git.oblomov.eu Git - linux-2.6/blob - 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                 current->cap_effective =
 190                         cap_raise_nfsd_set(current->cap_effective,
 191                                            current->cap_permitted);
 192         } else {
 193                 error = nfsd_setuser_and_check_port(rqstp, exp);
 194                 if (error)
 195                         goto out;
 196         }
 197
 198         /*
 199          * Look up the dentry using the NFS file handle.
 200          */
 201         error = nfserr_stale;
 202         if (rqstp->rq_vers > 2)
 203                 error = nfserr_badhandle;
 204
 205         if (fh->fh_version != 1) {
 206                 sfid.i32.ino = fh->ofh_ino;
 207                 sfid.i32.gen = fh->ofh_generation;
 208                 sfid.i32.parent_ino = fh->ofh_dirino;
 209                 fid = &sfid;
 210                 data_left = 3;
 211                 if (fh->ofh_dirino == 0)
 212                         fileid_type = FILEID_INO32_GEN;
 213                 else
 214                         fileid_type = FILEID_INO32_GEN_PARENT;
 215         } else
 216                 fileid_type = fh->fh_fileid_type;
 217
 218         if (fileid_type == FILEID_ROOT)
 219                 dentry = dget(exp->ex_path.dentry);
 220         else {
 221                 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
 222                                 data_left, fileid_type,
 223                                 nfsd_acceptable, exp);
 224         }
 225         if (dentry == NULL)
 226                 goto out;
 227         if (IS_ERR(dentry)) {
 228                 if (PTR_ERR(dentry) != -EINVAL)
 229                         error = nfserrno(PTR_ERR(dentry));
 230                 goto out;
 231         }
 232
 233         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
 234                 error = nfsd_setuser_and_check_port(rqstp, exp);
 235                 if (error) {
 236                         dput(dentry);
 237                         goto out;
 238                 }
 239         }
 240
 241         if (S_ISDIR(dentry->d_inode->i_mode) &&
 242                         (dentry->d_flags & DCACHE_DISCONNECTED)) {
 243                 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
 244                                 dentry->d_parent->d_name.name, dentry->d_name.name);
 245         }
 246
 247         fhp->fh_dentry = dentry;
 248         fhp->fh_export = exp;
 249         nfsd_nr_verified++;
 250         return 0;
 251 out:
 252         exp_put(exp);
 253         return error;
 254 }
 255
 256 /*
 257  * Perform sanity checks on the dentry in a client's file handle.
 258  *
 259  * Note that the file handle dentry may need to be freed even after
 260  * an error return.
 261  *
 262  * This is only called at the start of an nfsproc call, so fhp points to
 263  * a svc_fh which is all 0 except for the over-the-wire file handle.
 264  */
 265 __be32
 266 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
 267 {
 268         struct svc_export *exp;
 269         struct dentry   *dentry;
 270         __be32          error;
 271
 272         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
 273
 274         if (!fhp->fh_dentry) {
 275                 error = nfsd_set_fh_dentry(rqstp, fhp);
 276                 if (error)
 277                         goto out;
 278                 dentry = fhp->fh_dentry;
 279                 exp = fhp->fh_export;
 280         } else {
 281                 /*
 282                  * just rechecking permissions
 283                  * (e.g. nfsproc_create calls fh_verify, then nfsd_create
 284                  * does as well)
 285                  */
 286                 dprintk("nfsd: fh_verify - just checking\n");
 287                 dentry = fhp->fh_dentry;
 288                 exp = fhp->fh_export;
 289                 /*
 290                  * Set user creds for this exportpoint; necessary even
 291                  * in the "just checking" case because this may be a
 292                  * filehandle that was created by fh_compose, and that
 293                  * is about to be used in another nfsv4 compound
 294                  * operation.
 295                  */
 296                 error = nfsd_setuser_and_check_port(rqstp, exp);
 297                 if (error)
 298                         goto out;
 299         }
 300
 301         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
 302         if (error)
 303                 goto out;
 304
 305         if (!(access & NFSD_MAY_LOCK)) {
 306                 /*
 307                  * pseudoflavor restrictions are not enforced on NLM,
 308                  * which clients virtually always use auth_sys for,
 309                  * even while using RPCSEC_GSS for NFS.
 310                  */
 311                 error = check_nfsd_access(exp, rqstp);
 312                 if (error)
 313                         goto out;
 314         }
 315
 316         /* Finally, check access permissions. */
 317         error = nfsd_permission(rqstp, exp, dentry, access);
 318
 319         if (error) {
 320                 dprintk("fh_verify: %s/%s permission failure, "
 321                         "acc=%x, error=%d\n",
 322                         dentry->d_parent->d_name.name,
 323                         dentry->d_name.name,
 324                         access, ntohl(error));
 325         }
 326 out:
 327         if (error == nfserr_stale)
 328                 nfsdstats.fh_stale++;
 329         return error;
 330 }
 331
 332
 333 /*
 334  * Compose a file handle for an NFS reply.
 335  *
 336  * Note that when first composed, the dentry may not yet have
 337  * an inode.  In this case a call to fh_update should be made
 338  * before the fh goes out on the wire ...
 339  */
 340 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
 341                 struct dentry *dentry)
 342 {
 343         if (dentry != exp->ex_path.dentry) {
 344                 struct fid *fid = (struct fid *)
 345                         (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
 346                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
 347                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
 348
 349                 fhp->fh_handle.fh_fileid_type =
 350                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
 351                 fhp->fh_handle.fh_size += maxsize * 4;
 352         } else {
 353                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
 354         }
 355 }
 356
 357 /*
 358  * for composing old style file handles
 359  */
 360 static inline void _fh_update_old(struct dentry *dentry,
 361                                   struct svc_export *exp,
 362                                   struct knfsd_fh *fh)
 363 {
 364         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
 365         fh->ofh_generation = dentry->d_inode->i_generation;
 366         if (S_ISDIR(dentry->d_inode->i_mode) ||
 367             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
 368                 fh->ofh_dirino = 0;
 369 }
 370
 371 __be32
 372 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
 373            struct svc_fh *ref_fh)
 374 {
 375         /* ref_fh is a reference file handle.
 376          * if it is non-null and for the same filesystem, then we should compose
 377          * a filehandle which is of the same version, where possible.
 378          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
 379          * Then create a 32byte filehandle using nfs_fhbase_old
 380          *
 381          */
 382
 383         u8 version;
 384         u8 fsid_type = 0;
 385         struct inode * inode = dentry->d_inode;
 386         struct dentry *parent = dentry->d_parent;
 387         __u32 *datap;
 388         dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
 389         int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
 390
 391         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
 392                 MAJOR(ex_dev), MINOR(ex_dev),
 393                 (long) exp->ex_path.dentry->d_inode->i_ino,
 394                 parent->d_name.name, dentry->d_name.name,
 395                 (inode ? inode->i_ino : 0));
 396
 397         /* Choose filehandle version and fsid type based on
 398          * the reference filehandle (if it is in the same export)
 399          * or the export options.
 400          */
 401  retry:
 402         version = 1;
 403         if (ref_fh && ref_fh->fh_export == exp) {
 404                 version = ref_fh->fh_handle.fh_version;
 405                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
 406
 407                 if (ref_fh == fhp)
 408                         fh_put(ref_fh);
 409                 ref_fh = NULL;
 410
 411                 switch (version) {
 412                 case 0xca:
 413                         fsid_type = FSID_DEV;
 414                         break;
 415                 case 1:
 416                         break;
 417                 default:
 418                         goto retry;
 419                 }
 420
 421                 /* Need to check that this type works for this
 422                  * export point.  As the fsid -> filesystem mapping
 423                  * was guided by user-space, there is no guarantee
 424                  * that the filesystem actually supports that fsid
 425                  * type. If it doesn't we loop around again without
 426                  * ref_fh set.
 427                  */
 428                 switch(fsid_type) {
 429                 case FSID_DEV:
 430                         if (!old_valid_dev(ex_dev))
 431                                 goto retry;
 432                         /* FALL THROUGH */
 433                 case FSID_MAJOR_MINOR:
 434                 case FSID_ENCODE_DEV:
 435                         if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 436                               & FS_REQUIRES_DEV))
 437                                 goto retry;
 438                         break;
 439                 case FSID_NUM:
 440                         if (! (exp->ex_flags & NFSEXP_FSID))
 441                                 goto retry;
 442                         break;
 443                 case FSID_UUID8:
 444                 case FSID_UUID16:
 445                         if (!root_export)
 446                                 goto retry;
 447                         /* fall through */
 448                 case FSID_UUID4_INUM:
 449                 case FSID_UUID16_INUM:
 450                         if (exp->ex_uuid == NULL)
 451                                 goto retry;
 452                         break;
 453                 }
 454         } else if (exp->ex_uuid) {
 455                 if (fhp->fh_maxsize >= 64) {
 456                         if (root_export)
 457                                 fsid_type = FSID_UUID16;
 458                         else
 459                                 fsid_type = FSID_UUID16_INUM;
 460                 } else {
 461                         if (root_export)
 462                                 fsid_type = FSID_UUID8;
 463                         else
 464                                 fsid_type = FSID_UUID4_INUM;
 465                 }
 466         } else if (exp->ex_flags & NFSEXP_FSID)
 467                 fsid_type = FSID_NUM;
 468         else if (!old_valid_dev(ex_dev))
 469                 /* for newer device numbers, we must use a newer fsid format */
 470                 fsid_type = FSID_ENCODE_DEV;
 471         else
 472                 fsid_type = FSID_DEV;
 473
 474         if (ref_fh == fhp)
 475                 fh_put(ref_fh);
 476
 477         if (fhp->fh_locked || fhp->fh_dentry) {
 478                 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
 479                        parent->d_name.name, dentry->d_name.name);
 480         }
 481         if (fhp->fh_maxsize < NFS_FHSIZE)
 482                 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
 483                        fhp->fh_maxsize,
 484                        parent->d_name.name, dentry->d_name.name);
 485
 486         fhp->fh_dentry = dget(dentry); /* our internal copy */
 487         fhp->fh_export = exp;
 488         cache_get(&exp->h);
 489
 490         if (version == 0xca) {
 491                 /* old style filehandle please */
 492                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
 493                 fhp->fh_handle.fh_size = NFS_FHSIZE;
 494                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
 495                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
 496                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
 497                 fhp->fh_handle.ofh_xino =
 498                         ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
 499                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
 500                 if (inode)
 501                         _fh_update_old(dentry, exp, &fhp->fh_handle);
 502         } else {
 503                 int len;
 504                 fhp->fh_handle.fh_version = 1;
 505                 fhp->fh_handle.fh_auth_type = 0;
 506                 datap = fhp->fh_handle.fh_auth+0;
 507                 fhp->fh_handle.fh_fsid_type = fsid_type;
 508                 mk_fsid(fsid_type, datap, ex_dev,
 509                         exp->ex_path.dentry->d_inode->i_ino,
 510                         exp->ex_fsid, exp->ex_uuid);
 511
 512                 len = key_len(fsid_type);
 513                 datap += len/4;
 514                 fhp->fh_handle.fh_size = 4 + len;
 515
 516                 if (inode)
 517                         _fh_update(fhp, exp, dentry);
 518                 if (fhp->fh_handle.fh_fileid_type == 255)
 519                         return nfserr_opnotsupp;
 520         }
 521
 522         nfsd_nr_verified++;
 523         return 0;
 524 }
 525
 526 /*
 527  * Update file handle information after changing a dentry.
 528  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
 529  */
 530 __be32
 531 fh_update(struct svc_fh *fhp)
 532 {
 533         struct dentry *dentry;
 534
 535         if (!fhp->fh_dentry)
 536                 goto out_bad;
 537
 538         dentry = fhp->fh_dentry;
 539         if (!dentry->d_inode)
 540                 goto out_negative;
 541         if (fhp->fh_handle.fh_version != 1) {
 542                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
 543         } else {
 544                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
 545                         goto out;
 546
 547                 _fh_update(fhp, fhp->fh_export, dentry);
 548                 if (fhp->fh_handle.fh_fileid_type == 255)
 549                         return nfserr_opnotsupp;
 550         }
 551 out:
 552         return 0;
 553
 554 out_bad:
 555         printk(KERN_ERR "fh_update: fh not verified!\n");
 556         goto out;
 557 out_negative:
 558         printk(KERN_ERR "fh_update: %s/%s still negative!\n",
 559                 dentry->d_parent->d_name.name, dentry->d_name.name);
 560         goto out;
 561 }
 562
 563 /*
 564  * Release a file handle.
 565  */
 566 void
 567 fh_put(struct svc_fh *fhp)
 568 {
 569         struct dentry * dentry = fhp->fh_dentry;
 570         struct svc_export * exp = fhp->fh_export;
 571         if (dentry) {
 572                 fh_unlock(fhp);
 573                 fhp->fh_dentry = NULL;
 574                 dput(dentry);
 575 #ifdef CONFIG_NFSD_V3
 576                 fhp->fh_pre_saved = 0;
 577                 fhp->fh_post_saved = 0;
 578 #endif
 579                 nfsd_nr_put++;
 580         }
 581         if (exp) {
 582                 cache_put(&exp->h, &svc_export_cache);
 583                 fhp->fh_export = NULL;
 584         }
 585         return;
 586 }
 587
 588 /*
 589  * Shorthand for dprintk()'s
 590  */
 591 char * SVCFH_fmt(struct svc_fh *fhp)
 592 {
 593         struct knfsd_fh *fh = &fhp->fh_handle;
 594
 595         static char buf[80];
 596         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
 597                 fh->fh_size,
 598                 fh->fh_base.fh_pad[0],
 599                 fh->fh_base.fh_pad[1],
 600                 fh->fh_base.fh_pad[2],
 601                 fh->fh_base.fh_pad[3],
 602                 fh->fh_base.fh_pad[4],
 603                 fh->fh_base.fh_pad[5]);
 604         return buf;
 605 }
 606
 607 enum fsid_source fsid_source(struct svc_fh *fhp)
 608 {
 609         if (fhp->fh_handle.fh_version != 1)
 610                 return FSIDSOURCE_DEV;
 611         switch(fhp->fh_handle.fh_fsid_type) {
 612         case FSID_DEV:
 613         case FSID_ENCODE_DEV:
 614         case FSID_MAJOR_MINOR:
 615                 if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 616                     & FS_REQUIRES_DEV)
 617                         return FSIDSOURCE_DEV;
 618                 break;
 619         case FSID_NUM:
 620                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 621                         return FSIDSOURCE_FSID;
 622                 break;
 623         default:
 624                 break;
 625         }
 626         /* either a UUID type filehandle, or the filehandle doesn't
 627          * match the export.
 628          */
 629         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 630                 return FSIDSOURCE_FSID;
 631         if (fhp->fh_export->ex_uuid)
 632                 return FSIDSOURCE_UUID;
 633         return FSIDSOURCE_DEV;
 634 }