From: David Howells <dhowe...@redhat.com>

Add filesystem context support to NFS, parsing the options in advance and
attaching the information to struct nfs_fs_context.  The highlights are:

 (*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context.  This
     structure represents NFS's superblock config.

 (*) Make use of the VFS's parsing support to split comma-separated lists

 (*) Pin the NFS protocol module in the nfs_fs_context.

 (*) Attach supplementary error information to fs_context.  This has the
     downside that these strings must be static and can't be formatted.

 (*) Remove the auxiliary file_system_type structs since the information
     necessary can be conveyed in the nfs_fs_context struct instead.

 (*) Root mounts are made by duplicating the config for the requested mount
     so as to have the same parameters.  Submounts pick up their parameters
     from the parent superblock.

[AV -- retrans is u32, not string]
[SM -- Renamed cfg to ctx in a few functions in an earlier patch]
[SM -- Moved fs_context mount option parsing to an earlier patch]
[SM -- Moved fs_context error logging to a later patch]
[SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()]
[SM -- Added is_remount_fc() helper]

Signed-off-by: David Howells <dhowe...@redhat.com>
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Scott Mayhew <smay...@redhat.com>
---
 fs/nfs/client.c         |  22 +-
 fs/nfs/fs_context.c     | 578 ++++++++++++++++++++++++----------------
 fs/nfs/fscache.c        |   2 +-
 fs/nfs/getroot.c        |  70 ++---
 fs/nfs/internal.h       | 100 +++----
 fs/nfs/namespace.c      | 134 ++++++----
 fs/nfs/nfs3_fs.h        |   2 +-
 fs/nfs/nfs3client.c     |   5 +-
 fs/nfs/nfs3proc.c       |   2 +-
 fs/nfs/nfs4_fs.h        |   9 +-
 fs/nfs/nfs4client.c     |  62 ++---
 fs/nfs/nfs4namespace.c  | 285 +++++++++++---------
 fs/nfs/nfs4proc.c       |   2 +-
 fs/nfs/nfs4super.c      | 164 ++++++------
 fs/nfs/proc.c           |   2 +-
 fs/nfs/super.c          | 312 ++++++----------------
 include/linux/nfs_xdr.h |   8 +-
 17 files changed, 897 insertions(+), 862 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 511d1d629786..a26e7d1d74bc 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -648,17 +648,17 @@ EXPORT_SYMBOL_GPL(nfs_init_client);
  * Create a version 2 or 3 client
  */
 static int nfs_init_server(struct nfs_server *server,
-                          const struct nfs_fs_context *ctx,
-                          struct nfs_subversion *nfs_mod)
+                          const struct fs_context *fc)
 {
+       const struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct rpc_timeout timeparms;
        struct nfs_client_initdata cl_init = {
                .hostname = ctx->nfs_server.hostname,
                .addr = (const struct sockaddr *)&ctx->nfs_server.address,
                .addrlen = ctx->nfs_server.addrlen,
-               .nfs_mod = nfs_mod,
+               .nfs_mod = ctx->nfs_mod,
                .proto = ctx->nfs_server.protocol,
-               .net = ctx->net,
+               .net = fc->net_ns,
                .timeparms = &timeparms,
                .cred = server->cred,
                .nconnect = ctx->nfs_server.nconnect,
@@ -940,10 +940,10 @@ EXPORT_SYMBOL_GPL(nfs_free_server);
  * Create a version 2 or 3 volume record
  * - keyed on server and FSID
  */
-struct nfs_server *nfs_create_server(struct nfs_mount_info *mount_info)
+struct nfs_server *nfs_create_server(struct fs_context *fc)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct nfs_server *server;
-       struct nfs_subversion *nfs_mod = mount_info->nfs_mod;
        struct nfs_fattr *fattr;
        int error;
 
@@ -959,18 +959,18 @@ struct nfs_server *nfs_create_server(struct 
nfs_mount_info *mount_info)
                goto error;
 
        /* Get a client representation */
-       error = nfs_init_server(server, mount_info->ctx, nfs_mod);
+       error = nfs_init_server(server, fc);
        if (error < 0)
                goto error;
 
        /* Probe the root fh to retrieve its FSID */
-       error = nfs_probe_fsinfo(server, mount_info->mntfh, fattr);
+       error = nfs_probe_fsinfo(server, ctx->mntfh, fattr);
        if (error < 0)
                goto error;
        if (server->nfs_client->rpc_ops->version == 3) {
                if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
                        server->namelen = NFS3_MAXNAMLEN;
-               if (!(mount_info->ctx->flags & NFS_MOUNT_NORDIRPLUS))
+               if (!(ctx->flags & NFS_MOUNT_NORDIRPLUS))
                        server->caps |= NFS_CAP_READDIRPLUS;
        } else {
                if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
@@ -978,8 +978,8 @@ struct nfs_server *nfs_create_server(struct nfs_mount_info 
*mount_info)
        }
 
        if (!(fattr->valid & NFS_ATTR_FATTR)) {
-               error = nfs_mod->rpc_ops->getattr(server, mount_info->mntfh,
-                               fattr, NULL, NULL);
+               error = ctx->nfs_mod->rpc_ops->getattr(server, ctx->mntfh,
+                                                      fattr, NULL, NULL);
                if (error < 0) {
                        dprintk("nfs_create_server: getattr error = %d\n", 
-error);
                        goto error;
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index d65f5d7a488e..14c43d1c7da9 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -244,43 +244,6 @@ static const struct constant_table nfs_secflavor_tokens[] 
= {
        { "sys",        Opt_sec_sys },
 };
 
-struct nfs_fs_context *nfs_alloc_parsed_mount_data(void)
-{
-       struct nfs_fs_context *ctx;
-
-       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
-       if (ctx) {
-               ctx->timeo              = NFS_UNSPEC_TIMEO;
-               ctx->retrans            = NFS_UNSPEC_RETRANS;
-               ctx->acregmin           = NFS_DEF_ACREGMIN;
-               ctx->acregmax           = NFS_DEF_ACREGMAX;
-               ctx->acdirmin           = NFS_DEF_ACDIRMIN;
-               ctx->acdirmax           = NFS_DEF_ACDIRMAX;
-               ctx->mount_server.port  = NFS_UNSPEC_PORT;
-               ctx->nfs_server.port    = NFS_UNSPEC_PORT;
-               ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
-               ctx->selected_flavor    = RPC_AUTH_MAXFLAVOR;
-               ctx->minorversion       = 0;
-               ctx->need_mount = true;
-               ctx->net                = current->nsproxy->net_ns;
-               ctx->lsm_opts = NULL;
-       }
-       return ctx;
-}
-
-void nfs_free_parsed_mount_data(struct nfs_fs_context *ctx)
-{
-       if (ctx) {
-               kfree(ctx->client_address);
-               kfree(ctx->mount_server.hostname);
-               kfree(ctx->nfs_server.export_path);
-               kfree(ctx->nfs_server.hostname);
-               kfree(ctx->fscache_uniq);
-               security_free_mnt_opts(&ctx->lsm_opts);
-               kfree(ctx);
-       }
-}
-
 /*
  * Sanity-check a server address provided by the mount command.
  *
@@ -345,7 +308,7 @@ static void nfs_set_mount_transport_protocol(struct 
nfs_fs_context *ctx)
  * Add 'flavor' to 'auth_info' if not already present.
  * Returns true if 'flavor' ends up in the list, false otherwise
  */
-static int nfs_auth_info_add(struct nfs_fs_context *ctx,
+static int nfs_auth_info_add(struct fs_context *fc,
                             struct nfs_auth_info *auth_info,
                             rpc_authflavor_t flavor)
 {
@@ -370,9 +333,10 @@ static int nfs_auth_info_add(struct nfs_fs_context *ctx,
 /*
  * Parse the value of the 'sec=' option.
  */
-static int nfs_parse_security_flavors(struct nfs_fs_context *ctx,
+static int nfs_parse_security_flavors(struct fs_context *fc,
                                      struct fs_parameter *param)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        rpc_authflavor_t pseudoflavor;
        char *string = param->string, *p;
        int ret;
@@ -422,7 +386,7 @@ static int nfs_parse_security_flavors(struct nfs_fs_context 
*ctx,
                        return -EINVAL;
                }
 
-               ret = nfs_auth_info_add(ctx, &ctx->auth_info, pseudoflavor);
+               ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
                if (ret < 0)
                        return ret;
        }
@@ -430,9 +394,11 @@ static int nfs_parse_security_flavors(struct 
nfs_fs_context *ctx,
        return 0;
 }
 
-static int nfs_parse_version_string(struct nfs_fs_context *ctx,
+static int nfs_parse_version_string(struct fs_context *fc,
                                    const char *string)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+
        ctx->flags &= ~NFS_MOUNT_VER3;
        switch (lookup_constant(nfs_vers_tokens, string, -1)) {
        case Opt_vers_2:
@@ -471,21 +437,31 @@ static int nfs_parse_version_string(struct nfs_fs_context 
*ctx,
 /*
  * Parse a single mount parameter.
  */
-static int nfs_fs_context_parse_param(struct nfs_fs_context *ctx,
+static int nfs_fs_context_parse_param(struct fs_context *fc,
                                      struct fs_parameter *param)
 {
        struct fs_parse_result result;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        unsigned short protofamily, mountfamily;
        unsigned int len;
        int ret, opt;
 
        dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", param->key);
 
-       opt = fs_parse(NULL, &nfs_fs_parameters, param, &result);
+       opt = fs_parse(fc, &nfs_fs_parameters, param, &result);
        if (opt < 0)
                return ctx->sloppy ? 1 : opt;
 
        switch (opt) {
+       case Opt_source:
+               if (fc->source) {
+                       dfprintk(MOUNT, "NFS: Multiple sources not 
supported\n");
+                       return -EINVAL;
+               }
+               fc->source = param->string;
+               param->string = NULL;
+               break;
+
                /*
                 * boolean options:  foo/nofoo
                 */
@@ -649,17 +625,17 @@ static int nfs_fs_context_parse_param(struct 
nfs_fs_context *ctx,
                 * options that take text values
                 */
        case Opt_v:
-               ret = nfs_parse_version_string(ctx, param->key + 1);
+               ret = nfs_parse_version_string(fc, param->key + 1);
                if (ret < 0)
                        return ret;
                break;
        case Opt_vers:
-               ret = nfs_parse_version_string(ctx, param->string);
+               ret = nfs_parse_version_string(fc, param->string);
                if (ret < 0)
                        return ret;
                break;
        case Opt_sec:
-               ret = nfs_parse_security_flavors(ctx, param);
+               ret = nfs_parse_security_flavors(fc, param);
                if (ret < 0)
                        return ret;
                break;
@@ -722,7 +698,7 @@ static int nfs_fs_context_parse_param(struct nfs_fs_context 
*ctx,
                break;
 
        case Opt_addr:
-               len = rpc_pton(ctx->net, param->string, param->size,
+               len = rpc_pton(fc->net_ns, param->string, param->size,
                               &ctx->nfs_server.address,
                               sizeof(ctx->nfs_server._address));
                if (len == 0)
@@ -740,7 +716,7 @@ static int nfs_fs_context_parse_param(struct nfs_fs_context 
*ctx,
                param->string = NULL;
                break;
        case Opt_mountaddr:
-               len = rpc_pton(ctx->net, param->string, param->size,
+               len = rpc_pton(fc->net_ns, param->string, param->size,
                               &ctx->mount_server.address,
                               sizeof(ctx->mount_server._address));
                if (len == 0)
@@ -811,114 +787,8 @@ static int nfs_fs_context_parse_param(struct 
nfs_fs_context *ctx,
        return -ERANGE;
 }
 
-/* cribbed from generic_parse_monolithic and vfs_parse_fs_string */
-static int nfs_fs_context_parse_option(struct nfs_fs_context *ctx, char *p)
-{
-       int ret;
-       char *key = p, *value;
-       size_t v_size = 0;
-       struct fs_parameter param;
-
-       memset(&param, 0, sizeof(param));
-       value = strchr(key, '=');
-       if (value && value != key) {
-               *value++ = 0;
-               v_size = strlen(value);
-       }
-       param.key = key;
-       param.type = fs_value_is_flag;
-       param.size = v_size;
-       if (v_size > 0) {
-               param.type = fs_value_is_string;
-               param.string = kmemdup_nul(value, v_size, GFP_KERNEL);
-               if (!param.string)
-                       return -ENOMEM;
-       }
-       ret = nfs_fs_context_parse_param(ctx, &param);
-       kfree(param.string);
-       return ret;
-}
-
 /*
- * Error-check and convert a string of mount options from user space into
- * a data structure.  The whole mount string is processed; bad options are
- * skipped as they are encountered.  If there were no errors, return 1;
- * otherwise return 0 (zero).
- */
-int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
-{
-       char *p;
-       int rc, sloppy = 0, invalid_option = 0;
-
-       if (!raw) {
-               dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
-               return 1;
-       }
-       dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
-
-       rc = security_sb_eat_lsm_opts(raw, &ctx->lsm_opts);
-       if (rc)
-               goto out_security_failure;
-
-       while ((p = strsep(&raw, ",")) != NULL) {
-               if (!*p)
-                       continue;
-               if (nfs_fs_context_parse_option(ctx, p) < 0)
-                       invalid_option = true;
-       }
-
-       if (!sloppy && invalid_option)
-               return 0;
-
-       if (ctx->minorversion && ctx->version != 4)
-               goto out_minorversion_mismatch;
-
-       if (ctx->options & NFS_OPTION_MIGRATION &&
-           (ctx->version != 4 || ctx->minorversion != 0))
-               goto out_migration_misuse;
-
-       /*
-        * verify that any proto=/mountproto= options match the address
-        * families in the addr=/mountaddr= options.
-        */
-       if (ctx->protofamily != AF_UNSPEC &&
-           ctx->protofamily != ctx->nfs_server.address.sa_family)
-               goto out_proto_mismatch;
-
-       if (ctx->mountfamily != AF_UNSPEC) {
-               if (ctx->mount_server.addrlen) {
-                       if (ctx->mountfamily != 
ctx->mount_server.address.sa_family)
-                               goto out_mountproto_mismatch;
-               } else {
-                       if (ctx->mountfamily != 
ctx->nfs_server.address.sa_family)
-                               goto out_mountproto_mismatch;
-               }
-       }
-
-       return 1;
-
-out_minorversion_mismatch:
-       printk(KERN_INFO "NFS: mount option vers=%u does not support "
-                        "minorversion=%u\n", ctx->version, ctx->minorversion);
-       return 0;
-out_mountproto_mismatch:
-       printk(KERN_INFO "NFS: mount server address does not match mountproto= "
-                        "option\n");
-       return 0;
-out_proto_mismatch:
-       printk(KERN_INFO "NFS: server address does not match proto= option\n");
-       return 0;
-out_migration_misuse:
-       printk(KERN_INFO
-               "NFS: 'migration' not supported for this NFS version\n");
-       return -EINVAL;
-out_security_failure:
-       printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
-       return 0;
-}
-
-/*
- * Split "dev_name" into "hostname:export_path".
+ * Split fc->source into "hostname:export_path".
  *
  * The leftmost colon demarks the split between the server's hostname
  * and the export path.  If the hostname starts with a left square
@@ -926,12 +796,13 @@ int nfs_parse_mount_options(char *raw, struct 
nfs_fs_context *ctx)
  *
  * Note: caller frees hostname and export path, even on error.
  */
-static int nfs_parse_devname(struct nfs_fs_context *ctx,
-                            const char *dev_name,
-                            size_t maxnamlen, size_t maxpathlen)
+static int nfs_parse_source(struct fs_context *fc,
+                           size_t maxnamlen, size_t maxpathlen)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       const char *dev_name = fc->source;
        size_t len;
-       char *end;
+       const char *end;
 
        if (unlikely(!dev_name || !*dev_name)) {
                dfprintk(MOUNT, "NFS: device name not specified\n");
@@ -947,7 +818,7 @@ static int nfs_parse_devname(struct nfs_fs_context *ctx,
                len = end - dev_name;
                end++;
        } else {
-               char *comma;
+               const char *comma;
 
                end = strchr(dev_name, ':');
                if (end == NULL)
@@ -955,8 +826,8 @@ static int nfs_parse_devname(struct nfs_fs_context *ctx,
                len = end - dev_name;
 
                /* kill possible hostname list: not supported */
-               comma = strchr(dev_name, ',');
-               if (comma != NULL && comma < end)
+               comma = memchr(dev_name, ',', len);
+               if (comma)
                        len = comma - dev_name;
        }
 
@@ -994,6 +865,11 @@ static int nfs_parse_devname(struct nfs_fs_context *ctx,
        return -ENAMETOOLONG;
 }
 
+static inline bool is_remount_fc(struct fs_context *fc)
+{
+       return fc->root != NULL;
+}
+
 /*
  * Parse monolithic NFS2/NFS3 mount data
  * - fills in the mount root filehandle
@@ -1010,12 +886,11 @@ static int nfs_parse_devname(struct nfs_fs_context *ctx,
  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
  *   mountproto=tcp after mountproto=udp, and so on
  */
-static int nfs23_validate_mount_data(void *options,
-                                    struct nfs_fs_context *ctx,
-                                    struct nfs_fh *mntfh,
-                                    const char *dev_name)
+static int nfs23_parse_monolithic(struct fs_context *fc,
+                                 struct nfs_mount_data *data)
 {
-       struct nfs_mount_data *data = (struct nfs_mount_data *)options;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct nfs_fh *mntfh = ctx->mntfh;
        struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
        int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
 
@@ -1087,6 +962,9 @@ static int nfs23_validate_mount_data(void *options,
                        ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
                /* N.B. caller will free nfs_server.hostname in all cases */
                ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
+               if (!ctx->nfs_server.hostname)
+                       goto out_nomem;
+
                ctx->namlen             = data->namlen;
                ctx->bsize              = data->bsize;
 
@@ -1094,8 +972,6 @@ static int nfs23_validate_mount_data(void *options,
                        ctx->selected_flavor = data->pseudoflavor;
                else
                        ctx->selected_flavor = RPC_AUTH_UNIX;
-               if (!ctx->nfs_server.hostname)
-                       goto out_nomem;
 
                if (!(data->flags & NFS_MOUNT_NONLM))
                        ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
@@ -1103,6 +979,7 @@ static int nfs23_validate_mount_data(void *options,
                else
                        ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
                                        NFS_MOUNT_LOCAL_FCNTL);
+
                /*
                 * The legacy version 6 binary mount data from userspace has a
                 * field used only to transport selinux information into the
@@ -1113,12 +990,13 @@ static int nfs23_validate_mount_data(void *options,
                 */
                if (data->context[0]){
 #ifdef CONFIG_SECURITY_SELINUX
-                       int rc;
+                       int ret;
+
                        data->context[NFS_MAX_CONTEXT_LEN] = '\0';
-                       rc = security_add_mnt_opt("context", data->context,
-                                       strlen(data->context), ctx->lsm_opts);
-                       if (rc)
-                               return rc;
+                       ret = vfs_parse_fs_string(fc, "context",
+                                                 data->context, 
strlen(data->context));
+                       if (ret < 0)
+                               return ret;
 #else
                        return -EINVAL;
 #endif
@@ -1126,12 +1004,20 @@ static int nfs23_validate_mount_data(void *options,
 
                break;
        default:
-               return NFS_TEXT_DATA;
+               goto generic;
        }
 
+       ctx->skip_reconfig_option_check = true;
        return 0;
 
+generic:
+       return generic_parse_monolithic(fc, data);
+
 out_no_data:
+       if (is_remount_fc(fc)) {
+               ctx->skip_reconfig_option_check = true;
+               return 0;
+       }
        dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
        return -EINVAL;
 
@@ -1158,21 +1044,14 @@ static int nfs23_validate_mount_data(void *options,
 }
 
 #if IS_ENABLED(CONFIG_NFS_V4)
-static void nfs4_validate_mount_flags(struct nfs_fs_context *ctx)
-{
-       ctx->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
-                        NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
-}
-
 /*
  * Validate NFSv4 mount options
  */
-static int nfs4_validate_mount_data(void *options,
-                                   struct nfs_fs_context *ctx,
-                                   const char *dev_name)
+static int nfs4_parse_monolithic(struct fs_context *fc,
+                                struct nfs4_mount_data *data)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
-       struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
        char *c;
 
        if (data == NULL)
@@ -1222,7 +1101,7 @@ static int nfs4_validate_mount_data(void *options,
                ctx->client_address = c;
 
                /*
-                * Translate to nfs_fs_context, which nfs4_fill_super
+                * Translate to nfs_fs_context, which nfs_fill_super
                 * can deal with.
                 */
 
@@ -1242,12 +1121,20 @@ static int nfs4_validate_mount_data(void *options,
 
                break;
        default:
-               return NFS_TEXT_DATA;
+               goto generic;
        }
 
+       ctx->skip_reconfig_option_check = true;
        return 0;
 
+generic:
+       return generic_parse_monolithic(fc, data);
+
 out_no_data:
+       if (is_remount_fc(fc)) {
+               ctx->skip_reconfig_option_check = true;
+               return 0;
+       }
        dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
        return -EINVAL;
 
@@ -1264,58 +1151,87 @@ static int nfs4_validate_mount_data(void *options,
        dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
        return -EINVAL;
 }
+#endif
 
-int nfs_validate_mount_data(struct file_system_type *fs_type,
-                           void *options,
-                           struct nfs_fs_context *ctx,
-                           struct nfs_fh *mntfh,
-                           const char *dev_name)
-{
-       if (fs_type == &nfs_fs_type)
-               return nfs23_validate_mount_data(options, ctx, mntfh, dev_name);
-       return nfs4_validate_mount_data(options, ctx, dev_name);
-}
-#else
-int nfs_validate_mount_data(struct file_system_type *fs_type,
-                           void *options,
-                           struct nfs_fs_context *ctx,
-                           struct nfs_fh *mntfh,
-                           const char *dev_name)
+/*
+ * Parse a monolithic block of data from sys_mount().
+ */
+static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
+                                          void *data)
 {
-       return nfs23_validate_mount_data(options, ctx, mntfh, dev_name);
-}
+       if (fc->fs_type == &nfs_fs_type)
+               return nfs23_parse_monolithic(fc, data);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+       if (fc->fs_type == &nfs4_fs_type)
+               return nfs4_parse_monolithic(fc, data);
 #endif
 
-int nfs_validate_text_mount_data(void *options,
-                                struct nfs_fs_context *ctx,
-                                const char *dev_name)
+       dfprintk(MOUNT, "NFS: Unsupported monolithic data version\n");
+       return -EINVAL;
+}
+
+/*
+ * Validate the preparsed information in the config.
+ */
+static int nfs_fs_context_validate(struct fs_context *fc)
 {
-       int port = 0;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct nfs_subversion *nfs_mod;
+       struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
        int max_namelen = PAGE_SIZE;
        int max_pathlen = NFS_MAXPATHLEN;
-       struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
+       int port = 0;
+       int ret;
 
-       if (nfs_parse_mount_options((char *)options, ctx) == 0)
-               return -EINVAL;
+       if (!fc->source)
+               goto out_no_device_name;
+
+       /* Check for sanity first. */
+       if (ctx->minorversion && ctx->version != 4)
+               goto out_minorversion_mismatch;
+
+       if (ctx->options & NFS_OPTION_MIGRATION &&
+           (ctx->version != 4 || ctx->minorversion != 0))
+               goto out_migration_misuse;
+
+       /* Verify that any proto=/mountproto= options match the address
+        * families in the addr=/mountaddr= options.
+        */
+       if (ctx->protofamily != AF_UNSPEC &&
+           ctx->protofamily != ctx->nfs_server.address.sa_family)
+               goto out_proto_mismatch;
+
+       if (ctx->mountfamily != AF_UNSPEC) {
+               if (ctx->mount_server.addrlen) {
+                       if (ctx->mountfamily != 
ctx->mount_server.address.sa_family)
+                               goto out_mountproto_mismatch;
+               } else {
+                       if (ctx->mountfamily != 
ctx->nfs_server.address.sa_family)
+                               goto out_mountproto_mismatch;
+               }
+       }
 
        if (!nfs_verify_server_address(sap))
                goto out_no_address;
 
        if (ctx->version == 4) {
-#if IS_ENABLED(CONFIG_NFS_V4)
-               if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
-                       port = NFS_RDMA_PORT;
-               else
-                       port = NFS_PORT;
-               max_namelen = NFS4_MAXNAMLEN;
-               max_pathlen = NFS4_MAXPATHLEN;
-               nfs_validate_transport_protocol(ctx);
-               if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
-                       goto out_invalid_transport_udp;
-               nfs4_validate_mount_flags(ctx);
-#else
-               goto out_v4_not_compiled;
-#endif /* CONFIG_NFS_V4 */
+               if (IS_ENABLED(CONFIG_NFS_V4)) {
+                       if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
+                               port = NFS_RDMA_PORT;
+                       else
+                               port = NFS_PORT;
+                       max_namelen = NFS4_MAXNAMLEN;
+                       max_pathlen = NFS4_MAXPATHLEN;
+                       nfs_validate_transport_protocol(ctx);
+                       if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
+                               goto out_invalid_transport_udp;
+                       ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
+                                       NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
+                                       NFS_MOUNT_LOCAL_FCNTL);
+               } else {
+                       goto out_v4_not_compiled;
+               }
        } else {
                nfs_set_mount_transport_protocol(ctx);
                if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
@@ -1324,19 +1240,219 @@ int nfs_validate_text_mount_data(void *options,
 
        nfs_set_port(sap, &ctx->nfs_server.port, port);
 
-       return nfs_parse_devname(ctx, dev_name, max_namelen, max_pathlen);
+       ret = nfs_parse_source(fc, max_namelen, max_pathlen);
+       if (ret < 0)
+               return ret;
+
+       /* Load the NFS protocol module if we haven't done so yet */
+       if (!ctx->nfs_mod) {
+               nfs_mod = get_nfs_version(ctx->version);
+               if (IS_ERR(nfs_mod)) {
+                       ret = PTR_ERR(nfs_mod);
+                       goto out_version_unavailable;
+               }
+               ctx->nfs_mod = nfs_mod;
+       }
+       return 0;
 
-#if !IS_ENABLED(CONFIG_NFS_V4)
+out_no_device_name:
+       dfprintk(MOUNT, "NFS: Device name not specified\n");
+       return -EINVAL;
 out_v4_not_compiled:
        dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
        return -EPROTONOSUPPORT;
-#else
 out_invalid_transport_udp:
        dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
        return -EINVAL;
-#endif /* !CONFIG_NFS_V4 */
-
 out_no_address:
        dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
        return -EINVAL;
+out_mountproto_mismatch:
+       dfprintk(MOUNT, "NFS: Mount server address does not match mountproto= 
option\n");
+       return -EINVAL;
+out_proto_mismatch:
+       dfprintk(MOUNT, "NFS: Server address does not match proto= option\n");
+       return -EINVAL;
+out_minorversion_mismatch:
+       dfprintk(MOUNT, "NFS: Mount option vers=%u does not support 
minorversion=%u\n",
+                         ctx->version, ctx->minorversion);
+       return -EINVAL;
+out_migration_misuse:
+       dfprintk(MOUNT, "NFS: 'Migration' not supported for this NFS 
version\n");
+       return -EINVAL;
+out_version_unavailable:
+       dfprintk(MOUNT, "NFS: Version unavailable\n");
+       return ret;
+}
+
+/*
+ * Create an NFS superblock by the appropriate method.
+ */
+static int nfs_get_tree(struct fs_context *fc)
+{
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       int err = nfs_fs_context_validate(fc);
+
+       if (err)
+               return err;
+       if (!ctx->internal)
+               return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
+       else
+               return nfs_get_tree_common(fc);
+}
+
+/*
+ * Handle duplication of a configuration.  The caller copied *src into *sc, but
+ * it can't deal with resource pointers in the filesystem context, so we have
+ * to do that.  We need to clear pointers, copy data or get extra refs as
+ * appropriate.
+ */
+static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
+{
+       struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
+
+       ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
+       if (!ctx)
+               return -ENOMEM;
+
+       ctx->mntfh = nfs_alloc_fhandle();
+       if (!ctx->mntfh) {
+               kfree(ctx);
+               return -ENOMEM;
+       }
+       nfs_copy_fh(ctx->mntfh, src->mntfh);
+
+       __module_get(ctx->nfs_mod->owner);
+       ctx->client_address             = NULL;
+       ctx->mount_server.hostname      = NULL;
+       ctx->nfs_server.export_path     = NULL;
+       ctx->nfs_server.hostname        = NULL;
+       ctx->fscache_uniq               = NULL;
+       fc->fs_private = ctx;
+       return 0;
+}
+
+static void nfs_fs_context_free(struct fs_context *fc)
+{
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+
+       if (ctx) {
+               if (ctx->server)
+                       nfs_free_server(ctx->server);
+               if (ctx->nfs_mod)
+                       put_nfs_version(ctx->nfs_mod);
+               kfree(ctx->client_address);
+               kfree(ctx->mount_server.hostname);
+               kfree(ctx->nfs_server.export_path);
+               kfree(ctx->nfs_server.hostname);
+               kfree(ctx->fscache_uniq);
+               nfs_free_fhandle(ctx->mntfh);
+               kfree(ctx);
+       }
+}
+
+static const struct fs_context_operations nfs_fs_context_ops = {
+       .free                   = nfs_fs_context_free,
+       .dup                    = nfs_fs_context_dup,
+       .parse_param            = nfs_fs_context_parse_param,
+       .parse_monolithic       = nfs_fs_context_parse_monolithic,
+       .get_tree               = nfs_get_tree,
+       .reconfigure            = nfs_reconfigure,
+};
+
+/*
+ * Prepare superblock configuration.  We use the namespaces attached to the
+ * context.  This may be the current process's namespaces, or it may be a
+ * container's namespaces.
+ */
+static int nfs_init_fs_context(struct fs_context *fc)
+{
+       struct nfs_fs_context *ctx;
+
+       ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
+       if (unlikely(!ctx))
+               return -ENOMEM;
+
+       ctx->mntfh = nfs_alloc_fhandle();
+       if (unlikely(!ctx->mntfh)) {
+               kfree(ctx);
+               return -ENOMEM;
+       }
+
+       ctx->protofamily        = AF_UNSPEC;
+       ctx->mountfamily        = AF_UNSPEC;
+       ctx->mount_server.port  = NFS_UNSPEC_PORT;
+
+       if (fc->root) {
+               /* reconfigure, start with the current config */
+               struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
+               struct net *net = nfss->nfs_client->cl_net;
+
+               ctx->flags              = nfss->flags;
+               ctx->rsize              = nfss->rsize;
+               ctx->wsize              = nfss->wsize;
+               ctx->retrans            = nfss->client->cl_timeout->to_retries;
+               ctx->selected_flavor    = nfss->client->cl_auth->au_flavor;
+               ctx->acregmin           = nfss->acregmin / HZ;
+               ctx->acregmax           = nfss->acregmax / HZ;
+               ctx->acdirmin           = nfss->acdirmin / HZ;
+               ctx->acdirmax           = nfss->acdirmax / HZ;
+               ctx->timeo              = 10U * 
nfss->client->cl_timeout->to_initval / HZ;
+               ctx->nfs_server.port    = nfss->port;
+               ctx->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
+               ctx->version            = nfss->nfs_client->rpc_ops->version;
+               ctx->minorversion       = nfss->nfs_client->cl_minorversion;
+
+               memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
+                       ctx->nfs_server.addrlen);
+
+               if (fc->net_ns != net) {
+                       put_net(fc->net_ns);
+                       fc->net_ns = get_net(net);
+               }
+
+               ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
+               __module_get(ctx->nfs_mod->owner);
+       } else {
+               /* defaults */
+               ctx->timeo              = NFS_UNSPEC_TIMEO;
+               ctx->retrans            = NFS_UNSPEC_RETRANS;
+               ctx->acregmin           = NFS_DEF_ACREGMIN;
+               ctx->acregmax           = NFS_DEF_ACREGMAX;
+               ctx->acdirmin           = NFS_DEF_ACDIRMIN;
+               ctx->acdirmax           = NFS_DEF_ACDIRMAX;
+               ctx->nfs_server.port    = NFS_UNSPEC_PORT;
+               ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
+               ctx->selected_flavor    = RPC_AUTH_MAXFLAVOR;
+               ctx->minorversion       = 0;
+               ctx->need_mount         = true;
+       }
+       fc->fs_private = ctx;
+       fc->ops = &nfs_fs_context_ops;
+       return 0;
 }
+
+struct file_system_type nfs_fs_type = {
+       .owner                  = THIS_MODULE,
+       .name                   = "nfs",
+       .init_fs_context        = nfs_init_fs_context,
+       .parameters             = &nfs_fs_parameters,
+       .kill_sb                = nfs_kill_super,
+       .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
+};
+MODULE_ALIAS_FS("nfs");
+EXPORT_SYMBOL_GPL(nfs_fs_type);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+struct file_system_type nfs4_fs_type = {
+       .owner                  = THIS_MODULE,
+       .name                   = "nfs4",
+       .init_fs_context        = nfs_init_fs_context,
+       .parameters             = &nfs_fs_parameters,
+       .kill_sb                = nfs_kill_super,
+       .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
+};
+MODULE_ALIAS_FS("nfs4");
+MODULE_ALIAS("nfs4");
+EXPORT_SYMBOL_GPL(nfs4_fs_type);
+#endif /* CONFIG_NFS_V4 */
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index 3800ab6f08fa..4a8df8c30a03 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -128,7 +128,7 @@ void nfs_fscache_get_super_cookie(struct super_block *sb, 
const char *uniq, int
                return;
 
        key->nfs_client = nfss->nfs_client;
-       key->key.super.s_flags = sb->s_flags & NFS_MS_MASK;
+       key->key.super.s_flags = sb->s_flags & NFS_SB_MASK;
        key->key.nfs_server.flags = nfss->flags;
        key->key.nfs_server.rsize = nfss->rsize;
        key->key.nfs_server.wsize = nfss->wsize;
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 878c4c5982d9..ab45496d23a6 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -64,66 +64,68 @@ static int nfs_superblock_set_dummy_root(struct super_block 
*sb, struct inode *i
 /*
  * get an NFS2/NFS3 root dentry from the root filehandle
  */
-struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh,
-                           const char *devname)
+int nfs_get_root(struct super_block *s, struct fs_context *fc)
 {
-       struct nfs_server *server = NFS_SB(sb);
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct nfs_server *server = NFS_SB(s);
        struct nfs_fsinfo fsinfo;
-       struct dentry *ret;
+       struct dentry *root;
        struct inode *inode;
-       void *name = kstrdup(devname, GFP_KERNEL);
-       int error;
+       char *name;
+       int error = -ENOMEM;
 
+       name = kstrdup(fc->source, GFP_KERNEL);
        if (!name)
-               return ERR_PTR(-ENOMEM);
+               goto out;
 
        /* get the actual root for this mount */
        fsinfo.fattr = nfs_alloc_fattr();
-       if (fsinfo.fattr == NULL) {
-               kfree(name);
-               return ERR_PTR(-ENOMEM);
-       }
+       if (fsinfo.fattr == NULL)
+               goto out_name;
 
-       error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
+       error = server->nfs_client->rpc_ops->getroot(server, ctx->mntfh, 
&fsinfo);
        if (error < 0) {
                dprintk("nfs_get_root: getattr error = %d\n", -error);
-               ret = ERR_PTR(error);
-               goto out;
+               goto out_fattr;
        }
 
-       inode = nfs_fhget(sb, mntfh, fsinfo.fattr, NULL);
+       inode = nfs_fhget(s, ctx->mntfh, fsinfo.fattr, NULL);
        if (IS_ERR(inode)) {
                dprintk("nfs_get_root: get root inode failed\n");
-               ret = ERR_CAST(inode);
-               goto out;
+               error = PTR_ERR(inode);
+               goto out_fattr;
        }
 
-       error = nfs_superblock_set_dummy_root(sb, inode);
-       if (error != 0) {
-               ret = ERR_PTR(error);
-               goto out;
-       }
+       error = nfs_superblock_set_dummy_root(s, inode);
+       if (error != 0)
+               goto out_fattr;
 
        /* 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
         */
-       ret = d_obtain_root(inode);
-       if (IS_ERR(ret)) {
+       root = d_obtain_root(inode);
+       if (IS_ERR(root)) {
                dprintk("nfs_get_root: get root dentry failed\n");
-               goto out;
+               error = PTR_ERR(root);
+               goto out_fattr;
        }
 
-       security_d_instantiate(ret, inode);
-       spin_lock(&ret->d_lock);
-       if (IS_ROOT(ret) && !ret->d_fsdata &&
-           !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
-               ret->d_fsdata = name;
+       security_d_instantiate(root, inode);
+       spin_lock(&root->d_lock);
+       if (IS_ROOT(root) && !root->d_fsdata &&
+           !(root->d_flags & DCACHE_NFSFS_RENAMED)) {
+               root->d_fsdata = name;
                name = NULL;
        }
-       spin_unlock(&ret->d_lock);
-out:
-       kfree(name);
+       spin_unlock(&root->d_lock);
+       fc->root = root;
+       error = 0;
+
+out_fattr:
        nfs_free_fattr(fsinfo.fattr);
-       return ret;
+out_name:
+       kfree(name);
+out:
+       return error;
 }
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index caaf0af1bc7f..e0911815e153 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -4,18 +4,19 @@
  */
 
 #include "nfs4_fs.h"
-#include <linux/mount.h>
+#include <linux/fs_context.h>
 #include <linux/security.h>
 #include <linux/crc32.h>
 #include <linux/sunrpc/addr.h>
 #include <linux/nfs_page.h>
 #include <linux/wait_bit.h>
 
-#define NFS_MS_MASK (SB_RDONLY|SB_NOSUID|SB_NODEV|SB_NOEXEC|SB_SYNCHRONOUS)
+#define NFS_SB_MASK (SB_RDONLY|SB_NOSUID|SB_NODEV|SB_NOEXEC|SB_SYNCHRONOUS)
 
 extern const struct export_operations nfs_export_ops;
 
 struct nfs_string;
+struct nfs_pageio_descriptor;
 
 /* Maximum number of readahead requests
  * FIXME: this should really be a sysctl so that users may tune it to suit
@@ -40,16 +41,6 @@ static inline int nfs_attr_use_mounted_on_fileid(struct 
nfs_fattr *fattr)
        return 1;
 }
 
-struct nfs_clone_mount {
-       const struct super_block *sb;
-       const struct dentry *dentry;
-       char *hostname;
-       char *mnt_path;
-       struct sockaddr *addr;
-       size_t addrlen;
-       rpc_authflavor_t authflavor;
-};
-
 /*
  * Note: RFC 1813 doesn't limit the number of auth flavors that
  * a server can return, so make something up.
@@ -90,6 +81,10 @@ struct nfs_client_initdata {
  * In-kernel mount arguments
  */
 struct nfs_fs_context {
+       bool                    internal;
+       bool                    skip_reconfig_option_check;
+       bool                    need_mount;
+       bool                    sloppy;
        unsigned int            flags;          /* NFS{,4}_MOUNT_* flags */
        unsigned int            rsize, wsize;
        unsigned int            timeo, retrans;
@@ -106,8 +101,6 @@ struct nfs_fs_context {
        char                    *fscache_uniq;
        unsigned short          protofamily;
        unsigned short          mountfamily;
-       bool                    need_mount;
-       bool                    sloppy;
 
        struct {
                union {
@@ -132,14 +125,27 @@ struct nfs_fs_context {
                int                     port;
                unsigned short          protocol;
                unsigned short          nconnect;
+               unsigned short          export_path_len;
        } nfs_server;
 
-       void                    *lsm_opts;
-       struct net              *net;
-
-       char                    buf[32];        /* Parse buffer */
+       struct nfs_fh           *mntfh;
+       struct nfs_server       *server;
+       struct nfs_subversion   *nfs_mod;
+
+       /* Information for a cloned mount. */
+       struct nfs_clone_mount {
+               struct super_block      *sb;
+               struct dentry           *dentry;
+               struct nfs_fattr        *fattr;
+               unsigned int            inherited_bsize;
+       } clone_data;
 };
 
+static inline struct nfs_fs_context *nfs_fc2context(const struct fs_context 
*fc)
+{
+       return fc->fs_private;
+}
+
 /* mount_clnt.c */
 struct nfs_mount_request {
        struct sockaddr         *sap;
@@ -155,15 +161,6 @@ struct nfs_mount_request {
        struct net              *net;
 };
 
-struct nfs_mount_info {
-       unsigned int inherited_bsize;
-       struct nfs_fs_context *ctx;
-       struct nfs_clone_mount *cloned;
-       struct nfs_server *server;
-       struct nfs_fh *mntfh;
-       struct nfs_subversion *nfs_mod;
-};
-
 extern int nfs_mount(struct nfs_mount_request *info);
 extern void nfs_umount(const struct nfs_mount_request *info);
 
@@ -189,10 +186,9 @@ extern struct nfs_client *nfs4_find_client_ident(struct 
net *, int);
 extern struct nfs_client *
 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
                                struct nfs4_sessionid *, u32);
-extern struct nfs_server *nfs_create_server(struct nfs_mount_info *);
-extern struct nfs_server *nfs4_create_server(struct nfs_mount_info *);
-extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
-                                                     struct nfs_fh *);
+extern struct nfs_server *nfs_create_server(struct fs_context *);
+extern struct nfs_server *nfs4_create_server(struct fs_context *);
+extern struct nfs_server *nfs4_create_referral_server(struct fs_context *);
 extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
                                        struct sockaddr *sap, size_t salen,
                                        struct net *net);
@@ -243,22 +239,8 @@ static inline void nfs_fs_proc_exit(void)
 extern const struct svc_version nfs4_callback_version1;
 extern const struct svc_version nfs4_callback_version4;
 
-struct nfs_pageio_descriptor;
-
-/* mount.c */
-#define NFS_TEXT_DATA          1
-
-extern struct nfs_fs_context *nfs_alloc_parsed_mount_data(void);
-extern void nfs_free_parsed_mount_data(struct nfs_fs_context *ctx);
-extern int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx);
-extern int nfs_validate_mount_data(struct file_system_type *fs_type,
-                                  void *options,
-                                  struct nfs_fs_context *ctx,
-                                  struct nfs_fh *mntfh,
-                                  const char *dev_name);
-extern int nfs_validate_text_mount_data(void *options,
-                                       struct nfs_fs_context *ctx,
-                                       const char *dev_name);
+/* fs_context.c */
+extern struct file_system_type nfs_fs_type;
 
 /* pagelist.c */
 extern int __init nfs_init_nfspagecache(void);
@@ -419,14 +401,9 @@ extern int nfs_wait_atomic_killable(atomic_t *p, unsigned 
int mode);
 
 /* super.c */
 extern const struct super_operations nfs_sops;
-extern struct file_system_type nfs_fs_type;
-extern struct file_system_type nfs_prepared_fs_type;
-#if IS_ENABLED(CONFIG_NFS_V4)
-extern struct file_system_type nfs4_referral_fs_type;
-#endif
 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
-struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *);
-struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void 
*);
+int nfs_try_get_tree(struct fs_context *);
+int nfs_get_tree_common(struct fs_context *);
 void nfs_kill_super(struct super_block *);
 
 extern struct rpc_stat nfs_rpcstat;
@@ -454,18 +431,13 @@ static inline bool nfs_file_io_is_buffered(struct 
nfs_inode *nfsi)
 extern char *nfs_path(char **p, struct dentry *dentry,
                      char *buffer, ssize_t buflen, unsigned flags);
 extern struct vfsmount *nfs_d_automount(struct path *path);
-struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
-                             struct nfs_fh *, struct nfs_fattr *);
-struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
-                                struct nfs_fattr *, rpc_authflavor_t);
+int nfs_submount(struct fs_context *, struct nfs_server *);
+int nfs_do_submount(struct fs_context *);
 
 /* getroot.c */
-extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
-                                  const char *);
+extern int nfs_get_root(struct super_block *s, struct fs_context *fc);
 #if IS_ENABLED(CONFIG_NFS_V4)
-extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
-                                   const char *);
-
+extern int nfs4_get_root(struct super_block *s, struct fs_context *cfg);
 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, 
bool);
 #endif
 
@@ -484,7 +456,7 @@ int  nfs_show_options(struct seq_file *, struct dentry *);
 int  nfs_show_devname(struct seq_file *, struct dentry *);
 int  nfs_show_path(struct seq_file *, struct dentry *);
 int  nfs_show_stats(struct seq_file *, struct dentry *);
-int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
+int  nfs_reconfigure(struct fs_context *);
 
 /* write.c */
 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 72a99f9c7390..3e566a632215 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -140,31 +140,62 @@ EXPORT_SYMBOL_GPL(nfs_path);
  */
 struct vfsmount *nfs_d_automount(struct path *path)
 {
-       struct vfsmount *mnt;
+       struct nfs_fs_context *ctx;
+       struct fs_context *fc;
+       struct vfsmount *mnt = ERR_PTR(-ENOMEM);
        struct nfs_server *server = NFS_SERVER(d_inode(path->dentry));
-       struct nfs_fh *fh = NULL;
-       struct nfs_fattr *fattr = NULL;
+       struct nfs_client *client = server->nfs_client;
+       int ret;
 
        if (IS_ROOT(path->dentry))
                return ERR_PTR(-ESTALE);
 
-       mnt = ERR_PTR(-ENOMEM);
-       fh = nfs_alloc_fhandle();
-       fattr = nfs_alloc_fattr();
-       if (fh == NULL || fattr == NULL)
-               goto out;
+       /* Open a new filesystem context, transferring parameters from the
+        * parent superblock, including the network namespace.
+        */
+       fc = fs_context_for_submount(&nfs_fs_type, path->dentry);
+       if (IS_ERR(fc))
+               return ERR_CAST(fc);
 
-       mnt = server->nfs_client->rpc_ops->submount(server, path->dentry, fh, 
fattr);
+       ctx = nfs_fc2context(fc);
+       ctx->clone_data.dentry  = path->dentry;
+       ctx->clone_data.sb      = path->dentry->d_sb;
+       ctx->clone_data.fattr   = nfs_alloc_fattr();
+       if (!ctx->clone_data.fattr)
+               goto out_fc;
+
+       if (fc->net_ns != client->cl_net) {
+               put_net(fc->net_ns);
+               fc->net_ns = get_net(client->cl_net);
+       }
+
+       /* for submounts we want the same server; referrals will reassign */
+       memcpy(&ctx->nfs_server.address, &client->cl_addr, client->cl_addrlen);
+       ctx->nfs_server.addrlen = client->cl_addrlen;
+       ctx->nfs_server.port    = server->port;
+
+       ctx->version            = client->rpc_ops->version;
+       ctx->minorversion       = client->cl_minorversion;
+       ctx->nfs_mod            = client->cl_nfs_mod;
+       __module_get(ctx->nfs_mod->owner);
+
+       ret = client->rpc_ops->submount(fc, server);
+       if (ret < 0) {
+               mnt = ERR_PTR(ret);
+               goto out_fc;
+       }
+
+       up_write(&fc->root->d_sb->s_umount);
+       mnt = vfs_create_mount(fc);
        if (IS_ERR(mnt))
-               goto out;
+               goto out_fc;
 
        mntget(mnt); /* prevent immediate expiration */
        mnt_set_expiry(mnt, &nfs_automount_list);
        schedule_delayed_work(&nfs_automount_task, 
nfs_mountpoint_expiry_timeout);
 
-out:
-       nfs_free_fattr(fattr);
-       nfs_free_fhandle(fh);
+out_fc:
+       put_fs_context(fc);
        return mnt;
 }
 
@@ -219,61 +250,62 @@ void nfs_release_automount_timer(void)
  * @authflavor: security flavor to use when performing the mount
  *
  */
-struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
-                                struct nfs_fattr *fattr, rpc_authflavor_t 
authflavor)
+int nfs_do_submount(struct fs_context *fc)
 {
-       struct super_block *sb = dentry->d_sb;
-       struct nfs_clone_mount mountdata = {
-               .sb = sb,
-               .dentry = dentry,
-               .authflavor = authflavor,
-       };
-       struct nfs_mount_info mount_info = {
-               .inherited_bsize = sb->s_blocksize_bits,
-               .cloned = &mountdata,
-               .mntfh = fh,
-               .nfs_mod = NFS_SB(sb)->nfs_client->cl_nfs_mod,
-       };
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct dentry *dentry = ctx->clone_data.dentry;
        struct nfs_server *server;
-       struct vfsmount *mnt;
-       char *page = (char *) __get_free_page(GFP_USER);
-       char *devname;
+       char *buffer, *p;
+       int ret;
 
-       if (page == NULL)
-               return ERR_PTR(-ENOMEM);
+       /* create a new volume representation */
+       server = ctx->nfs_mod->rpc_ops->clone_server(NFS_SB(ctx->clone_data.sb),
+                                                    ctx->mntfh,
+                                                    ctx->clone_data.fattr,
+                                                    ctx->selected_flavor);
 
-       server = mount_info.nfs_mod->rpc_ops->clone_server(NFS_SB(sb), fh,
-                                                          fattr, authflavor);
        if (IS_ERR(server))
-               return ERR_CAST(server);
+               return PTR_ERR(server);
 
-       mount_info.server = server;
+       ctx->server = server;
 
-       devname = nfs_devname(dentry, page, PAGE_SIZE);
-       if (IS_ERR(devname))
-               mnt = ERR_CAST(devname);
-       else
-               mnt = vfs_submount(dentry, &nfs_prepared_fs_type, devname, 
&mount_info);
+       buffer = kmalloc(4096, GFP_USER);
+       if (!buffer)
+               return -ENOMEM;
 
-       if (mount_info.server)
-               nfs_free_server(mount_info.server);
-       free_page((unsigned long)page);
-       return mnt;
+       ctx->internal           = true;
+       ctx->clone_data.inherited_bsize = ctx->clone_data.sb->s_blocksize_bits;
+
+       p = nfs_devname(dentry, buffer, 4096);
+       if (IS_ERR(p)) {
+               dprintk("NFS: Couldn't determine submount pathname\n");
+               ret = PTR_ERR(p);
+       } else {
+               ret = vfs_parse_fs_string(fc, "source", p, buffer + 4096 - p);
+               if (!ret)
+                       ret = vfs_get_tree(fc);
+       }
+       kfree(buffer);
+       return ret;
 }
 EXPORT_SYMBOL_GPL(nfs_do_submount);
 
-struct vfsmount *nfs_submount(struct nfs_server *server, struct dentry *dentry,
-                             struct nfs_fh *fh, struct nfs_fattr *fattr)
+int nfs_submount(struct fs_context *fc, struct nfs_server *server)
 {
-       int err;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct dentry *dentry = ctx->clone_data.dentry;
        struct dentry *parent = dget_parent(dentry);
+       int err;
 
        /* Look it up again to get its attributes */
-       err = server->nfs_client->rpc_ops->lookup(d_inode(parent), 
&dentry->d_name, fh, fattr, NULL);
+       err = server->nfs_client->rpc_ops->lookup(d_inode(parent), 
&dentry->d_name,
+                                                 ctx->mntfh, 
ctx->clone_data.fattr,
+                                                 NULL);
        dput(parent);
        if (err != 0)
-               return ERR_PTR(err);
+               return err;
 
-       return nfs_do_submount(dentry, fh, fattr, 
server->client->cl_auth->au_flavor);
+       ctx->selected_flavor = server->client->cl_auth->au_flavor;
+       return nfs_do_submount(fc);
 }
 EXPORT_SYMBOL_GPL(nfs_submount);
diff --git a/fs/nfs/nfs3_fs.h b/fs/nfs/nfs3_fs.h
index 09602dc1889f..1b950b66b3bb 100644
--- a/fs/nfs/nfs3_fs.h
+++ b/fs/nfs/nfs3_fs.h
@@ -27,7 +27,7 @@ static inline int nfs3_proc_setacls(struct inode *inode, 
struct posix_acl *acl,
 #endif /* CONFIG_NFS_V3_ACL */
 
 /* nfs3client.c */
-struct nfs_server *nfs3_create_server(struct nfs_mount_info *);
+struct nfs_server *nfs3_create_server(struct fs_context *);
 struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
                                     struct nfs_fattr *, rpc_authflavor_t);
 
diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c
index a340b5d0e1a3..bfd9b5f03455 100644
--- a/fs/nfs/nfs3client.c
+++ b/fs/nfs/nfs3client.c
@@ -46,9 +46,10 @@ static inline void nfs_init_server_aclclient(struct 
nfs_server *server)
 }
 #endif
 
-struct nfs_server *nfs3_create_server(struct nfs_mount_info *mount_info)
+struct nfs_server *nfs3_create_server(struct fs_context *fc)
 {
-       struct nfs_server *server = nfs_create_server(mount_info);
+       struct nfs_server *server = nfs_create_server(fc);
+
        /* Create a client RPC handle for the NFS v3 ACL management interface */
        if (!IS_ERR(server))
                nfs_init_server_aclclient(server);
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index a3ad2d46fd42..912a0b0c9bb9 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -963,7 +963,7 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
        .nlmclnt_ops    = &nlmclnt_fl_close_lock_ops,
        .getroot        = nfs3_proc_get_root,
        .submount       = nfs_submount,
-       .try_mount      = nfs_try_mount,
+       .try_get_tree   = nfs_try_get_tree,
        .getattr        = nfs3_proc_getattr,
        .setattr        = nfs3_proc_setattr,
        .lookup         = nfs3_proc_lookup,
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 67ecd7bb512f..a6ee4de47774 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -268,14 +268,13 @@ extern const struct dentry_operations 
nfs4_dentry_operations;
 int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
                    unsigned, umode_t);
 
-/* super.c */
+/* fs_context.c */
 extern struct file_system_type nfs4_fs_type;
 
 /* nfs4namespace.c */
 struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
                                         const struct qstr *);
-struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
-                              struct nfs_fh *, struct nfs_fattr *);
+int nfs4_submount(struct fs_context *, struct nfs_server *);
 int nfs4_replace_transport(struct nfs_server *server,
                                const struct nfs4_fs_locations *locations);
 
@@ -517,7 +516,6 @@ extern const nfs4_stateid invalid_stateid;
 /* nfs4super.c */
 struct nfs_mount_info;
 extern struct nfs_subversion nfs_v4;
-struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *);
 extern bool nfs4_disable_idmapping;
 extern unsigned short max_session_slots;
 extern unsigned short max_session_cb_slots;
@@ -527,6 +525,9 @@ extern bool recover_lost_locks;
 #define NFS4_CLIENT_ID_UNIQ_LEN                (64)
 extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
 
+extern int nfs4_try_get_tree(struct fs_context *);
+extern int nfs4_get_referral_tree(struct fs_context *);
+
 /* nfs4sysctl.c */
 #ifdef CONFIG_SYSCTL
 int nfs4_register_sysctl(void);
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 2ee2281ce404..be26fbe06863 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -1052,9 +1052,9 @@ static int nfs4_server_common_setup(struct nfs_server 
*server,
 /*
  * Create a version 4 volume record
  */
-static int nfs4_init_server(struct nfs_server *server,
-                           struct nfs_fs_context *ctx)
+static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct rpc_timeout timeparms;
        int error;
 
@@ -1076,15 +1076,15 @@ static int nfs4_init_server(struct nfs_server *server,
 
        /* Get a client record */
        error = nfs4_set_client(server,
-                       ctx->nfs_server.hostname,
-                       (const struct sockaddr *)&ctx->nfs_server.address,
-                       ctx->nfs_server.addrlen,
-                       ctx->client_address,
-                       ctx->nfs_server.protocol,
-                       &timeparms,
-                       ctx->minorversion,
-                       ctx->nfs_server.nconnect,
-                       ctx->net);
+                               ctx->nfs_server.hostname,
+                               &ctx->nfs_server.address,
+                               ctx->nfs_server.addrlen,
+                               ctx->client_address,
+                               ctx->nfs_server.protocol,
+                               &timeparms,
+                               ctx->minorversion,
+                               ctx->nfs_server.nconnect,
+                               fc->net_ns);
        if (error < 0)
                return error;
 
@@ -1107,10 +1107,9 @@ static int nfs4_init_server(struct nfs_server *server,
  * Create a version 4 volume record
  * - keyed on server and FSID
  */
-/*struct nfs_server *nfs4_create_server(const struct nfs_fs_context *data,
-                                     struct nfs_fh *mntfh)*/
-struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info)
+struct nfs_server *nfs4_create_server(struct fs_context *fc)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct nfs_server *server;
        bool auth_probe;
        int error;
@@ -1121,14 +1120,14 @@ struct nfs_server *nfs4_create_server(struct 
nfs_mount_info *mount_info)
 
        server->cred = get_cred(current_cred());
 
-       auth_probe = mount_info->ctx->auth_info.flavor_len < 1;
+       auth_probe = ctx->auth_info.flavor_len < 1;
 
        /* set up the general RPC client */
-       error = nfs4_init_server(server, mount_info->ctx);
+       error = nfs4_init_server(server, fc);
        if (error < 0)
                goto error;
 
-       error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
+       error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
        if (error < 0)
                goto error;
 
@@ -1142,9 +1141,9 @@ struct nfs_server *nfs4_create_server(struct 
nfs_mount_info *mount_info)
 /*
  * Create an NFS4 referral server record
  */
-struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
-                                              struct nfs_fh *mntfh)
+struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct nfs_client *parent_client;
        struct nfs_server *server, *parent_server;
        bool auth_probe;
@@ -1154,7 +1153,7 @@ struct nfs_server *nfs4_create_referral_server(struct 
nfs_clone_mount *data,
        if (!server)
                return ERR_PTR(-ENOMEM);
 
-       parent_server = NFS_SB(data->sb);
+       parent_server = NFS_SB(ctx->clone_data.sb);
        parent_client = parent_server->nfs_client;
 
        server->cred = get_cred(parent_server->cred);
@@ -1164,10 +1163,11 @@ struct nfs_server *nfs4_create_referral_server(struct 
nfs_clone_mount *data,
 
        /* Get a client representation */
 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
-       rpc_set_port(data->addr, NFS_RDMA_PORT);
-       error = nfs4_set_client(server, data->hostname,
-                               data->addr,
-                               data->addrlen,
+       rpc_set_port(&ctx->nfs_server.address, NFS_RDMA_PORT);
+       error = nfs4_set_client(server,
+                               ctx->nfs_server.hostname,
+                               &ctx->nfs_server.address,
+                               ctx->nfs_server.addrlen,
                                parent_client->cl_ipaddr,
                                XPRT_TRANSPORT_RDMA,
                                parent_server->client->cl_timeout,
@@ -1178,10 +1178,11 @@ struct nfs_server *nfs4_create_referral_server(struct 
nfs_clone_mount *data,
                goto init_server;
 #endif /* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
 
-       rpc_set_port(data->addr, NFS_PORT);
-       error = nfs4_set_client(server, data->hostname,
-                               data->addr,
-                               data->addrlen,
+       rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
+       error = nfs4_set_client(server,
+                               ctx->nfs_server.hostname,
+                               &ctx->nfs_server.address,
+                               ctx->nfs_server.addrlen,
                                parent_client->cl_ipaddr,
                                XPRT_TRANSPORT_TCP,
                                parent_server->client->cl_timeout,
@@ -1194,13 +1195,14 @@ struct nfs_server *nfs4_create_referral_server(struct 
nfs_clone_mount *data,
 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
 init_server:
 #endif
-       error = nfs_init_server_rpcclient(server, 
parent_server->client->cl_timeout, data->authflavor);
+       error = nfs_init_server_rpcclient(server, 
parent_server->client->cl_timeout,
+                                         ctx->selected_flavor);
        if (error < 0)
                goto error;
 
        auth_probe = parent_server->auth_info.flavor_len < 1;
 
-       error = nfs4_server_common_setup(server, mntfh, auth_probe);
+       error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
        if (error < 0)
                goto error;
 
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 2e460c33ae48..37999925040a 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -8,6 +8,7 @@
  * NFSv4 namespace
  */
 
+#include <linux/module.h>
 #include <linux/dcache.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
@@ -21,37 +22,64 @@
 #include <linux/inet.h>
 #include "internal.h"
 #include "nfs4_fs.h"
+#include "nfs.h"
 #include "dns_resolve.h"
 
 #define NFSDBG_FACILITY                NFSDBG_VFS
 
+/*
+ * Work out the length that an NFSv4 path would render to as a standard posix
+ * path, with a leading slash but no terminating slash.
+ */
+static ssize_t nfs4_pathname_len(const struct nfs4_pathname *pathname)
+{
+       ssize_t len = 0;
+       int i;
+
+       for (i = 0; i < pathname->ncomponents; i++) {
+               const struct nfs4_string *component = &pathname->components[i];
+
+               if (component->len > NAME_MAX)
+                       goto too_long;
+               len += 1 + component->len; /* Adding "/foo" */
+               if (len > PATH_MAX)
+                       goto too_long;
+       }
+       return len;
+
+too_long:
+       return -ENAMETOOLONG;
+}
+
 /*
  * Convert the NFSv4 pathname components into a standard posix path.
- *
- * Note that the resulting string will be placed at the end of the buffer
  */
-static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
-                                        char *buffer, ssize_t buflen)
+static char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
+                                 unsigned short *_len)
 {
-       char *end = buffer + buflen;
-       int n;
+       ssize_t len;
+       char *buf, *p;
+       int i;
+
+       len = nfs4_pathname_len(pathname);
+       if (len < 0)
+               return ERR_PTR(len);
+       *_len = len;
 
-       *--end = '\0';
-       buflen--;
-
-       n = pathname->ncomponents;
-       while (--n >= 0) {
-               const struct nfs4_string *component = &pathname->components[n];
-               buflen -= component->len + 1;
-               if (buflen < 0)
-                       goto Elong;
-               end -= component->len;
-               memcpy(end, component->data, component->len);
-               *--end = '/';
+       p = buf = kmalloc(len + 1, GFP_KERNEL);
+       if (!buf)
+               return ERR_PTR(-ENOMEM);
+
+       for (i = 0; i < pathname->ncomponents; i++) {
+               const struct nfs4_string *component = &pathname->components[i];
+
+               *p++ = '/';
+               memcpy(p, component->data, component->len);
+               p += component->len;
        }
-       return end;
-Elong:
-       return ERR_PTR(-ENAMETOOLONG);
+
+       *p = 0;
+       return buf;
 }
 
 /*
@@ -100,21 +128,25 @@ static char *nfs4_path(struct dentry *dentry, char 
*buffer, ssize_t buflen)
  */
 static int nfs4_validate_fspath(struct dentry *dentry,
                                const struct nfs4_fs_locations *locations,
-                               char *page, char *page2)
+                               struct nfs_fs_context *ctx)
 {
-       const char *path, *fs_path;
+       const char *path;
+       char *buf;
+       int n;
 
-       path = nfs4_path(dentry, page, PAGE_SIZE);
-       if (IS_ERR(path))
+       buf = kmalloc(4096, GFP_KERNEL);
+       path = nfs4_path(dentry, buf, 4096);
+       if (IS_ERR(path)) {
+               kfree(buf);
                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) {
+       n = strncmp(path, ctx->nfs_server.export_path,
+                   ctx->nfs_server.export_path_len);
+       kfree(buf);
+       if (n != 0) {
                dprintk("%s: path %s does not begin with fsroot %s\n",
-                       __func__, path, fs_path);
+                       __func__, path, ctx->nfs_server.export_path);
                return -ENOENT;
        }
 
@@ -236,55 +268,70 @@ nfs4_negotiate_security(struct rpc_clnt *clnt, struct 
inode *inode,
        return new;
 }
 
-static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
-                                    char *page, char *page2,
-                                    const struct nfs4_fs_location *location)
+static int try_location(struct fs_context *fc,
+                       const struct nfs4_fs_location *location)
 {
-       const size_t addr_bufsize = sizeof(struct sockaddr_storage);
-       struct net *net = rpc_net_ns(NFS_SB(mountdata->sb)->client);
-       struct vfsmount *mnt = ERR_PTR(-ENOENT);
-       char *mnt_path;
-       unsigned int maxbuflen;
-       unsigned int s;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       unsigned int len, s;
+       char *source, *p;
+       int ret = -ENOENT;
+
+       /* Allocate a buffer big enough to hold any of the hostnames plus a
+        * terminating char and also a buffer big enough to hold the hostname
+        * plus a colon plus the path.
+        */
+       len = 0;
+       for (s = 0; s < location->nservers; s++) {
+               const struct nfs4_string *buf = &location->servers[s];
+               if (buf->len > len)
+                       len = buf->len;
+       }
 
-       mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
-       if (IS_ERR(mnt_path))
-               return ERR_CAST(mnt_path);
-       mountdata->mnt_path = mnt_path;
-       maxbuflen = mnt_path - 1 - page2;
+       kfree(ctx->nfs_server.hostname);
+       ctx->nfs_server.hostname = kmalloc(len + 1, GFP_KERNEL);
+       if (!ctx->nfs_server.hostname)
+               return -ENOMEM;
 
-       mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
-       if (mountdata->addr == NULL)
-               return ERR_PTR(-ENOMEM);
+       source = kmalloc(len + 1 + ctx->nfs_server.export_path_len + 1,
+                        GFP_KERNEL);
+       if (!source)
+               return -ENOMEM;
 
+       kfree(fc->source);
+       fc->source = source;
        for (s = 0; s < location->nservers; s++) {
                const struct nfs4_string *buf = &location->servers[s];
 
-               if (buf->len <= 0 || buf->len >= maxbuflen)
-                       continue;
-
                if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
                        continue;
 
-               mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
-                               mountdata->addr, addr_bufsize, net);
-               if (mountdata->addrlen == 0)
+               ctx->nfs_server.addrlen =
+                       nfs_parse_server_name(buf->data, buf->len,
+                                             &ctx->nfs_server.address,
+                                             sizeof(ctx->nfs_server._address),
+                                             fc->net_ns);
+               if (ctx->nfs_server.addrlen == 0)
                        continue;
 
-               memcpy(page2, buf->data, buf->len);
-               page2[buf->len] = '\0';
-               mountdata->hostname = page2;
+               rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
 
-               snprintf(page, PAGE_SIZE, "%s:%s",
-                               mountdata->hostname,
-                               mountdata->mnt_path);
+               memcpy(ctx->nfs_server.hostname, buf->data, buf->len);
+               ctx->nfs_server.hostname[buf->len] = '\0';
 
-               mnt = vfs_submount(mountdata->dentry, &nfs4_referral_fs_type, 
page, mountdata);
-               if (!IS_ERR(mnt))
-                       break;
+               p = source;
+               memcpy(p, buf->data, buf->len);
+               p += buf->len;
+               *p++ = ':';
+               memcpy(p, ctx->nfs_server.export_path, 
ctx->nfs_server.export_path_len);
+               p += ctx->nfs_server.export_path_len;
+               *p = 0;
+
+               ret = nfs4_get_referral_tree(fc);
+               if (ret == 0)
+                       return 0;
        }
-       kfree(mountdata->addr);
-       return mnt;
+
+       return ret;
 }
 
 /**
@@ -293,38 +340,31 @@ static struct vfsmount *try_location(struct 
nfs_clone_mount *mountdata,
  * @locations: array of NFSv4 server location information
  *
  */
-static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
-                                           const struct nfs4_fs_locations 
*locations)
+static int nfs_follow_referral(struct fs_context *fc,
+                              const struct nfs4_fs_locations *locations)
 {
-       struct vfsmount *mnt = ERR_PTR(-ENOENT);
-       struct nfs_clone_mount mountdata = {
-               .sb = dentry->d_sb,
-               .dentry = dentry,
-               .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
-       };
-       char *page = NULL, *page2 = NULL;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       char *export_path;
        int loc, error;
 
        if (locations == NULL || locations->nlocations <= 0)
-               goto out;
+               return -ENOENT;
 
-       dprintk("%s: referral at %pd2\n", __func__, dentry);
+       dprintk("%s: referral at %pd2\n", __func__, ctx->clone_data.dentry);
 
-       page = (char *) __get_free_page(GFP_USER);
-       if (!page)
-               goto out;
+       export_path = nfs4_pathname_string(&locations->fs_path,
+                                          &ctx->nfs_server.export_path_len);
+       if (IS_ERR(export_path))
+               return PTR_ERR(export_path);
 
-       page2 = (char *) __get_free_page(GFP_USER);
-       if (!page2)
-               goto out;
+       ctx->nfs_server.export_path = export_path;
 
        /* Ensure fs path is a prefix of current dentry path */
-       error = nfs4_validate_fspath(dentry, locations, page, page2);
-       if (error < 0) {
-               mnt = ERR_PTR(error);
-               goto out;
-       }
+       error = nfs4_validate_fspath(ctx->clone_data.dentry, locations, ctx);
+       if (error < 0)
+               return error;
 
+       error = -ENOENT;
        for (loc = 0; loc < locations->nlocations; loc++) {
                const struct nfs4_fs_location *location = 
&locations->locations[loc];
 
@@ -332,15 +372,12 @@ static struct vfsmount *nfs_follow_referral(struct dentry 
*dentry,
                    location->rootpath.ncomponents == 0)
                        continue;
 
-               mnt = try_location(&mountdata, page, page2, location);
-               if (!IS_ERR(mnt))
-                       break;
+               error = try_location(fc, location);
+               if (error == 0)
+                       return 0;
        }
 
-out:
-       free_page((unsigned long) page);
-       free_page((unsigned long) page2);
-       return mnt;
+       return error;
 }
 
 /*
@@ -348,71 +385,73 @@ static struct vfsmount *nfs_follow_referral(struct dentry 
*dentry,
  * @dentry - dentry of referral
  *
  */
-static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry 
*dentry)
+static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client)
 {
-       struct vfsmount *mnt = ERR_PTR(-ENOMEM);
-       struct dentry *parent;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct dentry *dentry, *parent;
        struct nfs4_fs_locations *fs_locations = NULL;
        struct page *page;
-       int err;
+       int err = -ENOMEM;
 
        /* BUG_ON(IS_ROOT(dentry)); */
        page = alloc_page(GFP_KERNEL);
-       if (page == NULL)
-               return mnt;
+       if (!page)
+               return -ENOMEM;
 
        fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
-       if (fs_locations == NULL)
+       if (!fs_locations)
                goto out_free;
 
        /* Get locations */
-       mnt = ERR_PTR(-ENOENT);
-
+       dentry = ctx->clone_data.dentry;
        parent = dget_parent(dentry);
        dprintk("%s: getting locations for %pd2\n",
                __func__, dentry);
 
        err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, 
fs_locations, page);
        dput(parent);
-       if (err != 0 ||
-           fs_locations->nlocations <= 0 ||
+       if (err != 0)
+               goto out_free_2;
+
+       err = -ENOENT;
+       if (fs_locations->nlocations <= 0 ||
            fs_locations->fs_path.ncomponents <= 0)
-               goto out_free;
+               goto out_free_2;
 
-       mnt = nfs_follow_referral(dentry, fs_locations);
+       err = nfs_follow_referral(fc, fs_locations);
+out_free_2:
+       kfree(fs_locations);
 out_free:
        __free_page(page);
-       kfree(fs_locations);
-       return mnt;
+       return err;
 }
 
-struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry 
*dentry,
-                              struct nfs_fh *fh, struct nfs_fattr *fattr)
+int nfs4_submount(struct fs_context *fc, struct nfs_server *server)
 {
-       rpc_authflavor_t flavor = server->client->cl_auth->au_flavor;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct dentry *dentry = ctx->clone_data.dentry;
        struct dentry *parent = dget_parent(dentry);
        struct inode *dir = d_inode(parent);
        const struct qstr *name = &dentry->d_name;
        struct rpc_clnt *client;
-       struct vfsmount *mnt;
+       int ret;
 
        /* Look it up again to get its attributes and sec flavor */
-       client = nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
+       client = nfs4_proc_lookup_mountpoint(dir, name, ctx->mntfh,
+                                            ctx->clone_data.fattr);
        dput(parent);
        if (IS_ERR(client))
-               return ERR_CAST(client);
+               return PTR_ERR(client);
 
-       if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
-               mnt = nfs_do_refmount(client, dentry);
-               goto out;
+       if (ctx->clone_data.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+               ret = nfs_do_refmount(fc, client);
+       } else {
+               ctx->selected_flavor = client->cl_auth->au_flavor;
+               ret = nfs_do_submount(fc);
        }
 
-       if (client->cl_auth->au_flavor != flavor)
-               flavor = client->cl_auth->au_flavor;
-       mnt = nfs_do_submount(dentry, fh, fattr, flavor);
-out:
        rpc_shutdown_client(client);
-       return mnt;
+       return ret;
 }
 
 /*
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1406858bae6c..2f31ece2f4a4 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -9895,7 +9895,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
        .file_ops       = &nfs4_file_operations,
        .getroot        = nfs4_proc_get_root,
        .submount       = nfs4_submount,
-       .try_mount      = nfs4_try_mount,
+       .try_get_tree   = nfs4_try_get_tree,
        .getattr        = nfs4_proc_getattr,
        .setattr        = nfs4_proc_setattr,
        .lookup         = nfs4_proc_lookup,
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index ca9740137cfe..3b27c5e3d781 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -4,6 +4,7 @@
  */
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/mount.h>
 #include <linux/nfs4_mount.h>
 #include <linux/nfs_fs.h>
 #include "delegation.h"
@@ -18,16 +19,6 @@
 
 static int nfs4_write_inode(struct inode *inode, struct writeback_control 
*wbc);
 static void nfs4_evict_inode(struct inode *inode);
-static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
-       int flags, const char *dev_name, void *raw_data);
-
-struct file_system_type nfs4_referral_fs_type = {
-       .owner          = THIS_MODULE,
-       .name           = "nfs4",
-       .mount          = nfs4_referral_mount,
-       .kill_sb        = nfs_kill_super,
-       .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
-};
 
 static const struct super_operations nfs4_sops = {
        .alloc_inode    = nfs_alloc_inode,
@@ -41,16 +32,15 @@ static const struct super_operations nfs4_sops = {
        .show_devname   = nfs_show_devname,
        .show_path      = nfs_show_path,
        .show_stats     = nfs_show_stats,
-       .remount_fs     = nfs_remount,
 };
 
 struct nfs_subversion nfs_v4 = {
-       .owner = THIS_MODULE,
-       .nfs_fs   = &nfs4_fs_type,
-       .rpc_vers = &nfs_version4,
-       .rpc_ops  = &nfs_v4_clientops,
-       .sops     = &nfs4_sops,
-       .xattr    = nfs4_xattr_handlers,
+       .owner          = THIS_MODULE,
+       .nfs_fs         = &nfs4_fs_type,
+       .rpc_vers       = &nfs_version4,
+       .rpc_ops        = &nfs_v4_clientops,
+       .sops           = &nfs4_sops,
+       .xattr          = nfs4_xattr_handlers,
 };
 
 static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
@@ -147,105 +137,123 @@ static void nfs_referral_loop_unprotect(void)
        kfree(p);
 }
 
-static struct dentry *do_nfs4_mount(struct nfs_server *server, int flags,
-                                   struct nfs_mount_info *info,
-                                   const char *hostname,
-                                   const char *export_path)
+static int do_nfs4_mount(struct nfs_server *server,
+                        struct fs_context *fc,
+                        const char *hostname,
+                        const char *export_path)
 {
+       struct nfs_fs_context *root_ctx;
+       struct fs_context *root_fc;
        struct vfsmount *root_mnt;
        struct dentry *dentry;
-       char *root_devname;
-       int err;
        size_t len;
+       int ret;
+
+       struct fs_parameter param = {
+               .key    = "source",
+               .type   = fs_value_is_string,
+               .dirfd  = -1,
+       };
 
        if (IS_ERR(server))
-               return ERR_CAST(server);
+               return PTR_ERR(server);
 
-       len = strlen(hostname) + 5;
-       root_devname = kmalloc(len, GFP_KERNEL);
-       if (root_devname == NULL) {
+       root_fc = vfs_dup_fs_context(fc);
+       if (IS_ERR(root_fc)) {
                nfs_free_server(server);
-               return ERR_PTR(-ENOMEM);
+               return PTR_ERR(root_fc);
+       }
+       kfree(root_fc->source);
+       root_fc->source = NULL;
+
+       root_ctx = nfs_fc2context(root_fc);
+       root_ctx->internal = true;
+       root_ctx->server = server;
+       /* We leave export_path unset as it's not used to find the root. */
+
+       len = strlen(hostname) + 5;
+       param.string = kmalloc(len, GFP_KERNEL);
+       if (param.string == NULL) {
+               put_fs_context(root_fc);
+               return -ENOMEM;
        }
 
        /* Does hostname needs to be enclosed in brackets? */
        if (strchr(hostname, ':'))
-               snprintf(root_devname, len, "[%s]:/", hostname);
+               param.size = snprintf(param.string, len, "[%s]:/", hostname);
        else
-               snprintf(root_devname, len, "%s:/", hostname);
-       info->server = server;
-       root_mnt = vfs_kern_mount(&nfs_prepared_fs_type, flags, root_devname, 
info);
-       if (info->server)
-               nfs_free_server(info->server);
-       info->server = NULL;
-       kfree(root_devname);
+               param.size = snprintf(param.string, len, "%s:/", hostname);
+       ret = vfs_parse_fs_param(root_fc, &param);
+       kfree(param.string);
+       if (ret < 0) {
+               put_fs_context(root_fc);
+               return ret;
+       }
+       root_mnt = fc_mount(root_fc);
+       put_fs_context(root_fc);
 
        if (IS_ERR(root_mnt))
-               return ERR_CAST(root_mnt);
+               return PTR_ERR(root_mnt);
 
-       err = nfs_referral_loop_protect();
-       if (err) {
+       ret = nfs_referral_loop_protect();
+       if (ret) {
                mntput(root_mnt);
-               return ERR_PTR(err);
+               return ret;
        }
 
        dentry = mount_subtree(root_mnt, export_path);
        nfs_referral_loop_unprotect();
 
-       return dentry;
+       if (IS_ERR(dentry))
+               return PTR_ERR(dentry);
+
+       fc->root = dentry;
+       return 0;
 }
 
-struct dentry *nfs4_try_mount(int flags, const char *dev_name,
-                             struct nfs_mount_info *mount_info)
+int nfs4_try_get_tree(struct fs_context *fc)
 {
-       struct nfs_fs_context *ctx = mount_info->ctx;
-       struct dentry *res;
-
-       dfprintk(MOUNT, "--> nfs4_try_mount()\n");
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       int err;
 
-       res = do_nfs4_mount(nfs4_create_server(mount_info),
-                           flags, mount_info,
-                           ctx->nfs_server.hostname,
-                           ctx->nfs_server.export_path);
+       dfprintk(MOUNT, "--> nfs4_try_get_tree()\n");
 
-       dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
-                PTR_ERR_OR_ZERO(res),
-                IS_ERR(res) ? " [error]" : "");
-       return res;
+       /* We create a mount for the server's root, walk to the requested
+        * location and then create another mount for that.
+        */
+       err= do_nfs4_mount(nfs4_create_server(fc),
+                          fc, ctx->nfs_server.hostname,
+                          ctx->nfs_server.export_path);
+       if (err) {
+               dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err);
+       } else {
+               dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n");
+       }
+       return err;
 }
 
 /*
  * Create an NFS4 server record on referral traversal
  */
-static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data)
+int nfs4_get_referral_tree(struct fs_context *fc)
 {
-       struct nfs_clone_mount *data = raw_data;
-       struct nfs_mount_info mount_info = {
-               .cloned = data,
-               .nfs_mod = &nfs_v4,
-       };
-       struct dentry *res;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       int err;
 
        dprintk("--> nfs4_referral_mount()\n");
 
-       mount_info.mntfh = nfs_alloc_fhandle();
-       if (!mount_info.mntfh)
-               return ERR_PTR(-ENOMEM);
-
-       res = do_nfs4_mount(nfs4_create_referral_server(mount_info.cloned,
-                                                       mount_info.mntfh),
-                           flags, &mount_info, data->hostname, data->mnt_path);
-
-       dprintk("<-- nfs4_referral_mount() = %d%s\n",
-               PTR_ERR_OR_ZERO(res),
-               IS_ERR(res) ? " [error]" : "");
-
-       nfs_free_fhandle(mount_info.mntfh);
-       return res;
+       /* create a new volume representation */
+       err = do_nfs4_mount(nfs4_create_referral_server(fc),
+                           fc, ctx->nfs_server.hostname,
+                           ctx->nfs_server.export_path);
+       if (err) {
+               dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", 
err);
+       } else {
+               dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n");
+       }
+       return err;
 }
 
-
 static int __init init_nfs_v4(void)
 {
        int err;
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 5552fa8b6e12..03b175fd94b9 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -707,7 +707,7 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
        .file_ops       = &nfs_file_operations,
        .getroot        = nfs_proc_get_root,
        .submount       = nfs_submount,
-       .try_mount      = nfs_try_mount,
+       .try_get_tree   = nfs_try_get_tree,
        .getattr        = nfs_proc_getattr,
        .setattr        = nfs_proc_setattr,
        .lookup         = nfs_proc_lookup,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 9aa27093d8b6..60174a30a91a 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -70,28 +70,6 @@
 
 #define NFSDBG_FACILITY                NFSDBG_VFS
 
-static struct dentry *nfs_prepared_mount(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *raw_data);
-
-struct file_system_type nfs_fs_type = {
-       .owner          = THIS_MODULE,
-       .name           = "nfs",
-       .mount          = nfs_fs_mount,
-       .kill_sb        = nfs_kill_super,
-       .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
-};
-MODULE_ALIAS_FS("nfs");
-EXPORT_SYMBOL_GPL(nfs_fs_type);
-
-struct file_system_type nfs_prepared_fs_type = {
-       .owner          = THIS_MODULE,
-       .name           = "nfs",
-       .mount          = nfs_prepared_mount,
-       .kill_sb        = nfs_kill_super,
-       .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
-};
-EXPORT_SYMBOL_GPL(nfs_prepared_fs_type);
-
 const struct super_operations nfs_sops = {
        .alloc_inode    = nfs_alloc_inode,
        .free_inode     = nfs_free_inode,
@@ -104,22 +82,10 @@ const struct super_operations nfs_sops = {
        .show_devname   = nfs_show_devname,
        .show_path      = nfs_show_path,
        .show_stats     = nfs_show_stats,
-       .remount_fs     = nfs_remount,
 };
 EXPORT_SYMBOL_GPL(nfs_sops);
 
 #if IS_ENABLED(CONFIG_NFS_V4)
-struct file_system_type nfs4_fs_type = {
-       .owner          = THIS_MODULE,
-       .name           = "nfs4",
-       .mount          = nfs_fs_mount,
-       .kill_sb        = nfs_kill_super,
-       .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
-};
-MODULE_ALIAS_FS("nfs4");
-MODULE_ALIAS("nfs4");
-EXPORT_SYMBOL_GPL(nfs4_fs_type);
-
 static int __init register_nfs4_fs(void)
 {
        return register_filesystem(&nfs4_fs_type);
@@ -779,11 +745,12 @@ static int nfs_verify_authflavors(struct nfs_fs_context 
*ctx,
  * Use the remote server's MOUNT service to request the NFS file handle
  * corresponding to the provided path.
  */
-static int nfs_request_mount(struct nfs_fs_context *ctx,
+static int nfs_request_mount(struct fs_context *fc,
                             struct nfs_fh *root_fh,
                             rpc_authflavor_t *server_authlist,
                             unsigned int *server_authlist_len)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct nfs_mount_request request = {
                .sap            = (struct sockaddr *)
                                                &ctx->mount_server.address,
@@ -793,7 +760,7 @@ static int nfs_request_mount(struct nfs_fs_context *ctx,
                .noresvport     = ctx->flags & NFS_MOUNT_NORESVPORT,
                .auth_flav_len  = server_authlist_len,
                .auth_flavs     = server_authlist,
-               .net            = ctx->net,
+               .net            = fc->net_ns,
        };
        int status;
 
@@ -838,20 +805,18 @@ static int nfs_request_mount(struct nfs_fs_context *ctx,
        return 0;
 }
 
-static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info 
*mount_info)
+static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        int status;
        unsigned int i;
        bool tried_auth_unix = false;
        bool auth_null_in_list = false;
        struct nfs_server *server = ERR_PTR(-EACCES);
-       struct nfs_fs_context *ctx = mount_info->ctx;
        rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
        unsigned int authlist_len = ARRAY_SIZE(authlist);
-       struct nfs_subversion *nfs_mod = mount_info->nfs_mod;
 
-       status = nfs_request_mount(ctx, mount_info->mntfh, authlist,
-                                       &authlist_len);
+       status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
        if (status)
                return ERR_PTR(status);
 
@@ -865,7 +830,7 @@ static struct nfs_server *nfs_try_mount_request(struct 
nfs_mount_info *mount_inf
                         ctx->selected_flavor);
                if (status)
                        return ERR_PTR(status);
-               return nfs_mod->rpc_ops->create_server(mount_info);
+               return ctx->nfs_mod->rpc_ops->create_server(fc);
        }
 
        /*
@@ -892,7 +857,7 @@ static struct nfs_server *nfs_try_mount_request(struct 
nfs_mount_info *mount_inf
                }
                dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", 
flavor);
                ctx->selected_flavor = flavor;
-               server = nfs_mod->rpc_ops->create_server(mount_info);
+               server = ctx->nfs_mod->rpc_ops->create_server(fc);
                if (!IS_ERR(server))
                        return server;
        }
@@ -908,23 +873,22 @@ static struct nfs_server *nfs_try_mount_request(struct 
nfs_mount_info *mount_inf
        /* Last chance! Try AUTH_UNIX */
        dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", 
RPC_AUTH_UNIX);
        ctx->selected_flavor = RPC_AUTH_UNIX;
-       return nfs_mod->rpc_ops->create_server(mount_info);
+       return ctx->nfs_mod->rpc_ops->create_server(fc);
 }
 
-static struct dentry *nfs_fs_mount_common(int, const char *, struct 
nfs_mount_info *);
-
-struct dentry *nfs_try_mount(int flags, const char *dev_name,
-                            struct nfs_mount_info *mount_info)
+int nfs_try_get_tree(struct fs_context *fc)
 {
-       struct nfs_subversion *nfs_mod = mount_info->nfs_mod;
-       if (mount_info->ctx->need_mount)
-               mount_info->server = nfs_try_mount_request(mount_info);
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+
+       if (ctx->need_mount)
+               ctx->server = nfs_try_mount_request(fc);
        else
-               mount_info->server = 
nfs_mod->rpc_ops->create_server(mount_info);
+               ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
 
-       return nfs_fs_mount_common(flags, dev_name, mount_info);
+       return nfs_get_tree_common(fc);
 }
-EXPORT_SYMBOL_GPL(nfs_try_mount);
+EXPORT_SYMBOL_GPL(nfs_try_get_tree);
+
 
 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
                | NFS_MOUNT_SECURE \
@@ -965,15 +929,11 @@ nfs_compare_remount_data(struct nfs_server *nfss,
        return 0;
 }
 
-int
-nfs_remount(struct super_block *sb, int *flags, char *raw_data)
+int nfs_reconfigure(struct fs_context *fc)
 {
-       int error;
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
+       struct super_block *sb = fc->root->d_sb;
        struct nfs_server *nfss = sb->s_fs_info;
-       struct nfs_fs_context *ctx;
-       struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
-       struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
-       u32 nfsvers = nfss->nfs_client->rpc_ops->version;
 
        sync_filesystem(sb);
 
@@ -983,64 +943,30 @@ nfs_remount(struct super_block *sb, int *flags, char 
*raw_data)
         * ones were explicitly specified. Fall back to legacy behavior and
         * just return success.
         */
-       if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
-           (nfsvers <= 3 && (!options || (options->version >= 1 &&
-                                          options->version <= 6))))
+       if (ctx->skip_reconfig_option_check)
                return 0;
 
-       ctx = nfs_alloc_parsed_mount_data();
-       if (ctx == NULL)
-               return -ENOMEM;
-
-       /* fill out struct with values from existing mount */
-       ctx->flags = nfss->flags;
-       ctx->rsize = nfss->rsize;
-       ctx->wsize = nfss->wsize;
-       ctx->retrans = nfss->client->cl_timeout->to_retries;
-       ctx->selected_flavor = nfss->client->cl_auth->au_flavor;
-       ctx->acregmin = nfss->acregmin / HZ;
-       ctx->acregmax = nfss->acregmax / HZ;
-       ctx->acdirmin = nfss->acdirmin / HZ;
-       ctx->acdirmax = nfss->acdirmax / HZ;
-       ctx->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
-       ctx->nfs_server.port = nfss->port;
-       ctx->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
-       ctx->version = nfsvers;
-       ctx->minorversion = nfss->nfs_client->cl_minorversion;
-       ctx->net = current->nsproxy->net_ns;
-       memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
-               ctx->nfs_server.addrlen);
-
-       /* overwrite those values with any that were specified */
-       error = -EINVAL;
-       if (!nfs_parse_mount_options((char *)options, ctx))
-               goto out;
-
        /*
         * noac is a special case. It implies -o sync, but that's not
-        * necessarily reflected in the mtab options. do_remount_sb
+        * necessarily reflected in the mtab options. reconfigure_super
         * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
         * remount options, so we have to explicitly reset it.
         */
-       if (ctx->flags & NFS_MOUNT_NOAC)
-               *flags |= SB_SYNCHRONOUS;
+       if (ctx->flags & NFS_MOUNT_NOAC) {
+               fc->sb_flags |= SB_SYNCHRONOUS;
+               fc->sb_flags_mask |= SB_SYNCHRONOUS;
+       }
 
        /* compare new mount options with old ones */
-       error = nfs_compare_remount_data(nfss, ctx);
-       if (!error)
-               error = security_sb_remount(sb, ctx->lsm_opts);
-out:
-       nfs_free_parsed_mount_data(ctx);
-       return error;
+       return nfs_compare_remount_data(nfss, ctx);
 }
-EXPORT_SYMBOL_GPL(nfs_remount);
+EXPORT_SYMBOL_GPL(nfs_reconfigure);
 
 /*
  * Finish setting up an NFS superblock
  */
-static void nfs_fill_super(struct super_block *sb, struct nfs_mount_info 
*mount_info)
+static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
 {
-       struct nfs_fs_context *ctx = mount_info->ctx;
        struct nfs_server *server = NFS_SB(sb);
 
        sb->s_blocksize_bits = 0;
@@ -1072,13 +998,14 @@ static void nfs_fill_super(struct super_block *sb, 
struct nfs_mount_info *mount_
        nfs_super_set_maxbytes(sb, server->maxfilesize);
 }
 
-static int nfs_compare_mount_options(const struct super_block *s, const struct 
nfs_server *b, int flags)
+static int nfs_compare_mount_options(const struct super_block *s, const struct 
nfs_server *b,
+                                    const struct fs_context *fc)
 {
        const struct nfs_server *a = s->s_fs_info;
        const struct rpc_clnt *clnt_a = a->client;
        const struct rpc_clnt *clnt_b = b->client;
 
-       if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
+       if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
                goto Ebusy;
        if (a->nfs_client != b->nfs_client)
                goto Ebusy;
@@ -1103,19 +1030,11 @@ static int nfs_compare_mount_options(const struct 
super_block *s, const struct n
        return 0;
 }
 
-struct nfs_sb_mountdata {
-       struct nfs_server *server;
-       int mntflags;
-};
-
-static int nfs_set_super(struct super_block *s, void *data)
+static int nfs_set_super(struct super_block *s, struct fs_context *fc)
 {
-       struct nfs_sb_mountdata *sb_mntdata = data;
-       struct nfs_server *server = sb_mntdata->server;
+       struct nfs_server *server = fc->s_fs_info;
        int ret;
 
-       s->s_flags = sb_mntdata->mntflags;
-       s->s_fs_info = server;
        s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
        ret = set_anon_super(s, server);
        if (ret == 0)
@@ -1180,11 +1099,9 @@ static int nfs_compare_userns(const struct nfs_server 
*old,
        return 1;
 }
 
-static int nfs_compare_super(struct super_block *sb, void *data)
+static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
 {
-       struct nfs_sb_mountdata *sb_mntdata = data;
-       struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
-       int mntflags = sb_mntdata->mntflags;
+       struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
 
        if (!nfs_compare_super_address(old, server))
                return 0;
@@ -1195,13 +1112,12 @@ static int nfs_compare_super(struct super_block *sb, 
void *data)
                return 0;
        if (!nfs_compare_userns(old, server))
                return 0;
-       return nfs_compare_mount_options(sb, server, mntflags);
+       return nfs_compare_mount_options(sb, server, fc);
 }
 
 #ifdef CONFIG_NFS_FSCACHE
 static void nfs_get_cache_cookie(struct super_block *sb,
-                                struct nfs_fs_context *ctx,
-                                struct nfs_clone_mount *cloned)
+                                struct nfs_fs_context *ctx)
 {
        struct nfs_server *nfss = NFS_SB(sb);
        char *uniq = NULL;
@@ -1210,68 +1126,70 @@ static void nfs_get_cache_cookie(struct super_block *sb,
        nfss->fscache_key = NULL;
        nfss->fscache = NULL;
 
-       if (ctx) {
+       if (!ctx)
+               return;
+
+       if (ctx->clone_data.sb) {
+               struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
+               if (!(mnt_s->options & NFS_OPTION_FSCACHE))
+                       return;
+               if (mnt_s->fscache_key) {
+                       uniq = mnt_s->fscache_key->key.uniquifier;
+                       ulen = mnt_s->fscache_key->key.uniq_len;
+               }
+       } else {
                if (!(ctx->options & NFS_OPTION_FSCACHE))
                        return;
                if (ctx->fscache_uniq) {
                        uniq = ctx->fscache_uniq;
                        ulen = strlen(ctx->fscache_uniq);
                }
-       } else if (cloned) {
-               struct nfs_server *mnt_s = NFS_SB(cloned->sb);
-               if (!(mnt_s->options & NFS_OPTION_FSCACHE))
-                       return;
-               if (mnt_s->fscache_key) {
-                       uniq = mnt_s->fscache_key->key.uniquifier;
-                       ulen = mnt_s->fscache_key->key.uniq_len;
-               };
-       } else
                return;
+       }
 
        nfs_fscache_get_super_cookie(sb, uniq, ulen);
 }
 #else
 static void nfs_get_cache_cookie(struct super_block *sb,
-                                struct nfs_fs_context *parsed,
-                                struct nfs_clone_mount *cloned)
+                                struct nfs_fs_context *ctx)
 {
 }
 #endif
 
-static struct dentry *nfs_fs_mount_common(int flags, const char *dev_name,
-                                  struct nfs_mount_info *mount_info)
+int nfs_get_tree_common(struct fs_context *fc)
 {
+       struct nfs_fs_context *ctx = nfs_fc2context(fc);
        struct super_block *s;
-       struct dentry *mntroot = ERR_PTR(-ENOMEM);
-       int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
-       struct nfs_server *server = mount_info->server;
+       int (*compare_super)(struct super_block *, struct fs_context *) = 
nfs_compare_super;
+       struct nfs_server *server = ctx->server;
        unsigned long kflags = 0, kflags_out = 0;
-       struct nfs_sb_mountdata sb_mntdata = {
-               .mntflags = flags,
-               .server = server,
-       };
        int error;
 
-       mount_info->server = NULL;
+       ctx->server = NULL;
        if (IS_ERR(server))
-               return ERR_CAST(server);
+               return PTR_ERR(server);
 
        if (server->flags & NFS_MOUNT_UNSHARED)
                compare_super = NULL;
 
        /* -o noac implies -o sync */
        if (server->flags & NFS_MOUNT_NOAC)
-               sb_mntdata.mntflags |= SB_SYNCHRONOUS;
+               fc->sb_flags |= SB_SYNCHRONOUS;
 
-       if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
-               if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
-                       sb_mntdata.mntflags |= SB_SYNCHRONOUS;
+       if (ctx->clone_data.sb)
+               if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
+                       fc->sb_flags |= SB_SYNCHRONOUS;
+
+       if (server->caps & NFS_CAP_SECURITY_LABEL)
+               fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS;
 
        /* Get a superblock - note that we may end up sharing one that already 
exists */
-       s = sget(mount_info->nfs_mod->nfs_fs, compare_super, nfs_set_super,
-                flags, &sb_mntdata);
+       fc->s_fs_info = server;
+       s = sget_fc(fc, compare_super, nfs_set_super);
+       fc->s_fs_info = NULL;
        if (IS_ERR(s)) {
-               mntroot = ERR_CAST(s);
+               error = PTR_ERR(s);
+               dfprintk(MOUNT, "NFS: Couldn't get superblock\n");
                goto out_err_nosb;
        }
 
@@ -1281,44 +1199,41 @@ static struct dentry *nfs_fs_mount_common(int flags, 
const char *dev_name,
        } else {
                error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
                                             MINOR(server->s_dev));
-               if (error) {
-                       mntroot = ERR_PTR(error);
+               if (error)
                        goto error_splat_super;
-               }
                s->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
                server->super = s;
        }
 
        if (!s->s_root) {
-               unsigned bsize = mount_info->inherited_bsize;
+               unsigned bsize = ctx->clone_data.inherited_bsize;
                /* initial superblock/root creation */
-               nfs_fill_super(s, mount_info);
+               nfs_fill_super(s, ctx);
                if (bsize) {
                        s->s_blocksize_bits = bsize;
                        s->s_blocksize = 1U << bsize;
                }
-               nfs_get_cache_cookie(s, mount_info->ctx, mount_info->cloned);
-               if (!(server->flags & NFS_MOUNT_UNSHARED))
-                       s->s_iflags |= SB_I_MULTIROOT;
+               nfs_get_cache_cookie(s, ctx);
        }
 
-       mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
-       if (IS_ERR(mntroot))
+       error = nfs_get_root(s, fc);
+       if (error < 0) {
+               dfprintk(MOUNT, "NFS: Couldn't get root dentry\n");
                goto error_splat_super;
-
+       }
 
        if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
                kflags |= SECURITY_LSM_NATIVE_LABELS;
-       if (mount_info->cloned) {
-               if (d_inode(mntroot)->i_fop != &nfs_dir_operations) {
+       if (ctx->clone_data.sb) {
+               if (d_inode(fc->root)->i_fop != &nfs_dir_operations) {
                        error = -ESTALE;
                        goto error_splat_root;
                }
                /* clone any lsm security options from the parent to the new sb 
*/
-               error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, 
kflags,
+               error = security_sb_clone_mnt_opts(ctx->clone_data.sb, s, 
kflags,
                                &kflags_out);
        } else {
-               error = security_sb_set_mnt_opts(s, mount_info->ctx->lsm_opts,
+               error = security_sb_set_mnt_opts(s, fc->security,
                                                        kflags, &kflags_out);
        }
        if (error)
@@ -1326,67 +1241,25 @@ static struct dentry *nfs_fs_mount_common(int flags, 
const char *dev_name,
        if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
                !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
                NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
-       if (error)
-               goto error_splat_root;
 
        s->s_flags |= SB_ACTIVE;
+       error = 0;
 
 out:
-       return mntroot;
+       return error;
 
 out_err_nosb:
        nfs_free_server(server);
        goto out;
 
 error_splat_root:
-       dput(mntroot);
-       mntroot = ERR_PTR(error);
+       dput(fc->root);
+       fc->root = NULL;
 error_splat_super:
        deactivate_locked_super(s);
        goto out;
 }
 
-struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
-       int flags, const char *dev_name, void *raw_data)
-{
-       struct nfs_mount_info mount_info = {
-       };
-       struct dentry *mntroot = ERR_PTR(-ENOMEM);
-       struct nfs_subversion *nfs_mod;
-       int error;
-
-       mount_info.ctx = nfs_alloc_parsed_mount_data();
-       mount_info.mntfh = nfs_alloc_fhandle();
-       if (mount_info.ctx == NULL || mount_info.mntfh == NULL)
-               goto out;
-
-       /* Validate the mount data */
-       error = nfs_validate_mount_data(fs_type, raw_data, mount_info.ctx, 
mount_info.mntfh, dev_name);
-       if (error == NFS_TEXT_DATA)
-               error = nfs_validate_text_mount_data(raw_data,
-                                                    mount_info.ctx, dev_name);
-       if (error < 0) {
-               mntroot = ERR_PTR(error);
-               goto out;
-       }
-
-       nfs_mod = get_nfs_version(mount_info.ctx->version);
-       if (IS_ERR(nfs_mod)) {
-               mntroot = ERR_CAST(nfs_mod);
-               goto out;
-       }
-       mount_info.nfs_mod = nfs_mod;
-
-       mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info);
-
-       put_nfs_version(nfs_mod);
-out:
-       nfs_free_parsed_mount_data(mount_info.ctx);
-       nfs_free_fhandle(mount_info.mntfh);
-       return mntroot;
-}
-EXPORT_SYMBOL_GPL(nfs_fs_mount);
-
 /*
  * Destroy an NFS2/3 superblock
  */
@@ -1404,17 +1277,6 @@ void nfs_kill_super(struct super_block *s)
 }
 EXPORT_SYMBOL_GPL(nfs_kill_super);
 
-/*
- * Internal use only: mount_info is already set up by caller.
- * Used for mountpoint crossings and for nfs4 root.
- */
-static struct dentry *
-nfs_prepared_mount(struct file_system_type *fs_type, int flags,
-                  const char *dev_name, void *raw_data)
-{
-       return nfs_fs_mount_common(flags, dev_name, raw_data);
-}
-
 #if IS_ENABLED(CONFIG_NFS_V4)
 
 /*
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 82bdb91da2ae..ed9f215d03ea 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1622,6 +1622,7 @@ struct nfs_subversion;
 struct nfs_mount_info;
 struct nfs_client_initdata;
 struct nfs_pageio_descriptor;
+struct fs_context;
 
 /*
  * RPC procedure vector for NFSv2/NFSv3 demuxing
@@ -1636,9 +1637,8 @@ struct nfs_rpc_ops {
 
        int     (*getroot) (struct nfs_server *, struct nfs_fh *,
                            struct nfs_fsinfo *);
-       struct vfsmount *(*submount) (struct nfs_server *, struct dentry *,
-                                     struct nfs_fh *, struct nfs_fattr *);
-       struct dentry *(*try_mount) (int, const char *, struct nfs_mount_info 
*);
+       int     (*submount) (struct fs_context *, struct nfs_server *);
+       int     (*try_get_tree) (struct fs_context *);
        int     (*getattr) (struct nfs_server *, struct nfs_fh *,
                            struct nfs_fattr *, struct nfs4_label *,
                            struct inode *);
@@ -1705,7 +1705,7 @@ struct nfs_rpc_ops {
        struct nfs_client *(*init_client) (struct nfs_client *,
                                const struct nfs_client_initdata *);
        void    (*free_client) (struct nfs_client *);
-       struct nfs_server *(*create_server)(struct nfs_mount_info *);
+       struct nfs_server *(*create_server)(struct fs_context *);
        struct nfs_server *(*clone_server)(struct nfs_server *, struct nfs_fh *,
                                           struct nfs_fattr *, 
rpc_authflavor_t);
 };
-- 
2.17.2

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