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