xref: /openbmc/linux/fs/nfsd/nfsfh.c (revision 455f9726)
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  */
26 static 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 %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  */
61 static inline __be32
62 nfsd_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 
83 static __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("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 
100 static 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(!S_ISDIR(dentry->d_inode->i_mode) &&
118 		     !S_ISLNK(dentry->d_inode->i_mode)))
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  */
135 static __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 			fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
166 			fh->fh_fsid[1] = fh->fh_fsid[2];
167 		}
168 		data_left -= len;
169 		if (data_left < 0)
170 			return error;
171 		exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
172 		fid = (struct fid *)(fh->fh_fsid + len);
173 	} else {
174 		__u32 tfh[2];
175 		dev_t xdev;
176 		ino_t xino;
177 
178 		if (fh->fh_size != NFS_FHSIZE)
179 			return error;
180 		/* assume old filehandle format */
181 		xdev = old_decode_dev(fh->ofh_xdev);
182 		xino = u32_to_ino_t(fh->ofh_xino);
183 		mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
184 		exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
185 	}
186 
187 	error = nfserr_stale;
188 	if (PTR_ERR(exp) == -ENOENT)
189 		return error;
190 
191 	if (IS_ERR(exp))
192 		return nfserrno(PTR_ERR(exp));
193 
194 	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
195 		/* Elevate privileges so that the lack of 'r' or 'x'
196 		 * permission on some parent directory will
197 		 * not stop exportfs_decode_fh from being able
198 		 * to reconnect a directory into the dentry cache.
199 		 * The same problem can affect "SUBTREECHECK" exports,
200 		 * but as nfsd_acceptable depends on correct
201 		 * access control settings being in effect, we cannot
202 		 * fix that case easily.
203 		 */
204 		struct cred *new = prepare_creds();
205 		if (!new)
206 			return nfserrno(-ENOMEM);
207 		new->cap_effective =
208 			cap_raise_nfsd_set(new->cap_effective,
209 					   new->cap_permitted);
210 		put_cred(override_creds(new));
211 		put_cred(new);
212 	} else {
213 		error = nfsd_setuser_and_check_port(rqstp, exp);
214 		if (error)
215 			goto out;
216 	}
217 
218 	/*
219 	 * Look up the dentry using the NFS file handle.
220 	 */
221 	error = nfserr_stale;
222 	if (rqstp->rq_vers > 2)
223 		error = nfserr_badhandle;
224 
225 	if (fh->fh_version != 1) {
226 		sfid.i32.ino = fh->ofh_ino;
227 		sfid.i32.gen = fh->ofh_generation;
228 		sfid.i32.parent_ino = fh->ofh_dirino;
229 		fid = &sfid;
230 		data_left = 3;
231 		if (fh->ofh_dirino == 0)
232 			fileid_type = FILEID_INO32_GEN;
233 		else
234 			fileid_type = FILEID_INO32_GEN_PARENT;
235 	} else
236 		fileid_type = fh->fh_fileid_type;
237 
238 	if (fileid_type == FILEID_ROOT)
239 		dentry = dget(exp->ex_path.dentry);
240 	else {
241 		dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
242 				data_left, fileid_type,
243 				nfsd_acceptable, exp);
244 	}
245 	if (dentry == NULL)
246 		goto out;
247 	if (IS_ERR(dentry)) {
248 		if (PTR_ERR(dentry) != -EINVAL)
249 			error = nfserrno(PTR_ERR(dentry));
250 		goto out;
251 	}
252 
253 	if (S_ISDIR(dentry->d_inode->i_mode) &&
254 			(dentry->d_flags & DCACHE_DISCONNECTED)) {
255 		printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
256 				dentry);
257 	}
258 
259 	fhp->fh_dentry = dentry;
260 	fhp->fh_export = exp;
261 	return 0;
262 out:
263 	exp_put(exp);
264 	return error;
265 }
266 
267 /**
268  * fh_verify - filehandle lookup and access checking
269  * @rqstp: pointer to current rpc request
270  * @fhp: filehandle to be verified
271  * @type: expected type of object pointed to by filehandle
272  * @access: type of access needed to object
273  *
274  * Look up a dentry from the on-the-wire filehandle, check the client's
275  * access to the export, and set the current task's credentials.
276  *
277  * Regardless of success or failure of fh_verify(), fh_put() should be
278  * called on @fhp when the caller is finished with the filehandle.
279  *
280  * fh_verify() may be called multiple times on a given filehandle, for
281  * example, when processing an NFSv4 compound.  The first call will look
282  * up a dentry using the on-the-wire filehandle.  Subsequent calls will
283  * skip the lookup and just perform the other checks and possibly change
284  * the current task's credentials.
285  *
286  * @type specifies the type of object expected using one of the S_IF*
287  * constants defined in include/linux/stat.h.  The caller may use zero
288  * to indicate that it doesn't care, or a negative integer to indicate
289  * that it expects something not of the given type.
290  *
291  * @access is formed from the NFSD_MAY_* constants defined in
292  * include/linux/nfsd/nfsd.h.
293  */
294 __be32
295 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
296 {
297 	struct svc_export *exp;
298 	struct dentry	*dentry;
299 	__be32		error;
300 
301 	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
302 
303 	if (!fhp->fh_dentry) {
304 		error = nfsd_set_fh_dentry(rqstp, fhp);
305 		if (error)
306 			goto out;
307 	}
308 	dentry = fhp->fh_dentry;
309 	exp = fhp->fh_export;
310 	/*
311 	 * We still have to do all these permission checks, even when
312 	 * fh_dentry is already set:
313 	 * 	- fh_verify may be called multiple times with different
314 	 * 	  "access" arguments (e.g. nfsd_proc_create calls
315 	 * 	  fh_verify(...,NFSD_MAY_EXEC) first, then later (in
316 	 * 	  nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
317 	 *	- in the NFSv4 case, the filehandle may have been filled
318 	 *	  in by fh_compose, and given a dentry, but further
319 	 *	  compound operations performed with that filehandle
320 	 *	  still need permissions checks.  In the worst case, a
321 	 *	  mountpoint crossing may have changed the export
322 	 *	  options, and we may now need to use a different uid
323 	 *	  (for example, if different id-squashing options are in
324 	 *	  effect on the new filesystem).
325 	 */
326 	error = check_pseudo_root(rqstp, dentry, exp);
327 	if (error)
328 		goto out;
329 
330 	error = nfsd_setuser_and_check_port(rqstp, exp);
331 	if (error)
332 		goto out;
333 
334 	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
335 	if (error)
336 		goto out;
337 
338 	/*
339 	 * pseudoflavor restrictions are not enforced on NLM,
340 	 * which clients virtually always use auth_sys for,
341 	 * even while using RPCSEC_GSS for NFS.
342 	 */
343 	if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
344 		goto skip_pseudoflavor_check;
345 	/*
346 	 * Clients may expect to be able to use auth_sys during mount,
347 	 * even if they use gss for everything else; see section 2.3.2
348 	 * of rfc 2623.
349 	 */
350 	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
351 			&& exp->ex_path.dentry == dentry)
352 		goto skip_pseudoflavor_check;
353 
354 	error = check_nfsd_access(exp, rqstp);
355 	if (error)
356 		goto out;
357 
358 skip_pseudoflavor_check:
359 	/* Finally, check access permissions. */
360 	error = nfsd_permission(rqstp, exp, dentry, access);
361 
362 	if (error) {
363 		dprintk("fh_verify: %pd2 permission failure, "
364 			"acc=%x, error=%d\n",
365 			dentry,
366 			access, ntohl(error));
367 	}
368 out:
369 	if (error == nfserr_stale)
370 		nfsdstats.fh_stale++;
371 	return error;
372 }
373 
374 
375 /*
376  * Compose a file handle for an NFS reply.
377  *
378  * Note that when first composed, the dentry may not yet have
379  * an inode.  In this case a call to fh_update should be made
380  * before the fh goes out on the wire ...
381  */
382 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
383 		struct dentry *dentry)
384 {
385 	if (dentry != exp->ex_path.dentry) {
386 		struct fid *fid = (struct fid *)
387 			(fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
388 		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
389 		int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
390 
391 		fhp->fh_handle.fh_fileid_type =
392 			exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
393 		fhp->fh_handle.fh_size += maxsize * 4;
394 	} else {
395 		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
396 	}
397 }
398 
399 /*
400  * for composing old style file handles
401  */
402 static inline void _fh_update_old(struct dentry *dentry,
403 				  struct svc_export *exp,
404 				  struct knfsd_fh *fh)
405 {
406 	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
407 	fh->ofh_generation = dentry->d_inode->i_generation;
408 	if (S_ISDIR(dentry->d_inode->i_mode) ||
409 	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
410 		fh->ofh_dirino = 0;
411 }
412 
413 static bool is_root_export(struct svc_export *exp)
414 {
415 	return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
416 }
417 
418 static struct super_block *exp_sb(struct svc_export *exp)
419 {
420 	return exp->ex_path.dentry->d_inode->i_sb;
421 }
422 
423 static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
424 {
425 	switch (fsid_type) {
426 	case FSID_DEV:
427 		if (!old_valid_dev(exp_sb(exp)->s_dev))
428 			return 0;
429 		/* FALL THROUGH */
430 	case FSID_MAJOR_MINOR:
431 	case FSID_ENCODE_DEV:
432 		return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
433 	case FSID_NUM:
434 		return exp->ex_flags & NFSEXP_FSID;
435 	case FSID_UUID8:
436 	case FSID_UUID16:
437 		if (!is_root_export(exp))
438 			return 0;
439 		/* fall through */
440 	case FSID_UUID4_INUM:
441 	case FSID_UUID16_INUM:
442 		return exp->ex_uuid != NULL;
443 	}
444 	return 1;
445 }
446 
447 
448 static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
449 {
450 	u8 version;
451 	u8 fsid_type;
452 retry:
453 	version = 1;
454 	if (ref_fh && ref_fh->fh_export == exp) {
455 		version = ref_fh->fh_handle.fh_version;
456 		fsid_type = ref_fh->fh_handle.fh_fsid_type;
457 
458 		ref_fh = NULL;
459 
460 		switch (version) {
461 		case 0xca:
462 			fsid_type = FSID_DEV;
463 			break;
464 		case 1:
465 			break;
466 		default:
467 			goto retry;
468 		}
469 
470 		/*
471 		 * As the fsid -> filesystem mapping was guided by
472 		 * user-space, there is no guarantee that the filesystem
473 		 * actually supports that fsid type. If it doesn't we
474 		 * loop around again without ref_fh set.
475 		 */
476 		if (!fsid_type_ok_for_exp(fsid_type, exp))
477 			goto retry;
478 	} else if (exp->ex_flags & NFSEXP_FSID) {
479 		fsid_type = FSID_NUM;
480 	} else if (exp->ex_uuid) {
481 		if (fhp->fh_maxsize >= 64) {
482 			if (is_root_export(exp))
483 				fsid_type = FSID_UUID16;
484 			else
485 				fsid_type = FSID_UUID16_INUM;
486 		} else {
487 			if (is_root_export(exp))
488 				fsid_type = FSID_UUID8;
489 			else
490 				fsid_type = FSID_UUID4_INUM;
491 		}
492 	} else if (!old_valid_dev(exp_sb(exp)->s_dev))
493 		/* for newer device numbers, we must use a newer fsid format */
494 		fsid_type = FSID_ENCODE_DEV;
495 	else
496 		fsid_type = FSID_DEV;
497 	fhp->fh_handle.fh_version = version;
498 	if (version)
499 		fhp->fh_handle.fh_fsid_type = fsid_type;
500 }
501 
502 __be32
503 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
504 	   struct svc_fh *ref_fh)
505 {
506 	/* ref_fh is a reference file handle.
507 	 * if it is non-null and for the same filesystem, then we should compose
508 	 * a filehandle which is of the same version, where possible.
509 	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
510 	 * Then create a 32byte filehandle using nfs_fhbase_old
511 	 *
512 	 */
513 
514 	struct inode * inode = dentry->d_inode;
515 	dev_t ex_dev = exp_sb(exp)->s_dev;
516 
517 	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
518 		MAJOR(ex_dev), MINOR(ex_dev),
519 		(long) exp->ex_path.dentry->d_inode->i_ino,
520 		dentry,
521 		(inode ? inode->i_ino : 0));
522 
523 	/* Choose filehandle version and fsid type based on
524 	 * the reference filehandle (if it is in the same export)
525 	 * or the export options.
526 	 */
527 	 set_version_and_fsid_type(fhp, exp, ref_fh);
528 
529 	if (ref_fh == fhp)
530 		fh_put(ref_fh);
531 
532 	if (fhp->fh_locked || fhp->fh_dentry) {
533 		printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
534 		       dentry);
535 	}
536 	if (fhp->fh_maxsize < NFS_FHSIZE)
537 		printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
538 		       fhp->fh_maxsize,
539 		       dentry);
540 
541 	fhp->fh_dentry = dget(dentry); /* our internal copy */
542 	fhp->fh_export = exp;
543 	cache_get(&exp->h);
544 
545 	if (fhp->fh_handle.fh_version == 0xca) {
546 		/* old style filehandle please */
547 		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
548 		fhp->fh_handle.fh_size = NFS_FHSIZE;
549 		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
550 		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
551 		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
552 		fhp->fh_handle.ofh_xino =
553 			ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
554 		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
555 		if (inode)
556 			_fh_update_old(dentry, exp, &fhp->fh_handle);
557 	} else {
558 		fhp->fh_handle.fh_size =
559 			key_len(fhp->fh_handle.fh_fsid_type) + 4;
560 		fhp->fh_handle.fh_auth_type = 0;
561 
562 		mk_fsid(fhp->fh_handle.fh_fsid_type,
563 			fhp->fh_handle.fh_fsid,
564 			ex_dev,
565 			exp->ex_path.dentry->d_inode->i_ino,
566 			exp->ex_fsid, exp->ex_uuid);
567 
568 		if (inode)
569 			_fh_update(fhp, exp, dentry);
570 		if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
571 			fh_put(fhp);
572 			return nfserr_opnotsupp;
573 		}
574 	}
575 
576 	return 0;
577 }
578 
579 /*
580  * Update file handle information after changing a dentry.
581  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
582  */
583 __be32
584 fh_update(struct svc_fh *fhp)
585 {
586 	struct dentry *dentry;
587 
588 	if (!fhp->fh_dentry)
589 		goto out_bad;
590 
591 	dentry = fhp->fh_dentry;
592 	if (!dentry->d_inode)
593 		goto out_negative;
594 	if (fhp->fh_handle.fh_version != 1) {
595 		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
596 	} else {
597 		if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
598 			return 0;
599 
600 		_fh_update(fhp, fhp->fh_export, dentry);
601 		if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
602 			return nfserr_opnotsupp;
603 	}
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  * Release a file handle.
616  */
617 void
618 fh_put(struct svc_fh *fhp)
619 {
620 	struct dentry * dentry = fhp->fh_dentry;
621 	struct svc_export * exp = fhp->fh_export;
622 	if (dentry) {
623 		fh_unlock(fhp);
624 		fhp->fh_dentry = NULL;
625 		dput(dentry);
626 #ifdef CONFIG_NFSD_V3
627 		fhp->fh_pre_saved = 0;
628 		fhp->fh_post_saved = 0;
629 #endif
630 	}
631 	fh_drop_write(fhp);
632 	if (exp) {
633 		exp_put(exp);
634 		fhp->fh_export = NULL;
635 	}
636 	return;
637 }
638 
639 /*
640  * Shorthand for dprintk()'s
641  */
642 char * SVCFH_fmt(struct svc_fh *fhp)
643 {
644 	struct knfsd_fh *fh = &fhp->fh_handle;
645 
646 	static char buf[80];
647 	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
648 		fh->fh_size,
649 		fh->fh_base.fh_pad[0],
650 		fh->fh_base.fh_pad[1],
651 		fh->fh_base.fh_pad[2],
652 		fh->fh_base.fh_pad[3],
653 		fh->fh_base.fh_pad[4],
654 		fh->fh_base.fh_pad[5]);
655 	return buf;
656 }
657 
658 enum fsid_source fsid_source(struct svc_fh *fhp)
659 {
660 	if (fhp->fh_handle.fh_version != 1)
661 		return FSIDSOURCE_DEV;
662 	switch(fhp->fh_handle.fh_fsid_type) {
663 	case FSID_DEV:
664 	case FSID_ENCODE_DEV:
665 	case FSID_MAJOR_MINOR:
666 		if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
667 			return FSIDSOURCE_DEV;
668 		break;
669 	case FSID_NUM:
670 		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
671 			return FSIDSOURCE_FSID;
672 		break;
673 	default:
674 		break;
675 	}
676 	/* either a UUID type filehandle, or the filehandle doesn't
677 	 * match the export.
678 	 */
679 	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
680 		return FSIDSOURCE_FSID;
681 	if (fhp->fh_export->ex_uuid)
682 		return FSIDSOURCE_UUID;
683 	return FSIDSOURCE_DEV;
684 }
685