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