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/namei.h>
  45 #include <linux/nfs_idmap.h>
  46 #include <linux/vfs.h>
  47 #include <linux/inet.h>
  48 #include <linux/in6.h>
  49 #include <linux/slab.h>
  50 #include <net/ipv6.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/nfs_xdr.h>
  53 #include <linux/magic.h>
  54 #include <linux/parser.h>
  55 #include <linux/nsproxy.h>
  56 #include <linux/rcupdate.h>
  57
  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 #include "pnfs.h"
  67
  68 #define NFSDBG_FACILITY         NFSDBG_VFS
  69
  70 #ifdef CONFIG_NFS_V3
  71 #define NFS_DEFAULT_VERSION 3
  72 #else
  73 #define NFS_DEFAULT_VERSION 2
  74 #endif
  75
  76 enum {
  77         /* Mount options that take no arguments */
  78         Opt_soft, Opt_hard,
  79         Opt_posix, Opt_noposix,
  80         Opt_cto, Opt_nocto,
  81         Opt_ac, Opt_noac,
  82         Opt_lock, Opt_nolock,
  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_minorversion,
 101
 102         /* Mount options that take string arguments */
 103         Opt_nfsvers,
 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_udp, "udp" },
 136         { Opt_tcp, "tcp" },
 137         { Opt_rdma, "rdma" },
 138         { Opt_acl, "acl" },
 139         { Opt_noacl, "noacl" },
 140         { Opt_rdirplus, "rdirplus" },
 141         { Opt_nordirplus, "nordirplus" },
 142         { Opt_sharecache, "sharecache" },
 143         { Opt_nosharecache, "nosharecache" },
 144         { Opt_resvport, "resvport" },
 145         { Opt_noresvport, "noresvport" },
 146         { Opt_fscache, "fsc" },
 147         { Opt_nofscache, "nofsc" },
 148
 149         { Opt_port, "port=%s" },
 150         { Opt_rsize, "rsize=%s" },
 151         { Opt_wsize, "wsize=%s" },
 152         { Opt_bsize, "bsize=%s" },
 153         { Opt_timeo, "timeo=%s" },
 154         { Opt_retrans, "retrans=%s" },
 155         { Opt_acregmin, "acregmin=%s" },
 156         { Opt_acregmax, "acregmax=%s" },
 157         { Opt_acdirmin, "acdirmin=%s" },
 158         { Opt_acdirmax, "acdirmax=%s" },
 159         { Opt_actimeo, "actimeo=%s" },
 160         { Opt_namelen, "namlen=%s" },
 161         { Opt_mountport, "mountport=%s" },
 162         { Opt_mountvers, "mountvers=%s" },
 163         { Opt_minorversion, "minorversion=%s" },
 164
 165         { Opt_nfsvers, "nfsvers=%s" },
 166         { Opt_nfsvers, "vers=%s" },
 167
 168         { Opt_sec, "sec=%s" },
 169         { Opt_proto, "proto=%s" },
 170         { Opt_mountproto, "mountproto=%s" },
 171         { Opt_addr, "addr=%s" },
 172         { Opt_clientaddr, "clientaddr=%s" },
 173         { Opt_mounthost, "mounthost=%s" },
 174         { Opt_mountaddr, "mountaddr=%s" },
 175
 176         { Opt_lookupcache, "lookupcache=%s" },
 177         { Opt_fscache_uniq, "fsc=%s" },
 178         { Opt_local_lock, "local_lock=%s" },
 179
 180         /* The following needs to be listed after all other options */
 181         { Opt_nfsvers, "v%s" },
 182
 183         { Opt_err, NULL }
 184 };
 185
 186 enum {
 187         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 188
 189         Opt_xprt_err
 190 };
 191
 192 static const match_table_t nfs_xprt_protocol_tokens = {
 193         { Opt_xprt_udp, "udp" },
 194         { Opt_xprt_udp6, "udp6" },
 195         { Opt_xprt_tcp, "tcp" },
 196         { Opt_xprt_tcp6, "tcp6" },
 197         { Opt_xprt_rdma, "rdma" },
 198
 199         { Opt_xprt_err, NULL }
 200 };
 201
 202 enum {
 203         Opt_sec_none, Opt_sec_sys,
 204         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 205         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 206         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 207
 208         Opt_sec_err
 209 };
 210
 211 static const match_table_t nfs_secflavor_tokens = {
 212         { Opt_sec_none, "none" },
 213         { Opt_sec_none, "null" },
 214         { Opt_sec_sys, "sys" },
 215
 216         { Opt_sec_krb5, "krb5" },
 217         { Opt_sec_krb5i, "krb5i" },
 218         { Opt_sec_krb5p, "krb5p" },
 219
 220         { Opt_sec_lkey, "lkey" },
 221         { Opt_sec_lkeyi, "lkeyi" },
 222         { Opt_sec_lkeyp, "lkeyp" },
 223
 224         { Opt_sec_spkm, "spkm3" },
 225         { Opt_sec_spkmi, "spkm3i" },
 226         { Opt_sec_spkmp, "spkm3p" },
 227
 228         { Opt_sec_err, NULL }
 229 };
 230
 231 enum {
 232         Opt_lookupcache_all, Opt_lookupcache_positive,
 233         Opt_lookupcache_none,
 234
 235         Opt_lookupcache_err
 236 };
 237
 238 static match_table_t nfs_lookupcache_tokens = {
 239         { Opt_lookupcache_all, "all" },
 240         { Opt_lookupcache_positive, "pos" },
 241         { Opt_lookupcache_positive, "positive" },
 242         { Opt_lookupcache_none, "none" },
 243
 244         { Opt_lookupcache_err, NULL }
 245 };
 246
 247 enum {
 248         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 249         Opt_local_lock_none,
 250
 251         Opt_local_lock_err
 252 };
 253
 254 static match_table_t nfs_local_lock_tokens = {
 255         { Opt_local_lock_all, "all" },
 256         { Opt_local_lock_flock, "flock" },
 257         { Opt_local_lock_posix, "posix" },
 258         { Opt_local_lock_none, "none" },
 259
 260         { Opt_local_lock_err, NULL }
 261 };
 262
 263 enum {
 264         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 265         Opt_vers_4_1,
 266
 267         Opt_vers_err
 268 };
 269
 270 static match_table_t nfs_vers_tokens = {
 271         { Opt_vers_2, "2" },
 272         { Opt_vers_3, "3" },
 273         { Opt_vers_4, "4" },
 274         { Opt_vers_4_0, "4.0" },
 275         { Opt_vers_4_1, "4.1" },
 276
 277         { Opt_vers_err, NULL }
 278 };
 279
 280 struct nfs_mount_info {
 281         void (*fill_super)(struct super_block *, struct nfs_mount_info *);
 282         int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
 283         struct nfs_parsed_mount_data *parsed;
 284         struct nfs_clone_mount *cloned;
 285 };
 286
 287 static void nfs_umount_begin(struct super_block *);
 288 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 289 static int  nfs_show_options(struct seq_file *, struct dentry *);
 290 static int  nfs_show_devname(struct seq_file *, struct dentry *);
 291 static int  nfs_show_path(struct seq_file *, struct dentry *);
 292 static int  nfs_show_stats(struct seq_file *, struct dentry *);
 293 static struct dentry *nfs_fs_mount(struct file_system_type *,
 294                 int, const char *, void *);
 295 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 296                 int flags, const char *dev_name, void *raw_data);
 297 static void nfs_put_super(struct super_block *);
 298 static void nfs_kill_super(struct super_block *);
 299 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 300
 301 static struct file_system_type nfs_fs_type = {
 302         .owner          = THIS_MODULE,
 303         .name           = "nfs",
 304         .mount          = nfs_fs_mount,
 305         .kill_sb        = nfs_kill_super,
 306         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 307 };
 308
 309 struct file_system_type nfs_xdev_fs_type = {
 310         .owner          = THIS_MODULE,
 311         .name           = "nfs",
 312         .mount          = nfs_xdev_mount,
 313         .kill_sb        = nfs_kill_super,
 314         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 315 };
 316
 317 static const struct super_operations nfs_sops = {
 318         .alloc_inode    = nfs_alloc_inode,
 319         .destroy_inode  = nfs_destroy_inode,
 320         .write_inode    = nfs_write_inode,
 321         .put_super      = nfs_put_super,
 322         .statfs         = nfs_statfs,
 323         .evict_inode    = nfs_evict_inode,
 324         .umount_begin   = nfs_umount_begin,
 325         .show_options   = nfs_show_options,
 326         .show_devname   = nfs_show_devname,
 327         .show_path      = nfs_show_path,
 328         .show_stats     = nfs_show_stats,
 329         .remount_fs     = nfs_remount,
 330 };
 331
 332 #ifdef CONFIG_NFS_V4
 333 static int nfs4_validate_text_mount_data(void *options,
 334         struct nfs_parsed_mount_data *args, const char *dev_name);
 335 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 336         struct nfs_parsed_mount_data *data);
 337 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
 338         int flags, const char *dev_name, void *raw_data);
 339 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 340         int flags, const char *dev_name, void *raw_data);
 341 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
 342         int flags, const char *dev_name, void *raw_data);
 343 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 344         int flags, const char *dev_name, void *raw_data);
 345 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 346         int flags, const char *dev_name, void *raw_data);
 347 static void nfs4_kill_super(struct super_block *sb);
 348
 349 static struct file_system_type nfs4_fs_type = {
 350         .owner          = THIS_MODULE,
 351         .name           = "nfs4",
 352         .mount          = nfs4_mount,
 353         .kill_sb        = nfs4_kill_super,
 354         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 355 };
 356
 357 static struct file_system_type nfs4_remote_fs_type = {
 358         .owner          = THIS_MODULE,
 359         .name           = "nfs4",
 360         .mount          = nfs4_remote_mount,
 361         .kill_sb        = nfs4_kill_super,
 362         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 363 };
 364
 365 struct file_system_type nfs4_xdev_fs_type = {
 366         .owner          = THIS_MODULE,
 367         .name           = "nfs4",
 368         .mount          = nfs4_xdev_mount,
 369         .kill_sb        = nfs4_kill_super,
 370         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 371 };
 372
 373 static struct file_system_type nfs4_remote_referral_fs_type = {
 374         .owner          = THIS_MODULE,
 375         .name           = "nfs4",
 376         .mount          = nfs4_remote_referral_mount,
 377         .kill_sb        = nfs4_kill_super,
 378         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 379 };
 380
 381 struct file_system_type nfs4_referral_fs_type = {
 382         .owner          = THIS_MODULE,
 383         .name           = "nfs4",
 384         .mount          = nfs4_referral_mount,
 385         .kill_sb        = nfs4_kill_super,
 386         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 387 };
 388
 389 static const struct super_operations nfs4_sops = {
 390         .alloc_inode    = nfs_alloc_inode,
 391         .destroy_inode  = nfs_destroy_inode,
 392         .write_inode    = nfs_write_inode,
 393         .put_super      = nfs_put_super,
 394         .statfs         = nfs_statfs,
 395         .evict_inode    = nfs4_evict_inode,
 396         .umount_begin   = nfs_umount_begin,
 397         .show_options   = nfs_show_options,
 398         .show_devname   = nfs_show_devname,
 399         .show_path      = nfs_show_path,
 400         .show_stats     = nfs_show_stats,
 401         .remount_fs     = nfs_remount,
 402 };
 403 #endif
 404
 405 static struct shrinker acl_shrinker = {
 406         .shrink         = nfs_access_cache_shrinker,
 407         .seeks          = DEFAULT_SEEKS,
 408 };
 409
 410 /*
 411  * Register the NFS filesystems
 412  */
 413 int __init register_nfs_fs(void)
 414 {
 415         int ret;
 416
 417         ret = register_filesystem(&nfs_fs_type);
 418         if (ret < 0)
 419                 goto error_0;
 420
 421         ret = nfs_register_sysctl();
 422         if (ret < 0)
 423                 goto error_1;
 424 #ifdef CONFIG_NFS_V4
 425         ret = register_filesystem(&nfs4_fs_type);
 426         if (ret < 0)
 427                 goto error_2;
 428 #endif
 429         register_shrinker(&acl_shrinker);
 430         return 0;
 431
 432 #ifdef CONFIG_NFS_V4
 433 error_2:
 434         nfs_unregister_sysctl();
 435 #endif
 436 error_1:
 437         unregister_filesystem(&nfs_fs_type);
 438 error_0:
 439         return ret;
 440 }
 441
 442 /*
 443  * Unregister the NFS filesystems
 444  */
 445 void __exit unregister_nfs_fs(void)
 446 {
 447         unregister_shrinker(&acl_shrinker);
 448 #ifdef CONFIG_NFS_V4
 449         unregister_filesystem(&nfs4_fs_type);
 450 #endif
 451         nfs_unregister_sysctl();
 452         unregister_filesystem(&nfs_fs_type);
 453 }
 454
 455 void nfs_sb_active(struct super_block *sb)
 456 {
 457         struct nfs_server *server = NFS_SB(sb);
 458
 459         if (atomic_inc_return(&server->active) == 1)
 460                 atomic_inc(&sb->s_active);
 461 }
 462
 463 void nfs_sb_deactive(struct super_block *sb)
 464 {
 465         struct nfs_server *server = NFS_SB(sb);
 466
 467         if (atomic_dec_and_test(&server->active))
 468                 deactivate_super(sb);
 469 }
 470
 471 /*
 472  * Deliver file system statistics to userspace
 473  */
 474 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 475 {
 476         struct nfs_server *server = NFS_SB(dentry->d_sb);
 477         unsigned char blockbits;
 478         unsigned long blockres;
 479         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 480         struct nfs_fsstat res;
 481         int error = -ENOMEM;
 482
 483         res.fattr = nfs_alloc_fattr();
 484         if (res.fattr == NULL)
 485                 goto out_err;
 486
 487         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 488         if (unlikely(error == -ESTALE)) {
 489                 struct dentry *pd_dentry;
 490
 491                 pd_dentry = dget_parent(dentry);
 492                 if (pd_dentry != NULL) {
 493                         nfs_zap_caches(pd_dentry->d_inode);
 494                         dput(pd_dentry);
 495                 }
 496         }
 497         nfs_free_fattr(res.fattr);
 498         if (error < 0)
 499                 goto out_err;
 500
 501         buf->f_type = NFS_SUPER_MAGIC;
 502
 503         /*
 504          * Current versions of glibc do not correctly handle the
 505          * case where f_frsize != f_bsize.  Eventually we want to
 506          * report the value of wtmult in this field.
 507          */
 508         buf->f_frsize = dentry->d_sb->s_blocksize;
 509
 510         /*
 511          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 512          * are reported in units of f_frsize.  Linux hasn't had
 513          * an f_frsize field in its statfs struct until recently,
 514          * thus historically Linux's sys_statfs reports these
 515          * fields in units of f_bsize.
 516          */
 517         buf->f_bsize = dentry->d_sb->s_blocksize;
 518         blockbits = dentry->d_sb->s_blocksize_bits;
 519         blockres = (1 << blockbits) - 1;
 520         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 521         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 522         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 523
 524         buf->f_files = res.tfiles;
 525         buf->f_ffree = res.afiles;
 526
 527         buf->f_namelen = server->namelen;
 528
 529         return 0;
 530
 531  out_err:
 532         dprintk("%s: statfs error = %d\n", __func__, -error);
 533         return error;
 534 }
 535
 536 /*
 537  * Map the security flavour number to a name
 538  */
 539 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 540 {
 541         static const struct {
 542                 rpc_authflavor_t flavour;
 543                 const char *str;
 544         } sec_flavours[] = {
 545                 { RPC_AUTH_NULL, "null" },
 546                 { RPC_AUTH_UNIX, "sys" },
 547                 { RPC_AUTH_GSS_KRB5, "krb5" },
 548                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 549                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 550                 { RPC_AUTH_GSS_LKEY, "lkey" },
 551                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 552                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 553                 { RPC_AUTH_GSS_SPKM, "spkm" },
 554                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 555                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 556                 { UINT_MAX, "unknown" }
 557         };
 558         int i;
 559
 560         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 561                 if (sec_flavours[i].flavour == flavour)
 562                         break;
 563         }
 564         return sec_flavours[i].str;
 565 }
 566
 567 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 568                                   int showdefaults)
 569 {
 570         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 571
 572         seq_printf(m, ",mountproto=");
 573         switch (sap->sa_family) {
 574         case AF_INET:
 575                 switch (nfss->mountd_protocol) {
 576                 case IPPROTO_UDP:
 577                         seq_printf(m, RPCBIND_NETID_UDP);
 578                         break;
 579                 case IPPROTO_TCP:
 580                         seq_printf(m, RPCBIND_NETID_TCP);
 581                         break;
 582                 default:
 583                         if (showdefaults)
 584                                 seq_printf(m, "auto");
 585                 }
 586                 break;
 587         case AF_INET6:
 588                 switch (nfss->mountd_protocol) {
 589                 case IPPROTO_UDP:
 590                         seq_printf(m, RPCBIND_NETID_UDP6);
 591                         break;
 592                 case IPPROTO_TCP:
 593                         seq_printf(m, RPCBIND_NETID_TCP6);
 594                         break;
 595                 default:
 596                         if (showdefaults)
 597                                 seq_printf(m, "auto");
 598                 }
 599                 break;
 600         default:
 601                 if (showdefaults)
 602                         seq_printf(m, "auto");
 603         }
 604 }
 605
 606 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 607                                     int showdefaults)
 608 {
 609         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 610
 611         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 612                 return;
 613
 614         switch (sap->sa_family) {
 615         case AF_INET: {
 616                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 617                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 618                 break;
 619         }
 620         case AF_INET6: {
 621                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 622                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 623                 break;
 624         }
 625         default:
 626                 if (showdefaults)
 627                         seq_printf(m, ",mountaddr=unspecified");
 628         }
 629
 630         if (nfss->mountd_version || showdefaults)
 631                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 632         if ((nfss->mountd_port &&
 633                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 634                 showdefaults)
 635                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 636
 637         nfs_show_mountd_netid(m, nfss, showdefaults);
 638 }
 639
 640 #ifdef CONFIG_NFS_V4
 641 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 642                                     int showdefaults)
 643 {
 644         struct nfs_client *clp = nfss->nfs_client;
 645
 646         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 647 }
 648 #else
 649 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 650                                     int showdefaults)
 651 {
 652 }
 653 #endif
 654
 655 static void nfs_show_nfs_version(struct seq_file *m,
 656                 unsigned int version,
 657                 unsigned int minorversion)
 658 {
 659         seq_printf(m, ",vers=%u", version);
 660         if (version == 4)
 661                 seq_printf(m, ".%u", minorversion);
 662 }
 663
 664 /*
 665  * Describe the mount options in force on this server representation
 666  */
 667 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 668                                    int showdefaults)
 669 {
 670         static const struct proc_nfs_info {
 671                 int flag;
 672                 const char *str;
 673                 const char *nostr;
 674         } nfs_info[] = {
 675                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 676                 { NFS_MOUNT_POSIX, ",posix", "" },
 677                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 678                 { NFS_MOUNT_NOAC, ",noac", "" },
 679                 { NFS_MOUNT_NONLM, ",nolock", "" },
 680                 { NFS_MOUNT_NOACL, ",noacl", "" },
 681                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 682                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 683                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 684                 { 0, NULL, NULL }
 685         };
 686         const struct proc_nfs_info *nfs_infop;
 687         struct nfs_client *clp = nfss->nfs_client;
 688         u32 version = clp->rpc_ops->version;
 689         int local_flock, local_fcntl;
 690
 691         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 692         seq_printf(m, ",rsize=%u", nfss->rsize);
 693         seq_printf(m, ",wsize=%u", nfss->wsize);
 694         if (nfss->bsize != 0)
 695                 seq_printf(m, ",bsize=%u", nfss->bsize);
 696         seq_printf(m, ",namlen=%u", nfss->namelen);
 697         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 698                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 699         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 700                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 701         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 702                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 703         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 704                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 705         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 706                 if (nfss->flags & nfs_infop->flag)
 707                         seq_puts(m, nfs_infop->str);
 708                 else
 709                         seq_puts(m, nfs_infop->nostr);
 710         }
 711         rcu_read_lock();
 712         seq_printf(m, ",proto=%s",
 713                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 714         rcu_read_unlock();
 715         if (version == 4) {
 716                 if (nfss->port != NFS_PORT)
 717                         seq_printf(m, ",port=%u", nfss->port);
 718         } else
 719                 if (nfss->port)
 720                         seq_printf(m, ",port=%u", nfss->port);
 721
 722         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 723         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 724         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 725
 726         if (version != 4)
 727                 nfs_show_mountd_options(m, nfss, showdefaults);
 728         else
 729                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 730
 731         if (nfss->options & NFS_OPTION_FSCACHE)
 732                 seq_printf(m, ",fsc");
 733
 734         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 735                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 736                         seq_printf(m, ",lookupcache=none");
 737                 else
 738                         seq_printf(m, ",lookupcache=pos");
 739         }
 740
 741         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 742         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 743
 744         if (!local_flock && !local_fcntl)
 745                 seq_printf(m, ",local_lock=none");
 746         else if (local_flock && local_fcntl)
 747                 seq_printf(m, ",local_lock=all");
 748         else if (local_flock)
 749                 seq_printf(m, ",local_lock=flock");
 750         else
 751                 seq_printf(m, ",local_lock=posix");
 752 }
 753
 754 /*
 755  * Describe the mount options on this VFS mountpoint
 756  */
 757 static int nfs_show_options(struct seq_file *m, struct dentry *root)
 758 {
 759         struct nfs_server *nfss = NFS_SB(root->d_sb);
 760
 761         nfs_show_mount_options(m, nfss, 0);
 762
 763         rcu_read_lock();
 764         seq_printf(m, ",addr=%s",
 765                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 766                                                         RPC_DISPLAY_ADDR));
 767         rcu_read_unlock();
 768
 769         return 0;
 770 }
 771
 772 #ifdef CONFIG_NFS_V4
 773 #ifdef CONFIG_NFS_V4_1
 774 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 775 {
 776         if (nfs4_has_session(server->nfs_client))
 777                 seq_printf(m, ",sessions");
 778 }
 779 #else
 780 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 781 #endif
 782 #endif
 783
 784 #ifdef CONFIG_NFS_V4_1
 785 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 786 {
 787         seq_printf(m, ",pnfs=");
 788         if (server->pnfs_curr_ld)
 789                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 790         else
 791                 seq_printf(m, "not configured");
 792 }
 793
 794 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 795 {
 796         if (nfss->nfs_client && nfss->nfs_client->impl_id) {
 797                 struct nfs41_impl_id *impl_id = nfss->nfs_client->impl_id;
 798                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 799                            "date='%llu,%u'",
 800                            impl_id->name, impl_id->domain,
 801                            impl_id->date.seconds, impl_id->date.nseconds);
 802         }
 803 }
 804 #else
 805 #ifdef CONFIG_NFS_V4
 806 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 807 {
 808 }
 809 #endif
 810 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 811 {
 812 }
 813 #endif
 814
 815 static int nfs_show_devname(struct seq_file *m, struct dentry *root)
 816 {
 817         char *page = (char *) __get_free_page(GFP_KERNEL);
 818         char *devname, *dummy;
 819         int err = 0;
 820         if (!page)
 821                 return -ENOMEM;
 822         devname = nfs_path(&dummy, root, page, PAGE_SIZE);
 823         if (IS_ERR(devname))
 824                 err = PTR_ERR(devname);
 825         else
 826                 seq_escape(m, devname, " \t\n\\");
 827         free_page((unsigned long)page);
 828         return err;
 829 }
 830
 831 static int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 832 {
 833         seq_puts(m, "/");
 834         return 0;
 835 }
 836
 837 /*
 838  * Present statistical information for this VFS mountpoint
 839  */
 840 static int nfs_show_stats(struct seq_file *m, struct dentry *root)
 841 {
 842         int i, cpu;
 843         struct nfs_server *nfss = NFS_SB(root->d_sb);
 844         struct rpc_auth *auth = nfss->client->cl_auth;
 845         struct nfs_iostats totals = { };
 846
 847         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 848
 849         /*
 850          * Display all mount option settings
 851          */
 852         seq_printf(m, "\n\topts:\t");
 853         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 854         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 855         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 856         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 857         nfs_show_mount_options(m, nfss, 1);
 858
 859         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 860
 861         show_implementation_id(m, nfss);
 862
 863         seq_printf(m, "\n\tcaps:\t");
 864         seq_printf(m, "caps=0x%x", nfss->caps);
 865         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 866         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 867         seq_printf(m, ",bsize=%u", nfss->bsize);
 868         seq_printf(m, ",namlen=%u", nfss->namelen);
 869
 870 #ifdef CONFIG_NFS_V4
 871         if (nfss->nfs_client->rpc_ops->version == 4) {
 872                 seq_printf(m, "\n\tnfsv4:\t");
 873                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 874                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 875                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 876                 show_sessions(m, nfss);
 877                 show_pnfs(m, nfss);
 878         }
 879 #endif
 880
 881         /*
 882          * Display security flavor in effect for this mount
 883          */
 884         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 885         if (auth->au_flavor)
 886                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 887
 888         /*
 889          * Display superblock I/O counters
 890          */
 891         for_each_possible_cpu(cpu) {
 892                 struct nfs_iostats *stats;
 893
 894                 preempt_disable();
 895                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 896
 897                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 898                         totals.events[i] += stats->events[i];
 899                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 900                         totals.bytes[i] += stats->bytes[i];
 901 #ifdef CONFIG_NFS_FSCACHE
 902                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 903                         totals.fscache[i] += stats->fscache[i];
 904 #endif
 905
 906                 preempt_enable();
 907         }
 908
 909         seq_printf(m, "\n\tevents:\t");
 910         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 911                 seq_printf(m, "%lu ", totals.events[i]);
 912         seq_printf(m, "\n\tbytes:\t");
 913         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 914                 seq_printf(m, "%Lu ", totals.bytes[i]);
 915 #ifdef CONFIG_NFS_FSCACHE
 916         if (nfss->options & NFS_OPTION_FSCACHE) {
 917                 seq_printf(m, "\n\tfsc:\t");
 918                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 919                         seq_printf(m, "%Lu ", totals.bytes[i]);
 920         }
 921 #endif
 922         seq_printf(m, "\n");
 923
 924         rpc_print_iostats(m, nfss->client);
 925
 926         return 0;
 927 }
 928
 929 /*
 930  * Begin unmount by attempting to remove all automounted mountpoints we added
 931  * in response to xdev traversals and referrals
 932  */
 933 static void nfs_umount_begin(struct super_block *sb)
 934 {
 935         struct nfs_server *server;
 936         struct rpc_clnt *rpc;
 937
 938         server = NFS_SB(sb);
 939         /* -EIO all pending I/O */
 940         rpc = server->client_acl;
 941         if (!IS_ERR(rpc))
 942                 rpc_killall_tasks(rpc);
 943         rpc = server->client;
 944         if (!IS_ERR(rpc))
 945                 rpc_killall_tasks(rpc);
 946 }
 947
 948 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 949 {
 950         struct nfs_parsed_mount_data *data;
 951
 952         data = kzalloc(sizeof(*data), GFP_KERNEL);
 953         if (data) {
 954                 data->acregmin          = NFS_DEF_ACREGMIN;
 955                 data->acregmax          = NFS_DEF_ACREGMAX;
 956                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 957                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 958                 data->mount_server.port = NFS_UNSPEC_PORT;
 959                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 960                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 961                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 962                 data->auth_flavor_len   = 1;
 963                 data->version           = version;
 964                 data->minorversion      = 0;
 965                 data->net               = current->nsproxy->net_ns;
 966                 security_init_mnt_opts(&data->lsm_opts);
 967         }
 968         return data;
 969 }
 970
 971 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 972 {
 973         if (data) {
 974                 kfree(data->client_address);
 975                 kfree(data->mount_server.hostname);
 976                 kfree(data->nfs_server.export_path);
 977                 kfree(data->nfs_server.hostname);
 978                 kfree(data->fscache_uniq);
 979                 security_free_mnt_opts(&data->lsm_opts);
 980                 kfree(data);
 981         }
 982 }
 983
 984 /*
 985  * Sanity-check a server address provided by the mount command.
 986  *
 987  * Address family must be initialized, and address must not be
 988  * the ANY address for that family.
 989  */
 990 static int nfs_verify_server_address(struct sockaddr *addr)
 991 {
 992         switch (addr->sa_family) {
 993         case AF_INET: {
 994                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 995                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 996         }
 997         case AF_INET6: {
 998                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 999                 return !ipv6_addr_any(sa);
1000         }
1001         }
1002
1003         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
1004         return 0;
1005 }
1006
1007 /*
1008  * Select between a default port value and a user-specified port value.
1009  * If a zero value is set, then autobind will be used.
1010  */
1011 static void nfs_set_port(struct sockaddr *sap, int *port,
1012                                  const unsigned short default_port)
1013 {
1014         if (*port == NFS_UNSPEC_PORT)
1015                 *port = default_port;
1016
1017         rpc_set_port(sap, *port);
1018 }
1019
1020 /*
1021  * Sanity check the NFS transport protocol.
1022  *
1023  */
1024 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1025 {
1026         switch (mnt->nfs_server.protocol) {
1027         case XPRT_TRANSPORT_UDP:
1028         case XPRT_TRANSPORT_TCP:
1029         case XPRT_TRANSPORT_RDMA:
1030                 break;
1031         default:
1032                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1033         }
1034 }
1035
1036 /*
1037  * For text based NFSv2/v3 mounts, the mount protocol transport default
1038  * settings should depend upon the specified NFS transport.
1039  */
1040 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1041 {
1042         nfs_validate_transport_protocol(mnt);
1043
1044         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1045             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1046                         return;
1047         switch (mnt->nfs_server.protocol) {
1048         case XPRT_TRANSPORT_UDP:
1049                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1050                 break;
1051         case XPRT_TRANSPORT_TCP:
1052         case XPRT_TRANSPORT_RDMA:
1053                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1054         }
1055 }
1056
1057 /*
1058  * Parse the value of the 'sec=' option.
1059  */
1060 static int nfs_parse_security_flavors(char *value,
1061                                       struct nfs_parsed_mount_data *mnt)
1062 {
1063         substring_t args[MAX_OPT_ARGS];
1064
1065         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1066
1067         switch (match_token(value, nfs_secflavor_tokens, args)) {
1068         case Opt_sec_none:
1069                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1070                 break;
1071         case Opt_sec_sys:
1072                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1073                 break;
1074         case Opt_sec_krb5:
1075                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1076                 break;
1077         case Opt_sec_krb5i:
1078                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1079                 break;
1080         case Opt_sec_krb5p:
1081                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1082                 break;
1083         case Opt_sec_lkey:
1084                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1085                 break;
1086         case Opt_sec_lkeyi:
1087                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1088                 break;
1089         case Opt_sec_lkeyp:
1090                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1091                 break;
1092         case Opt_sec_spkm:
1093                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1094                 break;
1095         case Opt_sec_spkmi:
1096                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1097                 break;
1098         case Opt_sec_spkmp:
1099                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1100                 break;
1101         default:
1102                 return 0;
1103         }
1104
1105         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1106         mnt->auth_flavor_len = 1;
1107         return 1;
1108 }
1109
1110 static int nfs_parse_version_string(char *string,
1111                 struct nfs_parsed_mount_data *mnt,
1112                 substring_t *args)
1113 {
1114         mnt->flags &= ~NFS_MOUNT_VER3;
1115         switch (match_token(string, nfs_vers_tokens, args)) {
1116         case Opt_vers_2:
1117                 mnt->version = 2;
1118                 break;
1119         case Opt_vers_3:
1120                 mnt->flags |= NFS_MOUNT_VER3;
1121                 mnt->version = 3;
1122                 break;
1123         case Opt_vers_4:
1124                 /* Backward compatibility option. In future,
1125                  * the mount program should always supply
1126                  * a NFSv4 minor version number.
1127                  */
1128                 mnt->version = 4;
1129                 break;
1130         case Opt_vers_4_0:
1131                 mnt->version = 4;
1132                 mnt->minorversion = 0;
1133                 break;
1134         case Opt_vers_4_1:
1135                 mnt->version = 4;
1136                 mnt->minorversion = 1;
1137                 break;
1138         default:
1139                 return 0;
1140         }
1141         return 1;
1142 }
1143
1144 static int nfs_get_option_str(substring_t args[], char **option)
1145 {
1146         kfree(*option);
1147         *option = match_strdup(args);
1148         return !option;
1149 }
1150
1151 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1152 {
1153         int rc;
1154         char *string;
1155
1156         string = match_strdup(args);
1157         if (string == NULL)
1158                 return -ENOMEM;
1159         rc = strict_strtoul(string, 10, option);
1160         kfree(string);
1161
1162         return rc;
1163 }
1164
1165 /*
1166  * Error-check and convert a string of mount options from user space into
1167  * a data structure.  The whole mount string is processed; bad options are
1168  * skipped as they are encountered.  If there were no errors, return 1;
1169  * otherwise return 0 (zero).
1170  */
1171 static int nfs_parse_mount_options(char *raw,
1172                                    struct nfs_parsed_mount_data *mnt)
1173 {
1174         char *p, *string, *secdata;
1175         int rc, sloppy = 0, invalid_option = 0;
1176         unsigned short protofamily = AF_UNSPEC;
1177         unsigned short mountfamily = AF_UNSPEC;
1178
1179         if (!raw) {
1180                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1181                 return 1;
1182         }
1183         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1184
1185         secdata = alloc_secdata();
1186         if (!secdata)
1187                 goto out_nomem;
1188
1189         rc = security_sb_copy_data(raw, secdata);
1190         if (rc)
1191                 goto out_security_failure;
1192
1193         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1194         if (rc)
1195                 goto out_security_failure;
1196
1197         free_secdata(secdata);
1198
1199         while ((p = strsep(&raw, ",")) != NULL) {
1200                 substring_t args[MAX_OPT_ARGS];
1201                 unsigned long option;
1202                 int token;
1203
1204                 if (!*p)
1205                         continue;
1206
1207                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1208
1209                 token = match_token(p, nfs_mount_option_tokens, args);
1210                 switch (token) {
1211
1212                 /*
1213                  * boolean options:  foo/nofoo
1214                  */
1215                 case Opt_soft:
1216                         mnt->flags |= NFS_MOUNT_SOFT;
1217                         break;
1218                 case Opt_hard:
1219                         mnt->flags &= ~NFS_MOUNT_SOFT;
1220                         break;
1221                 case Opt_posix:
1222                         mnt->flags |= NFS_MOUNT_POSIX;
1223                         break;
1224                 case Opt_noposix:
1225                         mnt->flags &= ~NFS_MOUNT_POSIX;
1226                         break;
1227                 case Opt_cto:
1228                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1229                         break;
1230                 case Opt_nocto:
1231                         mnt->flags |= NFS_MOUNT_NOCTO;
1232                         break;
1233                 case Opt_ac:
1234                         mnt->flags &= ~NFS_MOUNT_NOAC;
1235                         break;
1236                 case Opt_noac:
1237                         mnt->flags |= NFS_MOUNT_NOAC;
1238                         break;
1239                 case Opt_lock:
1240                         mnt->flags &= ~NFS_MOUNT_NONLM;
1241                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1242                                         NFS_MOUNT_LOCAL_FCNTL);
1243                         break;
1244                 case Opt_nolock:
1245                         mnt->flags |= NFS_MOUNT_NONLM;
1246                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1247                                        NFS_MOUNT_LOCAL_FCNTL);
1248                         break;
1249                 case Opt_udp:
1250                         mnt->flags &= ~NFS_MOUNT_TCP;
1251                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1252                         break;
1253                 case Opt_tcp:
1254                         mnt->flags |= NFS_MOUNT_TCP;
1255                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1256                         break;
1257                 case Opt_rdma:
1258                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1259                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1260                         xprt_load_transport(p);
1261                         break;
1262                 case Opt_acl:
1263                         mnt->flags &= ~NFS_MOUNT_NOACL;
1264                         break;
1265                 case Opt_noacl:
1266                         mnt->flags |= NFS_MOUNT_NOACL;
1267                         break;
1268                 case Opt_rdirplus:
1269                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1270                         break;
1271                 case Opt_nordirplus:
1272                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1273                         break;
1274                 case Opt_sharecache:
1275                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1276                         break;
1277                 case Opt_nosharecache:
1278                         mnt->flags |= NFS_MOUNT_UNSHARED;
1279                         break;
1280                 case Opt_resvport:
1281                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1282                         break;
1283                 case Opt_noresvport:
1284                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1285                         break;
1286                 case Opt_fscache:
1287                         mnt->options |= NFS_OPTION_FSCACHE;
1288                         kfree(mnt->fscache_uniq);
1289                         mnt->fscache_uniq = NULL;
1290                         break;
1291                 case Opt_nofscache:
1292                         mnt->options &= ~NFS_OPTION_FSCACHE;
1293                         kfree(mnt->fscache_uniq);
1294                         mnt->fscache_uniq = NULL;
1295                         break;
1296
1297                 /*
1298                  * options that take numeric values
1299                  */
1300                 case Opt_port:
1301                         if (nfs_get_option_ul(args, &option) ||
1302                             option > USHRT_MAX)
1303                                 goto out_invalid_value;
1304                         mnt->nfs_server.port = option;
1305                         break;
1306                 case Opt_rsize:
1307                         if (nfs_get_option_ul(args, &option))
1308                                 goto out_invalid_value;
1309                         mnt->rsize = option;
1310                         break;
1311                 case Opt_wsize:
1312                         if (nfs_get_option_ul(args, &option))
1313                                 goto out_invalid_value;
1314                         mnt->wsize = option;
1315                         break;
1316                 case Opt_bsize:
1317                         if (nfs_get_option_ul(args, &option))
1318                                 goto out_invalid_value;
1319                         mnt->bsize = option;
1320                         break;
1321                 case Opt_timeo:
1322                         if (nfs_get_option_ul(args, &option) || option == 0)
1323                                 goto out_invalid_value;
1324                         mnt->timeo = option;
1325                         break;
1326                 case Opt_retrans:
1327                         if (nfs_get_option_ul(args, &option) || option == 0)
1328                                 goto out_invalid_value;
1329                         mnt->retrans = option;
1330                         break;
1331                 case Opt_acregmin:
1332                         if (nfs_get_option_ul(args, &option))
1333                                 goto out_invalid_value;
1334                         mnt->acregmin = option;
1335                         break;
1336                 case Opt_acregmax:
1337                         if (nfs_get_option_ul(args, &option))
1338                                 goto out_invalid_value;
1339                         mnt->acregmax = option;
1340                         break;
1341                 case Opt_acdirmin:
1342                         if (nfs_get_option_ul(args, &option))
1343                                 goto out_invalid_value;
1344                         mnt->acdirmin = option;
1345                         break;
1346                 case Opt_acdirmax:
1347                         if (nfs_get_option_ul(args, &option))
1348                                 goto out_invalid_value;
1349                         mnt->acdirmax = option;
1350                         break;
1351                 case Opt_actimeo:
1352                         if (nfs_get_option_ul(args, &option))
1353                                 goto out_invalid_value;
1354                         mnt->acregmin = mnt->acregmax =
1355                         mnt->acdirmin = mnt->acdirmax = option;
1356                         break;
1357                 case Opt_namelen:
1358                         if (nfs_get_option_ul(args, &option))
1359                                 goto out_invalid_value;
1360                         mnt->namlen = option;
1361                         break;
1362                 case Opt_mountport:
1363                         if (nfs_get_option_ul(args, &option) ||
1364                             option > USHRT_MAX)
1365                                 goto out_invalid_value;
1366                         mnt->mount_server.port = option;
1367                         break;
1368                 case Opt_mountvers:
1369                         if (nfs_get_option_ul(args, &option) ||
1370                             option < NFS_MNT_VERSION ||
1371                             option > NFS_MNT3_VERSION)
1372                                 goto out_invalid_value;
1373                         mnt->mount_server.version = option;
1374                         break;
1375                 case Opt_minorversion:
1376                         if (nfs_get_option_ul(args, &option))
1377                                 goto out_invalid_value;
1378                         if (option > NFS4_MAX_MINOR_VERSION)
1379                                 goto out_invalid_value;
1380                         mnt->minorversion = option;
1381                         break;
1382
1383                 /*
1384                  * options that take text values
1385                  */
1386                 case Opt_nfsvers:
1387                         string = match_strdup(args);
1388                         if (string == NULL)
1389                                 goto out_nomem;
1390                         rc = nfs_parse_version_string(string, mnt, args);
1391                         kfree(string);
1392                         if (!rc)
1393                                 goto out_invalid_value;
1394                         break;
1395                 case Opt_sec:
1396                         string = match_strdup(args);
1397                         if (string == NULL)
1398                                 goto out_nomem;
1399                         rc = nfs_parse_security_flavors(string, mnt);
1400                         kfree(string);
1401                         if (!rc) {
1402                                 dfprintk(MOUNT, "NFS:   unrecognized "
1403                                                 "security flavor\n");
1404                                 return 0;
1405                         }
1406                         break;
1407                 case Opt_proto:
1408                         string = match_strdup(args);
1409                         if (string == NULL)
1410                                 goto out_nomem;
1411                         token = match_token(string,
1412                                             nfs_xprt_protocol_tokens, args);
1413
1414                         protofamily = AF_INET;
1415                         switch (token) {
1416                         case Opt_xprt_udp6:
1417                                 protofamily = AF_INET6;
1418                         case Opt_xprt_udp:
1419                                 mnt->flags &= ~NFS_MOUNT_TCP;
1420                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1421                                 break;
1422                         case Opt_xprt_tcp6:
1423                                 protofamily = AF_INET6;
1424                         case Opt_xprt_tcp:
1425                                 mnt->flags |= NFS_MOUNT_TCP;
1426                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1427                                 break;
1428                         case Opt_xprt_rdma:
1429                                 /* vector side protocols to TCP */
1430                                 mnt->flags |= NFS_MOUNT_TCP;
1431                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1432                                 xprt_load_transport(string);
1433                                 break;
1434                         default:
1435                                 dfprintk(MOUNT, "NFS:   unrecognized "
1436                                                 "transport protocol\n");
1437                                 kfree(string);
1438                                 return 0;
1439                         }
1440                         kfree(string);
1441                         break;
1442                 case Opt_mountproto:
1443                         string = match_strdup(args);
1444                         if (string == NULL)
1445                                 goto out_nomem;
1446                         token = match_token(string,
1447                                             nfs_xprt_protocol_tokens, args);
1448                         kfree(string);
1449
1450                         mountfamily = AF_INET;
1451                         switch (token) {
1452                         case Opt_xprt_udp6:
1453                                 mountfamily = AF_INET6;
1454                         case Opt_xprt_udp:
1455                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1456                                 break;
1457                         case Opt_xprt_tcp6:
1458                                 mountfamily = AF_INET6;
1459                         case Opt_xprt_tcp:
1460                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1461                                 break;
1462                         case Opt_xprt_rdma: /* not used for side protocols */
1463                         default:
1464                                 dfprintk(MOUNT, "NFS:   unrecognized "
1465                                                 "transport protocol\n");
1466                                 return 0;
1467                         }
1468                         break;
1469                 case Opt_addr:
1470                         string = match_strdup(args);
1471                         if (string == NULL)
1472                                 goto out_nomem;
1473                         mnt->nfs_server.addrlen =
1474                                 rpc_pton(mnt->net, string, strlen(string),
1475                                         (struct sockaddr *)
1476                                         &mnt->nfs_server.address,
1477                                         sizeof(mnt->nfs_server.address));
1478                         kfree(string);
1479                         if (mnt->nfs_server.addrlen == 0)
1480                                 goto out_invalid_address;
1481                         break;
1482                 case Opt_clientaddr:
1483                         if (nfs_get_option_str(args, &mnt->client_address))
1484                                 goto out_nomem;
1485                         break;
1486                 case Opt_mounthost:
1487                         if (nfs_get_option_str(args,
1488                                                &mnt->mount_server.hostname))
1489                                 goto out_nomem;
1490                         break;
1491                 case Opt_mountaddr:
1492                         string = match_strdup(args);
1493                         if (string == NULL)
1494                                 goto out_nomem;
1495                         mnt->mount_server.addrlen =
1496                                 rpc_pton(mnt->net, string, strlen(string),
1497                                         (struct sockaddr *)
1498                                         &mnt->mount_server.address,
1499                                         sizeof(mnt->mount_server.address));
1500                         kfree(string);
1501                         if (mnt->mount_server.addrlen == 0)
1502                                 goto out_invalid_address;
1503                         break;
1504                 case Opt_lookupcache:
1505                         string = match_strdup(args);
1506                         if (string == NULL)
1507                                 goto out_nomem;
1508                         token = match_token(string,
1509                                         nfs_lookupcache_tokens, args);
1510                         kfree(string);
1511                         switch (token) {
1512                                 case Opt_lookupcache_all:
1513                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1514                                         break;
1515                                 case Opt_lookupcache_positive:
1516                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1517                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1518                                         break;
1519                                 case Opt_lookupcache_none:
1520                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1521                                         break;
1522                                 default:
1523                                         dfprintk(MOUNT, "NFS:   invalid "
1524                                                         "lookupcache argument\n");
1525                                         return 0;
1526                         };
1527                         break;
1528                 case Opt_fscache_uniq:
1529                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1530                                 goto out_nomem;
1531                         mnt->options |= NFS_OPTION_FSCACHE;
1532                         break;
1533                 case Opt_local_lock:
1534                         string = match_strdup(args);
1535                         if (string == NULL)
1536                                 goto out_nomem;
1537                         token = match_token(string, nfs_local_lock_tokens,
1538                                         args);
1539                         kfree(string);
1540                         switch (token) {
1541                         case Opt_local_lock_all:
1542                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1543                                                NFS_MOUNT_LOCAL_FCNTL);
1544                                 break;
1545                         case Opt_local_lock_flock:
1546                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1547                                 break;
1548                         case Opt_local_lock_posix:
1549                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1550                                 break;
1551                         case Opt_local_lock_none:
1552                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1553                                                 NFS_MOUNT_LOCAL_FCNTL);
1554                                 break;
1555                         default:
1556                                 dfprintk(MOUNT, "NFS:   invalid "
1557                                                 "local_lock argument\n");
1558                                 return 0;
1559                         };
1560                         break;
1561
1562                 /*
1563                  * Special options
1564                  */
1565                 case Opt_sloppy:
1566                         sloppy = 1;
1567                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1568                         break;
1569                 case Opt_userspace:
1570                 case Opt_deprecated:
1571                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1572                                         "'%s'\n", p);
1573                         break;
1574
1575                 default:
1576                         invalid_option = 1;
1577                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1578                                         "'%s'\n", p);
1579                 }
1580         }
1581
1582         if (!sloppy && invalid_option)
1583                 return 0;
1584
1585         if (mnt->minorversion && mnt->version != 4)
1586                 goto out_minorversion_mismatch;
1587
1588         /*
1589          * verify that any proto=/mountproto= options match the address
1590          * familiies in the addr=/mountaddr= options.
1591          */
1592         if (protofamily != AF_UNSPEC &&
1593             protofamily != mnt->nfs_server.address.ss_family)
1594                 goto out_proto_mismatch;
1595
1596         if (mountfamily != AF_UNSPEC) {
1597                 if (mnt->mount_server.addrlen) {
1598                         if (mountfamily != mnt->mount_server.address.ss_family)
1599                                 goto out_mountproto_mismatch;
1600                 } else {
1601                         if (mountfamily != mnt->nfs_server.address.ss_family)
1602                                 goto out_mountproto_mismatch;
1603                 }
1604         }
1605
1606         return 1;
1607
1608 out_mountproto_mismatch:
1609         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1610                          "option\n");
1611         return 0;
1612 out_proto_mismatch:
1613         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1614         return 0;
1615 out_invalid_address:
1616         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1617         return 0;
1618 out_invalid_value:
1619         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1620         return 0;
1621 out_minorversion_mismatch:
1622         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1623                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1624         return 0;
1625 out_nomem:
1626         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1627         return 0;
1628 out_security_failure:
1629         free_secdata(secdata);
1630         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1631         return 0;
1632 }
1633
1634 /*
1635  * Match the requested auth flavors with the list returned by
1636  * the server.  Returns zero and sets the mount's authentication
1637  * flavor on success; returns -EACCES if server does not support
1638  * the requested flavor.
1639  */
1640 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1641                              struct nfs_mount_request *request)
1642 {
1643         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1644
1645         /*
1646          * Certain releases of Linux's mountd return an empty
1647          * flavor list.  To prevent behavioral regression with
1648          * these servers (ie. rejecting mounts that used to
1649          * succeed), revert to pre-2.6.32 behavior (no checking)
1650          * if the returned flavor list is empty.
1651          */
1652         if (server_authlist_len == 0)
1653                 return 0;
1654
1655         /*
1656          * We avoid sophisticated negotiating here, as there are
1657          * plenty of cases where we can get it wrong, providing
1658          * either too little or too much security.
1659          *
1660          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1661          * flavor listed first.  However, some servers list
1662          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1663          * preferred default, in args->auth_flavors[0] if user
1664          * didn't specify sec= mount option.
1665          */
1666         for (i = 0; i < args->auth_flavor_len; i++)
1667                 for (j = 0; j < server_authlist_len; j++)
1668                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1669                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1670                                         request->auth_flavs[j]);
1671                                 args->auth_flavors[0] = request->auth_flavs[j];
1672                                 return 0;
1673                         }
1674
1675         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1676         nfs_umount(request);
1677         return -EACCES;
1678 }
1679
1680 /*
1681  * Use the remote server's MOUNT service to request the NFS file handle
1682  * corresponding to the provided path.
1683  */
1684 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1685                          struct nfs_fh *root_fh)
1686 {
1687         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1688         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1689         struct nfs_mount_request request = {
1690                 .sap            = (struct sockaddr *)
1691                                                 &args->mount_server.address,
1692                 .dirpath        = args->nfs_server.export_path,
1693                 .protocol       = args->mount_server.protocol,
1694                 .fh             = root_fh,
1695                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1696                 .auth_flav_len  = &server_authlist_len,
1697                 .auth_flavs     = server_authlist,
1698                 .net            = args->net,
1699         };
1700         int status;
1701
1702         if (args->mount_server.version == 0) {
1703                 switch (args->version) {
1704                         default:
1705                                 args->mount_server.version = NFS_MNT3_VERSION;
1706                                 break;
1707                         case 2:
1708                                 args->mount_server.version = NFS_MNT_VERSION;
1709                 }
1710         }
1711         request.version = args->mount_server.version;
1712
1713         if (args->mount_server.hostname)
1714                 request.hostname = args->mount_server.hostname;
1715         else
1716                 request.hostname = args->nfs_server.hostname;
1717
1718         /*
1719          * Construct the mount server's address.
1720          */
1721         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1722                 memcpy(request.sap, &args->nfs_server.address,
1723                        args->nfs_server.addrlen);
1724                 args->mount_server.addrlen = args->nfs_server.addrlen;
1725         }
1726         request.salen = args->mount_server.addrlen;
1727         nfs_set_port(request.sap, &args->mount_server.port, 0);
1728
1729         /*
1730          * Now ask the mount server to map our export path
1731          * to a file handle.
1732          */
1733         status = nfs_mount(&request);
1734         if (status != 0) {
1735                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1736                                 request.hostname, status);
1737                 return status;
1738         }
1739
1740         /*
1741          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1742          */
1743         if (args->mount_server.version != NFS_MNT3_VERSION)
1744                 return 0;
1745         return nfs_walk_authlist(args, &request);
1746 }
1747
1748 /*
1749  * Split "dev_name" into "hostname:export_path".
1750  *
1751  * The leftmost colon demarks the split between the server's hostname
1752  * and the export path.  If the hostname starts with a left square
1753  * bracket, then it may contain colons.
1754  *
1755  * Note: caller frees hostname and export path, even on error.
1756  */
1757 static int nfs_parse_devname(const char *dev_name,
1758                              char **hostname, size_t maxnamlen,
1759                              char **export_path, size_t maxpathlen)
1760 {
1761         size_t len;
1762         char *end;
1763
1764         /* Is the host name protected with square brakcets? */
1765         if (*dev_name == '[') {
1766                 end = strchr(++dev_name, ']');
1767                 if (end == NULL || end[1] != ':')
1768                         goto out_bad_devname;
1769
1770                 len = end - dev_name;
1771                 end++;
1772         } else {
1773                 char *comma;
1774
1775                 end = strchr(dev_name, ':');
1776                 if (end == NULL)
1777                         goto out_bad_devname;
1778                 len = end - dev_name;
1779
1780                 /* kill possible hostname list: not supported */
1781                 comma = strchr(dev_name, ',');
1782                 if (comma != NULL && comma < end)
1783                         *comma = 0;
1784         }
1785
1786         if (len > maxnamlen)
1787                 goto out_hostname;
1788
1789         /* N.B. caller will free nfs_server.hostname in all cases */
1790         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1791         if (*hostname == NULL)
1792                 goto out_nomem;
1793         len = strlen(++end);
1794         if (len > maxpathlen)
1795                 goto out_path;
1796         *export_path = kstrndup(end, len, GFP_KERNEL);
1797         if (!*export_path)
1798                 goto out_nomem;
1799
1800         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1801         return 0;
1802
1803 out_bad_devname:
1804         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1805         return -EINVAL;
1806
1807 out_nomem:
1808         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1809         return -ENOMEM;
1810
1811 out_hostname:
1812         dfprintk(MOUNT, "NFS: server hostname too long\n");
1813         return -ENAMETOOLONG;
1814
1815 out_path:
1816         dfprintk(MOUNT, "NFS: export pathname too long\n");
1817         return -ENAMETOOLONG;
1818 }
1819
1820 /*
1821  * Validate the NFS2/NFS3 mount data
1822  * - fills in the mount root filehandle
1823  *
1824  * For option strings, user space handles the following behaviors:
1825  *
1826  * + DNS: mapping server host name to IP address ("addr=" option)
1827  *
1828  * + failure mode: how to behave if a mount request can't be handled
1829  *   immediately ("fg/bg" option)
1830  *
1831  * + retry: how often to retry a mount request ("retry=" option)
1832  *
1833  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1834  *   mountproto=tcp after mountproto=udp, and so on
1835  */
1836 static int nfs_validate_mount_data(void *options,
1837                                    struct nfs_parsed_mount_data *args,
1838                                    struct nfs_fh *mntfh,
1839                                    const char *dev_name)
1840 {
1841         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1842         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1843
1844         if (data == NULL)
1845                 goto out_no_data;
1846
1847         switch (data->version) {
1848         case 1:
1849                 data->namlen = 0;
1850         case 2:
1851                 data->bsize = 0;
1852         case 3:
1853                 if (data->flags & NFS_MOUNT_VER3)
1854                         goto out_no_v3;
1855                 data->root.size = NFS2_FHSIZE;
1856                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1857         case 4:
1858                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1859                         goto out_no_sec;
1860         case 5:
1861                 memset(data->context, 0, sizeof(data->context));
1862         case 6:
1863                 if (data->flags & NFS_MOUNT_VER3) {
1864                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1865                                 goto out_invalid_fh;
1866                         mntfh->size = data->root.size;
1867                         args->version = 3;
1868                 } else {
1869                         mntfh->size = NFS2_FHSIZE;
1870                         args->version = 2;
1871                 }
1872
1873
1874                 memcpy(mntfh->data, data->root.data, mntfh->size);
1875                 if (mntfh->size < sizeof(mntfh->data))
1876                         memset(mntfh->data + mntfh->size, 0,
1877                                sizeof(mntfh->data) - mntfh->size);
1878
1879                 /*
1880                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1881                  * can deal with.
1882                  */
1883                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1884                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1885                 args->rsize             = data->rsize;
1886                 args->wsize             = data->wsize;
1887                 args->timeo             = data->timeo;
1888                 args->retrans           = data->retrans;
1889                 args->acregmin          = data->acregmin;
1890                 args->acregmax          = data->acregmax;
1891                 args->acdirmin          = data->acdirmin;
1892                 args->acdirmax          = data->acdirmax;
1893
1894                 memcpy(sap, &data->addr, sizeof(data->addr));
1895                 args->nfs_server.addrlen = sizeof(data->addr);
1896                 if (!nfs_verify_server_address(sap))
1897                         goto out_no_address;
1898
1899                 if (!(data->flags & NFS_MOUNT_TCP))
1900                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1901                 /* N.B. caller will free nfs_server.hostname in all cases */
1902                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1903                 args->namlen            = data->namlen;
1904                 args->bsize             = data->bsize;
1905
1906                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1907                         args->auth_flavors[0] = data->pseudoflavor;
1908                 if (!args->nfs_server.hostname)
1909                         goto out_nomem;
1910
1911                 if (!(data->flags & NFS_MOUNT_NONLM))
1912                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1913                                          NFS_MOUNT_LOCAL_FCNTL);
1914                 else
1915                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1916                                         NFS_MOUNT_LOCAL_FCNTL);
1917                 /*
1918                  * The legacy version 6 binary mount data from userspace has a
1919                  * field used only to transport selinux information into the
1920                  * the kernel.  To continue to support that functionality we
1921                  * have a touch of selinux knowledge here in the NFS code. The
1922                  * userspace code converted context=blah to just blah so we are
1923                  * converting back to the full string selinux understands.
1924                  */
1925                 if (data->context[0]){
1926 #ifdef CONFIG_SECURITY_SELINUX
1927                         int rc;
1928                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1929                         if (!opts_str)
1930                                 return -ENOMEM;
1931                         strcpy(opts_str, "context=");
1932                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1933                         strcat(opts_str, &data->context[0]);
1934                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1935                         kfree(opts_str);
1936                         if (rc)
1937                                 return rc;
1938 #else
1939                         return -EINVAL;
1940 #endif
1941                 }
1942
1943                 break;
1944         default: {
1945                 int status;
1946
1947                 if (nfs_parse_mount_options((char *)options, args) == 0)
1948                         return -EINVAL;
1949
1950                 if (!nfs_verify_server_address(sap))
1951                         goto out_no_address;
1952
1953                 if (args->version == 4)
1954 #ifdef CONFIG_NFS_V4
1955                         return nfs4_validate_text_mount_data(options,
1956                                                              args, dev_name);
1957 #else
1958                         goto out_v4_not_compiled;
1959 #endif
1960
1961                 nfs_set_port(sap, &args->nfs_server.port, 0);
1962
1963                 nfs_set_mount_transport_protocol(args);
1964
1965                 status = nfs_parse_devname(dev_name,
1966                                            &args->nfs_server.hostname,
1967                                            PAGE_SIZE,
1968                                            &args->nfs_server.export_path,
1969                                            NFS_MAXPATHLEN);
1970                 if (!status)
1971                         status = nfs_try_mount(args, mntfh);
1972
1973                 kfree(args->nfs_server.export_path);
1974                 args->nfs_server.export_path = NULL;
1975
1976                 if (status)
1977                         return status;
1978
1979                 break;
1980                 }
1981         }
1982
1983 #ifndef CONFIG_NFS_V3
1984         if (args->version == 3)
1985                 goto out_v3_not_compiled;
1986 #endif /* !CONFIG_NFS_V3 */
1987
1988         return 0;
1989
1990 out_no_data:
1991         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1992         return -EINVAL;
1993
1994 out_no_v3:
1995         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1996                  data->version);
1997         return -EINVAL;
1998
1999 out_no_sec:
2000         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2001         return -EINVAL;
2002
2003 #ifndef CONFIG_NFS_V3
2004 out_v3_not_compiled:
2005         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
2006         return -EPROTONOSUPPORT;
2007 #endif /* !CONFIG_NFS_V3 */
2008
2009 #ifndef CONFIG_NFS_V4
2010 out_v4_not_compiled:
2011         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2012         return -EPROTONOSUPPORT;
2013 #endif /* !CONFIG_NFS_V4 */
2014
2015 out_nomem:
2016         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2017         return -ENOMEM;
2018
2019 out_no_address:
2020         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2021         return -EINVAL;
2022
2023 out_invalid_fh:
2024         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2025         return -EINVAL;
2026 }
2027
2028 static int
2029 nfs_compare_remount_data(struct nfs_server *nfss,
2030                          struct nfs_parsed_mount_data *data)
2031 {
2032         if (data->flags != nfss->flags ||
2033             data->rsize != nfss->rsize ||
2034             data->wsize != nfss->wsize ||
2035             data->retrans != nfss->client->cl_timeout->to_retries ||
2036             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2037             data->acregmin != nfss->acregmin / HZ ||
2038             data->acregmax != nfss->acregmax / HZ ||
2039             data->acdirmin != nfss->acdirmin / HZ ||
2040             data->acdirmax != nfss->acdirmax / HZ ||
2041             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2042             data->nfs_server.port != nfss->port ||
2043             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2044             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2045                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2046                 return -EINVAL;
2047
2048         return 0;
2049 }
2050
2051 static int
2052 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2053 {
2054         int error;
2055         struct nfs_server *nfss = sb->s_fs_info;
2056         struct nfs_parsed_mount_data *data;
2057         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2058         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2059         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2060
2061         /*
2062          * Userspace mount programs that send binary options generally send
2063          * them populated with default values. We have no way to know which
2064          * ones were explicitly specified. Fall back to legacy behavior and
2065          * just return success.
2066          */
2067         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2068             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2069                                            options->version <= 6))))
2070                 return 0;
2071
2072         data = kzalloc(sizeof(*data), GFP_KERNEL);
2073         if (data == NULL)
2074                 return -ENOMEM;
2075
2076         /* fill out struct with values from existing mount */
2077         data->flags = nfss->flags;
2078         data->rsize = nfss->rsize;
2079         data->wsize = nfss->wsize;
2080         data->retrans = nfss->client->cl_timeout->to_retries;
2081         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2082         data->acregmin = nfss->acregmin / HZ;
2083         data->acregmax = nfss->acregmax / HZ;
2084         data->acdirmin = nfss->acdirmin / HZ;
2085         data->acdirmax = nfss->acdirmax / HZ;
2086         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2087         data->nfs_server.port = nfss->port;
2088         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2089         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2090                 data->nfs_server.addrlen);
2091
2092         /* overwrite those values with any that were specified */
2093         error = nfs_parse_mount_options((char *)options, data);
2094         if (error < 0)
2095                 goto out;
2096
2097         /*
2098          * noac is a special case. It implies -o sync, but that's not
2099          * necessarily reflected in the mtab options. do_remount_sb
2100          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2101          * remount options, so we have to explicitly reset it.
2102          */
2103         if (data->flags & NFS_MOUNT_NOAC)
2104                 *flags |= MS_SYNCHRONOUS;
2105
2106         /* compare new mount options with old ones */
2107         error = nfs_compare_remount_data(nfss, data);
2108 out:
2109         kfree(data);
2110         return error;
2111 }
2112
2113 /*
2114  * Initialise the common bits of the superblock
2115  */
2116 static inline void nfs_initialise_sb(struct super_block *sb)
2117 {
2118         struct nfs_server *server = NFS_SB(sb);
2119
2120         sb->s_magic = NFS_SUPER_MAGIC;
2121
2122         /* We probably want something more informative here */
2123         snprintf(sb->s_id, sizeof(sb->s_id),
2124                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2125
2126         if (sb->s_blocksize == 0)
2127                 sb->s_blocksize = nfs_block_bits(server->wsize,
2128                                                  &sb->s_blocksize_bits);
2129
2130         sb->s_bdi = &server->backing_dev_info;
2131
2132         nfs_super_set_maxbytes(sb, server->maxfilesize);
2133 }
2134
2135 /*
2136  * Finish setting up an NFS2/3 superblock
2137  */
2138 static void nfs_fill_super(struct super_block *sb,
2139                            struct nfs_mount_info *mount_info)
2140 {
2141         struct nfs_parsed_mount_data *data = mount_info->parsed;
2142         struct nfs_server *server = NFS_SB(sb);
2143
2144         sb->s_blocksize_bits = 0;
2145         sb->s_blocksize = 0;
2146         if (data->bsize)
2147                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2148
2149         if (server->nfs_client->rpc_ops->version == 3) {
2150                 /* The VFS shouldn't apply the umask to mode bits. We will do
2151                  * so ourselves when necessary.
2152                  */
2153                 sb->s_flags |= MS_POSIXACL;
2154                 sb->s_time_gran = 1;
2155         }
2156
2157         sb->s_op = &nfs_sops;
2158         nfs_initialise_sb(sb);
2159 }
2160
2161 /*
2162  * Finish setting up a cloned NFS2/3 superblock
2163  */
2164 static void nfs_clone_super(struct super_block *sb,
2165                             struct nfs_mount_info *mount_info)
2166 {
2167         const struct super_block *old_sb = mount_info->cloned->sb;
2168         struct nfs_server *server = NFS_SB(sb);
2169
2170         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2171         sb->s_blocksize = old_sb->s_blocksize;
2172         sb->s_maxbytes = old_sb->s_maxbytes;
2173
2174         if (server->nfs_client->rpc_ops->version == 3) {
2175                 /* The VFS shouldn't apply the umask to mode bits. We will do
2176                  * so ourselves when necessary.
2177                  */
2178                 sb->s_flags |= MS_POSIXACL;
2179                 sb->s_time_gran = 1;
2180         }
2181
2182         sb->s_op = old_sb->s_op;
2183         nfs_initialise_sb(sb);
2184 }
2185
2186 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2187 {
2188         const struct nfs_server *a = s->s_fs_info;
2189         const struct rpc_clnt *clnt_a = a->client;
2190         const struct rpc_clnt *clnt_b = b->client;
2191
2192         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2193                 goto Ebusy;
2194         if (a->nfs_client != b->nfs_client)
2195                 goto Ebusy;
2196         if (a->flags != b->flags)
2197                 goto Ebusy;
2198         if (a->wsize != b->wsize)
2199                 goto Ebusy;
2200         if (a->rsize != b->rsize)
2201                 goto Ebusy;
2202         if (a->acregmin != b->acregmin)
2203                 goto Ebusy;
2204         if (a->acregmax != b->acregmax)
2205                 goto Ebusy;
2206         if (a->acdirmin != b->acdirmin)
2207                 goto Ebusy;
2208         if (a->acdirmax != b->acdirmax)
2209                 goto Ebusy;
2210         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2211                 goto Ebusy;
2212         return 1;
2213 Ebusy:
2214         return 0;
2215 }
2216
2217 struct nfs_sb_mountdata {
2218         struct nfs_server *server;
2219         int mntflags;
2220 };
2221
2222 static int nfs_set_super(struct super_block *s, void *data)
2223 {
2224         struct nfs_sb_mountdata *sb_mntdata = data;
2225         struct nfs_server *server = sb_mntdata->server;
2226         int ret;
2227
2228         s->s_flags = sb_mntdata->mntflags;
2229         s->s_fs_info = server;
2230         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2231         ret = set_anon_super(s, server);
2232         if (ret == 0)
2233                 server->s_dev = s->s_dev;
2234         return ret;
2235 }
2236
2237 static int nfs_compare_super_address(struct nfs_server *server1,
2238                                      struct nfs_server *server2)
2239 {
2240         struct sockaddr *sap1, *sap2;
2241
2242         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2243         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2244
2245         if (sap1->sa_family != sap2->sa_family)
2246                 return 0;
2247
2248         switch (sap1->sa_family) {
2249         case AF_INET: {
2250                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2251                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2252                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2253                         return 0;
2254                 if (sin1->sin_port != sin2->sin_port)
2255                         return 0;
2256                 break;
2257         }
2258         case AF_INET6: {
2259                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2260                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2261                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2262                         return 0;
2263                 if (sin1->sin6_port != sin2->sin6_port)
2264                         return 0;
2265                 break;
2266         }
2267         default:
2268                 return 0;
2269         }
2270
2271         return 1;
2272 }
2273
2274 static int nfs_compare_super(struct super_block *sb, void *data)
2275 {
2276         struct nfs_sb_mountdata *sb_mntdata = data;
2277         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2278         int mntflags = sb_mntdata->mntflags;
2279
2280         if (!nfs_compare_super_address(old, server))
2281                 return 0;
2282         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2283         if (old->flags & NFS_MOUNT_UNSHARED)
2284                 return 0;
2285         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2286                 return 0;
2287         return nfs_compare_mount_options(sb, server, mntflags);
2288 }
2289
2290 static void nfs_get_cache_cookie(struct super_block *sb,
2291                                  struct nfs_parsed_mount_data *parsed,
2292                                  struct nfs_clone_mount *cloned)
2293 {
2294         char *uniq = NULL;
2295         int ulen = 0;
2296
2297         if (parsed && parsed->fscache_uniq) {
2298                 uniq = parsed->fscache_uniq;
2299                 ulen = strlen(parsed->fscache_uniq);
2300         } else if (cloned) {
2301                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2302                 if (mnt_s->fscache_key) {
2303                         uniq = mnt_s->fscache_key->key.uniquifier;
2304                         ulen = mnt_s->fscache_key->key.uniq_len;
2305                 };
2306         }
2307
2308         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2309 }
2310
2311 static int nfs_bdi_register(struct nfs_server *server)
2312 {
2313         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2314 }
2315
2316 static int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2317                                struct nfs_mount_info *mount_info)
2318 {
2319         return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2320 }
2321
2322 static int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2323                                  struct nfs_mount_info *mount_info)
2324 {
2325         /* clone any lsm security options from the parent to the new sb */
2326         security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2327         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2328                 return -ESTALE;
2329         return 0;
2330 }
2331
2332 static struct dentry *nfs_fs_mount_common(struct file_system_type *fs_type,
2333                                           struct nfs_server *server,
2334                                           int flags, const char *dev_name,
2335                                           struct nfs_fh *mntfh,
2336                                           struct nfs_mount_info *mount_info)
2337 {
2338         struct super_block *s;
2339         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2340         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2341         struct nfs_sb_mountdata sb_mntdata = {
2342                 .mntflags = flags,
2343                 .server = server,
2344         };
2345         int error;
2346
2347         if (server->flags & NFS_MOUNT_UNSHARED)
2348                 compare_super = NULL;
2349
2350         /* -o noac implies -o sync */
2351         if (server->flags & NFS_MOUNT_NOAC)
2352                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2353
2354         /* Get a superblock - note that we may end up sharing one that already exists */
2355         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2356         if (IS_ERR(s)) {
2357                 mntroot = ERR_CAST(s);
2358                 goto out_err_nosb;
2359         }
2360
2361         if (s->s_fs_info != server) {
2362                 nfs_free_server(server);
2363                 server = NULL;
2364         } else {
2365                 error = nfs_bdi_register(server);
2366                 if (error) {
2367                         mntroot = ERR_PTR(error);
2368                         goto error_splat_bdi;
2369                 }
2370         }
2371
2372         if (!s->s_root) {
2373                 /* initial superblock/root creation */
2374                 mount_info->fill_super(s, mount_info);
2375                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2376         }
2377
2378         mntroot = nfs_get_root(s, mntfh, dev_name);
2379         if (IS_ERR(mntroot))
2380                 goto error_splat_super;
2381
2382         error = mount_info->set_security(s, mntroot, mount_info);
2383         if (error)
2384                 goto error_splat_root;
2385
2386         s->s_flags |= MS_ACTIVE;
2387
2388 out:
2389         return mntroot;
2390
2391 out_err_nosb:
2392         nfs_free_server(server);
2393         goto out;
2394
2395 error_splat_root:
2396         dput(mntroot);
2397         mntroot = ERR_PTR(error);
2398 error_splat_super:
2399         if (server && !s->s_root)
2400                 bdi_unregister(&server->backing_dev_info);
2401 error_splat_bdi:
2402         deactivate_locked_super(s);
2403         goto out;
2404 }
2405
2406 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2407         int flags, const char *dev_name, void *raw_data)
2408 {
2409         struct nfs_server *server;
2410         struct nfs_parsed_mount_data *data = NULL;
2411         struct nfs_mount_info mount_info = {
2412                 .fill_super = nfs_fill_super,
2413                 .set_security = nfs_set_sb_security,
2414         };
2415         struct nfs_fh *mntfh;
2416         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2417         int error;
2418
2419         data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2420         mntfh = nfs_alloc_fhandle();
2421         if (data == NULL || mntfh == NULL)
2422                 goto out;
2423
2424         /* Validate the mount data */
2425         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2426         if (error < 0) {
2427                 mntroot = ERR_PTR(error);
2428                 goto out;
2429         }
2430         mount_info.parsed = data;
2431
2432 #ifdef CONFIG_NFS_V4
2433         if (data->version == 4) {
2434                 mntroot = nfs4_try_mount(flags, dev_name, data);
2435                 goto out;
2436         }
2437 #endif  /* CONFIG_NFS_V4 */
2438
2439         /* Get a volume representation */
2440         server = nfs_create_server(data, mntfh);
2441         if (IS_ERR(server)) {
2442                 mntroot = ERR_CAST(server);
2443                 goto out;
2444         }
2445
2446         mntroot = nfs_fs_mount_common(fs_type, server, flags, dev_name, mntfh, &mount_info);
2447 out:
2448         nfs_free_parsed_mount_data(data);
2449         nfs_free_fhandle(mntfh);
2450         return mntroot;
2451 }
2452
2453 /*
2454  * Ensure that we unregister the bdi before kill_anon_super
2455  * releases the device name
2456  */
2457 static void nfs_put_super(struct super_block *s)
2458 {
2459         struct nfs_server *server = NFS_SB(s);
2460
2461         bdi_unregister(&server->backing_dev_info);
2462 }
2463
2464 /*
2465  * Destroy an NFS2/3 superblock
2466  */
2467 static void nfs_kill_super(struct super_block *s)
2468 {
2469         struct nfs_server *server = NFS_SB(s);
2470
2471         kill_anon_super(s);
2472         nfs_fscache_release_super_cookie(s);
2473         nfs_free_server(server);
2474 }
2475
2476 /*
2477  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2478  */
2479 static struct dentry *
2480 nfs_xdev_mount_common(struct file_system_type *fs_type, int flags,
2481                 const char *dev_name, struct nfs_mount_info *mount_info)
2482 {
2483         struct nfs_clone_mount *data = mount_info->cloned;
2484         struct nfs_server *server;
2485         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2486         int error;
2487
2488         dprintk("--> nfs_xdev_mount_common()\n");
2489
2490         /* create a new volume representation */
2491         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2492         if (IS_ERR(server)) {
2493                 error = PTR_ERR(server);
2494                 goto out_err;
2495         }
2496
2497         mntroot = nfs_fs_mount_common(fs_type, server, flags, dev_name, data->fh, mount_info);
2498         dprintk("<-- nfs_xdev_mount_common() = 0\n");
2499 out:
2500         return mntroot;
2501
2502 out_err:
2503         dprintk("<-- nfs_xdev_mount_common() = %d [error]\n", error);
2504         goto out;
2505 }
2506
2507 /*
2508  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2509  */
2510 static struct dentry *
2511 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2512                 const char *dev_name, void *raw_data)
2513 {
2514         struct nfs_mount_info mount_info = {
2515                 .fill_super = nfs_clone_super,
2516                 .set_security = nfs_clone_sb_security,
2517                 .cloned   = raw_data,
2518         };
2519         return nfs_xdev_mount_common(&nfs_fs_type, flags, dev_name, &mount_info);
2520 }
2521
2522 #ifdef CONFIG_NFS_V4
2523
2524 /*
2525  * Finish setting up a cloned NFS4 superblock
2526  */
2527 static void nfs4_clone_super(struct super_block *sb,
2528                              struct nfs_mount_info *mount_info)
2529 {
2530         const struct super_block *old_sb = mount_info->cloned->sb;
2531         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2532         sb->s_blocksize = old_sb->s_blocksize;
2533         sb->s_maxbytes = old_sb->s_maxbytes;
2534         sb->s_time_gran = 1;
2535         sb->s_op = old_sb->s_op;
2536         /*
2537          * The VFS shouldn't apply the umask to mode bits. We will do
2538          * so ourselves when necessary.
2539          */
2540         sb->s_flags  |= MS_POSIXACL;
2541         sb->s_xattr  = old_sb->s_xattr;
2542         nfs_initialise_sb(sb);
2543 }
2544
2545 /*
2546  * Set up an NFS4 superblock
2547  */
2548 static void nfs4_fill_super(struct super_block *sb,
2549                             struct nfs_mount_info *mount_info)
2550 {
2551         sb->s_time_gran = 1;
2552         sb->s_op = &nfs4_sops;
2553         /*
2554          * The VFS shouldn't apply the umask to mode bits. We will do
2555          * so ourselves when necessary.
2556          */
2557         sb->s_flags  |= MS_POSIXACL;
2558         sb->s_xattr = nfs4_xattr_handlers;
2559         nfs_initialise_sb(sb);
2560 }
2561
2562 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2563 {
2564         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2565                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2566 }
2567
2568 static int nfs4_validate_text_mount_data(void *options,
2569                                          struct nfs_parsed_mount_data *args,
2570                                          const char *dev_name)
2571 {
2572         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2573
2574         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2575
2576         nfs_validate_transport_protocol(args);
2577
2578         nfs4_validate_mount_flags(args);
2579
2580         if (args->version != 4) {
2581                 dfprintk(MOUNT,
2582                          "NFS4: Illegal mount version\n");
2583                 return -EINVAL;
2584         }
2585
2586         if (args->auth_flavor_len > 1) {
2587                 dfprintk(MOUNT,
2588                          "NFS4: Too many RPC auth flavours specified\n");
2589                 return -EINVAL;
2590         }
2591
2592         return nfs_parse_devname(dev_name,
2593                                    &args->nfs_server.hostname,
2594                                    NFS4_MAXNAMLEN,
2595                                    &args->nfs_server.export_path,
2596                                    NFS4_MAXPATHLEN);
2597 }
2598
2599 /*
2600  * Validate NFSv4 mount options
2601  */
2602 static int nfs4_validate_mount_data(void *options,
2603                                     struct nfs_parsed_mount_data *args,
2604                                     const char *dev_name)
2605 {
2606         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2607         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2608         char *c;
2609
2610         if (data == NULL)
2611                 goto out_no_data;
2612
2613         switch (data->version) {
2614         case 1:
2615                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2616                         goto out_no_address;
2617                 if (data->host_addrlen == 0)
2618                         goto out_no_address;
2619                 args->nfs_server.addrlen = data->host_addrlen;
2620                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2621                         return -EFAULT;
2622                 if (!nfs_verify_server_address(sap))
2623                         goto out_no_address;
2624
2625                 if (data->auth_flavourlen) {
2626                         if (data->auth_flavourlen > 1)
2627                                 goto out_inval_auth;
2628                         if (copy_from_user(&args->auth_flavors[0],
2629                                            data->auth_flavours,
2630                                            sizeof(args->auth_flavors[0])))
2631                                 return -EFAULT;
2632                 }
2633
2634                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2635                 if (IS_ERR(c))
2636                         return PTR_ERR(c);
2637                 args->nfs_server.hostname = c;
2638
2639                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2640                 if (IS_ERR(c))
2641                         return PTR_ERR(c);
2642                 args->nfs_server.export_path = c;
2643                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2644
2645                 c = strndup_user(data->client_addr.data, 16);
2646                 if (IS_ERR(c))
2647                         return PTR_ERR(c);
2648                 args->client_address = c;
2649
2650                 /*
2651                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2652                  * can deal with.
2653                  */
2654
2655                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2656                 args->rsize     = data->rsize;
2657                 args->wsize     = data->wsize;
2658                 args->timeo     = data->timeo;
2659                 args->retrans   = data->retrans;
2660                 args->acregmin  = data->acregmin;
2661                 args->acregmax  = data->acregmax;
2662                 args->acdirmin  = data->acdirmin;
2663                 args->acdirmax  = data->acdirmax;
2664                 args->nfs_server.protocol = data->proto;
2665                 nfs_validate_transport_protocol(args);
2666
2667                 break;
2668         default:
2669                 if (nfs_parse_mount_options((char *)options, args) == 0)
2670                         return -EINVAL;
2671
2672                 if (!nfs_verify_server_address(sap))
2673                         return -EINVAL;
2674
2675                 return nfs4_validate_text_mount_data(options, args, dev_name);
2676         }
2677
2678         return 0;
2679
2680 out_no_data:
2681         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2682         return -EINVAL;
2683
2684 out_inval_auth:
2685         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2686                  data->auth_flavourlen);
2687         return -EINVAL;
2688
2689 out_no_address:
2690         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2691         return -EINVAL;
2692 }
2693
2694 /*
2695  * Get the superblock for the NFS4 root partition
2696  */
2697 static struct dentry *
2698 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2699                   const char *dev_name, void *raw_data)
2700 {
2701         struct nfs_mount_info mount_info = {
2702                 .fill_super = nfs4_fill_super,
2703                 .set_security = nfs_set_sb_security,
2704                 .parsed = raw_data,
2705         };
2706         struct nfs_server *server;
2707         struct nfs_fh *mntfh;
2708         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2709
2710         mntfh = nfs_alloc_fhandle();
2711         if (mount_info.parsed == NULL || mntfh == NULL)
2712                 goto out;
2713
2714         /* Get a volume representation */
2715         server = nfs4_create_server(mount_info.parsed, mntfh);
2716         if (IS_ERR(server)) {
2717                 mntroot = ERR_CAST(server);
2718                 goto out;
2719         }
2720
2721         mntroot = nfs_fs_mount_common(fs_type, server, flags,
2722                                       dev_name, mntfh, &mount_info);
2723
2724 out:
2725         nfs_free_fhandle(mntfh);
2726         return mntroot;
2727 }
2728
2729 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2730                 int flags, void *data, const char *hostname)
2731 {
2732         struct vfsmount *root_mnt;
2733         char *root_devname;
2734         size_t len;
2735
2736         len = strlen(hostname) + 5;
2737         root_devname = kmalloc(len, GFP_KERNEL);
2738         if (root_devname == NULL)
2739                 return ERR_PTR(-ENOMEM);
2740         /* Does hostname needs to be enclosed in brackets? */
2741         if (strchr(hostname, ':'))
2742                 snprintf(root_devname, len, "[%s]:/", hostname);
2743         else
2744                 snprintf(root_devname, len, "%s:/", hostname);
2745         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2746         kfree(root_devname);
2747         return root_mnt;
2748 }
2749
2750 struct nfs_referral_count {
2751         struct list_head list;
2752         const struct task_struct *task;
2753         unsigned int referral_count;
2754 };
2755
2756 static LIST_HEAD(nfs_referral_count_list);
2757 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2758
2759 static struct nfs_referral_count *nfs_find_referral_count(void)
2760 {
2761         struct nfs_referral_count *p;
2762
2763         list_for_each_entry(p, &nfs_referral_count_list, list) {
2764                 if (p->task == current)
2765                         return p;
2766         }
2767         return NULL;
2768 }
2769
2770 #define NFS_MAX_NESTED_REFERRALS 2
2771
2772 static int nfs_referral_loop_protect(void)
2773 {
2774         struct nfs_referral_count *p, *new;
2775         int ret = -ENOMEM;
2776
2777         new = kmalloc(sizeof(*new), GFP_KERNEL);
2778         if (!new)
2779                 goto out;
2780         new->task = current;
2781         new->referral_count = 1;
2782
2783         ret = 0;
2784         spin_lock(&nfs_referral_count_list_lock);
2785         p = nfs_find_referral_count();
2786         if (p != NULL) {
2787                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2788                         ret = -ELOOP;
2789                 else
2790                         p->referral_count++;
2791         } else {
2792                 list_add(&new->list, &nfs_referral_count_list);
2793                 new = NULL;
2794         }
2795         spin_unlock(&nfs_referral_count_list_lock);
2796         kfree(new);
2797 out:
2798         return ret;
2799 }
2800
2801 static void nfs_referral_loop_unprotect(void)
2802 {
2803         struct nfs_referral_count *p;
2804
2805         spin_lock(&nfs_referral_count_list_lock);
2806         p = nfs_find_referral_count();
2807         p->referral_count--;
2808         if (p->referral_count == 0)
2809                 list_del(&p->list);
2810         else
2811                 p = NULL;
2812         spin_unlock(&nfs_referral_count_list_lock);
2813         kfree(p);
2814 }
2815
2816 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2817                 const char *export_path)
2818 {
2819         struct dentry *dentry;
2820         int err;
2821
2822         if (IS_ERR(root_mnt))
2823                 return ERR_CAST(root_mnt);
2824
2825         err = nfs_referral_loop_protect();
2826         if (err) {
2827                 mntput(root_mnt);
2828                 return ERR_PTR(err);
2829         }
2830
2831         dentry = mount_subtree(root_mnt, export_path);
2832         nfs_referral_loop_unprotect();
2833
2834         return dentry;
2835 }
2836
2837 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2838                          struct nfs_parsed_mount_data *data)
2839 {
2840         char *export_path;
2841         struct vfsmount *root_mnt;
2842         struct dentry *res;
2843
2844         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2845
2846         export_path = data->nfs_server.export_path;
2847         data->nfs_server.export_path = "/";
2848         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2849                         data->nfs_server.hostname);
2850         data->nfs_server.export_path = export_path;
2851
2852         res = nfs_follow_remote_path(root_mnt, export_path);
2853
2854         dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2855                         IS_ERR(res) ? PTR_ERR(res) : 0,
2856                         IS_ERR(res) ? " [error]" : "");
2857         return res;
2858 }
2859
2860 /*
2861  * Get the superblock for an NFS4 mountpoint
2862  */
2863 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2864         int flags, const char *dev_name, void *raw_data)
2865 {
2866         struct nfs_parsed_mount_data *data;
2867         int error = -ENOMEM;
2868         struct dentry *res = ERR_PTR(-ENOMEM);
2869
2870         data = nfs_alloc_parsed_mount_data(4);
2871         if (data == NULL)
2872                 goto out;
2873
2874         /* Validate the mount data */
2875         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2876         if (error < 0) {
2877                 res = ERR_PTR(error);
2878                 goto out;
2879         }
2880
2881         res = nfs4_try_mount(flags, dev_name, data);
2882         if (IS_ERR(res))
2883                 error = PTR_ERR(res);
2884
2885 out:
2886         nfs_free_parsed_mount_data(data);
2887         dprintk("<-- nfs4_mount() = %d%s\n", error,
2888                         error != 0 ? " [error]" : "");
2889         return res;
2890 }
2891
2892 static void nfs4_kill_super(struct super_block *sb)
2893 {
2894         struct nfs_server *server = NFS_SB(sb);
2895
2896         dprintk("--> %s\n", __func__);
2897         nfs_super_return_all_delegations(sb);
2898         kill_anon_super(sb);
2899         nfs_fscache_release_super_cookie(sb);
2900         nfs_free_server(server);
2901         dprintk("<-- %s\n", __func__);
2902 }
2903
2904 /*
2905  * Clone an NFS4 server record on xdev traversal (FSID-change)
2906  */
2907 static struct dentry *
2908 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2909                  const char *dev_name, void *raw_data)
2910 {
2911         struct nfs_mount_info mount_info = {
2912                 .fill_super = nfs4_clone_super,
2913                 .set_security = nfs_clone_sb_security,
2914                 .cloned = raw_data,
2915         };
2916         return nfs_xdev_mount_common(&nfs4_fs_type, flags, dev_name, &mount_info);
2917 }
2918
2919 static struct dentry *
2920 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2921                            const char *dev_name, void *raw_data)
2922 {
2923         struct nfs_clone_mount *data = raw_data;
2924         struct super_block *s;
2925         struct nfs_server *server;
2926         struct dentry *mntroot;
2927         struct nfs_fh *mntfh;
2928         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2929         struct nfs_sb_mountdata sb_mntdata = {
2930                 .mntflags = flags,
2931         };
2932         int error = -ENOMEM;
2933
2934         dprintk("--> nfs4_referral_get_sb()\n");
2935
2936         mntfh = nfs_alloc_fhandle();
2937         if (mntfh == NULL)
2938                 goto out_err_nofh;
2939
2940         /* create a new volume representation */
2941         server = nfs4_create_referral_server(data, mntfh);
2942         if (IS_ERR(server)) {
2943                 error = PTR_ERR(server);
2944                 goto out_err_noserver;
2945         }
2946         sb_mntdata.server = server;
2947
2948         if (server->flags & NFS_MOUNT_UNSHARED)
2949                 compare_super = NULL;
2950
2951         /* -o noac implies -o sync */
2952         if (server->flags & NFS_MOUNT_NOAC)
2953                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2954
2955         /* Get a superblock - note that we may end up sharing one that already exists */
2956         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2957         if (IS_ERR(s)) {
2958                 error = PTR_ERR(s);
2959                 goto out_err_nosb;
2960         }
2961
2962         if (s->s_fs_info != server) {
2963                 nfs_free_server(server);
2964                 server = NULL;
2965         } else {
2966                 error = nfs_bdi_register(server);
2967                 if (error)
2968                         goto error_splat_bdi;
2969         }
2970
2971         if (!s->s_root) {
2972                 /* initial superblock/root creation */
2973                 nfs4_fill_super(s, NULL);
2974                 nfs_get_cache_cookie(s, NULL, data);
2975         }
2976
2977         mntroot = nfs_get_root(s, mntfh, dev_name);
2978         if (IS_ERR(mntroot)) {
2979                 error = PTR_ERR(mntroot);
2980                 goto error_splat_super;
2981         }
2982         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2983                 dput(mntroot);
2984                 error = -ESTALE;
2985                 goto error_splat_super;
2986         }
2987
2988         s->s_flags |= MS_ACTIVE;
2989
2990         security_sb_clone_mnt_opts(data->sb, s);
2991
2992         nfs_free_fhandle(mntfh);
2993         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2994         return mntroot;
2995
2996 out_err_nosb:
2997         nfs_free_server(server);
2998 out_err_noserver:
2999         nfs_free_fhandle(mntfh);
3000 out_err_nofh:
3001         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3002         return ERR_PTR(error);
3003
3004 error_splat_super:
3005         if (server && !s->s_root)
3006                 bdi_unregister(&server->backing_dev_info);
3007 error_splat_bdi:
3008         deactivate_locked_super(s);
3009         nfs_free_fhandle(mntfh);
3010         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3011         return ERR_PTR(error);
3012 }
3013
3014 /*
3015  * Create an NFS4 server record on referral traversal
3016  */
3017 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3018                 int flags, const char *dev_name, void *raw_data)
3019 {
3020         struct nfs_clone_mount *data = raw_data;
3021         char *export_path;
3022         struct vfsmount *root_mnt;
3023         struct dentry *res;
3024
3025         dprintk("--> nfs4_referral_mount()\n");
3026
3027         export_path = data->mnt_path;
3028         data->mnt_path = "/";
3029
3030         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3031                         flags, data, data->hostname);
3032         data->mnt_path = export_path;
3033
3034         res = nfs_follow_remote_path(root_mnt, export_path);
3035         dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3036                         IS_ERR(res) ? PTR_ERR(res) : 0,
3037                         IS_ERR(res) ? " [error]" : "");
3038         return res;
3039 }
3040
3041 #endif /* CONFIG_NFS_V4 */