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/addr.h>
  35 #include <linux/sunrpc/stats.h>
  36 #include <linux/sunrpc/metrics.h>
  37 #include <linux/sunrpc/xprtsock.h>
  38 #include <linux/sunrpc/xprtrdma.h>
  39 #include <linux/nfs_fs.h>
  40 #include <linux/nfs_mount.h>
  41 #include <linux/nfs4_mount.h>
  42 #include <linux/lockd/bind.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/namei.h>
  46 #include <linux/nfs_idmap.h>
  47 #include <linux/vfs.h>
  48 #include <linux/inet.h>
  49 #include <linux/in6.h>
  50 #include <linux/slab.h>
  51 #include <net/ipv6.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/nfs_xdr.h>
  54 #include <linux/magic.h>
  55 #include <linux/parser.h>
  56 #include <linux/nsproxy.h>
  57 #include <linux/rcupdate.h>
  58
  59 #include <asm/uaccess.h>
  60
  61 #include "nfs4_fs.h"
  62 #include "callback.h"
  63 #include "delegation.h"
  64 #include "iostat.h"
  65 #include "internal.h"
  66 #include "fscache.h"
  67 #include "nfs4session.h"
  68 #include "pnfs.h"
  69 #include "nfs.h"
  70
  71 #define NFSDBG_FACILITY         NFSDBG_VFS
  72 #define NFS_TEXT_DATA           1
  73
  74 #if IS_ENABLED(CONFIG_NFS_V3)
  75 #define NFS_DEFAULT_VERSION 3
  76 #else
  77 #define NFS_DEFAULT_VERSION 2
  78 #endif
  79
  80 enum {
  81         /* Mount options that take no arguments */
  82         Opt_soft, Opt_hard,
  83         Opt_posix, Opt_noposix,
  84         Opt_cto, Opt_nocto,
  85         Opt_ac, Opt_noac,
  86         Opt_lock, Opt_nolock,
  87         Opt_udp, Opt_tcp, Opt_rdma,
  88         Opt_acl, Opt_noacl,
  89         Opt_rdirplus, Opt_nordirplus,
  90         Opt_sharecache, Opt_nosharecache,
  91         Opt_resvport, Opt_noresvport,
  92         Opt_fscache, Opt_nofscache,
  93         Opt_migration, Opt_nomigration,
  94
  95         /* Mount options that take integer arguments */
  96         Opt_port,
  97         Opt_rsize, Opt_wsize, Opt_bsize,
  98         Opt_timeo, Opt_retrans,
  99         Opt_acregmin, Opt_acregmax,
 100         Opt_acdirmin, Opt_acdirmax,
 101         Opt_actimeo,
 102         Opt_namelen,
 103         Opt_mountport,
 104         Opt_mountvers,
 105         Opt_minorversion,
 106
 107         /* Mount options that take string arguments */
 108         Opt_nfsvers,
 109         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 110         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 111         Opt_lookupcache,
 112         Opt_fscache_uniq,
 113         Opt_local_lock,
 114
 115         /* Special mount options */
 116         Opt_userspace, Opt_deprecated, Opt_sloppy,
 117
 118         Opt_err
 119 };
 120
 121 static const match_table_t nfs_mount_option_tokens = {
 122         { Opt_userspace, "bg" },
 123         { Opt_userspace, "fg" },
 124         { Opt_userspace, "retry=%s" },
 125
 126         { Opt_sloppy, "sloppy" },
 127
 128         { Opt_soft, "soft" },
 129         { Opt_hard, "hard" },
 130         { Opt_deprecated, "intr" },
 131         { Opt_deprecated, "nointr" },
 132         { Opt_posix, "posix" },
 133         { Opt_noposix, "noposix" },
 134         { Opt_cto, "cto" },
 135         { Opt_nocto, "nocto" },
 136         { Opt_ac, "ac" },
 137         { Opt_noac, "noac" },
 138         { Opt_lock, "lock" },
 139         { Opt_nolock, "nolock" },
 140         { Opt_udp, "udp" },
 141         { Opt_tcp, "tcp" },
 142         { Opt_rdma, "rdma" },
 143         { Opt_acl, "acl" },
 144         { Opt_noacl, "noacl" },
 145         { Opt_rdirplus, "rdirplus" },
 146         { Opt_nordirplus, "nordirplus" },
 147         { Opt_sharecache, "sharecache" },
 148         { Opt_nosharecache, "nosharecache" },
 149         { Opt_resvport, "resvport" },
 150         { Opt_noresvport, "noresvport" },
 151         { Opt_fscache, "fsc" },
 152         { Opt_nofscache, "nofsc" },
 153         { Opt_migration, "migration" },
 154         { Opt_nomigration, "nomigration" },
 155
 156         { Opt_port, "port=%s" },
 157         { Opt_rsize, "rsize=%s" },
 158         { Opt_wsize, "wsize=%s" },
 159         { Opt_bsize, "bsize=%s" },
 160         { Opt_timeo, "timeo=%s" },
 161         { Opt_retrans, "retrans=%s" },
 162         { Opt_acregmin, "acregmin=%s" },
 163         { Opt_acregmax, "acregmax=%s" },
 164         { Opt_acdirmin, "acdirmin=%s" },
 165         { Opt_acdirmax, "acdirmax=%s" },
 166         { Opt_actimeo, "actimeo=%s" },
 167         { Opt_namelen, "namlen=%s" },
 168         { Opt_mountport, "mountport=%s" },
 169         { Opt_mountvers, "mountvers=%s" },
 170         { Opt_minorversion, "minorversion=%s" },
 171
 172         { Opt_nfsvers, "nfsvers=%s" },
 173         { Opt_nfsvers, "vers=%s" },
 174
 175         { Opt_sec, "sec=%s" },
 176         { Opt_proto, "proto=%s" },
 177         { Opt_mountproto, "mountproto=%s" },
 178         { Opt_addr, "addr=%s" },
 179         { Opt_clientaddr, "clientaddr=%s" },
 180         { Opt_mounthost, "mounthost=%s" },
 181         { Opt_mountaddr, "mountaddr=%s" },
 182
 183         { Opt_lookupcache, "lookupcache=%s" },
 184         { Opt_fscache_uniq, "fsc=%s" },
 185         { Opt_local_lock, "local_lock=%s" },
 186
 187         /* The following needs to be listed after all other options */
 188         { Opt_nfsvers, "v%s" },
 189
 190         { Opt_err, NULL }
 191 };
 192
 193 enum {
 194         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 195
 196         Opt_xprt_err
 197 };
 198
 199 static const match_table_t nfs_xprt_protocol_tokens = {
 200         { Opt_xprt_udp, "udp" },
 201         { Opt_xprt_udp6, "udp6" },
 202         { Opt_xprt_tcp, "tcp" },
 203         { Opt_xprt_tcp6, "tcp6" },
 204         { Opt_xprt_rdma, "rdma" },
 205
 206         { Opt_xprt_err, NULL }
 207 };
 208
 209 enum {
 210         Opt_sec_none, Opt_sec_sys,
 211         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 212         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 213         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 214
 215         Opt_sec_err
 216 };
 217
 218 static const match_table_t nfs_secflavor_tokens = {
 219         { Opt_sec_none, "none" },
 220         { Opt_sec_none, "null" },
 221         { Opt_sec_sys, "sys" },
 222
 223         { Opt_sec_krb5, "krb5" },
 224         { Opt_sec_krb5i, "krb5i" },
 225         { Opt_sec_krb5p, "krb5p" },
 226
 227         { Opt_sec_lkey, "lkey" },
 228         { Opt_sec_lkeyi, "lkeyi" },
 229         { Opt_sec_lkeyp, "lkeyp" },
 230
 231         { Opt_sec_spkm, "spkm3" },
 232         { Opt_sec_spkmi, "spkm3i" },
 233         { Opt_sec_spkmp, "spkm3p" },
 234
 235         { Opt_sec_err, NULL }
 236 };
 237
 238 enum {
 239         Opt_lookupcache_all, Opt_lookupcache_positive,
 240         Opt_lookupcache_none,
 241
 242         Opt_lookupcache_err
 243 };
 244
 245 static match_table_t nfs_lookupcache_tokens = {
 246         { Opt_lookupcache_all, "all" },
 247         { Opt_lookupcache_positive, "pos" },
 248         { Opt_lookupcache_positive, "positive" },
 249         { Opt_lookupcache_none, "none" },
 250
 251         { Opt_lookupcache_err, NULL }
 252 };
 253
 254 enum {
 255         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 256         Opt_local_lock_none,
 257
 258         Opt_local_lock_err
 259 };
 260
 261 static match_table_t nfs_local_lock_tokens = {
 262         { Opt_local_lock_all, "all" },
 263         { Opt_local_lock_flock, "flock" },
 264         { Opt_local_lock_posix, "posix" },
 265         { Opt_local_lock_none, "none" },
 266
 267         { Opt_local_lock_err, NULL }
 268 };
 269
 270 enum {
 271         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 272         Opt_vers_4_1, Opt_vers_4_2,
 273
 274         Opt_vers_err
 275 };
 276
 277 static match_table_t nfs_vers_tokens = {
 278         { Opt_vers_2, "2" },
 279         { Opt_vers_3, "3" },
 280         { Opt_vers_4, "4" },
 281         { Opt_vers_4_0, "4.0" },
 282         { Opt_vers_4_1, "4.1" },
 283         { Opt_vers_4_2, "4.2" },
 284
 285         { Opt_vers_err, NULL }
 286 };
 287
 288 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 289                 int flags, const char *dev_name, void *raw_data);
 290
 291 struct file_system_type nfs_fs_type = {
 292         .owner          = THIS_MODULE,
 293         .name           = "nfs",
 294         .mount          = nfs_fs_mount,
 295         .kill_sb        = nfs_kill_super,
 296         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 297 };
 298 MODULE_ALIAS_FS("nfs");
 299 EXPORT_SYMBOL_GPL(nfs_fs_type);
 300
 301 struct file_system_type nfs_xdev_fs_type = {
 302         .owner          = THIS_MODULE,
 303         .name           = "nfs",
 304         .mount          = nfs_xdev_mount,
 305         .kill_sb        = nfs_kill_super,
 306         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 307 };
 308
 309 const struct super_operations nfs_sops = {
 310         .alloc_inode    = nfs_alloc_inode,
 311         .destroy_inode  = nfs_destroy_inode,
 312         .write_inode    = nfs_write_inode,
 313         .drop_inode     = nfs_drop_inode,
 314         .put_super      = nfs_put_super,
 315         .statfs         = nfs_statfs,
 316         .evict_inode    = nfs_evict_inode,
 317         .umount_begin   = nfs_umount_begin,
 318         .show_options   = nfs_show_options,
 319         .show_devname   = nfs_show_devname,
 320         .show_path      = nfs_show_path,
 321         .show_stats     = nfs_show_stats,
 322         .remount_fs     = nfs_remount,
 323 };
 324 EXPORT_SYMBOL_GPL(nfs_sops);
 325
 326 #if IS_ENABLED(CONFIG_NFS_V4)
 327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
 328 static int nfs4_validate_mount_data(void *options,
 329         struct nfs_parsed_mount_data *args, const char *dev_name);
 330
 331 struct file_system_type nfs4_fs_type = {
 332         .owner          = THIS_MODULE,
 333         .name           = "nfs4",
 334         .mount          = nfs_fs_mount,
 335         .kill_sb        = nfs_kill_super,
 336         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 337 };
 338 MODULE_ALIAS_FS("nfs4");
 339 MODULE_ALIAS("nfs4");
 340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 341
 342 static int __init register_nfs4_fs(void)
 343 {
 344         return register_filesystem(&nfs4_fs_type);
 345 }
 346
 347 static void unregister_nfs4_fs(void)
 348 {
 349         unregister_filesystem(&nfs4_fs_type);
 350 }
 351 #else
 352 static int __init register_nfs4_fs(void)
 353 {
 354         return 0;
 355 }
 356
 357 static void unregister_nfs4_fs(void)
 358 {
 359 }
 360 #endif
 361
 362 static struct shrinker acl_shrinker = {
 363         .count_objects  = nfs_access_cache_count,
 364         .scan_objects   = nfs_access_cache_scan,
 365         .seeks          = DEFAULT_SEEKS,
 366 };
 367
 368 /*
 369  * Register the NFS filesystems
 370  */
 371 int __init register_nfs_fs(void)
 372 {
 373         int ret;
 374
 375         ret = register_filesystem(&nfs_fs_type);
 376         if (ret < 0)
 377                 goto error_0;
 378
 379         ret = register_nfs4_fs();
 380         if (ret < 0)
 381                 goto error_1;
 382
 383         ret = nfs_register_sysctl();
 384         if (ret < 0)
 385                 goto error_2;
 386         register_shrinker(&acl_shrinker);
 387         return 0;
 388
 389 error_2:
 390         unregister_nfs4_fs();
 391 error_1:
 392         unregister_filesystem(&nfs_fs_type);
 393 error_0:
 394         return ret;
 395 }
 396
 397 /*
 398  * Unregister the NFS filesystems
 399  */
 400 void __exit unregister_nfs_fs(void)
 401 {
 402         unregister_shrinker(&acl_shrinker);
 403         nfs_unregister_sysctl();
 404         unregister_nfs4_fs();
 405         unregister_filesystem(&nfs_fs_type);
 406 }
 407
 408 void nfs_sb_active(struct super_block *sb)
 409 {
 410         struct nfs_server *server = NFS_SB(sb);
 411
 412         if (atomic_inc_return(&server->active) == 1)
 413                 atomic_inc(&sb->s_active);
 414 }
 415 EXPORT_SYMBOL_GPL(nfs_sb_active);
 416
 417 void nfs_sb_deactive(struct super_block *sb)
 418 {
 419         struct nfs_server *server = NFS_SB(sb);
 420
 421         if (atomic_dec_and_test(&server->active))
 422                 deactivate_super(sb);
 423 }
 424 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
 425
 426 /*
 427  * Deliver file system statistics to userspace
 428  */
 429 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 430 {
 431         struct nfs_server *server = NFS_SB(dentry->d_sb);
 432         unsigned char blockbits;
 433         unsigned long blockres;
 434         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 435         struct nfs_fsstat res;
 436         int error = -ENOMEM;
 437
 438         res.fattr = nfs_alloc_fattr();
 439         if (res.fattr == NULL)
 440                 goto out_err;
 441
 442         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 443         if (unlikely(error == -ESTALE)) {
 444                 struct dentry *pd_dentry;
 445
 446                 pd_dentry = dget_parent(dentry);
 447                 if (pd_dentry != NULL) {
 448                         nfs_zap_caches(pd_dentry->d_inode);
 449                         dput(pd_dentry);
 450                 }
 451         }
 452         nfs_free_fattr(res.fattr);
 453         if (error < 0)
 454                 goto out_err;
 455
 456         buf->f_type = NFS_SUPER_MAGIC;
 457
 458         /*
 459          * Current versions of glibc do not correctly handle the
 460          * case where f_frsize != f_bsize.  Eventually we want to
 461          * report the value of wtmult in this field.
 462          */
 463         buf->f_frsize = dentry->d_sb->s_blocksize;
 464
 465         /*
 466          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 467          * are reported in units of f_frsize.  Linux hasn't had
 468          * an f_frsize field in its statfs struct until recently,
 469          * thus historically Linux's sys_statfs reports these
 470          * fields in units of f_bsize.
 471          */
 472         buf->f_bsize = dentry->d_sb->s_blocksize;
 473         blockbits = dentry->d_sb->s_blocksize_bits;
 474         blockres = (1 << blockbits) - 1;
 475         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 476         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 477         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 478
 479         buf->f_files = res.tfiles;
 480         buf->f_ffree = res.afiles;
 481
 482         buf->f_namelen = server->namelen;
 483
 484         return 0;
 485
 486  out_err:
 487         dprintk("%s: statfs error = %d\n", __func__, -error);
 488         return error;
 489 }
 490 EXPORT_SYMBOL_GPL(nfs_statfs);
 491
 492 /*
 493  * Map the security flavour number to a name
 494  */
 495 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 496 {
 497         static const struct {
 498                 rpc_authflavor_t flavour;
 499                 const char *str;
 500         } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
 501                 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
 502                 { RPC_AUTH_NULL, "null" },
 503                 { RPC_AUTH_UNIX, "sys" },
 504                 { RPC_AUTH_GSS_KRB5, "krb5" },
 505                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 506                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 507                 { RPC_AUTH_GSS_LKEY, "lkey" },
 508                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 509                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 510                 { RPC_AUTH_GSS_SPKM, "spkm" },
 511                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 512                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 513                 { UINT_MAX, "unknown" }
 514         };
 515         int i;
 516
 517         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 518                 if (sec_flavours[i].flavour == flavour)
 519                         break;
 520         }
 521         return sec_flavours[i].str;
 522 }
 523
 524 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 525                                   int showdefaults)
 526 {
 527         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 528
 529         seq_printf(m, ",mountproto=");
 530         switch (sap->sa_family) {
 531         case AF_INET:
 532                 switch (nfss->mountd_protocol) {
 533                 case IPPROTO_UDP:
 534                         seq_printf(m, RPCBIND_NETID_UDP);
 535                         break;
 536                 case IPPROTO_TCP:
 537                         seq_printf(m, RPCBIND_NETID_TCP);
 538                         break;
 539                 default:
 540                         if (showdefaults)
 541                                 seq_printf(m, "auto");
 542                 }
 543                 break;
 544         case AF_INET6:
 545                 switch (nfss->mountd_protocol) {
 546                 case IPPROTO_UDP:
 547                         seq_printf(m, RPCBIND_NETID_UDP6);
 548                         break;
 549                 case IPPROTO_TCP:
 550                         seq_printf(m, RPCBIND_NETID_TCP6);
 551                         break;
 552                 default:
 553                         if (showdefaults)
 554                                 seq_printf(m, "auto");
 555                 }
 556                 break;
 557         default:
 558                 if (showdefaults)
 559                         seq_printf(m, "auto");
 560         }
 561 }
 562
 563 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 564                                     int showdefaults)
 565 {
 566         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 567
 568         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 569                 return;
 570
 571         switch (sap->sa_family) {
 572         case AF_INET: {
 573                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 574                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 575                 break;
 576         }
 577         case AF_INET6: {
 578                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 579                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 580                 break;
 581         }
 582         default:
 583                 if (showdefaults)
 584                         seq_printf(m, ",mountaddr=unspecified");
 585         }
 586
 587         if (nfss->mountd_version || showdefaults)
 588                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 589         if ((nfss->mountd_port &&
 590                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 591                 showdefaults)
 592                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 593
 594         nfs_show_mountd_netid(m, nfss, showdefaults);
 595 }
 596
 597 #if IS_ENABLED(CONFIG_NFS_V4)
 598 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 599                                     int showdefaults)
 600 {
 601         struct nfs_client *clp = nfss->nfs_client;
 602
 603         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 604 }
 605 #else
 606 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 607                                     int showdefaults)
 608 {
 609 }
 610 #endif
 611
 612 static void nfs_show_nfs_version(struct seq_file *m,
 613                 unsigned int version,
 614                 unsigned int minorversion)
 615 {
 616         seq_printf(m, ",vers=%u", version);
 617         if (version == 4)
 618                 seq_printf(m, ".%u", minorversion);
 619 }
 620
 621 /*
 622  * Describe the mount options in force on this server representation
 623  */
 624 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 625                                    int showdefaults)
 626 {
 627         static const struct proc_nfs_info {
 628                 int flag;
 629                 const char *str;
 630                 const char *nostr;
 631         } nfs_info[] = {
 632                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 633                 { NFS_MOUNT_POSIX, ",posix", "" },
 634                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 635                 { NFS_MOUNT_NOAC, ",noac", "" },
 636                 { NFS_MOUNT_NONLM, ",nolock", "" },
 637                 { NFS_MOUNT_NOACL, ",noacl", "" },
 638                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 639                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 640                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 641                 { 0, NULL, NULL }
 642         };
 643         const struct proc_nfs_info *nfs_infop;
 644         struct nfs_client *clp = nfss->nfs_client;
 645         u32 version = clp->rpc_ops->version;
 646         int local_flock, local_fcntl;
 647
 648         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 649         seq_printf(m, ",rsize=%u", nfss->rsize);
 650         seq_printf(m, ",wsize=%u", nfss->wsize);
 651         if (nfss->bsize != 0)
 652                 seq_printf(m, ",bsize=%u", nfss->bsize);
 653         seq_printf(m, ",namlen=%u", nfss->namelen);
 654         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 655                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 656         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 657                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 658         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 659                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 660         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 661                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 662         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 663                 if (nfss->flags & nfs_infop->flag)
 664                         seq_puts(m, nfs_infop->str);
 665                 else
 666                         seq_puts(m, nfs_infop->nostr);
 667         }
 668         rcu_read_lock();
 669         seq_printf(m, ",proto=%s",
 670                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 671         rcu_read_unlock();
 672         if (version == 4) {
 673                 if (nfss->port != NFS_PORT)
 674                         seq_printf(m, ",port=%u", nfss->port);
 675         } else
 676                 if (nfss->port)
 677                         seq_printf(m, ",port=%u", nfss->port);
 678
 679         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 680         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 681         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 682
 683         if (version != 4)
 684                 nfs_show_mountd_options(m, nfss, showdefaults);
 685         else
 686                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 687
 688         if (nfss->options & NFS_OPTION_FSCACHE)
 689                 seq_printf(m, ",fsc");
 690
 691         if (nfss->options & NFS_OPTION_MIGRATION)
 692                 seq_printf(m, ",migration");
 693
 694         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 695                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 696                         seq_printf(m, ",lookupcache=none");
 697                 else
 698                         seq_printf(m, ",lookupcache=pos");
 699         }
 700
 701         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 702         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 703
 704         if (!local_flock && !local_fcntl)
 705                 seq_printf(m, ",local_lock=none");
 706         else if (local_flock && local_fcntl)
 707                 seq_printf(m, ",local_lock=all");
 708         else if (local_flock)
 709                 seq_printf(m, ",local_lock=flock");
 710         else
 711                 seq_printf(m, ",local_lock=posix");
 712 }
 713
 714 /*
 715  * Describe the mount options on this VFS mountpoint
 716  */
 717 int nfs_show_options(struct seq_file *m, struct dentry *root)
 718 {
 719         struct nfs_server *nfss = NFS_SB(root->d_sb);
 720
 721         nfs_show_mount_options(m, nfss, 0);
 722
 723         rcu_read_lock();
 724         seq_printf(m, ",addr=%s",
 725                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 726                                                         RPC_DISPLAY_ADDR));
 727         rcu_read_unlock();
 728
 729         return 0;
 730 }
 731 EXPORT_SYMBOL_GPL(nfs_show_options);
 732
 733 #if IS_ENABLED(CONFIG_NFS_V4)
 734 #ifdef CONFIG_NFS_V4_1
 735 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 736 {
 737         if (nfs4_has_session(server->nfs_client))
 738                 seq_printf(m, ",sessions");
 739 }
 740 #else
 741 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 742 #endif
 743 #endif
 744
 745 #ifdef CONFIG_NFS_V4_1
 746 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 747 {
 748         seq_printf(m, ",pnfs=");
 749         if (server->pnfs_curr_ld)
 750                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 751         else
 752                 seq_printf(m, "not configured");
 753 }
 754
 755 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 756 {
 757         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 758                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 759                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 760                            "date='%llu,%u'",
 761                            impl_id->name, impl_id->domain,
 762                            impl_id->date.seconds, impl_id->date.nseconds);
 763         }
 764 }
 765 #else
 766 #if IS_ENABLED(CONFIG_NFS_V4)
 767 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 768 {
 769 }
 770 #endif
 771 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 772 {
 773 }
 774 #endif
 775
 776 int nfs_show_devname(struct seq_file *m, struct dentry *root)
 777 {
 778         char *page = (char *) __get_free_page(GFP_KERNEL);
 779         char *devname, *dummy;
 780         int err = 0;
 781         if (!page)
 782                 return -ENOMEM;
 783         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
 784         if (IS_ERR(devname))
 785                 err = PTR_ERR(devname);
 786         else
 787                 seq_escape(m, devname, " \t\n\\");
 788         free_page((unsigned long)page);
 789         return err;
 790 }
 791 EXPORT_SYMBOL_GPL(nfs_show_devname);
 792
 793 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 794 {
 795         seq_puts(m, "/");
 796         return 0;
 797 }
 798 EXPORT_SYMBOL_GPL(nfs_show_path);
 799
 800 /*
 801  * Present statistical information for this VFS mountpoint
 802  */
 803 int nfs_show_stats(struct seq_file *m, struct dentry *root)
 804 {
 805         int i, cpu;
 806         struct nfs_server *nfss = NFS_SB(root->d_sb);
 807         struct rpc_auth *auth = nfss->client->cl_auth;
 808         struct nfs_iostats totals = { };
 809
 810         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 811
 812         /*
 813          * Display all mount option settings
 814          */
 815         seq_printf(m, "\n\topts:\t");
 816         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 817         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 818         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 819         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 820         nfs_show_mount_options(m, nfss, 1);
 821
 822         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 823
 824         show_implementation_id(m, nfss);
 825
 826         seq_printf(m, "\n\tcaps:\t");
 827         seq_printf(m, "caps=0x%x", nfss->caps);
 828         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 829         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 830         seq_printf(m, ",bsize=%u", nfss->bsize);
 831         seq_printf(m, ",namlen=%u", nfss->namelen);
 832
 833 #if IS_ENABLED(CONFIG_NFS_V4)
 834         if (nfss->nfs_client->rpc_ops->version == 4) {
 835                 seq_printf(m, "\n\tnfsv4:\t");
 836                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 837                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 838                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
 839                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 840                 show_sessions(m, nfss);
 841                 show_pnfs(m, nfss);
 842         }
 843 #endif
 844
 845         /*
 846          * Display security flavor in effect for this mount
 847          */
 848         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 849         if (auth->au_flavor)
 850                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 851
 852         /*
 853          * Display superblock I/O counters
 854          */
 855         for_each_possible_cpu(cpu) {
 856                 struct nfs_iostats *stats;
 857
 858                 preempt_disable();
 859                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 860
 861                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 862                         totals.events[i] += stats->events[i];
 863                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 864                         totals.bytes[i] += stats->bytes[i];
 865 #ifdef CONFIG_NFS_FSCACHE
 866                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 867                         totals.fscache[i] += stats->fscache[i];
 868 #endif
 869
 870                 preempt_enable();
 871         }
 872
 873         seq_printf(m, "\n\tevents:\t");
 874         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 875                 seq_printf(m, "%lu ", totals.events[i]);
 876         seq_printf(m, "\n\tbytes:\t");
 877         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 878                 seq_printf(m, "%Lu ", totals.bytes[i]);
 879 #ifdef CONFIG_NFS_FSCACHE
 880         if (nfss->options & NFS_OPTION_FSCACHE) {
 881                 seq_printf(m, "\n\tfsc:\t");
 882                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 883                         seq_printf(m, "%Lu ", totals.bytes[i]);
 884         }
 885 #endif
 886         seq_printf(m, "\n");
 887
 888         rpc_print_iostats(m, nfss->client);
 889
 890         return 0;
 891 }
 892 EXPORT_SYMBOL_GPL(nfs_show_stats);
 893
 894 /*
 895  * Begin unmount by attempting to remove all automounted mountpoints we added
 896  * in response to xdev traversals and referrals
 897  */
 898 void nfs_umount_begin(struct super_block *sb)
 899 {
 900         struct nfs_server *server;
 901         struct rpc_clnt *rpc;
 902
 903         server = NFS_SB(sb);
 904         /* -EIO all pending I/O */
 905         rpc = server->client_acl;
 906         if (!IS_ERR(rpc))
 907                 rpc_killall_tasks(rpc);
 908         rpc = server->client;
 909         if (!IS_ERR(rpc))
 910                 rpc_killall_tasks(rpc);
 911 }
 912 EXPORT_SYMBOL_GPL(nfs_umount_begin);
 913
 914 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 915 {
 916         struct nfs_parsed_mount_data *data;
 917
 918         data = kzalloc(sizeof(*data), GFP_KERNEL);
 919         if (data) {
 920                 data->acregmin          = NFS_DEF_ACREGMIN;
 921                 data->acregmax          = NFS_DEF_ACREGMAX;
 922                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 923                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 924                 data->mount_server.port = NFS_UNSPEC_PORT;
 925                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 926                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 927                 data->selected_flavor   = RPC_AUTH_MAXFLAVOR;
 928                 data->minorversion      = 0;
 929                 data->need_mount        = true;
 930                 data->net               = current->nsproxy->net_ns;
 931                 security_init_mnt_opts(&data->lsm_opts);
 932         }
 933         return data;
 934 }
 935
 936 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 937 {
 938         if (data) {
 939                 kfree(data->client_address);
 940                 kfree(data->mount_server.hostname);
 941                 kfree(data->nfs_server.export_path);
 942                 kfree(data->nfs_server.hostname);
 943                 kfree(data->fscache_uniq);
 944                 security_free_mnt_opts(&data->lsm_opts);
 945                 kfree(data);
 946         }
 947 }
 948
 949 /*
 950  * Sanity-check a server address provided by the mount command.
 951  *
 952  * Address family must be initialized, and address must not be
 953  * the ANY address for that family.
 954  */
 955 static int nfs_verify_server_address(struct sockaddr *addr)
 956 {
 957         switch (addr->sa_family) {
 958         case AF_INET: {
 959                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 960                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 961         }
 962         case AF_INET6: {
 963                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 964                 return !ipv6_addr_any(sa);
 965         }
 966         }
 967
 968         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 969         return 0;
 970 }
 971
 972 /*
 973  * Select between a default port value and a user-specified port value.
 974  * If a zero value is set, then autobind will be used.
 975  */
 976 static void nfs_set_port(struct sockaddr *sap, int *port,
 977                                  const unsigned short default_port)
 978 {
 979         if (*port == NFS_UNSPEC_PORT)
 980                 *port = default_port;
 981
 982         rpc_set_port(sap, *port);
 983 }
 984
 985 /*
 986  * Sanity check the NFS transport protocol.
 987  *
 988  */
 989 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 990 {
 991         switch (mnt->nfs_server.protocol) {
 992         case XPRT_TRANSPORT_UDP:
 993         case XPRT_TRANSPORT_TCP:
 994         case XPRT_TRANSPORT_RDMA:
 995                 break;
 996         default:
 997                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 998         }
 999 }
1000
1001 /*
1002  * For text based NFSv2/v3 mounts, the mount protocol transport default
1003  * settings should depend upon the specified NFS transport.
1004  */
1005 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1006 {
1007         nfs_validate_transport_protocol(mnt);
1008
1009         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1010             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1011                         return;
1012         switch (mnt->nfs_server.protocol) {
1013         case XPRT_TRANSPORT_UDP:
1014                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1015                 break;
1016         case XPRT_TRANSPORT_TCP:
1017         case XPRT_TRANSPORT_RDMA:
1018                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1019         }
1020 }
1021
1022 /*
1023  * Add 'flavor' to 'auth_info' if not already present.
1024  * Returns true if 'flavor' ends up in the list, false otherwise
1025  */
1026 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1027                               rpc_authflavor_t flavor)
1028 {
1029         unsigned int i;
1030         unsigned int max_flavor_len = (sizeof(auth_info->flavors) /
1031                                        sizeof(auth_info->flavors[0]));
1032
1033         /* make sure this flavor isn't already in the list */
1034         for (i = 0; i < auth_info->flavor_len; i++) {
1035                 if (flavor == auth_info->flavors[i])
1036                         return true;
1037         }
1038
1039         if (auth_info->flavor_len + 1 >= max_flavor_len) {
1040                 dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1041                 return false;
1042         }
1043
1044         auth_info->flavors[auth_info->flavor_len++] = flavor;
1045         return true;
1046 }
1047
1048 /*
1049  * Return true if 'match' is in auth_info or auth_info is empty.
1050  * Return false otherwise.
1051  */
1052 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1053                          rpc_authflavor_t match)
1054 {
1055         int i;
1056
1057         if (!auth_info->flavor_len)
1058                 return true;
1059
1060         for (i = 0; i < auth_info->flavor_len; i++) {
1061                 if (auth_info->flavors[i] == match)
1062                         return true;
1063         }
1064         return false;
1065 }
1066 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1067
1068 /*
1069  * Parse the value of the 'sec=' option.
1070  */
1071 static int nfs_parse_security_flavors(char *value,
1072                                       struct nfs_parsed_mount_data *mnt)
1073 {
1074         substring_t args[MAX_OPT_ARGS];
1075         rpc_authflavor_t pseudoflavor;
1076         char *p;
1077
1078         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1079
1080         while ((p = strsep(&value, ":")) != NULL) {
1081                 switch (match_token(p, nfs_secflavor_tokens, args)) {
1082                 case Opt_sec_none:
1083                         pseudoflavor = RPC_AUTH_NULL;
1084                         break;
1085                 case Opt_sec_sys:
1086                         pseudoflavor = RPC_AUTH_UNIX;
1087                         break;
1088                 case Opt_sec_krb5:
1089                         pseudoflavor = RPC_AUTH_GSS_KRB5;
1090                         break;
1091                 case Opt_sec_krb5i:
1092                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
1093                         break;
1094                 case Opt_sec_krb5p:
1095                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
1096                         break;
1097                 case Opt_sec_lkey:
1098                         pseudoflavor = RPC_AUTH_GSS_LKEY;
1099                         break;
1100                 case Opt_sec_lkeyi:
1101                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
1102                         break;
1103                 case Opt_sec_lkeyp:
1104                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
1105                         break;
1106                 case Opt_sec_spkm:
1107                         pseudoflavor = RPC_AUTH_GSS_SPKM;
1108                         break;
1109                 case Opt_sec_spkmi:
1110                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
1111                         break;
1112                 case Opt_sec_spkmp:
1113                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
1114                         break;
1115                 default:
1116                         dfprintk(MOUNT,
1117                                  "NFS: sec= option '%s' not recognized\n", p);
1118                         return 0;
1119                 }
1120
1121                 if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1122                         return 0;
1123         }
1124
1125         return 1;
1126 }
1127
1128 static int nfs_parse_version_string(char *string,
1129                 struct nfs_parsed_mount_data *mnt,
1130                 substring_t *args)
1131 {
1132         mnt->flags &= ~NFS_MOUNT_VER3;
1133         switch (match_token(string, nfs_vers_tokens, args)) {
1134         case Opt_vers_2:
1135                 mnt->version = 2;
1136                 break;
1137         case Opt_vers_3:
1138                 mnt->flags |= NFS_MOUNT_VER3;
1139                 mnt->version = 3;
1140                 break;
1141         case Opt_vers_4:
1142                 /* Backward compatibility option. In future,
1143                  * the mount program should always supply
1144                  * a NFSv4 minor version number.
1145                  */
1146                 mnt->version = 4;
1147                 break;
1148         case Opt_vers_4_0:
1149                 mnt->version = 4;
1150                 mnt->minorversion = 0;
1151                 break;
1152         case Opt_vers_4_1:
1153                 mnt->version = 4;
1154                 mnt->minorversion = 1;
1155                 break;
1156         case Opt_vers_4_2:
1157                 mnt->version = 4;
1158                 mnt->minorversion = 2;
1159                 break;
1160         default:
1161                 return 0;
1162         }
1163         return 1;
1164 }
1165
1166 static int nfs_get_option_str(substring_t args[], char **option)
1167 {
1168         kfree(*option);
1169         *option = match_strdup(args);
1170         return !*option;
1171 }
1172
1173 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1174 {
1175         int rc;
1176         char *string;
1177
1178         string = match_strdup(args);
1179         if (string == NULL)
1180                 return -ENOMEM;
1181         rc = kstrtoul(string, 10, option);
1182         kfree(string);
1183
1184         return rc;
1185 }
1186
1187 /*
1188  * Error-check and convert a string of mount options from user space into
1189  * a data structure.  The whole mount string is processed; bad options are
1190  * skipped as they are encountered.  If there were no errors, return 1;
1191  * otherwise return 0 (zero).
1192  */
1193 static int nfs_parse_mount_options(char *raw,
1194                                    struct nfs_parsed_mount_data *mnt)
1195 {
1196         char *p, *string, *secdata;
1197         int rc, sloppy = 0, invalid_option = 0;
1198         unsigned short protofamily = AF_UNSPEC;
1199         unsigned short mountfamily = AF_UNSPEC;
1200
1201         if (!raw) {
1202                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1203                 return 1;
1204         }
1205         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1206
1207         secdata = alloc_secdata();
1208         if (!secdata)
1209                 goto out_nomem;
1210
1211         rc = security_sb_copy_data(raw, secdata);
1212         if (rc)
1213                 goto out_security_failure;
1214
1215         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1216         if (rc)
1217                 goto out_security_failure;
1218
1219         free_secdata(secdata);
1220
1221         while ((p = strsep(&raw, ",")) != NULL) {
1222                 substring_t args[MAX_OPT_ARGS];
1223                 unsigned long option;
1224                 int token;
1225
1226                 if (!*p)
1227                         continue;
1228
1229                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1230
1231                 token = match_token(p, nfs_mount_option_tokens, args);
1232                 switch (token) {
1233
1234                 /*
1235                  * boolean options:  foo/nofoo
1236                  */
1237                 case Opt_soft:
1238                         mnt->flags |= NFS_MOUNT_SOFT;
1239                         break;
1240                 case Opt_hard:
1241                         mnt->flags &= ~NFS_MOUNT_SOFT;
1242                         break;
1243                 case Opt_posix:
1244                         mnt->flags |= NFS_MOUNT_POSIX;
1245                         break;
1246                 case Opt_noposix:
1247                         mnt->flags &= ~NFS_MOUNT_POSIX;
1248                         break;
1249                 case Opt_cto:
1250                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1251                         break;
1252                 case Opt_nocto:
1253                         mnt->flags |= NFS_MOUNT_NOCTO;
1254                         break;
1255                 case Opt_ac:
1256                         mnt->flags &= ~NFS_MOUNT_NOAC;
1257                         break;
1258                 case Opt_noac:
1259                         mnt->flags |= NFS_MOUNT_NOAC;
1260                         break;
1261                 case Opt_lock:
1262                         mnt->flags &= ~NFS_MOUNT_NONLM;
1263                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1264                                         NFS_MOUNT_LOCAL_FCNTL);
1265                         break;
1266                 case Opt_nolock:
1267                         mnt->flags |= NFS_MOUNT_NONLM;
1268                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1269                                        NFS_MOUNT_LOCAL_FCNTL);
1270                         break;
1271                 case Opt_udp:
1272                         mnt->flags &= ~NFS_MOUNT_TCP;
1273                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1274                         break;
1275                 case Opt_tcp:
1276                         mnt->flags |= NFS_MOUNT_TCP;
1277                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1278                         break;
1279                 case Opt_rdma:
1280                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1281                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1282                         xprt_load_transport(p);
1283                         break;
1284                 case Opt_acl:
1285                         mnt->flags &= ~NFS_MOUNT_NOACL;
1286                         break;
1287                 case Opt_noacl:
1288                         mnt->flags |= NFS_MOUNT_NOACL;
1289                         break;
1290                 case Opt_rdirplus:
1291                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1292                         break;
1293                 case Opt_nordirplus:
1294                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1295                         break;
1296                 case Opt_sharecache:
1297                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1298                         break;
1299                 case Opt_nosharecache:
1300                         mnt->flags |= NFS_MOUNT_UNSHARED;
1301                         break;
1302                 case Opt_resvport:
1303                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1304                         break;
1305                 case Opt_noresvport:
1306                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1307                         break;
1308                 case Opt_fscache:
1309                         mnt->options |= NFS_OPTION_FSCACHE;
1310                         kfree(mnt->fscache_uniq);
1311                         mnt->fscache_uniq = NULL;
1312                         break;
1313                 case Opt_nofscache:
1314                         mnt->options &= ~NFS_OPTION_FSCACHE;
1315                         kfree(mnt->fscache_uniq);
1316                         mnt->fscache_uniq = NULL;
1317                         break;
1318                 case Opt_migration:
1319                         mnt->options |= NFS_OPTION_MIGRATION;
1320                         break;
1321                 case Opt_nomigration:
1322                         mnt->options &= NFS_OPTION_MIGRATION;
1323                         break;
1324
1325                 /*
1326                  * options that take numeric values
1327                  */
1328                 case Opt_port:
1329                         if (nfs_get_option_ul(args, &option) ||
1330                             option > USHRT_MAX)
1331                                 goto out_invalid_value;
1332                         mnt->nfs_server.port = option;
1333                         break;
1334                 case Opt_rsize:
1335                         if (nfs_get_option_ul(args, &option))
1336                                 goto out_invalid_value;
1337                         mnt->rsize = option;
1338                         break;
1339                 case Opt_wsize:
1340                         if (nfs_get_option_ul(args, &option))
1341                                 goto out_invalid_value;
1342                         mnt->wsize = option;
1343                         break;
1344                 case Opt_bsize:
1345                         if (nfs_get_option_ul(args, &option))
1346                                 goto out_invalid_value;
1347                         mnt->bsize = option;
1348                         break;
1349                 case Opt_timeo:
1350                         if (nfs_get_option_ul(args, &option) || option == 0)
1351                                 goto out_invalid_value;
1352                         mnt->timeo = option;
1353                         break;
1354                 case Opt_retrans:
1355                         if (nfs_get_option_ul(args, &option) || option == 0)
1356                                 goto out_invalid_value;
1357                         mnt->retrans = option;
1358                         break;
1359                 case Opt_acregmin:
1360                         if (nfs_get_option_ul(args, &option))
1361                                 goto out_invalid_value;
1362                         mnt->acregmin = option;
1363                         break;
1364                 case Opt_acregmax:
1365                         if (nfs_get_option_ul(args, &option))
1366                                 goto out_invalid_value;
1367                         mnt->acregmax = option;
1368                         break;
1369                 case Opt_acdirmin:
1370                         if (nfs_get_option_ul(args, &option))
1371                                 goto out_invalid_value;
1372                         mnt->acdirmin = option;
1373                         break;
1374                 case Opt_acdirmax:
1375                         if (nfs_get_option_ul(args, &option))
1376                                 goto out_invalid_value;
1377                         mnt->acdirmax = option;
1378                         break;
1379                 case Opt_actimeo:
1380                         if (nfs_get_option_ul(args, &option))
1381                                 goto out_invalid_value;
1382                         mnt->acregmin = mnt->acregmax =
1383                         mnt->acdirmin = mnt->acdirmax = option;
1384                         break;
1385                 case Opt_namelen:
1386                         if (nfs_get_option_ul(args, &option))
1387                                 goto out_invalid_value;
1388                         mnt->namlen = option;
1389                         break;
1390                 case Opt_mountport:
1391                         if (nfs_get_option_ul(args, &option) ||
1392                             option > USHRT_MAX)
1393                                 goto out_invalid_value;
1394                         mnt->mount_server.port = option;
1395                         break;
1396                 case Opt_mountvers:
1397                         if (nfs_get_option_ul(args, &option) ||
1398                             option < NFS_MNT_VERSION ||
1399                             option > NFS_MNT3_VERSION)
1400                                 goto out_invalid_value;
1401                         mnt->mount_server.version = option;
1402                         break;
1403                 case Opt_minorversion:
1404                         if (nfs_get_option_ul(args, &option))
1405                                 goto out_invalid_value;
1406                         if (option > NFS4_MAX_MINOR_VERSION)
1407                                 goto out_invalid_value;
1408                         mnt->minorversion = option;
1409                         break;
1410
1411                 /*
1412                  * options that take text values
1413                  */
1414                 case Opt_nfsvers:
1415                         string = match_strdup(args);
1416                         if (string == NULL)
1417                                 goto out_nomem;
1418                         rc = nfs_parse_version_string(string, mnt, args);
1419                         kfree(string);
1420                         if (!rc)
1421                                 goto out_invalid_value;
1422                         break;
1423                 case Opt_sec:
1424                         string = match_strdup(args);
1425                         if (string == NULL)
1426                                 goto out_nomem;
1427                         rc = nfs_parse_security_flavors(string, mnt);
1428                         kfree(string);
1429                         if (!rc) {
1430                                 dfprintk(MOUNT, "NFS:   unrecognized "
1431                                                 "security flavor\n");
1432                                 return 0;
1433                         }
1434                         break;
1435                 case Opt_proto:
1436                         string = match_strdup(args);
1437                         if (string == NULL)
1438                                 goto out_nomem;
1439                         token = match_token(string,
1440                                             nfs_xprt_protocol_tokens, args);
1441
1442                         protofamily = AF_INET;
1443                         switch (token) {
1444                         case Opt_xprt_udp6:
1445                                 protofamily = AF_INET6;
1446                         case Opt_xprt_udp:
1447                                 mnt->flags &= ~NFS_MOUNT_TCP;
1448                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1449                                 break;
1450                         case Opt_xprt_tcp6:
1451                                 protofamily = AF_INET6;
1452                         case Opt_xprt_tcp:
1453                                 mnt->flags |= NFS_MOUNT_TCP;
1454                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1455                                 break;
1456                         case Opt_xprt_rdma:
1457                                 /* vector side protocols to TCP */
1458                                 mnt->flags |= NFS_MOUNT_TCP;
1459                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1460                                 xprt_load_transport(string);
1461                                 break;
1462                         default:
1463                                 dfprintk(MOUNT, "NFS:   unrecognized "
1464                                                 "transport protocol\n");
1465                                 kfree(string);
1466                                 return 0;
1467                         }
1468                         kfree(string);
1469                         break;
1470                 case Opt_mountproto:
1471                         string = match_strdup(args);
1472                         if (string == NULL)
1473                                 goto out_nomem;
1474                         token = match_token(string,
1475                                             nfs_xprt_protocol_tokens, args);
1476                         kfree(string);
1477
1478                         mountfamily = AF_INET;
1479                         switch (token) {
1480                         case Opt_xprt_udp6:
1481                                 mountfamily = AF_INET6;
1482                         case Opt_xprt_udp:
1483                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1484                                 break;
1485                         case Opt_xprt_tcp6:
1486                                 mountfamily = AF_INET6;
1487                         case Opt_xprt_tcp:
1488                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1489                                 break;
1490                         case Opt_xprt_rdma: /* not used for side protocols */
1491                         default:
1492                                 dfprintk(MOUNT, "NFS:   unrecognized "
1493                                                 "transport protocol\n");
1494                                 return 0;
1495                         }
1496                         break;
1497                 case Opt_addr:
1498                         string = match_strdup(args);
1499                         if (string == NULL)
1500                                 goto out_nomem;
1501                         mnt->nfs_server.addrlen =
1502                                 rpc_pton(mnt->net, string, strlen(string),
1503                                         (struct sockaddr *)
1504                                         &mnt->nfs_server.address,
1505                                         sizeof(mnt->nfs_server.address));
1506                         kfree(string);
1507                         if (mnt->nfs_server.addrlen == 0)
1508                                 goto out_invalid_address;
1509                         break;
1510                 case Opt_clientaddr:
1511                         if (nfs_get_option_str(args, &mnt->client_address))
1512                                 goto out_nomem;
1513                         break;
1514                 case Opt_mounthost:
1515                         if (nfs_get_option_str(args,
1516                                                &mnt->mount_server.hostname))
1517                                 goto out_nomem;
1518                         break;
1519                 case Opt_mountaddr:
1520                         string = match_strdup(args);
1521                         if (string == NULL)
1522                                 goto out_nomem;
1523                         mnt->mount_server.addrlen =
1524                                 rpc_pton(mnt->net, string, strlen(string),
1525                                         (struct sockaddr *)
1526                                         &mnt->mount_server.address,
1527                                         sizeof(mnt->mount_server.address));
1528                         kfree(string);
1529                         if (mnt->mount_server.addrlen == 0)
1530                                 goto out_invalid_address;
1531                         break;
1532                 case Opt_lookupcache:
1533                         string = match_strdup(args);
1534                         if (string == NULL)
1535                                 goto out_nomem;
1536                         token = match_token(string,
1537                                         nfs_lookupcache_tokens, args);
1538                         kfree(string);
1539                         switch (token) {
1540                                 case Opt_lookupcache_all:
1541                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1542                                         break;
1543                                 case Opt_lookupcache_positive:
1544                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1545                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1546                                         break;
1547                                 case Opt_lookupcache_none:
1548                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1549                                         break;
1550                                 default:
1551                                         dfprintk(MOUNT, "NFS:   invalid "
1552                                                         "lookupcache argument\n");
1553                                         return 0;
1554                         };
1555                         break;
1556                 case Opt_fscache_uniq:
1557                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1558                                 goto out_nomem;
1559                         mnt->options |= NFS_OPTION_FSCACHE;
1560                         break;
1561                 case Opt_local_lock:
1562                         string = match_strdup(args);
1563                         if (string == NULL)
1564                                 goto out_nomem;
1565                         token = match_token(string, nfs_local_lock_tokens,
1566                                         args);
1567                         kfree(string);
1568                         switch (token) {
1569                         case Opt_local_lock_all:
1570                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1571                                                NFS_MOUNT_LOCAL_FCNTL);
1572                                 break;
1573                         case Opt_local_lock_flock:
1574                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1575                                 break;
1576                         case Opt_local_lock_posix:
1577                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1578                                 break;
1579                         case Opt_local_lock_none:
1580                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1581                                                 NFS_MOUNT_LOCAL_FCNTL);
1582                                 break;
1583                         default:
1584                                 dfprintk(MOUNT, "NFS:   invalid "
1585                                                 "local_lock argument\n");
1586                                 return 0;
1587                         };
1588                         break;
1589
1590                 /*
1591                  * Special options
1592                  */
1593                 case Opt_sloppy:
1594                         sloppy = 1;
1595                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1596                         break;
1597                 case Opt_userspace:
1598                 case Opt_deprecated:
1599                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1600                                         "'%s'\n", p);
1601                         break;
1602
1603                 default:
1604                         invalid_option = 1;
1605                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1606                                         "'%s'\n", p);
1607                 }
1608         }
1609
1610         if (!sloppy && invalid_option)
1611                 return 0;
1612
1613         if (mnt->minorversion && mnt->version != 4)
1614                 goto out_minorversion_mismatch;
1615
1616         if (mnt->options & NFS_OPTION_MIGRATION &&
1617             (mnt->version != 4 || mnt->minorversion != 0))
1618                 goto out_migration_misuse;
1619
1620         /*
1621          * verify that any proto=/mountproto= options match the address
1622          * families in the addr=/mountaddr= options.
1623          */
1624         if (protofamily != AF_UNSPEC &&
1625             protofamily != mnt->nfs_server.address.ss_family)
1626                 goto out_proto_mismatch;
1627
1628         if (mountfamily != AF_UNSPEC) {
1629                 if (mnt->mount_server.addrlen) {
1630                         if (mountfamily != mnt->mount_server.address.ss_family)
1631                                 goto out_mountproto_mismatch;
1632                 } else {
1633                         if (mountfamily != mnt->nfs_server.address.ss_family)
1634                                 goto out_mountproto_mismatch;
1635                 }
1636         }
1637
1638         return 1;
1639
1640 out_mountproto_mismatch:
1641         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1642                          "option\n");
1643         return 0;
1644 out_proto_mismatch:
1645         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1646         return 0;
1647 out_invalid_address:
1648         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1649         return 0;
1650 out_invalid_value:
1651         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1652         return 0;
1653 out_minorversion_mismatch:
1654         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1655                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1656         return 0;
1657 out_migration_misuse:
1658         printk(KERN_INFO
1659                 "NFS: 'migration' not supported for this NFS version\n");
1660         return 0;
1661 out_nomem:
1662         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1663         return 0;
1664 out_security_failure:
1665         free_secdata(secdata);
1666         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1667         return 0;
1668 }
1669
1670 /*
1671  * Ensure that a specified authtype in args->auth_info is supported by
1672  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1673  * -EACCES if not.
1674  */
1675 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1676                         rpc_authflavor_t *server_authlist, unsigned int count)
1677 {
1678         rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1679         unsigned int i;
1680
1681         /*
1682          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1683          * must be in the list returned by the server.
1684          *
1685          * AUTH_NULL has a special meaning when it's in the server list - it
1686          * means that the server will ignore the rpc creds, so any flavor
1687          * can be used.
1688          */
1689         for (i = 0; i < count; i++) {
1690                 flavor = server_authlist[i];
1691
1692                 if (nfs_auth_info_match(&args->auth_info, flavor) ||
1693                     flavor == RPC_AUTH_NULL)
1694                         goto out;
1695         }
1696
1697         dfprintk(MOUNT,
1698                  "NFS: specified auth flavors not supported by server\n");
1699         return -EACCES;
1700
1701 out:
1702         args->selected_flavor = flavor;
1703         dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1704         return 0;
1705 }
1706
1707 /*
1708  * Use the remote server's MOUNT service to request the NFS file handle
1709  * corresponding to the provided path.
1710  */
1711 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1712                              struct nfs_fh *root_fh,
1713                              rpc_authflavor_t *server_authlist,
1714                              unsigned int *server_authlist_len)
1715 {
1716         struct nfs_mount_request request = {
1717                 .sap            = (struct sockaddr *)
1718                                                 &args->mount_server.address,
1719                 .dirpath        = args->nfs_server.export_path,
1720                 .protocol       = args->mount_server.protocol,
1721                 .fh             = root_fh,
1722                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1723                 .auth_flav_len  = server_authlist_len,
1724                 .auth_flavs     = server_authlist,
1725                 .net            = args->net,
1726         };
1727         int status;
1728
1729         if (args->mount_server.version == 0) {
1730                 switch (args->version) {
1731                         default:
1732                                 args->mount_server.version = NFS_MNT3_VERSION;
1733                                 break;
1734                         case 2:
1735                                 args->mount_server.version = NFS_MNT_VERSION;
1736                 }
1737         }
1738         request.version = args->mount_server.version;
1739
1740         if (args->mount_server.hostname)
1741                 request.hostname = args->mount_server.hostname;
1742         else
1743                 request.hostname = args->nfs_server.hostname;
1744
1745         /*
1746          * Construct the mount server's address.
1747          */
1748         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1749                 memcpy(request.sap, &args->nfs_server.address,
1750                        args->nfs_server.addrlen);
1751                 args->mount_server.addrlen = args->nfs_server.addrlen;
1752         }
1753         request.salen = args->mount_server.addrlen;
1754         nfs_set_port(request.sap, &args->mount_server.port, 0);
1755
1756         /*
1757          * Now ask the mount server to map our export path
1758          * to a file handle.
1759          */
1760         status = nfs_mount(&request);
1761         if (status != 0) {
1762                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1763                                 request.hostname, status);
1764                 return status;
1765         }
1766
1767         return 0;
1768 }
1769
1770 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1771                                         struct nfs_subversion *nfs_mod)
1772 {
1773         int status;
1774         unsigned int i;
1775         bool tried_auth_unix = false;
1776         bool auth_null_in_list = false;
1777         struct nfs_server *server = ERR_PTR(-EACCES);
1778         struct nfs_parsed_mount_data *args = mount_info->parsed;
1779         rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1780         unsigned int authlist_len = ARRAY_SIZE(authlist);
1781
1782         status = nfs_request_mount(args, mount_info->mntfh, authlist,
1783                                         &authlist_len);
1784         if (status)
1785                 return ERR_PTR(status);
1786
1787         /*
1788          * Was a sec= authflavor specified in the options? First, verify
1789          * whether the server supports it, and then just try to use it if so.
1790          */
1791         if (args->auth_info.flavor_len > 0) {
1792                 status = nfs_verify_authflavors(args, authlist, authlist_len);
1793                 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1794                          args->selected_flavor);
1795                 if (status)
1796                         return ERR_PTR(status);
1797                 return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1798         }
1799
1800         /*
1801          * No sec= option was provided. RFC 2623, section 2.7 suggests we
1802          * SHOULD prefer the flavor listed first. However, some servers list
1803          * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1804          */
1805         for (i = 0; i < authlist_len; ++i) {
1806                 rpc_authflavor_t flavor;
1807                 struct rpcsec_gss_info info;
1808
1809                 flavor = authlist[i];
1810                 switch (flavor) {
1811                 case RPC_AUTH_UNIX:
1812                         tried_auth_unix = true;
1813                         break;
1814                 case RPC_AUTH_NULL:
1815                         auth_null_in_list = true;
1816                         continue;
1817                 default:
1818                         if (rpcauth_get_gssinfo(flavor, &info) != 0)
1819                                 continue;
1820                         /* Fallthrough */
1821                 }
1822                 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1823                 args->selected_flavor = flavor;
1824                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1825                 if (!IS_ERR(server))
1826                         return server;
1827         }
1828
1829         /*
1830          * Nothing we tried so far worked. At this point, give up if we've
1831          * already tried AUTH_UNIX or if the server's list doesn't contain
1832          * AUTH_NULL
1833          */
1834         if (tried_auth_unix || !auth_null_in_list)
1835                 return server;
1836
1837         /* Last chance! Try AUTH_UNIX */
1838         dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1839         args->selected_flavor = RPC_AUTH_UNIX;
1840         return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1841 }
1842
1843 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1844                              struct nfs_mount_info *mount_info,
1845                              struct nfs_subversion *nfs_mod)
1846 {
1847         struct nfs_server *server;
1848
1849         if (mount_info->parsed->need_mount)
1850                 server = nfs_try_mount_request(mount_info, nfs_mod);
1851         else
1852                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1853
1854         if (IS_ERR(server))
1855                 return ERR_CAST(server);
1856
1857         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1858 }
1859 EXPORT_SYMBOL_GPL(nfs_try_mount);
1860
1861 /*
1862  * Split "dev_name" into "hostname:export_path".
1863  *
1864  * The leftmost colon demarks the split between the server's hostname
1865  * and the export path.  If the hostname starts with a left square
1866  * bracket, then it may contain colons.
1867  *
1868  * Note: caller frees hostname and export path, even on error.
1869  */
1870 static int nfs_parse_devname(const char *dev_name,
1871                              char **hostname, size_t maxnamlen,
1872                              char **export_path, size_t maxpathlen)
1873 {
1874         size_t len;
1875         char *end;
1876
1877         /* Is the host name protected with square brakcets? */
1878         if (*dev_name == '[') {
1879                 end = strchr(++dev_name, ']');
1880                 if (end == NULL || end[1] != ':')
1881                         goto out_bad_devname;
1882
1883                 len = end - dev_name;
1884                 end++;
1885         } else {
1886                 char *comma;
1887
1888                 end = strchr(dev_name, ':');
1889                 if (end == NULL)
1890                         goto out_bad_devname;
1891                 len = end - dev_name;
1892
1893                 /* kill possible hostname list: not supported */
1894                 comma = strchr(dev_name, ',');
1895                 if (comma != NULL && comma < end)
1896                         *comma = 0;
1897         }
1898
1899         if (len > maxnamlen)
1900                 goto out_hostname;
1901
1902         /* N.B. caller will free nfs_server.hostname in all cases */
1903         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1904         if (*hostname == NULL)
1905                 goto out_nomem;
1906         len = strlen(++end);
1907         if (len > maxpathlen)
1908                 goto out_path;
1909         *export_path = kstrndup(end, len, GFP_KERNEL);
1910         if (!*export_path)
1911                 goto out_nomem;
1912
1913         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1914         return 0;
1915
1916 out_bad_devname:
1917         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1918         return -EINVAL;
1919
1920 out_nomem:
1921         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1922         return -ENOMEM;
1923
1924 out_hostname:
1925         dfprintk(MOUNT, "NFS: server hostname too long\n");
1926         return -ENAMETOOLONG;
1927
1928 out_path:
1929         dfprintk(MOUNT, "NFS: export pathname too long\n");
1930         return -ENAMETOOLONG;
1931 }
1932
1933 /*
1934  * Validate the NFS2/NFS3 mount data
1935  * - fills in the mount root filehandle
1936  *
1937  * For option strings, user space handles the following behaviors:
1938  *
1939  * + DNS: mapping server host name to IP address ("addr=" option)
1940  *
1941  * + failure mode: how to behave if a mount request can't be handled
1942  *   immediately ("fg/bg" option)
1943  *
1944  * + retry: how often to retry a mount request ("retry=" option)
1945  *
1946  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1947  *   mountproto=tcp after mountproto=udp, and so on
1948  */
1949 static int nfs23_validate_mount_data(void *options,
1950                                      struct nfs_parsed_mount_data *args,
1951                                      struct nfs_fh *mntfh,
1952                                      const char *dev_name)
1953 {
1954         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1955         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1956         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1957
1958         if (data == NULL)
1959                 goto out_no_data;
1960
1961         args->version = NFS_DEFAULT_VERSION;
1962         switch (data->version) {
1963         case 1:
1964                 data->namlen = 0;
1965         case 2:
1966                 data->bsize = 0;
1967         case 3:
1968                 if (data->flags & NFS_MOUNT_VER3)
1969                         goto out_no_v3;
1970                 data->root.size = NFS2_FHSIZE;
1971                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1972                 /* Turn off security negotiation */
1973                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
1974         case 4:
1975                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1976                         goto out_no_sec;
1977         case 5:
1978                 memset(data->context, 0, sizeof(data->context));
1979         case 6:
1980                 if (data->flags & NFS_MOUNT_VER3) {
1981                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1982                                 goto out_invalid_fh;
1983                         mntfh->size = data->root.size;
1984                         args->version = 3;
1985                 } else {
1986                         mntfh->size = NFS2_FHSIZE;
1987                         args->version = 2;
1988                 }
1989
1990
1991                 memcpy(mntfh->data, data->root.data, mntfh->size);
1992                 if (mntfh->size < sizeof(mntfh->data))
1993                         memset(mntfh->data + mntfh->size, 0,
1994                                sizeof(mntfh->data) - mntfh->size);
1995
1996                 /*
1997                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1998                  * can deal with.
1999                  */
2000                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
2001                 args->flags             |= extra_flags;
2002                 args->rsize             = data->rsize;
2003                 args->wsize             = data->wsize;
2004                 args->timeo             = data->timeo;
2005                 args->retrans           = data->retrans;
2006                 args->acregmin          = data->acregmin;
2007                 args->acregmax          = data->acregmax;
2008                 args->acdirmin          = data->acdirmin;
2009                 args->acdirmax          = data->acdirmax;
2010                 args->need_mount        = false;
2011
2012                 memcpy(sap, &data->addr, sizeof(data->addr));
2013                 args->nfs_server.addrlen = sizeof(data->addr);
2014                 args->nfs_server.port = ntohs(data->addr.sin_port);
2015                 if (!nfs_verify_server_address(sap))
2016                         goto out_no_address;
2017
2018                 if (!(data->flags & NFS_MOUNT_TCP))
2019                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2020                 /* N.B. caller will free nfs_server.hostname in all cases */
2021                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2022                 args->namlen            = data->namlen;
2023                 args->bsize             = data->bsize;
2024
2025                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2026                         args->selected_flavor = data->pseudoflavor;
2027                 else
2028                         args->selected_flavor = RPC_AUTH_UNIX;
2029                 if (!args->nfs_server.hostname)
2030                         goto out_nomem;
2031
2032                 if (!(data->flags & NFS_MOUNT_NONLM))
2033                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2034                                          NFS_MOUNT_LOCAL_FCNTL);
2035                 else
2036                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2037                                         NFS_MOUNT_LOCAL_FCNTL);
2038                 /*
2039                  * The legacy version 6 binary mount data from userspace has a
2040                  * field used only to transport selinux information into the
2041                  * the kernel.  To continue to support that functionality we
2042                  * have a touch of selinux knowledge here in the NFS code. The
2043                  * userspace code converted context=blah to just blah so we are
2044                  * converting back to the full string selinux understands.
2045                  */
2046                 if (data->context[0]){
2047 #ifdef CONFIG_SECURITY_SELINUX
2048                         int rc;
2049                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2050                         if (!opts_str)
2051                                 return -ENOMEM;
2052                         strcpy(opts_str, "context=");
2053                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2054                         strcat(opts_str, &data->context[0]);
2055                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2056                         kfree(opts_str);
2057                         if (rc)
2058                                 return rc;
2059 #else
2060                         return -EINVAL;
2061 #endif
2062                 }
2063
2064                 break;
2065         default:
2066                 return NFS_TEXT_DATA;
2067         }
2068
2069 #if !IS_ENABLED(CONFIG_NFS_V3)
2070         if (args->version == 3)
2071                 goto out_v3_not_compiled;
2072 #endif /* !CONFIG_NFS_V3 */
2073
2074         return 0;
2075
2076 out_no_data:
2077         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2078         return -EINVAL;
2079
2080 out_no_v3:
2081         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2082                  data->version);
2083         return -EINVAL;
2084
2085 out_no_sec:
2086         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2087         return -EINVAL;
2088
2089 #if !IS_ENABLED(CONFIG_NFS_V3)
2090 out_v3_not_compiled:
2091         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
2092         return -EPROTONOSUPPORT;
2093 #endif /* !CONFIG_NFS_V3 */
2094
2095 out_nomem:
2096         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2097         return -ENOMEM;
2098
2099 out_no_address:
2100         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2101         return -EINVAL;
2102
2103 out_invalid_fh:
2104         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2105         return -EINVAL;
2106 }
2107
2108 #if IS_ENABLED(CONFIG_NFS_V4)
2109 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2110                                    void *options,
2111                                    struct nfs_parsed_mount_data *args,
2112                                    struct nfs_fh *mntfh,
2113                                    const char *dev_name)
2114 {
2115         if (fs_type == &nfs_fs_type)
2116                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2117         return nfs4_validate_mount_data(options, args, dev_name);
2118 }
2119 #else
2120 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2121                                    void *options,
2122                                    struct nfs_parsed_mount_data *args,
2123                                    struct nfs_fh *mntfh,
2124                                    const char *dev_name)
2125 {
2126         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2127 }
2128 #endif
2129
2130 static int nfs_validate_text_mount_data(void *options,
2131                                         struct nfs_parsed_mount_data *args,
2132                                         const char *dev_name)
2133 {
2134         int port = 0;
2135         int max_namelen = PAGE_SIZE;
2136         int max_pathlen = NFS_MAXPATHLEN;
2137         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2138
2139         if (nfs_parse_mount_options((char *)options, args) == 0)
2140                 return -EINVAL;
2141
2142         if (!nfs_verify_server_address(sap))
2143                 goto out_no_address;
2144
2145         if (args->version == 4) {
2146 #if IS_ENABLED(CONFIG_NFS_V4)
2147                 port = NFS_PORT;
2148                 max_namelen = NFS4_MAXNAMLEN;
2149                 max_pathlen = NFS4_MAXPATHLEN;
2150                 nfs_validate_transport_protocol(args);
2151                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2152                         goto out_invalid_transport_udp;
2153                 nfs4_validate_mount_flags(args);
2154 #else
2155                 goto out_v4_not_compiled;
2156 #endif /* CONFIG_NFS_V4 */
2157         } else
2158                 nfs_set_mount_transport_protocol(args);
2159
2160         nfs_set_port(sap, &args->nfs_server.port, port);
2161
2162         return nfs_parse_devname(dev_name,
2163                                    &args->nfs_server.hostname,
2164                                    max_namelen,
2165                                    &args->nfs_server.export_path,
2166                                    max_pathlen);
2167
2168 #if !IS_ENABLED(CONFIG_NFS_V4)
2169 out_v4_not_compiled:
2170         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2171         return -EPROTONOSUPPORT;
2172 #else
2173 out_invalid_transport_udp:
2174         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2175         return -EINVAL;
2176 #endif /* !CONFIG_NFS_V4 */
2177
2178 out_no_address:
2179         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2180         return -EINVAL;
2181 }
2182
2183 static int
2184 nfs_compare_remount_data(struct nfs_server *nfss,
2185                          struct nfs_parsed_mount_data *data)
2186 {
2187         if (data->flags != nfss->flags ||
2188             data->rsize != nfss->rsize ||
2189             data->wsize != nfss->wsize ||
2190             data->version != nfss->nfs_client->rpc_ops->version ||
2191             data->minorversion != nfss->nfs_client->cl_minorversion ||
2192             data->retrans != nfss->client->cl_timeout->to_retries ||
2193             data->selected_flavor != nfss->client->cl_auth->au_flavor ||
2194             data->acregmin != nfss->acregmin / HZ ||
2195             data->acregmax != nfss->acregmax / HZ ||
2196             data->acdirmin != nfss->acdirmin / HZ ||
2197             data->acdirmax != nfss->acdirmax / HZ ||
2198             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2199             data->nfs_server.port != nfss->port ||
2200             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2201             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2202                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2203                 return -EINVAL;
2204
2205         return 0;
2206 }
2207
2208 int
2209 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2210 {
2211         int error;
2212         struct nfs_server *nfss = sb->s_fs_info;
2213         struct nfs_parsed_mount_data *data;
2214         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2215         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2216         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2217
2218         /*
2219          * Userspace mount programs that send binary options generally send
2220          * them populated with default values. We have no way to know which
2221          * ones were explicitly specified. Fall back to legacy behavior and
2222          * just return success.
2223          */
2224         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2225             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2226                                            options->version <= 6))))
2227                 return 0;
2228
2229         data = kzalloc(sizeof(*data), GFP_KERNEL);
2230         if (data == NULL)
2231                 return -ENOMEM;
2232
2233         /* fill out struct with values from existing mount */
2234         data->flags = nfss->flags;
2235         data->rsize = nfss->rsize;
2236         data->wsize = nfss->wsize;
2237         data->retrans = nfss->client->cl_timeout->to_retries;
2238         data->selected_flavor = nfss->client->cl_auth->au_flavor;
2239         data->auth_info = nfss->auth_info;
2240         data->acregmin = nfss->acregmin / HZ;
2241         data->acregmax = nfss->acregmax / HZ;
2242         data->acdirmin = nfss->acdirmin / HZ;
2243         data->acdirmax = nfss->acdirmax / HZ;
2244         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2245         data->nfs_server.port = nfss->port;
2246         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2247         data->version = nfsvers;
2248         data->minorversion = nfss->nfs_client->cl_minorversion;
2249         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2250                 data->nfs_server.addrlen);
2251
2252         /* overwrite those values with any that were specified */
2253         error = -EINVAL;
2254         if (!nfs_parse_mount_options((char *)options, data))
2255                 goto out;
2256
2257         /*
2258          * noac is a special case. It implies -o sync, but that's not
2259          * necessarily reflected in the mtab options. do_remount_sb
2260          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2261          * remount options, so we have to explicitly reset it.
2262          */
2263         if (data->flags & NFS_MOUNT_NOAC)
2264                 *flags |= MS_SYNCHRONOUS;
2265
2266         /* compare new mount options with old ones */
2267         error = nfs_compare_remount_data(nfss, data);
2268 out:
2269         kfree(data);
2270         return error;
2271 }
2272 EXPORT_SYMBOL_GPL(nfs_remount);
2273
2274 /*
2275  * Initialise the common bits of the superblock
2276  */
2277 inline void nfs_initialise_sb(struct super_block *sb)
2278 {
2279         struct nfs_server *server = NFS_SB(sb);
2280
2281         sb->s_magic = NFS_SUPER_MAGIC;
2282
2283         /* We probably want something more informative here */
2284         snprintf(sb->s_id, sizeof(sb->s_id),
2285                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2286
2287         if (sb->s_blocksize == 0)
2288                 sb->s_blocksize = nfs_block_bits(server->wsize,
2289                                                  &sb->s_blocksize_bits);
2290
2291         sb->s_bdi = &server->backing_dev_info;
2292
2293         nfs_super_set_maxbytes(sb, server->maxfilesize);
2294 }
2295
2296 /*
2297  * Finish setting up an NFS2/3 superblock
2298  */
2299 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2300 {
2301         struct nfs_parsed_mount_data *data = mount_info->parsed;
2302         struct nfs_server *server = NFS_SB(sb);
2303
2304         sb->s_blocksize_bits = 0;
2305         sb->s_blocksize = 0;
2306         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2307         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2308         if (data && data->bsize)
2309                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2310
2311         if (server->nfs_client->rpc_ops->version != 2) {
2312                 /* The VFS shouldn't apply the umask to mode bits. We will do
2313                  * so ourselves when necessary.
2314                  */
2315                 sb->s_flags |= MS_POSIXACL;
2316                 sb->s_time_gran = 1;
2317         }
2318
2319         nfs_initialise_sb(sb);
2320 }
2321 EXPORT_SYMBOL_GPL(nfs_fill_super);
2322
2323 /*
2324  * Finish setting up a cloned NFS2/3/4 superblock
2325  */
2326 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2327 {
2328         const struct super_block *old_sb = mount_info->cloned->sb;
2329         struct nfs_server *server = NFS_SB(sb);
2330
2331         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2332         sb->s_blocksize = old_sb->s_blocksize;
2333         sb->s_maxbytes = old_sb->s_maxbytes;
2334         sb->s_xattr = old_sb->s_xattr;
2335         sb->s_op = old_sb->s_op;
2336         sb->s_time_gran = 1;
2337
2338         if (server->nfs_client->rpc_ops->version != 2) {
2339                 /* The VFS shouldn't apply the umask to mode bits. We will do
2340                  * so ourselves when necessary.
2341                  */
2342                 sb->s_flags |= MS_POSIXACL;
2343         }
2344
2345         nfs_initialise_sb(sb);
2346 }
2347
2348 #define NFS_MOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2349                 | NFS_MOUNT_SECURE \
2350                 | NFS_MOUNT_TCP \
2351                 | NFS_MOUNT_VER3 \
2352                 | NFS_MOUNT_KERBEROS \
2353                 | NFS_MOUNT_NONLM \
2354                 | NFS_MOUNT_BROKEN_SUID \
2355                 | NFS_MOUNT_STRICTLOCK \
2356                 | NFS_MOUNT_UNSHARED \
2357                 | NFS_MOUNT_NORESVPORT \
2358                 | NFS_MOUNT_LEGACY_INTERFACE)
2359
2360 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2361 {
2362         const struct nfs_server *a = s->s_fs_info;
2363         const struct rpc_clnt *clnt_a = a->client;
2364         const struct rpc_clnt *clnt_b = b->client;
2365
2366         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2367                 goto Ebusy;
2368         if (a->nfs_client != b->nfs_client)
2369                 goto Ebusy;
2370         if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2371                 goto Ebusy;
2372         if (a->wsize != b->wsize)
2373                 goto Ebusy;
2374         if (a->rsize != b->rsize)
2375                 goto Ebusy;
2376         if (a->acregmin != b->acregmin)
2377                 goto Ebusy;
2378         if (a->acregmax != b->acregmax)
2379                 goto Ebusy;
2380         if (a->acdirmin != b->acdirmin)
2381                 goto Ebusy;
2382         if (a->acdirmax != b->acdirmax)
2383                 goto Ebusy;
2384         if (b->auth_info.flavor_len > 0 &&
2385            clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2386                 goto Ebusy;
2387         return 1;
2388 Ebusy:
2389         return 0;
2390 }
2391
2392 struct nfs_sb_mountdata {
2393         struct nfs_server *server;
2394         int mntflags;
2395 };
2396
2397 static int nfs_set_super(struct super_block *s, void *data)
2398 {
2399         struct nfs_sb_mountdata *sb_mntdata = data;
2400         struct nfs_server *server = sb_mntdata->server;
2401         int ret;
2402
2403         s->s_flags = sb_mntdata->mntflags;
2404         s->s_fs_info = server;
2405         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2406         ret = set_anon_super(s, server);
2407         if (ret == 0)
2408                 server->s_dev = s->s_dev;
2409         return ret;
2410 }
2411
2412 static int nfs_compare_super_address(struct nfs_server *server1,
2413                                      struct nfs_server *server2)
2414 {
2415         struct sockaddr *sap1, *sap2;
2416
2417         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2418         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2419
2420         if (sap1->sa_family != sap2->sa_family)
2421                 return 0;
2422
2423         switch (sap1->sa_family) {
2424         case AF_INET: {
2425                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2426                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2427                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2428                         return 0;
2429                 if (sin1->sin_port != sin2->sin_port)
2430                         return 0;
2431                 break;
2432         }
2433         case AF_INET6: {
2434                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2435                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2436                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2437                         return 0;
2438                 if (sin1->sin6_port != sin2->sin6_port)
2439                         return 0;
2440                 break;
2441         }
2442         default:
2443                 return 0;
2444         }
2445
2446         return 1;
2447 }
2448
2449 static int nfs_compare_super(struct super_block *sb, void *data)
2450 {
2451         struct nfs_sb_mountdata *sb_mntdata = data;
2452         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2453         int mntflags = sb_mntdata->mntflags;
2454
2455         if (!nfs_compare_super_address(old, server))
2456                 return 0;
2457         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2458         if (old->flags & NFS_MOUNT_UNSHARED)
2459                 return 0;
2460         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2461                 return 0;
2462         return nfs_compare_mount_options(sb, server, mntflags);
2463 }
2464
2465 #ifdef CONFIG_NFS_FSCACHE
2466 static void nfs_get_cache_cookie(struct super_block *sb,
2467                                  struct nfs_parsed_mount_data *parsed,
2468                                  struct nfs_clone_mount *cloned)
2469 {
2470         struct nfs_server *nfss = NFS_SB(sb);
2471         char *uniq = NULL;
2472         int ulen = 0;
2473
2474         nfss->fscache_key = NULL;
2475         nfss->fscache = NULL;
2476
2477         if (parsed) {
2478                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2479                         return;
2480                 if (parsed->fscache_uniq) {
2481                         uniq = parsed->fscache_uniq;
2482                         ulen = strlen(parsed->fscache_uniq);
2483                 }
2484         } else if (cloned) {
2485                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2486                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2487                         return;
2488                 if (mnt_s->fscache_key) {
2489                         uniq = mnt_s->fscache_key->key.uniquifier;
2490                         ulen = mnt_s->fscache_key->key.uniq_len;
2491                 };
2492         } else
2493                 return;
2494
2495         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2496 }
2497 #else
2498 static void nfs_get_cache_cookie(struct super_block *sb,
2499                                  struct nfs_parsed_mount_data *parsed,
2500                                  struct nfs_clone_mount *cloned)
2501 {
2502 }
2503 #endif
2504
2505 static int nfs_bdi_register(struct nfs_server *server)
2506 {
2507         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2508 }
2509
2510 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2511                         struct nfs_mount_info *mount_info)
2512 {
2513         int error;
2514         unsigned long kflags = 0, kflags_out = 0;
2515         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2516                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2517
2518         error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2519                                                 kflags, &kflags_out);
2520         if (error)
2521                 goto err;
2522
2523         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2524                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2525                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2526 err:
2527         return error;
2528 }
2529 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2530
2531 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2532                           struct nfs_mount_info *mount_info)
2533 {
2534         /* clone any lsm security options from the parent to the new sb */
2535         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2536                 return -ESTALE;
2537         return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2538 }
2539 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2540
2541 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2542                                    int flags, const char *dev_name,
2543                                    struct nfs_mount_info *mount_info,
2544                                    struct nfs_subversion *nfs_mod)
2545 {
2546         struct super_block *s;
2547         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2548         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2549         struct nfs_sb_mountdata sb_mntdata = {
2550                 .mntflags = flags,
2551                 .server = server,
2552         };
2553         int error;
2554
2555         if (server->flags & NFS_MOUNT_UNSHARED)
2556                 compare_super = NULL;
2557
2558         /* -o noac implies -o sync */
2559         if (server->flags & NFS_MOUNT_NOAC)
2560                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2561
2562         if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2563                 if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2564                         sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2565
2566         /* Get a superblock - note that we may end up sharing one that already exists */
2567         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2568         if (IS_ERR(s)) {
2569                 mntroot = ERR_CAST(s);
2570                 goto out_err_nosb;
2571         }
2572
2573         if (s->s_fs_info != server) {
2574                 nfs_free_server(server);
2575                 server = NULL;
2576         } else {
2577                 error = nfs_bdi_register(server);
2578                 if (error) {
2579                         mntroot = ERR_PTR(error);
2580                         goto error_splat_bdi;
2581                 }
2582                 server->super = s;
2583         }
2584
2585         if (!s->s_root) {
2586                 /* initial superblock/root creation */
2587                 mount_info->fill_super(s, mount_info);
2588                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2589         }
2590
2591         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2592         if (IS_ERR(mntroot))
2593                 goto error_splat_super;
2594
2595         error = mount_info->set_security(s, mntroot, mount_info);
2596         if (error)
2597                 goto error_splat_root;
2598
2599         s->s_flags |= MS_ACTIVE;
2600
2601 out:
2602         return mntroot;
2603
2604 out_err_nosb:
2605         nfs_free_server(server);
2606         goto out;
2607
2608 error_splat_root:
2609         dput(mntroot);
2610         mntroot = ERR_PTR(error);
2611 error_splat_super:
2612         if (server && !s->s_root)
2613                 bdi_unregister(&server->backing_dev_info);
2614 error_splat_bdi:
2615         deactivate_locked_super(s);
2616         goto out;
2617 }
2618 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2619
2620 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2621         int flags, const char *dev_name, void *raw_data)
2622 {
2623         struct nfs_mount_info mount_info = {
2624                 .fill_super = nfs_fill_super,
2625                 .set_security = nfs_set_sb_security,
2626         };
2627         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2628         struct nfs_subversion *nfs_mod;
2629         int error;
2630
2631         mount_info.parsed = nfs_alloc_parsed_mount_data();
2632         mount_info.mntfh = nfs_alloc_fhandle();
2633         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2634                 goto out;
2635
2636         /* Validate the mount data */
2637         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2638         if (error == NFS_TEXT_DATA)
2639                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2640         if (error < 0) {
2641                 mntroot = ERR_PTR(error);
2642                 goto out;
2643         }
2644
2645         nfs_mod = get_nfs_version(mount_info.parsed->version);
2646         if (IS_ERR(nfs_mod)) {
2647                 mntroot = ERR_CAST(nfs_mod);
2648                 goto out;
2649         }
2650
2651         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2652
2653         put_nfs_version(nfs_mod);
2654 out:
2655         nfs_free_parsed_mount_data(mount_info.parsed);
2656         nfs_free_fhandle(mount_info.mntfh);
2657         return mntroot;
2658 }
2659 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2660
2661 /*
2662  * Ensure that we unregister the bdi before kill_anon_super
2663  * releases the device name
2664  */
2665 void nfs_put_super(struct super_block *s)
2666 {
2667         struct nfs_server *server = NFS_SB(s);
2668
2669         bdi_unregister(&server->backing_dev_info);
2670 }
2671 EXPORT_SYMBOL_GPL(nfs_put_super);
2672
2673 /*
2674  * Destroy an NFS2/3 superblock
2675  */
2676 void nfs_kill_super(struct super_block *s)
2677 {
2678         struct nfs_server *server = NFS_SB(s);
2679
2680         kill_anon_super(s);
2681         nfs_fscache_release_super_cookie(s);
2682         nfs_free_server(server);
2683 }
2684 EXPORT_SYMBOL_GPL(nfs_kill_super);
2685
2686 /*
2687  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2688  */
2689 static struct dentry *
2690 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2691                 const char *dev_name, void *raw_data)
2692 {
2693         struct nfs_clone_mount *data = raw_data;
2694         struct nfs_mount_info mount_info = {
2695                 .fill_super = nfs_clone_super,
2696                 .set_security = nfs_clone_sb_security,
2697                 .cloned = data,
2698         };
2699         struct nfs_server *server;
2700         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2701         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2702
2703         dprintk("--> nfs_xdev_mount()\n");
2704
2705         mount_info.mntfh = mount_info.cloned->fh;
2706
2707         /* create a new volume representation */
2708         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2709
2710         if (IS_ERR(server))
2711                 mntroot = ERR_CAST(server);
2712         else
2713                 mntroot = nfs_fs_mount_common(server, flags,
2714                                 dev_name, &mount_info, nfs_mod);
2715
2716         dprintk("<-- nfs_xdev_mount() = %ld\n",
2717                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2718         return mntroot;
2719 }
2720
2721 #if IS_ENABLED(CONFIG_NFS_V4)
2722
2723 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2724 {
2725         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2726                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2727 }
2728
2729 /*
2730  * Validate NFSv4 mount options
2731  */
2732 static int nfs4_validate_mount_data(void *options,
2733                                     struct nfs_parsed_mount_data *args,
2734                                     const char *dev_name)
2735 {
2736         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2737         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2738         char *c;
2739
2740         if (data == NULL)
2741                 goto out_no_data;
2742
2743         args->version = 4;
2744
2745         switch (data->version) {
2746         case 1:
2747                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2748                         goto out_no_address;
2749                 if (data->host_addrlen == 0)
2750                         goto out_no_address;
2751                 args->nfs_server.addrlen = data->host_addrlen;
2752                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2753                         return -EFAULT;
2754                 if (!nfs_verify_server_address(sap))
2755                         goto out_no_address;
2756                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2757
2758                 if (data->auth_flavourlen) {
2759                         rpc_authflavor_t pseudoflavor;
2760                         if (data->auth_flavourlen > 1)
2761                                 goto out_inval_auth;
2762                         if (copy_from_user(&pseudoflavor,
2763                                            data->auth_flavours,
2764                                            sizeof(pseudoflavor)))
2765                                 return -EFAULT;
2766                         args->selected_flavor = pseudoflavor;
2767                 } else
2768                         args->selected_flavor = RPC_AUTH_UNIX;
2769
2770                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2771                 if (IS_ERR(c))
2772                         return PTR_ERR(c);
2773                 args->nfs_server.hostname = c;
2774
2775                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2776                 if (IS_ERR(c))
2777                         return PTR_ERR(c);
2778                 args->nfs_server.export_path = c;
2779                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2780
2781                 c = strndup_user(data->client_addr.data, 16);
2782                 if (IS_ERR(c))
2783                         return PTR_ERR(c);
2784                 args->client_address = c;
2785
2786                 /*
2787                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2788                  * can deal with.
2789                  */
2790
2791                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2792                 args->rsize     = data->rsize;
2793                 args->wsize     = data->wsize;
2794                 args->timeo     = data->timeo;
2795                 args->retrans   = data->retrans;
2796                 args->acregmin  = data->acregmin;
2797                 args->acregmax  = data->acregmax;
2798                 args->acdirmin  = data->acdirmin;
2799                 args->acdirmax  = data->acdirmax;
2800                 args->nfs_server.protocol = data->proto;
2801                 nfs_validate_transport_protocol(args);
2802                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2803                         goto out_invalid_transport_udp;
2804
2805                 break;
2806         default:
2807                 return NFS_TEXT_DATA;
2808         }
2809
2810         return 0;
2811
2812 out_no_data:
2813         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2814         return -EINVAL;
2815
2816 out_inval_auth:
2817         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2818                  data->auth_flavourlen);
2819         return -EINVAL;
2820
2821 out_no_address:
2822         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2823         return -EINVAL;
2824
2825 out_invalid_transport_udp:
2826         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2827         return -EINVAL;
2828 }
2829
2830 /*
2831  * NFS v4 module parameters need to stay in the
2832  * NFS client for backwards compatibility
2833  */
2834 unsigned int nfs_callback_set_tcpport;
2835 unsigned short nfs_callback_tcpport;
2836 /* Default cache timeout is 10 minutes */
2837 unsigned int nfs_idmap_cache_timeout = 600;
2838 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2839 bool nfs4_disable_idmapping = true;
2840 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2841 unsigned short send_implementation_id = 1;
2842 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2843 bool recover_lost_locks = false;
2844
2845 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2846 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2847 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2848 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2849 EXPORT_SYMBOL_GPL(max_session_slots);
2850 EXPORT_SYMBOL_GPL(send_implementation_id);
2851 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2852 EXPORT_SYMBOL_GPL(recover_lost_locks);
2853
2854 #define NFS_CALLBACK_MAXPORTNR (65535U)
2855
2856 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2857 {
2858         unsigned long num;
2859         int ret;
2860
2861         if (!val)
2862                 return -EINVAL;
2863         ret = kstrtoul(val, 0, &num);
2864         if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2865                 return -EINVAL;
2866         *((unsigned int *)kp->arg) = num;
2867         return 0;
2868 }
2869 static struct kernel_param_ops param_ops_portnr = {
2870         .set = param_set_portnr,
2871         .get = param_get_uint,
2872 };
2873 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2874
2875 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2876 module_param(nfs_idmap_cache_timeout, int, 0644);
2877 module_param(nfs4_disable_idmapping, bool, 0644);
2878 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2879                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2880 MODULE_PARM_DESC(nfs4_disable_idmapping,
2881                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2882 module_param(max_session_slots, ushort, 0644);
2883 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2884                 "requests the client will negotiate");
2885 module_param(send_implementation_id, ushort, 0644);
2886 MODULE_PARM_DESC(send_implementation_id,
2887                 "Send implementation ID with NFSv4.1 exchange_id");
2888 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2889
2890 module_param(recover_lost_locks, bool, 0644);
2891 MODULE_PARM_DESC(recover_lost_locks,
2892                  "If the server reports that a lock might be lost, "
2893                  "try to recover it risking data corruption.");
2894
2895
2896 #endif /* CONFIG_NFS_V4 */