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 #define NFS_TEXT_DATA           1
  70
  71 #ifdef CONFIG_NFS_V3
  72 #define NFS_DEFAULT_VERSION 3
  73 #else
  74 #define NFS_DEFAULT_VERSION 2
  75 #endif
  76
  77 enum {
  78         /* Mount options that take no arguments */
  79         Opt_soft, Opt_hard,
  80         Opt_posix, Opt_noposix,
  81         Opt_cto, Opt_nocto,
  82         Opt_ac, Opt_noac,
  83         Opt_lock, Opt_nolock,
  84         Opt_udp, Opt_tcp, Opt_rdma,
  85         Opt_acl, Opt_noacl,
  86         Opt_rdirplus, Opt_nordirplus,
  87         Opt_sharecache, Opt_nosharecache,
  88         Opt_resvport, Opt_noresvport,
  89         Opt_fscache, Opt_nofscache,
  90
  91         /* Mount options that take integer arguments */
  92         Opt_port,
  93         Opt_rsize, Opt_wsize, Opt_bsize,
  94         Opt_timeo, Opt_retrans,
  95         Opt_acregmin, Opt_acregmax,
  96         Opt_acdirmin, Opt_acdirmax,
  97         Opt_actimeo,
  98         Opt_namelen,
  99         Opt_mountport,
 100         Opt_mountvers,
 101         Opt_minorversion,
 102
 103         /* Mount options that take string arguments */
 104         Opt_nfsvers,
 105         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
 106         Opt_addr, Opt_mountaddr, Opt_clientaddr,
 107         Opt_lookupcache,
 108         Opt_fscache_uniq,
 109         Opt_local_lock,
 110
 111         /* Special mount options */
 112         Opt_userspace, Opt_deprecated, Opt_sloppy,
 113
 114         Opt_err
 115 };
 116
 117 static const match_table_t nfs_mount_option_tokens = {
 118         { Opt_userspace, "bg" },
 119         { Opt_userspace, "fg" },
 120         { Opt_userspace, "retry=%s" },
 121
 122         { Opt_sloppy, "sloppy" },
 123
 124         { Opt_soft, "soft" },
 125         { Opt_hard, "hard" },
 126         { Opt_deprecated, "intr" },
 127         { Opt_deprecated, "nointr" },
 128         { Opt_posix, "posix" },
 129         { Opt_noposix, "noposix" },
 130         { Opt_cto, "cto" },
 131         { Opt_nocto, "nocto" },
 132         { Opt_ac, "ac" },
 133         { Opt_noac, "noac" },
 134         { Opt_lock, "lock" },
 135         { Opt_nolock, "nolock" },
 136         { Opt_udp, "udp" },
 137         { Opt_tcp, "tcp" },
 138         { Opt_rdma, "rdma" },
 139         { Opt_acl, "acl" },
 140         { Opt_noacl, "noacl" },
 141         { Opt_rdirplus, "rdirplus" },
 142         { Opt_nordirplus, "nordirplus" },
 143         { Opt_sharecache, "sharecache" },
 144         { Opt_nosharecache, "nosharecache" },
 145         { Opt_resvport, "resvport" },
 146         { Opt_noresvport, "noresvport" },
 147         { Opt_fscache, "fsc" },
 148         { Opt_nofscache, "nofsc" },
 149
 150         { Opt_port, "port=%s" },
 151         { Opt_rsize, "rsize=%s" },
 152         { Opt_wsize, "wsize=%s" },
 153         { Opt_bsize, "bsize=%s" },
 154         { Opt_timeo, "timeo=%s" },
 155         { Opt_retrans, "retrans=%s" },
 156         { Opt_acregmin, "acregmin=%s" },
 157         { Opt_acregmax, "acregmax=%s" },
 158         { Opt_acdirmin, "acdirmin=%s" },
 159         { Opt_acdirmax, "acdirmax=%s" },
 160         { Opt_actimeo, "actimeo=%s" },
 161         { Opt_namelen, "namlen=%s" },
 162         { Opt_mountport, "mountport=%s" },
 163         { Opt_mountvers, "mountvers=%s" },
 164         { Opt_minorversion, "minorversion=%s" },
 165
 166         { Opt_nfsvers, "nfsvers=%s" },
 167         { Opt_nfsvers, "vers=%s" },
 168
 169         { Opt_sec, "sec=%s" },
 170         { Opt_proto, "proto=%s" },
 171         { Opt_mountproto, "mountproto=%s" },
 172         { Opt_addr, "addr=%s" },
 173         { Opt_clientaddr, "clientaddr=%s" },
 174         { Opt_mounthost, "mounthost=%s" },
 175         { Opt_mountaddr, "mountaddr=%s" },
 176
 177         { Opt_lookupcache, "lookupcache=%s" },
 178         { Opt_fscache_uniq, "fsc=%s" },
 179         { Opt_local_lock, "local_lock=%s" },
 180
 181         /* The following needs to be listed after all other options */
 182         { Opt_nfsvers, "v%s" },
 183
 184         { Opt_err, NULL }
 185 };
 186
 187 enum {
 188         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
 189
 190         Opt_xprt_err
 191 };
 192
 193 static const match_table_t nfs_xprt_protocol_tokens = {
 194         { Opt_xprt_udp, "udp" },
 195         { Opt_xprt_udp6, "udp6" },
 196         { Opt_xprt_tcp, "tcp" },
 197         { Opt_xprt_tcp6, "tcp6" },
 198         { Opt_xprt_rdma, "rdma" },
 199
 200         { Opt_xprt_err, NULL }
 201 };
 202
 203 enum {
 204         Opt_sec_none, Opt_sec_sys,
 205         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
 206         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
 207         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
 208
 209         Opt_sec_err
 210 };
 211
 212 static const match_table_t nfs_secflavor_tokens = {
 213         { Opt_sec_none, "none" },
 214         { Opt_sec_none, "null" },
 215         { Opt_sec_sys, "sys" },
 216
 217         { Opt_sec_krb5, "krb5" },
 218         { Opt_sec_krb5i, "krb5i" },
 219         { Opt_sec_krb5p, "krb5p" },
 220
 221         { Opt_sec_lkey, "lkey" },
 222         { Opt_sec_lkeyi, "lkeyi" },
 223         { Opt_sec_lkeyp, "lkeyp" },
 224
 225         { Opt_sec_spkm, "spkm3" },
 226         { Opt_sec_spkmi, "spkm3i" },
 227         { Opt_sec_spkmp, "spkm3p" },
 228
 229         { Opt_sec_err, NULL }
 230 };
 231
 232 enum {
 233         Opt_lookupcache_all, Opt_lookupcache_positive,
 234         Opt_lookupcache_none,
 235
 236         Opt_lookupcache_err
 237 };
 238
 239 static match_table_t nfs_lookupcache_tokens = {
 240         { Opt_lookupcache_all, "all" },
 241         { Opt_lookupcache_positive, "pos" },
 242         { Opt_lookupcache_positive, "positive" },
 243         { Opt_lookupcache_none, "none" },
 244
 245         { Opt_lookupcache_err, NULL }
 246 };
 247
 248 enum {
 249         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
 250         Opt_local_lock_none,
 251
 252         Opt_local_lock_err
 253 };
 254
 255 static match_table_t nfs_local_lock_tokens = {
 256         { Opt_local_lock_all, "all" },
 257         { Opt_local_lock_flock, "flock" },
 258         { Opt_local_lock_posix, "posix" },
 259         { Opt_local_lock_none, "none" },
 260
 261         { Opt_local_lock_err, NULL }
 262 };
 263
 264 enum {
 265         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
 266         Opt_vers_4_1,
 267
 268         Opt_vers_err
 269 };
 270
 271 static match_table_t nfs_vers_tokens = {
 272         { Opt_vers_2, "2" },
 273         { Opt_vers_3, "3" },
 274         { Opt_vers_4, "4" },
 275         { Opt_vers_4_0, "4.0" },
 276         { Opt_vers_4_1, "4.1" },
 277
 278         { Opt_vers_err, NULL }
 279 };
 280
 281 struct nfs_mount_info {
 282         void (*fill_super)(struct super_block *, struct nfs_mount_info *);
 283         int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
 284         struct nfs_parsed_mount_data *parsed;
 285         struct nfs_clone_mount *cloned;
 286         struct nfs_fh *mntfh;
 287 };
 288
 289 static void nfs_umount_begin(struct super_block *);
 290 static int  nfs_statfs(struct dentry *, struct kstatfs *);
 291 static int  nfs_show_options(struct seq_file *, struct dentry *);
 292 static int  nfs_show_devname(struct seq_file *, struct dentry *);
 293 static int  nfs_show_path(struct seq_file *, struct dentry *);
 294 static int  nfs_show_stats(struct seq_file *, struct dentry *);
 295 static struct dentry *nfs_fs_mount_common(struct file_system_type *,
 296                 struct nfs_server *, int, const char *, struct nfs_mount_info *);
 297 static struct dentry *nfs_fs_mount(struct file_system_type *,
 298                 int, const char *, void *);
 299 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
 300                 int flags, const char *dev_name, void *raw_data);
 301 static void nfs_put_super(struct super_block *);
 302 static void nfs_kill_super(struct super_block *);
 303 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 304
 305 static struct file_system_type nfs_fs_type = {
 306         .owner          = THIS_MODULE,
 307         .name           = "nfs",
 308         .mount          = nfs_fs_mount,
 309         .kill_sb        = nfs_kill_super,
 310         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 311 };
 312
 313 struct file_system_type nfs_xdev_fs_type = {
 314         .owner          = THIS_MODULE,
 315         .name           = "nfs",
 316         .mount          = nfs_xdev_mount,
 317         .kill_sb        = nfs_kill_super,
 318         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 319 };
 320
 321 static const struct super_operations nfs_sops = {
 322         .alloc_inode    = nfs_alloc_inode,
 323         .destroy_inode  = nfs_destroy_inode,
 324         .write_inode    = nfs_write_inode,
 325         .put_super      = nfs_put_super,
 326         .statfs         = nfs_statfs,
 327         .evict_inode    = nfs_evict_inode,
 328         .umount_begin   = nfs_umount_begin,
 329         .show_options   = nfs_show_options,
 330         .show_devname   = nfs_show_devname,
 331         .show_path      = nfs_show_path,
 332         .show_stats     = nfs_show_stats,
 333         .remount_fs     = nfs_remount,
 334 };
 335
 336 #ifdef CONFIG_NFS_V4
 337 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
 338 static int nfs4_validate_mount_data(void *options,
 339         struct nfs_parsed_mount_data *args, const char *dev_name);
 340 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
 341         struct nfs_mount_info *mount_info);
 342 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 343         int flags, const char *dev_name, void *raw_data);
 344 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
 345         int flags, const char *dev_name, void *raw_data);
 346 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 347         int flags, const char *dev_name, void *raw_data);
 348 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 349         int flags, const char *dev_name, void *raw_data);
 350 static void nfs4_kill_super(struct super_block *sb);
 351
 352 static struct file_system_type nfs4_fs_type = {
 353         .owner          = THIS_MODULE,
 354         .name           = "nfs4",
 355         .mount          = nfs_fs_mount,
 356         .kill_sb        = nfs4_kill_super,
 357         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 358 };
 359
 360 static struct file_system_type nfs4_remote_fs_type = {
 361         .owner          = THIS_MODULE,
 362         .name           = "nfs4",
 363         .mount          = nfs4_remote_mount,
 364         .kill_sb        = nfs4_kill_super,
 365         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 366 };
 367
 368 struct file_system_type nfs4_xdev_fs_type = {
 369         .owner          = THIS_MODULE,
 370         .name           = "nfs4",
 371         .mount          = nfs4_xdev_mount,
 372         .kill_sb        = nfs4_kill_super,
 373         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 374 };
 375
 376 static struct file_system_type nfs4_remote_referral_fs_type = {
 377         .owner          = THIS_MODULE,
 378         .name           = "nfs4",
 379         .mount          = nfs4_remote_referral_mount,
 380         .kill_sb        = nfs4_kill_super,
 381         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 382 };
 383
 384 struct file_system_type nfs4_referral_fs_type = {
 385         .owner          = THIS_MODULE,
 386         .name           = "nfs4",
 387         .mount          = nfs4_referral_mount,
 388         .kill_sb        = nfs4_kill_super,
 389         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 390 };
 391
 392 static const struct super_operations nfs4_sops = {
 393         .alloc_inode    = nfs_alloc_inode,
 394         .destroy_inode  = nfs_destroy_inode,
 395         .write_inode    = nfs_write_inode,
 396         .put_super      = nfs_put_super,
 397         .statfs         = nfs_statfs,
 398         .evict_inode    = nfs4_evict_inode,
 399         .umount_begin   = nfs_umount_begin,
 400         .show_options   = nfs_show_options,
 401         .show_devname   = nfs_show_devname,
 402         .show_path      = nfs_show_path,
 403         .show_stats     = nfs_show_stats,
 404         .remount_fs     = nfs_remount,
 405 };
 406 #endif
 407
 408 static struct shrinker acl_shrinker = {
 409         .shrink         = nfs_access_cache_shrinker,
 410         .seeks          = DEFAULT_SEEKS,
 411 };
 412
 413 /*
 414  * Register the NFS filesystems
 415  */
 416 int __init register_nfs_fs(void)
 417 {
 418         int ret;
 419
 420         ret = register_filesystem(&nfs_fs_type);
 421         if (ret < 0)
 422                 goto error_0;
 423
 424         ret = nfs_register_sysctl();
 425         if (ret < 0)
 426                 goto error_1;
 427 #ifdef CONFIG_NFS_V4
 428         ret = register_filesystem(&nfs4_fs_type);
 429         if (ret < 0)
 430                 goto error_2;
 431 #endif
 432         register_shrinker(&acl_shrinker);
 433         return 0;
 434
 435 #ifdef CONFIG_NFS_V4
 436 error_2:
 437         nfs_unregister_sysctl();
 438 #endif
 439 error_1:
 440         unregister_filesystem(&nfs_fs_type);
 441 error_0:
 442         return ret;
 443 }
 444
 445 /*
 446  * Unregister the NFS filesystems
 447  */
 448 void __exit unregister_nfs_fs(void)
 449 {
 450         unregister_shrinker(&acl_shrinker);
 451 #ifdef CONFIG_NFS_V4
 452         unregister_filesystem(&nfs4_fs_type);
 453 #endif
 454         nfs_unregister_sysctl();
 455         unregister_filesystem(&nfs_fs_type);
 456 }
 457
 458 void nfs_sb_active(struct super_block *sb)
 459 {
 460         struct nfs_server *server = NFS_SB(sb);
 461
 462         if (atomic_inc_return(&server->active) == 1)
 463                 atomic_inc(&sb->s_active);
 464 }
 465
 466 void nfs_sb_deactive(struct super_block *sb)
 467 {
 468         struct nfs_server *server = NFS_SB(sb);
 469
 470         if (atomic_dec_and_test(&server->active))
 471                 deactivate_super(sb);
 472 }
 473
 474 /*
 475  * Deliver file system statistics to userspace
 476  */
 477 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 478 {
 479         struct nfs_server *server = NFS_SB(dentry->d_sb);
 480         unsigned char blockbits;
 481         unsigned long blockres;
 482         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 483         struct nfs_fsstat res;
 484         int error = -ENOMEM;
 485
 486         res.fattr = nfs_alloc_fattr();
 487         if (res.fattr == NULL)
 488                 goto out_err;
 489
 490         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 491         if (unlikely(error == -ESTALE)) {
 492                 struct dentry *pd_dentry;
 493
 494                 pd_dentry = dget_parent(dentry);
 495                 if (pd_dentry != NULL) {
 496                         nfs_zap_caches(pd_dentry->d_inode);
 497                         dput(pd_dentry);
 498                 }
 499         }
 500         nfs_free_fattr(res.fattr);
 501         if (error < 0)
 502                 goto out_err;
 503
 504         buf->f_type = NFS_SUPER_MAGIC;
 505
 506         /*
 507          * Current versions of glibc do not correctly handle the
 508          * case where f_frsize != f_bsize.  Eventually we want to
 509          * report the value of wtmult in this field.
 510          */
 511         buf->f_frsize = dentry->d_sb->s_blocksize;
 512
 513         /*
 514          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 515          * are reported in units of f_frsize.  Linux hasn't had
 516          * an f_frsize field in its statfs struct until recently,
 517          * thus historically Linux's sys_statfs reports these
 518          * fields in units of f_bsize.
 519          */
 520         buf->f_bsize = dentry->d_sb->s_blocksize;
 521         blockbits = dentry->d_sb->s_blocksize_bits;
 522         blockres = (1 << blockbits) - 1;
 523         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 524         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 525         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 526
 527         buf->f_files = res.tfiles;
 528         buf->f_ffree = res.afiles;
 529
 530         buf->f_namelen = server->namelen;
 531
 532         return 0;
 533
 534  out_err:
 535         dprintk("%s: statfs error = %d\n", __func__, -error);
 536         return error;
 537 }
 538
 539 /*
 540  * Map the security flavour number to a name
 541  */
 542 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 543 {
 544         static const struct {
 545                 rpc_authflavor_t flavour;
 546                 const char *str;
 547         } sec_flavours[] = {
 548                 { RPC_AUTH_NULL, "null" },
 549                 { RPC_AUTH_UNIX, "sys" },
 550                 { RPC_AUTH_GSS_KRB5, "krb5" },
 551                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 552                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 553                 { RPC_AUTH_GSS_LKEY, "lkey" },
 554                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 555                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 556                 { RPC_AUTH_GSS_SPKM, "spkm" },
 557                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 558                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 559                 { UINT_MAX, "unknown" }
 560         };
 561         int i;
 562
 563         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 564                 if (sec_flavours[i].flavour == flavour)
 565                         break;
 566         }
 567         return sec_flavours[i].str;
 568 }
 569
 570 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
 571                                   int showdefaults)
 572 {
 573         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
 574
 575         seq_printf(m, ",mountproto=");
 576         switch (sap->sa_family) {
 577         case AF_INET:
 578                 switch (nfss->mountd_protocol) {
 579                 case IPPROTO_UDP:
 580                         seq_printf(m, RPCBIND_NETID_UDP);
 581                         break;
 582                 case IPPROTO_TCP:
 583                         seq_printf(m, RPCBIND_NETID_TCP);
 584                         break;
 585                 default:
 586                         if (showdefaults)
 587                                 seq_printf(m, "auto");
 588                 }
 589                 break;
 590         case AF_INET6:
 591                 switch (nfss->mountd_protocol) {
 592                 case IPPROTO_UDP:
 593                         seq_printf(m, RPCBIND_NETID_UDP6);
 594                         break;
 595                 case IPPROTO_TCP:
 596                         seq_printf(m, RPCBIND_NETID_TCP6);
 597                         break;
 598                 default:
 599                         if (showdefaults)
 600                                 seq_printf(m, "auto");
 601                 }
 602                 break;
 603         default:
 604                 if (showdefaults)
 605                         seq_printf(m, "auto");
 606         }
 607 }
 608
 609 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 610                                     int showdefaults)
 611 {
 612         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 613
 614         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
 615                 return;
 616
 617         switch (sap->sa_family) {
 618         case AF_INET: {
 619                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 620                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 621                 break;
 622         }
 623         case AF_INET6: {
 624                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 625                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
 626                 break;
 627         }
 628         default:
 629                 if (showdefaults)
 630                         seq_printf(m, ",mountaddr=unspecified");
 631         }
 632
 633         if (nfss->mountd_version || showdefaults)
 634                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 635         if ((nfss->mountd_port &&
 636                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
 637                 showdefaults)
 638                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 639
 640         nfs_show_mountd_netid(m, nfss, showdefaults);
 641 }
 642
 643 #ifdef CONFIG_NFS_V4
 644 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 645                                     int showdefaults)
 646 {
 647         struct nfs_client *clp = nfss->nfs_client;
 648
 649         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 650 }
 651 #else
 652 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
 653                                     int showdefaults)
 654 {
 655 }
 656 #endif
 657
 658 static void nfs_show_nfs_version(struct seq_file *m,
 659                 unsigned int version,
 660                 unsigned int minorversion)
 661 {
 662         seq_printf(m, ",vers=%u", version);
 663         if (version == 4)
 664                 seq_printf(m, ".%u", minorversion);
 665 }
 666
 667 /*
 668  * Describe the mount options in force on this server representation
 669  */
 670 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 671                                    int showdefaults)
 672 {
 673         static const struct proc_nfs_info {
 674                 int flag;
 675                 const char *str;
 676                 const char *nostr;
 677         } nfs_info[] = {
 678                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 679                 { NFS_MOUNT_POSIX, ",posix", "" },
 680                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 681                 { NFS_MOUNT_NOAC, ",noac", "" },
 682                 { NFS_MOUNT_NONLM, ",nolock", "" },
 683                 { NFS_MOUNT_NOACL, ",noacl", "" },
 684                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 685                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 686                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 687                 { 0, NULL, NULL }
 688         };
 689         const struct proc_nfs_info *nfs_infop;
 690         struct nfs_client *clp = nfss->nfs_client;
 691         u32 version = clp->rpc_ops->version;
 692         int local_flock, local_fcntl;
 693
 694         nfs_show_nfs_version(m, version, clp->cl_minorversion);
 695         seq_printf(m, ",rsize=%u", nfss->rsize);
 696         seq_printf(m, ",wsize=%u", nfss->wsize);
 697         if (nfss->bsize != 0)
 698                 seq_printf(m, ",bsize=%u", nfss->bsize);
 699         seq_printf(m, ",namlen=%u", nfss->namelen);
 700         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 701                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 702         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 703                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 704         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 705                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 706         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 707                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 708         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 709                 if (nfss->flags & nfs_infop->flag)
 710                         seq_puts(m, nfs_infop->str);
 711                 else
 712                         seq_puts(m, nfs_infop->nostr);
 713         }
 714         rcu_read_lock();
 715         seq_printf(m, ",proto=%s",
 716                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
 717         rcu_read_unlock();
 718         if (version == 4) {
 719                 if (nfss->port != NFS_PORT)
 720                         seq_printf(m, ",port=%u", nfss->port);
 721         } else
 722                 if (nfss->port)
 723                         seq_printf(m, ",port=%u", nfss->port);
 724
 725         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 726         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 727         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 728
 729         if (version != 4)
 730                 nfs_show_mountd_options(m, nfss, showdefaults);
 731         else
 732                 nfs_show_nfsv4_options(m, nfss, showdefaults);
 733
 734         if (nfss->options & NFS_OPTION_FSCACHE)
 735                 seq_printf(m, ",fsc");
 736
 737         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
 738                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
 739                         seq_printf(m, ",lookupcache=none");
 740                 else
 741                         seq_printf(m, ",lookupcache=pos");
 742         }
 743
 744         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
 745         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
 746
 747         if (!local_flock && !local_fcntl)
 748                 seq_printf(m, ",local_lock=none");
 749         else if (local_flock && local_fcntl)
 750                 seq_printf(m, ",local_lock=all");
 751         else if (local_flock)
 752                 seq_printf(m, ",local_lock=flock");
 753         else
 754                 seq_printf(m, ",local_lock=posix");
 755 }
 756
 757 /*
 758  * Describe the mount options on this VFS mountpoint
 759  */
 760 static int nfs_show_options(struct seq_file *m, struct dentry *root)
 761 {
 762         struct nfs_server *nfss = NFS_SB(root->d_sb);
 763
 764         nfs_show_mount_options(m, nfss, 0);
 765
 766         rcu_read_lock();
 767         seq_printf(m, ",addr=%s",
 768                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 769                                                         RPC_DISPLAY_ADDR));
 770         rcu_read_unlock();
 771
 772         return 0;
 773 }
 774
 775 #ifdef CONFIG_NFS_V4
 776 #ifdef CONFIG_NFS_V4_1
 777 static void show_sessions(struct seq_file *m, struct nfs_server *server)
 778 {
 779         if (nfs4_has_session(server->nfs_client))
 780                 seq_printf(m, ",sessions");
 781 }
 782 #else
 783 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
 784 #endif
 785 #endif
 786
 787 #ifdef CONFIG_NFS_V4_1
 788 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 789 {
 790         seq_printf(m, ",pnfs=");
 791         if (server->pnfs_curr_ld)
 792                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
 793         else
 794                 seq_printf(m, "not configured");
 795 }
 796
 797 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 798 {
 799         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
 800                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
 801                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
 802                            "date='%llu,%u'",
 803                            impl_id->name, impl_id->domain,
 804                            impl_id->date.seconds, impl_id->date.nseconds);
 805         }
 806 }
 807 #else
 808 #ifdef CONFIG_NFS_V4
 809 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
 810 {
 811 }
 812 #endif
 813 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
 814 {
 815 }
 816 #endif
 817
 818 static int nfs_show_devname(struct seq_file *m, struct dentry *root)
 819 {
 820         char *page = (char *) __get_free_page(GFP_KERNEL);
 821         char *devname, *dummy;
 822         int err = 0;
 823         if (!page)
 824                 return -ENOMEM;
 825         devname = nfs_path(&dummy, root, page, PAGE_SIZE);
 826         if (IS_ERR(devname))
 827                 err = PTR_ERR(devname);
 828         else
 829                 seq_escape(m, devname, " \t\n\\");
 830         free_page((unsigned long)page);
 831         return err;
 832 }
 833
 834 static int nfs_show_path(struct seq_file *m, struct dentry *dentry)
 835 {
 836         seq_puts(m, "/");
 837         return 0;
 838 }
 839
 840 /*
 841  * Present statistical information for this VFS mountpoint
 842  */
 843 static int nfs_show_stats(struct seq_file *m, struct dentry *root)
 844 {
 845         int i, cpu;
 846         struct nfs_server *nfss = NFS_SB(root->d_sb);
 847         struct rpc_auth *auth = nfss->client->cl_auth;
 848         struct nfs_iostats totals = { };
 849
 850         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 851
 852         /*
 853          * Display all mount option settings
 854          */
 855         seq_printf(m, "\n\topts:\t");
 856         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 857         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 858         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 859         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 860         nfs_show_mount_options(m, nfss, 1);
 861
 862         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 863
 864         show_implementation_id(m, nfss);
 865
 866         seq_printf(m, "\n\tcaps:\t");
 867         seq_printf(m, "caps=0x%x", nfss->caps);
 868         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 869         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 870         seq_printf(m, ",bsize=%u", nfss->bsize);
 871         seq_printf(m, ",namlen=%u", nfss->namelen);
 872
 873 #ifdef CONFIG_NFS_V4
 874         if (nfss->nfs_client->rpc_ops->version == 4) {
 875                 seq_printf(m, "\n\tnfsv4:\t");
 876                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 877                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 878                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 879                 show_sessions(m, nfss);
 880                 show_pnfs(m, nfss);
 881         }
 882 #endif
 883
 884         /*
 885          * Display security flavor in effect for this mount
 886          */
 887         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 888         if (auth->au_flavor)
 889                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 890
 891         /*
 892          * Display superblock I/O counters
 893          */
 894         for_each_possible_cpu(cpu) {
 895                 struct nfs_iostats *stats;
 896
 897                 preempt_disable();
 898                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 899
 900                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 901                         totals.events[i] += stats->events[i];
 902                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 903                         totals.bytes[i] += stats->bytes[i];
 904 #ifdef CONFIG_NFS_FSCACHE
 905                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 906                         totals.fscache[i] += stats->fscache[i];
 907 #endif
 908
 909                 preempt_enable();
 910         }
 911
 912         seq_printf(m, "\n\tevents:\t");
 913         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 914                 seq_printf(m, "%lu ", totals.events[i]);
 915         seq_printf(m, "\n\tbytes:\t");
 916         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 917                 seq_printf(m, "%Lu ", totals.bytes[i]);
 918 #ifdef CONFIG_NFS_FSCACHE
 919         if (nfss->options & NFS_OPTION_FSCACHE) {
 920                 seq_printf(m, "\n\tfsc:\t");
 921                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 922                         seq_printf(m, "%Lu ", totals.bytes[i]);
 923         }
 924 #endif
 925         seq_printf(m, "\n");
 926
 927         rpc_print_iostats(m, nfss->client);
 928
 929         return 0;
 930 }
 931
 932 /*
 933  * Begin unmount by attempting to remove all automounted mountpoints we added
 934  * in response to xdev traversals and referrals
 935  */
 936 static void nfs_umount_begin(struct super_block *sb)
 937 {
 938         struct nfs_server *server;
 939         struct rpc_clnt *rpc;
 940
 941         server = NFS_SB(sb);
 942         /* -EIO all pending I/O */
 943         rpc = server->client_acl;
 944         if (!IS_ERR(rpc))
 945                 rpc_killall_tasks(rpc);
 946         rpc = server->client;
 947         if (!IS_ERR(rpc))
 948                 rpc_killall_tasks(rpc);
 949 }
 950
 951 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 952 {
 953         struct nfs_parsed_mount_data *data;
 954
 955         data = kzalloc(sizeof(*data), GFP_KERNEL);
 956         if (data) {
 957                 data->acregmin          = NFS_DEF_ACREGMIN;
 958                 data->acregmax          = NFS_DEF_ACREGMAX;
 959                 data->acdirmin          = NFS_DEF_ACDIRMIN;
 960                 data->acdirmax          = NFS_DEF_ACDIRMAX;
 961                 data->mount_server.port = NFS_UNSPEC_PORT;
 962                 data->nfs_server.port   = NFS_UNSPEC_PORT;
 963                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 964                 data->auth_flavors[0]   = RPC_AUTH_UNIX;
 965                 data->auth_flavor_len   = 1;
 966                 data->minorversion      = 0;
 967                 data->need_mount        = true;
 968                 data->net               = current->nsproxy->net_ns;
 969                 security_init_mnt_opts(&data->lsm_opts);
 970         }
 971         return data;
 972 }
 973
 974 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
 975 {
 976         if (data) {
 977                 kfree(data->client_address);
 978                 kfree(data->mount_server.hostname);
 979                 kfree(data->nfs_server.export_path);
 980                 kfree(data->nfs_server.hostname);
 981                 kfree(data->fscache_uniq);
 982                 security_free_mnt_opts(&data->lsm_opts);
 983                 kfree(data);
 984         }
 985 }
 986
 987 /*
 988  * Sanity-check a server address provided by the mount command.
 989  *
 990  * Address family must be initialized, and address must not be
 991  * the ANY address for that family.
 992  */
 993 static int nfs_verify_server_address(struct sockaddr *addr)
 994 {
 995         switch (addr->sa_family) {
 996         case AF_INET: {
 997                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 998                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 999         }
1000         case AF_INET6: {
1001                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
1002                 return !ipv6_addr_any(sa);
1003         }
1004         }
1005
1006         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
1007         return 0;
1008 }
1009
1010 /*
1011  * Select between a default port value and a user-specified port value.
1012  * If a zero value is set, then autobind will be used.
1013  */
1014 static void nfs_set_port(struct sockaddr *sap, int *port,
1015                                  const unsigned short default_port)
1016 {
1017         if (*port == NFS_UNSPEC_PORT)
1018                 *port = default_port;
1019
1020         rpc_set_port(sap, *port);
1021 }
1022
1023 /*
1024  * Sanity check the NFS transport protocol.
1025  *
1026  */
1027 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1028 {
1029         switch (mnt->nfs_server.protocol) {
1030         case XPRT_TRANSPORT_UDP:
1031         case XPRT_TRANSPORT_TCP:
1032         case XPRT_TRANSPORT_RDMA:
1033                 break;
1034         default:
1035                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1036         }
1037 }
1038
1039 /*
1040  * For text based NFSv2/v3 mounts, the mount protocol transport default
1041  * settings should depend upon the specified NFS transport.
1042  */
1043 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1044 {
1045         nfs_validate_transport_protocol(mnt);
1046
1047         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1048             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1049                         return;
1050         switch (mnt->nfs_server.protocol) {
1051         case XPRT_TRANSPORT_UDP:
1052                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1053                 break;
1054         case XPRT_TRANSPORT_TCP:
1055         case XPRT_TRANSPORT_RDMA:
1056                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1057         }
1058 }
1059
1060 /*
1061  * Parse the value of the 'sec=' option.
1062  */
1063 static int nfs_parse_security_flavors(char *value,
1064                                       struct nfs_parsed_mount_data *mnt)
1065 {
1066         substring_t args[MAX_OPT_ARGS];
1067
1068         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1069
1070         switch (match_token(value, nfs_secflavor_tokens, args)) {
1071         case Opt_sec_none:
1072                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
1073                 break;
1074         case Opt_sec_sys:
1075                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1076                 break;
1077         case Opt_sec_krb5:
1078                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1079                 break;
1080         case Opt_sec_krb5i:
1081                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1082                 break;
1083         case Opt_sec_krb5p:
1084                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1085                 break;
1086         case Opt_sec_lkey:
1087                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1088                 break;
1089         case Opt_sec_lkeyi:
1090                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1091                 break;
1092         case Opt_sec_lkeyp:
1093                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1094                 break;
1095         case Opt_sec_spkm:
1096                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1097                 break;
1098         case Opt_sec_spkmi:
1099                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1100                 break;
1101         case Opt_sec_spkmp:
1102                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1103                 break;
1104         default:
1105                 return 0;
1106         }
1107
1108         mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1109         mnt->auth_flavor_len = 1;
1110         return 1;
1111 }
1112
1113 static int nfs_parse_version_string(char *string,
1114                 struct nfs_parsed_mount_data *mnt,
1115                 substring_t *args)
1116 {
1117         mnt->flags &= ~NFS_MOUNT_VER3;
1118         switch (match_token(string, nfs_vers_tokens, args)) {
1119         case Opt_vers_2:
1120                 mnt->version = 2;
1121                 break;
1122         case Opt_vers_3:
1123                 mnt->flags |= NFS_MOUNT_VER3;
1124                 mnt->version = 3;
1125                 break;
1126         case Opt_vers_4:
1127                 /* Backward compatibility option. In future,
1128                  * the mount program should always supply
1129                  * a NFSv4 minor version number.
1130                  */
1131                 mnt->version = 4;
1132                 break;
1133         case Opt_vers_4_0:
1134                 mnt->version = 4;
1135                 mnt->minorversion = 0;
1136                 break;
1137         case Opt_vers_4_1:
1138                 mnt->version = 4;
1139                 mnt->minorversion = 1;
1140                 break;
1141         default:
1142                 return 0;
1143         }
1144         return 1;
1145 }
1146
1147 static int nfs_get_option_str(substring_t args[], char **option)
1148 {
1149         kfree(*option);
1150         *option = match_strdup(args);
1151         return !option;
1152 }
1153
1154 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1155 {
1156         int rc;
1157         char *string;
1158
1159         string = match_strdup(args);
1160         if (string == NULL)
1161                 return -ENOMEM;
1162         rc = strict_strtoul(string, 10, option);
1163         kfree(string);
1164
1165         return rc;
1166 }
1167
1168 /*
1169  * Error-check and convert a string of mount options from user space into
1170  * a data structure.  The whole mount string is processed; bad options are
1171  * skipped as they are encountered.  If there were no errors, return 1;
1172  * otherwise return 0 (zero).
1173  */
1174 static int nfs_parse_mount_options(char *raw,
1175                                    struct nfs_parsed_mount_data *mnt)
1176 {
1177         char *p, *string, *secdata;
1178         int rc, sloppy = 0, invalid_option = 0;
1179         unsigned short protofamily = AF_UNSPEC;
1180         unsigned short mountfamily = AF_UNSPEC;
1181
1182         if (!raw) {
1183                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1184                 return 1;
1185         }
1186         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1187
1188         secdata = alloc_secdata();
1189         if (!secdata)
1190                 goto out_nomem;
1191
1192         rc = security_sb_copy_data(raw, secdata);
1193         if (rc)
1194                 goto out_security_failure;
1195
1196         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1197         if (rc)
1198                 goto out_security_failure;
1199
1200         free_secdata(secdata);
1201
1202         while ((p = strsep(&raw, ",")) != NULL) {
1203                 substring_t args[MAX_OPT_ARGS];
1204                 unsigned long option;
1205                 int token;
1206
1207                 if (!*p)
1208                         continue;
1209
1210                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1211
1212                 token = match_token(p, nfs_mount_option_tokens, args);
1213                 switch (token) {
1214
1215                 /*
1216                  * boolean options:  foo/nofoo
1217                  */
1218                 case Opt_soft:
1219                         mnt->flags |= NFS_MOUNT_SOFT;
1220                         break;
1221                 case Opt_hard:
1222                         mnt->flags &= ~NFS_MOUNT_SOFT;
1223                         break;
1224                 case Opt_posix:
1225                         mnt->flags |= NFS_MOUNT_POSIX;
1226                         break;
1227                 case Opt_noposix:
1228                         mnt->flags &= ~NFS_MOUNT_POSIX;
1229                         break;
1230                 case Opt_cto:
1231                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1232                         break;
1233                 case Opt_nocto:
1234                         mnt->flags |= NFS_MOUNT_NOCTO;
1235                         break;
1236                 case Opt_ac:
1237                         mnt->flags &= ~NFS_MOUNT_NOAC;
1238                         break;
1239                 case Opt_noac:
1240                         mnt->flags |= NFS_MOUNT_NOAC;
1241                         break;
1242                 case Opt_lock:
1243                         mnt->flags &= ~NFS_MOUNT_NONLM;
1244                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1245                                         NFS_MOUNT_LOCAL_FCNTL);
1246                         break;
1247                 case Opt_nolock:
1248                         mnt->flags |= NFS_MOUNT_NONLM;
1249                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1250                                        NFS_MOUNT_LOCAL_FCNTL);
1251                         break;
1252                 case Opt_udp:
1253                         mnt->flags &= ~NFS_MOUNT_TCP;
1254                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1255                         break;
1256                 case Opt_tcp:
1257                         mnt->flags |= NFS_MOUNT_TCP;
1258                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1259                         break;
1260                 case Opt_rdma:
1261                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1262                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1263                         xprt_load_transport(p);
1264                         break;
1265                 case Opt_acl:
1266                         mnt->flags &= ~NFS_MOUNT_NOACL;
1267                         break;
1268                 case Opt_noacl:
1269                         mnt->flags |= NFS_MOUNT_NOACL;
1270                         break;
1271                 case Opt_rdirplus:
1272                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1273                         break;
1274                 case Opt_nordirplus:
1275                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1276                         break;
1277                 case Opt_sharecache:
1278                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1279                         break;
1280                 case Opt_nosharecache:
1281                         mnt->flags |= NFS_MOUNT_UNSHARED;
1282                         break;
1283                 case Opt_resvport:
1284                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1285                         break;
1286                 case Opt_noresvport:
1287                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1288                         break;
1289                 case Opt_fscache:
1290                         mnt->options |= NFS_OPTION_FSCACHE;
1291                         kfree(mnt->fscache_uniq);
1292                         mnt->fscache_uniq = NULL;
1293                         break;
1294                 case Opt_nofscache:
1295                         mnt->options &= ~NFS_OPTION_FSCACHE;
1296                         kfree(mnt->fscache_uniq);
1297                         mnt->fscache_uniq = NULL;
1298                         break;
1299
1300                 /*
1301                  * options that take numeric values
1302                  */
1303                 case Opt_port:
1304                         if (nfs_get_option_ul(args, &option) ||
1305                             option > USHRT_MAX)
1306                                 goto out_invalid_value;
1307                         mnt->nfs_server.port = option;
1308                         break;
1309                 case Opt_rsize:
1310                         if (nfs_get_option_ul(args, &option))
1311                                 goto out_invalid_value;
1312                         mnt->rsize = option;
1313                         break;
1314                 case Opt_wsize:
1315                         if (nfs_get_option_ul(args, &option))
1316                                 goto out_invalid_value;
1317                         mnt->wsize = option;
1318                         break;
1319                 case Opt_bsize:
1320                         if (nfs_get_option_ul(args, &option))
1321                                 goto out_invalid_value;
1322                         mnt->bsize = option;
1323                         break;
1324                 case Opt_timeo:
1325                         if (nfs_get_option_ul(args, &option) || option == 0)
1326                                 goto out_invalid_value;
1327                         mnt->timeo = option;
1328                         break;
1329                 case Opt_retrans:
1330                         if (nfs_get_option_ul(args, &option) || option == 0)
1331                                 goto out_invalid_value;
1332                         mnt->retrans = option;
1333                         break;
1334                 case Opt_acregmin:
1335                         if (nfs_get_option_ul(args, &option))
1336                                 goto out_invalid_value;
1337                         mnt->acregmin = option;
1338                         break;
1339                 case Opt_acregmax:
1340                         if (nfs_get_option_ul(args, &option))
1341                                 goto out_invalid_value;
1342                         mnt->acregmax = option;
1343                         break;
1344                 case Opt_acdirmin:
1345                         if (nfs_get_option_ul(args, &option))
1346                                 goto out_invalid_value;
1347                         mnt->acdirmin = option;
1348                         break;
1349                 case Opt_acdirmax:
1350                         if (nfs_get_option_ul(args, &option))
1351                                 goto out_invalid_value;
1352                         mnt->acdirmax = option;
1353                         break;
1354                 case Opt_actimeo:
1355                         if (nfs_get_option_ul(args, &option))
1356                                 goto out_invalid_value;
1357                         mnt->acregmin = mnt->acregmax =
1358                         mnt->acdirmin = mnt->acdirmax = option;
1359                         break;
1360                 case Opt_namelen:
1361                         if (nfs_get_option_ul(args, &option))
1362                                 goto out_invalid_value;
1363                         mnt->namlen = option;
1364                         break;
1365                 case Opt_mountport:
1366                         if (nfs_get_option_ul(args, &option) ||
1367                             option > USHRT_MAX)
1368                                 goto out_invalid_value;
1369                         mnt->mount_server.port = option;
1370                         break;
1371                 case Opt_mountvers:
1372                         if (nfs_get_option_ul(args, &option) ||
1373                             option < NFS_MNT_VERSION ||
1374                             option > NFS_MNT3_VERSION)
1375                                 goto out_invalid_value;
1376                         mnt->mount_server.version = option;
1377                         break;
1378                 case Opt_minorversion:
1379                         if (nfs_get_option_ul(args, &option))
1380                                 goto out_invalid_value;
1381                         if (option > NFS4_MAX_MINOR_VERSION)
1382                                 goto out_invalid_value;
1383                         mnt->minorversion = option;
1384                         break;
1385
1386                 /*
1387                  * options that take text values
1388                  */
1389                 case Opt_nfsvers:
1390                         string = match_strdup(args);
1391                         if (string == NULL)
1392                                 goto out_nomem;
1393                         rc = nfs_parse_version_string(string, mnt, args);
1394                         kfree(string);
1395                         if (!rc)
1396                                 goto out_invalid_value;
1397                         break;
1398                 case Opt_sec:
1399                         string = match_strdup(args);
1400                         if (string == NULL)
1401                                 goto out_nomem;
1402                         rc = nfs_parse_security_flavors(string, mnt);
1403                         kfree(string);
1404                         if (!rc) {
1405                                 dfprintk(MOUNT, "NFS:   unrecognized "
1406                                                 "security flavor\n");
1407                                 return 0;
1408                         }
1409                         break;
1410                 case Opt_proto:
1411                         string = match_strdup(args);
1412                         if (string == NULL)
1413                                 goto out_nomem;
1414                         token = match_token(string,
1415                                             nfs_xprt_protocol_tokens, args);
1416
1417                         protofamily = AF_INET;
1418                         switch (token) {
1419                         case Opt_xprt_udp6:
1420                                 protofamily = AF_INET6;
1421                         case Opt_xprt_udp:
1422                                 mnt->flags &= ~NFS_MOUNT_TCP;
1423                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1424                                 break;
1425                         case Opt_xprt_tcp6:
1426                                 protofamily = AF_INET6;
1427                         case Opt_xprt_tcp:
1428                                 mnt->flags |= NFS_MOUNT_TCP;
1429                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1430                                 break;
1431                         case Opt_xprt_rdma:
1432                                 /* vector side protocols to TCP */
1433                                 mnt->flags |= NFS_MOUNT_TCP;
1434                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1435                                 xprt_load_transport(string);
1436                                 break;
1437                         default:
1438                                 dfprintk(MOUNT, "NFS:   unrecognized "
1439                                                 "transport protocol\n");
1440                                 kfree(string);
1441                                 return 0;
1442                         }
1443                         kfree(string);
1444                         break;
1445                 case Opt_mountproto:
1446                         string = match_strdup(args);
1447                         if (string == NULL)
1448                                 goto out_nomem;
1449                         token = match_token(string,
1450                                             nfs_xprt_protocol_tokens, args);
1451                         kfree(string);
1452
1453                         mountfamily = AF_INET;
1454                         switch (token) {
1455                         case Opt_xprt_udp6:
1456                                 mountfamily = AF_INET6;
1457                         case Opt_xprt_udp:
1458                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1459                                 break;
1460                         case Opt_xprt_tcp6:
1461                                 mountfamily = AF_INET6;
1462                         case Opt_xprt_tcp:
1463                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1464                                 break;
1465                         case Opt_xprt_rdma: /* not used for side protocols */
1466                         default:
1467                                 dfprintk(MOUNT, "NFS:   unrecognized "
1468                                                 "transport protocol\n");
1469                                 return 0;
1470                         }
1471                         break;
1472                 case Opt_addr:
1473                         string = match_strdup(args);
1474                         if (string == NULL)
1475                                 goto out_nomem;
1476                         mnt->nfs_server.addrlen =
1477                                 rpc_pton(mnt->net, string, strlen(string),
1478                                         (struct sockaddr *)
1479                                         &mnt->nfs_server.address,
1480                                         sizeof(mnt->nfs_server.address));
1481                         kfree(string);
1482                         if (mnt->nfs_server.addrlen == 0)
1483                                 goto out_invalid_address;
1484                         break;
1485                 case Opt_clientaddr:
1486                         if (nfs_get_option_str(args, &mnt->client_address))
1487                                 goto out_nomem;
1488                         break;
1489                 case Opt_mounthost:
1490                         if (nfs_get_option_str(args,
1491                                                &mnt->mount_server.hostname))
1492                                 goto out_nomem;
1493                         break;
1494                 case Opt_mountaddr:
1495                         string = match_strdup(args);
1496                         if (string == NULL)
1497                                 goto out_nomem;
1498                         mnt->mount_server.addrlen =
1499                                 rpc_pton(mnt->net, string, strlen(string),
1500                                         (struct sockaddr *)
1501                                         &mnt->mount_server.address,
1502                                         sizeof(mnt->mount_server.address));
1503                         kfree(string);
1504                         if (mnt->mount_server.addrlen == 0)
1505                                 goto out_invalid_address;
1506                         break;
1507                 case Opt_lookupcache:
1508                         string = match_strdup(args);
1509                         if (string == NULL)
1510                                 goto out_nomem;
1511                         token = match_token(string,
1512                                         nfs_lookupcache_tokens, args);
1513                         kfree(string);
1514                         switch (token) {
1515                                 case Opt_lookupcache_all:
1516                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1517                                         break;
1518                                 case Opt_lookupcache_positive:
1519                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1520                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1521                                         break;
1522                                 case Opt_lookupcache_none:
1523                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1524                                         break;
1525                                 default:
1526                                         dfprintk(MOUNT, "NFS:   invalid "
1527                                                         "lookupcache argument\n");
1528                                         return 0;
1529                         };
1530                         break;
1531                 case Opt_fscache_uniq:
1532                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1533                                 goto out_nomem;
1534                         mnt->options |= NFS_OPTION_FSCACHE;
1535                         break;
1536                 case Opt_local_lock:
1537                         string = match_strdup(args);
1538                         if (string == NULL)
1539                                 goto out_nomem;
1540                         token = match_token(string, nfs_local_lock_tokens,
1541                                         args);
1542                         kfree(string);
1543                         switch (token) {
1544                         case Opt_local_lock_all:
1545                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1546                                                NFS_MOUNT_LOCAL_FCNTL);
1547                                 break;
1548                         case Opt_local_lock_flock:
1549                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1550                                 break;
1551                         case Opt_local_lock_posix:
1552                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1553                                 break;
1554                         case Opt_local_lock_none:
1555                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1556                                                 NFS_MOUNT_LOCAL_FCNTL);
1557                                 break;
1558                         default:
1559                                 dfprintk(MOUNT, "NFS:   invalid "
1560                                                 "local_lock argument\n");
1561                                 return 0;
1562                         };
1563                         break;
1564
1565                 /*
1566                  * Special options
1567                  */
1568                 case Opt_sloppy:
1569                         sloppy = 1;
1570                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1571                         break;
1572                 case Opt_userspace:
1573                 case Opt_deprecated:
1574                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1575                                         "'%s'\n", p);
1576                         break;
1577
1578                 default:
1579                         invalid_option = 1;
1580                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1581                                         "'%s'\n", p);
1582                 }
1583         }
1584
1585         if (!sloppy && invalid_option)
1586                 return 0;
1587
1588         if (mnt->minorversion && mnt->version != 4)
1589                 goto out_minorversion_mismatch;
1590
1591         /*
1592          * verify that any proto=/mountproto= options match the address
1593          * familiies in the addr=/mountaddr= options.
1594          */
1595         if (protofamily != AF_UNSPEC &&
1596             protofamily != mnt->nfs_server.address.ss_family)
1597                 goto out_proto_mismatch;
1598
1599         if (mountfamily != AF_UNSPEC) {
1600                 if (mnt->mount_server.addrlen) {
1601                         if (mountfamily != mnt->mount_server.address.ss_family)
1602                                 goto out_mountproto_mismatch;
1603                 } else {
1604                         if (mountfamily != mnt->nfs_server.address.ss_family)
1605                                 goto out_mountproto_mismatch;
1606                 }
1607         }
1608
1609         return 1;
1610
1611 out_mountproto_mismatch:
1612         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1613                          "option\n");
1614         return 0;
1615 out_proto_mismatch:
1616         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1617         return 0;
1618 out_invalid_address:
1619         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1620         return 0;
1621 out_invalid_value:
1622         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1623         return 0;
1624 out_minorversion_mismatch:
1625         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1626                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1627         return 0;
1628 out_nomem:
1629         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1630         return 0;
1631 out_security_failure:
1632         free_secdata(secdata);
1633         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1634         return 0;
1635 }
1636
1637 /*
1638  * Match the requested auth flavors with the list returned by
1639  * the server.  Returns zero and sets the mount's authentication
1640  * flavor on success; returns -EACCES if server does not support
1641  * the requested flavor.
1642  */
1643 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1644                              struct nfs_mount_request *request)
1645 {
1646         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1647
1648         /*
1649          * Certain releases of Linux's mountd return an empty
1650          * flavor list.  To prevent behavioral regression with
1651          * these servers (ie. rejecting mounts that used to
1652          * succeed), revert to pre-2.6.32 behavior (no checking)
1653          * if the returned flavor list is empty.
1654          */
1655         if (server_authlist_len == 0)
1656                 return 0;
1657
1658         /*
1659          * We avoid sophisticated negotiating here, as there are
1660          * plenty of cases where we can get it wrong, providing
1661          * either too little or too much security.
1662          *
1663          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1664          * flavor listed first.  However, some servers list
1665          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1666          * preferred default, in args->auth_flavors[0] if user
1667          * didn't specify sec= mount option.
1668          */
1669         for (i = 0; i < args->auth_flavor_len; i++)
1670                 for (j = 0; j < server_authlist_len; j++)
1671                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1672                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1673                                         request->auth_flavs[j]);
1674                                 args->auth_flavors[0] = request->auth_flavs[j];
1675                                 return 0;
1676                         }
1677
1678         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1679         nfs_umount(request);
1680         return -EACCES;
1681 }
1682
1683 /*
1684  * Use the remote server's MOUNT service to request the NFS file handle
1685  * corresponding to the provided path.
1686  */
1687 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1688                              struct nfs_fh *root_fh)
1689 {
1690         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1691         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1692         struct nfs_mount_request request = {
1693                 .sap            = (struct sockaddr *)
1694                                                 &args->mount_server.address,
1695                 .dirpath        = args->nfs_server.export_path,
1696                 .protocol       = args->mount_server.protocol,
1697                 .fh             = root_fh,
1698                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1699                 .auth_flav_len  = &server_authlist_len,
1700                 .auth_flavs     = server_authlist,
1701                 .net            = args->net,
1702         };
1703         int status;
1704
1705         if (args->mount_server.version == 0) {
1706                 switch (args->version) {
1707                         default:
1708                                 args->mount_server.version = NFS_MNT3_VERSION;
1709                                 break;
1710                         case 2:
1711                                 args->mount_server.version = NFS_MNT_VERSION;
1712                 }
1713         }
1714         request.version = args->mount_server.version;
1715
1716         if (args->mount_server.hostname)
1717                 request.hostname = args->mount_server.hostname;
1718         else
1719                 request.hostname = args->nfs_server.hostname;
1720
1721         /*
1722          * Construct the mount server's address.
1723          */
1724         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1725                 memcpy(request.sap, &args->nfs_server.address,
1726                        args->nfs_server.addrlen);
1727                 args->mount_server.addrlen = args->nfs_server.addrlen;
1728         }
1729         request.salen = args->mount_server.addrlen;
1730         nfs_set_port(request.sap, &args->mount_server.port, 0);
1731
1732         /*
1733          * Now ask the mount server to map our export path
1734          * to a file handle.
1735          */
1736         status = nfs_mount(&request);
1737         if (status != 0) {
1738                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1739                                 request.hostname, status);
1740                 return status;
1741         }
1742
1743         /*
1744          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1745          */
1746         if (args->mount_server.version != NFS_MNT3_VERSION)
1747                 return 0;
1748         return nfs_walk_authlist(args, &request);
1749 }
1750
1751 static struct dentry *nfs_try_mount(int flags, const char *dev_name,
1752                                     struct nfs_mount_info *mount_info)
1753 {
1754         int status;
1755         struct nfs_server *server;
1756
1757         if (mount_info->parsed->need_mount) {
1758                 status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1759                 if (status)
1760                         return ERR_PTR(status);
1761         }
1762
1763         /* Get a volume representation */
1764         server = nfs_create_server(mount_info->parsed, mount_info->mntfh);
1765         if (IS_ERR(server))
1766                 return ERR_CAST(server);
1767
1768         return nfs_fs_mount_common(&nfs_fs_type, server, flags, dev_name, mount_info);
1769 }
1770
1771 /*
1772  * Split "dev_name" into "hostname:export_path".
1773  *
1774  * The leftmost colon demarks the split between the server's hostname
1775  * and the export path.  If the hostname starts with a left square
1776  * bracket, then it may contain colons.
1777  *
1778  * Note: caller frees hostname and export path, even on error.
1779  */
1780 static int nfs_parse_devname(const char *dev_name,
1781                              char **hostname, size_t maxnamlen,
1782                              char **export_path, size_t maxpathlen)
1783 {
1784         size_t len;
1785         char *end;
1786
1787         /* Is the host name protected with square brakcets? */
1788         if (*dev_name == '[') {
1789                 end = strchr(++dev_name, ']');
1790                 if (end == NULL || end[1] != ':')
1791                         goto out_bad_devname;
1792
1793                 len = end - dev_name;
1794                 end++;
1795         } else {
1796                 char *comma;
1797
1798                 end = strchr(dev_name, ':');
1799                 if (end == NULL)
1800                         goto out_bad_devname;
1801                 len = end - dev_name;
1802
1803                 /* kill possible hostname list: not supported */
1804                 comma = strchr(dev_name, ',');
1805                 if (comma != NULL && comma < end)
1806                         *comma = 0;
1807         }
1808
1809         if (len > maxnamlen)
1810                 goto out_hostname;
1811
1812         /* N.B. caller will free nfs_server.hostname in all cases */
1813         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1814         if (*hostname == NULL)
1815                 goto out_nomem;
1816         len = strlen(++end);
1817         if (len > maxpathlen)
1818                 goto out_path;
1819         *export_path = kstrndup(end, len, GFP_KERNEL);
1820         if (!*export_path)
1821                 goto out_nomem;
1822
1823         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1824         return 0;
1825
1826 out_bad_devname:
1827         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1828         return -EINVAL;
1829
1830 out_nomem:
1831         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1832         return -ENOMEM;
1833
1834 out_hostname:
1835         dfprintk(MOUNT, "NFS: server hostname too long\n");
1836         return -ENAMETOOLONG;
1837
1838 out_path:
1839         dfprintk(MOUNT, "NFS: export pathname too long\n");
1840         return -ENAMETOOLONG;
1841 }
1842
1843 /*
1844  * Validate the NFS2/NFS3 mount data
1845  * - fills in the mount root filehandle
1846  *
1847  * For option strings, user space handles the following behaviors:
1848  *
1849  * + DNS: mapping server host name to IP address ("addr=" option)
1850  *
1851  * + failure mode: how to behave if a mount request can't be handled
1852  *   immediately ("fg/bg" option)
1853  *
1854  * + retry: how often to retry a mount request ("retry=" option)
1855  *
1856  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1857  *   mountproto=tcp after mountproto=udp, and so on
1858  */
1859 static int nfs23_validate_mount_data(void *options,
1860                                      struct nfs_parsed_mount_data *args,
1861                                      struct nfs_fh *mntfh,
1862                                      const char *dev_name)
1863 {
1864         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1865         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1866
1867         if (data == NULL)
1868                 goto out_no_data;
1869
1870         args->version = NFS_DEFAULT_VERSION;
1871         switch (data->version) {
1872         case 1:
1873                 data->namlen = 0;
1874         case 2:
1875                 data->bsize = 0;
1876         case 3:
1877                 if (data->flags & NFS_MOUNT_VER3)
1878                         goto out_no_v3;
1879                 data->root.size = NFS2_FHSIZE;
1880                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1881         case 4:
1882                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1883                         goto out_no_sec;
1884         case 5:
1885                 memset(data->context, 0, sizeof(data->context));
1886         case 6:
1887                 if (data->flags & NFS_MOUNT_VER3) {
1888                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1889                                 goto out_invalid_fh;
1890                         mntfh->size = data->root.size;
1891                         args->version = 3;
1892                 } else {
1893                         mntfh->size = NFS2_FHSIZE;
1894                         args->version = 2;
1895                 }
1896
1897
1898                 memcpy(mntfh->data, data->root.data, mntfh->size);
1899                 if (mntfh->size < sizeof(mntfh->data))
1900                         memset(mntfh->data + mntfh->size, 0,
1901                                sizeof(mntfh->data) - mntfh->size);
1902
1903                 /*
1904                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1905                  * can deal with.
1906                  */
1907                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1908                 args->flags             |= NFS_MOUNT_LEGACY_INTERFACE;
1909                 args->rsize             = data->rsize;
1910                 args->wsize             = data->wsize;
1911                 args->timeo             = data->timeo;
1912                 args->retrans           = data->retrans;
1913                 args->acregmin          = data->acregmin;
1914                 args->acregmax          = data->acregmax;
1915                 args->acdirmin          = data->acdirmin;
1916                 args->acdirmax          = data->acdirmax;
1917                 args->need_mount        = false;
1918
1919                 memcpy(sap, &data->addr, sizeof(data->addr));
1920                 args->nfs_server.addrlen = sizeof(data->addr);
1921                 if (!nfs_verify_server_address(sap))
1922                         goto out_no_address;
1923
1924                 if (!(data->flags & NFS_MOUNT_TCP))
1925                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1926                 /* N.B. caller will free nfs_server.hostname in all cases */
1927                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1928                 args->namlen            = data->namlen;
1929                 args->bsize             = data->bsize;
1930
1931                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1932                         args->auth_flavors[0] = data->pseudoflavor;
1933                 if (!args->nfs_server.hostname)
1934                         goto out_nomem;
1935
1936                 if (!(data->flags & NFS_MOUNT_NONLM))
1937                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1938                                          NFS_MOUNT_LOCAL_FCNTL);
1939                 else
1940                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1941                                         NFS_MOUNT_LOCAL_FCNTL);
1942                 /*
1943                  * The legacy version 6 binary mount data from userspace has a
1944                  * field used only to transport selinux information into the
1945                  * the kernel.  To continue to support that functionality we
1946                  * have a touch of selinux knowledge here in the NFS code. The
1947                  * userspace code converted context=blah to just blah so we are
1948                  * converting back to the full string selinux understands.
1949                  */
1950                 if (data->context[0]){
1951 #ifdef CONFIG_SECURITY_SELINUX
1952                         int rc;
1953                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1954                         if (!opts_str)
1955                                 return -ENOMEM;
1956                         strcpy(opts_str, "context=");
1957                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1958                         strcat(opts_str, &data->context[0]);
1959                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1960                         kfree(opts_str);
1961                         if (rc)
1962                                 return rc;
1963 #else
1964                         return -EINVAL;
1965 #endif
1966                 }
1967
1968                 break;
1969         default:
1970                 return NFS_TEXT_DATA;
1971         }
1972
1973 #ifndef CONFIG_NFS_V3
1974         if (args->version == 3)
1975                 goto out_v3_not_compiled;
1976 #endif /* !CONFIG_NFS_V3 */
1977
1978         return 0;
1979
1980 out_no_data:
1981         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1982         return -EINVAL;
1983
1984 out_no_v3:
1985         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1986                  data->version);
1987         return -EINVAL;
1988
1989 out_no_sec:
1990         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1991         return -EINVAL;
1992
1993 #ifndef CONFIG_NFS_V3
1994 out_v3_not_compiled:
1995         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1996         return -EPROTONOSUPPORT;
1997 #endif /* !CONFIG_NFS_V3 */
1998
1999 out_nomem:
2000         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2001         return -ENOMEM;
2002
2003 out_no_address:
2004         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2005         return -EINVAL;
2006
2007 out_invalid_fh:
2008         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2009         return -EINVAL;
2010 }
2011
2012 #ifdef CONFIG_NFS_V4
2013 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2014                                    void *options,
2015                                    struct nfs_parsed_mount_data *args,
2016                                    struct nfs_fh *mntfh,
2017                                    const char *dev_name)
2018 {
2019         if (fs_type == &nfs_fs_type)
2020                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2021         return nfs4_validate_mount_data(options, args, dev_name);
2022 }
2023 #else
2024 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2025                                    void *options,
2026                                    struct nfs_parsed_mount_data *args,
2027                                    struct nfs_fh *mntfh,
2028                                    const char *dev_name)
2029 {
2030         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2031 }
2032 #endif
2033
2034 static int nfs_validate_text_mount_data(void *options,
2035                                         struct nfs_parsed_mount_data *args,
2036                                         const char *dev_name)
2037 {
2038         int port = 0;
2039         int max_namelen = PAGE_SIZE;
2040         int max_pathlen = NFS_MAXPATHLEN;
2041         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2042
2043         if (nfs_parse_mount_options((char *)options, args) == 0)
2044                 return -EINVAL;
2045
2046         if (!nfs_verify_server_address(sap))
2047                 goto out_no_address;
2048
2049         if (args->version == 4) {
2050 #ifdef CONFIG_NFS_V4
2051                 port = NFS_PORT;
2052                 max_namelen = NFS4_MAXNAMLEN;
2053                 max_pathlen = NFS4_MAXPATHLEN;
2054                 nfs_validate_transport_protocol(args);
2055                 nfs4_validate_mount_flags(args);
2056 #else
2057                 goto out_v4_not_compiled;
2058 #endif /* CONFIG_NFS_V4 */
2059         } else
2060                 nfs_set_mount_transport_protocol(args);
2061
2062         nfs_set_port(sap, &args->nfs_server.port, port);
2063
2064         if (args->auth_flavor_len > 1)
2065                 goto out_bad_auth;
2066
2067         return nfs_parse_devname(dev_name,
2068                                    &args->nfs_server.hostname,
2069                                    max_namelen,
2070                                    &args->nfs_server.export_path,
2071                                    max_pathlen);
2072
2073 #ifndef CONFIG_NFS_V4
2074 out_v4_not_compiled:
2075         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2076         return -EPROTONOSUPPORT;
2077 #endif /* !CONFIG_NFS_V4 */
2078
2079 out_no_address:
2080         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2081         return -EINVAL;
2082
2083 out_bad_auth:
2084         dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2085         return -EINVAL;
2086 }
2087
2088 static int
2089 nfs_compare_remount_data(struct nfs_server *nfss,
2090                          struct nfs_parsed_mount_data *data)
2091 {
2092         if (data->flags != nfss->flags ||
2093             data->rsize != nfss->rsize ||
2094             data->wsize != nfss->wsize ||
2095             data->retrans != nfss->client->cl_timeout->to_retries ||
2096             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2097             data->acregmin != nfss->acregmin / HZ ||
2098             data->acregmax != nfss->acregmax / HZ ||
2099             data->acdirmin != nfss->acdirmin / HZ ||
2100             data->acdirmax != nfss->acdirmax / HZ ||
2101             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2102             data->nfs_server.port != nfss->port ||
2103             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2104             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2105                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2106                 return -EINVAL;
2107
2108         return 0;
2109 }
2110
2111 static int
2112 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2113 {
2114         int error;
2115         struct nfs_server *nfss = sb->s_fs_info;
2116         struct nfs_parsed_mount_data *data;
2117         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2118         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2119         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2120
2121         /*
2122          * Userspace mount programs that send binary options generally send
2123          * them populated with default values. We have no way to know which
2124          * ones were explicitly specified. Fall back to legacy behavior and
2125          * just return success.
2126          */
2127         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2128             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2129                                            options->version <= 6))))
2130                 return 0;
2131
2132         data = kzalloc(sizeof(*data), GFP_KERNEL);
2133         if (data == NULL)
2134                 return -ENOMEM;
2135
2136         /* fill out struct with values from existing mount */
2137         data->flags = nfss->flags;
2138         data->rsize = nfss->rsize;
2139         data->wsize = nfss->wsize;
2140         data->retrans = nfss->client->cl_timeout->to_retries;
2141         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2142         data->acregmin = nfss->acregmin / HZ;
2143         data->acregmax = nfss->acregmax / HZ;
2144         data->acdirmin = nfss->acdirmin / HZ;
2145         data->acdirmax = nfss->acdirmax / HZ;
2146         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2147         data->nfs_server.port = nfss->port;
2148         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2149         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2150                 data->nfs_server.addrlen);
2151
2152         /* overwrite those values with any that were specified */
2153         error = nfs_parse_mount_options((char *)options, data);
2154         if (error < 0)
2155                 goto out;
2156
2157         /*
2158          * noac is a special case. It implies -o sync, but that's not
2159          * necessarily reflected in the mtab options. do_remount_sb
2160          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2161          * remount options, so we have to explicitly reset it.
2162          */
2163         if (data->flags & NFS_MOUNT_NOAC)
2164                 *flags |= MS_SYNCHRONOUS;
2165
2166         /* compare new mount options with old ones */
2167         error = nfs_compare_remount_data(nfss, data);
2168 out:
2169         kfree(data);
2170         return error;
2171 }
2172
2173 /*
2174  * Initialise the common bits of the superblock
2175  */
2176 static inline void nfs_initialise_sb(struct super_block *sb)
2177 {
2178         struct nfs_server *server = NFS_SB(sb);
2179
2180         sb->s_magic = NFS_SUPER_MAGIC;
2181
2182         /* We probably want something more informative here */
2183         snprintf(sb->s_id, sizeof(sb->s_id),
2184                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2185
2186         if (sb->s_blocksize == 0)
2187                 sb->s_blocksize = nfs_block_bits(server->wsize,
2188                                                  &sb->s_blocksize_bits);
2189
2190         sb->s_bdi = &server->backing_dev_info;
2191
2192         nfs_super_set_maxbytes(sb, server->maxfilesize);
2193 }
2194
2195 /*
2196  * Finish setting up an NFS2/3 superblock
2197  */
2198 static void nfs_fill_super(struct super_block *sb,
2199                            struct nfs_mount_info *mount_info)
2200 {
2201         struct nfs_parsed_mount_data *data = mount_info->parsed;
2202         struct nfs_server *server = NFS_SB(sb);
2203
2204         sb->s_blocksize_bits = 0;
2205         sb->s_blocksize = 0;
2206         if (data->bsize)
2207                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2208
2209         if (server->nfs_client->rpc_ops->version == 3) {
2210                 /* The VFS shouldn't apply the umask to mode bits. We will do
2211                  * so ourselves when necessary.
2212                  */
2213                 sb->s_flags |= MS_POSIXACL;
2214                 sb->s_time_gran = 1;
2215         }
2216
2217         sb->s_op = &nfs_sops;
2218         nfs_initialise_sb(sb);
2219 }
2220
2221 /*
2222  * Finish setting up a cloned NFS2/3 superblock
2223  */
2224 static void nfs_clone_super(struct super_block *sb,
2225                             struct nfs_mount_info *mount_info)
2226 {
2227         const struct super_block *old_sb = mount_info->cloned->sb;
2228         struct nfs_server *server = NFS_SB(sb);
2229
2230         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2231         sb->s_blocksize = old_sb->s_blocksize;
2232         sb->s_maxbytes = old_sb->s_maxbytes;
2233
2234         if (server->nfs_client->rpc_ops->version == 3) {
2235                 /* The VFS shouldn't apply the umask to mode bits. We will do
2236                  * so ourselves when necessary.
2237                  */
2238                 sb->s_flags |= MS_POSIXACL;
2239                 sb->s_time_gran = 1;
2240         }
2241
2242         sb->s_op = old_sb->s_op;
2243         nfs_initialise_sb(sb);
2244 }
2245
2246 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2247 {
2248         const struct nfs_server *a = s->s_fs_info;
2249         const struct rpc_clnt *clnt_a = a->client;
2250         const struct rpc_clnt *clnt_b = b->client;
2251
2252         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2253                 goto Ebusy;
2254         if (a->nfs_client != b->nfs_client)
2255                 goto Ebusy;
2256         if (a->flags != b->flags)
2257                 goto Ebusy;
2258         if (a->wsize != b->wsize)
2259                 goto Ebusy;
2260         if (a->rsize != b->rsize)
2261                 goto Ebusy;
2262         if (a->acregmin != b->acregmin)
2263                 goto Ebusy;
2264         if (a->acregmax != b->acregmax)
2265                 goto Ebusy;
2266         if (a->acdirmin != b->acdirmin)
2267                 goto Ebusy;
2268         if (a->acdirmax != b->acdirmax)
2269                 goto Ebusy;
2270         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2271                 goto Ebusy;
2272         return 1;
2273 Ebusy:
2274         return 0;
2275 }
2276
2277 struct nfs_sb_mountdata {
2278         struct nfs_server *server;
2279         int mntflags;
2280 };
2281
2282 static int nfs_set_super(struct super_block *s, void *data)
2283 {
2284         struct nfs_sb_mountdata *sb_mntdata = data;
2285         struct nfs_server *server = sb_mntdata->server;
2286         int ret;
2287
2288         s->s_flags = sb_mntdata->mntflags;
2289         s->s_fs_info = server;
2290         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2291         ret = set_anon_super(s, server);
2292         if (ret == 0)
2293                 server->s_dev = s->s_dev;
2294         return ret;
2295 }
2296
2297 static int nfs_compare_super_address(struct nfs_server *server1,
2298                                      struct nfs_server *server2)
2299 {
2300         struct sockaddr *sap1, *sap2;
2301
2302         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2303         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2304
2305         if (sap1->sa_family != sap2->sa_family)
2306                 return 0;
2307
2308         switch (sap1->sa_family) {
2309         case AF_INET: {
2310                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2311                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2312                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2313                         return 0;
2314                 if (sin1->sin_port != sin2->sin_port)
2315                         return 0;
2316                 break;
2317         }
2318         case AF_INET6: {
2319                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2320                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2321                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2322                         return 0;
2323                 if (sin1->sin6_port != sin2->sin6_port)
2324                         return 0;
2325                 break;
2326         }
2327         default:
2328                 return 0;
2329         }
2330
2331         return 1;
2332 }
2333
2334 static int nfs_compare_super(struct super_block *sb, void *data)
2335 {
2336         struct nfs_sb_mountdata *sb_mntdata = data;
2337         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2338         int mntflags = sb_mntdata->mntflags;
2339
2340         if (!nfs_compare_super_address(old, server))
2341                 return 0;
2342         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2343         if (old->flags & NFS_MOUNT_UNSHARED)
2344                 return 0;
2345         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2346                 return 0;
2347         return nfs_compare_mount_options(sb, server, mntflags);
2348 }
2349
2350 #ifdef CONFIG_NFS_FSCACHE
2351 static void nfs_get_cache_cookie(struct super_block *sb,
2352                                  struct nfs_parsed_mount_data *parsed,
2353                                  struct nfs_clone_mount *cloned)
2354 {
2355         char *uniq = NULL;
2356         int ulen = 0;
2357
2358         if (parsed && parsed->fscache_uniq) {
2359                 uniq = parsed->fscache_uniq;
2360                 ulen = strlen(parsed->fscache_uniq);
2361         } else if (cloned) {
2362                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2363                 if (mnt_s->fscache_key) {
2364                         uniq = mnt_s->fscache_key->key.uniquifier;
2365                         ulen = mnt_s->fscache_key->key.uniq_len;
2366                 };
2367         }
2368
2369         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2370 }
2371 #else
2372 static void nfs_get_cache_cookie(struct super_block *sb,
2373                                  struct nfs_parsed_mount_data *parsed,
2374                                  struct nfs_clone_mount *cloned)
2375 {
2376 }
2377 #endif
2378
2379 static int nfs_bdi_register(struct nfs_server *server)
2380 {
2381         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2382 }
2383
2384 static int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2385                                struct nfs_mount_info *mount_info)
2386 {
2387         return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2388 }
2389
2390 static int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2391                                  struct nfs_mount_info *mount_info)
2392 {
2393         /* clone any lsm security options from the parent to the new sb */
2394         security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2395         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2396                 return -ESTALE;
2397         return 0;
2398 }
2399
2400 static struct dentry *nfs_fs_mount_common(struct file_system_type *fs_type,
2401                                           struct nfs_server *server,
2402                                           int flags, const char *dev_name,
2403                                           struct nfs_mount_info *mount_info)
2404 {
2405         struct super_block *s;
2406         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2407         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2408         struct nfs_sb_mountdata sb_mntdata = {
2409                 .mntflags = flags,
2410                 .server = server,
2411         };
2412         int error;
2413
2414         if (server->flags & NFS_MOUNT_UNSHARED)
2415                 compare_super = NULL;
2416
2417         /* -o noac implies -o sync */
2418         if (server->flags & NFS_MOUNT_NOAC)
2419                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2420
2421         /* Get a superblock - note that we may end up sharing one that already exists */
2422         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2423         if (IS_ERR(s)) {
2424                 mntroot = ERR_CAST(s);
2425                 goto out_err_nosb;
2426         }
2427
2428         if (s->s_fs_info != server) {
2429                 nfs_free_server(server);
2430                 server = NULL;
2431         } else {
2432                 error = nfs_bdi_register(server);
2433                 if (error) {
2434                         mntroot = ERR_PTR(error);
2435                         goto error_splat_bdi;
2436                 }
2437         }
2438
2439         if (!s->s_root) {
2440                 /* initial superblock/root creation */
2441                 mount_info->fill_super(s, mount_info);
2442                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2443         }
2444
2445         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2446         if (IS_ERR(mntroot))
2447                 goto error_splat_super;
2448
2449         error = mount_info->set_security(s, mntroot, mount_info);
2450         if (error)
2451                 goto error_splat_root;
2452
2453         s->s_flags |= MS_ACTIVE;
2454
2455 out:
2456         return mntroot;
2457
2458 out_err_nosb:
2459         nfs_free_server(server);
2460         goto out;
2461
2462 error_splat_root:
2463         dput(mntroot);
2464         mntroot = ERR_PTR(error);
2465 error_splat_super:
2466         if (server && !s->s_root)
2467                 bdi_unregister(&server->backing_dev_info);
2468 error_splat_bdi:
2469         deactivate_locked_super(s);
2470         goto out;
2471 }
2472
2473 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2474         int flags, const char *dev_name, void *raw_data)
2475 {
2476         struct nfs_mount_info mount_info = {
2477                 .fill_super = nfs_fill_super,
2478                 .set_security = nfs_set_sb_security,
2479         };
2480         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2481         int error;
2482
2483         mount_info.parsed = nfs_alloc_parsed_mount_data();
2484         mount_info.mntfh = nfs_alloc_fhandle();
2485         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2486                 goto out;
2487
2488         /* Validate the mount data */
2489         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2490         if (error == NFS_TEXT_DATA)
2491                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2492         if (error < 0) {
2493                 mntroot = ERR_PTR(error);
2494                 goto out;
2495         }
2496
2497 #ifdef CONFIG_NFS_V4
2498         if (mount_info.parsed->version == 4)
2499                 mntroot = nfs4_try_mount(flags, dev_name, &mount_info);
2500         else
2501 #endif  /* CONFIG_NFS_V4 */
2502                 mntroot = nfs_try_mount(flags, dev_name, &mount_info);
2503
2504 out:
2505         nfs_free_parsed_mount_data(mount_info.parsed);
2506         nfs_free_fhandle(mount_info.mntfh);
2507         return mntroot;
2508 }
2509
2510 /*
2511  * Ensure that we unregister the bdi before kill_anon_super
2512  * releases the device name
2513  */
2514 static void nfs_put_super(struct super_block *s)
2515 {
2516         struct nfs_server *server = NFS_SB(s);
2517
2518         bdi_unregister(&server->backing_dev_info);
2519 }
2520
2521 /*
2522  * Destroy an NFS2/3 superblock
2523  */
2524 static void nfs_kill_super(struct super_block *s)
2525 {
2526         struct nfs_server *server = NFS_SB(s);
2527
2528         kill_anon_super(s);
2529         nfs_fscache_release_super_cookie(s);
2530         nfs_free_server(server);
2531 }
2532
2533 /*
2534  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2535  */
2536 static struct dentry *
2537 nfs_xdev_mount_common(struct file_system_type *fs_type, int flags,
2538                 const char *dev_name, struct nfs_mount_info *mount_info)
2539 {
2540         struct nfs_clone_mount *data = mount_info->cloned;
2541         struct nfs_server *server;
2542         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2543         int error;
2544
2545         dprintk("--> nfs_xdev_mount_common()\n");
2546
2547         mount_info->mntfh = data->fh;
2548
2549         /* create a new volume representation */
2550         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2551         if (IS_ERR(server)) {
2552                 error = PTR_ERR(server);
2553                 goto out_err;
2554         }
2555
2556         mntroot = nfs_fs_mount_common(fs_type, server, flags, dev_name, mount_info);
2557         dprintk("<-- nfs_xdev_mount_common() = 0\n");
2558 out:
2559         return mntroot;
2560
2561 out_err:
2562         dprintk("<-- nfs_xdev_mount_common() = %d [error]\n", error);
2563         goto out;
2564 }
2565
2566 /*
2567  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2568  */
2569 static struct dentry *
2570 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2571                 const char *dev_name, void *raw_data)
2572 {
2573         struct nfs_mount_info mount_info = {
2574                 .fill_super = nfs_clone_super,
2575                 .set_security = nfs_clone_sb_security,
2576                 .cloned   = raw_data,
2577         };
2578         return nfs_xdev_mount_common(&nfs_fs_type, flags, dev_name, &mount_info);
2579 }
2580
2581 #ifdef CONFIG_NFS_V4
2582
2583 /*
2584  * Finish setting up a cloned NFS4 superblock
2585  */
2586 static void nfs4_clone_super(struct super_block *sb,
2587                              struct nfs_mount_info *mount_info)
2588 {
2589         const struct super_block *old_sb = mount_info->cloned->sb;
2590         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2591         sb->s_blocksize = old_sb->s_blocksize;
2592         sb->s_maxbytes = old_sb->s_maxbytes;
2593         sb->s_time_gran = 1;
2594         sb->s_op = old_sb->s_op;
2595         /*
2596          * The VFS shouldn't apply the umask to mode bits. We will do
2597          * so ourselves when necessary.
2598          */
2599         sb->s_flags  |= MS_POSIXACL;
2600         sb->s_xattr  = old_sb->s_xattr;
2601         nfs_initialise_sb(sb);
2602 }
2603
2604 /*
2605  * Set up an NFS4 superblock
2606  */
2607 static void nfs4_fill_super(struct super_block *sb,
2608                             struct nfs_mount_info *mount_info)
2609 {
2610         sb->s_time_gran = 1;
2611         sb->s_op = &nfs4_sops;
2612         /*
2613          * The VFS shouldn't apply the umask to mode bits. We will do
2614          * so ourselves when necessary.
2615          */
2616         sb->s_flags  |= MS_POSIXACL;
2617         sb->s_xattr = nfs4_xattr_handlers;
2618         nfs_initialise_sb(sb);
2619 }
2620
2621 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2622 {
2623         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2624                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2625 }
2626
2627 /*
2628  * Validate NFSv4 mount options
2629  */
2630 static int nfs4_validate_mount_data(void *options,
2631                                     struct nfs_parsed_mount_data *args,
2632                                     const char *dev_name)
2633 {
2634         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2635         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2636         char *c;
2637
2638         if (data == NULL)
2639                 goto out_no_data;
2640
2641         args->version = 4;
2642
2643         switch (data->version) {
2644         case 1:
2645                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2646                         goto out_no_address;
2647                 if (data->host_addrlen == 0)
2648                         goto out_no_address;
2649                 args->nfs_server.addrlen = data->host_addrlen;
2650                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2651                         return -EFAULT;
2652                 if (!nfs_verify_server_address(sap))
2653                         goto out_no_address;
2654
2655                 if (data->auth_flavourlen) {
2656                         if (data->auth_flavourlen > 1)
2657                                 goto out_inval_auth;
2658                         if (copy_from_user(&args->auth_flavors[0],
2659                                            data->auth_flavours,
2660                                            sizeof(args->auth_flavors[0])))
2661                                 return -EFAULT;
2662                 }
2663
2664                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2665                 if (IS_ERR(c))
2666                         return PTR_ERR(c);
2667                 args->nfs_server.hostname = c;
2668
2669                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2670                 if (IS_ERR(c))
2671                         return PTR_ERR(c);
2672                 args->nfs_server.export_path = c;
2673                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2674
2675                 c = strndup_user(data->client_addr.data, 16);
2676                 if (IS_ERR(c))
2677                         return PTR_ERR(c);
2678                 args->client_address = c;
2679
2680                 /*
2681                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2682                  * can deal with.
2683                  */
2684
2685                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2686                 args->rsize     = data->rsize;
2687                 args->wsize     = data->wsize;
2688                 args->timeo     = data->timeo;
2689                 args->retrans   = data->retrans;
2690                 args->acregmin  = data->acregmin;
2691                 args->acregmax  = data->acregmax;
2692                 args->acdirmin  = data->acdirmin;
2693                 args->acdirmax  = data->acdirmax;
2694                 args->nfs_server.protocol = data->proto;
2695                 nfs_validate_transport_protocol(args);
2696
2697                 break;
2698         default:
2699                 return NFS_TEXT_DATA;
2700         }
2701
2702         return 0;
2703
2704 out_no_data:
2705         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2706         return -EINVAL;
2707
2708 out_inval_auth:
2709         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2710                  data->auth_flavourlen);
2711         return -EINVAL;
2712
2713 out_no_address:
2714         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2715         return -EINVAL;
2716 }
2717
2718 /*
2719  * Get the superblock for the NFS4 root partition
2720  */
2721 static struct dentry *
2722 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2723                   const char *dev_name, void *info)
2724 {
2725         struct nfs_mount_info *mount_info = info;
2726         struct nfs_server *server;
2727         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2728
2729         mount_info->fill_super = nfs4_fill_super;
2730         mount_info->set_security = nfs_set_sb_security;
2731
2732         /* Get a volume representation */
2733         server = nfs4_create_server(mount_info->parsed, mount_info->mntfh);
2734         if (IS_ERR(server)) {
2735                 mntroot = ERR_CAST(server);
2736                 goto out;
2737         }
2738
2739         mntroot = nfs_fs_mount_common(fs_type, server, flags, dev_name, mount_info);
2740
2741 out:
2742         return mntroot;
2743 }
2744
2745 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2746                 int flags, void *data, const char *hostname)
2747 {
2748         struct vfsmount *root_mnt;
2749         char *root_devname;
2750         size_t len;
2751
2752         len = strlen(hostname) + 5;
2753         root_devname = kmalloc(len, GFP_KERNEL);
2754         if (root_devname == NULL)
2755                 return ERR_PTR(-ENOMEM);
2756         /* Does hostname needs to be enclosed in brackets? */
2757         if (strchr(hostname, ':'))
2758                 snprintf(root_devname, len, "[%s]:/", hostname);
2759         else
2760                 snprintf(root_devname, len, "%s:/", hostname);
2761         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2762         kfree(root_devname);
2763         return root_mnt;
2764 }
2765
2766 struct nfs_referral_count {
2767         struct list_head list;
2768         const struct task_struct *task;
2769         unsigned int referral_count;
2770 };
2771
2772 static LIST_HEAD(nfs_referral_count_list);
2773 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2774
2775 static struct nfs_referral_count *nfs_find_referral_count(void)
2776 {
2777         struct nfs_referral_count *p;
2778
2779         list_for_each_entry(p, &nfs_referral_count_list, list) {
2780                 if (p->task == current)
2781                         return p;
2782         }
2783         return NULL;
2784 }
2785
2786 #define NFS_MAX_NESTED_REFERRALS 2
2787
2788 static int nfs_referral_loop_protect(void)
2789 {
2790         struct nfs_referral_count *p, *new;
2791         int ret = -ENOMEM;
2792
2793         new = kmalloc(sizeof(*new), GFP_KERNEL);
2794         if (!new)
2795                 goto out;
2796         new->task = current;
2797         new->referral_count = 1;
2798
2799         ret = 0;
2800         spin_lock(&nfs_referral_count_list_lock);
2801         p = nfs_find_referral_count();
2802         if (p != NULL) {
2803                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2804                         ret = -ELOOP;
2805                 else
2806                         p->referral_count++;
2807         } else {
2808                 list_add(&new->list, &nfs_referral_count_list);
2809                 new = NULL;
2810         }
2811         spin_unlock(&nfs_referral_count_list_lock);
2812         kfree(new);
2813 out:
2814         return ret;
2815 }
2816
2817 static void nfs_referral_loop_unprotect(void)
2818 {
2819         struct nfs_referral_count *p;
2820
2821         spin_lock(&nfs_referral_count_list_lock);
2822         p = nfs_find_referral_count();
2823         p->referral_count--;
2824         if (p->referral_count == 0)
2825                 list_del(&p->list);
2826         else
2827                 p = NULL;
2828         spin_unlock(&nfs_referral_count_list_lock);
2829         kfree(p);
2830 }
2831
2832 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2833                 const char *export_path)
2834 {
2835         struct dentry *dentry;
2836         int err;
2837
2838         if (IS_ERR(root_mnt))
2839                 return ERR_CAST(root_mnt);
2840
2841         err = nfs_referral_loop_protect();
2842         if (err) {
2843                 mntput(root_mnt);
2844                 return ERR_PTR(err);
2845         }
2846
2847         dentry = mount_subtree(root_mnt, export_path);
2848         nfs_referral_loop_unprotect();
2849
2850         return dentry;
2851 }
2852
2853 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2854                          struct nfs_mount_info *mount_info)
2855 {
2856         char *export_path;
2857         struct vfsmount *root_mnt;
2858         struct dentry *res;
2859         struct nfs_parsed_mount_data *data = mount_info->parsed;
2860
2861         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2862
2863         export_path = data->nfs_server.export_path;
2864         data->nfs_server.export_path = "/";
2865         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
2866                         data->nfs_server.hostname);
2867         data->nfs_server.export_path = export_path;
2868
2869         res = nfs_follow_remote_path(root_mnt, export_path);
2870
2871         dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2872                         IS_ERR(res) ? PTR_ERR(res) : 0,
2873                         IS_ERR(res) ? " [error]" : "");
2874         return res;
2875 }
2876
2877 static void nfs4_kill_super(struct super_block *sb)
2878 {
2879         struct nfs_server *server = NFS_SB(sb);
2880
2881         dprintk("--> %s\n", __func__);
2882         nfs_super_return_all_delegations(sb);
2883         kill_anon_super(sb);
2884         nfs_fscache_release_super_cookie(sb);
2885         nfs_free_server(server);
2886         dprintk("<-- %s\n", __func__);
2887 }
2888
2889 /*
2890  * Clone an NFS4 server record on xdev traversal (FSID-change)
2891  */
2892 static struct dentry *
2893 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2894                  const char *dev_name, void *raw_data)
2895 {
2896         struct nfs_mount_info mount_info = {
2897                 .fill_super = nfs4_clone_super,
2898                 .set_security = nfs_clone_sb_security,
2899                 .cloned = raw_data,
2900         };
2901         return nfs_xdev_mount_common(&nfs4_fs_type, flags, dev_name, &mount_info);
2902 }
2903
2904 static struct dentry *
2905 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2906                            const char *dev_name, void *raw_data)
2907 {
2908         struct nfs_mount_info mount_info = {
2909                 .fill_super = nfs4_fill_super,
2910                 .set_security = nfs_clone_sb_security,
2911                 .cloned = raw_data,
2912         };
2913         struct nfs_server *server;
2914         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2915
2916         dprintk("--> nfs4_referral_get_sb()\n");
2917
2918         mount_info.mntfh = nfs_alloc_fhandle();
2919         if (mount_info.cloned == NULL || mount_info.mntfh == NULL)
2920                 goto out;
2921
2922         /* create a new volume representation */
2923         server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
2924         if (IS_ERR(server)) {
2925                 mntroot = ERR_CAST(server);
2926                 goto out;
2927         }
2928
2929         mntroot = nfs_fs_mount_common(&nfs4_fs_type, server, flags, dev_name, &mount_info);
2930 out:
2931         nfs_free_fhandle(mount_info.mntfh);
2932         return mntroot;
2933 }
2934
2935 /*
2936  * Create an NFS4 server record on referral traversal
2937  */
2938 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
2939                 int flags, const char *dev_name, void *raw_data)
2940 {
2941         struct nfs_clone_mount *data = raw_data;
2942         char *export_path;
2943         struct vfsmount *root_mnt;
2944         struct dentry *res;
2945
2946         dprintk("--> nfs4_referral_mount()\n");
2947
2948         export_path = data->mnt_path;
2949         data->mnt_path = "/";
2950
2951         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2952                         flags, data, data->hostname);
2953         data->mnt_path = export_path;
2954
2955         res = nfs_follow_remote_path(root_mnt, export_path);
2956         dprintk("<-- nfs4_referral_mount() = %ld%s\n",
2957                         IS_ERR(res) ? PTR_ERR(res) : 0,
2958                         IS_ERR(res) ? " [error]" : "");
2959         return res;
2960 }
2961
2962 #endif /* CONFIG_NFS_V4 */