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_POSIX, ",posix", "" },
 518                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 519                 { NFS_MOUNT_NOAC, ",noac", "" },
 520                 { NFS_MOUNT_NONLM, ",nolock", "" },
 521                 { NFS_MOUNT_NOACL, ",noacl", "" },
 522                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 523                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 524                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 525                 { 0, NULL, NULL }
 526         };
 527         const struct proc_nfs_info *nfs_infop;
 528         struct nfs_client *clp = nfss->nfs_client;
 529         u32 version = clp->rpc_ops->version;
 530
 531         seq_printf(m, ",vers=%u", version);
 532         seq_printf(m, ",rsize=%u", nfss->rsize);
 533         seq_printf(m, ",wsize=%u", nfss->wsize);
 534         if (nfss->bsize != 0)
 535                 seq_printf(m, ",bsize=%u", nfss->bsize);
 536         seq_printf(m, ",namlen=%u", nfss->namelen);
 537         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 538                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 539         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 540                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 541         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 542                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 543         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 544                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 545         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 546                 if (nfss->flags & nfs_infop->flag)
 547                         seq_puts(m, nfs_infop->str);
 548                 else
 549                         seq_puts(m, nfs_infop->nostr);
 550         }
 551         seq_printf(m, ",proto=%s",
 552                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 553         if (version == 4) {
 554                 if (nfss->port != NFS_PORT)
 555                         seq_printf(m, ",port=%u", nfss->port);
 556         } else
 557                 if (nfss->port)
 558                         seq_printf(m, ",port=%u", nfss->port);
 559
 560         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 561         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 562         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 563
 564         if (version != 4)
 565                 nfs_show_mountd_options(m, nfss, showdefaults);
 566
 567 #ifdef CONFIG_NFS_V4
 568         if (clp->rpc_ops->version == 4)
 569                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 570 #endif
 571         if (nfss->options & NFS_OPTION_FSCACHE)
 572                 seq_printf(m, ",fsc");
 573 }
 574
 575 /*
 576  * Describe the mount options on this VFS mountpoint
 577  */
 578 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 579 {
 580         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 581
 582         nfs_show_mount_options(m, nfss, 0);
 583
 584         seq_printf(m, ",addr=%s",
 585                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 586                                                         RPC_DISPLAY_ADDR));
 587
 588         return 0;
 589 }
 590
 591 /*
 592  * Present statistical information for this VFS mountpoint
 593  */
 594 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 595 {
 596         int i, cpu;
 597         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 598         struct rpc_auth *auth = nfss->client->cl_auth;
 599         struct nfs_iostats totals = { };
 600
 601         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 602
 603         /*
 604          * Display all mount option settings
 605          */
 606         seq_printf(m, "\n\topts:\t");
 607         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 608         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 609         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 610         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 611         nfs_show_mount_options(m, nfss, 1);
 612
 613         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 614
 615         seq_printf(m, "\n\tcaps:\t");
 616         seq_printf(m, "caps=0x%x", nfss->caps);
 617         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 618         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 619         seq_printf(m, ",bsize=%u", nfss->bsize);
 620         seq_printf(m, ",namlen=%u", nfss->namelen);
 621
 622 #ifdef CONFIG_NFS_V4
 623         if (nfss->nfs_client->rpc_ops->version == 4) {
 624                 seq_printf(m, "\n\tnfsv4:\t");
 625                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 626                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 627                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 628         }
 629 #endif
 630
 631         /*
 632          * Display security flavor in effect for this mount
 633          */
 634         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 635         if (auth->au_flavor)
 636                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 637
 638         /*
 639          * Display superblock I/O counters
 640          */
 641         for_each_possible_cpu(cpu) {
 642                 struct nfs_iostats *stats;
 643
 644                 preempt_disable();
 645                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 646
 647                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 648                         totals.events[i] += stats->events[i];
 649                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 650                         totals.bytes[i] += stats->bytes[i];
 651 #ifdef CONFIG_NFS_FSCACHE
 652                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 653                         totals.fscache[i] += stats->fscache[i];
 654 #endif
 655
 656                 preempt_enable();
 657         }
 658
 659         seq_printf(m, "\n\tevents:\t");
 660         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 661                 seq_printf(m, "%lu ", totals.events[i]);
 662         seq_printf(m, "\n\tbytes:\t");
 663         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 664                 seq_printf(m, "%Lu ", totals.bytes[i]);
 665 #ifdef CONFIG_NFS_FSCACHE
 666         if (nfss->options & NFS_OPTION_FSCACHE) {
 667                 seq_printf(m, "\n\tfsc:\t");
 668                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 669                         seq_printf(m, "%Lu ", totals.bytes[i]);
 670         }
 671 #endif
 672         seq_printf(m, "\n");
 673
 674         rpc_print_iostats(m, nfss->client);
 675
 676         return 0;
 677 }
 678
 679 /*
 680  * Begin unmount by attempting to remove all automounted mountpoints we added
 681  * in response to xdev traversals and referrals
 682  */
 683 static void nfs_umount_begin(struct super_block *sb)
 684 {
 685         struct nfs_server *server;
 686         struct rpc_clnt *rpc;
 687
 688         lock_kernel();
 689
 690         server = NFS_SB(sb);
 691         /* -EIO all pending I/O */
 692         rpc = server->client_acl;
 693         if (!IS_ERR(rpc))
 694                 rpc_killall_tasks(rpc);
 695         rpc = server->client;
 696         if (!IS_ERR(rpc))
 697                 rpc_killall_tasks(rpc);
 698
 699         unlock_kernel();
 700 }
 701
 702 /*
 703  * Sanity-check a server address provided by the mount command.
 704  *
 705  * Address family must be initialized, and address must not be
 706  * the ANY address for that family.
 707  */
 708 static int nfs_verify_server_address(struct sockaddr *addr)
 709 {
 710         switch (addr->sa_family) {
 711         case AF_INET: {
 712                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 713                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 714         }
 715         case AF_INET6: {
 716                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 717                 return !ipv6_addr_any(sa);
 718         }
 719         }
 720
 721         return 0;
 722 }
 723
 724 static void nfs_parse_ipv4_address(char *string, size_t str_len,
 725                                    struct sockaddr *sap, size_t *addr_len)
 726 {
 727         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 728         u8 *addr = (u8 *)&sin->sin_addr.s_addr;
 729
 730         if (str_len <= INET_ADDRSTRLEN) {
 731                 dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
 732                                 (int)str_len, string);
 733
 734                 sin->sin_family = AF_INET;
 735                 *addr_len = sizeof(*sin);
 736                 if (in4_pton(string, str_len, addr, '\0', NULL))
 737                         return;
 738         }
 739
 740         sap->sa_family = AF_UNSPEC;
 741         *addr_len = 0;
 742 }
 743
 744 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 745 static int nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
 746                                    const char *delim,
 747                                    struct sockaddr_in6 *sin6)
 748 {
 749         char *p;
 750         size_t len;
 751
 752         if ((string + str_len) == delim)
 753                 return 1;
 754
 755         if (*delim != IPV6_SCOPE_DELIMITER)
 756                 return 0;
 757
 758         if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
 759                 return 0;
 760
 761         len = (string + str_len) - delim - 1;
 762         p = kstrndup(delim + 1, len, GFP_KERNEL);
 763         if (p) {
 764                 unsigned long scope_id = 0;
 765                 struct net_device *dev;
 766
 767                 dev = dev_get_by_name(&init_net, p);
 768                 if (dev != NULL) {
 769                         scope_id = dev->ifindex;
 770                         dev_put(dev);
 771                 } else {
 772                         if (strict_strtoul(p, 10, &scope_id) == 0) {
 773                                 kfree(p);
 774                                 return 0;
 775                         }
 776                 }
 777
 778                 kfree(p);
 779
 780                 sin6->sin6_scope_id = scope_id;
 781                 dfprintk(MOUNT, "NFS: IPv6 scope ID = %lu\n", scope_id);
 782                 return 1;
 783         }
 784
 785         return 0;
 786 }
 787
 788 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 789                                    struct sockaddr *sap, size_t *addr_len)
 790 {
 791         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 792         u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
 793         const char *delim;
 794
 795         if (str_len <= INET6_ADDRSTRLEN) {
 796                 dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
 797                                 (int)str_len, string);
 798
 799                 sin6->sin6_family = AF_INET6;
 800                 *addr_len = sizeof(*sin6);
 801                 if (in6_pton(string, str_len, addr,
 802                                         IPV6_SCOPE_DELIMITER, &delim) != 0) {
 803                         if (nfs_parse_ipv6_scope_id(string, str_len,
 804                                                         delim, sin6) != 0)
 805                                 return;
 806                 }
 807         }
 808
 809         sap->sa_family = AF_UNSPEC;
 810         *addr_len = 0;
 811 }
 812 #else
 813 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 814                                    struct sockaddr *sap, size_t *addr_len)
 815 {
 816         sap->sa_family = AF_UNSPEC;
 817         *addr_len = 0;
 818 }
 819 #endif
 820
 821 /*
 822  * Construct a sockaddr based on the contents of a string that contains
 823  * an IP address in presentation format.
 824  *
 825  * If there is a problem constructing the new sockaddr, set the address
 826  * family to AF_UNSPEC.
 827  */
 828 void nfs_parse_ip_address(char *string, size_t str_len,
 829                                  struct sockaddr *sap, size_t *addr_len)
 830 {
 831         unsigned int i, colons;
 832
 833         colons = 0;
 834         for (i = 0; i < str_len; i++)
 835                 if (string[i] == ':')
 836                         colons++;
 837
 838         if (colons >= 2)
 839                 nfs_parse_ipv6_address(string, str_len, sap, addr_len);
 840         else
 841                 nfs_parse_ipv4_address(string, str_len, sap, addr_len);
 842 }
 843
 844 /*
 845  * Sanity check the NFS transport protocol.
 846  *
 847  */
 848 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 849 {
 850         switch (mnt->nfs_server.protocol) {
 851         case XPRT_TRANSPORT_UDP:
 852         case XPRT_TRANSPORT_TCP:
 853         case XPRT_TRANSPORT_RDMA:
 854                 break;
 855         default:
 856                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 857         }
 858 }
 859
 860 /*
 861  * For text based NFSv2/v3 mounts, the mount protocol transport default
 862  * settings should depend upon the specified NFS transport.
 863  */
 864 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 865 {
 866         nfs_validate_transport_protocol(mnt);
 867
 868         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 869             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 870                         return;
 871         switch (mnt->nfs_server.protocol) {
 872         case XPRT_TRANSPORT_UDP:
 873                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 874                 break;
 875         case XPRT_TRANSPORT_TCP:
 876         case XPRT_TRANSPORT_RDMA:
 877                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 878         }
 879 }
 880
 881 /*
 882  * Parse the value of the 'sec=' option.
 883  *
 884  * The flavor_len setting is for v4 mounts.
 885  */
 886 static int nfs_parse_security_flavors(char *value,
 887                                       struct nfs_parsed_mount_data *mnt)
 888 {
 889         substring_t args[MAX_OPT_ARGS];
 890
 891         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 892
 893         switch (match_token(value, nfs_secflavor_tokens, args)) {
 894         case Opt_sec_none:
 895                 mnt->auth_flavor_len = 0;
 896                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 897                 break;
 898         case Opt_sec_sys:
 899                 mnt->auth_flavor_len = 0;
 900                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 901                 break;
 902         case Opt_sec_krb5:
 903                 mnt->auth_flavor_len = 1;
 904                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 905                 break;
 906         case Opt_sec_krb5i:
 907                 mnt->auth_flavor_len = 1;
 908                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 909                 break;
 910         case Opt_sec_krb5p:
 911                 mnt->auth_flavor_len = 1;
 912                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 913                 break;
 914         case Opt_sec_lkey:
 915                 mnt->auth_flavor_len = 1;
 916                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 917                 break;
 918         case Opt_sec_lkeyi:
 919                 mnt->auth_flavor_len = 1;
 920                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 921                 break;
 922         case Opt_sec_lkeyp:
 923                 mnt->auth_flavor_len = 1;
 924                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 925                 break;
 926         case Opt_sec_spkm:
 927                 mnt->auth_flavor_len = 1;
 928                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 929                 break;
 930         case Opt_sec_spkmi:
 931                 mnt->auth_flavor_len = 1;
 932                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 933                 break;
 934         case Opt_sec_spkmp:
 935                 mnt->auth_flavor_len = 1;
 936                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 937                 break;
 938         default:
 939                 return 0;
 940         }
 941
 942         return 1;
 943 }
 944
 945 /*
 946  * Error-check and convert a string of mount options from user space into
 947  * a data structure.  The whole mount string is processed; bad options are
 948  * skipped as they are encountered.  If there were no errors, return 1;
 949  * otherwise return 0 (zero).
 950  */
 951 static int nfs_parse_mount_options(char *raw,
 952                                    struct nfs_parsed_mount_data *mnt)
 953 {
 954         char *p, *string, *secdata;
 955         int rc, sloppy = 0, invalid_option = 0;
 956
 957         if (!raw) {
 958                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 959                 return 1;
 960         }
 961         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 962
 963         secdata = alloc_secdata();
 964         if (!secdata)
 965                 goto out_nomem;
 966
 967         rc = security_sb_copy_data(raw, secdata);
 968         if (rc)
 969                 goto out_security_failure;
 970
 971         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 972         if (rc)
 973                 goto out_security_failure;
 974
 975         free_secdata(secdata);
 976
 977         while ((p = strsep(&raw, ",")) != NULL) {
 978                 substring_t args[MAX_OPT_ARGS];
 979                 int option, token;
 980
 981                 if (!*p)
 982                         continue;
 983
 984                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 985
 986                 token = match_token(p, nfs_mount_option_tokens, args);
 987                 switch (token) {
 988
 989                 /*
 990                  * boolean options:  foo/nofoo
 991                  */
 992                 case Opt_soft:
 993                         mnt->flags |= NFS_MOUNT_SOFT;
 994                         break;
 995                 case Opt_hard:
 996                         mnt->flags &= ~NFS_MOUNT_SOFT;
 997                         break;
 998                 case Opt_posix:
 999                         mnt->flags |= NFS_MOUNT_POSIX;
1000                         break;
1001                 case Opt_noposix:
1002                         mnt->flags &= ~NFS_MOUNT_POSIX;
1003                         break;
1004                 case Opt_cto:
1005                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1006                         break;
1007                 case Opt_nocto:
1008                         mnt->flags |= NFS_MOUNT_NOCTO;
1009                         break;
1010                 case Opt_ac:
1011                         mnt->flags &= ~NFS_MOUNT_NOAC;
1012                         break;
1013                 case Opt_noac:
1014                         mnt->flags |= NFS_MOUNT_NOAC;
1015                         break;
1016                 case Opt_lock:
1017                         mnt->flags &= ~NFS_MOUNT_NONLM;
1018                         break;
1019                 case Opt_nolock:
1020                         mnt->flags |= NFS_MOUNT_NONLM;
1021                         break;
1022                 case Opt_v2:
1023                         mnt->flags &= ~NFS_MOUNT_VER3;
1024                         break;
1025                 case Opt_v3:
1026                         mnt->flags |= NFS_MOUNT_VER3;
1027                         break;
1028                 case Opt_udp:
1029                         mnt->flags &= ~NFS_MOUNT_TCP;
1030                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1031                         break;
1032                 case Opt_tcp:
1033                         mnt->flags |= NFS_MOUNT_TCP;
1034                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1035                         break;
1036                 case Opt_rdma:
1037                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1038                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1039                         xprt_load_transport(p);
1040                         break;
1041                 case Opt_acl:
1042                         mnt->flags &= ~NFS_MOUNT_NOACL;
1043                         break;
1044                 case Opt_noacl:
1045                         mnt->flags |= NFS_MOUNT_NOACL;
1046                         break;
1047                 case Opt_rdirplus:
1048                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1049                         break;
1050                 case Opt_nordirplus:
1051                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1052                         break;
1053                 case Opt_sharecache:
1054                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1055                         break;
1056                 case Opt_nosharecache:
1057                         mnt->flags |= NFS_MOUNT_UNSHARED;
1058                         break;
1059                 case Opt_resvport:
1060                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1061                         break;
1062                 case Opt_noresvport:
1063                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1064                         break;
1065                 case Opt_fscache:
1066                         mnt->options |= NFS_OPTION_FSCACHE;
1067                         kfree(mnt->fscache_uniq);
1068                         mnt->fscache_uniq = NULL;
1069                         break;
1070                 case Opt_nofscache:
1071                         mnt->options &= ~NFS_OPTION_FSCACHE;
1072                         kfree(mnt->fscache_uniq);
1073                         mnt->fscache_uniq = NULL;
1074                         break;
1075                 case Opt_fscache_uniq:
1076                         string = match_strdup(args);
1077                         if (!string)
1078                                 goto out_nomem;
1079                         kfree(mnt->fscache_uniq);
1080                         mnt->fscache_uniq = string;
1081                         mnt->options |= NFS_OPTION_FSCACHE;
1082                         break;
1083
1084                 /*
1085                  * options that take numeric values
1086                  */
1087                 case Opt_port:
1088                         if (match_int(args, &option) ||
1089                             option < 0 || option > USHORT_MAX)
1090                                 goto out_invalid_value;
1091                         mnt->nfs_server.port = option;
1092                         break;
1093                 case Opt_rsize:
1094                         if (match_int(args, &option) || option < 0)
1095                                 goto out_invalid_value;
1096                         mnt->rsize = option;
1097                         break;
1098                 case Opt_wsize:
1099                         if (match_int(args, &option) || option < 0)
1100                                 goto out_invalid_value;
1101                         mnt->wsize = option;
1102                         break;
1103                 case Opt_bsize:
1104                         if (match_int(args, &option) || option < 0)
1105                                 goto out_invalid_value;
1106                         mnt->bsize = option;
1107                         break;
1108                 case Opt_timeo:
1109                         if (match_int(args, &option) || option <= 0)
1110                                 goto out_invalid_value;
1111                         mnt->timeo = option;
1112                         break;
1113                 case Opt_retrans:
1114                         if (match_int(args, &option) || option <= 0)
1115                                 goto out_invalid_value;
1116                         mnt->retrans = option;
1117                         break;
1118                 case Opt_acregmin:
1119                         if (match_int(args, &option) || option < 0)
1120                                 goto out_invalid_value;
1121                         mnt->acregmin = option;
1122                         break;
1123                 case Opt_acregmax:
1124                         if (match_int(args, &option) || option < 0)
1125                                 goto out_invalid_value;
1126                         mnt->acregmax = option;
1127                         break;
1128                 case Opt_acdirmin:
1129                         if (match_int(args, &option) || option < 0)
1130                                 goto out_invalid_value;
1131                         mnt->acdirmin = option;
1132                         break;
1133                 case Opt_acdirmax:
1134                         if (match_int(args, &option) || option < 0)
1135                                 goto out_invalid_value;
1136                         mnt->acdirmax = option;
1137                         break;
1138                 case Opt_actimeo:
1139                         if (match_int(args, &option) || option < 0)
1140                                 goto out_invalid_value;
1141                         mnt->acregmin = mnt->acregmax =
1142                         mnt->acdirmin = mnt->acdirmax = option;
1143                         break;
1144                 case Opt_namelen:
1145                         if (match_int(args, &option) || option < 0)
1146                                 goto out_invalid_value;
1147                         mnt->namlen = option;
1148                         break;
1149                 case Opt_mountport:
1150                         if (match_int(args, &option) ||
1151                             option < 0 || option > USHORT_MAX)
1152                                 goto out_invalid_value;
1153                         mnt->mount_server.port = option;
1154                         break;
1155                 case Opt_mountvers:
1156                         if (match_int(args, &option) ||
1157                             option < NFS_MNT_VERSION ||
1158                             option > NFS_MNT3_VERSION)
1159                                 goto out_invalid_value;
1160                         mnt->mount_server.version = option;
1161                         break;
1162                 case Opt_nfsvers:
1163                         if (match_int(args, &option))
1164                                 goto out_invalid_value;
1165                         switch (option) {
1166                         case NFS2_VERSION:
1167                                 mnt->flags &= ~NFS_MOUNT_VER3;
1168                                 break;
1169                         case NFS3_VERSION:
1170                                 mnt->flags |= NFS_MOUNT_VER3;
1171                                 break;
1172                         default:
1173                                 goto out_invalid_value;
1174                         }
1175                         break;
1176
1177                 /*
1178                  * options that take text values
1179                  */
1180                 case Opt_sec:
1181                         string = match_strdup(args);
1182                         if (string == NULL)
1183                                 goto out_nomem;
1184                         rc = nfs_parse_security_flavors(string, mnt);
1185                         kfree(string);
1186                         if (!rc) {
1187                                 dfprintk(MOUNT, "NFS:   unrecognized "
1188                                                 "security flavor\n");
1189                                 return 0;
1190                         }
1191                         break;
1192                 case Opt_proto:
1193                         string = match_strdup(args);
1194                         if (string == NULL)
1195                                 goto out_nomem;
1196                         token = match_token(string,
1197                                             nfs_xprt_protocol_tokens, args);
1198
1199                         switch (token) {
1200                         case Opt_xprt_udp:
1201                                 mnt->flags &= ~NFS_MOUNT_TCP;
1202                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1203                                 kfree(string);
1204                                 break;
1205                         case Opt_xprt_tcp:
1206                                 mnt->flags |= NFS_MOUNT_TCP;
1207                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1208                                 kfree(string);
1209                                 break;
1210                         case Opt_xprt_rdma:
1211                                 /* vector side protocols to TCP */
1212                                 mnt->flags |= NFS_MOUNT_TCP;
1213                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1214                                 xprt_load_transport(string);
1215                                 kfree(string);
1216                                 break;
1217                         default:
1218                                 dfprintk(MOUNT, "NFS:   unrecognized "
1219                                                 "transport protocol\n");
1220                                 return 0;
1221                         }
1222                         break;
1223                 case Opt_mountproto:
1224                         string = match_strdup(args);
1225                         if (string == NULL)
1226                                 goto out_nomem;
1227                         token = match_token(string,
1228                                             nfs_xprt_protocol_tokens, args);
1229                         kfree(string);
1230
1231                         switch (token) {
1232                         case Opt_xprt_udp:
1233                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1234                                 break;
1235                         case Opt_xprt_tcp:
1236                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1237                                 break;
1238                         case Opt_xprt_rdma: /* not used for side protocols */
1239                         default:
1240                                 dfprintk(MOUNT, "NFS:   unrecognized "
1241                                                 "transport protocol\n");
1242                                 return 0;
1243                         }
1244                         break;
1245                 case Opt_addr:
1246                         string = match_strdup(args);
1247                         if (string == NULL)
1248                                 goto out_nomem;
1249                         nfs_parse_ip_address(string, strlen(string),
1250                                              (struct sockaddr *)
1251                                                 &mnt->nfs_server.address,
1252                                              &mnt->nfs_server.addrlen);
1253                         kfree(string);
1254                         break;
1255                 case Opt_clientaddr:
1256                         string = match_strdup(args);
1257                         if (string == NULL)
1258                                 goto out_nomem;
1259                         kfree(mnt->client_address);
1260                         mnt->client_address = string;
1261                         break;
1262                 case Opt_mounthost:
1263                         string = match_strdup(args);
1264                         if (string == NULL)
1265                                 goto out_nomem;
1266                         kfree(mnt->mount_server.hostname);
1267                         mnt->mount_server.hostname = string;
1268                         break;
1269                 case Opt_mountaddr:
1270                         string = match_strdup(args);
1271                         if (string == NULL)
1272                                 goto out_nomem;
1273                         nfs_parse_ip_address(string, strlen(string),
1274                                              (struct sockaddr *)
1275                                                 &mnt->mount_server.address,
1276                                              &mnt->mount_server.addrlen);
1277                         kfree(string);
1278                         break;
1279                 case Opt_lookupcache:
1280                         string = match_strdup(args);
1281                         if (string == NULL)
1282                                 goto out_nomem;
1283                         token = match_token(string,
1284                                         nfs_lookupcache_tokens, args);
1285                         kfree(string);
1286                         switch (token) {
1287                                 case Opt_lookupcache_all:
1288                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1289                                         break;
1290                                 case Opt_lookupcache_positive:
1291                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1292                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1293                                         break;
1294                                 case Opt_lookupcache_none:
1295                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1296                                         break;
1297                                 default:
1298                                         dfprintk(MOUNT, "NFS:   invalid "
1299                                                         "lookupcache argument\n");
1300                                         return 0;
1301                         };
1302                         break;
1303
1304                 /*
1305                  * Special options
1306                  */
1307                 case Opt_sloppy:
1308                         sloppy = 1;
1309                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1310                         break;
1311                 case Opt_userspace:
1312                 case Opt_deprecated:
1313                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1314                                         "'%s'\n", p);
1315                         break;
1316
1317                 default:
1318                         invalid_option = 1;
1319                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1320                                         "'%s'\n", p);
1321                 }
1322         }
1323
1324         if (!sloppy && invalid_option)
1325                 return 0;
1326
1327         return 1;
1328
1329 out_invalid_value:
1330         printk(KERN_INFO "NFS: bad mount option value specified: %s \n", p);
1331         return 0;
1332 out_nomem:
1333         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1334         return 0;
1335 out_security_failure:
1336         free_secdata(secdata);
1337         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1338         return 0;
1339 }
1340
1341 /*
1342  * Use the remote server's MOUNT service to request the NFS file handle
1343  * corresponding to the provided path.
1344  */
1345 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1346                          struct nfs_fh *root_fh)
1347 {
1348         unsigned int auth_flavor_len = 0;
1349         struct nfs_mount_request request = {
1350                 .sap            = (struct sockaddr *)
1351                                                 &args->mount_server.address,
1352                 .dirpath        = args->nfs_server.export_path,
1353                 .protocol       = args->mount_server.protocol,
1354                 .fh             = root_fh,
1355                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1356                 .auth_flav_len  = &auth_flavor_len,
1357         };
1358         int status;
1359
1360         if (args->mount_server.version == 0) {
1361                 if (args->flags & NFS_MOUNT_VER3)
1362                         args->mount_server.version = NFS_MNT3_VERSION;
1363                 else
1364                         args->mount_server.version = NFS_MNT_VERSION;
1365         }
1366         request.version = args->mount_server.version;
1367
1368         if (args->mount_server.hostname)
1369                 request.hostname = args->mount_server.hostname;
1370         else
1371                 request.hostname = args->nfs_server.hostname;
1372
1373         /*
1374          * Construct the mount server's address.
1375          */
1376         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1377                 memcpy(request.sap, &args->nfs_server.address,
1378                        args->nfs_server.addrlen);
1379                 args->mount_server.addrlen = args->nfs_server.addrlen;
1380         }
1381         request.salen = args->mount_server.addrlen;
1382
1383         /*
1384          * autobind will be used if mount_server.port == 0
1385          */
1386         nfs_set_port(request.sap, args->mount_server.port);
1387
1388         /*
1389          * Now ask the mount server to map our export path
1390          * to a file handle.
1391          */
1392         status = nfs_mount(&request);
1393         if (status == 0)
1394                 return 0;
1395
1396         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1397                         request.hostname, status);
1398         return status;
1399 }
1400
1401 static int nfs_parse_simple_hostname(const char *dev_name,
1402                                      char **hostname, size_t maxnamlen,
1403                                      char **export_path, size_t maxpathlen)
1404 {
1405         size_t len;
1406         char *colon, *comma;
1407
1408         colon = strchr(dev_name, ':');
1409         if (colon == NULL)
1410                 goto out_bad_devname;
1411
1412         len = colon - dev_name;
1413         if (len > maxnamlen)
1414                 goto out_hostname;
1415
1416         /* N.B. caller will free nfs_server.hostname in all cases */
1417         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1418         if (!*hostname)
1419                 goto out_nomem;
1420
1421         /* kill possible hostname list: not supported */
1422         comma = strchr(*hostname, ',');
1423         if (comma != NULL) {
1424                 if (comma == *hostname)
1425                         goto out_bad_devname;
1426                 *comma = '\0';
1427         }
1428
1429         colon++;
1430         len = strlen(colon);
1431         if (len > maxpathlen)
1432                 goto out_path;
1433         *export_path = kstrndup(colon, len, GFP_KERNEL);
1434         if (!*export_path)
1435                 goto out_nomem;
1436
1437         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1438         return 0;
1439
1440 out_bad_devname:
1441         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1442         return -EINVAL;
1443
1444 out_nomem:
1445         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1446         return -ENOMEM;
1447
1448 out_hostname:
1449         dfprintk(MOUNT, "NFS: server hostname too long\n");
1450         return -ENAMETOOLONG;
1451
1452 out_path:
1453         dfprintk(MOUNT, "NFS: export pathname too long\n");
1454         return -ENAMETOOLONG;
1455 }
1456
1457 /*
1458  * Hostname has square brackets around it because it contains one or
1459  * more colons.  We look for the first closing square bracket, and a
1460  * colon must follow it.
1461  */
1462 static int nfs_parse_protected_hostname(const char *dev_name,
1463                                         char **hostname, size_t maxnamlen,
1464                                         char **export_path, size_t maxpathlen)
1465 {
1466         size_t len;
1467         char *start, *end;
1468
1469         start = (char *)(dev_name + 1);
1470
1471         end = strchr(start, ']');
1472         if (end == NULL)
1473                 goto out_bad_devname;
1474         if (*(end + 1) != ':')
1475                 goto out_bad_devname;
1476
1477         len = end - start;
1478         if (len > maxnamlen)
1479                 goto out_hostname;
1480
1481         /* N.B. caller will free nfs_server.hostname in all cases */
1482         *hostname = kstrndup(start, len, GFP_KERNEL);
1483         if (*hostname == NULL)
1484                 goto out_nomem;
1485
1486         end += 2;
1487         len = strlen(end);
1488         if (len > maxpathlen)
1489                 goto out_path;
1490         *export_path = kstrndup(end, len, GFP_KERNEL);
1491         if (!*export_path)
1492                 goto out_nomem;
1493
1494         return 0;
1495
1496 out_bad_devname:
1497         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1498         return -EINVAL;
1499
1500 out_nomem:
1501         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1502         return -ENOMEM;
1503
1504 out_hostname:
1505         dfprintk(MOUNT, "NFS: server hostname too long\n");
1506         return -ENAMETOOLONG;
1507
1508 out_path:
1509         dfprintk(MOUNT, "NFS: export pathname too long\n");
1510         return -ENAMETOOLONG;
1511 }
1512
1513 /*
1514  * Split "dev_name" into "hostname:export_path".
1515  *
1516  * The leftmost colon demarks the split between the server's hostname
1517  * and the export path.  If the hostname starts with a left square
1518  * bracket, then it may contain colons.
1519  *
1520  * Note: caller frees hostname and export path, even on error.
1521  */
1522 static int nfs_parse_devname(const char *dev_name,
1523                              char **hostname, size_t maxnamlen,
1524                              char **export_path, size_t maxpathlen)
1525 {
1526         if (*dev_name == '[')
1527                 return nfs_parse_protected_hostname(dev_name,
1528                                                     hostname, maxnamlen,
1529                                                     export_path, maxpathlen);
1530
1531         return nfs_parse_simple_hostname(dev_name,
1532                                          hostname, maxnamlen,
1533                                          export_path, maxpathlen);
1534 }
1535
1536 /*
1537  * Validate the NFS2/NFS3 mount data
1538  * - fills in the mount root filehandle
1539  *
1540  * For option strings, user space handles the following behaviors:
1541  *
1542  * + DNS: mapping server host name to IP address ("addr=" option)
1543  *
1544  * + failure mode: how to behave if a mount request can't be handled
1545  *   immediately ("fg/bg" option)
1546  *
1547  * + retry: how often to retry a mount request ("retry=" option)
1548  *
1549  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1550  *   mountproto=tcp after mountproto=udp, and so on
1551  */
1552 static int nfs_validate_mount_data(void *options,
1553                                    struct nfs_parsed_mount_data *args,
1554                                    struct nfs_fh *mntfh,
1555                                    const char *dev_name)
1556 {
1557         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1558
1559         if (data == NULL)
1560                 goto out_no_data;
1561
1562         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1563         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1564         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1565         args->acregmin          = NFS_DEF_ACREGMIN;
1566         args->acregmax          = NFS_DEF_ACREGMAX;
1567         args->acdirmin          = NFS_DEF_ACDIRMIN;
1568         args->acdirmax          = NFS_DEF_ACDIRMAX;
1569         args->mount_server.port = 0;    /* autobind unless user sets port */
1570         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1571         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1572         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1573
1574         switch (data->version) {
1575         case 1:
1576                 data->namlen = 0;
1577         case 2:
1578                 data->bsize = 0;
1579         case 3:
1580                 if (data->flags & NFS_MOUNT_VER3)
1581                         goto out_no_v3;
1582                 data->root.size = NFS2_FHSIZE;
1583                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1584         case 4:
1585                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1586                         goto out_no_sec;
1587         case 5:
1588                 memset(data->context, 0, sizeof(data->context));
1589         case 6:
1590                 if (data->flags & NFS_MOUNT_VER3) {
1591                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1592                                 goto out_invalid_fh;
1593                         mntfh->size = data->root.size;
1594                 } else
1595                         mntfh->size = NFS2_FHSIZE;
1596
1597
1598                 memcpy(mntfh->data, data->root.data, mntfh->size);
1599                 if (mntfh->size < sizeof(mntfh->data))
1600                         memset(mntfh->data + mntfh->size, 0,
1601                                sizeof(mntfh->data) - mntfh->size);
1602
1603                 /*
1604                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1605                  * can deal with.
1606                  */
1607                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1608                 args->rsize             = data->rsize;
1609                 args->wsize             = data->wsize;
1610                 args->timeo             = data->timeo;
1611                 args->retrans           = data->retrans;
1612                 args->acregmin          = data->acregmin;
1613                 args->acregmax          = data->acregmax;
1614                 args->acdirmin          = data->acdirmin;
1615                 args->acdirmax          = data->acdirmax;
1616
1617                 memcpy(&args->nfs_server.address, &data->addr,
1618                        sizeof(data->addr));
1619                 args->nfs_server.addrlen = sizeof(data->addr);
1620                 if (!nfs_verify_server_address((struct sockaddr *)
1621                                                 &args->nfs_server.address))
1622                         goto out_no_address;
1623
1624                 if (!(data->flags & NFS_MOUNT_TCP))
1625                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1626                 /* N.B. caller will free nfs_server.hostname in all cases */
1627                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1628                 args->namlen            = data->namlen;
1629                 args->bsize             = data->bsize;
1630
1631                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1632                         args->auth_flavors[0] = data->pseudoflavor;
1633                 if (!args->nfs_server.hostname)
1634                         goto out_nomem;
1635
1636                 /*
1637                  * The legacy version 6 binary mount data from userspace has a
1638                  * field used only to transport selinux information into the
1639                  * the kernel.  To continue to support that functionality we
1640                  * have a touch of selinux knowledge here in the NFS code. The
1641                  * userspace code converted context=blah to just blah so we are
1642                  * converting back to the full string selinux understands.
1643                  */
1644                 if (data->context[0]){
1645 #ifdef CONFIG_SECURITY_SELINUX
1646                         int rc;
1647                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1648                         if (!opts_str)
1649                                 return -ENOMEM;
1650                         strcpy(opts_str, "context=");
1651                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1652                         strcat(opts_str, &data->context[0]);
1653                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1654                         kfree(opts_str);
1655                         if (rc)
1656                                 return rc;
1657 #else
1658                         return -EINVAL;
1659 #endif
1660                 }
1661
1662                 break;
1663         default: {
1664                 int status;
1665
1666                 if (nfs_parse_mount_options((char *)options, args) == 0)
1667                         return -EINVAL;
1668
1669                 if (!nfs_verify_server_address((struct sockaddr *)
1670                                                 &args->nfs_server.address))
1671                         goto out_no_address;
1672
1673                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
1674                                 args->nfs_server.port);
1675
1676                 nfs_set_mount_transport_protocol(args);
1677
1678                 status = nfs_parse_devname(dev_name,
1679                                            &args->nfs_server.hostname,
1680                                            PAGE_SIZE,
1681                                            &args->nfs_server.export_path,
1682                                            NFS_MAXPATHLEN);
1683                 if (!status)
1684                         status = nfs_try_mount(args, mntfh);
1685
1686                 kfree(args->nfs_server.export_path);
1687                 args->nfs_server.export_path = NULL;
1688
1689                 if (status)
1690                         return status;
1691
1692                 break;
1693                 }
1694         }
1695
1696 #ifndef CONFIG_NFS_V3
1697         if (args->flags & NFS_MOUNT_VER3)
1698                 goto out_v3_not_compiled;
1699 #endif /* !CONFIG_NFS_V3 */
1700
1701         return 0;
1702
1703 out_no_data:
1704         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1705         return -EINVAL;
1706
1707 out_no_v3:
1708         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1709                  data->version);
1710         return -EINVAL;
1711
1712 out_no_sec:
1713         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1714         return -EINVAL;
1715
1716 #ifndef CONFIG_NFS_V3
1717 out_v3_not_compiled:
1718         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1719         return -EPROTONOSUPPORT;
1720 #endif /* !CONFIG_NFS_V3 */
1721
1722 out_nomem:
1723         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1724         return -ENOMEM;
1725
1726 out_no_address:
1727         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1728         return -EINVAL;
1729
1730 out_invalid_fh:
1731         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1732         return -EINVAL;
1733 }
1734
1735 static int
1736 nfs_compare_remount_data(struct nfs_server *nfss,
1737                          struct nfs_parsed_mount_data *data)
1738 {
1739         if (data->flags != nfss->flags ||
1740             data->rsize != nfss->rsize ||
1741             data->wsize != nfss->wsize ||
1742             data->retrans != nfss->client->cl_timeout->to_retries ||
1743             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1744             data->acregmin != nfss->acregmin / HZ ||
1745             data->acregmax != nfss->acregmax / HZ ||
1746             data->acdirmin != nfss->acdirmin / HZ ||
1747             data->acdirmax != nfss->acdirmax / HZ ||
1748             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1749             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1750             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1751                    data->nfs_server.addrlen) != 0)
1752                 return -EINVAL;
1753
1754         return 0;
1755 }
1756
1757 static int
1758 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1759 {
1760         int error;
1761         struct nfs_server *nfss = sb->s_fs_info;
1762         struct nfs_parsed_mount_data *data;
1763         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1764         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1765         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1766
1767         /*
1768          * Userspace mount programs that send binary options generally send
1769          * them populated with default values. We have no way to know which
1770          * ones were explicitly specified. Fall back to legacy behavior and
1771          * just return success.
1772          */
1773         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1774             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1775                                            options->version <= 6))))
1776                 return 0;
1777
1778         data = kzalloc(sizeof(*data), GFP_KERNEL);
1779         if (data == NULL)
1780                 return -ENOMEM;
1781
1782         lock_kernel();
1783         /* fill out struct with values from existing mount */
1784         data->flags = nfss->flags;
1785         data->rsize = nfss->rsize;
1786         data->wsize = nfss->wsize;
1787         data->retrans = nfss->client->cl_timeout->to_retries;
1788         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1789         data->acregmin = nfss->acregmin / HZ;
1790         data->acregmax = nfss->acregmax / HZ;
1791         data->acdirmin = nfss->acdirmin / HZ;
1792         data->acdirmax = nfss->acdirmax / HZ;
1793         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1794         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1795         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1796                 data->nfs_server.addrlen);
1797
1798         /* overwrite those values with any that were specified */
1799         error = nfs_parse_mount_options((char *)options, data);
1800         if (error < 0)
1801                 goto out;
1802
1803         /* compare new mount options with old ones */
1804         error = nfs_compare_remount_data(nfss, data);
1805 out:
1806         kfree(data);
1807         unlock_kernel();
1808         return error;
1809 }
1810
1811 /*
1812  * Initialise the common bits of the superblock
1813  */
1814 static inline void nfs_initialise_sb(struct super_block *sb)
1815 {
1816         struct nfs_server *server = NFS_SB(sb);
1817
1818         sb->s_magic = NFS_SUPER_MAGIC;
1819
1820         /* We probably want something more informative here */
1821         snprintf(sb->s_id, sizeof(sb->s_id),
1822                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1823
1824         if (sb->s_blocksize == 0)
1825                 sb->s_blocksize = nfs_block_bits(server->wsize,
1826                                                  &sb->s_blocksize_bits);
1827
1828         if (server->flags & NFS_MOUNT_NOAC)
1829                 sb->s_flags |= MS_SYNCHRONOUS;
1830
1831         nfs_super_set_maxbytes(sb, server->maxfilesize);
1832 }
1833
1834 /*
1835  * Finish setting up an NFS2/3 superblock
1836  */
1837 static void nfs_fill_super(struct super_block *sb,
1838                            struct nfs_parsed_mount_data *data)
1839 {
1840         struct nfs_server *server = NFS_SB(sb);
1841
1842         sb->s_blocksize_bits = 0;
1843         sb->s_blocksize = 0;
1844         if (data->bsize)
1845                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1846
1847         if (server->flags & NFS_MOUNT_VER3) {
1848                 /* The VFS shouldn't apply the umask to mode bits. We will do
1849                  * so ourselves when necessary.
1850                  */
1851                 sb->s_flags |= MS_POSIXACL;
1852                 sb->s_time_gran = 1;
1853         }
1854
1855         sb->s_op = &nfs_sops;
1856         nfs_initialise_sb(sb);
1857 }
1858
1859 /*
1860  * Finish setting up a cloned NFS2/3 superblock
1861  */
1862 static void nfs_clone_super(struct super_block *sb,
1863                             const struct super_block *old_sb)
1864 {
1865         struct nfs_server *server = NFS_SB(sb);
1866
1867         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1868         sb->s_blocksize = old_sb->s_blocksize;
1869         sb->s_maxbytes = old_sb->s_maxbytes;
1870
1871         if (server->flags & NFS_MOUNT_VER3) {
1872                 /* The VFS shouldn't apply the umask to mode bits. We will do
1873                  * so ourselves when necessary.
1874                  */
1875                 sb->s_flags |= MS_POSIXACL;
1876                 sb->s_time_gran = 1;
1877         }
1878
1879         sb->s_op = old_sb->s_op;
1880         nfs_initialise_sb(sb);
1881 }
1882
1883 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1884 {
1885         const struct nfs_server *a = s->s_fs_info;
1886         const struct rpc_clnt *clnt_a = a->client;
1887         const struct rpc_clnt *clnt_b = b->client;
1888
1889         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1890                 goto Ebusy;
1891         if (a->nfs_client != b->nfs_client)
1892                 goto Ebusy;
1893         if (a->flags != b->flags)
1894                 goto Ebusy;
1895         if (a->wsize != b->wsize)
1896                 goto Ebusy;
1897         if (a->rsize != b->rsize)
1898                 goto Ebusy;
1899         if (a->acregmin != b->acregmin)
1900                 goto Ebusy;
1901         if (a->acregmax != b->acregmax)
1902                 goto Ebusy;
1903         if (a->acdirmin != b->acdirmin)
1904                 goto Ebusy;
1905         if (a->acdirmax != b->acdirmax)
1906                 goto Ebusy;
1907         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1908                 goto Ebusy;
1909         return 1;
1910 Ebusy:
1911         return 0;
1912 }
1913
1914 struct nfs_sb_mountdata {
1915         struct nfs_server *server;
1916         int mntflags;
1917 };
1918
1919 static int nfs_set_super(struct super_block *s, void *data)
1920 {
1921         struct nfs_sb_mountdata *sb_mntdata = data;
1922         struct nfs_server *server = sb_mntdata->server;
1923         int ret;
1924
1925         s->s_flags = sb_mntdata->mntflags;
1926         s->s_fs_info = server;
1927         ret = set_anon_super(s, server);
1928         if (ret == 0)
1929                 server->s_dev = s->s_dev;
1930         return ret;
1931 }
1932
1933 static int nfs_compare_super_address(struct nfs_server *server1,
1934                                      struct nfs_server *server2)
1935 {
1936         struct sockaddr *sap1, *sap2;
1937
1938         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1939         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1940
1941         if (sap1->sa_family != sap2->sa_family)
1942                 return 0;
1943
1944         switch (sap1->sa_family) {
1945         case AF_INET: {
1946                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1947                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1948                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1949                         return 0;
1950                 if (sin1->sin_port != sin2->sin_port)
1951                         return 0;
1952                 break;
1953         }
1954         case AF_INET6: {
1955                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1956                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1957                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1958                         return 0;
1959                 if (sin1->sin6_port != sin2->sin6_port)
1960                         return 0;
1961                 break;
1962         }
1963         default:
1964                 return 0;
1965         }
1966
1967         return 1;
1968 }
1969
1970 static int nfs_compare_super(struct super_block *sb, void *data)
1971 {
1972         struct nfs_sb_mountdata *sb_mntdata = data;
1973         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1974         int mntflags = sb_mntdata->mntflags;
1975
1976         if (!nfs_compare_super_address(old, server))
1977                 return 0;
1978         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1979         if (old->flags & NFS_MOUNT_UNSHARED)
1980                 return 0;
1981         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1982                 return 0;
1983         return nfs_compare_mount_options(sb, server, mntflags);
1984 }
1985
1986 static int nfs_bdi_register(struct nfs_server *server)
1987 {
1988         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
1989 }
1990
1991 static int nfs_get_sb(struct file_system_type *fs_type,
1992         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1993 {
1994         struct nfs_server *server = NULL;
1995         struct super_block *s;
1996         struct nfs_parsed_mount_data *data;
1997         struct nfs_fh *mntfh;
1998         struct dentry *mntroot;
1999         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2000         struct nfs_sb_mountdata sb_mntdata = {
2001                 .mntflags = flags,
2002         };
2003         int error = -ENOMEM;
2004
2005         data = kzalloc(sizeof(*data), GFP_KERNEL);
2006         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2007         if (data == NULL || mntfh == NULL)
2008                 goto out_free_fh;
2009
2010         security_init_mnt_opts(&data->lsm_opts);
2011
2012         /* Validate the mount data */
2013         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2014         if (error < 0)
2015                 goto out;
2016
2017         /* Get a volume representation */
2018         server = nfs_create_server(data, mntfh);
2019         if (IS_ERR(server)) {
2020                 error = PTR_ERR(server);
2021                 goto out;
2022         }
2023         sb_mntdata.server = server;
2024
2025         if (server->flags & NFS_MOUNT_UNSHARED)
2026                 compare_super = NULL;
2027
2028         /* Get a superblock - note that we may end up sharing one that already exists */
2029         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2030         if (IS_ERR(s)) {
2031                 error = PTR_ERR(s);
2032                 goto out_err_nosb;
2033         }
2034
2035         if (s->s_fs_info != server) {
2036                 nfs_free_server(server);
2037                 server = NULL;
2038         } else {
2039                 error = nfs_bdi_register(server);
2040                 if (error)
2041                         goto error_splat_super;
2042         }
2043
2044         if (!s->s_root) {
2045                 /* initial superblock/root creation */
2046                 nfs_fill_super(s, data);
2047                 nfs_fscache_get_super_cookie(s, data);
2048         }
2049
2050         mntroot = nfs_get_root(s, mntfh);
2051         if (IS_ERR(mntroot)) {
2052                 error = PTR_ERR(mntroot);
2053                 goto error_splat_super;
2054         }
2055
2056         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2057         if (error)
2058                 goto error_splat_root;
2059
2060         s->s_flags |= MS_ACTIVE;
2061         mnt->mnt_sb = s;
2062         mnt->mnt_root = mntroot;
2063         error = 0;
2064
2065 out:
2066         kfree(data->nfs_server.hostname);
2067         kfree(data->mount_server.hostname);
2068         kfree(data->fscache_uniq);
2069         security_free_mnt_opts(&data->lsm_opts);
2070 out_free_fh:
2071         kfree(mntfh);
2072         kfree(data);
2073         return error;
2074
2075 out_err_nosb:
2076         nfs_free_server(server);
2077         goto out;
2078
2079 error_splat_root:
2080         dput(mntroot);
2081 error_splat_super:
2082         deactivate_locked_super(s);
2083         goto out;
2084 }
2085
2086 /*
2087  * Destroy an NFS2/3 superblock
2088  */
2089 static void nfs_kill_super(struct super_block *s)
2090 {
2091         struct nfs_server *server = NFS_SB(s);
2092
2093         bdi_unregister(&server->backing_dev_info);
2094         kill_anon_super(s);
2095         nfs_fscache_release_super_cookie(s);
2096         nfs_free_server(server);
2097 }
2098
2099 /*
2100  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2101  */
2102 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2103                            const char *dev_name, void *raw_data,
2104                            struct vfsmount *mnt)
2105 {
2106         struct nfs_clone_mount *data = raw_data;
2107         struct super_block *s;
2108         struct nfs_server *server;
2109         struct dentry *mntroot;
2110         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2111         struct nfs_sb_mountdata sb_mntdata = {
2112                 .mntflags = flags,
2113         };
2114         int error;
2115
2116         dprintk("--> nfs_xdev_get_sb()\n");
2117
2118         /* create a new volume representation */
2119         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2120         if (IS_ERR(server)) {
2121                 error = PTR_ERR(server);
2122                 goto out_err_noserver;
2123         }
2124         sb_mntdata.server = server;
2125
2126         if (server->flags & NFS_MOUNT_UNSHARED)
2127                 compare_super = NULL;
2128
2129         /* Get a superblock - note that we may end up sharing one that already exists */
2130         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2131         if (IS_ERR(s)) {
2132                 error = PTR_ERR(s);
2133                 goto out_err_nosb;
2134         }
2135
2136         if (s->s_fs_info != server) {
2137                 nfs_free_server(server);
2138                 server = NULL;
2139         } else {
2140                 error = nfs_bdi_register(server);
2141                 if (error)
2142                         goto error_splat_super;
2143         }
2144
2145         if (!s->s_root) {
2146                 /* initial superblock/root creation */
2147                 nfs_clone_super(s, data->sb);
2148         }
2149
2150         mntroot = nfs_get_root(s, data->fh);
2151         if (IS_ERR(mntroot)) {
2152                 error = PTR_ERR(mntroot);
2153                 goto error_splat_super;
2154         }
2155         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2156                 dput(mntroot);
2157                 error = -ESTALE;
2158                 goto error_splat_super;
2159         }
2160
2161         s->s_flags |= MS_ACTIVE;
2162         mnt->mnt_sb = s;
2163         mnt->mnt_root = mntroot;
2164
2165         /* clone any lsm security options from the parent to the new sb */
2166         security_sb_clone_mnt_opts(data->sb, s);
2167
2168         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2169         return 0;
2170
2171 out_err_nosb:
2172         nfs_free_server(server);
2173 out_err_noserver:
2174         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2175         return error;
2176
2177 error_splat_super:
2178         deactivate_locked_super(s);
2179         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2180         return error;
2181 }
2182
2183 #ifdef CONFIG_NFS_V4
2184
2185 /*
2186  * Finish setting up a cloned NFS4 superblock
2187  */
2188 static void nfs4_clone_super(struct super_block *sb,
2189                             const struct super_block *old_sb)
2190 {
2191         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2192         sb->s_blocksize = old_sb->s_blocksize;
2193         sb->s_maxbytes = old_sb->s_maxbytes;
2194         sb->s_time_gran = 1;
2195         sb->s_op = old_sb->s_op;
2196         nfs_initialise_sb(sb);
2197 }
2198
2199 /*
2200  * Set up an NFS4 superblock
2201  */
2202 static void nfs4_fill_super(struct super_block *sb)
2203 {
2204         sb->s_time_gran = 1;
2205         sb->s_op = &nfs4_sops;
2206         nfs_initialise_sb(sb);
2207 }
2208
2209 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2210 {
2211         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2212 }
2213
2214 /*
2215  * Validate NFSv4 mount options
2216  */
2217 static int nfs4_validate_mount_data(void *options,
2218                                     struct nfs_parsed_mount_data *args,
2219                                     const char *dev_name)
2220 {
2221         struct sockaddr_in *ap;
2222         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2223         char *c;
2224
2225         if (data == NULL)
2226                 goto out_no_data;
2227
2228         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2229         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2230         args->acregmin          = NFS_DEF_ACREGMIN;
2231         args->acregmax          = NFS_DEF_ACREGMAX;
2232         args->acdirmin          = NFS_DEF_ACDIRMIN;
2233         args->acdirmax          = NFS_DEF_ACDIRMAX;
2234         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2235         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2236         args->auth_flavor_len   = 0;
2237
2238         switch (data->version) {
2239         case 1:
2240                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2241                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2242                         goto out_no_address;
2243                 if (data->host_addrlen == 0)
2244                         goto out_no_address;
2245                 args->nfs_server.addrlen = data->host_addrlen;
2246                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2247                         return -EFAULT;
2248                 if (!nfs_verify_server_address((struct sockaddr *)
2249                                                 &args->nfs_server.address))
2250                         goto out_no_address;
2251
2252                 if (data->auth_flavourlen) {
2253                         if (data->auth_flavourlen > 1)
2254                                 goto out_inval_auth;
2255                         if (copy_from_user(&args->auth_flavors[0],
2256                                            data->auth_flavours,
2257                                            sizeof(args->auth_flavors[0])))
2258                                 return -EFAULT;
2259                 }
2260
2261                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2262                 if (IS_ERR(c))
2263                         return PTR_ERR(c);
2264                 args->nfs_server.hostname = c;
2265
2266                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2267                 if (IS_ERR(c))
2268                         return PTR_ERR(c);
2269                 args->nfs_server.export_path = c;
2270                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2271
2272                 c = strndup_user(data->client_addr.data, 16);
2273                 if (IS_ERR(c))
2274                         return PTR_ERR(c);
2275                 args->client_address = c;
2276
2277                 /*
2278                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2279                  * can deal with.
2280                  */
2281
2282                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2283                 args->rsize     = data->rsize;
2284                 args->wsize     = data->wsize;
2285                 args->timeo     = data->timeo;
2286                 args->retrans   = data->retrans;
2287                 args->acregmin  = data->acregmin;
2288                 args->acregmax  = data->acregmax;
2289                 args->acdirmin  = data->acdirmin;
2290                 args->acdirmax  = data->acdirmax;
2291                 args->nfs_server.protocol = data->proto;
2292                 nfs_validate_transport_protocol(args);
2293
2294                 break;
2295         default: {
2296                 int status;
2297
2298                 if (nfs_parse_mount_options((char *)options, args) == 0)
2299                         return -EINVAL;
2300
2301                 if (!nfs_verify_server_address((struct sockaddr *)
2302                                                 &args->nfs_server.address))
2303                         return -EINVAL;
2304
2305                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
2306                                 args->nfs_server.port);
2307
2308                 nfs_validate_transport_protocol(args);
2309
2310                 nfs4_validate_mount_flags(args);
2311
2312                 if (args->auth_flavor_len > 1)
2313                         goto out_inval_auth;
2314
2315                 if (args->client_address == NULL)
2316                         goto out_no_client_address;
2317
2318                 status = nfs_parse_devname(dev_name,
2319                                            &args->nfs_server.hostname,
2320                                            NFS4_MAXNAMLEN,
2321                                            &args->nfs_server.export_path,
2322                                            NFS4_MAXPATHLEN);
2323                 if (status < 0)
2324                         return status;
2325
2326                 break;
2327                 }
2328         }
2329
2330         return 0;
2331
2332 out_no_data:
2333         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2334         return -EINVAL;
2335
2336 out_inval_auth:
2337         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2338                  data->auth_flavourlen);
2339         return -EINVAL;
2340
2341 out_no_address:
2342         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2343         return -EINVAL;
2344
2345 out_no_client_address:
2346         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2347         return -EINVAL;
2348 }
2349
2350 /*
2351  * Get the superblock for an NFS4 mountpoint
2352  */
2353 static int nfs4_get_sb(struct file_system_type *fs_type,
2354         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2355 {
2356         struct nfs_parsed_mount_data *data;
2357         struct super_block *s;
2358         struct nfs_server *server;
2359         struct nfs_fh *mntfh;
2360         struct dentry *mntroot;
2361         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2362         struct nfs_sb_mountdata sb_mntdata = {
2363                 .mntflags = flags,
2364         };
2365         int error = -ENOMEM;
2366
2367         data = kzalloc(sizeof(*data), GFP_KERNEL);
2368         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2369         if (data == NULL || mntfh == NULL)
2370                 goto out_free_fh;
2371
2372         security_init_mnt_opts(&data->lsm_opts);
2373
2374         /* Validate the mount data */
2375         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2376         if (error < 0)
2377                 goto out;
2378
2379         /* Get a volume representation */
2380         server = nfs4_create_server(data, mntfh);
2381         if (IS_ERR(server)) {
2382                 error = PTR_ERR(server);
2383                 goto out;
2384         }
2385         sb_mntdata.server = server;
2386
2387         if (server->flags & NFS4_MOUNT_UNSHARED)
2388                 compare_super = NULL;
2389
2390         /* Get a superblock - note that we may end up sharing one that already exists */
2391         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2392         if (IS_ERR(s)) {
2393                 error = PTR_ERR(s);
2394                 goto out_free;
2395         }
2396
2397         if (s->s_fs_info != server) {
2398                 nfs_free_server(server);
2399                 server = NULL;
2400         } else {
2401                 error = nfs_bdi_register(server);
2402                 if (error)
2403                         goto error_splat_super;
2404         }
2405
2406         if (!s->s_root) {
2407                 /* initial superblock/root creation */
2408                 nfs4_fill_super(s);
2409                 nfs_fscache_get_super_cookie(s, data);
2410         }
2411
2412         mntroot = nfs4_get_root(s, mntfh);
2413         if (IS_ERR(mntroot)) {
2414                 error = PTR_ERR(mntroot);
2415                 goto error_splat_super;
2416         }
2417
2418         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2419         if (error)
2420                 goto error_splat_root;
2421
2422         s->s_flags |= MS_ACTIVE;
2423         mnt->mnt_sb = s;
2424         mnt->mnt_root = mntroot;
2425         error = 0;
2426
2427 out:
2428         kfree(data->client_address);
2429         kfree(data->nfs_server.export_path);
2430         kfree(data->nfs_server.hostname);
2431         kfree(data->fscache_uniq);
2432         security_free_mnt_opts(&data->lsm_opts);
2433 out_free_fh:
2434         kfree(mntfh);
2435         kfree(data);
2436         return error;
2437
2438 out_free:
2439         nfs_free_server(server);
2440         goto out;
2441
2442 error_splat_root:
2443         dput(mntroot);
2444 error_splat_super:
2445         deactivate_locked_super(s);
2446         goto out;
2447 }
2448
2449 static void nfs4_kill_super(struct super_block *sb)
2450 {
2451         struct nfs_server *server = NFS_SB(sb);
2452
2453         nfs_super_return_all_delegations(sb);
2454         kill_anon_super(sb);
2455
2456         nfs4_renewd_prepare_shutdown(server);
2457         nfs_fscache_release_super_cookie(sb);
2458         nfs_free_server(server);
2459 }
2460
2461 /*
2462  * Clone an NFS4 server record on xdev traversal (FSID-change)
2463  */
2464 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2465                             const char *dev_name, void *raw_data,
2466                             struct vfsmount *mnt)
2467 {
2468         struct nfs_clone_mount *data = raw_data;
2469         struct super_block *s;
2470         struct nfs_server *server;
2471         struct dentry *mntroot;
2472         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2473         struct nfs_sb_mountdata sb_mntdata = {
2474                 .mntflags = flags,
2475         };
2476         int error;
2477
2478         dprintk("--> nfs4_xdev_get_sb()\n");
2479
2480         /* create a new volume representation */
2481         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2482         if (IS_ERR(server)) {
2483                 error = PTR_ERR(server);
2484                 goto out_err_noserver;
2485         }
2486         sb_mntdata.server = server;
2487
2488         if (server->flags & NFS4_MOUNT_UNSHARED)
2489                 compare_super = NULL;
2490
2491         /* Get a superblock - note that we may end up sharing one that already exists */
2492         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2493         if (IS_ERR(s)) {
2494                 error = PTR_ERR(s);
2495                 goto out_err_nosb;
2496         }
2497
2498         if (s->s_fs_info != server) {
2499                 nfs_free_server(server);
2500                 server = NULL;
2501         } else {
2502                 error = nfs_bdi_register(server);
2503                 if (error)
2504                         goto error_splat_super;
2505         }
2506
2507         if (!s->s_root) {
2508                 /* initial superblock/root creation */
2509                 nfs4_clone_super(s, data->sb);
2510         }
2511
2512         mntroot = nfs4_get_root(s, data->fh);
2513         if (IS_ERR(mntroot)) {
2514                 error = PTR_ERR(mntroot);
2515                 goto error_splat_super;
2516         }
2517         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2518                 dput(mntroot);
2519                 error = -ESTALE;
2520                 goto error_splat_super;
2521         }
2522
2523         s->s_flags |= MS_ACTIVE;
2524         mnt->mnt_sb = s;
2525         mnt->mnt_root = mntroot;
2526
2527         security_sb_clone_mnt_opts(data->sb, s);
2528
2529         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2530         return 0;
2531
2532 out_err_nosb:
2533         nfs_free_server(server);
2534 out_err_noserver:
2535         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2536         return error;
2537
2538 error_splat_super:
2539         deactivate_locked_super(s);
2540         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2541         return error;
2542 }
2543
2544 /*
2545  * Create an NFS4 server record on referral traversal
2546  */
2547 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2548                                 const char *dev_name, void *raw_data,
2549                                 struct vfsmount *mnt)
2550 {
2551         struct nfs_clone_mount *data = raw_data;
2552         struct super_block *s;
2553         struct nfs_server *server;
2554         struct dentry *mntroot;
2555         struct nfs_fh mntfh;
2556         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2557         struct nfs_sb_mountdata sb_mntdata = {
2558                 .mntflags = flags,
2559         };
2560         int error;
2561
2562         dprintk("--> nfs4_referral_get_sb()\n");
2563
2564         /* create a new volume representation */
2565         server = nfs4_create_referral_server(data, &mntfh);
2566         if (IS_ERR(server)) {
2567                 error = PTR_ERR(server);
2568                 goto out_err_noserver;
2569         }
2570         sb_mntdata.server = server;
2571
2572         if (server->flags & NFS4_MOUNT_UNSHARED)
2573                 compare_super = NULL;
2574
2575         /* Get a superblock - note that we may end up sharing one that already exists */
2576         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2577         if (IS_ERR(s)) {
2578                 error = PTR_ERR(s);
2579                 goto out_err_nosb;
2580         }
2581
2582         if (s->s_fs_info != server) {
2583                 nfs_free_server(server);
2584                 server = NULL;
2585         } else {
2586                 error = nfs_bdi_register(server);
2587                 if (error)
2588                         goto error_splat_super;
2589         }
2590
2591         if (!s->s_root) {
2592                 /* initial superblock/root creation */
2593                 nfs4_fill_super(s);
2594         }
2595
2596         mntroot = nfs4_get_root(s, &mntfh);
2597         if (IS_ERR(mntroot)) {
2598                 error = PTR_ERR(mntroot);
2599                 goto error_splat_super;
2600         }
2601         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2602                 dput(mntroot);
2603                 error = -ESTALE;
2604                 goto error_splat_super;
2605         }
2606
2607         s->s_flags |= MS_ACTIVE;
2608         mnt->mnt_sb = s;
2609         mnt->mnt_root = mntroot;
2610
2611         security_sb_clone_mnt_opts(data->sb, s);
2612
2613         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2614         return 0;
2615
2616 out_err_nosb:
2617         nfs_free_server(server);
2618 out_err_noserver:
2619         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2620         return error;
2621
2622 error_splat_super:
2623         deactivate_locked_super(s);
2624         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2625         return error;
2626 }
2627
2628 #endif /* CONFIG_NFS_V4 */