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 <crypto/sha2.h>
37 #include <linux/file.h>
38 #include <linux/slab.h>
39 #include <linux/namei.h>
40 #include <linux/sched.h>
41 #include <linux/fs.h>
42 #include <linux/module.h>
43 #include <net/net_namespace.h>
44 #include <linux/sunrpc/rpc_pipe_fs.h>
45 #include <linux/sunrpc/clnt.h>
46 #include <linux/nfsd/cld.h>
47 
48 #include "nfsd.h"
49 #include "state.h"
50 #include "vfs.h"
51 #include "netns.h"
52 
53 #define NFSDDBG_FACILITY                NFSDDBG_PROC
54 
55 /* Declarations */
56 struct nfsd4_client_tracking_ops {
57 	int (*init)(struct net *);
58 	void (*exit)(struct net *);
59 	void (*create)(struct nfs4_client *);
60 	void (*remove)(struct nfs4_client *);
61 	int (*check)(struct nfs4_client *);
62 	void (*grace_done)(struct nfsd_net *);
63 	uint8_t version;
64 	size_t msglen;
65 };
66 
67 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
68 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2;
69 
70 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
71 /* Globals */
72 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
73 
74 static int
75 nfs4_save_creds(const struct cred **original_creds)
76 {
77 	struct cred *new;
78 
79 	new = prepare_creds();
80 	if (!new)
81 		return -ENOMEM;
82 
83 	new->fsuid = GLOBAL_ROOT_UID;
84 	new->fsgid = GLOBAL_ROOT_GID;
85 	*original_creds = override_creds(new);
86 	return 0;
87 }
88 
89 static void
90 nfs4_reset_creds(const struct cred *original)
91 {
92 	put_cred(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(&nop_mnt_idmap, &QSTR(dname), dir);
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 	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
238 	if (IS_ERR(dentry))
239 		status = PTR_ERR(dentry);
240 out_put:
241 	if (!status)
242 		dput(dentry);
243 out_unlock:
244 	inode_unlock(d_inode(dir));
245 	if (status == 0) {
246 		if (nn->in_grace)
247 			__nfsd4_create_reclaim_record_grace(clp, dname,
248 					HEXDIR_LEN, nn);
249 		vfs_fsync(nn->rec_file, 0);
250 	} else {
251 		printk(KERN_ERR "NFSD: failed to write recovery record"
252 				" (err %d); please check that %s exists"
253 				" and is writeable", status,
254 				user_recovery_dirname);
255 	}
256 	mnt_drop_write_file(nn->rec_file);
257 out_creds:
258 	nfs4_reset_creds(original_cred);
259 }
260 
261 typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
262 
263 struct name_list {
264 	char name[HEXDIR_LEN];
265 	struct list_head list;
266 };
267 
268 struct nfs4_dir_ctx {
269 	struct dir_context ctx;
270 	struct list_head names;
271 };
272 
273 static bool
274 nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
275 		loff_t offset, u64 ino, unsigned int d_type)
276 {
277 	struct nfs4_dir_ctx *ctx =
278 		container_of(__ctx, struct nfs4_dir_ctx, ctx);
279 	struct name_list *entry;
280 
281 	if (namlen != HEXDIR_LEN - 1)
282 		return true;
283 	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
284 	if (entry == NULL)
285 		return false;
286 	memcpy(entry->name, name, HEXDIR_LEN - 1);
287 	entry->name[HEXDIR_LEN - 1] = '\0';
288 	list_add(&entry->list, &ctx->names);
289 	return true;
290 }
291 
292 static int
293 nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
294 {
295 	const struct cred *original_cred;
296 	struct dentry *dir = nn->rec_file->f_path.dentry;
297 	struct nfs4_dir_ctx ctx = {
298 		.ctx.actor = nfsd4_build_namelist,
299 		.names = LIST_HEAD_INIT(ctx.names)
300 	};
301 	struct name_list *entry, *tmp;
302 	int status;
303 
304 	status = nfs4_save_creds(&original_cred);
305 	if (status < 0)
306 		return status;
307 
308 	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
309 	if (status < 0) {
310 		nfs4_reset_creds(original_cred);
311 		return status;
312 	}
313 
314 	status = iterate_dir(nn->rec_file, &ctx.ctx);
315 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
316 
317 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
318 		if (!status) {
319 			struct dentry *dentry;
320 			dentry = lookup_one(&nop_mnt_idmap,
321 					    &QSTR(entry->name), dir);
322 			if (IS_ERR(dentry)) {
323 				status = PTR_ERR(dentry);
324 				break;
325 			}
326 			status = f(dir, dentry, nn);
327 			dput(dentry);
328 		}
329 		list_del(&entry->list);
330 		kfree(entry);
331 	}
332 	inode_unlock(d_inode(dir));
333 	nfs4_reset_creds(original_cred);
334 
335 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
336 		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
337 		list_del(&entry->list);
338 		kfree(entry);
339 	}
340 	return status;
341 }
342 
343 static int
344 nfsd4_unlink_clid_dir(char *name, struct nfsd_net *nn)
345 {
346 	struct dentry *dir, *dentry;
347 	int status;
348 
349 	dprintk("NFSD: nfsd4_unlink_clid_dir. name %s\n", name);
350 
351 	dir = nn->rec_file->f_path.dentry;
352 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
353 	dentry = lookup_one(&nop_mnt_idmap, &QSTR(name), dir);
354 	if (IS_ERR(dentry)) {
355 		status = PTR_ERR(dentry);
356 		goto out_unlock;
357 	}
358 	status = -ENOENT;
359 	if (d_really_is_negative(dentry))
360 		goto out;
361 	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry);
362 out:
363 	dput(dentry);
364 out_unlock:
365 	inode_unlock(d_inode(dir));
366 	return status;
367 }
368 
369 static void
370 __nfsd4_remove_reclaim_record_grace(const char *dname, int len,
371 		struct nfsd_net *nn)
372 {
373 	struct xdr_netobj name;
374 	struct nfs4_client_reclaim *crp;
375 
376 	name.data = kmemdup(dname, len, GFP_KERNEL);
377 	if (!name.data) {
378 		dprintk("%s: failed to allocate memory for name.data!\n",
379 			__func__);
380 		return;
381 	}
382 	name.len = len;
383 	crp = nfsd4_find_reclaim_client(name, nn);
384 	kfree(name.data);
385 	if (crp)
386 		nfs4_remove_reclaim_record(crp, nn);
387 }
388 
389 static void
390 nfsd4_remove_clid_dir(struct nfs4_client *clp)
391 {
392 	const struct cred *original_cred;
393 	char dname[HEXDIR_LEN];
394 	int status;
395 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
396 
397 	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
398 		return;
399 
400 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
401 	if (status)
402 		return legacy_recdir_name_error(clp, status);
403 
404 	status = mnt_want_write_file(nn->rec_file);
405 	if (status)
406 		goto out;
407 	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
408 
409 	status = nfs4_save_creds(&original_cred);
410 	if (status < 0)
411 		goto out_drop_write;
412 
413 	status = nfsd4_unlink_clid_dir(dname, nn);
414 	nfs4_reset_creds(original_cred);
415 	if (status == 0) {
416 		vfs_fsync(nn->rec_file, 0);
417 		if (nn->in_grace)
418 			__nfsd4_remove_reclaim_record_grace(dname,
419 					HEXDIR_LEN, nn);
420 	}
421 out_drop_write:
422 	mnt_drop_write_file(nn->rec_file);
423 out:
424 	if (status)
425 		printk("NFSD: Failed to remove expired client state directory"
426 				" %.*s\n", HEXDIR_LEN, dname);
427 }
428 
429 static int
430 purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
431 {
432 	int status;
433 	struct xdr_netobj name;
434 
435 	if (child->d_name.len != HEXDIR_LEN - 1) {
436 		printk("%s: illegal name %pd in recovery directory\n",
437 				__func__, child);
438 		/* Keep trying; maybe the others are OK: */
439 		return 0;
440 	}
441 	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
442 	if (!name.data) {
443 		dprintk("%s: failed to allocate memory for name.data!\n",
444 			__func__);
445 		goto out;
446 	}
447 	name.len = HEXDIR_LEN;
448 	if (nfs4_has_reclaimed_state(name, nn))
449 		goto out_free;
450 
451 	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
452 	if (status)
453 		printk("failed to remove client recovery directory %pd\n",
454 				child);
455 out_free:
456 	kfree(name.data);
457 out:
458 	/* Keep trying, success or failure: */
459 	return 0;
460 }
461 
462 static void
463 nfsd4_recdir_purge_old(struct nfsd_net *nn)
464 {
465 	int status;
466 
467 	nn->in_grace = false;
468 	if (!nn->rec_file)
469 		return;
470 	status = mnt_want_write_file(nn->rec_file);
471 	if (status)
472 		goto out;
473 	status = nfsd4_list_rec_dir(purge_old, nn);
474 	if (status == 0)
475 		vfs_fsync(nn->rec_file, 0);
476 	mnt_drop_write_file(nn->rec_file);
477 out:
478 	nfs4_release_reclaim(nn);
479 	if (status)
480 		printk("nfsd4: failed to purge old clients from recovery"
481 			" directory %pD\n", nn->rec_file);
482 }
483 
484 static int
485 load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
486 {
487 	struct xdr_netobj name;
488 	struct xdr_netobj princhash = { .len = 0, .data = NULL };
489 
490 	if (child->d_name.len != HEXDIR_LEN - 1) {
491 		printk("%s: illegal name %pd in recovery directory\n",
492 				__func__, child);
493 		/* Keep trying; maybe the others are OK: */
494 		return 0;
495 	}
496 	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
497 	if (!name.data) {
498 		dprintk("%s: failed to allocate memory for name.data!\n",
499 			__func__);
500 		goto out;
501 	}
502 	name.len = HEXDIR_LEN;
503 	if (!nfs4_client_to_reclaim(name, princhash, nn))
504 		kfree(name.data);
505 out:
506 	return 0;
507 }
508 
509 static int
510 nfsd4_recdir_load(struct net *net) {
511 	int status;
512 	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
513 
514 	if (!nn->rec_file)
515 		return 0;
516 
517 	status = nfsd4_list_rec_dir(load_recdir, nn);
518 	if (status)
519 		printk("nfsd4: failed loading clients from recovery"
520 			" directory %pD\n", nn->rec_file);
521 	return status;
522 }
523 
524 /*
525  * Hold reference to the recovery directory.
526  */
527 
528 static int
529 nfsd4_init_recdir(struct net *net)
530 {
531 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
532 	const struct cred *original_cred;
533 	int status;
534 
535 	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
536 			user_recovery_dirname);
537 
538 	BUG_ON(nn->rec_file);
539 
540 	status = nfs4_save_creds(&original_cred);
541 	if (status < 0) {
542 		printk("NFSD: Unable to change credentials to find recovery"
543 		       " directory: error %d\n",
544 		       status);
545 		return status;
546 	}
547 
548 	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
549 	if (IS_ERR(nn->rec_file)) {
550 		printk("NFSD: unable to find recovery directory %s\n",
551 				user_recovery_dirname);
552 		status = PTR_ERR(nn->rec_file);
553 		nn->rec_file = NULL;
554 	}
555 
556 	nfs4_reset_creds(original_cred);
557 	if (!status)
558 		nn->in_grace = true;
559 	return status;
560 }
561 
562 static void
563 nfsd4_shutdown_recdir(struct net *net)
564 {
565 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
566 
567 	if (!nn->rec_file)
568 		return;
569 	fput(nn->rec_file);
570 	nn->rec_file = NULL;
571 }
572 
573 static int
574 nfs4_legacy_state_init(struct net *net)
575 {
576 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
577 	int i;
578 
579 	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
580 						sizeof(struct list_head),
581 						GFP_KERNEL);
582 	if (!nn->reclaim_str_hashtbl)
583 		return -ENOMEM;
584 
585 	for (i = 0; i < CLIENT_HASH_SIZE; i++)
586 		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
587 	nn->reclaim_str_hashtbl_size = 0;
588 
589 	return 0;
590 }
591 
592 static void
593 nfs4_legacy_state_shutdown(struct net *net)
594 {
595 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
596 
597 	kfree(nn->reclaim_str_hashtbl);
598 }
599 
600 static int
601 nfsd4_load_reboot_recovery_data(struct net *net)
602 {
603 	int status;
604 
605 	status = nfsd4_init_recdir(net);
606 	if (status)
607 		return status;
608 
609 	status = nfsd4_recdir_load(net);
610 	if (status)
611 		nfsd4_shutdown_recdir(net);
612 
613 	return status;
614 }
615 
616 static int
617 nfsd4_legacy_tracking_init(struct net *net)
618 {
619 	int status;
620 
621 	/* XXX: The legacy code won't work in a container */
622 	if (net != &init_net) {
623 		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
624 		return -EINVAL;
625 	}
626 
627 	status = nfs4_legacy_state_init(net);
628 	if (status)
629 		return status;
630 
631 	status = nfsd4_load_reboot_recovery_data(net);
632 	if (status)
633 		goto err;
634 	pr_info("NFSD: Using legacy client tracking operations.\n");
635 	return 0;
636 
637 err:
638 	nfs4_legacy_state_shutdown(net);
639 	return status;
640 }
641 
642 static void
643 nfsd4_legacy_tracking_exit(struct net *net)
644 {
645 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
646 
647 	nfs4_release_reclaim(nn);
648 	nfsd4_shutdown_recdir(net);
649 	nfs4_legacy_state_shutdown(net);
650 }
651 
652 /*
653  * Change the NFSv4 recovery directory to recdir.
654  */
655 int
656 nfs4_reset_recoverydir(char *recdir)
657 {
658 	int status;
659 	struct path path;
660 
661 	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
662 	if (status)
663 		return status;
664 	status = -ENOTDIR;
665 	if (d_is_dir(path.dentry)) {
666 		strscpy(user_recovery_dirname, recdir,
667 			sizeof(user_recovery_dirname));
668 		status = 0;
669 	}
670 	path_put(&path);
671 	return status;
672 }
673 
674 char *
675 nfs4_recoverydir(void)
676 {
677 	return user_recovery_dirname;
678 }
679 
680 static int
681 nfsd4_check_legacy_client(struct nfs4_client *clp)
682 {
683 	int status;
684 	char dname[HEXDIR_LEN];
685 	struct nfs4_client_reclaim *crp;
686 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
687 	struct xdr_netobj name;
688 
689 	/* did we already find that this client is stable? */
690 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
691 		return 0;
692 
693 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
694 	if (status) {
695 		legacy_recdir_name_error(clp, status);
696 		return status;
697 	}
698 
699 	/* look for it in the reclaim hashtable otherwise */
700 	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
701 	if (!name.data) {
702 		dprintk("%s: failed to allocate memory for name.data!\n",
703 			__func__);
704 		goto out_enoent;
705 	}
706 	name.len = HEXDIR_LEN;
707 	crp = nfsd4_find_reclaim_client(name, nn);
708 	kfree(name.data);
709 	if (crp) {
710 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
711 		crp->cr_clp = clp;
712 		return 0;
713 	}
714 
715 out_enoent:
716 	return -ENOENT;
717 }
718 
719 static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
720 	.init		= nfsd4_legacy_tracking_init,
721 	.exit		= nfsd4_legacy_tracking_exit,
722 	.create		= nfsd4_create_clid_dir,
723 	.remove		= nfsd4_remove_clid_dir,
724 	.check		= nfsd4_check_legacy_client,
725 	.grace_done	= nfsd4_recdir_purge_old,
726 	.version	= 1,
727 	.msglen		= 0,
728 };
729 #endif /* CONFIG_NFSD_LEGACY_CLIENT_TRACKING */
730 
731 /* Globals */
732 #define NFSD_PIPE_DIR		"nfsd"
733 #define NFSD_CLD_PIPE		"cld"
734 
735 /* per-net-ns structure for holding cld upcall info */
736 struct cld_net {
737 	struct rpc_pipe		*cn_pipe;
738 	spinlock_t		 cn_lock;
739 	struct list_head	 cn_list;
740 	unsigned int		 cn_xid;
741 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
742 	bool			 cn_has_legacy;
743 #endif
744 };
745 
746 struct cld_upcall {
747 	struct list_head	 cu_list;
748 	struct cld_net		*cu_net;
749 	struct completion	 cu_done;
750 	union {
751 		struct cld_msg_hdr	 cu_hdr;
752 		struct cld_msg		 cu_msg;
753 		struct cld_msg_v2	 cu_msg_v2;
754 	} cu_u;
755 };
756 
757 static int
758 __cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
759 {
760 	int ret;
761 	struct rpc_pipe_msg msg;
762 	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
763 
764 	memset(&msg, 0, sizeof(msg));
765 	msg.data = cmsg;
766 	msg.len = nn->client_tracking_ops->msglen;
767 
768 	ret = rpc_queue_upcall(pipe, &msg);
769 	if (ret < 0) {
770 		goto out;
771 	}
772 
773 	wait_for_completion(&cup->cu_done);
774 
775 	if (msg.errno < 0)
776 		ret = msg.errno;
777 out:
778 	return ret;
779 }
780 
781 static int
782 cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
783 {
784 	int ret;
785 
786 	/*
787 	 * -EAGAIN occurs when pipe is closed and reopened while there are
788 	 *  upcalls queued.
789 	 */
790 	do {
791 		ret = __cld_pipe_upcall(pipe, cmsg, nn);
792 	} while (ret == -EAGAIN);
793 
794 	return ret;
795 }
796 
797 static ssize_t
798 __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
799 		struct nfsd_net *nn)
800 {
801 	uint8_t cmd, princhashlen;
802 	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
803 	uint16_t namelen;
804 
805 	if (get_user(cmd, &cmsg->cm_cmd)) {
806 		dprintk("%s: error when copying cmd from userspace", __func__);
807 		return -EFAULT;
808 	}
809 	if (cmd == Cld_GraceStart) {
810 		if (nn->client_tracking_ops->version >= 2) {
811 			const struct cld_clntinfo __user *ci;
812 
813 			ci = &cmsg->cm_u.cm_clntinfo;
814 			if (get_user(namelen, &ci->cc_name.cn_len))
815 				return -EFAULT;
816 			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
817 				dprintk("%s: invalid namelen (%u)", __func__, namelen);
818 				return -EINVAL;
819 			}
820 			name.data = memdup_user(&ci->cc_name.cn_id, namelen);
821 			if (IS_ERR(name.data))
822 				return PTR_ERR(name.data);
823 			name.len = namelen;
824 			get_user(princhashlen, &ci->cc_princhash.cp_len);
825 			if (princhashlen > 0) {
826 				princhash.data = memdup_user(
827 						&ci->cc_princhash.cp_data,
828 						princhashlen);
829 				if (IS_ERR(princhash.data)) {
830 					kfree(name.data);
831 					return PTR_ERR(princhash.data);
832 				}
833 				princhash.len = princhashlen;
834 			} else
835 				princhash.len = 0;
836 		} else {
837 			const struct cld_name __user *cnm;
838 
839 			cnm = &cmsg->cm_u.cm_name;
840 			if (get_user(namelen, &cnm->cn_len))
841 				return -EFAULT;
842 			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
843 				dprintk("%s: invalid namelen (%u)", __func__, namelen);
844 				return -EINVAL;
845 			}
846 			name.data = memdup_user(&cnm->cn_id, namelen);
847 			if (IS_ERR(name.data))
848 				return PTR_ERR(name.data);
849 			name.len = namelen;
850 		}
851 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
852 		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
853 			struct cld_net *cn = nn->cld_net;
854 
855 			name.len = name.len - 5;
856 			memmove(name.data, name.data + 5, name.len);
857 			cn->cn_has_legacy = true;
858 		}
859 #endif
860 		if (!nfs4_client_to_reclaim(name, princhash, nn)) {
861 			kfree(name.data);
862 			kfree(princhash.data);
863 			return -EFAULT;
864 		}
865 		return nn->client_tracking_ops->msglen;
866 	}
867 	return -EFAULT;
868 }
869 
870 static ssize_t
871 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
872 {
873 	struct cld_upcall *tmp, *cup;
874 	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
875 	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
876 	uint32_t xid;
877 	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
878 						nfsd_net_id);
879 	struct cld_net *cn = nn->cld_net;
880 	int16_t status;
881 
882 	if (mlen != nn->client_tracking_ops->msglen) {
883 		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
884 			nn->client_tracking_ops->msglen);
885 		return -EINVAL;
886 	}
887 
888 	/* copy just the xid so we can try to find that */
889 	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
890 		dprintk("%s: error when copying xid from userspace", __func__);
891 		return -EFAULT;
892 	}
893 
894 	/*
895 	 * copy the status so we know whether to remove the upcall from the
896 	 * list (for -EINPROGRESS, we just want to make sure the xid is
897 	 * valid, not remove the upcall from the list)
898 	 */
899 	if (get_user(status, &hdr->cm_status)) {
900 		dprintk("%s: error when copying status from userspace", __func__);
901 		return -EFAULT;
902 	}
903 
904 	/* walk the list and find corresponding xid */
905 	cup = NULL;
906 	spin_lock(&cn->cn_lock);
907 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
908 		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
909 			cup = tmp;
910 			if (status != -EINPROGRESS)
911 				list_del_init(&cup->cu_list);
912 			break;
913 		}
914 	}
915 	spin_unlock(&cn->cn_lock);
916 
917 	/* couldn't find upcall? */
918 	if (!cup) {
919 		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
920 		return -EINVAL;
921 	}
922 
923 	if (status == -EINPROGRESS)
924 		return __cld_pipe_inprogress_downcall(cmsg, nn);
925 
926 	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
927 		return -EFAULT;
928 
929 	complete(&cup->cu_done);
930 	return mlen;
931 }
932 
933 static void
934 cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
935 {
936 	struct cld_msg *cmsg = msg->data;
937 	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
938 						 cu_u.cu_msg);
939 
940 	/* errno >= 0 means we got a downcall */
941 	if (msg->errno >= 0)
942 		return;
943 
944 	complete(&cup->cu_done);
945 }
946 
947 static const struct rpc_pipe_ops cld_upcall_ops = {
948 	.upcall		= rpc_pipe_generic_upcall,
949 	.downcall	= cld_pipe_downcall,
950 	.destroy_msg	= cld_pipe_destroy_msg,
951 };
952 
953 static struct dentry *
954 nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
955 {
956 	struct dentry *dir, *dentry;
957 
958 	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
959 	if (dir == NULL)
960 		return ERR_PTR(-ENOENT);
961 	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
962 	dput(dir);
963 	return dentry;
964 }
965 
966 static void
967 nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
968 {
969 	if (pipe->dentry)
970 		rpc_unlink(pipe->dentry);
971 }
972 
973 static struct dentry *
974 nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
975 {
976 	struct super_block *sb;
977 	struct dentry *dentry;
978 
979 	sb = rpc_get_sb_net(net);
980 	if (!sb)
981 		return NULL;
982 	dentry = nfsd4_cld_register_sb(sb, pipe);
983 	rpc_put_sb_net(net);
984 	return dentry;
985 }
986 
987 static void
988 nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
989 {
990 	struct super_block *sb;
991 
992 	sb = rpc_get_sb_net(net);
993 	if (sb) {
994 		nfsd4_cld_unregister_sb(pipe);
995 		rpc_put_sb_net(net);
996 	}
997 }
998 
999 /* Initialize rpc_pipefs pipe for communication with client tracking daemon */
1000 static int
1001 __nfsd4_init_cld_pipe(struct net *net)
1002 {
1003 	int ret;
1004 	struct dentry *dentry;
1005 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1006 	struct cld_net *cn;
1007 
1008 	if (nn->cld_net)
1009 		return 0;
1010 
1011 	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
1012 	if (!cn) {
1013 		ret = -ENOMEM;
1014 		goto err;
1015 	}
1016 
1017 	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
1018 	if (IS_ERR(cn->cn_pipe)) {
1019 		ret = PTR_ERR(cn->cn_pipe);
1020 		goto err;
1021 	}
1022 	spin_lock_init(&cn->cn_lock);
1023 	INIT_LIST_HEAD(&cn->cn_list);
1024 
1025 	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
1026 	if (IS_ERR(dentry)) {
1027 		ret = PTR_ERR(dentry);
1028 		goto err_destroy_data;
1029 	}
1030 
1031 	cn->cn_pipe->dentry = dentry;
1032 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1033 	cn->cn_has_legacy = false;
1034 #endif
1035 	nn->cld_net = cn;
1036 	return 0;
1037 
1038 err_destroy_data:
1039 	rpc_destroy_pipe_data(cn->cn_pipe);
1040 err:
1041 	kfree(cn);
1042 	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
1043 			ret);
1044 	return ret;
1045 }
1046 
1047 static int
1048 nfsd4_init_cld_pipe(struct net *net)
1049 {
1050 	int status;
1051 
1052 	status = __nfsd4_init_cld_pipe(net);
1053 	if (!status)
1054 		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
1055 	return status;
1056 }
1057 
1058 static void
1059 nfsd4_remove_cld_pipe(struct net *net)
1060 {
1061 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1062 	struct cld_net *cn = nn->cld_net;
1063 
1064 	nfsd4_cld_unregister_net(net, cn->cn_pipe);
1065 	rpc_destroy_pipe_data(cn->cn_pipe);
1066 	kfree(nn->cld_net);
1067 	nn->cld_net = NULL;
1068 }
1069 
1070 static struct cld_upcall *
1071 alloc_cld_upcall(struct nfsd_net *nn)
1072 {
1073 	struct cld_upcall *new, *tmp;
1074 	struct cld_net *cn = nn->cld_net;
1075 
1076 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1077 	if (!new)
1078 		return new;
1079 
1080 	/* FIXME: hard cap on number in flight? */
1081 restart_search:
1082 	spin_lock(&cn->cn_lock);
1083 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
1084 		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
1085 			cn->cn_xid++;
1086 			spin_unlock(&cn->cn_lock);
1087 			goto restart_search;
1088 		}
1089 	}
1090 	init_completion(&new->cu_done);
1091 	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
1092 	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
1093 	new->cu_net = cn;
1094 	list_add(&new->cu_list, &cn->cn_list);
1095 	spin_unlock(&cn->cn_lock);
1096 
1097 	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
1098 
1099 	return new;
1100 }
1101 
1102 static void
1103 free_cld_upcall(struct cld_upcall *victim)
1104 {
1105 	struct cld_net *cn = victim->cu_net;
1106 
1107 	spin_lock(&cn->cn_lock);
1108 	list_del(&victim->cu_list);
1109 	spin_unlock(&cn->cn_lock);
1110 	kfree(victim);
1111 }
1112 
1113 /* Ask daemon to create a new record */
1114 static void
1115 nfsd4_cld_create(struct nfs4_client *clp)
1116 {
1117 	int ret;
1118 	struct cld_upcall *cup;
1119 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1120 	struct cld_net *cn = nn->cld_net;
1121 
1122 	/* Don't upcall if it's already stored */
1123 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1124 		return;
1125 
1126 	cup = alloc_cld_upcall(nn);
1127 	if (!cup) {
1128 		ret = -ENOMEM;
1129 		goto out_err;
1130 	}
1131 
1132 	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
1133 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1134 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1135 			clp->cl_name.len);
1136 
1137 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1138 	if (!ret) {
1139 		ret = cup->cu_u.cu_msg.cm_status;
1140 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1141 	}
1142 
1143 	free_cld_upcall(cup);
1144 out_err:
1145 	if (ret)
1146 		printk(KERN_ERR "NFSD: Unable to create client "
1147 				"record on stable storage: %d\n", ret);
1148 }
1149 
1150 /* Ask daemon to create a new record */
1151 static void
1152 nfsd4_cld_create_v2(struct nfs4_client *clp)
1153 {
1154 	int ret;
1155 	struct cld_upcall *cup;
1156 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1157 	struct cld_net *cn = nn->cld_net;
1158 	struct cld_msg_v2 *cmsg;
1159 	char *principal = NULL;
1160 
1161 	/* Don't upcall if it's already stored */
1162 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1163 		return;
1164 
1165 	cup = alloc_cld_upcall(nn);
1166 	if (!cup) {
1167 		ret = -ENOMEM;
1168 		goto out_err;
1169 	}
1170 
1171 	cmsg = &cup->cu_u.cu_msg_v2;
1172 	cmsg->cm_cmd = Cld_Create;
1173 	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
1174 	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
1175 			clp->cl_name.len);
1176 	if (clp->cl_cred.cr_raw_principal)
1177 		principal = clp->cl_cred.cr_raw_principal;
1178 	else if (clp->cl_cred.cr_principal)
1179 		principal = clp->cl_cred.cr_principal;
1180 	if (principal) {
1181 		sha256(principal, strlen(principal),
1182 		       cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data);
1183 		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = SHA256_DIGEST_SIZE;
1184 	} else
1185 		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
1186 
1187 	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
1188 	if (!ret) {
1189 		ret = cmsg->cm_status;
1190 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1191 	}
1192 
1193 	free_cld_upcall(cup);
1194 out_err:
1195 	if (ret)
1196 		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
1197 				ret);
1198 }
1199 
1200 /* Ask daemon to create a new record */
1201 static void
1202 nfsd4_cld_remove(struct nfs4_client *clp)
1203 {
1204 	int ret;
1205 	struct cld_upcall *cup;
1206 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1207 	struct cld_net *cn = nn->cld_net;
1208 
1209 	/* Don't upcall if it's already removed */
1210 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1211 		return;
1212 
1213 	cup = alloc_cld_upcall(nn);
1214 	if (!cup) {
1215 		ret = -ENOMEM;
1216 		goto out_err;
1217 	}
1218 
1219 	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
1220 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1221 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1222 			clp->cl_name.len);
1223 
1224 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1225 	if (!ret) {
1226 		ret = cup->cu_u.cu_msg.cm_status;
1227 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1228 	}
1229 
1230 	free_cld_upcall(cup);
1231 out_err:
1232 	if (ret)
1233 		printk(KERN_ERR "NFSD: Unable to remove client "
1234 				"record from stable storage: %d\n", ret);
1235 }
1236 
1237 /*
1238  * For older nfsdcld's that do not allow us to "slurp" the clients
1239  * from the tracking database during startup.
1240  *
1241  * Check for presence of a record, and update its timestamp
1242  */
1243 static int
1244 nfsd4_cld_check_v0(struct nfs4_client *clp)
1245 {
1246 	int ret;
1247 	struct cld_upcall *cup;
1248 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1249 	struct cld_net *cn = nn->cld_net;
1250 
1251 	/* Don't upcall if one was already stored during this grace pd */
1252 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1253 		return 0;
1254 
1255 	cup = alloc_cld_upcall(nn);
1256 	if (!cup) {
1257 		printk(KERN_ERR "NFSD: Unable to check client record on "
1258 				"stable storage: %d\n", -ENOMEM);
1259 		return -ENOMEM;
1260 	}
1261 
1262 	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
1263 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1264 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1265 			clp->cl_name.len);
1266 
1267 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1268 	if (!ret) {
1269 		ret = cup->cu_u.cu_msg.cm_status;
1270 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1271 	}
1272 
1273 	free_cld_upcall(cup);
1274 	return ret;
1275 }
1276 
1277 /*
1278  * For newer nfsdcld's that allow us to "slurp" the clients
1279  * from the tracking database during startup.
1280  *
1281  * Check for presence of a record in the reclaim_str_hashtbl
1282  */
1283 static int
1284 nfsd4_cld_check(struct nfs4_client *clp)
1285 {
1286 	struct nfs4_client_reclaim *crp;
1287 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1288 
1289 	/* did we already find that this client is stable? */
1290 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1291 		return 0;
1292 
1293 	/* look for it in the reclaim hashtable otherwise */
1294 	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1295 	if (crp)
1296 		goto found;
1297 
1298 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1299 	if (nn->cld_net->cn_has_legacy) {
1300 		int status;
1301 		char dname[HEXDIR_LEN];
1302 		struct xdr_netobj name;
1303 
1304 		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1305 		if (status)
1306 			return -ENOENT;
1307 
1308 		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1309 		if (!name.data) {
1310 			dprintk("%s: failed to allocate memory for name.data!\n",
1311 				__func__);
1312 			return -ENOENT;
1313 		}
1314 		name.len = HEXDIR_LEN;
1315 		crp = nfsd4_find_reclaim_client(name, nn);
1316 		kfree(name.data);
1317 		if (crp)
1318 			goto found;
1319 
1320 	}
1321 #endif
1322 	return -ENOENT;
1323 found:
1324 	crp->cr_clp = clp;
1325 	return 0;
1326 }
1327 
1328 static int
1329 nfsd4_cld_check_v2(struct nfs4_client *clp)
1330 {
1331 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1332 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1333 	struct cld_net *cn = nn->cld_net;
1334 #endif
1335 	struct nfs4_client_reclaim *crp;
1336 	char *principal = NULL;
1337 
1338 	/* did we already find that this client is stable? */
1339 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1340 		return 0;
1341 
1342 	/* look for it in the reclaim hashtable otherwise */
1343 	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1344 	if (crp)
1345 		goto found;
1346 
1347 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1348 	if (cn->cn_has_legacy) {
1349 		struct xdr_netobj name;
1350 		char dname[HEXDIR_LEN];
1351 		int status;
1352 
1353 		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1354 		if (status)
1355 			return -ENOENT;
1356 
1357 		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1358 		if (!name.data) {
1359 			dprintk("%s: failed to allocate memory for name.data\n",
1360 					__func__);
1361 			return -ENOENT;
1362 		}
1363 		name.len = HEXDIR_LEN;
1364 		crp = nfsd4_find_reclaim_client(name, nn);
1365 		kfree(name.data);
1366 		if (crp)
1367 			goto found;
1368 
1369 	}
1370 #endif
1371 	return -ENOENT;
1372 found:
1373 	if (crp->cr_princhash.len) {
1374 		u8 digest[SHA256_DIGEST_SIZE];
1375 
1376 		if (clp->cl_cred.cr_raw_principal)
1377 			principal = clp->cl_cred.cr_raw_principal;
1378 		else if (clp->cl_cred.cr_principal)
1379 			principal = clp->cl_cred.cr_principal;
1380 		if (principal == NULL)
1381 			return -ENOENT;
1382 		sha256(principal, strlen(principal), digest);
1383 		if (memcmp(crp->cr_princhash.data, digest,
1384 				crp->cr_princhash.len))
1385 			return -ENOENT;
1386 	}
1387 	crp->cr_clp = clp;
1388 	return 0;
1389 }
1390 
1391 static int
1392 nfsd4_cld_grace_start(struct nfsd_net *nn)
1393 {
1394 	int ret;
1395 	struct cld_upcall *cup;
1396 	struct cld_net *cn = nn->cld_net;
1397 
1398 	cup = alloc_cld_upcall(nn);
1399 	if (!cup) {
1400 		ret = -ENOMEM;
1401 		goto out_err;
1402 	}
1403 
1404 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
1405 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1406 	if (!ret)
1407 		ret = cup->cu_u.cu_msg.cm_status;
1408 
1409 	free_cld_upcall(cup);
1410 out_err:
1411 	if (ret)
1412 		dprintk("%s: Unable to get clients from userspace: %d\n",
1413 			__func__, ret);
1414 	return ret;
1415 }
1416 
1417 /* For older nfsdcld's that need cm_gracetime */
1418 static void
1419 nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
1420 {
1421 	int ret;
1422 	struct cld_upcall *cup;
1423 	struct cld_net *cn = nn->cld_net;
1424 
1425 	cup = alloc_cld_upcall(nn);
1426 	if (!cup) {
1427 		ret = -ENOMEM;
1428 		goto out_err;
1429 	}
1430 
1431 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1432 	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
1433 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1434 	if (!ret)
1435 		ret = cup->cu_u.cu_msg.cm_status;
1436 
1437 	free_cld_upcall(cup);
1438 out_err:
1439 	if (ret)
1440 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1441 }
1442 
1443 /*
1444  * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
1445  * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
1446  */
1447 static void
1448 nfsd4_cld_grace_done(struct nfsd_net *nn)
1449 {
1450 	int ret;
1451 	struct cld_upcall *cup;
1452 	struct cld_net *cn = nn->cld_net;
1453 
1454 	cup = alloc_cld_upcall(nn);
1455 	if (!cup) {
1456 		ret = -ENOMEM;
1457 		goto out_err;
1458 	}
1459 
1460 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1461 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1462 	if (!ret)
1463 		ret = cup->cu_u.cu_msg.cm_status;
1464 
1465 	free_cld_upcall(cup);
1466 out_err:
1467 	nfs4_release_reclaim(nn);
1468 	if (ret)
1469 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1470 }
1471 
1472 static int
1473 nfs4_cld_state_init(struct net *net)
1474 {
1475 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1476 	int i;
1477 
1478 	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
1479 						sizeof(struct list_head),
1480 						GFP_KERNEL);
1481 	if (!nn->reclaim_str_hashtbl)
1482 		return -ENOMEM;
1483 
1484 	for (i = 0; i < CLIENT_HASH_SIZE; i++)
1485 		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
1486 	nn->reclaim_str_hashtbl_size = 0;
1487 	nn->track_reclaim_completes = true;
1488 	atomic_set(&nn->nr_reclaim_complete, 0);
1489 
1490 	return 0;
1491 }
1492 
1493 static void
1494 nfs4_cld_state_shutdown(struct net *net)
1495 {
1496 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1497 
1498 	nn->track_reclaim_completes = false;
1499 	kfree(nn->reclaim_str_hashtbl);
1500 }
1501 
1502 static bool
1503 cld_running(struct nfsd_net *nn)
1504 {
1505 	struct cld_net *cn = nn->cld_net;
1506 	struct rpc_pipe *pipe = cn->cn_pipe;
1507 
1508 	return pipe->nreaders || pipe->nwriters;
1509 }
1510 
1511 static int
1512 nfsd4_cld_get_version(struct nfsd_net *nn)
1513 {
1514 	int ret = 0;
1515 	struct cld_upcall *cup;
1516 	struct cld_net *cn = nn->cld_net;
1517 	uint8_t version;
1518 
1519 	cup = alloc_cld_upcall(nn);
1520 	if (!cup) {
1521 		ret = -ENOMEM;
1522 		goto out_err;
1523 	}
1524 	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
1525 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1526 	if (!ret) {
1527 		ret = cup->cu_u.cu_msg.cm_status;
1528 		if (ret)
1529 			goto out_free;
1530 		version = cup->cu_u.cu_msg.cm_u.cm_version;
1531 		dprintk("%s: userspace returned version %u\n",
1532 				__func__, version);
1533 		if (version < 1)
1534 			version = 1;
1535 		else if (version > CLD_UPCALL_VERSION)
1536 			version = CLD_UPCALL_VERSION;
1537 
1538 		switch (version) {
1539 		case 1:
1540 			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1541 			break;
1542 		case 2:
1543 			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
1544 			break;
1545 		default:
1546 			break;
1547 		}
1548 	}
1549 out_free:
1550 	free_cld_upcall(cup);
1551 out_err:
1552 	if (ret)
1553 		dprintk("%s: Unable to get version from userspace: %d\n",
1554 			__func__, ret);
1555 	return ret;
1556 }
1557 
1558 static int
1559 nfsd4_cld_tracking_init(struct net *net)
1560 {
1561 	int status;
1562 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1563 	bool running;
1564 	int retries = 10;
1565 
1566 	status = nfs4_cld_state_init(net);
1567 	if (status)
1568 		return status;
1569 
1570 	status = __nfsd4_init_cld_pipe(net);
1571 	if (status)
1572 		goto err_shutdown;
1573 
1574 	/*
1575 	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
1576 	 * queue an upcall unless we know that nfsdcld is running (because we
1577 	 * want this to fail fast so that nfsd4_client_tracking_init() can try
1578 	 * the next client tracking method).  nfsdcld should already be running
1579 	 * before nfsd is started, so the wait here is for nfsdcld to open the
1580 	 * pipefs file we just created.
1581 	 */
1582 	while (!(running = cld_running(nn)) && retries--)
1583 		msleep(100);
1584 
1585 	if (!running) {
1586 		status = -ETIMEDOUT;
1587 		goto err_remove;
1588 	}
1589 
1590 	status = nfsd4_cld_get_version(nn);
1591 	if (status == -EOPNOTSUPP)
1592 		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
1593 
1594 	status = nfsd4_cld_grace_start(nn);
1595 	if (status) {
1596 		if (status == -EOPNOTSUPP)
1597 			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
1598 		nfs4_release_reclaim(nn);
1599 		goto err_remove;
1600 	} else
1601 		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
1602 	return 0;
1603 
1604 err_remove:
1605 	nfsd4_remove_cld_pipe(net);
1606 err_shutdown:
1607 	nfs4_cld_state_shutdown(net);
1608 	return status;
1609 }
1610 
1611 static void
1612 nfsd4_cld_tracking_exit(struct net *net)
1613 {
1614 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1615 
1616 	nfs4_release_reclaim(nn);
1617 	nfsd4_remove_cld_pipe(net);
1618 	nfs4_cld_state_shutdown(net);
1619 }
1620 
1621 /* For older nfsdcld's */
1622 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
1623 	.init		= nfsd4_init_cld_pipe,
1624 	.exit		= nfsd4_remove_cld_pipe,
1625 	.create		= nfsd4_cld_create,
1626 	.remove		= nfsd4_cld_remove,
1627 	.check		= nfsd4_cld_check_v0,
1628 	.grace_done	= nfsd4_cld_grace_done_v0,
1629 	.version	= 1,
1630 	.msglen		= sizeof(struct cld_msg),
1631 };
1632 
1633 /* For newer nfsdcld's */
1634 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1635 	.init		= nfsd4_cld_tracking_init,
1636 	.exit		= nfsd4_cld_tracking_exit,
1637 	.create		= nfsd4_cld_create,
1638 	.remove		= nfsd4_cld_remove,
1639 	.check		= nfsd4_cld_check,
1640 	.grace_done	= nfsd4_cld_grace_done,
1641 	.version	= 1,
1642 	.msglen		= sizeof(struct cld_msg),
1643 };
1644 
1645 /* v2 create/check ops include the principal, if available */
1646 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
1647 	.init		= nfsd4_cld_tracking_init,
1648 	.exit		= nfsd4_cld_tracking_exit,
1649 	.create		= nfsd4_cld_create_v2,
1650 	.remove		= nfsd4_cld_remove,
1651 	.check		= nfsd4_cld_check_v2,
1652 	.grace_done	= nfsd4_cld_grace_done,
1653 	.version	= 2,
1654 	.msglen		= sizeof(struct cld_msg_v2),
1655 };
1656 
1657 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1658 /* upcall via usermodehelper */
1659 static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1660 module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1661 			S_IRUGO|S_IWUSR);
1662 MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1663 
1664 static bool cltrack_legacy_disable;
1665 module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1666 MODULE_PARM_DESC(cltrack_legacy_disable,
1667 		"Disable legacy recoverydir conversion. Default: false");
1668 
1669 #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1670 #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1671 #define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1672 #define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1673 
1674 static char *
1675 nfsd4_cltrack_legacy_topdir(void)
1676 {
1677 	int copied;
1678 	size_t len;
1679 	char *result;
1680 
1681 	if (cltrack_legacy_disable)
1682 		return NULL;
1683 
1684 	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1685 		strlen(nfs4_recoverydir()) + 1;
1686 
1687 	result = kmalloc(len, GFP_KERNEL);
1688 	if (!result)
1689 		return result;
1690 
1691 	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1692 				nfs4_recoverydir());
1693 	if (copied >= len) {
1694 		/* just return nothing if output was truncated */
1695 		kfree(result);
1696 		return NULL;
1697 	}
1698 
1699 	return result;
1700 }
1701 
1702 static char *
1703 nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1704 {
1705 	int copied;
1706 	size_t len;
1707 	char *result;
1708 
1709 	if (cltrack_legacy_disable)
1710 		return NULL;
1711 
1712 	/* +1 is for '/' between "topdir" and "recdir" */
1713 	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1714 		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1715 
1716 	result = kmalloc(len, GFP_KERNEL);
1717 	if (!result)
1718 		return result;
1719 
1720 	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1721 				nfs4_recoverydir());
1722 	if (copied > (len - HEXDIR_LEN)) {
1723 		/* just return nothing if output will be truncated */
1724 		kfree(result);
1725 		return NULL;
1726 	}
1727 
1728 	copied = nfs4_make_rec_clidname(result + copied, name);
1729 	if (copied) {
1730 		kfree(result);
1731 		return NULL;
1732 	}
1733 
1734 	return result;
1735 }
1736 
1737 static char *
1738 nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1739 {
1740 	int copied;
1741 	size_t len;
1742 	char *result;
1743 
1744 	/* prefix + Y/N character + terminating NULL */
1745 	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1746 
1747 	result = kmalloc(len, GFP_KERNEL);
1748 	if (!result)
1749 		return result;
1750 
1751 	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1752 				clp->cl_minorversion ? 'Y' : 'N');
1753 	if (copied >= len) {
1754 		/* just return nothing if output was truncated */
1755 		kfree(result);
1756 		return NULL;
1757 	}
1758 
1759 	return result;
1760 }
1761 
1762 static char *
1763 nfsd4_cltrack_grace_start(time64_t grace_start)
1764 {
1765 	int copied;
1766 	size_t len;
1767 	char *result;
1768 
1769 	/* prefix + max width of int64_t string + terminating NULL */
1770 	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1771 
1772 	result = kmalloc(len, GFP_KERNEL);
1773 	if (!result)
1774 		return result;
1775 
1776 	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
1777 				grace_start);
1778 	if (copied >= len) {
1779 		/* just return nothing if output was truncated */
1780 		kfree(result);
1781 		return NULL;
1782 	}
1783 
1784 	return result;
1785 }
1786 
1787 static int
1788 nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1789 {
1790 	char *envp[3];
1791 	char *argv[4];
1792 	int ret;
1793 
1794 	if (unlikely(!cltrack_prog[0])) {
1795 		dprintk("%s: cltrack_prog is disabled\n", __func__);
1796 		return -EACCES;
1797 	}
1798 
1799 	dprintk("%s: cmd: %s\n", __func__, cmd);
1800 	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1801 	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1802 	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1803 
1804 	envp[0] = env0;
1805 	envp[1] = env1;
1806 	envp[2] = NULL;
1807 
1808 	argv[0] = (char *)cltrack_prog;
1809 	argv[1] = cmd;
1810 	argv[2] = arg;
1811 	argv[3] = NULL;
1812 
1813 	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1814 	/*
1815 	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1816 	 * error. The admin can re-enable it on the fly by using sysfs
1817 	 * once the problem has been fixed.
1818 	 */
1819 	if (ret == -ENOENT || ret == -EACCES) {
1820 		dprintk("NFSD: %s was not found or isn't executable (%d). "
1821 			"Setting cltrack_prog to blank string!",
1822 			cltrack_prog, ret);
1823 		cltrack_prog[0] = '\0';
1824 	}
1825 	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1826 
1827 	return ret;
1828 }
1829 
1830 static char *
1831 bin_to_hex_dup(const unsigned char *src, int srclen)
1832 {
1833 	char *buf;
1834 
1835 	/* +1 for terminating NULL */
1836 	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
1837 	if (!buf)
1838 		return buf;
1839 
1840 	bin2hex(buf, src, srclen);
1841 	return buf;
1842 }
1843 
1844 static int
1845 nfsd4_umh_cltrack_init(struct net *net)
1846 {
1847 	int ret;
1848 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1849 	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1850 
1851 	/* XXX: The usermode helper s not working in container yet. */
1852 	if (net != &init_net) {
1853 		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1854 		kfree(grace_start);
1855 		return -EINVAL;
1856 	}
1857 
1858 	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1859 	kfree(grace_start);
1860 	if (!ret)
1861 		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
1862 	return ret;
1863 }
1864 
1865 static void
1866 nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1867 {
1868 	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1869 			 TASK_UNINTERRUPTIBLE);
1870 }
1871 
1872 static void
1873 nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1874 {
1875 	clear_and_wake_up_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1876 }
1877 
1878 static void
1879 nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1880 {
1881 	char *hexid, *has_session, *grace_start;
1882 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1883 
1884 	/*
1885 	 * With v4.0 clients, there's little difference in outcome between a
1886 	 * create and check operation, and we can end up calling into this
1887 	 * function multiple times per client (once for each openowner). So,
1888 	 * for v4.0 clients skip upcalling once the client has been recorded
1889 	 * on stable storage.
1890 	 *
1891 	 * For v4.1+ clients, the outcome of the two operations is different,
1892 	 * so we must ensure that we upcall for the create operation. v4.1+
1893 	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1894 	 * up doing a single create upcall per client.
1895 	 */
1896 	if (clp->cl_minorversion == 0 &&
1897 	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1898 		return;
1899 
1900 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1901 	if (!hexid) {
1902 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1903 		return;
1904 	}
1905 
1906 	has_session = nfsd4_cltrack_client_has_session(clp);
1907 	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1908 
1909 	nfsd4_cltrack_upcall_lock(clp);
1910 	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1911 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1912 	nfsd4_cltrack_upcall_unlock(clp);
1913 
1914 	kfree(has_session);
1915 	kfree(grace_start);
1916 	kfree(hexid);
1917 }
1918 
1919 static void
1920 nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1921 {
1922 	char *hexid;
1923 
1924 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1925 		return;
1926 
1927 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1928 	if (!hexid) {
1929 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1930 		return;
1931 	}
1932 
1933 	nfsd4_cltrack_upcall_lock(clp);
1934 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1935 	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1936 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1937 	nfsd4_cltrack_upcall_unlock(clp);
1938 
1939 	kfree(hexid);
1940 }
1941 
1942 static int
1943 nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1944 {
1945 	int ret;
1946 	char *hexid, *has_session, *legacy;
1947 
1948 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1949 		return 0;
1950 
1951 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1952 	if (!hexid) {
1953 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1954 		return -ENOMEM;
1955 	}
1956 
1957 	has_session = nfsd4_cltrack_client_has_session(clp);
1958 	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1959 
1960 	nfsd4_cltrack_upcall_lock(clp);
1961 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1962 		ret = 0;
1963 	} else {
1964 		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1965 		if (ret == 0)
1966 			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1967 	}
1968 	nfsd4_cltrack_upcall_unlock(clp);
1969 	kfree(has_session);
1970 	kfree(legacy);
1971 	kfree(hexid);
1972 
1973 	return ret;
1974 }
1975 
1976 static void
1977 nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
1978 {
1979 	char *legacy;
1980 	char timestr[22]; /* FIXME: better way to determine max size? */
1981 
1982 	sprintf(timestr, "%lld", nn->boot_time);
1983 	legacy = nfsd4_cltrack_legacy_topdir();
1984 	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
1985 	kfree(legacy);
1986 }
1987 
1988 static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1989 	.init		= nfsd4_umh_cltrack_init,
1990 	.exit		= NULL,
1991 	.create		= nfsd4_umh_cltrack_create,
1992 	.remove		= nfsd4_umh_cltrack_remove,
1993 	.check		= nfsd4_umh_cltrack_check,
1994 	.grace_done	= nfsd4_umh_cltrack_grace_done,
1995 	.version	= 1,
1996 	.msglen		= 0,
1997 };
1998 
1999 static inline int check_for_legacy_methods(int status, struct net *net)
2000 {
2001 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2002 	struct path path;
2003 
2004 	/*
2005 	 * Next, try the UMH upcall.
2006 	 */
2007 	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
2008 	status = nn->client_tracking_ops->init(net);
2009 	if (!status)
2010 		return status;
2011 
2012 	/*
2013 	 * Finally, See if the recoverydir exists and is a directory.
2014 	 * If it is, then use the legacy ops.
2015 	 */
2016 	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
2017 	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
2018 	if (!status) {
2019 		status = !d_is_dir(path.dentry);
2020 		path_put(&path);
2021 		if (status)
2022 			return -ENOTDIR;
2023 	}
2024 	return status;
2025 }
2026 #else
2027 static inline int check_for_legacy_methods(int status, struct net *net)
2028 {
2029 	return status;
2030 }
2031 #endif /* CONFIG_LEGACY_NFSD_CLIENT_TRACKING */
2032 
2033 int
2034 nfsd4_client_tracking_init(struct net *net)
2035 {
2036 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2037 	int status;
2038 
2039 	/* just run the init if it the method is already decided */
2040 	if (nn->client_tracking_ops)
2041 		goto do_init;
2042 
2043 	/* First, try to use nfsdcld */
2044 	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
2045 	status = nn->client_tracking_ops->init(net);
2046 	if (!status)
2047 		return status;
2048 	if (status != -ETIMEDOUT) {
2049 		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
2050 		status = nn->client_tracking_ops->init(net);
2051 		if (!status)
2052 			return status;
2053 	}
2054 
2055 	status = check_for_legacy_methods(status, net);
2056 	if (status)
2057 		goto out;
2058 do_init:
2059 	status = nn->client_tracking_ops->init(net);
2060 out:
2061 	if (status) {
2062 		pr_warn("NFSD: Unable to initialize client recovery tracking! (%d)\n", status);
2063 		pr_warn("NFSD: Is nfsdcld running? If not, enable CONFIG_NFSD_LEGACY_CLIENT_TRACKING.\n");
2064 		nn->client_tracking_ops = NULL;
2065 	}
2066 	return status;
2067 }
2068 
2069 void
2070 nfsd4_client_tracking_exit(struct net *net)
2071 {
2072 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2073 
2074 	if (nn->client_tracking_ops) {
2075 		if (nn->client_tracking_ops->exit)
2076 			nn->client_tracking_ops->exit(net);
2077 		nn->client_tracking_ops = NULL;
2078 	}
2079 }
2080 
2081 void
2082 nfsd4_client_record_create(struct nfs4_client *clp)
2083 {
2084 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2085 
2086 	if (nn->client_tracking_ops)
2087 		nn->client_tracking_ops->create(clp);
2088 }
2089 
2090 void
2091 nfsd4_client_record_remove(struct nfs4_client *clp)
2092 {
2093 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2094 
2095 	if (nn->client_tracking_ops)
2096 		nn->client_tracking_ops->remove(clp);
2097 }
2098 
2099 int
2100 nfsd4_client_record_check(struct nfs4_client *clp)
2101 {
2102 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2103 
2104 	if (nn->client_tracking_ops)
2105 		return nn->client_tracking_ops->check(clp);
2106 
2107 	return -EOPNOTSUPP;
2108 }
2109 
2110 void
2111 nfsd4_record_grace_done(struct nfsd_net *nn)
2112 {
2113 	if (nn->client_tracking_ops)
2114 		nn->client_tracking_ops->grace_done(nn);
2115 }
2116 
2117 static int
2118 rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
2119 {
2120 	struct super_block *sb = ptr;
2121 	struct net *net = sb->s_fs_info;
2122 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2123 	struct cld_net *cn = nn->cld_net;
2124 	struct dentry *dentry;
2125 	int ret = 0;
2126 
2127 	if (!try_module_get(THIS_MODULE))
2128 		return 0;
2129 
2130 	if (!cn) {
2131 		module_put(THIS_MODULE);
2132 		return 0;
2133 	}
2134 
2135 	switch (event) {
2136 	case RPC_PIPEFS_MOUNT:
2137 		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
2138 		if (IS_ERR(dentry)) {
2139 			ret = PTR_ERR(dentry);
2140 			break;
2141 		}
2142 		cn->cn_pipe->dentry = dentry;
2143 		break;
2144 	case RPC_PIPEFS_UMOUNT:
2145 		if (cn->cn_pipe->dentry)
2146 			nfsd4_cld_unregister_sb(cn->cn_pipe);
2147 		break;
2148 	default:
2149 		ret = -ENOTSUPP;
2150 		break;
2151 	}
2152 	module_put(THIS_MODULE);
2153 	return ret;
2154 }
2155 
2156 static struct notifier_block nfsd4_cld_block = {
2157 	.notifier_call = rpc_pipefs_event,
2158 };
2159 
2160 int
2161 register_cld_notifier(void)
2162 {
2163 	WARN_ON(!nfsd_net_id);
2164 	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
2165 }
2166 
2167 void
2168 unregister_cld_notifier(void)
2169 {
2170 	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
2171 }
2172