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/stats.h>
  35 #include <linux/sunrpc/metrics.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/sunrpc/xprtrdma.h>
  38 #include <linux/nfs_fs.h>
  39 #include <linux/nfs_mount.h>
  40 #include <linux/nfs4_mount.h>
  41 #include <linux/lockd/bind.h>
  42 #include <linux/seq_file.h>
  43 #include <linux/mount.h>
  44 #include <linux/namei.h>
  45 #include <linux/nfs_idmap.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 #include <linux/kthread.h>
  58
  59 #include <asm/uaccess.h>
  60
  61 #include "nfs4_fs.h"
  62 #include "callback.h"
  63 #include "delegation.h"
  64 #include "iostat.h"
  65 #include "internal.h"
  66 #include "fscache.h"
  67 #include "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
 195         Opt_xprt_err
 196 };
 197
 198 static const match_table_t nfs_xprt_protocol_tokens = {
 199         { Opt_xprt_udp, "udp" },
 200         { Opt_xprt_udp6, "udp6" },
 201         { Opt_xprt_tcp, "tcp" },
 202         { Opt_xprt_tcp6, "tcp6" },
 203         { Opt_xprt_rdma, "rdma" },
 204
 205         { Opt_xprt_err, NULL }
 206 };
 207
 208 enum {
 209         Opt_sec_none, Opt_sec_sys,
 210         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 211         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 212         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 213
 214         Opt_sec_err
 215 };
 216
 217 static const match_table_t nfs_secflavor_tokens = {
 218         { Opt_sec_none, "none" },
 219         { Opt_sec_none, "null" },
 220         { Opt_sec_sys, "sys" },
 221
 222         { Opt_sec_krb5, "krb5" },
 223         { Opt_sec_krb5i, "krb5i" },
 224         { Opt_sec_krb5p, "krb5p" },
 225
 226         { Opt_sec_lkey, "lkey" },
 227         { Opt_sec_lkeyi, "lkeyi" },
 228         { Opt_sec_lkeyp, "lkeyp" },
 229
 230         { Opt_sec_spkm, "spkm3" },
 231         { Opt_sec_spkmi, "spkm3i" },
 232         { Opt_sec_spkmp, "spkm3p" },
 233
 234         { Opt_sec_err, NULL }
 235 };
 236
 237 enum {
 238         Opt_lookupcache_all, Opt_lookupcache_positive,
 239         Opt_lookupcache_none,
 240
 241         Opt_lookupcache_err
 242 };
 243
 244 static match_table_t nfs_lookupcache_tokens = {
 245         { Opt_lookupcache_all, "all" },
 246         { Opt_lookupcache_positive, "pos" },
 247         { Opt_lookupcache_positive, "positive" },
 248         { Opt_lookupcache_none, "none" },
 249
 250         { Opt_lookupcache_err, NULL }
 251 };
 252
 253 enum {
 254         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 255         Opt_local_lock_none,
 256
 257         Opt_local_lock_err
 258 };
 259
 260 static match_table_t nfs_local_lock_tokens = {
 261         { Opt_local_lock_all, "all" },
 262         { Opt_local_lock_flock, "flock" },
 263         { Opt_local_lock_posix, "posix" },
 264         { Opt_local_lock_none, "none" },
 265
 266         { Opt_local_lock_err, NULL }
 267 };
 268
 269 enum {
 270         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 271         Opt_vers_4_1,
 272
 273         Opt_vers_err
 274 };
 275
 276 static match_table_t nfs_vers_tokens = {
 277         { Opt_vers_2, "2" },
 278         { Opt_vers_3, "3" },
 279         { Opt_vers_4, "4" },
 280         { Opt_vers_4_0, "4.0" },
 281         { Opt_vers_4_1, "4.1" },
 282
 283         { Opt_vers_err, NULL }
 284 };
 285
 286 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 287                 int flags, const char *dev_name, void *raw_data);
 288
 289 struct file_system_type nfs_fs_type = {
 290         .owner          = THIS_MODULE,
 291         .name           = "nfs",
 292         .mount          = nfs_fs_mount,
 293         .kill_sb        = nfs_kill_super,
 294         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 295 };
 296 EXPORT_SYMBOL_GPL(nfs_fs_type);
 297
 298 struct file_system_type nfs_xdev_fs_type = {
 299         .owner          = THIS_MODULE,
 300         .name           = "nfs",
 301         .mount          = nfs_xdev_mount,
 302         .kill_sb        = nfs_kill_super,
 303         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 304 };
 305
 306 const struct super_operations nfs_sops = {
 307         .alloc_inode    = nfs_alloc_inode,
 308         .destroy_inode  = nfs_destroy_inode,
 309         .write_inode    = nfs_write_inode,
 310         .put_super      = nfs_put_super,
 311         .statfs         = nfs_statfs,
 312         .evict_inode    = nfs_evict_inode,
 313         .umount_begin   = nfs_umount_begin,
 314         .show_options   = nfs_show_options,
 315         .show_devname   = nfs_show_devname,
 316         .show_path      = nfs_show_path,
 317         .show_stats     = nfs_show_stats,
 318         .remount_fs     = nfs_remount,
 319 };
 320 EXPORT_SYMBOL_GPL(nfs_sops);
 321
 322 #if IS_ENABLED(CONFIG_NFS_V4)
 323 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
 324 static int nfs4_validate_mount_data(void *options,
 325         struct nfs_parsed_mount_data *args, const char *dev_name);
 326
 327 struct file_system_type nfs4_fs_type = {
 328         .owner          = THIS_MODULE,
 329         .name           = "nfs4",
 330         .mount          = nfs_fs_mount,
 331         .kill_sb        = nfs_kill_super,
 332         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 333 };
 334 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 335
 336 static int __init register_nfs4_fs(void)
 337 {
 338         return register_filesystem(&nfs4_fs_type);
 339 }
 340
 341 static void unregister_nfs4_fs(void)
 342 {
 343         unregister_filesystem(&nfs4_fs_type);
 344 }
 345 #else
 346 static int __init register_nfs4_fs(void)
 347 {
 348         return 0;
 349 }
 350
 351 static void unregister_nfs4_fs(void)
 352 {
 353 }
 354 #endif
 355
 356 static struct shrinker acl_shrinker = {
 357         .shrink         = nfs_access_cache_shrinker,
 358         .seeks          = DEFAULT_SEEKS,
 359 };
 360
 361 /*
 362  * Register the NFS filesystems
 363  */
 364 int __init register_nfs_fs(void)
 365 {
 366         int ret;
 367
 368         ret = register_filesystem(&nfs_fs_type);
 369         if (ret < 0)
 370                 goto error_0;
 371
 372         ret = register_nfs4_fs();
 373         if (ret < 0)
 374                 goto error_1;
 375
 376         ret = nfs_register_sysctl();
 377         if (ret < 0)
 378                 goto error_2;
 379         register_shrinker(&acl_shrinker);
 380         return 0;
 381
 382 error_2:
 383         unregister_nfs4_fs();
 384 error_1:
 385         unregister_filesystem(&nfs_fs_type);
 386 error_0:
 387         return ret;
 388 }
 389
 390 /*
 391  * Unregister the NFS filesystems
 392  */
 393 void __exit unregister_nfs_fs(void)
 394 {
 395         unregister_shrinker(&acl_shrinker);
 396         nfs_unregister_sysctl();
 397         unregister_nfs4_fs();
 398         unregister_filesystem(&nfs_fs_type);
 399 }
 400
 401 void nfs_sb_active(struct super_block *sb)
 402 {
 403         struct nfs_server *server = NFS_SB(sb);
 404
 405         if (atomic_inc_return(&server->active) == 1)
 406                 atomic_inc(&sb->s_active);
 407 }
 408 EXPORT_SYMBOL_GPL(nfs_sb_active);
 409
 410 void nfs_sb_deactive(struct super_block *sb)
 411 {
 412         struct nfs_server *server = NFS_SB(sb);
 413
 414         if (atomic_dec_and_test(&server->active))
 415                 deactivate_super(sb);
 416 }
 417 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
 418
 419 static int nfs_deactivate_super_async_work(void *ptr)
 420 {
 421         struct super_block *sb = ptr;
 422
 423         deactivate_super(sb);
 424         module_put_and_exit(0);
 425         return 0;
 426 }
 427
 428 /*
 429  * same effect as deactivate_super, but will do final unmount in kthread
 430  * context
 431  */
 432 static void nfs_deactivate_super_async(struct super_block *sb)
 433 {
 434         struct task_struct *task;
 435         char buf[INET6_ADDRSTRLEN + 1];
 436         struct nfs_server *server = NFS_SB(sb);
 437         struct nfs_client *clp = server->nfs_client;
 438
 439         if (!atomic_add_unless(&sb->s_active, -1, 1)) {
 440                 rcu_read_lock();
 441                 snprintf(buf, sizeof(buf),
 442                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 443                 rcu_read_unlock();
 444
 445                 __module_get(THIS_MODULE);
 446                 task = kthread_run(nfs_deactivate_super_async_work, sb,
 447                                 "%s-deactivate-super", buf);
 448                 if (IS_ERR(task)) {
 449                         pr_err("%s: kthread_run: %ld\n",
 450                                 __func__, PTR_ERR(task));
 451                         /* make synchronous call and hope for the best */
 452                         deactivate_super(sb);
 453                         module_put(THIS_MODULE);
 454                 }
 455         }
 456 }
 457
 458 void nfs_sb_deactive_async(struct super_block *sb)
 459 {
 460         struct nfs_server *server = NFS_SB(sb);
 461
 462         if (atomic_dec_and_test(&server->active))
 463                 nfs_deactivate_super_async(sb);
 464 }
 465 EXPORT_SYMBOL_GPL(nfs_sb_deactive_async);
 466
 467 /*
 468  * Deliver file system statistics to userspace
 469  */
 470 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 471 {
 472         struct nfs_server *server = NFS_SB(dentry->d_sb);
 473         unsigned char blockbits;
 474         unsigned long blockres;
 475         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 476         struct nfs_fsstat res;
 477         int error = -ENOMEM;
 478
 479         res.fattr = nfs_alloc_fattr();
 480         if (res.fattr == NULL)
 481                 goto out_err;
 482
 483         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 484         if (unlikely(error == -ESTALE)) {
 485                 struct dentry *pd_dentry;
 486
 487                 pd_dentry = dget_parent(dentry);
 488                 if (pd_dentry != NULL) {
 489                         nfs_zap_caches(pd_dentry->d_inode);
 490                         dput(pd_dentry);
 491                 }
 492         }
 493         nfs_free_fattr(res.fattr);
 494         if (error < 0)
 495                 goto out_err;
 496
 497         buf->f_type = NFS_SUPER_MAGIC;
 498
 499         /*
 500          * Current versions of glibc do not correctly handle the
 501          * case where f_frsize != f_bsize.  Eventually we want to
 502          * report the value of wtmult in this field.
 503          */
 504         buf->f_frsize = dentry->d_sb->s_blocksize;
 505
 506         /*
 507          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 508          * are reported in units of f_frsize.  Linux hasn't had
 509          * an f_frsize field in its statfs struct until recently,
 510          * thus historically Linux's sys_statfs reports these
 511          * fields in units of f_bsize.
 512          */
 513         buf->f_bsize = dentry->d_sb->s_blocksize;
 514         blockbits = dentry->d_sb->s_blocksize_bits;
 515         blockres = (1 << blockbits) - 1;
 516         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 517         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 518         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 519
 520         buf->f_files = res.tfiles;
 521         buf->f_ffree = res.afiles;
 522
 523         buf->f_namelen = server->namelen;
 524
 525         return 0;
 526
 527  out_err:
 528         dprintk("%s: statfs error = %d\n", __func__, -error);
 529         return error;
 530 }
 531 EXPORT_SYMBOL_GPL(nfs_statfs);
 532
 533 /*
 534  * Map the security flavour number to a name
 535  */
 536 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 537 {
 538         static const struct {
 539                 rpc_authflavor_t flavour;
 540                 const char *str;
 541         } sec_flavours[] = {
 542                 { RPC_AUTH_NULL, "null" },
 543                 { RPC_AUTH_UNIX, "sys" },
 544                 { RPC_AUTH_GSS_KRB5, "krb5" },
 545                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 546                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 547                 { RPC_AUTH_GSS_LKEY, "lkey" },
 548                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 549                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 550                 { RPC_AUTH_GSS_SPKM, "spkm" },
 551                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 552                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 553                 { UINT_MAX, "unknown" }
 554         };
 555         int i;
 556
 557         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 558                 if (sec_flavours[i].flavour == flavour)
 559                         break;
 560         }
 561         return sec_flavours[i].str;
 562 }
 563
 564 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 565                                   int showdefaults)
 566 {
 567         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 568
 569         seq_printf(m, ",mountproto=");
 570         switch (sap->sa_family) {
 571         case AF_INET:
 572                 switch (nfss->mountd_protocol) {
 573                 case IPPROTO_UDP:
 574                         seq_printf(m, RPCBIND_NETID_UDP);
 575                         break;
 576                 case IPPROTO_TCP:
 577                         seq_printf(m, RPCBIND_NETID_TCP);
 578                         break;
 579                 default:
 580                         if (showdefaults)
 581                                 seq_printf(m, "auto");
 582                 }
 583                 break;
 584         case AF_INET6:
 585                 switch (nfss->mountd_protocol) {
 586                 case IPPROTO_UDP:
 587                         seq_printf(m, RPCBIND_NETID_UDP6);
 588                         break;
 589                 case IPPROTO_TCP:
 590                         seq_printf(m, RPCBIND_NETID_TCP6);
 591                         break;
 592                 default:
 593                         if (showdefaults)
 594                                 seq_printf(m, "auto");
 595                 }
 596                 break;
 597         default:
 598                 if (showdefaults)
 599                         seq_printf(m, "auto");
 600         }
 601 }
 602
 603 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 604                                     int showdefaults)
 605 {
 606         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 607
 608         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 609                 return;
 610
 611         switch (sap->sa_family) {
 612         case AF_INET: {
 613                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 614                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 615                 break;
 616         }
 617         case AF_INET6: {
 618                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 619                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 620                 break;
 621         }
 622         default:
 623                 if (showdefaults)
 624                         seq_printf(m, ",mountaddr=unspecified");
 625         }
 626
 627         if (nfss->mountd_version || showdefaults)
 628                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 629         if ((nfss->mountd_port &&
 630                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 631                 showdefaults)
 632                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 633
 634         nfs_show_mountd_netid(m, nfss, showdefaults);
 635 }
 636
 637 #if IS_ENABLED(CONFIG_NFS_V4)
 638 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 639                                     int showdefaults)
 640 {
 641         struct nfs_client *clp = nfss->nfs_client;
 642
 643         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 644 }
 645 #else
 646 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 647                                     int showdefaults)
 648 {
 649 }
 650 #endif
 651
 652 static void nfs_show_nfs_version(struct seq_file *m,
 653                 unsigned int version,
 654                 unsigned int minorversion)
 655 {
 656         seq_printf(m, ",vers=%u", version);
 657         if (version == 4)
 658                 seq_printf(m, ".%u", minorversion);
 659 }
 660
 661 /*
 662  * Describe the mount options in force on this server representation
 663  */
 664 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 665                                    int showdefaults)
 666 {
 667         static const struct proc_nfs_info {
 668                 int flag;
 669                 const char *str;
 670                 const char *nostr;
 671         } nfs_info[] = {
 672                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 673                 { NFS_MOUNT_POSIX, ",posix", "" },
 674                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 675                 { NFS_MOUNT_NOAC, ",noac", "" },
 676                 { NFS_MOUNT_NONLM, ",nolock", "" },
 677                 { NFS_MOUNT_NOACL, ",noacl", "" },
 678                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 679                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 680                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 681                 { 0, NULL, NULL }
 682         };
 683         const struct proc_nfs_info *nfs_infop;
 684         struct nfs_client *clp = nfss->nfs_client;
 685         u32 version = clp->rpc_ops->version;
 686         int local_flock, local_fcntl;
 687
 688         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 689         seq_printf(m, ",rsize=%u", nfss->rsize);
 690         seq_printf(m, ",wsize=%u", nfss->wsize);
 691         if (nfss->bsize != 0)
 692                 seq_printf(m, ",bsize=%u", nfss->bsize);
 693         seq_printf(m, ",namlen=%u", nfss->namelen);
 694         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 695                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 696         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 697                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 698         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 699                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 700         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 701                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 702         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 703                 if (nfss->flags & nfs_infop->flag)
 704                         seq_puts(m, nfs_infop->str);
 705                 else
 706                         seq_puts(m, nfs_infop->nostr);
 707         }
 708         rcu_read_lock();
 709         seq_printf(m, ",proto=%s",
 710                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 711         rcu_read_unlock();
 712         if (version == 4) {
 713                 if (nfss->port != NFS_PORT)
 714                         seq_printf(m, ",port=%u", nfss->port);
 715         } else
 716                 if (nfss->port)
 717                         seq_printf(m, ",port=%u", nfss->port);
 718
 719         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 720         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 721         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 722
 723         if (version != 4)
 724                 nfs_show_mountd_options(m, nfss, showdefaults);
 725         else
 726                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 727
 728         if (nfss->options & NFS_OPTION_FSCACHE)
 729                 seq_printf(m, ",fsc");
 730
 731         if (nfss->options & NFS_OPTION_MIGRATION)
 732                 seq_printf(m, ",migration");
 733
 734         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 735                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 736                         seq_printf(m, ",lookupcache=none");
 737                 else
 738                         seq_printf(m, ",lookupcache=pos");
 739         }
 740
 741         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 742         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 743
 744         if (!local_flock && !local_fcntl)
 745                 seq_printf(m, ",local_lock=none");
 746         else if (local_flock && local_fcntl)
 747                 seq_printf(m, ",local_lock=all");
 748         else if (local_flock)
 749                 seq_printf(m, ",local_lock=flock");
 750         else
 751                 seq_printf(m, ",local_lock=posix");
 752 }
 753
 754 /*
 755  * Describe the mount options on this VFS mountpoint
 756  */
 757 int nfs_show_options(struct seq_file *m, struct dentry *root)
 758 {
 759         struct nfs_server *nfss = NFS_SB(root->d_sb);
 760
 761         nfs_show_mount_options(m, nfss, 0);
 762
 763         rcu_read_lock();
 764         seq_printf(m, ",addr=%s",
 765                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 766                                                         RPC_DISPLAY_ADDR));
 767         rcu_read_unlock();
 768
 769         return 0;
 770 }
 771 EXPORT_SYMBOL_GPL(nfs_show_options);
 772
 773 #if IS_ENABLED(CONFIG_NFS_V4)
 774 #ifdef CONFIG_NFS_V4_1
 775 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 776 {
 777         if (nfs4_has_session(server->nfs_client))
 778                 seq_printf(m, ",sessions");
 779 }
 780 #else
 781 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 782 #endif
 783 #endif
 784
 785 #ifdef CONFIG_NFS_V4_1
 786 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 787 {
 788         seq_printf(m, ",pnfs=");
 789         if (server->pnfs_curr_ld)
 790                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 791         else
 792                 seq_printf(m, "not configured");
 793 }
 794
 795 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 796 {
 797         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 798                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 799                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 800                            "date='%llu,%u'",
 801                            impl_id->name, impl_id->domain,
 802                            impl_id->date.seconds, impl_id->date.nseconds);
 803         }
 804 }
 805 #else
 806 #if IS_ENABLED(CONFIG_NFS_V4)
 807 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 808 {
 809 }
 810 #endif
 811 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 812 {
 813 }
 814 #endif
 815
 816 int nfs_show_devname(struct seq_file *m, struct dentry *root)
 817 {
 818         char *page = (char *) __get_free_page(GFP_KERNEL);
 819         char *devname, *dummy;
 820         int err = 0;
 821         if (!page)
 822                 return -ENOMEM;
 823         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
 824         if (IS_ERR(devname))
 825                 err = PTR_ERR(devname);
 826         else
 827                 seq_escape(m, devname, " \t\n\\");
 828         free_page((unsigned long)page);
 829         return err;
 830 }
 831 EXPORT_SYMBOL_GPL(nfs_show_devname);
 832
 833 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 834 {
 835         seq_puts(m, "/");
 836         return 0;
 837 }
 838 EXPORT_SYMBOL_GPL(nfs_show_path);
 839
 840 /*
 841  * Present statistical information for this VFS mountpoint
 842  */
 843 int nfs_show_stats(struct seq_file *m, struct dentry *root)
 844 {
 845         int i, cpu;
 846         struct nfs_server *nfss = NFS_SB(root->d_sb);
 847         struct rpc_auth *auth = nfss->client->cl_auth;
 848         struct nfs_iostats totals = { };
 849
 850         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 851
 852         /*
 853          * Display all mount option settings
 854          */
 855         seq_printf(m, "\n\topts:\t");
 856         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 857         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 858         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 859         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 860         nfs_show_mount_options(m, nfss, 1);
 861
 862         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 863
 864         show_implementation_id(m, nfss);
 865
 866         seq_printf(m, "\n\tcaps:\t");
 867         seq_printf(m, "caps=0x%x", nfss->caps);
 868         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 869         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 870         seq_printf(m, ",bsize=%u", nfss->bsize);
 871         seq_printf(m, ",namlen=%u", nfss->namelen);
 872
 873 #if IS_ENABLED(CONFIG_NFS_V4)
 874         if (nfss->nfs_client->rpc_ops->version == 4) {
 875                 seq_printf(m, "\n\tnfsv4:\t");
 876                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 877                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 878                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 879                 show_sessions(m, nfss);
 880                 show_pnfs(m, nfss);
 881         }
 882 #endif
 883
 884         /*
 885          * Display security flavor in effect for this mount
 886          */
 887         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 888         if (auth->au_flavor)
 889                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 890
 891         /*
 892          * Display superblock I/O counters
 893          */
 894         for_each_possible_cpu(cpu) {
 895                 struct nfs_iostats *stats;
 896
 897                 preempt_disable();
 898                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 899
 900                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 901                         totals.events[i] += stats->events[i];
 902                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 903                         totals.bytes[i] += stats->bytes[i];
 904 #ifdef CONFIG_NFS_FSCACHE
 905                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 906                         totals.fscache[i] += stats->fscache[i];
 907 #endif
 908
 909                 preempt_enable();
 910         }
 911
 912         seq_printf(m, "\n\tevents:\t");
 913         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 914                 seq_printf(m, "%lu ", totals.events[i]);
 915         seq_printf(m, "\n\tbytes:\t");
 916         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 917                 seq_printf(m, "%Lu ", totals.bytes[i]);
 918 #ifdef CONFIG_NFS_FSCACHE
 919         if (nfss->options & NFS_OPTION_FSCACHE) {
 920                 seq_printf(m, "\n\tfsc:\t");
 921                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 922                         seq_printf(m, "%Lu ", totals.bytes[i]);
 923         }
 924 #endif
 925         seq_printf(m, "\n");
 926
 927         rpc_print_iostats(m, nfss->client);
 928
 929         return 0;
 930 }
 931 EXPORT_SYMBOL_GPL(nfs_show_stats);
 932
 933 /*
 934  * Begin unmount by attempting to remove all automounted mountpoints we added
 935  * in response to xdev traversals and referrals
 936  */
 937 void nfs_umount_begin(struct super_block *sb)
 938 {
 939         struct nfs_server *server;
 940         struct rpc_clnt *rpc;
 941
 942         server = NFS_SB(sb);
 943         /* -EIO all pending I/O */
 944         rpc = server->client_acl;
 945         if (!IS_ERR(rpc))
 946                 rpc_killall_tasks(rpc);
 947         rpc = server->client;
 948         if (!IS_ERR(rpc))
 949                 rpc_killall_tasks(rpc);
 950 }
 951 EXPORT_SYMBOL_GPL(nfs_umount_begin);
 952
 953 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 954 {
 955         struct nfs_parsed_mount_data *data;
 956
 957         data = kzalloc(sizeof(*data), GFP_KERNEL);
 958         if (data) {
 959                 data->acregmin          = NFS_DEF_ACREGMIN;
 960                 data->acregmax          = NFS_DEF_ACREGMAX;
 961                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 962                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 963                 data->mount_server.port = NFS_UNSPEC_PORT;
 964                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 965                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 966                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 967                 data->auth_flavor_len   = 1;
 968                 data->minorversion      = 0;
 969                 data->need_mount        = true;
 970                 data->net               = current->nsproxy->net_ns;
 971                 security_init_mnt_opts(&data->lsm_opts);
 972         }
 973         return data;
 974 }
 975
 976 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 977 {
 978         if (data) {
 979                 kfree(data->client_address);
 980                 kfree(data->mount_server.hostname);
 981                 kfree(data->nfs_server.export_path);
 982                 kfree(data->nfs_server.hostname);
 983                 kfree(data->fscache_uniq);
 984                 security_free_mnt_opts(&data->lsm_opts);
 985                 kfree(data);
 986         }
 987 }
 988
 989 /*
 990  * Sanity-check a server address provided by the mount command.
 991  *
 992  * Address family must be initialized, and address must not be
 993  * the ANY address for that family.
 994  */
 995 static int nfs_verify_server_address(struct sockaddr *addr)
 996 {
 997         switch (addr->sa_family) {
 998         case AF_INET: {
 999                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
1000                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
1001         }
1002         case AF_INET6: {
1003                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
1004                 return !ipv6_addr_any(sa);
1005         }
1006         }
1007
1008         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
1009         return 0;
1010 }
1011
1012 /*
1013  * Select between a default port value and a user-specified port value.
1014  * If a zero value is set, then autobind will be used.
1015  */
1016 static void nfs_set_port(struct sockaddr *sap, int *port,
1017                                  const unsigned short default_port)
1018 {
1019         if (*port == NFS_UNSPEC_PORT)
1020                 *port = default_port;
1021
1022         rpc_set_port(sap, *port);
1023 }
1024
1025 /*
1026  * Sanity check the NFS transport protocol.
1027  *
1028  */
1029 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1030 {
1031         switch (mnt->nfs_server.protocol) {
1032         case XPRT_TRANSPORT_UDP:
1033         case XPRT_TRANSPORT_TCP:
1034         case XPRT_TRANSPORT_RDMA:
1035                 break;
1036         default:
1037                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1038         }
1039 }
1040
1041 /*
1042  * For text based NFSv2/v3 mounts, the mount protocol transport default
1043  * settings should depend upon the specified NFS transport.
1044  */
1045 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1046 {
1047         nfs_validate_transport_protocol(mnt);
1048
1049         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1050             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1051                         return;
1052         switch (mnt->nfs_server.protocol) {
1053         case XPRT_TRANSPORT_UDP:
1054                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1055                 break;
1056         case XPRT_TRANSPORT_TCP:
1057         case XPRT_TRANSPORT_RDMA:
1058                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1059         }
1060 }
1061
1062 /*
1063  * Parse the value of the 'sec=' option.
1064  */
1065 static int nfs_parse_security_flavors(char *value,
1066                                       struct nfs_parsed_mount_data *mnt)
1067 {
1068         substring_t args[MAX_OPT_ARGS];
1069
1070         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1071
1072         switch (match_token(value, nfs_secflavor_tokens, args)) {
1073         case Opt_sec_none:
1074                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1075                 break;
1076         case Opt_sec_sys:
1077                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1078                 break;
1079         case Opt_sec_krb5:
1080                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1081                 break;
1082         case Opt_sec_krb5i:
1083                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1084                 break;
1085         case Opt_sec_krb5p:
1086                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1087                 break;
1088         case Opt_sec_lkey:
1089                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1090                 break;
1091         case Opt_sec_lkeyi:
1092                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1093                 break;
1094         case Opt_sec_lkeyp:
1095                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1096                 break;
1097         case Opt_sec_spkm:
1098                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1099                 break;
1100         case Opt_sec_spkmi:
1101                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1102                 break;
1103         case Opt_sec_spkmp:
1104                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1105                 break;
1106         default:
1107                 return 0;
1108         }
1109
1110         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1111         mnt->auth_flavor_len = 1;
1112         return 1;
1113 }
1114
1115 static int nfs_parse_version_string(char *string,
1116                 struct nfs_parsed_mount_data *mnt,
1117                 substring_t *args)
1118 {
1119         mnt->flags &= ~NFS_MOUNT_VER3;
1120         switch (match_token(string, nfs_vers_tokens, args)) {
1121         case Opt_vers_2:
1122                 mnt->version = 2;
1123                 break;
1124         case Opt_vers_3:
1125                 mnt->flags |= NFS_MOUNT_VER3;
1126                 mnt->version = 3;
1127                 break;
1128         case Opt_vers_4:
1129                 /* Backward compatibility option. In future,
1130                  * the mount program should always supply
1131                  * a NFSv4 minor version number.
1132                  */
1133                 mnt->version = 4;
1134                 break;
1135         case Opt_vers_4_0:
1136                 mnt->version = 4;
1137                 mnt->minorversion = 0;
1138                 break;
1139         case Opt_vers_4_1:
1140                 mnt->version = 4;
1141                 mnt->minorversion = 1;
1142                 break;
1143         default:
1144                 return 0;
1145         }
1146         return 1;
1147 }
1148
1149 static int nfs_get_option_str(substring_t args[], char **option)
1150 {
1151         kfree(*option);
1152         *option = match_strdup(args);
1153         return !option;
1154 }
1155
1156 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1157 {
1158         int rc;
1159         char *string;
1160
1161         string = match_strdup(args);
1162         if (string == NULL)
1163                 return -ENOMEM;
1164         rc = kstrtoul(string, 10, option);
1165         kfree(string);
1166
1167         return rc;
1168 }
1169
1170 /*
1171  * Error-check and convert a string of mount options from user space into
1172  * a data structure.  The whole mount string is processed; bad options are
1173  * skipped as they are encountered.  If there were no errors, return 1;
1174  * otherwise return 0 (zero).
1175  */
1176 static int nfs_parse_mount_options(char *raw,
1177                                    struct nfs_parsed_mount_data *mnt)
1178 {
1179         char *p, *string, *secdata;
1180         int rc, sloppy = 0, invalid_option = 0;
1181         unsigned short protofamily = AF_UNSPEC;
1182         unsigned short mountfamily = AF_UNSPEC;
1183
1184         if (!raw) {
1185                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1186                 return 1;
1187         }
1188         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1189
1190         secdata = alloc_secdata();
1191         if (!secdata)
1192                 goto out_nomem;
1193
1194         rc = security_sb_copy_data(raw, secdata);
1195         if (rc)
1196                 goto out_security_failure;
1197
1198         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1199         if (rc)
1200                 goto out_security_failure;
1201
1202         free_secdata(secdata);
1203
1204         while ((p = strsep(&raw, ",")) != NULL) {
1205                 substring_t args[MAX_OPT_ARGS];
1206                 unsigned long option;
1207                 int token;
1208
1209                 if (!*p)
1210                         continue;
1211
1212                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1213
1214                 token = match_token(p, nfs_mount_option_tokens, args);
1215                 switch (token) {
1216
1217                 /*
1218                  * boolean options:  foo/nofoo
1219                  */
1220                 case Opt_soft:
1221                         mnt->flags |= NFS_MOUNT_SOFT;
1222                         break;
1223                 case Opt_hard:
1224                         mnt->flags &= ~NFS_MOUNT_SOFT;
1225                         break;
1226                 case Opt_posix:
1227                         mnt->flags |= NFS_MOUNT_POSIX;
1228                         break;
1229                 case Opt_noposix:
1230                         mnt->flags &= ~NFS_MOUNT_POSIX;
1231                         break;
1232                 case Opt_cto:
1233                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1234                         break;
1235                 case Opt_nocto:
1236                         mnt->flags |= NFS_MOUNT_NOCTO;
1237                         break;
1238                 case Opt_ac:
1239                         mnt->flags &= ~NFS_MOUNT_NOAC;
1240                         break;
1241                 case Opt_noac:
1242                         mnt->flags |= NFS_MOUNT_NOAC;
1243                         break;
1244                 case Opt_lock:
1245                         mnt->flags &= ~NFS_MOUNT_NONLM;
1246                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1247                                         NFS_MOUNT_LOCAL_FCNTL);
1248                         break;
1249                 case Opt_nolock:
1250                         mnt->flags |= NFS_MOUNT_NONLM;
1251                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1252                                        NFS_MOUNT_LOCAL_FCNTL);
1253                         break;
1254                 case Opt_udp:
1255                         mnt->flags &= ~NFS_MOUNT_TCP;
1256                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1257                         break;
1258                 case Opt_tcp:
1259                         mnt->flags |= NFS_MOUNT_TCP;
1260                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1261                         break;
1262                 case Opt_rdma:
1263                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1264                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1265                         xprt_load_transport(p);
1266                         break;
1267                 case Opt_acl:
1268                         mnt->flags &= ~NFS_MOUNT_NOACL;
1269                         break;
1270                 case Opt_noacl:
1271                         mnt->flags |= NFS_MOUNT_NOACL;
1272                         break;
1273                 case Opt_rdirplus:
1274                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1275                         break;
1276                 case Opt_nordirplus:
1277                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1278                         break;
1279                 case Opt_sharecache:
1280                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1281                         break;
1282                 case Opt_nosharecache:
1283                         mnt->flags |= NFS_MOUNT_UNSHARED;
1284                         break;
1285                 case Opt_resvport:
1286                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1287                         break;
1288                 case Opt_noresvport:
1289                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1290                         break;
1291                 case Opt_fscache:
1292                         mnt->options |= NFS_OPTION_FSCACHE;
1293                         kfree(mnt->fscache_uniq);
1294                         mnt->fscache_uniq = NULL;
1295                         break;
1296                 case Opt_nofscache:
1297                         mnt->options &= ~NFS_OPTION_FSCACHE;
1298                         kfree(mnt->fscache_uniq);
1299                         mnt->fscache_uniq = NULL;
1300                         break;
1301                 case Opt_migration:
1302                         mnt->options |= NFS_OPTION_MIGRATION;
1303                         break;
1304                 case Opt_nomigration:
1305                         mnt->options &= NFS_OPTION_MIGRATION;
1306                         break;
1307
1308                 /*
1309                  * options that take numeric values
1310                  */
1311                 case Opt_port:
1312                         if (nfs_get_option_ul(args, &option) ||
1313                             option > USHRT_MAX)
1314                                 goto out_invalid_value;
1315                         mnt->nfs_server.port = option;
1316                         break;
1317                 case Opt_rsize:
1318                         if (nfs_get_option_ul(args, &option))
1319                                 goto out_invalid_value;
1320                         mnt->rsize = option;
1321                         break;
1322                 case Opt_wsize:
1323                         if (nfs_get_option_ul(args, &option))
1324                                 goto out_invalid_value;
1325                         mnt->wsize = option;
1326                         break;
1327                 case Opt_bsize:
1328                         if (nfs_get_option_ul(args, &option))
1329                                 goto out_invalid_value;
1330                         mnt->bsize = option;
1331                         break;
1332                 case Opt_timeo:
1333                         if (nfs_get_option_ul(args, &option) || option == 0)
1334                                 goto out_invalid_value;
1335                         mnt->timeo = option;
1336                         break;
1337                 case Opt_retrans:
1338                         if (nfs_get_option_ul(args, &option) || option == 0)
1339                                 goto out_invalid_value;
1340                         mnt->retrans = option;
1341                         break;
1342                 case Opt_acregmin:
1343                         if (nfs_get_option_ul(args, &option))
1344                                 goto out_invalid_value;
1345                         mnt->acregmin = option;
1346                         break;
1347                 case Opt_acregmax:
1348                         if (nfs_get_option_ul(args, &option))
1349                                 goto out_invalid_value;
1350                         mnt->acregmax = option;
1351                         break;
1352                 case Opt_acdirmin:
1353                         if (nfs_get_option_ul(args, &option))
1354                                 goto out_invalid_value;
1355                         mnt->acdirmin = option;
1356                         break;
1357                 case Opt_acdirmax:
1358                         if (nfs_get_option_ul(args, &option))
1359                                 goto out_invalid_value;
1360                         mnt->acdirmax = option;
1361                         break;
1362                 case Opt_actimeo:
1363                         if (nfs_get_option_ul(args, &option))
1364                                 goto out_invalid_value;
1365                         mnt->acregmin = mnt->acregmax =
1366                         mnt->acdirmin = mnt->acdirmax = option;
1367                         break;
1368                 case Opt_namelen:
1369                         if (nfs_get_option_ul(args, &option))
1370                                 goto out_invalid_value;
1371                         mnt->namlen = option;
1372                         break;
1373                 case Opt_mountport:
1374                         if (nfs_get_option_ul(args, &option) ||
1375                             option > USHRT_MAX)
1376                                 goto out_invalid_value;
1377                         mnt->mount_server.port = option;
1378                         break;
1379                 case Opt_mountvers:
1380                         if (nfs_get_option_ul(args, &option) ||
1381                             option < NFS_MNT_VERSION ||
1382                             option > NFS_MNT3_VERSION)
1383                                 goto out_invalid_value;
1384                         mnt->mount_server.version = option;
1385                         break;
1386                 case Opt_minorversion:
1387                         if (nfs_get_option_ul(args, &option))
1388                                 goto out_invalid_value;
1389                         if (option > NFS4_MAX_MINOR_VERSION)
1390                                 goto out_invalid_value;
1391                         mnt->minorversion = option;
1392                         break;
1393
1394                 /*
1395                  * options that take text values
1396                  */
1397                 case Opt_nfsvers:
1398                         string = match_strdup(args);
1399                         if (string == NULL)
1400                                 goto out_nomem;
1401                         rc = nfs_parse_version_string(string, mnt, args);
1402                         kfree(string);
1403                         if (!rc)
1404                                 goto out_invalid_value;
1405                         break;
1406                 case Opt_sec:
1407                         string = match_strdup(args);
1408                         if (string == NULL)
1409                                 goto out_nomem;
1410                         rc = nfs_parse_security_flavors(string, mnt);
1411                         kfree(string);
1412                         if (!rc) {
1413                                 dfprintk(MOUNT, "NFS:   unrecognized "
1414                                                 "security flavor\n");
1415                                 return 0;
1416                         }
1417                         break;
1418                 case Opt_proto:
1419                         string = match_strdup(args);
1420                         if (string == NULL)
1421                                 goto out_nomem;
1422                         token = match_token(string,
1423                                             nfs_xprt_protocol_tokens, args);
1424
1425                         protofamily = AF_INET;
1426                         switch (token) {
1427                         case Opt_xprt_udp6:
1428                                 protofamily = AF_INET6;
1429                         case Opt_xprt_udp:
1430                                 mnt->flags &= ~NFS_MOUNT_TCP;
1431                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1432                                 break;
1433                         case Opt_xprt_tcp6:
1434                                 protofamily = AF_INET6;
1435                         case Opt_xprt_tcp:
1436                                 mnt->flags |= NFS_MOUNT_TCP;
1437                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1438                                 break;
1439                         case Opt_xprt_rdma:
1440                                 /* vector side protocols to TCP */
1441                                 mnt->flags |= NFS_MOUNT_TCP;
1442                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1443                                 xprt_load_transport(string);
1444                                 break;
1445                         default:
1446                                 dfprintk(MOUNT, "NFS:   unrecognized "
1447                                                 "transport protocol\n");
1448                                 kfree(string);
1449                                 return 0;
1450                         }
1451                         kfree(string);
1452                         break;
1453                 case Opt_mountproto:
1454                         string = match_strdup(args);
1455                         if (string == NULL)
1456                                 goto out_nomem;
1457                         token = match_token(string,
1458                                             nfs_xprt_protocol_tokens, args);
1459                         kfree(string);
1460
1461                         mountfamily = AF_INET;
1462                         switch (token) {
1463                         case Opt_xprt_udp6:
1464                                 mountfamily = AF_INET6;
1465                         case Opt_xprt_udp:
1466                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1467                                 break;
1468                         case Opt_xprt_tcp6:
1469                                 mountfamily = AF_INET6;
1470                         case Opt_xprt_tcp:
1471                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1472                                 break;
1473                         case Opt_xprt_rdma: /* not used for side protocols */
1474                         default:
1475                                 dfprintk(MOUNT, "NFS:   unrecognized "
1476                                                 "transport protocol\n");
1477                                 return 0;
1478                         }
1479                         break;
1480                 case Opt_addr:
1481                         string = match_strdup(args);
1482                         if (string == NULL)
1483                                 goto out_nomem;
1484                         mnt->nfs_server.addrlen =
1485                                 rpc_pton(mnt->net, string, strlen(string),
1486                                         (struct sockaddr *)
1487                                         &mnt->nfs_server.address,
1488                                         sizeof(mnt->nfs_server.address));
1489                         kfree(string);
1490                         if (mnt->nfs_server.addrlen == 0)
1491                                 goto out_invalid_address;
1492                         break;
1493                 case Opt_clientaddr:
1494                         if (nfs_get_option_str(args, &mnt->client_address))
1495                                 goto out_nomem;
1496                         break;
1497                 case Opt_mounthost:
1498                         if (nfs_get_option_str(args,
1499                                                &mnt->mount_server.hostname))
1500                                 goto out_nomem;
1501                         break;
1502                 case Opt_mountaddr:
1503                         string = match_strdup(args);
1504                         if (string == NULL)
1505                                 goto out_nomem;
1506                         mnt->mount_server.addrlen =
1507                                 rpc_pton(mnt->net, string, strlen(string),
1508                                         (struct sockaddr *)
1509                                         &mnt->mount_server.address,
1510                                         sizeof(mnt->mount_server.address));
1511                         kfree(string);
1512                         if (mnt->mount_server.addrlen == 0)
1513                                 goto out_invalid_address;
1514                         break;
1515                 case Opt_lookupcache:
1516                         string = match_strdup(args);
1517                         if (string == NULL)
1518                                 goto out_nomem;
1519                         token = match_token(string,
1520                                         nfs_lookupcache_tokens, args);
1521                         kfree(string);
1522                         switch (token) {
1523                                 case Opt_lookupcache_all:
1524                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1525                                         break;
1526                                 case Opt_lookupcache_positive:
1527                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1528                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1529                                         break;
1530                                 case Opt_lookupcache_none:
1531                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1532                                         break;
1533                                 default:
1534                                         dfprintk(MOUNT, "NFS:   invalid "
1535                                                         "lookupcache argument\n");
1536                                         return 0;
1537                         };
1538                         break;
1539                 case Opt_fscache_uniq:
1540                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1541                                 goto out_nomem;
1542                         mnt->options |= NFS_OPTION_FSCACHE;
1543                         break;
1544                 case Opt_local_lock:
1545                         string = match_strdup(args);
1546                         if (string == NULL)
1547                                 goto out_nomem;
1548                         token = match_token(string, nfs_local_lock_tokens,
1549                                         args);
1550                         kfree(string);
1551                         switch (token) {
1552                         case Opt_local_lock_all:
1553                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1554                                                NFS_MOUNT_LOCAL_FCNTL);
1555                                 break;
1556                         case Opt_local_lock_flock:
1557                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1558                                 break;
1559                         case Opt_local_lock_posix:
1560                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1561                                 break;
1562                         case Opt_local_lock_none:
1563                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1564                                                 NFS_MOUNT_LOCAL_FCNTL);
1565                                 break;
1566                         default:
1567                                 dfprintk(MOUNT, "NFS:   invalid "
1568                                                 "local_lock argument\n");
1569                                 return 0;
1570                         };
1571                         break;
1572
1573                 /*
1574                  * Special options
1575                  */
1576                 case Opt_sloppy:
1577                         sloppy = 1;
1578                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1579                         break;
1580                 case Opt_userspace:
1581                 case Opt_deprecated:
1582                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1583                                         "'%s'\n", p);
1584                         break;
1585
1586                 default:
1587                         invalid_option = 1;
1588                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1589                                         "'%s'\n", p);
1590                 }
1591         }
1592
1593         if (!sloppy && invalid_option)
1594                 return 0;
1595
1596         if (mnt->minorversion && mnt->version != 4)
1597                 goto out_minorversion_mismatch;
1598
1599         if (mnt->options & NFS_OPTION_MIGRATION &&
1600             mnt->version != 4 && mnt->minorversion != 0)
1601                 goto out_migration_misuse;
1602
1603         /*
1604          * verify that any proto=/mountproto= options match the address
1605          * families in the addr=/mountaddr= options.
1606          */
1607         if (protofamily != AF_UNSPEC &&
1608             protofamily != mnt->nfs_server.address.ss_family)
1609                 goto out_proto_mismatch;
1610
1611         if (mountfamily != AF_UNSPEC) {
1612                 if (mnt->mount_server.addrlen) {
1613                         if (mountfamily != mnt->mount_server.address.ss_family)
1614                                 goto out_mountproto_mismatch;
1615                 } else {
1616                         if (mountfamily != mnt->nfs_server.address.ss_family)
1617                                 goto out_mountproto_mismatch;
1618                 }
1619         }
1620
1621         return 1;
1622
1623 out_mountproto_mismatch:
1624         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1625                          "option\n");
1626         return 0;
1627 out_proto_mismatch:
1628         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1629         return 0;
1630 out_invalid_address:
1631         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1632         return 0;
1633 out_invalid_value:
1634         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1635         return 0;
1636 out_minorversion_mismatch:
1637         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1638                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1639         return 0;
1640 out_migration_misuse:
1641         printk(KERN_INFO
1642                 "NFS: 'migration' not supported for this NFS version\n");
1643         return 0;
1644 out_nomem:
1645         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1646         return 0;
1647 out_security_failure:
1648         free_secdata(secdata);
1649         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1650         return 0;
1651 }
1652
1653 /*
1654  * Match the requested auth flavors with the list returned by
1655  * the server.  Returns zero and sets the mount's authentication
1656  * flavor on success; returns -EACCES if server does not support
1657  * the requested flavor.
1658  */
1659 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1660                              struct nfs_mount_request *request)
1661 {
1662         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1663
1664         /*
1665          * Certain releases of Linux's mountd return an empty
1666          * flavor list.  To prevent behavioral regression with
1667          * these servers (ie. rejecting mounts that used to
1668          * succeed), revert to pre-2.6.32 behavior (no checking)
1669          * if the returned flavor list is empty.
1670          */
1671         if (server_authlist_len == 0)
1672                 return 0;
1673
1674         /*
1675          * We avoid sophisticated negotiating here, as there are
1676          * plenty of cases where we can get it wrong, providing
1677          * either too little or too much security.
1678          *
1679          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1680          * flavor listed first.  However, some servers list
1681          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1682          * preferred default, in args->auth_flavors[0] if user
1683          * didn't specify sec= mount option.
1684          */
1685         for (i = 0; i < args->auth_flavor_len; i++)
1686                 for (j = 0; j < server_authlist_len; j++)
1687                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1688                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1689                                         request->auth_flavs[j]);
1690                                 args->auth_flavors[0] = request->auth_flavs[j];
1691                                 return 0;
1692                         }
1693
1694         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1695         nfs_umount(request);
1696         return -EACCES;
1697 }
1698
1699 /*
1700  * Use the remote server's MOUNT service to request the NFS file handle
1701  * corresponding to the provided path.
1702  */
1703 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1704                              struct nfs_fh *root_fh)
1705 {
1706         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1707         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1708         struct nfs_mount_request request = {
1709                 .sap            = (struct sockaddr *)
1710                                                 &args->mount_server.address,
1711                 .dirpath        = args->nfs_server.export_path,
1712                 .protocol       = args->mount_server.protocol,
1713                 .fh             = root_fh,
1714                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1715                 .auth_flav_len  = &server_authlist_len,
1716                 .auth_flavs     = server_authlist,
1717                 .net            = args->net,
1718         };
1719         int status;
1720
1721         if (args->mount_server.version == 0) {
1722                 switch (args->version) {
1723                         default:
1724                                 args->mount_server.version = NFS_MNT3_VERSION;
1725                                 break;
1726                         case 2:
1727                                 args->mount_server.version = NFS_MNT_VERSION;
1728                 }
1729         }
1730         request.version = args->mount_server.version;
1731
1732         if (args->mount_server.hostname)
1733                 request.hostname = args->mount_server.hostname;
1734         else
1735                 request.hostname = args->nfs_server.hostname;
1736
1737         /*
1738          * Construct the mount server's address.
1739          */
1740         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1741                 memcpy(request.sap, &args->nfs_server.address,
1742                        args->nfs_server.addrlen);
1743                 args->mount_server.addrlen = args->nfs_server.addrlen;
1744         }
1745         request.salen = args->mount_server.addrlen;
1746         nfs_set_port(request.sap, &args->mount_server.port, 0);
1747
1748         /*
1749          * Now ask the mount server to map our export path
1750          * to a file handle.
1751          */
1752         status = nfs_mount(&request);
1753         if (status != 0) {
1754                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1755                                 request.hostname, status);
1756                 return status;
1757         }
1758
1759         /*
1760          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1761          */
1762         if (args->mount_server.version != NFS_MNT3_VERSION)
1763                 return 0;
1764         return nfs_walk_authlist(args, &request);
1765 }
1766
1767 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1768                              struct nfs_mount_info *mount_info,
1769                              struct nfs_subversion *nfs_mod)
1770 {
1771         int status;
1772         struct nfs_server *server;
1773
1774         if (mount_info->parsed->need_mount) {
1775                 status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1776                 if (status)
1777                         return ERR_PTR(status);
1778         }
1779
1780         /* Get a volume representation */
1781         server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1782         if (IS_ERR(server))
1783                 return ERR_CAST(server);
1784
1785         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1786 }
1787 EXPORT_SYMBOL_GPL(nfs_try_mount);
1788
1789 /*
1790  * Split "dev_name" into "hostname:export_path".
1791  *
1792  * The leftmost colon demarks the split between the server's hostname
1793  * and the export path.  If the hostname starts with a left square
1794  * bracket, then it may contain colons.
1795  *
1796  * Note: caller frees hostname and export path, even on error.
1797  */
1798 static int nfs_parse_devname(const char *dev_name,
1799                              char **hostname, size_t maxnamlen,
1800                              char **export_path, size_t maxpathlen)
1801 {
1802         size_t len;
1803         char *end;
1804
1805         /* Is the host name protected with square brakcets? */
1806         if (*dev_name == '[') {
1807                 end = strchr(++dev_name, ']');
1808                 if (end == NULL || end[1] != ':')
1809                         goto out_bad_devname;
1810
1811                 len = end - dev_name;
1812                 end++;
1813         } else {
1814                 char *comma;
1815
1816                 end = strchr(dev_name, ':');
1817                 if (end == NULL)
1818                         goto out_bad_devname;
1819                 len = end - dev_name;
1820
1821                 /* kill possible hostname list: not supported */
1822                 comma = strchr(dev_name, ',');
1823                 if (comma != NULL && comma < end)
1824                         *comma = 0;
1825         }
1826
1827         if (len > maxnamlen)
1828                 goto out_hostname;
1829
1830         /* N.B. caller will free nfs_server.hostname in all cases */
1831         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1832         if (*hostname == NULL)
1833                 goto out_nomem;
1834         len = strlen(++end);
1835         if (len > maxpathlen)
1836                 goto out_path;
1837         *export_path = kstrndup(end, len, GFP_KERNEL);
1838         if (!*export_path)
1839                 goto out_nomem;
1840
1841         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1842         return 0;
1843
1844 out_bad_devname:
1845         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1846         return -EINVAL;
1847
1848 out_nomem:
1849         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1850         return -ENOMEM;
1851
1852 out_hostname:
1853         dfprintk(MOUNT, "NFS: server hostname too long\n");
1854         return -ENAMETOOLONG;
1855
1856 out_path:
1857         dfprintk(MOUNT, "NFS: export pathname too long\n");
1858         return -ENAMETOOLONG;
1859 }
1860
1861 /*
1862  * Validate the NFS2/NFS3 mount data
1863  * - fills in the mount root filehandle
1864  *
1865  * For option strings, user space handles the following behaviors:
1866  *
1867  * + DNS: mapping server host name to IP address ("addr=" option)
1868  *
1869  * + failure mode: how to behave if a mount request can't be handled
1870  *   immediately ("fg/bg" option)
1871  *
1872  * + retry: how often to retry a mount request ("retry=" option)
1873  *
1874  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1875  *   mountproto=tcp after mountproto=udp, and so on
1876  */
1877 static int nfs23_validate_mount_data(void *options,
1878                                      struct nfs_parsed_mount_data *args,
1879                                      struct nfs_fh *mntfh,
1880                                      const char *dev_name)
1881 {
1882         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1883         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1884
1885         if (data == NULL)
1886                 goto out_no_data;
1887
1888         args->version = NFS_DEFAULT_VERSION;
1889         switch (data->version) {
1890         case 1:
1891                 data->namlen = 0;
1892         case 2:
1893                 data->bsize = 0;
1894         case 3:
1895                 if (data->flags & NFS_MOUNT_VER3)
1896                         goto out_no_v3;
1897                 data->root.size = NFS2_FHSIZE;
1898                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1899         case 4:
1900                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1901                         goto out_no_sec;
1902         case 5:
1903                 memset(data->context, 0, sizeof(data->context));
1904         case 6:
1905                 if (data->flags & NFS_MOUNT_VER3) {
1906                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1907                                 goto out_invalid_fh;
1908                         mntfh->size = data->root.size;
1909                         args->version = 3;
1910                 } else {
1911                         mntfh->size = NFS2_FHSIZE;
1912                         args->version = 2;
1913                 }
1914
1915
1916                 memcpy(mntfh->data, data->root.data, mntfh->size);
1917                 if (mntfh->size < sizeof(mntfh->data))
1918                         memset(mntfh->data + mntfh->size, 0,
1919                                sizeof(mntfh->data) - mntfh->size);
1920
1921                 /*
1922                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1923                  * can deal with.
1924                  */
1925                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1926                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1927                 args->rsize             = data->rsize;
1928                 args->wsize             = data->wsize;
1929                 args->timeo             = data->timeo;
1930                 args->retrans           = data->retrans;
1931                 args->acregmin          = data->acregmin;
1932                 args->acregmax          = data->acregmax;
1933                 args->acdirmin          = data->acdirmin;
1934                 args->acdirmax          = data->acdirmax;
1935                 args->need_mount        = false;
1936
1937                 memcpy(sap, &data->addr, sizeof(data->addr));
1938                 args->nfs_server.addrlen = sizeof(data->addr);
1939                 args->nfs_server.port = ntohs(data->addr.sin_port);
1940                 if (!nfs_verify_server_address(sap))
1941                         goto out_no_address;
1942
1943                 if (!(data->flags & NFS_MOUNT_TCP))
1944                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1945                 /* N.B. caller will free nfs_server.hostname in all cases */
1946                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1947                 args->namlen            = data->namlen;
1948                 args->bsize             = data->bsize;
1949
1950                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1951                         args->auth_flavors[0] = data->pseudoflavor;
1952                 if (!args->nfs_server.hostname)
1953                         goto out_nomem;
1954
1955                 if (!(data->flags & NFS_MOUNT_NONLM))
1956                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1957                                          NFS_MOUNT_LOCAL_FCNTL);
1958                 else
1959                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1960                                         NFS_MOUNT_LOCAL_FCNTL);
1961                 /*
1962                  * The legacy version 6 binary mount data from userspace has a
1963                  * field used only to transport selinux information into the
1964                  * the kernel.  To continue to support that functionality we
1965                  * have a touch of selinux knowledge here in the NFS code. The
1966                  * userspace code converted context=blah to just blah so we are
1967                  * converting back to the full string selinux understands.
1968                  */
1969                 if (data->context[0]){
1970 #ifdef CONFIG_SECURITY_SELINUX
1971                         int rc;
1972                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1973                         if (!opts_str)
1974                                 return -ENOMEM;
1975                         strcpy(opts_str, "context=");
1976                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1977                         strcat(opts_str, &data->context[0]);
1978                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1979                         kfree(opts_str);
1980                         if (rc)
1981                                 return rc;
1982 #else
1983                         return -EINVAL;
1984 #endif
1985                 }
1986
1987                 break;
1988         default:
1989                 return NFS_TEXT_DATA;
1990         }
1991
1992 #if !IS_ENABLED(CONFIG_NFS_V3)
1993         if (args->version == 3)
1994                 goto out_v3_not_compiled;
1995 #endif /* !CONFIG_NFS_V3 */
1996
1997         return 0;
1998
1999 out_no_data:
2000         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2001         return -EINVAL;
2002
2003 out_no_v3:
2004         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2005                  data->version);
2006         return -EINVAL;
2007
2008 out_no_sec:
2009         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2010         return -EINVAL;
2011
2012 #if !IS_ENABLED(CONFIG_NFS_V3)
2013 out_v3_not_compiled:
2014         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
2015         return -EPROTONOSUPPORT;
2016 #endif /* !CONFIG_NFS_V3 */
2017
2018 out_nomem:
2019         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2020         return -ENOMEM;
2021
2022 out_no_address:
2023         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2024         return -EINVAL;
2025
2026 out_invalid_fh:
2027         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2028         return -EINVAL;
2029 }
2030
2031 #if IS_ENABLED(CONFIG_NFS_V4)
2032 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2033                                    void *options,
2034                                    struct nfs_parsed_mount_data *args,
2035                                    struct nfs_fh *mntfh,
2036                                    const char *dev_name)
2037 {
2038         if (fs_type == &nfs_fs_type)
2039                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2040         return nfs4_validate_mount_data(options, args, dev_name);
2041 }
2042 #else
2043 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2044                                    void *options,
2045                                    struct nfs_parsed_mount_data *args,
2046                                    struct nfs_fh *mntfh,
2047                                    const char *dev_name)
2048 {
2049         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2050 }
2051 #endif
2052
2053 static int nfs_validate_text_mount_data(void *options,
2054                                         struct nfs_parsed_mount_data *args,
2055                                         const char *dev_name)
2056 {
2057         int port = 0;
2058         int max_namelen = PAGE_SIZE;
2059         int max_pathlen = NFS_MAXPATHLEN;
2060         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2061
2062         if (nfs_parse_mount_options((char *)options, args) == 0)
2063                 return -EINVAL;
2064
2065         if (!nfs_verify_server_address(sap))
2066                 goto out_no_address;
2067
2068         if (args->version == 4) {
2069 #if IS_ENABLED(CONFIG_NFS_V4)
2070                 port = NFS_PORT;
2071                 max_namelen = NFS4_MAXNAMLEN;
2072                 max_pathlen = NFS4_MAXPATHLEN;
2073                 nfs_validate_transport_protocol(args);
2074                 nfs4_validate_mount_flags(args);
2075 #else
2076                 goto out_v4_not_compiled;
2077 #endif /* CONFIG_NFS_V4 */
2078         } else
2079                 nfs_set_mount_transport_protocol(args);
2080
2081         nfs_set_port(sap, &args->nfs_server.port, port);
2082
2083         if (args->auth_flavor_len > 1)
2084                 goto out_bad_auth;
2085
2086         return nfs_parse_devname(dev_name,
2087                                    &args->nfs_server.hostname,
2088                                    max_namelen,
2089                                    &args->nfs_server.export_path,
2090                                    max_pathlen);
2091
2092 #if !IS_ENABLED(CONFIG_NFS_V4)
2093 out_v4_not_compiled:
2094         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2095         return -EPROTONOSUPPORT;
2096 #endif /* !CONFIG_NFS_V4 */
2097
2098 out_no_address:
2099         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2100         return -EINVAL;
2101
2102 out_bad_auth:
2103         dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2104         return -EINVAL;
2105 }
2106
2107 static int
2108 nfs_compare_remount_data(struct nfs_server *nfss,
2109                          struct nfs_parsed_mount_data *data)
2110 {
2111         if (data->flags != nfss->flags ||
2112             data->rsize != nfss->rsize ||
2113             data->wsize != nfss->wsize ||
2114             data->retrans != nfss->client->cl_timeout->to_retries ||
2115             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2116             data->acregmin != nfss->acregmin / HZ ||
2117             data->acregmax != nfss->acregmax / HZ ||
2118             data->acdirmin != nfss->acdirmin / HZ ||
2119             data->acdirmax != nfss->acdirmax / HZ ||
2120             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2121             data->nfs_server.port != nfss->port ||
2122             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2123             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2124                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2125                 return -EINVAL;
2126
2127         return 0;
2128 }
2129
2130 int
2131 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2132 {
2133         int error;
2134         struct nfs_server *nfss = sb->s_fs_info;
2135         struct nfs_parsed_mount_data *data;
2136         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2137         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2138         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2139
2140         /*
2141          * Userspace mount programs that send binary options generally send
2142          * them populated with default values. We have no way to know which
2143          * ones were explicitly specified. Fall back to legacy behavior and
2144          * just return success.
2145          */
2146         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2147             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2148                                            options->version <= 6))))
2149                 return 0;
2150
2151         data = kzalloc(sizeof(*data), GFP_KERNEL);
2152         if (data == NULL)
2153                 return -ENOMEM;
2154
2155         /* fill out struct with values from existing mount */
2156         data->flags = nfss->flags;
2157         data->rsize = nfss->rsize;
2158         data->wsize = nfss->wsize;
2159         data->retrans = nfss->client->cl_timeout->to_retries;
2160         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2161         data->acregmin = nfss->acregmin / HZ;
2162         data->acregmax = nfss->acregmax / HZ;
2163         data->acdirmin = nfss->acdirmin / HZ;
2164         data->acdirmax = nfss->acdirmax / HZ;
2165         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2166         data->nfs_server.port = nfss->port;
2167         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2168         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2169                 data->nfs_server.addrlen);
2170
2171         /* overwrite those values with any that were specified */
2172         error = nfs_parse_mount_options((char *)options, data);
2173         if (error < 0)
2174                 goto out;
2175
2176         /*
2177          * noac is a special case. It implies -o sync, but that's not
2178          * necessarily reflected in the mtab options. do_remount_sb
2179          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2180          * remount options, so we have to explicitly reset it.
2181          */
2182         if (data->flags & NFS_MOUNT_NOAC)
2183                 *flags |= MS_SYNCHRONOUS;
2184
2185         /* compare new mount options with old ones */
2186         error = nfs_compare_remount_data(nfss, data);
2187 out:
2188         kfree(data);
2189         return error;
2190 }
2191 EXPORT_SYMBOL_GPL(nfs_remount);
2192
2193 /*
2194  * Initialise the common bits of the superblock
2195  */
2196 inline void nfs_initialise_sb(struct super_block *sb)
2197 {
2198         struct nfs_server *server = NFS_SB(sb);
2199
2200         sb->s_magic = NFS_SUPER_MAGIC;
2201
2202         /* We probably want something more informative here */
2203         snprintf(sb->s_id, sizeof(sb->s_id),
2204                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2205
2206         if (sb->s_blocksize == 0)
2207                 sb->s_blocksize = nfs_block_bits(server->wsize,
2208                                                  &sb->s_blocksize_bits);
2209
2210         sb->s_bdi = &server->backing_dev_info;
2211
2212         nfs_super_set_maxbytes(sb, server->maxfilesize);
2213 }
2214
2215 /*
2216  * Finish setting up an NFS2/3 superblock
2217  */
2218 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2219 {
2220         struct nfs_parsed_mount_data *data = mount_info->parsed;
2221         struct nfs_server *server = NFS_SB(sb);
2222
2223         sb->s_blocksize_bits = 0;
2224         sb->s_blocksize = 0;
2225         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2226         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2227         if (data && data->bsize)
2228                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2229
2230         if (server->nfs_client->rpc_ops->version != 2) {
2231                 /* The VFS shouldn't apply the umask to mode bits. We will do
2232                  * so ourselves when necessary.
2233                  */
2234                 sb->s_flags |= MS_POSIXACL;
2235                 sb->s_time_gran = 1;
2236         }
2237
2238         nfs_initialise_sb(sb);
2239 }
2240 EXPORT_SYMBOL_GPL(nfs_fill_super);
2241
2242 /*
2243  * Finish setting up a cloned NFS2/3/4 superblock
2244  */
2245 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2246 {
2247         const struct super_block *old_sb = mount_info->cloned->sb;
2248         struct nfs_server *server = NFS_SB(sb);
2249
2250         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2251         sb->s_blocksize = old_sb->s_blocksize;
2252         sb->s_maxbytes = old_sb->s_maxbytes;
2253         sb->s_xattr = old_sb->s_xattr;
2254         sb->s_op = old_sb->s_op;
2255         sb->s_time_gran = 1;
2256
2257         if (server->nfs_client->rpc_ops->version != 2) {
2258                 /* The VFS shouldn't apply the umask to mode bits. We will do
2259                  * so ourselves when necessary.
2260                  */
2261                 sb->s_flags |= MS_POSIXACL;
2262         }
2263
2264         nfs_initialise_sb(sb);
2265 }
2266
2267 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2268 {
2269         const struct nfs_server *a = s->s_fs_info;
2270         const struct rpc_clnt *clnt_a = a->client;
2271         const struct rpc_clnt *clnt_b = b->client;
2272
2273         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2274                 goto Ebusy;
2275         if (a->nfs_client != b->nfs_client)
2276                 goto Ebusy;
2277         if (a->flags != b->flags)
2278                 goto Ebusy;
2279         if (a->wsize != b->wsize)
2280                 goto Ebusy;
2281         if (a->rsize != b->rsize)
2282                 goto Ebusy;
2283         if (a->acregmin != b->acregmin)
2284                 goto Ebusy;
2285         if (a->acregmax != b->acregmax)
2286                 goto Ebusy;
2287         if (a->acdirmin != b->acdirmin)
2288                 goto Ebusy;
2289         if (a->acdirmax != b->acdirmax)
2290                 goto Ebusy;
2291         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2292                 goto Ebusy;
2293         return 1;
2294 Ebusy:
2295         return 0;
2296 }
2297
2298 struct nfs_sb_mountdata {
2299         struct nfs_server *server;
2300         int mntflags;
2301 };
2302
2303 static int nfs_set_super(struct super_block *s, void *data)
2304 {
2305         struct nfs_sb_mountdata *sb_mntdata = data;
2306         struct nfs_server *server = sb_mntdata->server;
2307         int ret;
2308
2309         s->s_flags = sb_mntdata->mntflags;
2310         s->s_fs_info = server;
2311         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2312         ret = set_anon_super(s, server);
2313         if (ret == 0)
2314                 server->s_dev = s->s_dev;
2315         return ret;
2316 }
2317
2318 static int nfs_compare_super_address(struct nfs_server *server1,
2319                                      struct nfs_server *server2)
2320 {
2321         struct sockaddr *sap1, *sap2;
2322
2323         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2324         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2325
2326         if (sap1->sa_family != sap2->sa_family)
2327                 return 0;
2328
2329         switch (sap1->sa_family) {
2330         case AF_INET: {
2331                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2332                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2333                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2334                         return 0;
2335                 if (sin1->sin_port != sin2->sin_port)
2336                         return 0;
2337                 break;
2338         }
2339         case AF_INET6: {
2340                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2341                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2342                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2343                         return 0;
2344                 if (sin1->sin6_port != sin2->sin6_port)
2345                         return 0;
2346                 break;
2347         }
2348         default:
2349                 return 0;
2350         }
2351
2352         return 1;
2353 }
2354
2355 static int nfs_compare_super(struct super_block *sb, void *data)
2356 {
2357         struct nfs_sb_mountdata *sb_mntdata = data;
2358         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2359         int mntflags = sb_mntdata->mntflags;
2360
2361         if (!nfs_compare_super_address(old, server))
2362                 return 0;
2363         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2364         if (old->flags & NFS_MOUNT_UNSHARED)
2365                 return 0;
2366         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2367                 return 0;
2368         return nfs_compare_mount_options(sb, server, mntflags);
2369 }
2370
2371 #ifdef CONFIG_NFS_FSCACHE
2372 static void nfs_get_cache_cookie(struct super_block *sb,
2373                                  struct nfs_parsed_mount_data *parsed,
2374                                  struct nfs_clone_mount *cloned)
2375 {
2376         char *uniq = NULL;
2377         int ulen = 0;
2378
2379         if (parsed && parsed->fscache_uniq) {
2380                 uniq = parsed->fscache_uniq;
2381                 ulen = strlen(parsed->fscache_uniq);
2382         } else if (cloned) {
2383                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2384                 if (mnt_s->fscache_key) {
2385                         uniq = mnt_s->fscache_key->key.uniquifier;
2386                         ulen = mnt_s->fscache_key->key.uniq_len;
2387                 };
2388         }
2389
2390         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2391 }
2392 #else
2393 static void nfs_get_cache_cookie(struct super_block *sb,
2394                                  struct nfs_parsed_mount_data *parsed,
2395                                  struct nfs_clone_mount *cloned)
2396 {
2397 }
2398 #endif
2399
2400 static int nfs_bdi_register(struct nfs_server *server)
2401 {
2402         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2403 }
2404
2405 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2406                         struct nfs_mount_info *mount_info)
2407 {
2408         return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2409 }
2410 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2411
2412 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2413                           struct nfs_mount_info *mount_info)
2414 {
2415         /* clone any lsm security options from the parent to the new sb */
2416         security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2417         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2418                 return -ESTALE;
2419         return 0;
2420 }
2421 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2422
2423 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2424                                    int flags, const char *dev_name,
2425                                    struct nfs_mount_info *mount_info,
2426                                    struct nfs_subversion *nfs_mod)
2427 {
2428         struct super_block *s;
2429         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2430         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2431         struct nfs_sb_mountdata sb_mntdata = {
2432                 .mntflags = flags,
2433                 .server = server,
2434         };
2435         int error;
2436
2437         if (server->flags & NFS_MOUNT_UNSHARED)
2438                 compare_super = NULL;
2439
2440         /* -o noac implies -o sync */
2441         if (server->flags & NFS_MOUNT_NOAC)
2442                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2443
2444         /* Get a superblock - note that we may end up sharing one that already exists */
2445         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2446         if (IS_ERR(s)) {
2447                 mntroot = ERR_CAST(s);
2448                 goto out_err_nosb;
2449         }
2450
2451         if (s->s_fs_info != server) {
2452                 nfs_free_server(server);
2453                 server = NULL;
2454         } else {
2455                 error = nfs_bdi_register(server);
2456                 if (error) {
2457                         mntroot = ERR_PTR(error);
2458                         goto error_splat_bdi;
2459                 }
2460         }
2461
2462         if (!s->s_root) {
2463                 /* initial superblock/root creation */
2464                 mount_info->fill_super(s, mount_info);
2465                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2466         }
2467
2468         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2469         if (IS_ERR(mntroot))
2470                 goto error_splat_super;
2471
2472         error = mount_info->set_security(s, mntroot, mount_info);
2473         if (error)
2474                 goto error_splat_root;
2475
2476         s->s_flags |= MS_ACTIVE;
2477
2478 out:
2479         return mntroot;
2480
2481 out_err_nosb:
2482         nfs_free_server(server);
2483         goto out;
2484
2485 error_splat_root:
2486         dput(mntroot);
2487         mntroot = ERR_PTR(error);
2488 error_splat_super:
2489         if (server && !s->s_root)
2490                 bdi_unregister(&server->backing_dev_info);
2491 error_splat_bdi:
2492         deactivate_locked_super(s);
2493         goto out;
2494 }
2495 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2496
2497 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2498         int flags, const char *dev_name, void *raw_data)
2499 {
2500         struct nfs_mount_info mount_info = {
2501                 .fill_super = nfs_fill_super,
2502                 .set_security = nfs_set_sb_security,
2503         };
2504         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2505         struct nfs_subversion *nfs_mod;
2506         int error;
2507
2508         mount_info.parsed = nfs_alloc_parsed_mount_data();
2509         mount_info.mntfh = nfs_alloc_fhandle();
2510         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2511                 goto out;
2512
2513         /* Validate the mount data */
2514         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2515         if (error == NFS_TEXT_DATA)
2516                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2517         if (error < 0) {
2518                 mntroot = ERR_PTR(error);
2519                 goto out;
2520         }
2521
2522         nfs_mod = get_nfs_version(mount_info.parsed->version);
2523         if (IS_ERR(nfs_mod)) {
2524                 mntroot = ERR_CAST(nfs_mod);
2525                 goto out;
2526         }
2527
2528         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2529
2530         put_nfs_version(nfs_mod);
2531 out:
2532         nfs_free_parsed_mount_data(mount_info.parsed);
2533         nfs_free_fhandle(mount_info.mntfh);
2534         return mntroot;
2535 }
2536 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2537
2538 /*
2539  * Ensure that we unregister the bdi before kill_anon_super
2540  * releases the device name
2541  */
2542 void nfs_put_super(struct super_block *s)
2543 {
2544         struct nfs_server *server = NFS_SB(s);
2545
2546         bdi_unregister(&server->backing_dev_info);
2547 }
2548 EXPORT_SYMBOL_GPL(nfs_put_super);
2549
2550 /*
2551  * Destroy an NFS2/3 superblock
2552  */
2553 void nfs_kill_super(struct super_block *s)
2554 {
2555         struct nfs_server *server = NFS_SB(s);
2556
2557         kill_anon_super(s);
2558         nfs_fscache_release_super_cookie(s);
2559         nfs_free_server(server);
2560 }
2561 EXPORT_SYMBOL_GPL(nfs_kill_super);
2562
2563 /*
2564  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2565  */
2566 static struct dentry *
2567 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2568                 const char *dev_name, void *raw_data)
2569 {
2570         struct nfs_clone_mount *data = raw_data;
2571         struct nfs_mount_info mount_info = {
2572                 .fill_super = nfs_clone_super,
2573                 .set_security = nfs_clone_sb_security,
2574                 .cloned = data,
2575         };
2576         struct nfs_server *server;
2577         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2578         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2579         int error;
2580
2581         dprintk("--> nfs_xdev_mount_common()\n");
2582
2583         mount_info.mntfh = mount_info.cloned->fh;
2584
2585         /* create a new volume representation */
2586         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2587         if (IS_ERR(server)) {
2588                 error = PTR_ERR(server);
2589                 goto out_err;
2590         }
2591
2592         mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, nfs_mod);
2593         dprintk("<-- nfs_xdev_mount_common() = 0\n");
2594 out:
2595         return mntroot;
2596
2597 out_err:
2598         dprintk("<-- nfs_xdev_mount_common() = %d [error]\n", error);
2599         goto out;
2600 }
2601
2602 #if IS_ENABLED(CONFIG_NFS_V4)
2603
2604 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2605 {
2606         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2607                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2608 }
2609
2610 /*
2611  * Validate NFSv4 mount options
2612  */
2613 static int nfs4_validate_mount_data(void *options,
2614                                     struct nfs_parsed_mount_data *args,
2615                                     const char *dev_name)
2616 {
2617         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2618         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2619         char *c;
2620
2621         if (data == NULL)
2622                 goto out_no_data;
2623
2624         args->version = 4;
2625
2626         switch (data->version) {
2627         case 1:
2628                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2629                         goto out_no_address;
2630                 if (data->host_addrlen == 0)
2631                         goto out_no_address;
2632                 args->nfs_server.addrlen = data->host_addrlen;
2633                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2634                         return -EFAULT;
2635                 if (!nfs_verify_server_address(sap))
2636                         goto out_no_address;
2637                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2638
2639                 if (data->auth_flavourlen) {
2640                         if (data->auth_flavourlen > 1)
2641                                 goto out_inval_auth;
2642                         if (copy_from_user(&args->auth_flavors[0],
2643                                            data->auth_flavours,
2644                                            sizeof(args->auth_flavors[0])))
2645                                 return -EFAULT;
2646                 }
2647
2648                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2649                 if (IS_ERR(c))
2650                         return PTR_ERR(c);
2651                 args->nfs_server.hostname = c;
2652
2653                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2654                 if (IS_ERR(c))
2655                         return PTR_ERR(c);
2656                 args->nfs_server.export_path = c;
2657                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2658
2659                 c = strndup_user(data->client_addr.data, 16);
2660                 if (IS_ERR(c))
2661                         return PTR_ERR(c);
2662                 args->client_address = c;
2663
2664                 /*
2665                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2666                  * can deal with.
2667                  */
2668
2669                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2670                 args->rsize     = data->rsize;
2671                 args->wsize     = data->wsize;
2672                 args->timeo     = data->timeo;
2673                 args->retrans   = data->retrans;
2674                 args->acregmin  = data->acregmin;
2675                 args->acregmax  = data->acregmax;
2676                 args->acdirmin  = data->acdirmin;
2677                 args->acdirmax  = data->acdirmax;
2678                 args->nfs_server.protocol = data->proto;
2679                 nfs_validate_transport_protocol(args);
2680
2681                 break;
2682         default:
2683                 return NFS_TEXT_DATA;
2684         }
2685
2686         return 0;
2687
2688 out_no_data:
2689         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2690         return -EINVAL;
2691
2692 out_inval_auth:
2693         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2694                  data->auth_flavourlen);
2695         return -EINVAL;
2696
2697 out_no_address:
2698         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2699         return -EINVAL;
2700 }
2701
2702 /*
2703  * NFS v4 module parameters need to stay in the
2704  * NFS client for backwards compatibility
2705  */
2706 unsigned int nfs_callback_set_tcpport;
2707 unsigned short nfs_callback_tcpport;
2708 /* Default cache timeout is 10 minutes */
2709 unsigned int nfs_idmap_cache_timeout = 600;
2710 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2711 bool nfs4_disable_idmapping = true;
2712 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2713 unsigned short send_implementation_id = 1;
2714 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2715
2716 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2717 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2718 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2719 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2720 EXPORT_SYMBOL_GPL(max_session_slots);
2721 EXPORT_SYMBOL_GPL(send_implementation_id);
2722 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2723
2724 #define NFS_CALLBACK_MAXPORTNR (65535U)
2725
2726 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2727 {
2728         unsigned long num;
2729         int ret;
2730
2731         if (!val)
2732                 return -EINVAL;
2733         ret = kstrtoul(val, 0, &num);
2734         if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2735                 return -EINVAL;
2736         *((unsigned int *)kp->arg) = num;
2737         return 0;
2738 }
2739 static struct kernel_param_ops param_ops_portnr = {
2740         .set = param_set_portnr,
2741         .get = param_get_uint,
2742 };
2743 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2744
2745 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2746 module_param(nfs_idmap_cache_timeout, int, 0644);
2747 module_param(nfs4_disable_idmapping, bool, 0644);
2748 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2749                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2750 MODULE_PARM_DESC(nfs4_disable_idmapping,
2751                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2752 module_param(max_session_slots, ushort, 0644);
2753 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2754                 "requests the client will negotiate");
2755 module_param(send_implementation_id, ushort, 0644);
2756 MODULE_PARM_DESC(send_implementation_id,
2757                 "Send implementation ID with NFSv4.1 exchange_id");
2758 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2759 MODULE_ALIAS("nfs4");
2760
2761 #endif /* CONFIG_NFS_V4 */