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 <asm/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
 535         seq_printf(m, ",mountproto=");
 536         switch (sap->sa_family) {
 537         case AF_INET:
 538                 switch (nfss->mountd_protocol) {
 539                 case IPPROTO_UDP:
 540                         seq_printf(m, RPCBIND_NETID_UDP);
 541                         break;
 542                 case IPPROTO_TCP:
 543                         seq_printf(m, RPCBIND_NETID_TCP);
 544                         break;
 545                 default:
 546                         if (showdefaults)
 547                                 seq_printf(m, "auto");
 548                 }
 549                 break;
 550         case AF_INET6:
 551                 switch (nfss->mountd_protocol) {
 552                 case IPPROTO_UDP:
 553                         seq_printf(m, RPCBIND_NETID_UDP6);
 554                         break;
 555                 case IPPROTO_TCP:
 556                         seq_printf(m, RPCBIND_NETID_TCP6);
 557                         break;
 558                 default:
 559                         if (showdefaults)
 560                                 seq_printf(m, "auto");
 561                 }
 562                 break;
 563         default:
 564                 if (showdefaults)
 565                         seq_printf(m, "auto");
 566         }
 567 }
 568
 569 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 570                                     int showdefaults)
 571 {
 572         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 573
 574         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 575                 return;
 576
 577         switch (sap->sa_family) {
 578         case AF_INET: {
 579                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 580                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 581                 break;
 582         }
 583         case AF_INET6: {
 584                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 585                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 586                 break;
 587         }
 588         default:
 589                 if (showdefaults)
 590                         seq_printf(m, ",mountaddr=unspecified");
 591         }
 592
 593         if (nfss->mountd_version || showdefaults)
 594                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 595         if ((nfss->mountd_port &&
 596                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 597                 showdefaults)
 598                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 599
 600         nfs_show_mountd_netid(m, nfss, showdefaults);
 601 }
 602
 603 #if IS_ENABLED(CONFIG_NFS_V4)
 604 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 605                                     int showdefaults)
 606 {
 607         struct nfs_client *clp = nfss->nfs_client;
 608
 609         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 610 }
 611 #else
 612 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 613                                     int showdefaults)
 614 {
 615 }
 616 #endif
 617
 618 static void nfs_show_nfs_version(struct seq_file *m,
 619                 unsigned int version,
 620                 unsigned int minorversion)
 621 {
 622         seq_printf(m, ",vers=%u", version);
 623         if (version == 4)
 624                 seq_printf(m, ".%u", minorversion);
 625 }
 626
 627 /*
 628  * Describe the mount options in force on this server representation
 629  */
 630 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 631                                    int showdefaults)
 632 {
 633         static const struct proc_nfs_info {
 634                 int flag;
 635                 const char *str;
 636                 const char *nostr;
 637         } nfs_info[] = {
 638                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 639                 { NFS_MOUNT_POSIX, ",posix", "" },
 640                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 641                 { NFS_MOUNT_NOAC, ",noac", "" },
 642                 { NFS_MOUNT_NONLM, ",nolock", "" },
 643                 { NFS_MOUNT_NOACL, ",noacl", "" },
 644                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 645                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 646                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 647                 { 0, NULL, NULL }
 648         };
 649         const struct proc_nfs_info *nfs_infop;
 650         struct nfs_client *clp = nfss->nfs_client;
 651         u32 version = clp->rpc_ops->version;
 652         int local_flock, local_fcntl;
 653
 654         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 655         seq_printf(m, ",rsize=%u", nfss->rsize);
 656         seq_printf(m, ",wsize=%u", nfss->wsize);
 657         if (nfss->bsize != 0)
 658                 seq_printf(m, ",bsize=%u", nfss->bsize);
 659         seq_printf(m, ",namlen=%u", nfss->namelen);
 660         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 661                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 662         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 663                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 664         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 665                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 666         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 667                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 668         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 669                 if (nfss->flags & nfs_infop->flag)
 670                         seq_puts(m, nfs_infop->str);
 671                 else
 672                         seq_puts(m, nfs_infop->nostr);
 673         }
 674         rcu_read_lock();
 675         seq_printf(m, ",proto=%s",
 676                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 677         rcu_read_unlock();
 678         if (version == 4) {
 679                 if (nfss->port != NFS_PORT)
 680                         seq_printf(m, ",port=%u", nfss->port);
 681         } else
 682                 if (nfss->port)
 683                         seq_printf(m, ",port=%u", nfss->port);
 684
 685         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 686         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 687         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 688
 689         if (version != 4)
 690                 nfs_show_mountd_options(m, nfss, showdefaults);
 691         else
 692                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 693
 694         if (nfss->options & NFS_OPTION_FSCACHE)
 695                 seq_printf(m, ",fsc");
 696
 697         if (nfss->options & NFS_OPTION_MIGRATION)
 698                 seq_printf(m, ",migration");
 699
 700         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 701                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 702                         seq_printf(m, ",lookupcache=none");
 703                 else
 704                         seq_printf(m, ",lookupcache=pos");
 705         }
 706
 707         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 708         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 709
 710         if (!local_flock && !local_fcntl)
 711                 seq_printf(m, ",local_lock=none");
 712         else if (local_flock && local_fcntl)
 713                 seq_printf(m, ",local_lock=all");
 714         else if (local_flock)
 715                 seq_printf(m, ",local_lock=flock");
 716         else
 717                 seq_printf(m, ",local_lock=posix");
 718 }
 719
 720 /*
 721  * Describe the mount options on this VFS mountpoint
 722  */
 723 int nfs_show_options(struct seq_file *m, struct dentry *root)
 724 {
 725         struct nfs_server *nfss = NFS_SB(root->d_sb);
 726
 727         nfs_show_mount_options(m, nfss, 0);
 728
 729         rcu_read_lock();
 730         seq_printf(m, ",addr=%s",
 731                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 732                                                         RPC_DISPLAY_ADDR));
 733         rcu_read_unlock();
 734
 735         return 0;
 736 }
 737 EXPORT_SYMBOL_GPL(nfs_show_options);
 738
 739 #if IS_ENABLED(CONFIG_NFS_V4)
 740 #ifdef CONFIG_NFS_V4_1
 741 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 742 {
 743         if (nfs4_has_session(server->nfs_client))
 744                 seq_printf(m, ",sessions");
 745 }
 746 #else
 747 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 748 #endif
 749 #endif
 750
 751 #ifdef CONFIG_NFS_V4_1
 752 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 753 {
 754         seq_printf(m, ",pnfs=");
 755         if (server->pnfs_curr_ld)
 756                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 757         else
 758                 seq_printf(m, "not configured");
 759 }
 760
 761 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 762 {
 763         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 764                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 765                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 766                            "date='%llu,%u'",
 767                            impl_id->name, impl_id->domain,
 768                            impl_id->date.seconds, impl_id->date.nseconds);
 769         }
 770 }
 771 #else
 772 #if IS_ENABLED(CONFIG_NFS_V4)
 773 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 774 {
 775 }
 776 #endif
 777 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 778 {
 779 }
 780 #endif
 781
 782 int nfs_show_devname(struct seq_file *m, struct dentry *root)
 783 {
 784         char *page = (char *) __get_free_page(GFP_KERNEL);
 785         char *devname, *dummy;
 786         int err = 0;
 787         if (!page)
 788                 return -ENOMEM;
 789         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
 790         if (IS_ERR(devname))
 791                 err = PTR_ERR(devname);
 792         else
 793                 seq_escape(m, devname, " \t\n\\");
 794         free_page((unsigned long)page);
 795         return err;
 796 }
 797 EXPORT_SYMBOL_GPL(nfs_show_devname);
 798
 799 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 800 {
 801         seq_puts(m, "/");
 802         return 0;
 803 }
 804 EXPORT_SYMBOL_GPL(nfs_show_path);
 805
 806 /*
 807  * Present statistical information for this VFS mountpoint
 808  */
 809 int nfs_show_stats(struct seq_file *m, struct dentry *root)
 810 {
 811         int i, cpu;
 812         struct nfs_server *nfss = NFS_SB(root->d_sb);
 813         struct rpc_auth *auth = nfss->client->cl_auth;
 814         struct nfs_iostats totals = { };
 815
 816         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 817
 818         /*
 819          * Display all mount option settings
 820          */
 821         seq_printf(m, "\n\topts:\t");
 822         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 823         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 824         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 825         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 826         nfs_show_mount_options(m, nfss, 1);
 827
 828         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 829
 830         show_implementation_id(m, nfss);
 831
 832         seq_printf(m, "\n\tcaps:\t");
 833         seq_printf(m, "caps=0x%x", nfss->caps);
 834         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 835         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 836         seq_printf(m, ",bsize=%u", nfss->bsize);
 837         seq_printf(m, ",namlen=%u", nfss->namelen);
 838
 839 #if IS_ENABLED(CONFIG_NFS_V4)
 840         if (nfss->nfs_client->rpc_ops->version == 4) {
 841                 seq_printf(m, "\n\tnfsv4:\t");
 842                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 843                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 844                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
 845                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 846                 show_sessions(m, nfss);
 847                 show_pnfs(m, nfss);
 848         }
 849 #endif
 850
 851         /*
 852          * Display security flavor in effect for this mount
 853          */
 854         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 855         if (auth->au_flavor)
 856                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 857
 858         /*
 859          * Display superblock I/O counters
 860          */
 861         for_each_possible_cpu(cpu) {
 862                 struct nfs_iostats *stats;
 863
 864                 preempt_disable();
 865                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 866
 867                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 868                         totals.events[i] += stats->events[i];
 869                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 870                         totals.bytes[i] += stats->bytes[i];
 871 #ifdef CONFIG_NFS_FSCACHE
 872                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 873                         totals.fscache[i] += stats->fscache[i];
 874 #endif
 875
 876                 preempt_enable();
 877         }
 878
 879         seq_printf(m, "\n\tevents:\t");
 880         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 881                 seq_printf(m, "%lu ", totals.events[i]);
 882         seq_printf(m, "\n\tbytes:\t");
 883         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 884                 seq_printf(m, "%Lu ", totals.bytes[i]);
 885 #ifdef CONFIG_NFS_FSCACHE
 886         if (nfss->options & NFS_OPTION_FSCACHE) {
 887                 seq_printf(m, "\n\tfsc:\t");
 888                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 889                         seq_printf(m, "%Lu ", totals.bytes[i]);
 890         }
 891 #endif
 892         seq_printf(m, "\n");
 893
 894         rpc_print_iostats(m, nfss->client);
 895
 896         return 0;
 897 }
 898 EXPORT_SYMBOL_GPL(nfs_show_stats);
 899
 900 /*
 901  * Begin unmount by attempting to remove all automounted mountpoints we added
 902  * in response to xdev traversals and referrals
 903  */
 904 void nfs_umount_begin(struct super_block *sb)
 905 {
 906         struct nfs_server *server;
 907         struct rpc_clnt *rpc;
 908
 909         server = NFS_SB(sb);
 910         /* -EIO all pending I/O */
 911         rpc = server->client_acl;
 912         if (!IS_ERR(rpc))
 913                 rpc_killall_tasks(rpc);
 914         rpc = server->client;
 915         if (!IS_ERR(rpc))
 916                 rpc_killall_tasks(rpc);
 917 }
 918 EXPORT_SYMBOL_GPL(nfs_umount_begin);
 919
 920 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 921 {
 922         struct nfs_parsed_mount_data *data;
 923
 924         data = kzalloc(sizeof(*data), GFP_KERNEL);
 925         if (data) {
 926                 data->acregmin          = NFS_DEF_ACREGMIN;
 927                 data->acregmax          = NFS_DEF_ACREGMAX;
 928                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 929                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 930                 data->mount_server.port = NFS_UNSPEC_PORT;
 931                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 932                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 933                 data->selected_flavor   = RPC_AUTH_MAXFLAVOR;
 934                 data->minorversion      = 0;
 935                 data->need_mount        = true;
 936                 data->net               = current->nsproxy->net_ns;
 937                 security_init_mnt_opts(&data->lsm_opts);
 938         }
 939         return data;
 940 }
 941
 942 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 943 {
 944         if (data) {
 945                 kfree(data->client_address);
 946                 kfree(data->mount_server.hostname);
 947                 kfree(data->nfs_server.export_path);
 948                 kfree(data->nfs_server.hostname);
 949                 kfree(data->fscache_uniq);
 950                 security_free_mnt_opts(&data->lsm_opts);
 951                 kfree(data);
 952         }
 953 }
 954
 955 /*
 956  * Sanity-check a server address provided by the mount command.
 957  *
 958  * Address family must be initialized, and address must not be
 959  * the ANY address for that family.
 960  */
 961 static int nfs_verify_server_address(struct sockaddr *addr)
 962 {
 963         switch (addr->sa_family) {
 964         case AF_INET: {
 965                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 966                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 967         }
 968         case AF_INET6: {
 969                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 970                 return !ipv6_addr_any(sa);
 971         }
 972         }
 973
 974         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 975         return 0;
 976 }
 977
 978 /*
 979  * Select between a default port value and a user-specified port value.
 980  * If a zero value is set, then autobind will be used.
 981  */
 982 static void nfs_set_port(struct sockaddr *sap, int *port,
 983                                  const unsigned short default_port)
 984 {
 985         if (*port == NFS_UNSPEC_PORT)
 986                 *port = default_port;
 987
 988         rpc_set_port(sap, *port);
 989 }
 990
 991 /*
 992  * Sanity check the NFS transport protocol.
 993  *
 994  */
 995 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 996 {
 997         switch (mnt->nfs_server.protocol) {
 998         case XPRT_TRANSPORT_UDP:
 999         case XPRT_TRANSPORT_TCP:
1000         case XPRT_TRANSPORT_RDMA:
1001                 break;
1002         default:
1003                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1004         }
1005 }
1006
1007 /*
1008  * For text based NFSv2/v3 mounts, the mount protocol transport default
1009  * settings should depend upon the specified NFS transport.
1010  */
1011 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1012 {
1013         nfs_validate_transport_protocol(mnt);
1014
1015         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1016             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1017                         return;
1018         switch (mnt->nfs_server.protocol) {
1019         case XPRT_TRANSPORT_UDP:
1020                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1021                 break;
1022         case XPRT_TRANSPORT_TCP:
1023         case XPRT_TRANSPORT_RDMA:
1024                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1025         }
1026 }
1027
1028 /*
1029  * Add 'flavor' to 'auth_info' if not already present.
1030  * Returns true if 'flavor' ends up in the list, false otherwise
1031  */
1032 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1033                               rpc_authflavor_t flavor)
1034 {
1035         unsigned int i;
1036         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1037
1038         /* make sure this flavor isn't already in the list */
1039         for (i = 0; i < auth_info->flavor_len; i++) {
1040                 if (flavor == auth_info->flavors[i])
1041                         return true;
1042         }
1043
1044         if (auth_info->flavor_len + 1 >= max_flavor_len) {
1045                 dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1046                 return false;
1047         }
1048
1049         auth_info->flavors[auth_info->flavor_len++] = flavor;
1050         return true;
1051 }
1052
1053 /*
1054  * Return true if 'match' is in auth_info or auth_info is empty.
1055  * Return false otherwise.
1056  */
1057 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1058                          rpc_authflavor_t match)
1059 {
1060         int i;
1061
1062         if (!auth_info->flavor_len)
1063                 return true;
1064
1065         for (i = 0; i < auth_info->flavor_len; i++) {
1066                 if (auth_info->flavors[i] == match)
1067                         return true;
1068         }
1069         return false;
1070 }
1071 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1072
1073 /*
1074  * Parse the value of the 'sec=' option.
1075  */
1076 static int nfs_parse_security_flavors(char *value,
1077                                       struct nfs_parsed_mount_data *mnt)
1078 {
1079         substring_t args[MAX_OPT_ARGS];
1080         rpc_authflavor_t pseudoflavor;
1081         char *p;
1082
1083         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1084
1085         while ((p = strsep(&value, ":")) != NULL) {
1086                 switch (match_token(p, nfs_secflavor_tokens, args)) {
1087                 case Opt_sec_none:
1088                         pseudoflavor = RPC_AUTH_NULL;
1089                         break;
1090                 case Opt_sec_sys:
1091                         pseudoflavor = RPC_AUTH_UNIX;
1092                         break;
1093                 case Opt_sec_krb5:
1094                         pseudoflavor = RPC_AUTH_GSS_KRB5;
1095                         break;
1096                 case Opt_sec_krb5i:
1097                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
1098                         break;
1099                 case Opt_sec_krb5p:
1100                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
1101                         break;
1102                 case Opt_sec_lkey:
1103                         pseudoflavor = RPC_AUTH_GSS_LKEY;
1104                         break;
1105                 case Opt_sec_lkeyi:
1106                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
1107                         break;
1108                 case Opt_sec_lkeyp:
1109                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
1110                         break;
1111                 case Opt_sec_spkm:
1112                         pseudoflavor = RPC_AUTH_GSS_SPKM;
1113                         break;
1114                 case Opt_sec_spkmi:
1115                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
1116                         break;
1117                 case Opt_sec_spkmp:
1118                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
1119                         break;
1120                 default:
1121                         dfprintk(MOUNT,
1122                                  "NFS: sec= option '%s' not recognized\n", p);
1123                         return 0;
1124                 }
1125
1126                 if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1127                         return 0;
1128         }
1129
1130         return 1;
1131 }
1132
1133 static int nfs_parse_version_string(char *string,
1134                 struct nfs_parsed_mount_data *mnt,
1135                 substring_t *args)
1136 {
1137         mnt->flags &= ~NFS_MOUNT_VER3;
1138         switch (match_token(string, nfs_vers_tokens, args)) {
1139         case Opt_vers_2:
1140                 mnt->version = 2;
1141                 break;
1142         case Opt_vers_3:
1143                 mnt->flags |= NFS_MOUNT_VER3;
1144                 mnt->version = 3;
1145                 break;
1146         case Opt_vers_4:
1147                 /* Backward compatibility option. In future,
1148                  * the mount program should always supply
1149                  * a NFSv4 minor version number.
1150                  */
1151                 mnt->version = 4;
1152                 break;
1153         case Opt_vers_4_0:
1154                 mnt->version = 4;
1155                 mnt->minorversion = 0;
1156                 break;
1157         case Opt_vers_4_1:
1158                 mnt->version = 4;
1159                 mnt->minorversion = 1;
1160                 break;
1161         case Opt_vers_4_2:
1162                 mnt->version = 4;
1163                 mnt->minorversion = 2;
1164                 break;
1165         default:
1166                 return 0;
1167         }
1168         return 1;
1169 }
1170
1171 static int nfs_get_option_str(substring_t args[], char **option)
1172 {
1173         kfree(*option);
1174         *option = match_strdup(args);
1175         return !*option;
1176 }
1177
1178 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1179 {
1180         int rc;
1181         char *string;
1182
1183         string = match_strdup(args);
1184         if (string == NULL)
1185                 return -ENOMEM;
1186         rc = kstrtoul(string, 10, option);
1187         kfree(string);
1188
1189         return rc;
1190 }
1191
1192 /*
1193  * Error-check and convert a string of mount options from user space into
1194  * a data structure.  The whole mount string is processed; bad options are
1195  * skipped as they are encountered.  If there were no errors, return 1;
1196  * otherwise return 0 (zero).
1197  */
1198 static int nfs_parse_mount_options(char *raw,
1199                                    struct nfs_parsed_mount_data *mnt)
1200 {
1201         char *p, *string, *secdata;
1202         int rc, sloppy = 0, invalid_option = 0;
1203         unsigned short protofamily = AF_UNSPEC;
1204         unsigned short mountfamily = AF_UNSPEC;
1205
1206         if (!raw) {
1207                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1208                 return 1;
1209         }
1210         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1211
1212         secdata = alloc_secdata();
1213         if (!secdata)
1214                 goto out_nomem;
1215
1216         rc = security_sb_copy_data(raw, secdata);
1217         if (rc)
1218                 goto out_security_failure;
1219
1220         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1221         if (rc)
1222                 goto out_security_failure;
1223
1224         free_secdata(secdata);
1225
1226         while ((p = strsep(&raw, ",")) != NULL) {
1227                 substring_t args[MAX_OPT_ARGS];
1228                 unsigned long option;
1229                 int token;
1230
1231                 if (!*p)
1232                         continue;
1233
1234                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1235
1236                 token = match_token(p, nfs_mount_option_tokens, args);
1237                 switch (token) {
1238
1239                 /*
1240                  * boolean options:  foo/nofoo
1241                  */
1242                 case Opt_soft:
1243                         mnt->flags |= NFS_MOUNT_SOFT;
1244                         break;
1245                 case Opt_hard:
1246                         mnt->flags &= ~NFS_MOUNT_SOFT;
1247                         break;
1248                 case Opt_posix:
1249                         mnt->flags |= NFS_MOUNT_POSIX;
1250                         break;
1251                 case Opt_noposix:
1252                         mnt->flags &= ~NFS_MOUNT_POSIX;
1253                         break;
1254                 case Opt_cto:
1255                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1256                         break;
1257                 case Opt_nocto:
1258                         mnt->flags |= NFS_MOUNT_NOCTO;
1259                         break;
1260                 case Opt_ac:
1261                         mnt->flags &= ~NFS_MOUNT_NOAC;
1262                         break;
1263                 case Opt_noac:
1264                         mnt->flags |= NFS_MOUNT_NOAC;
1265                         break;
1266                 case Opt_lock:
1267                         mnt->flags &= ~NFS_MOUNT_NONLM;
1268                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1269                                         NFS_MOUNT_LOCAL_FCNTL);
1270                         break;
1271                 case Opt_nolock:
1272                         mnt->flags |= NFS_MOUNT_NONLM;
1273                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1274                                        NFS_MOUNT_LOCAL_FCNTL);
1275                         break;
1276                 case Opt_udp:
1277                         mnt->flags &= ~NFS_MOUNT_TCP;
1278                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1279                         break;
1280                 case Opt_tcp:
1281                         mnt->flags |= NFS_MOUNT_TCP;
1282                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1283                         break;
1284                 case Opt_rdma:
1285                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1286                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1287                         xprt_load_transport(p);
1288                         break;
1289                 case Opt_acl:
1290                         mnt->flags &= ~NFS_MOUNT_NOACL;
1291                         break;
1292                 case Opt_noacl:
1293                         mnt->flags |= NFS_MOUNT_NOACL;
1294                         break;
1295                 case Opt_rdirplus:
1296                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1297                         break;
1298                 case Opt_nordirplus:
1299                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1300                         break;
1301                 case Opt_sharecache:
1302                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1303                         break;
1304                 case Opt_nosharecache:
1305                         mnt->flags |= NFS_MOUNT_UNSHARED;
1306                         break;
1307                 case Opt_resvport:
1308                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1309                         break;
1310                 case Opt_noresvport:
1311                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1312                         break;
1313                 case Opt_fscache:
1314                         mnt->options |= NFS_OPTION_FSCACHE;
1315                         kfree(mnt->fscache_uniq);
1316                         mnt->fscache_uniq = NULL;
1317                         break;
1318                 case Opt_nofscache:
1319                         mnt->options &= ~NFS_OPTION_FSCACHE;
1320                         kfree(mnt->fscache_uniq);
1321                         mnt->fscache_uniq = NULL;
1322                         break;
1323                 case Opt_migration:
1324                         mnt->options |= NFS_OPTION_MIGRATION;
1325                         break;
1326                 case Opt_nomigration:
1327                         mnt->options &= NFS_OPTION_MIGRATION;
1328                         break;
1329
1330                 /*
1331                  * options that take numeric values
1332                  */
1333                 case Opt_port:
1334                         if (nfs_get_option_ul(args, &option) ||
1335                             option > USHRT_MAX)
1336                                 goto out_invalid_value;
1337                         mnt->nfs_server.port = option;
1338                         break;
1339                 case Opt_rsize:
1340                         if (nfs_get_option_ul(args, &option))
1341                                 goto out_invalid_value;
1342                         mnt->rsize = option;
1343                         break;
1344                 case Opt_wsize:
1345                         if (nfs_get_option_ul(args, &option))
1346                                 goto out_invalid_value;
1347                         mnt->wsize = option;
1348                         break;
1349                 case Opt_bsize:
1350                         if (nfs_get_option_ul(args, &option))
1351                                 goto out_invalid_value;
1352                         mnt->bsize = option;
1353                         break;
1354                 case Opt_timeo:
1355                         if (nfs_get_option_ul(args, &option) || option == 0)
1356                                 goto out_invalid_value;
1357                         mnt->timeo = option;
1358                         break;
1359                 case Opt_retrans:
1360                         if (nfs_get_option_ul(args, &option) || option == 0)
1361                                 goto out_invalid_value;
1362                         mnt->retrans = option;
1363                         break;
1364                 case Opt_acregmin:
1365                         if (nfs_get_option_ul(args, &option))
1366                                 goto out_invalid_value;
1367                         mnt->acregmin = option;
1368                         break;
1369                 case Opt_acregmax:
1370                         if (nfs_get_option_ul(args, &option))
1371                                 goto out_invalid_value;
1372                         mnt->acregmax = option;
1373                         break;
1374                 case Opt_acdirmin:
1375                         if (nfs_get_option_ul(args, &option))
1376                                 goto out_invalid_value;
1377                         mnt->acdirmin = option;
1378                         break;
1379                 case Opt_acdirmax:
1380                         if (nfs_get_option_ul(args, &option))
1381                                 goto out_invalid_value;
1382                         mnt->acdirmax = option;
1383                         break;
1384                 case Opt_actimeo:
1385                         if (nfs_get_option_ul(args, &option))
1386                                 goto out_invalid_value;
1387                         mnt->acregmin = mnt->acregmax =
1388                         mnt->acdirmin = mnt->acdirmax = option;
1389                         break;
1390                 case Opt_namelen:
1391                         if (nfs_get_option_ul(args, &option))
1392                                 goto out_invalid_value;
1393                         mnt->namlen = option;
1394                         break;
1395                 case Opt_mountport:
1396                         if (nfs_get_option_ul(args, &option) ||
1397                             option > USHRT_MAX)
1398                                 goto out_invalid_value;
1399                         mnt->mount_server.port = option;
1400                         break;
1401                 case Opt_mountvers:
1402                         if (nfs_get_option_ul(args, &option) ||
1403                             option < NFS_MNT_VERSION ||
1404                             option > NFS_MNT3_VERSION)
1405                                 goto out_invalid_value;
1406                         mnt->mount_server.version = option;
1407                         break;
1408                 case Opt_minorversion:
1409                         if (nfs_get_option_ul(args, &option))
1410                                 goto out_invalid_value;
1411                         if (option > NFS4_MAX_MINOR_VERSION)
1412                                 goto out_invalid_value;
1413                         mnt->minorversion = option;
1414                         break;
1415
1416                 /*
1417                  * options that take text values
1418                  */
1419                 case Opt_nfsvers:
1420                         string = match_strdup(args);
1421                         if (string == NULL)
1422                                 goto out_nomem;
1423                         rc = nfs_parse_version_string(string, mnt, args);
1424                         kfree(string);
1425                         if (!rc)
1426                                 goto out_invalid_value;
1427                         break;
1428                 case Opt_sec:
1429                         string = match_strdup(args);
1430                         if (string == NULL)
1431                                 goto out_nomem;
1432                         rc = nfs_parse_security_flavors(string, mnt);
1433                         kfree(string);
1434                         if (!rc) {
1435                                 dfprintk(MOUNT, "NFS:   unrecognized "
1436                                                 "security flavor\n");
1437                                 return 0;
1438                         }
1439                         break;
1440                 case Opt_proto:
1441                         string = match_strdup(args);
1442                         if (string == NULL)
1443                                 goto out_nomem;
1444                         token = match_token(string,
1445                                             nfs_xprt_protocol_tokens, args);
1446
1447                         protofamily = AF_INET;
1448                         switch (token) {
1449                         case Opt_xprt_udp6:
1450                                 protofamily = AF_INET6;
1451                         case Opt_xprt_udp:
1452                                 mnt->flags &= ~NFS_MOUNT_TCP;
1453                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1454                                 break;
1455                         case Opt_xprt_tcp6:
1456                                 protofamily = AF_INET6;
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                         case Opt_xprt_rdma:
1464                                 /* vector side protocols to TCP */
1465                                 mnt->flags |= NFS_MOUNT_TCP;
1466                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1467                                 xprt_load_transport(string);
1468                                 break;
1469                         default:
1470                                 dfprintk(MOUNT, "NFS:   unrecognized "
1471                                                 "transport protocol\n");
1472                                 kfree(string);
1473                                 return 0;
1474                         }
1475                         kfree(string);
1476                         break;
1477                 case Opt_mountproto:
1478                         string = match_strdup(args);
1479                         if (string == NULL)
1480                                 goto out_nomem;
1481                         token = match_token(string,
1482                                             nfs_xprt_protocol_tokens, args);
1483                         kfree(string);
1484
1485                         mountfamily = AF_INET;
1486                         switch (token) {
1487                         case Opt_xprt_udp6:
1488                                 mountfamily = AF_INET6;
1489                         case Opt_xprt_udp:
1490                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1491                                 break;
1492                         case Opt_xprt_tcp6:
1493                                 mountfamily = AF_INET6;
1494                         case Opt_xprt_tcp:
1495                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1496                                 break;
1497                         case Opt_xprt_rdma: /* not used for side protocols */
1498                         default:
1499                                 dfprintk(MOUNT, "NFS:   unrecognized "
1500                                                 "transport protocol\n");
1501                                 return 0;
1502                         }
1503                         break;
1504                 case Opt_addr:
1505                         string = match_strdup(args);
1506                         if (string == NULL)
1507                                 goto out_nomem;
1508                         mnt->nfs_server.addrlen =
1509                                 rpc_pton(mnt->net, string, strlen(string),
1510                                         (struct sockaddr *)
1511                                         &mnt->nfs_server.address,
1512                                         sizeof(mnt->nfs_server.address));
1513                         kfree(string);
1514                         if (mnt->nfs_server.addrlen == 0)
1515                                 goto out_invalid_address;
1516                         break;
1517                 case Opt_clientaddr:
1518                         if (nfs_get_option_str(args, &mnt->client_address))
1519                                 goto out_nomem;
1520                         break;
1521                 case Opt_mounthost:
1522                         if (nfs_get_option_str(args,
1523                                                &mnt->mount_server.hostname))
1524                                 goto out_nomem;
1525                         break;
1526                 case Opt_mountaddr:
1527                         string = match_strdup(args);
1528                         if (string == NULL)
1529                                 goto out_nomem;
1530                         mnt->mount_server.addrlen =
1531                                 rpc_pton(mnt->net, string, strlen(string),
1532                                         (struct sockaddr *)
1533                                         &mnt->mount_server.address,
1534                                         sizeof(mnt->mount_server.address));
1535                         kfree(string);
1536                         if (mnt->mount_server.addrlen == 0)
1537                                 goto out_invalid_address;
1538                         break;
1539                 case Opt_lookupcache:
1540                         string = match_strdup(args);
1541                         if (string == NULL)
1542                                 goto out_nomem;
1543                         token = match_token(string,
1544                                         nfs_lookupcache_tokens, args);
1545                         kfree(string);
1546                         switch (token) {
1547                                 case Opt_lookupcache_all:
1548                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1549                                         break;
1550                                 case Opt_lookupcache_positive:
1551                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1552                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1553                                         break;
1554                                 case Opt_lookupcache_none:
1555                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1556                                         break;
1557                                 default:
1558                                         dfprintk(MOUNT, "NFS:   invalid "
1559                                                         "lookupcache argument\n");
1560                                         return 0;
1561                         };
1562                         break;
1563                 case Opt_fscache_uniq:
1564                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1565                                 goto out_nomem;
1566                         mnt->options |= NFS_OPTION_FSCACHE;
1567                         break;
1568                 case Opt_local_lock:
1569                         string = match_strdup(args);
1570                         if (string == NULL)
1571                                 goto out_nomem;
1572                         token = match_token(string, nfs_local_lock_tokens,
1573                                         args);
1574                         kfree(string);
1575                         switch (token) {
1576                         case Opt_local_lock_all:
1577                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1578                                                NFS_MOUNT_LOCAL_FCNTL);
1579                                 break;
1580                         case Opt_local_lock_flock:
1581                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1582                                 break;
1583                         case Opt_local_lock_posix:
1584                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1585                                 break;
1586                         case Opt_local_lock_none:
1587                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1588                                                 NFS_MOUNT_LOCAL_FCNTL);
1589                                 break;
1590                         default:
1591                                 dfprintk(MOUNT, "NFS:   invalid "
1592                                                 "local_lock argument\n");
1593                                 return 0;
1594                         };
1595                         break;
1596
1597                 /*
1598                  * Special options
1599                  */
1600                 case Opt_sloppy:
1601                         sloppy = 1;
1602                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1603                         break;
1604                 case Opt_userspace:
1605                 case Opt_deprecated:
1606                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1607                                         "'%s'\n", p);
1608                         break;
1609
1610                 default:
1611                         invalid_option = 1;
1612                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1613                                         "'%s'\n", p);
1614                 }
1615         }
1616
1617         if (!sloppy && invalid_option)
1618                 return 0;
1619
1620         if (mnt->minorversion && mnt->version != 4)
1621                 goto out_minorversion_mismatch;
1622
1623         if (mnt->options & NFS_OPTION_MIGRATION &&
1624             (mnt->version != 4 || mnt->minorversion != 0))
1625                 goto out_migration_misuse;
1626
1627         /*
1628          * verify that any proto=/mountproto= options match the address
1629          * families in the addr=/mountaddr= options.
1630          */
1631         if (protofamily != AF_UNSPEC &&
1632             protofamily != mnt->nfs_server.address.ss_family)
1633                 goto out_proto_mismatch;
1634
1635         if (mountfamily != AF_UNSPEC) {
1636                 if (mnt->mount_server.addrlen) {
1637                         if (mountfamily != mnt->mount_server.address.ss_family)
1638                                 goto out_mountproto_mismatch;
1639                 } else {
1640                         if (mountfamily != mnt->nfs_server.address.ss_family)
1641                                 goto out_mountproto_mismatch;
1642                 }
1643         }
1644
1645         return 1;
1646
1647 out_mountproto_mismatch:
1648         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1649                          "option\n");
1650         return 0;
1651 out_proto_mismatch:
1652         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1653         return 0;
1654 out_invalid_address:
1655         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1656         return 0;
1657 out_invalid_value:
1658         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1659         return 0;
1660 out_minorversion_mismatch:
1661         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1662                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1663         return 0;
1664 out_migration_misuse:
1665         printk(KERN_INFO
1666                 "NFS: 'migration' not supported for this NFS version\n");
1667         return 0;
1668 out_nomem:
1669         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1670         return 0;
1671 out_security_failure:
1672         free_secdata(secdata);
1673         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1674         return 0;
1675 }
1676
1677 /*
1678  * Ensure that a specified authtype in args->auth_info is supported by
1679  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1680  * -EACCES if not.
1681  */
1682 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1683                         rpc_authflavor_t *server_authlist, unsigned int count)
1684 {
1685         rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1686         unsigned int i;
1687
1688         /*
1689          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1690          * must be in the list returned by the server.
1691          *
1692          * AUTH_NULL has a special meaning when it's in the server list - it
1693          * means that the server will ignore the rpc creds, so any flavor
1694          * can be used.
1695          */
1696         for (i = 0; i < count; i++) {
1697                 flavor = server_authlist[i];
1698
1699                 if (nfs_auth_info_match(&args->auth_info, flavor) ||
1700                     flavor == RPC_AUTH_NULL)
1701                         goto out;
1702         }
1703
1704         dfprintk(MOUNT,
1705                  "NFS: specified auth flavors not supported by server\n");
1706         return -EACCES;
1707
1708 out:
1709         args->selected_flavor = flavor;
1710         dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1711         return 0;
1712 }
1713
1714 /*
1715  * Use the remote server's MOUNT service to request the NFS file handle
1716  * corresponding to the provided path.
1717  */
1718 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1719                              struct nfs_fh *root_fh,
1720                              rpc_authflavor_t *server_authlist,
1721                              unsigned int *server_authlist_len)
1722 {
1723         struct nfs_mount_request request = {
1724                 .sap            = (struct sockaddr *)
1725                                                 &args->mount_server.address,
1726                 .dirpath        = args->nfs_server.export_path,
1727                 .protocol       = args->mount_server.protocol,
1728                 .fh             = root_fh,
1729                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1730                 .auth_flav_len  = server_authlist_len,
1731                 .auth_flavs     = server_authlist,
1732                 .net            = args->net,
1733         };
1734         int status;
1735
1736         if (args->mount_server.version == 0) {
1737                 switch (args->version) {
1738                         default:
1739                                 args->mount_server.version = NFS_MNT3_VERSION;
1740                                 break;
1741                         case 2:
1742                                 args->mount_server.version = NFS_MNT_VERSION;
1743                 }
1744         }
1745         request.version = args->mount_server.version;
1746
1747         if (args->mount_server.hostname)
1748                 request.hostname = args->mount_server.hostname;
1749         else
1750                 request.hostname = args->nfs_server.hostname;
1751
1752         /*
1753          * Construct the mount server's address.
1754          */
1755         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1756                 memcpy(request.sap, &args->nfs_server.address,
1757                        args->nfs_server.addrlen);
1758                 args->mount_server.addrlen = args->nfs_server.addrlen;
1759         }
1760         request.salen = args->mount_server.addrlen;
1761         nfs_set_port(request.sap, &args->mount_server.port, 0);
1762
1763         /*
1764          * Now ask the mount server to map our export path
1765          * to a file handle.
1766          */
1767         status = nfs_mount(&request);
1768         if (status != 0) {
1769                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1770                                 request.hostname, status);
1771                 return status;
1772         }
1773
1774         return 0;
1775 }
1776
1777 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1778                                         struct nfs_subversion *nfs_mod)
1779 {
1780         int status;
1781         unsigned int i;
1782         bool tried_auth_unix = false;
1783         bool auth_null_in_list = false;
1784         struct nfs_server *server = ERR_PTR(-EACCES);
1785         struct nfs_parsed_mount_data *args = mount_info->parsed;
1786         rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1787         unsigned int authlist_len = ARRAY_SIZE(authlist);
1788
1789         status = nfs_request_mount(args, mount_info->mntfh, authlist,
1790                                         &authlist_len);
1791         if (status)
1792                 return ERR_PTR(status);
1793
1794         /*
1795          * Was a sec= authflavor specified in the options? First, verify
1796          * whether the server supports it, and then just try to use it if so.
1797          */
1798         if (args->auth_info.flavor_len > 0) {
1799                 status = nfs_verify_authflavors(args, authlist, authlist_len);
1800                 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1801                          args->selected_flavor);
1802                 if (status)
1803                         return ERR_PTR(status);
1804                 return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1805         }
1806
1807         /*
1808          * No sec= option was provided. RFC 2623, section 2.7 suggests we
1809          * SHOULD prefer the flavor listed first. However, some servers list
1810          * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1811          */
1812         for (i = 0; i < authlist_len; ++i) {
1813                 rpc_authflavor_t flavor;
1814                 struct rpcsec_gss_info info;
1815
1816                 flavor = authlist[i];
1817                 switch (flavor) {
1818                 case RPC_AUTH_UNIX:
1819                         tried_auth_unix = true;
1820                         break;
1821                 case RPC_AUTH_NULL:
1822                         auth_null_in_list = true;
1823                         continue;
1824                 default:
1825                         if (rpcauth_get_gssinfo(flavor, &info) != 0)
1826                                 continue;
1827                         /* Fallthrough */
1828                 }
1829                 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1830                 args->selected_flavor = flavor;
1831                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1832                 if (!IS_ERR(server))
1833                         return server;
1834         }
1835
1836         /*
1837          * Nothing we tried so far worked. At this point, give up if we've
1838          * already tried AUTH_UNIX or if the server's list doesn't contain
1839          * AUTH_NULL
1840          */
1841         if (tried_auth_unix || !auth_null_in_list)
1842                 return server;
1843
1844         /* Last chance! Try AUTH_UNIX */
1845         dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1846         args->selected_flavor = RPC_AUTH_UNIX;
1847         return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1848 }
1849
1850 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1851                              struct nfs_mount_info *mount_info,
1852                              struct nfs_subversion *nfs_mod)
1853 {
1854         struct nfs_server *server;
1855
1856         if (mount_info->parsed->need_mount)
1857                 server = nfs_try_mount_request(mount_info, nfs_mod);
1858         else
1859                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1860
1861         if (IS_ERR(server))
1862                 return ERR_CAST(server);
1863
1864         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1865 }
1866 EXPORT_SYMBOL_GPL(nfs_try_mount);
1867
1868 /*
1869  * Split "dev_name" into "hostname:export_path".
1870  *
1871  * The leftmost colon demarks the split between the server's hostname
1872  * and the export path.  If the hostname starts with a left square
1873  * bracket, then it may contain colons.
1874  *
1875  * Note: caller frees hostname and export path, even on error.
1876  */
1877 static int nfs_parse_devname(const char *dev_name,
1878                              char **hostname, size_t maxnamlen,
1879                              char **export_path, size_t maxpathlen)
1880 {
1881         size_t len;
1882         char *end;
1883
1884         /* Is the host name protected with square brakcets? */
1885         if (*dev_name == '[') {
1886                 end = strchr(++dev_name, ']');
1887                 if (end == NULL || end[1] != ':')
1888                         goto out_bad_devname;
1889
1890                 len = end - dev_name;
1891                 end++;
1892         } else {
1893                 char *comma;
1894
1895                 end = strchr(dev_name, ':');
1896                 if (end == NULL)
1897                         goto out_bad_devname;
1898                 len = end - dev_name;
1899
1900                 /* kill possible hostname list: not supported */
1901                 comma = strchr(dev_name, ',');
1902                 if (comma != NULL && comma < end)
1903                         *comma = 0;
1904         }
1905
1906         if (len > maxnamlen)
1907                 goto out_hostname;
1908
1909         /* N.B. caller will free nfs_server.hostname in all cases */
1910         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1911         if (*hostname == NULL)
1912                 goto out_nomem;
1913         len = strlen(++end);
1914         if (len > maxpathlen)
1915                 goto out_path;
1916         *export_path = kstrndup(end, len, GFP_KERNEL);
1917         if (!*export_path)
1918                 goto out_nomem;
1919
1920         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1921         return 0;
1922
1923 out_bad_devname:
1924         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1925         return -EINVAL;
1926
1927 out_nomem:
1928         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1929         return -ENOMEM;
1930
1931 out_hostname:
1932         dfprintk(MOUNT, "NFS: server hostname too long\n");
1933         return -ENAMETOOLONG;
1934
1935 out_path:
1936         dfprintk(MOUNT, "NFS: export pathname too long\n");
1937         return -ENAMETOOLONG;
1938 }
1939
1940 /*
1941  * Validate the NFS2/NFS3 mount data
1942  * - fills in the mount root filehandle
1943  *
1944  * For option strings, user space handles the following behaviors:
1945  *
1946  * + DNS: mapping server host name to IP address ("addr=" option)
1947  *
1948  * + failure mode: how to behave if a mount request can't be handled
1949  *   immediately ("fg/bg" option)
1950  *
1951  * + retry: how often to retry a mount request ("retry=" option)
1952  *
1953  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1954  *   mountproto=tcp after mountproto=udp, and so on
1955  */
1956 static int nfs23_validate_mount_data(void *options,
1957                                      struct nfs_parsed_mount_data *args,
1958                                      struct nfs_fh *mntfh,
1959                                      const char *dev_name)
1960 {
1961         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1962         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1963         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1964
1965         if (data == NULL)
1966                 goto out_no_data;
1967
1968         args->version = NFS_DEFAULT_VERSION;
1969         switch (data->version) {
1970         case 1:
1971                 data->namlen = 0;
1972         case 2:
1973                 data->bsize = 0;
1974         case 3:
1975                 if (data->flags & NFS_MOUNT_VER3)
1976                         goto out_no_v3;
1977                 data->root.size = NFS2_FHSIZE;
1978                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1979                 /* Turn off security negotiation */
1980                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
1981         case 4:
1982                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1983                         goto out_no_sec;
1984         case 5:
1985                 memset(data->context, 0, sizeof(data->context));
1986         case 6:
1987                 if (data->flags & NFS_MOUNT_VER3) {
1988                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1989                                 goto out_invalid_fh;
1990                         mntfh->size = data->root.size;
1991                         args->version = 3;
1992                 } else {
1993                         mntfh->size = NFS2_FHSIZE;
1994                         args->version = 2;
1995                 }
1996
1997
1998                 memcpy(mntfh->data, data->root.data, mntfh->size);
1999                 if (mntfh->size < sizeof(mntfh->data))
2000                         memset(mntfh->data + mntfh->size, 0,
2001                                sizeof(mntfh->data) - mntfh->size);
2002
2003                 /*
2004                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
2005                  * can deal with.
2006                  */
2007                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
2008                 args->flags             |= extra_flags;
2009                 args->rsize             = data->rsize;
2010                 args->wsize             = data->wsize;
2011                 args->timeo             = data->timeo;
2012                 args->retrans           = data->retrans;
2013                 args->acregmin          = data->acregmin;
2014                 args->acregmax          = data->acregmax;
2015                 args->acdirmin          = data->acdirmin;
2016                 args->acdirmax          = data->acdirmax;
2017                 args->need_mount        = false;
2018
2019                 memcpy(sap, &data->addr, sizeof(data->addr));
2020                 args->nfs_server.addrlen = sizeof(data->addr);
2021                 args->nfs_server.port = ntohs(data->addr.sin_port);
2022                 if (!nfs_verify_server_address(sap))
2023                         goto out_no_address;
2024
2025                 if (!(data->flags & NFS_MOUNT_TCP))
2026                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2027                 /* N.B. caller will free nfs_server.hostname in all cases */
2028                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2029                 args->namlen            = data->namlen;
2030                 args->bsize             = data->bsize;
2031
2032                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2033                         args->selected_flavor = data->pseudoflavor;
2034                 else
2035                         args->selected_flavor = RPC_AUTH_UNIX;
2036                 if (!args->nfs_server.hostname)
2037                         goto out_nomem;
2038
2039                 if (!(data->flags & NFS_MOUNT_NONLM))
2040                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2041                                          NFS_MOUNT_LOCAL_FCNTL);
2042                 else
2043                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2044                                         NFS_MOUNT_LOCAL_FCNTL);
2045                 /*
2046                  * The legacy version 6 binary mount data from userspace has a
2047                  * field used only to transport selinux information into the
2048                  * the kernel.  To continue to support that functionality we
2049                  * have a touch of selinux knowledge here in the NFS code. The
2050                  * userspace code converted context=blah to just blah so we are
2051                  * converting back to the full string selinux understands.
2052                  */
2053                 if (data->context[0]){
2054 #ifdef CONFIG_SECURITY_SELINUX
2055                         int rc;
2056                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2057                         if (!opts_str)
2058                                 return -ENOMEM;
2059                         strcpy(opts_str, "context=");
2060                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2061                         strcat(opts_str, &data->context[0]);
2062                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2063                         kfree(opts_str);
2064                         if (rc)
2065                                 return rc;
2066 #else
2067                         return -EINVAL;
2068 #endif
2069                 }
2070
2071                 break;
2072         default:
2073                 return NFS_TEXT_DATA;
2074         }
2075
2076         return 0;
2077
2078 out_no_data:
2079         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2080         return -EINVAL;
2081
2082 out_no_v3:
2083         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2084                  data->version);
2085         return -EINVAL;
2086
2087 out_no_sec:
2088         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2089         return -EINVAL;
2090
2091 out_nomem:
2092         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2093         return -ENOMEM;
2094
2095 out_no_address:
2096         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2097         return -EINVAL;
2098
2099 out_invalid_fh:
2100         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2101         return -EINVAL;
2102 }
2103
2104 #if IS_ENABLED(CONFIG_NFS_V4)
2105 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2106                                    void *options,
2107                                    struct nfs_parsed_mount_data *args,
2108                                    struct nfs_fh *mntfh,
2109                                    const char *dev_name)
2110 {
2111         if (fs_type == &nfs_fs_type)
2112                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2113         return nfs4_validate_mount_data(options, args, dev_name);
2114 }
2115 #else
2116 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2117                                    void *options,
2118                                    struct nfs_parsed_mount_data *args,
2119                                    struct nfs_fh *mntfh,
2120                                    const char *dev_name)
2121 {
2122         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2123 }
2124 #endif
2125
2126 static int nfs_validate_text_mount_data(void *options,
2127                                         struct nfs_parsed_mount_data *args,
2128                                         const char *dev_name)
2129 {
2130         int port = 0;
2131         int max_namelen = PAGE_SIZE;
2132         int max_pathlen = NFS_MAXPATHLEN;
2133         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2134
2135         if (nfs_parse_mount_options((char *)options, args) == 0)
2136                 return -EINVAL;
2137
2138         if (!nfs_verify_server_address(sap))
2139                 goto out_no_address;
2140
2141         if (args->version == 4) {
2142 #if IS_ENABLED(CONFIG_NFS_V4)
2143                 port = NFS_PORT;
2144                 max_namelen = NFS4_MAXNAMLEN;
2145                 max_pathlen = NFS4_MAXPATHLEN;
2146                 nfs_validate_transport_protocol(args);
2147                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2148                         goto out_invalid_transport_udp;
2149                 nfs4_validate_mount_flags(args);
2150 #else
2151                 goto out_v4_not_compiled;
2152 #endif /* CONFIG_NFS_V4 */
2153         } else
2154                 nfs_set_mount_transport_protocol(args);
2155
2156         nfs_set_port(sap, &args->nfs_server.port, port);
2157
2158         return nfs_parse_devname(dev_name,
2159                                    &args->nfs_server.hostname,
2160                                    max_namelen,
2161                                    &args->nfs_server.export_path,
2162                                    max_pathlen);
2163
2164 #if !IS_ENABLED(CONFIG_NFS_V4)
2165 out_v4_not_compiled:
2166         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2167         return -EPROTONOSUPPORT;
2168 #else
2169 out_invalid_transport_udp:
2170         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2171         return -EINVAL;
2172 #endif /* !CONFIG_NFS_V4 */
2173
2174 out_no_address:
2175         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2176         return -EINVAL;
2177 }
2178
2179 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2180                 | NFS_MOUNT_SECURE \
2181                 | NFS_MOUNT_TCP \
2182                 | NFS_MOUNT_VER3 \
2183                 | NFS_MOUNT_KERBEROS \
2184                 | NFS_MOUNT_NONLM \
2185                 | NFS_MOUNT_BROKEN_SUID \
2186                 | NFS_MOUNT_STRICTLOCK \
2187                 | NFS_MOUNT_LEGACY_INTERFACE)
2188
2189 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2190                 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2191
2192 static int
2193 nfs_compare_remount_data(struct nfs_server *nfss,
2194                          struct nfs_parsed_mount_data *data)
2195 {
2196         if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2197             data->rsize != nfss->rsize ||
2198             data->wsize != nfss->wsize ||
2199             data->version != nfss->nfs_client->rpc_ops->version ||
2200             data->minorversion != nfss->nfs_client->cl_minorversion ||
2201             data->retrans != nfss->client->cl_timeout->to_retries ||
2202             !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2203             data->acregmin != nfss->acregmin / HZ ||
2204             data->acregmax != nfss->acregmax / HZ ||
2205             data->acdirmin != nfss->acdirmin / HZ ||
2206             data->acdirmax != nfss->acdirmax / HZ ||
2207             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2208             data->nfs_server.port != nfss->port ||
2209             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2210             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2211                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2212                 return -EINVAL;
2213
2214         return 0;
2215 }
2216
2217 int
2218 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2219 {
2220         int error;
2221         struct nfs_server *nfss = sb->s_fs_info;
2222         struct nfs_parsed_mount_data *data;
2223         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2224         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2225         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2226
2227         sync_filesystem(sb);
2228
2229         /*
2230          * Userspace mount programs that send binary options generally send
2231          * them populated with default values. We have no way to know which
2232          * ones were explicitly specified. Fall back to legacy behavior and
2233          * just return success.
2234          */
2235         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2236             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2237                                            options->version <= 6))))
2238                 return 0;
2239
2240         data = kzalloc(sizeof(*data), GFP_KERNEL);
2241         if (data == NULL)
2242                 return -ENOMEM;
2243
2244         /* fill out struct with values from existing mount */
2245         data->flags = nfss->flags;
2246         data->rsize = nfss->rsize;
2247         data->wsize = nfss->wsize;
2248         data->retrans = nfss->client->cl_timeout->to_retries;
2249         data->selected_flavor = nfss->client->cl_auth->au_flavor;
2250         data->acregmin = nfss->acregmin / HZ;
2251         data->acregmax = nfss->acregmax / HZ;
2252         data->acdirmin = nfss->acdirmin / HZ;
2253         data->acdirmax = nfss->acdirmax / HZ;
2254         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2255         data->nfs_server.port = nfss->port;
2256         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2257         data->version = nfsvers;
2258         data->minorversion = nfss->nfs_client->cl_minorversion;
2259         data->net = current->nsproxy->net_ns;
2260         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2261                 data->nfs_server.addrlen);
2262
2263         /* overwrite those values with any that were specified */
2264         error = -EINVAL;
2265         if (!nfs_parse_mount_options((char *)options, data))
2266                 goto out;
2267
2268         /*
2269          * noac is a special case. It implies -o sync, but that's not
2270          * necessarily reflected in the mtab options. do_remount_sb
2271          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2272          * remount options, so we have to explicitly reset it.
2273          */
2274         if (data->flags & NFS_MOUNT_NOAC)
2275                 *flags |= MS_SYNCHRONOUS;
2276
2277         /* compare new mount options with old ones */
2278         error = nfs_compare_remount_data(nfss, data);
2279 out:
2280         kfree(data);
2281         return error;
2282 }
2283 EXPORT_SYMBOL_GPL(nfs_remount);
2284
2285 /*
2286  * Initialise the common bits of the superblock
2287  */
2288 inline void nfs_initialise_sb(struct super_block *sb)
2289 {
2290         struct nfs_server *server = NFS_SB(sb);
2291
2292         sb->s_magic = NFS_SUPER_MAGIC;
2293
2294         /* We probably want something more informative here */
2295         snprintf(sb->s_id, sizeof(sb->s_id),
2296                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2297
2298         if (sb->s_blocksize == 0)
2299                 sb->s_blocksize = nfs_block_bits(server->wsize,
2300                                                  &sb->s_blocksize_bits);
2301
2302         sb->s_bdi = &server->backing_dev_info;
2303
2304         nfs_super_set_maxbytes(sb, server->maxfilesize);
2305 }
2306
2307 /*
2308  * Finish setting up an NFS2/3 superblock
2309  */
2310 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2311 {
2312         struct nfs_parsed_mount_data *data = mount_info->parsed;
2313         struct nfs_server *server = NFS_SB(sb);
2314
2315         sb->s_blocksize_bits = 0;
2316         sb->s_blocksize = 0;
2317         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2318         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2319         if (data && data->bsize)
2320                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2321
2322         if (server->nfs_client->rpc_ops->version != 2) {
2323                 /* The VFS shouldn't apply the umask to mode bits. We will do
2324                  * so ourselves when necessary.
2325                  */
2326                 sb->s_flags |= MS_POSIXACL;
2327                 sb->s_time_gran = 1;
2328         }
2329
2330         nfs_initialise_sb(sb);
2331 }
2332 EXPORT_SYMBOL_GPL(nfs_fill_super);
2333
2334 /*
2335  * Finish setting up a cloned NFS2/3/4 superblock
2336  */
2337 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2338 {
2339         const struct super_block *old_sb = mount_info->cloned->sb;
2340         struct nfs_server *server = NFS_SB(sb);
2341
2342         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2343         sb->s_blocksize = old_sb->s_blocksize;
2344         sb->s_maxbytes = old_sb->s_maxbytes;
2345         sb->s_xattr = old_sb->s_xattr;
2346         sb->s_op = old_sb->s_op;
2347         sb->s_time_gran = 1;
2348
2349         if (server->nfs_client->rpc_ops->version != 2) {
2350                 /* The VFS shouldn't apply the umask to mode bits. We will do
2351                  * so ourselves when necessary.
2352                  */
2353                 sb->s_flags |= MS_POSIXACL;
2354         }
2355
2356         nfs_initialise_sb(sb);
2357 }
2358
2359 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2360 {
2361         const struct nfs_server *a = s->s_fs_info;
2362         const struct rpc_clnt *clnt_a = a->client;
2363         const struct rpc_clnt *clnt_b = b->client;
2364
2365         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2366                 goto Ebusy;
2367         if (a->nfs_client != b->nfs_client)
2368                 goto Ebusy;
2369         if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2370                 goto Ebusy;
2371         if (a->wsize != b->wsize)
2372                 goto Ebusy;
2373         if (a->rsize != b->rsize)
2374                 goto Ebusy;
2375         if (a->acregmin != b->acregmin)
2376                 goto Ebusy;
2377         if (a->acregmax != b->acregmax)
2378                 goto Ebusy;
2379         if (a->acdirmin != b->acdirmin)
2380                 goto Ebusy;
2381         if (a->acdirmax != b->acdirmax)
2382                 goto Ebusy;
2383         if (b->auth_info.flavor_len > 0 &&
2384            clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2385                 goto Ebusy;
2386         return 1;
2387 Ebusy:
2388         return 0;
2389 }
2390
2391 struct nfs_sb_mountdata {
2392         struct nfs_server *server;
2393         int mntflags;
2394 };
2395
2396 static int nfs_set_super(struct super_block *s, void *data)
2397 {
2398         struct nfs_sb_mountdata *sb_mntdata = data;
2399         struct nfs_server *server = sb_mntdata->server;
2400         int ret;
2401
2402         s->s_flags = sb_mntdata->mntflags;
2403         s->s_fs_info = server;
2404         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2405         ret = set_anon_super(s, server);
2406         if (ret == 0)
2407                 server->s_dev = s->s_dev;
2408         return ret;
2409 }
2410
2411 static int nfs_compare_super_address(struct nfs_server *server1,
2412                                      struct nfs_server *server2)
2413 {
2414         struct sockaddr *sap1, *sap2;
2415         struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2416         struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2417
2418         if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2419                 return 0;
2420
2421         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2422         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2423
2424         if (sap1->sa_family != sap2->sa_family)
2425                 return 0;
2426
2427         switch (sap1->sa_family) {
2428         case AF_INET: {
2429                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2430                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2431                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2432                         return 0;
2433                 if (sin1->sin_port != sin2->sin_port)
2434                         return 0;
2435                 break;
2436         }
2437         case AF_INET6: {
2438                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2439                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2440                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2441                         return 0;
2442                 if (sin1->sin6_port != sin2->sin6_port)
2443                         return 0;
2444                 break;
2445         }
2446         default:
2447                 return 0;
2448         }
2449
2450         return 1;
2451 }
2452
2453 static int nfs_compare_super(struct super_block *sb, void *data)
2454 {
2455         struct nfs_sb_mountdata *sb_mntdata = data;
2456         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2457         int mntflags = sb_mntdata->mntflags;
2458
2459         if (!nfs_compare_super_address(old, server))
2460                 return 0;
2461         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2462         if (old->flags & NFS_MOUNT_UNSHARED)
2463                 return 0;
2464         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2465                 return 0;
2466         return nfs_compare_mount_options(sb, server, mntflags);
2467 }
2468
2469 #ifdef CONFIG_NFS_FSCACHE
2470 static void nfs_get_cache_cookie(struct super_block *sb,
2471                                  struct nfs_parsed_mount_data *parsed,
2472                                  struct nfs_clone_mount *cloned)
2473 {
2474         struct nfs_server *nfss = NFS_SB(sb);
2475         char *uniq = NULL;
2476         int ulen = 0;
2477
2478         nfss->fscache_key = NULL;
2479         nfss->fscache = NULL;
2480
2481         if (parsed) {
2482                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2483                         return;
2484                 if (parsed->fscache_uniq) {
2485                         uniq = parsed->fscache_uniq;
2486                         ulen = strlen(parsed->fscache_uniq);
2487                 }
2488         } else if (cloned) {
2489                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2490                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2491                         return;
2492                 if (mnt_s->fscache_key) {
2493                         uniq = mnt_s->fscache_key->key.uniquifier;
2494                         ulen = mnt_s->fscache_key->key.uniq_len;
2495                 };
2496         } else
2497                 return;
2498
2499         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2500 }
2501 #else
2502 static void nfs_get_cache_cookie(struct super_block *sb,
2503                                  struct nfs_parsed_mount_data *parsed,
2504                                  struct nfs_clone_mount *cloned)
2505 {
2506 }
2507 #endif
2508
2509 static int nfs_bdi_register(struct nfs_server *server)
2510 {
2511         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2512 }
2513
2514 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2515                         struct nfs_mount_info *mount_info)
2516 {
2517         int error;
2518         unsigned long kflags = 0, kflags_out = 0;
2519         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2520                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2521
2522         error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2523                                                 kflags, &kflags_out);
2524         if (error)
2525                 goto err;
2526
2527         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2528                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2529                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2530 err:
2531         return error;
2532 }
2533 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2534
2535 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2536                           struct nfs_mount_info *mount_info)
2537 {
2538         /* clone any lsm security options from the parent to the new sb */
2539         if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2540                 return -ESTALE;
2541         return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2542 }
2543 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2544
2545 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2546                                    int flags, const char *dev_name,
2547                                    struct nfs_mount_info *mount_info,
2548                                    struct nfs_subversion *nfs_mod)
2549 {
2550         struct super_block *s;
2551         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2552         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2553         struct nfs_sb_mountdata sb_mntdata = {
2554                 .mntflags = flags,
2555                 .server = server,
2556         };
2557         int error;
2558
2559         if (server->flags & NFS_MOUNT_UNSHARED)
2560                 compare_super = NULL;
2561
2562         /* -o noac implies -o sync */
2563         if (server->flags & NFS_MOUNT_NOAC)
2564                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2565
2566         if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2567                 if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2568                         sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2569
2570         /* Get a superblock - note that we may end up sharing one that already exists */
2571         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2572         if (IS_ERR(s)) {
2573                 mntroot = ERR_CAST(s);
2574                 goto out_err_nosb;
2575         }
2576
2577         if (s->s_fs_info != server) {
2578                 nfs_free_server(server);
2579                 server = NULL;
2580         } else {
2581                 error = nfs_bdi_register(server);
2582                 if (error) {
2583                         mntroot = ERR_PTR(error);
2584                         goto error_splat_super;
2585                 }
2586                 server->super = s;
2587         }
2588
2589         if (!s->s_root) {
2590                 /* initial superblock/root creation */
2591                 mount_info->fill_super(s, mount_info);
2592                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2593         }
2594
2595         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2596         if (IS_ERR(mntroot))
2597                 goto error_splat_super;
2598
2599         error = mount_info->set_security(s, mntroot, mount_info);
2600         if (error)
2601                 goto error_splat_root;
2602
2603         s->s_flags |= MS_ACTIVE;
2604
2605 out:
2606         return mntroot;
2607
2608 out_err_nosb:
2609         nfs_free_server(server);
2610         goto out;
2611
2612 error_splat_root:
2613         dput(mntroot);
2614         mntroot = ERR_PTR(error);
2615 error_splat_super:
2616         deactivate_locked_super(s);
2617         goto out;
2618 }
2619 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2620
2621 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2622         int flags, const char *dev_name, void *raw_data)
2623 {
2624         struct nfs_mount_info mount_info = {
2625                 .fill_super = nfs_fill_super,
2626                 .set_security = nfs_set_sb_security,
2627         };
2628         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2629         struct nfs_subversion *nfs_mod;
2630         int error;
2631
2632         mount_info.parsed = nfs_alloc_parsed_mount_data();
2633         mount_info.mntfh = nfs_alloc_fhandle();
2634         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2635                 goto out;
2636
2637         /* Validate the mount data */
2638         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2639         if (error == NFS_TEXT_DATA)
2640                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2641         if (error < 0) {
2642                 mntroot = ERR_PTR(error);
2643                 goto out;
2644         }
2645
2646         nfs_mod = get_nfs_version(mount_info.parsed->version);
2647         if (IS_ERR(nfs_mod)) {
2648                 mntroot = ERR_CAST(nfs_mod);
2649                 goto out;
2650         }
2651
2652         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2653
2654         put_nfs_version(nfs_mod);
2655 out:
2656         nfs_free_parsed_mount_data(mount_info.parsed);
2657         nfs_free_fhandle(mount_info.mntfh);
2658         return mntroot;
2659 }
2660 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2661
2662 /*
2663  * Destroy an NFS2/3 superblock
2664  */
2665 void nfs_kill_super(struct super_block *s)
2666 {
2667         struct nfs_server *server = NFS_SB(s);
2668         dev_t dev = s->s_dev;
2669
2670         generic_shutdown_super(s);
2671
2672         nfs_fscache_release_super_cookie(s);
2673
2674         nfs_free_server(server);
2675         free_anon_bdev(dev);
2676 }
2677 EXPORT_SYMBOL_GPL(nfs_kill_super);
2678
2679 /*
2680  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2681  */
2682 static struct dentry *
2683 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2684                 const char *dev_name, void *raw_data)
2685 {
2686         struct nfs_clone_mount *data = raw_data;
2687         struct nfs_mount_info mount_info = {
2688                 .fill_super = nfs_clone_super,
2689                 .set_security = nfs_clone_sb_security,
2690                 .cloned = data,
2691         };
2692         struct nfs_server *server;
2693         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2694         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2695
2696         dprintk("--> nfs_xdev_mount()\n");
2697
2698         mount_info.mntfh = mount_info.cloned->fh;
2699
2700         /* create a new volume representation */
2701         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2702
2703         if (IS_ERR(server))
2704                 mntroot = ERR_CAST(server);
2705         else
2706                 mntroot = nfs_fs_mount_common(server, flags,
2707                                 dev_name, &mount_info, nfs_mod);
2708
2709         dprintk("<-- nfs_xdev_mount() = %ld\n",
2710                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2711         return mntroot;
2712 }
2713
2714 #if IS_ENABLED(CONFIG_NFS_V4)
2715
2716 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2717 {
2718         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2719                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2720 }
2721
2722 /*
2723  * Validate NFSv4 mount options
2724  */
2725 static int nfs4_validate_mount_data(void *options,
2726                                     struct nfs_parsed_mount_data *args,
2727                                     const char *dev_name)
2728 {
2729         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2730         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2731         char *c;
2732
2733         if (data == NULL)
2734                 goto out_no_data;
2735
2736         args->version = 4;
2737
2738         switch (data->version) {
2739         case 1:
2740                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2741                         goto out_no_address;
2742                 if (data->host_addrlen == 0)
2743                         goto out_no_address;
2744                 args->nfs_server.addrlen = data->host_addrlen;
2745                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2746                         return -EFAULT;
2747                 if (!nfs_verify_server_address(sap))
2748                         goto out_no_address;
2749                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2750
2751                 if (data->auth_flavourlen) {
2752                         rpc_authflavor_t pseudoflavor;
2753                         if (data->auth_flavourlen > 1)
2754                                 goto out_inval_auth;
2755                         if (copy_from_user(&pseudoflavor,
2756                                            data->auth_flavours,
2757                                            sizeof(pseudoflavor)))
2758                                 return -EFAULT;
2759                         args->selected_flavor = pseudoflavor;
2760                 } else
2761                         args->selected_flavor = RPC_AUTH_UNIX;
2762
2763                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2764                 if (IS_ERR(c))
2765                         return PTR_ERR(c);
2766                 args->nfs_server.hostname = c;
2767
2768                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2769                 if (IS_ERR(c))
2770                         return PTR_ERR(c);
2771                 args->nfs_server.export_path = c;
2772                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2773
2774                 c = strndup_user(data->client_addr.data, 16);
2775                 if (IS_ERR(c))
2776                         return PTR_ERR(c);
2777                 args->client_address = c;
2778
2779                 /*
2780                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2781                  * can deal with.
2782                  */
2783
2784                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2785                 args->rsize     = data->rsize;
2786                 args->wsize     = data->wsize;
2787                 args->timeo     = data->timeo;
2788                 args->retrans   = data->retrans;
2789                 args->acregmin  = data->acregmin;
2790                 args->acregmax  = data->acregmax;
2791                 args->acdirmin  = data->acdirmin;
2792                 args->acdirmax  = data->acdirmax;
2793                 args->nfs_server.protocol = data->proto;
2794                 nfs_validate_transport_protocol(args);
2795                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2796                         goto out_invalid_transport_udp;
2797
2798                 break;
2799         default:
2800                 return NFS_TEXT_DATA;
2801         }
2802
2803         return 0;
2804
2805 out_no_data:
2806         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2807         return -EINVAL;
2808
2809 out_inval_auth:
2810         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2811                  data->auth_flavourlen);
2812         return -EINVAL;
2813
2814 out_no_address:
2815         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2816         return -EINVAL;
2817
2818 out_invalid_transport_udp:
2819         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2820         return -EINVAL;
2821 }
2822
2823 /*
2824  * NFS v4 module parameters need to stay in the
2825  * NFS client for backwards compatibility
2826  */
2827 unsigned int nfs_callback_set_tcpport;
2828 /* Default cache timeout is 10 minutes */
2829 unsigned int nfs_idmap_cache_timeout = 600;
2830 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2831 bool nfs4_disable_idmapping = true;
2832 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2833 unsigned short send_implementation_id = 1;
2834 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2835 bool recover_lost_locks = false;
2836
2837 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2838 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2839 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2840 EXPORT_SYMBOL_GPL(max_session_slots);
2841 EXPORT_SYMBOL_GPL(send_implementation_id);
2842 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2843 EXPORT_SYMBOL_GPL(recover_lost_locks);
2844
2845 #define NFS_CALLBACK_MAXPORTNR (65535U)
2846
2847 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2848 {
2849         unsigned long num;
2850         int ret;
2851
2852         if (!val)
2853                 return -EINVAL;
2854         ret = kstrtoul(val, 0, &num);
2855         if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2856                 return -EINVAL;
2857         *((unsigned int *)kp->arg) = num;
2858         return 0;
2859 }
2860 static const struct kernel_param_ops param_ops_portnr = {
2861         .set = param_set_portnr,
2862         .get = param_get_uint,
2863 };
2864 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2865
2866 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2867 module_param(nfs_idmap_cache_timeout, int, 0644);
2868 module_param(nfs4_disable_idmapping, bool, 0644);
2869 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2870                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2871 MODULE_PARM_DESC(nfs4_disable_idmapping,
2872                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2873 module_param(max_session_slots, ushort, 0644);
2874 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2875                 "requests the client will negotiate");
2876 module_param(send_implementation_id, ushort, 0644);
2877 MODULE_PARM_DESC(send_implementation_id,
2878                 "Send implementation ID with NFSv4.1 exchange_id");
2879 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2880
2881 module_param(recover_lost_locks, bool, 0644);
2882 MODULE_PARM_DESC(recover_lost_locks,
2883                  "If the server reports that a lock might be lost, "
2884                  "try to recover it risking data corruption.");
2885
2886
2887 #endif /* CONFIG_NFS_V4 */