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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.Cox@linux.org>, 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
  79         /* Mount options that take integer arguments */
  80         Opt_port,
  81         Opt_rsize, Opt_wsize, Opt_bsize,
  82         Opt_timeo, Opt_retrans,
  83         Opt_acregmin, Opt_acregmax,
  84         Opt_acdirmin, Opt_acdirmax,
  85         Opt_actimeo,
  86         Opt_namelen,
  87         Opt_mountport,
  88         Opt_mountvers,
  89         Opt_nfsvers,
  90
  91         /* Mount options that take string arguments */
  92         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
  93         Opt_addr, Opt_mountaddr, Opt_clientaddr,
  94
  95         /* Special mount options */
  96         Opt_userspace, Opt_deprecated, Opt_sloppy,
  97
  98         Opt_err
  99 };
 100
 101 static match_table_t nfs_mount_option_tokens = {
 102         { Opt_userspace, "bg" },
 103         { Opt_userspace, "fg" },
 104         { Opt_userspace, "retry=%s" },
 105
 106         { Opt_sloppy, "sloppy" },
 107
 108         { Opt_soft, "soft" },
 109         { Opt_hard, "hard" },
 110         { Opt_deprecated, "intr" },
 111         { Opt_deprecated, "nointr" },
 112         { Opt_posix, "posix" },
 113         { Opt_noposix, "noposix" },
 114         { Opt_cto, "cto" },
 115         { Opt_nocto, "nocto" },
 116         { Opt_ac, "ac" },
 117         { Opt_noac, "noac" },
 118         { Opt_lock, "lock" },
 119         { Opt_nolock, "nolock" },
 120         { Opt_v2, "v2" },
 121         { Opt_v3, "v3" },
 122         { Opt_udp, "udp" },
 123         { Opt_tcp, "tcp" },
 124         { Opt_rdma, "rdma" },
 125         { Opt_acl, "acl" },
 126         { Opt_noacl, "noacl" },
 127         { Opt_rdirplus, "rdirplus" },
 128         { Opt_nordirplus, "nordirplus" },
 129         { Opt_sharecache, "sharecache" },
 130         { Opt_nosharecache, "nosharecache" },
 131
 132         { Opt_port, "port=%u" },
 133         { Opt_rsize, "rsize=%u" },
 134         { Opt_wsize, "wsize=%u" },
 135         { Opt_bsize, "bsize=%u" },
 136         { Opt_timeo, "timeo=%u" },
 137         { Opt_retrans, "retrans=%u" },
 138         { Opt_acregmin, "acregmin=%u" },
 139         { Opt_acregmax, "acregmax=%u" },
 140         { Opt_acdirmin, "acdirmin=%u" },
 141         { Opt_acdirmax, "acdirmax=%u" },
 142         { Opt_actimeo, "actimeo=%u" },
 143         { Opt_namelen, "namlen=%u" },
 144         { Opt_mountport, "mountport=%u" },
 145         { Opt_mountvers, "mountvers=%u" },
 146         { Opt_nfsvers, "nfsvers=%u" },
 147         { Opt_nfsvers, "vers=%u" },
 148
 149         { Opt_sec, "sec=%s" },
 150         { Opt_proto, "proto=%s" },
 151         { Opt_mountproto, "mountproto=%s" },
 152         { Opt_addr, "addr=%s" },
 153         { Opt_clientaddr, "clientaddr=%s" },
 154         { Opt_mounthost, "mounthost=%s" },
 155         { Opt_mountaddr, "mountaddr=%s" },
 156
 157         { Opt_err, NULL }
 158 };
 159
 160 enum {
 161         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 162
 163         Opt_xprt_err
 164 };
 165
 166 static match_table_t nfs_xprt_protocol_tokens = {
 167         { Opt_xprt_udp, "udp" },
 168         { Opt_xprt_tcp, "tcp" },
 169         { Opt_xprt_rdma, "rdma" },
 170
 171         { Opt_xprt_err, NULL }
 172 };
 173
 174 enum {
 175         Opt_sec_none, Opt_sec_sys,
 176         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 177         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 178         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 179
 180         Opt_sec_err
 181 };
 182
 183 static match_table_t nfs_secflavor_tokens = {
 184         { Opt_sec_none, "none" },
 185         { Opt_sec_none, "null" },
 186         { Opt_sec_sys, "sys" },
 187
 188         { Opt_sec_krb5, "krb5" },
 189         { Opt_sec_krb5i, "krb5i" },
 190         { Opt_sec_krb5p, "krb5p" },
 191
 192         { Opt_sec_lkey, "lkey" },
 193         { Opt_sec_lkeyi, "lkeyi" },
 194         { Opt_sec_lkeyp, "lkeyp" },
 195
 196         { Opt_sec_spkm, "spkm3" },
 197         { Opt_sec_spkmi, "spkm3i" },
 198         { Opt_sec_spkmp, "spkm3p" },
 199
 200         { Opt_sec_err, NULL }
 201 };
 202
 203
 204 static void nfs_umount_begin(struct super_block *);
 205 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 206 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 207 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 208 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 209 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 210                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 211 static void nfs_kill_super(struct super_block *);
 212 static void nfs_put_super(struct super_block *);
 213 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 214
 215 static struct file_system_type nfs_fs_type = {
 216         .owner          = THIS_MODULE,
 217         .name           = "nfs",
 218         .get_sb         = nfs_get_sb,
 219         .kill_sb        = nfs_kill_super,
 220         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 221 };
 222
 223 struct file_system_type nfs_xdev_fs_type = {
 224         .owner          = THIS_MODULE,
 225         .name           = "nfs",
 226         .get_sb         = nfs_xdev_get_sb,
 227         .kill_sb        = nfs_kill_super,
 228         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 229 };
 230
 231 static const struct super_operations nfs_sops = {
 232         .alloc_inode    = nfs_alloc_inode,
 233         .destroy_inode  = nfs_destroy_inode,
 234         .write_inode    = nfs_write_inode,
 235         .put_super      = nfs_put_super,
 236         .statfs         = nfs_statfs,
 237         .clear_inode    = nfs_clear_inode,
 238         .umount_begin   = nfs_umount_begin,
 239         .show_options   = nfs_show_options,
 240         .show_stats     = nfs_show_stats,
 241         .remount_fs     = nfs_remount,
 242 };
 243
 244 #ifdef CONFIG_NFS_V4
 245 static int nfs4_get_sb(struct file_system_type *fs_type,
 246         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 247 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 248         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 249 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 250         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 251 static void nfs4_kill_super(struct super_block *sb);
 252
 253 static struct file_system_type nfs4_fs_type = {
 254         .owner          = THIS_MODULE,
 255         .name           = "nfs4",
 256         .get_sb         = nfs4_get_sb,
 257         .kill_sb        = nfs4_kill_super,
 258         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 259 };
 260
 261 struct file_system_type nfs4_xdev_fs_type = {
 262         .owner          = THIS_MODULE,
 263         .name           = "nfs4",
 264         .get_sb         = nfs4_xdev_get_sb,
 265         .kill_sb        = nfs4_kill_super,
 266         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 267 };
 268
 269 struct file_system_type nfs4_referral_fs_type = {
 270         .owner          = THIS_MODULE,
 271         .name           = "nfs4",
 272         .get_sb         = nfs4_referral_get_sb,
 273         .kill_sb        = nfs4_kill_super,
 274         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 275 };
 276
 277 static const struct super_operations nfs4_sops = {
 278         .alloc_inode    = nfs_alloc_inode,
 279         .destroy_inode  = nfs_destroy_inode,
 280         .write_inode    = nfs_write_inode,
 281         .statfs         = nfs_statfs,
 282         .clear_inode    = nfs4_clear_inode,
 283         .umount_begin   = nfs_umount_begin,
 284         .show_options   = nfs_show_options,
 285         .show_stats     = nfs_show_stats,
 286         .remount_fs     = nfs_remount,
 287 };
 288 #endif
 289
 290 static struct shrinker acl_shrinker = {
 291         .shrink         = nfs_access_cache_shrinker,
 292         .seeks          = DEFAULT_SEEKS,
 293 };
 294
 295 /*
 296  * Register the NFS filesystems
 297  */
 298 int __init register_nfs_fs(void)
 299 {
 300         int ret;
 301
 302         ret = register_filesystem(&nfs_fs_type);
 303         if (ret < 0)
 304                 goto error_0;
 305
 306         ret = nfs_register_sysctl();
 307         if (ret < 0)
 308                 goto error_1;
 309 #ifdef CONFIG_NFS_V4
 310         ret = register_filesystem(&nfs4_fs_type);
 311         if (ret < 0)
 312                 goto error_2;
 313 #endif
 314         register_shrinker(&acl_shrinker);
 315         return 0;
 316
 317 #ifdef CONFIG_NFS_V4
 318 error_2:
 319         nfs_unregister_sysctl();
 320 #endif
 321 error_1:
 322         unregister_filesystem(&nfs_fs_type);
 323 error_0:
 324         return ret;
 325 }
 326
 327 /*
 328  * Unregister the NFS filesystems
 329  */
 330 void __exit unregister_nfs_fs(void)
 331 {
 332         unregister_shrinker(&acl_shrinker);
 333 #ifdef CONFIG_NFS_V4
 334         unregister_filesystem(&nfs4_fs_type);
 335 #endif
 336         nfs_unregister_sysctl();
 337         unregister_filesystem(&nfs_fs_type);
 338 }
 339
 340 void nfs_sb_active(struct nfs_server *server)
 341 {
 342         atomic_inc(&server->active);
 343 }
 344
 345 void nfs_sb_deactive(struct nfs_server *server)
 346 {
 347         if (atomic_dec_and_test(&server->active))
 348                 wake_up(&server->active_wq);
 349 }
 350
 351 static void nfs_put_super(struct super_block *sb)
 352 {
 353         struct nfs_server *server = NFS_SB(sb);
 354         /*
 355          * Make sure there are no outstanding ops to this server.
 356          * If so, wait for them to finish before allowing the
 357          * unmount to continue.
 358          */
 359         wait_event(server->active_wq, atomic_read(&server->active) == 0);
 360 }
 361
 362 /*
 363  * Deliver file system statistics to userspace
 364  */
 365 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 366 {
 367         struct nfs_server *server = NFS_SB(dentry->d_sb);
 368         unsigned char blockbits;
 369         unsigned long blockres;
 370         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 371         struct nfs_fattr fattr;
 372         struct nfs_fsstat res = {
 373                         .fattr = &fattr,
 374         };
 375         int error;
 376
 377         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 378         if (error < 0)
 379                 goto out_err;
 380         buf->f_type = NFS_SUPER_MAGIC;
 381
 382         /*
 383          * Current versions of glibc do not correctly handle the
 384          * case where f_frsize != f_bsize.  Eventually we want to
 385          * report the value of wtmult in this field.
 386          */
 387         buf->f_frsize = dentry->d_sb->s_blocksize;
 388
 389         /*
 390          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 391          * are reported in units of f_frsize.  Linux hasn't had
 392          * an f_frsize field in its statfs struct until recently,
 393          * thus historically Linux's sys_statfs reports these
 394          * fields in units of f_bsize.
 395          */
 396         buf->f_bsize = dentry->d_sb->s_blocksize;
 397         blockbits = dentry->d_sb->s_blocksize_bits;
 398         blockres = (1 << blockbits) - 1;
 399         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 400         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 401         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 402
 403         buf->f_files = res.tfiles;
 404         buf->f_ffree = res.afiles;
 405
 406         buf->f_namelen = server->namelen;
 407
 408         return 0;
 409
 410  out_err:
 411         dprintk("%s: statfs error = %d\n", __func__, -error);
 412         return error;
 413 }
 414
 415 /*
 416  * Map the security flavour number to a name
 417  */
 418 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 419 {
 420         static const struct {
 421                 rpc_authflavor_t flavour;
 422                 const char *str;
 423         } sec_flavours[] = {
 424                 { RPC_AUTH_NULL, "null" },
 425                 { RPC_AUTH_UNIX, "sys" },
 426                 { RPC_AUTH_GSS_KRB5, "krb5" },
 427                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 428                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 429                 { RPC_AUTH_GSS_LKEY, "lkey" },
 430                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 431                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 432                 { RPC_AUTH_GSS_SPKM, "spkm" },
 433                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 434                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 435                 { UINT_MAX, "unknown" }
 436         };
 437         int i;
 438
 439         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 440                 if (sec_flavours[i].flavour == flavour)
 441                         break;
 442         }
 443         return sec_flavours[i].str;
 444 }
 445
 446 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 447                                     int showdefaults)
 448 {
 449         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 450
 451         switch (sap->sa_family) {
 452         case AF_INET: {
 453                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 454                 seq_printf(m, ",mountaddr=" NIPQUAD_FMT,
 455                                 NIPQUAD(sin->sin_addr.s_addr));
 456                 break;
 457         }
 458         case AF_INET6: {
 459                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 460                 seq_printf(m, ",mountaddr=" NIP6_FMT,
 461                                 NIP6(sin6->sin6_addr));
 462                 break;
 463         }
 464         default:
 465                 if (showdefaults)
 466                         seq_printf(m, ",mountaddr=unspecified");
 467         }
 468
 469         if (nfss->mountd_version || showdefaults)
 470                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 471         if (nfss->mountd_port || showdefaults)
 472                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 473
 474         switch (nfss->mountd_protocol) {
 475         case IPPROTO_UDP:
 476                 seq_printf(m, ",mountproto=udp");
 477                 break;
 478         case IPPROTO_TCP:
 479                 seq_printf(m, ",mountproto=tcp");
 480                 break;
 481         default:
 482                 if (showdefaults)
 483                         seq_printf(m, ",mountproto=auto");
 484         }
 485 }
 486
 487 /*
 488  * Describe the mount options in force on this server representation
 489  */
 490 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 491                                    int showdefaults)
 492 {
 493         static const struct proc_nfs_info {
 494                 int flag;
 495                 const char *str;
 496                 const char *nostr;
 497         } nfs_info[] = {
 498                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 499                 { NFS_MOUNT_INTR, ",intr", ",nointr" },
 500                 { NFS_MOUNT_POSIX, ",posix", "" },
 501                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 502                 { NFS_MOUNT_NOAC, ",noac", "" },
 503                 { NFS_MOUNT_NONLM, ",nolock", "" },
 504                 { NFS_MOUNT_NOACL, ",noacl", "" },
 505                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 506                 { NFS_MOUNT_UNSHARED, ",nosharecache", ""},
 507                 { 0, NULL, NULL }
 508         };
 509         const struct proc_nfs_info *nfs_infop;
 510         struct nfs_client *clp = nfss->nfs_client;
 511         u32 version = clp->rpc_ops->version;
 512
 513         seq_printf(m, ",vers=%u", version);
 514         seq_printf(m, ",rsize=%u", nfss->rsize);
 515         seq_printf(m, ",wsize=%u", nfss->wsize);
 516         if (nfss->bsize != 0)
 517                 seq_printf(m, ",bsize=%u", nfss->bsize);
 518         seq_printf(m, ",namlen=%u", nfss->namelen);
 519         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 520                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 521         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 522                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 523         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 524                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 525         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 526                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 527         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 528                 if (nfss->flags & nfs_infop->flag)
 529                         seq_puts(m, nfs_infop->str);
 530                 else
 531                         seq_puts(m, nfs_infop->nostr);
 532         }
 533         seq_printf(m, ",proto=%s",
 534                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 535         if (version == 4) {
 536                 if (nfss->port != NFS_PORT)
 537                         seq_printf(m, ",port=%u", nfss->port);
 538         } else
 539                 if (nfss->port)
 540                         seq_printf(m, ",port=%u", nfss->port);
 541
 542         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 543         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 544         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 545
 546         if (version != 4)
 547                 nfs_show_mountd_options(m, nfss, showdefaults);
 548
 549 #ifdef CONFIG_NFS_V4
 550         if (clp->rpc_ops->version == 4)
 551                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 552 #endif
 553 }
 554
 555 /*
 556  * Describe the mount options on this VFS mountpoint
 557  */
 558 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 559 {
 560         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 561
 562         nfs_show_mount_options(m, nfss, 0);
 563
 564         seq_printf(m, ",addr=%s",
 565                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 566                                                         RPC_DISPLAY_ADDR));
 567
 568         return 0;
 569 }
 570
 571 /*
 572  * Present statistical information for this VFS mountpoint
 573  */
 574 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 575 {
 576         int i, cpu;
 577         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 578         struct rpc_auth *auth = nfss->client->cl_auth;
 579         struct nfs_iostats totals = { };
 580
 581         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 582
 583         /*
 584          * Display all mount option settings
 585          */
 586         seq_printf(m, "\n\topts:\t");
 587         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 588         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 589         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 590         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 591         nfs_show_mount_options(m, nfss, 1);
 592
 593         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 594
 595         seq_printf(m, "\n\tcaps:\t");
 596         seq_printf(m, "caps=0x%x", nfss->caps);
 597         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 598         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 599         seq_printf(m, ",bsize=%u", nfss->bsize);
 600         seq_printf(m, ",namlen=%u", nfss->namelen);
 601
 602 #ifdef CONFIG_NFS_V4
 603         if (nfss->nfs_client->rpc_ops->version == 4) {
 604                 seq_printf(m, "\n\tnfsv4:\t");
 605                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 606                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 607                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 608         }
 609 #endif
 610
 611         /*
 612          * Display security flavor in effect for this mount
 613          */
 614         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 615         if (auth->au_flavor)
 616                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 617
 618         /*
 619          * Display superblock I/O counters
 620          */
 621         for_each_possible_cpu(cpu) {
 622                 struct nfs_iostats *stats;
 623
 624                 preempt_disable();
 625                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 626
 627                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 628                         totals.events[i] += stats->events[i];
 629                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 630                         totals.bytes[i] += stats->bytes[i];
 631
 632                 preempt_enable();
 633         }
 634
 635         seq_printf(m, "\n\tevents:\t");
 636         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 637                 seq_printf(m, "%lu ", totals.events[i]);
 638         seq_printf(m, "\n\tbytes:\t");
 639         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 640                 seq_printf(m, "%Lu ", totals.bytes[i]);
 641         seq_printf(m, "\n");
 642
 643         rpc_print_iostats(m, nfss->client);
 644
 645         return 0;
 646 }
 647
 648 /*
 649  * Begin unmount by attempting to remove all automounted mountpoints we added
 650  * in response to xdev traversals and referrals
 651  */
 652 static void nfs_umount_begin(struct super_block *sb)
 653 {
 654         struct nfs_server *server = NFS_SB(sb);
 655         struct rpc_clnt *rpc;
 656
 657         /* -EIO all pending I/O */
 658         rpc = server->client_acl;
 659         if (!IS_ERR(rpc))
 660                 rpc_killall_tasks(rpc);
 661         rpc = server->client;
 662         if (!IS_ERR(rpc))
 663                 rpc_killall_tasks(rpc);
 664 }
 665
 666 /*
 667  * Set the port number in an address.  Be agnostic about the address family.
 668  */
 669 static void nfs_set_port(struct sockaddr *sap, unsigned short port)
 670 {
 671         switch (sap->sa_family) {
 672         case AF_INET: {
 673                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
 674                 ap->sin_port = htons(port);
 675                 break;
 676         }
 677         case AF_INET6: {
 678                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
 679                 ap->sin6_port = htons(port);
 680                 break;
 681         }
 682         }
 683 }
 684
 685 /*
 686  * Sanity-check a server address provided by the mount command.
 687  *
 688  * Address family must be initialized, and address must not be
 689  * the ANY address for that family.
 690  */
 691 static int nfs_verify_server_address(struct sockaddr *addr)
 692 {
 693         switch (addr->sa_family) {
 694         case AF_INET: {
 695                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 696                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 697         }
 698         case AF_INET6: {
 699                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 700                 return !ipv6_addr_any(sa);
 701         }
 702         }
 703
 704         return 0;
 705 }
 706
 707 static void nfs_parse_ipv4_address(char *string, size_t str_len,
 708                                    struct sockaddr *sap, size_t *addr_len)
 709 {
 710         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 711         u8 *addr = (u8 *)&sin->sin_addr.s_addr;
 712
 713         if (str_len <= INET_ADDRSTRLEN) {
 714                 dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
 715                                 (int)str_len, string);
 716
 717                 sin->sin_family = AF_INET;
 718                 *addr_len = sizeof(*sin);
 719                 if (in4_pton(string, str_len, addr, '\0', NULL))
 720                         return;
 721         }
 722
 723         sap->sa_family = AF_UNSPEC;
 724         *addr_len = 0;
 725 }
 726
 727 #define IPV6_SCOPE_DELIMITER    '%'
 728
 729 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 730 static void nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
 731                                     const char *delim,
 732                                     struct sockaddr_in6 *sin6)
 733 {
 734         char *p;
 735         size_t len;
 736
 737         if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
 738                 return ;
 739         if (*delim != IPV6_SCOPE_DELIMITER)
 740                 return;
 741
 742         len = (string + str_len) - delim - 1;
 743         p = kstrndup(delim + 1, len, GFP_KERNEL);
 744         if (p) {
 745                 unsigned long scope_id = 0;
 746                 struct net_device *dev;
 747
 748                 dev = dev_get_by_name(&init_net, p);
 749                 if (dev != NULL) {
 750                         scope_id = dev->ifindex;
 751                         dev_put(dev);
 752                 } else {
 753                         /* scope_id is set to zero on error */
 754                         strict_strtoul(p, 10, &scope_id);
 755                 }
 756
 757                 kfree(p);
 758                 sin6->sin6_scope_id = scope_id;
 759                 dfprintk(MOUNT, "NFS: IPv6 scope ID = %lu\n", scope_id);
 760         }
 761 }
 762
 763 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 764                                    struct sockaddr *sap, size_t *addr_len)
 765 {
 766         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 767         u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
 768         const char *delim;
 769
 770         if (str_len <= INET6_ADDRSTRLEN) {
 771                 dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
 772                                 (int)str_len, string);
 773
 774                 sin6->sin6_family = AF_INET6;
 775                 *addr_len = sizeof(*sin6);
 776                 if (in6_pton(string, str_len, addr, IPV6_SCOPE_DELIMITER, &delim)) {
 777                         nfs_parse_ipv6_scope_id(string, str_len, delim, sin6);
 778                         return;
 779                 }
 780         }
 781
 782         sap->sa_family = AF_UNSPEC;
 783         *addr_len = 0;
 784 }
 785 #else
 786 static void nfs_parse_ipv6_address(char *string, size_t str_len,
 787                                    struct sockaddr *sap, size_t *addr_len)
 788 {
 789         sap->sa_family = AF_UNSPEC;
 790         *addr_len = 0;
 791 }
 792 #endif
 793
 794 /*
 795  * Construct a sockaddr based on the contents of a string that contains
 796  * an IP address in presentation format.
 797  *
 798  * If there is a problem constructing the new sockaddr, set the address
 799  * family to AF_UNSPEC.
 800  */
 801 static void nfs_parse_ip_address(char *string, size_t str_len,
 802                                  struct sockaddr *sap, size_t *addr_len)
 803 {
 804         unsigned int i, colons;
 805
 806         colons = 0;
 807         for (i = 0; i < str_len; i++)
 808                 if (string[i] == ':')
 809                         colons++;
 810
 811         if (colons >= 2)
 812                 nfs_parse_ipv6_address(string, str_len, sap, addr_len);
 813         else
 814                 nfs_parse_ipv4_address(string, str_len, sap, addr_len);
 815 }
 816
 817 /*
 818  * Sanity check the NFS transport protocol.
 819  *
 820  */
 821 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 822 {
 823         switch (mnt->nfs_server.protocol) {
 824         case XPRT_TRANSPORT_UDP:
 825         case XPRT_TRANSPORT_TCP:
 826         case XPRT_TRANSPORT_RDMA:
 827                 break;
 828         default:
 829                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 830         }
 831 }
 832
 833 /*
 834  * For text based NFSv2/v3 mounts, the mount protocol transport default
 835  * settings should depend upon the specified NFS transport.
 836  */
 837 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 838 {
 839         nfs_validate_transport_protocol(mnt);
 840
 841         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 842             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 843                         return;
 844         switch (mnt->nfs_server.protocol) {
 845         case XPRT_TRANSPORT_UDP:
 846                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 847                 break;
 848         case XPRT_TRANSPORT_TCP:
 849         case XPRT_TRANSPORT_RDMA:
 850                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 851         }
 852 }
 853
 854 /*
 855  * Parse the value of the 'sec=' option.
 856  *
 857  * The flavor_len setting is for v4 mounts.
 858  */
 859 static int nfs_parse_security_flavors(char *value,
 860                                       struct nfs_parsed_mount_data *mnt)
 861 {
 862         substring_t args[MAX_OPT_ARGS];
 863
 864         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 865
 866         switch (match_token(value, nfs_secflavor_tokens, args)) {
 867         case Opt_sec_none:
 868                 mnt->auth_flavor_len = 0;
 869                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 870                 break;
 871         case Opt_sec_sys:
 872                 mnt->auth_flavor_len = 0;
 873                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 874                 break;
 875         case Opt_sec_krb5:
 876                 mnt->auth_flavor_len = 1;
 877                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 878                 break;
 879         case Opt_sec_krb5i:
 880                 mnt->auth_flavor_len = 1;
 881                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 882                 break;
 883         case Opt_sec_krb5p:
 884                 mnt->auth_flavor_len = 1;
 885                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 886                 break;
 887         case Opt_sec_lkey:
 888                 mnt->auth_flavor_len = 1;
 889                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 890                 break;
 891         case Opt_sec_lkeyi:
 892                 mnt->auth_flavor_len = 1;
 893                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 894                 break;
 895         case Opt_sec_lkeyp:
 896                 mnt->auth_flavor_len = 1;
 897                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 898                 break;
 899         case Opt_sec_spkm:
 900                 mnt->auth_flavor_len = 1;
 901                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 902                 break;
 903         case Opt_sec_spkmi:
 904                 mnt->auth_flavor_len = 1;
 905                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 906                 break;
 907         case Opt_sec_spkmp:
 908                 mnt->auth_flavor_len = 1;
 909                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 910                 break;
 911         default:
 912                 return 0;
 913         }
 914
 915         return 1;
 916 }
 917
 918 static void nfs_parse_invalid_value(const char *option)
 919 {
 920         dfprintk(MOUNT, "NFS:   bad value specified for %s option\n", option);
 921 }
 922
 923 /*
 924  * Error-check and convert a string of mount options from user space into
 925  * a data structure.  The whole mount string is processed; bad options are
 926  * skipped as they are encountered.  If there were no errors, return 1;
 927  * otherwise return 0 (zero).
 928  */
 929 static int nfs_parse_mount_options(char *raw,
 930                                    struct nfs_parsed_mount_data *mnt)
 931 {
 932         char *p, *string, *secdata;
 933         int rc, sloppy = 0, errors = 0;
 934
 935         if (!raw) {
 936                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 937                 return 1;
 938         }
 939         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 940
 941         secdata = alloc_secdata();
 942         if (!secdata)
 943                 goto out_nomem;
 944
 945         rc = security_sb_copy_data(raw, secdata);
 946         if (rc)
 947                 goto out_security_failure;
 948
 949         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 950         if (rc)
 951                 goto out_security_failure;
 952
 953         free_secdata(secdata);
 954
 955         while ((p = strsep(&raw, ",")) != NULL) {
 956                 substring_t args[MAX_OPT_ARGS];
 957                 int option, token;
 958
 959                 if (!*p)
 960                         continue;
 961
 962                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 963
 964                 token = match_token(p, nfs_mount_option_tokens, args);
 965                 switch (token) {
 966
 967                 /*
 968                  * boolean options:  foo/nofoo
 969                  */
 970                 case Opt_soft:
 971                         mnt->flags |= NFS_MOUNT_SOFT;
 972                         break;
 973                 case Opt_hard:
 974                         mnt->flags &= ~NFS_MOUNT_SOFT;
 975                         break;
 976                 case Opt_posix:
 977                         mnt->flags |= NFS_MOUNT_POSIX;
 978                         break;
 979                 case Opt_noposix:
 980                         mnt->flags &= ~NFS_MOUNT_POSIX;
 981                         break;
 982                 case Opt_cto:
 983                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 984                         break;
 985                 case Opt_nocto:
 986                         mnt->flags |= NFS_MOUNT_NOCTO;
 987                         break;
 988                 case Opt_ac:
 989                         mnt->flags &= ~NFS_MOUNT_NOAC;
 990                         break;
 991                 case Opt_noac:
 992                         mnt->flags |= NFS_MOUNT_NOAC;
 993                         break;
 994                 case Opt_lock:
 995                         mnt->flags &= ~NFS_MOUNT_NONLM;
 996                         break;
 997                 case Opt_nolock:
 998                         mnt->flags |= NFS_MOUNT_NONLM;
 999                         break;
1000                 case Opt_v2:
1001                         mnt->flags &= ~NFS_MOUNT_VER3;
1002                         break;
1003                 case Opt_v3:
1004                         mnt->flags |= NFS_MOUNT_VER3;
1005                         break;
1006                 case Opt_udp:
1007                         mnt->flags &= ~NFS_MOUNT_TCP;
1008                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1009                         break;
1010                 case Opt_tcp:
1011                         mnt->flags |= NFS_MOUNT_TCP;
1012                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1013                         break;
1014                 case Opt_rdma:
1015                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1016                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1017                         break;
1018                 case Opt_acl:
1019                         mnt->flags &= ~NFS_MOUNT_NOACL;
1020                         break;
1021                 case Opt_noacl:
1022                         mnt->flags |= NFS_MOUNT_NOACL;
1023                         break;
1024                 case Opt_rdirplus:
1025                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1026                         break;
1027                 case Opt_nordirplus:
1028                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1029                         break;
1030                 case Opt_sharecache:
1031                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1032                         break;
1033                 case Opt_nosharecache:
1034                         mnt->flags |= NFS_MOUNT_UNSHARED;
1035                         break;
1036
1037                 /*
1038                  * options that take numeric values
1039                  */
1040                 case Opt_port:
1041                         if (match_int(args, &option) ||
1042                             option < 0 || option > USHORT_MAX) {
1043                                 errors++;
1044                                 nfs_parse_invalid_value("port");
1045                         } else
1046                                 mnt->nfs_server.port = option;
1047                         break;
1048                 case Opt_rsize:
1049                         if (match_int(args, &option) || option < 0) {
1050                                 errors++;
1051                                 nfs_parse_invalid_value("rsize");
1052                         } else
1053                                 mnt->rsize = option;
1054                         break;
1055                 case Opt_wsize:
1056                         if (match_int(args, &option) || option < 0) {
1057                                 errors++;
1058                                 nfs_parse_invalid_value("wsize");
1059                         } else
1060                                 mnt->wsize = option;
1061                         break;
1062                 case Opt_bsize:
1063                         if (match_int(args, &option) || option < 0) {
1064                                 errors++;
1065                                 nfs_parse_invalid_value("bsize");
1066                         } else
1067                                 mnt->bsize = option;
1068                         break;
1069                 case Opt_timeo:
1070                         if (match_int(args, &option) || option <= 0) {
1071                                 errors++;
1072                                 nfs_parse_invalid_value("timeo");
1073                         } else
1074                                 mnt->timeo = option;
1075                         break;
1076                 case Opt_retrans:
1077                         if (match_int(args, &option) || option <= 0) {
1078                                 errors++;
1079                                 nfs_parse_invalid_value("retrans");
1080                         } else
1081                                 mnt->retrans = option;
1082                         break;
1083                 case Opt_acregmin:
1084                         if (match_int(args, &option) || option < 0) {
1085                                 errors++;
1086                                 nfs_parse_invalid_value("acregmin");
1087                         } else
1088                                 mnt->acregmin = option;
1089                         break;
1090                 case Opt_acregmax:
1091                         if (match_int(args, &option) || option < 0) {
1092                                 errors++;
1093                                 nfs_parse_invalid_value("acregmax");
1094                         } else
1095                                 mnt->acregmax = option;
1096                         break;
1097                 case Opt_acdirmin:
1098                         if (match_int(args, &option) || option < 0) {
1099                                 errors++;
1100                                 nfs_parse_invalid_value("acdirmin");
1101                         } else
1102                                 mnt->acdirmin = option;
1103                         break;
1104                 case Opt_acdirmax:
1105                         if (match_int(args, &option) || option < 0) {
1106                                 errors++;
1107                                 nfs_parse_invalid_value("acdirmax");
1108                         } else
1109                                 mnt->acdirmax = option;
1110                         break;
1111                 case Opt_actimeo:
1112                         if (match_int(args, &option) || option < 0) {
1113                                 errors++;
1114                                 nfs_parse_invalid_value("actimeo");
1115                         } else
1116                                 mnt->acregmin = mnt->acregmax =
1117                                 mnt->acdirmin = mnt->acdirmax = option;
1118                         break;
1119                 case Opt_namelen:
1120                         if (match_int(args, &option) || option < 0) {
1121                                 errors++;
1122                                 nfs_parse_invalid_value("namlen");
1123                         } else
1124                                 mnt->namlen = option;
1125                         break;
1126                 case Opt_mountport:
1127                         if (match_int(args, &option) ||
1128                             option < 0 || option > USHORT_MAX) {
1129                                 errors++;
1130                                 nfs_parse_invalid_value("mountport");
1131                         } else
1132                                 mnt->mount_server.port = option;
1133                         break;
1134                 case Opt_mountvers:
1135                         if (match_int(args, &option) ||
1136                             option < NFS_MNT_VERSION ||
1137                             option > NFS_MNT3_VERSION) {
1138                                 errors++;
1139                                 nfs_parse_invalid_value("mountvers");
1140                         } else
1141                                 mnt->mount_server.version = option;
1142                         break;
1143                 case Opt_nfsvers:
1144                         if (match_int(args, &option)) {
1145                                 errors++;
1146                                 nfs_parse_invalid_value("nfsvers");
1147                                 break;
1148                         }
1149                         switch (option) {
1150                         case NFS2_VERSION:
1151                                 mnt->flags &= ~NFS_MOUNT_VER3;
1152                                 break;
1153                         case NFS3_VERSION:
1154                                 mnt->flags |= NFS_MOUNT_VER3;
1155                                 break;
1156                         default:
1157                                 errors++;
1158                                 nfs_parse_invalid_value("nfsvers");
1159                         }
1160                         break;
1161
1162                 /*
1163                  * options that take text values
1164                  */
1165                 case Opt_sec:
1166                         string = match_strdup(args);
1167                         if (string == NULL)
1168                                 goto out_nomem;
1169                         rc = nfs_parse_security_flavors(string, mnt);
1170                         kfree(string);
1171                         if (!rc) {
1172                                 errors++;
1173                                 dfprintk(MOUNT, "NFS:   unrecognized "
1174                                                 "security flavor\n");
1175                         }
1176                         break;
1177                 case Opt_proto:
1178                         string = match_strdup(args);
1179                         if (string == NULL)
1180                                 goto out_nomem;
1181                         token = match_token(string,
1182                                             nfs_xprt_protocol_tokens, args);
1183                         kfree(string);
1184
1185                         switch (token) {
1186                         case Opt_xprt_udp:
1187                                 mnt->flags &= ~NFS_MOUNT_TCP;
1188                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1189                                 break;
1190                         case Opt_xprt_tcp:
1191                                 mnt->flags |= NFS_MOUNT_TCP;
1192                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1193                                 break;
1194                         case Opt_xprt_rdma:
1195                                 /* vector side protocols to TCP */
1196                                 mnt->flags |= NFS_MOUNT_TCP;
1197                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1198                                 break;
1199                         default:
1200                                 errors++;
1201                                 dfprintk(MOUNT, "NFS:   unrecognized "
1202                                                 "transport protocol\n");
1203                         }
1204                         break;
1205                 case Opt_mountproto:
1206                         string = match_strdup(args);
1207                         if (string == NULL)
1208                                 goto out_nomem;
1209                         token = match_token(string,
1210                                             nfs_xprt_protocol_tokens, args);
1211                         kfree(string);
1212
1213                         switch (token) {
1214                         case Opt_xprt_udp:
1215                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1216                                 break;
1217                         case Opt_xprt_tcp:
1218                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1219                                 break;
1220                         case Opt_xprt_rdma: /* not used for side protocols */
1221                         default:
1222                                 errors++;
1223                                 dfprintk(MOUNT, "NFS:   unrecognized "
1224                                                 "transport protocol\n");
1225                         }
1226                         break;
1227                 case Opt_addr:
1228                         string = match_strdup(args);
1229                         if (string == NULL)
1230                                 goto out_nomem;
1231                         nfs_parse_ip_address(string, strlen(string),
1232                                              (struct sockaddr *)
1233                                                 &mnt->nfs_server.address,
1234                                              &mnt->nfs_server.addrlen);
1235                         kfree(string);
1236                         break;
1237                 case Opt_clientaddr:
1238                         string = match_strdup(args);
1239                         if (string == NULL)
1240                                 goto out_nomem;
1241                         kfree(mnt->client_address);
1242                         mnt->client_address = string;
1243                         break;
1244                 case Opt_mounthost:
1245                         string = match_strdup(args);
1246                         if (string == NULL)
1247                                 goto out_nomem;
1248                         kfree(mnt->mount_server.hostname);
1249                         mnt->mount_server.hostname = string;
1250                         break;
1251                 case Opt_mountaddr:
1252                         string = match_strdup(args);
1253                         if (string == NULL)
1254                                 goto out_nomem;
1255                         nfs_parse_ip_address(string, strlen(string),
1256                                              (struct sockaddr *)
1257                                                 &mnt->mount_server.address,
1258                                              &mnt->mount_server.addrlen);
1259                         kfree(string);
1260                         break;
1261
1262                 /*
1263                  * Special options
1264                  */
1265                 case Opt_sloppy:
1266                         sloppy = 1;
1267                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1268                         break;
1269                 case Opt_userspace:
1270                 case Opt_deprecated:
1271                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1272                                         "'%s'\n", p);
1273                         break;
1274
1275                 default:
1276                         errors++;
1277                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1278                                         "'%s'\n", p);
1279                 }
1280         }
1281
1282         return 1;
1283
1284 out_nomem:
1285         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1286         return 0;
1287 out_security_failure:
1288         free_secdata(secdata);
1289         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1290         return 0;
1291 }
1292
1293 /*
1294  * Use the remote server's MOUNT service to request the NFS file handle
1295  * corresponding to the provided path.
1296  */
1297 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1298                          struct nfs_fh *root_fh)
1299 {
1300         struct sockaddr *sap = (struct sockaddr *)&args->mount_server.address;
1301         char *hostname;
1302         int status;
1303
1304         if (args->mount_server.version == 0) {
1305                 if (args->flags & NFS_MOUNT_VER3)
1306                         args->mount_server.version = NFS_MNT3_VERSION;
1307                 else
1308                         args->mount_server.version = NFS_MNT_VERSION;
1309         }
1310
1311         if (args->mount_server.hostname)
1312                 hostname = args->mount_server.hostname;
1313         else
1314                 hostname = args->nfs_server.hostname;
1315
1316         /*
1317          * Construct the mount server's address.
1318          */
1319         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1320                 memcpy(sap, &args->nfs_server.address,
1321                        args->nfs_server.addrlen);
1322                 args->mount_server.addrlen = args->nfs_server.addrlen;
1323         }
1324
1325         /*
1326          * autobind will be used if mount_server.port == 0
1327          */
1328         nfs_set_port(sap, args->mount_server.port);
1329
1330         /*
1331          * Now ask the mount server to map our export path
1332          * to a file handle.
1333          */
1334         status = nfs_mount(sap,
1335                            args->mount_server.addrlen,
1336                            hostname,
1337                            args->nfs_server.export_path,
1338                            args->mount_server.version,
1339                            args->mount_server.protocol,
1340                            root_fh);
1341         if (status == 0)
1342                 return 0;
1343
1344         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1345                         hostname, status);
1346         return status;
1347 }
1348
1349 static int nfs_parse_simple_hostname(const char *dev_name,
1350                                      char **hostname, size_t maxnamlen,
1351                                      char **export_path, size_t maxpathlen)
1352 {
1353         size_t len;
1354         char *colon, *comma;
1355
1356         colon = strchr(dev_name, ':');
1357         if (colon == NULL)
1358                 goto out_bad_devname;
1359
1360         len = colon - dev_name;
1361         if (len > maxnamlen)
1362                 goto out_hostname;
1363
1364         /* N.B. caller will free nfs_server.hostname in all cases */
1365         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1366         if (!*hostname)
1367                 goto out_nomem;
1368
1369         /* kill possible hostname list: not supported */
1370         comma = strchr(*hostname, ',');
1371         if (comma != NULL) {
1372                 if (comma == *hostname)
1373                         goto out_bad_devname;
1374                 *comma = '\0';
1375         }
1376
1377         colon++;
1378         len = strlen(colon);
1379         if (len > maxpathlen)
1380                 goto out_path;
1381         *export_path = kstrndup(colon, len, GFP_KERNEL);
1382         if (!*export_path)
1383                 goto out_nomem;
1384
1385         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1386         return 0;
1387
1388 out_bad_devname:
1389         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1390         return -EINVAL;
1391
1392 out_nomem:
1393         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1394         return -ENOMEM;
1395
1396 out_hostname:
1397         dfprintk(MOUNT, "NFS: server hostname too long\n");
1398         return -ENAMETOOLONG;
1399
1400 out_path:
1401         dfprintk(MOUNT, "NFS: export pathname too long\n");
1402         return -ENAMETOOLONG;
1403 }
1404
1405 /*
1406  * Hostname has square brackets around it because it contains one or
1407  * more colons.  We look for the first closing square bracket, and a
1408  * colon must follow it.
1409  */
1410 static int nfs_parse_protected_hostname(const char *dev_name,
1411                                         char **hostname, size_t maxnamlen,
1412                                         char **export_path, size_t maxpathlen)
1413 {
1414         size_t len;
1415         char *start, *end;
1416
1417         start = (char *)(dev_name + 1);
1418
1419         end = strchr(start, ']');
1420         if (end == NULL)
1421                 goto out_bad_devname;
1422         if (*(end + 1) != ':')
1423                 goto out_bad_devname;
1424
1425         len = end - start;
1426         if (len > maxnamlen)
1427                 goto out_hostname;
1428
1429         /* N.B. caller will free nfs_server.hostname in all cases */
1430         *hostname = kstrndup(start, len, GFP_KERNEL);
1431         if (*hostname == NULL)
1432                 goto out_nomem;
1433
1434         end += 2;
1435         len = strlen(end);
1436         if (len > maxpathlen)
1437                 goto out_path;
1438         *export_path = kstrndup(end, len, GFP_KERNEL);
1439         if (!*export_path)
1440                 goto out_nomem;
1441
1442         return 0;
1443
1444 out_bad_devname:
1445         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1446         return -EINVAL;
1447
1448 out_nomem:
1449         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1450         return -ENOMEM;
1451
1452 out_hostname:
1453         dfprintk(MOUNT, "NFS: server hostname too long\n");
1454         return -ENAMETOOLONG;
1455
1456 out_path:
1457         dfprintk(MOUNT, "NFS: export pathname too long\n");
1458         return -ENAMETOOLONG;
1459 }
1460
1461 /*
1462  * Split "dev_name" into "hostname:export_path".
1463  *
1464  * The leftmost colon demarks the split between the server's hostname
1465  * and the export path.  If the hostname starts with a left square
1466  * bracket, then it may contain colons.
1467  *
1468  * Note: caller frees hostname and export path, even on error.
1469  */
1470 static int nfs_parse_devname(const char *dev_name,
1471                              char **hostname, size_t maxnamlen,
1472                              char **export_path, size_t maxpathlen)
1473 {
1474         if (*dev_name == '[')
1475                 return nfs_parse_protected_hostname(dev_name,
1476                                                     hostname, maxnamlen,
1477                                                     export_path, maxpathlen);
1478
1479         return nfs_parse_simple_hostname(dev_name,
1480                                          hostname, maxnamlen,
1481                                          export_path, maxpathlen);
1482 }
1483
1484 /*
1485  * Validate the NFS2/NFS3 mount data
1486  * - fills in the mount root filehandle
1487  *
1488  * For option strings, user space handles the following behaviors:
1489  *
1490  * + DNS: mapping server host name to IP address ("addr=" option)
1491  *
1492  * + failure mode: how to behave if a mount request can't be handled
1493  *   immediately ("fg/bg" option)
1494  *
1495  * + retry: how often to retry a mount request ("retry=" option)
1496  *
1497  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1498  *   mountproto=tcp after mountproto=udp, and so on
1499  */
1500 static int nfs_validate_mount_data(void *options,
1501                                    struct nfs_parsed_mount_data *args,
1502                                    struct nfs_fh *mntfh,
1503                                    const char *dev_name)
1504 {
1505         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1506
1507         if (data == NULL)
1508                 goto out_no_data;
1509
1510         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1511         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1512         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1513         args->acregmin          = NFS_DEF_ACREGMIN;
1514         args->acregmax          = NFS_DEF_ACREGMAX;
1515         args->acdirmin          = NFS_DEF_ACDIRMIN;
1516         args->acdirmax          = NFS_DEF_ACDIRMAX;
1517         args->mount_server.port = 0;    /* autobind unless user sets port */
1518         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1519         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1520         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1521
1522         switch (data->version) {
1523         case 1:
1524                 data->namlen = 0;
1525         case 2:
1526                 data->bsize = 0;
1527         case 3:
1528                 if (data->flags & NFS_MOUNT_VER3)
1529                         goto out_no_v3;
1530                 data->root.size = NFS2_FHSIZE;
1531                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1532         case 4:
1533                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1534                         goto out_no_sec;
1535         case 5:
1536                 memset(data->context, 0, sizeof(data->context));
1537         case 6:
1538                 if (data->flags & NFS_MOUNT_VER3) {
1539                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1540                                 goto out_invalid_fh;
1541                         mntfh->size = data->root.size;
1542                 } else
1543                         mntfh->size = NFS2_FHSIZE;
1544
1545
1546                 memcpy(mntfh->data, data->root.data, mntfh->size);
1547                 if (mntfh->size < sizeof(mntfh->data))
1548                         memset(mntfh->data + mntfh->size, 0,
1549                                sizeof(mntfh->data) - mntfh->size);
1550
1551                 /*
1552                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1553                  * can deal with.
1554                  */
1555                 args->flags             = data->flags;
1556                 args->rsize             = data->rsize;
1557                 args->wsize             = data->wsize;
1558                 args->timeo             = data->timeo;
1559                 args->retrans           = data->retrans;
1560                 args->acregmin          = data->acregmin;
1561                 args->acregmax          = data->acregmax;
1562                 args->acdirmin          = data->acdirmin;
1563                 args->acdirmax          = data->acdirmax;
1564
1565                 memcpy(&args->nfs_server.address, &data->addr,
1566                        sizeof(data->addr));
1567                 args->nfs_server.addrlen = sizeof(data->addr);
1568                 if (!nfs_verify_server_address((struct sockaddr *)
1569                                                 &args->nfs_server.address))
1570                         goto out_no_address;
1571
1572                 if (!(data->flags & NFS_MOUNT_TCP))
1573                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1574                 /* N.B. caller will free nfs_server.hostname in all cases */
1575                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1576                 args->namlen            = data->namlen;
1577                 args->bsize             = data->bsize;
1578
1579                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1580                         args->auth_flavors[0] = data->pseudoflavor;
1581                 if (!args->nfs_server.hostname)
1582                         goto out_nomem;
1583
1584                 /*
1585                  * The legacy version 6 binary mount data from userspace has a
1586                  * field used only to transport selinux information into the
1587                  * the kernel.  To continue to support that functionality we
1588                  * have a touch of selinux knowledge here in the NFS code. The
1589                  * userspace code converted context=blah to just blah so we are
1590                  * converting back to the full string selinux understands.
1591                  */
1592                 if (data->context[0]){
1593 #ifdef CONFIG_SECURITY_SELINUX
1594                         int rc;
1595                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1596                         if (!opts_str)
1597                                 return -ENOMEM;
1598                         strcpy(opts_str, "context=");
1599                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1600                         strcat(opts_str, &data->context[0]);
1601                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1602                         kfree(opts_str);
1603                         if (rc)
1604                                 return rc;
1605 #else
1606                         return -EINVAL;
1607 #endif
1608                 }
1609
1610                 break;
1611         default: {
1612                 int status;
1613
1614                 if (nfs_parse_mount_options((char *)options, args) == 0)
1615                         return -EINVAL;
1616
1617                 if (!nfs_verify_server_address((struct sockaddr *)
1618                                                 &args->nfs_server.address))
1619                         goto out_no_address;
1620
1621                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
1622                                 args->nfs_server.port);
1623
1624                 nfs_set_mount_transport_protocol(args);
1625
1626                 status = nfs_parse_devname(dev_name,
1627                                            &args->nfs_server.hostname,
1628                                            PAGE_SIZE,
1629                                            &args->nfs_server.export_path,
1630                                            NFS_MAXPATHLEN);
1631                 if (!status)
1632                         status = nfs_try_mount(args, mntfh);
1633
1634                 kfree(args->nfs_server.export_path);
1635                 args->nfs_server.export_path = NULL;
1636
1637                 if (status)
1638                         return status;
1639
1640                 break;
1641                 }
1642         }
1643
1644 #ifndef CONFIG_NFS_V3
1645         if (args->flags & NFS_MOUNT_VER3)
1646                 goto out_v3_not_compiled;
1647 #endif /* !CONFIG_NFS_V3 */
1648
1649         return 0;
1650
1651 out_no_data:
1652         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1653         return -EINVAL;
1654
1655 out_no_v3:
1656         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1657                  data->version);
1658         return -EINVAL;
1659
1660 out_no_sec:
1661         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1662         return -EINVAL;
1663
1664 #ifndef CONFIG_NFS_V3
1665 out_v3_not_compiled:
1666         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1667         return -EPROTONOSUPPORT;
1668 #endif /* !CONFIG_NFS_V3 */
1669
1670 out_nomem:
1671         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1672         return -ENOMEM;
1673
1674 out_no_address:
1675         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1676         return -EINVAL;
1677
1678 out_invalid_fh:
1679         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1680         return -EINVAL;
1681 }
1682
1683 static int
1684 nfs_compare_remount_data(struct nfs_server *nfss,
1685                          struct nfs_parsed_mount_data *data)
1686 {
1687         if (data->flags != nfss->flags ||
1688             data->rsize != nfss->rsize ||
1689             data->wsize != nfss->wsize ||
1690             data->retrans != nfss->client->cl_timeout->to_retries ||
1691             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1692             data->acregmin != nfss->acregmin / HZ ||
1693             data->acregmax != nfss->acregmax / HZ ||
1694             data->acdirmin != nfss->acdirmin / HZ ||
1695             data->acdirmax != nfss->acdirmax / HZ ||
1696             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1697             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1698             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1699                    data->nfs_server.addrlen) != 0)
1700                 return -EINVAL;
1701
1702         return 0;
1703 }
1704
1705 static int
1706 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1707 {
1708         int error;
1709         struct nfs_server *nfss = sb->s_fs_info;
1710         struct nfs_parsed_mount_data *data;
1711         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1712         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1713         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1714
1715         /*
1716          * Userspace mount programs that send binary options generally send
1717          * them populated with default values. We have no way to know which
1718          * ones were explicitly specified. Fall back to legacy behavior and
1719          * just return success.
1720          */
1721         if ((nfsvers == 4 && options4->version == 1) ||
1722             (nfsvers <= 3 && options->version >= 1 &&
1723              options->version <= 6))
1724                 return 0;
1725
1726         data = kzalloc(sizeof(*data), GFP_KERNEL);
1727         if (data == NULL)
1728                 return -ENOMEM;
1729
1730         /* fill out struct with values from existing mount */
1731         data->flags = nfss->flags;
1732         data->rsize = nfss->rsize;
1733         data->wsize = nfss->wsize;
1734         data->retrans = nfss->client->cl_timeout->to_retries;
1735         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1736         data->acregmin = nfss->acregmin / HZ;
1737         data->acregmax = nfss->acregmax / HZ;
1738         data->acdirmin = nfss->acdirmin / HZ;
1739         data->acdirmax = nfss->acdirmax / HZ;
1740         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1741         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1742         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1743                 data->nfs_server.addrlen);
1744
1745         /* overwrite those values with any that were specified */
1746         error = nfs_parse_mount_options((char *)options, data);
1747         if (error < 0)
1748                 goto out;
1749
1750         /* compare new mount options with old ones */
1751         error = nfs_compare_remount_data(nfss, data);
1752 out:
1753         kfree(data);
1754         return error;
1755 }
1756
1757 /*
1758  * Initialise the common bits of the superblock
1759  */
1760 static inline void nfs_initialise_sb(struct super_block *sb)
1761 {
1762         struct nfs_server *server = NFS_SB(sb);
1763
1764         sb->s_magic = NFS_SUPER_MAGIC;
1765
1766         /* We probably want something more informative here */
1767         snprintf(sb->s_id, sizeof(sb->s_id),
1768                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1769
1770         if (sb->s_blocksize == 0)
1771                 sb->s_blocksize = nfs_block_bits(server->wsize,
1772                                                  &sb->s_blocksize_bits);
1773
1774         if (server->flags & NFS_MOUNT_NOAC)
1775                 sb->s_flags |= MS_SYNCHRONOUS;
1776
1777         nfs_super_set_maxbytes(sb, server->maxfilesize);
1778 }
1779
1780 /*
1781  * Finish setting up an NFS2/3 superblock
1782  */
1783 static void nfs_fill_super(struct super_block *sb,
1784                            struct nfs_parsed_mount_data *data)
1785 {
1786         struct nfs_server *server = NFS_SB(sb);
1787
1788         sb->s_blocksize_bits = 0;
1789         sb->s_blocksize = 0;
1790         if (data->bsize)
1791                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1792
1793         if (server->flags & NFS_MOUNT_VER3) {
1794                 /* The VFS shouldn't apply the umask to mode bits. We will do
1795                  * so ourselves when necessary.
1796                  */
1797                 sb->s_flags |= MS_POSIXACL;
1798                 sb->s_time_gran = 1;
1799         }
1800
1801         sb->s_op = &nfs_sops;
1802         nfs_initialise_sb(sb);
1803 }
1804
1805 /*
1806  * Finish setting up a cloned NFS2/3 superblock
1807  */
1808 static void nfs_clone_super(struct super_block *sb,
1809                             const struct super_block *old_sb)
1810 {
1811         struct nfs_server *server = NFS_SB(sb);
1812
1813         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1814         sb->s_blocksize = old_sb->s_blocksize;
1815         sb->s_maxbytes = old_sb->s_maxbytes;
1816
1817         if (server->flags & NFS_MOUNT_VER3) {
1818                 /* The VFS shouldn't apply the umask to mode bits. We will do
1819                  * so ourselves when necessary.
1820                  */
1821                 sb->s_flags |= MS_POSIXACL;
1822                 sb->s_time_gran = 1;
1823         }
1824
1825         sb->s_op = old_sb->s_op;
1826         nfs_initialise_sb(sb);
1827 }
1828
1829 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
1830
1831 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1832 {
1833         const struct nfs_server *a = s->s_fs_info;
1834         const struct rpc_clnt *clnt_a = a->client;
1835         const struct rpc_clnt *clnt_b = b->client;
1836
1837         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1838                 goto Ebusy;
1839         if (a->nfs_client != b->nfs_client)
1840                 goto Ebusy;
1841         if (a->flags != b->flags)
1842                 goto Ebusy;
1843         if (a->wsize != b->wsize)
1844                 goto Ebusy;
1845         if (a->rsize != b->rsize)
1846                 goto Ebusy;
1847         if (a->acregmin != b->acregmin)
1848                 goto Ebusy;
1849         if (a->acregmax != b->acregmax)
1850                 goto Ebusy;
1851         if (a->acdirmin != b->acdirmin)
1852                 goto Ebusy;
1853         if (a->acdirmax != b->acdirmax)
1854                 goto Ebusy;
1855         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1856                 goto Ebusy;
1857         return 1;
1858 Ebusy:
1859         return 0;
1860 }
1861
1862 struct nfs_sb_mountdata {
1863         struct nfs_server *server;
1864         int mntflags;
1865 };
1866
1867 static int nfs_set_super(struct super_block *s, void *data)
1868 {
1869         struct nfs_sb_mountdata *sb_mntdata = data;
1870         struct nfs_server *server = sb_mntdata->server;
1871         int ret;
1872
1873         s->s_flags = sb_mntdata->mntflags;
1874         s->s_fs_info = server;
1875         ret = set_anon_super(s, server);
1876         if (ret == 0)
1877                 server->s_dev = s->s_dev;
1878         return ret;
1879 }
1880
1881 static int nfs_compare_super_address(struct nfs_server *server1,
1882                                      struct nfs_server *server2)
1883 {
1884         struct sockaddr *sap1, *sap2;
1885
1886         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1887         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1888
1889         if (sap1->sa_family != sap2->sa_family)
1890                 return 0;
1891
1892         switch (sap1->sa_family) {
1893         case AF_INET: {
1894                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1895                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1896                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1897                         return 0;
1898                 if (sin1->sin_port != sin2->sin_port)
1899                         return 0;
1900                 break;
1901         }
1902         case AF_INET6: {
1903                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1904                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1905                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1906                         return 0;
1907                 if (sin1->sin6_port != sin2->sin6_port)
1908                         return 0;
1909                 break;
1910         }
1911         default:
1912                 return 0;
1913         }
1914
1915         return 1;
1916 }
1917
1918 static int nfs_compare_super(struct super_block *sb, void *data)
1919 {
1920         struct nfs_sb_mountdata *sb_mntdata = data;
1921         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1922         int mntflags = sb_mntdata->mntflags;
1923
1924         if (!nfs_compare_super_address(old, server))
1925                 return 0;
1926         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1927         if (old->flags & NFS_MOUNT_UNSHARED)
1928                 return 0;
1929         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1930                 return 0;
1931         return nfs_compare_mount_options(sb, server, mntflags);
1932 }
1933
1934 static int nfs_bdi_register(struct nfs_server *server)
1935 {
1936         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
1937 }
1938
1939 static int nfs_get_sb(struct file_system_type *fs_type,
1940         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1941 {
1942         struct nfs_server *server = NULL;
1943         struct super_block *s;
1944         struct nfs_parsed_mount_data *data;
1945         struct nfs_fh *mntfh;
1946         struct dentry *mntroot;
1947         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1948         struct nfs_sb_mountdata sb_mntdata = {
1949                 .mntflags = flags,
1950         };
1951         int error = -ENOMEM;
1952
1953         data = kzalloc(sizeof(*data), GFP_KERNEL);
1954         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
1955         if (data == NULL || mntfh == NULL)
1956                 goto out_free_fh;
1957
1958         security_init_mnt_opts(&data->lsm_opts);
1959
1960         /* Validate the mount data */
1961         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
1962         if (error < 0)
1963                 goto out;
1964
1965         /* Get a volume representation */
1966         server = nfs_create_server(data, mntfh);
1967         if (IS_ERR(server)) {
1968                 error = PTR_ERR(server);
1969                 goto out;
1970         }
1971         sb_mntdata.server = server;
1972
1973         if (server->flags & NFS_MOUNT_UNSHARED)
1974                 compare_super = NULL;
1975
1976         /* Get a superblock - note that we may end up sharing one that already exists */
1977         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1978         if (IS_ERR(s)) {
1979                 error = PTR_ERR(s);
1980                 goto out_err_nosb;
1981         }
1982
1983         if (s->s_fs_info != server) {
1984                 nfs_free_server(server);
1985                 server = NULL;
1986         } else {
1987                 error = nfs_bdi_register(server);
1988                 if (error)
1989                         goto error_splat_super;
1990         }
1991
1992         if (!s->s_root) {
1993                 /* initial superblock/root creation */
1994                 nfs_fill_super(s, data);
1995         }
1996
1997         mntroot = nfs_get_root(s, mntfh);
1998         if (IS_ERR(mntroot)) {
1999                 error = PTR_ERR(mntroot);
2000                 goto error_splat_super;
2001         }
2002
2003         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2004         if (error)
2005                 goto error_splat_root;
2006
2007         s->s_flags |= MS_ACTIVE;
2008         mnt->mnt_sb = s;
2009         mnt->mnt_root = mntroot;
2010         error = 0;
2011
2012 out:
2013         kfree(data->nfs_server.hostname);
2014         kfree(data->mount_server.hostname);
2015         security_free_mnt_opts(&data->lsm_opts);
2016 out_free_fh:
2017         kfree(mntfh);
2018         kfree(data);
2019         return error;
2020
2021 out_err_nosb:
2022         nfs_free_server(server);
2023         goto out;
2024
2025 error_splat_root:
2026         dput(mntroot);
2027 error_splat_super:
2028         up_write(&s->s_umount);
2029         deactivate_super(s);
2030         goto out;
2031 }
2032
2033 /*
2034  * Destroy an NFS2/3 superblock
2035  */
2036 static void nfs_kill_super(struct super_block *s)
2037 {
2038         struct nfs_server *server = NFS_SB(s);
2039
2040         bdi_unregister(&server->backing_dev_info);
2041         kill_anon_super(s);
2042         nfs_free_server(server);
2043 }
2044
2045 /*
2046  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2047  */
2048 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2049                            const char *dev_name, void *raw_data,
2050                            struct vfsmount *mnt)
2051 {
2052         struct nfs_clone_mount *data = raw_data;
2053         struct super_block *s;
2054         struct nfs_server *server;
2055         struct dentry *mntroot;
2056         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2057         struct nfs_sb_mountdata sb_mntdata = {
2058                 .mntflags = flags,
2059         };
2060         int error;
2061
2062         dprintk("--> nfs_xdev_get_sb()\n");
2063
2064         /* create a new volume representation */
2065         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2066         if (IS_ERR(server)) {
2067                 error = PTR_ERR(server);
2068                 goto out_err_noserver;
2069         }
2070         sb_mntdata.server = server;
2071
2072         if (server->flags & NFS_MOUNT_UNSHARED)
2073                 compare_super = NULL;
2074
2075         /* Get a superblock - note that we may end up sharing one that already exists */
2076         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2077         if (IS_ERR(s)) {
2078                 error = PTR_ERR(s);
2079                 goto out_err_nosb;
2080         }
2081
2082         if (s->s_fs_info != server) {
2083                 nfs_free_server(server);
2084                 server = NULL;
2085         } else {
2086                 error = nfs_bdi_register(server);
2087                 if (error)
2088                         goto error_splat_super;
2089         }
2090
2091         if (!s->s_root) {
2092                 /* initial superblock/root creation */
2093                 nfs_clone_super(s, data->sb);
2094         }
2095
2096         mntroot = nfs_get_root(s, data->fh);
2097         if (IS_ERR(mntroot)) {
2098                 error = PTR_ERR(mntroot);
2099                 goto error_splat_super;
2100         }
2101         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2102                 dput(mntroot);
2103                 error = -ESTALE;
2104                 goto error_splat_super;
2105         }
2106
2107         s->s_flags |= MS_ACTIVE;
2108         mnt->mnt_sb = s;
2109         mnt->mnt_root = mntroot;
2110
2111         /* clone any lsm security options from the parent to the new sb */
2112         security_sb_clone_mnt_opts(data->sb, s);
2113
2114         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2115         return 0;
2116
2117 out_err_nosb:
2118         nfs_free_server(server);
2119 out_err_noserver:
2120         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2121         return error;
2122
2123 error_splat_super:
2124         up_write(&s->s_umount);
2125         deactivate_super(s);
2126         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2127         return error;
2128 }
2129
2130 #ifdef CONFIG_NFS_V4
2131
2132 /*
2133  * Finish setting up a cloned NFS4 superblock
2134  */
2135 static void nfs4_clone_super(struct super_block *sb,
2136                             const struct super_block *old_sb)
2137 {
2138         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2139         sb->s_blocksize = old_sb->s_blocksize;
2140         sb->s_maxbytes = old_sb->s_maxbytes;
2141         sb->s_time_gran = 1;
2142         sb->s_op = old_sb->s_op;
2143         nfs_initialise_sb(sb);
2144 }
2145
2146 /*
2147  * Set up an NFS4 superblock
2148  */
2149 static void nfs4_fill_super(struct super_block *sb)
2150 {
2151         sb->s_time_gran = 1;
2152         sb->s_op = &nfs4_sops;
2153         nfs_initialise_sb(sb);
2154 }
2155
2156 /*
2157  * Validate NFSv4 mount options
2158  */
2159 static int nfs4_validate_mount_data(void *options,
2160                                     struct nfs_parsed_mount_data *args,
2161                                     const char *dev_name)
2162 {
2163         struct sockaddr_in *ap;
2164         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2165         char *c;
2166
2167         if (data == NULL)
2168                 goto out_no_data;
2169
2170         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2171         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2172         args->acregmin          = NFS_DEF_ACREGMIN;
2173         args->acregmax          = NFS_DEF_ACREGMAX;
2174         args->acdirmin          = NFS_DEF_ACDIRMIN;
2175         args->acdirmax          = NFS_DEF_ACDIRMAX;
2176         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2177         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2178         args->auth_flavor_len   = 0;
2179
2180         switch (data->version) {
2181         case 1:
2182                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2183                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2184                         goto out_no_address;
2185                 if (data->host_addrlen == 0)
2186                         goto out_no_address;
2187                 args->nfs_server.addrlen = data->host_addrlen;
2188                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2189                         return -EFAULT;
2190                 if (!nfs_verify_server_address((struct sockaddr *)
2191                                                 &args->nfs_server.address))
2192                         goto out_no_address;
2193
2194                 if (data->auth_flavourlen) {
2195                         if (data->auth_flavourlen > 1)
2196                                 goto out_inval_auth;
2197                         if (copy_from_user(&args->auth_flavors[0],
2198                                            data->auth_flavours,
2199                                            sizeof(args->auth_flavors[0])))
2200                                 return -EFAULT;
2201                 }
2202
2203                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2204                 if (IS_ERR(c))
2205                         return PTR_ERR(c);
2206                 args->nfs_server.hostname = c;
2207
2208                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2209                 if (IS_ERR(c))
2210                         return PTR_ERR(c);
2211                 args->nfs_server.export_path = c;
2212                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2213
2214                 c = strndup_user(data->client_addr.data, 16);
2215                 if (IS_ERR(c))
2216                         return PTR_ERR(c);
2217                 args->client_address = c;
2218
2219                 /*
2220                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2221                  * can deal with.
2222                  */
2223
2224                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2225                 args->rsize     = data->rsize;
2226                 args->wsize     = data->wsize;
2227                 args->timeo     = data->timeo;
2228                 args->retrans   = data->retrans;
2229                 args->acregmin  = data->acregmin;
2230                 args->acregmax  = data->acregmax;
2231                 args->acdirmin  = data->acdirmin;
2232                 args->acdirmax  = data->acdirmax;
2233                 args->nfs_server.protocol = data->proto;
2234                 nfs_validate_transport_protocol(args);
2235
2236                 break;
2237         default: {
2238                 int status;
2239
2240                 if (nfs_parse_mount_options((char *)options, args) == 0)
2241                         return -EINVAL;
2242
2243                 if (!nfs_verify_server_address((struct sockaddr *)
2244                                                 &args->nfs_server.address))
2245                         return -EINVAL;
2246
2247                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
2248                                 args->nfs_server.port);
2249
2250                 nfs_validate_transport_protocol(args);
2251
2252                 if (args->auth_flavor_len > 1)
2253                         goto out_inval_auth;
2254
2255                 if (args->client_address == NULL)
2256                         goto out_no_client_address;
2257
2258                 status = nfs_parse_devname(dev_name,
2259                                            &args->nfs_server.hostname,
2260                                            NFS4_MAXNAMLEN,
2261                                            &args->nfs_server.export_path,
2262                                            NFS4_MAXPATHLEN);
2263                 if (status < 0)
2264                         return status;
2265
2266                 break;
2267                 }
2268         }
2269
2270         return 0;
2271
2272 out_no_data:
2273         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2274         return -EINVAL;
2275
2276 out_inval_auth:
2277         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2278                  data->auth_flavourlen);
2279         return -EINVAL;
2280
2281 out_no_address:
2282         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2283         return -EINVAL;
2284
2285 out_no_client_address:
2286         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2287         return -EINVAL;
2288 }
2289
2290 /*
2291  * Get the superblock for an NFS4 mountpoint
2292  */
2293 static int nfs4_get_sb(struct file_system_type *fs_type,
2294         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2295 {
2296         struct nfs_parsed_mount_data *data;
2297         struct super_block *s;
2298         struct nfs_server *server;
2299         struct nfs_fh *mntfh;
2300         struct dentry *mntroot;
2301         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2302         struct nfs_sb_mountdata sb_mntdata = {
2303                 .mntflags = flags,
2304         };
2305         int error = -ENOMEM;
2306
2307         data = kzalloc(sizeof(*data), GFP_KERNEL);
2308         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2309         if (data == NULL || mntfh == NULL)
2310                 goto out_free_fh;
2311
2312         security_init_mnt_opts(&data->lsm_opts);
2313
2314         /* Validate the mount data */
2315         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2316         if (error < 0)
2317                 goto out;
2318
2319         /* Get a volume representation */
2320         server = nfs4_create_server(data, mntfh);
2321         if (IS_ERR(server)) {
2322                 error = PTR_ERR(server);
2323                 goto out;
2324         }
2325         sb_mntdata.server = server;
2326
2327         if (server->flags & NFS4_MOUNT_UNSHARED)
2328                 compare_super = NULL;
2329
2330         /* Get a superblock - note that we may end up sharing one that already exists */
2331         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2332         if (IS_ERR(s)) {
2333                 error = PTR_ERR(s);
2334                 goto out_free;
2335         }
2336
2337         if (s->s_fs_info != server) {
2338                 nfs_free_server(server);
2339                 server = NULL;
2340         } else {
2341                 error = nfs_bdi_register(server);
2342                 if (error)
2343                         goto error_splat_super;
2344         }
2345
2346         if (!s->s_root) {
2347                 /* initial superblock/root creation */
2348                 nfs4_fill_super(s);
2349         }
2350
2351         mntroot = nfs4_get_root(s, mntfh);
2352         if (IS_ERR(mntroot)) {
2353                 error = PTR_ERR(mntroot);
2354                 goto error_splat_super;
2355         }
2356
2357         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2358         if (error)
2359                 goto error_splat_root;
2360
2361         s->s_flags |= MS_ACTIVE;
2362         mnt->mnt_sb = s;
2363         mnt->mnt_root = mntroot;
2364         error = 0;
2365
2366 out:
2367         kfree(data->client_address);
2368         kfree(data->nfs_server.export_path);
2369         kfree(data->nfs_server.hostname);
2370         security_free_mnt_opts(&data->lsm_opts);
2371 out_free_fh:
2372         kfree(mntfh);
2373         kfree(data);
2374         return error;
2375
2376 out_free:
2377         nfs_free_server(server);
2378         goto out;
2379
2380 error_splat_root:
2381         dput(mntroot);
2382 error_splat_super:
2383         up_write(&s->s_umount);
2384         deactivate_super(s);
2385         goto out;
2386 }
2387
2388 static void nfs4_kill_super(struct super_block *sb)
2389 {
2390         struct nfs_server *server = NFS_SB(sb);
2391
2392         nfs_return_all_delegations(sb);
2393         kill_anon_super(sb);
2394
2395         nfs4_renewd_prepare_shutdown(server);
2396         nfs_free_server(server);
2397 }
2398
2399 /*
2400  * Clone an NFS4 server record on xdev traversal (FSID-change)
2401  */
2402 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2403                             const char *dev_name, void *raw_data,
2404                             struct vfsmount *mnt)
2405 {
2406         struct nfs_clone_mount *data = raw_data;
2407         struct super_block *s;
2408         struct nfs_server *server;
2409         struct dentry *mntroot;
2410         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2411         struct nfs_sb_mountdata sb_mntdata = {
2412                 .mntflags = flags,
2413         };
2414         int error;
2415
2416         dprintk("--> nfs4_xdev_get_sb()\n");
2417
2418         /* create a new volume representation */
2419         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2420         if (IS_ERR(server)) {
2421                 error = PTR_ERR(server);
2422                 goto out_err_noserver;
2423         }
2424         sb_mntdata.server = server;
2425
2426         if (server->flags & NFS4_MOUNT_UNSHARED)
2427                 compare_super = NULL;
2428
2429         /* Get a superblock - note that we may end up sharing one that already exists */
2430         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2431         if (IS_ERR(s)) {
2432                 error = PTR_ERR(s);
2433                 goto out_err_nosb;
2434         }
2435
2436         if (s->s_fs_info != server) {
2437                 nfs_free_server(server);
2438                 server = NULL;
2439         } else {
2440                 error = nfs_bdi_register(server);
2441                 if (error)
2442                         goto error_splat_super;
2443         }
2444
2445         if (!s->s_root) {
2446                 /* initial superblock/root creation */
2447                 nfs4_clone_super(s, data->sb);
2448         }
2449
2450         mntroot = nfs4_get_root(s, data->fh);
2451         if (IS_ERR(mntroot)) {
2452                 error = PTR_ERR(mntroot);
2453                 goto error_splat_super;
2454         }
2455         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2456                 dput(mntroot);
2457                 error = -ESTALE;
2458                 goto error_splat_super;
2459         }
2460
2461         s->s_flags |= MS_ACTIVE;
2462         mnt->mnt_sb = s;
2463         mnt->mnt_root = mntroot;
2464
2465         security_sb_clone_mnt_opts(data->sb, s);
2466
2467         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2468         return 0;
2469
2470 out_err_nosb:
2471         nfs_free_server(server);
2472 out_err_noserver:
2473         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2474         return error;
2475
2476 error_splat_super:
2477         up_write(&s->s_umount);
2478         deactivate_super(s);
2479         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2480         return error;
2481 }
2482
2483 /*
2484  * Create an NFS4 server record on referral traversal
2485  */
2486 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2487                                 const char *dev_name, void *raw_data,
2488                                 struct vfsmount *mnt)
2489 {
2490         struct nfs_clone_mount *data = raw_data;
2491         struct super_block *s;
2492         struct nfs_server *server;
2493         struct dentry *mntroot;
2494         struct nfs_fh mntfh;
2495         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2496         struct nfs_sb_mountdata sb_mntdata = {
2497                 .mntflags = flags,
2498         };
2499         int error;
2500
2501         dprintk("--> nfs4_referral_get_sb()\n");
2502
2503         /* create a new volume representation */
2504         server = nfs4_create_referral_server(data, &mntfh);
2505         if (IS_ERR(server)) {
2506                 error = PTR_ERR(server);
2507                 goto out_err_noserver;
2508         }
2509         sb_mntdata.server = server;
2510
2511         if (server->flags & NFS4_MOUNT_UNSHARED)
2512                 compare_super = NULL;
2513
2514         /* Get a superblock - note that we may end up sharing one that already exists */
2515         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2516         if (IS_ERR(s)) {
2517                 error = PTR_ERR(s);
2518                 goto out_err_nosb;
2519         }
2520
2521         if (s->s_fs_info != server) {
2522                 nfs_free_server(server);
2523                 server = NULL;
2524         } else {
2525                 error = nfs_bdi_register(server);
2526                 if (error)
2527                         goto error_splat_super;
2528         }
2529
2530         if (!s->s_root) {
2531                 /* initial superblock/root creation */
2532                 nfs4_fill_super(s);
2533         }
2534
2535         mntroot = nfs4_get_root(s, &mntfh);
2536         if (IS_ERR(mntroot)) {
2537                 error = PTR_ERR(mntroot);
2538                 goto error_splat_super;
2539         }
2540         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2541                 dput(mntroot);
2542                 error = -ESTALE;
2543                 goto error_splat_super;
2544         }
2545
2546         s->s_flags |= MS_ACTIVE;
2547         mnt->mnt_sb = s;
2548         mnt->mnt_root = mntroot;
2549
2550         security_sb_clone_mnt_opts(data->sb, s);
2551
2552         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2553         return 0;
2554
2555 out_err_nosb:
2556         nfs_free_server(server);
2557 out_err_noserver:
2558         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2559         return error;
2560
2561 error_splat_super:
2562         up_write(&s->s_umount);
2563         deactivate_super(s);
2564         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2565         return error;
2566 }
2567
2568 #endif /* CONFIG_NFS_V4 */