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 = permission(parent->d_inode, MAY_EXEC, NULL);
  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 <<<<<<< HEAD:fs/nfsd/nfsfh.c
 105                 char buf[RPC_MAX_ADDRBUFLEN];
 106 =======
 107                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 108 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/nfsd/nfsfh.c
 109                 dprintk(KERN_WARNING
 110                        "nfsd: request from insecure port %s!\n",
 111                        svc_print_addr(rqstp, buf, sizeof(buf)));
 112                 return nfserr_perm;
 113         }
 114
 115         /* Set user creds for this exportpoint */
 116         return nfserrno(nfsd_setuser(rqstp, exp));
 117 }
 118
 119 /*
 120  * Perform sanity checks on the dentry in a client's file handle.
 121  *
 122  * Note that the file handle dentry may need to be freed even after
 123  * an error return.
 124  *
 125  * This is only called at the start of an nfsproc call, so fhp points to
 126  * a svc_fh which is all 0 except for the over-the-wire file handle.
 127  */
 128 __be32
 129 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
 130 {
 131         struct knfsd_fh *fh = &fhp->fh_handle;
 132         struct svc_export *exp = NULL;
 133         struct dentry   *dentry;
 134         __be32          error = 0;
 135
 136         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
 137
 138         if (!fhp->fh_dentry) {
 139                 struct fid *fid = NULL, sfid;
 140                 int fileid_type;
 141                 int data_left = fh->fh_size/4;
 142
 143                 error = nfserr_stale;
 144                 if (rqstp->rq_vers > 2)
 145                         error = nfserr_badhandle;
 146                 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
 147                         return nfserr_nofilehandle;
 148
 149                 if (fh->fh_version == 1) {
 150                         int len;
 151                         if (--data_left<0) goto out;
 152                         switch (fh->fh_auth_type) {
 153                         case 0: break;
 154                         default: goto out;
 155                         }
 156                         len = key_len(fh->fh_fsid_type) / 4;
 157                         if (len == 0) goto out;
 158                         if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
 159                                 /* deprecated, convert to type 3 */
 160                                 len = key_len(FSID_ENCODE_DEV)/4;
 161                                 fh->fh_fsid_type = FSID_ENCODE_DEV;
 162                                 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
 163                                 fh->fh_fsid[1] = fh->fh_fsid[2];
 164                         }
 165                         if ((data_left -= len)<0) goto out;
 166                         exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
 167                                             fh->fh_auth);
 168                         fid = (struct fid *)(fh->fh_auth + len);
 169                 } else {
 170                         __u32 tfh[2];
 171                         dev_t xdev;
 172                         ino_t xino;
 173                         if (fh->fh_size != NFS_FHSIZE)
 174                                 goto out;
 175                         /* assume old filehandle format */
 176                         xdev = old_decode_dev(fh->ofh_xdev);
 177                         xino = u32_to_ino_t(fh->ofh_xino);
 178                         mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
 179                         exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
 180                 }
 181
 182                 error = nfserr_stale;
 183                 if (PTR_ERR(exp) == -ENOENT)
 184                         goto out;
 185
 186                 if (IS_ERR(exp)) {
 187                         error = nfserrno(PTR_ERR(exp));
 188                         goto out;
 189                 }
 190
 191                 error = nfsd_setuser_and_check_port(rqstp, exp);
 192                 if (error)
 193                         goto out;
 194
 195                 /*
 196                  * Look up the dentry using the NFS file handle.
 197                  */
 198                 error = nfserr_stale;
 199                 if (rqstp->rq_vers > 2)
 200                         error = nfserr_badhandle;
 201
 202                 if (fh->fh_version != 1) {
 203                         sfid.i32.ino = fh->ofh_ino;
 204                         sfid.i32.gen = fh->ofh_generation;
 205                         sfid.i32.parent_ino = fh->ofh_dirino;
 206                         fid = &sfid;
 207                         data_left = 3;
 208                         if (fh->ofh_dirino == 0)
 209                                 fileid_type = FILEID_INO32_GEN;
 210                         else
 211                                 fileid_type = FILEID_INO32_GEN_PARENT;
 212                 } else
 213                         fileid_type = fh->fh_fileid_type;
 214
 215                 if (fileid_type == FILEID_ROOT)
 216                         dentry = dget(exp->ex_path.dentry);
 217                 else {
 218                         dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
 219                                         data_left, fileid_type,
 220                                         nfsd_acceptable, exp);
 221                 }
 222                 if (dentry == NULL)
 223                         goto out;
 224                 if (IS_ERR(dentry)) {
 225                         if (PTR_ERR(dentry) != -EINVAL)
 226                                 error = nfserrno(PTR_ERR(dentry));
 227                         goto out;
 228                 }
 229
 230                 if (S_ISDIR(dentry->d_inode->i_mode) &&
 231                     (dentry->d_flags & DCACHE_DISCONNECTED)) {
 232                         printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
 233                                dentry->d_parent->d_name.name, dentry->d_name.name);
 234                 }
 235
 236                 fhp->fh_dentry = dentry;
 237                 fhp->fh_export = exp;
 238                 nfsd_nr_verified++;
 239 <<<<<<< HEAD:fs/nfsd/nfsfh.c
 240 =======
 241                 cache_get(&exp->h);
 242 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/nfsd/nfsfh.c
 243         } else {
 244                 /*
 245                  * just rechecking permissions
 246                  * (e.g. nfsproc_create calls fh_verify, then nfsd_create
 247                  * does as well)
 248                  */
 249                 dprintk("nfsd: fh_verify - just checking\n");
 250                 dentry = fhp->fh_dentry;
 251                 exp = fhp->fh_export;
 252 <<<<<<< HEAD:fs/nfsd/nfsfh.c
 253 =======
 254                 cache_get(&exp->h);
 255 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/nfsd/nfsfh.c
 256                 /*
 257                  * Set user creds for this exportpoint; necessary even
 258                  * in the "just checking" case because this may be a
 259                  * filehandle that was created by fh_compose, and that
 260                  * is about to be used in another nfsv4 compound
 261                  * operation.
 262                  */
 263                 error = nfsd_setuser_and_check_port(rqstp, exp);
 264                 if (error)
 265                         goto out;
 266         }
 267 <<<<<<< HEAD:fs/nfsd/nfsfh.c
 268         cache_get(&exp->h);
 269
 270 =======
 271 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/nfsd/nfsfh.c
 272
 273         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
 274         if (error)
 275                 goto out;
 276
 277         if (!(access & MAY_LOCK)) {
 278                 /*
 279                  * pseudoflavor restrictions are not enforced on NLM,
 280                  * which clients virtually always use auth_sys for,
 281                  * even while using RPCSEC_GSS for NFS.
 282                  */
 283                 error = check_nfsd_access(exp, rqstp);
 284                 if (error)
 285                         goto out;
 286         }
 287
 288         /* Finally, check access permissions. */
 289         error = nfsd_permission(rqstp, exp, dentry, access);
 290
 291         if (error) {
 292                 dprintk("fh_verify: %s/%s permission failure, "
 293                         "acc=%x, error=%d\n",
 294                         dentry->d_parent->d_name.name,
 295                         dentry->d_name.name,
 296                         access, ntohl(error));
 297         }
 298 out:
 299         if (exp && !IS_ERR(exp))
 300                 exp_put(exp);
 301         if (error == nfserr_stale)
 302                 nfsdstats.fh_stale++;
 303         return error;
 304 }
 305
 306
 307 /*
 308  * Compose a file handle for an NFS reply.
 309  *
 310  * Note that when first composed, the dentry may not yet have
 311  * an inode.  In this case a call to fh_update should be made
 312  * before the fh goes out on the wire ...
 313  */
 314 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
 315                 struct dentry *dentry)
 316 {
 317         if (dentry != exp->ex_path.dentry) {
 318                 struct fid *fid = (struct fid *)
 319                         (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
 320                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
 321                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
 322
 323                 fhp->fh_handle.fh_fileid_type =
 324                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
 325                 fhp->fh_handle.fh_size += maxsize * 4;
 326         } else {
 327                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
 328         }
 329 }
 330
 331 /*
 332  * for composing old style file handles
 333  */
 334 static inline void _fh_update_old(struct dentry *dentry,
 335                                   struct svc_export *exp,
 336                                   struct knfsd_fh *fh)
 337 {
 338         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
 339         fh->ofh_generation = dentry->d_inode->i_generation;
 340         if (S_ISDIR(dentry->d_inode->i_mode) ||
 341             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
 342                 fh->ofh_dirino = 0;
 343 }
 344
 345 __be32
 346 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
 347            struct svc_fh *ref_fh)
 348 {
 349         /* ref_fh is a reference file handle.
 350          * if it is non-null and for the same filesystem, then we should compose
 351          * a filehandle which is of the same version, where possible.
 352          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
 353          * Then create a 32byte filehandle using nfs_fhbase_old
 354          *
 355          */
 356
 357         u8 version;
 358         u8 fsid_type = 0;
 359         struct inode * inode = dentry->d_inode;
 360         struct dentry *parent = dentry->d_parent;
 361         __u32 *datap;
 362         dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
 363         int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
 364
 365         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
 366                 MAJOR(ex_dev), MINOR(ex_dev),
 367                 (long) exp->ex_path.dentry->d_inode->i_ino,
 368                 parent->d_name.name, dentry->d_name.name,
 369                 (inode ? inode->i_ino : 0));
 370
 371         /* Choose filehandle version and fsid type based on
 372          * the reference filehandle (if it is in the same export)
 373          * or the export options.
 374          */
 375  retry:
 376         version = 1;
 377         if (ref_fh && ref_fh->fh_export == exp) {
 378                 version = ref_fh->fh_handle.fh_version;
 379                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
 380
 381                 if (ref_fh == fhp)
 382                         fh_put(ref_fh);
 383                 ref_fh = NULL;
 384
 385                 switch (version) {
 386                 case 0xca:
 387                         fsid_type = FSID_DEV;
 388                         break;
 389                 case 1:
 390                         break;
 391                 default:
 392                         goto retry;
 393                 }
 394
 395                 /* Need to check that this type works for this
 396                  * export point.  As the fsid -> filesystem mapping
 397                  * was guided by user-space, there is no guarantee
 398                  * that the filesystem actually supports that fsid
 399                  * type. If it doesn't we loop around again without
 400                  * ref_fh set.
 401                  */
 402                 switch(fsid_type) {
 403                 case FSID_DEV:
 404                         if (!old_valid_dev(ex_dev))
 405                                 goto retry;
 406                         /* FALL THROUGH */
 407                 case FSID_MAJOR_MINOR:
 408                 case FSID_ENCODE_DEV:
 409                         if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 410                               & FS_REQUIRES_DEV))
 411                                 goto retry;
 412                         break;
 413                 case FSID_NUM:
 414                         if (! (exp->ex_flags & NFSEXP_FSID))
 415                                 goto retry;
 416                         break;
 417                 case FSID_UUID8:
 418                 case FSID_UUID16:
 419                         if (!root_export)
 420                                 goto retry;
 421                         /* fall through */
 422                 case FSID_UUID4_INUM:
 423                 case FSID_UUID16_INUM:
 424                         if (exp->ex_uuid == NULL)
 425                                 goto retry;
 426                         break;
 427                 }
 428         } else if (exp->ex_uuid) {
 429                 if (fhp->fh_maxsize >= 64) {
 430                         if (root_export)
 431                                 fsid_type = FSID_UUID16;
 432                         else
 433                                 fsid_type = FSID_UUID16_INUM;
 434                 } else {
 435                         if (root_export)
 436                                 fsid_type = FSID_UUID8;
 437                         else
 438                                 fsid_type = FSID_UUID4_INUM;
 439                 }
 440         } else if (exp->ex_flags & NFSEXP_FSID)
 441                 fsid_type = FSID_NUM;
 442         else if (!old_valid_dev(ex_dev))
 443                 /* for newer device numbers, we must use a newer fsid format */
 444                 fsid_type = FSID_ENCODE_DEV;
 445         else
 446                 fsid_type = FSID_DEV;
 447
 448         if (ref_fh == fhp)
 449                 fh_put(ref_fh);
 450
 451         if (fhp->fh_locked || fhp->fh_dentry) {
 452                 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
 453                        parent->d_name.name, dentry->d_name.name);
 454         }
 455         if (fhp->fh_maxsize < NFS_FHSIZE)
 456                 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
 457                        fhp->fh_maxsize,
 458                        parent->d_name.name, dentry->d_name.name);
 459
 460         fhp->fh_dentry = dget(dentry); /* our internal copy */
 461         fhp->fh_export = exp;
 462         cache_get(&exp->h);
 463
 464         if (version == 0xca) {
 465                 /* old style filehandle please */
 466                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
 467                 fhp->fh_handle.fh_size = NFS_FHSIZE;
 468                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
 469                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
 470                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
 471                 fhp->fh_handle.ofh_xino =
 472                         ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
 473                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
 474                 if (inode)
 475                         _fh_update_old(dentry, exp, &fhp->fh_handle);
 476         } else {
 477                 int len;
 478                 fhp->fh_handle.fh_version = 1;
 479                 fhp->fh_handle.fh_auth_type = 0;
 480                 datap = fhp->fh_handle.fh_auth+0;
 481                 fhp->fh_handle.fh_fsid_type = fsid_type;
 482                 mk_fsid(fsid_type, datap, ex_dev,
 483                         exp->ex_path.dentry->d_inode->i_ino,
 484                         exp->ex_fsid, exp->ex_uuid);
 485
 486                 len = key_len(fsid_type);
 487                 datap += len/4;
 488                 fhp->fh_handle.fh_size = 4 + len;
 489
 490                 if (inode)
 491                         _fh_update(fhp, exp, dentry);
 492                 if (fhp->fh_handle.fh_fileid_type == 255)
 493                         return nfserr_opnotsupp;
 494         }
 495
 496         nfsd_nr_verified++;
 497         return 0;
 498 }
 499
 500 /*
 501  * Update file handle information after changing a dentry.
 502  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
 503  */
 504 __be32
 505 fh_update(struct svc_fh *fhp)
 506 {
 507         struct dentry *dentry;
 508
 509         if (!fhp->fh_dentry)
 510                 goto out_bad;
 511
 512         dentry = fhp->fh_dentry;
 513         if (!dentry->d_inode)
 514                 goto out_negative;
 515         if (fhp->fh_handle.fh_version != 1) {
 516                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
 517         } else {
 518                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
 519                         goto out;
 520
 521                 _fh_update(fhp, fhp->fh_export, dentry);
 522                 if (fhp->fh_handle.fh_fileid_type == 255)
 523                         return nfserr_opnotsupp;
 524         }
 525 out:
 526         return 0;
 527
 528 out_bad:
 529         printk(KERN_ERR "fh_update: fh not verified!\n");
 530         goto out;
 531 out_negative:
 532         printk(KERN_ERR "fh_update: %s/%s still negative!\n",
 533                 dentry->d_parent->d_name.name, dentry->d_name.name);
 534         goto out;
 535 }
 536
 537 /*
 538  * Release a file handle.
 539  */
 540 void
 541 fh_put(struct svc_fh *fhp)
 542 {
 543         struct dentry * dentry = fhp->fh_dentry;
 544         struct svc_export * exp = fhp->fh_export;
 545         if (dentry) {
 546                 fh_unlock(fhp);
 547                 fhp->fh_dentry = NULL;
 548                 dput(dentry);
 549 #ifdef CONFIG_NFSD_V3
 550                 fhp->fh_pre_saved = 0;
 551                 fhp->fh_post_saved = 0;
 552 #endif
 553                 nfsd_nr_put++;
 554         }
 555         if (exp) {
 556                 cache_put(&exp->h, &svc_export_cache);
 557                 fhp->fh_export = NULL;
 558         }
 559         return;
 560 }
 561
 562 /*
 563  * Shorthand for dprintk()'s
 564  */
 565 char * SVCFH_fmt(struct svc_fh *fhp)
 566 {
 567         struct knfsd_fh *fh = &fhp->fh_handle;
 568
 569         static char buf[80];
 570         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
 571                 fh->fh_size,
 572                 fh->fh_base.fh_pad[0],
 573                 fh->fh_base.fh_pad[1],
 574                 fh->fh_base.fh_pad[2],
 575                 fh->fh_base.fh_pad[3],
 576                 fh->fh_base.fh_pad[4],
 577                 fh->fh_base.fh_pad[5]);
 578         return buf;
 579 }
 580
 581 enum fsid_source fsid_source(struct svc_fh *fhp)
 582 {
 583         if (fhp->fh_handle.fh_version != 1)
 584                 return FSIDSOURCE_DEV;
 585         switch(fhp->fh_handle.fh_fsid_type) {
 586         case FSID_DEV:
 587         case FSID_ENCODE_DEV:
 588         case FSID_MAJOR_MINOR:
 589                 if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 590                     & FS_REQUIRES_DEV)
 591                         return FSIDSOURCE_DEV;
 592                 break;
 593         case FSID_NUM:
 594                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 595                         return FSIDSOURCE_FSID;
 596                 break;
 597         default:
 598                 break;
 599         }
 600         /* either a UUID type filehandle, or the filehandle doesn't
 601          * match the export.
 602          */
 603         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 604                 return FSIDSOURCE_FSID;
 605         if (fhp->fh_export->ex_uuid)
 606                 return FSIDSOURCE_UUID;
 607         return FSIDSOURCE_DEV;
 608 }