xref: /openbmc/linux/fs/nfsd/export.c (revision 33fb626b)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * NFS exporting and validation.
4   *
5   * We maintain a list of clients, each of which has a list of
6   * exports. To export an fs to a given client, you first have
7   * to create the client entry with NFSCTL_ADDCLIENT, which
8   * creates a client control block and adds it to the hash
9   * table. Then, you call NFSCTL_EXPORT for each fs.
10   *
11   *
12   * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
13   */
14  
15  #include <linux/slab.h>
16  #include <linux/namei.h>
17  #include <linux/module.h>
18  #include <linux/exportfs.h>
19  #include <linux/sunrpc/svc_xprt.h>
20  
21  #include "nfsd.h"
22  #include "nfsfh.h"
23  #include "netns.h"
24  #include "pnfs.h"
25  #include "filecache.h"
26  #include "trace.h"
27  
28  #define NFSDDBG_FACILITY	NFSDDBG_EXPORT
29  
30  /*
31   * We have two caches.
32   * One maps client+vfsmnt+dentry to export options - the export map
33   * The other maps client+filehandle-fragment to export options. - the expkey map
34   *
35   * The export options are actually stored in the first map, and the
36   * second map contains a reference to the entry in the first map.
37   */
38  
39  #define	EXPKEY_HASHBITS		8
40  #define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
41  #define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
42  
43  static void expkey_put(struct kref *ref)
44  {
45  	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
46  
47  	if (test_bit(CACHE_VALID, &key->h.flags) &&
48  	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
49  		path_put(&key->ek_path);
50  	auth_domain_put(key->ek_client);
51  	kfree_rcu(key, ek_rcu);
52  }
53  
54  static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
55  {
56  	return sunrpc_cache_pipe_upcall(cd, h);
57  }
58  
59  static void expkey_request(struct cache_detail *cd,
60  			   struct cache_head *h,
61  			   char **bpp, int *blen)
62  {
63  	/* client fsidtype \xfsid */
64  	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
65  	char type[5];
66  
67  	qword_add(bpp, blen, ek->ek_client->name);
68  	snprintf(type, 5, "%d", ek->ek_fsidtype);
69  	qword_add(bpp, blen, type);
70  	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
71  	(*bpp)[-1] = '\n';
72  }
73  
74  static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
75  					    struct svc_expkey *old);
76  static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
77  
78  static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
79  {
80  	/* client fsidtype fsid expiry [path] */
81  	char *buf;
82  	int len;
83  	struct auth_domain *dom = NULL;
84  	int err;
85  	int fsidtype;
86  	char *ep;
87  	struct svc_expkey key;
88  	struct svc_expkey *ek = NULL;
89  
90  	if (mesg[mlen - 1] != '\n')
91  		return -EINVAL;
92  	mesg[mlen-1] = 0;
93  
94  	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
95  	err = -ENOMEM;
96  	if (!buf)
97  		goto out;
98  
99  	err = -EINVAL;
100  	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
101  		goto out;
102  
103  	err = -ENOENT;
104  	dom = auth_domain_find(buf);
105  	if (!dom)
106  		goto out;
107  	dprintk("found domain %s\n", buf);
108  
109  	err = -EINVAL;
110  	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
111  		goto out;
112  	fsidtype = simple_strtoul(buf, &ep, 10);
113  	if (*ep)
114  		goto out;
115  	dprintk("found fsidtype %d\n", fsidtype);
116  	if (key_len(fsidtype)==0) /* invalid type */
117  		goto out;
118  	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
119  		goto out;
120  	dprintk("found fsid length %d\n", len);
121  	if (len != key_len(fsidtype))
122  		goto out;
123  
124  	/* OK, we seem to have a valid key */
125  	key.h.flags = 0;
126  	key.h.expiry_time = get_expiry(&mesg);
127  	if (key.h.expiry_time == 0)
128  		goto out;
129  
130  	key.ek_client = dom;
131  	key.ek_fsidtype = fsidtype;
132  	memcpy(key.ek_fsid, buf, len);
133  
134  	ek = svc_expkey_lookup(cd, &key);
135  	err = -ENOMEM;
136  	if (!ek)
137  		goto out;
138  
139  	/* now we want a pathname, or empty meaning NEGATIVE  */
140  	err = -EINVAL;
141  	len = qword_get(&mesg, buf, PAGE_SIZE);
142  	if (len < 0)
143  		goto out;
144  	dprintk("Path seems to be <%s>\n", buf);
145  	err = 0;
146  	if (len == 0) {
147  		set_bit(CACHE_NEGATIVE, &key.h.flags);
148  		ek = svc_expkey_update(cd, &key, ek);
149  		if (ek)
150  			trace_nfsd_expkey_update(ek, NULL);
151  		else
152  			err = -ENOMEM;
153  	} else {
154  		err = kern_path(buf, 0, &key.ek_path);
155  		if (err)
156  			goto out;
157  
158  		dprintk("Found the path %s\n", buf);
159  
160  		ek = svc_expkey_update(cd, &key, ek);
161  		if (ek)
162  			trace_nfsd_expkey_update(ek, buf);
163  		else
164  			err = -ENOMEM;
165  		path_put(&key.ek_path);
166  	}
167  	cache_flush();
168   out:
169  	if (ek)
170  		cache_put(&ek->h, cd);
171  	if (dom)
172  		auth_domain_put(dom);
173  	kfree(buf);
174  	return err;
175  }
176  
177  static int expkey_show(struct seq_file *m,
178  		       struct cache_detail *cd,
179  		       struct cache_head *h)
180  {
181  	struct svc_expkey *ek ;
182  	int i;
183  
184  	if (h ==NULL) {
185  		seq_puts(m, "#domain fsidtype fsid [path]\n");
186  		return 0;
187  	}
188  	ek = container_of(h, struct svc_expkey, h);
189  	seq_printf(m, "%s %d 0x", ek->ek_client->name,
190  		   ek->ek_fsidtype);
191  	for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
192  		seq_printf(m, "%08x", ek->ek_fsid[i]);
193  	if (test_bit(CACHE_VALID, &h->flags) &&
194  	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
195  		seq_printf(m, " ");
196  		seq_path(m, &ek->ek_path, "\\ \t\n");
197  	}
198  	seq_printf(m, "\n");
199  	return 0;
200  }
201  
202  static inline int expkey_match (struct cache_head *a, struct cache_head *b)
203  {
204  	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
205  	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
206  
207  	if (orig->ek_fsidtype != new->ek_fsidtype ||
208  	    orig->ek_client != new->ek_client ||
209  	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
210  		return 0;
211  	return 1;
212  }
213  
214  static inline void expkey_init(struct cache_head *cnew,
215  				   struct cache_head *citem)
216  {
217  	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
218  	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
219  
220  	kref_get(&item->ek_client->ref);
221  	new->ek_client = item->ek_client;
222  	new->ek_fsidtype = item->ek_fsidtype;
223  
224  	memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
225  }
226  
227  static inline void expkey_update(struct cache_head *cnew,
228  				   struct cache_head *citem)
229  {
230  	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
231  	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
232  
233  	new->ek_path = item->ek_path;
234  	path_get(&item->ek_path);
235  }
236  
237  static struct cache_head *expkey_alloc(void)
238  {
239  	struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
240  	if (i)
241  		return &i->h;
242  	else
243  		return NULL;
244  }
245  
246  static void expkey_flush(void)
247  {
248  	/*
249  	 * Take the nfsd_mutex here to ensure that the file cache is not
250  	 * destroyed while we're in the middle of flushing.
251  	 */
252  	mutex_lock(&nfsd_mutex);
253  	nfsd_file_cache_purge(current->nsproxy->net_ns);
254  	mutex_unlock(&nfsd_mutex);
255  }
256  
257  static const struct cache_detail svc_expkey_cache_template = {
258  	.owner		= THIS_MODULE,
259  	.hash_size	= EXPKEY_HASHMAX,
260  	.name		= "nfsd.fh",
261  	.cache_put	= expkey_put,
262  	.cache_upcall	= expkey_upcall,
263  	.cache_request	= expkey_request,
264  	.cache_parse	= expkey_parse,
265  	.cache_show	= expkey_show,
266  	.match		= expkey_match,
267  	.init		= expkey_init,
268  	.update       	= expkey_update,
269  	.alloc		= expkey_alloc,
270  	.flush		= expkey_flush,
271  };
272  
273  static int
274  svc_expkey_hash(struct svc_expkey *item)
275  {
276  	int hash = item->ek_fsidtype;
277  	char * cp = (char*)item->ek_fsid;
278  	int len = key_len(item->ek_fsidtype);
279  
280  	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
281  	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
282  	hash &= EXPKEY_HASHMASK;
283  	return hash;
284  }
285  
286  static struct svc_expkey *
287  svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
288  {
289  	struct cache_head *ch;
290  	int hash = svc_expkey_hash(item);
291  
292  	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
293  	if (ch)
294  		return container_of(ch, struct svc_expkey, h);
295  	else
296  		return NULL;
297  }
298  
299  static struct svc_expkey *
300  svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
301  		  struct svc_expkey *old)
302  {
303  	struct cache_head *ch;
304  	int hash = svc_expkey_hash(new);
305  
306  	ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
307  	if (ch)
308  		return container_of(ch, struct svc_expkey, h);
309  	else
310  		return NULL;
311  }
312  
313  
314  #define	EXPORT_HASHBITS		8
315  #define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
316  
317  static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
318  {
319  	struct nfsd4_fs_location *locations = fsloc->locations;
320  	int i;
321  
322  	if (!locations)
323  		return;
324  
325  	for (i = 0; i < fsloc->locations_count; i++) {
326  		kfree(locations[i].path);
327  		kfree(locations[i].hosts);
328  	}
329  
330  	kfree(locations);
331  	fsloc->locations = NULL;
332  }
333  
334  static void svc_export_put(struct kref *ref)
335  {
336  	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
337  	path_put(&exp->ex_path);
338  	auth_domain_put(exp->ex_client);
339  	nfsd4_fslocs_free(&exp->ex_fslocs);
340  	kfree(exp->ex_uuid);
341  	kfree_rcu(exp, ex_rcu);
342  }
343  
344  static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
345  {
346  	return sunrpc_cache_pipe_upcall(cd, h);
347  }
348  
349  static void svc_export_request(struct cache_detail *cd,
350  			       struct cache_head *h,
351  			       char **bpp, int *blen)
352  {
353  	/*  client path */
354  	struct svc_export *exp = container_of(h, struct svc_export, h);
355  	char *pth;
356  
357  	qword_add(bpp, blen, exp->ex_client->name);
358  	pth = d_path(&exp->ex_path, *bpp, *blen);
359  	if (IS_ERR(pth)) {
360  		/* is this correct? */
361  		(*bpp)[0] = '\n';
362  		return;
363  	}
364  	qword_add(bpp, blen, pth);
365  	(*bpp)[-1] = '\n';
366  }
367  
368  static struct svc_export *svc_export_update(struct svc_export *new,
369  					    struct svc_export *old);
370  static struct svc_export *svc_export_lookup(struct svc_export *);
371  
372  static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
373  {
374  
375  	/*
376  	 * We currently export only dirs, regular files, and (for v4
377  	 * pseudoroot) symlinks.
378  	 */
379  	if (!S_ISDIR(inode->i_mode) &&
380  	    !S_ISLNK(inode->i_mode) &&
381  	    !S_ISREG(inode->i_mode))
382  		return -ENOTDIR;
383  
384  	/*
385  	 * Mountd should never pass down a writeable V4ROOT export, but,
386  	 * just to make sure:
387  	 */
388  	if (*flags & NFSEXP_V4ROOT)
389  		*flags |= NFSEXP_READONLY;
390  
391  	/* There are two requirements on a filesystem to be exportable.
392  	 * 1:  We must be able to identify the filesystem from a number.
393  	 *       either a device number (so FS_REQUIRES_DEV needed)
394  	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
395  	 * 2:  We must be able to find an inode from a filehandle.
396  	 *       This means that s_export_op must be set.
397  	 */
398  	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
399  	    !(*flags & NFSEXP_FSID) &&
400  	    uuid == NULL) {
401  		dprintk("exp_export: export of non-dev fs without fsid\n");
402  		return -EINVAL;
403  	}
404  
405  	if (!inode->i_sb->s_export_op ||
406  	    !inode->i_sb->s_export_op->fh_to_dentry) {
407  		dprintk("exp_export: export of invalid fs type.\n");
408  		return -EINVAL;
409  	}
410  
411  	return 0;
412  
413  }
414  
415  #ifdef CONFIG_NFSD_V4
416  
417  static int
418  fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
419  {
420  	int len;
421  	int migrated, i, err;
422  
423  	/* more than one fsloc */
424  	if (fsloc->locations)
425  		return -EINVAL;
426  
427  	/* listsize */
428  	err = get_uint(mesg, &fsloc->locations_count);
429  	if (err)
430  		return err;
431  	if (fsloc->locations_count > MAX_FS_LOCATIONS)
432  		return -EINVAL;
433  	if (fsloc->locations_count == 0)
434  		return 0;
435  
436  	fsloc->locations = kcalloc(fsloc->locations_count,
437  				   sizeof(struct nfsd4_fs_location),
438  				   GFP_KERNEL);
439  	if (!fsloc->locations)
440  		return -ENOMEM;
441  	for (i=0; i < fsloc->locations_count; i++) {
442  		/* colon separated host list */
443  		err = -EINVAL;
444  		len = qword_get(mesg, buf, PAGE_SIZE);
445  		if (len <= 0)
446  			goto out_free_all;
447  		err = -ENOMEM;
448  		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
449  		if (!fsloc->locations[i].hosts)
450  			goto out_free_all;
451  		err = -EINVAL;
452  		/* slash separated path component list */
453  		len = qword_get(mesg, buf, PAGE_SIZE);
454  		if (len <= 0)
455  			goto out_free_all;
456  		err = -ENOMEM;
457  		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
458  		if (!fsloc->locations[i].path)
459  			goto out_free_all;
460  	}
461  	/* migrated */
462  	err = get_int(mesg, &migrated);
463  	if (err)
464  		goto out_free_all;
465  	err = -EINVAL;
466  	if (migrated < 0 || migrated > 1)
467  		goto out_free_all;
468  	fsloc->migrated = migrated;
469  	return 0;
470  out_free_all:
471  	nfsd4_fslocs_free(fsloc);
472  	return err;
473  }
474  
475  static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
476  {
477  	struct exp_flavor_info *f;
478  	u32 listsize;
479  	int err;
480  
481  	/* more than one secinfo */
482  	if (exp->ex_nflavors)
483  		return -EINVAL;
484  
485  	err = get_uint(mesg, &listsize);
486  	if (err)
487  		return err;
488  	if (listsize > MAX_SECINFO_LIST)
489  		return -EINVAL;
490  
491  	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
492  		err = get_uint(mesg, &f->pseudoflavor);
493  		if (err)
494  			return err;
495  		/*
496  		 * XXX: It would be nice to also check whether this
497  		 * pseudoflavor is supported, so we can discover the
498  		 * problem at export time instead of when a client fails
499  		 * to authenticate.
500  		 */
501  		err = get_uint(mesg, &f->flags);
502  		if (err)
503  			return err;
504  		/* Only some flags are allowed to differ between flavors: */
505  		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
506  			return -EINVAL;
507  	}
508  	exp->ex_nflavors = listsize;
509  	return 0;
510  }
511  
512  #else /* CONFIG_NFSD_V4 */
513  static inline int
514  fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
515  static inline int
516  secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
517  #endif
518  
519  static inline int
520  nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
521  {
522  	int len;
523  
524  	/* more than one uuid */
525  	if (*puuid)
526  		return -EINVAL;
527  
528  	/* expect a 16 byte uuid encoded as \xXXXX... */
529  	len = qword_get(mesg, buf, PAGE_SIZE);
530  	if (len != EX_UUID_LEN)
531  		return -EINVAL;
532  
533  	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
534  	if (*puuid == NULL)
535  		return -ENOMEM;
536  
537  	return 0;
538  }
539  
540  static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
541  {
542  	/* client path expiry [flags anonuid anongid fsid] */
543  	char *buf;
544  	int len;
545  	int err;
546  	struct auth_domain *dom = NULL;
547  	struct svc_export exp = {}, *expp;
548  	int an_int;
549  
550  	if (mesg[mlen-1] != '\n')
551  		return -EINVAL;
552  	mesg[mlen-1] = 0;
553  
554  	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
555  	if (!buf)
556  		return -ENOMEM;
557  
558  	/* client */
559  	err = -EINVAL;
560  	len = qword_get(&mesg, buf, PAGE_SIZE);
561  	if (len <= 0)
562  		goto out;
563  
564  	err = -ENOENT;
565  	dom = auth_domain_find(buf);
566  	if (!dom)
567  		goto out;
568  
569  	/* path */
570  	err = -EINVAL;
571  	if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
572  		goto out1;
573  
574  	err = kern_path(buf, 0, &exp.ex_path);
575  	if (err)
576  		goto out1;
577  
578  	exp.ex_client = dom;
579  	exp.cd = cd;
580  	exp.ex_devid_map = NULL;
581  
582  	/* expiry */
583  	err = -EINVAL;
584  	exp.h.expiry_time = get_expiry(&mesg);
585  	if (exp.h.expiry_time == 0)
586  		goto out3;
587  
588  	/* flags */
589  	err = get_int(&mesg, &an_int);
590  	if (err == -ENOENT) {
591  		err = 0;
592  		set_bit(CACHE_NEGATIVE, &exp.h.flags);
593  	} else {
594  		if (err || an_int < 0)
595  			goto out3;
596  		exp.ex_flags= an_int;
597  
598  		/* anon uid */
599  		err = get_int(&mesg, &an_int);
600  		if (err)
601  			goto out3;
602  		exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
603  
604  		/* anon gid */
605  		err = get_int(&mesg, &an_int);
606  		if (err)
607  			goto out3;
608  		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
609  
610  		/* fsid */
611  		err = get_int(&mesg, &an_int);
612  		if (err)
613  			goto out3;
614  		exp.ex_fsid = an_int;
615  
616  		while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
617  			if (strcmp(buf, "fsloc") == 0)
618  				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
619  			else if (strcmp(buf, "uuid") == 0)
620  				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
621  			else if (strcmp(buf, "secinfo") == 0)
622  				err = secinfo_parse(&mesg, buf, &exp);
623  			else
624  				/* quietly ignore unknown words and anything
625  				 * following. Newer user-space can try to set
626  				 * new values, then see what the result was.
627  				 */
628  				break;
629  			if (err)
630  				goto out4;
631  		}
632  
633  		err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags,
634  				   exp.ex_uuid);
635  		if (err)
636  			goto out4;
637  		/*
638  		 * No point caching this if it would immediately expire.
639  		 * Also, this protects exportfs's dummy export from the
640  		 * anon_uid/anon_gid checks:
641  		 */
642  		if (exp.h.expiry_time < seconds_since_boot())
643  			goto out4;
644  		/*
645  		 * For some reason exportfs has been passing down an
646  		 * invalid (-1) uid & gid on the "dummy" export which it
647  		 * uses to test export support.  To make sure exportfs
648  		 * sees errors from check_export we therefore need to
649  		 * delay these checks till after check_export:
650  		 */
651  		err = -EINVAL;
652  		if (!uid_valid(exp.ex_anon_uid))
653  			goto out4;
654  		if (!gid_valid(exp.ex_anon_gid))
655  			goto out4;
656  		err = 0;
657  
658  		nfsd4_setup_layout_type(&exp);
659  	}
660  
661  	expp = svc_export_lookup(&exp);
662  	if (!expp) {
663  		err = -ENOMEM;
664  		goto out4;
665  	}
666  	expp = svc_export_update(&exp, expp);
667  	if (expp) {
668  		trace_nfsd_export_update(expp);
669  		cache_flush();
670  		exp_put(expp);
671  	} else
672  		err = -ENOMEM;
673  out4:
674  	nfsd4_fslocs_free(&exp.ex_fslocs);
675  	kfree(exp.ex_uuid);
676  out3:
677  	path_put(&exp.ex_path);
678  out1:
679  	auth_domain_put(dom);
680  out:
681  	kfree(buf);
682  	return err;
683  }
684  
685  static void exp_flags(struct seq_file *m, int flag, int fsid,
686  		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
687  static void show_secinfo(struct seq_file *m, struct svc_export *exp);
688  
689  static int svc_export_show(struct seq_file *m,
690  			   struct cache_detail *cd,
691  			   struct cache_head *h)
692  {
693  	struct svc_export *exp ;
694  
695  	if (h ==NULL) {
696  		seq_puts(m, "#path domain(flags)\n");
697  		return 0;
698  	}
699  	exp = container_of(h, struct svc_export, h);
700  	seq_path(m, &exp->ex_path, " \t\n\\");
701  	seq_putc(m, '\t');
702  	seq_escape(m, exp->ex_client->name, " \t\n\\");
703  	seq_putc(m, '(');
704  	if (test_bit(CACHE_VALID, &h->flags) &&
705  	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
706  		exp_flags(m, exp->ex_flags, exp->ex_fsid,
707  			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
708  		if (exp->ex_uuid) {
709  			int i;
710  			seq_puts(m, ",uuid=");
711  			for (i = 0; i < EX_UUID_LEN; i++) {
712  				if ((i&3) == 0 && i)
713  					seq_putc(m, ':');
714  				seq_printf(m, "%02x", exp->ex_uuid[i]);
715  			}
716  		}
717  		show_secinfo(m, exp);
718  	}
719  	seq_puts(m, ")\n");
720  	return 0;
721  }
722  static int svc_export_match(struct cache_head *a, struct cache_head *b)
723  {
724  	struct svc_export *orig = container_of(a, struct svc_export, h);
725  	struct svc_export *new = container_of(b, struct svc_export, h);
726  	return orig->ex_client == new->ex_client &&
727  		path_equal(&orig->ex_path, &new->ex_path);
728  }
729  
730  static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
731  {
732  	struct svc_export *new = container_of(cnew, struct svc_export, h);
733  	struct svc_export *item = container_of(citem, struct svc_export, h);
734  
735  	kref_get(&item->ex_client->ref);
736  	new->ex_client = item->ex_client;
737  	new->ex_path = item->ex_path;
738  	path_get(&item->ex_path);
739  	new->ex_fslocs.locations = NULL;
740  	new->ex_fslocs.locations_count = 0;
741  	new->ex_fslocs.migrated = 0;
742  	new->ex_layout_types = 0;
743  	new->ex_uuid = NULL;
744  	new->cd = item->cd;
745  }
746  
747  static void export_update(struct cache_head *cnew, struct cache_head *citem)
748  {
749  	struct svc_export *new = container_of(cnew, struct svc_export, h);
750  	struct svc_export *item = container_of(citem, struct svc_export, h);
751  	int i;
752  
753  	new->ex_flags = item->ex_flags;
754  	new->ex_anon_uid = item->ex_anon_uid;
755  	new->ex_anon_gid = item->ex_anon_gid;
756  	new->ex_fsid = item->ex_fsid;
757  	new->ex_devid_map = item->ex_devid_map;
758  	item->ex_devid_map = NULL;
759  	new->ex_uuid = item->ex_uuid;
760  	item->ex_uuid = NULL;
761  	new->ex_fslocs.locations = item->ex_fslocs.locations;
762  	item->ex_fslocs.locations = NULL;
763  	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
764  	item->ex_fslocs.locations_count = 0;
765  	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
766  	item->ex_fslocs.migrated = 0;
767  	new->ex_layout_types = item->ex_layout_types;
768  	new->ex_nflavors = item->ex_nflavors;
769  	for (i = 0; i < MAX_SECINFO_LIST; i++) {
770  		new->ex_flavors[i] = item->ex_flavors[i];
771  	}
772  }
773  
774  static struct cache_head *svc_export_alloc(void)
775  {
776  	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
777  	if (i)
778  		return &i->h;
779  	else
780  		return NULL;
781  }
782  
783  static const struct cache_detail svc_export_cache_template = {
784  	.owner		= THIS_MODULE,
785  	.hash_size	= EXPORT_HASHMAX,
786  	.name		= "nfsd.export",
787  	.cache_put	= svc_export_put,
788  	.cache_upcall	= svc_export_upcall,
789  	.cache_request	= svc_export_request,
790  	.cache_parse	= svc_export_parse,
791  	.cache_show	= svc_export_show,
792  	.match		= svc_export_match,
793  	.init		= svc_export_init,
794  	.update		= export_update,
795  	.alloc		= svc_export_alloc,
796  };
797  
798  static int
799  svc_export_hash(struct svc_export *exp)
800  {
801  	int hash;
802  
803  	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
804  	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
805  	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
806  	return hash;
807  }
808  
809  static struct svc_export *
810  svc_export_lookup(struct svc_export *exp)
811  {
812  	struct cache_head *ch;
813  	int hash = svc_export_hash(exp);
814  
815  	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
816  	if (ch)
817  		return container_of(ch, struct svc_export, h);
818  	else
819  		return NULL;
820  }
821  
822  static struct svc_export *
823  svc_export_update(struct svc_export *new, struct svc_export *old)
824  {
825  	struct cache_head *ch;
826  	int hash = svc_export_hash(old);
827  
828  	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
829  	if (ch)
830  		return container_of(ch, struct svc_export, h);
831  	else
832  		return NULL;
833  }
834  
835  
836  static struct svc_expkey *
837  exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
838  	     u32 *fsidv, struct cache_req *reqp)
839  {
840  	struct svc_expkey key, *ek;
841  	int err;
842  
843  	if (!clp)
844  		return ERR_PTR(-ENOENT);
845  
846  	key.ek_client = clp;
847  	key.ek_fsidtype = fsid_type;
848  	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
849  
850  	ek = svc_expkey_lookup(cd, &key);
851  	if (ek == NULL)
852  		return ERR_PTR(-ENOMEM);
853  	err = cache_check(cd, &ek->h, reqp);
854  	if (err) {
855  		trace_nfsd_exp_find_key(&key, err);
856  		return ERR_PTR(err);
857  	}
858  	return ek;
859  }
860  
861  static struct svc_export *
862  exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
863  		const struct path *path, struct cache_req *reqp)
864  {
865  	struct svc_export *exp, key;
866  	int err;
867  
868  	if (!clp)
869  		return ERR_PTR(-ENOENT);
870  
871  	key.ex_client = clp;
872  	key.ex_path = *path;
873  	key.cd = cd;
874  
875  	exp = svc_export_lookup(&key);
876  	if (exp == NULL)
877  		return ERR_PTR(-ENOMEM);
878  	err = cache_check(cd, &exp->h, reqp);
879  	if (err) {
880  		trace_nfsd_exp_get_by_name(&key, err);
881  		return ERR_PTR(err);
882  	}
883  	return exp;
884  }
885  
886  /*
887   * Find the export entry for a given dentry.
888   */
889  static struct svc_export *
890  exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
891  {
892  	struct dentry *saved = dget(path->dentry);
893  	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
894  
895  	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
896  		struct dentry *parent = dget_parent(path->dentry);
897  		dput(path->dentry);
898  		path->dentry = parent;
899  		exp = exp_get_by_name(cd, clp, path, NULL);
900  	}
901  	dput(path->dentry);
902  	path->dentry = saved;
903  	return exp;
904  }
905  
906  
907  
908  /*
909   * Obtain the root fh on behalf of a client.
910   * This could be done in user space, but I feel that it adds some safety
911   * since its harder to fool a kernel module than a user space program.
912   */
913  int
914  exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
915  	   struct knfsd_fh *f, int maxsize)
916  {
917  	struct svc_export	*exp;
918  	struct path		path;
919  	struct inode		*inode;
920  	struct svc_fh		fh;
921  	int			err;
922  	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
923  	struct cache_detail	*cd = nn->svc_export_cache;
924  
925  	err = -EPERM;
926  	/* NB: we probably ought to check that it's NUL-terminated */
927  	if (kern_path(name, 0, &path)) {
928  		printk("nfsd: exp_rootfh path not found %s", name);
929  		return err;
930  	}
931  	inode = d_inode(path.dentry);
932  
933  	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
934  		 name, path.dentry, clp->name,
935  		 inode->i_sb->s_id, inode->i_ino);
936  	exp = exp_parent(cd, clp, &path);
937  	if (IS_ERR(exp)) {
938  		err = PTR_ERR(exp);
939  		goto out;
940  	}
941  
942  	/*
943  	 * fh must be initialized before calling fh_compose
944  	 */
945  	fh_init(&fh, maxsize);
946  	if (fh_compose(&fh, exp, path.dentry, NULL))
947  		err = -EINVAL;
948  	else
949  		err = 0;
950  	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
951  	fh_put(&fh);
952  	exp_put(exp);
953  out:
954  	path_put(&path);
955  	return err;
956  }
957  
958  static struct svc_export *exp_find(struct cache_detail *cd,
959  				   struct auth_domain *clp, int fsid_type,
960  				   u32 *fsidv, struct cache_req *reqp)
961  {
962  	struct svc_export *exp;
963  	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
964  	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
965  	if (IS_ERR(ek))
966  		return ERR_CAST(ek);
967  
968  	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
969  	cache_put(&ek->h, nn->svc_expkey_cache);
970  
971  	if (IS_ERR(exp))
972  		return ERR_CAST(exp);
973  	return exp;
974  }
975  
976  __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
977  {
978  	struct exp_flavor_info *f;
979  	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
980  
981  	/* legacy gss-only clients are always OK: */
982  	if (exp->ex_client == rqstp->rq_gssclient)
983  		return 0;
984  	/* ip-address based client; check sec= export option: */
985  	for (f = exp->ex_flavors; f < end; f++) {
986  		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
987  			return 0;
988  	}
989  	/* defaults in absence of sec= options: */
990  	if (exp->ex_nflavors == 0) {
991  		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
992  		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
993  			return 0;
994  	}
995  
996  	/* If the compound op contains a spo_must_allowed op,
997  	 * it will be sent with integrity/protection which
998  	 * will have to be expressly allowed on mounts that
999  	 * don't support it
1000  	 */
1001  
1002  	if (nfsd4_spo_must_allow(rqstp))
1003  		return 0;
1004  
1005  	return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec;
1006  }
1007  
1008  /*
1009   * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
1010   * auth_unix client) if it's available and has secinfo information;
1011   * otherwise, will try to use rq_gssclient.
1012   *
1013   * Called from functions that handle requests; functions that do work on
1014   * behalf of mountd are passed a single client name to use, and should
1015   * use exp_get_by_name() or exp_find().
1016   */
1017  struct svc_export *
1018  rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
1019  {
1020  	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1021  	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1022  	struct cache_detail *cd = nn->svc_export_cache;
1023  
1024  	if (rqstp->rq_client == NULL)
1025  		goto gss;
1026  
1027  	/* First try the auth_unix client: */
1028  	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
1029  	if (PTR_ERR(exp) == -ENOENT)
1030  		goto gss;
1031  	if (IS_ERR(exp))
1032  		return exp;
1033  	/* If it has secinfo, assume there are no gss/... clients */
1034  	if (exp->ex_nflavors > 0)
1035  		return exp;
1036  gss:
1037  	/* Otherwise, try falling back on gss client */
1038  	if (rqstp->rq_gssclient == NULL)
1039  		return exp;
1040  	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1041  	if (PTR_ERR(gssexp) == -ENOENT)
1042  		return exp;
1043  	if (!IS_ERR(exp))
1044  		exp_put(exp);
1045  	return gssexp;
1046  }
1047  
1048  struct svc_export *
1049  rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1050  {
1051  	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1052  	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1053  	struct cache_detail *cd = nn->svc_export_cache;
1054  
1055  	if (rqstp->rq_client == NULL)
1056  		goto gss;
1057  
1058  	/* First try the auth_unix client: */
1059  	exp = exp_find(cd, rqstp->rq_client, fsid_type,
1060  		       fsidv, &rqstp->rq_chandle);
1061  	if (PTR_ERR(exp) == -ENOENT)
1062  		goto gss;
1063  	if (IS_ERR(exp))
1064  		return exp;
1065  	/* If it has secinfo, assume there are no gss/... clients */
1066  	if (exp->ex_nflavors > 0)
1067  		return exp;
1068  gss:
1069  	/* Otherwise, try falling back on gss client */
1070  	if (rqstp->rq_gssclient == NULL)
1071  		return exp;
1072  	gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1073  						&rqstp->rq_chandle);
1074  	if (PTR_ERR(gssexp) == -ENOENT)
1075  		return exp;
1076  	if (!IS_ERR(exp))
1077  		exp_put(exp);
1078  	return gssexp;
1079  }
1080  
1081  struct svc_export *
1082  rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1083  {
1084  	struct dentry *saved = dget(path->dentry);
1085  	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1086  
1087  	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1088  		struct dentry *parent = dget_parent(path->dentry);
1089  		dput(path->dentry);
1090  		path->dentry = parent;
1091  		exp = rqst_exp_get_by_name(rqstp, path);
1092  	}
1093  	dput(path->dentry);
1094  	path->dentry = saved;
1095  	return exp;
1096  }
1097  
1098  struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1099  {
1100  	u32 fsidv[2];
1101  
1102  	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1103  
1104  	return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1105  }
1106  
1107  /*
1108   * Called when we need the filehandle for the root of the pseudofs,
1109   * for a given NFSv4 client.   The root is defined to be the
1110   * export point with fsid==0
1111   */
1112  __be32
1113  exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1114  {
1115  	struct svc_export *exp;
1116  	__be32 rv;
1117  
1118  	exp = rqst_find_fsidzero_export(rqstp);
1119  	if (IS_ERR(exp))
1120  		return nfserrno(PTR_ERR(exp));
1121  	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1122  	exp_put(exp);
1123  	return rv;
1124  }
1125  
1126  static struct flags {
1127  	int flag;
1128  	char *name[2];
1129  } expflags[] = {
1130  	{ NFSEXP_READONLY, {"ro", "rw"}},
1131  	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1132  	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1133  	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1134  	{ NFSEXP_ASYNC, {"async", "sync"}},
1135  	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1136  	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1137  	{ NFSEXP_NOHIDE, {"nohide", ""}},
1138  	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1139  	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1140  	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1141  	{ NFSEXP_V4ROOT, {"v4root", ""}},
1142  	{ NFSEXP_PNFS, {"pnfs", ""}},
1143  	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1144  	{ 0, {"", ""}}
1145  };
1146  
1147  static void show_expflags(struct seq_file *m, int flags, int mask)
1148  {
1149  	struct flags *flg;
1150  	int state, first = 0;
1151  
1152  	for (flg = expflags; flg->flag; flg++) {
1153  		if (flg->flag & ~mask)
1154  			continue;
1155  		state = (flg->flag & flags) ? 0 : 1;
1156  		if (*flg->name[state])
1157  			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1158  	}
1159  }
1160  
1161  static void show_secinfo_flags(struct seq_file *m, int flags)
1162  {
1163  	seq_printf(m, ",");
1164  	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1165  }
1166  
1167  static bool secinfo_flags_equal(int f, int g)
1168  {
1169  	f &= NFSEXP_SECINFO_FLAGS;
1170  	g &= NFSEXP_SECINFO_FLAGS;
1171  	return f == g;
1172  }
1173  
1174  static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1175  {
1176  	int flags;
1177  
1178  	flags = (*fp)->flags;
1179  	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1180  	(*fp)++;
1181  	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1182  		seq_printf(m, ":%d", (*fp)->pseudoflavor);
1183  		(*fp)++;
1184  	}
1185  	return flags;
1186  }
1187  
1188  static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1189  {
1190  	struct exp_flavor_info *f;
1191  	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1192  	int flags;
1193  
1194  	if (exp->ex_nflavors == 0)
1195  		return;
1196  	f = exp->ex_flavors;
1197  	flags = show_secinfo_run(m, &f, end);
1198  	if (!secinfo_flags_equal(flags, exp->ex_flags))
1199  		show_secinfo_flags(m, flags);
1200  	while (f != end) {
1201  		flags = show_secinfo_run(m, &f, end);
1202  		show_secinfo_flags(m, flags);
1203  	}
1204  }
1205  
1206  static void exp_flags(struct seq_file *m, int flag, int fsid,
1207  		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1208  {
1209  	struct user_namespace *userns = m->file->f_cred->user_ns;
1210  
1211  	show_expflags(m, flag, NFSEXP_ALLFLAGS);
1212  	if (flag & NFSEXP_FSID)
1213  		seq_printf(m, ",fsid=%d", fsid);
1214  	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
1215  	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
1216  		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
1217  	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
1218  	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
1219  		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
1220  	if (fsloc && fsloc->locations_count > 0) {
1221  		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1222  		int i;
1223  
1224  		seq_printf(m, ",%s=", loctype);
1225  		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1226  		seq_putc(m, '@');
1227  		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1228  		for (i = 1; i < fsloc->locations_count; i++) {
1229  			seq_putc(m, ';');
1230  			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1231  			seq_putc(m, '@');
1232  			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1233  		}
1234  	}
1235  }
1236  
1237  static int e_show(struct seq_file *m, void *p)
1238  {
1239  	struct cache_head *cp = p;
1240  	struct svc_export *exp = container_of(cp, struct svc_export, h);
1241  	struct cache_detail *cd = m->private;
1242  
1243  	if (p == SEQ_START_TOKEN) {
1244  		seq_puts(m, "# Version 1.1\n");
1245  		seq_puts(m, "# Path Client(Flags) # IPs\n");
1246  		return 0;
1247  	}
1248  
1249  	exp_get(exp);
1250  	if (cache_check(cd, &exp->h, NULL))
1251  		return 0;
1252  	exp_put(exp);
1253  	return svc_export_show(m, cd, cp);
1254  }
1255  
1256  const struct seq_operations nfs_exports_op = {
1257  	.start	= cache_seq_start_rcu,
1258  	.next	= cache_seq_next_rcu,
1259  	.stop	= cache_seq_stop_rcu,
1260  	.show	= e_show,
1261  };
1262  
1263  /*
1264   * Initialize the exports module.
1265   */
1266  int
1267  nfsd_export_init(struct net *net)
1268  {
1269  	int rv;
1270  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1271  
1272  	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1273  
1274  	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1275  	if (IS_ERR(nn->svc_export_cache))
1276  		return PTR_ERR(nn->svc_export_cache);
1277  	rv = cache_register_net(nn->svc_export_cache, net);
1278  	if (rv)
1279  		goto destroy_export_cache;
1280  
1281  	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1282  	if (IS_ERR(nn->svc_expkey_cache)) {
1283  		rv = PTR_ERR(nn->svc_expkey_cache);
1284  		goto unregister_export_cache;
1285  	}
1286  	rv = cache_register_net(nn->svc_expkey_cache, net);
1287  	if (rv)
1288  		goto destroy_expkey_cache;
1289  	return 0;
1290  
1291  destroy_expkey_cache:
1292  	cache_destroy_net(nn->svc_expkey_cache, net);
1293  unregister_export_cache:
1294  	cache_unregister_net(nn->svc_export_cache, net);
1295  destroy_export_cache:
1296  	cache_destroy_net(nn->svc_export_cache, net);
1297  	return rv;
1298  }
1299  
1300  /*
1301   * Flush exports table - called when last nfsd thread is killed
1302   */
1303  void
1304  nfsd_export_flush(struct net *net)
1305  {
1306  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1307  
1308  	cache_purge(nn->svc_expkey_cache);
1309  	cache_purge(nn->svc_export_cache);
1310  }
1311  
1312  /*
1313   * Shutdown the exports module.
1314   */
1315  void
1316  nfsd_export_shutdown(struct net *net)
1317  {
1318  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1319  
1320  	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1321  
1322  	cache_unregister_net(nn->svc_expkey_cache, net);
1323  	cache_unregister_net(nn->svc_export_cache, net);
1324  	cache_destroy_net(nn->svc_expkey_cache, net);
1325  	cache_destroy_net(nn->svc_export_cache, net);
1326  	svcauth_unix_purge(net);
1327  
1328  	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1329  }
1330