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
  57 #include <asm/system.h>
  58 #include <asm/uaccess.h>
  59
  60 #include "nfs4_fs.h"
  61 #include "callback.h"
  62 #include "delegation.h"
  63 #include "iostat.h"
  64 #include "internal.h"
  65 #include "fscache.h"
  66 #include "pnfs.h"
  67
  68 #define NFSDBG_FACILITY         NFSDBG_VFS
  69
  70 #ifdef CONFIG_NFS_V3
  71 #define NFS_DEFAULT_VERSION 3
  72 #else
  73 #define NFS_DEFAULT_VERSION 2
  74 #endif
  75
  76 enum {
  77         /* Mount options that take no arguments */
  78         Opt_soft, Opt_hard,
  79         Opt_posix, Opt_noposix,
  80         Opt_cto, Opt_nocto,
  81         Opt_ac, Opt_noac,
  82         Opt_lock, Opt_nolock,
  83         Opt_v2, Opt_v3, Opt_v4, Opt_v4_0, Opt_v4_1,
  84         Opt_udp, Opt_tcp, Opt_rdma,
  85         Opt_acl, Opt_noacl,
  86         Opt_rdirplus, Opt_nordirplus,
  87         Opt_sharecache, Opt_nosharecache,
  88         Opt_resvport, Opt_noresvport,
  89         Opt_fscache, Opt_nofscache,
  90
  91         /* Mount options that take integer arguments */
  92         Opt_port,
  93         Opt_rsize, Opt_wsize, Opt_bsize,
  94         Opt_timeo, Opt_retrans,
  95         Opt_acregmin, Opt_acregmax,
  96         Opt_acdirmin, Opt_acdirmax,
  97         Opt_actimeo,
  98         Opt_namelen,
  99         Opt_mountport,
 100         Opt_mountvers,
 101         Opt_nfsvers,
 102         Opt_minorversion,
 103
 104         /* Mount options that take string arguments */
 105         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 106         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 107         Opt_lookupcache,
 108         Opt_fscache_uniq,
 109         Opt_local_lock,
 110
 111         /* Special mount options */
 112         Opt_userspace, Opt_deprecated, Opt_sloppy,
 113
 114         Opt_err
 115 };
 116
 117 static const match_table_t nfs_mount_option_tokens = {
 118         { Opt_userspace, "bg" },
 119         { Opt_userspace, "fg" },
 120         { Opt_userspace, "retry=%s" },
 121
 122         { Opt_sloppy, "sloppy" },
 123
 124         { Opt_soft, "soft" },
 125         { Opt_hard, "hard" },
 126         { Opt_deprecated, "intr" },
 127         { Opt_deprecated, "nointr" },
 128         { Opt_posix, "posix" },
 129         { Opt_noposix, "noposix" },
 130         { Opt_cto, "cto" },
 131         { Opt_nocto, "nocto" },
 132         { Opt_ac, "ac" },
 133         { Opt_noac, "noac" },
 134         { Opt_lock, "lock" },
 135         { Opt_nolock, "nolock" },
 136         { Opt_v2, "v2" },
 137         { Opt_v3, "v3" },
 138         { Opt_v4, "v4" },
 139         { Opt_v4_0, "v4.0" },
 140         { Opt_v4_1, "v4.1" },
 141         { Opt_udp, "udp" },
 142         { Opt_tcp, "tcp" },
 143         { Opt_rdma, "rdma" },
 144         { Opt_acl, "acl" },
 145         { Opt_noacl, "noacl" },
 146         { Opt_rdirplus, "rdirplus" },
 147         { Opt_nordirplus, "nordirplus" },
 148         { Opt_sharecache, "sharecache" },
 149         { Opt_nosharecache, "nosharecache" },
 150         { Opt_resvport, "resvport" },
 151         { Opt_noresvport, "noresvport" },
 152         { Opt_fscache, "fsc" },
 153         { Opt_nofscache, "nofsc" },
 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_nfsvers, "nfsvers=%s" },
 170         { Opt_nfsvers, "vers=%s" },
 171         { Opt_minorversion, "minorversion=%s" },
 172
 173         { Opt_sec, "sec=%s" },
 174         { Opt_proto, "proto=%s" },
 175         { Opt_mountproto, "mountproto=%s" },
 176         { Opt_addr, "addr=%s" },
 177         { Opt_clientaddr, "clientaddr=%s" },
 178         { Opt_mounthost, "mounthost=%s" },
 179         { Opt_mountaddr, "mountaddr=%s" },
 180
 181         { Opt_lookupcache, "lookupcache=%s" },
 182         { Opt_fscache_uniq, "fsc=%s" },
 183         { Opt_local_lock, "local_lock=%s" },
 184
 185         { Opt_err, NULL }
 186 };
 187
 188 enum {
 189         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 190
 191         Opt_xprt_err
 192 };
 193
 194 static const match_table_t nfs_xprt_protocol_tokens = {
 195         { Opt_xprt_udp, "udp" },
 196         { Opt_xprt_udp6, "udp6" },
 197         { Opt_xprt_tcp, "tcp" },
 198         { Opt_xprt_tcp6, "tcp6" },
 199         { Opt_xprt_rdma, "rdma" },
 200
 201         { Opt_xprt_err, NULL }
 202 };
 203
 204 enum {
 205         Opt_sec_none, Opt_sec_sys,
 206         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 207         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 208         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 209
 210         Opt_sec_err
 211 };
 212
 213 static const match_table_t nfs_secflavor_tokens = {
 214         { Opt_sec_none, "none" },
 215         { Opt_sec_none, "null" },
 216         { Opt_sec_sys, "sys" },
 217
 218         { Opt_sec_krb5, "krb5" },
 219         { Opt_sec_krb5i, "krb5i" },
 220         { Opt_sec_krb5p, "krb5p" },
 221
 222         { Opt_sec_lkey, "lkey" },
 223         { Opt_sec_lkeyi, "lkeyi" },
 224         { Opt_sec_lkeyp, "lkeyp" },
 225
 226         { Opt_sec_spkm, "spkm3" },
 227         { Opt_sec_spkmi, "spkm3i" },
 228         { Opt_sec_spkmp, "spkm3p" },
 229
 230         { Opt_sec_err, NULL }
 231 };
 232
 233 enum {
 234         Opt_lookupcache_all, Opt_lookupcache_positive,
 235         Opt_lookupcache_none,
 236
 237         Opt_lookupcache_err
 238 };
 239
 240 static match_table_t nfs_lookupcache_tokens = {
 241         { Opt_lookupcache_all, "all" },
 242         { Opt_lookupcache_positive, "pos" },
 243         { Opt_lookupcache_positive, "positive" },
 244         { Opt_lookupcache_none, "none" },
 245
 246         { Opt_lookupcache_err, NULL }
 247 };
 248
 249 enum {
 250         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 251         Opt_local_lock_none,
 252
 253         Opt_local_lock_err
 254 };
 255
 256 static match_table_t nfs_local_lock_tokens = {
 257         { Opt_local_lock_all, "all" },
 258         { Opt_local_lock_flock, "flock" },
 259         { Opt_local_lock_posix, "posix" },
 260         { Opt_local_lock_none, "none" },
 261
 262         { Opt_local_lock_err, NULL }
 263 };
 264
 265
 266 static void nfs_umount_begin(struct super_block *);
 267 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 268 static int  nfs_show_options(struct seq_file *, struct dentry *);
 269 static int  nfs_show_devname(struct seq_file *, struct dentry *);
 270 static int  nfs_show_path(struct seq_file *, struct dentry *);
 271 static int  nfs_show_stats(struct seq_file *, struct dentry *);
 272 static struct dentry *nfs_fs_mount(struct file_system_type *,
 273                 int, const char *, void *);
 274 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 275                 int flags, const char *dev_name, void *raw_data);
 276 static void nfs_put_super(struct super_block *);
 277 static void nfs_kill_super(struct super_block *);
 278 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 279
 280 static struct file_system_type nfs_fs_type = {
 281         .owner          = THIS_MODULE,
 282         .name           = "nfs",
 283         .mount          = nfs_fs_mount,
 284         .kill_sb        = nfs_kill_super,
 285         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 286 };
 287
 288 struct file_system_type nfs_xdev_fs_type = {
 289         .owner          = THIS_MODULE,
 290         .name           = "nfs",
 291         .mount          = nfs_xdev_mount,
 292         .kill_sb        = nfs_kill_super,
 293         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 294 };
 295
 296 static const struct super_operations nfs_sops = {
 297         .alloc_inode    = nfs_alloc_inode,
 298         .destroy_inode  = nfs_destroy_inode,
 299         .write_inode    = nfs_write_inode,
 300         .put_super      = nfs_put_super,
 301         .statfs         = nfs_statfs,
 302         .evict_inode    = nfs_evict_inode,
 303         .umount_begin   = nfs_umount_begin,
 304         .show_options   = nfs_show_options,
 305         .show_devname   = nfs_show_devname,
 306         .show_path      = nfs_show_path,
 307         .show_stats     = nfs_show_stats,
 308         .remount_fs     = nfs_remount,
 309 };
 310
 311 #ifdef CONFIG_NFS_V4
 312 static int nfs4_validate_text_mount_data(void *options,
 313         struct nfs_parsed_mount_data *args, const char *dev_name);
 314 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 315         struct nfs_parsed_mount_data *data);
 316 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
 317         int flags, const char *dev_name, void *raw_data);
 318 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 319         int flags, const char *dev_name, void *raw_data);
 320 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
 321         int flags, const char *dev_name, void *raw_data);
 322 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 323         int flags, const char *dev_name, void *raw_data);
 324 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 325         int flags, const char *dev_name, void *raw_data);
 326 static void nfs4_kill_super(struct super_block *sb);
 327
 328 static struct file_system_type nfs4_fs_type = {
 329         .owner          = THIS_MODULE,
 330         .name           = "nfs4",
 331         .mount          = nfs4_mount,
 332         .kill_sb        = nfs4_kill_super,
 333         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 334 };
 335
 336 static struct file_system_type nfs4_remote_fs_type = {
 337         .owner          = THIS_MODULE,
 338         .name           = "nfs4",
 339         .mount          = nfs4_remote_mount,
 340         .kill_sb        = nfs4_kill_super,
 341         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 342 };
 343
 344 struct file_system_type nfs4_xdev_fs_type = {
 345         .owner          = THIS_MODULE,
 346         .name           = "nfs4",
 347         .mount          = nfs4_xdev_mount,
 348         .kill_sb        = nfs4_kill_super,
 349         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 350 };
 351
 352 static struct file_system_type nfs4_remote_referral_fs_type = {
 353         .owner          = THIS_MODULE,
 354         .name           = "nfs4",
 355         .mount          = nfs4_remote_referral_mount,
 356         .kill_sb        = nfs4_kill_super,
 357         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 358 };
 359
 360 struct file_system_type nfs4_referral_fs_type = {
 361         .owner          = THIS_MODULE,
 362         .name           = "nfs4",
 363         .mount          = nfs4_referral_mount,
 364         .kill_sb        = nfs4_kill_super,
 365         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 366 };
 367
 368 static const struct super_operations nfs4_sops = {
 369         .alloc_inode    = nfs_alloc_inode,
 370         .destroy_inode  = nfs_destroy_inode,
 371         .write_inode    = nfs_write_inode,
 372         .put_super      = nfs_put_super,
 373         .statfs         = nfs_statfs,
 374         .evict_inode    = nfs4_evict_inode,
 375         .umount_begin   = nfs_umount_begin,
 376         .show_options   = nfs_show_options,
 377         .show_devname   = nfs_show_devname,
 378         .show_path      = nfs_show_path,
 379         .show_stats     = nfs_show_stats,
 380         .remount_fs     = nfs_remount,
 381 };
 382 #endif
 383
 384 static struct shrinker acl_shrinker = {
 385         .shrink         = nfs_access_cache_shrinker,
 386         .seeks          = DEFAULT_SEEKS,
 387 };
 388
 389 /*
 390  * Register the NFS filesystems
 391  */
 392 int __init register_nfs_fs(void)
 393 {
 394         int ret;
 395
 396         ret = register_filesystem(&nfs_fs_type);
 397         if (ret < 0)
 398                 goto error_0;
 399
 400         ret = nfs_register_sysctl();
 401         if (ret < 0)
 402                 goto error_1;
 403 #ifdef CONFIG_NFS_V4
 404         ret = register_filesystem(&nfs4_fs_type);
 405         if (ret < 0)
 406                 goto error_2;
 407 #endif
 408         register_shrinker(&acl_shrinker);
 409         return 0;
 410
 411 #ifdef CONFIG_NFS_V4
 412 error_2:
 413         nfs_unregister_sysctl();
 414 #endif
 415 error_1:
 416         unregister_filesystem(&nfs_fs_type);
 417 error_0:
 418         return ret;
 419 }
 420
 421 /*
 422  * Unregister the NFS filesystems
 423  */
 424 void __exit unregister_nfs_fs(void)
 425 {
 426         unregister_shrinker(&acl_shrinker);
 427 #ifdef CONFIG_NFS_V4
 428         unregister_filesystem(&nfs4_fs_type);
 429 #endif
 430         nfs_unregister_sysctl();
 431         unregister_filesystem(&nfs_fs_type);
 432 }
 433
 434 void nfs_sb_active(struct super_block *sb)
 435 {
 436         struct nfs_server *server = NFS_SB(sb);
 437
 438         if (atomic_inc_return(&server->active) == 1)
 439                 atomic_inc(&sb->s_active);
 440 }
 441
 442 void nfs_sb_deactive(struct super_block *sb)
 443 {
 444         struct nfs_server *server = NFS_SB(sb);
 445
 446         if (atomic_dec_and_test(&server->active))
 447                 deactivate_super(sb);
 448 }
 449
 450 /*
 451  * Deliver file system statistics to userspace
 452  */
 453 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 454 {
 455         struct nfs_server *server = NFS_SB(dentry->d_sb);
 456         unsigned char blockbits;
 457         unsigned long blockres;
 458         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 459         struct nfs_fsstat res;
 460         int error = -ENOMEM;
 461
 462         res.fattr = nfs_alloc_fattr();
 463         if (res.fattr == NULL)
 464                 goto out_err;
 465
 466         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 467         if (unlikely(error == -ESTALE)) {
 468                 struct dentry *pd_dentry;
 469
 470                 pd_dentry = dget_parent(dentry);
 471                 if (pd_dentry != NULL) {
 472                         nfs_zap_caches(pd_dentry->d_inode);
 473                         dput(pd_dentry);
 474                 }
 475         }
 476         nfs_free_fattr(res.fattr);
 477         if (error < 0)
 478                 goto out_err;
 479
 480         buf->f_type = NFS_SUPER_MAGIC;
 481
 482         /*
 483          * Current versions of glibc do not correctly handle the
 484          * case where f_frsize != f_bsize.  Eventually we want to
 485          * report the value of wtmult in this field.
 486          */
 487         buf->f_frsize = dentry->d_sb->s_blocksize;
 488
 489         /*
 490          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 491          * are reported in units of f_frsize.  Linux hasn't had
 492          * an f_frsize field in its statfs struct until recently,
 493          * thus historically Linux's sys_statfs reports these
 494          * fields in units of f_bsize.
 495          */
 496         buf->f_bsize = dentry->d_sb->s_blocksize;
 497         blockbits = dentry->d_sb->s_blocksize_bits;
 498         blockres = (1 << blockbits) - 1;
 499         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 500         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 501         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 502
 503         buf->f_files = res.tfiles;
 504         buf->f_ffree = res.afiles;
 505
 506         buf->f_namelen = server->namelen;
 507
 508         return 0;
 509
 510  out_err:
 511         dprintk("%s: statfs error = %d\n", __func__, -error);
 512         return error;
 513 }
 514
 515 /*
 516  * Map the security flavour number to a name
 517  */
 518 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 519 {
 520         static const struct {
 521                 rpc_authflavor_t flavour;
 522                 const char *str;
 523         } sec_flavours[] = {
 524                 { RPC_AUTH_NULL, "null" },
 525                 { RPC_AUTH_UNIX, "sys" },
 526                 { RPC_AUTH_GSS_KRB5, "krb5" },
 527                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 528                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 529                 { RPC_AUTH_GSS_LKEY, "lkey" },
 530                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 531                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 532                 { RPC_AUTH_GSS_SPKM, "spkm" },
 533                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 534                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 535                 { UINT_MAX, "unknown" }
 536         };
 537         int i;
 538
 539         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 540                 if (sec_flavours[i].flavour == flavour)
 541                         break;
 542         }
 543         return sec_flavours[i].str;
 544 }
 545
 546 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 547                                   int showdefaults)
 548 {
 549         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 550
 551         seq_printf(m, ",mountproto=");
 552         switch (sap->sa_family) {
 553         case AF_INET:
 554                 switch (nfss->mountd_protocol) {
 555                 case IPPROTO_UDP:
 556                         seq_printf(m, RPCBIND_NETID_UDP);
 557                         break;
 558                 case IPPROTO_TCP:
 559                         seq_printf(m, RPCBIND_NETID_TCP);
 560                         break;
 561                 default:
 562                         if (showdefaults)
 563                                 seq_printf(m, "auto");
 564                 }
 565                 break;
 566         case AF_INET6:
 567                 switch (nfss->mountd_protocol) {
 568                 case IPPROTO_UDP:
 569                         seq_printf(m, RPCBIND_NETID_UDP6);
 570                         break;
 571                 case IPPROTO_TCP:
 572                         seq_printf(m, RPCBIND_NETID_TCP6);
 573                         break;
 574                 default:
 575                         if (showdefaults)
 576                                 seq_printf(m, "auto");
 577                 }
 578                 break;
 579         default:
 580                 if (showdefaults)
 581                         seq_printf(m, "auto");
 582         }
 583 }
 584
 585 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 586                                     int showdefaults)
 587 {
 588         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 589
 590         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 591                 return;
 592
 593         switch (sap->sa_family) {
 594         case AF_INET: {
 595                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 596                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 597                 break;
 598         }
 599         case AF_INET6: {
 600                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 601                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 602                 break;
 603         }
 604         default:
 605                 if (showdefaults)
 606                         seq_printf(m, ",mountaddr=unspecified");
 607         }
 608
 609         if (nfss->mountd_version || showdefaults)
 610                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 611         if ((nfss->mountd_port &&
 612                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 613                 showdefaults)
 614                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 615
 616         nfs_show_mountd_netid(m, nfss, showdefaults);
 617 }
 618
 619 #ifdef CONFIG_NFS_V4
 620 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 621                                     int showdefaults)
 622 {
 623         struct nfs_client *clp = nfss->nfs_client;
 624
 625         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 626         seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
 627 }
 628 #else
 629 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 630                                     int showdefaults)
 631 {
 632 }
 633 #endif
 634
 635 /*
 636  * Describe the mount options in force on this server representation
 637  */
 638 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 639                                    int showdefaults)
 640 {
 641         static const struct proc_nfs_info {
 642                 int flag;
 643                 const char *str;
 644                 const char *nostr;
 645         } nfs_info[] = {
 646                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 647                 { NFS_MOUNT_POSIX, ",posix", "" },
 648                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 649                 { NFS_MOUNT_NOAC, ",noac", "" },
 650                 { NFS_MOUNT_NONLM, ",nolock", "" },
 651                 { NFS_MOUNT_NOACL, ",noacl", "" },
 652                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 653                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 654                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 655                 { 0, NULL, NULL }
 656         };
 657         const struct proc_nfs_info *nfs_infop;
 658         struct nfs_client *clp = nfss->nfs_client;
 659         u32 version = clp->rpc_ops->version;
 660         int local_flock, local_fcntl;
 661
 662         seq_printf(m, ",vers=%u", version);
 663         seq_printf(m, ",rsize=%u", nfss->rsize);
 664         seq_printf(m, ",wsize=%u", nfss->wsize);
 665         if (nfss->bsize != 0)
 666                 seq_printf(m, ",bsize=%u", nfss->bsize);
 667         seq_printf(m, ",namlen=%u", nfss->namelen);
 668         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 669                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 670         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 671                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 672         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 673                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 674         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 675                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 676         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 677                 if (nfss->flags & nfs_infop->flag)
 678                         seq_puts(m, nfs_infop->str);
 679                 else
 680                         seq_puts(m, nfs_infop->nostr);
 681         }
 682         seq_printf(m, ",proto=%s",
 683                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 684         if (version == 4) {
 685                 if (nfss->port != NFS_PORT)
 686                         seq_printf(m, ",port=%u", nfss->port);
 687         } else
 688                 if (nfss->port)
 689                         seq_printf(m, ",port=%u", nfss->port);
 690
 691         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 692         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 693         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 694
 695         if (version != 4)
 696                 nfs_show_mountd_options(m, nfss, showdefaults);
 697         else
 698                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 699
 700         if (nfss->options & NFS_OPTION_FSCACHE)
 701                 seq_printf(m, ",fsc");
 702
 703         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 704                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 705                         seq_printf(m, ",lookupcache=none");
 706                 else
 707                         seq_printf(m, ",lookupcache=pos");
 708         }
 709
 710         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 711         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 712
 713         if (!local_flock && !local_fcntl)
 714                 seq_printf(m, ",local_lock=none");
 715         else if (local_flock && local_fcntl)
 716                 seq_printf(m, ",local_lock=all");
 717         else if (local_flock)
 718                 seq_printf(m, ",local_lock=flock");
 719         else
 720                 seq_printf(m, ",local_lock=posix");
 721 }
 722
 723 /*
 724  * Describe the mount options on this VFS mountpoint
 725  */
 726 static int nfs_show_options(struct seq_file *m, struct dentry *root)
 727 {
 728         struct nfs_server *nfss = NFS_SB(root->d_sb);
 729
 730         nfs_show_mount_options(m, nfss, 0);
 731
 732         seq_printf(m, ",addr=%s",
 733                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 734                                                         RPC_DISPLAY_ADDR));
 735
 736         return 0;
 737 }
 738
 739 #ifdef CONFIG_NFS_V4
 740 #ifdef CONFIG_NFS_V4_1
 741 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 742 {
 743         if (nfs4_has_session(server->nfs_client))
 744                 seq_printf(m, ",sessions");
 745 }
 746 #else
 747 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 748 #endif
 749 #endif
 750
 751 #ifdef CONFIG_NFS_V4
 752 #ifdef CONFIG_NFS_V4_1
 753 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 754 {
 755         seq_printf(m, ",pnfs=");
 756         if (server->pnfs_curr_ld)
 757                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 758         else
 759                 seq_printf(m, "not configured");
 760 }
 761 #else
 762 static void show_pnfs(struct seq_file *m, struct nfs_server *server) {}
 763 #endif
 764 #endif
 765
 766 static int nfs_show_devname(struct seq_file *m, struct dentry *root)
 767 {
 768         char *page = (char *) __get_free_page(GFP_KERNEL);
 769         char *devname, *dummy;
 770         int err = 0;
 771         if (!page)
 772                 return -ENOMEM;
 773         devname = nfs_path(&dummy, root, page, PAGE_SIZE);
 774         if (IS_ERR(devname))
 775                 err = PTR_ERR(devname);
 776         else
 777                 seq_escape(m, devname, " \t\n\\");
 778         free_page((unsigned long)page);
 779         return err;
 780 }
 781
 782 static int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 783 {
 784         seq_puts(m, "/");
 785         return 0;
 786 }
 787
 788 /*
 789  * Present statistical information for this VFS mountpoint
 790  */
 791 static int nfs_show_stats(struct seq_file *m, struct dentry *root)
 792 {
 793         int i, cpu;
 794         struct nfs_server *nfss = NFS_SB(root->d_sb);
 795         struct rpc_auth *auth = nfss->client->cl_auth;
 796         struct nfs_iostats totals = { };
 797
 798         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 799
 800         /*
 801          * Display all mount option settings
 802          */
 803         seq_printf(m, "\n\topts:\t");
 804         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 805         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 806         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 807         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 808         nfs_show_mount_options(m, nfss, 1);
 809
 810         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 811
 812         if (nfss->nfs_client && nfss->nfs_client->impl_id) {
 813                 struct nfs41_impl_id *impl_id = nfss->nfs_client->impl_id;
 814                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 815                            "date='%llu,%u'",
 816                            impl_id->name, impl_id->domain,
 817                            impl_id->date.seconds, impl_id->date.nseconds);
 818         }
 819
 820         seq_printf(m, "\n\tcaps:\t");
 821         seq_printf(m, "caps=0x%x", nfss->caps);
 822         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 823         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 824         seq_printf(m, ",bsize=%u", nfss->bsize);
 825         seq_printf(m, ",namlen=%u", nfss->namelen);
 826
 827 #ifdef CONFIG_NFS_V4
 828         if (nfss->nfs_client->rpc_ops->version == 4) {
 829                 seq_printf(m, "\n\tnfsv4:\t");
 830                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 831                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 832                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 833                 show_sessions(m, nfss);
 834                 show_pnfs(m, nfss);
 835         }
 836 #endif
 837
 838         /*
 839          * Display security flavor in effect for this mount
 840          */
 841         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 842         if (auth->au_flavor)
 843                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 844
 845         /*
 846          * Display superblock I/O counters
 847          */
 848         for_each_possible_cpu(cpu) {
 849                 struct nfs_iostats *stats;
 850
 851                 preempt_disable();
 852                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 853
 854                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 855                         totals.events[i] += stats->events[i];
 856                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 857                         totals.bytes[i] += stats->bytes[i];
 858 #ifdef CONFIG_NFS_FSCACHE
 859                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 860                         totals.fscache[i] += stats->fscache[i];
 861 #endif
 862
 863                 preempt_enable();
 864         }
 865
 866         seq_printf(m, "\n\tevents:\t");
 867         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 868                 seq_printf(m, "%lu ", totals.events[i]);
 869         seq_printf(m, "\n\tbytes:\t");
 870         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 871                 seq_printf(m, "%Lu ", totals.bytes[i]);
 872 #ifdef CONFIG_NFS_FSCACHE
 873         if (nfss->options & NFS_OPTION_FSCACHE) {
 874                 seq_printf(m, "\n\tfsc:\t");
 875                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 876                         seq_printf(m, "%Lu ", totals.bytes[i]);
 877         }
 878 #endif
 879         seq_printf(m, "\n");
 880
 881         rpc_print_iostats(m, nfss->client);
 882
 883         return 0;
 884 }
 885
 886 /*
 887  * Begin unmount by attempting to remove all automounted mountpoints we added
 888  * in response to xdev traversals and referrals
 889  */
 890 static void nfs_umount_begin(struct super_block *sb)
 891 {
 892         struct nfs_server *server;
 893         struct rpc_clnt *rpc;
 894
 895         server = NFS_SB(sb);
 896         /* -EIO all pending I/O */
 897         rpc = server->client_acl;
 898         if (!IS_ERR(rpc))
 899                 rpc_killall_tasks(rpc);
 900         rpc = server->client;
 901         if (!IS_ERR(rpc))
 902                 rpc_killall_tasks(rpc);
 903 }
 904
 905 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 906 {
 907         struct nfs_parsed_mount_data *data;
 908
 909         data = kzalloc(sizeof(*data), GFP_KERNEL);
 910         if (data) {
 911                 data->acregmin          = NFS_DEF_ACREGMIN;
 912                 data->acregmax          = NFS_DEF_ACREGMAX;
 913                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 914                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 915                 data->mount_server.port = NFS_UNSPEC_PORT;
 916                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 917                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 918                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 919                 data->auth_flavor_len   = 1;
 920                 data->version           = version;
 921                 data->minorversion      = 0;
 922                 data->net               = current->nsproxy->net_ns;
 923                 security_init_mnt_opts(&data->lsm_opts);
 924         }
 925         return data;
 926 }
 927
 928 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 929 {
 930         if (data) {
 931                 kfree(data->client_address);
 932                 kfree(data->mount_server.hostname);
 933                 kfree(data->nfs_server.export_path);
 934                 kfree(data->nfs_server.hostname);
 935                 kfree(data->fscache_uniq);
 936                 security_free_mnt_opts(&data->lsm_opts);
 937                 kfree(data);
 938         }
 939 }
 940
 941 /*
 942  * Sanity-check a server address provided by the mount command.
 943  *
 944  * Address family must be initialized, and address must not be
 945  * the ANY address for that family.
 946  */
 947 static int nfs_verify_server_address(struct sockaddr *addr)
 948 {
 949         switch (addr->sa_family) {
 950         case AF_INET: {
 951                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 952                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 953         }
 954         case AF_INET6: {
 955                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 956                 return !ipv6_addr_any(sa);
 957         }
 958         }
 959
 960         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 961         return 0;
 962 }
 963
 964 /*
 965  * Select between a default port value and a user-specified port value.
 966  * If a zero value is set, then autobind will be used.
 967  */
 968 static void nfs_set_port(struct sockaddr *sap, int *port,
 969                                  const unsigned short default_port)
 970 {
 971         if (*port == NFS_UNSPEC_PORT)
 972                 *port = default_port;
 973
 974         rpc_set_port(sap, *port);
 975 }
 976
 977 /*
 978  * Sanity check the NFS transport protocol.
 979  *
 980  */
 981 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 982 {
 983         switch (mnt->nfs_server.protocol) {
 984         case XPRT_TRANSPORT_UDP:
 985         case XPRT_TRANSPORT_TCP:
 986         case XPRT_TRANSPORT_RDMA:
 987                 break;
 988         default:
 989                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 990         }
 991 }
 992
 993 /*
 994  * For text based NFSv2/v3 mounts, the mount protocol transport default
 995  * settings should depend upon the specified NFS transport.
 996  */
 997 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 998 {
 999         nfs_validate_transport_protocol(mnt);
1000
1001         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1002             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1003                         return;
1004         switch (mnt->nfs_server.protocol) {
1005         case XPRT_TRANSPORT_UDP:
1006                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1007                 break;
1008         case XPRT_TRANSPORT_TCP:
1009         case XPRT_TRANSPORT_RDMA:
1010                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1011         }
1012 }
1013
1014 /*
1015  * Parse the value of the 'sec=' option.
1016  */
1017 static int nfs_parse_security_flavors(char *value,
1018                                       struct nfs_parsed_mount_data *mnt)
1019 {
1020         substring_t args[MAX_OPT_ARGS];
1021
1022         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1023
1024         switch (match_token(value, nfs_secflavor_tokens, args)) {
1025         case Opt_sec_none:
1026                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1027                 break;
1028         case Opt_sec_sys:
1029                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1030                 break;
1031         case Opt_sec_krb5:
1032                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1033                 break;
1034         case Opt_sec_krb5i:
1035                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1036                 break;
1037         case Opt_sec_krb5p:
1038                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1039                 break;
1040         case Opt_sec_lkey:
1041                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1042                 break;
1043         case Opt_sec_lkeyi:
1044                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1045                 break;
1046         case Opt_sec_lkeyp:
1047                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1048                 break;
1049         case Opt_sec_spkm:
1050                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1051                 break;
1052         case Opt_sec_spkmi:
1053                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1054                 break;
1055         case Opt_sec_spkmp:
1056                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1057                 break;
1058         default:
1059                 return 0;
1060         }
1061
1062         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1063         mnt->auth_flavor_len = 1;
1064         return 1;
1065 }
1066
1067 static int nfs_get_option_str(substring_t args[], char **option)
1068 {
1069         kfree(*option);
1070         *option = match_strdup(args);
1071         return !option;
1072 }
1073
1074 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1075 {
1076         int rc;
1077         char *string;
1078
1079         string = match_strdup(args);
1080         if (string == NULL)
1081                 return -ENOMEM;
1082         rc = strict_strtoul(string, 10, option);
1083         kfree(string);
1084
1085         return rc;
1086 }
1087
1088 /*
1089  * Error-check and convert a string of mount options from user space into
1090  * a data structure.  The whole mount string is processed; bad options are
1091  * skipped as they are encountered.  If there were no errors, return 1;
1092  * otherwise return 0 (zero).
1093  */
1094 static int nfs_parse_mount_options(char *raw,
1095                                    struct nfs_parsed_mount_data *mnt)
1096 {
1097         char *p, *string, *secdata;
1098         int rc, sloppy = 0, invalid_option = 0;
1099         unsigned short protofamily = AF_UNSPEC;
1100         unsigned short mountfamily = AF_UNSPEC;
1101
1102         if (!raw) {
1103                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1104                 return 1;
1105         }
1106         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1107
1108         secdata = alloc_secdata();
1109         if (!secdata)
1110                 goto out_nomem;
1111
1112         rc = security_sb_copy_data(raw, secdata);
1113         if (rc)
1114                 goto out_security_failure;
1115
1116         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1117         if (rc)
1118                 goto out_security_failure;
1119
1120         free_secdata(secdata);
1121
1122         while ((p = strsep(&raw, ",")) != NULL) {
1123                 substring_t args[MAX_OPT_ARGS];
1124                 unsigned long option;
1125                 int token;
1126
1127                 if (!*p)
1128                         continue;
1129
1130                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1131
1132                 token = match_token(p, nfs_mount_option_tokens, args);
1133                 switch (token) {
1134
1135                 /*
1136                  * boolean options:  foo/nofoo
1137                  */
1138                 case Opt_soft:
1139                         mnt->flags |= NFS_MOUNT_SOFT;
1140                         break;
1141                 case Opt_hard:
1142                         mnt->flags &= ~NFS_MOUNT_SOFT;
1143                         break;
1144                 case Opt_posix:
1145                         mnt->flags |= NFS_MOUNT_POSIX;
1146                         break;
1147                 case Opt_noposix:
1148                         mnt->flags &= ~NFS_MOUNT_POSIX;
1149                         break;
1150                 case Opt_cto:
1151                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1152                         break;
1153                 case Opt_nocto:
1154                         mnt->flags |= NFS_MOUNT_NOCTO;
1155                         break;
1156                 case Opt_ac:
1157                         mnt->flags &= ~NFS_MOUNT_NOAC;
1158                         break;
1159                 case Opt_noac:
1160                         mnt->flags |= NFS_MOUNT_NOAC;
1161                         break;
1162                 case Opt_lock:
1163                         mnt->flags &= ~NFS_MOUNT_NONLM;
1164                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1165                                         NFS_MOUNT_LOCAL_FCNTL);
1166                         break;
1167                 case Opt_nolock:
1168                         mnt->flags |= NFS_MOUNT_NONLM;
1169                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1170                                        NFS_MOUNT_LOCAL_FCNTL);
1171                         break;
1172                 case Opt_v2:
1173                         mnt->flags &= ~NFS_MOUNT_VER3;
1174                         mnt->version = 2;
1175                         break;
1176                 case Opt_v3:
1177                         mnt->flags |= NFS_MOUNT_VER3;
1178                         mnt->version = 3;
1179                         break;
1180                 case Opt_v4:
1181                         mnt->flags &= ~NFS_MOUNT_VER3;
1182                         mnt->version = 4;
1183                         break;
1184                 case Opt_v4_0:
1185                         mnt->flags &= ~NFS_MOUNT_VER3;
1186                         mnt->version = 4;
1187                         mnt->minorversion = 0;
1188                         break;
1189                 case Opt_v4_1:
1190                         mnt->flags &= ~NFS_MOUNT_VER3;
1191                         mnt->version = 4;
1192                         mnt->minorversion = 1;
1193                         break;
1194                 case Opt_udp:
1195                         mnt->flags &= ~NFS_MOUNT_TCP;
1196                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1197                         break;
1198                 case Opt_tcp:
1199                         mnt->flags |= NFS_MOUNT_TCP;
1200                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1201                         break;
1202                 case Opt_rdma:
1203                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1204                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1205                         xprt_load_transport(p);
1206                         break;
1207                 case Opt_acl:
1208                         mnt->flags &= ~NFS_MOUNT_NOACL;
1209                         break;
1210                 case Opt_noacl:
1211                         mnt->flags |= NFS_MOUNT_NOACL;
1212                         break;
1213                 case Opt_rdirplus:
1214                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1215                         break;
1216                 case Opt_nordirplus:
1217                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1218                         break;
1219                 case Opt_sharecache:
1220                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1221                         break;
1222                 case Opt_nosharecache:
1223                         mnt->flags |= NFS_MOUNT_UNSHARED;
1224                         break;
1225                 case Opt_resvport:
1226                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1227                         break;
1228                 case Opt_noresvport:
1229                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1230                         break;
1231                 case Opt_fscache:
1232                         mnt->options |= NFS_OPTION_FSCACHE;
1233                         kfree(mnt->fscache_uniq);
1234                         mnt->fscache_uniq = NULL;
1235                         break;
1236                 case Opt_nofscache:
1237                         mnt->options &= ~NFS_OPTION_FSCACHE;
1238                         kfree(mnt->fscache_uniq);
1239                         mnt->fscache_uniq = NULL;
1240                         break;
1241
1242                 /*
1243                  * options that take numeric values
1244                  */
1245                 case Opt_port:
1246                         if (nfs_get_option_ul(args, &option) ||
1247                             option > USHRT_MAX)
1248                                 goto out_invalid_value;
1249                         mnt->nfs_server.port = option;
1250                         break;
1251                 case Opt_rsize:
1252                         if (nfs_get_option_ul(args, &option))
1253                                 goto out_invalid_value;
1254                         mnt->rsize = option;
1255                         break;
1256                 case Opt_wsize:
1257                         if (nfs_get_option_ul(args, &option))
1258                                 goto out_invalid_value;
1259                         mnt->wsize = option;
1260                         break;
1261                 case Opt_bsize:
1262                         if (nfs_get_option_ul(args, &option))
1263                                 goto out_invalid_value;
1264                         mnt->bsize = option;
1265                         break;
1266                 case Opt_timeo:
1267                         if (nfs_get_option_ul(args, &option) || option == 0)
1268                                 goto out_invalid_value;
1269                         mnt->timeo = option;
1270                         break;
1271                 case Opt_retrans:
1272                         if (nfs_get_option_ul(args, &option) || option == 0)
1273                                 goto out_invalid_value;
1274                         mnt->retrans = option;
1275                         break;
1276                 case Opt_acregmin:
1277                         if (nfs_get_option_ul(args, &option))
1278                                 goto out_invalid_value;
1279                         mnt->acregmin = option;
1280                         break;
1281                 case Opt_acregmax:
1282                         if (nfs_get_option_ul(args, &option))
1283                                 goto out_invalid_value;
1284                         mnt->acregmax = option;
1285                         break;
1286                 case Opt_acdirmin:
1287                         if (nfs_get_option_ul(args, &option))
1288                                 goto out_invalid_value;
1289                         mnt->acdirmin = option;
1290                         break;
1291                 case Opt_acdirmax:
1292                         if (nfs_get_option_ul(args, &option))
1293                                 goto out_invalid_value;
1294                         mnt->acdirmax = option;
1295                         break;
1296                 case Opt_actimeo:
1297                         if (nfs_get_option_ul(args, &option))
1298                                 goto out_invalid_value;
1299                         mnt->acregmin = mnt->acregmax =
1300                         mnt->acdirmin = mnt->acdirmax = option;
1301                         break;
1302                 case Opt_namelen:
1303                         if (nfs_get_option_ul(args, &option))
1304                                 goto out_invalid_value;
1305                         mnt->namlen = option;
1306                         break;
1307                 case Opt_mountport:
1308                         if (nfs_get_option_ul(args, &option) ||
1309                             option > USHRT_MAX)
1310                                 goto out_invalid_value;
1311                         mnt->mount_server.port = option;
1312                         break;
1313                 case Opt_mountvers:
1314                         if (nfs_get_option_ul(args, &option) ||
1315                             option < NFS_MNT_VERSION ||
1316                             option > NFS_MNT3_VERSION)
1317                                 goto out_invalid_value;
1318                         mnt->mount_server.version = option;
1319                         break;
1320                 case Opt_nfsvers:
1321                         if (nfs_get_option_ul(args, &option))
1322                                 goto out_invalid_value;
1323                         switch (option) {
1324                         case NFS2_VERSION:
1325                                 mnt->flags &= ~NFS_MOUNT_VER3;
1326                                 mnt->version = 2;
1327                                 break;
1328                         case NFS3_VERSION:
1329                                 mnt->flags |= NFS_MOUNT_VER3;
1330                                 mnt->version = 3;
1331                                 break;
1332                         case NFS4_VERSION:
1333                                 mnt->flags &= ~NFS_MOUNT_VER3;
1334                                 mnt->version = 4;
1335                                 break;
1336                         default:
1337                                 goto out_invalid_value;
1338                         }
1339                         break;
1340                 case Opt_minorversion:
1341                         if (nfs_get_option_ul(args, &option))
1342                                 goto out_invalid_value;
1343                         if (option > NFS4_MAX_MINOR_VERSION)
1344                                 goto out_invalid_value;
1345                         mnt->minorversion = option;
1346                         break;
1347
1348                 /*
1349                  * options that take text values
1350                  */
1351                 case Opt_sec:
1352                         string = match_strdup(args);
1353                         if (string == NULL)
1354                                 goto out_nomem;
1355                         rc = nfs_parse_security_flavors(string, mnt);
1356                         kfree(string);
1357                         if (!rc) {
1358                                 dfprintk(MOUNT, "NFS:   unrecognized "
1359                                                 "security flavor\n");
1360                                 return 0;
1361                         }
1362                         break;
1363                 case Opt_proto:
1364                         string = match_strdup(args);
1365                         if (string == NULL)
1366                                 goto out_nomem;
1367                         token = match_token(string,
1368                                             nfs_xprt_protocol_tokens, args);
1369
1370                         protofamily = AF_INET;
1371                         switch (token) {
1372                         case Opt_xprt_udp6:
1373                                 protofamily = AF_INET6;
1374                         case Opt_xprt_udp:
1375                                 mnt->flags &= ~NFS_MOUNT_TCP;
1376                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1377                                 break;
1378                         case Opt_xprt_tcp6:
1379                                 protofamily = AF_INET6;
1380                         case Opt_xprt_tcp:
1381                                 mnt->flags |= NFS_MOUNT_TCP;
1382                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1383                                 break;
1384                         case Opt_xprt_rdma:
1385                                 /* vector side protocols to TCP */
1386                                 mnt->flags |= NFS_MOUNT_TCP;
1387                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1388                                 xprt_load_transport(string);
1389                                 break;
1390                         default:
1391                                 dfprintk(MOUNT, "NFS:   unrecognized "
1392                                                 "transport protocol\n");
1393                                 kfree(string);
1394                                 return 0;
1395                         }
1396                         kfree(string);
1397                         break;
1398                 case Opt_mountproto:
1399                         string = match_strdup(args);
1400                         if (string == NULL)
1401                                 goto out_nomem;
1402                         token = match_token(string,
1403                                             nfs_xprt_protocol_tokens, args);
1404                         kfree(string);
1405
1406                         mountfamily = AF_INET;
1407                         switch (token) {
1408                         case Opt_xprt_udp6:
1409                                 mountfamily = AF_INET6;
1410                         case Opt_xprt_udp:
1411                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1412                                 break;
1413                         case Opt_xprt_tcp6:
1414                                 mountfamily = AF_INET6;
1415                         case Opt_xprt_tcp:
1416                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1417                                 break;
1418                         case Opt_xprt_rdma: /* not used for side protocols */
1419                         default:
1420                                 dfprintk(MOUNT, "NFS:   unrecognized "
1421                                                 "transport protocol\n");
1422                                 return 0;
1423                         }
1424                         break;
1425                 case Opt_addr:
1426                         string = match_strdup(args);
1427                         if (string == NULL)
1428                                 goto out_nomem;
1429                         mnt->nfs_server.addrlen =
1430                                 rpc_pton(mnt->net, string, strlen(string),
1431                                         (struct sockaddr *)
1432                                         &mnt->nfs_server.address,
1433                                         sizeof(mnt->nfs_server.address));
1434                         kfree(string);
1435                         if (mnt->nfs_server.addrlen == 0)
1436                                 goto out_invalid_address;
1437                         break;
1438                 case Opt_clientaddr:
1439                         if (nfs_get_option_str(args, &mnt->client_address))
1440                                 goto out_nomem;
1441                         break;
1442                 case Opt_mounthost:
1443                         if (nfs_get_option_str(args,
1444                                                &mnt->mount_server.hostname))
1445                                 goto out_nomem;
1446                         break;
1447                 case Opt_mountaddr:
1448                         string = match_strdup(args);
1449                         if (string == NULL)
1450                                 goto out_nomem;
1451                         mnt->mount_server.addrlen =
1452                                 rpc_pton(mnt->net, string, strlen(string),
1453                                         (struct sockaddr *)
1454                                         &mnt->mount_server.address,
1455                                         sizeof(mnt->mount_server.address));
1456                         kfree(string);
1457                         if (mnt->mount_server.addrlen == 0)
1458                                 goto out_invalid_address;
1459                         break;
1460                 case Opt_lookupcache:
1461                         string = match_strdup(args);
1462                         if (string == NULL)
1463                                 goto out_nomem;
1464                         token = match_token(string,
1465                                         nfs_lookupcache_tokens, args);
1466                         kfree(string);
1467                         switch (token) {
1468                                 case Opt_lookupcache_all:
1469                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1470                                         break;
1471                                 case Opt_lookupcache_positive:
1472                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1473                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1474                                         break;
1475                                 case Opt_lookupcache_none:
1476                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1477                                         break;
1478                                 default:
1479                                         dfprintk(MOUNT, "NFS:   invalid "
1480                                                         "lookupcache argument\n");
1481                                         return 0;
1482                         };
1483                         break;
1484                 case Opt_fscache_uniq:
1485                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1486                                 goto out_nomem;
1487                         mnt->options |= NFS_OPTION_FSCACHE;
1488                         break;
1489                 case Opt_local_lock:
1490                         string = match_strdup(args);
1491                         if (string == NULL)
1492                                 goto out_nomem;
1493                         token = match_token(string, nfs_local_lock_tokens,
1494                                         args);
1495                         kfree(string);
1496                         switch (token) {
1497                         case Opt_local_lock_all:
1498                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1499                                                NFS_MOUNT_LOCAL_FCNTL);
1500                                 break;
1501                         case Opt_local_lock_flock:
1502                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1503                                 break;
1504                         case Opt_local_lock_posix:
1505                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1506                                 break;
1507                         case Opt_local_lock_none:
1508                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1509                                                 NFS_MOUNT_LOCAL_FCNTL);
1510                                 break;
1511                         default:
1512                                 dfprintk(MOUNT, "NFS:   invalid "
1513                                                 "local_lock argument\n");
1514                                 return 0;
1515                         };
1516                         break;
1517
1518                 /*
1519                  * Special options
1520                  */
1521                 case Opt_sloppy:
1522                         sloppy = 1;
1523                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1524                         break;
1525                 case Opt_userspace:
1526                 case Opt_deprecated:
1527                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1528                                         "'%s'\n", p);
1529                         break;
1530
1531                 default:
1532                         invalid_option = 1;
1533                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1534                                         "'%s'\n", p);
1535                 }
1536         }
1537
1538         if (!sloppy && invalid_option)
1539                 return 0;
1540
1541         if (mnt->minorversion && mnt->version != 4)
1542                 goto out_minorversion_mismatch;
1543
1544         /*
1545          * verify that any proto=/mountproto= options match the address
1546          * familiies in the addr=/mountaddr= options.
1547          */
1548         if (protofamily != AF_UNSPEC &&
1549             protofamily != mnt->nfs_server.address.ss_family)
1550                 goto out_proto_mismatch;
1551
1552         if (mountfamily != AF_UNSPEC) {
1553                 if (mnt->mount_server.addrlen) {
1554                         if (mountfamily != mnt->mount_server.address.ss_family)
1555                                 goto out_mountproto_mismatch;
1556                 } else {
1557                         if (mountfamily != mnt->nfs_server.address.ss_family)
1558                                 goto out_mountproto_mismatch;
1559                 }
1560         }
1561
1562         return 1;
1563
1564 out_mountproto_mismatch:
1565         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1566                          "option\n");
1567         return 0;
1568 out_proto_mismatch:
1569         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1570         return 0;
1571 out_invalid_address:
1572         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1573         return 0;
1574 out_invalid_value:
1575         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1576         return 0;
1577 out_minorversion_mismatch:
1578         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1579                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1580         return 0;
1581 out_nomem:
1582         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1583         return 0;
1584 out_security_failure:
1585         free_secdata(secdata);
1586         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1587         return 0;
1588 }
1589
1590 /*
1591  * Match the requested auth flavors with the list returned by
1592  * the server.  Returns zero and sets the mount's authentication
1593  * flavor on success; returns -EACCES if server does not support
1594  * the requested flavor.
1595  */
1596 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1597                              struct nfs_mount_request *request)
1598 {
1599         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1600
1601         /*
1602          * Certain releases of Linux's mountd return an empty
1603          * flavor list.  To prevent behavioral regression with
1604          * these servers (ie. rejecting mounts that used to
1605          * succeed), revert to pre-2.6.32 behavior (no checking)
1606          * if the returned flavor list is empty.
1607          */
1608         if (server_authlist_len == 0)
1609                 return 0;
1610
1611         /*
1612          * We avoid sophisticated negotiating here, as there are
1613          * plenty of cases where we can get it wrong, providing
1614          * either too little or too much security.
1615          *
1616          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1617          * flavor listed first.  However, some servers list
1618          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1619          * preferred default, in args->auth_flavors[0] if user
1620          * didn't specify sec= mount option.
1621          */
1622         for (i = 0; i < args->auth_flavor_len; i++)
1623                 for (j = 0; j < server_authlist_len; j++)
1624                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1625                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1626                                         request->auth_flavs[j]);
1627                                 args->auth_flavors[0] = request->auth_flavs[j];
1628                                 return 0;
1629                         }
1630
1631         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1632         nfs_umount(request);
1633         return -EACCES;
1634 }
1635
1636 /*
1637  * Use the remote server's MOUNT service to request the NFS file handle
1638  * corresponding to the provided path.
1639  */
1640 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1641                          struct nfs_fh *root_fh)
1642 {
1643         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1644         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1645         struct nfs_mount_request request = {
1646                 .sap            = (struct sockaddr *)
1647                                                 &args->mount_server.address,
1648                 .dirpath        = args->nfs_server.export_path,
1649                 .protocol       = args->mount_server.protocol,
1650                 .fh             = root_fh,
1651                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1652                 .auth_flav_len  = &server_authlist_len,
1653                 .auth_flavs     = server_authlist,
1654                 .net            = args->net,
1655         };
1656         int status;
1657
1658         if (args->mount_server.version == 0) {
1659                 switch (args->version) {
1660                         default:
1661                                 args->mount_server.version = NFS_MNT3_VERSION;
1662                                 break;
1663                         case 2:
1664                                 args->mount_server.version = NFS_MNT_VERSION;
1665                 }
1666         }
1667         request.version = args->mount_server.version;
1668
1669         if (args->mount_server.hostname)
1670                 request.hostname = args->mount_server.hostname;
1671         else
1672                 request.hostname = args->nfs_server.hostname;
1673
1674         /*
1675          * Construct the mount server's address.
1676          */
1677         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1678                 memcpy(request.sap, &args->nfs_server.address,
1679                        args->nfs_server.addrlen);
1680                 args->mount_server.addrlen = args->nfs_server.addrlen;
1681         }
1682         request.salen = args->mount_server.addrlen;
1683         nfs_set_port(request.sap, &args->mount_server.port, 0);
1684
1685         /*
1686          * Now ask the mount server to map our export path
1687          * to a file handle.
1688          */
1689         status = nfs_mount(&request);
1690         if (status != 0) {
1691                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1692                                 request.hostname, status);
1693                 return status;
1694         }
1695
1696         /*
1697          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1698          */
1699         if (args->mount_server.version != NFS_MNT3_VERSION)
1700                 return 0;
1701         return nfs_walk_authlist(args, &request);
1702 }
1703
1704 /*
1705  * Split "dev_name" into "hostname:export_path".
1706  *
1707  * The leftmost colon demarks the split between the server's hostname
1708  * and the export path.  If the hostname starts with a left square
1709  * bracket, then it may contain colons.
1710  *
1711  * Note: caller frees hostname and export path, even on error.
1712  */
1713 static int nfs_parse_devname(const char *dev_name,
1714                              char **hostname, size_t maxnamlen,
1715                              char **export_path, size_t maxpathlen)
1716 {
1717         size_t len;
1718         char *end;
1719
1720         /* Is the host name protected with square brakcets? */
1721         if (*dev_name == '[') {
1722                 end = strchr(++dev_name, ']');
1723                 if (end == NULL || end[1] != ':')
1724                         goto out_bad_devname;
1725
1726                 len = end - dev_name;
1727                 end++;
1728         } else {
1729                 char *comma;
1730
1731                 end = strchr(dev_name, ':');
1732                 if (end == NULL)
1733                         goto out_bad_devname;
1734                 len = end - dev_name;
1735
1736                 /* kill possible hostname list: not supported */
1737                 comma = strchr(dev_name, ',');
1738                 if (comma != NULL && comma < end)
1739                         *comma = 0;
1740         }
1741
1742         if (len > maxnamlen)
1743                 goto out_hostname;
1744
1745         /* N.B. caller will free nfs_server.hostname in all cases */
1746         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1747         if (*hostname == NULL)
1748                 goto out_nomem;
1749         len = strlen(++end);
1750         if (len > maxpathlen)
1751                 goto out_path;
1752         *export_path = kstrndup(end, len, GFP_KERNEL);
1753         if (!*export_path)
1754                 goto out_nomem;
1755
1756         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1757         return 0;
1758
1759 out_bad_devname:
1760         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1761         return -EINVAL;
1762
1763 out_nomem:
1764         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1765         return -ENOMEM;
1766
1767 out_hostname:
1768         dfprintk(MOUNT, "NFS: server hostname too long\n");
1769         return -ENAMETOOLONG;
1770
1771 out_path:
1772         dfprintk(MOUNT, "NFS: export pathname too long\n");
1773         return -ENAMETOOLONG;
1774 }
1775
1776 /*
1777  * Validate the NFS2/NFS3 mount data
1778  * - fills in the mount root filehandle
1779  *
1780  * For option strings, user space handles the following behaviors:
1781  *
1782  * + DNS: mapping server host name to IP address ("addr=" option)
1783  *
1784  * + failure mode: how to behave if a mount request can't be handled
1785  *   immediately ("fg/bg" option)
1786  *
1787  * + retry: how often to retry a mount request ("retry=" option)
1788  *
1789  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1790  *   mountproto=tcp after mountproto=udp, and so on
1791  */
1792 static int nfs_validate_mount_data(void *options,
1793                                    struct nfs_parsed_mount_data *args,
1794                                    struct nfs_fh *mntfh,
1795                                    const char *dev_name)
1796 {
1797         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1798         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1799
1800         if (data == NULL)
1801                 goto out_no_data;
1802
1803         switch (data->version) {
1804         case 1:
1805                 data->namlen = 0;
1806         case 2:
1807                 data->bsize = 0;
1808         case 3:
1809                 if (data->flags & NFS_MOUNT_VER3)
1810                         goto out_no_v3;
1811                 data->root.size = NFS2_FHSIZE;
1812                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1813         case 4:
1814                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1815                         goto out_no_sec;
1816         case 5:
1817                 memset(data->context, 0, sizeof(data->context));
1818         case 6:
1819                 if (data->flags & NFS_MOUNT_VER3) {
1820                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1821                                 goto out_invalid_fh;
1822                         mntfh->size = data->root.size;
1823                         args->version = 3;
1824                 } else {
1825                         mntfh->size = NFS2_FHSIZE;
1826                         args->version = 2;
1827                 }
1828
1829
1830                 memcpy(mntfh->data, data->root.data, mntfh->size);
1831                 if (mntfh->size < sizeof(mntfh->data))
1832                         memset(mntfh->data + mntfh->size, 0,
1833                                sizeof(mntfh->data) - mntfh->size);
1834
1835                 /*
1836                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1837                  * can deal with.
1838                  */
1839                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1840                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1841                 args->rsize             = data->rsize;
1842                 args->wsize             = data->wsize;
1843                 args->timeo             = data->timeo;
1844                 args->retrans           = data->retrans;
1845                 args->acregmin          = data->acregmin;
1846                 args->acregmax          = data->acregmax;
1847                 args->acdirmin          = data->acdirmin;
1848                 args->acdirmax          = data->acdirmax;
1849
1850                 memcpy(sap, &data->addr, sizeof(data->addr));
1851                 args->nfs_server.addrlen = sizeof(data->addr);
1852                 if (!nfs_verify_server_address(sap))
1853                         goto out_no_address;
1854
1855                 if (!(data->flags & NFS_MOUNT_TCP))
1856                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1857                 /* N.B. caller will free nfs_server.hostname in all cases */
1858                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1859                 args->namlen            = data->namlen;
1860                 args->bsize             = data->bsize;
1861
1862                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1863                         args->auth_flavors[0] = data->pseudoflavor;
1864                 if (!args->nfs_server.hostname)
1865                         goto out_nomem;
1866
1867                 if (!(data->flags & NFS_MOUNT_NONLM))
1868                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1869                                          NFS_MOUNT_LOCAL_FCNTL);
1870                 else
1871                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1872                                         NFS_MOUNT_LOCAL_FCNTL);
1873                 /*
1874                  * The legacy version 6 binary mount data from userspace has a
1875                  * field used only to transport selinux information into the
1876                  * the kernel.  To continue to support that functionality we
1877                  * have a touch of selinux knowledge here in the NFS code. The
1878                  * userspace code converted context=blah to just blah so we are
1879                  * converting back to the full string selinux understands.
1880                  */
1881                 if (data->context[0]){
1882 #ifdef CONFIG_SECURITY_SELINUX
1883                         int rc;
1884                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1885                         if (!opts_str)
1886                                 return -ENOMEM;
1887                         strcpy(opts_str, "context=");
1888                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1889                         strcat(opts_str, &data->context[0]);
1890                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1891                         kfree(opts_str);
1892                         if (rc)
1893                                 return rc;
1894 #else
1895                         return -EINVAL;
1896 #endif
1897                 }
1898
1899                 break;
1900         default: {
1901                 int status;
1902
1903                 if (nfs_parse_mount_options((char *)options, args) == 0)
1904                         return -EINVAL;
1905
1906                 if (!nfs_verify_server_address(sap))
1907                         goto out_no_address;
1908
1909                 if (args->version == 4)
1910 #ifdef CONFIG_NFS_V4
1911                         return nfs4_validate_text_mount_data(options,
1912                                                              args, dev_name);
1913 #else
1914                         goto out_v4_not_compiled;
1915 #endif
1916
1917                 nfs_set_port(sap, &args->nfs_server.port, 0);
1918
1919                 nfs_set_mount_transport_protocol(args);
1920
1921                 status = nfs_parse_devname(dev_name,
1922                                            &args->nfs_server.hostname,
1923                                            PAGE_SIZE,
1924                                            &args->nfs_server.export_path,
1925                                            NFS_MAXPATHLEN);
1926                 if (!status)
1927                         status = nfs_try_mount(args, mntfh);
1928
1929                 kfree(args->nfs_server.export_path);
1930                 args->nfs_server.export_path = NULL;
1931
1932                 if (status)
1933                         return status;
1934
1935                 break;
1936                 }
1937         }
1938
1939 #ifndef CONFIG_NFS_V3
1940         if (args->version == 3)
1941                 goto out_v3_not_compiled;
1942 #endif /* !CONFIG_NFS_V3 */
1943
1944         return 0;
1945
1946 out_no_data:
1947         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1948         return -EINVAL;
1949
1950 out_no_v3:
1951         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1952                  data->version);
1953         return -EINVAL;
1954
1955 out_no_sec:
1956         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1957         return -EINVAL;
1958
1959 #ifndef CONFIG_NFS_V3
1960 out_v3_not_compiled:
1961         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1962         return -EPROTONOSUPPORT;
1963 #endif /* !CONFIG_NFS_V3 */
1964
1965 #ifndef CONFIG_NFS_V4
1966 out_v4_not_compiled:
1967         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1968         return -EPROTONOSUPPORT;
1969 #endif /* !CONFIG_NFS_V4 */
1970
1971 out_nomem:
1972         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1973         return -ENOMEM;
1974
1975 out_no_address:
1976         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1977         return -EINVAL;
1978
1979 out_invalid_fh:
1980         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1981         return -EINVAL;
1982 }
1983
1984 static int
1985 nfs_compare_remount_data(struct nfs_server *nfss,
1986                          struct nfs_parsed_mount_data *data)
1987 {
1988         if (data->flags != nfss->flags ||
1989             data->rsize != nfss->rsize ||
1990             data->wsize != nfss->wsize ||
1991             data->retrans != nfss->client->cl_timeout->to_retries ||
1992             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1993             data->acregmin != nfss->acregmin / HZ ||
1994             data->acregmax != nfss->acregmax / HZ ||
1995             data->acdirmin != nfss->acdirmin / HZ ||
1996             data->acdirmax != nfss->acdirmax / HZ ||
1997             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1998             data->nfs_server.port != nfss->port ||
1999             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2000             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2001                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2002                 return -EINVAL;
2003
2004         return 0;
2005 }
2006
2007 static int
2008 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2009 {
2010         int error;
2011         struct nfs_server *nfss = sb->s_fs_info;
2012         struct nfs_parsed_mount_data *data;
2013         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2014         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2015         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2016
2017         /*
2018          * Userspace mount programs that send binary options generally send
2019          * them populated with default values. We have no way to know which
2020          * ones were explicitly specified. Fall back to legacy behavior and
2021          * just return success.
2022          */
2023         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2024             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2025                                            options->version <= 6))))
2026                 return 0;
2027
2028         data = kzalloc(sizeof(*data), GFP_KERNEL);
2029         if (data == NULL)
2030                 return -ENOMEM;
2031
2032         /* fill out struct with values from existing mount */
2033         data->flags = nfss->flags;
2034         data->rsize = nfss->rsize;
2035         data->wsize = nfss->wsize;
2036         data->retrans = nfss->client->cl_timeout->to_retries;
2037         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2038         data->acregmin = nfss->acregmin / HZ;
2039         data->acregmax = nfss->acregmax / HZ;
2040         data->acdirmin = nfss->acdirmin / HZ;
2041         data->acdirmax = nfss->acdirmax / HZ;
2042         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2043         data->nfs_server.port = nfss->port;
2044         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2045         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2046                 data->nfs_server.addrlen);
2047
2048         /* overwrite those values with any that were specified */
2049         error = nfs_parse_mount_options((char *)options, data);
2050         if (error < 0)
2051                 goto out;
2052
2053         /*
2054          * noac is a special case. It implies -o sync, but that's not
2055          * necessarily reflected in the mtab options. do_remount_sb
2056          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2057          * remount options, so we have to explicitly reset it.
2058          */
2059         if (data->flags & NFS_MOUNT_NOAC)
2060                 *flags |= MS_SYNCHRONOUS;
2061
2062         /* compare new mount options with old ones */
2063         error = nfs_compare_remount_data(nfss, data);
2064 out:
2065         kfree(data);
2066         return error;
2067 }
2068
2069 /*
2070  * Initialise the common bits of the superblock
2071  */
2072 static inline void nfs_initialise_sb(struct super_block *sb)
2073 {
2074         struct nfs_server *server = NFS_SB(sb);
2075
2076         sb->s_magic = NFS_SUPER_MAGIC;
2077
2078         /* We probably want something more informative here */
2079         snprintf(sb->s_id, sizeof(sb->s_id),
2080                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2081
2082         if (sb->s_blocksize == 0)
2083                 sb->s_blocksize = nfs_block_bits(server->wsize,
2084                                                  &sb->s_blocksize_bits);
2085
2086         sb->s_bdi = &server->backing_dev_info;
2087
2088         nfs_super_set_maxbytes(sb, server->maxfilesize);
2089 }
2090
2091 /*
2092  * Finish setting up an NFS2/3 superblock
2093  */
2094 static void nfs_fill_super(struct super_block *sb,
2095                            struct nfs_parsed_mount_data *data)
2096 {
2097         struct nfs_server *server = NFS_SB(sb);
2098
2099         sb->s_blocksize_bits = 0;
2100         sb->s_blocksize = 0;
2101         if (data->bsize)
2102                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2103
2104         if (server->nfs_client->rpc_ops->version == 3) {
2105                 /* The VFS shouldn't apply the umask to mode bits. We will do
2106                  * so ourselves when necessary.
2107                  */
2108                 sb->s_flags |= MS_POSIXACL;
2109                 sb->s_time_gran = 1;
2110         }
2111
2112         sb->s_op = &nfs_sops;
2113         nfs_initialise_sb(sb);
2114 }
2115
2116 /*
2117  * Finish setting up a cloned NFS2/3 superblock
2118  */
2119 static void nfs_clone_super(struct super_block *sb,
2120                             const struct super_block *old_sb)
2121 {
2122         struct nfs_server *server = NFS_SB(sb);
2123
2124         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2125         sb->s_blocksize = old_sb->s_blocksize;
2126         sb->s_maxbytes = old_sb->s_maxbytes;
2127
2128         if (server->nfs_client->rpc_ops->version == 3) {
2129                 /* The VFS shouldn't apply the umask to mode bits. We will do
2130                  * so ourselves when necessary.
2131                  */
2132                 sb->s_flags |= MS_POSIXACL;
2133                 sb->s_time_gran = 1;
2134         }
2135
2136         sb->s_op = old_sb->s_op;
2137         nfs_initialise_sb(sb);
2138 }
2139
2140 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2141 {
2142         const struct nfs_server *a = s->s_fs_info;
2143         const struct rpc_clnt *clnt_a = a->client;
2144         const struct rpc_clnt *clnt_b = b->client;
2145
2146         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2147                 goto Ebusy;
2148         if (a->nfs_client != b->nfs_client)
2149                 goto Ebusy;
2150         if (a->flags != b->flags)
2151                 goto Ebusy;
2152         if (a->wsize != b->wsize)
2153                 goto Ebusy;
2154         if (a->rsize != b->rsize)
2155                 goto Ebusy;
2156         if (a->acregmin != b->acregmin)
2157                 goto Ebusy;
2158         if (a->acregmax != b->acregmax)
2159                 goto Ebusy;
2160         if (a->acdirmin != b->acdirmin)
2161                 goto Ebusy;
2162         if (a->acdirmax != b->acdirmax)
2163                 goto Ebusy;
2164         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2165                 goto Ebusy;
2166         return 1;
2167 Ebusy:
2168         return 0;
2169 }
2170
2171 struct nfs_sb_mountdata {
2172         struct nfs_server *server;
2173         int mntflags;
2174 };
2175
2176 static int nfs_set_super(struct super_block *s, void *data)
2177 {
2178         struct nfs_sb_mountdata *sb_mntdata = data;
2179         struct nfs_server *server = sb_mntdata->server;
2180         int ret;
2181
2182         s->s_flags = sb_mntdata->mntflags;
2183         s->s_fs_info = server;
2184         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2185         ret = set_anon_super(s, server);
2186         if (ret == 0)
2187                 server->s_dev = s->s_dev;
2188         return ret;
2189 }
2190
2191 static int nfs_compare_super_address(struct nfs_server *server1,
2192                                      struct nfs_server *server2)
2193 {
2194         struct sockaddr *sap1, *sap2;
2195
2196         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2197         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2198
2199         if (sap1->sa_family != sap2->sa_family)
2200                 return 0;
2201
2202         switch (sap1->sa_family) {
2203         case AF_INET: {
2204                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2205                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2206                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2207                         return 0;
2208                 if (sin1->sin_port != sin2->sin_port)
2209                         return 0;
2210                 break;
2211         }
2212         case AF_INET6: {
2213                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2214                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2215                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2216                         return 0;
2217                 if (sin1->sin6_port != sin2->sin6_port)
2218                         return 0;
2219                 break;
2220         }
2221         default:
2222                 return 0;
2223         }
2224
2225         return 1;
2226 }
2227
2228 static int nfs_compare_super(struct super_block *sb, void *data)
2229 {
2230         struct nfs_sb_mountdata *sb_mntdata = data;
2231         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2232         int mntflags = sb_mntdata->mntflags;
2233
2234         if (!nfs_compare_super_address(old, server))
2235                 return 0;
2236         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2237         if (old->flags & NFS_MOUNT_UNSHARED)
2238                 return 0;
2239         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2240                 return 0;
2241         return nfs_compare_mount_options(sb, server, mntflags);
2242 }
2243
2244 static int nfs_bdi_register(struct nfs_server *server)
2245 {
2246         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2247 }
2248
2249 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2250         int flags, const char *dev_name, void *raw_data)
2251 {
2252         struct nfs_server *server = NULL;
2253         struct super_block *s;
2254         struct nfs_parsed_mount_data *data;
2255         struct nfs_fh *mntfh;
2256         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2257         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2258         struct nfs_sb_mountdata sb_mntdata = {
2259                 .mntflags = flags,
2260         };
2261         int error;
2262
2263         data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2264         mntfh = nfs_alloc_fhandle();
2265         if (data == NULL || mntfh == NULL)
2266                 goto out;
2267
2268         /* Validate the mount data */
2269         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2270         if (error < 0) {
2271                 mntroot = ERR_PTR(error);
2272                 goto out;
2273         }
2274
2275 #ifdef CONFIG_NFS_V4
2276         if (data->version == 4) {
2277                 mntroot = nfs4_try_mount(flags, dev_name, data);
2278                 goto out;
2279         }
2280 #endif  /* CONFIG_NFS_V4 */
2281
2282         /* Get a volume representation */
2283         server = nfs_create_server(data, mntfh);
2284         if (IS_ERR(server)) {
2285                 mntroot = ERR_CAST(server);
2286                 goto out;
2287         }
2288         sb_mntdata.server = server;
2289
2290         if (server->flags & NFS_MOUNT_UNSHARED)
2291                 compare_super = NULL;
2292
2293         /* -o noac implies -o sync */
2294         if (server->flags & NFS_MOUNT_NOAC)
2295                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2296
2297         /* Get a superblock - note that we may end up sharing one that already exists */
2298         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2299         if (IS_ERR(s)) {
2300                 mntroot = ERR_CAST(s);
2301                 goto out_err_nosb;
2302         }
2303
2304         if (s->s_fs_info != server) {
2305                 nfs_free_server(server);
2306                 server = NULL;
2307         } else {
2308                 error = nfs_bdi_register(server);
2309                 if (error) {
2310                         mntroot = ERR_PTR(error);
2311                         goto error_splat_bdi;
2312                 }
2313         }
2314
2315         if (!s->s_root) {
2316                 /* initial superblock/root creation */
2317                 nfs_fill_super(s, data);
2318                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2319         }
2320
2321         mntroot = nfs_get_root(s, mntfh, dev_name);
2322         if (IS_ERR(mntroot))
2323                 goto error_splat_super;
2324
2325         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2326         if (error)
2327                 goto error_splat_root;
2328
2329         s->s_flags |= MS_ACTIVE;
2330
2331 out:
2332         nfs_free_parsed_mount_data(data);
2333         nfs_free_fhandle(mntfh);
2334         return mntroot;
2335
2336 out_err_nosb:
2337         nfs_free_server(server);
2338         goto out;
2339
2340 error_splat_root:
2341         dput(mntroot);
2342         mntroot = ERR_PTR(error);
2343 error_splat_super:
2344         if (server && !s->s_root)
2345                 bdi_unregister(&server->backing_dev_info);
2346 error_splat_bdi:
2347         deactivate_locked_super(s);
2348         goto out;
2349 }
2350
2351 /*
2352  * Ensure that we unregister the bdi before kill_anon_super
2353  * releases the device name
2354  */
2355 static void nfs_put_super(struct super_block *s)
2356 {
2357         struct nfs_server *server = NFS_SB(s);
2358
2359         bdi_unregister(&server->backing_dev_info);
2360 }
2361
2362 /*
2363  * Destroy an NFS2/3 superblock
2364  */
2365 static void nfs_kill_super(struct super_block *s)
2366 {
2367         struct nfs_server *server = NFS_SB(s);
2368
2369         kill_anon_super(s);
2370         nfs_fscache_release_super_cookie(s);
2371         nfs_free_server(server);
2372 }
2373
2374 /*
2375  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2376  */
2377 static struct dentry *
2378 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2379                 const char *dev_name, void *raw_data)
2380 {
2381         struct nfs_clone_mount *data = raw_data;
2382         struct super_block *s;
2383         struct nfs_server *server;
2384         struct dentry *mntroot;
2385         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2386         struct nfs_sb_mountdata sb_mntdata = {
2387                 .mntflags = flags,
2388         };
2389         int error;
2390
2391         dprintk("--> nfs_xdev_mount()\n");
2392
2393         /* create a new volume representation */
2394         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2395         if (IS_ERR(server)) {
2396                 error = PTR_ERR(server);
2397                 goto out_err_noserver;
2398         }
2399         sb_mntdata.server = server;
2400
2401         if (server->flags & NFS_MOUNT_UNSHARED)
2402                 compare_super = NULL;
2403
2404         /* -o noac implies -o sync */
2405         if (server->flags & NFS_MOUNT_NOAC)
2406                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2407
2408         /* Get a superblock - note that we may end up sharing one that already exists */
2409         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2410         if (IS_ERR(s)) {
2411                 error = PTR_ERR(s);
2412                 goto out_err_nosb;
2413         }
2414
2415         if (s->s_fs_info != server) {
2416                 nfs_free_server(server);
2417                 server = NULL;
2418         } else {
2419                 error = nfs_bdi_register(server);
2420                 if (error)
2421                         goto error_splat_bdi;
2422         }
2423
2424         if (!s->s_root) {
2425                 /* initial superblock/root creation */
2426                 nfs_clone_super(s, data->sb);
2427                 nfs_fscache_get_super_cookie(s, NULL, data);
2428         }
2429
2430         mntroot = nfs_get_root(s, data->fh, dev_name);
2431         if (IS_ERR(mntroot)) {
2432                 error = PTR_ERR(mntroot);
2433                 goto error_splat_super;
2434         }
2435         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2436                 dput(mntroot);
2437                 error = -ESTALE;
2438                 goto error_splat_super;
2439         }
2440
2441         s->s_flags |= MS_ACTIVE;
2442
2443         /* clone any lsm security options from the parent to the new sb */
2444         security_sb_clone_mnt_opts(data->sb, s);
2445
2446         dprintk("<-- nfs_xdev_mount() = 0\n");
2447         return mntroot;
2448
2449 out_err_nosb:
2450         nfs_free_server(server);
2451 out_err_noserver:
2452         dprintk("<-- nfs_xdev_mount() = %d [error]\n", error);
2453         return ERR_PTR(error);
2454
2455 error_splat_super:
2456         if (server && !s->s_root)
2457                 bdi_unregister(&server->backing_dev_info);
2458 error_splat_bdi:
2459         deactivate_locked_super(s);
2460         dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error);
2461         return ERR_PTR(error);
2462 }
2463
2464 #ifdef CONFIG_NFS_V4
2465
2466 /*
2467  * Finish setting up a cloned NFS4 superblock
2468  */
2469 static void nfs4_clone_super(struct super_block *sb,
2470                             const struct super_block *old_sb)
2471 {
2472         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2473         sb->s_blocksize = old_sb->s_blocksize;
2474         sb->s_maxbytes = old_sb->s_maxbytes;
2475         sb->s_time_gran = 1;
2476         sb->s_op = old_sb->s_op;
2477         /*
2478          * The VFS shouldn't apply the umask to mode bits. We will do
2479          * so ourselves when necessary.
2480          */
2481         sb->s_flags  |= MS_POSIXACL;
2482         sb->s_xattr  = old_sb->s_xattr;
2483         nfs_initialise_sb(sb);
2484 }
2485
2486 /*
2487  * Set up an NFS4 superblock
2488  */
2489 static void nfs4_fill_super(struct super_block *sb)
2490 {
2491         sb->s_time_gran = 1;
2492         sb->s_op = &nfs4_sops;
2493         /*
2494          * The VFS shouldn't apply the umask to mode bits. We will do
2495          * so ourselves when necessary.
2496          */
2497         sb->s_flags  |= MS_POSIXACL;
2498         sb->s_xattr = nfs4_xattr_handlers;
2499         nfs_initialise_sb(sb);
2500 }
2501
2502 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2503 {
2504         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2505                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2506 }
2507
2508 static int nfs4_validate_text_mount_data(void *options,
2509                                          struct nfs_parsed_mount_data *args,
2510                                          const char *dev_name)
2511 {
2512         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2513
2514         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2515
2516         nfs_validate_transport_protocol(args);
2517
2518         nfs4_validate_mount_flags(args);
2519
2520         if (args->version != 4) {
2521                 dfprintk(MOUNT,
2522                          "NFS4: Illegal mount version\n");
2523                 return -EINVAL;
2524         }
2525
2526         if (args->auth_flavor_len > 1) {
2527                 dfprintk(MOUNT,
2528                          "NFS4: Too many RPC auth flavours specified\n");
2529                 return -EINVAL;
2530         }
2531
2532         if (args->client_address == NULL) {
2533                 dfprintk(MOUNT,
2534                          "NFS4: mount program didn't pass callback address\n");
2535                 return -EINVAL;
2536         }
2537
2538         return nfs_parse_devname(dev_name,
2539                                    &args->nfs_server.hostname,
2540                                    NFS4_MAXNAMLEN,
2541                                    &args->nfs_server.export_path,
2542                                    NFS4_MAXPATHLEN);
2543 }
2544
2545 /*
2546  * Validate NFSv4 mount options
2547  */
2548 static int nfs4_validate_mount_data(void *options,
2549                                     struct nfs_parsed_mount_data *args,
2550                                     const char *dev_name)
2551 {
2552         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2553         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2554         char *c;
2555
2556         if (data == NULL)
2557                 goto out_no_data;
2558
2559         switch (data->version) {
2560         case 1:
2561                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2562                         goto out_no_address;
2563                 if (data->host_addrlen == 0)
2564                         goto out_no_address;
2565                 args->nfs_server.addrlen = data->host_addrlen;
2566                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2567                         return -EFAULT;
2568                 if (!nfs_verify_server_address(sap))
2569                         goto out_no_address;
2570
2571                 if (data->auth_flavourlen) {
2572                         if (data->auth_flavourlen > 1)
2573                                 goto out_inval_auth;
2574                         if (copy_from_user(&args->auth_flavors[0],
2575                                            data->auth_flavours,
2576                                            sizeof(args->auth_flavors[0])))
2577                                 return -EFAULT;
2578                 }
2579
2580                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2581                 if (IS_ERR(c))
2582                         return PTR_ERR(c);
2583                 args->nfs_server.hostname = c;
2584
2585                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2586                 if (IS_ERR(c))
2587                         return PTR_ERR(c);
2588                 args->nfs_server.export_path = c;
2589                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2590
2591                 c = strndup_user(data->client_addr.data, 16);
2592                 if (IS_ERR(c))
2593                         return PTR_ERR(c);
2594                 args->client_address = c;
2595
2596                 /*
2597                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2598                  * can deal with.
2599                  */
2600
2601                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2602                 args->rsize     = data->rsize;
2603                 args->wsize     = data->wsize;
2604                 args->timeo     = data->timeo;
2605                 args->retrans   = data->retrans;
2606                 args->acregmin  = data->acregmin;
2607                 args->acregmax  = data->acregmax;
2608                 args->acdirmin  = data->acdirmin;
2609                 args->acdirmax  = data->acdirmax;
2610                 args->nfs_server.protocol = data->proto;
2611                 nfs_validate_transport_protocol(args);
2612
2613                 break;
2614         default:
2615                 if (nfs_parse_mount_options((char *)options, args) == 0)
2616                         return -EINVAL;
2617
2618                 if (!nfs_verify_server_address(sap))
2619                         return -EINVAL;
2620
2621                 return nfs4_validate_text_mount_data(options, args, dev_name);
2622         }
2623
2624         return 0;
2625
2626 out_no_data:
2627         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2628         return -EINVAL;
2629
2630 out_inval_auth:
2631         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2632                  data->auth_flavourlen);
2633         return -EINVAL;
2634
2635 out_no_address:
2636         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2637         return -EINVAL;
2638 }
2639
2640 /*
2641  * Get the superblock for the NFS4 root partition
2642  */
2643 static struct dentry *
2644 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2645                   const char *dev_name, void *raw_data)
2646 {
2647         struct nfs_parsed_mount_data *data = raw_data;
2648         struct super_block *s;
2649         struct nfs_server *server;
2650         struct nfs_fh *mntfh;
2651         struct dentry *mntroot;
2652         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2653         struct nfs_sb_mountdata sb_mntdata = {
2654                 .mntflags = flags,
2655         };
2656         int error = -ENOMEM;
2657
2658         mntfh = nfs_alloc_fhandle();
2659         if (data == NULL || mntfh == NULL)
2660                 goto out;
2661
2662         /* Get a volume representation */
2663         server = nfs4_create_server(data, mntfh);
2664         if (IS_ERR(server)) {
2665                 error = PTR_ERR(server);
2666                 goto out;
2667         }
2668         sb_mntdata.server = server;
2669
2670         if (server->flags & NFS4_MOUNT_UNSHARED)
2671                 compare_super = NULL;
2672
2673         /* -o noac implies -o sync */
2674         if (server->flags & NFS_MOUNT_NOAC)
2675                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2676
2677         /* Get a superblock - note that we may end up sharing one that already exists */
2678         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2679         if (IS_ERR(s)) {
2680                 error = PTR_ERR(s);
2681                 goto out_free;
2682         }
2683
2684         if (s->s_fs_info != server) {
2685                 nfs_free_server(server);
2686                 server = NULL;
2687         } else {
2688                 error = nfs_bdi_register(server);
2689                 if (error)
2690                         goto error_splat_bdi;
2691         }
2692
2693         if (!s->s_root) {
2694                 /* initial superblock/root creation */
2695                 nfs4_fill_super(s);
2696                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2697         }
2698
2699         mntroot = nfs4_get_root(s, mntfh, dev_name);
2700         if (IS_ERR(mntroot)) {
2701                 error = PTR_ERR(mntroot);
2702                 goto error_splat_super;
2703         }
2704
2705         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2706         if (error)
2707                 goto error_splat_root;
2708
2709         s->s_flags |= MS_ACTIVE;
2710
2711         nfs_free_fhandle(mntfh);
2712         return mntroot;
2713
2714 out:
2715         nfs_free_fhandle(mntfh);
2716         return ERR_PTR(error);
2717
2718 out_free:
2719         nfs_free_server(server);
2720         goto out;
2721
2722 error_splat_root:
2723         dput(mntroot);
2724 error_splat_super:
2725         if (server && !s->s_root)
2726                 bdi_unregister(&server->backing_dev_info);
2727 error_splat_bdi:
2728         deactivate_locked_super(s);
2729         goto out;
2730 }
2731
2732 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2733                 int flags, void *data, const char *hostname)
2734 {
2735         struct vfsmount *root_mnt;
2736         char *root_devname;
2737         size_t len;
2738
2739         len = strlen(hostname) + 3;
2740         root_devname = kmalloc(len, GFP_KERNEL);
2741         if (root_devname == NULL)
2742                 return ERR_PTR(-ENOMEM);
2743         snprintf(root_devname, len, "%s:/", hostname);
2744         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2745         kfree(root_devname);
2746         return root_mnt;
2747 }
2748
2749 struct nfs_referral_count {
2750         struct list_head list;
2751         const struct task_struct *task;
2752         unsigned int referral_count;
2753 };
2754
2755 static LIST_HEAD(nfs_referral_count_list);
2756 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2757
2758 static struct nfs_referral_count *nfs_find_referral_count(void)
2759 {
2760         struct nfs_referral_count *p;
2761
2762         list_for_each_entry(p, &nfs_referral_count_list, list) {
2763                 if (p->task == current)
2764                         return p;
2765         }
2766         return NULL;
2767 }
2768
2769 #define NFS_MAX_NESTED_REFERRALS 2
2770
2771 static int nfs_referral_loop_protect(void)
2772 {
2773         struct nfs_referral_count *p, *new;
2774         int ret = -ENOMEM;
2775
2776         new = kmalloc(sizeof(*new), GFP_KERNEL);
2777         if (!new)
2778                 goto out;
2779         new->task = current;
2780         new->referral_count = 1;
2781
2782         ret = 0;
2783         spin_lock(&nfs_referral_count_list_lock);
2784         p = nfs_find_referral_count();
2785         if (p != NULL) {
2786                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2787                         ret = -ELOOP;
2788                 else
2789                         p->referral_count++;
2790         } else {
2791                 list_add(&new->list, &nfs_referral_count_list);
2792                 new = NULL;
2793         }
2794         spin_unlock(&nfs_referral_count_list_lock);
2795         kfree(new);
2796 out:
2797         return ret;
2798 }
2799
2800 static void nfs_referral_loop_unprotect(void)
2801 {
2802         struct nfs_referral_count *p;
2803
2804         spin_lock(&nfs_referral_count_list_lock);
2805         p = nfs_find_referral_count();
2806         p->referral_count--;
2807         if (p->referral_count == 0)
2808                 list_del(&p->list);
2809         else
2810                 p = NULL;
2811         spin_unlock(&nfs_referral_count_list_lock);
2812         kfree(p);
2813 }
2814
2815 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2816                 const char *export_path)
2817 {
2818         struct dentry *dentry;
2819         int err;
2820
2821         if (IS_ERR(root_mnt))
2822                 return ERR_CAST(root_mnt);
2823
2824         err = nfs_referral_loop_protect();
2825         if (err) {
2826                 mntput(root_mnt);
2827                 return ERR_PTR(err);
2828         }
2829
2830         dentry = mount_subtree(root_mnt, export_path);
2831         nfs_referral_loop_unprotect();
2832
2833         return dentry;
2834 }
2835
2836 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2837                          struct nfs_parsed_mount_data *data)
2838 {
2839         char *export_path;
2840         struct vfsmount *root_mnt;
2841         struct dentry *res;
2842
2843         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2844
2845         export_path = data->nfs_server.export_path;
2846         data->nfs_server.export_path = "/";
2847         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2848                         data->nfs_server.hostname);
2849         data->nfs_server.export_path = export_path;
2850
2851         res = nfs_follow_remote_path(root_mnt, export_path);
2852
2853         dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2854                         IS_ERR(res) ? PTR_ERR(res) : 0,
2855                         IS_ERR(res) ? " [error]" : "");
2856         return res;
2857 }
2858
2859 /*
2860  * Get the superblock for an NFS4 mountpoint
2861  */
2862 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2863         int flags, const char *dev_name, void *raw_data)
2864 {
2865         struct nfs_parsed_mount_data *data;
2866         int error = -ENOMEM;
2867         struct dentry *res = ERR_PTR(-ENOMEM);
2868
2869         data = nfs_alloc_parsed_mount_data(4);
2870         if (data == NULL)
2871                 goto out;
2872
2873         /* Validate the mount data */
2874         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2875         if (error < 0) {
2876                 res = ERR_PTR(error);
2877                 goto out;
2878         }
2879
2880         res = nfs4_try_mount(flags, dev_name, data);
2881         if (IS_ERR(res))
2882                 error = PTR_ERR(res);
2883
2884 out:
2885         nfs_free_parsed_mount_data(data);
2886         dprintk("<-- nfs4_mount() = %d%s\n", error,
2887                         error != 0 ? " [error]" : "");
2888         return res;
2889 }
2890
2891 static void nfs4_kill_super(struct super_block *sb)
2892 {
2893         struct nfs_server *server = NFS_SB(sb);
2894
2895         dprintk("--> %s\n", __func__);
2896         nfs_super_return_all_delegations(sb);
2897         kill_anon_super(sb);
2898         nfs_fscache_release_super_cookie(sb);
2899         nfs_free_server(server);
2900         dprintk("<-- %s\n", __func__);
2901 }
2902
2903 /*
2904  * Clone an NFS4 server record on xdev traversal (FSID-change)
2905  */
2906 static struct dentry *
2907 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2908                  const char *dev_name, void *raw_data)
2909 {
2910         struct nfs_clone_mount *data = raw_data;
2911         struct super_block *s;
2912         struct nfs_server *server;
2913         struct dentry *mntroot;
2914         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2915         struct nfs_sb_mountdata sb_mntdata = {
2916                 .mntflags = flags,
2917         };
2918         int error;
2919
2920         dprintk("--> nfs4_xdev_mount()\n");
2921
2922         /* create a new volume representation */
2923         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2924         if (IS_ERR(server)) {
2925                 error = PTR_ERR(server);
2926                 goto out_err_noserver;
2927         }
2928         sb_mntdata.server = server;
2929
2930         if (server->flags & NFS4_MOUNT_UNSHARED)
2931                 compare_super = NULL;
2932
2933         /* -o noac implies -o sync */
2934         if (server->flags & NFS_MOUNT_NOAC)
2935                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2936
2937         /* Get a superblock - note that we may end up sharing one that already exists */
2938         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2939         if (IS_ERR(s)) {
2940                 error = PTR_ERR(s);
2941                 goto out_err_nosb;
2942         }
2943
2944         if (s->s_fs_info != server) {
2945                 nfs_free_server(server);
2946                 server = NULL;
2947         } else {
2948                 error = nfs_bdi_register(server);
2949                 if (error)
2950                         goto error_splat_bdi;
2951         }
2952
2953         if (!s->s_root) {
2954                 /* initial superblock/root creation */
2955                 nfs4_clone_super(s, data->sb);
2956                 nfs_fscache_get_super_cookie(s, NULL, data);
2957         }
2958
2959         mntroot = nfs4_get_root(s, data->fh, dev_name);
2960         if (IS_ERR(mntroot)) {
2961                 error = PTR_ERR(mntroot);
2962                 goto error_splat_super;
2963         }
2964         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2965                 dput(mntroot);
2966                 error = -ESTALE;
2967                 goto error_splat_super;
2968         }
2969
2970         s->s_flags |= MS_ACTIVE;
2971
2972         security_sb_clone_mnt_opts(data->sb, s);
2973
2974         dprintk("<-- nfs4_xdev_mount() = 0\n");
2975         return mntroot;
2976
2977 out_err_nosb:
2978         nfs_free_server(server);
2979 out_err_noserver:
2980         dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error);
2981         return ERR_PTR(error);
2982
2983 error_splat_super:
2984         if (server && !s->s_root)
2985                 bdi_unregister(&server->backing_dev_info);
2986 error_splat_bdi:
2987         deactivate_locked_super(s);
2988         dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error);
2989         return ERR_PTR(error);
2990 }
2991
2992 static struct dentry *
2993 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2994                            const char *dev_name, void *raw_data)
2995 {
2996         struct nfs_clone_mount *data = raw_data;
2997         struct super_block *s;
2998         struct nfs_server *server;
2999         struct dentry *mntroot;
3000         struct nfs_fh *mntfh;
3001         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
3002         struct nfs_sb_mountdata sb_mntdata = {
3003                 .mntflags = flags,
3004         };
3005         int error = -ENOMEM;
3006
3007         dprintk("--> nfs4_referral_get_sb()\n");
3008
3009         mntfh = nfs_alloc_fhandle();
3010         if (mntfh == NULL)
3011                 goto out_err_nofh;
3012
3013         /* create a new volume representation */
3014         server = nfs4_create_referral_server(data, mntfh);
3015         if (IS_ERR(server)) {
3016                 error = PTR_ERR(server);
3017                 goto out_err_noserver;
3018         }
3019         sb_mntdata.server = server;
3020
3021         if (server->flags & NFS4_MOUNT_UNSHARED)
3022                 compare_super = NULL;
3023
3024         /* -o noac implies -o sync */
3025         if (server->flags & NFS_MOUNT_NOAC)
3026                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
3027
3028         /* Get a superblock - note that we may end up sharing one that already exists */
3029         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3030         if (IS_ERR(s)) {
3031                 error = PTR_ERR(s);
3032                 goto out_err_nosb;
3033         }
3034
3035         if (s->s_fs_info != server) {
3036                 nfs_free_server(server);
3037                 server = NULL;
3038         } else {
3039                 error = nfs_bdi_register(server);
3040                 if (error)
3041                         goto error_splat_bdi;
3042         }
3043
3044         if (!s->s_root) {
3045                 /* initial superblock/root creation */
3046                 nfs4_fill_super(s);
3047                 nfs_fscache_get_super_cookie(s, NULL, data);
3048         }
3049
3050         mntroot = nfs4_get_root(s, mntfh, dev_name);
3051         if (IS_ERR(mntroot)) {
3052                 error = PTR_ERR(mntroot);
3053                 goto error_splat_super;
3054         }
3055         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3056                 dput(mntroot);
3057                 error = -ESTALE;
3058                 goto error_splat_super;
3059         }
3060
3061         s->s_flags |= MS_ACTIVE;
3062
3063         security_sb_clone_mnt_opts(data->sb, s);
3064
3065         nfs_free_fhandle(mntfh);
3066         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3067         return mntroot;
3068
3069 out_err_nosb:
3070         nfs_free_server(server);
3071 out_err_noserver:
3072         nfs_free_fhandle(mntfh);
3073 out_err_nofh:
3074         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3075         return ERR_PTR(error);
3076
3077 error_splat_super:
3078         if (server && !s->s_root)
3079                 bdi_unregister(&server->backing_dev_info);
3080 error_splat_bdi:
3081         deactivate_locked_super(s);
3082         nfs_free_fhandle(mntfh);
3083         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3084         return ERR_PTR(error);
3085 }
3086
3087 /*
3088  * Create an NFS4 server record on referral traversal
3089  */
3090 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3091                 int flags, const char *dev_name, void *raw_data)
3092 {
3093         struct nfs_clone_mount *data = raw_data;
3094         char *export_path;
3095         struct vfsmount *root_mnt;
3096         struct dentry *res;
3097
3098         dprintk("--> nfs4_referral_mount()\n");
3099
3100         export_path = data->mnt_path;
3101         data->mnt_path = "/";
3102
3103         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3104                         flags, data, data->hostname);
3105         data->mnt_path = export_path;
3106
3107         res = nfs_follow_remote_path(root_mnt, export_path);
3108         dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3109                         IS_ERR(res) ? PTR_ERR(res) : 0,
3110                         IS_ERR(res) ? " [error]" : "");
3111         return res;
3112 }
3113
3114 #endif /* CONFIG_NFS_V4 */