xref: /linux/fs/nfsd/nfs4recover.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1 /*
2 *  Copyright (c) 2004 The Regents of the University of Michigan.
3 *  Copyright (c) 2012 Jeff Layton <jlayton@redhat.com>
4 *  All rights reserved.
5 *
6 *  Andy Adamson <andros@citi.umich.edu>
7 *
8 *  Redistribution and use in source and binary forms, with or without
9 *  modification, are permitted provided that the following conditions
10 *  are met:
11 *
12 *  1. Redistributions of source code must retain the above copyright
13 *     notice, this list of conditions and the following disclaimer.
14 *  2. Redistributions in binary form must reproduce the above copyright
15 *     notice, this list of conditions and the following disclaimer in the
16 *     documentation and/or other materials provided with the distribution.
17 *  3. Neither the name of the University nor the names of its
18 *     contributors may be used to endorse or promote products derived
19 *     from this software without specific prior written permission.
20 *
21 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 */
34 
35 #include <crypto/hash.h>
36 #include <linux/file.h>
37 #include <linux/slab.h>
38 #include <linux/namei.h>
39 #include <linux/sched.h>
40 #include <linux/fs.h>
41 #include <linux/module.h>
42 #include <net/net_namespace.h>
43 #include <linux/sunrpc/rpc_pipe_fs.h>
44 #include <linux/sunrpc/clnt.h>
45 #include <linux/nfsd/cld.h>
46 
47 #include "nfsd.h"
48 #include "state.h"
49 #include "vfs.h"
50 #include "netns.h"
51 
52 #define NFSDDBG_FACILITY                NFSDDBG_PROC
53 
54 /* Declarations */
55 struct nfsd4_client_tracking_ops {
56 	int (*init)(struct net *);
57 	void (*exit)(struct net *);
58 	void (*create)(struct nfs4_client *);
59 	void (*remove)(struct nfs4_client *);
60 	int (*check)(struct nfs4_client *);
61 	void (*grace_done)(struct nfsd_net *);
62 	uint8_t version;
63 	size_t msglen;
64 };
65 
66 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
67 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2;
68 
69 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
70 /* Globals */
71 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
72 
73 static int
74 nfs4_save_creds(const struct cred **original_creds)
75 {
76 	struct cred *new;
77 
78 	new = prepare_creds();
79 	if (!new)
80 		return -ENOMEM;
81 
82 	new->fsuid = GLOBAL_ROOT_UID;
83 	new->fsgid = GLOBAL_ROOT_GID;
84 	*original_creds = override_creds(new);
85 	put_cred(new);
86 	return 0;
87 }
88 
89 static void
90 nfs4_reset_creds(const struct cred *original)
91 {
92 	revert_creds(original);
93 }
94 
95 static void
96 md5_to_hex(char *out, char *md5)
97 {
98 	int i;
99 
100 	for (i=0; i<16; i++) {
101 		unsigned char c = md5[i];
102 
103 		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
104 		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
105 	}
106 	*out = '\0';
107 }
108 
109 static int
110 nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
111 {
112 	struct xdr_netobj cksum;
113 	struct crypto_shash *tfm;
114 	int status;
115 
116 	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
117 			clname->len, clname->data);
118 	tfm = crypto_alloc_shash("md5", 0, 0);
119 	if (IS_ERR(tfm)) {
120 		status = PTR_ERR(tfm);
121 		goto out_no_tfm;
122 	}
123 
124 	cksum.len = crypto_shash_digestsize(tfm);
125 	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
126 	if (cksum.data == NULL) {
127 		status = -ENOMEM;
128  		goto out;
129 	}
130 
131 	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
132 					 cksum.data);
133 	if (status)
134 		goto out;
135 
136 	md5_to_hex(dname, cksum.data);
137 
138 	status = 0;
139 out:
140 	kfree(cksum.data);
141 	crypto_free_shash(tfm);
142 out_no_tfm:
143 	return status;
144 }
145 
146 /*
147  * If we had an error generating the recdir name for the legacy tracker
148  * then warn the admin. If the error doesn't appear to be transient,
149  * then disable recovery tracking.
150  */
151 static void
152 legacy_recdir_name_error(struct nfs4_client *clp, int error)
153 {
154 	printk(KERN_ERR "NFSD: unable to generate recoverydir "
155 			"name (%d).\n", error);
156 
157 	/*
158 	 * if the algorithm just doesn't exist, then disable the recovery
159 	 * tracker altogether. The crypto libs will generally return this if
160 	 * FIPS is enabled as well.
161 	 */
162 	if (error == -ENOENT) {
163 		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
164 			"Reboot recovery will not function correctly!\n");
165 		nfsd4_client_tracking_exit(clp->net);
166 	}
167 }
168 
169 static void
170 __nfsd4_create_reclaim_record_grace(struct nfs4_client *clp,
171 		const char *dname, int len, struct nfsd_net *nn)
172 {
173 	struct xdr_netobj name;
174 	struct xdr_netobj princhash = { .len = 0, .data = NULL };
175 	struct nfs4_client_reclaim *crp;
176 
177 	name.data = kmemdup(dname, len, GFP_KERNEL);
178 	if (!name.data) {
179 		dprintk("%s: failed to allocate memory for name.data!\n",
180 			__func__);
181 		return;
182 	}
183 	name.len = len;
184 	crp = nfs4_client_to_reclaim(name, princhash, nn);
185 	if (!crp) {
186 		kfree(name.data);
187 		return;
188 	}
189 	crp->cr_clp = clp;
190 }
191 
192 static void
193 nfsd4_create_clid_dir(struct nfs4_client *clp)
194 {
195 	const struct cred *original_cred;
196 	char dname[HEXDIR_LEN];
197 	struct dentry *dir, *dentry;
198 	int status;
199 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
200 
201 	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
202 		return;
203 	if (!nn->rec_file)
204 		return;
205 
206 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
207 	if (status)
208 		return legacy_recdir_name_error(clp, status);
209 
210 	status = nfs4_save_creds(&original_cred);
211 	if (status < 0)
212 		return;
213 
214 	status = mnt_want_write_file(nn->rec_file);
215 	if (status)
216 		goto out_creds;
217 
218 	dir = nn->rec_file->f_path.dentry;
219 	/* lock the parent */
220 	inode_lock(d_inode(dir));
221 
222 	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
223 	if (IS_ERR(dentry)) {
224 		status = PTR_ERR(dentry);
225 		goto out_unlock;
226 	}
227 	if (d_really_is_positive(dentry))
228 		/*
229 		 * In the 4.1 case, where we're called from
230 		 * reclaim_complete(), records from the previous reboot
231 		 * may still be left, so this is OK.
232 		 *
233 		 * In the 4.0 case, we should never get here; but we may
234 		 * as well be forgiving and just succeed silently.
235 		 */
236 		goto out_put;
237 	status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
238 out_put:
239 	dput(dentry);
240 out_unlock:
241 	inode_unlock(d_inode(dir));
242 	if (status == 0) {
243 		if (nn->in_grace)
244 			__nfsd4_create_reclaim_record_grace(clp, dname,
245 					HEXDIR_LEN, nn);
246 		vfs_fsync(nn->rec_file, 0);
247 	} else {
248 		printk(KERN_ERR "NFSD: failed to write recovery record"
249 				" (err %d); please check that %s exists"
250 				" and is writeable", status,
251 				user_recovery_dirname);
252 	}
253 	mnt_drop_write_file(nn->rec_file);
254 out_creds:
255 	nfs4_reset_creds(original_cred);
256 }
257 
258 typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
259 
260 struct name_list {
261 	char name[HEXDIR_LEN];
262 	struct list_head list;
263 };
264 
265 struct nfs4_dir_ctx {
266 	struct dir_context ctx;
267 	struct list_head names;
268 };
269 
270 static bool
271 nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
272 		loff_t offset, u64 ino, unsigned int d_type)
273 {
274 	struct nfs4_dir_ctx *ctx =
275 		container_of(__ctx, struct nfs4_dir_ctx, ctx);
276 	struct name_list *entry;
277 
278 	if (namlen != HEXDIR_LEN - 1)
279 		return true;
280 	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
281 	if (entry == NULL)
282 		return false;
283 	memcpy(entry->name, name, HEXDIR_LEN - 1);
284 	entry->name[HEXDIR_LEN - 1] = '\0';
285 	list_add(&entry->list, &ctx->names);
286 	return true;
287 }
288 
289 static int
290 nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
291 {
292 	const struct cred *original_cred;
293 	struct dentry *dir = nn->rec_file->f_path.dentry;
294 	struct nfs4_dir_ctx ctx = {
295 		.ctx.actor = nfsd4_build_namelist,
296 		.names = LIST_HEAD_INIT(ctx.names)
297 	};
298 	struct name_list *entry, *tmp;
299 	int status;
300 
301 	status = nfs4_save_creds(&original_cred);
302 	if (status < 0)
303 		return status;
304 
305 	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
306 	if (status < 0) {
307 		nfs4_reset_creds(original_cred);
308 		return status;
309 	}
310 
311 	status = iterate_dir(nn->rec_file, &ctx.ctx);
312 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
313 
314 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
315 		if (!status) {
316 			struct dentry *dentry;
317 			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
318 			if (IS_ERR(dentry)) {
319 				status = PTR_ERR(dentry);
320 				break;
321 			}
322 			status = f(dir, dentry, nn);
323 			dput(dentry);
324 		}
325 		list_del(&entry->list);
326 		kfree(entry);
327 	}
328 	inode_unlock(d_inode(dir));
329 	nfs4_reset_creds(original_cred);
330 
331 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
332 		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
333 		list_del(&entry->list);
334 		kfree(entry);
335 	}
336 	return status;
337 }
338 
339 static int
340 nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
341 {
342 	struct dentry *dir, *dentry;
343 	int status;
344 
345 	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
346 
347 	dir = nn->rec_file->f_path.dentry;
348 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
349 	dentry = lookup_one_len(name, dir, namlen);
350 	if (IS_ERR(dentry)) {
351 		status = PTR_ERR(dentry);
352 		goto out_unlock;
353 	}
354 	status = -ENOENT;
355 	if (d_really_is_negative(dentry))
356 		goto out;
357 	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry);
358 out:
359 	dput(dentry);
360 out_unlock:
361 	inode_unlock(d_inode(dir));
362 	return status;
363 }
364 
365 static void
366 __nfsd4_remove_reclaim_record_grace(const char *dname, int len,
367 		struct nfsd_net *nn)
368 {
369 	struct xdr_netobj name;
370 	struct nfs4_client_reclaim *crp;
371 
372 	name.data = kmemdup(dname, len, GFP_KERNEL);
373 	if (!name.data) {
374 		dprintk("%s: failed to allocate memory for name.data!\n",
375 			__func__);
376 		return;
377 	}
378 	name.len = len;
379 	crp = nfsd4_find_reclaim_client(name, nn);
380 	kfree(name.data);
381 	if (crp)
382 		nfs4_remove_reclaim_record(crp, nn);
383 }
384 
385 static void
386 nfsd4_remove_clid_dir(struct nfs4_client *clp)
387 {
388 	const struct cred *original_cred;
389 	char dname[HEXDIR_LEN];
390 	int status;
391 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
392 
393 	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
394 		return;
395 
396 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
397 	if (status)
398 		return legacy_recdir_name_error(clp, status);
399 
400 	status = mnt_want_write_file(nn->rec_file);
401 	if (status)
402 		goto out;
403 	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
404 
405 	status = nfs4_save_creds(&original_cred);
406 	if (status < 0)
407 		goto out_drop_write;
408 
409 	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
410 	nfs4_reset_creds(original_cred);
411 	if (status == 0) {
412 		vfs_fsync(nn->rec_file, 0);
413 		if (nn->in_grace)
414 			__nfsd4_remove_reclaim_record_grace(dname,
415 					HEXDIR_LEN, nn);
416 	}
417 out_drop_write:
418 	mnt_drop_write_file(nn->rec_file);
419 out:
420 	if (status)
421 		printk("NFSD: Failed to remove expired client state directory"
422 				" %.*s\n", HEXDIR_LEN, dname);
423 }
424 
425 static int
426 purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
427 {
428 	int status;
429 	struct xdr_netobj name;
430 
431 	if (child->d_name.len != HEXDIR_LEN - 1) {
432 		printk("%s: illegal name %pd in recovery directory\n",
433 				__func__, child);
434 		/* Keep trying; maybe the others are OK: */
435 		return 0;
436 	}
437 	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
438 	if (!name.data) {
439 		dprintk("%s: failed to allocate memory for name.data!\n",
440 			__func__);
441 		goto out;
442 	}
443 	name.len = HEXDIR_LEN;
444 	if (nfs4_has_reclaimed_state(name, nn))
445 		goto out_free;
446 
447 	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
448 	if (status)
449 		printk("failed to remove client recovery directory %pd\n",
450 				child);
451 out_free:
452 	kfree(name.data);
453 out:
454 	/* Keep trying, success or failure: */
455 	return 0;
456 }
457 
458 static void
459 nfsd4_recdir_purge_old(struct nfsd_net *nn)
460 {
461 	int status;
462 
463 	nn->in_grace = false;
464 	if (!nn->rec_file)
465 		return;
466 	status = mnt_want_write_file(nn->rec_file);
467 	if (status)
468 		goto out;
469 	status = nfsd4_list_rec_dir(purge_old, nn);
470 	if (status == 0)
471 		vfs_fsync(nn->rec_file, 0);
472 	mnt_drop_write_file(nn->rec_file);
473 out:
474 	nfs4_release_reclaim(nn);
475 	if (status)
476 		printk("nfsd4: failed to purge old clients from recovery"
477 			" directory %pD\n", nn->rec_file);
478 }
479 
480 static int
481 load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
482 {
483 	struct xdr_netobj name;
484 	struct xdr_netobj princhash = { .len = 0, .data = NULL };
485 
486 	if (child->d_name.len != HEXDIR_LEN - 1) {
487 		printk("%s: illegal name %pd in recovery directory\n",
488 				__func__, child);
489 		/* Keep trying; maybe the others are OK: */
490 		return 0;
491 	}
492 	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
493 	if (!name.data) {
494 		dprintk("%s: failed to allocate memory for name.data!\n",
495 			__func__);
496 		goto out;
497 	}
498 	name.len = HEXDIR_LEN;
499 	if (!nfs4_client_to_reclaim(name, princhash, nn))
500 		kfree(name.data);
501 out:
502 	return 0;
503 }
504 
505 static int
506 nfsd4_recdir_load(struct net *net) {
507 	int status;
508 	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
509 
510 	if (!nn->rec_file)
511 		return 0;
512 
513 	status = nfsd4_list_rec_dir(load_recdir, nn);
514 	if (status)
515 		printk("nfsd4: failed loading clients from recovery"
516 			" directory %pD\n", nn->rec_file);
517 	return status;
518 }
519 
520 /*
521  * Hold reference to the recovery directory.
522  */
523 
524 static int
525 nfsd4_init_recdir(struct net *net)
526 {
527 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
528 	const struct cred *original_cred;
529 	int status;
530 
531 	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
532 			user_recovery_dirname);
533 
534 	BUG_ON(nn->rec_file);
535 
536 	status = nfs4_save_creds(&original_cred);
537 	if (status < 0) {
538 		printk("NFSD: Unable to change credentials to find recovery"
539 		       " directory: error %d\n",
540 		       status);
541 		return status;
542 	}
543 
544 	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
545 	if (IS_ERR(nn->rec_file)) {
546 		printk("NFSD: unable to find recovery directory %s\n",
547 				user_recovery_dirname);
548 		status = PTR_ERR(nn->rec_file);
549 		nn->rec_file = NULL;
550 	}
551 
552 	nfs4_reset_creds(original_cred);
553 	if (!status)
554 		nn->in_grace = true;
555 	return status;
556 }
557 
558 static void
559 nfsd4_shutdown_recdir(struct net *net)
560 {
561 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
562 
563 	if (!nn->rec_file)
564 		return;
565 	fput(nn->rec_file);
566 	nn->rec_file = NULL;
567 }
568 
569 static int
570 nfs4_legacy_state_init(struct net *net)
571 {
572 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
573 	int i;
574 
575 	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
576 						sizeof(struct list_head),
577 						GFP_KERNEL);
578 	if (!nn->reclaim_str_hashtbl)
579 		return -ENOMEM;
580 
581 	for (i = 0; i < CLIENT_HASH_SIZE; i++)
582 		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
583 	nn->reclaim_str_hashtbl_size = 0;
584 
585 	return 0;
586 }
587 
588 static void
589 nfs4_legacy_state_shutdown(struct net *net)
590 {
591 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
592 
593 	kfree(nn->reclaim_str_hashtbl);
594 }
595 
596 static int
597 nfsd4_load_reboot_recovery_data(struct net *net)
598 {
599 	int status;
600 
601 	status = nfsd4_init_recdir(net);
602 	if (status)
603 		return status;
604 
605 	status = nfsd4_recdir_load(net);
606 	if (status)
607 		nfsd4_shutdown_recdir(net);
608 
609 	return status;
610 }
611 
612 static int
613 nfsd4_legacy_tracking_init(struct net *net)
614 {
615 	int status;
616 
617 	/* XXX: The legacy code won't work in a container */
618 	if (net != &init_net) {
619 		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
620 		return -EINVAL;
621 	}
622 
623 	status = nfs4_legacy_state_init(net);
624 	if (status)
625 		return status;
626 
627 	status = nfsd4_load_reboot_recovery_data(net);
628 	if (status)
629 		goto err;
630 	pr_info("NFSD: Using legacy client tracking operations.\n");
631 	return 0;
632 
633 err:
634 	nfs4_legacy_state_shutdown(net);
635 	return status;
636 }
637 
638 static void
639 nfsd4_legacy_tracking_exit(struct net *net)
640 {
641 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
642 
643 	nfs4_release_reclaim(nn);
644 	nfsd4_shutdown_recdir(net);
645 	nfs4_legacy_state_shutdown(net);
646 }
647 
648 /*
649  * Change the NFSv4 recovery directory to recdir.
650  */
651 int
652 nfs4_reset_recoverydir(char *recdir)
653 {
654 	int status;
655 	struct path path;
656 
657 	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
658 	if (status)
659 		return status;
660 	status = -ENOTDIR;
661 	if (d_is_dir(path.dentry)) {
662 		strcpy(user_recovery_dirname, recdir);
663 		status = 0;
664 	}
665 	path_put(&path);
666 	return status;
667 }
668 
669 char *
670 nfs4_recoverydir(void)
671 {
672 	return user_recovery_dirname;
673 }
674 
675 static int
676 nfsd4_check_legacy_client(struct nfs4_client *clp)
677 {
678 	int status;
679 	char dname[HEXDIR_LEN];
680 	struct nfs4_client_reclaim *crp;
681 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
682 	struct xdr_netobj name;
683 
684 	/* did we already find that this client is stable? */
685 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
686 		return 0;
687 
688 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
689 	if (status) {
690 		legacy_recdir_name_error(clp, status);
691 		return status;
692 	}
693 
694 	/* look for it in the reclaim hashtable otherwise */
695 	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
696 	if (!name.data) {
697 		dprintk("%s: failed to allocate memory for name.data!\n",
698 			__func__);
699 		goto out_enoent;
700 	}
701 	name.len = HEXDIR_LEN;
702 	crp = nfsd4_find_reclaim_client(name, nn);
703 	kfree(name.data);
704 	if (crp) {
705 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
706 		crp->cr_clp = clp;
707 		return 0;
708 	}
709 
710 out_enoent:
711 	return -ENOENT;
712 }
713 
714 static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
715 	.init		= nfsd4_legacy_tracking_init,
716 	.exit		= nfsd4_legacy_tracking_exit,
717 	.create		= nfsd4_create_clid_dir,
718 	.remove		= nfsd4_remove_clid_dir,
719 	.check		= nfsd4_check_legacy_client,
720 	.grace_done	= nfsd4_recdir_purge_old,
721 	.version	= 1,
722 	.msglen		= 0,
723 };
724 #endif /* CONFIG_NFSD_LEGACY_CLIENT_TRACKING */
725 
726 /* Globals */
727 #define NFSD_PIPE_DIR		"nfsd"
728 #define NFSD_CLD_PIPE		"cld"
729 
730 /* per-net-ns structure for holding cld upcall info */
731 struct cld_net {
732 	struct rpc_pipe		*cn_pipe;
733 	spinlock_t		 cn_lock;
734 	struct list_head	 cn_list;
735 	unsigned int		 cn_xid;
736 	struct crypto_shash	*cn_tfm;
737 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
738 	bool			 cn_has_legacy;
739 #endif
740 };
741 
742 struct cld_upcall {
743 	struct list_head	 cu_list;
744 	struct cld_net		*cu_net;
745 	struct completion	 cu_done;
746 	union {
747 		struct cld_msg_hdr	 cu_hdr;
748 		struct cld_msg		 cu_msg;
749 		struct cld_msg_v2	 cu_msg_v2;
750 	} cu_u;
751 };
752 
753 static int
754 __cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
755 {
756 	int ret;
757 	struct rpc_pipe_msg msg;
758 	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
759 
760 	memset(&msg, 0, sizeof(msg));
761 	msg.data = cmsg;
762 	msg.len = nn->client_tracking_ops->msglen;
763 
764 	ret = rpc_queue_upcall(pipe, &msg);
765 	if (ret < 0) {
766 		goto out;
767 	}
768 
769 	wait_for_completion(&cup->cu_done);
770 
771 	if (msg.errno < 0)
772 		ret = msg.errno;
773 out:
774 	return ret;
775 }
776 
777 static int
778 cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
779 {
780 	int ret;
781 
782 	/*
783 	 * -EAGAIN occurs when pipe is closed and reopened while there are
784 	 *  upcalls queued.
785 	 */
786 	do {
787 		ret = __cld_pipe_upcall(pipe, cmsg, nn);
788 	} while (ret == -EAGAIN);
789 
790 	return ret;
791 }
792 
793 static ssize_t
794 __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
795 		struct nfsd_net *nn)
796 {
797 	uint8_t cmd, princhashlen;
798 	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
799 	uint16_t namelen;
800 
801 	if (get_user(cmd, &cmsg->cm_cmd)) {
802 		dprintk("%s: error when copying cmd from userspace", __func__);
803 		return -EFAULT;
804 	}
805 	if (cmd == Cld_GraceStart) {
806 		if (nn->client_tracking_ops->version >= 2) {
807 			const struct cld_clntinfo __user *ci;
808 
809 			ci = &cmsg->cm_u.cm_clntinfo;
810 			if (get_user(namelen, &ci->cc_name.cn_len))
811 				return -EFAULT;
812 			name.data = memdup_user(&ci->cc_name.cn_id, namelen);
813 			if (IS_ERR(name.data))
814 				return PTR_ERR(name.data);
815 			name.len = namelen;
816 			get_user(princhashlen, &ci->cc_princhash.cp_len);
817 			if (princhashlen > 0) {
818 				princhash.data = memdup_user(
819 						&ci->cc_princhash.cp_data,
820 						princhashlen);
821 				if (IS_ERR(princhash.data)) {
822 					kfree(name.data);
823 					return PTR_ERR(princhash.data);
824 				}
825 				princhash.len = princhashlen;
826 			} else
827 				princhash.len = 0;
828 		} else {
829 			const struct cld_name __user *cnm;
830 
831 			cnm = &cmsg->cm_u.cm_name;
832 			if (get_user(namelen, &cnm->cn_len))
833 				return -EFAULT;
834 			name.data = memdup_user(&cnm->cn_id, namelen);
835 			if (IS_ERR(name.data))
836 				return PTR_ERR(name.data);
837 			name.len = namelen;
838 		}
839 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
840 		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
841 			struct cld_net *cn = nn->cld_net;
842 
843 			name.len = name.len - 5;
844 			memmove(name.data, name.data + 5, name.len);
845 			cn->cn_has_legacy = true;
846 		}
847 #endif
848 		if (!nfs4_client_to_reclaim(name, princhash, nn)) {
849 			kfree(name.data);
850 			kfree(princhash.data);
851 			return -EFAULT;
852 		}
853 		return nn->client_tracking_ops->msglen;
854 	}
855 	return -EFAULT;
856 }
857 
858 static ssize_t
859 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
860 {
861 	struct cld_upcall *tmp, *cup;
862 	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
863 	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
864 	uint32_t xid;
865 	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
866 						nfsd_net_id);
867 	struct cld_net *cn = nn->cld_net;
868 	int16_t status;
869 
870 	if (mlen != nn->client_tracking_ops->msglen) {
871 		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
872 			nn->client_tracking_ops->msglen);
873 		return -EINVAL;
874 	}
875 
876 	/* copy just the xid so we can try to find that */
877 	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
878 		dprintk("%s: error when copying xid from userspace", __func__);
879 		return -EFAULT;
880 	}
881 
882 	/*
883 	 * copy the status so we know whether to remove the upcall from the
884 	 * list (for -EINPROGRESS, we just want to make sure the xid is
885 	 * valid, not remove the upcall from the list)
886 	 */
887 	if (get_user(status, &hdr->cm_status)) {
888 		dprintk("%s: error when copying status from userspace", __func__);
889 		return -EFAULT;
890 	}
891 
892 	/* walk the list and find corresponding xid */
893 	cup = NULL;
894 	spin_lock(&cn->cn_lock);
895 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
896 		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
897 			cup = tmp;
898 			if (status != -EINPROGRESS)
899 				list_del_init(&cup->cu_list);
900 			break;
901 		}
902 	}
903 	spin_unlock(&cn->cn_lock);
904 
905 	/* couldn't find upcall? */
906 	if (!cup) {
907 		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
908 		return -EINVAL;
909 	}
910 
911 	if (status == -EINPROGRESS)
912 		return __cld_pipe_inprogress_downcall(cmsg, nn);
913 
914 	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
915 		return -EFAULT;
916 
917 	complete(&cup->cu_done);
918 	return mlen;
919 }
920 
921 static void
922 cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
923 {
924 	struct cld_msg *cmsg = msg->data;
925 	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
926 						 cu_u.cu_msg);
927 
928 	/* errno >= 0 means we got a downcall */
929 	if (msg->errno >= 0)
930 		return;
931 
932 	complete(&cup->cu_done);
933 }
934 
935 static const struct rpc_pipe_ops cld_upcall_ops = {
936 	.upcall		= rpc_pipe_generic_upcall,
937 	.downcall	= cld_pipe_downcall,
938 	.destroy_msg	= cld_pipe_destroy_msg,
939 };
940 
941 static struct dentry *
942 nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
943 {
944 	struct dentry *dir, *dentry;
945 
946 	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
947 	if (dir == NULL)
948 		return ERR_PTR(-ENOENT);
949 	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
950 	dput(dir);
951 	return dentry;
952 }
953 
954 static void
955 nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
956 {
957 	if (pipe->dentry)
958 		rpc_unlink(pipe->dentry);
959 }
960 
961 static struct dentry *
962 nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
963 {
964 	struct super_block *sb;
965 	struct dentry *dentry;
966 
967 	sb = rpc_get_sb_net(net);
968 	if (!sb)
969 		return NULL;
970 	dentry = nfsd4_cld_register_sb(sb, pipe);
971 	rpc_put_sb_net(net);
972 	return dentry;
973 }
974 
975 static void
976 nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
977 {
978 	struct super_block *sb;
979 
980 	sb = rpc_get_sb_net(net);
981 	if (sb) {
982 		nfsd4_cld_unregister_sb(pipe);
983 		rpc_put_sb_net(net);
984 	}
985 }
986 
987 /* Initialize rpc_pipefs pipe for communication with client tracking daemon */
988 static int
989 __nfsd4_init_cld_pipe(struct net *net)
990 {
991 	int ret;
992 	struct dentry *dentry;
993 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
994 	struct cld_net *cn;
995 
996 	if (nn->cld_net)
997 		return 0;
998 
999 	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
1000 	if (!cn) {
1001 		ret = -ENOMEM;
1002 		goto err;
1003 	}
1004 
1005 	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
1006 	if (IS_ERR(cn->cn_pipe)) {
1007 		ret = PTR_ERR(cn->cn_pipe);
1008 		goto err;
1009 	}
1010 	spin_lock_init(&cn->cn_lock);
1011 	INIT_LIST_HEAD(&cn->cn_list);
1012 
1013 	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
1014 	if (IS_ERR(dentry)) {
1015 		ret = PTR_ERR(dentry);
1016 		goto err_destroy_data;
1017 	}
1018 
1019 	cn->cn_pipe->dentry = dentry;
1020 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1021 	cn->cn_has_legacy = false;
1022 #endif
1023 	nn->cld_net = cn;
1024 	return 0;
1025 
1026 err_destroy_data:
1027 	rpc_destroy_pipe_data(cn->cn_pipe);
1028 err:
1029 	kfree(cn);
1030 	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
1031 			ret);
1032 	return ret;
1033 }
1034 
1035 static int
1036 nfsd4_init_cld_pipe(struct net *net)
1037 {
1038 	int status;
1039 
1040 	status = __nfsd4_init_cld_pipe(net);
1041 	if (!status)
1042 		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
1043 	return status;
1044 }
1045 
1046 static void
1047 nfsd4_remove_cld_pipe(struct net *net)
1048 {
1049 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1050 	struct cld_net *cn = nn->cld_net;
1051 
1052 	nfsd4_cld_unregister_net(net, cn->cn_pipe);
1053 	rpc_destroy_pipe_data(cn->cn_pipe);
1054 	if (cn->cn_tfm)
1055 		crypto_free_shash(cn->cn_tfm);
1056 	kfree(nn->cld_net);
1057 	nn->cld_net = NULL;
1058 }
1059 
1060 static struct cld_upcall *
1061 alloc_cld_upcall(struct nfsd_net *nn)
1062 {
1063 	struct cld_upcall *new, *tmp;
1064 	struct cld_net *cn = nn->cld_net;
1065 
1066 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1067 	if (!new)
1068 		return new;
1069 
1070 	/* FIXME: hard cap on number in flight? */
1071 restart_search:
1072 	spin_lock(&cn->cn_lock);
1073 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
1074 		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
1075 			cn->cn_xid++;
1076 			spin_unlock(&cn->cn_lock);
1077 			goto restart_search;
1078 		}
1079 	}
1080 	init_completion(&new->cu_done);
1081 	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
1082 	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
1083 	new->cu_net = cn;
1084 	list_add(&new->cu_list, &cn->cn_list);
1085 	spin_unlock(&cn->cn_lock);
1086 
1087 	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
1088 
1089 	return new;
1090 }
1091 
1092 static void
1093 free_cld_upcall(struct cld_upcall *victim)
1094 {
1095 	struct cld_net *cn = victim->cu_net;
1096 
1097 	spin_lock(&cn->cn_lock);
1098 	list_del(&victim->cu_list);
1099 	spin_unlock(&cn->cn_lock);
1100 	kfree(victim);
1101 }
1102 
1103 /* Ask daemon to create a new record */
1104 static void
1105 nfsd4_cld_create(struct nfs4_client *clp)
1106 {
1107 	int ret;
1108 	struct cld_upcall *cup;
1109 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1110 	struct cld_net *cn = nn->cld_net;
1111 
1112 	/* Don't upcall if it's already stored */
1113 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1114 		return;
1115 
1116 	cup = alloc_cld_upcall(nn);
1117 	if (!cup) {
1118 		ret = -ENOMEM;
1119 		goto out_err;
1120 	}
1121 
1122 	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
1123 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1124 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1125 			clp->cl_name.len);
1126 
1127 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1128 	if (!ret) {
1129 		ret = cup->cu_u.cu_msg.cm_status;
1130 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1131 	}
1132 
1133 	free_cld_upcall(cup);
1134 out_err:
1135 	if (ret)
1136 		printk(KERN_ERR "NFSD: Unable to create client "
1137 				"record on stable storage: %d\n", ret);
1138 }
1139 
1140 /* Ask daemon to create a new record */
1141 static void
1142 nfsd4_cld_create_v2(struct nfs4_client *clp)
1143 {
1144 	int ret;
1145 	struct cld_upcall *cup;
1146 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1147 	struct cld_net *cn = nn->cld_net;
1148 	struct cld_msg_v2 *cmsg;
1149 	struct crypto_shash *tfm = cn->cn_tfm;
1150 	struct xdr_netobj cksum;
1151 	char *principal = NULL;
1152 
1153 	/* Don't upcall if it's already stored */
1154 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1155 		return;
1156 
1157 	cup = alloc_cld_upcall(nn);
1158 	if (!cup) {
1159 		ret = -ENOMEM;
1160 		goto out_err;
1161 	}
1162 
1163 	cmsg = &cup->cu_u.cu_msg_v2;
1164 	cmsg->cm_cmd = Cld_Create;
1165 	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
1166 	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
1167 			clp->cl_name.len);
1168 	if (clp->cl_cred.cr_raw_principal)
1169 		principal = clp->cl_cred.cr_raw_principal;
1170 	else if (clp->cl_cred.cr_principal)
1171 		principal = clp->cl_cred.cr_principal;
1172 	if (principal) {
1173 		cksum.len = crypto_shash_digestsize(tfm);
1174 		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1175 		if (cksum.data == NULL) {
1176 			ret = -ENOMEM;
1177 			goto out;
1178 		}
1179 		ret = crypto_shash_tfm_digest(tfm, principal, strlen(principal),
1180 					      cksum.data);
1181 		if (ret) {
1182 			kfree(cksum.data);
1183 			goto out;
1184 		}
1185 		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = cksum.len;
1186 		memcpy(cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data,
1187 		       cksum.data, cksum.len);
1188 		kfree(cksum.data);
1189 	} else
1190 		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
1191 
1192 	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
1193 	if (!ret) {
1194 		ret = cmsg->cm_status;
1195 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1196 	}
1197 
1198 out:
1199 	free_cld_upcall(cup);
1200 out_err:
1201 	if (ret)
1202 		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
1203 				ret);
1204 }
1205 
1206 /* Ask daemon to create a new record */
1207 static void
1208 nfsd4_cld_remove(struct nfs4_client *clp)
1209 {
1210 	int ret;
1211 	struct cld_upcall *cup;
1212 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1213 	struct cld_net *cn = nn->cld_net;
1214 
1215 	/* Don't upcall if it's already removed */
1216 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1217 		return;
1218 
1219 	cup = alloc_cld_upcall(nn);
1220 	if (!cup) {
1221 		ret = -ENOMEM;
1222 		goto out_err;
1223 	}
1224 
1225 	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
1226 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1227 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1228 			clp->cl_name.len);
1229 
1230 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1231 	if (!ret) {
1232 		ret = cup->cu_u.cu_msg.cm_status;
1233 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1234 	}
1235 
1236 	free_cld_upcall(cup);
1237 out_err:
1238 	if (ret)
1239 		printk(KERN_ERR "NFSD: Unable to remove client "
1240 				"record from stable storage: %d\n", ret);
1241 }
1242 
1243 /*
1244  * For older nfsdcld's that do not allow us to "slurp" the clients
1245  * from the tracking database during startup.
1246  *
1247  * Check for presence of a record, and update its timestamp
1248  */
1249 static int
1250 nfsd4_cld_check_v0(struct nfs4_client *clp)
1251 {
1252 	int ret;
1253 	struct cld_upcall *cup;
1254 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1255 	struct cld_net *cn = nn->cld_net;
1256 
1257 	/* Don't upcall if one was already stored during this grace pd */
1258 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1259 		return 0;
1260 
1261 	cup = alloc_cld_upcall(nn);
1262 	if (!cup) {
1263 		printk(KERN_ERR "NFSD: Unable to check client record on "
1264 				"stable storage: %d\n", -ENOMEM);
1265 		return -ENOMEM;
1266 	}
1267 
1268 	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
1269 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1270 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1271 			clp->cl_name.len);
1272 
1273 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1274 	if (!ret) {
1275 		ret = cup->cu_u.cu_msg.cm_status;
1276 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1277 	}
1278 
1279 	free_cld_upcall(cup);
1280 	return ret;
1281 }
1282 
1283 /*
1284  * For newer nfsdcld's that allow us to "slurp" the clients
1285  * from the tracking database during startup.
1286  *
1287  * Check for presence of a record in the reclaim_str_hashtbl
1288  */
1289 static int
1290 nfsd4_cld_check(struct nfs4_client *clp)
1291 {
1292 	struct nfs4_client_reclaim *crp;
1293 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1294 
1295 	/* did we already find that this client is stable? */
1296 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1297 		return 0;
1298 
1299 	/* look for it in the reclaim hashtable otherwise */
1300 	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1301 	if (crp)
1302 		goto found;
1303 
1304 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1305 	if (nn->cld_net->cn_has_legacy) {
1306 		int status;
1307 		char dname[HEXDIR_LEN];
1308 		struct xdr_netobj name;
1309 
1310 		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1311 		if (status)
1312 			return -ENOENT;
1313 
1314 		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1315 		if (!name.data) {
1316 			dprintk("%s: failed to allocate memory for name.data!\n",
1317 				__func__);
1318 			return -ENOENT;
1319 		}
1320 		name.len = HEXDIR_LEN;
1321 		crp = nfsd4_find_reclaim_client(name, nn);
1322 		kfree(name.data);
1323 		if (crp)
1324 			goto found;
1325 
1326 	}
1327 #endif
1328 	return -ENOENT;
1329 found:
1330 	crp->cr_clp = clp;
1331 	return 0;
1332 }
1333 
1334 static int
1335 nfsd4_cld_check_v2(struct nfs4_client *clp)
1336 {
1337 	struct nfs4_client_reclaim *crp;
1338 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1339 	struct cld_net *cn = nn->cld_net;
1340 	int status;
1341 	struct crypto_shash *tfm = cn->cn_tfm;
1342 	struct xdr_netobj cksum;
1343 	char *principal = NULL;
1344 
1345 	/* did we already find that this client is stable? */
1346 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1347 		return 0;
1348 
1349 	/* look for it in the reclaim hashtable otherwise */
1350 	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1351 	if (crp)
1352 		goto found;
1353 
1354 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1355 	if (cn->cn_has_legacy) {
1356 		struct xdr_netobj name;
1357 		char dname[HEXDIR_LEN];
1358 
1359 		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1360 		if (status)
1361 			return -ENOENT;
1362 
1363 		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1364 		if (!name.data) {
1365 			dprintk("%s: failed to allocate memory for name.data\n",
1366 					__func__);
1367 			return -ENOENT;
1368 		}
1369 		name.len = HEXDIR_LEN;
1370 		crp = nfsd4_find_reclaim_client(name, nn);
1371 		kfree(name.data);
1372 		if (crp)
1373 			goto found;
1374 
1375 	}
1376 #endif
1377 	return -ENOENT;
1378 found:
1379 	if (crp->cr_princhash.len) {
1380 		if (clp->cl_cred.cr_raw_principal)
1381 			principal = clp->cl_cred.cr_raw_principal;
1382 		else if (clp->cl_cred.cr_principal)
1383 			principal = clp->cl_cred.cr_principal;
1384 		if (principal == NULL)
1385 			return -ENOENT;
1386 		cksum.len = crypto_shash_digestsize(tfm);
1387 		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1388 		if (cksum.data == NULL)
1389 			return -ENOENT;
1390 		status = crypto_shash_tfm_digest(tfm, principal,
1391 						 strlen(principal), cksum.data);
1392 		if (status) {
1393 			kfree(cksum.data);
1394 			return -ENOENT;
1395 		}
1396 		if (memcmp(crp->cr_princhash.data, cksum.data,
1397 				crp->cr_princhash.len)) {
1398 			kfree(cksum.data);
1399 			return -ENOENT;
1400 		}
1401 		kfree(cksum.data);
1402 	}
1403 	crp->cr_clp = clp;
1404 	return 0;
1405 }
1406 
1407 static int
1408 nfsd4_cld_grace_start(struct nfsd_net *nn)
1409 {
1410 	int ret;
1411 	struct cld_upcall *cup;
1412 	struct cld_net *cn = nn->cld_net;
1413 
1414 	cup = alloc_cld_upcall(nn);
1415 	if (!cup) {
1416 		ret = -ENOMEM;
1417 		goto out_err;
1418 	}
1419 
1420 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
1421 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1422 	if (!ret)
1423 		ret = cup->cu_u.cu_msg.cm_status;
1424 
1425 	free_cld_upcall(cup);
1426 out_err:
1427 	if (ret)
1428 		dprintk("%s: Unable to get clients from userspace: %d\n",
1429 			__func__, ret);
1430 	return ret;
1431 }
1432 
1433 /* For older nfsdcld's that need cm_gracetime */
1434 static void
1435 nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
1436 {
1437 	int ret;
1438 	struct cld_upcall *cup;
1439 	struct cld_net *cn = nn->cld_net;
1440 
1441 	cup = alloc_cld_upcall(nn);
1442 	if (!cup) {
1443 		ret = -ENOMEM;
1444 		goto out_err;
1445 	}
1446 
1447 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1448 	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
1449 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1450 	if (!ret)
1451 		ret = cup->cu_u.cu_msg.cm_status;
1452 
1453 	free_cld_upcall(cup);
1454 out_err:
1455 	if (ret)
1456 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1457 }
1458 
1459 /*
1460  * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
1461  * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
1462  */
1463 static void
1464 nfsd4_cld_grace_done(struct nfsd_net *nn)
1465 {
1466 	int ret;
1467 	struct cld_upcall *cup;
1468 	struct cld_net *cn = nn->cld_net;
1469 
1470 	cup = alloc_cld_upcall(nn);
1471 	if (!cup) {
1472 		ret = -ENOMEM;
1473 		goto out_err;
1474 	}
1475 
1476 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1477 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1478 	if (!ret)
1479 		ret = cup->cu_u.cu_msg.cm_status;
1480 
1481 	free_cld_upcall(cup);
1482 out_err:
1483 	nfs4_release_reclaim(nn);
1484 	if (ret)
1485 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1486 }
1487 
1488 static int
1489 nfs4_cld_state_init(struct net *net)
1490 {
1491 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1492 	int i;
1493 
1494 	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
1495 						sizeof(struct list_head),
1496 						GFP_KERNEL);
1497 	if (!nn->reclaim_str_hashtbl)
1498 		return -ENOMEM;
1499 
1500 	for (i = 0; i < CLIENT_HASH_SIZE; i++)
1501 		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
1502 	nn->reclaim_str_hashtbl_size = 0;
1503 	nn->track_reclaim_completes = true;
1504 	atomic_set(&nn->nr_reclaim_complete, 0);
1505 
1506 	return 0;
1507 }
1508 
1509 static void
1510 nfs4_cld_state_shutdown(struct net *net)
1511 {
1512 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1513 
1514 	nn->track_reclaim_completes = false;
1515 	kfree(nn->reclaim_str_hashtbl);
1516 }
1517 
1518 static bool
1519 cld_running(struct nfsd_net *nn)
1520 {
1521 	struct cld_net *cn = nn->cld_net;
1522 	struct rpc_pipe *pipe = cn->cn_pipe;
1523 
1524 	return pipe->nreaders || pipe->nwriters;
1525 }
1526 
1527 static int
1528 nfsd4_cld_get_version(struct nfsd_net *nn)
1529 {
1530 	int ret = 0;
1531 	struct cld_upcall *cup;
1532 	struct cld_net *cn = nn->cld_net;
1533 	uint8_t version;
1534 
1535 	cup = alloc_cld_upcall(nn);
1536 	if (!cup) {
1537 		ret = -ENOMEM;
1538 		goto out_err;
1539 	}
1540 	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
1541 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1542 	if (!ret) {
1543 		ret = cup->cu_u.cu_msg.cm_status;
1544 		if (ret)
1545 			goto out_free;
1546 		version = cup->cu_u.cu_msg.cm_u.cm_version;
1547 		dprintk("%s: userspace returned version %u\n",
1548 				__func__, version);
1549 		if (version < 1)
1550 			version = 1;
1551 		else if (version > CLD_UPCALL_VERSION)
1552 			version = CLD_UPCALL_VERSION;
1553 
1554 		switch (version) {
1555 		case 1:
1556 			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1557 			break;
1558 		case 2:
1559 			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
1560 			break;
1561 		default:
1562 			break;
1563 		}
1564 	}
1565 out_free:
1566 	free_cld_upcall(cup);
1567 out_err:
1568 	if (ret)
1569 		dprintk("%s: Unable to get version from userspace: %d\n",
1570 			__func__, ret);
1571 	return ret;
1572 }
1573 
1574 static int
1575 nfsd4_cld_tracking_init(struct net *net)
1576 {
1577 	int status;
1578 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1579 	bool running;
1580 	int retries = 10;
1581 	struct crypto_shash *tfm;
1582 
1583 	status = nfs4_cld_state_init(net);
1584 	if (status)
1585 		return status;
1586 
1587 	status = __nfsd4_init_cld_pipe(net);
1588 	if (status)
1589 		goto err_shutdown;
1590 
1591 	/*
1592 	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
1593 	 * queue an upcall unless we know that nfsdcld is running (because we
1594 	 * want this to fail fast so that nfsd4_client_tracking_init() can try
1595 	 * the next client tracking method).  nfsdcld should already be running
1596 	 * before nfsd is started, so the wait here is for nfsdcld to open the
1597 	 * pipefs file we just created.
1598 	 */
1599 	while (!(running = cld_running(nn)) && retries--)
1600 		msleep(100);
1601 
1602 	if (!running) {
1603 		status = -ETIMEDOUT;
1604 		goto err_remove;
1605 	}
1606 	tfm = crypto_alloc_shash("sha256", 0, 0);
1607 	if (IS_ERR(tfm)) {
1608 		status = PTR_ERR(tfm);
1609 		goto err_remove;
1610 	}
1611 	nn->cld_net->cn_tfm = tfm;
1612 
1613 	status = nfsd4_cld_get_version(nn);
1614 	if (status == -EOPNOTSUPP)
1615 		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
1616 
1617 	status = nfsd4_cld_grace_start(nn);
1618 	if (status) {
1619 		if (status == -EOPNOTSUPP)
1620 			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
1621 		nfs4_release_reclaim(nn);
1622 		goto err_remove;
1623 	} else
1624 		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
1625 	return 0;
1626 
1627 err_remove:
1628 	nfsd4_remove_cld_pipe(net);
1629 err_shutdown:
1630 	nfs4_cld_state_shutdown(net);
1631 	return status;
1632 }
1633 
1634 static void
1635 nfsd4_cld_tracking_exit(struct net *net)
1636 {
1637 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1638 
1639 	nfs4_release_reclaim(nn);
1640 	nfsd4_remove_cld_pipe(net);
1641 	nfs4_cld_state_shutdown(net);
1642 }
1643 
1644 /* For older nfsdcld's */
1645 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
1646 	.init		= nfsd4_init_cld_pipe,
1647 	.exit		= nfsd4_remove_cld_pipe,
1648 	.create		= nfsd4_cld_create,
1649 	.remove		= nfsd4_cld_remove,
1650 	.check		= nfsd4_cld_check_v0,
1651 	.grace_done	= nfsd4_cld_grace_done_v0,
1652 	.version	= 1,
1653 	.msglen		= sizeof(struct cld_msg),
1654 };
1655 
1656 /* For newer nfsdcld's */
1657 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1658 	.init		= nfsd4_cld_tracking_init,
1659 	.exit		= nfsd4_cld_tracking_exit,
1660 	.create		= nfsd4_cld_create,
1661 	.remove		= nfsd4_cld_remove,
1662 	.check		= nfsd4_cld_check,
1663 	.grace_done	= nfsd4_cld_grace_done,
1664 	.version	= 1,
1665 	.msglen		= sizeof(struct cld_msg),
1666 };
1667 
1668 /* v2 create/check ops include the principal, if available */
1669 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
1670 	.init		= nfsd4_cld_tracking_init,
1671 	.exit		= nfsd4_cld_tracking_exit,
1672 	.create		= nfsd4_cld_create_v2,
1673 	.remove		= nfsd4_cld_remove,
1674 	.check		= nfsd4_cld_check_v2,
1675 	.grace_done	= nfsd4_cld_grace_done,
1676 	.version	= 2,
1677 	.msglen		= sizeof(struct cld_msg_v2),
1678 };
1679 
1680 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1681 /* upcall via usermodehelper */
1682 static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1683 module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1684 			S_IRUGO|S_IWUSR);
1685 MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1686 
1687 static bool cltrack_legacy_disable;
1688 module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1689 MODULE_PARM_DESC(cltrack_legacy_disable,
1690 		"Disable legacy recoverydir conversion. Default: false");
1691 
1692 #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1693 #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1694 #define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1695 #define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1696 
1697 static char *
1698 nfsd4_cltrack_legacy_topdir(void)
1699 {
1700 	int copied;
1701 	size_t len;
1702 	char *result;
1703 
1704 	if (cltrack_legacy_disable)
1705 		return NULL;
1706 
1707 	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1708 		strlen(nfs4_recoverydir()) + 1;
1709 
1710 	result = kmalloc(len, GFP_KERNEL);
1711 	if (!result)
1712 		return result;
1713 
1714 	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1715 				nfs4_recoverydir());
1716 	if (copied >= len) {
1717 		/* just return nothing if output was truncated */
1718 		kfree(result);
1719 		return NULL;
1720 	}
1721 
1722 	return result;
1723 }
1724 
1725 static char *
1726 nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1727 {
1728 	int copied;
1729 	size_t len;
1730 	char *result;
1731 
1732 	if (cltrack_legacy_disable)
1733 		return NULL;
1734 
1735 	/* +1 is for '/' between "topdir" and "recdir" */
1736 	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1737 		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1738 
1739 	result = kmalloc(len, GFP_KERNEL);
1740 	if (!result)
1741 		return result;
1742 
1743 	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1744 				nfs4_recoverydir());
1745 	if (copied > (len - HEXDIR_LEN)) {
1746 		/* just return nothing if output will be truncated */
1747 		kfree(result);
1748 		return NULL;
1749 	}
1750 
1751 	copied = nfs4_make_rec_clidname(result + copied, name);
1752 	if (copied) {
1753 		kfree(result);
1754 		return NULL;
1755 	}
1756 
1757 	return result;
1758 }
1759 
1760 static char *
1761 nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1762 {
1763 	int copied;
1764 	size_t len;
1765 	char *result;
1766 
1767 	/* prefix + Y/N character + terminating NULL */
1768 	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1769 
1770 	result = kmalloc(len, GFP_KERNEL);
1771 	if (!result)
1772 		return result;
1773 
1774 	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1775 				clp->cl_minorversion ? 'Y' : 'N');
1776 	if (copied >= len) {
1777 		/* just return nothing if output was truncated */
1778 		kfree(result);
1779 		return NULL;
1780 	}
1781 
1782 	return result;
1783 }
1784 
1785 static char *
1786 nfsd4_cltrack_grace_start(time64_t grace_start)
1787 {
1788 	int copied;
1789 	size_t len;
1790 	char *result;
1791 
1792 	/* prefix + max width of int64_t string + terminating NULL */
1793 	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1794 
1795 	result = kmalloc(len, GFP_KERNEL);
1796 	if (!result)
1797 		return result;
1798 
1799 	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
1800 				grace_start);
1801 	if (copied >= len) {
1802 		/* just return nothing if output was truncated */
1803 		kfree(result);
1804 		return NULL;
1805 	}
1806 
1807 	return result;
1808 }
1809 
1810 static int
1811 nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1812 {
1813 	char *envp[3];
1814 	char *argv[4];
1815 	int ret;
1816 
1817 	if (unlikely(!cltrack_prog[0])) {
1818 		dprintk("%s: cltrack_prog is disabled\n", __func__);
1819 		return -EACCES;
1820 	}
1821 
1822 	dprintk("%s: cmd: %s\n", __func__, cmd);
1823 	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1824 	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1825 	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1826 
1827 	envp[0] = env0;
1828 	envp[1] = env1;
1829 	envp[2] = NULL;
1830 
1831 	argv[0] = (char *)cltrack_prog;
1832 	argv[1] = cmd;
1833 	argv[2] = arg;
1834 	argv[3] = NULL;
1835 
1836 	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1837 	/*
1838 	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1839 	 * error. The admin can re-enable it on the fly by using sysfs
1840 	 * once the problem has been fixed.
1841 	 */
1842 	if (ret == -ENOENT || ret == -EACCES) {
1843 		dprintk("NFSD: %s was not found or isn't executable (%d). "
1844 			"Setting cltrack_prog to blank string!",
1845 			cltrack_prog, ret);
1846 		cltrack_prog[0] = '\0';
1847 	}
1848 	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1849 
1850 	return ret;
1851 }
1852 
1853 static char *
1854 bin_to_hex_dup(const unsigned char *src, int srclen)
1855 {
1856 	char *buf;
1857 
1858 	/* +1 for terminating NULL */
1859 	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
1860 	if (!buf)
1861 		return buf;
1862 
1863 	bin2hex(buf, src, srclen);
1864 	return buf;
1865 }
1866 
1867 static int
1868 nfsd4_umh_cltrack_init(struct net *net)
1869 {
1870 	int ret;
1871 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1872 	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1873 
1874 	/* XXX: The usermode helper s not working in container yet. */
1875 	if (net != &init_net) {
1876 		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1877 		kfree(grace_start);
1878 		return -EINVAL;
1879 	}
1880 
1881 	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1882 	kfree(grace_start);
1883 	if (!ret)
1884 		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
1885 	return ret;
1886 }
1887 
1888 static void
1889 nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1890 {
1891 	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1892 			 TASK_UNINTERRUPTIBLE);
1893 }
1894 
1895 static void
1896 nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1897 {
1898 	smp_mb__before_atomic();
1899 	clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1900 	smp_mb__after_atomic();
1901 	wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
1902 }
1903 
1904 static void
1905 nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1906 {
1907 	char *hexid, *has_session, *grace_start;
1908 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1909 
1910 	/*
1911 	 * With v4.0 clients, there's little difference in outcome between a
1912 	 * create and check operation, and we can end up calling into this
1913 	 * function multiple times per client (once for each openowner). So,
1914 	 * for v4.0 clients skip upcalling once the client has been recorded
1915 	 * on stable storage.
1916 	 *
1917 	 * For v4.1+ clients, the outcome of the two operations is different,
1918 	 * so we must ensure that we upcall for the create operation. v4.1+
1919 	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1920 	 * up doing a single create upcall per client.
1921 	 */
1922 	if (clp->cl_minorversion == 0 &&
1923 	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1924 		return;
1925 
1926 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1927 	if (!hexid) {
1928 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1929 		return;
1930 	}
1931 
1932 	has_session = nfsd4_cltrack_client_has_session(clp);
1933 	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1934 
1935 	nfsd4_cltrack_upcall_lock(clp);
1936 	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1937 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1938 	nfsd4_cltrack_upcall_unlock(clp);
1939 
1940 	kfree(has_session);
1941 	kfree(grace_start);
1942 	kfree(hexid);
1943 }
1944 
1945 static void
1946 nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1947 {
1948 	char *hexid;
1949 
1950 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1951 		return;
1952 
1953 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1954 	if (!hexid) {
1955 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1956 		return;
1957 	}
1958 
1959 	nfsd4_cltrack_upcall_lock(clp);
1960 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1961 	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1962 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1963 	nfsd4_cltrack_upcall_unlock(clp);
1964 
1965 	kfree(hexid);
1966 }
1967 
1968 static int
1969 nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1970 {
1971 	int ret;
1972 	char *hexid, *has_session, *legacy;
1973 
1974 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1975 		return 0;
1976 
1977 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1978 	if (!hexid) {
1979 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1980 		return -ENOMEM;
1981 	}
1982 
1983 	has_session = nfsd4_cltrack_client_has_session(clp);
1984 	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1985 
1986 	nfsd4_cltrack_upcall_lock(clp);
1987 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1988 		ret = 0;
1989 	} else {
1990 		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1991 		if (ret == 0)
1992 			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1993 	}
1994 	nfsd4_cltrack_upcall_unlock(clp);
1995 	kfree(has_session);
1996 	kfree(legacy);
1997 	kfree(hexid);
1998 
1999 	return ret;
2000 }
2001 
2002 static void
2003 nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
2004 {
2005 	char *legacy;
2006 	char timestr[22]; /* FIXME: better way to determine max size? */
2007 
2008 	sprintf(timestr, "%lld", nn->boot_time);
2009 	legacy = nfsd4_cltrack_legacy_topdir();
2010 	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
2011 	kfree(legacy);
2012 }
2013 
2014 static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
2015 	.init		= nfsd4_umh_cltrack_init,
2016 	.exit		= NULL,
2017 	.create		= nfsd4_umh_cltrack_create,
2018 	.remove		= nfsd4_umh_cltrack_remove,
2019 	.check		= nfsd4_umh_cltrack_check,
2020 	.grace_done	= nfsd4_umh_cltrack_grace_done,
2021 	.version	= 1,
2022 	.msglen		= 0,
2023 };
2024 
2025 static inline int check_for_legacy_methods(int status, struct net *net)
2026 {
2027 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2028 	struct path path;
2029 
2030 	/*
2031 	 * Next, try the UMH upcall.
2032 	 */
2033 	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
2034 	status = nn->client_tracking_ops->init(net);
2035 	if (!status)
2036 		return status;
2037 
2038 	/*
2039 	 * Finally, See if the recoverydir exists and is a directory.
2040 	 * If it is, then use the legacy ops.
2041 	 */
2042 	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
2043 	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
2044 	if (!status) {
2045 		status = !d_is_dir(path.dentry);
2046 		path_put(&path);
2047 		if (status)
2048 			return -ENOTDIR;
2049 		status = nn->client_tracking_ops->init(net);
2050 	}
2051 	return status;
2052 }
2053 #else
2054 static inline int check_for_legacy_methods(int status, struct net *net)
2055 {
2056 	return status;
2057 }
2058 #endif /* CONFIG_LEGACY_NFSD_CLIENT_TRACKING */
2059 
2060 int
2061 nfsd4_client_tracking_init(struct net *net)
2062 {
2063 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2064 	int status;
2065 
2066 	/* just run the init if it the method is already decided */
2067 	if (nn->client_tracking_ops)
2068 		goto do_init;
2069 
2070 	/* First, try to use nfsdcld */
2071 	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
2072 	status = nn->client_tracking_ops->init(net);
2073 	if (!status)
2074 		return status;
2075 	if (status != -ETIMEDOUT) {
2076 		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
2077 		status = nn->client_tracking_ops->init(net);
2078 		if (!status)
2079 			return status;
2080 	}
2081 
2082 	status = check_for_legacy_methods(status, net);
2083 	if (status)
2084 		goto out;
2085 do_init:
2086 	status = nn->client_tracking_ops->init(net);
2087 out:
2088 	if (status) {
2089 		printk(KERN_WARNING "NFSD: Unable to initialize client "
2090 				    "recovery tracking! (%d)\n", status);
2091 		nn->client_tracking_ops = NULL;
2092 	}
2093 	return status;
2094 }
2095 
2096 void
2097 nfsd4_client_tracking_exit(struct net *net)
2098 {
2099 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2100 
2101 	if (nn->client_tracking_ops) {
2102 		if (nn->client_tracking_ops->exit)
2103 			nn->client_tracking_ops->exit(net);
2104 		nn->client_tracking_ops = NULL;
2105 	}
2106 }
2107 
2108 void
2109 nfsd4_client_record_create(struct nfs4_client *clp)
2110 {
2111 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2112 
2113 	if (nn->client_tracking_ops)
2114 		nn->client_tracking_ops->create(clp);
2115 }
2116 
2117 void
2118 nfsd4_client_record_remove(struct nfs4_client *clp)
2119 {
2120 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2121 
2122 	if (nn->client_tracking_ops)
2123 		nn->client_tracking_ops->remove(clp);
2124 }
2125 
2126 int
2127 nfsd4_client_record_check(struct nfs4_client *clp)
2128 {
2129 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2130 
2131 	if (nn->client_tracking_ops)
2132 		return nn->client_tracking_ops->check(clp);
2133 
2134 	return -EOPNOTSUPP;
2135 }
2136 
2137 void
2138 nfsd4_record_grace_done(struct nfsd_net *nn)
2139 {
2140 	if (nn->client_tracking_ops)
2141 		nn->client_tracking_ops->grace_done(nn);
2142 }
2143 
2144 static int
2145 rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
2146 {
2147 	struct super_block *sb = ptr;
2148 	struct net *net = sb->s_fs_info;
2149 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2150 	struct cld_net *cn = nn->cld_net;
2151 	struct dentry *dentry;
2152 	int ret = 0;
2153 
2154 	if (!try_module_get(THIS_MODULE))
2155 		return 0;
2156 
2157 	if (!cn) {
2158 		module_put(THIS_MODULE);
2159 		return 0;
2160 	}
2161 
2162 	switch (event) {
2163 	case RPC_PIPEFS_MOUNT:
2164 		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
2165 		if (IS_ERR(dentry)) {
2166 			ret = PTR_ERR(dentry);
2167 			break;
2168 		}
2169 		cn->cn_pipe->dentry = dentry;
2170 		break;
2171 	case RPC_PIPEFS_UMOUNT:
2172 		if (cn->cn_pipe->dentry)
2173 			nfsd4_cld_unregister_sb(cn->cn_pipe);
2174 		break;
2175 	default:
2176 		ret = -ENOTSUPP;
2177 		break;
2178 	}
2179 	module_put(THIS_MODULE);
2180 	return ret;
2181 }
2182 
2183 static struct notifier_block nfsd4_cld_block = {
2184 	.notifier_call = rpc_pipefs_event,
2185 };
2186 
2187 int
2188 register_cld_notifier(void)
2189 {
2190 	WARN_ON(!nfsd_net_id);
2191 	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
2192 }
2193 
2194 void
2195 unregister_cld_notifier(void)
2196 {
2197 	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
2198 }
2199