linux/fs/nfs/super.c
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   1/*
   2 *  linux/fs/nfs/super.c
   3 *
   4 *  Copyright (C) 1992  Rick Sladkey
   5 *
   6 *  nfs superblock handling functions
   7 *
   8 *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9 *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10 *
  11 *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12 *  J.S.Peatfield@damtp.cam.ac.uk
  13 *
  14 *  Split from inode.c by David Howells <dhowells@redhat.com>
  15 *
  16 * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17 *   particular server are held in the same superblock
  18 * - NFS superblocks can have several effective roots to the dentry tree
  19 * - directory type roots are spliced into the tree when a path from one root reaches the root
  20 *   of another (see nfs_lookup())
  21 */
  22
  23#include <linux/module.h>
  24#include <linux/init.h>
  25
  26#include <linux/time.h>
  27#include <linux/kernel.h>
  28#include <linux/mm.h>
  29#include <linux/string.h>
  30#include <linux/stat.h>
  31#include <linux/errno.h>
  32#include <linux/unistd.h>
  33#include <linux/sunrpc/clnt.h>
  34#include <linux/sunrpc/stats.h>
  35#include <linux/sunrpc/metrics.h>
  36#include <linux/sunrpc/xprtsock.h>
  37#include <linux/sunrpc/xprtrdma.h>
  38#include <linux/nfs_fs.h>
  39#include <linux/nfs_mount.h>
  40#include <linux/nfs4_mount.h>
  41#include <linux/lockd/bind.h>
  42#include <linux/smp_lock.h>
  43#include <linux/seq_file.h>
  44#include <linux/mount.h>
  45#include <linux/mnt_namespace.h>
  46#include <linux/namei.h>
  47#include <linux/nfs_idmap.h>
  48#include <linux/vfs.h>
  49#include <linux/inet.h>
  50#include <linux/in6.h>
  51#include <net/ipv6.h>
  52#include <linux/netdevice.h>
  53#include <linux/nfs_xdr.h>
  54#include <linux/magic.h>
  55#include <linux/parser.h>
  56
  57#include <asm/system.h>
  58#include <asm/uaccess.h>
  59
  60#include "nfs4_fs.h"
  61#include "callback.h"
  62#include "delegation.h"
  63#include "iostat.h"
  64#include "internal.h"
  65#include "fscache.h"
  66
  67#define NFSDBG_FACILITY         NFSDBG_VFS
  68
  69enum {
  70        /* Mount options that take no arguments */
  71        Opt_soft, Opt_hard,
  72        Opt_posix, Opt_noposix,
  73        Opt_cto, Opt_nocto,
  74        Opt_ac, Opt_noac,
  75        Opt_lock, Opt_nolock,
  76        Opt_v2, Opt_v3, Opt_v4,
  77        Opt_udp, Opt_tcp, Opt_rdma,
  78        Opt_acl, Opt_noacl,
  79        Opt_rdirplus, Opt_nordirplus,
  80        Opt_sharecache, Opt_nosharecache,
  81        Opt_resvport, Opt_noresvport,
  82        Opt_fscache, Opt_nofscache,
  83
  84        /* Mount options that take integer arguments */
  85        Opt_port,
  86        Opt_rsize, Opt_wsize, Opt_bsize,
  87        Opt_timeo, Opt_retrans,
  88        Opt_acregmin, Opt_acregmax,
  89        Opt_acdirmin, Opt_acdirmax,
  90        Opt_actimeo,
  91        Opt_namelen,
  92        Opt_mountport,
  93        Opt_mountvers,
  94        Opt_nfsvers,
  95        Opt_minorversion,
  96
  97        /* Mount options that take string arguments */
  98        Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
  99        Opt_addr, Opt_mountaddr, Opt_clientaddr,
 100        Opt_lookupcache,
 101        Opt_fscache_uniq,
 102
 103        /* Special mount options */
 104        Opt_userspace, Opt_deprecated, Opt_sloppy,
 105
 106        Opt_err
 107};
 108
 109static const match_table_t nfs_mount_option_tokens = {
 110        { Opt_userspace, "bg" },
 111        { Opt_userspace, "fg" },
 112        { Opt_userspace, "retry=%s" },
 113
 114        { Opt_sloppy, "sloppy" },
 115
 116        { Opt_soft, "soft" },
 117        { Opt_hard, "hard" },
 118        { Opt_deprecated, "intr" },
 119        { Opt_deprecated, "nointr" },
 120        { Opt_posix, "posix" },
 121        { Opt_noposix, "noposix" },
 122        { Opt_cto, "cto" },
 123        { Opt_nocto, "nocto" },
 124        { Opt_ac, "ac" },
 125        { Opt_noac, "noac" },
 126        { Opt_lock, "lock" },
 127        { Opt_nolock, "nolock" },
 128        { Opt_v2, "v2" },
 129        { Opt_v3, "v3" },
 130        { Opt_v4, "v4" },
 131        { Opt_udp, "udp" },
 132        { Opt_tcp, "tcp" },
 133        { Opt_rdma, "rdma" },
 134        { Opt_acl, "acl" },
 135        { Opt_noacl, "noacl" },
 136        { Opt_rdirplus, "rdirplus" },
 137        { Opt_nordirplus, "nordirplus" },
 138        { Opt_sharecache, "sharecache" },
 139        { Opt_nosharecache, "nosharecache" },
 140        { Opt_resvport, "resvport" },
 141        { Opt_noresvport, "noresvport" },
 142        { Opt_fscache, "fsc" },
 143        { Opt_fscache_uniq, "fsc=%s" },
 144        { Opt_nofscache, "nofsc" },
 145
 146        { Opt_port, "port=%s" },
 147        { Opt_rsize, "rsize=%s" },
 148        { Opt_wsize, "wsize=%s" },
 149        { Opt_bsize, "bsize=%s" },
 150        { Opt_timeo, "timeo=%s" },
 151        { Opt_retrans, "retrans=%s" },
 152        { Opt_acregmin, "acregmin=%s" },
 153        { Opt_acregmax, "acregmax=%s" },
 154        { Opt_acdirmin, "acdirmin=%s" },
 155        { Opt_acdirmax, "acdirmax=%s" },
 156        { Opt_actimeo, "actimeo=%s" },
 157        { Opt_namelen, "namlen=%s" },
 158        { Opt_mountport, "mountport=%s" },
 159        { Opt_mountvers, "mountvers=%s" },
 160        { Opt_nfsvers, "nfsvers=%s" },
 161        { Opt_nfsvers, "vers=%s" },
 162        { Opt_minorversion, "minorversion=%s" },
 163
 164        { Opt_sec, "sec=%s" },
 165        { Opt_proto, "proto=%s" },
 166        { Opt_mountproto, "mountproto=%s" },
 167        { Opt_addr, "addr=%s" },
 168        { Opt_clientaddr, "clientaddr=%s" },
 169        { Opt_mounthost, "mounthost=%s" },
 170        { Opt_mountaddr, "mountaddr=%s" },
 171
 172        { Opt_lookupcache, "lookupcache=%s" },
 173
 174        { Opt_err, NULL }
 175};
 176
 177enum {
 178        Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 179
 180        Opt_xprt_err
 181};
 182
 183static const match_table_t nfs_xprt_protocol_tokens = {
 184        { Opt_xprt_udp, "udp" },
 185        { Opt_xprt_tcp, "tcp" },
 186        { Opt_xprt_rdma, "rdma" },
 187
 188        { Opt_xprt_err, NULL }
 189};
 190
 191enum {
 192        Opt_sec_none, Opt_sec_sys,
 193        Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 194        Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 195        Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 196
 197        Opt_sec_err
 198};
 199
 200static const match_table_t nfs_secflavor_tokens = {
 201        { Opt_sec_none, "none" },
 202        { Opt_sec_none, "null" },
 203        { Opt_sec_sys, "sys" },
 204
 205        { Opt_sec_krb5, "krb5" },
 206        { Opt_sec_krb5i, "krb5i" },
 207        { Opt_sec_krb5p, "krb5p" },
 208
 209        { Opt_sec_lkey, "lkey" },
 210        { Opt_sec_lkeyi, "lkeyi" },
 211        { Opt_sec_lkeyp, "lkeyp" },
 212
 213        { Opt_sec_spkm, "spkm3" },
 214        { Opt_sec_spkmi, "spkm3i" },
 215        { Opt_sec_spkmp, "spkm3p" },
 216
 217        { Opt_sec_err, NULL }
 218};
 219
 220enum {
 221        Opt_lookupcache_all, Opt_lookupcache_positive,
 222        Opt_lookupcache_none,
 223
 224        Opt_lookupcache_err
 225};
 226
 227static match_table_t nfs_lookupcache_tokens = {
 228        { Opt_lookupcache_all, "all" },
 229        { Opt_lookupcache_positive, "pos" },
 230        { Opt_lookupcache_positive, "positive" },
 231        { Opt_lookupcache_none, "none" },
 232
 233        { Opt_lookupcache_err, NULL }
 234};
 235
 236
 237static void nfs_umount_begin(struct super_block *);
 238static int  nfs_statfs(struct dentry *, struct kstatfs *);
 239static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 240static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 241static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 242static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 243                int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 244static void nfs_kill_super(struct super_block *);
 245static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 246
 247static struct file_system_type nfs_fs_type = {
 248        .owner          = THIS_MODULE,
 249        .name           = "nfs",
 250        .get_sb         = nfs_get_sb,
 251        .kill_sb        = nfs_kill_super,
 252        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 253};
 254
 255struct file_system_type nfs_xdev_fs_type = {
 256        .owner          = THIS_MODULE,
 257        .name           = "nfs",
 258        .get_sb         = nfs_xdev_get_sb,
 259        .kill_sb        = nfs_kill_super,
 260        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 261};
 262
 263static const struct super_operations nfs_sops = {
 264        .alloc_inode    = nfs_alloc_inode,
 265        .destroy_inode  = nfs_destroy_inode,
 266        .write_inode    = nfs_write_inode,
 267        .statfs         = nfs_statfs,
 268        .clear_inode    = nfs_clear_inode,
 269        .umount_begin   = nfs_umount_begin,
 270        .show_options   = nfs_show_options,
 271        .show_stats     = nfs_show_stats,
 272        .remount_fs     = nfs_remount,
 273};
 274
 275#ifdef CONFIG_NFS_V4
 276static int nfs4_validate_text_mount_data(void *options,
 277        struct nfs_parsed_mount_data *args, const char *dev_name);
 278static int nfs4_try_mount(int flags, const char *dev_name,
 279        struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
 280static int nfs4_get_sb(struct file_system_type *fs_type,
 281        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 282static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 283        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 284static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 285        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 286static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 287        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 288static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
 289        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 290static void nfs4_kill_super(struct super_block *sb);
 291
 292static struct file_system_type nfs4_fs_type = {
 293        .owner          = THIS_MODULE,
 294        .name           = "nfs4",
 295        .get_sb         = nfs4_get_sb,
 296        .kill_sb        = nfs4_kill_super,
 297        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 298};
 299
 300static struct file_system_type nfs4_remote_fs_type = {
 301        .owner          = THIS_MODULE,
 302        .name           = "nfs4",
 303        .get_sb         = nfs4_remote_get_sb,
 304        .kill_sb        = nfs4_kill_super,
 305        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 306};
 307
 308struct file_system_type nfs4_xdev_fs_type = {
 309        .owner          = THIS_MODULE,
 310        .name           = "nfs4",
 311        .get_sb         = nfs4_xdev_get_sb,
 312        .kill_sb        = nfs4_kill_super,
 313        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 314};
 315
 316static struct file_system_type nfs4_remote_referral_fs_type = {
 317        .owner          = THIS_MODULE,
 318        .name           = "nfs4",
 319        .get_sb         = nfs4_remote_referral_get_sb,
 320        .kill_sb        = nfs4_kill_super,
 321        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 322};
 323
 324struct file_system_type nfs4_referral_fs_type = {
 325        .owner          = THIS_MODULE,
 326        .name           = "nfs4",
 327        .get_sb         = nfs4_referral_get_sb,
 328        .kill_sb        = nfs4_kill_super,
 329        .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 330};
 331
 332static const struct super_operations nfs4_sops = {
 333        .alloc_inode    = nfs_alloc_inode,
 334        .destroy_inode  = nfs_destroy_inode,
 335        .write_inode    = nfs_write_inode,
 336        .statfs         = nfs_statfs,
 337        .clear_inode    = nfs4_clear_inode,
 338        .umount_begin   = nfs_umount_begin,
 339        .show_options   = nfs_show_options,
 340        .show_stats     = nfs_show_stats,
 341        .remount_fs     = nfs_remount,
 342};
 343#endif
 344
 345static struct shrinker acl_shrinker = {
 346        .shrink         = nfs_access_cache_shrinker,
 347        .seeks          = DEFAULT_SEEKS,
 348};
 349
 350/*
 351 * Register the NFS filesystems
 352 */
 353int __init register_nfs_fs(void)
 354{
 355        int ret;
 356
 357        ret = register_filesystem(&nfs_fs_type);
 358        if (ret < 0)
 359                goto error_0;
 360
 361        ret = nfs_register_sysctl();
 362        if (ret < 0)
 363                goto error_1;
 364#ifdef CONFIG_NFS_V4
 365        ret = register_filesystem(&nfs4_fs_type);
 366        if (ret < 0)
 367                goto error_2;
 368#endif
 369        register_shrinker(&acl_shrinker);
 370        return 0;
 371
 372#ifdef CONFIG_NFS_V4
 373error_2:
 374        nfs_unregister_sysctl();
 375#endif
 376error_1:
 377        unregister_filesystem(&nfs_fs_type);
 378error_0:
 379        return ret;
 380}
 381
 382/*
 383 * Unregister the NFS filesystems
 384 */
 385void __exit unregister_nfs_fs(void)
 386{
 387        unregister_shrinker(&acl_shrinker);
 388#ifdef CONFIG_NFS_V4
 389        unregister_filesystem(&nfs4_fs_type);
 390#endif
 391        nfs_unregister_sysctl();
 392        unregister_filesystem(&nfs_fs_type);
 393}
 394
 395void nfs_sb_active(struct super_block *sb)
 396{
 397        struct nfs_server *server = NFS_SB(sb);
 398
 399        if (atomic_inc_return(&server->active) == 1)
 400                atomic_inc(&sb->s_active);
 401}
 402
 403void nfs_sb_deactive(struct super_block *sb)
 404{
 405        struct nfs_server *server = NFS_SB(sb);
 406
 407        if (atomic_dec_and_test(&server->active))
 408                deactivate_super(sb);
 409}
 410
 411/*
 412 * Deliver file system statistics to userspace
 413 */
 414static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 415{
 416        struct nfs_server *server = NFS_SB(dentry->d_sb);
 417        unsigned char blockbits;
 418        unsigned long blockres;
 419        struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 420        struct nfs_fattr fattr;
 421        struct nfs_fsstat res = {
 422                        .fattr = &fattr,
 423        };
 424        int error;
 425
 426        error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 427        if (error < 0)
 428                goto out_err;
 429        buf->f_type = NFS_SUPER_MAGIC;
 430
 431        /*
 432         * Current versions of glibc do not correctly handle the
 433         * case where f_frsize != f_bsize.  Eventually we want to
 434         * report the value of wtmult in this field.
 435         */
 436        buf->f_frsize = dentry->d_sb->s_blocksize;
 437
 438        /*
 439         * On most *nix systems, f_blocks, f_bfree, and f_bavail
 440         * are reported in units of f_frsize.  Linux hasn't had
 441         * an f_frsize field in its statfs struct until recently,
 442         * thus historically Linux's sys_statfs reports these
 443         * fields in units of f_bsize.
 444         */
 445        buf->f_bsize = dentry->d_sb->s_blocksize;
 446        blockbits = dentry->d_sb->s_blocksize_bits;
 447        blockres = (1 << blockbits) - 1;
 448        buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 449        buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 450        buf->f_bavail = (res.abytes + blockres) >> blockbits;
 451
 452        buf->f_files = res.tfiles;
 453        buf->f_ffree = res.afiles;
 454
 455        buf->f_namelen = server->namelen;
 456
 457        return 0;
 458
 459 out_err:
 460        dprintk("%s: statfs error = %d\n", __func__, -error);
 461        return error;
 462}
 463
 464/*
 465 * Map the security flavour number to a name
 466 */
 467static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 468{
 469        static const struct {
 470                rpc_authflavor_t flavour;
 471                const char *str;
 472        } sec_flavours[] = {
 473                { RPC_AUTH_NULL, "null" },
 474                { RPC_AUTH_UNIX, "sys" },
 475                { RPC_AUTH_GSS_KRB5, "krb5" },
 476                { RPC_AUTH_GSS_KRB5I, "krb5i" },
 477                { RPC_AUTH_GSS_KRB5P, "krb5p" },
 478                { RPC_AUTH_GSS_LKEY, "lkey" },
 479                { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 480                { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 481                { RPC_AUTH_GSS_SPKM, "spkm" },
 482                { RPC_AUTH_GSS_SPKMI, "spkmi" },
 483                { RPC_AUTH_GSS_SPKMP, "spkmp" },
 484                { UINT_MAX, "unknown" }
 485        };
 486        int i;
 487
 488        for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 489                if (sec_flavours[i].flavour == flavour)
 490                        break;
 491        }
 492        return sec_flavours[i].str;
 493}
 494
 495static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 496                                    int showdefaults)
 497{
 498        struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 499
 500        switch (sap->sa_family) {
 501        case AF_INET: {
 502                struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 503                seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 504                break;
 505        }
 506        case AF_INET6: {
 507                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 508                seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 509                break;
 510        }
 511        default:
 512                if (showdefaults)
 513                        seq_printf(m, ",mountaddr=unspecified");
 514        }
 515
 516        if (nfss->mountd_version || showdefaults)
 517                seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 518        if (nfss->mountd_port || showdefaults)
 519                seq_printf(m, ",mountport=%u", nfss->mountd_port);
 520
 521        switch (nfss->mountd_protocol) {
 522        case IPPROTO_UDP:
 523                seq_printf(m, ",mountproto=udp");
 524                break;
 525        case IPPROTO_TCP:
 526                seq_printf(m, ",mountproto=tcp");
 527                break;
 528        default:
 529                if (showdefaults)
 530                        seq_printf(m, ",mountproto=auto");
 531        }
 532}
 533
 534/*
 535 * Describe the mount options in force on this server representation
 536 */
 537static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 538                                   int showdefaults)
 539{
 540        static const struct proc_nfs_info {
 541                int flag;
 542                const char *str;
 543                const char *nostr;
 544        } nfs_info[] = {
 545                { NFS_MOUNT_SOFT, ",soft", ",hard" },
 546                { NFS_MOUNT_POSIX, ",posix", "" },
 547                { NFS_MOUNT_NOCTO, ",nocto", "" },
 548                { NFS_MOUNT_NOAC, ",noac", "" },
 549                { NFS_MOUNT_NONLM, ",nolock", "" },
 550                { NFS_MOUNT_NOACL, ",noacl", "" },
 551                { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 552                { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 553                { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 554                { 0, NULL, NULL }
 555        };
 556        const struct proc_nfs_info *nfs_infop;
 557        struct nfs_client *clp = nfss->nfs_client;
 558        u32 version = clp->rpc_ops->version;
 559
 560        seq_printf(m, ",vers=%u", version);
 561        seq_printf(m, ",rsize=%u", nfss->rsize);
 562        seq_printf(m, ",wsize=%u", nfss->wsize);
 563        if (nfss->bsize != 0)
 564                seq_printf(m, ",bsize=%u", nfss->bsize);
 565        seq_printf(m, ",namlen=%u", nfss->namelen);
 566        if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 567                seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 568        if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 569                seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 570        if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 571                seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 572        if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 573                seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 574        for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 575                if (nfss->flags & nfs_infop->flag)
 576                        seq_puts(m, nfs_infop->str);
 577                else
 578                        seq_puts(m, nfs_infop->nostr);
 579        }
 580        seq_printf(m, ",proto=%s",
 581                   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 582        if (version == 4) {
 583                if (nfss->port != NFS_PORT)
 584                        seq_printf(m, ",port=%u", nfss->port);
 585        } else
 586                if (nfss->port)
 587                        seq_printf(m, ",port=%u", nfss->port);
 588
 589        seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 590        seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 591        seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 592
 593        if (version != 4)
 594                nfs_show_mountd_options(m, nfss, showdefaults);
 595
 596#ifdef CONFIG_NFS_V4
 597        if (clp->rpc_ops->version == 4)
 598                seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 599#endif
 600        if (nfss->options & NFS_OPTION_FSCACHE)
 601                seq_printf(m, ",fsc");
 602}
 603
 604/*
 605 * Describe the mount options on this VFS mountpoint
 606 */
 607static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 608{
 609        struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 610
 611        nfs_show_mount_options(m, nfss, 0);
 612
 613        seq_printf(m, ",addr=%s",
 614                        rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 615                                                        RPC_DISPLAY_ADDR));
 616
 617        return 0;
 618}
 619
 620/*
 621 * Present statistical information for this VFS mountpoint
 622 */
 623static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 624{
 625        int i, cpu;
 626        struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 627        struct rpc_auth *auth = nfss->client->cl_auth;
 628        struct nfs_iostats totals = { };
 629
 630        seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 631
 632        /*
 633         * Display all mount option settings
 634         */
 635        seq_printf(m, "\n\topts:\t");
 636        seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 637        seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 638        seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 639        seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 640        nfs_show_mount_options(m, nfss, 1);
 641
 642        seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 643
 644        seq_printf(m, "\n\tcaps:\t");
 645        seq_printf(m, "caps=0x%x", nfss->caps);
 646        seq_printf(m, ",wtmult=%u", nfss->wtmult);
 647        seq_printf(m, ",dtsize=%u", nfss->dtsize);
 648        seq_printf(m, ",bsize=%u", nfss->bsize);
 649        seq_printf(m, ",namlen=%u", nfss->namelen);
 650
 651#ifdef CONFIG_NFS_V4
 652        if (nfss->nfs_client->rpc_ops->version == 4) {
 653                seq_printf(m, "\n\tnfsv4:\t");
 654                seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 655                seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 656                seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 657        }
 658#endif
 659
 660        /*
 661         * Display security flavor in effect for this mount
 662         */
 663        seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 664        if (auth->au_flavor)
 665                seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 666
 667        /*
 668         * Display superblock I/O counters
 669         */
 670        for_each_possible_cpu(cpu) {
 671                struct nfs_iostats *stats;
 672
 673                preempt_disable();
 674                stats = per_cpu_ptr(nfss->io_stats, cpu);
 675
 676                for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 677                        totals.events[i] += stats->events[i];
 678                for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 679                        totals.bytes[i] += stats->bytes[i];
 680#ifdef CONFIG_NFS_FSCACHE
 681                for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 682                        totals.fscache[i] += stats->fscache[i];
 683#endif
 684
 685                preempt_enable();
 686        }
 687
 688        seq_printf(m, "\n\tevents:\t");
 689        for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 690                seq_printf(m, "%lu ", totals.events[i]);
 691        seq_printf(m, "\n\tbytes:\t");
 692        for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 693                seq_printf(m, "%Lu ", totals.bytes[i]);
 694#ifdef CONFIG_NFS_FSCACHE
 695        if (nfss->options & NFS_OPTION_FSCACHE) {
 696                seq_printf(m, "\n\tfsc:\t");
 697                for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 698                        seq_printf(m, "%Lu ", totals.bytes[i]);
 699        }
 700#endif
 701        seq_printf(m, "\n");
 702
 703        rpc_print_iostats(m, nfss->client);
 704
 705        return 0;
 706}
 707
 708/*
 709 * Begin unmount by attempting to remove all automounted mountpoints we added
 710 * in response to xdev traversals and referrals
 711 */
 712static void nfs_umount_begin(struct super_block *sb)
 713{
 714        struct nfs_server *server;
 715        struct rpc_clnt *rpc;
 716
 717        lock_kernel();
 718
 719        server = NFS_SB(sb);
 720        /* -EIO all pending I/O */
 721        rpc = server->client_acl;
 722        if (!IS_ERR(rpc))
 723                rpc_killall_tasks(rpc);
 724        rpc = server->client;
 725        if (!IS_ERR(rpc))
 726                rpc_killall_tasks(rpc);
 727
 728        unlock_kernel();
 729}
 730
 731static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 732{
 733        struct nfs_parsed_mount_data *data;
 734
 735        data = kzalloc(sizeof(*data), GFP_KERNEL);
 736        if (data) {
 737                data->rsize             = NFS_MAX_FILE_IO_SIZE;
 738                data->wsize             = NFS_MAX_FILE_IO_SIZE;
 739                data->acregmin          = NFS_DEF_ACREGMIN;
 740                data->acregmax          = NFS_DEF_ACREGMAX;
 741                data->acdirmin          = NFS_DEF_ACDIRMIN;
 742                data->acdirmax          = NFS_DEF_ACDIRMAX;
 743                data->mount_server.port = NFS_UNSPEC_PORT;
 744                data->nfs_server.port   = NFS_UNSPEC_PORT;
 745                data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 746                data->auth_flavors[0]   = RPC_AUTH_UNIX;
 747                data->auth_flavor_len   = 1;
 748                data->version           = version;
 749                data->minorversion      = 0;
 750        }
 751        return data;
 752}
 753
 754/*
 755 * Sanity-check a server address provided by the mount command.
 756 *
 757 * Address family must be initialized, and address must not be
 758 * the ANY address for that family.
 759 */
 760static int nfs_verify_server_address(struct sockaddr *addr)
 761{
 762        switch (addr->sa_family) {
 763        case AF_INET: {
 764                struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 765                return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 766        }
 767        case AF_INET6: {
 768                struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 769                return !ipv6_addr_any(sa);
 770        }
 771        }
 772
 773        dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 774        return 0;
 775}
 776
 777/*
 778 * Select between a default port value and a user-specified port value.
 779 * If a zero value is set, then autobind will be used.
 780 */
 781static void nfs_set_port(struct sockaddr *sap, int *port,
 782                                 const unsigned short default_port)
 783{
 784        if (*port == NFS_UNSPEC_PORT)
 785                *port = default_port;
 786
 787        rpc_set_port(sap, *port);
 788}
 789
 790/*
 791 * Sanity check the NFS transport protocol.
 792 *
 793 */
 794static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 795{
 796        switch (mnt->nfs_server.protocol) {
 797        case XPRT_TRANSPORT_UDP:
 798        case XPRT_TRANSPORT_TCP:
 799        case XPRT_TRANSPORT_RDMA:
 800                break;
 801        default:
 802                mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 803        }
 804}
 805
 806/*
 807 * For text based NFSv2/v3 mounts, the mount protocol transport default
 808 * settings should depend upon the specified NFS transport.
 809 */
 810static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 811{
 812        nfs_validate_transport_protocol(mnt);
 813
 814        if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 815            mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 816                        return;
 817        switch (mnt->nfs_server.protocol) {
 818        case XPRT_TRANSPORT_UDP:
 819                mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 820                break;
 821        case XPRT_TRANSPORT_TCP:
 822        case XPRT_TRANSPORT_RDMA:
 823                mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 824        }
 825}
 826
 827/*
 828 * Parse the value of the 'sec=' option.
 829 */
 830static int nfs_parse_security_flavors(char *value,
 831                                      struct nfs_parsed_mount_data *mnt)
 832{
 833        substring_t args[MAX_OPT_ARGS];
 834
 835        dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 836
 837        switch (match_token(value, nfs_secflavor_tokens, args)) {
 838        case Opt_sec_none:
 839                mnt->auth_flavors[0] = RPC_AUTH_NULL;
 840                break;
 841        case Opt_sec_sys:
 842                mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 843                break;
 844        case Opt_sec_krb5:
 845                mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 846                break;
 847        case Opt_sec_krb5i:
 848                mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 849                break;
 850        case Opt_sec_krb5p:
 851                mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 852                break;
 853        case Opt_sec_lkey:
 854                mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 855                break;
 856        case Opt_sec_lkeyi:
 857                mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 858                break;
 859        case Opt_sec_lkeyp:
 860                mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 861                break;
 862        case Opt_sec_spkm:
 863                mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 864                break;
 865        case Opt_sec_spkmi:
 866                mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 867                break;
 868        case Opt_sec_spkmp:
 869                mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 870                break;
 871        default:
 872                return 0;
 873        }
 874
 875        mnt->auth_flavor_len = 1;
 876        return 1;
 877}
 878
 879/*
 880 * Error-check and convert a string of mount options from user space into
 881 * a data structure.  The whole mount string is processed; bad options are
 882 * skipped as they are encountered.  If there were no errors, return 1;
 883 * otherwise return 0 (zero).
 884 */
 885static int nfs_parse_mount_options(char *raw,
 886                                   struct nfs_parsed_mount_data *mnt)
 887{
 888        char *p, *string, *secdata;
 889        int rc, sloppy = 0, invalid_option = 0;
 890
 891        if (!raw) {
 892                dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 893                return 1;
 894        }
 895        dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 896
 897        secdata = alloc_secdata();
 898        if (!secdata)
 899                goto out_nomem;
 900
 901        rc = security_sb_copy_data(raw, secdata);
 902        if (rc)
 903                goto out_security_failure;
 904
 905        rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 906        if (rc)
 907                goto out_security_failure;
 908
 909        free_secdata(secdata);
 910
 911        while ((p = strsep(&raw, ",")) != NULL) {
 912                substring_t args[MAX_OPT_ARGS];
 913                unsigned long option;
 914                int token;
 915
 916                if (!*p)
 917                        continue;
 918
 919                dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 920
 921                token = match_token(p, nfs_mount_option_tokens, args);
 922                switch (token) {
 923
 924                /*
 925                 * boolean options:  foo/nofoo
 926                 */
 927                case Opt_soft:
 928                        mnt->flags |= NFS_MOUNT_SOFT;
 929                        break;
 930                case Opt_hard:
 931                        mnt->flags &= ~NFS_MOUNT_SOFT;
 932                        break;
 933                case Opt_posix:
 934                        mnt->flags |= NFS_MOUNT_POSIX;
 935                        break;
 936                case Opt_noposix:
 937                        mnt->flags &= ~NFS_MOUNT_POSIX;
 938                        break;
 939                case Opt_cto:
 940                        mnt->flags &= ~NFS_MOUNT_NOCTO;
 941                        break;
 942                case Opt_nocto:
 943                        mnt->flags |= NFS_MOUNT_NOCTO;
 944                        break;
 945                case Opt_ac:
 946                        mnt->flags &= ~NFS_MOUNT_NOAC;
 947                        break;
 948                case Opt_noac:
 949                        mnt->flags |= NFS_MOUNT_NOAC;
 950                        break;
 951                case Opt_lock:
 952                        mnt->flags &= ~NFS_MOUNT_NONLM;
 953                        break;
 954                case Opt_nolock:
 955                        mnt->flags |= NFS_MOUNT_NONLM;
 956                        break;
 957                case Opt_v2:
 958                        mnt->flags &= ~NFS_MOUNT_VER3;
 959                        mnt->version = 2;
 960                        break;
 961                case Opt_v3:
 962                        mnt->flags |= NFS_MOUNT_VER3;
 963                        mnt->version = 3;
 964                        break;
 965#ifdef CONFIG_NFS_V4
 966                case Opt_v4:
 967                        mnt->flags &= ~NFS_MOUNT_VER3;
 968                        mnt->version = 4;
 969                        break;
 970#endif
 971                case Opt_udp:
 972                        mnt->flags &= ~NFS_MOUNT_TCP;
 973                        mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 974                        break;
 975                case Opt_tcp:
 976                        mnt->flags |= NFS_MOUNT_TCP;
 977                        mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 978                        break;
 979                case Opt_rdma:
 980                        mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 981                        mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 982                        xprt_load_transport(p);
 983                        break;
 984                case Opt_acl:
 985                        mnt->flags &= ~NFS_MOUNT_NOACL;
 986                        break;
 987                case Opt_noacl:
 988                        mnt->flags |= NFS_MOUNT_NOACL;
 989                        break;
 990                case Opt_rdirplus:
 991                        mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 992                        break;
 993                case Opt_nordirplus:
 994                        mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 995                        break;
 996                case Opt_sharecache:
 997                        mnt->flags &= ~NFS_MOUNT_UNSHARED;
 998                        break;
 999                case Opt_nosharecache:
1000                        mnt->flags |= NFS_MOUNT_UNSHARED;
1001                        break;
1002                case Opt_resvport:
1003                        mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1004                        break;
1005                case Opt_noresvport:
1006                        mnt->flags |= NFS_MOUNT_NORESVPORT;
1007                        break;
1008                case Opt_fscache:
1009                        mnt->options |= NFS_OPTION_FSCACHE;
1010                        kfree(mnt->fscache_uniq);
1011                        mnt->fscache_uniq = NULL;
1012                        break;
1013                case Opt_nofscache:
1014                        mnt->options &= ~NFS_OPTION_FSCACHE;
1015                        kfree(mnt->fscache_uniq);
1016                        mnt->fscache_uniq = NULL;
1017                        break;
1018                case Opt_fscache_uniq:
1019                        string = match_strdup(args);
1020                        if (!string)
1021                                goto out_nomem;
1022                        kfree(mnt->fscache_uniq);
1023                        mnt->fscache_uniq = string;
1024                        mnt->options |= NFS_OPTION_FSCACHE;
1025                        break;
1026
1027                /*
1028                 * options that take numeric values
1029                 */
1030                case Opt_port:
1031                        string = match_strdup(args);
1032                        if (string == NULL)
1033                                goto out_nomem;
1034                        rc = strict_strtoul(string, 10, &option);
1035                        kfree(string);
1036                        if (rc != 0 || option > USHORT_MAX)
1037                                goto out_invalid_value;
1038                        mnt->nfs_server.port = option;
1039                        break;
1040                case Opt_rsize:
1041                        string = match_strdup(args);
1042                        if (string == NULL)
1043                                goto out_nomem;
1044                        rc = strict_strtoul(string, 10, &option);
1045                        kfree(string);
1046                        if (rc != 0)
1047                                goto out_invalid_value;
1048                        mnt->rsize = option;
1049                        break;
1050                case Opt_wsize:
1051                        string = match_strdup(args);
1052                        if (string == NULL)
1053                                goto out_nomem;
1054                        rc = strict_strtoul(string, 10, &option);
1055                        kfree(string);
1056                        if (rc != 0)
1057                                goto out_invalid_value;
1058                        mnt->wsize = option;
1059                        break;
1060                case Opt_bsize:
1061                        string = match_strdup(args);
1062                        if (string == NULL)
1063                                goto out_nomem;
1064                        rc = strict_strtoul(string, 10, &option);
1065                        kfree(string);
1066                        if (rc != 0)
1067                                goto out_invalid_value;
1068                        mnt->bsize = option;
1069                        break;
1070                case Opt_timeo:
1071                        string = match_strdup(args);
1072                        if (string == NULL)
1073                                goto out_nomem;
1074                        rc = strict_strtoul(string, 10, &option);
1075                        kfree(string);
1076                        if (rc != 0 || option == 0)
1077                                goto out_invalid_value;
1078                        mnt->timeo = option;
1079                        break;
1080                case Opt_retrans:
1081                        string = match_strdup(args);
1082                        if (string == NULL)
1083                                goto out_nomem;
1084                        rc = strict_strtoul(string, 10, &option);
1085                        kfree(string);
1086                        if (rc != 0 || option == 0)
1087                                goto out_invalid_value;
1088                        mnt->retrans = option;
1089                        break;
1090                case Opt_acregmin:
1091                        string = match_strdup(args);
1092                        if (string == NULL)
1093                                goto out_nomem;
1094                        rc = strict_strtoul(string, 10, &option);
1095                        kfree(string);
1096                        if (rc != 0)
1097                                goto out_invalid_value;
1098                        mnt->acregmin = option;
1099                        break;
1100                case Opt_acregmax:
1101                        string = match_strdup(args);
1102                        if (string == NULL)
1103                                goto out_nomem;
1104                        rc = strict_strtoul(string, 10, &option);
1105                        kfree(string);
1106                        if (rc != 0)
1107                                goto out_invalid_value;
1108                        mnt->acregmax = option;
1109                        break;
1110                case Opt_acdirmin:
1111                        string = match_strdup(args);
1112                        if (string == NULL)
1113                                goto out_nomem;
1114                        rc = strict_strtoul(string, 10, &option);
1115                        kfree(string);
1116                        if (rc != 0)
1117                                goto out_invalid_value;
1118                        mnt->acdirmin = option;
1119                        break;
1120                case Opt_acdirmax:
1121                        string = match_strdup(args);
1122                        if (string == NULL)
1123                                goto out_nomem;
1124                        rc = strict_strtoul(string, 10, &option);
1125                        kfree(string);
1126                        if (rc != 0)
1127                                goto out_invalid_value;
1128                        mnt->acdirmax = option;
1129                        break;
1130                case Opt_actimeo:
1131                        string = match_strdup(args);
1132                        if (string == NULL)
1133                                goto out_nomem;
1134                        rc = strict_strtoul(string, 10, &option);
1135                        kfree(string);
1136                        if (rc != 0)
1137                                goto out_invalid_value;
1138                        mnt->acregmin = mnt->acregmax =
1139                        mnt->acdirmin = mnt->acdirmax = option;
1140                        break;
1141                case Opt_namelen:
1142                        string = match_strdup(args);
1143                        if (string == NULL)
1144                                goto out_nomem;
1145                        rc = strict_strtoul(string, 10, &option);
1146                        kfree(string);
1147                        if (rc != 0)
1148                                goto out_invalid_value;
1149                        mnt->namlen = option;
1150                        break;
1151                case Opt_mountport:
1152                        string = match_strdup(args);
1153                        if (string == NULL)
1154                                goto out_nomem;
1155                        rc = strict_strtoul(string, 10, &option);
1156                        kfree(string);
1157                        if (rc != 0 || option > USHORT_MAX)
1158                                goto out_invalid_value;
1159                        mnt->mount_server.port = option;
1160                        break;
1161                case Opt_mountvers:
1162                        string = match_strdup(args);
1163                        if (string == NULL)
1164                                goto out_nomem;
1165                        rc = strict_strtoul(string, 10, &option);
1166                        kfree(string);
1167                        if (rc != 0 ||
1168                            option < NFS_MNT_VERSION ||
1169                            option > NFS_MNT3_VERSION)
1170                                goto out_invalid_value;
1171                        mnt->mount_server.version = option;
1172                        break;
1173                case Opt_nfsvers:
1174                        string = match_strdup(args);
1175                        if (string == NULL)
1176                                goto out_nomem;
1177                        rc = strict_strtoul(string, 10, &option);
1178                        kfree(string);
1179                        if (rc != 0)
1180                                goto out_invalid_value;
1181                        switch (option) {
1182                        case NFS2_VERSION:
1183                                mnt->flags &= ~NFS_MOUNT_VER3;
1184                                mnt->version = 2;
1185                                break;
1186                        case NFS3_VERSION:
1187                                mnt->flags |= NFS_MOUNT_VER3;
1188                                mnt->version = 3;
1189                                break;
1190#ifdef CONFIG_NFS_V4
1191                        case NFS4_VERSION:
1192                                mnt->flags &= ~NFS_MOUNT_VER3;
1193                                mnt->version = 4;
1194                                break;
1195#endif
1196                        default:
1197                                goto out_invalid_value;
1198                        }
1199                        break;
1200                case Opt_minorversion:
1201                        string = match_strdup(args);
1202                        if (string == NULL)
1203                                goto out_nomem;
1204                        rc = strict_strtoul(string, 10, &option);
1205                        kfree(string);
1206                        if (rc != 0)
1207                                goto out_invalid_value;
1208                        if (option > NFS4_MAX_MINOR_VERSION)
1209                                goto out_invalid_value;
1210                        mnt->minorversion = option;
1211                        break;
1212
1213                /*
1214                 * options that take text values
1215                 */
1216                case Opt_sec:
1217                        string = match_strdup(args);
1218                        if (string == NULL)
1219                                goto out_nomem;
1220                        rc = nfs_parse_security_flavors(string, mnt);
1221                        kfree(string);
1222                        if (!rc) {
1223                                dfprintk(MOUNT, "NFS:   unrecognized "
1224                                                "security flavor\n");
1225                                return 0;
1226                        }
1227                        break;
1228                case Opt_proto:
1229                        string = match_strdup(args);
1230                        if (string == NULL)
1231                                goto out_nomem;
1232                        token = match_token(string,
1233                                            nfs_xprt_protocol_tokens, args);
1234
1235                        switch (token) {
1236                        case Opt_xprt_udp:
1237                                mnt->flags &= ~NFS_MOUNT_TCP;
1238                                mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1239                                kfree(string);
1240                                break;
1241                        case Opt_xprt_tcp:
1242                                mnt->flags |= NFS_MOUNT_TCP;
1243                                mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1244                                kfree(string);
1245                                break;
1246                        case Opt_xprt_rdma:
1247                                /* vector side protocols to TCP */
1248                                mnt->flags |= NFS_MOUNT_TCP;
1249                                mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1250                                xprt_load_transport(string);
1251                                kfree(string);
1252                                break;
1253                        default:
1254                                dfprintk(MOUNT, "NFS:   unrecognized "
1255                                                "transport protocol\n");
1256                                kfree(string);
1257                                return 0;
1258                        }
1259                        break;
1260                case Opt_mountproto:
1261                        string = match_strdup(args);
1262                        if (string == NULL)
1263                                goto out_nomem;
1264                        token = match_token(string,
1265                                            nfs_xprt_protocol_tokens, args);
1266                        kfree(string);
1267
1268                        switch (token) {
1269                        case Opt_xprt_udp:
1270                                mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1271                                break;
1272                        case Opt_xprt_tcp:
1273                                mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1274                                break;
1275                        case Opt_xprt_rdma: /* not used for side protocols */
1276                        default:
1277                                dfprintk(MOUNT, "NFS:   unrecognized "
1278                                                "transport protocol\n");
1279                                return 0;
1280                        }
1281                        break;
1282                case Opt_addr:
1283                        string = match_strdup(args);
1284                        if (string == NULL)
1285                                goto out_nomem;
1286                        mnt->nfs_server.addrlen =
1287                                rpc_pton(string, strlen(string),
1288                                        (struct sockaddr *)
1289                                        &mnt->nfs_server.address,
1290                                        sizeof(mnt->nfs_server.address));
1291                        kfree(string);
1292                        if (mnt->nfs_server.addrlen == 0)
1293                                goto out_invalid_address;
1294                        break;
1295                case Opt_clientaddr:
1296                        string = match_strdup(args);
1297                        if (string == NULL)
1298                                goto out_nomem;
1299                        kfree(mnt->client_address);
1300                        mnt->client_address = string;
1301                        break;
1302                case Opt_mounthost:
1303                        string = match_strdup(args);
1304                        if (string == NULL)
1305                                goto out_nomem;
1306                        kfree(mnt->mount_server.hostname);
1307                        mnt->mount_server.hostname = string;
1308                        break;
1309                case Opt_mountaddr:
1310                        string = match_strdup(args);
1311                        if (string == NULL)
1312                                goto out_nomem;
1313                        mnt->mount_server.addrlen =
1314                                rpc_pton(string, strlen(string),
1315                                        (struct sockaddr *)
1316                                        &mnt->mount_server.address,
1317                                        sizeof(mnt->mount_server.address));
1318                        kfree(string);
1319                        if (mnt->mount_server.addrlen == 0)
1320                                goto out_invalid_address;
1321                        break;
1322                case Opt_lookupcache:
1323                        string = match_strdup(args);
1324                        if (string == NULL)
1325                                goto out_nomem;
1326                        token = match_token(string,
1327                                        nfs_lookupcache_tokens, args);
1328                        kfree(string);
1329                        switch (token) {
1330                                case Opt_lookupcache_all:
1331                                        mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1332                                        break;
1333                                case Opt_lookupcache_positive:
1334                                        mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1335                                        mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1336                                        break;
1337                                case Opt_lookupcache_none:
1338                                        mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1339                                        break;
1340                                default:
1341                                        dfprintk(MOUNT, "NFS:   invalid "
1342                                                        "lookupcache argument\n");
1343                                        return 0;
1344                        };
1345                        break;
1346
1347                /*
1348                 * Special options
1349                 */
1350                case Opt_sloppy:
1351                        sloppy = 1;
1352                        dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1353                        break;
1354                case Opt_userspace:
1355                case Opt_deprecated:
1356                        dfprintk(MOUNT, "NFS:   ignoring mount option "
1357                                        "'%s'\n", p);
1358                        break;
1359
1360                default:
1361                        invalid_option = 1;
1362                        dfprintk(MOUNT, "NFS:   unrecognized mount option "
1363                                        "'%s'\n", p);
1364                }
1365        }
1366
1367        if (!sloppy && invalid_option)
1368                return 0;
1369
1370        return 1;
1371
1372out_invalid_address:
1373        printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1374        return 0;
1375out_invalid_value:
1376        printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1377        return 0;
1378out_nomem:
1379        printk(KERN_INFO "NFS: not enough memory to parse option\n");
1380        return 0;
1381out_security_failure:
1382        free_secdata(secdata);
1383        printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1384        return 0;
1385}
1386
1387/*
1388 * Match the requested auth flavors with the list returned by
1389 * the server.  Returns zero and sets the mount's authentication
1390 * flavor on success; returns -EACCES if server does not support
1391 * the requested flavor.
1392 */
1393static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1394                             struct nfs_mount_request *request)
1395{
1396        unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1397
1398        /*
1399         * Certain releases of Linux's mountd return an empty
1400         * flavor list.  To prevent behavioral regression with
1401         * these servers (ie. rejecting mounts that used to
1402         * succeed), revert to pre-2.6.32 behavior (no checking)
1403         * if the returned flavor list is empty.
1404         */
1405        if (server_authlist_len == 0)
1406                return 0;
1407
1408        /*
1409         * We avoid sophisticated negotiating here, as there are
1410         * plenty of cases where we can get it wrong, providing
1411         * either too little or too much security.
1412         *
1413         * RFC 2623, section 2.7 suggests we SHOULD prefer the
1414         * flavor listed first.  However, some servers list
1415         * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1416         * preferred default, in args->auth_flavors[0] if user
1417         * didn't specify sec= mount option.
1418         */
1419        for (i = 0; i < args->auth_flavor_len; i++)
1420                for (j = 0; j < server_authlist_len; j++)
1421                        if (args->auth_flavors[i] == request->auth_flavs[j]) {
1422                                dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1423                                        request->auth_flavs[j]);
1424                                args->auth_flavors[0] = request->auth_flavs[j];
1425                                return 0;
1426                        }
1427
1428        dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1429        nfs_umount(request);
1430        return -EACCES;
1431}
1432
1433/*
1434 * Use the remote server's MOUNT service to request the NFS file handle
1435 * corresponding to the provided path.
1436 */
1437static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1438                         struct nfs_fh *root_fh)
1439{
1440        rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1441        unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1442        struct nfs_mount_request request = {
1443                .sap            = (struct sockaddr *)
1444                                                &args->mount_server.address,
1445                .dirpath        = args->nfs_server.export_path,
1446                .protocol       = args->mount_server.protocol,
1447                .fh             = root_fh,
1448                .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1449                .auth_flav_len  = &server_authlist_len,
1450                .auth_flavs     = server_authlist,
1451        };
1452        int status;
1453
1454        if (args->mount_server.version == 0) {
1455                switch (args->version) {
1456                        default:
1457                                args->mount_server.version = NFS_MNT3_VERSION;
1458                                break;
1459                        case 2:
1460                                args->mount_server.version = NFS_MNT_VERSION;
1461                }
1462        }
1463        request.version = args->mount_server.version;
1464
1465        if (args->mount_server.hostname)
1466                request.hostname = args->mount_server.hostname;
1467        else
1468                request.hostname = args->nfs_server.hostname;
1469
1470        /*
1471         * Construct the mount server's address.
1472         */
1473        if (args->mount_server.address.ss_family == AF_UNSPEC) {
1474                memcpy(request.sap, &args->nfs_server.address,
1475                       args->nfs_server.addrlen);
1476                args->mount_server.addrlen = args->nfs_server.addrlen;
1477        }
1478        request.salen = args->mount_server.addrlen;
1479        nfs_set_port(request.sap, &args->mount_server.port, 0);
1480
1481        /*
1482         * Now ask the mount server to map our export path
1483         * to a file handle.
1484         */
1485        status = nfs_mount(&request);
1486        if (status != 0) {
1487                dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1488                                request.hostname, status);
1489                return status;
1490        }
1491
1492        /*
1493         * MNTv1 (NFSv2) does not support auth flavor negotiation.
1494         */
1495        if (args->mount_server.version != NFS_MNT3_VERSION)
1496                return 0;
1497        return nfs_walk_authlist(args, &request);
1498}
1499
1500static int nfs_parse_simple_hostname(const char *dev_name,
1501                                     char **hostname, size_t maxnamlen,
1502                                     char **export_path, size_t maxpathlen)
1503{
1504        size_t len;
1505        char *colon, *comma;
1506
1507        colon = strchr(dev_name, ':');
1508        if (colon == NULL)
1509                goto out_bad_devname;
1510
1511        len = colon - dev_name;
1512        if (len > maxnamlen)
1513                goto out_hostname;
1514
1515        /* N.B. caller will free nfs_server.hostname in all cases */
1516        *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1517        if (!*hostname)
1518                goto out_nomem;
1519
1520        /* kill possible hostname list: not supported */
1521        comma = strchr(*hostname, ',');
1522        if (comma != NULL) {
1523                if (comma == *hostname)
1524                        goto out_bad_devname;
1525                *comma = '\0';
1526        }
1527
1528        colon++;
1529        len = strlen(colon);
1530        if (len > maxpathlen)
1531                goto out_path;
1532        *export_path = kstrndup(colon, len, GFP_KERNEL);
1533        if (!*export_path)
1534                goto out_nomem;
1535
1536        dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1537        return 0;
1538
1539out_bad_devname:
1540        dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1541        return -EINVAL;
1542
1543out_nomem:
1544        dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1545        return -ENOMEM;
1546
1547out_hostname:
1548        dfprintk(MOUNT, "NFS: server hostname too long\n");
1549        return -ENAMETOOLONG;
1550
1551out_path:
1552        dfprintk(MOUNT, "NFS: export pathname too long\n");
1553        return -ENAMETOOLONG;
1554}
1555
1556/*
1557 * Hostname has square brackets around it because it contains one or
1558 * more colons.  We look for the first closing square bracket, and a
1559 * colon must follow it.
1560 */
1561static int nfs_parse_protected_hostname(const char *dev_name,
1562                                        char **hostname, size_t maxnamlen,
1563                                        char **export_path, size_t maxpathlen)
1564{
1565        size_t len;
1566        char *start, *end;
1567
1568        start = (char *)(dev_name + 1);
1569
1570        end = strchr(start, ']');
1571        if (end == NULL)
1572                goto out_bad_devname;
1573        if (*(end + 1) != ':')
1574                goto out_bad_devname;
1575
1576        len = end - start;
1577        if (len > maxnamlen)
1578                goto out_hostname;
1579
1580        /* N.B. caller will free nfs_server.hostname in all cases */
1581        *hostname = kstrndup(start, len, GFP_KERNEL);
1582        if (*hostname == NULL)
1583                goto out_nomem;
1584
1585        end += 2;
1586        len = strlen(end);
1587        if (len > maxpathlen)
1588                goto out_path;
1589        *export_path = kstrndup(end, len, GFP_KERNEL);
1590        if (!*export_path)
1591                goto out_nomem;
1592
1593        return 0;
1594
1595out_bad_devname:
1596        dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1597        return -EINVAL;
1598
1599out_nomem:
1600        dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1601        return -ENOMEM;
1602
1603out_hostname:
1604        dfprintk(MOUNT, "NFS: server hostname too long\n");
1605        return -ENAMETOOLONG;
1606
1607out_path:
1608        dfprintk(MOUNT, "NFS: export pathname too long\n");
1609        return -ENAMETOOLONG;
1610}
1611
1612/*
1613 * Split "dev_name" into "hostname:export_path".
1614 *
1615 * The leftmost colon demarks the split between the server's hostname
1616 * and the export path.  If the hostname starts with a left square
1617 * bracket, then it may contain colons.
1618 *
1619 * Note: caller frees hostname and export path, even on error.
1620 */
1621static int nfs_parse_devname(const char *dev_name,
1622                             char **hostname, size_t maxnamlen,
1623                             char **export_path, size_t maxpathlen)
1624{
1625        if (*dev_name == '[')
1626                return nfs_parse_protected_hostname(dev_name,
1627                                                    hostname, maxnamlen,
1628                                                    export_path, maxpathlen);
1629
1630        return nfs_parse_simple_hostname(dev_name,
1631                                         hostname, maxnamlen,
1632                                         export_path, maxpathlen);
1633}
1634
1635/*
1636 * Validate the NFS2/NFS3 mount data
1637 * - fills in the mount root filehandle
1638 *
1639 * For option strings, user space handles the following behaviors:
1640 *
1641 * + DNS: mapping server host name to IP address ("addr=" option)
1642 *
1643 * + failure mode: how to behave if a mount request can't be handled
1644 *   immediately ("fg/bg" option)
1645 *
1646 * + retry: how often to retry a mount request ("retry=" option)
1647 *
1648 * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1649 *   mountproto=tcp after mountproto=udp, and so on
1650 */
1651static int nfs_validate_mount_data(void *options,
1652                                   struct nfs_parsed_mount_data *args,
1653                                   struct nfs_fh *mntfh,
1654                                   const char *dev_name)
1655{
1656        struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1657        struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1658
1659        if (data == NULL)
1660                goto out_no_data;
1661
1662        switch (data->version) {
1663        case 1:
1664                data->namlen = 0;
1665        case 2:
1666                data->bsize = 0;
1667        case 3:
1668                if (data->flags & NFS_MOUNT_VER3)
1669                        goto out_no_v3;
1670                data->root.size = NFS2_FHSIZE;
1671                memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1672        case 4:
1673                if (data->flags & NFS_MOUNT_SECFLAVOUR)
1674                        goto out_no_sec;
1675        case 5:
1676                memset(data->context, 0, sizeof(data->context));
1677        case 6:
1678                if (data->flags & NFS_MOUNT_VER3) {
1679                        if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1680                                goto out_invalid_fh;
1681                        mntfh->size = data->root.size;
1682                        args->version = 3;
1683                } else {
1684                        mntfh->size = NFS2_FHSIZE;
1685                        args->version = 2;
1686                }
1687
1688
1689                memcpy(mntfh->data, data->root.data, mntfh->size);
1690                if (mntfh->size < sizeof(mntfh->data))
1691                        memset(mntfh->data + mntfh->size, 0,
1692                               sizeof(mntfh->data) - mntfh->size);
1693
1694                /*
1695                 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1696                 * can deal with.
1697                 */
1698                args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1699                args->rsize             = data->rsize;
1700                args->wsize             = data->wsize;
1701                args->timeo             = data->timeo;
1702                args->retrans           = data->retrans;
1703                args->acregmin          = data->acregmin;
1704                args->acregmax          = data->acregmax;
1705                args->acdirmin          = data->acdirmin;
1706                args->acdirmax          = data->acdirmax;
1707
1708                memcpy(sap, &data->addr, sizeof(data->addr));
1709                args->nfs_server.addrlen = sizeof(data->addr);
1710                if (!nfs_verify_server_address(sap))
1711                        goto out_no_address;
1712
1713                if (!(data->flags & NFS_MOUNT_TCP))
1714                        args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1715                /* N.B. caller will free nfs_server.hostname in all cases */
1716                args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1717                args->namlen            = data->namlen;
1718                args->bsize             = data->bsize;
1719
1720                if (data->flags & NFS_MOUNT_SECFLAVOUR)
1721                        args->auth_flavors[0] = data->pseudoflavor;
1722                if (!args->nfs_server.hostname)
1723                        goto out_nomem;
1724
1725                /*
1726                 * The legacy version 6 binary mount data from userspace has a
1727                 * field used only to transport selinux information into the
1728                 * the kernel.  To continue to support that functionality we
1729                 * have a touch of selinux knowledge here in the NFS code. The
1730                 * userspace code converted context=blah to just blah so we are
1731                 * converting back to the full string selinux understands.
1732                 */
1733                if (data->context[0]){
1734#ifdef CONFIG_SECURITY_SELINUX
1735                        int rc;
1736                        char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1737                        if (!opts_str)
1738                                return -ENOMEM;
1739                        strcpy(opts_str, "context=");
1740                        data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1741                        strcat(opts_str, &data->context[0]);
1742                        rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1743                        kfree(opts_str);
1744                        if (rc)
1745                                return rc;
1746#else
1747                        return -EINVAL;
1748#endif
1749                }
1750
1751                break;
1752        default: {
1753                int status;
1754
1755                if (nfs_parse_mount_options((char *)options, args) == 0)
1756                        return -EINVAL;
1757
1758                if (!nfs_verify_server_address(sap))
1759                        goto out_no_address;
1760
1761                if (args->version == 4)
1762#ifdef CONFIG_NFS_V4
1763                        return nfs4_validate_text_mount_data(options,
1764                                                             args, dev_name);
1765#else
1766                        goto out_v4_not_compiled;
1767#endif
1768
1769                nfs_set_port(sap, &args->nfs_server.port, 0);
1770
1771                nfs_set_mount_transport_protocol(args);
1772
1773                status = nfs_parse_devname(dev_name,
1774                                           &args->nfs_server.hostname,
1775                                           PAGE_SIZE,
1776                                           &args->nfs_server.export_path,
1777                                           NFS_MAXPATHLEN);
1778                if (!status)
1779                        status = nfs_try_mount(args, mntfh);
1780
1781                kfree(args->nfs_server.export_path);
1782                args->nfs_server.export_path = NULL;
1783
1784                if (status)
1785                        return status;
1786
1787                break;
1788                }
1789        }
1790
1791#ifndef CONFIG_NFS_V3
1792        if (args->version == 3)
1793                goto out_v3_not_compiled;
1794#endif /* !CONFIG_NFS_V3 */
1795
1796        return 0;
1797
1798out_no_data:
1799        dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1800        return -EINVAL;
1801
1802out_no_v3:
1803        dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1804                 data->version);
1805        return -EINVAL;
1806
1807out_no_sec:
1808        dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1809        return -EINVAL;
1810
1811#ifndef CONFIG_NFS_V3
1812out_v3_not_compiled:
1813        dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1814        return -EPROTONOSUPPORT;
1815#endif /* !CONFIG_NFS_V3 */
1816
1817#ifndef CONFIG_NFS_V4
1818out_v4_not_compiled:
1819        dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1820        return -EPROTONOSUPPORT;
1821#endif /* !CONFIG_NFS_V4 */
1822
1823out_nomem:
1824        dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1825        return -ENOMEM;
1826
1827out_no_address:
1828        dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1829        return -EINVAL;
1830
1831out_invalid_fh:
1832        dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1833        return -EINVAL;
1834}
1835
1836static int
1837nfs_compare_remount_data(struct nfs_server *nfss,
1838                         struct nfs_parsed_mount_data *data)
1839{
1840        if (data->flags != nfss->flags ||
1841            data->rsize != nfss->rsize ||
1842            data->wsize != nfss->wsize ||
1843            data->retrans != nfss->client->cl_timeout->to_retries ||
1844            data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1845            data->acregmin != nfss->acregmin / HZ ||
1846            data->acregmax != nfss->acregmax / HZ ||
1847            data->acdirmin != nfss->acdirmin / HZ ||
1848            data->acdirmax != nfss->acdirmax / HZ ||
1849            data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1850            data->nfs_server.port != nfss->port ||
1851            data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1852            !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1853                          (struct sockaddr *)&nfss->nfs_client->cl_addr))
1854                return -EINVAL;
1855
1856        return 0;
1857}
1858
1859static int
1860nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1861{
1862        int error;
1863        struct nfs_server *nfss = sb->s_fs_info;
1864        struct nfs_parsed_mount_data *data;
1865        struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1866        struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1867        u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1868
1869        /*
1870         * Userspace mount programs that send binary options generally send
1871         * them populated with default values. We have no way to know which
1872         * ones were explicitly specified. Fall back to legacy behavior and
1873         * just return success.
1874         */
1875        if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1876            (nfsvers <= 3 && (!options || (options->version >= 1 &&
1877                                           options->version <= 6))))
1878                return 0;
1879
1880        data = kzalloc(sizeof(*data), GFP_KERNEL);
1881        if (data == NULL)
1882                return -ENOMEM;
1883
1884        lock_kernel();
1885        /* fill out struct with values from existing mount */
1886        data->flags = nfss->flags;
1887        data->rsize = nfss->rsize;
1888        data->wsize = nfss->wsize;
1889        data->retrans = nfss->client->cl_timeout->to_retries;
1890        data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1891        data->acregmin = nfss->acregmin / HZ;
1892        data->acregmax = nfss->acregmax / HZ;
1893        data->acdirmin = nfss->acdirmin / HZ;
1894        data->acdirmax = nfss->acdirmax / HZ;
1895        data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1896        data->nfs_server.port = nfss->port;
1897        data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1898        memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1899                data->nfs_server.addrlen);
1900
1901        /* overwrite those values with any that were specified */
1902        error = nfs_parse_mount_options((char *)options, data);
1903        if (error < 0)
1904                goto out;
1905
1906        /* compare new mount options with old ones */
1907        error = nfs_compare_remount_data(nfss, data);
1908out:
1909        kfree(data);
1910        unlock_kernel();
1911        return error;
1912}
1913
1914/*
1915 * Initialise the common bits of the superblock
1916 */
1917static inline void nfs_initialise_sb(struct super_block *sb)
1918{
1919        struct nfs_server *server = NFS_SB(sb);
1920
1921        sb->s_magic = NFS_SUPER_MAGIC;
1922
1923        /* We probably want something more informative here */
1924        snprintf(sb->s_id, sizeof(sb->s_id),
1925                 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1926
1927        if (sb->s_blocksize == 0)
1928                sb->s_blocksize = nfs_block_bits(server->wsize,
1929                                                 &sb->s_blocksize_bits);
1930
1931        if (server->flags & NFS_MOUNT_NOAC)
1932                sb->s_flags |= MS_SYNCHRONOUS;
1933
1934        sb->s_bdi = &server->backing_dev_info;
1935
1936        nfs_super_set_maxbytes(sb, server->maxfilesize);
1937}
1938
1939/*
1940 * Finish setting up an NFS2/3 superblock
1941 */
1942static void nfs_fill_super(struct super_block *sb,
1943                           struct nfs_parsed_mount_data *data)
1944{
1945        struct nfs_server *server = NFS_SB(sb);
1946
1947        sb->s_blocksize_bits = 0;
1948        sb->s_blocksize = 0;
1949        if (data->bsize)
1950                sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1951
1952        if (server->nfs_client->rpc_ops->version == 3) {
1953                /* The VFS shouldn't apply the umask to mode bits. We will do
1954                 * so ourselves when necessary.
1955                 */
1956                sb->s_flags |= MS_POSIXACL;
1957                sb->s_time_gran = 1;
1958        }
1959
1960        sb->s_op = &nfs_sops;
1961        nfs_initialise_sb(sb);
1962}
1963
1964/*
1965 * Finish setting up a cloned NFS2/3 superblock
1966 */
1967static void nfs_clone_super(struct super_block *sb,
1968                            const struct super_block *old_sb)
1969{
1970        struct nfs_server *server = NFS_SB(sb);
1971
1972        sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1973        sb->s_blocksize = old_sb->s_blocksize;
1974        sb->s_maxbytes = old_sb->s_maxbytes;
1975
1976        if (server->nfs_client->rpc_ops->version == 3) {
1977                /* The VFS shouldn't apply the umask to mode bits. We will do
1978                 * so ourselves when necessary.
1979                 */
1980                sb->s_flags |= MS_POSIXACL;
1981                sb->s_time_gran = 1;
1982        }
1983
1984        sb->s_op = old_sb->s_op;
1985        nfs_initialise_sb(sb);
1986}
1987
1988static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1989{
1990        const struct nfs_server *a = s->s_fs_info;
1991        const struct rpc_clnt *clnt_a = a->client;
1992        const struct rpc_clnt *clnt_b = b->client;
1993
1994        if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1995                goto Ebusy;
1996        if (a->nfs_client != b->nfs_client)
1997                goto Ebusy;
1998        if (a->flags != b->flags)
1999                goto Ebusy;
2000        if (a->wsize != b->wsize)
2001                goto Ebusy;
2002        if (a->rsize != b->rsize)
2003                goto Ebusy;
2004        if (a->acregmin != b->acregmin)
2005                goto Ebusy;
2006        if (a->acregmax != b->acregmax)
2007                goto Ebusy;
2008        if (a->acdirmin != b->acdirmin)
2009                goto Ebusy;
2010        if (a->acdirmax != b->acdirmax)
2011                goto Ebusy;
2012        if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2013                goto Ebusy;
2014        return 1;
2015Ebusy:
2016        return 0;
2017}
2018
2019struct nfs_sb_mountdata {
2020        struct nfs_server *server;
2021        int mntflags;
2022};
2023
2024static int nfs_set_super(struct super_block *s, void *data)
2025{
2026        struct nfs_sb_mountdata *sb_mntdata = data;
2027        struct nfs_server *server = sb_mntdata->server;
2028        int ret;
2029
2030        s->s_flags = sb_mntdata->mntflags;
2031        s->s_fs_info = server;
2032        ret = set_anon_super(s, server);
2033        if (ret == 0)
2034                server->s_dev = s->s_dev;
2035        return ret;
2036}
2037
2038static int nfs_compare_super_address(struct nfs_server *server1,
2039                                     struct nfs_server *server2)
2040{
2041        struct sockaddr *sap1, *sap2;
2042
2043        sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2044        sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2045
2046        if (sap1->sa_family != sap2->sa_family)
2047                return 0;
2048
2049        switch (sap1->sa_family) {
2050        case AF_INET: {
2051                struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2052                struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2053                if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2054                        return 0;
2055                if (sin1->sin_port != sin2->sin_port)
2056                        return 0;
2057                break;
2058        }
2059        case AF_INET6: {
2060                struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2061                struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2062                if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2063                        return 0;
2064                if (sin1->sin6_port != sin2->sin6_port)
2065                        return 0;
2066                break;
2067        }
2068        default:
2069                return 0;
2070        }
2071
2072        return 1;
2073}
2074
2075static int nfs_compare_super(struct super_block *sb, void *data)
2076{
2077        struct nfs_sb_mountdata *sb_mntdata = data;
2078        struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2079        int mntflags = sb_mntdata->mntflags;
2080
2081        if (!nfs_compare_super_address(old, server))
2082                return 0;
2083        /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2084        if (old->flags & NFS_MOUNT_UNSHARED)
2085                return 0;
2086        if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2087                return 0;
2088        return nfs_compare_mount_options(sb, server, mntflags);
2089}
2090
2091static int nfs_bdi_register(struct nfs_server *server)
2092{
2093        return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2094}
2095
2096static int nfs_get_sb(struct file_system_type *fs_type,
2097        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2098{
2099        struct nfs_server *server = NULL;
2100        struct super_block *s;
2101        struct nfs_parsed_mount_data *data;
2102        struct nfs_fh *mntfh;
2103        struct dentry *mntroot;
2104        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2105        struct nfs_sb_mountdata sb_mntdata = {
2106                .mntflags = flags,
2107        };
2108        int error = -ENOMEM;
2109
2110        data = nfs_alloc_parsed_mount_data(3);
2111        mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2112        if (data == NULL || mntfh == NULL)
2113                goto out_free_fh;
2114
2115        security_init_mnt_opts(&data->lsm_opts);
2116
2117        /* Validate the mount data */
2118        error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2119        if (error < 0)
2120                goto out;
2121
2122#ifdef CONFIG_NFS_V4
2123        if (data->version == 4) {
2124                error = nfs4_try_mount(flags, dev_name, data, mnt);
2125                kfree(data->client_address);
2126                goto out;
2127        }
2128#endif  /* CONFIG_NFS_V4 */
2129
2130        /* Get a volume representation */
2131        server = nfs_create_server(data, mntfh);
2132        if (IS_ERR(server)) {
2133                error = PTR_ERR(server);
2134                goto out;
2135        }
2136        sb_mntdata.server = server;
2137
2138        if (server->flags & NFS_MOUNT_UNSHARED)
2139                compare_super = NULL;
2140
2141        /* Get a superblock - note that we may end up sharing one that already exists */
2142        s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2143        if (IS_ERR(s)) {
2144                error = PTR_ERR(s);
2145                goto out_err_nosb;
2146        }
2147
2148        if (s->s_fs_info != server) {
2149                nfs_free_server(server);
2150                server = NULL;
2151        } else {
2152                error = nfs_bdi_register(server);
2153                if (error)
2154                        goto error_splat_super;
2155        }
2156
2157        if (!s->s_root) {
2158                /* initial superblock/root creation */
2159                nfs_fill_super(s, data);
2160                nfs_fscache_get_super_cookie(
2161                        s, data ? data->fscache_uniq : NULL, NULL);
2162        }
2163
2164        mntroot = nfs_get_root(s, mntfh);
2165        if (IS_ERR(mntroot)) {
2166                error = PTR_ERR(mntroot);
2167                goto error_splat_super;
2168        }
2169
2170        error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2171        if (error)
2172                goto error_splat_root;
2173
2174        s->s_flags |= MS_ACTIVE;
2175        mnt->mnt_sb = s;
2176        mnt->mnt_root = mntroot;
2177        error = 0;
2178
2179out:
2180        kfree(data->nfs_server.hostname);
2181        kfree(data->mount_server.hostname);
2182        kfree(data->fscache_uniq);
2183        security_free_mnt_opts(&data->lsm_opts);
2184out_free_fh:
2185        kfree(mntfh);
2186        kfree(data);
2187        return error;
2188
2189out_err_nosb:
2190        nfs_free_server(server);
2191        goto out;
2192
2193error_splat_root:
2194        dput(mntroot);
2195error_splat_super:
2196        deactivate_locked_super(s);
2197        goto out;
2198}
2199
2200/*
2201 * Destroy an NFS2/3 superblock
2202 */
2203static void nfs_kill_super(struct super_block *s)
2204{
2205        struct nfs_server *server = NFS_SB(s);
2206
2207        kill_anon_super(s);
2208        bdi_unregister(&server->backing_dev_info);
2209        nfs_fscache_release_super_cookie(s);
2210        nfs_free_server(server);
2211}
2212
2213/*
2214 * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2215 */
2216static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2217                           const char *dev_name, void *raw_data,
2218                           struct vfsmount *mnt)
2219{
2220        struct nfs_clone_mount *data = raw_data;
2221        struct super_block *s;
2222        struct nfs_server *server;
2223        struct dentry *mntroot;
2224        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2225        struct nfs_sb_mountdata sb_mntdata = {
2226                .mntflags = flags,
2227        };
2228        int error;
2229
2230        dprintk("--> nfs_xdev_get_sb()\n");
2231
2232        /* create a new volume representation */
2233        server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2234        if (IS_ERR(server)) {
2235                error = PTR_ERR(server);
2236                goto out_err_noserver;
2237        }
2238        sb_mntdata.server = server;
2239
2240        if (server->flags & NFS_MOUNT_UNSHARED)
2241                compare_super = NULL;
2242
2243        /* Get a superblock - note that we may end up sharing one that already exists */
2244        s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2245        if (IS_ERR(s)) {
2246                error = PTR_ERR(s);
2247                goto out_err_nosb;
2248        }
2249
2250        if (s->s_fs_info != server) {
2251                nfs_free_server(server);
2252                server = NULL;
2253        } else {
2254                error = nfs_bdi_register(server);
2255                if (error)
2256                        goto error_splat_super;
2257        }
2258
2259        if (!s->s_root) {
2260                /* initial superblock/root creation */
2261                nfs_clone_super(s, data->sb);
2262                nfs_fscache_get_super_cookie(s, NULL, data);
2263        }
2264
2265        mntroot = nfs_get_root(s, data->fh);
2266        if (IS_ERR(mntroot)) {
2267                error = PTR_ERR(mntroot);
2268                goto error_splat_super;
2269        }
2270        if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2271                dput(mntroot);
2272                error = -ESTALE;
2273                goto error_splat_super;
2274        }
2275
2276        s->s_flags |= MS_ACTIVE;
2277        mnt->mnt_sb = s;
2278        mnt->mnt_root = mntroot;
2279
2280        /* clone any lsm security options from the parent to the new sb */
2281        security_sb_clone_mnt_opts(data->sb, s);
2282
2283        dprintk("<-- nfs_xdev_get_sb() = 0\n");
2284        return 0;
2285
2286out_err_nosb:
2287        nfs_free_server(server);
2288out_err_noserver:
2289        dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2290        return error;
2291
2292error_splat_super:
2293        deactivate_locked_super(s);
2294        dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2295        return error;
2296}
2297
2298#ifdef CONFIG_NFS_V4
2299
2300/*
2301 * Finish setting up a cloned NFS4 superblock
2302 */
2303static void nfs4_clone_super(struct super_block *sb,
2304                            const struct super_block *old_sb)
2305{
2306        sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2307        sb->s_blocksize = old_sb->s_blocksize;
2308        sb->s_maxbytes = old_sb->s_maxbytes;
2309        sb->s_time_gran = 1;
2310        sb->s_op = old_sb->s_op;
2311        nfs_initialise_sb(sb);
2312}
2313
2314/*
2315 * Set up an NFS4 superblock
2316 */
2317static void nfs4_fill_super(struct super_block *sb)
2318{
2319        sb->s_time_gran = 1;
2320        sb->s_op = &nfs4_sops;
2321        nfs_initialise_sb(sb);
2322}
2323
2324static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2325{
2326        args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2327}
2328
2329static int nfs4_validate_text_mount_data(void *options,
2330                                         struct nfs_parsed_mount_data *args,
2331                                         const char *dev_name)
2332{
2333        struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2334
2335        nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2336
2337        nfs_validate_transport_protocol(args);
2338
2339        nfs4_validate_mount_flags(args);
2340
2341        if (args->version != 4) {
2342                dfprintk(MOUNT,
2343                         "NFS4: Illegal mount version\n");
2344                return -EINVAL;
2345        }
2346
2347        if (args->auth_flavor_len > 1) {
2348                dfprintk(MOUNT,
2349                         "NFS4: Too many RPC auth flavours specified\n");
2350                return -EINVAL;
2351        }
2352
2353        if (args->client_address == NULL) {
2354                dfprintk(MOUNT,
2355                         "NFS4: mount program didn't pass callback address\n");
2356                return -EINVAL;
2357        }
2358
2359        return nfs_parse_devname(dev_name,
2360                                   &args->nfs_server.hostname,
2361                                   NFS4_MAXNAMLEN,
2362                                   &args->nfs_server.export_path,
2363                                   NFS4_MAXPATHLEN);
2364}
2365
2366/*
2367 * Validate NFSv4 mount options
2368 */
2369static int nfs4_validate_mount_data(void *options,
2370                                    struct nfs_parsed_mount_data *args,
2371                                    const char *dev_name)
2372{
2373        struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2374        struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2375        char *c;
2376
2377        if (data == NULL)
2378                goto out_no_data;
2379
2380        switch (data->version) {
2381        case 1:
2382                if (data->host_addrlen > sizeof(args->nfs_server.address))
2383                        goto out_no_address;
2384                if (data->host_addrlen == 0)
2385                        goto out_no_address;
2386                args->nfs_server.addrlen = data->host_addrlen;
2387                if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2388                        return -EFAULT;
2389                if (!nfs_verify_server_address(sap))
2390                        goto out_no_address;
2391
2392                if (data->auth_flavourlen) {
2393                        if (data->auth_flavourlen > 1)
2394                                goto out_inval_auth;
2395                        if (copy_from_user(&args->auth_flavors[0],
2396                                           data->auth_flavours,
2397                                           sizeof(args->auth_flavors[0])))
2398                                return -EFAULT;
2399                }
2400
2401                c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2402                if (IS_ERR(c))
2403                        return PTR_ERR(c);
2404                args->nfs_server.hostname = c;
2405
2406                c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2407                if (IS_ERR(c))
2408                        return PTR_ERR(c);
2409                args->nfs_server.export_path = c;
2410                dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2411
2412                c = strndup_user(data->client_addr.data, 16);
2413                if (IS_ERR(c))
2414                        return PTR_ERR(c);
2415                args->client_address = c;
2416
2417                /*
2418                 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2419                 * can deal with.
2420                 */
2421
2422                args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2423                args->rsize     = data->rsize;
2424                args->wsize     = data->wsize;
2425                args->timeo     = data->timeo;
2426                args->retrans   = data->retrans;
2427                args->acregmin  = data->acregmin;
2428                args->acregmax  = data->acregmax;
2429                args->acdirmin  = data->acdirmin;
2430                args->acdirmax  = data->acdirmax;
2431                args->nfs_server.protocol = data->proto;
2432                nfs_validate_transport_protocol(args);
2433
2434                break;
2435        default:
2436                if (nfs_parse_mount_options((char *)options, args) == 0)
2437                        return -EINVAL;
2438
2439                if (!nfs_verify_server_address(sap))
2440                        return -EINVAL;
2441
2442                return nfs4_validate_text_mount_data(options, args, dev_name);
2443        }
2444
2445        return 0;
2446
2447out_no_data:
2448        dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2449        return -EINVAL;
2450
2451out_inval_auth:
2452        dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2453                 data->auth_flavourlen);
2454        return -EINVAL;
2455
2456out_no_address:
2457        dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2458        return -EINVAL;
2459}
2460
2461/*
2462 * Get the superblock for the NFS4 root partition
2463 */
2464static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2465        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2466{
2467        struct nfs_parsed_mount_data *data = raw_data;
2468        struct super_block *s;
2469        struct nfs_server *server;
2470        struct nfs_fh *mntfh;
2471        struct dentry *mntroot;
2472        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2473        struct nfs_sb_mountdata sb_mntdata = {
2474                .mntflags = flags,
2475        };
2476        int error = -ENOMEM;
2477
2478        mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2479        if (data == NULL || mntfh == NULL)
2480                goto out_free_fh;
2481
2482        security_init_mnt_opts(&data->lsm_opts);
2483
2484        /* Get a volume representation */
2485        server = nfs4_create_server(data, mntfh);
2486        if (IS_ERR(server)) {
2487                error = PTR_ERR(server);
2488                goto out;
2489        }
2490        sb_mntdata.server = server;
2491
2492        if (server->flags & NFS4_MOUNT_UNSHARED)
2493                compare_super = NULL;
2494
2495        /* Get a superblock - note that we may end up sharing one that already exists */
2496        s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2497        if (IS_ERR(s)) {
2498                error = PTR_ERR(s);
2499                goto out_free;
2500        }
2501
2502        if (s->s_fs_info != server) {
2503                nfs_free_server(server);
2504                server = NULL;
2505        } else {
2506                error = nfs_bdi_register(server);
2507                if (error)
2508                        goto error_splat_super;
2509        }
2510
2511        if (!s->s_root) {
2512                /* initial superblock/root creation */
2513                nfs4_fill_super(s);
2514                nfs_fscache_get_super_cookie(
2515                        s, data ? data->fscache_uniq : NULL, NULL);
2516        }
2517
2518        mntroot = nfs4_get_root(s, mntfh);
2519        if (IS_ERR(mntroot)) {
2520                error = PTR_ERR(mntroot);
2521                goto error_splat_super;
2522        }
2523
2524        error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2525        if (error)
2526                goto error_splat_root;
2527
2528        s->s_flags |= MS_ACTIVE;
2529        mnt->mnt_sb = s;
2530        mnt->mnt_root = mntroot;
2531        error = 0;
2532
2533out:
2534        security_free_mnt_opts(&data->lsm_opts);
2535out_free_fh:
2536        kfree(mntfh);
2537        return error;
2538
2539out_free:
2540        nfs_free_server(server);
2541        goto out;
2542
2543error_splat_root:
2544        dput(mntroot);
2545error_splat_super:
2546        deactivate_locked_super(s);
2547        goto out;
2548}
2549
2550static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2551                int flags, void *data, const char *hostname)
2552{
2553        struct vfsmount *root_mnt;
2554        char *root_devname;
2555        size_t len;
2556
2557        len = strlen(hostname) + 3;
2558        root_devname = kmalloc(len, GFP_KERNEL);
2559        if (root_devname == NULL)
2560                return ERR_PTR(-ENOMEM);
2561        snprintf(root_devname, len, "%s:/", hostname);
2562        root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2563        kfree(root_devname);
2564        return root_mnt;
2565}
2566
2567static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2568{
2569        char *page = (char *) __get_free_page(GFP_KERNEL);
2570        char *devname, *tmp;
2571
2572        if (page == NULL)
2573                return;
2574        devname = nfs_path(path->mnt->mnt_devname,
2575                        path->mnt->mnt_root, path->dentry,
2576                        page, PAGE_SIZE);
2577        if (devname == NULL)
2578                goto out_freepage;
2579        tmp = kstrdup(devname, GFP_KERNEL);
2580        if (tmp == NULL)
2581                goto out_freepage;
2582        kfree(mnt->mnt_devname);
2583        mnt->mnt_devname = tmp;
2584out_freepage:
2585        free_page((unsigned long)page);
2586}
2587
2588static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2589                const char *export_path, struct vfsmount *mnt_target)
2590{
2591        struct mnt_namespace *ns_private;
2592        struct nameidata nd;
2593        struct super_block *s;
2594        int ret;
2595
2596        ns_private = create_mnt_ns(root_mnt);
2597        ret = PTR_ERR(ns_private);
2598        if (IS_ERR(ns_private))
2599                goto out_mntput;
2600
2601        ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2602                        export_path, LOOKUP_FOLLOW, &nd);
2603
2604        put_mnt_ns(ns_private);
2605
2606        if (ret != 0)
2607                goto out_err;
2608
2609        s = nd.path.mnt->mnt_sb;
2610        atomic_inc(&s->s_active);
2611        mnt_target->mnt_sb = s;
2612        mnt_target->mnt_root = dget(nd.path.dentry);
2613
2614        /* Correct the device pathname */
2615        nfs_fix_devname(&nd.path, mnt_target);
2616
2617        path_put(&nd.path);
2618        down_write(&s->s_umount);
2619        return 0;
2620out_mntput:
2621        mntput(root_mnt);
2622out_err:
2623        return ret;
2624}
2625
2626static int nfs4_try_mount(int flags, const char *dev_name,
2627                         struct nfs_parsed_mount_data *data,
2628                         struct vfsmount *mnt)
2629{
2630        char *export_path;
2631        struct vfsmount *root_mnt;
2632        int error;
2633
2634        dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2635
2636        export_path = data->nfs_server.export_path;
2637        data->nfs_server.export_path = "/";
2638        root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2639                        data->nfs_server.hostname);
2640        data->nfs_server.export_path = export_path;
2641
2642        error = PTR_ERR(root_mnt);
2643        if (IS_ERR(root_mnt))
2644                goto out;
2645
2646        error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2647
2648out:
2649        dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2650                        error != 0 ? " [error]" : "");
2651        return error;
2652}
2653
2654/*
2655 * Get the superblock for an NFS4 mountpoint
2656 */
2657static int nfs4_get_sb(struct file_system_type *fs_type,
2658        int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2659{
2660        struct nfs_parsed_mount_data *data;
2661        int error = -ENOMEM;
2662
2663        data = nfs_alloc_parsed_mount_data(4);
2664        if (data == NULL)
2665                goto out_free_data;
2666
2667        /* Validate the mount data */
2668        error = nfs4_validate_mount_data(raw_data, data, dev_name);
2669        if (error < 0)
2670                goto out;
2671
2672        error = nfs4_try_mount(flags, dev_name, data, mnt);
2673
2674out:
2675        kfree(data->client_address);
2676        kfree(data->nfs_server.export_path);
2677        kfree(data->nfs_server.hostname);
2678        kfree(data->fscache_uniq);
2679out_free_data:
2680        kfree(data);
2681        dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2682                        error != 0 ? " [error]" : "");
2683        return error;
2684}
2685
2686static void nfs4_kill_super(struct super_block *sb)
2687{
2688        struct nfs_server *server = NFS_SB(sb);
2689
2690        dprintk("--> %s\n", __func__);
2691        nfs_super_return_all_delegations(sb);
2692        kill_anon_super(sb);
2693        nfs_fscache_release_super_cookie(sb);
2694        nfs_free_server(server);
2695        dprintk("<-- %s\n", __func__);
2696}
2697
2698/*
2699 * Clone an NFS4 server record on xdev traversal (FSID-change)
2700 */
2701static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2702                            const char *dev_name, void *raw_data,
2703                            struct vfsmount *mnt)
2704{
2705        struct nfs_clone_mount *data = raw_data;
2706        struct super_block *s;
2707        struct nfs_server *server;
2708        struct dentry *mntroot;
2709        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2710        struct nfs_sb_mountdata sb_mntdata = {
2711                .mntflags = flags,
2712        };
2713        int error;
2714
2715        dprintk("--> nfs4_xdev_get_sb()\n");
2716
2717        /* create a new volume representation */
2718        server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2719        if (IS_ERR(server)) {
2720                error = PTR_ERR(server);
2721                goto out_err_noserver;
2722        }
2723        sb_mntdata.server = server;
2724
2725        if (server->flags & NFS4_MOUNT_UNSHARED)
2726                compare_super = NULL;
2727
2728        /* Get a superblock - note that we may end up sharing one that already exists */
2729        s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2730        if (IS_ERR(s)) {
2731                error = PTR_ERR(s);
2732                goto out_err_nosb;
2733        }
2734
2735        if (s->s_fs_info != server) {
2736                nfs_free_server(server);
2737                server = NULL;
2738        } else {
2739                error = nfs_bdi_register(server);
2740                if (error)
2741                        goto error_splat_super;
2742        }
2743
2744        if (!s->s_root) {
2745                /* initial superblock/root creation */
2746                nfs4_clone_super(s, data->sb);
2747                nfs_fscache_get_super_cookie(s, NULL, data);
2748        }
2749
2750        mntroot = nfs4_get_root(s, data->fh);
2751        if (IS_ERR(mntroot)) {
2752                error = PTR_ERR(mntroot);
2753                goto error_splat_super;
2754        }
2755        if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2756                dput(mntroot);
2757                error = -ESTALE;
2758                goto error_splat_super;
2759        }
2760
2761        s->s_flags |= MS_ACTIVE;
2762        mnt->mnt_sb = s;
2763        mnt->mnt_root = mntroot;
2764
2765        security_sb_clone_mnt_opts(data->sb, s);
2766
2767        dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2768        return 0;
2769
2770out_err_nosb:
2771        nfs_free_server(server);
2772out_err_noserver:
2773        dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2774        return error;
2775
2776error_splat_super:
2777        deactivate_locked_super(s);
2778        dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2779        return error;
2780}
2781
2782static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2783                int flags, const char *dev_name, void *raw_data,
2784                struct vfsmount *mnt)
2785{
2786        struct nfs_clone_mount *data = raw_data;
2787        struct super_block *s;
2788        struct nfs_server *server;
2789        struct dentry *mntroot;
2790        struct nfs_fh mntfh;
2791        int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2792        struct nfs_sb_mountdata sb_mntdata = {
2793                .mntflags = flags,
2794        };
2795        int error;
2796
2797        dprintk("--> nfs4_referral_get_sb()\n");
2798
2799        /* create a new volume representation */
2800        server = nfs4_create_referral_server(data, &mntfh);
2801        if (IS_ERR(server)) {
2802                error = PTR_ERR(server);
2803                goto out_err_noserver;
2804        }
2805        sb_mntdata.server = server;
2806
2807        if (server->flags & NFS4_MOUNT_UNSHARED)
2808                compare_super = NULL;
2809
2810        /* Get a superblock - note that we may end up sharing one that already exists */
2811        s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2812        if (IS_ERR(s)) {
2813                error = PTR_ERR(s);
2814                goto out_err_nosb;
2815        }
2816
2817        if (s->s_fs_info != server) {
2818                nfs_free_server(server);
2819                server = NULL;
2820        } else {
2821                error = nfs_bdi_register(server);
2822                if (error)
2823                        goto error_splat_super;
2824        }
2825
2826        if (!s->s_root) {
2827                /* initial superblock/root creation */
2828                nfs4_fill_super(s);
2829                nfs_fscache_get_super_cookie(s, NULL, data);
2830        }
2831
2832        mntroot = nfs4_get_root(s, &mntfh);
2833        if (IS_ERR(mntroot)) {
2834                error = PTR_ERR(mntroot);
2835                goto error_splat_super;
2836        }
2837        if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2838                dput(mntroot);
2839                error = -ESTALE;
2840                goto error_splat_super;
2841        }
2842
2843        s->s_flags |= MS_ACTIVE;
2844        mnt->mnt_sb = s;
2845        mnt->mnt_root = mntroot;
2846
2847        security_sb_clone_mnt_opts(data->sb, s);
2848
2849        dprintk("<-- nfs4_referral_get_sb() = 0\n");
2850        return 0;
2851
2852out_err_nosb:
2853        nfs_free_server(server);
2854out_err_noserver:
2855        dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2856        return error;
2857
2858error_splat_super:
2859        deactivate_locked_super(s);
2860        dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2861        return error;
2862}
2863
2864/*
2865 * Create an NFS4 server record on referral traversal
2866 */
2867static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2868                int flags, const char *dev_name, void *raw_data,
2869                struct vfsmount *mnt)
2870{
2871        struct nfs_clone_mount *data = raw_data;
2872        char *export_path;
2873        struct vfsmount *root_mnt;
2874        int error;
2875
2876        dprintk("--> nfs4_referral_get_sb()\n");
2877
2878        export_path = data->mnt_path;
2879        data->mnt_path = "/";
2880
2881        root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2882                        flags, data, data->hostname);
2883        data->mnt_path = export_path;
2884
2885        error = PTR_ERR(root_mnt);
2886        if (IS_ERR(root_mnt))
2887                goto out;
2888
2889        error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2890out:
2891        dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2892                        error != 0 ? " [error]" : "");
2893        return error;
2894}
2895
2896#endif /* CONFIG_NFS_V4 */
2897