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/namei.h>
  45 #include <linux/nfs_idmap.h>
  46 #include <linux/vfs.h>
  47 #include <linux/inet.h>
  48 #include <linux/in6.h>
  49 #include <linux/slab.h>
  50 #include <net/ipv6.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/nfs_xdr.h>
  53 #include <linux/magic.h>
  54 #include <linux/parser.h>
  55 #include <linux/nsproxy.h>
  56 #include <linux/rcupdate.h>
  57
  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_udp, Opt_tcp, Opt_rdma,
  84         Opt_acl, Opt_noacl,
  85         Opt_rdirplus, Opt_nordirplus,
  86         Opt_sharecache, Opt_nosharecache,
  87         Opt_resvport, Opt_noresvport,
  88         Opt_fscache, Opt_nofscache,
  89
  90         /* Mount options that take integer arguments */
  91         Opt_port,
  92         Opt_rsize, Opt_wsize, Opt_bsize,
  93         Opt_timeo, Opt_retrans,
  94         Opt_acregmin, Opt_acregmax,
  95         Opt_acdirmin, Opt_acdirmax,
  96         Opt_actimeo,
  97         Opt_namelen,
  98         Opt_mountport,
  99         Opt_mountvers,
 100         Opt_minorversion,
 101
 102         /* Mount options that take string arguments */
 103         Opt_nfsvers,
 104         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 105         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 106         Opt_lookupcache,
 107         Opt_fscache_uniq,
 108         Opt_local_lock,
 109
 110         /* Special mount options */
 111         Opt_userspace, Opt_deprecated, Opt_sloppy,
 112
 113         Opt_err
 114 };
 115
 116 static const match_table_t nfs_mount_option_tokens = {
 117         { Opt_userspace, "bg" },
 118         { Opt_userspace, "fg" },
 119         { Opt_userspace, "retry=%s" },
 120
 121         { Opt_sloppy, "sloppy" },
 122
 123         { Opt_soft, "soft" },
 124         { Opt_hard, "hard" },
 125         { Opt_deprecated, "intr" },
 126         { Opt_deprecated, "nointr" },
 127         { Opt_posix, "posix" },
 128         { Opt_noposix, "noposix" },
 129         { Opt_cto, "cto" },
 130         { Opt_nocto, "nocto" },
 131         { Opt_ac, "ac" },
 132         { Opt_noac, "noac" },
 133         { Opt_lock, "lock" },
 134         { Opt_nolock, "nolock" },
 135         { Opt_udp, "udp" },
 136         { Opt_tcp, "tcp" },
 137         { Opt_rdma, "rdma" },
 138         { Opt_acl, "acl" },
 139         { Opt_noacl, "noacl" },
 140         { Opt_rdirplus, "rdirplus" },
 141         { Opt_nordirplus, "nordirplus" },
 142         { Opt_sharecache, "sharecache" },
 143         { Opt_nosharecache, "nosharecache" },
 144         { Opt_resvport, "resvport" },
 145         { Opt_noresvport, "noresvport" },
 146         { Opt_fscache, "fsc" },
 147         { Opt_nofscache, "nofsc" },
 148
 149         { Opt_port, "port=%s" },
 150         { Opt_rsize, "rsize=%s" },
 151         { Opt_wsize, "wsize=%s" },
 152         { Opt_bsize, "bsize=%s" },
 153         { Opt_timeo, "timeo=%s" },
 154         { Opt_retrans, "retrans=%s" },
 155         { Opt_acregmin, "acregmin=%s" },
 156         { Opt_acregmax, "acregmax=%s" },
 157         { Opt_acdirmin, "acdirmin=%s" },
 158         { Opt_acdirmax, "acdirmax=%s" },
 159         { Opt_actimeo, "actimeo=%s" },
 160         { Opt_namelen, "namlen=%s" },
 161         { Opt_mountport, "mountport=%s" },
 162         { Opt_mountvers, "mountvers=%s" },
 163         { Opt_minorversion, "minorversion=%s" },
 164
 165         { Opt_nfsvers, "nfsvers=%s" },
 166         { Opt_nfsvers, "vers=%s" },
 167
 168         { Opt_sec, "sec=%s" },
 169         { Opt_proto, "proto=%s" },
 170         { Opt_mountproto, "mountproto=%s" },
 171         { Opt_addr, "addr=%s" },
 172         { Opt_clientaddr, "clientaddr=%s" },
 173         { Opt_mounthost, "mounthost=%s" },
 174         { Opt_mountaddr, "mountaddr=%s" },
 175
 176         { Opt_lookupcache, "lookupcache=%s" },
 177         { Opt_fscache_uniq, "fsc=%s" },
 178         { Opt_local_lock, "local_lock=%s" },
 179
 180         /* The following needs to be listed after all other options */
 181         { Opt_nfsvers, "v%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 enum {
 264         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 265         Opt_vers_4_1,
 266
 267         Opt_vers_err
 268 };
 269
 270 static match_table_t nfs_vers_tokens = {
 271         { Opt_vers_2, "2" },
 272         { Opt_vers_3, "3" },
 273         { Opt_vers_4, "4" },
 274         { Opt_vers_4_0, "4.0" },
 275         { Opt_vers_4_1, "4.1" },
 276
 277         { Opt_vers_err, NULL }
 278 };
 279
 280 static void nfs_umount_begin(struct super_block *);
 281 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 282 static int  nfs_show_options(struct seq_file *, struct dentry *);
 283 static int  nfs_show_devname(struct seq_file *, struct dentry *);
 284 static int  nfs_show_path(struct seq_file *, struct dentry *);
 285 static int  nfs_show_stats(struct seq_file *, struct dentry *);
 286 static struct dentry *nfs_fs_mount(struct file_system_type *,
 287                 int, const char *, void *);
 288 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 289                 int flags, const char *dev_name, void *raw_data);
 290 static void nfs_put_super(struct super_block *);
 291 static void nfs_kill_super(struct super_block *);
 292 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 293
 294 static struct file_system_type nfs_fs_type = {
 295         .owner          = THIS_MODULE,
 296         .name           = "nfs",
 297         .mount          = nfs_fs_mount,
 298         .kill_sb        = nfs_kill_super,
 299         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 300 };
 301
 302 struct file_system_type nfs_xdev_fs_type = {
 303         .owner          = THIS_MODULE,
 304         .name           = "nfs",
 305         .mount          = nfs_xdev_mount,
 306         .kill_sb        = nfs_kill_super,
 307         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 308 };
 309
 310 static const struct super_operations nfs_sops = {
 311         .alloc_inode    = nfs_alloc_inode,
 312         .destroy_inode  = nfs_destroy_inode,
 313         .write_inode    = nfs_write_inode,
 314         .put_super      = nfs_put_super,
 315         .statfs         = nfs_statfs,
 316         .evict_inode    = nfs_evict_inode,
 317         .umount_begin   = nfs_umount_begin,
 318         .show_options   = nfs_show_options,
 319         .show_devname   = nfs_show_devname,
 320         .show_path      = nfs_show_path,
 321         .show_stats     = nfs_show_stats,
 322         .remount_fs     = nfs_remount,
 323 };
 324
 325 #ifdef CONFIG_NFS_V4
 326 static int nfs4_validate_text_mount_data(void *options,
 327         struct nfs_parsed_mount_data *args, const char *dev_name);
 328 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 329         struct nfs_parsed_mount_data *data);
 330 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
 331         int flags, const char *dev_name, void *raw_data);
 332 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 333         int flags, const char *dev_name, void *raw_data);
 334 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
 335         int flags, const char *dev_name, void *raw_data);
 336 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 337         int flags, const char *dev_name, void *raw_data);
 338 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 339         int flags, const char *dev_name, void *raw_data);
 340 static void nfs4_kill_super(struct super_block *sb);
 341
 342 static struct file_system_type nfs4_fs_type = {
 343         .owner          = THIS_MODULE,
 344         .name           = "nfs4",
 345         .mount          = nfs4_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_fs_type = {
 351         .owner          = THIS_MODULE,
 352         .name           = "nfs4",
 353         .mount          = nfs4_remote_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_xdev_fs_type = {
 359         .owner          = THIS_MODULE,
 360         .name           = "nfs4",
 361         .mount          = nfs4_xdev_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 struct file_system_type nfs4_remote_referral_fs_type = {
 367         .owner          = THIS_MODULE,
 368         .name           = "nfs4",
 369         .mount          = nfs4_remote_referral_mount,
 370         .kill_sb        = nfs4_kill_super,
 371         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 372 };
 373
 374 struct file_system_type nfs4_referral_fs_type = {
 375         .owner          = THIS_MODULE,
 376         .name           = "nfs4",
 377         .mount          = nfs4_referral_mount,
 378         .kill_sb        = nfs4_kill_super,
 379         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 380 };
 381
 382 static const struct super_operations nfs4_sops = {
 383         .alloc_inode    = nfs_alloc_inode,
 384         .destroy_inode  = nfs_destroy_inode,
 385         .write_inode    = nfs_write_inode,
 386         .put_super      = nfs_put_super,
 387         .statfs         = nfs_statfs,
 388         .evict_inode    = nfs4_evict_inode,
 389         .umount_begin   = nfs_umount_begin,
 390         .show_options   = nfs_show_options,
 391         .show_devname   = nfs_show_devname,
 392         .show_path      = nfs_show_path,
 393         .show_stats     = nfs_show_stats,
 394         .remount_fs     = nfs_remount,
 395 };
 396 #endif
 397
 398 static struct shrinker acl_shrinker = {
 399         .shrink         = nfs_access_cache_shrinker,
 400         .seeks          = DEFAULT_SEEKS,
 401 };
 402
 403 /*
 404  * Register the NFS filesystems
 405  */
 406 int __init register_nfs_fs(void)
 407 {
 408         int ret;
 409
 410         ret = register_filesystem(&nfs_fs_type);
 411         if (ret < 0)
 412                 goto error_0;
 413
 414         ret = nfs_register_sysctl();
 415         if (ret < 0)
 416                 goto error_1;
 417 #ifdef CONFIG_NFS_V4
 418         ret = register_filesystem(&nfs4_fs_type);
 419         if (ret < 0)
 420                 goto error_2;
 421 #endif
 422         register_shrinker(&acl_shrinker);
 423         return 0;
 424
 425 #ifdef CONFIG_NFS_V4
 426 error_2:
 427         nfs_unregister_sysctl();
 428 #endif
 429 error_1:
 430         unregister_filesystem(&nfs_fs_type);
 431 error_0:
 432         return ret;
 433 }
 434
 435 /*
 436  * Unregister the NFS filesystems
 437  */
 438 void __exit unregister_nfs_fs(void)
 439 {
 440         unregister_shrinker(&acl_shrinker);
 441 #ifdef CONFIG_NFS_V4
 442         unregister_filesystem(&nfs4_fs_type);
 443 #endif
 444         nfs_unregister_sysctl();
 445         unregister_filesystem(&nfs_fs_type);
 446 }
 447
 448 void nfs_sb_active(struct super_block *sb)
 449 {
 450         struct nfs_server *server = NFS_SB(sb);
 451
 452         if (atomic_inc_return(&server->active) == 1)
 453                 atomic_inc(&sb->s_active);
 454 }
 455
 456 void nfs_sb_deactive(struct super_block *sb)
 457 {
 458         struct nfs_server *server = NFS_SB(sb);
 459
 460         if (atomic_dec_and_test(&server->active))
 461                 deactivate_super(sb);
 462 }
 463
 464 /*
 465  * Deliver file system statistics to userspace
 466  */
 467 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 468 {
 469         struct nfs_server *server = NFS_SB(dentry->d_sb);
 470         unsigned char blockbits;
 471         unsigned long blockres;
 472         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 473         struct nfs_fsstat res;
 474         int error = -ENOMEM;
 475
 476         res.fattr = nfs_alloc_fattr();
 477         if (res.fattr == NULL)
 478                 goto out_err;
 479
 480         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 481         if (unlikely(error == -ESTALE)) {
 482                 struct dentry *pd_dentry;
 483
 484                 pd_dentry = dget_parent(dentry);
 485                 if (pd_dentry != NULL) {
 486                         nfs_zap_caches(pd_dentry->d_inode);
 487                         dput(pd_dentry);
 488                 }
 489         }
 490         nfs_free_fattr(res.fattr);
 491         if (error < 0)
 492                 goto out_err;
 493
 494         buf->f_type = NFS_SUPER_MAGIC;
 495
 496         /*
 497          * Current versions of glibc do not correctly handle the
 498          * case where f_frsize != f_bsize.  Eventually we want to
 499          * report the value of wtmult in this field.
 500          */
 501         buf->f_frsize = dentry->d_sb->s_blocksize;
 502
 503         /*
 504          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 505          * are reported in units of f_frsize.  Linux hasn't had
 506          * an f_frsize field in its statfs struct until recently,
 507          * thus historically Linux's sys_statfs reports these
 508          * fields in units of f_bsize.
 509          */
 510         buf->f_bsize = dentry->d_sb->s_blocksize;
 511         blockbits = dentry->d_sb->s_blocksize_bits;
 512         blockres = (1 << blockbits) - 1;
 513         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 514         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 515         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 516
 517         buf->f_files = res.tfiles;
 518         buf->f_ffree = res.afiles;
 519
 520         buf->f_namelen = server->namelen;
 521
 522         return 0;
 523
 524  out_err:
 525         dprintk("%s: statfs error = %d\n", __func__, -error);
 526         return error;
 527 }
 528
 529 /*
 530  * Map the security flavour number to a name
 531  */
 532 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 533 {
 534         static const struct {
 535                 rpc_authflavor_t flavour;
 536                 const char *str;
 537         } sec_flavours[] = {
 538                 { RPC_AUTH_NULL, "null" },
 539                 { RPC_AUTH_UNIX, "sys" },
 540                 { RPC_AUTH_GSS_KRB5, "krb5" },
 541                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 542                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 543                 { RPC_AUTH_GSS_LKEY, "lkey" },
 544                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 545                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 546                 { RPC_AUTH_GSS_SPKM, "spkm" },
 547                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 548                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 549                 { UINT_MAX, "unknown" }
 550         };
 551         int i;
 552
 553         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 554                 if (sec_flavours[i].flavour == flavour)
 555                         break;
 556         }
 557         return sec_flavours[i].str;
 558 }
 559
 560 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 561                                   int showdefaults)
 562 {
 563         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 564
 565         seq_printf(m, ",mountproto=");
 566         switch (sap->sa_family) {
 567         case AF_INET:
 568                 switch (nfss->mountd_protocol) {
 569                 case IPPROTO_UDP:
 570                         seq_printf(m, RPCBIND_NETID_UDP);
 571                         break;
 572                 case IPPROTO_TCP:
 573                         seq_printf(m, RPCBIND_NETID_TCP);
 574                         break;
 575                 default:
 576                         if (showdefaults)
 577                                 seq_printf(m, "auto");
 578                 }
 579                 break;
 580         case AF_INET6:
 581                 switch (nfss->mountd_protocol) {
 582                 case IPPROTO_UDP:
 583                         seq_printf(m, RPCBIND_NETID_UDP6);
 584                         break;
 585                 case IPPROTO_TCP:
 586                         seq_printf(m, RPCBIND_NETID_TCP6);
 587                         break;
 588                 default:
 589                         if (showdefaults)
 590                                 seq_printf(m, "auto");
 591                 }
 592                 break;
 593         default:
 594                 if (showdefaults)
 595                         seq_printf(m, "auto");
 596         }
 597 }
 598
 599 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 600                                     int showdefaults)
 601 {
 602         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 603
 604         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 605                 return;
 606
 607         switch (sap->sa_family) {
 608         case AF_INET: {
 609                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 610                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 611                 break;
 612         }
 613         case AF_INET6: {
 614                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 615                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 616                 break;
 617         }
 618         default:
 619                 if (showdefaults)
 620                         seq_printf(m, ",mountaddr=unspecified");
 621         }
 622
 623         if (nfss->mountd_version || showdefaults)
 624                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 625         if ((nfss->mountd_port &&
 626                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 627                 showdefaults)
 628                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 629
 630         nfs_show_mountd_netid(m, nfss, showdefaults);
 631 }
 632
 633 #ifdef CONFIG_NFS_V4
 634 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 635                                     int showdefaults)
 636 {
 637         struct nfs_client *clp = nfss->nfs_client;
 638
 639         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 640 }
 641 #else
 642 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 643                                     int showdefaults)
 644 {
 645 }
 646 #endif
 647
 648 static void nfs_show_nfs_version(struct seq_file *m,
 649                 unsigned int version,
 650                 unsigned int minorversion)
 651 {
 652         seq_printf(m, ",vers=%u", version);
 653         if (version == 4)
 654                 seq_printf(m, ".%u", minorversion);
 655 }
 656
 657 /*
 658  * Describe the mount options in force on this server representation
 659  */
 660 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 661                                    int showdefaults)
 662 {
 663         static const struct proc_nfs_info {
 664                 int flag;
 665                 const char *str;
 666                 const char *nostr;
 667         } nfs_info[] = {
 668                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 669                 { NFS_MOUNT_POSIX, ",posix", "" },
 670                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 671                 { NFS_MOUNT_NOAC, ",noac", "" },
 672                 { NFS_MOUNT_NONLM, ",nolock", "" },
 673                 { NFS_MOUNT_NOACL, ",noacl", "" },
 674                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 675                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 676                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 677                 { 0, NULL, NULL }
 678         };
 679         const struct proc_nfs_info *nfs_infop;
 680         struct nfs_client *clp = nfss->nfs_client;
 681         u32 version = clp->rpc_ops->version;
 682         int local_flock, local_fcntl;
 683
 684         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 685         seq_printf(m, ",rsize=%u", nfss->rsize);
 686         seq_printf(m, ",wsize=%u", nfss->wsize);
 687         if (nfss->bsize != 0)
 688                 seq_printf(m, ",bsize=%u", nfss->bsize);
 689         seq_printf(m, ",namlen=%u", nfss->namelen);
 690         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 691                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 692         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 693                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 694         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 695                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 696         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 697                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 698         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 699                 if (nfss->flags & nfs_infop->flag)
 700                         seq_puts(m, nfs_infop->str);
 701                 else
 702                         seq_puts(m, nfs_infop->nostr);
 703         }
 704         rcu_read_lock();
 705         seq_printf(m, ",proto=%s",
 706                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 707         rcu_read_unlock();
 708         if (version == 4) {
 709                 if (nfss->port != NFS_PORT)
 710                         seq_printf(m, ",port=%u", nfss->port);
 711         } else
 712                 if (nfss->port)
 713                         seq_printf(m, ",port=%u", nfss->port);
 714
 715         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 716         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 717         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 718
 719         if (version != 4)
 720                 nfs_show_mountd_options(m, nfss, showdefaults);
 721         else
 722                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 723
 724         if (nfss->options & NFS_OPTION_FSCACHE)
 725                 seq_printf(m, ",fsc");
 726
 727         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 728                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 729                         seq_printf(m, ",lookupcache=none");
 730                 else
 731                         seq_printf(m, ",lookupcache=pos");
 732         }
 733
 734         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 735         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 736
 737         if (!local_flock && !local_fcntl)
 738                 seq_printf(m, ",local_lock=none");
 739         else if (local_flock && local_fcntl)
 740                 seq_printf(m, ",local_lock=all");
 741         else if (local_flock)
 742                 seq_printf(m, ",local_lock=flock");
 743         else
 744                 seq_printf(m, ",local_lock=posix");
 745 }
 746
 747 /*
 748  * Describe the mount options on this VFS mountpoint
 749  */
 750 static int nfs_show_options(struct seq_file *m, struct dentry *root)
 751 {
 752         struct nfs_server *nfss = NFS_SB(root->d_sb);
 753
 754         nfs_show_mount_options(m, nfss, 0);
 755
 756         rcu_read_lock();
 757         seq_printf(m, ",addr=%s",
 758                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 759                                                         RPC_DISPLAY_ADDR));
 760         rcu_read_unlock();
 761
 762         return 0;
 763 }
 764
 765 #ifdef CONFIG_NFS_V4
 766 #ifdef CONFIG_NFS_V4_1
 767 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 768 {
 769         if (nfs4_has_session(server->nfs_client))
 770                 seq_printf(m, ",sessions");
 771 }
 772 #else
 773 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 774 #endif
 775 #endif
 776
 777 #ifdef CONFIG_NFS_V4_1
 778 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 779 {
 780         seq_printf(m, ",pnfs=");
 781         if (server->pnfs_curr_ld)
 782                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 783         else
 784                 seq_printf(m, "not configured");
 785 }
 786
 787 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 788 {
 789         if (nfss->nfs_client && nfss->nfs_client->impl_id) {
 790                 struct nfs41_impl_id *impl_id = nfss->nfs_client->impl_id;
 791                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 792                            "date='%llu,%u'",
 793                            impl_id->name, impl_id->domain,
 794                            impl_id->date.seconds, impl_id->date.nseconds);
 795         }
 796 }
 797 #else
 798 #ifdef CONFIG_NFS_V4
 799 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 800 {
 801 }
 802 #endif
 803 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 804 {
 805 }
 806 #endif
 807
 808 static int nfs_show_devname(struct seq_file *m, struct dentry *root)
 809 {
 810         char *page = (char *) __get_free_page(GFP_KERNEL);
 811         char *devname, *dummy;
 812         int err = 0;
 813         if (!page)
 814                 return -ENOMEM;
 815         devname = nfs_path(&dummy, root, page, PAGE_SIZE);
 816         if (IS_ERR(devname))
 817                 err = PTR_ERR(devname);
 818         else
 819                 seq_escape(m, devname, " \t\n\\");
 820         free_page((unsigned long)page);
 821         return err;
 822 }
 823
 824 static int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 825 {
 826         seq_puts(m, "/");
 827         return 0;
 828 }
 829
 830 /*
 831  * Present statistical information for this VFS mountpoint
 832  */
 833 static int nfs_show_stats(struct seq_file *m, struct dentry *root)
 834 {
 835         int i, cpu;
 836         struct nfs_server *nfss = NFS_SB(root->d_sb);
 837         struct rpc_auth *auth = nfss->client->cl_auth;
 838         struct nfs_iostats totals = { };
 839
 840         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 841
 842         /*
 843          * Display all mount option settings
 844          */
 845         seq_printf(m, "\n\topts:\t");
 846         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 847         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 848         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 849         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 850         nfs_show_mount_options(m, nfss, 1);
 851
 852         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 853
 854         show_implementation_id(m, nfss);
 855
 856         seq_printf(m, "\n\tcaps:\t");
 857         seq_printf(m, "caps=0x%x", nfss->caps);
 858         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 859         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 860         seq_printf(m, ",bsize=%u", nfss->bsize);
 861         seq_printf(m, ",namlen=%u", nfss->namelen);
 862
 863 #ifdef CONFIG_NFS_V4
 864         if (nfss->nfs_client->rpc_ops->version == 4) {
 865                 seq_printf(m, "\n\tnfsv4:\t");
 866                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 867                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 868                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 869                 show_sessions(m, nfss);
 870                 show_pnfs(m, nfss);
 871         }
 872 #endif
 873
 874         /*
 875          * Display security flavor in effect for this mount
 876          */
 877         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 878         if (auth->au_flavor)
 879                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 880
 881         /*
 882          * Display superblock I/O counters
 883          */
 884         for_each_possible_cpu(cpu) {
 885                 struct nfs_iostats *stats;
 886
 887                 preempt_disable();
 888                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 889
 890                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 891                         totals.events[i] += stats->events[i];
 892                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 893                         totals.bytes[i] += stats->bytes[i];
 894 #ifdef CONFIG_NFS_FSCACHE
 895                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 896                         totals.fscache[i] += stats->fscache[i];
 897 #endif
 898
 899                 preempt_enable();
 900         }
 901
 902         seq_printf(m, "\n\tevents:\t");
 903         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 904                 seq_printf(m, "%lu ", totals.events[i]);
 905         seq_printf(m, "\n\tbytes:\t");
 906         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 907                 seq_printf(m, "%Lu ", totals.bytes[i]);
 908 #ifdef CONFIG_NFS_FSCACHE
 909         if (nfss->options & NFS_OPTION_FSCACHE) {
 910                 seq_printf(m, "\n\tfsc:\t");
 911                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 912                         seq_printf(m, "%Lu ", totals.bytes[i]);
 913         }
 914 #endif
 915         seq_printf(m, "\n");
 916
 917         rpc_print_iostats(m, nfss->client);
 918
 919         return 0;
 920 }
 921
 922 /*
 923  * Begin unmount by attempting to remove all automounted mountpoints we added
 924  * in response to xdev traversals and referrals
 925  */
 926 static void nfs_umount_begin(struct super_block *sb)
 927 {
 928         struct nfs_server *server;
 929         struct rpc_clnt *rpc;
 930
 931         server = NFS_SB(sb);
 932         /* -EIO all pending I/O */
 933         rpc = server->client_acl;
 934         if (!IS_ERR(rpc))
 935                 rpc_killall_tasks(rpc);
 936         rpc = server->client;
 937         if (!IS_ERR(rpc))
 938                 rpc_killall_tasks(rpc);
 939 }
 940
 941 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
 942 {
 943         struct nfs_parsed_mount_data *data;
 944
 945         data = kzalloc(sizeof(*data), GFP_KERNEL);
 946         if (data) {
 947                 data->acregmin          = NFS_DEF_ACREGMIN;
 948                 data->acregmax          = NFS_DEF_ACREGMAX;
 949                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 950                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 951                 data->mount_server.port = NFS_UNSPEC_PORT;
 952                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 953                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 954                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 955                 data->auth_flavor_len   = 1;
 956                 data->version           = version;
 957                 data->minorversion      = 0;
 958                 data->net               = current->nsproxy->net_ns;
 959                 security_init_mnt_opts(&data->lsm_opts);
 960         }
 961         return data;
 962 }
 963
 964 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 965 {
 966         if (data) {
 967                 kfree(data->client_address);
 968                 kfree(data->mount_server.hostname);
 969                 kfree(data->nfs_server.export_path);
 970                 kfree(data->nfs_server.hostname);
 971                 kfree(data->fscache_uniq);
 972                 security_free_mnt_opts(&data->lsm_opts);
 973                 kfree(data);
 974         }
 975 }
 976
 977 /*
 978  * Sanity-check a server address provided by the mount command.
 979  *
 980  * Address family must be initialized, and address must not be
 981  * the ANY address for that family.
 982  */
 983 static int nfs_verify_server_address(struct sockaddr *addr)
 984 {
 985         switch (addr->sa_family) {
 986         case AF_INET: {
 987                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 988                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 989         }
 990         case AF_INET6: {
 991                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 992                 return !ipv6_addr_any(sa);
 993         }
 994         }
 995
 996         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 997         return 0;
 998 }
 999
1000 /*
1001  * Select between a default port value and a user-specified port value.
1002  * If a zero value is set, then autobind will be used.
1003  */
1004 static void nfs_set_port(struct sockaddr *sap, int *port,
1005                                  const unsigned short default_port)
1006 {
1007         if (*port == NFS_UNSPEC_PORT)
1008                 *port = default_port;
1009
1010         rpc_set_port(sap, *port);
1011 }
1012
1013 /*
1014  * Sanity check the NFS transport protocol.
1015  *
1016  */
1017 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1018 {
1019         switch (mnt->nfs_server.protocol) {
1020         case XPRT_TRANSPORT_UDP:
1021         case XPRT_TRANSPORT_TCP:
1022         case XPRT_TRANSPORT_RDMA:
1023                 break;
1024         default:
1025                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1026         }
1027 }
1028
1029 /*
1030  * For text based NFSv2/v3 mounts, the mount protocol transport default
1031  * settings should depend upon the specified NFS transport.
1032  */
1033 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1034 {
1035         nfs_validate_transport_protocol(mnt);
1036
1037         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1038             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1039                         return;
1040         switch (mnt->nfs_server.protocol) {
1041         case XPRT_TRANSPORT_UDP:
1042                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1043                 break;
1044         case XPRT_TRANSPORT_TCP:
1045         case XPRT_TRANSPORT_RDMA:
1046                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1047         }
1048 }
1049
1050 /*
1051  * Parse the value of the 'sec=' option.
1052  */
1053 static int nfs_parse_security_flavors(char *value,
1054                                       struct nfs_parsed_mount_data *mnt)
1055 {
1056         substring_t args[MAX_OPT_ARGS];
1057
1058         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1059
1060         switch (match_token(value, nfs_secflavor_tokens, args)) {
1061         case Opt_sec_none:
1062                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1063                 break;
1064         case Opt_sec_sys:
1065                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1066                 break;
1067         case Opt_sec_krb5:
1068                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1069                 break;
1070         case Opt_sec_krb5i:
1071                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1072                 break;
1073         case Opt_sec_krb5p:
1074                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1075                 break;
1076         case Opt_sec_lkey:
1077                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1078                 break;
1079         case Opt_sec_lkeyi:
1080                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1081                 break;
1082         case Opt_sec_lkeyp:
1083                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1084                 break;
1085         case Opt_sec_spkm:
1086                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1087                 break;
1088         case Opt_sec_spkmi:
1089                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1090                 break;
1091         case Opt_sec_spkmp:
1092                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1093                 break;
1094         default:
1095                 return 0;
1096         }
1097
1098         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1099         mnt->auth_flavor_len = 1;
1100         return 1;
1101 }
1102
1103 static int nfs_parse_version_string(char *string,
1104                 struct nfs_parsed_mount_data *mnt,
1105                 substring_t *args)
1106 {
1107         mnt->flags &= ~NFS_MOUNT_VER3;
1108         switch (match_token(string, nfs_vers_tokens, args)) {
1109         case Opt_vers_2:
1110                 mnt->version = 2;
1111                 break;
1112         case Opt_vers_3:
1113                 mnt->flags |= NFS_MOUNT_VER3;
1114                 mnt->version = 3;
1115                 break;
1116         case Opt_vers_4:
1117                 /* Backward compatibility option. In future,
1118                  * the mount program should always supply
1119                  * a NFSv4 minor version number.
1120                  */
1121                 mnt->version = 4;
1122                 break;
1123         case Opt_vers_4_0:
1124                 mnt->version = 4;
1125                 mnt->minorversion = 0;
1126                 break;
1127         case Opt_vers_4_1:
1128                 mnt->version = 4;
1129                 mnt->minorversion = 1;
1130                 break;
1131         default:
1132                 return 0;
1133         }
1134         return 1;
1135 }
1136
1137 static int nfs_get_option_str(substring_t args[], char **option)
1138 {
1139         kfree(*option);
1140         *option = match_strdup(args);
1141         return !option;
1142 }
1143
1144 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1145 {
1146         int rc;
1147         char *string;
1148
1149         string = match_strdup(args);
1150         if (string == NULL)
1151                 return -ENOMEM;
1152         rc = strict_strtoul(string, 10, option);
1153         kfree(string);
1154
1155         return rc;
1156 }
1157
1158 /*
1159  * Error-check and convert a string of mount options from user space into
1160  * a data structure.  The whole mount string is processed; bad options are
1161  * skipped as they are encountered.  If there were no errors, return 1;
1162  * otherwise return 0 (zero).
1163  */
1164 static int nfs_parse_mount_options(char *raw,
1165                                    struct nfs_parsed_mount_data *mnt)
1166 {
1167         char *p, *string, *secdata;
1168         int rc, sloppy = 0, invalid_option = 0;
1169         unsigned short protofamily = AF_UNSPEC;
1170         unsigned short mountfamily = AF_UNSPEC;
1171
1172         if (!raw) {
1173                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1174                 return 1;
1175         }
1176         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1177
1178         secdata = alloc_secdata();
1179         if (!secdata)
1180                 goto out_nomem;
1181
1182         rc = security_sb_copy_data(raw, secdata);
1183         if (rc)
1184                 goto out_security_failure;
1185
1186         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1187         if (rc)
1188                 goto out_security_failure;
1189
1190         free_secdata(secdata);
1191
1192         while ((p = strsep(&raw, ",")) != NULL) {
1193                 substring_t args[MAX_OPT_ARGS];
1194                 unsigned long option;
1195                 int token;
1196
1197                 if (!*p)
1198                         continue;
1199
1200                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1201
1202                 token = match_token(p, nfs_mount_option_tokens, args);
1203                 switch (token) {
1204
1205                 /*
1206                  * boolean options:  foo/nofoo
1207                  */
1208                 case Opt_soft:
1209                         mnt->flags |= NFS_MOUNT_SOFT;
1210                         break;
1211                 case Opt_hard:
1212                         mnt->flags &= ~NFS_MOUNT_SOFT;
1213                         break;
1214                 case Opt_posix:
1215                         mnt->flags |= NFS_MOUNT_POSIX;
1216                         break;
1217                 case Opt_noposix:
1218                         mnt->flags &= ~NFS_MOUNT_POSIX;
1219                         break;
1220                 case Opt_cto:
1221                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1222                         break;
1223                 case Opt_nocto:
1224                         mnt->flags |= NFS_MOUNT_NOCTO;
1225                         break;
1226                 case Opt_ac:
1227                         mnt->flags &= ~NFS_MOUNT_NOAC;
1228                         break;
1229                 case Opt_noac:
1230                         mnt->flags |= NFS_MOUNT_NOAC;
1231                         break;
1232                 case Opt_lock:
1233                         mnt->flags &= ~NFS_MOUNT_NONLM;
1234                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1235                                         NFS_MOUNT_LOCAL_FCNTL);
1236                         break;
1237                 case Opt_nolock:
1238                         mnt->flags |= NFS_MOUNT_NONLM;
1239                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1240                                        NFS_MOUNT_LOCAL_FCNTL);
1241                         break;
1242                 case Opt_udp:
1243                         mnt->flags &= ~NFS_MOUNT_TCP;
1244                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1245                         break;
1246                 case Opt_tcp:
1247                         mnt->flags |= NFS_MOUNT_TCP;
1248                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1249                         break;
1250                 case Opt_rdma:
1251                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1252                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1253                         xprt_load_transport(p);
1254                         break;
1255                 case Opt_acl:
1256                         mnt->flags &= ~NFS_MOUNT_NOACL;
1257                         break;
1258                 case Opt_noacl:
1259                         mnt->flags |= NFS_MOUNT_NOACL;
1260                         break;
1261                 case Opt_rdirplus:
1262                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1263                         break;
1264                 case Opt_nordirplus:
1265                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1266                         break;
1267                 case Opt_sharecache:
1268                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1269                         break;
1270                 case Opt_nosharecache:
1271                         mnt->flags |= NFS_MOUNT_UNSHARED;
1272                         break;
1273                 case Opt_resvport:
1274                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1275                         break;
1276                 case Opt_noresvport:
1277                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1278                         break;
1279                 case Opt_fscache:
1280                         mnt->options |= NFS_OPTION_FSCACHE;
1281                         kfree(mnt->fscache_uniq);
1282                         mnt->fscache_uniq = NULL;
1283                         break;
1284                 case Opt_nofscache:
1285                         mnt->options &= ~NFS_OPTION_FSCACHE;
1286                         kfree(mnt->fscache_uniq);
1287                         mnt->fscache_uniq = NULL;
1288                         break;
1289
1290                 /*
1291                  * options that take numeric values
1292                  */
1293                 case Opt_port:
1294                         if (nfs_get_option_ul(args, &option) ||
1295                             option > USHRT_MAX)
1296                                 goto out_invalid_value;
1297                         mnt->nfs_server.port = option;
1298                         break;
1299                 case Opt_rsize:
1300                         if (nfs_get_option_ul(args, &option))
1301                                 goto out_invalid_value;
1302                         mnt->rsize = option;
1303                         break;
1304                 case Opt_wsize:
1305                         if (nfs_get_option_ul(args, &option))
1306                                 goto out_invalid_value;
1307                         mnt->wsize = option;
1308                         break;
1309                 case Opt_bsize:
1310                         if (nfs_get_option_ul(args, &option))
1311                                 goto out_invalid_value;
1312                         mnt->bsize = option;
1313                         break;
1314                 case Opt_timeo:
1315                         if (nfs_get_option_ul(args, &option) || option == 0)
1316                                 goto out_invalid_value;
1317                         mnt->timeo = option;
1318                         break;
1319                 case Opt_retrans:
1320                         if (nfs_get_option_ul(args, &option) || option == 0)
1321                                 goto out_invalid_value;
1322                         mnt->retrans = option;
1323                         break;
1324                 case Opt_acregmin:
1325                         if (nfs_get_option_ul(args, &option))
1326                                 goto out_invalid_value;
1327                         mnt->acregmin = option;
1328                         break;
1329                 case Opt_acregmax:
1330                         if (nfs_get_option_ul(args, &option))
1331                                 goto out_invalid_value;
1332                         mnt->acregmax = option;
1333                         break;
1334                 case Opt_acdirmin:
1335                         if (nfs_get_option_ul(args, &option))
1336                                 goto out_invalid_value;
1337                         mnt->acdirmin = option;
1338                         break;
1339                 case Opt_acdirmax:
1340                         if (nfs_get_option_ul(args, &option))
1341                                 goto out_invalid_value;
1342                         mnt->acdirmax = option;
1343                         break;
1344                 case Opt_actimeo:
1345                         if (nfs_get_option_ul(args, &option))
1346                                 goto out_invalid_value;
1347                         mnt->acregmin = mnt->acregmax =
1348                         mnt->acdirmin = mnt->acdirmax = option;
1349                         break;
1350                 case Opt_namelen:
1351                         if (nfs_get_option_ul(args, &option))
1352                                 goto out_invalid_value;
1353                         mnt->namlen = option;
1354                         break;
1355                 case Opt_mountport:
1356                         if (nfs_get_option_ul(args, &option) ||
1357                             option > USHRT_MAX)
1358                                 goto out_invalid_value;
1359                         mnt->mount_server.port = option;
1360                         break;
1361                 case Opt_mountvers:
1362                         if (nfs_get_option_ul(args, &option) ||
1363                             option < NFS_MNT_VERSION ||
1364                             option > NFS_MNT3_VERSION)
1365                                 goto out_invalid_value;
1366                         mnt->mount_server.version = option;
1367                         break;
1368                 case Opt_minorversion:
1369                         if (nfs_get_option_ul(args, &option))
1370                                 goto out_invalid_value;
1371                         if (option > NFS4_MAX_MINOR_VERSION)
1372                                 goto out_invalid_value;
1373                         mnt->minorversion = option;
1374                         break;
1375
1376                 /*
1377                  * options that take text values
1378                  */
1379                 case Opt_nfsvers:
1380                         string = match_strdup(args);
1381                         if (string == NULL)
1382                                 goto out_nomem;
1383                         rc = nfs_parse_version_string(string, mnt, args);
1384                         kfree(string);
1385                         if (!rc)
1386                                 goto out_invalid_value;
1387                         break;
1388                 case Opt_sec:
1389                         string = match_strdup(args);
1390                         if (string == NULL)
1391                                 goto out_nomem;
1392                         rc = nfs_parse_security_flavors(string, mnt);
1393                         kfree(string);
1394                         if (!rc) {
1395                                 dfprintk(MOUNT, "NFS:   unrecognized "
1396                                                 "security flavor\n");
1397                                 return 0;
1398                         }
1399                         break;
1400                 case Opt_proto:
1401                         string = match_strdup(args);
1402                         if (string == NULL)
1403                                 goto out_nomem;
1404                         token = match_token(string,
1405                                             nfs_xprt_protocol_tokens, args);
1406
1407                         protofamily = AF_INET;
1408                         switch (token) {
1409                         case Opt_xprt_udp6:
1410                                 protofamily = AF_INET6;
1411                         case Opt_xprt_udp:
1412                                 mnt->flags &= ~NFS_MOUNT_TCP;
1413                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1414                                 break;
1415                         case Opt_xprt_tcp6:
1416                                 protofamily = AF_INET6;
1417                         case Opt_xprt_tcp:
1418                                 mnt->flags |= NFS_MOUNT_TCP;
1419                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1420                                 break;
1421                         case Opt_xprt_rdma:
1422                                 /* vector side protocols to TCP */
1423                                 mnt->flags |= NFS_MOUNT_TCP;
1424                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1425                                 xprt_load_transport(string);
1426                                 break;
1427                         default:
1428                                 dfprintk(MOUNT, "NFS:   unrecognized "
1429                                                 "transport protocol\n");
1430                                 kfree(string);
1431                                 return 0;
1432                         }
1433                         kfree(string);
1434                         break;
1435                 case Opt_mountproto:
1436                         string = match_strdup(args);
1437                         if (string == NULL)
1438                                 goto out_nomem;
1439                         token = match_token(string,
1440                                             nfs_xprt_protocol_tokens, args);
1441                         kfree(string);
1442
1443                         mountfamily = AF_INET;
1444                         switch (token) {
1445                         case Opt_xprt_udp6:
1446                                 mountfamily = AF_INET6;
1447                         case Opt_xprt_udp:
1448                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1449                                 break;
1450                         case Opt_xprt_tcp6:
1451                                 mountfamily = AF_INET6;
1452                         case Opt_xprt_tcp:
1453                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1454                                 break;
1455                         case Opt_xprt_rdma: /* not used for side protocols */
1456                         default:
1457                                 dfprintk(MOUNT, "NFS:   unrecognized "
1458                                                 "transport protocol\n");
1459                                 return 0;
1460                         }
1461                         break;
1462                 case Opt_addr:
1463                         string = match_strdup(args);
1464                         if (string == NULL)
1465                                 goto out_nomem;
1466                         mnt->nfs_server.addrlen =
1467                                 rpc_pton(mnt->net, string, strlen(string),
1468                                         (struct sockaddr *)
1469                                         &mnt->nfs_server.address,
1470                                         sizeof(mnt->nfs_server.address));
1471                         kfree(string);
1472                         if (mnt->nfs_server.addrlen == 0)
1473                                 goto out_invalid_address;
1474                         break;
1475                 case Opt_clientaddr:
1476                         if (nfs_get_option_str(args, &mnt->client_address))
1477                                 goto out_nomem;
1478                         break;
1479                 case Opt_mounthost:
1480                         if (nfs_get_option_str(args,
1481                                                &mnt->mount_server.hostname))
1482                                 goto out_nomem;
1483                         break;
1484                 case Opt_mountaddr:
1485                         string = match_strdup(args);
1486                         if (string == NULL)
1487                                 goto out_nomem;
1488                         mnt->mount_server.addrlen =
1489                                 rpc_pton(mnt->net, string, strlen(string),
1490                                         (struct sockaddr *)
1491                                         &mnt->mount_server.address,
1492                                         sizeof(mnt->mount_server.address));
1493                         kfree(string);
1494                         if (mnt->mount_server.addrlen == 0)
1495                                 goto out_invalid_address;
1496                         break;
1497                 case Opt_lookupcache:
1498                         string = match_strdup(args);
1499                         if (string == NULL)
1500                                 goto out_nomem;
1501                         token = match_token(string,
1502                                         nfs_lookupcache_tokens, args);
1503                         kfree(string);
1504                         switch (token) {
1505                                 case Opt_lookupcache_all:
1506                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1507                                         break;
1508                                 case Opt_lookupcache_positive:
1509                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1510                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1511                                         break;
1512                                 case Opt_lookupcache_none:
1513                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1514                                         break;
1515                                 default:
1516                                         dfprintk(MOUNT, "NFS:   invalid "
1517                                                         "lookupcache argument\n");
1518                                         return 0;
1519                         };
1520                         break;
1521                 case Opt_fscache_uniq:
1522                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1523                                 goto out_nomem;
1524                         mnt->options |= NFS_OPTION_FSCACHE;
1525                         break;
1526                 case Opt_local_lock:
1527                         string = match_strdup(args);
1528                         if (string == NULL)
1529                                 goto out_nomem;
1530                         token = match_token(string, nfs_local_lock_tokens,
1531                                         args);
1532                         kfree(string);
1533                         switch (token) {
1534                         case Opt_local_lock_all:
1535                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1536                                                NFS_MOUNT_LOCAL_FCNTL);
1537                                 break;
1538                         case Opt_local_lock_flock:
1539                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1540                                 break;
1541                         case Opt_local_lock_posix:
1542                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1543                                 break;
1544                         case Opt_local_lock_none:
1545                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1546                                                 NFS_MOUNT_LOCAL_FCNTL);
1547                                 break;
1548                         default:
1549                                 dfprintk(MOUNT, "NFS:   invalid "
1550                                                 "local_lock argument\n");
1551                                 return 0;
1552                         };
1553                         break;
1554
1555                 /*
1556                  * Special options
1557                  */
1558                 case Opt_sloppy:
1559                         sloppy = 1;
1560                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1561                         break;
1562                 case Opt_userspace:
1563                 case Opt_deprecated:
1564                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1565                                         "'%s'\n", p);
1566                         break;
1567
1568                 default:
1569                         invalid_option = 1;
1570                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1571                                         "'%s'\n", p);
1572                 }
1573         }
1574
1575         if (!sloppy && invalid_option)
1576                 return 0;
1577
1578         if (mnt->minorversion && mnt->version != 4)
1579                 goto out_minorversion_mismatch;
1580
1581         /*
1582          * verify that any proto=/mountproto= options match the address
1583          * familiies in the addr=/mountaddr= options.
1584          */
1585         if (protofamily != AF_UNSPEC &&
1586             protofamily != mnt->nfs_server.address.ss_family)
1587                 goto out_proto_mismatch;
1588
1589         if (mountfamily != AF_UNSPEC) {
1590                 if (mnt->mount_server.addrlen) {
1591                         if (mountfamily != mnt->mount_server.address.ss_family)
1592                                 goto out_mountproto_mismatch;
1593                 } else {
1594                         if (mountfamily != mnt->nfs_server.address.ss_family)
1595                                 goto out_mountproto_mismatch;
1596                 }
1597         }
1598
1599         return 1;
1600
1601 out_mountproto_mismatch:
1602         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1603                          "option\n");
1604         return 0;
1605 out_proto_mismatch:
1606         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1607         return 0;
1608 out_invalid_address:
1609         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1610         return 0;
1611 out_invalid_value:
1612         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1613         return 0;
1614 out_minorversion_mismatch:
1615         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1616                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1617         return 0;
1618 out_nomem:
1619         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1620         return 0;
1621 out_security_failure:
1622         free_secdata(secdata);
1623         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1624         return 0;
1625 }
1626
1627 /*
1628  * Match the requested auth flavors with the list returned by
1629  * the server.  Returns zero and sets the mount's authentication
1630  * flavor on success; returns -EACCES if server does not support
1631  * the requested flavor.
1632  */
1633 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1634                              struct nfs_mount_request *request)
1635 {
1636         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1637
1638         /*
1639          * Certain releases of Linux's mountd return an empty
1640          * flavor list.  To prevent behavioral regression with
1641          * these servers (ie. rejecting mounts that used to
1642          * succeed), revert to pre-2.6.32 behavior (no checking)
1643          * if the returned flavor list is empty.
1644          */
1645         if (server_authlist_len == 0)
1646                 return 0;
1647
1648         /*
1649          * We avoid sophisticated negotiating here, as there are
1650          * plenty of cases where we can get it wrong, providing
1651          * either too little or too much security.
1652          *
1653          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1654          * flavor listed first.  However, some servers list
1655          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1656          * preferred default, in args->auth_flavors[0] if user
1657          * didn't specify sec= mount option.
1658          */
1659         for (i = 0; i < args->auth_flavor_len; i++)
1660                 for (j = 0; j < server_authlist_len; j++)
1661                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1662                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1663                                         request->auth_flavs[j]);
1664                                 args->auth_flavors[0] = request->auth_flavs[j];
1665                                 return 0;
1666                         }
1667
1668         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1669         nfs_umount(request);
1670         return -EACCES;
1671 }
1672
1673 /*
1674  * Use the remote server's MOUNT service to request the NFS file handle
1675  * corresponding to the provided path.
1676  */
1677 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1678                          struct nfs_fh *root_fh)
1679 {
1680         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1681         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1682         struct nfs_mount_request request = {
1683                 .sap            = (struct sockaddr *)
1684                                                 &args->mount_server.address,
1685                 .dirpath        = args->nfs_server.export_path,
1686                 .protocol       = args->mount_server.protocol,
1687                 .fh             = root_fh,
1688                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1689                 .auth_flav_len  = &server_authlist_len,
1690                 .auth_flavs     = server_authlist,
1691                 .net            = args->net,
1692         };
1693         int status;
1694
1695         if (args->mount_server.version == 0) {
1696                 switch (args->version) {
1697                         default:
1698                                 args->mount_server.version = NFS_MNT3_VERSION;
1699                                 break;
1700                         case 2:
1701                                 args->mount_server.version = NFS_MNT_VERSION;
1702                 }
1703         }
1704         request.version = args->mount_server.version;
1705
1706         if (args->mount_server.hostname)
1707                 request.hostname = args->mount_server.hostname;
1708         else
1709                 request.hostname = args->nfs_server.hostname;
1710
1711         /*
1712          * Construct the mount server's address.
1713          */
1714         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1715                 memcpy(request.sap, &args->nfs_server.address,
1716                        args->nfs_server.addrlen);
1717                 args->mount_server.addrlen = args->nfs_server.addrlen;
1718         }
1719         request.salen = args->mount_server.addrlen;
1720         nfs_set_port(request.sap, &args->mount_server.port, 0);
1721
1722         /*
1723          * Now ask the mount server to map our export path
1724          * to a file handle.
1725          */
1726         status = nfs_mount(&request);
1727         if (status != 0) {
1728                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1729                                 request.hostname, status);
1730                 return status;
1731         }
1732
1733         /*
1734          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1735          */
1736         if (args->mount_server.version != NFS_MNT3_VERSION)
1737                 return 0;
1738         return nfs_walk_authlist(args, &request);
1739 }
1740
1741 /*
1742  * Split "dev_name" into "hostname:export_path".
1743  *
1744  * The leftmost colon demarks the split between the server's hostname
1745  * and the export path.  If the hostname starts with a left square
1746  * bracket, then it may contain colons.
1747  *
1748  * Note: caller frees hostname and export path, even on error.
1749  */
1750 static int nfs_parse_devname(const char *dev_name,
1751                              char **hostname, size_t maxnamlen,
1752                              char **export_path, size_t maxpathlen)
1753 {
1754         size_t len;
1755         char *end;
1756
1757         /* Is the host name protected with square brakcets? */
1758         if (*dev_name == '[') {
1759                 end = strchr(++dev_name, ']');
1760                 if (end == NULL || end[1] != ':')
1761                         goto out_bad_devname;
1762
1763                 len = end - dev_name;
1764                 end++;
1765         } else {
1766                 char *comma;
1767
1768                 end = strchr(dev_name, ':');
1769                 if (end == NULL)
1770                         goto out_bad_devname;
1771                 len = end - dev_name;
1772
1773                 /* kill possible hostname list: not supported */
1774                 comma = strchr(dev_name, ',');
1775                 if (comma != NULL && comma < end)
1776                         *comma = 0;
1777         }
1778
1779         if (len > maxnamlen)
1780                 goto out_hostname;
1781
1782         /* N.B. caller will free nfs_server.hostname in all cases */
1783         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1784         if (*hostname == NULL)
1785                 goto out_nomem;
1786         len = strlen(++end);
1787         if (len > maxpathlen)
1788                 goto out_path;
1789         *export_path = kstrndup(end, len, GFP_KERNEL);
1790         if (!*export_path)
1791                 goto out_nomem;
1792
1793         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1794         return 0;
1795
1796 out_bad_devname:
1797         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1798         return -EINVAL;
1799
1800 out_nomem:
1801         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1802         return -ENOMEM;
1803
1804 out_hostname:
1805         dfprintk(MOUNT, "NFS: server hostname too long\n");
1806         return -ENAMETOOLONG;
1807
1808 out_path:
1809         dfprintk(MOUNT, "NFS: export pathname too long\n");
1810         return -ENAMETOOLONG;
1811 }
1812
1813 /*
1814  * Validate the NFS2/NFS3 mount data
1815  * - fills in the mount root filehandle
1816  *
1817  * For option strings, user space handles the following behaviors:
1818  *
1819  * + DNS: mapping server host name to IP address ("addr=" option)
1820  *
1821  * + failure mode: how to behave if a mount request can't be handled
1822  *   immediately ("fg/bg" option)
1823  *
1824  * + retry: how often to retry a mount request ("retry=" option)
1825  *
1826  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1827  *   mountproto=tcp after mountproto=udp, and so on
1828  */
1829 static int nfs_validate_mount_data(void *options,
1830                                    struct nfs_parsed_mount_data *args,
1831                                    struct nfs_fh *mntfh,
1832                                    const char *dev_name)
1833 {
1834         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1835         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1836
1837         if (data == NULL)
1838                 goto out_no_data;
1839
1840         switch (data->version) {
1841         case 1:
1842                 data->namlen = 0;
1843         case 2:
1844                 data->bsize = 0;
1845         case 3:
1846                 if (data->flags & NFS_MOUNT_VER3)
1847                         goto out_no_v3;
1848                 data->root.size = NFS2_FHSIZE;
1849                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1850         case 4:
1851                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1852                         goto out_no_sec;
1853         case 5:
1854                 memset(data->context, 0, sizeof(data->context));
1855         case 6:
1856                 if (data->flags & NFS_MOUNT_VER3) {
1857                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1858                                 goto out_invalid_fh;
1859                         mntfh->size = data->root.size;
1860                         args->version = 3;
1861                 } else {
1862                         mntfh->size = NFS2_FHSIZE;
1863                         args->version = 2;
1864                 }
1865
1866
1867                 memcpy(mntfh->data, data->root.data, mntfh->size);
1868                 if (mntfh->size < sizeof(mntfh->data))
1869                         memset(mntfh->data + mntfh->size, 0,
1870                                sizeof(mntfh->data) - mntfh->size);
1871
1872                 /*
1873                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1874                  * can deal with.
1875                  */
1876                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1877                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1878                 args->rsize             = data->rsize;
1879                 args->wsize             = data->wsize;
1880                 args->timeo             = data->timeo;
1881                 args->retrans           = data->retrans;
1882                 args->acregmin          = data->acregmin;
1883                 args->acregmax          = data->acregmax;
1884                 args->acdirmin          = data->acdirmin;
1885                 args->acdirmax          = data->acdirmax;
1886
1887                 memcpy(sap, &data->addr, sizeof(data->addr));
1888                 args->nfs_server.addrlen = sizeof(data->addr);
1889                 if (!nfs_verify_server_address(sap))
1890                         goto out_no_address;
1891
1892                 if (!(data->flags & NFS_MOUNT_TCP))
1893                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1894                 /* N.B. caller will free nfs_server.hostname in all cases */
1895                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1896                 args->namlen            = data->namlen;
1897                 args->bsize             = data->bsize;
1898
1899                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1900                         args->auth_flavors[0] = data->pseudoflavor;
1901                 if (!args->nfs_server.hostname)
1902                         goto out_nomem;
1903
1904                 if (!(data->flags & NFS_MOUNT_NONLM))
1905                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1906                                          NFS_MOUNT_LOCAL_FCNTL);
1907                 else
1908                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1909                                         NFS_MOUNT_LOCAL_FCNTL);
1910                 /*
1911                  * The legacy version 6 binary mount data from userspace has a
1912                  * field used only to transport selinux information into the
1913                  * the kernel.  To continue to support that functionality we
1914                  * have a touch of selinux knowledge here in the NFS code. The
1915                  * userspace code converted context=blah to just blah so we are
1916                  * converting back to the full string selinux understands.
1917                  */
1918                 if (data->context[0]){
1919 #ifdef CONFIG_SECURITY_SELINUX
1920                         int rc;
1921                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1922                         if (!opts_str)
1923                                 return -ENOMEM;
1924                         strcpy(opts_str, "context=");
1925                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1926                         strcat(opts_str, &data->context[0]);
1927                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1928                         kfree(opts_str);
1929                         if (rc)
1930                                 return rc;
1931 #else
1932                         return -EINVAL;
1933 #endif
1934                 }
1935
1936                 break;
1937         default: {
1938                 int status;
1939
1940                 if (nfs_parse_mount_options((char *)options, args) == 0)
1941                         return -EINVAL;
1942
1943                 if (!nfs_verify_server_address(sap))
1944                         goto out_no_address;
1945
1946                 if (args->version == 4)
1947 #ifdef CONFIG_NFS_V4
1948                         return nfs4_validate_text_mount_data(options,
1949                                                              args, dev_name);
1950 #else
1951                         goto out_v4_not_compiled;
1952 #endif
1953
1954                 nfs_set_port(sap, &args->nfs_server.port, 0);
1955
1956                 nfs_set_mount_transport_protocol(args);
1957
1958                 status = nfs_parse_devname(dev_name,
1959                                            &args->nfs_server.hostname,
1960                                            PAGE_SIZE,
1961                                            &args->nfs_server.export_path,
1962                                            NFS_MAXPATHLEN);
1963                 if (!status)
1964                         status = nfs_try_mount(args, mntfh);
1965
1966                 kfree(args->nfs_server.export_path);
1967                 args->nfs_server.export_path = NULL;
1968
1969                 if (status)
1970                         return status;
1971
1972                 break;
1973                 }
1974         }
1975
1976 #ifndef CONFIG_NFS_V3
1977         if (args->version == 3)
1978                 goto out_v3_not_compiled;
1979 #endif /* !CONFIG_NFS_V3 */
1980
1981         return 0;
1982
1983 out_no_data:
1984         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1985         return -EINVAL;
1986
1987 out_no_v3:
1988         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1989                  data->version);
1990         return -EINVAL;
1991
1992 out_no_sec:
1993         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1994         return -EINVAL;
1995
1996 #ifndef CONFIG_NFS_V3
1997 out_v3_not_compiled:
1998         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1999         return -EPROTONOSUPPORT;
2000 #endif /* !CONFIG_NFS_V3 */
2001
2002 #ifndef CONFIG_NFS_V4
2003 out_v4_not_compiled:
2004         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2005         return -EPROTONOSUPPORT;
2006 #endif /* !CONFIG_NFS_V4 */
2007
2008 out_nomem:
2009         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2010         return -ENOMEM;
2011
2012 out_no_address:
2013         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2014         return -EINVAL;
2015
2016 out_invalid_fh:
2017         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2018         return -EINVAL;
2019 }
2020
2021 static int
2022 nfs_compare_remount_data(struct nfs_server *nfss,
2023                          struct nfs_parsed_mount_data *data)
2024 {
2025         if (data->flags != nfss->flags ||
2026             data->rsize != nfss->rsize ||
2027             data->wsize != nfss->wsize ||
2028             data->retrans != nfss->client->cl_timeout->to_retries ||
2029             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2030             data->acregmin != nfss->acregmin / HZ ||
2031             data->acregmax != nfss->acregmax / HZ ||
2032             data->acdirmin != nfss->acdirmin / HZ ||
2033             data->acdirmax != nfss->acdirmax / HZ ||
2034             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2035             data->nfs_server.port != nfss->port ||
2036             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2037             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2038                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2039                 return -EINVAL;
2040
2041         return 0;
2042 }
2043
2044 static int
2045 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2046 {
2047         int error;
2048         struct nfs_server *nfss = sb->s_fs_info;
2049         struct nfs_parsed_mount_data *data;
2050         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2051         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2052         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2053
2054         /*
2055          * Userspace mount programs that send binary options generally send
2056          * them populated with default values. We have no way to know which
2057          * ones were explicitly specified. Fall back to legacy behavior and
2058          * just return success.
2059          */
2060         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2061             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2062                                            options->version <= 6))))
2063                 return 0;
2064
2065         data = kzalloc(sizeof(*data), GFP_KERNEL);
2066         if (data == NULL)
2067                 return -ENOMEM;
2068
2069         /* fill out struct with values from existing mount */
2070         data->flags = nfss->flags;
2071         data->rsize = nfss->rsize;
2072         data->wsize = nfss->wsize;
2073         data->retrans = nfss->client->cl_timeout->to_retries;
2074         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2075         data->acregmin = nfss->acregmin / HZ;
2076         data->acregmax = nfss->acregmax / HZ;
2077         data->acdirmin = nfss->acdirmin / HZ;
2078         data->acdirmax = nfss->acdirmax / HZ;
2079         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2080         data->nfs_server.port = nfss->port;
2081         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2082         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2083                 data->nfs_server.addrlen);
2084
2085         /* overwrite those values with any that were specified */
2086         error = nfs_parse_mount_options((char *)options, data);
2087         if (error < 0)
2088                 goto out;
2089
2090         /*
2091          * noac is a special case. It implies -o sync, but that's not
2092          * necessarily reflected in the mtab options. do_remount_sb
2093          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2094          * remount options, so we have to explicitly reset it.
2095          */
2096         if (data->flags & NFS_MOUNT_NOAC)
2097                 *flags |= MS_SYNCHRONOUS;
2098
2099         /* compare new mount options with old ones */
2100         error = nfs_compare_remount_data(nfss, data);
2101 out:
2102         kfree(data);
2103         return error;
2104 }
2105
2106 /*
2107  * Initialise the common bits of the superblock
2108  */
2109 static inline void nfs_initialise_sb(struct super_block *sb)
2110 {
2111         struct nfs_server *server = NFS_SB(sb);
2112
2113         sb->s_magic = NFS_SUPER_MAGIC;
2114
2115         /* We probably want something more informative here */
2116         snprintf(sb->s_id, sizeof(sb->s_id),
2117                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2118
2119         if (sb->s_blocksize == 0)
2120                 sb->s_blocksize = nfs_block_bits(server->wsize,
2121                                                  &sb->s_blocksize_bits);
2122
2123         sb->s_bdi = &server->backing_dev_info;
2124
2125         nfs_super_set_maxbytes(sb, server->maxfilesize);
2126 }
2127
2128 /*
2129  * Finish setting up an NFS2/3 superblock
2130  */
2131 static void nfs_fill_super(struct super_block *sb,
2132                            struct nfs_parsed_mount_data *data)
2133 {
2134         struct nfs_server *server = NFS_SB(sb);
2135
2136         sb->s_blocksize_bits = 0;
2137         sb->s_blocksize = 0;
2138         if (data->bsize)
2139                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2140
2141         if (server->nfs_client->rpc_ops->version == 3) {
2142                 /* The VFS shouldn't apply the umask to mode bits. We will do
2143                  * so ourselves when necessary.
2144                  */
2145                 sb->s_flags |= MS_POSIXACL;
2146                 sb->s_time_gran = 1;
2147         }
2148
2149         sb->s_op = &nfs_sops;
2150         nfs_initialise_sb(sb);
2151 }
2152
2153 /*
2154  * Finish setting up a cloned NFS2/3 superblock
2155  */
2156 static void nfs_clone_super(struct super_block *sb,
2157                             const struct super_block *old_sb)
2158 {
2159         struct nfs_server *server = NFS_SB(sb);
2160
2161         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2162         sb->s_blocksize = old_sb->s_blocksize;
2163         sb->s_maxbytes = old_sb->s_maxbytes;
2164
2165         if (server->nfs_client->rpc_ops->version == 3) {
2166                 /* The VFS shouldn't apply the umask to mode bits. We will do
2167                  * so ourselves when necessary.
2168                  */
2169                 sb->s_flags |= MS_POSIXACL;
2170                 sb->s_time_gran = 1;
2171         }
2172
2173         sb->s_op = old_sb->s_op;
2174         nfs_initialise_sb(sb);
2175 }
2176
2177 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2178 {
2179         const struct nfs_server *a = s->s_fs_info;
2180         const struct rpc_clnt *clnt_a = a->client;
2181         const struct rpc_clnt *clnt_b = b->client;
2182
2183         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2184                 goto Ebusy;
2185         if (a->nfs_client != b->nfs_client)
2186                 goto Ebusy;
2187         if (a->flags != b->flags)
2188                 goto Ebusy;
2189         if (a->wsize != b->wsize)
2190                 goto Ebusy;
2191         if (a->rsize != b->rsize)
2192                 goto Ebusy;
2193         if (a->acregmin != b->acregmin)
2194                 goto Ebusy;
2195         if (a->acregmax != b->acregmax)
2196                 goto Ebusy;
2197         if (a->acdirmin != b->acdirmin)
2198                 goto Ebusy;
2199         if (a->acdirmax != b->acdirmax)
2200                 goto Ebusy;
2201         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2202                 goto Ebusy;
2203         return 1;
2204 Ebusy:
2205         return 0;
2206 }
2207
2208 struct nfs_sb_mountdata {
2209         struct nfs_server *server;
2210         int mntflags;
2211 };
2212
2213 static int nfs_set_super(struct super_block *s, void *data)
2214 {
2215         struct nfs_sb_mountdata *sb_mntdata = data;
2216         struct nfs_server *server = sb_mntdata->server;
2217         int ret;
2218
2219         s->s_flags = sb_mntdata->mntflags;
2220         s->s_fs_info = server;
2221         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2222         ret = set_anon_super(s, server);
2223         if (ret == 0)
2224                 server->s_dev = s->s_dev;
2225         return ret;
2226 }
2227
2228 static int nfs_compare_super_address(struct nfs_server *server1,
2229                                      struct nfs_server *server2)
2230 {
2231         struct sockaddr *sap1, *sap2;
2232
2233         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2234         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2235
2236         if (sap1->sa_family != sap2->sa_family)
2237                 return 0;
2238
2239         switch (sap1->sa_family) {
2240         case AF_INET: {
2241                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2242                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2243                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2244                         return 0;
2245                 if (sin1->sin_port != sin2->sin_port)
2246                         return 0;
2247                 break;
2248         }
2249         case AF_INET6: {
2250                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2251                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2252                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2253                         return 0;
2254                 if (sin1->sin6_port != sin2->sin6_port)
2255                         return 0;
2256                 break;
2257         }
2258         default:
2259                 return 0;
2260         }
2261
2262         return 1;
2263 }
2264
2265 static int nfs_compare_super(struct super_block *sb, void *data)
2266 {
2267         struct nfs_sb_mountdata *sb_mntdata = data;
2268         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2269         int mntflags = sb_mntdata->mntflags;
2270
2271         if (!nfs_compare_super_address(old, server))
2272                 return 0;
2273         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2274         if (old->flags & NFS_MOUNT_UNSHARED)
2275                 return 0;
2276         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2277                 return 0;
2278         return nfs_compare_mount_options(sb, server, mntflags);
2279 }
2280
2281 static int nfs_bdi_register(struct nfs_server *server)
2282 {
2283         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2284 }
2285
2286 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2287         int flags, const char *dev_name, void *raw_data)
2288 {
2289         struct nfs_server *server = NULL;
2290         struct super_block *s;
2291         struct nfs_parsed_mount_data *data;
2292         struct nfs_fh *mntfh;
2293         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2294         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2295         struct nfs_sb_mountdata sb_mntdata = {
2296                 .mntflags = flags,
2297         };
2298         int error;
2299
2300         data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2301         mntfh = nfs_alloc_fhandle();
2302         if (data == NULL || mntfh == NULL)
2303                 goto out;
2304
2305         /* Validate the mount data */
2306         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2307         if (error < 0) {
2308                 mntroot = ERR_PTR(error);
2309                 goto out;
2310         }
2311
2312 #ifdef CONFIG_NFS_V4
2313         if (data->version == 4) {
2314                 mntroot = nfs4_try_mount(flags, dev_name, data);
2315                 goto out;
2316         }
2317 #endif  /* CONFIG_NFS_V4 */
2318
2319         /* Get a volume representation */
2320         server = nfs_create_server(data, mntfh);
2321         if (IS_ERR(server)) {
2322                 mntroot = ERR_CAST(server);
2323                 goto out;
2324         }
2325         sb_mntdata.server = server;
2326
2327         if (server->flags & NFS_MOUNT_UNSHARED)
2328                 compare_super = NULL;
2329
2330         /* -o noac implies -o sync */
2331         if (server->flags & NFS_MOUNT_NOAC)
2332                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2333
2334         /* Get a superblock - note that we may end up sharing one that already exists */
2335         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2336         if (IS_ERR(s)) {
2337                 mntroot = ERR_CAST(s);
2338                 goto out_err_nosb;
2339         }
2340
2341         if (s->s_fs_info != server) {
2342                 nfs_free_server(server);
2343                 server = NULL;
2344         } else {
2345                 error = nfs_bdi_register(server);
2346                 if (error) {
2347                         mntroot = ERR_PTR(error);
2348                         goto error_splat_bdi;
2349                 }
2350         }
2351
2352         if (!s->s_root) {
2353                 /* initial superblock/root creation */
2354                 nfs_fill_super(s, data);
2355                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2356         }
2357
2358         mntroot = nfs_get_root(s, mntfh, dev_name);
2359         if (IS_ERR(mntroot))
2360                 goto error_splat_super;
2361
2362         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2363         if (error)
2364                 goto error_splat_root;
2365
2366         s->s_flags |= MS_ACTIVE;
2367
2368 out:
2369         nfs_free_parsed_mount_data(data);
2370         nfs_free_fhandle(mntfh);
2371         return mntroot;
2372
2373 out_err_nosb:
2374         nfs_free_server(server);
2375         goto out;
2376
2377 error_splat_root:
2378         dput(mntroot);
2379         mntroot = ERR_PTR(error);
2380 error_splat_super:
2381         if (server && !s->s_root)
2382                 bdi_unregister(&server->backing_dev_info);
2383 error_splat_bdi:
2384         deactivate_locked_super(s);
2385         goto out;
2386 }
2387
2388 /*
2389  * Ensure that we unregister the bdi before kill_anon_super
2390  * releases the device name
2391  */
2392 static void nfs_put_super(struct super_block *s)
2393 {
2394         struct nfs_server *server = NFS_SB(s);
2395
2396         bdi_unregister(&server->backing_dev_info);
2397 }
2398
2399 /*
2400  * Destroy an NFS2/3 superblock
2401  */
2402 static void nfs_kill_super(struct super_block *s)
2403 {
2404         struct nfs_server *server = NFS_SB(s);
2405
2406         kill_anon_super(s);
2407         nfs_fscache_release_super_cookie(s);
2408         nfs_free_server(server);
2409 }
2410
2411 /*
2412  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2413  */
2414 static struct dentry *
2415 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2416                 const char *dev_name, void *raw_data)
2417 {
2418         struct nfs_clone_mount *data = raw_data;
2419         struct super_block *s;
2420         struct nfs_server *server;
2421         struct dentry *mntroot;
2422         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2423         struct nfs_sb_mountdata sb_mntdata = {
2424                 .mntflags = flags,
2425         };
2426         int error;
2427
2428         dprintk("--> nfs_xdev_mount()\n");
2429
2430         /* create a new volume representation */
2431         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2432         if (IS_ERR(server)) {
2433                 error = PTR_ERR(server);
2434                 goto out_err_noserver;
2435         }
2436         sb_mntdata.server = server;
2437
2438         if (server->flags & NFS_MOUNT_UNSHARED)
2439                 compare_super = NULL;
2440
2441         /* -o noac implies -o sync */
2442         if (server->flags & NFS_MOUNT_NOAC)
2443                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2444
2445         /* Get a superblock - note that we may end up sharing one that already exists */
2446         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2447         if (IS_ERR(s)) {
2448                 error = PTR_ERR(s);
2449                 goto out_err_nosb;
2450         }
2451
2452         if (s->s_fs_info != server) {
2453                 nfs_free_server(server);
2454                 server = NULL;
2455         } else {
2456                 error = nfs_bdi_register(server);
2457                 if (error)
2458                         goto error_splat_bdi;
2459         }
2460
2461         if (!s->s_root) {
2462                 /* initial superblock/root creation */
2463                 nfs_clone_super(s, data->sb);
2464                 nfs_fscache_get_super_cookie(s, NULL, data);
2465         }
2466
2467         mntroot = nfs_get_root(s, data->fh, dev_name);
2468         if (IS_ERR(mntroot)) {
2469                 error = PTR_ERR(mntroot);
2470                 goto error_splat_super;
2471         }
2472         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2473                 dput(mntroot);
2474                 error = -ESTALE;
2475                 goto error_splat_super;
2476         }
2477
2478         s->s_flags |= MS_ACTIVE;
2479
2480         /* clone any lsm security options from the parent to the new sb */
2481         security_sb_clone_mnt_opts(data->sb, s);
2482
2483         dprintk("<-- nfs_xdev_mount() = 0\n");
2484         return mntroot;
2485
2486 out_err_nosb:
2487         nfs_free_server(server);
2488 out_err_noserver:
2489         dprintk("<-- nfs_xdev_mount() = %d [error]\n", error);
2490         return ERR_PTR(error);
2491
2492 error_splat_super:
2493         if (server && !s->s_root)
2494                 bdi_unregister(&server->backing_dev_info);
2495 error_splat_bdi:
2496         deactivate_locked_super(s);
2497         dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error);
2498         return ERR_PTR(error);
2499 }
2500
2501 #ifdef CONFIG_NFS_V4
2502
2503 /*
2504  * Finish setting up a cloned NFS4 superblock
2505  */
2506 static void nfs4_clone_super(struct super_block *sb,
2507                             const struct super_block *old_sb)
2508 {
2509         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2510         sb->s_blocksize = old_sb->s_blocksize;
2511         sb->s_maxbytes = old_sb->s_maxbytes;
2512         sb->s_time_gran = 1;
2513         sb->s_op = old_sb->s_op;
2514         /*
2515          * The VFS shouldn't apply the umask to mode bits. We will do
2516          * so ourselves when necessary.
2517          */
2518         sb->s_flags  |= MS_POSIXACL;
2519         sb->s_xattr  = old_sb->s_xattr;
2520         nfs_initialise_sb(sb);
2521 }
2522
2523 /*
2524  * Set up an NFS4 superblock
2525  */
2526 static void nfs4_fill_super(struct super_block *sb)
2527 {
2528         sb->s_time_gran = 1;
2529         sb->s_op = &nfs4_sops;
2530         /*
2531          * The VFS shouldn't apply the umask to mode bits. We will do
2532          * so ourselves when necessary.
2533          */
2534         sb->s_flags  |= MS_POSIXACL;
2535         sb->s_xattr = nfs4_xattr_handlers;
2536         nfs_initialise_sb(sb);
2537 }
2538
2539 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2540 {
2541         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2542                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2543 }
2544
2545 static int nfs4_validate_text_mount_data(void *options,
2546                                          struct nfs_parsed_mount_data *args,
2547                                          const char *dev_name)
2548 {
2549         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2550
2551         nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2552
2553         nfs_validate_transport_protocol(args);
2554
2555         nfs4_validate_mount_flags(args);
2556
2557         if (args->version != 4) {
2558                 dfprintk(MOUNT,
2559                          "NFS4: Illegal mount version\n");
2560                 return -EINVAL;
2561         }
2562
2563         if (args->auth_flavor_len > 1) {
2564                 dfprintk(MOUNT,
2565                          "NFS4: Too many RPC auth flavours specified\n");
2566                 return -EINVAL;
2567         }
2568
2569         return nfs_parse_devname(dev_name,
2570                                    &args->nfs_server.hostname,
2571                                    NFS4_MAXNAMLEN,
2572                                    &args->nfs_server.export_path,
2573                                    NFS4_MAXPATHLEN);
2574 }
2575
2576 /*
2577  * Validate NFSv4 mount options
2578  */
2579 static int nfs4_validate_mount_data(void *options,
2580                                     struct nfs_parsed_mount_data *args,
2581                                     const char *dev_name)
2582 {
2583         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2584         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2585         char *c;
2586
2587         if (data == NULL)
2588                 goto out_no_data;
2589
2590         switch (data->version) {
2591         case 1:
2592                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2593                         goto out_no_address;
2594                 if (data->host_addrlen == 0)
2595                         goto out_no_address;
2596                 args->nfs_server.addrlen = data->host_addrlen;
2597                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2598                         return -EFAULT;
2599                 if (!nfs_verify_server_address(sap))
2600                         goto out_no_address;
2601
2602                 if (data->auth_flavourlen) {
2603                         if (data->auth_flavourlen > 1)
2604                                 goto out_inval_auth;
2605                         if (copy_from_user(&args->auth_flavors[0],
2606                                            data->auth_flavours,
2607                                            sizeof(args->auth_flavors[0])))
2608                                 return -EFAULT;
2609                 }
2610
2611                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2612                 if (IS_ERR(c))
2613                         return PTR_ERR(c);
2614                 args->nfs_server.hostname = c;
2615
2616                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2617                 if (IS_ERR(c))
2618                         return PTR_ERR(c);
2619                 args->nfs_server.export_path = c;
2620                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2621
2622                 c = strndup_user(data->client_addr.data, 16);
2623                 if (IS_ERR(c))
2624                         return PTR_ERR(c);
2625                 args->client_address = c;
2626
2627                 /*
2628                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2629                  * can deal with.
2630                  */
2631
2632                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2633                 args->rsize     = data->rsize;
2634                 args->wsize     = data->wsize;
2635                 args->timeo     = data->timeo;
2636                 args->retrans   = data->retrans;
2637                 args->acregmin  = data->acregmin;
2638                 args->acregmax  = data->acregmax;
2639                 args->acdirmin  = data->acdirmin;
2640                 args->acdirmax  = data->acdirmax;
2641                 args->nfs_server.protocol = data->proto;
2642                 nfs_validate_transport_protocol(args);
2643
2644                 break;
2645         default:
2646                 if (nfs_parse_mount_options((char *)options, args) == 0)
2647                         return -EINVAL;
2648
2649                 if (!nfs_verify_server_address(sap))
2650                         return -EINVAL;
2651
2652                 return nfs4_validate_text_mount_data(options, args, dev_name);
2653         }
2654
2655         return 0;
2656
2657 out_no_data:
2658         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2659         return -EINVAL;
2660
2661 out_inval_auth:
2662         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2663                  data->auth_flavourlen);
2664         return -EINVAL;
2665
2666 out_no_address:
2667         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2668         return -EINVAL;
2669 }
2670
2671 /*
2672  * Get the superblock for the NFS4 root partition
2673  */
2674 static struct dentry *
2675 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2676                   const char *dev_name, void *raw_data)
2677 {
2678         struct nfs_parsed_mount_data *data = raw_data;
2679         struct super_block *s;
2680         struct nfs_server *server;
2681         struct nfs_fh *mntfh;
2682         struct dentry *mntroot;
2683         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2684         struct nfs_sb_mountdata sb_mntdata = {
2685                 .mntflags = flags,
2686         };
2687         int error = -ENOMEM;
2688
2689         mntfh = nfs_alloc_fhandle();
2690         if (data == NULL || mntfh == NULL)
2691                 goto out;
2692
2693         /* Get a volume representation */
2694         server = nfs4_create_server(data, mntfh);
2695         if (IS_ERR(server)) {
2696                 error = PTR_ERR(server);
2697                 goto out;
2698         }
2699         sb_mntdata.server = server;
2700
2701         if (server->flags & NFS4_MOUNT_UNSHARED)
2702                 compare_super = NULL;
2703
2704         /* -o noac implies -o sync */
2705         if (server->flags & NFS_MOUNT_NOAC)
2706                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2707
2708         /* Get a superblock - note that we may end up sharing one that already exists */
2709         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2710         if (IS_ERR(s)) {
2711                 error = PTR_ERR(s);
2712                 goto out_free;
2713         }
2714
2715         if (s->s_fs_info != server) {
2716                 nfs_free_server(server);
2717                 server = NULL;
2718         } else {
2719                 error = nfs_bdi_register(server);
2720                 if (error)
2721                         goto error_splat_bdi;
2722         }
2723
2724         if (!s->s_root) {
2725                 /* initial superblock/root creation */
2726                 nfs4_fill_super(s);
2727                 nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2728         }
2729
2730         mntroot = nfs4_get_root(s, mntfh, dev_name);
2731         if (IS_ERR(mntroot)) {
2732                 error = PTR_ERR(mntroot);
2733                 goto error_splat_super;
2734         }
2735
2736         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2737         if (error)
2738                 goto error_splat_root;
2739
2740         s->s_flags |= MS_ACTIVE;
2741
2742         nfs_free_fhandle(mntfh);
2743         return mntroot;
2744
2745 out:
2746         nfs_free_fhandle(mntfh);
2747         return ERR_PTR(error);
2748
2749 out_free:
2750         nfs_free_server(server);
2751         goto out;
2752
2753 error_splat_root:
2754         dput(mntroot);
2755 error_splat_super:
2756         if (server && !s->s_root)
2757                 bdi_unregister(&server->backing_dev_info);
2758 error_splat_bdi:
2759         deactivate_locked_super(s);
2760         goto out;
2761 }
2762
2763 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2764                 int flags, void *data, const char *hostname)
2765 {
2766         struct vfsmount *root_mnt;
2767         char *root_devname;
2768         size_t len;
2769
2770         len = strlen(hostname) + 5;
2771         root_devname = kmalloc(len, GFP_KERNEL);
2772         if (root_devname == NULL)
2773                 return ERR_PTR(-ENOMEM);
2774         /* Does hostname needs to be enclosed in brackets? */
2775         if (strchr(hostname, ':'))
2776                 snprintf(root_devname, len, "[%s]:/", hostname);
2777         else
2778                 snprintf(root_devname, len, "%s:/", hostname);
2779         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2780         kfree(root_devname);
2781         return root_mnt;
2782 }
2783
2784 struct nfs_referral_count {
2785         struct list_head list;
2786         const struct task_struct *task;
2787         unsigned int referral_count;
2788 };
2789
2790 static LIST_HEAD(nfs_referral_count_list);
2791 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2792
2793 static struct nfs_referral_count *nfs_find_referral_count(void)
2794 {
2795         struct nfs_referral_count *p;
2796
2797         list_for_each_entry(p, &nfs_referral_count_list, list) {
2798                 if (p->task == current)
2799                         return p;
2800         }
2801         return NULL;
2802 }
2803
2804 #define NFS_MAX_NESTED_REFERRALS 2
2805
2806 static int nfs_referral_loop_protect(void)
2807 {
2808         struct nfs_referral_count *p, *new;
2809         int ret = -ENOMEM;
2810
2811         new = kmalloc(sizeof(*new), GFP_KERNEL);
2812         if (!new)
2813                 goto out;
2814         new->task = current;
2815         new->referral_count = 1;
2816
2817         ret = 0;
2818         spin_lock(&nfs_referral_count_list_lock);
2819         p = nfs_find_referral_count();
2820         if (p != NULL) {
2821                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2822                         ret = -ELOOP;
2823                 else
2824                         p->referral_count++;
2825         } else {
2826                 list_add(&new->list, &nfs_referral_count_list);
2827                 new = NULL;
2828         }
2829         spin_unlock(&nfs_referral_count_list_lock);
2830         kfree(new);
2831 out:
2832         return ret;
2833 }
2834
2835 static void nfs_referral_loop_unprotect(void)
2836 {
2837         struct nfs_referral_count *p;
2838
2839         spin_lock(&nfs_referral_count_list_lock);
2840         p = nfs_find_referral_count();
2841         p->referral_count--;
2842         if (p->referral_count == 0)
2843                 list_del(&p->list);
2844         else
2845                 p = NULL;
2846         spin_unlock(&nfs_referral_count_list_lock);
2847         kfree(p);
2848 }
2849
2850 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2851                 const char *export_path)
2852 {
2853         struct dentry *dentry;
2854         int err;
2855
2856         if (IS_ERR(root_mnt))
2857                 return ERR_CAST(root_mnt);
2858
2859         err = nfs_referral_loop_protect();
2860         if (err) {
2861                 mntput(root_mnt);
2862                 return ERR_PTR(err);
2863         }
2864
2865         dentry = mount_subtree(root_mnt, export_path);
2866         nfs_referral_loop_unprotect();
2867
2868         return dentry;
2869 }
2870
2871 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2872                          struct nfs_parsed_mount_data *data)
2873 {
2874         char *export_path;
2875         struct vfsmount *root_mnt;
2876         struct dentry *res;
2877
2878         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2879
2880         export_path = data->nfs_server.export_path;
2881         data->nfs_server.export_path = "/";
2882         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2883                         data->nfs_server.hostname);
2884         data->nfs_server.export_path = export_path;
2885
2886         res = nfs_follow_remote_path(root_mnt, export_path);
2887
2888         dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2889                         IS_ERR(res) ? PTR_ERR(res) : 0,
2890                         IS_ERR(res) ? " [error]" : "");
2891         return res;
2892 }
2893
2894 /*
2895  * Get the superblock for an NFS4 mountpoint
2896  */
2897 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2898         int flags, const char *dev_name, void *raw_data)
2899 {
2900         struct nfs_parsed_mount_data *data;
2901         int error = -ENOMEM;
2902         struct dentry *res = ERR_PTR(-ENOMEM);
2903
2904         data = nfs_alloc_parsed_mount_data(4);
2905         if (data == NULL)
2906                 goto out;
2907
2908         /* Validate the mount data */
2909         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2910         if (error < 0) {
2911                 res = ERR_PTR(error);
2912                 goto out;
2913         }
2914
2915         res = nfs4_try_mount(flags, dev_name, data);
2916         if (IS_ERR(res))
2917                 error = PTR_ERR(res);
2918
2919 out:
2920         nfs_free_parsed_mount_data(data);
2921         dprintk("<-- nfs4_mount() = %d%s\n", error,
2922                         error != 0 ? " [error]" : "");
2923         return res;
2924 }
2925
2926 static void nfs4_kill_super(struct super_block *sb)
2927 {
2928         struct nfs_server *server = NFS_SB(sb);
2929
2930         dprintk("--> %s\n", __func__);
2931         nfs_super_return_all_delegations(sb);
2932         kill_anon_super(sb);
2933         nfs_fscache_release_super_cookie(sb);
2934         nfs_free_server(server);
2935         dprintk("<-- %s\n", __func__);
2936 }
2937
2938 /*
2939  * Clone an NFS4 server record on xdev traversal (FSID-change)
2940  */
2941 static struct dentry *
2942 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2943                  const char *dev_name, void *raw_data)
2944 {
2945         struct nfs_clone_mount *data = raw_data;
2946         struct super_block *s;
2947         struct nfs_server *server;
2948         struct dentry *mntroot;
2949         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2950         struct nfs_sb_mountdata sb_mntdata = {
2951                 .mntflags = flags,
2952         };
2953         int error;
2954
2955         dprintk("--> nfs4_xdev_mount()\n");
2956
2957         /* create a new volume representation */
2958         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2959         if (IS_ERR(server)) {
2960                 error = PTR_ERR(server);
2961                 goto out_err_noserver;
2962         }
2963         sb_mntdata.server = server;
2964
2965         if (server->flags & NFS4_MOUNT_UNSHARED)
2966                 compare_super = NULL;
2967
2968         /* -o noac implies -o sync */
2969         if (server->flags & NFS_MOUNT_NOAC)
2970                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2971
2972         /* Get a superblock - note that we may end up sharing one that already exists */
2973         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2974         if (IS_ERR(s)) {
2975                 error = PTR_ERR(s);
2976                 goto out_err_nosb;
2977         }
2978
2979         if (s->s_fs_info != server) {
2980                 nfs_free_server(server);
2981                 server = NULL;
2982         } else {
2983                 error = nfs_bdi_register(server);
2984                 if (error)
2985                         goto error_splat_bdi;
2986         }
2987
2988         if (!s->s_root) {
2989                 /* initial superblock/root creation */
2990                 nfs4_clone_super(s, data->sb);
2991                 nfs_fscache_get_super_cookie(s, NULL, data);
2992         }
2993
2994         mntroot = nfs4_get_root(s, data->fh, dev_name);
2995         if (IS_ERR(mntroot)) {
2996                 error = PTR_ERR(mntroot);
2997                 goto error_splat_super;
2998         }
2999         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3000                 dput(mntroot);
3001                 error = -ESTALE;
3002                 goto error_splat_super;
3003         }
3004
3005         s->s_flags |= MS_ACTIVE;
3006
3007         security_sb_clone_mnt_opts(data->sb, s);
3008
3009         dprintk("<-- nfs4_xdev_mount() = 0\n");
3010         return mntroot;
3011
3012 out_err_nosb:
3013         nfs_free_server(server);
3014 out_err_noserver:
3015         dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error);
3016         return ERR_PTR(error);
3017
3018 error_splat_super:
3019         if (server && !s->s_root)
3020                 bdi_unregister(&server->backing_dev_info);
3021 error_splat_bdi:
3022         deactivate_locked_super(s);
3023         dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error);
3024         return ERR_PTR(error);
3025 }
3026
3027 static struct dentry *
3028 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
3029                            const char *dev_name, void *raw_data)
3030 {
3031         struct nfs_clone_mount *data = raw_data;
3032         struct super_block *s;
3033         struct nfs_server *server;
3034         struct dentry *mntroot;
3035         struct nfs_fh *mntfh;
3036         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
3037         struct nfs_sb_mountdata sb_mntdata = {
3038                 .mntflags = flags,
3039         };
3040         int error = -ENOMEM;
3041
3042         dprintk("--> nfs4_referral_get_sb()\n");
3043
3044         mntfh = nfs_alloc_fhandle();
3045         if (mntfh == NULL)
3046                 goto out_err_nofh;
3047
3048         /* create a new volume representation */
3049         server = nfs4_create_referral_server(data, mntfh);
3050         if (IS_ERR(server)) {
3051                 error = PTR_ERR(server);
3052                 goto out_err_noserver;
3053         }
3054         sb_mntdata.server = server;
3055
3056         if (server->flags & NFS4_MOUNT_UNSHARED)
3057                 compare_super = NULL;
3058
3059         /* -o noac implies -o sync */
3060         if (server->flags & NFS_MOUNT_NOAC)
3061                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
3062
3063         /* Get a superblock - note that we may end up sharing one that already exists */
3064         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3065         if (IS_ERR(s)) {
3066                 error = PTR_ERR(s);
3067                 goto out_err_nosb;
3068         }
3069
3070         if (s->s_fs_info != server) {
3071                 nfs_free_server(server);
3072                 server = NULL;
3073         } else {
3074                 error = nfs_bdi_register(server);
3075                 if (error)
3076                         goto error_splat_bdi;
3077         }
3078
3079         if (!s->s_root) {
3080                 /* initial superblock/root creation */
3081                 nfs4_fill_super(s);
3082                 nfs_fscache_get_super_cookie(s, NULL, data);
3083         }
3084
3085         mntroot = nfs4_get_root(s, mntfh, dev_name);
3086         if (IS_ERR(mntroot)) {
3087                 error = PTR_ERR(mntroot);
3088                 goto error_splat_super;
3089         }
3090         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3091                 dput(mntroot);
3092                 error = -ESTALE;
3093                 goto error_splat_super;
3094         }
3095
3096         s->s_flags |= MS_ACTIVE;
3097
3098         security_sb_clone_mnt_opts(data->sb, s);
3099
3100         nfs_free_fhandle(mntfh);
3101         dprintk("<-- nfs4_referral_get_sb() = 0\n");
3102         return mntroot;
3103
3104 out_err_nosb:
3105         nfs_free_server(server);
3106 out_err_noserver:
3107         nfs_free_fhandle(mntfh);
3108 out_err_nofh:
3109         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3110         return ERR_PTR(error);
3111
3112 error_splat_super:
3113         if (server && !s->s_root)
3114                 bdi_unregister(&server->backing_dev_info);
3115 error_splat_bdi:
3116         deactivate_locked_super(s);
3117         nfs_free_fhandle(mntfh);
3118         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3119         return ERR_PTR(error);
3120 }
3121
3122 /*
3123  * Create an NFS4 server record on referral traversal
3124  */
3125 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3126                 int flags, const char *dev_name, void *raw_data)
3127 {
3128         struct nfs_clone_mount *data = raw_data;
3129         char *export_path;
3130         struct vfsmount *root_mnt;
3131         struct dentry *res;
3132
3133         dprintk("--> nfs4_referral_mount()\n");
3134
3135         export_path = data->mnt_path;
3136         data->mnt_path = "/";
3137
3138         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3139                         flags, data, data->hostname);
3140         data->mnt_path = export_path;
3141
3142         res = nfs_follow_remote_path(root_mnt, export_path);
3143         dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3144                         IS_ERR(res) ? PTR_ERR(res) : 0,
3145                         IS_ERR(res) ? " [error]" : "");
3146         return res;
3147 }
3148
3149 #endif /* CONFIG_NFS_V4 */