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 */
nfsd_acceptable(void * expv,struct dentry * dentry)28 static 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 */
64 static inline __be32
nfsd_mode_check(struct svc_rqst * rqstp,struct dentry * dentry,umode_t requested)65 nfsd_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
nfsd_originating_port_ok(struct svc_rqst * rqstp,int flags)92 static 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
nfsd_setuser_and_check_port(struct svc_rqst * rqstp,struct svc_export * exp)102 static __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
check_pseudo_root(struct svc_rqst * rqstp,struct dentry * dentry,struct svc_export * exp)119 static 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 */
nfsd_set_fh_dentry(struct svc_rqst * rqstp,struct svc_fh * fhp)154 static __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;
158 struct svc_export *exp;
159 struct dentry *dentry;
160 int fileid_type;
161 int data_left = fh->fh_size/4;
162 int len;
163 __be32 error;
164
165 error = nfserr_stale;
166 if (rqstp->rq_vers > 2)
167 error = nfserr_badhandle;
168 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
169 return nfserr_nofilehandle;
170
171 if (fh->fh_version != 1)
172 return error;
173
174 if (--data_left < 0)
175 return error;
176 if (fh->fh_auth_type != 0)
177 return error;
178 len = key_len(fh->fh_fsid_type) / 4;
179 if (len == 0)
180 return error;
181 if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
182 /* deprecated, convert to type 3 */
183 len = key_len(FSID_ENCODE_DEV)/4;
184 fh->fh_fsid_type = FSID_ENCODE_DEV;
185 /*
186 * struct knfsd_fh uses host-endian fields, which are
187 * sometimes used to hold net-endian values. This
188 * confuses sparse, so we must use __force here to
189 * keep it from complaining.
190 */
191 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
192 ntohl((__force __be32)fh->fh_fsid[1])));
193 fh->fh_fsid[1] = fh->fh_fsid[2];
194 }
195 data_left -= len;
196 if (data_left < 0)
197 return error;
198 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
199 fid = (struct fid *)(fh->fh_fsid + len);
200
201 error = nfserr_stale;
202 if (IS_ERR(exp)) {
203 trace_nfsd_set_fh_dentry_badexport(rqstp, fhp, PTR_ERR(exp));
204
205 if (PTR_ERR(exp) == -ENOENT)
206 return error;
207
208 return nfserrno(PTR_ERR(exp));
209 }
210
211 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
212 /* Elevate privileges so that the lack of 'r' or 'x'
213 * permission on some parent directory will
214 * not stop exportfs_decode_fh from being able
215 * to reconnect a directory into the dentry cache.
216 * The same problem can affect "SUBTREECHECK" exports,
217 * but as nfsd_acceptable depends on correct
218 * access control settings being in effect, we cannot
219 * fix that case easily.
220 */
221 struct cred *new = prepare_creds();
222 if (!new) {
223 error = nfserrno(-ENOMEM);
224 goto out;
225 }
226 new->cap_effective =
227 cap_raise_nfsd_set(new->cap_effective,
228 new->cap_permitted);
229 put_cred(override_creds(new));
230 put_cred(new);
231 } else {
232 error = nfsd_setuser_and_check_port(rqstp, exp);
233 if (error)
234 goto out;
235 }
236
237 /*
238 * Look up the dentry using the NFS file handle.
239 */
240 error = nfserr_stale;
241 if (rqstp->rq_vers > 2)
242 error = nfserr_badhandle;
243
244 fileid_type = fh->fh_fileid_type;
245
246 if (fileid_type == FILEID_ROOT)
247 dentry = dget(exp->ex_path.dentry);
248 else {
249 dentry = exportfs_decode_fh_raw(exp->ex_path.mnt, fid,
250 data_left, fileid_type,
251 nfsd_acceptable, exp);
252 if (IS_ERR_OR_NULL(dentry)) {
253 trace_nfsd_set_fh_dentry_badhandle(rqstp, fhp,
254 dentry ? PTR_ERR(dentry) : -ESTALE);
255 switch (PTR_ERR(dentry)) {
256 case -ENOMEM:
257 case -ETIMEDOUT:
258 break;
259 default:
260 dentry = ERR_PTR(-ESTALE);
261 }
262 }
263 }
264 if (dentry == NULL)
265 goto out;
266 if (IS_ERR(dentry)) {
267 if (PTR_ERR(dentry) != -EINVAL)
268 error = nfserrno(PTR_ERR(dentry));
269 goto out;
270 }
271
272 if (d_is_dir(dentry) &&
273 (dentry->d_flags & DCACHE_DISCONNECTED)) {
274 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
275 dentry);
276 }
277
278 fhp->fh_dentry = dentry;
279 fhp->fh_export = exp;
280
281 switch (rqstp->rq_vers) {
282 case 4:
283 if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOATOMIC_ATTR)
284 fhp->fh_no_atomic_attr = true;
285 break;
286 case 3:
287 if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOWCC)
288 fhp->fh_no_wcc = true;
289 break;
290 case 2:
291 fhp->fh_no_wcc = true;
292 }
293
294 return 0;
295 out:
296 exp_put(exp);
297 return error;
298 }
299
300 /**
301 * fh_verify - filehandle lookup and access checking
302 * @rqstp: pointer to current rpc request
303 * @fhp: filehandle to be verified
304 * @type: expected type of object pointed to by filehandle
305 * @access: type of access needed to object
306 *
307 * Look up a dentry from the on-the-wire filehandle, check the client's
308 * access to the export, and set the current task's credentials.
309 *
310 * Regardless of success or failure of fh_verify(), fh_put() should be
311 * called on @fhp when the caller is finished with the filehandle.
312 *
313 * fh_verify() may be called multiple times on a given filehandle, for
314 * example, when processing an NFSv4 compound. The first call will look
315 * up a dentry using the on-the-wire filehandle. Subsequent calls will
316 * skip the lookup and just perform the other checks and possibly change
317 * the current task's credentials.
318 *
319 * @type specifies the type of object expected using one of the S_IF*
320 * constants defined in include/linux/stat.h. The caller may use zero
321 * to indicate that it doesn't care, or a negative integer to indicate
322 * that it expects something not of the given type.
323 *
324 * @access is formed from the NFSD_MAY_* constants defined in
325 * fs/nfsd/vfs.h.
326 */
327 __be32
fh_verify(struct svc_rqst * rqstp,struct svc_fh * fhp,umode_t type,int access)328 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
329 {
330 struct svc_export *exp = NULL;
331 struct dentry *dentry;
332 __be32 error;
333
334 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
335
336 if (!fhp->fh_dentry) {
337 error = nfsd_set_fh_dentry(rqstp, fhp);
338 if (error)
339 goto out;
340 }
341 dentry = fhp->fh_dentry;
342 exp = fhp->fh_export;
343 /*
344 * We still have to do all these permission checks, even when
345 * fh_dentry is already set:
346 * - fh_verify may be called multiple times with different
347 * "access" arguments (e.g. nfsd_proc_create calls
348 * fh_verify(...,NFSD_MAY_EXEC) first, then later (in
349 * nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
350 * - in the NFSv4 case, the filehandle may have been filled
351 * in by fh_compose, and given a dentry, but further
352 * compound operations performed with that filehandle
353 * still need permissions checks. In the worst case, a
354 * mountpoint crossing may have changed the export
355 * options, and we may now need to use a different uid
356 * (for example, if different id-squashing options are in
357 * effect on the new filesystem).
358 */
359 error = check_pseudo_root(rqstp, dentry, exp);
360 if (error)
361 goto out;
362
363 error = nfsd_setuser_and_check_port(rqstp, exp);
364 if (error)
365 goto out;
366
367 error = nfsd_mode_check(rqstp, dentry, type);
368 if (error)
369 goto out;
370
371 /*
372 * pseudoflavor restrictions are not enforced on NLM,
373 * which clients virtually always use auth_sys for,
374 * even while using RPCSEC_GSS for NFS.
375 */
376 if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
377 goto skip_pseudoflavor_check;
378 /*
379 * Clients may expect to be able to use auth_sys during mount,
380 * even if they use gss for everything else; see section 2.3.2
381 * of rfc 2623.
382 */
383 if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
384 && exp->ex_path.dentry == dentry)
385 goto skip_pseudoflavor_check;
386
387 error = check_nfsd_access(exp, rqstp);
388 if (error)
389 goto out;
390
391 skip_pseudoflavor_check:
392 /* Finally, check access permissions. */
393 error = nfsd_permission(rqstp, exp, dentry, access);
394
395 if (error) {
396 dprintk("fh_verify: %pd2 permission failure, "
397 "acc=%x, error=%d\n",
398 dentry,
399 access, ntohl(error));
400 }
401 out:
402 if (error == nfserr_stale)
403 nfsd_stats_fh_stale_inc(exp);
404 return error;
405 }
406
407
408 /*
409 * Compose a file handle for an NFS reply.
410 *
411 * Note that when first composed, the dentry may not yet have
412 * an inode. In this case a call to fh_update should be made
413 * before the fh goes out on the wire ...
414 */
_fh_update(struct svc_fh * fhp,struct svc_export * exp,struct dentry * dentry)415 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
416 struct dentry *dentry)
417 {
418 if (dentry != exp->ex_path.dentry) {
419 struct fid *fid = (struct fid *)
420 (fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
421 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
422 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
423
424 fhp->fh_handle.fh_fileid_type =
425 exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
426 fhp->fh_handle.fh_size += maxsize * 4;
427 } else {
428 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
429 }
430 }
431
is_root_export(struct svc_export * exp)432 static bool is_root_export(struct svc_export *exp)
433 {
434 return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
435 }
436
exp_sb(struct svc_export * exp)437 static struct super_block *exp_sb(struct svc_export *exp)
438 {
439 return exp->ex_path.dentry->d_sb;
440 }
441
fsid_type_ok_for_exp(u8 fsid_type,struct svc_export * exp)442 static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
443 {
444 switch (fsid_type) {
445 case FSID_DEV:
446 if (!old_valid_dev(exp_sb(exp)->s_dev))
447 return false;
448 fallthrough;
449 case FSID_MAJOR_MINOR:
450 case FSID_ENCODE_DEV:
451 return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
452 case FSID_NUM:
453 return exp->ex_flags & NFSEXP_FSID;
454 case FSID_UUID8:
455 case FSID_UUID16:
456 if (!is_root_export(exp))
457 return false;
458 fallthrough;
459 case FSID_UUID4_INUM:
460 case FSID_UUID16_INUM:
461 return exp->ex_uuid != NULL;
462 }
463 return true;
464 }
465
466
set_version_and_fsid_type(struct svc_fh * fhp,struct svc_export * exp,struct svc_fh * ref_fh)467 static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
468 {
469 u8 version;
470 u8 fsid_type;
471 retry:
472 version = 1;
473 if (ref_fh && ref_fh->fh_export == exp) {
474 version = ref_fh->fh_handle.fh_version;
475 fsid_type = ref_fh->fh_handle.fh_fsid_type;
476
477 ref_fh = NULL;
478
479 switch (version) {
480 case 0xca:
481 fsid_type = FSID_DEV;
482 break;
483 case 1:
484 break;
485 default:
486 goto retry;
487 }
488
489 /*
490 * As the fsid -> filesystem mapping was guided by
491 * user-space, there is no guarantee that the filesystem
492 * actually supports that fsid type. If it doesn't we
493 * loop around again without ref_fh set.
494 */
495 if (!fsid_type_ok_for_exp(fsid_type, exp))
496 goto retry;
497 } else if (exp->ex_flags & NFSEXP_FSID) {
498 fsid_type = FSID_NUM;
499 } else if (exp->ex_uuid) {
500 if (fhp->fh_maxsize >= 64) {
501 if (is_root_export(exp))
502 fsid_type = FSID_UUID16;
503 else
504 fsid_type = FSID_UUID16_INUM;
505 } else {
506 if (is_root_export(exp))
507 fsid_type = FSID_UUID8;
508 else
509 fsid_type = FSID_UUID4_INUM;
510 }
511 } else if (!old_valid_dev(exp_sb(exp)->s_dev))
512 /* for newer device numbers, we must use a newer fsid format */
513 fsid_type = FSID_ENCODE_DEV;
514 else
515 fsid_type = FSID_DEV;
516 fhp->fh_handle.fh_version = version;
517 if (version)
518 fhp->fh_handle.fh_fsid_type = fsid_type;
519 }
520
521 __be32
fh_compose(struct svc_fh * fhp,struct svc_export * exp,struct dentry * dentry,struct svc_fh * ref_fh)522 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
523 struct svc_fh *ref_fh)
524 {
525 /* ref_fh is a reference file handle.
526 * if it is non-null and for the same filesystem, then we should compose
527 * a filehandle which is of the same version, where possible.
528 */
529
530 struct inode * inode = d_inode(dentry);
531 dev_t ex_dev = exp_sb(exp)->s_dev;
532
533 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
534 MAJOR(ex_dev), MINOR(ex_dev),
535 (long) d_inode(exp->ex_path.dentry)->i_ino,
536 dentry,
537 (inode ? inode->i_ino : 0));
538
539 /* Choose filehandle version and fsid type based on
540 * the reference filehandle (if it is in the same export)
541 * or the export options.
542 */
543 set_version_and_fsid_type(fhp, exp, ref_fh);
544
545 /* If we have a ref_fh, then copy the fh_no_wcc setting from it. */
546 fhp->fh_no_wcc = ref_fh ? ref_fh->fh_no_wcc : false;
547
548 if (ref_fh == fhp)
549 fh_put(ref_fh);
550
551 if (fhp->fh_locked || fhp->fh_dentry) {
552 printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
553 dentry);
554 }
555 if (fhp->fh_maxsize < NFS_FHSIZE)
556 printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
557 fhp->fh_maxsize,
558 dentry);
559
560 fhp->fh_dentry = dget(dentry); /* our internal copy */
561 fhp->fh_export = exp_get(exp);
562
563 fhp->fh_handle.fh_size =
564 key_len(fhp->fh_handle.fh_fsid_type) + 4;
565 fhp->fh_handle.fh_auth_type = 0;
566
567 mk_fsid(fhp->fh_handle.fh_fsid_type,
568 fhp->fh_handle.fh_fsid,
569 ex_dev,
570 d_inode(exp->ex_path.dentry)->i_ino,
571 exp->ex_fsid, exp->ex_uuid);
572
573 if (inode)
574 _fh_update(fhp, exp, dentry);
575 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
576 fh_put(fhp);
577 return nfserr_opnotsupp;
578 }
579
580 return 0;
581 }
582
583 /*
584 * Update file handle information after changing a dentry.
585 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
586 */
587 __be32
fh_update(struct svc_fh * fhp)588 fh_update(struct svc_fh *fhp)
589 {
590 struct dentry *dentry;
591
592 if (!fhp->fh_dentry)
593 goto out_bad;
594
595 dentry = fhp->fh_dentry;
596 if (d_really_is_negative(dentry))
597 goto out_negative;
598 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
599 return 0;
600
601 _fh_update(fhp, fhp->fh_export, dentry);
602 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
603 return nfserr_opnotsupp;
604 return 0;
605 out_bad:
606 printk(KERN_ERR "fh_update: fh not verified!\n");
607 return nfserr_serverfault;
608 out_negative:
609 printk(KERN_ERR "fh_update: %pd2 still negative!\n",
610 dentry);
611 return nfserr_serverfault;
612 }
613
614 /**
615 * fh_fill_pre_attrs - Fill in pre-op attributes
616 * @fhp: file handle to be updated
617 *
618 */
fh_fill_pre_attrs(struct svc_fh * fhp)619 void fh_fill_pre_attrs(struct svc_fh *fhp)
620 {
621 bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
622 struct inode *inode;
623 struct kstat stat;
624 __be32 err;
625
626 if (fhp->fh_no_wcc || fhp->fh_pre_saved)
627 return;
628
629 inode = d_inode(fhp->fh_dentry);
630 err = fh_getattr(fhp, &stat);
631 if (err) {
632 /* Grab the times from inode anyway */
633 stat.mtime = inode->i_mtime;
634 stat.ctime = inode->i_ctime;
635 stat.size = inode->i_size;
636 }
637 if (v4)
638 fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode);
639
640 fhp->fh_pre_mtime = stat.mtime;
641 fhp->fh_pre_ctime = stat.ctime;
642 fhp->fh_pre_size = stat.size;
643 fhp->fh_pre_saved = true;
644 }
645
646 /**
647 * fh_fill_post_attrs - Fill in post-op attributes
648 * @fhp: file handle to be updated
649 *
650 */
fh_fill_post_attrs(struct svc_fh * fhp)651 void fh_fill_post_attrs(struct svc_fh *fhp)
652 {
653 bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
654 struct inode *inode = d_inode(fhp->fh_dentry);
655 __be32 err;
656
657 if (fhp->fh_no_wcc)
658 return;
659
660 if (fhp->fh_post_saved)
661 printk("nfsd: inode locked twice during operation.\n");
662
663 err = fh_getattr(fhp, &fhp->fh_post_attr);
664 if (err) {
665 fhp->fh_post_saved = false;
666 fhp->fh_post_attr.ctime = inode->i_ctime;
667 } else
668 fhp->fh_post_saved = true;
669 if (v4)
670 fhp->fh_post_change =
671 nfsd4_change_attribute(&fhp->fh_post_attr, inode);
672 }
673
674 /*
675 * Release a file handle.
676 */
677 void
fh_put(struct svc_fh * fhp)678 fh_put(struct svc_fh *fhp)
679 {
680 struct dentry * dentry = fhp->fh_dentry;
681 struct svc_export * exp = fhp->fh_export;
682 if (dentry) {
683 fh_unlock(fhp);
684 fhp->fh_dentry = NULL;
685 dput(dentry);
686 fh_clear_pre_post_attrs(fhp);
687 }
688 fh_drop_write(fhp);
689 if (exp) {
690 exp_put(exp);
691 fhp->fh_export = NULL;
692 }
693 fhp->fh_no_wcc = false;
694 return;
695 }
696
697 /*
698 * Shorthand for dprintk()'s
699 */
SVCFH_fmt(struct svc_fh * fhp)700 char * SVCFH_fmt(struct svc_fh *fhp)
701 {
702 struct knfsd_fh *fh = &fhp->fh_handle;
703 static char buf[2+1+1+64*3+1];
704
705 if (fh->fh_size < 0 || fh->fh_size> 64)
706 return "bad-fh";
707 sprintf(buf, "%d: %*ph", fh->fh_size, fh->fh_size, fh->fh_raw);
708 return buf;
709 }
710
fsid_source(const struct svc_fh * fhp)711 enum fsid_source fsid_source(const struct svc_fh *fhp)
712 {
713 if (fhp->fh_handle.fh_version != 1)
714 return FSIDSOURCE_DEV;
715 switch(fhp->fh_handle.fh_fsid_type) {
716 case FSID_DEV:
717 case FSID_ENCODE_DEV:
718 case FSID_MAJOR_MINOR:
719 if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
720 return FSIDSOURCE_DEV;
721 break;
722 case FSID_NUM:
723 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
724 return FSIDSOURCE_FSID;
725 break;
726 default:
727 break;
728 }
729 /* either a UUID type filehandle, or the filehandle doesn't
730 * match the export.
731 */
732 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
733 return FSIDSOURCE_FSID;
734 if (fhp->fh_export->ex_uuid)
735 return FSIDSOURCE_UUID;
736 return FSIDSOURCE_DEV;
737 }
738