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/seq_file.h>
  43 #include <linux/mount.h>
  44 #include <linux/mnt_namespace.h>
  45 #include <linux/namei.h>
  46 #include <linux/nfs_idmap.h>
  47 #include <linux/vfs.h>
  48 #include <linux/inet.h>
  49 #include <linux/in6.h>
  50 #include <linux/slab.h>
  51 #include <net/ipv6.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/nfs_xdr.h>
  54 #include <linux/magic.h>
  55 #include <linux/parser.h>
  56
  57 #include <asm/system.h>
  58 #include <asm/uaccess.h>
  59
  60 #include "nfs4_fs.h"
  61 #include "callback.h"
  62 #include "delegation.h"
  63 #include "iostat.h"
  64 #include "internal.h"
  65 #include "fscache.h"
  66
  67 #define NFSDBG_FACILITY         NFSDBG_VFS
  68
  69 #ifdef CONFIG_NFS_V3
  70 #define NFS_DEFAULT_VERSION 3
  71 #else
  72 #define NFS_DEFAULT_VERSION 2
  73 #endif
  74
  75 enum {
  76         /* Mount options that take no arguments */
  77         Opt_soft, Opt_hard,
  78         Opt_posix, Opt_noposix,
  79         Opt_cto, Opt_nocto,
  80         Opt_ac, Opt_noac,
  81         Opt_lock, Opt_nolock,
  82         Opt_v2, Opt_v3, Opt_v4,
  83         Opt_udp, Opt_tcp, Opt_rdma,
  84         Opt_acl, Opt_noacl,
  85         Opt_rdirplus, Opt_nordirplus,
  86         Opt_sharecache, Opt_nosharecache,
  87         Opt_resvport, Opt_noresvport,
  88         Opt_fscache, Opt_nofscache,
  89
  90         /* Mount options that take integer arguments */
  91         Opt_port,
  92         Opt_rsize, Opt_wsize, Opt_bsize,
  93         Opt_timeo, Opt_retrans,
  94         Opt_acregmin, Opt_acregmax,
  95         Opt_acdirmin, Opt_acdirmax,
  96         Opt_actimeo,
  97         Opt_namelen,
  98         Opt_mountport,
  99         Opt_mountvers,
 100         Opt_nfsvers,
 101         Opt_minorversion,
 102
 103         /* Mount options that take string arguments */
 104         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 105         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 106         Opt_lookupcache,
 107         Opt_fscache_uniq,
 108         Opt_local_lock,
 109
 110         /* Special mount options */
 111         Opt_userspace, Opt_deprecated, Opt_sloppy,
 112
 113         Opt_err
 114 };
 115
 116 static const match_table_t nfs_mount_option_tokens = {
 117         { Opt_userspace, "bg" },
 118         { Opt_userspace, "fg" },
 119         { Opt_userspace, "retry=%s" },
 120
 121         { Opt_sloppy, "sloppy" },
 122
 123         { Opt_soft, "soft" },
 124         { Opt_hard, "hard" },
 125         { Opt_deprecated, "intr" },
 126         { Opt_deprecated, "nointr" },
 127         { Opt_posix, "posix" },
 128         { Opt_noposix, "noposix" },
 129         { Opt_cto, "cto" },
 130         { Opt_nocto, "nocto" },
 131         { Opt_ac, "ac" },
 132         { Opt_noac, "noac" },
 133         { Opt_lock, "lock" },
 134         { Opt_nolock, "nolock" },
 135         { Opt_v2, "v2" },
 136         { Opt_v3, "v3" },
 137         { Opt_v4, "v4" },
 138         { Opt_udp, "udp" },
 139         { Opt_tcp, "tcp" },
 140         { Opt_rdma, "rdma" },
 141         { Opt_acl, "acl" },
 142         { Opt_noacl, "noacl" },
 143         { Opt_rdirplus, "rdirplus" },
 144         { Opt_nordirplus, "nordirplus" },
 145         { Opt_sharecache, "sharecache" },
 146         { Opt_nosharecache, "nosharecache" },
 147         { Opt_resvport, "resvport" },
 148         { Opt_noresvport, "noresvport" },
 149         { Opt_fscache, "fsc" },
 150         { Opt_nofscache, "nofsc" },
 151
 152         { Opt_port, "port=%s" },
 153         { Opt_rsize, "rsize=%s" },
 154         { Opt_wsize, "wsize=%s" },
 155         { Opt_bsize, "bsize=%s" },
 156         { Opt_timeo, "timeo=%s" },
 157         { Opt_retrans, "retrans=%s" },
 158         { Opt_acregmin, "acregmin=%s" },
 159         { Opt_acregmax, "acregmax=%s" },
 160         { Opt_acdirmin, "acdirmin=%s" },
 161         { Opt_acdirmax, "acdirmax=%s" },
 162         { Opt_actimeo, "actimeo=%s" },
 163         { Opt_namelen, "namlen=%s" },
 164         { Opt_mountport, "mountport=%s" },
 165         { Opt_mountvers, "mountvers=%s" },
 166         { Opt_nfsvers, "nfsvers=%s" },
 167         { Opt_nfsvers, "vers=%s" },
 168         { Opt_minorversion, "minorversion=%s" },
 169
 170         { Opt_sec, "sec=%s" },
 171         { Opt_proto, "proto=%s" },
 172         { Opt_mountproto, "mountproto=%s" },
 173         { Opt_addr, "addr=%s" },
 174         { Opt_clientaddr, "clientaddr=%s" },
 175         { Opt_mounthost, "mounthost=%s" },
 176         { Opt_mountaddr, "mountaddr=%s" },
 177
 178         { Opt_lookupcache, "lookupcache=%s" },
 179         { Opt_fscache_uniq, "fsc=%s" },
 180         { Opt_local_lock, "local_lock=%s" },
 181
 182         { Opt_err, NULL }
 183 };
 184
 185 enum {
 186         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 187
 188         Opt_xprt_err
 189 };
 190
 191 static const match_table_t nfs_xprt_protocol_tokens = {
 192         { Opt_xprt_udp, "udp" },
 193         { Opt_xprt_udp6, "udp6" },
 194         { Opt_xprt_tcp, "tcp" },
 195         { Opt_xprt_tcp6, "tcp6" },
 196         { Opt_xprt_rdma, "rdma" },
 197
 198         { Opt_xprt_err, NULL }
 199 };
 200
 201 enum {
 202         Opt_sec_none, Opt_sec_sys,
 203         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 204         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 205         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 206
 207         Opt_sec_err
 208 };
 209
 210 static const match_table_t nfs_secflavor_tokens = {
 211         { Opt_sec_none, "none" },
 212         { Opt_sec_none, "null" },
 213         { Opt_sec_sys, "sys" },
 214
 215         { Opt_sec_krb5, "krb5" },
 216         { Opt_sec_krb5i, "krb5i" },
 217         { Opt_sec_krb5p, "krb5p" },
 218
 219         { Opt_sec_lkey, "lkey" },
 220         { Opt_sec_lkeyi, "lkeyi" },
 221         { Opt_sec_lkeyp, "lkeyp" },
 222
 223         { Opt_sec_spkm, "spkm3" },
 224         { Opt_sec_spkmi, "spkm3i" },
 225         { Opt_sec_spkmp, "spkm3p" },
 226
 227         { Opt_sec_err, NULL }
 228 };
 229
 230 enum {
 231         Opt_lookupcache_all, Opt_lookupcache_positive,
 232         Opt_lookupcache_none,
 233
 234         Opt_lookupcache_err
 235 };
 236
 237 static match_table_t nfs_lookupcache_tokens = {
 238         { Opt_lookupcache_all, "all" },
 239         { Opt_lookupcache_positive, "pos" },
 240         { Opt_lookupcache_positive, "positive" },
 241         { Opt_lookupcache_none, "none" },
 242
 243         { Opt_lookupcache_err, NULL }
 244 };
 245
 246 enum {
 247         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 248         Opt_local_lock_none,
 249
 250         Opt_local_lock_err
 251 };
 252
 253 static match_table_t nfs_local_lock_tokens = {
 254         { Opt_local_lock_all, "all" },
 255         { Opt_local_lock_flock, "flock" },
 256         { Opt_local_lock_posix, "posix" },
 257         { Opt_local_lock_none, "none" },
 258
 259         { Opt_local_lock_err, NULL }
 260 };
 261
 262
 263 static void nfs_umount_begin(struct super_block *);
 264 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 265 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 266 static int  nfs_show_devname(struct seq_file *, struct vfsmount *);
 267 static int  nfs_show_path(struct seq_file *, struct vfsmount *);
 268 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 269 static struct dentry *nfs_fs_mount(struct file_system_type *,
 270                 int, const char *, void *);
 271 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 272                 int flags, const char *dev_name, void *raw_data);
 273 static void nfs_put_super(struct super_block *);
 274 static void nfs_kill_super(struct super_block *);
 275 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 276
 277 static struct file_system_type nfs_fs_type = {
 278         .owner          = THIS_MODULE,
 279         .name           = "nfs",
 280         .mount          = nfs_fs_mount,
 281         .kill_sb        = nfs_kill_super,
 282         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 283 };
 284
 285 struct file_system_type nfs_xdev_fs_type = {
 286         .owner          = THIS_MODULE,
 287         .name           = "nfs",
 288         .mount          = nfs_xdev_mount,
 289         .kill_sb        = nfs_kill_super,
 290         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 291 };
 292
 293 static const struct super_operations nfs_sops = {
 294         .alloc_inode    = nfs_alloc_inode,
 295         .destroy_inode  = nfs_destroy_inode,
 296         .write_inode    = nfs_write_inode,
 297         .put_super      = nfs_put_super,
 298         .statfs         = nfs_statfs,
 299         .evict_inode    = nfs_evict_inode,
 300         .umount_begin   = nfs_umount_begin,
 301         .show_options   = nfs_show_options,
 302         .show_devname   = nfs_show_devname,
 303         .show_path      = nfs_show_path,
 304         .show_stats     = nfs_show_stats,
 305         .remount_fs     = nfs_remount,
 306 };
 307
 308 #ifdef CONFIG_NFS_V4
 309 static int nfs4_validate_text_mount_data(void *options,
 310         struct nfs_parsed_mount_data *args, const char *dev_name);
 311 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 312         struct nfs_parsed_mount_data *data);
 313 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
 314         int flags, const char *dev_name, void *raw_data);
 315 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 316         int flags, const char *dev_name, void *raw_data);
 317 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
 318         int flags, const char *dev_name, void *raw_data);
 319 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 320         int flags, const char *dev_name, void *raw_data);
 321 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 322         int flags, const char *dev_name, void *raw_data);
 323 static void nfs4_kill_super(struct super_block *sb);
 324
 325 static struct file_system_type nfs4_fs_type = {
 326         .owner          = THIS_MODULE,
 327         .name           = "nfs4",
 328         .mount          = nfs4_mount,
 329         .kill_sb        = nfs4_kill_super,
 330         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 331 };
 332
 333 static struct file_system_type nfs4_remote_fs_type = {
 334         .owner          = THIS_MODULE,
 335         .name           = "nfs4",
 336         .mount          = nfs4_remote_mount,
 337         .kill_sb        = nfs4_kill_super,
 338         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 339 };
 340
 341 struct file_system_type nfs4_xdev_fs_type = {
 342         .owner          = THIS_MODULE,
 343         .name           = "nfs4",
 344         .mount          = nfs4_xdev_mount,
 345         .kill_sb        = nfs4_kill_super,
 346         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 347 };
 348
 349 static struct file_system_type nfs4_remote_referral_fs_type = {
 350         .owner          = THIS_MODULE,
 351         .name           = "nfs4",
 352         .mount          = nfs4_remote_referral_mount,
 353         .kill_sb        = nfs4_kill_super,
 354         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 355 };
 356
 357 struct file_system_type nfs4_referral_fs_type = {
 358         .owner          = THIS_MODULE,
 359         .name           = "nfs4",
 360         .mount          = nfs4_referral_mount,
 361         .kill_sb        = nfs4_kill_super,
 362         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 363 };
 364
 365 static const struct super_operations nfs4_sops = {
 366         .alloc_inode    = nfs_alloc_inode,
 367         .destroy_inode  = nfs_destroy_inode,
 368         .write_inode    = nfs_write_inode,
 369         .put_super      = nfs_put_super,
 370         .statfs         = nfs_statfs,
 371         .evict_inode    = nfs4_evict_inode,
 372         .umount_begin   = nfs_umount_begin,
 373         .show_options   = nfs_show_options,
 374         .show_devname   = nfs_show_devname,
 375         .show_path      = nfs_show_path,
 376         .show_stats     = nfs_show_stats,
 377         .remount_fs     = nfs_remount,
 378 };
 379 #endif
 380
 381 static struct shrinker acl_shrinker = {
 382         .shrink         = nfs_access_cache_shrinker,
 383         .seeks          = DEFAULT_SEEKS,
 384 };
 385
 386 /*
 387  * Register the NFS filesystems
 388  */
 389 int __init register_nfs_fs(void)
 390 {
 391         int ret;
 392
 393         ret = register_filesystem(&nfs_fs_type);
 394         if (ret < 0)
 395                 goto error_0;
 396
 397         ret = nfs_register_sysctl();
 398         if (ret < 0)
 399                 goto error_1;
 400 #ifdef CONFIG_NFS_V4
 401         ret = register_filesystem(&nfs4_fs_type);
 402         if (ret < 0)
 403                 goto error_2;
 404 #endif
 405         register_shrinker(&acl_shrinker);
 406         return 0;
 407
 408 #ifdef CONFIG_NFS_V4
 409 error_2:
 410         nfs_unregister_sysctl();
 411 #endif
 412 error_1:
 413         unregister_filesystem(&nfs_fs_type);
 414 error_0:
 415         return ret;
 416 }
 417
 418 /*
 419  * Unregister the NFS filesystems
 420  */
 421 void __exit unregister_nfs_fs(void)
 422 {
 423         unregister_shrinker(&acl_shrinker);
 424 #ifdef CONFIG_NFS_V4
 425         unregister_filesystem(&nfs4_fs_type);
 426 #endif
 427         nfs_unregister_sysctl();
 428         unregister_filesystem(&nfs_fs_type);
 429 }
 430
 431 void nfs_sb_active(struct super_block *sb)
 432 {
 433         struct nfs_server *server = NFS_SB(sb);
 434
 435         if (atomic_inc_return(&server->active) == 1)
 436                 atomic_inc(&sb->s_active);
 437 }
 438
 439 void nfs_sb_deactive(struct super_block *sb)
 440 {
 441         struct nfs_server *server = NFS_SB(sb);
 442
 443         if (atomic_dec_and_test(&server->active))
 444                 deactivate_super(sb);
 445 }
 446
 447 /*
 448  * Deliver file system statistics to userspace
 449  */
 450 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 451 {
 452         struct nfs_server *server = NFS_SB(dentry->d_sb);
 453         unsigned char blockbits;
 454         unsigned long blockres;
 455         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 456         struct nfs_fsstat res;
 457         int error = -ENOMEM;
 458
 459         res.fattr = nfs_alloc_fattr();
 460         if (res.fattr == NULL)
 461                 goto out_err;
 462
 463         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 464         if (unlikely(error == -ESTALE)) {
 465                 struct dentry *pd_dentry;
 466
 467                 pd_dentry = dget_parent(dentry);
 468                 if (pd_dentry != NULL) {
 469                         nfs_zap_caches(pd_dentry->d_inode);
 470                         dput(pd_dentry);
 471                 }
 472         }
 473         nfs_free_fattr(res.fattr);
 474         if (error < 0)
 475                 goto out_err;
 476
 477         buf->f_type = NFS_SUPER_MAGIC;
 478
 479         /*
 480          * Current versions of glibc do not correctly handle the
 481          * case where f_frsize != f_bsize.  Eventually we want to
 482          * report the value of wtmult in this field.
 483          */
 484         buf->f_frsize = dentry->d_sb->s_blocksize;
 485
 486         /*
 487          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 488          * are reported in units of f_frsize.  Linux hasn't had
 489          * an f_frsize field in its statfs struct until recently,
 490          * thus historically Linux's sys_statfs reports these
 491          * fields in units of f_bsize.
 492          */
 493         buf->f_bsize = dentry->d_sb->s_blocksize;
 494         blockbits = dentry->d_sb->s_blocksize_bits;
 495         blockres = (1 << blockbits) - 1;
 496         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 497         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 498         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 499
 500         buf->f_files = res.tfiles;
 501         buf->f_ffree = res.afiles;
 502
 503         buf->f_namelen = server->namelen;
 504
 505         return 0;
 506
 507  out_err:
 508         dprintk("%s: statfs error = %d\n", __func__, -error);
 509         return error;
 510 }
 511
 512 /*
 513  * Map the security flavour number to a name
 514  */
 515 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 516 {
 517         static const struct {
 518                 rpc_authflavor_t flavour;
 519                 const char *str;
 520         } sec_flavours[] = {
 521                 { RPC_AUTH_NULL, "null" },
 522                 { RPC_AUTH_UNIX, "sys" },
 523                 { RPC_AUTH_GSS_KRB5, "krb5" },
 524                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 525                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 526                 { RPC_AUTH_GSS_LKEY, "lkey" },
 527                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 528                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 529                 { RPC_AUTH_GSS_SPKM, "spkm" },
 530                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 531                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 532                 { UINT_MAX, "unknown" }
 533         };
 534         int i;
 535
 536         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 537                 if (sec_flavours[i].flavour == flavour)
 538                         break;
 539         }
 540         return sec_flavours[i].str;
 541 }
 542
 543 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 544                                   int showdefaults)
 545 {
 546         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 547
 548         seq_printf(m, ",mountproto=");
 549         switch (sap->sa_family) {
 550         case AF_INET:
 551                 switch (nfss->mountd_protocol) {
 552                 case IPPROTO_UDP:
 553                         seq_printf(m, RPCBIND_NETID_UDP);
 554                         break;
 555                 case IPPROTO_TCP:
 556                         seq_printf(m, RPCBIND_NETID_TCP);
 557                         break;
 558                 default:
 559                         if (showdefaults)
 560                                 seq_printf(m, "auto");
 561                 }
 562                 break;
 563         case AF_INET6:
 564                 switch (nfss->mountd_protocol) {
 565                 case IPPROTO_UDP:
 566                         seq_printf(m, RPCBIND_NETID_UDP6);
 567                         break;
 568                 case IPPROTO_TCP:
 569                         seq_printf(m, RPCBIND_NETID_TCP6);
 570                         break;
 571                 default:
 572                         if (showdefaults)
 573                                 seq_printf(m, "auto");
 574                 }
 575                 break;
 576         default:
 577                 if (showdefaults)
 578                         seq_printf(m, "auto");
 579         }
 580 }
 581
 582 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 583                                     int showdefaults)
 584 {
 585         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 586
 587         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 588                 return;
 589
 590         switch (sap->sa_family) {
 591         case AF_INET: {
 592                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 593                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 594                 break;
 595         }
 596         case AF_INET6: {
 597                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 598                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 599                 break;
 600         }
 601         default:
 602                 if (showdefaults)
 603                         seq_printf(m, ",mountaddr=unspecified");
 604         }
 605
 606         if (nfss->mountd_version || showdefaults)
 607                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 608         if ((nfss->mountd_port &&
 609                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 610                 showdefaults)
 611                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 612
 613         nfs_show_mountd_netid(m, nfss, showdefaults);
 614 }
 615
 616 #ifdef CONFIG_NFS_V4
 617 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 618                                     int showdefaults)
 619 {
 620         struct nfs_client *clp = nfss->nfs_client;
 621
 622         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 623         seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
 624 }
 625 #else
 626 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 627                                     int showdefaults)
 628 {
 629 }
 630 #endif
 631
 632 /*
 633  * Describe the mount options in force on this server representation
 634  */
 635 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 636                                    int showdefaults)
 637 {
 638         static const struct proc_nfs_info {
 639                 int flag;
 640                 const char *str;
 641                 const char *nostr;
 642         } nfs_info[] = {
 643                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 644                 { NFS_MOUNT_POSIX, ",posix", "" },
 645                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 646                 { NFS_MOUNT_NOAC, ",noac", "" },
 647                 { NFS_MOUNT_NONLM, ",nolock", "" },
 648                 { NFS_MOUNT_NOACL, ",noacl", "" },
 649                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 650                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 651                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 652                 { 0, NULL, NULL }
 653         };
 654         const struct proc_nfs_info *nfs_infop;
 655         struct nfs_client *clp = nfss->nfs_client;
 656         u32 version = clp->rpc_ops->version;
 657         int local_flock, local_fcntl;
 658
 659         seq_printf(m, ",vers=%u", version);
 660         seq_printf(m, ",rsize=%u", nfss->rsize);
 661         seq_printf(m, ",wsize=%u", nfss->wsize);
 662         if (nfss->bsize != 0)
 663                 seq_printf(m, ",bsize=%u", nfss->bsize);
 664         seq_printf(m, ",namlen=%u", nfss->namelen);
 665         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 666                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 667         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 668                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 669         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 670                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 671         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 672                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 673         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 674                 if (nfss->flags & nfs_infop->flag)
 675                         seq_puts(m, nfs_infop->str);
 676                 else
 677                         seq_puts(m, nfs_infop->nostr);
 678         }
 679         seq_printf(m, ",proto=%s",
 680                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 681         if (version == 4) {
 682                 if (nfss->port != NFS_PORT)
 683                         seq_printf(m, ",port=%u", nfss->port);
 684         } else
 685                 if (nfss->port)
 686                         seq_printf(m, ",port=%u", nfss->port);
 687
 688         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 689         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 690         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 691
 692         if (version != 4)
 693                 nfs_show_mountd_options(m, nfss, showdefaults);
 694         else
 695                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 696
 697         if (nfss->options & NFS_OPTION_FSCACHE)
 698                 seq_printf(m, ",fsc");
 699
 700         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 701                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 702                         seq_printf(m, ",lookupcache=none");
 703                 else
 704                         seq_printf(m, ",lookupcache=pos");
 705         }
 706
 707         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 708         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 709
 710         if (!local_flock && !local_fcntl)
 711                 seq_printf(m, ",local_lock=none");
 712         else if (local_flock && local_fcntl)
 713                 seq_printf(m, ",local_lock=all");
 714         else if (local_flock)
 715                 seq_printf(m, ",local_lock=flock");
 716         else
 717                 seq_printf(m, ",local_lock=posix");
 718 }
 719
 720 /*
 721  * Describe the mount options on this VFS mountpoint
 722  */
 723 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 724 {
 725         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 726
 727         nfs_show_mount_options(m, nfss, 0);
 728
 729         seq_printf(m, ",addr=%s",
 730                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 731                                                         RPC_DISPLAY_ADDR));
 732
 733         return 0;
 734 }
 735
 736 static int nfs_show_devname(struct seq_file *m, struct vfsmount *mnt)
 737 {
 738         char *page = (char *) __get_free_page(GFP_KERNEL);
 739         char *devname, *dummy;
 740         int err = 0;
 741         if (!page)
 742                 return -ENOMEM;
 743         devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE);
 744         if (IS_ERR(devname))
 745                 err = PTR_ERR(devname);
 746         else
 747                 seq_escape(m, devname, " \t\n\\");
 748         free_page((unsigned long)page);
 749         return err;
 750 }
 751
 752 static int nfs_show_path(struct seq_file *m, struct vfsmount *mnt)
 753 {
 754         seq_puts(m, "/");
 755         return 0;
 756 }
 757
 758 /*
 759  * Present statistical information for this VFS mountpoint
 760  */
 761 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 762 {
 763         int i, cpu;
 764         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 765         struct rpc_auth *auth = nfss->client->cl_auth;
 766         struct nfs_iostats totals = { };
 767
 768         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 769
 770         /*
 771          * Display all mount option settings
 772          */
 773         seq_printf(m, "\n\topts:\t");
 774         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 775         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 776         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 777         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 778         nfs_show_mount_options(m, nfss, 1);
 779
 780         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 781
 782         seq_printf(m, "\n\tcaps:\t");
 783         seq_printf(m, "caps=0x%x", nfss->caps);
 784         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 785         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 786         seq_printf(m, ",bsize=%u", nfss->bsize);
 787         seq_printf(m, ",namlen=%u", nfss->namelen);
 788
 789 #ifdef CONFIG_NFS_V4
 790         if (nfss->nfs_client->rpc_ops->version == 4) {
 791                 seq_printf(m, "\n\tnfsv4:\t");
 792                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 793                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 794                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 795         }
 796 #endif
 797
 798         /*
 799          * Display security flavor in effect for this mount
 800          */
 801         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 802         if (auth->au_flavor)
 803                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 804
 805         /*
 806          * Display superblock I/O counters
 807          */
 808         for_each_possible_cpu(cpu) {
 809                 struct nfs_iostats *stats;
 810
 811                 preempt_disable();
 812                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 813
 814                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 815                         totals.events[i] += stats->events[i];
 816                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 817                         totals.bytes[i] += stats->bytes[i];
 818 #ifdef CONFIG_NFS_FSCACHE
 819                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 820                         totals.fscache[i] += stats->fscache[i];
 821 #endif
 822
 823                 preempt_enable();
 824         }
 825
 826         seq_printf(m, "\n\tevents:\t");
 827         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 828                 seq_printf(m, "%lu ", totals.events[i]);
 829         seq_printf(m, "\n\tbytes:\t");
 830         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 831                 seq_printf(m, "%Lu ", totals.bytes[i]);
 832 #ifdef CONFIG_NFS_FSCACHE
 833         if (nfss->options & NFS_OPTION_FSCACHE) {
 834                 seq_printf(m, "\n\tfsc:\t");
 835                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 836                         seq_printf(m, "%Lu ", totals.bytes[i]);
 837         }
 838 #endif
 839         seq_printf(m, "\n");
 840
 841         rpc_print_iostats(m, nfss->client);
 842
 843         return 0;
 844 }
 845
 846 /*
 847  * Begin unmount by attempting to remove all automounted mountpoints we added
 848  * in response to xdev traversals and referrals
 849  */
 850 static void nfs_umount_begin(struct super_block *sb)
 851 {
 852         struct nfs_server *server;
 853         struct rpc_clnt *rpc;
 854
 855         server = NFS_SB(sb);
 856         /* -EIO all pending I/O */
 857         rpc = server->client_acl;
 858         if (!IS_ERR(rpc))
 859                 rpc_killall_tasks(rpc);
 860         rpc = server->client;
 861         if (!IS_ERR(rpc))
 862                 rpc_killall_tasks(rpc);
 863 }
 864
 865 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 866 {
 867         struct nfs_parsed_mount_data *data;
 868
 869         data = kzalloc(sizeof(*data), GFP_KERNEL);
 870         if (data) {
 871                 data->acregmin          = NFS_DEF_ACREGMIN;
 872                 data->acregmax          = NFS_DEF_ACREGMAX;
 873                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 874                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 875                 data->mount_server.port = NFS_UNSPEC_PORT;
 876                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 877                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 878                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 879                 data->auth_flavor_len   = 1;
 880                 data->version           = version;
 881                 data->minorversion      = 0;
 882         }
 883         return data;
 884 }
 885
 886 /*
 887  * Sanity-check a server address provided by the mount command.
 888  *
 889  * Address family must be initialized, and address must not be
 890  * the ANY address for that family.
 891  */
 892 static int nfs_verify_server_address(struct sockaddr *addr)
 893 {
 894         switch (addr->sa_family) {
 895         case AF_INET: {
 896                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 897                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 898         }
 899         case AF_INET6: {
 900                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 901                 return !ipv6_addr_any(sa);
 902         }
 903         }
 904
 905         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 906         return 0;
 907 }
 908
 909 /*
 910  * Select between a default port value and a user-specified port value.
 911  * If a zero value is set, then autobind will be used.
 912  */
 913 static void nfs_set_port(struct sockaddr *sap, int *port,
 914                                  const unsigned short default_port)
 915 {
 916         if (*port == NFS_UNSPEC_PORT)
 917                 *port = default_port;
 918
 919         rpc_set_port(sap, *port);
 920 }
 921
 922 /*
 923  * Sanity check the NFS transport protocol.
 924  *
 925  */
 926 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 927 {
 928         switch (mnt->nfs_server.protocol) {
 929         case XPRT_TRANSPORT_UDP:
 930         case XPRT_TRANSPORT_TCP:
 931         case XPRT_TRANSPORT_RDMA:
 932                 break;
 933         default:
 934                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 935         }
 936 }
 937
 938 /*
 939  * For text based NFSv2/v3 mounts, the mount protocol transport default
 940  * settings should depend upon the specified NFS transport.
 941  */
 942 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 943 {
 944         nfs_validate_transport_protocol(mnt);
 945
 946         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 947             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 948                         return;
 949         switch (mnt->nfs_server.protocol) {
 950         case XPRT_TRANSPORT_UDP:
 951                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 952                 break;
 953         case XPRT_TRANSPORT_TCP:
 954         case XPRT_TRANSPORT_RDMA:
 955                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 956         }
 957 }
 958
 959 /*
 960  * Parse the value of the 'sec=' option.
 961  */
 962 static int nfs_parse_security_flavors(char *value,
 963                                       struct nfs_parsed_mount_data *mnt)
 964 {
 965         substring_t args[MAX_OPT_ARGS];
 966
 967         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 968
 969         switch (match_token(value, nfs_secflavor_tokens, args)) {
 970         case Opt_sec_none:
 971                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 972                 break;
 973         case Opt_sec_sys:
 974                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 975                 break;
 976         case Opt_sec_krb5:
 977                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 978                 break;
 979         case Opt_sec_krb5i:
 980                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 981                 break;
 982         case Opt_sec_krb5p:
 983                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 984                 break;
 985         case Opt_sec_lkey:
 986                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 987                 break;
 988         case Opt_sec_lkeyi:
 989                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 990                 break;
 991         case Opt_sec_lkeyp:
 992                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 993                 break;
 994         case Opt_sec_spkm:
 995                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 996                 break;
 997         case Opt_sec_spkmi:
 998                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 999                 break;
1000         case Opt_sec_spkmp:
1001                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1002                 break;
1003         default:
1004                 return 0;
1005         }
1006
1007         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1008         mnt->auth_flavor_len = 1;
1009         return 1;
1010 }
1011
1012 static int nfs_get_option_str(substring_t args[], char **option)
1013 {
1014         kfree(*option);
1015         *option = match_strdup(args);
1016         return !option;
1017 }
1018
1019 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1020 {
1021         int rc;
1022         char *string;
1023
1024         string = match_strdup(args);
1025         if (string == NULL)
1026                 return -ENOMEM;
1027         rc = strict_strtoul(string, 10, option);
1028         kfree(string);
1029
1030         return rc;
1031 }
1032
1033 /*
1034  * Error-check and convert a string of mount options from user space into
1035  * a data structure.  The whole mount string is processed; bad options are
1036  * skipped as they are encountered.  If there were no errors, return 1;
1037  * otherwise return 0 (zero).
1038  */
1039 static int nfs_parse_mount_options(char *raw,
1040                                    struct nfs_parsed_mount_data *mnt)
1041 {
1042         char *p, *string, *secdata;
1043         int rc, sloppy = 0, invalid_option = 0;
1044         unsigned short protofamily = AF_UNSPEC;
1045         unsigned short mountfamily = AF_UNSPEC;
1046
1047         if (!raw) {
1048                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1049                 return 1;
1050         }
1051         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1052
1053         secdata = alloc_secdata();
1054         if (!secdata)
1055                 goto out_nomem;
1056
1057         rc = security_sb_copy_data(raw, secdata);
1058         if (rc)
1059                 goto out_security_failure;
1060
1061         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1062         if (rc)
1063                 goto out_security_failure;
1064
1065         free_secdata(secdata);
1066
1067         while ((p = strsep(&raw, ",")) != NULL) {
1068                 substring_t args[MAX_OPT_ARGS];
1069                 unsigned long option;
1070                 int token;
1071
1072                 if (!*p)
1073                         continue;
1074
1075                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1076
1077                 token = match_token(p, nfs_mount_option_tokens, args);
1078                 switch (token) {
1079
1080                 /*
1081                  * boolean options:  foo/nofoo
1082                  */
1083                 case Opt_soft:
1084                         mnt->flags |= NFS_MOUNT_SOFT;
1085                         break;
1086                 case Opt_hard:
1087                         mnt->flags &= ~NFS_MOUNT_SOFT;
1088                         break;
1089                 case Opt_posix:
1090                         mnt->flags |= NFS_MOUNT_POSIX;
1091                         break;
1092                 case Opt_noposix:
1093                         mnt->flags &= ~NFS_MOUNT_POSIX;
1094                         break;
1095                 case Opt_cto:
1096                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1097                         break;
1098                 case Opt_nocto:
1099                         mnt->flags |= NFS_MOUNT_NOCTO;
1100                         break;
1101                 case Opt_ac:
1102                         mnt->flags &= ~NFS_MOUNT_NOAC;
1103                         break;
1104                 case Opt_noac:
1105                         mnt->flags |= NFS_MOUNT_NOAC;
1106                         break;
1107                 case Opt_lock:
1108                         mnt->flags &= ~NFS_MOUNT_NONLM;
1109                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1110                                         NFS_MOUNT_LOCAL_FCNTL);
1111                         break;
1112                 case Opt_nolock:
1113                         mnt->flags |= NFS_MOUNT_NONLM;
1114                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1115                                        NFS_MOUNT_LOCAL_FCNTL);
1116                         break;
1117                 case Opt_v2:
1118                         mnt->flags &= ~NFS_MOUNT_VER3;
1119                         mnt->version = 2;
1120                         break;
1121                 case Opt_v3:
1122                         mnt->flags |= NFS_MOUNT_VER3;
1123                         mnt->version = 3;
1124                         break;
1125                 case Opt_v4:
1126                         mnt->flags &= ~NFS_MOUNT_VER3;
1127                         mnt->version = 4;
1128                         break;
1129                 case Opt_udp:
1130                         mnt->flags &= ~NFS_MOUNT_TCP;
1131                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1132                         break;
1133                 case Opt_tcp:
1134                         mnt->flags |= NFS_MOUNT_TCP;
1135                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1136                         break;
1137                 case Opt_rdma:
1138                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1139                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1140                         xprt_load_transport(p);
1141                         break;
1142                 case Opt_acl:
1143                         mnt->flags &= ~NFS_MOUNT_NOACL;
1144                         break;
1145                 case Opt_noacl:
1146                         mnt->flags |= NFS_MOUNT_NOACL;
1147                         break;
1148                 case Opt_rdirplus:
1149                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1150                         break;
1151                 case Opt_nordirplus:
1152                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1153                         break;
1154                 case Opt_sharecache:
1155                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1156                         break;
1157                 case Opt_nosharecache:
1158                         mnt->flags |= NFS_MOUNT_UNSHARED;
1159                         break;
1160                 case Opt_resvport:
1161                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1162                         break;
1163                 case Opt_noresvport:
1164                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1165                         break;
1166                 case Opt_fscache:
1167                         mnt->options |= NFS_OPTION_FSCACHE;
1168                         kfree(mnt->fscache_uniq);
1169                         mnt->fscache_uniq = NULL;
1170                         break;
1171                 case Opt_nofscache:
1172                         mnt->options &= ~NFS_OPTION_FSCACHE;
1173                         kfree(mnt->fscache_uniq);
1174                         mnt->fscache_uniq = NULL;
1175                         break;
1176
1177                 /*
1178                  * options that take numeric values
1179                  */
1180                 case Opt_port:
1181                         if (nfs_get_option_ul(args, &option) ||
1182                             option > USHRT_MAX)
1183                                 goto out_invalid_value;
1184                         mnt->nfs_server.port = option;
1185                         break;
1186                 case Opt_rsize:
1187                         if (nfs_get_option_ul(args, &option))
1188                                 goto out_invalid_value;
1189                         mnt->rsize = option;
1190                         break;
1191                 case Opt_wsize:
1192                         if (nfs_get_option_ul(args, &option))
1193                                 goto out_invalid_value;
1194                         mnt->wsize = option;
1195                         break;
1196                 case Opt_bsize:
1197                         if (nfs_get_option_ul(args, &option))
1198                                 goto out_invalid_value;
1199                         mnt->bsize = option;
1200                         break;
1201                 case Opt_timeo:
1202                         if (nfs_get_option_ul(args, &option) || option == 0)
1203                                 goto out_invalid_value;
1204                         mnt->timeo = option;
1205                         break;
1206                 case Opt_retrans:
1207                         if (nfs_get_option_ul(args, &option) || option == 0)
1208                                 goto out_invalid_value;
1209                         mnt->retrans = option;
1210                         break;
1211                 case Opt_acregmin:
1212                         if (nfs_get_option_ul(args, &option))
1213                                 goto out_invalid_value;
1214                         mnt->acregmin = option;
1215                         break;
1216                 case Opt_acregmax:
1217                         if (nfs_get_option_ul(args, &option))
1218                                 goto out_invalid_value;
1219                         mnt->acregmax = option;
1220                         break;
1221                 case Opt_acdirmin:
1222                         if (nfs_get_option_ul(args, &option))
1223                                 goto out_invalid_value;
1224                         mnt->acdirmin = option;
1225                         break;
1226                 case Opt_acdirmax:
1227                         if (nfs_get_option_ul(args, &option))
1228                                 goto out_invalid_value;
1229                         mnt->acdirmax = option;
1230                         break;
1231                 case Opt_actimeo:
1232                         if (nfs_get_option_ul(args, &option))
1233                                 goto out_invalid_value;
1234                         mnt->acregmin = mnt->acregmax =
1235                         mnt->acdirmin = mnt->acdirmax = option;
1236                         break;
1237                 case Opt_namelen:
1238                         if (nfs_get_option_ul(args, &option))
1239                                 goto out_invalid_value;
1240                         mnt->namlen = option;
1241                         break;
1242                 case Opt_mountport:
1243                         if (nfs_get_option_ul(args, &option) ||
1244                             option > USHRT_MAX)
1245                                 goto out_invalid_value;
1246                         mnt->mount_server.port = option;
1247                         break;
1248                 case Opt_mountvers:
1249                         if (nfs_get_option_ul(args, &option) ||
1250                             option < NFS_MNT_VERSION ||
1251                             option > NFS_MNT3_VERSION)
1252                                 goto out_invalid_value;
1253                         mnt->mount_server.version = option;
1254                         break;
1255                 case Opt_nfsvers:
1256                         if (nfs_get_option_ul(args, &option))
1257                                 goto out_invalid_value;
1258                         switch (option) {
1259                         case NFS2_VERSION:
1260                                 mnt->flags &= ~NFS_MOUNT_VER3;
1261                                 mnt->version = 2;
1262                                 break;
1263                         case NFS3_VERSION:
1264                                 mnt->flags |= NFS_MOUNT_VER3;
1265                                 mnt->version = 3;
1266                                 break;
1267                         case NFS4_VERSION:
1268                                 mnt->flags &= ~NFS_MOUNT_VER3;
1269                                 mnt->version = 4;
1270                                 break;
1271                         default:
1272                                 goto out_invalid_value;
1273                         }
1274                         break;
1275                 case Opt_minorversion:
1276                         if (nfs_get_option_ul(args, &option))
1277                                 goto out_invalid_value;
1278                         if (option > NFS4_MAX_MINOR_VERSION)
1279                                 goto out_invalid_value;
1280                         mnt->minorversion = option;
1281                         break;
1282
1283                 /*
1284                  * options that take text values
1285                  */
1286                 case Opt_sec:
1287                         string = match_strdup(args);
1288                         if (string == NULL)
1289                                 goto out_nomem;
1290                         rc = nfs_parse_security_flavors(string, mnt);
1291                         kfree(string);
1292                         if (!rc) {
1293                                 dfprintk(MOUNT, "NFS:   unrecognized "
1294                                                 "security flavor\n");
1295                                 return 0;
1296                         }
1297                         break;
1298                 case Opt_proto:
1299                         string = match_strdup(args);
1300                         if (string == NULL)
1301                                 goto out_nomem;
1302                         token = match_token(string,
1303                                             nfs_xprt_protocol_tokens, args);
1304
1305                         protofamily = AF_INET;
1306                         switch (token) {
1307                         case Opt_xprt_udp6:
1308                                 protofamily = AF_INET6;
1309                         case Opt_xprt_udp:
1310                                 mnt->flags &= ~NFS_MOUNT_TCP;
1311                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1312                                 break;
1313                         case Opt_xprt_tcp6:
1314                                 protofamily = AF_INET6;
1315                         case Opt_xprt_tcp:
1316                                 mnt->flags |= NFS_MOUNT_TCP;
1317                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1318                                 break;
1319                         case Opt_xprt_rdma:
1320                                 /* vector side protocols to TCP */
1321                                 mnt->flags |= NFS_MOUNT_TCP;
1322                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1323                                 xprt_load_transport(string);
1324                                 break;
1325                         default:
1326                                 dfprintk(MOUNT, "NFS:   unrecognized "
1327                                                 "transport protocol\n");
1328                                 kfree(string);
1329                                 return 0;
1330                         }
1331                         kfree(string);
1332                         break;
1333                 case Opt_mountproto:
1334                         string = match_strdup(args);
1335                         if (string == NULL)
1336                                 goto out_nomem;
1337                         token = match_token(string,
1338                                             nfs_xprt_protocol_tokens, args);
1339                         kfree(string);
1340
1341                         mountfamily = AF_INET;
1342                         switch (token) {
1343                         case Opt_xprt_udp6:
1344                                 mountfamily = AF_INET6;
1345                         case Opt_xprt_udp:
1346                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1347                                 break;
1348                         case Opt_xprt_tcp6:
1349                                 mountfamily = AF_INET6;
1350                         case Opt_xprt_tcp:
1351                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1352                                 break;
1353                         case Opt_xprt_rdma: /* not used for side protocols */
1354                         default:
1355                                 dfprintk(MOUNT, "NFS:   unrecognized "
1356                                                 "transport protocol\n");
1357                                 return 0;
1358                         }
1359                         break;
1360                 case Opt_addr:
1361                         string = match_strdup(args);
1362                         if (string == NULL)
1363                                 goto out_nomem;
1364                         mnt->nfs_server.addrlen =
1365                                 rpc_pton(string, strlen(string),
1366                                         (struct sockaddr *)
1367                                         &mnt->nfs_server.address,
1368                                         sizeof(mnt->nfs_server.address));
1369                         kfree(string);
1370                         if (mnt->nfs_server.addrlen == 0)
1371                                 goto out_invalid_address;
1372                         break;
1373                 case Opt_clientaddr:
1374                         if (nfs_get_option_str(args, &mnt->client_address))
1375                                 goto out_nomem;
1376                         break;
1377                 case Opt_mounthost:
1378                         if (nfs_get_option_str(args,
1379                                                &mnt->mount_server.hostname))
1380                                 goto out_nomem;
1381                         break;
1382                 case Opt_mountaddr:
1383                         string = match_strdup(args);
1384                         if (string == NULL)
1385                                 goto out_nomem;
1386                         mnt->mount_server.addrlen =
1387                                 rpc_pton(string, strlen(string),
1388                                         (struct sockaddr *)
1389                                         &mnt->mount_server.address,
1390                                         sizeof(mnt->mount_server.address));
1391                         kfree(string);
1392                         if (mnt->mount_server.addrlen == 0)
1393                                 goto out_invalid_address;
1394                         break;
1395                 case Opt_lookupcache:
1396                         string = match_strdup(args);
1397                         if (string == NULL)
1398                                 goto out_nomem;
1399                         token = match_token(string,
1400                                         nfs_lookupcache_tokens, args);
1401                         kfree(string);
1402                         switch (token) {
1403                                 case Opt_lookupcache_all:
1404                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1405                                         break;
1406                                 case Opt_lookupcache_positive:
1407                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1408                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1409                                         break;
1410                                 case Opt_lookupcache_none:
1411                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1412                                         break;
1413                                 default:
1414                                         dfprintk(MOUNT, "NFS:   invalid "
1415                                                         "lookupcache argument\n");
1416                                         return 0;
1417                         };
1418                         break;
1419                 case Opt_fscache_uniq:
1420                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1421                                 goto out_nomem;
1422                         mnt->options |= NFS_OPTION_FSCACHE;
1423                         break;
1424                 case Opt_local_lock:
1425                         string = match_strdup(args);
1426                         if (string == NULL)
1427                                 goto out_nomem;
1428                         token = match_token(string, nfs_local_lock_tokens,
1429                                         args);
1430                         kfree(string);
1431                         switch (token) {
1432                         case Opt_local_lock_all:
1433                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1434                                                NFS_MOUNT_LOCAL_FCNTL);
1435                                 break;
1436                         case Opt_local_lock_flock:
1437                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1438                                 break;
1439                         case Opt_local_lock_posix:
1440                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1441                                 break;
1442                         case Opt_local_lock_none:
1443                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1444                                                 NFS_MOUNT_LOCAL_FCNTL);
1445                                 break;
1446                         default:
1447                                 dfprintk(MOUNT, "NFS:   invalid "
1448                                                 "local_lock argument\n");
1449                                 return 0;
1450                         };
1451                         break;
1452
1453                 /*
1454                  * Special options
1455                  */
1456                 case Opt_sloppy:
1457                         sloppy = 1;
1458                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1459                         break;
1460                 case Opt_userspace:
1461                 case Opt_deprecated:
1462                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1463                                         "'%s'\n", p);
1464                         break;
1465
1466                 default:
1467                         invalid_option = 1;
1468                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1469                                         "'%s'\n", p);
1470                 }
1471         }
1472
1473         if (!sloppy && invalid_option)
1474                 return 0;
1475
1476         /*
1477          * verify that any proto=/mountproto= options match the address
1478          * familiies in the addr=/mountaddr= options.
1479          */
1480         if (protofamily != AF_UNSPEC &&
1481             protofamily != mnt->nfs_server.address.ss_family)
1482                 goto out_proto_mismatch;
1483
1484         if (mountfamily != AF_UNSPEC) {
1485                 if (mnt->mount_server.addrlen) {
1486                         if (mountfamily != mnt->mount_server.address.ss_family)
1487                                 goto out_mountproto_mismatch;
1488                 } else {
1489                         if (mountfamily != mnt->nfs_server.address.ss_family)
1490                                 goto out_mountproto_mismatch;
1491                 }
1492         }
1493
1494         return 1;
1495
1496 out_mountproto_mismatch:
1497         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1498                          "option\n");
1499         return 0;
1500 out_proto_mismatch:
1501         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1502         return 0;
1503 out_invalid_address:
1504         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1505         return 0;
1506 out_invalid_value:
1507         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1508         return 0;
1509 out_nomem:
1510         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1511         return 0;
1512 out_security_failure:
1513         free_secdata(secdata);
1514         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1515         return 0;
1516 }
1517
1518 /*
1519  * Match the requested auth flavors with the list returned by
1520  * the server.  Returns zero and sets the mount's authentication
1521  * flavor on success; returns -EACCES if server does not support
1522  * the requested flavor.
1523  */
1524 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1525                              struct nfs_mount_request *request)
1526 {
1527         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1528
1529         /*
1530          * Certain releases of Linux's mountd return an empty
1531          * flavor list.  To prevent behavioral regression with
1532          * these servers (ie. rejecting mounts that used to
1533          * succeed), revert to pre-2.6.32 behavior (no checking)
1534          * if the returned flavor list is empty.
1535          */
1536         if (server_authlist_len == 0)
1537                 return 0;
1538
1539         /*
1540          * We avoid sophisticated negotiating here, as there are
1541          * plenty of cases where we can get it wrong, providing
1542          * either too little or too much security.
1543          *
1544          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1545          * flavor listed first.  However, some servers list
1546          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1547          * preferred default, in args->auth_flavors[0] if user
1548          * didn't specify sec= mount option.
1549          */
1550         for (i = 0; i < args->auth_flavor_len; i++)
1551                 for (j = 0; j < server_authlist_len; j++)
1552                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1553                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1554                                         request->auth_flavs[j]);
1555                                 args->auth_flavors[0] = request->auth_flavs[j];
1556                                 return 0;
1557                         }
1558
1559         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1560         nfs_umount(request);
1561         return -EACCES;
1562 }
1563
1564 /*
1565  * Use the remote server's MOUNT service to request the NFS file handle
1566  * corresponding to the provided path.
1567  */
1568 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1569                          struct nfs_fh *root_fh)
1570 {
1571         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1572         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1573         struct nfs_mount_request request = {
1574                 .sap            = (struct sockaddr *)
1575                                                 &args->mount_server.address,
1576                 .dirpath        = args->nfs_server.export_path,
1577                 .protocol       = args->mount_server.protocol,
1578                 .fh             = root_fh,
1579                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1580                 .auth_flav_len  = &server_authlist_len,
1581                 .auth_flavs     = server_authlist,
1582         };
1583         int status;
1584
1585         if (args->mount_server.version == 0) {
1586                 switch (args->version) {
1587                         default:
1588                                 args->mount_server.version = NFS_MNT3_VERSION;
1589                                 break;
1590                         case 2:
1591                                 args->mount_server.version = NFS_MNT_VERSION;
1592                 }
1593         }
1594         request.version = args->mount_server.version;
1595
1596         if (args->mount_server.hostname)
1597                 request.hostname = args->mount_server.hostname;
1598         else
1599                 request.hostname = args->nfs_server.hostname;
1600
1601         /*
1602          * Construct the mount server's address.
1603          */
1604         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1605                 memcpy(request.sap, &args->nfs_server.address,
1606                        args->nfs_server.addrlen);
1607                 args->mount_server.addrlen = args->nfs_server.addrlen;
1608         }
1609         request.salen = args->mount_server.addrlen;
1610         nfs_set_port(request.sap, &args->mount_server.port, 0);
1611
1612         /*
1613          * Now ask the mount server to map our export path
1614          * to a file handle.
1615          */
1616         status = nfs_mount(&request);
1617         if (status != 0) {
1618                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1619                                 request.hostname, status);
1620                 return status;
1621         }
1622
1623         /*
1624          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1625          */
1626         if (args->mount_server.version != NFS_MNT3_VERSION)
1627                 return 0;
1628         return nfs_walk_authlist(args, &request);
1629 }
1630
1631 /*
1632  * Split "dev_name" into "hostname:export_path".
1633  *
1634  * The leftmost colon demarks the split between the server's hostname
1635  * and the export path.  If the hostname starts with a left square
1636  * bracket, then it may contain colons.
1637  *
1638  * Note: caller frees hostname and export path, even on error.
1639  */
1640 static int nfs_parse_devname(const char *dev_name,
1641                              char **hostname, size_t maxnamlen,
1642                              char **export_path, size_t maxpathlen)
1643 {
1644         size_t len;
1645         char *end;
1646
1647         /* Is the host name protected with square brakcets? */
1648         if (*dev_name == '[') {
1649                 end = strchr(++dev_name, ']');
1650                 if (end == NULL || end[1] != ':')
1651                         goto out_bad_devname;
1652
1653                 len = end - dev_name;
1654                 end++;
1655         } else {
1656                 char *comma;
1657
1658                 end = strchr(dev_name, ':');
1659                 if (end == NULL)
1660                         goto out_bad_devname;
1661                 len = end - dev_name;
1662
1663                 /* kill possible hostname list: not supported */
1664                 comma = strchr(dev_name, ',');
1665                 if (comma != NULL && comma < end)
1666                         *comma = 0;
1667         }
1668
1669         if (len > maxnamlen)
1670                 goto out_hostname;
1671
1672         /* N.B. caller will free nfs_server.hostname in all cases */
1673         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1674         if (*hostname == NULL)
1675                 goto out_nomem;
1676         len = strlen(++end);
1677         if (len > maxpathlen)
1678                 goto out_path;
1679         *export_path = kstrndup(end, len, GFP_KERNEL);
1680         if (!*export_path)
1681                 goto out_nomem;
1682
1683         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1684         return 0;
1685
1686 out_bad_devname:
1687         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1688         return -EINVAL;
1689
1690 out_nomem:
1691         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1692         return -ENOMEM;
1693
1694 out_hostname:
1695         dfprintk(MOUNT, "NFS: server hostname too long\n");
1696         return -ENAMETOOLONG;
1697
1698 out_path:
1699         dfprintk(MOUNT, "NFS: export pathname too long\n");
1700         return -ENAMETOOLONG;
1701 }
1702
1703 /*
1704  * Validate the NFS2/NFS3 mount data
1705  * - fills in the mount root filehandle
1706  *
1707  * For option strings, user space handles the following behaviors:
1708  *
1709  * + DNS: mapping server host name to IP address ("addr=" option)
1710  *
1711  * + failure mode: how to behave if a mount request can't be handled
1712  *   immediately ("fg/bg" option)
1713  *
1714  * + retry: how often to retry a mount request ("retry=" option)
1715  *
1716  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1717  *   mountproto=tcp after mountproto=udp, and so on
1718  */
1719 static int nfs_validate_mount_data(void *options,
1720                                    struct nfs_parsed_mount_data *args,
1721                                    struct nfs_fh *mntfh,
1722                                    const char *dev_name)
1723 {
1724         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1725         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1726
1727         if (data == NULL)
1728                 goto out_no_data;
1729
1730         switch (data->version) {
1731         case 1:
1732                 data->namlen = 0;
1733         case 2:
1734                 data->bsize = 0;
1735         case 3:
1736                 if (data->flags & NFS_MOUNT_VER3)
1737                         goto out_no_v3;
1738                 data->root.size = NFS2_FHSIZE;
1739                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1740         case 4:
1741                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1742                         goto out_no_sec;
1743         case 5:
1744                 memset(data->context, 0, sizeof(data->context));
1745         case 6:
1746                 if (data->flags & NFS_MOUNT_VER3) {
1747                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1748                                 goto out_invalid_fh;
1749                         mntfh->size = data->root.size;
1750                         args->version = 3;
1751                 } else {
1752                         mntfh->size = NFS2_FHSIZE;
1753                         args->version = 2;
1754                 }
1755
1756
1757                 memcpy(mntfh->data, data->root.data, mntfh->size);
1758                 if (mntfh->size < sizeof(mntfh->data))
1759                         memset(mntfh->data + mntfh->size, 0,
1760                                sizeof(mntfh->data) - mntfh->size);
1761
1762                 /*
1763                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1764                  * can deal with.
1765                  */
1766                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1767                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1768                 args->rsize             = data->rsize;
1769                 args->wsize             = data->wsize;
1770                 args->timeo             = data->timeo;
1771                 args->retrans           = data->retrans;
1772                 args->acregmin          = data->acregmin;
1773                 args->acregmax          = data->acregmax;
1774                 args->acdirmin          = data->acdirmin;
1775                 args->acdirmax          = data->acdirmax;
1776
1777                 memcpy(sap, &data->addr, sizeof(data->addr));
1778                 args->nfs_server.addrlen = sizeof(data->addr);
1779                 if (!nfs_verify_server_address(sap))
1780                         goto out_no_address;
1781
1782                 if (!(data->flags & NFS_MOUNT_TCP))
1783                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1784                 /* N.B. caller will free nfs_server.hostname in all cases */
1785                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1786                 args->namlen            = data->namlen;
1787                 args->bsize             = data->bsize;
1788
1789                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1790                         args->auth_flavors[0] = data->pseudoflavor;
1791                 if (!args->nfs_server.hostname)
1792                         goto out_nomem;
1793
1794                 if (!(data->flags & NFS_MOUNT_NONLM))
1795                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1796                                          NFS_MOUNT_LOCAL_FCNTL);
1797                 else
1798                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1799                                         NFS_MOUNT_LOCAL_FCNTL);
1800                 /*
1801                  * The legacy version 6 binary mount data from userspace has a
1802                  * field used only to transport selinux information into the
1803                  * the kernel.  To continue to support that functionality we
1804                  * have a touch of selinux knowledge here in the NFS code. The
1805                  * userspace code converted context=blah to just blah so we are
1806                  * converting back to the full string selinux understands.
1807                  */
1808                 if (data->context[0]){
1809 #ifdef CONFIG_SECURITY_SELINUX
1810                         int rc;
1811                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1812                         if (!opts_str)
1813                                 return -ENOMEM;
1814                         strcpy(opts_str, "context=");
1815                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1816                         strcat(opts_str, &data->context[0]);
1817                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1818                         kfree(opts_str);
1819                         if (rc)
1820                                 return rc;
1821 #else
1822                         return -EINVAL;
1823 #endif
1824                 }
1825
1826                 break;
1827         default: {
1828                 int status;
1829
1830                 if (nfs_parse_mount_options((char *)options, args) == 0)
1831                         return -EINVAL;
1832
1833                 if (!nfs_verify_server_address(sap))
1834                         goto out_no_address;
1835
1836                 if (args->version == 4)
1837 #ifdef CONFIG_NFS_V4
1838                         return nfs4_validate_text_mount_data(options,
1839                                                              args, dev_name);
1840 #else
1841                         goto out_v4_not_compiled;
1842 #endif
1843
1844                 nfs_set_port(sap, &args->nfs_server.port, 0);
1845
1846                 nfs_set_mount_transport_protocol(args);
1847
1848                 status = nfs_parse_devname(dev_name,
1849                                            &args->nfs_server.hostname,
1850                                            PAGE_SIZE,
1851                                            &args->nfs_server.export_path,
1852                                            NFS_MAXPATHLEN);
1853                 if (!status)
1854                         status = nfs_try_mount(args, mntfh);
1855
1856                 kfree(args->nfs_server.export_path);
1857                 args->nfs_server.export_path = NULL;
1858
1859                 if (status)
1860                         return status;
1861
1862                 break;
1863                 }
1864         }
1865
1866 #ifndef CONFIG_NFS_V3
1867         if (args->version == 3)
1868                 goto out_v3_not_compiled;
1869 #endif /* !CONFIG_NFS_V3 */
1870
1871         return 0;
1872
1873 out_no_data:
1874         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1875         return -EINVAL;
1876
1877 out_no_v3:
1878         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1879                  data->version);
1880         return -EINVAL;
1881
1882 out_no_sec:
1883         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1884         return -EINVAL;
1885
1886 #ifndef CONFIG_NFS_V3
1887 out_v3_not_compiled:
1888         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1889         return -EPROTONOSUPPORT;
1890 #endif /* !CONFIG_NFS_V3 */
1891
1892 #ifndef CONFIG_NFS_V4
1893 out_v4_not_compiled:
1894         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1895         return -EPROTONOSUPPORT;
1896 #endif /* !CONFIG_NFS_V4 */
1897
1898 out_nomem:
1899         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1900         return -ENOMEM;
1901
1902 out_no_address:
1903         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1904         return -EINVAL;
1905
1906 out_invalid_fh:
1907         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1908         return -EINVAL;
1909 }
1910
1911 static int
1912 nfs_compare_remount_data(struct nfs_server *nfss,
1913                          struct nfs_parsed_mount_data *data)
1914 {
1915         if (data->flags != nfss->flags ||
1916             data->rsize != nfss->rsize ||
1917             data->wsize != nfss->wsize ||
1918             data->retrans != nfss->client->cl_timeout->to_retries ||
1919             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1920             data->acregmin != nfss->acregmin / HZ ||
1921             data->acregmax != nfss->acregmax / HZ ||
1922             data->acdirmin != nfss->acdirmin / HZ ||
1923             data->acdirmax != nfss->acdirmax / HZ ||
1924             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1925             data->nfs_server.port != nfss->port ||
1926             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1927             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1928                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
1929                 return -EINVAL;
1930
1931         return 0;
1932 }
1933
1934 static int
1935 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1936 {
1937         int error;
1938         struct nfs_server *nfss = sb->s_fs_info;
1939         struct nfs_parsed_mount_data *data;
1940         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1941         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1942         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1943
1944         /*
1945          * Userspace mount programs that send binary options generally send
1946          * them populated with default values. We have no way to know which
1947          * ones were explicitly specified. Fall back to legacy behavior and
1948          * just return success.
1949          */
1950         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1951             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1952                                            options->version <= 6))))
1953                 return 0;
1954
1955         data = kzalloc(sizeof(*data), GFP_KERNEL);
1956         if (data == NULL)
1957                 return -ENOMEM;
1958
1959         /* fill out struct with values from existing mount */
1960         data->flags = nfss->flags;
1961         data->rsize = nfss->rsize;
1962         data->wsize = nfss->wsize;
1963         data->retrans = nfss->client->cl_timeout->to_retries;
1964         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1965         data->acregmin = nfss->acregmin / HZ;
1966         data->acregmax = nfss->acregmax / HZ;
1967         data->acdirmin = nfss->acdirmin / HZ;
1968         data->acdirmax = nfss->acdirmax / HZ;
1969         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1970         data->nfs_server.port = nfss->port;
1971         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1972         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1973                 data->nfs_server.addrlen);
1974
1975         /* overwrite those values with any that were specified */
1976         error = nfs_parse_mount_options((char *)options, data);
1977         if (error < 0)
1978                 goto out;
1979
1980         /*
1981          * noac is a special case. It implies -o sync, but that's not
1982          * necessarily reflected in the mtab options. do_remount_sb
1983          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
1984          * remount options, so we have to explicitly reset it.
1985          */
1986         if (data->flags & NFS_MOUNT_NOAC)
1987                 *flags |= MS_SYNCHRONOUS;
1988
1989         /* compare new mount options with old ones */
1990         error = nfs_compare_remount_data(nfss, data);
1991 out:
1992         kfree(data);
1993         return error;
1994 }
1995
1996 /*
1997  * Initialise the common bits of the superblock
1998  */
1999 static inline void nfs_initialise_sb(struct super_block *sb)
2000 {
2001         struct nfs_server *server = NFS_SB(sb);
2002
2003         sb->s_magic = NFS_SUPER_MAGIC;
2004
2005         /* We probably want something more informative here */
2006         snprintf(sb->s_id, sizeof(sb->s_id),
2007                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2008
2009         if (sb->s_blocksize == 0)
2010                 sb->s_blocksize = nfs_block_bits(server->wsize,
2011                                                  &sb->s_blocksize_bits);
2012
2013         if (server->flags & NFS_MOUNT_NOAC)
2014                 sb->s_flags |= MS_SYNCHRONOUS;
2015
2016         sb->s_bdi = &server->backing_dev_info;
2017
2018         nfs_super_set_maxbytes(sb, server->maxfilesize);
2019 }
2020
2021 /*
2022  * Finish setting up an NFS2/3 superblock
2023  */
2024 static void nfs_fill_super(struct super_block *sb,
2025                            struct nfs_parsed_mount_data *data)
2026 {
2027         struct nfs_server *server = NFS_SB(sb);
2028
2029         sb->s_blocksize_bits = 0;
2030         sb->s_blocksize = 0;
2031         if (data->bsize)
2032                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2033
2034         if (server->nfs_client->rpc_ops->version == 3) {
2035                 /* The VFS shouldn't apply the umask to mode bits. We will do
2036                  * so ourselves when necessary.
2037                  */
2038                 sb->s_flags |= MS_POSIXACL;
2039                 sb->s_time_gran = 1;
2040         }
2041
2042         sb->s_op = &nfs_sops;
2043         nfs_initialise_sb(sb);
2044 }
2045
2046 /*
2047  * Finish setting up a cloned NFS2/3 superblock
2048  */
2049 static void nfs_clone_super(struct super_block *sb,
2050                             const struct super_block *old_sb)
2051 {
2052         struct nfs_server *server = NFS_SB(sb);
2053
2054         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2055         sb->s_blocksize = old_sb->s_blocksize;
2056         sb->s_maxbytes = old_sb->s_maxbytes;
2057
2058         if (server->nfs_client->rpc_ops->version == 3) {
2059                 /* The VFS shouldn't apply the umask to mode bits. We will do
2060                  * so ourselves when necessary.
2061                  */
2062                 sb->s_flags |= MS_POSIXACL;
2063                 sb->s_time_gran = 1;
2064         }
2065
2066         sb->s_op = old_sb->s_op;
2067         nfs_initialise_sb(sb);
2068 }
2069
2070 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2071 {
2072         const struct nfs_server *a = s->s_fs_info;
2073         const struct rpc_clnt *clnt_a = a->client;
2074         const struct rpc_clnt *clnt_b = b->client;
2075
2076         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2077                 goto Ebusy;
2078         if (a->nfs_client != b->nfs_client)
2079                 goto Ebusy;
2080         if (a->flags != b->flags)
2081                 goto Ebusy;
2082         if (a->wsize != b->wsize)
2083                 goto Ebusy;
2084         if (a->rsize != b->rsize)
2085                 goto Ebusy;
2086         if (a->acregmin != b->acregmin)
2087                 goto Ebusy;
2088         if (a->acregmax != b->acregmax)
2089                 goto Ebusy;
2090         if (a->acdirmin != b->acdirmin)
2091                 goto Ebusy;
2092         if (a->acdirmax != b->acdirmax)
2093                 goto Ebusy;
2094         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2095                 goto Ebusy;
2096         return 1;
2097 Ebusy:
2098         return 0;
2099 }
2100
2101 struct nfs_sb_mountdata {
2102         struct nfs_server *server;
2103         int mntflags;
2104 };
2105
2106 static int nfs_set_super(struct super_block *s, void *data)
2107 {
2108         struct nfs_sb_mountdata *sb_mntdata = data;
2109         struct nfs_server *server = sb_mntdata->server;
2110         int ret;
2111
2112         s->s_flags = sb_mntdata->mntflags;
2113         s->s_fs_info = server;
2114         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2115         ret = set_anon_super(s, server);
2116         if (ret == 0)
2117                 server->s_dev = s->s_dev;
2118         return ret;
2119 }
2120
2121 static int nfs_compare_super_address(struct nfs_server *server1,
2122                                      struct nfs_server *server2)
2123 {
2124         struct sockaddr *sap1, *sap2;
2125
2126         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2127         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2128
2129         if (sap1->sa_family != sap2->sa_family)
2130                 return 0;
2131
2132         switch (sap1->sa_family) {
2133         case AF_INET: {
2134                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2135                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2136                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2137                         return 0;
2138                 if (sin1->sin_port != sin2->sin_port)
2139                         return 0;
2140                 break;
2141         }
2142         case AF_INET6: {
2143                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2144                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2145                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2146                         return 0;
2147                 if (sin1->sin6_port != sin2->sin6_port)
2148                         return 0;
2149                 break;
2150         }
2151         default:
2152                 return 0;
2153         }
2154
2155         return 1;
2156 }
2157
2158 static int nfs_compare_super(struct super_block *sb, void *data)
2159 {
2160         struct nfs_sb_mountdata *sb_mntdata = data;
2161         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2162         int mntflags = sb_mntdata->mntflags;
2163
2164         if (!nfs_compare_super_address(old, server))
2165                 return 0;
2166         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2167         if (old->flags & NFS_MOUNT_UNSHARED)
2168                 return 0;
2169         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2170                 return 0;
2171         return nfs_compare_mount_options(sb, server, mntflags);
2172 }
2173
2174 static int nfs_bdi_register(struct nfs_server *server)
2175 {
2176         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2177 }
2178
2179 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2180         int flags, const char *dev_name, void *raw_data)
2181 {
2182         struct nfs_server *server = NULL;
2183         struct super_block *s;
2184         struct nfs_parsed_mount_data *data;
2185         struct nfs_fh *mntfh;
2186         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2187         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2188         struct nfs_sb_mountdata sb_mntdata = {
2189                 .mntflags = flags,
2190         };
2191         int error;
2192
2193         data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2194         mntfh = nfs_alloc_fhandle();
2195         if (data == NULL || mntfh == NULL)
2196                 goto out_free_fh;
2197
2198         security_init_mnt_opts(&data->lsm_opts);
2199
2200         /* Validate the mount data */
2201         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2202         if (error < 0) {
2203                 mntroot = ERR_PTR(error);
2204                 goto out;
2205         }
2206
2207 #ifdef CONFIG_NFS_V4
2208         if (data->version == 4) {
2209                 mntroot = nfs4_try_mount(flags, dev_name, data);
2210                 kfree(data->client_address);
2211                 kfree(data->nfs_server.export_path);
2212                 goto out;
2213         }
2214 #endif  /* CONFIG_NFS_V4 */
2215
2216         /* Get a volume representation */
2217         server = nfs_create_server(data, mntfh);
2218         if (IS_ERR(server)) {
2219                 mntroot = ERR_CAST(server);
2220                 goto out;
2221         }
2222         sb_mntdata.server = server;
2223
2224         if (server->flags & NFS_MOUNT_UNSHARED)
2225                 compare_super = NULL;
2226
2227         /* Get a superblock - note that we may end up sharing one that already exists */
2228         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2229         if (IS_ERR(s)) {
2230                 mntroot = ERR_CAST(s);
2231                 goto out_err_nosb;
2232         }
2233
2234         if (s->s_fs_info != server) {
2235                 nfs_free_server(server);
2236                 server = NULL;
2237         } else {
2238                 error = nfs_bdi_register(server);
2239                 if (error) {
2240                         mntroot = ERR_PTR(error);
2241                         goto error_splat_bdi;
2242                 }
2243         }
2244
2245         if (!s->s_root) {
2246                 /* initial superblock/root creation */
2247                 nfs_fill_super(s, data);
2248                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2249         }
2250
2251         mntroot = nfs_get_root(s, mntfh, dev_name);
2252         if (IS_ERR(mntroot))
2253                 goto error_splat_super;
2254
2255         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2256         if (error)
2257                 goto error_splat_root;
2258
2259         s->s_flags |= MS_ACTIVE;
2260
2261 out:
2262         kfree(data->nfs_server.hostname);
2263         kfree(data->mount_server.hostname);
2264         kfree(data->fscache_uniq);
2265         security_free_mnt_opts(&data->lsm_opts);
2266 out_free_fh:
2267         nfs_free_fhandle(mntfh);
2268         kfree(data);
2269         return mntroot;
2270
2271 out_err_nosb:
2272         nfs_free_server(server);
2273         goto out;
2274
2275 error_splat_root:
2276         dput(mntroot);
2277         mntroot = ERR_PTR(error);
2278 error_splat_super:
2279         if (server && !s->s_root)
2280                 bdi_unregister(&server->backing_dev_info);
2281 error_splat_bdi:
2282         deactivate_locked_super(s);
2283         goto out;
2284 }
2285
2286 /*
2287  * Ensure that we unregister the bdi before kill_anon_super
2288  * releases the device name
2289  */
2290 static void nfs_put_super(struct super_block *s)
2291 {
2292         struct nfs_server *server = NFS_SB(s);
2293
2294         bdi_unregister(&server->backing_dev_info);
2295 }
2296
2297 /*
2298  * Destroy an NFS2/3 superblock
2299  */
2300 static void nfs_kill_super(struct super_block *s)
2301 {
2302         struct nfs_server *server = NFS_SB(s);
2303
2304         kill_anon_super(s);
2305         nfs_fscache_release_super_cookie(s);
2306         nfs_free_server(server);
2307 }
2308
2309 /*
2310  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2311  */
2312 static struct dentry *
2313 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2314                 const char *dev_name, void *raw_data)
2315 {
2316         struct nfs_clone_mount *data = raw_data;
2317         struct super_block *s;
2318         struct nfs_server *server;
2319         struct dentry *mntroot;
2320         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2321         struct nfs_sb_mountdata sb_mntdata = {
2322                 .mntflags = flags,
2323         };
2324         int error;
2325
2326         dprintk("--> nfs_xdev_mount()\n");
2327
2328         /* create a new volume representation */
2329         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2330         if (IS_ERR(server)) {
2331                 error = PTR_ERR(server);
2332                 goto out_err_noserver;
2333         }
2334         sb_mntdata.server = server;
2335
2336         if (server->flags & NFS_MOUNT_UNSHARED)
2337                 compare_super = NULL;
2338
2339         /* Get a superblock - note that we may end up sharing one that already exists */
2340         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2341         if (IS_ERR(s)) {
2342                 error = PTR_ERR(s);
2343                 goto out_err_nosb;
2344         }
2345
2346         if (s->s_fs_info != server) {
2347                 nfs_free_server(server);
2348                 server = NULL;
2349         } else {
2350                 error = nfs_bdi_register(server);
2351                 if (error)
2352                         goto error_splat_bdi;
2353         }
2354
2355         if (!s->s_root) {
2356                 /* initial superblock/root creation */
2357                 nfs_clone_super(s, data->sb);
2358                 nfs_fscache_get_super_cookie(s, NULL, data);
2359         }
2360
2361         mntroot = nfs_get_root(s, data->fh, dev_name);
2362         if (IS_ERR(mntroot)) {
2363                 error = PTR_ERR(mntroot);
2364                 goto error_splat_super;
2365         }
2366         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2367                 dput(mntroot);
2368                 error = -ESTALE;
2369                 goto error_splat_super;
2370         }
2371
2372         s->s_flags |= MS_ACTIVE;
2373
2374         /* clone any lsm security options from the parent to the new sb */
2375         security_sb_clone_mnt_opts(data->sb, s);
2376
2377         dprintk("<-- nfs_xdev_mount() = 0\n");
2378         return mntroot;
2379
2380 out_err_nosb:
2381         nfs_free_server(server);
2382 out_err_noserver:
2383         dprintk("<-- nfs_xdev_mount() = %d [error]\n", error);
2384         return ERR_PTR(error);
2385
2386 error_splat_super:
2387         if (server && !s->s_root)
2388                 bdi_unregister(&server->backing_dev_info);
2389 error_splat_bdi:
2390         deactivate_locked_super(s);
2391         dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error);
2392         return ERR_PTR(error);
2393 }
2394
2395 #ifdef CONFIG_NFS_V4
2396
2397 /*
2398  * Finish setting up a cloned NFS4 superblock
2399  */
2400 static void nfs4_clone_super(struct super_block *sb,
2401                             const struct super_block *old_sb)
2402 {
2403         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2404         sb->s_blocksize = old_sb->s_blocksize;
2405         sb->s_maxbytes = old_sb->s_maxbytes;
2406         sb->s_time_gran = 1;
2407         sb->s_op = old_sb->s_op;
2408         /*
2409          * The VFS shouldn't apply the umask to mode bits. We will do
2410          * so ourselves when necessary.
2411          */
2412         sb->s_flags  |= MS_POSIXACL;
2413         sb->s_xattr  = old_sb->s_xattr;
2414         nfs_initialise_sb(sb);
2415 }
2416
2417 /*
2418  * Set up an NFS4 superblock
2419  */
2420 static void nfs4_fill_super(struct super_block *sb)
2421 {
2422         sb->s_time_gran = 1;
2423         sb->s_op = &nfs4_sops;
2424         /*
2425          * The VFS shouldn't apply the umask to mode bits. We will do
2426          * so ourselves when necessary.
2427          */
2428         sb->s_flags  |= MS_POSIXACL;
2429         sb->s_xattr = nfs4_xattr_handlers;
2430         nfs_initialise_sb(sb);
2431 }
2432
2433 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2434 {
2435         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2436                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
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 struct dentry *
2575 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2576                   const char *dev_name, void *raw_data)
2577 {
2578         struct nfs_parsed_mount_data *data = raw_data;
2579         struct super_block *s;
2580         struct nfs_server *server;
2581         struct nfs_fh *mntfh;
2582         struct dentry *mntroot;
2583         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2584         struct nfs_sb_mountdata sb_mntdata = {
2585                 .mntflags = flags,
2586         };
2587         int error = -ENOMEM;
2588
2589         mntfh = nfs_alloc_fhandle();
2590         if (data == NULL || mntfh == NULL)
2591                 goto out_free_fh;
2592
2593         security_init_mnt_opts(&data->lsm_opts);
2594
2595         /* Get a volume representation */
2596         server = nfs4_create_server(data, mntfh);
2597         if (IS_ERR(server)) {
2598                 error = PTR_ERR(server);
2599                 goto out;
2600         }
2601         sb_mntdata.server = server;
2602
2603         if (server->flags & NFS4_MOUNT_UNSHARED)
2604                 compare_super = NULL;
2605
2606         /* Get a superblock - note that we may end up sharing one that already exists */
2607         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2608         if (IS_ERR(s)) {
2609                 error = PTR_ERR(s);
2610                 goto out_free;
2611         }
2612
2613         if (s->s_fs_info != server) {
2614                 nfs_free_server(server);
2615                 server = NULL;
2616         } else {
2617                 error = nfs_bdi_register(server);
2618                 if (error)
2619                         goto error_splat_bdi;
2620         }
2621
2622         if (!s->s_root) {
2623                 /* initial superblock/root creation */
2624                 nfs4_fill_super(s);
2625                 nfs_fscache_get_super_cookie(
2626                         s, data ? data->fscache_uniq : NULL, NULL);
2627         }
2628
2629         mntroot = nfs4_get_root(s, mntfh, dev_name);
2630         if (IS_ERR(mntroot)) {
2631                 error = PTR_ERR(mntroot);
2632                 goto error_splat_super;
2633         }
2634
2635         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2636         if (error)
2637                 goto error_splat_root;
2638
2639         s->s_flags |= MS_ACTIVE;
2640
2641         security_free_mnt_opts(&data->lsm_opts);
2642         nfs_free_fhandle(mntfh);
2643         return mntroot;
2644
2645 out:
2646         security_free_mnt_opts(&data->lsm_opts);
2647 out_free_fh:
2648         nfs_free_fhandle(mntfh);
2649         return ERR_PTR(error);
2650
2651 out_free:
2652         nfs_free_server(server);
2653         goto out;
2654
2655 error_splat_root:
2656         dput(mntroot);
2657 error_splat_super:
2658         if (server && !s->s_root)
2659                 bdi_unregister(&server->backing_dev_info);
2660 error_splat_bdi:
2661         deactivate_locked_super(s);
2662         goto out;
2663 }
2664
2665 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2666                 int flags, void *data, const char *hostname)
2667 {
2668         struct vfsmount *root_mnt;
2669         char *root_devname;
2670         size_t len;
2671
2672         len = strlen(hostname) + 3;
2673         root_devname = kmalloc(len, GFP_KERNEL);
2674         if (root_devname == NULL)
2675                 return ERR_PTR(-ENOMEM);
2676         snprintf(root_devname, len, "%s:/", hostname);
2677         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2678         kfree(root_devname);
2679         return root_mnt;
2680 }
2681
2682 struct nfs_referral_count {
2683         struct list_head list;
2684         const struct task_struct *task;
2685         unsigned int referral_count;
2686 };
2687
2688 static LIST_HEAD(nfs_referral_count_list);
2689 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2690
2691 static struct nfs_referral_count *nfs_find_referral_count(void)
2692 {
2693         struct nfs_referral_count *p;
2694
2695         list_for_each_entry(p, &nfs_referral_count_list, list) {
2696                 if (p->task == current)
2697                         return p;
2698         }
2699         return NULL;
2700 }
2701
2702 #define NFS_MAX_NESTED_REFERRALS 2
2703
2704 static int nfs_referral_loop_protect(void)
2705 {
2706         struct nfs_referral_count *p, *new;
2707         int ret = -ENOMEM;
2708
2709         new = kmalloc(sizeof(*new), GFP_KERNEL);
2710         if (!new)
2711                 goto out;
2712         new->task = current;
2713         new->referral_count = 1;
2714
2715         ret = 0;
2716         spin_lock(&nfs_referral_count_list_lock);
2717         p = nfs_find_referral_count();
2718         if (p != NULL) {
2719                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2720                         ret = -ELOOP;
2721                 else
2722                         p->referral_count++;
2723         } else {
2724                 list_add(&new->list, &nfs_referral_count_list);
2725                 new = NULL;
2726         }
2727         spin_unlock(&nfs_referral_count_list_lock);
2728         kfree(new);
2729 out:
2730         return ret;
2731 }
2732
2733 static void nfs_referral_loop_unprotect(void)
2734 {
2735         struct nfs_referral_count *p;
2736
2737         spin_lock(&nfs_referral_count_list_lock);
2738         p = nfs_find_referral_count();
2739         p->referral_count--;
2740         if (p->referral_count == 0)
2741                 list_del(&p->list);
2742         else
2743                 p = NULL;
2744         spin_unlock(&nfs_referral_count_list_lock);
2745         kfree(p);
2746 }
2747
2748 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2749                 const char *export_path)
2750 {
2751         struct nameidata *nd = NULL;
2752         struct mnt_namespace *ns_private;
2753         struct super_block *s;
2754         struct dentry *dentry;
2755         int ret;
2756
2757         nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2758         if (nd == NULL)
2759                 return ERR_PTR(-ENOMEM);
2760
2761         ns_private = create_mnt_ns(root_mnt);
2762         ret = PTR_ERR(ns_private);
2763         if (IS_ERR(ns_private))
2764                 goto out_mntput;
2765
2766         ret = nfs_referral_loop_protect();
2767         if (ret != 0)
2768                 goto out_put_mnt_ns;
2769
2770         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2771                         export_path, LOOKUP_FOLLOW, nd);
2772
2773         nfs_referral_loop_unprotect();
2774         put_mnt_ns(ns_private);
2775
2776         if (ret != 0)
2777                 goto out_err;
2778
2779         s = nd->path.mnt->mnt_sb;
2780         atomic_inc(&s->s_active);
2781         dentry = dget(nd->path.dentry);
2782
2783         path_put(&nd->path);
2784         kfree(nd);
2785         down_write(&s->s_umount);
2786         return dentry;
2787 out_put_mnt_ns:
2788         put_mnt_ns(ns_private);
2789 out_mntput:
2790         mntput(root_mnt);
2791 out_err:
2792         kfree(nd);
2793         return ERR_PTR(ret);
2794 }
2795
2796 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2797                          struct nfs_parsed_mount_data *data)
2798 {
2799         char *export_path;
2800         struct vfsmount *root_mnt;
2801         struct dentry *res;
2802
2803         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2804
2805         export_path = data->nfs_server.export_path;
2806         data->nfs_server.export_path = "/";
2807         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2808                         data->nfs_server.hostname);
2809         data->nfs_server.export_path = export_path;
2810
2811         res = ERR_CAST(root_mnt);
2812         if (!IS_ERR(root_mnt))
2813                 res = nfs_follow_remote_path(root_mnt, export_path);
2814
2815         dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2816                         IS_ERR(res) ? PTR_ERR(res) : 0,
2817                         IS_ERR(res) ? " [error]" : "");
2818         return res;
2819 }
2820
2821 /*
2822  * Get the superblock for an NFS4 mountpoint
2823  */
2824 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2825         int flags, const char *dev_name, void *raw_data)
2826 {
2827         struct nfs_parsed_mount_data *data;
2828         int error = -ENOMEM;
2829         struct dentry *res = ERR_PTR(-ENOMEM);
2830
2831         data = nfs_alloc_parsed_mount_data(4);
2832         if (data == NULL)
2833                 goto out_free_data;
2834
2835         /* Validate the mount data */
2836         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2837         if (error < 0) {
2838                 res = ERR_PTR(error);
2839                 goto out;
2840         }
2841
2842         res = nfs4_try_mount(flags, dev_name, data);
2843         if (IS_ERR(res))
2844                 error = PTR_ERR(res);
2845
2846 out:
2847         kfree(data->client_address);
2848         kfree(data->nfs_server.export_path);
2849         kfree(data->nfs_server.hostname);
2850         kfree(data->fscache_uniq);
2851 out_free_data:
2852         kfree(data);
2853         dprintk("<-- nfs4_mount() = %d%s\n", error,
2854                         error != 0 ? " [error]" : "");
2855         return res;
2856 }
2857
2858 static void nfs4_kill_super(struct super_block *sb)
2859 {
2860         struct nfs_server *server = NFS_SB(sb);
2861
2862         dprintk("--> %s\n", __func__);
2863         nfs_super_return_all_delegations(sb);
2864         kill_anon_super(sb);
2865         nfs_fscache_release_super_cookie(sb);
2866         nfs_free_server(server);
2867         dprintk("<-- %s\n", __func__);
2868 }
2869
2870 /*
2871  * Clone an NFS4 server record on xdev traversal (FSID-change)
2872  */
2873 static struct dentry *
2874 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2875                  const char *dev_name, void *raw_data)
2876 {
2877         struct nfs_clone_mount *data = raw_data;
2878         struct super_block *s;
2879         struct nfs_server *server;
2880         struct dentry *mntroot;
2881         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2882         struct nfs_sb_mountdata sb_mntdata = {
2883                 .mntflags = flags,
2884         };
2885         int error;
2886
2887         dprintk("--> nfs4_xdev_mount()\n");
2888
2889         /* create a new volume representation */
2890         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2891         if (IS_ERR(server)) {
2892                 error = PTR_ERR(server);
2893                 goto out_err_noserver;
2894         }
2895         sb_mntdata.server = server;
2896
2897         if (server->flags & NFS4_MOUNT_UNSHARED)
2898                 compare_super = NULL;
2899
2900         /* Get a superblock - note that we may end up sharing one that already exists */
2901         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2902         if (IS_ERR(s)) {
2903                 error = PTR_ERR(s);
2904                 goto out_err_nosb;
2905         }
2906
2907         if (s->s_fs_info != server) {
2908                 nfs_free_server(server);
2909                 server = NULL;
2910         } else {
2911                 error = nfs_bdi_register(server);
2912                 if (error)
2913                         goto error_splat_bdi;
2914         }
2915
2916         if (!s->s_root) {
2917                 /* initial superblock/root creation */
2918                 nfs4_clone_super(s, data->sb);
2919                 nfs_fscache_get_super_cookie(s, NULL, data);
2920         }
2921
2922         mntroot = nfs4_get_root(s, data->fh, dev_name);
2923         if (IS_ERR(mntroot)) {
2924                 error = PTR_ERR(mntroot);
2925                 goto error_splat_super;
2926         }
2927         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2928                 dput(mntroot);
2929                 error = -ESTALE;
2930                 goto error_splat_super;
2931         }
2932
2933         s->s_flags |= MS_ACTIVE;
2934
2935         security_sb_clone_mnt_opts(data->sb, s);
2936
2937         dprintk("<-- nfs4_xdev_mount() = 0\n");
2938         return mntroot;
2939
2940 out_err_nosb:
2941         nfs_free_server(server);
2942 out_err_noserver:
2943         dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error);
2944         return ERR_PTR(error);
2945
2946 error_splat_super:
2947         if (server && !s->s_root)
2948                 bdi_unregister(&server->backing_dev_info);
2949 error_splat_bdi:
2950         deactivate_locked_super(s);
2951         dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error);
2952         return ERR_PTR(error);
2953 }
2954
2955 static struct dentry *
2956 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2957                            const char *dev_name, void *raw_data)
2958 {
2959         struct nfs_clone_mount *data = raw_data;
2960         struct super_block *s;
2961         struct nfs_server *server;
2962         struct dentry *mntroot;
2963         struct nfs_fh *mntfh;
2964         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2965         struct nfs_sb_mountdata sb_mntdata = {
2966                 .mntflags = flags,
2967         };
2968         int error = -ENOMEM;
2969
2970         dprintk("--> nfs4_referral_get_sb()\n");
2971
2972         mntfh = nfs_alloc_fhandle();
2973         if (mntfh == NULL)
2974                 goto out_err_nofh;
2975
2976         /* create a new volume representation */
2977         server = nfs4_create_referral_server(data, mntfh);
2978         if (IS_ERR(server)) {
2979                 error = PTR_ERR(server);
2980                 goto out_err_noserver;
2981         }
2982         sb_mntdata.server = server;
2983
2984         if (server->flags & NFS4_MOUNT_UNSHARED)
2985                 compare_super = NULL;
2986
2987         /* Get a superblock - note that we may end up sharing one that already exists */
2988         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2989         if (IS_ERR(s)) {
2990                 error = PTR_ERR(s);
2991                 goto out_err_nosb;
2992         }
2993
2994         if (s->s_fs_info != server) {
2995                 nfs_free_server(server);
2996                 server = NULL;
2997         } else {
2998                 error = nfs_bdi_register(server);
2999                 if (error)
3000                         goto error_splat_bdi;
3001         }
3002
3003         if (!s->s_root) {
3004                 /* initial superblock/root creation */
3005                 nfs4_fill_super(s);
3006                 nfs_fscache_get_super_cookie(s, NULL, data);
3007         }
3008
3009         mntroot = nfs4_get_root(s, mntfh, dev_name);
3010         if (IS_ERR(mntroot)) {
3011                 error = PTR_ERR(mntroot);
3012                 goto error_splat_super;
3013         }
3014         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3015                 dput(mntroot);
3016                 error = -ESTALE;
3017                 goto error_splat_super;
3018         }
3019
3020         s->s_flags |= MS_ACTIVE;
3021
3022         security_sb_clone_mnt_opts(data->sb, s);
3023
3024         nfs_free_fhandle(mntfh);
3025         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3026         return mntroot;
3027
3028 out_err_nosb:
3029         nfs_free_server(server);
3030 out_err_noserver:
3031         nfs_free_fhandle(mntfh);
3032 out_err_nofh:
3033         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3034         return ERR_PTR(error);
3035
3036 error_splat_super:
3037         if (server && !s->s_root)
3038                 bdi_unregister(&server->backing_dev_info);
3039 error_splat_bdi:
3040         deactivate_locked_super(s);
3041         nfs_free_fhandle(mntfh);
3042         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3043         return ERR_PTR(error);
3044 }
3045
3046 /*
3047  * Create an NFS4 server record on referral traversal
3048  */
3049 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3050                 int flags, const char *dev_name, void *raw_data)
3051 {
3052         struct nfs_clone_mount *data = raw_data;
3053         char *export_path;
3054         struct vfsmount *root_mnt;
3055         struct dentry *res;
3056
3057         dprintk("--> nfs4_referral_mount()\n");
3058
3059         export_path = data->mnt_path;
3060         data->mnt_path = "/";
3061
3062         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3063                         flags, data, data->hostname);
3064         data->mnt_path = export_path;
3065
3066         res = ERR_CAST(root_mnt);
3067         if (!IS_ERR(root_mnt))
3068                 res = nfs_follow_remote_path(root_mnt, export_path);
3069         dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3070                         IS_ERR(res) ? PTR_ERR(res) : 0,
3071                         IS_ERR(res) ? " [error]" : "");
3072         return res;
3073 }
3074
3075 #endif /* CONFIG_NFS_V4 */