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   1 /*
   2  *  linux/fs/nfs/super.c
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  nfs superblock handling functions
   7  *
   8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
   9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
  10  *
  11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
  12  *  J.S.Peatfield@damtp.cam.ac.uk
  13  *
  14  *  Split from inode.c by David Howells <dhowells@redhat.com>
  15  *
  16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
  17  *   particular server are held in the same superblock
  18  * - NFS superblocks can have several effective roots to the dentry tree
  19  * - directory type roots are spliced into the tree when a path from one root reaches the root
  20  *   of another (see nfs_lookup())
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/time.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mm.h>
  29 #include <linux/string.h>
  30 #include <linux/stat.h>
  31 #include <linux/errno.h>
  32 #include <linux/unistd.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/stats.h>
  35 #include <linux/sunrpc/metrics.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/sunrpc/xprtrdma.h>
  38 #include <linux/nfs_fs.h>
  39 #include <linux/nfs_mount.h>
  40 #include <linux/nfs4_mount.h>
  41 #include <linux/lockd/bind.h>
  42 #include <linux/smp_lock.h>
  43 #include <linux/seq_file.h>
  44 #include <linux/mount.h>
  45 #include <linux/mnt_namespace.h>
  46 #include <linux/namei.h>
  47 #include <linux/nfs_idmap.h>
  48 #include <linux/vfs.h>
  49 #include <linux/inet.h>
  50 #include <linux/in6.h>
  51 #include <net/ipv6.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/nfs_xdr.h>
  54 #include <linux/magic.h>
  55 #include <linux/parser.h>
  56
  57 #include <asm/system.h>
  58 #include <asm/uaccess.h>
  59
  60 #include "nfs4_fs.h"
  61 #include "callback.h"
  62 #include "delegation.h"
  63 #include "iostat.h"
  64 #include "internal.h"
  65 #include "fscache.h"
  66
  67 #define NFSDBG_FACILITY         NFSDBG_VFS
  68
  69 enum {
  70         /* Mount options that take no arguments */
  71         Opt_soft, Opt_hard,
  72         Opt_posix, Opt_noposix,
  73         Opt_cto, Opt_nocto,
  74         Opt_ac, Opt_noac,
  75         Opt_lock, Opt_nolock,
  76         Opt_v2, Opt_v3,
  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_get_sb(struct file_system_type *fs_type,
 276         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 277 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 278         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 279 static int nfs4_xdev_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_referral_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_remote_referral_get_sb(struct file_system_type *fs_type,
 284         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 285 static void nfs4_kill_super(struct super_block *sb);
 286
 287 static struct file_system_type nfs4_fs_type = {
 288         .owner          = THIS_MODULE,
 289         .name           = "nfs4",
 290         .get_sb         = nfs4_get_sb,
 291         .kill_sb        = nfs4_kill_super,
 292         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 293 };
 294
 295 static struct file_system_type nfs4_remote_fs_type = {
 296         .owner          = THIS_MODULE,
 297         .name           = "nfs4",
 298         .get_sb         = nfs4_remote_get_sb,
 299         .kill_sb        = nfs4_kill_super,
 300         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 301 };
 302
 303 struct file_system_type nfs4_xdev_fs_type = {
 304         .owner          = THIS_MODULE,
 305         .name           = "nfs4",
 306         .get_sb         = nfs4_xdev_get_sb,
 307         .kill_sb        = nfs4_kill_super,
 308         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 309 };
 310
 311 static struct file_system_type nfs4_remote_referral_fs_type = {
 312         .owner          = THIS_MODULE,
 313         .name           = "nfs4",
 314         .get_sb         = nfs4_remote_referral_get_sb,
 315         .kill_sb        = nfs4_kill_super,
 316         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 317 };
 318
 319 struct file_system_type nfs4_referral_fs_type = {
 320         .owner          = THIS_MODULE,
 321         .name           = "nfs4",
 322         .get_sb         = nfs4_referral_get_sb,
 323         .kill_sb        = nfs4_kill_super,
 324         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 325 };
 326
 327 static const struct super_operations nfs4_sops = {
 328         .alloc_inode    = nfs_alloc_inode,
 329         .destroy_inode  = nfs_destroy_inode,
 330         .write_inode    = nfs_write_inode,
 331         .statfs         = nfs_statfs,
 332         .clear_inode    = nfs4_clear_inode,
 333         .umount_begin   = nfs_umount_begin,
 334         .show_options   = nfs_show_options,
 335         .show_stats     = nfs_show_stats,
 336         .remount_fs     = nfs_remount,
 337 };
 338 #endif
 339
 340 static struct shrinker acl_shrinker = {
 341         .shrink         = nfs_access_cache_shrinker,
 342         .seeks          = DEFAULT_SEEKS,
 343 };
 344
 345 /*
 346  * Register the NFS filesystems
 347  */
 348 int __init register_nfs_fs(void)
 349 {
 350         int ret;
 351
 352         ret = register_filesystem(&nfs_fs_type);
 353         if (ret < 0)
 354                 goto error_0;
 355
 356         ret = nfs_register_sysctl();
 357         if (ret < 0)
 358                 goto error_1;
 359 #ifdef CONFIG_NFS_V4
 360         ret = register_filesystem(&nfs4_fs_type);
 361         if (ret < 0)
 362                 goto error_2;
 363 #endif
 364         register_shrinker(&acl_shrinker);
 365         return 0;
 366
 367 #ifdef CONFIG_NFS_V4
 368 error_2:
 369         nfs_unregister_sysctl();
 370 #endif
 371 error_1:
 372         unregister_filesystem(&nfs_fs_type);
 373 error_0:
 374         return ret;
 375 }
 376
 377 /*
 378  * Unregister the NFS filesystems
 379  */
 380 void __exit unregister_nfs_fs(void)
 381 {
 382         unregister_shrinker(&acl_shrinker);
 383 #ifdef CONFIG_NFS_V4
 384         unregister_filesystem(&nfs4_fs_type);
 385 #endif
 386         nfs_unregister_sysctl();
 387         unregister_filesystem(&nfs_fs_type);
 388 }
 389
 390 void nfs_sb_active(struct super_block *sb)
 391 {
 392         struct nfs_server *server = NFS_SB(sb);
 393
 394         if (atomic_inc_return(&server->active) == 1)
 395                 atomic_inc(&sb->s_active);
 396 }
 397
 398 void nfs_sb_deactive(struct super_block *sb)
 399 {
 400         struct nfs_server *server = NFS_SB(sb);
 401
 402         if (atomic_dec_and_test(&server->active))
 403                 deactivate_super(sb);
 404 }
 405
 406 /*
 407  * Deliver file system statistics to userspace
 408  */
 409 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 410 {
 411         struct nfs_server *server = NFS_SB(dentry->d_sb);
 412         unsigned char blockbits;
 413         unsigned long blockres;
 414         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
 415         struct nfs_fattr fattr;
 416         struct nfs_fsstat res = {
 417                         .fattr = &fattr,
 418         };
 419         int error;
 420
 421         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
 422         if (error < 0)
 423                 goto out_err;
 424         buf->f_type = NFS_SUPER_MAGIC;
 425
 426         /*
 427          * Current versions of glibc do not correctly handle the
 428          * case where f_frsize != f_bsize.  Eventually we want to
 429          * report the value of wtmult in this field.
 430          */
 431         buf->f_frsize = dentry->d_sb->s_blocksize;
 432
 433         /*
 434          * On most *nix systems, f_blocks, f_bfree, and f_bavail
 435          * are reported in units of f_frsize.  Linux hasn't had
 436          * an f_frsize field in its statfs struct until recently,
 437          * thus historically Linux's sys_statfs reports these
 438          * fields in units of f_bsize.
 439          */
 440         buf->f_bsize = dentry->d_sb->s_blocksize;
 441         blockbits = dentry->d_sb->s_blocksize_bits;
 442         blockres = (1 << blockbits) - 1;
 443         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
 444         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
 445         buf->f_bavail = (res.abytes + blockres) >> blockbits;
 446
 447         buf->f_files = res.tfiles;
 448         buf->f_ffree = res.afiles;
 449
 450         buf->f_namelen = server->namelen;
 451
 452         return 0;
 453
 454  out_err:
 455         dprintk("%s: statfs error = %d\n", __func__, -error);
 456         return error;
 457 }
 458
 459 /*
 460  * Map the security flavour number to a name
 461  */
 462 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
 463 {
 464         static const struct {
 465                 rpc_authflavor_t flavour;
 466                 const char *str;
 467         } sec_flavours[] = {
 468                 { RPC_AUTH_NULL, "null" },
 469                 { RPC_AUTH_UNIX, "sys" },
 470                 { RPC_AUTH_GSS_KRB5, "krb5" },
 471                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
 472                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
 473                 { RPC_AUTH_GSS_LKEY, "lkey" },
 474                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
 475                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
 476                 { RPC_AUTH_GSS_SPKM, "spkm" },
 477                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
 478                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
 479                 { UINT_MAX, "unknown" }
 480         };
 481         int i;
 482
 483         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
 484                 if (sec_flavours[i].flavour == flavour)
 485                         break;
 486         }
 487         return sec_flavours[i].str;
 488 }
 489
 490 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
 491                                     int showdefaults)
 492 {
 493         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
 494
 495         switch (sap->sa_family) {
 496         case AF_INET: {
 497                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 498                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
 499                 break;
 500         }
 501         case AF_INET6: {
 502                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 503                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
 504                 break;
 505         }
 506         default:
 507                 if (showdefaults)
 508                         seq_printf(m, ",mountaddr=unspecified");
 509         }
 510
 511         if (nfss->mountd_version || showdefaults)
 512                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
 513         if (nfss->mountd_port || showdefaults)
 514                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
 515
 516         switch (nfss->mountd_protocol) {
 517         case IPPROTO_UDP:
 518                 seq_printf(m, ",mountproto=udp");
 519                 break;
 520         case IPPROTO_TCP:
 521                 seq_printf(m, ",mountproto=tcp");
 522                 break;
 523         default:
 524                 if (showdefaults)
 525                         seq_printf(m, ",mountproto=auto");
 526         }
 527 }
 528
 529 /*
 530  * Describe the mount options in force on this server representation
 531  */
 532 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 533                                    int showdefaults)
 534 {
 535         static const struct proc_nfs_info {
 536                 int flag;
 537                 const char *str;
 538                 const char *nostr;
 539         } nfs_info[] = {
 540                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
 541                 { NFS_MOUNT_POSIX, ",posix", "" },
 542                 { NFS_MOUNT_NOCTO, ",nocto", "" },
 543                 { NFS_MOUNT_NOAC, ",noac", "" },
 544                 { NFS_MOUNT_NONLM, ",nolock", "" },
 545                 { NFS_MOUNT_NOACL, ",noacl", "" },
 546                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
 547                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
 548                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
 549                 { 0, NULL, NULL }
 550         };
 551         const struct proc_nfs_info *nfs_infop;
 552         struct nfs_client *clp = nfss->nfs_client;
 553         u32 version = clp->rpc_ops->version;
 554
 555         seq_printf(m, ",vers=%u", version);
 556         seq_printf(m, ",rsize=%u", nfss->rsize);
 557         seq_printf(m, ",wsize=%u", nfss->wsize);
 558         if (nfss->bsize != 0)
 559                 seq_printf(m, ",bsize=%u", nfss->bsize);
 560         seq_printf(m, ",namlen=%u", nfss->namelen);
 561         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
 562                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
 563         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
 564                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
 565         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
 566                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 567         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 568                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
 569         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 570                 if (nfss->flags & nfs_infop->flag)
 571                         seq_puts(m, nfs_infop->str);
 572                 else
 573                         seq_puts(m, nfs_infop->nostr);
 574         }
 575         seq_printf(m, ",proto=%s",
 576                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
 577         if (version == 4) {
 578                 if (nfss->port != NFS_PORT)
 579                         seq_printf(m, ",port=%u", nfss->port);
 580         } else
 581                 if (nfss->port)
 582                         seq_printf(m, ",port=%u", nfss->port);
 583
 584         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
 585         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
 586         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
 587
 588         if (version != 4)
 589                 nfs_show_mountd_options(m, nfss, showdefaults);
 590
 591 #ifdef CONFIG_NFS_V4
 592         if (clp->rpc_ops->version == 4)
 593                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 594 #endif
 595         if (nfss->options & NFS_OPTION_FSCACHE)
 596                 seq_printf(m, ",fsc");
 597 }
 598
 599 /*
 600  * Describe the mount options on this VFS mountpoint
 601  */
 602 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
 603 {
 604         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 605
 606         nfs_show_mount_options(m, nfss, 0);
 607
 608         seq_printf(m, ",addr=%s",
 609                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
 610                                                         RPC_DISPLAY_ADDR));
 611
 612         return 0;
 613 }
 614
 615 /*
 616  * Present statistical information for this VFS mountpoint
 617  */
 618 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
 619 {
 620         int i, cpu;
 621         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
 622         struct rpc_auth *auth = nfss->client->cl_auth;
 623         struct nfs_iostats totals = { };
 624
 625         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
 626
 627         /*
 628          * Display all mount option settings
 629          */
 630         seq_printf(m, "\n\topts:\t");
 631         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
 632         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
 633         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
 634         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
 635         nfs_show_mount_options(m, nfss, 1);
 636
 637         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 638
 639         seq_printf(m, "\n\tcaps:\t");
 640         seq_printf(m, "caps=0x%x", nfss->caps);
 641         seq_printf(m, ",wtmult=%u", nfss->wtmult);
 642         seq_printf(m, ",dtsize=%u", nfss->dtsize);
 643         seq_printf(m, ",bsize=%u", nfss->bsize);
 644         seq_printf(m, ",namlen=%u", nfss->namelen);
 645
 646 #ifdef CONFIG_NFS_V4
 647         if (nfss->nfs_client->rpc_ops->version == 4) {
 648                 seq_printf(m, "\n\tnfsv4:\t");
 649                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
 650                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
 651                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
 652         }
 653 #endif
 654
 655         /*
 656          * Display security flavor in effect for this mount
 657          */
 658         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
 659         if (auth->au_flavor)
 660                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
 661
 662         /*
 663          * Display superblock I/O counters
 664          */
 665         for_each_possible_cpu(cpu) {
 666                 struct nfs_iostats *stats;
 667
 668                 preempt_disable();
 669                 stats = per_cpu_ptr(nfss->io_stats, cpu);
 670
 671                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 672                         totals.events[i] += stats->events[i];
 673                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 674                         totals.bytes[i] += stats->bytes[i];
 675 #ifdef CONFIG_NFS_FSCACHE
 676                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 677                         totals.fscache[i] += stats->fscache[i];
 678 #endif
 679
 680                 preempt_enable();
 681         }
 682
 683         seq_printf(m, "\n\tevents:\t");
 684         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
 685                 seq_printf(m, "%lu ", totals.events[i]);
 686         seq_printf(m, "\n\tbytes:\t");
 687         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
 688                 seq_printf(m, "%Lu ", totals.bytes[i]);
 689 #ifdef CONFIG_NFS_FSCACHE
 690         if (nfss->options & NFS_OPTION_FSCACHE) {
 691                 seq_printf(m, "\n\tfsc:\t");
 692                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
 693                         seq_printf(m, "%Lu ", totals.bytes[i]);
 694         }
 695 #endif
 696         seq_printf(m, "\n");
 697
 698         rpc_print_iostats(m, nfss->client);
 699
 700         return 0;
 701 }
 702
 703 /*
 704  * Begin unmount by attempting to remove all automounted mountpoints we added
 705  * in response to xdev traversals and referrals
 706  */
 707 static void nfs_umount_begin(struct super_block *sb)
 708 {
 709         struct nfs_server *server;
 710         struct rpc_clnt *rpc;
 711
 712         lock_kernel();
 713
 714         server = NFS_SB(sb);
 715         /* -EIO all pending I/O */
 716         rpc = server->client_acl;
 717         if (!IS_ERR(rpc))
 718                 rpc_killall_tasks(rpc);
 719         rpc = server->client;
 720         if (!IS_ERR(rpc))
 721                 rpc_killall_tasks(rpc);
 722
 723         unlock_kernel();
 724 }
 725
 726 /*
 727  * Sanity-check a server address provided by the mount command.
 728  *
 729  * Address family must be initialized, and address must not be
 730  * the ANY address for that family.
 731  */
 732 static int nfs_verify_server_address(struct sockaddr *addr)
 733 {
 734         switch (addr->sa_family) {
 735         case AF_INET: {
 736                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 737                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 738         }
 739         case AF_INET6: {
 740                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 741                 return !ipv6_addr_any(sa);
 742         }
 743         }
 744
 745         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 746         return 0;
 747 }
 748
 749 /*
 750  * Sanity check the NFS transport protocol.
 751  *
 752  */
 753 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
 754 {
 755         switch (mnt->nfs_server.protocol) {
 756         case XPRT_TRANSPORT_UDP:
 757         case XPRT_TRANSPORT_TCP:
 758         case XPRT_TRANSPORT_RDMA:
 759                 break;
 760         default:
 761                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 762         }
 763 }
 764
 765 /*
 766  * For text based NFSv2/v3 mounts, the mount protocol transport default
 767  * settings should depend upon the specified NFS transport.
 768  */
 769 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
 770 {
 771         nfs_validate_transport_protocol(mnt);
 772
 773         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 774             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
 775                         return;
 776         switch (mnt->nfs_server.protocol) {
 777         case XPRT_TRANSPORT_UDP:
 778                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
 779                 break;
 780         case XPRT_TRANSPORT_TCP:
 781         case XPRT_TRANSPORT_RDMA:
 782                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
 783         }
 784 }
 785
 786 /*
 787  * Parse the value of the 'sec=' option.
 788  */
 789 static int nfs_parse_security_flavors(char *value,
 790                                       struct nfs_parsed_mount_data *mnt)
 791 {
 792         substring_t args[MAX_OPT_ARGS];
 793
 794         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
 795
 796         switch (match_token(value, nfs_secflavor_tokens, args)) {
 797         case Opt_sec_none:
 798                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
 799                 break;
 800         case Opt_sec_sys:
 801                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
 802                 break;
 803         case Opt_sec_krb5:
 804                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
 805                 break;
 806         case Opt_sec_krb5i:
 807                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
 808                 break;
 809         case Opt_sec_krb5p:
 810                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
 811                 break;
 812         case Opt_sec_lkey:
 813                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
 814                 break;
 815         case Opt_sec_lkeyi:
 816                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
 817                 break;
 818         case Opt_sec_lkeyp:
 819                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
 820                 break;
 821         case Opt_sec_spkm:
 822                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
 823                 break;
 824         case Opt_sec_spkmi:
 825                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
 826                 break;
 827         case Opt_sec_spkmp:
 828                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
 829                 break;
 830         default:
 831                 return 0;
 832         }
 833
 834         mnt->auth_flavor_len = 1;
 835         return 1;
 836 }
 837
 838 /*
 839  * Error-check and convert a string of mount options from user space into
 840  * a data structure.  The whole mount string is processed; bad options are
 841  * skipped as they are encountered.  If there were no errors, return 1;
 842  * otherwise return 0 (zero).
 843  */
 844 static int nfs_parse_mount_options(char *raw,
 845                                    struct nfs_parsed_mount_data *mnt)
 846 {
 847         char *p, *string, *secdata;
 848         int rc, sloppy = 0, invalid_option = 0;
 849
 850         if (!raw) {
 851                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
 852                 return 1;
 853         }
 854         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 855
 856         secdata = alloc_secdata();
 857         if (!secdata)
 858                 goto out_nomem;
 859
 860         rc = security_sb_copy_data(raw, secdata);
 861         if (rc)
 862                 goto out_security_failure;
 863
 864         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
 865         if (rc)
 866                 goto out_security_failure;
 867
 868         free_secdata(secdata);
 869
 870         while ((p = strsep(&raw, ",")) != NULL) {
 871                 substring_t args[MAX_OPT_ARGS];
 872                 unsigned long option;
 873                 int token;
 874
 875                 if (!*p)
 876                         continue;
 877
 878                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
 879
 880                 token = match_token(p, nfs_mount_option_tokens, args);
 881                 switch (token) {
 882
 883                 /*
 884                  * boolean options:  foo/nofoo
 885                  */
 886                 case Opt_soft:
 887                         mnt->flags |= NFS_MOUNT_SOFT;
 888                         break;
 889                 case Opt_hard:
 890                         mnt->flags &= ~NFS_MOUNT_SOFT;
 891                         break;
 892                 case Opt_posix:
 893                         mnt->flags |= NFS_MOUNT_POSIX;
 894                         break;
 895                 case Opt_noposix:
 896                         mnt->flags &= ~NFS_MOUNT_POSIX;
 897                         break;
 898                 case Opt_cto:
 899                         mnt->flags &= ~NFS_MOUNT_NOCTO;
 900                         break;
 901                 case Opt_nocto:
 902                         mnt->flags |= NFS_MOUNT_NOCTO;
 903                         break;
 904                 case Opt_ac:
 905                         mnt->flags &= ~NFS_MOUNT_NOAC;
 906                         break;
 907                 case Opt_noac:
 908                         mnt->flags |= NFS_MOUNT_NOAC;
 909                         break;
 910                 case Opt_lock:
 911                         mnt->flags &= ~NFS_MOUNT_NONLM;
 912                         break;
 913                 case Opt_nolock:
 914                         mnt->flags |= NFS_MOUNT_NONLM;
 915                         break;
 916                 case Opt_v2:
 917                         mnt->flags &= ~NFS_MOUNT_VER3;
 918                         break;
 919                 case Opt_v3:
 920                         mnt->flags |= NFS_MOUNT_VER3;
 921                         break;
 922                 case Opt_udp:
 923                         mnt->flags &= ~NFS_MOUNT_TCP;
 924                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 925                         break;
 926                 case Opt_tcp:
 927                         mnt->flags |= NFS_MOUNT_TCP;
 928                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 929                         break;
 930                 case Opt_rdma:
 931                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
 932                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 933                         xprt_load_transport(p);
 934                         break;
 935                 case Opt_acl:
 936                         mnt->flags &= ~NFS_MOUNT_NOACL;
 937                         break;
 938                 case Opt_noacl:
 939                         mnt->flags |= NFS_MOUNT_NOACL;
 940                         break;
 941                 case Opt_rdirplus:
 942                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
 943                         break;
 944                 case Opt_nordirplus:
 945                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
 946                         break;
 947                 case Opt_sharecache:
 948                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
 949                         break;
 950                 case Opt_nosharecache:
 951                         mnt->flags |= NFS_MOUNT_UNSHARED;
 952                         break;
 953                 case Opt_resvport:
 954                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
 955                         break;
 956                 case Opt_noresvport:
 957                         mnt->flags |= NFS_MOUNT_NORESVPORT;
 958                         break;
 959                 case Opt_fscache:
 960                         mnt->options |= NFS_OPTION_FSCACHE;
 961                         kfree(mnt->fscache_uniq);
 962                         mnt->fscache_uniq = NULL;
 963                         break;
 964                 case Opt_nofscache:
 965                         mnt->options &= ~NFS_OPTION_FSCACHE;
 966                         kfree(mnt->fscache_uniq);
 967                         mnt->fscache_uniq = NULL;
 968                         break;
 969                 case Opt_fscache_uniq:
 970                         string = match_strdup(args);
 971                         if (!string)
 972                                 goto out_nomem;
 973                         kfree(mnt->fscache_uniq);
 974                         mnt->fscache_uniq = string;
 975                         mnt->options |= NFS_OPTION_FSCACHE;
 976                         break;
 977
 978                 /*
 979                  * options that take numeric values
 980                  */
 981                 case Opt_port:
 982                         string = match_strdup(args);
 983                         if (string == NULL)
 984                                 goto out_nomem;
 985                         rc = strict_strtoul(string, 10, &option);
 986                         kfree(string);
 987                         if (rc != 0 || option > USHORT_MAX)
 988                                 goto out_invalid_value;
 989                         mnt->nfs_server.port = option;
 990                         break;
 991                 case Opt_rsize:
 992                         string = match_strdup(args);
 993                         if (string == NULL)
 994                                 goto out_nomem;
 995                         rc = strict_strtoul(string, 10, &option);
 996                         kfree(string);
 997                         if (rc != 0)
 998                                 goto out_invalid_value;
 999                         mnt->rsize = option;
1000                         break;
1001                 case Opt_wsize:
1002                         string = match_strdup(args);
1003                         if (string == NULL)
1004                                 goto out_nomem;
1005                         rc = strict_strtoul(string, 10, &option);
1006                         kfree(string);
1007                         if (rc != 0)
1008                                 goto out_invalid_value;
1009                         mnt->wsize = option;
1010                         break;
1011                 case Opt_bsize:
1012                         string = match_strdup(args);
1013                         if (string == NULL)
1014                                 goto out_nomem;
1015                         rc = strict_strtoul(string, 10, &option);
1016                         kfree(string);
1017                         if (rc != 0)
1018                                 goto out_invalid_value;
1019                         mnt->bsize = option;
1020                         break;
1021                 case Opt_timeo:
1022                         string = match_strdup(args);
1023                         if (string == NULL)
1024                                 goto out_nomem;
1025                         rc = strict_strtoul(string, 10, &option);
1026                         kfree(string);
1027                         if (rc != 0 || option == 0)
1028                                 goto out_invalid_value;
1029                         mnt->timeo = option;
1030                         break;
1031                 case Opt_retrans:
1032                         string = match_strdup(args);
1033                         if (string == NULL)
1034                                 goto out_nomem;
1035                         rc = strict_strtoul(string, 10, &option);
1036                         kfree(string);
1037                         if (rc != 0 || option == 0)
1038                                 goto out_invalid_value;
1039                         mnt->retrans = option;
1040                         break;
1041                 case Opt_acregmin:
1042                         string = match_strdup(args);
1043                         if (string == NULL)
1044                                 goto out_nomem;
1045                         rc = strict_strtoul(string, 10, &option);
1046                         kfree(string);
1047                         if (rc != 0)
1048                                 goto out_invalid_value;
1049                         mnt->acregmin = option;
1050                         break;
1051                 case Opt_acregmax:
1052                         string = match_strdup(args);
1053                         if (string == NULL)
1054                                 goto out_nomem;
1055                         rc = strict_strtoul(string, 10, &option);
1056                         kfree(string);
1057                         if (rc != 0)
1058                                 goto out_invalid_value;
1059                         mnt->acregmax = option;
1060                         break;
1061                 case Opt_acdirmin:
1062                         string = match_strdup(args);
1063                         if (string == NULL)
1064                                 goto out_nomem;
1065                         rc = strict_strtoul(string, 10, &option);
1066                         kfree(string);
1067                         if (rc != 0)
1068                                 goto out_invalid_value;
1069                         mnt->acdirmin = option;
1070                         break;
1071                 case Opt_acdirmax:
1072                         string = match_strdup(args);
1073                         if (string == NULL)
1074                                 goto out_nomem;
1075                         rc = strict_strtoul(string, 10, &option);
1076                         kfree(string);
1077                         if (rc != 0)
1078                                 goto out_invalid_value;
1079                         mnt->acdirmax = option;
1080                         break;
1081                 case Opt_actimeo:
1082                         string = match_strdup(args);
1083                         if (string == NULL)
1084                                 goto out_nomem;
1085                         rc = strict_strtoul(string, 10, &option);
1086                         kfree(string);
1087                         if (rc != 0)
1088                                 goto out_invalid_value;
1089                         mnt->acregmin = mnt->acregmax =
1090                         mnt->acdirmin = mnt->acdirmax = option;
1091                         break;
1092                 case Opt_namelen:
1093                         string = match_strdup(args);
1094                         if (string == NULL)
1095                                 goto out_nomem;
1096                         rc = strict_strtoul(string, 10, &option);
1097                         kfree(string);
1098                         if (rc != 0)
1099                                 goto out_invalid_value;
1100                         mnt->namlen = option;
1101                         break;
1102                 case Opt_mountport:
1103                         string = match_strdup(args);
1104                         if (string == NULL)
1105                                 goto out_nomem;
1106                         rc = strict_strtoul(string, 10, &option);
1107                         kfree(string);
1108                         if (rc != 0 || option > USHORT_MAX)
1109                                 goto out_invalid_value;
1110                         mnt->mount_server.port = option;
1111                         break;
1112                 case Opt_mountvers:
1113                         string = match_strdup(args);
1114                         if (string == NULL)
1115                                 goto out_nomem;
1116                         rc = strict_strtoul(string, 10, &option);
1117                         kfree(string);
1118                         if (rc != 0 ||
1119                             option < NFS_MNT_VERSION ||
1120                             option > NFS_MNT3_VERSION)
1121                                 goto out_invalid_value;
1122                         mnt->mount_server.version = option;
1123                         break;
1124                 case Opt_nfsvers:
1125                         string = match_strdup(args);
1126                         if (string == NULL)
1127                                 goto out_nomem;
1128                         rc = strict_strtoul(string, 10, &option);
1129                         kfree(string);
1130                         if (rc != 0)
1131                                 goto out_invalid_value;
1132                         switch (option) {
1133                         case NFS2_VERSION:
1134                                 mnt->flags &= ~NFS_MOUNT_VER3;
1135                                 break;
1136                         case NFS3_VERSION:
1137                                 mnt->flags |= NFS_MOUNT_VER3;
1138                                 break;
1139                         default:
1140                                 goto out_invalid_value;
1141                         }
1142                         break;
1143                 case Opt_minorversion:
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                         if (option > NFS4_MAX_MINOR_VERSION)
1152                                 goto out_invalid_value;
1153                         mnt->minorversion = option;
1154                         break;
1155
1156                 /*
1157                  * options that take text values
1158                  */
1159                 case Opt_sec:
1160                         string = match_strdup(args);
1161                         if (string == NULL)
1162                                 goto out_nomem;
1163                         rc = nfs_parse_security_flavors(string, mnt);
1164                         kfree(string);
1165                         if (!rc) {
1166                                 dfprintk(MOUNT, "NFS:   unrecognized "
1167                                                 "security flavor\n");
1168                                 return 0;
1169                         }
1170                         break;
1171                 case Opt_proto:
1172                         string = match_strdup(args);
1173                         if (string == NULL)
1174                                 goto out_nomem;
1175                         token = match_token(string,
1176                                             nfs_xprt_protocol_tokens, args);
1177
1178                         switch (token) {
1179                         case Opt_xprt_udp:
1180                                 mnt->flags &= ~NFS_MOUNT_TCP;
1181                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1182                                 kfree(string);
1183                                 break;
1184                         case Opt_xprt_tcp:
1185                                 mnt->flags |= NFS_MOUNT_TCP;
1186                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1187                                 kfree(string);
1188                                 break;
1189                         case Opt_xprt_rdma:
1190                                 /* vector side protocols to TCP */
1191                                 mnt->flags |= NFS_MOUNT_TCP;
1192                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1193                                 xprt_load_transport(string);
1194                                 kfree(string);
1195                                 break;
1196                         default:
1197                                 dfprintk(MOUNT, "NFS:   unrecognized "
1198                                                 "transport protocol\n");
1199                                 return 0;
1200                         }
1201                         break;
1202                 case Opt_mountproto:
1203                         string = match_strdup(args);
1204                         if (string == NULL)
1205                                 goto out_nomem;
1206                         token = match_token(string,
1207                                             nfs_xprt_protocol_tokens, args);
1208                         kfree(string);
1209
1210                         switch (token) {
1211                         case Opt_xprt_udp:
1212                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1213                                 break;
1214                         case Opt_xprt_tcp:
1215                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1216                                 break;
1217                         case Opt_xprt_rdma: /* not used for side protocols */
1218                         default:
1219                                 dfprintk(MOUNT, "NFS:   unrecognized "
1220                                                 "transport protocol\n");
1221                                 return 0;
1222                         }
1223                         break;
1224                 case Opt_addr:
1225                         string = match_strdup(args);
1226                         if (string == NULL)
1227                                 goto out_nomem;
1228                         mnt->nfs_server.addrlen =
1229                                 rpc_pton(string, strlen(string),
1230                                         (struct sockaddr *)
1231                                         &mnt->nfs_server.address,
1232                                         sizeof(mnt->nfs_server.address));
1233                         kfree(string);
1234                         if (mnt->nfs_server.addrlen == 0)
1235                                 goto out_invalid_address;
1236                         break;
1237                 case Opt_clientaddr:
1238                         string = match_strdup(args);
1239                         if (string == NULL)
1240                                 goto out_nomem;
1241                         kfree(mnt->client_address);
1242                         mnt->client_address = string;
1243                         break;
1244                 case Opt_mounthost:
1245                         string = match_strdup(args);
1246                         if (string == NULL)
1247                                 goto out_nomem;
1248                         kfree(mnt->mount_server.hostname);
1249                         mnt->mount_server.hostname = string;
1250                         break;
1251                 case Opt_mountaddr:
1252                         string = match_strdup(args);
1253                         if (string == NULL)
1254                                 goto out_nomem;
1255                         mnt->mount_server.addrlen =
1256                                 rpc_pton(string, strlen(string),
1257                                         (struct sockaddr *)
1258                                         &mnt->mount_server.address,
1259                                         sizeof(mnt->mount_server.address));
1260                         kfree(string);
1261                         if (mnt->mount_server.addrlen == 0)
1262                                 goto out_invalid_address;
1263                         break;
1264                 case Opt_lookupcache:
1265                         string = match_strdup(args);
1266                         if (string == NULL)
1267                                 goto out_nomem;
1268                         token = match_token(string,
1269                                         nfs_lookupcache_tokens, args);
1270                         kfree(string);
1271                         switch (token) {
1272                                 case Opt_lookupcache_all:
1273                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1274                                         break;
1275                                 case Opt_lookupcache_positive:
1276                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1277                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1278                                         break;
1279                                 case Opt_lookupcache_none:
1280                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1281                                         break;
1282                                 default:
1283                                         dfprintk(MOUNT, "NFS:   invalid "
1284                                                         "lookupcache argument\n");
1285                                         return 0;
1286                         };
1287                         break;
1288
1289                 /*
1290                  * Special options
1291                  */
1292                 case Opt_sloppy:
1293                         sloppy = 1;
1294                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1295                         break;
1296                 case Opt_userspace:
1297                 case Opt_deprecated:
1298                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1299                                         "'%s'\n", p);
1300                         break;
1301
1302                 default:
1303                         invalid_option = 1;
1304                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1305                                         "'%s'\n", p);
1306                 }
1307         }
1308
1309         if (!sloppy && invalid_option)
1310                 return 0;
1311
1312         return 1;
1313
1314 out_invalid_address:
1315         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1316         return 0;
1317 out_invalid_value:
1318         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1319         return 0;
1320 out_nomem:
1321         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1322         return 0;
1323 out_security_failure:
1324         free_secdata(secdata);
1325         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1326         return 0;
1327 }
1328
1329 /*
1330  * Match the requested auth flavors with the list returned by
1331  * the server.  Returns zero and sets the mount's authentication
1332  * flavor on success; returns -EACCES if server does not support
1333  * the requested flavor.
1334  */
1335 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1336                              struct nfs_mount_request *request)
1337 {
1338         unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1339
1340         /*
1341          * Certain releases of Linux's mountd return an empty
1342          * flavor list.  To prevent behavioral regression with
1343          * these servers (ie. rejecting mounts that used to
1344          * succeed), revert to pre-2.6.32 behavior (no checking)
1345          * if the returned flavor list is empty.
1346          */
1347         if (server_authlist_len == 0)
1348                 return 0;
1349
1350         /*
1351          * We avoid sophisticated negotiating here, as there are
1352          * plenty of cases where we can get it wrong, providing
1353          * either too little or too much security.
1354          *
1355          * RFC 2623, section 2.7 suggests we SHOULD prefer the
1356          * flavor listed first.  However, some servers list
1357          * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1358          * preferred default, in args->auth_flavors[0] if user
1359          * didn't specify sec= mount option.
1360          */
1361         for (i = 0; i < args->auth_flavor_len; i++)
1362                 for (j = 0; j < server_authlist_len; j++)
1363                         if (args->auth_flavors[i] == request->auth_flavs[j]) {
1364                                 dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1365                                         request->auth_flavs[j]);
1366                                 args->auth_flavors[0] = request->auth_flavs[j];
1367                                 return 0;
1368                         }
1369
1370         dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1371         nfs_umount(request);
1372         return -EACCES;
1373 }
1374
1375 /*
1376  * Use the remote server's MOUNT service to request the NFS file handle
1377  * corresponding to the provided path.
1378  */
1379 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1380                          struct nfs_fh *root_fh)
1381 {
1382         rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1383         unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1384         struct nfs_mount_request request = {
1385                 .sap            = (struct sockaddr *)
1386                                                 &args->mount_server.address,
1387                 .dirpath        = args->nfs_server.export_path,
1388                 .protocol       = args->mount_server.protocol,
1389                 .fh             = root_fh,
1390                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1391                 .auth_flav_len  = &server_authlist_len,
1392                 .auth_flavs     = server_authlist,
1393         };
1394         int status;
1395
1396         if (args->mount_server.version == 0) {
1397                 if (args->flags & NFS_MOUNT_VER3)
1398                         args->mount_server.version = NFS_MNT3_VERSION;
1399                 else
1400                         args->mount_server.version = NFS_MNT_VERSION;
1401         }
1402         request.version = args->mount_server.version;
1403
1404         if (args->mount_server.hostname)
1405                 request.hostname = args->mount_server.hostname;
1406         else
1407                 request.hostname = args->nfs_server.hostname;
1408
1409         /*
1410          * Construct the mount server's address.
1411          */
1412         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1413                 memcpy(request.sap, &args->nfs_server.address,
1414                        args->nfs_server.addrlen);
1415                 args->mount_server.addrlen = args->nfs_server.addrlen;
1416         }
1417         request.salen = args->mount_server.addrlen;
1418
1419         /*
1420          * autobind will be used if mount_server.port == 0
1421          */
1422         rpc_set_port(request.sap, args->mount_server.port);
1423
1424         /*
1425          * Now ask the mount server to map our export path
1426          * to a file handle.
1427          */
1428         status = nfs_mount(&request);
1429         if (status != 0) {
1430                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1431                                 request.hostname, status);
1432                 return status;
1433         }
1434
1435         /*
1436          * MNTv1 (NFSv2) does not support auth flavor negotiation.
1437          */
1438         if (args->mount_server.version != NFS_MNT3_VERSION)
1439                 return 0;
1440         return nfs_walk_authlist(args, &request);
1441 }
1442
1443 static int nfs_parse_simple_hostname(const char *dev_name,
1444                                      char **hostname, size_t maxnamlen,
1445                                      char **export_path, size_t maxpathlen)
1446 {
1447         size_t len;
1448         char *colon, *comma;
1449
1450         colon = strchr(dev_name, ':');
1451         if (colon == NULL)
1452                 goto out_bad_devname;
1453
1454         len = colon - dev_name;
1455         if (len > maxnamlen)
1456                 goto out_hostname;
1457
1458         /* N.B. caller will free nfs_server.hostname in all cases */
1459         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1460         if (!*hostname)
1461                 goto out_nomem;
1462
1463         /* kill possible hostname list: not supported */
1464         comma = strchr(*hostname, ',');
1465         if (comma != NULL) {
1466                 if (comma == *hostname)
1467                         goto out_bad_devname;
1468                 *comma = '\0';
1469         }
1470
1471         colon++;
1472         len = strlen(colon);
1473         if (len > maxpathlen)
1474                 goto out_path;
1475         *export_path = kstrndup(colon, len, GFP_KERNEL);
1476         if (!*export_path)
1477                 goto out_nomem;
1478
1479         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1480         return 0;
1481
1482 out_bad_devname:
1483         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1484         return -EINVAL;
1485
1486 out_nomem:
1487         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1488         return -ENOMEM;
1489
1490 out_hostname:
1491         dfprintk(MOUNT, "NFS: server hostname too long\n");
1492         return -ENAMETOOLONG;
1493
1494 out_path:
1495         dfprintk(MOUNT, "NFS: export pathname too long\n");
1496         return -ENAMETOOLONG;
1497 }
1498
1499 /*
1500  * Hostname has square brackets around it because it contains one or
1501  * more colons.  We look for the first closing square bracket, and a
1502  * colon must follow it.
1503  */
1504 static int nfs_parse_protected_hostname(const char *dev_name,
1505                                         char **hostname, size_t maxnamlen,
1506                                         char **export_path, size_t maxpathlen)
1507 {
1508         size_t len;
1509         char *start, *end;
1510
1511         start = (char *)(dev_name + 1);
1512
1513         end = strchr(start, ']');
1514         if (end == NULL)
1515                 goto out_bad_devname;
1516         if (*(end + 1) != ':')
1517                 goto out_bad_devname;
1518
1519         len = end - start;
1520         if (len > maxnamlen)
1521                 goto out_hostname;
1522
1523         /* N.B. caller will free nfs_server.hostname in all cases */
1524         *hostname = kstrndup(start, len, GFP_KERNEL);
1525         if (*hostname == NULL)
1526                 goto out_nomem;
1527
1528         end += 2;
1529         len = strlen(end);
1530         if (len > maxpathlen)
1531                 goto out_path;
1532         *export_path = kstrndup(end, len, GFP_KERNEL);
1533         if (!*export_path)
1534                 goto out_nomem;
1535
1536         return 0;
1537
1538 out_bad_devname:
1539         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1540         return -EINVAL;
1541
1542 out_nomem:
1543         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1544         return -ENOMEM;
1545
1546 out_hostname:
1547         dfprintk(MOUNT, "NFS: server hostname too long\n");
1548         return -ENAMETOOLONG;
1549
1550 out_path:
1551         dfprintk(MOUNT, "NFS: export pathname too long\n");
1552         return -ENAMETOOLONG;
1553 }
1554
1555 /*
1556  * Split "dev_name" into "hostname:export_path".
1557  *
1558  * The leftmost colon demarks the split between the server's hostname
1559  * and the export path.  If the hostname starts with a left square
1560  * bracket, then it may contain colons.
1561  *
1562  * Note: caller frees hostname and export path, even on error.
1563  */
1564 static int nfs_parse_devname(const char *dev_name,
1565                              char **hostname, size_t maxnamlen,
1566                              char **export_path, size_t maxpathlen)
1567 {
1568         if (*dev_name == '[')
1569                 return nfs_parse_protected_hostname(dev_name,
1570                                                     hostname, maxnamlen,
1571                                                     export_path, maxpathlen);
1572
1573         return nfs_parse_simple_hostname(dev_name,
1574                                          hostname, maxnamlen,
1575                                          export_path, maxpathlen);
1576 }
1577
1578 /*
1579  * Validate the NFS2/NFS3 mount data
1580  * - fills in the mount root filehandle
1581  *
1582  * For option strings, user space handles the following behaviors:
1583  *
1584  * + DNS: mapping server host name to IP address ("addr=" option)
1585  *
1586  * + failure mode: how to behave if a mount request can't be handled
1587  *   immediately ("fg/bg" option)
1588  *
1589  * + retry: how often to retry a mount request ("retry=" option)
1590  *
1591  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1592  *   mountproto=tcp after mountproto=udp, and so on
1593  */
1594 static int nfs_validate_mount_data(void *options,
1595                                    struct nfs_parsed_mount_data *args,
1596                                    struct nfs_fh *mntfh,
1597                                    const char *dev_name)
1598 {
1599         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1600
1601         if (data == NULL)
1602                 goto out_no_data;
1603
1604         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1605         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1606         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1607         args->acregmin          = NFS_DEF_ACREGMIN;
1608         args->acregmax          = NFS_DEF_ACREGMAX;
1609         args->acdirmin          = NFS_DEF_ACDIRMIN;
1610         args->acdirmax          = NFS_DEF_ACDIRMAX;
1611         args->mount_server.port = 0;    /* autobind unless user sets port */
1612         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1613         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1614         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1615         args->auth_flavor_len   = 1;
1616
1617         switch (data->version) {
1618         case 1:
1619                 data->namlen = 0;
1620         case 2:
1621                 data->bsize = 0;
1622         case 3:
1623                 if (data->flags & NFS_MOUNT_VER3)
1624                         goto out_no_v3;
1625                 data->root.size = NFS2_FHSIZE;
1626                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1627         case 4:
1628                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1629                         goto out_no_sec;
1630         case 5:
1631                 memset(data->context, 0, sizeof(data->context));
1632         case 6:
1633                 if (data->flags & NFS_MOUNT_VER3) {
1634                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1635                                 goto out_invalid_fh;
1636                         mntfh->size = data->root.size;
1637                 } else
1638                         mntfh->size = NFS2_FHSIZE;
1639
1640
1641                 memcpy(mntfh->data, data->root.data, mntfh->size);
1642                 if (mntfh->size < sizeof(mntfh->data))
1643                         memset(mntfh->data + mntfh->size, 0,
1644                                sizeof(mntfh->data) - mntfh->size);
1645
1646                 /*
1647                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1648                  * can deal with.
1649                  */
1650                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1651                 args->rsize             = data->rsize;
1652                 args->wsize             = data->wsize;
1653                 args->timeo             = data->timeo;
1654                 args->retrans           = data->retrans;
1655                 args->acregmin          = data->acregmin;
1656                 args->acregmax          = data->acregmax;
1657                 args->acdirmin          = data->acdirmin;
1658                 args->acdirmax          = data->acdirmax;
1659
1660                 memcpy(&args->nfs_server.address, &data->addr,
1661                        sizeof(data->addr));
1662                 args->nfs_server.addrlen = sizeof(data->addr);
1663                 if (!nfs_verify_server_address((struct sockaddr *)
1664                                                 &args->nfs_server.address))
1665                         goto out_no_address;
1666
1667                 if (!(data->flags & NFS_MOUNT_TCP))
1668                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1669                 /* N.B. caller will free nfs_server.hostname in all cases */
1670                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1671                 args->namlen            = data->namlen;
1672                 args->bsize             = data->bsize;
1673
1674                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1675                         args->auth_flavors[0] = data->pseudoflavor;
1676                 if (!args->nfs_server.hostname)
1677                         goto out_nomem;
1678
1679                 /*
1680                  * The legacy version 6 binary mount data from userspace has a
1681                  * field used only to transport selinux information into the
1682                  * the kernel.  To continue to support that functionality we
1683                  * have a touch of selinux knowledge here in the NFS code. The
1684                  * userspace code converted context=blah to just blah so we are
1685                  * converting back to the full string selinux understands.
1686                  */
1687                 if (data->context[0]){
1688 #ifdef CONFIG_SECURITY_SELINUX
1689                         int rc;
1690                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1691                         if (!opts_str)
1692                                 return -ENOMEM;
1693                         strcpy(opts_str, "context=");
1694                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1695                         strcat(opts_str, &data->context[0]);
1696                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1697                         kfree(opts_str);
1698                         if (rc)
1699                                 return rc;
1700 #else
1701                         return -EINVAL;
1702 #endif
1703                 }
1704
1705                 break;
1706         default: {
1707                 int status;
1708
1709                 if (nfs_parse_mount_options((char *)options, args) == 0)
1710                         return -EINVAL;
1711
1712                 if (!nfs_verify_server_address((struct sockaddr *)
1713                                                 &args->nfs_server.address))
1714                         goto out_no_address;
1715
1716                 rpc_set_port((struct sockaddr *)&args->nfs_server.address,
1717                                 args->nfs_server.port);
1718
1719                 nfs_set_mount_transport_protocol(args);
1720
1721                 status = nfs_parse_devname(dev_name,
1722                                            &args->nfs_server.hostname,
1723                                            PAGE_SIZE,
1724                                            &args->nfs_server.export_path,
1725                                            NFS_MAXPATHLEN);
1726                 if (!status)
1727                         status = nfs_try_mount(args, mntfh);
1728
1729                 kfree(args->nfs_server.export_path);
1730                 args->nfs_server.export_path = NULL;
1731
1732                 if (status)
1733                         return status;
1734
1735                 break;
1736                 }
1737         }
1738
1739 #ifndef CONFIG_NFS_V3
1740         if (args->flags & NFS_MOUNT_VER3)
1741                 goto out_v3_not_compiled;
1742 #endif /* !CONFIG_NFS_V3 */
1743
1744         return 0;
1745
1746 out_no_data:
1747         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1748         return -EINVAL;
1749
1750 out_no_v3:
1751         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1752                  data->version);
1753         return -EINVAL;
1754
1755 out_no_sec:
1756         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1757         return -EINVAL;
1758
1759 #ifndef CONFIG_NFS_V3
1760 out_v3_not_compiled:
1761         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1762         return -EPROTONOSUPPORT;
1763 #endif /* !CONFIG_NFS_V3 */
1764
1765 out_nomem:
1766         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1767         return -ENOMEM;
1768
1769 out_no_address:
1770         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1771         return -EINVAL;
1772
1773 out_invalid_fh:
1774         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1775         return -EINVAL;
1776 }
1777
1778 static int
1779 nfs_compare_remount_data(struct nfs_server *nfss,
1780                          struct nfs_parsed_mount_data *data)
1781 {
1782         if (data->flags != nfss->flags ||
1783             data->rsize != nfss->rsize ||
1784             data->wsize != nfss->wsize ||
1785             data->retrans != nfss->client->cl_timeout->to_retries ||
1786             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1787             data->acregmin != nfss->acregmin / HZ ||
1788             data->acregmax != nfss->acregmax / HZ ||
1789             data->acdirmin != nfss->acdirmin / HZ ||
1790             data->acdirmax != nfss->acdirmax / HZ ||
1791             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1792             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1793             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1794                    data->nfs_server.addrlen) != 0)
1795                 return -EINVAL;
1796
1797         return 0;
1798 }
1799
1800 static int
1801 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1802 {
1803         int error;
1804         struct nfs_server *nfss = sb->s_fs_info;
1805         struct nfs_parsed_mount_data *data;
1806         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1807         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1808         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1809
1810         /*
1811          * Userspace mount programs that send binary options generally send
1812          * them populated with default values. We have no way to know which
1813          * ones were explicitly specified. Fall back to legacy behavior and
1814          * just return success.
1815          */
1816         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1817             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1818                                            options->version <= 6))))
1819                 return 0;
1820
1821         data = kzalloc(sizeof(*data), GFP_KERNEL);
1822         if (data == NULL)
1823                 return -ENOMEM;
1824
1825         lock_kernel();
1826         /* fill out struct with values from existing mount */
1827         data->flags = nfss->flags;
1828         data->rsize = nfss->rsize;
1829         data->wsize = nfss->wsize;
1830         data->retrans = nfss->client->cl_timeout->to_retries;
1831         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1832         data->acregmin = nfss->acregmin / HZ;
1833         data->acregmax = nfss->acregmax / HZ;
1834         data->acdirmin = nfss->acdirmin / HZ;
1835         data->acdirmax = nfss->acdirmax / HZ;
1836         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1837         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1838         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1839                 data->nfs_server.addrlen);
1840
1841         /* overwrite those values with any that were specified */
1842         error = nfs_parse_mount_options((char *)options, data);
1843         if (error < 0)
1844                 goto out;
1845
1846         /* compare new mount options with old ones */
1847         error = nfs_compare_remount_data(nfss, data);
1848 out:
1849         kfree(data);
1850         unlock_kernel();
1851         return error;
1852 }
1853
1854 /*
1855  * Initialise the common bits of the superblock
1856  */
1857 static inline void nfs_initialise_sb(struct super_block *sb)
1858 {
1859         struct nfs_server *server = NFS_SB(sb);
1860
1861         sb->s_magic = NFS_SUPER_MAGIC;
1862
1863         /* We probably want something more informative here */
1864         snprintf(sb->s_id, sizeof(sb->s_id),
1865                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1866
1867         if (sb->s_blocksize == 0)
1868                 sb->s_blocksize = nfs_block_bits(server->wsize,
1869                                                  &sb->s_blocksize_bits);
1870
1871         if (server->flags & NFS_MOUNT_NOAC)
1872                 sb->s_flags |= MS_SYNCHRONOUS;
1873
1874         nfs_super_set_maxbytes(sb, server->maxfilesize);
1875 }
1876
1877 /*
1878  * Finish setting up an NFS2/3 superblock
1879  */
1880 static void nfs_fill_super(struct super_block *sb,
1881                            struct nfs_parsed_mount_data *data)
1882 {
1883         struct nfs_server *server = NFS_SB(sb);
1884
1885         sb->s_blocksize_bits = 0;
1886         sb->s_blocksize = 0;
1887         if (data->bsize)
1888                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1889
1890         if (server->flags & NFS_MOUNT_VER3) {
1891                 /* The VFS shouldn't apply the umask to mode bits. We will do
1892                  * so ourselves when necessary.
1893                  */
1894                 sb->s_flags |= MS_POSIXACL;
1895                 sb->s_time_gran = 1;
1896         }
1897
1898         sb->s_op = &nfs_sops;
1899         nfs_initialise_sb(sb);
1900 }
1901
1902 /*
1903  * Finish setting up a cloned NFS2/3 superblock
1904  */
1905 static void nfs_clone_super(struct super_block *sb,
1906                             const struct super_block *old_sb)
1907 {
1908         struct nfs_server *server = NFS_SB(sb);
1909
1910         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1911         sb->s_blocksize = old_sb->s_blocksize;
1912         sb->s_maxbytes = old_sb->s_maxbytes;
1913
1914         if (server->flags & NFS_MOUNT_VER3) {
1915                 /* The VFS shouldn't apply the umask to mode bits. We will do
1916                  * so ourselves when necessary.
1917                  */
1918                 sb->s_flags |= MS_POSIXACL;
1919                 sb->s_time_gran = 1;
1920         }
1921
1922         sb->s_op = old_sb->s_op;
1923         nfs_initialise_sb(sb);
1924 }
1925
1926 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1927 {
1928         const struct nfs_server *a = s->s_fs_info;
1929         const struct rpc_clnt *clnt_a = a->client;
1930         const struct rpc_clnt *clnt_b = b->client;
1931
1932         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1933                 goto Ebusy;
1934         if (a->nfs_client != b->nfs_client)
1935                 goto Ebusy;
1936         if (a->flags != b->flags)
1937                 goto Ebusy;
1938         if (a->wsize != b->wsize)
1939                 goto Ebusy;
1940         if (a->rsize != b->rsize)
1941                 goto Ebusy;
1942         if (a->acregmin != b->acregmin)
1943                 goto Ebusy;
1944         if (a->acregmax != b->acregmax)
1945                 goto Ebusy;
1946         if (a->acdirmin != b->acdirmin)
1947                 goto Ebusy;
1948         if (a->acdirmax != b->acdirmax)
1949                 goto Ebusy;
1950         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1951                 goto Ebusy;
1952         return 1;
1953 Ebusy:
1954         return 0;
1955 }
1956
1957 struct nfs_sb_mountdata {
1958         struct nfs_server *server;
1959         int mntflags;
1960 };
1961
1962 static int nfs_set_super(struct super_block *s, void *data)
1963 {
1964         struct nfs_sb_mountdata *sb_mntdata = data;
1965         struct nfs_server *server = sb_mntdata->server;
1966         int ret;
1967
1968         s->s_flags = sb_mntdata->mntflags;
1969         s->s_fs_info = server;
1970         ret = set_anon_super(s, server);
1971         if (ret == 0)
1972                 server->s_dev = s->s_dev;
1973         return ret;
1974 }
1975
1976 static int nfs_compare_super_address(struct nfs_server *server1,
1977                                      struct nfs_server *server2)
1978 {
1979         struct sockaddr *sap1, *sap2;
1980
1981         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1982         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1983
1984         if (sap1->sa_family != sap2->sa_family)
1985                 return 0;
1986
1987         switch (sap1->sa_family) {
1988         case AF_INET: {
1989                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1990                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1991                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1992                         return 0;
1993                 if (sin1->sin_port != sin2->sin_port)
1994                         return 0;
1995                 break;
1996         }
1997         case AF_INET6: {
1998                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1999                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2000                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2001                         return 0;
2002                 if (sin1->sin6_port != sin2->sin6_port)
2003                         return 0;
2004                 break;
2005         }
2006         default:
2007                 return 0;
2008         }
2009
2010         return 1;
2011 }
2012
2013 static int nfs_compare_super(struct super_block *sb, void *data)
2014 {
2015         struct nfs_sb_mountdata *sb_mntdata = data;
2016         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2017         int mntflags = sb_mntdata->mntflags;
2018
2019         if (!nfs_compare_super_address(old, server))
2020                 return 0;
2021         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2022         if (old->flags & NFS_MOUNT_UNSHARED)
2023                 return 0;
2024         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2025                 return 0;
2026         return nfs_compare_mount_options(sb, server, mntflags);
2027 }
2028
2029 static int nfs_bdi_register(struct nfs_server *server)
2030 {
2031         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2032 }
2033
2034 static int nfs_get_sb(struct file_system_type *fs_type,
2035         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2036 {
2037         struct nfs_server *server = NULL;
2038         struct super_block *s;
2039         struct nfs_parsed_mount_data *data;
2040         struct nfs_fh *mntfh;
2041         struct dentry *mntroot;
2042         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2043         struct nfs_sb_mountdata sb_mntdata = {
2044                 .mntflags = flags,
2045         };
2046         int error = -ENOMEM;
2047
2048         data = kzalloc(sizeof(*data), GFP_KERNEL);
2049         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2050         if (data == NULL || mntfh == NULL)
2051                 goto out_free_fh;
2052
2053         security_init_mnt_opts(&data->lsm_opts);
2054
2055         /* Validate the mount data */
2056         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2057         if (error < 0)
2058                 goto out;
2059
2060         /* Get a volume representation */
2061         server = nfs_create_server(data, mntfh);
2062         if (IS_ERR(server)) {
2063                 error = PTR_ERR(server);
2064                 goto out;
2065         }
2066         sb_mntdata.server = server;
2067
2068         if (server->flags & NFS_MOUNT_UNSHARED)
2069                 compare_super = NULL;
2070
2071         /* Get a superblock - note that we may end up sharing one that already exists */
2072         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2073         if (IS_ERR(s)) {
2074                 error = PTR_ERR(s);
2075                 goto out_err_nosb;
2076         }
2077
2078         if (s->s_fs_info != server) {
2079                 nfs_free_server(server);
2080                 server = NULL;
2081         } else {
2082                 error = nfs_bdi_register(server);
2083                 if (error)
2084                         goto error_splat_super;
2085         }
2086
2087         if (!s->s_root) {
2088                 /* initial superblock/root creation */
2089                 nfs_fill_super(s, data);
2090                 nfs_fscache_get_super_cookie(s, data);
2091         }
2092
2093         mntroot = nfs_get_root(s, mntfh);
2094         if (IS_ERR(mntroot)) {
2095                 error = PTR_ERR(mntroot);
2096                 goto error_splat_super;
2097         }
2098
2099         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2100         if (error)
2101                 goto error_splat_root;
2102
2103         s->s_flags |= MS_ACTIVE;
2104         mnt->mnt_sb = s;
2105         mnt->mnt_root = mntroot;
2106         error = 0;
2107
2108 out:
2109         kfree(data->nfs_server.hostname);
2110         kfree(data->mount_server.hostname);
2111         kfree(data->fscache_uniq);
2112         security_free_mnt_opts(&data->lsm_opts);
2113 out_free_fh:
2114         kfree(mntfh);
2115         kfree(data);
2116         return error;
2117
2118 out_err_nosb:
2119         nfs_free_server(server);
2120         goto out;
2121
2122 error_splat_root:
2123         dput(mntroot);
2124 error_splat_super:
2125         deactivate_locked_super(s);
2126         goto out;
2127 }
2128
2129 /*
2130  * Destroy an NFS2/3 superblock
2131  */
2132 static void nfs_kill_super(struct super_block *s)
2133 {
2134         struct nfs_server *server = NFS_SB(s);
2135
2136         bdi_unregister(&server->backing_dev_info);
2137         kill_anon_super(s);
2138         nfs_fscache_release_super_cookie(s);
2139         nfs_free_server(server);
2140 }
2141
2142 /*
2143  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2144  */
2145 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2146                            const char *dev_name, void *raw_data,
2147                            struct vfsmount *mnt)
2148 {
2149         struct nfs_clone_mount *data = raw_data;
2150         struct super_block *s;
2151         struct nfs_server *server;
2152         struct dentry *mntroot;
2153         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2154         struct nfs_sb_mountdata sb_mntdata = {
2155                 .mntflags = flags,
2156         };
2157         int error;
2158
2159         dprintk("--> nfs_xdev_get_sb()\n");
2160
2161         /* create a new volume representation */
2162         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2163         if (IS_ERR(server)) {
2164                 error = PTR_ERR(server);
2165                 goto out_err_noserver;
2166         }
2167         sb_mntdata.server = server;
2168
2169         if (server->flags & NFS_MOUNT_UNSHARED)
2170                 compare_super = NULL;
2171
2172         /* Get a superblock - note that we may end up sharing one that already exists */
2173         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2174         if (IS_ERR(s)) {
2175                 error = PTR_ERR(s);
2176                 goto out_err_nosb;
2177         }
2178
2179         if (s->s_fs_info != server) {
2180                 nfs_free_server(server);
2181                 server = NULL;
2182         } else {
2183                 error = nfs_bdi_register(server);
2184                 if (error)
2185                         goto error_splat_super;
2186         }
2187
2188         if (!s->s_root) {
2189                 /* initial superblock/root creation */
2190                 nfs_clone_super(s, data->sb);
2191         }
2192
2193         mntroot = nfs_get_root(s, data->fh);
2194         if (IS_ERR(mntroot)) {
2195                 error = PTR_ERR(mntroot);
2196                 goto error_splat_super;
2197         }
2198         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2199                 dput(mntroot);
2200                 error = -ESTALE;
2201                 goto error_splat_super;
2202         }
2203
2204         s->s_flags |= MS_ACTIVE;
2205         mnt->mnt_sb = s;
2206         mnt->mnt_root = mntroot;
2207
2208         /* clone any lsm security options from the parent to the new sb */
2209         security_sb_clone_mnt_opts(data->sb, s);
2210
2211         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2212         return 0;
2213
2214 out_err_nosb:
2215         nfs_free_server(server);
2216 out_err_noserver:
2217         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2218         return error;
2219
2220 error_splat_super:
2221         deactivate_locked_super(s);
2222         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2223         return error;
2224 }
2225
2226 #ifdef CONFIG_NFS_V4
2227
2228 /*
2229  * Finish setting up a cloned NFS4 superblock
2230  */
2231 static void nfs4_clone_super(struct super_block *sb,
2232                             const struct super_block *old_sb)
2233 {
2234         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2235         sb->s_blocksize = old_sb->s_blocksize;
2236         sb->s_maxbytes = old_sb->s_maxbytes;
2237         sb->s_time_gran = 1;
2238         sb->s_op = old_sb->s_op;
2239         nfs_initialise_sb(sb);
2240 }
2241
2242 /*
2243  * Set up an NFS4 superblock
2244  */
2245 static void nfs4_fill_super(struct super_block *sb)
2246 {
2247         sb->s_time_gran = 1;
2248         sb->s_op = &nfs4_sops;
2249         nfs_initialise_sb(sb);
2250 }
2251
2252 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2253 {
2254         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2255 }
2256
2257 /*
2258  * Validate NFSv4 mount options
2259  */
2260 static int nfs4_validate_mount_data(void *options,
2261                                     struct nfs_parsed_mount_data *args,
2262                                     const char *dev_name)
2263 {
2264         struct sockaddr_in *ap;
2265         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2266         char *c;
2267
2268         if (data == NULL)
2269                 goto out_no_data;
2270
2271         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2272         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2273         args->acregmin          = NFS_DEF_ACREGMIN;
2274         args->acregmax          = NFS_DEF_ACREGMAX;
2275         args->acdirmin          = NFS_DEF_ACDIRMIN;
2276         args->acdirmax          = NFS_DEF_ACDIRMAX;
2277         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2278         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2279         args->auth_flavor_len   = 1;
2280         args->minorversion      = 0;
2281
2282         switch (data->version) {
2283         case 1:
2284                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2285                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2286                         goto out_no_address;
2287                 if (data->host_addrlen == 0)
2288                         goto out_no_address;
2289                 args->nfs_server.addrlen = data->host_addrlen;
2290                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2291                         return -EFAULT;
2292                 if (!nfs_verify_server_address((struct sockaddr *)
2293                                                 &args->nfs_server.address))
2294                         goto out_no_address;
2295
2296                 if (data->auth_flavourlen) {
2297                         if (data->auth_flavourlen > 1)
2298                                 goto out_inval_auth;
2299                         if (copy_from_user(&args->auth_flavors[0],
2300                                            data->auth_flavours,
2301                                            sizeof(args->auth_flavors[0])))
2302                                 return -EFAULT;
2303                 }
2304
2305                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2306                 if (IS_ERR(c))
2307                         return PTR_ERR(c);
2308                 args->nfs_server.hostname = c;
2309
2310                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2311                 if (IS_ERR(c))
2312                         return PTR_ERR(c);
2313                 args->nfs_server.export_path = c;
2314                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2315
2316                 c = strndup_user(data->client_addr.data, 16);
2317                 if (IS_ERR(c))
2318                         return PTR_ERR(c);
2319                 args->client_address = c;
2320
2321                 /*
2322                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2323                  * can deal with.
2324                  */
2325
2326                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2327                 args->rsize     = data->rsize;
2328                 args->wsize     = data->wsize;
2329                 args->timeo     = data->timeo;
2330                 args->retrans   = data->retrans;
2331                 args->acregmin  = data->acregmin;
2332                 args->acregmax  = data->acregmax;
2333                 args->acdirmin  = data->acdirmin;
2334                 args->acdirmax  = data->acdirmax;
2335                 args->nfs_server.protocol = data->proto;
2336                 nfs_validate_transport_protocol(args);
2337
2338                 break;
2339         default: {
2340                 int status;
2341
2342                 if (nfs_parse_mount_options((char *)options, args) == 0)
2343                         return -EINVAL;
2344
2345                 if (!nfs_verify_server_address((struct sockaddr *)
2346                                                 &args->nfs_server.address))
2347                         return -EINVAL;
2348
2349                 rpc_set_port((struct sockaddr *)&args->nfs_server.address,
2350                                 args->nfs_server.port);
2351
2352                 nfs_validate_transport_protocol(args);
2353
2354                 nfs4_validate_mount_flags(args);
2355
2356                 if (args->auth_flavor_len > 1)
2357                         goto out_inval_auth;
2358
2359                 if (args->client_address == NULL)
2360                         goto out_no_client_address;
2361
2362                 status = nfs_parse_devname(dev_name,
2363                                            &args->nfs_server.hostname,
2364                                            NFS4_MAXNAMLEN,
2365                                            &args->nfs_server.export_path,
2366                                            NFS4_MAXPATHLEN);
2367                 if (status < 0)
2368                         return status;
2369
2370                 break;
2371                 }
2372         }
2373
2374         return 0;
2375
2376 out_no_data:
2377         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2378         return -EINVAL;
2379
2380 out_inval_auth:
2381         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2382                  data->auth_flavourlen);
2383         return -EINVAL;
2384
2385 out_no_address:
2386         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2387         return -EINVAL;
2388
2389 out_no_client_address:
2390         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2391         return -EINVAL;
2392 }
2393
2394 /*
2395  * Get the superblock for the NFS4 root partition
2396  */
2397 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2398         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2399 {
2400         struct nfs_parsed_mount_data *data = raw_data;
2401         struct super_block *s;
2402         struct nfs_server *server;
2403         struct nfs_fh *mntfh;
2404         struct dentry *mntroot;
2405         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2406         struct nfs_sb_mountdata sb_mntdata = {
2407                 .mntflags = flags,
2408         };
2409         int error = -ENOMEM;
2410
2411         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2412         if (data == NULL || mntfh == NULL)
2413                 goto out_free_fh;
2414
2415         security_init_mnt_opts(&data->lsm_opts);
2416
2417         /* Get a volume representation */
2418         server = nfs4_create_server(data, mntfh);
2419         if (IS_ERR(server)) {
2420                 error = PTR_ERR(server);
2421                 goto out;
2422         }
2423         sb_mntdata.server = server;
2424
2425         if (server->flags & NFS4_MOUNT_UNSHARED)
2426                 compare_super = NULL;
2427
2428         /* Get a superblock - note that we may end up sharing one that already exists */
2429         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2430         if (IS_ERR(s)) {
2431                 error = PTR_ERR(s);
2432                 goto out_free;
2433         }
2434
2435         if (s->s_fs_info != server) {
2436                 nfs_free_server(server);
2437                 server = NULL;
2438         } else {
2439                 error = nfs_bdi_register(server);
2440                 if (error)
2441                         goto error_splat_super;
2442         }
2443
2444         if (!s->s_root) {
2445                 /* initial superblock/root creation */
2446                 nfs4_fill_super(s);
2447                 nfs_fscache_get_super_cookie(s, data);
2448         }
2449
2450         mntroot = nfs4_get_root(s, mntfh);
2451         if (IS_ERR(mntroot)) {
2452                 error = PTR_ERR(mntroot);
2453                 goto error_splat_super;
2454         }
2455
2456         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2457         if (error)
2458                 goto error_splat_root;
2459
2460         s->s_flags |= MS_ACTIVE;
2461         mnt->mnt_sb = s;
2462         mnt->mnt_root = mntroot;
2463         error = 0;
2464
2465 out:
2466         security_free_mnt_opts(&data->lsm_opts);
2467 out_free_fh:
2468         kfree(mntfh);
2469         return error;
2470
2471 out_free:
2472         nfs_free_server(server);
2473         goto out;
2474
2475 error_splat_root:
2476         dput(mntroot);
2477 error_splat_super:
2478         deactivate_locked_super(s);
2479         goto out;
2480 }
2481
2482 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2483                 int flags, void *data, const char *hostname)
2484 {
2485         struct vfsmount *root_mnt;
2486         char *root_devname;
2487         size_t len;
2488
2489         len = strlen(hostname) + 3;
2490         root_devname = kmalloc(len, GFP_KERNEL);
2491         if (root_devname == NULL)
2492                 return ERR_PTR(-ENOMEM);
2493         snprintf(root_devname, len, "%s:/", hostname);
2494         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2495         kfree(root_devname);
2496         return root_mnt;
2497 }
2498
2499 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2500 {
2501         char *page = (char *) __get_free_page(GFP_KERNEL);
2502         char *devname, *tmp;
2503
2504         if (page == NULL)
2505                 return;
2506         devname = nfs_path(path->mnt->mnt_devname,
2507                         path->mnt->mnt_root, path->dentry,
2508                         page, PAGE_SIZE);
2509         if (devname == NULL)
2510                 goto out_freepage;
2511         tmp = kstrdup(devname, GFP_KERNEL);
2512         if (tmp == NULL)
2513                 goto out_freepage;
2514         kfree(mnt->mnt_devname);
2515         mnt->mnt_devname = tmp;
2516 out_freepage:
2517         free_page((unsigned long)page);
2518 }
2519
2520 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2521                 const char *export_path, struct vfsmount *mnt_target)
2522 {
2523         struct mnt_namespace *ns_private;
2524         struct nameidata nd;
2525         struct super_block *s;
2526         int ret;
2527
2528         ns_private = create_mnt_ns(root_mnt);
2529         ret = PTR_ERR(ns_private);
2530         if (IS_ERR(ns_private))
2531                 goto out_mntput;
2532
2533         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2534                         export_path, LOOKUP_FOLLOW, &nd);
2535
2536         put_mnt_ns(ns_private);
2537
2538         if (ret != 0)
2539                 goto out_err;
2540
2541         s = nd.path.mnt->mnt_sb;
2542         atomic_inc(&s->s_active);
2543         mnt_target->mnt_sb = s;
2544         mnt_target->mnt_root = dget(nd.path.dentry);
2545
2546         /* Correct the device pathname */
2547         nfs_fix_devname(&nd.path, mnt_target);
2548
2549         path_put(&nd.path);
2550         down_write(&s->s_umount);
2551         return 0;
2552 out_mntput:
2553         mntput(root_mnt);
2554 out_err:
2555         return ret;
2556 }
2557
2558 /*
2559  * Get the superblock for an NFS4 mountpoint
2560  */
2561 static int nfs4_get_sb(struct file_system_type *fs_type,
2562         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2563 {
2564         struct nfs_parsed_mount_data *data;
2565         char *export_path;
2566         struct vfsmount *root_mnt;
2567         int error = -ENOMEM;
2568
2569         data = kzalloc(sizeof(*data), GFP_KERNEL);
2570         if (data == NULL)
2571                 goto out_free_data;
2572
2573         /* Validate the mount data */
2574         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2575         if (error < 0)
2576                 goto out;
2577
2578         export_path = data->nfs_server.export_path;
2579         data->nfs_server.export_path = "/";
2580         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2581                         data->nfs_server.hostname);
2582         data->nfs_server.export_path = export_path;
2583
2584         error = PTR_ERR(root_mnt);
2585         if (IS_ERR(root_mnt))
2586                 goto out;
2587
2588         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2589
2590 out:
2591         kfree(data->client_address);
2592         kfree(data->nfs_server.export_path);
2593         kfree(data->nfs_server.hostname);
2594         kfree(data->fscache_uniq);
2595 out_free_data:
2596         kfree(data);
2597         dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2598                         error != 0 ? " [error]" : "");
2599         return error;
2600 }
2601
2602 static void nfs4_kill_super(struct super_block *sb)
2603 {
2604         struct nfs_server *server = NFS_SB(sb);
2605
2606         dprintk("--> %s\n", __func__);
2607         nfs_super_return_all_delegations(sb);
2608         kill_anon_super(sb);
2609         nfs4_renewd_prepare_shutdown(server);
2610         nfs_fscache_release_super_cookie(sb);
2611         nfs_free_server(server);
2612         dprintk("<-- %s\n", __func__);
2613 }
2614
2615 /*
2616  * Clone an NFS4 server record on xdev traversal (FSID-change)
2617  */
2618 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2619                             const char *dev_name, void *raw_data,
2620                             struct vfsmount *mnt)
2621 {
2622         struct nfs_clone_mount *data = raw_data;
2623         struct super_block *s;
2624         struct nfs_server *server;
2625         struct dentry *mntroot;
2626         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2627         struct nfs_sb_mountdata sb_mntdata = {
2628                 .mntflags = flags,
2629         };
2630         int error;
2631
2632         dprintk("--> nfs4_xdev_get_sb()\n");
2633
2634         /* create a new volume representation */
2635         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2636         if (IS_ERR(server)) {
2637                 error = PTR_ERR(server);
2638                 goto out_err_noserver;
2639         }
2640         sb_mntdata.server = server;
2641
2642         if (server->flags & NFS4_MOUNT_UNSHARED)
2643                 compare_super = NULL;
2644
2645         /* Get a superblock - note that we may end up sharing one that already exists */
2646         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2647         if (IS_ERR(s)) {
2648                 error = PTR_ERR(s);
2649                 goto out_err_nosb;
2650         }
2651
2652         if (s->s_fs_info != server) {
2653                 nfs_free_server(server);
2654                 server = NULL;
2655         } else {
2656                 error = nfs_bdi_register(server);
2657                 if (error)
2658                         goto error_splat_super;
2659         }
2660
2661         if (!s->s_root) {
2662                 /* initial superblock/root creation */
2663                 nfs4_clone_super(s, data->sb);
2664         }
2665
2666         mntroot = nfs4_get_root(s, data->fh);
2667         if (IS_ERR(mntroot)) {
2668                 error = PTR_ERR(mntroot);
2669                 goto error_splat_super;
2670         }
2671         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2672                 dput(mntroot);
2673                 error = -ESTALE;
2674                 goto error_splat_super;
2675         }
2676
2677         s->s_flags |= MS_ACTIVE;
2678         mnt->mnt_sb = s;
2679         mnt->mnt_root = mntroot;
2680
2681         security_sb_clone_mnt_opts(data->sb, s);
2682
2683         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2684         return 0;
2685
2686 out_err_nosb:
2687         nfs_free_server(server);
2688 out_err_noserver:
2689         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2690         return error;
2691
2692 error_splat_super:
2693         deactivate_locked_super(s);
2694         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2695         return error;
2696 }
2697
2698 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2699                 int flags, const char *dev_name, void *raw_data,
2700                 struct vfsmount *mnt)
2701 {
2702         struct nfs_clone_mount *data = raw_data;
2703         struct super_block *s;
2704         struct nfs_server *server;
2705         struct dentry *mntroot;
2706         struct nfs_fh mntfh;
2707         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2708         struct nfs_sb_mountdata sb_mntdata = {
2709                 .mntflags = flags,
2710         };
2711         int error;
2712
2713         dprintk("--> nfs4_referral_get_sb()\n");
2714
2715         /* create a new volume representation */
2716         server = nfs4_create_referral_server(data, &mntfh);
2717         if (IS_ERR(server)) {
2718                 error = PTR_ERR(server);
2719                 goto out_err_noserver;
2720         }
2721         sb_mntdata.server = server;
2722
2723         if (server->flags & NFS4_MOUNT_UNSHARED)
2724                 compare_super = NULL;
2725
2726         /* Get a superblock - note that we may end up sharing one that already exists */
2727         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2728         if (IS_ERR(s)) {
2729                 error = PTR_ERR(s);
2730                 goto out_err_nosb;
2731         }
2732
2733         if (s->s_fs_info != server) {
2734                 nfs_free_server(server);
2735                 server = NULL;
2736         } else {
2737                 error = nfs_bdi_register(server);
2738                 if (error)
2739                         goto error_splat_super;
2740         }
2741
2742         if (!s->s_root) {
2743                 /* initial superblock/root creation */
2744                 nfs4_fill_super(s);
2745         }
2746
2747         mntroot = nfs4_get_root(s, &mntfh);
2748         if (IS_ERR(mntroot)) {
2749                 error = PTR_ERR(mntroot);
2750                 goto error_splat_super;
2751         }
2752         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2753                 dput(mntroot);
2754                 error = -ESTALE;
2755                 goto error_splat_super;
2756         }
2757
2758         s->s_flags |= MS_ACTIVE;
2759         mnt->mnt_sb = s;
2760         mnt->mnt_root = mntroot;
2761
2762         security_sb_clone_mnt_opts(data->sb, s);
2763
2764         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2765         return 0;
2766
2767 out_err_nosb:
2768         nfs_free_server(server);
2769 out_err_noserver:
2770         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2771         return error;
2772
2773 error_splat_super:
2774         deactivate_locked_super(s);
2775         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2776         return error;
2777 }
2778
2779 /*
2780  * Create an NFS4 server record on referral traversal
2781  */
2782 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2783                 int flags, const char *dev_name, void *raw_data,
2784                 struct vfsmount *mnt)
2785 {
2786         struct nfs_clone_mount *data = raw_data;
2787         char *export_path;
2788         struct vfsmount *root_mnt;
2789         int error;
2790
2791         dprintk("--> nfs4_referral_get_sb()\n");
2792
2793         export_path = data->mnt_path;
2794         data->mnt_path = "/";
2795
2796         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2797                         flags, data, data->hostname);
2798         data->mnt_path = export_path;
2799
2800         error = PTR_ERR(root_mnt);
2801         if (IS_ERR(root_mnt))
2802                 goto out;
2803
2804         error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2805 out:
2806         dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2807                         error != 0 ? " [error]" : "");
2808         return error;
2809 }
2810
2811 #endif /* CONFIG_NFS_V4 */