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/smp_lock.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/nfs_idmap.h>
  46 #include <linux/vfs.h>
  47 #include <linux/inet.h>
  48 #include <linux/in6.h>
  49 #include <net/ipv6.h>
  50 #include <linux/netdevice.h>
  51 #include <linux/nfs_xdr.h>
  52 #include <linux/magic.h>
  53 #include <linux/parser.h>
  54
  55 #include <asm/system.h>
  56 #include <asm/uaccess.h>
  57
  58 #include "nfs4_fs.h"
  59 #include "callback.h"
  60 #include "delegation.h"
  61 #include "iostat.h"
  62 #include "internal.h"
  63 #include "fscache.h"
  64
  65 #define NFSDBG_FACILITY         NFSDBG_VFS
  66
  67 enum {
  68         /* Mount options that take no arguments */
  69         Opt_soft, Opt_hard,
  70         Opt_posix, Opt_noposix,
  71         Opt_cto, Opt_nocto,
  72         Opt_ac, Opt_noac,
  73         Opt_lock, Opt_nolock,
  74         Opt_v2, Opt_v3,
  75         Opt_udp, Opt_tcp, Opt_rdma,
  76         Opt_acl, Opt_noacl,
  77         Opt_rdirplus, Opt_nordirplus,
  78         Opt_sharecache, Opt_nosharecache,
  79         Opt_resvport, Opt_noresvport,
  80         Opt_fscache, Opt_nofscache,
  81
  82         /* Mount options that take integer arguments */
  83         Opt_port,
  84         Opt_rsize, Opt_wsize, Opt_bsize,
  85         Opt_timeo, Opt_retrans,
  86         Opt_acregmin, Opt_acregmax,
  87         Opt_acdirmin, Opt_acdirmax,
  88         Opt_actimeo,
  89         Opt_namelen,
  90         Opt_mountport,
  91         Opt_mountvers,
  92         Opt_nfsvers,
  93
  94         /* Mount options that take string arguments */
  95         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
  96         Opt_addr, Opt_mountaddr, Opt_clientaddr,
  97         Opt_lookupcache,
  98         Opt_fscache_uniq,
  99
 100         /* Special mount options */
 101         Opt_userspace, Opt_deprecated, Opt_sloppy,
 102
 103         Opt_err
 104 };
 105
 106 static const match_table_t nfs_mount_option_tokens = {
 107         { Opt_userspace, "bg" },
 108         { Opt_userspace, "fg" },
 109         { Opt_userspace, "retry=%s" },
 110
 111         { Opt_sloppy, "sloppy" },
 112
 113         { Opt_soft, "soft" },
 114         { Opt_hard, "hard" },
 115         { Opt_deprecated, "intr" },
 116         { Opt_deprecated, "nointr" },
 117         { Opt_posix, "posix" },
 118         { Opt_noposix, "noposix" },
 119         { Opt_cto, "cto" },
 120         { Opt_nocto, "nocto" },
 121         { Opt_ac, "ac" },
 122         { Opt_noac, "noac" },
 123         { Opt_lock, "lock" },
 124         { Opt_nolock, "nolock" },
 125         { Opt_v2, "v2" },
 126         { Opt_v3, "v3" },
 127         { Opt_udp, "udp" },
 128         { Opt_tcp, "tcp" },
 129         { Opt_rdma, "rdma" },
 130         { Opt_acl, "acl" },
 131         { Opt_noacl, "noacl" },
 132         { Opt_rdirplus, "rdirplus" },
 133         { Opt_nordirplus, "nordirplus" },
 134         { Opt_sharecache, "sharecache" },
 135         { Opt_nosharecache, "nosharecache" },
 136         { Opt_resvport, "resvport" },
 137         { Opt_noresvport, "noresvport" },
 138         { Opt_fscache, "fsc" },
 139         { Opt_fscache_uniq, "fsc=%s" },
 140         { Opt_nofscache, "nofsc" },
 141
 142         { Opt_port, "port=%u" },
 143         { Opt_rsize, "rsize=%u" },
 144         { Opt_wsize, "wsize=%u" },
 145         { Opt_bsize, "bsize=%u" },
 146         { Opt_timeo, "timeo=%u" },
 147         { Opt_retrans, "retrans=%u" },
 148         { Opt_acregmin, "acregmin=%u" },
 149         { Opt_acregmax, "acregmax=%u" },
 150         { Opt_acdirmin, "acdirmin=%u" },
 151         { Opt_acdirmax, "acdirmax=%u" },
 152         { Opt_actimeo, "actimeo=%u" },
 153         { Opt_namelen, "namlen=%u" },
 154         { Opt_mountport, "mountport=%u" },
 155         { Opt_mountvers, "mountvers=%u" },
 156         { Opt_nfsvers, "nfsvers=%u" },
 157         { Opt_nfsvers, "vers=%u" },
 158
 159         { Opt_sec, "sec=%s" },
 160         { Opt_proto, "proto=%s" },
 161         { Opt_mountproto, "mountproto=%s" },
 162         { Opt_addr, "addr=%s" },
 163         { Opt_clientaddr, "clientaddr=%s" },
 164         { Opt_mounthost, "mounthost=%s" },
 165         { Opt_mountaddr, "mountaddr=%s" },
 166
 167         { Opt_lookupcache, "lookupcache=%s" },
 168
 169         { Opt_err, NULL }
 170 };
 171
 172 enum {
 173         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 174
 175         Opt_xprt_err
 176 };
 177
 178 static const match_table_t nfs_xprt_protocol_tokens = {
 179         { Opt_xprt_udp, "udp" },
 180         { Opt_xprt_tcp, "tcp" },
 181         { Opt_xprt_rdma, "rdma" },
 182
 183         { Opt_xprt_err, NULL }
 184 };
 185
 186 enum {
 187         Opt_sec_none, Opt_sec_sys,
 188         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 189         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 190         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 191
 192         Opt_sec_err
 193 };
 194
 195 static const match_table_t nfs_secflavor_tokens = {
 196         { Opt_sec_none, "none" },
 197         { Opt_sec_none, "null" },
 198         { Opt_sec_sys, "sys" },
 199
 200         { Opt_sec_krb5, "krb5" },
 201         { Opt_sec_krb5i, "krb5i" },
 202         { Opt_sec_krb5p, "krb5p" },
 203
 204         { Opt_sec_lkey, "lkey" },
 205         { Opt_sec_lkeyi, "lkeyi" },
 206         { Opt_sec_lkeyp, "lkeyp" },
 207
 208         { Opt_sec_spkm, "spkm3" },
 209         { Opt_sec_spkmi, "spkm3i" },
 210         { Opt_sec_spkmp, "spkm3p" },
 211
 212         { Opt_sec_err, NULL }
 213 };
 214
 215 enum {
 216         Opt_lookupcache_all, Opt_lookupcache_positive,
 217         Opt_lookupcache_none,
 218
 219         Opt_lookupcache_err
 220 };
 221
 222 static match_table_t nfs_lookupcache_tokens = {
 223         { Opt_lookupcache_all, "all" },
 224         { Opt_lookupcache_positive, "pos" },
 225         { Opt_lookupcache_positive, "positive" },
 226         { Opt_lookupcache_none, "none" },
 227
 228         { Opt_lookupcache_err, NULL }
 229 };
 230
 231
 232 static void nfs_umount_begin(struct super_block *);
 233 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 234 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 235 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 236 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 237 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 238                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 239 static void nfs_kill_super(struct super_block *);
 240 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 241
 242 static struct file_system_type nfs_fs_type = {
 243         .owner          = THIS_MODULE,
 244         .name           = "nfs",
 245         .get_sb         = nfs_get_sb,
 246         .kill_sb        = nfs_kill_super,
 247         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 248 };
 249
 250 struct file_system_type nfs_xdev_fs_type = {
 251         .owner          = THIS_MODULE,
 252         .name           = "nfs",
 253         .get_sb         = nfs_xdev_get_sb,
 254         .kill_sb        = nfs_kill_super,
 255         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 256 };
 257
 258 static const struct super_operations nfs_sops = {
 259         .alloc_inode    = nfs_alloc_inode,
 260         .destroy_inode  = nfs_destroy_inode,
 261         .write_inode    = nfs_write_inode,
 262         .statfs         = nfs_statfs,
 263         .clear_inode    = nfs_clear_inode,
 264         .umount_begin   = nfs_umount_begin,
 265         .show_options   = nfs_show_options,
 266         .show_stats     = nfs_show_stats,
 267         .remount_fs     = nfs_remount,
 268 };
 269
 270 #ifdef CONFIG_NFS_V4
 271 static int nfs4_get_sb(struct file_system_type *fs_type,
 272         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 273 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 274         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 275 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 276         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 277 static void nfs4_kill_super(struct super_block *sb);
 278
 279 static struct file_system_type nfs4_fs_type = {
 280         .owner          = THIS_MODULE,
 281         .name           = "nfs4",
 282         .get_sb         = nfs4_get_sb,
 283         .kill_sb        = nfs4_kill_super,
 284         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 285 };
 286
 287 struct file_system_type nfs4_xdev_fs_type = {
 288         .owner          = THIS_MODULE,
 289         .name           = "nfs4",
 290         .get_sb         = nfs4_xdev_get_sb,
 291         .kill_sb        = nfs4_kill_super,
 292         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 293 };
 294
 295 struct file_system_type nfs4_referral_fs_type = {
 296         .owner          = THIS_MODULE,
 297         .name           = "nfs4",
 298         .get_sb         = nfs4_referral_get_sb,
 299         .kill_sb        = nfs4_kill_super,
 300         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 301 };
 302
 303 static const struct super_operations nfs4_sops = {
 304         .alloc_inode    = nfs_alloc_inode,
 305         .destroy_inode  = nfs_destroy_inode,
 306         .write_inode    = nfs_write_inode,
 307         .statfs         = nfs_statfs,
 308         .clear_inode    = nfs4_clear_inode,
 309         .umount_begin   = nfs_umount_begin,
 310         .show_options   = nfs_show_options,
 311         .show_stats     = nfs_show_stats,
 312         .remount_fs     = nfs_remount,
 313 };
 314 #endif
 315
 316 static struct shrinker acl_shrinker = {
 317         .shrink         = nfs_access_cache_shrinker,
 318         .seeks          = DEFAULT_SEEKS,
 319 };
 320
 321 /*
 322  * Register the NFS filesystems
 323  */
 324 int __init register_nfs_fs(void)
 325 {
 326         int ret;
 327
 328         ret = register_filesystem(&nfs_fs_type);
 329         if (ret < 0)
 330                 goto error_0;
 331
 332         ret = nfs_register_sysctl();
 333         if (ret < 0)
 334                 goto error_1;
 335 #ifdef CONFIG_NFS_V4
 336         ret = register_filesystem(&nfs4_fs_type);
 337         if (ret < 0)
 338                 goto error_2;
 339 #endif
 340         register_shrinker(&acl_shrinker);
 341         return 0;
 342
 343 #ifdef CONFIG_NFS_V4
 344 error_2:
 345         nfs_unregister_sysctl();
 346 #endif
 347 error_1:
 348         unregister_filesystem(&nfs_fs_type);
 349 error_0:
 350         return ret;
 351 }
 352
 353 /*
 354  * Unregister the NFS filesystems
 355  */
 356 void __exit unregister_nfs_fs(void)
 357 {
 358         unregister_shrinker(&acl_shrinker);
 359 #ifdef CONFIG_NFS_V4
 360         unregister_filesystem(&nfs4_fs_type);
 361 #endif
 362         nfs_unregister_sysctl();
 363         unregister_filesystem(&nfs_fs_type);
 364 }
 365
 366 void nfs_sb_active(struct super_block *sb)
 367 {
 368         struct nfs_server *server = NFS_SB(sb);
 369
 370         if (atomic_inc_return(&server->active) == 1)
 371                 atomic_inc(&sb->s_active);
 372 }
 373
 374 void nfs_sb_deactive(struct super_block *sb)
 375 {
 376         struct nfs_server *server = NFS_SB(sb);
 377
 378         if (atomic_dec_and_test(&server->active))
 379                 deactivate_super(sb);
 380 }
 381
 382 /*
 383  * Deliver file system statistics to userspace
 384  */
 385 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 386 {
 387         struct nfs_server *server = NFS_SB(dentry->d_sb);
 388         unsigned char blockbits;
 389         unsigned long blockres;
 390         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 391         struct nfs_fattr fattr;
 392         struct nfs_fsstat res = {
 393                         .fattr = &fattr,
 394         };
 395         int error;
 396
 397         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 398         if (error < 0)
 399                 goto out_err;
 400         buf->f_type = NFS_SUPER_MAGIC;
 401
 402         /*
 403          * Current versions of glibc do not correctly handle the
 404          * case where f_frsize != f_bsize.  Eventually we want to
 405          * report the value of wtmult in this field.
 406          */
 407         buf->f_frsize = dentry->d_sb->s_blocksize;
 408
 409         /*
 410          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 411          * are reported in units of f_frsize.  Linux hasn't had
 412          * an f_frsize field in its statfs struct until recently,
 413          * thus historically Linux's sys_statfs reports these
 414          * fields in units of f_bsize.
 415          */
 416         buf->f_bsize = dentry->d_sb->s_blocksize;
 417         blockbits = dentry->d_sb->s_blocksize_bits;
 418         blockres = (1 << blockbits) - 1;
 419         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 420         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 421         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 422
 423         buf->f_files = res.tfiles;
 424         buf->f_ffree = res.afiles;
 425
 426         buf->f_namelen = server->namelen;
 427
 428         return 0;
 429
 430  out_err:
 431         dprintk("%s: statfs error = %d\n", __func__, -error);
 432         return error;
 433 }
 434
 435 /*
 436  * Map the security flavour number to a name
 437  */
 438 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 439 {
 440         static const struct {
 441                 rpc_authflavor_t flavour;
 442                 const char *str;
 443         } sec_flavours[] = {
 444                 { RPC_AUTH_NULL, "null" },
 445                 { RPC_AUTH_UNIX, "sys" },
 446                 { RPC_AUTH_GSS_KRB5, "krb5" },
 447                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 448                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 449                 { RPC_AUTH_GSS_LKEY, "lkey" },
 450                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 451                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 452                 { RPC_AUTH_GSS_SPKM, "spkm" },
 453                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 454                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 455                 { UINT_MAX, "unknown" }
 456         };
 457         int i;
 458
 459         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 460                 if (sec_flavours[i].flavour == flavour)
 461                         break;
 462         }
 463         return sec_flavours[i].str;
 464 }
 465
 466 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 467                                     int showdefaults)
 468 {
 469         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 470
 471         switch (sap->sa_family) {
 472         case AF_INET: {
 473                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 474                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 475                 break;
 476         }
 477         case AF_INET6: {
 478                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 479                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 480                 break;
 481         }
 482         default:
 483                 if (showdefaults)
 484                         seq_printf(m, ",mountaddr=unspecified");
 485         }
 486
 487         if (nfss->mountd_version || showdefaults)
 488                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 489         if (nfss->mountd_port || showdefaults)
 490                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 491
 492         switch (nfss->mountd_protocol) {
 493         case IPPROTO_UDP:
 494                 seq_printf(m, ",mountproto=udp");
 495                 break;
 496         case IPPROTO_TCP:
 497                 seq_printf(m, ",mountproto=tcp");
 498                 break;
 499         default:
 500                 if (showdefaults)
 501                         seq_printf(m, ",mountproto=auto");
 502         }
 503 }
 504
 505 /*
 506  * Describe the mount options in force on this server representation
 507  */
 508 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 509                                    int showdefaults)
 510 {
 511         static const struct proc_nfs_info {
 512                 int flag;
 513                 const char *str;
 514                 const char *nostr;
 515         } nfs_info[] = {
 516                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 517                 { NFS_MOUNT_INTR, ",intr", ",nointr" },
 518                 { NFS_MOUNT_POSIX, ",posix", "" },
 519                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 520                 { NFS_MOUNT_NOAC, ",noac", "" },
 521                 { NFS_MOUNT_NONLM, ",nolock", "" },
 522                 { NFS_MOUNT_NOACL, ",noacl", "" },
 523                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 524                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 525                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 526                 { 0, NULL, NULL }
 527         };
 528         const struct proc_nfs_info *nfs_infop;
 529         struct nfs_client *clp = nfss->nfs_client;
 530         u32 version = clp->rpc_ops->version;
 531
 532         seq_printf(m, ",vers=%u", version);
 533         seq_printf(m, ",rsize=%u", nfss->rsize);
 534         seq_printf(m, ",wsize=%u", nfss->wsize);
 535         if (nfss->bsize != 0)
 536                 seq_printf(m, ",bsize=%u", nfss->bsize);
 537         seq_printf(m, ",namlen=%u", nfss->namelen);
 538         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 539                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 540         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 541                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 542         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 543                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 544         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 545                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 546         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 547                 if (nfss->flags & nfs_infop->flag)
 548                         seq_puts(m, nfs_infop->str);
 549                 else
 550                         seq_puts(m, nfs_infop->nostr);
 551         }
 552         seq_printf(m, ",proto=%s",
 553                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 554         if (version == 4) {
 555                 if (nfss->port != NFS_PORT)
 556                         seq_printf(m, ",port=%u", nfss->port);
 557         } else
 558                 if (nfss->port)
 559                         seq_printf(m, ",port=%u", nfss->port);
 560
 561         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 562         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 563         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 564
 565         if (version != 4)
 566                 nfs_show_mountd_options(m, nfss, showdefaults);
 567
 568 #ifdef CONFIG_NFS_V4
 569         if (clp->rpc_ops->version == 4)
 570                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 571 #endif
 572         if (nfss->options & NFS_OPTION_FSCACHE)
 573                 seq_printf(m, ",fsc");
 574 }
 575
 576 /*
 577  * Describe the mount options on this VFS mountpoint
 578  */
 579 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 580 {
 581         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 582
 583         nfs_show_mount_options(m, nfss, 0);
 584
 585         seq_printf(m, ",addr=%s",
 586                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 587                                                         RPC_DISPLAY_ADDR));
 588
 589         return 0;
 590 }
 591
 592 /*
 593  * Present statistical information for this VFS mountpoint
 594  */
 595 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 596 {
 597         int i, cpu;
 598         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 599         struct rpc_auth *auth = nfss->client->cl_auth;
 600         struct nfs_iostats totals = { };
 601
 602         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 603
 604         /*
 605          * Display all mount option settings
 606          */
 607         seq_printf(m, "\n\topts:\t");
 608         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 609         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 610         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 611         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 612         nfs_show_mount_options(m, nfss, 1);
 613
 614         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 615
 616         seq_printf(m, "\n\tcaps:\t");
 617         seq_printf(m, "caps=0x%x", nfss->caps);
 618         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 619         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 620         seq_printf(m, ",bsize=%u", nfss->bsize);
 621         seq_printf(m, ",namlen=%u", nfss->namelen);
 622
 623 #ifdef CONFIG_NFS_V4
 624         if (nfss->nfs_client->rpc_ops->version == 4) {
 625                 seq_printf(m, "\n\tnfsv4:\t");
 626                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 627                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 628                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 629         }
 630 #endif
 631
 632         /*
 633          * Display security flavor in effect for this mount
 634          */
 635         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 636         if (auth->au_flavor)
 637                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 638
 639         /*
 640          * Display superblock I/O counters
 641          */
 642         for_each_possible_cpu(cpu) {
 643                 struct nfs_iostats *stats;
 644
 645                 preempt_disable();
 646                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 647
 648                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 649                         totals.events[i] += stats->events[i];
 650                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 651                         totals.bytes[i] += stats->bytes[i];
 652 #ifdef CONFIG_NFS_FSCACHE
 653                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 654                         totals.fscache[i] += stats->fscache[i];
 655 #endif
 656
 657                 preempt_enable();
 658         }
 659
 660         seq_printf(m, "\n\tevents:\t");
 661         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 662                 seq_printf(m, "%lu ", totals.events[i]);
 663         seq_printf(m, "\n\tbytes:\t");
 664         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 665                 seq_printf(m, "%Lu ", totals.bytes[i]);
 666 #ifdef CONFIG_NFS_FSCACHE
 667         if (nfss->options & NFS_OPTION_FSCACHE) {
 668                 seq_printf(m, "\n\tfsc:\t");
 669                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 670                         seq_printf(m, "%Lu ", totals.bytes[i]);
 671         }
 672 #endif
 673         seq_printf(m, "\n");
 674
 675         rpc_print_iostats(m, nfss->client);
 676
 677         return 0;
 678 }
 679
 680 /*
 681  * Begin unmount by attempting to remove all automounted mountpoints we added
 682  * in response to xdev traversals and referrals
 683  */
 684 static void nfs_umount_begin(struct super_block *sb)
 685 {
 686         struct nfs_server *server;
 687         struct rpc_clnt *rpc;
 688
 689         lock_kernel();
 690
 691         server = NFS_SB(sb);
 692         /* -EIO all pending I/O */
 693         rpc = server->client_acl;
 694         if (!IS_ERR(rpc))
 695                 rpc_killall_tasks(rpc);
 696         rpc = server->client;
 697         if (!IS_ERR(rpc))
 698                 rpc_killall_tasks(rpc);
 699
 700         unlock_kernel();
 701 }
 702
 703 /*
 704  * Sanity-check a server address provided by the mount command.
 705  *
 706  * Address family must be initialized, and address must not be
 707  * the ANY address for that family.
 708  */
 709 static int nfs_verify_server_address(struct sockaddr *addr)
 710 {
 711         switch (addr->sa_family) {
 712         case AF_INET: {
 713                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 714                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 715         }
 716         case AF_INET6: {
 717                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 718                 return !ipv6_addr_any(sa);
 719         }
 720         }
 721
 722         return 0;
 723 }
 724
 725 static void nfs_parse_ipv4_address(char *string, size_t str_len,
 726                                    struct sockaddr *sap, size_t *addr_len)
 727 {
 728         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 729         u8 *addr = (u8 *)&sin->sin_addr.s_addr;
 730
 731         if (str_len <= INET_ADDRSTRLEN) {
 732                 dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
 733                                 (int)str_len, string);
 734
 735                 sin->sin_family = AF_INET;
 736                 *addr_len = sizeof(*sin);
 737                 if (in4_pton(string, str_len, addr, '\0', NULL))
 738                         return;
 739         }
 740
 741         sap->sa_family = AF_UNSPEC;
 742         *addr_len = 0;
 743 }
 744
 745 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 746 static int nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
 747                                    const char *delim,
 748                                    struct sockaddr_in6 *sin6)
 749 {
 750         char *p;
 751         size_t len;
 752
 753         if ((string + str_len) == delim)
 754                 return 1;
 755
 756         if (*delim != IPV6_SCOPE_DELIMITER)
 757                 return 0;
 758
 759         if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
 760                 return 0;
 761
 762         len = (string + str_len) - delim - 1;
 763         p = kstrndup(delim + 1, len, GFP_KERNEL);
 764         if (p) {
 765                 unsigned long scope_id = 0;
 766                 struct net_device *dev;
 767
 768                 dev = dev_get_by_name(&init_net, p);
 769                 if (dev != NULL) {
 770                         scope_id = dev->ifindex;
 771                         dev_put(dev);
 772                 } else {
 773                         if (strict_strtoul(p, 10, &scope_id) == 0) {
 774                                 kfree(p);
 775                                 return 0;
 776                         }
 777                 }
 778
 779                 kfree(p);
 780
 781                 sin6->sin6_scope_id = scope_id;
 782                 dfprintk(MOUNT, "NFS: IPv6 scope ID = %lu\n", scope_id);
 783                 return 1;
 784         }
 785
 786         return 0;
 787 }
 788
 789 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 790                                    struct sockaddr *sap, size_t *addr_len)
 791 {
 792         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 793         u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
 794         const char *delim;
 795
 796         if (str_len <= INET6_ADDRSTRLEN) {
 797                 dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
 798                                 (int)str_len, string);
 799
 800                 sin6->sin6_family = AF_INET6;
 801                 *addr_len = sizeof(*sin6);
 802                 if (in6_pton(string, str_len, addr,
 803                                         IPV6_SCOPE_DELIMITER, &delim) != 0) {
 804                         if (nfs_parse_ipv6_scope_id(string, str_len,
 805                                                         delim, sin6) != 0)
 806                                 return;
 807                 }
 808         }
 809
 810         sap->sa_family = AF_UNSPEC;
 811         *addr_len = 0;
 812 }
 813 #else
 814 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 815                                    struct sockaddr *sap, size_t *addr_len)
 816 {
 817         sap->sa_family = AF_UNSPEC;
 818         *addr_len = 0;
 819 }
 820 #endif
 821
 822 /*
 823  * Construct a sockaddr based on the contents of a string that contains
 824  * an IP address in presentation format.
 825  *
 826  * If there is a problem constructing the new sockaddr, set the address
 827  * family to AF_UNSPEC.
 828  */
 829 void nfs_parse_ip_address(char *string, size_t str_len,
 830                                  struct sockaddr *sap, size_t *addr_len)
 831 {
 832         unsigned int i, colons;
 833
 834         colons = 0;
 835         for (i = 0; i < str_len; i++)
 836                 if (string[i] == ':')
 837                         colons++;
 838
 839         if (colons >= 2)
 840                 nfs_parse_ipv6_address(string, str_len, sap, addr_len);
 841         else
 842                 nfs_parse_ipv4_address(string, str_len, sap, addr_len);
 843 }
 844
 845 /*
 846  * Sanity check the NFS transport protocol.
 847  *
 848  */
 849 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 850 {
 851         switch (mnt->nfs_server.protocol) {
 852         case XPRT_TRANSPORT_UDP:
 853         case XPRT_TRANSPORT_TCP:
 854         case XPRT_TRANSPORT_RDMA:
 855                 break;
 856         default:
 857                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 858         }
 859 }
 860
 861 /*
 862  * For text based NFSv2/v3 mounts, the mount protocol transport default
 863  * settings should depend upon the specified NFS transport.
 864  */
 865 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 866 {
 867         nfs_validate_transport_protocol(mnt);
 868
 869         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 870             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 871                         return;
 872         switch (mnt->nfs_server.protocol) {
 873         case XPRT_TRANSPORT_UDP:
 874                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 875                 break;
 876         case XPRT_TRANSPORT_TCP:
 877         case XPRT_TRANSPORT_RDMA:
 878                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 879         }
 880 }
 881
 882 /*
 883  * Parse the value of the 'sec=' option.
 884  *
 885  * The flavor_len setting is for v4 mounts.
 886  */
 887 static int nfs_parse_security_flavors(char *value,
 888                                       struct nfs_parsed_mount_data *mnt)
 889 {
 890         substring_t args[MAX_OPT_ARGS];
 891
 892         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 893
 894         switch (match_token(value, nfs_secflavor_tokens, args)) {
 895         case Opt_sec_none:
 896                 mnt->auth_flavor_len = 0;
 897                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 898                 break;
 899         case Opt_sec_sys:
 900                 mnt->auth_flavor_len = 0;
 901                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 902                 break;
 903         case Opt_sec_krb5:
 904                 mnt->auth_flavor_len = 1;
 905                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 906                 break;
 907         case Opt_sec_krb5i:
 908                 mnt->auth_flavor_len = 1;
 909                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 910                 break;
 911         case Opt_sec_krb5p:
 912                 mnt->auth_flavor_len = 1;
 913                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 914                 break;
 915         case Opt_sec_lkey:
 916                 mnt->auth_flavor_len = 1;
 917                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 918                 break;
 919         case Opt_sec_lkeyi:
 920                 mnt->auth_flavor_len = 1;
 921                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 922                 break;
 923         case Opt_sec_lkeyp:
 924                 mnt->auth_flavor_len = 1;
 925                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 926                 break;
 927         case Opt_sec_spkm:
 928                 mnt->auth_flavor_len = 1;
 929                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 930                 break;
 931         case Opt_sec_spkmi:
 932                 mnt->auth_flavor_len = 1;
 933                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 934                 break;
 935         case Opt_sec_spkmp:
 936                 mnt->auth_flavor_len = 1;
 937                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 938                 break;
 939         default:
 940                 return 0;
 941         }
 942
 943         return 1;
 944 }
 945
 946 static void nfs_parse_invalid_value(const char *option)
 947 {
 948         dfprintk(MOUNT, "NFS:   bad value specified for %s option\n", option);
 949 }
 950
 951 /*
 952  * Error-check and convert a string of mount options from user space into
 953  * a data structure.  The whole mount string is processed; bad options are
 954  * skipped as they are encountered.  If there were no errors, return 1;
 955  * otherwise return 0 (zero).
 956  */
 957 static int nfs_parse_mount_options(char *raw,
 958                                    struct nfs_parsed_mount_data *mnt)
 959 {
 960         char *p, *string, *secdata;
 961         int rc, sloppy = 0, errors = 0;
 962
 963         if (!raw) {
 964                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 965                 return 1;
 966         }
 967         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 968
 969         secdata = alloc_secdata();
 970         if (!secdata)
 971                 goto out_nomem;
 972
 973         rc = security_sb_copy_data(raw, secdata);
 974         if (rc)
 975                 goto out_security_failure;
 976
 977         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 978         if (rc)
 979                 goto out_security_failure;
 980
 981         free_secdata(secdata);
 982
 983         while ((p = strsep(&raw, ",")) != NULL) {
 984                 substring_t args[MAX_OPT_ARGS];
 985                 int option, token;
 986
 987                 if (!*p)
 988                         continue;
 989
 990                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 991
 992                 token = match_token(p, nfs_mount_option_tokens, args);
 993                 switch (token) {
 994
 995                 /*
 996                  * boolean options:  foo/nofoo
 997                  */
 998                 case Opt_soft:
 999                         mnt->flags |= NFS_MOUNT_SOFT;
1000                         break;
1001                 case Opt_hard:
1002                         mnt->flags &= ~NFS_MOUNT_SOFT;
1003                         break;
1004                 case Opt_posix:
1005                         mnt->flags |= NFS_MOUNT_POSIX;
1006                         break;
1007                 case Opt_noposix:
1008                         mnt->flags &= ~NFS_MOUNT_POSIX;
1009                         break;
1010                 case Opt_cto:
1011                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1012                         break;
1013                 case Opt_nocto:
1014                         mnt->flags |= NFS_MOUNT_NOCTO;
1015                         break;
1016                 case Opt_ac:
1017                         mnt->flags &= ~NFS_MOUNT_NOAC;
1018                         break;
1019                 case Opt_noac:
1020                         mnt->flags |= NFS_MOUNT_NOAC;
1021                         break;
1022                 case Opt_lock:
1023                         mnt->flags &= ~NFS_MOUNT_NONLM;
1024                         break;
1025                 case Opt_nolock:
1026                         mnt->flags |= NFS_MOUNT_NONLM;
1027                         break;
1028                 case Opt_v2:
1029                         mnt->flags &= ~NFS_MOUNT_VER3;
1030                         break;
1031                 case Opt_v3:
1032                         mnt->flags |= NFS_MOUNT_VER3;
1033                         break;
1034                 case Opt_udp:
1035                         mnt->flags &= ~NFS_MOUNT_TCP;
1036                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1037                         break;
1038                 case Opt_tcp:
1039                         mnt->flags |= NFS_MOUNT_TCP;
1040                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1041                         break;
1042                 case Opt_rdma:
1043                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1044                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1045                         xprt_load_transport(p);
1046                         break;
1047                 case Opt_acl:
1048                         mnt->flags &= ~NFS_MOUNT_NOACL;
1049                         break;
1050                 case Opt_noacl:
1051                         mnt->flags |= NFS_MOUNT_NOACL;
1052                         break;
1053                 case Opt_rdirplus:
1054                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1055                         break;
1056                 case Opt_nordirplus:
1057                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1058                         break;
1059                 case Opt_sharecache:
1060                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1061                         break;
1062                 case Opt_nosharecache:
1063                         mnt->flags |= NFS_MOUNT_UNSHARED;
1064                         break;
1065                 case Opt_resvport:
1066                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1067                         break;
1068                 case Opt_noresvport:
1069                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1070                         break;
1071                 case Opt_fscache:
1072                         mnt->options |= NFS_OPTION_FSCACHE;
1073                         kfree(mnt->fscache_uniq);
1074                         mnt->fscache_uniq = NULL;
1075                         break;
1076                 case Opt_nofscache:
1077                         mnt->options &= ~NFS_OPTION_FSCACHE;
1078                         kfree(mnt->fscache_uniq);
1079                         mnt->fscache_uniq = NULL;
1080                         break;
1081                 case Opt_fscache_uniq:
1082                         string = match_strdup(args);
1083                         if (!string)
1084                                 goto out_nomem;
1085                         kfree(mnt->fscache_uniq);
1086                         mnt->fscache_uniq = string;
1087                         mnt->options |= NFS_OPTION_FSCACHE;
1088                         break;
1089
1090                 /*
1091                  * options that take numeric values
1092                  */
1093                 case Opt_port:
1094                         if (match_int(args, &option) ||
1095                             option < 0 || option > USHORT_MAX) {
1096                                 errors++;
1097                                 nfs_parse_invalid_value("port");
1098                         } else
1099                                 mnt->nfs_server.port = option;
1100                         break;
1101                 case Opt_rsize:
1102                         if (match_int(args, &option) || option < 0) {
1103                                 errors++;
1104                                 nfs_parse_invalid_value("rsize");
1105                         } else
1106                                 mnt->rsize = option;
1107                         break;
1108                 case Opt_wsize:
1109                         if (match_int(args, &option) || option < 0) {
1110                                 errors++;
1111                                 nfs_parse_invalid_value("wsize");
1112                         } else
1113                                 mnt->wsize = option;
1114                         break;
1115                 case Opt_bsize:
1116                         if (match_int(args, &option) || option < 0) {
1117                                 errors++;
1118                                 nfs_parse_invalid_value("bsize");
1119                         } else
1120                                 mnt->bsize = option;
1121                         break;
1122                 case Opt_timeo:
1123                         if (match_int(args, &option) || option <= 0) {
1124                                 errors++;
1125                                 nfs_parse_invalid_value("timeo");
1126                         } else
1127                                 mnt->timeo = option;
1128                         break;
1129                 case Opt_retrans:
1130                         if (match_int(args, &option) || option <= 0) {
1131                                 errors++;
1132                                 nfs_parse_invalid_value("retrans");
1133                         } else
1134                                 mnt->retrans = option;
1135                         break;
1136                 case Opt_acregmin:
1137                         if (match_int(args, &option) || option < 0) {
1138                                 errors++;
1139                                 nfs_parse_invalid_value("acregmin");
1140                         } else
1141                                 mnt->acregmin = option;
1142                         break;
1143                 case Opt_acregmax:
1144                         if (match_int(args, &option) || option < 0) {
1145                                 errors++;
1146                                 nfs_parse_invalid_value("acregmax");
1147                         } else
1148                                 mnt->acregmax = option;
1149                         break;
1150                 case Opt_acdirmin:
1151                         if (match_int(args, &option) || option < 0) {
1152                                 errors++;
1153                                 nfs_parse_invalid_value("acdirmin");
1154                         } else
1155                                 mnt->acdirmin = option;
1156                         break;
1157                 case Opt_acdirmax:
1158                         if (match_int(args, &option) || option < 0) {
1159                                 errors++;
1160                                 nfs_parse_invalid_value("acdirmax");
1161                         } else
1162                                 mnt->acdirmax = option;
1163                         break;
1164                 case Opt_actimeo:
1165                         if (match_int(args, &option) || option < 0) {
1166                                 errors++;
1167                                 nfs_parse_invalid_value("actimeo");
1168                         } else
1169                                 mnt->acregmin = mnt->acregmax =
1170                                 mnt->acdirmin = mnt->acdirmax = option;
1171                         break;
1172                 case Opt_namelen:
1173                         if (match_int(args, &option) || option < 0) {
1174                                 errors++;
1175                                 nfs_parse_invalid_value("namlen");
1176                         } else
1177                                 mnt->namlen = option;
1178                         break;
1179                 case Opt_mountport:
1180                         if (match_int(args, &option) ||
1181                             option < 0 || option > USHORT_MAX) {
1182                                 errors++;
1183                                 nfs_parse_invalid_value("mountport");
1184                         } else
1185                                 mnt->mount_server.port = option;
1186                         break;
1187                 case Opt_mountvers:
1188                         if (match_int(args, &option) ||
1189                             option < NFS_MNT_VERSION ||
1190                             option > NFS_MNT3_VERSION) {
1191                                 errors++;
1192                                 nfs_parse_invalid_value("mountvers");
1193                         } else
1194                                 mnt->mount_server.version = option;
1195                         break;
1196                 case Opt_nfsvers:
1197                         if (match_int(args, &option)) {
1198                                 errors++;
1199                                 nfs_parse_invalid_value("nfsvers");
1200                                 break;
1201                         }
1202                         switch (option) {
1203                         case NFS2_VERSION:
1204                                 mnt->flags &= ~NFS_MOUNT_VER3;
1205                                 break;
1206                         case NFS3_VERSION:
1207                                 mnt->flags |= NFS_MOUNT_VER3;
1208                                 break;
1209                         default:
1210                                 errors++;
1211                                 nfs_parse_invalid_value("nfsvers");
1212                         }
1213                         break;
1214
1215                 /*
1216                  * options that take text values
1217                  */
1218                 case Opt_sec:
1219                         string = match_strdup(args);
1220                         if (string == NULL)
1221                                 goto out_nomem;
1222                         rc = nfs_parse_security_flavors(string, mnt);
1223                         kfree(string);
1224                         if (!rc) {
1225                                 errors++;
1226                                 dfprintk(MOUNT, "NFS:   unrecognized "
1227                                                 "security flavor\n");
1228                         }
1229                         break;
1230                 case Opt_proto:
1231                         string = match_strdup(args);
1232                         if (string == NULL)
1233                                 goto out_nomem;
1234                         token = match_token(string,
1235                                             nfs_xprt_protocol_tokens, args);
1236
1237                         switch (token) {
1238                         case Opt_xprt_udp:
1239                                 mnt->flags &= ~NFS_MOUNT_TCP;
1240                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1241                                 break;
1242                         case Opt_xprt_tcp:
1243                                 mnt->flags |= NFS_MOUNT_TCP;
1244                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1245                                 break;
1246                         case Opt_xprt_rdma:
1247                                 /* vector side protocols to TCP */
1248                                 mnt->flags |= NFS_MOUNT_TCP;
1249                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1250                                 xprt_load_transport(string);
1251                                 break;
1252                         default:
1253                                 errors++;
1254                                 dfprintk(MOUNT, "NFS:   unrecognized "
1255                                                 "transport protocol\n");
1256                         }
1257                         kfree(string);
1258                         break;
1259                 case Opt_mountproto:
1260                         string = match_strdup(args);
1261                         if (string == NULL)
1262                                 goto out_nomem;
1263                         token = match_token(string,
1264                                             nfs_xprt_protocol_tokens, args);
1265                         kfree(string);
1266
1267                         switch (token) {
1268                         case Opt_xprt_udp:
1269                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1270                                 break;
1271                         case Opt_xprt_tcp:
1272                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1273                                 break;
1274                         case Opt_xprt_rdma: /* not used for side protocols */
1275                         default:
1276                                 errors++;
1277                                 dfprintk(MOUNT, "NFS:   unrecognized "
1278                                                 "transport protocol\n");
1279                         }
1280                         break;
1281                 case Opt_addr:
1282                         string = match_strdup(args);
1283                         if (string == NULL)
1284                                 goto out_nomem;
1285                         nfs_parse_ip_address(string, strlen(string),
1286                                              (struct sockaddr *)
1287                                                 &mnt->nfs_server.address,
1288                                              &mnt->nfs_server.addrlen);
1289                         kfree(string);
1290                         break;
1291                 case Opt_clientaddr:
1292                         string = match_strdup(args);
1293                         if (string == NULL)
1294                                 goto out_nomem;
1295                         kfree(mnt->client_address);
1296                         mnt->client_address = string;
1297                         break;
1298                 case Opt_mounthost:
1299                         string = match_strdup(args);
1300                         if (string == NULL)
1301                                 goto out_nomem;
1302                         kfree(mnt->mount_server.hostname);
1303                         mnt->mount_server.hostname = string;
1304                         break;
1305                 case Opt_mountaddr:
1306                         string = match_strdup(args);
1307                         if (string == NULL)
1308                                 goto out_nomem;
1309                         nfs_parse_ip_address(string, strlen(string),
1310                                              (struct sockaddr *)
1311                                                 &mnt->mount_server.address,
1312                                              &mnt->mount_server.addrlen);
1313                         kfree(string);
1314                         break;
1315                 case Opt_lookupcache:
1316                         string = match_strdup(args);
1317                         if (string == NULL)
1318                                 goto out_nomem;
1319                         token = match_token(string,
1320                                         nfs_lookupcache_tokens, args);
1321                         kfree(string);
1322                         switch (token) {
1323                                 case Opt_lookupcache_all:
1324                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1325                                         break;
1326                                 case Opt_lookupcache_positive:
1327                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1328                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1329                                         break;
1330                                 case Opt_lookupcache_none:
1331                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1332                                         break;
1333                                 default:
1334                                         errors++;
1335                                         dfprintk(MOUNT, "NFS:   invalid "
1336                                                         "lookupcache argument\n");
1337                         };
1338                         break;
1339
1340                 /*
1341                  * Special options
1342                  */
1343                 case Opt_sloppy:
1344                         sloppy = 1;
1345                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1346                         break;
1347                 case Opt_userspace:
1348                 case Opt_deprecated:
1349                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1350                                         "'%s'\n", p);
1351                         break;
1352
1353                 default:
1354                         errors++;
1355                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1356                                         "'%s'\n", p);
1357                 }
1358         }
1359
1360         if (errors > 0) {
1361                 dfprintk(MOUNT, "NFS: parsing encountered %d error%s\n",
1362                                 errors, (errors == 1 ? "" : "s"));
1363                 if (!sloppy)
1364                         return 0;
1365         }
1366         return 1;
1367
1368 out_nomem:
1369         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1370         return 0;
1371 out_security_failure:
1372         free_secdata(secdata);
1373         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1374         return 0;
1375 }
1376
1377 /*
1378  * Use the remote server's MOUNT service to request the NFS file handle
1379  * corresponding to the provided path.
1380  */
1381 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1382                          struct nfs_fh *root_fh)
1383 {
1384         struct nfs_mount_request request = {
1385                 .sap            = (struct sockaddr *)
1386                                                 &args->mount_server.address,
1387                 .dirpath        = args->nfs_server.export_path,
1388                 .protocol       = args->mount_server.protocol,
1389                 .fh             = root_fh,
1390                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1391         };
1392         int status;
1393
1394         if (args->mount_server.version == 0) {
1395                 if (args->flags & NFS_MOUNT_VER3)
1396                         args->mount_server.version = NFS_MNT3_VERSION;
1397                 else
1398                         args->mount_server.version = NFS_MNT_VERSION;
1399         }
1400         request.version = args->mount_server.version;
1401
1402         if (args->mount_server.hostname)
1403                 request.hostname = args->mount_server.hostname;
1404         else
1405                 request.hostname = args->nfs_server.hostname;
1406
1407         /*
1408          * Construct the mount server's address.
1409          */
1410         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1411                 memcpy(request.sap, &args->nfs_server.address,
1412                        args->nfs_server.addrlen);
1413                 args->mount_server.addrlen = args->nfs_server.addrlen;
1414         }
1415         request.salen = args->mount_server.addrlen;
1416
1417         /*
1418          * autobind will be used if mount_server.port == 0
1419          */
1420         nfs_set_port(request.sap, args->mount_server.port);
1421
1422         /*
1423          * Now ask the mount server to map our export path
1424          * to a file handle.
1425          */
1426         status = nfs_mount(&request);
1427         if (status == 0)
1428                 return 0;
1429
1430         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1431                         request.hostname, status);
1432         return status;
1433 }
1434
1435 static int nfs_parse_simple_hostname(const char *dev_name,
1436                                      char **hostname, size_t maxnamlen,
1437                                      char **export_path, size_t maxpathlen)
1438 {
1439         size_t len;
1440         char *colon, *comma;
1441
1442         colon = strchr(dev_name, ':');
1443         if (colon == NULL)
1444                 goto out_bad_devname;
1445
1446         len = colon - dev_name;
1447         if (len > maxnamlen)
1448                 goto out_hostname;
1449
1450         /* N.B. caller will free nfs_server.hostname in all cases */
1451         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1452         if (!*hostname)
1453                 goto out_nomem;
1454
1455         /* kill possible hostname list: not supported */
1456         comma = strchr(*hostname, ',');
1457         if (comma != NULL) {
1458                 if (comma == *hostname)
1459                         goto out_bad_devname;
1460                 *comma = '\0';
1461         }
1462
1463         colon++;
1464         len = strlen(colon);
1465         if (len > maxpathlen)
1466                 goto out_path;
1467         *export_path = kstrndup(colon, len, GFP_KERNEL);
1468         if (!*export_path)
1469                 goto out_nomem;
1470
1471         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1472         return 0;
1473
1474 out_bad_devname:
1475         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1476         return -EINVAL;
1477
1478 out_nomem:
1479         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1480         return -ENOMEM;
1481
1482 out_hostname:
1483         dfprintk(MOUNT, "NFS: server hostname too long\n");
1484         return -ENAMETOOLONG;
1485
1486 out_path:
1487         dfprintk(MOUNT, "NFS: export pathname too long\n");
1488         return -ENAMETOOLONG;
1489 }
1490
1491 /*
1492  * Hostname has square brackets around it because it contains one or
1493  * more colons.  We look for the first closing square bracket, and a
1494  * colon must follow it.
1495  */
1496 static int nfs_parse_protected_hostname(const char *dev_name,
1497                                         char **hostname, size_t maxnamlen,
1498                                         char **export_path, size_t maxpathlen)
1499 {
1500         size_t len;
1501         char *start, *end;
1502
1503         start = (char *)(dev_name + 1);
1504
1505         end = strchr(start, ']');
1506         if (end == NULL)
1507                 goto out_bad_devname;
1508         if (*(end + 1) != ':')
1509                 goto out_bad_devname;
1510
1511         len = end - start;
1512         if (len > maxnamlen)
1513                 goto out_hostname;
1514
1515         /* N.B. caller will free nfs_server.hostname in all cases */
1516         *hostname = kstrndup(start, len, GFP_KERNEL);
1517         if (*hostname == NULL)
1518                 goto out_nomem;
1519
1520         end += 2;
1521         len = strlen(end);
1522         if (len > maxpathlen)
1523                 goto out_path;
1524         *export_path = kstrndup(end, len, GFP_KERNEL);
1525         if (!*export_path)
1526                 goto out_nomem;
1527
1528         return 0;
1529
1530 out_bad_devname:
1531         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1532         return -EINVAL;
1533
1534 out_nomem:
1535         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1536         return -ENOMEM;
1537
1538 out_hostname:
1539         dfprintk(MOUNT, "NFS: server hostname too long\n");
1540         return -ENAMETOOLONG;
1541
1542 out_path:
1543         dfprintk(MOUNT, "NFS: export pathname too long\n");
1544         return -ENAMETOOLONG;
1545 }
1546
1547 /*
1548  * Split "dev_name" into "hostname:export_path".
1549  *
1550  * The leftmost colon demarks the split between the server's hostname
1551  * and the export path.  If the hostname starts with a left square
1552  * bracket, then it may contain colons.
1553  *
1554  * Note: caller frees hostname and export path, even on error.
1555  */
1556 static int nfs_parse_devname(const char *dev_name,
1557                              char **hostname, size_t maxnamlen,
1558                              char **export_path, size_t maxpathlen)
1559 {
1560         if (*dev_name == '[')
1561                 return nfs_parse_protected_hostname(dev_name,
1562                                                     hostname, maxnamlen,
1563                                                     export_path, maxpathlen);
1564
1565         return nfs_parse_simple_hostname(dev_name,
1566                                          hostname, maxnamlen,
1567                                          export_path, maxpathlen);
1568 }
1569
1570 /*
1571  * Validate the NFS2/NFS3 mount data
1572  * - fills in the mount root filehandle
1573  *
1574  * For option strings, user space handles the following behaviors:
1575  *
1576  * + DNS: mapping server host name to IP address ("addr=" option)
1577  *
1578  * + failure mode: how to behave if a mount request can't be handled
1579  *   immediately ("fg/bg" option)
1580  *
1581  * + retry: how often to retry a mount request ("retry=" option)
1582  *
1583  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1584  *   mountproto=tcp after mountproto=udp, and so on
1585  */
1586 static int nfs_validate_mount_data(void *options,
1587                                    struct nfs_parsed_mount_data *args,
1588                                    struct nfs_fh *mntfh,
1589                                    const char *dev_name)
1590 {
1591         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1592
1593         if (data == NULL)
1594                 goto out_no_data;
1595
1596         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1597         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1598         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1599         args->acregmin          = NFS_DEF_ACREGMIN;
1600         args->acregmax          = NFS_DEF_ACREGMAX;
1601         args->acdirmin          = NFS_DEF_ACDIRMIN;
1602         args->acdirmax          = NFS_DEF_ACDIRMAX;
1603         args->mount_server.port = 0;    /* autobind unless user sets port */
1604         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1605         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1606         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1607
1608         switch (data->version) {
1609         case 1:
1610                 data->namlen = 0;
1611         case 2:
1612                 data->bsize = 0;
1613         case 3:
1614                 if (data->flags & NFS_MOUNT_VER3)
1615                         goto out_no_v3;
1616                 data->root.size = NFS2_FHSIZE;
1617                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1618         case 4:
1619                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1620                         goto out_no_sec;
1621         case 5:
1622                 memset(data->context, 0, sizeof(data->context));
1623         case 6:
1624                 if (data->flags & NFS_MOUNT_VER3) {
1625                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1626                                 goto out_invalid_fh;
1627                         mntfh->size = data->root.size;
1628                 } else
1629                         mntfh->size = NFS2_FHSIZE;
1630
1631
1632                 memcpy(mntfh->data, data->root.data, mntfh->size);
1633                 if (mntfh->size < sizeof(mntfh->data))
1634                         memset(mntfh->data + mntfh->size, 0,
1635                                sizeof(mntfh->data) - mntfh->size);
1636
1637                 /*
1638                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1639                  * can deal with.
1640                  */
1641                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1642                 args->rsize             = data->rsize;
1643                 args->wsize             = data->wsize;
1644                 args->timeo             = data->timeo;
1645                 args->retrans           = data->retrans;
1646                 args->acregmin          = data->acregmin;
1647                 args->acregmax          = data->acregmax;
1648                 args->acdirmin          = data->acdirmin;
1649                 args->acdirmax          = data->acdirmax;
1650
1651                 memcpy(&args->nfs_server.address, &data->addr,
1652                        sizeof(data->addr));
1653                 args->nfs_server.addrlen = sizeof(data->addr);
1654                 if (!nfs_verify_server_address((struct sockaddr *)
1655                                                 &args->nfs_server.address))
1656                         goto out_no_address;
1657
1658                 if (!(data->flags & NFS_MOUNT_TCP))
1659                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1660                 /* N.B. caller will free nfs_server.hostname in all cases */
1661                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1662                 args->namlen            = data->namlen;
1663                 args->bsize             = data->bsize;
1664
1665                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1666                         args->auth_flavors[0] = data->pseudoflavor;
1667                 if (!args->nfs_server.hostname)
1668                         goto out_nomem;
1669
1670                 /*
1671                  * The legacy version 6 binary mount data from userspace has a
1672                  * field used only to transport selinux information into the
1673                  * the kernel.  To continue to support that functionality we
1674                  * have a touch of selinux knowledge here in the NFS code. The
1675                  * userspace code converted context=blah to just blah so we are
1676                  * converting back to the full string selinux understands.
1677                  */
1678                 if (data->context[0]){
1679 #ifdef CONFIG_SECURITY_SELINUX
1680                         int rc;
1681                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1682                         if (!opts_str)
1683                                 return -ENOMEM;
1684                         strcpy(opts_str, "context=");
1685                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1686                         strcat(opts_str, &data->context[0]);
1687                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1688                         kfree(opts_str);
1689                         if (rc)
1690                                 return rc;
1691 #else
1692                         return -EINVAL;
1693 #endif
1694                 }
1695
1696                 break;
1697         default: {
1698                 int status;
1699
1700                 if (nfs_parse_mount_options((char *)options, args) == 0)
1701                         return -EINVAL;
1702
1703                 if (!nfs_verify_server_address((struct sockaddr *)
1704                                                 &args->nfs_server.address))
1705                         goto out_no_address;
1706
1707                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
1708                                 args->nfs_server.port);
1709
1710                 nfs_set_mount_transport_protocol(args);
1711
1712                 status = nfs_parse_devname(dev_name,
1713                                            &args->nfs_server.hostname,
1714                                            PAGE_SIZE,
1715                                            &args->nfs_server.export_path,
1716                                            NFS_MAXPATHLEN);
1717                 if (!status)
1718                         status = nfs_try_mount(args, mntfh);
1719
1720                 kfree(args->nfs_server.export_path);
1721                 args->nfs_server.export_path = NULL;
1722
1723                 if (status)
1724                         return status;
1725
1726                 break;
1727                 }
1728         }
1729
1730 #ifndef CONFIG_NFS_V3
1731         if (args->flags & NFS_MOUNT_VER3)
1732                 goto out_v3_not_compiled;
1733 #endif /* !CONFIG_NFS_V3 */
1734
1735         return 0;
1736
1737 out_no_data:
1738         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1739         return -EINVAL;
1740
1741 out_no_v3:
1742         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1743                  data->version);
1744         return -EINVAL;
1745
1746 out_no_sec:
1747         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1748         return -EINVAL;
1749
1750 #ifndef CONFIG_NFS_V3
1751 out_v3_not_compiled:
1752         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1753         return -EPROTONOSUPPORT;
1754 #endif /* !CONFIG_NFS_V3 */
1755
1756 out_nomem:
1757         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1758         return -ENOMEM;
1759
1760 out_no_address:
1761         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1762         return -EINVAL;
1763
1764 out_invalid_fh:
1765         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1766         return -EINVAL;
1767 }
1768
1769 static int
1770 nfs_compare_remount_data(struct nfs_server *nfss,
1771                          struct nfs_parsed_mount_data *data)
1772 {
1773         if (data->flags != nfss->flags ||
1774             data->rsize != nfss->rsize ||
1775             data->wsize != nfss->wsize ||
1776             data->retrans != nfss->client->cl_timeout->to_retries ||
1777             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1778             data->acregmin != nfss->acregmin / HZ ||
1779             data->acregmax != nfss->acregmax / HZ ||
1780             data->acdirmin != nfss->acdirmin / HZ ||
1781             data->acdirmax != nfss->acdirmax / HZ ||
1782             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1783             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1784             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1785                    data->nfs_server.addrlen) != 0)
1786                 return -EINVAL;
1787
1788         return 0;
1789 }
1790
1791 static int
1792 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1793 {
1794         int error;
1795         struct nfs_server *nfss = sb->s_fs_info;
1796         struct nfs_parsed_mount_data *data;
1797         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1798         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1799         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1800
1801         /*
1802          * Userspace mount programs that send binary options generally send
1803          * them populated with default values. We have no way to know which
1804          * ones were explicitly specified. Fall back to legacy behavior and
1805          * just return success.
1806          */
1807         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1808             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1809                                            options->version <= 6))))
1810                 return 0;
1811
1812         data = kzalloc(sizeof(*data), GFP_KERNEL);
1813         if (data == NULL)
1814                 return -ENOMEM;
1815
1816         lock_kernel();
1817         /* fill out struct with values from existing mount */
1818         data->flags = nfss->flags;
1819         data->rsize = nfss->rsize;
1820         data->wsize = nfss->wsize;
1821         data->retrans = nfss->client->cl_timeout->to_retries;
1822         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1823         data->acregmin = nfss->acregmin / HZ;
1824         data->acregmax = nfss->acregmax / HZ;
1825         data->acdirmin = nfss->acdirmin / HZ;
1826         data->acdirmax = nfss->acdirmax / HZ;
1827         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1828         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1829         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1830                 data->nfs_server.addrlen);
1831
1832         /* overwrite those values with any that were specified */
1833         error = nfs_parse_mount_options((char *)options, data);
1834         if (error < 0)
1835                 goto out;
1836
1837         /* compare new mount options with old ones */
1838         error = nfs_compare_remount_data(nfss, data);
1839 out:
1840         kfree(data);
1841         unlock_kernel();
1842         return error;
1843 }
1844
1845 /*
1846  * Initialise the common bits of the superblock
1847  */
1848 static inline void nfs_initialise_sb(struct super_block *sb)
1849 {
1850         struct nfs_server *server = NFS_SB(sb);
1851
1852         sb->s_magic = NFS_SUPER_MAGIC;
1853
1854         /* We probably want something more informative here */
1855         snprintf(sb->s_id, sizeof(sb->s_id),
1856                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1857
1858         if (sb->s_blocksize == 0)
1859                 sb->s_blocksize = nfs_block_bits(server->wsize,
1860                                                  &sb->s_blocksize_bits);
1861
1862         if (server->flags & NFS_MOUNT_NOAC)
1863                 sb->s_flags |= MS_SYNCHRONOUS;
1864
1865         nfs_super_set_maxbytes(sb, server->maxfilesize);
1866 }
1867
1868 /*
1869  * Finish setting up an NFS2/3 superblock
1870  */
1871 static void nfs_fill_super(struct super_block *sb,
1872                            struct nfs_parsed_mount_data *data)
1873 {
1874         struct nfs_server *server = NFS_SB(sb);
1875
1876         sb->s_blocksize_bits = 0;
1877         sb->s_blocksize = 0;
1878         if (data->bsize)
1879                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1880
1881         if (server->flags & NFS_MOUNT_VER3) {
1882                 /* The VFS shouldn't apply the umask to mode bits. We will do
1883                  * so ourselves when necessary.
1884                  */
1885                 sb->s_flags |= MS_POSIXACL;
1886                 sb->s_time_gran = 1;
1887         }
1888
1889         sb->s_op = &nfs_sops;
1890         nfs_initialise_sb(sb);
1891 }
1892
1893 /*
1894  * Finish setting up a cloned NFS2/3 superblock
1895  */
1896 static void nfs_clone_super(struct super_block *sb,
1897                             const struct super_block *old_sb)
1898 {
1899         struct nfs_server *server = NFS_SB(sb);
1900
1901         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1902         sb->s_blocksize = old_sb->s_blocksize;
1903         sb->s_maxbytes = old_sb->s_maxbytes;
1904
1905         if (server->flags & NFS_MOUNT_VER3) {
1906                 /* The VFS shouldn't apply the umask to mode bits. We will do
1907                  * so ourselves when necessary.
1908                  */
1909                 sb->s_flags |= MS_POSIXACL;
1910                 sb->s_time_gran = 1;
1911         }
1912
1913         sb->s_op = old_sb->s_op;
1914         nfs_initialise_sb(sb);
1915 }
1916
1917 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1918 {
1919         const struct nfs_server *a = s->s_fs_info;
1920         const struct rpc_clnt *clnt_a = a->client;
1921         const struct rpc_clnt *clnt_b = b->client;
1922
1923         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1924                 goto Ebusy;
1925         if (a->nfs_client != b->nfs_client)
1926                 goto Ebusy;
1927         if (a->flags != b->flags)
1928                 goto Ebusy;
1929         if (a->wsize != b->wsize)
1930                 goto Ebusy;
1931         if (a->rsize != b->rsize)
1932                 goto Ebusy;
1933         if (a->acregmin != b->acregmin)
1934                 goto Ebusy;
1935         if (a->acregmax != b->acregmax)
1936                 goto Ebusy;
1937         if (a->acdirmin != b->acdirmin)
1938                 goto Ebusy;
1939         if (a->acdirmax != b->acdirmax)
1940                 goto Ebusy;
1941         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1942                 goto Ebusy;
1943         return 1;
1944 Ebusy:
1945         return 0;
1946 }
1947
1948 struct nfs_sb_mountdata {
1949         struct nfs_server *server;
1950         int mntflags;
1951 };
1952
1953 static int nfs_set_super(struct super_block *s, void *data)
1954 {
1955         struct nfs_sb_mountdata *sb_mntdata = data;
1956         struct nfs_server *server = sb_mntdata->server;
1957         int ret;
1958
1959         s->s_flags = sb_mntdata->mntflags;
1960         s->s_fs_info = server;
1961         ret = set_anon_super(s, server);
1962         if (ret == 0)
1963                 server->s_dev = s->s_dev;
1964         return ret;
1965 }
1966
1967 static int nfs_compare_super_address(struct nfs_server *server1,
1968                                      struct nfs_server *server2)
1969 {
1970         struct sockaddr *sap1, *sap2;
1971
1972         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1973         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1974
1975         if (sap1->sa_family != sap2->sa_family)
1976                 return 0;
1977
1978         switch (sap1->sa_family) {
1979         case AF_INET: {
1980                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1981                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1982                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1983                         return 0;
1984                 if (sin1->sin_port != sin2->sin_port)
1985                         return 0;
1986                 break;
1987         }
1988         case AF_INET6: {
1989                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1990                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1991                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1992                         return 0;
1993                 if (sin1->sin6_port != sin2->sin6_port)
1994                         return 0;
1995                 break;
1996         }
1997         default:
1998                 return 0;
1999         }
2000
2001         return 1;
2002 }
2003
2004 static int nfs_compare_super(struct super_block *sb, void *data)
2005 {
2006         struct nfs_sb_mountdata *sb_mntdata = data;
2007         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2008         int mntflags = sb_mntdata->mntflags;
2009
2010         if (!nfs_compare_super_address(old, server))
2011                 return 0;
2012         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2013         if (old->flags & NFS_MOUNT_UNSHARED)
2014                 return 0;
2015         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2016                 return 0;
2017         return nfs_compare_mount_options(sb, server, mntflags);
2018 }
2019
2020 static int nfs_bdi_register(struct nfs_server *server)
2021 {
2022         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2023 }
2024
2025 static int nfs_get_sb(struct file_system_type *fs_type,
2026         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2027 {
2028         struct nfs_server *server = NULL;
2029         struct super_block *s;
2030         struct nfs_parsed_mount_data *data;
2031         struct nfs_fh *mntfh;
2032         struct dentry *mntroot;
2033         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2034         struct nfs_sb_mountdata sb_mntdata = {
2035                 .mntflags = flags,
2036         };
2037         int error = -ENOMEM;
2038
2039         data = kzalloc(sizeof(*data), GFP_KERNEL);
2040         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2041         if (data == NULL || mntfh == NULL)
2042                 goto out_free_fh;
2043
2044         security_init_mnt_opts(&data->lsm_opts);
2045
2046         /* Validate the mount data */
2047         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2048         if (error < 0)
2049                 goto out;
2050
2051         /* Get a volume representation */
2052         server = nfs_create_server(data, mntfh);
2053         if (IS_ERR(server)) {
2054                 error = PTR_ERR(server);
2055                 goto out;
2056         }
2057         sb_mntdata.server = server;
2058
2059         if (server->flags & NFS_MOUNT_UNSHARED)
2060                 compare_super = NULL;
2061
2062         /* Get a superblock - note that we may end up sharing one that already exists */
2063         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2064         if (IS_ERR(s)) {
2065                 error = PTR_ERR(s);
2066                 goto out_err_nosb;
2067         }
2068
2069         if (s->s_fs_info != server) {
2070                 nfs_free_server(server);
2071                 server = NULL;
2072         } else {
2073                 error = nfs_bdi_register(server);
2074                 if (error)
2075                         goto error_splat_super;
2076         }
2077
2078         if (!s->s_root) {
2079                 /* initial superblock/root creation */
2080                 nfs_fill_super(s, data);
2081                 nfs_fscache_get_super_cookie(s, data);
2082         }
2083
2084         mntroot = nfs_get_root(s, mntfh);
2085         if (IS_ERR(mntroot)) {
2086                 error = PTR_ERR(mntroot);
2087                 goto error_splat_super;
2088         }
2089
2090         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2091         if (error)
2092                 goto error_splat_root;
2093
2094         s->s_flags |= MS_ACTIVE;
2095         mnt->mnt_sb = s;
2096         mnt->mnt_root = mntroot;
2097         error = 0;
2098
2099 out:
2100         kfree(data->nfs_server.hostname);
2101         kfree(data->mount_server.hostname);
2102         kfree(data->fscache_uniq);
2103         security_free_mnt_opts(&data->lsm_opts);
2104 out_free_fh:
2105         kfree(mntfh);
2106         kfree(data);
2107         return error;
2108
2109 out_err_nosb:
2110         nfs_free_server(server);
2111         goto out;
2112
2113 error_splat_root:
2114         dput(mntroot);
2115 error_splat_super:
2116         deactivate_locked_super(s);
2117         goto out;
2118 }
2119
2120 /*
2121  * Destroy an NFS2/3 superblock
2122  */
2123 static void nfs_kill_super(struct super_block *s)
2124 {
2125         struct nfs_server *server = NFS_SB(s);
2126
2127         bdi_unregister(&server->backing_dev_info);
2128         kill_anon_super(s);
2129         nfs_fscache_release_super_cookie(s);
2130         nfs_free_server(server);
2131 }
2132
2133 /*
2134  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2135  */
2136 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2137                            const char *dev_name, void *raw_data,
2138                            struct vfsmount *mnt)
2139 {
2140         struct nfs_clone_mount *data = raw_data;
2141         struct super_block *s;
2142         struct nfs_server *server;
2143         struct dentry *mntroot;
2144         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2145         struct nfs_sb_mountdata sb_mntdata = {
2146                 .mntflags = flags,
2147         };
2148         int error;
2149
2150         dprintk("--> nfs_xdev_get_sb()\n");
2151
2152         /* create a new volume representation */
2153         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2154         if (IS_ERR(server)) {
2155                 error = PTR_ERR(server);
2156                 goto out_err_noserver;
2157         }
2158         sb_mntdata.server = server;
2159
2160         if (server->flags & NFS_MOUNT_UNSHARED)
2161                 compare_super = NULL;
2162
2163         /* Get a superblock - note that we may end up sharing one that already exists */
2164         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2165         if (IS_ERR(s)) {
2166                 error = PTR_ERR(s);
2167                 goto out_err_nosb;
2168         }
2169
2170         if (s->s_fs_info != server) {
2171                 nfs_free_server(server);
2172                 server = NULL;
2173         } else {
2174                 error = nfs_bdi_register(server);
2175                 if (error)
2176                         goto error_splat_super;
2177         }
2178
2179         if (!s->s_root) {
2180                 /* initial superblock/root creation */
2181                 nfs_clone_super(s, data->sb);
2182         }
2183
2184         mntroot = nfs_get_root(s, data->fh);
2185         if (IS_ERR(mntroot)) {
2186                 error = PTR_ERR(mntroot);
2187                 goto error_splat_super;
2188         }
2189         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2190                 dput(mntroot);
2191                 error = -ESTALE;
2192                 goto error_splat_super;
2193         }
2194
2195         s->s_flags |= MS_ACTIVE;
2196         mnt->mnt_sb = s;
2197         mnt->mnt_root = mntroot;
2198
2199         /* clone any lsm security options from the parent to the new sb */
2200         security_sb_clone_mnt_opts(data->sb, s);
2201
2202         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2203         return 0;
2204
2205 out_err_nosb:
2206         nfs_free_server(server);
2207 out_err_noserver:
2208         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2209         return error;
2210
2211 error_splat_super:
2212         deactivate_locked_super(s);
2213         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2214         return error;
2215 }
2216
2217 #ifdef CONFIG_NFS_V4
2218
2219 /*
2220  * Finish setting up a cloned NFS4 superblock
2221  */
2222 static void nfs4_clone_super(struct super_block *sb,
2223                             const struct super_block *old_sb)
2224 {
2225         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2226         sb->s_blocksize = old_sb->s_blocksize;
2227         sb->s_maxbytes = old_sb->s_maxbytes;
2228         sb->s_time_gran = 1;
2229         sb->s_op = old_sb->s_op;
2230         nfs_initialise_sb(sb);
2231 }
2232
2233 /*
2234  * Set up an NFS4 superblock
2235  */
2236 static void nfs4_fill_super(struct super_block *sb)
2237 {
2238         sb->s_time_gran = 1;
2239         sb->s_op = &nfs4_sops;
2240         nfs_initialise_sb(sb);
2241 }
2242
2243 /*
2244  * Validate NFSv4 mount options
2245  */
2246 static int nfs4_validate_mount_data(void *options,
2247                                     struct nfs_parsed_mount_data *args,
2248                                     const char *dev_name)
2249 {
2250         struct sockaddr_in *ap;
2251         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2252         char *c;
2253
2254         if (data == NULL)
2255                 goto out_no_data;
2256
2257         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2258         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2259         args->acregmin          = NFS_DEF_ACREGMIN;
2260         args->acregmax          = NFS_DEF_ACREGMAX;
2261         args->acdirmin          = NFS_DEF_ACDIRMIN;
2262         args->acdirmax          = NFS_DEF_ACDIRMAX;
2263         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2264         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2265         args->auth_flavor_len   = 0;
2266
2267         switch (data->version) {
2268         case 1:
2269                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2270                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2271                         goto out_no_address;
2272                 if (data->host_addrlen == 0)
2273                         goto out_no_address;
2274                 args->nfs_server.addrlen = data->host_addrlen;
2275                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2276                         return -EFAULT;
2277                 if (!nfs_verify_server_address((struct sockaddr *)
2278                                                 &args->nfs_server.address))
2279                         goto out_no_address;
2280
2281                 if (data->auth_flavourlen) {
2282                         if (data->auth_flavourlen > 1)
2283                                 goto out_inval_auth;
2284                         if (copy_from_user(&args->auth_flavors[0],
2285                                            data->auth_flavours,
2286                                            sizeof(args->auth_flavors[0])))
2287                                 return -EFAULT;
2288                 }
2289
2290                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2291                 if (IS_ERR(c))
2292                         return PTR_ERR(c);
2293                 args->nfs_server.hostname = c;
2294
2295                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2296                 if (IS_ERR(c))
2297                         return PTR_ERR(c);
2298                 args->nfs_server.export_path = c;
2299                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2300
2301                 c = strndup_user(data->client_addr.data, 16);
2302                 if (IS_ERR(c))
2303                         return PTR_ERR(c);
2304                 args->client_address = c;
2305
2306                 /*
2307                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2308                  * can deal with.
2309                  */
2310
2311                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2312                 args->rsize     = data->rsize;
2313                 args->wsize     = data->wsize;
2314                 args->timeo     = data->timeo;
2315                 args->retrans   = data->retrans;
2316                 args->acregmin  = data->acregmin;
2317                 args->acregmax  = data->acregmax;
2318                 args->acdirmin  = data->acdirmin;
2319                 args->acdirmax  = data->acdirmax;
2320                 args->nfs_server.protocol = data->proto;
2321                 nfs_validate_transport_protocol(args);
2322
2323                 break;
2324         default: {
2325                 int status;
2326
2327                 if (nfs_parse_mount_options((char *)options, args) == 0)
2328                         return -EINVAL;
2329
2330                 if (!nfs_verify_server_address((struct sockaddr *)
2331                                                 &args->nfs_server.address))
2332                         return -EINVAL;
2333
2334                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
2335                                 args->nfs_server.port);
2336
2337                 nfs_validate_transport_protocol(args);
2338
2339                 if (args->auth_flavor_len > 1)
2340                         goto out_inval_auth;
2341
2342                 if (args->client_address == NULL)
2343                         goto out_no_client_address;
2344
2345                 status = nfs_parse_devname(dev_name,
2346                                            &args->nfs_server.hostname,
2347                                            NFS4_MAXNAMLEN,
2348                                            &args->nfs_server.export_path,
2349                                            NFS4_MAXPATHLEN);
2350                 if (status < 0)
2351                         return status;
2352
2353                 break;
2354                 }
2355         }
2356
2357         return 0;
2358
2359 out_no_data:
2360         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2361         return -EINVAL;
2362
2363 out_inval_auth:
2364         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2365                  data->auth_flavourlen);
2366         return -EINVAL;
2367
2368 out_no_address:
2369         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2370         return -EINVAL;
2371
2372 out_no_client_address:
2373         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2374         return -EINVAL;
2375 }
2376
2377 /*
2378  * Get the superblock for an NFS4 mountpoint
2379  */
2380 static int nfs4_get_sb(struct file_system_type *fs_type,
2381         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2382 {
2383         struct nfs_parsed_mount_data *data;
2384         struct super_block *s;
2385         struct nfs_server *server;
2386         struct nfs_fh *mntfh;
2387         struct dentry *mntroot;
2388         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2389         struct nfs_sb_mountdata sb_mntdata = {
2390                 .mntflags = flags,
2391         };
2392         int error = -ENOMEM;
2393
2394         data = kzalloc(sizeof(*data), GFP_KERNEL);
2395         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2396         if (data == NULL || mntfh == NULL)
2397                 goto out_free_fh;
2398
2399         security_init_mnt_opts(&data->lsm_opts);
2400
2401         /* Validate the mount data */
2402         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2403         if (error < 0)
2404                 goto out;
2405
2406         /* Get a volume representation */
2407         server = nfs4_create_server(data, mntfh);
2408         if (IS_ERR(server)) {
2409                 error = PTR_ERR(server);
2410                 goto out;
2411         }
2412         sb_mntdata.server = server;
2413
2414         if (server->flags & NFS4_MOUNT_UNSHARED)
2415                 compare_super = NULL;
2416
2417         /* Get a superblock - note that we may end up sharing one that already exists */
2418         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2419         if (IS_ERR(s)) {
2420                 error = PTR_ERR(s);
2421                 goto out_free;
2422         }
2423
2424         if (s->s_fs_info != server) {
2425                 nfs_free_server(server);
2426                 server = NULL;
2427         } else {
2428                 error = nfs_bdi_register(server);
2429                 if (error)
2430                         goto error_splat_super;
2431         }
2432
2433         if (!s->s_root) {
2434                 /* initial superblock/root creation */
2435                 nfs4_fill_super(s);
2436                 nfs_fscache_get_super_cookie(s, data);
2437         }
2438
2439         mntroot = nfs4_get_root(s, mntfh);
2440         if (IS_ERR(mntroot)) {
2441                 error = PTR_ERR(mntroot);
2442                 goto error_splat_super;
2443         }
2444
2445         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2446         if (error)
2447                 goto error_splat_root;
2448
2449         s->s_flags |= MS_ACTIVE;
2450         mnt->mnt_sb = s;
2451         mnt->mnt_root = mntroot;
2452         error = 0;
2453
2454 out:
2455         kfree(data->client_address);
2456         kfree(data->nfs_server.export_path);
2457         kfree(data->nfs_server.hostname);
2458         kfree(data->fscache_uniq);
2459         security_free_mnt_opts(&data->lsm_opts);
2460 out_free_fh:
2461         kfree(mntfh);
2462         kfree(data);
2463         return error;
2464
2465 out_free:
2466         nfs_free_server(server);
2467         goto out;
2468
2469 error_splat_root:
2470         dput(mntroot);
2471 error_splat_super:
2472         deactivate_locked_super(s);
2473         goto out;
2474 }
2475
2476 static void nfs4_kill_super(struct super_block *sb)
2477 {
2478         struct nfs_server *server = NFS_SB(sb);
2479
2480         nfs_super_return_all_delegations(sb);
2481         kill_anon_super(sb);
2482
2483         nfs4_renewd_prepare_shutdown(server);
2484         nfs_fscache_release_super_cookie(sb);
2485         nfs_free_server(server);
2486 }
2487
2488 /*
2489  * Clone an NFS4 server record on xdev traversal (FSID-change)
2490  */
2491 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2492                             const char *dev_name, void *raw_data,
2493                             struct vfsmount *mnt)
2494 {
2495         struct nfs_clone_mount *data = raw_data;
2496         struct super_block *s;
2497         struct nfs_server *server;
2498         struct dentry *mntroot;
2499         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2500         struct nfs_sb_mountdata sb_mntdata = {
2501                 .mntflags = flags,
2502         };
2503         int error;
2504
2505         dprintk("--> nfs4_xdev_get_sb()\n");
2506
2507         /* create a new volume representation */
2508         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2509         if (IS_ERR(server)) {
2510                 error = PTR_ERR(server);
2511                 goto out_err_noserver;
2512         }
2513         sb_mntdata.server = server;
2514
2515         if (server->flags & NFS4_MOUNT_UNSHARED)
2516                 compare_super = NULL;
2517
2518         /* Get a superblock - note that we may end up sharing one that already exists */
2519         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2520         if (IS_ERR(s)) {
2521                 error = PTR_ERR(s);
2522                 goto out_err_nosb;
2523         }
2524
2525         if (s->s_fs_info != server) {
2526                 nfs_free_server(server);
2527                 server = NULL;
2528         } else {
2529                 error = nfs_bdi_register(server);
2530                 if (error)
2531                         goto error_splat_super;
2532         }
2533
2534         if (!s->s_root) {
2535                 /* initial superblock/root creation */
2536                 nfs4_clone_super(s, data->sb);
2537         }
2538
2539         mntroot = nfs4_get_root(s, data->fh);
2540         if (IS_ERR(mntroot)) {
2541                 error = PTR_ERR(mntroot);
2542                 goto error_splat_super;
2543         }
2544         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2545                 dput(mntroot);
2546                 error = -ESTALE;
2547                 goto error_splat_super;
2548         }
2549
2550         s->s_flags |= MS_ACTIVE;
2551         mnt->mnt_sb = s;
2552         mnt->mnt_root = mntroot;
2553
2554         security_sb_clone_mnt_opts(data->sb, s);
2555
2556         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2557         return 0;
2558
2559 out_err_nosb:
2560         nfs_free_server(server);
2561 out_err_noserver:
2562         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2563         return error;
2564
2565 error_splat_super:
2566         deactivate_locked_super(s);
2567         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2568         return error;
2569 }
2570
2571 /*
2572  * Create an NFS4 server record on referral traversal
2573  */
2574 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2575                                 const char *dev_name, void *raw_data,
2576                                 struct vfsmount *mnt)
2577 {
2578         struct nfs_clone_mount *data = raw_data;
2579         struct super_block *s;
2580         struct nfs_server *server;
2581         struct dentry *mntroot;
2582         struct nfs_fh mntfh;
2583         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2584         struct nfs_sb_mountdata sb_mntdata = {
2585                 .mntflags = flags,
2586         };
2587         int error;
2588
2589         dprintk("--> nfs4_referral_get_sb()\n");
2590
2591         /* create a new volume representation */
2592         server = nfs4_create_referral_server(data, &mntfh);
2593         if (IS_ERR(server)) {
2594                 error = PTR_ERR(server);
2595                 goto out_err_noserver;
2596         }
2597         sb_mntdata.server = server;
2598
2599         if (server->flags & NFS4_MOUNT_UNSHARED)
2600                 compare_super = NULL;
2601
2602         /* Get a superblock - note that we may end up sharing one that already exists */
2603         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2604         if (IS_ERR(s)) {
2605                 error = PTR_ERR(s);
2606                 goto out_err_nosb;
2607         }
2608
2609         if (s->s_fs_info != server) {
2610                 nfs_free_server(server);
2611                 server = NULL;
2612         } else {
2613                 error = nfs_bdi_register(server);
2614                 if (error)
2615                         goto error_splat_super;
2616         }
2617
2618         if (!s->s_root) {
2619                 /* initial superblock/root creation */
2620                 nfs4_fill_super(s);
2621         }
2622
2623         mntroot = nfs4_get_root(s, &mntfh);
2624         if (IS_ERR(mntroot)) {
2625                 error = PTR_ERR(mntroot);
2626                 goto error_splat_super;
2627         }
2628         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2629                 dput(mntroot);
2630                 error = -ESTALE;
2631                 goto error_splat_super;
2632         }
2633
2634         s->s_flags |= MS_ACTIVE;
2635         mnt->mnt_sb = s;
2636         mnt->mnt_root = mntroot;
2637
2638         security_sb_clone_mnt_opts(data->sb, s);
2639
2640         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2641         return 0;
2642
2643 out_err_nosb:
2644         nfs_free_server(server);
2645 out_err_noserver:
2646         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2647         return error;
2648
2649 error_splat_super:
2650         deactivate_locked_super(s);
2651         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2652         return error;
2653 }
2654
2655 #endif /* CONFIG_NFS_V4 */