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         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 660                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 661                         seq_printf(m, ",lookupcache=none");
 662                 else
 663                         seq_printf(m, ",lookupcache=pos");
 664         }
 665 }
 666
 667 /*
 668  * Describe the mount options on this VFS mountpoint
 669  */
 670 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 671 {
 672         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 673
 674         nfs_show_mount_options(m, nfss, 0);
 675
 676         seq_printf(m, ",addr=%s",
 677                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 678                                                         RPC_DISPLAY_ADDR));
 679
 680         return 0;
 681 }
 682
 683 /*
 684  * Present statistical information for this VFS mountpoint
 685  */
 686 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 687 {
 688         int i, cpu;
 689         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 690         struct rpc_auth *auth = nfss->client->cl_auth;
 691         struct nfs_iostats totals = { };
 692
 693         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 694
 695         /*
 696          * Display all mount option settings
 697          */
 698         seq_printf(m, "\n\topts:\t");
 699         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 700         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 701         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 702         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 703         nfs_show_mount_options(m, nfss, 1);
 704
 705         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 706
 707         seq_printf(m, "\n\tcaps:\t");
 708         seq_printf(m, "caps=0x%x", nfss->caps);
 709         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 710         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 711         seq_printf(m, ",bsize=%u", nfss->bsize);
 712         seq_printf(m, ",namlen=%u", nfss->namelen);
 713
 714 #ifdef CONFIG_NFS_V4
 715         if (nfss->nfs_client->rpc_ops->version == 4) {
 716                 seq_printf(m, "\n\tnfsv4:\t");
 717                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 718                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 719                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 720         }
 721 #endif
 722
 723         /*
 724          * Display security flavor in effect for this mount
 725          */
 726         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 727         if (auth->au_flavor)
 728                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 729
 730         /*
 731          * Display superblock I/O counters
 732          */
 733         for_each_possible_cpu(cpu) {
 734                 struct nfs_iostats *stats;
 735
 736                 preempt_disable();
 737                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 738
 739                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 740                         totals.events[i] += stats->events[i];
 741                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 742                         totals.bytes[i] += stats->bytes[i];
 743 #ifdef CONFIG_NFS_FSCACHE
 744                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 745                         totals.fscache[i] += stats->fscache[i];
 746 #endif
 747
 748                 preempt_enable();
 749         }
 750
 751         seq_printf(m, "\n\tevents:\t");
 752         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 753                 seq_printf(m, "%lu ", totals.events[i]);
 754         seq_printf(m, "\n\tbytes:\t");
 755         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 756                 seq_printf(m, "%Lu ", totals.bytes[i]);
 757 #ifdef CONFIG_NFS_FSCACHE
 758         if (nfss->options & NFS_OPTION_FSCACHE) {
 759                 seq_printf(m, "\n\tfsc:\t");
 760                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 761                         seq_printf(m, "%Lu ", totals.bytes[i]);
 762         }
 763 #endif
 764         seq_printf(m, "\n");
 765
 766         rpc_print_iostats(m, nfss->client);
 767
 768         return 0;
 769 }
 770
 771 /*
 772  * Begin unmount by attempting to remove all automounted mountpoints we added
 773  * in response to xdev traversals and referrals
 774  */
 775 static void nfs_umount_begin(struct super_block *sb)
 776 {
 777         struct nfs_server *server;
 778         struct rpc_clnt *rpc;
 779
 780         server = NFS_SB(sb);
 781         /* -EIO all pending I/O */
 782         rpc = server->client_acl;
 783         if (!IS_ERR(rpc))
 784                 rpc_killall_tasks(rpc);
 785         rpc = server->client;
 786         if (!IS_ERR(rpc))
 787                 rpc_killall_tasks(rpc);
 788 }
 789
 790 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 791 {
 792         struct nfs_parsed_mount_data *data;
 793
 794         data = kzalloc(sizeof(*data), GFP_KERNEL);
 795         if (data) {
 796                 data->acregmin          = NFS_DEF_ACREGMIN;
 797                 data->acregmax          = NFS_DEF_ACREGMAX;
 798                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 799                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 800                 data->mount_server.port = NFS_UNSPEC_PORT;
 801                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 802                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 803                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 804                 data->auth_flavor_len   = 1;
 805                 data->version           = version;
 806                 data->minorversion      = 0;
 807         }
 808         return data;
 809 }
 810
 811 /*
 812  * Sanity-check a server address provided by the mount command.
 813  *
 814  * Address family must be initialized, and address must not be
 815  * the ANY address for that family.
 816  */
 817 static int nfs_verify_server_address(struct sockaddr *addr)
 818 {
 819         switch (addr->sa_family) {
 820         case AF_INET: {
 821                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 822                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 823         }
 824         case AF_INET6: {
 825                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 826                 return !ipv6_addr_any(sa);
 827         }
 828         }
 829
 830         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 831         return 0;
 832 }
 833
 834 /*
 835  * Select between a default port value and a user-specified port value.
 836  * If a zero value is set, then autobind will be used.
 837  */
 838 static void nfs_set_port(struct sockaddr *sap, int *port,
 839                                  const unsigned short default_port)
 840 {
 841         if (*port == NFS_UNSPEC_PORT)
 842                 *port = default_port;
 843
 844         rpc_set_port(sap, *port);
 845 }
 846
 847 /*
 848  * Sanity check the NFS transport protocol.
 849  *
 850  */
 851 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 852 {
 853         switch (mnt->nfs_server.protocol) {
 854         case XPRT_TRANSPORT_UDP:
 855         case XPRT_TRANSPORT_TCP:
 856         case XPRT_TRANSPORT_RDMA:
 857                 break;
 858         default:
 859                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 860         }
 861 }
 862
 863 /*
 864  * For text based NFSv2/v3 mounts, the mount protocol transport default
 865  * settings should depend upon the specified NFS transport.
 866  */
 867 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 868 {
 869         nfs_validate_transport_protocol(mnt);
 870
 871         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 872             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 873                         return;
 874         switch (mnt->nfs_server.protocol) {
 875         case XPRT_TRANSPORT_UDP:
 876                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 877                 break;
 878         case XPRT_TRANSPORT_TCP:
 879         case XPRT_TRANSPORT_RDMA:
 880                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 881         }
 882 }
 883
 884 /*
 885  * Parse the value of the 'sec=' option.
 886  */
 887 static int nfs_parse_security_flavors(char *value,
 888                                       struct nfs_parsed_mount_data *mnt)
 889 {
 890         substring_t args[MAX_OPT_ARGS];
 891
 892         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 893
 894         switch (match_token(value, nfs_secflavor_tokens, args)) {
 895         case Opt_sec_none:
 896                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 897                 break;
 898         case Opt_sec_sys:
 899                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 900                 break;
 901         case Opt_sec_krb5:
 902                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 903                 break;
 904         case Opt_sec_krb5i:
 905                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 906                 break;
 907         case Opt_sec_krb5p:
 908                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 909                 break;
 910         case Opt_sec_lkey:
 911                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 912                 break;
 913         case Opt_sec_lkeyi:
 914                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 915                 break;
 916         case Opt_sec_lkeyp:
 917                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 918                 break;
 919         case Opt_sec_spkm:
 920                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 921                 break;
 922         case Opt_sec_spkmi:
 923                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 924                 break;
 925         case Opt_sec_spkmp:
 926                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 927                 break;
 928         default:
 929                 return 0;
 930         }
 931
 932         mnt->auth_flavor_len = 1;
 933         return 1;
 934 }
 935
 936 /*
 937  * Error-check and convert a string of mount options from user space into
 938  * a data structure.  The whole mount string is processed; bad options are
 939  * skipped as they are encountered.  If there were no errors, return 1;
 940  * otherwise return 0 (zero).
 941  */
 942 static int nfs_parse_mount_options(char *raw,
 943                                    struct nfs_parsed_mount_data *mnt)
 944 {
 945         char *p, *string, *secdata;
 946         int rc, sloppy = 0, invalid_option = 0;
 947         unsigned short protofamily = AF_UNSPEC;
 948         unsigned short mountfamily = AF_UNSPEC;
 949
 950         if (!raw) {
 951                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 952                 return 1;
 953         }
 954         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 955
 956         secdata = alloc_secdata();
 957         if (!secdata)
 958                 goto out_nomem;
 959
 960         rc = security_sb_copy_data(raw, secdata);
 961         if (rc)
 962                 goto out_security_failure;
 963
 964         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 965         if (rc)
 966                 goto out_security_failure;
 967
 968         free_secdata(secdata);
 969
 970         while ((p = strsep(&raw, ",")) != NULL) {
 971                 substring_t args[MAX_OPT_ARGS];
 972                 unsigned long option;
 973                 int token;
 974
 975                 if (!*p)
 976                         continue;
 977
 978                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 979
 980                 token = match_token(p, nfs_mount_option_tokens, args);
 981                 switch (token) {
 982
 983                 /*
 984                  * boolean options:  foo/nofoo
 985                  */
 986                 case Opt_soft:
 987                         mnt->flags |= NFS_MOUNT_SOFT;
 988                         break;
 989                 case Opt_hard:
 990                         mnt->flags &= ~NFS_MOUNT_SOFT;
 991                         break;
 992                 case Opt_posix:
 993                         mnt->flags |= NFS_MOUNT_POSIX;
 994                         break;
 995                 case Opt_noposix:
 996                         mnt->flags &= ~NFS_MOUNT_POSIX;
 997                         break;
 998                 case Opt_cto:
 999                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1000                         break;
1001                 case Opt_nocto:
1002                         mnt->flags |= NFS_MOUNT_NOCTO;
1003                         break;
1004                 case Opt_ac:
1005                         mnt->flags &= ~NFS_MOUNT_NOAC;
1006                         break;
1007                 case Opt_noac:
1008                         mnt->flags |= NFS_MOUNT_NOAC;
1009                         break;
1010                 case Opt_lock:
1011                         mnt->flags &= ~NFS_MOUNT_NONLM;
1012                         break;
1013                 case Opt_nolock:
1014                         mnt->flags |= NFS_MOUNT_NONLM;
1015                         break;
1016                 case Opt_v2:
1017                         mnt->flags &= ~NFS_MOUNT_VER3;
1018                         mnt->version = 2;
1019                         break;
1020                 case Opt_v3:
1021                         mnt->flags |= NFS_MOUNT_VER3;
1022                         mnt->version = 3;
1023                         break;
1024 #ifdef CONFIG_NFS_V4
1025                 case Opt_v4:
1026                         mnt->flags &= ~NFS_MOUNT_VER3;
1027                         mnt->version = 4;
1028                         break;
1029 #endif
1030                 case Opt_udp:
1031                         mnt->flags &= ~NFS_MOUNT_TCP;
1032                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1033                         break;
1034                 case Opt_tcp:
1035                         mnt->flags |= NFS_MOUNT_TCP;
1036                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1037                         break;
1038                 case Opt_rdma:
1039                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1040                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1041                         xprt_load_transport(p);
1042                         break;
1043                 case Opt_acl:
1044                         mnt->flags &= ~NFS_MOUNT_NOACL;
1045                         break;
1046                 case Opt_noacl:
1047                         mnt->flags |= NFS_MOUNT_NOACL;
1048                         break;
1049                 case Opt_rdirplus:
1050                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1051                         break;
1052                 case Opt_nordirplus:
1053                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1054                         break;
1055                 case Opt_sharecache:
1056                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1057                         break;
1058                 case Opt_nosharecache:
1059                         mnt->flags |= NFS_MOUNT_UNSHARED;
1060                         break;
1061                 case Opt_resvport:
1062                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1063                         break;
1064                 case Opt_noresvport:
1065                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1066                         break;
1067                 case Opt_fscache:
1068                         mnt->options |= NFS_OPTION_FSCACHE;
1069                         kfree(mnt->fscache_uniq);
1070                         mnt->fscache_uniq = NULL;
1071                         break;
1072                 case Opt_nofscache:
1073                         mnt->options &= ~NFS_OPTION_FSCACHE;
1074                         kfree(mnt->fscache_uniq);
1075                         mnt->fscache_uniq = NULL;
1076                         break;
1077
1078                 /*
1079                  * options that take numeric values
1080                  */
1081                 case Opt_port:
1082                         string = match_strdup(args);
1083                         if (string == NULL)
1084                                 goto out_nomem;
1085                         rc = strict_strtoul(string, 10, &option);
1086                         kfree(string);
1087                         if (rc != 0 || option > USHRT_MAX)
1088                                 goto out_invalid_value;
1089                         mnt->nfs_server.port = option;
1090                         break;
1091                 case Opt_rsize:
1092                         string = match_strdup(args);
1093                         if (string == NULL)
1094                                 goto out_nomem;
1095                         rc = strict_strtoul(string, 10, &option);
1096                         kfree(string);
1097                         if (rc != 0)
1098                                 goto out_invalid_value;
1099                         mnt->rsize = option;
1100                         break;
1101                 case Opt_wsize:
1102                         string = match_strdup(args);
1103                         if (string == NULL)
1104                                 goto out_nomem;
1105                         rc = strict_strtoul(string, 10, &option);
1106                         kfree(string);
1107                         if (rc != 0)
1108                                 goto out_invalid_value;
1109                         mnt->wsize = option;
1110                         break;
1111                 case Opt_bsize:
1112                         string = match_strdup(args);
1113                         if (string == NULL)
1114                                 goto out_nomem;
1115                         rc = strict_strtoul(string, 10, &option);
1116                         kfree(string);
1117                         if (rc != 0)
1118                                 goto out_invalid_value;
1119                         mnt->bsize = option;
1120                         break;
1121                 case Opt_timeo:
1122                         string = match_strdup(args);
1123                         if (string == NULL)
1124                                 goto out_nomem;
1125                         rc = strict_strtoul(string, 10, &option);
1126                         kfree(string);
1127                         if (rc != 0 || option == 0)
1128                                 goto out_invalid_value;
1129                         mnt->timeo = option;
1130                         break;
1131                 case Opt_retrans:
1132                         string = match_strdup(args);
1133                         if (string == NULL)
1134                                 goto out_nomem;
1135                         rc = strict_strtoul(string, 10, &option);
1136                         kfree(string);
1137                         if (rc != 0 || option == 0)
1138                                 goto out_invalid_value;
1139                         mnt->retrans = option;
1140                         break;
1141                 case Opt_acregmin:
1142                         string = match_strdup(args);
1143                         if (string == NULL)
1144                                 goto out_nomem;
1145                         rc = strict_strtoul(string, 10, &option);
1146                         kfree(string);
1147                         if (rc != 0)
1148                                 goto out_invalid_value;
1149                         mnt->acregmin = option;
1150                         break;
1151                 case Opt_acregmax:
1152                         string = match_strdup(args);
1153                         if (string == NULL)
1154                                 goto out_nomem;
1155                         rc = strict_strtoul(string, 10, &option);
1156                         kfree(string);
1157                         if (rc != 0)
1158                                 goto out_invalid_value;
1159                         mnt->acregmax = option;
1160                         break;
1161                 case Opt_acdirmin:
1162                         string = match_strdup(args);
1163                         if (string == NULL)
1164                                 goto out_nomem;
1165                         rc = strict_strtoul(string, 10, &option);
1166                         kfree(string);
1167                         if (rc != 0)
1168                                 goto out_invalid_value;
1169                         mnt->acdirmin = option;
1170                         break;
1171                 case Opt_acdirmax:
1172                         string = match_strdup(args);
1173                         if (string == NULL)
1174                                 goto out_nomem;
1175                         rc = strict_strtoul(string, 10, &option);
1176                         kfree(string);
1177                         if (rc != 0)
1178                                 goto out_invalid_value;
1179                         mnt->acdirmax = option;
1180                         break;
1181                 case Opt_actimeo:
1182                         string = match_strdup(args);
1183                         if (string == NULL)
1184                                 goto out_nomem;
1185                         rc = strict_strtoul(string, 10, &option);
1186                         kfree(string);
1187                         if (rc != 0)
1188                                 goto out_invalid_value;
1189                         mnt->acregmin = mnt->acregmax =
1190                         mnt->acdirmin = mnt->acdirmax = option;
1191                         break;
1192                 case Opt_namelen:
1193                         string = match_strdup(args);
1194                         if (string == NULL)
1195                                 goto out_nomem;
1196                         rc = strict_strtoul(string, 10, &option);
1197                         kfree(string);
1198                         if (rc != 0)
1199                                 goto out_invalid_value;
1200                         mnt->namlen = option;
1201                         break;
1202                 case Opt_mountport:
1203                         string = match_strdup(args);
1204                         if (string == NULL)
1205                                 goto out_nomem;
1206                         rc = strict_strtoul(string, 10, &option);
1207                         kfree(string);
1208                         if (rc != 0 || option > USHRT_MAX)
1209                                 goto out_invalid_value;
1210                         mnt->mount_server.port = option;
1211                         break;
1212                 case Opt_mountvers:
1213                         string = match_strdup(args);
1214                         if (string == NULL)
1215                                 goto out_nomem;
1216                         rc = strict_strtoul(string, 10, &option);
1217                         kfree(string);
1218                         if (rc != 0 ||
1219                             option < NFS_MNT_VERSION ||
1220                             option > NFS_MNT3_VERSION)
1221                                 goto out_invalid_value;
1222                         mnt->mount_server.version = option;
1223                         break;
1224                 case Opt_nfsvers:
1225                         string = match_strdup(args);
1226                         if (string == NULL)
1227                                 goto out_nomem;
1228                         rc = strict_strtoul(string, 10, &option);
1229                         kfree(string);
1230                         if (rc != 0)
1231                                 goto out_invalid_value;
1232                         switch (option) {
1233                         case NFS2_VERSION:
1234                                 mnt->flags &= ~NFS_MOUNT_VER3;
1235                                 mnt->version = 2;
1236                                 break;
1237                         case NFS3_VERSION:
1238                                 mnt->flags |= NFS_MOUNT_VER3;
1239                                 mnt->version = 3;
1240                                 break;
1241 #ifdef CONFIG_NFS_V4
1242                         case NFS4_VERSION:
1243                                 mnt->flags &= ~NFS_MOUNT_VER3;
1244                                 mnt->version = 4;
1245                                 break;
1246 #endif
1247                         default:
1248                                 goto out_invalid_value;
1249                         }
1250                         break;
1251                 case Opt_minorversion:
1252                         string = match_strdup(args);
1253                         if (string == NULL)
1254                                 goto out_nomem;
1255                         rc = strict_strtoul(string, 10, &option);
1256                         kfree(string);
1257                         if (rc != 0)
1258                                 goto out_invalid_value;
1259                         if (option > NFS4_MAX_MINOR_VERSION)
1260                                 goto out_invalid_value;
1261                         mnt->minorversion = option;
1262                         break;
1263
1264                 /*
1265                  * options that take text values
1266                  */
1267                 case Opt_sec:
1268                         string = match_strdup(args);
1269                         if (string == NULL)
1270                                 goto out_nomem;
1271                         rc = nfs_parse_security_flavors(string, mnt);
1272                         kfree(string);
1273                         if (!rc) {
1274                                 dfprintk(MOUNT, "NFS:   unrecognized "
1275                                                 "security flavor\n");
1276                                 return 0;
1277                         }
1278                         break;
1279                 case Opt_proto:
1280                         string = match_strdup(args);
1281                         if (string == NULL)
1282                                 goto out_nomem;
1283                         token = match_token(string,
1284                                             nfs_xprt_protocol_tokens, args);
1285
1286                         protofamily = AF_INET;
1287                         switch (token) {
1288                         case Opt_xprt_udp6:
1289                                 protofamily = AF_INET6;
1290                         case Opt_xprt_udp:
1291                                 mnt->flags &= ~NFS_MOUNT_TCP;
1292                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1293                                 kfree(string);
1294                                 break;
1295                         case Opt_xprt_tcp6:
1296                                 protofamily = AF_INET6;
1297                         case Opt_xprt_tcp:
1298                                 mnt->flags |= NFS_MOUNT_TCP;
1299                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1300                                 kfree(string);
1301                                 break;
1302                         case Opt_xprt_rdma:
1303                                 /* vector side protocols to TCP */
1304                                 mnt->flags |= NFS_MOUNT_TCP;
1305                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1306                                 xprt_load_transport(string);
1307                                 kfree(string);
1308                                 break;
1309                         default:
1310                                 dfprintk(MOUNT, "NFS:   unrecognized "
1311                                                 "transport protocol\n");
1312                                 kfree(string);
1313                                 return 0;
1314                         }
1315                         break;
1316                 case Opt_mountproto:
1317                         string = match_strdup(args);
1318                         if (string == NULL)
1319                                 goto out_nomem;
1320                         token = match_token(string,
1321                                             nfs_xprt_protocol_tokens, args);
1322                         kfree(string);
1323
1324                         mountfamily = AF_INET;
1325                         switch (token) {
1326                         case Opt_xprt_udp6:
1327                                 mountfamily = AF_INET6;
1328                         case Opt_xprt_udp:
1329                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1330                                 break;
1331                         case Opt_xprt_tcp6:
1332                                 mountfamily = AF_INET6;
1333                         case Opt_xprt_tcp:
1334                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1335                                 break;
1336                         case Opt_xprt_rdma: /* not used for side protocols */
1337                         default:
1338                                 dfprintk(MOUNT, "NFS:   unrecognized "
1339                                                 "transport protocol\n");
1340                                 return 0;
1341                         }
1342                         break;
1343                 case Opt_addr:
1344                         string = match_strdup(args);
1345                         if (string == NULL)
1346                                 goto out_nomem;
1347                         mnt->nfs_server.addrlen =
1348                                 rpc_pton(string, strlen(string),
1349                                         (struct sockaddr *)
1350                                         &mnt->nfs_server.address,
1351                                         sizeof(mnt->nfs_server.address));
1352                         kfree(string);
1353                         if (mnt->nfs_server.addrlen == 0)
1354                                 goto out_invalid_address;
1355                         break;
1356                 case Opt_clientaddr:
1357                         string = match_strdup(args);
1358                         if (string == NULL)
1359                                 goto out_nomem;
1360                         kfree(mnt->client_address);
1361                         mnt->client_address = string;
1362                         break;
1363                 case Opt_mounthost:
1364                         string = match_strdup(args);
1365                         if (string == NULL)
1366                                 goto out_nomem;
1367                         kfree(mnt->mount_server.hostname);
1368                         mnt->mount_server.hostname = string;
1369                         break;
1370                 case Opt_mountaddr:
1371                         string = match_strdup(args);
1372                         if (string == NULL)
1373                                 goto out_nomem;
1374                         mnt->mount_server.addrlen =
1375                                 rpc_pton(string, strlen(string),
1376                                         (struct sockaddr *)
1377                                         &mnt->mount_server.address,
1378                                         sizeof(mnt->mount_server.address));
1379                         kfree(string);
1380                         if (mnt->mount_server.addrlen == 0)
1381                                 goto out_invalid_address;
1382                         break;
1383                 case Opt_lookupcache:
1384                         string = match_strdup(args);
1385                         if (string == NULL)
1386                                 goto out_nomem;
1387                         token = match_token(string,
1388                                         nfs_lookupcache_tokens, args);
1389                         kfree(string);
1390                         switch (token) {
1391                                 case Opt_lookupcache_all:
1392                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1393                                         break;
1394                                 case Opt_lookupcache_positive:
1395                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1396                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1397                                         break;
1398                                 case Opt_lookupcache_none:
1399                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1400                                         break;
1401                                 default:
1402                                         dfprintk(MOUNT, "NFS:   invalid "
1403                                                         "lookupcache argument\n");
1404                                         return 0;
1405                         };
1406                         break;
1407                 case Opt_fscache_uniq:
1408                         string = match_strdup(args);
1409                         if (string == NULL)
1410                                 goto out_nomem;
1411                         kfree(mnt->fscache_uniq);
1412                         mnt->fscache_uniq = string;
1413                         mnt->options |= NFS_OPTION_FSCACHE;
1414                         break;
1415
1416                 /*
1417                  * Special options
1418                  */
1419                 case Opt_sloppy:
1420                         sloppy = 1;
1421                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1422                         break;
1423                 case Opt_userspace:
1424                 case Opt_deprecated:
1425                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1426                                         "'%s'\n", p);
1427                         break;
1428
1429                 default:
1430                         invalid_option = 1;
1431                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1432                                         "'%s'\n", p);
1433                 }
1434         }
1435
1436         if (!sloppy && invalid_option)
1437                 return 0;
1438
1439         /*
1440          * verify that any proto=/mountproto= options match the address
1441          * familiies in the addr=/mountaddr= options.
1442          */
1443         if (protofamily != AF_UNSPEC &&
1444             protofamily != mnt->nfs_server.address.ss_family)
1445                 goto out_proto_mismatch;
1446
1447         if (mountfamily != AF_UNSPEC) {
1448                 if (mnt->mount_server.addrlen) {
1449                         if (mountfamily != mnt->mount_server.address.ss_family)
1450                                 goto out_mountproto_mismatch;
1451                 } else {
1452                         if (mountfamily != mnt->nfs_server.address.ss_family)
1453                                 goto out_mountproto_mismatch;
1454                 }
1455         }
1456
1457         return 1;
1458
1459 out_mountproto_mismatch:
1460         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1461                          "option\n");
1462         return 0;
1463 out_proto_mismatch:
1464         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1465         return 0;
1466 out_invalid_address:
1467         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1468         return 0;
1469 out_invalid_value:
1470         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1471         return 0;
1472 out_nomem:
1473         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1474         return 0;
1475 out_security_failure:
1476         free_secdata(secdata);
1477         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1478         return 0;
1479 }
1480
1481 /*
1482  * Match the requested auth flavors with the list returned by
1483  * the server.  Returns zero and sets the mount's authentication
1484  * flavor on success; returns -EACCES if server does not support
1485  * the requested flavor.
1486  */
1487 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1488                              struct nfs_mount_request *request)
1489 {
1490         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1491
1492         /*
1493          * Certain releases of Linux's mountd return an empty
1494          * flavor list.  To prevent behavioral regression with
1495          * these servers (ie. rejecting mounts that used to
1496          * succeed), revert to pre-2.6.32 behavior (no checking)
1497          * if the returned flavor list is empty.
1498          */
1499         if (server_authlist_len == 0)
1500                 return 0;
1501
1502         /*
1503          * We avoid sophisticated negotiating here, as there are
1504          * plenty of cases where we can get it wrong, providing
1505          * either too little or too much security.
1506          *
1507          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1508          * flavor listed first.  However, some servers list
1509          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1510          * preferred default, in args->auth_flavors[0] if user
1511          * didn't specify sec= mount option.
1512          */
1513         for (i = 0; i < args->auth_flavor_len; i++)
1514                 for (j = 0; j < server_authlist_len; j++)
1515                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1516                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1517                                         request->auth_flavs[j]);
1518                                 args->auth_flavors[0] = request->auth_flavs[j];
1519                                 return 0;
1520                         }
1521
1522         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1523         nfs_umount(request);
1524         return -EACCES;
1525 }
1526
1527 /*
1528  * Use the remote server's MOUNT service to request the NFS file handle
1529  * corresponding to the provided path.
1530  */
1531 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1532                          struct nfs_fh *root_fh)
1533 {
1534         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1535         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1536         struct nfs_mount_request request = {
1537                 .sap            = (struct sockaddr *)
1538                                                 &args->mount_server.address,
1539                 .dirpath        = args->nfs_server.export_path,
1540                 .protocol       = args->mount_server.protocol,
1541                 .fh             = root_fh,
1542                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1543                 .auth_flav_len  = &server_authlist_len,
1544                 .auth_flavs     = server_authlist,
1545         };
1546         int status;
1547
1548         if (args->mount_server.version == 0) {
1549                 switch (args->version) {
1550                         default:
1551                                 args->mount_server.version = NFS_MNT3_VERSION;
1552                                 break;
1553                         case 2:
1554                                 args->mount_server.version = NFS_MNT_VERSION;
1555                 }
1556         }
1557         request.version = args->mount_server.version;
1558
1559         if (args->mount_server.hostname)
1560                 request.hostname = args->mount_server.hostname;
1561         else
1562                 request.hostname = args->nfs_server.hostname;
1563
1564         /*
1565          * Construct the mount server's address.
1566          */
1567         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1568                 memcpy(request.sap, &args->nfs_server.address,
1569                        args->nfs_server.addrlen);
1570                 args->mount_server.addrlen = args->nfs_server.addrlen;
1571         }
1572         request.salen = args->mount_server.addrlen;
1573         nfs_set_port(request.sap, &args->mount_server.port, 0);
1574
1575         /*
1576          * Now ask the mount server to map our export path
1577          * to a file handle.
1578          */
1579         status = nfs_mount(&request);
1580         if (status != 0) {
1581                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1582                                 request.hostname, status);
1583                 return status;
1584         }
1585
1586         /*
1587          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1588          */
1589         if (args->mount_server.version != NFS_MNT3_VERSION)
1590                 return 0;
1591         return nfs_walk_authlist(args, &request);
1592 }
1593
1594 static int nfs_parse_simple_hostname(const char *dev_name,
1595                                      char **hostname, size_t maxnamlen,
1596                                      char **export_path, size_t maxpathlen)
1597 {
1598         size_t len;
1599         char *colon, *comma;
1600
1601         colon = strchr(dev_name, ':');
1602         if (colon == NULL)
1603                 goto out_bad_devname;
1604
1605         len = colon - dev_name;
1606         if (len > maxnamlen)
1607                 goto out_hostname;
1608
1609         /* N.B. caller will free nfs_server.hostname in all cases */
1610         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1611         if (!*hostname)
1612                 goto out_nomem;
1613
1614         /* kill possible hostname list: not supported */
1615         comma = strchr(*hostname, ',');
1616         if (comma != NULL) {
1617                 if (comma == *hostname)
1618                         goto out_bad_devname;
1619                 *comma = '\0';
1620         }
1621
1622         colon++;
1623         len = strlen(colon);
1624         if (len > maxpathlen)
1625                 goto out_path;
1626         *export_path = kstrndup(colon, len, GFP_KERNEL);
1627         if (!*export_path)
1628                 goto out_nomem;
1629
1630         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1631         return 0;
1632
1633 out_bad_devname:
1634         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1635         return -EINVAL;
1636
1637 out_nomem:
1638         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1639         return -ENOMEM;
1640
1641 out_hostname:
1642         dfprintk(MOUNT, "NFS: server hostname too long\n");
1643         return -ENAMETOOLONG;
1644
1645 out_path:
1646         dfprintk(MOUNT, "NFS: export pathname too long\n");
1647         return -ENAMETOOLONG;
1648 }
1649
1650 /*
1651  * Hostname has square brackets around it because it contains one or
1652  * more colons.  We look for the first closing square bracket, and a
1653  * colon must follow it.
1654  */
1655 static int nfs_parse_protected_hostname(const char *dev_name,
1656                                         char **hostname, size_t maxnamlen,
1657                                         char **export_path, size_t maxpathlen)
1658 {
1659         size_t len;
1660         char *start, *end;
1661
1662         start = (char *)(dev_name + 1);
1663
1664         end = strchr(start, ']');
1665         if (end == NULL)
1666                 goto out_bad_devname;
1667         if (*(end + 1) != ':')
1668                 goto out_bad_devname;
1669
1670         len = end - start;
1671         if (len > maxnamlen)
1672                 goto out_hostname;
1673
1674         /* N.B. caller will free nfs_server.hostname in all cases */
1675         *hostname = kstrndup(start, len, GFP_KERNEL);
1676         if (*hostname == NULL)
1677                 goto out_nomem;
1678
1679         end += 2;
1680         len = strlen(end);
1681         if (len > maxpathlen)
1682                 goto out_path;
1683         *export_path = kstrndup(end, len, GFP_KERNEL);
1684         if (!*export_path)
1685                 goto out_nomem;
1686
1687         return 0;
1688
1689 out_bad_devname:
1690         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1691         return -EINVAL;
1692
1693 out_nomem:
1694         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1695         return -ENOMEM;
1696
1697 out_hostname:
1698         dfprintk(MOUNT, "NFS: server hostname too long\n");
1699         return -ENAMETOOLONG;
1700
1701 out_path:
1702         dfprintk(MOUNT, "NFS: export pathname too long\n");
1703         return -ENAMETOOLONG;
1704 }
1705
1706 /*
1707  * Split "dev_name" into "hostname:export_path".
1708  *
1709  * The leftmost colon demarks the split between the server's hostname
1710  * and the export path.  If the hostname starts with a left square
1711  * bracket, then it may contain colons.
1712  *
1713  * Note: caller frees hostname and export path, even on error.
1714  */
1715 static int nfs_parse_devname(const char *dev_name,
1716                              char **hostname, size_t maxnamlen,
1717                              char **export_path, size_t maxpathlen)
1718 {
1719         if (*dev_name == '[')
1720                 return nfs_parse_protected_hostname(dev_name,
1721                                                     hostname, maxnamlen,
1722                                                     export_path, maxpathlen);
1723
1724         return nfs_parse_simple_hostname(dev_name,
1725                                          hostname, maxnamlen,
1726                                          export_path, maxpathlen);
1727 }
1728
1729 /*
1730  * Validate the NFS2/NFS3 mount data
1731  * - fills in the mount root filehandle
1732  *
1733  * For option strings, user space handles the following behaviors:
1734  *
1735  * + DNS: mapping server host name to IP address ("addr=" option)
1736  *
1737  * + failure mode: how to behave if a mount request can't be handled
1738  *   immediately ("fg/bg" option)
1739  *
1740  * + retry: how often to retry a mount request ("retry=" option)
1741  *
1742  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1743  *   mountproto=tcp after mountproto=udp, and so on
1744  */
1745 static int nfs_validate_mount_data(void *options,
1746                                    struct nfs_parsed_mount_data *args,
1747                                    struct nfs_fh *mntfh,
1748                                    const char *dev_name)
1749 {
1750         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1751         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1752
1753         if (data == NULL)
1754                 goto out_no_data;
1755
1756         switch (data->version) {
1757         case 1:
1758                 data->namlen = 0;
1759         case 2:
1760                 data->bsize = 0;
1761         case 3:
1762                 if (data->flags & NFS_MOUNT_VER3)
1763                         goto out_no_v3;
1764                 data->root.size = NFS2_FHSIZE;
1765                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1766         case 4:
1767                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1768                         goto out_no_sec;
1769         case 5:
1770                 memset(data->context, 0, sizeof(data->context));
1771         case 6:
1772                 if (data->flags & NFS_MOUNT_VER3) {
1773                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1774                                 goto out_invalid_fh;
1775                         mntfh->size = data->root.size;
1776                         args->version = 3;
1777                 } else {
1778                         mntfh->size = NFS2_FHSIZE;
1779                         args->version = 2;
1780                 }
1781
1782
1783                 memcpy(mntfh->data, data->root.data, mntfh->size);
1784                 if (mntfh->size < sizeof(mntfh->data))
1785                         memset(mntfh->data + mntfh->size, 0,
1786                                sizeof(mntfh->data) - mntfh->size);
1787
1788                 /*
1789                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1790                  * can deal with.
1791                  */
1792                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1793                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1794                 args->rsize             = data->rsize;
1795                 args->wsize             = data->wsize;
1796                 args->timeo             = data->timeo;
1797                 args->retrans           = data->retrans;
1798                 args->acregmin          = data->acregmin;
1799                 args->acregmax          = data->acregmax;
1800                 args->acdirmin          = data->acdirmin;
1801                 args->acdirmax          = data->acdirmax;
1802
1803                 memcpy(sap, &data->addr, sizeof(data->addr));
1804                 args->nfs_server.addrlen = sizeof(data->addr);
1805                 if (!nfs_verify_server_address(sap))
1806                         goto out_no_address;
1807
1808                 if (!(data->flags & NFS_MOUNT_TCP))
1809                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1810                 /* N.B. caller will free nfs_server.hostname in all cases */
1811                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1812                 args->namlen            = data->namlen;
1813                 args->bsize             = data->bsize;
1814
1815                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1816                         args->auth_flavors[0] = data->pseudoflavor;
1817                 if (!args->nfs_server.hostname)
1818                         goto out_nomem;
1819
1820                 /*
1821                  * The legacy version 6 binary mount data from userspace has a
1822                  * field used only to transport selinux information into the
1823                  * the kernel.  To continue to support that functionality we
1824                  * have a touch of selinux knowledge here in the NFS code. The
1825                  * userspace code converted context=blah to just blah so we are
1826                  * converting back to the full string selinux understands.
1827                  */
1828                 if (data->context[0]){
1829 #ifdef CONFIG_SECURITY_SELINUX
1830                         int rc;
1831                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1832                         if (!opts_str)
1833                                 return -ENOMEM;
1834                         strcpy(opts_str, "context=");
1835                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1836                         strcat(opts_str, &data->context[0]);
1837                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1838                         kfree(opts_str);
1839                         if (rc)
1840                                 return rc;
1841 #else
1842                         return -EINVAL;
1843 #endif
1844                 }
1845
1846                 break;
1847         default: {
1848                 int status;
1849
1850                 if (nfs_parse_mount_options((char *)options, args) == 0)
1851                         return -EINVAL;
1852
1853                 if (!nfs_verify_server_address(sap))
1854                         goto out_no_address;
1855
1856                 if (args->version == 4)
1857 #ifdef CONFIG_NFS_V4
1858                         return nfs4_validate_text_mount_data(options,
1859                                                              args, dev_name);
1860 #else
1861                         goto out_v4_not_compiled;
1862 #endif
1863
1864                 nfs_set_port(sap, &args->nfs_server.port, 0);
1865
1866                 nfs_set_mount_transport_protocol(args);
1867
1868                 status = nfs_parse_devname(dev_name,
1869                                            &args->nfs_server.hostname,
1870                                            PAGE_SIZE,
1871                                            &args->nfs_server.export_path,
1872                                            NFS_MAXPATHLEN);
1873                 if (!status)
1874                         status = nfs_try_mount(args, mntfh);
1875
1876                 kfree(args->nfs_server.export_path);
1877                 args->nfs_server.export_path = NULL;
1878
1879                 if (status)
1880                         return status;
1881
1882                 break;
1883                 }
1884         }
1885
1886 #ifndef CONFIG_NFS_V3
1887         if (args->version == 3)
1888                 goto out_v3_not_compiled;
1889 #endif /* !CONFIG_NFS_V3 */
1890
1891         return 0;
1892
1893 out_no_data:
1894         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1895         return -EINVAL;
1896
1897 out_no_v3:
1898         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1899                  data->version);
1900         return -EINVAL;
1901
1902 out_no_sec:
1903         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1904         return -EINVAL;
1905
1906 #ifndef CONFIG_NFS_V3
1907 out_v3_not_compiled:
1908         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1909         return -EPROTONOSUPPORT;
1910 #endif /* !CONFIG_NFS_V3 */
1911
1912 #ifndef CONFIG_NFS_V4
1913 out_v4_not_compiled:
1914         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1915         return -EPROTONOSUPPORT;
1916 #endif /* !CONFIG_NFS_V4 */
1917
1918 out_nomem:
1919         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1920         return -ENOMEM;
1921
1922 out_no_address:
1923         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1924         return -EINVAL;
1925
1926 out_invalid_fh:
1927         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1928         return -EINVAL;
1929 }
1930
1931 static int
1932 nfs_compare_remount_data(struct nfs_server *nfss,
1933                          struct nfs_parsed_mount_data *data)
1934 {
1935         if (data->flags != nfss->flags ||
1936             data->rsize != nfss->rsize ||
1937             data->wsize != nfss->wsize ||
1938             data->retrans != nfss->client->cl_timeout->to_retries ||
1939             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1940             data->acregmin != nfss->acregmin / HZ ||
1941             data->acregmax != nfss->acregmax / HZ ||
1942             data->acdirmin != nfss->acdirmin / HZ ||
1943             data->acdirmax != nfss->acdirmax / HZ ||
1944             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1945             data->nfs_server.port != nfss->port ||
1946             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1947             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1948                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
1949                 return -EINVAL;
1950
1951         return 0;
1952 }
1953
1954 static int
1955 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1956 {
1957         int error;
1958         struct nfs_server *nfss = sb->s_fs_info;
1959         struct nfs_parsed_mount_data *data;
1960         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1961         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1962         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1963
1964         /*
1965          * Userspace mount programs that send binary options generally send
1966          * them populated with default values. We have no way to know which
1967          * ones were explicitly specified. Fall back to legacy behavior and
1968          * just return success.
1969          */
1970         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1971             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1972                                            options->version <= 6))))
1973                 return 0;
1974
1975         data = kzalloc(sizeof(*data), GFP_KERNEL);
1976         if (data == NULL)
1977                 return -ENOMEM;
1978
1979         /* fill out struct with values from existing mount */
1980         data->flags = nfss->flags;
1981         data->rsize = nfss->rsize;
1982         data->wsize = nfss->wsize;
1983         data->retrans = nfss->client->cl_timeout->to_retries;
1984         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1985         data->acregmin = nfss->acregmin / HZ;
1986         data->acregmax = nfss->acregmax / HZ;
1987         data->acdirmin = nfss->acdirmin / HZ;
1988         data->acdirmax = nfss->acdirmax / HZ;
1989         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1990         data->nfs_server.port = nfss->port;
1991         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1992         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1993                 data->nfs_server.addrlen);
1994
1995         /* overwrite those values with any that were specified */
1996         error = nfs_parse_mount_options((char *)options, data);
1997         if (error < 0)
1998                 goto out;
1999
2000         /* compare new mount options with old ones */
2001         error = nfs_compare_remount_data(nfss, data);
2002 out:
2003         kfree(data);
2004         return error;
2005 }
2006
2007 /*
2008  * Initialise the common bits of the superblock
2009  */
2010 static inline void nfs_initialise_sb(struct super_block *sb)
2011 {
2012         struct nfs_server *server = NFS_SB(sb);
2013
2014         sb->s_magic = NFS_SUPER_MAGIC;
2015
2016         /* We probably want something more informative here */
2017         snprintf(sb->s_id, sizeof(sb->s_id),
2018                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2019
2020         if (sb->s_blocksize == 0)
2021                 sb->s_blocksize = nfs_block_bits(server->wsize,
2022                                                  &sb->s_blocksize_bits);
2023
2024         if (server->flags & NFS_MOUNT_NOAC)
2025                 sb->s_flags |= MS_SYNCHRONOUS;
2026
2027         sb->s_bdi = &server->backing_dev_info;
2028
2029         nfs_super_set_maxbytes(sb, server->maxfilesize);
2030 }
2031
2032 /*
2033  * Finish setting up an NFS2/3 superblock
2034  */
2035 static void nfs_fill_super(struct super_block *sb,
2036                            struct nfs_parsed_mount_data *data)
2037 {
2038         struct nfs_server *server = NFS_SB(sb);
2039
2040         sb->s_blocksize_bits = 0;
2041         sb->s_blocksize = 0;
2042         if (data->bsize)
2043                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2044
2045         if (server->nfs_client->rpc_ops->version == 3) {
2046                 /* The VFS shouldn't apply the umask to mode bits. We will do
2047                  * so ourselves when necessary.
2048                  */
2049                 sb->s_flags |= MS_POSIXACL;
2050                 sb->s_time_gran = 1;
2051         }
2052
2053         sb->s_op = &nfs_sops;
2054         nfs_initialise_sb(sb);
2055 }
2056
2057 /*
2058  * Finish setting up a cloned NFS2/3 superblock
2059  */
2060 static void nfs_clone_super(struct super_block *sb,
2061                             const struct super_block *old_sb)
2062 {
2063         struct nfs_server *server = NFS_SB(sb);
2064
2065         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2066         sb->s_blocksize = old_sb->s_blocksize;
2067         sb->s_maxbytes = old_sb->s_maxbytes;
2068
2069         if (server->nfs_client->rpc_ops->version == 3) {
2070                 /* The VFS shouldn't apply the umask to mode bits. We will do
2071                  * so ourselves when necessary.
2072                  */
2073                 sb->s_flags |= MS_POSIXACL;
2074                 sb->s_time_gran = 1;
2075         }
2076
2077         sb->s_op = old_sb->s_op;
2078         nfs_initialise_sb(sb);
2079 }
2080
2081 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2082 {
2083         const struct nfs_server *a = s->s_fs_info;
2084         const struct rpc_clnt *clnt_a = a->client;
2085         const struct rpc_clnt *clnt_b = b->client;
2086
2087         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2088                 goto Ebusy;
2089         if (a->nfs_client != b->nfs_client)
2090                 goto Ebusy;
2091         if (a->flags != b->flags)
2092                 goto Ebusy;
2093         if (a->wsize != b->wsize)
2094                 goto Ebusy;
2095         if (a->rsize != b->rsize)
2096                 goto Ebusy;
2097         if (a->acregmin != b->acregmin)
2098                 goto Ebusy;
2099         if (a->acregmax != b->acregmax)
2100                 goto Ebusy;
2101         if (a->acdirmin != b->acdirmin)
2102                 goto Ebusy;
2103         if (a->acdirmax != b->acdirmax)
2104                 goto Ebusy;
2105         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2106                 goto Ebusy;
2107         return 1;
2108 Ebusy:
2109         return 0;
2110 }
2111
2112 struct nfs_sb_mountdata {
2113         struct nfs_server *server;
2114         int mntflags;
2115 };
2116
2117 static int nfs_set_super(struct super_block *s, void *data)
2118 {
2119         struct nfs_sb_mountdata *sb_mntdata = data;
2120         struct nfs_server *server = sb_mntdata->server;
2121         int ret;
2122
2123         s->s_flags = sb_mntdata->mntflags;
2124         s->s_fs_info = server;
2125         ret = set_anon_super(s, server);
2126         if (ret == 0)
2127                 server->s_dev = s->s_dev;
2128         return ret;
2129 }
2130
2131 static int nfs_compare_super_address(struct nfs_server *server1,
2132                                      struct nfs_server *server2)
2133 {
2134         struct sockaddr *sap1, *sap2;
2135
2136         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2137         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2138
2139         if (sap1->sa_family != sap2->sa_family)
2140                 return 0;
2141
2142         switch (sap1->sa_family) {
2143         case AF_INET: {
2144                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2145                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2146                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2147                         return 0;
2148                 if (sin1->sin_port != sin2->sin_port)
2149                         return 0;
2150                 break;
2151         }
2152         case AF_INET6: {
2153                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2154                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2155                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2156                         return 0;
2157                 if (sin1->sin6_port != sin2->sin6_port)
2158                         return 0;
2159                 break;
2160         }
2161         default:
2162                 return 0;
2163         }
2164
2165         return 1;
2166 }
2167
2168 static int nfs_compare_super(struct super_block *sb, void *data)
2169 {
2170         struct nfs_sb_mountdata *sb_mntdata = data;
2171         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2172         int mntflags = sb_mntdata->mntflags;
2173
2174         if (!nfs_compare_super_address(old, server))
2175                 return 0;
2176         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2177         if (old->flags & NFS_MOUNT_UNSHARED)
2178                 return 0;
2179         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2180                 return 0;
2181         return nfs_compare_mount_options(sb, server, mntflags);
2182 }
2183
2184 static int nfs_bdi_register(struct nfs_server *server)
2185 {
2186         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2187 }
2188
2189 static int nfs_get_sb(struct file_system_type *fs_type,
2190         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2191 {
2192         struct nfs_server *server = NULL;
2193         struct super_block *s;
2194         struct nfs_parsed_mount_data *data;
2195         struct nfs_fh *mntfh;
2196         struct dentry *mntroot;
2197         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2198         struct nfs_sb_mountdata sb_mntdata = {
2199                 .mntflags = flags,
2200         };
2201         int error = -ENOMEM;
2202
2203         data = nfs_alloc_parsed_mount_data(3);
2204         mntfh = nfs_alloc_fhandle();
2205         if (data == NULL || mntfh == NULL)
2206                 goto out_free_fh;
2207
2208         security_init_mnt_opts(&data->lsm_opts);
2209
2210         /* Validate the mount data */
2211         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2212         if (error < 0)
2213                 goto out;
2214
2215 #ifdef CONFIG_NFS_V4
2216         if (data->version == 4) {
2217                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2218                 kfree(data->client_address);
2219                 kfree(data->nfs_server.export_path);
2220                 goto out;
2221         }
2222 #endif  /* CONFIG_NFS_V4 */
2223
2224         /* Get a volume representation */
2225         server = nfs_create_server(data, mntfh);
2226         if (IS_ERR(server)) {
2227                 error = PTR_ERR(server);
2228                 goto out;
2229         }
2230         sb_mntdata.server = server;
2231
2232         if (server->flags & NFS_MOUNT_UNSHARED)
2233                 compare_super = NULL;
2234
2235         /* Get a superblock - note that we may end up sharing one that already exists */
2236         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2237         if (IS_ERR(s)) {
2238                 error = PTR_ERR(s);
2239                 goto out_err_nosb;
2240         }
2241
2242         if (s->s_fs_info != server) {
2243                 nfs_free_server(server);
2244                 server = NULL;
2245         } else {
2246                 error = nfs_bdi_register(server);
2247                 if (error)
2248                         goto error_splat_bdi;
2249         }
2250
2251         if (!s->s_root) {
2252                 /* initial superblock/root creation */
2253                 nfs_fill_super(s, data);
2254                 nfs_fscache_get_super_cookie(
2255                         s, data ? data->fscache_uniq : NULL, NULL);
2256         }
2257
2258         mntroot = nfs_get_root(s, mntfh);
2259         if (IS_ERR(mntroot)) {
2260                 error = PTR_ERR(mntroot);
2261                 goto error_splat_super;
2262         }
2263
2264         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2265         if (error)
2266                 goto error_splat_root;
2267
2268         s->s_flags |= MS_ACTIVE;
2269         mnt->mnt_sb = s;
2270         mnt->mnt_root = mntroot;
2271         error = 0;
2272
2273 out:
2274         kfree(data->nfs_server.hostname);
2275         kfree(data->mount_server.hostname);
2276         kfree(data->fscache_uniq);
2277         security_free_mnt_opts(&data->lsm_opts);
2278 out_free_fh:
2279         nfs_free_fhandle(mntfh);
2280         kfree(data);
2281         return error;
2282
2283 out_err_nosb:
2284         nfs_free_server(server);
2285         goto out;
2286
2287 error_splat_root:
2288         dput(mntroot);
2289 error_splat_super:
2290         if (server && !s->s_root)
2291                 bdi_unregister(&server->backing_dev_info);
2292 error_splat_bdi:
2293         deactivate_locked_super(s);
2294         goto out;
2295 }
2296
2297 /*
2298  * Ensure that we unregister the bdi before kill_anon_super
2299  * releases the device name
2300  */
2301 static void nfs_put_super(struct super_block *s)
2302 {
2303         struct nfs_server *server = NFS_SB(s);
2304
2305         bdi_unregister(&server->backing_dev_info);
2306 }
2307
2308 /*
2309  * Destroy an NFS2/3 superblock
2310  */
2311 static void nfs_kill_super(struct super_block *s)
2312 {
2313         struct nfs_server *server = NFS_SB(s);
2314
2315         kill_anon_super(s);
2316         nfs_fscache_release_super_cookie(s);
2317         nfs_free_server(server);
2318 }
2319
2320 /*
2321  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2322  */
2323 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2324                            const char *dev_name, void *raw_data,
2325                            struct vfsmount *mnt)
2326 {
2327         struct nfs_clone_mount *data = raw_data;
2328         struct super_block *s;
2329         struct nfs_server *server;
2330         struct dentry *mntroot;
2331         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2332         struct nfs_sb_mountdata sb_mntdata = {
2333                 .mntflags = flags,
2334         };
2335         int error;
2336
2337         dprintk("--> nfs_xdev_get_sb()\n");
2338
2339         /* create a new volume representation */
2340         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2341         if (IS_ERR(server)) {
2342                 error = PTR_ERR(server);
2343                 goto out_err_noserver;
2344         }
2345         sb_mntdata.server = server;
2346
2347         if (server->flags & NFS_MOUNT_UNSHARED)
2348                 compare_super = NULL;
2349
2350         /* Get a superblock - note that we may end up sharing one that already exists */
2351         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2352         if (IS_ERR(s)) {
2353                 error = PTR_ERR(s);
2354                 goto out_err_nosb;
2355         }
2356
2357         if (s->s_fs_info != server) {
2358                 nfs_free_server(server);
2359                 server = NULL;
2360         } else {
2361                 error = nfs_bdi_register(server);
2362                 if (error)
2363                         goto error_splat_bdi;
2364         }
2365
2366         if (!s->s_root) {
2367                 /* initial superblock/root creation */
2368                 nfs_clone_super(s, data->sb);
2369                 nfs_fscache_get_super_cookie(s, NULL, data);
2370         }
2371
2372         mntroot = nfs_get_root(s, data->fh);
2373         if (IS_ERR(mntroot)) {
2374                 error = PTR_ERR(mntroot);
2375                 goto error_splat_super;
2376         }
2377         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2378                 dput(mntroot);
2379                 error = -ESTALE;
2380                 goto error_splat_super;
2381         }
2382
2383         s->s_flags |= MS_ACTIVE;
2384         mnt->mnt_sb = s;
2385         mnt->mnt_root = mntroot;
2386
2387         /* clone any lsm security options from the parent to the new sb */
2388         security_sb_clone_mnt_opts(data->sb, s);
2389
2390         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2391         return 0;
2392
2393 out_err_nosb:
2394         nfs_free_server(server);
2395 out_err_noserver:
2396         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2397         return error;
2398
2399 error_splat_super:
2400         if (server && !s->s_root)
2401                 bdi_unregister(&server->backing_dev_info);
2402 error_splat_bdi:
2403         deactivate_locked_super(s);
2404         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2405         return error;
2406 }
2407
2408 #ifdef CONFIG_NFS_V4
2409
2410 /*
2411  * Finish setting up a cloned NFS4 superblock
2412  */
2413 static void nfs4_clone_super(struct super_block *sb,
2414                             const struct super_block *old_sb)
2415 {
2416         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2417         sb->s_blocksize = old_sb->s_blocksize;
2418         sb->s_maxbytes = old_sb->s_maxbytes;
2419         sb->s_time_gran = 1;
2420         sb->s_op = old_sb->s_op;
2421         nfs_initialise_sb(sb);
2422 }
2423
2424 /*
2425  * Set up an NFS4 superblock
2426  */
2427 static void nfs4_fill_super(struct super_block *sb)
2428 {
2429         sb->s_time_gran = 1;
2430         sb->s_op = &nfs4_sops;
2431         nfs_initialise_sb(sb);
2432 }
2433
2434 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2435 {
2436         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2437 }
2438
2439 static int nfs4_validate_text_mount_data(void *options,
2440                                          struct nfs_parsed_mount_data *args,
2441                                          const char *dev_name)
2442 {
2443         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2444
2445         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2446
2447         nfs_validate_transport_protocol(args);
2448
2449         nfs4_validate_mount_flags(args);
2450
2451         if (args->version != 4) {
2452                 dfprintk(MOUNT,
2453                          "NFS4: Illegal mount version\n");
2454                 return -EINVAL;
2455         }
2456
2457         if (args->auth_flavor_len > 1) {
2458                 dfprintk(MOUNT,
2459                          "NFS4: Too many RPC auth flavours specified\n");
2460                 return -EINVAL;
2461         }
2462
2463         if (args->client_address == NULL) {
2464                 dfprintk(MOUNT,
2465                          "NFS4: mount program didn't pass callback address\n");
2466                 return -EINVAL;
2467         }
2468
2469         return nfs_parse_devname(dev_name,
2470                                    &args->nfs_server.hostname,
2471                                    NFS4_MAXNAMLEN,
2472                                    &args->nfs_server.export_path,
2473                                    NFS4_MAXPATHLEN);
2474 }
2475
2476 /*
2477  * Validate NFSv4 mount options
2478  */
2479 static int nfs4_validate_mount_data(void *options,
2480                                     struct nfs_parsed_mount_data *args,
2481                                     const char *dev_name)
2482 {
2483         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2484         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2485         char *c;
2486
2487         if (data == NULL)
2488                 goto out_no_data;
2489
2490         switch (data->version) {
2491         case 1:
2492                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2493                         goto out_no_address;
2494                 if (data->host_addrlen == 0)
2495                         goto out_no_address;
2496                 args->nfs_server.addrlen = data->host_addrlen;
2497                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2498                         return -EFAULT;
2499                 if (!nfs_verify_server_address(sap))
2500                         goto out_no_address;
2501
2502                 if (data->auth_flavourlen) {
2503                         if (data->auth_flavourlen > 1)
2504                                 goto out_inval_auth;
2505                         if (copy_from_user(&args->auth_flavors[0],
2506                                            data->auth_flavours,
2507                                            sizeof(args->auth_flavors[0])))
2508                                 return -EFAULT;
2509                 }
2510
2511                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2512                 if (IS_ERR(c))
2513                         return PTR_ERR(c);
2514                 args->nfs_server.hostname = c;
2515
2516                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2517                 if (IS_ERR(c))
2518                         return PTR_ERR(c);
2519                 args->nfs_server.export_path = c;
2520                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2521
2522                 c = strndup_user(data->client_addr.data, 16);
2523                 if (IS_ERR(c))
2524                         return PTR_ERR(c);
2525                 args->client_address = c;
2526
2527                 /*
2528                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2529                  * can deal with.
2530                  */
2531
2532                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2533                 args->rsize     = data->rsize;
2534                 args->wsize     = data->wsize;
2535                 args->timeo     = data->timeo;
2536                 args->retrans   = data->retrans;
2537                 args->acregmin  = data->acregmin;
2538                 args->acregmax  = data->acregmax;
2539                 args->acdirmin  = data->acdirmin;
2540                 args->acdirmax  = data->acdirmax;
2541                 args->nfs_server.protocol = data->proto;
2542                 nfs_validate_transport_protocol(args);
2543
2544                 break;
2545         default:
2546                 if (nfs_parse_mount_options((char *)options, args) == 0)
2547                         return -EINVAL;
2548
2549                 if (!nfs_verify_server_address(sap))
2550                         return -EINVAL;
2551
2552                 return nfs4_validate_text_mount_data(options, args, dev_name);
2553         }
2554
2555         return 0;
2556
2557 out_no_data:
2558         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2559         return -EINVAL;
2560
2561 out_inval_auth:
2562         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2563                  data->auth_flavourlen);
2564         return -EINVAL;
2565
2566 out_no_address:
2567         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2568         return -EINVAL;
2569 }
2570
2571 /*
2572  * Get the superblock for the NFS4 root partition
2573  */
2574 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2575         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2576 {
2577         struct nfs_parsed_mount_data *data = raw_data;
2578         struct super_block *s;
2579         struct nfs_server *server;
2580         struct nfs_fh *mntfh;
2581         struct dentry *mntroot;
2582         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2583         struct nfs_sb_mountdata sb_mntdata = {
2584                 .mntflags = flags,
2585         };
2586         int error = -ENOMEM;
2587
2588         mntfh = nfs_alloc_fhandle();
2589         if (data == NULL || mntfh == NULL)
2590                 goto out_free_fh;
2591
2592         security_init_mnt_opts(&data->lsm_opts);
2593
2594         /* Get a volume representation */
2595         server = nfs4_create_server(data, mntfh);
2596         if (IS_ERR(server)) {
2597                 error = PTR_ERR(server);
2598                 goto out;
2599         }
2600         sb_mntdata.server = server;
2601
2602         if (server->flags & NFS4_MOUNT_UNSHARED)
2603                 compare_super = NULL;
2604
2605         /* Get a superblock - note that we may end up sharing one that already exists */
2606         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2607         if (IS_ERR(s)) {
2608                 error = PTR_ERR(s);
2609                 goto out_free;
2610         }
2611
2612         if (s->s_fs_info != server) {
2613                 nfs_free_server(server);
2614                 server = NULL;
2615         } else {
2616                 error = nfs_bdi_register(server);
2617                 if (error)
2618                         goto error_splat_bdi;
2619         }
2620
2621         if (!s->s_root) {
2622                 /* initial superblock/root creation */
2623                 nfs4_fill_super(s);
2624                 nfs_fscache_get_super_cookie(
2625                         s, data ? data->fscache_uniq : NULL, NULL);
2626         }
2627
2628         mntroot = nfs4_get_root(s, mntfh);
2629         if (IS_ERR(mntroot)) {
2630                 error = PTR_ERR(mntroot);
2631                 goto error_splat_super;
2632         }
2633
2634         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2635         if (error)
2636                 goto error_splat_root;
2637
2638         s->s_flags |= MS_ACTIVE;
2639         mnt->mnt_sb = s;
2640         mnt->mnt_root = mntroot;
2641         error = 0;
2642
2643 out:
2644         security_free_mnt_opts(&data->lsm_opts);
2645 out_free_fh:
2646         nfs_free_fhandle(mntfh);
2647         return error;
2648
2649 out_free:
2650         nfs_free_server(server);
2651         goto out;
2652
2653 error_splat_root:
2654         dput(mntroot);
2655 error_splat_super:
2656         if (server && !s->s_root)
2657                 bdi_unregister(&server->backing_dev_info);
2658 error_splat_bdi:
2659         deactivate_locked_super(s);
2660         goto out;
2661 }
2662
2663 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2664                 int flags, void *data, const char *hostname)
2665 {
2666         struct vfsmount *root_mnt;
2667         char *root_devname;
2668         size_t len;
2669
2670         len = strlen(hostname) + 3;
2671         root_devname = kmalloc(len, GFP_KERNEL);
2672         if (root_devname == NULL)
2673                 return ERR_PTR(-ENOMEM);
2674         snprintf(root_devname, len, "%s:/", hostname);
2675         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2676         kfree(root_devname);
2677         return root_mnt;
2678 }
2679
2680 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2681 {
2682         char *page = (char *) __get_free_page(GFP_KERNEL);
2683         char *devname, *tmp;
2684
2685         if (page == NULL)
2686                 return;
2687         devname = nfs_path(path->mnt->mnt_devname,
2688                         path->mnt->mnt_root, path->dentry,
2689                         page, PAGE_SIZE);
2690         if (IS_ERR(devname))
2691                 goto out_freepage;
2692         tmp = kstrdup(devname, GFP_KERNEL);
2693         if (tmp == NULL)
2694                 goto out_freepage;
2695         kfree(mnt->mnt_devname);
2696         mnt->mnt_devname = tmp;
2697 out_freepage:
2698         free_page((unsigned long)page);
2699 }
2700
2701 struct nfs_referral_count {
2702         struct list_head list;
2703         const struct task_struct *task;
2704         unsigned int referral_count;
2705 };
2706
2707 static LIST_HEAD(nfs_referral_count_list);
2708 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2709
2710 static struct nfs_referral_count *nfs_find_referral_count(void)
2711 {
2712         struct nfs_referral_count *p;
2713
2714         list_for_each_entry(p, &nfs_referral_count_list, list) {
2715                 if (p->task == current)
2716                         return p;
2717         }
2718         return NULL;
2719 }
2720
2721 #define NFS_MAX_NESTED_REFERRALS 2
2722
2723 static int nfs_referral_loop_protect(void)
2724 {
2725         struct nfs_referral_count *p, *new;
2726         int ret = -ENOMEM;
2727
2728         new = kmalloc(sizeof(*new), GFP_KERNEL);
2729         if (!new)
2730                 goto out;
2731         new->task = current;
2732         new->referral_count = 1;
2733
2734         ret = 0;
2735         spin_lock(&nfs_referral_count_list_lock);
2736         p = nfs_find_referral_count();
2737         if (p != NULL) {
2738                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2739                         ret = -ELOOP;
2740                 else
2741                         p->referral_count++;
2742         } else {
2743                 list_add(&new->list, &nfs_referral_count_list);
2744                 new = NULL;
2745         }
2746         spin_unlock(&nfs_referral_count_list_lock);
2747         kfree(new);
2748 out:
2749         return ret;
2750 }
2751
2752 static void nfs_referral_loop_unprotect(void)
2753 {
2754         struct nfs_referral_count *p;
2755
2756         spin_lock(&nfs_referral_count_list_lock);
2757         p = nfs_find_referral_count();
2758         p->referral_count--;
2759         if (p->referral_count == 0)
2760                 list_del(&p->list);
2761         else
2762                 p = NULL;
2763         spin_unlock(&nfs_referral_count_list_lock);
2764         kfree(p);
2765 }
2766
2767 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2768                 const char *export_path, struct vfsmount *mnt_target)
2769 {
2770         struct nameidata *nd = NULL;
2771         struct mnt_namespace *ns_private;
2772         struct super_block *s;
2773         int ret;
2774
2775         nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2776         if (nd == NULL)
2777                 return -ENOMEM;
2778
2779         ns_private = create_mnt_ns(root_mnt);
2780         ret = PTR_ERR(ns_private);
2781         if (IS_ERR(ns_private))
2782                 goto out_mntput;
2783
2784         ret = nfs_referral_loop_protect();
2785         if (ret != 0)
2786                 goto out_put_mnt_ns;
2787
2788         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2789                         export_path, LOOKUP_FOLLOW, nd);
2790
2791         nfs_referral_loop_unprotect();
2792         put_mnt_ns(ns_private);
2793
2794         if (ret != 0)
2795                 goto out_err;
2796
2797         s = nd->path.mnt->mnt_sb;
2798         atomic_inc(&s->s_active);
2799         mnt_target->mnt_sb = s;
2800         mnt_target->mnt_root = dget(nd->path.dentry);
2801
2802         /* Correct the device pathname */
2803         nfs_fix_devname(&nd->path, mnt_target);
2804
2805         path_put(&nd->path);
2806         kfree(nd);
2807         down_write(&s->s_umount);
2808         return 0;
2809 out_put_mnt_ns:
2810         put_mnt_ns(ns_private);
2811 out_mntput:
2812         mntput(root_mnt);
2813 out_err:
2814         kfree(nd);
2815         return ret;
2816 }
2817
2818 static int nfs4_try_mount(int flags, const char *dev_name,
2819                          struct nfs_parsed_mount_data *data,
2820                          struct vfsmount *mnt)
2821 {
2822         char *export_path;
2823         struct vfsmount *root_mnt;
2824         int error;
2825
2826         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2827
2828         export_path = data->nfs_server.export_path;
2829         data->nfs_server.export_path = "/";
2830         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2831                         data->nfs_server.hostname);
2832         data->nfs_server.export_path = export_path;
2833
2834         error = PTR_ERR(root_mnt);
2835         if (IS_ERR(root_mnt))
2836                 goto out;
2837
2838         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2839
2840 out:
2841         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2842                         error != 0 ? " [error]" : "");
2843         return error;
2844 }
2845
2846 /*
2847  * Get the superblock for an NFS4 mountpoint
2848  */
2849 static int nfs4_get_sb(struct file_system_type *fs_type,
2850         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2851 {
2852         struct nfs_parsed_mount_data *data;
2853         int error = -ENOMEM;
2854
2855         data = nfs_alloc_parsed_mount_data(4);
2856         if (data == NULL)
2857                 goto out_free_data;
2858
2859         /* Validate the mount data */
2860         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2861         if (error < 0)
2862                 goto out;
2863
2864         error = nfs4_try_mount(flags, dev_name, data, mnt);
2865
2866 out:
2867         kfree(data->client_address);
2868         kfree(data->nfs_server.export_path);
2869         kfree(data->nfs_server.hostname);
2870         kfree(data->fscache_uniq);
2871 out_free_data:
2872         kfree(data);
2873         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2874                         error != 0 ? " [error]" : "");
2875         return error;
2876 }
2877
2878 static void nfs4_kill_super(struct super_block *sb)
2879 {
2880         struct nfs_server *server = NFS_SB(sb);
2881
2882         dprintk("--> %s\n", __func__);
2883         nfs_super_return_all_delegations(sb);
2884         kill_anon_super(sb);
2885         nfs_fscache_release_super_cookie(sb);
2886         nfs_free_server(server);
2887         dprintk("<-- %s\n", __func__);
2888 }
2889
2890 /*
2891  * Clone an NFS4 server record on xdev traversal (FSID-change)
2892  */
2893 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2894                             const char *dev_name, void *raw_data,
2895                             struct vfsmount *mnt)
2896 {
2897         struct nfs_clone_mount *data = raw_data;
2898         struct super_block *s;
2899         struct nfs_server *server;
2900         struct dentry *mntroot;
2901         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2902         struct nfs_sb_mountdata sb_mntdata = {
2903                 .mntflags = flags,
2904         };
2905         int error;
2906
2907         dprintk("--> nfs4_xdev_get_sb()\n");
2908
2909         /* create a new volume representation */
2910         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2911         if (IS_ERR(server)) {
2912                 error = PTR_ERR(server);
2913                 goto out_err_noserver;
2914         }
2915         sb_mntdata.server = server;
2916
2917         if (server->flags & NFS4_MOUNT_UNSHARED)
2918                 compare_super = NULL;
2919
2920         /* Get a superblock - note that we may end up sharing one that already exists */
2921         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2922         if (IS_ERR(s)) {
2923                 error = PTR_ERR(s);
2924                 goto out_err_nosb;
2925         }
2926
2927         if (s->s_fs_info != server) {
2928                 nfs_free_server(server);
2929                 server = NULL;
2930         } else {
2931                 error = nfs_bdi_register(server);
2932                 if (error)
2933                         goto error_splat_bdi;
2934         }
2935
2936         if (!s->s_root) {
2937                 /* initial superblock/root creation */
2938                 nfs4_clone_super(s, data->sb);
2939                 nfs_fscache_get_super_cookie(s, NULL, data);
2940         }
2941
2942         mntroot = nfs4_get_root(s, data->fh);
2943         if (IS_ERR(mntroot)) {
2944                 error = PTR_ERR(mntroot);
2945                 goto error_splat_super;
2946         }
2947         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2948                 dput(mntroot);
2949                 error = -ESTALE;
2950                 goto error_splat_super;
2951         }
2952
2953         s->s_flags |= MS_ACTIVE;
2954         mnt->mnt_sb = s;
2955         mnt->mnt_root = mntroot;
2956
2957         security_sb_clone_mnt_opts(data->sb, s);
2958
2959         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2960         return 0;
2961
2962 out_err_nosb:
2963         nfs_free_server(server);
2964 out_err_noserver:
2965         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2966         return error;
2967
2968 error_splat_super:
2969         if (server && !s->s_root)
2970                 bdi_unregister(&server->backing_dev_info);
2971 error_splat_bdi:
2972         deactivate_locked_super(s);
2973         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2974         return error;
2975 }
2976
2977 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2978                 int flags, const char *dev_name, void *raw_data,
2979                 struct vfsmount *mnt)
2980 {
2981         struct nfs_clone_mount *data = raw_data;
2982         struct super_block *s;
2983         struct nfs_server *server;
2984         struct dentry *mntroot;
2985         struct nfs_fh *mntfh;
2986         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2987         struct nfs_sb_mountdata sb_mntdata = {
2988                 .mntflags = flags,
2989         };
2990         int error = -ENOMEM;
2991
2992         dprintk("--> nfs4_referral_get_sb()\n");
2993
2994         mntfh = nfs_alloc_fhandle();
2995         if (mntfh == NULL)
2996                 goto out_err_nofh;
2997
2998         /* create a new volume representation */
2999         server = nfs4_create_referral_server(data, mntfh);
3000         if (IS_ERR(server)) {
3001                 error = PTR_ERR(server);
3002                 goto out_err_noserver;
3003         }
3004         sb_mntdata.server = server;
3005
3006         if (server->flags & NFS4_MOUNT_UNSHARED)
3007                 compare_super = NULL;
3008
3009         /* Get a superblock - note that we may end up sharing one that already exists */
3010         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3011         if (IS_ERR(s)) {
3012                 error = PTR_ERR(s);
3013                 goto out_err_nosb;
3014         }
3015
3016         if (s->s_fs_info != server) {
3017                 nfs_free_server(server);
3018                 server = NULL;
3019         } else {
3020                 error = nfs_bdi_register(server);
3021                 if (error)
3022                         goto error_splat_bdi;
3023         }
3024
3025         if (!s->s_root) {
3026                 /* initial superblock/root creation */
3027                 nfs4_fill_super(s);
3028                 nfs_fscache_get_super_cookie(s, NULL, data);
3029         }
3030
3031         mntroot = nfs4_get_root(s, mntfh);
3032         if (IS_ERR(mntroot)) {
3033                 error = PTR_ERR(mntroot);
3034                 goto error_splat_super;
3035         }
3036         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3037                 dput(mntroot);
3038                 error = -ESTALE;
3039                 goto error_splat_super;
3040         }
3041
3042         s->s_flags |= MS_ACTIVE;
3043         mnt->mnt_sb = s;
3044         mnt->mnt_root = mntroot;
3045
3046         security_sb_clone_mnt_opts(data->sb, s);
3047
3048         nfs_free_fhandle(mntfh);
3049         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3050         return 0;
3051
3052 out_err_nosb:
3053         nfs_free_server(server);
3054 out_err_noserver:
3055         nfs_free_fhandle(mntfh);
3056 out_err_nofh:
3057         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3058         return error;
3059
3060 error_splat_super:
3061         if (server && !s->s_root)
3062                 bdi_unregister(&server->backing_dev_info);
3063 error_splat_bdi:
3064         deactivate_locked_super(s);
3065         nfs_free_fhandle(mntfh);
3066         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3067         return error;
3068 }
3069
3070 /*
3071  * Create an NFS4 server record on referral traversal
3072  */
3073 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
3074                 int flags, const char *dev_name, void *raw_data,
3075                 struct vfsmount *mnt)
3076 {
3077         struct nfs_clone_mount *data = raw_data;
3078         char *export_path;
3079         struct vfsmount *root_mnt;
3080         int error;
3081
3082         dprintk("--> nfs4_referral_get_sb()\n");
3083
3084         export_path = data->mnt_path;
3085         data->mnt_path = "/";
3086
3087         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3088                         flags, data, data->hostname);
3089         data->mnt_path = export_path;
3090
3091         error = PTR_ERR(root_mnt);
3092         if (IS_ERR(root_mnt))
3093                 goto out;
3094
3095         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
3096 out:
3097         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
3098                         error != 0 ? " [error]" : "");
3099         return error;
3100 }
3101
3102 #endif /* CONFIG_NFS_V4 */