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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * NFS server file handle treatment.
4 *
5 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
6 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
7 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
8 * ... and again Southern-Winter 2001 to support export_operations
9 */
10
11#include <linux/exportfs.h>
12
13#include <linux/sunrpc/svcauth_gss.h>
14#include "nfsd.h"
15#include "vfs.h"
16#include "auth.h"
17#include "trace.h"
18
19#define NFSDDBG_FACILITY NFSDDBG_FH
20
21
22/*
23 * our acceptability function.
24 * if NOSUBTREECHECK, accept anything
25 * if not, require that we can walk up to exp->ex_dentry
26 * doing some checks on the 'x' bits
27 */
28static int nfsd_acceptable(void *expv, struct dentry *dentry)
29{
30 struct svc_export *exp = expv;
31 int rv;
32 struct dentry *tdentry;
33 struct dentry *parent;
34
35 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
36 return 1;
37
38 tdentry = dget(dentry);
39 while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
40 /* make sure parents give x permission to user */
41 int err;
42 parent = dget_parent(tdentry);
43 err = inode_permission(&init_user_ns,
44 d_inode(parent), MAY_EXEC);
45 if (err < 0) {
46 dput(parent);
47 break;
48 }
49 dput(tdentry);
50 tdentry = parent;
51 }
52 if (tdentry != exp->ex_path.dentry)
53 dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
54 rv = (tdentry == exp->ex_path.dentry);
55 dput(tdentry);
56 return rv;
57}
58
59/* Type check. The correct error return for type mismatches does not seem to be
60 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
61 * comment in the NFSv3 spec says this is incorrect (implementation notes for
62 * the write call).
63 */
64static inline __be32
65nfsd_mode_check(struct svc_rqst *rqstp, struct dentry *dentry,
66 umode_t requested)
67{
68 umode_t mode = d_inode(dentry)->i_mode & S_IFMT;
69
70 if (requested == 0) /* the caller doesn't care */
71 return nfs_ok;
72 if (mode == requested) {
73 if (mode == S_IFDIR && !d_can_lookup(dentry)) {
74 WARN_ON_ONCE(1);
75 return nfserr_notdir;
76 }
77 return nfs_ok;
78 }
79 /*
80 * v4 has an error more specific than err_notdir which we should
81 * return in preference to err_notdir:
82 */
83 if (rqstp->rq_vers == 4 && mode == S_IFLNK)
84 return nfserr_symlink;
85 if (requested == S_IFDIR)
86 return nfserr_notdir;
87 if (mode == S_IFDIR)
88 return nfserr_isdir;
89 return nfserr_inval;
90}
91
92static bool nfsd_originating_port_ok(struct svc_rqst *rqstp, int flags)
93{
94 if (flags & NFSEXP_INSECURE_PORT)
95 return true;
96 /* We don't require gss requests to use low ports: */
97 if (rqstp->rq_cred.cr_flavor >= RPC_AUTH_GSS)
98 return true;
99 return test_bit(RQ_SECURE, &rqstp->rq_flags);
100}
101
102static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
103 struct svc_export *exp)
104{
105 int flags = nfsexp_flags(rqstp, exp);
106
107 /* Check if the request originated from a secure port. */
108 if (!nfsd_originating_port_ok(rqstp, flags)) {
109 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
110 dprintk("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
119static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
120 struct dentry *dentry, struct svc_export *exp)
121{
122 if (!(exp->ex_flags & NFSEXP_V4ROOT))
123 return nfs_ok;
124 /*
125 * v2/v3 clients have no need for the V4ROOT export--they use
126 * the mount protocl instead; also, further V4ROOT checks may be
127 * in v4-specific code, in which case v2/v3 clients could bypass
128 * them.
129 */
130 if (!nfsd_v4client(rqstp))
131 return nfserr_stale;
132 /*
133 * We're exposing only the directories and symlinks that have to be
134 * traversed on the way to real exports:
135 */
136 if (unlikely(!d_is_dir(dentry) &&
137 !d_is_symlink(dentry)))
138 return nfserr_stale;
139 /*
140 * A pseudoroot export gives permission to access only one
141 * single directory; the kernel has to make another upcall
142 * before granting access to anything else under it:
143 */
144 if (unlikely(dentry != exp->ex_path.dentry))
145 return nfserr_stale;
146 return nfs_ok;
147}
148
149/*
150 * Use the given filehandle to look up the corresponding export and
151 * dentry. On success, the results are used to set fh_export and
152 * fh_dentry.
153 */
154static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
155{
156 struct knfsd_fh *fh = &fhp->fh_handle;
157 struct fid *fid = NULL, sfid;
158 struct svc_export *exp;
159 struct dentry *dentry;
160 int fileid_type;
161 int data_left = fh->fh_size/4;
162 __be32 error;
163
164 error = nfserr_stale;
165 if (rqstp->rq_vers > 2)
166 error = nfserr_badhandle;
167 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
168 return nfserr_nofilehandle;
169
170 if (fh->fh_version == 1) {
171 int len;
172
173 if (--data_left < 0)
174 return error;
175 if (fh->fh_auth_type != 0)
176 return error;
177 len = key_len(fh->fh_fsid_type) / 4;
178 if (len == 0)
179 return error;
180 if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
181 /* deprecated, convert to type 3 */
182 len = key_len(FSID_ENCODE_DEV)/4;
183 fh->fh_fsid_type = FSID_ENCODE_DEV;
184 /*
185 * struct knfsd_fh uses host-endian fields, which are
186 * sometimes used to hold net-endian values. This
187 * confuses sparse, so we must use __force here to
188 * keep it from complaining.
189 */
190 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
191 ntohl((__force __be32)fh->fh_fsid[1])));
192 fh->fh_fsid[1] = fh->fh_fsid[2];
193 }
194 data_left -= len;
195 if (data_left < 0)
196 return error;
197 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
198 fid = (struct fid *)(fh->fh_fsid + len);
199 } else {
200 __u32 tfh[2];
201 dev_t xdev;
202 ino_t xino;
203
204 if (fh->fh_size != NFS_FHSIZE)
205 return error;
206 /* assume old filehandle format */
207 xdev = old_decode_dev(fh->ofh_xdev);
208 xino = u32_to_ino_t(fh->ofh_xino);
209 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
210 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
211 }
212
213 error = nfserr_stale;
214 if (IS_ERR(exp)) {
215 trace_nfsd_set_fh_dentry_badexport(rqstp, fhp, PTR_ERR(exp));
216
217 if (PTR_ERR(exp) == -ENOENT)
218 return error;
219
220 return nfserrno(PTR_ERR(exp));
221 }
222
223 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
224 /* Elevate privileges so that the lack of 'r' or 'x'
225 * permission on some parent directory will
226 * not stop exportfs_decode_fh from being able
227 * to reconnect a directory into the dentry cache.
228 * The same problem can affect "SUBTREECHECK" exports,
229 * but as nfsd_acceptable depends on correct
230 * access control settings being in effect, we cannot
231 * fix that case easily.
232 */
233 struct cred *new = prepare_creds();
234 if (!new) {
235 error = nfserrno(-ENOMEM);
236 goto out;
237 }
238 new->cap_effective =
239 cap_raise_nfsd_set(new->cap_effective,
240 new->cap_permitted);
241 put_cred(override_creds(new));
242 put_cred(new);
243 } else {
244 error = nfsd_setuser_and_check_port(rqstp, exp);
245 if (error)
246 goto out;
247 }
248
249 /*
250 * Look up the dentry using the NFS file handle.
251 */
252 error = nfserr_stale;
253 if (rqstp->rq_vers > 2)
254 error = nfserr_badhandle;
255
256 if (fh->fh_version != 1) {
257 sfid.i32.ino = fh->ofh_ino;
258 sfid.i32.gen = fh->ofh_generation;
259 sfid.i32.parent_ino = fh->ofh_dirino;
260 fid = &sfid;
261 data_left = 3;
262 if (fh->ofh_dirino == 0)
263 fileid_type = FILEID_INO32_GEN;
264 else
265 fileid_type = FILEID_INO32_GEN_PARENT;
266 } else
267 fileid_type = fh->fh_fileid_type;
268
269 if (fileid_type == FILEID_ROOT)
270 dentry = dget(exp->ex_path.dentry);
271 else {
272 dentry = exportfs_decode_fh_raw(exp->ex_path.mnt, fid,
273 data_left, fileid_type,
274 nfsd_acceptable, exp);
275 if (IS_ERR_OR_NULL(dentry)) {
276 trace_nfsd_set_fh_dentry_badhandle(rqstp, fhp,
277 dentry ? PTR_ERR(dentry) : -ESTALE);
278 switch (PTR_ERR(dentry)) {
279 case -ENOMEM:
280 case -ETIMEDOUT:
281 break;
282 default:
283 dentry = ERR_PTR(-ESTALE);
284 }
285 }
286 }
287 if (dentry == NULL)
288 goto out;
289 if (IS_ERR(dentry)) {
290 if (PTR_ERR(dentry) != -EINVAL)
291 error = nfserrno(PTR_ERR(dentry));
292 goto out;
293 }
294
295 if (d_is_dir(dentry) &&
296 (dentry->d_flags & DCACHE_DISCONNECTED)) {
297 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
298 dentry);
299 }
300
301 fhp->fh_dentry = dentry;
302 fhp->fh_export = exp;
303
304 switch (rqstp->rq_vers) {
305 case 4:
306 if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOATOMIC_ATTR)
307 fhp->fh_no_atomic_attr = true;
308 break;
309 case 3:
310 if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOWCC)
311 fhp->fh_no_wcc = true;
312 break;
313 case 2:
314 fhp->fh_no_wcc = true;
315 }
316
317 return 0;
318out:
319 exp_put(exp);
320 return error;
321}
322
323/**
324 * fh_verify - filehandle lookup and access checking
325 * @rqstp: pointer to current rpc request
326 * @fhp: filehandle to be verified
327 * @type: expected type of object pointed to by filehandle
328 * @access: type of access needed to object
329 *
330 * Look up a dentry from the on-the-wire filehandle, check the client's
331 * access to the export, and set the current task's credentials.
332 *
333 * Regardless of success or failure of fh_verify(), fh_put() should be
334 * called on @fhp when the caller is finished with the filehandle.
335 *
336 * fh_verify() may be called multiple times on a given filehandle, for
337 * example, when processing an NFSv4 compound. The first call will look
338 * up a dentry using the on-the-wire filehandle. Subsequent calls will
339 * skip the lookup and just perform the other checks and possibly change
340 * the current task's credentials.
341 *
342 * @type specifies the type of object expected using one of the S_IF*
343 * constants defined in include/linux/stat.h. The caller may use zero
344 * to indicate that it doesn't care, or a negative integer to indicate
345 * that it expects something not of the given type.
346 *
347 * @access is formed from the NFSD_MAY_* constants defined in
348 * fs/nfsd/vfs.h.
349 */
350__be32
351fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
352{
353 struct svc_export *exp = NULL;
354 struct dentry *dentry;
355 __be32 error;
356
357 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
358
359 if (!fhp->fh_dentry) {
360 error = nfsd_set_fh_dentry(rqstp, fhp);
361 if (error)
362 goto out;
363 }
364 dentry = fhp->fh_dentry;
365 exp = fhp->fh_export;
366 /*
367 * We still have to do all these permission checks, even when
368 * fh_dentry is already set:
369 * - fh_verify may be called multiple times with different
370 * "access" arguments (e.g. nfsd_proc_create calls
371 * fh_verify(...,NFSD_MAY_EXEC) first, then later (in
372 * nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
373 * - in the NFSv4 case, the filehandle may have been filled
374 * in by fh_compose, and given a dentry, but further
375 * compound operations performed with that filehandle
376 * still need permissions checks. In the worst case, a
377 * mountpoint crossing may have changed the export
378 * options, and we may now need to use a different uid
379 * (for example, if different id-squashing options are in
380 * effect on the new filesystem).
381 */
382 error = check_pseudo_root(rqstp, dentry, exp);
383 if (error)
384 goto out;
385
386 error = nfsd_setuser_and_check_port(rqstp, exp);
387 if (error)
388 goto out;
389
390 error = nfsd_mode_check(rqstp, dentry, type);
391 if (error)
392 goto out;
393
394 /*
395 * pseudoflavor restrictions are not enforced on NLM,
396 * which clients virtually always use auth_sys for,
397 * even while using RPCSEC_GSS for NFS.
398 */
399 if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
400 goto skip_pseudoflavor_check;
401 /*
402 * Clients may expect to be able to use auth_sys during mount,
403 * even if they use gss for everything else; see section 2.3.2
404 * of rfc 2623.
405 */
406 if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
407 && exp->ex_path.dentry == dentry)
408 goto skip_pseudoflavor_check;
409
410 error = check_nfsd_access(exp, rqstp);
411 if (error)
412 goto out;
413
414skip_pseudoflavor_check:
415 /* Finally, check access permissions. */
416 error = nfsd_permission(rqstp, exp, dentry, access);
417
418 if (error) {
419 dprintk("fh_verify: %pd2 permission failure, "
420 "acc=%x, error=%d\n",
421 dentry,
422 access, ntohl(error));
423 }
424out:
425 if (error == nfserr_stale)
426 nfsd_stats_fh_stale_inc(exp);
427 return error;
428}
429
430
431/*
432 * Compose a file handle for an NFS reply.
433 *
434 * Note that when first composed, the dentry may not yet have
435 * an inode. In this case a call to fh_update should be made
436 * before the fh goes out on the wire ...
437 */
438static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
439 struct dentry *dentry)
440{
441 if (dentry != exp->ex_path.dentry) {
442 struct fid *fid = (struct fid *)
443 (fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
444 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
445 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
446
447 fhp->fh_handle.fh_fileid_type =
448 exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
449 fhp->fh_handle.fh_size += maxsize * 4;
450 } else {
451 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
452 }
453}
454
455/*
456 * for composing old style file handles
457 */
458static inline void _fh_update_old(struct dentry *dentry,
459 struct svc_export *exp,
460 struct knfsd_fh *fh)
461{
462 fh->ofh_ino = ino_t_to_u32(d_inode(dentry)->i_ino);
463 fh->ofh_generation = d_inode(dentry)->i_generation;
464 if (d_is_dir(dentry) ||
465 (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
466 fh->ofh_dirino = 0;
467}
468
469static bool is_root_export(struct svc_export *exp)
470{
471 return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
472}
473
474static struct super_block *exp_sb(struct svc_export *exp)
475{
476 return exp->ex_path.dentry->d_sb;
477}
478
479static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
480{
481 switch (fsid_type) {
482 case FSID_DEV:
483 if (!old_valid_dev(exp_sb(exp)->s_dev))
484 return false;
485 fallthrough;
486 case FSID_MAJOR_MINOR:
487 case FSID_ENCODE_DEV:
488 return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
489 case FSID_NUM:
490 return exp->ex_flags & NFSEXP_FSID;
491 case FSID_UUID8:
492 case FSID_UUID16:
493 if (!is_root_export(exp))
494 return false;
495 fallthrough;
496 case FSID_UUID4_INUM:
497 case FSID_UUID16_INUM:
498 return exp->ex_uuid != NULL;
499 }
500 return true;
501}
502
503
504static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
505{
506 u8 version;
507 u8 fsid_type;
508retry:
509 version = 1;
510 if (ref_fh && ref_fh->fh_export == exp) {
511 version = ref_fh->fh_handle.fh_version;
512 fsid_type = ref_fh->fh_handle.fh_fsid_type;
513
514 ref_fh = NULL;
515
516 switch (version) {
517 case 0xca:
518 fsid_type = FSID_DEV;
519 break;
520 case 1:
521 break;
522 default:
523 goto retry;
524 }
525
526 /*
527 * As the fsid -> filesystem mapping was guided by
528 * user-space, there is no guarantee that the filesystem
529 * actually supports that fsid type. If it doesn't we
530 * loop around again without ref_fh set.
531 */
532 if (!fsid_type_ok_for_exp(fsid_type, exp))
533 goto retry;
534 } else if (exp->ex_flags & NFSEXP_FSID) {
535 fsid_type = FSID_NUM;
536 } else if (exp->ex_uuid) {
537 if (fhp->fh_maxsize >= 64) {
538 if (is_root_export(exp))
539 fsid_type = FSID_UUID16;
540 else
541 fsid_type = FSID_UUID16_INUM;
542 } else {
543 if (is_root_export(exp))
544 fsid_type = FSID_UUID8;
545 else
546 fsid_type = FSID_UUID4_INUM;
547 }
548 } else if (!old_valid_dev(exp_sb(exp)->s_dev))
549 /* for newer device numbers, we must use a newer fsid format */
550 fsid_type = FSID_ENCODE_DEV;
551 else
552 fsid_type = FSID_DEV;
553 fhp->fh_handle.fh_version = version;
554 if (version)
555 fhp->fh_handle.fh_fsid_type = fsid_type;
556}
557
558__be32
559fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
560 struct svc_fh *ref_fh)
561{
562 /* ref_fh is a reference file handle.
563 * if it is non-null and for the same filesystem, then we should compose
564 * a filehandle which is of the same version, where possible.
565 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
566 * Then create a 32byte filehandle using nfs_fhbase_old
567 *
568 */
569
570 struct inode * inode = d_inode(dentry);
571 dev_t ex_dev = exp_sb(exp)->s_dev;
572
573 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
574 MAJOR(ex_dev), MINOR(ex_dev),
575 (long) d_inode(exp->ex_path.dentry)->i_ino,
576 dentry,
577 (inode ? inode->i_ino : 0));
578
579 /* Choose filehandle version and fsid type based on
580 * the reference filehandle (if it is in the same export)
581 * or the export options.
582 */
583 set_version_and_fsid_type(fhp, exp, ref_fh);
584
585 /* If we have a ref_fh, then copy the fh_no_wcc setting from it. */
586 fhp->fh_no_wcc = ref_fh ? ref_fh->fh_no_wcc : false;
587
588 if (ref_fh == fhp)
589 fh_put(ref_fh);
590
591 if (fhp->fh_locked || fhp->fh_dentry) {
592 printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
593 dentry);
594 }
595 if (fhp->fh_maxsize < NFS_FHSIZE)
596 printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
597 fhp->fh_maxsize,
598 dentry);
599
600 fhp->fh_dentry = dget(dentry); /* our internal copy */
601 fhp->fh_export = exp_get(exp);
602
603 if (fhp->fh_handle.fh_version == 0xca) {
604 /* old style filehandle please */
605 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
606 fhp->fh_handle.fh_size = NFS_FHSIZE;
607 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
608 fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
609 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
610 fhp->fh_handle.ofh_xino =
611 ino_t_to_u32(d_inode(exp->ex_path.dentry)->i_ino);
612 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
613 if (inode)
614 _fh_update_old(dentry, exp, &fhp->fh_handle);
615 } else {
616 fhp->fh_handle.fh_size =
617 key_len(fhp->fh_handle.fh_fsid_type) + 4;
618 fhp->fh_handle.fh_auth_type = 0;
619
620 mk_fsid(fhp->fh_handle.fh_fsid_type,
621 fhp->fh_handle.fh_fsid,
622 ex_dev,
623 d_inode(exp->ex_path.dentry)->i_ino,
624 exp->ex_fsid, exp->ex_uuid);
625
626 if (inode)
627 _fh_update(fhp, exp, dentry);
628 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
629 fh_put(fhp);
630 return nfserr_opnotsupp;
631 }
632 }
633
634 return 0;
635}
636
637/*
638 * Update file handle information after changing a dentry.
639 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
640 */
641__be32
642fh_update(struct svc_fh *fhp)
643{
644 struct dentry *dentry;
645
646 if (!fhp->fh_dentry)
647 goto out_bad;
648
649 dentry = fhp->fh_dentry;
650 if (d_really_is_negative(dentry))
651 goto out_negative;
652 if (fhp->fh_handle.fh_version != 1) {
653 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
654 } else {
655 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
656 return 0;
657
658 _fh_update(fhp, fhp->fh_export, dentry);
659 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
660 return nfserr_opnotsupp;
661 }
662 return 0;
663out_bad:
664 printk(KERN_ERR "fh_update: fh not verified!\n");
665 return nfserr_serverfault;
666out_negative:
667 printk(KERN_ERR "fh_update: %pd2 still negative!\n",
668 dentry);
669 return nfserr_serverfault;
670}
671
672/*
673 * Release a file handle.
674 */
675void
676fh_put(struct svc_fh *fhp)
677{
678 struct dentry * dentry = fhp->fh_dentry;
679 struct svc_export * exp = fhp->fh_export;
680 if (dentry) {
681 fh_unlock(fhp);
682 fhp->fh_dentry = NULL;
683 dput(dentry);
684 fh_clear_wcc(fhp);
685 }
686 fh_drop_write(fhp);
687 if (exp) {
688 exp_put(exp);
689 fhp->fh_export = NULL;
690 }
691 fhp->fh_no_wcc = false;
692 return;
693}
694
695/*
696 * Shorthand for dprintk()'s
697 */
698char * SVCFH_fmt(struct svc_fh *fhp)
699{
700 struct knfsd_fh *fh = &fhp->fh_handle;
701
702 static char buf[80];
703 sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
704 fh->fh_size,
705 fh->fh_base.fh_pad[0],
706 fh->fh_base.fh_pad[1],
707 fh->fh_base.fh_pad[2],
708 fh->fh_base.fh_pad[3],
709 fh->fh_base.fh_pad[4],
710 fh->fh_base.fh_pad[5]);
711 return buf;
712}
713
714enum fsid_source fsid_source(const struct svc_fh *fhp)
715{
716 if (fhp->fh_handle.fh_version != 1)
717 return FSIDSOURCE_DEV;
718 switch(fhp->fh_handle.fh_fsid_type) {
719 case FSID_DEV:
720 case FSID_ENCODE_DEV:
721 case FSID_MAJOR_MINOR:
722 if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
723 return FSIDSOURCE_DEV;
724 break;
725 case FSID_NUM:
726 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
727 return FSIDSOURCE_FSID;
728 break;
729 default:
730 break;
731 }
732 /* either a UUID type filehandle, or the filehandle doesn't
733 * match the export.
734 */
735 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
736 return FSIDSOURCE_FSID;
737 if (fhp->fh_export->ex_uuid)
738 return FSIDSOURCE_UUID;
739 return FSIDSOURCE_DEV;
740}