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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,
  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_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 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  * Error-check and convert a string of mount options from user space into
 645  * a data structure
 646  */
 647 static int nfs_parse_mount_options(char *raw,
 648                                    struct nfs_parsed_mount_data *mnt)
 649 {
 650         char *p, *string;
 651         unsigned short port = 0;
 652
 653         if (!raw) {
 654                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 655                 return 1;
 656         }
 657         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 658
 659         while ((p = strsep(&raw, ",")) != NULL) {
 660                 substring_t args[MAX_OPT_ARGS];
 661                 int option, token;
 662
 663                 if (!*p)
 664                         continue;
 665
 666                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 667
 668                 token = match_token(p, nfs_mount_option_tokens, args);
 669                 switch (token) {
 670                 case Opt_soft:
 671                         mnt->flags |= NFS_MOUNT_SOFT;
 672                         break;
 673                 case Opt_hard:
 674                         mnt->flags &= ~NFS_MOUNT_SOFT;
 675                         break;
 676                 case Opt_intr:
 677                         mnt->flags |= NFS_MOUNT_INTR;
 678                         break;
 679                 case Opt_nointr:
 680                         mnt->flags &= ~NFS_MOUNT_INTR;
 681                         break;
 682                 case Opt_posix:
 683                         mnt->flags |= NFS_MOUNT_POSIX;
 684                         break;
 685                 case Opt_noposix:
 686                         mnt->flags &= ~NFS_MOUNT_POSIX;
 687                         break;
 688                 case Opt_cto:
 689                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 690                         break;
 691                 case Opt_nocto:
 692                         mnt->flags |= NFS_MOUNT_NOCTO;
 693                         break;
 694                 case Opt_ac:
 695                         mnt->flags &= ~NFS_MOUNT_NOAC;
 696                         break;
 697                 case Opt_noac:
 698                         mnt->flags |= NFS_MOUNT_NOAC;
 699                         break;
 700                 case Opt_lock:
 701                         mnt->flags &= ~NFS_MOUNT_NONLM;
 702                         break;
 703                 case Opt_nolock:
 704                         mnt->flags |= NFS_MOUNT_NONLM;
 705                         break;
 706                 case Opt_v2:
 707                         mnt->flags &= ~NFS_MOUNT_VER3;
 708                         break;
 709                 case Opt_v3:
 710                         mnt->flags |= NFS_MOUNT_VER3;
 711                         break;
 712                 case Opt_udp:
 713                         mnt->flags &= ~NFS_MOUNT_TCP;
 714                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 715                         mnt->timeo = 7;
 716                         mnt->retrans = 5;
 717                         break;
 718                 case Opt_tcp:
 719                         mnt->flags |= NFS_MOUNT_TCP;
 720                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 721                         mnt->timeo = 600;
 722                         mnt->retrans = 2;
 723                         break;
 724                 case Opt_rdma:
 725                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 726                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 727                         mnt->timeo = 600;
 728                         mnt->retrans = 2;
 729                         break;
 730                 case Opt_acl:
 731                         mnt->flags &= ~NFS_MOUNT_NOACL;
 732                         break;
 733                 case Opt_noacl:
 734                         mnt->flags |= NFS_MOUNT_NOACL;
 735                         break;
 736                 case Opt_rdirplus:
 737                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 738                         break;
 739                 case Opt_nordirplus:
 740                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 741                         break;
 742                 case Opt_sharecache:
 743                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 744                         break;
 745                 case Opt_nosharecache:
 746                         mnt->flags |= NFS_MOUNT_UNSHARED;
 747                         break;
 748
 749                 case Opt_port:
 750                         if (match_int(args, &option))
 751                                 return 0;
 752                         if (option < 0 || option > 65535)
 753                                 return 0;
 754                         port = option;
 755                         break;
 756                 case Opt_rsize:
 757                         if (match_int(args, &mnt->rsize))
 758                                 return 0;
 759                         break;
 760                 case Opt_wsize:
 761                         if (match_int(args, &mnt->wsize))
 762                                 return 0;
 763                         break;
 764                 case Opt_bsize:
 765                         if (match_int(args, &option))
 766                                 return 0;
 767                         if (option < 0)
 768                                 return 0;
 769                         mnt->bsize = option;
 770                         break;
 771                 case Opt_timeo:
 772                         if (match_int(args, &mnt->timeo))
 773                                 return 0;
 774                         break;
 775                 case Opt_retrans:
 776                         if (match_int(args, &mnt->retrans))
 777                                 return 0;
 778                         break;
 779                 case Opt_acregmin:
 780                         if (match_int(args, &mnt->acregmin))
 781                                 return 0;
 782                         break;
 783                 case Opt_acregmax:
 784                         if (match_int(args, &mnt->acregmax))
 785                                 return 0;
 786                         break;
 787                 case Opt_acdirmin:
 788                         if (match_int(args, &mnt->acdirmin))
 789                                 return 0;
 790                         break;
 791                 case Opt_acdirmax:
 792                         if (match_int(args, &mnt->acdirmax))
 793                                 return 0;
 794                         break;
 795                 case Opt_actimeo:
 796                         if (match_int(args, &option))
 797                                 return 0;
 798                         if (option < 0)
 799                                 return 0;
 800                         mnt->acregmin =
 801                         mnt->acregmax =
 802                         mnt->acdirmin =
 803                         mnt->acdirmax = option;
 804                         break;
 805                 case Opt_namelen:
 806                         if (match_int(args, &mnt->namlen))
 807                                 return 0;
 808                         break;
 809                 case Opt_mountport:
 810                         if (match_int(args, &option))
 811                                 return 0;
 812                         if (option < 0 || option > 65535)
 813                                 return 0;
 814                         mnt->mount_server.port = option;
 815                         break;
 816                 case Opt_mountvers:
 817                         if (match_int(args, &option))
 818                                 return 0;
 819                         if (option < 0)
 820                                 return 0;
 821                         mnt->mount_server.version = option;
 822                         break;
 823                 case Opt_nfsvers:
 824                         if (match_int(args, &option))
 825                                 return 0;
 826                         switch (option) {
 827                         case 2:
 828                                 mnt->flags &= ~NFS_MOUNT_VER3;
 829                                 break;
 830                         case 3:
 831                                 mnt->flags |= NFS_MOUNT_VER3;
 832                                 break;
 833                         default:
 834                                 goto out_unrec_vers;
 835                         }
 836                         break;
 837
 838                 case Opt_sec:
 839                         string = match_strdup(args);
 840                         if (string == NULL)
 841                                 goto out_nomem;
 842                         token = match_token(string, nfs_secflavor_tokens, args);
 843                         kfree(string);
 844
 845                         /*
 846                          * The flags setting is for v2/v3.  The flavor_len
 847                          * setting is for v4.  v2/v3 also need to know the
 848                          * difference between NULL and UNIX.
 849                          */
 850                         switch (token) {
 851                         case Opt_sec_none:
 852                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
 853                                 mnt->auth_flavor_len = 0;
 854                                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 855                                 break;
 856                         case Opt_sec_sys:
 857                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
 858                                 mnt->auth_flavor_len = 0;
 859                                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 860                                 break;
 861                         case Opt_sec_krb5:
 862                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 863                                 mnt->auth_flavor_len = 1;
 864                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 865                                 break;
 866                         case Opt_sec_krb5i:
 867                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 868                                 mnt->auth_flavor_len = 1;
 869                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 870                                 break;
 871                         case Opt_sec_krb5p:
 872                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 873                                 mnt->auth_flavor_len = 1;
 874                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 875                                 break;
 876                         case Opt_sec_lkey:
 877                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 878                                 mnt->auth_flavor_len = 1;
 879                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 880                                 break;
 881                         case Opt_sec_lkeyi:
 882                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 883                                 mnt->auth_flavor_len = 1;
 884                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 885                                 break;
 886                         case Opt_sec_lkeyp:
 887                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 888                                 mnt->auth_flavor_len = 1;
 889                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 890                                 break;
 891                         case Opt_sec_spkm:
 892                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 893                                 mnt->auth_flavor_len = 1;
 894                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 895                                 break;
 896                         case Opt_sec_spkmi:
 897                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 898                                 mnt->auth_flavor_len = 1;
 899                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 900                                 break;
 901                         case Opt_sec_spkmp:
 902                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
 903                                 mnt->auth_flavor_len = 1;
 904                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 905                                 break;
 906                         default:
 907                                 goto out_unrec_sec;
 908                         }
 909                         break;
 910                 case Opt_proto:
 911                         string = match_strdup(args);
 912                         if (string == NULL)
 913                                 goto out_nomem;
 914                         token = match_token(string,
 915                                             nfs_xprt_protocol_tokens, args);
 916                         kfree(string);
 917
 918                         switch (token) {
 919                         case Opt_xprt_udp:
 920                                 mnt->flags &= ~NFS_MOUNT_TCP;
 921                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 922                                 mnt->timeo = 7;
 923                                 mnt->retrans = 5;
 924                                 break;
 925                         case Opt_xprt_tcp:
 926                                 mnt->flags |= NFS_MOUNT_TCP;
 927                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 928                                 mnt->timeo = 600;
 929                                 mnt->retrans = 2;
 930                                 break;
 931                         case Opt_xprt_rdma:
 932                                 /* vector side protocols to TCP */
 933                                 mnt->flags |= NFS_MOUNT_TCP;
 934                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 935                                 mnt->timeo = 600;
 936                                 mnt->retrans = 2;
 937                                 break;
 938                         default:
 939                                 goto out_unrec_xprt;
 940                         }
 941                         break;
 942                 case Opt_mountproto:
 943                         string = match_strdup(args);
 944                         if (string == NULL)
 945                                 goto out_nomem;
 946                         token = match_token(string,
 947                                             nfs_xprt_protocol_tokens, args);
 948                         kfree(string);
 949
 950                         switch (token) {
 951                         case Opt_xprt_udp:
 952                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 953                                 break;
 954                         case Opt_xprt_tcp:
 955                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 956                                 break;
 957                         case Opt_xprt_rdma: /* not used for side protocols */
 958                         default:
 959                                 goto out_unrec_xprt;
 960                         }
 961                         break;
 962                 case Opt_addr:
 963                         string = match_strdup(args);
 964                         if (string == NULL)
 965                                 goto out_nomem;
 966                         mnt->nfs_server.address.sin_family = AF_INET;
 967                         mnt->nfs_server.address.sin_addr.s_addr =
 968                                                         in_aton(string);
 969                         kfree(string);
 970                         break;
 971                 case Opt_clientaddr:
 972                         string = match_strdup(args);
 973                         if (string == NULL)
 974                                 goto out_nomem;
 975                         mnt->client_address = string;
 976                         break;
 977                 case Opt_mountaddr:
 978                         string = match_strdup(args);
 979                         if (string == NULL)
 980                                 goto out_nomem;
 981                         mnt->mount_server.address.sin_family = AF_INET;
 982                         mnt->mount_server.address.sin_addr.s_addr =
 983                                                         in_aton(string);
 984                         kfree(string);
 985                         break;
 986
 987                 case Opt_userspace:
 988                 case Opt_deprecated:
 989                         break;
 990
 991                 default:
 992                         goto out_unknown;
 993                 }
 994         }
 995
 996         nfs_set_port((struct sockaddr *)&mnt->nfs_server.address, port);
 997
 998         return 1;
 999
1000 out_nomem:
1001         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1002         return 0;
1003
1004 out_unrec_vers:
1005         printk(KERN_INFO "NFS: unrecognized NFS version number\n");
1006         return 0;
1007
1008 out_unrec_xprt:
1009         printk(KERN_INFO "NFS: unrecognized transport protocol\n");
1010         return 0;
1011
1012 out_unrec_sec:
1013         printk(KERN_INFO "NFS: unrecognized security flavor\n");
1014         return 0;
1015
1016 out_unknown:
1017         printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
1018         return 0;
1019 }
1020
1021 /*
1022  * Use the remote server's MOUNT service to request the NFS file handle
1023  * corresponding to the provided path.
1024  */
1025 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1026                          struct nfs_fh *root_fh)
1027 {
1028         struct sockaddr_in sin;
1029         int status;
1030
1031         if (args->mount_server.version == 0) {
1032                 if (args->flags & NFS_MOUNT_VER3)
1033                         args->mount_server.version = NFS_MNT3_VERSION;
1034                 else
1035                         args->mount_server.version = NFS_MNT_VERSION;
1036         }
1037
1038         /*
1039          * Construct the mount server's address.
1040          */
1041         if (args->mount_server.address.sin_addr.s_addr != INADDR_ANY)
1042                 sin = args->mount_server.address;
1043         else
1044                 sin = args->nfs_server.address;
1045         /*
1046          * autobind will be used if mount_server.port == 0
1047          */
1048         nfs_set_port((struct sockaddr *)&sin, args->mount_server.port);
1049
1050         /*
1051          * Now ask the mount server to map our export path
1052          * to a file handle.
1053          */
1054         status = nfs_mount((struct sockaddr *) &sin,
1055                            sizeof(sin),
1056                            args->nfs_server.hostname,
1057                            args->nfs_server.export_path,
1058                            args->mount_server.version,
1059                            args->mount_server.protocol,
1060                            root_fh);
1061         if (status == 0)
1062                 return 0;
1063
1064         dfprintk(MOUNT, "NFS: unable to mount server " NIPQUAD_FMT
1065                         ", error %d\n", NIPQUAD(sin.sin_addr.s_addr), status);
1066         return status;
1067 }
1068
1069 /*
1070  * Validate the NFS2/NFS3 mount data
1071  * - fills in the mount root filehandle
1072  *
1073  * For option strings, user space handles the following behaviors:
1074  *
1075  * + DNS: mapping server host name to IP address ("addr=" option)
1076  *
1077  * + failure mode: how to behave if a mount request can't be handled
1078  *   immediately ("fg/bg" option)
1079  *
1080  * + retry: how often to retry a mount request ("retry=" option)
1081  *
1082  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1083  *   mountproto=tcp after mountproto=udp, and so on
1084  */
1085 static int nfs_validate_mount_data(void *options,
1086                                    struct nfs_parsed_mount_data *args,
1087                                    struct nfs_fh *mntfh,
1088                                    const char *dev_name)
1089 {
1090         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1091
1092         memset(args, 0, sizeof(*args));
1093
1094         if (data == NULL)
1095                 goto out_no_data;
1096
1097         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1098         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1099         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1100         args->timeo             = 600;
1101         args->retrans           = 2;
1102         args->acregmin          = 3;
1103         args->acregmax          = 60;
1104         args->acdirmin          = 30;
1105         args->acdirmax          = 60;
1106         args->mount_server.protocol = XPRT_TRANSPORT_UDP;
1107         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1108
1109         switch (data->version) {
1110         case 1:
1111                 data->namlen = 0;
1112         case 2:
1113                 data->bsize = 0;
1114         case 3:
1115                 if (data->flags & NFS_MOUNT_VER3)
1116                         goto out_no_v3;
1117                 data->root.size = NFS2_FHSIZE;
1118                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1119         case 4:
1120                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1121                         goto out_no_sec;
1122         case 5:
1123                 memset(data->context, 0, sizeof(data->context));
1124         case 6:
1125                 if (data->flags & NFS_MOUNT_VER3)
1126                         mntfh->size = data->root.size;
1127                 else
1128                         mntfh->size = NFS2_FHSIZE;
1129
1130                 if (mntfh->size > sizeof(mntfh->data))
1131                         goto out_invalid_fh;
1132
1133                 memcpy(mntfh->data, data->root.data, mntfh->size);
1134                 if (mntfh->size < sizeof(mntfh->data))
1135                         memset(mntfh->data + mntfh->size, 0,
1136                                sizeof(mntfh->data) - mntfh->size);
1137
1138                 if (!nfs_verify_server_address((struct sockaddr *) &data->addr))
1139                         goto out_no_address;
1140
1141                 /*
1142                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1143                  * can deal with.
1144                  */
1145                 args->flags             = data->flags;
1146                 args->rsize             = data->rsize;
1147                 args->wsize             = data->wsize;
1148                 args->flags             = data->flags;
1149                 args->timeo             = data->timeo;
1150                 args->retrans           = data->retrans;
1151                 args->acregmin          = data->acregmin;
1152                 args->acregmax          = data->acregmax;
1153                 args->acdirmin          = data->acdirmin;
1154                 args->acdirmax          = data->acdirmax;
1155                 args->nfs_server.address = data->addr;
1156                 if (!(data->flags & NFS_MOUNT_TCP))
1157                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1158                 /* N.B. caller will free nfs_server.hostname in all cases */
1159                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1160                 args->namlen            = data->namlen;
1161                 args->bsize             = data->bsize;
1162                 args->auth_flavors[0]   = data->pseudoflavor;
1163                 break;
1164         default: {
1165                 unsigned int len;
1166                 char *c;
1167                 int status;
1168
1169                 if (nfs_parse_mount_options((char *)options, args) == 0)
1170                         return -EINVAL;
1171
1172                 if (!nfs_verify_server_address((struct sockaddr *)
1173                                                 &args->nfs_server.address))
1174                         goto out_no_address;
1175
1176                 c = strchr(dev_name, ':');
1177                 if (c == NULL)
1178                         return -EINVAL;
1179                 len = c - dev_name;
1180                 /* N.B. caller will free nfs_server.hostname in all cases */
1181                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1182
1183                 c++;
1184                 if (strlen(c) > NFS_MAXPATHLEN)
1185                         return -ENAMETOOLONG;
1186                 args->nfs_server.export_path = c;
1187
1188                 status = nfs_try_mount(args, mntfh);
1189                 if (status)
1190                         return status;
1191
1192                 break;
1193                 }
1194         }
1195
1196         if (!(args->flags & NFS_MOUNT_SECFLAVOUR))
1197                 args->auth_flavors[0] = RPC_AUTH_UNIX;
1198
1199 #ifndef CONFIG_NFS_V3
1200         if (args->flags & NFS_MOUNT_VER3)
1201                 goto out_v3_not_compiled;
1202 #endif /* !CONFIG_NFS_V3 */
1203
1204         return 0;
1205
1206 out_no_data:
1207         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1208         return -EINVAL;
1209
1210 out_no_v3:
1211         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1212                  data->version);
1213         return -EINVAL;
1214
1215 out_no_sec:
1216         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1217         return -EINVAL;
1218
1219 #ifndef CONFIG_NFS_V3
1220 out_v3_not_compiled:
1221         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1222         return -EPROTONOSUPPORT;
1223 #endif /* !CONFIG_NFS_V3 */
1224
1225 out_no_address:
1226         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1227         return -EINVAL;
1228
1229 out_invalid_fh:
1230         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1231         return -EINVAL;
1232 }
1233
1234 /*
1235  * Initialise the common bits of the superblock
1236  */
1237 static inline void nfs_initialise_sb(struct super_block *sb)
1238 {
1239         struct nfs_server *server = NFS_SB(sb);
1240
1241         sb->s_magic = NFS_SUPER_MAGIC;
1242
1243         /* We probably want something more informative here */
1244         snprintf(sb->s_id, sizeof(sb->s_id),
1245                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1246
1247         if (sb->s_blocksize == 0)
1248                 sb->s_blocksize = nfs_block_bits(server->wsize,
1249                                                  &sb->s_blocksize_bits);
1250
1251         if (server->flags & NFS_MOUNT_NOAC)
1252                 sb->s_flags |= MS_SYNCHRONOUS;
1253
1254         nfs_super_set_maxbytes(sb, server->maxfilesize);
1255 }
1256
1257 /*
1258  * Finish setting up an NFS2/3 superblock
1259  */
1260 static void nfs_fill_super(struct super_block *sb,
1261                            struct nfs_parsed_mount_data *data)
1262 {
1263         struct nfs_server *server = NFS_SB(sb);
1264
1265         sb->s_blocksize_bits = 0;
1266         sb->s_blocksize = 0;
1267         if (data->bsize)
1268                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1269
1270         if (server->flags & NFS_MOUNT_VER3) {
1271                 /* The VFS shouldn't apply the umask to mode bits. We will do
1272                  * so ourselves when necessary.
1273                  */
1274                 sb->s_flags |= MS_POSIXACL;
1275                 sb->s_time_gran = 1;
1276         }
1277
1278         sb->s_op = &nfs_sops;
1279         nfs_initialise_sb(sb);
1280 }
1281
1282 /*
1283  * Finish setting up a cloned NFS2/3 superblock
1284  */
1285 static void nfs_clone_super(struct super_block *sb,
1286                             const struct super_block *old_sb)
1287 {
1288         struct nfs_server *server = NFS_SB(sb);
1289
1290         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1291         sb->s_blocksize = old_sb->s_blocksize;
1292         sb->s_maxbytes = old_sb->s_maxbytes;
1293
1294         if (server->flags & NFS_MOUNT_VER3) {
1295                 /* The VFS shouldn't apply the umask to mode bits. We will do
1296                  * so ourselves when necessary.
1297                  */
1298                 sb->s_flags |= MS_POSIXACL;
1299                 sb->s_time_gran = 1;
1300         }
1301
1302         sb->s_op = old_sb->s_op;
1303         nfs_initialise_sb(sb);
1304 }
1305
1306 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
1307
1308 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1309 {
1310         const struct nfs_server *a = s->s_fs_info;
1311         const struct rpc_clnt *clnt_a = a->client;
1312         const struct rpc_clnt *clnt_b = b->client;
1313
1314         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1315                 goto Ebusy;
1316         if (a->nfs_client != b->nfs_client)
1317                 goto Ebusy;
1318         if (a->flags != b->flags)
1319                 goto Ebusy;
1320         if (a->wsize != b->wsize)
1321                 goto Ebusy;
1322         if (a->rsize != b->rsize)
1323                 goto Ebusy;
1324         if (a->acregmin != b->acregmin)
1325                 goto Ebusy;
1326         if (a->acregmax != b->acregmax)
1327                 goto Ebusy;
1328         if (a->acdirmin != b->acdirmin)
1329                 goto Ebusy;
1330         if (a->acdirmax != b->acdirmax)
1331                 goto Ebusy;
1332         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1333                 goto Ebusy;
1334         return 1;
1335 Ebusy:
1336         return 0;
1337 }
1338
1339 struct nfs_sb_mountdata {
1340         struct nfs_server *server;
1341         int mntflags;
1342 };
1343
1344 static int nfs_set_super(struct super_block *s, void *data)
1345 {
1346         struct nfs_sb_mountdata *sb_mntdata = data;
1347         struct nfs_server *server = sb_mntdata->server;
1348         int ret;
1349
1350         s->s_flags = sb_mntdata->mntflags;
1351         s->s_fs_info = server;
1352         ret = set_anon_super(s, server);
1353         if (ret == 0)
1354                 server->s_dev = s->s_dev;
1355         return ret;
1356 }
1357
1358 static int nfs_compare_super_address(struct nfs_server *server1,
1359                                      struct nfs_server *server2)
1360 {
1361         struct sockaddr *sap1, *sap2;
1362
1363         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1364         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1365
1366         if (sap1->sa_family != sap2->sa_family)
1367                 return 0;
1368
1369         switch (sap1->sa_family) {
1370         case AF_INET: {
1371                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1372                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1373                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1374                         return 0;
1375                 if (sin1->sin_port != sin2->sin_port)
1376                         return 0;
1377                 break;
1378         }
1379         case AF_INET6: {
1380                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1381                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1382                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1383                         return 0;
1384                 if (sin1->sin6_port != sin2->sin6_port)
1385                         return 0;
1386                 break;
1387         }
1388         default:
1389                 return 0;
1390         }
1391
1392         return 1;
1393 }
1394
1395 static int nfs_compare_super(struct super_block *sb, void *data)
1396 {
1397         struct nfs_sb_mountdata *sb_mntdata = data;
1398         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1399         int mntflags = sb_mntdata->mntflags;
1400
1401         if (!nfs_compare_super_address(old, server))
1402                 return 0;
1403         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1404         if (old->flags & NFS_MOUNT_UNSHARED)
1405                 return 0;
1406         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1407                 return 0;
1408         return nfs_compare_mount_options(sb, server, mntflags);
1409 }
1410
1411 static int nfs_get_sb(struct file_system_type *fs_type,
1412         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1413 {
1414         struct nfs_server *server = NULL;
1415         struct super_block *s;
1416         struct nfs_fh mntfh;
1417         struct nfs_parsed_mount_data data;
1418         struct dentry *mntroot;
1419         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1420         struct nfs_sb_mountdata sb_mntdata = {
1421                 .mntflags = flags,
1422         };
1423         int error;
1424
1425         /* Validate the mount data */
1426         error = nfs_validate_mount_data(raw_data, &data, &mntfh, dev_name);
1427         if (error < 0)
1428                 goto out;
1429
1430         /* Get a volume representation */
1431         server = nfs_create_server(&data, &mntfh);
1432         if (IS_ERR(server)) {
1433                 error = PTR_ERR(server);
1434                 goto out;
1435         }
1436         sb_mntdata.server = server;
1437
1438         if (server->flags & NFS_MOUNT_UNSHARED)
1439                 compare_super = NULL;
1440
1441         /* Get a superblock - note that we may end up sharing one that already exists */
1442         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1443         if (IS_ERR(s)) {
1444                 error = PTR_ERR(s);
1445                 goto out_err_nosb;
1446         }
1447
1448         if (s->s_fs_info != server) {
1449                 nfs_free_server(server);
1450                 server = NULL;
1451         }
1452
1453         if (!s->s_root) {
1454                 /* initial superblock/root creation */
1455                 nfs_fill_super(s, &data);
1456         }
1457
1458         mntroot = nfs_get_root(s, &mntfh);
1459         if (IS_ERR(mntroot)) {
1460                 error = PTR_ERR(mntroot);
1461                 goto error_splat_super;
1462         }
1463
1464         s->s_flags |= MS_ACTIVE;
1465         mnt->mnt_sb = s;
1466         mnt->mnt_root = mntroot;
1467         error = 0;
1468
1469 out:
1470         kfree(data.nfs_server.hostname);
1471         return error;
1472
1473 out_err_nosb:
1474         nfs_free_server(server);
1475         goto out;
1476
1477 error_splat_super:
1478         up_write(&s->s_umount);
1479         deactivate_super(s);
1480         goto out;
1481 }
1482
1483 /*
1484  * Destroy an NFS2/3 superblock
1485  */
1486 static void nfs_kill_super(struct super_block *s)
1487 {
1488         struct nfs_server *server = NFS_SB(s);
1489
1490         kill_anon_super(s);
1491         nfs_free_server(server);
1492 }
1493
1494 /*
1495  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
1496  */
1497 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
1498                            const char *dev_name, void *raw_data,
1499                            struct vfsmount *mnt)
1500 {
1501         struct nfs_clone_mount *data = raw_data;
1502         struct super_block *s;
1503         struct nfs_server *server;
1504         struct dentry *mntroot;
1505         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1506         struct nfs_sb_mountdata sb_mntdata = {
1507                 .mntflags = flags,
1508         };
1509         int error;
1510
1511         dprintk("--> nfs_xdev_get_sb()\n");
1512
1513         /* create a new volume representation */
1514         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1515         if (IS_ERR(server)) {
1516                 error = PTR_ERR(server);
1517                 goto out_err_noserver;
1518         }
1519         sb_mntdata.server = server;
1520
1521         if (server->flags & NFS_MOUNT_UNSHARED)
1522                 compare_super = NULL;
1523
1524         /* Get a superblock - note that we may end up sharing one that already exists */
1525         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1526         if (IS_ERR(s)) {
1527                 error = PTR_ERR(s);
1528                 goto out_err_nosb;
1529         }
1530
1531         if (s->s_fs_info != server) {
1532                 nfs_free_server(server);
1533                 server = NULL;
1534         }
1535
1536         if (!s->s_root) {
1537                 /* initial superblock/root creation */
1538                 nfs_clone_super(s, data->sb);
1539         }
1540
1541         mntroot = nfs_get_root(s, data->fh);
1542         if (IS_ERR(mntroot)) {
1543                 error = PTR_ERR(mntroot);
1544                 goto error_splat_super;
1545         }
1546         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1547                 dput(mntroot);
1548                 error = -ESTALE;
1549                 goto error_splat_super;
1550         }
1551
1552         s->s_flags |= MS_ACTIVE;
1553         mnt->mnt_sb = s;
1554         mnt->mnt_root = mntroot;
1555
1556         dprintk("<-- nfs_xdev_get_sb() = 0\n");
1557         return 0;
1558
1559 out_err_nosb:
1560         nfs_free_server(server);
1561 out_err_noserver:
1562         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
1563         return error;
1564
1565 error_splat_super:
1566         up_write(&s->s_umount);
1567         deactivate_super(s);
1568         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
1569         return error;
1570 }
1571
1572 #ifdef CONFIG_NFS_V4
1573
1574 /*
1575  * Finish setting up a cloned NFS4 superblock
1576  */
1577 static void nfs4_clone_super(struct super_block *sb,
1578                             const struct super_block *old_sb)
1579 {
1580         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1581         sb->s_blocksize = old_sb->s_blocksize;
1582         sb->s_maxbytes = old_sb->s_maxbytes;
1583         sb->s_time_gran = 1;
1584         sb->s_op = old_sb->s_op;
1585         nfs_initialise_sb(sb);
1586 }
1587
1588 /*
1589  * Set up an NFS4 superblock
1590  */
1591 static void nfs4_fill_super(struct super_block *sb)
1592 {
1593         sb->s_time_gran = 1;
1594         sb->s_op = &nfs4_sops;
1595         nfs_initialise_sb(sb);
1596 }
1597
1598 /*
1599  * If the user didn't specify a port, set the port number to
1600  * the NFS version 4 default port.
1601  */
1602 static void nfs4_default_port(struct sockaddr *sap)
1603 {
1604         switch (sap->sa_family) {
1605         case AF_INET: {
1606                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
1607                 if (ap->sin_port == 0)
1608                         ap->sin_port = htons(NFS_PORT);
1609                 break;
1610         }
1611         case AF_INET6: {
1612                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
1613                 if (ap->sin6_port == 0)
1614                         ap->sin6_port = htons(NFS_PORT);
1615                 break;
1616         }
1617         }
1618 }
1619
1620 /*
1621  * Validate NFSv4 mount options
1622  */
1623 static int nfs4_validate_mount_data(void *options,
1624                                     struct nfs_parsed_mount_data *args,
1625                                     const char *dev_name)
1626 {
1627         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
1628         char *c;
1629
1630         memset(args, 0, sizeof(*args));
1631
1632         if (data == NULL)
1633                 goto out_no_data;
1634
1635         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1636         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1637         args->timeo             = 600;
1638         args->retrans           = 2;
1639         args->acregmin          = 3;
1640         args->acregmax          = 60;
1641         args->acdirmin          = 30;
1642         args->acdirmax          = 60;
1643         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1644
1645         switch (data->version) {
1646         case 1:
1647                 if (data->host_addrlen != sizeof(args->nfs_server.address))
1648                         goto out_no_address;
1649                 if (copy_from_user(&args->nfs_server.address,
1650                                    data->host_addr,
1651                                    sizeof(args->nfs_server.address)))
1652                         return -EFAULT;
1653                 if (!nfs_verify_server_address((struct sockaddr *)
1654                                                 &args->nfs_server.address))
1655                         goto out_no_address;
1656
1657                 nfs4_default_port((struct sockaddr *)
1658                                   &args->nfs_server.address);
1659
1660                 switch (data->auth_flavourlen) {
1661                 case 0:
1662                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1663                         break;
1664                 case 1:
1665                         if (copy_from_user(&args->auth_flavors[0],
1666                                            data->auth_flavours,
1667                                            sizeof(args->auth_flavors[0])))
1668                                 return -EFAULT;
1669                         break;
1670                 default:
1671                         goto out_inval_auth;
1672                 }
1673
1674                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1675                 if (IS_ERR(c))
1676                         return PTR_ERR(c);
1677                 args->nfs_server.hostname = c;
1678
1679                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1680                 if (IS_ERR(c))
1681                         return PTR_ERR(c);
1682                 args->nfs_server.export_path = c;
1683                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1684
1685                 c = strndup_user(data->client_addr.data, 16);
1686                 if (IS_ERR(c))
1687                         return PTR_ERR(c);
1688                 args->client_address = c;
1689
1690                 /*
1691                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
1692                  * can deal with.
1693                  */
1694
1695                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
1696                 args->rsize     = data->rsize;
1697                 args->wsize     = data->wsize;
1698                 args->timeo     = data->timeo;
1699                 args->retrans   = data->retrans;
1700                 args->acregmin  = data->acregmin;
1701                 args->acregmax  = data->acregmax;
1702                 args->acdirmin  = data->acdirmin;
1703                 args->acdirmax  = data->acdirmax;
1704                 args->nfs_server.protocol = data->proto;
1705
1706                 break;
1707         default: {
1708                 unsigned int len;
1709
1710                 if (nfs_parse_mount_options((char *)options, args) == 0)
1711                         return -EINVAL;
1712
1713                 if (!nfs_verify_server_address((struct sockaddr *)
1714                                                 &args->nfs_server.address))
1715                         return -EINVAL;
1716
1717                 nfs4_default_port((struct sockaddr *)
1718                                   &args->nfs_server.address);
1719
1720                 switch (args->auth_flavor_len) {
1721                 case 0:
1722                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1723                         break;
1724                 case 1:
1725                         break;
1726                 default:
1727                         goto out_inval_auth;
1728                 }
1729
1730                 /*
1731                  * Split "dev_name" into "hostname:mntpath".
1732                  */
1733                 c = strchr(dev_name, ':');
1734                 if (c == NULL)
1735                         return -EINVAL;
1736                 /* while calculating len, pretend ':' is '\0' */
1737                 len = c - dev_name;
1738                 if (len > NFS4_MAXNAMLEN)
1739                         return -ENAMETOOLONG;
1740                 /* N.B. caller will free nfs_server.hostname in all cases */
1741                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1742
1743                 c++;                    /* step over the ':' */
1744                 len = strlen(c);
1745                 if (len > NFS4_MAXPATHLEN)
1746                         return -ENAMETOOLONG;
1747                 args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
1748
1749                 dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
1750
1751                 if (args->client_address == NULL)
1752                         goto out_no_client_address;
1753
1754                 break;
1755                 }
1756         }
1757
1758         return 0;
1759
1760 out_no_data:
1761         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
1762         return -EINVAL;
1763
1764 out_inval_auth:
1765         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
1766                  data->auth_flavourlen);
1767         return -EINVAL;
1768
1769 out_no_address:
1770         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
1771         return -EINVAL;
1772
1773 out_no_client_address:
1774         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
1775         return -EINVAL;
1776 }
1777
1778 /*
1779  * Get the superblock for an NFS4 mountpoint
1780  */
1781 static int nfs4_get_sb(struct file_system_type *fs_type,
1782         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1783 {
1784         struct nfs_parsed_mount_data data;
1785         struct super_block *s;
1786         struct nfs_server *server;
1787         struct nfs_fh mntfh;
1788         struct dentry *mntroot;
1789         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1790         struct nfs_sb_mountdata sb_mntdata = {
1791                 .mntflags = flags,
1792         };
1793         int error;
1794
1795         /* Validate the mount data */
1796         error = nfs4_validate_mount_data(raw_data, &data, dev_name);
1797         if (error < 0)
1798                 goto out;
1799
1800         /* Get a volume representation */
1801         server = nfs4_create_server(&data, &mntfh);
1802         if (IS_ERR(server)) {
1803                 error = PTR_ERR(server);
1804                 goto out;
1805         }
1806         sb_mntdata.server = server;
1807
1808         if (server->flags & NFS4_MOUNT_UNSHARED)
1809                 compare_super = NULL;
1810
1811         /* Get a superblock - note that we may end up sharing one that already exists */
1812         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1813         if (IS_ERR(s)) {
1814                 error = PTR_ERR(s);
1815                 goto out_free;
1816         }
1817
1818         if (s->s_fs_info != server) {
1819                 nfs_free_server(server);
1820                 server = NULL;
1821         }
1822
1823         if (!s->s_root) {
1824                 /* initial superblock/root creation */
1825                 nfs4_fill_super(s);
1826         }
1827
1828         mntroot = nfs4_get_root(s, &mntfh);
1829         if (IS_ERR(mntroot)) {
1830                 error = PTR_ERR(mntroot);
1831                 goto error_splat_super;
1832         }
1833
1834         s->s_flags |= MS_ACTIVE;
1835         mnt->mnt_sb = s;
1836         mnt->mnt_root = mntroot;
1837         error = 0;
1838
1839 out:
1840         kfree(data.client_address);
1841         kfree(data.nfs_server.export_path);
1842         kfree(data.nfs_server.hostname);
1843         return error;
1844
1845 out_free:
1846         nfs_free_server(server);
1847         goto out;
1848
1849 error_splat_super:
1850         up_write(&s->s_umount);
1851         deactivate_super(s);
1852         goto out;
1853 }
1854
1855 static void nfs4_kill_super(struct super_block *sb)
1856 {
1857         struct nfs_server *server = NFS_SB(sb);
1858
1859         nfs_return_all_delegations(sb);
1860         kill_anon_super(sb);
1861
1862         nfs4_renewd_prepare_shutdown(server);
1863         nfs_free_server(server);
1864 }
1865
1866 /*
1867  * Clone an NFS4 server record on xdev traversal (FSID-change)
1868  */
1869 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
1870                             const char *dev_name, void *raw_data,
1871                             struct vfsmount *mnt)
1872 {
1873         struct nfs_clone_mount *data = raw_data;
1874         struct super_block *s;
1875         struct nfs_server *server;
1876         struct dentry *mntroot;
1877         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1878         struct nfs_sb_mountdata sb_mntdata = {
1879                 .mntflags = flags,
1880         };
1881         int error;
1882
1883         dprintk("--> nfs4_xdev_get_sb()\n");
1884
1885         /* create a new volume representation */
1886         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1887         if (IS_ERR(server)) {
1888                 error = PTR_ERR(server);
1889                 goto out_err_noserver;
1890         }
1891         sb_mntdata.server = server;
1892
1893         if (server->flags & NFS4_MOUNT_UNSHARED)
1894                 compare_super = NULL;
1895
1896         /* Get a superblock - note that we may end up sharing one that already exists */
1897         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1898         if (IS_ERR(s)) {
1899                 error = PTR_ERR(s);
1900                 goto out_err_nosb;
1901         }
1902
1903         if (s->s_fs_info != server) {
1904                 nfs_free_server(server);
1905                 server = NULL;
1906         }
1907
1908         if (!s->s_root) {
1909                 /* initial superblock/root creation */
1910                 nfs4_clone_super(s, data->sb);
1911         }
1912
1913         mntroot = nfs4_get_root(s, data->fh);
1914         if (IS_ERR(mntroot)) {
1915                 error = PTR_ERR(mntroot);
1916                 goto error_splat_super;
1917         }
1918         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1919                 dput(mntroot);
1920                 error = -ESTALE;
1921                 goto error_splat_super;
1922         }
1923
1924         s->s_flags |= MS_ACTIVE;
1925         mnt->mnt_sb = s;
1926         mnt->mnt_root = mntroot;
1927
1928         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
1929         return 0;
1930
1931 out_err_nosb:
1932         nfs_free_server(server);
1933 out_err_noserver:
1934         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
1935         return error;
1936
1937 error_splat_super:
1938         up_write(&s->s_umount);
1939         deactivate_super(s);
1940         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
1941         return error;
1942 }
1943
1944 /*
1945  * Create an NFS4 server record on referral traversal
1946  */
1947 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
1948                                 const char *dev_name, void *raw_data,
1949                                 struct vfsmount *mnt)
1950 {
1951         struct nfs_clone_mount *data = raw_data;
1952         struct super_block *s;
1953         struct nfs_server *server;
1954         struct dentry *mntroot;
1955         struct nfs_fh mntfh;
1956         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1957         struct nfs_sb_mountdata sb_mntdata = {
1958                 .mntflags = flags,
1959         };
1960         int error;
1961
1962         dprintk("--> nfs4_referral_get_sb()\n");
1963
1964         /* create a new volume representation */
1965         server = nfs4_create_referral_server(data, &mntfh);
1966         if (IS_ERR(server)) {
1967                 error = PTR_ERR(server);
1968                 goto out_err_noserver;
1969         }
1970         sb_mntdata.server = server;
1971
1972         if (server->flags & NFS4_MOUNT_UNSHARED)
1973                 compare_super = NULL;
1974
1975         /* Get a superblock - note that we may end up sharing one that already exists */
1976         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1977         if (IS_ERR(s)) {
1978                 error = PTR_ERR(s);
1979                 goto out_err_nosb;
1980         }
1981
1982         if (s->s_fs_info != server) {
1983                 nfs_free_server(server);
1984                 server = NULL;
1985         }
1986
1987         if (!s->s_root) {
1988                 /* initial superblock/root creation */
1989                 nfs4_fill_super(s);
1990         }
1991
1992         mntroot = nfs4_get_root(s, &mntfh);
1993         if (IS_ERR(mntroot)) {
1994                 error = PTR_ERR(mntroot);
1995                 goto error_splat_super;
1996         }
1997         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1998                 dput(mntroot);
1999                 error = -ESTALE;
2000                 goto error_splat_super;
2001         }
2002
2003         s->s_flags |= MS_ACTIVE;
2004         mnt->mnt_sb = s;
2005         mnt->mnt_root = mntroot;
2006
2007         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2008         return 0;
2009
2010 out_err_nosb:
2011         nfs_free_server(server);
2012 out_err_noserver:
2013         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2014         return error;
2015
2016 error_splat_super:
2017         up_write(&s->s_umount);
2018         deactivate_super(s);
2019         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2020         return error;
2021 }
2022
2023 #endif /* CONFIG_NFS_V4 */