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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/nfs_xdr.h>
  51 #include <linux/magic.h>
  52 #include <linux/parser.h>
  53
  54 #include <asm/system.h>
  55 #include <asm/uaccess.h>
  56
  57 #include "nfs4_fs.h"
  58 #include "callback.h"
  59 #include "delegation.h"
  60 #include "iostat.h"
  61 #include "internal.h"
  62
  63 #define NFSDBG_FACILITY         NFSDBG_VFS
  64
  65 enum {
  66         /* Mount options that take no arguments */
  67         Opt_soft, Opt_hard,
  68         Opt_intr, Opt_nointr,
  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         /* Mount options that are ignored */
  96         Opt_userspace, Opt_deprecated,
  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_soft, "soft" },
 105         { Opt_hard, "hard" },
 106         { Opt_intr, "intr" },
 107         { Opt_nointr, "nointr" },
 108         { Opt_posix, "posix" },
 109         { Opt_noposix, "noposix" },
 110         { Opt_cto, "cto" },
 111         { Opt_nocto, "nocto" },
 112         { Opt_ac, "ac" },
 113         { Opt_noac, "noac" },
 114         { Opt_lock, "lock" },
 115         { Opt_nolock, "nolock" },
 116         { Opt_v2, "v2" },
 117         { Opt_v3, "v3" },
 118         { Opt_udp, "udp" },
 119         { Opt_tcp, "tcp" },
 120         { Opt_rdma, "rdma" },
 121         { Opt_acl, "acl" },
 122         { Opt_noacl, "noacl" },
 123         { Opt_rdirplus, "rdirplus" },
 124         { Opt_nordirplus, "nordirplus" },
 125         { Opt_sharecache, "sharecache" },
 126         { Opt_nosharecache, "nosharecache" },
 127
 128         { Opt_port, "port=%u" },
 129         { Opt_rsize, "rsize=%u" },
 130         { Opt_wsize, "wsize=%u" },
 131         { Opt_bsize, "bsize=%u" },
 132         { Opt_timeo, "timeo=%u" },
 133         { Opt_retrans, "retrans=%u" },
 134         { Opt_acregmin, "acregmin=%u" },
 135         { Opt_acregmax, "acregmax=%u" },
 136         { Opt_acdirmin, "acdirmin=%u" },
 137         { Opt_acdirmax, "acdirmax=%u" },
 138         { Opt_actimeo, "actimeo=%u" },
 139         { Opt_userspace, "retry=%u" },
 140         { Opt_namelen, "namlen=%u" },
 141         { Opt_mountport, "mountport=%u" },
 142         { Opt_mountvers, "mountvers=%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_mounthost, "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 static void nfs_put_super(struct super_block *);
 206
 207 static struct file_system_type nfs_fs_type = {
 208         .owner          = THIS_MODULE,
 209         .name           = "nfs",
 210         .get_sb         = nfs_get_sb,
 211         .kill_sb        = nfs_kill_super,
 212         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 213 };
 214
 215 struct file_system_type nfs_xdev_fs_type = {
 216         .owner          = THIS_MODULE,
 217         .name           = "nfs",
 218         .get_sb         = nfs_xdev_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 static const struct super_operations nfs_sops = {
 224         .alloc_inode    = nfs_alloc_inode,
 225         .destroy_inode  = nfs_destroy_inode,
 226         .write_inode    = nfs_write_inode,
 227         .put_super      = nfs_put_super,
 228         .statfs         = nfs_statfs,
 229         .clear_inode    = nfs_clear_inode,
 230         .umount_begin   = nfs_umount_begin,
 231         .show_options   = nfs_show_options,
 232         .show_stats     = nfs_show_stats,
 233 };
 234
 235 #ifdef CONFIG_NFS_V4
 236 static int nfs4_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_xdev_get_sb(struct file_system_type *fs_type,
 239         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 240 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 241         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 242 static void nfs4_kill_super(struct super_block *sb);
 243
 244 static struct file_system_type nfs4_fs_type = {
 245         .owner          = THIS_MODULE,
 246         .name           = "nfs4",
 247         .get_sb         = nfs4_get_sb,
 248         .kill_sb        = nfs4_kill_super,
 249         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 250 };
 251
 252 struct file_system_type nfs4_xdev_fs_type = {
 253         .owner          = THIS_MODULE,
 254         .name           = "nfs4",
 255         .get_sb         = nfs4_xdev_get_sb,
 256         .kill_sb        = nfs4_kill_super,
 257         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 258 };
 259
 260 struct file_system_type nfs4_referral_fs_type = {
 261         .owner          = THIS_MODULE,
 262         .name           = "nfs4",
 263         .get_sb         = nfs4_referral_get_sb,
 264         .kill_sb        = nfs4_kill_super,
 265         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 266 };
 267
 268 static const struct super_operations nfs4_sops = {
 269         .alloc_inode    = nfs_alloc_inode,
 270         .destroy_inode  = nfs_destroy_inode,
 271         .write_inode    = nfs_write_inode,
 272         .statfs         = nfs_statfs,
 273         .clear_inode    = nfs4_clear_inode,
 274         .umount_begin   = nfs_umount_begin,
 275         .show_options   = nfs_show_options,
 276         .show_stats     = nfs_show_stats,
 277 };
 278 #endif
 279
 280 static struct shrinker acl_shrinker = {
 281         .shrink         = nfs_access_cache_shrinker,
 282         .seeks          = DEFAULT_SEEKS,
 283 };
 284
 285 /*
 286  * Register the NFS filesystems
 287  */
 288 int __init register_nfs_fs(void)
 289 {
 290         int ret;
 291
 292         ret = register_filesystem(&nfs_fs_type);
 293         if (ret < 0)
 294                 goto error_0;
 295
 296         ret = nfs_register_sysctl();
 297         if (ret < 0)
 298                 goto error_1;
 299 #ifdef CONFIG_NFS_V4
 300         ret = register_filesystem(&nfs4_fs_type);
 301         if (ret < 0)
 302                 goto error_2;
 303 #endif
 304         register_shrinker(&acl_shrinker);
 305         return 0;
 306
 307 #ifdef CONFIG_NFS_V4
 308 error_2:
 309         nfs_unregister_sysctl();
 310 #endif
 311 error_1:
 312         unregister_filesystem(&nfs_fs_type);
 313 error_0:
 314         return ret;
 315 }
 316
 317 /*
 318  * Unregister the NFS filesystems
 319  */
 320 void __exit unregister_nfs_fs(void)
 321 {
 322         unregister_shrinker(&acl_shrinker);
 323 #ifdef CONFIG_NFS_V4
 324         unregister_filesystem(&nfs4_fs_type);
 325 #endif
 326         nfs_unregister_sysctl();
 327         unregister_filesystem(&nfs_fs_type);
 328 }
 329
 330 void nfs_sb_active(struct nfs_server *server)
 331 {
 332         atomic_inc(&server->active);
 333 }
 334
 335 void nfs_sb_deactive(struct nfs_server *server)
 336 {
 337         if (atomic_dec_and_test(&server->active))
 338                 wake_up(&server->active_wq);
 339 }
 340
 341 static void nfs_put_super(struct super_block *sb)
 342 {
 343         struct nfs_server *server = NFS_SB(sb);
 344         /*
 345          * Make sure there are no outstanding ops to this server.
 346          * If so, wait for them to finish before allowing the
 347          * unmount to continue.
 348          */
 349         wait_event(server->active_wq, atomic_read(&server->active) == 0);
 350 }
 351
 352 /*
 353  * Deliver file system statistics to userspace
 354  */
 355 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 356 {
 357         struct nfs_server *server = NFS_SB(dentry->d_sb);
 358         unsigned char blockbits;
 359         unsigned long blockres;
 360         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 361         struct nfs_fattr fattr;
 362         struct nfs_fsstat res = {
 363                         .fattr = &fattr,
 364         };
 365         int error;
 366
 367         lock_kernel();
 368
 369         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 370         if (error < 0)
 371                 goto out_err;
 372         buf->f_type = NFS_SUPER_MAGIC;
 373
 374         /*
 375          * Current versions of glibc do not correctly handle the
 376          * case where f_frsize != f_bsize.  Eventually we want to
 377          * report the value of wtmult in this field.
 378          */
 379         buf->f_frsize = dentry->d_sb->s_blocksize;
 380
 381         /*
 382          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 383          * are reported in units of f_frsize.  Linux hasn't had
 384          * an f_frsize field in its statfs struct until recently,
 385          * thus historically Linux's sys_statfs reports these
 386          * fields in units of f_bsize.
 387          */
 388         buf->f_bsize = dentry->d_sb->s_blocksize;
 389         blockbits = dentry->d_sb->s_blocksize_bits;
 390         blockres = (1 << blockbits) - 1;
 391         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 392         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 393         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 394
 395         buf->f_files = res.tfiles;
 396         buf->f_ffree = res.afiles;
 397
 398         buf->f_namelen = server->namelen;
 399
 400         unlock_kernel();
 401         return 0;
 402
 403  out_err:
 404         dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
 405         unlock_kernel();
 406         return error;
 407 }
 408
 409 /*
 410  * Map the security flavour number to a name
 411  */
 412 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 413 {
 414         static const struct {
 415                 rpc_authflavor_t flavour;
 416                 const char *str;
 417         } sec_flavours[] = {
 418                 { RPC_AUTH_NULL, "null" },
 419                 { RPC_AUTH_UNIX, "sys" },
 420                 { RPC_AUTH_GSS_KRB5, "krb5" },
 421                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 422                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 423                 { RPC_AUTH_GSS_LKEY, "lkey" },
 424                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 425                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 426                 { RPC_AUTH_GSS_SPKM, "spkm" },
 427                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 428                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 429                 { UINT_MAX, "unknown" }
 430         };
 431         int i;
 432
 433         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 434                 if (sec_flavours[i].flavour == flavour)
 435                         break;
 436         }
 437         return sec_flavours[i].str;
 438 }
 439
 440 /*
 441  * Describe the mount options in force on this server representation
 442  */
 443 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
 444 {
 445         static const struct proc_nfs_info {
 446                 int flag;
 447                 const char *str;
 448                 const char *nostr;
 449         } nfs_info[] = {
 450                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 451                 { NFS_MOUNT_INTR, ",intr", ",nointr" },
 452                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 453                 { NFS_MOUNT_NOAC, ",noac", "" },
 454                 { NFS_MOUNT_NONLM, ",nolock", "" },
 455                 { NFS_MOUNT_NOACL, ",noacl", "" },
 456                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 457                 { NFS_MOUNT_UNSHARED, ",nosharecache", ""},
 458                 { 0, NULL, NULL }
 459         };
 460         const struct proc_nfs_info *nfs_infop;
 461         struct nfs_client *clp = nfss->nfs_client;
 462
 463         seq_printf(m, ",vers=%d", clp->rpc_ops->version);
 464         seq_printf(m, ",rsize=%d", nfss->rsize);
 465         seq_printf(m, ",wsize=%d", nfss->wsize);
 466         if (nfss->acregmin != 3*HZ || showdefaults)
 467                 seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
 468         if (nfss->acregmax != 60*HZ || showdefaults)
 469                 seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
 470         if (nfss->acdirmin != 30*HZ || showdefaults)
 471                 seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
 472         if (nfss->acdirmax != 60*HZ || showdefaults)
 473                 seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
 474         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 475                 if (nfss->flags & nfs_infop->flag)
 476                         seq_puts(m, nfs_infop->str);
 477                 else
 478                         seq_puts(m, nfs_infop->nostr);
 479         }
 480         seq_printf(m, ",proto=%s",
 481                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 482         seq_printf(m, ",timeo=%lu", 10U * clp->retrans_timeo / HZ);
 483         seq_printf(m, ",retrans=%u", clp->retrans_count);
 484         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 485 }
 486
 487 /*
 488  * Describe the mount options on this VFS mountpoint
 489  */
 490 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 491 {
 492         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 493
 494         nfs_show_mount_options(m, nfss, 0);
 495
 496         seq_printf(m, ",addr=%s",
 497                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 498                                                         RPC_DISPLAY_ADDR));
 499
 500         return 0;
 501 }
 502
 503 /*
 504  * Present statistical information for this VFS mountpoint
 505  */
 506 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 507 {
 508         int i, cpu;
 509         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 510         struct rpc_auth *auth = nfss->client->cl_auth;
 511         struct nfs_iostats totals = { };
 512
 513         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 514
 515         /*
 516          * Display all mount option settings
 517          */
 518         seq_printf(m, "\n\topts:\t");
 519         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 520         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 521         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 522         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 523         nfs_show_mount_options(m, nfss, 1);
 524
 525         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 526
 527         seq_printf(m, "\n\tcaps:\t");
 528         seq_printf(m, "caps=0x%x", nfss->caps);
 529         seq_printf(m, ",wtmult=%d", nfss->wtmult);
 530         seq_printf(m, ",dtsize=%d", nfss->dtsize);
 531         seq_printf(m, ",bsize=%d", nfss->bsize);
 532         seq_printf(m, ",namelen=%d", nfss->namelen);
 533
 534 #ifdef CONFIG_NFS_V4
 535         if (nfss->nfs_client->rpc_ops->version == 4) {
 536                 seq_printf(m, "\n\tnfsv4:\t");
 537                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 538                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 539                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 540         }
 541 #endif
 542
 543         /*
 544          * Display security flavor in effect for this mount
 545          */
 546         seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
 547         if (auth->au_flavor)
 548                 seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
 549
 550         /*
 551          * Display superblock I/O counters
 552          */
 553         for_each_possible_cpu(cpu) {
 554                 struct nfs_iostats *stats;
 555
 556                 preempt_disable();
 557                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 558
 559                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 560                         totals.events[i] += stats->events[i];
 561                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 562                         totals.bytes[i] += stats->bytes[i];
 563
 564                 preempt_enable();
 565         }
 566
 567         seq_printf(m, "\n\tevents:\t");
 568         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 569                 seq_printf(m, "%lu ", totals.events[i]);
 570         seq_printf(m, "\n\tbytes:\t");
 571         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 572                 seq_printf(m, "%Lu ", totals.bytes[i]);
 573         seq_printf(m, "\n");
 574
 575         rpc_print_iostats(m, nfss->client);
 576
 577         return 0;
 578 }
 579
 580 /*
 581  * Begin unmount by attempting to remove all automounted mountpoints we added
 582  * in response to xdev traversals and referrals
 583  */
 584 static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
 585 {
 586         struct nfs_server *server = NFS_SB(vfsmnt->mnt_sb);
 587         struct rpc_clnt *rpc;
 588
 589         shrink_submounts(vfsmnt, &nfs_automount_list);
 590
 591         if (!(flags & MNT_FORCE))
 592                 return;
 593         /* -EIO all pending I/O */
 594         rpc = server->client_acl;
 595         if (!IS_ERR(rpc))
 596                 rpc_killall_tasks(rpc);
 597         rpc = server->client;
 598         if (!IS_ERR(rpc))
 599                 rpc_killall_tasks(rpc);
 600 }
 601
 602 /*
 603  * Set the port number in an address.  Be agnostic about the address family.
 604  */
 605 static void nfs_set_port(struct sockaddr *sap, unsigned short port)
 606 {
 607         switch (sap->sa_family) {
 608         case AF_INET: {
 609                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
 610                 ap->sin_port = htons(port);
 611                 break;
 612         }
 613         case AF_INET6: {
 614                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
 615                 ap->sin6_port = htons(port);
 616                 break;
 617         }
 618         }
 619 }
 620
 621 /*
 622  * Sanity-check a server address provided by the mount command.
 623  *
 624  * Address family must be initialized, and address must not be
 625  * the ANY address for that family.
 626  */
 627 static int nfs_verify_server_address(struct sockaddr *addr)
 628 {
 629         switch (addr->sa_family) {
 630         case AF_INET: {
 631                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 632                 return sa->sin_addr.s_addr != INADDR_ANY;
 633         }
 634         case AF_INET6: {
 635                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 636                 return !ipv6_addr_any(sa);
 637         }
 638         }
 639
 640         return 0;
 641 }
 642
 643 /*
 644  * Parse string addresses passed in via a mount option,
 645  * and construct a sockaddr based on the result.
 646  *
 647  * If address parsing fails, set the sockaddr's address
 648  * family to AF_UNSPEC to force nfs_verify_server_address()
 649  * to punt the mount.
 650  */
 651 static void nfs_parse_server_address(char *value,
 652                                      struct sockaddr *sap)
 653 {
 654         struct sockaddr_in *ap = (void *)sap;
 655
 656         ap->sin_family = AF_INET;
 657         if (in4_pton(value, -1, (u8 *)&ap->sin_addr.s_addr, '\0', NULL))
 658                 return;
 659
 660         sap->sa_family = AF_UNSPEC;
 661 }
 662
 663 /*
 664  * Error-check and convert a string of mount options from user space into
 665  * a data structure
 666  */
 667 static int nfs_parse_mount_options(char *raw,
 668                                    struct nfs_parsed_mount_data *mnt)
 669 {
 670         char *p, *string;
 671         unsigned short port = 0;
 672
 673         if (!raw) {
 674                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 675                 return 1;
 676         }
 677         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 678
 679         while ((p = strsep(&raw, ",")) != NULL) {
 680                 substring_t args[MAX_OPT_ARGS];
 681                 int option, token;
 682
 683                 if (!*p)
 684                         continue;
 685
 686                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 687
 688                 token = match_token(p, nfs_mount_option_tokens, args);
 689                 switch (token) {
 690                 case Opt_soft:
 691                         mnt->flags |= NFS_MOUNT_SOFT;
 692                         break;
 693                 case Opt_hard:
 694                         mnt->flags &= ~NFS_MOUNT_SOFT;
 695                         break;
 696                 case Opt_intr:
 697                         mnt->flags |= NFS_MOUNT_INTR;
 698                         break;
 699                 case Opt_nointr:
 700                         mnt->flags &= ~NFS_MOUNT_INTR;
 701                         break;
 702                 case Opt_posix:
 703                         mnt->flags |= NFS_MOUNT_POSIX;
 704                         break;
 705                 case Opt_noposix:
 706                         mnt->flags &= ~NFS_MOUNT_POSIX;
 707                         break;
 708                 case Opt_cto:
 709                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 710                         break;
 711                 case Opt_nocto:
 712                         mnt->flags |= NFS_MOUNT_NOCTO;
 713                         break;
 714                 case Opt_ac:
 715                         mnt->flags &= ~NFS_MOUNT_NOAC;
 716                         break;
 717                 case Opt_noac:
 718                         mnt->flags |= NFS_MOUNT_NOAC;
 719                         break;
 720                 case Opt_lock:
 721                         mnt->flags &= ~NFS_MOUNT_NONLM;
 722                         break;
 723                 case Opt_nolock:
 724                         mnt->flags |= NFS_MOUNT_NONLM;
 725                         break;
 726                 case Opt_v2:
 727                         mnt->flags &= ~NFS_MOUNT_VER3;
 728                         break;
 729                 case Opt_v3:
 730                         mnt->flags |= NFS_MOUNT_VER3;
 731                         break;
 732                 case Opt_udp:
 733                         mnt->flags &= ~NFS_MOUNT_TCP;
 734                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 735                         mnt->timeo = 7;
 736                         mnt->retrans = 5;
 737                         break;
 738                 case Opt_tcp:
 739                         mnt->flags |= NFS_MOUNT_TCP;
 740                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 741                         mnt->timeo = 600;
 742                         mnt->retrans = 2;
 743                         break;
 744                 case Opt_rdma:
 745                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 746                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 747                         mnt->timeo = 600;
 748                         mnt->retrans = 2;
 749                         break;
 750                 case Opt_acl:
 751                         mnt->flags &= ~NFS_MOUNT_NOACL;
 752                         break;
 753                 case Opt_noacl:
 754                         mnt->flags |= NFS_MOUNT_NOACL;
 755                         break;
 756                 case Opt_rdirplus:
 757                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 758                         break;
 759                 case Opt_nordirplus:
 760                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 761                         break;
 762                 case Opt_sharecache:
 763                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 764                         break;
 765                 case Opt_nosharecache:
 766                         mnt->flags |= NFS_MOUNT_UNSHARED;
 767                         break;
 768
 769                 case Opt_port:
 770                         if (match_int(args, &option))
 771                                 return 0;
 772                         if (option < 0 || option > 65535)
 773                                 return 0;
 774                         port = option;
 775                         break;
 776                 case Opt_rsize:
 777                         if (match_int(args, &mnt->rsize))
 778                                 return 0;
 779                         break;
 780                 case Opt_wsize:
 781                         if (match_int(args, &mnt->wsize))
 782                                 return 0;
 783                         break;
 784                 case Opt_bsize:
 785                         if (match_int(args, &option))
 786                                 return 0;
 787                         if (option < 0)
 788                                 return 0;
 789                         mnt->bsize = option;
 790                         break;
 791                 case Opt_timeo:
 792                         if (match_int(args, &mnt->timeo))
 793                                 return 0;
 794                         break;
 795                 case Opt_retrans:
 796                         if (match_int(args, &mnt->retrans))
 797                                 return 0;
 798                         break;
 799                 case Opt_acregmin:
 800                         if (match_int(args, &mnt->acregmin))
 801                                 return 0;
 802                         break;
 803                 case Opt_acregmax:
 804                         if (match_int(args, &mnt->acregmax))
 805                                 return 0;
 806                         break;
 807                 case Opt_acdirmin:
 808                         if (match_int(args, &mnt->acdirmin))
 809                                 return 0;
 810                         break;
 811                 case Opt_acdirmax:
 812                         if (match_int(args, &mnt->acdirmax))
 813                                 return 0;
 814                         break;
 815                 case Opt_actimeo:
 816                         if (match_int(args, &option))
 817                                 return 0;
 818                         if (option < 0)
 819                                 return 0;
 820                         mnt->acregmin =
 821                         mnt->acregmax =
 822                         mnt->acdirmin =
 823                         mnt->acdirmax = option;
 824                         break;
 825                 case Opt_namelen:
 826                         if (match_int(args, &mnt->namlen))
 827                                 return 0;
 828                         break;
 829                 case Opt_mountport:
 830                         if (match_int(args, &option))
 831                                 return 0;
 832                         if (option < 0 || option > 65535)
 833                                 return 0;
 834                         mnt->mount_server.port = option;
 835                         break;
 836                 case Opt_mountvers:
 837                         if (match_int(args, &option))
 838                                 return 0;
 839                         if (option < 0)
 840                                 return 0;
 841                         mnt->mount_server.version = option;
 842                         break;
 843                 case Opt_nfsvers:
 844                         if (match_int(args, &option))
 845                                 return 0;
 846                         switch (option) {
 847                         case 2:
 848                                 mnt->flags &= ~NFS_MOUNT_VER3;
 849                                 break;
 850                         case 3:
 851                                 mnt->flags |= NFS_MOUNT_VER3;
 852                                 break;
 853                         default:
 854                                 goto out_unrec_vers;
 855                         }
 856                         break;
 857
 858                 case Opt_sec:
 859                         string = match_strdup(args);
 860                         if (string == NULL)
 861                                 goto out_nomem;
 862                         token = match_token(string, nfs_secflavor_tokens, args);
 863                         kfree(string);
 864
 865                         /*
 866                          * The flags setting is for v2/v3.  The flavor_len
 867                          * setting is for v4.  v2/v3 also need to know the
 868                          * difference between NULL and UNIX.
 869                          */
 870                         switch (token) {
 871                         case Opt_sec_none:
 872                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
 873                                 mnt->auth_flavor_len = 0;
 874                                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 875                                 break;
 876                         case Opt_sec_sys:
 877                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
 878                                 mnt->auth_flavor_len = 0;
 879                                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 880                                 break;
 881                         case Opt_sec_krb5:
 882                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 883                                 mnt->auth_flavor_len = 1;
 884                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 885                                 break;
 886                         case Opt_sec_krb5i:
 887                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 888                                 mnt->auth_flavor_len = 1;
 889                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 890                                 break;
 891                         case Opt_sec_krb5p:
 892                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 893                                 mnt->auth_flavor_len = 1;
 894                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 895                                 break;
 896                         case Opt_sec_lkey:
 897                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 898                                 mnt->auth_flavor_len = 1;
 899                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 900                                 break;
 901                         case Opt_sec_lkeyi:
 902                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 903                                 mnt->auth_flavor_len = 1;
 904                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 905                                 break;
 906                         case Opt_sec_lkeyp:
 907                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 908                                 mnt->auth_flavor_len = 1;
 909                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 910                                 break;
 911                         case Opt_sec_spkm:
 912                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 913                                 mnt->auth_flavor_len = 1;
 914                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 915                                 break;
 916                         case Opt_sec_spkmi:
 917                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 918                                 mnt->auth_flavor_len = 1;
 919                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 920                                 break;
 921                         case Opt_sec_spkmp:
 922                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 923                                 mnt->auth_flavor_len = 1;
 924                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 925                                 break;
 926                         default:
 927                                 goto out_unrec_sec;
 928                         }
 929                         break;
 930                 case Opt_proto:
 931                         string = match_strdup(args);
 932                         if (string == NULL)
 933                                 goto out_nomem;
 934                         token = match_token(string,
 935                                             nfs_xprt_protocol_tokens, args);
 936                         kfree(string);
 937
 938                         switch (token) {
 939                         case Opt_xprt_udp:
 940                                 mnt->flags &= ~NFS_MOUNT_TCP;
 941                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 942                                 mnt->timeo = 7;
 943                                 mnt->retrans = 5;
 944                                 break;
 945                         case Opt_xprt_tcp:
 946                                 mnt->flags |= NFS_MOUNT_TCP;
 947                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 948                                 mnt->timeo = 600;
 949                                 mnt->retrans = 2;
 950                                 break;
 951                         case Opt_xprt_rdma:
 952                                 /* vector side protocols to TCP */
 953                                 mnt->flags |= NFS_MOUNT_TCP;
 954                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 955                                 mnt->timeo = 600;
 956                                 mnt->retrans = 2;
 957                                 break;
 958                         default:
 959                                 goto out_unrec_xprt;
 960                         }
 961                         break;
 962                 case Opt_mountproto:
 963                         string = match_strdup(args);
 964                         if (string == NULL)
 965                                 goto out_nomem;
 966                         token = match_token(string,
 967                                             nfs_xprt_protocol_tokens, args);
 968                         kfree(string);
 969
 970                         switch (token) {
 971                         case Opt_xprt_udp:
 972                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 973                                 break;
 974                         case Opt_xprt_tcp:
 975                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 976                                 break;
 977                         case Opt_xprt_rdma: /* not used for side protocols */
 978                         default:
 979                                 goto out_unrec_xprt;
 980                         }
 981                         break;
 982                 case Opt_addr:
 983                         string = match_strdup(args);
 984                         if (string == NULL)
 985                                 goto out_nomem;
 986                         nfs_parse_server_address(string, (struct sockaddr *)
 987                                                  &mnt->nfs_server.address);
 988                         kfree(string);
 989                         break;
 990                 case Opt_clientaddr:
 991                         string = match_strdup(args);
 992                         if (string == NULL)
 993                                 goto out_nomem;
 994                         mnt->client_address = string;
 995                         break;
 996                 case Opt_mounthost:
 997                         string = match_strdup(args);
 998                         if (string == NULL)
 999                                 goto out_nomem;
1000                         mnt->mount_server.hostname = string;
1001                         break;
1002                 case Opt_mountaddr:
1003                         string = match_strdup(args);
1004                         if (string == NULL)
1005                                 goto out_nomem;
1006                         nfs_parse_server_address(string, (struct sockaddr *)
1007                                                  &mnt->mount_server.address);
1008                         kfree(string);
1009                         break;
1010
1011                 case Opt_userspace:
1012                 case Opt_deprecated:
1013                         break;
1014
1015                 default:
1016                         goto out_unknown;
1017                 }
1018         }
1019
1020         nfs_set_port((struct sockaddr *)&mnt->nfs_server.address, port);
1021
1022         return 1;
1023
1024 out_nomem:
1025         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1026         return 0;
1027
1028 out_unrec_vers:
1029         printk(KERN_INFO "NFS: unrecognized NFS version number\n");
1030         return 0;
1031
1032 out_unrec_xprt:
1033         printk(KERN_INFO "NFS: unrecognized transport protocol\n");
1034         return 0;
1035
1036 out_unrec_sec:
1037         printk(KERN_INFO "NFS: unrecognized security flavor\n");
1038         return 0;
1039
1040 out_unknown:
1041         printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
1042         return 0;
1043 }
1044
1045 /*
1046  * Use the remote server's MOUNT service to request the NFS file handle
1047  * corresponding to the provided path.
1048  */
1049 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1050                          struct nfs_fh *root_fh)
1051 {
1052         struct sockaddr_in sin;
1053         int status;
1054         char *hostname;
1055
1056         if (args->mount_server.version == 0) {
1057                 if (args->flags & NFS_MOUNT_VER3)
1058                         args->mount_server.version = NFS_MNT3_VERSION;
1059                 else
1060                         args->mount_server.version = NFS_MNT_VERSION;
1061         }
1062
1063         if (args->mount_server.hostname)
1064                 hostname = args->mount_server.hostname;
1065         else
1066                 hostname = args->nfs_server.hostname;
1067
1068         /*
1069          * Construct the mount server's address.
1070          */
1071         if (args->mount_server.address.sin_addr.s_addr != INADDR_ANY)
1072                 sin = args->mount_server.address;
1073         else
1074                 sin = args->nfs_server.address;
1075         /*
1076          * autobind will be used if mount_server.port == 0
1077          */
1078         nfs_set_port((struct sockaddr *)&sin, args->mount_server.port);
1079
1080         /*
1081          * Now ask the mount server to map our export path
1082          * to a file handle.
1083          */
1084         status = nfs_mount((struct sockaddr *) &sin,
1085                            sizeof(sin),
1086                            hostname,
1087                            args->nfs_server.export_path,
1088                            args->mount_server.version,
1089                            args->mount_server.protocol,
1090                            root_fh);
1091         if (status == 0)
1092                 return 0;
1093
1094         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d",
1095                         hostname, status);
1096         return status;
1097 }
1098
1099 /*
1100  * Validate the NFS2/NFS3 mount data
1101  * - fills in the mount root filehandle
1102  *
1103  * For option strings, user space handles the following behaviors:
1104  *
1105  * + DNS: mapping server host name to IP address ("addr=" option)
1106  *
1107  * + failure mode: how to behave if a mount request can't be handled
1108  *   immediately ("fg/bg" option)
1109  *
1110  * + retry: how often to retry a mount request ("retry=" option)
1111  *
1112  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1113  *   mountproto=tcp after mountproto=udp, and so on
1114  */
1115 static int nfs_validate_mount_data(void *options,
1116                                    struct nfs_parsed_mount_data *args,
1117                                    struct nfs_fh *mntfh,
1118                                    const char *dev_name)
1119 {
1120         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1121
1122         memset(args, 0, sizeof(*args));
1123
1124         if (data == NULL)
1125                 goto out_no_data;
1126
1127         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1128         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1129         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1130         args->timeo             = 600;
1131         args->retrans           = 2;
1132         args->acregmin          = 3;
1133         args->acregmax          = 60;
1134         args->acdirmin          = 30;
1135         args->acdirmax          = 60;
1136         args->mount_server.protocol = XPRT_TRANSPORT_UDP;
1137         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1138
1139         switch (data->version) {
1140         case 1:
1141                 data->namlen = 0;
1142         case 2:
1143                 data->bsize = 0;
1144         case 3:
1145                 if (data->flags & NFS_MOUNT_VER3)
1146                         goto out_no_v3;
1147                 data->root.size = NFS2_FHSIZE;
1148                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1149         case 4:
1150                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1151                         goto out_no_sec;
1152         case 5:
1153                 memset(data->context, 0, sizeof(data->context));
1154         case 6:
1155                 if (data->flags & NFS_MOUNT_VER3)
1156                         mntfh->size = data->root.size;
1157                 else
1158                         mntfh->size = NFS2_FHSIZE;
1159
1160                 if (mntfh->size > sizeof(mntfh->data))
1161                         goto out_invalid_fh;
1162
1163                 memcpy(mntfh->data, data->root.data, mntfh->size);
1164                 if (mntfh->size < sizeof(mntfh->data))
1165                         memset(mntfh->data + mntfh->size, 0,
1166                                sizeof(mntfh->data) - mntfh->size);
1167
1168                 if (!nfs_verify_server_address((struct sockaddr *) &data->addr))
1169                         goto out_no_address;
1170
1171                 /*
1172                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1173                  * can deal with.
1174                  */
1175                 args->flags             = data->flags;
1176                 args->rsize             = data->rsize;
1177                 args->wsize             = data->wsize;
1178                 args->flags             = data->flags;
1179                 args->timeo             = data->timeo;
1180                 args->retrans           = data->retrans;
1181                 args->acregmin          = data->acregmin;
1182                 args->acregmax          = data->acregmax;
1183                 args->acdirmin          = data->acdirmin;
1184                 args->acdirmax          = data->acdirmax;
1185                 args->nfs_server.address = data->addr;
1186                 if (!(data->flags & NFS_MOUNT_TCP))
1187                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1188                 /* N.B. caller will free nfs_server.hostname in all cases */
1189                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1190                 args->namlen            = data->namlen;
1191                 args->bsize             = data->bsize;
1192                 args->auth_flavors[0]   = data->pseudoflavor;
1193                 break;
1194         default: {
1195                 unsigned int len;
1196                 char *c;
1197                 int status;
1198
1199                 if (nfs_parse_mount_options((char *)options, args) == 0)
1200                         return -EINVAL;
1201
1202                 if (!nfs_verify_server_address((struct sockaddr *)
1203                                                 &args->nfs_server.address))
1204                         goto out_no_address;
1205
1206                 c = strchr(dev_name, ':');
1207                 if (c == NULL)
1208                         return -EINVAL;
1209                 len = c - dev_name;
1210                 /* N.B. caller will free nfs_server.hostname in all cases */
1211                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1212
1213                 c++;
1214                 if (strlen(c) > NFS_MAXPATHLEN)
1215                         return -ENAMETOOLONG;
1216                 args->nfs_server.export_path = c;
1217
1218                 status = nfs_try_mount(args, mntfh);
1219                 if (status)
1220                         return status;
1221
1222                 break;
1223                 }
1224         }
1225
1226         if (!(args->flags & NFS_MOUNT_SECFLAVOUR))
1227                 args->auth_flavors[0] = RPC_AUTH_UNIX;
1228
1229 #ifndef CONFIG_NFS_V3
1230         if (args->flags & NFS_MOUNT_VER3)
1231                 goto out_v3_not_compiled;
1232 #endif /* !CONFIG_NFS_V3 */
1233
1234         return 0;
1235
1236 out_no_data:
1237         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1238         return -EINVAL;
1239
1240 out_no_v3:
1241         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1242                  data->version);
1243         return -EINVAL;
1244
1245 out_no_sec:
1246         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1247         return -EINVAL;
1248
1249 #ifndef CONFIG_NFS_V3
1250 out_v3_not_compiled:
1251         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1252         return -EPROTONOSUPPORT;
1253 #endif /* !CONFIG_NFS_V3 */
1254
1255 out_no_address:
1256         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1257         return -EINVAL;
1258
1259 out_invalid_fh:
1260         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1261         return -EINVAL;
1262 }
1263
1264 /*
1265  * Initialise the common bits of the superblock
1266  */
1267 static inline void nfs_initialise_sb(struct super_block *sb)
1268 {
1269         struct nfs_server *server = NFS_SB(sb);
1270
1271         sb->s_magic = NFS_SUPER_MAGIC;
1272
1273         /* We probably want something more informative here */
1274         snprintf(sb->s_id, sizeof(sb->s_id),
1275                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1276
1277         if (sb->s_blocksize == 0)
1278                 sb->s_blocksize = nfs_block_bits(server->wsize,
1279                                                  &sb->s_blocksize_bits);
1280
1281         if (server->flags & NFS_MOUNT_NOAC)
1282                 sb->s_flags |= MS_SYNCHRONOUS;
1283
1284         nfs_super_set_maxbytes(sb, server->maxfilesize);
1285 }
1286
1287 /*
1288  * Finish setting up an NFS2/3 superblock
1289  */
1290 static void nfs_fill_super(struct super_block *sb,
1291                            struct nfs_parsed_mount_data *data)
1292 {
1293         struct nfs_server *server = NFS_SB(sb);
1294
1295         sb->s_blocksize_bits = 0;
1296         sb->s_blocksize = 0;
1297         if (data->bsize)
1298                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1299
1300         if (server->flags & NFS_MOUNT_VER3) {
1301                 /* The VFS shouldn't apply the umask to mode bits. We will do
1302                  * so ourselves when necessary.
1303                  */
1304                 sb->s_flags |= MS_POSIXACL;
1305                 sb->s_time_gran = 1;
1306         }
1307
1308         sb->s_op = &nfs_sops;
1309         nfs_initialise_sb(sb);
1310 }
1311
1312 /*
1313  * Finish setting up a cloned NFS2/3 superblock
1314  */
1315 static void nfs_clone_super(struct super_block *sb,
1316                             const struct super_block *old_sb)
1317 {
1318         struct nfs_server *server = NFS_SB(sb);
1319
1320         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1321         sb->s_blocksize = old_sb->s_blocksize;
1322         sb->s_maxbytes = old_sb->s_maxbytes;
1323
1324         if (server->flags & NFS_MOUNT_VER3) {
1325                 /* The VFS shouldn't apply the umask to mode bits. We will do
1326                  * so ourselves when necessary.
1327                  */
1328                 sb->s_flags |= MS_POSIXACL;
1329                 sb->s_time_gran = 1;
1330         }
1331
1332         sb->s_op = old_sb->s_op;
1333         nfs_initialise_sb(sb);
1334 }
1335
1336 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
1337
1338 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1339 {
1340         const struct nfs_server *a = s->s_fs_info;
1341         const struct rpc_clnt *clnt_a = a->client;
1342         const struct rpc_clnt *clnt_b = b->client;
1343
1344         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1345                 goto Ebusy;
1346         if (a->nfs_client != b->nfs_client)
1347                 goto Ebusy;
1348         if (a->flags != b->flags)
1349                 goto Ebusy;
1350         if (a->wsize != b->wsize)
1351                 goto Ebusy;
1352         if (a->rsize != b->rsize)
1353                 goto Ebusy;
1354         if (a->acregmin != b->acregmin)
1355                 goto Ebusy;
1356         if (a->acregmax != b->acregmax)
1357                 goto Ebusy;
1358         if (a->acdirmin != b->acdirmin)
1359                 goto Ebusy;
1360         if (a->acdirmax != b->acdirmax)
1361                 goto Ebusy;
1362         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1363                 goto Ebusy;
1364         return 1;
1365 Ebusy:
1366         return 0;
1367 }
1368
1369 struct nfs_sb_mountdata {
1370         struct nfs_server *server;
1371         int mntflags;
1372 };
1373
1374 static int nfs_set_super(struct super_block *s, void *data)
1375 {
1376         struct nfs_sb_mountdata *sb_mntdata = data;
1377         struct nfs_server *server = sb_mntdata->server;
1378         int ret;
1379
1380         s->s_flags = sb_mntdata->mntflags;
1381         s->s_fs_info = server;
1382         ret = set_anon_super(s, server);
1383         if (ret == 0)
1384                 server->s_dev = s->s_dev;
1385         return ret;
1386 }
1387
1388 static int nfs_compare_super_address(struct nfs_server *server1,
1389                                      struct nfs_server *server2)
1390 {
1391         struct sockaddr *sap1, *sap2;
1392
1393         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1394         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1395
1396         if (sap1->sa_family != sap2->sa_family)
1397                 return 0;
1398
1399         switch (sap1->sa_family) {
1400         case AF_INET: {
1401                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1402                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1403                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1404                         return 0;
1405                 if (sin1->sin_port != sin2->sin_port)
1406                         return 0;
1407                 break;
1408         }
1409         case AF_INET6: {
1410                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1411                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1412                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1413                         return 0;
1414                 if (sin1->sin6_port != sin2->sin6_port)
1415                         return 0;
1416                 break;
1417         }
1418         default:
1419                 return 0;
1420         }
1421
1422         return 1;
1423 }
1424
1425 static int nfs_compare_super(struct super_block *sb, void *data)
1426 {
1427         struct nfs_sb_mountdata *sb_mntdata = data;
1428         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1429         int mntflags = sb_mntdata->mntflags;
1430
1431         if (!nfs_compare_super_address(old, server))
1432                 return 0;
1433         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1434         if (old->flags & NFS_MOUNT_UNSHARED)
1435                 return 0;
1436         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1437                 return 0;
1438         return nfs_compare_mount_options(sb, server, mntflags);
1439 }
1440
1441 static int nfs_get_sb(struct file_system_type *fs_type,
1442         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1443 {
1444         struct nfs_server *server = NULL;
1445         struct super_block *s;
1446         struct nfs_fh mntfh;
1447         struct nfs_parsed_mount_data data;
1448         struct dentry *mntroot;
1449         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1450         struct nfs_sb_mountdata sb_mntdata = {
1451                 .mntflags = flags,
1452         };
1453         int error;
1454
1455         /* Validate the mount data */
1456         error = nfs_validate_mount_data(raw_data, &data, &mntfh, dev_name);
1457         if (error < 0)
1458                 goto out;
1459
1460         /* Get a volume representation */
1461         server = nfs_create_server(&data, &mntfh);
1462         if (IS_ERR(server)) {
1463                 error = PTR_ERR(server);
1464                 goto out;
1465         }
1466         sb_mntdata.server = server;
1467
1468         if (server->flags & NFS_MOUNT_UNSHARED)
1469                 compare_super = NULL;
1470
1471         /* Get a superblock - note that we may end up sharing one that already exists */
1472         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1473         if (IS_ERR(s)) {
1474                 error = PTR_ERR(s);
1475                 goto out_err_nosb;
1476         }
1477
1478         if (s->s_fs_info != server) {
1479                 nfs_free_server(server);
1480                 server = NULL;
1481         }
1482
1483         if (!s->s_root) {
1484                 /* initial superblock/root creation */
1485                 nfs_fill_super(s, &data);
1486         }
1487
1488         mntroot = nfs_get_root(s, &mntfh);
1489         if (IS_ERR(mntroot)) {
1490                 error = PTR_ERR(mntroot);
1491                 goto error_splat_super;
1492         }
1493
1494         s->s_flags |= MS_ACTIVE;
1495         mnt->mnt_sb = s;
1496         mnt->mnt_root = mntroot;
1497         error = 0;
1498
1499 out:
1500         kfree(data.nfs_server.hostname);
1501         kfree(data.mount_server.hostname);
1502         return error;
1503
1504 out_err_nosb:
1505         nfs_free_server(server);
1506         goto out;
1507
1508 error_splat_super:
1509         up_write(&s->s_umount);
1510         deactivate_super(s);
1511         goto out;
1512 }
1513
1514 /*
1515  * Destroy an NFS2/3 superblock
1516  */
1517 static void nfs_kill_super(struct super_block *s)
1518 {
1519         struct nfs_server *server = NFS_SB(s);
1520
1521         kill_anon_super(s);
1522         nfs_free_server(server);
1523 }
1524
1525 /*
1526  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
1527  */
1528 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
1529                            const char *dev_name, void *raw_data,
1530                            struct vfsmount *mnt)
1531 {
1532         struct nfs_clone_mount *data = raw_data;
1533         struct super_block *s;
1534         struct nfs_server *server;
1535         struct dentry *mntroot;
1536         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1537         struct nfs_sb_mountdata sb_mntdata = {
1538                 .mntflags = flags,
1539         };
1540         int error;
1541
1542         dprintk("--> nfs_xdev_get_sb()\n");
1543
1544         /* create a new volume representation */
1545         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1546         if (IS_ERR(server)) {
1547                 error = PTR_ERR(server);
1548                 goto out_err_noserver;
1549         }
1550         sb_mntdata.server = server;
1551
1552         if (server->flags & NFS_MOUNT_UNSHARED)
1553                 compare_super = NULL;
1554
1555         /* Get a superblock - note that we may end up sharing one that already exists */
1556         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1557         if (IS_ERR(s)) {
1558                 error = PTR_ERR(s);
1559                 goto out_err_nosb;
1560         }
1561
1562         if (s->s_fs_info != server) {
1563                 nfs_free_server(server);
1564                 server = NULL;
1565         }
1566
1567         if (!s->s_root) {
1568                 /* initial superblock/root creation */
1569                 nfs_clone_super(s, data->sb);
1570         }
1571
1572         mntroot = nfs_get_root(s, data->fh);
1573         if (IS_ERR(mntroot)) {
1574                 error = PTR_ERR(mntroot);
1575                 goto error_splat_super;
1576         }
1577         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1578                 dput(mntroot);
1579                 error = -ESTALE;
1580                 goto error_splat_super;
1581         }
1582
1583         s->s_flags |= MS_ACTIVE;
1584         mnt->mnt_sb = s;
1585         mnt->mnt_root = mntroot;
1586
1587         dprintk("<-- nfs_xdev_get_sb() = 0\n");
1588         return 0;
1589
1590 out_err_nosb:
1591         nfs_free_server(server);
1592 out_err_noserver:
1593         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
1594         return error;
1595
1596 error_splat_super:
1597         up_write(&s->s_umount);
1598         deactivate_super(s);
1599         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
1600         return error;
1601 }
1602
1603 #ifdef CONFIG_NFS_V4
1604
1605 /*
1606  * Finish setting up a cloned NFS4 superblock
1607  */
1608 static void nfs4_clone_super(struct super_block *sb,
1609                             const struct super_block *old_sb)
1610 {
1611         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1612         sb->s_blocksize = old_sb->s_blocksize;
1613         sb->s_maxbytes = old_sb->s_maxbytes;
1614         sb->s_time_gran = 1;
1615         sb->s_op = old_sb->s_op;
1616         nfs_initialise_sb(sb);
1617 }
1618
1619 /*
1620  * Set up an NFS4 superblock
1621  */
1622 static void nfs4_fill_super(struct super_block *sb)
1623 {
1624         sb->s_time_gran = 1;
1625         sb->s_op = &nfs4_sops;
1626         nfs_initialise_sb(sb);
1627 }
1628
1629 /*
1630  * If the user didn't specify a port, set the port number to
1631  * the NFS version 4 default port.
1632  */
1633 static void nfs4_default_port(struct sockaddr *sap)
1634 {
1635         switch (sap->sa_family) {
1636         case AF_INET: {
1637                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
1638                 if (ap->sin_port == 0)
1639                         ap->sin_port = htons(NFS_PORT);
1640                 break;
1641         }
1642         case AF_INET6: {
1643                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
1644                 if (ap->sin6_port == 0)
1645                         ap->sin6_port = htons(NFS_PORT);
1646                 break;
1647         }
1648         }
1649 }
1650
1651 /*
1652  * Validate NFSv4 mount options
1653  */
1654 static int nfs4_validate_mount_data(void *options,
1655                                     struct nfs_parsed_mount_data *args,
1656                                     const char *dev_name)
1657 {
1658         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
1659         char *c;
1660
1661         memset(args, 0, sizeof(*args));
1662
1663         if (data == NULL)
1664                 goto out_no_data;
1665
1666         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1667         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1668         args->timeo             = 600;
1669         args->retrans           = 2;
1670         args->acregmin          = 3;
1671         args->acregmax          = 60;
1672         args->acdirmin          = 30;
1673         args->acdirmax          = 60;
1674         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1675
1676         switch (data->version) {
1677         case 1:
1678                 if (data->host_addrlen != sizeof(args->nfs_server.address))
1679                         goto out_no_address;
1680                 if (copy_from_user(&args->nfs_server.address,
1681                                    data->host_addr,
1682                                    sizeof(args->nfs_server.address)))
1683                         return -EFAULT;
1684                 if (!nfs_verify_server_address((struct sockaddr *)
1685                                                 &args->nfs_server.address))
1686                         goto out_no_address;
1687
1688                 nfs4_default_port((struct sockaddr *)
1689                                   &args->nfs_server.address);
1690
1691                 switch (data->auth_flavourlen) {
1692                 case 0:
1693                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1694                         break;
1695                 case 1:
1696                         if (copy_from_user(&args->auth_flavors[0],
1697                                            data->auth_flavours,
1698                                            sizeof(args->auth_flavors[0])))
1699                                 return -EFAULT;
1700                         break;
1701                 default:
1702                         goto out_inval_auth;
1703                 }
1704
1705                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1706                 if (IS_ERR(c))
1707                         return PTR_ERR(c);
1708                 args->nfs_server.hostname = c;
1709
1710                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1711                 if (IS_ERR(c))
1712                         return PTR_ERR(c);
1713                 args->nfs_server.export_path = c;
1714                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1715
1716                 c = strndup_user(data->client_addr.data, 16);
1717                 if (IS_ERR(c))
1718                         return PTR_ERR(c);
1719                 args->client_address = c;
1720
1721                 /*
1722                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
1723                  * can deal with.
1724                  */
1725
1726                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
1727                 args->rsize     = data->rsize;
1728                 args->wsize     = data->wsize;
1729                 args->timeo     = data->timeo;
1730                 args->retrans   = data->retrans;
1731                 args->acregmin  = data->acregmin;
1732                 args->acregmax  = data->acregmax;
1733                 args->acdirmin  = data->acdirmin;
1734                 args->acdirmax  = data->acdirmax;
1735                 args->nfs_server.protocol = data->proto;
1736
1737                 break;
1738         default: {
1739                 unsigned int len;
1740
1741                 if (nfs_parse_mount_options((char *)options, args) == 0)
1742                         return -EINVAL;
1743
1744                 if (!nfs_verify_server_address((struct sockaddr *)
1745                                                 &args->nfs_server.address))
1746                         return -EINVAL;
1747
1748                 nfs4_default_port((struct sockaddr *)
1749                                   &args->nfs_server.address);
1750
1751                 switch (args->auth_flavor_len) {
1752                 case 0:
1753                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1754                         break;
1755                 case 1:
1756                         break;
1757                 default:
1758                         goto out_inval_auth;
1759                 }
1760
1761                 /*
1762                  * Split "dev_name" into "hostname:mntpath".
1763                  */
1764                 c = strchr(dev_name, ':');
1765                 if (c == NULL)
1766                         return -EINVAL;
1767                 /* while calculating len, pretend ':' is '\0' */
1768                 len = c - dev_name;
1769                 if (len > NFS4_MAXNAMLEN)
1770                         return -ENAMETOOLONG;
1771                 /* N.B. caller will free nfs_server.hostname in all cases */
1772                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1773
1774                 c++;                    /* step over the ':' */
1775                 len = strlen(c);
1776                 if (len > NFS4_MAXPATHLEN)
1777                         return -ENAMETOOLONG;
1778                 args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
1779
1780                 dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
1781
1782                 if (args->client_address == NULL)
1783                         goto out_no_client_address;
1784
1785                 break;
1786                 }
1787         }
1788
1789         return 0;
1790
1791 out_no_data:
1792         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
1793         return -EINVAL;
1794
1795 out_inval_auth:
1796         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
1797                  data->auth_flavourlen);
1798         return -EINVAL;
1799
1800 out_no_address:
1801         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
1802         return -EINVAL;
1803
1804 out_no_client_address:
1805         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
1806         return -EINVAL;
1807 }
1808
1809 /*
1810  * Get the superblock for an NFS4 mountpoint
1811  */
1812 static int nfs4_get_sb(struct file_system_type *fs_type,
1813         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1814 {
1815         struct nfs_parsed_mount_data data;
1816         struct super_block *s;
1817         struct nfs_server *server;
1818         struct nfs_fh mntfh;
1819         struct dentry *mntroot;
1820         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1821         struct nfs_sb_mountdata sb_mntdata = {
1822                 .mntflags = flags,
1823         };
1824         int error;
1825
1826         /* Validate the mount data */
1827         error = nfs4_validate_mount_data(raw_data, &data, dev_name);
1828         if (error < 0)
1829                 goto out;
1830
1831         /* Get a volume representation */
1832         server = nfs4_create_server(&data, &mntfh);
1833         if (IS_ERR(server)) {
1834                 error = PTR_ERR(server);
1835                 goto out;
1836         }
1837         sb_mntdata.server = server;
1838
1839         if (server->flags & NFS4_MOUNT_UNSHARED)
1840                 compare_super = NULL;
1841
1842         /* Get a superblock - note that we may end up sharing one that already exists */
1843         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1844         if (IS_ERR(s)) {
1845                 error = PTR_ERR(s);
1846                 goto out_free;
1847         }
1848
1849         if (s->s_fs_info != server) {
1850                 nfs_free_server(server);
1851                 server = NULL;
1852         }
1853
1854         if (!s->s_root) {
1855                 /* initial superblock/root creation */
1856                 nfs4_fill_super(s);
1857         }
1858
1859         mntroot = nfs4_get_root(s, &mntfh);
1860         if (IS_ERR(mntroot)) {
1861                 error = PTR_ERR(mntroot);
1862                 goto error_splat_super;
1863         }
1864
1865         s->s_flags |= MS_ACTIVE;
1866         mnt->mnt_sb = s;
1867         mnt->mnt_root = mntroot;
1868         error = 0;
1869
1870 out:
1871         kfree(data.client_address);
1872         kfree(data.nfs_server.export_path);
1873         kfree(data.nfs_server.hostname);
1874         return error;
1875
1876 out_free:
1877         nfs_free_server(server);
1878         goto out;
1879
1880 error_splat_super:
1881         up_write(&s->s_umount);
1882         deactivate_super(s);
1883         goto out;
1884 }
1885
1886 static void nfs4_kill_super(struct super_block *sb)
1887 {
1888         struct nfs_server *server = NFS_SB(sb);
1889
1890         nfs_return_all_delegations(sb);
1891         kill_anon_super(sb);
1892
1893         nfs4_renewd_prepare_shutdown(server);
1894         nfs_free_server(server);
1895 }
1896
1897 /*
1898  * Clone an NFS4 server record on xdev traversal (FSID-change)
1899  */
1900 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
1901                             const char *dev_name, void *raw_data,
1902                             struct vfsmount *mnt)
1903 {
1904         struct nfs_clone_mount *data = raw_data;
1905         struct super_block *s;
1906         struct nfs_server *server;
1907         struct dentry *mntroot;
1908         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1909         struct nfs_sb_mountdata sb_mntdata = {
1910                 .mntflags = flags,
1911         };
1912         int error;
1913
1914         dprintk("--> nfs4_xdev_get_sb()\n");
1915
1916         /* create a new volume representation */
1917         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1918         if (IS_ERR(server)) {
1919                 error = PTR_ERR(server);
1920                 goto out_err_noserver;
1921         }
1922         sb_mntdata.server = server;
1923
1924         if (server->flags & NFS4_MOUNT_UNSHARED)
1925                 compare_super = NULL;
1926
1927         /* Get a superblock - note that we may end up sharing one that already exists */
1928         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1929         if (IS_ERR(s)) {
1930                 error = PTR_ERR(s);
1931                 goto out_err_nosb;
1932         }
1933
1934         if (s->s_fs_info != server) {
1935                 nfs_free_server(server);
1936                 server = NULL;
1937         }
1938
1939         if (!s->s_root) {
1940                 /* initial superblock/root creation */
1941                 nfs4_clone_super(s, data->sb);
1942         }
1943
1944         mntroot = nfs4_get_root(s, data->fh);
1945         if (IS_ERR(mntroot)) {
1946                 error = PTR_ERR(mntroot);
1947                 goto error_splat_super;
1948         }
1949         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1950                 dput(mntroot);
1951                 error = -ESTALE;
1952                 goto error_splat_super;
1953         }
1954
1955         s->s_flags |= MS_ACTIVE;
1956         mnt->mnt_sb = s;
1957         mnt->mnt_root = mntroot;
1958
1959         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
1960         return 0;
1961
1962 out_err_nosb:
1963         nfs_free_server(server);
1964 out_err_noserver:
1965         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
1966         return error;
1967
1968 error_splat_super:
1969         up_write(&s->s_umount);
1970         deactivate_super(s);
1971         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
1972         return error;
1973 }
1974
1975 /*
1976  * Create an NFS4 server record on referral traversal
1977  */
1978 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
1979                                 const char *dev_name, void *raw_data,
1980                                 struct vfsmount *mnt)
1981 {
1982         struct nfs_clone_mount *data = raw_data;
1983         struct super_block *s;
1984         struct nfs_server *server;
1985         struct dentry *mntroot;
1986         struct nfs_fh mntfh;
1987         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1988         struct nfs_sb_mountdata sb_mntdata = {
1989                 .mntflags = flags,
1990         };
1991         int error;
1992
1993         dprintk("--> nfs4_referral_get_sb()\n");
1994
1995         /* create a new volume representation */
1996         server = nfs4_create_referral_server(data, &mntfh);
1997         if (IS_ERR(server)) {
1998                 error = PTR_ERR(server);
1999                 goto out_err_noserver;
2000         }
2001         sb_mntdata.server = server;
2002
2003         if (server->flags & NFS4_MOUNT_UNSHARED)
2004                 compare_super = NULL;
2005
2006         /* Get a superblock - note that we may end up sharing one that already exists */
2007         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2008         if (IS_ERR(s)) {
2009                 error = PTR_ERR(s);
2010                 goto out_err_nosb;
2011         }
2012
2013         if (s->s_fs_info != server) {
2014                 nfs_free_server(server);
2015                 server = NULL;
2016         }
2017
2018         if (!s->s_root) {
2019                 /* initial superblock/root creation */
2020                 nfs4_fill_super(s);
2021         }
2022
2023         mntroot = nfs4_get_root(s, &mntfh);
2024         if (IS_ERR(mntroot)) {
2025                 error = PTR_ERR(mntroot);
2026                 goto error_splat_super;
2027         }
2028         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2029                 dput(mntroot);
2030                 error = -ESTALE;
2031                 goto error_splat_super;
2032         }
2033
2034         s->s_flags |= MS_ACTIVE;
2035         mnt->mnt_sb = s;
2036         mnt->mnt_root = mntroot;
2037
2038         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2039         return 0;
2040
2041 out_err_nosb:
2042         nfs_free_server(server);
2043 out_err_noserver:
2044         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2045         return error;
2046
2047 error_splat_super:
2048         up_write(&s->s_umount);
2049         deactivate_super(s);
2050         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2051         return error;
2052 }
2053
2054 #endif /* CONFIG_NFS_V4 */