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1/*
2 * NFS server file handle treatment.
3 *
4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
5 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
6 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
7 * ... and again Southern-Winter 2001 to support export_operations
8 */
9
10#include <linux/exportfs.h>
11
12#include <linux/sunrpc/svcauth_gss.h>
13#include "nfsd.h"
14#include "vfs.h"
15#include "auth.h"
16
17#define NFSDDBG_FACILITY NFSDDBG_FH
18
19
20/*
21 * our acceptability function.
22 * if NOSUBTREECHECK, accept anything
23 * if not, require that we can walk up to exp->ex_dentry
24 * doing some checks on the 'x' bits
25 */
26static int nfsd_acceptable(void *expv, struct dentry *dentry)
27{
28 struct svc_export *exp = expv;
29 int rv;
30 struct dentry *tdentry;
31 struct dentry *parent;
32
33 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
34 return 1;
35
36 tdentry = dget(dentry);
37 while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
38 /* make sure parents give x permission to user */
39 int err;
40 parent = dget_parent(tdentry);
41 err = inode_permission(parent->d_inode, MAY_EXEC);
42 if (err < 0) {
43 dput(parent);
44 break;
45 }
46 dput(tdentry);
47 tdentry = parent;
48 }
49 if (tdentry != exp->ex_path.dentry)
50 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
51 rv = (tdentry == exp->ex_path.dentry);
52 dput(tdentry);
53 return rv;
54}
55
56/* Type check. The correct error return for type mismatches does not seem to be
57 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
58 * comment in the NFSv3 spec says this is incorrect (implementation notes for
59 * the write call).
60 */
61static inline __be32
62nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, umode_t requested)
63{
64 mode &= S_IFMT;
65
66 if (requested == 0) /* the caller doesn't care */
67 return nfs_ok;
68 if (mode == requested)
69 return nfs_ok;
70 /*
71 * v4 has an error more specific than err_notdir which we should
72 * return in preference to err_notdir:
73 */
74 if (rqstp->rq_vers == 4 && mode == S_IFLNK)
75 return nfserr_symlink;
76 if (requested == S_IFDIR)
77 return nfserr_notdir;
78 if (mode == S_IFDIR)
79 return nfserr_isdir;
80 return nfserr_inval;
81}
82
83static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
84 struct svc_export *exp)
85{
86 int flags = nfsexp_flags(rqstp, exp);
87
88 /* Check if the request originated from a secure port. */
89 if (!rqstp->rq_secure && !(flags & NFSEXP_INSECURE_PORT)) {
90 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
91 dprintk(KERN_WARNING
92 "nfsd: request from insecure port %s!\n",
93 svc_print_addr(rqstp, buf, sizeof(buf)));
94 return nfserr_perm;
95 }
96
97 /* Set user creds for this exportpoint */
98 return nfserrno(nfsd_setuser(rqstp, exp));
99}
100
101static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
102 struct dentry *dentry, struct svc_export *exp)
103{
104 if (!(exp->ex_flags & NFSEXP_V4ROOT))
105 return nfs_ok;
106 /*
107 * v2/v3 clients have no need for the V4ROOT export--they use
108 * the mount protocl instead; also, further V4ROOT checks may be
109 * in v4-specific code, in which case v2/v3 clients could bypass
110 * them.
111 */
112 if (!nfsd_v4client(rqstp))
113 return nfserr_stale;
114 /*
115 * We're exposing only the directories and symlinks that have to be
116 * traversed on the way to real exports:
117 */
118 if (unlikely(!S_ISDIR(dentry->d_inode->i_mode) &&
119 !S_ISLNK(dentry->d_inode->i_mode)))
120 return nfserr_stale;
121 /*
122 * A pseudoroot export gives permission to access only one
123 * single directory; the kernel has to make another upcall
124 * before granting access to anything else under it:
125 */
126 if (unlikely(dentry != exp->ex_path.dentry))
127 return nfserr_stale;
128 return nfs_ok;
129}
130
131/*
132 * Use the given filehandle to look up the corresponding export and
133 * dentry. On success, the results are used to set fh_export and
134 * fh_dentry.
135 */
136static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
137{
138 struct knfsd_fh *fh = &fhp->fh_handle;
139 struct fid *fid = NULL, sfid;
140 struct svc_export *exp;
141 struct dentry *dentry;
142 int fileid_type;
143 int data_left = fh->fh_size/4;
144 __be32 error;
145
146 error = nfserr_stale;
147 if (rqstp->rq_vers > 2)
148 error = nfserr_badhandle;
149 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
150 return nfserr_nofilehandle;
151
152 if (fh->fh_version == 1) {
153 int len;
154
155 if (--data_left < 0)
156 return error;
157 if (fh->fh_auth_type != 0)
158 return error;
159 len = key_len(fh->fh_fsid_type) / 4;
160 if (len == 0)
161 return error;
162 if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
163 /* deprecated, convert to type 3 */
164 len = key_len(FSID_ENCODE_DEV)/4;
165 fh->fh_fsid_type = FSID_ENCODE_DEV;
166 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
167 fh->fh_fsid[1] = fh->fh_fsid[2];
168 }
169 data_left -= len;
170 if (data_left < 0)
171 return error;
172 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
173 fid = (struct fid *)(fh->fh_auth + len);
174 } else {
175 __u32 tfh[2];
176 dev_t xdev;
177 ino_t xino;
178
179 if (fh->fh_size != NFS_FHSIZE)
180 return error;
181 /* assume old filehandle format */
182 xdev = old_decode_dev(fh->ofh_xdev);
183 xino = u32_to_ino_t(fh->ofh_xino);
184 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
185 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
186 }
187
188 error = nfserr_stale;
189 if (PTR_ERR(exp) == -ENOENT)
190 return error;
191
192 if (IS_ERR(exp))
193 return nfserrno(PTR_ERR(exp));
194
195 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
196 /* Elevate privileges so that the lack of 'r' or 'x'
197 * permission on some parent directory will
198 * not stop exportfs_decode_fh from being able
199 * to reconnect a directory into the dentry cache.
200 * The same problem can affect "SUBTREECHECK" exports,
201 * but as nfsd_acceptable depends on correct
202 * access control settings being in effect, we cannot
203 * fix that case easily.
204 */
205 struct cred *new = prepare_creds();
206 if (!new)
207 return nfserrno(-ENOMEM);
208 new->cap_effective =
209 cap_raise_nfsd_set(new->cap_effective,
210 new->cap_permitted);
211 put_cred(override_creds(new));
212 put_cred(new);
213 } else {
214 error = nfsd_setuser_and_check_port(rqstp, exp);
215 if (error)
216 goto out;
217 }
218
219 /*
220 * Look up the dentry using the NFS file handle.
221 */
222 error = nfserr_stale;
223 if (rqstp->rq_vers > 2)
224 error = nfserr_badhandle;
225
226 if (fh->fh_version != 1) {
227 sfid.i32.ino = fh->ofh_ino;
228 sfid.i32.gen = fh->ofh_generation;
229 sfid.i32.parent_ino = fh->ofh_dirino;
230 fid = &sfid;
231 data_left = 3;
232 if (fh->ofh_dirino == 0)
233 fileid_type = FILEID_INO32_GEN;
234 else
235 fileid_type = FILEID_INO32_GEN_PARENT;
236 } else
237 fileid_type = fh->fh_fileid_type;
238
239 if (fileid_type == FILEID_ROOT)
240 dentry = dget(exp->ex_path.dentry);
241 else {
242 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
243 data_left, fileid_type,
244 nfsd_acceptable, exp);
245 }
246 if (dentry == NULL)
247 goto out;
248 if (IS_ERR(dentry)) {
249 if (PTR_ERR(dentry) != -EINVAL)
250 error = nfserrno(PTR_ERR(dentry));
251 goto out;
252 }
253
254 if (S_ISDIR(dentry->d_inode->i_mode) &&
255 (dentry->d_flags & DCACHE_DISCONNECTED)) {
256 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
257 dentry->d_parent->d_name.name, dentry->d_name.name);
258 }
259
260 fhp->fh_dentry = dentry;
261 fhp->fh_export = exp;
262 return 0;
263out:
264 exp_put(exp);
265 return error;
266}
267
268/**
269 * fh_verify - filehandle lookup and access checking
270 * @rqstp: pointer to current rpc request
271 * @fhp: filehandle to be verified
272 * @type: expected type of object pointed to by filehandle
273 * @access: type of access needed to object
274 *
275 * Look up a dentry from the on-the-wire filehandle, check the client's
276 * access to the export, and set the current task's credentials.
277 *
278 * Regardless of success or failure of fh_verify(), fh_put() should be
279 * called on @fhp when the caller is finished with the filehandle.
280 *
281 * fh_verify() may be called multiple times on a given filehandle, for
282 * example, when processing an NFSv4 compound. The first call will look
283 * up a dentry using the on-the-wire filehandle. Subsequent calls will
284 * skip the lookup and just perform the other checks and possibly change
285 * the current task's credentials.
286 *
287 * @type specifies the type of object expected using one of the S_IF*
288 * constants defined in include/linux/stat.h. The caller may use zero
289 * to indicate that it doesn't care, or a negative integer to indicate
290 * that it expects something not of the given type.
291 *
292 * @access is formed from the NFSD_MAY_* constants defined in
293 * include/linux/nfsd/nfsd.h.
294 */
295__be32
296fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
297{
298 struct svc_export *exp;
299 struct dentry *dentry;
300 __be32 error;
301
302 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
303
304 if (!fhp->fh_dentry) {
305 error = nfsd_set_fh_dentry(rqstp, fhp);
306 if (error)
307 goto out;
308 }
309 dentry = fhp->fh_dentry;
310 exp = fhp->fh_export;
311 /*
312 * We still have to do all these permission checks, even when
313 * fh_dentry is already set:
314 * - fh_verify may be called multiple times with different
315 * "access" arguments (e.g. nfsd_proc_create calls
316 * fh_verify(...,NFSD_MAY_EXEC) first, then later (in
317 * nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
318 * - in the NFSv4 case, the filehandle may have been filled
319 * in by fh_compose, and given a dentry, but further
320 * compound operations performed with that filehandle
321 * still need permissions checks. In the worst case, a
322 * mountpoint crossing may have changed the export
323 * options, and we may now need to use a different uid
324 * (for example, if different id-squashing options are in
325 * effect on the new filesystem).
326 */
327 error = check_pseudo_root(rqstp, dentry, exp);
328 if (error)
329 goto out;
330
331 error = nfsd_setuser_and_check_port(rqstp, exp);
332 if (error)
333 goto out;
334
335 error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
336 if (error)
337 goto out;
338
339 /*
340 * pseudoflavor restrictions are not enforced on NLM,
341 * which clients virtually always use auth_sys for,
342 * even while using RPCSEC_GSS for NFS.
343 */
344 if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
345 goto skip_pseudoflavor_check;
346 /*
347 * Clients may expect to be able to use auth_sys during mount,
348 * even if they use gss for everything else; see section 2.3.2
349 * of rfc 2623.
350 */
351 if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
352 && exp->ex_path.dentry == dentry)
353 goto skip_pseudoflavor_check;
354
355 error = check_nfsd_access(exp, rqstp);
356 if (error)
357 goto out;
358
359skip_pseudoflavor_check:
360 /* Finally, check access permissions. */
361 error = nfsd_permission(rqstp, exp, dentry, access);
362
363 if (error) {
364 dprintk("fh_verify: %s/%s permission failure, "
365 "acc=%x, error=%d\n",
366 dentry->d_parent->d_name.name,
367 dentry->d_name.name,
368 access, ntohl(error));
369 }
370out:
371 if (error == nfserr_stale)
372 nfsdstats.fh_stale++;
373 return error;
374}
375
376
377/*
378 * Compose a file handle for an NFS reply.
379 *
380 * Note that when first composed, the dentry may not yet have
381 * an inode. In this case a call to fh_update should be made
382 * before the fh goes out on the wire ...
383 */
384static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
385 struct dentry *dentry)
386{
387 if (dentry != exp->ex_path.dentry) {
388 struct fid *fid = (struct fid *)
389 (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
390 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
391 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
392
393 fhp->fh_handle.fh_fileid_type =
394 exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
395 fhp->fh_handle.fh_size += maxsize * 4;
396 } else {
397 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
398 }
399}
400
401/*
402 * for composing old style file handles
403 */
404static inline void _fh_update_old(struct dentry *dentry,
405 struct svc_export *exp,
406 struct knfsd_fh *fh)
407{
408 fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
409 fh->ofh_generation = dentry->d_inode->i_generation;
410 if (S_ISDIR(dentry->d_inode->i_mode) ||
411 (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
412 fh->ofh_dirino = 0;
413}
414
415static bool is_root_export(struct svc_export *exp)
416{
417 return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
418}
419
420static struct super_block *exp_sb(struct svc_export *exp)
421{
422 return exp->ex_path.dentry->d_inode->i_sb;
423}
424
425static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
426{
427 switch (fsid_type) {
428 case FSID_DEV:
429 if (!old_valid_dev(exp_sb(exp)->s_dev))
430 return 0;
431 /* FALL THROUGH */
432 case FSID_MAJOR_MINOR:
433 case FSID_ENCODE_DEV:
434 return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
435 case FSID_NUM:
436 return exp->ex_flags & NFSEXP_FSID;
437 case FSID_UUID8:
438 case FSID_UUID16:
439 if (!is_root_export(exp))
440 return 0;
441 /* fall through */
442 case FSID_UUID4_INUM:
443 case FSID_UUID16_INUM:
444 return exp->ex_uuid != NULL;
445 }
446 return 1;
447}
448
449
450static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
451{
452 u8 version;
453 u8 fsid_type;
454retry:
455 version = 1;
456 if (ref_fh && ref_fh->fh_export == exp) {
457 version = ref_fh->fh_handle.fh_version;
458 fsid_type = ref_fh->fh_handle.fh_fsid_type;
459
460 ref_fh = NULL;
461
462 switch (version) {
463 case 0xca:
464 fsid_type = FSID_DEV;
465 break;
466 case 1:
467 break;
468 default:
469 goto retry;
470 }
471
472 /*
473 * As the fsid -> filesystem mapping was guided by
474 * user-space, there is no guarantee that the filesystem
475 * actually supports that fsid type. If it doesn't we
476 * loop around again without ref_fh set.
477 */
478 if (!fsid_type_ok_for_exp(fsid_type, exp))
479 goto retry;
480 } else if (exp->ex_flags & NFSEXP_FSID) {
481 fsid_type = FSID_NUM;
482 } else if (exp->ex_uuid) {
483 if (fhp->fh_maxsize >= 64) {
484 if (is_root_export(exp))
485 fsid_type = FSID_UUID16;
486 else
487 fsid_type = FSID_UUID16_INUM;
488 } else {
489 if (is_root_export(exp))
490 fsid_type = FSID_UUID8;
491 else
492 fsid_type = FSID_UUID4_INUM;
493 }
494 } else if (!old_valid_dev(exp_sb(exp)->s_dev))
495 /* for newer device numbers, we must use a newer fsid format */
496 fsid_type = FSID_ENCODE_DEV;
497 else
498 fsid_type = FSID_DEV;
499 fhp->fh_handle.fh_version = version;
500 if (version)
501 fhp->fh_handle.fh_fsid_type = fsid_type;
502}
503
504__be32
505fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
506 struct svc_fh *ref_fh)
507{
508 /* ref_fh is a reference file handle.
509 * if it is non-null and for the same filesystem, then we should compose
510 * a filehandle which is of the same version, where possible.
511 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
512 * Then create a 32byte filehandle using nfs_fhbase_old
513 *
514 */
515
516 struct inode * inode = dentry->d_inode;
517 struct dentry *parent = dentry->d_parent;
518 __u32 *datap;
519 dev_t ex_dev = exp_sb(exp)->s_dev;
520
521 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
522 MAJOR(ex_dev), MINOR(ex_dev),
523 (long) exp->ex_path.dentry->d_inode->i_ino,
524 parent->d_name.name, dentry->d_name.name,
525 (inode ? inode->i_ino : 0));
526
527 /* Choose filehandle version and fsid type based on
528 * the reference filehandle (if it is in the same export)
529 * or the export options.
530 */
531 set_version_and_fsid_type(fhp, exp, ref_fh);
532
533 if (ref_fh == fhp)
534 fh_put(ref_fh);
535
536 if (fhp->fh_locked || fhp->fh_dentry) {
537 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
538 parent->d_name.name, dentry->d_name.name);
539 }
540 if (fhp->fh_maxsize < NFS_FHSIZE)
541 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
542 fhp->fh_maxsize,
543 parent->d_name.name, dentry->d_name.name);
544
545 fhp->fh_dentry = dget(dentry); /* our internal copy */
546 fhp->fh_export = exp;
547 cache_get(&exp->h);
548
549 if (fhp->fh_handle.fh_version == 0xca) {
550 /* old style filehandle please */
551 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
552 fhp->fh_handle.fh_size = NFS_FHSIZE;
553 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
554 fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
555 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
556 fhp->fh_handle.ofh_xino =
557 ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
558 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
559 if (inode)
560 _fh_update_old(dentry, exp, &fhp->fh_handle);
561 } else {
562 int len;
563 fhp->fh_handle.fh_auth_type = 0;
564 datap = fhp->fh_handle.fh_auth+0;
565 mk_fsid(fhp->fh_handle.fh_fsid_type, datap, ex_dev,
566 exp->ex_path.dentry->d_inode->i_ino,
567 exp->ex_fsid, exp->ex_uuid);
568
569 len = key_len(fhp->fh_handle.fh_fsid_type);
570 datap += len/4;
571 fhp->fh_handle.fh_size = 4 + len;
572
573 if (inode)
574 _fh_update(fhp, exp, dentry);
575 if (fhp->fh_handle.fh_fileid_type == 255) {
576 fh_put(fhp);
577 return nfserr_opnotsupp;
578 }
579 }
580
581 return 0;
582}
583
584/*
585 * Update file handle information after changing a dentry.
586 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
587 */
588__be32
589fh_update(struct svc_fh *fhp)
590{
591 struct dentry *dentry;
592
593 if (!fhp->fh_dentry)
594 goto out_bad;
595
596 dentry = fhp->fh_dentry;
597 if (!dentry->d_inode)
598 goto out_negative;
599 if (fhp->fh_handle.fh_version != 1) {
600 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
601 } else {
602 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
603 goto out;
604
605 _fh_update(fhp, fhp->fh_export, dentry);
606 if (fhp->fh_handle.fh_fileid_type == 255)
607 return nfserr_opnotsupp;
608 }
609out:
610 return 0;
611
612out_bad:
613 printk(KERN_ERR "fh_update: fh not verified!\n");
614 goto out;
615out_negative:
616 printk(KERN_ERR "fh_update: %s/%s still negative!\n",
617 dentry->d_parent->d_name.name, dentry->d_name.name);
618 goto out;
619}
620
621/*
622 * Release a file handle.
623 */
624void
625fh_put(struct svc_fh *fhp)
626{
627 struct dentry * dentry = fhp->fh_dentry;
628 struct svc_export * exp = fhp->fh_export;
629 if (dentry) {
630 fh_unlock(fhp);
631 fhp->fh_dentry = NULL;
632 dput(dentry);
633#ifdef CONFIG_NFSD_V3
634 fhp->fh_pre_saved = 0;
635 fhp->fh_post_saved = 0;
636#endif
637 }
638 if (exp) {
639 exp_put(exp);
640 fhp->fh_export = NULL;
641 }
642 return;
643}
644
645/*
646 * Shorthand for dprintk()'s
647 */
648char * SVCFH_fmt(struct svc_fh *fhp)
649{
650 struct knfsd_fh *fh = &fhp->fh_handle;
651
652 static char buf[80];
653 sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
654 fh->fh_size,
655 fh->fh_base.fh_pad[0],
656 fh->fh_base.fh_pad[1],
657 fh->fh_base.fh_pad[2],
658 fh->fh_base.fh_pad[3],
659 fh->fh_base.fh_pad[4],
660 fh->fh_base.fh_pad[5]);
661 return buf;
662}
663
664enum fsid_source fsid_source(struct svc_fh *fhp)
665{
666 if (fhp->fh_handle.fh_version != 1)
667 return FSIDSOURCE_DEV;
668 switch(fhp->fh_handle.fh_fsid_type) {
669 case FSID_DEV:
670 case FSID_ENCODE_DEV:
671 case FSID_MAJOR_MINOR:
672 if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
673 return FSIDSOURCE_DEV;
674 break;
675 case FSID_NUM:
676 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
677 return FSIDSOURCE_FSID;
678 break;
679 default:
680 break;
681 }
682 /* either a UUID type filehandle, or the filehandle doesn't
683 * match the export.
684 */
685 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
686 return FSIDSOURCE_FSID;
687 if (fhp->fh_export->ex_uuid)
688 return FSIDSOURCE_UUID;
689 return FSIDSOURCE_DEV;
690}
1/*
2 * NFS server file handle treatment.
3 *
4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
5 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
6 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
7 * ... and again Southern-Winter 2001 to support export_operations
8 */
9
10#include <linux/exportfs.h>
11
12#include <linux/sunrpc/svcauth_gss.h>
13#include "nfsd.h"
14#include "vfs.h"
15#include "auth.h"
16
17#define NFSDDBG_FACILITY NFSDDBG_FH
18
19
20/*
21 * our acceptability function.
22 * if NOSUBTREECHECK, accept anything
23 * if not, require that we can walk up to exp->ex_dentry
24 * doing some checks on the 'x' bits
25 */
26static int nfsd_acceptable(void *expv, struct dentry *dentry)
27{
28 struct svc_export *exp = expv;
29 int rv;
30 struct dentry *tdentry;
31 struct dentry *parent;
32
33 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
34 return 1;
35
36 tdentry = dget(dentry);
37 while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
38 /* make sure parents give x permission to user */
39 int err;
40 parent = dget_parent(tdentry);
41 err = inode_permission(d_inode(parent), MAY_EXEC);
42 if (err < 0) {
43 dput(parent);
44 break;
45 }
46 dput(tdentry);
47 tdentry = parent;
48 }
49 if (tdentry != exp->ex_path.dentry)
50 dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
51 rv = (tdentry == exp->ex_path.dentry);
52 dput(tdentry);
53 return rv;
54}
55
56/* Type check. The correct error return for type mismatches does not seem to be
57 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
58 * comment in the NFSv3 spec says this is incorrect (implementation notes for
59 * the write call).
60 */
61static inline __be32
62nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, umode_t requested)
63{
64 mode &= S_IFMT;
65
66 if (requested == 0) /* the caller doesn't care */
67 return nfs_ok;
68 if (mode == requested)
69 return nfs_ok;
70 /*
71 * v4 has an error more specific than err_notdir which we should
72 * return in preference to err_notdir:
73 */
74 if (rqstp->rq_vers == 4 && mode == S_IFLNK)
75 return nfserr_symlink;
76 if (requested == S_IFDIR)
77 return nfserr_notdir;
78 if (mode == S_IFDIR)
79 return nfserr_isdir;
80 return nfserr_inval;
81}
82
83static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
84 struct svc_export *exp)
85{
86 int flags = nfsexp_flags(rqstp, exp);
87
88 /* Check if the request originated from a secure port. */
89 if (!test_bit(RQ_SECURE, &rqstp->rq_flags) && !(flags & NFSEXP_INSECURE_PORT)) {
90 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
91 dprintk("nfsd: request from insecure port %s!\n",
92 svc_print_addr(rqstp, buf, sizeof(buf)));
93 return nfserr_perm;
94 }
95
96 /* Set user creds for this exportpoint */
97 return nfserrno(nfsd_setuser(rqstp, exp));
98}
99
100static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
101 struct dentry *dentry, struct svc_export *exp)
102{
103 if (!(exp->ex_flags & NFSEXP_V4ROOT))
104 return nfs_ok;
105 /*
106 * v2/v3 clients have no need for the V4ROOT export--they use
107 * the mount protocl instead; also, further V4ROOT checks may be
108 * in v4-specific code, in which case v2/v3 clients could bypass
109 * them.
110 */
111 if (!nfsd_v4client(rqstp))
112 return nfserr_stale;
113 /*
114 * We're exposing only the directories and symlinks that have to be
115 * traversed on the way to real exports:
116 */
117 if (unlikely(!d_is_dir(dentry) &&
118 !d_is_symlink(dentry)))
119 return nfserr_stale;
120 /*
121 * A pseudoroot export gives permission to access only one
122 * single directory; the kernel has to make another upcall
123 * before granting access to anything else under it:
124 */
125 if (unlikely(dentry != exp->ex_path.dentry))
126 return nfserr_stale;
127 return nfs_ok;
128}
129
130/*
131 * Use the given filehandle to look up the corresponding export and
132 * dentry. On success, the results are used to set fh_export and
133 * fh_dentry.
134 */
135static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
136{
137 struct knfsd_fh *fh = &fhp->fh_handle;
138 struct fid *fid = NULL, sfid;
139 struct svc_export *exp;
140 struct dentry *dentry;
141 int fileid_type;
142 int data_left = fh->fh_size/4;
143 __be32 error;
144
145 error = nfserr_stale;
146 if (rqstp->rq_vers > 2)
147 error = nfserr_badhandle;
148 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
149 return nfserr_nofilehandle;
150
151 if (fh->fh_version == 1) {
152 int len;
153
154 if (--data_left < 0)
155 return error;
156 if (fh->fh_auth_type != 0)
157 return error;
158 len = key_len(fh->fh_fsid_type) / 4;
159 if (len == 0)
160 return error;
161 if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
162 /* deprecated, convert to type 3 */
163 len = key_len(FSID_ENCODE_DEV)/4;
164 fh->fh_fsid_type = FSID_ENCODE_DEV;
165 /*
166 * struct knfsd_fh uses host-endian fields, which are
167 * sometimes used to hold net-endian values. This
168 * confuses sparse, so we must use __force here to
169 * keep it from complaining.
170 */
171 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
172 ntohl((__force __be32)fh->fh_fsid[1])));
173 fh->fh_fsid[1] = fh->fh_fsid[2];
174 }
175 data_left -= len;
176 if (data_left < 0)
177 return error;
178 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
179 fid = (struct fid *)(fh->fh_fsid + len);
180 } else {
181 __u32 tfh[2];
182 dev_t xdev;
183 ino_t xino;
184
185 if (fh->fh_size != NFS_FHSIZE)
186 return error;
187 /* assume old filehandle format */
188 xdev = old_decode_dev(fh->ofh_xdev);
189 xino = u32_to_ino_t(fh->ofh_xino);
190 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
191 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
192 }
193
194 error = nfserr_stale;
195 if (PTR_ERR(exp) == -ENOENT)
196 return error;
197
198 if (IS_ERR(exp))
199 return nfserrno(PTR_ERR(exp));
200
201 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
202 /* Elevate privileges so that the lack of 'r' or 'x'
203 * permission on some parent directory will
204 * not stop exportfs_decode_fh from being able
205 * to reconnect a directory into the dentry cache.
206 * The same problem can affect "SUBTREECHECK" exports,
207 * but as nfsd_acceptable depends on correct
208 * access control settings being in effect, we cannot
209 * fix that case easily.
210 */
211 struct cred *new = prepare_creds();
212 if (!new) {
213 error = nfserrno(-ENOMEM);
214 goto out;
215 }
216 new->cap_effective =
217 cap_raise_nfsd_set(new->cap_effective,
218 new->cap_permitted);
219 put_cred(override_creds(new));
220 put_cred(new);
221 } else {
222 error = nfsd_setuser_and_check_port(rqstp, exp);
223 if (error)
224 goto out;
225 }
226
227 /*
228 * Look up the dentry using the NFS file handle.
229 */
230 error = nfserr_stale;
231 if (rqstp->rq_vers > 2)
232 error = nfserr_badhandle;
233
234 if (fh->fh_version != 1) {
235 sfid.i32.ino = fh->ofh_ino;
236 sfid.i32.gen = fh->ofh_generation;
237 sfid.i32.parent_ino = fh->ofh_dirino;
238 fid = &sfid;
239 data_left = 3;
240 if (fh->ofh_dirino == 0)
241 fileid_type = FILEID_INO32_GEN;
242 else
243 fileid_type = FILEID_INO32_GEN_PARENT;
244 } else
245 fileid_type = fh->fh_fileid_type;
246
247 if (fileid_type == FILEID_ROOT)
248 dentry = dget(exp->ex_path.dentry);
249 else {
250 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
251 data_left, fileid_type,
252 nfsd_acceptable, exp);
253 }
254 if (dentry == NULL)
255 goto out;
256 if (IS_ERR(dentry)) {
257 if (PTR_ERR(dentry) != -EINVAL)
258 error = nfserrno(PTR_ERR(dentry));
259 goto out;
260 }
261
262 if (d_is_dir(dentry) &&
263 (dentry->d_flags & DCACHE_DISCONNECTED)) {
264 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
265 dentry);
266 }
267
268 fhp->fh_dentry = dentry;
269 fhp->fh_export = exp;
270 return 0;
271out:
272 exp_put(exp);
273 return error;
274}
275
276/**
277 * fh_verify - filehandle lookup and access checking
278 * @rqstp: pointer to current rpc request
279 * @fhp: filehandle to be verified
280 * @type: expected type of object pointed to by filehandle
281 * @access: type of access needed to object
282 *
283 * Look up a dentry from the on-the-wire filehandle, check the client's
284 * access to the export, and set the current task's credentials.
285 *
286 * Regardless of success or failure of fh_verify(), fh_put() should be
287 * called on @fhp when the caller is finished with the filehandle.
288 *
289 * fh_verify() may be called multiple times on a given filehandle, for
290 * example, when processing an NFSv4 compound. The first call will look
291 * up a dentry using the on-the-wire filehandle. Subsequent calls will
292 * skip the lookup and just perform the other checks and possibly change
293 * the current task's credentials.
294 *
295 * @type specifies the type of object expected using one of the S_IF*
296 * constants defined in include/linux/stat.h. The caller may use zero
297 * to indicate that it doesn't care, or a negative integer to indicate
298 * that it expects something not of the given type.
299 *
300 * @access is formed from the NFSD_MAY_* constants defined in
301 * include/linux/nfsd/nfsd.h.
302 */
303__be32
304fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
305{
306 struct svc_export *exp;
307 struct dentry *dentry;
308 __be32 error;
309
310 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
311
312 if (!fhp->fh_dentry) {
313 error = nfsd_set_fh_dentry(rqstp, fhp);
314 if (error)
315 goto out;
316 }
317 dentry = fhp->fh_dentry;
318 exp = fhp->fh_export;
319 /*
320 * We still have to do all these permission checks, even when
321 * fh_dentry is already set:
322 * - fh_verify may be called multiple times with different
323 * "access" arguments (e.g. nfsd_proc_create calls
324 * fh_verify(...,NFSD_MAY_EXEC) first, then later (in
325 * nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
326 * - in the NFSv4 case, the filehandle may have been filled
327 * in by fh_compose, and given a dentry, but further
328 * compound operations performed with that filehandle
329 * still need permissions checks. In the worst case, a
330 * mountpoint crossing may have changed the export
331 * options, and we may now need to use a different uid
332 * (for example, if different id-squashing options are in
333 * effect on the new filesystem).
334 */
335 error = check_pseudo_root(rqstp, dentry, exp);
336 if (error)
337 goto out;
338
339 error = nfsd_setuser_and_check_port(rqstp, exp);
340 if (error)
341 goto out;
342
343 error = nfsd_mode_check(rqstp, d_inode(dentry)->i_mode, type);
344 if (error)
345 goto out;
346
347 /*
348 * pseudoflavor restrictions are not enforced on NLM,
349 * which clients virtually always use auth_sys for,
350 * even while using RPCSEC_GSS for NFS.
351 */
352 if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
353 goto skip_pseudoflavor_check;
354 /*
355 * Clients may expect to be able to use auth_sys during mount,
356 * even if they use gss for everything else; see section 2.3.2
357 * of rfc 2623.
358 */
359 if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
360 && exp->ex_path.dentry == dentry)
361 goto skip_pseudoflavor_check;
362
363 error = check_nfsd_access(exp, rqstp);
364 if (error)
365 goto out;
366
367skip_pseudoflavor_check:
368 /* Finally, check access permissions. */
369 error = nfsd_permission(rqstp, exp, dentry, access);
370
371 if (error) {
372 dprintk("fh_verify: %pd2 permission failure, "
373 "acc=%x, error=%d\n",
374 dentry,
375 access, ntohl(error));
376 }
377out:
378 if (error == nfserr_stale)
379 nfsdstats.fh_stale++;
380 return error;
381}
382
383
384/*
385 * Compose a file handle for an NFS reply.
386 *
387 * Note that when first composed, the dentry may not yet have
388 * an inode. In this case a call to fh_update should be made
389 * before the fh goes out on the wire ...
390 */
391static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
392 struct dentry *dentry)
393{
394 if (dentry != exp->ex_path.dentry) {
395 struct fid *fid = (struct fid *)
396 (fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
397 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
398 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
399
400 fhp->fh_handle.fh_fileid_type =
401 exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
402 fhp->fh_handle.fh_size += maxsize * 4;
403 } else {
404 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
405 }
406}
407
408/*
409 * for composing old style file handles
410 */
411static inline void _fh_update_old(struct dentry *dentry,
412 struct svc_export *exp,
413 struct knfsd_fh *fh)
414{
415 fh->ofh_ino = ino_t_to_u32(d_inode(dentry)->i_ino);
416 fh->ofh_generation = d_inode(dentry)->i_generation;
417 if (d_is_dir(dentry) ||
418 (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
419 fh->ofh_dirino = 0;
420}
421
422static bool is_root_export(struct svc_export *exp)
423{
424 return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
425}
426
427static struct super_block *exp_sb(struct svc_export *exp)
428{
429 return d_inode(exp->ex_path.dentry)->i_sb;
430}
431
432static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
433{
434 switch (fsid_type) {
435 case FSID_DEV:
436 if (!old_valid_dev(exp_sb(exp)->s_dev))
437 return 0;
438 /* FALL THROUGH */
439 case FSID_MAJOR_MINOR:
440 case FSID_ENCODE_DEV:
441 return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
442 case FSID_NUM:
443 return exp->ex_flags & NFSEXP_FSID;
444 case FSID_UUID8:
445 case FSID_UUID16:
446 if (!is_root_export(exp))
447 return 0;
448 /* fall through */
449 case FSID_UUID4_INUM:
450 case FSID_UUID16_INUM:
451 return exp->ex_uuid != NULL;
452 }
453 return 1;
454}
455
456
457static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
458{
459 u8 version;
460 u8 fsid_type;
461retry:
462 version = 1;
463 if (ref_fh && ref_fh->fh_export == exp) {
464 version = ref_fh->fh_handle.fh_version;
465 fsid_type = ref_fh->fh_handle.fh_fsid_type;
466
467 ref_fh = NULL;
468
469 switch (version) {
470 case 0xca:
471 fsid_type = FSID_DEV;
472 break;
473 case 1:
474 break;
475 default:
476 goto retry;
477 }
478
479 /*
480 * As the fsid -> filesystem mapping was guided by
481 * user-space, there is no guarantee that the filesystem
482 * actually supports that fsid type. If it doesn't we
483 * loop around again without ref_fh set.
484 */
485 if (!fsid_type_ok_for_exp(fsid_type, exp))
486 goto retry;
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 (is_root_export(exp))
492 fsid_type = FSID_UUID16;
493 else
494 fsid_type = FSID_UUID16_INUM;
495 } else {
496 if (is_root_export(exp))
497 fsid_type = FSID_UUID8;
498 else
499 fsid_type = FSID_UUID4_INUM;
500 }
501 } else if (!old_valid_dev(exp_sb(exp)->s_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 fhp->fh_handle.fh_version = version;
507 if (version)
508 fhp->fh_handle.fh_fsid_type = fsid_type;
509}
510
511__be32
512fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
513 struct svc_fh *ref_fh)
514{
515 /* ref_fh is a reference file handle.
516 * if it is non-null and for the same filesystem, then we should compose
517 * a filehandle which is of the same version, where possible.
518 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
519 * Then create a 32byte filehandle using nfs_fhbase_old
520 *
521 */
522
523 struct inode * inode = d_inode(dentry);
524 dev_t ex_dev = exp_sb(exp)->s_dev;
525
526 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
527 MAJOR(ex_dev), MINOR(ex_dev),
528 (long) d_inode(exp->ex_path.dentry)->i_ino,
529 dentry,
530 (inode ? inode->i_ino : 0));
531
532 /* Choose filehandle version and fsid type based on
533 * the reference filehandle (if it is in the same export)
534 * or the export options.
535 */
536 set_version_and_fsid_type(fhp, exp, ref_fh);
537
538 if (ref_fh == fhp)
539 fh_put(ref_fh);
540
541 if (fhp->fh_locked || fhp->fh_dentry) {
542 printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
543 dentry);
544 }
545 if (fhp->fh_maxsize < NFS_FHSIZE)
546 printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
547 fhp->fh_maxsize,
548 dentry);
549
550 fhp->fh_dentry = dget(dentry); /* our internal copy */
551 fhp->fh_export = exp_get(exp);
552
553 if (fhp->fh_handle.fh_version == 0xca) {
554 /* old style filehandle please */
555 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
556 fhp->fh_handle.fh_size = NFS_FHSIZE;
557 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
558 fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
559 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
560 fhp->fh_handle.ofh_xino =
561 ino_t_to_u32(d_inode(exp->ex_path.dentry)->i_ino);
562 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
563 if (inode)
564 _fh_update_old(dentry, exp, &fhp->fh_handle);
565 } else {
566 fhp->fh_handle.fh_size =
567 key_len(fhp->fh_handle.fh_fsid_type) + 4;
568 fhp->fh_handle.fh_auth_type = 0;
569
570 mk_fsid(fhp->fh_handle.fh_fsid_type,
571 fhp->fh_handle.fh_fsid,
572 ex_dev,
573 d_inode(exp->ex_path.dentry)->i_ino,
574 exp->ex_fsid, exp->ex_uuid);
575
576 if (inode)
577 _fh_update(fhp, exp, dentry);
578 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
579 fh_put(fhp);
580 return nfserr_opnotsupp;
581 }
582 }
583
584 return 0;
585}
586
587/*
588 * Update file handle information after changing a dentry.
589 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
590 */
591__be32
592fh_update(struct svc_fh *fhp)
593{
594 struct dentry *dentry;
595
596 if (!fhp->fh_dentry)
597 goto out_bad;
598
599 dentry = fhp->fh_dentry;
600 if (d_really_is_negative(dentry))
601 goto out_negative;
602 if (fhp->fh_handle.fh_version != 1) {
603 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
604 } else {
605 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
606 return 0;
607
608 _fh_update(fhp, fhp->fh_export, dentry);
609 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
610 return nfserr_opnotsupp;
611 }
612 return 0;
613out_bad:
614 printk(KERN_ERR "fh_update: fh not verified!\n");
615 return nfserr_serverfault;
616out_negative:
617 printk(KERN_ERR "fh_update: %pd2 still negative!\n",
618 dentry);
619 return nfserr_serverfault;
620}
621
622/*
623 * Release a file handle.
624 */
625void
626fh_put(struct svc_fh *fhp)
627{
628 struct dentry * dentry = fhp->fh_dentry;
629 struct svc_export * exp = fhp->fh_export;
630 if (dentry) {
631 fh_unlock(fhp);
632 fhp->fh_dentry = NULL;
633 dput(dentry);
634 fh_clear_wcc(fhp);
635 }
636 fh_drop_write(fhp);
637 if (exp) {
638 exp_put(exp);
639 fhp->fh_export = NULL;
640 }
641 return;
642}
643
644/*
645 * Shorthand for dprintk()'s
646 */
647char * SVCFH_fmt(struct svc_fh *fhp)
648{
649 struct knfsd_fh *fh = &fhp->fh_handle;
650
651 static char buf[80];
652 sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
653 fh->fh_size,
654 fh->fh_base.fh_pad[0],
655 fh->fh_base.fh_pad[1],
656 fh->fh_base.fh_pad[2],
657 fh->fh_base.fh_pad[3],
658 fh->fh_base.fh_pad[4],
659 fh->fh_base.fh_pad[5]);
660 return buf;
661}
662
663enum fsid_source fsid_source(struct svc_fh *fhp)
664{
665 if (fhp->fh_handle.fh_version != 1)
666 return FSIDSOURCE_DEV;
667 switch(fhp->fh_handle.fh_fsid_type) {
668 case FSID_DEV:
669 case FSID_ENCODE_DEV:
670 case FSID_MAJOR_MINOR:
671 if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
672 return FSIDSOURCE_DEV;
673 break;
674 case FSID_NUM:
675 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
676 return FSIDSOURCE_FSID;
677 break;
678 default:
679 break;
680 }
681 /* either a UUID type filehandle, or the filehandle doesn't
682 * match the export.
683 */
684 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
685 return FSIDSOURCE_FSID;
686 if (fhp->fh_export->ex_uuid)
687 return FSIDSOURCE_UUID;
688 return FSIDSOURCE_DEV;
689}