fs/nfs/super.c

   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 <linux/slab.h>
  52 #include <net/ipv6.h>
  53 #include <linux/netdevice.h>
  54 #include <linux/nfs_xdr.h>
  55 #include <linux/magic.h>
  56 #include <linux/parser.h>
  57
  58 #include <asm/system.h>
  59 #include <asm/uaccess.h>
  60
  61 #include "nfs4_fs.h"
  62 #include "callback.h"
  63 #include "delegation.h"
  64 #include "iostat.h"
  65 #include "internal.h"
  66 #include "fscache.h"
  67
  68 #define NFSDBG_FACILITY         NFSDBG_VFS
  69
  70 enum {
  71         /* Mount options that take no arguments */
  72         Opt_soft, Opt_hard,
  73         Opt_posix, Opt_noposix,
  74         Opt_cto, Opt_nocto,
  75         Opt_ac, Opt_noac,
  76         Opt_lock, Opt_nolock,
  77         Opt_v2, Opt_v3, Opt_v4,
  78         Opt_udp, Opt_tcp, Opt_rdma,
  79         Opt_acl, Opt_noacl,
  80         Opt_rdirplus, Opt_nordirplus,
  81         Opt_sharecache, Opt_nosharecache,
  82         Opt_resvport, Opt_noresvport,
  83         Opt_fscache, Opt_nofscache,
  84
  85         /* Mount options that take integer arguments */
  86         Opt_port,
  87         Opt_rsize, Opt_wsize, Opt_bsize,
  88         Opt_timeo, Opt_retrans,
  89         Opt_acregmin, Opt_acregmax,
  90         Opt_acdirmin, Opt_acdirmax,
  91         Opt_actimeo,
  92         Opt_namelen,
  93         Opt_mountport,
  94         Opt_mountvers,
  95         Opt_nfsvers,
  96         Opt_minorversion,
  97
  98         /* Mount options that take string arguments */
  99         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 100         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 101         Opt_lookupcache,
 102         Opt_fscache_uniq,
 103
 104         /* Special mount options */
 105         Opt_userspace, Opt_deprecated, Opt_sloppy,
 106
 107         Opt_err
 108 };
 109
 110 static const match_table_t nfs_mount_option_tokens = {
 111         { Opt_userspace, "bg" },
 112         { Opt_userspace, "fg" },
 113         { Opt_userspace, "retry=%s" },
 114
 115         { Opt_sloppy, "sloppy" },
 116
 117         { Opt_soft, "soft" },
 118         { Opt_hard, "hard" },
 119         { Opt_deprecated, "intr" },
 120         { Opt_deprecated, "nointr" },
 121         { Opt_posix, "posix" },
 122         { Opt_noposix, "noposix" },
 123         { Opt_cto, "cto" },
 124         { Opt_nocto, "nocto" },
 125         { Opt_ac, "ac" },
 126         { Opt_noac, "noac" },
 127         { Opt_lock, "lock" },
 128         { Opt_nolock, "nolock" },
 129         { Opt_v2, "v2" },
 130         { Opt_v3, "v3" },
 131         { Opt_v4, "v4" },
 132         { Opt_udp, "udp" },
 133         { Opt_tcp, "tcp" },
 134         { Opt_rdma, "rdma" },
 135         { Opt_acl, "acl" },
 136         { Opt_noacl, "noacl" },
 137         { Opt_rdirplus, "rdirplus" },
 138         { Opt_nordirplus, "nordirplus" },
 139         { Opt_sharecache, "sharecache" },
 140         { Opt_nosharecache, "nosharecache" },
 141         { Opt_resvport, "resvport" },
 142         { Opt_noresvport, "noresvport" },
 143         { Opt_fscache, "fsc" },
 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         { Opt_fscache_uniq, "fsc=%s" },
 174
 175         { Opt_err, NULL }
 176 };
 177
 178 enum {
 179         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 180
 181         Opt_xprt_err
 182 };
 183
 184 static const match_table_t nfs_xprt_protocol_tokens = {
 185         { Opt_xprt_udp, "udp" },
 186         { Opt_xprt_udp6, "udp6" },
 187         { Opt_xprt_tcp, "tcp" },
 188         { Opt_xprt_tcp6, "tcp6" },
 189         { Opt_xprt_rdma, "rdma" },
 190
 191         { Opt_xprt_err, NULL }
 192 };
 193
 194 enum {
 195         Opt_sec_none, Opt_sec_sys,
 196         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 197         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 198         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 199
 200         Opt_sec_err
 201 };
 202
 203 static const match_table_t nfs_secflavor_tokens = {
 204         { Opt_sec_none, "none" },
 205         { Opt_sec_none, "null" },
 206         { Opt_sec_sys, "sys" },
 207
 208         { Opt_sec_krb5, "krb5" },
 209         { Opt_sec_krb5i, "krb5i" },
 210         { Opt_sec_krb5p, "krb5p" },
 211
 212         { Opt_sec_lkey, "lkey" },
 213         { Opt_sec_lkeyi, "lkeyi" },
 214         { Opt_sec_lkeyp, "lkeyp" },
 215
 216         { Opt_sec_spkm, "spkm3" },
 217         { Opt_sec_spkmi, "spkm3i" },
 218         { Opt_sec_spkmp, "spkm3p" },
 219
 220         { Opt_sec_err, NULL }
 221 };
 222
 223 enum {
 224         Opt_lookupcache_all, Opt_lookupcache_positive,
 225         Opt_lookupcache_none,
 226
 227         Opt_lookupcache_err
 228 };
 229
 230 static match_table_t nfs_lookupcache_tokens = {
 231         { Opt_lookupcache_all, "all" },
 232         { Opt_lookupcache_positive, "pos" },
 233         { Opt_lookupcache_positive, "positive" },
 234         { Opt_lookupcache_none, "none" },
 235
 236         { Opt_lookupcache_err, NULL }
 237 };
 238
 239
 240 static void nfs_umount_begin(struct super_block *);
 241 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 242 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 243 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 244 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 245 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 246                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 247 static void nfs_put_super(struct super_block *);
 248 static void nfs_kill_super(struct super_block *);
 249 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 250
 251 static struct file_system_type nfs_fs_type = {
 252         .owner          = THIS_MODULE,
 253         .name           = "nfs",
 254         .get_sb         = nfs_get_sb,
 255         .kill_sb        = nfs_kill_super,
 256         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 257 };
 258
 259 struct file_system_type nfs_xdev_fs_type = {
 260         .owner          = THIS_MODULE,
 261         .name           = "nfs",
 262         .get_sb         = nfs_xdev_get_sb,
 263         .kill_sb        = nfs_kill_super,
 264         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 265 };
 266
 267 static const struct super_operations nfs_sops = {
 268         .alloc_inode    = nfs_alloc_inode,
 269         .destroy_inode  = nfs_destroy_inode,
 270         .write_inode    = nfs_write_inode,
 271         .put_super      = nfs_put_super,
 272         .statfs         = nfs_statfs,
 273         .clear_inode    = nfs_clear_inode,
 274         .umount_begin   = nfs_umount_begin,
 275         .show_options   = nfs_show_options,
 276         .show_stats     = nfs_show_stats,
 277         .remount_fs     = nfs_remount,
 278 };
 279
 280 #ifdef CONFIG_NFS_V4
 281 static int nfs4_validate_text_mount_data(void *options,
 282         struct nfs_parsed_mount_data *args, const char *dev_name);
 283 static int nfs4_try_mount(int flags, const char *dev_name,
 284         struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
 285 static int nfs4_get_sb(struct file_system_type *fs_type,
 286         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 287 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 288         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 289 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 290         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 291 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 292         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 293 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
 294         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 295 static void nfs4_kill_super(struct super_block *sb);
 296
 297 static struct file_system_type nfs4_fs_type = {
 298         .owner          = THIS_MODULE,
 299         .name           = "nfs4",
 300         .get_sb         = nfs4_get_sb,
 301         .kill_sb        = nfs4_kill_super,
 302         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 303 };
 304
 305 static struct file_system_type nfs4_remote_fs_type = {
 306         .owner          = THIS_MODULE,
 307         .name           = "nfs4",
 308         .get_sb         = nfs4_remote_get_sb,
 309         .kill_sb        = nfs4_kill_super,
 310         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 311 };
 312
 313 struct file_system_type nfs4_xdev_fs_type = {
 314         .owner          = THIS_MODULE,
 315         .name           = "nfs4",
 316         .get_sb         = nfs4_xdev_get_sb,
 317         .kill_sb        = nfs4_kill_super,
 318         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 319 };
 320
 321 static struct file_system_type nfs4_remote_referral_fs_type = {
 322         .owner          = THIS_MODULE,
 323         .name           = "nfs4",
 324         .get_sb         = nfs4_remote_referral_get_sb,
 325         .kill_sb        = nfs4_kill_super,
 326         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 327 };
 328
 329 struct file_system_type nfs4_referral_fs_type = {
 330         .owner          = THIS_MODULE,
 331         .name           = "nfs4",
 332         .get_sb         = nfs4_referral_get_sb,
 333         .kill_sb        = nfs4_kill_super,
 334         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 335 };
 336
 337 static const struct super_operations nfs4_sops = {
 338         .alloc_inode    = nfs_alloc_inode,
 339         .destroy_inode  = nfs_destroy_inode,
 340         .write_inode    = nfs_write_inode,
 341         .put_super      = nfs_put_super,
 342         .statfs         = nfs_statfs,
 343         .clear_inode    = nfs4_clear_inode,
 344         .umount_begin   = nfs_umount_begin,
 345         .show_options   = nfs_show_options,
 346         .show_stats     = nfs_show_stats,
 347         .remount_fs     = nfs_remount,
 348 };
 349 #endif
 350
 351 static struct shrinker acl_shrinker = {
 352         .shrink         = nfs_access_cache_shrinker,
 353         .seeks          = DEFAULT_SEEKS,
 354 };
 355
 356 /*
 357  * Register the NFS filesystems
 358  */
 359 int __init register_nfs_fs(void)
 360 {
 361         int ret;
 362
 363         ret = register_filesystem(&nfs_fs_type);
 364         if (ret < 0)
 365                 goto error_0;
 366
 367         ret = nfs_register_sysctl();
 368         if (ret < 0)
 369                 goto error_1;
 370 #ifdef CONFIG_NFS_V4
 371         ret = register_filesystem(&nfs4_fs_type);
 372         if (ret < 0)
 373                 goto error_2;
 374 #endif
 375         register_shrinker(&acl_shrinker);
 376         return 0;
 377
 378 #ifdef CONFIG_NFS_V4
 379 error_2:
 380         nfs_unregister_sysctl();
 381 #endif
 382 error_1:
 383         unregister_filesystem(&nfs_fs_type);
 384 error_0:
 385         return ret;
 386 }
 387
 388 /*
 389  * Unregister the NFS filesystems
 390  */
 391 void __exit unregister_nfs_fs(void)
 392 {
 393         unregister_shrinker(&acl_shrinker);
 394 #ifdef CONFIG_NFS_V4
 395         unregister_filesystem(&nfs4_fs_type);
 396 #endif
 397         nfs_unregister_sysctl();
 398         unregister_filesystem(&nfs_fs_type);
 399 }
 400
 401 void nfs_sb_active(struct super_block *sb)
 402 {
 403         struct nfs_server *server = NFS_SB(sb);
 404
 405         if (atomic_inc_return(&server->active) == 1)
 406                 atomic_inc(&sb->s_active);
 407 }
 408
 409 void nfs_sb_deactive(struct super_block *sb)
 410 {
 411         struct nfs_server *server = NFS_SB(sb);
 412
 413         if (atomic_dec_and_test(&server->active))
 414                 deactivate_super(sb);
 415 }
 416
 417 /*
 418  * Deliver file system statistics to userspace
 419  */
 420 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 421 {
 422         struct nfs_server *server = NFS_SB(dentry->d_sb);
 423         unsigned char blockbits;
 424         unsigned long blockres;
 425         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 426         struct nfs_fsstat res;
 427         int error = -ENOMEM;
 428
 429         res.fattr = nfs_alloc_fattr();
 430         if (res.fattr == NULL)
 431                 goto out_err;
 432
 433         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 434
 435         nfs_free_fattr(res.fattr);
 436         if (error < 0)
 437                 goto out_err;
 438
 439         buf->f_type = NFS_SUPER_MAGIC;
 440
 441         /*
 442          * Current versions of glibc do not correctly handle the
 443          * case where f_frsize != f_bsize.  Eventually we want to
 444          * report the value of wtmult in this field.
 445          */
 446         buf->f_frsize = dentry->d_sb->s_blocksize;
 447
 448         /*
 449          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 450          * are reported in units of f_frsize.  Linux hasn't had
 451          * an f_frsize field in its statfs struct until recently,
 452          * thus historically Linux's sys_statfs reports these
 453          * fields in units of f_bsize.
 454          */
 455         buf->f_bsize = dentry->d_sb->s_blocksize;
 456         blockbits = dentry->d_sb->s_blocksize_bits;
 457         blockres = (1 << blockbits) - 1;
 458         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 459         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 460         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 461
 462         buf->f_files = res.tfiles;
 463         buf->f_ffree = res.afiles;
 464
 465         buf->f_namelen = server->namelen;
 466
 467         return 0;
 468
 469  out_err:
 470         dprintk("%s: statfs error = %d\n", __func__, -error);
 471         return error;
 472 }
 473
 474 /*
 475  * Map the security flavour number to a name
 476  */
 477 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 478 {
 479         static const struct {
 480                 rpc_authflavor_t flavour;
 481                 const char *str;
 482         } sec_flavours[] = {
 483                 { RPC_AUTH_NULL, "null" },
 484                 { RPC_AUTH_UNIX, "sys" },
 485                 { RPC_AUTH_GSS_KRB5, "krb5" },
 486                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 487                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 488                 { RPC_AUTH_GSS_LKEY, "lkey" },
 489                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 490                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 491                 { RPC_AUTH_GSS_SPKM, "spkm" },
 492                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 493                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 494                 { UINT_MAX, "unknown" }
 495         };
 496         int i;
 497
 498         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 499                 if (sec_flavours[i].flavour == flavour)
 500                         break;
 501         }
 502         return sec_flavours[i].str;
 503 }
 504
 505 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 506                                   int showdefaults)
 507 {
 508         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 509
 510         seq_printf(m, ",mountproto=");
 511         switch (sap->sa_family) {
 512         case AF_INET:
 513                 switch (nfss->mountd_protocol) {
 514                 case IPPROTO_UDP:
 515                         seq_printf(m, RPCBIND_NETID_UDP);
 516                         break;
 517                 case IPPROTO_TCP:
 518                         seq_printf(m, RPCBIND_NETID_TCP);
 519                         break;
 520                 default:
 521                         if (showdefaults)
 522                                 seq_printf(m, "auto");
 523                 }
 524                 break;
 525         case AF_INET6:
 526                 switch (nfss->mountd_protocol) {
 527                 case IPPROTO_UDP:
 528                         seq_printf(m, RPCBIND_NETID_UDP6);
 529                         break;
 530                 case IPPROTO_TCP:
 531                         seq_printf(m, RPCBIND_NETID_TCP6);
 532                         break;
 533                 default:
 534                         if (showdefaults)
 535                                 seq_printf(m, "auto");
 536                 }
 537                 break;
 538         default:
 539                 if (showdefaults)
 540                         seq_printf(m, "auto");
 541         }
 542 }
 543
 544 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 545                                     int showdefaults)
 546 {
 547         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 548
 549         switch (sap->sa_family) {
 550         case AF_INET: {
 551                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 552                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 553                 break;
 554         }
 555         case AF_INET6: {
 556                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 557                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 558                 break;
 559         }
 560         default:
 561                 if (showdefaults)
 562                         seq_printf(m, ",mountaddr=unspecified");
 563         }
 564
 565         if (nfss->mountd_version || showdefaults)
 566                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 567         if (nfss->mountd_port || showdefaults)
 568                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 569
 570         nfs_show_mountd_netid(m, nfss, showdefaults);
 571 }
 572
 573 #ifdef CONFIG_NFS_V4
 574 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 575                                     int showdefaults)
 576 {
 577         struct nfs_client *clp = nfss->nfs_client;
 578
 579         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 580         seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
 581 }
 582 #else
 583 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 584                                     int showdefaults)
 585 {
 586 }
 587 #endif
 588
 589 /*
 590  * Describe the mount options in force on this server representation
 591  */
 592 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 593                                    int showdefaults)
 594 {
 595         static const struct proc_nfs_info {
 596                 int flag;
 597                 const char *str;
 598                 const char *nostr;
 599         } nfs_info[] = {
 600                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 601                 { NFS_MOUNT_POSIX, ",posix", "" },
 602                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 603                 { NFS_MOUNT_NOAC, ",noac", "" },
 604                 { NFS_MOUNT_NONLM, ",nolock", "" },
 605                 { NFS_MOUNT_NOACL, ",noacl", "" },
 606                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 607                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 608                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 609                 { 0, NULL, NULL }
 610         };
 611         const struct proc_nfs_info *nfs_infop;
 612         struct nfs_client *clp = nfss->nfs_client;
 613         u32 version = clp->rpc_ops->version;
 614
 615         seq_printf(m, ",vers=%u", version);
 616         seq_printf(m, ",rsize=%u", nfss->rsize);
 617         seq_printf(m, ",wsize=%u", nfss->wsize);
 618         if (nfss->bsize != 0)
 619                 seq_printf(m, ",bsize=%u", nfss->bsize);
 620         seq_printf(m, ",namlen=%u", nfss->namelen);
 621         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 622                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 623         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 624                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 625         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 626                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 627         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 628                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 629         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 630                 if (nfss->flags & nfs_infop->flag)
 631                         seq_puts(m, nfs_infop->str);
 632                 else
 633                         seq_puts(m, nfs_infop->nostr);
 634         }
 635         seq_printf(m, ",proto=%s",
 636                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 637         if (version == 4) {
 638                 if (nfss->port != NFS_PORT)
 639                         seq_printf(m, ",port=%u", nfss->port);
 640         } else
 641                 if (nfss->port)
 642                         seq_printf(m, ",port=%u", nfss->port);
 643
 644         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 645         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 646         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 647
 648         if (version != 4)
 649                 nfs_show_mountd_options(m, nfss, showdefaults);
 650         else
 651                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 652
 653         if (nfss->options & NFS_OPTION_FSCACHE)
 654                 seq_printf(m, ",fsc");
 655 }
 656
 657 /*
 658  * Describe the mount options on this VFS mountpoint
 659  */
 660 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 661 {
 662         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 663
 664         nfs_show_mount_options(m, nfss, 0);
 665
 666         seq_printf(m, ",addr=%s",
 667                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 668                                                         RPC_DISPLAY_ADDR));
 669
 670         return 0;
 671 }
 672
 673 /*
 674  * Present statistical information for this VFS mountpoint
 675  */
 676 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 677 {
 678         int i, cpu;
 679         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 680         struct rpc_auth *auth = nfss->client->cl_auth;
 681         struct nfs_iostats totals = { };
 682
 683         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 684
 685         /*
 686          * Display all mount option settings
 687          */
 688         seq_printf(m, "\n\topts:\t");
 689         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 690         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 691         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 692         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 693         nfs_show_mount_options(m, nfss, 1);
 694
 695         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 696
 697         seq_printf(m, "\n\tcaps:\t");
 698         seq_printf(m, "caps=0x%x", nfss->caps);
 699         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 700         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 701         seq_printf(m, ",bsize=%u", nfss->bsize);
 702         seq_printf(m, ",namlen=%u", nfss->namelen);
 703
 704 #ifdef CONFIG_NFS_V4
 705         if (nfss->nfs_client->rpc_ops->version == 4) {
 706                 seq_printf(m, "\n\tnfsv4:\t");
 707                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 708                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 709                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 710         }
 711 #endif
 712
 713         /*
 714          * Display security flavor in effect for this mount
 715          */
 716         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 717         if (auth->au_flavor)
 718                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 719
 720         /*
 721          * Display superblock I/O counters
 722          */
 723         for_each_possible_cpu(cpu) {
 724                 struct nfs_iostats *stats;
 725
 726                 preempt_disable();
 727                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 728
 729                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 730                         totals.events[i] += stats->events[i];
 731                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 732                         totals.bytes[i] += stats->bytes[i];
 733 #ifdef CONFIG_NFS_FSCACHE
 734                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 735                         totals.fscache[i] += stats->fscache[i];
 736 #endif
 737
 738                 preempt_enable();
 739         }
 740
 741         seq_printf(m, "\n\tevents:\t");
 742         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 743                 seq_printf(m, "%lu ", totals.events[i]);
 744         seq_printf(m, "\n\tbytes:\t");
 745         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 746                 seq_printf(m, "%Lu ", totals.bytes[i]);
 747 #ifdef CONFIG_NFS_FSCACHE
 748         if (nfss->options & NFS_OPTION_FSCACHE) {
 749                 seq_printf(m, "\n\tfsc:\t");
 750                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 751                         seq_printf(m, "%Lu ", totals.bytes[i]);
 752         }
 753 #endif
 754         seq_printf(m, "\n");
 755
 756         rpc_print_iostats(m, nfss->client);
 757
 758         return 0;
 759 }
 760
 761 /*
 762  * Begin unmount by attempting to remove all automounted mountpoints we added
 763  * in response to xdev traversals and referrals
 764  */
 765 static void nfs_umount_begin(struct super_block *sb)
 766 {
 767         struct nfs_server *server;
 768         struct rpc_clnt *rpc;
 769
 770         server = NFS_SB(sb);
 771         /* -EIO all pending I/O */
 772         rpc = server->client_acl;
 773         if (!IS_ERR(rpc))
 774                 rpc_killall_tasks(rpc);
 775         rpc = server->client;
 776         if (!IS_ERR(rpc))
 777                 rpc_killall_tasks(rpc);
 778 }
 779
 780 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 781 {
 782         struct nfs_parsed_mount_data *data;
 783
 784         data = kzalloc(sizeof(*data), GFP_KERNEL);
 785         if (data) {
 786                 data->acregmin          = NFS_DEF_ACREGMIN;
 787                 data->acregmax          = NFS_DEF_ACREGMAX;
 788                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 789                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 790                 data->mount_server.port = NFS_UNSPEC_PORT;
 791                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 792                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 793                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 794                 data->auth_flavor_len   = 1;
 795                 data->version           = version;
 796                 data->minorversion      = 0;
 797         }
 798         return data;
 799 }
 800
 801 /*
 802  * Sanity-check a server address provided by the mount command.
 803  *
 804  * Address family must be initialized, and address must not be
 805  * the ANY address for that family.
 806  */
 807 static int nfs_verify_server_address(struct sockaddr *addr)
 808 {
 809         switch (addr->sa_family) {
 810         case AF_INET: {
 811                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 812                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 813         }
 814         case AF_INET6: {
 815                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 816                 return !ipv6_addr_any(sa);
 817         }
 818         }
 819
 820         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 821         return 0;
 822 }
 823
 824 /*
 825  * Select between a default port value and a user-specified port value.
 826  * If a zero value is set, then autobind will be used.
 827  */
 828 static void nfs_set_port(struct sockaddr *sap, int *port,
 829                                  const unsigned short default_port)
 830 {
 831         if (*port == NFS_UNSPEC_PORT)
 832                 *port = default_port;
 833
 834         rpc_set_port(sap, *port);
 835 }
 836
 837 /*
 838  * Sanity check the NFS transport protocol.
 839  *
 840  */
 841 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 842 {
 843         switch (mnt->nfs_server.protocol) {
 844         case XPRT_TRANSPORT_UDP:
 845         case XPRT_TRANSPORT_TCP:
 846         case XPRT_TRANSPORT_RDMA:
 847                 break;
 848         default:
 849                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 850         }
 851 }
 852
 853 /*
 854  * For text based NFSv2/v3 mounts, the mount protocol transport default
 855  * settings should depend upon the specified NFS transport.
 856  */
 857 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 858 {
 859         nfs_validate_transport_protocol(mnt);
 860
 861         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 862             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 863                         return;
 864         switch (mnt->nfs_server.protocol) {
 865         case XPRT_TRANSPORT_UDP:
 866                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 867                 break;
 868         case XPRT_TRANSPORT_TCP:
 869         case XPRT_TRANSPORT_RDMA:
 870                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 871         }
 872 }
 873
 874 /*
 875  * Parse the value of the 'sec=' option.
 876  */
 877 static int nfs_parse_security_flavors(char *value,
 878                                       struct nfs_parsed_mount_data *mnt)
 879 {
 880         substring_t args[MAX_OPT_ARGS];
 881
 882         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 883
 884         switch (match_token(value, nfs_secflavor_tokens, args)) {
 885         case Opt_sec_none:
 886                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 887                 break;
 888         case Opt_sec_sys:
 889                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 890                 break;
 891         case Opt_sec_krb5:
 892                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 893                 break;
 894         case Opt_sec_krb5i:
 895                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 896                 break;
 897         case Opt_sec_krb5p:
 898                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 899                 break;
 900         case Opt_sec_lkey:
 901                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 902                 break;
 903         case Opt_sec_lkeyi:
 904                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 905                 break;
 906         case Opt_sec_lkeyp:
 907                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 908                 break;
 909         case Opt_sec_spkm:
 910                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 911                 break;
 912         case Opt_sec_spkmi:
 913                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 914                 break;
 915         case Opt_sec_spkmp:
 916                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 917                 break;
 918         default:
 919                 return 0;
 920         }
 921
 922         mnt->auth_flavor_len = 1;
 923         return 1;
 924 }
 925
 926 /*
 927  * Error-check and convert a string of mount options from user space into
 928  * a data structure.  The whole mount string is processed; bad options are
 929  * skipped as they are encountered.  If there were no errors, return 1;
 930  * otherwise return 0 (zero).
 931  */
 932 static int nfs_parse_mount_options(char *raw,
 933                                    struct nfs_parsed_mount_data *mnt)
 934 {
 935         char *p, *string, *secdata;
 936         int rc, sloppy = 0, invalid_option = 0;
 937         unsigned short protofamily = AF_UNSPEC;
 938         unsigned short mountfamily = AF_UNSPEC;
 939
 940         if (!raw) {
 941                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 942                 return 1;
 943         }
 944         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 945
 946         secdata = alloc_secdata();
 947         if (!secdata)
 948                 goto out_nomem;
 949
 950         rc = security_sb_copy_data(raw, secdata);
 951         if (rc)
 952                 goto out_security_failure;
 953
 954         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 955         if (rc)
 956                 goto out_security_failure;
 957
 958         free_secdata(secdata);
 959
 960         while ((p = strsep(&raw, ",")) != NULL) {
 961                 substring_t args[MAX_OPT_ARGS];
 962                 unsigned long option;
 963                 int token;
 964
 965                 if (!*p)
 966                         continue;
 967
 968                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 969
 970                 token = match_token(p, nfs_mount_option_tokens, args);
 971                 switch (token) {
 972
 973                 /*
 974                  * boolean options:  foo/nofoo
 975                  */
 976                 case Opt_soft:
 977                         mnt->flags |= NFS_MOUNT_SOFT;
 978                         break;
 979                 case Opt_hard:
 980                         mnt->flags &= ~NFS_MOUNT_SOFT;
 981                         break;
 982                 case Opt_posix:
 983                         mnt->flags |= NFS_MOUNT_POSIX;
 984                         break;
 985                 case Opt_noposix:
 986                         mnt->flags &= ~NFS_MOUNT_POSIX;
 987                         break;
 988                 case Opt_cto:
 989                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 990                         break;
 991                 case Opt_nocto:
 992                         mnt->flags |= NFS_MOUNT_NOCTO;
 993                         break;
 994                 case Opt_ac:
 995                         mnt->flags &= ~NFS_MOUNT_NOAC;
 996                         break;
 997                 case Opt_noac:
 998                         mnt->flags |= NFS_MOUNT_NOAC;
 999                         break;
1000                 case Opt_lock:
1001                         mnt->flags &= ~NFS_MOUNT_NONLM;
1002                         break;
1003                 case Opt_nolock:
1004                         mnt->flags |= NFS_MOUNT_NONLM;
1005                         break;
1006                 case Opt_v2:
1007                         mnt->flags &= ~NFS_MOUNT_VER3;
1008                         mnt->version = 2;
1009                         break;
1010                 case Opt_v3:
1011                         mnt->flags |= NFS_MOUNT_VER3;
1012                         mnt->version = 3;
1013                         break;
1014 #ifdef CONFIG_NFS_V4
1015                 case Opt_v4:
1016                         mnt->flags &= ~NFS_MOUNT_VER3;
1017                         mnt->version = 4;
1018                         break;
1019 #endif
1020                 case Opt_udp:
1021                         mnt->flags &= ~NFS_MOUNT_TCP;
1022                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1023                         break;
1024                 case Opt_tcp:
1025                         mnt->flags |= NFS_MOUNT_TCP;
1026                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1027                         break;
1028                 case Opt_rdma:
1029                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1030                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1031                         xprt_load_transport(p);
1032                         break;
1033                 case Opt_acl:
1034                         mnt->flags &= ~NFS_MOUNT_NOACL;
1035                         break;
1036                 case Opt_noacl:
1037                         mnt->flags |= NFS_MOUNT_NOACL;
1038                         break;
1039                 case Opt_rdirplus:
1040                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1041                         break;
1042                 case Opt_nordirplus:
1043                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1044                         break;
1045                 case Opt_sharecache:
1046                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1047                         break;
1048                 case Opt_nosharecache:
1049                         mnt->flags |= NFS_MOUNT_UNSHARED;
1050                         break;
1051                 case Opt_resvport:
1052                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1053                         break;
1054                 case Opt_noresvport:
1055                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1056                         break;
1057                 case Opt_fscache:
1058                         mnt->options |= NFS_OPTION_FSCACHE;
1059                         kfree(mnt->fscache_uniq);
1060                         mnt->fscache_uniq = NULL;
1061                         break;
1062                 case Opt_nofscache:
1063                         mnt->options &= ~NFS_OPTION_FSCACHE;
1064                         kfree(mnt->fscache_uniq);
1065                         mnt->fscache_uniq = NULL;
1066                         break;
1067
1068                 /*
1069                  * options that take numeric values
1070                  */
1071                 case Opt_port:
1072                         string = match_strdup(args);
1073                         if (string == NULL)
1074                                 goto out_nomem;
1075                         rc = strict_strtoul(string, 10, &option);
1076                         kfree(string);
1077                         if (rc != 0 || option > USHRT_MAX)
1078                                 goto out_invalid_value;
1079                         mnt->nfs_server.port = option;
1080                         break;
1081                 case Opt_rsize:
1082                         string = match_strdup(args);
1083                         if (string == NULL)
1084                                 goto out_nomem;
1085                         rc = strict_strtoul(string, 10, &option);
1086                         kfree(string);
1087                         if (rc != 0)
1088                                 goto out_invalid_value;
1089                         mnt->rsize = option;
1090                         break;
1091                 case Opt_wsize:
1092                         string = match_strdup(args);
1093                         if (string == NULL)
1094                                 goto out_nomem;
1095                         rc = strict_strtoul(string, 10, &option);
1096                         kfree(string);
1097                         if (rc != 0)
1098                                 goto out_invalid_value;
1099                         mnt->wsize = option;
1100                         break;
1101                 case Opt_bsize:
1102                         string = match_strdup(args);
1103                         if (string == NULL)
1104                                 goto out_nomem;
1105                         rc = strict_strtoul(string, 10, &option);
1106                         kfree(string);
1107                         if (rc != 0)
1108                                 goto out_invalid_value;
1109                         mnt->bsize = option;
1110                         break;
1111                 case Opt_timeo:
1112                         string = match_strdup(args);
1113                         if (string == NULL)
1114                                 goto out_nomem;
1115                         rc = strict_strtoul(string, 10, &option);
1116                         kfree(string);
1117                         if (rc != 0 || option == 0)
1118                                 goto out_invalid_value;
1119                         mnt->timeo = option;
1120                         break;
1121                 case Opt_retrans:
1122                         string = match_strdup(args);
1123                         if (string == NULL)
1124                                 goto out_nomem;
1125                         rc = strict_strtoul(string, 10, &option);
1126                         kfree(string);
1127                         if (rc != 0 || option == 0)
1128                                 goto out_invalid_value;
1129                         mnt->retrans = option;
1130                         break;
1131                 case Opt_acregmin:
1132                         string = match_strdup(args);
1133                         if (string == NULL)
1134                                 goto out_nomem;
1135                         rc = strict_strtoul(string, 10, &option);
1136                         kfree(string);
1137                         if (rc != 0)
1138                                 goto out_invalid_value;
1139                         mnt->acregmin = option;
1140                         break;
1141                 case Opt_acregmax:
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->acregmax = option;
1150                         break;
1151                 case Opt_acdirmin:
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)
1158                                 goto out_invalid_value;
1159                         mnt->acdirmin = option;
1160                         break;
1161                 case Opt_acdirmax:
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                                 goto out_invalid_value;
1169                         mnt->acdirmax = option;
1170                         break;
1171                 case Opt_actimeo:
1172                         string = match_strdup(args);
1173                         if (string == NULL)
1174                                 goto out_nomem;
1175                         rc = strict_strtoul(string, 10, &option);
1176                         kfree(string);
1177                         if (rc != 0)
1178                                 goto out_invalid_value;
1179                         mnt->acregmin = mnt->acregmax =
1180                         mnt->acdirmin = mnt->acdirmax = option;
1181                         break;
1182                 case Opt_namelen:
1183                         string = match_strdup(args);
1184                         if (string == NULL)
1185                                 goto out_nomem;
1186                         rc = strict_strtoul(string, 10, &option);
1187                         kfree(string);
1188                         if (rc != 0)
1189                                 goto out_invalid_value;
1190                         mnt->namlen = option;
1191                         break;
1192                 case Opt_mountport:
1193                         string = match_strdup(args);
1194                         if (string == NULL)
1195                                 goto out_nomem;
1196                         rc = strict_strtoul(string, 10, &option);
1197                         kfree(string);
1198                         if (rc != 0 || option > USHRT_MAX)
1199                                 goto out_invalid_value;
1200                         mnt->mount_server.port = option;
1201                         break;
1202                 case Opt_mountvers:
1203                         string = match_strdup(args);
1204                         if (string == NULL)
1205                                 goto out_nomem;
1206                         rc = strict_strtoul(string, 10, &option);
1207                         kfree(string);
1208                         if (rc != 0 ||
1209                             option < NFS_MNT_VERSION ||
1210                             option > NFS_MNT3_VERSION)
1211                                 goto out_invalid_value;
1212                         mnt->mount_server.version = option;
1213                         break;
1214                 case Opt_nfsvers:
1215                         string = match_strdup(args);
1216                         if (string == NULL)
1217                                 goto out_nomem;
1218                         rc = strict_strtoul(string, 10, &option);
1219                         kfree(string);
1220                         if (rc != 0)
1221                                 goto out_invalid_value;
1222                         switch (option) {
1223                         case NFS2_VERSION:
1224                                 mnt->flags &= ~NFS_MOUNT_VER3;
1225                                 mnt->version = 2;
1226                                 break;
1227                         case NFS3_VERSION:
1228                                 mnt->flags |= NFS_MOUNT_VER3;
1229                                 mnt->version = 3;
1230                                 break;
1231 #ifdef CONFIG_NFS_V4
1232                         case NFS4_VERSION:
1233                                 mnt->flags &= ~NFS_MOUNT_VER3;
1234                                 mnt->version = 4;
1235                                 break;
1236 #endif
1237                         default:
1238                                 goto out_invalid_value;
1239                         }
1240                         break;
1241                 case Opt_minorversion:
1242                         string = match_strdup(args);
1243                         if (string == NULL)
1244                                 goto out_nomem;
1245                         rc = strict_strtoul(string, 10, &option);
1246                         kfree(string);
1247                         if (rc != 0)
1248                                 goto out_invalid_value;
1249                         if (option > NFS4_MAX_MINOR_VERSION)
1250                                 goto out_invalid_value;
1251                         mnt->minorversion = option;
1252                         break;
1253
1254                 /*
1255                  * options that take text values
1256                  */
1257                 case Opt_sec:
1258                         string = match_strdup(args);
1259                         if (string == NULL)
1260                                 goto out_nomem;
1261                         rc = nfs_parse_security_flavors(string, mnt);
1262                         kfree(string);
1263                         if (!rc) {
1264                                 dfprintk(MOUNT, "NFS:   unrecognized "
1265                                                 "security flavor\n");
1266                                 return 0;
1267                         }
1268                         break;
1269                 case Opt_proto:
1270                         string = match_strdup(args);
1271                         if (string == NULL)
1272                                 goto out_nomem;
1273                         token = match_token(string,
1274                                             nfs_xprt_protocol_tokens, args);
1275
1276                         protofamily = AF_INET;
1277                         switch (token) {
1278                         case Opt_xprt_udp6:
1279                                 protofamily = AF_INET6;
1280                         case Opt_xprt_udp:
1281                                 mnt->flags &= ~NFS_MOUNT_TCP;
1282                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1283                                 kfree(string);
1284                                 break;
1285                         case Opt_xprt_tcp6:
1286                                 protofamily = AF_INET6;
1287                         case Opt_xprt_tcp:
1288                                 mnt->flags |= NFS_MOUNT_TCP;
1289                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1290                                 kfree(string);
1291                                 break;
1292                         case Opt_xprt_rdma:
1293                                 /* vector side protocols to TCP */
1294                                 mnt->flags |= NFS_MOUNT_TCP;
1295                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1296                                 xprt_load_transport(string);
1297                                 kfree(string);
1298                                 break;
1299                         default:
1300                                 dfprintk(MOUNT, "NFS:   unrecognized "
1301                                                 "transport protocol\n");
1302                                 kfree(string);
1303                                 return 0;
1304                         }
1305                         break;
1306                 case Opt_mountproto:
1307                         string = match_strdup(args);
1308                         if (string == NULL)
1309                                 goto out_nomem;
1310                         token = match_token(string,
1311                                             nfs_xprt_protocol_tokens, args);
1312                         kfree(string);
1313
1314                         mountfamily = AF_INET;
1315                         switch (token) {
1316                         case Opt_xprt_udp6:
1317                                 mountfamily = AF_INET6;
1318                         case Opt_xprt_udp:
1319                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1320                                 break;
1321                         case Opt_xprt_tcp6:
1322                                 mountfamily = AF_INET6;
1323                         case Opt_xprt_tcp:
1324                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1325                                 break;
1326                         case Opt_xprt_rdma: /* not used for side protocols */
1327                         default:
1328                                 dfprintk(MOUNT, "NFS:   unrecognized "
1329                                                 "transport protocol\n");
1330                                 return 0;
1331                         }
1332                         break;
1333                 case Opt_addr:
1334                         string = match_strdup(args);
1335                         if (string == NULL)
1336                                 goto out_nomem;
1337                         mnt->nfs_server.addrlen =
1338                                 rpc_pton(string, strlen(string),
1339                                         (struct sockaddr *)
1340                                         &mnt->nfs_server.address,
1341                                         sizeof(mnt->nfs_server.address));
1342                         kfree(string);
1343                         if (mnt->nfs_server.addrlen == 0)
1344                                 goto out_invalid_address;
1345                         break;
1346                 case Opt_clientaddr:
1347                         string = match_strdup(args);
1348                         if (string == NULL)
1349                                 goto out_nomem;
1350                         kfree(mnt->client_address);
1351                         mnt->client_address = string;
1352                         break;
1353                 case Opt_mounthost:
1354                         string = match_strdup(args);
1355                         if (string == NULL)
1356                                 goto out_nomem;
1357                         kfree(mnt->mount_server.hostname);
1358                         mnt->mount_server.hostname = string;
1359                         break;
1360                 case Opt_mountaddr:
1361                         string = match_strdup(args);
1362                         if (string == NULL)
1363                                 goto out_nomem;
1364                         mnt->mount_server.addrlen =
1365                                 rpc_pton(string, strlen(string),
1366                                         (struct sockaddr *)
1367                                         &mnt->mount_server.address,
1368                                         sizeof(mnt->mount_server.address));
1369                         kfree(string);
1370                         if (mnt->mount_server.addrlen == 0)
1371                                 goto out_invalid_address;
1372                         break;
1373                 case Opt_lookupcache:
1374                         string = match_strdup(args);
1375                         if (string == NULL)
1376                                 goto out_nomem;
1377                         token = match_token(string,
1378                                         nfs_lookupcache_tokens, args);
1379                         kfree(string);
1380                         switch (token) {
1381                                 case Opt_lookupcache_all:
1382                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1383                                         break;
1384                                 case Opt_lookupcache_positive:
1385                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1386                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1387                                         break;
1388                                 case Opt_lookupcache_none:
1389                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1390                                         break;
1391                                 default:
1392                                         dfprintk(MOUNT, "NFS:   invalid "
1393                                                         "lookupcache argument\n");
1394                                         return 0;
1395                         };
1396                         break;
1397                 case Opt_fscache_uniq:
1398                         string = match_strdup(args);
1399                         if (string == NULL)
1400                                 goto out_nomem;
1401                         kfree(mnt->fscache_uniq);
1402                         mnt->fscache_uniq = string;
1403                         mnt->options |= NFS_OPTION_FSCACHE;
1404                         break;
1405
1406                 /*
1407                  * Special options
1408                  */
1409                 case Opt_sloppy:
1410                         sloppy = 1;
1411                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1412                         break;
1413                 case Opt_userspace:
1414                 case Opt_deprecated:
1415                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1416                                         "'%s'\n", p);
1417                         break;
1418
1419                 default:
1420                         invalid_option = 1;
1421                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1422                                         "'%s'\n", p);
1423                 }
1424         }
1425
1426         if (!sloppy && invalid_option)
1427                 return 0;
1428
1429         /*
1430          * verify that any proto=/mountproto= options match the address
1431          * familiies in the addr=/mountaddr= options.
1432          */
1433         if (protofamily != AF_UNSPEC &&
1434             protofamily != mnt->nfs_server.address.ss_family)
1435                 goto out_proto_mismatch;
1436
1437         if (mountfamily != AF_UNSPEC) {
1438                 if (mnt->mount_server.addrlen) {
1439                         if (mountfamily != mnt->mount_server.address.ss_family)
1440                                 goto out_mountproto_mismatch;
1441                 } else {
1442                         if (mountfamily != mnt->nfs_server.address.ss_family)
1443                                 goto out_mountproto_mismatch;
1444                 }
1445         }
1446
1447         return 1;
1448
1449 out_mountproto_mismatch:
1450         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1451                          "option\n");
1452         return 0;
1453 out_proto_mismatch:
1454         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1455         return 0;
1456 out_invalid_address:
1457         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1458         return 0;
1459 out_invalid_value:
1460         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1461         return 0;
1462 out_nomem:
1463         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1464         return 0;
1465 out_security_failure:
1466         free_secdata(secdata);
1467         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1468         return 0;
1469 }
1470
1471 /*
1472  * Match the requested auth flavors with the list returned by
1473  * the server.  Returns zero and sets the mount's authentication
1474  * flavor on success; returns -EACCES if server does not support
1475  * the requested flavor.
1476  */
1477 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1478                              struct nfs_mount_request *request)
1479 {
1480         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1481
1482         /*
1483          * Certain releases of Linux's mountd return an empty
1484          * flavor list.  To prevent behavioral regression with
1485          * these servers (ie. rejecting mounts that used to
1486          * succeed), revert to pre-2.6.32 behavior (no checking)
1487          * if the returned flavor list is empty.
1488          */
1489         if (server_authlist_len == 0)
1490                 return 0;
1491
1492         /*
1493          * We avoid sophisticated negotiating here, as there are
1494          * plenty of cases where we can get it wrong, providing
1495          * either too little or too much security.
1496          *
1497          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1498          * flavor listed first.  However, some servers list
1499          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1500          * preferred default, in args->auth_flavors[0] if user
1501          * didn't specify sec= mount option.
1502          */
1503         for (i = 0; i < args->auth_flavor_len; i++)
1504                 for (j = 0; j < server_authlist_len; j++)
1505                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1506                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1507                                         request->auth_flavs[j]);
1508                                 args->auth_flavors[0] = request->auth_flavs[j];
1509                                 return 0;
1510                         }
1511
1512         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1513         nfs_umount(request);
1514         return -EACCES;
1515 }
1516
1517 /*
1518  * Use the remote server's MOUNT service to request the NFS file handle
1519  * corresponding to the provided path.
1520  */
1521 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1522                          struct nfs_fh *root_fh)
1523 {
1524         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1525         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1526         struct nfs_mount_request request = {
1527                 .sap            = (struct sockaddr *)
1528                                                 &args->mount_server.address,
1529                 .dirpath        = args->nfs_server.export_path,
1530                 .protocol       = args->mount_server.protocol,
1531                 .fh             = root_fh,
1532                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1533                 .auth_flav_len  = &server_authlist_len,
1534                 .auth_flavs     = server_authlist,
1535         };
1536         int status;
1537
1538         if (args->mount_server.version == 0) {
1539                 switch (args->version) {
1540                         default:
1541                                 args->mount_server.version = NFS_MNT3_VERSION;
1542                                 break;
1543                         case 2:
1544                                 args->mount_server.version = NFS_MNT_VERSION;
1545                 }
1546         }
1547         request.version = args->mount_server.version;
1548
1549         if (args->mount_server.hostname)
1550                 request.hostname = args->mount_server.hostname;
1551         else
1552                 request.hostname = args->nfs_server.hostname;
1553
1554         /*
1555          * Construct the mount server's address.
1556          */
1557         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1558                 memcpy(request.sap, &args->nfs_server.address,
1559                        args->nfs_server.addrlen);
1560                 args->mount_server.addrlen = args->nfs_server.addrlen;
1561         }
1562         request.salen = args->mount_server.addrlen;
1563         nfs_set_port(request.sap, &args->mount_server.port, 0);
1564
1565         /*
1566          * Now ask the mount server to map our export path
1567          * to a file handle.
1568          */
1569         status = nfs_mount(&request);
1570         if (status != 0) {
1571                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1572                                 request.hostname, status);
1573                 return status;
1574         }
1575
1576         /*
1577          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1578          */
1579         if (args->mount_server.version != NFS_MNT3_VERSION)
1580                 return 0;
1581         return nfs_walk_authlist(args, &request);
1582 }
1583
1584 static int nfs_parse_simple_hostname(const char *dev_name,
1585                                      char **hostname, size_t maxnamlen,
1586                                      char **export_path, size_t maxpathlen)
1587 {
1588         size_t len;
1589         char *colon, *comma;
1590
1591         colon = strchr(dev_name, ':');
1592         if (colon == NULL)
1593                 goto out_bad_devname;
1594
1595         len = colon - dev_name;
1596         if (len > maxnamlen)
1597                 goto out_hostname;
1598
1599         /* N.B. caller will free nfs_server.hostname in all cases */
1600         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1601         if (!*hostname)
1602                 goto out_nomem;
1603
1604         /* kill possible hostname list: not supported */
1605         comma = strchr(*hostname, ',');
1606         if (comma != NULL) {
1607                 if (comma == *hostname)
1608                         goto out_bad_devname;
1609                 *comma = '\0';
1610         }
1611
1612         colon++;
1613         len = strlen(colon);
1614         if (len > maxpathlen)
1615                 goto out_path;
1616         *export_path = kstrndup(colon, len, GFP_KERNEL);
1617         if (!*export_path)
1618                 goto out_nomem;
1619
1620         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1621         return 0;
1622
1623 out_bad_devname:
1624         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1625         return -EINVAL;
1626
1627 out_nomem:
1628         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1629         return -ENOMEM;
1630
1631 out_hostname:
1632         dfprintk(MOUNT, "NFS: server hostname too long\n");
1633         return -ENAMETOOLONG;
1634
1635 out_path:
1636         dfprintk(MOUNT, "NFS: export pathname too long\n");
1637         return -ENAMETOOLONG;
1638 }
1639
1640 /*
1641  * Hostname has square brackets around it because it contains one or
1642  * more colons.  We look for the first closing square bracket, and a
1643  * colon must follow it.
1644  */
1645 static int nfs_parse_protected_hostname(const char *dev_name,
1646                                         char **hostname, size_t maxnamlen,
1647                                         char **export_path, size_t maxpathlen)
1648 {
1649         size_t len;
1650         char *start, *end;
1651
1652         start = (char *)(dev_name + 1);
1653
1654         end = strchr(start, ']');
1655         if (end == NULL)
1656                 goto out_bad_devname;
1657         if (*(end + 1) != ':')
1658                 goto out_bad_devname;
1659
1660         len = end - start;
1661         if (len > maxnamlen)
1662                 goto out_hostname;
1663
1664         /* N.B. caller will free nfs_server.hostname in all cases */
1665         *hostname = kstrndup(start, len, GFP_KERNEL);
1666         if (*hostname == NULL)
1667                 goto out_nomem;
1668
1669         end += 2;
1670         len = strlen(end);
1671         if (len > maxpathlen)
1672                 goto out_path;
1673         *export_path = kstrndup(end, len, GFP_KERNEL);
1674         if (!*export_path)
1675                 goto out_nomem;
1676
1677         return 0;
1678
1679 out_bad_devname:
1680         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1681         return -EINVAL;
1682
1683 out_nomem:
1684         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1685         return -ENOMEM;
1686
1687 out_hostname:
1688         dfprintk(MOUNT, "NFS: server hostname too long\n");
1689         return -ENAMETOOLONG;
1690
1691 out_path:
1692         dfprintk(MOUNT, "NFS: export pathname too long\n");
1693         return -ENAMETOOLONG;
1694 }
1695
1696 /*
1697  * Split "dev_name" into "hostname:export_path".
1698  *
1699  * The leftmost colon demarks the split between the server's hostname
1700  * and the export path.  If the hostname starts with a left square
1701  * bracket, then it may contain colons.
1702  *
1703  * Note: caller frees hostname and export path, even on error.
1704  */
1705 static int nfs_parse_devname(const char *dev_name,
1706                              char **hostname, size_t maxnamlen,
1707                              char **export_path, size_t maxpathlen)
1708 {
1709         if (*dev_name == '[')
1710                 return nfs_parse_protected_hostname(dev_name,
1711                                                     hostname, maxnamlen,
1712                                                     export_path, maxpathlen);
1713
1714         return nfs_parse_simple_hostname(dev_name,
1715                                          hostname, maxnamlen,
1716                                          export_path, maxpathlen);
1717 }
1718
1719 /*
1720  * Validate the NFS2/NFS3 mount data
1721  * - fills in the mount root filehandle
1722  *
1723  * For option strings, user space handles the following behaviors:
1724  *
1725  * + DNS: mapping server host name to IP address ("addr=" option)
1726  *
1727  * + failure mode: how to behave if a mount request can't be handled
1728  *   immediately ("fg/bg" option)
1729  *
1730  * + retry: how often to retry a mount request ("retry=" option)
1731  *
1732  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1733  *   mountproto=tcp after mountproto=udp, and so on
1734  */
1735 static int nfs_validate_mount_data(void *options,
1736                                    struct nfs_parsed_mount_data *args,
1737                                    struct nfs_fh *mntfh,
1738                                    const char *dev_name)
1739 {
1740         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1741         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1742
1743         if (data == NULL)
1744                 goto out_no_data;
1745
1746         switch (data->version) {
1747         case 1:
1748                 data->namlen = 0;
1749         case 2:
1750                 data->bsize = 0;
1751         case 3:
1752                 if (data->flags & NFS_MOUNT_VER3)
1753                         goto out_no_v3;
1754                 data->root.size = NFS2_FHSIZE;
1755                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1756         case 4:
1757                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1758                         goto out_no_sec;
1759         case 5:
1760                 memset(data->context, 0, sizeof(data->context));
1761         case 6:
1762                 if (data->flags & NFS_MOUNT_VER3) {
1763                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1764                                 goto out_invalid_fh;
1765                         mntfh->size = data->root.size;
1766                         args->version = 3;
1767                 } else {
1768                         mntfh->size = NFS2_FHSIZE;
1769                         args->version = 2;
1770                 }
1771
1772
1773                 memcpy(mntfh->data, data->root.data, mntfh->size);
1774                 if (mntfh->size < sizeof(mntfh->data))
1775                         memset(mntfh->data + mntfh->size, 0,
1776                                sizeof(mntfh->data) - mntfh->size);
1777
1778                 /*
1779                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1780                  * can deal with.
1781                  */
1782                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1783                 args->rsize             = data->rsize;
1784                 args->wsize             = data->wsize;
1785                 args->timeo             = data->timeo;
1786                 args->retrans           = data->retrans;
1787                 args->acregmin          = data->acregmin;
1788                 args->acregmax          = data->acregmax;
1789                 args->acdirmin          = data->acdirmin;
1790                 args->acdirmax          = data->acdirmax;
1791
1792                 memcpy(sap, &data->addr, sizeof(data->addr));
1793                 args->nfs_server.addrlen = sizeof(data->addr);
1794                 if (!nfs_verify_server_address(sap))
1795                         goto out_no_address;
1796
1797                 if (!(data->flags & NFS_MOUNT_TCP))
1798                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1799                 /* N.B. caller will free nfs_server.hostname in all cases */
1800                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1801                 args->namlen            = data->namlen;
1802                 args->bsize             = data->bsize;
1803
1804                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1805                         args->auth_flavors[0] = data->pseudoflavor;
1806                 if (!args->nfs_server.hostname)
1807                         goto out_nomem;
1808
1809                 /*
1810                  * The legacy version 6 binary mount data from userspace has a
1811                  * field used only to transport selinux information into the
1812                  * the kernel.  To continue to support that functionality we
1813                  * have a touch of selinux knowledge here in the NFS code. The
1814                  * userspace code converted context=blah to just blah so we are
1815                  * converting back to the full string selinux understands.
1816                  */
1817                 if (data->context[0]){
1818 #ifdef CONFIG_SECURITY_SELINUX
1819                         int rc;
1820                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1821                         if (!opts_str)
1822                                 return -ENOMEM;
1823                         strcpy(opts_str, "context=");
1824                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1825                         strcat(opts_str, &data->context[0]);
1826                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1827                         kfree(opts_str);
1828                         if (rc)
1829                                 return rc;
1830 #else
1831                         return -EINVAL;
1832 #endif
1833                 }
1834
1835                 break;
1836         default: {
1837                 int status;
1838
1839                 if (nfs_parse_mount_options((char *)options, args) == 0)
1840                         return -EINVAL;
1841
1842                 if (!nfs_verify_server_address(sap))
1843                         goto out_no_address;
1844
1845                 if (args->version == 4)
1846 #ifdef CONFIG_NFS_V4
1847                         return nfs4_validate_text_mount_data(options,
1848                                                              args, dev_name);
1849 #else
1850                         goto out_v4_not_compiled;
1851 #endif
1852
1853                 nfs_set_port(sap, &args->nfs_server.port, 0);
1854
1855                 nfs_set_mount_transport_protocol(args);
1856
1857                 status = nfs_parse_devname(dev_name,
1858                                            &args->nfs_server.hostname,
1859                                            PAGE_SIZE,
1860                                            &args->nfs_server.export_path,
1861                                            NFS_MAXPATHLEN);
1862                 if (!status)
1863                         status = nfs_try_mount(args, mntfh);
1864
1865                 kfree(args->nfs_server.export_path);
1866                 args->nfs_server.export_path = NULL;
1867
1868                 if (status)
1869                         return status;
1870
1871                 break;
1872                 }
1873         }
1874
1875 #ifndef CONFIG_NFS_V3
1876         if (args->version == 3)
1877                 goto out_v3_not_compiled;
1878 #endif /* !CONFIG_NFS_V3 */
1879
1880         return 0;
1881
1882 out_no_data:
1883         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1884         return -EINVAL;
1885
1886 out_no_v3:
1887         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1888                  data->version);
1889         return -EINVAL;
1890
1891 out_no_sec:
1892         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1893         return -EINVAL;
1894
1895 #ifndef CONFIG_NFS_V3
1896 out_v3_not_compiled:
1897         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1898         return -EPROTONOSUPPORT;
1899 #endif /* !CONFIG_NFS_V3 */
1900
1901 #ifndef CONFIG_NFS_V4
1902 out_v4_not_compiled:
1903         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1904         return -EPROTONOSUPPORT;
1905 #endif /* !CONFIG_NFS_V4 */
1906
1907 out_nomem:
1908         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1909         return -ENOMEM;
1910
1911 out_no_address:
1912         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1913         return -EINVAL;
1914
1915 out_invalid_fh:
1916         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1917         return -EINVAL;
1918 }
1919
1920 static int
1921 nfs_compare_remount_data(struct nfs_server *nfss,
1922                          struct nfs_parsed_mount_data *data)
1923 {
1924         if (data->flags != nfss->flags ||
1925             data->rsize != nfss->rsize ||
1926             data->wsize != nfss->wsize ||
1927             data->retrans != nfss->client->cl_timeout->to_retries ||
1928             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1929             data->acregmin != nfss->acregmin / HZ ||
1930             data->acregmax != nfss->acregmax / HZ ||
1931             data->acdirmin != nfss->acdirmin / HZ ||
1932             data->acdirmax != nfss->acdirmax / HZ ||
1933             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1934             data->nfs_server.port != nfss->port ||
1935             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1936             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1937                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
1938                 return -EINVAL;
1939
1940         return 0;
1941 }
1942
1943 static int
1944 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1945 {
1946         int error;
1947         struct nfs_server *nfss = sb->s_fs_info;
1948         struct nfs_parsed_mount_data *data;
1949         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1950         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1951         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1952
1953         /*
1954          * Userspace mount programs that send binary options generally send
1955          * them populated with default values. We have no way to know which
1956          * ones were explicitly specified. Fall back to legacy behavior and
1957          * just return success.
1958          */
1959         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1960             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1961                                            options->version <= 6))))
1962                 return 0;
1963
1964         data = kzalloc(sizeof(*data), GFP_KERNEL);
1965         if (data == NULL)
1966                 return -ENOMEM;
1967
1968         /* fill out struct with values from existing mount */
1969         data->flags = nfss->flags;
1970         data->rsize = nfss->rsize;
1971         data->wsize = nfss->wsize;
1972         data->retrans = nfss->client->cl_timeout->to_retries;
1973         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1974         data->acregmin = nfss->acregmin / HZ;
1975         data->acregmax = nfss->acregmax / HZ;
1976         data->acdirmin = nfss->acdirmin / HZ;
1977         data->acdirmax = nfss->acdirmax / HZ;
1978         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1979         data->nfs_server.port = nfss->port;
1980         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1981         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1982                 data->nfs_server.addrlen);
1983
1984         /* overwrite those values with any that were specified */
1985         error = nfs_parse_mount_options((char *)options, data);
1986         if (error < 0)
1987                 goto out;
1988
1989         /* compare new mount options with old ones */
1990         error = nfs_compare_remount_data(nfss, data);
1991 out:
1992         kfree(data);
1993         return error;
1994 }
1995
1996 /*
1997  * Initialise the common bits of the superblock
1998  */
1999 static inline void nfs_initialise_sb(struct super_block *sb)
2000 {
2001         struct nfs_server *server = NFS_SB(sb);
2002
2003         sb->s_magic = NFS_SUPER_MAGIC;
2004
2005         /* We probably want something more informative here */
2006         snprintf(sb->s_id, sizeof(sb->s_id),
2007                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2008
2009         if (sb->s_blocksize == 0)
2010                 sb->s_blocksize = nfs_block_bits(server->wsize,
2011                                                  &sb->s_blocksize_bits);
2012
2013         if (server->flags & NFS_MOUNT_NOAC)
2014                 sb->s_flags |= MS_SYNCHRONOUS;
2015
2016         sb->s_bdi = &server->backing_dev_info;
2017
2018         nfs_super_set_maxbytes(sb, server->maxfilesize);
2019 }
2020
2021 /*
2022  * Finish setting up an NFS2/3 superblock
2023  */
2024 static void nfs_fill_super(struct super_block *sb,
2025                            struct nfs_parsed_mount_data *data)
2026 {
2027         struct nfs_server *server = NFS_SB(sb);
2028
2029         sb->s_blocksize_bits = 0;
2030         sb->s_blocksize = 0;
2031         if (data->bsize)
2032                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2033
2034         if (server->nfs_client->rpc_ops->version == 3) {
2035                 /* The VFS shouldn't apply the umask to mode bits. We will do
2036                  * so ourselves when necessary.
2037                  */
2038                 sb->s_flags |= MS_POSIXACL;
2039                 sb->s_time_gran = 1;
2040         }
2041
2042         sb->s_op = &nfs_sops;
2043         nfs_initialise_sb(sb);
2044 }
2045
2046 /*
2047  * Finish setting up a cloned NFS2/3 superblock
2048  */
2049 static void nfs_clone_super(struct super_block *sb,
2050                             const struct super_block *old_sb)
2051 {
2052         struct nfs_server *server = NFS_SB(sb);
2053
2054         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2055         sb->s_blocksize = old_sb->s_blocksize;
2056         sb->s_maxbytes = old_sb->s_maxbytes;
2057
2058         if (server->nfs_client->rpc_ops->version == 3) {
2059                 /* The VFS shouldn't apply the umask to mode bits. We will do
2060                  * so ourselves when necessary.
2061                  */
2062                 sb->s_flags |= MS_POSIXACL;
2063                 sb->s_time_gran = 1;
2064         }
2065
2066         sb->s_op = old_sb->s_op;
2067         nfs_initialise_sb(sb);
2068 }
2069
2070 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2071 {
2072         const struct nfs_server *a = s->s_fs_info;
2073         const struct rpc_clnt *clnt_a = a->client;
2074         const struct rpc_clnt *clnt_b = b->client;
2075
2076         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2077                 goto Ebusy;
2078         if (a->nfs_client != b->nfs_client)
2079                 goto Ebusy;
2080         if (a->flags != b->flags)
2081                 goto Ebusy;
2082         if (a->wsize != b->wsize)
2083                 goto Ebusy;
2084         if (a->rsize != b->rsize)
2085                 goto Ebusy;
2086         if (a->acregmin != b->acregmin)
2087                 goto Ebusy;
2088         if (a->acregmax != b->acregmax)
2089                 goto Ebusy;
2090         if (a->acdirmin != b->acdirmin)
2091                 goto Ebusy;
2092         if (a->acdirmax != b->acdirmax)
2093                 goto Ebusy;
2094         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2095                 goto Ebusy;
2096         return 1;
2097 Ebusy:
2098         return 0;
2099 }
2100
2101 struct nfs_sb_mountdata {
2102         struct nfs_server *server;
2103         int mntflags;
2104 };
2105
2106 static int nfs_set_super(struct super_block *s, void *data)
2107 {
2108         struct nfs_sb_mountdata *sb_mntdata = data;
2109         struct nfs_server *server = sb_mntdata->server;
2110         int ret;
2111
2112         s->s_flags = sb_mntdata->mntflags;
2113         s->s_fs_info = server;
2114         ret = set_anon_super(s, server);
2115         if (ret == 0)
2116                 server->s_dev = s->s_dev;
2117         return ret;
2118 }
2119
2120 static int nfs_compare_super_address(struct nfs_server *server1,
2121                                      struct nfs_server *server2)
2122 {
2123         struct sockaddr *sap1, *sap2;
2124
2125         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2126         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2127
2128         if (sap1->sa_family != sap2->sa_family)
2129                 return 0;
2130
2131         switch (sap1->sa_family) {
2132         case AF_INET: {
2133                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2134                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2135                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2136                         return 0;
2137                 if (sin1->sin_port != sin2->sin_port)
2138                         return 0;
2139                 break;
2140         }
2141         case AF_INET6: {
2142                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2143                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2144                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2145                         return 0;
2146                 if (sin1->sin6_port != sin2->sin6_port)
2147                         return 0;
2148                 break;
2149         }
2150         default:
2151                 return 0;
2152         }
2153
2154         return 1;
2155 }
2156
2157 static int nfs_compare_super(struct super_block *sb, void *data)
2158 {
2159         struct nfs_sb_mountdata *sb_mntdata = data;
2160         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2161         int mntflags = sb_mntdata->mntflags;
2162
2163         if (!nfs_compare_super_address(old, server))
2164                 return 0;
2165         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2166         if (old->flags & NFS_MOUNT_UNSHARED)
2167                 return 0;
2168         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2169                 return 0;
2170         return nfs_compare_mount_options(sb, server, mntflags);
2171 }
2172
2173 static int nfs_bdi_register(struct nfs_server *server)
2174 {
2175         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2176 }
2177
2178 static int nfs_get_sb(struct file_system_type *fs_type,
2179         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2180 {
2181         struct nfs_server *server = NULL;
2182         struct super_block *s;
2183         struct nfs_parsed_mount_data *data;
2184         struct nfs_fh *mntfh;
2185         struct dentry *mntroot;
2186         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2187         struct nfs_sb_mountdata sb_mntdata = {
2188                 .mntflags = flags,
2189         };
2190         int error = -ENOMEM;
2191
2192         data = nfs_alloc_parsed_mount_data(3);
2193         mntfh = nfs_alloc_fhandle();
2194         if (data == NULL || mntfh == NULL)
2195                 goto out_free_fh;
2196
2197         security_init_mnt_opts(&data->lsm_opts);
2198
2199         /* Validate the mount data */
2200         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2201         if (error < 0)
2202                 goto out;
2203
2204 #ifdef CONFIG_NFS_V4
2205         if (data->version == 4) {
2206                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2207                 kfree(data->client_address);
2208                 kfree(data->nfs_server.export_path);
2209                 goto out;
2210         }
2211 #endif  /* CONFIG_NFS_V4 */
2212
2213         /* Get a volume representation */
2214         server = nfs_create_server(data, mntfh);
2215         if (IS_ERR(server)) {
2216                 error = PTR_ERR(server);
2217                 goto out;
2218         }
2219         sb_mntdata.server = server;
2220
2221         if (server->flags & NFS_MOUNT_UNSHARED)
2222                 compare_super = NULL;
2223
2224         /* Get a superblock - note that we may end up sharing one that already exists */
2225         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2226         if (IS_ERR(s)) {
2227                 error = PTR_ERR(s);
2228                 goto out_err_nosb;
2229         }
2230
2231         if (s->s_fs_info != server) {
2232                 nfs_free_server(server);
2233                 server = NULL;
2234         } else {
2235                 error = nfs_bdi_register(server);
2236                 if (error)
2237                         goto error_splat_bdi;
2238         }
2239
2240         if (!s->s_root) {
2241                 /* initial superblock/root creation */
2242                 nfs_fill_super(s, data);
2243                 nfs_fscache_get_super_cookie(
2244                         s, data ? data->fscache_uniq : NULL, NULL);
2245         }
2246
2247         mntroot = nfs_get_root(s, mntfh);
2248         if (IS_ERR(mntroot)) {
2249                 error = PTR_ERR(mntroot);
2250                 goto error_splat_super;
2251         }
2252
2253         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2254         if (error)
2255                 goto error_splat_root;
2256
2257         s->s_flags |= MS_ACTIVE;
2258         mnt->mnt_sb = s;
2259         mnt->mnt_root = mntroot;
2260         error = 0;
2261
2262 out:
2263         kfree(data->nfs_server.hostname);
2264         kfree(data->mount_server.hostname);
2265         kfree(data->fscache_uniq);
2266         security_free_mnt_opts(&data->lsm_opts);
2267 out_free_fh:
2268         nfs_free_fhandle(mntfh);
2269         kfree(data);
2270         return error;
2271
2272 out_err_nosb:
2273         nfs_free_server(server);
2274         goto out;
2275
2276 error_splat_root:
2277         dput(mntroot);
2278 error_splat_super:
2279         if (server && !s->s_root)
2280                 bdi_unregister(&server->backing_dev_info);
2281 error_splat_bdi:
2282         deactivate_locked_super(s);
2283         goto out;
2284 }
2285
2286 /*
2287  * Ensure that we unregister the bdi before kill_anon_super
2288  * releases the device name
2289  */
2290 static void nfs_put_super(struct super_block *s)
2291 {
2292         struct nfs_server *server = NFS_SB(s);
2293
2294         bdi_unregister(&server->backing_dev_info);
2295 }
2296
2297 /*
2298  * Destroy an NFS2/3 superblock
2299  */
2300 static void nfs_kill_super(struct super_block *s)
2301 {
2302         struct nfs_server *server = NFS_SB(s);
2303
2304         kill_anon_super(s);
2305         nfs_fscache_release_super_cookie(s);
2306         nfs_free_server(server);
2307 }
2308
2309 /*
2310  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2311  */
2312 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2313                            const char *dev_name, void *raw_data,
2314                            struct vfsmount *mnt)
2315 {
2316         struct nfs_clone_mount *data = raw_data;
2317         struct super_block *s;
2318         struct nfs_server *server;
2319         struct dentry *mntroot;
2320         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2321         struct nfs_sb_mountdata sb_mntdata = {
2322                 .mntflags = flags,
2323         };
2324         int error;
2325
2326         dprintk("--> nfs_xdev_get_sb()\n");
2327
2328         /* create a new volume representation */
2329         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2330         if (IS_ERR(server)) {
2331                 error = PTR_ERR(server);
2332                 goto out_err_noserver;
2333         }
2334         sb_mntdata.server = server;
2335
2336         if (server->flags & NFS_MOUNT_UNSHARED)
2337                 compare_super = NULL;
2338
2339         /* Get a superblock - note that we may end up sharing one that already exists */
2340         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2341         if (IS_ERR(s)) {
2342                 error = PTR_ERR(s);
2343                 goto out_err_nosb;
2344         }
2345
2346         if (s->s_fs_info != server) {
2347                 nfs_free_server(server);
2348                 server = NULL;
2349         } else {
2350                 error = nfs_bdi_register(server);
2351                 if (error)
2352                         goto error_splat_bdi;
2353         }
2354
2355         if (!s->s_root) {
2356                 /* initial superblock/root creation */
2357                 nfs_clone_super(s, data->sb);
2358                 nfs_fscache_get_super_cookie(s, NULL, data);
2359         }
2360
2361         mntroot = nfs_get_root(s, data->fh);
2362         if (IS_ERR(mntroot)) {
2363                 error = PTR_ERR(mntroot);
2364                 goto error_splat_super;
2365         }
2366         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2367                 dput(mntroot);
2368                 error = -ESTALE;
2369                 goto error_splat_super;
2370         }
2371
2372         s->s_flags |= MS_ACTIVE;
2373         mnt->mnt_sb = s;
2374         mnt->mnt_root = mntroot;
2375
2376         /* clone any lsm security options from the parent to the new sb */
2377         security_sb_clone_mnt_opts(data->sb, s);
2378
2379         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2380         return 0;
2381
2382 out_err_nosb:
2383         nfs_free_server(server);
2384 out_err_noserver:
2385         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2386         return error;
2387
2388 error_splat_super:
2389         if (server && !s->s_root)
2390                 bdi_unregister(&server->backing_dev_info);
2391 error_splat_bdi:
2392         deactivate_locked_super(s);
2393         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2394         return error;
2395 }
2396
2397 #ifdef CONFIG_NFS_V4
2398
2399 /*
2400  * Finish setting up a cloned NFS4 superblock
2401  */
2402 static void nfs4_clone_super(struct super_block *sb,
2403                             const struct super_block *old_sb)
2404 {
2405         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2406         sb->s_blocksize = old_sb->s_blocksize;
2407         sb->s_maxbytes = old_sb->s_maxbytes;
2408         sb->s_time_gran = 1;
2409         sb->s_op = old_sb->s_op;
2410         nfs_initialise_sb(sb);
2411 }
2412
2413 /*
2414  * Set up an NFS4 superblock
2415  */
2416 static void nfs4_fill_super(struct super_block *sb)
2417 {
2418         sb->s_time_gran = 1;
2419         sb->s_op = &nfs4_sops;
2420         nfs_initialise_sb(sb);
2421 }
2422
2423 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2424 {
2425         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2426 }
2427
2428 static int nfs4_validate_text_mount_data(void *options,
2429                                          struct nfs_parsed_mount_data *args,
2430                                          const char *dev_name)
2431 {
2432         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2433
2434         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2435
2436         nfs_validate_transport_protocol(args);
2437
2438         nfs4_validate_mount_flags(args);
2439
2440         if (args->version != 4) {
2441                 dfprintk(MOUNT,
2442                          "NFS4: Illegal mount version\n");
2443                 return -EINVAL;
2444         }
2445
2446         if (args->auth_flavor_len > 1) {
2447                 dfprintk(MOUNT,
2448                          "NFS4: Too many RPC auth flavours specified\n");
2449                 return -EINVAL;
2450         }
2451
2452         if (args->client_address == NULL) {
2453                 dfprintk(MOUNT,
2454                          "NFS4: mount program didn't pass callback address\n");
2455                 return -EINVAL;
2456         }
2457
2458         return nfs_parse_devname(dev_name,
2459                                    &args->nfs_server.hostname,
2460                                    NFS4_MAXNAMLEN,
2461                                    &args->nfs_server.export_path,
2462                                    NFS4_MAXPATHLEN);
2463 }
2464
2465 /*
2466  * Validate NFSv4 mount options
2467  */
2468 static int nfs4_validate_mount_data(void *options,
2469                                     struct nfs_parsed_mount_data *args,
2470                                     const char *dev_name)
2471 {
2472         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2473         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2474         char *c;
2475
2476         if (data == NULL)
2477                 goto out_no_data;
2478
2479         switch (data->version) {
2480         case 1:
2481                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2482                         goto out_no_address;
2483                 if (data->host_addrlen == 0)
2484                         goto out_no_address;
2485                 args->nfs_server.addrlen = data->host_addrlen;
2486                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2487                         return -EFAULT;
2488                 if (!nfs_verify_server_address(sap))
2489                         goto out_no_address;
2490
2491                 if (data->auth_flavourlen) {
2492                         if (data->auth_flavourlen > 1)
2493                                 goto out_inval_auth;
2494                         if (copy_from_user(&args->auth_flavors[0],
2495                                            data->auth_flavours,
2496                                            sizeof(args->auth_flavors[0])))
2497                                 return -EFAULT;
2498                 }
2499
2500                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2501                 if (IS_ERR(c))
2502                         return PTR_ERR(c);
2503                 args->nfs_server.hostname = c;
2504
2505                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2506                 if (IS_ERR(c))
2507                         return PTR_ERR(c);
2508                 args->nfs_server.export_path = c;
2509                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2510
2511                 c = strndup_user(data->client_addr.data, 16);
2512                 if (IS_ERR(c))
2513                         return PTR_ERR(c);
2514                 args->client_address = c;
2515
2516                 /*
2517                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2518                  * can deal with.
2519                  */
2520
2521                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2522                 args->rsize     = data->rsize;
2523                 args->wsize     = data->wsize;
2524                 args->timeo     = data->timeo;
2525                 args->retrans   = data->retrans;
2526                 args->acregmin  = data->acregmin;
2527                 args->acregmax  = data->acregmax;
2528                 args->acdirmin  = data->acdirmin;
2529                 args->acdirmax  = data->acdirmax;
2530                 args->nfs_server.protocol = data->proto;
2531                 nfs_validate_transport_protocol(args);
2532
2533                 break;
2534         default:
2535                 if (nfs_parse_mount_options((char *)options, args) == 0)
2536                         return -EINVAL;
2537
2538                 if (!nfs_verify_server_address(sap))
2539                         return -EINVAL;
2540
2541                 return nfs4_validate_text_mount_data(options, args, dev_name);
2542         }
2543
2544         return 0;
2545
2546 out_no_data:
2547         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2548         return -EINVAL;
2549
2550 out_inval_auth:
2551         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2552                  data->auth_flavourlen);
2553         return -EINVAL;
2554
2555 out_no_address:
2556         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2557         return -EINVAL;
2558 }
2559
2560 /*
2561  * Get the superblock for the NFS4 root partition
2562  */
2563 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2564         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2565 {
2566         struct nfs_parsed_mount_data *data = raw_data;
2567         struct super_block *s;
2568         struct nfs_server *server;
2569         struct nfs_fh *mntfh;
2570         struct dentry *mntroot;
2571         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2572         struct nfs_sb_mountdata sb_mntdata = {
2573                 .mntflags = flags,
2574         };
2575         int error = -ENOMEM;
2576
2577         mntfh = nfs_alloc_fhandle();
2578         if (data == NULL || mntfh == NULL)
2579                 goto out_free_fh;
2580
2581         security_init_mnt_opts(&data->lsm_opts);
2582
2583         /* Get a volume representation */
2584         server = nfs4_create_server(data, mntfh);
2585         if (IS_ERR(server)) {
2586                 error = PTR_ERR(server);
2587                 goto out;
2588         }
2589         sb_mntdata.server = server;
2590
2591         if (server->flags & NFS4_MOUNT_UNSHARED)
2592                 compare_super = NULL;
2593
2594         /* Get a superblock - note that we may end up sharing one that already exists */
2595         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2596         if (IS_ERR(s)) {
2597                 error = PTR_ERR(s);
2598                 goto out_free;
2599         }
2600
2601         if (s->s_fs_info != server) {
2602                 nfs_free_server(server);
2603                 server = NULL;
2604         } else {
2605                 error = nfs_bdi_register(server);
2606                 if (error)
2607                         goto error_splat_bdi;
2608         }
2609
2610         if (!s->s_root) {
2611                 /* initial superblock/root creation */
2612                 nfs4_fill_super(s);
2613                 nfs_fscache_get_super_cookie(
2614                         s, data ? data->fscache_uniq : NULL, NULL);
2615         }
2616
2617         mntroot = nfs4_get_root(s, mntfh);
2618         if (IS_ERR(mntroot)) {
2619                 error = PTR_ERR(mntroot);
2620                 goto error_splat_super;
2621         }
2622
2623         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2624         if (error)
2625                 goto error_splat_root;
2626
2627         s->s_flags |= MS_ACTIVE;
2628         mnt->mnt_sb = s;
2629         mnt->mnt_root = mntroot;
2630         error = 0;
2631
2632 out:
2633         security_free_mnt_opts(&data->lsm_opts);
2634 out_free_fh:
2635         nfs_free_fhandle(mntfh);
2636         return error;
2637
2638 out_free:
2639         nfs_free_server(server);
2640         goto out;
2641
2642 error_splat_root:
2643         dput(mntroot);
2644 error_splat_super:
2645         if (server && !s->s_root)
2646                 bdi_unregister(&server->backing_dev_info);
2647 error_splat_bdi:
2648         deactivate_locked_super(s);
2649         goto out;
2650 }
2651
2652 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2653                 int flags, void *data, const char *hostname)
2654 {
2655         struct vfsmount *root_mnt;
2656         char *root_devname;
2657         size_t len;
2658
2659         len = strlen(hostname) + 3;
2660         root_devname = kmalloc(len, GFP_KERNEL);
2661         if (root_devname == NULL)
2662                 return ERR_PTR(-ENOMEM);
2663         snprintf(root_devname, len, "%s:/", hostname);
2664         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2665         kfree(root_devname);
2666         return root_mnt;
2667 }
2668
2669 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2670 {
2671         char *page = (char *) __get_free_page(GFP_KERNEL);
2672         char *devname, *tmp;
2673
2674         if (page == NULL)
2675                 return;
2676         devname = nfs_path(path->mnt->mnt_devname,
2677                         path->mnt->mnt_root, path->dentry,
2678                         page, PAGE_SIZE);
2679         if (IS_ERR(devname))
2680                 goto out_freepage;
2681         tmp = kstrdup(devname, GFP_KERNEL);
2682         if (tmp == NULL)
2683                 goto out_freepage;
2684         kfree(mnt->mnt_devname);
2685         mnt->mnt_devname = tmp;
2686 out_freepage:
2687         free_page((unsigned long)page);
2688 }
2689
2690 struct nfs_referral_count {
2691         struct list_head list;
2692         const struct task_struct *task;
2693         unsigned int referral_count;
2694 };
2695
2696 static LIST_HEAD(nfs_referral_count_list);
2697 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2698
2699 static struct nfs_referral_count *nfs_find_referral_count(void)
2700 {
2701         struct nfs_referral_count *p;
2702
2703         list_for_each_entry(p, &nfs_referral_count_list, list) {
2704                 if (p->task == current)
2705                         return p;
2706         }
2707         return NULL;
2708 }
2709
2710 #define NFS_MAX_NESTED_REFERRALS 2
2711
2712 static int nfs_referral_loop_protect(void)
2713 {
2714         struct nfs_referral_count *p, *new;
2715         int ret = -ENOMEM;
2716
2717         new = kmalloc(sizeof(*new), GFP_KERNEL);
2718         if (!new)
2719                 goto out;
2720         new->task = current;
2721         new->referral_count = 1;
2722
2723         ret = 0;
2724         spin_lock(&nfs_referral_count_list_lock);
2725         p = nfs_find_referral_count();
2726         if (p != NULL) {
2727                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2728                         ret = -ELOOP;
2729                 else
2730                         p->referral_count++;
2731         } else {
2732                 list_add(&new->list, &nfs_referral_count_list);
2733                 new = NULL;
2734         }
2735         spin_unlock(&nfs_referral_count_list_lock);
2736         kfree(new);
2737 out:
2738         return ret;
2739 }
2740
2741 static void nfs_referral_loop_unprotect(void)
2742 {
2743         struct nfs_referral_count *p;
2744
2745         spin_lock(&nfs_referral_count_list_lock);
2746         p = nfs_find_referral_count();
2747         p->referral_count--;
2748         if (p->referral_count == 0)
2749                 list_del(&p->list);
2750         else
2751                 p = NULL;
2752         spin_unlock(&nfs_referral_count_list_lock);
2753         kfree(p);
2754 }
2755
2756 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2757                 const char *export_path, struct vfsmount *mnt_target)
2758 {
2759         struct nameidata *nd = NULL;
2760         struct mnt_namespace *ns_private;
2761         struct super_block *s;
2762         int ret;
2763
2764         nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2765         if (nd == NULL)
2766                 return -ENOMEM;
2767
2768         ns_private = create_mnt_ns(root_mnt);
2769         ret = PTR_ERR(ns_private);
2770         if (IS_ERR(ns_private))
2771                 goto out_mntput;
2772
2773         ret = nfs_referral_loop_protect();
2774         if (ret != 0)
2775                 goto out_put_mnt_ns;
2776
2777         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2778                         export_path, LOOKUP_FOLLOW, nd);
2779
2780         nfs_referral_loop_unprotect();
2781         put_mnt_ns(ns_private);
2782
2783         if (ret != 0)
2784                 goto out_err;
2785
2786         s = nd->path.mnt->mnt_sb;
2787         atomic_inc(&s->s_active);
2788         mnt_target->mnt_sb = s;
2789         mnt_target->mnt_root = dget(nd->path.dentry);
2790
2791         /* Correct the device pathname */
2792         nfs_fix_devname(&nd->path, mnt_target);
2793
2794         path_put(&nd->path);
2795         kfree(nd);
2796         down_write(&s->s_umount);
2797         return 0;
2798 out_put_mnt_ns:
2799         put_mnt_ns(ns_private);
2800 out_mntput:
2801         mntput(root_mnt);
2802 out_err:
2803         kfree(nd);
2804         return ret;
2805 }
2806
2807 static int nfs4_try_mount(int flags, const char *dev_name,
2808                          struct nfs_parsed_mount_data *data,
2809                          struct vfsmount *mnt)
2810 {
2811         char *export_path;
2812         struct vfsmount *root_mnt;
2813         int error;
2814
2815         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2816
2817         export_path = data->nfs_server.export_path;
2818         data->nfs_server.export_path = "/";
2819         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2820                         data->nfs_server.hostname);
2821         data->nfs_server.export_path = export_path;
2822
2823         error = PTR_ERR(root_mnt);
2824         if (IS_ERR(root_mnt))
2825                 goto out;
2826
2827         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2828
2829 out:
2830         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2831                         error != 0 ? " [error]" : "");
2832         return error;
2833 }
2834
2835 /*
2836  * Get the superblock for an NFS4 mountpoint
2837  */
2838 static int nfs4_get_sb(struct file_system_type *fs_type,
2839         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2840 {
2841         struct nfs_parsed_mount_data *data;
2842         int error = -ENOMEM;
2843
2844         data = nfs_alloc_parsed_mount_data(4);
2845         if (data == NULL)
2846                 goto out_free_data;
2847
2848         /* Validate the mount data */
2849         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2850         if (error < 0)
2851                 goto out;
2852
2853         error = nfs4_try_mount(flags, dev_name, data, mnt);
2854
2855 out:
2856         kfree(data->client_address);
2857         kfree(data->nfs_server.export_path);
2858         kfree(data->nfs_server.hostname);
2859         kfree(data->fscache_uniq);
2860 out_free_data:
2861         kfree(data);
2862         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2863                         error != 0 ? " [error]" : "");
2864         return error;
2865 }
2866
2867 static void nfs4_kill_super(struct super_block *sb)
2868 {
2869         struct nfs_server *server = NFS_SB(sb);
2870
2871         dprintk("--> %s\n", __func__);
2872         nfs_super_return_all_delegations(sb);
2873         kill_anon_super(sb);
2874         nfs_fscache_release_super_cookie(sb);
2875         nfs_free_server(server);
2876         dprintk("<-- %s\n", __func__);
2877 }
2878
2879 /*
2880  * Clone an NFS4 server record on xdev traversal (FSID-change)
2881  */
2882 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2883                             const char *dev_name, void *raw_data,
2884                             struct vfsmount *mnt)
2885 {
2886         struct nfs_clone_mount *data = raw_data;
2887         struct super_block *s;
2888         struct nfs_server *server;
2889         struct dentry *mntroot;
2890         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2891         struct nfs_sb_mountdata sb_mntdata = {
2892                 .mntflags = flags,
2893         };
2894         int error;
2895
2896         dprintk("--> nfs4_xdev_get_sb()\n");
2897
2898         /* create a new volume representation */
2899         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2900         if (IS_ERR(server)) {
2901                 error = PTR_ERR(server);
2902                 goto out_err_noserver;
2903         }
2904         sb_mntdata.server = server;
2905
2906         if (server->flags & NFS4_MOUNT_UNSHARED)
2907                 compare_super = NULL;
2908
2909         /* Get a superblock - note that we may end up sharing one that already exists */
2910         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2911         if (IS_ERR(s)) {
2912                 error = PTR_ERR(s);
2913                 goto out_err_nosb;
2914         }
2915
2916         if (s->s_fs_info != server) {
2917                 nfs_free_server(server);
2918                 server = NULL;
2919         } else {
2920                 error = nfs_bdi_register(server);
2921                 if (error)
2922                         goto error_splat_bdi;
2923         }
2924
2925         if (!s->s_root) {
2926                 /* initial superblock/root creation */
2927                 nfs4_clone_super(s, data->sb);
2928                 nfs_fscache_get_super_cookie(s, NULL, data);
2929         }
2930
2931         mntroot = nfs4_get_root(s, data->fh);
2932         if (IS_ERR(mntroot)) {
2933                 error = PTR_ERR(mntroot);
2934                 goto error_splat_super;
2935         }
2936         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2937                 dput(mntroot);
2938                 error = -ESTALE;
2939                 goto error_splat_super;
2940         }
2941
2942         s->s_flags |= MS_ACTIVE;
2943         mnt->mnt_sb = s;
2944         mnt->mnt_root = mntroot;
2945
2946         security_sb_clone_mnt_opts(data->sb, s);
2947
2948         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2949         return 0;
2950
2951 out_err_nosb:
2952         nfs_free_server(server);
2953 out_err_noserver:
2954         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2955         return error;
2956
2957 error_splat_super:
2958         if (server && !s->s_root)
2959                 bdi_unregister(&server->backing_dev_info);
2960 error_splat_bdi:
2961         deactivate_locked_super(s);
2962         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2963         return error;
2964 }
2965
2966 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2967                 int flags, const char *dev_name, void *raw_data,
2968                 struct vfsmount *mnt)
2969 {
2970         struct nfs_clone_mount *data = raw_data;
2971         struct super_block *s;
2972         struct nfs_server *server;
2973         struct dentry *mntroot;
2974         struct nfs_fh *mntfh;
2975         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2976         struct nfs_sb_mountdata sb_mntdata = {
2977                 .mntflags = flags,
2978         };
2979         int error = -ENOMEM;
2980
2981         dprintk("--> nfs4_referral_get_sb()\n");
2982
2983         mntfh = nfs_alloc_fhandle();
2984         if (mntfh == NULL)
2985                 goto out_err_nofh;
2986
2987         /* create a new volume representation */
2988         server = nfs4_create_referral_server(data, mntfh);
2989         if (IS_ERR(server)) {
2990                 error = PTR_ERR(server);
2991                 goto out_err_noserver;
2992         }
2993         sb_mntdata.server = server;
2994
2995         if (server->flags & NFS4_MOUNT_UNSHARED)
2996                 compare_super = NULL;
2997
2998         /* Get a superblock - note that we may end up sharing one that already exists */
2999         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3000         if (IS_ERR(s)) {
3001                 error = PTR_ERR(s);
3002                 goto out_err_nosb;
3003         }
3004
3005         if (s->s_fs_info != server) {
3006                 nfs_free_server(server);
3007                 server = NULL;
3008         } else {
3009                 error = nfs_bdi_register(server);
3010                 if (error)
3011                         goto error_splat_bdi;
3012         }
3013
3014         if (!s->s_root) {
3015                 /* initial superblock/root creation */
3016                 nfs4_fill_super(s);
3017                 nfs_fscache_get_super_cookie(s, NULL, data);
3018         }
3019
3020         mntroot = nfs4_get_root(s, mntfh);
3021         if (IS_ERR(mntroot)) {
3022                 error = PTR_ERR(mntroot);
3023                 goto error_splat_super;
3024         }
3025         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3026                 dput(mntroot);
3027                 error = -ESTALE;
3028                 goto error_splat_super;
3029         }
3030
3031         s->s_flags |= MS_ACTIVE;
3032         mnt->mnt_sb = s;
3033         mnt->mnt_root = mntroot;
3034
3035         security_sb_clone_mnt_opts(data->sb, s);
3036
3037         nfs_free_fhandle(mntfh);
3038         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3039         return 0;
3040
3041 out_err_nosb:
3042         nfs_free_server(server);
3043 out_err_noserver:
3044         nfs_free_fhandle(mntfh);
3045 out_err_nofh:
3046         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3047         return error;
3048
3049 error_splat_super:
3050         if (server && !s->s_root)
3051                 bdi_unregister(&server->backing_dev_info);
3052 error_splat_bdi:
3053         deactivate_locked_super(s);
3054         nfs_free_fhandle(mntfh);
3055         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3056         return error;
3057 }
3058
3059 /*
3060  * Create an NFS4 server record on referral traversal
3061  */
3062 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
3063                 int flags, const char *dev_name, void *raw_data,
3064                 struct vfsmount *mnt)
3065 {
3066         struct nfs_clone_mount *data = raw_data;
3067         char *export_path;
3068         struct vfsmount *root_mnt;
3069         int error;
3070
3071         dprintk("--> nfs4_referral_get_sb()\n");
3072
3073         export_path = data->mnt_path;
3074         data->mnt_path = "/";
3075
3076         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3077                         flags, data, data->hostname);
3078         data->mnt_path = export_path;
3079
3080         error = PTR_ERR(root_mnt);
3081         if (IS_ERR(root_mnt))
3082                 goto out;
3083
3084         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
3085 out:
3086         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
3087                         error != 0 ? " [error]" : "");
3088         return error;
3089 }
3090
3091 #endif /* CONFIG_NFS_V4 */