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