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, Opt_v4,
  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_v4, "v4" },
 131         { Opt_udp, "udp" },
 132         { Opt_tcp, "tcp" },
 133         { Opt_rdma, "rdma" },
 134         { Opt_acl, "acl" },
 135         { Opt_noacl, "noacl" },
 136         { Opt_rdirplus, "rdirplus" },
 137         { Opt_nordirplus, "nordirplus" },
 138         { Opt_sharecache, "sharecache" },
 139         { Opt_nosharecache, "nosharecache" },
 140         { Opt_resvport, "resvport" },
 141         { Opt_noresvport, "noresvport" },
 142         { Opt_fscache, "fsc" },
 143         { Opt_fscache_uniq, "fsc=%s" },
 144         { Opt_nofscache, "nofsc" },
 145
 146         { Opt_port, "port=%s" },
 147         { Opt_rsize, "rsize=%s" },
 148         { Opt_wsize, "wsize=%s" },
 149         { Opt_bsize, "bsize=%s" },
 150         { Opt_timeo, "timeo=%s" },
 151         { Opt_retrans, "retrans=%s" },
 152         { Opt_acregmin, "acregmin=%s" },
 153         { Opt_acregmax, "acregmax=%s" },
 154         { Opt_acdirmin, "acdirmin=%s" },
 155         { Opt_acdirmax, "acdirmax=%s" },
 156         { Opt_actimeo, "actimeo=%s" },
 157         { Opt_namelen, "namlen=%s" },
 158         { Opt_mountport, "mountport=%s" },
 159         { Opt_mountvers, "mountvers=%s" },
 160         { Opt_nfsvers, "nfsvers=%s" },
 161         { Opt_nfsvers, "vers=%s" },
 162         { Opt_minorversion, "minorversion=%s" },
 163
 164         { Opt_sec, "sec=%s" },
 165         { Opt_proto, "proto=%s" },
 166         { Opt_mountproto, "mountproto=%s" },
 167         { Opt_addr, "addr=%s" },
 168         { Opt_clientaddr, "clientaddr=%s" },
 169         { Opt_mounthost, "mounthost=%s" },
 170         { Opt_mountaddr, "mountaddr=%s" },
 171
 172         { Opt_lookupcache, "lookupcache=%s" },
 173
 174         { Opt_err, NULL }
 175 };
 176
 177 enum {
 178         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 179
 180         Opt_xprt_err
 181 };
 182
 183 static const match_table_t nfs_xprt_protocol_tokens = {
 184         { Opt_xprt_udp, "udp" },
 185         { Opt_xprt_tcp, "tcp" },
 186         { Opt_xprt_rdma, "rdma" },
 187
 188         { Opt_xprt_err, NULL }
 189 };
 190
 191 enum {
 192         Opt_sec_none, Opt_sec_sys,
 193         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 194         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 195         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 196
 197         Opt_sec_err
 198 };
 199
 200 static const match_table_t nfs_secflavor_tokens = {
 201         { Opt_sec_none, "none" },
 202         { Opt_sec_none, "null" },
 203         { Opt_sec_sys, "sys" },
 204
 205         { Opt_sec_krb5, "krb5" },
 206         { Opt_sec_krb5i, "krb5i" },
 207         { Opt_sec_krb5p, "krb5p" },
 208
 209         { Opt_sec_lkey, "lkey" },
 210         { Opt_sec_lkeyi, "lkeyi" },
 211         { Opt_sec_lkeyp, "lkeyp" },
 212
 213         { Opt_sec_spkm, "spkm3" },
 214         { Opt_sec_spkmi, "spkm3i" },
 215         { Opt_sec_spkmp, "spkm3p" },
 216
 217         { Opt_sec_err, NULL }
 218 };
 219
 220 enum {
 221         Opt_lookupcache_all, Opt_lookupcache_positive,
 222         Opt_lookupcache_none,
 223
 224         Opt_lookupcache_err
 225 };
 226
 227 static match_table_t nfs_lookupcache_tokens = {
 228         { Opt_lookupcache_all, "all" },
 229         { Opt_lookupcache_positive, "pos" },
 230         { Opt_lookupcache_positive, "positive" },
 231         { Opt_lookupcache_none, "none" },
 232
 233         { Opt_lookupcache_err, NULL }
 234 };
 235
 236
 237 static void nfs_umount_begin(struct super_block *);
 238 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 239 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 240 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 241 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 242 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 243                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 244 static void nfs_kill_super(struct super_block *);
 245 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 246
 247 static struct file_system_type nfs_fs_type = {
 248         .owner          = THIS_MODULE,
 249         .name           = "nfs",
 250         .get_sb         = nfs_get_sb,
 251         .kill_sb        = nfs_kill_super,
 252         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 253 };
 254
 255 struct file_system_type nfs_xdev_fs_type = {
 256         .owner          = THIS_MODULE,
 257         .name           = "nfs",
 258         .get_sb         = nfs_xdev_get_sb,
 259         .kill_sb        = nfs_kill_super,
 260         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 261 };
 262
 263 static const struct super_operations nfs_sops = {
 264         .alloc_inode    = nfs_alloc_inode,
 265         .destroy_inode  = nfs_destroy_inode,
 266         .write_inode    = nfs_write_inode,
 267         .statfs         = nfs_statfs,
 268         .clear_inode    = nfs_clear_inode,
 269         .umount_begin   = nfs_umount_begin,
 270         .show_options   = nfs_show_options,
 271         .show_stats     = nfs_show_stats,
 272         .remount_fs     = nfs_remount,
 273 };
 274
 275 #ifdef CONFIG_NFS_V4
 276 static int nfs4_validate_text_mount_data(void *options,
 277         struct nfs_parsed_mount_data *args, const char *dev_name);
 278 static int nfs4_try_mount(int flags, const char *dev_name,
 279         struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
 280 static int nfs4_get_sb(struct file_system_type *fs_type,
 281         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 282 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 283         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 284 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 285         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 286 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 287         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 288 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
 289         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 290 static void nfs4_kill_super(struct super_block *sb);
 291
 292 static struct file_system_type nfs4_fs_type = {
 293         .owner          = THIS_MODULE,
 294         .name           = "nfs4",
 295         .get_sb         = nfs4_get_sb,
 296         .kill_sb        = nfs4_kill_super,
 297         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 298 };
 299
 300 static struct file_system_type nfs4_remote_fs_type = {
 301         .owner          = THIS_MODULE,
 302         .name           = "nfs4",
 303         .get_sb         = nfs4_remote_get_sb,
 304         .kill_sb        = nfs4_kill_super,
 305         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 306 };
 307
 308 struct file_system_type nfs4_xdev_fs_type = {
 309         .owner          = THIS_MODULE,
 310         .name           = "nfs4",
 311         .get_sb         = nfs4_xdev_get_sb,
 312         .kill_sb        = nfs4_kill_super,
 313         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 314 };
 315
 316 static struct file_system_type nfs4_remote_referral_fs_type = {
 317         .owner          = THIS_MODULE,
 318         .name           = "nfs4",
 319         .get_sb         = nfs4_remote_referral_get_sb,
 320         .kill_sb        = nfs4_kill_super,
 321         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 322 };
 323
 324 struct file_system_type nfs4_referral_fs_type = {
 325         .owner          = THIS_MODULE,
 326         .name           = "nfs4",
 327         .get_sb         = nfs4_referral_get_sb,
 328         .kill_sb        = nfs4_kill_super,
 329         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 330 };
 331
 332 static const struct super_operations nfs4_sops = {
 333         .alloc_inode    = nfs_alloc_inode,
 334         .destroy_inode  = nfs_destroy_inode,
 335         .write_inode    = nfs_write_inode,
 336         .statfs         = nfs_statfs,
 337         .clear_inode    = nfs4_clear_inode,
 338         .umount_begin   = nfs_umount_begin,
 339         .show_options   = nfs_show_options,
 340         .show_stats     = nfs_show_stats,
 341         .remount_fs     = nfs_remount,
 342 };
 343 #endif
 344
 345 static struct shrinker acl_shrinker = {
 346         .shrink         = nfs_access_cache_shrinker,
 347         .seeks          = DEFAULT_SEEKS,
 348 };
 349
 350 /*
 351  * Register the NFS filesystems
 352  */
 353 int __init register_nfs_fs(void)
 354 {
 355         int ret;
 356
 357         ret = register_filesystem(&nfs_fs_type);
 358         if (ret < 0)
 359                 goto error_0;
 360
 361         ret = nfs_register_sysctl();
 362         if (ret < 0)
 363                 goto error_1;
 364 #ifdef CONFIG_NFS_V4
 365         ret = register_filesystem(&nfs4_fs_type);
 366         if (ret < 0)
 367                 goto error_2;
 368 #endif
 369         register_shrinker(&acl_shrinker);
 370         return 0;
 371
 372 #ifdef CONFIG_NFS_V4
 373 error_2:
 374         nfs_unregister_sysctl();
 375 #endif
 376 error_1:
 377         unregister_filesystem(&nfs_fs_type);
 378 error_0:
 379         return ret;
 380 }
 381
 382 /*
 383  * Unregister the NFS filesystems
 384  */
 385 void __exit unregister_nfs_fs(void)
 386 {
 387         unregister_shrinker(&acl_shrinker);
 388 #ifdef CONFIG_NFS_V4
 389         unregister_filesystem(&nfs4_fs_type);
 390 #endif
 391         nfs_unregister_sysctl();
 392         unregister_filesystem(&nfs_fs_type);
 393 }
 394
 395 void nfs_sb_active(struct super_block *sb)
 396 {
 397         struct nfs_server *server = NFS_SB(sb);
 398
 399         if (atomic_inc_return(&server->active) == 1)
 400                 atomic_inc(&sb->s_active);
 401 }
 402
 403 void nfs_sb_deactive(struct super_block *sb)
 404 {
 405         struct nfs_server *server = NFS_SB(sb);
 406
 407         if (atomic_dec_and_test(&server->active))
 408                 deactivate_super(sb);
 409 }
 410
 411 /*
 412  * Deliver file system statistics to userspace
 413  */
 414 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 415 {
 416         struct nfs_server *server = NFS_SB(dentry->d_sb);
 417         unsigned char blockbits;
 418         unsigned long blockres;
 419         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 420         struct nfs_fattr fattr;
 421         struct nfs_fsstat res = {
 422                         .fattr = &fattr,
 423         };
 424         int error;
 425
 426         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 427         if (error < 0)
 428                 goto out_err;
 429         buf->f_type = NFS_SUPER_MAGIC;
 430
 431         /*
 432          * Current versions of glibc do not correctly handle the
 433          * case where f_frsize != f_bsize.  Eventually we want to
 434          * report the value of wtmult in this field.
 435          */
 436         buf->f_frsize = dentry->d_sb->s_blocksize;
 437
 438         /*
 439          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 440          * are reported in units of f_frsize.  Linux hasn't had
 441          * an f_frsize field in its statfs struct until recently,
 442          * thus historically Linux's sys_statfs reports these
 443          * fields in units of f_bsize.
 444          */
 445         buf->f_bsize = dentry->d_sb->s_blocksize;
 446         blockbits = dentry->d_sb->s_blocksize_bits;
 447         blockres = (1 << blockbits) - 1;
 448         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 449         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 450         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 451
 452         buf->f_files = res.tfiles;
 453         buf->f_ffree = res.afiles;
 454
 455         buf->f_namelen = server->namelen;
 456
 457         return 0;
 458
 459  out_err:
 460         dprintk("%s: statfs error = %d\n", __func__, -error);
 461         return error;
 462 }
 463
 464 /*
 465  * Map the security flavour number to a name
 466  */
 467 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 468 {
 469         static const struct {
 470                 rpc_authflavor_t flavour;
 471                 const char *str;
 472         } sec_flavours[] = {
 473                 { RPC_AUTH_NULL, "null" },
 474                 { RPC_AUTH_UNIX, "sys" },
 475                 { RPC_AUTH_GSS_KRB5, "krb5" },
 476                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 477                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 478                 { RPC_AUTH_GSS_LKEY, "lkey" },
 479                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 480                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 481                 { RPC_AUTH_GSS_SPKM, "spkm" },
 482                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 483                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 484                 { UINT_MAX, "unknown" }
 485         };
 486         int i;
 487
 488         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 489                 if (sec_flavours[i].flavour == flavour)
 490                         break;
 491         }
 492         return sec_flavours[i].str;
 493 }
 494
 495 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 496                                     int showdefaults)
 497 {
 498         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 499
 500         switch (sap->sa_family) {
 501         case AF_INET: {
 502                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 503                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 504                 break;
 505         }
 506         case AF_INET6: {
 507                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 508                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 509                 break;
 510         }
 511         default:
 512                 if (showdefaults)
 513                         seq_printf(m, ",mountaddr=unspecified");
 514         }
 515
 516         if (nfss->mountd_version || showdefaults)
 517                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 518         if (nfss->mountd_port || showdefaults)
 519                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 520
 521         switch (nfss->mountd_protocol) {
 522         case IPPROTO_UDP:
 523                 seq_printf(m, ",mountproto=udp");
 524                 break;
 525         case IPPROTO_TCP:
 526                 seq_printf(m, ",mountproto=tcp");
 527                 break;
 528         default:
 529                 if (showdefaults)
 530                         seq_printf(m, ",mountproto=auto");
 531         }
 532 }
 533
 534 /*
 535  * Describe the mount options in force on this server representation
 536  */
 537 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 538                                    int showdefaults)
 539 {
 540         static const struct proc_nfs_info {
 541                 int flag;
 542                 const char *str;
 543                 const char *nostr;
 544         } nfs_info[] = {
 545                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 546                 { NFS_MOUNT_POSIX, ",posix", "" },
 547                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 548                 { NFS_MOUNT_NOAC, ",noac", "" },
 549                 { NFS_MOUNT_NONLM, ",nolock", "" },
 550                 { NFS_MOUNT_NOACL, ",noacl", "" },
 551                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 552                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 553                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 554                 { 0, NULL, NULL }
 555         };
 556         const struct proc_nfs_info *nfs_infop;
 557         struct nfs_client *clp = nfss->nfs_client;
 558         u32 version = clp->rpc_ops->version;
 559
 560         seq_printf(m, ",vers=%u", version);
 561         seq_printf(m, ",rsize=%u", nfss->rsize);
 562         seq_printf(m, ",wsize=%u", nfss->wsize);
 563         if (nfss->bsize != 0)
 564                 seq_printf(m, ",bsize=%u", nfss->bsize);
 565         seq_printf(m, ",namlen=%u", nfss->namelen);
 566         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 567                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 568         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 569                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 570         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 571                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 572         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 573                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 574         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 575                 if (nfss->flags & nfs_infop->flag)
 576                         seq_puts(m, nfs_infop->str);
 577                 else
 578                         seq_puts(m, nfs_infop->nostr);
 579         }
 580         seq_printf(m, ",proto=%s",
 581                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 582         if (version == 4) {
 583                 if (nfss->port != NFS_PORT)
 584                         seq_printf(m, ",port=%u", nfss->port);
 585         } else
 586                 if (nfss->port)
 587                         seq_printf(m, ",port=%u", nfss->port);
 588
 589         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 590         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 591         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 592
 593         if (version != 4)
 594                 nfs_show_mountd_options(m, nfss, showdefaults);
 595
 596 #ifdef CONFIG_NFS_V4
 597         if (clp->rpc_ops->version == 4)
 598                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 599 #endif
 600         if (nfss->options & NFS_OPTION_FSCACHE)
 601                 seq_printf(m, ",fsc");
 602 }
 603
 604 /*
 605  * Describe the mount options on this VFS mountpoint
 606  */
 607 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 608 {
 609         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 610
 611         nfs_show_mount_options(m, nfss, 0);
 612
 613         seq_printf(m, ",addr=%s",
 614                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 615                                                         RPC_DISPLAY_ADDR));
 616
 617         return 0;
 618 }
 619
 620 /*
 621  * Present statistical information for this VFS mountpoint
 622  */
 623 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 624 {
 625         int i, cpu;
 626         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 627         struct rpc_auth *auth = nfss->client->cl_auth;
 628         struct nfs_iostats totals = { };
 629
 630         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 631
 632         /*
 633          * Display all mount option settings
 634          */
 635         seq_printf(m, "\n\topts:\t");
 636         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 637         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 638         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 639         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 640         nfs_show_mount_options(m, nfss, 1);
 641
 642         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 643
 644         seq_printf(m, "\n\tcaps:\t");
 645         seq_printf(m, "caps=0x%x", nfss->caps);
 646         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 647         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 648         seq_printf(m, ",bsize=%u", nfss->bsize);
 649         seq_printf(m, ",namlen=%u", nfss->namelen);
 650
 651 #ifdef CONFIG_NFS_V4
 652         if (nfss->nfs_client->rpc_ops->version == 4) {
 653                 seq_printf(m, "\n\tnfsv4:\t");
 654                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 655                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 656                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 657         }
 658 #endif
 659
 660         /*
 661          * Display security flavor in effect for this mount
 662          */
 663         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 664         if (auth->au_flavor)
 665                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 666
 667         /*
 668          * Display superblock I/O counters
 669          */
 670         for_each_possible_cpu(cpu) {
 671                 struct nfs_iostats *stats;
 672
 673                 preempt_disable();
 674                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 675
 676                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 677                         totals.events[i] += stats->events[i];
 678                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 679                         totals.bytes[i] += stats->bytes[i];
 680 #ifdef CONFIG_NFS_FSCACHE
 681                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 682                         totals.fscache[i] += stats->fscache[i];
 683 #endif
 684
 685                 preempt_enable();
 686         }
 687
 688         seq_printf(m, "\n\tevents:\t");
 689         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 690                 seq_printf(m, "%lu ", totals.events[i]);
 691         seq_printf(m, "\n\tbytes:\t");
 692         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 693                 seq_printf(m, "%Lu ", totals.bytes[i]);
 694 #ifdef CONFIG_NFS_FSCACHE
 695         if (nfss->options & NFS_OPTION_FSCACHE) {
 696                 seq_printf(m, "\n\tfsc:\t");
 697                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 698                         seq_printf(m, "%Lu ", totals.bytes[i]);
 699         }
 700 #endif
 701         seq_printf(m, "\n");
 702
 703         rpc_print_iostats(m, nfss->client);
 704
 705         return 0;
 706 }
 707
 708 /*
 709  * Begin unmount by attempting to remove all automounted mountpoints we added
 710  * in response to xdev traversals and referrals
 711  */
 712 static void nfs_umount_begin(struct super_block *sb)
 713 {
 714         struct nfs_server *server;
 715         struct rpc_clnt *rpc;
 716
 717         lock_kernel();
 718
 719         server = NFS_SB(sb);
 720         /* -EIO all pending I/O */
 721         rpc = server->client_acl;
 722         if (!IS_ERR(rpc))
 723                 rpc_killall_tasks(rpc);
 724         rpc = server->client;
 725         if (!IS_ERR(rpc))
 726                 rpc_killall_tasks(rpc);
 727
 728         unlock_kernel();
 729 }
 730
 731 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 732 {
 733         struct nfs_parsed_mount_data *data;
 734
 735         data = kzalloc(sizeof(*data), GFP_KERNEL);
 736         if (data) {
 737                 data->rsize             = NFS_MAX_FILE_IO_SIZE;
 738                 data->wsize             = NFS_MAX_FILE_IO_SIZE;
 739                 data->acregmin          = NFS_DEF_ACREGMIN;
 740                 data->acregmax          = NFS_DEF_ACREGMAX;
 741                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 742                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 743                 data->mount_server.port = NFS_UNSPEC_PORT;
 744                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 745                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 746                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 747                 data->auth_flavor_len   = 1;
 748                 data->version           = version;
 749                 data->minorversion      = 0;
 750         }
 751         return data;
 752 }
 753
 754 /*
 755  * Sanity-check a server address provided by the mount command.
 756  *
 757  * Address family must be initialized, and address must not be
 758  * the ANY address for that family.
 759  */
 760 static int nfs_verify_server_address(struct sockaddr *addr)
 761 {
 762         switch (addr->sa_family) {
 763         case AF_INET: {
 764                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 765                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 766         }
 767         case AF_INET6: {
 768                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 769                 return !ipv6_addr_any(sa);
 770         }
 771         }
 772
 773         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 774         return 0;
 775 }
 776
 777 /*
 778  * Select between a default port value and a user-specified port value.
 779  * If a zero value is set, then autobind will be used.
 780  */
 781 static void nfs_set_port(struct sockaddr *sap, int *port,
 782                                  const unsigned short default_port)
 783 {
 784         if (*port == NFS_UNSPEC_PORT)
 785                 *port = default_port;
 786
 787         rpc_set_port(sap, *port);
 788 }
 789
 790 /*
 791  * Sanity check the NFS transport protocol.
 792  *
 793  */
 794 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 795 {
 796         switch (mnt->nfs_server.protocol) {
 797         case XPRT_TRANSPORT_UDP:
 798         case XPRT_TRANSPORT_TCP:
 799         case XPRT_TRANSPORT_RDMA:
 800                 break;
 801         default:
 802                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 803         }
 804 }
 805
 806 /*
 807  * For text based NFSv2/v3 mounts, the mount protocol transport default
 808  * settings should depend upon the specified NFS transport.
 809  */
 810 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 811 {
 812         nfs_validate_transport_protocol(mnt);
 813
 814         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 815             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 816                         return;
 817         switch (mnt->nfs_server.protocol) {
 818         case XPRT_TRANSPORT_UDP:
 819                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 820                 break;
 821         case XPRT_TRANSPORT_TCP:
 822         case XPRT_TRANSPORT_RDMA:
 823                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 824         }
 825 }
 826
 827 /*
 828  * Parse the value of the 'sec=' option.
 829  */
 830 static int nfs_parse_security_flavors(char *value,
 831                                       struct nfs_parsed_mount_data *mnt)
 832 {
 833         substring_t args[MAX_OPT_ARGS];
 834
 835         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 836
 837         switch (match_token(value, nfs_secflavor_tokens, args)) {
 838         case Opt_sec_none:
 839                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 840                 break;
 841         case Opt_sec_sys:
 842                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 843                 break;
 844         case Opt_sec_krb5:
 845                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 846                 break;
 847         case Opt_sec_krb5i:
 848                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 849                 break;
 850         case Opt_sec_krb5p:
 851                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 852                 break;
 853         case Opt_sec_lkey:
 854                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 855                 break;
 856         case Opt_sec_lkeyi:
 857                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 858                 break;
 859         case Opt_sec_lkeyp:
 860                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 861                 break;
 862         case Opt_sec_spkm:
 863                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 864                 break;
 865         case Opt_sec_spkmi:
 866                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 867                 break;
 868         case Opt_sec_spkmp:
 869                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 870                 break;
 871         default:
 872                 return 0;
 873         }
 874
 875         mnt->auth_flavor_len = 1;
 876         return 1;
 877 }
 878
 879 /*
 880  * Error-check and convert a string of mount options from user space into
 881  * a data structure.  The whole mount string is processed; bad options are
 882  * skipped as they are encountered.  If there were no errors, return 1;
 883  * otherwise return 0 (zero).
 884  */
 885 static int nfs_parse_mount_options(char *raw,
 886                                    struct nfs_parsed_mount_data *mnt)
 887 {
 888         char *p, *string, *secdata;
 889         int rc, sloppy = 0, invalid_option = 0;
 890
 891         if (!raw) {
 892                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 893                 return 1;
 894         }
 895         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 896
 897         secdata = alloc_secdata();
 898         if (!secdata)
 899                 goto out_nomem;
 900
 901         rc = security_sb_copy_data(raw, secdata);
 902         if (rc)
 903                 goto out_security_failure;
 904
 905         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 906         if (rc)
 907                 goto out_security_failure;
 908
 909         free_secdata(secdata);
 910
 911         while ((p = strsep(&raw, ",")) != NULL) {
 912                 substring_t args[MAX_OPT_ARGS];
 913                 unsigned long option;
 914                 int token;
 915
 916                 if (!*p)
 917                         continue;
 918
 919                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 920
 921                 token = match_token(p, nfs_mount_option_tokens, args);
 922                 switch (token) {
 923
 924                 /*
 925                  * boolean options:  foo/nofoo
 926                  */
 927                 case Opt_soft:
 928                         mnt->flags |= NFS_MOUNT_SOFT;
 929                         break;
 930                 case Opt_hard:
 931                         mnt->flags &= ~NFS_MOUNT_SOFT;
 932                         break;
 933                 case Opt_posix:
 934                         mnt->flags |= NFS_MOUNT_POSIX;
 935                         break;
 936                 case Opt_noposix:
 937                         mnt->flags &= ~NFS_MOUNT_POSIX;
 938                         break;
 939                 case Opt_cto:
 940                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 941                         break;
 942                 case Opt_nocto:
 943                         mnt->flags |= NFS_MOUNT_NOCTO;
 944                         break;
 945                 case Opt_ac:
 946                         mnt->flags &= ~NFS_MOUNT_NOAC;
 947                         break;
 948                 case Opt_noac:
 949                         mnt->flags |= NFS_MOUNT_NOAC;
 950                         break;
 951                 case Opt_lock:
 952                         mnt->flags &= ~NFS_MOUNT_NONLM;
 953                         break;
 954                 case Opt_nolock:
 955                         mnt->flags |= NFS_MOUNT_NONLM;
 956                         break;
 957                 case Opt_v2:
 958                         mnt->flags &= ~NFS_MOUNT_VER3;
 959                         mnt->version = 2;
 960                         break;
 961                 case Opt_v3:
 962                         mnt->flags |= NFS_MOUNT_VER3;
 963                         mnt->version = 3;
 964                         break;
 965 #ifdef CONFIG_NFS_V4
 966                 case Opt_v4:
 967                         mnt->flags &= ~NFS_MOUNT_VER3;
 968                         mnt->version = 4;
 969                         break;
 970 #endif
 971                 case Opt_udp:
 972                         mnt->flags &= ~NFS_MOUNT_TCP;
 973                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 974                         break;
 975                 case Opt_tcp:
 976                         mnt->flags |= NFS_MOUNT_TCP;
 977                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 978                         break;
 979                 case Opt_rdma:
 980                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 981                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 982                         xprt_load_transport(p);
 983                         break;
 984                 case Opt_acl:
 985                         mnt->flags &= ~NFS_MOUNT_NOACL;
 986                         break;
 987                 case Opt_noacl:
 988                         mnt->flags |= NFS_MOUNT_NOACL;
 989                         break;
 990                 case Opt_rdirplus:
 991                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 992                         break;
 993                 case Opt_nordirplus:
 994                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 995                         break;
 996                 case Opt_sharecache:
 997                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 998                         break;
 999                 case Opt_nosharecache:
1000                         mnt->flags |= NFS_MOUNT_UNSHARED;
1001                         break;
1002                 case Opt_resvport:
1003                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1004                         break;
1005                 case Opt_noresvport:
1006                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1007                         break;
1008                 case Opt_fscache:
1009                         mnt->options |= NFS_OPTION_FSCACHE;
1010                         kfree(mnt->fscache_uniq);
1011                         mnt->fscache_uniq = NULL;
1012                         break;
1013                 case Opt_nofscache:
1014                         mnt->options &= ~NFS_OPTION_FSCACHE;
1015                         kfree(mnt->fscache_uniq);
1016                         mnt->fscache_uniq = NULL;
1017                         break;
1018                 case Opt_fscache_uniq:
1019                         string = match_strdup(args);
1020                         if (!string)
1021                                 goto out_nomem;
1022                         kfree(mnt->fscache_uniq);
1023                         mnt->fscache_uniq = string;
1024                         mnt->options |= NFS_OPTION_FSCACHE;
1025                         break;
1026
1027                 /*
1028                  * options that take numeric values
1029                  */
1030                 case Opt_port:
1031                         string = match_strdup(args);
1032                         if (string == NULL)
1033                                 goto out_nomem;
1034                         rc = strict_strtoul(string, 10, &option);
1035                         kfree(string);
1036                         if (rc != 0 || option > USHORT_MAX)
1037                                 goto out_invalid_value;
1038                         mnt->nfs_server.port = option;
1039                         break;
1040                 case Opt_rsize:
1041                         string = match_strdup(args);
1042                         if (string == NULL)
1043                                 goto out_nomem;
1044                         rc = strict_strtoul(string, 10, &option);
1045                         kfree(string);
1046                         if (rc != 0)
1047                                 goto out_invalid_value;
1048                         mnt->rsize = option;
1049                         break;
1050                 case Opt_wsize:
1051                         string = match_strdup(args);
1052                         if (string == NULL)
1053                                 goto out_nomem;
1054                         rc = strict_strtoul(string, 10, &option);
1055                         kfree(string);
1056                         if (rc != 0)
1057                                 goto out_invalid_value;
1058                         mnt->wsize = option;
1059                         break;
1060                 case Opt_bsize:
1061                         string = match_strdup(args);
1062                         if (string == NULL)
1063                                 goto out_nomem;
1064                         rc = strict_strtoul(string, 10, &option);
1065                         kfree(string);
1066                         if (rc != 0)
1067                                 goto out_invalid_value;
1068                         mnt->bsize = option;
1069                         break;
1070                 case Opt_timeo:
1071                         string = match_strdup(args);
1072                         if (string == NULL)
1073                                 goto out_nomem;
1074                         rc = strict_strtoul(string, 10, &option);
1075                         kfree(string);
1076                         if (rc != 0 || option == 0)
1077                                 goto out_invalid_value;
1078                         mnt->timeo = option;
1079                         break;
1080                 case Opt_retrans:
1081                         string = match_strdup(args);
1082                         if (string == NULL)
1083                                 goto out_nomem;
1084                         rc = strict_strtoul(string, 10, &option);
1085                         kfree(string);
1086                         if (rc != 0 || option == 0)
1087                                 goto out_invalid_value;
1088                         mnt->retrans = option;
1089                         break;
1090                 case Opt_acregmin:
1091                         string = match_strdup(args);
1092                         if (string == NULL)
1093                                 goto out_nomem;
1094                         rc = strict_strtoul(string, 10, &option);
1095                         kfree(string);
1096                         if (rc != 0)
1097                                 goto out_invalid_value;
1098                         mnt->acregmin = option;
1099                         break;
1100                 case Opt_acregmax:
1101                         string = match_strdup(args);
1102                         if (string == NULL)
1103                                 goto out_nomem;
1104                         rc = strict_strtoul(string, 10, &option);
1105                         kfree(string);
1106                         if (rc != 0)
1107                                 goto out_invalid_value;
1108                         mnt->acregmax = option;
1109                         break;
1110                 case Opt_acdirmin:
1111                         string = match_strdup(args);
1112                         if (string == NULL)
1113                                 goto out_nomem;
1114                         rc = strict_strtoul(string, 10, &option);
1115                         kfree(string);
1116                         if (rc != 0)
1117                                 goto out_invalid_value;
1118                         mnt->acdirmin = option;
1119                         break;
1120                 case Opt_acdirmax:
1121                         string = match_strdup(args);
1122                         if (string == NULL)
1123                                 goto out_nomem;
1124                         rc = strict_strtoul(string, 10, &option);
1125                         kfree(string);
1126                         if (rc != 0)
1127                                 goto out_invalid_value;
1128                         mnt->acdirmax = option;
1129                         break;
1130                 case Opt_actimeo:
1131                         string = match_strdup(args);
1132                         if (string == NULL)
1133                                 goto out_nomem;
1134                         rc = strict_strtoul(string, 10, &option);
1135                         kfree(string);
1136                         if (rc != 0)
1137                                 goto out_invalid_value;
1138                         mnt->acregmin = mnt->acregmax =
1139                         mnt->acdirmin = mnt->acdirmax = option;
1140                         break;
1141                 case Opt_namelen:
1142                         string = match_strdup(args);
1143                         if (string == NULL)
1144                                 goto out_nomem;
1145                         rc = strict_strtoul(string, 10, &option);
1146                         kfree(string);
1147                         if (rc != 0)
1148                                 goto out_invalid_value;
1149                         mnt->namlen = option;
1150                         break;
1151                 case Opt_mountport:
1152                         string = match_strdup(args);
1153                         if (string == NULL)
1154                                 goto out_nomem;
1155                         rc = strict_strtoul(string, 10, &option);
1156                         kfree(string);
1157                         if (rc != 0 || option > USHORT_MAX)
1158                                 goto out_invalid_value;
1159                         mnt->mount_server.port = option;
1160                         break;
1161                 case Opt_mountvers:
1162                         string = match_strdup(args);
1163                         if (string == NULL)
1164                                 goto out_nomem;
1165                         rc = strict_strtoul(string, 10, &option);
1166                         kfree(string);
1167                         if (rc != 0 ||
1168                             option < NFS_MNT_VERSION ||
1169                             option > NFS_MNT3_VERSION)
1170                                 goto out_invalid_value;
1171                         mnt->mount_server.version = option;
1172                         break;
1173                 case Opt_nfsvers:
1174                         string = match_strdup(args);
1175                         if (string == NULL)
1176                                 goto out_nomem;
1177                         rc = strict_strtoul(string, 10, &option);
1178                         kfree(string);
1179                         if (rc != 0)
1180                                 goto out_invalid_value;
1181                         switch (option) {
1182                         case NFS2_VERSION:
1183                                 mnt->flags &= ~NFS_MOUNT_VER3;
1184                                 mnt->version = 2;
1185                                 break;
1186                         case NFS3_VERSION:
1187                                 mnt->flags |= NFS_MOUNT_VER3;
1188                                 mnt->version = 3;
1189                                 break;
1190 #ifdef CONFIG_NFS_V4
1191                         case NFS4_VERSION:
1192                                 mnt->flags &= ~NFS_MOUNT_VER3;
1193                                 mnt->version = 4;
1194                                 break;
1195 #endif
1196                         default:
1197                                 goto out_invalid_value;
1198                         }
1199                         break;
1200                 case Opt_minorversion:
1201                         string = match_strdup(args);
1202                         if (string == NULL)
1203                                 goto out_nomem;
1204                         rc = strict_strtoul(string, 10, &option);
1205                         kfree(string);
1206                         if (rc != 0)
1207                                 goto out_invalid_value;
1208                         if (option > NFS4_MAX_MINOR_VERSION)
1209                                 goto out_invalid_value;
1210                         mnt->minorversion = option;
1211                         break;
1212
1213                 /*
1214                  * options that take text values
1215                  */
1216                 case Opt_sec:
1217                         string = match_strdup(args);
1218                         if (string == NULL)
1219                                 goto out_nomem;
1220                         rc = nfs_parse_security_flavors(string, mnt);
1221                         kfree(string);
1222                         if (!rc) {
1223                                 dfprintk(MOUNT, "NFS:   unrecognized "
1224                                                 "security flavor\n");
1225                                 return 0;
1226                         }
1227                         break;
1228                 case Opt_proto:
1229                         string = match_strdup(args);
1230                         if (string == NULL)
1231                                 goto out_nomem;
1232                         token = match_token(string,
1233                                             nfs_xprt_protocol_tokens, args);
1234
1235                         switch (token) {
1236                         case Opt_xprt_udp:
1237                                 mnt->flags &= ~NFS_MOUNT_TCP;
1238                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1239                                 kfree(string);
1240                                 break;
1241                         case Opt_xprt_tcp:
1242                                 mnt->flags |= NFS_MOUNT_TCP;
1243                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1244                                 kfree(string);
1245                                 break;
1246                         case Opt_xprt_rdma:
1247                                 /* vector side protocols to TCP */
1248                                 mnt->flags |= NFS_MOUNT_TCP;
1249                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1250                                 xprt_load_transport(string);
1251                                 kfree(string);
1252                                 break;
1253                         default:
1254                                 dfprintk(MOUNT, "NFS:   unrecognized "
1255                                                 "transport protocol\n");
1256                                 return 0;
1257                         }
1258                         break;
1259                 case Opt_mountproto:
1260                         string = match_strdup(args);
1261                         if (string == NULL)
1262                                 goto out_nomem;
1263                         token = match_token(string,
1264                                             nfs_xprt_protocol_tokens, args);
1265                         kfree(string);
1266
1267                         switch (token) {
1268                         case Opt_xprt_udp:
1269                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1270                                 break;
1271                         case Opt_xprt_tcp:
1272                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1273                                 break;
1274                         case Opt_xprt_rdma: /* not used for side protocols */
1275                         default:
1276                                 dfprintk(MOUNT, "NFS:   unrecognized "
1277                                                 "transport protocol\n");
1278                                 return 0;
1279                         }
1280                         break;
1281                 case Opt_addr:
1282                         string = match_strdup(args);
1283                         if (string == NULL)
1284                                 goto out_nomem;
1285                         mnt->nfs_server.addrlen =
1286                                 rpc_pton(string, strlen(string),
1287                                         (struct sockaddr *)
1288                                         &mnt->nfs_server.address,
1289                                         sizeof(mnt->nfs_server.address));
1290                         kfree(string);
1291                         if (mnt->nfs_server.addrlen == 0)
1292                                 goto out_invalid_address;
1293                         break;
1294                 case Opt_clientaddr:
1295                         string = match_strdup(args);
1296                         if (string == NULL)
1297                                 goto out_nomem;
1298                         kfree(mnt->client_address);
1299                         mnt->client_address = string;
1300                         break;
1301                 case Opt_mounthost:
1302                         string = match_strdup(args);
1303                         if (string == NULL)
1304                                 goto out_nomem;
1305                         kfree(mnt->mount_server.hostname);
1306                         mnt->mount_server.hostname = string;
1307                         break;
1308                 case Opt_mountaddr:
1309                         string = match_strdup(args);
1310                         if (string == NULL)
1311                                 goto out_nomem;
1312                         mnt->mount_server.addrlen =
1313                                 rpc_pton(string, strlen(string),
1314                                         (struct sockaddr *)
1315                                         &mnt->mount_server.address,
1316                                         sizeof(mnt->mount_server.address));
1317                         kfree(string);
1318                         if (mnt->mount_server.addrlen == 0)
1319                                 goto out_invalid_address;
1320                         break;
1321                 case Opt_lookupcache:
1322                         string = match_strdup(args);
1323                         if (string == NULL)
1324                                 goto out_nomem;
1325                         token = match_token(string,
1326                                         nfs_lookupcache_tokens, args);
1327                         kfree(string);
1328                         switch (token) {
1329                                 case Opt_lookupcache_all:
1330                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1331                                         break;
1332                                 case Opt_lookupcache_positive:
1333                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1334                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1335                                         break;
1336                                 case Opt_lookupcache_none:
1337                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1338                                         break;
1339                                 default:
1340                                         dfprintk(MOUNT, "NFS:   invalid "
1341                                                         "lookupcache argument\n");
1342                                         return 0;
1343                         };
1344                         break;
1345
1346                 /*
1347                  * Special options
1348                  */
1349                 case Opt_sloppy:
1350                         sloppy = 1;
1351                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1352                         break;
1353                 case Opt_userspace:
1354                 case Opt_deprecated:
1355                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1356                                         "'%s'\n", p);
1357                         break;
1358
1359                 default:
1360                         invalid_option = 1;
1361                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1362                                         "'%s'\n", p);
1363                 }
1364         }
1365
1366         if (!sloppy && invalid_option)
1367                 return 0;
1368
1369         return 1;
1370
1371 out_invalid_address:
1372         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1373         return 0;
1374 out_invalid_value:
1375         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1376         return 0;
1377 out_nomem:
1378         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1379         return 0;
1380 out_security_failure:
1381         free_secdata(secdata);
1382         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1383         return 0;
1384 }
1385
1386 /*
1387  * Match the requested auth flavors with the list returned by
1388  * the server.  Returns zero and sets the mount's authentication
1389  * flavor on success; returns -EACCES if server does not support
1390  * the requested flavor.
1391  */
1392 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1393                              struct nfs_mount_request *request)
1394 {
1395         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1396
1397         /*
1398          * Certain releases of Linux's mountd return an empty
1399          * flavor list.  To prevent behavioral regression with
1400          * these servers (ie. rejecting mounts that used to
1401          * succeed), revert to pre-2.6.32 behavior (no checking)
1402          * if the returned flavor list is empty.
1403          */
1404         if (server_authlist_len == 0)
1405                 return 0;
1406
1407         /*
1408          * We avoid sophisticated negotiating here, as there are
1409          * plenty of cases where we can get it wrong, providing
1410          * either too little or too much security.
1411          *
1412          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1413          * flavor listed first.  However, some servers list
1414          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1415          * preferred default, in args->auth_flavors[0] if user
1416          * didn't specify sec= mount option.
1417          */
1418         for (i = 0; i < args->auth_flavor_len; i++)
1419                 for (j = 0; j < server_authlist_len; j++)
1420                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1421                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1422                                         request->auth_flavs[j]);
1423                                 args->auth_flavors[0] = request->auth_flavs[j];
1424                                 return 0;
1425                         }
1426
1427         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1428         nfs_umount(request);
1429         return -EACCES;
1430 }
1431
1432 /*
1433  * Use the remote server's MOUNT service to request the NFS file handle
1434  * corresponding to the provided path.
1435  */
1436 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1437                          struct nfs_fh *root_fh)
1438 {
1439         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1440         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1441         struct nfs_mount_request request = {
1442                 .sap            = (struct sockaddr *)
1443                                                 &args->mount_server.address,
1444                 .dirpath        = args->nfs_server.export_path,
1445                 .protocol       = args->mount_server.protocol,
1446                 .fh             = root_fh,
1447                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1448                 .auth_flav_len  = &server_authlist_len,
1449                 .auth_flavs     = server_authlist,
1450         };
1451         int status;
1452
1453         if (args->mount_server.version == 0) {
1454                 switch (args->version) {
1455                         default:
1456                                 args->mount_server.version = NFS_MNT3_VERSION;
1457                                 break;
1458                         case 2:
1459                                 args->mount_server.version = NFS_MNT_VERSION;
1460                 }
1461         }
1462         request.version = args->mount_server.version;
1463
1464         if (args->mount_server.hostname)
1465                 request.hostname = args->mount_server.hostname;
1466         else
1467                 request.hostname = args->nfs_server.hostname;
1468
1469         /*
1470          * Construct the mount server's address.
1471          */
1472         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1473                 memcpy(request.sap, &args->nfs_server.address,
1474                        args->nfs_server.addrlen);
1475                 args->mount_server.addrlen = args->nfs_server.addrlen;
1476         }
1477         request.salen = args->mount_server.addrlen;
1478         nfs_set_port(request.sap, &args->mount_server.port, 0);
1479
1480         /*
1481          * Now ask the mount server to map our export path
1482          * to a file handle.
1483          */
1484         status = nfs_mount(&request);
1485         if (status != 0) {
1486                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1487                                 request.hostname, status);
1488                 return status;
1489         }
1490
1491         /*
1492          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1493          */
1494         if (args->mount_server.version != NFS_MNT3_VERSION)
1495                 return 0;
1496         return nfs_walk_authlist(args, &request);
1497 }
1498
1499 static int nfs_parse_simple_hostname(const char *dev_name,
1500                                      char **hostname, size_t maxnamlen,
1501                                      char **export_path, size_t maxpathlen)
1502 {
1503         size_t len;
1504         char *colon, *comma;
1505
1506         colon = strchr(dev_name, ':');
1507         if (colon == NULL)
1508                 goto out_bad_devname;
1509
1510         len = colon - dev_name;
1511         if (len > maxnamlen)
1512                 goto out_hostname;
1513
1514         /* N.B. caller will free nfs_server.hostname in all cases */
1515         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1516         if (!*hostname)
1517                 goto out_nomem;
1518
1519         /* kill possible hostname list: not supported */
1520         comma = strchr(*hostname, ',');
1521         if (comma != NULL) {
1522                 if (comma == *hostname)
1523                         goto out_bad_devname;
1524                 *comma = '\0';
1525         }
1526
1527         colon++;
1528         len = strlen(colon);
1529         if (len > maxpathlen)
1530                 goto out_path;
1531         *export_path = kstrndup(colon, len, GFP_KERNEL);
1532         if (!*export_path)
1533                 goto out_nomem;
1534
1535         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1536         return 0;
1537
1538 out_bad_devname:
1539         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1540         return -EINVAL;
1541
1542 out_nomem:
1543         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1544         return -ENOMEM;
1545
1546 out_hostname:
1547         dfprintk(MOUNT, "NFS: server hostname too long\n");
1548         return -ENAMETOOLONG;
1549
1550 out_path:
1551         dfprintk(MOUNT, "NFS: export pathname too long\n");
1552         return -ENAMETOOLONG;
1553 }
1554
1555 /*
1556  * Hostname has square brackets around it because it contains one or
1557  * more colons.  We look for the first closing square bracket, and a
1558  * colon must follow it.
1559  */
1560 static int nfs_parse_protected_hostname(const char *dev_name,
1561                                         char **hostname, size_t maxnamlen,
1562                                         char **export_path, size_t maxpathlen)
1563 {
1564         size_t len;
1565         char *start, *end;
1566
1567         start = (char *)(dev_name + 1);
1568
1569         end = strchr(start, ']');
1570         if (end == NULL)
1571                 goto out_bad_devname;
1572         if (*(end + 1) != ':')
1573                 goto out_bad_devname;
1574
1575         len = end - start;
1576         if (len > maxnamlen)
1577                 goto out_hostname;
1578
1579         /* N.B. caller will free nfs_server.hostname in all cases */
1580         *hostname = kstrndup(start, len, GFP_KERNEL);
1581         if (*hostname == NULL)
1582                 goto out_nomem;
1583
1584         end += 2;
1585         len = strlen(end);
1586         if (len > maxpathlen)
1587                 goto out_path;
1588         *export_path = kstrndup(end, len, GFP_KERNEL);
1589         if (!*export_path)
1590                 goto out_nomem;
1591
1592         return 0;
1593
1594 out_bad_devname:
1595         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1596         return -EINVAL;
1597
1598 out_nomem:
1599         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1600         return -ENOMEM;
1601
1602 out_hostname:
1603         dfprintk(MOUNT, "NFS: server hostname too long\n");
1604         return -ENAMETOOLONG;
1605
1606 out_path:
1607         dfprintk(MOUNT, "NFS: export pathname too long\n");
1608         return -ENAMETOOLONG;
1609 }
1610
1611 /*
1612  * Split "dev_name" into "hostname:export_path".
1613  *
1614  * The leftmost colon demarks the split between the server's hostname
1615  * and the export path.  If the hostname starts with a left square
1616  * bracket, then it may contain colons.
1617  *
1618  * Note: caller frees hostname and export path, even on error.
1619  */
1620 static int nfs_parse_devname(const char *dev_name,
1621                              char **hostname, size_t maxnamlen,
1622                              char **export_path, size_t maxpathlen)
1623 {
1624         if (*dev_name == '[')
1625                 return nfs_parse_protected_hostname(dev_name,
1626                                                     hostname, maxnamlen,
1627                                                     export_path, maxpathlen);
1628
1629         return nfs_parse_simple_hostname(dev_name,
1630                                          hostname, maxnamlen,
1631                                          export_path, maxpathlen);
1632 }
1633
1634 /*
1635  * Validate the NFS2/NFS3 mount data
1636  * - fills in the mount root filehandle
1637  *
1638  * For option strings, user space handles the following behaviors:
1639  *
1640  * + DNS: mapping server host name to IP address ("addr=" option)
1641  *
1642  * + failure mode: how to behave if a mount request can't be handled
1643  *   immediately ("fg/bg" option)
1644  *
1645  * + retry: how often to retry a mount request ("retry=" option)
1646  *
1647  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1648  *   mountproto=tcp after mountproto=udp, and so on
1649  */
1650 static int nfs_validate_mount_data(void *options,
1651                                    struct nfs_parsed_mount_data *args,
1652                                    struct nfs_fh *mntfh,
1653                                    const char *dev_name)
1654 {
1655         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1656         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1657
1658         if (data == NULL)
1659                 goto out_no_data;
1660
1661         switch (data->version) {
1662         case 1:
1663                 data->namlen = 0;
1664         case 2:
1665                 data->bsize = 0;
1666         case 3:
1667                 if (data->flags & NFS_MOUNT_VER3)
1668                         goto out_no_v3;
1669                 data->root.size = NFS2_FHSIZE;
1670                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1671         case 4:
1672                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1673                         goto out_no_sec;
1674         case 5:
1675                 memset(data->context, 0, sizeof(data->context));
1676         case 6:
1677                 if (data->flags & NFS_MOUNT_VER3) {
1678                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1679                                 goto out_invalid_fh;
1680                         mntfh->size = data->root.size;
1681                         args->version = 3;
1682                 } else {
1683                         mntfh->size = NFS2_FHSIZE;
1684                         args->version = 2;
1685                 }
1686
1687
1688                 memcpy(mntfh->data, data->root.data, mntfh->size);
1689                 if (mntfh->size < sizeof(mntfh->data))
1690                         memset(mntfh->data + mntfh->size, 0,
1691                                sizeof(mntfh->data) - mntfh->size);
1692
1693                 /*
1694                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1695                  * can deal with.
1696                  */
1697                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1698                 args->rsize             = data->rsize;
1699                 args->wsize             = data->wsize;
1700                 args->timeo             = data->timeo;
1701                 args->retrans           = data->retrans;
1702                 args->acregmin          = data->acregmin;
1703                 args->acregmax          = data->acregmax;
1704                 args->acdirmin          = data->acdirmin;
1705                 args->acdirmax          = data->acdirmax;
1706
1707                 memcpy(sap, &data->addr, sizeof(data->addr));
1708                 args->nfs_server.addrlen = sizeof(data->addr);
1709                 if (!nfs_verify_server_address(sap))
1710                         goto out_no_address;
1711
1712                 if (!(data->flags & NFS_MOUNT_TCP))
1713                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1714                 /* N.B. caller will free nfs_server.hostname in all cases */
1715                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1716                 args->namlen            = data->namlen;
1717                 args->bsize             = data->bsize;
1718
1719                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1720                         args->auth_flavors[0] = data->pseudoflavor;
1721                 if (!args->nfs_server.hostname)
1722                         goto out_nomem;
1723
1724                 /*
1725                  * The legacy version 6 binary mount data from userspace has a
1726                  * field used only to transport selinux information into the
1727                  * the kernel.  To continue to support that functionality we
1728                  * have a touch of selinux knowledge here in the NFS code. The
1729                  * userspace code converted context=blah to just blah so we are
1730                  * converting back to the full string selinux understands.
1731                  */
1732                 if (data->context[0]){
1733 #ifdef CONFIG_SECURITY_SELINUX
1734                         int rc;
1735                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1736                         if (!opts_str)
1737                                 return -ENOMEM;
1738                         strcpy(opts_str, "context=");
1739                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1740                         strcat(opts_str, &data->context[0]);
1741                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1742                         kfree(opts_str);
1743                         if (rc)
1744                                 return rc;
1745 #else
1746                         return -EINVAL;
1747 #endif
1748                 }
1749
1750                 break;
1751         default: {
1752                 int status;
1753
1754                 if (nfs_parse_mount_options((char *)options, args) == 0)
1755                         return -EINVAL;
1756
1757                 if (!nfs_verify_server_address(sap))
1758                         goto out_no_address;
1759
1760                 if (args->version == 4)
1761 #ifdef CONFIG_NFS_V4
1762                         return nfs4_validate_text_mount_data(options,
1763                                                              args, dev_name);
1764 #else
1765                         goto out_v4_not_compiled;
1766 #endif
1767
1768                 nfs_set_port(sap, &args->nfs_server.port, 0);
1769
1770                 nfs_set_mount_transport_protocol(args);
1771
1772                 status = nfs_parse_devname(dev_name,
1773                                            &args->nfs_server.hostname,
1774                                            PAGE_SIZE,
1775                                            &args->nfs_server.export_path,
1776                                            NFS_MAXPATHLEN);
1777                 if (!status)
1778                         status = nfs_try_mount(args, mntfh);
1779
1780                 kfree(args->nfs_server.export_path);
1781                 args->nfs_server.export_path = NULL;
1782
1783                 if (status)
1784                         return status;
1785
1786                 break;
1787                 }
1788         }
1789
1790 #ifndef CONFIG_NFS_V3
1791         if (args->version == 3)
1792                 goto out_v3_not_compiled;
1793 #endif /* !CONFIG_NFS_V3 */
1794
1795         return 0;
1796
1797 out_no_data:
1798         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1799         return -EINVAL;
1800
1801 out_no_v3:
1802         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1803                  data->version);
1804         return -EINVAL;
1805
1806 out_no_sec:
1807         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1808         return -EINVAL;
1809
1810 #ifndef CONFIG_NFS_V3
1811 out_v3_not_compiled:
1812         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1813         return -EPROTONOSUPPORT;
1814 #endif /* !CONFIG_NFS_V3 */
1815
1816 #ifndef CONFIG_NFS_V4
1817 out_v4_not_compiled:
1818         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1819         return -EPROTONOSUPPORT;
1820 #endif /* !CONFIG_NFS_V4 */
1821
1822 out_nomem:
1823         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1824         return -ENOMEM;
1825
1826 out_no_address:
1827         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1828         return -EINVAL;
1829
1830 out_invalid_fh:
1831         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1832         return -EINVAL;
1833 }
1834
1835 static int
1836 nfs_compare_remount_data(struct nfs_server *nfss,
1837                          struct nfs_parsed_mount_data *data)
1838 {
1839         if (data->flags != nfss->flags ||
1840             data->rsize != nfss->rsize ||
1841             data->wsize != nfss->wsize ||
1842             data->retrans != nfss->client->cl_timeout->to_retries ||
1843             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1844             data->acregmin != nfss->acregmin / HZ ||
1845             data->acregmax != nfss->acregmax / HZ ||
1846             data->acdirmin != nfss->acdirmin / HZ ||
1847             data->acdirmax != nfss->acdirmax / HZ ||
1848             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1849             data->nfs_server.port != nfss->port ||
1850             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1851             !rpc_cmp_addr(&data->nfs_server.address,
1852                     &nfss->nfs_client->cl_addr))
1853                 return -EINVAL;
1854
1855         return 0;
1856 }
1857
1858 static int
1859 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1860 {
1861         int error;
1862         struct nfs_server *nfss = sb->s_fs_info;
1863         struct nfs_parsed_mount_data *data;
1864         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1865         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1866         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1867
1868         /*
1869          * Userspace mount programs that send binary options generally send
1870          * them populated with default values. We have no way to know which
1871          * ones were explicitly specified. Fall back to legacy behavior and
1872          * just return success.
1873          */
1874         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1875             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1876                                            options->version <= 6))))
1877                 return 0;
1878
1879         data = kzalloc(sizeof(*data), GFP_KERNEL);
1880         if (data == NULL)
1881                 return -ENOMEM;
1882
1883         lock_kernel();
1884         /* fill out struct with values from existing mount */
1885         data->flags = nfss->flags;
1886         data->rsize = nfss->rsize;
1887         data->wsize = nfss->wsize;
1888         data->retrans = nfss->client->cl_timeout->to_retries;
1889         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1890         data->acregmin = nfss->acregmin / HZ;
1891         data->acregmax = nfss->acregmax / HZ;
1892         data->acdirmin = nfss->acdirmin / HZ;
1893         data->acdirmax = nfss->acdirmax / HZ;
1894         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1895         data->nfs_server.port = nfss->port;
1896         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1897         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1898                 data->nfs_server.addrlen);
1899
1900         /* overwrite those values with any that were specified */
1901         error = nfs_parse_mount_options((char *)options, data);
1902         if (error < 0)
1903                 goto out;
1904
1905         /* compare new mount options with old ones */
1906         error = nfs_compare_remount_data(nfss, data);
1907 out:
1908         kfree(data);
1909         unlock_kernel();
1910         return error;
1911 }
1912
1913 /*
1914  * Initialise the common bits of the superblock
1915  */
1916 static inline void nfs_initialise_sb(struct super_block *sb)
1917 {
1918         struct nfs_server *server = NFS_SB(sb);
1919
1920         sb->s_magic = NFS_SUPER_MAGIC;
1921
1922         /* We probably want something more informative here */
1923         snprintf(sb->s_id, sizeof(sb->s_id),
1924                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1925
1926         if (sb->s_blocksize == 0)
1927                 sb->s_blocksize = nfs_block_bits(server->wsize,
1928                                                  &sb->s_blocksize_bits);
1929
1930         if (server->flags & NFS_MOUNT_NOAC)
1931                 sb->s_flags |= MS_SYNCHRONOUS;
1932
1933         sb->s_bdi = &server->backing_dev_info;
1934
1935         nfs_super_set_maxbytes(sb, server->maxfilesize);
1936 }
1937
1938 /*
1939  * Finish setting up an NFS2/3 superblock
1940  */
1941 static void nfs_fill_super(struct super_block *sb,
1942                            struct nfs_parsed_mount_data *data)
1943 {
1944         struct nfs_server *server = NFS_SB(sb);
1945
1946         sb->s_blocksize_bits = 0;
1947         sb->s_blocksize = 0;
1948         if (data->bsize)
1949                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1950
1951         if (server->nfs_client->rpc_ops->version == 3) {
1952                 /* The VFS shouldn't apply the umask to mode bits. We will do
1953                  * so ourselves when necessary.
1954                  */
1955                 sb->s_flags |= MS_POSIXACL;
1956                 sb->s_time_gran = 1;
1957         }
1958
1959         sb->s_op = &nfs_sops;
1960         nfs_initialise_sb(sb);
1961 }
1962
1963 /*
1964  * Finish setting up a cloned NFS2/3 superblock
1965  */
1966 static void nfs_clone_super(struct super_block *sb,
1967                             const struct super_block *old_sb)
1968 {
1969         struct nfs_server *server = NFS_SB(sb);
1970
1971         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1972         sb->s_blocksize = old_sb->s_blocksize;
1973         sb->s_maxbytes = old_sb->s_maxbytes;
1974
1975         if (server->nfs_client->rpc_ops->version == 3) {
1976                 /* The VFS shouldn't apply the umask to mode bits. We will do
1977                  * so ourselves when necessary.
1978                  */
1979                 sb->s_flags |= MS_POSIXACL;
1980                 sb->s_time_gran = 1;
1981         }
1982
1983         sb->s_op = old_sb->s_op;
1984         nfs_initialise_sb(sb);
1985 }
1986
1987 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1988 {
1989         const struct nfs_server *a = s->s_fs_info;
1990         const struct rpc_clnt *clnt_a = a->client;
1991         const struct rpc_clnt *clnt_b = b->client;
1992
1993         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1994                 goto Ebusy;
1995         if (a->nfs_client != b->nfs_client)
1996                 goto Ebusy;
1997         if (a->flags != b->flags)
1998                 goto Ebusy;
1999         if (a->wsize != b->wsize)
2000                 goto Ebusy;
2001         if (a->rsize != b->rsize)
2002                 goto Ebusy;
2003         if (a->acregmin != b->acregmin)
2004                 goto Ebusy;
2005         if (a->acregmax != b->acregmax)
2006                 goto Ebusy;
2007         if (a->acdirmin != b->acdirmin)
2008                 goto Ebusy;
2009         if (a->acdirmax != b->acdirmax)
2010                 goto Ebusy;
2011         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2012                 goto Ebusy;
2013         return 1;
2014 Ebusy:
2015         return 0;
2016 }
2017
2018 struct nfs_sb_mountdata {
2019         struct nfs_server *server;
2020         int mntflags;
2021 };
2022
2023 static int nfs_set_super(struct super_block *s, void *data)
2024 {
2025         struct nfs_sb_mountdata *sb_mntdata = data;
2026         struct nfs_server *server = sb_mntdata->server;
2027         int ret;
2028
2029         s->s_flags = sb_mntdata->mntflags;
2030         s->s_fs_info = server;
2031         ret = set_anon_super(s, server);
2032         if (ret == 0)
2033                 server->s_dev = s->s_dev;
2034         return ret;
2035 }
2036
2037 static int nfs_compare_super_address(struct nfs_server *server1,
2038                                      struct nfs_server *server2)
2039 {
2040         struct sockaddr *sap1, *sap2;
2041
2042         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2043         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2044
2045         if (sap1->sa_family != sap2->sa_family)
2046                 return 0;
2047
2048         switch (sap1->sa_family) {
2049         case AF_INET: {
2050                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2051                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2052                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2053                         return 0;
2054                 if (sin1->sin_port != sin2->sin_port)
2055                         return 0;
2056                 break;
2057         }
2058         case AF_INET6: {
2059                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2060                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2061                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2062                         return 0;
2063                 if (sin1->sin6_port != sin2->sin6_port)
2064                         return 0;
2065                 break;
2066         }
2067         default:
2068                 return 0;
2069         }
2070
2071         return 1;
2072 }
2073
2074 static int nfs_compare_super(struct super_block *sb, void *data)
2075 {
2076         struct nfs_sb_mountdata *sb_mntdata = data;
2077         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2078         int mntflags = sb_mntdata->mntflags;
2079
2080         if (!nfs_compare_super_address(old, server))
2081                 return 0;
2082         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2083         if (old->flags & NFS_MOUNT_UNSHARED)
2084                 return 0;
2085         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2086                 return 0;
2087         return nfs_compare_mount_options(sb, server, mntflags);
2088 }
2089
2090 static int nfs_bdi_register(struct nfs_server *server)
2091 {
2092         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2093 }
2094
2095 static int nfs_get_sb(struct file_system_type *fs_type,
2096         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2097 {
2098         struct nfs_server *server = NULL;
2099         struct super_block *s;
2100         struct nfs_parsed_mount_data *data;
2101         struct nfs_fh *mntfh;
2102         struct dentry *mntroot;
2103         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2104         struct nfs_sb_mountdata sb_mntdata = {
2105                 .mntflags = flags,
2106         };
2107         int error = -ENOMEM;
2108
2109         data = nfs_alloc_parsed_mount_data(3);
2110         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2111         if (data == NULL || mntfh == NULL)
2112                 goto out_free_fh;
2113
2114         security_init_mnt_opts(&data->lsm_opts);
2115
2116         /* Validate the mount data */
2117         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2118         if (error < 0)
2119                 goto out;
2120
2121 #ifdef CONFIG_NFS_V4
2122         if (data->version == 4) {
2123                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2124                 kfree(data->client_address);
2125                 goto out;
2126         }
2127 #endif  /* CONFIG_NFS_V4 */
2128
2129         /* Get a volume representation */
2130         server = nfs_create_server(data, mntfh);
2131         if (IS_ERR(server)) {
2132                 error = PTR_ERR(server);
2133                 goto out;
2134         }
2135         sb_mntdata.server = server;
2136
2137         if (server->flags & NFS_MOUNT_UNSHARED)
2138                 compare_super = NULL;
2139
2140         /* Get a superblock - note that we may end up sharing one that already exists */
2141         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2142         if (IS_ERR(s)) {
2143                 error = PTR_ERR(s);
2144                 goto out_err_nosb;
2145         }
2146
2147         if (s->s_fs_info != server) {
2148                 nfs_free_server(server);
2149                 server = NULL;
2150         } else {
2151                 error = nfs_bdi_register(server);
2152                 if (error)
2153                         goto error_splat_super;
2154         }
2155
2156         if (!s->s_root) {
2157                 /* initial superblock/root creation */
2158                 nfs_fill_super(s, data);
2159                 nfs_fscache_get_super_cookie(
2160                         s, data ? data->fscache_uniq : NULL, NULL);
2161         }
2162
2163         mntroot = nfs_get_root(s, mntfh);
2164         if (IS_ERR(mntroot)) {
2165                 error = PTR_ERR(mntroot);
2166                 goto error_splat_super;
2167         }
2168
2169         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2170         if (error)
2171                 goto error_splat_root;
2172
2173         s->s_flags |= MS_ACTIVE;
2174         mnt->mnt_sb = s;
2175         mnt->mnt_root = mntroot;
2176         error = 0;
2177
2178 out:
2179         kfree(data->nfs_server.hostname);
2180         kfree(data->mount_server.hostname);
2181         kfree(data->fscache_uniq);
2182         security_free_mnt_opts(&data->lsm_opts);
2183 out_free_fh:
2184         kfree(mntfh);
2185         kfree(data);
2186         return error;
2187
2188 out_err_nosb:
2189         nfs_free_server(server);
2190         goto out;
2191
2192 error_splat_root:
2193         dput(mntroot);
2194 error_splat_super:
2195         deactivate_locked_super(s);
2196         goto out;
2197 }
2198
2199 /*
2200  * Destroy an NFS2/3 superblock
2201  */
2202 static void nfs_kill_super(struct super_block *s)
2203 {
2204         struct nfs_server *server = NFS_SB(s);
2205
2206         kill_anon_super(s);
2207         bdi_unregister(&server->backing_dev_info);
2208         nfs_fscache_release_super_cookie(s);
2209         nfs_free_server(server);
2210 }
2211
2212 /*
2213  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2214  */
2215 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2216                            const char *dev_name, void *raw_data,
2217                            struct vfsmount *mnt)
2218 {
2219         struct nfs_clone_mount *data = raw_data;
2220         struct super_block *s;
2221         struct nfs_server *server;
2222         struct dentry *mntroot;
2223         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2224         struct nfs_sb_mountdata sb_mntdata = {
2225                 .mntflags = flags,
2226         };
2227         int error;
2228
2229         dprintk("--> nfs_xdev_get_sb()\n");
2230
2231         /* create a new volume representation */
2232         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2233         if (IS_ERR(server)) {
2234                 error = PTR_ERR(server);
2235                 goto out_err_noserver;
2236         }
2237         sb_mntdata.server = server;
2238
2239         if (server->flags & NFS_MOUNT_UNSHARED)
2240                 compare_super = NULL;
2241
2242         /* Get a superblock - note that we may end up sharing one that already exists */
2243         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2244         if (IS_ERR(s)) {
2245                 error = PTR_ERR(s);
2246                 goto out_err_nosb;
2247         }
2248
2249         if (s->s_fs_info != server) {
2250                 nfs_free_server(server);
2251                 server = NULL;
2252         } else {
2253                 error = nfs_bdi_register(server);
2254                 if (error)
2255                         goto error_splat_super;
2256         }
2257
2258         if (!s->s_root) {
2259                 /* initial superblock/root creation */
2260                 nfs_clone_super(s, data->sb);
2261                 nfs_fscache_get_super_cookie(s, NULL, data);
2262         }
2263
2264         mntroot = nfs_get_root(s, data->fh);
2265         if (IS_ERR(mntroot)) {
2266                 error = PTR_ERR(mntroot);
2267                 goto error_splat_super;
2268         }
2269         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2270                 dput(mntroot);
2271                 error = -ESTALE;
2272                 goto error_splat_super;
2273         }
2274
2275         s->s_flags |= MS_ACTIVE;
2276         mnt->mnt_sb = s;
2277         mnt->mnt_root = mntroot;
2278
2279         /* clone any lsm security options from the parent to the new sb */
2280         security_sb_clone_mnt_opts(data->sb, s);
2281
2282         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2283         return 0;
2284
2285 out_err_nosb:
2286         nfs_free_server(server);
2287 out_err_noserver:
2288         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2289         return error;
2290
2291 error_splat_super:
2292         deactivate_locked_super(s);
2293         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2294         return error;
2295 }
2296
2297 #ifdef CONFIG_NFS_V4
2298
2299 /*
2300  * Finish setting up a cloned NFS4 superblock
2301  */
2302 static void nfs4_clone_super(struct super_block *sb,
2303                             const struct super_block *old_sb)
2304 {
2305         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2306         sb->s_blocksize = old_sb->s_blocksize;
2307         sb->s_maxbytes = old_sb->s_maxbytes;
2308         sb->s_time_gran = 1;
2309         sb->s_op = old_sb->s_op;
2310         nfs_initialise_sb(sb);
2311 }
2312
2313 /*
2314  * Set up an NFS4 superblock
2315  */
2316 static void nfs4_fill_super(struct super_block *sb)
2317 {
2318         sb->s_time_gran = 1;
2319         sb->s_op = &nfs4_sops;
2320         nfs_initialise_sb(sb);
2321 }
2322
2323 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2324 {
2325         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2326 }
2327
2328 static int nfs4_validate_text_mount_data(void *options,
2329                                          struct nfs_parsed_mount_data *args,
2330                                          const char *dev_name)
2331 {
2332         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2333
2334         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2335
2336         nfs_validate_transport_protocol(args);
2337
2338         nfs4_validate_mount_flags(args);
2339
2340         if (args->version != 4) {
2341                 dfprintk(MOUNT,
2342                          "NFS4: Illegal mount version\n");
2343                 return -EINVAL;
2344         }
2345
2346         if (args->auth_flavor_len > 1) {
2347                 dfprintk(MOUNT,
2348                          "NFS4: Too many RPC auth flavours specified\n");
2349                 return -EINVAL;
2350         }
2351
2352         if (args->client_address == NULL) {
2353                 dfprintk(MOUNT,
2354                          "NFS4: mount program didn't pass callback address\n");
2355                 return -EINVAL;
2356         }
2357
2358         return nfs_parse_devname(dev_name,
2359                                    &args->nfs_server.hostname,
2360                                    NFS4_MAXNAMLEN,
2361                                    &args->nfs_server.export_path,
2362                                    NFS4_MAXPATHLEN);
2363 }
2364
2365 /*
2366  * Validate NFSv4 mount options
2367  */
2368 static int nfs4_validate_mount_data(void *options,
2369                                     struct nfs_parsed_mount_data *args,
2370                                     const char *dev_name)
2371 {
2372         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2373         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2374         char *c;
2375
2376         if (data == NULL)
2377                 goto out_no_data;
2378
2379         switch (data->version) {
2380         case 1:
2381                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2382                         goto out_no_address;
2383                 if (data->host_addrlen == 0)
2384                         goto out_no_address;
2385                 args->nfs_server.addrlen = data->host_addrlen;
2386                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2387                         return -EFAULT;
2388                 if (!nfs_verify_server_address(sap))
2389                         goto out_no_address;
2390
2391                 if (data->auth_flavourlen) {
2392                         if (data->auth_flavourlen > 1)
2393                                 goto out_inval_auth;
2394                         if (copy_from_user(&args->auth_flavors[0],
2395                                            data->auth_flavours,
2396                                            sizeof(args->auth_flavors[0])))
2397                                 return -EFAULT;
2398                 }
2399
2400                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2401                 if (IS_ERR(c))
2402                         return PTR_ERR(c);
2403                 args->nfs_server.hostname = c;
2404
2405                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2406                 if (IS_ERR(c))
2407                         return PTR_ERR(c);
2408                 args->nfs_server.export_path = c;
2409                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2410
2411                 c = strndup_user(data->client_addr.data, 16);
2412                 if (IS_ERR(c))
2413                         return PTR_ERR(c);
2414                 args->client_address = c;
2415
2416                 /*
2417                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2418                  * can deal with.
2419                  */
2420
2421                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2422                 args->rsize     = data->rsize;
2423                 args->wsize     = data->wsize;
2424                 args->timeo     = data->timeo;
2425                 args->retrans   = data->retrans;
2426                 args->acregmin  = data->acregmin;
2427                 args->acregmax  = data->acregmax;
2428                 args->acdirmin  = data->acdirmin;
2429                 args->acdirmax  = data->acdirmax;
2430                 args->nfs_server.protocol = data->proto;
2431                 nfs_validate_transport_protocol(args);
2432
2433                 break;
2434         default:
2435                 if (nfs_parse_mount_options((char *)options, args) == 0)
2436                         return -EINVAL;
2437
2438                 if (!nfs_verify_server_address(sap))
2439                         return -EINVAL;
2440
2441                 return nfs4_validate_text_mount_data(options, args, dev_name);
2442         }
2443
2444         return 0;
2445
2446 out_no_data:
2447         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2448         return -EINVAL;
2449
2450 out_inval_auth:
2451         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2452                  data->auth_flavourlen);
2453         return -EINVAL;
2454
2455 out_no_address:
2456         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2457         return -EINVAL;
2458 }
2459
2460 /*
2461  * Get the superblock for the NFS4 root partition
2462  */
2463 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2464         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2465 {
2466         struct nfs_parsed_mount_data *data = raw_data;
2467         struct super_block *s;
2468         struct nfs_server *server;
2469         struct nfs_fh *mntfh;
2470         struct dentry *mntroot;
2471         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2472         struct nfs_sb_mountdata sb_mntdata = {
2473                 .mntflags = flags,
2474         };
2475         int error = -ENOMEM;
2476
2477         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2478         if (data == NULL || mntfh == NULL)
2479                 goto out_free_fh;
2480
2481         security_init_mnt_opts(&data->lsm_opts);
2482
2483         /* Get a volume representation */
2484         server = nfs4_create_server(data, mntfh);
2485         if (IS_ERR(server)) {
2486                 error = PTR_ERR(server);
2487                 goto out;
2488         }
2489         sb_mntdata.server = server;
2490
2491         if (server->flags & NFS4_MOUNT_UNSHARED)
2492                 compare_super = NULL;
2493
2494         /* Get a superblock - note that we may end up sharing one that already exists */
2495         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2496         if (IS_ERR(s)) {
2497                 error = PTR_ERR(s);
2498                 goto out_free;
2499         }
2500
2501         if (s->s_fs_info != server) {
2502                 nfs_free_server(server);
2503                 server = NULL;
2504         } else {
2505                 error = nfs_bdi_register(server);
2506                 if (error)
2507                         goto error_splat_super;
2508         }
2509
2510         if (!s->s_root) {
2511                 /* initial superblock/root creation */
2512                 nfs4_fill_super(s);
2513                 nfs_fscache_get_super_cookie(
2514                         s, data ? data->fscache_uniq : NULL, NULL);
2515         }
2516
2517         mntroot = nfs4_get_root(s, mntfh);
2518         if (IS_ERR(mntroot)) {
2519                 error = PTR_ERR(mntroot);
2520                 goto error_splat_super;
2521         }
2522
2523         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2524         if (error)
2525                 goto error_splat_root;
2526
2527         s->s_flags |= MS_ACTIVE;
2528         mnt->mnt_sb = s;
2529         mnt->mnt_root = mntroot;
2530         error = 0;
2531
2532 out:
2533         security_free_mnt_opts(&data->lsm_opts);
2534 out_free_fh:
2535         kfree(mntfh);
2536         return error;
2537
2538 out_free:
2539         nfs_free_server(server);
2540         goto out;
2541
2542 error_splat_root:
2543         dput(mntroot);
2544 error_splat_super:
2545         deactivate_locked_super(s);
2546         goto out;
2547 }
2548
2549 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2550                 int flags, void *data, const char *hostname)
2551 {
2552         struct vfsmount *root_mnt;
2553         char *root_devname;
2554         size_t len;
2555
2556         len = strlen(hostname) + 3;
2557         root_devname = kmalloc(len, GFP_KERNEL);
2558         if (root_devname == NULL)
2559                 return ERR_PTR(-ENOMEM);
2560         snprintf(root_devname, len, "%s:/", hostname);
2561         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2562         kfree(root_devname);
2563         return root_mnt;
2564 }
2565
2566 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2567 {
2568         char *page = (char *) __get_free_page(GFP_KERNEL);
2569         char *devname, *tmp;
2570
2571         if (page == NULL)
2572                 return;
2573         devname = nfs_path(path->mnt->mnt_devname,
2574                         path->mnt->mnt_root, path->dentry,
2575                         page, PAGE_SIZE);
2576         if (devname == NULL)
2577                 goto out_freepage;
2578         tmp = kstrdup(devname, GFP_KERNEL);
2579         if (tmp == NULL)
2580                 goto out_freepage;
2581         kfree(mnt->mnt_devname);
2582         mnt->mnt_devname = tmp;
2583 out_freepage:
2584         free_page((unsigned long)page);
2585 }
2586
2587 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2588                 const char *export_path, struct vfsmount *mnt_target)
2589 {
2590         struct mnt_namespace *ns_private;
2591         struct nameidata nd;
2592         struct super_block *s;
2593         int ret;
2594
2595         ns_private = create_mnt_ns(root_mnt);
2596         ret = PTR_ERR(ns_private);
2597         if (IS_ERR(ns_private))
2598                 goto out_mntput;
2599
2600         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2601                         export_path, LOOKUP_FOLLOW, &nd);
2602
2603         put_mnt_ns(ns_private);
2604
2605         if (ret != 0)
2606                 goto out_err;
2607
2608         s = nd.path.mnt->mnt_sb;
2609         atomic_inc(&s->s_active);
2610         mnt_target->mnt_sb = s;
2611         mnt_target->mnt_root = dget(nd.path.dentry);
2612
2613         /* Correct the device pathname */
2614         nfs_fix_devname(&nd.path, mnt_target);
2615
2616         path_put(&nd.path);
2617         down_write(&s->s_umount);
2618         return 0;
2619 out_mntput:
2620         mntput(root_mnt);
2621 out_err:
2622         return ret;
2623 }
2624
2625 static int nfs4_try_mount(int flags, const char *dev_name,
2626                          struct nfs_parsed_mount_data *data,
2627                          struct vfsmount *mnt)
2628 {
2629         char *export_path;
2630         struct vfsmount *root_mnt;
2631         int error;
2632
2633         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2634
2635         export_path = data->nfs_server.export_path;
2636         data->nfs_server.export_path = "/";
2637         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2638                         data->nfs_server.hostname);
2639         data->nfs_server.export_path = export_path;
2640
2641         error = PTR_ERR(root_mnt);
2642         if (IS_ERR(root_mnt))
2643                 goto out;
2644
2645         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2646
2647 out:
2648         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2649                         error != 0 ? " [error]" : "");
2650         return error;
2651 }
2652
2653 /*
2654  * Get the superblock for an NFS4 mountpoint
2655  */
2656 static int nfs4_get_sb(struct file_system_type *fs_type,
2657         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2658 {
2659         struct nfs_parsed_mount_data *data;
2660         int error = -ENOMEM;
2661
2662         data = nfs_alloc_parsed_mount_data(4);
2663         if (data == NULL)
2664                 goto out_free_data;
2665
2666         /* Validate the mount data */
2667         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2668         if (error < 0)
2669                 goto out;
2670
2671         error = nfs4_try_mount(flags, dev_name, data, mnt);
2672
2673 out:
2674         kfree(data->client_address);
2675         kfree(data->nfs_server.export_path);
2676         kfree(data->nfs_server.hostname);
2677         kfree(data->fscache_uniq);
2678 out_free_data:
2679         kfree(data);
2680         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2681                         error != 0 ? " [error]" : "");
2682         return error;
2683 }
2684
2685 static void nfs4_kill_super(struct super_block *sb)
2686 {
2687         struct nfs_server *server = NFS_SB(sb);
2688
2689         dprintk("--> %s\n", __func__);
2690         nfs_super_return_all_delegations(sb);
2691         kill_anon_super(sb);
2692         nfs_fscache_release_super_cookie(sb);
2693         nfs_free_server(server);
2694         dprintk("<-- %s\n", __func__);
2695 }
2696
2697 /*
2698  * Clone an NFS4 server record on xdev traversal (FSID-change)
2699  */
2700 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2701                             const char *dev_name, void *raw_data,
2702                             struct vfsmount *mnt)
2703 {
2704         struct nfs_clone_mount *data = raw_data;
2705         struct super_block *s;
2706         struct nfs_server *server;
2707         struct dentry *mntroot;
2708         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2709         struct nfs_sb_mountdata sb_mntdata = {
2710                 .mntflags = flags,
2711         };
2712         int error;
2713
2714         dprintk("--> nfs4_xdev_get_sb()\n");
2715
2716         /* create a new volume representation */
2717         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2718         if (IS_ERR(server)) {
2719                 error = PTR_ERR(server);
2720                 goto out_err_noserver;
2721         }
2722         sb_mntdata.server = server;
2723
2724         if (server->flags & NFS4_MOUNT_UNSHARED)
2725                 compare_super = NULL;
2726
2727         /* Get a superblock - note that we may end up sharing one that already exists */
2728         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2729         if (IS_ERR(s)) {
2730                 error = PTR_ERR(s);
2731                 goto out_err_nosb;
2732         }
2733
2734         if (s->s_fs_info != server) {
2735                 nfs_free_server(server);
2736                 server = NULL;
2737         } else {
2738                 error = nfs_bdi_register(server);
2739                 if (error)
2740                         goto error_splat_super;
2741         }
2742
2743         if (!s->s_root) {
2744                 /* initial superblock/root creation */
2745                 nfs4_clone_super(s, data->sb);
2746                 nfs_fscache_get_super_cookie(s, NULL, data);
2747         }
2748
2749         mntroot = nfs4_get_root(s, data->fh);
2750         if (IS_ERR(mntroot)) {
2751                 error = PTR_ERR(mntroot);
2752                 goto error_splat_super;
2753         }
2754         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2755                 dput(mntroot);
2756                 error = -ESTALE;
2757                 goto error_splat_super;
2758         }
2759
2760         s->s_flags |= MS_ACTIVE;
2761         mnt->mnt_sb = s;
2762         mnt->mnt_root = mntroot;
2763
2764         security_sb_clone_mnt_opts(data->sb, s);
2765
2766         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2767         return 0;
2768
2769 out_err_nosb:
2770         nfs_free_server(server);
2771 out_err_noserver:
2772         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2773         return error;
2774
2775 error_splat_super:
2776         deactivate_locked_super(s);
2777         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2778         return error;
2779 }
2780
2781 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2782                 int flags, const char *dev_name, void *raw_data,
2783                 struct vfsmount *mnt)
2784 {
2785         struct nfs_clone_mount *data = raw_data;
2786         struct super_block *s;
2787         struct nfs_server *server;
2788         struct dentry *mntroot;
2789         struct nfs_fh mntfh;
2790         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2791         struct nfs_sb_mountdata sb_mntdata = {
2792                 .mntflags = flags,
2793         };
2794         int error;
2795
2796         dprintk("--> nfs4_referral_get_sb()\n");
2797
2798         /* create a new volume representation */
2799         server = nfs4_create_referral_server(data, &mntfh);
2800         if (IS_ERR(server)) {
2801                 error = PTR_ERR(server);
2802                 goto out_err_noserver;
2803         }
2804         sb_mntdata.server = server;
2805
2806         if (server->flags & NFS4_MOUNT_UNSHARED)
2807                 compare_super = NULL;
2808
2809         /* Get a superblock - note that we may end up sharing one that already exists */
2810         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2811         if (IS_ERR(s)) {
2812                 error = PTR_ERR(s);
2813                 goto out_err_nosb;
2814         }
2815
2816         if (s->s_fs_info != server) {
2817                 nfs_free_server(server);
2818                 server = NULL;
2819         } else {
2820                 error = nfs_bdi_register(server);
2821                 if (error)
2822                         goto error_splat_super;
2823         }
2824
2825         if (!s->s_root) {
2826                 /* initial superblock/root creation */
2827                 nfs4_fill_super(s);
2828                 nfs_fscache_get_super_cookie(s, NULL, data);
2829         }
2830
2831         mntroot = nfs4_get_root(s, &mntfh);
2832         if (IS_ERR(mntroot)) {
2833                 error = PTR_ERR(mntroot);
2834                 goto error_splat_super;
2835         }
2836         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2837                 dput(mntroot);
2838                 error = -ESTALE;
2839                 goto error_splat_super;
2840         }
2841
2842         s->s_flags |= MS_ACTIVE;
2843         mnt->mnt_sb = s;
2844         mnt->mnt_root = mntroot;
2845
2846         security_sb_clone_mnt_opts(data->sb, s);
2847
2848         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2849         return 0;
2850
2851 out_err_nosb:
2852         nfs_free_server(server);
2853 out_err_noserver:
2854         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2855         return error;
2856
2857 error_splat_super:
2858         deactivate_locked_super(s);
2859         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2860         return error;
2861 }
2862
2863 /*
2864  * Create an NFS4 server record on referral traversal
2865  */
2866 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2867                 int flags, const char *dev_name, void *raw_data,
2868                 struct vfsmount *mnt)
2869 {
2870         struct nfs_clone_mount *data = raw_data;
2871         char *export_path;
2872         struct vfsmount *root_mnt;
2873         int error;
2874
2875         dprintk("--> nfs4_referral_get_sb()\n");
2876
2877         export_path = data->mnt_path;
2878         data->mnt_path = "/";
2879
2880         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2881                         flags, data, data->hostname);
2882         data->mnt_path = export_path;
2883
2884         error = PTR_ERR(root_mnt);
2885         if (IS_ERR(root_mnt))
2886                 goto out;
2887
2888         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2889 out:
2890         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2891                         error != 0 ? " [error]" : "");
2892         return error;
2893 }
2894
2895 #endif /* CONFIG_NFS_V4 */