fs/nfs/super.c

   1 /*
   2  *  linux/fs/nfs/super.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  *  Split from inode.c by David Howells <dhowells@redhat.com>
  15  *
  16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17  *   particular server are held in the same superblock
  18  * - NFS superblocks can have several effective roots to the dentry tree
  19  * - directory type roots are spliced into the tree when a path from one root reaches the root
  20  *   of another (see nfs_lookup())
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/time.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/unistd.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/stats.h>
  35 #include <linux/sunrpc/metrics.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/sunrpc/xprtrdma.h>
  38 #include <linux/nfs_fs.h>
  39 #include <linux/nfs_mount.h>
  40 #include <linux/nfs4_mount.h>
  41 #include <linux/lockd/bind.h>
  42 #include <linux/seq_file.h>
  43 #include <linux/mount.h>
  44 #include <linux/mnt_namespace.h>
  45 #include <linux/namei.h>
  46 #include <linux/nfs_idmap.h>
  47 #include <linux/vfs.h>
  48 #include <linux/inet.h>
  49 #include <linux/in6.h>
  50 #include <linux/slab.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 #include "pnfs.h"
  67
  68 #define NFSDBG_FACILITY         NFSDBG_VFS
  69
  70 #ifdef CONFIG_NFS_V3
  71 #define NFS_DEFAULT_VERSION 3
  72 #else
  73 #define NFS_DEFAULT_VERSION 2
  74 #endif
  75
  76 enum {
  77         /* Mount options that take no arguments */
  78         Opt_soft, Opt_hard,
  79         Opt_posix, Opt_noposix,
  80         Opt_cto, Opt_nocto,
  81         Opt_ac, Opt_noac,
  82         Opt_lock, Opt_nolock,
  83         Opt_v2, Opt_v3, Opt_v4,
  84         Opt_udp, Opt_tcp, Opt_rdma,
  85         Opt_acl, Opt_noacl,
  86         Opt_rdirplus, Opt_nordirplus,
  87         Opt_sharecache, Opt_nosharecache,
  88         Opt_resvport, Opt_noresvport,
  89         Opt_fscache, Opt_nofscache,
  90
  91         /* Mount options that take integer arguments */
  92         Opt_port,
  93         Opt_rsize, Opt_wsize, Opt_bsize,
  94         Opt_timeo, Opt_retrans,
  95         Opt_acregmin, Opt_acregmax,
  96         Opt_acdirmin, Opt_acdirmax,
  97         Opt_actimeo,
  98         Opt_namelen,
  99         Opt_mountport,
 100         Opt_mountvers,
 101         Opt_nfsvers,
 102         Opt_minorversion,
 103
 104         /* Mount options that take string arguments */
 105         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 106         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 107         Opt_lookupcache,
 108         Opt_fscache_uniq,
 109         Opt_local_lock,
 110
 111         /* Special mount options */
 112         Opt_userspace, Opt_deprecated, Opt_sloppy,
 113
 114         Opt_err
 115 };
 116
 117 static const match_table_t nfs_mount_option_tokens = {
 118         { Opt_userspace, "bg" },
 119         { Opt_userspace, "fg" },
 120         { Opt_userspace, "retry=%s" },
 121
 122         { Opt_sloppy, "sloppy" },
 123
 124         { Opt_soft, "soft" },
 125         { Opt_hard, "hard" },
 126         { Opt_deprecated, "intr" },
 127         { Opt_deprecated, "nointr" },
 128         { Opt_posix, "posix" },
 129         { Opt_noposix, "noposix" },
 130         { Opt_cto, "cto" },
 131         { Opt_nocto, "nocto" },
 132         { Opt_ac, "ac" },
 133         { Opt_noac, "noac" },
 134         { Opt_lock, "lock" },
 135         { Opt_nolock, "nolock" },
 136         { Opt_v2, "v2" },
 137         { Opt_v3, "v3" },
 138         { Opt_v4, "v4" },
 139         { Opt_udp, "udp" },
 140         { Opt_tcp, "tcp" },
 141         { Opt_rdma, "rdma" },
 142         { Opt_acl, "acl" },
 143         { Opt_noacl, "noacl" },
 144         { Opt_rdirplus, "rdirplus" },
 145         { Opt_nordirplus, "nordirplus" },
 146         { Opt_sharecache, "sharecache" },
 147         { Opt_nosharecache, "nosharecache" },
 148         { Opt_resvport, "resvport" },
 149         { Opt_noresvport, "noresvport" },
 150         { Opt_fscache, "fsc" },
 151         { Opt_nofscache, "nofsc" },
 152
 153         { Opt_port, "port=%s" },
 154         { Opt_rsize, "rsize=%s" },
 155         { Opt_wsize, "wsize=%s" },
 156         { Opt_bsize, "bsize=%s" },
 157         { Opt_timeo, "timeo=%s" },
 158         { Opt_retrans, "retrans=%s" },
 159         { Opt_acregmin, "acregmin=%s" },
 160         { Opt_acregmax, "acregmax=%s" },
 161         { Opt_acdirmin, "acdirmin=%s" },
 162         { Opt_acdirmax, "acdirmax=%s" },
 163         { Opt_actimeo, "actimeo=%s" },
 164         { Opt_namelen, "namlen=%s" },
 165         { Opt_mountport, "mountport=%s" },
 166         { Opt_mountvers, "mountvers=%s" },
 167         { Opt_nfsvers, "nfsvers=%s" },
 168         { Opt_nfsvers, "vers=%s" },
 169         { Opt_minorversion, "minorversion=%s" },
 170
 171         { Opt_sec, "sec=%s" },
 172         { Opt_proto, "proto=%s" },
 173         { Opt_mountproto, "mountproto=%s" },
 174         { Opt_addr, "addr=%s" },
 175         { Opt_clientaddr, "clientaddr=%s" },
 176         { Opt_mounthost, "mounthost=%s" },
 177         { Opt_mountaddr, "mountaddr=%s" },
 178
 179         { Opt_lookupcache, "lookupcache=%s" },
 180         { Opt_fscache_uniq, "fsc=%s" },
 181         { Opt_local_lock, "local_lock=%s" },
 182
 183         { Opt_err, NULL }
 184 };
 185
 186 enum {
 187         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 188
 189         Opt_xprt_err
 190 };
 191
 192 static const match_table_t nfs_xprt_protocol_tokens = {
 193         { Opt_xprt_udp, "udp" },
 194         { Opt_xprt_udp6, "udp6" },
 195         { Opt_xprt_tcp, "tcp" },
 196         { Opt_xprt_tcp6, "tcp6" },
 197         { Opt_xprt_rdma, "rdma" },
 198
 199         { Opt_xprt_err, NULL }
 200 };
 201
 202 enum {
 203         Opt_sec_none, Opt_sec_sys,
 204         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 205         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 206         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 207
 208         Opt_sec_err
 209 };
 210
 211 static const match_table_t nfs_secflavor_tokens = {
 212         { Opt_sec_none, "none" },
 213         { Opt_sec_none, "null" },
 214         { Opt_sec_sys, "sys" },
 215
 216         { Opt_sec_krb5, "krb5" },
 217         { Opt_sec_krb5i, "krb5i" },
 218         { Opt_sec_krb5p, "krb5p" },
 219
 220         { Opt_sec_lkey, "lkey" },
 221         { Opt_sec_lkeyi, "lkeyi" },
 222         { Opt_sec_lkeyp, "lkeyp" },
 223
 224         { Opt_sec_spkm, "spkm3" },
 225         { Opt_sec_spkmi, "spkm3i" },
 226         { Opt_sec_spkmp, "spkm3p" },
 227
 228         { Opt_sec_err, NULL }
 229 };
 230
 231 enum {
 232         Opt_lookupcache_all, Opt_lookupcache_positive,
 233         Opt_lookupcache_none,
 234
 235         Opt_lookupcache_err
 236 };
 237
 238 static match_table_t nfs_lookupcache_tokens = {
 239         { Opt_lookupcache_all, "all" },
 240         { Opt_lookupcache_positive, "pos" },
 241         { Opt_lookupcache_positive, "positive" },
 242         { Opt_lookupcache_none, "none" },
 243
 244         { Opt_lookupcache_err, NULL }
 245 };
 246
 247 enum {
 248         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 249         Opt_local_lock_none,
 250
 251         Opt_local_lock_err
 252 };
 253
 254 static match_table_t nfs_local_lock_tokens = {
 255         { Opt_local_lock_all, "all" },
 256         { Opt_local_lock_flock, "flock" },
 257         { Opt_local_lock_posix, "posix" },
 258         { Opt_local_lock_none, "none" },
 259
 260         { Opt_local_lock_err, NULL }
 261 };
 262
 263
 264 static void nfs_umount_begin(struct super_block *);
 265 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 266 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
 267 static int  nfs_show_devname(struct seq_file *, struct vfsmount *);
 268 static int  nfs_show_path(struct seq_file *, struct vfsmount *);
 269 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 270 static struct dentry *nfs_fs_mount(struct file_system_type *,
 271                 int, const char *, void *);
 272 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 273                 int flags, const char *dev_name, void *raw_data);
 274 static void nfs_put_super(struct super_block *);
 275 static void nfs_kill_super(struct super_block *);
 276 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 277
 278 static struct file_system_type nfs_fs_type = {
 279         .owner          = THIS_MODULE,
 280         .name           = "nfs",
 281         .mount          = nfs_fs_mount,
 282         .kill_sb        = nfs_kill_super,
 283         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 284 };
 285
 286 struct file_system_type nfs_xdev_fs_type = {
 287         .owner          = THIS_MODULE,
 288         .name           = "nfs",
 289         .mount          = nfs_xdev_mount,
 290         .kill_sb        = nfs_kill_super,
 291         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 292 };
 293
 294 static const struct super_operations nfs_sops = {
 295         .alloc_inode    = nfs_alloc_inode,
 296         .destroy_inode  = nfs_destroy_inode,
 297         .write_inode    = nfs_write_inode,
 298         .put_super      = nfs_put_super,
 299         .statfs         = nfs_statfs,
 300         .evict_inode    = nfs_evict_inode,
 301         .umount_begin   = nfs_umount_begin,
 302         .show_options   = nfs_show_options,
 303         .show_devname   = nfs_show_devname,
 304         .show_path      = nfs_show_path,
 305         .show_stats     = nfs_show_stats,
 306         .remount_fs     = nfs_remount,
 307 };
 308
 309 #ifdef CONFIG_NFS_V4
 310 static int nfs4_validate_text_mount_data(void *options,
 311         struct nfs_parsed_mount_data *args, const char *dev_name);
 312 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 313         struct nfs_parsed_mount_data *data);
 314 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
 315         int flags, const char *dev_name, void *raw_data);
 316 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 317         int flags, const char *dev_name, void *raw_data);
 318 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
 319         int flags, const char *dev_name, void *raw_data);
 320 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 321         int flags, const char *dev_name, void *raw_data);
 322 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 323         int flags, const char *dev_name, void *raw_data);
 324 static void nfs4_kill_super(struct super_block *sb);
 325
 326 static struct file_system_type nfs4_fs_type = {
 327         .owner          = THIS_MODULE,
 328         .name           = "nfs4",
 329         .mount          = nfs4_mount,
 330         .kill_sb        = nfs4_kill_super,
 331         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 332 };
 333
 334 static struct file_system_type nfs4_remote_fs_type = {
 335         .owner          = THIS_MODULE,
 336         .name           = "nfs4",
 337         .mount          = nfs4_remote_mount,
 338         .kill_sb        = nfs4_kill_super,
 339         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 340 };
 341
 342 struct file_system_type nfs4_xdev_fs_type = {
 343         .owner          = THIS_MODULE,
 344         .name           = "nfs4",
 345         .mount          = nfs4_xdev_mount,
 346         .kill_sb        = nfs4_kill_super,
 347         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 348 };
 349
 350 static struct file_system_type nfs4_remote_referral_fs_type = {
 351         .owner          = THIS_MODULE,
 352         .name           = "nfs4",
 353         .mount          = nfs4_remote_referral_mount,
 354         .kill_sb        = nfs4_kill_super,
 355         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 356 };
 357
 358 struct file_system_type nfs4_referral_fs_type = {
 359         .owner          = THIS_MODULE,
 360         .name           = "nfs4",
 361         .mount          = nfs4_referral_mount,
 362         .kill_sb        = nfs4_kill_super,
 363         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 364 };
 365
 366 static const struct super_operations nfs4_sops = {
 367         .alloc_inode    = nfs_alloc_inode,
 368         .destroy_inode  = nfs_destroy_inode,
 369         .write_inode    = nfs_write_inode,
 370         .put_super      = nfs_put_super,
 371         .statfs         = nfs_statfs,
 372         .evict_inode    = nfs4_evict_inode,
 373         .umount_begin   = nfs_umount_begin,
 374         .show_options   = nfs_show_options,
 375         .show_devname   = nfs_show_devname,
 376         .show_path      = nfs_show_path,
 377         .show_stats     = nfs_show_stats,
 378         .remount_fs     = nfs_remount,
 379 };
 380 #endif
 381
 382 static struct shrinker acl_shrinker = {
 383         .shrink         = nfs_access_cache_shrinker,
 384         .seeks          = DEFAULT_SEEKS,
 385 };
 386
 387 /*
 388  * Register the NFS filesystems
 389  */
 390 int __init register_nfs_fs(void)
 391 {
 392         int ret;
 393
 394         ret = register_filesystem(&nfs_fs_type);
 395         if (ret < 0)
 396                 goto error_0;
 397
 398         ret = nfs_register_sysctl();
 399         if (ret < 0)
 400                 goto error_1;
 401 #ifdef CONFIG_NFS_V4
 402         ret = register_filesystem(&nfs4_fs_type);
 403         if (ret < 0)
 404                 goto error_2;
 405 #endif
 406         register_shrinker(&acl_shrinker);
 407         return 0;
 408
 409 #ifdef CONFIG_NFS_V4
 410 error_2:
 411         nfs_unregister_sysctl();
 412 #endif
 413 error_1:
 414         unregister_filesystem(&nfs_fs_type);
 415 error_0:
 416         return ret;
 417 }
 418
 419 /*
 420  * Unregister the NFS filesystems
 421  */
 422 void __exit unregister_nfs_fs(void)
 423 {
 424         unregister_shrinker(&acl_shrinker);
 425 #ifdef CONFIG_NFS_V4
 426         unregister_filesystem(&nfs4_fs_type);
 427 #endif
 428         nfs_unregister_sysctl();
 429         unregister_filesystem(&nfs_fs_type);
 430 }
 431
 432 void nfs_sb_active(struct super_block *sb)
 433 {
 434         struct nfs_server *server = NFS_SB(sb);
 435
 436         if (atomic_inc_return(&server->active) == 1)
 437                 atomic_inc(&sb->s_active);
 438 }
 439
 440 void nfs_sb_deactive(struct super_block *sb)
 441 {
 442         struct nfs_server *server = NFS_SB(sb);
 443
 444         if (atomic_dec_and_test(&server->active))
 445                 deactivate_super(sb);
 446 }
 447
 448 /*
 449  * Deliver file system statistics to userspace
 450  */
 451 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 452 {
 453         struct nfs_server *server = NFS_SB(dentry->d_sb);
 454         unsigned char blockbits;
 455         unsigned long blockres;
 456         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 457         struct nfs_fsstat res;
 458         int error = -ENOMEM;
 459
 460         res.fattr = nfs_alloc_fattr();
 461         if (res.fattr == NULL)
 462                 goto out_err;
 463
 464         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 465         if (unlikely(error == -ESTALE)) {
 466                 struct dentry *pd_dentry;
 467
 468                 pd_dentry = dget_parent(dentry);
 469                 if (pd_dentry != NULL) {
 470                         nfs_zap_caches(pd_dentry->d_inode);
 471                         dput(pd_dentry);
 472                 }
 473         }
 474         nfs_free_fattr(res.fattr);
 475         if (error < 0)
 476                 goto out_err;
 477
 478         buf->f_type = NFS_SUPER_MAGIC;
 479
 480         /*
 481          * Current versions of glibc do not correctly handle the
 482          * case where f_frsize != f_bsize.  Eventually we want to
 483          * report the value of wtmult in this field.
 484          */
 485         buf->f_frsize = dentry->d_sb->s_blocksize;
 486
 487         /*
 488          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 489          * are reported in units of f_frsize.  Linux hasn't had
 490          * an f_frsize field in its statfs struct until recently,
 491          * thus historically Linux's sys_statfs reports these
 492          * fields in units of f_bsize.
 493          */
 494         buf->f_bsize = dentry->d_sb->s_blocksize;
 495         blockbits = dentry->d_sb->s_blocksize_bits;
 496         blockres = (1 << blockbits) - 1;
 497         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 498         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 499         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 500
 501         buf->f_files = res.tfiles;
 502         buf->f_ffree = res.afiles;
 503
 504         buf->f_namelen = server->namelen;
 505
 506         return 0;
 507
 508  out_err:
 509         dprintk("%s: statfs error = %d\n", __func__, -error);
 510         return error;
 511 }
 512
 513 /*
 514  * Map the security flavour number to a name
 515  */
 516 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 517 {
 518         static const struct {
 519                 rpc_authflavor_t flavour;
 520                 const char *str;
 521         } sec_flavours[] = {
 522                 { RPC_AUTH_NULL, "null" },
 523                 { RPC_AUTH_UNIX, "sys" },
 524                 { RPC_AUTH_GSS_KRB5, "krb5" },
 525                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 526                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 527                 { RPC_AUTH_GSS_LKEY, "lkey" },
 528                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 529                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 530                 { RPC_AUTH_GSS_SPKM, "spkm" },
 531                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 532                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 533                 { UINT_MAX, "unknown" }
 534         };
 535         int i;
 536
 537         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 538                 if (sec_flavours[i].flavour == flavour)
 539                         break;
 540         }
 541         return sec_flavours[i].str;
 542 }
 543
 544 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 545                                   int showdefaults)
 546 {
 547         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 548
 549         seq_printf(m, ",mountproto=");
 550         switch (sap->sa_family) {
 551         case AF_INET:
 552                 switch (nfss->mountd_protocol) {
 553                 case IPPROTO_UDP:
 554                         seq_printf(m, RPCBIND_NETID_UDP);
 555                         break;
 556                 case IPPROTO_TCP:
 557                         seq_printf(m, RPCBIND_NETID_TCP);
 558                         break;
 559                 default:
 560                         if (showdefaults)
 561                                 seq_printf(m, "auto");
 562                 }
 563                 break;
 564         case AF_INET6:
 565                 switch (nfss->mountd_protocol) {
 566                 case IPPROTO_UDP:
 567                         seq_printf(m, RPCBIND_NETID_UDP6);
 568                         break;
 569                 case IPPROTO_TCP:
 570                         seq_printf(m, RPCBIND_NETID_TCP6);
 571                         break;
 572                 default:
 573                         if (showdefaults)
 574                                 seq_printf(m, "auto");
 575                 }
 576                 break;
 577         default:
 578                 if (showdefaults)
 579                         seq_printf(m, "auto");
 580         }
 581 }
 582
 583 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 584                                     int showdefaults)
 585 {
 586         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 587
 588         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 589                 return;
 590
 591         switch (sap->sa_family) {
 592         case AF_INET: {
 593                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 594                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 595                 break;
 596         }
 597         case AF_INET6: {
 598                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 599                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 600                 break;
 601         }
 602         default:
 603                 if (showdefaults)
 604                         seq_printf(m, ",mountaddr=unspecified");
 605         }
 606
 607         if (nfss->mountd_version || showdefaults)
 608                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 609         if ((nfss->mountd_port &&
 610                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 611                 showdefaults)
 612                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 613
 614         nfs_show_mountd_netid(m, nfss, showdefaults);
 615 }
 616
 617 #ifdef CONFIG_NFS_V4
 618 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 619                                     int showdefaults)
 620 {
 621         struct nfs_client *clp = nfss->nfs_client;
 622
 623         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 624         seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
 625 }
 626 #else
 627 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 628                                     int showdefaults)
 629 {
 630 }
 631 #endif
 632
 633 /*
 634  * Describe the mount options in force on this server representation
 635  */
 636 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 637                                    int showdefaults)
 638 {
 639         static const struct proc_nfs_info {
 640                 int flag;
 641                 const char *str;
 642                 const char *nostr;
 643         } nfs_info[] = {
 644                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 645                 { NFS_MOUNT_POSIX, ",posix", "" },
 646                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 647                 { NFS_MOUNT_NOAC, ",noac", "" },
 648                 { NFS_MOUNT_NONLM, ",nolock", "" },
 649                 { NFS_MOUNT_NOACL, ",noacl", "" },
 650                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 651                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 652                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 653                 { 0, NULL, NULL }
 654         };
 655         const struct proc_nfs_info *nfs_infop;
 656         struct nfs_client *clp = nfss->nfs_client;
 657         u32 version = clp->rpc_ops->version;
 658         int local_flock, local_fcntl;
 659
 660         seq_printf(m, ",vers=%u", version);
 661         seq_printf(m, ",rsize=%u", nfss->rsize);
 662         seq_printf(m, ",wsize=%u", nfss->wsize);
 663         if (nfss->bsize != 0)
 664                 seq_printf(m, ",bsize=%u", nfss->bsize);
 665         seq_printf(m, ",namlen=%u", nfss->namelen);
 666         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 667                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 668         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 669                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 670         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 671                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 672         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 673                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 674         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 675                 if (nfss->flags & nfs_infop->flag)
 676                         seq_puts(m, nfs_infop->str);
 677                 else
 678                         seq_puts(m, nfs_infop->nostr);
 679         }
 680         seq_printf(m, ",proto=%s",
 681                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 682         if (version == 4) {
 683                 if (nfss->port != NFS_PORT)
 684                         seq_printf(m, ",port=%u", nfss->port);
 685         } else
 686                 if (nfss->port)
 687                         seq_printf(m, ",port=%u", nfss->port);
 688
 689         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 690         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 691         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 692
 693         if (version != 4)
 694                 nfs_show_mountd_options(m, nfss, showdefaults);
 695         else
 696                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 697
 698         if (nfss->options & NFS_OPTION_FSCACHE)
 699                 seq_printf(m, ",fsc");
 700
 701         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 702                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 703                         seq_printf(m, ",lookupcache=none");
 704                 else
 705                         seq_printf(m, ",lookupcache=pos");
 706         }
 707
 708         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 709         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 710
 711         if (!local_flock && !local_fcntl)
 712                 seq_printf(m, ",local_lock=none");
 713         else if (local_flock && local_fcntl)
 714                 seq_printf(m, ",local_lock=all");
 715         else if (local_flock)
 716                 seq_printf(m, ",local_lock=flock");
 717         else
 718                 seq_printf(m, ",local_lock=posix");
 719 }
 720
 721 /*
 722  * Describe the mount options on this VFS mountpoint
 723  */
 724 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 725 {
 726         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 727
 728         nfs_show_mount_options(m, nfss, 0);
 729
 730         seq_printf(m, ",addr=%s",
 731                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 732                                                         RPC_DISPLAY_ADDR));
 733
 734         return 0;
 735 }
 736
 737 #ifdef CONFIG_NFS_V4
 738 #ifdef CONFIG_NFS_V4_1
 739 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 740 {
 741         if (nfs4_has_session(server->nfs_client))
 742                 seq_printf(m, ",sessions");
 743 }
 744 #else
 745 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 746 #endif
 747 #endif
 748
 749 #ifdef CONFIG_NFS_V4
 750 #ifdef CONFIG_NFS_V4_1
 751 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 752 {
 753         seq_printf(m, ",pnfs=");
 754         if (server->pnfs_curr_ld)
 755                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 756         else
 757                 seq_printf(m, "not configured");
 758 }
 759 #else
 760 static void show_pnfs(struct seq_file *m, struct nfs_server *server) {}
 761 #endif
 762 #endif
 763
 764 static int nfs_show_devname(struct seq_file *m, struct vfsmount *mnt)
 765 {
 766         char *page = (char *) __get_free_page(GFP_KERNEL);
 767         char *devname, *dummy;
 768         int err = 0;
 769         if (!page)
 770                 return -ENOMEM;
 771         devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE);
 772         if (IS_ERR(devname))
 773                 err = PTR_ERR(devname);
 774         else
 775                 seq_escape(m, devname, " \t\n\\");
 776         free_page((unsigned long)page);
 777         return err;
 778 }
 779
 780 static int nfs_show_path(struct seq_file *m, struct vfsmount *mnt)
 781 {
 782         seq_puts(m, "/");
 783         return 0;
 784 }
 785
 786 /*
 787  * Present statistical information for this VFS mountpoint
 788  */
 789 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 790 {
 791         int i, cpu;
 792         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 793         struct rpc_auth *auth = nfss->client->cl_auth;
 794         struct nfs_iostats totals = { };
 795
 796         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 797
 798         /*
 799          * Display all mount option settings
 800          */
 801         seq_printf(m, "\n\topts:\t");
 802         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 803         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 804         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 805         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 806         nfs_show_mount_options(m, nfss, 1);
 807
 808         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 809
 810         seq_printf(m, "\n\tcaps:\t");
 811         seq_printf(m, "caps=0x%x", nfss->caps);
 812         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 813         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 814         seq_printf(m, ",bsize=%u", nfss->bsize);
 815         seq_printf(m, ",namlen=%u", nfss->namelen);
 816
 817 #ifdef CONFIG_NFS_V4
 818         if (nfss->nfs_client->rpc_ops->version == 4) {
 819                 seq_printf(m, "\n\tnfsv4:\t");
 820                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 821                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 822                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 823                 show_sessions(m, nfss);
 824                 show_pnfs(m, nfss);
 825         }
 826 #endif
 827
 828         /*
 829          * Display security flavor in effect for this mount
 830          */
 831         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 832         if (auth->au_flavor)
 833                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 834
 835         /*
 836          * Display superblock I/O counters
 837          */
 838         for_each_possible_cpu(cpu) {
 839                 struct nfs_iostats *stats;
 840
 841                 preempt_disable();
 842                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 843
 844                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 845                         totals.events[i] += stats->events[i];
 846                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 847                         totals.bytes[i] += stats->bytes[i];
 848 #ifdef CONFIG_NFS_FSCACHE
 849                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 850                         totals.fscache[i] += stats->fscache[i];
 851 #endif
 852
 853                 preempt_enable();
 854         }
 855
 856         seq_printf(m, "\n\tevents:\t");
 857         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 858                 seq_printf(m, "%lu ", totals.events[i]);
 859         seq_printf(m, "\n\tbytes:\t");
 860         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 861                 seq_printf(m, "%Lu ", totals.bytes[i]);
 862 #ifdef CONFIG_NFS_FSCACHE
 863         if (nfss->options & NFS_OPTION_FSCACHE) {
 864                 seq_printf(m, "\n\tfsc:\t");
 865                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 866                         seq_printf(m, "%Lu ", totals.bytes[i]);
 867         }
 868 #endif
 869         seq_printf(m, "\n");
 870
 871         rpc_print_iostats(m, nfss->client);
 872
 873         return 0;
 874 }
 875
 876 /*
 877  * Begin unmount by attempting to remove all automounted mountpoints we added
 878  * in response to xdev traversals and referrals
 879  */
 880 static void nfs_umount_begin(struct super_block *sb)
 881 {
 882         struct nfs_server *server;
 883         struct rpc_clnt *rpc;
 884
 885         server = NFS_SB(sb);
 886         /* -EIO all pending I/O */
 887         rpc = server->client_acl;
 888         if (!IS_ERR(rpc))
 889                 rpc_killall_tasks(rpc);
 890         rpc = server->client;
 891         if (!IS_ERR(rpc))
 892                 rpc_killall_tasks(rpc);
 893 }
 894
 895 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 896 {
 897         struct nfs_parsed_mount_data *data;
 898
 899         data = kzalloc(sizeof(*data), GFP_KERNEL);
 900         if (data) {
 901                 data->acregmin          = NFS_DEF_ACREGMIN;
 902                 data->acregmax          = NFS_DEF_ACREGMAX;
 903                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 904                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 905                 data->mount_server.port = NFS_UNSPEC_PORT;
 906                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 907                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 908                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 909                 data->auth_flavor_len   = 1;
 910                 data->version           = version;
 911                 data->minorversion      = 0;
 912         }
 913         return data;
 914 }
 915
 916 /*
 917  * Sanity-check a server address provided by the mount command.
 918  *
 919  * Address family must be initialized, and address must not be
 920  * the ANY address for that family.
 921  */
 922 static int nfs_verify_server_address(struct sockaddr *addr)
 923 {
 924         switch (addr->sa_family) {
 925         case AF_INET: {
 926                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 927                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 928         }
 929         case AF_INET6: {
 930                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 931                 return !ipv6_addr_any(sa);
 932         }
 933         }
 934
 935         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 936         return 0;
 937 }
 938
 939 /*
 940  * Select between a default port value and a user-specified port value.
 941  * If a zero value is set, then autobind will be used.
 942  */
 943 static void nfs_set_port(struct sockaddr *sap, int *port,
 944                                  const unsigned short default_port)
 945 {
 946         if (*port == NFS_UNSPEC_PORT)
 947                 *port = default_port;
 948
 949         rpc_set_port(sap, *port);
 950 }
 951
 952 /*
 953  * Sanity check the NFS transport protocol.
 954  *
 955  */
 956 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 957 {
 958         switch (mnt->nfs_server.protocol) {
 959         case XPRT_TRANSPORT_UDP:
 960         case XPRT_TRANSPORT_TCP:
 961         case XPRT_TRANSPORT_RDMA:
 962                 break;
 963         default:
 964                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 965         }
 966 }
 967
 968 /*
 969  * For text based NFSv2/v3 mounts, the mount protocol transport default
 970  * settings should depend upon the specified NFS transport.
 971  */
 972 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 973 {
 974         nfs_validate_transport_protocol(mnt);
 975
 976         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 977             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 978                         return;
 979         switch (mnt->nfs_server.protocol) {
 980         case XPRT_TRANSPORT_UDP:
 981                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 982                 break;
 983         case XPRT_TRANSPORT_TCP:
 984         case XPRT_TRANSPORT_RDMA:
 985                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 986         }
 987 }
 988
 989 /*
 990  * Parse the value of the 'sec=' option.
 991  */
 992 static int nfs_parse_security_flavors(char *value,
 993                                       struct nfs_parsed_mount_data *mnt)
 994 {
 995         substring_t args[MAX_OPT_ARGS];
 996
 997         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 998
 999         switch (match_token(value, nfs_secflavor_tokens, args)) {
1000         case Opt_sec_none:
1001                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1002                 break;
1003         case Opt_sec_sys:
1004                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1005                 break;
1006         case Opt_sec_krb5:
1007                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1008                 break;
1009         case Opt_sec_krb5i:
1010                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1011                 break;
1012         case Opt_sec_krb5p:
1013                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1014                 break;
1015         case Opt_sec_lkey:
1016                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1017                 break;
1018         case Opt_sec_lkeyi:
1019                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1020                 break;
1021         case Opt_sec_lkeyp:
1022                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1023                 break;
1024         case Opt_sec_spkm:
1025                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1026                 break;
1027         case Opt_sec_spkmi:
1028                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1029                 break;
1030         case Opt_sec_spkmp:
1031                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1032                 break;
1033         default:
1034                 return 0;
1035         }
1036
1037         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1038         mnt->auth_flavor_len = 1;
1039         return 1;
1040 }
1041
1042 static int nfs_get_option_str(substring_t args[], char **option)
1043 {
1044         kfree(*option);
1045         *option = match_strdup(args);
1046         return !option;
1047 }
1048
1049 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1050 {
1051         int rc;
1052         char *string;
1053
1054         string = match_strdup(args);
1055         if (string == NULL)
1056                 return -ENOMEM;
1057         rc = strict_strtoul(string, 10, option);
1058         kfree(string);
1059
1060         return rc;
1061 }
1062
1063 /*
1064  * Error-check and convert a string of mount options from user space into
1065  * a data structure.  The whole mount string is processed; bad options are
1066  * skipped as they are encountered.  If there were no errors, return 1;
1067  * otherwise return 0 (zero).
1068  */
1069 static int nfs_parse_mount_options(char *raw,
1070                                    struct nfs_parsed_mount_data *mnt)
1071 {
1072         char *p, *string, *secdata;
1073         int rc, sloppy = 0, invalid_option = 0;
1074         unsigned short protofamily = AF_UNSPEC;
1075         unsigned short mountfamily = AF_UNSPEC;
1076
1077         if (!raw) {
1078                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1079                 return 1;
1080         }
1081         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1082
1083         secdata = alloc_secdata();
1084         if (!secdata)
1085                 goto out_nomem;
1086
1087         rc = security_sb_copy_data(raw, secdata);
1088         if (rc)
1089                 goto out_security_failure;
1090
1091         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1092         if (rc)
1093                 goto out_security_failure;
1094
1095         free_secdata(secdata);
1096
1097         while ((p = strsep(&raw, ",")) != NULL) {
1098                 substring_t args[MAX_OPT_ARGS];
1099                 unsigned long option;
1100                 int token;
1101
1102                 if (!*p)
1103                         continue;
1104
1105                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1106
1107                 token = match_token(p, nfs_mount_option_tokens, args);
1108                 switch (token) {
1109
1110                 /*
1111                  * boolean options:  foo/nofoo
1112                  */
1113                 case Opt_soft:
1114                         mnt->flags |= NFS_MOUNT_SOFT;
1115                         break;
1116                 case Opt_hard:
1117                         mnt->flags &= ~NFS_MOUNT_SOFT;
1118                         break;
1119                 case Opt_posix:
1120                         mnt->flags |= NFS_MOUNT_POSIX;
1121                         break;
1122                 case Opt_noposix:
1123                         mnt->flags &= ~NFS_MOUNT_POSIX;
1124                         break;
1125                 case Opt_cto:
1126                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1127                         break;
1128                 case Opt_nocto:
1129                         mnt->flags |= NFS_MOUNT_NOCTO;
1130                         break;
1131                 case Opt_ac:
1132                         mnt->flags &= ~NFS_MOUNT_NOAC;
1133                         break;
1134                 case Opt_noac:
1135                         mnt->flags |= NFS_MOUNT_NOAC;
1136                         break;
1137                 case Opt_lock:
1138                         mnt->flags &= ~NFS_MOUNT_NONLM;
1139                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1140                                         NFS_MOUNT_LOCAL_FCNTL);
1141                         break;
1142                 case Opt_nolock:
1143                         mnt->flags |= NFS_MOUNT_NONLM;
1144                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1145                                        NFS_MOUNT_LOCAL_FCNTL);
1146                         break;
1147                 case Opt_v2:
1148                         mnt->flags &= ~NFS_MOUNT_VER3;
1149                         mnt->version = 2;
1150                         break;
1151                 case Opt_v3:
1152                         mnt->flags |= NFS_MOUNT_VER3;
1153                         mnt->version = 3;
1154                         break;
1155                 case Opt_v4:
1156                         mnt->flags &= ~NFS_MOUNT_VER3;
1157                         mnt->version = 4;
1158                         break;
1159                 case Opt_udp:
1160                         mnt->flags &= ~NFS_MOUNT_TCP;
1161                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1162                         break;
1163                 case Opt_tcp:
1164                         mnt->flags |= NFS_MOUNT_TCP;
1165                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1166                         break;
1167                 case Opt_rdma:
1168                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1169                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1170                         xprt_load_transport(p);
1171                         break;
1172                 case Opt_acl:
1173                         mnt->flags &= ~NFS_MOUNT_NOACL;
1174                         break;
1175                 case Opt_noacl:
1176                         mnt->flags |= NFS_MOUNT_NOACL;
1177                         break;
1178                 case Opt_rdirplus:
1179                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1180                         break;
1181                 case Opt_nordirplus:
1182                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1183                         break;
1184                 case Opt_sharecache:
1185                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1186                         break;
1187                 case Opt_nosharecache:
1188                         mnt->flags |= NFS_MOUNT_UNSHARED;
1189                         break;
1190                 case Opt_resvport:
1191                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1192                         break;
1193                 case Opt_noresvport:
1194                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1195                         break;
1196                 case Opt_fscache:
1197                         mnt->options |= NFS_OPTION_FSCACHE;
1198                         kfree(mnt->fscache_uniq);
1199                         mnt->fscache_uniq = NULL;
1200                         break;
1201                 case Opt_nofscache:
1202                         mnt->options &= ~NFS_OPTION_FSCACHE;
1203                         kfree(mnt->fscache_uniq);
1204                         mnt->fscache_uniq = NULL;
1205                         break;
1206
1207                 /*
1208                  * options that take numeric values
1209                  */
1210                 case Opt_port:
1211                         if (nfs_get_option_ul(args, &option) ||
1212                             option > USHRT_MAX)
1213                                 goto out_invalid_value;
1214                         mnt->nfs_server.port = option;
1215                         break;
1216                 case Opt_rsize:
1217                         if (nfs_get_option_ul(args, &option))
1218                                 goto out_invalid_value;
1219                         mnt->rsize = option;
1220                         break;
1221                 case Opt_wsize:
1222                         if (nfs_get_option_ul(args, &option))
1223                                 goto out_invalid_value;
1224                         mnt->wsize = option;
1225                         break;
1226                 case Opt_bsize:
1227                         if (nfs_get_option_ul(args, &option))
1228                                 goto out_invalid_value;
1229                         mnt->bsize = option;
1230                         break;
1231                 case Opt_timeo:
1232                         if (nfs_get_option_ul(args, &option) || option == 0)
1233                                 goto out_invalid_value;
1234                         mnt->timeo = option;
1235                         break;
1236                 case Opt_retrans:
1237                         if (nfs_get_option_ul(args, &option) || option == 0)
1238                                 goto out_invalid_value;
1239                         mnt->retrans = option;
1240                         break;
1241                 case Opt_acregmin:
1242                         if (nfs_get_option_ul(args, &option))
1243                                 goto out_invalid_value;
1244                         mnt->acregmin = option;
1245                         break;
1246                 case Opt_acregmax:
1247                         if (nfs_get_option_ul(args, &option))
1248                                 goto out_invalid_value;
1249                         mnt->acregmax = option;
1250                         break;
1251                 case Opt_acdirmin:
1252                         if (nfs_get_option_ul(args, &option))
1253                                 goto out_invalid_value;
1254                         mnt->acdirmin = option;
1255                         break;
1256                 case Opt_acdirmax:
1257                         if (nfs_get_option_ul(args, &option))
1258                                 goto out_invalid_value;
1259                         mnt->acdirmax = option;
1260                         break;
1261                 case Opt_actimeo:
1262                         if (nfs_get_option_ul(args, &option))
1263                                 goto out_invalid_value;
1264                         mnt->acregmin = mnt->acregmax =
1265                         mnt->acdirmin = mnt->acdirmax = option;
1266                         break;
1267                 case Opt_namelen:
1268                         if (nfs_get_option_ul(args, &option))
1269                                 goto out_invalid_value;
1270                         mnt->namlen = option;
1271                         break;
1272                 case Opt_mountport:
1273                         if (nfs_get_option_ul(args, &option) ||
1274                             option > USHRT_MAX)
1275                                 goto out_invalid_value;
1276                         mnt->mount_server.port = option;
1277                         break;
1278                 case Opt_mountvers:
1279                         if (nfs_get_option_ul(args, &option) ||
1280                             option < NFS_MNT_VERSION ||
1281                             option > NFS_MNT3_VERSION)
1282                                 goto out_invalid_value;
1283                         mnt->mount_server.version = option;
1284                         break;
1285                 case Opt_nfsvers:
1286                         if (nfs_get_option_ul(args, &option))
1287                                 goto out_invalid_value;
1288                         switch (option) {
1289                         case NFS2_VERSION:
1290                                 mnt->flags &= ~NFS_MOUNT_VER3;
1291                                 mnt->version = 2;
1292                                 break;
1293                         case NFS3_VERSION:
1294                                 mnt->flags |= NFS_MOUNT_VER3;
1295                                 mnt->version = 3;
1296                                 break;
1297                         case NFS4_VERSION:
1298                                 mnt->flags &= ~NFS_MOUNT_VER3;
1299                                 mnt->version = 4;
1300                                 break;
1301                         default:
1302                                 goto out_invalid_value;
1303                         }
1304                         break;
1305                 case Opt_minorversion:
1306                         if (nfs_get_option_ul(args, &option))
1307                                 goto out_invalid_value;
1308                         if (option > NFS4_MAX_MINOR_VERSION)
1309                                 goto out_invalid_value;
1310                         mnt->minorversion = option;
1311                         break;
1312
1313                 /*
1314                  * options that take text values
1315                  */
1316                 case Opt_sec:
1317                         string = match_strdup(args);
1318                         if (string == NULL)
1319                                 goto out_nomem;
1320                         rc = nfs_parse_security_flavors(string, mnt);
1321                         kfree(string);
1322                         if (!rc) {
1323                                 dfprintk(MOUNT, "NFS:   unrecognized "
1324                                                 "security flavor\n");
1325                                 return 0;
1326                         }
1327                         break;
1328                 case Opt_proto:
1329                         string = match_strdup(args);
1330                         if (string == NULL)
1331                                 goto out_nomem;
1332                         token = match_token(string,
1333                                             nfs_xprt_protocol_tokens, args);
1334
1335                         protofamily = AF_INET;
1336                         switch (token) {
1337                         case Opt_xprt_udp6:
1338                                 protofamily = AF_INET6;
1339                         case Opt_xprt_udp:
1340                                 mnt->flags &= ~NFS_MOUNT_TCP;
1341                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1342                                 break;
1343                         case Opt_xprt_tcp6:
1344                                 protofamily = AF_INET6;
1345                         case Opt_xprt_tcp:
1346                                 mnt->flags |= NFS_MOUNT_TCP;
1347                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1348                                 break;
1349                         case Opt_xprt_rdma:
1350                                 /* vector side protocols to TCP */
1351                                 mnt->flags |= NFS_MOUNT_TCP;
1352                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1353                                 xprt_load_transport(string);
1354                                 break;
1355                         default:
1356                                 dfprintk(MOUNT, "NFS:   unrecognized "
1357                                                 "transport protocol\n");
1358                                 kfree(string);
1359                                 return 0;
1360                         }
1361                         kfree(string);
1362                         break;
1363                 case Opt_mountproto:
1364                         string = match_strdup(args);
1365                         if (string == NULL)
1366                                 goto out_nomem;
1367                         token = match_token(string,
1368                                             nfs_xprt_protocol_tokens, args);
1369                         kfree(string);
1370
1371                         mountfamily = AF_INET;
1372                         switch (token) {
1373                         case Opt_xprt_udp6:
1374                                 mountfamily = AF_INET6;
1375                         case Opt_xprt_udp:
1376                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1377                                 break;
1378                         case Opt_xprt_tcp6:
1379                                 mountfamily = AF_INET6;
1380                         case Opt_xprt_tcp:
1381                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1382                                 break;
1383                         case Opt_xprt_rdma: /* not used for side protocols */
1384                         default:
1385                                 dfprintk(MOUNT, "NFS:   unrecognized "
1386                                                 "transport protocol\n");
1387                                 return 0;
1388                         }
1389                         break;
1390                 case Opt_addr:
1391                         string = match_strdup(args);
1392                         if (string == NULL)
1393                                 goto out_nomem;
1394                         mnt->nfs_server.addrlen =
1395                                 rpc_pton(string, strlen(string),
1396                                         (struct sockaddr *)
1397                                         &mnt->nfs_server.address,
1398                                         sizeof(mnt->nfs_server.address));
1399                         kfree(string);
1400                         if (mnt->nfs_server.addrlen == 0)
1401                                 goto out_invalid_address;
1402                         break;
1403                 case Opt_clientaddr:
1404                         if (nfs_get_option_str(args, &mnt->client_address))
1405                                 goto out_nomem;
1406                         break;
1407                 case Opt_mounthost:
1408                         if (nfs_get_option_str(args,
1409                                                &mnt->mount_server.hostname))
1410                                 goto out_nomem;
1411                         break;
1412                 case Opt_mountaddr:
1413                         string = match_strdup(args);
1414                         if (string == NULL)
1415                                 goto out_nomem;
1416                         mnt->mount_server.addrlen =
1417                                 rpc_pton(string, strlen(string),
1418                                         (struct sockaddr *)
1419                                         &mnt->mount_server.address,
1420                                         sizeof(mnt->mount_server.address));
1421                         kfree(string);
1422                         if (mnt->mount_server.addrlen == 0)
1423                                 goto out_invalid_address;
1424                         break;
1425                 case Opt_lookupcache:
1426                         string = match_strdup(args);
1427                         if (string == NULL)
1428                                 goto out_nomem;
1429                         token = match_token(string,
1430                                         nfs_lookupcache_tokens, args);
1431                         kfree(string);
1432                         switch (token) {
1433                                 case Opt_lookupcache_all:
1434                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1435                                         break;
1436                                 case Opt_lookupcache_positive:
1437                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1438                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1439                                         break;
1440                                 case Opt_lookupcache_none:
1441                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1442                                         break;
1443                                 default:
1444                                         dfprintk(MOUNT, "NFS:   invalid "
1445                                                         "lookupcache argument\n");
1446                                         return 0;
1447                         };
1448                         break;
1449                 case Opt_fscache_uniq:
1450                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1451                                 goto out_nomem;
1452                         mnt->options |= NFS_OPTION_FSCACHE;
1453                         break;
1454                 case Opt_local_lock:
1455                         string = match_strdup(args);
1456                         if (string == NULL)
1457                                 goto out_nomem;
1458                         token = match_token(string, nfs_local_lock_tokens,
1459                                         args);
1460                         kfree(string);
1461                         switch (token) {
1462                         case Opt_local_lock_all:
1463                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1464                                                NFS_MOUNT_LOCAL_FCNTL);
1465                                 break;
1466                         case Opt_local_lock_flock:
1467                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1468                                 break;
1469                         case Opt_local_lock_posix:
1470                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1471                                 break;
1472                         case Opt_local_lock_none:
1473                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1474                                                 NFS_MOUNT_LOCAL_FCNTL);
1475                                 break;
1476                         default:
1477                                 dfprintk(MOUNT, "NFS:   invalid "
1478                                                 "local_lock argument\n");
1479                                 return 0;
1480                         };
1481                         break;
1482
1483                 /*
1484                  * Special options
1485                  */
1486                 case Opt_sloppy:
1487                         sloppy = 1;
1488                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1489                         break;
1490                 case Opt_userspace:
1491                 case Opt_deprecated:
1492                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1493                                         "'%s'\n", p);
1494                         break;
1495
1496                 default:
1497                         invalid_option = 1;
1498                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1499                                         "'%s'\n", p);
1500                 }
1501         }
1502
1503         if (!sloppy && invalid_option)
1504                 return 0;
1505
1506         /*
1507          * verify that any proto=/mountproto= options match the address
1508          * familiies in the addr=/mountaddr= options.
1509          */
1510         if (protofamily != AF_UNSPEC &&
1511             protofamily != mnt->nfs_server.address.ss_family)
1512                 goto out_proto_mismatch;
1513
1514         if (mountfamily != AF_UNSPEC) {
1515                 if (mnt->mount_server.addrlen) {
1516                         if (mountfamily != mnt->mount_server.address.ss_family)
1517                                 goto out_mountproto_mismatch;
1518                 } else {
1519                         if (mountfamily != mnt->nfs_server.address.ss_family)
1520                                 goto out_mountproto_mismatch;
1521                 }
1522         }
1523
1524         return 1;
1525
1526 out_mountproto_mismatch:
1527         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1528                          "option\n");
1529         return 0;
1530 out_proto_mismatch:
1531         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1532         return 0;
1533 out_invalid_address:
1534         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1535         return 0;
1536 out_invalid_value:
1537         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1538         return 0;
1539 out_nomem:
1540         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1541         return 0;
1542 out_security_failure:
1543         free_secdata(secdata);
1544         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1545         return 0;
1546 }
1547
1548 /*
1549  * Match the requested auth flavors with the list returned by
1550  * the server.  Returns zero and sets the mount's authentication
1551  * flavor on success; returns -EACCES if server does not support
1552  * the requested flavor.
1553  */
1554 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1555                              struct nfs_mount_request *request)
1556 {
1557         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1558
1559         /*
1560          * Certain releases of Linux's mountd return an empty
1561          * flavor list.  To prevent behavioral regression with
1562          * these servers (ie. rejecting mounts that used to
1563          * succeed), revert to pre-2.6.32 behavior (no checking)
1564          * if the returned flavor list is empty.
1565          */
1566         if (server_authlist_len == 0)
1567                 return 0;
1568
1569         /*
1570          * We avoid sophisticated negotiating here, as there are
1571          * plenty of cases where we can get it wrong, providing
1572          * either too little or too much security.
1573          *
1574          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1575          * flavor listed first.  However, some servers list
1576          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1577          * preferred default, in args->auth_flavors[0] if user
1578          * didn't specify sec= mount option.
1579          */
1580         for (i = 0; i < args->auth_flavor_len; i++)
1581                 for (j = 0; j < server_authlist_len; j++)
1582                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1583                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1584                                         request->auth_flavs[j]);
1585                                 args->auth_flavors[0] = request->auth_flavs[j];
1586                                 return 0;
1587                         }
1588
1589         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1590         nfs_umount(request);
1591         return -EACCES;
1592 }
1593
1594 /*
1595  * Use the remote server's MOUNT service to request the NFS file handle
1596  * corresponding to the provided path.
1597  */
1598 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1599                          struct nfs_fh *root_fh)
1600 {
1601         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1602         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1603         struct nfs_mount_request request = {
1604                 .sap            = (struct sockaddr *)
1605                                                 &args->mount_server.address,
1606                 .dirpath        = args->nfs_server.export_path,
1607                 .protocol       = args->mount_server.protocol,
1608                 .fh             = root_fh,
1609                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1610                 .auth_flav_len  = &server_authlist_len,
1611                 .auth_flavs     = server_authlist,
1612         };
1613         int status;
1614
1615         if (args->mount_server.version == 0) {
1616                 switch (args->version) {
1617                         default:
1618                                 args->mount_server.version = NFS_MNT3_VERSION;
1619                                 break;
1620                         case 2:
1621                                 args->mount_server.version = NFS_MNT_VERSION;
1622                 }
1623         }
1624         request.version = args->mount_server.version;
1625
1626         if (args->mount_server.hostname)
1627                 request.hostname = args->mount_server.hostname;
1628         else
1629                 request.hostname = args->nfs_server.hostname;
1630
1631         /*
1632          * Construct the mount server's address.
1633          */
1634         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1635                 memcpy(request.sap, &args->nfs_server.address,
1636                        args->nfs_server.addrlen);
1637                 args->mount_server.addrlen = args->nfs_server.addrlen;
1638         }
1639         request.salen = args->mount_server.addrlen;
1640         nfs_set_port(request.sap, &args->mount_server.port, 0);
1641
1642         /*
1643          * Now ask the mount server to map our export path
1644          * to a file handle.
1645          */
1646         status = nfs_mount(&request);
1647         if (status != 0) {
1648                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1649                                 request.hostname, status);
1650                 return status;
1651         }
1652
1653         /*
1654          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1655          */
1656         if (args->mount_server.version != NFS_MNT3_VERSION)
1657                 return 0;
1658         return nfs_walk_authlist(args, &request);
1659 }
1660
1661 /*
1662  * Split "dev_name" into "hostname:export_path".
1663  *
1664  * The leftmost colon demarks the split between the server's hostname
1665  * and the export path.  If the hostname starts with a left square
1666  * bracket, then it may contain colons.
1667  *
1668  * Note: caller frees hostname and export path, even on error.
1669  */
1670 static int nfs_parse_devname(const char *dev_name,
1671                              char **hostname, size_t maxnamlen,
1672                              char **export_path, size_t maxpathlen)
1673 {
1674         size_t len;
1675         char *end;
1676
1677         /* Is the host name protected with square brakcets? */
1678         if (*dev_name == '[') {
1679                 end = strchr(++dev_name, ']');
1680                 if (end == NULL || end[1] != ':')
1681                         goto out_bad_devname;
1682
1683                 len = end - dev_name;
1684                 end++;
1685         } else {
1686                 char *comma;
1687
1688                 end = strchr(dev_name, ':');
1689                 if (end == NULL)
1690                         goto out_bad_devname;
1691                 len = end - dev_name;
1692
1693                 /* kill possible hostname list: not supported */
1694                 comma = strchr(dev_name, ',');
1695                 if (comma != NULL && comma < end)
1696                         *comma = 0;
1697         }
1698
1699         if (len > maxnamlen)
1700                 goto out_hostname;
1701
1702         /* N.B. caller will free nfs_server.hostname in all cases */
1703         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1704         if (*hostname == NULL)
1705                 goto out_nomem;
1706         len = strlen(++end);
1707         if (len > maxpathlen)
1708                 goto out_path;
1709         *export_path = kstrndup(end, len, GFP_KERNEL);
1710         if (!*export_path)
1711                 goto out_nomem;
1712
1713         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1714         return 0;
1715
1716 out_bad_devname:
1717         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1718         return -EINVAL;
1719
1720 out_nomem:
1721         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1722         return -ENOMEM;
1723
1724 out_hostname:
1725         dfprintk(MOUNT, "NFS: server hostname too long\n");
1726         return -ENAMETOOLONG;
1727
1728 out_path:
1729         dfprintk(MOUNT, "NFS: export pathname too long\n");
1730         return -ENAMETOOLONG;
1731 }
1732
1733 /*
1734  * Validate the NFS2/NFS3 mount data
1735  * - fills in the mount root filehandle
1736  *
1737  * For option strings, user space handles the following behaviors:
1738  *
1739  * + DNS: mapping server host name to IP address ("addr=" option)
1740  *
1741  * + failure mode: how to behave if a mount request can't be handled
1742  *   immediately ("fg/bg" option)
1743  *
1744  * + retry: how often to retry a mount request ("retry=" option)
1745  *
1746  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1747  *   mountproto=tcp after mountproto=udp, and so on
1748  */
1749 static int nfs_validate_mount_data(void *options,
1750                                    struct nfs_parsed_mount_data *args,
1751                                    struct nfs_fh *mntfh,
1752                                    const char *dev_name)
1753 {
1754         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1755         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1756
1757         if (data == NULL)
1758                 goto out_no_data;
1759
1760         switch (data->version) {
1761         case 1:
1762                 data->namlen = 0;
1763         case 2:
1764                 data->bsize = 0;
1765         case 3:
1766                 if (data->flags & NFS_MOUNT_VER3)
1767                         goto out_no_v3;
1768                 data->root.size = NFS2_FHSIZE;
1769                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1770         case 4:
1771                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1772                         goto out_no_sec;
1773         case 5:
1774                 memset(data->context, 0, sizeof(data->context));
1775         case 6:
1776                 if (data->flags & NFS_MOUNT_VER3) {
1777                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1778                                 goto out_invalid_fh;
1779                         mntfh->size = data->root.size;
1780                         args->version = 3;
1781                 } else {
1782                         mntfh->size = NFS2_FHSIZE;
1783                         args->version = 2;
1784                 }
1785
1786
1787                 memcpy(mntfh->data, data->root.data, mntfh->size);
1788                 if (mntfh->size < sizeof(mntfh->data))
1789                         memset(mntfh->data + mntfh->size, 0,
1790                                sizeof(mntfh->data) - mntfh->size);
1791
1792                 /*
1793                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1794                  * can deal with.
1795                  */
1796                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1797                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1798                 args->rsize             = data->rsize;
1799                 args->wsize             = data->wsize;
1800                 args->timeo             = data->timeo;
1801                 args->retrans           = data->retrans;
1802                 args->acregmin          = data->acregmin;
1803                 args->acregmax          = data->acregmax;
1804                 args->acdirmin          = data->acdirmin;
1805                 args->acdirmax          = data->acdirmax;
1806
1807                 memcpy(sap, &data->addr, sizeof(data->addr));
1808                 args->nfs_server.addrlen = sizeof(data->addr);
1809                 if (!nfs_verify_server_address(sap))
1810                         goto out_no_address;
1811
1812                 if (!(data->flags & NFS_MOUNT_TCP))
1813                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1814                 /* N.B. caller will free nfs_server.hostname in all cases */
1815                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1816                 args->namlen            = data->namlen;
1817                 args->bsize             = data->bsize;
1818
1819                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1820                         args->auth_flavors[0] = data->pseudoflavor;
1821                 if (!args->nfs_server.hostname)
1822                         goto out_nomem;
1823
1824                 if (!(data->flags & NFS_MOUNT_NONLM))
1825                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1826                                          NFS_MOUNT_LOCAL_FCNTL);
1827                 else
1828                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1829                                         NFS_MOUNT_LOCAL_FCNTL);
1830                 /*
1831                  * The legacy version 6 binary mount data from userspace has a
1832                  * field used only to transport selinux information into the
1833                  * the kernel.  To continue to support that functionality we
1834                  * have a touch of selinux knowledge here in the NFS code. The
1835                  * userspace code converted context=blah to just blah so we are
1836                  * converting back to the full string selinux understands.
1837                  */
1838                 if (data->context[0]){
1839 #ifdef CONFIG_SECURITY_SELINUX
1840                         int rc;
1841                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1842                         if (!opts_str)
1843                                 return -ENOMEM;
1844                         strcpy(opts_str, "context=");
1845                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1846                         strcat(opts_str, &data->context[0]);
1847                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1848                         kfree(opts_str);
1849                         if (rc)
1850                                 return rc;
1851 #else
1852                         return -EINVAL;
1853 #endif
1854                 }
1855
1856                 break;
1857         default: {
1858                 int status;
1859
1860                 if (nfs_parse_mount_options((char *)options, args) == 0)
1861                         return -EINVAL;
1862
1863                 if (!nfs_verify_server_address(sap))
1864                         goto out_no_address;
1865
1866                 if (args->version == 4)
1867 #ifdef CONFIG_NFS_V4
1868                         return nfs4_validate_text_mount_data(options,
1869                                                              args, dev_name);
1870 #else
1871                         goto out_v4_not_compiled;
1872 #endif
1873
1874                 nfs_set_port(sap, &args->nfs_server.port, 0);
1875
1876                 nfs_set_mount_transport_protocol(args);
1877
1878                 status = nfs_parse_devname(dev_name,
1879                                            &args->nfs_server.hostname,
1880                                            PAGE_SIZE,
1881                                            &args->nfs_server.export_path,
1882                                            NFS_MAXPATHLEN);
1883                 if (!status)
1884                         status = nfs_try_mount(args, mntfh);
1885
1886                 kfree(args->nfs_server.export_path);
1887                 args->nfs_server.export_path = NULL;
1888
1889                 if (status)
1890                         return status;
1891
1892                 break;
1893                 }
1894         }
1895
1896 #ifndef CONFIG_NFS_V3
1897         if (args->version == 3)
1898                 goto out_v3_not_compiled;
1899 #endif /* !CONFIG_NFS_V3 */
1900
1901         return 0;
1902
1903 out_no_data:
1904         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1905         return -EINVAL;
1906
1907 out_no_v3:
1908         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1909                  data->version);
1910         return -EINVAL;
1911
1912 out_no_sec:
1913         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1914         return -EINVAL;
1915
1916 #ifndef CONFIG_NFS_V3
1917 out_v3_not_compiled:
1918         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1919         return -EPROTONOSUPPORT;
1920 #endif /* !CONFIG_NFS_V3 */
1921
1922 #ifndef CONFIG_NFS_V4
1923 out_v4_not_compiled:
1924         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1925         return -EPROTONOSUPPORT;
1926 #endif /* !CONFIG_NFS_V4 */
1927
1928 out_nomem:
1929         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1930         return -ENOMEM;
1931
1932 out_no_address:
1933         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1934         return -EINVAL;
1935
1936 out_invalid_fh:
1937         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1938         return -EINVAL;
1939 }
1940
1941 static int
1942 nfs_compare_remount_data(struct nfs_server *nfss,
1943                          struct nfs_parsed_mount_data *data)
1944 {
1945         if (data->flags != nfss->flags ||
1946             data->rsize != nfss->rsize ||
1947             data->wsize != nfss->wsize ||
1948             data->retrans != nfss->client->cl_timeout->to_retries ||
1949             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1950             data->acregmin != nfss->acregmin / HZ ||
1951             data->acregmax != nfss->acregmax / HZ ||
1952             data->acdirmin != nfss->acdirmin / HZ ||
1953             data->acdirmax != nfss->acdirmax / HZ ||
1954             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1955             data->nfs_server.port != nfss->port ||
1956             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1957             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1958                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
1959                 return -EINVAL;
1960
1961         return 0;
1962 }
1963
1964 static int
1965 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1966 {
1967         int error;
1968         struct nfs_server *nfss = sb->s_fs_info;
1969         struct nfs_parsed_mount_data *data;
1970         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1971         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1972         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1973
1974         /*
1975          * Userspace mount programs that send binary options generally send
1976          * them populated with default values. We have no way to know which
1977          * ones were explicitly specified. Fall back to legacy behavior and
1978          * just return success.
1979          */
1980         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1981             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1982                                            options->version <= 6))))
1983                 return 0;
1984
1985         data = kzalloc(sizeof(*data), GFP_KERNEL);
1986         if (data == NULL)
1987                 return -ENOMEM;
1988
1989         /* fill out struct with values from existing mount */
1990         data->flags = nfss->flags;
1991         data->rsize = nfss->rsize;
1992         data->wsize = nfss->wsize;
1993         data->retrans = nfss->client->cl_timeout->to_retries;
1994         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1995         data->acregmin = nfss->acregmin / HZ;
1996         data->acregmax = nfss->acregmax / HZ;
1997         data->acdirmin = nfss->acdirmin / HZ;
1998         data->acdirmax = nfss->acdirmax / HZ;
1999         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2000         data->nfs_server.port = nfss->port;
2001         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2002         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2003                 data->nfs_server.addrlen);
2004
2005         /* overwrite those values with any that were specified */
2006         error = nfs_parse_mount_options((char *)options, data);
2007         if (error < 0)
2008                 goto out;
2009
2010         /*
2011          * noac is a special case. It implies -o sync, but that's not
2012          * necessarily reflected in the mtab options. do_remount_sb
2013          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2014          * remount options, so we have to explicitly reset it.
2015          */
2016         if (data->flags & NFS_MOUNT_NOAC)
2017                 *flags |= MS_SYNCHRONOUS;
2018
2019         /* compare new mount options with old ones */
2020         error = nfs_compare_remount_data(nfss, data);
2021 out:
2022         kfree(data);
2023         return error;
2024 }
2025
2026 /*
2027  * Initialise the common bits of the superblock
2028  */
2029 static inline void nfs_initialise_sb(struct super_block *sb)
2030 {
2031         struct nfs_server *server = NFS_SB(sb);
2032
2033         sb->s_magic = NFS_SUPER_MAGIC;
2034
2035         /* We probably want something more informative here */
2036         snprintf(sb->s_id, sizeof(sb->s_id),
2037                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2038
2039         if (sb->s_blocksize == 0)
2040                 sb->s_blocksize = nfs_block_bits(server->wsize,
2041                                                  &sb->s_blocksize_bits);
2042
2043         sb->s_bdi = &server->backing_dev_info;
2044
2045         nfs_super_set_maxbytes(sb, server->maxfilesize);
2046 }
2047
2048 /*
2049  * Finish setting up an NFS2/3 superblock
2050  */
2051 static void nfs_fill_super(struct super_block *sb,
2052                            struct nfs_parsed_mount_data *data)
2053 {
2054         struct nfs_server *server = NFS_SB(sb);
2055
2056         sb->s_blocksize_bits = 0;
2057         sb->s_blocksize = 0;
2058         if (data->bsize)
2059                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2060
2061         if (server->nfs_client->rpc_ops->version == 3) {
2062                 /* The VFS shouldn't apply the umask to mode bits. We will do
2063                  * so ourselves when necessary.
2064                  */
2065                 sb->s_flags |= MS_POSIXACL;
2066                 sb->s_time_gran = 1;
2067         }
2068
2069         sb->s_op = &nfs_sops;
2070         nfs_initialise_sb(sb);
2071 }
2072
2073 /*
2074  * Finish setting up a cloned NFS2/3 superblock
2075  */
2076 static void nfs_clone_super(struct super_block *sb,
2077                             const struct super_block *old_sb)
2078 {
2079         struct nfs_server *server = NFS_SB(sb);
2080
2081         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2082         sb->s_blocksize = old_sb->s_blocksize;
2083         sb->s_maxbytes = old_sb->s_maxbytes;
2084
2085         if (server->nfs_client->rpc_ops->version == 3) {
2086                 /* The VFS shouldn't apply the umask to mode bits. We will do
2087                  * so ourselves when necessary.
2088                  */
2089                 sb->s_flags |= MS_POSIXACL;
2090                 sb->s_time_gran = 1;
2091         }
2092
2093         sb->s_op = old_sb->s_op;
2094         nfs_initialise_sb(sb);
2095 }
2096
2097 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2098 {
2099         const struct nfs_server *a = s->s_fs_info;
2100         const struct rpc_clnt *clnt_a = a->client;
2101         const struct rpc_clnt *clnt_b = b->client;
2102
2103         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2104                 goto Ebusy;
2105         if (a->nfs_client != b->nfs_client)
2106                 goto Ebusy;
2107         if (a->flags != b->flags)
2108                 goto Ebusy;
2109         if (a->wsize != b->wsize)
2110                 goto Ebusy;
2111         if (a->rsize != b->rsize)
2112                 goto Ebusy;
2113         if (a->acregmin != b->acregmin)
2114                 goto Ebusy;
2115         if (a->acregmax != b->acregmax)
2116                 goto Ebusy;
2117         if (a->acdirmin != b->acdirmin)
2118                 goto Ebusy;
2119         if (a->acdirmax != b->acdirmax)
2120                 goto Ebusy;
2121         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2122                 goto Ebusy;
2123         return 1;
2124 Ebusy:
2125         return 0;
2126 }
2127
2128 struct nfs_sb_mountdata {
2129         struct nfs_server *server;
2130         int mntflags;
2131 };
2132
2133 static int nfs_set_super(struct super_block *s, void *data)
2134 {
2135         struct nfs_sb_mountdata *sb_mntdata = data;
2136         struct nfs_server *server = sb_mntdata->server;
2137         int ret;
2138
2139         s->s_flags = sb_mntdata->mntflags;
2140         s->s_fs_info = server;
2141         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2142         ret = set_anon_super(s, server);
2143         if (ret == 0)
2144                 server->s_dev = s->s_dev;
2145         return ret;
2146 }
2147
2148 static int nfs_compare_super_address(struct nfs_server *server1,
2149                                      struct nfs_server *server2)
2150 {
2151         struct sockaddr *sap1, *sap2;
2152
2153         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2154         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2155
2156         if (sap1->sa_family != sap2->sa_family)
2157                 return 0;
2158
2159         switch (sap1->sa_family) {
2160         case AF_INET: {
2161                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2162                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2163                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2164                         return 0;
2165                 if (sin1->sin_port != sin2->sin_port)
2166                         return 0;
2167                 break;
2168         }
2169         case AF_INET6: {
2170                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2171                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2172                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2173                         return 0;
2174                 if (sin1->sin6_port != sin2->sin6_port)
2175                         return 0;
2176                 break;
2177         }
2178         default:
2179                 return 0;
2180         }
2181
2182         return 1;
2183 }
2184
2185 static int nfs_compare_super(struct super_block *sb, void *data)
2186 {
2187         struct nfs_sb_mountdata *sb_mntdata = data;
2188         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2189         int mntflags = sb_mntdata->mntflags;
2190
2191         if (!nfs_compare_super_address(old, server))
2192                 return 0;
2193         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2194         if (old->flags & NFS_MOUNT_UNSHARED)
2195                 return 0;
2196         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2197                 return 0;
2198         return nfs_compare_mount_options(sb, server, mntflags);
2199 }
2200
2201 static int nfs_bdi_register(struct nfs_server *server)
2202 {
2203         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2204 }
2205
2206 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2207         int flags, const char *dev_name, void *raw_data)
2208 {
2209         struct nfs_server *server = NULL;
2210         struct super_block *s;
2211         struct nfs_parsed_mount_data *data;
2212         struct nfs_fh *mntfh;
2213         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2214         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2215         struct nfs_sb_mountdata sb_mntdata = {
2216                 .mntflags = flags,
2217         };
2218         int error;
2219
2220         data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2221         mntfh = nfs_alloc_fhandle();
2222         if (data == NULL || mntfh == NULL)
2223                 goto out_free_fh;
2224
2225         security_init_mnt_opts(&data->lsm_opts);
2226
2227         /* Validate the mount data */
2228         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2229         if (error < 0) {
2230                 mntroot = ERR_PTR(error);
2231                 goto out;
2232         }
2233
2234 #ifdef CONFIG_NFS_V4
2235         if (data->version == 4) {
2236                 mntroot = nfs4_try_mount(flags, dev_name, data);
2237                 kfree(data->client_address);
2238                 kfree(data->nfs_server.export_path);
2239                 goto out;
2240         }
2241 #endif  /* CONFIG_NFS_V4 */
2242
2243         /* Get a volume representation */
2244         server = nfs_create_server(data, mntfh);
2245         if (IS_ERR(server)) {
2246                 mntroot = ERR_CAST(server);
2247                 goto out;
2248         }
2249         sb_mntdata.server = server;
2250
2251         if (server->flags & NFS_MOUNT_UNSHARED)
2252                 compare_super = NULL;
2253
2254         /* -o noac implies -o sync */
2255         if (server->flags & NFS_MOUNT_NOAC)
2256                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2257
2258         /* Get a superblock - note that we may end up sharing one that already exists */
2259         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2260         if (IS_ERR(s)) {
2261                 mntroot = ERR_CAST(s);
2262                 goto out_err_nosb;
2263         }
2264
2265         if (s->s_fs_info != server) {
2266                 nfs_free_server(server);
2267                 server = NULL;
2268         } else {
2269                 error = nfs_bdi_register(server);
2270                 if (error) {
2271                         mntroot = ERR_PTR(error);
2272                         goto error_splat_bdi;
2273                 }
2274         }
2275
2276         if (!s->s_root) {
2277                 /* initial superblock/root creation */
2278                 nfs_fill_super(s, data);
2279                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2280         }
2281
2282         mntroot = nfs_get_root(s, mntfh, dev_name);
2283         if (IS_ERR(mntroot))
2284                 goto error_splat_super;
2285
2286         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2287         if (error)
2288                 goto error_splat_root;
2289
2290         s->s_flags |= MS_ACTIVE;
2291
2292 out:
2293         kfree(data->nfs_server.hostname);
2294         kfree(data->mount_server.hostname);
2295         kfree(data->fscache_uniq);
2296         security_free_mnt_opts(&data->lsm_opts);
2297 out_free_fh:
2298         nfs_free_fhandle(mntfh);
2299         kfree(data);
2300         return mntroot;
2301
2302 out_err_nosb:
2303         nfs_free_server(server);
2304         goto out;
2305
2306 error_splat_root:
2307         dput(mntroot);
2308         mntroot = ERR_PTR(error);
2309 error_splat_super:
2310         if (server && !s->s_root)
2311                 bdi_unregister(&server->backing_dev_info);
2312 error_splat_bdi:
2313         deactivate_locked_super(s);
2314         goto out;
2315 }
2316
2317 /*
2318  * Ensure that we unregister the bdi before kill_anon_super
2319  * releases the device name
2320  */
2321 static void nfs_put_super(struct super_block *s)
2322 {
2323         struct nfs_server *server = NFS_SB(s);
2324
2325         bdi_unregister(&server->backing_dev_info);
2326 }
2327
2328 /*
2329  * Destroy an NFS2/3 superblock
2330  */
2331 static void nfs_kill_super(struct super_block *s)
2332 {
2333         struct nfs_server *server = NFS_SB(s);
2334
2335         kill_anon_super(s);
2336         nfs_fscache_release_super_cookie(s);
2337         nfs_free_server(server);
2338 }
2339
2340 /*
2341  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2342  */
2343 static struct dentry *
2344 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2345                 const char *dev_name, void *raw_data)
2346 {
2347         struct nfs_clone_mount *data = raw_data;
2348         struct super_block *s;
2349         struct nfs_server *server;
2350         struct dentry *mntroot;
2351         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2352         struct nfs_sb_mountdata sb_mntdata = {
2353                 .mntflags = flags,
2354         };
2355         int error;
2356
2357         dprintk("--> nfs_xdev_mount()\n");
2358
2359         /* create a new volume representation */
2360         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2361         if (IS_ERR(server)) {
2362                 error = PTR_ERR(server);
2363                 goto out_err_noserver;
2364         }
2365         sb_mntdata.server = server;
2366
2367         if (server->flags & NFS_MOUNT_UNSHARED)
2368                 compare_super = NULL;
2369
2370         /* -o noac implies -o sync */
2371         if (server->flags & NFS_MOUNT_NOAC)
2372                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2373
2374         /* Get a superblock - note that we may end up sharing one that already exists */
2375         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2376         if (IS_ERR(s)) {
2377                 error = PTR_ERR(s);
2378                 goto out_err_nosb;
2379         }
2380
2381         if (s->s_fs_info != server) {
2382                 nfs_free_server(server);
2383                 server = NULL;
2384         } else {
2385                 error = nfs_bdi_register(server);
2386                 if (error)
2387                         goto error_splat_bdi;
2388         }
2389
2390         if (!s->s_root) {
2391                 /* initial superblock/root creation */
2392                 nfs_clone_super(s, data->sb);
2393                 nfs_fscache_get_super_cookie(s, NULL, data);
2394         }
2395
2396         mntroot = nfs_get_root(s, data->fh, dev_name);
2397         if (IS_ERR(mntroot)) {
2398                 error = PTR_ERR(mntroot);
2399                 goto error_splat_super;
2400         }
2401         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2402                 dput(mntroot);
2403                 error = -ESTALE;
2404                 goto error_splat_super;
2405         }
2406
2407         s->s_flags |= MS_ACTIVE;
2408
2409         /* clone any lsm security options from the parent to the new sb */
2410         security_sb_clone_mnt_opts(data->sb, s);
2411
2412         dprintk("<-- nfs_xdev_mount() = 0\n");
2413         return mntroot;
2414
2415 out_err_nosb:
2416         nfs_free_server(server);
2417 out_err_noserver:
2418         dprintk("<-- nfs_xdev_mount() = %d [error]\n", error);
2419         return ERR_PTR(error);
2420
2421 error_splat_super:
2422         if (server && !s->s_root)
2423                 bdi_unregister(&server->backing_dev_info);
2424 error_splat_bdi:
2425         deactivate_locked_super(s);
2426         dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error);
2427         return ERR_PTR(error);
2428 }
2429
2430 #ifdef CONFIG_NFS_V4
2431
2432 /*
2433  * Finish setting up a cloned NFS4 superblock
2434  */
2435 static void nfs4_clone_super(struct super_block *sb,
2436                             const struct super_block *old_sb)
2437 {
2438         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2439         sb->s_blocksize = old_sb->s_blocksize;
2440         sb->s_maxbytes = old_sb->s_maxbytes;
2441         sb->s_time_gran = 1;
2442         sb->s_op = old_sb->s_op;
2443         /*
2444          * The VFS shouldn't apply the umask to mode bits. We will do
2445          * so ourselves when necessary.
2446          */
2447         sb->s_flags  |= MS_POSIXACL;
2448         sb->s_xattr  = old_sb->s_xattr;
2449         nfs_initialise_sb(sb);
2450 }
2451
2452 /*
2453  * Set up an NFS4 superblock
2454  */
2455 static void nfs4_fill_super(struct super_block *sb)
2456 {
2457         sb->s_time_gran = 1;
2458         sb->s_op = &nfs4_sops;
2459         /*
2460          * The VFS shouldn't apply the umask to mode bits. We will do
2461          * so ourselves when necessary.
2462          */
2463         sb->s_flags  |= MS_POSIXACL;
2464         sb->s_xattr = nfs4_xattr_handlers;
2465         nfs_initialise_sb(sb);
2466 }
2467
2468 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2469 {
2470         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2471                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2472 }
2473
2474 static int nfs4_validate_text_mount_data(void *options,
2475                                          struct nfs_parsed_mount_data *args,
2476                                          const char *dev_name)
2477 {
2478         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2479
2480         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2481
2482         nfs_validate_transport_protocol(args);
2483
2484         nfs4_validate_mount_flags(args);
2485
2486         if (args->version != 4) {
2487                 dfprintk(MOUNT,
2488                          "NFS4: Illegal mount version\n");
2489                 return -EINVAL;
2490         }
2491
2492         if (args->auth_flavor_len > 1) {
2493                 dfprintk(MOUNT,
2494                          "NFS4: Too many RPC auth flavours specified\n");
2495                 return -EINVAL;
2496         }
2497
2498         if (args->client_address == NULL) {
2499                 dfprintk(MOUNT,
2500                          "NFS4: mount program didn't pass callback address\n");
2501                 return -EINVAL;
2502         }
2503
2504         return nfs_parse_devname(dev_name,
2505                                    &args->nfs_server.hostname,
2506                                    NFS4_MAXNAMLEN,
2507                                    &args->nfs_server.export_path,
2508                                    NFS4_MAXPATHLEN);
2509 }
2510
2511 /*
2512  * Validate NFSv4 mount options
2513  */
2514 static int nfs4_validate_mount_data(void *options,
2515                                     struct nfs_parsed_mount_data *args,
2516                                     const char *dev_name)
2517 {
2518         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2519         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2520         char *c;
2521
2522         if (data == NULL)
2523                 goto out_no_data;
2524
2525         switch (data->version) {
2526         case 1:
2527                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2528                         goto out_no_address;
2529                 if (data->host_addrlen == 0)
2530                         goto out_no_address;
2531                 args->nfs_server.addrlen = data->host_addrlen;
2532                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2533                         return -EFAULT;
2534                 if (!nfs_verify_server_address(sap))
2535                         goto out_no_address;
2536
2537                 if (data->auth_flavourlen) {
2538                         if (data->auth_flavourlen > 1)
2539                                 goto out_inval_auth;
2540                         if (copy_from_user(&args->auth_flavors[0],
2541                                            data->auth_flavours,
2542                                            sizeof(args->auth_flavors[0])))
2543                                 return -EFAULT;
2544                 }
2545
2546                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2547                 if (IS_ERR(c))
2548                         return PTR_ERR(c);
2549                 args->nfs_server.hostname = c;
2550
2551                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2552                 if (IS_ERR(c))
2553                         return PTR_ERR(c);
2554                 args->nfs_server.export_path = c;
2555                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2556
2557                 c = strndup_user(data->client_addr.data, 16);
2558                 if (IS_ERR(c))
2559                         return PTR_ERR(c);
2560                 args->client_address = c;
2561
2562                 /*
2563                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2564                  * can deal with.
2565                  */
2566
2567                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2568                 args->rsize     = data->rsize;
2569                 args->wsize     = data->wsize;
2570                 args->timeo     = data->timeo;
2571                 args->retrans   = data->retrans;
2572                 args->acregmin  = data->acregmin;
2573                 args->acregmax  = data->acregmax;
2574                 args->acdirmin  = data->acdirmin;
2575                 args->acdirmax  = data->acdirmax;
2576                 args->nfs_server.protocol = data->proto;
2577                 nfs_validate_transport_protocol(args);
2578
2579                 break;
2580         default:
2581                 if (nfs_parse_mount_options((char *)options, args) == 0)
2582                         return -EINVAL;
2583
2584                 if (!nfs_verify_server_address(sap))
2585                         return -EINVAL;
2586
2587                 return nfs4_validate_text_mount_data(options, args, dev_name);
2588         }
2589
2590         return 0;
2591
2592 out_no_data:
2593         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2594         return -EINVAL;
2595
2596 out_inval_auth:
2597         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2598                  data->auth_flavourlen);
2599         return -EINVAL;
2600
2601 out_no_address:
2602         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2603         return -EINVAL;
2604 }
2605
2606 /*
2607  * Get the superblock for the NFS4 root partition
2608  */
2609 static struct dentry *
2610 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2611                   const char *dev_name, void *raw_data)
2612 {
2613         struct nfs_parsed_mount_data *data = raw_data;
2614         struct super_block *s;
2615         struct nfs_server *server;
2616         struct nfs_fh *mntfh;
2617         struct dentry *mntroot;
2618         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2619         struct nfs_sb_mountdata sb_mntdata = {
2620                 .mntflags = flags,
2621         };
2622         int error = -ENOMEM;
2623
2624         mntfh = nfs_alloc_fhandle();
2625         if (data == NULL || mntfh == NULL)
2626                 goto out_free_fh;
2627
2628         security_init_mnt_opts(&data->lsm_opts);
2629
2630         /* Get a volume representation */
2631         server = nfs4_create_server(data, mntfh);
2632         if (IS_ERR(server)) {
2633                 error = PTR_ERR(server);
2634                 goto out;
2635         }
2636         sb_mntdata.server = server;
2637
2638         if (server->flags & NFS4_MOUNT_UNSHARED)
2639                 compare_super = NULL;
2640
2641         /* -o noac implies -o sync */
2642         if (server->flags & NFS_MOUNT_NOAC)
2643                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2644
2645         /* Get a superblock - note that we may end up sharing one that already exists */
2646         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2647         if (IS_ERR(s)) {
2648                 error = PTR_ERR(s);
2649                 goto out_free;
2650         }
2651
2652         if (s->s_fs_info != server) {
2653                 nfs_free_server(server);
2654                 server = NULL;
2655         } else {
2656                 error = nfs_bdi_register(server);
2657                 if (error)
2658                         goto error_splat_bdi;
2659         }
2660
2661         if (!s->s_root) {
2662                 /* initial superblock/root creation */
2663                 nfs4_fill_super(s);
2664                 nfs_fscache_get_super_cookie(
2665                         s, data ? data->fscache_uniq : NULL, NULL);
2666         }
2667
2668         mntroot = nfs4_get_root(s, mntfh, dev_name);
2669         if (IS_ERR(mntroot)) {
2670                 error = PTR_ERR(mntroot);
2671                 goto error_splat_super;
2672         }
2673
2674         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2675         if (error)
2676                 goto error_splat_root;
2677
2678         s->s_flags |= MS_ACTIVE;
2679
2680         security_free_mnt_opts(&data->lsm_opts);
2681         nfs_free_fhandle(mntfh);
2682         return mntroot;
2683
2684 out:
2685         security_free_mnt_opts(&data->lsm_opts);
2686 out_free_fh:
2687         nfs_free_fhandle(mntfh);
2688         return ERR_PTR(error);
2689
2690 out_free:
2691         nfs_free_server(server);
2692         goto out;
2693
2694 error_splat_root:
2695         dput(mntroot);
2696 error_splat_super:
2697         if (server && !s->s_root)
2698                 bdi_unregister(&server->backing_dev_info);
2699 error_splat_bdi:
2700         deactivate_locked_super(s);
2701         goto out;
2702 }
2703
2704 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2705                 int flags, void *data, const char *hostname)
2706 {
2707         struct vfsmount *root_mnt;
2708         char *root_devname;
2709         size_t len;
2710
2711         len = strlen(hostname) + 3;
2712         root_devname = kmalloc(len, GFP_KERNEL);
2713         if (root_devname == NULL)
2714                 return ERR_PTR(-ENOMEM);
2715         snprintf(root_devname, len, "%s:/", hostname);
2716         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2717         kfree(root_devname);
2718         return root_mnt;
2719 }
2720
2721 struct nfs_referral_count {
2722         struct list_head list;
2723         const struct task_struct *task;
2724         unsigned int referral_count;
2725 };
2726
2727 static LIST_HEAD(nfs_referral_count_list);
2728 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2729
2730 static struct nfs_referral_count *nfs_find_referral_count(void)
2731 {
2732         struct nfs_referral_count *p;
2733
2734         list_for_each_entry(p, &nfs_referral_count_list, list) {
2735                 if (p->task == current)
2736                         return p;
2737         }
2738         return NULL;
2739 }
2740
2741 #define NFS_MAX_NESTED_REFERRALS 2
2742
2743 static int nfs_referral_loop_protect(void)
2744 {
2745         struct nfs_referral_count *p, *new;
2746         int ret = -ENOMEM;
2747
2748         new = kmalloc(sizeof(*new), GFP_KERNEL);
2749         if (!new)
2750                 goto out;
2751         new->task = current;
2752         new->referral_count = 1;
2753
2754         ret = 0;
2755         spin_lock(&nfs_referral_count_list_lock);
2756         p = nfs_find_referral_count();
2757         if (p != NULL) {
2758                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2759                         ret = -ELOOP;
2760                 else
2761                         p->referral_count++;
2762         } else {
2763                 list_add(&new->list, &nfs_referral_count_list);
2764                 new = NULL;
2765         }
2766         spin_unlock(&nfs_referral_count_list_lock);
2767         kfree(new);
2768 out:
2769         return ret;
2770 }
2771
2772 static void nfs_referral_loop_unprotect(void)
2773 {
2774         struct nfs_referral_count *p;
2775
2776         spin_lock(&nfs_referral_count_list_lock);
2777         p = nfs_find_referral_count();
2778         p->referral_count--;
2779         if (p->referral_count == 0)
2780                 list_del(&p->list);
2781         else
2782                 p = NULL;
2783         spin_unlock(&nfs_referral_count_list_lock);
2784         kfree(p);
2785 }
2786
2787 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2788                 const char *export_path)
2789 {
2790         struct mnt_namespace *ns_private;
2791         struct super_block *s;
2792         struct dentry *dentry;
2793         struct path path;
2794         int ret;
2795
2796         ns_private = create_mnt_ns(root_mnt);
2797         ret = PTR_ERR(ns_private);
2798         if (IS_ERR(ns_private))
2799                 goto out_mntput;
2800
2801         ret = nfs_referral_loop_protect();
2802         if (ret != 0)
2803                 goto out_put_mnt_ns;
2804
2805         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2806                         export_path, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
2807
2808         nfs_referral_loop_unprotect();
2809         put_mnt_ns(ns_private);
2810
2811         if (ret != 0)
2812                 goto out_err;
2813
2814         s = path.mnt->mnt_sb;
2815         atomic_inc(&s->s_active);
2816         dentry = dget(path.dentry);
2817
2818         path_put(&path);
2819         down_write(&s->s_umount);
2820         return dentry;
2821 out_put_mnt_ns:
2822         put_mnt_ns(ns_private);
2823 out_mntput:
2824         mntput(root_mnt);
2825 out_err:
2826         return ERR_PTR(ret);
2827 }
2828
2829 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2830                          struct nfs_parsed_mount_data *data)
2831 {
2832         char *export_path;
2833         struct vfsmount *root_mnt;
2834         struct dentry *res;
2835
2836         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2837
2838         export_path = data->nfs_server.export_path;
2839         data->nfs_server.export_path = "/";
2840         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2841                         data->nfs_server.hostname);
2842         data->nfs_server.export_path = export_path;
2843
2844         res = ERR_CAST(root_mnt);
2845         if (!IS_ERR(root_mnt))
2846                 res = nfs_follow_remote_path(root_mnt, export_path);
2847
2848         dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2849                         IS_ERR(res) ? PTR_ERR(res) : 0,
2850                         IS_ERR(res) ? " [error]" : "");
2851         return res;
2852 }
2853
2854 /*
2855  * Get the superblock for an NFS4 mountpoint
2856  */
2857 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2858         int flags, const char *dev_name, void *raw_data)
2859 {
2860         struct nfs_parsed_mount_data *data;
2861         int error = -ENOMEM;
2862         struct dentry *res = ERR_PTR(-ENOMEM);
2863
2864         data = nfs_alloc_parsed_mount_data(4);
2865         if (data == NULL)
2866                 goto out_free_data;
2867
2868         /* Validate the mount data */
2869         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2870         if (error < 0) {
2871                 res = ERR_PTR(error);
2872                 goto out;
2873         }
2874
2875         res = nfs4_try_mount(flags, dev_name, data);
2876         if (IS_ERR(res))
2877                 error = PTR_ERR(res);
2878
2879 out:
2880         kfree(data->client_address);
2881         kfree(data->nfs_server.export_path);
2882         kfree(data->nfs_server.hostname);
2883         kfree(data->fscache_uniq);
2884 out_free_data:
2885         kfree(data);
2886         dprintk("<-- nfs4_mount() = %d%s\n", error,
2887                         error != 0 ? " [error]" : "");
2888         return res;
2889 }
2890
2891 static void nfs4_kill_super(struct super_block *sb)
2892 {
2893         struct nfs_server *server = NFS_SB(sb);
2894
2895         dprintk("--> %s\n", __func__);
2896         nfs_super_return_all_delegations(sb);
2897         kill_anon_super(sb);
2898         nfs_fscache_release_super_cookie(sb);
2899         nfs_free_server(server);
2900         dprintk("<-- %s\n", __func__);
2901 }
2902
2903 /*
2904  * Clone an NFS4 server record on xdev traversal (FSID-change)
2905  */
2906 static struct dentry *
2907 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2908                  const char *dev_name, void *raw_data)
2909 {
2910         struct nfs_clone_mount *data = raw_data;
2911         struct super_block *s;
2912         struct nfs_server *server;
2913         struct dentry *mntroot;
2914         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2915         struct nfs_sb_mountdata sb_mntdata = {
2916                 .mntflags = flags,
2917         };
2918         int error;
2919
2920         dprintk("--> nfs4_xdev_mount()\n");
2921
2922         /* create a new volume representation */
2923         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2924         if (IS_ERR(server)) {
2925                 error = PTR_ERR(server);
2926                 goto out_err_noserver;
2927         }
2928         sb_mntdata.server = server;
2929
2930         if (server->flags & NFS4_MOUNT_UNSHARED)
2931                 compare_super = NULL;
2932
2933         /* -o noac implies -o sync */
2934         if (server->flags & NFS_MOUNT_NOAC)
2935                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2936
2937         /* Get a superblock - note that we may end up sharing one that already exists */
2938         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2939         if (IS_ERR(s)) {
2940                 error = PTR_ERR(s);
2941                 goto out_err_nosb;
2942         }
2943
2944         if (s->s_fs_info != server) {
2945                 nfs_free_server(server);
2946                 server = NULL;
2947         } else {
2948                 error = nfs_bdi_register(server);
2949                 if (error)
2950                         goto error_splat_bdi;
2951         }
2952
2953         if (!s->s_root) {
2954                 /* initial superblock/root creation */
2955                 nfs4_clone_super(s, data->sb);
2956                 nfs_fscache_get_super_cookie(s, NULL, data);
2957         }
2958
2959         mntroot = nfs4_get_root(s, data->fh, dev_name);
2960         if (IS_ERR(mntroot)) {
2961                 error = PTR_ERR(mntroot);
2962                 goto error_splat_super;
2963         }
2964         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2965                 dput(mntroot);
2966                 error = -ESTALE;
2967                 goto error_splat_super;
2968         }
2969
2970         s->s_flags |= MS_ACTIVE;
2971
2972         security_sb_clone_mnt_opts(data->sb, s);
2973
2974         dprintk("<-- nfs4_xdev_mount() = 0\n");
2975         return mntroot;
2976
2977 out_err_nosb:
2978         nfs_free_server(server);
2979 out_err_noserver:
2980         dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error);
2981         return ERR_PTR(error);
2982
2983 error_splat_super:
2984         if (server && !s->s_root)
2985                 bdi_unregister(&server->backing_dev_info);
2986 error_splat_bdi:
2987         deactivate_locked_super(s);
2988         dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error);
2989         return ERR_PTR(error);
2990 }
2991
2992 static struct dentry *
2993 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2994                            const char *dev_name, void *raw_data)
2995 {
2996         struct nfs_clone_mount *data = raw_data;
2997         struct super_block *s;
2998         struct nfs_server *server;
2999         struct dentry *mntroot;
3000         struct nfs_fh *mntfh;
3001         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
3002         struct nfs_sb_mountdata sb_mntdata = {
3003                 .mntflags = flags,
3004         };
3005         int error = -ENOMEM;
3006
3007         dprintk("--> nfs4_referral_get_sb()\n");
3008
3009         mntfh = nfs_alloc_fhandle();
3010         if (mntfh == NULL)
3011                 goto out_err_nofh;
3012
3013         /* create a new volume representation */
3014         server = nfs4_create_referral_server(data, mntfh);
3015         if (IS_ERR(server)) {
3016                 error = PTR_ERR(server);
3017                 goto out_err_noserver;
3018         }
3019         sb_mntdata.server = server;
3020
3021         if (server->flags & NFS4_MOUNT_UNSHARED)
3022                 compare_super = NULL;
3023
3024         /* -o noac implies -o sync */
3025         if (server->flags & NFS_MOUNT_NOAC)
3026                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
3027
3028         /* Get a superblock - note that we may end up sharing one that already exists */
3029         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3030         if (IS_ERR(s)) {
3031                 error = PTR_ERR(s);
3032                 goto out_err_nosb;
3033         }
3034
3035         if (s->s_fs_info != server) {
3036                 nfs_free_server(server);
3037                 server = NULL;
3038         } else {
3039                 error = nfs_bdi_register(server);
3040                 if (error)
3041                         goto error_splat_bdi;
3042         }
3043
3044         if (!s->s_root) {
3045                 /* initial superblock/root creation */
3046                 nfs4_fill_super(s);
3047                 nfs_fscache_get_super_cookie(s, NULL, data);
3048         }
3049
3050         mntroot = nfs4_get_root(s, mntfh, dev_name);
3051         if (IS_ERR(mntroot)) {
3052                 error = PTR_ERR(mntroot);
3053                 goto error_splat_super;
3054         }
3055         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3056                 dput(mntroot);
3057                 error = -ESTALE;
3058                 goto error_splat_super;
3059         }
3060
3061         s->s_flags |= MS_ACTIVE;
3062
3063         security_sb_clone_mnt_opts(data->sb, s);
3064
3065         nfs_free_fhandle(mntfh);
3066         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3067         return mntroot;
3068
3069 out_err_nosb:
3070         nfs_free_server(server);
3071 out_err_noserver:
3072         nfs_free_fhandle(mntfh);
3073 out_err_nofh:
3074         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3075         return ERR_PTR(error);
3076
3077 error_splat_super:
3078         if (server && !s->s_root)
3079                 bdi_unregister(&server->backing_dev_info);
3080 error_splat_bdi:
3081         deactivate_locked_super(s);
3082         nfs_free_fhandle(mntfh);
3083         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3084         return ERR_PTR(error);
3085 }
3086
3087 /*
3088  * Create an NFS4 server record on referral traversal
3089  */
3090 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3091                 int flags, const char *dev_name, void *raw_data)
3092 {
3093         struct nfs_clone_mount *data = raw_data;
3094         char *export_path;
3095         struct vfsmount *root_mnt;
3096         struct dentry *res;
3097
3098         dprintk("--> nfs4_referral_mount()\n");
3099
3100         export_path = data->mnt_path;
3101         data->mnt_path = "/";
3102
3103         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3104                         flags, data, data->hostname);
3105         data->mnt_path = export_path;
3106
3107         res = ERR_CAST(root_mnt);
3108         if (!IS_ERR(root_mnt))
3109                 res = nfs_follow_remote_path(root_mnt, export_path);
3110         dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3111                         IS_ERR(res) ? PTR_ERR(res) : 0,
3112                         IS_ERR(res) ? " [error]" : "");
3113         return res;
3114 }
3115
3116 #endif /* CONFIG_NFS_V4 */