xref: /openbmc/linux/fs/nfsd/export.c (revision d6344cc8)
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 (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 (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  	err = get_expiry(&mesg, &key.h.expiry_time);
127  	if (err)
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 int export_stats_init(struct export_stats *stats)
335  {
336  	stats->start_time = ktime_get_seconds();
337  	return nfsd_percpu_counters_init(stats->counter, EXP_STATS_COUNTERS_NUM);
338  }
339  
340  static void export_stats_reset(struct export_stats *stats)
341  {
342  	if (stats)
343  		nfsd_percpu_counters_reset(stats->counter,
344  					   EXP_STATS_COUNTERS_NUM);
345  }
346  
347  static void export_stats_destroy(struct export_stats *stats)
348  {
349  	if (stats)
350  		nfsd_percpu_counters_destroy(stats->counter,
351  					     EXP_STATS_COUNTERS_NUM);
352  }
353  
354  static void svc_export_put(struct kref *ref)
355  {
356  	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
357  	path_put(&exp->ex_path);
358  	auth_domain_put(exp->ex_client);
359  	nfsd4_fslocs_free(&exp->ex_fslocs);
360  	export_stats_destroy(exp->ex_stats);
361  	kfree(exp->ex_stats);
362  	kfree(exp->ex_uuid);
363  	kfree_rcu(exp, ex_rcu);
364  }
365  
366  static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
367  {
368  	return sunrpc_cache_pipe_upcall(cd, h);
369  }
370  
371  static void svc_export_request(struct cache_detail *cd,
372  			       struct cache_head *h,
373  			       char **bpp, int *blen)
374  {
375  	/*  client path */
376  	struct svc_export *exp = container_of(h, struct svc_export, h);
377  	char *pth;
378  
379  	qword_add(bpp, blen, exp->ex_client->name);
380  	pth = d_path(&exp->ex_path, *bpp, *blen);
381  	if (IS_ERR(pth)) {
382  		/* is this correct? */
383  		(*bpp)[0] = '\n';
384  		return;
385  	}
386  	qword_add(bpp, blen, pth);
387  	(*bpp)[-1] = '\n';
388  }
389  
390  static struct svc_export *svc_export_update(struct svc_export *new,
391  					    struct svc_export *old);
392  static struct svc_export *svc_export_lookup(struct svc_export *);
393  
394  static int check_export(struct path *path, int *flags, unsigned char *uuid)
395  {
396  	struct inode *inode = d_inode(path->dentry);
397  
398  	/*
399  	 * We currently export only dirs, regular files, and (for v4
400  	 * pseudoroot) symlinks.
401  	 */
402  	if (!S_ISDIR(inode->i_mode) &&
403  	    !S_ISLNK(inode->i_mode) &&
404  	    !S_ISREG(inode->i_mode))
405  		return -ENOTDIR;
406  
407  	/*
408  	 * Mountd should never pass down a writeable V4ROOT export, but,
409  	 * just to make sure:
410  	 */
411  	if (*flags & NFSEXP_V4ROOT)
412  		*flags |= NFSEXP_READONLY;
413  
414  	/* There are two requirements on a filesystem to be exportable.
415  	 * 1:  We must be able to identify the filesystem from a number.
416  	 *       either a device number (so FS_REQUIRES_DEV needed)
417  	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
418  	 * 2:  We must be able to find an inode from a filehandle.
419  	 *       This means that s_export_op must be set.
420  	 * 3: We must not currently be on an idmapped mount.
421  	 */
422  	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
423  	    !(*flags & NFSEXP_FSID) &&
424  	    uuid == NULL) {
425  		dprintk("exp_export: export of non-dev fs without fsid\n");
426  		return -EINVAL;
427  	}
428  
429  	if (!inode->i_sb->s_export_op ||
430  	    !inode->i_sb->s_export_op->fh_to_dentry) {
431  		dprintk("exp_export: export of invalid fs type.\n");
432  		return -EINVAL;
433  	}
434  
435  	if (is_idmapped_mnt(path->mnt)) {
436  		dprintk("exp_export: export of idmapped mounts not yet supported.\n");
437  		return -EINVAL;
438  	}
439  
440  	if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK &&
441  	    !(*flags & NFSEXP_NOSUBTREECHECK)) {
442  		dprintk("%s: %s does not support subtree checking!\n",
443  			__func__, inode->i_sb->s_type->name);
444  		return -EINVAL;
445  	}
446  	return 0;
447  }
448  
449  #ifdef CONFIG_NFSD_V4
450  
451  static int
452  fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
453  {
454  	int len;
455  	int migrated, i, err;
456  
457  	/* more than one fsloc */
458  	if (fsloc->locations)
459  		return -EINVAL;
460  
461  	/* listsize */
462  	err = get_uint(mesg, &fsloc->locations_count);
463  	if (err)
464  		return err;
465  	if (fsloc->locations_count > MAX_FS_LOCATIONS)
466  		return -EINVAL;
467  	if (fsloc->locations_count == 0)
468  		return 0;
469  
470  	fsloc->locations = kcalloc(fsloc->locations_count,
471  				   sizeof(struct nfsd4_fs_location),
472  				   GFP_KERNEL);
473  	if (!fsloc->locations)
474  		return -ENOMEM;
475  	for (i=0; i < fsloc->locations_count; i++) {
476  		/* colon separated host list */
477  		err = -EINVAL;
478  		len = qword_get(mesg, buf, PAGE_SIZE);
479  		if (len <= 0)
480  			goto out_free_all;
481  		err = -ENOMEM;
482  		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
483  		if (!fsloc->locations[i].hosts)
484  			goto out_free_all;
485  		err = -EINVAL;
486  		/* slash separated path component list */
487  		len = qword_get(mesg, buf, PAGE_SIZE);
488  		if (len <= 0)
489  			goto out_free_all;
490  		err = -ENOMEM;
491  		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
492  		if (!fsloc->locations[i].path)
493  			goto out_free_all;
494  	}
495  	/* migrated */
496  	err = get_int(mesg, &migrated);
497  	if (err)
498  		goto out_free_all;
499  	err = -EINVAL;
500  	if (migrated < 0 || migrated > 1)
501  		goto out_free_all;
502  	fsloc->migrated = migrated;
503  	return 0;
504  out_free_all:
505  	nfsd4_fslocs_free(fsloc);
506  	return err;
507  }
508  
509  static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
510  {
511  	struct exp_flavor_info *f;
512  	u32 listsize;
513  	int err;
514  
515  	/* more than one secinfo */
516  	if (exp->ex_nflavors)
517  		return -EINVAL;
518  
519  	err = get_uint(mesg, &listsize);
520  	if (err)
521  		return err;
522  	if (listsize > MAX_SECINFO_LIST)
523  		return -EINVAL;
524  
525  	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
526  		err = get_uint(mesg, &f->pseudoflavor);
527  		if (err)
528  			return err;
529  		/*
530  		 * XXX: It would be nice to also check whether this
531  		 * pseudoflavor is supported, so we can discover the
532  		 * problem at export time instead of when a client fails
533  		 * to authenticate.
534  		 */
535  		err = get_uint(mesg, &f->flags);
536  		if (err)
537  			return err;
538  		/* Only some flags are allowed to differ between flavors: */
539  		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
540  			return -EINVAL;
541  	}
542  	exp->ex_nflavors = listsize;
543  	return 0;
544  }
545  
546  #else /* CONFIG_NFSD_V4 */
547  static inline int
548  fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
549  static inline int
550  secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
551  #endif
552  
553  static int xprtsec_parse(char **mesg, char *buf, struct svc_export *exp)
554  {
555  	unsigned int i, mode, listsize;
556  	int err;
557  
558  	err = get_uint(mesg, &listsize);
559  	if (err)
560  		return err;
561  	if (listsize > NFSEXP_XPRTSEC_NUM)
562  		return -EINVAL;
563  
564  	exp->ex_xprtsec_modes = 0;
565  	for (i = 0; i < listsize; i++) {
566  		err = get_uint(mesg, &mode);
567  		if (err)
568  			return err;
569  		if (mode > NFSEXP_XPRTSEC_MTLS)
570  			return -EINVAL;
571  		exp->ex_xprtsec_modes |= mode;
572  	}
573  	return 0;
574  }
575  
576  static inline int
577  nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
578  {
579  	int len;
580  
581  	/* more than one uuid */
582  	if (*puuid)
583  		return -EINVAL;
584  
585  	/* expect a 16 byte uuid encoded as \xXXXX... */
586  	len = qword_get(mesg, buf, PAGE_SIZE);
587  	if (len != EX_UUID_LEN)
588  		return -EINVAL;
589  
590  	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
591  	if (*puuid == NULL)
592  		return -ENOMEM;
593  
594  	return 0;
595  }
596  
597  static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
598  {
599  	/* client path expiry [flags anonuid anongid fsid] */
600  	char *buf;
601  	int err;
602  	struct auth_domain *dom = NULL;
603  	struct svc_export exp = {}, *expp;
604  	int an_int;
605  
606  	if (mesg[mlen-1] != '\n')
607  		return -EINVAL;
608  	mesg[mlen-1] = 0;
609  
610  	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
611  	if (!buf)
612  		return -ENOMEM;
613  
614  	/* client */
615  	err = -EINVAL;
616  	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
617  		goto out;
618  
619  	err = -ENOENT;
620  	dom = auth_domain_find(buf);
621  	if (!dom)
622  		goto out;
623  
624  	/* path */
625  	err = -EINVAL;
626  	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
627  		goto out1;
628  
629  	err = kern_path(buf, 0, &exp.ex_path);
630  	if (err)
631  		goto out1;
632  
633  	exp.ex_client = dom;
634  	exp.cd = cd;
635  	exp.ex_devid_map = NULL;
636  	exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL;
637  
638  	/* expiry */
639  	err = get_expiry(&mesg, &exp.h.expiry_time);
640  	if (err)
641  		goto out3;
642  
643  	/* flags */
644  	err = get_int(&mesg, &an_int);
645  	if (err == -ENOENT) {
646  		err = 0;
647  		set_bit(CACHE_NEGATIVE, &exp.h.flags);
648  	} else {
649  		if (err || an_int < 0)
650  			goto out3;
651  		exp.ex_flags= an_int;
652  
653  		/* anon uid */
654  		err = get_int(&mesg, &an_int);
655  		if (err)
656  			goto out3;
657  		exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
658  
659  		/* anon gid */
660  		err = get_int(&mesg, &an_int);
661  		if (err)
662  			goto out3;
663  		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
664  
665  		/* fsid */
666  		err = get_int(&mesg, &an_int);
667  		if (err)
668  			goto out3;
669  		exp.ex_fsid = an_int;
670  
671  		while (qword_get(&mesg, buf, PAGE_SIZE) > 0) {
672  			if (strcmp(buf, "fsloc") == 0)
673  				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
674  			else if (strcmp(buf, "uuid") == 0)
675  				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
676  			else if (strcmp(buf, "secinfo") == 0)
677  				err = secinfo_parse(&mesg, buf, &exp);
678  			else if (strcmp(buf, "xprtsec") == 0)
679  				err = xprtsec_parse(&mesg, buf, &exp);
680  			else
681  				/* quietly ignore unknown words and anything
682  				 * following. Newer user-space can try to set
683  				 * new values, then see what the result was.
684  				 */
685  				break;
686  			if (err)
687  				goto out4;
688  		}
689  
690  		err = check_export(&exp.ex_path, &exp.ex_flags, exp.ex_uuid);
691  		if (err)
692  			goto out4;
693  
694  		/*
695  		 * No point caching this if it would immediately expire.
696  		 * Also, this protects exportfs's dummy export from the
697  		 * anon_uid/anon_gid checks:
698  		 */
699  		if (exp.h.expiry_time < seconds_since_boot())
700  			goto out4;
701  		/*
702  		 * For some reason exportfs has been passing down an
703  		 * invalid (-1) uid & gid on the "dummy" export which it
704  		 * uses to test export support.  To make sure exportfs
705  		 * sees errors from check_export we therefore need to
706  		 * delay these checks till after check_export:
707  		 */
708  		err = -EINVAL;
709  		if (!uid_valid(exp.ex_anon_uid))
710  			goto out4;
711  		if (!gid_valid(exp.ex_anon_gid))
712  			goto out4;
713  		err = 0;
714  
715  		nfsd4_setup_layout_type(&exp);
716  	}
717  
718  	expp = svc_export_lookup(&exp);
719  	if (!expp) {
720  		err = -ENOMEM;
721  		goto out4;
722  	}
723  	expp = svc_export_update(&exp, expp);
724  	if (expp) {
725  		trace_nfsd_export_update(expp);
726  		cache_flush();
727  		exp_put(expp);
728  	} else
729  		err = -ENOMEM;
730  out4:
731  	nfsd4_fslocs_free(&exp.ex_fslocs);
732  	kfree(exp.ex_uuid);
733  out3:
734  	path_put(&exp.ex_path);
735  out1:
736  	auth_domain_put(dom);
737  out:
738  	kfree(buf);
739  	return err;
740  }
741  
742  static void exp_flags(struct seq_file *m, int flag, int fsid,
743  		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
744  static void show_secinfo(struct seq_file *m, struct svc_export *exp);
745  
746  static int is_export_stats_file(struct seq_file *m)
747  {
748  	/*
749  	 * The export_stats file uses the same ops as the exports file.
750  	 * We use the file's name to determine the reported info per export.
751  	 * There is no rename in nsfdfs, so d_name.name is stable.
752  	 */
753  	return !strcmp(m->file->f_path.dentry->d_name.name, "export_stats");
754  }
755  
756  static int svc_export_show(struct seq_file *m,
757  			   struct cache_detail *cd,
758  			   struct cache_head *h)
759  {
760  	struct svc_export *exp;
761  	bool export_stats = is_export_stats_file(m);
762  
763  	if (h == NULL) {
764  		if (export_stats)
765  			seq_puts(m, "#path domain start-time\n#\tstats\n");
766  		else
767  			seq_puts(m, "#path domain(flags)\n");
768  		return 0;
769  	}
770  	exp = container_of(h, struct svc_export, h);
771  	seq_path(m, &exp->ex_path, " \t\n\\");
772  	seq_putc(m, '\t');
773  	seq_escape(m, exp->ex_client->name, " \t\n\\");
774  	if (export_stats) {
775  		struct percpu_counter *counter = exp->ex_stats->counter;
776  
777  		seq_printf(m, "\t%lld\n", exp->ex_stats->start_time);
778  		seq_printf(m, "\tfh_stale: %lld\n",
779  			   percpu_counter_sum_positive(&counter[EXP_STATS_FH_STALE]));
780  		seq_printf(m, "\tio_read: %lld\n",
781  			   percpu_counter_sum_positive(&counter[EXP_STATS_IO_READ]));
782  		seq_printf(m, "\tio_write: %lld\n",
783  			   percpu_counter_sum_positive(&counter[EXP_STATS_IO_WRITE]));
784  		seq_putc(m, '\n');
785  		return 0;
786  	}
787  	seq_putc(m, '(');
788  	if (test_bit(CACHE_VALID, &h->flags) &&
789  	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
790  		exp_flags(m, exp->ex_flags, exp->ex_fsid,
791  			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
792  		if (exp->ex_uuid) {
793  			int i;
794  			seq_puts(m, ",uuid=");
795  			for (i = 0; i < EX_UUID_LEN; i++) {
796  				if ((i&3) == 0 && i)
797  					seq_putc(m, ':');
798  				seq_printf(m, "%02x", exp->ex_uuid[i]);
799  			}
800  		}
801  		show_secinfo(m, exp);
802  	}
803  	seq_puts(m, ")\n");
804  	return 0;
805  }
806  static int svc_export_match(struct cache_head *a, struct cache_head *b)
807  {
808  	struct svc_export *orig = container_of(a, struct svc_export, h);
809  	struct svc_export *new = container_of(b, struct svc_export, h);
810  	return orig->ex_client == new->ex_client &&
811  		path_equal(&orig->ex_path, &new->ex_path);
812  }
813  
814  static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
815  {
816  	struct svc_export *new = container_of(cnew, struct svc_export, h);
817  	struct svc_export *item = container_of(citem, struct svc_export, h);
818  
819  	kref_get(&item->ex_client->ref);
820  	new->ex_client = item->ex_client;
821  	new->ex_path = item->ex_path;
822  	path_get(&item->ex_path);
823  	new->ex_fslocs.locations = NULL;
824  	new->ex_fslocs.locations_count = 0;
825  	new->ex_fslocs.migrated = 0;
826  	new->ex_layout_types = 0;
827  	new->ex_uuid = NULL;
828  	new->cd = item->cd;
829  	export_stats_reset(new->ex_stats);
830  }
831  
832  static void export_update(struct cache_head *cnew, struct cache_head *citem)
833  {
834  	struct svc_export *new = container_of(cnew, struct svc_export, h);
835  	struct svc_export *item = container_of(citem, struct svc_export, h);
836  	int i;
837  
838  	new->ex_flags = item->ex_flags;
839  	new->ex_anon_uid = item->ex_anon_uid;
840  	new->ex_anon_gid = item->ex_anon_gid;
841  	new->ex_fsid = item->ex_fsid;
842  	new->ex_devid_map = item->ex_devid_map;
843  	item->ex_devid_map = NULL;
844  	new->ex_uuid = item->ex_uuid;
845  	item->ex_uuid = NULL;
846  	new->ex_fslocs.locations = item->ex_fslocs.locations;
847  	item->ex_fslocs.locations = NULL;
848  	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
849  	item->ex_fslocs.locations_count = 0;
850  	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
851  	item->ex_fslocs.migrated = 0;
852  	new->ex_layout_types = item->ex_layout_types;
853  	new->ex_nflavors = item->ex_nflavors;
854  	for (i = 0; i < MAX_SECINFO_LIST; i++) {
855  		new->ex_flavors[i] = item->ex_flavors[i];
856  	}
857  	new->ex_xprtsec_modes = item->ex_xprtsec_modes;
858  }
859  
860  static struct cache_head *svc_export_alloc(void)
861  {
862  	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
863  	if (!i)
864  		return NULL;
865  
866  	i->ex_stats = kmalloc(sizeof(*(i->ex_stats)), GFP_KERNEL);
867  	if (!i->ex_stats) {
868  		kfree(i);
869  		return NULL;
870  	}
871  
872  	if (export_stats_init(i->ex_stats)) {
873  		kfree(i->ex_stats);
874  		kfree(i);
875  		return NULL;
876  	}
877  
878  	return &i->h;
879  }
880  
881  static const struct cache_detail svc_export_cache_template = {
882  	.owner		= THIS_MODULE,
883  	.hash_size	= EXPORT_HASHMAX,
884  	.name		= "nfsd.export",
885  	.cache_put	= svc_export_put,
886  	.cache_upcall	= svc_export_upcall,
887  	.cache_request	= svc_export_request,
888  	.cache_parse	= svc_export_parse,
889  	.cache_show	= svc_export_show,
890  	.match		= svc_export_match,
891  	.init		= svc_export_init,
892  	.update		= export_update,
893  	.alloc		= svc_export_alloc,
894  };
895  
896  static int
897  svc_export_hash(struct svc_export *exp)
898  {
899  	int hash;
900  
901  	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
902  	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
903  	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
904  	return hash;
905  }
906  
907  static struct svc_export *
908  svc_export_lookup(struct svc_export *exp)
909  {
910  	struct cache_head *ch;
911  	int hash = svc_export_hash(exp);
912  
913  	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
914  	if (ch)
915  		return container_of(ch, struct svc_export, h);
916  	else
917  		return NULL;
918  }
919  
920  static struct svc_export *
921  svc_export_update(struct svc_export *new, struct svc_export *old)
922  {
923  	struct cache_head *ch;
924  	int hash = svc_export_hash(old);
925  
926  	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
927  	if (ch)
928  		return container_of(ch, struct svc_export, h);
929  	else
930  		return NULL;
931  }
932  
933  
934  static struct svc_expkey *
935  exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
936  	     u32 *fsidv, struct cache_req *reqp)
937  {
938  	struct svc_expkey key, *ek;
939  	int err;
940  
941  	if (!clp)
942  		return ERR_PTR(-ENOENT);
943  
944  	key.ek_client = clp;
945  	key.ek_fsidtype = fsid_type;
946  	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
947  
948  	ek = svc_expkey_lookup(cd, &key);
949  	if (ek == NULL)
950  		return ERR_PTR(-ENOMEM);
951  	err = cache_check(cd, &ek->h, reqp);
952  	if (err) {
953  		trace_nfsd_exp_find_key(&key, err);
954  		return ERR_PTR(err);
955  	}
956  	return ek;
957  }
958  
959  static struct svc_export *
960  exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
961  		const struct path *path, struct cache_req *reqp)
962  {
963  	struct svc_export *exp, key;
964  	int err;
965  
966  	if (!clp)
967  		return ERR_PTR(-ENOENT);
968  
969  	key.ex_client = clp;
970  	key.ex_path = *path;
971  	key.cd = cd;
972  
973  	exp = svc_export_lookup(&key);
974  	if (exp == NULL)
975  		return ERR_PTR(-ENOMEM);
976  	err = cache_check(cd, &exp->h, reqp);
977  	if (err) {
978  		trace_nfsd_exp_get_by_name(&key, err);
979  		return ERR_PTR(err);
980  	}
981  	return exp;
982  }
983  
984  /*
985   * Find the export entry for a given dentry.
986   */
987  static struct svc_export *
988  exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
989  {
990  	struct dentry *saved = dget(path->dentry);
991  	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
992  
993  	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
994  		struct dentry *parent = dget_parent(path->dentry);
995  		dput(path->dentry);
996  		path->dentry = parent;
997  		exp = exp_get_by_name(cd, clp, path, NULL);
998  	}
999  	dput(path->dentry);
1000  	path->dentry = saved;
1001  	return exp;
1002  }
1003  
1004  
1005  
1006  /*
1007   * Obtain the root fh on behalf of a client.
1008   * This could be done in user space, but I feel that it adds some safety
1009   * since its harder to fool a kernel module than a user space program.
1010   */
1011  int
1012  exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
1013  	   struct knfsd_fh *f, int maxsize)
1014  {
1015  	struct svc_export	*exp;
1016  	struct path		path;
1017  	struct inode		*inode;
1018  	struct svc_fh		fh;
1019  	int			err;
1020  	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
1021  	struct cache_detail	*cd = nn->svc_export_cache;
1022  
1023  	err = -EPERM;
1024  	/* NB: we probably ought to check that it's NUL-terminated */
1025  	if (kern_path(name, 0, &path)) {
1026  		printk("nfsd: exp_rootfh path not found %s", name);
1027  		return err;
1028  	}
1029  	inode = d_inode(path.dentry);
1030  
1031  	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
1032  		 name, path.dentry, clp->name,
1033  		 inode->i_sb->s_id, inode->i_ino);
1034  	exp = exp_parent(cd, clp, &path);
1035  	if (IS_ERR(exp)) {
1036  		err = PTR_ERR(exp);
1037  		goto out;
1038  	}
1039  
1040  	/*
1041  	 * fh must be initialized before calling fh_compose
1042  	 */
1043  	fh_init(&fh, maxsize);
1044  	if (fh_compose(&fh, exp, path.dentry, NULL))
1045  		err = -EINVAL;
1046  	else
1047  		err = 0;
1048  	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
1049  	fh_put(&fh);
1050  	exp_put(exp);
1051  out:
1052  	path_put(&path);
1053  	return err;
1054  }
1055  
1056  static struct svc_export *exp_find(struct cache_detail *cd,
1057  				   struct auth_domain *clp, int fsid_type,
1058  				   u32 *fsidv, struct cache_req *reqp)
1059  {
1060  	struct svc_export *exp;
1061  	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
1062  	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
1063  	if (IS_ERR(ek))
1064  		return ERR_CAST(ek);
1065  
1066  	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
1067  	cache_put(&ek->h, nn->svc_expkey_cache);
1068  
1069  	if (IS_ERR(exp))
1070  		return ERR_CAST(exp);
1071  	return exp;
1072  }
1073  
1074  __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
1075  {
1076  	struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
1077  	struct svc_xprt *xprt = rqstp->rq_xprt;
1078  
1079  	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) {
1080  		if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags))
1081  			goto ok;
1082  	}
1083  	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) {
1084  		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
1085  		    !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
1086  			goto ok;
1087  	}
1088  	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) {
1089  		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
1090  		    test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
1091  			goto ok;
1092  	}
1093  	goto denied;
1094  
1095  ok:
1096  	/* legacy gss-only clients are always OK: */
1097  	if (exp->ex_client == rqstp->rq_gssclient)
1098  		return 0;
1099  	/* ip-address based client; check sec= export option: */
1100  	for (f = exp->ex_flavors; f < end; f++) {
1101  		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
1102  			return 0;
1103  	}
1104  	/* defaults in absence of sec= options: */
1105  	if (exp->ex_nflavors == 0) {
1106  		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
1107  		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
1108  			return 0;
1109  	}
1110  
1111  	/* If the compound op contains a spo_must_allowed op,
1112  	 * it will be sent with integrity/protection which
1113  	 * will have to be expressly allowed on mounts that
1114  	 * don't support it
1115  	 */
1116  
1117  	if (nfsd4_spo_must_allow(rqstp))
1118  		return 0;
1119  
1120  denied:
1121  	return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec;
1122  }
1123  
1124  /*
1125   * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
1126   * auth_unix client) if it's available and has secinfo information;
1127   * otherwise, will try to use rq_gssclient.
1128   *
1129   * Called from functions that handle requests; functions that do work on
1130   * behalf of mountd are passed a single client name to use, and should
1131   * use exp_get_by_name() or exp_find().
1132   */
1133  struct svc_export *
1134  rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
1135  {
1136  	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1137  	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1138  	struct cache_detail *cd = nn->svc_export_cache;
1139  
1140  	if (rqstp->rq_client == NULL)
1141  		goto gss;
1142  
1143  	/* First try the auth_unix client: */
1144  	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
1145  	if (PTR_ERR(exp) == -ENOENT)
1146  		goto gss;
1147  	if (IS_ERR(exp))
1148  		return exp;
1149  	/* If it has secinfo, assume there are no gss/... clients */
1150  	if (exp->ex_nflavors > 0)
1151  		return exp;
1152  gss:
1153  	/* Otherwise, try falling back on gss client */
1154  	if (rqstp->rq_gssclient == NULL)
1155  		return exp;
1156  	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1157  	if (PTR_ERR(gssexp) == -ENOENT)
1158  		return exp;
1159  	if (!IS_ERR(exp))
1160  		exp_put(exp);
1161  	return gssexp;
1162  }
1163  
1164  struct svc_export *
1165  rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1166  {
1167  	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1168  	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1169  	struct cache_detail *cd = nn->svc_export_cache;
1170  
1171  	if (rqstp->rq_client == NULL)
1172  		goto gss;
1173  
1174  	/* First try the auth_unix client: */
1175  	exp = exp_find(cd, rqstp->rq_client, fsid_type,
1176  		       fsidv, &rqstp->rq_chandle);
1177  	if (PTR_ERR(exp) == -ENOENT)
1178  		goto gss;
1179  	if (IS_ERR(exp))
1180  		return exp;
1181  	/* If it has secinfo, assume there are no gss/... clients */
1182  	if (exp->ex_nflavors > 0)
1183  		return exp;
1184  gss:
1185  	/* Otherwise, try falling back on gss client */
1186  	if (rqstp->rq_gssclient == NULL)
1187  		return exp;
1188  	gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1189  						&rqstp->rq_chandle);
1190  	if (PTR_ERR(gssexp) == -ENOENT)
1191  		return exp;
1192  	if (!IS_ERR(exp))
1193  		exp_put(exp);
1194  	return gssexp;
1195  }
1196  
1197  struct svc_export *
1198  rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1199  {
1200  	struct dentry *saved = dget(path->dentry);
1201  	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1202  
1203  	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1204  		struct dentry *parent = dget_parent(path->dentry);
1205  		dput(path->dentry);
1206  		path->dentry = parent;
1207  		exp = rqst_exp_get_by_name(rqstp, path);
1208  	}
1209  	dput(path->dentry);
1210  	path->dentry = saved;
1211  	return exp;
1212  }
1213  
1214  struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1215  {
1216  	u32 fsidv[2];
1217  
1218  	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1219  
1220  	return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1221  }
1222  
1223  /*
1224   * Called when we need the filehandle for the root of the pseudofs,
1225   * for a given NFSv4 client.   The root is defined to be the
1226   * export point with fsid==0
1227   */
1228  __be32
1229  exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1230  {
1231  	struct svc_export *exp;
1232  	__be32 rv;
1233  
1234  	exp = rqst_find_fsidzero_export(rqstp);
1235  	if (IS_ERR(exp))
1236  		return nfserrno(PTR_ERR(exp));
1237  	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1238  	exp_put(exp);
1239  	return rv;
1240  }
1241  
1242  static struct flags {
1243  	int flag;
1244  	char *name[2];
1245  } expflags[] = {
1246  	{ NFSEXP_READONLY, {"ro", "rw"}},
1247  	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
1248  	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1249  	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
1250  	{ NFSEXP_ASYNC, {"async", "sync"}},
1251  	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1252  	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1253  	{ NFSEXP_NOHIDE, {"nohide", ""}},
1254  	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1255  	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1256  	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1257  	{ NFSEXP_V4ROOT, {"v4root", ""}},
1258  	{ NFSEXP_PNFS, {"pnfs", ""}},
1259  	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1260  	{ 0, {"", ""}}
1261  };
1262  
1263  static void show_expflags(struct seq_file *m, int flags, int mask)
1264  {
1265  	struct flags *flg;
1266  	int state, first = 0;
1267  
1268  	for (flg = expflags; flg->flag; flg++) {
1269  		if (flg->flag & ~mask)
1270  			continue;
1271  		state = (flg->flag & flags) ? 0 : 1;
1272  		if (*flg->name[state])
1273  			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1274  	}
1275  }
1276  
1277  static void show_secinfo_flags(struct seq_file *m, int flags)
1278  {
1279  	seq_printf(m, ",");
1280  	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1281  }
1282  
1283  static bool secinfo_flags_equal(int f, int g)
1284  {
1285  	f &= NFSEXP_SECINFO_FLAGS;
1286  	g &= NFSEXP_SECINFO_FLAGS;
1287  	return f == g;
1288  }
1289  
1290  static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1291  {
1292  	int flags;
1293  
1294  	flags = (*fp)->flags;
1295  	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1296  	(*fp)++;
1297  	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1298  		seq_printf(m, ":%d", (*fp)->pseudoflavor);
1299  		(*fp)++;
1300  	}
1301  	return flags;
1302  }
1303  
1304  static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1305  {
1306  	struct exp_flavor_info *f;
1307  	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1308  	int flags;
1309  
1310  	if (exp->ex_nflavors == 0)
1311  		return;
1312  	f = exp->ex_flavors;
1313  	flags = show_secinfo_run(m, &f, end);
1314  	if (!secinfo_flags_equal(flags, exp->ex_flags))
1315  		show_secinfo_flags(m, flags);
1316  	while (f != end) {
1317  		flags = show_secinfo_run(m, &f, end);
1318  		show_secinfo_flags(m, flags);
1319  	}
1320  }
1321  
1322  static void exp_flags(struct seq_file *m, int flag, int fsid,
1323  		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1324  {
1325  	struct user_namespace *userns = m->file->f_cred->user_ns;
1326  
1327  	show_expflags(m, flag, NFSEXP_ALLFLAGS);
1328  	if (flag & NFSEXP_FSID)
1329  		seq_printf(m, ",fsid=%d", fsid);
1330  	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
1331  	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
1332  		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
1333  	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
1334  	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
1335  		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
1336  	if (fsloc && fsloc->locations_count > 0) {
1337  		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1338  		int i;
1339  
1340  		seq_printf(m, ",%s=", loctype);
1341  		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1342  		seq_putc(m, '@');
1343  		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1344  		for (i = 1; i < fsloc->locations_count; i++) {
1345  			seq_putc(m, ';');
1346  			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1347  			seq_putc(m, '@');
1348  			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1349  		}
1350  	}
1351  }
1352  
1353  static int e_show(struct seq_file *m, void *p)
1354  {
1355  	struct cache_head *cp = p;
1356  	struct svc_export *exp = container_of(cp, struct svc_export, h);
1357  	struct cache_detail *cd = m->private;
1358  	bool export_stats = is_export_stats_file(m);
1359  
1360  	if (p == SEQ_START_TOKEN) {
1361  		seq_puts(m, "# Version 1.1\n");
1362  		if (export_stats)
1363  			seq_puts(m, "# Path Client Start-time\n#\tStats\n");
1364  		else
1365  			seq_puts(m, "# Path Client(Flags) # IPs\n");
1366  		return 0;
1367  	}
1368  
1369  	exp_get(exp);
1370  	if (cache_check(cd, &exp->h, NULL))
1371  		return 0;
1372  	exp_put(exp);
1373  	return svc_export_show(m, cd, cp);
1374  }
1375  
1376  const struct seq_operations nfs_exports_op = {
1377  	.start	= cache_seq_start_rcu,
1378  	.next	= cache_seq_next_rcu,
1379  	.stop	= cache_seq_stop_rcu,
1380  	.show	= e_show,
1381  };
1382  
1383  /*
1384   * Initialize the exports module.
1385   */
1386  int
1387  nfsd_export_init(struct net *net)
1388  {
1389  	int rv;
1390  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1391  
1392  	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1393  
1394  	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1395  	if (IS_ERR(nn->svc_export_cache))
1396  		return PTR_ERR(nn->svc_export_cache);
1397  	rv = cache_register_net(nn->svc_export_cache, net);
1398  	if (rv)
1399  		goto destroy_export_cache;
1400  
1401  	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1402  	if (IS_ERR(nn->svc_expkey_cache)) {
1403  		rv = PTR_ERR(nn->svc_expkey_cache);
1404  		goto unregister_export_cache;
1405  	}
1406  	rv = cache_register_net(nn->svc_expkey_cache, net);
1407  	if (rv)
1408  		goto destroy_expkey_cache;
1409  	return 0;
1410  
1411  destroy_expkey_cache:
1412  	cache_destroy_net(nn->svc_expkey_cache, net);
1413  unregister_export_cache:
1414  	cache_unregister_net(nn->svc_export_cache, net);
1415  destroy_export_cache:
1416  	cache_destroy_net(nn->svc_export_cache, net);
1417  	return rv;
1418  }
1419  
1420  /*
1421   * Flush exports table - called when last nfsd thread is killed
1422   */
1423  void
1424  nfsd_export_flush(struct net *net)
1425  {
1426  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1427  
1428  	cache_purge(nn->svc_expkey_cache);
1429  	cache_purge(nn->svc_export_cache);
1430  }
1431  
1432  /*
1433   * Shutdown the exports module.
1434   */
1435  void
1436  nfsd_export_shutdown(struct net *net)
1437  {
1438  	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1439  
1440  	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1441  
1442  	cache_unregister_net(nn->svc_expkey_cache, net);
1443  	cache_unregister_net(nn->svc_export_cache, net);
1444  	cache_destroy_net(nn->svc_expkey_cache, net);
1445  	cache_destroy_net(nn->svc_export_cache, net);
1446  	svcauth_unix_purge(net);
1447  
1448  	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1449  }
1450