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