xref: /linux/fs/nfsd/export.c (revision b0148a98ec5151fec82064d95f11eb9efbc628ea)
1 #define MSNFS	/* HACK HACK */
2 /*
3  * linux/fs/nfsd/export.c
4  *
5  * NFS exporting and validation.
6  *
7  * We maintain a list of clients, each of which has a list of
8  * exports. To export an fs to a given client, you first have
9  * to create the client entry with NFSCTL_ADDCLIENT, which
10  * creates a client control block and adds it to the hash
11  * table. Then, you call NFSCTL_EXPORT for each fs.
12  *
13  *
14  * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
15  */
16 
17 #include <linux/unistd.h>
18 #include <linux/slab.h>
19 #include <linux/sched.h>
20 #include <linux/stat.h>
21 #include <linux/in.h>
22 #include <linux/seq_file.h>
23 #include <linux/syscalls.h>
24 #include <linux/rwsem.h>
25 #include <linux/dcache.h>
26 #include <linux/namei.h>
27 #include <linux/mount.h>
28 #include <linux/hash.h>
29 #include <linux/module.h>
30 
31 #include <linux/sunrpc/svc.h>
32 #include <linux/nfsd/nfsd.h>
33 #include <linux/nfsd/nfsfh.h>
34 #include <linux/nfsd/syscall.h>
35 #include <linux/lockd/bind.h>
36 
37 #define NFSDDBG_FACILITY	NFSDDBG_EXPORT
38 
39 typedef struct auth_domain	svc_client;
40 typedef struct svc_export	svc_export;
41 
42 static void		exp_do_unexport(svc_export *unexp);
43 static int		exp_verify_string(char *cp, int max);
44 
45 /*
46  * We have two caches.
47  * One maps client+vfsmnt+dentry to export options - the export map
48  * The other maps client+filehandle-fragment to export options. - the expkey map
49  *
50  * The export options are actually stored in the first map, and the
51  * second map contains a reference to the entry in the first map.
52  */
53 
54 #define	EXPKEY_HASHBITS		8
55 #define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
56 #define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
57 static struct cache_head *expkey_table[EXPKEY_HASHMAX];
58 
59 static void expkey_put(struct kref *ref)
60 {
61 	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
62 
63 	if (test_bit(CACHE_VALID, &key->h.flags) &&
64 	    !test_bit(CACHE_NEGATIVE, &key->h.flags)) {
65 		dput(key->ek_dentry);
66 		mntput(key->ek_mnt);
67 	}
68 	auth_domain_put(key->ek_client);
69 	kfree(key);
70 }
71 
72 static void expkey_request(struct cache_detail *cd,
73 			   struct cache_head *h,
74 			   char **bpp, int *blen)
75 {
76 	/* client fsidtype \xfsid */
77 	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
78 	char type[5];
79 
80 	qword_add(bpp, blen, ek->ek_client->name);
81 	snprintf(type, 5, "%d", ek->ek_fsidtype);
82 	qword_add(bpp, blen, type);
83 	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
84 	(*bpp)[-1] = '\n';
85 }
86 
87 static struct svc_expkey *svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old);
88 static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *);
89 static struct cache_detail svc_expkey_cache;
90 
91 static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
92 {
93 	/* client fsidtype fsid [path] */
94 	char *buf;
95 	int len;
96 	struct auth_domain *dom = NULL;
97 	int err;
98 	int fsidtype;
99 	char *ep;
100 	struct svc_expkey key;
101 	struct svc_expkey *ek;
102 
103 	if (mesg[mlen-1] != '\n')
104 		return -EINVAL;
105 	mesg[mlen-1] = 0;
106 
107 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
108 	err = -ENOMEM;
109 	if (!buf) goto out;
110 
111 	err = -EINVAL;
112 	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
113 		goto out;
114 
115 	err = -ENOENT;
116 	dom = auth_domain_find(buf);
117 	if (!dom)
118 		goto out;
119 	dprintk("found domain %s\n", buf);
120 
121 	err = -EINVAL;
122 	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
123 		goto out;
124 	fsidtype = simple_strtoul(buf, &ep, 10);
125 	if (*ep)
126 		goto out;
127 	dprintk("found fsidtype %d\n", fsidtype);
128 	if (key_len(fsidtype)==0) /* invalid type */
129 		goto out;
130 	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
131 		goto out;
132 	dprintk("found fsid length %d\n", len);
133 	if (len != key_len(fsidtype))
134 		goto out;
135 
136 	/* OK, we seem to have a valid key */
137 	key.h.flags = 0;
138 	key.h.expiry_time = get_expiry(&mesg);
139 	if (key.h.expiry_time == 0)
140 		goto out;
141 
142 	key.ek_client = dom;
143 	key.ek_fsidtype = fsidtype;
144 	memcpy(key.ek_fsid, buf, len);
145 
146 	ek = svc_expkey_lookup(&key);
147 	err = -ENOMEM;
148 	if (!ek)
149 		goto out;
150 
151 	/* now we want a pathname, or empty meaning NEGATIVE  */
152 	err = -EINVAL;
153 	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) < 0)
154 		goto out;
155 	dprintk("Path seems to be <%s>\n", buf);
156 	err = 0;
157 	if (len == 0) {
158 		set_bit(CACHE_NEGATIVE, &key.h.flags);
159 		ek = svc_expkey_update(&key, ek);
160 		if (ek)
161 			cache_put(&ek->h, &svc_expkey_cache);
162 		else err = -ENOMEM;
163 	} else {
164 		struct nameidata nd;
165 		err = path_lookup(buf, 0, &nd);
166 		if (err)
167 			goto out;
168 
169 		dprintk("Found the path %s\n", buf);
170 		key.ek_mnt = nd.mnt;
171 		key.ek_dentry = nd.dentry;
172 
173 		ek = svc_expkey_update(&key, ek);
174 		if (ek)
175 			cache_put(&ek->h, &svc_expkey_cache);
176 		else
177 			err = -ENOMEM;
178 		path_release(&nd);
179 	}
180 	cache_flush();
181  out:
182 	if (dom)
183 		auth_domain_put(dom);
184 	kfree(buf);
185 	return err;
186 }
187 
188 static int expkey_show(struct seq_file *m,
189 		       struct cache_detail *cd,
190 		       struct cache_head *h)
191 {
192 	struct svc_expkey *ek ;
193 
194 	if (h ==NULL) {
195 		seq_puts(m, "#domain fsidtype fsid [path]\n");
196 		return 0;
197 	}
198 	ek = container_of(h, struct svc_expkey, h);
199 	seq_printf(m, "%s %d 0x%08x", ek->ek_client->name,
200 		   ek->ek_fsidtype, ek->ek_fsid[0]);
201 	if (ek->ek_fsidtype != 1)
202 		seq_printf(m, "%08x", ek->ek_fsid[1]);
203 	if (ek->ek_fsidtype == 2)
204 		seq_printf(m, "%08x", ek->ek_fsid[2]);
205 	if (test_bit(CACHE_VALID, &h->flags) &&
206 	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
207 		seq_printf(m, " ");
208 		seq_path(m, ek->ek_mnt, ek->ek_dentry, "\\ \t\n");
209 	}
210 	seq_printf(m, "\n");
211 	return 0;
212 }
213 
214 static inline int expkey_match (struct cache_head *a, struct cache_head *b)
215 {
216 	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
217 	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
218 
219 	if (orig->ek_fsidtype != new->ek_fsidtype ||
220 	    orig->ek_client != new->ek_client ||
221 	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
222 		return 0;
223 	return 1;
224 }
225 
226 static inline void expkey_init(struct cache_head *cnew,
227 				   struct cache_head *citem)
228 {
229 	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
230 	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
231 
232 	kref_get(&item->ek_client->ref);
233 	new->ek_client = item->ek_client;
234 	new->ek_fsidtype = item->ek_fsidtype;
235 	new->ek_fsid[0] = item->ek_fsid[0];
236 	new->ek_fsid[1] = item->ek_fsid[1];
237 	new->ek_fsid[2] = item->ek_fsid[2];
238 }
239 
240 static inline void expkey_update(struct cache_head *cnew,
241 				   struct cache_head *citem)
242 {
243 	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
244 	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
245 
246 	new->ek_mnt = mntget(item->ek_mnt);
247 	new->ek_dentry = dget(item->ek_dentry);
248 }
249 
250 static struct cache_head *expkey_alloc(void)
251 {
252 	struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
253 	if (i)
254 		return &i->h;
255 	else
256 		return NULL;
257 }
258 
259 static struct cache_detail svc_expkey_cache = {
260 	.owner		= THIS_MODULE,
261 	.hash_size	= EXPKEY_HASHMAX,
262 	.hash_table	= expkey_table,
263 	.name		= "nfsd.fh",
264 	.cache_put	= expkey_put,
265 	.cache_request	= expkey_request,
266 	.cache_parse	= expkey_parse,
267 	.cache_show	= expkey_show,
268 	.match		= expkey_match,
269 	.init		= expkey_init,
270 	.update       	= expkey_update,
271 	.alloc		= expkey_alloc,
272 };
273 
274 static struct svc_expkey *
275 svc_expkey_lookup(struct svc_expkey *item)
276 {
277 	struct cache_head *ch;
278 	int hash = item->ek_fsidtype;
279 	char * cp = (char*)item->ek_fsid;
280 	int len = key_len(item->ek_fsidtype);
281 
282 	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
283 	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
284 	hash &= EXPKEY_HASHMASK;
285 
286 	ch = sunrpc_cache_lookup(&svc_expkey_cache, &item->h,
287 				 hash);
288 	if (ch)
289 		return container_of(ch, struct svc_expkey, h);
290 	else
291 		return NULL;
292 }
293 
294 static struct svc_expkey *
295 svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old)
296 {
297 	struct cache_head *ch;
298 	int hash = new->ek_fsidtype;
299 	char * cp = (char*)new->ek_fsid;
300 	int len = key_len(new->ek_fsidtype);
301 
302 	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
303 	hash ^= hash_ptr(new->ek_client, EXPKEY_HASHBITS);
304 	hash &= EXPKEY_HASHMASK;
305 
306 	ch = sunrpc_cache_update(&svc_expkey_cache, &new->h,
307 				 &old->h, hash);
308 	if (ch)
309 		return container_of(ch, struct svc_expkey, h);
310 	else
311 		return NULL;
312 }
313 
314 
315 #define	EXPORT_HASHBITS		8
316 #define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
317 #define	EXPORT_HASHMASK		(EXPORT_HASHMAX -1)
318 
319 static struct cache_head *export_table[EXPORT_HASHMAX];
320 
321 static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
322 {
323 	int i;
324 
325 	for (i = 0; i < fsloc->locations_count; i++) {
326 		kfree(fsloc->locations[i].path);
327 		kfree(fsloc->locations[i].hosts);
328 	}
329 	kfree(fsloc->locations);
330 }
331 
332 static void svc_export_put(struct kref *ref)
333 {
334 	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
335 	dput(exp->ex_dentry);
336 	mntput(exp->ex_mnt);
337 	auth_domain_put(exp->ex_client);
338 	kfree(exp->ex_path);
339 	nfsd4_fslocs_free(&exp->ex_fslocs);
340 	kfree(exp);
341 }
342 
343 static void svc_export_request(struct cache_detail *cd,
344 			       struct cache_head *h,
345 			       char **bpp, int *blen)
346 {
347 	/*  client path */
348 	struct svc_export *exp = container_of(h, struct svc_export, h);
349 	char *pth;
350 
351 	qword_add(bpp, blen, exp->ex_client->name);
352 	pth = d_path(exp->ex_dentry, exp->ex_mnt, *bpp, *blen);
353 	if (IS_ERR(pth)) {
354 		/* is this correct? */
355 		(*bpp)[0] = '\n';
356 		return;
357 	}
358 	qword_add(bpp, blen, pth);
359 	(*bpp)[-1] = '\n';
360 }
361 
362 static struct svc_export *svc_export_update(struct svc_export *new,
363 					    struct svc_export *old);
364 static struct svc_export *svc_export_lookup(struct svc_export *);
365 
366 static int check_export(struct inode *inode, int flags)
367 {
368 
369 	/* We currently export only dirs and regular files.
370 	 * This is what umountd does.
371 	 */
372 	if (!S_ISDIR(inode->i_mode) &&
373 	    !S_ISREG(inode->i_mode))
374 		return -ENOTDIR;
375 
376 	/* There are two requirements on a filesystem to be exportable.
377 	 * 1:  We must be able to identify the filesystem from a number.
378 	 *       either a device number (so FS_REQUIRES_DEV needed)
379 	 *       or an FSID number (so NFSEXP_FSID needed).
380 	 * 2:  We must be able to find an inode from a filehandle.
381 	 *       This means that s_export_op must be set.
382 	 */
383 	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
384 	    !(flags & NFSEXP_FSID)) {
385 		dprintk("exp_export: export of non-dev fs without fsid\n");
386 		return -EINVAL;
387 	}
388 	if (!inode->i_sb->s_export_op) {
389 		dprintk("exp_export: export of invalid fs type.\n");
390 		return -EINVAL;
391 	}
392 
393 	/* Ok, we can export it */;
394 	if (!inode->i_sb->s_export_op->find_exported_dentry)
395 		inode->i_sb->s_export_op->find_exported_dentry =
396 			find_exported_dentry;
397 	return 0;
398 
399 }
400 
401 #ifdef CONFIG_NFSD_V4
402 
403 static int
404 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
405 {
406 	int len;
407 	int migrated, i, err;
408 
409 	len = qword_get(mesg, buf, PAGE_SIZE);
410 	if (len != 5 || memcmp(buf, "fsloc", 5))
411 		return 0;
412 
413 	/* listsize */
414 	err = get_int(mesg, &fsloc->locations_count);
415 	if (err)
416 		return err;
417 	if (fsloc->locations_count > MAX_FS_LOCATIONS)
418 		return -EINVAL;
419 	if (fsloc->locations_count == 0)
420 		return 0;
421 
422 	fsloc->locations = kzalloc(fsloc->locations_count
423 			* sizeof(struct nfsd4_fs_location), GFP_KERNEL);
424 	if (!fsloc->locations)
425 		return -ENOMEM;
426 	for (i=0; i < fsloc->locations_count; i++) {
427 		/* colon separated host list */
428 		err = -EINVAL;
429 		len = qword_get(mesg, buf, PAGE_SIZE);
430 		if (len <= 0)
431 			goto out_free_all;
432 		err = -ENOMEM;
433 		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
434 		if (!fsloc->locations[i].hosts)
435 			goto out_free_all;
436 		err = -EINVAL;
437 		/* slash separated path component list */
438 		len = qword_get(mesg, buf, PAGE_SIZE);
439 		if (len <= 0)
440 			goto out_free_all;
441 		err = -ENOMEM;
442 		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
443 		if (!fsloc->locations[i].path)
444 			goto out_free_all;
445 	}
446 	/* migrated */
447 	err = get_int(mesg, &migrated);
448 	if (err)
449 		goto out_free_all;
450 	err = -EINVAL;
451 	if (migrated < 0 || migrated > 1)
452 		goto out_free_all;
453 	fsloc->migrated = migrated;
454 	return 0;
455 out_free_all:
456 	nfsd4_fslocs_free(fsloc);
457 	return err;
458 }
459 
460 #else /* CONFIG_NFSD_V4 */
461 static inline int fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc) { return 0; }
462 #endif
463 
464 static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
465 {
466 	/* client path expiry [flags anonuid anongid fsid] */
467 	char *buf;
468 	int len;
469 	int err;
470 	struct auth_domain *dom = NULL;
471 	struct nameidata nd;
472 	struct svc_export exp, *expp;
473 	int an_int;
474 
475 	nd.dentry = NULL;
476 	exp.ex_path = NULL;
477 
478 	if (mesg[mlen-1] != '\n')
479 		return -EINVAL;
480 	mesg[mlen-1] = 0;
481 
482 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
483 	err = -ENOMEM;
484 	if (!buf) goto out;
485 
486 	/* client */
487 	len = qword_get(&mesg, buf, PAGE_SIZE);
488 	err = -EINVAL;
489 	if (len <= 0) goto out;
490 
491 	err = -ENOENT;
492 	dom = auth_domain_find(buf);
493 	if (!dom)
494 		goto out;
495 
496 	/* path */
497 	err = -EINVAL;
498 	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
499 		goto out;
500 	err = path_lookup(buf, 0, &nd);
501 	if (err) goto out_no_path;
502 
503 	exp.h.flags = 0;
504 	exp.ex_client = dom;
505 	exp.ex_mnt = nd.mnt;
506 	exp.ex_dentry = nd.dentry;
507 	exp.ex_path = kstrdup(buf, GFP_KERNEL);
508 	err = -ENOMEM;
509 	if (!exp.ex_path)
510 		goto out;
511 
512 	/* expiry */
513 	err = -EINVAL;
514 	exp.h.expiry_time = get_expiry(&mesg);
515 	if (exp.h.expiry_time == 0)
516 		goto out;
517 
518 	/* fs locations */
519 	exp.ex_fslocs.locations = NULL;
520 	exp.ex_fslocs.locations_count = 0;
521 	exp.ex_fslocs.migrated = 0;
522 
523 	/* flags */
524 	err = get_int(&mesg, &an_int);
525 	if (err == -ENOENT)
526 		set_bit(CACHE_NEGATIVE, &exp.h.flags);
527 	else {
528 		if (err || an_int < 0) goto out;
529 		exp.ex_flags= an_int;
530 
531 		/* anon uid */
532 		err = get_int(&mesg, &an_int);
533 		if (err) goto out;
534 		exp.ex_anon_uid= an_int;
535 
536 		/* anon gid */
537 		err = get_int(&mesg, &an_int);
538 		if (err) goto out;
539 		exp.ex_anon_gid= an_int;
540 
541 		/* fsid */
542 		err = get_int(&mesg, &an_int);
543 		if (err) goto out;
544 		exp.ex_fsid = an_int;
545 
546 		err = check_export(nd.dentry->d_inode, exp.ex_flags);
547 		if (err) goto out;
548 
549 		err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
550 		if (err)
551 			goto out;
552 	}
553 
554 	expp = svc_export_lookup(&exp);
555 	if (expp)
556 		expp = svc_export_update(&exp, expp);
557 	else
558 		err = -ENOMEM;
559 	cache_flush();
560 	if (expp == NULL)
561 		err = -ENOMEM;
562 	else
563 		exp_put(expp);
564  out:
565  	kfree(exp.ex_path);
566 	if (nd.dentry)
567 		path_release(&nd);
568  out_no_path:
569 	if (dom)
570 		auth_domain_put(dom);
571 	kfree(buf);
572 	return err;
573 }
574 
575 static void exp_flags(struct seq_file *m, int flag, int fsid,
576 		uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fslocs);
577 
578 static int svc_export_show(struct seq_file *m,
579 			   struct cache_detail *cd,
580 			   struct cache_head *h)
581 {
582 	struct svc_export *exp ;
583 
584 	if (h ==NULL) {
585 		seq_puts(m, "#path domain(flags)\n");
586 		return 0;
587 	}
588 	exp = container_of(h, struct svc_export, h);
589 	seq_path(m, exp->ex_mnt, exp->ex_dentry, " \t\n\\");
590 	seq_putc(m, '\t');
591 	seq_escape(m, exp->ex_client->name, " \t\n\\");
592 	seq_putc(m, '(');
593 	if (test_bit(CACHE_VALID, &h->flags) &&
594 	    !test_bit(CACHE_NEGATIVE, &h->flags))
595 		exp_flags(m, exp->ex_flags, exp->ex_fsid,
596 			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
597 	seq_puts(m, ")\n");
598 	return 0;
599 }
600 static int svc_export_match(struct cache_head *a, struct cache_head *b)
601 {
602 	struct svc_export *orig = container_of(a, struct svc_export, h);
603 	struct svc_export *new = container_of(b, struct svc_export, h);
604 	return orig->ex_client == new->ex_client &&
605 		orig->ex_dentry == new->ex_dentry &&
606 		orig->ex_mnt == new->ex_mnt;
607 }
608 
609 static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
610 {
611 	struct svc_export *new = container_of(cnew, struct svc_export, h);
612 	struct svc_export *item = container_of(citem, struct svc_export, h);
613 
614 	kref_get(&item->ex_client->ref);
615 	new->ex_client = item->ex_client;
616 	new->ex_dentry = dget(item->ex_dentry);
617 	new->ex_mnt = mntget(item->ex_mnt);
618 	new->ex_path = NULL;
619 	new->ex_fslocs.locations = NULL;
620 	new->ex_fslocs.locations_count = 0;
621 	new->ex_fslocs.migrated = 0;
622 }
623 
624 static void export_update(struct cache_head *cnew, struct cache_head *citem)
625 {
626 	struct svc_export *new = container_of(cnew, struct svc_export, h);
627 	struct svc_export *item = container_of(citem, struct svc_export, h);
628 
629 	new->ex_flags = item->ex_flags;
630 	new->ex_anon_uid = item->ex_anon_uid;
631 	new->ex_anon_gid = item->ex_anon_gid;
632 	new->ex_fsid = item->ex_fsid;
633 	new->ex_path = item->ex_path;
634 	item->ex_path = NULL;
635 	new->ex_fslocs.locations = item->ex_fslocs.locations;
636 	item->ex_fslocs.locations = NULL;
637 	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
638 	item->ex_fslocs.locations_count = 0;
639 	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
640 	item->ex_fslocs.migrated = 0;
641 }
642 
643 static struct cache_head *svc_export_alloc(void)
644 {
645 	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
646 	if (i)
647 		return &i->h;
648 	else
649 		return NULL;
650 }
651 
652 struct cache_detail svc_export_cache = {
653 	.owner		= THIS_MODULE,
654 	.hash_size	= EXPORT_HASHMAX,
655 	.hash_table	= export_table,
656 	.name		= "nfsd.export",
657 	.cache_put	= svc_export_put,
658 	.cache_request	= svc_export_request,
659 	.cache_parse	= svc_export_parse,
660 	.cache_show	= svc_export_show,
661 	.match		= svc_export_match,
662 	.init		= svc_export_init,
663 	.update		= export_update,
664 	.alloc		= svc_export_alloc,
665 };
666 
667 static struct svc_export *
668 svc_export_lookup(struct svc_export *exp)
669 {
670 	struct cache_head *ch;
671 	int hash;
672 	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
673 	hash ^= hash_ptr(exp->ex_dentry, EXPORT_HASHBITS);
674 	hash ^= hash_ptr(exp->ex_mnt, EXPORT_HASHBITS);
675 
676 	ch = sunrpc_cache_lookup(&svc_export_cache, &exp->h,
677 				 hash);
678 	if (ch)
679 		return container_of(ch, struct svc_export, h);
680 	else
681 		return NULL;
682 }
683 
684 static struct svc_export *
685 svc_export_update(struct svc_export *new, struct svc_export *old)
686 {
687 	struct cache_head *ch;
688 	int hash;
689 	hash = hash_ptr(old->ex_client, EXPORT_HASHBITS);
690 	hash ^= hash_ptr(old->ex_dentry, EXPORT_HASHBITS);
691 	hash ^= hash_ptr(old->ex_mnt, EXPORT_HASHBITS);
692 
693 	ch = sunrpc_cache_update(&svc_export_cache, &new->h,
694 				 &old->h,
695 				 hash);
696 	if (ch)
697 		return container_of(ch, struct svc_export, h);
698 	else
699 		return NULL;
700 }
701 
702 
703 static struct svc_expkey *
704 exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
705 {
706 	struct svc_expkey key, *ek;
707 	int err;
708 
709 	if (!clp)
710 		return NULL;
711 
712 	key.ek_client = clp;
713 	key.ek_fsidtype = fsid_type;
714 	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
715 
716 	ek = svc_expkey_lookup(&key);
717 	if (ek != NULL)
718 		if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
719 			ek = ERR_PTR(err);
720 	return ek;
721 }
722 
723 static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
724 		       struct svc_export *exp)
725 {
726 	struct svc_expkey key, *ek;
727 
728 	key.ek_client = clp;
729 	key.ek_fsidtype = fsid_type;
730 	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
731 	key.ek_mnt = exp->ex_mnt;
732 	key.ek_dentry = exp->ex_dentry;
733 	key.h.expiry_time = NEVER;
734 	key.h.flags = 0;
735 
736 	ek = svc_expkey_lookup(&key);
737 	if (ek)
738 		ek = svc_expkey_update(&key,ek);
739 	if (ek) {
740 		cache_put(&ek->h, &svc_expkey_cache);
741 		return 0;
742 	}
743 	return -ENOMEM;
744 }
745 
746 /*
747  * Find the client's export entry matching xdev/xino.
748  */
749 static inline struct svc_expkey *
750 exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
751 {
752 	u32 fsidv[3];
753 
754 	if (old_valid_dev(dev)) {
755 		mk_fsid_v0(fsidv, dev, ino);
756 		return exp_find_key(clp, 0, fsidv, NULL);
757 	}
758 	mk_fsid_v3(fsidv, dev, ino);
759 	return exp_find_key(clp, 3, fsidv, NULL);
760 }
761 
762 /*
763  * Find the client's export entry matching fsid
764  */
765 static inline struct svc_expkey *
766 exp_get_fsid_key(svc_client *clp, int fsid)
767 {
768 	u32 fsidv[2];
769 
770 	mk_fsid_v1(fsidv, fsid);
771 
772 	return exp_find_key(clp, 1, fsidv, NULL);
773 }
774 
775 svc_export *
776 exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
777 		struct cache_req *reqp)
778 {
779 	struct svc_export *exp, key;
780 
781 	if (!clp)
782 		return NULL;
783 
784 	key.ex_client = clp;
785 	key.ex_mnt = mnt;
786 	key.ex_dentry = dentry;
787 
788 	exp = svc_export_lookup(&key);
789 	if (exp != NULL)  {
790 		int err;
791 
792 		err = cache_check(&svc_export_cache, &exp->h, reqp);
793 		switch (err) {
794 		case 0: break;
795 		case -EAGAIN:
796 		case -ETIMEDOUT:
797 			exp = ERR_PTR(err);
798 			break;
799 		default:
800 			exp = NULL;
801 		}
802 	}
803 
804 	return exp;
805 }
806 
807 /*
808  * Find the export entry for a given dentry.
809  */
810 struct svc_export *
811 exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
812 	   struct cache_req *reqp)
813 {
814 	svc_export *exp;
815 
816 	dget(dentry);
817 	exp = exp_get_by_name(clp, mnt, dentry, reqp);
818 
819 	while (exp == NULL && !IS_ROOT(dentry)) {
820 		struct dentry *parent;
821 
822 		parent = dget_parent(dentry);
823 		dput(dentry);
824 		dentry = parent;
825 		exp = exp_get_by_name(clp, mnt, dentry, reqp);
826 	}
827 	dput(dentry);
828 	return exp;
829 }
830 
831 /*
832  * Hashtable locking. Write locks are placed only by user processes
833  * wanting to modify export information.
834  * Write locking only done in this file.  Read locking
835  * needed externally.
836  */
837 
838 static DECLARE_RWSEM(hash_sem);
839 
840 void
841 exp_readlock(void)
842 {
843 	down_read(&hash_sem);
844 }
845 
846 static inline void
847 exp_writelock(void)
848 {
849 	down_write(&hash_sem);
850 }
851 
852 void
853 exp_readunlock(void)
854 {
855 	up_read(&hash_sem);
856 }
857 
858 static inline void
859 exp_writeunlock(void)
860 {
861 	up_write(&hash_sem);
862 }
863 
864 static void exp_fsid_unhash(struct svc_export *exp)
865 {
866 	struct svc_expkey *ek;
867 
868 	if ((exp->ex_flags & NFSEXP_FSID) == 0)
869 		return;
870 
871 	ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
872 	if (ek && !IS_ERR(ek)) {
873 		ek->h.expiry_time = get_seconds()-1;
874 		cache_put(&ek->h, &svc_expkey_cache);
875 	}
876 	svc_expkey_cache.nextcheck = get_seconds();
877 }
878 
879 static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
880 {
881 	u32 fsid[2];
882 
883 	if ((exp->ex_flags & NFSEXP_FSID) == 0)
884 		return 0;
885 
886 	mk_fsid_v1(fsid, exp->ex_fsid);
887 	return exp_set_key(clp, 1, fsid, exp);
888 }
889 
890 static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
891 {
892 	u32 fsid[2];
893 	struct inode *inode = exp->ex_dentry->d_inode;
894 	dev_t dev = inode->i_sb->s_dev;
895 
896 	if (old_valid_dev(dev)) {
897 		mk_fsid_v0(fsid, dev, inode->i_ino);
898 		return exp_set_key(clp, 0, fsid, exp);
899 	}
900 	mk_fsid_v3(fsid, dev, inode->i_ino);
901 	return exp_set_key(clp, 3, fsid, exp);
902 }
903 
904 static void exp_unhash(struct svc_export *exp)
905 {
906 	struct svc_expkey *ek;
907 	struct inode *inode = exp->ex_dentry->d_inode;
908 
909 	ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
910 	if (ek && !IS_ERR(ek)) {
911 		ek->h.expiry_time = get_seconds()-1;
912 		cache_put(&ek->h, &svc_expkey_cache);
913 	}
914 	svc_expkey_cache.nextcheck = get_seconds();
915 }
916 
917 /*
918  * Export a file system.
919  */
920 int
921 exp_export(struct nfsctl_export *nxp)
922 {
923 	svc_client	*clp;
924 	struct svc_export	*exp = NULL;
925 	struct svc_export	new;
926 	struct svc_expkey	*fsid_key = NULL;
927 	struct nameidata nd;
928 	int		err;
929 
930 	/* Consistency check */
931 	err = -EINVAL;
932 	if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
933 	    !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
934 		goto out;
935 
936 	dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
937 			nxp->ex_client, nxp->ex_path,
938 			(unsigned)nxp->ex_dev, (long)nxp->ex_ino,
939 			nxp->ex_flags);
940 
941 	/* Try to lock the export table for update */
942 	exp_writelock();
943 
944 	/* Look up client info */
945 	if (!(clp = auth_domain_find(nxp->ex_client)))
946 		goto out_unlock;
947 
948 
949 	/* Look up the dentry */
950 	err = path_lookup(nxp->ex_path, 0, &nd);
951 	if (err)
952 		goto out_unlock;
953 	err = -EINVAL;
954 
955 	exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
956 
957 	memset(&new, 0, sizeof(new));
958 
959 	/* must make sure there won't be an ex_fsid clash */
960 	if ((nxp->ex_flags & NFSEXP_FSID) &&
961 	    (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
962 	    !IS_ERR(fsid_key) &&
963 	    fsid_key->ek_mnt &&
964 	    (fsid_key->ek_mnt != nd.mnt || fsid_key->ek_dentry != nd.dentry) )
965 		goto finish;
966 
967 	if (exp) {
968 		/* just a flags/id/fsid update */
969 
970 		exp_fsid_unhash(exp);
971 		exp->ex_flags    = nxp->ex_flags;
972 		exp->ex_anon_uid = nxp->ex_anon_uid;
973 		exp->ex_anon_gid = nxp->ex_anon_gid;
974 		exp->ex_fsid     = nxp->ex_dev;
975 
976 		err = exp_fsid_hash(clp, exp);
977 		goto finish;
978 	}
979 
980 	err = check_export(nd.dentry->d_inode, nxp->ex_flags);
981 	if (err) goto finish;
982 
983 	err = -ENOMEM;
984 
985 	dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
986 
987 	new.h.expiry_time = NEVER;
988 	new.h.flags = 0;
989 	new.ex_path = kstrdup(nxp->ex_path, GFP_KERNEL);
990 	if (!new.ex_path)
991 		goto finish;
992 	new.ex_client = clp;
993 	new.ex_mnt = nd.mnt;
994 	new.ex_dentry = nd.dentry;
995 	new.ex_flags = nxp->ex_flags;
996 	new.ex_anon_uid = nxp->ex_anon_uid;
997 	new.ex_anon_gid = nxp->ex_anon_gid;
998 	new.ex_fsid = nxp->ex_dev;
999 
1000 	exp = svc_export_lookup(&new);
1001 	if (exp)
1002 		exp = svc_export_update(&new, exp);
1003 
1004 	if (!exp)
1005 		goto finish;
1006 
1007 	if (exp_hash(clp, exp) ||
1008 	    exp_fsid_hash(clp, exp)) {
1009 		/* failed to create at least one index */
1010 		exp_do_unexport(exp);
1011 		cache_flush();
1012 	} else
1013 		err = 0;
1014 finish:
1015 	if (new.ex_path)
1016 		kfree(new.ex_path);
1017 	if (exp)
1018 		exp_put(exp);
1019 	if (fsid_key && !IS_ERR(fsid_key))
1020 		cache_put(&fsid_key->h, &svc_expkey_cache);
1021 	if (clp)
1022 		auth_domain_put(clp);
1023 	path_release(&nd);
1024 out_unlock:
1025 	exp_writeunlock();
1026 out:
1027 	return err;
1028 }
1029 
1030 /*
1031  * Unexport a file system. The export entry has already
1032  * been removed from the client's list of exported fs's.
1033  */
1034 static void
1035 exp_do_unexport(svc_export *unexp)
1036 {
1037 	unexp->h.expiry_time = get_seconds()-1;
1038 	svc_export_cache.nextcheck = get_seconds();
1039 	exp_unhash(unexp);
1040 	exp_fsid_unhash(unexp);
1041 }
1042 
1043 
1044 /*
1045  * unexport syscall.
1046  */
1047 int
1048 exp_unexport(struct nfsctl_export *nxp)
1049 {
1050 	struct auth_domain *dom;
1051 	svc_export *exp;
1052 	struct nameidata nd;
1053 	int		err;
1054 
1055 	/* Consistency check */
1056 	if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
1057 	    !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
1058 		return -EINVAL;
1059 
1060 	exp_writelock();
1061 
1062 	err = -EINVAL;
1063 	dom = auth_domain_find(nxp->ex_client);
1064 	if (!dom) {
1065 		dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
1066 		goto out_unlock;
1067 	}
1068 
1069 	err = path_lookup(nxp->ex_path, 0, &nd);
1070 	if (err)
1071 		goto out_domain;
1072 
1073 	err = -EINVAL;
1074 	exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
1075 	path_release(&nd);
1076 	if (!exp)
1077 		goto out_domain;
1078 
1079 	exp_do_unexport(exp);
1080 	exp_put(exp);
1081 	err = 0;
1082 
1083 out_domain:
1084 	auth_domain_put(dom);
1085 	cache_flush();
1086 out_unlock:
1087 	exp_writeunlock();
1088 	return err;
1089 }
1090 
1091 /*
1092  * Obtain the root fh on behalf of a client.
1093  * This could be done in user space, but I feel that it adds some safety
1094  * since its harder to fool a kernel module than a user space program.
1095  */
1096 int
1097 exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
1098 {
1099 	struct svc_export	*exp;
1100 	struct nameidata	nd;
1101 	struct inode		*inode;
1102 	struct svc_fh		fh;
1103 	int			err;
1104 
1105 	err = -EPERM;
1106 	/* NB: we probably ought to check that it's NUL-terminated */
1107 	if (path_lookup(path, 0, &nd)) {
1108 		printk("nfsd: exp_rootfh path not found %s", path);
1109 		return err;
1110 	}
1111 	inode = nd.dentry->d_inode;
1112 
1113 	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
1114 		 path, nd.dentry, clp->name,
1115 		 inode->i_sb->s_id, inode->i_ino);
1116 	exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
1117 	if (IS_ERR(exp)) {
1118 		err = PTR_ERR(exp);
1119 		goto out;
1120 	}
1121 	if (!exp) {
1122 		dprintk("nfsd: exp_rootfh export not found.\n");
1123 		goto out;
1124 	}
1125 
1126 	/*
1127 	 * fh must be initialized before calling fh_compose
1128 	 */
1129 	fh_init(&fh, maxsize);
1130 	if (fh_compose(&fh, exp, nd.dentry, NULL))
1131 		err = -EINVAL;
1132 	else
1133 		err = 0;
1134 	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
1135 	fh_put(&fh);
1136 	exp_put(exp);
1137 out:
1138 	path_release(&nd);
1139 	return err;
1140 }
1141 
1142 struct svc_export *
1143 exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv,
1144 	 struct cache_req *reqp)
1145 {
1146 	struct svc_export *exp;
1147 	struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp);
1148 	if (!ek || IS_ERR(ek))
1149 		return ERR_PTR(PTR_ERR(ek));
1150 
1151 	exp = exp_get_by_name(clp, ek->ek_mnt, ek->ek_dentry, reqp);
1152 	cache_put(&ek->h, &svc_expkey_cache);
1153 
1154 	if (!exp || IS_ERR(exp))
1155 		return ERR_PTR(PTR_ERR(exp));
1156 	return exp;
1157 }
1158 
1159 
1160 /*
1161  * Called when we need the filehandle for the root of the pseudofs,
1162  * for a given NFSv4 client.   The root is defined to be the
1163  * export point with fsid==0
1164  */
1165 __be32
1166 exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
1167 	       struct cache_req *creq)
1168 {
1169 	struct svc_export *exp;
1170 	__be32 rv;
1171 	u32 fsidv[2];
1172 
1173 	mk_fsid_v1(fsidv, 0);
1174 
1175 	exp = exp_find(clp, 1, fsidv, creq);
1176 	if (IS_ERR(exp))
1177 		return nfserrno(PTR_ERR(exp));
1178 	if (exp == NULL)
1179 		return nfserr_perm;
1180 	rv = fh_compose(fhp, exp, exp->ex_dentry, NULL);
1181 	exp_put(exp);
1182 	return rv;
1183 }
1184 
1185 /* Iterator */
1186 
1187 static void *e_start(struct seq_file *m, loff_t *pos)
1188 	__acquires(svc_export_cache.hash_lock)
1189 {
1190 	loff_t n = *pos;
1191 	unsigned hash, export;
1192 	struct cache_head *ch;
1193 
1194 	exp_readlock();
1195 	read_lock(&svc_export_cache.hash_lock);
1196 	if (!n--)
1197 		return SEQ_START_TOKEN;
1198 	hash = n >> 32;
1199 	export = n & ((1LL<<32) - 1);
1200 
1201 
1202 	for (ch=export_table[hash]; ch; ch=ch->next)
1203 		if (!export--)
1204 			return ch;
1205 	n &= ~((1LL<<32) - 1);
1206 	do {
1207 		hash++;
1208 		n += 1LL<<32;
1209 	} while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
1210 	if (hash >= EXPORT_HASHMAX)
1211 		return NULL;
1212 	*pos = n+1;
1213 	return export_table[hash];
1214 }
1215 
1216 static void *e_next(struct seq_file *m, void *p, loff_t *pos)
1217 {
1218 	struct cache_head *ch = p;
1219 	int hash = (*pos >> 32);
1220 
1221 	if (p == SEQ_START_TOKEN)
1222 		hash = 0;
1223 	else if (ch->next == NULL) {
1224 		hash++;
1225 		*pos += 1LL<<32;
1226 	} else {
1227 		++*pos;
1228 		return ch->next;
1229 	}
1230 	*pos &= ~((1LL<<32) - 1);
1231 	while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
1232 		hash++;
1233 		*pos += 1LL<<32;
1234 	}
1235 	if (hash >= EXPORT_HASHMAX)
1236 		return NULL;
1237 	++*pos;
1238 	return export_table[hash];
1239 }
1240 
1241 static void e_stop(struct seq_file *m, void *p)
1242 	__releases(svc_export_cache.hash_lock)
1243 {
1244 	read_unlock(&svc_export_cache.hash_lock);
1245 	exp_readunlock();
1246 }
1247 
1248 static struct flags {
1249 	int flag;
1250 	char *name[2];
1251 } expflags[] = {
1252 	{ NFSEXP_READONLY, {"ro", "rw"}},
1253 	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1254 	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1255 	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1256 	{ NFSEXP_ASYNC, {"async", "sync"}},
1257 	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1258 	{ NFSEXP_NOHIDE, {"nohide", ""}},
1259 	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1260 	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1261 	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1262 #ifdef MSNFS
1263 	{ NFSEXP_MSNFS, {"msnfs", ""}},
1264 #endif
1265 	{ 0, {"", ""}}
1266 };
1267 
1268 static void exp_flags(struct seq_file *m, int flag, int fsid,
1269 		uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fsloc)
1270 {
1271 	int first = 0;
1272 	struct flags *flg;
1273 
1274 	for (flg = expflags; flg->flag; flg++) {
1275 		int state = (flg->flag & flag)?0:1;
1276 		if (*flg->name[state])
1277 			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1278 	}
1279 	if (flag & NFSEXP_FSID)
1280 		seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
1281 	if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1282 		seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
1283 	if (anong != (gid_t)-2 && anong != (0x10000-2))
1284 		seq_printf(m, "%sanongid=%d", first++?",":"", anong);
1285 	if (fsloc && fsloc->locations_count > 0) {
1286 		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1287 		int i;
1288 
1289 		seq_printf(m, "%s%s=", first++?",":"", loctype);
1290 		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1291 		seq_putc(m, '@');
1292 		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1293 		for (i = 1; i < fsloc->locations_count; i++) {
1294 			seq_putc(m, ';');
1295 			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1296 			seq_putc(m, '@');
1297 			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1298 		}
1299 	}
1300 }
1301 
1302 static int e_show(struct seq_file *m, void *p)
1303 {
1304 	struct cache_head *cp = p;
1305 	struct svc_export *exp = container_of(cp, struct svc_export, h);
1306 
1307 	if (p == SEQ_START_TOKEN) {
1308 		seq_puts(m, "# Version 1.1\n");
1309 		seq_puts(m, "# Path Client(Flags) # IPs\n");
1310 		return 0;
1311 	}
1312 
1313 	cache_get(&exp->h);
1314 	if (cache_check(&svc_export_cache, &exp->h, NULL))
1315 		return 0;
1316 	cache_put(&exp->h, &svc_export_cache);
1317 	return svc_export_show(m, &svc_export_cache, cp);
1318 }
1319 
1320 struct seq_operations nfs_exports_op = {
1321 	.start	= e_start,
1322 	.next	= e_next,
1323 	.stop	= e_stop,
1324 	.show	= e_show,
1325 };
1326 
1327 /*
1328  * Add or modify a client.
1329  * Change requests may involve the list of host addresses. The list of
1330  * exports and possibly existing uid maps are left untouched.
1331  */
1332 int
1333 exp_addclient(struct nfsctl_client *ncp)
1334 {
1335 	struct auth_domain	*dom;
1336 	int			i, err;
1337 
1338 	/* First, consistency check. */
1339 	err = -EINVAL;
1340 	if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1341 		goto out;
1342 	if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
1343 		goto out;
1344 
1345 	/* Lock the hashtable */
1346 	exp_writelock();
1347 
1348 	dom = unix_domain_find(ncp->cl_ident);
1349 
1350 	err = -ENOMEM;
1351 	if (!dom)
1352 		goto out_unlock;
1353 
1354 	/* Insert client into hashtable. */
1355 	for (i = 0; i < ncp->cl_naddr; i++)
1356 		auth_unix_add_addr(ncp->cl_addrlist[i], dom);
1357 
1358 	auth_unix_forget_old(dom);
1359 	auth_domain_put(dom);
1360 
1361 	err = 0;
1362 
1363 out_unlock:
1364 	exp_writeunlock();
1365 out:
1366 	return err;
1367 }
1368 
1369 /*
1370  * Delete a client given an identifier.
1371  */
1372 int
1373 exp_delclient(struct nfsctl_client *ncp)
1374 {
1375 	int		err;
1376 	struct auth_domain *dom;
1377 
1378 	err = -EINVAL;
1379 	if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1380 		goto out;
1381 
1382 	/* Lock the hashtable */
1383 	exp_writelock();
1384 
1385 	dom = auth_domain_find(ncp->cl_ident);
1386 	/* just make sure that no addresses work
1387 	 * and that it will expire soon
1388 	 */
1389 	if (dom) {
1390 		err = auth_unix_forget_old(dom);
1391 		auth_domain_put(dom);
1392 	}
1393 
1394 	exp_writeunlock();
1395 out:
1396 	return err;
1397 }
1398 
1399 /*
1400  * Verify that string is non-empty and does not exceed max length.
1401  */
1402 static int
1403 exp_verify_string(char *cp, int max)
1404 {
1405 	int	i;
1406 
1407 	for (i = 0; i < max; i++)
1408 		if (!cp[i])
1409 			return i;
1410 	cp[i] = 0;
1411 	printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
1412 	return 0;
1413 }
1414 
1415 /*
1416  * Initialize the exports module.
1417  */
1418 void
1419 nfsd_export_init(void)
1420 {
1421 	dprintk("nfsd: initializing export module.\n");
1422 
1423 	cache_register(&svc_export_cache);
1424 	cache_register(&svc_expkey_cache);
1425 
1426 }
1427 
1428 /*
1429  * Flush exports table - called when last nfsd thread is killed
1430  */
1431 void
1432 nfsd_export_flush(void)
1433 {
1434 	exp_writelock();
1435 	cache_purge(&svc_expkey_cache);
1436 	cache_purge(&svc_export_cache);
1437 	exp_writeunlock();
1438 }
1439 
1440 /*
1441  * Shutdown the exports module.
1442  */
1443 void
1444 nfsd_export_shutdown(void)
1445 {
1446 
1447 	dprintk("nfsd: shutting down export module.\n");
1448 
1449 	exp_writelock();
1450 
1451 	if (cache_unregister(&svc_expkey_cache))
1452 		printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
1453 	if (cache_unregister(&svc_export_cache))
1454 		printk(KERN_ERR "nfsd: failed to unregister export cache\n");
1455 	svcauth_unix_purge();
1456 
1457 	exp_writeunlock();
1458 	dprintk("nfsd: export shutdown complete.\n");
1459 }
1460