fs/nfs/super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/fs/nfs/super.c
   4  *
   5  *  Copyright (C) 1992  Rick Sladkey
   6  *
   7  *  nfs superblock handling functions
   8  *
   9  *  Modularised by Alan Cox <[email protected]>, while hacking some
  10  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  11  *
  12  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  13  *  [email protected]
  14  *
  15  *  Split from inode.c by David Howells <[email protected]>
  16  *
  17  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  18  *   particular server are held in the same superblock
  19  * - NFS superblocks can have several effective roots to the dentry tree
  20  * - directory type roots are spliced into the tree when a path from one root reaches the root
  21  *   of another (see nfs_lookup())
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26
  27 #include <linux/time.h>
  28 #include <linux/kernel.h>
  29 #include <linux/mm.h>
  30 #include <linux/string.h>
  31 #include <linux/stat.h>
  32 #include <linux/errno.h>
  33 #include <linux/unistd.h>
  34 #include <linux/sunrpc/clnt.h>
  35 #include <linux/sunrpc/addr.h>
  36 #include <linux/sunrpc/stats.h>
  37 #include <linux/sunrpc/metrics.h>
  38 #include <linux/sunrpc/xprtsock.h>
  39 #include <linux/sunrpc/xprtrdma.h>
  40 #include <linux/nfs_fs.h>
  41 #include <linux/nfs_mount.h>
  42 #include <linux/nfs4_mount.h>
  43 #include <linux/lockd/bind.h>
  44 #include <linux/seq_file.h>
  45 #include <linux/mount.h>
  46 #include <linux/namei.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 <linux/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 #define NFS_MAX_CONNECTIONS 16
  81
  82 enum {
  83         /* Mount options that take no arguments */
  84         Opt_soft, Opt_softerr, Opt_hard,
  85         Opt_posix, Opt_noposix,
  86         Opt_cto, Opt_nocto,
  87         Opt_ac, Opt_noac,
  88         Opt_lock, Opt_nolock,
  89         Opt_udp, Opt_tcp, Opt_rdma,
  90         Opt_acl, Opt_noacl,
  91         Opt_rdirplus, Opt_nordirplus,
  92         Opt_sharecache, Opt_nosharecache,
  93         Opt_resvport, Opt_noresvport,
  94         Opt_fscache, Opt_nofscache,
  95         Opt_migration, Opt_nomigration,
  96
  97         /* Mount options that take integer arguments */
  98         Opt_port,
  99         Opt_rsize, Opt_wsize, Opt_bsize,
 100         Opt_timeo, Opt_retrans,
 101         Opt_acregmin, Opt_acregmax,
 102         Opt_acdirmin, Opt_acdirmax,
 103         Opt_actimeo,
 104         Opt_namelen,
 105         Opt_mountport,
 106         Opt_mountvers,
 107         Opt_minorversion,
 108
 109         /* Mount options that take string arguments */
 110         Opt_nfsvers,
 111         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 112         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 113         Opt_nconnect,
 114         Opt_lookupcache,
 115         Opt_fscache_uniq,
 116         Opt_local_lock,
 117
 118         /* Special mount options */
 119         Opt_userspace, Opt_deprecated, Opt_sloppy,
 120
 121         Opt_err
 122 };
 123
 124 static const match_table_t nfs_mount_option_tokens = {
 125         { Opt_userspace, "bg" },
 126         { Opt_userspace, "fg" },
 127         { Opt_userspace, "retry=%s" },
 128
 129         { Opt_sloppy, "sloppy" },
 130
 131         { Opt_soft, "soft" },
 132         { Opt_softerr, "softerr" },
 133         { Opt_hard, "hard" },
 134         { Opt_deprecated, "intr" },
 135         { Opt_deprecated, "nointr" },
 136         { Opt_posix, "posix" },
 137         { Opt_noposix, "noposix" },
 138         { Opt_cto, "cto" },
 139         { Opt_nocto, "nocto" },
 140         { Opt_ac, "ac" },
 141         { Opt_noac, "noac" },
 142         { Opt_lock, "lock" },
 143         { Opt_nolock, "nolock" },
 144         { Opt_udp, "udp" },
 145         { Opt_tcp, "tcp" },
 146         { Opt_rdma, "rdma" },
 147         { Opt_acl, "acl" },
 148         { Opt_noacl, "noacl" },
 149         { Opt_rdirplus, "rdirplus" },
 150         { Opt_nordirplus, "nordirplus" },
 151         { Opt_sharecache, "sharecache" },
 152         { Opt_nosharecache, "nosharecache" },
 153         { Opt_resvport, "resvport" },
 154         { Opt_noresvport, "noresvport" },
 155         { Opt_fscache, "fsc" },
 156         { Opt_nofscache, "nofsc" },
 157         { Opt_migration, "migration" },
 158         { Opt_nomigration, "nomigration" },
 159
 160         { Opt_port, "port=%s" },
 161         { Opt_rsize, "rsize=%s" },
 162         { Opt_wsize, "wsize=%s" },
 163         { Opt_bsize, "bsize=%s" },
 164         { Opt_timeo, "timeo=%s" },
 165         { Opt_retrans, "retrans=%s" },
 166         { Opt_acregmin, "acregmin=%s" },
 167         { Opt_acregmax, "acregmax=%s" },
 168         { Opt_acdirmin, "acdirmin=%s" },
 169         { Opt_acdirmax, "acdirmax=%s" },
 170         { Opt_actimeo, "actimeo=%s" },
 171         { Opt_namelen, "namlen=%s" },
 172         { Opt_mountport, "mountport=%s" },
 173         { Opt_mountvers, "mountvers=%s" },
 174         { Opt_minorversion, "minorversion=%s" },
 175
 176         { Opt_nfsvers, "nfsvers=%s" },
 177         { Opt_nfsvers, "vers=%s" },
 178
 179         { Opt_sec, "sec=%s" },
 180         { Opt_proto, "proto=%s" },
 181         { Opt_mountproto, "mountproto=%s" },
 182         { Opt_addr, "addr=%s" },
 183         { Opt_clientaddr, "clientaddr=%s" },
 184         { Opt_mounthost, "mounthost=%s" },
 185         { Opt_mountaddr, "mountaddr=%s" },
 186
 187         { Opt_nconnect, "nconnect=%s" },
 188
 189         { Opt_lookupcache, "lookupcache=%s" },
 190         { Opt_fscache_uniq, "fsc=%s" },
 191         { Opt_local_lock, "local_lock=%s" },
 192
 193         /* The following needs to be listed after all other options */
 194         { Opt_nfsvers, "v%s" },
 195
 196         { Opt_err, NULL }
 197 };
 198
 199 enum {
 200         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 201         Opt_xprt_rdma6,
 202
 203         Opt_xprt_err
 204 };
 205
 206 static const match_table_t nfs_xprt_protocol_tokens = {
 207         { Opt_xprt_udp, "udp" },
 208         { Opt_xprt_udp6, "udp6" },
 209         { Opt_xprt_tcp, "tcp" },
 210         { Opt_xprt_tcp6, "tcp6" },
 211         { Opt_xprt_rdma, "rdma" },
 212         { Opt_xprt_rdma6, "rdma6" },
 213
 214         { Opt_xprt_err, NULL }
 215 };
 216
 217 enum {
 218         Opt_sec_none, Opt_sec_sys,
 219         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 220         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 221         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 222
 223         Opt_sec_err
 224 };
 225
 226 static const match_table_t nfs_secflavor_tokens = {
 227         { Opt_sec_none, "none" },
 228         { Opt_sec_none, "null" },
 229         { Opt_sec_sys, "sys" },
 230
 231         { Opt_sec_krb5, "krb5" },
 232         { Opt_sec_krb5i, "krb5i" },
 233         { Opt_sec_krb5p, "krb5p" },
 234
 235         { Opt_sec_lkey, "lkey" },
 236         { Opt_sec_lkeyi, "lkeyi" },
 237         { Opt_sec_lkeyp, "lkeyp" },
 238
 239         { Opt_sec_spkm, "spkm3" },
 240         { Opt_sec_spkmi, "spkm3i" },
 241         { Opt_sec_spkmp, "spkm3p" },
 242
 243         { Opt_sec_err, NULL }
 244 };
 245
 246 enum {
 247         Opt_lookupcache_all, Opt_lookupcache_positive,
 248         Opt_lookupcache_none,
 249
 250         Opt_lookupcache_err
 251 };
 252
 253 static match_table_t nfs_lookupcache_tokens = {
 254         { Opt_lookupcache_all, "all" },
 255         { Opt_lookupcache_positive, "pos" },
 256         { Opt_lookupcache_positive, "positive" },
 257         { Opt_lookupcache_none, "none" },
 258
 259         { Opt_lookupcache_err, NULL }
 260 };
 261
 262 enum {
 263         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 264         Opt_local_lock_none,
 265
 266         Opt_local_lock_err
 267 };
 268
 269 static match_table_t nfs_local_lock_tokens = {
 270         { Opt_local_lock_all, "all" },
 271         { Opt_local_lock_flock, "flock" },
 272         { Opt_local_lock_posix, "posix" },
 273         { Opt_local_lock_none, "none" },
 274
 275         { Opt_local_lock_err, NULL }
 276 };
 277
 278 enum {
 279         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 280         Opt_vers_4_1, Opt_vers_4_2,
 281
 282         Opt_vers_err
 283 };
 284
 285 static match_table_t nfs_vers_tokens = {
 286         { Opt_vers_2, "2" },
 287         { Opt_vers_3, "3" },
 288         { Opt_vers_4, "4" },
 289         { Opt_vers_4_0, "4.0" },
 290         { Opt_vers_4_1, "4.1" },
 291         { Opt_vers_4_2, "4.2" },
 292
 293         { Opt_vers_err, NULL }
 294 };
 295
 296 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 297                 int flags, const char *dev_name, void *raw_data);
 298
 299 struct file_system_type nfs_fs_type = {
 300         .owner          = THIS_MODULE,
 301         .name           = "nfs",
 302         .mount          = nfs_fs_mount,
 303         .kill_sb        = nfs_kill_super,
 304         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 305 };
 306 MODULE_ALIAS_FS("nfs");
 307 EXPORT_SYMBOL_GPL(nfs_fs_type);
 308
 309 struct file_system_type nfs_xdev_fs_type = {
 310         .owner          = THIS_MODULE,
 311         .name           = "nfs",
 312         .mount          = nfs_xdev_mount,
 313         .kill_sb        = nfs_kill_super,
 314         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 315 };
 316
 317 const struct super_operations nfs_sops = {
 318         .alloc_inode    = nfs_alloc_inode,
 319         .free_inode     = nfs_free_inode,
 320         .write_inode    = nfs_write_inode,
 321         .drop_inode     = nfs_drop_inode,
 322         .statfs         = nfs_statfs,
 323         .evict_inode    = nfs_evict_inode,
 324         .umount_begin   = nfs_umount_begin,
 325         .show_options   = nfs_show_options,
 326         .show_devname   = nfs_show_devname,
 327         .show_path      = nfs_show_path,
 328         .show_stats     = nfs_show_stats,
 329         .remount_fs     = nfs_remount,
 330 };
 331 EXPORT_SYMBOL_GPL(nfs_sops);
 332
 333 #if IS_ENABLED(CONFIG_NFS_V4)
 334 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
 335 static int nfs4_validate_mount_data(void *options,
 336         struct nfs_parsed_mount_data *args, const char *dev_name);
 337
 338 struct file_system_type nfs4_fs_type = {
 339         .owner          = THIS_MODULE,
 340         .name           = "nfs4",
 341         .mount          = nfs_fs_mount,
 342         .kill_sb        = nfs_kill_super,
 343         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 344 };
 345 MODULE_ALIAS_FS("nfs4");
 346 MODULE_ALIAS("nfs4");
 347 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 348
 349 static int __init register_nfs4_fs(void)
 350 {
 351         return register_filesystem(&nfs4_fs_type);
 352 }
 353
 354 static void unregister_nfs4_fs(void)
 355 {
 356         unregister_filesystem(&nfs4_fs_type);
 357 }
 358 #else
 359 static int __init register_nfs4_fs(void)
 360 {
 361         return 0;
 362 }
 363
 364 static void unregister_nfs4_fs(void)
 365 {
 366 }
 367 #endif
 368
 369 static struct shrinker acl_shrinker = {
 370         .count_objects  = nfs_access_cache_count,
 371         .scan_objects   = nfs_access_cache_scan,
 372         .seeks          = DEFAULT_SEEKS,
 373 };
 374
 375 /*
 376  * Register the NFS filesystems
 377  */
 378 int __init register_nfs_fs(void)
 379 {
 380         int ret;
 381
 382         ret = register_filesystem(&nfs_fs_type);
 383         if (ret < 0)
 384                 goto error_0;
 385
 386         ret = register_nfs4_fs();
 387         if (ret < 0)
 388                 goto error_1;
 389
 390         ret = nfs_register_sysctl();
 391         if (ret < 0)
 392                 goto error_2;
 393         ret = register_shrinker(&acl_shrinker);
 394         if (ret < 0)
 395                 goto error_3;
 396         return 0;
 397 error_3:
 398         nfs_unregister_sysctl();
 399 error_2:
 400         unregister_nfs4_fs();
 401 error_1:
 402         unregister_filesystem(&nfs_fs_type);
 403 error_0:
 404         return ret;
 405 }
 406
 407 /*
 408  * Unregister the NFS filesystems
 409  */
 410 void __exit unregister_nfs_fs(void)
 411 {
 412         unregister_shrinker(&acl_shrinker);
 413         nfs_unregister_sysctl();
 414         unregister_nfs4_fs();
 415         unregister_filesystem(&nfs_fs_type);
 416 }
 417
 418 bool nfs_sb_active(struct super_block *sb)
 419 {
 420         struct nfs_server *server = NFS_SB(sb);
 421
 422         if (!atomic_inc_not_zero(&sb->s_active))
 423                 return false;
 424         if (atomic_inc_return(&server->active) != 1)
 425                 atomic_dec(&sb->s_active);
 426         return true;
 427 }
 428 EXPORT_SYMBOL_GPL(nfs_sb_active);
 429
 430 void nfs_sb_deactive(struct super_block *sb)
 431 {
 432         struct nfs_server *server = NFS_SB(sb);
 433
 434         if (atomic_dec_and_test(&server->active))
 435                 deactivate_super(sb);
 436 }
 437 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
 438
 439 /*
 440  * Deliver file system statistics to userspace
 441  */
 442 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 443 {
 444         struct nfs_server *server = NFS_SB(dentry->d_sb);
 445         unsigned char blockbits;
 446         unsigned long blockres;
 447         struct nfs_fh *fh = NFS_FH(d_inode(dentry));
 448         struct nfs_fsstat res;
 449         int error = -ENOMEM;
 450
 451         res.fattr = nfs_alloc_fattr();
 452         if (res.fattr == NULL)
 453                 goto out_err;
 454
 455         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 456         if (unlikely(error == -ESTALE)) {
 457                 struct dentry *pd_dentry;
 458
 459                 pd_dentry = dget_parent(dentry);
 460                 nfs_zap_caches(d_inode(pd_dentry));
 461                 dput(pd_dentry);
 462         }
 463         nfs_free_fattr(res.fattr);
 464         if (error < 0)
 465                 goto out_err;
 466
 467         buf->f_type = NFS_SUPER_MAGIC;
 468
 469         /*
 470          * Current versions of glibc do not correctly handle the
 471          * case where f_frsize != f_bsize.  Eventually we want to
 472          * report the value of wtmult in this field.
 473          */
 474         buf->f_frsize = dentry->d_sb->s_blocksize;
 475
 476         /*
 477          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 478          * are reported in units of f_frsize.  Linux hasn't had
 479          * an f_frsize field in its statfs struct until recently,
 480          * thus historically Linux's sys_statfs reports these
 481          * fields in units of f_bsize.
 482          */
 483         buf->f_bsize = dentry->d_sb->s_blocksize;
 484         blockbits = dentry->d_sb->s_blocksize_bits;
 485         blockres = (1 << blockbits) - 1;
 486         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 487         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 488         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 489
 490         buf->f_files = res.tfiles;
 491         buf->f_ffree = res.afiles;
 492
 493         buf->f_namelen = server->namelen;
 494
 495         return 0;
 496
 497  out_err:
 498         dprintk("%s: statfs error = %d\n", __func__, -error);
 499         return error;
 500 }
 501 EXPORT_SYMBOL_GPL(nfs_statfs);
 502
 503 /*
 504  * Map the security flavour number to a name
 505  */
 506 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 507 {
 508         static const struct {
 509                 rpc_authflavor_t flavour;
 510                 const char *str;
 511         } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
 512                 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
 513                 { RPC_AUTH_NULL, "null" },
 514                 { RPC_AUTH_UNIX, "sys" },
 515                 { RPC_AUTH_GSS_KRB5, "krb5" },
 516                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 517                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 518                 { RPC_AUTH_GSS_LKEY, "lkey" },
 519                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 520                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 521                 { RPC_AUTH_GSS_SPKM, "spkm" },
 522                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 523                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 524                 { UINT_MAX, "unknown" }
 525         };
 526         int i;
 527
 528         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 529                 if (sec_flavours[i].flavour == flavour)
 530                         break;
 531         }
 532         return sec_flavours[i].str;
 533 }
 534
 535 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 536                                   int showdefaults)
 537 {
 538         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 539         char *proto = NULL;
 540
 541         switch (sap->sa_family) {
 542         case AF_INET:
 543                 switch (nfss->mountd_protocol) {
 544                 case IPPROTO_UDP:
 545                         proto = RPCBIND_NETID_UDP;
 546                         break;
 547                 case IPPROTO_TCP:
 548                         proto = RPCBIND_NETID_TCP;
 549                         break;
 550                 }
 551                 break;
 552         case AF_INET6:
 553                 switch (nfss->mountd_protocol) {
 554                 case IPPROTO_UDP:
 555                         proto = RPCBIND_NETID_UDP6;
 556                         break;
 557                 case IPPROTO_TCP:
 558                         proto = RPCBIND_NETID_TCP6;
 559                         break;
 560                 }
 561                 break;
 562         }
 563         if (proto || showdefaults)
 564                 seq_printf(m, ",mountproto=%s", proto ?: "auto");
 565 }
 566
 567 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 568                                     int showdefaults)
 569 {
 570         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 571
 572         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 573                 return;
 574
 575         switch (sap->sa_family) {
 576         case AF_INET: {
 577                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 578                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 579                 break;
 580         }
 581         case AF_INET6: {
 582                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 583                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 584                 break;
 585         }
 586         default:
 587                 if (showdefaults)
 588                         seq_puts(m, ",mountaddr=unspecified");
 589         }
 590
 591         if (nfss->mountd_version || showdefaults)
 592                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 593         if ((nfss->mountd_port &&
 594                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 595                 showdefaults)
 596                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 597
 598         nfs_show_mountd_netid(m, nfss, showdefaults);
 599 }
 600
 601 #if IS_ENABLED(CONFIG_NFS_V4)
 602 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 603                                     int showdefaults)
 604 {
 605         struct nfs_client *clp = nfss->nfs_client;
 606
 607         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 608 }
 609 #else
 610 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 611                                     int showdefaults)
 612 {
 613 }
 614 #endif
 615
 616 static void nfs_show_nfs_version(struct seq_file *m,
 617                 unsigned int version,
 618                 unsigned int minorversion)
 619 {
 620         seq_printf(m, ",vers=%u", version);
 621         if (version == 4)
 622                 seq_printf(m, ".%u", minorversion);
 623 }
 624
 625 /*
 626  * Describe the mount options in force on this server representation
 627  */
 628 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 629                                    int showdefaults)
 630 {
 631         static const struct proc_nfs_info {
 632                 int flag;
 633                 const char *str;
 634                 const char *nostr;
 635         } nfs_info[] = {
 636                 { NFS_MOUNT_SOFT, ",soft", "" },
 637                 { NFS_MOUNT_SOFTERR, ",softerr", "" },
 638                 { NFS_MOUNT_POSIX, ",posix", "" },
 639                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 640                 { NFS_MOUNT_NOAC, ",noac", "" },
 641                 { NFS_MOUNT_NONLM, ",nolock", "" },
 642                 { NFS_MOUNT_NOACL, ",noacl", "" },
 643                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 644                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 645                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 646                 { 0, NULL, NULL }
 647         };
 648         const struct proc_nfs_info *nfs_infop;
 649         struct nfs_client *clp = nfss->nfs_client;
 650         u32 version = clp->rpc_ops->version;
 651         int local_flock, local_fcntl;
 652
 653         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 654         seq_printf(m, ",rsize=%u", nfss->rsize);
 655         seq_printf(m, ",wsize=%u", nfss->wsize);
 656         if (nfss->bsize != 0)
 657                 seq_printf(m, ",bsize=%u", nfss->bsize);
 658         seq_printf(m, ",namlen=%u", nfss->namelen);
 659         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 660                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 661         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 662                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 663         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 664                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 665         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 666                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 667         if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
 668                         seq_puts(m, ",hard");
 669         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 670                 if (nfss->flags & nfs_infop->flag)
 671                         seq_puts(m, nfs_infop->str);
 672                 else
 673                         seq_puts(m, nfs_infop->nostr);
 674         }
 675         rcu_read_lock();
 676         seq_printf(m, ",proto=%s",
 677                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 678         rcu_read_unlock();
 679         if (clp->cl_nconnect > 0)
 680                 seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
 681         if (version == 4) {
 682                 if (nfss->port != NFS_PORT)
 683                         seq_printf(m, ",port=%u", nfss->port);
 684         } else
 685                 if (nfss->port)
 686                         seq_printf(m, ",port=%u", nfss->port);
 687
 688         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 689         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 690         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 691
 692         if (version != 4)
 693                 nfs_show_mountd_options(m, nfss, showdefaults);
 694         else
 695                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 696
 697         if (nfss->options & NFS_OPTION_FSCACHE)
 698                 seq_puts(m, ",fsc");
 699
 700         if (nfss->options & NFS_OPTION_MIGRATION)
 701                 seq_puts(m, ",migration");
 702
 703         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 704                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 705                         seq_puts(m, ",lookupcache=none");
 706                 else
 707                         seq_puts(m, ",lookupcache=pos");
 708         }
 709
 710         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 711         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 712
 713         if (!local_flock && !local_fcntl)
 714                 seq_puts(m, ",local_lock=none");
 715         else if (local_flock && local_fcntl)
 716                 seq_puts(m, ",local_lock=all");
 717         else if (local_flock)
 718                 seq_puts(m, ",local_lock=flock");
 719         else
 720                 seq_puts(m, ",local_lock=posix");
 721 }
 722
 723 /*
 724  * Describe the mount options on this VFS mountpoint
 725  */
 726 int nfs_show_options(struct seq_file *m, struct dentry *root)
 727 {
 728         struct nfs_server *nfss = NFS_SB(root->d_sb);
 729
 730         nfs_show_mount_options(m, nfss, 0);
 731
 732         rcu_read_lock();
 733         seq_printf(m, ",addr=%s",
 734                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 735                                                         RPC_DISPLAY_ADDR));
 736         rcu_read_unlock();
 737
 738         return 0;
 739 }
 740 EXPORT_SYMBOL_GPL(nfs_show_options);
 741
 742 #if IS_ENABLED(CONFIG_NFS_V4)
 743 static void show_lease(struct seq_file *m, struct nfs_server *server)
 744 {
 745         struct nfs_client *clp = server->nfs_client;
 746         unsigned long expire;
 747
 748         seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
 749         expire = clp->cl_last_renewal + clp->cl_lease_time;
 750         seq_printf(m, ",lease_expired=%ld",
 751                    time_after(expire, jiffies) ?  0 : (jiffies - expire) / HZ);
 752 }
 753 #ifdef CONFIG_NFS_V4_1
 754 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 755 {
 756         if (nfs4_has_session(server->nfs_client))
 757                 seq_puts(m, ",sessions");
 758 }
 759 #else
 760 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 761 #endif
 762 #endif
 763
 764 #ifdef CONFIG_NFS_V4_1
 765 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 766 {
 767         seq_printf(m, ",pnfs=");
 768         if (server->pnfs_curr_ld)
 769                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 770         else
 771                 seq_printf(m, "not configured");
 772 }
 773
 774 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 775 {
 776         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 777                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 778                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 779                            "date='%llu,%u'",
 780                            impl_id->name, impl_id->domain,
 781                            impl_id->date.seconds, impl_id->date.nseconds);
 782         }
 783 }
 784 #else
 785 #if IS_ENABLED(CONFIG_NFS_V4)
 786 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 787 {
 788 }
 789 #endif
 790 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 791 {
 792 }
 793 #endif
 794
 795 int nfs_show_devname(struct seq_file *m, struct dentry *root)
 796 {
 797         char *page = (char *) __get_free_page(GFP_KERNEL);
 798         char *devname, *dummy;
 799         int err = 0;
 800         if (!page)
 801                 return -ENOMEM;
 802         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
 803         if (IS_ERR(devname))
 804                 err = PTR_ERR(devname);
 805         else
 806                 seq_escape(m, devname, " \t\n\\");
 807         free_page((unsigned long)page);
 808         return err;
 809 }
 810 EXPORT_SYMBOL_GPL(nfs_show_devname);
 811
 812 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 813 {
 814         seq_puts(m, "/");
 815         return 0;
 816 }
 817 EXPORT_SYMBOL_GPL(nfs_show_path);
 818
 819 /*
 820  * Present statistical information for this VFS mountpoint
 821  */
 822 int nfs_show_stats(struct seq_file *m, struct dentry *root)
 823 {
 824         int i, cpu;
 825         struct nfs_server *nfss = NFS_SB(root->d_sb);
 826         struct rpc_auth *auth = nfss->client->cl_auth;
 827         struct nfs_iostats totals = { };
 828
 829         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 830
 831         /*
 832          * Display all mount option settings
 833          */
 834         seq_puts(m, "\n\topts:\t");
 835         seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
 836         seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
 837         seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
 838         seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
 839         nfs_show_mount_options(m, nfss, 1);
 840
 841         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 842
 843         show_implementation_id(m, nfss);
 844
 845         seq_puts(m, "\n\tcaps:\t");
 846         seq_printf(m, "caps=0x%x", nfss->caps);
 847         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 848         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 849         seq_printf(m, ",bsize=%u", nfss->bsize);
 850         seq_printf(m, ",namlen=%u", nfss->namelen);
 851
 852 #if IS_ENABLED(CONFIG_NFS_V4)
 853         if (nfss->nfs_client->rpc_ops->version == 4) {
 854                 seq_puts(m, "\n\tnfsv4:\t");
 855                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 856                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 857                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
 858                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 859                 show_sessions(m, nfss);
 860                 show_pnfs(m, nfss);
 861                 show_lease(m, nfss);
 862         }
 863 #endif
 864
 865         /*
 866          * Display security flavor in effect for this mount
 867          */
 868         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 869         if (auth->au_flavor)
 870                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 871
 872         /*
 873          * Display superblock I/O counters
 874          */
 875         for_each_possible_cpu(cpu) {
 876                 struct nfs_iostats *stats;
 877
 878                 preempt_disable();
 879                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 880
 881                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 882                         totals.events[i] += stats->events[i];
 883                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 884                         totals.bytes[i] += stats->bytes[i];
 885 #ifdef CONFIG_NFS_FSCACHE
 886                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 887                         totals.fscache[i] += stats->fscache[i];
 888 #endif
 889
 890                 preempt_enable();
 891         }
 892
 893         seq_puts(m, "\n\tevents:\t");
 894         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 895                 seq_printf(m, "%lu ", totals.events[i]);
 896         seq_puts(m, "\n\tbytes:\t");
 897         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 898                 seq_printf(m, "%Lu ", totals.bytes[i]);
 899 #ifdef CONFIG_NFS_FSCACHE
 900         if (nfss->options & NFS_OPTION_FSCACHE) {
 901                 seq_puts(m, "\n\tfsc:\t");
 902                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 903                         seq_printf(m, "%Lu ", totals.fscache[i]);
 904         }
 905 #endif
 906         seq_putc(m, '\n');
 907
 908         rpc_clnt_show_stats(m, nfss->client);
 909
 910         return 0;
 911 }
 912 EXPORT_SYMBOL_GPL(nfs_show_stats);
 913
 914 /*
 915  * Begin unmount by attempting to remove all automounted mountpoints we added
 916  * in response to xdev traversals and referrals
 917  */
 918 void nfs_umount_begin(struct super_block *sb)
 919 {
 920         struct nfs_server *server;
 921         struct rpc_clnt *rpc;
 922
 923         server = NFS_SB(sb);
 924         /* -EIO all pending I/O */
 925         rpc = server->client_acl;
 926         if (!IS_ERR(rpc))
 927                 rpc_killall_tasks(rpc);
 928         rpc = server->client;
 929         if (!IS_ERR(rpc))
 930                 rpc_killall_tasks(rpc);
 931 }
 932 EXPORT_SYMBOL_GPL(nfs_umount_begin);
 933
 934 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 935 {
 936         struct nfs_parsed_mount_data *data;
 937
 938         data = kzalloc(sizeof(*data), GFP_KERNEL);
 939         if (data) {
 940                 data->timeo             = NFS_UNSPEC_TIMEO;
 941                 data->retrans           = NFS_UNSPEC_RETRANS;
 942                 data->acregmin          = NFS_DEF_ACREGMIN;
 943                 data->acregmax          = NFS_DEF_ACREGMAX;
 944                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 945                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 946                 data->mount_server.port = NFS_UNSPEC_PORT;
 947                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 948                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 949                 data->selected_flavor   = RPC_AUTH_MAXFLAVOR;
 950                 data->minorversion      = 0;
 951                 data->need_mount        = true;
 952                 data->net               = current->nsproxy->net_ns;
 953                 data->lsm_opts          = NULL;
 954         }
 955         return data;
 956 }
 957
 958 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 959 {
 960         if (data) {
 961                 kfree(data->client_address);
 962                 kfree(data->mount_server.hostname);
 963                 kfree(data->nfs_server.export_path);
 964                 kfree(data->nfs_server.hostname);
 965                 kfree(data->fscache_uniq);
 966                 security_free_mnt_opts(&data->lsm_opts);
 967                 kfree(data);
 968         }
 969 }
 970
 971 /*
 972  * Sanity-check a server address provided by the mount command.
 973  *
 974  * Address family must be initialized, and address must not be
 975  * the ANY address for that family.
 976  */
 977 static int nfs_verify_server_address(struct sockaddr *addr)
 978 {
 979         switch (addr->sa_family) {
 980         case AF_INET: {
 981                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 982                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 983         }
 984         case AF_INET6: {
 985                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 986                 return !ipv6_addr_any(sa);
 987         }
 988         }
 989
 990         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 991         return 0;
 992 }
 993
 994 /*
 995  * Select between a default port value and a user-specified port value.
 996  * If a zero value is set, then autobind will be used.
 997  */
 998 static void nfs_set_port(struct sockaddr *sap, int *port,
 999                                  const unsigned short default_port)
1000 {
1001         if (*port == NFS_UNSPEC_PORT)
1002                 *port = default_port;
1003
1004         rpc_set_port(sap, *port);
1005 }
1006
1007 /*
1008  * Sanity check the NFS transport protocol.
1009  *
1010  */
1011 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1012 {
1013         switch (mnt->nfs_server.protocol) {
1014         case XPRT_TRANSPORT_UDP:
1015         case XPRT_TRANSPORT_TCP:
1016         case XPRT_TRANSPORT_RDMA:
1017                 break;
1018         default:
1019                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1020         }
1021 }
1022
1023 /*
1024  * For text based NFSv2/v3 mounts, the mount protocol transport default
1025  * settings should depend upon the specified NFS transport.
1026  */
1027 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1028 {
1029         nfs_validate_transport_protocol(mnt);
1030
1031         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1032             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1033                         return;
1034         switch (mnt->nfs_server.protocol) {
1035         case XPRT_TRANSPORT_UDP:
1036                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1037                 break;
1038         case XPRT_TRANSPORT_TCP:
1039         case XPRT_TRANSPORT_RDMA:
1040                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1041         }
1042 }
1043
1044 /*
1045  * Add 'flavor' to 'auth_info' if not already present.
1046  * Returns true if 'flavor' ends up in the list, false otherwise
1047  */
1048 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1049                               rpc_authflavor_t flavor)
1050 {
1051         unsigned int i;
1052         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1053
1054         /* make sure this flavor isn't already in the list */
1055         for (i = 0; i < auth_info->flavor_len; i++) {
1056                 if (flavor == auth_info->flavors[i])
1057                         return true;
1058         }
1059
1060         if (auth_info->flavor_len + 1 >= max_flavor_len) {
1061                 dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1062                 return false;
1063         }
1064
1065         auth_info->flavors[auth_info->flavor_len++] = flavor;
1066         return true;
1067 }
1068
1069 /*
1070  * Return true if 'match' is in auth_info or auth_info is empty.
1071  * Return false otherwise.
1072  */
1073 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1074                          rpc_authflavor_t match)
1075 {
1076         int i;
1077
1078         if (!auth_info->flavor_len)
1079                 return true;
1080
1081         for (i = 0; i < auth_info->flavor_len; i++) {
1082                 if (auth_info->flavors[i] == match)
1083                         return true;
1084         }
1085         return false;
1086 }
1087 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1088
1089 /*
1090  * Parse the value of the 'sec=' option.
1091  */
1092 static int nfs_parse_security_flavors(char *value,
1093                                       struct nfs_parsed_mount_data *mnt)
1094 {
1095         substring_t args[MAX_OPT_ARGS];
1096         rpc_authflavor_t pseudoflavor;
1097         char *p;
1098
1099         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1100
1101         while ((p = strsep(&value, ":")) != NULL) {
1102                 switch (match_token(p, nfs_secflavor_tokens, args)) {
1103                 case Opt_sec_none:
1104                         pseudoflavor = RPC_AUTH_NULL;
1105                         break;
1106                 case Opt_sec_sys:
1107                         pseudoflavor = RPC_AUTH_UNIX;
1108                         break;
1109                 case Opt_sec_krb5:
1110                         pseudoflavor = RPC_AUTH_GSS_KRB5;
1111                         break;
1112                 case Opt_sec_krb5i:
1113                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
1114                         break;
1115                 case Opt_sec_krb5p:
1116                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
1117                         break;
1118                 case Opt_sec_lkey:
1119                         pseudoflavor = RPC_AUTH_GSS_LKEY;
1120                         break;
1121                 case Opt_sec_lkeyi:
1122                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
1123                         break;
1124                 case Opt_sec_lkeyp:
1125                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
1126                         break;
1127                 case Opt_sec_spkm:
1128                         pseudoflavor = RPC_AUTH_GSS_SPKM;
1129                         break;
1130                 case Opt_sec_spkmi:
1131                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
1132                         break;
1133                 case Opt_sec_spkmp:
1134                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
1135                         break;
1136                 default:
1137                         dfprintk(MOUNT,
1138                                  "NFS: sec= option '%s' not recognized\n", p);
1139                         return 0;
1140                 }
1141
1142                 if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1143                         return 0;
1144         }
1145
1146         return 1;
1147 }
1148
1149 static int nfs_parse_version_string(char *string,
1150                 struct nfs_parsed_mount_data *mnt,
1151                 substring_t *args)
1152 {
1153         mnt->flags &= ~NFS_MOUNT_VER3;
1154         switch (match_token(string, nfs_vers_tokens, args)) {
1155         case Opt_vers_2:
1156                 mnt->version = 2;
1157                 break;
1158         case Opt_vers_3:
1159                 mnt->flags |= NFS_MOUNT_VER3;
1160                 mnt->version = 3;
1161                 break;
1162         case Opt_vers_4:
1163                 /* Backward compatibility option. In future,
1164                  * the mount program should always supply
1165                  * a NFSv4 minor version number.
1166                  */
1167                 mnt->version = 4;
1168                 break;
1169         case Opt_vers_4_0:
1170                 mnt->version = 4;
1171                 mnt->minorversion = 0;
1172                 break;
1173         case Opt_vers_4_1:
1174                 mnt->version = 4;
1175                 mnt->minorversion = 1;
1176                 break;
1177         case Opt_vers_4_2:
1178                 mnt->version = 4;
1179                 mnt->minorversion = 2;
1180                 break;
1181         default:
1182                 return 0;
1183         }
1184         return 1;
1185 }
1186
1187 static int nfs_get_option_str(substring_t args[], char **option)
1188 {
1189         kfree(*option);
1190         *option = match_strdup(args);
1191         return !*option;
1192 }
1193
1194 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1195 {
1196         int rc;
1197         char *string;
1198
1199         string = match_strdup(args);
1200         if (string == NULL)
1201                 return -ENOMEM;
1202         rc = kstrtoul(string, 10, option);
1203         kfree(string);
1204
1205         return rc;
1206 }
1207
1208 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1209                 unsigned long l_bound, unsigned long u_bound)
1210 {
1211         int ret;
1212
1213         ret = nfs_get_option_ul(args, option);
1214         if (ret != 0)
1215                 return ret;
1216         if (*option < l_bound || *option > u_bound)
1217                 return -ERANGE;
1218         return 0;
1219 }
1220
1221 /*
1222  * Error-check and convert a string of mount options from user space into
1223  * a data structure.  The whole mount string is processed; bad options are
1224  * skipped as they are encountered.  If there were no errors, return 1;
1225  * otherwise return 0 (zero).
1226  */
1227 static int nfs_parse_mount_options(char *raw,
1228                                    struct nfs_parsed_mount_data *mnt)
1229 {
1230         char *p, *string;
1231         int rc, sloppy = 0, invalid_option = 0;
1232         unsigned short protofamily = AF_UNSPEC;
1233         unsigned short mountfamily = AF_UNSPEC;
1234
1235         if (!raw) {
1236                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1237                 return 1;
1238         }
1239         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1240
1241         rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1242         if (rc)
1243                 goto out_security_failure;
1244
1245         while ((p = strsep(&raw, ",")) != NULL) {
1246                 substring_t args[MAX_OPT_ARGS];
1247                 unsigned long option;
1248                 int token;
1249
1250                 if (!*p)
1251                         continue;
1252
1253                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1254
1255                 token = match_token(p, nfs_mount_option_tokens, args);
1256                 switch (token) {
1257
1258                 /*
1259                  * boolean options:  foo/nofoo
1260                  */
1261                 case Opt_soft:
1262                         mnt->flags |= NFS_MOUNT_SOFT;
1263                         mnt->flags &= ~NFS_MOUNT_SOFTERR;
1264                         break;
1265                 case Opt_softerr:
1266                         mnt->flags |= NFS_MOUNT_SOFTERR;
1267                         mnt->flags &= ~NFS_MOUNT_SOFT;
1268                         break;
1269                 case Opt_hard:
1270                         mnt->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
1271                         break;
1272                 case Opt_posix:
1273                         mnt->flags |= NFS_MOUNT_POSIX;
1274                         break;
1275                 case Opt_noposix:
1276                         mnt->flags &= ~NFS_MOUNT_POSIX;
1277                         break;
1278                 case Opt_cto:
1279                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1280                         break;
1281                 case Opt_nocto:
1282                         mnt->flags |= NFS_MOUNT_NOCTO;
1283                         break;
1284                 case Opt_ac:
1285                         mnt->flags &= ~NFS_MOUNT_NOAC;
1286                         break;
1287                 case Opt_noac:
1288                         mnt->flags |= NFS_MOUNT_NOAC;
1289                         break;
1290                 case Opt_lock:
1291                         mnt->flags &= ~NFS_MOUNT_NONLM;
1292                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1293                                         NFS_MOUNT_LOCAL_FCNTL);
1294                         break;
1295                 case Opt_nolock:
1296                         mnt->flags |= NFS_MOUNT_NONLM;
1297                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1298                                        NFS_MOUNT_LOCAL_FCNTL);
1299                         break;
1300                 case Opt_udp:
1301                         mnt->flags &= ~NFS_MOUNT_TCP;
1302                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1303                         break;
1304                 case Opt_tcp:
1305                         mnt->flags |= NFS_MOUNT_TCP;
1306                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1307                         break;
1308                 case Opt_rdma:
1309                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1310                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1311                         xprt_load_transport(p);
1312                         break;
1313                 case Opt_acl:
1314                         mnt->flags &= ~NFS_MOUNT_NOACL;
1315                         break;
1316                 case Opt_noacl:
1317                         mnt->flags |= NFS_MOUNT_NOACL;
1318                         break;
1319                 case Opt_rdirplus:
1320                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1321                         break;
1322                 case Opt_nordirplus:
1323                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1324                         break;
1325                 case Opt_sharecache:
1326                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1327                         break;
1328                 case Opt_nosharecache:
1329                         mnt->flags |= NFS_MOUNT_UNSHARED;
1330                         break;
1331                 case Opt_resvport:
1332                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1333                         break;
1334                 case Opt_noresvport:
1335                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1336                         break;
1337                 case Opt_fscache:
1338                         mnt->options |= NFS_OPTION_FSCACHE;
1339                         kfree(mnt->fscache_uniq);
1340                         mnt->fscache_uniq = NULL;
1341                         break;
1342                 case Opt_nofscache:
1343                         mnt->options &= ~NFS_OPTION_FSCACHE;
1344                         kfree(mnt->fscache_uniq);
1345                         mnt->fscache_uniq = NULL;
1346                         break;
1347                 case Opt_migration:
1348                         mnt->options |= NFS_OPTION_MIGRATION;
1349                         break;
1350                 case Opt_nomigration:
1351                         mnt->options &= ~NFS_OPTION_MIGRATION;
1352                         break;
1353
1354                 /*
1355                  * options that take numeric values
1356                  */
1357                 case Opt_port:
1358                         if (nfs_get_option_ul(args, &option) ||
1359                             option > USHRT_MAX)
1360                                 goto out_invalid_value;
1361                         mnt->nfs_server.port = option;
1362                         break;
1363                 case Opt_rsize:
1364                         if (nfs_get_option_ul(args, &option))
1365                                 goto out_invalid_value;
1366                         mnt->rsize = option;
1367                         break;
1368                 case Opt_wsize:
1369                         if (nfs_get_option_ul(args, &option))
1370                                 goto out_invalid_value;
1371                         mnt->wsize = option;
1372                         break;
1373                 case Opt_bsize:
1374                         if (nfs_get_option_ul(args, &option))
1375                                 goto out_invalid_value;
1376                         mnt->bsize = option;
1377                         break;
1378                 case Opt_timeo:
1379                         if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1380                                 goto out_invalid_value;
1381                         mnt->timeo = option;
1382                         break;
1383                 case Opt_retrans:
1384                         if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1385                                 goto out_invalid_value;
1386                         mnt->retrans = option;
1387                         break;
1388                 case Opt_acregmin:
1389                         if (nfs_get_option_ul(args, &option))
1390                                 goto out_invalid_value;
1391                         mnt->acregmin = option;
1392                         break;
1393                 case Opt_acregmax:
1394                         if (nfs_get_option_ul(args, &option))
1395                                 goto out_invalid_value;
1396                         mnt->acregmax = option;
1397                         break;
1398                 case Opt_acdirmin:
1399                         if (nfs_get_option_ul(args, &option))
1400                                 goto out_invalid_value;
1401                         mnt->acdirmin = option;
1402                         break;
1403                 case Opt_acdirmax:
1404                         if (nfs_get_option_ul(args, &option))
1405                                 goto out_invalid_value;
1406                         mnt->acdirmax = option;
1407                         break;
1408                 case Opt_actimeo:
1409                         if (nfs_get_option_ul(args, &option))
1410                                 goto out_invalid_value;
1411                         mnt->acregmin = mnt->acregmax =
1412                         mnt->acdirmin = mnt->acdirmax = option;
1413                         break;
1414                 case Opt_namelen:
1415                         if (nfs_get_option_ul(args, &option))
1416                                 goto out_invalid_value;
1417                         mnt->namlen = option;
1418                         break;
1419                 case Opt_mountport:
1420                         if (nfs_get_option_ul(args, &option) ||
1421                             option > USHRT_MAX)
1422                                 goto out_invalid_value;
1423                         mnt->mount_server.port = option;
1424                         break;
1425                 case Opt_mountvers:
1426                         if (nfs_get_option_ul(args, &option) ||
1427                             option < NFS_MNT_VERSION ||
1428                             option > NFS_MNT3_VERSION)
1429                                 goto out_invalid_value;
1430                         mnt->mount_server.version = option;
1431                         break;
1432                 case Opt_minorversion:
1433                         if (nfs_get_option_ul(args, &option))
1434                                 goto out_invalid_value;
1435                         if (option > NFS4_MAX_MINOR_VERSION)
1436                                 goto out_invalid_value;
1437                         mnt->minorversion = option;
1438                         break;
1439
1440                 /*
1441                  * options that take text values
1442                  */
1443                 case Opt_nfsvers:
1444                         string = match_strdup(args);
1445                         if (string == NULL)
1446                                 goto out_nomem;
1447                         rc = nfs_parse_version_string(string, mnt, args);
1448                         kfree(string);
1449                         if (!rc)
1450                                 goto out_invalid_value;
1451                         break;
1452                 case Opt_sec:
1453                         string = match_strdup(args);
1454                         if (string == NULL)
1455                                 goto out_nomem;
1456                         rc = nfs_parse_security_flavors(string, mnt);
1457                         kfree(string);
1458                         if (!rc) {
1459                                 dfprintk(MOUNT, "NFS:   unrecognized "
1460                                                 "security flavor\n");
1461                                 return 0;
1462                         }
1463                         break;
1464                 case Opt_proto:
1465                         string = match_strdup(args);
1466                         if (string == NULL)
1467                                 goto out_nomem;
1468                         token = match_token(string,
1469                                             nfs_xprt_protocol_tokens, args);
1470
1471                         protofamily = AF_INET;
1472                         switch (token) {
1473                         case Opt_xprt_udp6:
1474                                 protofamily = AF_INET6;
1475                                 /* fall through */
1476                         case Opt_xprt_udp:
1477                                 mnt->flags &= ~NFS_MOUNT_TCP;
1478                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1479                                 break;
1480                         case Opt_xprt_tcp6:
1481                                 protofamily = AF_INET6;
1482                                 /* fall through */
1483                         case Opt_xprt_tcp:
1484                                 mnt->flags |= NFS_MOUNT_TCP;
1485                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1486                                 break;
1487                         case Opt_xprt_rdma6:
1488                                 protofamily = AF_INET6;
1489                                 /* fall through */
1490                         case Opt_xprt_rdma:
1491                                 /* vector side protocols to TCP */
1492                                 mnt->flags |= NFS_MOUNT_TCP;
1493                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1494                                 xprt_load_transport(string);
1495                                 break;
1496                         default:
1497                                 dfprintk(MOUNT, "NFS:   unrecognized "
1498                                                 "transport protocol\n");
1499                                 kfree(string);
1500                                 return 0;
1501                         }
1502                         kfree(string);
1503                         break;
1504                 case Opt_mountproto:
1505                         string = match_strdup(args);
1506                         if (string == NULL)
1507                                 goto out_nomem;
1508                         token = match_token(string,
1509                                             nfs_xprt_protocol_tokens, args);
1510                         kfree(string);
1511
1512                         mountfamily = AF_INET;
1513                         switch (token) {
1514                         case Opt_xprt_udp6:
1515                                 mountfamily = AF_INET6;
1516                                 /* fall through */
1517                         case Opt_xprt_udp:
1518                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1519                                 break;
1520                         case Opt_xprt_tcp6:
1521                                 mountfamily = AF_INET6;
1522                                 /* fall through */
1523                         case Opt_xprt_tcp:
1524                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1525                                 break;
1526                         case Opt_xprt_rdma: /* not used for side protocols */
1527                         default:
1528                                 dfprintk(MOUNT, "NFS:   unrecognized "
1529                                                 "transport protocol\n");
1530                                 return 0;
1531                         }
1532                         break;
1533                 case Opt_addr:
1534                         string = match_strdup(args);
1535                         if (string == NULL)
1536                                 goto out_nomem;
1537                         mnt->nfs_server.addrlen =
1538                                 rpc_pton(mnt->net, string, strlen(string),
1539                                         (struct sockaddr *)
1540                                         &mnt->nfs_server.address,
1541                                         sizeof(mnt->nfs_server.address));
1542                         kfree(string);
1543                         if (mnt->nfs_server.addrlen == 0)
1544                                 goto out_invalid_address;
1545                         break;
1546                 case Opt_clientaddr:
1547                         if (nfs_get_option_str(args, &mnt->client_address))
1548                                 goto out_nomem;
1549                         break;
1550                 case Opt_mounthost:
1551                         if (nfs_get_option_str(args,
1552                                                &mnt->mount_server.hostname))
1553                                 goto out_nomem;
1554                         break;
1555                 case Opt_mountaddr:
1556                         string = match_strdup(args);
1557                         if (string == NULL)
1558                                 goto out_nomem;
1559                         mnt->mount_server.addrlen =
1560                                 rpc_pton(mnt->net, string, strlen(string),
1561                                         (struct sockaddr *)
1562                                         &mnt->mount_server.address,
1563                                         sizeof(mnt->mount_server.address));
1564                         kfree(string);
1565                         if (mnt->mount_server.addrlen == 0)
1566                                 goto out_invalid_address;
1567                         break;
1568                 case Opt_nconnect:
1569                         if (nfs_get_option_ul_bound(args, &option, 1, NFS_MAX_CONNECTIONS))
1570                                 goto out_invalid_value;
1571                         mnt->nfs_server.nconnect = option;
1572                         break;
1573                 case Opt_lookupcache:
1574                         string = match_strdup(args);
1575                         if (string == NULL)
1576                                 goto out_nomem;
1577                         token = match_token(string,
1578                                         nfs_lookupcache_tokens, args);
1579                         kfree(string);
1580                         switch (token) {
1581                                 case Opt_lookupcache_all:
1582                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1583                                         break;
1584                                 case Opt_lookupcache_positive:
1585                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1586                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1587                                         break;
1588                                 case Opt_lookupcache_none:
1589                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1590                                         break;
1591                                 default:
1592                                         dfprintk(MOUNT, "NFS:   invalid "
1593                                                         "lookupcache argument\n");
1594                                         return 0;
1595                         };
1596                         break;
1597                 case Opt_fscache_uniq:
1598                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1599                                 goto out_nomem;
1600                         mnt->options |= NFS_OPTION_FSCACHE;
1601                         break;
1602                 case Opt_local_lock:
1603                         string = match_strdup(args);
1604                         if (string == NULL)
1605                                 goto out_nomem;
1606                         token = match_token(string, nfs_local_lock_tokens,
1607                                         args);
1608                         kfree(string);
1609                         switch (token) {
1610                         case Opt_local_lock_all:
1611                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1612                                                NFS_MOUNT_LOCAL_FCNTL);
1613                                 break;
1614                         case Opt_local_lock_flock:
1615                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1616                                 break;
1617                         case Opt_local_lock_posix:
1618                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1619                                 break;
1620                         case Opt_local_lock_none:
1621                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1622                                                 NFS_MOUNT_LOCAL_FCNTL);
1623                                 break;
1624                         default:
1625                                 dfprintk(MOUNT, "NFS:   invalid "
1626                                                 "local_lock argument\n");
1627                                 return 0;
1628                         };
1629                         break;
1630
1631                 /*
1632                  * Special options
1633                  */
1634                 case Opt_sloppy:
1635                         sloppy = 1;
1636                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1637                         break;
1638                 case Opt_userspace:
1639                 case Opt_deprecated:
1640                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1641                                         "'%s'\n", p);
1642                         break;
1643
1644                 default:
1645                         invalid_option = 1;
1646                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1647                                         "'%s'\n", p);
1648                 }
1649         }
1650
1651         if (!sloppy && invalid_option)
1652                 return 0;
1653
1654         if (mnt->minorversion && mnt->version != 4)
1655                 goto out_minorversion_mismatch;
1656
1657         if (mnt->options & NFS_OPTION_MIGRATION &&
1658             (mnt->version != 4 || mnt->minorversion != 0))
1659                 goto out_migration_misuse;
1660
1661         /*
1662          * verify that any proto=/mountproto= options match the address
1663          * families in the addr=/mountaddr= options.
1664          */
1665         if (protofamily != AF_UNSPEC &&
1666             protofamily != mnt->nfs_server.address.ss_family)
1667                 goto out_proto_mismatch;
1668
1669         if (mountfamily != AF_UNSPEC) {
1670                 if (mnt->mount_server.addrlen) {
1671                         if (mountfamily != mnt->mount_server.address.ss_family)
1672                                 goto out_mountproto_mismatch;
1673                 } else {
1674                         if (mountfamily != mnt->nfs_server.address.ss_family)
1675                                 goto out_mountproto_mismatch;
1676                 }
1677         }
1678
1679         return 1;
1680
1681 out_mountproto_mismatch:
1682         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1683                          "option\n");
1684         return 0;
1685 out_proto_mismatch:
1686         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1687         return 0;
1688 out_invalid_address:
1689         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1690         return 0;
1691 out_invalid_value:
1692         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1693         return 0;
1694 out_minorversion_mismatch:
1695         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1696                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1697         return 0;
1698 out_migration_misuse:
1699         printk(KERN_INFO
1700                 "NFS: 'migration' not supported for this NFS version\n");
1701         return 0;
1702 out_nomem:
1703         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1704         return 0;
1705 out_security_failure:
1706         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1707         return 0;
1708 }
1709
1710 /*
1711  * Ensure that a specified authtype in args->auth_info is supported by
1712  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1713  * -EACCES if not.
1714  */
1715 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1716                         rpc_authflavor_t *server_authlist, unsigned int count)
1717 {
1718         rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1719         bool found_auth_null = false;
1720         unsigned int i;
1721
1722         /*
1723          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1724          * must be in the list returned by the server.
1725          *
1726          * AUTH_NULL has a special meaning when it's in the server list - it
1727          * means that the server will ignore the rpc creds, so any flavor
1728          * can be used but still use the sec= that was specified.
1729          *
1730          * Note also that the MNT procedure in MNTv1 does not return a list
1731          * of supported security flavors. In this case, nfs_mount() fabricates
1732          * a security flavor list containing just AUTH_NULL.
1733          */
1734         for (i = 0; i < count; i++) {
1735                 flavor = server_authlist[i];
1736
1737                 if (nfs_auth_info_match(&args->auth_info, flavor))
1738                         goto out;
1739
1740                 if (flavor == RPC_AUTH_NULL)
1741                         found_auth_null = true;
1742         }
1743
1744         if (found_auth_null) {
1745                 flavor = args->auth_info.flavors[0];
1746                 goto out;
1747         }
1748
1749         dfprintk(MOUNT,
1750                  "NFS: specified auth flavors not supported by server\n");
1751         return -EACCES;
1752
1753 out:
1754         args->selected_flavor = flavor;
1755         dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1756         return 0;
1757 }
1758
1759 /*
1760  * Use the remote server's MOUNT service to request the NFS file handle
1761  * corresponding to the provided path.
1762  */
1763 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1764                              struct nfs_fh *root_fh,
1765                              rpc_authflavor_t *server_authlist,
1766                              unsigned int *server_authlist_len)
1767 {
1768         struct nfs_mount_request request = {
1769                 .sap            = (struct sockaddr *)
1770                                                 &args->mount_server.address,
1771                 .dirpath        = args->nfs_server.export_path,
1772                 .protocol       = args->mount_server.protocol,
1773                 .fh             = root_fh,
1774                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1775                 .auth_flav_len  = server_authlist_len,
1776                 .auth_flavs     = server_authlist,
1777                 .net            = args->net,
1778         };
1779         int status;
1780
1781         if (args->mount_server.version == 0) {
1782                 switch (args->version) {
1783                         default:
1784                                 args->mount_server.version = NFS_MNT3_VERSION;
1785                                 break;
1786                         case 2:
1787                                 args->mount_server.version = NFS_MNT_VERSION;
1788                 }
1789         }
1790         request.version = args->mount_server.version;
1791
1792         if (args->mount_server.hostname)
1793                 request.hostname = args->mount_server.hostname;
1794         else
1795                 request.hostname = args->nfs_server.hostname;
1796
1797         /*
1798          * Construct the mount server's address.
1799          */
1800         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1801                 memcpy(request.sap, &args->nfs_server.address,
1802                        args->nfs_server.addrlen);
1803                 args->mount_server.addrlen = args->nfs_server.addrlen;
1804         }
1805         request.salen = args->mount_server.addrlen;
1806         nfs_set_port(request.sap, &args->mount_server.port, 0);
1807
1808         /*
1809          * Now ask the mount server to map our export path
1810          * to a file handle.
1811          */
1812         status = nfs_mount(&request);
1813         if (status != 0) {
1814                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1815                                 request.hostname, status);
1816                 return status;
1817         }
1818
1819         return 0;
1820 }
1821
1822 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1823                                         struct nfs_subversion *nfs_mod)
1824 {
1825         int status;
1826         unsigned int i;
1827         bool tried_auth_unix = false;
1828         bool auth_null_in_list = false;
1829         struct nfs_server *server = ERR_PTR(-EACCES);
1830         struct nfs_parsed_mount_data *args = mount_info->parsed;
1831         rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1832         unsigned int authlist_len = ARRAY_SIZE(authlist);
1833
1834         status = nfs_request_mount(args, mount_info->mntfh, authlist,
1835                                         &authlist_len);
1836         if (status)
1837                 return ERR_PTR(status);
1838
1839         /*
1840          * Was a sec= authflavor specified in the options? First, verify
1841          * whether the server supports it, and then just try to use it if so.
1842          */
1843         if (args->auth_info.flavor_len > 0) {
1844                 status = nfs_verify_authflavors(args, authlist, authlist_len);
1845                 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1846                          args->selected_flavor);
1847                 if (status)
1848                         return ERR_PTR(status);
1849                 return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1850         }
1851
1852         /*
1853          * No sec= option was provided. RFC 2623, section 2.7 suggests we
1854          * SHOULD prefer the flavor listed first. However, some servers list
1855          * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1856          */
1857         for (i = 0; i < authlist_len; ++i) {
1858                 rpc_authflavor_t flavor;
1859                 struct rpcsec_gss_info info;
1860
1861                 flavor = authlist[i];
1862                 switch (flavor) {
1863                 case RPC_AUTH_UNIX:
1864                         tried_auth_unix = true;
1865                         break;
1866                 case RPC_AUTH_NULL:
1867                         auth_null_in_list = true;
1868                         continue;
1869                 default:
1870                         if (rpcauth_get_gssinfo(flavor, &info) != 0)
1871                                 continue;
1872                         /* Fallthrough */
1873                 }
1874                 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1875                 args->selected_flavor = flavor;
1876                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1877                 if (!IS_ERR(server))
1878                         return server;
1879         }
1880
1881         /*
1882          * Nothing we tried so far worked. At this point, give up if we've
1883          * already tried AUTH_UNIX or if the server's list doesn't contain
1884          * AUTH_NULL
1885          */
1886         if (tried_auth_unix || !auth_null_in_list)
1887                 return server;
1888
1889         /* Last chance! Try AUTH_UNIX */
1890         dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1891         args->selected_flavor = RPC_AUTH_UNIX;
1892         return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1893 }
1894
1895 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1896                              struct nfs_mount_info *mount_info,
1897                              struct nfs_subversion *nfs_mod)
1898 {
1899         struct nfs_server *server;
1900
1901         if (mount_info->parsed->need_mount)
1902                 server = nfs_try_mount_request(mount_info, nfs_mod);
1903         else
1904                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1905
1906         if (IS_ERR(server))
1907                 return ERR_CAST(server);
1908
1909         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1910 }
1911 EXPORT_SYMBOL_GPL(nfs_try_mount);
1912
1913 /*
1914  * Split "dev_name" into "hostname:export_path".
1915  *
1916  * The leftmost colon demarks the split between the server's hostname
1917  * and the export path.  If the hostname starts with a left square
1918  * bracket, then it may contain colons.
1919  *
1920  * Note: caller frees hostname and export path, even on error.
1921  */
1922 static int nfs_parse_devname(const char *dev_name,
1923                              char **hostname, size_t maxnamlen,
1924                              char **export_path, size_t maxpathlen)
1925 {
1926         size_t len;
1927         char *end;
1928
1929         if (unlikely(!dev_name || !*dev_name)) {
1930                 dfprintk(MOUNT, "NFS: device name not specified\n");
1931                 return -EINVAL;
1932         }
1933
1934         /* Is the host name protected with square brakcets? */
1935         if (*dev_name == '[') {
1936                 end = strchr(++dev_name, ']');
1937                 if (end == NULL || end[1] != ':')
1938                         goto out_bad_devname;
1939
1940                 len = end - dev_name;
1941                 end++;
1942         } else {
1943                 char *comma;
1944
1945                 end = strchr(dev_name, ':');
1946                 if (end == NULL)
1947                         goto out_bad_devname;
1948                 len = end - dev_name;
1949
1950                 /* kill possible hostname list: not supported */
1951                 comma = strchr(dev_name, ',');
1952                 if (comma != NULL && comma < end)
1953                         len = comma - dev_name;
1954         }
1955
1956         if (len > maxnamlen)
1957                 goto out_hostname;
1958
1959         /* N.B. caller will free nfs_server.hostname in all cases */
1960         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1961         if (*hostname == NULL)
1962                 goto out_nomem;
1963         len = strlen(++end);
1964         if (len > maxpathlen)
1965                 goto out_path;
1966         *export_path = kstrndup(end, len, GFP_KERNEL);
1967         if (!*export_path)
1968                 goto out_nomem;
1969
1970         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1971         return 0;
1972
1973 out_bad_devname:
1974         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1975         return -EINVAL;
1976
1977 out_nomem:
1978         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1979         return -ENOMEM;
1980
1981 out_hostname:
1982         dfprintk(MOUNT, "NFS: server hostname too long\n");
1983         return -ENAMETOOLONG;
1984
1985 out_path:
1986         dfprintk(MOUNT, "NFS: export pathname too long\n");
1987         return -ENAMETOOLONG;
1988 }
1989
1990 /*
1991  * Validate the NFS2/NFS3 mount data
1992  * - fills in the mount root filehandle
1993  *
1994  * For option strings, user space handles the following behaviors:
1995  *
1996  * + DNS: mapping server host name to IP address ("addr=" option)
1997  *
1998  * + failure mode: how to behave if a mount request can't be handled
1999  *   immediately ("fg/bg" option)
2000  *
2001  * + retry: how often to retry a mount request ("retry=" option)
2002  *
2003  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
2004  *   mountproto=tcp after mountproto=udp, and so on
2005  */
2006 static int nfs23_validate_mount_data(void *options,
2007                                      struct nfs_parsed_mount_data *args,
2008                                      struct nfs_fh *mntfh,
2009                                      const char *dev_name)
2010 {
2011         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
2012         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2013         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
2014
2015         if (data == NULL)
2016                 goto out_no_data;
2017
2018         args->version = NFS_DEFAULT_VERSION;
2019         switch (data->version) {
2020         case 1:
2021                 data->namlen = 0; /* fall through */
2022         case 2:
2023                 data->bsize = 0; /* fall through */
2024         case 3:
2025                 if (data->flags & NFS_MOUNT_VER3)
2026                         goto out_no_v3;
2027                 data->root.size = NFS2_FHSIZE;
2028                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
2029                 /* Turn off security negotiation */
2030                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
2031                 /* fall through */
2032         case 4:
2033                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2034                         goto out_no_sec;
2035                 /* fall through */
2036         case 5:
2037                 memset(data->context, 0, sizeof(data->context));
2038                 /* fall through */
2039         case 6:
2040                 if (data->flags & NFS_MOUNT_VER3) {
2041                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2042                                 goto out_invalid_fh;
2043                         mntfh->size = data->root.size;
2044                         args->version = 3;
2045                 } else {
2046                         mntfh->size = NFS2_FHSIZE;
2047                         args->version = 2;
2048                 }
2049
2050
2051                 memcpy(mntfh->data, data->root.data, mntfh->size);
2052                 if (mntfh->size < sizeof(mntfh->data))
2053                         memset(mntfh->data + mntfh->size, 0,
2054                                sizeof(mntfh->data) - mntfh->size);
2055
2056                 /*
2057                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
2058                  * can deal with.
2059                  */
2060                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
2061                 args->flags             |= extra_flags;
2062                 args->rsize             = data->rsize;
2063                 args->wsize             = data->wsize;
2064                 args->timeo             = data->timeo;
2065                 args->retrans           = data->retrans;
2066                 args->acregmin          = data->acregmin;
2067                 args->acregmax          = data->acregmax;
2068                 args->acdirmin          = data->acdirmin;
2069                 args->acdirmax          = data->acdirmax;
2070                 args->need_mount        = false;
2071
2072                 memcpy(sap, &data->addr, sizeof(data->addr));
2073                 args->nfs_server.addrlen = sizeof(data->addr);
2074                 args->nfs_server.port = ntohs(data->addr.sin_port);
2075                 if (sap->sa_family != AF_INET ||
2076                     !nfs_verify_server_address(sap))
2077                         goto out_no_address;
2078
2079                 if (!(data->flags & NFS_MOUNT_TCP))
2080                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2081                 /* N.B. caller will free nfs_server.hostname in all cases */
2082                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2083                 args->namlen            = data->namlen;
2084                 args->bsize             = data->bsize;
2085
2086                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2087                         args->selected_flavor = data->pseudoflavor;
2088                 else
2089                         args->selected_flavor = RPC_AUTH_UNIX;
2090                 if (!args->nfs_server.hostname)
2091                         goto out_nomem;
2092
2093                 if (!(data->flags & NFS_MOUNT_NONLM))
2094                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2095                                          NFS_MOUNT_LOCAL_FCNTL);
2096                 else
2097                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2098                                         NFS_MOUNT_LOCAL_FCNTL);
2099                 /*
2100                  * The legacy version 6 binary mount data from userspace has a
2101                  * field used only to transport selinux information into the
2102                  * the kernel.  To continue to support that functionality we
2103                  * have a touch of selinux knowledge here in the NFS code. The
2104                  * userspace code converted context=blah to just blah so we are
2105                  * converting back to the full string selinux understands.
2106                  */
2107                 if (data->context[0]){
2108 #ifdef CONFIG_SECURITY_SELINUX
2109                         int rc;
2110                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2111                         rc = security_add_mnt_opt("context", data->context,
2112                                         strlen(data->context), &args->lsm_opts);
2113                         if (rc)
2114                                 return rc;
2115 #else
2116                         return -EINVAL;
2117 #endif
2118                 }
2119
2120                 break;
2121         default:
2122                 return NFS_TEXT_DATA;
2123         }
2124
2125         return 0;
2126
2127 out_no_data:
2128         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2129         return -EINVAL;
2130
2131 out_no_v3:
2132         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2133                  data->version);
2134         return -EINVAL;
2135
2136 out_no_sec:
2137         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2138         return -EINVAL;
2139
2140 out_nomem:
2141         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2142         return -ENOMEM;
2143
2144 out_no_address:
2145         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2146         return -EINVAL;
2147
2148 out_invalid_fh:
2149         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2150         return -EINVAL;
2151 }
2152
2153 #if IS_ENABLED(CONFIG_NFS_V4)
2154 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2155                                    void *options,
2156                                    struct nfs_parsed_mount_data *args,
2157                                    struct nfs_fh *mntfh,
2158                                    const char *dev_name)
2159 {
2160         if (fs_type == &nfs_fs_type)
2161                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2162         return nfs4_validate_mount_data(options, args, dev_name);
2163 }
2164 #else
2165 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2166                                    void *options,
2167                                    struct nfs_parsed_mount_data *args,
2168                                    struct nfs_fh *mntfh,
2169                                    const char *dev_name)
2170 {
2171         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2172 }
2173 #endif
2174
2175 static int nfs_validate_text_mount_data(void *options,
2176                                         struct nfs_parsed_mount_data *args,
2177                                         const char *dev_name)
2178 {
2179         int port = 0;
2180         int max_namelen = PAGE_SIZE;
2181         int max_pathlen = NFS_MAXPATHLEN;
2182         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2183
2184         if (nfs_parse_mount_options((char *)options, args) == 0)
2185                 return -EINVAL;
2186
2187         if (!nfs_verify_server_address(sap))
2188                 goto out_no_address;
2189
2190         if (args->version == 4) {
2191 #if IS_ENABLED(CONFIG_NFS_V4)
2192                 if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2193                         port = NFS_RDMA_PORT;
2194                 else
2195                         port = NFS_PORT;
2196                 max_namelen = NFS4_MAXNAMLEN;
2197                 max_pathlen = NFS4_MAXPATHLEN;
2198                 nfs_validate_transport_protocol(args);
2199                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2200                         goto out_invalid_transport_udp;
2201                 nfs4_validate_mount_flags(args);
2202 #else
2203                 goto out_v4_not_compiled;
2204 #endif /* CONFIG_NFS_V4 */
2205         } else {
2206                 nfs_set_mount_transport_protocol(args);
2207                 if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2208                         port = NFS_RDMA_PORT;
2209         }
2210
2211         nfs_set_port(sap, &args->nfs_server.port, port);
2212
2213         return nfs_parse_devname(dev_name,
2214                                    &args->nfs_server.hostname,
2215                                    max_namelen,
2216                                    &args->nfs_server.export_path,
2217                                    max_pathlen);
2218
2219 #if !IS_ENABLED(CONFIG_NFS_V4)
2220 out_v4_not_compiled:
2221         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2222         return -EPROTONOSUPPORT;
2223 #else
2224 out_invalid_transport_udp:
2225         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2226         return -EINVAL;
2227 #endif /* !CONFIG_NFS_V4 */
2228
2229 out_no_address:
2230         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2231         return -EINVAL;
2232 }
2233
2234 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2235                 | NFS_MOUNT_SECURE \
2236                 | NFS_MOUNT_TCP \
2237                 | NFS_MOUNT_VER3 \
2238                 | NFS_MOUNT_KERBEROS \
2239                 | NFS_MOUNT_NONLM \
2240                 | NFS_MOUNT_BROKEN_SUID \
2241                 | NFS_MOUNT_STRICTLOCK \
2242                 | NFS_MOUNT_LEGACY_INTERFACE)
2243
2244 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2245                 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2246
2247 static int
2248 nfs_compare_remount_data(struct nfs_server *nfss,
2249                          struct nfs_parsed_mount_data *data)
2250 {
2251         if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2252             data->rsize != nfss->rsize ||
2253             data->wsize != nfss->wsize ||
2254             data->version != nfss->nfs_client->rpc_ops->version ||
2255             data->minorversion != nfss->nfs_client->cl_minorversion ||
2256             data->retrans != nfss->client->cl_timeout->to_retries ||
2257             !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2258             data->acregmin != nfss->acregmin / HZ ||
2259             data->acregmax != nfss->acregmax / HZ ||
2260             data->acdirmin != nfss->acdirmin / HZ ||
2261             data->acdirmax != nfss->acdirmax / HZ ||
2262             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2263             (data->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
2264             data->nfs_server.port != nfss->port ||
2265             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2266             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2267                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2268                 return -EINVAL;
2269
2270         return 0;
2271 }
2272
2273 int
2274 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2275 {
2276         int error;
2277         struct nfs_server *nfss = sb->s_fs_info;
2278         struct nfs_parsed_mount_data *data;
2279         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2280         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2281         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2282
2283         sync_filesystem(sb);
2284
2285         /*
2286          * Userspace mount programs that send binary options generally send
2287          * them populated with default values. We have no way to know which
2288          * ones were explicitly specified. Fall back to legacy behavior and
2289          * just return success.
2290          */
2291         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2292             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2293                                            options->version <= 6))))
2294                 return 0;
2295
2296         data = nfs_alloc_parsed_mount_data();
2297         if (data == NULL)
2298                 return -ENOMEM;
2299
2300         /* fill out struct with values from existing mount */
2301         data->flags = nfss->flags;
2302         data->rsize = nfss->rsize;
2303         data->wsize = nfss->wsize;
2304         data->retrans = nfss->client->cl_timeout->to_retries;
2305         data->selected_flavor = nfss->client->cl_auth->au_flavor;
2306         data->acregmin = nfss->acregmin / HZ;
2307         data->acregmax = nfss->acregmax / HZ;
2308         data->acdirmin = nfss->acdirmin / HZ;
2309         data->acdirmax = nfss->acdirmax / HZ;
2310         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2311         data->nfs_server.port = nfss->port;
2312         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2313         data->version = nfsvers;
2314         data->minorversion = nfss->nfs_client->cl_minorversion;
2315         data->net = current->nsproxy->net_ns;
2316         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2317                 data->nfs_server.addrlen);
2318
2319         /* overwrite those values with any that were specified */
2320         error = -EINVAL;
2321         if (!nfs_parse_mount_options((char *)options, data))
2322                 goto out;
2323
2324         /*
2325          * noac is a special case. It implies -o sync, but that's not
2326          * necessarily reflected in the mtab options. do_remount_sb
2327          * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2328          * remount options, so we have to explicitly reset it.
2329          */
2330         if (data->flags & NFS_MOUNT_NOAC)
2331                 *flags |= SB_SYNCHRONOUS;
2332
2333         /* compare new mount options with old ones */
2334         error = nfs_compare_remount_data(nfss, data);
2335         if (!error)
2336                 error = security_sb_remount(sb, data->lsm_opts);
2337 out:
2338         nfs_free_parsed_mount_data(data);
2339         return error;
2340 }
2341 EXPORT_SYMBOL_GPL(nfs_remount);
2342
2343 /*
2344  * Initialise the common bits of the superblock
2345  */
2346 static void nfs_initialise_sb(struct super_block *sb)
2347 {
2348         struct nfs_server *server = NFS_SB(sb);
2349
2350         sb->s_magic = NFS_SUPER_MAGIC;
2351
2352         /* We probably want something more informative here */
2353         snprintf(sb->s_id, sizeof(sb->s_id),
2354                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2355
2356         if (sb->s_blocksize == 0)
2357                 sb->s_blocksize = nfs_block_bits(server->wsize,
2358                                                  &sb->s_blocksize_bits);
2359
2360         nfs_super_set_maxbytes(sb, server->maxfilesize);
2361 }
2362
2363 /*
2364  * Finish setting up an NFS2/3 superblock
2365  */
2366 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2367 {
2368         struct nfs_parsed_mount_data *data = mount_info->parsed;
2369         struct nfs_server *server = NFS_SB(sb);
2370
2371         sb->s_blocksize_bits = 0;
2372         sb->s_blocksize = 0;
2373         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2374         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2375         if (data && data->bsize)
2376                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2377
2378         if (server->nfs_client->rpc_ops->version != 2) {
2379                 /* The VFS shouldn't apply the umask to mode bits. We will do
2380                  * so ourselves when necessary.
2381                  */
2382                 sb->s_flags |= SB_POSIXACL;
2383                 sb->s_time_gran = 1;
2384                 sb->s_export_op = &nfs_export_ops;
2385         } else
2386                 sb->s_time_gran = 1000;
2387
2388         if (server->nfs_client->rpc_ops->version != 4) {
2389                 sb->s_time_min = 0;
2390                 sb->s_time_max = U32_MAX;
2391         } else {
2392                 sb->s_time_min = S64_MIN;
2393                 sb->s_time_max = S64_MAX;
2394         }
2395
2396         nfs_initialise_sb(sb);
2397 }
2398 EXPORT_SYMBOL_GPL(nfs_fill_super);
2399
2400 /*
2401  * Finish setting up a cloned NFS2/3/4 superblock
2402  */
2403 static void nfs_clone_super(struct super_block *sb,
2404                             struct nfs_mount_info *mount_info)
2405 {
2406         const struct super_block *old_sb = mount_info->cloned->sb;
2407         struct nfs_server *server = NFS_SB(sb);
2408
2409         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2410         sb->s_blocksize = old_sb->s_blocksize;
2411         sb->s_maxbytes = old_sb->s_maxbytes;
2412         sb->s_xattr = old_sb->s_xattr;
2413         sb->s_op = old_sb->s_op;
2414         sb->s_export_op = old_sb->s_export_op;
2415
2416         if (server->nfs_client->rpc_ops->version != 2) {
2417                 /* The VFS shouldn't apply the umask to mode bits. We will do
2418                  * so ourselves when necessary.
2419                  */
2420                 sb->s_flags |= SB_POSIXACL;
2421                 sb->s_time_gran = 1;
2422         } else
2423                 sb->s_time_gran = 1000;
2424
2425         if (server->nfs_client->rpc_ops->version != 4) {
2426                 sb->s_time_min = 0;
2427                 sb->s_time_max = U32_MAX;
2428         } else {
2429                 sb->s_time_min = S64_MIN;
2430                 sb->s_time_max = S64_MAX;
2431         }
2432
2433         nfs_initialise_sb(sb);
2434 }
2435
2436 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2437 {
2438         const struct nfs_server *a = s->s_fs_info;
2439         const struct rpc_clnt *clnt_a = a->client;
2440         const struct rpc_clnt *clnt_b = b->client;
2441
2442         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2443                 goto Ebusy;
2444         if (a->nfs_client != b->nfs_client)
2445                 goto Ebusy;
2446         if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2447                 goto Ebusy;
2448         if (a->wsize != b->wsize)
2449                 goto Ebusy;
2450         if (a->rsize != b->rsize)
2451                 goto Ebusy;
2452         if (a->acregmin != b->acregmin)
2453                 goto Ebusy;
2454         if (a->acregmax != b->acregmax)
2455                 goto Ebusy;
2456         if (a->acdirmin != b->acdirmin)
2457                 goto Ebusy;
2458         if (a->acdirmax != b->acdirmax)
2459                 goto Ebusy;
2460         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2461                 goto Ebusy;
2462         return 1;
2463 Ebusy:
2464         return 0;
2465 }
2466
2467 struct nfs_sb_mountdata {
2468         struct nfs_server *server;
2469         int mntflags;
2470 };
2471
2472 static int nfs_set_super(struct super_block *s, void *data)
2473 {
2474         struct nfs_sb_mountdata *sb_mntdata = data;
2475         struct nfs_server *server = sb_mntdata->server;
2476         int ret;
2477
2478         s->s_flags = sb_mntdata->mntflags;
2479         s->s_fs_info = server;
2480         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2481         ret = set_anon_super(s, server);
2482         if (ret == 0)
2483                 server->s_dev = s->s_dev;
2484         return ret;
2485 }
2486
2487 static int nfs_compare_super_address(struct nfs_server *server1,
2488                                      struct nfs_server *server2)
2489 {
2490         struct sockaddr *sap1, *sap2;
2491         struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2492         struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2493
2494         if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2495                 return 0;
2496
2497         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2498         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2499
2500         if (sap1->sa_family != sap2->sa_family)
2501                 return 0;
2502
2503         switch (sap1->sa_family) {
2504         case AF_INET: {
2505                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2506                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2507                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2508                         return 0;
2509                 if (sin1->sin_port != sin2->sin_port)
2510                         return 0;
2511                 break;
2512         }
2513         case AF_INET6: {
2514                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2515                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2516                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2517                         return 0;
2518                 if (sin1->sin6_port != sin2->sin6_port)
2519                         return 0;
2520                 break;
2521         }
2522         default:
2523                 return 0;
2524         }
2525
2526         return 1;
2527 }
2528
2529 static int nfs_compare_userns(const struct nfs_server *old,
2530                 const struct nfs_server *new)
2531 {
2532         const struct user_namespace *oldns = &init_user_ns;
2533         const struct user_namespace *newns = &init_user_ns;
2534
2535         if (old->client && old->client->cl_cred)
2536                 oldns = old->client->cl_cred->user_ns;
2537         if (new->client && new->client->cl_cred)
2538                 newns = new->client->cl_cred->user_ns;
2539         if (oldns != newns)
2540                 return 0;
2541         return 1;
2542 }
2543
2544 static int nfs_compare_super(struct super_block *sb, void *data)
2545 {
2546         struct nfs_sb_mountdata *sb_mntdata = data;
2547         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2548         int mntflags = sb_mntdata->mntflags;
2549
2550         if (!nfs_compare_super_address(old, server))
2551                 return 0;
2552         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2553         if (old->flags & NFS_MOUNT_UNSHARED)
2554                 return 0;
2555         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2556                 return 0;
2557         if (!nfs_compare_userns(old, server))
2558                 return 0;
2559         return nfs_compare_mount_options(sb, server, mntflags);
2560 }
2561
2562 #ifdef CONFIG_NFS_FSCACHE
2563 static void nfs_get_cache_cookie(struct super_block *sb,
2564                                  struct nfs_parsed_mount_data *parsed,
2565                                  struct nfs_clone_mount *cloned)
2566 {
2567         struct nfs_server *nfss = NFS_SB(sb);
2568         char *uniq = NULL;
2569         int ulen = 0;
2570
2571         nfss->fscache_key = NULL;
2572         nfss->fscache = NULL;
2573
2574         if (parsed) {
2575                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2576                         return;
2577                 if (parsed->fscache_uniq) {
2578                         uniq = parsed->fscache_uniq;
2579                         ulen = strlen(parsed->fscache_uniq);
2580                 }
2581         } else if (cloned) {
2582                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2583                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2584                         return;
2585                 if (mnt_s->fscache_key) {
2586                         uniq = mnt_s->fscache_key->key.uniquifier;
2587                         ulen = mnt_s->fscache_key->key.uniq_len;
2588                 };
2589         } else
2590                 return;
2591
2592         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2593 }
2594 #else
2595 static void nfs_get_cache_cookie(struct super_block *sb,
2596                                  struct nfs_parsed_mount_data *parsed,
2597                                  struct nfs_clone_mount *cloned)
2598 {
2599 }
2600 #endif
2601
2602 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2603                         struct nfs_mount_info *mount_info)
2604 {
2605         int error;
2606         unsigned long kflags = 0, kflags_out = 0;
2607         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2608                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2609
2610         error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
2611                                                 kflags, &kflags_out);
2612         if (error)
2613                 goto err;
2614
2615         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2616                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2617                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2618 err:
2619         return error;
2620 }
2621 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2622
2623 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2624                           struct nfs_mount_info *mount_info)
2625 {
2626         int error;
2627         unsigned long kflags = 0, kflags_out = 0;
2628
2629         /* clone any lsm security options from the parent to the new sb */
2630         if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2631                 return -ESTALE;
2632
2633         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2634                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2635
2636         error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, kflags,
2637                         &kflags_out);
2638         if (error)
2639                 return error;
2640
2641         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2642                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2643                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2644         return 0;
2645 }
2646 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2647
2648 static void nfs_set_readahead(struct backing_dev_info *bdi,
2649                               unsigned long iomax_pages)
2650 {
2651         bdi->ra_pages = VM_READAHEAD_PAGES;
2652         bdi->io_pages = iomax_pages;
2653 }
2654
2655 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2656                                    int flags, const char *dev_name,
2657                                    struct nfs_mount_info *mount_info,
2658                                    struct nfs_subversion *nfs_mod)
2659 {
2660         struct super_block *s;
2661         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2662         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2663         struct nfs_sb_mountdata sb_mntdata = {
2664                 .mntflags = flags,
2665                 .server = server,
2666         };
2667         int error;
2668
2669         if (server->flags & NFS_MOUNT_UNSHARED)
2670                 compare_super = NULL;
2671
2672         /* -o noac implies -o sync */
2673         if (server->flags & NFS_MOUNT_NOAC)
2674                 sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2675
2676         if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2677                 if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
2678                         sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2679
2680         /* Get a superblock - note that we may end up sharing one that already exists */
2681         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2682         if (IS_ERR(s)) {
2683                 mntroot = ERR_CAST(s);
2684                 goto out_err_nosb;
2685         }
2686
2687         if (s->s_fs_info != server) {
2688                 nfs_free_server(server);
2689                 server = NULL;
2690         } else {
2691                 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
2692                                              MINOR(server->s_dev));
2693                 if (error) {
2694                         mntroot = ERR_PTR(error);
2695                         goto error_splat_super;
2696                 }
2697                 nfs_set_readahead(s->s_bdi, server->rpages);
2698                 server->super = s;
2699         }
2700
2701         if (!s->s_root) {
2702                 /* initial superblock/root creation */
2703                 mount_info->fill_super(s, mount_info);
2704                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2705                 if (!(server->flags & NFS_MOUNT_UNSHARED))
2706                         s->s_iflags |= SB_I_MULTIROOT;
2707         }
2708
2709         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2710         if (IS_ERR(mntroot))
2711                 goto error_splat_super;
2712
2713         error = mount_info->set_security(s, mntroot, mount_info);
2714         if (error)
2715                 goto error_splat_root;
2716
2717         s->s_flags |= SB_ACTIVE;
2718
2719 out:
2720         return mntroot;
2721
2722 out_err_nosb:
2723         nfs_free_server(server);
2724         goto out;
2725
2726 error_splat_root:
2727         dput(mntroot);
2728         mntroot = ERR_PTR(error);
2729 error_splat_super:
2730         deactivate_locked_super(s);
2731         goto out;
2732 }
2733 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2734
2735 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2736         int flags, const char *dev_name, void *raw_data)
2737 {
2738         struct nfs_mount_info mount_info = {
2739                 .fill_super = nfs_fill_super,
2740                 .set_security = nfs_set_sb_security,
2741         };
2742         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2743         struct nfs_subversion *nfs_mod;
2744         int error;
2745
2746         mount_info.parsed = nfs_alloc_parsed_mount_data();
2747         mount_info.mntfh = nfs_alloc_fhandle();
2748         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2749                 goto out;
2750
2751         /* Validate the mount data */
2752         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2753         if (error == NFS_TEXT_DATA)
2754                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2755         if (error < 0) {
2756                 mntroot = ERR_PTR(error);
2757                 goto out;
2758         }
2759
2760         nfs_mod = get_nfs_version(mount_info.parsed->version);
2761         if (IS_ERR(nfs_mod)) {
2762                 mntroot = ERR_CAST(nfs_mod);
2763                 goto out;
2764         }
2765
2766         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2767
2768         put_nfs_version(nfs_mod);
2769 out:
2770         nfs_free_parsed_mount_data(mount_info.parsed);
2771         nfs_free_fhandle(mount_info.mntfh);
2772         return mntroot;
2773 }
2774 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2775
2776 /*
2777  * Destroy an NFS2/3 superblock
2778  */
2779 void nfs_kill_super(struct super_block *s)
2780 {
2781         struct nfs_server *server = NFS_SB(s);
2782         dev_t dev = s->s_dev;
2783
2784         generic_shutdown_super(s);
2785
2786         nfs_fscache_release_super_cookie(s);
2787
2788         nfs_free_server(server);
2789         free_anon_bdev(dev);
2790 }
2791 EXPORT_SYMBOL_GPL(nfs_kill_super);
2792
2793 /*
2794  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2795  */
2796 static struct dentry *
2797 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2798                 const char *dev_name, void *raw_data)
2799 {
2800         struct nfs_clone_mount *data = raw_data;
2801         struct nfs_mount_info mount_info = {
2802                 .fill_super = nfs_clone_super,
2803                 .set_security = nfs_clone_sb_security,
2804                 .cloned = data,
2805         };
2806         struct nfs_server *server;
2807         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2808         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2809
2810         dprintk("--> nfs_xdev_mount()\n");
2811
2812         mount_info.mntfh = mount_info.cloned->fh;
2813
2814         /* create a new volume representation */
2815         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2816
2817         if (IS_ERR(server))
2818                 mntroot = ERR_CAST(server);
2819         else
2820                 mntroot = nfs_fs_mount_common(server, flags,
2821                                 dev_name, &mount_info, nfs_mod);
2822
2823         dprintk("<-- nfs_xdev_mount() = %ld\n",
2824                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2825         return mntroot;
2826 }
2827
2828 #if IS_ENABLED(CONFIG_NFS_V4)
2829
2830 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2831 {
2832         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2833                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2834 }
2835
2836 /*
2837  * Validate NFSv4 mount options
2838  */
2839 static int nfs4_validate_mount_data(void *options,
2840                                     struct nfs_parsed_mount_data *args,
2841                                     const char *dev_name)
2842 {
2843         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2844         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2845         char *c;
2846
2847         if (data == NULL)
2848                 goto out_no_data;
2849
2850         args->version = 4;
2851
2852         switch (data->version) {
2853         case 1:
2854                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2855                         goto out_no_address;
2856                 if (data->host_addrlen == 0)
2857                         goto out_no_address;
2858                 args->nfs_server.addrlen = data->host_addrlen;
2859                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2860                         return -EFAULT;
2861                 if (!nfs_verify_server_address(sap))
2862                         goto out_no_address;
2863                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2864
2865                 if (data->auth_flavourlen) {
2866                         rpc_authflavor_t pseudoflavor;
2867                         if (data->auth_flavourlen > 1)
2868                                 goto out_inval_auth;
2869                         if (copy_from_user(&pseudoflavor,
2870                                            data->auth_flavours,
2871                                            sizeof(pseudoflavor)))
2872                                 return -EFAULT;
2873                         args->selected_flavor = pseudoflavor;
2874                 } else
2875                         args->selected_flavor = RPC_AUTH_UNIX;
2876
2877                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2878                 if (IS_ERR(c))
2879                         return PTR_ERR(c);
2880                 args->nfs_server.hostname = c;
2881
2882                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2883                 if (IS_ERR(c))
2884                         return PTR_ERR(c);
2885                 args->nfs_server.export_path = c;
2886                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2887
2888                 c = strndup_user(data->client_addr.data, 16);
2889                 if (IS_ERR(c))
2890                         return PTR_ERR(c);
2891                 args->client_address = c;
2892
2893                 /*
2894                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2895                  * can deal with.
2896                  */
2897
2898                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2899                 args->rsize     = data->rsize;
2900                 args->wsize     = data->wsize;
2901                 args->timeo     = data->timeo;
2902                 args->retrans   = data->retrans;
2903                 args->acregmin  = data->acregmin;
2904                 args->acregmax  = data->acregmax;
2905                 args->acdirmin  = data->acdirmin;
2906                 args->acdirmax  = data->acdirmax;
2907                 args->nfs_server.protocol = data->proto;
2908                 nfs_validate_transport_protocol(args);
2909                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2910                         goto out_invalid_transport_udp;
2911
2912                 break;
2913         default:
2914                 return NFS_TEXT_DATA;
2915         }
2916
2917         return 0;
2918
2919 out_no_data:
2920         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2921         return -EINVAL;
2922
2923 out_inval_auth:
2924         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2925                  data->auth_flavourlen);
2926         return -EINVAL;
2927
2928 out_no_address:
2929         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2930         return -EINVAL;
2931
2932 out_invalid_transport_udp:
2933         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2934         return -EINVAL;
2935 }
2936
2937 /*
2938  * NFS v4 module parameters need to stay in the
2939  * NFS client for backwards compatibility
2940  */
2941 unsigned int nfs_callback_set_tcpport;
2942 unsigned short nfs_callback_nr_threads;
2943 /* Default cache timeout is 10 minutes */
2944 unsigned int nfs_idmap_cache_timeout = 600;
2945 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2946 bool nfs4_disable_idmapping = true;
2947 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2948 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
2949 unsigned short send_implementation_id = 1;
2950 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2951 bool recover_lost_locks = false;
2952
2953 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
2954 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2955 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2956 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2957 EXPORT_SYMBOL_GPL(max_session_slots);
2958 EXPORT_SYMBOL_GPL(max_session_cb_slots);
2959 EXPORT_SYMBOL_GPL(send_implementation_id);
2960 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2961 EXPORT_SYMBOL_GPL(recover_lost_locks);
2962
2963 #define NFS_CALLBACK_MAXPORTNR (65535U)
2964
2965 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2966 {
2967         unsigned long num;
2968         int ret;
2969
2970         if (!val)
2971                 return -EINVAL;
2972         ret = kstrtoul(val, 0, &num);
2973         if (ret || num > NFS_CALLBACK_MAXPORTNR)
2974                 return -EINVAL;
2975         *((unsigned int *)kp->arg) = num;
2976         return 0;
2977 }
2978 static const struct kernel_param_ops param_ops_portnr = {
2979         .set = param_set_portnr,
2980         .get = param_get_uint,
2981 };
2982 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2983
2984 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2985 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
2986 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
2987                 "assigned to the NFSv4 callback channels.");
2988 module_param(nfs_idmap_cache_timeout, int, 0644);
2989 module_param(nfs4_disable_idmapping, bool, 0644);
2990 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2991                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2992 MODULE_PARM_DESC(nfs4_disable_idmapping,
2993                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2994 module_param(max_session_slots, ushort, 0644);
2995 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2996                 "requests the client will negotiate");
2997 module_param(max_session_cb_slots, ushort, 0644);
2998 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
2999                 "callbacks the client will process for a given server");
3000 module_param(send_implementation_id, ushort, 0644);
3001 MODULE_PARM_DESC(send_implementation_id,
3002                 "Send implementation ID with NFSv4.1 exchange_id");
3003 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
3004
3005 module_param(recover_lost_locks, bool, 0644);
3006 MODULE_PARM_DESC(recover_lost_locks,
3007                  "If the server reports that a lock might be lost, "
3008                  "try to recover it risking data corruption.");
3009
3010
3011 #endif /* CONFIG_NFS_V4 */