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         .evict_inode    = nfs_evict_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         .evict_inode    = nfs4_evict_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         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 550                 return;
 551
 552         switch (sap->sa_family) {
 553         case AF_INET: {
 554                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 555                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 556                 break;
 557         }
 558         case AF_INET6: {
 559                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 560                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 561                 break;
 562         }
 563         default:
 564                 if (showdefaults)
 565                         seq_printf(m, ",mountaddr=unspecified");
 566         }
 567
 568         if (nfss->mountd_version || showdefaults)
 569                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 570         if (nfss->mountd_port || showdefaults)
 571                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 572
 573         nfs_show_mountd_netid(m, nfss, showdefaults);
 574 }
 575
 576 #ifdef CONFIG_NFS_V4
 577 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 578                                     int showdefaults)
 579 {
 580         struct nfs_client *clp = nfss->nfs_client;
 581
 582         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 583         seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
 584 }
 585 #else
 586 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 587                                     int showdefaults)
 588 {
 589 }
 590 #endif
 591
 592 /*
 593  * Describe the mount options in force on this server representation
 594  */
 595 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 596                                    int showdefaults)
 597 {
 598         static const struct proc_nfs_info {
 599                 int flag;
 600                 const char *str;
 601                 const char *nostr;
 602         } nfs_info[] = {
 603                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 604                 { NFS_MOUNT_POSIX, ",posix", "" },
 605                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 606                 { NFS_MOUNT_NOAC, ",noac", "" },
 607                 { NFS_MOUNT_NONLM, ",nolock", "" },
 608                 { NFS_MOUNT_NOACL, ",noacl", "" },
 609                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 610                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 611                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 612                 { 0, NULL, NULL }
 613         };
 614         const struct proc_nfs_info *nfs_infop;
 615         struct nfs_client *clp = nfss->nfs_client;
 616         u32 version = clp->rpc_ops->version;
 617
 618         seq_printf(m, ",vers=%u", version);
 619         seq_printf(m, ",rsize=%u", nfss->rsize);
 620         seq_printf(m, ",wsize=%u", nfss->wsize);
 621         if (nfss->bsize != 0)
 622                 seq_printf(m, ",bsize=%u", nfss->bsize);
 623         seq_printf(m, ",namlen=%u", nfss->namelen);
 624         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 625                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 626         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 627                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 628         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 629                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 630         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 631                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 632         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 633                 if (nfss->flags & nfs_infop->flag)
 634                         seq_puts(m, nfs_infop->str);
 635                 else
 636                         seq_puts(m, nfs_infop->nostr);
 637         }
 638         seq_printf(m, ",proto=%s",
 639                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 640         if (version == 4) {
 641                 if (nfss->port != NFS_PORT)
 642                         seq_printf(m, ",port=%u", nfss->port);
 643         } else
 644                 if (nfss->port)
 645                         seq_printf(m, ",port=%u", nfss->port);
 646
 647         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 648         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 649         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 650
 651         if (version != 4)
 652                 nfs_show_mountd_options(m, nfss, showdefaults);
 653         else
 654                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 655
 656         if (nfss->options & NFS_OPTION_FSCACHE)
 657                 seq_printf(m, ",fsc");
 658 }
 659
 660 /*
 661  * Describe the mount options on this VFS mountpoint
 662  */
 663 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 664 {
 665         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 666
 667         nfs_show_mount_options(m, nfss, 0);
 668
 669         seq_printf(m, ",addr=%s",
 670                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 671                                                         RPC_DISPLAY_ADDR));
 672
 673         return 0;
 674 }
 675
 676 /*
 677  * Present statistical information for this VFS mountpoint
 678  */
 679 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 680 {
 681         int i, cpu;
 682         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 683         struct rpc_auth *auth = nfss->client->cl_auth;
 684         struct nfs_iostats totals = { };
 685
 686         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 687
 688         /*
 689          * Display all mount option settings
 690          */
 691         seq_printf(m, "\n\topts:\t");
 692         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 693         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 694         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 695         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 696         nfs_show_mount_options(m, nfss, 1);
 697
 698         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 699
 700         seq_printf(m, "\n\tcaps:\t");
 701         seq_printf(m, "caps=0x%x", nfss->caps);
 702         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 703         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 704         seq_printf(m, ",bsize=%u", nfss->bsize);
 705         seq_printf(m, ",namlen=%u", nfss->namelen);
 706
 707 #ifdef CONFIG_NFS_V4
 708         if (nfss->nfs_client->rpc_ops->version == 4) {
 709                 seq_printf(m, "\n\tnfsv4:\t");
 710                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 711                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 712                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 713         }
 714 #endif
 715
 716         /*
 717          * Display security flavor in effect for this mount
 718          */
 719         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 720         if (auth->au_flavor)
 721                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 722
 723         /*
 724          * Display superblock I/O counters
 725          */
 726         for_each_possible_cpu(cpu) {
 727                 struct nfs_iostats *stats;
 728
 729                 preempt_disable();
 730                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 731
 732                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 733                         totals.events[i] += stats->events[i];
 734                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 735                         totals.bytes[i] += stats->bytes[i];
 736 #ifdef CONFIG_NFS_FSCACHE
 737                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 738                         totals.fscache[i] += stats->fscache[i];
 739 #endif
 740
 741                 preempt_enable();
 742         }
 743
 744         seq_printf(m, "\n\tevents:\t");
 745         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 746                 seq_printf(m, "%lu ", totals.events[i]);
 747         seq_printf(m, "\n\tbytes:\t");
 748         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 749                 seq_printf(m, "%Lu ", totals.bytes[i]);
 750 #ifdef CONFIG_NFS_FSCACHE
 751         if (nfss->options & NFS_OPTION_FSCACHE) {
 752                 seq_printf(m, "\n\tfsc:\t");
 753                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 754                         seq_printf(m, "%Lu ", totals.bytes[i]);
 755         }
 756 #endif
 757         seq_printf(m, "\n");
 758
 759         rpc_print_iostats(m, nfss->client);
 760
 761         return 0;
 762 }
 763
 764 /*
 765  * Begin unmount by attempting to remove all automounted mountpoints we added
 766  * in response to xdev traversals and referrals
 767  */
 768 static void nfs_umount_begin(struct super_block *sb)
 769 {
 770         struct nfs_server *server;
 771         struct rpc_clnt *rpc;
 772
 773         server = NFS_SB(sb);
 774         /* -EIO all pending I/O */
 775         rpc = server->client_acl;
 776         if (!IS_ERR(rpc))
 777                 rpc_killall_tasks(rpc);
 778         rpc = server->client;
 779         if (!IS_ERR(rpc))
 780                 rpc_killall_tasks(rpc);
 781 }
 782
 783 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 784 {
 785         struct nfs_parsed_mount_data *data;
 786
 787         data = kzalloc(sizeof(*data), GFP_KERNEL);
 788         if (data) {
 789                 data->acregmin          = NFS_DEF_ACREGMIN;
 790                 data->acregmax          = NFS_DEF_ACREGMAX;
 791                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 792                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 793                 data->mount_server.port = NFS_UNSPEC_PORT;
 794                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 795                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 796                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 797                 data->auth_flavor_len   = 1;
 798                 data->version           = version;
 799                 data->minorversion      = 0;
 800         }
 801         return data;
 802 }
 803
 804 /*
 805  * Sanity-check a server address provided by the mount command.
 806  *
 807  * Address family must be initialized, and address must not be
 808  * the ANY address for that family.
 809  */
 810 static int nfs_verify_server_address(struct sockaddr *addr)
 811 {
 812         switch (addr->sa_family) {
 813         case AF_INET: {
 814                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 815                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 816         }
 817         case AF_INET6: {
 818                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 819                 return !ipv6_addr_any(sa);
 820         }
 821         }
 822
 823         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 824         return 0;
 825 }
 826
 827 /*
 828  * Select between a default port value and a user-specified port value.
 829  * If a zero value is set, then autobind will be used.
 830  */
 831 static void nfs_set_port(struct sockaddr *sap, int *port,
 832                                  const unsigned short default_port)
 833 {
 834         if (*port == NFS_UNSPEC_PORT)
 835                 *port = default_port;
 836
 837         rpc_set_port(sap, *port);
 838 }
 839
 840 /*
 841  * Sanity check the NFS transport protocol.
 842  *
 843  */
 844 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 845 {
 846         switch (mnt->nfs_server.protocol) {
 847         case XPRT_TRANSPORT_UDP:
 848         case XPRT_TRANSPORT_TCP:
 849         case XPRT_TRANSPORT_RDMA:
 850                 break;
 851         default:
 852                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 853         }
 854 }
 855
 856 /*
 857  * For text based NFSv2/v3 mounts, the mount protocol transport default
 858  * settings should depend upon the specified NFS transport.
 859  */
 860 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 861 {
 862         nfs_validate_transport_protocol(mnt);
 863
 864         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 865             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 866                         return;
 867         switch (mnt->nfs_server.protocol) {
 868         case XPRT_TRANSPORT_UDP:
 869                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 870                 break;
 871         case XPRT_TRANSPORT_TCP:
 872         case XPRT_TRANSPORT_RDMA:
 873                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 874         }
 875 }
 876
 877 /*
 878  * Parse the value of the 'sec=' option.
 879  */
 880 static int nfs_parse_security_flavors(char *value,
 881                                       struct nfs_parsed_mount_data *mnt)
 882 {
 883         substring_t args[MAX_OPT_ARGS];
 884
 885         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 886
 887         switch (match_token(value, nfs_secflavor_tokens, args)) {
 888         case Opt_sec_none:
 889                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 890                 break;
 891         case Opt_sec_sys:
 892                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 893                 break;
 894         case Opt_sec_krb5:
 895                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 896                 break;
 897         case Opt_sec_krb5i:
 898                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 899                 break;
 900         case Opt_sec_krb5p:
 901                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 902                 break;
 903         case Opt_sec_lkey:
 904                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 905                 break;
 906         case Opt_sec_lkeyi:
 907                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 908                 break;
 909         case Opt_sec_lkeyp:
 910                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 911                 break;
 912         case Opt_sec_spkm:
 913                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 914                 break;
 915         case Opt_sec_spkmi:
 916                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 917                 break;
 918         case Opt_sec_spkmp:
 919                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 920                 break;
 921         default:
 922                 return 0;
 923         }
 924
 925         mnt->auth_flavor_len = 1;
 926         return 1;
 927 }
 928
 929 /*
 930  * Error-check and convert a string of mount options from user space into
 931  * a data structure.  The whole mount string is processed; bad options are
 932  * skipped as they are encountered.  If there were no errors, return 1;
 933  * otherwise return 0 (zero).
 934  */
 935 static int nfs_parse_mount_options(char *raw,
 936                                    struct nfs_parsed_mount_data *mnt)
 937 {
 938         char *p, *string, *secdata;
 939         int rc, sloppy = 0, invalid_option = 0;
 940         unsigned short protofamily = AF_UNSPEC;
 941         unsigned short mountfamily = AF_UNSPEC;
 942
 943         if (!raw) {
 944                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 945                 return 1;
 946         }
 947         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 948
 949         secdata = alloc_secdata();
 950         if (!secdata)
 951                 goto out_nomem;
 952
 953         rc = security_sb_copy_data(raw, secdata);
 954         if (rc)
 955                 goto out_security_failure;
 956
 957         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 958         if (rc)
 959                 goto out_security_failure;
 960
 961         free_secdata(secdata);
 962
 963         while ((p = strsep(&raw, ",")) != NULL) {
 964                 substring_t args[MAX_OPT_ARGS];
 965                 unsigned long option;
 966                 int token;
 967
 968                 if (!*p)
 969                         continue;
 970
 971                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 972
 973                 token = match_token(p, nfs_mount_option_tokens, args);
 974                 switch (token) {
 975
 976                 /*
 977                  * boolean options:  foo/nofoo
 978                  */
 979                 case Opt_soft:
 980                         mnt->flags |= NFS_MOUNT_SOFT;
 981                         break;
 982                 case Opt_hard:
 983                         mnt->flags &= ~NFS_MOUNT_SOFT;
 984                         break;
 985                 case Opt_posix:
 986                         mnt->flags |= NFS_MOUNT_POSIX;
 987                         break;
 988                 case Opt_noposix:
 989                         mnt->flags &= ~NFS_MOUNT_POSIX;
 990                         break;
 991                 case Opt_cto:
 992                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 993                         break;
 994                 case Opt_nocto:
 995                         mnt->flags |= NFS_MOUNT_NOCTO;
 996                         break;
 997                 case Opt_ac:
 998                         mnt->flags &= ~NFS_MOUNT_NOAC;
 999                         break;
1000                 case Opt_noac:
1001                         mnt->flags |= NFS_MOUNT_NOAC;
1002                         break;
1003                 case Opt_lock:
1004                         mnt->flags &= ~NFS_MOUNT_NONLM;
1005                         break;
1006                 case Opt_nolock:
1007                         mnt->flags |= NFS_MOUNT_NONLM;
1008                         break;
1009                 case Opt_v2:
1010                         mnt->flags &= ~NFS_MOUNT_VER3;
1011                         mnt->version = 2;
1012                         break;
1013                 case Opt_v3:
1014                         mnt->flags |= NFS_MOUNT_VER3;
1015                         mnt->version = 3;
1016                         break;
1017 #ifdef CONFIG_NFS_V4
1018                 case Opt_v4:
1019                         mnt->flags &= ~NFS_MOUNT_VER3;
1020                         mnt->version = 4;
1021                         break;
1022 #endif
1023                 case Opt_udp:
1024                         mnt->flags &= ~NFS_MOUNT_TCP;
1025                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1026                         break;
1027                 case Opt_tcp:
1028                         mnt->flags |= NFS_MOUNT_TCP;
1029                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1030                         break;
1031                 case Opt_rdma:
1032                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1033                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1034                         xprt_load_transport(p);
1035                         break;
1036                 case Opt_acl:
1037                         mnt->flags &= ~NFS_MOUNT_NOACL;
1038                         break;
1039                 case Opt_noacl:
1040                         mnt->flags |= NFS_MOUNT_NOACL;
1041                         break;
1042                 case Opt_rdirplus:
1043                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1044                         break;
1045                 case Opt_nordirplus:
1046                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1047                         break;
1048                 case Opt_sharecache:
1049                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1050                         break;
1051                 case Opt_nosharecache:
1052                         mnt->flags |= NFS_MOUNT_UNSHARED;
1053                         break;
1054                 case Opt_resvport:
1055                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1056                         break;
1057                 case Opt_noresvport:
1058                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1059                         break;
1060                 case Opt_fscache:
1061                         mnt->options |= NFS_OPTION_FSCACHE;
1062                         kfree(mnt->fscache_uniq);
1063                         mnt->fscache_uniq = NULL;
1064                         break;
1065                 case Opt_nofscache:
1066                         mnt->options &= ~NFS_OPTION_FSCACHE;
1067                         kfree(mnt->fscache_uniq);
1068                         mnt->fscache_uniq = NULL;
1069                         break;
1070
1071                 /*
1072                  * options that take numeric values
1073                  */
1074                 case Opt_port:
1075                         string = match_strdup(args);
1076                         if (string == NULL)
1077                                 goto out_nomem;
1078                         rc = strict_strtoul(string, 10, &option);
1079                         kfree(string);
1080                         if (rc != 0 || option > USHRT_MAX)
1081                                 goto out_invalid_value;
1082                         mnt->nfs_server.port = option;
1083                         break;
1084                 case Opt_rsize:
1085                         string = match_strdup(args);
1086                         if (string == NULL)
1087                                 goto out_nomem;
1088                         rc = strict_strtoul(string, 10, &option);
1089                         kfree(string);
1090                         if (rc != 0)
1091                                 goto out_invalid_value;
1092                         mnt->rsize = option;
1093                         break;
1094                 case Opt_wsize:
1095                         string = match_strdup(args);
1096                         if (string == NULL)
1097                                 goto out_nomem;
1098                         rc = strict_strtoul(string, 10, &option);
1099                         kfree(string);
1100                         if (rc != 0)
1101                                 goto out_invalid_value;
1102                         mnt->wsize = option;
1103                         break;
1104                 case Opt_bsize:
1105                         string = match_strdup(args);
1106                         if (string == NULL)
1107                                 goto out_nomem;
1108                         rc = strict_strtoul(string, 10, &option);
1109                         kfree(string);
1110                         if (rc != 0)
1111                                 goto out_invalid_value;
1112                         mnt->bsize = option;
1113                         break;
1114                 case Opt_timeo:
1115                         string = match_strdup(args);
1116                         if (string == NULL)
1117                                 goto out_nomem;
1118                         rc = strict_strtoul(string, 10, &option);
1119                         kfree(string);
1120                         if (rc != 0 || option == 0)
1121                                 goto out_invalid_value;
1122                         mnt->timeo = option;
1123                         break;
1124                 case Opt_retrans:
1125                         string = match_strdup(args);
1126                         if (string == NULL)
1127                                 goto out_nomem;
1128                         rc = strict_strtoul(string, 10, &option);
1129                         kfree(string);
1130                         if (rc != 0 || option == 0)
1131                                 goto out_invalid_value;
1132                         mnt->retrans = option;
1133                         break;
1134                 case Opt_acregmin:
1135                         string = match_strdup(args);
1136                         if (string == NULL)
1137                                 goto out_nomem;
1138                         rc = strict_strtoul(string, 10, &option);
1139                         kfree(string);
1140                         if (rc != 0)
1141                                 goto out_invalid_value;
1142                         mnt->acregmin = option;
1143                         break;
1144                 case Opt_acregmax:
1145                         string = match_strdup(args);
1146                         if (string == NULL)
1147                                 goto out_nomem;
1148                         rc = strict_strtoul(string, 10, &option);
1149                         kfree(string);
1150                         if (rc != 0)
1151                                 goto out_invalid_value;
1152                         mnt->acregmax = option;
1153                         break;
1154                 case Opt_acdirmin:
1155                         string = match_strdup(args);
1156                         if (string == NULL)
1157                                 goto out_nomem;
1158                         rc = strict_strtoul(string, 10, &option);
1159                         kfree(string);
1160                         if (rc != 0)
1161                                 goto out_invalid_value;
1162                         mnt->acdirmin = option;
1163                         break;
1164                 case Opt_acdirmax:
1165                         string = match_strdup(args);
1166                         if (string == NULL)
1167                                 goto out_nomem;
1168                         rc = strict_strtoul(string, 10, &option);
1169                         kfree(string);
1170                         if (rc != 0)
1171                                 goto out_invalid_value;
1172                         mnt->acdirmax = option;
1173                         break;
1174                 case Opt_actimeo:
1175                         string = match_strdup(args);
1176                         if (string == NULL)
1177                                 goto out_nomem;
1178                         rc = strict_strtoul(string, 10, &option);
1179                         kfree(string);
1180                         if (rc != 0)
1181                                 goto out_invalid_value;
1182                         mnt->acregmin = mnt->acregmax =
1183                         mnt->acdirmin = mnt->acdirmax = option;
1184                         break;
1185                 case Opt_namelen:
1186                         string = match_strdup(args);
1187                         if (string == NULL)
1188                                 goto out_nomem;
1189                         rc = strict_strtoul(string, 10, &option);
1190                         kfree(string);
1191                         if (rc != 0)
1192                                 goto out_invalid_value;
1193                         mnt->namlen = option;
1194                         break;
1195                 case Opt_mountport:
1196                         string = match_strdup(args);
1197                         if (string == NULL)
1198                                 goto out_nomem;
1199                         rc = strict_strtoul(string, 10, &option);
1200                         kfree(string);
1201                         if (rc != 0 || option > USHRT_MAX)
1202                                 goto out_invalid_value;
1203                         mnt->mount_server.port = option;
1204                         break;
1205                 case Opt_mountvers:
1206                         string = match_strdup(args);
1207                         if (string == NULL)
1208                                 goto out_nomem;
1209                         rc = strict_strtoul(string, 10, &option);
1210                         kfree(string);
1211                         if (rc != 0 ||
1212                             option < NFS_MNT_VERSION ||
1213                             option > NFS_MNT3_VERSION)
1214                                 goto out_invalid_value;
1215                         mnt->mount_server.version = option;
1216                         break;
1217                 case Opt_nfsvers:
1218                         string = match_strdup(args);
1219                         if (string == NULL)
1220                                 goto out_nomem;
1221                         rc = strict_strtoul(string, 10, &option);
1222                         kfree(string);
1223                         if (rc != 0)
1224                                 goto out_invalid_value;
1225                         switch (option) {
1226                         case NFS2_VERSION:
1227                                 mnt->flags &= ~NFS_MOUNT_VER3;
1228                                 mnt->version = 2;
1229                                 break;
1230                         case NFS3_VERSION:
1231                                 mnt->flags |= NFS_MOUNT_VER3;
1232                                 mnt->version = 3;
1233                                 break;
1234 #ifdef CONFIG_NFS_V4
1235                         case NFS4_VERSION:
1236                                 mnt->flags &= ~NFS_MOUNT_VER3;
1237                                 mnt->version = 4;
1238                                 break;
1239 #endif
1240                         default:
1241                                 goto out_invalid_value;
1242                         }
1243                         break;
1244                 case Opt_minorversion:
1245                         string = match_strdup(args);
1246                         if (string == NULL)
1247                                 goto out_nomem;
1248                         rc = strict_strtoul(string, 10, &option);
1249                         kfree(string);
1250                         if (rc != 0)
1251                                 goto out_invalid_value;
1252                         if (option > NFS4_MAX_MINOR_VERSION)
1253                                 goto out_invalid_value;
1254                         mnt->minorversion = option;
1255                         break;
1256
1257                 /*
1258                  * options that take text values
1259                  */
1260                 case Opt_sec:
1261                         string = match_strdup(args);
1262                         if (string == NULL)
1263                                 goto out_nomem;
1264                         rc = nfs_parse_security_flavors(string, mnt);
1265                         kfree(string);
1266                         if (!rc) {
1267                                 dfprintk(MOUNT, "NFS:   unrecognized "
1268                                                 "security flavor\n");
1269                                 return 0;
1270                         }
1271                         break;
1272                 case Opt_proto:
1273                         string = match_strdup(args);
1274                         if (string == NULL)
1275                                 goto out_nomem;
1276                         token = match_token(string,
1277                                             nfs_xprt_protocol_tokens, args);
1278
1279                         protofamily = AF_INET;
1280                         switch (token) {
1281                         case Opt_xprt_udp6:
1282                                 protofamily = AF_INET6;
1283                         case Opt_xprt_udp:
1284                                 mnt->flags &= ~NFS_MOUNT_TCP;
1285                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1286                                 kfree(string);
1287                                 break;
1288                         case Opt_xprt_tcp6:
1289                                 protofamily = AF_INET6;
1290                         case Opt_xprt_tcp:
1291                                 mnt->flags |= NFS_MOUNT_TCP;
1292                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1293                                 kfree(string);
1294                                 break;
1295                         case Opt_xprt_rdma:
1296                                 /* vector side protocols to TCP */
1297                                 mnt->flags |= NFS_MOUNT_TCP;
1298                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1299                                 xprt_load_transport(string);
1300                                 kfree(string);
1301                                 break;
1302                         default:
1303                                 dfprintk(MOUNT, "NFS:   unrecognized "
1304                                                 "transport protocol\n");
1305                                 kfree(string);
1306                                 return 0;
1307                         }
1308                         break;
1309                 case Opt_mountproto:
1310                         string = match_strdup(args);
1311                         if (string == NULL)
1312                                 goto out_nomem;
1313                         token = match_token(string,
1314                                             nfs_xprt_protocol_tokens, args);
1315                         kfree(string);
1316
1317                         mountfamily = AF_INET;
1318                         switch (token) {
1319                         case Opt_xprt_udp6:
1320                                 mountfamily = AF_INET6;
1321                         case Opt_xprt_udp:
1322                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1323                                 break;
1324                         case Opt_xprt_tcp6:
1325                                 mountfamily = AF_INET6;
1326                         case Opt_xprt_tcp:
1327                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1328                                 break;
1329                         case Opt_xprt_rdma: /* not used for side protocols */
1330                         default:
1331                                 dfprintk(MOUNT, "NFS:   unrecognized "
1332                                                 "transport protocol\n");
1333                                 return 0;
1334                         }
1335                         break;
1336                 case Opt_addr:
1337                         string = match_strdup(args);
1338                         if (string == NULL)
1339                                 goto out_nomem;
1340                         mnt->nfs_server.addrlen =
1341                                 rpc_pton(string, strlen(string),
1342                                         (struct sockaddr *)
1343                                         &mnt->nfs_server.address,
1344                                         sizeof(mnt->nfs_server.address));
1345                         kfree(string);
1346                         if (mnt->nfs_server.addrlen == 0)
1347                                 goto out_invalid_address;
1348                         break;
1349                 case Opt_clientaddr:
1350                         string = match_strdup(args);
1351                         if (string == NULL)
1352                                 goto out_nomem;
1353                         kfree(mnt->client_address);
1354                         mnt->client_address = string;
1355                         break;
1356                 case Opt_mounthost:
1357                         string = match_strdup(args);
1358                         if (string == NULL)
1359                                 goto out_nomem;
1360                         kfree(mnt->mount_server.hostname);
1361                         mnt->mount_server.hostname = string;
1362                         break;
1363                 case Opt_mountaddr:
1364                         string = match_strdup(args);
1365                         if (string == NULL)
1366                                 goto out_nomem;
1367                         mnt->mount_server.addrlen =
1368                                 rpc_pton(string, strlen(string),
1369                                         (struct sockaddr *)
1370                                         &mnt->mount_server.address,
1371                                         sizeof(mnt->mount_server.address));
1372                         kfree(string);
1373                         if (mnt->mount_server.addrlen == 0)
1374                                 goto out_invalid_address;
1375                         break;
1376                 case Opt_lookupcache:
1377                         string = match_strdup(args);
1378                         if (string == NULL)
1379                                 goto out_nomem;
1380                         token = match_token(string,
1381                                         nfs_lookupcache_tokens, args);
1382                         kfree(string);
1383                         switch (token) {
1384                                 case Opt_lookupcache_all:
1385                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1386                                         break;
1387                                 case Opt_lookupcache_positive:
1388                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1389                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1390                                         break;
1391                                 case Opt_lookupcache_none:
1392                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1393                                         break;
1394                                 default:
1395                                         dfprintk(MOUNT, "NFS:   invalid "
1396                                                         "lookupcache argument\n");
1397                                         return 0;
1398                         };
1399                         break;
1400                 case Opt_fscache_uniq:
1401                         string = match_strdup(args);
1402                         if (string == NULL)
1403                                 goto out_nomem;
1404                         kfree(mnt->fscache_uniq);
1405                         mnt->fscache_uniq = string;
1406                         mnt->options |= NFS_OPTION_FSCACHE;
1407                         break;
1408
1409                 /*
1410                  * Special options
1411                  */
1412                 case Opt_sloppy:
1413                         sloppy = 1;
1414                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1415                         break;
1416                 case Opt_userspace:
1417                 case Opt_deprecated:
1418                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1419                                         "'%s'\n", p);
1420                         break;
1421
1422                 default:
1423                         invalid_option = 1;
1424                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1425                                         "'%s'\n", p);
1426                 }
1427         }
1428
1429         if (!sloppy && invalid_option)
1430                 return 0;
1431
1432         /*
1433          * verify that any proto=/mountproto= options match the address
1434          * familiies in the addr=/mountaddr= options.
1435          */
1436         if (protofamily != AF_UNSPEC &&
1437             protofamily != mnt->nfs_server.address.ss_family)
1438                 goto out_proto_mismatch;
1439
1440         if (mountfamily != AF_UNSPEC) {
1441                 if (mnt->mount_server.addrlen) {
1442                         if (mountfamily != mnt->mount_server.address.ss_family)
1443                                 goto out_mountproto_mismatch;
1444                 } else {
1445                         if (mountfamily != mnt->nfs_server.address.ss_family)
1446                                 goto out_mountproto_mismatch;
1447                 }
1448         }
1449
1450         return 1;
1451
1452 out_mountproto_mismatch:
1453         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1454                          "option\n");
1455         return 0;
1456 out_proto_mismatch:
1457         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1458         return 0;
1459 out_invalid_address:
1460         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1461         return 0;
1462 out_invalid_value:
1463         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1464         return 0;
1465 out_nomem:
1466         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1467         return 0;
1468 out_security_failure:
1469         free_secdata(secdata);
1470         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1471         return 0;
1472 }
1473
1474 /*
1475  * Match the requested auth flavors with the list returned by
1476  * the server.  Returns zero and sets the mount's authentication
1477  * flavor on success; returns -EACCES if server does not support
1478  * the requested flavor.
1479  */
1480 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1481                              struct nfs_mount_request *request)
1482 {
1483         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1484
1485         /*
1486          * Certain releases of Linux's mountd return an empty
1487          * flavor list.  To prevent behavioral regression with
1488          * these servers (ie. rejecting mounts that used to
1489          * succeed), revert to pre-2.6.32 behavior (no checking)
1490          * if the returned flavor list is empty.
1491          */
1492         if (server_authlist_len == 0)
1493                 return 0;
1494
1495         /*
1496          * We avoid sophisticated negotiating here, as there are
1497          * plenty of cases where we can get it wrong, providing
1498          * either too little or too much security.
1499          *
1500          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1501          * flavor listed first.  However, some servers list
1502          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1503          * preferred default, in args->auth_flavors[0] if user
1504          * didn't specify sec= mount option.
1505          */
1506         for (i = 0; i < args->auth_flavor_len; i++)
1507                 for (j = 0; j < server_authlist_len; j++)
1508                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1509                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1510                                         request->auth_flavs[j]);
1511                                 args->auth_flavors[0] = request->auth_flavs[j];
1512                                 return 0;
1513                         }
1514
1515         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1516         nfs_umount(request);
1517         return -EACCES;
1518 }
1519
1520 /*
1521  * Use the remote server's MOUNT service to request the NFS file handle
1522  * corresponding to the provided path.
1523  */
1524 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1525                          struct nfs_fh *root_fh)
1526 {
1527         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1528         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1529         struct nfs_mount_request request = {
1530                 .sap            = (struct sockaddr *)
1531                                                 &args->mount_server.address,
1532                 .dirpath        = args->nfs_server.export_path,
1533                 .protocol       = args->mount_server.protocol,
1534                 .fh             = root_fh,
1535                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1536                 .auth_flav_len  = &server_authlist_len,
1537                 .auth_flavs     = server_authlist,
1538         };
1539         int status;
1540
1541         if (args->mount_server.version == 0) {
1542                 switch (args->version) {
1543                         default:
1544                                 args->mount_server.version = NFS_MNT3_VERSION;
1545                                 break;
1546                         case 2:
1547                                 args->mount_server.version = NFS_MNT_VERSION;
1548                 }
1549         }
1550         request.version = args->mount_server.version;
1551
1552         if (args->mount_server.hostname)
1553                 request.hostname = args->mount_server.hostname;
1554         else
1555                 request.hostname = args->nfs_server.hostname;
1556
1557         /*
1558          * Construct the mount server's address.
1559          */
1560         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1561                 memcpy(request.sap, &args->nfs_server.address,
1562                        args->nfs_server.addrlen);
1563                 args->mount_server.addrlen = args->nfs_server.addrlen;
1564         }
1565         request.salen = args->mount_server.addrlen;
1566         nfs_set_port(request.sap, &args->mount_server.port, 0);
1567
1568         /*
1569          * Now ask the mount server to map our export path
1570          * to a file handle.
1571          */
1572         status = nfs_mount(&request);
1573         if (status != 0) {
1574                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1575                                 request.hostname, status);
1576                 return status;
1577         }
1578
1579         /*
1580          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1581          */
1582         if (args->mount_server.version != NFS_MNT3_VERSION)
1583                 return 0;
1584         return nfs_walk_authlist(args, &request);
1585 }
1586
1587 static int nfs_parse_simple_hostname(const char *dev_name,
1588                                      char **hostname, size_t maxnamlen,
1589                                      char **export_path, size_t maxpathlen)
1590 {
1591         size_t len;
1592         char *colon, *comma;
1593
1594         colon = strchr(dev_name, ':');
1595         if (colon == NULL)
1596                 goto out_bad_devname;
1597
1598         len = colon - dev_name;
1599         if (len > maxnamlen)
1600                 goto out_hostname;
1601
1602         /* N.B. caller will free nfs_server.hostname in all cases */
1603         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1604         if (!*hostname)
1605                 goto out_nomem;
1606
1607         /* kill possible hostname list: not supported */
1608         comma = strchr(*hostname, ',');
1609         if (comma != NULL) {
1610                 if (comma == *hostname)
1611                         goto out_bad_devname;
1612                 *comma = '\0';
1613         }
1614
1615         colon++;
1616         len = strlen(colon);
1617         if (len > maxpathlen)
1618                 goto out_path;
1619         *export_path = kstrndup(colon, len, GFP_KERNEL);
1620         if (!*export_path)
1621                 goto out_nomem;
1622
1623         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1624         return 0;
1625
1626 out_bad_devname:
1627         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1628         return -EINVAL;
1629
1630 out_nomem:
1631         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1632         return -ENOMEM;
1633
1634 out_hostname:
1635         dfprintk(MOUNT, "NFS: server hostname too long\n");
1636         return -ENAMETOOLONG;
1637
1638 out_path:
1639         dfprintk(MOUNT, "NFS: export pathname too long\n");
1640         return -ENAMETOOLONG;
1641 }
1642
1643 /*
1644  * Hostname has square brackets around it because it contains one or
1645  * more colons.  We look for the first closing square bracket, and a
1646  * colon must follow it.
1647  */
1648 static int nfs_parse_protected_hostname(const char *dev_name,
1649                                         char **hostname, size_t maxnamlen,
1650                                         char **export_path, size_t maxpathlen)
1651 {
1652         size_t len;
1653         char *start, *end;
1654
1655         start = (char *)(dev_name + 1);
1656
1657         end = strchr(start, ']');
1658         if (end == NULL)
1659                 goto out_bad_devname;
1660         if (*(end + 1) != ':')
1661                 goto out_bad_devname;
1662
1663         len = end - start;
1664         if (len > maxnamlen)
1665                 goto out_hostname;
1666
1667         /* N.B. caller will free nfs_server.hostname in all cases */
1668         *hostname = kstrndup(start, len, GFP_KERNEL);
1669         if (*hostname == NULL)
1670                 goto out_nomem;
1671
1672         end += 2;
1673         len = strlen(end);
1674         if (len > maxpathlen)
1675                 goto out_path;
1676         *export_path = kstrndup(end, len, GFP_KERNEL);
1677         if (!*export_path)
1678                 goto out_nomem;
1679
1680         return 0;
1681
1682 out_bad_devname:
1683         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1684         return -EINVAL;
1685
1686 out_nomem:
1687         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1688         return -ENOMEM;
1689
1690 out_hostname:
1691         dfprintk(MOUNT, "NFS: server hostname too long\n");
1692         return -ENAMETOOLONG;
1693
1694 out_path:
1695         dfprintk(MOUNT, "NFS: export pathname too long\n");
1696         return -ENAMETOOLONG;
1697 }
1698
1699 /*
1700  * Split "dev_name" into "hostname:export_path".
1701  *
1702  * The leftmost colon demarks the split between the server's hostname
1703  * and the export path.  If the hostname starts with a left square
1704  * bracket, then it may contain colons.
1705  *
1706  * Note: caller frees hostname and export path, even on error.
1707  */
1708 static int nfs_parse_devname(const char *dev_name,
1709                              char **hostname, size_t maxnamlen,
1710                              char **export_path, size_t maxpathlen)
1711 {
1712         if (*dev_name == '[')
1713                 return nfs_parse_protected_hostname(dev_name,
1714                                                     hostname, maxnamlen,
1715                                                     export_path, maxpathlen);
1716
1717         return nfs_parse_simple_hostname(dev_name,
1718                                          hostname, maxnamlen,
1719                                          export_path, maxpathlen);
1720 }
1721
1722 /*
1723  * Validate the NFS2/NFS3 mount data
1724  * - fills in the mount root filehandle
1725  *
1726  * For option strings, user space handles the following behaviors:
1727  *
1728  * + DNS: mapping server host name to IP address ("addr=" option)
1729  *
1730  * + failure mode: how to behave if a mount request can't be handled
1731  *   immediately ("fg/bg" option)
1732  *
1733  * + retry: how often to retry a mount request ("retry=" option)
1734  *
1735  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1736  *   mountproto=tcp after mountproto=udp, and so on
1737  */
1738 static int nfs_validate_mount_data(void *options,
1739                                    struct nfs_parsed_mount_data *args,
1740                                    struct nfs_fh *mntfh,
1741                                    const char *dev_name)
1742 {
1743         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1744         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1745
1746         if (data == NULL)
1747                 goto out_no_data;
1748
1749         switch (data->version) {
1750         case 1:
1751                 data->namlen = 0;
1752         case 2:
1753                 data->bsize = 0;
1754         case 3:
1755                 if (data->flags & NFS_MOUNT_VER3)
1756                         goto out_no_v3;
1757                 data->root.size = NFS2_FHSIZE;
1758                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1759         case 4:
1760                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1761                         goto out_no_sec;
1762         case 5:
1763                 memset(data->context, 0, sizeof(data->context));
1764         case 6:
1765                 if (data->flags & NFS_MOUNT_VER3) {
1766                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1767                                 goto out_invalid_fh;
1768                         mntfh->size = data->root.size;
1769                         args->version = 3;
1770                 } else {
1771                         mntfh->size = NFS2_FHSIZE;
1772                         args->version = 2;
1773                 }
1774
1775
1776                 memcpy(mntfh->data, data->root.data, mntfh->size);
1777                 if (mntfh->size < sizeof(mntfh->data))
1778                         memset(mntfh->data + mntfh->size, 0,
1779                                sizeof(mntfh->data) - mntfh->size);
1780
1781                 /*
1782                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1783                  * can deal with.
1784                  */
1785                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1786                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1787                 args->rsize             = data->rsize;
1788                 args->wsize             = data->wsize;
1789                 args->timeo             = data->timeo;
1790                 args->retrans           = data->retrans;
1791                 args->acregmin          = data->acregmin;
1792                 args->acregmax          = data->acregmax;
1793                 args->acdirmin          = data->acdirmin;
1794                 args->acdirmax          = data->acdirmax;
1795
1796                 memcpy(sap, &data->addr, sizeof(data->addr));
1797                 args->nfs_server.addrlen = sizeof(data->addr);
1798                 if (!nfs_verify_server_address(sap))
1799                         goto out_no_address;
1800
1801                 if (!(data->flags & NFS_MOUNT_TCP))
1802                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1803                 /* N.B. caller will free nfs_server.hostname in all cases */
1804                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1805                 args->namlen            = data->namlen;
1806                 args->bsize             = data->bsize;
1807
1808                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1809                         args->auth_flavors[0] = data->pseudoflavor;
1810                 if (!args->nfs_server.hostname)
1811                         goto out_nomem;
1812
1813                 /*
1814                  * The legacy version 6 binary mount data from userspace has a
1815                  * field used only to transport selinux information into the
1816                  * the kernel.  To continue to support that functionality we
1817                  * have a touch of selinux knowledge here in the NFS code. The
1818                  * userspace code converted context=blah to just blah so we are
1819                  * converting back to the full string selinux understands.
1820                  */
1821                 if (data->context[0]){
1822 #ifdef CONFIG_SECURITY_SELINUX
1823                         int rc;
1824                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1825                         if (!opts_str)
1826                                 return -ENOMEM;
1827                         strcpy(opts_str, "context=");
1828                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1829                         strcat(opts_str, &data->context[0]);
1830                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1831                         kfree(opts_str);
1832                         if (rc)
1833                                 return rc;
1834 #else
1835                         return -EINVAL;
1836 #endif
1837                 }
1838
1839                 break;
1840         default: {
1841                 int status;
1842
1843                 if (nfs_parse_mount_options((char *)options, args) == 0)
1844                         return -EINVAL;
1845
1846                 if (!nfs_verify_server_address(sap))
1847                         goto out_no_address;
1848
1849                 if (args->version == 4)
1850 #ifdef CONFIG_NFS_V4
1851                         return nfs4_validate_text_mount_data(options,
1852                                                              args, dev_name);
1853 #else
1854                         goto out_v4_not_compiled;
1855 #endif
1856
1857                 nfs_set_port(sap, &args->nfs_server.port, 0);
1858
1859                 nfs_set_mount_transport_protocol(args);
1860
1861                 status = nfs_parse_devname(dev_name,
1862                                            &args->nfs_server.hostname,
1863                                            PAGE_SIZE,
1864                                            &args->nfs_server.export_path,
1865                                            NFS_MAXPATHLEN);
1866                 if (!status)
1867                         status = nfs_try_mount(args, mntfh);
1868
1869                 kfree(args->nfs_server.export_path);
1870                 args->nfs_server.export_path = NULL;
1871
1872                 if (status)
1873                         return status;
1874
1875                 break;
1876                 }
1877         }
1878
1879 #ifndef CONFIG_NFS_V3
1880         if (args->version == 3)
1881                 goto out_v3_not_compiled;
1882 #endif /* !CONFIG_NFS_V3 */
1883
1884         return 0;
1885
1886 out_no_data:
1887         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1888         return -EINVAL;
1889
1890 out_no_v3:
1891         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1892                  data->version);
1893         return -EINVAL;
1894
1895 out_no_sec:
1896         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1897         return -EINVAL;
1898
1899 #ifndef CONFIG_NFS_V3
1900 out_v3_not_compiled:
1901         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1902         return -EPROTONOSUPPORT;
1903 #endif /* !CONFIG_NFS_V3 */
1904
1905 #ifndef CONFIG_NFS_V4
1906 out_v4_not_compiled:
1907         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1908         return -EPROTONOSUPPORT;
1909 #endif /* !CONFIG_NFS_V4 */
1910
1911 out_nomem:
1912         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1913         return -ENOMEM;
1914
1915 out_no_address:
1916         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1917         return -EINVAL;
1918
1919 out_invalid_fh:
1920         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1921         return -EINVAL;
1922 }
1923
1924 static int
1925 nfs_compare_remount_data(struct nfs_server *nfss,
1926                          struct nfs_parsed_mount_data *data)
1927 {
1928         if (data->flags != nfss->flags ||
1929             data->rsize != nfss->rsize ||
1930             data->wsize != nfss->wsize ||
1931             data->retrans != nfss->client->cl_timeout->to_retries ||
1932             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1933             data->acregmin != nfss->acregmin / HZ ||
1934             data->acregmax != nfss->acregmax / HZ ||
1935             data->acdirmin != nfss->acdirmin / HZ ||
1936             data->acdirmax != nfss->acdirmax / HZ ||
1937             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1938             data->nfs_server.port != nfss->port ||
1939             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1940             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1941                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
1942                 return -EINVAL;
1943
1944         return 0;
1945 }
1946
1947 static int
1948 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1949 {
1950         int error;
1951         struct nfs_server *nfss = sb->s_fs_info;
1952         struct nfs_parsed_mount_data *data;
1953         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1954         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1955         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1956
1957         /*
1958          * Userspace mount programs that send binary options generally send
1959          * them populated with default values. We have no way to know which
1960          * ones were explicitly specified. Fall back to legacy behavior and
1961          * just return success.
1962          */
1963         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1964             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1965                                            options->version <= 6))))
1966                 return 0;
1967
1968         data = kzalloc(sizeof(*data), GFP_KERNEL);
1969         if (data == NULL)
1970                 return -ENOMEM;
1971
1972         /* fill out struct with values from existing mount */
1973         data->flags = nfss->flags;
1974         data->rsize = nfss->rsize;
1975         data->wsize = nfss->wsize;
1976         data->retrans = nfss->client->cl_timeout->to_retries;
1977         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1978         data->acregmin = nfss->acregmin / HZ;
1979         data->acregmax = nfss->acregmax / HZ;
1980         data->acdirmin = nfss->acdirmin / HZ;
1981         data->acdirmax = nfss->acdirmax / HZ;
1982         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1983         data->nfs_server.port = nfss->port;
1984         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1985         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1986                 data->nfs_server.addrlen);
1987
1988         /* overwrite those values with any that were specified */
1989         error = nfs_parse_mount_options((char *)options, data);
1990         if (error < 0)
1991                 goto out;
1992
1993         /* compare new mount options with old ones */
1994         error = nfs_compare_remount_data(nfss, data);
1995 out:
1996         kfree(data);
1997         return error;
1998 }
1999
2000 /*
2001  * Initialise the common bits of the superblock
2002  */
2003 static inline void nfs_initialise_sb(struct super_block *sb)
2004 {
2005         struct nfs_server *server = NFS_SB(sb);
2006
2007         sb->s_magic = NFS_SUPER_MAGIC;
2008
2009         /* We probably want something more informative here */
2010         snprintf(sb->s_id, sizeof(sb->s_id),
2011                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2012
2013         if (sb->s_blocksize == 0)
2014                 sb->s_blocksize = nfs_block_bits(server->wsize,
2015                                                  &sb->s_blocksize_bits);
2016
2017         if (server->flags & NFS_MOUNT_NOAC)
2018                 sb->s_flags |= MS_SYNCHRONOUS;
2019
2020         sb->s_bdi = &server->backing_dev_info;
2021
2022         nfs_super_set_maxbytes(sb, server->maxfilesize);
2023 }
2024
2025 /*
2026  * Finish setting up an NFS2/3 superblock
2027  */
2028 static void nfs_fill_super(struct super_block *sb,
2029                            struct nfs_parsed_mount_data *data)
2030 {
2031         struct nfs_server *server = NFS_SB(sb);
2032
2033         sb->s_blocksize_bits = 0;
2034         sb->s_blocksize = 0;
2035         if (data->bsize)
2036                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2037
2038         if (server->nfs_client->rpc_ops->version == 3) {
2039                 /* The VFS shouldn't apply the umask to mode bits. We will do
2040                  * so ourselves when necessary.
2041                  */
2042                 sb->s_flags |= MS_POSIXACL;
2043                 sb->s_time_gran = 1;
2044         }
2045
2046         sb->s_op = &nfs_sops;
2047         nfs_initialise_sb(sb);
2048 }
2049
2050 /*
2051  * Finish setting up a cloned NFS2/3 superblock
2052  */
2053 static void nfs_clone_super(struct super_block *sb,
2054                             const struct super_block *old_sb)
2055 {
2056         struct nfs_server *server = NFS_SB(sb);
2057
2058         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2059         sb->s_blocksize = old_sb->s_blocksize;
2060         sb->s_maxbytes = old_sb->s_maxbytes;
2061
2062         if (server->nfs_client->rpc_ops->version == 3) {
2063                 /* The VFS shouldn't apply the umask to mode bits. We will do
2064                  * so ourselves when necessary.
2065                  */
2066                 sb->s_flags |= MS_POSIXACL;
2067                 sb->s_time_gran = 1;
2068         }
2069
2070         sb->s_op = old_sb->s_op;
2071         nfs_initialise_sb(sb);
2072 }
2073
2074 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2075 {
2076         const struct nfs_server *a = s->s_fs_info;
2077         const struct rpc_clnt *clnt_a = a->client;
2078         const struct rpc_clnt *clnt_b = b->client;
2079
2080         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2081                 goto Ebusy;
2082         if (a->nfs_client != b->nfs_client)
2083                 goto Ebusy;
2084         if (a->flags != b->flags)
2085                 goto Ebusy;
2086         if (a->wsize != b->wsize)
2087                 goto Ebusy;
2088         if (a->rsize != b->rsize)
2089                 goto Ebusy;
2090         if (a->acregmin != b->acregmin)
2091                 goto Ebusy;
2092         if (a->acregmax != b->acregmax)
2093                 goto Ebusy;
2094         if (a->acdirmin != b->acdirmin)
2095                 goto Ebusy;
2096         if (a->acdirmax != b->acdirmax)
2097                 goto Ebusy;
2098         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2099                 goto Ebusy;
2100         return 1;
2101 Ebusy:
2102         return 0;
2103 }
2104
2105 struct nfs_sb_mountdata {
2106         struct nfs_server *server;
2107         int mntflags;
2108 };
2109
2110 static int nfs_set_super(struct super_block *s, void *data)
2111 {
2112         struct nfs_sb_mountdata *sb_mntdata = data;
2113         struct nfs_server *server = sb_mntdata->server;
2114         int ret;
2115
2116         s->s_flags = sb_mntdata->mntflags;
2117         s->s_fs_info = server;
2118         ret = set_anon_super(s, server);
2119         if (ret == 0)
2120                 server->s_dev = s->s_dev;
2121         return ret;
2122 }
2123
2124 static int nfs_compare_super_address(struct nfs_server *server1,
2125                                      struct nfs_server *server2)
2126 {
2127         struct sockaddr *sap1, *sap2;
2128
2129         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2130         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2131
2132         if (sap1->sa_family != sap2->sa_family)
2133                 return 0;
2134
2135         switch (sap1->sa_family) {
2136         case AF_INET: {
2137                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2138                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2139                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2140                         return 0;
2141                 if (sin1->sin_port != sin2->sin_port)
2142                         return 0;
2143                 break;
2144         }
2145         case AF_INET6: {
2146                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2147                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2148                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2149                         return 0;
2150                 if (sin1->sin6_port != sin2->sin6_port)
2151                         return 0;
2152                 break;
2153         }
2154         default:
2155                 return 0;
2156         }
2157
2158         return 1;
2159 }
2160
2161 static int nfs_compare_super(struct super_block *sb, void *data)
2162 {
2163         struct nfs_sb_mountdata *sb_mntdata = data;
2164         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2165         int mntflags = sb_mntdata->mntflags;
2166
2167         if (!nfs_compare_super_address(old, server))
2168                 return 0;
2169         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2170         if (old->flags & NFS_MOUNT_UNSHARED)
2171                 return 0;
2172         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2173                 return 0;
2174         return nfs_compare_mount_options(sb, server, mntflags);
2175 }
2176
2177 static int nfs_bdi_register(struct nfs_server *server)
2178 {
2179         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2180 }
2181
2182 static int nfs_get_sb(struct file_system_type *fs_type,
2183         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2184 {
2185         struct nfs_server *server = NULL;
2186         struct super_block *s;
2187         struct nfs_parsed_mount_data *data;
2188         struct nfs_fh *mntfh;
2189         struct dentry *mntroot;
2190         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2191         struct nfs_sb_mountdata sb_mntdata = {
2192                 .mntflags = flags,
2193         };
2194         int error = -ENOMEM;
2195
2196         data = nfs_alloc_parsed_mount_data(3);
2197         mntfh = nfs_alloc_fhandle();
2198         if (data == NULL || mntfh == NULL)
2199                 goto out_free_fh;
2200
2201         security_init_mnt_opts(&data->lsm_opts);
2202
2203         /* Validate the mount data */
2204         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2205         if (error < 0)
2206                 goto out;
2207
2208 #ifdef CONFIG_NFS_V4
2209         if (data->version == 4) {
2210                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2211                 kfree(data->client_address);
2212                 kfree(data->nfs_server.export_path);
2213                 goto out;
2214         }
2215 #endif  /* CONFIG_NFS_V4 */
2216
2217         /* Get a volume representation */
2218         server = nfs_create_server(data, mntfh);
2219         if (IS_ERR(server)) {
2220                 error = PTR_ERR(server);
2221                 goto out;
2222         }
2223         sb_mntdata.server = server;
2224
2225         if (server->flags & NFS_MOUNT_UNSHARED)
2226                 compare_super = NULL;
2227
2228         /* Get a superblock - note that we may end up sharing one that already exists */
2229         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2230         if (IS_ERR(s)) {
2231                 error = PTR_ERR(s);
2232                 goto out_err_nosb;
2233         }
2234
2235         if (s->s_fs_info != server) {
2236                 nfs_free_server(server);
2237                 server = NULL;
2238         } else {
2239                 error = nfs_bdi_register(server);
2240                 if (error)
2241                         goto error_splat_bdi;
2242         }
2243
2244         if (!s->s_root) {
2245                 /* initial superblock/root creation */
2246                 nfs_fill_super(s, data);
2247                 nfs_fscache_get_super_cookie(
2248                         s, data ? data->fscache_uniq : NULL, NULL);
2249         }
2250
2251         mntroot = nfs_get_root(s, mntfh);
2252         if (IS_ERR(mntroot)) {
2253                 error = PTR_ERR(mntroot);
2254                 goto error_splat_super;
2255         }
2256
2257         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2258         if (error)
2259                 goto error_splat_root;
2260
2261         s->s_flags |= MS_ACTIVE;
2262         mnt->mnt_sb = s;
2263         mnt->mnt_root = mntroot;
2264         error = 0;
2265
2266 out:
2267         kfree(data->nfs_server.hostname);
2268         kfree(data->mount_server.hostname);
2269         kfree(data->fscache_uniq);
2270         security_free_mnt_opts(&data->lsm_opts);
2271 out_free_fh:
2272         nfs_free_fhandle(mntfh);
2273         kfree(data);
2274         return error;
2275
2276 out_err_nosb:
2277         nfs_free_server(server);
2278         goto out;
2279
2280 error_splat_root:
2281         dput(mntroot);
2282 error_splat_super:
2283         if (server && !s->s_root)
2284                 bdi_unregister(&server->backing_dev_info);
2285 error_splat_bdi:
2286         deactivate_locked_super(s);
2287         goto out;
2288 }
2289
2290 /*
2291  * Ensure that we unregister the bdi before kill_anon_super
2292  * releases the device name
2293  */
2294 static void nfs_put_super(struct super_block *s)
2295 {
2296         struct nfs_server *server = NFS_SB(s);
2297
2298         bdi_unregister(&server->backing_dev_info);
2299 }
2300
2301 /*
2302  * Destroy an NFS2/3 superblock
2303  */
2304 static void nfs_kill_super(struct super_block *s)
2305 {
2306         struct nfs_server *server = NFS_SB(s);
2307
2308         kill_anon_super(s);
2309         nfs_fscache_release_super_cookie(s);
2310         nfs_free_server(server);
2311 }
2312
2313 /*
2314  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2315  */
2316 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2317                            const char *dev_name, void *raw_data,
2318                            struct vfsmount *mnt)
2319 {
2320         struct nfs_clone_mount *data = raw_data;
2321         struct super_block *s;
2322         struct nfs_server *server;
2323         struct dentry *mntroot;
2324         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2325         struct nfs_sb_mountdata sb_mntdata = {
2326                 .mntflags = flags,
2327         };
2328         int error;
2329
2330         dprintk("--> nfs_xdev_get_sb()\n");
2331
2332         /* create a new volume representation */
2333         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2334         if (IS_ERR(server)) {
2335                 error = PTR_ERR(server);
2336                 goto out_err_noserver;
2337         }
2338         sb_mntdata.server = server;
2339
2340         if (server->flags & NFS_MOUNT_UNSHARED)
2341                 compare_super = NULL;
2342
2343         /* Get a superblock - note that we may end up sharing one that already exists */
2344         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2345         if (IS_ERR(s)) {
2346                 error = PTR_ERR(s);
2347                 goto out_err_nosb;
2348         }
2349
2350         if (s->s_fs_info != server) {
2351                 nfs_free_server(server);
2352                 server = NULL;
2353         } else {
2354                 error = nfs_bdi_register(server);
2355                 if (error)
2356                         goto error_splat_bdi;
2357         }
2358
2359         if (!s->s_root) {
2360                 /* initial superblock/root creation */
2361                 nfs_clone_super(s, data->sb);
2362                 nfs_fscache_get_super_cookie(s, NULL, data);
2363         }
2364
2365         mntroot = nfs_get_root(s, data->fh);
2366         if (IS_ERR(mntroot)) {
2367                 error = PTR_ERR(mntroot);
2368                 goto error_splat_super;
2369         }
2370         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2371                 dput(mntroot);
2372                 error = -ESTALE;
2373                 goto error_splat_super;
2374         }
2375
2376         s->s_flags |= MS_ACTIVE;
2377         mnt->mnt_sb = s;
2378         mnt->mnt_root = mntroot;
2379
2380         /* clone any lsm security options from the parent to the new sb */
2381         security_sb_clone_mnt_opts(data->sb, s);
2382
2383         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2384         return 0;
2385
2386 out_err_nosb:
2387         nfs_free_server(server);
2388 out_err_noserver:
2389         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2390         return error;
2391
2392 error_splat_super:
2393         if (server && !s->s_root)
2394                 bdi_unregister(&server->backing_dev_info);
2395 error_splat_bdi:
2396         deactivate_locked_super(s);
2397         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2398         return error;
2399 }
2400
2401 #ifdef CONFIG_NFS_V4
2402
2403 /*
2404  * Finish setting up a cloned NFS4 superblock
2405  */
2406 static void nfs4_clone_super(struct super_block *sb,
2407                             const struct super_block *old_sb)
2408 {
2409         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2410         sb->s_blocksize = old_sb->s_blocksize;
2411         sb->s_maxbytes = old_sb->s_maxbytes;
2412         sb->s_time_gran = 1;
2413         sb->s_op = old_sb->s_op;
2414         nfs_initialise_sb(sb);
2415 }
2416
2417 /*
2418  * Set up an NFS4 superblock
2419  */
2420 static void nfs4_fill_super(struct super_block *sb)
2421 {
2422         sb->s_time_gran = 1;
2423         sb->s_op = &nfs4_sops;
2424         nfs_initialise_sb(sb);
2425 }
2426
2427 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2428 {
2429         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2430 }
2431
2432 static int nfs4_validate_text_mount_data(void *options,
2433                                          struct nfs_parsed_mount_data *args,
2434                                          const char *dev_name)
2435 {
2436         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2437
2438         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2439
2440         nfs_validate_transport_protocol(args);
2441
2442         nfs4_validate_mount_flags(args);
2443
2444         if (args->version != 4) {
2445                 dfprintk(MOUNT,
2446                          "NFS4: Illegal mount version\n");
2447                 return -EINVAL;
2448         }
2449
2450         if (args->auth_flavor_len > 1) {
2451                 dfprintk(MOUNT,
2452                          "NFS4: Too many RPC auth flavours specified\n");
2453                 return -EINVAL;
2454         }
2455
2456         if (args->client_address == NULL) {
2457                 dfprintk(MOUNT,
2458                          "NFS4: mount program didn't pass callback address\n");
2459                 return -EINVAL;
2460         }
2461
2462         return nfs_parse_devname(dev_name,
2463                                    &args->nfs_server.hostname,
2464                                    NFS4_MAXNAMLEN,
2465                                    &args->nfs_server.export_path,
2466                                    NFS4_MAXPATHLEN);
2467 }
2468
2469 /*
2470  * Validate NFSv4 mount options
2471  */
2472 static int nfs4_validate_mount_data(void *options,
2473                                     struct nfs_parsed_mount_data *args,
2474                                     const char *dev_name)
2475 {
2476         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2477         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2478         char *c;
2479
2480         if (data == NULL)
2481                 goto out_no_data;
2482
2483         switch (data->version) {
2484         case 1:
2485                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2486                         goto out_no_address;
2487                 if (data->host_addrlen == 0)
2488                         goto out_no_address;
2489                 args->nfs_server.addrlen = data->host_addrlen;
2490                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2491                         return -EFAULT;
2492                 if (!nfs_verify_server_address(sap))
2493                         goto out_no_address;
2494
2495                 if (data->auth_flavourlen) {
2496                         if (data->auth_flavourlen > 1)
2497                                 goto out_inval_auth;
2498                         if (copy_from_user(&args->auth_flavors[0],
2499                                            data->auth_flavours,
2500                                            sizeof(args->auth_flavors[0])))
2501                                 return -EFAULT;
2502                 }
2503
2504                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2505                 if (IS_ERR(c))
2506                         return PTR_ERR(c);
2507                 args->nfs_server.hostname = c;
2508
2509                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2510                 if (IS_ERR(c))
2511                         return PTR_ERR(c);
2512                 args->nfs_server.export_path = c;
2513                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2514
2515                 c = strndup_user(data->client_addr.data, 16);
2516                 if (IS_ERR(c))
2517                         return PTR_ERR(c);
2518                 args->client_address = c;
2519
2520                 /*
2521                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2522                  * can deal with.
2523                  */
2524
2525                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2526                 args->rsize     = data->rsize;
2527                 args->wsize     = data->wsize;
2528                 args->timeo     = data->timeo;
2529                 args->retrans   = data->retrans;
2530                 args->acregmin  = data->acregmin;
2531                 args->acregmax  = data->acregmax;
2532                 args->acdirmin  = data->acdirmin;
2533                 args->acdirmax  = data->acdirmax;
2534                 args->nfs_server.protocol = data->proto;
2535                 nfs_validate_transport_protocol(args);
2536
2537                 break;
2538         default:
2539                 if (nfs_parse_mount_options((char *)options, args) == 0)
2540                         return -EINVAL;
2541
2542                 if (!nfs_verify_server_address(sap))
2543                         return -EINVAL;
2544
2545                 return nfs4_validate_text_mount_data(options, args, dev_name);
2546         }
2547
2548         return 0;
2549
2550 out_no_data:
2551         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2552         return -EINVAL;
2553
2554 out_inval_auth:
2555         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2556                  data->auth_flavourlen);
2557         return -EINVAL;
2558
2559 out_no_address:
2560         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2561         return -EINVAL;
2562 }
2563
2564 /*
2565  * Get the superblock for the NFS4 root partition
2566  */
2567 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2568         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2569 {
2570         struct nfs_parsed_mount_data *data = raw_data;
2571         struct super_block *s;
2572         struct nfs_server *server;
2573         struct nfs_fh *mntfh;
2574         struct dentry *mntroot;
2575         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2576         struct nfs_sb_mountdata sb_mntdata = {
2577                 .mntflags = flags,
2578         };
2579         int error = -ENOMEM;
2580
2581         mntfh = nfs_alloc_fhandle();
2582         if (data == NULL || mntfh == NULL)
2583                 goto out_free_fh;
2584
2585         security_init_mnt_opts(&data->lsm_opts);
2586
2587         /* Get a volume representation */
2588         server = nfs4_create_server(data, mntfh);
2589         if (IS_ERR(server)) {
2590                 error = PTR_ERR(server);
2591                 goto out;
2592         }
2593         sb_mntdata.server = server;
2594
2595         if (server->flags & NFS4_MOUNT_UNSHARED)
2596                 compare_super = NULL;
2597
2598         /* Get a superblock - note that we may end up sharing one that already exists */
2599         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2600         if (IS_ERR(s)) {
2601                 error = PTR_ERR(s);
2602                 goto out_free;
2603         }
2604
2605         if (s->s_fs_info != server) {
2606                 nfs_free_server(server);
2607                 server = NULL;
2608         } else {
2609                 error = nfs_bdi_register(server);
2610                 if (error)
2611                         goto error_splat_bdi;
2612         }
2613
2614         if (!s->s_root) {
2615                 /* initial superblock/root creation */
2616                 nfs4_fill_super(s);
2617                 nfs_fscache_get_super_cookie(
2618                         s, data ? data->fscache_uniq : NULL, NULL);
2619         }
2620
2621         mntroot = nfs4_get_root(s, mntfh);
2622         if (IS_ERR(mntroot)) {
2623                 error = PTR_ERR(mntroot);
2624                 goto error_splat_super;
2625         }
2626
2627         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2628         if (error)
2629                 goto error_splat_root;
2630
2631         s->s_flags |= MS_ACTIVE;
2632         mnt->mnt_sb = s;
2633         mnt->mnt_root = mntroot;
2634         error = 0;
2635
2636 out:
2637         security_free_mnt_opts(&data->lsm_opts);
2638 out_free_fh:
2639         nfs_free_fhandle(mntfh);
2640         return error;
2641
2642 out_free:
2643         nfs_free_server(server);
2644         goto out;
2645
2646 error_splat_root:
2647         dput(mntroot);
2648 error_splat_super:
2649         if (server && !s->s_root)
2650                 bdi_unregister(&server->backing_dev_info);
2651 error_splat_bdi:
2652         deactivate_locked_super(s);
2653         goto out;
2654 }
2655
2656 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2657                 int flags, void *data, const char *hostname)
2658 {
2659         struct vfsmount *root_mnt;
2660         char *root_devname;
2661         size_t len;
2662
2663         len = strlen(hostname) + 3;
2664         root_devname = kmalloc(len, GFP_KERNEL);
2665         if (root_devname == NULL)
2666                 return ERR_PTR(-ENOMEM);
2667         snprintf(root_devname, len, "%s:/", hostname);
2668         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2669         kfree(root_devname);
2670         return root_mnt;
2671 }
2672
2673 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2674 {
2675         char *page = (char *) __get_free_page(GFP_KERNEL);
2676         char *devname, *tmp;
2677
2678         if (page == NULL)
2679                 return;
2680         devname = nfs_path(path->mnt->mnt_devname,
2681                         path->mnt->mnt_root, path->dentry,
2682                         page, PAGE_SIZE);
2683         if (IS_ERR(devname))
2684                 goto out_freepage;
2685         tmp = kstrdup(devname, GFP_KERNEL);
2686         if (tmp == NULL)
2687                 goto out_freepage;
2688         kfree(mnt->mnt_devname);
2689         mnt->mnt_devname = tmp;
2690 out_freepage:
2691         free_page((unsigned long)page);
2692 }
2693
2694 struct nfs_referral_count {
2695         struct list_head list;
2696         const struct task_struct *task;
2697         unsigned int referral_count;
2698 };
2699
2700 static LIST_HEAD(nfs_referral_count_list);
2701 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2702
2703 static struct nfs_referral_count *nfs_find_referral_count(void)
2704 {
2705         struct nfs_referral_count *p;
2706
2707         list_for_each_entry(p, &nfs_referral_count_list, list) {
2708                 if (p->task == current)
2709                         return p;
2710         }
2711         return NULL;
2712 }
2713
2714 #define NFS_MAX_NESTED_REFERRALS 2
2715
2716 static int nfs_referral_loop_protect(void)
2717 {
2718         struct nfs_referral_count *p, *new;
2719         int ret = -ENOMEM;
2720
2721         new = kmalloc(sizeof(*new), GFP_KERNEL);
2722         if (!new)
2723                 goto out;
2724         new->task = current;
2725         new->referral_count = 1;
2726
2727         ret = 0;
2728         spin_lock(&nfs_referral_count_list_lock);
2729         p = nfs_find_referral_count();
2730         if (p != NULL) {
2731                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2732                         ret = -ELOOP;
2733                 else
2734                         p->referral_count++;
2735         } else {
2736                 list_add(&new->list, &nfs_referral_count_list);
2737                 new = NULL;
2738         }
2739         spin_unlock(&nfs_referral_count_list_lock);
2740         kfree(new);
2741 out:
2742         return ret;
2743 }
2744
2745 static void nfs_referral_loop_unprotect(void)
2746 {
2747         struct nfs_referral_count *p;
2748
2749         spin_lock(&nfs_referral_count_list_lock);
2750         p = nfs_find_referral_count();
2751         p->referral_count--;
2752         if (p->referral_count == 0)
2753                 list_del(&p->list);
2754         else
2755                 p = NULL;
2756         spin_unlock(&nfs_referral_count_list_lock);
2757         kfree(p);
2758 }
2759
2760 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2761                 const char *export_path, struct vfsmount *mnt_target)
2762 {
2763         struct nameidata *nd = NULL;
2764         struct mnt_namespace *ns_private;
2765         struct super_block *s;
2766         int ret;
2767
2768         nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2769         if (nd == NULL)
2770                 return -ENOMEM;
2771
2772         ns_private = create_mnt_ns(root_mnt);
2773         ret = PTR_ERR(ns_private);
2774         if (IS_ERR(ns_private))
2775                 goto out_mntput;
2776
2777         ret = nfs_referral_loop_protect();
2778         if (ret != 0)
2779                 goto out_put_mnt_ns;
2780
2781         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2782                         export_path, LOOKUP_FOLLOW, nd);
2783
2784         nfs_referral_loop_unprotect();
2785         put_mnt_ns(ns_private);
2786
2787         if (ret != 0)
2788                 goto out_err;
2789
2790         s = nd->path.mnt->mnt_sb;
2791         atomic_inc(&s->s_active);
2792         mnt_target->mnt_sb = s;
2793         mnt_target->mnt_root = dget(nd->path.dentry);
2794
2795         /* Correct the device pathname */
2796         nfs_fix_devname(&nd->path, mnt_target);
2797
2798         path_put(&nd->path);
2799         kfree(nd);
2800         down_write(&s->s_umount);
2801         return 0;
2802 out_put_mnt_ns:
2803         put_mnt_ns(ns_private);
2804 out_mntput:
2805         mntput(root_mnt);
2806 out_err:
2807         kfree(nd);
2808         return ret;
2809 }
2810
2811 static int nfs4_try_mount(int flags, const char *dev_name,
2812                          struct nfs_parsed_mount_data *data,
2813                          struct vfsmount *mnt)
2814 {
2815         char *export_path;
2816         struct vfsmount *root_mnt;
2817         int error;
2818
2819         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2820
2821         export_path = data->nfs_server.export_path;
2822         data->nfs_server.export_path = "/";
2823         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2824                         data->nfs_server.hostname);
2825         data->nfs_server.export_path = export_path;
2826
2827         error = PTR_ERR(root_mnt);
2828         if (IS_ERR(root_mnt))
2829                 goto out;
2830
2831         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2832
2833 out:
2834         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2835                         error != 0 ? " [error]" : "");
2836         return error;
2837 }
2838
2839 /*
2840  * Get the superblock for an NFS4 mountpoint
2841  */
2842 static int nfs4_get_sb(struct file_system_type *fs_type,
2843         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2844 {
2845         struct nfs_parsed_mount_data *data;
2846         int error = -ENOMEM;
2847
2848         data = nfs_alloc_parsed_mount_data(4);
2849         if (data == NULL)
2850                 goto out_free_data;
2851
2852         /* Validate the mount data */
2853         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2854         if (error < 0)
2855                 goto out;
2856
2857         error = nfs4_try_mount(flags, dev_name, data, mnt);
2858
2859 out:
2860         kfree(data->client_address);
2861         kfree(data->nfs_server.export_path);
2862         kfree(data->nfs_server.hostname);
2863         kfree(data->fscache_uniq);
2864 out_free_data:
2865         kfree(data);
2866         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2867                         error != 0 ? " [error]" : "");
2868         return error;
2869 }
2870
2871 static void nfs4_kill_super(struct super_block *sb)
2872 {
2873         struct nfs_server *server = NFS_SB(sb);
2874
2875         dprintk("--> %s\n", __func__);
2876         nfs_super_return_all_delegations(sb);
2877         kill_anon_super(sb);
2878         nfs_fscache_release_super_cookie(sb);
2879         nfs_free_server(server);
2880         dprintk("<-- %s\n", __func__);
2881 }
2882
2883 /*
2884  * Clone an NFS4 server record on xdev traversal (FSID-change)
2885  */
2886 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2887                             const char *dev_name, void *raw_data,
2888                             struct vfsmount *mnt)
2889 {
2890         struct nfs_clone_mount *data = raw_data;
2891         struct super_block *s;
2892         struct nfs_server *server;
2893         struct dentry *mntroot;
2894         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2895         struct nfs_sb_mountdata sb_mntdata = {
2896                 .mntflags = flags,
2897         };
2898         int error;
2899
2900         dprintk("--> nfs4_xdev_get_sb()\n");
2901
2902         /* create a new volume representation */
2903         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2904         if (IS_ERR(server)) {
2905                 error = PTR_ERR(server);
2906                 goto out_err_noserver;
2907         }
2908         sb_mntdata.server = server;
2909
2910         if (server->flags & NFS4_MOUNT_UNSHARED)
2911                 compare_super = NULL;
2912
2913         /* Get a superblock - note that we may end up sharing one that already exists */
2914         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2915         if (IS_ERR(s)) {
2916                 error = PTR_ERR(s);
2917                 goto out_err_nosb;
2918         }
2919
2920         if (s->s_fs_info != server) {
2921                 nfs_free_server(server);
2922                 server = NULL;
2923         } else {
2924                 error = nfs_bdi_register(server);
2925                 if (error)
2926                         goto error_splat_bdi;
2927         }
2928
2929         if (!s->s_root) {
2930                 /* initial superblock/root creation */
2931                 nfs4_clone_super(s, data->sb);
2932                 nfs_fscache_get_super_cookie(s, NULL, data);
2933         }
2934
2935         mntroot = nfs4_get_root(s, data->fh);
2936         if (IS_ERR(mntroot)) {
2937                 error = PTR_ERR(mntroot);
2938                 goto error_splat_super;
2939         }
2940         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2941                 dput(mntroot);
2942                 error = -ESTALE;
2943                 goto error_splat_super;
2944         }
2945
2946         s->s_flags |= MS_ACTIVE;
2947         mnt->mnt_sb = s;
2948         mnt->mnt_root = mntroot;
2949
2950         security_sb_clone_mnt_opts(data->sb, s);
2951
2952         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2953         return 0;
2954
2955 out_err_nosb:
2956         nfs_free_server(server);
2957 out_err_noserver:
2958         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2959         return error;
2960
2961 error_splat_super:
2962         if (server && !s->s_root)
2963                 bdi_unregister(&server->backing_dev_info);
2964 error_splat_bdi:
2965         deactivate_locked_super(s);
2966         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2967         return error;
2968 }
2969
2970 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2971                 int flags, const char *dev_name, void *raw_data,
2972                 struct vfsmount *mnt)
2973 {
2974         struct nfs_clone_mount *data = raw_data;
2975         struct super_block *s;
2976         struct nfs_server *server;
2977         struct dentry *mntroot;
2978         struct nfs_fh *mntfh;
2979         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2980         struct nfs_sb_mountdata sb_mntdata = {
2981                 .mntflags = flags,
2982         };
2983         int error = -ENOMEM;
2984
2985         dprintk("--> nfs4_referral_get_sb()\n");
2986
2987         mntfh = nfs_alloc_fhandle();
2988         if (mntfh == NULL)
2989                 goto out_err_nofh;
2990
2991         /* create a new volume representation */
2992         server = nfs4_create_referral_server(data, mntfh);
2993         if (IS_ERR(server)) {
2994                 error = PTR_ERR(server);
2995                 goto out_err_noserver;
2996         }
2997         sb_mntdata.server = server;
2998
2999         if (server->flags & NFS4_MOUNT_UNSHARED)
3000                 compare_super = NULL;
3001
3002         /* Get a superblock - note that we may end up sharing one that already exists */
3003         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3004         if (IS_ERR(s)) {
3005                 error = PTR_ERR(s);
3006                 goto out_err_nosb;
3007         }
3008
3009         if (s->s_fs_info != server) {
3010                 nfs_free_server(server);
3011                 server = NULL;
3012         } else {
3013                 error = nfs_bdi_register(server);
3014                 if (error)
3015                         goto error_splat_bdi;
3016         }
3017
3018         if (!s->s_root) {
3019                 /* initial superblock/root creation */
3020                 nfs4_fill_super(s);
3021                 nfs_fscache_get_super_cookie(s, NULL, data);
3022         }
3023
3024         mntroot = nfs4_get_root(s, mntfh);
3025         if (IS_ERR(mntroot)) {
3026                 error = PTR_ERR(mntroot);
3027                 goto error_splat_super;
3028         }
3029         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3030                 dput(mntroot);
3031                 error = -ESTALE;
3032                 goto error_splat_super;
3033         }
3034
3035         s->s_flags |= MS_ACTIVE;
3036         mnt->mnt_sb = s;
3037         mnt->mnt_root = mntroot;
3038
3039         security_sb_clone_mnt_opts(data->sb, s);
3040
3041         nfs_free_fhandle(mntfh);
3042         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3043         return 0;
3044
3045 out_err_nosb:
3046         nfs_free_server(server);
3047 out_err_noserver:
3048         nfs_free_fhandle(mntfh);
3049 out_err_nofh:
3050         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3051         return error;
3052
3053 error_splat_super:
3054         if (server && !s->s_root)
3055                 bdi_unregister(&server->backing_dev_info);
3056 error_splat_bdi:
3057         deactivate_locked_super(s);
3058         nfs_free_fhandle(mntfh);
3059         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3060         return error;
3061 }
3062
3063 /*
3064  * Create an NFS4 server record on referral traversal
3065  */
3066 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
3067                 int flags, const char *dev_name, void *raw_data,
3068                 struct vfsmount *mnt)
3069 {
3070         struct nfs_clone_mount *data = raw_data;
3071         char *export_path;
3072         struct vfsmount *root_mnt;
3073         int error;
3074
3075         dprintk("--> nfs4_referral_get_sb()\n");
3076
3077         export_path = data->mnt_path;
3078         data->mnt_path = "/";
3079
3080         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3081                         flags, data, data->hostname);
3082         data->mnt_path = export_path;
3083
3084         error = PTR_ERR(root_mnt);
3085         if (IS_ERR(root_mnt))
3086                 goto out;
3087
3088         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
3089 out:
3090         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
3091                         error != 0 ? " [error]" : "");
3092         return error;
3093 }
3094
3095 #endif /* CONFIG_NFS_V4 */