fs/nfs/super.c

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