fs/nfsd/nfsfh.c

   1 /*
   2  * linux/fs/nfsd/nfsfh.c
   3  *
   4  * NFS server file handle treatment.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
   8  * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
   9  * ... and again Southern-Winter 2001 to support export_operations
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/fs.h>
  14 #include <linux/unistd.h>
  15 #include <linux/string.h>
  16 #include <linux/stat.h>
  17 #include <linux/dcache.h>
  18 #include <linux/exportfs.h>
  19 #include <linux/mount.h>
  20
  21 #include <linux/sunrpc/clnt.h>
  22 #include <linux/sunrpc/svc.h>
  23 #include <linux/sunrpc/svcauth_gss.h>
  24 #include <linux/nfsd/nfsd.h>
  25 #include "auth.h"
  26
  27 #define NFSDDBG_FACILITY                NFSDDBG_FH
  28
  29
  30 static int nfsd_nr_verified;
  31 static int nfsd_nr_put;
  32
  33 /*
  34  * our acceptability function.
  35  * if NOSUBTREECHECK, accept anything
  36  * if not, require that we can walk up to exp->ex_dentry
  37  * doing some checks on the 'x' bits
  38  */
  39 static int nfsd_acceptable(void *expv, struct dentry *dentry)
  40 {
  41         struct svc_export *exp = expv;
  42         int rv;
  43         struct dentry *tdentry;
  44         struct dentry *parent;
  45
  46         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
  47                 return 1;
  48
  49         tdentry = dget(dentry);
  50         while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
  51                 /* make sure parents give x permission to user */
  52                 int err;
  53                 parent = dget_parent(tdentry);
  54                 err = inode_permission(parent->d_inode, MAY_EXEC);
  55                 if (err < 0) {
  56                         dput(parent);
  57                         break;
  58                 }
  59                 dput(tdentry);
  60                 tdentry = parent;
  61         }
  62         if (tdentry != exp->ex_path.dentry)
  63                 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
  64         rv = (tdentry == exp->ex_path.dentry);
  65         dput(tdentry);
  66         return rv;
  67 }
  68
  69 /* Type check. The correct error return for type mismatches does not seem to be
  70  * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
  71  * comment in the NFSv3 spec says this is incorrect (implementation notes for
  72  * the write call).
  73  */
  74 static inline __be32
  75 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
  76 {
  77         /* Type can be negative when creating hardlinks - not to a dir */
  78         if (type > 0 && (mode & S_IFMT) != type) {
  79                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
  80                         return nfserr_symlink;
  81                 else if (type == S_IFDIR)
  82                         return nfserr_notdir;
  83                 else if ((mode & S_IFMT) == S_IFDIR)
  84                         return nfserr_isdir;
  85                 else
  86                         return nfserr_inval;
  87         }
  88         if (type < 0 && (mode & S_IFMT) == -type) {
  89                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
  90                         return nfserr_symlink;
  91                 else if (type == -S_IFDIR)
  92                         return nfserr_isdir;
  93                 else
  94                         return nfserr_notdir;
  95         }
  96         return 0;
  97 }
  98
  99 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
 100                                           struct svc_export *exp)
 101 {
 102         /* Check if the request originated from a secure port. */
 103         if (!rqstp->rq_secure && EX_SECURE(exp)) {
 104                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 105                 dprintk(KERN_WARNING
 106                        "nfsd: request from insecure port %s!\n",
 107                        svc_print_addr(rqstp, buf, sizeof(buf)));
 108                 return nfserr_perm;
 109         }
 110
 111         /* Set user creds for this exportpoint */
 112         return nfserrno(nfsd_setuser(rqstp, exp));
 113 }
 114
 115 /*
 116  * Use the given filehandle to look up the corresponding export and
 117  * dentry.  On success, the results are used to set fh_export and
 118  * fh_dentry.
 119  */
 120 static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
 121 {
 122         struct knfsd_fh *fh = &fhp->fh_handle;
 123         struct fid *fid = NULL, sfid;
 124         struct svc_export *exp;
 125         struct dentry *dentry;
 126         int fileid_type;
 127         int data_left = fh->fh_size/4;
 128         __be32 error;
 129
 130         error = nfserr_stale;
 131         if (rqstp->rq_vers > 2)
 132                 error = nfserr_badhandle;
 133         if (rqstp->rq_vers == 4 && fh->fh_size == 0)
 134                 return nfserr_nofilehandle;
 135
 136         if (fh->fh_version == 1) {
 137                 int len;
 138
 139                 if (--data_left < 0)
 140                         return error;
 141                 if (fh->fh_auth_type != 0)
 142                         return error;
 143                 len = key_len(fh->fh_fsid_type) / 4;
 144                 if (len == 0)
 145                         return error;
 146                 if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
 147                         /* deprecated, convert to type 3 */
 148                         len = key_len(FSID_ENCODE_DEV)/4;
 149                         fh->fh_fsid_type = FSID_ENCODE_DEV;
 150                         fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
 151                         fh->fh_fsid[1] = fh->fh_fsid[2];
 152                 }
 153                 data_left -= len;
 154                 if (data_left < 0)
 155                         return error;
 156                 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
 157                 fid = (struct fid *)(fh->fh_auth + len);
 158         } else {
 159                 __u32 tfh[2];
 160                 dev_t xdev;
 161                 ino_t xino;
 162
 163                 if (fh->fh_size != NFS_FHSIZE)
 164                         return error;
 165                 /* assume old filehandle format */
 166                 xdev = old_decode_dev(fh->ofh_xdev);
 167                 xino = u32_to_ino_t(fh->ofh_xino);
 168                 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
 169                 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
 170         }
 171
 172         error = nfserr_stale;
 173         if (PTR_ERR(exp) == -ENOENT)
 174                 return error;
 175
 176         if (IS_ERR(exp))
 177                 return nfserrno(PTR_ERR(exp));
 178
 179         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
 180                 /* Elevate privileges so that the lack of 'r' or 'x'
 181                  * permission on some parent directory will
 182                  * not stop exportfs_decode_fh from being able
 183                  * to reconnect a directory into the dentry cache.
 184                  * The same problem can affect "SUBTREECHECK" exports,
 185                  * but as nfsd_acceptable depends on correct
 186                  * access control settings being in effect, we cannot
 187                  * fix that case easily.
 188                  */
 189                 struct cred *new = prepare_creds();
 190                 if (!new)
 191                         return nfserrno(-ENOMEM);
 192                 new->cap_effective =
 193                         cap_raise_nfsd_set(new->cap_effective,
 194                                            new->cap_permitted);
 195                 put_cred(override_creds(new));
 196                 put_cred(new);
 197         } else {
 198                 error = nfsd_setuser_and_check_port(rqstp, exp);
 199                 if (error)
 200                         goto out;
 201         }
 202
 203         /*
 204          * Look up the dentry using the NFS file handle.
 205          */
 206         error = nfserr_stale;
 207         if (rqstp->rq_vers > 2)
 208                 error = nfserr_badhandle;
 209
 210         if (fh->fh_version != 1) {
 211                 sfid.i32.ino = fh->ofh_ino;
 212                 sfid.i32.gen = fh->ofh_generation;
 213                 sfid.i32.parent_ino = fh->ofh_dirino;
 214                 fid = &sfid;
 215                 data_left = 3;
 216                 if (fh->ofh_dirino == 0)
 217                         fileid_type = FILEID_INO32_GEN;
 218                 else
 219                         fileid_type = FILEID_INO32_GEN_PARENT;
 220         } else
 221                 fileid_type = fh->fh_fileid_type;
 222
 223         if (fileid_type == FILEID_ROOT)
 224                 dentry = dget(exp->ex_path.dentry);
 225         else {
 226                 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
 227                                 data_left, fileid_type,
 228                                 nfsd_acceptable, exp);
 229         }
 230         if (dentry == NULL)
 231                 goto out;
 232         if (IS_ERR(dentry)) {
 233                 if (PTR_ERR(dentry) != -EINVAL)
 234                         error = nfserrno(PTR_ERR(dentry));
 235                 goto out;
 236         }
 237
 238         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
 239                 error = nfsd_setuser_and_check_port(rqstp, exp);
 240                 if (error) {
 241                         dput(dentry);
 242                         goto out;
 243                 }
 244         }
 245
 246         if (S_ISDIR(dentry->d_inode->i_mode) &&
 247                         (dentry->d_flags & DCACHE_DISCONNECTED)) {
 248                 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
 249                                 dentry->d_parent->d_name.name, dentry->d_name.name);
 250         }
 251
 252         fhp->fh_dentry = dentry;
 253         fhp->fh_export = exp;
 254         nfsd_nr_verified++;
 255         return 0;
 256 out:
 257         exp_put(exp);
 258         return error;
 259 }
 260
 261 /**
 262  * fh_verify - filehandle lookup and access checking
 263  * @rqstp: pointer to current rpc request
 264  * @fhp: filehandle to be verified
 265  * @type: expected type of object pointed to by filehandle
 266  * @access: type of access needed to object
 267  *
 268  * Look up a dentry from the on-the-wire filehandle, check the client's
 269  * access to the export, and set the current task's credentials.
 270  *
 271  * Regardless of success or failure of fh_verify(), fh_put() should be
 272  * called on @fhp when the caller is finished with the filehandle.
 273  *
 274  * fh_verify() may be called multiple times on a given filehandle, for
 275  * example, when processing an NFSv4 compound.  The first call will look
 276  * up a dentry using the on-the-wire filehandle.  Subsequent calls will
 277  * skip the lookup and just perform the other checks and possibly change
 278  * the current task's credentials.
 279  *
 280  * @type specifies the type of object expected using one of the S_IF*
 281  * constants defined in include/linux/stat.h.  The caller may use zero
 282  * to indicate that it doesn't care, or a negative integer to indicate
 283  * that it expects something not of the given type.
 284  *
 285  * @access is formed from the NFSD_MAY_* constants defined in
 286  * include/linux/nfsd/nfsd.h.
 287  */
 288 __be32
 289 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
 290 {
 291         struct svc_export *exp;
 292         struct dentry   *dentry;
 293         __be32          error;
 294
 295         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
 296
 297         if (!fhp->fh_dentry) {
 298                 error = nfsd_set_fh_dentry(rqstp, fhp);
 299                 if (error)
 300                         goto out;
 301                 dentry = fhp->fh_dentry;
 302                 exp = fhp->fh_export;
 303         } else {
 304                 /*
 305                  * just rechecking permissions
 306                  * (e.g. nfsproc_create calls fh_verify, then nfsd_create
 307                  * does as well)
 308                  */
 309                 dprintk("nfsd: fh_verify - just checking\n");
 310                 dentry = fhp->fh_dentry;
 311                 exp = fhp->fh_export;
 312                 /*
 313                  * Set user creds for this exportpoint; necessary even
 314                  * in the "just checking" case because this may be a
 315                  * filehandle that was created by fh_compose, and that
 316                  * is about to be used in another nfsv4 compound
 317                  * operation.
 318                  */
 319                 error = nfsd_setuser_and_check_port(rqstp, exp);
 320                 if (error)
 321                         goto out;
 322         }
 323
 324         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
 325         if (error)
 326                 goto out;
 327
 328         /*
 329          * pseudoflavor restrictions are not enforced on NLM,
 330          * which clients virtually always use auth_sys for,
 331          * even while using RPCSEC_GSS for NFS.
 332          */
 333         if (access & NFSD_MAY_LOCK)
 334                 goto skip_pseudoflavor_check;
 335         /*
 336          * Clients may expect to be able to use auth_sys during mount,
 337          * even if they use gss for everything else; see section 2.3.2
 338          * of rfc 2623.
 339          */
 340         if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
 341                         && exp->ex_path.dentry == dentry)
 342                 goto skip_pseudoflavor_check;
 343
 344         error = check_nfsd_access(exp, rqstp);
 345         if (error)
 346                 goto out;
 347
 348 skip_pseudoflavor_check:
 349         /* Finally, check access permissions. */
 350         error = nfsd_permission(rqstp, exp, dentry, access);
 351
 352         if (error) {
 353                 dprintk("fh_verify: %s/%s permission failure, "
 354                         "acc=%x, error=%d\n",
 355                         dentry->d_parent->d_name.name,
 356                         dentry->d_name.name,
 357                         access, ntohl(error));
 358         }
 359 out:
 360         if (error == nfserr_stale)
 361                 nfsdstats.fh_stale++;
 362         return error;
 363 }
 364
 365
 366 /*
 367  * Compose a file handle for an NFS reply.
 368  *
 369  * Note that when first composed, the dentry may not yet have
 370  * an inode.  In this case a call to fh_update should be made
 371  * before the fh goes out on the wire ...
 372  */
 373 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
 374                 struct dentry *dentry)
 375 {
 376         if (dentry != exp->ex_path.dentry) {
 377                 struct fid *fid = (struct fid *)
 378                         (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
 379                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
 380                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
 381
 382                 fhp->fh_handle.fh_fileid_type =
 383                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
 384                 fhp->fh_handle.fh_size += maxsize * 4;
 385         } else {
 386                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
 387         }
 388 }
 389
 390 /*
 391  * for composing old style file handles
 392  */
 393 static inline void _fh_update_old(struct dentry *dentry,
 394                                   struct svc_export *exp,
 395                                   struct knfsd_fh *fh)
 396 {
 397         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
 398         fh->ofh_generation = dentry->d_inode->i_generation;
 399         if (S_ISDIR(dentry->d_inode->i_mode) ||
 400             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
 401                 fh->ofh_dirino = 0;
 402 }
 403
 404 __be32
 405 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
 406            struct svc_fh *ref_fh)
 407 {
 408         /* ref_fh is a reference file handle.
 409          * if it is non-null and for the same filesystem, then we should compose
 410          * a filehandle which is of the same version, where possible.
 411          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
 412          * Then create a 32byte filehandle using nfs_fhbase_old
 413          *
 414          */
 415
 416         u8 version;
 417         u8 fsid_type = 0;
 418         struct inode * inode = dentry->d_inode;
 419         struct dentry *parent = dentry->d_parent;
 420         __u32 *datap;
 421         dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
 422         int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
 423
 424         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
 425                 MAJOR(ex_dev), MINOR(ex_dev),
 426                 (long) exp->ex_path.dentry->d_inode->i_ino,
 427                 parent->d_name.name, dentry->d_name.name,
 428                 (inode ? inode->i_ino : 0));
 429
 430         /* Choose filehandle version and fsid type based on
 431          * the reference filehandle (if it is in the same export)
 432          * or the export options.
 433          */
 434  retry:
 435         version = 1;
 436         if (ref_fh && ref_fh->fh_export == exp) {
 437                 version = ref_fh->fh_handle.fh_version;
 438                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
 439
 440                 if (ref_fh == fhp)
 441                         fh_put(ref_fh);
 442                 ref_fh = NULL;
 443
 444                 switch (version) {
 445                 case 0xca:
 446                         fsid_type = FSID_DEV;
 447                         break;
 448                 case 1:
 449                         break;
 450                 default:
 451                         goto retry;
 452                 }
 453
 454                 /* Need to check that this type works for this
 455                  * export point.  As the fsid -> filesystem mapping
 456                  * was guided by user-space, there is no guarantee
 457                  * that the filesystem actually supports that fsid
 458                  * type. If it doesn't we loop around again without
 459                  * ref_fh set.
 460                  */
 461                 switch(fsid_type) {
 462                 case FSID_DEV:
 463                         if (!old_valid_dev(ex_dev))
 464                                 goto retry;
 465                         /* FALL THROUGH */
 466                 case FSID_MAJOR_MINOR:
 467                 case FSID_ENCODE_DEV:
 468                         if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 469                               & FS_REQUIRES_DEV))
 470                                 goto retry;
 471                         break;
 472                 case FSID_NUM:
 473                         if (! (exp->ex_flags & NFSEXP_FSID))
 474                                 goto retry;
 475                         break;
 476                 case FSID_UUID8:
 477                 case FSID_UUID16:
 478                         if (!root_export)
 479                                 goto retry;
 480                         /* fall through */
 481                 case FSID_UUID4_INUM:
 482                 case FSID_UUID16_INUM:
 483                         if (exp->ex_uuid == NULL)
 484                                 goto retry;
 485                         break;
 486                 }
 487         } else if (exp->ex_flags & NFSEXP_FSID) {
 488                 fsid_type = FSID_NUM;
 489         } else if (exp->ex_uuid) {
 490                 if (fhp->fh_maxsize >= 64) {
 491                         if (root_export)
 492                                 fsid_type = FSID_UUID16;
 493                         else
 494                                 fsid_type = FSID_UUID16_INUM;
 495                 } else {
 496                         if (root_export)
 497                                 fsid_type = FSID_UUID8;
 498                         else
 499                                 fsid_type = FSID_UUID4_INUM;
 500                 }
 501         } else if (!old_valid_dev(ex_dev))
 502                 /* for newer device numbers, we must use a newer fsid format */
 503                 fsid_type = FSID_ENCODE_DEV;
 504         else
 505                 fsid_type = FSID_DEV;
 506
 507         if (ref_fh == fhp)
 508                 fh_put(ref_fh);
 509
 510         if (fhp->fh_locked || fhp->fh_dentry) {
 511                 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
 512                        parent->d_name.name, dentry->d_name.name);
 513         }
 514         if (fhp->fh_maxsize < NFS_FHSIZE)
 515                 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
 516                        fhp->fh_maxsize,
 517                        parent->d_name.name, dentry->d_name.name);
 518
 519         fhp->fh_dentry = dget(dentry); /* our internal copy */
 520         fhp->fh_export = exp;
 521         cache_get(&exp->h);
 522
 523         if (version == 0xca) {
 524                 /* old style filehandle please */
 525                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
 526                 fhp->fh_handle.fh_size = NFS_FHSIZE;
 527                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
 528                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
 529                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
 530                 fhp->fh_handle.ofh_xino =
 531                         ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
 532                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
 533                 if (inode)
 534                         _fh_update_old(dentry, exp, &fhp->fh_handle);
 535         } else {
 536                 int len;
 537                 fhp->fh_handle.fh_version = 1;
 538                 fhp->fh_handle.fh_auth_type = 0;
 539                 datap = fhp->fh_handle.fh_auth+0;
 540                 fhp->fh_handle.fh_fsid_type = fsid_type;
 541                 mk_fsid(fsid_type, datap, ex_dev,
 542                         exp->ex_path.dentry->d_inode->i_ino,
 543                         exp->ex_fsid, exp->ex_uuid);
 544
 545                 len = key_len(fsid_type);
 546                 datap += len/4;
 547                 fhp->fh_handle.fh_size = 4 + len;
 548
 549                 if (inode)
 550                         _fh_update(fhp, exp, dentry);
 551                 if (fhp->fh_handle.fh_fileid_type == 255)
 552                         return nfserr_opnotsupp;
 553         }
 554
 555         nfsd_nr_verified++;
 556         return 0;
 557 }
 558
 559 /*
 560  * Update file handle information after changing a dentry.
 561  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
 562  */
 563 __be32
 564 fh_update(struct svc_fh *fhp)
 565 {
 566         struct dentry *dentry;
 567
 568         if (!fhp->fh_dentry)
 569                 goto out_bad;
 570
 571         dentry = fhp->fh_dentry;
 572         if (!dentry->d_inode)
 573                 goto out_negative;
 574         if (fhp->fh_handle.fh_version != 1) {
 575                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
 576         } else {
 577                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
 578                         goto out;
 579
 580                 _fh_update(fhp, fhp->fh_export, dentry);
 581                 if (fhp->fh_handle.fh_fileid_type == 255)
 582                         return nfserr_opnotsupp;
 583         }
 584 out:
 585         return 0;
 586
 587 out_bad:
 588         printk(KERN_ERR "fh_update: fh not verified!\n");
 589         goto out;
 590 out_negative:
 591         printk(KERN_ERR "fh_update: %s/%s still negative!\n",
 592                 dentry->d_parent->d_name.name, dentry->d_name.name);
 593         goto out;
 594 }
 595
 596 /*
 597  * Release a file handle.
 598  */
 599 void
 600 fh_put(struct svc_fh *fhp)
 601 {
 602         struct dentry * dentry = fhp->fh_dentry;
 603         struct svc_export * exp = fhp->fh_export;
 604         if (dentry) {
 605                 fh_unlock(fhp);
 606                 fhp->fh_dentry = NULL;
 607                 dput(dentry);
 608 #ifdef CONFIG_NFSD_V3
 609                 fhp->fh_pre_saved = 0;
 610                 fhp->fh_post_saved = 0;
 611 #endif
 612                 nfsd_nr_put++;
 613         }
 614         if (exp) {
 615                 cache_put(&exp->h, &svc_export_cache);
 616                 fhp->fh_export = NULL;
 617         }
 618         return;
 619 }
 620
 621 /*
 622  * Shorthand for dprintk()'s
 623  */
 624 char * SVCFH_fmt(struct svc_fh *fhp)
 625 {
 626         struct knfsd_fh *fh = &fhp->fh_handle;
 627
 628         static char buf[80];
 629         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
 630                 fh->fh_size,
 631                 fh->fh_base.fh_pad[0],
 632                 fh->fh_base.fh_pad[1],
 633                 fh->fh_base.fh_pad[2],
 634                 fh->fh_base.fh_pad[3],
 635                 fh->fh_base.fh_pad[4],
 636                 fh->fh_base.fh_pad[5]);
 637         return buf;
 638 }
 639
 640 enum fsid_source fsid_source(struct svc_fh *fhp)
 641 {
 642         if (fhp->fh_handle.fh_version != 1)
 643                 return FSIDSOURCE_DEV;
 644         switch(fhp->fh_handle.fh_fsid_type) {
 645         case FSID_DEV:
 646         case FSID_ENCODE_DEV:
 647         case FSID_MAJOR_MINOR:
 648                 if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 649                     & FS_REQUIRES_DEV)
 650                         return FSIDSOURCE_DEV;
 651                 break;
 652         case FSID_NUM:
 653                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 654                         return FSIDSOURCE_FSID;
 655                 break;
 656         default:
 657                 break;
 658         }
 659         /* either a UUID type filehandle, or the filehandle doesn't
 660          * match the export.
 661          */
 662         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 663                 return FSIDSOURCE_FSID;
 664         if (fhp->fh_export->ex_uuid)
 665                 return FSIDSOURCE_UUID;
 666         return FSIDSOURCE_DEV;
 667 }