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   1 /*
   2  *  linux/fs/nfs/super.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  *  Split from inode.c by David Howells <dhowells@redhat.com>
  15  *
  16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17  *   particular server are held in the same superblock
  18  * - NFS superblocks can have several effective roots to the dentry tree
  19  * - directory type roots are spliced into the tree when a path from one root reaches the root
  20  *   of another (see nfs_lookup())
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/time.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/unistd.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/stats.h>
  35 #include <linux/sunrpc/metrics.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/sunrpc/xprtrdma.h>
  38 #include <linux/nfs_fs.h>
  39 #include <linux/nfs_mount.h>
  40 #include <linux/nfs4_mount.h>
  41 #include <linux/lockd/bind.h>
  42 #include <linux/smp_lock.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/mnt_namespace.h>
  46 #include <linux/namei.h>
  47 #include <linux/nfs_idmap.h>
  48 #include <linux/vfs.h>
  49 #include <linux/inet.h>
  50 #include <linux/in6.h>
  51 #include <net/ipv6.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/nfs_xdr.h>
  54 #include <linux/magic.h>
  55 #include <linux/parser.h>
  56
  57 #include <asm/system.h>
  58 #include <asm/uaccess.h>
  59
  60 #include "nfs4_fs.h"
  61 #include "callback.h"
  62 #include "delegation.h"
  63 #include "iostat.h"
  64 #include "internal.h"
  65 #include "fscache.h"
  66
  67 #define NFSDBG_FACILITY         NFSDBG_VFS
  68
  69 enum {
  70         /* Mount options that take no arguments */
  71         Opt_soft, Opt_hard,
  72         Opt_posix, Opt_noposix,
  73         Opt_cto, Opt_nocto,
  74         Opt_ac, Opt_noac,
  75         Opt_lock, Opt_nolock,
  76         Opt_v2, Opt_v3, Opt_v4,
  77         Opt_udp, Opt_tcp, Opt_rdma,
  78         Opt_acl, Opt_noacl,
  79         Opt_rdirplus, Opt_nordirplus,
  80         Opt_sharecache, Opt_nosharecache,
  81         Opt_resvport, Opt_noresvport,
  82         Opt_fscache, Opt_nofscache,
  83
  84         /* Mount options that take integer arguments */
  85         Opt_port,
  86         Opt_rsize, Opt_wsize, Opt_bsize,
  87         Opt_timeo, Opt_retrans,
  88         Opt_acregmin, Opt_acregmax,
  89         Opt_acdirmin, Opt_acdirmax,
  90         Opt_actimeo,
  91         Opt_namelen,
  92         Opt_mountport,
  93         Opt_mountvers,
  94         Opt_nfsvers,
  95         Opt_minorversion,
  96
  97         /* Mount options that take string arguments */
  98         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
  99         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 100         Opt_lookupcache,
 101         Opt_fscache_uniq,
 102
 103         /* Special mount options */
 104         Opt_userspace, Opt_deprecated, Opt_sloppy,
 105
 106         Opt_err
 107 };
 108
 109 static const match_table_t nfs_mount_option_tokens = {
 110         { Opt_userspace, "bg" },
 111         { Opt_userspace, "fg" },
 112         { Opt_userspace, "retry=%s" },
 113
 114         { Opt_sloppy, "sloppy" },
 115
 116         { Opt_soft, "soft" },
 117         { Opt_hard, "hard" },
 118         { Opt_deprecated, "intr" },
 119         { Opt_deprecated, "nointr" },
 120         { Opt_posix, "posix" },
 121         { Opt_noposix, "noposix" },
 122         { Opt_cto, "cto" },
 123         { Opt_nocto, "nocto" },
 124         { Opt_ac, "ac" },
 125         { Opt_noac, "noac" },
 126         { Opt_lock, "lock" },
 127         { Opt_nolock, "nolock" },
 128         { Opt_v2, "v2" },
 129         { Opt_v3, "v3" },
 130         { Opt_v4, "v4" },
 131         { Opt_udp, "udp" },
 132         { Opt_tcp, "tcp" },
 133         { Opt_rdma, "rdma" },
 134         { Opt_acl, "acl" },
 135         { Opt_noacl, "noacl" },
 136         { Opt_rdirplus, "rdirplus" },
 137         { Opt_nordirplus, "nordirplus" },
 138         { Opt_sharecache, "sharecache" },
 139         { Opt_nosharecache, "nosharecache" },
 140         { Opt_resvport, "resvport" },
 141         { Opt_noresvport, "noresvport" },
 142         { Opt_fscache, "fsc" },
 143         { Opt_fscache_uniq, "fsc=%s" },
 144         { Opt_nofscache, "nofsc" },
 145
 146         { Opt_port, "port=%s" },
 147         { Opt_rsize, "rsize=%s" },
 148         { Opt_wsize, "wsize=%s" },
 149         { Opt_bsize, "bsize=%s" },
 150         { Opt_timeo, "timeo=%s" },
 151         { Opt_retrans, "retrans=%s" },
 152         { Opt_acregmin, "acregmin=%s" },
 153         { Opt_acregmax, "acregmax=%s" },
 154         { Opt_acdirmin, "acdirmin=%s" },
 155         { Opt_acdirmax, "acdirmax=%s" },
 156         { Opt_actimeo, "actimeo=%s" },
 157         { Opt_namelen, "namlen=%s" },
 158         { Opt_mountport, "mountport=%s" },
 159         { Opt_mountvers, "mountvers=%s" },
 160         { Opt_nfsvers, "nfsvers=%s" },
 161         { Opt_nfsvers, "vers=%s" },
 162         { Opt_minorversion, "minorversion=%s" },
 163
 164         { Opt_sec, "sec=%s" },
 165         { Opt_proto, "proto=%s" },
 166         { Opt_mountproto, "mountproto=%s" },
 167         { Opt_addr, "addr=%s" },
 168         { Opt_clientaddr, "clientaddr=%s" },
 169         { Opt_mounthost, "mounthost=%s" },
 170         { Opt_mountaddr, "mountaddr=%s" },
 171
 172         { Opt_lookupcache, "lookupcache=%s" },
 173
 174         { Opt_err, NULL }
 175 };
 176
 177 enum {
 178         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
 179
 180         Opt_xprt_err
 181 };
 182
 183 static const match_table_t nfs_xprt_protocol_tokens = {
 184         { Opt_xprt_udp, "udp" },
 185         { Opt_xprt_tcp, "tcp" },
 186         { Opt_xprt_rdma, "rdma" },
 187
 188         { Opt_xprt_err, NULL }
 189 };
 190
 191 enum {
 192         Opt_sec_none, Opt_sec_sys,
 193         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 194         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 195         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 196
 197         Opt_sec_err
 198 };
 199
 200 static const match_table_t nfs_secflavor_tokens = {
 201         { Opt_sec_none, "none" },
 202         { Opt_sec_none, "null" },
 203         { Opt_sec_sys, "sys" },
 204
 205         { Opt_sec_krb5, "krb5" },
 206         { Opt_sec_krb5i, "krb5i" },
 207         { Opt_sec_krb5p, "krb5p" },
 208
 209         { Opt_sec_lkey, "lkey" },
 210         { Opt_sec_lkeyi, "lkeyi" },
 211         { Opt_sec_lkeyp, "lkeyp" },
 212
 213         { Opt_sec_spkm, "spkm3" },
 214         { Opt_sec_spkmi, "spkm3i" },
 215         { Opt_sec_spkmp, "spkm3p" },
 216
 217         { Opt_sec_err, NULL }
 218 };
 219
 220 enum {
 221         Opt_lookupcache_all, Opt_lookupcache_positive,
 222         Opt_lookupcache_none,
 223
 224         Opt_lookupcache_err
 225 };
 226
 227 static match_table_t nfs_lookupcache_tokens = {
 228         { Opt_lookupcache_all, "all" },
 229         { Opt_lookupcache_positive, "pos" },
 230         { Opt_lookupcache_positive, "positive" },
 231         { Opt_lookupcache_none, "none" },
 232
 233         { Opt_lookupcache_err, NULL }
 234 };
 235
 236
 237 static void nfs_umount_begin(struct super_block *);
 238 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 239 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 240 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 241 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 242 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
 243                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 244 static void nfs_kill_super(struct super_block *);
 245 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 246
 247 static struct file_system_type nfs_fs_type = {
 248         .owner          = THIS_MODULE,
 249         .name           = "nfs",
 250         .get_sb         = nfs_get_sb,
 251         .kill_sb        = nfs_kill_super,
 252         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 253 };
 254
 255 struct file_system_type nfs_xdev_fs_type = {
 256         .owner          = THIS_MODULE,
 257         .name           = "nfs",
 258         .get_sb         = nfs_xdev_get_sb,
 259         .kill_sb        = nfs_kill_super,
 260         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 261 };
 262
 263 static const struct super_operations nfs_sops = {
 264         .alloc_inode    = nfs_alloc_inode,
 265         .destroy_inode  = nfs_destroy_inode,
 266         .write_inode    = nfs_write_inode,
 267         .statfs         = nfs_statfs,
 268         .clear_inode    = nfs_clear_inode,
 269         .umount_begin   = nfs_umount_begin,
 270         .show_options   = nfs_show_options,
 271         .show_stats     = nfs_show_stats,
 272         .remount_fs     = nfs_remount,
 273 };
 274
 275 #ifdef CONFIG_NFS_V4
 276 static int nfs4_validate_text_mount_data(void *options,
 277         struct nfs_parsed_mount_data *args, const char *dev_name);
 278 static int nfs4_try_mount(int flags, const char *dev_name,
 279         struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
 280 static int nfs4_get_sb(struct file_system_type *fs_type,
 281         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 282 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 283         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 284 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 285         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 286 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 287         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 288 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
 289         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 290 static void nfs4_kill_super(struct super_block *sb);
 291
 292 static struct file_system_type nfs4_fs_type = {
 293         .owner          = THIS_MODULE,
 294         .name           = "nfs4",
 295         .get_sb         = nfs4_get_sb,
 296         .kill_sb        = nfs4_kill_super,
 297         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 298 };
 299
 300 static struct file_system_type nfs4_remote_fs_type = {
 301         .owner          = THIS_MODULE,
 302         .name           = "nfs4",
 303         .get_sb         = nfs4_remote_get_sb,
 304         .kill_sb        = nfs4_kill_super,
 305         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 306 };
 307
 308 struct file_system_type nfs4_xdev_fs_type = {
 309         .owner          = THIS_MODULE,
 310         .name           = "nfs4",
 311         .get_sb         = nfs4_xdev_get_sb,
 312         .kill_sb        = nfs4_kill_super,
 313         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 314 };
 315
 316 static struct file_system_type nfs4_remote_referral_fs_type = {
 317         .owner          = THIS_MODULE,
 318         .name           = "nfs4",
 319         .get_sb         = nfs4_remote_referral_get_sb,
 320         .kill_sb        = nfs4_kill_super,
 321         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 322 };
 323
 324 struct file_system_type nfs4_referral_fs_type = {
 325         .owner          = THIS_MODULE,
 326         .name           = "nfs4",
 327         .get_sb         = nfs4_referral_get_sb,
 328         .kill_sb        = nfs4_kill_super,
 329         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 330 };
 331
 332 static const struct super_operations nfs4_sops = {
 333         .alloc_inode    = nfs_alloc_inode,
 334         .destroy_inode  = nfs_destroy_inode,
 335         .write_inode    = nfs_write_inode,
 336         .statfs         = nfs_statfs,
 337         .clear_inode    = nfs4_clear_inode,
 338         .umount_begin   = nfs_umount_begin,
 339         .show_options   = nfs_show_options,
 340         .show_stats     = nfs_show_stats,
 341         .remount_fs     = nfs_remount,
 342 };
 343 #endif
 344
 345 static struct shrinker acl_shrinker = {
 346         .shrink         = nfs_access_cache_shrinker,
 347         .seeks          = DEFAULT_SEEKS,
 348 };
 349
 350 /*
 351  * Register the NFS filesystems
 352  */
 353 int __init register_nfs_fs(void)
 354 {
 355         int ret;
 356
 357         ret = register_filesystem(&nfs_fs_type);
 358         if (ret < 0)
 359                 goto error_0;
 360
 361         ret = nfs_register_sysctl();
 362         if (ret < 0)
 363                 goto error_1;
 364 #ifdef CONFIG_NFS_V4
 365         ret = register_filesystem(&nfs4_fs_type);
 366         if (ret < 0)
 367                 goto error_2;
 368 #endif
 369         register_shrinker(&acl_shrinker);
 370         return 0;
 371
 372 #ifdef CONFIG_NFS_V4
 373 error_2:
 374         nfs_unregister_sysctl();
 375 #endif
 376 error_1:
 377         unregister_filesystem(&nfs_fs_type);
 378 error_0:
 379         return ret;
 380 }
 381
 382 /*
 383  * Unregister the NFS filesystems
 384  */
 385 void __exit unregister_nfs_fs(void)
 386 {
 387         unregister_shrinker(&acl_shrinker);
 388 #ifdef CONFIG_NFS_V4
 389         unregister_filesystem(&nfs4_fs_type);
 390 #endif
 391         nfs_unregister_sysctl();
 392         unregister_filesystem(&nfs_fs_type);
 393 }
 394
 395 void nfs_sb_active(struct super_block *sb)
 396 {
 397         struct nfs_server *server = NFS_SB(sb);
 398
 399         if (atomic_inc_return(&server->active) == 1)
 400                 atomic_inc(&sb->s_active);
 401 }
 402
 403 void nfs_sb_deactive(struct super_block *sb)
 404 {
 405         struct nfs_server *server = NFS_SB(sb);
 406
 407         if (atomic_dec_and_test(&server->active))
 408                 deactivate_super(sb);
 409 }
 410
 411 /*
 412  * Deliver file system statistics to userspace
 413  */
 414 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 415 {
 416         struct nfs_server *server = NFS_SB(dentry->d_sb);
 417         unsigned char blockbits;
 418         unsigned long blockres;
 419         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 420         struct nfs_fattr fattr;
 421         struct nfs_fsstat res = {
 422                         .fattr = &fattr,
 423         };
 424         int error;
 425
 426         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 427         if (error < 0)
 428                 goto out_err;
 429         buf->f_type = NFS_SUPER_MAGIC;
 430
 431         /*
 432          * Current versions of glibc do not correctly handle the
 433          * case where f_frsize != f_bsize.  Eventually we want to
 434          * report the value of wtmult in this field.
 435          */
 436         buf->f_frsize = dentry->d_sb->s_blocksize;
 437
 438         /*
 439          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 440          * are reported in units of f_frsize.  Linux hasn't had
 441          * an f_frsize field in its statfs struct until recently,
 442          * thus historically Linux's sys_statfs reports these
 443          * fields in units of f_bsize.
 444          */
 445         buf->f_bsize = dentry->d_sb->s_blocksize;
 446         blockbits = dentry->d_sb->s_blocksize_bits;
 447         blockres = (1 << blockbits) - 1;
 448         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 449         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 450         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 451
 452         buf->f_files = res.tfiles;
 453         buf->f_ffree = res.afiles;
 454
 455         buf->f_namelen = server->namelen;
 456
 457         return 0;
 458
 459  out_err:
 460         dprintk("%s: statfs error = %d\n", __func__, -error);
 461         return error;
 462 }
 463
 464 /*
 465  * Map the security flavour number to a name
 466  */
 467 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 468 {
 469         static const struct {
 470                 rpc_authflavor_t flavour;
 471                 const char *str;
 472         } sec_flavours[] = {
 473                 { RPC_AUTH_NULL, "null" },
 474                 { RPC_AUTH_UNIX, "sys" },
 475                 { RPC_AUTH_GSS_KRB5, "krb5" },
 476                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 477                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 478                 { RPC_AUTH_GSS_LKEY, "lkey" },
 479                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 480                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 481                 { RPC_AUTH_GSS_SPKM, "spkm" },
 482                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 483                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 484                 { UINT_MAX, "unknown" }
 485         };
 486         int i;
 487
 488         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 489                 if (sec_flavours[i].flavour == flavour)
 490                         break;
 491         }
 492         return sec_flavours[i].str;
 493 }
 494
 495 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 496                                     int showdefaults)
 497 {
 498         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 499
 500         switch (sap->sa_family) {
 501         case AF_INET: {
 502                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 503                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 504                 break;
 505         }
 506         case AF_INET6: {
 507                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 508                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 509                 break;
 510         }
 511         default:
 512                 if (showdefaults)
 513                         seq_printf(m, ",mountaddr=unspecified");
 514         }
 515
 516         if (nfss->mountd_version || showdefaults)
 517                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 518         if (nfss->mountd_port || showdefaults)
 519                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 520
 521         switch (nfss->mountd_protocol) {
 522         case IPPROTO_UDP:
 523                 seq_printf(m, ",mountproto=udp");
 524                 break;
 525         case IPPROTO_TCP:
 526                 seq_printf(m, ",mountproto=tcp");
 527                 break;
 528         default:
 529                 if (showdefaults)
 530                         seq_printf(m, ",mountproto=auto");
 531         }
 532 }
 533
 534 /*
 535  * Describe the mount options in force on this server representation
 536  */
 537 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 538                                    int showdefaults)
 539 {
 540         static const struct proc_nfs_info {
 541                 int flag;
 542                 const char *str;
 543                 const char *nostr;
 544         } nfs_info[] = {
 545                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 546                 { NFS_MOUNT_POSIX, ",posix", "" },
 547                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 548                 { NFS_MOUNT_NOAC, ",noac", "" },
 549                 { NFS_MOUNT_NONLM, ",nolock", "" },
 550                 { NFS_MOUNT_NOACL, ",noacl", "" },
 551                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 552                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 553                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 554                 { 0, NULL, NULL }
 555         };
 556         const struct proc_nfs_info *nfs_infop;
 557         struct nfs_client *clp = nfss->nfs_client;
 558         u32 version = clp->rpc_ops->version;
 559
 560         seq_printf(m, ",vers=%u", version);
 561         seq_printf(m, ",rsize=%u", nfss->rsize);
 562         seq_printf(m, ",wsize=%u", nfss->wsize);
 563         if (nfss->bsize != 0)
 564                 seq_printf(m, ",bsize=%u", nfss->bsize);
 565         seq_printf(m, ",namlen=%u", nfss->namelen);
 566         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 567                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 568         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 569                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 570         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 571                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 572         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 573                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 574         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 575                 if (nfss->flags & nfs_infop->flag)
 576                         seq_puts(m, nfs_infop->str);
 577                 else
 578                         seq_puts(m, nfs_infop->nostr);
 579         }
 580         seq_printf(m, ",proto=%s",
 581                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 582         if (version == 4) {
 583                 if (nfss->port != NFS_PORT)
 584                         seq_printf(m, ",port=%u", nfss->port);
 585         } else
 586                 if (nfss->port)
 587                         seq_printf(m, ",port=%u", nfss->port);
 588
 589         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 590         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 591         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 592
 593         if (version != 4)
 594                 nfs_show_mountd_options(m, nfss, showdefaults);
 595
 596 #ifdef CONFIG_NFS_V4
 597         if (clp->rpc_ops->version == 4)
 598                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 599 #endif
 600         if (nfss->options & NFS_OPTION_FSCACHE)
 601                 seq_printf(m, ",fsc");
 602 }
 603
 604 /*
 605  * Describe the mount options on this VFS mountpoint
 606  */
 607 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 608 {
 609         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 610
 611         nfs_show_mount_options(m, nfss, 0);
 612
 613         seq_printf(m, ",addr=%s",
 614                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 615                                                         RPC_DISPLAY_ADDR));
 616
 617         return 0;
 618 }
 619
 620 /*
 621  * Present statistical information for this VFS mountpoint
 622  */
 623 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 624 {
 625         int i, cpu;
 626         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 627         struct rpc_auth *auth = nfss->client->cl_auth;
 628         struct nfs_iostats totals = { };
 629
 630         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 631
 632         /*
 633          * Display all mount option settings
 634          */
 635         seq_printf(m, "\n\topts:\t");
 636         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 637         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 638         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 639         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 640         nfs_show_mount_options(m, nfss, 1);
 641
 642         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 643
 644         seq_printf(m, "\n\tcaps:\t");
 645         seq_printf(m, "caps=0x%x", nfss->caps);
 646         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 647         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 648         seq_printf(m, ",bsize=%u", nfss->bsize);
 649         seq_printf(m, ",namlen=%u", nfss->namelen);
 650
 651 #ifdef CONFIG_NFS_V4
 652         if (nfss->nfs_client->rpc_ops->version == 4) {
 653                 seq_printf(m, "\n\tnfsv4:\t");
 654                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 655                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 656                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 657         }
 658 #endif
 659
 660         /*
 661          * Display security flavor in effect for this mount
 662          */
 663         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 664         if (auth->au_flavor)
 665                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 666
 667         /*
 668          * Display superblock I/O counters
 669          */
 670         for_each_possible_cpu(cpu) {
 671                 struct nfs_iostats *stats;
 672
 673                 preempt_disable();
 674                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 675
 676                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 677                         totals.events[i] += stats->events[i];
 678                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 679                         totals.bytes[i] += stats->bytes[i];
 680 #ifdef CONFIG_NFS_FSCACHE
 681                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 682                         totals.fscache[i] += stats->fscache[i];
 683 #endif
 684
 685                 preempt_enable();
 686         }
 687
 688         seq_printf(m, "\n\tevents:\t");
 689         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 690                 seq_printf(m, "%lu ", totals.events[i]);
 691         seq_printf(m, "\n\tbytes:\t");
 692         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 693                 seq_printf(m, "%Lu ", totals.bytes[i]);
 694 #ifdef CONFIG_NFS_FSCACHE
 695         if (nfss->options & NFS_OPTION_FSCACHE) {
 696                 seq_printf(m, "\n\tfsc:\t");
 697                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 698                         seq_printf(m, "%Lu ", totals.bytes[i]);
 699         }
 700 #endif
 701         seq_printf(m, "\n");
 702
 703         rpc_print_iostats(m, nfss->client);
 704
 705         return 0;
 706 }
 707
 708 /*
 709  * Begin unmount by attempting to remove all automounted mountpoints we added
 710  * in response to xdev traversals and referrals
 711  */
 712 static void nfs_umount_begin(struct super_block *sb)
 713 {
 714         struct nfs_server *server;
 715         struct rpc_clnt *rpc;
 716
 717         lock_kernel();
 718
 719         server = NFS_SB(sb);
 720         /* -EIO all pending I/O */
 721         rpc = server->client_acl;
 722         if (!IS_ERR(rpc))
 723                 rpc_killall_tasks(rpc);
 724         rpc = server->client;
 725         if (!IS_ERR(rpc))
 726                 rpc_killall_tasks(rpc);
 727
 728         unlock_kernel();
 729 }
 730
 731 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 732 {
 733         struct nfs_parsed_mount_data *data;
 734
 735         data = kzalloc(sizeof(*data), GFP_KERNEL);
 736         if (data) {
 737                 data->rsize             = NFS_MAX_FILE_IO_SIZE;
 738                 data->wsize             = NFS_MAX_FILE_IO_SIZE;
 739                 data->acregmin          = NFS_DEF_ACREGMIN;
 740                 data->acregmax          = NFS_DEF_ACREGMAX;
 741                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 742                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 743                 data->mount_server.port = NFS_UNSPEC_PORT;
 744                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 745                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 746                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 747                 data->auth_flavor_len   = 1;
 748                 data->version           = version;
 749                 data->minorversion      = 0;
 750         }
 751         return data;
 752 }
 753
 754 /*
 755  * Sanity-check a server address provided by the mount command.
 756  *
 757  * Address family must be initialized, and address must not be
 758  * the ANY address for that family.
 759  */
 760 static int nfs_verify_server_address(struct sockaddr *addr)
 761 {
 762         switch (addr->sa_family) {
 763         case AF_INET: {
 764                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 765                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 766         }
 767         case AF_INET6: {
 768                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 769                 return !ipv6_addr_any(sa);
 770         }
 771         }
 772
 773         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 774         return 0;
 775 }
 776
 777 /*
 778  * Select between a default port value and a user-specified port value.
 779  * If a zero value is set, then autobind will be used.
 780  */
 781 static void nfs_set_default_port(struct sockaddr *sap, const int parsed_port,
 782                                  const unsigned short default_port)
 783 {
 784         unsigned short port = default_port;
 785
 786         if (parsed_port != NFS_UNSPEC_PORT)
 787                 port = parsed_port;
 788
 789         rpc_set_port(sap, port);
 790 }
 791
 792 /*
 793  * Sanity check the NFS transport protocol.
 794  *
 795  */
 796 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 797 {
 798         switch (mnt->nfs_server.protocol) {
 799         case XPRT_TRANSPORT_UDP:
 800         case XPRT_TRANSPORT_TCP:
 801         case XPRT_TRANSPORT_RDMA:
 802                 break;
 803         default:
 804                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 805         }
 806 }
 807
 808 /*
 809  * For text based NFSv2/v3 mounts, the mount protocol transport default
 810  * settings should depend upon the specified NFS transport.
 811  */
 812 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 813 {
 814         nfs_validate_transport_protocol(mnt);
 815
 816         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 817             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 818                         return;
 819         switch (mnt->nfs_server.protocol) {
 820         case XPRT_TRANSPORT_UDP:
 821                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 822                 break;
 823         case XPRT_TRANSPORT_TCP:
 824         case XPRT_TRANSPORT_RDMA:
 825                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 826         }
 827 }
 828
 829 /*
 830  * Parse the value of the 'sec=' option.
 831  */
 832 static int nfs_parse_security_flavors(char *value,
 833                                       struct nfs_parsed_mount_data *mnt)
 834 {
 835         substring_t args[MAX_OPT_ARGS];
 836
 837         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 838
 839         switch (match_token(value, nfs_secflavor_tokens, args)) {
 840         case Opt_sec_none:
 841                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 842                 break;
 843         case Opt_sec_sys:
 844                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 845                 break;
 846         case Opt_sec_krb5:
 847                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 848                 break;
 849         case Opt_sec_krb5i:
 850                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 851                 break;
 852         case Opt_sec_krb5p:
 853                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 854                 break;
 855         case Opt_sec_lkey:
 856                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 857                 break;
 858         case Opt_sec_lkeyi:
 859                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 860                 break;
 861         case Opt_sec_lkeyp:
 862                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 863                 break;
 864         case Opt_sec_spkm:
 865                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 866                 break;
 867         case Opt_sec_spkmi:
 868                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 869                 break;
 870         case Opt_sec_spkmp:
 871                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 872                 break;
 873         default:
 874                 return 0;
 875         }
 876
 877         mnt->auth_flavor_len = 1;
 878         return 1;
 879 }
 880
 881 /*
 882  * Error-check and convert a string of mount options from user space into
 883  * a data structure.  The whole mount string is processed; bad options are
 884  * skipped as they are encountered.  If there were no errors, return 1;
 885  * otherwise return 0 (zero).
 886  */
 887 static int nfs_parse_mount_options(char *raw,
 888                                    struct nfs_parsed_mount_data *mnt)
 889 {
 890         char *p, *string, *secdata;
 891         int rc, sloppy = 0, invalid_option = 0;
 892
 893         if (!raw) {
 894                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 895                 return 1;
 896         }
 897         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 898
 899         secdata = alloc_secdata();
 900         if (!secdata)
 901                 goto out_nomem;
 902
 903         rc = security_sb_copy_data(raw, secdata);
 904         if (rc)
 905                 goto out_security_failure;
 906
 907         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 908         if (rc)
 909                 goto out_security_failure;
 910
 911         free_secdata(secdata);
 912
 913         while ((p = strsep(&raw, ",")) != NULL) {
 914                 substring_t args[MAX_OPT_ARGS];
 915                 unsigned long option;
 916                 int token;
 917
 918                 if (!*p)
 919                         continue;
 920
 921                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 922
 923                 token = match_token(p, nfs_mount_option_tokens, args);
 924                 switch (token) {
 925
 926                 /*
 927                  * boolean options:  foo/nofoo
 928                  */
 929                 case Opt_soft:
 930                         mnt->flags |= NFS_MOUNT_SOFT;
 931                         break;
 932                 case Opt_hard:
 933                         mnt->flags &= ~NFS_MOUNT_SOFT;
 934                         break;
 935                 case Opt_posix:
 936                         mnt->flags |= NFS_MOUNT_POSIX;
 937                         break;
 938                 case Opt_noposix:
 939                         mnt->flags &= ~NFS_MOUNT_POSIX;
 940                         break;
 941                 case Opt_cto:
 942                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 943                         break;
 944                 case Opt_nocto:
 945                         mnt->flags |= NFS_MOUNT_NOCTO;
 946                         break;
 947                 case Opt_ac:
 948                         mnt->flags &= ~NFS_MOUNT_NOAC;
 949                         break;
 950                 case Opt_noac:
 951                         mnt->flags |= NFS_MOUNT_NOAC;
 952                         break;
 953                 case Opt_lock:
 954                         mnt->flags &= ~NFS_MOUNT_NONLM;
 955                         break;
 956                 case Opt_nolock:
 957                         mnt->flags |= NFS_MOUNT_NONLM;
 958                         break;
 959                 case Opt_v2:
 960                         mnt->flags &= ~NFS_MOUNT_VER3;
 961                         mnt->version = 2;
 962                         break;
 963                 case Opt_v3:
 964                         mnt->flags |= NFS_MOUNT_VER3;
 965                         mnt->version = 3;
 966                         break;
 967 #ifdef CONFIG_NFS_V4
 968                 case Opt_v4:
 969                         mnt->flags &= ~NFS_MOUNT_VER3;
 970                         mnt->version = 4;
 971                         break;
 972 #endif
 973                 case Opt_udp:
 974                         mnt->flags &= ~NFS_MOUNT_TCP;
 975                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 976                         break;
 977                 case Opt_tcp:
 978                         mnt->flags |= NFS_MOUNT_TCP;
 979                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 980                         break;
 981                 case Opt_rdma:
 982                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 983                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 984                         xprt_load_transport(p);
 985                         break;
 986                 case Opt_acl:
 987                         mnt->flags &= ~NFS_MOUNT_NOACL;
 988                         break;
 989                 case Opt_noacl:
 990                         mnt->flags |= NFS_MOUNT_NOACL;
 991                         break;
 992                 case Opt_rdirplus:
 993                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 994                         break;
 995                 case Opt_nordirplus:
 996                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 997                         break;
 998                 case Opt_sharecache:
 999                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1000                         break;
1001                 case Opt_nosharecache:
1002                         mnt->flags |= NFS_MOUNT_UNSHARED;
1003                         break;
1004                 case Opt_resvport:
1005                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1006                         break;
1007                 case Opt_noresvport:
1008                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1009                         break;
1010                 case Opt_fscache:
1011                         mnt->options |= NFS_OPTION_FSCACHE;
1012                         kfree(mnt->fscache_uniq);
1013                         mnt->fscache_uniq = NULL;
1014                         break;
1015                 case Opt_nofscache:
1016                         mnt->options &= ~NFS_OPTION_FSCACHE;
1017                         kfree(mnt->fscache_uniq);
1018                         mnt->fscache_uniq = NULL;
1019                         break;
1020                 case Opt_fscache_uniq:
1021                         string = match_strdup(args);
1022                         if (!string)
1023                                 goto out_nomem;
1024                         kfree(mnt->fscache_uniq);
1025                         mnt->fscache_uniq = string;
1026                         mnt->options |= NFS_OPTION_FSCACHE;
1027                         break;
1028
1029                 /*
1030                  * options that take numeric values
1031                  */
1032                 case Opt_port:
1033                         string = match_strdup(args);
1034                         if (string == NULL)
1035                                 goto out_nomem;
1036                         rc = strict_strtoul(string, 10, &option);
1037                         kfree(string);
1038                         if (rc != 0 || option > USHORT_MAX)
1039                                 goto out_invalid_value;
1040                         mnt->nfs_server.port = option;
1041                         break;
1042                 case Opt_rsize:
1043                         string = match_strdup(args);
1044                         if (string == NULL)
1045                                 goto out_nomem;
1046                         rc = strict_strtoul(string, 10, &option);
1047                         kfree(string);
1048                         if (rc != 0)
1049                                 goto out_invalid_value;
1050                         mnt->rsize = option;
1051                         break;
1052                 case Opt_wsize:
1053                         string = match_strdup(args);
1054                         if (string == NULL)
1055                                 goto out_nomem;
1056                         rc = strict_strtoul(string, 10, &option);
1057                         kfree(string);
1058                         if (rc != 0)
1059                                 goto out_invalid_value;
1060                         mnt->wsize = option;
1061                         break;
1062                 case Opt_bsize:
1063                         string = match_strdup(args);
1064                         if (string == NULL)
1065                                 goto out_nomem;
1066                         rc = strict_strtoul(string, 10, &option);
1067                         kfree(string);
1068                         if (rc != 0)
1069                                 goto out_invalid_value;
1070                         mnt->bsize = option;
1071                         break;
1072                 case Opt_timeo:
1073                         string = match_strdup(args);
1074                         if (string == NULL)
1075                                 goto out_nomem;
1076                         rc = strict_strtoul(string, 10, &option);
1077                         kfree(string);
1078                         if (rc != 0 || option == 0)
1079                                 goto out_invalid_value;
1080                         mnt->timeo = option;
1081                         break;
1082                 case Opt_retrans:
1083                         string = match_strdup(args);
1084                         if (string == NULL)
1085                                 goto out_nomem;
1086                         rc = strict_strtoul(string, 10, &option);
1087                         kfree(string);
1088                         if (rc != 0 || option == 0)
1089                                 goto out_invalid_value;
1090                         mnt->retrans = option;
1091                         break;
1092                 case Opt_acregmin:
1093                         string = match_strdup(args);
1094                         if (string == NULL)
1095                                 goto out_nomem;
1096                         rc = strict_strtoul(string, 10, &option);
1097                         kfree(string);
1098                         if (rc != 0)
1099                                 goto out_invalid_value;
1100                         mnt->acregmin = option;
1101                         break;
1102                 case Opt_acregmax:
1103                         string = match_strdup(args);
1104                         if (string == NULL)
1105                                 goto out_nomem;
1106                         rc = strict_strtoul(string, 10, &option);
1107                         kfree(string);
1108                         if (rc != 0)
1109                                 goto out_invalid_value;
1110                         mnt->acregmax = option;
1111                         break;
1112                 case Opt_acdirmin:
1113                         string = match_strdup(args);
1114                         if (string == NULL)
1115                                 goto out_nomem;
1116                         rc = strict_strtoul(string, 10, &option);
1117                         kfree(string);
1118                         if (rc != 0)
1119                                 goto out_invalid_value;
1120                         mnt->acdirmin = option;
1121                         break;
1122                 case Opt_acdirmax:
1123                         string = match_strdup(args);
1124                         if (string == NULL)
1125                                 goto out_nomem;
1126                         rc = strict_strtoul(string, 10, &option);
1127                         kfree(string);
1128                         if (rc != 0)
1129                                 goto out_invalid_value;
1130                         mnt->acdirmax = option;
1131                         break;
1132                 case Opt_actimeo:
1133                         string = match_strdup(args);
1134                         if (string == NULL)
1135                                 goto out_nomem;
1136                         rc = strict_strtoul(string, 10, &option);
1137                         kfree(string);
1138                         if (rc != 0)
1139                                 goto out_invalid_value;
1140                         mnt->acregmin = mnt->acregmax =
1141                         mnt->acdirmin = mnt->acdirmax = option;
1142                         break;
1143                 case Opt_namelen:
1144                         string = match_strdup(args);
1145                         if (string == NULL)
1146                                 goto out_nomem;
1147                         rc = strict_strtoul(string, 10, &option);
1148                         kfree(string);
1149                         if (rc != 0)
1150                                 goto out_invalid_value;
1151                         mnt->namlen = option;
1152                         break;
1153                 case Opt_mountport:
1154                         string = match_strdup(args);
1155                         if (string == NULL)
1156                                 goto out_nomem;
1157                         rc = strict_strtoul(string, 10, &option);
1158                         kfree(string);
1159                         if (rc != 0 || option > USHORT_MAX)
1160                                 goto out_invalid_value;
1161                         mnt->mount_server.port = option;
1162                         break;
1163                 case Opt_mountvers:
1164                         string = match_strdup(args);
1165                         if (string == NULL)
1166                                 goto out_nomem;
1167                         rc = strict_strtoul(string, 10, &option);
1168                         kfree(string);
1169                         if (rc != 0 ||
1170                             option < NFS_MNT_VERSION ||
1171                             option > NFS_MNT3_VERSION)
1172                                 goto out_invalid_value;
1173                         mnt->mount_server.version = option;
1174                         break;
1175                 case Opt_nfsvers:
1176                         string = match_strdup(args);
1177                         if (string == NULL)
1178                                 goto out_nomem;
1179                         rc = strict_strtoul(string, 10, &option);
1180                         kfree(string);
1181                         if (rc != 0)
1182                                 goto out_invalid_value;
1183                         switch (option) {
1184                         case NFS2_VERSION:
1185                                 mnt->flags &= ~NFS_MOUNT_VER3;
1186                                 mnt->version = 2;
1187                                 break;
1188                         case NFS3_VERSION:
1189                                 mnt->flags |= NFS_MOUNT_VER3;
1190                                 mnt->version = 3;
1191                                 break;
1192 #ifdef CONFIG_NFS_V4
1193                         case NFS4_VERSION:
1194                                 mnt->flags &= ~NFS_MOUNT_VER3;
1195                                 mnt->version = 4;
1196                                 break;
1197 #endif
1198                         default:
1199                                 goto out_invalid_value;
1200                         }
1201                         break;
1202                 case Opt_minorversion:
1203                         string = match_strdup(args);
1204                         if (string == NULL)
1205                                 goto out_nomem;
1206                         rc = strict_strtoul(string, 10, &option);
1207                         kfree(string);
1208                         if (rc != 0)
1209                                 goto out_invalid_value;
1210                         if (option > NFS4_MAX_MINOR_VERSION)
1211                                 goto out_invalid_value;
1212                         mnt->minorversion = option;
1213                         break;
1214
1215                 /*
1216                  * options that take text values
1217                  */
1218                 case Opt_sec:
1219                         string = match_strdup(args);
1220                         if (string == NULL)
1221                                 goto out_nomem;
1222                         rc = nfs_parse_security_flavors(string, mnt);
1223                         kfree(string);
1224                         if (!rc) {
1225                                 dfprintk(MOUNT, "NFS:   unrecognized "
1226                                                 "security flavor\n");
1227                                 return 0;
1228                         }
1229                         break;
1230                 case Opt_proto:
1231                         string = match_strdup(args);
1232                         if (string == NULL)
1233                                 goto out_nomem;
1234                         token = match_token(string,
1235                                             nfs_xprt_protocol_tokens, args);
1236
1237                         switch (token) {
1238                         case Opt_xprt_udp:
1239                                 mnt->flags &= ~NFS_MOUNT_TCP;
1240                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1241                                 kfree(string);
1242                                 break;
1243                         case Opt_xprt_tcp:
1244                                 mnt->flags |= NFS_MOUNT_TCP;
1245                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1246                                 kfree(string);
1247                                 break;
1248                         case Opt_xprt_rdma:
1249                                 /* vector side protocols to TCP */
1250                                 mnt->flags |= NFS_MOUNT_TCP;
1251                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1252                                 xprt_load_transport(string);
1253                                 kfree(string);
1254                                 break;
1255                         default:
1256                                 dfprintk(MOUNT, "NFS:   unrecognized "
1257                                                 "transport protocol\n");
1258                                 return 0;
1259                         }
1260                         break;
1261                 case Opt_mountproto:
1262                         string = match_strdup(args);
1263                         if (string == NULL)
1264                                 goto out_nomem;
1265                         token = match_token(string,
1266                                             nfs_xprt_protocol_tokens, args);
1267                         kfree(string);
1268
1269                         switch (token) {
1270                         case Opt_xprt_udp:
1271                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1272                                 break;
1273                         case Opt_xprt_tcp:
1274                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1275                                 break;
1276                         case Opt_xprt_rdma: /* not used for side protocols */
1277                         default:
1278                                 dfprintk(MOUNT, "NFS:   unrecognized "
1279                                                 "transport protocol\n");
1280                                 return 0;
1281                         }
1282                         break;
1283                 case Opt_addr:
1284                         string = match_strdup(args);
1285                         if (string == NULL)
1286                                 goto out_nomem;
1287                         mnt->nfs_server.addrlen =
1288                                 rpc_pton(string, strlen(string),
1289                                         (struct sockaddr *)
1290                                         &mnt->nfs_server.address,
1291                                         sizeof(mnt->nfs_server.address));
1292                         kfree(string);
1293                         if (mnt->nfs_server.addrlen == 0)
1294                                 goto out_invalid_address;
1295                         break;
1296                 case Opt_clientaddr:
1297                         string = match_strdup(args);
1298                         if (string == NULL)
1299                                 goto out_nomem;
1300                         kfree(mnt->client_address);
1301                         mnt->client_address = string;
1302                         break;
1303                 case Opt_mounthost:
1304                         string = match_strdup(args);
1305                         if (string == NULL)
1306                                 goto out_nomem;
1307                         kfree(mnt->mount_server.hostname);
1308                         mnt->mount_server.hostname = string;
1309                         break;
1310                 case Opt_mountaddr:
1311                         string = match_strdup(args);
1312                         if (string == NULL)
1313                                 goto out_nomem;
1314                         mnt->mount_server.addrlen =
1315                                 rpc_pton(string, strlen(string),
1316                                         (struct sockaddr *)
1317                                         &mnt->mount_server.address,
1318                                         sizeof(mnt->mount_server.address));
1319                         kfree(string);
1320                         if (mnt->mount_server.addrlen == 0)
1321                                 goto out_invalid_address;
1322                         break;
1323                 case Opt_lookupcache:
1324                         string = match_strdup(args);
1325                         if (string == NULL)
1326                                 goto out_nomem;
1327                         token = match_token(string,
1328                                         nfs_lookupcache_tokens, args);
1329                         kfree(string);
1330                         switch (token) {
1331                                 case Opt_lookupcache_all:
1332                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1333                                         break;
1334                                 case Opt_lookupcache_positive:
1335                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1336                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1337                                         break;
1338                                 case Opt_lookupcache_none:
1339                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1340                                         break;
1341                                 default:
1342                                         dfprintk(MOUNT, "NFS:   invalid "
1343                                                         "lookupcache argument\n");
1344                                         return 0;
1345                         };
1346                         break;
1347
1348                 /*
1349                  * Special options
1350                  */
1351                 case Opt_sloppy:
1352                         sloppy = 1;
1353                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1354                         break;
1355                 case Opt_userspace:
1356                 case Opt_deprecated:
1357                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1358                                         "'%s'\n", p);
1359                         break;
1360
1361                 default:
1362                         invalid_option = 1;
1363                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1364                                         "'%s'\n", p);
1365                 }
1366         }
1367
1368         if (!sloppy && invalid_option)
1369                 return 0;
1370
1371         return 1;
1372
1373 out_invalid_address:
1374         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1375         return 0;
1376 out_invalid_value:
1377         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1378         return 0;
1379 out_nomem:
1380         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1381         return 0;
1382 out_security_failure:
1383         free_secdata(secdata);
1384         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1385         return 0;
1386 }
1387
1388 /*
1389  * Match the requested auth flavors with the list returned by
1390  * the server.  Returns zero and sets the mount's authentication
1391  * flavor on success; returns -EACCES if server does not support
1392  * the requested flavor.
1393  */
1394 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1395                              struct nfs_mount_request *request)
1396 {
1397         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1398
1399         /*
1400          * Certain releases of Linux's mountd return an empty
1401          * flavor list.  To prevent behavioral regression with
1402          * these servers (ie. rejecting mounts that used to
1403          * succeed), revert to pre-2.6.32 behavior (no checking)
1404          * if the returned flavor list is empty.
1405          */
1406         if (server_authlist_len == 0)
1407                 return 0;
1408
1409         /*
1410          * We avoid sophisticated negotiating here, as there are
1411          * plenty of cases where we can get it wrong, providing
1412          * either too little or too much security.
1413          *
1414          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1415          * flavor listed first.  However, some servers list
1416          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1417          * preferred default, in args->auth_flavors[0] if user
1418          * didn't specify sec= mount option.
1419          */
1420         for (i = 0; i < args->auth_flavor_len; i++)
1421                 for (j = 0; j < server_authlist_len; j++)
1422                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1423                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1424                                         request->auth_flavs[j]);
1425                                 args->auth_flavors[0] = request->auth_flavs[j];
1426                                 return 0;
1427                         }
1428
1429         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1430         nfs_umount(request);
1431         return -EACCES;
1432 }
1433
1434 /*
1435  * Use the remote server's MOUNT service to request the NFS file handle
1436  * corresponding to the provided path.
1437  */
1438 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1439                          struct nfs_fh *root_fh)
1440 {
1441         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1442         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1443         struct nfs_mount_request request = {
1444                 .sap            = (struct sockaddr *)
1445                                                 &args->mount_server.address,
1446                 .dirpath        = args->nfs_server.export_path,
1447                 .protocol       = args->mount_server.protocol,
1448                 .fh             = root_fh,
1449                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1450                 .auth_flav_len  = &server_authlist_len,
1451                 .auth_flavs     = server_authlist,
1452         };
1453         int status;
1454
1455         if (args->mount_server.version == 0) {
1456                 switch (args->version) {
1457                         default:
1458                                 args->mount_server.version = NFS_MNT3_VERSION;
1459                                 break;
1460                         case 2:
1461                                 args->mount_server.version = NFS_MNT_VERSION;
1462                 }
1463         }
1464         request.version = args->mount_server.version;
1465
1466         if (args->mount_server.hostname)
1467                 request.hostname = args->mount_server.hostname;
1468         else
1469                 request.hostname = args->nfs_server.hostname;
1470
1471         /*
1472          * Construct the mount server's address.
1473          */
1474         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1475                 memcpy(request.sap, &args->nfs_server.address,
1476                        args->nfs_server.addrlen);
1477                 args->mount_server.addrlen = args->nfs_server.addrlen;
1478         }
1479         request.salen = args->mount_server.addrlen;
1480         nfs_set_default_port(request.sap, args->mount_server.port, 0);
1481
1482         /*
1483          * Now ask the mount server to map our export path
1484          * to a file handle.
1485          */
1486         status = nfs_mount(&request);
1487         if (status != 0) {
1488                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1489                                 request.hostname, status);
1490                 return status;
1491         }
1492
1493         /*
1494          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1495          */
1496         if (args->mount_server.version != NFS_MNT3_VERSION)
1497                 return 0;
1498         return nfs_walk_authlist(args, &request);
1499 }
1500
1501 static int nfs_parse_simple_hostname(const char *dev_name,
1502                                      char **hostname, size_t maxnamlen,
1503                                      char **export_path, size_t maxpathlen)
1504 {
1505         size_t len;
1506         char *colon, *comma;
1507
1508         colon = strchr(dev_name, ':');
1509         if (colon == NULL)
1510                 goto out_bad_devname;
1511
1512         len = colon - dev_name;
1513         if (len > maxnamlen)
1514                 goto out_hostname;
1515
1516         /* N.B. caller will free nfs_server.hostname in all cases */
1517         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1518         if (!*hostname)
1519                 goto out_nomem;
1520
1521         /* kill possible hostname list: not supported */
1522         comma = strchr(*hostname, ',');
1523         if (comma != NULL) {
1524                 if (comma == *hostname)
1525                         goto out_bad_devname;
1526                 *comma = '\0';
1527         }
1528
1529         colon++;
1530         len = strlen(colon);
1531         if (len > maxpathlen)
1532                 goto out_path;
1533         *export_path = kstrndup(colon, len, GFP_KERNEL);
1534         if (!*export_path)
1535                 goto out_nomem;
1536
1537         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1538         return 0;
1539
1540 out_bad_devname:
1541         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1542         return -EINVAL;
1543
1544 out_nomem:
1545         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1546         return -ENOMEM;
1547
1548 out_hostname:
1549         dfprintk(MOUNT, "NFS: server hostname too long\n");
1550         return -ENAMETOOLONG;
1551
1552 out_path:
1553         dfprintk(MOUNT, "NFS: export pathname too long\n");
1554         return -ENAMETOOLONG;
1555 }
1556
1557 /*
1558  * Hostname has square brackets around it because it contains one or
1559  * more colons.  We look for the first closing square bracket, and a
1560  * colon must follow it.
1561  */
1562 static int nfs_parse_protected_hostname(const char *dev_name,
1563                                         char **hostname, size_t maxnamlen,
1564                                         char **export_path, size_t maxpathlen)
1565 {
1566         size_t len;
1567         char *start, *end;
1568
1569         start = (char *)(dev_name + 1);
1570
1571         end = strchr(start, ']');
1572         if (end == NULL)
1573                 goto out_bad_devname;
1574         if (*(end + 1) != ':')
1575                 goto out_bad_devname;
1576
1577         len = end - start;
1578         if (len > maxnamlen)
1579                 goto out_hostname;
1580
1581         /* N.B. caller will free nfs_server.hostname in all cases */
1582         *hostname = kstrndup(start, len, GFP_KERNEL);
1583         if (*hostname == NULL)
1584                 goto out_nomem;
1585
1586         end += 2;
1587         len = strlen(end);
1588         if (len > maxpathlen)
1589                 goto out_path;
1590         *export_path = kstrndup(end, len, GFP_KERNEL);
1591         if (!*export_path)
1592                 goto out_nomem;
1593
1594         return 0;
1595
1596 out_bad_devname:
1597         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1598         return -EINVAL;
1599
1600 out_nomem:
1601         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1602         return -ENOMEM;
1603
1604 out_hostname:
1605         dfprintk(MOUNT, "NFS: server hostname too long\n");
1606         return -ENAMETOOLONG;
1607
1608 out_path:
1609         dfprintk(MOUNT, "NFS: export pathname too long\n");
1610         return -ENAMETOOLONG;
1611 }
1612
1613 /*
1614  * Split "dev_name" into "hostname:export_path".
1615  *
1616  * The leftmost colon demarks the split between the server's hostname
1617  * and the export path.  If the hostname starts with a left square
1618  * bracket, then it may contain colons.
1619  *
1620  * Note: caller frees hostname and export path, even on error.
1621  */
1622 static int nfs_parse_devname(const char *dev_name,
1623                              char **hostname, size_t maxnamlen,
1624                              char **export_path, size_t maxpathlen)
1625 {
1626         if (*dev_name == '[')
1627                 return nfs_parse_protected_hostname(dev_name,
1628                                                     hostname, maxnamlen,
1629                                                     export_path, maxpathlen);
1630
1631         return nfs_parse_simple_hostname(dev_name,
1632                                          hostname, maxnamlen,
1633                                          export_path, maxpathlen);
1634 }
1635
1636 /*
1637  * Validate the NFS2/NFS3 mount data
1638  * - fills in the mount root filehandle
1639  *
1640  * For option strings, user space handles the following behaviors:
1641  *
1642  * + DNS: mapping server host name to IP address ("addr=" option)
1643  *
1644  * + failure mode: how to behave if a mount request can't be handled
1645  *   immediately ("fg/bg" option)
1646  *
1647  * + retry: how often to retry a mount request ("retry=" option)
1648  *
1649  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1650  *   mountproto=tcp after mountproto=udp, and so on
1651  */
1652 static int nfs_validate_mount_data(void *options,
1653                                    struct nfs_parsed_mount_data *args,
1654                                    struct nfs_fh *mntfh,
1655                                    const char *dev_name)
1656 {
1657         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1658         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1659
1660         if (data == NULL)
1661                 goto out_no_data;
1662
1663         switch (data->version) {
1664         case 1:
1665                 data->namlen = 0;
1666         case 2:
1667                 data->bsize = 0;
1668         case 3:
1669                 if (data->flags & NFS_MOUNT_VER3)
1670                         goto out_no_v3;
1671                 data->root.size = NFS2_FHSIZE;
1672                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1673         case 4:
1674                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1675                         goto out_no_sec;
1676         case 5:
1677                 memset(data->context, 0, sizeof(data->context));
1678         case 6:
1679                 if (data->flags & NFS_MOUNT_VER3) {
1680                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1681                                 goto out_invalid_fh;
1682                         mntfh->size = data->root.size;
1683                         args->version = 3;
1684                 } else {
1685                         mntfh->size = NFS2_FHSIZE;
1686                         args->version = 2;
1687                 }
1688
1689
1690                 memcpy(mntfh->data, data->root.data, mntfh->size);
1691                 if (mntfh->size < sizeof(mntfh->data))
1692                         memset(mntfh->data + mntfh->size, 0,
1693                                sizeof(mntfh->data) - mntfh->size);
1694
1695                 /*
1696                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1697                  * can deal with.
1698                  */
1699                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1700                 args->rsize             = data->rsize;
1701                 args->wsize             = data->wsize;
1702                 args->timeo             = data->timeo;
1703                 args->retrans           = data->retrans;
1704                 args->acregmin          = data->acregmin;
1705                 args->acregmax          = data->acregmax;
1706                 args->acdirmin          = data->acdirmin;
1707                 args->acdirmax          = data->acdirmax;
1708
1709                 memcpy(sap, &data->addr, sizeof(data->addr));
1710                 args->nfs_server.addrlen = sizeof(data->addr);
1711                 if (!nfs_verify_server_address(sap))
1712                         goto out_no_address;
1713
1714                 if (!(data->flags & NFS_MOUNT_TCP))
1715                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1716                 /* N.B. caller will free nfs_server.hostname in all cases */
1717                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1718                 args->namlen            = data->namlen;
1719                 args->bsize             = data->bsize;
1720
1721                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1722                         args->auth_flavors[0] = data->pseudoflavor;
1723                 if (!args->nfs_server.hostname)
1724                         goto out_nomem;
1725
1726                 /*
1727                  * The legacy version 6 binary mount data from userspace has a
1728                  * field used only to transport selinux information into the
1729                  * the kernel.  To continue to support that functionality we
1730                  * have a touch of selinux knowledge here in the NFS code. The
1731                  * userspace code converted context=blah to just blah so we are
1732                  * converting back to the full string selinux understands.
1733                  */
1734                 if (data->context[0]){
1735 #ifdef CONFIG_SECURITY_SELINUX
1736                         int rc;
1737                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1738                         if (!opts_str)
1739                                 return -ENOMEM;
1740                         strcpy(opts_str, "context=");
1741                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1742                         strcat(opts_str, &data->context[0]);
1743                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1744                         kfree(opts_str);
1745                         if (rc)
1746                                 return rc;
1747 #else
1748                         return -EINVAL;
1749 #endif
1750                 }
1751
1752                 break;
1753         default: {
1754                 int status;
1755
1756                 if (nfs_parse_mount_options((char *)options, args) == 0)
1757                         return -EINVAL;
1758
1759                 if (!nfs_verify_server_address(sap))
1760                         goto out_no_address;
1761
1762                 if (args->version == 4)
1763 #ifdef CONFIG_NFS_V4
1764                         return nfs4_validate_text_mount_data(options,
1765                                                              args, dev_name);
1766 #else
1767                         goto out_v4_not_compiled;
1768 #endif
1769
1770                 nfs_set_default_port(sap, args->nfs_server.port, 0);
1771
1772                 nfs_set_mount_transport_protocol(args);
1773
1774                 status = nfs_parse_devname(dev_name,
1775                                            &args->nfs_server.hostname,
1776                                            PAGE_SIZE,
1777                                            &args->nfs_server.export_path,
1778                                            NFS_MAXPATHLEN);
1779                 if (!status)
1780                         status = nfs_try_mount(args, mntfh);
1781
1782                 kfree(args->nfs_server.export_path);
1783                 args->nfs_server.export_path = NULL;
1784
1785                 if (status)
1786                         return status;
1787
1788                 break;
1789                 }
1790         }
1791
1792 #ifndef CONFIG_NFS_V3
1793         if (args->version == 3)
1794                 goto out_v3_not_compiled;
1795 #endif /* !CONFIG_NFS_V3 */
1796
1797         return 0;
1798
1799 out_no_data:
1800         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1801         return -EINVAL;
1802
1803 out_no_v3:
1804         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1805                  data->version);
1806         return -EINVAL;
1807
1808 out_no_sec:
1809         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1810         return -EINVAL;
1811
1812 #ifndef CONFIG_NFS_V3
1813 out_v3_not_compiled:
1814         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1815         return -EPROTONOSUPPORT;
1816 #endif /* !CONFIG_NFS_V3 */
1817
1818 #ifndef CONFIG_NFS_V4
1819 out_v4_not_compiled:
1820         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1821         return -EPROTONOSUPPORT;
1822 #endif /* !CONFIG_NFS_V4 */
1823
1824 out_nomem:
1825         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1826         return -ENOMEM;
1827
1828 out_no_address:
1829         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1830         return -EINVAL;
1831
1832 out_invalid_fh:
1833         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1834         return -EINVAL;
1835 }
1836
1837 static int
1838 nfs_compare_remount_data(struct nfs_server *nfss,
1839                          struct nfs_parsed_mount_data *data)
1840 {
1841         if (data->flags != nfss->flags ||
1842             data->rsize != nfss->rsize ||
1843             data->wsize != nfss->wsize ||
1844             data->retrans != nfss->client->cl_timeout->to_retries ||
1845             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1846             data->acregmin != nfss->acregmin / HZ ||
1847             data->acregmax != nfss->acregmax / HZ ||
1848             data->acdirmin != nfss->acdirmin / HZ ||
1849             data->acdirmax != nfss->acdirmax / HZ ||
1850             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1851             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1852             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1853                    data->nfs_server.addrlen) != 0)
1854                 return -EINVAL;
1855
1856         return 0;
1857 }
1858
1859 static int
1860 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1861 {
1862         int error;
1863         struct nfs_server *nfss = sb->s_fs_info;
1864         struct nfs_parsed_mount_data *data;
1865         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1866         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1867         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1868
1869         /*
1870          * Userspace mount programs that send binary options generally send
1871          * them populated with default values. We have no way to know which
1872          * ones were explicitly specified. Fall back to legacy behavior and
1873          * just return success.
1874          */
1875         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1876             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1877                                            options->version <= 6))))
1878                 return 0;
1879
1880         data = kzalloc(sizeof(*data), GFP_KERNEL);
1881         if (data == NULL)
1882                 return -ENOMEM;
1883
1884         lock_kernel();
1885         /* fill out struct with values from existing mount */
1886         data->flags = nfss->flags;
1887         data->rsize = nfss->rsize;
1888         data->wsize = nfss->wsize;
1889         data->retrans = nfss->client->cl_timeout->to_retries;
1890         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1891         data->acregmin = nfss->acregmin / HZ;
1892         data->acregmax = nfss->acregmax / HZ;
1893         data->acdirmin = nfss->acdirmin / HZ;
1894         data->acdirmax = nfss->acdirmax / HZ;
1895         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1896         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1897         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1898                 data->nfs_server.addrlen);
1899
1900         /* overwrite those values with any that were specified */
1901         error = nfs_parse_mount_options((char *)options, data);
1902         if (error < 0)
1903                 goto out;
1904
1905         /* compare new mount options with old ones */
1906         error = nfs_compare_remount_data(nfss, data);
1907 out:
1908         kfree(data);
1909         unlock_kernel();
1910         return error;
1911 }
1912
1913 /*
1914  * Initialise the common bits of the superblock
1915  */
1916 static inline void nfs_initialise_sb(struct super_block *sb)
1917 {
1918         struct nfs_server *server = NFS_SB(sb);
1919
1920         sb->s_magic = NFS_SUPER_MAGIC;
1921
1922         /* We probably want something more informative here */
1923         snprintf(sb->s_id, sizeof(sb->s_id),
1924                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1925
1926         if (sb->s_blocksize == 0)
1927                 sb->s_blocksize = nfs_block_bits(server->wsize,
1928                                                  &sb->s_blocksize_bits);
1929
1930         if (server->flags & NFS_MOUNT_NOAC)
1931                 sb->s_flags |= MS_SYNCHRONOUS;
1932
1933         sb->s_bdi = &server->backing_dev_info;
1934
1935         nfs_super_set_maxbytes(sb, server->maxfilesize);
1936 }
1937
1938 /*
1939  * Finish setting up an NFS2/3 superblock
1940  */
1941 static void nfs_fill_super(struct super_block *sb,
1942                            struct nfs_parsed_mount_data *data)
1943 {
1944         struct nfs_server *server = NFS_SB(sb);
1945
1946         sb->s_blocksize_bits = 0;
1947         sb->s_blocksize = 0;
1948         if (data->bsize)
1949                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1950
1951         if (server->nfs_client->rpc_ops->version == 3) {
1952                 /* The VFS shouldn't apply the umask to mode bits. We will do
1953                  * so ourselves when necessary.
1954                  */
1955                 sb->s_flags |= MS_POSIXACL;
1956                 sb->s_time_gran = 1;
1957         }
1958
1959         sb->s_op = &nfs_sops;
1960         nfs_initialise_sb(sb);
1961 }
1962
1963 /*
1964  * Finish setting up a cloned NFS2/3 superblock
1965  */
1966 static void nfs_clone_super(struct super_block *sb,
1967                             const struct super_block *old_sb)
1968 {
1969         struct nfs_server *server = NFS_SB(sb);
1970
1971         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1972         sb->s_blocksize = old_sb->s_blocksize;
1973         sb->s_maxbytes = old_sb->s_maxbytes;
1974
1975         if (server->nfs_client->rpc_ops->version == 3) {
1976                 /* The VFS shouldn't apply the umask to mode bits. We will do
1977                  * so ourselves when necessary.
1978                  */
1979                 sb->s_flags |= MS_POSIXACL;
1980                 sb->s_time_gran = 1;
1981         }
1982
1983         sb->s_op = old_sb->s_op;
1984         nfs_initialise_sb(sb);
1985 }
1986
1987 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1988 {
1989         const struct nfs_server *a = s->s_fs_info;
1990         const struct rpc_clnt *clnt_a = a->client;
1991         const struct rpc_clnt *clnt_b = b->client;
1992
1993         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1994                 goto Ebusy;
1995         if (a->nfs_client != b->nfs_client)
1996                 goto Ebusy;
1997         if (a->flags != b->flags)
1998                 goto Ebusy;
1999         if (a->wsize != b->wsize)
2000                 goto Ebusy;
2001         if (a->rsize != b->rsize)
2002                 goto Ebusy;
2003         if (a->acregmin != b->acregmin)
2004                 goto Ebusy;
2005         if (a->acregmax != b->acregmax)
2006                 goto Ebusy;
2007         if (a->acdirmin != b->acdirmin)
2008                 goto Ebusy;
2009         if (a->acdirmax != b->acdirmax)
2010                 goto Ebusy;
2011         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2012                 goto Ebusy;
2013         return 1;
2014 Ebusy:
2015         return 0;
2016 }
2017
2018 struct nfs_sb_mountdata {
2019         struct nfs_server *server;
2020         int mntflags;
2021 };
2022
2023 static int nfs_set_super(struct super_block *s, void *data)
2024 {
2025         struct nfs_sb_mountdata *sb_mntdata = data;
2026         struct nfs_server *server = sb_mntdata->server;
2027         int ret;
2028
2029         s->s_flags = sb_mntdata->mntflags;
2030         s->s_fs_info = server;
2031         ret = set_anon_super(s, server);
2032         if (ret == 0)
2033                 server->s_dev = s->s_dev;
2034         return ret;
2035 }
2036
2037 static int nfs_compare_super_address(struct nfs_server *server1,
2038                                      struct nfs_server *server2)
2039 {
2040         struct sockaddr *sap1, *sap2;
2041
2042         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2043         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2044
2045         if (sap1->sa_family != sap2->sa_family)
2046                 return 0;
2047
2048         switch (sap1->sa_family) {
2049         case AF_INET: {
2050                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2051                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2052                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2053                         return 0;
2054                 if (sin1->sin_port != sin2->sin_port)
2055                         return 0;
2056                 break;
2057         }
2058         case AF_INET6: {
2059                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2060                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2061                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2062                         return 0;
2063                 if (sin1->sin6_port != sin2->sin6_port)
2064                         return 0;
2065                 break;
2066         }
2067         default:
2068                 return 0;
2069         }
2070
2071         return 1;
2072 }
2073
2074 static int nfs_compare_super(struct super_block *sb, void *data)
2075 {
2076         struct nfs_sb_mountdata *sb_mntdata = data;
2077         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2078         int mntflags = sb_mntdata->mntflags;
2079
2080         if (!nfs_compare_super_address(old, server))
2081                 return 0;
2082         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2083         if (old->flags & NFS_MOUNT_UNSHARED)
2084                 return 0;
2085         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2086                 return 0;
2087         return nfs_compare_mount_options(sb, server, mntflags);
2088 }
2089
2090 static int nfs_bdi_register(struct nfs_server *server)
2091 {
2092         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2093 }
2094
2095 static int nfs_get_sb(struct file_system_type *fs_type,
2096         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2097 {
2098         struct nfs_server *server = NULL;
2099         struct super_block *s;
2100         struct nfs_parsed_mount_data *data;
2101         struct nfs_fh *mntfh;
2102         struct dentry *mntroot;
2103         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2104         struct nfs_sb_mountdata sb_mntdata = {
2105                 .mntflags = flags,
2106         };
2107         int error = -ENOMEM;
2108
2109         data = nfs_alloc_parsed_mount_data(3);
2110         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2111         if (data == NULL || mntfh == NULL)
2112                 goto out_free_fh;
2113
2114         security_init_mnt_opts(&data->lsm_opts);
2115
2116         /* Validate the mount data */
2117         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2118         if (error < 0)
2119                 goto out;
2120
2121 #ifdef CONFIG_NFS_V4
2122         if (data->version == 4) {
2123                 error = nfs4_try_mount(flags, dev_name, data, mnt);
2124                 kfree(data->client_address);
2125                 goto out;
2126         }
2127 #endif  /* CONFIG_NFS_V4 */
2128
2129         /* Get a volume representation */
2130         server = nfs_create_server(data, mntfh);
2131         if (IS_ERR(server)) {
2132                 error = PTR_ERR(server);
2133                 goto out;
2134         }
2135         sb_mntdata.server = server;
2136
2137         if (server->flags & NFS_MOUNT_UNSHARED)
2138                 compare_super = NULL;
2139
2140         /* Get a superblock - note that we may end up sharing one that already exists */
2141         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2142         if (IS_ERR(s)) {
2143                 error = PTR_ERR(s);
2144                 goto out_err_nosb;
2145         }
2146
2147         if (s->s_fs_info != server) {
2148                 nfs_free_server(server);
2149                 server = NULL;
2150         } else {
2151                 error = nfs_bdi_register(server);
2152                 if (error)
2153                         goto error_splat_super;
2154         }
2155
2156         if (!s->s_root) {
2157                 /* initial superblock/root creation */
2158                 nfs_fill_super(s, data);
2159                 nfs_fscache_get_super_cookie(
2160                         s, data ? data->fscache_uniq : NULL, NULL);
2161         }
2162
2163         mntroot = nfs_get_root(s, mntfh);
2164         if (IS_ERR(mntroot)) {
2165                 error = PTR_ERR(mntroot);
2166                 goto error_splat_super;
2167         }
2168
2169         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2170         if (error)
2171                 goto error_splat_root;
2172
2173         s->s_flags |= MS_ACTIVE;
2174         mnt->mnt_sb = s;
2175         mnt->mnt_root = mntroot;
2176         error = 0;
2177
2178 out:
2179         kfree(data->nfs_server.hostname);
2180         kfree(data->mount_server.hostname);
2181         kfree(data->fscache_uniq);
2182         security_free_mnt_opts(&data->lsm_opts);
2183 out_free_fh:
2184         kfree(mntfh);
2185         kfree(data);
2186         return error;
2187
2188 out_err_nosb:
2189         nfs_free_server(server);
2190         goto out;
2191
2192 error_splat_root:
2193         dput(mntroot);
2194 error_splat_super:
2195         deactivate_locked_super(s);
2196         goto out;
2197 }
2198
2199 /*
2200  * Destroy an NFS2/3 superblock
2201  */
2202 static void nfs_kill_super(struct super_block *s)
2203 {
2204         struct nfs_server *server = NFS_SB(s);
2205
2206         kill_anon_super(s);
2207         bdi_unregister(&server->backing_dev_info);
2208         nfs_fscache_release_super_cookie(s);
2209         nfs_free_server(server);
2210 }
2211
2212 /*
2213  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2214  */
2215 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2216                            const char *dev_name, void *raw_data,
2217                            struct vfsmount *mnt)
2218 {
2219         struct nfs_clone_mount *data = raw_data;
2220         struct super_block *s;
2221         struct nfs_server *server;
2222         struct dentry *mntroot;
2223         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2224         struct nfs_sb_mountdata sb_mntdata = {
2225                 .mntflags = flags,
2226         };
2227         int error;
2228
2229         dprintk("--> nfs_xdev_get_sb()\n");
2230
2231         /* create a new volume representation */
2232         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2233         if (IS_ERR(server)) {
2234                 error = PTR_ERR(server);
2235                 goto out_err_noserver;
2236         }
2237         sb_mntdata.server = server;
2238
2239         if (server->flags & NFS_MOUNT_UNSHARED)
2240                 compare_super = NULL;
2241
2242         /* Get a superblock - note that we may end up sharing one that already exists */
2243         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2244         if (IS_ERR(s)) {
2245                 error = PTR_ERR(s);
2246                 goto out_err_nosb;
2247         }
2248
2249         if (s->s_fs_info != server) {
2250                 nfs_free_server(server);
2251                 server = NULL;
2252         } else {
2253                 error = nfs_bdi_register(server);
2254                 if (error)
2255                         goto error_splat_super;
2256         }
2257
2258         if (!s->s_root) {
2259                 /* initial superblock/root creation */
2260                 nfs_clone_super(s, data->sb);
2261                 nfs_fscache_get_super_cookie(s, NULL, data);
2262         }
2263
2264         mntroot = nfs_get_root(s, data->fh);
2265         if (IS_ERR(mntroot)) {
2266                 error = PTR_ERR(mntroot);
2267                 goto error_splat_super;
2268         }
2269         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2270                 dput(mntroot);
2271                 error = -ESTALE;
2272                 goto error_splat_super;
2273         }
2274
2275         s->s_flags |= MS_ACTIVE;
2276         mnt->mnt_sb = s;
2277         mnt->mnt_root = mntroot;
2278
2279         /* clone any lsm security options from the parent to the new sb */
2280         security_sb_clone_mnt_opts(data->sb, s);
2281
2282         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2283         return 0;
2284
2285 out_err_nosb:
2286         nfs_free_server(server);
2287 out_err_noserver:
2288         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2289         return error;
2290
2291 error_splat_super:
2292         deactivate_locked_super(s);
2293         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2294         return error;
2295 }
2296
2297 #ifdef CONFIG_NFS_V4
2298
2299 /*
2300  * Finish setting up a cloned NFS4 superblock
2301  */
2302 static void nfs4_clone_super(struct super_block *sb,
2303                             const struct super_block *old_sb)
2304 {
2305         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2306         sb->s_blocksize = old_sb->s_blocksize;
2307         sb->s_maxbytes = old_sb->s_maxbytes;
2308         sb->s_time_gran = 1;
2309         sb->s_op = old_sb->s_op;
2310         nfs_initialise_sb(sb);
2311 }
2312
2313 /*
2314  * Set up an NFS4 superblock
2315  */
2316 static void nfs4_fill_super(struct super_block *sb)
2317 {
2318         sb->s_time_gran = 1;
2319         sb->s_op = &nfs4_sops;
2320         nfs_initialise_sb(sb);
2321 }
2322
2323 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2324 {
2325         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2326 }
2327
2328 static int nfs4_validate_text_mount_data(void *options,
2329                                          struct nfs_parsed_mount_data *args,
2330                                          const char *dev_name)
2331 {
2332         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2333
2334         nfs_set_default_port(sap, args->nfs_server.port, NFS_PORT);
2335
2336         nfs_validate_transport_protocol(args);
2337
2338         nfs4_validate_mount_flags(args);
2339
2340         if (args->version != 4) {
2341                 dfprintk(MOUNT,
2342                          "NFS4: Illegal mount version\n");
2343                 return -EINVAL;
2344         }
2345
2346         if (args->auth_flavor_len > 1) {
2347                 dfprintk(MOUNT,
2348                          "NFS4: Too many RPC auth flavours specified\n");
2349                 return -EINVAL;
2350         }
2351
2352         if (args->client_address == NULL) {
2353                 dfprintk(MOUNT,
2354                          "NFS4: mount program didn't pass callback address\n");
2355                 return -EINVAL;
2356         }
2357
2358         return nfs_parse_devname(dev_name,
2359                                    &args->nfs_server.hostname,
2360                                    NFS4_MAXNAMLEN,
2361                                    &args->nfs_server.export_path,
2362                                    NFS4_MAXPATHLEN);
2363 }
2364
2365 /*
2366  * Validate NFSv4 mount options
2367  */
2368 static int nfs4_validate_mount_data(void *options,
2369                                     struct nfs_parsed_mount_data *args,
2370                                     const char *dev_name)
2371 {
2372         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2373         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2374         char *c;
2375
2376         if (data == NULL)
2377                 goto out_no_data;
2378
2379         switch (data->version) {
2380         case 1:
2381                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2382                         goto out_no_address;
2383                 if (data->host_addrlen == 0)
2384                         goto out_no_address;
2385                 args->nfs_server.addrlen = data->host_addrlen;
2386                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2387                         return -EFAULT;
2388                 if (!nfs_verify_server_address(sap))
2389                         goto out_no_address;
2390
2391                 if (data->auth_flavourlen) {
2392                         if (data->auth_flavourlen > 1)
2393                                 goto out_inval_auth;
2394                         if (copy_from_user(&args->auth_flavors[0],
2395                                            data->auth_flavours,
2396                                            sizeof(args->auth_flavors[0])))
2397                                 return -EFAULT;
2398                 }
2399
2400                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2401                 if (IS_ERR(c))
2402                         return PTR_ERR(c);
2403                 args->nfs_server.hostname = c;
2404
2405                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2406                 if (IS_ERR(c))
2407                         return PTR_ERR(c);
2408                 args->nfs_server.export_path = c;
2409                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2410
2411                 c = strndup_user(data->client_addr.data, 16);
2412                 if (IS_ERR(c))
2413                         return PTR_ERR(c);
2414                 args->client_address = c;
2415
2416                 /*
2417                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2418                  * can deal with.
2419                  */
2420
2421                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2422                 args->rsize     = data->rsize;
2423                 args->wsize     = data->wsize;
2424                 args->timeo     = data->timeo;
2425                 args->retrans   = data->retrans;
2426                 args->acregmin  = data->acregmin;
2427                 args->acregmax  = data->acregmax;
2428                 args->acdirmin  = data->acdirmin;
2429                 args->acdirmax  = data->acdirmax;
2430                 args->nfs_server.protocol = data->proto;
2431                 nfs_validate_transport_protocol(args);
2432
2433                 break;
2434         default:
2435                 if (nfs_parse_mount_options((char *)options, args) == 0)
2436                         return -EINVAL;
2437
2438                 if (!nfs_verify_server_address(sap))
2439                         return -EINVAL;
2440
2441                 return nfs4_validate_text_mount_data(options, args, dev_name);
2442         }
2443
2444         return 0;
2445
2446 out_no_data:
2447         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2448         return -EINVAL;
2449
2450 out_inval_auth:
2451         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2452                  data->auth_flavourlen);
2453         return -EINVAL;
2454
2455 out_no_address:
2456         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2457         return -EINVAL;
2458 }
2459
2460 /*
2461  * Get the superblock for the NFS4 root partition
2462  */
2463 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2464         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2465 {
2466         struct nfs_parsed_mount_data *data = raw_data;
2467         struct super_block *s;
2468         struct nfs_server *server;
2469         struct nfs_fh *mntfh;
2470         struct dentry *mntroot;
2471         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2472         struct nfs_sb_mountdata sb_mntdata = {
2473                 .mntflags = flags,
2474         };
2475         int error = -ENOMEM;
2476
2477         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2478         if (data == NULL || mntfh == NULL)
2479                 goto out_free_fh;
2480
2481         security_init_mnt_opts(&data->lsm_opts);
2482
2483         /* Get a volume representation */
2484         server = nfs4_create_server(data, mntfh);
2485         if (IS_ERR(server)) {
2486                 error = PTR_ERR(server);
2487                 goto out;
2488         }
2489         sb_mntdata.server = server;
2490
2491         if (server->flags & NFS4_MOUNT_UNSHARED)
2492                 compare_super = NULL;
2493
2494         /* Get a superblock - note that we may end up sharing one that already exists */
2495         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2496         if (IS_ERR(s)) {
2497                 error = PTR_ERR(s);
2498                 goto out_free;
2499         }
2500
2501         if (s->s_fs_info != server) {
2502                 nfs_free_server(server);
2503                 server = NULL;
2504         } else {
2505                 error = nfs_bdi_register(server);
2506                 if (error)
2507                         goto error_splat_super;
2508         }
2509
2510         if (!s->s_root) {
2511                 /* initial superblock/root creation */
2512                 nfs4_fill_super(s);
2513                 nfs_fscache_get_super_cookie(
2514                         s, data ? data->fscache_uniq : NULL, NULL);
2515         }
2516
2517         mntroot = nfs4_get_root(s, mntfh);
2518         if (IS_ERR(mntroot)) {
2519                 error = PTR_ERR(mntroot);
2520                 goto error_splat_super;
2521         }
2522
2523         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2524         if (error)
2525                 goto error_splat_root;
2526
2527         s->s_flags |= MS_ACTIVE;
2528         mnt->mnt_sb = s;
2529         mnt->mnt_root = mntroot;
2530         error = 0;
2531
2532 out:
2533         security_free_mnt_opts(&data->lsm_opts);
2534 out_free_fh:
2535         kfree(mntfh);
2536         return error;
2537
2538 out_free:
2539         nfs_free_server(server);
2540         goto out;
2541
2542 error_splat_root:
2543         dput(mntroot);
2544 error_splat_super:
2545         deactivate_locked_super(s);
2546         goto out;
2547 }
2548
2549 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2550                 int flags, void *data, const char *hostname)
2551 {
2552         struct vfsmount *root_mnt;
2553         char *root_devname;
2554         size_t len;
2555
2556         len = strlen(hostname) + 3;
2557         root_devname = kmalloc(len, GFP_KERNEL);
2558         if (root_devname == NULL)
2559                 return ERR_PTR(-ENOMEM);
2560         snprintf(root_devname, len, "%s:/", hostname);
2561         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2562         kfree(root_devname);
2563         return root_mnt;
2564 }
2565
2566 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2567 {
2568         char *page = (char *) __get_free_page(GFP_KERNEL);
2569         char *devname, *tmp;
2570
2571         if (page == NULL)
2572                 return;
2573         devname = nfs_path(path->mnt->mnt_devname,
2574                         path->mnt->mnt_root, path->dentry,
2575                         page, PAGE_SIZE);
2576         if (devname == NULL)
2577                 goto out_freepage;
2578         tmp = kstrdup(devname, GFP_KERNEL);
2579         if (tmp == NULL)
2580                 goto out_freepage;
2581         kfree(mnt->mnt_devname);
2582         mnt->mnt_devname = tmp;
2583 out_freepage:
2584         free_page((unsigned long)page);
2585 }
2586
2587 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2588                 const char *export_path, struct vfsmount *mnt_target)
2589 {
2590         struct mnt_namespace *ns_private;
2591         struct nameidata nd;
2592         struct super_block *s;
2593         int ret;
2594
2595         ns_private = create_mnt_ns(root_mnt);
2596         ret = PTR_ERR(ns_private);
2597         if (IS_ERR(ns_private))
2598                 goto out_mntput;
2599
2600         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2601                         export_path, LOOKUP_FOLLOW, &nd);
2602
2603         put_mnt_ns(ns_private);
2604
2605         if (ret != 0)
2606                 goto out_err;
2607
2608         s = nd.path.mnt->mnt_sb;
2609         atomic_inc(&s->s_active);
2610         mnt_target->mnt_sb = s;
2611         mnt_target->mnt_root = dget(nd.path.dentry);
2612
2613         /* Correct the device pathname */
2614         nfs_fix_devname(&nd.path, mnt_target);
2615
2616         path_put(&nd.path);
2617         down_write(&s->s_umount);
2618         return 0;
2619 out_mntput:
2620         mntput(root_mnt);
2621 out_err:
2622         return ret;
2623 }
2624
2625 static int nfs4_try_mount(int flags, const char *dev_name,
2626                          struct nfs_parsed_mount_data *data,
2627                          struct vfsmount *mnt)
2628 {
2629         char *export_path;
2630         struct vfsmount *root_mnt;
2631         int error;
2632
2633         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2634
2635         export_path = data->nfs_server.export_path;
2636         data->nfs_server.export_path = "/";
2637         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2638                         data->nfs_server.hostname);
2639         data->nfs_server.export_path = export_path;
2640
2641         error = PTR_ERR(root_mnt);
2642         if (IS_ERR(root_mnt))
2643                 goto out;
2644
2645         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2646
2647 out:
2648         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2649                         error != 0 ? " [error]" : "");
2650         return error;
2651 }
2652
2653 /*
2654  * Get the superblock for an NFS4 mountpoint
2655  */
2656 static int nfs4_get_sb(struct file_system_type *fs_type,
2657         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2658 {
2659         struct nfs_parsed_mount_data *data;
2660         int error = -ENOMEM;
2661
2662         data = nfs_alloc_parsed_mount_data(4);
2663         if (data == NULL)
2664                 goto out_free_data;
2665
2666         /* Validate the mount data */
2667         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2668         if (error < 0)
2669                 goto out;
2670
2671         error = nfs4_try_mount(flags, dev_name, data, mnt);
2672
2673 out:
2674         kfree(data->client_address);
2675         kfree(data->nfs_server.export_path);
2676         kfree(data->nfs_server.hostname);
2677         kfree(data->fscache_uniq);
2678 out_free_data:
2679         kfree(data);
2680         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2681                         error != 0 ? " [error]" : "");
2682         return error;
2683 }
2684
2685 static void nfs4_kill_super(struct super_block *sb)
2686 {
2687         struct nfs_server *server = NFS_SB(sb);
2688
2689         dprintk("--> %s\n", __func__);
2690         nfs_super_return_all_delegations(sb);
2691         kill_anon_super(sb);
2692         nfs4_renewd_prepare_shutdown(server);
2693         nfs_fscache_release_super_cookie(sb);
2694         nfs_free_server(server);
2695         dprintk("<-- %s\n", __func__);
2696 }
2697
2698 /*
2699  * Clone an NFS4 server record on xdev traversal (FSID-change)
2700  */
2701 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2702                             const char *dev_name, void *raw_data,
2703                             struct vfsmount *mnt)
2704 {
2705         struct nfs_clone_mount *data = raw_data;
2706         struct super_block *s;
2707         struct nfs_server *server;
2708         struct dentry *mntroot;
2709         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2710         struct nfs_sb_mountdata sb_mntdata = {
2711                 .mntflags = flags,
2712         };
2713         int error;
2714
2715         dprintk("--> nfs4_xdev_get_sb()\n");
2716
2717         /* create a new volume representation */
2718         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2719         if (IS_ERR(server)) {
2720                 error = PTR_ERR(server);
2721                 goto out_err_noserver;
2722         }
2723         sb_mntdata.server = server;
2724
2725         if (server->flags & NFS4_MOUNT_UNSHARED)
2726                 compare_super = NULL;
2727
2728         /* Get a superblock - note that we may end up sharing one that already exists */
2729         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2730         if (IS_ERR(s)) {
2731                 error = PTR_ERR(s);
2732                 goto out_err_nosb;
2733         }
2734
2735         if (s->s_fs_info != server) {
2736                 nfs_free_server(server);
2737                 server = NULL;
2738         } else {
2739                 error = nfs_bdi_register(server);
2740                 if (error)
2741                         goto error_splat_super;
2742         }
2743
2744         if (!s->s_root) {
2745                 /* initial superblock/root creation */
2746                 nfs4_clone_super(s, data->sb);
2747                 nfs_fscache_get_super_cookie(s, NULL, data);
2748         }
2749
2750         mntroot = nfs4_get_root(s, data->fh);
2751         if (IS_ERR(mntroot)) {
2752                 error = PTR_ERR(mntroot);
2753                 goto error_splat_super;
2754         }
2755         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2756                 dput(mntroot);
2757                 error = -ESTALE;
2758                 goto error_splat_super;
2759         }
2760
2761         s->s_flags |= MS_ACTIVE;
2762         mnt->mnt_sb = s;
2763         mnt->mnt_root = mntroot;
2764
2765         security_sb_clone_mnt_opts(data->sb, s);
2766
2767         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2768         return 0;
2769
2770 out_err_nosb:
2771         nfs_free_server(server);
2772 out_err_noserver:
2773         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2774         return error;
2775
2776 error_splat_super:
2777         deactivate_locked_super(s);
2778         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2779         return error;
2780 }
2781
2782 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2783                 int flags, const char *dev_name, void *raw_data,
2784                 struct vfsmount *mnt)
2785 {
2786         struct nfs_clone_mount *data = raw_data;
2787         struct super_block *s;
2788         struct nfs_server *server;
2789         struct dentry *mntroot;
2790         struct nfs_fh mntfh;
2791         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2792         struct nfs_sb_mountdata sb_mntdata = {
2793                 .mntflags = flags,
2794         };
2795         int error;
2796
2797         dprintk("--> nfs4_referral_get_sb()\n");
2798
2799         /* create a new volume representation */
2800         server = nfs4_create_referral_server(data, &mntfh);
2801         if (IS_ERR(server)) {
2802                 error = PTR_ERR(server);
2803                 goto out_err_noserver;
2804         }
2805         sb_mntdata.server = server;
2806
2807         if (server->flags & NFS4_MOUNT_UNSHARED)
2808                 compare_super = NULL;
2809
2810         /* Get a superblock - note that we may end up sharing one that already exists */
2811         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2812         if (IS_ERR(s)) {
2813                 error = PTR_ERR(s);
2814                 goto out_err_nosb;
2815         }
2816
2817         if (s->s_fs_info != server) {
2818                 nfs_free_server(server);
2819                 server = NULL;
2820         } else {
2821                 error = nfs_bdi_register(server);
2822                 if (error)
2823                         goto error_splat_super;
2824         }
2825
2826         if (!s->s_root) {
2827                 /* initial superblock/root creation */
2828                 nfs4_fill_super(s);
2829                 nfs_fscache_get_super_cookie(s, NULL, data);
2830         }
2831
2832         mntroot = nfs4_get_root(s, &mntfh);
2833         if (IS_ERR(mntroot)) {
2834                 error = PTR_ERR(mntroot);
2835                 goto error_splat_super;
2836         }
2837         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2838                 dput(mntroot);
2839                 error = -ESTALE;
2840                 goto error_splat_super;
2841         }
2842
2843         s->s_flags |= MS_ACTIVE;
2844         mnt->mnt_sb = s;
2845         mnt->mnt_root = mntroot;
2846
2847         security_sb_clone_mnt_opts(data->sb, s);
2848
2849         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2850         return 0;
2851
2852 out_err_nosb:
2853         nfs_free_server(server);
2854 out_err_noserver:
2855         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2856         return error;
2857
2858 error_splat_super:
2859         deactivate_locked_super(s);
2860         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2861         return error;
2862 }
2863
2864 /*
2865  * Create an NFS4 server record on referral traversal
2866  */
2867 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2868                 int flags, const char *dev_name, void *raw_data,
2869                 struct vfsmount *mnt)
2870 {
2871         struct nfs_clone_mount *data = raw_data;
2872         char *export_path;
2873         struct vfsmount *root_mnt;
2874         int error;
2875
2876         dprintk("--> nfs4_referral_get_sb()\n");
2877
2878         export_path = data->mnt_path;
2879         data->mnt_path = "/";
2880
2881         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2882                         flags, data, data->hostname);
2883         data->mnt_path = export_path;
2884
2885         error = PTR_ERR(root_mnt);
2886         if (IS_ERR(root_mnt))
2887                 goto out;
2888
2889         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2890 out:
2891         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2892                         error != 0 ? " [error]" : "");
2893         return error;
2894 }
2895
2896 #endif /* CONFIG_NFS_V4 */