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From: "Schumaker, Anna" <Anna.Schumaker@netapp.com>
To: "smayhew@redhat.com" <smayhew@redhat.com>,
	"trond.myklebust@hammerspace.com"
	<trond.myklebust@hammerspace.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dhowells@redhat.com" <dhowells@redhat.com>
Subject: Re: [PATCH v2 25/26] NFS: Add fs_context support.
Date: Tue, 10 Sep 2019 14:14:47 +0000	[thread overview]
Message-ID: <65578e450e34309a12286f7715c6ed3361aaf4f0.camel@netapp.com> (raw)
In-Reply-To: <20190903203215.9157-26-smayhew@redhat.com>

Hi Scott,

On Tue, 2019-09-03 at 16:32 -0400, Scott Mayhew wrote:
> From: David Howells <dhowells@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 <dhowells@redhat.com>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> Signed-off-by: Scott Mayhew <smayhew@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, 896 insertions(+), 863 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..7284c5a18e2b 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;
> 
> @@ -1157,22 +1043,14 @@ static int nfs23_validate_mount_data(void
> *options,
>         return -EINVAL;
>  }
> 
> -#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)

Can we keep the IS_ENABLED(CONFIG_NFS_V4) define around the
nfs4_parse_monolithic() function? Otherwise, we'll get new defined-but-
not-used warnings when compiling: 

fs/nfs/fs_context.c:1049:12: error: ‘nfs4_parse_monolithic’ defined but
not used [-Werror=unused-function]
 1049 | static int nfs4_parse_monolithic(struct fs_context *fc,
      |            ^~~~~~~~~~~~~~~~~~~~~

Thanks,
Anna

>  {
> +       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 +1100,7 @@ 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 +1120,20 @@ 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;
> 
> @@ -1265,57 +1151,85 @@ static int nfs4_validate_mount_data(void
> *options,
>         return -EINVAL;
>  }
> 
> -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 +1238,219 @@ 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.mn
> tfh),
> -                           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
> 

  reply	other threads:[~2019-09-10 14:17 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-03 20:31 [PATCH v2 00/26] nfs: Mount API conversion Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 01/26] saner calling conventions for nfs_fs_mount_common() Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 02/26] nfs: stash server into struct nfs_mount_info Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 03/26] nfs: lift setting mount_info from nfs4_remote{,_referral}_mount Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 04/26] nfs: fold nfs4_remote_fs_type and nfs4_remote_referral_fs_type Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 05/26] nfs: don't bother setting/restoring export_path around do_nfs_root_mount() Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 06/26] nfs4: fold nfs_do_root_mount/nfs_follow_remote_path Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 07/26] nfs: lift setting mount_info from nfs_xdev_mount() Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 08/26] nfs: stash nfs_subversion reference into nfs_mount_info Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 09/26] nfs: don't bother passing nfs_subversion to ->try_mount() and nfs_fs_mount_common() Scott Mayhew
2019-09-03 20:31 ` [PATCH v2 10/26] nfs: merge xdev and remote file_system_type Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 11/26] nfs: unexport nfs_fs_mount_common() Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 12/26] nfs: don't pass nfs_subversion to ->create_server() Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 13/26] nfs: get rid of mount_info ->fill_super() Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 14/26] nfs_clone_sb_security(): simplify the check for server bogosity Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 15/26] nfs: get rid of ->set_security() Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 16/26] NFS: Move mount parameterisation bits into their own file Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 17/26] NFS: Constify mount argument match tables Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 18/26] NFS: Rename struct nfs_parsed_mount_data to struct nfs_fs_context Scott Mayhew
2019-09-09 18:08   ` Schumaker, Anna
2019-09-03 20:32 ` [PATCH v2 19/26] NFS: Split nfs_parse_mount_options() Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 20/26] NFS: Deindent nfs_fs_context_parse_option() Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 21/26] NFS: Add a small buffer in nfs_fs_context to avoid string dup Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 22/26] NFS: Do some tidying of the parsing code Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 23/26] NFS: rename nfs_fs_context pointer arg in a few functions Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 24/26] NFS: Convert mount option parsing to use functionality from fs_parser.h Scott Mayhew
2019-09-03 20:32 ` [PATCH v2 25/26] NFS: Add fs_context support Scott Mayhew
2019-09-10 14:14   ` Schumaker, Anna [this message]
2019-09-03 20:32 ` [PATCH v2 26/26] NFS: Attach supplementary error information to fs_context Scott Mayhew

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