git.oblomov.eu Git - linux-2.6/blob - 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         Opt_minorversion,
  94
  95         /* Mount options that take string arguments */
  96         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
  97         Opt_addr, Opt_mountaddr, Opt_clientaddr,
  98         Opt_lookupcache,
  99         Opt_fscache_uniq,
 100
 101         /* Special mount options */
 102         Opt_userspace, Opt_deprecated, Opt_sloppy,
 103
 104         Opt_err
 105 };
 106
 107 static const match_table_t nfs_mount_option_tokens = {
 108         { Opt_userspace, "bg" },
 109         { Opt_userspace, "fg" },
 110         { Opt_userspace, "retry=%s" },
 111
 112         { Opt_sloppy, "sloppy" },
 113
 114         { Opt_soft, "soft" },
 115         { Opt_hard, "hard" },
 116         { Opt_deprecated, "intr" },
 117         { Opt_deprecated, "nointr" },
 118         { Opt_posix, "posix" },
 119         { Opt_noposix, "noposix" },
 120         { Opt_cto, "cto" },
 121         { Opt_nocto, "nocto" },
 122         { Opt_ac, "ac" },
 123         { Opt_noac, "noac" },
 124         { Opt_lock, "lock" },
 125         { Opt_nolock, "nolock" },
 126         { Opt_v2, "v2" },
 127         { Opt_v3, "v3" },
 128         { Opt_udp, "udp" },
 129         { Opt_tcp, "tcp" },
 130         { Opt_rdma, "rdma" },
 131         { Opt_acl, "acl" },
 132         { Opt_noacl, "noacl" },
 133         { Opt_rdirplus, "rdirplus" },
 134         { Opt_nordirplus, "nordirplus" },
 135         { Opt_sharecache, "sharecache" },
 136         { Opt_nosharecache, "nosharecache" },
 137         { Opt_resvport, "resvport" },
 138         { Opt_noresvport, "noresvport" },
 139         { Opt_fscache, "fsc" },
 140         { Opt_fscache_uniq, "fsc=%s" },
 141         { Opt_nofscache, "nofsc" },
 142
 143         { Opt_port, "port=%u" },
 144         { Opt_rsize, "rsize=%u" },
 145         { Opt_wsize, "wsize=%u" },
 146         { Opt_bsize, "bsize=%u" },
 147         { Opt_timeo, "timeo=%u" },
 148         { Opt_retrans, "retrans=%u" },
 149         { Opt_acregmin, "acregmin=%u" },
 150         { Opt_acregmax, "acregmax=%u" },
 151         { Opt_acdirmin, "acdirmin=%u" },
 152         { Opt_acdirmax, "acdirmax=%u" },
 153         { Opt_actimeo, "actimeo=%u" },
 154         { Opt_namelen, "namlen=%u" },
 155         { Opt_mountport, "mountport=%u" },
 156         { Opt_mountvers, "mountvers=%u" },
 157         { Opt_nfsvers, "nfsvers=%u" },
 158         { Opt_nfsvers, "vers=%u" },
 159         { Opt_minorversion, "minorversion=%u" },
 160
 161         { Opt_sec, "sec=%s" },
 162         { Opt_proto, "proto=%s" },
 163         { Opt_mountproto, "mountproto=%s" },
 164         { Opt_addr, "addr=%s" },
 165         { Opt_clientaddr, "clientaddr=%s" },
 166         { Opt_mounthost, "mounthost=%s" },
 167         { Opt_mountaddr, "mountaddr=%s" },
 168
 169         { Opt_lookupcache, "lookupcache=%s" },
 170
 171         { Opt_err, NULL }
 172 };
 173
 174 enum {
 175         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 176
 177         Opt_xprt_err
 178 };
 179
 180 static const match_table_t nfs_xprt_protocol_tokens = {
 181         { Opt_xprt_udp, "udp" },
 182         { Opt_xprt_tcp, "tcp" },
 183         { Opt_xprt_rdma, "rdma" },
 184
 185         { Opt_xprt_err, NULL }
 186 };
 187
 188 enum {
 189         Opt_sec_none, Opt_sec_sys,
 190         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 191         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 192         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 193
 194         Opt_sec_err
 195 };
 196
 197 static const match_table_t nfs_secflavor_tokens = {
 198         { Opt_sec_none, "none" },
 199         { Opt_sec_none, "null" },
 200         { Opt_sec_sys, "sys" },
 201
 202         { Opt_sec_krb5, "krb5" },
 203         { Opt_sec_krb5i, "krb5i" },
 204         { Opt_sec_krb5p, "krb5p" },
 205
 206         { Opt_sec_lkey, "lkey" },
 207         { Opt_sec_lkeyi, "lkeyi" },
 208         { Opt_sec_lkeyp, "lkeyp" },
 209
 210         { Opt_sec_spkm, "spkm3" },
 211         { Opt_sec_spkmi, "spkm3i" },
 212         { Opt_sec_spkmp, "spkm3p" },
 213
 214         { Opt_sec_err, NULL }
 215 };
 216
 217 enum {
 218         Opt_lookupcache_all, Opt_lookupcache_positive,
 219         Opt_lookupcache_none,
 220
 221         Opt_lookupcache_err
 222 };
 223
 224 static match_table_t nfs_lookupcache_tokens = {
 225         { Opt_lookupcache_all, "all" },
 226         { Opt_lookupcache_positive, "pos" },
 227         { Opt_lookupcache_positive, "positive" },
 228         { Opt_lookupcache_none, "none" },
 229
 230         { Opt_lookupcache_err, NULL }
 231 };
 232
 233
 234 static void nfs_umount_begin(struct super_block *);
 235 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 236 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 237 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 238 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 239 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 240                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 241 static void nfs_kill_super(struct super_block *);
 242 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 243
 244 static struct file_system_type nfs_fs_type = {
 245         .owner          = THIS_MODULE,
 246         .name           = "nfs",
 247         .get_sb         = nfs_get_sb,
 248         .kill_sb        = nfs_kill_super,
 249         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 250 };
 251
 252 struct file_system_type nfs_xdev_fs_type = {
 253         .owner          = THIS_MODULE,
 254         .name           = "nfs",
 255         .get_sb         = nfs_xdev_get_sb,
 256         .kill_sb        = nfs_kill_super,
 257         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 258 };
 259
 260 static const struct super_operations nfs_sops = {
 261         .alloc_inode    = nfs_alloc_inode,
 262         .destroy_inode  = nfs_destroy_inode,
 263         .write_inode    = nfs_write_inode,
 264         .statfs         = nfs_statfs,
 265         .clear_inode    = nfs_clear_inode,
 266         .umount_begin   = nfs_umount_begin,
 267         .show_options   = nfs_show_options,
 268         .show_stats     = nfs_show_stats,
 269         .remount_fs     = nfs_remount,
 270 };
 271
 272 #ifdef CONFIG_NFS_V4
 273 static int nfs4_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_xdev_get_sb(struct file_system_type *fs_type,
 276         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 277 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 278         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 279 static void nfs4_kill_super(struct super_block *sb);
 280
 281 static struct file_system_type nfs4_fs_type = {
 282         .owner          = THIS_MODULE,
 283         .name           = "nfs4",
 284         .get_sb         = nfs4_get_sb,
 285         .kill_sb        = nfs4_kill_super,
 286         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 287 };
 288
 289 struct file_system_type nfs4_xdev_fs_type = {
 290         .owner          = THIS_MODULE,
 291         .name           = "nfs4",
 292         .get_sb         = nfs4_xdev_get_sb,
 293         .kill_sb        = nfs4_kill_super,
 294         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 295 };
 296
 297 struct file_system_type nfs4_referral_fs_type = {
 298         .owner          = THIS_MODULE,
 299         .name           = "nfs4",
 300         .get_sb         = nfs4_referral_get_sb,
 301         .kill_sb        = nfs4_kill_super,
 302         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 303 };
 304
 305 static const struct super_operations nfs4_sops = {
 306         .alloc_inode    = nfs_alloc_inode,
 307         .destroy_inode  = nfs_destroy_inode,
 308         .write_inode    = nfs_write_inode,
 309         .statfs         = nfs_statfs,
 310         .clear_inode    = nfs4_clear_inode,
 311         .umount_begin   = nfs_umount_begin,
 312         .show_options   = nfs_show_options,
 313         .show_stats     = nfs_show_stats,
 314         .remount_fs     = nfs_remount,
 315 };
 316 #endif
 317
 318 static struct shrinker acl_shrinker = {
 319         .shrink         = nfs_access_cache_shrinker,
 320         .seeks          = DEFAULT_SEEKS,
 321 };
 322
 323 /*
 324  * Register the NFS filesystems
 325  */
 326 int __init register_nfs_fs(void)
 327 {
 328         int ret;
 329
 330         ret = register_filesystem(&nfs_fs_type);
 331         if (ret < 0)
 332                 goto error_0;
 333
 334         ret = nfs_register_sysctl();
 335         if (ret < 0)
 336                 goto error_1;
 337 #ifdef CONFIG_NFS_V4
 338         ret = register_filesystem(&nfs4_fs_type);
 339         if (ret < 0)
 340                 goto error_2;
 341 #endif
 342         register_shrinker(&acl_shrinker);
 343         return 0;
 344
 345 #ifdef CONFIG_NFS_V4
 346 error_2:
 347         nfs_unregister_sysctl();
 348 #endif
 349 error_1:
 350         unregister_filesystem(&nfs_fs_type);
 351 error_0:
 352         return ret;
 353 }
 354
 355 /*
 356  * Unregister the NFS filesystems
 357  */
 358 void __exit unregister_nfs_fs(void)
 359 {
 360         unregister_shrinker(&acl_shrinker);
 361 #ifdef CONFIG_NFS_V4
 362         unregister_filesystem(&nfs4_fs_type);
 363 #endif
 364         nfs_unregister_sysctl();
 365         unregister_filesystem(&nfs_fs_type);
 366 }
 367
 368 void nfs_sb_active(struct super_block *sb)
 369 {
 370         struct nfs_server *server = NFS_SB(sb);
 371
 372         if (atomic_inc_return(&server->active) == 1)
 373                 atomic_inc(&sb->s_active);
 374 }
 375
 376 void nfs_sb_deactive(struct super_block *sb)
 377 {
 378         struct nfs_server *server = NFS_SB(sb);
 379
 380         if (atomic_dec_and_test(&server->active))
 381                 deactivate_super(sb);
 382 }
 383
 384 /*
 385  * Deliver file system statistics to userspace
 386  */
 387 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 388 {
 389         struct nfs_server *server = NFS_SB(dentry->d_sb);
 390         unsigned char blockbits;
 391         unsigned long blockres;
 392         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 393         struct nfs_fattr fattr;
 394         struct nfs_fsstat res = {
 395                         .fattr = &fattr,
 396         };
 397         int error;
 398
 399         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 400         if (error < 0)
 401                 goto out_err;
 402         buf->f_type = NFS_SUPER_MAGIC;
 403
 404         /*
 405          * Current versions of glibc do not correctly handle the
 406          * case where f_frsize != f_bsize.  Eventually we want to
 407          * report the value of wtmult in this field.
 408          */
 409         buf->f_frsize = dentry->d_sb->s_blocksize;
 410
 411         /*
 412          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 413          * are reported in units of f_frsize.  Linux hasn't had
 414          * an f_frsize field in its statfs struct until recently,
 415          * thus historically Linux's sys_statfs reports these
 416          * fields in units of f_bsize.
 417          */
 418         buf->f_bsize = dentry->d_sb->s_blocksize;
 419         blockbits = dentry->d_sb->s_blocksize_bits;
 420         blockres = (1 << blockbits) - 1;
 421         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 422         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 423         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 424
 425         buf->f_files = res.tfiles;
 426         buf->f_ffree = res.afiles;
 427
 428         buf->f_namelen = server->namelen;
 429
 430         return 0;
 431
 432  out_err:
 433         dprintk("%s: statfs error = %d\n", __func__, -error);
 434         return error;
 435 }
 436
 437 /*
 438  * Map the security flavour number to a name
 439  */
 440 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 441 {
 442         static const struct {
 443                 rpc_authflavor_t flavour;
 444                 const char *str;
 445         } sec_flavours[] = {
 446                 { RPC_AUTH_NULL, "null" },
 447                 { RPC_AUTH_UNIX, "sys" },
 448                 { RPC_AUTH_GSS_KRB5, "krb5" },
 449                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 450                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 451                 { RPC_AUTH_GSS_LKEY, "lkey" },
 452                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 453                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 454                 { RPC_AUTH_GSS_SPKM, "spkm" },
 455                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 456                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 457                 { UINT_MAX, "unknown" }
 458         };
 459         int i;
 460
 461         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 462                 if (sec_flavours[i].flavour == flavour)
 463                         break;
 464         }
 465         return sec_flavours[i].str;
 466 }
 467
 468 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 469                                     int showdefaults)
 470 {
 471         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 472
 473         switch (sap->sa_family) {
 474         case AF_INET: {
 475                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 476                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 477                 break;
 478         }
 479         case AF_INET6: {
 480                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 481                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 482                 break;
 483         }
 484         default:
 485                 if (showdefaults)
 486                         seq_printf(m, ",mountaddr=unspecified");
 487         }
 488
 489         if (nfss->mountd_version || showdefaults)
 490                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 491         if (nfss->mountd_port || showdefaults)
 492                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 493
 494         switch (nfss->mountd_protocol) {
 495         case IPPROTO_UDP:
 496                 seq_printf(m, ",mountproto=udp");
 497                 break;
 498         case IPPROTO_TCP:
 499                 seq_printf(m, ",mountproto=tcp");
 500                 break;
 501         default:
 502                 if (showdefaults)
 503                         seq_printf(m, ",mountproto=auto");
 504         }
 505 }
 506
 507 /*
 508  * Describe the mount options in force on this server representation
 509  */
 510 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 511                                    int showdefaults)
 512 {
 513         static const struct proc_nfs_info {
 514                 int flag;
 515                 const char *str;
 516                 const char *nostr;
 517         } nfs_info[] = {
 518                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 519                 { NFS_MOUNT_INTR, ",intr", ",nointr" },
 520                 { NFS_MOUNT_POSIX, ",posix", "" },
 521                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 522                 { NFS_MOUNT_NOAC, ",noac", "" },
 523                 { NFS_MOUNT_NONLM, ",nolock", "" },
 524                 { NFS_MOUNT_NOACL, ",noacl", "" },
 525                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 526                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 527                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 528                 { 0, NULL, NULL }
 529         };
 530         const struct proc_nfs_info *nfs_infop;
 531         struct nfs_client *clp = nfss->nfs_client;
 532         u32 version = clp->rpc_ops->version;
 533
 534         seq_printf(m, ",vers=%u", version);
 535         seq_printf(m, ",rsize=%u", nfss->rsize);
 536         seq_printf(m, ",wsize=%u", nfss->wsize);
 537         if (nfss->bsize != 0)
 538                 seq_printf(m, ",bsize=%u", nfss->bsize);
 539         seq_printf(m, ",namlen=%u", nfss->namelen);
 540         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 541                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 542         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 543                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 544         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 545                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 546         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 547                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 548         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 549                 if (nfss->flags & nfs_infop->flag)
 550                         seq_puts(m, nfs_infop->str);
 551                 else
 552                         seq_puts(m, nfs_infop->nostr);
 553         }
 554         seq_printf(m, ",proto=%s",
 555                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 556         if (version == 4) {
 557                 if (nfss->port != NFS_PORT)
 558                         seq_printf(m, ",port=%u", nfss->port);
 559         } else
 560                 if (nfss->port)
 561                         seq_printf(m, ",port=%u", nfss->port);
 562
 563         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 564         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 565         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 566
 567         if (version != 4)
 568                 nfs_show_mountd_options(m, nfss, showdefaults);
 569
 570 #ifdef CONFIG_NFS_V4
 571         if (clp->rpc_ops->version == 4)
 572                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 573 #endif
 574         if (nfss->options & NFS_OPTION_FSCACHE)
 575                 seq_printf(m, ",fsc");
 576 }
 577
 578 /*
 579  * Describe the mount options on this VFS mountpoint
 580  */
 581 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 582 {
 583         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 584
 585         nfs_show_mount_options(m, nfss, 0);
 586
 587         seq_printf(m, ",addr=%s",
 588                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 589                                                         RPC_DISPLAY_ADDR));
 590
 591         return 0;
 592 }
 593
 594 /*
 595  * Present statistical information for this VFS mountpoint
 596  */
 597 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 598 {
 599         int i, cpu;
 600         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 601         struct rpc_auth *auth = nfss->client->cl_auth;
 602         struct nfs_iostats totals = { };
 603
 604         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 605
 606         /*
 607          * Display all mount option settings
 608          */
 609         seq_printf(m, "\n\topts:\t");
 610         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 611         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 612         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 613         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 614         nfs_show_mount_options(m, nfss, 1);
 615
 616         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 617
 618         seq_printf(m, "\n\tcaps:\t");
 619         seq_printf(m, "caps=0x%x", nfss->caps);
 620         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 621         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 622         seq_printf(m, ",bsize=%u", nfss->bsize);
 623         seq_printf(m, ",namlen=%u", nfss->namelen);
 624
 625 #ifdef CONFIG_NFS_V4
 626         if (nfss->nfs_client->rpc_ops->version == 4) {
 627                 seq_printf(m, "\n\tnfsv4:\t");
 628                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 629                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 630                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 631         }
 632 #endif
 633
 634         /*
 635          * Display security flavor in effect for this mount
 636          */
 637         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 638         if (auth->au_flavor)
 639                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 640
 641         /*
 642          * Display superblock I/O counters
 643          */
 644         for_each_possible_cpu(cpu) {
 645                 struct nfs_iostats *stats;
 646
 647                 preempt_disable();
 648                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 649
 650                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 651                         totals.events[i] += stats->events[i];
 652                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 653                         totals.bytes[i] += stats->bytes[i];
 654 #ifdef CONFIG_NFS_FSCACHE
 655                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 656                         totals.fscache[i] += stats->fscache[i];
 657 #endif
 658
 659                 preempt_enable();
 660         }
 661
 662         seq_printf(m, "\n\tevents:\t");
 663         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 664                 seq_printf(m, "%lu ", totals.events[i]);
 665         seq_printf(m, "\n\tbytes:\t");
 666         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 667                 seq_printf(m, "%Lu ", totals.bytes[i]);
 668 #ifdef CONFIG_NFS_FSCACHE
 669         if (nfss->options & NFS_OPTION_FSCACHE) {
 670                 seq_printf(m, "\n\tfsc:\t");
 671                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 672                         seq_printf(m, "%Lu ", totals.bytes[i]);
 673         }
 674 #endif
 675         seq_printf(m, "\n");
 676
 677         rpc_print_iostats(m, nfss->client);
 678
 679         return 0;
 680 }
 681
 682 /*
 683  * Begin unmount by attempting to remove all automounted mountpoints we added
 684  * in response to xdev traversals and referrals
 685  */
 686 static void nfs_umount_begin(struct super_block *sb)
 687 {
 688         struct nfs_server *server;
 689         struct rpc_clnt *rpc;
 690
 691         lock_kernel();
 692
 693         server = NFS_SB(sb);
 694         /* -EIO all pending I/O */
 695         rpc = server->client_acl;
 696         if (!IS_ERR(rpc))
 697                 rpc_killall_tasks(rpc);
 698         rpc = server->client;
 699         if (!IS_ERR(rpc))
 700                 rpc_killall_tasks(rpc);
 701
 702         unlock_kernel();
 703 }
 704
 705 /*
 706  * Sanity-check a server address provided by the mount command.
 707  *
 708  * Address family must be initialized, and address must not be
 709  * the ANY address for that family.
 710  */
 711 static int nfs_verify_server_address(struct sockaddr *addr)
 712 {
 713         switch (addr->sa_family) {
 714         case AF_INET: {
 715                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 716                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 717         }
 718         case AF_INET6: {
 719                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 720                 return !ipv6_addr_any(sa);
 721         }
 722         }
 723
 724         return 0;
 725 }
 726
 727 static void nfs_parse_ipv4_address(char *string, size_t str_len,
 728                                    struct sockaddr *sap, size_t *addr_len)
 729 {
 730         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 731         u8 *addr = (u8 *)&sin->sin_addr.s_addr;
 732
 733         if (str_len <= INET_ADDRSTRLEN) {
 734                 dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
 735                                 (int)str_len, string);
 736
 737                 sin->sin_family = AF_INET;
 738                 *addr_len = sizeof(*sin);
 739                 if (in4_pton(string, str_len, addr, '\0', NULL))
 740                         return;
 741         }
 742
 743         sap->sa_family = AF_UNSPEC;
 744         *addr_len = 0;
 745 }
 746
 747 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 748 static int nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
 749                                    const char *delim,
 750                                    struct sockaddr_in6 *sin6)
 751 {
 752         char *p;
 753         size_t len;
 754
 755         if ((string + str_len) == delim)
 756                 return 1;
 757
 758         if (*delim != IPV6_SCOPE_DELIMITER)
 759                 return 0;
 760
 761         if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
 762                 return 0;
 763
 764         len = (string + str_len) - delim - 1;
 765         p = kstrndup(delim + 1, len, GFP_KERNEL);
 766         if (p) {
 767                 unsigned long scope_id = 0;
 768                 struct net_device *dev;
 769
 770                 dev = dev_get_by_name(&init_net, p);
 771                 if (dev != NULL) {
 772                         scope_id = dev->ifindex;
 773                         dev_put(dev);
 774                 } else {
 775                         if (strict_strtoul(p, 10, &scope_id) == 0) {
 776                                 kfree(p);
 777                                 return 0;
 778                         }
 779                 }
 780
 781                 kfree(p);
 782
 783                 sin6->sin6_scope_id = scope_id;
 784                 dfprintk(MOUNT, "NFS: IPv6 scope ID = %lu\n", scope_id);
 785                 return 1;
 786         }
 787
 788         return 0;
 789 }
 790
 791 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 792                                    struct sockaddr *sap, size_t *addr_len)
 793 {
 794         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 795         u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
 796         const char *delim;
 797
 798         if (str_len <= INET6_ADDRSTRLEN) {
 799                 dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
 800                                 (int)str_len, string);
 801
 802                 sin6->sin6_family = AF_INET6;
 803                 *addr_len = sizeof(*sin6);
 804                 if (in6_pton(string, str_len, addr,
 805                                         IPV6_SCOPE_DELIMITER, &delim) != 0) {
 806                         if (nfs_parse_ipv6_scope_id(string, str_len,
 807                                                         delim, sin6) != 0)
 808                                 return;
 809                 }
 810         }
 811
 812         sap->sa_family = AF_UNSPEC;
 813         *addr_len = 0;
 814 }
 815 #else
 816 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 817                                    struct sockaddr *sap, size_t *addr_len)
 818 {
 819         sap->sa_family = AF_UNSPEC;
 820         *addr_len = 0;
 821 }
 822 #endif
 823
 824 /*
 825  * Construct a sockaddr based on the contents of a string that contains
 826  * an IP address in presentation format.
 827  *
 828  * If there is a problem constructing the new sockaddr, set the address
 829  * family to AF_UNSPEC.
 830  */
 831 void nfs_parse_ip_address(char *string, size_t str_len,
 832                                  struct sockaddr *sap, size_t *addr_len)
 833 {
 834         unsigned int i, colons;
 835
 836         colons = 0;
 837         for (i = 0; i < str_len; i++)
 838                 if (string[i] == ':')
 839                         colons++;
 840
 841         if (colons >= 2)
 842                 nfs_parse_ipv6_address(string, str_len, sap, addr_len);
 843         else
 844                 nfs_parse_ipv4_address(string, str_len, sap, addr_len);
 845 }
 846
 847 /*
 848  * Sanity check the NFS transport protocol.
 849  *
 850  */
 851 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 852 {
 853         switch (mnt->nfs_server.protocol) {
 854         case XPRT_TRANSPORT_UDP:
 855         case XPRT_TRANSPORT_TCP:
 856         case XPRT_TRANSPORT_RDMA:
 857                 break;
 858         default:
 859                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 860         }
 861 }
 862
 863 /*
 864  * For text based NFSv2/v3 mounts, the mount protocol transport default
 865  * settings should depend upon the specified NFS transport.
 866  */
 867 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 868 {
 869         nfs_validate_transport_protocol(mnt);
 870
 871         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 872             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 873                         return;
 874         switch (mnt->nfs_server.protocol) {
 875         case XPRT_TRANSPORT_UDP:
 876                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 877                 break;
 878         case XPRT_TRANSPORT_TCP:
 879         case XPRT_TRANSPORT_RDMA:
 880                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 881         }
 882 }
 883
 884 /*
 885  * Parse the value of the 'sec=' option.
 886  *
 887  * The flavor_len setting is for v4 mounts.
 888  */
 889 static int nfs_parse_security_flavors(char *value,
 890                                       struct nfs_parsed_mount_data *mnt)
 891 {
 892         substring_t args[MAX_OPT_ARGS];
 893
 894         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 895
 896         switch (match_token(value, nfs_secflavor_tokens, args)) {
 897         case Opt_sec_none:
 898                 mnt->auth_flavor_len = 0;
 899                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 900                 break;
 901         case Opt_sec_sys:
 902                 mnt->auth_flavor_len = 0;
 903                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 904                 break;
 905         case Opt_sec_krb5:
 906                 mnt->auth_flavor_len = 1;
 907                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 908                 break;
 909         case Opt_sec_krb5i:
 910                 mnt->auth_flavor_len = 1;
 911                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 912                 break;
 913         case Opt_sec_krb5p:
 914                 mnt->auth_flavor_len = 1;
 915                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 916                 break;
 917         case Opt_sec_lkey:
 918                 mnt->auth_flavor_len = 1;
 919                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 920                 break;
 921         case Opt_sec_lkeyi:
 922                 mnt->auth_flavor_len = 1;
 923                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 924                 break;
 925         case Opt_sec_lkeyp:
 926                 mnt->auth_flavor_len = 1;
 927                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 928                 break;
 929         case Opt_sec_spkm:
 930                 mnt->auth_flavor_len = 1;
 931                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 932                 break;
 933         case Opt_sec_spkmi:
 934                 mnt->auth_flavor_len = 1;
 935                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 936                 break;
 937         case Opt_sec_spkmp:
 938                 mnt->auth_flavor_len = 1;
 939                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 940                 break;
 941         default:
 942                 return 0;
 943         }
 944
 945         return 1;
 946 }
 947
 948 static void nfs_parse_invalid_value(const char *option)
 949 {
 950         dfprintk(MOUNT, "NFS:   bad value specified for %s option\n", option);
 951 }
 952
 953 /*
 954  * Error-check and convert a string of mount options from user space into
 955  * a data structure.  The whole mount string is processed; bad options are
 956  * skipped as they are encountered.  If there were no errors, return 1;
 957  * otherwise return 0 (zero).
 958  */
 959 static int nfs_parse_mount_options(char *raw,
 960                                    struct nfs_parsed_mount_data *mnt)
 961 {
 962         char *p, *string, *secdata;
 963         int rc, sloppy = 0, errors = 0;
 964
 965         if (!raw) {
 966                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 967                 return 1;
 968         }
 969         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 970
 971         secdata = alloc_secdata();
 972         if (!secdata)
 973                 goto out_nomem;
 974
 975         rc = security_sb_copy_data(raw, secdata);
 976         if (rc)
 977                 goto out_security_failure;
 978
 979         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 980         if (rc)
 981                 goto out_security_failure;
 982
 983         free_secdata(secdata);
 984
 985         while ((p = strsep(&raw, ",")) != NULL) {
 986                 substring_t args[MAX_OPT_ARGS];
 987                 int option, token;
 988
 989                 if (!*p)
 990                         continue;
 991
 992                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 993
 994                 token = match_token(p, nfs_mount_option_tokens, args);
 995                 switch (token) {
 996
 997                 /*
 998                  * boolean options:  foo/nofoo
 999                  */
1000                 case Opt_soft:
1001                         mnt->flags |= NFS_MOUNT_SOFT;
1002                         break;
1003                 case Opt_hard:
1004                         mnt->flags &= ~NFS_MOUNT_SOFT;
1005                         break;
1006                 case Opt_posix:
1007                         mnt->flags |= NFS_MOUNT_POSIX;
1008                         break;
1009                 case Opt_noposix:
1010                         mnt->flags &= ~NFS_MOUNT_POSIX;
1011                         break;
1012                 case Opt_cto:
1013                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1014                         break;
1015                 case Opt_nocto:
1016                         mnt->flags |= NFS_MOUNT_NOCTO;
1017                         break;
1018                 case Opt_ac:
1019                         mnt->flags &= ~NFS_MOUNT_NOAC;
1020                         break;
1021                 case Opt_noac:
1022                         mnt->flags |= NFS_MOUNT_NOAC;
1023                         break;
1024                 case Opt_lock:
1025                         mnt->flags &= ~NFS_MOUNT_NONLM;
1026                         break;
1027                 case Opt_nolock:
1028                         mnt->flags |= NFS_MOUNT_NONLM;
1029                         break;
1030                 case Opt_v2:
1031                         mnt->flags &= ~NFS_MOUNT_VER3;
1032                         break;
1033                 case Opt_v3:
1034                         mnt->flags |= NFS_MOUNT_VER3;
1035                         break;
1036                 case Opt_udp:
1037                         mnt->flags &= ~NFS_MOUNT_TCP;
1038                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1039                         break;
1040                 case Opt_tcp:
1041                         mnt->flags |= NFS_MOUNT_TCP;
1042                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1043                         break;
1044                 case Opt_rdma:
1045                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1046                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1047                         xprt_load_transport(p);
1048                         break;
1049                 case Opt_acl:
1050                         mnt->flags &= ~NFS_MOUNT_NOACL;
1051                         break;
1052                 case Opt_noacl:
1053                         mnt->flags |= NFS_MOUNT_NOACL;
1054                         break;
1055                 case Opt_rdirplus:
1056                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1057                         break;
1058                 case Opt_nordirplus:
1059                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1060                         break;
1061                 case Opt_sharecache:
1062                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1063                         break;
1064                 case Opt_nosharecache:
1065                         mnt->flags |= NFS_MOUNT_UNSHARED;
1066                         break;
1067                 case Opt_resvport:
1068                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1069                         break;
1070                 case Opt_noresvport:
1071                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1072                         break;
1073                 case Opt_fscache:
1074                         mnt->options |= NFS_OPTION_FSCACHE;
1075                         kfree(mnt->fscache_uniq);
1076                         mnt->fscache_uniq = NULL;
1077                         break;
1078                 case Opt_nofscache:
1079                         mnt->options &= ~NFS_OPTION_FSCACHE;
1080                         kfree(mnt->fscache_uniq);
1081                         mnt->fscache_uniq = NULL;
1082                         break;
1083                 case Opt_fscache_uniq:
1084                         string = match_strdup(args);
1085                         if (!string)
1086                                 goto out_nomem;
1087                         kfree(mnt->fscache_uniq);
1088                         mnt->fscache_uniq = string;
1089                         mnt->options |= NFS_OPTION_FSCACHE;
1090                         break;
1091
1092                 /*
1093                  * options that take numeric values
1094                  */
1095                 case Opt_port:
1096                         if (match_int(args, &option) ||
1097                             option < 0 || option > USHORT_MAX) {
1098                                 errors++;
1099                                 nfs_parse_invalid_value("port");
1100                         } else
1101                                 mnt->nfs_server.port = option;
1102                         break;
1103                 case Opt_rsize:
1104                         if (match_int(args, &option) || option < 0) {
1105                                 errors++;
1106                                 nfs_parse_invalid_value("rsize");
1107                         } else
1108                                 mnt->rsize = option;
1109                         break;
1110                 case Opt_wsize:
1111                         if (match_int(args, &option) || option < 0) {
1112                                 errors++;
1113                                 nfs_parse_invalid_value("wsize");
1114                         } else
1115                                 mnt->wsize = option;
1116                         break;
1117                 case Opt_bsize:
1118                         if (match_int(args, &option) || option < 0) {
1119                                 errors++;
1120                                 nfs_parse_invalid_value("bsize");
1121                         } else
1122                                 mnt->bsize = option;
1123                         break;
1124                 case Opt_timeo:
1125                         if (match_int(args, &option) || option <= 0) {
1126                                 errors++;
1127                                 nfs_parse_invalid_value("timeo");
1128                         } else
1129                                 mnt->timeo = option;
1130                         break;
1131                 case Opt_retrans:
1132                         if (match_int(args, &option) || option <= 0) {
1133                                 errors++;
1134                                 nfs_parse_invalid_value("retrans");
1135                         } else
1136                                 mnt->retrans = option;
1137                         break;
1138                 case Opt_acregmin:
1139                         if (match_int(args, &option) || option < 0) {
1140                                 errors++;
1141                                 nfs_parse_invalid_value("acregmin");
1142                         } else
1143                                 mnt->acregmin = option;
1144                         break;
1145                 case Opt_acregmax:
1146                         if (match_int(args, &option) || option < 0) {
1147                                 errors++;
1148                                 nfs_parse_invalid_value("acregmax");
1149                         } else
1150                                 mnt->acregmax = option;
1151                         break;
1152                 case Opt_acdirmin:
1153                         if (match_int(args, &option) || option < 0) {
1154                                 errors++;
1155                                 nfs_parse_invalid_value("acdirmin");
1156                         } else
1157                                 mnt->acdirmin = option;
1158                         break;
1159                 case Opt_acdirmax:
1160                         if (match_int(args, &option) || option < 0) {
1161                                 errors++;
1162                                 nfs_parse_invalid_value("acdirmax");
1163                         } else
1164                                 mnt->acdirmax = option;
1165                         break;
1166                 case Opt_actimeo:
1167                         if (match_int(args, &option) || option < 0) {
1168                                 errors++;
1169                                 nfs_parse_invalid_value("actimeo");
1170                         } else
1171                                 mnt->acregmin = mnt->acregmax =
1172                                 mnt->acdirmin = mnt->acdirmax = option;
1173                         break;
1174                 case Opt_namelen:
1175                         if (match_int(args, &option) || option < 0) {
1176                                 errors++;
1177                                 nfs_parse_invalid_value("namlen");
1178                         } else
1179                                 mnt->namlen = option;
1180                         break;
1181                 case Opt_mountport:
1182                         if (match_int(args, &option) ||
1183                             option < 0 || option > USHORT_MAX) {
1184                                 errors++;
1185                                 nfs_parse_invalid_value("mountport");
1186                         } else
1187                                 mnt->mount_server.port = option;
1188                         break;
1189                 case Opt_mountvers:
1190                         if (match_int(args, &option) ||
1191                             option < NFS_MNT_VERSION ||
1192                             option > NFS_MNT3_VERSION) {
1193                                 errors++;
1194                                 nfs_parse_invalid_value("mountvers");
1195                         } else
1196                                 mnt->mount_server.version = option;
1197                         break;
1198                 case Opt_nfsvers:
1199                         if (match_int(args, &option)) {
1200                                 errors++;
1201                                 nfs_parse_invalid_value("nfsvers");
1202                                 break;
1203                         }
1204                         switch (option) {
1205                         case NFS2_VERSION:
1206                                 mnt->flags &= ~NFS_MOUNT_VER3;
1207                                 break;
1208                         case NFS3_VERSION:
1209                                 mnt->flags |= NFS_MOUNT_VER3;
1210                                 break;
1211                         default:
1212                                 errors++;
1213                                 nfs_parse_invalid_value("nfsvers");
1214                         }
1215                         break;
1216                 case Opt_minorversion:
1217                         if (match_int(args, &option))
1218                                 return 0;
1219                         if (option < 0 || option > NFS4_MAX_MINOR_VERSION)
1220                                 return 0;
1221                         mnt->minorversion = option;
1222                         break;
1223
1224                 /*
1225                  * options that take text values
1226                  */
1227                 case Opt_sec:
1228                         string = match_strdup(args);
1229                         if (string == NULL)
1230                                 goto out_nomem;
1231                         rc = nfs_parse_security_flavors(string, mnt);
1232                         kfree(string);
1233                         if (!rc) {
1234                                 errors++;
1235                                 dfprintk(MOUNT, "NFS:   unrecognized "
1236                                                 "security flavor\n");
1237                         }
1238                         break;
1239                 case Opt_proto:
1240                         string = match_strdup(args);
1241                         if (string == NULL)
1242                                 goto out_nomem;
1243                         token = match_token(string,
1244                                             nfs_xprt_protocol_tokens, args);
1245
1246                         switch (token) {
1247                         case Opt_xprt_udp:
1248                                 mnt->flags &= ~NFS_MOUNT_TCP;
1249                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1250                                 break;
1251                         case Opt_xprt_tcp:
1252                                 mnt->flags |= NFS_MOUNT_TCP;
1253                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1254                                 break;
1255                         case Opt_xprt_rdma:
1256                                 /* vector side protocols to TCP */
1257                                 mnt->flags |= NFS_MOUNT_TCP;
1258                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1259                                 xprt_load_transport(string);
1260                                 break;
1261                         default:
1262                                 errors++;
1263                                 dfprintk(MOUNT, "NFS:   unrecognized "
1264                                                 "transport protocol\n");
1265                         }
1266                         kfree(string);
1267                         break;
1268                 case Opt_mountproto:
1269                         string = match_strdup(args);
1270                         if (string == NULL)
1271                                 goto out_nomem;
1272                         token = match_token(string,
1273                                             nfs_xprt_protocol_tokens, args);
1274                         kfree(string);
1275
1276                         switch (token) {
1277                         case Opt_xprt_udp:
1278                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1279                                 break;
1280                         case Opt_xprt_tcp:
1281                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1282                                 break;
1283                         case Opt_xprt_rdma: /* not used for side protocols */
1284                         default:
1285                                 errors++;
1286                                 dfprintk(MOUNT, "NFS:   unrecognized "
1287                                                 "transport protocol\n");
1288                         }
1289                         break;
1290                 case Opt_addr:
1291                         string = match_strdup(args);
1292                         if (string == NULL)
1293                                 goto out_nomem;
1294                         nfs_parse_ip_address(string, strlen(string),
1295                                              (struct sockaddr *)
1296                                                 &mnt->nfs_server.address,
1297                                              &mnt->nfs_server.addrlen);
1298                         kfree(string);
1299                         break;
1300                 case Opt_clientaddr:
1301                         string = match_strdup(args);
1302                         if (string == NULL)
1303                                 goto out_nomem;
1304                         kfree(mnt->client_address);
1305                         mnt->client_address = string;
1306                         break;
1307                 case Opt_mounthost:
1308                         string = match_strdup(args);
1309                         if (string == NULL)
1310                                 goto out_nomem;
1311                         kfree(mnt->mount_server.hostname);
1312                         mnt->mount_server.hostname = string;
1313                         break;
1314                 case Opt_mountaddr:
1315                         string = match_strdup(args);
1316                         if (string == NULL)
1317                                 goto out_nomem;
1318                         nfs_parse_ip_address(string, strlen(string),
1319                                              (struct sockaddr *)
1320                                                 &mnt->mount_server.address,
1321                                              &mnt->mount_server.addrlen);
1322                         kfree(string);
1323                         break;
1324                 case Opt_lookupcache:
1325                         string = match_strdup(args);
1326                         if (string == NULL)
1327                                 goto out_nomem;
1328                         token = match_token(string,
1329                                         nfs_lookupcache_tokens, args);
1330                         kfree(string);
1331                         switch (token) {
1332                                 case Opt_lookupcache_all:
1333                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1334                                         break;
1335                                 case Opt_lookupcache_positive:
1336                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1337                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1338                                         break;
1339                                 case Opt_lookupcache_none:
1340                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1341                                         break;
1342                                 default:
1343                                         errors++;
1344                                         dfprintk(MOUNT, "NFS:   invalid "
1345                                                         "lookupcache argument\n");
1346                         };
1347                         break;
1348
1349                 /*
1350                  * Special options
1351                  */
1352                 case Opt_sloppy:
1353                         sloppy = 1;
1354                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1355                         break;
1356                 case Opt_userspace:
1357                 case Opt_deprecated:
1358                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1359                                         "'%s'\n", p);
1360                         break;
1361
1362                 default:
1363                         errors++;
1364                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1365                                         "'%s'\n", p);
1366                 }
1367         }
1368
1369         if (errors > 0) {
1370                 dfprintk(MOUNT, "NFS: parsing encountered %d error%s\n",
1371                                 errors, (errors == 1 ? "" : "s"));
1372                 if (!sloppy)
1373                         return 0;
1374         }
1375         return 1;
1376
1377 out_nomem:
1378         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1379         return 0;
1380 out_security_failure:
1381         free_secdata(secdata);
1382         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1383         return 0;
1384 }
1385
1386 /*
1387  * Use the remote server's MOUNT service to request the NFS file handle
1388  * corresponding to the provided path.
1389  */
1390 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1391                          struct nfs_fh *root_fh)
1392 {
1393         struct nfs_mount_request request = {
1394                 .sap            = (struct sockaddr *)
1395                                                 &args->mount_server.address,
1396                 .dirpath        = args->nfs_server.export_path,
1397                 .protocol       = args->mount_server.protocol,
1398                 .fh             = root_fh,
1399                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1400         };
1401         int status;
1402
1403         if (args->mount_server.version == 0) {
1404                 if (args->flags & NFS_MOUNT_VER3)
1405                         args->mount_server.version = NFS_MNT3_VERSION;
1406                 else
1407                         args->mount_server.version = NFS_MNT_VERSION;
1408         }
1409         request.version = args->mount_server.version;
1410
1411         if (args->mount_server.hostname)
1412                 request.hostname = args->mount_server.hostname;
1413         else
1414                 request.hostname = args->nfs_server.hostname;
1415
1416         /*
1417          * Construct the mount server's address.
1418          */
1419         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1420                 memcpy(request.sap, &args->nfs_server.address,
1421                        args->nfs_server.addrlen);
1422                 args->mount_server.addrlen = args->nfs_server.addrlen;
1423         }
1424         request.salen = args->mount_server.addrlen;
1425
1426         /*
1427          * autobind will be used if mount_server.port == 0
1428          */
1429         nfs_set_port(request.sap, args->mount_server.port);
1430
1431         /*
1432          * Now ask the mount server to map our export path
1433          * to a file handle.
1434          */
1435         status = nfs_mount(&request);
1436         if (status == 0)
1437                 return 0;
1438
1439         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1440                         request.hostname, status);
1441         return status;
1442 }
1443
1444 static int nfs_parse_simple_hostname(const char *dev_name,
1445                                      char **hostname, size_t maxnamlen,
1446                                      char **export_path, size_t maxpathlen)
1447 {
1448         size_t len;
1449         char *colon, *comma;
1450
1451         colon = strchr(dev_name, ':');
1452         if (colon == NULL)
1453                 goto out_bad_devname;
1454
1455         len = colon - dev_name;
1456         if (len > maxnamlen)
1457                 goto out_hostname;
1458
1459         /* N.B. caller will free nfs_server.hostname in all cases */
1460         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1461         if (!*hostname)
1462                 goto out_nomem;
1463
1464         /* kill possible hostname list: not supported */
1465         comma = strchr(*hostname, ',');
1466         if (comma != NULL) {
1467                 if (comma == *hostname)
1468                         goto out_bad_devname;
1469                 *comma = '\0';
1470         }
1471
1472         colon++;
1473         len = strlen(colon);
1474         if (len > maxpathlen)
1475                 goto out_path;
1476         *export_path = kstrndup(colon, len, GFP_KERNEL);
1477         if (!*export_path)
1478                 goto out_nomem;
1479
1480         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1481         return 0;
1482
1483 out_bad_devname:
1484         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1485         return -EINVAL;
1486
1487 out_nomem:
1488         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1489         return -ENOMEM;
1490
1491 out_hostname:
1492         dfprintk(MOUNT, "NFS: server hostname too long\n");
1493         return -ENAMETOOLONG;
1494
1495 out_path:
1496         dfprintk(MOUNT, "NFS: export pathname too long\n");
1497         return -ENAMETOOLONG;
1498 }
1499
1500 /*
1501  * Hostname has square brackets around it because it contains one or
1502  * more colons.  We look for the first closing square bracket, and a
1503  * colon must follow it.
1504  */
1505 static int nfs_parse_protected_hostname(const char *dev_name,
1506                                         char **hostname, size_t maxnamlen,
1507                                         char **export_path, size_t maxpathlen)
1508 {
1509         size_t len;
1510         char *start, *end;
1511
1512         start = (char *)(dev_name + 1);
1513
1514         end = strchr(start, ']');
1515         if (end == NULL)
1516                 goto out_bad_devname;
1517         if (*(end + 1) != ':')
1518                 goto out_bad_devname;
1519
1520         len = end - start;
1521         if (len > maxnamlen)
1522                 goto out_hostname;
1523
1524         /* N.B. caller will free nfs_server.hostname in all cases */
1525         *hostname = kstrndup(start, len, GFP_KERNEL);
1526         if (*hostname == NULL)
1527                 goto out_nomem;
1528
1529         end += 2;
1530         len = strlen(end);
1531         if (len > maxpathlen)
1532                 goto out_path;
1533         *export_path = kstrndup(end, len, GFP_KERNEL);
1534         if (!*export_path)
1535                 goto out_nomem;
1536
1537         return 0;
1538
1539 out_bad_devname:
1540         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1541         return -EINVAL;
1542
1543 out_nomem:
1544         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1545         return -ENOMEM;
1546
1547 out_hostname:
1548         dfprintk(MOUNT, "NFS: server hostname too long\n");
1549         return -ENAMETOOLONG;
1550
1551 out_path:
1552         dfprintk(MOUNT, "NFS: export pathname too long\n");
1553         return -ENAMETOOLONG;
1554 }
1555
1556 /*
1557  * Split "dev_name" into "hostname:export_path".
1558  *
1559  * The leftmost colon demarks the split between the server's hostname
1560  * and the export path.  If the hostname starts with a left square
1561  * bracket, then it may contain colons.
1562  *
1563  * Note: caller frees hostname and export path, even on error.
1564  */
1565 static int nfs_parse_devname(const char *dev_name,
1566                              char **hostname, size_t maxnamlen,
1567                              char **export_path, size_t maxpathlen)
1568 {
1569         if (*dev_name == '[')
1570                 return nfs_parse_protected_hostname(dev_name,
1571                                                     hostname, maxnamlen,
1572                                                     export_path, maxpathlen);
1573
1574         return nfs_parse_simple_hostname(dev_name,
1575                                          hostname, maxnamlen,
1576                                          export_path, maxpathlen);
1577 }
1578
1579 /*
1580  * Validate the NFS2/NFS3 mount data
1581  * - fills in the mount root filehandle
1582  *
1583  * For option strings, user space handles the following behaviors:
1584  *
1585  * + DNS: mapping server host name to IP address ("addr=" option)
1586  *
1587  * + failure mode: how to behave if a mount request can't be handled
1588  *   immediately ("fg/bg" option)
1589  *
1590  * + retry: how often to retry a mount request ("retry=" option)
1591  *
1592  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1593  *   mountproto=tcp after mountproto=udp, and so on
1594  */
1595 static int nfs_validate_mount_data(void *options,
1596                                    struct nfs_parsed_mount_data *args,
1597                                    struct nfs_fh *mntfh,
1598                                    const char *dev_name)
1599 {
1600         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1601
1602         if (data == NULL)
1603                 goto out_no_data;
1604
1605         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1606         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1607         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1608         args->acregmin          = NFS_DEF_ACREGMIN;
1609         args->acregmax          = NFS_DEF_ACREGMAX;
1610         args->acdirmin          = NFS_DEF_ACDIRMIN;
1611         args->acdirmax          = NFS_DEF_ACDIRMAX;
1612         args->mount_server.port = 0;    /* autobind unless user sets port */
1613         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1614         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1615         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1616
1617         switch (data->version) {
1618         case 1:
1619                 data->namlen = 0;
1620         case 2:
1621                 data->bsize = 0;
1622         case 3:
1623                 if (data->flags & NFS_MOUNT_VER3)
1624                         goto out_no_v3;
1625                 data->root.size = NFS2_FHSIZE;
1626                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1627         case 4:
1628                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1629                         goto out_no_sec;
1630         case 5:
1631                 memset(data->context, 0, sizeof(data->context));
1632         case 6:
1633                 if (data->flags & NFS_MOUNT_VER3) {
1634                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1635                                 goto out_invalid_fh;
1636                         mntfh->size = data->root.size;
1637                 } else
1638                         mntfh->size = NFS2_FHSIZE;
1639
1640
1641                 memcpy(mntfh->data, data->root.data, mntfh->size);
1642                 if (mntfh->size < sizeof(mntfh->data))
1643                         memset(mntfh->data + mntfh->size, 0,
1644                                sizeof(mntfh->data) - mntfh->size);
1645
1646                 /*
1647                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1648                  * can deal with.
1649                  */
1650                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1651                 args->rsize             = data->rsize;
1652                 args->wsize             = data->wsize;
1653                 args->timeo             = data->timeo;
1654                 args->retrans           = data->retrans;
1655                 args->acregmin          = data->acregmin;
1656                 args->acregmax          = data->acregmax;
1657                 args->acdirmin          = data->acdirmin;
1658                 args->acdirmax          = data->acdirmax;
1659
1660                 memcpy(&args->nfs_server.address, &data->addr,
1661                        sizeof(data->addr));
1662                 args->nfs_server.addrlen = sizeof(data->addr);
1663                 if (!nfs_verify_server_address((struct sockaddr *)
1664                                                 &args->nfs_server.address))
1665                         goto out_no_address;
1666
1667                 if (!(data->flags & NFS_MOUNT_TCP))
1668                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1669                 /* N.B. caller will free nfs_server.hostname in all cases */
1670                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1671                 args->namlen            = data->namlen;
1672                 args->bsize             = data->bsize;
1673
1674                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1675                         args->auth_flavors[0] = data->pseudoflavor;
1676                 if (!args->nfs_server.hostname)
1677                         goto out_nomem;
1678
1679                 /*
1680                  * The legacy version 6 binary mount data from userspace has a
1681                  * field used only to transport selinux information into the
1682                  * the kernel.  To continue to support that functionality we
1683                  * have a touch of selinux knowledge here in the NFS code. The
1684                  * userspace code converted context=blah to just blah so we are
1685                  * converting back to the full string selinux understands.
1686                  */
1687                 if (data->context[0]){
1688 #ifdef CONFIG_SECURITY_SELINUX
1689                         int rc;
1690                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1691                         if (!opts_str)
1692                                 return -ENOMEM;
1693                         strcpy(opts_str, "context=");
1694                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1695                         strcat(opts_str, &data->context[0]);
1696                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1697                         kfree(opts_str);
1698                         if (rc)
1699                                 return rc;
1700 #else
1701                         return -EINVAL;
1702 #endif
1703                 }
1704
1705                 break;
1706         default: {
1707                 int status;
1708
1709                 if (nfs_parse_mount_options((char *)options, args) == 0)
1710                         return -EINVAL;
1711
1712                 if (!nfs_verify_server_address((struct sockaddr *)
1713                                                 &args->nfs_server.address))
1714                         goto out_no_address;
1715
1716                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
1717                                 args->nfs_server.port);
1718
1719                 nfs_set_mount_transport_protocol(args);
1720
1721                 status = nfs_parse_devname(dev_name,
1722                                            &args->nfs_server.hostname,
1723                                            PAGE_SIZE,
1724                                            &args->nfs_server.export_path,
1725                                            NFS_MAXPATHLEN);
1726                 if (!status)
1727                         status = nfs_try_mount(args, mntfh);
1728
1729                 kfree(args->nfs_server.export_path);
1730                 args->nfs_server.export_path = NULL;
1731
1732                 if (status)
1733                         return status;
1734
1735                 break;
1736                 }
1737         }
1738
1739 #ifndef CONFIG_NFS_V3
1740         if (args->flags & NFS_MOUNT_VER3)
1741                 goto out_v3_not_compiled;
1742 #endif /* !CONFIG_NFS_V3 */
1743
1744         return 0;
1745
1746 out_no_data:
1747         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1748         return -EINVAL;
1749
1750 out_no_v3:
1751         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1752                  data->version);
1753         return -EINVAL;
1754
1755 out_no_sec:
1756         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1757         return -EINVAL;
1758
1759 #ifndef CONFIG_NFS_V3
1760 out_v3_not_compiled:
1761         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1762         return -EPROTONOSUPPORT;
1763 #endif /* !CONFIG_NFS_V3 */
1764
1765 out_nomem:
1766         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1767         return -ENOMEM;
1768
1769 out_no_address:
1770         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1771         return -EINVAL;
1772
1773 out_invalid_fh:
1774         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1775         return -EINVAL;
1776 }
1777
1778 static int
1779 nfs_compare_remount_data(struct nfs_server *nfss,
1780                          struct nfs_parsed_mount_data *data)
1781 {
1782         if (data->flags != nfss->flags ||
1783             data->rsize != nfss->rsize ||
1784             data->wsize != nfss->wsize ||
1785             data->retrans != nfss->client->cl_timeout->to_retries ||
1786             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1787             data->acregmin != nfss->acregmin / HZ ||
1788             data->acregmax != nfss->acregmax / HZ ||
1789             data->acdirmin != nfss->acdirmin / HZ ||
1790             data->acdirmax != nfss->acdirmax / HZ ||
1791             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1792             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1793             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1794                    data->nfs_server.addrlen) != 0)
1795                 return -EINVAL;
1796
1797         return 0;
1798 }
1799
1800 static int
1801 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1802 {
1803         int error;
1804         struct nfs_server *nfss = sb->s_fs_info;
1805         struct nfs_parsed_mount_data *data;
1806         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1807         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1808         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1809
1810         /*
1811          * Userspace mount programs that send binary options generally send
1812          * them populated with default values. We have no way to know which
1813          * ones were explicitly specified. Fall back to legacy behavior and
1814          * just return success.
1815          */
1816         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1817             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1818                                            options->version <= 6))))
1819                 return 0;
1820
1821         data = kzalloc(sizeof(*data), GFP_KERNEL);
1822         if (data == NULL)
1823                 return -ENOMEM;
1824
1825         lock_kernel();
1826         /* fill out struct with values from existing mount */
1827         data->flags = nfss->flags;
1828         data->rsize = nfss->rsize;
1829         data->wsize = nfss->wsize;
1830         data->retrans = nfss->client->cl_timeout->to_retries;
1831         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1832         data->acregmin = nfss->acregmin / HZ;
1833         data->acregmax = nfss->acregmax / HZ;
1834         data->acdirmin = nfss->acdirmin / HZ;
1835         data->acdirmax = nfss->acdirmax / HZ;
1836         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1837         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1838         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1839                 data->nfs_server.addrlen);
1840
1841         /* overwrite those values with any that were specified */
1842         error = nfs_parse_mount_options((char *)options, data);
1843         if (error < 0)
1844                 goto out;
1845
1846         /* compare new mount options with old ones */
1847         error = nfs_compare_remount_data(nfss, data);
1848 out:
1849         kfree(data);
1850         unlock_kernel();
1851         return error;
1852 }
1853
1854 /*
1855  * Initialise the common bits of the superblock
1856  */
1857 static inline void nfs_initialise_sb(struct super_block *sb)
1858 {
1859         struct nfs_server *server = NFS_SB(sb);
1860
1861         sb->s_magic = NFS_SUPER_MAGIC;
1862
1863         /* We probably want something more informative here */
1864         snprintf(sb->s_id, sizeof(sb->s_id),
1865                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1866
1867         if (sb->s_blocksize == 0)
1868                 sb->s_blocksize = nfs_block_bits(server->wsize,
1869                                                  &sb->s_blocksize_bits);
1870
1871         if (server->flags & NFS_MOUNT_NOAC)
1872                 sb->s_flags |= MS_SYNCHRONOUS;
1873
1874         nfs_super_set_maxbytes(sb, server->maxfilesize);
1875 }
1876
1877 /*
1878  * Finish setting up an NFS2/3 superblock
1879  */
1880 static void nfs_fill_super(struct super_block *sb,
1881                            struct nfs_parsed_mount_data *data)
1882 {
1883         struct nfs_server *server = NFS_SB(sb);
1884
1885         sb->s_blocksize_bits = 0;
1886         sb->s_blocksize = 0;
1887         if (data->bsize)
1888                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1889
1890         if (server->flags & NFS_MOUNT_VER3) {
1891                 /* The VFS shouldn't apply the umask to mode bits. We will do
1892                  * so ourselves when necessary.
1893                  */
1894                 sb->s_flags |= MS_POSIXACL;
1895                 sb->s_time_gran = 1;
1896         }
1897
1898         sb->s_op = &nfs_sops;
1899         nfs_initialise_sb(sb);
1900 }
1901
1902 /*
1903  * Finish setting up a cloned NFS2/3 superblock
1904  */
1905 static void nfs_clone_super(struct super_block *sb,
1906                             const struct super_block *old_sb)
1907 {
1908         struct nfs_server *server = NFS_SB(sb);
1909
1910         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1911         sb->s_blocksize = old_sb->s_blocksize;
1912         sb->s_maxbytes = old_sb->s_maxbytes;
1913
1914         if (server->flags & NFS_MOUNT_VER3) {
1915                 /* The VFS shouldn't apply the umask to mode bits. We will do
1916                  * so ourselves when necessary.
1917                  */
1918                 sb->s_flags |= MS_POSIXACL;
1919                 sb->s_time_gran = 1;
1920         }
1921
1922         sb->s_op = old_sb->s_op;
1923         nfs_initialise_sb(sb);
1924 }
1925
1926 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1927 {
1928         const struct nfs_server *a = s->s_fs_info;
1929         const struct rpc_clnt *clnt_a = a->client;
1930         const struct rpc_clnt *clnt_b = b->client;
1931
1932         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1933                 goto Ebusy;
1934         if (a->nfs_client != b->nfs_client)
1935                 goto Ebusy;
1936         if (a->flags != b->flags)
1937                 goto Ebusy;
1938         if (a->wsize != b->wsize)
1939                 goto Ebusy;
1940         if (a->rsize != b->rsize)
1941                 goto Ebusy;
1942         if (a->acregmin != b->acregmin)
1943                 goto Ebusy;
1944         if (a->acregmax != b->acregmax)
1945                 goto Ebusy;
1946         if (a->acdirmin != b->acdirmin)
1947                 goto Ebusy;
1948         if (a->acdirmax != b->acdirmax)
1949                 goto Ebusy;
1950         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1951                 goto Ebusy;
1952         return 1;
1953 Ebusy:
1954         return 0;
1955 }
1956
1957 struct nfs_sb_mountdata {
1958         struct nfs_server *server;
1959         int mntflags;
1960 };
1961
1962 static int nfs_set_super(struct super_block *s, void *data)
1963 {
1964         struct nfs_sb_mountdata *sb_mntdata = data;
1965         struct nfs_server *server = sb_mntdata->server;
1966         int ret;
1967
1968         s->s_flags = sb_mntdata->mntflags;
1969         s->s_fs_info = server;
1970         ret = set_anon_super(s, server);
1971         if (ret == 0)
1972                 server->s_dev = s->s_dev;
1973         return ret;
1974 }
1975
1976 static int nfs_compare_super_address(struct nfs_server *server1,
1977                                      struct nfs_server *server2)
1978 {
1979         struct sockaddr *sap1, *sap2;
1980
1981         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1982         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1983
1984         if (sap1->sa_family != sap2->sa_family)
1985                 return 0;
1986
1987         switch (sap1->sa_family) {
1988         case AF_INET: {
1989                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1990                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1991                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1992                         return 0;
1993                 if (sin1->sin_port != sin2->sin_port)
1994                         return 0;
1995                 break;
1996         }
1997         case AF_INET6: {
1998                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1999                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2000                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2001                         return 0;
2002                 if (sin1->sin6_port != sin2->sin6_port)
2003                         return 0;
2004                 break;
2005         }
2006         default:
2007                 return 0;
2008         }
2009
2010         return 1;
2011 }
2012
2013 static int nfs_compare_super(struct super_block *sb, void *data)
2014 {
2015         struct nfs_sb_mountdata *sb_mntdata = data;
2016         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2017         int mntflags = sb_mntdata->mntflags;
2018
2019         if (!nfs_compare_super_address(old, server))
2020                 return 0;
2021         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2022         if (old->flags & NFS_MOUNT_UNSHARED)
2023                 return 0;
2024         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2025                 return 0;
2026         return nfs_compare_mount_options(sb, server, mntflags);
2027 }
2028
2029 static int nfs_bdi_register(struct nfs_server *server)
2030 {
2031         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2032 }
2033
2034 static int nfs_get_sb(struct file_system_type *fs_type,
2035         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2036 {
2037         struct nfs_server *server = NULL;
2038         struct super_block *s;
2039         struct nfs_parsed_mount_data *data;
2040         struct nfs_fh *mntfh;
2041         struct dentry *mntroot;
2042         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2043         struct nfs_sb_mountdata sb_mntdata = {
2044                 .mntflags = flags,
2045         };
2046         int error = -ENOMEM;
2047
2048         data = kzalloc(sizeof(*data), GFP_KERNEL);
2049         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2050         if (data == NULL || mntfh == NULL)
2051                 goto out_free_fh;
2052
2053         security_init_mnt_opts(&data->lsm_opts);
2054
2055         /* Validate the mount data */
2056         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2057         if (error < 0)
2058                 goto out;
2059
2060         /* Get a volume representation */
2061         server = nfs_create_server(data, mntfh);
2062         if (IS_ERR(server)) {
2063                 error = PTR_ERR(server);
2064                 goto out;
2065         }
2066         sb_mntdata.server = server;
2067
2068         if (server->flags & NFS_MOUNT_UNSHARED)
2069                 compare_super = NULL;
2070
2071         /* Get a superblock - note that we may end up sharing one that already exists */
2072         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2073         if (IS_ERR(s)) {
2074                 error = PTR_ERR(s);
2075                 goto out_err_nosb;
2076         }
2077
2078         if (s->s_fs_info != server) {
2079                 nfs_free_server(server);
2080                 server = NULL;
2081         } else {
2082                 error = nfs_bdi_register(server);
2083                 if (error)
2084                         goto error_splat_super;
2085         }
2086
2087         if (!s->s_root) {
2088                 /* initial superblock/root creation */
2089                 nfs_fill_super(s, data);
2090                 nfs_fscache_get_super_cookie(s, data);
2091         }
2092
2093         mntroot = nfs_get_root(s, mntfh);
2094         if (IS_ERR(mntroot)) {
2095                 error = PTR_ERR(mntroot);
2096                 goto error_splat_super;
2097         }
2098
2099         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2100         if (error)
2101                 goto error_splat_root;
2102
2103         s->s_flags |= MS_ACTIVE;
2104         mnt->mnt_sb = s;
2105         mnt->mnt_root = mntroot;
2106         error = 0;
2107
2108 out:
2109         kfree(data->nfs_server.hostname);
2110         kfree(data->mount_server.hostname);
2111         kfree(data->fscache_uniq);
2112         security_free_mnt_opts(&data->lsm_opts);
2113 out_free_fh:
2114         kfree(mntfh);
2115         kfree(data);
2116         return error;
2117
2118 out_err_nosb:
2119         nfs_free_server(server);
2120         goto out;
2121
2122 error_splat_root:
2123         dput(mntroot);
2124 error_splat_super:
2125         deactivate_locked_super(s);
2126         goto out;
2127 }
2128
2129 /*
2130  * Destroy an NFS2/3 superblock
2131  */
2132 static void nfs_kill_super(struct super_block *s)
2133 {
2134         struct nfs_server *server = NFS_SB(s);
2135
2136         bdi_unregister(&server->backing_dev_info);
2137         kill_anon_super(s);
2138         nfs_fscache_release_super_cookie(s);
2139         nfs_free_server(server);
2140 }
2141
2142 /*
2143  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2144  */
2145 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2146                            const char *dev_name, void *raw_data,
2147                            struct vfsmount *mnt)
2148 {
2149         struct nfs_clone_mount *data = raw_data;
2150         struct super_block *s;
2151         struct nfs_server *server;
2152         struct dentry *mntroot;
2153         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2154         struct nfs_sb_mountdata sb_mntdata = {
2155                 .mntflags = flags,
2156         };
2157         int error;
2158
2159         dprintk("--> nfs_xdev_get_sb()\n");
2160
2161         /* create a new volume representation */
2162         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2163         if (IS_ERR(server)) {
2164                 error = PTR_ERR(server);
2165                 goto out_err_noserver;
2166         }
2167         sb_mntdata.server = server;
2168
2169         if (server->flags & NFS_MOUNT_UNSHARED)
2170                 compare_super = NULL;
2171
2172         /* Get a superblock - note that we may end up sharing one that already exists */
2173         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2174         if (IS_ERR(s)) {
2175                 error = PTR_ERR(s);
2176                 goto out_err_nosb;
2177         }
2178
2179         if (s->s_fs_info != server) {
2180                 nfs_free_server(server);
2181                 server = NULL;
2182         } else {
2183                 error = nfs_bdi_register(server);
2184                 if (error)
2185                         goto error_splat_super;
2186         }
2187
2188         if (!s->s_root) {
2189                 /* initial superblock/root creation */
2190                 nfs_clone_super(s, data->sb);
2191         }
2192
2193         mntroot = nfs_get_root(s, data->fh);
2194         if (IS_ERR(mntroot)) {
2195                 error = PTR_ERR(mntroot);
2196                 goto error_splat_super;
2197         }
2198         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2199                 dput(mntroot);
2200                 error = -ESTALE;
2201                 goto error_splat_super;
2202         }
2203
2204         s->s_flags |= MS_ACTIVE;
2205         mnt->mnt_sb = s;
2206         mnt->mnt_root = mntroot;
2207
2208         /* clone any lsm security options from the parent to the new sb */
2209         security_sb_clone_mnt_opts(data->sb, s);
2210
2211         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2212         return 0;
2213
2214 out_err_nosb:
2215         nfs_free_server(server);
2216 out_err_noserver:
2217         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2218         return error;
2219
2220 error_splat_super:
2221         deactivate_locked_super(s);
2222         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2223         return error;
2224 }
2225
2226 #ifdef CONFIG_NFS_V4
2227
2228 /*
2229  * Finish setting up a cloned NFS4 superblock
2230  */
2231 static void nfs4_clone_super(struct super_block *sb,
2232                             const struct super_block *old_sb)
2233 {
2234         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2235         sb->s_blocksize = old_sb->s_blocksize;
2236         sb->s_maxbytes = old_sb->s_maxbytes;
2237         sb->s_time_gran = 1;
2238         sb->s_op = old_sb->s_op;
2239         nfs_initialise_sb(sb);
2240 }
2241
2242 /*
2243  * Set up an NFS4 superblock
2244  */
2245 static void nfs4_fill_super(struct super_block *sb)
2246 {
2247         sb->s_time_gran = 1;
2248         sb->s_op = &nfs4_sops;
2249         nfs_initialise_sb(sb);
2250 }
2251
2252 /*
2253  * Validate NFSv4 mount options
2254  */
2255 static int nfs4_validate_mount_data(void *options,
2256                                     struct nfs_parsed_mount_data *args,
2257                                     const char *dev_name)
2258 {
2259         struct sockaddr_in *ap;
2260         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2261         char *c;
2262
2263         if (data == NULL)
2264                 goto out_no_data;
2265
2266         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2267         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2268         args->acregmin          = NFS_DEF_ACREGMIN;
2269         args->acregmax          = NFS_DEF_ACREGMAX;
2270         args->acdirmin          = NFS_DEF_ACDIRMIN;
2271         args->acdirmax          = NFS_DEF_ACDIRMAX;
2272         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2273         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2274         args->auth_flavor_len   = 0;
2275         args->minorversion      = 0;
2276
2277         switch (data->version) {
2278         case 1:
2279                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2280                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2281                         goto out_no_address;
2282                 if (data->host_addrlen == 0)
2283                         goto out_no_address;
2284                 args->nfs_server.addrlen = data->host_addrlen;
2285                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2286                         return -EFAULT;
2287                 if (!nfs_verify_server_address((struct sockaddr *)
2288                                                 &args->nfs_server.address))
2289                         goto out_no_address;
2290
2291                 if (data->auth_flavourlen) {
2292                         if (data->auth_flavourlen > 1)
2293                                 goto out_inval_auth;
2294                         if (copy_from_user(&args->auth_flavors[0],
2295                                            data->auth_flavours,
2296                                            sizeof(args->auth_flavors[0])))
2297                                 return -EFAULT;
2298                 }
2299
2300                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2301                 if (IS_ERR(c))
2302                         return PTR_ERR(c);
2303                 args->nfs_server.hostname = c;
2304
2305                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2306                 if (IS_ERR(c))
2307                         return PTR_ERR(c);
2308                 args->nfs_server.export_path = c;
2309                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2310
2311                 c = strndup_user(data->client_addr.data, 16);
2312                 if (IS_ERR(c))
2313                         return PTR_ERR(c);
2314                 args->client_address = c;
2315
2316                 /*
2317                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2318                  * can deal with.
2319                  */
2320
2321                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2322                 args->rsize     = data->rsize;
2323                 args->wsize     = data->wsize;
2324                 args->timeo     = data->timeo;
2325                 args->retrans   = data->retrans;
2326                 args->acregmin  = data->acregmin;
2327                 args->acregmax  = data->acregmax;
2328                 args->acdirmin  = data->acdirmin;
2329                 args->acdirmax  = data->acdirmax;
2330                 args->nfs_server.protocol = data->proto;
2331                 nfs_validate_transport_protocol(args);
2332
2333                 break;
2334         default: {
2335                 int status;
2336
2337                 if (nfs_parse_mount_options((char *)options, args) == 0)
2338                         return -EINVAL;
2339
2340                 if (!nfs_verify_server_address((struct sockaddr *)
2341                                                 &args->nfs_server.address))
2342                         return -EINVAL;
2343
2344                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
2345                                 args->nfs_server.port);
2346
2347                 nfs_validate_transport_protocol(args);
2348
2349                 if (args->auth_flavor_len > 1)
2350                         goto out_inval_auth;
2351
2352                 if (args->client_address == NULL)
2353                         goto out_no_client_address;
2354
2355                 status = nfs_parse_devname(dev_name,
2356                                            &args->nfs_server.hostname,
2357                                            NFS4_MAXNAMLEN,
2358                                            &args->nfs_server.export_path,
2359                                            NFS4_MAXPATHLEN);
2360                 if (status < 0)
2361                         return status;
2362
2363                 break;
2364                 }
2365         }
2366
2367         return 0;
2368
2369 out_no_data:
2370         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2371         return -EINVAL;
2372
2373 out_inval_auth:
2374         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2375                  data->auth_flavourlen);
2376         return -EINVAL;
2377
2378 out_no_address:
2379         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2380         return -EINVAL;
2381
2382 out_no_client_address:
2383         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2384         return -EINVAL;
2385 }
2386
2387 /*
2388  * Get the superblock for an NFS4 mountpoint
2389  */
2390 static int nfs4_get_sb(struct file_system_type *fs_type,
2391         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2392 {
2393         struct nfs_parsed_mount_data *data;
2394         struct super_block *s;
2395         struct nfs_server *server;
2396         struct nfs_fh *mntfh;
2397         struct dentry *mntroot;
2398         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2399         struct nfs_sb_mountdata sb_mntdata = {
2400                 .mntflags = flags,
2401         };
2402         int error = -ENOMEM;
2403
2404         data = kzalloc(sizeof(*data), GFP_KERNEL);
2405         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2406         if (data == NULL || mntfh == NULL)
2407                 goto out_free_fh;
2408
2409         security_init_mnt_opts(&data->lsm_opts);
2410
2411         /* Validate the mount data */
2412         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2413         if (error < 0)
2414                 goto out;
2415
2416         /* Get a volume representation */
2417         server = nfs4_create_server(data, mntfh);
2418         if (IS_ERR(server)) {
2419                 error = PTR_ERR(server);
2420                 goto out;
2421         }
2422         sb_mntdata.server = server;
2423
2424         if (server->flags & NFS4_MOUNT_UNSHARED)
2425                 compare_super = NULL;
2426
2427         /* Get a superblock - note that we may end up sharing one that already exists */
2428         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2429         if (IS_ERR(s)) {
2430                 error = PTR_ERR(s);
2431                 goto out_free;
2432         }
2433
2434         if (s->s_fs_info != server) {
2435                 nfs_free_server(server);
2436                 server = NULL;
2437         } else {
2438                 error = nfs_bdi_register(server);
2439                 if (error)
2440                         goto error_splat_super;
2441         }
2442
2443         if (!s->s_root) {
2444                 /* initial superblock/root creation */
2445                 nfs4_fill_super(s);
2446                 nfs_fscache_get_super_cookie(s, data);
2447         }
2448
2449         mntroot = nfs4_get_root(s, mntfh);
2450         if (IS_ERR(mntroot)) {
2451                 error = PTR_ERR(mntroot);
2452                 goto error_splat_super;
2453         }
2454
2455         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2456         if (error)
2457                 goto error_splat_root;
2458
2459         s->s_flags |= MS_ACTIVE;
2460         mnt->mnt_sb = s;
2461         mnt->mnt_root = mntroot;
2462         error = 0;
2463
2464 out:
2465         kfree(data->client_address);
2466         kfree(data->nfs_server.export_path);
2467         kfree(data->nfs_server.hostname);
2468         kfree(data->fscache_uniq);
2469         security_free_mnt_opts(&data->lsm_opts);
2470 out_free_fh:
2471         kfree(mntfh);
2472         kfree(data);
2473         return error;
2474
2475 out_free:
2476         nfs_free_server(server);
2477         goto out;
2478
2479 error_splat_root:
2480         dput(mntroot);
2481 error_splat_super:
2482         deactivate_locked_super(s);
2483         goto out;
2484 }
2485
2486 static void nfs4_kill_super(struct super_block *sb)
2487 {
2488         struct nfs_server *server = NFS_SB(sb);
2489
2490         dprintk("--> %s\n", __func__);
2491         nfs_super_return_all_delegations(sb);
2492         kill_anon_super(sb);
2493         nfs4_renewd_prepare_shutdown(server);
2494         nfs_fscache_release_super_cookie(sb);
2495         nfs_free_server(server);
2496         dprintk("<-- %s\n", __func__);
2497 }
2498
2499 /*
2500  * Clone an NFS4 server record on xdev traversal (FSID-change)
2501  */
2502 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2503                             const char *dev_name, void *raw_data,
2504                             struct vfsmount *mnt)
2505 {
2506         struct nfs_clone_mount *data = raw_data;
2507         struct super_block *s;
2508         struct nfs_server *server;
2509         struct dentry *mntroot;
2510         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2511         struct nfs_sb_mountdata sb_mntdata = {
2512                 .mntflags = flags,
2513         };
2514         int error;
2515
2516         dprintk("--> nfs4_xdev_get_sb()\n");
2517
2518         /* create a new volume representation */
2519         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2520         if (IS_ERR(server)) {
2521                 error = PTR_ERR(server);
2522                 goto out_err_noserver;
2523         }
2524         sb_mntdata.server = server;
2525
2526         if (server->flags & NFS4_MOUNT_UNSHARED)
2527                 compare_super = NULL;
2528
2529         /* Get a superblock - note that we may end up sharing one that already exists */
2530         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2531         if (IS_ERR(s)) {
2532                 error = PTR_ERR(s);
2533                 goto out_err_nosb;
2534         }
2535
2536         if (s->s_fs_info != server) {
2537                 nfs_free_server(server);
2538                 server = NULL;
2539         } else {
2540                 error = nfs_bdi_register(server);
2541                 if (error)
2542                         goto error_splat_super;
2543         }
2544
2545         if (!s->s_root) {
2546                 /* initial superblock/root creation */
2547                 nfs4_clone_super(s, data->sb);
2548         }
2549
2550         mntroot = nfs4_get_root(s, data->fh);
2551         if (IS_ERR(mntroot)) {
2552                 error = PTR_ERR(mntroot);
2553                 goto error_splat_super;
2554         }
2555         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2556                 dput(mntroot);
2557                 error = -ESTALE;
2558                 goto error_splat_super;
2559         }
2560
2561         s->s_flags |= MS_ACTIVE;
2562         mnt->mnt_sb = s;
2563         mnt->mnt_root = mntroot;
2564
2565         security_sb_clone_mnt_opts(data->sb, s);
2566
2567         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2568         return 0;
2569
2570 out_err_nosb:
2571         nfs_free_server(server);
2572 out_err_noserver:
2573         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2574         return error;
2575
2576 error_splat_super:
2577         deactivate_locked_super(s);
2578         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2579         return error;
2580 }
2581
2582 /*
2583  * Create an NFS4 server record on referral traversal
2584  */
2585 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2586                                 const char *dev_name, void *raw_data,
2587                                 struct vfsmount *mnt)
2588 {
2589         struct nfs_clone_mount *data = raw_data;
2590         struct super_block *s;
2591         struct nfs_server *server;
2592         struct dentry *mntroot;
2593         struct nfs_fh mntfh;
2594         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2595         struct nfs_sb_mountdata sb_mntdata = {
2596                 .mntflags = flags,
2597         };
2598         int error;
2599
2600         dprintk("--> nfs4_referral_get_sb()\n");
2601
2602         /* create a new volume representation */
2603         server = nfs4_create_referral_server(data, &mntfh);
2604         if (IS_ERR(server)) {
2605                 error = PTR_ERR(server);
2606                 goto out_err_noserver;
2607         }
2608         sb_mntdata.server = server;
2609
2610         if (server->flags & NFS4_MOUNT_UNSHARED)
2611                 compare_super = NULL;
2612
2613         /* Get a superblock - note that we may end up sharing one that already exists */
2614         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2615         if (IS_ERR(s)) {
2616                 error = PTR_ERR(s);
2617                 goto out_err_nosb;
2618         }
2619
2620         if (s->s_fs_info != server) {
2621                 nfs_free_server(server);
2622                 server = NULL;
2623         } else {
2624                 error = nfs_bdi_register(server);
2625                 if (error)
2626                         goto error_splat_super;
2627         }
2628
2629         if (!s->s_root) {
2630                 /* initial superblock/root creation */
2631                 nfs4_fill_super(s);
2632         }
2633
2634         mntroot = nfs4_get_root(s, &mntfh);
2635         if (IS_ERR(mntroot)) {
2636                 error = PTR_ERR(mntroot);
2637                 goto error_splat_super;
2638         }
2639         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2640                 dput(mntroot);
2641                 error = -ESTALE;
2642                 goto error_splat_super;
2643         }
2644
2645         s->s_flags |= MS_ACTIVE;
2646         mnt->mnt_sb = s;
2647         mnt->mnt_root = mntroot;
2648
2649         security_sb_clone_mnt_opts(data->sb, s);
2650
2651         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2652         return 0;
2653
2654 out_err_nosb:
2655         nfs_free_server(server);
2656 out_err_noserver:
2657         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2658         return error;
2659
2660 error_splat_super:
2661         deactivate_locked_super(s);
2662         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2663         return error;
2664 }
2665
2666 #endif /* CONFIG_NFS_V4 */