fs/nfs/super.c

   1 /*
   2  *  linux/fs/nfs/super.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  *  Split from inode.c by David Howells <dhowells@redhat.com>
  15  *
  16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17  *   particular server are held in the same superblock
  18  * - NFS superblocks can have several effective roots to the dentry tree
  19  * - directory type roots are spliced into the tree when a path from one root reaches the root
  20  *   of another (see nfs_lookup())
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/time.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/unistd.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/addr.h>
  35 #include <linux/sunrpc/stats.h>
  36 #include <linux/sunrpc/metrics.h>
  37 #include <linux/sunrpc/xprtsock.h>
  38 #include <linux/sunrpc/xprtrdma.h>
  39 #include <linux/nfs_fs.h>
  40 #include <linux/nfs_mount.h>
  41 #include <linux/nfs4_mount.h>
  42 #include <linux/lockd/bind.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/namei.h>
  46 #include <linux/vfs.h>
  47 #include <linux/inet.h>
  48 #include <linux/in6.h>
  49 #include <linux/slab.h>
  50 #include <net/ipv6.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/nfs_xdr.h>
  53 #include <linux/magic.h>
  54 #include <linux/parser.h>
  55 #include <linux/nsproxy.h>
  56 #include <linux/rcupdate.h>
  57
  58 #include <linux/uaccess.h>
  59
  60 #include "nfs4_fs.h"
  61 #include "callback.h"
  62 #include "delegation.h"
  63 #include "iostat.h"
  64 #include "internal.h"
  65 #include "fscache.h"
  66 #include "nfs4session.h"
  67 #include "pnfs.h"
  68 #include "nfs.h"
  69
  70 #define NFSDBG_FACILITY         NFSDBG_VFS
  71 #define NFS_TEXT_DATA           1
  72
  73 #if IS_ENABLED(CONFIG_NFS_V3)
  74 #define NFS_DEFAULT_VERSION 3
  75 #else
  76 #define NFS_DEFAULT_VERSION 2
  77 #endif
  78
  79 enum {
  80         /* Mount options that take no arguments */
  81         Opt_soft, Opt_hard,
  82         Opt_posix, Opt_noposix,
  83         Opt_cto, Opt_nocto,
  84         Opt_ac, Opt_noac,
  85         Opt_lock, Opt_nolock,
  86         Opt_udp, Opt_tcp, Opt_rdma,
  87         Opt_acl, Opt_noacl,
  88         Opt_rdirplus, Opt_nordirplus,
  89         Opt_sharecache, Opt_nosharecache,
  90         Opt_resvport, Opt_noresvport,
  91         Opt_fscache, Opt_nofscache,
  92         Opt_migration, Opt_nomigration,
  93
  94         /* Mount options that take integer arguments */
  95         Opt_port,
  96         Opt_rsize, Opt_wsize, Opt_bsize,
  97         Opt_timeo, Opt_retrans,
  98         Opt_acregmin, Opt_acregmax,
  99         Opt_acdirmin, Opt_acdirmax,
 100         Opt_actimeo,
 101         Opt_namelen,
 102         Opt_mountport,
 103         Opt_mountvers,
 104         Opt_minorversion,
 105
 106         /* Mount options that take string arguments */
 107         Opt_nfsvers,
 108         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 109         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 110         Opt_lookupcache,
 111         Opt_fscache_uniq,
 112         Opt_local_lock,
 113
 114         /* Special mount options */
 115         Opt_userspace, Opt_deprecated, Opt_sloppy,
 116
 117         Opt_err
 118 };
 119
 120 static const match_table_t nfs_mount_option_tokens = {
 121         { Opt_userspace, "bg" },
 122         { Opt_userspace, "fg" },
 123         { Opt_userspace, "retry=%s" },
 124
 125         { Opt_sloppy, "sloppy" },
 126
 127         { Opt_soft, "soft" },
 128         { Opt_hard, "hard" },
 129         { Opt_deprecated, "intr" },
 130         { Opt_deprecated, "nointr" },
 131         { Opt_posix, "posix" },
 132         { Opt_noposix, "noposix" },
 133         { Opt_cto, "cto" },
 134         { Opt_nocto, "nocto" },
 135         { Opt_ac, "ac" },
 136         { Opt_noac, "noac" },
 137         { Opt_lock, "lock" },
 138         { Opt_nolock, "nolock" },
 139         { Opt_udp, "udp" },
 140         { Opt_tcp, "tcp" },
 141         { Opt_rdma, "rdma" },
 142         { Opt_acl, "acl" },
 143         { Opt_noacl, "noacl" },
 144         { Opt_rdirplus, "rdirplus" },
 145         { Opt_nordirplus, "nordirplus" },
 146         { Opt_sharecache, "sharecache" },
 147         { Opt_nosharecache, "nosharecache" },
 148         { Opt_resvport, "resvport" },
 149         { Opt_noresvport, "noresvport" },
 150         { Opt_fscache, "fsc" },
 151         { Opt_nofscache, "nofsc" },
 152         { Opt_migration, "migration" },
 153         { Opt_nomigration, "nomigration" },
 154
 155         { Opt_port, "port=%s" },
 156         { Opt_rsize, "rsize=%s" },
 157         { Opt_wsize, "wsize=%s" },
 158         { Opt_bsize, "bsize=%s" },
 159         { Opt_timeo, "timeo=%s" },
 160         { Opt_retrans, "retrans=%s" },
 161         { Opt_acregmin, "acregmin=%s" },
 162         { Opt_acregmax, "acregmax=%s" },
 163         { Opt_acdirmin, "acdirmin=%s" },
 164         { Opt_acdirmax, "acdirmax=%s" },
 165         { Opt_actimeo, "actimeo=%s" },
 166         { Opt_namelen, "namlen=%s" },
 167         { Opt_mountport, "mountport=%s" },
 168         { Opt_mountvers, "mountvers=%s" },
 169         { Opt_minorversion, "minorversion=%s" },
 170
 171         { Opt_nfsvers, "nfsvers=%s" },
 172         { Opt_nfsvers, "vers=%s" },
 173
 174         { Opt_sec, "sec=%s" },
 175         { Opt_proto, "proto=%s" },
 176         { Opt_mountproto, "mountproto=%s" },
 177         { Opt_addr, "addr=%s" },
 178         { Opt_clientaddr, "clientaddr=%s" },
 179         { Opt_mounthost, "mounthost=%s" },
 180         { Opt_mountaddr, "mountaddr=%s" },
 181
 182         { Opt_lookupcache, "lookupcache=%s" },
 183         { Opt_fscache_uniq, "fsc=%s" },
 184         { Opt_local_lock, "local_lock=%s" },
 185
 186         /* The following needs to be listed after all other options */
 187         { Opt_nfsvers, "v%s" },
 188
 189         { Opt_err, NULL }
 190 };
 191
 192 enum {
 193         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 194         Opt_xprt_rdma6,
 195
 196         Opt_xprt_err
 197 };
 198
 199 static const match_table_t nfs_xprt_protocol_tokens = {
 200         { Opt_xprt_udp, "udp" },
 201         { Opt_xprt_udp6, "udp6" },
 202         { Opt_xprt_tcp, "tcp" },
 203         { Opt_xprt_tcp6, "tcp6" },
 204         { Opt_xprt_rdma, "rdma" },
 205         { Opt_xprt_rdma6, "rdma6" },
 206
 207         { Opt_xprt_err, NULL }
 208 };
 209
 210 enum {
 211         Opt_sec_none, Opt_sec_sys,
 212         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 213         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 214         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 215
 216         Opt_sec_err
 217 };
 218
 219 static const match_table_t nfs_secflavor_tokens = {
 220         { Opt_sec_none, "none" },
 221         { Opt_sec_none, "null" },
 222         { Opt_sec_sys, "sys" },
 223
 224         { Opt_sec_krb5, "krb5" },
 225         { Opt_sec_krb5i, "krb5i" },
 226         { Opt_sec_krb5p, "krb5p" },
 227
 228         { Opt_sec_lkey, "lkey" },
 229         { Opt_sec_lkeyi, "lkeyi" },
 230         { Opt_sec_lkeyp, "lkeyp" },
 231
 232         { Opt_sec_spkm, "spkm3" },
 233         { Opt_sec_spkmi, "spkm3i" },
 234         { Opt_sec_spkmp, "spkm3p" },
 235
 236         { Opt_sec_err, NULL }
 237 };
 238
 239 enum {
 240         Opt_lookupcache_all, Opt_lookupcache_positive,
 241         Opt_lookupcache_none,
 242
 243         Opt_lookupcache_err
 244 };
 245
 246 static match_table_t nfs_lookupcache_tokens = {
 247         { Opt_lookupcache_all, "all" },
 248         { Opt_lookupcache_positive, "pos" },
 249         { Opt_lookupcache_positive, "positive" },
 250         { Opt_lookupcache_none, "none" },
 251
 252         { Opt_lookupcache_err, NULL }
 253 };
 254
 255 enum {
 256         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 257         Opt_local_lock_none,
 258
 259         Opt_local_lock_err
 260 };
 261
 262 static match_table_t nfs_local_lock_tokens = {
 263         { Opt_local_lock_all, "all" },
 264         { Opt_local_lock_flock, "flock" },
 265         { Opt_local_lock_posix, "posix" },
 266         { Opt_local_lock_none, "none" },
 267
 268         { Opt_local_lock_err, NULL }
 269 };
 270
 271 enum {
 272         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 273         Opt_vers_4_1, Opt_vers_4_2,
 274
 275         Opt_vers_err
 276 };
 277
 278 static match_table_t nfs_vers_tokens = {
 279         { Opt_vers_2, "2" },
 280         { Opt_vers_3, "3" },
 281         { Opt_vers_4, "4" },
 282         { Opt_vers_4_0, "4.0" },
 283         { Opt_vers_4_1, "4.1" },
 284         { Opt_vers_4_2, "4.2" },
 285
 286         { Opt_vers_err, NULL }
 287 };
 288
 289 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 290                 int flags, const char *dev_name, void *raw_data);
 291
 292 struct file_system_type nfs_fs_type = {
 293         .owner          = THIS_MODULE,
 294         .name           = "nfs",
 295         .mount          = nfs_fs_mount,
 296         .kill_sb        = nfs_kill_super,
 297         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 298 };
 299 MODULE_ALIAS_FS("nfs");
 300 EXPORT_SYMBOL_GPL(nfs_fs_type);
 301
 302 struct file_system_type nfs_xdev_fs_type = {
 303         .owner          = THIS_MODULE,
 304         .name           = "nfs",
 305         .mount          = nfs_xdev_mount,
 306         .kill_sb        = nfs_kill_super,
 307         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 308 };
 309
 310 const struct super_operations nfs_sops = {
 311         .alloc_inode    = nfs_alloc_inode,
 312         .destroy_inode  = nfs_destroy_inode,
 313         .write_inode    = nfs_write_inode,
 314         .drop_inode     = nfs_drop_inode,
 315         .statfs         = nfs_statfs,
 316         .evict_inode    = nfs_evict_inode,
 317         .umount_begin   = nfs_umount_begin,
 318         .show_options   = nfs_show_options,
 319         .show_devname   = nfs_show_devname,
 320         .show_path      = nfs_show_path,
 321         .show_stats     = nfs_show_stats,
 322         .remount_fs     = nfs_remount,
 323 };
 324 EXPORT_SYMBOL_GPL(nfs_sops);
 325
 326 #if IS_ENABLED(CONFIG_NFS_V4)
 327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
 328 static int nfs4_validate_mount_data(void *options,
 329         struct nfs_parsed_mount_data *args, const char *dev_name);
 330
 331 struct file_system_type nfs4_fs_type = {
 332         .owner          = THIS_MODULE,
 333         .name           = "nfs4",
 334         .mount          = nfs_fs_mount,
 335         .kill_sb        = nfs_kill_super,
 336         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 337 };
 338 MODULE_ALIAS_FS("nfs4");
 339 MODULE_ALIAS("nfs4");
 340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 341
 342 static int __init register_nfs4_fs(void)
 343 {
 344         return register_filesystem(&nfs4_fs_type);
 345 }
 346
 347 static void unregister_nfs4_fs(void)
 348 {
 349         unregister_filesystem(&nfs4_fs_type);
 350 }
 351 #else
 352 static int __init register_nfs4_fs(void)
 353 {
 354         return 0;
 355 }
 356
 357 static void unregister_nfs4_fs(void)
 358 {
 359 }
 360 #endif
 361
 362 static struct shrinker acl_shrinker = {
 363         .count_objects  = nfs_access_cache_count,
 364         .scan_objects   = nfs_access_cache_scan,
 365         .seeks          = DEFAULT_SEEKS,
 366 };
 367
 368 /*
 369  * Register the NFS filesystems
 370  */
 371 int __init register_nfs_fs(void)
 372 {
 373         int ret;
 374
 375         ret = register_filesystem(&nfs_fs_type);
 376         if (ret < 0)
 377                 goto error_0;
 378
 379         ret = register_nfs4_fs();
 380         if (ret < 0)
 381                 goto error_1;
 382
 383         ret = nfs_register_sysctl();
 384         if (ret < 0)
 385                 goto error_2;
 386         ret = register_shrinker(&acl_shrinker);
 387         if (ret < 0)
 388                 goto error_3;
 389         return 0;
 390 error_3:
 391         nfs_unregister_sysctl();
 392 error_2:
 393         unregister_nfs4_fs();
 394 error_1:
 395         unregister_filesystem(&nfs_fs_type);
 396 error_0:
 397         return ret;
 398 }
 399
 400 /*
 401  * Unregister the NFS filesystems
 402  */
 403 void __exit unregister_nfs_fs(void)
 404 {
 405         unregister_shrinker(&acl_shrinker);
 406         nfs_unregister_sysctl();
 407         unregister_nfs4_fs();
 408         unregister_filesystem(&nfs_fs_type);
 409 }
 410
 411 bool nfs_sb_active(struct super_block *sb)
 412 {
 413         struct nfs_server *server = NFS_SB(sb);
 414
 415         if (!atomic_inc_not_zero(&sb->s_active))
 416                 return false;
 417         if (atomic_inc_return(&server->active) != 1)
 418                 atomic_dec(&sb->s_active);
 419         return true;
 420 }
 421 EXPORT_SYMBOL_GPL(nfs_sb_active);
 422
 423 void nfs_sb_deactive(struct super_block *sb)
 424 {
 425         struct nfs_server *server = NFS_SB(sb);
 426
 427         if (atomic_dec_and_test(&server->active))
 428                 deactivate_super(sb);
 429 }
 430 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
 431
 432 /*
 433  * Deliver file system statistics to userspace
 434  */
 435 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 436 {
 437         struct nfs_server *server = NFS_SB(dentry->d_sb);
 438         unsigned char blockbits;
 439         unsigned long blockres;
 440         struct nfs_fh *fh = NFS_FH(d_inode(dentry));
 441         struct nfs_fsstat res;
 442         int error = -ENOMEM;
 443
 444         res.fattr = nfs_alloc_fattr();
 445         if (res.fattr == NULL)
 446                 goto out_err;
 447
 448         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 449         if (unlikely(error == -ESTALE)) {
 450                 struct dentry *pd_dentry;
 451
 452                 pd_dentry = dget_parent(dentry);
 453                 if (pd_dentry != NULL) {
 454                         nfs_zap_caches(d_inode(pd_dentry));
 455                         dput(pd_dentry);
 456                 }
 457         }
 458         nfs_free_fattr(res.fattr);
 459         if (error < 0)
 460                 goto out_err;
 461
 462         buf->f_type = NFS_SUPER_MAGIC;
 463
 464         /*
 465          * Current versions of glibc do not correctly handle the
 466          * case where f_frsize != f_bsize.  Eventually we want to
 467          * report the value of wtmult in this field.
 468          */
 469         buf->f_frsize = dentry->d_sb->s_blocksize;
 470
 471         /*
 472          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 473          * are reported in units of f_frsize.  Linux hasn't had
 474          * an f_frsize field in its statfs struct until recently,
 475          * thus historically Linux's sys_statfs reports these
 476          * fields in units of f_bsize.
 477          */
 478         buf->f_bsize = dentry->d_sb->s_blocksize;
 479         blockbits = dentry->d_sb->s_blocksize_bits;
 480         blockres = (1 << blockbits) - 1;
 481         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 482         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 483         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 484
 485         buf->f_files = res.tfiles;
 486         buf->f_ffree = res.afiles;
 487
 488         buf->f_namelen = server->namelen;
 489
 490         return 0;
 491
 492  out_err:
 493         dprintk("%s: statfs error = %d\n", __func__, -error);
 494         return error;
 495 }
 496 EXPORT_SYMBOL_GPL(nfs_statfs);
 497
 498 /*
 499  * Map the security flavour number to a name
 500  */
 501 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 502 {
 503         static const struct {
 504                 rpc_authflavor_t flavour;
 505                 const char *str;
 506         } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
 507                 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
 508                 { RPC_AUTH_NULL, "null" },
 509                 { RPC_AUTH_UNIX, "sys" },
 510                 { RPC_AUTH_GSS_KRB5, "krb5" },
 511                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 512                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 513                 { RPC_AUTH_GSS_LKEY, "lkey" },
 514                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 515                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 516                 { RPC_AUTH_GSS_SPKM, "spkm" },
 517                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 518                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 519                 { UINT_MAX, "unknown" }
 520         };
 521         int i;
 522
 523         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 524                 if (sec_flavours[i].flavour == flavour)
 525                         break;
 526         }
 527         return sec_flavours[i].str;
 528 }
 529
 530 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 531                                   int showdefaults)
 532 {
 533         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 534         char *proto = NULL;
 535
 536         switch (sap->sa_family) {
 537         case AF_INET:
 538                 switch (nfss->mountd_protocol) {
 539                 case IPPROTO_UDP:
 540                         proto = RPCBIND_NETID_UDP;
 541                         break;
 542                 case IPPROTO_TCP:
 543                         proto = RPCBIND_NETID_TCP;
 544                         break;
 545                 }
 546                 break;
 547         case AF_INET6:
 548                 switch (nfss->mountd_protocol) {
 549                 case IPPROTO_UDP:
 550                         proto = RPCBIND_NETID_UDP6;
 551                         break;
 552                 case IPPROTO_TCP:
 553                         proto = RPCBIND_NETID_TCP6;
 554                         break;
 555                 }
 556                 break;
 557         }
 558         if (proto || showdefaults)
 559                 seq_printf(m, ",mountproto=%s", proto ?: "auto");
 560 }
 561
 562 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 563                                     int showdefaults)
 564 {
 565         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 566
 567         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 568                 return;
 569
 570         switch (sap->sa_family) {
 571         case AF_INET: {
 572                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 573                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 574                 break;
 575         }
 576         case AF_INET6: {
 577                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 578                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 579                 break;
 580         }
 581         default:
 582                 if (showdefaults)
 583                         seq_printf(m, ",mountaddr=unspecified");
 584         }
 585
 586         if (nfss->mountd_version || showdefaults)
 587                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 588         if ((nfss->mountd_port &&
 589                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 590                 showdefaults)
 591                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 592
 593         nfs_show_mountd_netid(m, nfss, showdefaults);
 594 }
 595
 596 #if IS_ENABLED(CONFIG_NFS_V4)
 597 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 598                                     int showdefaults)
 599 {
 600         struct nfs_client *clp = nfss->nfs_client;
 601
 602         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 603 }
 604 #else
 605 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 606                                     int showdefaults)
 607 {
 608 }
 609 #endif
 610
 611 static void nfs_show_nfs_version(struct seq_file *m,
 612                 unsigned int version,
 613                 unsigned int minorversion)
 614 {
 615         seq_printf(m, ",vers=%u", version);
 616         if (version == 4)
 617                 seq_printf(m, ".%u", minorversion);
 618 }
 619
 620 /*
 621  * Describe the mount options in force on this server representation
 622  */
 623 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 624                                    int showdefaults)
 625 {
 626         static const struct proc_nfs_info {
 627                 int flag;
 628                 const char *str;
 629                 const char *nostr;
 630         } nfs_info[] = {
 631                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 632                 { NFS_MOUNT_POSIX, ",posix", "" },
 633                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 634                 { NFS_MOUNT_NOAC, ",noac", "" },
 635                 { NFS_MOUNT_NONLM, ",nolock", "" },
 636                 { NFS_MOUNT_NOACL, ",noacl", "" },
 637                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 638                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 639                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 640                 { 0, NULL, NULL }
 641         };
 642         const struct proc_nfs_info *nfs_infop;
 643         struct nfs_client *clp = nfss->nfs_client;
 644         u32 version = clp->rpc_ops->version;
 645         int local_flock, local_fcntl;
 646
 647         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 648         seq_printf(m, ",rsize=%u", nfss->rsize);
 649         seq_printf(m, ",wsize=%u", nfss->wsize);
 650         if (nfss->bsize != 0)
 651                 seq_printf(m, ",bsize=%u", nfss->bsize);
 652         seq_printf(m, ",namlen=%u", nfss->namelen);
 653         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 654                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 655         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 656                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 657         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 658                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 659         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 660                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 661         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 662                 if (nfss->flags & nfs_infop->flag)
 663                         seq_puts(m, nfs_infop->str);
 664                 else
 665                         seq_puts(m, nfs_infop->nostr);
 666         }
 667         rcu_read_lock();
 668         seq_printf(m, ",proto=%s",
 669                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 670         rcu_read_unlock();
 671         if (version == 4) {
 672                 if (nfss->port != NFS_PORT)
 673                         seq_printf(m, ",port=%u", nfss->port);
 674         } else
 675                 if (nfss->port)
 676                         seq_printf(m, ",port=%u", nfss->port);
 677
 678         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 679         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 680         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 681
 682         if (version != 4)
 683                 nfs_show_mountd_options(m, nfss, showdefaults);
 684         else
 685                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 686
 687         if (nfss->options & NFS_OPTION_FSCACHE)
 688                 seq_printf(m, ",fsc");
 689
 690         if (nfss->options & NFS_OPTION_MIGRATION)
 691                 seq_printf(m, ",migration");
 692
 693         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 694                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 695                         seq_printf(m, ",lookupcache=none");
 696                 else
 697                         seq_printf(m, ",lookupcache=pos");
 698         }
 699
 700         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 701         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 702
 703         if (!local_flock && !local_fcntl)
 704                 seq_printf(m, ",local_lock=none");
 705         else if (local_flock && local_fcntl)
 706                 seq_printf(m, ",local_lock=all");
 707         else if (local_flock)
 708                 seq_printf(m, ",local_lock=flock");
 709         else
 710                 seq_printf(m, ",local_lock=posix");
 711 }
 712
 713 /*
 714  * Describe the mount options on this VFS mountpoint
 715  */
 716 int nfs_show_options(struct seq_file *m, struct dentry *root)
 717 {
 718         struct nfs_server *nfss = NFS_SB(root->d_sb);
 719
 720         nfs_show_mount_options(m, nfss, 0);
 721
 722         rcu_read_lock();
 723         seq_printf(m, ",addr=%s",
 724                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 725                                                         RPC_DISPLAY_ADDR));
 726         rcu_read_unlock();
 727
 728         return 0;
 729 }
 730 EXPORT_SYMBOL_GPL(nfs_show_options);
 731
 732 #if IS_ENABLED(CONFIG_NFS_V4)
 733 #ifdef CONFIG_NFS_V4_1
 734 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 735 {
 736         if (nfs4_has_session(server->nfs_client))
 737                 seq_printf(m, ",sessions");
 738 }
 739 #else
 740 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 741 #endif
 742 #endif
 743
 744 #ifdef CONFIG_NFS_V4_1
 745 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 746 {
 747         seq_printf(m, ",pnfs=");
 748         if (server->pnfs_curr_ld)
 749                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 750         else
 751                 seq_printf(m, "not configured");
 752 }
 753
 754 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 755 {
 756         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 757                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 758                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 759                            "date='%llu,%u'",
 760                            impl_id->name, impl_id->domain,
 761                            impl_id->date.seconds, impl_id->date.nseconds);
 762         }
 763 }
 764 #else
 765 #if IS_ENABLED(CONFIG_NFS_V4)
 766 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 767 {
 768 }
 769 #endif
 770 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 771 {
 772 }
 773 #endif
 774
 775 int nfs_show_devname(struct seq_file *m, struct dentry *root)
 776 {
 777         char *page = (char *) __get_free_page(GFP_KERNEL);
 778         char *devname, *dummy;
 779         int err = 0;
 780         if (!page)
 781                 return -ENOMEM;
 782         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
 783         if (IS_ERR(devname))
 784                 err = PTR_ERR(devname);
 785         else
 786                 seq_escape(m, devname, " \t\n\\");
 787         free_page((unsigned long)page);
 788         return err;
 789 }
 790 EXPORT_SYMBOL_GPL(nfs_show_devname);
 791
 792 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 793 {
 794         seq_puts(m, "/");
 795         return 0;
 796 }
 797 EXPORT_SYMBOL_GPL(nfs_show_path);
 798
 799 /*
 800  * Present statistical information for this VFS mountpoint
 801  */
 802 int nfs_show_stats(struct seq_file *m, struct dentry *root)
 803 {
 804         int i, cpu;
 805         struct nfs_server *nfss = NFS_SB(root->d_sb);
 806         struct rpc_auth *auth = nfss->client->cl_auth;
 807         struct nfs_iostats totals = { };
 808
 809         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 810
 811         /*
 812          * Display all mount option settings
 813          */
 814         seq_printf(m, "\n\topts:\t");
 815         seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
 816         seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
 817         seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
 818         seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
 819         nfs_show_mount_options(m, nfss, 1);
 820
 821         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 822
 823         show_implementation_id(m, nfss);
 824
 825         seq_printf(m, "\n\tcaps:\t");
 826         seq_printf(m, "caps=0x%x", nfss->caps);
 827         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 828         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 829         seq_printf(m, ",bsize=%u", nfss->bsize);
 830         seq_printf(m, ",namlen=%u", nfss->namelen);
 831
 832 #if IS_ENABLED(CONFIG_NFS_V4)
 833         if (nfss->nfs_client->rpc_ops->version == 4) {
 834                 seq_printf(m, "\n\tnfsv4:\t");
 835                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 836                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 837                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
 838                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 839                 show_sessions(m, nfss);
 840                 show_pnfs(m, nfss);
 841         }
 842 #endif
 843
 844         /*
 845          * Display security flavor in effect for this mount
 846          */
 847         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 848         if (auth->au_flavor)
 849                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 850
 851         /*
 852          * Display superblock I/O counters
 853          */
 854         for_each_possible_cpu(cpu) {
 855                 struct nfs_iostats *stats;
 856
 857                 preempt_disable();
 858                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 859
 860                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 861                         totals.events[i] += stats->events[i];
 862                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 863                         totals.bytes[i] += stats->bytes[i];
 864 #ifdef CONFIG_NFS_FSCACHE
 865                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 866                         totals.fscache[i] += stats->fscache[i];
 867 #endif
 868
 869                 preempt_enable();
 870         }
 871
 872         seq_printf(m, "\n\tevents:\t");
 873         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 874                 seq_printf(m, "%lu ", totals.events[i]);
 875         seq_printf(m, "\n\tbytes:\t");
 876         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 877                 seq_printf(m, "%Lu ", totals.bytes[i]);
 878 #ifdef CONFIG_NFS_FSCACHE
 879         if (nfss->options & NFS_OPTION_FSCACHE) {
 880                 seq_printf(m, "\n\tfsc:\t");
 881                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 882                         seq_printf(m, "%Lu ", totals.fscache[i]);
 883         }
 884 #endif
 885         seq_printf(m, "\n");
 886
 887         rpc_clnt_show_stats(m, nfss->client);
 888
 889         return 0;
 890 }
 891 EXPORT_SYMBOL_GPL(nfs_show_stats);
 892
 893 /*
 894  * Begin unmount by attempting to remove all automounted mountpoints we added
 895  * in response to xdev traversals and referrals
 896  */
 897 void nfs_umount_begin(struct super_block *sb)
 898 {
 899         struct nfs_server *server;
 900         struct rpc_clnt *rpc;
 901
 902         server = NFS_SB(sb);
 903         /* -EIO all pending I/O */
 904         rpc = server->client_acl;
 905         if (!IS_ERR(rpc))
 906                 rpc_killall_tasks(rpc);
 907         rpc = server->client;
 908         if (!IS_ERR(rpc))
 909                 rpc_killall_tasks(rpc);
 910 }
 911 EXPORT_SYMBOL_GPL(nfs_umount_begin);
 912
 913 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 914 {
 915         struct nfs_parsed_mount_data *data;
 916
 917         data = kzalloc(sizeof(*data), GFP_KERNEL);
 918         if (data) {
 919                 data->timeo             = NFS_UNSPEC_TIMEO;
 920                 data->retrans           = NFS_UNSPEC_RETRANS;
 921                 data->acregmin          = NFS_DEF_ACREGMIN;
 922                 data->acregmax          = NFS_DEF_ACREGMAX;
 923                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 924                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 925                 data->mount_server.port = NFS_UNSPEC_PORT;
 926                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 927                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 928                 data->selected_flavor   = RPC_AUTH_MAXFLAVOR;
 929                 data->minorversion      = 0;
 930                 data->need_mount        = true;
 931                 data->net               = current->nsproxy->net_ns;
 932                 data->lsm_opts          = NULL;
 933         }
 934         return data;
 935 }
 936
 937 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 938 {
 939         if (data) {
 940                 kfree(data->client_address);
 941                 kfree(data->mount_server.hostname);
 942                 kfree(data->nfs_server.export_path);
 943                 kfree(data->nfs_server.hostname);
 944                 kfree(data->fscache_uniq);
 945                 security_free_mnt_opts(&data->lsm_opts);
 946                 kfree(data);
 947         }
 948 }
 949
 950 /*
 951  * Sanity-check a server address provided by the mount command.
 952  *
 953  * Address family must be initialized, and address must not be
 954  * the ANY address for that family.
 955  */
 956 static int nfs_verify_server_address(struct sockaddr *addr)
 957 {
 958         switch (addr->sa_family) {
 959         case AF_INET: {
 960                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 961                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 962         }
 963         case AF_INET6: {
 964                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 965                 return !ipv6_addr_any(sa);
 966         }
 967         }
 968
 969         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 970         return 0;
 971 }
 972
 973 /*
 974  * Select between a default port value and a user-specified port value.
 975  * If a zero value is set, then autobind will be used.
 976  */
 977 static void nfs_set_port(struct sockaddr *sap, int *port,
 978                                  const unsigned short default_port)
 979 {
 980         if (*port == NFS_UNSPEC_PORT)
 981                 *port = default_port;
 982
 983         rpc_set_port(sap, *port);
 984 }
 985
 986 /*
 987  * Sanity check the NFS transport protocol.
 988  *
 989  */
 990 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 991 {
 992         switch (mnt->nfs_server.protocol) {
 993         case XPRT_TRANSPORT_UDP:
 994         case XPRT_TRANSPORT_TCP:
 995         case XPRT_TRANSPORT_RDMA:
 996                 break;
 997         default:
 998                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 999         }
1000 }
1001
1002 /*
1003  * For text based NFSv2/v3 mounts, the mount protocol transport default
1004  * settings should depend upon the specified NFS transport.
1005  */
1006 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1007 {
1008         nfs_validate_transport_protocol(mnt);
1009
1010         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1011             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1012                         return;
1013         switch (mnt->nfs_server.protocol) {
1014         case XPRT_TRANSPORT_UDP:
1015                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1016                 break;
1017         case XPRT_TRANSPORT_TCP:
1018         case XPRT_TRANSPORT_RDMA:
1019                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1020         }
1021 }
1022
1023 /*
1024  * Add 'flavor' to 'auth_info' if not already present.
1025  * Returns true if 'flavor' ends up in the list, false otherwise
1026  */
1027 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1028                               rpc_authflavor_t flavor)
1029 {
1030         unsigned int i;
1031         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1032
1033         /* make sure this flavor isn't already in the list */
1034         for (i = 0; i < auth_info->flavor_len; i++) {
1035                 if (flavor == auth_info->flavors[i])
1036                         return true;
1037         }
1038
1039         if (auth_info->flavor_len + 1 >= max_flavor_len) {
1040                 dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1041                 return false;
1042         }
1043
1044         auth_info->flavors[auth_info->flavor_len++] = flavor;
1045         return true;
1046 }
1047
1048 /*
1049  * Return true if 'match' is in auth_info or auth_info is empty.
1050  * Return false otherwise.
1051  */
1052 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1053                          rpc_authflavor_t match)
1054 {
1055         int i;
1056
1057         if (!auth_info->flavor_len)
1058                 return true;
1059
1060         for (i = 0; i < auth_info->flavor_len; i++) {
1061                 if (auth_info->flavors[i] == match)
1062                         return true;
1063         }
1064         return false;
1065 }
1066 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1067
1068 /*
1069  * Parse the value of the 'sec=' option.
1070  */
1071 static int nfs_parse_security_flavors(char *value,
1072                                       struct nfs_parsed_mount_data *mnt)
1073 {
1074         substring_t args[MAX_OPT_ARGS];
1075         rpc_authflavor_t pseudoflavor;
1076         char *p;
1077
1078         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1079
1080         while ((p = strsep(&value, ":")) != NULL) {
1081                 switch (match_token(p, nfs_secflavor_tokens, args)) {
1082                 case Opt_sec_none:
1083                         pseudoflavor = RPC_AUTH_NULL;
1084                         break;
1085                 case Opt_sec_sys:
1086                         pseudoflavor = RPC_AUTH_UNIX;
1087                         break;
1088                 case Opt_sec_krb5:
1089                         pseudoflavor = RPC_AUTH_GSS_KRB5;
1090                         break;
1091                 case Opt_sec_krb5i:
1092                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
1093                         break;
1094                 case Opt_sec_krb5p:
1095                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
1096                         break;
1097                 case Opt_sec_lkey:
1098                         pseudoflavor = RPC_AUTH_GSS_LKEY;
1099                         break;
1100                 case Opt_sec_lkeyi:
1101                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
1102                         break;
1103                 case Opt_sec_lkeyp:
1104                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
1105                         break;
1106                 case Opt_sec_spkm:
1107                         pseudoflavor = RPC_AUTH_GSS_SPKM;
1108                         break;
1109                 case Opt_sec_spkmi:
1110                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
1111                         break;
1112                 case Opt_sec_spkmp:
1113                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
1114                         break;
1115                 default:
1116                         dfprintk(MOUNT,
1117                                  "NFS: sec= option '%s' not recognized\n", p);
1118                         return 0;
1119                 }
1120
1121                 if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1122                         return 0;
1123         }
1124
1125         return 1;
1126 }
1127
1128 static int nfs_parse_version_string(char *string,
1129                 struct nfs_parsed_mount_data *mnt,
1130                 substring_t *args)
1131 {
1132         mnt->flags &= ~NFS_MOUNT_VER3;
1133         switch (match_token(string, nfs_vers_tokens, args)) {
1134         case Opt_vers_2:
1135                 mnt->version = 2;
1136                 break;
1137         case Opt_vers_3:
1138                 mnt->flags |= NFS_MOUNT_VER3;
1139                 mnt->version = 3;
1140                 break;
1141         case Opt_vers_4:
1142                 /* Backward compatibility option. In future,
1143                  * the mount program should always supply
1144                  * a NFSv4 minor version number.
1145                  */
1146                 mnt->version = 4;
1147                 break;
1148         case Opt_vers_4_0:
1149                 mnt->version = 4;
1150                 mnt->minorversion = 0;
1151                 break;
1152         case Opt_vers_4_1:
1153                 mnt->version = 4;
1154                 mnt->minorversion = 1;
1155                 break;
1156         case Opt_vers_4_2:
1157                 mnt->version = 4;
1158                 mnt->minorversion = 2;
1159                 break;
1160         default:
1161                 return 0;
1162         }
1163         return 1;
1164 }
1165
1166 static int nfs_get_option_str(substring_t args[], char **option)
1167 {
1168         kfree(*option);
1169         *option = match_strdup(args);
1170         return !*option;
1171 }
1172
1173 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1174 {
1175         int rc;
1176         char *string;
1177
1178         string = match_strdup(args);
1179         if (string == NULL)
1180                 return -ENOMEM;
1181         rc = kstrtoul(string, 10, option);
1182         kfree(string);
1183
1184         return rc;
1185 }
1186
1187 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1188                 unsigned long l_bound, unsigned long u_bound)
1189 {
1190         int ret;
1191
1192         ret = nfs_get_option_ul(args, option);
1193         if (ret != 0)
1194                 return ret;
1195         if (*option < l_bound || *option > u_bound)
1196                 return -ERANGE;
1197         return 0;
1198 }
1199
1200 /*
1201  * Error-check and convert a string of mount options from user space into
1202  * a data structure.  The whole mount string is processed; bad options are
1203  * skipped as they are encountered.  If there were no errors, return 1;
1204  * otherwise return 0 (zero).
1205  */
1206 static int nfs_parse_mount_options(char *raw,
1207                                    struct nfs_parsed_mount_data *mnt)
1208 {
1209         char *p, *string;
1210         int rc, sloppy = 0, invalid_option = 0;
1211         unsigned short protofamily = AF_UNSPEC;
1212         unsigned short mountfamily = AF_UNSPEC;
1213
1214         if (!raw) {
1215                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1216                 return 1;
1217         }
1218         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1219
1220         rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1221         if (rc)
1222                 goto out_security_failure;
1223
1224         while ((p = strsep(&raw, ",")) != NULL) {
1225                 substring_t args[MAX_OPT_ARGS];
1226                 unsigned long option;
1227                 int token;
1228
1229                 if (!*p)
1230                         continue;
1231
1232                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1233
1234                 token = match_token(p, nfs_mount_option_tokens, args);
1235                 switch (token) {
1236
1237                 /*
1238                  * boolean options:  foo/nofoo
1239                  */
1240                 case Opt_soft:
1241                         mnt->flags |= NFS_MOUNT_SOFT;
1242                         break;
1243                 case Opt_hard:
1244                         mnt->flags &= ~NFS_MOUNT_SOFT;
1245                         break;
1246                 case Opt_posix:
1247                         mnt->flags |= NFS_MOUNT_POSIX;
1248                         break;
1249                 case Opt_noposix:
1250                         mnt->flags &= ~NFS_MOUNT_POSIX;
1251                         break;
1252                 case Opt_cto:
1253                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1254                         break;
1255                 case Opt_nocto:
1256                         mnt->flags |= NFS_MOUNT_NOCTO;
1257                         break;
1258                 case Opt_ac:
1259                         mnt->flags &= ~NFS_MOUNT_NOAC;
1260                         break;
1261                 case Opt_noac:
1262                         mnt->flags |= NFS_MOUNT_NOAC;
1263                         break;
1264                 case Opt_lock:
1265                         mnt->flags &= ~NFS_MOUNT_NONLM;
1266                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1267                                         NFS_MOUNT_LOCAL_FCNTL);
1268                         break;
1269                 case Opt_nolock:
1270                         mnt->flags |= NFS_MOUNT_NONLM;
1271                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1272                                        NFS_MOUNT_LOCAL_FCNTL);
1273                         break;
1274                 case Opt_udp:
1275                         mnt->flags &= ~NFS_MOUNT_TCP;
1276                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1277                         break;
1278                 case Opt_tcp:
1279                         mnt->flags |= NFS_MOUNT_TCP;
1280                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1281                         break;
1282                 case Opt_rdma:
1283                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1284                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1285                         xprt_load_transport(p);
1286                         break;
1287                 case Opt_acl:
1288                         mnt->flags &= ~NFS_MOUNT_NOACL;
1289                         break;
1290                 case Opt_noacl:
1291                         mnt->flags |= NFS_MOUNT_NOACL;
1292                         break;
1293                 case Opt_rdirplus:
1294                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1295                         break;
1296                 case Opt_nordirplus:
1297                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1298                         break;
1299                 case Opt_sharecache:
1300                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1301                         break;
1302                 case Opt_nosharecache:
1303                         mnt->flags |= NFS_MOUNT_UNSHARED;
1304                         break;
1305                 case Opt_resvport:
1306                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1307                         break;
1308                 case Opt_noresvport:
1309                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1310                         break;
1311                 case Opt_fscache:
1312                         mnt->options |= NFS_OPTION_FSCACHE;
1313                         kfree(mnt->fscache_uniq);
1314                         mnt->fscache_uniq = NULL;
1315                         break;
1316                 case Opt_nofscache:
1317                         mnt->options &= ~NFS_OPTION_FSCACHE;
1318                         kfree(mnt->fscache_uniq);
1319                         mnt->fscache_uniq = NULL;
1320                         break;
1321                 case Opt_migration:
1322                         mnt->options |= NFS_OPTION_MIGRATION;
1323                         break;
1324                 case Opt_nomigration:
1325                         mnt->options &= ~NFS_OPTION_MIGRATION;
1326                         break;
1327
1328                 /*
1329                  * options that take numeric values
1330                  */
1331                 case Opt_port:
1332                         if (nfs_get_option_ul(args, &option) ||
1333                             option > USHRT_MAX)
1334                                 goto out_invalid_value;
1335                         mnt->nfs_server.port = option;
1336                         break;
1337                 case Opt_rsize:
1338                         if (nfs_get_option_ul(args, &option))
1339                                 goto out_invalid_value;
1340                         mnt->rsize = option;
1341                         break;
1342                 case Opt_wsize:
1343                         if (nfs_get_option_ul(args, &option))
1344                                 goto out_invalid_value;
1345                         mnt->wsize = option;
1346                         break;
1347                 case Opt_bsize:
1348                         if (nfs_get_option_ul(args, &option))
1349                                 goto out_invalid_value;
1350                         mnt->bsize = option;
1351                         break;
1352                 case Opt_timeo:
1353                         if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1354                                 goto out_invalid_value;
1355                         mnt->timeo = option;
1356                         break;
1357                 case Opt_retrans:
1358                         if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1359                                 goto out_invalid_value;
1360                         mnt->retrans = option;
1361                         break;
1362                 case Opt_acregmin:
1363                         if (nfs_get_option_ul(args, &option))
1364                                 goto out_invalid_value;
1365                         mnt->acregmin = option;
1366                         break;
1367                 case Opt_acregmax:
1368                         if (nfs_get_option_ul(args, &option))
1369                                 goto out_invalid_value;
1370                         mnt->acregmax = option;
1371                         break;
1372                 case Opt_acdirmin:
1373                         if (nfs_get_option_ul(args, &option))
1374                                 goto out_invalid_value;
1375                         mnt->acdirmin = option;
1376                         break;
1377                 case Opt_acdirmax:
1378                         if (nfs_get_option_ul(args, &option))
1379                                 goto out_invalid_value;
1380                         mnt->acdirmax = option;
1381                         break;
1382                 case Opt_actimeo:
1383                         if (nfs_get_option_ul(args, &option))
1384                                 goto out_invalid_value;
1385                         mnt->acregmin = mnt->acregmax =
1386                         mnt->acdirmin = mnt->acdirmax = option;
1387                         break;
1388                 case Opt_namelen:
1389                         if (nfs_get_option_ul(args, &option))
1390                                 goto out_invalid_value;
1391                         mnt->namlen = option;
1392                         break;
1393                 case Opt_mountport:
1394                         if (nfs_get_option_ul(args, &option) ||
1395                             option > USHRT_MAX)
1396                                 goto out_invalid_value;
1397                         mnt->mount_server.port = option;
1398                         break;
1399                 case Opt_mountvers:
1400                         if (nfs_get_option_ul(args, &option) ||
1401                             option < NFS_MNT_VERSION ||
1402                             option > NFS_MNT3_VERSION)
1403                                 goto out_invalid_value;
1404                         mnt->mount_server.version = option;
1405                         break;
1406                 case Opt_minorversion:
1407                         if (nfs_get_option_ul(args, &option))
1408                                 goto out_invalid_value;
1409                         if (option > NFS4_MAX_MINOR_VERSION)
1410                                 goto out_invalid_value;
1411                         mnt->minorversion = option;
1412                         break;
1413
1414                 /*
1415                  * options that take text values
1416                  */
1417                 case Opt_nfsvers:
1418                         string = match_strdup(args);
1419                         if (string == NULL)
1420                                 goto out_nomem;
1421                         rc = nfs_parse_version_string(string, mnt, args);
1422                         kfree(string);
1423                         if (!rc)
1424                                 goto out_invalid_value;
1425                         break;
1426                 case Opt_sec:
1427                         string = match_strdup(args);
1428                         if (string == NULL)
1429                                 goto out_nomem;
1430                         rc = nfs_parse_security_flavors(string, mnt);
1431                         kfree(string);
1432                         if (!rc) {
1433                                 dfprintk(MOUNT, "NFS:   unrecognized "
1434                                                 "security flavor\n");
1435                                 return 0;
1436                         }
1437                         break;
1438                 case Opt_proto:
1439                         string = match_strdup(args);
1440                         if (string == NULL)
1441                                 goto out_nomem;
1442                         token = match_token(string,
1443                                             nfs_xprt_protocol_tokens, args);
1444
1445                         protofamily = AF_INET;
1446                         switch (token) {
1447                         case Opt_xprt_udp6:
1448                                 protofamily = AF_INET6;
1449                                 /* fall through */
1450                         case Opt_xprt_udp:
1451                                 mnt->flags &= ~NFS_MOUNT_TCP;
1452                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1453                                 break;
1454                         case Opt_xprt_tcp6:
1455                                 protofamily = AF_INET6;
1456                                 /* fall through */
1457                         case Opt_xprt_tcp:
1458                                 mnt->flags |= NFS_MOUNT_TCP;
1459                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1460                                 break;
1461                         case Opt_xprt_rdma6:
1462                                 protofamily = AF_INET6;
1463                                 /* fall through */
1464                         case Opt_xprt_rdma:
1465                                 /* vector side protocols to TCP */
1466                                 mnt->flags |= NFS_MOUNT_TCP;
1467                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1468                                 xprt_load_transport(string);
1469                                 break;
1470                         default:
1471                                 dfprintk(MOUNT, "NFS:   unrecognized "
1472                                                 "transport protocol\n");
1473                                 kfree(string);
1474                                 return 0;
1475                         }
1476                         kfree(string);
1477                         break;
1478                 case Opt_mountproto:
1479                         string = match_strdup(args);
1480                         if (string == NULL)
1481                                 goto out_nomem;
1482                         token = match_token(string,
1483                                             nfs_xprt_protocol_tokens, args);
1484                         kfree(string);
1485
1486                         mountfamily = AF_INET;
1487                         switch (token) {
1488                         case Opt_xprt_udp6:
1489                                 mountfamily = AF_INET6;
1490                                 /* fall through */
1491                         case Opt_xprt_udp:
1492                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1493                                 break;
1494                         case Opt_xprt_tcp6:
1495                                 mountfamily = AF_INET6;
1496                                 /* fall through */
1497                         case Opt_xprt_tcp:
1498                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1499                                 break;
1500                         case Opt_xprt_rdma: /* not used for side protocols */
1501                         default:
1502                                 dfprintk(MOUNT, "NFS:   unrecognized "
1503                                                 "transport protocol\n");
1504                                 return 0;
1505                         }
1506                         break;
1507                 case Opt_addr:
1508                         string = match_strdup(args);
1509                         if (string == NULL)
1510                                 goto out_nomem;
1511                         mnt->nfs_server.addrlen =
1512                                 rpc_pton(mnt->net, string, strlen(string),
1513                                         (struct sockaddr *)
1514                                         &mnt->nfs_server.address,
1515                                         sizeof(mnt->nfs_server.address));
1516                         kfree(string);
1517                         if (mnt->nfs_server.addrlen == 0)
1518                                 goto out_invalid_address;
1519                         break;
1520                 case Opt_clientaddr:
1521                         if (nfs_get_option_str(args, &mnt->client_address))
1522                                 goto out_nomem;
1523                         break;
1524                 case Opt_mounthost:
1525                         if (nfs_get_option_str(args,
1526                                                &mnt->mount_server.hostname))
1527                                 goto out_nomem;
1528                         break;
1529                 case Opt_mountaddr:
1530                         string = match_strdup(args);
1531                         if (string == NULL)
1532                                 goto out_nomem;
1533                         mnt->mount_server.addrlen =
1534                                 rpc_pton(mnt->net, string, strlen(string),
1535                                         (struct sockaddr *)
1536                                         &mnt->mount_server.address,
1537                                         sizeof(mnt->mount_server.address));
1538                         kfree(string);
1539                         if (mnt->mount_server.addrlen == 0)
1540                                 goto out_invalid_address;
1541                         break;
1542                 case Opt_lookupcache:
1543                         string = match_strdup(args);
1544                         if (string == NULL)
1545                                 goto out_nomem;
1546                         token = match_token(string,
1547                                         nfs_lookupcache_tokens, args);
1548                         kfree(string);
1549                         switch (token) {
1550                                 case Opt_lookupcache_all:
1551                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1552                                         break;
1553                                 case Opt_lookupcache_positive:
1554                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1555                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1556                                         break;
1557                                 case Opt_lookupcache_none:
1558                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1559                                         break;
1560                                 default:
1561                                         dfprintk(MOUNT, "NFS:   invalid "
1562                                                         "lookupcache argument\n");
1563                                         return 0;
1564                         };
1565                         break;
1566                 case Opt_fscache_uniq:
1567                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1568                                 goto out_nomem;
1569                         mnt->options |= NFS_OPTION_FSCACHE;
1570                         break;
1571                 case Opt_local_lock:
1572                         string = match_strdup(args);
1573                         if (string == NULL)
1574                                 goto out_nomem;
1575                         token = match_token(string, nfs_local_lock_tokens,
1576                                         args);
1577                         kfree(string);
1578                         switch (token) {
1579                         case Opt_local_lock_all:
1580                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1581                                                NFS_MOUNT_LOCAL_FCNTL);
1582                                 break;
1583                         case Opt_local_lock_flock:
1584                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1585                                 break;
1586                         case Opt_local_lock_posix:
1587                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1588                                 break;
1589                         case Opt_local_lock_none:
1590                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1591                                                 NFS_MOUNT_LOCAL_FCNTL);
1592                                 break;
1593                         default:
1594                                 dfprintk(MOUNT, "NFS:   invalid "
1595                                                 "local_lock argument\n");
1596                                 return 0;
1597                         };
1598                         break;
1599
1600                 /*
1601                  * Special options
1602                  */
1603                 case Opt_sloppy:
1604                         sloppy = 1;
1605                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1606                         break;
1607                 case Opt_userspace:
1608                 case Opt_deprecated:
1609                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1610                                         "'%s'\n", p);
1611                         break;
1612
1613                 default:
1614                         invalid_option = 1;
1615                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1616                                         "'%s'\n", p);
1617                 }
1618         }
1619
1620         if (!sloppy && invalid_option)
1621                 return 0;
1622
1623         if (mnt->minorversion && mnt->version != 4)
1624                 goto out_minorversion_mismatch;
1625
1626         if (mnt->options & NFS_OPTION_MIGRATION &&
1627             (mnt->version != 4 || mnt->minorversion != 0))
1628                 goto out_migration_misuse;
1629
1630         /*
1631          * verify that any proto=/mountproto= options match the address
1632          * families in the addr=/mountaddr= options.
1633          */
1634         if (protofamily != AF_UNSPEC &&
1635             protofamily != mnt->nfs_server.address.ss_family)
1636                 goto out_proto_mismatch;
1637
1638         if (mountfamily != AF_UNSPEC) {
1639                 if (mnt->mount_server.addrlen) {
1640                         if (mountfamily != mnt->mount_server.address.ss_family)
1641                                 goto out_mountproto_mismatch;
1642                 } else {
1643                         if (mountfamily != mnt->nfs_server.address.ss_family)
1644                                 goto out_mountproto_mismatch;
1645                 }
1646         }
1647
1648         return 1;
1649
1650 out_mountproto_mismatch:
1651         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1652                          "option\n");
1653         return 0;
1654 out_proto_mismatch:
1655         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1656         return 0;
1657 out_invalid_address:
1658         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1659         return 0;
1660 out_invalid_value:
1661         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1662         return 0;
1663 out_minorversion_mismatch:
1664         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1665                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1666         return 0;
1667 out_migration_misuse:
1668         printk(KERN_INFO
1669                 "NFS: 'migration' not supported for this NFS version\n");
1670         return 0;
1671 out_nomem:
1672         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1673         return 0;
1674 out_security_failure:
1675         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1676         return 0;
1677 }
1678
1679 /*
1680  * Ensure that a specified authtype in args->auth_info is supported by
1681  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1682  * -EACCES if not.
1683  */
1684 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1685                         rpc_authflavor_t *server_authlist, unsigned int count)
1686 {
1687         rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1688         bool found_auth_null = false;
1689         unsigned int i;
1690
1691         /*
1692          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1693          * must be in the list returned by the server.
1694          *
1695          * AUTH_NULL has a special meaning when it's in the server list - it
1696          * means that the server will ignore the rpc creds, so any flavor
1697          * can be used but still use the sec= that was specified.
1698          *
1699          * Note also that the MNT procedure in MNTv1 does not return a list
1700          * of supported security flavors. In this case, nfs_mount() fabricates
1701          * a security flavor list containing just AUTH_NULL.
1702          */
1703         for (i = 0; i < count; i++) {
1704                 flavor = server_authlist[i];
1705
1706                 if (nfs_auth_info_match(&args->auth_info, flavor))
1707                         goto out;
1708
1709                 if (flavor == RPC_AUTH_NULL)
1710                         found_auth_null = true;
1711         }
1712
1713         if (found_auth_null) {
1714                 flavor = args->auth_info.flavors[0];
1715                 goto out;
1716         }
1717
1718         dfprintk(MOUNT,
1719                  "NFS: specified auth flavors not supported by server\n");
1720         return -EACCES;
1721
1722 out:
1723         args->selected_flavor = flavor;
1724         dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1725         return 0;
1726 }
1727
1728 /*
1729  * Use the remote server's MOUNT service to request the NFS file handle
1730  * corresponding to the provided path.
1731  */
1732 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1733                              struct nfs_fh *root_fh,
1734                              rpc_authflavor_t *server_authlist,
1735                              unsigned int *server_authlist_len)
1736 {
1737         struct nfs_mount_request request = {
1738                 .sap            = (struct sockaddr *)
1739                                                 &args->mount_server.address,
1740                 .dirpath        = args->nfs_server.export_path,
1741                 .protocol       = args->mount_server.protocol,
1742                 .fh             = root_fh,
1743                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1744                 .auth_flav_len  = server_authlist_len,
1745                 .auth_flavs     = server_authlist,
1746                 .net            = args->net,
1747         };
1748         int status;
1749
1750         if (args->mount_server.version == 0) {
1751                 switch (args->version) {
1752                         default:
1753                                 args->mount_server.version = NFS_MNT3_VERSION;
1754                                 break;
1755                         case 2:
1756                                 args->mount_server.version = NFS_MNT_VERSION;
1757                 }
1758         }
1759         request.version = args->mount_server.version;
1760
1761         if (args->mount_server.hostname)
1762                 request.hostname = args->mount_server.hostname;
1763         else
1764                 request.hostname = args->nfs_server.hostname;
1765
1766         /*
1767          * Construct the mount server's address.
1768          */
1769         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1770                 memcpy(request.sap, &args->nfs_server.address,
1771                        args->nfs_server.addrlen);
1772                 args->mount_server.addrlen = args->nfs_server.addrlen;
1773         }
1774         request.salen = args->mount_server.addrlen;
1775         nfs_set_port(request.sap, &args->mount_server.port, 0);
1776
1777         /*
1778          * Now ask the mount server to map our export path
1779          * to a file handle.
1780          */
1781         status = nfs_mount(&request);
1782         if (status != 0) {
1783                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1784                                 request.hostname, status);
1785                 return status;
1786         }
1787
1788         return 0;
1789 }
1790
1791 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1792                                         struct nfs_subversion *nfs_mod)
1793 {
1794         int status;
1795         unsigned int i;
1796         bool tried_auth_unix = false;
1797         bool auth_null_in_list = false;
1798         struct nfs_server *server = ERR_PTR(-EACCES);
1799         struct nfs_parsed_mount_data *args = mount_info->parsed;
1800         rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1801         unsigned int authlist_len = ARRAY_SIZE(authlist);
1802
1803         status = nfs_request_mount(args, mount_info->mntfh, authlist,
1804                                         &authlist_len);
1805         if (status)
1806                 return ERR_PTR(status);
1807
1808         /*
1809          * Was a sec= authflavor specified in the options? First, verify
1810          * whether the server supports it, and then just try to use it if so.
1811          */
1812         if (args->auth_info.flavor_len > 0) {
1813                 status = nfs_verify_authflavors(args, authlist, authlist_len);
1814                 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1815                          args->selected_flavor);
1816                 if (status)
1817                         return ERR_PTR(status);
1818                 return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1819         }
1820
1821         /*
1822          * No sec= option was provided. RFC 2623, section 2.7 suggests we
1823          * SHOULD prefer the flavor listed first. However, some servers list
1824          * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1825          */
1826         for (i = 0; i < authlist_len; ++i) {
1827                 rpc_authflavor_t flavor;
1828                 struct rpcsec_gss_info info;
1829
1830                 flavor = authlist[i];
1831                 switch (flavor) {
1832                 case RPC_AUTH_UNIX:
1833                         tried_auth_unix = true;
1834                         break;
1835                 case RPC_AUTH_NULL:
1836                         auth_null_in_list = true;
1837                         continue;
1838                 default:
1839                         if (rpcauth_get_gssinfo(flavor, &info) != 0)
1840                                 continue;
1841                         /* Fallthrough */
1842                 }
1843                 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1844                 args->selected_flavor = flavor;
1845                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1846                 if (!IS_ERR(server))
1847                         return server;
1848         }
1849
1850         /*
1851          * Nothing we tried so far worked. At this point, give up if we've
1852          * already tried AUTH_UNIX or if the server's list doesn't contain
1853          * AUTH_NULL
1854          */
1855         if (tried_auth_unix || !auth_null_in_list)
1856                 return server;
1857
1858         /* Last chance! Try AUTH_UNIX */
1859         dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1860         args->selected_flavor = RPC_AUTH_UNIX;
1861         return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1862 }
1863
1864 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1865                              struct nfs_mount_info *mount_info,
1866                              struct nfs_subversion *nfs_mod)
1867 {
1868         struct nfs_server *server;
1869
1870         if (mount_info->parsed->need_mount)
1871                 server = nfs_try_mount_request(mount_info, nfs_mod);
1872         else
1873                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1874
1875         if (IS_ERR(server))
1876                 return ERR_CAST(server);
1877
1878         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1879 }
1880 EXPORT_SYMBOL_GPL(nfs_try_mount);
1881
1882 /*
1883  * Split "dev_name" into "hostname:export_path".
1884  *
1885  * The leftmost colon demarks the split between the server's hostname
1886  * and the export path.  If the hostname starts with a left square
1887  * bracket, then it may contain colons.
1888  *
1889  * Note: caller frees hostname and export path, even on error.
1890  */
1891 static int nfs_parse_devname(const char *dev_name,
1892                              char **hostname, size_t maxnamlen,
1893                              char **export_path, size_t maxpathlen)
1894 {
1895         size_t len;
1896         char *end;
1897
1898         /* Is the host name protected with square brakcets? */
1899         if (*dev_name == '[') {
1900                 end = strchr(++dev_name, ']');
1901                 if (end == NULL || end[1] != ':')
1902                         goto out_bad_devname;
1903
1904                 len = end - dev_name;
1905                 end++;
1906         } else {
1907                 char *comma;
1908
1909                 end = strchr(dev_name, ':');
1910                 if (end == NULL)
1911                         goto out_bad_devname;
1912                 len = end - dev_name;
1913
1914                 /* kill possible hostname list: not supported */
1915                 comma = strchr(dev_name, ',');
1916                 if (comma != NULL && comma < end)
1917                         *comma = 0;
1918         }
1919
1920         if (len > maxnamlen)
1921                 goto out_hostname;
1922
1923         /* N.B. caller will free nfs_server.hostname in all cases */
1924         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1925         if (*hostname == NULL)
1926                 goto out_nomem;
1927         len = strlen(++end);
1928         if (len > maxpathlen)
1929                 goto out_path;
1930         *export_path = kstrndup(end, len, GFP_KERNEL);
1931         if (!*export_path)
1932                 goto out_nomem;
1933
1934         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1935         return 0;
1936
1937 out_bad_devname:
1938         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1939         return -EINVAL;
1940
1941 out_nomem:
1942         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1943         return -ENOMEM;
1944
1945 out_hostname:
1946         dfprintk(MOUNT, "NFS: server hostname too long\n");
1947         return -ENAMETOOLONG;
1948
1949 out_path:
1950         dfprintk(MOUNT, "NFS: export pathname too long\n");
1951         return -ENAMETOOLONG;
1952 }
1953
1954 /*
1955  * Validate the NFS2/NFS3 mount data
1956  * - fills in the mount root filehandle
1957  *
1958  * For option strings, user space handles the following behaviors:
1959  *
1960  * + DNS: mapping server host name to IP address ("addr=" option)
1961  *
1962  * + failure mode: how to behave if a mount request can't be handled
1963  *   immediately ("fg/bg" option)
1964  *
1965  * + retry: how often to retry a mount request ("retry=" option)
1966  *
1967  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1968  *   mountproto=tcp after mountproto=udp, and so on
1969  */
1970 static int nfs23_validate_mount_data(void *options,
1971                                      struct nfs_parsed_mount_data *args,
1972                                      struct nfs_fh *mntfh,
1973                                      const char *dev_name)
1974 {
1975         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1976         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1977         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1978
1979         if (data == NULL)
1980                 goto out_no_data;
1981
1982         args->version = NFS_DEFAULT_VERSION;
1983         switch (data->version) {
1984         case 1:
1985                 data->namlen = 0; /* fall through */
1986         case 2:
1987                 data->bsize = 0; /* fall through */
1988         case 3:
1989                 if (data->flags & NFS_MOUNT_VER3)
1990                         goto out_no_v3;
1991                 data->root.size = NFS2_FHSIZE;
1992                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1993                 /* Turn off security negotiation */
1994                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
1995                 /* fall through */
1996         case 4:
1997                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1998                         goto out_no_sec;
1999                 /* fall through */
2000         case 5:
2001                 memset(data->context, 0, sizeof(data->context));
2002                 /* fall through */
2003         case 6:
2004                 if (data->flags & NFS_MOUNT_VER3) {
2005                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2006                                 goto out_invalid_fh;
2007                         mntfh->size = data->root.size;
2008                         args->version = 3;
2009                 } else {
2010                         mntfh->size = NFS2_FHSIZE;
2011                         args->version = 2;
2012                 }
2013
2014
2015                 memcpy(mntfh->data, data->root.data, mntfh->size);
2016                 if (mntfh->size < sizeof(mntfh->data))
2017                         memset(mntfh->data + mntfh->size, 0,
2018                                sizeof(mntfh->data) - mntfh->size);
2019
2020                 /*
2021                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
2022                  * can deal with.
2023                  */
2024                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
2025                 args->flags             |= extra_flags;
2026                 args->rsize             = data->rsize;
2027                 args->wsize             = data->wsize;
2028                 args->timeo             = data->timeo;
2029                 args->retrans           = data->retrans;
2030                 args->acregmin          = data->acregmin;
2031                 args->acregmax          = data->acregmax;
2032                 args->acdirmin          = data->acdirmin;
2033                 args->acdirmax          = data->acdirmax;
2034                 args->need_mount        = false;
2035
2036                 memcpy(sap, &data->addr, sizeof(data->addr));
2037                 args->nfs_server.addrlen = sizeof(data->addr);
2038                 args->nfs_server.port = ntohs(data->addr.sin_port);
2039                 if (!nfs_verify_server_address(sap))
2040                         goto out_no_address;
2041
2042                 if (!(data->flags & NFS_MOUNT_TCP))
2043                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2044                 /* N.B. caller will free nfs_server.hostname in all cases */
2045                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2046                 args->namlen            = data->namlen;
2047                 args->bsize             = data->bsize;
2048
2049                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2050                         args->selected_flavor = data->pseudoflavor;
2051                 else
2052                         args->selected_flavor = RPC_AUTH_UNIX;
2053                 if (!args->nfs_server.hostname)
2054                         goto out_nomem;
2055
2056                 if (!(data->flags & NFS_MOUNT_NONLM))
2057                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2058                                          NFS_MOUNT_LOCAL_FCNTL);
2059                 else
2060                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2061                                         NFS_MOUNT_LOCAL_FCNTL);
2062                 /*
2063                  * The legacy version 6 binary mount data from userspace has a
2064                  * field used only to transport selinux information into the
2065                  * the kernel.  To continue to support that functionality we
2066                  * have a touch of selinux knowledge here in the NFS code. The
2067                  * userspace code converted context=blah to just blah so we are
2068                  * converting back to the full string selinux understands.
2069                  */
2070                 if (data->context[0]){
2071 #ifdef CONFIG_SECURITY_SELINUX
2072                         int rc;
2073                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2074                         rc = security_add_mnt_opt("context", data->context,
2075                                         strlen(data->context), &args->lsm_opts);
2076                         if (rc)
2077                                 return rc;
2078 #else
2079                         return -EINVAL;
2080 #endif
2081                 }
2082
2083                 break;
2084         default:
2085                 return NFS_TEXT_DATA;
2086         }
2087
2088         return 0;
2089
2090 out_no_data:
2091         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2092         return -EINVAL;
2093
2094 out_no_v3:
2095         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2096                  data->version);
2097         return -EINVAL;
2098
2099 out_no_sec:
2100         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2101         return -EINVAL;
2102
2103 out_nomem:
2104         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2105         return -ENOMEM;
2106
2107 out_no_address:
2108         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2109         return -EINVAL;
2110
2111 out_invalid_fh:
2112         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2113         return -EINVAL;
2114 }
2115
2116 #if IS_ENABLED(CONFIG_NFS_V4)
2117 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2118                                    void *options,
2119                                    struct nfs_parsed_mount_data *args,
2120                                    struct nfs_fh *mntfh,
2121                                    const char *dev_name)
2122 {
2123         if (fs_type == &nfs_fs_type)
2124                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2125         return nfs4_validate_mount_data(options, args, dev_name);
2126 }
2127 #else
2128 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2129                                    void *options,
2130                                    struct nfs_parsed_mount_data *args,
2131                                    struct nfs_fh *mntfh,
2132                                    const char *dev_name)
2133 {
2134         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2135 }
2136 #endif
2137
2138 static int nfs_validate_text_mount_data(void *options,
2139                                         struct nfs_parsed_mount_data *args,
2140                                         const char *dev_name)
2141 {
2142         int port = 0;
2143         int max_namelen = PAGE_SIZE;
2144         int max_pathlen = NFS_MAXPATHLEN;
2145         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2146
2147         if (nfs_parse_mount_options((char *)options, args) == 0)
2148                 return -EINVAL;
2149
2150         if (!nfs_verify_server_address(sap))
2151                 goto out_no_address;
2152
2153         if (args->version == 4) {
2154 #if IS_ENABLED(CONFIG_NFS_V4)
2155                 if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2156                         port = NFS_RDMA_PORT;
2157                 else
2158                         port = NFS_PORT;
2159                 max_namelen = NFS4_MAXNAMLEN;
2160                 max_pathlen = NFS4_MAXPATHLEN;
2161                 nfs_validate_transport_protocol(args);
2162                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2163                         goto out_invalid_transport_udp;
2164                 nfs4_validate_mount_flags(args);
2165 #else
2166                 goto out_v4_not_compiled;
2167 #endif /* CONFIG_NFS_V4 */
2168         } else {
2169                 nfs_set_mount_transport_protocol(args);
2170                 if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2171                         port = NFS_RDMA_PORT;
2172         }
2173
2174         nfs_set_port(sap, &args->nfs_server.port, port);
2175
2176         return nfs_parse_devname(dev_name,
2177                                    &args->nfs_server.hostname,
2178                                    max_namelen,
2179                                    &args->nfs_server.export_path,
2180                                    max_pathlen);
2181
2182 #if !IS_ENABLED(CONFIG_NFS_V4)
2183 out_v4_not_compiled:
2184         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2185         return -EPROTONOSUPPORT;
2186 #else
2187 out_invalid_transport_udp:
2188         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2189         return -EINVAL;
2190 #endif /* !CONFIG_NFS_V4 */
2191
2192 out_no_address:
2193         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2194         return -EINVAL;
2195 }
2196
2197 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2198                 | NFS_MOUNT_SECURE \
2199                 | NFS_MOUNT_TCP \
2200                 | NFS_MOUNT_VER3 \
2201                 | NFS_MOUNT_KERBEROS \
2202                 | NFS_MOUNT_NONLM \
2203                 | NFS_MOUNT_BROKEN_SUID \
2204                 | NFS_MOUNT_STRICTLOCK \
2205                 | NFS_MOUNT_LEGACY_INTERFACE)
2206
2207 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2208                 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2209
2210 static int
2211 nfs_compare_remount_data(struct nfs_server *nfss,
2212                          struct nfs_parsed_mount_data *data)
2213 {
2214         if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2215             data->rsize != nfss->rsize ||
2216             data->wsize != nfss->wsize ||
2217             data->version != nfss->nfs_client->rpc_ops->version ||
2218             data->minorversion != nfss->nfs_client->cl_minorversion ||
2219             data->retrans != nfss->client->cl_timeout->to_retries ||
2220             !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2221             data->acregmin != nfss->acregmin / HZ ||
2222             data->acregmax != nfss->acregmax / HZ ||
2223             data->acdirmin != nfss->acdirmin / HZ ||
2224             data->acdirmax != nfss->acdirmax / HZ ||
2225             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2226             data->nfs_server.port != nfss->port ||
2227             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2228             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2229                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2230                 return -EINVAL;
2231
2232         return 0;
2233 }
2234
2235 int
2236 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2237 {
2238         int error;
2239         struct nfs_server *nfss = sb->s_fs_info;
2240         struct nfs_parsed_mount_data *data;
2241         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2242         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2243         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2244
2245         sync_filesystem(sb);
2246
2247         /*
2248          * Userspace mount programs that send binary options generally send
2249          * them populated with default values. We have no way to know which
2250          * ones were explicitly specified. Fall back to legacy behavior and
2251          * just return success.
2252          */
2253         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2254             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2255                                            options->version <= 6))))
2256                 return 0;
2257
2258         data = nfs_alloc_parsed_mount_data();
2259         if (data == NULL)
2260                 return -ENOMEM;
2261
2262         /* fill out struct with values from existing mount */
2263         data->flags = nfss->flags;
2264         data->rsize = nfss->rsize;
2265         data->wsize = nfss->wsize;
2266         data->retrans = nfss->client->cl_timeout->to_retries;
2267         data->selected_flavor = nfss->client->cl_auth->au_flavor;
2268         data->acregmin = nfss->acregmin / HZ;
2269         data->acregmax = nfss->acregmax / HZ;
2270         data->acdirmin = nfss->acdirmin / HZ;
2271         data->acdirmax = nfss->acdirmax / HZ;
2272         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2273         data->nfs_server.port = nfss->port;
2274         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2275         data->version = nfsvers;
2276         data->minorversion = nfss->nfs_client->cl_minorversion;
2277         data->net = current->nsproxy->net_ns;
2278         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2279                 data->nfs_server.addrlen);
2280
2281         /* overwrite those values with any that were specified */
2282         error = -EINVAL;
2283         if (!nfs_parse_mount_options((char *)options, data))
2284                 goto out;
2285
2286         /*
2287          * noac is a special case. It implies -o sync, but that's not
2288          * necessarily reflected in the mtab options. do_remount_sb
2289          * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2290          * remount options, so we have to explicitly reset it.
2291          */
2292         if (data->flags & NFS_MOUNT_NOAC)
2293                 *flags |= SB_SYNCHRONOUS;
2294
2295         /* compare new mount options with old ones */
2296         error = nfs_compare_remount_data(nfss, data);
2297         if (!error)
2298                 error = security_sb_remount(sb, data->lsm_opts);
2299 out:
2300         nfs_free_parsed_mount_data(data);
2301         return error;
2302 }
2303 EXPORT_SYMBOL_GPL(nfs_remount);
2304
2305 /*
2306  * Initialise the common bits of the superblock
2307  */
2308 static void nfs_initialise_sb(struct super_block *sb)
2309 {
2310         struct nfs_server *server = NFS_SB(sb);
2311
2312         sb->s_magic = NFS_SUPER_MAGIC;
2313
2314         /* We probably want something more informative here */
2315         snprintf(sb->s_id, sizeof(sb->s_id),
2316                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2317
2318         if (sb->s_blocksize == 0)
2319                 sb->s_blocksize = nfs_block_bits(server->wsize,
2320                                                  &sb->s_blocksize_bits);
2321
2322         nfs_super_set_maxbytes(sb, server->maxfilesize);
2323 }
2324
2325 /*
2326  * Finish setting up an NFS2/3 superblock
2327  */
2328 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2329 {
2330         struct nfs_parsed_mount_data *data = mount_info->parsed;
2331         struct nfs_server *server = NFS_SB(sb);
2332
2333         sb->s_blocksize_bits = 0;
2334         sb->s_blocksize = 0;
2335         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2336         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2337         if (data && data->bsize)
2338                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2339
2340         if (server->nfs_client->rpc_ops->version != 2) {
2341                 /* The VFS shouldn't apply the umask to mode bits. We will do
2342                  * so ourselves when necessary.
2343                  */
2344                 sb->s_flags |= SB_POSIXACL;
2345                 sb->s_time_gran = 1;
2346                 sb->s_export_op = &nfs_export_ops;
2347         }
2348
2349         nfs_initialise_sb(sb);
2350 }
2351 EXPORT_SYMBOL_GPL(nfs_fill_super);
2352
2353 /*
2354  * Finish setting up a cloned NFS2/3/4 superblock
2355  */
2356 static void nfs_clone_super(struct super_block *sb,
2357                             struct nfs_mount_info *mount_info)
2358 {
2359         const struct super_block *old_sb = mount_info->cloned->sb;
2360         struct nfs_server *server = NFS_SB(sb);
2361
2362         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2363         sb->s_blocksize = old_sb->s_blocksize;
2364         sb->s_maxbytes = old_sb->s_maxbytes;
2365         sb->s_xattr = old_sb->s_xattr;
2366         sb->s_op = old_sb->s_op;
2367         sb->s_time_gran = 1;
2368         sb->s_export_op = old_sb->s_export_op;
2369
2370         if (server->nfs_client->rpc_ops->version != 2) {
2371                 /* The VFS shouldn't apply the umask to mode bits. We will do
2372                  * so ourselves when necessary.
2373                  */
2374                 sb->s_flags |= SB_POSIXACL;
2375         }
2376
2377         nfs_initialise_sb(sb);
2378 }
2379
2380 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2381 {
2382         const struct nfs_server *a = s->s_fs_info;
2383         const struct rpc_clnt *clnt_a = a->client;
2384         const struct rpc_clnt *clnt_b = b->client;
2385
2386         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2387                 goto Ebusy;
2388         if (a->nfs_client != b->nfs_client)
2389                 goto Ebusy;
2390         if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2391                 goto Ebusy;
2392         if (a->wsize != b->wsize)
2393                 goto Ebusy;
2394         if (a->rsize != b->rsize)
2395                 goto Ebusy;
2396         if (a->acregmin != b->acregmin)
2397                 goto Ebusy;
2398         if (a->acregmax != b->acregmax)
2399                 goto Ebusy;
2400         if (a->acdirmin != b->acdirmin)
2401                 goto Ebusy;
2402         if (a->acdirmax != b->acdirmax)
2403                 goto Ebusy;
2404         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2405                 goto Ebusy;
2406         return 1;
2407 Ebusy:
2408         return 0;
2409 }
2410
2411 struct nfs_sb_mountdata {
2412         struct nfs_server *server;
2413         int mntflags;
2414 };
2415
2416 static int nfs_set_super(struct super_block *s, void *data)
2417 {
2418         struct nfs_sb_mountdata *sb_mntdata = data;
2419         struct nfs_server *server = sb_mntdata->server;
2420         int ret;
2421
2422         s->s_flags = sb_mntdata->mntflags;
2423         s->s_fs_info = server;
2424         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2425         ret = set_anon_super(s, server);
2426         if (ret == 0)
2427                 server->s_dev = s->s_dev;
2428         return ret;
2429 }
2430
2431 static int nfs_compare_super_address(struct nfs_server *server1,
2432                                      struct nfs_server *server2)
2433 {
2434         struct sockaddr *sap1, *sap2;
2435         struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2436         struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2437
2438         if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2439                 return 0;
2440
2441         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2442         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2443
2444         if (sap1->sa_family != sap2->sa_family)
2445                 return 0;
2446
2447         switch (sap1->sa_family) {
2448         case AF_INET: {
2449                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2450                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2451                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2452                         return 0;
2453                 if (sin1->sin_port != sin2->sin_port)
2454                         return 0;
2455                 break;
2456         }
2457         case AF_INET6: {
2458                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2459                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2460                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2461                         return 0;
2462                 if (sin1->sin6_port != sin2->sin6_port)
2463                         return 0;
2464                 break;
2465         }
2466         default:
2467                 return 0;
2468         }
2469
2470         return 1;
2471 }
2472
2473 static int nfs_compare_super(struct super_block *sb, void *data)
2474 {
2475         struct nfs_sb_mountdata *sb_mntdata = data;
2476         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2477         int mntflags = sb_mntdata->mntflags;
2478
2479         if (!nfs_compare_super_address(old, server))
2480                 return 0;
2481         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2482         if (old->flags & NFS_MOUNT_UNSHARED)
2483                 return 0;
2484         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2485                 return 0;
2486         return nfs_compare_mount_options(sb, server, mntflags);
2487 }
2488
2489 #ifdef CONFIG_NFS_FSCACHE
2490 static void nfs_get_cache_cookie(struct super_block *sb,
2491                                  struct nfs_parsed_mount_data *parsed,
2492                                  struct nfs_clone_mount *cloned)
2493 {
2494         struct nfs_server *nfss = NFS_SB(sb);
2495         char *uniq = NULL;
2496         int ulen = 0;
2497
2498         nfss->fscache_key = NULL;
2499         nfss->fscache = NULL;
2500
2501         if (parsed) {
2502                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2503                         return;
2504                 if (parsed->fscache_uniq) {
2505                         uniq = parsed->fscache_uniq;
2506                         ulen = strlen(parsed->fscache_uniq);
2507                 }
2508         } else if (cloned) {
2509                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2510                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2511                         return;
2512                 if (mnt_s->fscache_key) {
2513                         uniq = mnt_s->fscache_key->key.uniquifier;
2514                         ulen = mnt_s->fscache_key->key.uniq_len;
2515                 };
2516         } else
2517                 return;
2518
2519         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2520 }
2521 #else
2522 static void nfs_get_cache_cookie(struct super_block *sb,
2523                                  struct nfs_parsed_mount_data *parsed,
2524                                  struct nfs_clone_mount *cloned)
2525 {
2526 }
2527 #endif
2528
2529 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2530                         struct nfs_mount_info *mount_info)
2531 {
2532         int error;
2533         unsigned long kflags = 0, kflags_out = 0;
2534         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2535                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2536
2537         error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
2538                                                 kflags, &kflags_out);
2539         if (error)
2540                 goto err;
2541
2542         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2543                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2544                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2545 err:
2546         return error;
2547 }
2548 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2549
2550 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2551                           struct nfs_mount_info *mount_info)
2552 {
2553         int error;
2554         unsigned long kflags = 0, kflags_out = 0;
2555
2556         /* clone any lsm security options from the parent to the new sb */
2557         if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2558                 return -ESTALE;
2559
2560         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2561                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2562
2563         error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, kflags,
2564                         &kflags_out);
2565         if (error)
2566                 return error;
2567
2568         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2569                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2570                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2571         return 0;
2572 }
2573 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2574
2575 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2576                                    int flags, const char *dev_name,
2577                                    struct nfs_mount_info *mount_info,
2578                                    struct nfs_subversion *nfs_mod)
2579 {
2580         struct super_block *s;
2581         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2582         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2583         struct nfs_sb_mountdata sb_mntdata = {
2584                 .mntflags = flags,
2585                 .server = server,
2586         };
2587         int error;
2588
2589         if (server->flags & NFS_MOUNT_UNSHARED)
2590                 compare_super = NULL;
2591
2592         /* -o noac implies -o sync */
2593         if (server->flags & NFS_MOUNT_NOAC)
2594                 sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2595
2596         if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2597                 if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
2598                         sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2599
2600         /* Get a superblock - note that we may end up sharing one that already exists */
2601         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2602         if (IS_ERR(s)) {
2603                 mntroot = ERR_CAST(s);
2604                 goto out_err_nosb;
2605         }
2606
2607         if (s->s_fs_info != server) {
2608                 nfs_free_server(server);
2609                 server = NULL;
2610         } else {
2611                 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
2612                                              MINOR(server->s_dev));
2613                 if (error) {
2614                         mntroot = ERR_PTR(error);
2615                         goto error_splat_super;
2616                 }
2617                 s->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
2618                 server->super = s;
2619         }
2620
2621         if (!s->s_root) {
2622                 /* initial superblock/root creation */
2623                 mount_info->fill_super(s, mount_info);
2624                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2625                 if (!(server->flags & NFS_MOUNT_UNSHARED))
2626                         s->s_iflags |= SB_I_MULTIROOT;
2627         }
2628
2629         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2630         if (IS_ERR(mntroot))
2631                 goto error_splat_super;
2632
2633         error = mount_info->set_security(s, mntroot, mount_info);
2634         if (error)
2635                 goto error_splat_root;
2636
2637         s->s_flags |= SB_ACTIVE;
2638
2639 out:
2640         return mntroot;
2641
2642 out_err_nosb:
2643         nfs_free_server(server);
2644         goto out;
2645
2646 error_splat_root:
2647         dput(mntroot);
2648         mntroot = ERR_PTR(error);
2649 error_splat_super:
2650         deactivate_locked_super(s);
2651         goto out;
2652 }
2653 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2654
2655 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2656         int flags, const char *dev_name, void *raw_data)
2657 {
2658         struct nfs_mount_info mount_info = {
2659                 .fill_super = nfs_fill_super,
2660                 .set_security = nfs_set_sb_security,
2661         };
2662         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2663         struct nfs_subversion *nfs_mod;
2664         int error;
2665
2666         mount_info.parsed = nfs_alloc_parsed_mount_data();
2667         mount_info.mntfh = nfs_alloc_fhandle();
2668         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2669                 goto out;
2670
2671         /* Validate the mount data */
2672         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2673         if (error == NFS_TEXT_DATA)
2674                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2675         if (error < 0) {
2676                 mntroot = ERR_PTR(error);
2677                 goto out;
2678         }
2679
2680         nfs_mod = get_nfs_version(mount_info.parsed->version);
2681         if (IS_ERR(nfs_mod)) {
2682                 mntroot = ERR_CAST(nfs_mod);
2683                 goto out;
2684         }
2685
2686         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2687
2688         put_nfs_version(nfs_mod);
2689 out:
2690         nfs_free_parsed_mount_data(mount_info.parsed);
2691         nfs_free_fhandle(mount_info.mntfh);
2692         return mntroot;
2693 }
2694 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2695
2696 /*
2697  * Destroy an NFS2/3 superblock
2698  */
2699 void nfs_kill_super(struct super_block *s)
2700 {
2701         struct nfs_server *server = NFS_SB(s);
2702         dev_t dev = s->s_dev;
2703
2704         generic_shutdown_super(s);
2705
2706         nfs_fscache_release_super_cookie(s);
2707
2708         nfs_free_server(server);
2709         free_anon_bdev(dev);
2710 }
2711 EXPORT_SYMBOL_GPL(nfs_kill_super);
2712
2713 /*
2714  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2715  */
2716 static struct dentry *
2717 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2718                 const char *dev_name, void *raw_data)
2719 {
2720         struct nfs_clone_mount *data = raw_data;
2721         struct nfs_mount_info mount_info = {
2722                 .fill_super = nfs_clone_super,
2723                 .set_security = nfs_clone_sb_security,
2724                 .cloned = data,
2725         };
2726         struct nfs_server *server;
2727         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2728         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2729
2730         dprintk("--> nfs_xdev_mount()\n");
2731
2732         mount_info.mntfh = mount_info.cloned->fh;
2733
2734         /* create a new volume representation */
2735         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2736
2737         if (IS_ERR(server))
2738                 mntroot = ERR_CAST(server);
2739         else
2740                 mntroot = nfs_fs_mount_common(server, flags,
2741                                 dev_name, &mount_info, nfs_mod);
2742
2743         dprintk("<-- nfs_xdev_mount() = %ld\n",
2744                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2745         return mntroot;
2746 }
2747
2748 #if IS_ENABLED(CONFIG_NFS_V4)
2749
2750 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2751 {
2752         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2753                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2754 }
2755
2756 /*
2757  * Validate NFSv4 mount options
2758  */
2759 static int nfs4_validate_mount_data(void *options,
2760                                     struct nfs_parsed_mount_data *args,
2761                                     const char *dev_name)
2762 {
2763         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2764         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2765         char *c;
2766
2767         if (data == NULL)
2768                 goto out_no_data;
2769
2770         args->version = 4;
2771
2772         switch (data->version) {
2773         case 1:
2774                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2775                         goto out_no_address;
2776                 if (data->host_addrlen == 0)
2777                         goto out_no_address;
2778                 args->nfs_server.addrlen = data->host_addrlen;
2779                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2780                         return -EFAULT;
2781                 if (!nfs_verify_server_address(sap))
2782                         goto out_no_address;
2783                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2784
2785                 if (data->auth_flavourlen) {
2786                         rpc_authflavor_t pseudoflavor;
2787                         if (data->auth_flavourlen > 1)
2788                                 goto out_inval_auth;
2789                         if (copy_from_user(&pseudoflavor,
2790                                            data->auth_flavours,
2791                                            sizeof(pseudoflavor)))
2792                                 return -EFAULT;
2793                         args->selected_flavor = pseudoflavor;
2794                 } else
2795                         args->selected_flavor = RPC_AUTH_UNIX;
2796
2797                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2798                 if (IS_ERR(c))
2799                         return PTR_ERR(c);
2800                 args->nfs_server.hostname = c;
2801
2802                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2803                 if (IS_ERR(c))
2804                         return PTR_ERR(c);
2805                 args->nfs_server.export_path = c;
2806                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2807
2808                 c = strndup_user(data->client_addr.data, 16);
2809                 if (IS_ERR(c))
2810                         return PTR_ERR(c);
2811                 args->client_address = c;
2812
2813                 /*
2814                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2815                  * can deal with.
2816                  */
2817
2818                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2819                 args->rsize     = data->rsize;
2820                 args->wsize     = data->wsize;
2821                 args->timeo     = data->timeo;
2822                 args->retrans   = data->retrans;
2823                 args->acregmin  = data->acregmin;
2824                 args->acregmax  = data->acregmax;
2825                 args->acdirmin  = data->acdirmin;
2826                 args->acdirmax  = data->acdirmax;
2827                 args->nfs_server.protocol = data->proto;
2828                 nfs_validate_transport_protocol(args);
2829                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2830                         goto out_invalid_transport_udp;
2831
2832                 break;
2833         default:
2834                 return NFS_TEXT_DATA;
2835         }
2836
2837         return 0;
2838
2839 out_no_data:
2840         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2841         return -EINVAL;
2842
2843 out_inval_auth:
2844         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2845                  data->auth_flavourlen);
2846         return -EINVAL;
2847
2848 out_no_address:
2849         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2850         return -EINVAL;
2851
2852 out_invalid_transport_udp:
2853         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2854         return -EINVAL;
2855 }
2856
2857 /*
2858  * NFS v4 module parameters need to stay in the
2859  * NFS client for backwards compatibility
2860  */
2861 unsigned int nfs_callback_set_tcpport;
2862 unsigned short nfs_callback_nr_threads;
2863 /* Default cache timeout is 10 minutes */
2864 unsigned int nfs_idmap_cache_timeout = 600;
2865 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2866 bool nfs4_disable_idmapping = true;
2867 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2868 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
2869 unsigned short send_implementation_id = 1;
2870 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2871 bool recover_lost_locks = false;
2872
2873 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
2874 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2875 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2876 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2877 EXPORT_SYMBOL_GPL(max_session_slots);
2878 EXPORT_SYMBOL_GPL(max_session_cb_slots);
2879 EXPORT_SYMBOL_GPL(send_implementation_id);
2880 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2881 EXPORT_SYMBOL_GPL(recover_lost_locks);
2882
2883 #define NFS_CALLBACK_MAXPORTNR (65535U)
2884
2885 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2886 {
2887         unsigned long num;
2888         int ret;
2889
2890         if (!val)
2891                 return -EINVAL;
2892         ret = kstrtoul(val, 0, &num);
2893         if (ret || num > NFS_CALLBACK_MAXPORTNR)
2894                 return -EINVAL;
2895         *((unsigned int *)kp->arg) = num;
2896         return 0;
2897 }
2898 static const struct kernel_param_ops param_ops_portnr = {
2899         .set = param_set_portnr,
2900         .get = param_get_uint,
2901 };
2902 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2903
2904 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2905 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
2906 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
2907                 "assigned to the NFSv4 callback channels.");
2908 module_param(nfs_idmap_cache_timeout, int, 0644);
2909 module_param(nfs4_disable_idmapping, bool, 0644);
2910 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2911                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2912 MODULE_PARM_DESC(nfs4_disable_idmapping,
2913                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2914 module_param(max_session_slots, ushort, 0644);
2915 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2916                 "requests the client will negotiate");
2917 module_param(max_session_cb_slots, ushort, 0644);
2918 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
2919                 "callbacks the client will process for a given server");
2920 module_param(send_implementation_id, ushort, 0644);
2921 MODULE_PARM_DESC(send_implementation_id,
2922                 "Send implementation ID with NFSv4.1 exchange_id");
2923 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2924
2925 module_param(recover_lost_locks, bool, 0644);
2926 MODULE_PARM_DESC(recover_lost_locks,
2927                  "If the server reports that a lock might be lost, "
2928                  "try to recover it risking data corruption.");
2929
2930
2931 #endif /* CONFIG_NFS_V4 */