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                                 kfree(string);
1257                                 return 0;
1258                         }
1259                         break;
1260                 case Opt_mountproto:
1261                         string = match_strdup(args);
1262                         if (string == NULL)
1263                                 goto out_nomem;
1264                         token = match_token(string,
1265                                             nfs_xprt_protocol_tokens, args);
1266                         kfree(string);
1267
1268                         switch (token) {
1269                         case Opt_xprt_udp:
1270                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1271                                 break;
1272                         case Opt_xprt_tcp:
1273                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1274                                 break;
1275                         case Opt_xprt_rdma: /* not used for side protocols */
1276                         default:
1277                                 dfprintk(MOUNT, "NFS:   unrecognized "
1278                                                 "transport protocol\n");
1279                                 return 0;
1280                         }
1281                         break;
1282                 case Opt_addr:
1283                         string = match_strdup(args);
1284                         if (string == NULL)
1285                                 goto out_nomem;
1286                         mnt->nfs_server.addrlen =
1287                                 rpc_pton(string, strlen(string),
1288                                         (struct sockaddr *)
1289                                         &mnt->nfs_server.address,
1290                                         sizeof(mnt->nfs_server.address));
1291                         kfree(string);
1292                         if (mnt->nfs_server.addrlen == 0)
1293                                 goto out_invalid_address;
1294                         break;
1295                 case Opt_clientaddr:
1296                         string = match_strdup(args);
1297                         if (string == NULL)
1298                                 goto out_nomem;
1299                         kfree(mnt->client_address);
1300                         mnt->client_address = string;
1301                         break;
1302                 case Opt_mounthost:
1303                         string = match_strdup(args);
1304                         if (string == NULL)
1305                                 goto out_nomem;
1306                         kfree(mnt->mount_server.hostname);
1307                         mnt->mount_server.hostname = string;
1308                         break;
1309                 case Opt_mountaddr:
1310                         string = match_strdup(args);
1311                         if (string == NULL)
1312                                 goto out_nomem;
1313                         mnt->mount_server.addrlen =
1314                                 rpc_pton(string, strlen(string),
1315                                         (struct sockaddr *)
1316                                         &mnt->mount_server.address,
1317                                         sizeof(mnt->mount_server.address));
1318                         kfree(string);
1319                         if (mnt->mount_server.addrlen == 0)
1320                                 goto out_invalid_address;
1321                         break;
1322                 case Opt_lookupcache:
1323                         string = match_strdup(args);
1324                         if (string == NULL)
1325                                 goto out_nomem;
1326                         token = match_token(string,
1327                                         nfs_lookupcache_tokens, args);
1328                         kfree(string);
1329                         switch (token) {
1330                                 case Opt_lookupcache_all:
1331                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1332                                         break;
1333                                 case Opt_lookupcache_positive:
1334                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1335                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1336                                         break;
1337                                 case Opt_lookupcache_none:
1338                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1339                                         break;
1340                                 default:
1341                                         dfprintk(MOUNT, "NFS:   invalid "
1342                                                         "lookupcache argument\n");
1343                                         return 0;
1344                         };
1345                         break;
1346
1347                 /*
1348                  * Special options
1349                  */
1350                 case Opt_sloppy:
1351                         sloppy = 1;
1352                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1353                         break;
1354                 case Opt_userspace:
1355                 case Opt_deprecated:
1356                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1357                                         "'%s'\n", p);
1358                         break;
1359
1360                 default:
1361                         invalid_option = 1;
1362                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1363                                         "'%s'\n", p);
1364                 }
1365         }
1366
1367         if (!sloppy && invalid_option)
1368                 return 0;
1369
1370         return 1;
1371
1372 out_invalid_address:
1373         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1374         return 0;
1375 out_invalid_value:
1376         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1377         return 0;
1378 out_nomem:
1379         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1380         return 0;
1381 out_security_failure:
1382         free_secdata(secdata);
1383         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1384         return 0;
1385 }
1386
1387 /*
1388  * Match the requested auth flavors with the list returned by
1389  * the server.  Returns zero and sets the mount's authentication
1390  * flavor on success; returns -EACCES if server does not support
1391  * the requested flavor.
1392  */
1393 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1394                              struct nfs_mount_request *request)
1395 {
1396         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1397
1398         /*
1399          * Certain releases of Linux's mountd return an empty
1400          * flavor list.  To prevent behavioral regression with
1401          * these servers (ie. rejecting mounts that used to
1402          * succeed), revert to pre-2.6.32 behavior (no checking)
1403          * if the returned flavor list is empty.
1404          */
1405         if (server_authlist_len == 0)
1406                 return 0;
1407
1408         /*
1409          * We avoid sophisticated negotiating here, as there are
1410          * plenty of cases where we can get it wrong, providing
1411          * either too little or too much security.
1412          *
1413          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1414          * flavor listed first.  However, some servers list
1415          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1416          * preferred default, in args->auth_flavors[0] if user
1417          * didn't specify sec= mount option.
1418          */
1419         for (i = 0; i < args->auth_flavor_len; i++)
1420                 for (j = 0; j < server_authlist_len; j++)
1421                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1422                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1423                                         request->auth_flavs[j]);
1424                                 args->auth_flavors[0] = request->auth_flavs[j];
1425                                 return 0;
1426                         }
1427
1428         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1429         nfs_umount(request);
1430         return -EACCES;
1431 }
1432
1433 /*
1434  * Use the remote server's MOUNT service to request the NFS file handle
1435  * corresponding to the provided path.
1436  */
1437 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1438                          struct nfs_fh *root_fh)
1439 {
1440         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1441         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1442         struct nfs_mount_request request = {
1443                 .sap            = (struct sockaddr *)
1444                                                 &args->mount_server.address,
1445                 .dirpath        = args->nfs_server.export_path,
1446                 .protocol       = args->mount_server.protocol,
1447                 .fh             = root_fh,
1448                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1449                 .auth_flav_len  = &server_authlist_len,
1450                 .auth_flavs     = server_authlist,
1451         };
1452         int status;
1453
1454         if (args->mount_server.version == 0) {
1455                 switch (args->version) {
1456                         default:
1457                                 args->mount_server.version = NFS_MNT3_VERSION;
1458                                 break;
1459                         case 2:
1460                                 args->mount_server.version = NFS_MNT_VERSION;
1461                 }
1462         }
1463         request.version = args->mount_server.version;
1464
1465         if (args->mount_server.hostname)
1466                 request.hostname = args->mount_server.hostname;
1467         else
1468                 request.hostname = args->nfs_server.hostname;
1469
1470         /*
1471          * Construct the mount server's address.
1472          */
1473         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1474                 memcpy(request.sap, &args->nfs_server.address,
1475                        args->nfs_server.addrlen);
1476                 args->mount_server.addrlen = args->nfs_server.addrlen;
1477         }
1478         request.salen = args->mount_server.addrlen;
1479         nfs_set_port(request.sap, &args->mount_server.port, 0);
1480
1481         /*
1482          * Now ask the mount server to map our export path
1483          * to a file handle.
1484          */
1485         status = nfs_mount(&request);
1486         if (status != 0) {
1487                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1488                                 request.hostname, status);
1489                 return status;
1490         }
1491
1492         /*
1493          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1494          */
1495         if (args->mount_server.version != NFS_MNT3_VERSION)
1496                 return 0;
1497         return nfs_walk_authlist(args, &request);
1498 }
1499
1500 static int nfs_parse_simple_hostname(const char *dev_name,
1501                                      char **hostname, size_t maxnamlen,
1502                                      char **export_path, size_t maxpathlen)
1503 {
1504         size_t len;
1505         char *colon, *comma;
1506
1507         colon = strchr(dev_name, ':');
1508         if (colon == NULL)
1509                 goto out_bad_devname;
1510
1511         len = colon - dev_name;
1512         if (len > maxnamlen)
1513                 goto out_hostname;
1514
1515         /* N.B. caller will free nfs_server.hostname in all cases */
1516         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1517         if (!*hostname)
1518                 goto out_nomem;
1519
1520         /* kill possible hostname list: not supported */
1521         comma = strchr(*hostname, ',');
1522         if (comma != NULL) {
1523                 if (comma == *hostname)
1524                         goto out_bad_devname;
1525                 *comma = '\0';
1526         }
1527
1528         colon++;
1529         len = strlen(colon);
1530         if (len > maxpathlen)
1531                 goto out_path;
1532         *export_path = kstrndup(colon, len, GFP_KERNEL);
1533         if (!*export_path)
1534                 goto out_nomem;
1535
1536         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1537         return 0;
1538
1539 out_bad_devname:
1540         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1541         return -EINVAL;
1542
1543 out_nomem:
1544         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1545         return -ENOMEM;
1546
1547 out_hostname:
1548         dfprintk(MOUNT, "NFS: server hostname too long\n");
1549         return -ENAMETOOLONG;
1550
1551 out_path:
1552         dfprintk(MOUNT, "NFS: export pathname too long\n");
1553         return -ENAMETOOLONG;
1554 }
1555
1556 /*
1557  * Hostname has square brackets around it because it contains one or
1558  * more colons.  We look for the first closing square bracket, and a
1559  * colon must follow it.
1560  */
1561 static int nfs_parse_protected_hostname(const char *dev_name,
1562                                         char **hostname, size_t maxnamlen,
1563                                         char **export_path, size_t maxpathlen)
1564 {
1565         size_t len;
1566         char *start, *end;
1567
1568         start = (char *)(dev_name + 1);
1569
1570         end = strchr(start, ']');
1571         if (end == NULL)
1572                 goto out_bad_devname;
1573         if (*(end + 1) != ':')
1574                 goto out_bad_devname;
1575
1576         len = end - start;
1577         if (len > maxnamlen)
1578                 goto out_hostname;
1579
1580         /* N.B. caller will free nfs_server.hostname in all cases */
1581         *hostname = kstrndup(start, len, GFP_KERNEL);
1582         if (*hostname == NULL)
1583                 goto out_nomem;
1584
1585         end += 2;
1586         len = strlen(end);
1587         if (len > maxpathlen)
1588                 goto out_path;
1589         *export_path = kstrndup(end, len, GFP_KERNEL);
1590         if (!*export_path)
1591                 goto out_nomem;
1592
1593         return 0;
1594
1595 out_bad_devname:
1596         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1597         return -EINVAL;
1598
1599 out_nomem:
1600         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1601         return -ENOMEM;
1602
1603 out_hostname:
1604         dfprintk(MOUNT, "NFS: server hostname too long\n");
1605         return -ENAMETOOLONG;
1606
1607 out_path:
1608         dfprintk(MOUNT, "NFS: export pathname too long\n");
1609         return -ENAMETOOLONG;
1610 }
1611
1612 /*
1613  * Split "dev_name" into "hostname:export_path".
1614  *
1615  * The leftmost colon demarks the split between the server's hostname
1616  * and the export path.  If the hostname starts with a left square
1617  * bracket, then it may contain colons.
1618  *
1619  * Note: caller frees hostname and export path, even on error.
1620  */
1621 static int nfs_parse_devname(const char *dev_name,
1622                              char **hostname, size_t maxnamlen,
1623                              char **export_path, size_t maxpathlen)
1624 {
1625         if (*dev_name == '[')
1626                 return nfs_parse_protected_hostname(dev_name,
1627                                                     hostname, maxnamlen,
1628                                                     export_path, maxpathlen);
1629
1630         return nfs_parse_simple_hostname(dev_name,
1631                                          hostname, maxnamlen,
1632                                          export_path, maxpathlen);
1633 }
1634
1635 /*
1636  * Validate the NFS2/NFS3 mount data
1637  * - fills in the mount root filehandle
1638  *
1639  * For option strings, user space handles the following behaviors:
1640  *
1641  * + DNS: mapping server host name to IP address ("addr=" option)
1642  *
1643  * + failure mode: how to behave if a mount request can't be handled
1644  *   immediately ("fg/bg" option)
1645  *
1646  * + retry: how often to retry a mount request ("retry=" option)
1647  *
1648  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1649  *   mountproto=tcp after mountproto=udp, and so on
1650  */
1651 static int nfs_validate_mount_data(void *options,
1652                                    struct nfs_parsed_mount_data *args,
1653                                    struct nfs_fh *mntfh,
1654                                    const char *dev_name)
1655 {
1656         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1657         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1658
1659         if (data == NULL)
1660                 goto out_no_data;
1661
1662         switch (data->version) {
1663         case 1:
1664                 data->namlen = 0;
1665         case 2:
1666                 data->bsize = 0;
1667         case 3:
1668                 if (data->flags & NFS_MOUNT_VER3)
1669                         goto out_no_v3;
1670                 data->root.size = NFS2_FHSIZE;
1671                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1672         case 4:
1673                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1674                         goto out_no_sec;
1675         case 5:
1676                 memset(data->context, 0, sizeof(data->context));
1677         case 6:
1678                 if (data->flags & NFS_MOUNT_VER3) {
1679                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1680                                 goto out_invalid_fh;
1681                         mntfh->size = data->root.size;
1682                         args->version = 3;
1683                 } else {
1684                         mntfh->size = NFS2_FHSIZE;
1685                         args->version = 2;
1686                 }
1687
1688
1689                 memcpy(mntfh->data, data->root.data, mntfh->size);
1690                 if (mntfh->size < sizeof(mntfh->data))
1691                         memset(mntfh->data + mntfh->size, 0,
1692                                sizeof(mntfh->data) - mntfh->size);
1693
1694                 /*
1695                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1696                  * can deal with.
1697                  */
1698                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1699                 args->rsize             = data->rsize;
1700                 args->wsize             = data->wsize;
1701                 args->timeo             = data->timeo;
1702                 args->retrans           = data->retrans;
1703                 args->acregmin          = data->acregmin;
1704                 args->acregmax          = data->acregmax;
1705                 args->acdirmin          = data->acdirmin;
1706                 args->acdirmax          = data->acdirmax;
1707
1708                 memcpy(sap, &data->addr, sizeof(data->addr));
1709                 args->nfs_server.addrlen = sizeof(data->addr);
1710                 if (!nfs_verify_server_address(sap))
1711                         goto out_no_address;
1712
1713                 if (!(data->flags & NFS_MOUNT_TCP))
1714                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1715                 /* N.B. caller will free nfs_server.hostname in all cases */
1716                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1717                 args->namlen            = data->namlen;
1718                 args->bsize             = data->bsize;
1719
1720                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1721                         args->auth_flavors[0] = data->pseudoflavor;
1722                 if (!args->nfs_server.hostname)
1723                         goto out_nomem;
1724
1725                 /*
1726                  * The legacy version 6 binary mount data from userspace has a
1727                  * field used only to transport selinux information into the
1728                  * the kernel.  To continue to support that functionality we
1729                  * have a touch of selinux knowledge here in the NFS code. The
1730                  * userspace code converted context=blah to just blah so we are
1731                  * converting back to the full string selinux understands.
1732                  */
1733                 if (data->context[0]){
1734 #ifdef CONFIG_SECURITY_SELINUX
1735                         int rc;
1736                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1737                         if (!opts_str)
1738                                 return -ENOMEM;
1739                         strcpy(opts_str, "context=");
1740                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1741                         strcat(opts_str, &data->context[0]);
1742                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1743                         kfree(opts_str);
1744                         if (rc)
1745                                 return rc;
1746 #else
1747                         return -EINVAL;
1748 #endif
1749                 }
1750
1751                 break;
1752         default: {
1753                 int status;
1754
1755                 if (nfs_parse_mount_options((char *)options, args) == 0)
1756                         return -EINVAL;
1757
1758                 if (!nfs_verify_server_address(sap))
1759                         goto out_no_address;
1760
1761                 if (args->version == 4)
1762 #ifdef CONFIG_NFS_V4
1763                         return nfs4_validate_text_mount_data(options,
1764                                                              args, dev_name);
1765 #else
1766                         goto out_v4_not_compiled;
1767 #endif
1768
1769                 nfs_set_port(sap, &args->nfs_server.port, 0);
1770
1771                 nfs_set_mount_transport_protocol(args);
1772
1773                 status = nfs_parse_devname(dev_name,
1774                                            &args->nfs_server.hostname,
1775                                            PAGE_SIZE,
1776                                            &args->nfs_server.export_path,
1777                                            NFS_MAXPATHLEN);
1778                 if (!status)
1779                         status = nfs_try_mount(args, mntfh);
1780
1781                 kfree(args->nfs_server.export_path);
1782                 args->nfs_server.export_path = NULL;
1783
1784                 if (status)
1785                         return status;
1786
1787                 break;
1788                 }
1789         }
1790
1791 #ifndef CONFIG_NFS_V3
1792         if (args->version == 3)
1793                 goto out_v3_not_compiled;
1794 #endif /* !CONFIG_NFS_V3 */
1795
1796         return 0;
1797
1798 out_no_data:
1799         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1800         return -EINVAL;
1801
1802 out_no_v3:
1803         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1804                  data->version);
1805         return -EINVAL;
1806
1807 out_no_sec:
1808         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1809         return -EINVAL;
1810
1811 #ifndef CONFIG_NFS_V3
1812 out_v3_not_compiled:
1813         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1814         return -EPROTONOSUPPORT;
1815 #endif /* !CONFIG_NFS_V3 */
1816
1817 #ifndef CONFIG_NFS_V4
1818 out_v4_not_compiled:
1819         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1820         return -EPROTONOSUPPORT;
1821 #endif /* !CONFIG_NFS_V4 */
1822
1823 out_nomem:
1824         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1825         return -ENOMEM;
1826
1827 out_no_address:
1828         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1829         return -EINVAL;
1830
1831 out_invalid_fh:
1832         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1833         return -EINVAL;
1834 }
1835
1836 static int
1837 nfs_compare_remount_data(struct nfs_server *nfss,
1838                          struct nfs_parsed_mount_data *data)
1839 {
1840         if (data->flags != nfss->flags ||
1841             data->rsize != nfss->rsize ||
1842             data->wsize != nfss->wsize ||
1843             data->retrans != nfss->client->cl_timeout->to_retries ||
1844             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1845             data->acregmin != nfss->acregmin / HZ ||
1846             data->acregmax != nfss->acregmax / HZ ||
1847             data->acdirmin != nfss->acdirmin / HZ ||
1848             data->acdirmax != nfss->acdirmax / HZ ||
1849             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1850             data->nfs_server.port != nfss->port ||
1851             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1852             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1853                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
1854                 return -EINVAL;
1855
1856         return 0;
1857 }
1858
1859 static int
1860 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1861 {
1862         int error;
1863         struct nfs_server *nfss = sb->s_fs_info;
1864         struct nfs_parsed_mount_data *data;
1865         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1866         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1867         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1868
1869         /*
1870          * Userspace mount programs that send binary options generally send
1871          * them populated with default values. We have no way to know which
1872          * ones were explicitly specified. Fall back to legacy behavior and
1873          * just return success.
1874          */
1875         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1876             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1877                                            options->version <= 6))))
1878                 return 0;
1879
1880         data = kzalloc(sizeof(*data), GFP_KERNEL);
1881         if (data == NULL)
1882                 return -ENOMEM;
1883
1884         lock_kernel();
1885         /* fill out struct with values from existing mount */
1886         data->flags = nfss->flags;
1887         data->rsize = nfss->rsize;
1888         data->wsize = nfss->wsize;
1889         data->retrans = nfss->client->cl_timeout->to_retries;
1890         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1891         data->acregmin = nfss->acregmin / HZ;
1892         data->acregmax = nfss->acregmax / HZ;
1893         data->acdirmin = nfss->acdirmin / HZ;
1894         data->acdirmax = nfss->acdirmax / HZ;
1895         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1896         data->nfs_server.port = nfss->port;
1897         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1898         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1899                 data->nfs_server.addrlen);
1900
1901         /* overwrite those values with any that were specified */
1902         error = nfs_parse_mount_options((char *)options, data);
1903         if (error < 0)
1904                 goto out;
1905
1906         /* compare new mount options with old ones */
1907         error = nfs_compare_remount_data(nfss, data);
1908 out:
1909         kfree(data);
1910         unlock_kernel();
1911         return error;
1912 }
1913
1914 /*
1915  * Initialise the common bits of the superblock
1916  */
1917 static inline void nfs_initialise_sb(struct super_block *sb)
1918 {
1919         struct nfs_server *server = NFS_SB(sb);
1920
1921         sb->s_magic = NFS_SUPER_MAGIC;
1922
1923         /* We probably want something more informative here */
1924         snprintf(sb->s_id, sizeof(sb->s_id),
1925                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1926
1927         if (sb->s_blocksize == 0)
1928                 sb->s_blocksize = nfs_block_bits(server->wsize,
1929                                                  &sb->s_blocksize_bits);
1930
1931         if (server->flags & NFS_MOUNT_NOAC)
1932                 sb->s_flags |= MS_SYNCHRONOUS;
1933
1934         sb->s_bdi = &server->backing_dev_info;
1935
1936         nfs_super_set_maxbytes(sb, server->maxfilesize);
1937 }
1938
1939 /*
1940  * Finish setting up an NFS2/3 superblock
1941  */
1942 static void nfs_fill_super(struct super_block *sb,
1943                            struct nfs_parsed_mount_data *data)
1944 {
1945         struct nfs_server *server = NFS_SB(sb);
1946
1947         sb->s_blocksize_bits = 0;
1948         sb->s_blocksize = 0;
1949         if (data->bsize)
1950                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1951
1952         if (server->nfs_client->rpc_ops->version == 3) {
1953                 /* The VFS shouldn't apply the umask to mode bits. We will do
1954                  * so ourselves when necessary.
1955                  */
1956                 sb->s_flags |= MS_POSIXACL;
1957                 sb->s_time_gran = 1;
1958         }
1959
1960         sb->s_op = &nfs_sops;
1961         nfs_initialise_sb(sb);
1962 }
1963
1964 /*
1965  * Finish setting up a cloned NFS2/3 superblock
1966  */
1967 static void nfs_clone_super(struct super_block *sb,
1968                             const struct super_block *old_sb)
1969 {
1970         struct nfs_server *server = NFS_SB(sb);
1971
1972         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1973         sb->s_blocksize = old_sb->s_blocksize;
1974         sb->s_maxbytes = old_sb->s_maxbytes;
1975
1976         if (server->nfs_client->rpc_ops->version == 3) {
1977                 /* The VFS shouldn't apply the umask to mode bits. We will do
1978                  * so ourselves when necessary.
1979                  */
1980                 sb->s_flags |= MS_POSIXACL;
1981                 sb->s_time_gran = 1;
1982         }
1983
1984         sb->s_op = old_sb->s_op;
1985         nfs_initialise_sb(sb);
1986 }
1987
1988 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1989 {
1990         const struct nfs_server *a = s->s_fs_info;
1991         const struct rpc_clnt *clnt_a = a->client;
1992         const struct rpc_clnt *clnt_b = b->client;
1993
1994         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1995                 goto Ebusy;
1996         if (a->nfs_client != b->nfs_client)
1997                 goto Ebusy;
1998         if (a->flags != b->flags)
1999                 goto Ebusy;
2000         if (a->wsize != b->wsize)
2001                 goto Ebusy;
2002         if (a->rsize != b->rsize)
2003                 goto Ebusy;
2004         if (a->acregmin != b->acregmin)
2005                 goto Ebusy;
2006         if (a->acregmax != b->acregmax)
2007                 goto Ebusy;
2008         if (a->acdirmin != b->acdirmin)
2009                 goto Ebusy;
2010         if (a->acdirmax != b->acdirmax)
2011                 goto Ebusy;
2012         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2013                 goto Ebusy;
2014         return 1;
2015 Ebusy:
2016         return 0;
2017 }
2018
2019 struct nfs_sb_mountdata {
2020         struct nfs_server *server;
2021         int mntflags;
2022 };
2023
2024 static int nfs_set_super(struct super_block *s, void *data)
2025 {
2026         struct nfs_sb_mountdata *sb_mntdata = data;
2027         struct nfs_server *server = sb_mntdata->server;
2028         int ret;
2029
2030         s->s_flags = sb_mntdata->mntflags;
2031         s->s_fs_info = server;
2032         ret = set_anon_super(s, server);
2033         if (ret == 0)
2034                 server->s_dev = s->s_dev;
2035         return ret;
2036 }
2037
2038 static int nfs_compare_super_address(struct nfs_server *server1,
2039                                      struct nfs_server *server2)
2040 {
2041         struct sockaddr *sap1, *sap2;
2042
2043         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2044         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2045
2046         if (sap1->sa_family != sap2->sa_family)
2047                 return 0;
2048
2049         switch (sap1->sa_family) {
2050         case AF_INET: {
2051                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2052                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2053                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2054                         return 0;
2055                 if (sin1->sin_port != sin2->sin_port)
2056                         return 0;
2057                 break;
2058         }
2059         case AF_INET6: {
2060                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2061                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2062                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2063                         return 0;
2064                 if (sin1->sin6_port != sin2->sin6_port)
2065                         return 0;
2066                 break;
2067         }
2068         default:
2069                 return 0;
2070         }
2071
2072         return 1;
2073 }
2074
2075 static int nfs_compare_super(struct super_block *sb, void *data)
2076 {
2077         struct nfs_sb_mountdata *sb_mntdata = data;
2078         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2079         int mntflags = sb_mntdata->mntflags;
2080
2081         if (!nfs_compare_super_address(old, server))
2082                 return 0;
2083         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2084         if (old->flags & NFS_MOUNT_UNSHARED)
2085                 return 0;
2086         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2087                 return 0;
2088         return nfs_compare_mount_options(sb, server, mntflags);
2089 }
2090
2091 static int nfs_bdi_register(struct nfs_server *server)
2092 {
2093         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2094 }
2095
2096 static int nfs_get_sb(struct file_system_type *fs_type,
2097         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2098 {
2099         struct nfs_server *server = NULL;
2100         struct super_block *s;
2101         struct nfs_parsed_mount_data *data;
2102         struct nfs_fh *mntfh;
2103         struct dentry *mntroot;
2104         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2105         struct nfs_sb_mountdata sb_mntdata = {
2106                 .mntflags = flags,
2107         };
2108         int error = -ENOMEM;
2109
2110         data = nfs_alloc_parsed_mount_data(3);
2111         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2112         if (data == NULL || mntfh == NULL)
2113                 goto out_free_fh;
2114
2115         security_init_mnt_opts(&data->lsm_opts);
2116
2117         /* Validate the mount data */
2118         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2119         if (error < 0)
2120                 goto out;
2121
2122 #ifdef CONFIG_NFS_V4
2123         if (data->version == 4) {
2124                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2125                 kfree(data->client_address);
2126                 goto out;
2127         }
2128 #endif  /* CONFIG_NFS_V4 */
2129
2130         /* Get a volume representation */
2131         server = nfs_create_server(data, mntfh);
2132         if (IS_ERR(server)) {
2133                 error = PTR_ERR(server);
2134                 goto out;
2135         }
2136         sb_mntdata.server = server;
2137
2138         if (server->flags & NFS_MOUNT_UNSHARED)
2139                 compare_super = NULL;
2140
2141         /* Get a superblock - note that we may end up sharing one that already exists */
2142         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2143         if (IS_ERR(s)) {
2144                 error = PTR_ERR(s);
2145                 goto out_err_nosb;
2146         }
2147
2148         if (s->s_fs_info != server) {
2149                 nfs_free_server(server);
2150                 server = NULL;
2151         } else {
2152                 error = nfs_bdi_register(server);
2153                 if (error)
2154                         goto error_splat_super;
2155         }
2156
2157         if (!s->s_root) {
2158                 /* initial superblock/root creation */
2159                 nfs_fill_super(s, data);
2160                 nfs_fscache_get_super_cookie(
2161                         s, data ? data->fscache_uniq : NULL, NULL);
2162         }
2163
2164         mntroot = nfs_get_root(s, mntfh);
2165         if (IS_ERR(mntroot)) {
2166                 error = PTR_ERR(mntroot);
2167                 goto error_splat_super;
2168         }
2169
2170         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2171         if (error)
2172                 goto error_splat_root;
2173
2174         s->s_flags |= MS_ACTIVE;
2175         mnt->mnt_sb = s;
2176         mnt->mnt_root = mntroot;
2177         error = 0;
2178
2179 out:
2180         kfree(data->nfs_server.hostname);
2181         kfree(data->mount_server.hostname);
2182         kfree(data->fscache_uniq);
2183         security_free_mnt_opts(&data->lsm_opts);
2184 out_free_fh:
2185         kfree(mntfh);
2186         kfree(data);
2187         return error;
2188
2189 out_err_nosb:
2190         nfs_free_server(server);
2191         goto out;
2192
2193 error_splat_root:
2194         dput(mntroot);
2195 error_splat_super:
2196         deactivate_locked_super(s);
2197         goto out;
2198 }
2199
2200 /*
2201  * Destroy an NFS2/3 superblock
2202  */
2203 static void nfs_kill_super(struct super_block *s)
2204 {
2205         struct nfs_server *server = NFS_SB(s);
2206
2207         kill_anon_super(s);
2208         bdi_unregister(&server->backing_dev_info);
2209         nfs_fscache_release_super_cookie(s);
2210         nfs_free_server(server);
2211 }
2212
2213 /*
2214  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2215  */
2216 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2217                            const char *dev_name, void *raw_data,
2218                            struct vfsmount *mnt)
2219 {
2220         struct nfs_clone_mount *data = raw_data;
2221         struct super_block *s;
2222         struct nfs_server *server;
2223         struct dentry *mntroot;
2224         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2225         struct nfs_sb_mountdata sb_mntdata = {
2226                 .mntflags = flags,
2227         };
2228         int error;
2229
2230         dprintk("--> nfs_xdev_get_sb()\n");
2231
2232         /* create a new volume representation */
2233         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2234         if (IS_ERR(server)) {
2235                 error = PTR_ERR(server);
2236                 goto out_err_noserver;
2237         }
2238         sb_mntdata.server = server;
2239
2240         if (server->flags & NFS_MOUNT_UNSHARED)
2241                 compare_super = NULL;
2242
2243         /* Get a superblock - note that we may end up sharing one that already exists */
2244         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2245         if (IS_ERR(s)) {
2246                 error = PTR_ERR(s);
2247                 goto out_err_nosb;
2248         }
2249
2250         if (s->s_fs_info != server) {
2251                 nfs_free_server(server);
2252                 server = NULL;
2253         } else {
2254                 error = nfs_bdi_register(server);
2255                 if (error)
2256                         goto error_splat_super;
2257         }
2258
2259         if (!s->s_root) {
2260                 /* initial superblock/root creation */
2261                 nfs_clone_super(s, data->sb);
2262                 nfs_fscache_get_super_cookie(s, NULL, data);
2263         }
2264
2265         mntroot = nfs_get_root(s, data->fh);
2266         if (IS_ERR(mntroot)) {
2267                 error = PTR_ERR(mntroot);
2268                 goto error_splat_super;
2269         }
2270         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2271                 dput(mntroot);
2272                 error = -ESTALE;
2273                 goto error_splat_super;
2274         }
2275
2276         s->s_flags |= MS_ACTIVE;
2277         mnt->mnt_sb = s;
2278         mnt->mnt_root = mntroot;
2279
2280         /* clone any lsm security options from the parent to the new sb */
2281         security_sb_clone_mnt_opts(data->sb, s);
2282
2283         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2284         return 0;
2285
2286 out_err_nosb:
2287         nfs_free_server(server);
2288 out_err_noserver:
2289         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2290         return error;
2291
2292 error_splat_super:
2293         deactivate_locked_super(s);
2294         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2295         return error;
2296 }
2297
2298 #ifdef CONFIG_NFS_V4
2299
2300 /*
2301  * Finish setting up a cloned NFS4 superblock
2302  */
2303 static void nfs4_clone_super(struct super_block *sb,
2304                             const struct super_block *old_sb)
2305 {
2306         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2307         sb->s_blocksize = old_sb->s_blocksize;
2308         sb->s_maxbytes = old_sb->s_maxbytes;
2309         sb->s_time_gran = 1;
2310         sb->s_op = old_sb->s_op;
2311         nfs_initialise_sb(sb);
2312 }
2313
2314 /*
2315  * Set up an NFS4 superblock
2316  */
2317 static void nfs4_fill_super(struct super_block *sb)
2318 {
2319         sb->s_time_gran = 1;
2320         sb->s_op = &nfs4_sops;
2321         nfs_initialise_sb(sb);
2322 }
2323
2324 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2325 {
2326         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2327 }
2328
2329 static int nfs4_validate_text_mount_data(void *options,
2330                                          struct nfs_parsed_mount_data *args,
2331                                          const char *dev_name)
2332 {
2333         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2334
2335         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2336
2337         nfs_validate_transport_protocol(args);
2338
2339         nfs4_validate_mount_flags(args);
2340
2341         if (args->version != 4) {
2342                 dfprintk(MOUNT,
2343                          "NFS4: Illegal mount version\n");
2344                 return -EINVAL;
2345         }
2346
2347         if (args->auth_flavor_len > 1) {
2348                 dfprintk(MOUNT,
2349                          "NFS4: Too many RPC auth flavours specified\n");
2350                 return -EINVAL;
2351         }
2352
2353         if (args->client_address == NULL) {
2354                 dfprintk(MOUNT,
2355                          "NFS4: mount program didn't pass callback address\n");
2356                 return -EINVAL;
2357         }
2358
2359         return nfs_parse_devname(dev_name,
2360                                    &args->nfs_server.hostname,
2361                                    NFS4_MAXNAMLEN,
2362                                    &args->nfs_server.export_path,
2363                                    NFS4_MAXPATHLEN);
2364 }
2365
2366 /*
2367  * Validate NFSv4 mount options
2368  */
2369 static int nfs4_validate_mount_data(void *options,
2370                                     struct nfs_parsed_mount_data *args,
2371                                     const char *dev_name)
2372 {
2373         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2374         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2375         char *c;
2376
2377         if (data == NULL)
2378                 goto out_no_data;
2379
2380         switch (data->version) {
2381         case 1:
2382                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2383                         goto out_no_address;
2384                 if (data->host_addrlen == 0)
2385                         goto out_no_address;
2386                 args->nfs_server.addrlen = data->host_addrlen;
2387                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2388                         return -EFAULT;
2389                 if (!nfs_verify_server_address(sap))
2390                         goto out_no_address;
2391
2392                 if (data->auth_flavourlen) {
2393                         if (data->auth_flavourlen > 1)
2394                                 goto out_inval_auth;
2395                         if (copy_from_user(&args->auth_flavors[0],
2396                                            data->auth_flavours,
2397                                            sizeof(args->auth_flavors[0])))
2398                                 return -EFAULT;
2399                 }
2400
2401                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2402                 if (IS_ERR(c))
2403                         return PTR_ERR(c);
2404                 args->nfs_server.hostname = c;
2405
2406                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2407                 if (IS_ERR(c))
2408                         return PTR_ERR(c);
2409                 args->nfs_server.export_path = c;
2410                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2411
2412                 c = strndup_user(data->client_addr.data, 16);
2413                 if (IS_ERR(c))
2414                         return PTR_ERR(c);
2415                 args->client_address = c;
2416
2417                 /*
2418                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2419                  * can deal with.
2420                  */
2421
2422                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2423                 args->rsize     = data->rsize;
2424                 args->wsize     = data->wsize;
2425                 args->timeo     = data->timeo;
2426                 args->retrans   = data->retrans;
2427                 args->acregmin  = data->acregmin;
2428                 args->acregmax  = data->acregmax;
2429                 args->acdirmin  = data->acdirmin;
2430                 args->acdirmax  = data->acdirmax;
2431                 args->nfs_server.protocol = data->proto;
2432                 nfs_validate_transport_protocol(args);
2433
2434                 break;
2435         default:
2436                 if (nfs_parse_mount_options((char *)options, args) == 0)
2437                         return -EINVAL;
2438
2439                 if (!nfs_verify_server_address(sap))
2440                         return -EINVAL;
2441
2442                 return nfs4_validate_text_mount_data(options, args, dev_name);
2443         }
2444
2445         return 0;
2446
2447 out_no_data:
2448         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2449         return -EINVAL;
2450
2451 out_inval_auth:
2452         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2453                  data->auth_flavourlen);
2454         return -EINVAL;
2455
2456 out_no_address:
2457         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2458         return -EINVAL;
2459 }
2460
2461 /*
2462  * Get the superblock for the NFS4 root partition
2463  */
2464 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2465         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2466 {
2467         struct nfs_parsed_mount_data *data = raw_data;
2468         struct super_block *s;
2469         struct nfs_server *server;
2470         struct nfs_fh *mntfh;
2471         struct dentry *mntroot;
2472         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2473         struct nfs_sb_mountdata sb_mntdata = {
2474                 .mntflags = flags,
2475         };
2476         int error = -ENOMEM;
2477
2478         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2479         if (data == NULL || mntfh == NULL)
2480                 goto out_free_fh;
2481
2482         security_init_mnt_opts(&data->lsm_opts);
2483
2484         /* Get a volume representation */
2485         server = nfs4_create_server(data, mntfh);
2486         if (IS_ERR(server)) {
2487                 error = PTR_ERR(server);
2488                 goto out;
2489         }
2490         sb_mntdata.server = server;
2491
2492         if (server->flags & NFS4_MOUNT_UNSHARED)
2493                 compare_super = NULL;
2494
2495         /* Get a superblock - note that we may end up sharing one that already exists */
2496         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2497         if (IS_ERR(s)) {
2498                 error = PTR_ERR(s);
2499                 goto out_free;
2500         }
2501
2502         if (s->s_fs_info != server) {
2503                 nfs_free_server(server);
2504                 server = NULL;
2505         } else {
2506                 error = nfs_bdi_register(server);
2507                 if (error)
2508                         goto error_splat_super;
2509         }
2510
2511         if (!s->s_root) {
2512                 /* initial superblock/root creation */
2513                 nfs4_fill_super(s);
2514                 nfs_fscache_get_super_cookie(
2515                         s, data ? data->fscache_uniq : NULL, NULL);
2516         }
2517
2518         mntroot = nfs4_get_root(s, mntfh);
2519         if (IS_ERR(mntroot)) {
2520                 error = PTR_ERR(mntroot);
2521                 goto error_splat_super;
2522         }
2523
2524         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2525         if (error)
2526                 goto error_splat_root;
2527
2528         s->s_flags |= MS_ACTIVE;
2529         mnt->mnt_sb = s;
2530         mnt->mnt_root = mntroot;
2531         error = 0;
2532
2533 out:
2534         security_free_mnt_opts(&data->lsm_opts);
2535 out_free_fh:
2536         kfree(mntfh);
2537         return error;
2538
2539 out_free:
2540         nfs_free_server(server);
2541         goto out;
2542
2543 error_splat_root:
2544         dput(mntroot);
2545 error_splat_super:
2546         deactivate_locked_super(s);
2547         goto out;
2548 }
2549
2550 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2551                 int flags, void *data, const char *hostname)
2552 {
2553         struct vfsmount *root_mnt;
2554         char *root_devname;
2555         size_t len;
2556
2557         len = strlen(hostname) + 3;
2558         root_devname = kmalloc(len, GFP_KERNEL);
2559         if (root_devname == NULL)
2560                 return ERR_PTR(-ENOMEM);
2561         snprintf(root_devname, len, "%s:/", hostname);
2562         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2563         kfree(root_devname);
2564         return root_mnt;
2565 }
2566
2567 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2568 {
2569         char *page = (char *) __get_free_page(GFP_KERNEL);
2570         char *devname, *tmp;
2571
2572         if (page == NULL)
2573                 return;
2574         devname = nfs_path(path->mnt->mnt_devname,
2575                         path->mnt->mnt_root, path->dentry,
2576                         page, PAGE_SIZE);
2577         if (devname == NULL)
2578                 goto out_freepage;
2579         tmp = kstrdup(devname, GFP_KERNEL);
2580         if (tmp == NULL)
2581                 goto out_freepage;
2582         kfree(mnt->mnt_devname);
2583         mnt->mnt_devname = tmp;
2584 out_freepage:
2585         free_page((unsigned long)page);
2586 }
2587
2588 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2589                 const char *export_path, struct vfsmount *mnt_target)
2590 {
2591         struct mnt_namespace *ns_private;
2592         struct nameidata nd;
2593         struct super_block *s;
2594         int ret;
2595
2596         ns_private = create_mnt_ns(root_mnt);
2597         ret = PTR_ERR(ns_private);
2598         if (IS_ERR(ns_private))
2599                 goto out_mntput;
2600
2601         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2602                         export_path, LOOKUP_FOLLOW, &nd);
2603
2604         put_mnt_ns(ns_private);
2605
2606         if (ret != 0)
2607                 goto out_err;
2608
2609         s = nd.path.mnt->mnt_sb;
2610         atomic_inc(&s->s_active);
2611         mnt_target->mnt_sb = s;
2612         mnt_target->mnt_root = dget(nd.path.dentry);
2613
2614         /* Correct the device pathname */
2615         nfs_fix_devname(&nd.path, mnt_target);
2616
2617         path_put(&nd.path);
2618         down_write(&s->s_umount);
2619         return 0;
2620 out_mntput:
2621         mntput(root_mnt);
2622 out_err:
2623         return ret;
2624 }
2625
2626 static int nfs4_try_mount(int flags, const char *dev_name,
2627                          struct nfs_parsed_mount_data *data,
2628                          struct vfsmount *mnt)
2629 {
2630         char *export_path;
2631         struct vfsmount *root_mnt;
2632         int error;
2633
2634         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2635
2636         export_path = data->nfs_server.export_path;
2637         data->nfs_server.export_path = "/";
2638         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2639                         data->nfs_server.hostname);
2640         data->nfs_server.export_path = export_path;
2641
2642         error = PTR_ERR(root_mnt);
2643         if (IS_ERR(root_mnt))
2644                 goto out;
2645
2646         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2647
2648 out:
2649         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2650                         error != 0 ? " [error]" : "");
2651         return error;
2652 }
2653
2654 /*
2655  * Get the superblock for an NFS4 mountpoint
2656  */
2657 static int nfs4_get_sb(struct file_system_type *fs_type,
2658         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2659 {
2660         struct nfs_parsed_mount_data *data;
2661         int error = -ENOMEM;
2662
2663         data = nfs_alloc_parsed_mount_data(4);
2664         if (data == NULL)
2665                 goto out_free_data;
2666
2667         /* Validate the mount data */
2668         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2669         if (error < 0)
2670                 goto out;
2671
2672         error = nfs4_try_mount(flags, dev_name, data, mnt);
2673
2674 out:
2675         kfree(data->client_address);
2676         kfree(data->nfs_server.export_path);
2677         kfree(data->nfs_server.hostname);
2678         kfree(data->fscache_uniq);
2679 out_free_data:
2680         kfree(data);
2681         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2682                         error != 0 ? " [error]" : "");
2683         return error;
2684 }
2685
2686 static void nfs4_kill_super(struct super_block *sb)
2687 {
2688         struct nfs_server *server = NFS_SB(sb);
2689
2690         dprintk("--> %s\n", __func__);
2691         nfs_super_return_all_delegations(sb);
2692         kill_anon_super(sb);
2693         nfs_fscache_release_super_cookie(sb);
2694         nfs_free_server(server);
2695         dprintk("<-- %s\n", __func__);
2696 }
2697
2698 /*
2699  * Clone an NFS4 server record on xdev traversal (FSID-change)
2700  */
2701 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2702                             const char *dev_name, void *raw_data,
2703                             struct vfsmount *mnt)
2704 {
2705         struct nfs_clone_mount *data = raw_data;
2706         struct super_block *s;
2707         struct nfs_server *server;
2708         struct dentry *mntroot;
2709         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2710         struct nfs_sb_mountdata sb_mntdata = {
2711                 .mntflags = flags,
2712         };
2713         int error;
2714
2715         dprintk("--> nfs4_xdev_get_sb()\n");
2716
2717         /* create a new volume representation */
2718         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2719         if (IS_ERR(server)) {
2720                 error = PTR_ERR(server);
2721                 goto out_err_noserver;
2722         }
2723         sb_mntdata.server = server;
2724
2725         if (server->flags & NFS4_MOUNT_UNSHARED)
2726                 compare_super = NULL;
2727
2728         /* Get a superblock - note that we may end up sharing one that already exists */
2729         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2730         if (IS_ERR(s)) {
2731                 error = PTR_ERR(s);
2732                 goto out_err_nosb;
2733         }
2734
2735         if (s->s_fs_info != server) {
2736                 nfs_free_server(server);
2737                 server = NULL;
2738         } else {
2739                 error = nfs_bdi_register(server);
2740                 if (error)
2741                         goto error_splat_super;
2742         }
2743
2744         if (!s->s_root) {
2745                 /* initial superblock/root creation */
2746                 nfs4_clone_super(s, data->sb);
2747                 nfs_fscache_get_super_cookie(s, NULL, data);
2748         }
2749
2750         mntroot = nfs4_get_root(s, data->fh);
2751         if (IS_ERR(mntroot)) {
2752                 error = PTR_ERR(mntroot);
2753                 goto error_splat_super;
2754         }
2755         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2756                 dput(mntroot);
2757                 error = -ESTALE;
2758                 goto error_splat_super;
2759         }
2760
2761         s->s_flags |= MS_ACTIVE;
2762         mnt->mnt_sb = s;
2763         mnt->mnt_root = mntroot;
2764
2765         security_sb_clone_mnt_opts(data->sb, s);
2766
2767         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2768         return 0;
2769
2770 out_err_nosb:
2771         nfs_free_server(server);
2772 out_err_noserver:
2773         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2774         return error;
2775
2776 error_splat_super:
2777         deactivate_locked_super(s);
2778         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2779         return error;
2780 }
2781
2782 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2783                 int flags, const char *dev_name, void *raw_data,
2784                 struct vfsmount *mnt)
2785 {
2786         struct nfs_clone_mount *data = raw_data;
2787         struct super_block *s;
2788         struct nfs_server *server;
2789         struct dentry *mntroot;
2790         struct nfs_fh mntfh;
2791         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2792         struct nfs_sb_mountdata sb_mntdata = {
2793                 .mntflags = flags,
2794         };
2795         int error;
2796
2797         dprintk("--> nfs4_referral_get_sb()\n");
2798
2799         /* create a new volume representation */
2800         server = nfs4_create_referral_server(data, &mntfh);
2801         if (IS_ERR(server)) {
2802                 error = PTR_ERR(server);
2803                 goto out_err_noserver;
2804         }
2805         sb_mntdata.server = server;
2806
2807         if (server->flags & NFS4_MOUNT_UNSHARED)
2808                 compare_super = NULL;
2809
2810         /* Get a superblock - note that we may end up sharing one that already exists */
2811         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2812         if (IS_ERR(s)) {
2813                 error = PTR_ERR(s);
2814                 goto out_err_nosb;
2815         }
2816
2817         if (s->s_fs_info != server) {
2818                 nfs_free_server(server);
2819                 server = NULL;
2820         } else {
2821                 error = nfs_bdi_register(server);
2822                 if (error)
2823                         goto error_splat_super;
2824         }
2825
2826         if (!s->s_root) {
2827                 /* initial superblock/root creation */
2828                 nfs4_fill_super(s);
2829                 nfs_fscache_get_super_cookie(s, NULL, data);
2830         }
2831
2832         mntroot = nfs4_get_root(s, &mntfh);
2833         if (IS_ERR(mntroot)) {
2834                 error = PTR_ERR(mntroot);
2835                 goto error_splat_super;
2836         }
2837         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2838                 dput(mntroot);
2839                 error = -ESTALE;
2840                 goto error_splat_super;
2841         }
2842
2843         s->s_flags |= MS_ACTIVE;
2844         mnt->mnt_sb = s;
2845         mnt->mnt_root = mntroot;
2846
2847         security_sb_clone_mnt_opts(data->sb, s);
2848
2849         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2850         return 0;
2851
2852 out_err_nosb:
2853         nfs_free_server(server);
2854 out_err_noserver:
2855         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2856         return error;
2857
2858 error_splat_super:
2859         deactivate_locked_super(s);
2860         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2861         return error;
2862 }
2863
2864 /*
2865  * Create an NFS4 server record on referral traversal
2866  */
2867 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2868                 int flags, const char *dev_name, void *raw_data,
2869                 struct vfsmount *mnt)
2870 {
2871         struct nfs_clone_mount *data = raw_data;
2872         char *export_path;
2873         struct vfsmount *root_mnt;
2874         int error;
2875
2876         dprintk("--> nfs4_referral_get_sb()\n");
2877
2878         export_path = data->mnt_path;
2879         data->mnt_path = "/";
2880
2881         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2882                         flags, data, data->hostname);
2883         data->mnt_path = export_path;
2884
2885         error = PTR_ERR(root_mnt);
2886         if (IS_ERR(root_mnt))
2887                 goto out;
2888
2889         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2890 out:
2891         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2892                         error != 0 ? " [error]" : "");
2893         return error;
2894 }
2895
2896 #endif /* CONFIG_NFS_V4 */