fs/nfs/super.c

   1 /*
   2  *  linux/fs/nfs/super.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  *  Split from inode.c by David Howells <dhowells@redhat.com>
  15  *
  16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17  *   particular server are held in the same superblock
  18  * - NFS superblocks can have several effective roots to the dentry tree
  19  * - directory type roots are spliced into the tree when a path from one root reaches the root
  20  *   of another (see nfs_lookup())
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/time.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/unistd.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/stats.h>
  35 #include <linux/sunrpc/metrics.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/sunrpc/xprtrdma.h>
  38 #include <linux/nfs_fs.h>
  39 #include <linux/nfs_mount.h>
  40 #include <linux/nfs4_mount.h>
  41 #include <linux/lockd/bind.h>
  42 #include <linux/smp_lock.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/mnt_namespace.h>
  46 #include <linux/namei.h>
  47 #include <linux/nfs_idmap.h>
  48 #include <linux/vfs.h>
  49 #include <linux/inet.h>
  50 #include <linux/in6.h>
  51 #include <net/ipv6.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/nfs_xdr.h>
  54 #include <linux/magic.h>
  55 #include <linux/parser.h>
  56
  57 #include <asm/system.h>
  58 #include <asm/uaccess.h>
  59
  60 #include "nfs4_fs.h"
  61 #include "callback.h"
  62 #include "delegation.h"
  63 #include "iostat.h"
  64 #include "internal.h"
  65 #include "fscache.h"
  66
  67 #define NFSDBG_FACILITY         NFSDBG_VFS
  68
  69 enum {
  70         /* Mount options that take no arguments */
  71         Opt_soft, Opt_hard,
  72         Opt_posix, Opt_noposix,
  73         Opt_cto, Opt_nocto,
  74         Opt_ac, Opt_noac,
  75         Opt_lock, Opt_nolock,
  76         Opt_v2, Opt_v3,
  77         Opt_udp, Opt_tcp, Opt_rdma,
  78         Opt_acl, Opt_noacl,
  79         Opt_rdirplus, Opt_nordirplus,
  80         Opt_sharecache, Opt_nosharecache,
  81         Opt_resvport, Opt_noresvport,
  82         Opt_fscache, Opt_nofscache,
  83
  84         /* Mount options that take integer arguments */
  85         Opt_port,
  86         Opt_rsize, Opt_wsize, Opt_bsize,
  87         Opt_timeo, Opt_retrans,
  88         Opt_acregmin, Opt_acregmax,
  89         Opt_acdirmin, Opt_acdirmax,
  90         Opt_actimeo,
  91         Opt_namelen,
  92         Opt_mountport,
  93         Opt_mountvers,
  94         Opt_nfsvers,
  95         Opt_minorversion,
  96
  97         /* Mount options that take string arguments */
  98         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
  99         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 100         Opt_lookupcache,
 101         Opt_fscache_uniq,
 102
 103         /* Special mount options */
 104         Opt_userspace, Opt_deprecated, Opt_sloppy,
 105
 106         Opt_err
 107 };
 108
 109 static const match_table_t nfs_mount_option_tokens = {
 110         { Opt_userspace, "bg" },
 111         { Opt_userspace, "fg" },
 112         { Opt_userspace, "retry=%s" },
 113
 114         { Opt_sloppy, "sloppy" },
 115
 116         { Opt_soft, "soft" },
 117         { Opt_hard, "hard" },
 118         { Opt_deprecated, "intr" },
 119         { Opt_deprecated, "nointr" },
 120         { Opt_posix, "posix" },
 121         { Opt_noposix, "noposix" },
 122         { Opt_cto, "cto" },
 123         { Opt_nocto, "nocto" },
 124         { Opt_ac, "ac" },
 125         { Opt_noac, "noac" },
 126         { Opt_lock, "lock" },
 127         { Opt_nolock, "nolock" },
 128         { Opt_v2, "v2" },
 129         { Opt_v3, "v3" },
 130         { Opt_udp, "udp" },
 131         { Opt_tcp, "tcp" },
 132         { Opt_rdma, "rdma" },
 133         { Opt_acl, "acl" },
 134         { Opt_noacl, "noacl" },
 135         { Opt_rdirplus, "rdirplus" },
 136         { Opt_nordirplus, "nordirplus" },
 137         { Opt_sharecache, "sharecache" },
 138         { Opt_nosharecache, "nosharecache" },
 139         { Opt_resvport, "resvport" },
 140         { Opt_noresvport, "noresvport" },
 141         { Opt_fscache, "fsc" },
 142         { Opt_fscache_uniq, "fsc=%s" },
 143         { Opt_nofscache, "nofsc" },
 144
 145         { Opt_port, "port=%s" },
 146         { Opt_rsize, "rsize=%s" },
 147         { Opt_wsize, "wsize=%s" },
 148         { Opt_bsize, "bsize=%s" },
 149         { Opt_timeo, "timeo=%s" },
 150         { Opt_retrans, "retrans=%s" },
 151         { Opt_acregmin, "acregmin=%s" },
 152         { Opt_acregmax, "acregmax=%s" },
 153         { Opt_acdirmin, "acdirmin=%s" },
 154         { Opt_acdirmax, "acdirmax=%s" },
 155         { Opt_actimeo, "actimeo=%s" },
 156         { Opt_namelen, "namlen=%s" },
 157         { Opt_mountport, "mountport=%s" },
 158         { Opt_mountvers, "mountvers=%s" },
 159         { Opt_nfsvers, "nfsvers=%s" },
 160         { Opt_nfsvers, "vers=%s" },
 161         { Opt_minorversion, "minorversion=%s" },
 162
 163         { Opt_sec, "sec=%s" },
 164         { Opt_proto, "proto=%s" },
 165         { Opt_mountproto, "mountproto=%s" },
 166         { Opt_addr, "addr=%s" },
 167         { Opt_clientaddr, "clientaddr=%s" },
 168         { Opt_mounthost, "mounthost=%s" },
 169         { Opt_mountaddr, "mountaddr=%s" },
 170
 171         { Opt_lookupcache, "lookupcache=%s" },
 172
 173         { Opt_err, NULL }
 174 };
 175
 176 enum {
 177         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 178
 179         Opt_xprt_err
 180 };
 181
 182 static const match_table_t nfs_xprt_protocol_tokens = {
 183         { Opt_xprt_udp, "udp" },
 184         { Opt_xprt_tcp, "tcp" },
 185         { Opt_xprt_rdma, "rdma" },
 186
 187         { Opt_xprt_err, NULL }
 188 };
 189
 190 enum {
 191         Opt_sec_none, Opt_sec_sys,
 192         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 193         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 194         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 195
 196         Opt_sec_err
 197 };
 198
 199 static const match_table_t nfs_secflavor_tokens = {
 200         { Opt_sec_none, "none" },
 201         { Opt_sec_none, "null" },
 202         { Opt_sec_sys, "sys" },
 203
 204         { Opt_sec_krb5, "krb5" },
 205         { Opt_sec_krb5i, "krb5i" },
 206         { Opt_sec_krb5p, "krb5p" },
 207
 208         { Opt_sec_lkey, "lkey" },
 209         { Opt_sec_lkeyi, "lkeyi" },
 210         { Opt_sec_lkeyp, "lkeyp" },
 211
 212         { Opt_sec_spkm, "spkm3" },
 213         { Opt_sec_spkmi, "spkm3i" },
 214         { Opt_sec_spkmp, "spkm3p" },
 215
 216         { Opt_sec_err, NULL }
 217 };
 218
 219 enum {
 220         Opt_lookupcache_all, Opt_lookupcache_positive,
 221         Opt_lookupcache_none,
 222
 223         Opt_lookupcache_err
 224 };
 225
 226 static match_table_t nfs_lookupcache_tokens = {
 227         { Opt_lookupcache_all, "all" },
 228         { Opt_lookupcache_positive, "pos" },
 229         { Opt_lookupcache_positive, "positive" },
 230         { Opt_lookupcache_none, "none" },
 231
 232         { Opt_lookupcache_err, NULL }
 233 };
 234
 235
 236 static void nfs_umount_begin(struct super_block *);
 237 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 238 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 239 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 240 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 241 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 242                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 243 static void nfs_kill_super(struct super_block *);
 244 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 245
 246 static struct file_system_type nfs_fs_type = {
 247         .owner          = THIS_MODULE,
 248         .name           = "nfs",
 249         .get_sb         = nfs_get_sb,
 250         .kill_sb        = nfs_kill_super,
 251         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 252 };
 253
 254 struct file_system_type nfs_xdev_fs_type = {
 255         .owner          = THIS_MODULE,
 256         .name           = "nfs",
 257         .get_sb         = nfs_xdev_get_sb,
 258         .kill_sb        = nfs_kill_super,
 259         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 260 };
 261
 262 static const struct super_operations nfs_sops = {
 263         .alloc_inode    = nfs_alloc_inode,
 264         .destroy_inode  = nfs_destroy_inode,
 265         .write_inode    = nfs_write_inode,
 266         .statfs         = nfs_statfs,
 267         .clear_inode    = nfs_clear_inode,
 268         .umount_begin   = nfs_umount_begin,
 269         .show_options   = nfs_show_options,
 270         .show_stats     = nfs_show_stats,
 271         .remount_fs     = nfs_remount,
 272 };
 273
 274 #ifdef CONFIG_NFS_V4
 275 static int nfs4_get_sb(struct file_system_type *fs_type,
 276         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 277 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 278         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 279 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 280         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 281 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 282         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 283 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
 284         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 285 static void nfs4_kill_super(struct super_block *sb);
 286
 287 static struct file_system_type nfs4_fs_type = {
 288         .owner          = THIS_MODULE,
 289         .name           = "nfs4",
 290         .get_sb         = nfs4_get_sb,
 291         .kill_sb        = nfs4_kill_super,
 292         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 293 };
 294
 295 static struct file_system_type nfs4_remote_fs_type = {
 296         .owner          = THIS_MODULE,
 297         .name           = "nfs4",
 298         .get_sb         = nfs4_remote_get_sb,
 299         .kill_sb        = nfs4_kill_super,
 300         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 301 };
 302
 303 struct file_system_type nfs4_xdev_fs_type = {
 304         .owner          = THIS_MODULE,
 305         .name           = "nfs4",
 306         .get_sb         = nfs4_xdev_get_sb,
 307         .kill_sb        = nfs4_kill_super,
 308         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 309 };
 310
 311 static struct file_system_type nfs4_remote_referral_fs_type = {
 312         .owner          = THIS_MODULE,
 313         .name           = "nfs4",
 314         .get_sb         = nfs4_remote_referral_get_sb,
 315         .kill_sb        = nfs4_kill_super,
 316         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 317 };
 318
 319 struct file_system_type nfs4_referral_fs_type = {
 320         .owner          = THIS_MODULE,
 321         .name           = "nfs4",
 322         .get_sb         = nfs4_referral_get_sb,
 323         .kill_sb        = nfs4_kill_super,
 324         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 325 };
 326
 327 static const struct super_operations nfs4_sops = {
 328         .alloc_inode    = nfs_alloc_inode,
 329         .destroy_inode  = nfs_destroy_inode,
 330         .write_inode    = nfs_write_inode,
 331         .statfs         = nfs_statfs,
 332         .clear_inode    = nfs4_clear_inode,
 333         .umount_begin   = nfs_umount_begin,
 334         .show_options   = nfs_show_options,
 335         .show_stats     = nfs_show_stats,
 336         .remount_fs     = nfs_remount,
 337 };
 338 #endif
 339
 340 static struct shrinker acl_shrinker = {
 341         .shrink         = nfs_access_cache_shrinker,
 342         .seeks          = DEFAULT_SEEKS,
 343 };
 344
 345 /*
 346  * Register the NFS filesystems
 347  */
 348 int __init register_nfs_fs(void)
 349 {
 350         int ret;
 351
 352         ret = register_filesystem(&nfs_fs_type);
 353         if (ret < 0)
 354                 goto error_0;
 355
 356         ret = nfs_register_sysctl();
 357         if (ret < 0)
 358                 goto error_1;
 359 #ifdef CONFIG_NFS_V4
 360         ret = register_filesystem(&nfs4_fs_type);
 361         if (ret < 0)
 362                 goto error_2;
 363 #endif
 364         register_shrinker(&acl_shrinker);
 365         return 0;
 366
 367 #ifdef CONFIG_NFS_V4
 368 error_2:
 369         nfs_unregister_sysctl();
 370 #endif
 371 error_1:
 372         unregister_filesystem(&nfs_fs_type);
 373 error_0:
 374         return ret;
 375 }
 376
 377 /*
 378  * Unregister the NFS filesystems
 379  */
 380 void __exit unregister_nfs_fs(void)
 381 {
 382         unregister_shrinker(&acl_shrinker);
 383 #ifdef CONFIG_NFS_V4
 384         unregister_filesystem(&nfs4_fs_type);
 385 #endif
 386         nfs_unregister_sysctl();
 387         unregister_filesystem(&nfs_fs_type);
 388 }
 389
 390 void nfs_sb_active(struct super_block *sb)
 391 {
 392         struct nfs_server *server = NFS_SB(sb);
 393
 394         if (atomic_inc_return(&server->active) == 1)
 395                 atomic_inc(&sb->s_active);
 396 }
 397
 398 void nfs_sb_deactive(struct super_block *sb)
 399 {
 400         struct nfs_server *server = NFS_SB(sb);
 401
 402         if (atomic_dec_and_test(&server->active))
 403                 deactivate_super(sb);
 404 }
 405
 406 /*
 407  * Deliver file system statistics to userspace
 408  */
 409 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 410 {
 411         struct nfs_server *server = NFS_SB(dentry->d_sb);
 412         unsigned char blockbits;
 413         unsigned long blockres;
 414         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 415         struct nfs_fattr fattr;
 416         struct nfs_fsstat res = {
 417                         .fattr = &fattr,
 418         };
 419         int error;
 420
 421         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 422         if (error < 0)
 423                 goto out_err;
 424         buf->f_type = NFS_SUPER_MAGIC;
 425
 426         /*
 427          * Current versions of glibc do not correctly handle the
 428          * case where f_frsize != f_bsize.  Eventually we want to
 429          * report the value of wtmult in this field.
 430          */
 431         buf->f_frsize = dentry->d_sb->s_blocksize;
 432
 433         /*
 434          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 435          * are reported in units of f_frsize.  Linux hasn't had
 436          * an f_frsize field in its statfs struct until recently,
 437          * thus historically Linux's sys_statfs reports these
 438          * fields in units of f_bsize.
 439          */
 440         buf->f_bsize = dentry->d_sb->s_blocksize;
 441         blockbits = dentry->d_sb->s_blocksize_bits;
 442         blockres = (1 << blockbits) - 1;
 443         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 444         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 445         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 446
 447         buf->f_files = res.tfiles;
 448         buf->f_ffree = res.afiles;
 449
 450         buf->f_namelen = server->namelen;
 451
 452         return 0;
 453
 454  out_err:
 455         dprintk("%s: statfs error = %d\n", __func__, -error);
 456         return error;
 457 }
 458
 459 /*
 460  * Map the security flavour number to a name
 461  */
 462 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 463 {
 464         static const struct {
 465                 rpc_authflavor_t flavour;
 466                 const char *str;
 467         } sec_flavours[] = {
 468                 { RPC_AUTH_NULL, "null" },
 469                 { RPC_AUTH_UNIX, "sys" },
 470                 { RPC_AUTH_GSS_KRB5, "krb5" },
 471                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 472                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 473                 { RPC_AUTH_GSS_LKEY, "lkey" },
 474                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 475                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 476                 { RPC_AUTH_GSS_SPKM, "spkm" },
 477                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 478                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 479                 { UINT_MAX, "unknown" }
 480         };
 481         int i;
 482
 483         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 484                 if (sec_flavours[i].flavour == flavour)
 485                         break;
 486         }
 487         return sec_flavours[i].str;
 488 }
 489
 490 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 491                                     int showdefaults)
 492 {
 493         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 494
 495         switch (sap->sa_family) {
 496         case AF_INET: {
 497                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 498                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 499                 break;
 500         }
 501         case AF_INET6: {
 502                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 503                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 504                 break;
 505         }
 506         default:
 507                 if (showdefaults)
 508                         seq_printf(m, ",mountaddr=unspecified");
 509         }
 510
 511         if (nfss->mountd_version || showdefaults)
 512                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 513         if (nfss->mountd_port || showdefaults)
 514                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 515
 516         switch (nfss->mountd_protocol) {
 517         case IPPROTO_UDP:
 518                 seq_printf(m, ",mountproto=udp");
 519                 break;
 520         case IPPROTO_TCP:
 521                 seq_printf(m, ",mountproto=tcp");
 522                 break;
 523         default:
 524                 if (showdefaults)
 525                         seq_printf(m, ",mountproto=auto");
 526         }
 527 }
 528
 529 /*
 530  * Describe the mount options in force on this server representation
 531  */
 532 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 533                                    int showdefaults)
 534 {
 535         static const struct proc_nfs_info {
 536                 int flag;
 537                 const char *str;
 538                 const char *nostr;
 539         } nfs_info[] = {
 540                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 541                 { NFS_MOUNT_POSIX, ",posix", "" },
 542                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 543                 { NFS_MOUNT_NOAC, ",noac", "" },
 544                 { NFS_MOUNT_NONLM, ",nolock", "" },
 545                 { NFS_MOUNT_NOACL, ",noacl", "" },
 546                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 547                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 548                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 549                 { 0, NULL, NULL }
 550         };
 551         const struct proc_nfs_info *nfs_infop;
 552         struct nfs_client *clp = nfss->nfs_client;
 553         u32 version = clp->rpc_ops->version;
 554
 555         seq_printf(m, ",vers=%u", version);
 556         seq_printf(m, ",rsize=%u", nfss->rsize);
 557         seq_printf(m, ",wsize=%u", nfss->wsize);
 558         if (nfss->bsize != 0)
 559                 seq_printf(m, ",bsize=%u", nfss->bsize);
 560         seq_printf(m, ",namlen=%u", nfss->namelen);
 561         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 562                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 563         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 564                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 565         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 566                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 567         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 568                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 569         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 570                 if (nfss->flags & nfs_infop->flag)
 571                         seq_puts(m, nfs_infop->str);
 572                 else
 573                         seq_puts(m, nfs_infop->nostr);
 574         }
 575         seq_printf(m, ",proto=%s",
 576                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 577         if (version == 4) {
 578                 if (nfss->port != NFS_PORT)
 579                         seq_printf(m, ",port=%u", nfss->port);
 580         } else
 581                 if (nfss->port)
 582                         seq_printf(m, ",port=%u", nfss->port);
 583
 584         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 585         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 586         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 587
 588         if (version != 4)
 589                 nfs_show_mountd_options(m, nfss, showdefaults);
 590
 591 #ifdef CONFIG_NFS_V4
 592         if (clp->rpc_ops->version == 4)
 593                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 594 #endif
 595         if (nfss->options & NFS_OPTION_FSCACHE)
 596                 seq_printf(m, ",fsc");
 597 }
 598
 599 /*
 600  * Describe the mount options on this VFS mountpoint
 601  */
 602 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 603 {
 604         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 605
 606         nfs_show_mount_options(m, nfss, 0);
 607
 608         seq_printf(m, ",addr=%s",
 609                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 610                                                         RPC_DISPLAY_ADDR));
 611
 612         return 0;
 613 }
 614
 615 /*
 616  * Present statistical information for this VFS mountpoint
 617  */
 618 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 619 {
 620         int i, cpu;
 621         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 622         struct rpc_auth *auth = nfss->client->cl_auth;
 623         struct nfs_iostats totals = { };
 624
 625         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 626
 627         /*
 628          * Display all mount option settings
 629          */
 630         seq_printf(m, "\n\topts:\t");
 631         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 632         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 633         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 634         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 635         nfs_show_mount_options(m, nfss, 1);
 636
 637         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 638
 639         seq_printf(m, "\n\tcaps:\t");
 640         seq_printf(m, "caps=0x%x", nfss->caps);
 641         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 642         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 643         seq_printf(m, ",bsize=%u", nfss->bsize);
 644         seq_printf(m, ",namlen=%u", nfss->namelen);
 645
 646 #ifdef CONFIG_NFS_V4
 647         if (nfss->nfs_client->rpc_ops->version == 4) {
 648                 seq_printf(m, "\n\tnfsv4:\t");
 649                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 650                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 651                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 652         }
 653 #endif
 654
 655         /*
 656          * Display security flavor in effect for this mount
 657          */
 658         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 659         if (auth->au_flavor)
 660                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 661
 662         /*
 663          * Display superblock I/O counters
 664          */
 665         for_each_possible_cpu(cpu) {
 666                 struct nfs_iostats *stats;
 667
 668                 preempt_disable();
 669                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 670
 671                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 672                         totals.events[i] += stats->events[i];
 673                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 674                         totals.bytes[i] += stats->bytes[i];
 675 #ifdef CONFIG_NFS_FSCACHE
 676                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 677                         totals.fscache[i] += stats->fscache[i];
 678 #endif
 679
 680                 preempt_enable();
 681         }
 682
 683         seq_printf(m, "\n\tevents:\t");
 684         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 685                 seq_printf(m, "%lu ", totals.events[i]);
 686         seq_printf(m, "\n\tbytes:\t");
 687         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 688                 seq_printf(m, "%Lu ", totals.bytes[i]);
 689 #ifdef CONFIG_NFS_FSCACHE
 690         if (nfss->options & NFS_OPTION_FSCACHE) {
 691                 seq_printf(m, "\n\tfsc:\t");
 692                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 693                         seq_printf(m, "%Lu ", totals.bytes[i]);
 694         }
 695 #endif
 696         seq_printf(m, "\n");
 697
 698         rpc_print_iostats(m, nfss->client);
 699
 700         return 0;
 701 }
 702
 703 /*
 704  * Begin unmount by attempting to remove all automounted mountpoints we added
 705  * in response to xdev traversals and referrals
 706  */
 707 static void nfs_umount_begin(struct super_block *sb)
 708 {
 709         struct nfs_server *server;
 710         struct rpc_clnt *rpc;
 711
 712         lock_kernel();
 713
 714         server = NFS_SB(sb);
 715         /* -EIO all pending I/O */
 716         rpc = server->client_acl;
 717         if (!IS_ERR(rpc))
 718                 rpc_killall_tasks(rpc);
 719         rpc = server->client;
 720         if (!IS_ERR(rpc))
 721                 rpc_killall_tasks(rpc);
 722
 723         unlock_kernel();
 724 }
 725
 726 /*
 727  * Sanity-check a server address provided by the mount command.
 728  *
 729  * Address family must be initialized, and address must not be
 730  * the ANY address for that family.
 731  */
 732 static int nfs_verify_server_address(struct sockaddr *addr)
 733 {
 734         switch (addr->sa_family) {
 735         case AF_INET: {
 736                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 737                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 738         }
 739         case AF_INET6: {
 740                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 741                 return !ipv6_addr_any(sa);
 742         }
 743         }
 744
 745         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 746         return 0;
 747 }
 748
 749 /*
 750  * Sanity check the NFS transport protocol.
 751  *
 752  */
 753 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 754 {
 755         switch (mnt->nfs_server.protocol) {
 756         case XPRT_TRANSPORT_UDP:
 757         case XPRT_TRANSPORT_TCP:
 758         case XPRT_TRANSPORT_RDMA:
 759                 break;
 760         default:
 761                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 762         }
 763 }
 764
 765 /*
 766  * For text based NFSv2/v3 mounts, the mount protocol transport default
 767  * settings should depend upon the specified NFS transport.
 768  */
 769 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 770 {
 771         nfs_validate_transport_protocol(mnt);
 772
 773         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 774             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 775                         return;
 776         switch (mnt->nfs_server.protocol) {
 777         case XPRT_TRANSPORT_UDP:
 778                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 779                 break;
 780         case XPRT_TRANSPORT_TCP:
 781         case XPRT_TRANSPORT_RDMA:
 782                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 783         }
 784 }
 785
 786 /*
 787  * Parse the value of the 'sec=' option.
 788  */
 789 static int nfs_parse_security_flavors(char *value,
 790                                       struct nfs_parsed_mount_data *mnt)
 791 {
 792         substring_t args[MAX_OPT_ARGS];
 793
 794         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 795
 796         switch (match_token(value, nfs_secflavor_tokens, args)) {
 797         case Opt_sec_none:
 798                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 799                 break;
 800         case Opt_sec_sys:
 801                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 802                 break;
 803         case Opt_sec_krb5:
 804                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 805                 break;
 806         case Opt_sec_krb5i:
 807                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 808                 break;
 809         case Opt_sec_krb5p:
 810                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 811                 break;
 812         case Opt_sec_lkey:
 813                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 814                 break;
 815         case Opt_sec_lkeyi:
 816                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 817                 break;
 818         case Opt_sec_lkeyp:
 819                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 820                 break;
 821         case Opt_sec_spkm:
 822                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 823                 break;
 824         case Opt_sec_spkmi:
 825                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 826                 break;
 827         case Opt_sec_spkmp:
 828                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 829                 break;
 830         default:
 831                 return 0;
 832         }
 833
 834         mnt->auth_flavor_len = 1;
 835         return 1;
 836 }
 837
 838 /*
 839  * Error-check and convert a string of mount options from user space into
 840  * a data structure.  The whole mount string is processed; bad options are
 841  * skipped as they are encountered.  If there were no errors, return 1;
 842  * otherwise return 0 (zero).
 843  */
 844 static int nfs_parse_mount_options(char *raw,
 845                                    struct nfs_parsed_mount_data *mnt)
 846 {
 847         char *p, *string, *secdata;
 848         int rc, sloppy = 0, invalid_option = 0;
 849
 850         if (!raw) {
 851                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 852                 return 1;
 853         }
 854         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 855
 856         secdata = alloc_secdata();
 857         if (!secdata)
 858                 goto out_nomem;
 859
 860         rc = security_sb_copy_data(raw, secdata);
 861         if (rc)
 862                 goto out_security_failure;
 863
 864         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 865         if (rc)
 866                 goto out_security_failure;
 867
 868         free_secdata(secdata);
 869
 870         while ((p = strsep(&raw, ",")) != NULL) {
 871                 substring_t args[MAX_OPT_ARGS];
 872                 unsigned long option;
 873                 int token;
 874
 875                 if (!*p)
 876                         continue;
 877
 878                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 879
 880                 token = match_token(p, nfs_mount_option_tokens, args);
 881                 switch (token) {
 882
 883                 /*
 884                  * boolean options:  foo/nofoo
 885                  */
 886                 case Opt_soft:
 887                         mnt->flags |= NFS_MOUNT_SOFT;
 888                         break;
 889                 case Opt_hard:
 890                         mnt->flags &= ~NFS_MOUNT_SOFT;
 891                         break;
 892                 case Opt_posix:
 893                         mnt->flags |= NFS_MOUNT_POSIX;
 894                         break;
 895                 case Opt_noposix:
 896                         mnt->flags &= ~NFS_MOUNT_POSIX;
 897                         break;
 898                 case Opt_cto:
 899                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 900                         break;
 901                 case Opt_nocto:
 902                         mnt->flags |= NFS_MOUNT_NOCTO;
 903                         break;
 904                 case Opt_ac:
 905                         mnt->flags &= ~NFS_MOUNT_NOAC;
 906                         break;
 907                 case Opt_noac:
 908                         mnt->flags |= NFS_MOUNT_NOAC;
 909                         break;
 910                 case Opt_lock:
 911                         mnt->flags &= ~NFS_MOUNT_NONLM;
 912                         break;
 913                 case Opt_nolock:
 914                         mnt->flags |= NFS_MOUNT_NONLM;
 915                         break;
 916                 case Opt_v2:
 917                         mnt->flags &= ~NFS_MOUNT_VER3;
 918                         break;
 919                 case Opt_v3:
 920                         mnt->flags |= NFS_MOUNT_VER3;
 921                         break;
 922                 case Opt_udp:
 923                         mnt->flags &= ~NFS_MOUNT_TCP;
 924                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 925                         break;
 926                 case Opt_tcp:
 927                         mnt->flags |= NFS_MOUNT_TCP;
 928                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 929                         break;
 930                 case Opt_rdma:
 931                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 932                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 933                         xprt_load_transport(p);
 934                         break;
 935                 case Opt_acl:
 936                         mnt->flags &= ~NFS_MOUNT_NOACL;
 937                         break;
 938                 case Opt_noacl:
 939                         mnt->flags |= NFS_MOUNT_NOACL;
 940                         break;
 941                 case Opt_rdirplus:
 942                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 943                         break;
 944                 case Opt_nordirplus:
 945                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 946                         break;
 947                 case Opt_sharecache:
 948                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 949                         break;
 950                 case Opt_nosharecache:
 951                         mnt->flags |= NFS_MOUNT_UNSHARED;
 952                         break;
 953                 case Opt_resvport:
 954                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
 955                         break;
 956                 case Opt_noresvport:
 957                         mnt->flags |= NFS_MOUNT_NORESVPORT;
 958                         break;
 959                 case Opt_fscache:
 960                         mnt->options |= NFS_OPTION_FSCACHE;
 961                         kfree(mnt->fscache_uniq);
 962                         mnt->fscache_uniq = NULL;
 963                         break;
 964                 case Opt_nofscache:
 965                         mnt->options &= ~NFS_OPTION_FSCACHE;
 966                         kfree(mnt->fscache_uniq);
 967                         mnt->fscache_uniq = NULL;
 968                         break;
 969                 case Opt_fscache_uniq:
 970                         string = match_strdup(args);
 971                         if (!string)
 972                                 goto out_nomem;
 973                         kfree(mnt->fscache_uniq);
 974                         mnt->fscache_uniq = string;
 975                         mnt->options |= NFS_OPTION_FSCACHE;
 976                         break;
 977
 978                 /*
 979                  * options that take numeric values
 980                  */
 981                 case Opt_port:
 982                         string = match_strdup(args);
 983                         if (string == NULL)
 984                                 goto out_nomem;
 985                         rc = strict_strtoul(string, 10, &option);
 986                         kfree(string);
 987                         if (rc != 0 || option > USHORT_MAX)
 988                                 goto out_invalid_value;
 989                         mnt->nfs_server.port = option;
 990                         break;
 991                 case Opt_rsize:
 992                         string = match_strdup(args);
 993                         if (string == NULL)
 994                                 goto out_nomem;
 995                         rc = strict_strtoul(string, 10, &option);
 996                         kfree(string);
 997                         if (rc != 0)
 998                                 goto out_invalid_value;
 999                         mnt->rsize = option;
1000                         break;
1001                 case Opt_wsize:
1002                         string = match_strdup(args);
1003                         if (string == NULL)
1004                                 goto out_nomem;
1005                         rc = strict_strtoul(string, 10, &option);
1006                         kfree(string);
1007                         if (rc != 0)
1008                                 goto out_invalid_value;
1009                         mnt->wsize = option;
1010                         break;
1011                 case Opt_bsize:
1012                         string = match_strdup(args);
1013                         if (string == NULL)
1014                                 goto out_nomem;
1015                         rc = strict_strtoul(string, 10, &option);
1016                         kfree(string);
1017                         if (rc != 0)
1018                                 goto out_invalid_value;
1019                         mnt->bsize = option;
1020                         break;
1021                 case Opt_timeo:
1022                         string = match_strdup(args);
1023                         if (string == NULL)
1024                                 goto out_nomem;
1025                         rc = strict_strtoul(string, 10, &option);
1026                         kfree(string);
1027                         if (rc != 0 || option == 0)
1028                                 goto out_invalid_value;
1029                         mnt->timeo = option;
1030                         break;
1031                 case Opt_retrans:
1032                         string = match_strdup(args);
1033                         if (string == NULL)
1034                                 goto out_nomem;
1035                         rc = strict_strtoul(string, 10, &option);
1036                         kfree(string);
1037                         if (rc != 0 || option == 0)
1038                                 goto out_invalid_value;
1039                         mnt->retrans = option;
1040                         break;
1041                 case Opt_acregmin:
1042                         string = match_strdup(args);
1043                         if (string == NULL)
1044                                 goto out_nomem;
1045                         rc = strict_strtoul(string, 10, &option);
1046                         kfree(string);
1047                         if (rc != 0)
1048                                 goto out_invalid_value;
1049                         mnt->acregmin = option;
1050                         break;
1051                 case Opt_acregmax:
1052                         string = match_strdup(args);
1053                         if (string == NULL)
1054                                 goto out_nomem;
1055                         rc = strict_strtoul(string, 10, &option);
1056                         kfree(string);
1057                         if (rc != 0)
1058                                 goto out_invalid_value;
1059                         mnt->acregmax = option;
1060                         break;
1061                 case Opt_acdirmin:
1062                         string = match_strdup(args);
1063                         if (string == NULL)
1064                                 goto out_nomem;
1065                         rc = strict_strtoul(string, 10, &option);
1066                         kfree(string);
1067                         if (rc != 0)
1068                                 goto out_invalid_value;
1069                         mnt->acdirmin = option;
1070                         break;
1071                 case Opt_acdirmax:
1072                         string = match_strdup(args);
1073                         if (string == NULL)
1074                                 goto out_nomem;
1075                         rc = strict_strtoul(string, 10, &option);
1076                         kfree(string);
1077                         if (rc != 0)
1078                                 goto out_invalid_value;
1079                         mnt->acdirmax = option;
1080                         break;
1081                 case Opt_actimeo:
1082                         string = match_strdup(args);
1083                         if (string == NULL)
1084                                 goto out_nomem;
1085                         rc = strict_strtoul(string, 10, &option);
1086                         kfree(string);
1087                         if (rc != 0)
1088                                 goto out_invalid_value;
1089                         mnt->acregmin = mnt->acregmax =
1090                         mnt->acdirmin = mnt->acdirmax = option;
1091                         break;
1092                 case Opt_namelen:
1093                         string = match_strdup(args);
1094                         if (string == NULL)
1095                                 goto out_nomem;
1096                         rc = strict_strtoul(string, 10, &option);
1097                         kfree(string);
1098                         if (rc != 0)
1099                                 goto out_invalid_value;
1100                         mnt->namlen = option;
1101                         break;
1102                 case Opt_mountport:
1103                         string = match_strdup(args);
1104                         if (string == NULL)
1105                                 goto out_nomem;
1106                         rc = strict_strtoul(string, 10, &option);
1107                         kfree(string);
1108                         if (rc != 0 || option > USHORT_MAX)
1109                                 goto out_invalid_value;
1110                         mnt->mount_server.port = option;
1111                         break;
1112                 case Opt_mountvers:
1113                         string = match_strdup(args);
1114                         if (string == NULL)
1115                                 goto out_nomem;
1116                         rc = strict_strtoul(string, 10, &option);
1117                         kfree(string);
1118                         if (rc != 0 ||
1119                             option < NFS_MNT_VERSION ||
1120                             option > NFS_MNT3_VERSION)
1121                                 goto out_invalid_value;
1122                         mnt->mount_server.version = option;
1123                         break;
1124                 case Opt_nfsvers:
1125                         string = match_strdup(args);
1126                         if (string == NULL)
1127                                 goto out_nomem;
1128                         rc = strict_strtoul(string, 10, &option);
1129                         kfree(string);
1130                         if (rc != 0)
1131                                 goto out_invalid_value;
1132                         switch (option) {
1133                         case NFS2_VERSION:
1134                                 mnt->flags &= ~NFS_MOUNT_VER3;
1135                                 break;
1136                         case NFS3_VERSION:
1137                                 mnt->flags |= NFS_MOUNT_VER3;
1138                                 break;
1139                         default:
1140                                 goto out_invalid_value;
1141                         }
1142                         break;
1143                 case Opt_minorversion:
1144                         string = match_strdup(args);
1145                         if (string == NULL)
1146                                 goto out_nomem;
1147                         rc = strict_strtoul(string, 10, &option);
1148                         kfree(string);
1149                         if (rc != 0)
1150                                 goto out_invalid_value;
1151                         if (option > NFS4_MAX_MINOR_VERSION)
1152                                 goto out_invalid_value;
1153                         mnt->minorversion = option;
1154                         break;
1155
1156                 /*
1157                  * options that take text values
1158                  */
1159                 case Opt_sec:
1160                         string = match_strdup(args);
1161                         if (string == NULL)
1162                                 goto out_nomem;
1163                         rc = nfs_parse_security_flavors(string, mnt);
1164                         kfree(string);
1165                         if (!rc) {
1166                                 dfprintk(MOUNT, "NFS:   unrecognized "
1167                                                 "security flavor\n");
1168                                 return 0;
1169                         }
1170                         break;
1171                 case Opt_proto:
1172                         string = match_strdup(args);
1173                         if (string == NULL)
1174                                 goto out_nomem;
1175                         token = match_token(string,
1176                                             nfs_xprt_protocol_tokens, args);
1177
1178                         switch (token) {
1179                         case Opt_xprt_udp:
1180                                 mnt->flags &= ~NFS_MOUNT_TCP;
1181                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1182                                 kfree(string);
1183                                 break;
1184                         case Opt_xprt_tcp:
1185                                 mnt->flags |= NFS_MOUNT_TCP;
1186                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1187                                 kfree(string);
1188                                 break;
1189                         case Opt_xprt_rdma:
1190                                 /* vector side protocols to TCP */
1191                                 mnt->flags |= NFS_MOUNT_TCP;
1192                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1193                                 xprt_load_transport(string);
1194                                 kfree(string);
1195                                 break;
1196                         default:
1197                                 dfprintk(MOUNT, "NFS:   unrecognized "
1198                                                 "transport protocol\n");
1199                                 return 0;
1200                         }
1201                         break;
1202                 case Opt_mountproto:
1203                         string = match_strdup(args);
1204                         if (string == NULL)
1205                                 goto out_nomem;
1206                         token = match_token(string,
1207                                             nfs_xprt_protocol_tokens, args);
1208                         kfree(string);
1209
1210                         switch (token) {
1211                         case Opt_xprt_udp:
1212                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1213                                 break;
1214                         case Opt_xprt_tcp:
1215                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1216                                 break;
1217                         case Opt_xprt_rdma: /* not used for side protocols */
1218                         default:
1219                                 dfprintk(MOUNT, "NFS:   unrecognized "
1220                                                 "transport protocol\n");
1221                                 return 0;
1222                         }
1223                         break;
1224                 case Opt_addr:
1225                         string = match_strdup(args);
1226                         if (string == NULL)
1227                                 goto out_nomem;
1228                         mnt->nfs_server.addrlen =
1229                                 rpc_pton(string, strlen(string),
1230                                         (struct sockaddr *)
1231                                         &mnt->nfs_server.address,
1232                                         sizeof(mnt->nfs_server.address));
1233                         kfree(string);
1234                         if (mnt->nfs_server.addrlen == 0)
1235                                 goto out_invalid_address;
1236                         break;
1237                 case Opt_clientaddr:
1238                         string = match_strdup(args);
1239                         if (string == NULL)
1240                                 goto out_nomem;
1241                         kfree(mnt->client_address);
1242                         mnt->client_address = string;
1243                         break;
1244                 case Opt_mounthost:
1245                         string = match_strdup(args);
1246                         if (string == NULL)
1247                                 goto out_nomem;
1248                         kfree(mnt->mount_server.hostname);
1249                         mnt->mount_server.hostname = string;
1250                         break;
1251                 case Opt_mountaddr:
1252                         string = match_strdup(args);
1253                         if (string == NULL)
1254                                 goto out_nomem;
1255                         mnt->mount_server.addrlen =
1256                                 rpc_pton(string, strlen(string),
1257                                         (struct sockaddr *)
1258                                         &mnt->mount_server.address,
1259                                         sizeof(mnt->mount_server.address));
1260                         kfree(string);
1261                         if (mnt->mount_server.addrlen == 0)
1262                                 goto out_invalid_address;
1263                         break;
1264                 case Opt_lookupcache:
1265                         string = match_strdup(args);
1266                         if (string == NULL)
1267                                 goto out_nomem;
1268                         token = match_token(string,
1269                                         nfs_lookupcache_tokens, args);
1270                         kfree(string);
1271                         switch (token) {
1272                                 case Opt_lookupcache_all:
1273                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1274                                         break;
1275                                 case Opt_lookupcache_positive:
1276                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1277                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1278                                         break;
1279                                 case Opt_lookupcache_none:
1280                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1281                                         break;
1282                                 default:
1283                                         dfprintk(MOUNT, "NFS:   invalid "
1284                                                         "lookupcache argument\n");
1285                                         return 0;
1286                         };
1287                         break;
1288
1289                 /*
1290                  * Special options
1291                  */
1292                 case Opt_sloppy:
1293                         sloppy = 1;
1294                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1295                         break;
1296                 case Opt_userspace:
1297                 case Opt_deprecated:
1298                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1299                                         "'%s'\n", p);
1300                         break;
1301
1302                 default:
1303                         invalid_option = 1;
1304                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1305                                         "'%s'\n", p);
1306                 }
1307         }
1308
1309         if (!sloppy && invalid_option)
1310                 return 0;
1311
1312         return 1;
1313
1314 out_invalid_address:
1315         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1316         return 0;
1317 out_invalid_value:
1318         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1319         return 0;
1320 out_nomem:
1321         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1322         return 0;
1323 out_security_failure:
1324         free_secdata(secdata);
1325         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1326         return 0;
1327 }
1328
1329 /*
1330  * Match the requested auth flavors with the list returned by
1331  * the server.  Returns zero and sets the mount's authentication
1332  * flavor on success; returns -EACCES if server does not support
1333  * the requested flavor.
1334  */
1335 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1336                              struct nfs_mount_request *request)
1337 {
1338         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1339
1340         /*
1341          * We avoid sophisticated negotiating here, as there are
1342          * plenty of cases where we can get it wrong, providing
1343          * either too little or too much security.
1344          *
1345          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1346          * flavor listed first.  However, some servers list
1347          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1348          * preferred default, in args->auth_flavors[0] if user
1349          * didn't specify sec= mount option.
1350          */
1351         for (i = 0; i < args->auth_flavor_len; i++)
1352                 for (j = 0; j < server_authlist_len; j++)
1353                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1354                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1355                                         request->auth_flavs[j]);
1356                                 args->auth_flavors[0] = request->auth_flavs[j];
1357                                 return 0;
1358                         }
1359
1360         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1361         nfs_umount(request);
1362         return -EACCES;
1363 }
1364
1365 /*
1366  * Use the remote server's MOUNT service to request the NFS file handle
1367  * corresponding to the provided path.
1368  */
1369 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1370                          struct nfs_fh *root_fh)
1371 {
1372         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1373         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1374         struct nfs_mount_request request = {
1375                 .sap            = (struct sockaddr *)
1376                                                 &args->mount_server.address,
1377                 .dirpath        = args->nfs_server.export_path,
1378                 .protocol       = args->mount_server.protocol,
1379                 .fh             = root_fh,
1380                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1381                 .auth_flav_len  = &server_authlist_len,
1382                 .auth_flavs     = server_authlist,
1383         };
1384         int status;
1385
1386         if (args->mount_server.version == 0) {
1387                 if (args->flags & NFS_MOUNT_VER3)
1388                         args->mount_server.version = NFS_MNT3_VERSION;
1389                 else
1390                         args->mount_server.version = NFS_MNT_VERSION;
1391         }
1392         request.version = args->mount_server.version;
1393
1394         if (args->mount_server.hostname)
1395                 request.hostname = args->mount_server.hostname;
1396         else
1397                 request.hostname = args->nfs_server.hostname;
1398
1399         /*
1400          * Construct the mount server's address.
1401          */
1402         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1403                 memcpy(request.sap, &args->nfs_server.address,
1404                        args->nfs_server.addrlen);
1405                 args->mount_server.addrlen = args->nfs_server.addrlen;
1406         }
1407         request.salen = args->mount_server.addrlen;
1408
1409         /*
1410          * autobind will be used if mount_server.port == 0
1411          */
1412         rpc_set_port(request.sap, args->mount_server.port);
1413
1414         /*
1415          * Now ask the mount server to map our export path
1416          * to a file handle.
1417          */
1418         status = nfs_mount(&request);
1419         if (status != 0) {
1420                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1421                                 request.hostname, status);
1422                 return status;
1423         }
1424
1425         /*
1426          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1427          */
1428         if (args->mount_server.version != NFS_MNT3_VERSION)
1429                 return 0;
1430         return nfs_walk_authlist(args, &request);
1431 }
1432
1433 static int nfs_parse_simple_hostname(const char *dev_name,
1434                                      char **hostname, size_t maxnamlen,
1435                                      char **export_path, size_t maxpathlen)
1436 {
1437         size_t len;
1438         char *colon, *comma;
1439
1440         colon = strchr(dev_name, ':');
1441         if (colon == NULL)
1442                 goto out_bad_devname;
1443
1444         len = colon - dev_name;
1445         if (len > maxnamlen)
1446                 goto out_hostname;
1447
1448         /* N.B. caller will free nfs_server.hostname in all cases */
1449         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1450         if (!*hostname)
1451                 goto out_nomem;
1452
1453         /* kill possible hostname list: not supported */
1454         comma = strchr(*hostname, ',');
1455         if (comma != NULL) {
1456                 if (comma == *hostname)
1457                         goto out_bad_devname;
1458                 *comma = '\0';
1459         }
1460
1461         colon++;
1462         len = strlen(colon);
1463         if (len > maxpathlen)
1464                 goto out_path;
1465         *export_path = kstrndup(colon, len, GFP_KERNEL);
1466         if (!*export_path)
1467                 goto out_nomem;
1468
1469         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1470         return 0;
1471
1472 out_bad_devname:
1473         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1474         return -EINVAL;
1475
1476 out_nomem:
1477         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1478         return -ENOMEM;
1479
1480 out_hostname:
1481         dfprintk(MOUNT, "NFS: server hostname too long\n");
1482         return -ENAMETOOLONG;
1483
1484 out_path:
1485         dfprintk(MOUNT, "NFS: export pathname too long\n");
1486         return -ENAMETOOLONG;
1487 }
1488
1489 /*
1490  * Hostname has square brackets around it because it contains one or
1491  * more colons.  We look for the first closing square bracket, and a
1492  * colon must follow it.
1493  */
1494 static int nfs_parse_protected_hostname(const char *dev_name,
1495                                         char **hostname, size_t maxnamlen,
1496                                         char **export_path, size_t maxpathlen)
1497 {
1498         size_t len;
1499         char *start, *end;
1500
1501         start = (char *)(dev_name + 1);
1502
1503         end = strchr(start, ']');
1504         if (end == NULL)
1505                 goto out_bad_devname;
1506         if (*(end + 1) != ':')
1507                 goto out_bad_devname;
1508
1509         len = end - start;
1510         if (len > maxnamlen)
1511                 goto out_hostname;
1512
1513         /* N.B. caller will free nfs_server.hostname in all cases */
1514         *hostname = kstrndup(start, len, GFP_KERNEL);
1515         if (*hostname == NULL)
1516                 goto out_nomem;
1517
1518         end += 2;
1519         len = strlen(end);
1520         if (len > maxpathlen)
1521                 goto out_path;
1522         *export_path = kstrndup(end, len, GFP_KERNEL);
1523         if (!*export_path)
1524                 goto out_nomem;
1525
1526         return 0;
1527
1528 out_bad_devname:
1529         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1530         return -EINVAL;
1531
1532 out_nomem:
1533         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1534         return -ENOMEM;
1535
1536 out_hostname:
1537         dfprintk(MOUNT, "NFS: server hostname too long\n");
1538         return -ENAMETOOLONG;
1539
1540 out_path:
1541         dfprintk(MOUNT, "NFS: export pathname too long\n");
1542         return -ENAMETOOLONG;
1543 }
1544
1545 /*
1546  * Split "dev_name" into "hostname:export_path".
1547  *
1548  * The leftmost colon demarks the split between the server's hostname
1549  * and the export path.  If the hostname starts with a left square
1550  * bracket, then it may contain colons.
1551  *
1552  * Note: caller frees hostname and export path, even on error.
1553  */
1554 static int nfs_parse_devname(const char *dev_name,
1555                              char **hostname, size_t maxnamlen,
1556                              char **export_path, size_t maxpathlen)
1557 {
1558         if (*dev_name == '[')
1559                 return nfs_parse_protected_hostname(dev_name,
1560                                                     hostname, maxnamlen,
1561                                                     export_path, maxpathlen);
1562
1563         return nfs_parse_simple_hostname(dev_name,
1564                                          hostname, maxnamlen,
1565                                          export_path, maxpathlen);
1566 }
1567
1568 /*
1569  * Validate the NFS2/NFS3 mount data
1570  * - fills in the mount root filehandle
1571  *
1572  * For option strings, user space handles the following behaviors:
1573  *
1574  * + DNS: mapping server host name to IP address ("addr=" option)
1575  *
1576  * + failure mode: how to behave if a mount request can't be handled
1577  *   immediately ("fg/bg" option)
1578  *
1579  * + retry: how often to retry a mount request ("retry=" option)
1580  *
1581  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1582  *   mountproto=tcp after mountproto=udp, and so on
1583  */
1584 static int nfs_validate_mount_data(void *options,
1585                                    struct nfs_parsed_mount_data *args,
1586                                    struct nfs_fh *mntfh,
1587                                    const char *dev_name)
1588 {
1589         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1590
1591         if (data == NULL)
1592                 goto out_no_data;
1593
1594         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1595         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1596         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1597         args->acregmin          = NFS_DEF_ACREGMIN;
1598         args->acregmax          = NFS_DEF_ACREGMAX;
1599         args->acdirmin          = NFS_DEF_ACDIRMIN;
1600         args->acdirmax          = NFS_DEF_ACDIRMAX;
1601         args->mount_server.port = 0;    /* autobind unless user sets port */
1602         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1603         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1604         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1605         args->auth_flavor_len   = 1;
1606
1607         switch (data->version) {
1608         case 1:
1609                 data->namlen = 0;
1610         case 2:
1611                 data->bsize = 0;
1612         case 3:
1613                 if (data->flags & NFS_MOUNT_VER3)
1614                         goto out_no_v3;
1615                 data->root.size = NFS2_FHSIZE;
1616                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1617         case 4:
1618                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1619                         goto out_no_sec;
1620         case 5:
1621                 memset(data->context, 0, sizeof(data->context));
1622         case 6:
1623                 if (data->flags & NFS_MOUNT_VER3) {
1624                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1625                                 goto out_invalid_fh;
1626                         mntfh->size = data->root.size;
1627                 } else
1628                         mntfh->size = NFS2_FHSIZE;
1629
1630
1631                 memcpy(mntfh->data, data->root.data, mntfh->size);
1632                 if (mntfh->size < sizeof(mntfh->data))
1633                         memset(mntfh->data + mntfh->size, 0,
1634                                sizeof(mntfh->data) - mntfh->size);
1635
1636                 /*
1637                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1638                  * can deal with.
1639                  */
1640                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1641                 args->rsize             = data->rsize;
1642                 args->wsize             = data->wsize;
1643                 args->timeo             = data->timeo;
1644                 args->retrans           = data->retrans;
1645                 args->acregmin          = data->acregmin;
1646                 args->acregmax          = data->acregmax;
1647                 args->acdirmin          = data->acdirmin;
1648                 args->acdirmax          = data->acdirmax;
1649
1650                 memcpy(&args->nfs_server.address, &data->addr,
1651                        sizeof(data->addr));
1652                 args->nfs_server.addrlen = sizeof(data->addr);
1653                 if (!nfs_verify_server_address((struct sockaddr *)
1654                                                 &args->nfs_server.address))
1655                         goto out_no_address;
1656
1657                 if (!(data->flags & NFS_MOUNT_TCP))
1658                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1659                 /* N.B. caller will free nfs_server.hostname in all cases */
1660                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1661                 args->namlen            = data->namlen;
1662                 args->bsize             = data->bsize;
1663
1664                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1665                         args->auth_flavors[0] = data->pseudoflavor;
1666                 if (!args->nfs_server.hostname)
1667                         goto out_nomem;
1668
1669                 /*
1670                  * The legacy version 6 binary mount data from userspace has a
1671                  * field used only to transport selinux information into the
1672                  * the kernel.  To continue to support that functionality we
1673                  * have a touch of selinux knowledge here in the NFS code. The
1674                  * userspace code converted context=blah to just blah so we are
1675                  * converting back to the full string selinux understands.
1676                  */
1677                 if (data->context[0]){
1678 #ifdef CONFIG_SECURITY_SELINUX
1679                         int rc;
1680                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1681                         if (!opts_str)
1682                                 return -ENOMEM;
1683                         strcpy(opts_str, "context=");
1684                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1685                         strcat(opts_str, &data->context[0]);
1686                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1687                         kfree(opts_str);
1688                         if (rc)
1689                                 return rc;
1690 #else
1691                         return -EINVAL;
1692 #endif
1693                 }
1694
1695                 break;
1696         default: {
1697                 int status;
1698
1699                 if (nfs_parse_mount_options((char *)options, args) == 0)
1700                         return -EINVAL;
1701
1702                 if (!nfs_verify_server_address((struct sockaddr *)
1703                                                 &args->nfs_server.address))
1704                         goto out_no_address;
1705
1706                 rpc_set_port((struct sockaddr *)&args->nfs_server.address,
1707                                 args->nfs_server.port);
1708
1709                 nfs_set_mount_transport_protocol(args);
1710
1711                 status = nfs_parse_devname(dev_name,
1712                                            &args->nfs_server.hostname,
1713                                            PAGE_SIZE,
1714                                            &args->nfs_server.export_path,
1715                                            NFS_MAXPATHLEN);
1716                 if (!status)
1717                         status = nfs_try_mount(args, mntfh);
1718
1719                 kfree(args->nfs_server.export_path);
1720                 args->nfs_server.export_path = NULL;
1721
1722                 if (status)
1723                         return status;
1724
1725                 break;
1726                 }
1727         }
1728
1729 #ifndef CONFIG_NFS_V3
1730         if (args->flags & NFS_MOUNT_VER3)
1731                 goto out_v3_not_compiled;
1732 #endif /* !CONFIG_NFS_V3 */
1733
1734         return 0;
1735
1736 out_no_data:
1737         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1738         return -EINVAL;
1739
1740 out_no_v3:
1741         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1742                  data->version);
1743         return -EINVAL;
1744
1745 out_no_sec:
1746         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1747         return -EINVAL;
1748
1749 #ifndef CONFIG_NFS_V3
1750 out_v3_not_compiled:
1751         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1752         return -EPROTONOSUPPORT;
1753 #endif /* !CONFIG_NFS_V3 */
1754
1755 out_nomem:
1756         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1757         return -ENOMEM;
1758
1759 out_no_address:
1760         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1761         return -EINVAL;
1762
1763 out_invalid_fh:
1764         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1765         return -EINVAL;
1766 }
1767
1768 static int
1769 nfs_compare_remount_data(struct nfs_server *nfss,
1770                          struct nfs_parsed_mount_data *data)
1771 {
1772         if (data->flags != nfss->flags ||
1773             data->rsize != nfss->rsize ||
1774             data->wsize != nfss->wsize ||
1775             data->retrans != nfss->client->cl_timeout->to_retries ||
1776             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1777             data->acregmin != nfss->acregmin / HZ ||
1778             data->acregmax != nfss->acregmax / HZ ||
1779             data->acdirmin != nfss->acdirmin / HZ ||
1780             data->acdirmax != nfss->acdirmax / HZ ||
1781             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1782             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1783             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1784                    data->nfs_server.addrlen) != 0)
1785                 return -EINVAL;
1786
1787         return 0;
1788 }
1789
1790 static int
1791 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1792 {
1793         int error;
1794         struct nfs_server *nfss = sb->s_fs_info;
1795         struct nfs_parsed_mount_data *data;
1796         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1797         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1798         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1799
1800         /*
1801          * Userspace mount programs that send binary options generally send
1802          * them populated with default values. We have no way to know which
1803          * ones were explicitly specified. Fall back to legacy behavior and
1804          * just return success.
1805          */
1806         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1807             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1808                                            options->version <= 6))))
1809                 return 0;
1810
1811         data = kzalloc(sizeof(*data), GFP_KERNEL);
1812         if (data == NULL)
1813                 return -ENOMEM;
1814
1815         lock_kernel();
1816         /* fill out struct with values from existing mount */
1817         data->flags = nfss->flags;
1818         data->rsize = nfss->rsize;
1819         data->wsize = nfss->wsize;
1820         data->retrans = nfss->client->cl_timeout->to_retries;
1821         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1822         data->acregmin = nfss->acregmin / HZ;
1823         data->acregmax = nfss->acregmax / HZ;
1824         data->acdirmin = nfss->acdirmin / HZ;
1825         data->acdirmax = nfss->acdirmax / HZ;
1826         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1827         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1828         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1829                 data->nfs_server.addrlen);
1830
1831         /* overwrite those values with any that were specified */
1832         error = nfs_parse_mount_options((char *)options, data);
1833         if (error < 0)
1834                 goto out;
1835
1836         /* compare new mount options with old ones */
1837         error = nfs_compare_remount_data(nfss, data);
1838 out:
1839         kfree(data);
1840         unlock_kernel();
1841         return error;
1842 }
1843
1844 /*
1845  * Initialise the common bits of the superblock
1846  */
1847 static inline void nfs_initialise_sb(struct super_block *sb)
1848 {
1849         struct nfs_server *server = NFS_SB(sb);
1850
1851         sb->s_magic = NFS_SUPER_MAGIC;
1852
1853         /* We probably want something more informative here */
1854         snprintf(sb->s_id, sizeof(sb->s_id),
1855                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1856
1857         if (sb->s_blocksize == 0)
1858                 sb->s_blocksize = nfs_block_bits(server->wsize,
1859                                                  &sb->s_blocksize_bits);
1860
1861         if (server->flags & NFS_MOUNT_NOAC)
1862                 sb->s_flags |= MS_SYNCHRONOUS;
1863
1864         nfs_super_set_maxbytes(sb, server->maxfilesize);
1865 }
1866
1867 /*
1868  * Finish setting up an NFS2/3 superblock
1869  */
1870 static void nfs_fill_super(struct super_block *sb,
1871                            struct nfs_parsed_mount_data *data)
1872 {
1873         struct nfs_server *server = NFS_SB(sb);
1874
1875         sb->s_blocksize_bits = 0;
1876         sb->s_blocksize = 0;
1877         if (data->bsize)
1878                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1879
1880         if (server->flags & NFS_MOUNT_VER3) {
1881                 /* The VFS shouldn't apply the umask to mode bits. We will do
1882                  * so ourselves when necessary.
1883                  */
1884                 sb->s_flags |= MS_POSIXACL;
1885                 sb->s_time_gran = 1;
1886         }
1887
1888         sb->s_op = &nfs_sops;
1889         nfs_initialise_sb(sb);
1890 }
1891
1892 /*
1893  * Finish setting up a cloned NFS2/3 superblock
1894  */
1895 static void nfs_clone_super(struct super_block *sb,
1896                             const struct super_block *old_sb)
1897 {
1898         struct nfs_server *server = NFS_SB(sb);
1899
1900         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1901         sb->s_blocksize = old_sb->s_blocksize;
1902         sb->s_maxbytes = old_sb->s_maxbytes;
1903
1904         if (server->flags & NFS_MOUNT_VER3) {
1905                 /* The VFS shouldn't apply the umask to mode bits. We will do
1906                  * so ourselves when necessary.
1907                  */
1908                 sb->s_flags |= MS_POSIXACL;
1909                 sb->s_time_gran = 1;
1910         }
1911
1912         sb->s_op = old_sb->s_op;
1913         nfs_initialise_sb(sb);
1914 }
1915
1916 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1917 {
1918         const struct nfs_server *a = s->s_fs_info;
1919         const struct rpc_clnt *clnt_a = a->client;
1920         const struct rpc_clnt *clnt_b = b->client;
1921
1922         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1923                 goto Ebusy;
1924         if (a->nfs_client != b->nfs_client)
1925                 goto Ebusy;
1926         if (a->flags != b->flags)
1927                 goto Ebusy;
1928         if (a->wsize != b->wsize)
1929                 goto Ebusy;
1930         if (a->rsize != b->rsize)
1931                 goto Ebusy;
1932         if (a->acregmin != b->acregmin)
1933                 goto Ebusy;
1934         if (a->acregmax != b->acregmax)
1935                 goto Ebusy;
1936         if (a->acdirmin != b->acdirmin)
1937                 goto Ebusy;
1938         if (a->acdirmax != b->acdirmax)
1939                 goto Ebusy;
1940         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1941                 goto Ebusy;
1942         return 1;
1943 Ebusy:
1944         return 0;
1945 }
1946
1947 struct nfs_sb_mountdata {
1948         struct nfs_server *server;
1949         int mntflags;
1950 };
1951
1952 static int nfs_set_super(struct super_block *s, void *data)
1953 {
1954         struct nfs_sb_mountdata *sb_mntdata = data;
1955         struct nfs_server *server = sb_mntdata->server;
1956         int ret;
1957
1958         s->s_flags = sb_mntdata->mntflags;
1959         s->s_fs_info = server;
1960         ret = set_anon_super(s, server);
1961         if (ret == 0)
1962                 server->s_dev = s->s_dev;
1963         return ret;
1964 }
1965
1966 static int nfs_compare_super_address(struct nfs_server *server1,
1967                                      struct nfs_server *server2)
1968 {
1969         struct sockaddr *sap1, *sap2;
1970
1971         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1972         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1973
1974         if (sap1->sa_family != sap2->sa_family)
1975                 return 0;
1976
1977         switch (sap1->sa_family) {
1978         case AF_INET: {
1979                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1980                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1981                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1982                         return 0;
1983                 if (sin1->sin_port != sin2->sin_port)
1984                         return 0;
1985                 break;
1986         }
1987         case AF_INET6: {
1988                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1989                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1990                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1991                         return 0;
1992                 if (sin1->sin6_port != sin2->sin6_port)
1993                         return 0;
1994                 break;
1995         }
1996         default:
1997                 return 0;
1998         }
1999
2000         return 1;
2001 }
2002
2003 static int nfs_compare_super(struct super_block *sb, void *data)
2004 {
2005         struct nfs_sb_mountdata *sb_mntdata = data;
2006         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2007         int mntflags = sb_mntdata->mntflags;
2008
2009         if (!nfs_compare_super_address(old, server))
2010                 return 0;
2011         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2012         if (old->flags & NFS_MOUNT_UNSHARED)
2013                 return 0;
2014         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2015                 return 0;
2016         return nfs_compare_mount_options(sb, server, mntflags);
2017 }
2018
2019 static int nfs_bdi_register(struct nfs_server *server)
2020 {
2021         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2022 }
2023
2024 static int nfs_get_sb(struct file_system_type *fs_type,
2025         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2026 {
2027         struct nfs_server *server = NULL;
2028         struct super_block *s;
2029         struct nfs_parsed_mount_data *data;
2030         struct nfs_fh *mntfh;
2031         struct dentry *mntroot;
2032         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2033         struct nfs_sb_mountdata sb_mntdata = {
2034                 .mntflags = flags,
2035         };
2036         int error = -ENOMEM;
2037
2038         data = kzalloc(sizeof(*data), GFP_KERNEL);
2039         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2040         if (data == NULL || mntfh == NULL)
2041                 goto out_free_fh;
2042
2043         security_init_mnt_opts(&data->lsm_opts);
2044
2045         /* Validate the mount data */
2046         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2047         if (error < 0)
2048                 goto out;
2049
2050         /* Get a volume representation */
2051         server = nfs_create_server(data, mntfh);
2052         if (IS_ERR(server)) {
2053                 error = PTR_ERR(server);
2054                 goto out;
2055         }
2056         sb_mntdata.server = server;
2057
2058         if (server->flags & NFS_MOUNT_UNSHARED)
2059                 compare_super = NULL;
2060
2061         /* Get a superblock - note that we may end up sharing one that already exists */
2062         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2063         if (IS_ERR(s)) {
2064                 error = PTR_ERR(s);
2065                 goto out_err_nosb;
2066         }
2067
2068         if (s->s_fs_info != server) {
2069                 nfs_free_server(server);
2070                 server = NULL;
2071         } else {
2072                 error = nfs_bdi_register(server);
2073                 if (error)
2074                         goto error_splat_super;
2075         }
2076
2077         if (!s->s_root) {
2078                 /* initial superblock/root creation */
2079                 nfs_fill_super(s, data);
2080                 nfs_fscache_get_super_cookie(s, data);
2081         }
2082
2083         mntroot = nfs_get_root(s, mntfh);
2084         if (IS_ERR(mntroot)) {
2085                 error = PTR_ERR(mntroot);
2086                 goto error_splat_super;
2087         }
2088
2089         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2090         if (error)
2091                 goto error_splat_root;
2092
2093         s->s_flags |= MS_ACTIVE;
2094         mnt->mnt_sb = s;
2095         mnt->mnt_root = mntroot;
2096         error = 0;
2097
2098 out:
2099         kfree(data->nfs_server.hostname);
2100         kfree(data->mount_server.hostname);
2101         kfree(data->fscache_uniq);
2102         security_free_mnt_opts(&data->lsm_opts);
2103 out_free_fh:
2104         kfree(mntfh);
2105         kfree(data);
2106         return error;
2107
2108 out_err_nosb:
2109         nfs_free_server(server);
2110         goto out;
2111
2112 error_splat_root:
2113         dput(mntroot);
2114 error_splat_super:
2115         deactivate_locked_super(s);
2116         goto out;
2117 }
2118
2119 /*
2120  * Destroy an NFS2/3 superblock
2121  */
2122 static void nfs_kill_super(struct super_block *s)
2123 {
2124         struct nfs_server *server = NFS_SB(s);
2125
2126         bdi_unregister(&server->backing_dev_info);
2127         kill_anon_super(s);
2128         nfs_fscache_release_super_cookie(s);
2129         nfs_free_server(server);
2130 }
2131
2132 /*
2133  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2134  */
2135 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2136                            const char *dev_name, void *raw_data,
2137                            struct vfsmount *mnt)
2138 {
2139         struct nfs_clone_mount *data = raw_data;
2140         struct super_block *s;
2141         struct nfs_server *server;
2142         struct dentry *mntroot;
2143         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2144         struct nfs_sb_mountdata sb_mntdata = {
2145                 .mntflags = flags,
2146         };
2147         int error;
2148
2149         dprintk("--> nfs_xdev_get_sb()\n");
2150
2151         /* create a new volume representation */
2152         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2153         if (IS_ERR(server)) {
2154                 error = PTR_ERR(server);
2155                 goto out_err_noserver;
2156         }
2157         sb_mntdata.server = server;
2158
2159         if (server->flags & NFS_MOUNT_UNSHARED)
2160                 compare_super = NULL;
2161
2162         /* Get a superblock - note that we may end up sharing one that already exists */
2163         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2164         if (IS_ERR(s)) {
2165                 error = PTR_ERR(s);
2166                 goto out_err_nosb;
2167         }
2168
2169         if (s->s_fs_info != server) {
2170                 nfs_free_server(server);
2171                 server = NULL;
2172         } else {
2173                 error = nfs_bdi_register(server);
2174                 if (error)
2175                         goto error_splat_super;
2176         }
2177
2178         if (!s->s_root) {
2179                 /* initial superblock/root creation */
2180                 nfs_clone_super(s, data->sb);
2181         }
2182
2183         mntroot = nfs_get_root(s, data->fh);
2184         if (IS_ERR(mntroot)) {
2185                 error = PTR_ERR(mntroot);
2186                 goto error_splat_super;
2187         }
2188         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2189                 dput(mntroot);
2190                 error = -ESTALE;
2191                 goto error_splat_super;
2192         }
2193
2194         s->s_flags |= MS_ACTIVE;
2195         mnt->mnt_sb = s;
2196         mnt->mnt_root = mntroot;
2197
2198         /* clone any lsm security options from the parent to the new sb */
2199         security_sb_clone_mnt_opts(data->sb, s);
2200
2201         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2202         return 0;
2203
2204 out_err_nosb:
2205         nfs_free_server(server);
2206 out_err_noserver:
2207         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2208         return error;
2209
2210 error_splat_super:
2211         deactivate_locked_super(s);
2212         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2213         return error;
2214 }
2215
2216 #ifdef CONFIG_NFS_V4
2217
2218 /*
2219  * Finish setting up a cloned NFS4 superblock
2220  */
2221 static void nfs4_clone_super(struct super_block *sb,
2222                             const struct super_block *old_sb)
2223 {
2224         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2225         sb->s_blocksize = old_sb->s_blocksize;
2226         sb->s_maxbytes = old_sb->s_maxbytes;
2227         sb->s_time_gran = 1;
2228         sb->s_op = old_sb->s_op;
2229         nfs_initialise_sb(sb);
2230 }
2231
2232 /*
2233  * Set up an NFS4 superblock
2234  */
2235 static void nfs4_fill_super(struct super_block *sb)
2236 {
2237         sb->s_time_gran = 1;
2238         sb->s_op = &nfs4_sops;
2239         nfs_initialise_sb(sb);
2240 }
2241
2242 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2243 {
2244         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2245 }
2246
2247 /*
2248  * Validate NFSv4 mount options
2249  */
2250 static int nfs4_validate_mount_data(void *options,
2251                                     struct nfs_parsed_mount_data *args,
2252                                     const char *dev_name)
2253 {
2254         struct sockaddr_in *ap;
2255         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2256         char *c;
2257
2258         if (data == NULL)
2259                 goto out_no_data;
2260
2261         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2262         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2263         args->acregmin          = NFS_DEF_ACREGMIN;
2264         args->acregmax          = NFS_DEF_ACREGMAX;
2265         args->acdirmin          = NFS_DEF_ACDIRMIN;
2266         args->acdirmax          = NFS_DEF_ACDIRMAX;
2267         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2268         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2269         args->auth_flavor_len   = 1;
2270         args->minorversion      = 0;
2271
2272         switch (data->version) {
2273         case 1:
2274                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2275                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2276                         goto out_no_address;
2277                 if (data->host_addrlen == 0)
2278                         goto out_no_address;
2279                 args->nfs_server.addrlen = data->host_addrlen;
2280                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2281                         return -EFAULT;
2282                 if (!nfs_verify_server_address((struct sockaddr *)
2283                                                 &args->nfs_server.address))
2284                         goto out_no_address;
2285
2286                 if (data->auth_flavourlen) {
2287                         if (data->auth_flavourlen > 1)
2288                                 goto out_inval_auth;
2289                         if (copy_from_user(&args->auth_flavors[0],
2290                                            data->auth_flavours,
2291                                            sizeof(args->auth_flavors[0])))
2292                                 return -EFAULT;
2293                 }
2294
2295                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2296                 if (IS_ERR(c))
2297                         return PTR_ERR(c);
2298                 args->nfs_server.hostname = c;
2299
2300                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2301                 if (IS_ERR(c))
2302                         return PTR_ERR(c);
2303                 args->nfs_server.export_path = c;
2304                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2305
2306                 c = strndup_user(data->client_addr.data, 16);
2307                 if (IS_ERR(c))
2308                         return PTR_ERR(c);
2309                 args->client_address = c;
2310
2311                 /*
2312                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2313                  * can deal with.
2314                  */
2315
2316                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2317                 args->rsize     = data->rsize;
2318                 args->wsize     = data->wsize;
2319                 args->timeo     = data->timeo;
2320                 args->retrans   = data->retrans;
2321                 args->acregmin  = data->acregmin;
2322                 args->acregmax  = data->acregmax;
2323                 args->acdirmin  = data->acdirmin;
2324                 args->acdirmax  = data->acdirmax;
2325                 args->nfs_server.protocol = data->proto;
2326                 nfs_validate_transport_protocol(args);
2327
2328                 break;
2329         default: {
2330                 int status;
2331
2332                 if (nfs_parse_mount_options((char *)options, args) == 0)
2333                         return -EINVAL;
2334
2335                 if (!nfs_verify_server_address((struct sockaddr *)
2336                                                 &args->nfs_server.address))
2337                         return -EINVAL;
2338
2339                 rpc_set_port((struct sockaddr *)&args->nfs_server.address,
2340                                 args->nfs_server.port);
2341
2342                 nfs_validate_transport_protocol(args);
2343
2344                 nfs4_validate_mount_flags(args);
2345
2346                 if (args->auth_flavor_len > 1)
2347                         goto out_inval_auth;
2348
2349                 if (args->client_address == NULL)
2350                         goto out_no_client_address;
2351
2352                 status = nfs_parse_devname(dev_name,
2353                                            &args->nfs_server.hostname,
2354                                            NFS4_MAXNAMLEN,
2355                                            &args->nfs_server.export_path,
2356                                            NFS4_MAXPATHLEN);
2357                 if (status < 0)
2358                         return status;
2359
2360                 break;
2361                 }
2362         }
2363
2364         return 0;
2365
2366 out_no_data:
2367         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2368         return -EINVAL;
2369
2370 out_inval_auth:
2371         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2372                  data->auth_flavourlen);
2373         return -EINVAL;
2374
2375 out_no_address:
2376         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2377         return -EINVAL;
2378
2379 out_no_client_address:
2380         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2381         return -EINVAL;
2382 }
2383
2384 /*
2385  * Get the superblock for the NFS4 root partition
2386  */
2387 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2388         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2389 {
2390         struct nfs_parsed_mount_data *data = raw_data;
2391         struct super_block *s;
2392         struct nfs_server *server;
2393         struct nfs_fh *mntfh;
2394         struct dentry *mntroot;
2395         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2396         struct nfs_sb_mountdata sb_mntdata = {
2397                 .mntflags = flags,
2398         };
2399         int error = -ENOMEM;
2400
2401         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2402         if (data == NULL || mntfh == NULL)
2403                 goto out_free_fh;
2404
2405         security_init_mnt_opts(&data->lsm_opts);
2406
2407         /* Get a volume representation */
2408         server = nfs4_create_server(data, mntfh);
2409         if (IS_ERR(server)) {
2410                 error = PTR_ERR(server);
2411                 goto out;
2412         }
2413         sb_mntdata.server = server;
2414
2415         if (server->flags & NFS4_MOUNT_UNSHARED)
2416                 compare_super = NULL;
2417
2418         /* Get a superblock - note that we may end up sharing one that already exists */
2419         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2420         if (IS_ERR(s)) {
2421                 error = PTR_ERR(s);
2422                 goto out_free;
2423         }
2424
2425         if (s->s_fs_info != server) {
2426                 nfs_free_server(server);
2427                 server = NULL;
2428         } else {
2429                 error = nfs_bdi_register(server);
2430                 if (error)
2431                         goto error_splat_super;
2432         }
2433
2434         if (!s->s_root) {
2435                 /* initial superblock/root creation */
2436                 nfs4_fill_super(s);
2437                 nfs_fscache_get_super_cookie(s, data);
2438         }
2439
2440         mntroot = nfs4_get_root(s, mntfh);
2441         if (IS_ERR(mntroot)) {
2442                 error = PTR_ERR(mntroot);
2443                 goto error_splat_super;
2444         }
2445
2446         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2447         if (error)
2448                 goto error_splat_root;
2449
2450         s->s_flags |= MS_ACTIVE;
2451         mnt->mnt_sb = s;
2452         mnt->mnt_root = mntroot;
2453         error = 0;
2454
2455 out:
2456         security_free_mnt_opts(&data->lsm_opts);
2457 out_free_fh:
2458         kfree(mntfh);
2459         return error;
2460
2461 out_free:
2462         nfs_free_server(server);
2463         goto out;
2464
2465 error_splat_root:
2466         dput(mntroot);
2467 error_splat_super:
2468         deactivate_locked_super(s);
2469         goto out;
2470 }
2471
2472 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2473                 int flags, void *data, const char *hostname)
2474 {
2475         struct vfsmount *root_mnt;
2476         char *root_devname;
2477         size_t len;
2478
2479         len = strlen(hostname) + 3;
2480         root_devname = kmalloc(len, GFP_KERNEL);
2481         if (root_devname == NULL)
2482                 return ERR_PTR(-ENOMEM);
2483         snprintf(root_devname, len, "%s:/", hostname);
2484         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2485         kfree(root_devname);
2486         return root_mnt;
2487 }
2488
2489 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2490 {
2491         char *page = (char *) __get_free_page(GFP_KERNEL);
2492         char *devname, *tmp;
2493
2494         if (page == NULL)
2495                 return;
2496         devname = nfs_path(path->mnt->mnt_devname,
2497                         path->mnt->mnt_root, path->dentry,
2498                         page, PAGE_SIZE);
2499         if (devname == NULL)
2500                 goto out_freepage;
2501         tmp = kstrdup(devname, GFP_KERNEL);
2502         if (tmp == NULL)
2503                 goto out_freepage;
2504         kfree(mnt->mnt_devname);
2505         mnt->mnt_devname = tmp;
2506 out_freepage:
2507         free_page((unsigned long)page);
2508 }
2509
2510 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2511                 const char *export_path, struct vfsmount *mnt_target)
2512 {
2513         struct mnt_namespace *ns_private;
2514         struct nameidata nd;
2515         struct super_block *s;
2516         int ret;
2517
2518         ns_private = create_mnt_ns(root_mnt);
2519         ret = PTR_ERR(ns_private);
2520         if (IS_ERR(ns_private))
2521                 goto out_mntput;
2522
2523         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2524                         export_path, LOOKUP_FOLLOW, &nd);
2525
2526         put_mnt_ns(ns_private);
2527
2528         if (ret != 0)
2529                 goto out_err;
2530
2531         s = nd.path.mnt->mnt_sb;
2532         atomic_inc(&s->s_active);
2533         mnt_target->mnt_sb = s;
2534         mnt_target->mnt_root = dget(nd.path.dentry);
2535
2536         /* Correct the device pathname */
2537         nfs_fix_devname(&nd.path, mnt_target);
2538
2539         path_put(&nd.path);
2540         down_write(&s->s_umount);
2541         return 0;
2542 out_mntput:
2543         mntput(root_mnt);
2544 out_err:
2545         return ret;
2546 }
2547
2548 /*
2549  * Get the superblock for an NFS4 mountpoint
2550  */
2551 static int nfs4_get_sb(struct file_system_type *fs_type,
2552         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2553 {
2554         struct nfs_parsed_mount_data *data;
2555         char *export_path;
2556         struct vfsmount *root_mnt;
2557         int error = -ENOMEM;
2558
2559         data = kzalloc(sizeof(*data), GFP_KERNEL);
2560         if (data == NULL)
2561                 goto out_free_data;
2562
2563         /* Validate the mount data */
2564         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2565         if (error < 0)
2566                 goto out;
2567
2568         export_path = data->nfs_server.export_path;
2569         data->nfs_server.export_path = "/";
2570         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2571                         data->nfs_server.hostname);
2572         data->nfs_server.export_path = export_path;
2573
2574         error = PTR_ERR(root_mnt);
2575         if (IS_ERR(root_mnt))
2576                 goto out;
2577
2578         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2579
2580 out:
2581         kfree(data->client_address);
2582         kfree(data->nfs_server.export_path);
2583         kfree(data->nfs_server.hostname);
2584         kfree(data->fscache_uniq);
2585 out_free_data:
2586         kfree(data);
2587         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2588                         error != 0 ? " [error]" : "");
2589         return error;
2590 }
2591
2592 static void nfs4_kill_super(struct super_block *sb)
2593 {
2594         struct nfs_server *server = NFS_SB(sb);
2595
2596         dprintk("--> %s\n", __func__);
2597         nfs_super_return_all_delegations(sb);
2598         kill_anon_super(sb);
2599         nfs4_renewd_prepare_shutdown(server);
2600         nfs_fscache_release_super_cookie(sb);
2601         nfs_free_server(server);
2602         dprintk("<-- %s\n", __func__);
2603 }
2604
2605 /*
2606  * Clone an NFS4 server record on xdev traversal (FSID-change)
2607  */
2608 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2609                             const char *dev_name, void *raw_data,
2610                             struct vfsmount *mnt)
2611 {
2612         struct nfs_clone_mount *data = raw_data;
2613         struct super_block *s;
2614         struct nfs_server *server;
2615         struct dentry *mntroot;
2616         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2617         struct nfs_sb_mountdata sb_mntdata = {
2618                 .mntflags = flags,
2619         };
2620         int error;
2621
2622         dprintk("--> nfs4_xdev_get_sb()\n");
2623
2624         /* create a new volume representation */
2625         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2626         if (IS_ERR(server)) {
2627                 error = PTR_ERR(server);
2628                 goto out_err_noserver;
2629         }
2630         sb_mntdata.server = server;
2631
2632         if (server->flags & NFS4_MOUNT_UNSHARED)
2633                 compare_super = NULL;
2634
2635         /* Get a superblock - note that we may end up sharing one that already exists */
2636         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2637         if (IS_ERR(s)) {
2638                 error = PTR_ERR(s);
2639                 goto out_err_nosb;
2640         }
2641
2642         if (s->s_fs_info != server) {
2643                 nfs_free_server(server);
2644                 server = NULL;
2645         } else {
2646                 error = nfs_bdi_register(server);
2647                 if (error)
2648                         goto error_splat_super;
2649         }
2650
2651         if (!s->s_root) {
2652                 /* initial superblock/root creation */
2653                 nfs4_clone_super(s, data->sb);
2654         }
2655
2656         mntroot = nfs4_get_root(s, data->fh);
2657         if (IS_ERR(mntroot)) {
2658                 error = PTR_ERR(mntroot);
2659                 goto error_splat_super;
2660         }
2661         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2662                 dput(mntroot);
2663                 error = -ESTALE;
2664                 goto error_splat_super;
2665         }
2666
2667         s->s_flags |= MS_ACTIVE;
2668         mnt->mnt_sb = s;
2669         mnt->mnt_root = mntroot;
2670
2671         security_sb_clone_mnt_opts(data->sb, s);
2672
2673         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2674         return 0;
2675
2676 out_err_nosb:
2677         nfs_free_server(server);
2678 out_err_noserver:
2679         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2680         return error;
2681
2682 error_splat_super:
2683         deactivate_locked_super(s);
2684         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2685         return error;
2686 }
2687
2688 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2689                 int flags, const char *dev_name, void *raw_data,
2690                 struct vfsmount *mnt)
2691 {
2692         struct nfs_clone_mount *data = raw_data;
2693         struct super_block *s;
2694         struct nfs_server *server;
2695         struct dentry *mntroot;
2696         struct nfs_fh mntfh;
2697         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2698         struct nfs_sb_mountdata sb_mntdata = {
2699                 .mntflags = flags,
2700         };
2701         int error;
2702
2703         dprintk("--> nfs4_referral_get_sb()\n");
2704
2705         /* create a new volume representation */
2706         server = nfs4_create_referral_server(data, &mntfh);
2707         if (IS_ERR(server)) {
2708                 error = PTR_ERR(server);
2709                 goto out_err_noserver;
2710         }
2711         sb_mntdata.server = server;
2712
2713         if (server->flags & NFS4_MOUNT_UNSHARED)
2714                 compare_super = NULL;
2715
2716         /* Get a superblock - note that we may end up sharing one that already exists */
2717         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2718         if (IS_ERR(s)) {
2719                 error = PTR_ERR(s);
2720                 goto out_err_nosb;
2721         }
2722
2723         if (s->s_fs_info != server) {
2724                 nfs_free_server(server);
2725                 server = NULL;
2726         } else {
2727                 error = nfs_bdi_register(server);
2728                 if (error)
2729                         goto error_splat_super;
2730         }
2731
2732         if (!s->s_root) {
2733                 /* initial superblock/root creation */
2734                 nfs4_fill_super(s);
2735         }
2736
2737         mntroot = nfs4_get_root(s, &mntfh);
2738         if (IS_ERR(mntroot)) {
2739                 error = PTR_ERR(mntroot);
2740                 goto error_splat_super;
2741         }
2742         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2743                 dput(mntroot);
2744                 error = -ESTALE;
2745                 goto error_splat_super;
2746         }
2747
2748         s->s_flags |= MS_ACTIVE;
2749         mnt->mnt_sb = s;
2750         mnt->mnt_root = mntroot;
2751
2752         security_sb_clone_mnt_opts(data->sb, s);
2753
2754         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2755         return 0;
2756
2757 out_err_nosb:
2758         nfs_free_server(server);
2759 out_err_noserver:
2760         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2761         return error;
2762
2763 error_splat_super:
2764         deactivate_locked_super(s);
2765         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2766         return error;
2767 }
2768
2769 /*
2770  * Create an NFS4 server record on referral traversal
2771  */
2772 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2773                 int flags, const char *dev_name, void *raw_data,
2774                 struct vfsmount *mnt)
2775 {
2776         struct nfs_clone_mount *data = raw_data;
2777         char *export_path;
2778         struct vfsmount *root_mnt;
2779         int error;
2780
2781         dprintk("--> nfs4_referral_get_sb()\n");
2782
2783         export_path = data->mnt_path;
2784         data->mnt_path = "/";
2785
2786         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2787                         flags, data, data->hostname);
2788         data->mnt_path = export_path;
2789
2790         error = PTR_ERR(root_mnt);
2791         if (IS_ERR(root_mnt))
2792                 goto out;
2793
2794         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2795 out:
2796         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2797                         error != 0 ? " [error]" : "");
2798         return error;
2799 }
2800
2801 #endif /* CONFIG_NFS_V4 */