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 /*
 732  * Sanity-check a server address provided by the mount command.
 733  *
 734  * Address family must be initialized, and address must not be
 735  * the ANY address for that family.
 736  */
 737 static int nfs_verify_server_address(struct sockaddr *addr)
 738 {
 739         switch (addr->sa_family) {
 740         case AF_INET: {
 741                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 742                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 743         }
 744         case AF_INET6: {
 745                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 746                 return !ipv6_addr_any(sa);
 747         }
 748         }
 749
 750         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 751         return 0;
 752 }
 753
 754 /*
 755  * Select between a default port value and a user-specified port value.
 756  * If a zero value is set, then autobind will be used.
 757  */
 758 static void nfs_set_default_port(struct sockaddr *sap, const int parsed_port,
 759                                  const unsigned short default_port)
 760 {
 761         unsigned short port = default_port;
 762
 763         if (parsed_port != NFS_UNSPEC_PORT)
 764                 port = parsed_port;
 765
 766         rpc_set_port(sap, port);
 767 }
 768
 769 /*
 770  * Sanity check the NFS transport protocol.
 771  *
 772  */
 773 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 774 {
 775         switch (mnt->nfs_server.protocol) {
 776         case XPRT_TRANSPORT_UDP:
 777         case XPRT_TRANSPORT_TCP:
 778         case XPRT_TRANSPORT_RDMA:
 779                 break;
 780         default:
 781                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 782         }
 783 }
 784
 785 /*
 786  * For text based NFSv2/v3 mounts, the mount protocol transport default
 787  * settings should depend upon the specified NFS transport.
 788  */
 789 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 790 {
 791         nfs_validate_transport_protocol(mnt);
 792
 793         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 794             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 795                         return;
 796         switch (mnt->nfs_server.protocol) {
 797         case XPRT_TRANSPORT_UDP:
 798                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 799                 break;
 800         case XPRT_TRANSPORT_TCP:
 801         case XPRT_TRANSPORT_RDMA:
 802                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 803         }
 804 }
 805
 806 /*
 807  * Parse the value of the 'sec=' option.
 808  */
 809 static int nfs_parse_security_flavors(char *value,
 810                                       struct nfs_parsed_mount_data *mnt)
 811 {
 812         substring_t args[MAX_OPT_ARGS];
 813
 814         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 815
 816         switch (match_token(value, nfs_secflavor_tokens, args)) {
 817         case Opt_sec_none:
 818                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 819                 break;
 820         case Opt_sec_sys:
 821                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 822                 break;
 823         case Opt_sec_krb5:
 824                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 825                 break;
 826         case Opt_sec_krb5i:
 827                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 828                 break;
 829         case Opt_sec_krb5p:
 830                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 831                 break;
 832         case Opt_sec_lkey:
 833                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 834                 break;
 835         case Opt_sec_lkeyi:
 836                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 837                 break;
 838         case Opt_sec_lkeyp:
 839                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 840                 break;
 841         case Opt_sec_spkm:
 842                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 843                 break;
 844         case Opt_sec_spkmi:
 845                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 846                 break;
 847         case Opt_sec_spkmp:
 848                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 849                 break;
 850         default:
 851                 return 0;
 852         }
 853
 854         mnt->auth_flavor_len = 1;
 855         return 1;
 856 }
 857
 858 /*
 859  * Error-check and convert a string of mount options from user space into
 860  * a data structure.  The whole mount string is processed; bad options are
 861  * skipped as they are encountered.  If there were no errors, return 1;
 862  * otherwise return 0 (zero).
 863  */
 864 static int nfs_parse_mount_options(char *raw,
 865                                    struct nfs_parsed_mount_data *mnt)
 866 {
 867         char *p, *string, *secdata;
 868         int rc, sloppy = 0, invalid_option = 0;
 869
 870         if (!raw) {
 871                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 872                 return 1;
 873         }
 874         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 875
 876         secdata = alloc_secdata();
 877         if (!secdata)
 878                 goto out_nomem;
 879
 880         rc = security_sb_copy_data(raw, secdata);
 881         if (rc)
 882                 goto out_security_failure;
 883
 884         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 885         if (rc)
 886                 goto out_security_failure;
 887
 888         free_secdata(secdata);
 889
 890         while ((p = strsep(&raw, ",")) != NULL) {
 891                 substring_t args[MAX_OPT_ARGS];
 892                 unsigned long option;
 893                 int token;
 894
 895                 if (!*p)
 896                         continue;
 897
 898                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 899
 900                 token = match_token(p, nfs_mount_option_tokens, args);
 901                 switch (token) {
 902
 903                 /*
 904                  * boolean options:  foo/nofoo
 905                  */
 906                 case Opt_soft:
 907                         mnt->flags |= NFS_MOUNT_SOFT;
 908                         break;
 909                 case Opt_hard:
 910                         mnt->flags &= ~NFS_MOUNT_SOFT;
 911                         break;
 912                 case Opt_posix:
 913                         mnt->flags |= NFS_MOUNT_POSIX;
 914                         break;
 915                 case Opt_noposix:
 916                         mnt->flags &= ~NFS_MOUNT_POSIX;
 917                         break;
 918                 case Opt_cto:
 919                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 920                         break;
 921                 case Opt_nocto:
 922                         mnt->flags |= NFS_MOUNT_NOCTO;
 923                         break;
 924                 case Opt_ac:
 925                         mnt->flags &= ~NFS_MOUNT_NOAC;
 926                         break;
 927                 case Opt_noac:
 928                         mnt->flags |= NFS_MOUNT_NOAC;
 929                         break;
 930                 case Opt_lock:
 931                         mnt->flags &= ~NFS_MOUNT_NONLM;
 932                         break;
 933                 case Opt_nolock:
 934                         mnt->flags |= NFS_MOUNT_NONLM;
 935                         break;
 936                 case Opt_v2:
 937                         mnt->flags &= ~NFS_MOUNT_VER3;
 938                         mnt->version = 2;
 939                         break;
 940                 case Opt_v3:
 941                         mnt->flags |= NFS_MOUNT_VER3;
 942                         mnt->version = 3;
 943                         break;
 944 #ifdef CONFIG_NFS_V4
 945                 case Opt_v4:
 946                         mnt->flags &= ~NFS_MOUNT_VER3;
 947                         mnt->version = 4;
 948                         break;
 949 #endif
 950                 case Opt_udp:
 951                         mnt->flags &= ~NFS_MOUNT_TCP;
 952                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 953                         break;
 954                 case Opt_tcp:
 955                         mnt->flags |= NFS_MOUNT_TCP;
 956                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 957                         break;
 958                 case Opt_rdma:
 959                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 960                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 961                         xprt_load_transport(p);
 962                         break;
 963                 case Opt_acl:
 964                         mnt->flags &= ~NFS_MOUNT_NOACL;
 965                         break;
 966                 case Opt_noacl:
 967                         mnt->flags |= NFS_MOUNT_NOACL;
 968                         break;
 969                 case Opt_rdirplus:
 970                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 971                         break;
 972                 case Opt_nordirplus:
 973                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 974                         break;
 975                 case Opt_sharecache:
 976                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 977                         break;
 978                 case Opt_nosharecache:
 979                         mnt->flags |= NFS_MOUNT_UNSHARED;
 980                         break;
 981                 case Opt_resvport:
 982                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
 983                         break;
 984                 case Opt_noresvport:
 985                         mnt->flags |= NFS_MOUNT_NORESVPORT;
 986                         break;
 987                 case Opt_fscache:
 988                         mnt->options |= NFS_OPTION_FSCACHE;
 989                         kfree(mnt->fscache_uniq);
 990                         mnt->fscache_uniq = NULL;
 991                         break;
 992                 case Opt_nofscache:
 993                         mnt->options &= ~NFS_OPTION_FSCACHE;
 994                         kfree(mnt->fscache_uniq);
 995                         mnt->fscache_uniq = NULL;
 996                         break;
 997                 case Opt_fscache_uniq:
 998                         string = match_strdup(args);
 999                         if (!string)
1000                                 goto out_nomem;
1001                         kfree(mnt->fscache_uniq);
1002                         mnt->fscache_uniq = string;
1003                         mnt->options |= NFS_OPTION_FSCACHE;
1004                         break;
1005
1006                 /*
1007                  * options that take numeric values
1008                  */
1009                 case Opt_port:
1010                         string = match_strdup(args);
1011                         if (string == NULL)
1012                                 goto out_nomem;
1013                         rc = strict_strtoul(string, 10, &option);
1014                         kfree(string);
1015                         if (rc != 0 || option > USHORT_MAX)
1016                                 goto out_invalid_value;
1017                         mnt->nfs_server.port = option;
1018                         break;
1019                 case Opt_rsize:
1020                         string = match_strdup(args);
1021                         if (string == NULL)
1022                                 goto out_nomem;
1023                         rc = strict_strtoul(string, 10, &option);
1024                         kfree(string);
1025                         if (rc != 0)
1026                                 goto out_invalid_value;
1027                         mnt->rsize = option;
1028                         break;
1029                 case Opt_wsize:
1030                         string = match_strdup(args);
1031                         if (string == NULL)
1032                                 goto out_nomem;
1033                         rc = strict_strtoul(string, 10, &option);
1034                         kfree(string);
1035                         if (rc != 0)
1036                                 goto out_invalid_value;
1037                         mnt->wsize = option;
1038                         break;
1039                 case Opt_bsize:
1040                         string = match_strdup(args);
1041                         if (string == NULL)
1042                                 goto out_nomem;
1043                         rc = strict_strtoul(string, 10, &option);
1044                         kfree(string);
1045                         if (rc != 0)
1046                                 goto out_invalid_value;
1047                         mnt->bsize = option;
1048                         break;
1049                 case Opt_timeo:
1050                         string = match_strdup(args);
1051                         if (string == NULL)
1052                                 goto out_nomem;
1053                         rc = strict_strtoul(string, 10, &option);
1054                         kfree(string);
1055                         if (rc != 0 || option == 0)
1056                                 goto out_invalid_value;
1057                         mnt->timeo = option;
1058                         break;
1059                 case Opt_retrans:
1060                         string = match_strdup(args);
1061                         if (string == NULL)
1062                                 goto out_nomem;
1063                         rc = strict_strtoul(string, 10, &option);
1064                         kfree(string);
1065                         if (rc != 0 || option == 0)
1066                                 goto out_invalid_value;
1067                         mnt->retrans = option;
1068                         break;
1069                 case Opt_acregmin:
1070                         string = match_strdup(args);
1071                         if (string == NULL)
1072                                 goto out_nomem;
1073                         rc = strict_strtoul(string, 10, &option);
1074                         kfree(string);
1075                         if (rc != 0)
1076                                 goto out_invalid_value;
1077                         mnt->acregmin = option;
1078                         break;
1079                 case Opt_acregmax:
1080                         string = match_strdup(args);
1081                         if (string == NULL)
1082                                 goto out_nomem;
1083                         rc = strict_strtoul(string, 10, &option);
1084                         kfree(string);
1085                         if (rc != 0)
1086                                 goto out_invalid_value;
1087                         mnt->acregmax = option;
1088                         break;
1089                 case Opt_acdirmin:
1090                         string = match_strdup(args);
1091                         if (string == NULL)
1092                                 goto out_nomem;
1093                         rc = strict_strtoul(string, 10, &option);
1094                         kfree(string);
1095                         if (rc != 0)
1096                                 goto out_invalid_value;
1097                         mnt->acdirmin = option;
1098                         break;
1099                 case Opt_acdirmax:
1100                         string = match_strdup(args);
1101                         if (string == NULL)
1102                                 goto out_nomem;
1103                         rc = strict_strtoul(string, 10, &option);
1104                         kfree(string);
1105                         if (rc != 0)
1106                                 goto out_invalid_value;
1107                         mnt->acdirmax = option;
1108                         break;
1109                 case Opt_actimeo:
1110                         string = match_strdup(args);
1111                         if (string == NULL)
1112                                 goto out_nomem;
1113                         rc = strict_strtoul(string, 10, &option);
1114                         kfree(string);
1115                         if (rc != 0)
1116                                 goto out_invalid_value;
1117                         mnt->acregmin = mnt->acregmax =
1118                         mnt->acdirmin = mnt->acdirmax = option;
1119                         break;
1120                 case Opt_namelen:
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->namlen = option;
1129                         break;
1130                 case Opt_mountport:
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 || option > USHORT_MAX)
1137                                 goto out_invalid_value;
1138                         mnt->mount_server.port = option;
1139                         break;
1140                 case Opt_mountvers:
1141                         string = match_strdup(args);
1142                         if (string == NULL)
1143                                 goto out_nomem;
1144                         rc = strict_strtoul(string, 10, &option);
1145                         kfree(string);
1146                         if (rc != 0 ||
1147                             option < NFS_MNT_VERSION ||
1148                             option > NFS_MNT3_VERSION)
1149                                 goto out_invalid_value;
1150                         mnt->mount_server.version = option;
1151                         break;
1152                 case Opt_nfsvers:
1153                         string = match_strdup(args);
1154                         if (string == NULL)
1155                                 goto out_nomem;
1156                         rc = strict_strtoul(string, 10, &option);
1157                         kfree(string);
1158                         if (rc != 0)
1159                                 goto out_invalid_value;
1160                         switch (option) {
1161                         case NFS2_VERSION:
1162                                 mnt->flags &= ~NFS_MOUNT_VER3;
1163                                 mnt->version = 2;
1164                                 break;
1165                         case NFS3_VERSION:
1166                                 mnt->flags |= NFS_MOUNT_VER3;
1167                                 mnt->version = 3;
1168                                 break;
1169 #ifdef CONFIG_NFS_V4
1170                         case NFS4_VERSION:
1171                                 mnt->flags &= ~NFS_MOUNT_VER3;
1172                                 mnt->version = 4;
1173                                 break;
1174 #endif
1175                         default:
1176                                 goto out_invalid_value;
1177                         }
1178                         break;
1179                 case Opt_minorversion:
1180                         string = match_strdup(args);
1181                         if (string == NULL)
1182                                 goto out_nomem;
1183                         rc = strict_strtoul(string, 10, &option);
1184                         kfree(string);
1185                         if (rc != 0)
1186                                 goto out_invalid_value;
1187                         if (option > NFS4_MAX_MINOR_VERSION)
1188                                 goto out_invalid_value;
1189                         mnt->minorversion = option;
1190                         break;
1191
1192                 /*
1193                  * options that take text values
1194                  */
1195                 case Opt_sec:
1196                         string = match_strdup(args);
1197                         if (string == NULL)
1198                                 goto out_nomem;
1199                         rc = nfs_parse_security_flavors(string, mnt);
1200                         kfree(string);
1201                         if (!rc) {
1202                                 dfprintk(MOUNT, "NFS:   unrecognized "
1203                                                 "security flavor\n");
1204                                 return 0;
1205                         }
1206                         break;
1207                 case Opt_proto:
1208                         string = match_strdup(args);
1209                         if (string == NULL)
1210                                 goto out_nomem;
1211                         token = match_token(string,
1212                                             nfs_xprt_protocol_tokens, args);
1213
1214                         switch (token) {
1215                         case Opt_xprt_udp:
1216                                 mnt->flags &= ~NFS_MOUNT_TCP;
1217                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1218                                 kfree(string);
1219                                 break;
1220                         case Opt_xprt_tcp:
1221                                 mnt->flags |= NFS_MOUNT_TCP;
1222                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1223                                 kfree(string);
1224                                 break;
1225                         case Opt_xprt_rdma:
1226                                 /* vector side protocols to TCP */
1227                                 mnt->flags |= NFS_MOUNT_TCP;
1228                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1229                                 xprt_load_transport(string);
1230                                 kfree(string);
1231                                 break;
1232                         default:
1233                                 dfprintk(MOUNT, "NFS:   unrecognized "
1234                                                 "transport protocol\n");
1235                                 return 0;
1236                         }
1237                         break;
1238                 case Opt_mountproto:
1239                         string = match_strdup(args);
1240                         if (string == NULL)
1241                                 goto out_nomem;
1242                         token = match_token(string,
1243                                             nfs_xprt_protocol_tokens, args);
1244                         kfree(string);
1245
1246                         switch (token) {
1247                         case Opt_xprt_udp:
1248                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1249                                 break;
1250                         case Opt_xprt_tcp:
1251                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1252                                 break;
1253                         case Opt_xprt_rdma: /* not used for side protocols */
1254                         default:
1255                                 dfprintk(MOUNT, "NFS:   unrecognized "
1256                                                 "transport protocol\n");
1257                                 return 0;
1258                         }
1259                         break;
1260                 case Opt_addr:
1261                         string = match_strdup(args);
1262                         if (string == NULL)
1263                                 goto out_nomem;
1264                         mnt->nfs_server.addrlen =
1265                                 rpc_pton(string, strlen(string),
1266                                         (struct sockaddr *)
1267                                         &mnt->nfs_server.address,
1268                                         sizeof(mnt->nfs_server.address));
1269                         kfree(string);
1270                         if (mnt->nfs_server.addrlen == 0)
1271                                 goto out_invalid_address;
1272                         break;
1273                 case Opt_clientaddr:
1274                         string = match_strdup(args);
1275                         if (string == NULL)
1276                                 goto out_nomem;
1277                         kfree(mnt->client_address);
1278                         mnt->client_address = string;
1279                         break;
1280                 case Opt_mounthost:
1281                         string = match_strdup(args);
1282                         if (string == NULL)
1283                                 goto out_nomem;
1284                         kfree(mnt->mount_server.hostname);
1285                         mnt->mount_server.hostname = string;
1286                         break;
1287                 case Opt_mountaddr:
1288                         string = match_strdup(args);
1289                         if (string == NULL)
1290                                 goto out_nomem;
1291                         mnt->mount_server.addrlen =
1292                                 rpc_pton(string, strlen(string),
1293                                         (struct sockaddr *)
1294                                         &mnt->mount_server.address,
1295                                         sizeof(mnt->mount_server.address));
1296                         kfree(string);
1297                         if (mnt->mount_server.addrlen == 0)
1298                                 goto out_invalid_address;
1299                         break;
1300                 case Opt_lookupcache:
1301                         string = match_strdup(args);
1302                         if (string == NULL)
1303                                 goto out_nomem;
1304                         token = match_token(string,
1305                                         nfs_lookupcache_tokens, args);
1306                         kfree(string);
1307                         switch (token) {
1308                                 case Opt_lookupcache_all:
1309                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1310                                         break;
1311                                 case Opt_lookupcache_positive:
1312                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1313                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1314                                         break;
1315                                 case Opt_lookupcache_none:
1316                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1317                                         break;
1318                                 default:
1319                                         dfprintk(MOUNT, "NFS:   invalid "
1320                                                         "lookupcache argument\n");
1321                                         return 0;
1322                         };
1323                         break;
1324
1325                 /*
1326                  * Special options
1327                  */
1328                 case Opt_sloppy:
1329                         sloppy = 1;
1330                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1331                         break;
1332                 case Opt_userspace:
1333                 case Opt_deprecated:
1334                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1335                                         "'%s'\n", p);
1336                         break;
1337
1338                 default:
1339                         invalid_option = 1;
1340                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1341                                         "'%s'\n", p);
1342                 }
1343         }
1344
1345         if (!sloppy && invalid_option)
1346                 return 0;
1347
1348         return 1;
1349
1350 out_invalid_address:
1351         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1352         return 0;
1353 out_invalid_value:
1354         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1355         return 0;
1356 out_nomem:
1357         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1358         return 0;
1359 out_security_failure:
1360         free_secdata(secdata);
1361         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1362         return 0;
1363 }
1364
1365 /*
1366  * Match the requested auth flavors with the list returned by
1367  * the server.  Returns zero and sets the mount's authentication
1368  * flavor on success; returns -EACCES if server does not support
1369  * the requested flavor.
1370  */
1371 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1372                              struct nfs_mount_request *request)
1373 {
1374         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1375
1376         /*
1377          * Certain releases of Linux's mountd return an empty
1378          * flavor list.  To prevent behavioral regression with
1379          * these servers (ie. rejecting mounts that used to
1380          * succeed), revert to pre-2.6.32 behavior (no checking)
1381          * if the returned flavor list is empty.
1382          */
1383         if (server_authlist_len == 0)
1384                 return 0;
1385
1386         /*
1387          * We avoid sophisticated negotiating here, as there are
1388          * plenty of cases where we can get it wrong, providing
1389          * either too little or too much security.
1390          *
1391          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1392          * flavor listed first.  However, some servers list
1393          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1394          * preferred default, in args->auth_flavors[0] if user
1395          * didn't specify sec= mount option.
1396          */
1397         for (i = 0; i < args->auth_flavor_len; i++)
1398                 for (j = 0; j < server_authlist_len; j++)
1399                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1400                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1401                                         request->auth_flavs[j]);
1402                                 args->auth_flavors[0] = request->auth_flavs[j];
1403                                 return 0;
1404                         }
1405
1406         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1407         nfs_umount(request);
1408         return -EACCES;
1409 }
1410
1411 /*
1412  * Use the remote server's MOUNT service to request the NFS file handle
1413  * corresponding to the provided path.
1414  */
1415 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1416                          struct nfs_fh *root_fh)
1417 {
1418         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1419         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1420         struct nfs_mount_request request = {
1421                 .sap            = (struct sockaddr *)
1422                                                 &args->mount_server.address,
1423                 .dirpath        = args->nfs_server.export_path,
1424                 .protocol       = args->mount_server.protocol,
1425                 .fh             = root_fh,
1426                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1427                 .auth_flav_len  = &server_authlist_len,
1428                 .auth_flavs     = server_authlist,
1429         };
1430         int status;
1431
1432         if (args->mount_server.version == 0) {
1433                 if (args->flags & NFS_MOUNT_VER3)
1434                         args->mount_server.version = NFS_MNT3_VERSION;
1435                 else
1436                         args->mount_server.version = NFS_MNT_VERSION;
1437         }
1438         request.version = args->mount_server.version;
1439
1440         if (args->mount_server.hostname)
1441                 request.hostname = args->mount_server.hostname;
1442         else
1443                 request.hostname = args->nfs_server.hostname;
1444
1445         /*
1446          * Construct the mount server's address.
1447          */
1448         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1449                 memcpy(request.sap, &args->nfs_server.address,
1450                        args->nfs_server.addrlen);
1451                 args->mount_server.addrlen = args->nfs_server.addrlen;
1452         }
1453         request.salen = args->mount_server.addrlen;
1454         nfs_set_default_port(request.sap, args->mount_server.port, 0);
1455
1456         /*
1457          * Now ask the mount server to map our export path
1458          * to a file handle.
1459          */
1460         status = nfs_mount(&request);
1461         if (status != 0) {
1462                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1463                                 request.hostname, status);
1464                 return status;
1465         }
1466
1467         /*
1468          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1469          */
1470         if (args->mount_server.version != NFS_MNT3_VERSION)
1471                 return 0;
1472         return nfs_walk_authlist(args, &request);
1473 }
1474
1475 static int nfs_parse_simple_hostname(const char *dev_name,
1476                                      char **hostname, size_t maxnamlen,
1477                                      char **export_path, size_t maxpathlen)
1478 {
1479         size_t len;
1480         char *colon, *comma;
1481
1482         colon = strchr(dev_name, ':');
1483         if (colon == NULL)
1484                 goto out_bad_devname;
1485
1486         len = colon - dev_name;
1487         if (len > maxnamlen)
1488                 goto out_hostname;
1489
1490         /* N.B. caller will free nfs_server.hostname in all cases */
1491         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1492         if (!*hostname)
1493                 goto out_nomem;
1494
1495         /* kill possible hostname list: not supported */
1496         comma = strchr(*hostname, ',');
1497         if (comma != NULL) {
1498                 if (comma == *hostname)
1499                         goto out_bad_devname;
1500                 *comma = '\0';
1501         }
1502
1503         colon++;
1504         len = strlen(colon);
1505         if (len > maxpathlen)
1506                 goto out_path;
1507         *export_path = kstrndup(colon, len, GFP_KERNEL);
1508         if (!*export_path)
1509                 goto out_nomem;
1510
1511         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1512         return 0;
1513
1514 out_bad_devname:
1515         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1516         return -EINVAL;
1517
1518 out_nomem:
1519         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1520         return -ENOMEM;
1521
1522 out_hostname:
1523         dfprintk(MOUNT, "NFS: server hostname too long\n");
1524         return -ENAMETOOLONG;
1525
1526 out_path:
1527         dfprintk(MOUNT, "NFS: export pathname too long\n");
1528         return -ENAMETOOLONG;
1529 }
1530
1531 /*
1532  * Hostname has square brackets around it because it contains one or
1533  * more colons.  We look for the first closing square bracket, and a
1534  * colon must follow it.
1535  */
1536 static int nfs_parse_protected_hostname(const char *dev_name,
1537                                         char **hostname, size_t maxnamlen,
1538                                         char **export_path, size_t maxpathlen)
1539 {
1540         size_t len;
1541         char *start, *end;
1542
1543         start = (char *)(dev_name + 1);
1544
1545         end = strchr(start, ']');
1546         if (end == NULL)
1547                 goto out_bad_devname;
1548         if (*(end + 1) != ':')
1549                 goto out_bad_devname;
1550
1551         len = end - start;
1552         if (len > maxnamlen)
1553                 goto out_hostname;
1554
1555         /* N.B. caller will free nfs_server.hostname in all cases */
1556         *hostname = kstrndup(start, len, GFP_KERNEL);
1557         if (*hostname == NULL)
1558                 goto out_nomem;
1559
1560         end += 2;
1561         len = strlen(end);
1562         if (len > maxpathlen)
1563                 goto out_path;
1564         *export_path = kstrndup(end, len, GFP_KERNEL);
1565         if (!*export_path)
1566                 goto out_nomem;
1567
1568         return 0;
1569
1570 out_bad_devname:
1571         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1572         return -EINVAL;
1573
1574 out_nomem:
1575         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1576         return -ENOMEM;
1577
1578 out_hostname:
1579         dfprintk(MOUNT, "NFS: server hostname too long\n");
1580         return -ENAMETOOLONG;
1581
1582 out_path:
1583         dfprintk(MOUNT, "NFS: export pathname too long\n");
1584         return -ENAMETOOLONG;
1585 }
1586
1587 /*
1588  * Split "dev_name" into "hostname:export_path".
1589  *
1590  * The leftmost colon demarks the split between the server's hostname
1591  * and the export path.  If the hostname starts with a left square
1592  * bracket, then it may contain colons.
1593  *
1594  * Note: caller frees hostname and export path, even on error.
1595  */
1596 static int nfs_parse_devname(const char *dev_name,
1597                              char **hostname, size_t maxnamlen,
1598                              char **export_path, size_t maxpathlen)
1599 {
1600         if (*dev_name == '[')
1601                 return nfs_parse_protected_hostname(dev_name,
1602                                                     hostname, maxnamlen,
1603                                                     export_path, maxpathlen);
1604
1605         return nfs_parse_simple_hostname(dev_name,
1606                                          hostname, maxnamlen,
1607                                          export_path, maxpathlen);
1608 }
1609
1610 /*
1611  * Validate the NFS2/NFS3 mount data
1612  * - fills in the mount root filehandle
1613  *
1614  * For option strings, user space handles the following behaviors:
1615  *
1616  * + DNS: mapping server host name to IP address ("addr=" option)
1617  *
1618  * + failure mode: how to behave if a mount request can't be handled
1619  *   immediately ("fg/bg" option)
1620  *
1621  * + retry: how often to retry a mount request ("retry=" option)
1622  *
1623  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1624  *   mountproto=tcp after mountproto=udp, and so on
1625  */
1626 static int nfs_validate_mount_data(void *options,
1627                                    struct nfs_parsed_mount_data *args,
1628                                    struct nfs_fh *mntfh,
1629                                    const char *dev_name)
1630 {
1631         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1632         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1633
1634         if (data == NULL)
1635                 goto out_no_data;
1636
1637         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1638         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1639         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1640         args->acregmin          = NFS_DEF_ACREGMIN;
1641         args->acregmax          = NFS_DEF_ACREGMAX;
1642         args->acdirmin          = NFS_DEF_ACDIRMIN;
1643         args->acdirmax          = NFS_DEF_ACDIRMAX;
1644         args->mount_server.port = NFS_UNSPEC_PORT;
1645         args->nfs_server.port   = NFS_UNSPEC_PORT;
1646         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1647         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1648         args->auth_flavor_len   = 1;
1649         args->minorversion      = 0;
1650
1651         switch (data->version) {
1652         case 1:
1653                 data->namlen = 0;
1654         case 2:
1655                 data->bsize = 0;
1656         case 3:
1657                 if (data->flags & NFS_MOUNT_VER3)
1658                         goto out_no_v3;
1659                 data->root.size = NFS2_FHSIZE;
1660                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1661         case 4:
1662                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1663                         goto out_no_sec;
1664         case 5:
1665                 memset(data->context, 0, sizeof(data->context));
1666         case 6:
1667                 if (data->flags & NFS_MOUNT_VER3) {
1668                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1669                                 goto out_invalid_fh;
1670                         mntfh->size = data->root.size;
1671                         args->version = 3;
1672                 } else {
1673                         mntfh->size = NFS2_FHSIZE;
1674                         args->version = 2;
1675                 }
1676
1677
1678                 memcpy(mntfh->data, data->root.data, mntfh->size);
1679                 if (mntfh->size < sizeof(mntfh->data))
1680                         memset(mntfh->data + mntfh->size, 0,
1681                                sizeof(mntfh->data) - mntfh->size);
1682
1683                 /*
1684                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1685                  * can deal with.
1686                  */
1687                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1688                 args->rsize             = data->rsize;
1689                 args->wsize             = data->wsize;
1690                 args->timeo             = data->timeo;
1691                 args->retrans           = data->retrans;
1692                 args->acregmin          = data->acregmin;
1693                 args->acregmax          = data->acregmax;
1694                 args->acdirmin          = data->acdirmin;
1695                 args->acdirmax          = data->acdirmax;
1696
1697                 memcpy(sap, &data->addr, sizeof(data->addr));
1698                 args->nfs_server.addrlen = sizeof(data->addr);
1699                 if (!nfs_verify_server_address(sap))
1700                         goto out_no_address;
1701
1702                 if (!(data->flags & NFS_MOUNT_TCP))
1703                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1704                 /* N.B. caller will free nfs_server.hostname in all cases */
1705                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1706                 args->namlen            = data->namlen;
1707                 args->bsize             = data->bsize;
1708
1709                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1710                         args->auth_flavors[0] = data->pseudoflavor;
1711                 if (!args->nfs_server.hostname)
1712                         goto out_nomem;
1713
1714                 /*
1715                  * The legacy version 6 binary mount data from userspace has a
1716                  * field used only to transport selinux information into the
1717                  * the kernel.  To continue to support that functionality we
1718                  * have a touch of selinux knowledge here in the NFS code. The
1719                  * userspace code converted context=blah to just blah so we are
1720                  * converting back to the full string selinux understands.
1721                  */
1722                 if (data->context[0]){
1723 #ifdef CONFIG_SECURITY_SELINUX
1724                         int rc;
1725                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1726                         if (!opts_str)
1727                                 return -ENOMEM;
1728                         strcpy(opts_str, "context=");
1729                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1730                         strcat(opts_str, &data->context[0]);
1731                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1732                         kfree(opts_str);
1733                         if (rc)
1734                                 return rc;
1735 #else
1736                         return -EINVAL;
1737 #endif
1738                 }
1739
1740                 break;
1741         default: {
1742                 int status;
1743
1744                 if (nfs_parse_mount_options((char *)options, args) == 0)
1745                         return -EINVAL;
1746
1747                 if (!nfs_verify_server_address(sap))
1748                         goto out_no_address;
1749
1750                 if (args->version == 4)
1751 #ifdef CONFIG_NFS_V4
1752                         return nfs4_validate_text_mount_data(options,
1753                                                              args, dev_name);
1754 #else
1755                         goto out_v4_not_compiled;
1756 #endif
1757
1758                 nfs_set_default_port(sap, args->nfs_server.port, 0);
1759
1760                 nfs_set_mount_transport_protocol(args);
1761
1762                 status = nfs_parse_devname(dev_name,
1763                                            &args->nfs_server.hostname,
1764                                            PAGE_SIZE,
1765                                            &args->nfs_server.export_path,
1766                                            NFS_MAXPATHLEN);
1767                 if (!status)
1768                         status = nfs_try_mount(args, mntfh);
1769
1770                 kfree(args->nfs_server.export_path);
1771                 args->nfs_server.export_path = NULL;
1772
1773                 if (status)
1774                         return status;
1775
1776                 break;
1777                 }
1778         }
1779
1780 #ifndef CONFIG_NFS_V3
1781         if (args->flags & NFS_MOUNT_VER3)
1782                 goto out_v3_not_compiled;
1783 #endif /* !CONFIG_NFS_V3 */
1784
1785         return 0;
1786
1787 out_no_data:
1788         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1789         return -EINVAL;
1790
1791 out_no_v3:
1792         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1793                  data->version);
1794         return -EINVAL;
1795
1796 out_no_sec:
1797         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1798         return -EINVAL;
1799
1800 #ifndef CONFIG_NFS_V3
1801 out_v3_not_compiled:
1802         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1803         return -EPROTONOSUPPORT;
1804 #endif /* !CONFIG_NFS_V3 */
1805
1806 #ifndef CONFIG_NFS_V4
1807 out_v4_not_compiled:
1808         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1809         return -EPROTONOSUPPORT;
1810 #endif /* !CONFIG_NFS_V4 */
1811
1812 out_nomem:
1813         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1814         return -ENOMEM;
1815
1816 out_no_address:
1817         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1818         return -EINVAL;
1819
1820 out_invalid_fh:
1821         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1822         return -EINVAL;
1823 }
1824
1825 static int
1826 nfs_compare_remount_data(struct nfs_server *nfss,
1827                          struct nfs_parsed_mount_data *data)
1828 {
1829         if (data->flags != nfss->flags ||
1830             data->rsize != nfss->rsize ||
1831             data->wsize != nfss->wsize ||
1832             data->retrans != nfss->client->cl_timeout->to_retries ||
1833             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1834             data->acregmin != nfss->acregmin / HZ ||
1835             data->acregmax != nfss->acregmax / HZ ||
1836             data->acdirmin != nfss->acdirmin / HZ ||
1837             data->acdirmax != nfss->acdirmax / HZ ||
1838             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1839             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1840             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1841                    data->nfs_server.addrlen) != 0)
1842                 return -EINVAL;
1843
1844         return 0;
1845 }
1846
1847 static int
1848 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1849 {
1850         int error;
1851         struct nfs_server *nfss = sb->s_fs_info;
1852         struct nfs_parsed_mount_data *data;
1853         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1854         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1855         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1856
1857         /*
1858          * Userspace mount programs that send binary options generally send
1859          * them populated with default values. We have no way to know which
1860          * ones were explicitly specified. Fall back to legacy behavior and
1861          * just return success.
1862          */
1863         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1864             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1865                                            options->version <= 6))))
1866                 return 0;
1867
1868         data = kzalloc(sizeof(*data), GFP_KERNEL);
1869         if (data == NULL)
1870                 return -ENOMEM;
1871
1872         lock_kernel();
1873         /* fill out struct with values from existing mount */
1874         data->flags = nfss->flags;
1875         data->rsize = nfss->rsize;
1876         data->wsize = nfss->wsize;
1877         data->retrans = nfss->client->cl_timeout->to_retries;
1878         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1879         data->acregmin = nfss->acregmin / HZ;
1880         data->acregmax = nfss->acregmax / HZ;
1881         data->acdirmin = nfss->acdirmin / HZ;
1882         data->acdirmax = nfss->acdirmax / HZ;
1883         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1884         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1885         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1886                 data->nfs_server.addrlen);
1887
1888         /* overwrite those values with any that were specified */
1889         error = nfs_parse_mount_options((char *)options, data);
1890         if (error < 0)
1891                 goto out;
1892
1893         /* compare new mount options with old ones */
1894         error = nfs_compare_remount_data(nfss, data);
1895 out:
1896         kfree(data);
1897         unlock_kernel();
1898         return error;
1899 }
1900
1901 /*
1902  * Initialise the common bits of the superblock
1903  */
1904 static inline void nfs_initialise_sb(struct super_block *sb)
1905 {
1906         struct nfs_server *server = NFS_SB(sb);
1907
1908         sb->s_magic = NFS_SUPER_MAGIC;
1909
1910         /* We probably want something more informative here */
1911         snprintf(sb->s_id, sizeof(sb->s_id),
1912                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1913
1914         if (sb->s_blocksize == 0)
1915                 sb->s_blocksize = nfs_block_bits(server->wsize,
1916                                                  &sb->s_blocksize_bits);
1917
1918         if (server->flags & NFS_MOUNT_NOAC)
1919                 sb->s_flags |= MS_SYNCHRONOUS;
1920
1921         sb->s_bdi = &server->backing_dev_info;
1922
1923         nfs_super_set_maxbytes(sb, server->maxfilesize);
1924 }
1925
1926 /*
1927  * Finish setting up an NFS2/3 superblock
1928  */
1929 static void nfs_fill_super(struct super_block *sb,
1930                            struct nfs_parsed_mount_data *data)
1931 {
1932         struct nfs_server *server = NFS_SB(sb);
1933
1934         sb->s_blocksize_bits = 0;
1935         sb->s_blocksize = 0;
1936         if (data->bsize)
1937                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1938
1939         if (server->flags & NFS_MOUNT_VER3) {
1940                 /* The VFS shouldn't apply the umask to mode bits. We will do
1941                  * so ourselves when necessary.
1942                  */
1943                 sb->s_flags |= MS_POSIXACL;
1944                 sb->s_time_gran = 1;
1945         }
1946
1947         sb->s_op = &nfs_sops;
1948         nfs_initialise_sb(sb);
1949 }
1950
1951 /*
1952  * Finish setting up a cloned NFS2/3 superblock
1953  */
1954 static void nfs_clone_super(struct super_block *sb,
1955                             const struct super_block *old_sb)
1956 {
1957         struct nfs_server *server = NFS_SB(sb);
1958
1959         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1960         sb->s_blocksize = old_sb->s_blocksize;
1961         sb->s_maxbytes = old_sb->s_maxbytes;
1962
1963         if (server->flags & NFS_MOUNT_VER3) {
1964                 /* The VFS shouldn't apply the umask to mode bits. We will do
1965                  * so ourselves when necessary.
1966                  */
1967                 sb->s_flags |= MS_POSIXACL;
1968                 sb->s_time_gran = 1;
1969         }
1970
1971         sb->s_op = old_sb->s_op;
1972         nfs_initialise_sb(sb);
1973 }
1974
1975 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1976 {
1977         const struct nfs_server *a = s->s_fs_info;
1978         const struct rpc_clnt *clnt_a = a->client;
1979         const struct rpc_clnt *clnt_b = b->client;
1980
1981         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1982                 goto Ebusy;
1983         if (a->nfs_client != b->nfs_client)
1984                 goto Ebusy;
1985         if (a->flags != b->flags)
1986                 goto Ebusy;
1987         if (a->wsize != b->wsize)
1988                 goto Ebusy;
1989         if (a->rsize != b->rsize)
1990                 goto Ebusy;
1991         if (a->acregmin != b->acregmin)
1992                 goto Ebusy;
1993         if (a->acregmax != b->acregmax)
1994                 goto Ebusy;
1995         if (a->acdirmin != b->acdirmin)
1996                 goto Ebusy;
1997         if (a->acdirmax != b->acdirmax)
1998                 goto Ebusy;
1999         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2000                 goto Ebusy;
2001         return 1;
2002 Ebusy:
2003         return 0;
2004 }
2005
2006 struct nfs_sb_mountdata {
2007         struct nfs_server *server;
2008         int mntflags;
2009 };
2010
2011 static int nfs_set_super(struct super_block *s, void *data)
2012 {
2013         struct nfs_sb_mountdata *sb_mntdata = data;
2014         struct nfs_server *server = sb_mntdata->server;
2015         int ret;
2016
2017         s->s_flags = sb_mntdata->mntflags;
2018         s->s_fs_info = server;
2019         ret = set_anon_super(s, server);
2020         if (ret == 0)
2021                 server->s_dev = s->s_dev;
2022         return ret;
2023 }
2024
2025 static int nfs_compare_super_address(struct nfs_server *server1,
2026                                      struct nfs_server *server2)
2027 {
2028         struct sockaddr *sap1, *sap2;
2029
2030         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2031         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2032
2033         if (sap1->sa_family != sap2->sa_family)
2034                 return 0;
2035
2036         switch (sap1->sa_family) {
2037         case AF_INET: {
2038                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2039                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2040                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2041                         return 0;
2042                 if (sin1->sin_port != sin2->sin_port)
2043                         return 0;
2044                 break;
2045         }
2046         case AF_INET6: {
2047                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2048                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2049                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2050                         return 0;
2051                 if (sin1->sin6_port != sin2->sin6_port)
2052                         return 0;
2053                 break;
2054         }
2055         default:
2056                 return 0;
2057         }
2058
2059         return 1;
2060 }
2061
2062 static int nfs_compare_super(struct super_block *sb, void *data)
2063 {
2064         struct nfs_sb_mountdata *sb_mntdata = data;
2065         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2066         int mntflags = sb_mntdata->mntflags;
2067
2068         if (!nfs_compare_super_address(old, server))
2069                 return 0;
2070         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2071         if (old->flags & NFS_MOUNT_UNSHARED)
2072                 return 0;
2073         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2074                 return 0;
2075         return nfs_compare_mount_options(sb, server, mntflags);
2076 }
2077
2078 static int nfs_bdi_register(struct nfs_server *server)
2079 {
2080         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2081 }
2082
2083 static int nfs_get_sb(struct file_system_type *fs_type,
2084         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2085 {
2086         struct nfs_server *server = NULL;
2087         struct super_block *s;
2088         struct nfs_parsed_mount_data *data;
2089         struct nfs_fh *mntfh;
2090         struct dentry *mntroot;
2091         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2092         struct nfs_sb_mountdata sb_mntdata = {
2093                 .mntflags = flags,
2094         };
2095         int error = -ENOMEM;
2096
2097         data = kzalloc(sizeof(*data), GFP_KERNEL);
2098         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2099         if (data == NULL || mntfh == NULL)
2100                 goto out_free_fh;
2101
2102         security_init_mnt_opts(&data->lsm_opts);
2103
2104         /* Validate the mount data */
2105         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2106         if (error < 0)
2107                 goto out;
2108
2109 #ifdef CONFIG_NFS_V4
2110         if (data->version == 4) {
2111                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2112                 kfree(data->client_address);
2113                 goto out;
2114         }
2115 #endif  /* CONFIG_NFS_V4 */
2116
2117         /* Get a volume representation */
2118         server = nfs_create_server(data, mntfh);
2119         if (IS_ERR(server)) {
2120                 error = PTR_ERR(server);
2121                 goto out;
2122         }
2123         sb_mntdata.server = server;
2124
2125         if (server->flags & NFS_MOUNT_UNSHARED)
2126                 compare_super = NULL;
2127
2128         /* Get a superblock - note that we may end up sharing one that already exists */
2129         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2130         if (IS_ERR(s)) {
2131                 error = PTR_ERR(s);
2132                 goto out_err_nosb;
2133         }
2134
2135         if (s->s_fs_info != server) {
2136                 nfs_free_server(server);
2137                 server = NULL;
2138         } else {
2139                 error = nfs_bdi_register(server);
2140                 if (error)
2141                         goto error_splat_super;
2142         }
2143
2144         if (!s->s_root) {
2145                 /* initial superblock/root creation */
2146                 nfs_fill_super(s, data);
2147                 nfs_fscache_get_super_cookie(s, data);
2148         }
2149
2150         mntroot = nfs_get_root(s, mntfh);
2151         if (IS_ERR(mntroot)) {
2152                 error = PTR_ERR(mntroot);
2153                 goto error_splat_super;
2154         }
2155
2156         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2157         if (error)
2158                 goto error_splat_root;
2159
2160         s->s_flags |= MS_ACTIVE;
2161         mnt->mnt_sb = s;
2162         mnt->mnt_root = mntroot;
2163         error = 0;
2164
2165 out:
2166         kfree(data->nfs_server.hostname);
2167         kfree(data->mount_server.hostname);
2168         kfree(data->fscache_uniq);
2169         security_free_mnt_opts(&data->lsm_opts);
2170 out_free_fh:
2171         kfree(mntfh);
2172         kfree(data);
2173         return error;
2174
2175 out_err_nosb:
2176         nfs_free_server(server);
2177         goto out;
2178
2179 error_splat_root:
2180         dput(mntroot);
2181 error_splat_super:
2182         deactivate_locked_super(s);
2183         goto out;
2184 }
2185
2186 /*
2187  * Destroy an NFS2/3 superblock
2188  */
2189 static void nfs_kill_super(struct super_block *s)
2190 {
2191         struct nfs_server *server = NFS_SB(s);
2192
2193         kill_anon_super(s);
2194         bdi_unregister(&server->backing_dev_info);
2195         nfs_fscache_release_super_cookie(s);
2196         nfs_free_server(server);
2197 }
2198
2199 /*
2200  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2201  */
2202 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2203                            const char *dev_name, void *raw_data,
2204                            struct vfsmount *mnt)
2205 {
2206         struct nfs_clone_mount *data = raw_data;
2207         struct super_block *s;
2208         struct nfs_server *server;
2209         struct dentry *mntroot;
2210         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2211         struct nfs_sb_mountdata sb_mntdata = {
2212                 .mntflags = flags,
2213         };
2214         int error;
2215
2216         dprintk("--> nfs_xdev_get_sb()\n");
2217
2218         /* create a new volume representation */
2219         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2220         if (IS_ERR(server)) {
2221                 error = PTR_ERR(server);
2222                 goto out_err_noserver;
2223         }
2224         sb_mntdata.server = server;
2225
2226         if (server->flags & NFS_MOUNT_UNSHARED)
2227                 compare_super = NULL;
2228
2229         /* Get a superblock - note that we may end up sharing one that already exists */
2230         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2231         if (IS_ERR(s)) {
2232                 error = PTR_ERR(s);
2233                 goto out_err_nosb;
2234         }
2235
2236         if (s->s_fs_info != server) {
2237                 nfs_free_server(server);
2238                 server = NULL;
2239         } else {
2240                 error = nfs_bdi_register(server);
2241                 if (error)
2242                         goto error_splat_super;
2243         }
2244
2245         if (!s->s_root) {
2246                 /* initial superblock/root creation */
2247                 nfs_clone_super(s, data->sb);
2248         }
2249
2250         mntroot = nfs_get_root(s, data->fh);
2251         if (IS_ERR(mntroot)) {
2252                 error = PTR_ERR(mntroot);
2253                 goto error_splat_super;
2254         }
2255         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2256                 dput(mntroot);
2257                 error = -ESTALE;
2258                 goto error_splat_super;
2259         }
2260
2261         s->s_flags |= MS_ACTIVE;
2262         mnt->mnt_sb = s;
2263         mnt->mnt_root = mntroot;
2264
2265         /* clone any lsm security options from the parent to the new sb */
2266         security_sb_clone_mnt_opts(data->sb, s);
2267
2268         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2269         return 0;
2270
2271 out_err_nosb:
2272         nfs_free_server(server);
2273 out_err_noserver:
2274         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2275         return error;
2276
2277 error_splat_super:
2278         deactivate_locked_super(s);
2279         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2280         return error;
2281 }
2282
2283 #ifdef CONFIG_NFS_V4
2284
2285 /*
2286  * Finish setting up a cloned NFS4 superblock
2287  */
2288 static void nfs4_clone_super(struct super_block *sb,
2289                             const struct super_block *old_sb)
2290 {
2291         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2292         sb->s_blocksize = old_sb->s_blocksize;
2293         sb->s_maxbytes = old_sb->s_maxbytes;
2294         sb->s_time_gran = 1;
2295         sb->s_op = old_sb->s_op;
2296         nfs_initialise_sb(sb);
2297 }
2298
2299 /*
2300  * Set up an NFS4 superblock
2301  */
2302 static void nfs4_fill_super(struct super_block *sb)
2303 {
2304         sb->s_time_gran = 1;
2305         sb->s_op = &nfs4_sops;
2306         nfs_initialise_sb(sb);
2307 }
2308
2309 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2310 {
2311         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2312 }
2313
2314 static int nfs4_validate_text_mount_data(void *options,
2315                                          struct nfs_parsed_mount_data *args,
2316                                          const char *dev_name)
2317 {
2318         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2319
2320         nfs_set_default_port(sap, args->nfs_server.port, NFS_PORT);
2321
2322         nfs_validate_transport_protocol(args);
2323
2324         nfs4_validate_mount_flags(args);
2325
2326         if (args->version != 4) {
2327                 dfprintk(MOUNT,
2328                          "NFS4: Illegal mount version\n");
2329                 return -EINVAL;
2330         }
2331
2332         if (args->auth_flavor_len > 1) {
2333                 dfprintk(MOUNT,
2334                          "NFS4: Too many RPC auth flavours specified\n");
2335                 return -EINVAL;
2336         }
2337
2338         if (args->client_address == NULL) {
2339                 dfprintk(MOUNT,
2340                          "NFS4: mount program didn't pass callback address\n");
2341                 return -EINVAL;
2342         }
2343
2344         return nfs_parse_devname(dev_name,
2345                                    &args->nfs_server.hostname,
2346                                    NFS4_MAXNAMLEN,
2347                                    &args->nfs_server.export_path,
2348                                    NFS4_MAXPATHLEN);
2349 }
2350
2351 /*
2352  * Validate NFSv4 mount options
2353  */
2354 static int nfs4_validate_mount_data(void *options,
2355                                     struct nfs_parsed_mount_data *args,
2356                                     const char *dev_name)
2357 {
2358         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2359         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2360         char *c;
2361
2362         if (data == NULL)
2363                 goto out_no_data;
2364
2365         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2366         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2367         args->acregmin          = NFS_DEF_ACREGMIN;
2368         args->acregmax          = NFS_DEF_ACREGMAX;
2369         args->acdirmin          = NFS_DEF_ACDIRMIN;
2370         args->acdirmax          = NFS_DEF_ACDIRMAX;
2371         args->nfs_server.port   = NFS_UNSPEC_PORT;
2372         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2373         args->auth_flavor_len   = 1;
2374         args->version           = 4;
2375         args->minorversion      = 0;
2376
2377         switch (data->version) {
2378         case 1:
2379                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2380                         goto out_no_address;
2381                 if (data->host_addrlen == 0)
2382                         goto out_no_address;
2383                 args->nfs_server.addrlen = data->host_addrlen;
2384                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2385                         return -EFAULT;
2386                 if (!nfs_verify_server_address(sap))
2387                         goto out_no_address;
2388
2389                 if (data->auth_flavourlen) {
2390                         if (data->auth_flavourlen > 1)
2391                                 goto out_inval_auth;
2392                         if (copy_from_user(&args->auth_flavors[0],
2393                                            data->auth_flavours,
2394                                            sizeof(args->auth_flavors[0])))
2395                                 return -EFAULT;
2396                 }
2397
2398                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2399                 if (IS_ERR(c))
2400                         return PTR_ERR(c);
2401                 args->nfs_server.hostname = c;
2402
2403                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2404                 if (IS_ERR(c))
2405                         return PTR_ERR(c);
2406                 args->nfs_server.export_path = c;
2407                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2408
2409                 c = strndup_user(data->client_addr.data, 16);
2410                 if (IS_ERR(c))
2411                         return PTR_ERR(c);
2412                 args->client_address = c;
2413
2414                 /*
2415                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2416                  * can deal with.
2417                  */
2418
2419                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2420                 args->rsize     = data->rsize;
2421                 args->wsize     = data->wsize;
2422                 args->timeo     = data->timeo;
2423                 args->retrans   = data->retrans;
2424                 args->acregmin  = data->acregmin;
2425                 args->acregmax  = data->acregmax;
2426                 args->acdirmin  = data->acdirmin;
2427                 args->acdirmax  = data->acdirmax;
2428                 args->nfs_server.protocol = data->proto;
2429                 nfs_validate_transport_protocol(args);
2430
2431                 break;
2432         default:
2433                 if (nfs_parse_mount_options((char *)options, args) == 0)
2434                         return -EINVAL;
2435
2436                 if (!nfs_verify_server_address(sap))
2437                         return -EINVAL;
2438
2439                 return nfs4_validate_text_mount_data(options, args, dev_name);
2440         }
2441
2442         return 0;
2443
2444 out_no_data:
2445         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2446         return -EINVAL;
2447
2448 out_inval_auth:
2449         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2450                  data->auth_flavourlen);
2451         return -EINVAL;
2452
2453 out_no_address:
2454         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2455         return -EINVAL;
2456 }
2457
2458 /*
2459  * Get the superblock for the NFS4 root partition
2460  */
2461 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2462         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2463 {
2464         struct nfs_parsed_mount_data *data = raw_data;
2465         struct super_block *s;
2466         struct nfs_server *server;
2467         struct nfs_fh *mntfh;
2468         struct dentry *mntroot;
2469         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2470         struct nfs_sb_mountdata sb_mntdata = {
2471                 .mntflags = flags,
2472         };
2473         int error = -ENOMEM;
2474
2475         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2476         if (data == NULL || mntfh == NULL)
2477                 goto out_free_fh;
2478
2479         security_init_mnt_opts(&data->lsm_opts);
2480
2481         /* Get a volume representation */
2482         server = nfs4_create_server(data, mntfh);
2483         if (IS_ERR(server)) {
2484                 error = PTR_ERR(server);
2485                 goto out;
2486         }
2487         sb_mntdata.server = server;
2488
2489         if (server->flags & NFS4_MOUNT_UNSHARED)
2490                 compare_super = NULL;
2491
2492         /* Get a superblock - note that we may end up sharing one that already exists */
2493         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2494         if (IS_ERR(s)) {
2495                 error = PTR_ERR(s);
2496                 goto out_free;
2497         }
2498
2499         if (s->s_fs_info != server) {
2500                 nfs_free_server(server);
2501                 server = NULL;
2502         } else {
2503                 error = nfs_bdi_register(server);
2504                 if (error)
2505                         goto error_splat_super;
2506         }
2507
2508         if (!s->s_root) {
2509                 /* initial superblock/root creation */
2510                 nfs4_fill_super(s);
2511                 nfs_fscache_get_super_cookie(s, data);
2512         }
2513
2514         mntroot = nfs4_get_root(s, mntfh);
2515         if (IS_ERR(mntroot)) {
2516                 error = PTR_ERR(mntroot);
2517                 goto error_splat_super;
2518         }
2519
2520         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2521         if (error)
2522                 goto error_splat_root;
2523
2524         s->s_flags |= MS_ACTIVE;
2525         mnt->mnt_sb = s;
2526         mnt->mnt_root = mntroot;
2527         error = 0;
2528
2529 out:
2530         security_free_mnt_opts(&data->lsm_opts);
2531 out_free_fh:
2532         kfree(mntfh);
2533         return error;
2534
2535 out_free:
2536         nfs_free_server(server);
2537         goto out;
2538
2539 error_splat_root:
2540         dput(mntroot);
2541 error_splat_super:
2542         deactivate_locked_super(s);
2543         goto out;
2544 }
2545
2546 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2547                 int flags, void *data, const char *hostname)
2548 {
2549         struct vfsmount *root_mnt;
2550         char *root_devname;
2551         size_t len;
2552
2553         len = strlen(hostname) + 3;
2554         root_devname = kmalloc(len, GFP_KERNEL);
2555         if (root_devname == NULL)
2556                 return ERR_PTR(-ENOMEM);
2557         snprintf(root_devname, len, "%s:/", hostname);
2558         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2559         kfree(root_devname);
2560         return root_mnt;
2561 }
2562
2563 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2564 {
2565         char *page = (char *) __get_free_page(GFP_KERNEL);
2566         char *devname, *tmp;
2567
2568         if (page == NULL)
2569                 return;
2570         devname = nfs_path(path->mnt->mnt_devname,
2571                         path->mnt->mnt_root, path->dentry,
2572                         page, PAGE_SIZE);
2573         if (devname == NULL)
2574                 goto out_freepage;
2575         tmp = kstrdup(devname, GFP_KERNEL);
2576         if (tmp == NULL)
2577                 goto out_freepage;
2578         kfree(mnt->mnt_devname);
2579         mnt->mnt_devname = tmp;
2580 out_freepage:
2581         free_page((unsigned long)page);
2582 }
2583
2584 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2585                 const char *export_path, struct vfsmount *mnt_target)
2586 {
2587         struct mnt_namespace *ns_private;
2588         struct nameidata nd;
2589         struct super_block *s;
2590         int ret;
2591
2592         ns_private = create_mnt_ns(root_mnt);
2593         ret = PTR_ERR(ns_private);
2594         if (IS_ERR(ns_private))
2595                 goto out_mntput;
2596
2597         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2598                         export_path, LOOKUP_FOLLOW, &nd);
2599
2600         put_mnt_ns(ns_private);
2601
2602         if (ret != 0)
2603                 goto out_err;
2604
2605         s = nd.path.mnt->mnt_sb;
2606         atomic_inc(&s->s_active);
2607         mnt_target->mnt_sb = s;
2608         mnt_target->mnt_root = dget(nd.path.dentry);
2609
2610         /* Correct the device pathname */
2611         nfs_fix_devname(&nd.path, mnt_target);
2612
2613         path_put(&nd.path);
2614         down_write(&s->s_umount);
2615         return 0;
2616 out_mntput:
2617         mntput(root_mnt);
2618 out_err:
2619         return ret;
2620 }
2621
2622 static int nfs4_try_mount(int flags, const char *dev_name,
2623                          struct nfs_parsed_mount_data *data,
2624                          struct vfsmount *mnt)
2625 {
2626         char *export_path;
2627         struct vfsmount *root_mnt;
2628         int error;
2629
2630         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2631
2632         export_path = data->nfs_server.export_path;
2633         data->nfs_server.export_path = "/";
2634         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2635                         data->nfs_server.hostname);
2636         data->nfs_server.export_path = export_path;
2637
2638         error = PTR_ERR(root_mnt);
2639         if (IS_ERR(root_mnt))
2640                 goto out;
2641
2642         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2643
2644 out:
2645         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2646                         error != 0 ? " [error]" : "");
2647         return error;
2648 }
2649
2650 /*
2651  * Get the superblock for an NFS4 mountpoint
2652  */
2653 static int nfs4_get_sb(struct file_system_type *fs_type,
2654         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2655 {
2656         struct nfs_parsed_mount_data *data;
2657         int error = -ENOMEM;
2658
2659         data = kzalloc(sizeof(*data), GFP_KERNEL);
2660         if (data == NULL)
2661                 goto out_free_data;
2662
2663         /* Validate the mount data */
2664         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2665         if (error < 0)
2666                 goto out;
2667
2668         error = nfs4_try_mount(flags, dev_name, data, mnt);
2669
2670 out:
2671         kfree(data->client_address);
2672         kfree(data->nfs_server.export_path);
2673         kfree(data->nfs_server.hostname);
2674         kfree(data->fscache_uniq);
2675 out_free_data:
2676         kfree(data);
2677         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2678                         error != 0 ? " [error]" : "");
2679         return error;
2680 }
2681
2682 static void nfs4_kill_super(struct super_block *sb)
2683 {
2684         struct nfs_server *server = NFS_SB(sb);
2685
2686         dprintk("--> %s\n", __func__);
2687         nfs_super_return_all_delegations(sb);
2688         kill_anon_super(sb);
2689         nfs4_renewd_prepare_shutdown(server);
2690         nfs_fscache_release_super_cookie(sb);
2691         nfs_free_server(server);
2692         dprintk("<-- %s\n", __func__);
2693 }
2694
2695 /*
2696  * Clone an NFS4 server record on xdev traversal (FSID-change)
2697  */
2698 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2699                             const char *dev_name, void *raw_data,
2700                             struct vfsmount *mnt)
2701 {
2702         struct nfs_clone_mount *data = raw_data;
2703         struct super_block *s;
2704         struct nfs_server *server;
2705         struct dentry *mntroot;
2706         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2707         struct nfs_sb_mountdata sb_mntdata = {
2708                 .mntflags = flags,
2709         };
2710         int error;
2711
2712         dprintk("--> nfs4_xdev_get_sb()\n");
2713
2714         /* create a new volume representation */
2715         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2716         if (IS_ERR(server)) {
2717                 error = PTR_ERR(server);
2718                 goto out_err_noserver;
2719         }
2720         sb_mntdata.server = server;
2721
2722         if (server->flags & NFS4_MOUNT_UNSHARED)
2723                 compare_super = NULL;
2724
2725         /* Get a superblock - note that we may end up sharing one that already exists */
2726         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2727         if (IS_ERR(s)) {
2728                 error = PTR_ERR(s);
2729                 goto out_err_nosb;
2730         }
2731
2732         if (s->s_fs_info != server) {
2733                 nfs_free_server(server);
2734                 server = NULL;
2735         } else {
2736                 error = nfs_bdi_register(server);
2737                 if (error)
2738                         goto error_splat_super;
2739         }
2740
2741         if (!s->s_root) {
2742                 /* initial superblock/root creation */
2743                 nfs4_clone_super(s, data->sb);
2744         }
2745
2746         mntroot = nfs4_get_root(s, data->fh);
2747         if (IS_ERR(mntroot)) {
2748                 error = PTR_ERR(mntroot);
2749                 goto error_splat_super;
2750         }
2751         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2752                 dput(mntroot);
2753                 error = -ESTALE;
2754                 goto error_splat_super;
2755         }
2756
2757         s->s_flags |= MS_ACTIVE;
2758         mnt->mnt_sb = s;
2759         mnt->mnt_root = mntroot;
2760
2761         security_sb_clone_mnt_opts(data->sb, s);
2762
2763         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2764         return 0;
2765
2766 out_err_nosb:
2767         nfs_free_server(server);
2768 out_err_noserver:
2769         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2770         return error;
2771
2772 error_splat_super:
2773         deactivate_locked_super(s);
2774         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2775         return error;
2776 }
2777
2778 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2779                 int flags, const char *dev_name, void *raw_data,
2780                 struct vfsmount *mnt)
2781 {
2782         struct nfs_clone_mount *data = raw_data;
2783         struct super_block *s;
2784         struct nfs_server *server;
2785         struct dentry *mntroot;
2786         struct nfs_fh mntfh;
2787         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2788         struct nfs_sb_mountdata sb_mntdata = {
2789                 .mntflags = flags,
2790         };
2791         int error;
2792
2793         dprintk("--> nfs4_referral_get_sb()\n");
2794
2795         /* create a new volume representation */
2796         server = nfs4_create_referral_server(data, &mntfh);
2797         if (IS_ERR(server)) {
2798                 error = PTR_ERR(server);
2799                 goto out_err_noserver;
2800         }
2801         sb_mntdata.server = server;
2802
2803         if (server->flags & NFS4_MOUNT_UNSHARED)
2804                 compare_super = NULL;
2805
2806         /* Get a superblock - note that we may end up sharing one that already exists */
2807         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2808         if (IS_ERR(s)) {
2809                 error = PTR_ERR(s);
2810                 goto out_err_nosb;
2811         }
2812
2813         if (s->s_fs_info != server) {
2814                 nfs_free_server(server);
2815                 server = NULL;
2816         } else {
2817                 error = nfs_bdi_register(server);
2818                 if (error)
2819                         goto error_splat_super;
2820         }
2821
2822         if (!s->s_root) {
2823                 /* initial superblock/root creation */
2824                 nfs4_fill_super(s);
2825         }
2826
2827         mntroot = nfs4_get_root(s, &mntfh);
2828         if (IS_ERR(mntroot)) {
2829                 error = PTR_ERR(mntroot);
2830                 goto error_splat_super;
2831         }
2832         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2833                 dput(mntroot);
2834                 error = -ESTALE;
2835                 goto error_splat_super;
2836         }
2837
2838         s->s_flags |= MS_ACTIVE;
2839         mnt->mnt_sb = s;
2840         mnt->mnt_root = mntroot;
2841
2842         security_sb_clone_mnt_opts(data->sb, s);
2843
2844         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2845         return 0;
2846
2847 out_err_nosb:
2848         nfs_free_server(server);
2849 out_err_noserver:
2850         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2851         return error;
2852
2853 error_splat_super:
2854         deactivate_locked_super(s);
2855         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2856         return error;
2857 }
2858
2859 /*
2860  * Create an NFS4 server record on referral traversal
2861  */
2862 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2863                 int flags, const char *dev_name, void *raw_data,
2864                 struct vfsmount *mnt)
2865 {
2866         struct nfs_clone_mount *data = raw_data;
2867         char *export_path;
2868         struct vfsmount *root_mnt;
2869         int error;
2870
2871         dprintk("--> nfs4_referral_get_sb()\n");
2872
2873         export_path = data->mnt_path;
2874         data->mnt_path = "/";
2875
2876         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2877                         flags, data, data->hostname);
2878         data->mnt_path = export_path;
2879
2880         error = PTR_ERR(root_mnt);
2881         if (IS_ERR(root_mnt))
2882                 goto out;
2883
2884         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2885 out:
2886         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2887                         error != 0 ? " [error]" : "");
2888         return error;
2889 }
2890
2891 #endif /* CONFIG_NFS_V4 */