Merge git://git.infradead.org/mtd-2.6
[linux-2.6] / 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 /*
31  * our acceptability function.
32  * if NOSUBTREECHECK, accept anything
33  * if not, require that we can walk up to exp->ex_dentry
34  * doing some checks on the 'x' bits
35  */
36 static int nfsd_acceptable(void *expv, struct dentry *dentry)
37 {
38         struct svc_export *exp = expv;
39         int rv;
40         struct dentry *tdentry;
41         struct dentry *parent;
42
43         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
44                 return 1;
45
46         tdentry = dget(dentry);
47         while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
48                 /* make sure parents give x permission to user */
49                 int err;
50                 parent = dget_parent(tdentry);
51                 err = inode_permission(parent->d_inode, MAY_EXEC);
52                 if (err < 0) {
53                         dput(parent);
54                         break;
55                 }
56                 dput(tdentry);
57                 tdentry = parent;
58         }
59         if (tdentry != exp->ex_path.dentry)
60                 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
61         rv = (tdentry == exp->ex_path.dentry);
62         dput(tdentry);
63         return rv;
64 }
65
66 /* Type check. The correct error return for type mismatches does not seem to be
67  * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
68  * comment in the NFSv3 spec says this is incorrect (implementation notes for
69  * the write call).
70  */
71 static inline __be32
72 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
73 {
74         /* Type can be negative when creating hardlinks - not to a dir */
75         if (type > 0 && (mode & S_IFMT) != type) {
76                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
77                         return nfserr_symlink;
78                 else if (type == S_IFDIR)
79                         return nfserr_notdir;
80                 else if ((mode & S_IFMT) == S_IFDIR)
81                         return nfserr_isdir;
82                 else
83                         return nfserr_inval;
84         }
85         if (type < 0 && (mode & S_IFMT) == -type) {
86                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
87                         return nfserr_symlink;
88                 else if (type == -S_IFDIR)
89                         return nfserr_isdir;
90                 else
91                         return nfserr_notdir;
92         }
93         return 0;
94 }
95
96 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
97                                           struct svc_export *exp)
98 {
99         /* Check if the request originated from a secure port. */
100         if (!rqstp->rq_secure && EX_SECURE(exp)) {
101                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
102                 dprintk(KERN_WARNING
103                        "nfsd: request from insecure port %s!\n",
104                        svc_print_addr(rqstp, buf, sizeof(buf)));
105                 return nfserr_perm;
106         }
107
108         /* Set user creds for this exportpoint */
109         return nfserrno(nfsd_setuser(rqstp, exp));
110 }
111
112 /*
113  * Use the given filehandle to look up the corresponding export and
114  * dentry.  On success, the results are used to set fh_export and
115  * fh_dentry.
116  */
117 static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
118 {
119         struct knfsd_fh *fh = &fhp->fh_handle;
120         struct fid *fid = NULL, sfid;
121         struct svc_export *exp;
122         struct dentry *dentry;
123         int fileid_type;
124         int data_left = fh->fh_size/4;
125         __be32 error;
126
127         error = nfserr_stale;
128         if (rqstp->rq_vers > 2)
129                 error = nfserr_badhandle;
130         if (rqstp->rq_vers == 4 && fh->fh_size == 0)
131                 return nfserr_nofilehandle;
132
133         if (fh->fh_version == 1) {
134                 int len;
135
136                 if (--data_left < 0)
137                         return error;
138                 if (fh->fh_auth_type != 0)
139                         return error;
140                 len = key_len(fh->fh_fsid_type) / 4;
141                 if (len == 0)
142                         return error;
143                 if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
144                         /* deprecated, convert to type 3 */
145                         len = key_len(FSID_ENCODE_DEV)/4;
146                         fh->fh_fsid_type = FSID_ENCODE_DEV;
147                         fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
148                         fh->fh_fsid[1] = fh->fh_fsid[2];
149                 }
150                 data_left -= len;
151                 if (data_left < 0)
152                         return error;
153                 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
154                 fid = (struct fid *)(fh->fh_auth + len);
155         } else {
156                 __u32 tfh[2];
157                 dev_t xdev;
158                 ino_t xino;
159
160                 if (fh->fh_size != NFS_FHSIZE)
161                         return error;
162                 /* assume old filehandle format */
163                 xdev = old_decode_dev(fh->ofh_xdev);
164                 xino = u32_to_ino_t(fh->ofh_xino);
165                 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
166                 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
167         }
168
169         error = nfserr_stale;
170         if (PTR_ERR(exp) == -ENOENT)
171                 return error;
172
173         if (IS_ERR(exp))
174                 return nfserrno(PTR_ERR(exp));
175
176         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
177                 /* Elevate privileges so that the lack of 'r' or 'x'
178                  * permission on some parent directory will
179                  * not stop exportfs_decode_fh from being able
180                  * to reconnect a directory into the dentry cache.
181                  * The same problem can affect "SUBTREECHECK" exports,
182                  * but as nfsd_acceptable depends on correct
183                  * access control settings being in effect, we cannot
184                  * fix that case easily.
185                  */
186                 struct cred *new = prepare_creds();
187                 if (!new)
188                         return nfserrno(-ENOMEM);
189                 new->cap_effective =
190                         cap_raise_nfsd_set(new->cap_effective,
191                                            new->cap_permitted);
192                 put_cred(override_creds(new));
193                 put_cred(new);
194         } else {
195                 error = nfsd_setuser_and_check_port(rqstp, exp);
196                 if (error)
197                         goto out;
198         }
199
200         /*
201          * Look up the dentry using the NFS file handle.
202          */
203         error = nfserr_stale;
204         if (rqstp->rq_vers > 2)
205                 error = nfserr_badhandle;
206
207         if (fh->fh_version != 1) {
208                 sfid.i32.ino = fh->ofh_ino;
209                 sfid.i32.gen = fh->ofh_generation;
210                 sfid.i32.parent_ino = fh->ofh_dirino;
211                 fid = &sfid;
212                 data_left = 3;
213                 if (fh->ofh_dirino == 0)
214                         fileid_type = FILEID_INO32_GEN;
215                 else
216                         fileid_type = FILEID_INO32_GEN_PARENT;
217         } else
218                 fileid_type = fh->fh_fileid_type;
219
220         if (fileid_type == FILEID_ROOT)
221                 dentry = dget(exp->ex_path.dentry);
222         else {
223                 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
224                                 data_left, fileid_type,
225                                 nfsd_acceptable, exp);
226         }
227         if (dentry == NULL)
228                 goto out;
229         if (IS_ERR(dentry)) {
230                 if (PTR_ERR(dentry) != -EINVAL)
231                         error = nfserrno(PTR_ERR(dentry));
232                 goto out;
233         }
234
235         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
236                 error = nfsd_setuser_and_check_port(rqstp, exp);
237                 if (error) {
238                         dput(dentry);
239                         goto out;
240                 }
241         }
242
243         if (S_ISDIR(dentry->d_inode->i_mode) &&
244                         (dentry->d_flags & DCACHE_DISCONNECTED)) {
245                 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
246                                 dentry->d_parent->d_name.name, dentry->d_name.name);
247         }
248
249         fhp->fh_dentry = dentry;
250         fhp->fh_export = exp;
251         return 0;
252 out:
253         exp_put(exp);
254         return error;
255 }
256
257 /**
258  * fh_verify - filehandle lookup and access checking
259  * @rqstp: pointer to current rpc request
260  * @fhp: filehandle to be verified
261  * @type: expected type of object pointed to by filehandle
262  * @access: type of access needed to object
263  *
264  * Look up a dentry from the on-the-wire filehandle, check the client's
265  * access to the export, and set the current task's credentials.
266  *
267  * Regardless of success or failure of fh_verify(), fh_put() should be
268  * called on @fhp when the caller is finished with the filehandle.
269  *
270  * fh_verify() may be called multiple times on a given filehandle, for
271  * example, when processing an NFSv4 compound.  The first call will look
272  * up a dentry using the on-the-wire filehandle.  Subsequent calls will
273  * skip the lookup and just perform the other checks and possibly change
274  * the current task's credentials.
275  *
276  * @type specifies the type of object expected using one of the S_IF*
277  * constants defined in include/linux/stat.h.  The caller may use zero
278  * to indicate that it doesn't care, or a negative integer to indicate
279  * that it expects something not of the given type.
280  *
281  * @access is formed from the NFSD_MAY_* constants defined in
282  * include/linux/nfsd/nfsd.h.
283  */
284 __be32
285 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
286 {
287         struct svc_export *exp;
288         struct dentry   *dentry;
289         __be32          error;
290
291         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
292
293         if (!fhp->fh_dentry) {
294                 error = nfsd_set_fh_dentry(rqstp, fhp);
295                 if (error)
296                         goto out;
297                 dentry = fhp->fh_dentry;
298                 exp = fhp->fh_export;
299         } else {
300                 /*
301                  * just rechecking permissions
302                  * (e.g. nfsproc_create calls fh_verify, then nfsd_create
303                  * does as well)
304                  */
305                 dprintk("nfsd: fh_verify - just checking\n");
306                 dentry = fhp->fh_dentry;
307                 exp = fhp->fh_export;
308                 /*
309                  * Set user creds for this exportpoint; necessary even
310                  * in the "just checking" case because this may be a
311                  * filehandle that was created by fh_compose, and that
312                  * is about to be used in another nfsv4 compound
313                  * operation.
314                  */
315                 error = nfsd_setuser_and_check_port(rqstp, exp);
316                 if (error)
317                         goto out;
318         }
319
320         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
321         if (error)
322                 goto out;
323
324         /*
325          * pseudoflavor restrictions are not enforced on NLM,
326          * which clients virtually always use auth_sys for,
327          * even while using RPCSEC_GSS for NFS.
328          */
329         if (access & NFSD_MAY_LOCK)
330                 goto skip_pseudoflavor_check;
331         /*
332          * Clients may expect to be able to use auth_sys during mount,
333          * even if they use gss for everything else; see section 2.3.2
334          * of rfc 2623.
335          */
336         if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
337                         && exp->ex_path.dentry == dentry)
338                 goto skip_pseudoflavor_check;
339
340         error = check_nfsd_access(exp, rqstp);
341         if (error)
342                 goto out;
343
344 skip_pseudoflavor_check:
345         /* Finally, check access permissions. */
346         error = nfsd_permission(rqstp, exp, dentry, access);
347
348         if (error) {
349                 dprintk("fh_verify: %s/%s permission failure, "
350                         "acc=%x, error=%d\n",
351                         dentry->d_parent->d_name.name,
352                         dentry->d_name.name,
353                         access, ntohl(error));
354         }
355 out:
356         if (error == nfserr_stale)
357                 nfsdstats.fh_stale++;
358         return error;
359 }
360
361
362 /*
363  * Compose a file handle for an NFS reply.
364  *
365  * Note that when first composed, the dentry may not yet have
366  * an inode.  In this case a call to fh_update should be made
367  * before the fh goes out on the wire ...
368  */
369 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
370                 struct dentry *dentry)
371 {
372         if (dentry != exp->ex_path.dentry) {
373                 struct fid *fid = (struct fid *)
374                         (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
375                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
376                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
377
378                 fhp->fh_handle.fh_fileid_type =
379                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
380                 fhp->fh_handle.fh_size += maxsize * 4;
381         } else {
382                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
383         }
384 }
385
386 /*
387  * for composing old style file handles
388  */
389 static inline void _fh_update_old(struct dentry *dentry,
390                                   struct svc_export *exp,
391                                   struct knfsd_fh *fh)
392 {
393         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
394         fh->ofh_generation = dentry->d_inode->i_generation;
395         if (S_ISDIR(dentry->d_inode->i_mode) ||
396             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
397                 fh->ofh_dirino = 0;
398 }
399
400 __be32
401 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
402            struct svc_fh *ref_fh)
403 {
404         /* ref_fh is a reference file handle.
405          * if it is non-null and for the same filesystem, then we should compose
406          * a filehandle which is of the same version, where possible.
407          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
408          * Then create a 32byte filehandle using nfs_fhbase_old
409          *
410          */
411
412         u8 version;
413         u8 fsid_type = 0;
414         struct inode * inode = dentry->d_inode;
415         struct dentry *parent = dentry->d_parent;
416         __u32 *datap;
417         dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
418         int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
419
420         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
421                 MAJOR(ex_dev), MINOR(ex_dev),
422                 (long) exp->ex_path.dentry->d_inode->i_ino,
423                 parent->d_name.name, dentry->d_name.name,
424                 (inode ? inode->i_ino : 0));
425
426         /* Choose filehandle version and fsid type based on
427          * the reference filehandle (if it is in the same export)
428          * or the export options.
429          */
430  retry:
431         version = 1;
432         if (ref_fh && ref_fh->fh_export == exp) {
433                 version = ref_fh->fh_handle.fh_version;
434                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
435
436                 if (ref_fh == fhp)
437                         fh_put(ref_fh);
438                 ref_fh = NULL;
439
440                 switch (version) {
441                 case 0xca:
442                         fsid_type = FSID_DEV;
443                         break;
444                 case 1:
445                         break;
446                 default:
447                         goto retry;
448                 }
449
450                 /* Need to check that this type works for this
451                  * export point.  As the fsid -> filesystem mapping
452                  * was guided by user-space, there is no guarantee
453                  * that the filesystem actually supports that fsid
454                  * type. If it doesn't we loop around again without
455                  * ref_fh set.
456                  */
457                 switch(fsid_type) {
458                 case FSID_DEV:
459                         if (!old_valid_dev(ex_dev))
460                                 goto retry;
461                         /* FALL THROUGH */
462                 case FSID_MAJOR_MINOR:
463                 case FSID_ENCODE_DEV:
464                         if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
465                               & FS_REQUIRES_DEV))
466                                 goto retry;
467                         break;
468                 case FSID_NUM:
469                         if (! (exp->ex_flags & NFSEXP_FSID))
470                                 goto retry;
471                         break;
472                 case FSID_UUID8:
473                 case FSID_UUID16:
474                         if (!root_export)
475                                 goto retry;
476                         /* fall through */
477                 case FSID_UUID4_INUM:
478                 case FSID_UUID16_INUM:
479                         if (exp->ex_uuid == NULL)
480                                 goto retry;
481                         break;
482                 }
483         } else if (exp->ex_flags & NFSEXP_FSID) {
484                 fsid_type = FSID_NUM;
485         } else if (exp->ex_uuid) {
486                 if (fhp->fh_maxsize >= 64) {
487                         if (root_export)
488                                 fsid_type = FSID_UUID16;
489                         else
490                                 fsid_type = FSID_UUID16_INUM;
491                 } else {
492                         if (root_export)
493                                 fsid_type = FSID_UUID8;
494                         else
495                                 fsid_type = FSID_UUID4_INUM;
496                 }
497         } else if (!old_valid_dev(ex_dev))
498                 /* for newer device numbers, we must use a newer fsid format */
499                 fsid_type = FSID_ENCODE_DEV;
500         else
501                 fsid_type = FSID_DEV;
502
503         if (ref_fh == fhp)
504                 fh_put(ref_fh);
505
506         if (fhp->fh_locked || fhp->fh_dentry) {
507                 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
508                        parent->d_name.name, dentry->d_name.name);
509         }
510         if (fhp->fh_maxsize < NFS_FHSIZE)
511                 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
512                        fhp->fh_maxsize,
513                        parent->d_name.name, dentry->d_name.name);
514
515         fhp->fh_dentry = dget(dentry); /* our internal copy */
516         fhp->fh_export = exp;
517         cache_get(&exp->h);
518
519         if (version == 0xca) {
520                 /* old style filehandle please */
521                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
522                 fhp->fh_handle.fh_size = NFS_FHSIZE;
523                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
524                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
525                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
526                 fhp->fh_handle.ofh_xino =
527                         ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
528                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
529                 if (inode)
530                         _fh_update_old(dentry, exp, &fhp->fh_handle);
531         } else {
532                 int len;
533                 fhp->fh_handle.fh_version = 1;
534                 fhp->fh_handle.fh_auth_type = 0;
535                 datap = fhp->fh_handle.fh_auth+0;
536                 fhp->fh_handle.fh_fsid_type = fsid_type;
537                 mk_fsid(fsid_type, datap, ex_dev,
538                         exp->ex_path.dentry->d_inode->i_ino,
539                         exp->ex_fsid, exp->ex_uuid);
540
541                 len = key_len(fsid_type);
542                 datap += len/4;
543                 fhp->fh_handle.fh_size = 4 + len;
544
545                 if (inode)
546                         _fh_update(fhp, exp, dentry);
547                 if (fhp->fh_handle.fh_fileid_type == 255)
548                         return nfserr_opnotsupp;
549         }
550
551         return 0;
552 }
553
554 /*
555  * Update file handle information after changing a dentry.
556  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
557  */
558 __be32
559 fh_update(struct svc_fh *fhp)
560 {
561         struct dentry *dentry;
562
563         if (!fhp->fh_dentry)
564                 goto out_bad;
565
566         dentry = fhp->fh_dentry;
567         if (!dentry->d_inode)
568                 goto out_negative;
569         if (fhp->fh_handle.fh_version != 1) {
570                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
571         } else {
572                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
573                         goto out;
574
575                 _fh_update(fhp, fhp->fh_export, dentry);
576                 if (fhp->fh_handle.fh_fileid_type == 255)
577                         return nfserr_opnotsupp;
578         }
579 out:
580         return 0;
581
582 out_bad:
583         printk(KERN_ERR "fh_update: fh not verified!\n");
584         goto out;
585 out_negative:
586         printk(KERN_ERR "fh_update: %s/%s still negative!\n",
587                 dentry->d_parent->d_name.name, dentry->d_name.name);
588         goto out;
589 }
590
591 /*
592  * Release a file handle.
593  */
594 void
595 fh_put(struct svc_fh *fhp)
596 {
597         struct dentry * dentry = fhp->fh_dentry;
598         struct svc_export * exp = fhp->fh_export;
599         if (dentry) {
600                 fh_unlock(fhp);
601                 fhp->fh_dentry = NULL;
602                 dput(dentry);
603 #ifdef CONFIG_NFSD_V3
604                 fhp->fh_pre_saved = 0;
605                 fhp->fh_post_saved = 0;
606 #endif
607         }
608         if (exp) {
609                 cache_put(&exp->h, &svc_export_cache);
610                 fhp->fh_export = NULL;
611         }
612         return;
613 }
614
615 /*
616  * Shorthand for dprintk()'s
617  */
618 char * SVCFH_fmt(struct svc_fh *fhp)
619 {
620         struct knfsd_fh *fh = &fhp->fh_handle;
621
622         static char buf[80];
623         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
624                 fh->fh_size,
625                 fh->fh_base.fh_pad[0],
626                 fh->fh_base.fh_pad[1],
627                 fh->fh_base.fh_pad[2],
628                 fh->fh_base.fh_pad[3],
629                 fh->fh_base.fh_pad[4],
630                 fh->fh_base.fh_pad[5]);
631         return buf;
632 }
633
634 enum fsid_source fsid_source(struct svc_fh *fhp)
635 {
636         if (fhp->fh_handle.fh_version != 1)
637                 return FSIDSOURCE_DEV;
638         switch(fhp->fh_handle.fh_fsid_type) {
639         case FSID_DEV:
640         case FSID_ENCODE_DEV:
641         case FSID_MAJOR_MINOR:
642                 if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
643                     & FS_REQUIRES_DEV)
644                         return FSIDSOURCE_DEV;
645                 break;
646         case FSID_NUM:
647                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
648                         return FSIDSOURCE_FSID;
649                 break;
650         default:
651                 break;
652         }
653         /* either a UUID type filehandle, or the filehandle doesn't
654          * match the export.
655          */
656         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
657                 return FSIDSOURCE_FSID;
658         if (fhp->fh_export->ex_uuid)
659                 return FSIDSOURCE_UUID;
660         return FSIDSOURCE_DEV;
661 }