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v3.5.6
 
  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}
v4.17
  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
 18#define NFSDDBG_FACILITY		NFSDDBG_FH
 19
 20
 21/*
 22 * our acceptability function.
 23 * if NOSUBTREECHECK, accept anything
 24 * if not, require that we can walk up to exp->ex_dentry
 25 * doing some checks on the 'x' bits
 26 */
 27static int nfsd_acceptable(void *expv, struct dentry *dentry)
 28{
 29	struct svc_export *exp = expv;
 30	int rv;
 31	struct dentry *tdentry;
 32	struct dentry *parent;
 33
 34	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
 35		return 1;
 36
 37	tdentry = dget(dentry);
 38	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
 39		/* make sure parents give x permission to user */
 40		int err;
 41		parent = dget_parent(tdentry);
 42		err = inode_permission(d_inode(parent), MAY_EXEC);
 43		if (err < 0) {
 44			dput(parent);
 45			break;
 46		}
 47		dput(tdentry);
 48		tdentry = parent;
 49	}
 50	if (tdentry != exp->ex_path.dentry)
 51		dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
 52	rv = (tdentry == exp->ex_path.dentry);
 53	dput(tdentry);
 54	return rv;
 55}
 56
 57/* Type check. The correct error return for type mismatches does not seem to be
 58 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
 59 * comment in the NFSv3 spec says this is incorrect (implementation notes for
 60 * the write call).
 61 */
 62static inline __be32
 63nfsd_mode_check(struct svc_rqst *rqstp, struct dentry *dentry,
 64		umode_t requested)
 65{
 66	umode_t mode = d_inode(dentry)->i_mode & S_IFMT;
 67
 68	if (requested == 0) /* the caller doesn't care */
 69		return nfs_ok;
 70	if (mode == requested) {
 71		if (mode == S_IFDIR && !d_can_lookup(dentry)) {
 72			WARN_ON_ONCE(1);
 73			return nfserr_notdir;
 74		}
 75		return nfs_ok;
 76	}
 77	/*
 78	 * v4 has an error more specific than err_notdir which we should
 79	 * return in preference to err_notdir:
 80	 */
 81	if (rqstp->rq_vers == 4 && mode == S_IFLNK)
 82		return nfserr_symlink;
 83	if (requested == S_IFDIR)
 84		return nfserr_notdir;
 85	if (mode == S_IFDIR)
 86		return nfserr_isdir;
 87	return nfserr_inval;
 88}
 89
 90static bool nfsd_originating_port_ok(struct svc_rqst *rqstp, int flags)
 91{
 92	if (flags & NFSEXP_INSECURE_PORT)
 93		return true;
 94	/* We don't require gss requests to use low ports: */
 95	if (rqstp->rq_cred.cr_flavor >= RPC_AUTH_GSS)
 96		return true;
 97	return test_bit(RQ_SECURE, &rqstp->rq_flags);
 98}
 99
100static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
101					  struct svc_export *exp)
102{
103	int flags = nfsexp_flags(rqstp, exp);
104
105	/* Check if the request originated from a secure port. */
106	if (!nfsd_originating_port_ok(rqstp, flags)) {
107		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
108		dprintk("nfsd: request from insecure port %s!\n",
109		        svc_print_addr(rqstp, buf, sizeof(buf)));
 
110		return nfserr_perm;
111	}
112
113	/* Set user creds for this exportpoint */
114	return nfserrno(nfsd_setuser(rqstp, exp));
115}
116
117static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
118	struct dentry *dentry, struct svc_export *exp)
119{
120	if (!(exp->ex_flags & NFSEXP_V4ROOT))
121		return nfs_ok;
122	/*
123	 * v2/v3 clients have no need for the V4ROOT export--they use
124	 * the mount protocl instead; also, further V4ROOT checks may be
125	 * in v4-specific code, in which case v2/v3 clients could bypass
126	 * them.
127	 */
128	if (!nfsd_v4client(rqstp))
129		return nfserr_stale;
130	/*
131	 * We're exposing only the directories and symlinks that have to be
132	 * traversed on the way to real exports:
133	 */
134	if (unlikely(!d_is_dir(dentry) &&
135		     !d_is_symlink(dentry)))
136		return nfserr_stale;
137	/*
138	 * A pseudoroot export gives permission to access only one
139	 * single directory; the kernel has to make another upcall
140	 * before granting access to anything else under it:
141	 */
142	if (unlikely(dentry != exp->ex_path.dentry))
143		return nfserr_stale;
144	return nfs_ok;
145}
146
147/*
148 * Use the given filehandle to look up the corresponding export and
149 * dentry.  On success, the results are used to set fh_export and
150 * fh_dentry.
151 */
152static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
153{
154	struct knfsd_fh	*fh = &fhp->fh_handle;
155	struct fid *fid = NULL, sfid;
156	struct svc_export *exp;
157	struct dentry *dentry;
158	int fileid_type;
159	int data_left = fh->fh_size/4;
160	__be32 error;
161
162	error = nfserr_stale;
163	if (rqstp->rq_vers > 2)
164		error = nfserr_badhandle;
165	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
166		return nfserr_nofilehandle;
167
168	if (fh->fh_version == 1) {
169		int len;
170
171		if (--data_left < 0)
172			return error;
173		if (fh->fh_auth_type != 0)
174			return error;
175		len = key_len(fh->fh_fsid_type) / 4;
176		if (len == 0)
177			return error;
178		if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
179			/* deprecated, convert to type 3 */
180			len = key_len(FSID_ENCODE_DEV)/4;
181			fh->fh_fsid_type = FSID_ENCODE_DEV;
182			/*
183			 * struct knfsd_fh uses host-endian fields, which are
184			 * sometimes used to hold net-endian values. This
185			 * confuses sparse, so we must use __force here to
186			 * keep it from complaining.
187			 */
188			fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
189							ntohl((__force __be32)fh->fh_fsid[1])));
190			fh->fh_fsid[1] = fh->fh_fsid[2];
191		}
192		data_left -= len;
193		if (data_left < 0)
194			return error;
195		exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
196		fid = (struct fid *)(fh->fh_fsid + len);
197	} else {
198		__u32 tfh[2];
199		dev_t xdev;
200		ino_t xino;
201
202		if (fh->fh_size != NFS_FHSIZE)
203			return error;
204		/* assume old filehandle format */
205		xdev = old_decode_dev(fh->ofh_xdev);
206		xino = u32_to_ino_t(fh->ofh_xino);
207		mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
208		exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
209	}
210
211	error = nfserr_stale;
212	if (PTR_ERR(exp) == -ENOENT)
213		return error;
214
215	if (IS_ERR(exp))
216		return nfserrno(PTR_ERR(exp));
217
218	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
219		/* Elevate privileges so that the lack of 'r' or 'x'
220		 * permission on some parent directory will
221		 * not stop exportfs_decode_fh from being able
222		 * to reconnect a directory into the dentry cache.
223		 * The same problem can affect "SUBTREECHECK" exports,
224		 * but as nfsd_acceptable depends on correct
225		 * access control settings being in effect, we cannot
226		 * fix that case easily.
227		 */
228		struct cred *new = prepare_creds();
229		if (!new) {
230			error =  nfserrno(-ENOMEM);
231			goto out;
232		}
233		new->cap_effective =
234			cap_raise_nfsd_set(new->cap_effective,
235					   new->cap_permitted);
236		put_cred(override_creds(new));
237		put_cred(new);
238	} else {
239		error = nfsd_setuser_and_check_port(rqstp, exp);
240		if (error)
241			goto out;
242	}
243
244	/*
245	 * Look up the dentry using the NFS file handle.
246	 */
247	error = nfserr_stale;
248	if (rqstp->rq_vers > 2)
249		error = nfserr_badhandle;
250
251	if (fh->fh_version != 1) {
252		sfid.i32.ino = fh->ofh_ino;
253		sfid.i32.gen = fh->ofh_generation;
254		sfid.i32.parent_ino = fh->ofh_dirino;
255		fid = &sfid;
256		data_left = 3;
257		if (fh->ofh_dirino == 0)
258			fileid_type = FILEID_INO32_GEN;
259		else
260			fileid_type = FILEID_INO32_GEN_PARENT;
261	} else
262		fileid_type = fh->fh_fileid_type;
263
264	if (fileid_type == FILEID_ROOT)
265		dentry = dget(exp->ex_path.dentry);
266	else {
267		dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
268				data_left, fileid_type,
269				nfsd_acceptable, exp);
270	}
271	if (dentry == NULL)
272		goto out;
273	if (IS_ERR(dentry)) {
274		if (PTR_ERR(dentry) != -EINVAL)
275			error = nfserrno(PTR_ERR(dentry));
276		goto out;
277	}
278
279	if (d_is_dir(dentry) &&
280			(dentry->d_flags & DCACHE_DISCONNECTED)) {
281		printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
282				dentry);
283	}
284
285	fhp->fh_dentry = dentry;
286	fhp->fh_export = exp;
287	return 0;
288out:
289	exp_put(exp);
290	return error;
291}
292
293/**
294 * fh_verify - filehandle lookup and access checking
295 * @rqstp: pointer to current rpc request
296 * @fhp: filehandle to be verified
297 * @type: expected type of object pointed to by filehandle
298 * @access: type of access needed to object
299 *
300 * Look up a dentry from the on-the-wire filehandle, check the client's
301 * access to the export, and set the current task's credentials.
302 *
303 * Regardless of success or failure of fh_verify(), fh_put() should be
304 * called on @fhp when the caller is finished with the filehandle.
305 *
306 * fh_verify() may be called multiple times on a given filehandle, for
307 * example, when processing an NFSv4 compound.  The first call will look
308 * up a dentry using the on-the-wire filehandle.  Subsequent calls will
309 * skip the lookup and just perform the other checks and possibly change
310 * the current task's credentials.
311 *
312 * @type specifies the type of object expected using one of the S_IF*
313 * constants defined in include/linux/stat.h.  The caller may use zero
314 * to indicate that it doesn't care, or a negative integer to indicate
315 * that it expects something not of the given type.
316 *
317 * @access is formed from the NFSD_MAY_* constants defined in
318 * fs/nfsd/vfs.h.
319 */
320__be32
321fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
322{
323	struct svc_export *exp;
324	struct dentry	*dentry;
325	__be32		error;
326
327	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
328
329	if (!fhp->fh_dentry) {
330		error = nfsd_set_fh_dentry(rqstp, fhp);
331		if (error)
332			goto out;
333	}
334	dentry = fhp->fh_dentry;
335	exp = fhp->fh_export;
336	/*
337	 * We still have to do all these permission checks, even when
338	 * fh_dentry is already set:
339	 * 	- fh_verify may be called multiple times with different
340	 * 	  "access" arguments (e.g. nfsd_proc_create calls
341	 * 	  fh_verify(...,NFSD_MAY_EXEC) first, then later (in
342	 * 	  nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
343	 *	- in the NFSv4 case, the filehandle may have been filled
344	 *	  in by fh_compose, and given a dentry, but further
345	 *	  compound operations performed with that filehandle
346	 *	  still need permissions checks.  In the worst case, a
347	 *	  mountpoint crossing may have changed the export
348	 *	  options, and we may now need to use a different uid
349	 *	  (for example, if different id-squashing options are in
350	 *	  effect on the new filesystem).
351	 */
352	error = check_pseudo_root(rqstp, dentry, exp);
353	if (error)
354		goto out;
355
356	error = nfsd_setuser_and_check_port(rqstp, exp);
357	if (error)
358		goto out;
359
360	error = nfsd_mode_check(rqstp, dentry, type);
361	if (error)
362		goto out;
363
364	/*
365	 * pseudoflavor restrictions are not enforced on NLM,
366	 * which clients virtually always use auth_sys for,
367	 * even while using RPCSEC_GSS for NFS.
368	 */
369	if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
370		goto skip_pseudoflavor_check;
371	/*
372	 * Clients may expect to be able to use auth_sys during mount,
373	 * even if they use gss for everything else; see section 2.3.2
374	 * of rfc 2623.
375	 */
376	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
377			&& exp->ex_path.dentry == dentry)
378		goto skip_pseudoflavor_check;
379
380	error = check_nfsd_access(exp, rqstp);
381	if (error)
382		goto out;
383
384skip_pseudoflavor_check:
385	/* Finally, check access permissions. */
386	error = nfsd_permission(rqstp, exp, dentry, access);
387
388	if (error) {
389		dprintk("fh_verify: %pd2 permission failure, "
390			"acc=%x, error=%d\n",
391			dentry,
 
392			access, ntohl(error));
393	}
394out:
395	if (error == nfserr_stale)
396		nfsdstats.fh_stale++;
397	return error;
398}
399
400
401/*
402 * Compose a file handle for an NFS reply.
403 *
404 * Note that when first composed, the dentry may not yet have
405 * an inode.  In this case a call to fh_update should be made
406 * before the fh goes out on the wire ...
407 */
408static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
409		struct dentry *dentry)
410{
411	if (dentry != exp->ex_path.dentry) {
412		struct fid *fid = (struct fid *)
413			(fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
414		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
415		int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
416
417		fhp->fh_handle.fh_fileid_type =
418			exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
419		fhp->fh_handle.fh_size += maxsize * 4;
420	} else {
421		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
422	}
423}
424
425/*
426 * for composing old style file handles
427 */
428static inline void _fh_update_old(struct dentry *dentry,
429				  struct svc_export *exp,
430				  struct knfsd_fh *fh)
431{
432	fh->ofh_ino = ino_t_to_u32(d_inode(dentry)->i_ino);
433	fh->ofh_generation = d_inode(dentry)->i_generation;
434	if (d_is_dir(dentry) ||
435	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
436		fh->ofh_dirino = 0;
437}
438
439static bool is_root_export(struct svc_export *exp)
440{
441	return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
442}
443
444static struct super_block *exp_sb(struct svc_export *exp)
445{
446	return exp->ex_path.dentry->d_sb;
447}
448
449static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
450{
451	switch (fsid_type) {
452	case FSID_DEV:
453		if (!old_valid_dev(exp_sb(exp)->s_dev))
454			return 0;
455		/* FALL THROUGH */
456	case FSID_MAJOR_MINOR:
457	case FSID_ENCODE_DEV:
458		return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
459	case FSID_NUM:
460		return exp->ex_flags & NFSEXP_FSID;
461	case FSID_UUID8:
462	case FSID_UUID16:
463		if (!is_root_export(exp))
464			return 0;
465		/* fall through */
466	case FSID_UUID4_INUM:
467	case FSID_UUID16_INUM:
468		return exp->ex_uuid != NULL;
469	}
470	return 1;
471}
472
473
474static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
475{
476	u8 version;
477	u8 fsid_type;
478retry:
479	version = 1;
480	if (ref_fh && ref_fh->fh_export == exp) {
481		version = ref_fh->fh_handle.fh_version;
482		fsid_type = ref_fh->fh_handle.fh_fsid_type;
483
484		ref_fh = NULL;
485
486		switch (version) {
487		case 0xca:
488			fsid_type = FSID_DEV;
489			break;
490		case 1:
491			break;
492		default:
493			goto retry;
494		}
495
496		/*
497		 * As the fsid -> filesystem mapping was guided by
498		 * user-space, there is no guarantee that the filesystem
499		 * actually supports that fsid type. If it doesn't we
500		 * loop around again without ref_fh set.
501		 */
502		if (!fsid_type_ok_for_exp(fsid_type, exp))
503			goto retry;
504	} else if (exp->ex_flags & NFSEXP_FSID) {
505		fsid_type = FSID_NUM;
506	} else if (exp->ex_uuid) {
507		if (fhp->fh_maxsize >= 64) {
508			if (is_root_export(exp))
509				fsid_type = FSID_UUID16;
510			else
511				fsid_type = FSID_UUID16_INUM;
512		} else {
513			if (is_root_export(exp))
514				fsid_type = FSID_UUID8;
515			else
516				fsid_type = FSID_UUID4_INUM;
517		}
518	} else if (!old_valid_dev(exp_sb(exp)->s_dev))
519		/* for newer device numbers, we must use a newer fsid format */
520		fsid_type = FSID_ENCODE_DEV;
521	else
522		fsid_type = FSID_DEV;
523	fhp->fh_handle.fh_version = version;
524	if (version)
525		fhp->fh_handle.fh_fsid_type = fsid_type;
526}
527
528__be32
529fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
530	   struct svc_fh *ref_fh)
531{
532	/* ref_fh is a reference file handle.
533	 * if it is non-null and for the same filesystem, then we should compose
534	 * a filehandle which is of the same version, where possible.
535	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
536	 * Then create a 32byte filehandle using nfs_fhbase_old
537	 *
538	 */
539
540	struct inode * inode = d_inode(dentry);
 
 
541	dev_t ex_dev = exp_sb(exp)->s_dev;
542
543	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
544		MAJOR(ex_dev), MINOR(ex_dev),
545		(long) d_inode(exp->ex_path.dentry)->i_ino,
546		dentry,
547		(inode ? inode->i_ino : 0));
548
549	/* Choose filehandle version and fsid type based on
550	 * the reference filehandle (if it is in the same export)
551	 * or the export options.
552	 */
553	set_version_and_fsid_type(fhp, exp, ref_fh);
554
555	if (ref_fh == fhp)
556		fh_put(ref_fh);
557
558	if (fhp->fh_locked || fhp->fh_dentry) {
559		printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
560		       dentry);
561	}
562	if (fhp->fh_maxsize < NFS_FHSIZE)
563		printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
564		       fhp->fh_maxsize,
565		       dentry);
566
567	fhp->fh_dentry = dget(dentry); /* our internal copy */
568	fhp->fh_export = exp_get(exp);
 
569
570	if (fhp->fh_handle.fh_version == 0xca) {
571		/* old style filehandle please */
572		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
573		fhp->fh_handle.fh_size = NFS_FHSIZE;
574		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
575		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
576		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
577		fhp->fh_handle.ofh_xino =
578			ino_t_to_u32(d_inode(exp->ex_path.dentry)->i_ino);
579		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
580		if (inode)
581			_fh_update_old(dentry, exp, &fhp->fh_handle);
582	} else {
583		fhp->fh_handle.fh_size =
584			key_len(fhp->fh_handle.fh_fsid_type) + 4;
585		fhp->fh_handle.fh_auth_type = 0;
 
 
 
 
586
587		mk_fsid(fhp->fh_handle.fh_fsid_type,
588			fhp->fh_handle.fh_fsid,
589			ex_dev,
590			d_inode(exp->ex_path.dentry)->i_ino,
591			exp->ex_fsid, exp->ex_uuid);
592
593		if (inode)
594			_fh_update(fhp, exp, dentry);
595		if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
596			fh_put(fhp);
597			return nfserr_opnotsupp;
598		}
599	}
600
601	return 0;
602}
603
604/*
605 * Update file handle information after changing a dentry.
606 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
607 */
608__be32
609fh_update(struct svc_fh *fhp)
610{
611	struct dentry *dentry;
612
613	if (!fhp->fh_dentry)
614		goto out_bad;
615
616	dentry = fhp->fh_dentry;
617	if (d_really_is_negative(dentry))
618		goto out_negative;
619	if (fhp->fh_handle.fh_version != 1) {
620		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
621	} else {
622		if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
623			return 0;
624
625		_fh_update(fhp, fhp->fh_export, dentry);
626		if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
627			return nfserr_opnotsupp;
628	}
 
629	return 0;
 
630out_bad:
631	printk(KERN_ERR "fh_update: fh not verified!\n");
632	return nfserr_serverfault;
633out_negative:
634	printk(KERN_ERR "fh_update: %pd2 still negative!\n",
635		dentry);
636	return nfserr_serverfault;
637}
638
639/*
640 * Release a file handle.
641 */
642void
643fh_put(struct svc_fh *fhp)
644{
645	struct dentry * dentry = fhp->fh_dentry;
646	struct svc_export * exp = fhp->fh_export;
647	if (dentry) {
648		fh_unlock(fhp);
649		fhp->fh_dentry = NULL;
650		dput(dentry);
651		fh_clear_wcc(fhp);
 
 
 
652	}
653	fh_drop_write(fhp);
654	if (exp) {
655		exp_put(exp);
656		fhp->fh_export = NULL;
657	}
658	return;
659}
660
661/*
662 * Shorthand for dprintk()'s
663 */
664char * SVCFH_fmt(struct svc_fh *fhp)
665{
666	struct knfsd_fh *fh = &fhp->fh_handle;
667
668	static char buf[80];
669	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
670		fh->fh_size,
671		fh->fh_base.fh_pad[0],
672		fh->fh_base.fh_pad[1],
673		fh->fh_base.fh_pad[2],
674		fh->fh_base.fh_pad[3],
675		fh->fh_base.fh_pad[4],
676		fh->fh_base.fh_pad[5]);
677	return buf;
678}
679
680enum fsid_source fsid_source(struct svc_fh *fhp)
681{
682	if (fhp->fh_handle.fh_version != 1)
683		return FSIDSOURCE_DEV;
684	switch(fhp->fh_handle.fh_fsid_type) {
685	case FSID_DEV:
686	case FSID_ENCODE_DEV:
687	case FSID_MAJOR_MINOR:
688		if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
689			return FSIDSOURCE_DEV;
690		break;
691	case FSID_NUM:
692		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
693			return FSIDSOURCE_FSID;
694		break;
695	default:
696		break;
697	}
698	/* either a UUID type filehandle, or the filehandle doesn't
699	 * match the export.
700	 */
701	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
702		return FSIDSOURCE_FSID;
703	if (fhp->fh_export->ex_uuid)
704		return FSIDSOURCE_UUID;
705	return FSIDSOURCE_DEV;
706}