]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blobdiff - fs/nfs/super.c
NFS: Support raw IPv6 address hostnames during NFS mount operation
[mirror_ubuntu-bionic-kernel.git] / fs / nfs / super.c
index 2a4a024a4e7bf09c53575b6ef74398c67779d329..ea4abd266a7a256826ff16922dcd441f7dbd2261 100644 (file)
@@ -65,7 +65,6 @@
 enum {
        /* Mount options that take no arguments */
        Opt_soft, Opt_hard,
-       Opt_intr, Opt_nointr,
        Opt_posix, Opt_noposix,
        Opt_cto, Opt_nocto,
        Opt_ac, Opt_noac,
@@ -101,10 +100,12 @@ enum {
 static match_table_t nfs_mount_option_tokens = {
        { Opt_userspace, "bg" },
        { Opt_userspace, "fg" },
+       { Opt_userspace, "retry=%s" },
+
        { Opt_soft, "soft" },
        { Opt_hard, "hard" },
-       { Opt_intr, "intr" },
-       { Opt_nointr, "nointr" },
+       { Opt_deprecated, "intr" },
+       { Opt_deprecated, "nointr" },
        { Opt_posix, "posix" },
        { Opt_noposix, "noposix" },
        { Opt_cto, "cto" },
@@ -136,7 +137,6 @@ static match_table_t nfs_mount_option_tokens = {
        { Opt_acdirmin, "acdirmin=%u" },
        { Opt_acdirmax, "acdirmax=%u" },
        { Opt_actimeo, "actimeo=%u" },
-       { Opt_userspace, "retry=%u" },
        { Opt_namelen, "namlen=%u" },
        { Opt_mountport, "mountport=%u" },
        { Opt_mountvers, "mountvers=%u" },
@@ -207,6 +207,7 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type,
                int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static void nfs_kill_super(struct super_block *);
 static void nfs_put_super(struct super_block *);
+static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 
 static struct file_system_type nfs_fs_type = {
        .owner          = THIS_MODULE,
@@ -234,6 +235,7 @@ static const struct super_operations nfs_sops = {
        .umount_begin   = nfs_umount_begin,
        .show_options   = nfs_show_options,
        .show_stats     = nfs_show_stats,
+       .remount_fs     = nfs_remount,
 };
 
 #ifdef CONFIG_NFS_V4
@@ -278,6 +280,7 @@ static const struct super_operations nfs4_sops = {
        .umount_begin   = nfs_umount_begin,
        .show_options   = nfs_show_options,
        .show_stats     = nfs_show_stats,
+       .remount_fs     = nfs_remount,
 };
 #endif
 
@@ -783,9 +786,6 @@ static int nfs_parse_mount_options(char *raw,
                case Opt_hard:
                        mnt->flags &= ~NFS_MOUNT_SOFT;
                        break;
-               case Opt_intr:
-               case Opt_nointr:
-                       break;
                case Opt_posix:
                        mnt->flags |= NFS_MOUNT_POSIX;
                        break;
@@ -1101,6 +1101,8 @@ static int nfs_parse_mount_options(char *raw,
 
                case Opt_userspace:
                case Opt_deprecated:
+                       dfprintk(MOUNT, "NFS:   ignoring mount option "
+                                       "'%s'\n", p);
                        break;
 
                default:
@@ -1188,11 +1190,146 @@ static int nfs_try_mount(struct nfs_parsed_mount_data *args,
        if (status == 0)
                return 0;
 
-       dfprintk(MOUNT, "NFS: unable to mount server %s, error %d",
+       dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
                        hostname, status);
        return status;
 }
 
+static int nfs_parse_simple_hostname(const char *dev_name,
+                                    char **hostname, size_t maxnamlen,
+                                    char **export_path, size_t maxpathlen)
+{
+       size_t len;
+       char *colon, *comma;
+
+       colon = strchr(dev_name, ':');
+       if (colon == NULL)
+               goto out_bad_devname;
+
+       len = colon - dev_name;
+       if (len > maxnamlen)
+               goto out_hostname;
+
+       /* N.B. caller will free nfs_server.hostname in all cases */
+       *hostname = kstrndup(dev_name, len, GFP_KERNEL);
+       if (!*hostname)
+               goto out_nomem;
+
+       /* kill possible hostname list: not supported */
+       comma = strchr(*hostname, ',');
+       if (comma != NULL) {
+               if (comma == *hostname)
+                       goto out_bad_devname;
+               *comma = '\0';
+       }
+
+       colon++;
+       len = strlen(colon);
+       if (len > maxpathlen)
+               goto out_path;
+       *export_path = kstrndup(colon, len, GFP_KERNEL);
+       if (!*export_path)
+               goto out_nomem;
+
+       dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
+       return 0;
+
+out_bad_devname:
+       dfprintk(MOUNT, "NFS: device name not in host:path format\n");
+       return -EINVAL;
+
+out_nomem:
+       dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
+       return -ENOMEM;
+
+out_hostname:
+       dfprintk(MOUNT, "NFS: server hostname too long\n");
+       return -ENAMETOOLONG;
+
+out_path:
+       dfprintk(MOUNT, "NFS: export pathname too long\n");
+       return -ENAMETOOLONG;
+}
+
+/*
+ * Hostname has square brackets around it because it contains one or
+ * more colons.  We look for the first closing square bracket, and a
+ * colon must follow it.
+ */
+static int nfs_parse_protected_hostname(const char *dev_name,
+                                       char **hostname, size_t maxnamlen,
+                                       char **export_path, size_t maxpathlen)
+{
+       size_t len;
+       char *start, *end;
+
+       start = (char *)(dev_name + 1);
+
+       end = strchr(start, ']');
+       if (end == NULL)
+               goto out_bad_devname;
+       if (*(end + 1) != ':')
+               goto out_bad_devname;
+
+       len = end - start;
+       if (len > maxnamlen)
+               goto out_hostname;
+
+       /* N.B. caller will free nfs_server.hostname in all cases */
+       *hostname = kstrndup(start, len, GFP_KERNEL);
+       if (*hostname == NULL)
+               goto out_nomem;
+
+       end += 2;
+       len = strlen(end);
+       if (len > maxpathlen)
+               goto out_path;
+       *export_path = kstrndup(end, len, GFP_KERNEL);
+       if (!*export_path)
+               goto out_nomem;
+
+       return 0;
+
+out_bad_devname:
+       dfprintk(MOUNT, "NFS: device name not in host:path format\n");
+       return -EINVAL;
+
+out_nomem:
+       dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
+       return -ENOMEM;
+
+out_hostname:
+       dfprintk(MOUNT, "NFS: server hostname too long\n");
+       return -ENAMETOOLONG;
+
+out_path:
+       dfprintk(MOUNT, "NFS: export pathname too long\n");
+       return -ENAMETOOLONG;
+}
+
+/*
+ * Split "dev_name" 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
+ * bracket, then it may contain colons.
+ *
+ * Note: caller frees hostname and export path, even on error.
+ */
+static int nfs_parse_devname(const char *dev_name,
+                            char **hostname, size_t maxnamlen,
+                            char **export_path, size_t maxpathlen)
+{
+       if (*dev_name == '[')
+               return nfs_parse_protected_hostname(dev_name,
+                                                   hostname, maxnamlen,
+                                                   export_path, maxpathlen);
+
+       return nfs_parse_simple_hostname(dev_name,
+                                        hostname, maxnamlen,
+                                        export_path, maxpathlen);
+}
+
 /*
  * Validate the NFS2/NFS3 mount data
  * - fills in the mount root filehandle
@@ -1216,8 +1353,6 @@ static int nfs_validate_mount_data(void *options,
 {
        struct nfs_mount_data *data = (struct nfs_mount_data *)options;
 
-       memset(args, 0, sizeof(*args));
-
        if (data == NULL)
                goto out_no_data;
 
@@ -1251,13 +1386,13 @@ static int nfs_validate_mount_data(void *options,
        case 5:
                memset(data->context, 0, sizeof(data->context));
        case 6:
-               if (data->flags & NFS_MOUNT_VER3)
+               if (data->flags & NFS_MOUNT_VER3) {
+                       if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
+                               goto out_invalid_fh;
                        mntfh->size = data->root.size;
-               else
+               else
                        mntfh->size = NFS2_FHSIZE;
 
-               if (mntfh->size > sizeof(mntfh->data))
-                       goto out_invalid_fh;
 
                memcpy(mntfh->data, data->root.data, mntfh->size);
                if (mntfh->size < sizeof(mntfh->data))
@@ -1323,8 +1458,6 @@ static int nfs_validate_mount_data(void *options,
 
                break;
        default: {
-               unsigned int len;
-               char *c;
                int status;
 
                if (nfs_parse_mount_options((char *)options, args) == 0)
@@ -1334,21 +1467,17 @@ static int nfs_validate_mount_data(void *options,
                                                &args->nfs_server.address))
                        goto out_no_address;
 
-               c = strchr(dev_name, ':');
-               if (c == NULL)
-                       return -EINVAL;
-               len = c - dev_name;
-               /* N.B. caller will free nfs_server.hostname in all cases */
-               args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
-               if (!args->nfs_server.hostname)
-                       goto out_nomem;
+               status = nfs_parse_devname(dev_name,
+                                          &args->nfs_server.hostname,
+                                          PAGE_SIZE,
+                                          &args->nfs_server.export_path,
+                                          NFS_MAXPATHLEN);
+               if (!status)
+                       status = nfs_try_mount(args, mntfh);
 
-               c++;
-               if (strlen(c) > NFS_MAXPATHLEN)
-                       return -ENAMETOOLONG;
-               args->nfs_server.export_path = c;
+               kfree(args->nfs_server.export_path);
+               args->nfs_server.export_path = NULL;
 
-               status = nfs_try_mount(args, mntfh);
                if (status)
                        return status;
 
@@ -1398,6 +1527,80 @@ out_invalid_fh:
        return -EINVAL;
 }
 
+static int
+nfs_compare_remount_data(struct nfs_server *nfss,
+                        struct nfs_parsed_mount_data *data)
+{
+       if (data->flags != nfss->flags ||
+           data->rsize != nfss->rsize ||
+           data->wsize != nfss->wsize ||
+           data->retrans != nfss->client->cl_timeout->to_retries ||
+           data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
+           data->acregmin != nfss->acregmin / HZ ||
+           data->acregmax != nfss->acregmax / HZ ||
+           data->acdirmin != nfss->acdirmin / HZ ||
+           data->acdirmax != nfss->acdirmax / HZ ||
+           data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
+           data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
+           memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
+                  data->nfs_server.addrlen) != 0)
+               return -EINVAL;
+
+       return 0;
+}
+
+static int
+nfs_remount(struct super_block *sb, int *flags, char *raw_data)
+{
+       int error;
+       struct nfs_server *nfss = sb->s_fs_info;
+       struct nfs_parsed_mount_data *data;
+       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;
+
+       /*
+        * Userspace mount programs that send binary options generally send
+        * them populated with default values. We have no way to know which
+        * ones were explicitly specified. Fall back to legacy behavior and
+        * just return success.
+        */
+       if ((nfsvers == 4 && options4->version == 1) ||
+           (nfsvers <= 3 && options->version >= 1 &&
+            options->version <= 6))
+               return 0;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (data == NULL)
+               return -ENOMEM;
+
+       /* fill out struct with values from existing mount */
+       data->flags = nfss->flags;
+       data->rsize = nfss->rsize;
+       data->wsize = nfss->wsize;
+       data->retrans = nfss->client->cl_timeout->to_retries;
+       data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
+       data->acregmin = nfss->acregmin / HZ;
+       data->acregmax = nfss->acregmax / HZ;
+       data->acdirmin = nfss->acdirmin / HZ;
+       data->acdirmax = nfss->acdirmax / HZ;
+       data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
+       data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
+       memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
+               data->nfs_server.addrlen);
+
+       /* overwrite those values with any that were specified */
+       error = nfs_parse_mount_options((char *)options, data);
+       if (error < 0)
+               goto out;
+
+       /* compare new mount options with old ones */
+       error = nfs_compare_remount_data(nfss, data);
+out:
+       kfree(data);
+       return error;
+}
+
 /*
  * Initialise the common bits of the superblock
  */
@@ -1585,24 +1788,29 @@ static int nfs_get_sb(struct file_system_type *fs_type,
 {
        struct nfs_server *server = NULL;
        struct super_block *s;
-       struct nfs_fh mntfh;
-       struct nfs_parsed_mount_data data;
+       struct nfs_parsed_mount_data *data;
+       struct nfs_fh *mntfh;
        struct dentry *mntroot;
        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
        struct nfs_sb_mountdata sb_mntdata = {
                .mntflags = flags,
        };
-       int error;
+       int error = -ENOMEM;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
+       if (data == NULL || mntfh == NULL)
+               goto out_free_fh;
 
-       security_init_mnt_opts(&data.lsm_opts);
+       security_init_mnt_opts(&data->lsm_opts);
 
        /* Validate the mount data */
-       error = nfs_validate_mount_data(raw_data, &data, &mntfh, dev_name);
+       error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
        if (error < 0)
                goto out;
 
        /* Get a volume representation */
-       server = nfs_create_server(&data, &mntfh);
+       server = nfs_create_server(data, mntfh);
        if (IS_ERR(server)) {
                error = PTR_ERR(server);
                goto out;
@@ -1630,16 +1838,16 @@ static int nfs_get_sb(struct file_system_type *fs_type,
 
        if (!s->s_root) {
                /* initial superblock/root creation */
-               nfs_fill_super(s, &data);
+               nfs_fill_super(s, data);
        }
 
-       mntroot = nfs_get_root(s, &mntfh);
+       mntroot = nfs_get_root(s, mntfh);
        if (IS_ERR(mntroot)) {
                error = PTR_ERR(mntroot);
                goto error_splat_super;
        }
 
-       error = security_sb_set_mnt_opts(s, &data.lsm_opts);
+       error = security_sb_set_mnt_opts(s, &data->lsm_opts);
        if (error)
                goto error_splat_root;
 
@@ -1649,9 +1857,12 @@ static int nfs_get_sb(struct file_system_type *fs_type,
        error = 0;
 
 out:
-       kfree(data.nfs_server.hostname);
-       kfree(data.mount_server.hostname);
-       security_free_mnt_opts(&data.lsm_opts);
+       kfree(data->nfs_server.hostname);
+       kfree(data->mount_server.hostname);
+       security_free_mnt_opts(&data->lsm_opts);
+out_free_fh:
+       kfree(mntfh);
+       kfree(data);
        return error;
 
 out_err_nosb:
@@ -1800,8 +2011,6 @@ static int nfs4_validate_mount_data(void *options,
        struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
        char *c;
 
-       memset(args, 0, sizeof(*args));
-
        if (data == NULL)
                goto out_no_data;
 
@@ -1878,7 +2087,7 @@ static int nfs4_validate_mount_data(void *options,
 
                break;
        default: {
-               unsigned int len;
+               int status;
 
                if (nfs_parse_mount_options((char *)options, args) == 0)
                        return -EINVAL;
@@ -1897,34 +2106,17 @@ static int nfs4_validate_mount_data(void *options,
                        goto out_inval_auth;
                }
 
-               /*
-                * Split "dev_name" into "hostname:mntpath".
-                */
-               c = strchr(dev_name, ':');
-               if (c == NULL)
-                       return -EINVAL;
-               /* while calculating len, pretend ':' is '\0' */
-               len = c - dev_name;
-               if (len > NFS4_MAXNAMLEN)
-                       return -ENAMETOOLONG;
-               /* N.B. caller will free nfs_server.hostname in all cases */
-               args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
-               if (!args->nfs_server.hostname)
-                       goto out_nomem;
-
-               c++;                    /* step over the ':' */
-               len = strlen(c);
-               if (len > NFS4_MAXPATHLEN)
-                       return -ENAMETOOLONG;
-               args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
-               if (!args->nfs_server.export_path)
-                       goto out_nomem;
-
-               dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
-
                if (args->client_address == NULL)
                        goto out_no_client_address;
 
+               status = nfs_parse_devname(dev_name,
+                                          &args->nfs_server.hostname,
+                                          NFS4_MAXNAMLEN,
+                                          &args->nfs_server.export_path,
+                                          NFS4_MAXPATHLEN);
+               if (status < 0)
+                       return status;
+
                break;
                }
        }
@@ -1940,10 +2132,6 @@ out_inval_auth:
                 data->auth_flavourlen);
        return -EINVAL;
 
-out_nomem:
-       dfprintk(MOUNT, "NFS4: not enough memory to handle mount options\n");
-       return -ENOMEM;
-
 out_no_address:
        dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
        return -EINVAL;
@@ -1959,26 +2147,31 @@ out_no_client_address:
 static int nfs4_get_sb(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
 {
-       struct nfs_parsed_mount_data data;
+       struct nfs_parsed_mount_data *data;
        struct super_block *s;
        struct nfs_server *server;
-       struct nfs_fh mntfh;
+       struct nfs_fh *mntfh;
        struct dentry *mntroot;
        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
        struct nfs_sb_mountdata sb_mntdata = {
                .mntflags = flags,
        };
-       int error;
+       int error = -ENOMEM;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
+       if (data == NULL || mntfh == NULL)
+               goto out_free_fh;
 
-       security_init_mnt_opts(&data.lsm_opts);
+       security_init_mnt_opts(&data->lsm_opts);
 
        /* Validate the mount data */
-       error = nfs4_validate_mount_data(raw_data, &data, dev_name);
+       error = nfs4_validate_mount_data(raw_data, data, dev_name);
        if (error < 0)
                goto out;
 
        /* Get a volume representation */
-       server = nfs4_create_server(&data, &mntfh);
+       server = nfs4_create_server(data, mntfh);
        if (IS_ERR(server)) {
                error = PTR_ERR(server);
                goto out;
@@ -2009,13 +2202,13 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
                nfs4_fill_super(s);
        }
 
-       mntroot = nfs4_get_root(s, &mntfh);
+       mntroot = nfs4_get_root(s, mntfh);
        if (IS_ERR(mntroot)) {
                error = PTR_ERR(mntroot);
                goto error_splat_super;
        }
 
-       error = security_sb_set_mnt_opts(s, &data.lsm_opts);
+       error = security_sb_set_mnt_opts(s, &data->lsm_opts);
        if (error)
                goto error_splat_root;
 
@@ -2025,10 +2218,13 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
        error = 0;
 
 out:
-       kfree(data.client_address);
-       kfree(data.nfs_server.export_path);
-       kfree(data.nfs_server.hostname);
-       security_free_mnt_opts(&data.lsm_opts);
+       kfree(data->client_address);
+       kfree(data->nfs_server.export_path);
+       kfree(data->nfs_server.hostname);
+       security_free_mnt_opts(&data->lsm_opts);
+out_free_fh:
+       kfree(mntfh);
+       kfree(data);
        return error;
 
 out_free: