnt, s);
+       s->s_flags |= MS_ACTIVE;
+       mnt->mnt_sb = s;
+       mnt->mnt_root = mntroot;
+       return 0;
 
-out_err:
-       kfree(server);
+out_err_nosb:
+       nfs_free_server(server);
 out_err_noserver:
        return error;
+
+error_splat_super:
+       up_write(&s->s_umount);
+       deactivate_super(s);
+       return error;
 }
 
+/*
+ * Destroy an NFS2/3 superblock
+ */
 static void nfs_kill_super(struct super_block *s)
 {
        struct nfs_server *server = NFS_SB(s);
 
        kill_anon_super(s);
-
-       if (!IS_ERR(server->client))
-               rpc_shutdown_client(server->client);
-       if (!IS_ERR(server->client_acl))
-               rpc_shutdown_client(server->client_acl);
-
-       if (!(server->flags & NFS_MOUNT_NONLM))
-               lockd_down();   /* release rpc.lockd */
-
-       nfs_free_iostats(server->io_stats);
-       kfree(server->hostname);
-       nfs_put_client(server->nfs_client);
-       kfree(server);
-       nfs_release_automount_timer();
+       nfs_free_server(server);
 }
 
-static struct super_block *nfs_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
-{
-       struct super_block *sb;
-
-       server->fsid = data->fattr->fsid;
-       nfs_copy_fh(&server->fh, data->fh);
-       sb = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
-       if (!IS_ERR(sb) && sb->s_root == NULL && !(server->flags & NFS_MOUNT_NONLM))
-               lockd_up();
-       return sb;
-}
-
-static int nfs_clone_nfs_sb(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
+/*
+ * Clone an NFS2/3 server record on xdev traversal (FSID-change)
+ */
+static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
+                          const char *dev_name, void *raw_data,
+                          struct vfsmount *mnt)
 {
        struct nfs_clone_mount *data = raw_data;
-       return nfs_clone_generic_sb(data, nfs_clone_sb, nfs_clone_server, mnt);
-}
+       struct super_block *s;
+       struct nfs_server *server;
+       struct dentry *mntroot;
+       int error;
 
-#ifdef CONFIG_NFS_V4
-static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
-       int timeo, int retrans, int proto, rpc_authflavor_t flavor)
-{
-       struct nfs_client *clp;
-       struct rpc_clnt *clnt = NULL;
-       int err = -EIO;
-
-       clp = nfs_get_client(server->hostname, &server->addr, 4);
-       if (!clp) {
-               dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
-               return ERR_PTR(err);
-       }
+       dprintk("--> nfs_xdev_get_sb()\n");
 
-       /* Now create transport and client */
-       if (clp->cl_cons_state == NFS_CS_INITING) {
-               clp->rpc_ops = &nfs_v4_clientops;
+       /* create a new volume representation */
+       server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
+       if (IS_ERR(server)) {
+               error = PTR_ERR(server);
+               goto out_err_noserver;
+       }
 
-               err = nfs_create_rpc_client(clp, proto, timeo, retrans, flavor);
-               if (err < 0)
-                       goto client_init_error;
+       /* 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);
+       if (IS_ERR(s)) {
+               error = PTR_ERR(s);
+               goto out_err_nosb;
+       }
 
-               memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
-               err = nfs_idmap_new(clp);
-               if (err < 0) {
-                       dprintk("%s: failed to create idmapper.\n",
-                               __FUNCTION__);
-                       goto client_init_error;
-               }
-               __set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
-               nfs_mark_client_ready(clp, 0);
+       if (s->s_fs_info != server) {
+               nfs_free_server(server);
+               server = NULL;
        }
 
-       clnt = rpc_clone_client(clp->cl_rpcclient);
+       if (!s->s_root) {
+               /* initial superblock/root creation */
+               s->s_flags = flags;
+               nfs_clone_super(s, data->sb);
+       }
 
-       if (IS_ERR(clnt)) {
-               dprintk("%s: cannot create RPC client. Error = %d\n",
-                               __FUNCTION__, err);
-               return clnt;
+       mntroot = nfs_get_root(s, data->fh);
+       if (IS_ERR(mntroot)) {
+               error = PTR_ERR(mntroot);
+               goto error_splat_super;
        }
 
-       if (clnt->cl_auth->au_flavor != flavor) {
-               struct rpc_auth *auth;
+       s->s_flags |= MS_ACTIVE;
+       mnt->mnt_sb = s;
+       mnt->mnt_root = mntroot;
 
-               auth = rpcauth_create(flavor, clnt);
-               if (IS_ERR(auth)) {
-                       dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
-                       return (struct rpc_clnt *)auth;
-               }
-       }
+       dprintk("<-- nfs_xdev_get_sb() = 0\n");
+       return 0;
 
-       server->nfs_client = clp;
-       down_write(&clp->cl_sem);
-       list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
-       up_write(&clp->cl_sem);
-       return clnt;
+out_err_nosb:
+       nfs_free_server(server);
+out_err_noserver:
+       dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
+       return error;
 
-client_init_error:
-       nfs_mark_client_ready(clp, err);
-       nfs_put_client(clp);
-       return ERR_PTR(err);
+error_splat_super:
+       up_write(&s->s_umount);
+       deactivate_super(s);
+       dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
+       return error;
 }
 
+#ifdef CONFIG_NFS_V4
+
 /*
- * Set up an NFS4 superblock
+ * Finish setting up a cloned NFS4 superblock
  */
-static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data, int silent)
+static void nfs4_clone_super(struct super_block *sb,
+                           const struct super_block *old_sb)
 {
-       struct nfs_server *server;
-       rpc_authflavor_t authflavour;
-       int err = -EIO;
-
-       sb->s_blocksize_bits = 0;
-       sb->s_blocksize = 0;
-       server = NFS_SB(sb);
-       if (data->rsize != 0)
-               server->rsize = nfs_block_size(data->rsize, NULL);
-       if (data->wsize != 0)
-               server->wsize = nfs_block_size(data->wsize, NULL);
-       server->flags = data->flags & NFS_MOUNT_FLAGMASK;
-       server->caps = NFS_CAP_ATOMIC_OPEN;
-
-       server->acregmin = data->acregmin*HZ;
-       server->acregmax = data->acregmax*HZ;
-       server->acdirmin = data->acdirmin*HZ;
-       server->acdirmax = data->acdirmax*HZ;
-
-       /* Now create transport and client */
-       authflavour = RPC_AUTH_UNIX;
-       if (data->auth_flavourlen != 0) {
-               if (data->auth_flavourlen != 1) {
-                       dprintk("%s: Invalid number of RPC auth flavours %d.\n",
-                                       __FUNCTION__, data->auth_flavourlen);
-                       err = -EINVAL;
-                       goto out_fail;
-               }
-               if (copy_from_user(&authflavour, data->auth_flavours, sizeof(authflavour))) {
-                       err = -EFAULT;
-                       goto out_fail;
-               }
-       }
-
-       server->client = nfs4_create_client(server, data->timeo, data->retrans,
-                                           data->proto, authflavour);
-       if (IS_ERR(server->client)) {
-               err = PTR_ERR(server->client);
-                       dprintk("%s: cannot create RPC client. Error = %d\n",
-                                       __FUNCTION__, err);
-                       goto out_fail;
-       }
-
+       sb->s_blocksize_bits = old_sb->s_blocksize_bits;
+       sb->s_blocksize = old_sb->s_blocksize;
+       sb->s_maxbytes = old_sb->s_maxbytes;
        sb->s_time_gran = 1;
-
-       sb->s_op = &nfs4_sops;
-       err = nfs_sb_init(sb, authflavour);
-
- out_fail:
-       return err;
+       sb->s_op = old_sb->s_op;
+       nfs_initialise_sb(sb);
 }
 
-static int nfs4_compare_super(struct super_block *sb, void *data)
+/*
+ * Set up an NFS4 superblock
+ */
+static void nfs4_fill_super(struct super_block *sb)
 {
-       struct nfs_server *server = data;
-       struct nfs_server *old = NFS_SB(sb);
-
-       if (strcmp(server->hostname, old->hostname) != 0)
-               return 0;
-       if (strcmp(server->mnt_path, old->mnt_path) != 0)
-               return 0;
-       return 1;
+       sb->s_time_gran = 1;
+       sb->s_op = &nfs4_sops;
+       nfs_initialise_sb(sb);
 }
 
-static void *
-nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
+static void *nfs_copy_user_string(char *dst, struct nfs_string *src, int maxlen)
 {
        void *p = NULL;
 
        return dst;
 }
 
+/*
+ * Get the superblock for an NFS4 mountpoint
+ */
 static int nfs4_get_sb(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
 {
-       int error;
-       struct nfs_server *server;
-       struct super_block *s;
        struct nfs4_mount_data *data = raw_data;
+       struct super_block *s;
+       struct nfs_server *server;
+       struct sockaddr_in addr;
+       rpc_authflavor_t authflavour;
+       struct nfs_fh mntfh;
+       struct dentry *mntroot;
+       char *mntpath = NULL, *hostname = NULL, ip_addr[16];
        void *p;
+       int error;
 
        if (data == NULL) {
                dprintk("%s: missing data argument\n", __FUNCTION__);
                return -EINVAL;
        }
 
-       server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
-       if (!server)
-               return -ENOMEM;
-       /* Zero out the NFS state stuff */
-       init_nfsv4_state(server);
-       server->client = server->client_acl = ERR_PTR(-EINVAL);
+       /* We now require that the mount process passes the remote address */
+       if (data->host_addrlen != sizeof(addr))
+               return -EINVAL;
+
+       if (copy_from_user(&addr, data->host_addr, sizeof(addr)))
+               return -EFAULT;
+
+       if (addr.sin_family != AF_INET ||
+           addr.sin_addr.s_addr == INADDR_ANY
+           ) {
+               dprintk("%s: mount program didn't pass remote IP address!\n",
+                               __FUNCTION__);
+               return -EINVAL;
+       }
+
+       /* Grab the authentication type */
+       authflavour = RPC_AUTH_UNIX;
+       if (data->auth_flavourlen != 0) {
+               if (data->auth_flavourlen != 1) {
+                       dprintk("%s: Invalid number of RPC auth flavours %d.\n",
+                                       __FUNCTION__, data->auth_flavourlen);
+                       error = -EINVAL;
+                       goto out_err_noserver;
+               }
+
+               if (copy_from_user(&authflavour, data->auth_flavours,
+                                  sizeof(authflavour))) {
+                       error = -EFAULT;
+                       goto out_err_noserver;
+               }
+       }
 
        p = nfs_copy_user_string(NULL, &data->hostname, 256);
        if (IS_ERR(p))
                goto out_err;
-       server->hostname = p;
+       hostname = p;
 
        p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
        if (IS_ERR(p))
                goto out_err;
-       server->mnt_path = p;
+       mntpath = p;
 
-       p = nfs_copy_user_string(server->ip_addr, &data->client_addr,
-                       sizeof(server->ip_addr) - 1);
+       dprintk("MNTPATH: %s\n", mntpath);
+
+       p = nfs_copy_user_string(ip_addr, &data->client_addr,
+                                sizeof(ip_addr) - 1);
        if (IS_ERR(p))
                goto out_err;
 
-       /* We now require that the mount process passes the remote address */
-       if (data->host_addrlen != sizeof(server->addr)) {
-               error = -EINVAL;
-               goto out_free;
-       }
-       if (copy_from_user(&server->addr, data->host_addr, sizeof(server->addr))) {
-               error = -EFAULT;
-               goto out_free;
-       }
-       if (server->addr.sin_family != AF_INET ||
-           server->addr.sin_addr.s_addr == INADDR_ANY) {
-               dprintk("%s: mount program didn't pass remote IP address!\n",
-                               __FUNCTION__);
-               error = -EINVAL;
-               goto out_free;
+       /* Get a volume representation */
+       server = nfs4_create_server(data, hostname, &addr, mntpath, ip_addr,
+                                   authflavour, &mntfh);
+       if (IS_ERR(server)) {
+               error = PTR_ERR(server);
+               goto out_err_noserver;
        }
 
-       s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
+       /* 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);
        if (IS_ERR(s)) {
                error = PTR_ERR(s);
                goto out_free;
        }
 
-       if (s->s_root) {
-               kfree(server->mnt_path);
-               kfree(server->hostname);
-               kfree(server);
-               return simple_set_mnt(mnt, s);
-       }
+       if (!s->s_root) {
+               /* initial superblock/root creation */
+               s->s_flags = flags;
 
-       s->s_flags = flags;
+               nfs4_fill_super(s);
+       } else {
+               nfs_free_server(server);
+       }
 
-       error = nfs4_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
-       if (error) {
-               up_write(&s->s_umount);
-               deactivate_super(s);
-               return error;
+       mntroot = nfs4_get_root(s, &mntfh);
+       if (IS_ERR(mntroot)) {
+               error = PTR_ERR(mntroot);
+               goto error_splat_super;
        }
+
        s->s_flags |= MS_ACTIVE;
-       return simple_set_mnt(mnt, s);
+       mnt->mnt_sb = s;
+       mnt->mnt_root = mntroot;
+       kfree(mntpath);
+       kfree(hostname);
+       return 0;
+
 out_err:
        error = PTR_ERR(p);
+       goto out_err_noserver;
+
 out_free:
-       kfree(server->mnt_path);
-       kfree(server->hostname);
-       kfree(server);
+       nfs_free_server(server);
+out_err_noserver:
+       kfree(mntpath);
+       kfree(hostname);
        return error;
+
+error_splat_super:
+       up_write(&s->s_umount);
+       deactivate_super(s);
+       goto out_err_noserver;
 }
 
 static void nfs4_kill_super(struct super_block *sb)
        kill_anon_super(sb);
 
        nfs4_renewd_prepare_shutdown(server);
-
-       if (server->client != NULL && !IS_ERR(server->client))
-               rpc_shutdown_client(server->client);
-
-       destroy_nfsv4_state(server);
-
-       nfs_free_iostats(server->io_stats);
-       kfree(server->hostname);
-       kfree(server);
-       nfs_release_automount_timer();
+       nfs_free_server(server);
 }
 
 /*
- * Constructs the SERVER-side path
+ * Clone an NFS4 server record on xdev traversal (FSID-change)
  */
-static inline char *nfs4_dup_path(const struct dentry *dentry)
+static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
+                           const char *dev_name, void *raw_data,
+                           struct vfsmount *mnt)
 {
-       char *page = (char *) __get_free_page(GFP_USER);
-       char *path;
+       struct nfs_clone_mount *data = raw_data;
+       struct super_block *s;
+       struct nfs_server *server;
+       struct dentry *mntroot;
+       int error;
 
-       path = nfs4_path(dentry, page, PAGE_SIZE);
-       if (!IS_ERR(path)) {
-               int len = PAGE_SIZE + page - path;
-               char *tmp = path;
+       dprintk("--> nfs4_xdev_get_sb()\n");
 
-               path = kmalloc(len, GFP_KERNEL);
-               if (path)
-                       memcpy(path, tmp, len);
-               else
-                       path = ERR_PTR(-ENOMEM);
+       /* create a new volume representation */
+       server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
+       if (IS_ERR(server)) {
+               error = PTR_ERR(server);
+               goto out_err_noserver;
        }
-       free_page((unsigned long)page);
-       return path;
-}
 
-static struct super_block *nfs4_clone_sb(struct nfs_server *server, struct nfs_clone_mount *data)
-{
-       const struct dentry *dentry = data->dentry;
-       struct nfs_client *clp = server->nfs_client;
-       struct super_block *sb;
-
-       server->fsid = data->fattr->fsid;
-       nfs_copy_fh(&server->fh, data->fh);
-       server->mnt_path = nfs4_dup_path(dentry);
-       if (IS_ERR(server->mnt_path)) {
-               sb = (struct super_block *)server->mnt_path;
-               goto err;
+       /* 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);
+       if (IS_ERR(s)) {
+               error = PTR_ERR(s);
+               goto out_err_nosb;
        }
-       sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
-       if (IS_ERR(sb) || sb->s_root)
-               goto free_path;
-       nfs4_server_capabilities(server, &server->fh);
-
-       down_write(&clp->cl_sem);
-       list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
-       up_write(&clp->cl_sem);
-       return sb;
-free_path:
-       kfree(server->mnt_path);
-err:
-       server->mnt_path = NULL;
-       return sb;
-}
 
-static int nfs_clone_nfs4_sb(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
-{
-       struct nfs_clone_mount *data = raw_data;
-       return nfs_clone_generic_sb(data, nfs4_clone_sb, nfs_clone_server, mnt);
-}
+       if (s->s_fs_info != server) {
+               nfs_free_server(server);
+               server = NULL;
+       }
 
-static struct super_block *nfs4_referral_sb(struct nfs_server *server, struct nfs_clone_mount *data)
-{
-       struct super_block *sb = ERR_PTR(-ENOMEM);
-       int len;
-
-       len = strlen(data->mnt_path) + 1;
-       server->mnt_path = kmalloc(len, GFP_KERNEL);
-       if (server->mnt_path == NULL)
-               goto err;
-       memcpy(server->mnt_path, data->mnt_path, len);
-       memcpy(&server->addr, data->addr, sizeof(struct sockaddr_in));
-
-       sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
-       if (IS_ERR(sb) || sb->s_root)
-               goto free_path;
-       return sb;
-free_path:
-       kfree(server->mnt_path);
-err:
-       server->mnt_path = NULL;
-       return sb;
-}
+       if (!s->s_root) {
+               /* initial superblock/root creation */
+               s->s_flags = flags;
+               nfs4_clone_super(s, data->sb);
+       }
 
-static struct nfs_server *nfs4_referral_server(struct super_block *sb, struct nfs_clone_mount *data)
-{
-       struct nfs_server *server = NFS_SB(sb);
-       int proto, timeo, retrans;
-       void *err;
-
-       proto = IPPROTO_TCP;
-       /* Since we are following a referral and there may be alternatives,
-          set the timeouts and retries to low values */
-       timeo = 2;
-       retrans = 1;
-
-       nfs_put_client(server->nfs_client);
-       server->nfs_client = NULL;
-       server->client = nfs4_create_client(server, timeo, retrans, proto,
-                                           data->authflavor);
-       if (IS_ERR((err = server->client)))
-               goto out_err;
+       mntroot = nfs4_get_root(s, data->fh);
+       if (IS_ERR(mntroot)) {
+               error = PTR_ERR(mntroot);
+               goto error_splat_super;
+       }
 
-       sb->s_time_gran = 1;
-       sb->s_op = &nfs4_sops;
-       err = ERR_PTR(nfs_sb_init(sb, data->authflavor));
-       if (!IS_ERR(err))
-               return server;
-out_err:
-       return (struct nfs_server *)err;
+       s->s_flags |= MS_ACTIVE;
+       mnt->mnt_sb = s;
+       mnt->mnt_root = mntroot;
+
+       dprintk("<-- nfs4_xdev_get_sb() = 0\n");
+       return 0;
+
+out_err_nosb:
+       nfs_free_server(server);
+out_err_noserver:
+       dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
+       return error;
+
+error_splat_super:
+       up_write(&s->s_umount);
+       deactivate_super(s);
+       dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
+       return error;
 }
 
-static int nfs_referral_nfs4_sb(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
+/*
+ * Create an NFS4 server record on referral traversal
+ */
+static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
+                               const char *dev_name, void *raw_data,
+                               struct vfsmount *mnt)
 {
        struct nfs_clone_mount *data = raw_data;
-       return nfs_clone_generic_sb(data, nfs4_referral_sb, nfs4_referral_server, mnt);
+       struct super_block *s;
+       struct nfs_server *server;
+       struct dentry *mntroot;
+       struct nfs_fh mntfh;
+       int error;
+
+       dprintk("--> nfs4_referral_get_sb()\n");
+
+       /* create a new volume representation */
+       server = nfs4_create_referral_server(data, &mntfh);
+       if (IS_ERR(server)) {
+               error = PTR_ERR(server);
+               goto out_err_noserver;
+       }
+
+       /* 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);
+       if (IS_ERR(s)) {
+               error = PTR_ERR(s);
+               goto out_err_nosb;
+       }
+
+       if (s->s_fs_info != server) {
+               nfs_free_server(server);
+               server = NULL;
+       }
+
+       if (!s->s_root) {
+               /* initial superblock/root creation */
+               s->s_flags = flags;
+               nfs4_fill_super(s);
+       }
+
+       mntroot = nfs4_get_root(s, data->fh);
+       if (IS_ERR(mntroot)) {
+               error = PTR_ERR(mntroot);
+               goto error_splat_super;
+       }
+
+       s->s_flags |= MS_ACTIVE;
+       mnt->mnt_sb = s;
+       mnt->mnt_root = mntroot;
+
+       dprintk("<-- nfs4_referral_get_sb() = 0\n");
+       return 0;
+
+out_err_nosb:
+       nfs_free_server(server);
+out_err_noserver:
+       dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
+       return error;
+
+error_splat_super:
+       up_write(&s->s_umount);
+       deactivate_super(s);
+       dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
+       return error;
 }
 
-#endif
+#endif /* CONFIG_NFS_V4 */
 
                if (time_before(complain, jiffies)) {
                        dprintk("NFS: faulty NFS server %s:"
                                " (committed = %d) != (stable = %d)\n",
-                               NFS_SERVER(data->inode)->hostname,
+                               NFS_SERVER(data->inode)->nfs_client->cl_hostname,
                                resp->verf->committed, argp->stable);
                        complain = jiffies + 300 * HZ;
                }
 
        unsigned long           cl_lease_time;
        unsigned long           cl_last_renewal;
        struct work_struct      cl_renewd;
-       struct work_struct      cl_recoverd;
 
        struct rpc_wait_queue   cl_rpcwaitq;
 
  */
 struct nfs_server {
        struct nfs_client *     nfs_client;     /* shared client and NFS4 state */
+       struct list_head        client_link;    /* List of other nfs_server structs
+                                                * that share the same client
+                                                */
+       struct list_head        master_link;    /* link in master servers list */
        struct rpc_clnt *       client;         /* RPC client handle */
        struct rpc_clnt *       client_acl;     /* ACL RPC client handle */
        struct nfs_iostats *    io_stats;       /* I/O statistics */
        unsigned int            acdirmin;
        unsigned int            acdirmax;
        unsigned int            namelen;
-       char *                  hostname;       /* remote hostname */
-       struct nfs_fh           fh;
-       struct sockaddr_in      addr;
+
        struct nfs_fsid         fsid;
+       __u64                   maxfilesize;    /* maximum file size */
        unsigned long           mount_time;     /* when this fs was mounted */
+       dev_t                   s_dev;          /* superblock dev numbers */
+
 #ifdef CONFIG_NFS_V4
-       /* Our own IP address, as a null-terminated string.
-        * This is used to generate the clientid, and the callback address.
-        */
-       char                    ip_addr[16];
-       char *                  mnt_path;
-       struct list_head        nfs4_siblings;  /* List of other nfs_server structs
-                                                * that share the same clientid
-                                                */
        u32                     attr_bitmask[2];/* V4 bitmask representing the set
                                                   of attributes supported on this
                                                   filesystem */
                                                   that are supported on this
                                                   filesystem */
 #endif
+       void (*destroy)(struct nfs_server *);
 };
 
 /* Server capabilities */