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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/nfs_xdr.h>
  49 #include <linux/magic.h>
  50 #include <linux/parser.h>
  51
  52 #include <asm/system.h>
  53 #include <asm/uaccess.h>
  54
  55 #include "nfs4_fs.h"
  56 #include "callback.h"
  57 #include "delegation.h"
  58 #include "iostat.h"
  59 #include "internal.h"
  60
  61 #define NFSDBG_FACILITY         NFSDBG_VFS
  62
  63 enum {
  64         /* Mount options that take no arguments */
  65         Opt_soft, Opt_hard,
  66         Opt_intr, Opt_nointr,
  67         Opt_posix, Opt_noposix,
  68         Opt_cto, Opt_nocto,
  69         Opt_ac, Opt_noac,
  70         Opt_lock, Opt_nolock,
  71         Opt_v2, Opt_v3,
  72         Opt_udp, Opt_tcp, Opt_rdma,
  73         Opt_acl, Opt_noacl,
  74         Opt_rdirplus, Opt_nordirplus,
  75         Opt_sharecache, Opt_nosharecache,
  76
  77         /* Mount options that take integer arguments */
  78         Opt_port,
  79         Opt_rsize, Opt_wsize, Opt_bsize,
  80         Opt_timeo, Opt_retrans,
  81         Opt_acregmin, Opt_acregmax,
  82         Opt_acdirmin, Opt_acdirmax,
  83         Opt_actimeo,
  84         Opt_namelen,
  85         Opt_mountport,
  86         Opt_mountprog, Opt_mountvers,
  87         Opt_nfsprog, Opt_nfsvers,
  88
  89         /* Mount options that take string arguments */
  90         Opt_sec, Opt_proto, Opt_mountproto,
  91         Opt_addr, Opt_mountaddr, Opt_clientaddr,
  92
  93         /* Mount options that are ignored */
  94         Opt_userspace, Opt_deprecated,
  95
  96         Opt_err
  97 };
  98
  99 static match_table_t nfs_mount_option_tokens = {
 100         { Opt_userspace, "bg" },
 101         { Opt_userspace, "fg" },
 102         { Opt_soft, "soft" },
 103         { Opt_hard, "hard" },
 104         { Opt_intr, "intr" },
 105         { Opt_nointr, "nointr" },
 106         { Opt_posix, "posix" },
 107         { Opt_noposix, "noposix" },
 108         { Opt_cto, "cto" },
 109         { Opt_nocto, "nocto" },
 110         { Opt_ac, "ac" },
 111         { Opt_noac, "noac" },
 112         { Opt_lock, "lock" },
 113         { Opt_nolock, "nolock" },
 114         { Opt_v2, "v2" },
 115         { Opt_v3, "v3" },
 116         { Opt_udp, "udp" },
 117         { Opt_tcp, "tcp" },
 118         { Opt_rdma, "rdma" },
 119         { Opt_acl, "acl" },
 120         { Opt_noacl, "noacl" },
 121         { Opt_rdirplus, "rdirplus" },
 122         { Opt_nordirplus, "nordirplus" },
 123         { Opt_sharecache, "sharecache" },
 124         { Opt_nosharecache, "nosharecache" },
 125
 126         { Opt_port, "port=%u" },
 127         { Opt_rsize, "rsize=%u" },
 128         { Opt_wsize, "wsize=%u" },
 129         { Opt_bsize, "bsize=%u" },
 130         { Opt_timeo, "timeo=%u" },
 131         { Opt_retrans, "retrans=%u" },
 132         { Opt_acregmin, "acregmin=%u" },
 133         { Opt_acregmax, "acregmax=%u" },
 134         { Opt_acdirmin, "acdirmin=%u" },
 135         { Opt_acdirmax, "acdirmax=%u" },
 136         { Opt_actimeo, "actimeo=%u" },
 137         { Opt_userspace, "retry=%u" },
 138         { Opt_namelen, "namlen=%u" },
 139         { Opt_mountport, "mountport=%u" },
 140         { Opt_mountprog, "mountprog=%u" },
 141         { Opt_mountvers, "mountvers=%u" },
 142         { Opt_nfsprog, "nfsprog=%u" },
 143         { Opt_nfsvers, "nfsvers=%u" },
 144         { Opt_nfsvers, "vers=%u" },
 145
 146         { Opt_sec, "sec=%s" },
 147         { Opt_proto, "proto=%s" },
 148         { Opt_mountproto, "mountproto=%s" },
 149         { Opt_addr, "addr=%s" },
 150         { Opt_clientaddr, "clientaddr=%s" },
 151         { Opt_userspace, "mounthost=%s" },
 152         { Opt_mountaddr, "mountaddr=%s" },
 153
 154         { Opt_err, NULL }
 155 };
 156
 157 enum {
 158         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 159
 160         Opt_xprt_err
 161 };
 162
 163 static match_table_t nfs_xprt_protocol_tokens = {
 164         { Opt_xprt_udp, "udp" },
 165         { Opt_xprt_tcp, "tcp" },
 166         { Opt_xprt_rdma, "rdma" },
 167
 168         { Opt_xprt_err, NULL }
 169 };
 170
 171 enum {
 172         Opt_sec_none, Opt_sec_sys,
 173         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 174         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 175         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 176
 177         Opt_sec_err
 178 };
 179
 180 static match_table_t nfs_secflavor_tokens = {
 181         { Opt_sec_none, "none" },
 182         { Opt_sec_none, "null" },
 183         { Opt_sec_sys, "sys" },
 184
 185         { Opt_sec_krb5, "krb5" },
 186         { Opt_sec_krb5i, "krb5i" },
 187         { Opt_sec_krb5p, "krb5p" },
 188
 189         { Opt_sec_lkey, "lkey" },
 190         { Opt_sec_lkeyi, "lkeyi" },
 191         { Opt_sec_lkeyp, "lkeyp" },
 192
 193         { Opt_sec_err, NULL }
 194 };
 195
 196
 197 static void nfs_umount_begin(struct vfsmount *, int);
 198 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 199 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 200 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 201 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 202 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 203                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 204 static void nfs_kill_super(struct super_block *);
 205
 206 static struct file_system_type nfs_fs_type = {
 207         .owner          = THIS_MODULE,
 208         .name           = "nfs",
 209         .get_sb         = nfs_get_sb,
 210         .kill_sb        = nfs_kill_super,
 211         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 212 };
 213
 214 struct file_system_type nfs_xdev_fs_type = {
 215         .owner          = THIS_MODULE,
 216         .name           = "nfs",
 217         .get_sb         = nfs_xdev_get_sb,
 218         .kill_sb        = nfs_kill_super,
 219         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 220 };
 221
 222 static const struct super_operations nfs_sops = {
 223         .alloc_inode    = nfs_alloc_inode,
 224         .destroy_inode  = nfs_destroy_inode,
 225         .write_inode    = nfs_write_inode,
 226         .statfs         = nfs_statfs,
 227         .clear_inode    = nfs_clear_inode,
 228         .umount_begin   = nfs_umount_begin,
 229         .show_options   = nfs_show_options,
 230         .show_stats     = nfs_show_stats,
 231 };
 232
 233 #ifdef CONFIG_NFS_V4
 234 static int nfs4_get_sb(struct file_system_type *fs_type,
 235         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 236 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 237         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 238 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 239         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 240 static void nfs4_kill_super(struct super_block *sb);
 241
 242 static struct file_system_type nfs4_fs_type = {
 243         .owner          = THIS_MODULE,
 244         .name           = "nfs4",
 245         .get_sb         = nfs4_get_sb,
 246         .kill_sb        = nfs4_kill_super,
 247         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 248 };
 249
 250 struct file_system_type nfs4_xdev_fs_type = {
 251         .owner          = THIS_MODULE,
 252         .name           = "nfs4",
 253         .get_sb         = nfs4_xdev_get_sb,
 254         .kill_sb        = nfs4_kill_super,
 255         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 256 };
 257
 258 struct file_system_type nfs4_referral_fs_type = {
 259         .owner          = THIS_MODULE,
 260         .name           = "nfs4",
 261         .get_sb         = nfs4_referral_get_sb,
 262         .kill_sb        = nfs4_kill_super,
 263         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 264 };
 265
 266 static const struct super_operations nfs4_sops = {
 267         .alloc_inode    = nfs_alloc_inode,
 268         .destroy_inode  = nfs_destroy_inode,
 269         .write_inode    = nfs_write_inode,
 270         .statfs         = nfs_statfs,
 271         .clear_inode    = nfs4_clear_inode,
 272         .umount_begin   = nfs_umount_begin,
 273         .show_options   = nfs_show_options,
 274         .show_stats     = nfs_show_stats,
 275 };
 276 #endif
 277
 278 static struct shrinker acl_shrinker = {
 279         .shrink         = nfs_access_cache_shrinker,
 280         .seeks          = DEFAULT_SEEKS,
 281 };
 282
 283 /*
 284  * Register the NFS filesystems
 285  */
 286 int __init register_nfs_fs(void)
 287 {
 288         int ret;
 289
 290         ret = register_filesystem(&nfs_fs_type);
 291         if (ret < 0)
 292                 goto error_0;
 293
 294         ret = nfs_register_sysctl();
 295         if (ret < 0)
 296                 goto error_1;
 297 #ifdef CONFIG_NFS_V4
 298         ret = register_filesystem(&nfs4_fs_type);
 299         if (ret < 0)
 300                 goto error_2;
 301 #endif
 302         register_shrinker(&acl_shrinker);
 303         return 0;
 304
 305 #ifdef CONFIG_NFS_V4
 306 error_2:
 307         nfs_unregister_sysctl();
 308 #endif
 309 error_1:
 310         unregister_filesystem(&nfs_fs_type);
 311 error_0:
 312         return ret;
 313 }
 314
 315 /*
 316  * Unregister the NFS filesystems
 317  */
 318 void __exit unregister_nfs_fs(void)
 319 {
 320         unregister_shrinker(&acl_shrinker);
 321 #ifdef CONFIG_NFS_V4
 322         unregister_filesystem(&nfs4_fs_type);
 323 #endif
 324         nfs_unregister_sysctl();
 325         unregister_filesystem(&nfs_fs_type);
 326 }
 327
 328 /*
 329  * Deliver file system statistics to userspace
 330  */
 331 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 332 {
 333         struct nfs_server *server = NFS_SB(dentry->d_sb);
 334         unsigned char blockbits;
 335         unsigned long blockres;
 336         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 337         struct nfs_fattr fattr;
 338         struct nfs_fsstat res = {
 339                         .fattr = &fattr,
 340         };
 341         int error;
 342
 343         lock_kernel();
 344
 345         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 346         if (error < 0)
 347                 goto out_err;
 348         buf->f_type = NFS_SUPER_MAGIC;
 349
 350         /*
 351          * Current versions of glibc do not correctly handle the
 352          * case where f_frsize != f_bsize.  Eventually we want to
 353          * report the value of wtmult in this field.
 354          */
 355         buf->f_frsize = dentry->d_sb->s_blocksize;
 356
 357         /*
 358          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 359          * are reported in units of f_frsize.  Linux hasn't had
 360          * an f_frsize field in its statfs struct until recently,
 361          * thus historically Linux's sys_statfs reports these
 362          * fields in units of f_bsize.
 363          */
 364         buf->f_bsize = dentry->d_sb->s_blocksize;
 365         blockbits = dentry->d_sb->s_blocksize_bits;
 366         blockres = (1 << blockbits) - 1;
 367         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 368         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 369         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 370
 371         buf->f_files = res.tfiles;
 372         buf->f_ffree = res.afiles;
 373
 374         buf->f_namelen = server->namelen;
 375
 376         unlock_kernel();
 377         return 0;
 378
 379  out_err:
 380         dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
 381         unlock_kernel();
 382         return error;
 383 }
 384
 385 /*
 386  * Map the security flavour number to a name
 387  */
 388 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 389 {
 390         static const struct {
 391                 rpc_authflavor_t flavour;
 392                 const char *str;
 393         } sec_flavours[] = {
 394                 { RPC_AUTH_NULL, "null" },
 395                 { RPC_AUTH_UNIX, "sys" },
 396                 { RPC_AUTH_GSS_KRB5, "krb5" },
 397                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 398                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 399                 { RPC_AUTH_GSS_LKEY, "lkey" },
 400                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 401                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 402                 { RPC_AUTH_GSS_SPKM, "spkm" },
 403                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 404                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 405                 { UINT_MAX, "unknown" }
 406         };
 407         int i;
 408
 409         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 410                 if (sec_flavours[i].flavour == flavour)
 411                         break;
 412         }
 413         return sec_flavours[i].str;
 414 }
 415
 416 /*
 417  * Describe the mount options in force on this server representation
 418  */
 419 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
 420 {
 421         static const struct proc_nfs_info {
 422                 int flag;
 423                 const char *str;
 424                 const char *nostr;
 425         } nfs_info[] = {
 426                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 427                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 428                 { NFS_MOUNT_NOAC, ",noac", "" },
 429                 { NFS_MOUNT_NONLM, ",nolock", "" },
 430                 { NFS_MOUNT_NOACL, ",noacl", "" },
 431                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 432                 { NFS_MOUNT_UNSHARED, ",nosharecache", ""},
 433                 { 0, NULL, NULL }
 434         };
 435         const struct proc_nfs_info *nfs_infop;
 436         struct nfs_client *clp = nfss->nfs_client;
 437
 438         seq_printf(m, ",vers=%d", clp->rpc_ops->version);
 439         seq_printf(m, ",rsize=%d", nfss->rsize);
 440         seq_printf(m, ",wsize=%d", nfss->wsize);
 441         if (nfss->acregmin != 3*HZ || showdefaults)
 442                 seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
 443         if (nfss->acregmax != 60*HZ || showdefaults)
 444                 seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
 445         if (nfss->acdirmin != 30*HZ || showdefaults)
 446                 seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
 447         if (nfss->acdirmax != 60*HZ || showdefaults)
 448                 seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
 449         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 450                 if (nfss->flags & nfs_infop->flag)
 451                         seq_puts(m, nfs_infop->str);
 452                 else
 453                         seq_puts(m, nfs_infop->nostr);
 454         }
 455         seq_printf(m, ",proto=%s",
 456                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 457         seq_printf(m, ",timeo=%lu", 10U * clp->retrans_timeo / HZ);
 458         seq_printf(m, ",retrans=%u", clp->retrans_count);
 459         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 460 }
 461
 462 /*
 463  * Describe the mount options on this VFS mountpoint
 464  */
 465 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 466 {
 467         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 468
 469         nfs_show_mount_options(m, nfss, 0);
 470
 471         seq_printf(m, ",addr="NIPQUAD_FMT,
 472                 NIPQUAD(nfss->nfs_client->cl_addr.sin_addr));
 473
 474         return 0;
 475 }
 476
 477 /*
 478  * Present statistical information for this VFS mountpoint
 479  */
 480 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 481 {
 482         int i, cpu;
 483         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 484         struct rpc_auth *auth = nfss->client->cl_auth;
 485         struct nfs_iostats totals = { };
 486
 487         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 488
 489         /*
 490          * Display all mount option settings
 491          */
 492         seq_printf(m, "\n\topts:\t");
 493         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 494         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 495         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 496         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 497         nfs_show_mount_options(m, nfss, 1);
 498
 499         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 500
 501         seq_printf(m, "\n\tcaps:\t");
 502         seq_printf(m, "caps=0x%x", nfss->caps);
 503         seq_printf(m, ",wtmult=%d", nfss->wtmult);
 504         seq_printf(m, ",dtsize=%d", nfss->dtsize);
 505         seq_printf(m, ",bsize=%d", nfss->bsize);
 506         seq_printf(m, ",namelen=%d", nfss->namelen);
 507
 508 #ifdef CONFIG_NFS_V4
 509         if (nfss->nfs_client->cl_nfsversion == 4) {
 510                 seq_printf(m, "\n\tnfsv4:\t");
 511                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 512                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 513                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 514         }
 515 #endif
 516
 517         /*
 518          * Display security flavor in effect for this mount
 519          */
 520         seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
 521         if (auth->au_flavor)
 522                 seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
 523
 524         /*
 525          * Display superblock I/O counters
 526          */
 527         for_each_possible_cpu(cpu) {
 528                 struct nfs_iostats *stats;
 529
 530                 preempt_disable();
 531                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 532
 533                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 534                         totals.events[i] += stats->events[i];
 535                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 536                         totals.bytes[i] += stats->bytes[i];
 537
 538                 preempt_enable();
 539         }
 540
 541         seq_printf(m, "\n\tevents:\t");
 542         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 543                 seq_printf(m, "%lu ", totals.events[i]);
 544         seq_printf(m, "\n\tbytes:\t");
 545         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 546                 seq_printf(m, "%Lu ", totals.bytes[i]);
 547         seq_printf(m, "\n");
 548
 549         rpc_print_iostats(m, nfss->client);
 550
 551         return 0;
 552 }
 553
 554 /*
 555  * Begin unmount by attempting to remove all automounted mountpoints we added
 556  * in response to xdev traversals and referrals
 557  */
 558 static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
 559 {
 560         struct nfs_server *server = NFS_SB(vfsmnt->mnt_sb);
 561         struct rpc_clnt *rpc;
 562
 563         shrink_submounts(vfsmnt, &nfs_automount_list);
 564
 565         if (!(flags & MNT_FORCE))
 566                 return;
 567         /* -EIO all pending I/O */
 568         rpc = server->client_acl;
 569         if (!IS_ERR(rpc))
 570                 rpc_killall_tasks(rpc);
 571         rpc = server->client;
 572         if (!IS_ERR(rpc))
 573                 rpc_killall_tasks(rpc);
 574 }
 575
 576 /*
 577  * Sanity-check a server address provided by the mount command
 578  */
 579 static int nfs_verify_server_address(struct sockaddr *addr)
 580 {
 581         switch (addr->sa_family) {
 582         case AF_INET: {
 583                 struct sockaddr_in *sa = (struct sockaddr_in *) addr;
 584                 if (sa->sin_addr.s_addr != INADDR_ANY)
 585                         return 1;
 586                 break;
 587         }
 588         }
 589
 590         return 0;
 591 }
 592
 593 /*
 594  * Error-check and convert a string of mount options from user space into
 595  * a data structure
 596  */
 597 static int nfs_parse_mount_options(char *raw,
 598                                    struct nfs_parsed_mount_data *mnt)
 599 {
 600         char *p, *string;
 601
 602         if (!raw) {
 603                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 604                 return 1;
 605         }
 606         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 607
 608         while ((p = strsep(&raw, ",")) != NULL) {
 609                 substring_t args[MAX_OPT_ARGS];
 610                 int option, token;
 611
 612                 if (!*p)
 613                         continue;
 614
 615                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 616
 617                 token = match_token(p, nfs_mount_option_tokens, args);
 618                 switch (token) {
 619                 case Opt_soft:
 620                         mnt->flags |= NFS_MOUNT_SOFT;
 621                         break;
 622                 case Opt_hard:
 623                         mnt->flags &= ~NFS_MOUNT_SOFT;
 624                         break;
 625                 case Opt_intr:
 626                 case Opt_nointr:
 627                         break;
 628                 case Opt_posix:
 629                         mnt->flags |= NFS_MOUNT_POSIX;
 630                         break;
 631                 case Opt_noposix:
 632                         mnt->flags &= ~NFS_MOUNT_POSIX;
 633                         break;
 634                 case Opt_cto:
 635                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 636                         break;
 637                 case Opt_nocto:
 638                         mnt->flags |= NFS_MOUNT_NOCTO;
 639                         break;
 640                 case Opt_ac:
 641                         mnt->flags &= ~NFS_MOUNT_NOAC;
 642                         break;
 643                 case Opt_noac:
 644                         mnt->flags |= NFS_MOUNT_NOAC;
 645                         break;
 646                 case Opt_lock:
 647                         mnt->flags &= ~NFS_MOUNT_NONLM;
 648                         break;
 649                 case Opt_nolock:
 650                         mnt->flags |= NFS_MOUNT_NONLM;
 651                         break;
 652                 case Opt_v2:
 653                         mnt->flags &= ~NFS_MOUNT_VER3;
 654                         break;
 655                 case Opt_v3:
 656                         mnt->flags |= NFS_MOUNT_VER3;
 657                         break;
 658                 case Opt_udp:
 659                         mnt->flags &= ~NFS_MOUNT_TCP;
 660                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 661                         mnt->timeo = 7;
 662                         mnt->retrans = 5;
 663                         break;
 664                 case Opt_tcp:
 665                         mnt->flags |= NFS_MOUNT_TCP;
 666                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 667                         mnt->timeo = 600;
 668                         mnt->retrans = 2;
 669                         break;
 670                 case Opt_rdma:
 671                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 672                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 673                         mnt->timeo = 600;
 674                         mnt->retrans = 2;
 675                         break;
 676                 case Opt_acl:
 677                         mnt->flags &= ~NFS_MOUNT_NOACL;
 678                         break;
 679                 case Opt_noacl:
 680                         mnt->flags |= NFS_MOUNT_NOACL;
 681                         break;
 682                 case Opt_rdirplus:
 683                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 684                         break;
 685                 case Opt_nordirplus:
 686                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 687                         break;
 688                 case Opt_sharecache:
 689                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 690                         break;
 691                 case Opt_nosharecache:
 692                         mnt->flags |= NFS_MOUNT_UNSHARED;
 693                         break;
 694
 695                 case Opt_port:
 696                         if (match_int(args, &option))
 697                                 return 0;
 698                         if (option < 0 || option > 65535)
 699                                 return 0;
 700                         mnt->nfs_server.address.sin_port = htons(option);
 701                         break;
 702                 case Opt_rsize:
 703                         if (match_int(args, &mnt->rsize))
 704                                 return 0;
 705                         break;
 706                 case Opt_wsize:
 707                         if (match_int(args, &mnt->wsize))
 708                                 return 0;
 709                         break;
 710                 case Opt_bsize:
 711                         if (match_int(args, &option))
 712                                 return 0;
 713                         if (option < 0)
 714                                 return 0;
 715                         mnt->bsize = option;
 716                         break;
 717                 case Opt_timeo:
 718                         if (match_int(args, &mnt->timeo))
 719                                 return 0;
 720                         break;
 721                 case Opt_retrans:
 722                         if (match_int(args, &mnt->retrans))
 723                                 return 0;
 724                         break;
 725                 case Opt_acregmin:
 726                         if (match_int(args, &mnt->acregmin))
 727                                 return 0;
 728                         break;
 729                 case Opt_acregmax:
 730                         if (match_int(args, &mnt->acregmax))
 731                                 return 0;
 732                         break;
 733                 case Opt_acdirmin:
 734                         if (match_int(args, &mnt->acdirmin))
 735                                 return 0;
 736                         break;
 737                 case Opt_acdirmax:
 738                         if (match_int(args, &mnt->acdirmax))
 739                                 return 0;
 740                         break;
 741                 case Opt_actimeo:
 742                         if (match_int(args, &option))
 743                                 return 0;
 744                         if (option < 0)
 745                                 return 0;
 746                         mnt->acregmin =
 747                         mnt->acregmax =
 748                         mnt->acdirmin =
 749                         mnt->acdirmax = option;
 750                         break;
 751                 case Opt_namelen:
 752                         if (match_int(args, &mnt->namlen))
 753                                 return 0;
 754                         break;
 755                 case Opt_mountport:
 756                         if (match_int(args, &option))
 757                                 return 0;
 758                         if (option < 0 || option > 65535)
 759                                 return 0;
 760                         mnt->mount_server.port = option;
 761                         break;
 762                 case Opt_mountprog:
 763                         if (match_int(args, &option))
 764                                 return 0;
 765                         if (option < 0)
 766                                 return 0;
 767                         mnt->mount_server.program = option;
 768                         break;
 769                 case Opt_mountvers:
 770                         if (match_int(args, &option))
 771                                 return 0;
 772                         if (option < 0)
 773                                 return 0;
 774                         mnt->mount_server.version = option;
 775                         break;
 776                 case Opt_nfsprog:
 777                         if (match_int(args, &option))
 778                                 return 0;
 779                         if (option < 0)
 780                                 return 0;
 781                         mnt->nfs_server.program = option;
 782                         break;
 783                 case Opt_nfsvers:
 784                         if (match_int(args, &option))
 785                                 return 0;
 786                         switch (option) {
 787                         case 2:
 788                                 mnt->flags &= ~NFS_MOUNT_VER3;
 789                                 break;
 790                         case 3:
 791                                 mnt->flags |= NFS_MOUNT_VER3;
 792                                 break;
 793                         default:
 794                                 goto out_unrec_vers;
 795                         }
 796                         break;
 797
 798                 case Opt_sec:
 799                         string = match_strdup(args);
 800                         if (string == NULL)
 801                                 goto out_nomem;
 802                         token = match_token(string, nfs_secflavor_tokens, args);
 803                         kfree(string);
 804
 805                         /*
 806                          * The flags setting is for v2/v3.  The flavor_len
 807                          * setting is for v4.  v2/v3 also need to know the
 808                          * difference between NULL and UNIX.
 809                          */
 810                         switch (token) {
 811                         case Opt_sec_none:
 812                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
 813                                 mnt->auth_flavor_len = 0;
 814                                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 815                                 break;
 816                         case Opt_sec_sys:
 817                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
 818                                 mnt->auth_flavor_len = 0;
 819                                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 820                                 break;
 821                         case Opt_sec_krb5:
 822                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 823                                 mnt->auth_flavor_len = 1;
 824                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 825                                 break;
 826                         case Opt_sec_krb5i:
 827                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 828                                 mnt->auth_flavor_len = 1;
 829                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 830                                 break;
 831                         case Opt_sec_krb5p:
 832                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 833                                 mnt->auth_flavor_len = 1;
 834                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 835                                 break;
 836                         case Opt_sec_lkey:
 837                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 838                                 mnt->auth_flavor_len = 1;
 839                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 840                                 break;
 841                         case Opt_sec_lkeyi:
 842                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 843                                 mnt->auth_flavor_len = 1;
 844                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 845                                 break;
 846                         case Opt_sec_lkeyp:
 847                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 848                                 mnt->auth_flavor_len = 1;
 849                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 850                                 break;
 851                         case Opt_sec_spkm:
 852                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 853                                 mnt->auth_flavor_len = 1;
 854                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 855                                 break;
 856                         case Opt_sec_spkmi:
 857                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 858                                 mnt->auth_flavor_len = 1;
 859                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 860                                 break;
 861                         case Opt_sec_spkmp:
 862                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 863                                 mnt->auth_flavor_len = 1;
 864                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 865                                 break;
 866                         default:
 867                                 goto out_unrec_sec;
 868                         }
 869                         break;
 870                 case Opt_proto:
 871                         string = match_strdup(args);
 872                         if (string == NULL)
 873                                 goto out_nomem;
 874                         token = match_token(string,
 875                                             nfs_xprt_protocol_tokens, args);
 876                         kfree(string);
 877
 878                         switch (token) {
 879                         case Opt_xprt_udp:
 880                                 mnt->flags &= ~NFS_MOUNT_TCP;
 881                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 882                                 mnt->timeo = 7;
 883                                 mnt->retrans = 5;
 884                                 break;
 885                         case Opt_xprt_tcp:
 886                                 mnt->flags |= NFS_MOUNT_TCP;
 887                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 888                                 mnt->timeo = 600;
 889                                 mnt->retrans = 2;
 890                                 break;
 891                         case Opt_xprt_rdma:
 892                                 /* vector side protocols to TCP */
 893                                 mnt->flags |= NFS_MOUNT_TCP;
 894                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 895                                 mnt->timeo = 600;
 896                                 mnt->retrans = 2;
 897                                 break;
 898                         default:
 899                                 goto out_unrec_xprt;
 900                         }
 901                         break;
 902                 case Opt_mountproto:
 903                         string = match_strdup(args);
 904                         if (string == NULL)
 905                                 goto out_nomem;
 906                         token = match_token(string,
 907                                             nfs_xprt_protocol_tokens, args);
 908                         kfree(string);
 909
 910                         switch (token) {
 911                         case Opt_xprt_udp:
 912                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 913                                 break;
 914                         case Opt_xprt_tcp:
 915                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 916                                 break;
 917                         case Opt_xprt_rdma: /* not used for side protocols */
 918                         default:
 919                                 goto out_unrec_xprt;
 920                         }
 921                         break;
 922                 case Opt_addr:
 923                         string = match_strdup(args);
 924                         if (string == NULL)
 925                                 goto out_nomem;
 926                         mnt->nfs_server.address.sin_family = AF_INET;
 927                         mnt->nfs_server.address.sin_addr.s_addr =
 928                                                         in_aton(string);
 929                         kfree(string);
 930                         break;
 931                 case Opt_clientaddr:
 932                         string = match_strdup(args);
 933                         if (string == NULL)
 934                                 goto out_nomem;
 935                         mnt->client_address = string;
 936                         break;
 937                 case Opt_mountaddr:
 938                         string = match_strdup(args);
 939                         if (string == NULL)
 940                                 goto out_nomem;
 941                         mnt->mount_server.address.sin_family = AF_INET;
 942                         mnt->mount_server.address.sin_addr.s_addr =
 943                                                         in_aton(string);
 944                         kfree(string);
 945                         break;
 946
 947                 case Opt_userspace:
 948                 case Opt_deprecated:
 949                         break;
 950
 951                 default:
 952                         goto out_unknown;
 953                 }
 954         }
 955
 956         return 1;
 957
 958 out_nomem:
 959         printk(KERN_INFO "NFS: not enough memory to parse option\n");
 960         return 0;
 961
 962 out_unrec_vers:
 963         printk(KERN_INFO "NFS: unrecognized NFS version number\n");
 964         return 0;
 965
 966 out_unrec_xprt:
 967         printk(KERN_INFO "NFS: unrecognized transport protocol\n");
 968         return 0;
 969
 970 out_unrec_sec:
 971         printk(KERN_INFO "NFS: unrecognized security flavor\n");
 972         return 0;
 973
 974 out_unknown:
 975         printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
 976         return 0;
 977 }
 978
 979 /*
 980  * Use the remote server's MOUNT service to request the NFS file handle
 981  * corresponding to the provided path.
 982  */
 983 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
 984                          struct nfs_fh *root_fh)
 985 {
 986         struct sockaddr_in sin;
 987         int status;
 988
 989         if (args->mount_server.version == 0) {
 990                 if (args->flags & NFS_MOUNT_VER3)
 991                         args->mount_server.version = NFS_MNT3_VERSION;
 992                 else
 993                         args->mount_server.version = NFS_MNT_VERSION;
 994         }
 995
 996         /*
 997          * Construct the mount server's address.
 998          */
 999         if (args->mount_server.address.sin_addr.s_addr != INADDR_ANY)
1000                 sin = args->mount_server.address;
1001         else
1002                 sin = args->nfs_server.address;
1003         /*
1004          * autobind will be used if mount_server.port == 0
1005          */
1006         sin.sin_port = htons(args->mount_server.port);
1007
1008         /*
1009          * Now ask the mount server to map our export path
1010          * to a file handle.
1011          */
1012         status = nfs_mount((struct sockaddr *) &sin,
1013                            sizeof(sin),
1014                            args->nfs_server.hostname,
1015                            args->nfs_server.export_path,
1016                            args->mount_server.version,
1017                            args->mount_server.protocol,
1018                            root_fh);
1019         if (status == 0)
1020                 return 0;
1021
1022         dfprintk(MOUNT, "NFS: unable to mount server " NIPQUAD_FMT
1023                         ", error %d\n", NIPQUAD(sin.sin_addr.s_addr), status);
1024         return status;
1025 }
1026
1027 /*
1028  * Validate the NFS2/NFS3 mount data
1029  * - fills in the mount root filehandle
1030  *
1031  * For option strings, user space handles the following behaviors:
1032  *
1033  * + DNS: mapping server host name to IP address ("addr=" option)
1034  *
1035  * + failure mode: how to behave if a mount request can't be handled
1036  *   immediately ("fg/bg" option)
1037  *
1038  * + retry: how often to retry a mount request ("retry=" option)
1039  *
1040  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1041  *   mountproto=tcp after mountproto=udp, and so on
1042  *
1043  * XXX: as far as I can tell, changing the NFS program number is not
1044  *      supported in the NFS client.
1045  */
1046 static int nfs_validate_mount_data(void *options,
1047                                    struct nfs_parsed_mount_data *args,
1048                                    struct nfs_fh *mntfh,
1049                                    const char *dev_name)
1050 {
1051         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1052
1053         memset(args, 0, sizeof(*args));
1054
1055         if (data == NULL)
1056                 goto out_no_data;
1057
1058         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1059         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1060         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1061         args->timeo             = 600;
1062         args->retrans           = 2;
1063         args->acregmin          = 3;
1064         args->acregmax          = 60;
1065         args->acdirmin          = 30;
1066         args->acdirmax          = 60;
1067         args->mount_server.protocol = XPRT_TRANSPORT_UDP;
1068         args->mount_server.program = NFS_MNT_PROGRAM;
1069         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1070         args->nfs_server.program = NFS_PROGRAM;
1071
1072         switch (data->version) {
1073         case 1:
1074                 data->namlen = 0;
1075         case 2:
1076                 data->bsize = 0;
1077         case 3:
1078                 if (data->flags & NFS_MOUNT_VER3)
1079                         goto out_no_v3;
1080                 data->root.size = NFS2_FHSIZE;
1081                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1082         case 4:
1083                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1084                         goto out_no_sec;
1085         case 5:
1086                 memset(data->context, 0, sizeof(data->context));
1087         case 6:
1088                 if (data->flags & NFS_MOUNT_VER3)
1089                         mntfh->size = data->root.size;
1090                 else
1091                         mntfh->size = NFS2_FHSIZE;
1092
1093                 if (mntfh->size > sizeof(mntfh->data))
1094                         goto out_invalid_fh;
1095
1096                 memcpy(mntfh->data, data->root.data, mntfh->size);
1097                 if (mntfh->size < sizeof(mntfh->data))
1098                         memset(mntfh->data + mntfh->size, 0,
1099                                sizeof(mntfh->data) - mntfh->size);
1100
1101                 if (!nfs_verify_server_address((struct sockaddr *) &data->addr))
1102                         goto out_no_address;
1103
1104                 /*
1105                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1106                  * can deal with.
1107                  */
1108                 args->flags             = data->flags;
1109                 args->rsize             = data->rsize;
1110                 args->wsize             = data->wsize;
1111                 args->flags             = data->flags;
1112                 args->timeo             = data->timeo;
1113                 args->retrans           = data->retrans;
1114                 args->acregmin          = data->acregmin;
1115                 args->acregmax          = data->acregmax;
1116                 args->acdirmin          = data->acdirmin;
1117                 args->acdirmax          = data->acdirmax;
1118                 args->nfs_server.address = data->addr;
1119                 if (!(data->flags & NFS_MOUNT_TCP))
1120                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1121                 /* N.B. caller will free nfs_server.hostname in all cases */
1122                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1123                 args->namlen            = data->namlen;
1124                 args->bsize             = data->bsize;
1125                 args->auth_flavors[0]   = data->pseudoflavor;
1126                 break;
1127         default: {
1128                 unsigned int len;
1129                 char *c;
1130                 int status;
1131
1132                 if (nfs_parse_mount_options((char *)options, args) == 0)
1133                         return -EINVAL;
1134
1135                 if (!nfs_verify_server_address((struct sockaddr *)
1136                                                 &args->nfs_server.address))
1137                         goto out_no_address;
1138
1139                 c = strchr(dev_name, ':');
1140                 if (c == NULL)
1141                         return -EINVAL;
1142                 len = c - dev_name;
1143                 /* N.B. caller will free nfs_server.hostname in all cases */
1144                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1145
1146                 c++;
1147                 if (strlen(c) > NFS_MAXPATHLEN)
1148                         return -ENAMETOOLONG;
1149                 args->nfs_server.export_path = c;
1150
1151                 status = nfs_try_mount(args, mntfh);
1152                 if (status)
1153                         return status;
1154
1155                 break;
1156                 }
1157         }
1158
1159         if (!(args->flags & NFS_MOUNT_SECFLAVOUR))
1160                 args->auth_flavors[0] = RPC_AUTH_UNIX;
1161
1162 #ifndef CONFIG_NFS_V3
1163         if (args->flags & NFS_MOUNT_VER3)
1164                 goto out_v3_not_compiled;
1165 #endif /* !CONFIG_NFS_V3 */
1166
1167         return 0;
1168
1169 out_no_data:
1170         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1171         return -EINVAL;
1172
1173 out_no_v3:
1174         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1175                  data->version);
1176         return -EINVAL;
1177
1178 out_no_sec:
1179         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1180         return -EINVAL;
1181
1182 #ifndef CONFIG_NFS_V3
1183 out_v3_not_compiled:
1184         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1185         return -EPROTONOSUPPORT;
1186 #endif /* !CONFIG_NFS_V3 */
1187
1188 out_no_address:
1189         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1190         return -EINVAL;
1191
1192 out_invalid_fh:
1193         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1194         return -EINVAL;
1195 }
1196
1197 /*
1198  * Initialise the common bits of the superblock
1199  */
1200 static inline void nfs_initialise_sb(struct super_block *sb)
1201 {
1202         struct nfs_server *server = NFS_SB(sb);
1203
1204         sb->s_magic = NFS_SUPER_MAGIC;
1205
1206         /* We probably want something more informative here */
1207         snprintf(sb->s_id, sizeof(sb->s_id),
1208                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1209
1210         if (sb->s_blocksize == 0)
1211                 sb->s_blocksize = nfs_block_bits(server->wsize,
1212                                                  &sb->s_blocksize_bits);
1213
1214         if (server->flags & NFS_MOUNT_NOAC)
1215                 sb->s_flags |= MS_SYNCHRONOUS;
1216
1217         nfs_super_set_maxbytes(sb, server->maxfilesize);
1218 }
1219
1220 /*
1221  * Finish setting up an NFS2/3 superblock
1222  */
1223 static void nfs_fill_super(struct super_block *sb,
1224                            struct nfs_parsed_mount_data *data)
1225 {
1226         struct nfs_server *server = NFS_SB(sb);
1227
1228         sb->s_blocksize_bits = 0;
1229         sb->s_blocksize = 0;
1230         if (data->bsize)
1231                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1232
1233         if (server->flags & NFS_MOUNT_VER3) {
1234                 /* The VFS shouldn't apply the umask to mode bits. We will do
1235                  * so ourselves when necessary.
1236                  */
1237                 sb->s_flags |= MS_POSIXACL;
1238                 sb->s_time_gran = 1;
1239         }
1240
1241         sb->s_op = &nfs_sops;
1242         nfs_initialise_sb(sb);
1243 }
1244
1245 /*
1246  * Finish setting up a cloned NFS2/3 superblock
1247  */
1248 static void nfs_clone_super(struct super_block *sb,
1249                             const struct super_block *old_sb)
1250 {
1251         struct nfs_server *server = NFS_SB(sb);
1252
1253         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1254         sb->s_blocksize = old_sb->s_blocksize;
1255         sb->s_maxbytes = old_sb->s_maxbytes;
1256
1257         if (server->flags & NFS_MOUNT_VER3) {
1258                 /* The VFS shouldn't apply the umask to mode bits. We will do
1259                  * so ourselves when necessary.
1260                  */
1261                 sb->s_flags |= MS_POSIXACL;
1262                 sb->s_time_gran = 1;
1263         }
1264
1265         sb->s_op = old_sb->s_op;
1266         nfs_initialise_sb(sb);
1267 }
1268
1269 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
1270
1271 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1272 {
1273         const struct nfs_server *a = s->s_fs_info;
1274         const struct rpc_clnt *clnt_a = a->client;
1275         const struct rpc_clnt *clnt_b = b->client;
1276
1277         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1278                 goto Ebusy;
1279         if (a->nfs_client != b->nfs_client)
1280                 goto Ebusy;
1281         if (a->flags != b->flags)
1282                 goto Ebusy;
1283         if (a->wsize != b->wsize)
1284                 goto Ebusy;
1285         if (a->rsize != b->rsize)
1286                 goto Ebusy;
1287         if (a->acregmin != b->acregmin)
1288                 goto Ebusy;
1289         if (a->acregmax != b->acregmax)
1290                 goto Ebusy;
1291         if (a->acdirmin != b->acdirmin)
1292                 goto Ebusy;
1293         if (a->acdirmax != b->acdirmax)
1294                 goto Ebusy;
1295         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1296                 goto Ebusy;
1297         return 1;
1298 Ebusy:
1299         return 0;
1300 }
1301
1302 struct nfs_sb_mountdata {
1303         struct nfs_server *server;
1304         int mntflags;
1305 };
1306
1307 static int nfs_set_super(struct super_block *s, void *data)
1308 {
1309         struct nfs_sb_mountdata *sb_mntdata = data;
1310         struct nfs_server *server = sb_mntdata->server;
1311         int ret;
1312
1313         s->s_flags = sb_mntdata->mntflags;
1314         s->s_fs_info = server;
1315         ret = set_anon_super(s, server);
1316         if (ret == 0)
1317                 server->s_dev = s->s_dev;
1318         return ret;
1319 }
1320
1321 static int nfs_compare_super(struct super_block *sb, void *data)
1322 {
1323         struct nfs_sb_mountdata *sb_mntdata = data;
1324         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1325         int mntflags = sb_mntdata->mntflags;
1326
1327         if (memcmp(&old->nfs_client->cl_addr,
1328                                 &server->nfs_client->cl_addr,
1329                                 sizeof(old->nfs_client->cl_addr)) != 0)
1330                 return 0;
1331         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1332         if (old->flags & NFS_MOUNT_UNSHARED)
1333                 return 0;
1334         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1335                 return 0;
1336         return nfs_compare_mount_options(sb, server, mntflags);
1337 }
1338
1339 static int nfs_get_sb(struct file_system_type *fs_type,
1340         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1341 {
1342         struct nfs_server *server = NULL;
1343         struct super_block *s;
1344         struct nfs_fh mntfh;
1345         struct nfs_parsed_mount_data data;
1346         struct dentry *mntroot;
1347         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1348         struct nfs_sb_mountdata sb_mntdata = {
1349                 .mntflags = flags,
1350         };
1351         int error;
1352
1353         /* Validate the mount data */
1354         error = nfs_validate_mount_data(raw_data, &data, &mntfh, dev_name);
1355         if (error < 0)
1356                 goto out;
1357
1358         /* Get a volume representation */
1359         server = nfs_create_server(&data, &mntfh);
1360         if (IS_ERR(server)) {
1361                 error = PTR_ERR(server);
1362                 goto out;
1363         }
1364         sb_mntdata.server = server;
1365
1366         if (server->flags & NFS_MOUNT_UNSHARED)
1367                 compare_super = NULL;
1368
1369         /* Get a superblock - note that we may end up sharing one that already exists */
1370         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1371         if (IS_ERR(s)) {
1372                 error = PTR_ERR(s);
1373                 goto out_err_nosb;
1374         }
1375
1376         if (s->s_fs_info != server) {
1377                 nfs_free_server(server);
1378                 server = NULL;
1379         }
1380
1381         if (!s->s_root) {
1382                 /* initial superblock/root creation */
1383                 nfs_fill_super(s, &data);
1384         }
1385
1386         mntroot = nfs_get_root(s, &mntfh);
1387         if (IS_ERR(mntroot)) {
1388                 error = PTR_ERR(mntroot);
1389                 goto error_splat_super;
1390         }
1391
1392         s->s_flags |= MS_ACTIVE;
1393         mnt->mnt_sb = s;
1394         mnt->mnt_root = mntroot;
1395         error = 0;
1396
1397 out:
1398         kfree(data.nfs_server.hostname);
1399         return error;
1400
1401 out_err_nosb:
1402         nfs_free_server(server);
1403         goto out;
1404
1405 error_splat_super:
1406         up_write(&s->s_umount);
1407         deactivate_super(s);
1408         goto out;
1409 }
1410
1411 /*
1412  * Destroy an NFS2/3 superblock
1413  */
1414 static void nfs_kill_super(struct super_block *s)
1415 {
1416         struct nfs_server *server = NFS_SB(s);
1417
1418         kill_anon_super(s);
1419         nfs_free_server(server);
1420 }
1421
1422 /*
1423  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
1424  */
1425 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
1426                            const char *dev_name, void *raw_data,
1427                            struct vfsmount *mnt)
1428 {
1429         struct nfs_clone_mount *data = raw_data;
1430         struct super_block *s;
1431         struct nfs_server *server;
1432         struct dentry *mntroot;
1433         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1434         struct nfs_sb_mountdata sb_mntdata = {
1435                 .mntflags = flags,
1436         };
1437         int error;
1438
1439         dprintk("--> nfs_xdev_get_sb()\n");
1440
1441         /* create a new volume representation */
1442         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1443         if (IS_ERR(server)) {
1444                 error = PTR_ERR(server);
1445                 goto out_err_noserver;
1446         }
1447         sb_mntdata.server = server;
1448
1449         if (server->flags & NFS_MOUNT_UNSHARED)
1450                 compare_super = NULL;
1451
1452         /* Get a superblock - note that we may end up sharing one that already exists */
1453         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1454         if (IS_ERR(s)) {
1455                 error = PTR_ERR(s);
1456                 goto out_err_nosb;
1457         }
1458
1459         if (s->s_fs_info != server) {
1460                 nfs_free_server(server);
1461                 server = NULL;
1462         }
1463
1464         if (!s->s_root) {
1465                 /* initial superblock/root creation */
1466                 nfs_clone_super(s, data->sb);
1467         }
1468
1469         mntroot = nfs_get_root(s, data->fh);
1470         if (IS_ERR(mntroot)) {
1471                 error = PTR_ERR(mntroot);
1472                 goto error_splat_super;
1473         }
1474         if (mntroot->d_inode->i_op != &nfs_dir_inode_operations) {
1475                 dput(mntroot);
1476                 error = -ESTALE;
1477                 goto error_splat_super;
1478         }
1479
1480         s->s_flags |= MS_ACTIVE;
1481         mnt->mnt_sb = s;
1482         mnt->mnt_root = mntroot;
1483
1484         dprintk("<-- nfs_xdev_get_sb() = 0\n");
1485         return 0;
1486
1487 out_err_nosb:
1488         nfs_free_server(server);
1489 out_err_noserver:
1490         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
1491         return error;
1492
1493 error_splat_super:
1494         up_write(&s->s_umount);
1495         deactivate_super(s);
1496         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
1497         return error;
1498 }
1499
1500 #ifdef CONFIG_NFS_V4
1501
1502 /*
1503  * Finish setting up a cloned NFS4 superblock
1504  */
1505 static void nfs4_clone_super(struct super_block *sb,
1506                             const struct super_block *old_sb)
1507 {
1508         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1509         sb->s_blocksize = old_sb->s_blocksize;
1510         sb->s_maxbytes = old_sb->s_maxbytes;
1511         sb->s_time_gran = 1;
1512         sb->s_op = old_sb->s_op;
1513         nfs_initialise_sb(sb);
1514 }
1515
1516 /*
1517  * Set up an NFS4 superblock
1518  */
1519 static void nfs4_fill_super(struct super_block *sb)
1520 {
1521         sb->s_time_gran = 1;
1522         sb->s_op = &nfs4_sops;
1523         nfs_initialise_sb(sb);
1524 }
1525
1526 /*
1527  * Validate NFSv4 mount options
1528  */
1529 static int nfs4_validate_mount_data(void *options,
1530                                     struct nfs_parsed_mount_data *args,
1531                                     const char *dev_name)
1532 {
1533         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
1534         char *c;
1535
1536         memset(args, 0, sizeof(*args));
1537
1538         if (data == NULL)
1539                 goto out_no_data;
1540
1541         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1542         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1543         args->timeo             = 600;
1544         args->retrans           = 2;
1545         args->acregmin          = 3;
1546         args->acregmax          = 60;
1547         args->acdirmin          = 30;
1548         args->acdirmax          = 60;
1549         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1550
1551         switch (data->version) {
1552         case 1:
1553                 if (data->host_addrlen != sizeof(args->nfs_server.address))
1554                         goto out_no_address;
1555                 if (copy_from_user(&args->nfs_server.address,
1556                                    data->host_addr,
1557                                    sizeof(args->nfs_server.address)))
1558                         return -EFAULT;
1559                 if (args->nfs_server.address.sin_port == 0)
1560                         args->nfs_server.address.sin_port = htons(NFS_PORT);
1561                 if (!nfs_verify_server_address((struct sockaddr *)
1562                                                 &args->nfs_server.address))
1563                         goto out_no_address;
1564
1565                 switch (data->auth_flavourlen) {
1566                 case 0:
1567                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1568                         break;
1569                 case 1:
1570                         if (copy_from_user(&args->auth_flavors[0],
1571                                            data->auth_flavours,
1572                                            sizeof(args->auth_flavors[0])))
1573                                 return -EFAULT;
1574                         break;
1575                 default:
1576                         goto out_inval_auth;
1577                 }
1578
1579                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1580                 if (IS_ERR(c))
1581                         return PTR_ERR(c);
1582                 args->nfs_server.hostname = c;
1583
1584                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1585                 if (IS_ERR(c))
1586                         return PTR_ERR(c);
1587                 args->nfs_server.export_path = c;
1588                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1589
1590                 c = strndup_user(data->client_addr.data, 16);
1591                 if (IS_ERR(c))
1592                         return PTR_ERR(c);
1593                 args->client_address = c;
1594
1595                 /*
1596                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
1597                  * can deal with.
1598                  */
1599
1600                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
1601                 args->rsize     = data->rsize;
1602                 args->wsize     = data->wsize;
1603                 args->timeo     = data->timeo;
1604                 args->retrans   = data->retrans;
1605                 args->acregmin  = data->acregmin;
1606                 args->acregmax  = data->acregmax;
1607                 args->acdirmin  = data->acdirmin;
1608                 args->acdirmax  = data->acdirmax;
1609                 args->nfs_server.protocol = data->proto;
1610
1611                 break;
1612         default: {
1613                 unsigned int len;
1614
1615                 if (nfs_parse_mount_options((char *)options, args) == 0)
1616                         return -EINVAL;
1617
1618                 if (!nfs_verify_server_address((struct sockaddr *)
1619                                                 &args->nfs_server.address))
1620                         return -EINVAL;
1621
1622                 switch (args->auth_flavor_len) {
1623                 case 0:
1624                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1625                         break;
1626                 case 1:
1627                         break;
1628                 default:
1629                         goto out_inval_auth;
1630                 }
1631
1632                 /*
1633                  * Split "dev_name" into "hostname:mntpath".
1634                  */
1635                 c = strchr(dev_name, ':');
1636                 if (c == NULL)
1637                         return -EINVAL;
1638                 /* while calculating len, pretend ':' is '\0' */
1639                 len = c - dev_name;
1640                 if (len > NFS4_MAXNAMLEN)
1641                         return -ENAMETOOLONG;
1642                 args->nfs_server.hostname = kzalloc(len, GFP_KERNEL);
1643                 if (args->nfs_server.hostname == NULL)
1644                         return -ENOMEM;
1645                 strncpy(args->nfs_server.hostname, dev_name, len - 1);
1646
1647                 c++;                    /* step over the ':' */
1648                 len = strlen(c);
1649                 if (len > NFS4_MAXPATHLEN)
1650                         return -ENAMETOOLONG;
1651                 args->nfs_server.export_path = kzalloc(len + 1, GFP_KERNEL);
1652                 if (args->nfs_server.export_path == NULL)
1653                         return -ENOMEM;
1654                 strncpy(args->nfs_server.export_path, c, len);
1655
1656                 dprintk("MNTPATH: %s\n", args->nfs_server.export_path);
1657
1658                 if (args->client_address == NULL)
1659                         goto out_no_client_address;
1660
1661                 break;
1662                 }
1663         }
1664
1665         return 0;
1666
1667 out_no_data:
1668         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
1669         return -EINVAL;
1670
1671 out_inval_auth:
1672         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
1673                  data->auth_flavourlen);
1674         return -EINVAL;
1675
1676 out_no_address:
1677         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
1678         return -EINVAL;
1679
1680 out_no_client_address:
1681         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
1682         return -EINVAL;
1683 }
1684
1685 /*
1686  * Get the superblock for an NFS4 mountpoint
1687  */
1688 static int nfs4_get_sb(struct file_system_type *fs_type,
1689         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1690 {
1691         struct nfs_parsed_mount_data data;
1692         struct super_block *s;
1693         struct nfs_server *server;
1694         struct nfs_fh mntfh;
1695         struct dentry *mntroot;
1696         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1697         struct nfs_sb_mountdata sb_mntdata = {
1698                 .mntflags = flags,
1699         };
1700         int error;
1701
1702         /* Validate the mount data */
1703         error = nfs4_validate_mount_data(raw_data, &data, dev_name);
1704         if (error < 0)
1705                 goto out;
1706
1707         /* Get a volume representation */
1708         server = nfs4_create_server(&data, &mntfh);
1709         if (IS_ERR(server)) {
1710                 error = PTR_ERR(server);
1711                 goto out;
1712         }
1713         sb_mntdata.server = server;
1714
1715         if (server->flags & NFS4_MOUNT_UNSHARED)
1716                 compare_super = NULL;
1717
1718         /* Get a superblock - note that we may end up sharing one that already exists */
1719         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1720         if (IS_ERR(s)) {
1721                 error = PTR_ERR(s);
1722                 goto out_free;
1723         }
1724
1725         if (s->s_fs_info != server) {
1726                 nfs_free_server(server);
1727                 server = NULL;
1728         }
1729
1730         if (!s->s_root) {
1731                 /* initial superblock/root creation */
1732                 nfs4_fill_super(s);
1733         }
1734
1735         mntroot = nfs4_get_root(s, &mntfh);
1736         if (IS_ERR(mntroot)) {
1737                 error = PTR_ERR(mntroot);
1738                 goto error_splat_super;
1739         }
1740
1741         s->s_flags |= MS_ACTIVE;
1742         mnt->mnt_sb = s;
1743         mnt->mnt_root = mntroot;
1744         error = 0;
1745
1746 out:
1747         kfree(data.client_address);
1748         kfree(data.nfs_server.export_path);
1749         kfree(data.nfs_server.hostname);
1750         return error;
1751
1752 out_free:
1753         nfs_free_server(server);
1754         goto out;
1755
1756 error_splat_super:
1757         up_write(&s->s_umount);
1758         deactivate_super(s);
1759         goto out;
1760 }
1761
1762 static void nfs4_kill_super(struct super_block *sb)
1763 {
1764         struct nfs_server *server = NFS_SB(sb);
1765
1766         nfs_return_all_delegations(sb);
1767         kill_anon_super(sb);
1768
1769         nfs4_renewd_prepare_shutdown(server);
1770         nfs_free_server(server);
1771 }
1772
1773 /*
1774  * Clone an NFS4 server record on xdev traversal (FSID-change)
1775  */
1776 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
1777                             const char *dev_name, void *raw_data,
1778                             struct vfsmount *mnt)
1779 {
1780         struct nfs_clone_mount *data = raw_data;
1781         struct super_block *s;
1782         struct nfs_server *server;
1783         struct dentry *mntroot;
1784         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1785         struct nfs_sb_mountdata sb_mntdata = {
1786                 .mntflags = flags,
1787         };
1788         int error;
1789
1790         dprintk("--> nfs4_xdev_get_sb()\n");
1791
1792         /* create a new volume representation */
1793         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1794         if (IS_ERR(server)) {
1795                 error = PTR_ERR(server);
1796                 goto out_err_noserver;
1797         }
1798         sb_mntdata.server = server;
1799
1800         if (server->flags & NFS4_MOUNT_UNSHARED)
1801                 compare_super = NULL;
1802
1803         /* Get a superblock - note that we may end up sharing one that already exists */
1804         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1805         if (IS_ERR(s)) {
1806                 error = PTR_ERR(s);
1807                 goto out_err_nosb;
1808         }
1809
1810         if (s->s_fs_info != server) {
1811                 nfs_free_server(server);
1812                 server = NULL;
1813         }
1814
1815         if (!s->s_root) {
1816                 /* initial superblock/root creation */
1817                 nfs4_clone_super(s, data->sb);
1818         }
1819
1820         mntroot = nfs4_get_root(s, data->fh);
1821         if (IS_ERR(mntroot)) {
1822                 error = PTR_ERR(mntroot);
1823                 goto error_splat_super;
1824         }
1825
1826         s->s_flags |= MS_ACTIVE;
1827         mnt->mnt_sb = s;
1828         mnt->mnt_root = mntroot;
1829
1830         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
1831         return 0;
1832
1833 out_err_nosb:
1834         nfs_free_server(server);
1835 out_err_noserver:
1836         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
1837         return error;
1838
1839 error_splat_super:
1840         up_write(&s->s_umount);
1841         deactivate_super(s);
1842         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
1843         return error;
1844 }
1845
1846 /*
1847  * Create an NFS4 server record on referral traversal
1848  */
1849 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
1850                                 const char *dev_name, void *raw_data,
1851                                 struct vfsmount *mnt)
1852 {
1853         struct nfs_clone_mount *data = raw_data;
1854         struct super_block *s;
1855         struct nfs_server *server;
1856         struct dentry *mntroot;
1857         struct nfs_fh mntfh;
1858         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1859         struct nfs_sb_mountdata sb_mntdata = {
1860                 .mntflags = flags,
1861         };
1862         int error;
1863
1864         dprintk("--> nfs4_referral_get_sb()\n");
1865
1866         /* create a new volume representation */
1867         server = nfs4_create_referral_server(data, &mntfh);
1868         if (IS_ERR(server)) {
1869                 error = PTR_ERR(server);
1870                 goto out_err_noserver;
1871         }
1872         sb_mntdata.server = server;
1873
1874         if (server->flags & NFS4_MOUNT_UNSHARED)
1875                 compare_super = NULL;
1876
1877         /* Get a superblock - note that we may end up sharing one that already exists */
1878         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1879         if (IS_ERR(s)) {
1880                 error = PTR_ERR(s);
1881                 goto out_err_nosb;
1882         }
1883
1884         if (s->s_fs_info != server) {
1885                 nfs_free_server(server);
1886                 server = NULL;
1887         }
1888
1889         if (!s->s_root) {
1890                 /* initial superblock/root creation */
1891                 nfs4_fill_super(s);
1892         }
1893
1894         mntroot = nfs4_get_root(s, &mntfh);
1895         if (IS_ERR(mntroot)) {
1896                 error = PTR_ERR(mntroot);
1897                 goto error_splat_super;
1898         }
1899
1900         s->s_flags |= MS_ACTIVE;
1901         mnt->mnt_sb = s;
1902         mnt->mnt_root = mntroot;
1903
1904         dprintk("<-- nfs4_referral_get_sb() = 0\n");
1905         return 0;
1906
1907 out_err_nosb:
1908         nfs_free_server(server);
1909 out_err_noserver:
1910         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
1911         return error;
1912
1913 error_splat_super:
1914         up_write(&s->s_umount);
1915         deactivate_super(s);
1916         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
1917         return error;
1918 }
1919
1920 #endif /* CONFIG_NFS_V4 */