xref: /linux/fs/nfsd/nfs4recover.c (revision 55f1b540d893da740a81200450014c45a8103f54)
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 			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
813 				dprintk("%s: invalid namelen (%u)", __func__, namelen);
814 				return -EINVAL;
815 			}
816 			name.data = memdup_user(&ci->cc_name.cn_id, namelen);
817 			if (IS_ERR(name.data))
818 				return PTR_ERR(name.data);
819 			name.len = namelen;
820 			get_user(princhashlen, &ci->cc_princhash.cp_len);
821 			if (princhashlen > 0) {
822 				princhash.data = memdup_user(
823 						&ci->cc_princhash.cp_data,
824 						princhashlen);
825 				if (IS_ERR(princhash.data)) {
826 					kfree(name.data);
827 					return PTR_ERR(princhash.data);
828 				}
829 				princhash.len = princhashlen;
830 			} else
831 				princhash.len = 0;
832 		} else {
833 			const struct cld_name __user *cnm;
834 
835 			cnm = &cmsg->cm_u.cm_name;
836 			if (get_user(namelen, &cnm->cn_len))
837 				return -EFAULT;
838 			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
839 				dprintk("%s: invalid namelen (%u)", __func__, namelen);
840 				return -EINVAL;
841 			}
842 			name.data = memdup_user(&cnm->cn_id, namelen);
843 			if (IS_ERR(name.data))
844 				return PTR_ERR(name.data);
845 			name.len = namelen;
846 		}
847 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
848 		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
849 			struct cld_net *cn = nn->cld_net;
850 
851 			name.len = name.len - 5;
852 			memmove(name.data, name.data + 5, name.len);
853 			cn->cn_has_legacy = true;
854 		}
855 #endif
856 		if (!nfs4_client_to_reclaim(name, princhash, nn)) {
857 			kfree(name.data);
858 			kfree(princhash.data);
859 			return -EFAULT;
860 		}
861 		return nn->client_tracking_ops->msglen;
862 	}
863 	return -EFAULT;
864 }
865 
866 static ssize_t
867 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
868 {
869 	struct cld_upcall *tmp, *cup;
870 	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
871 	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
872 	uint32_t xid;
873 	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
874 						nfsd_net_id);
875 	struct cld_net *cn = nn->cld_net;
876 	int16_t status;
877 
878 	if (mlen != nn->client_tracking_ops->msglen) {
879 		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
880 			nn->client_tracking_ops->msglen);
881 		return -EINVAL;
882 	}
883 
884 	/* copy just the xid so we can try to find that */
885 	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
886 		dprintk("%s: error when copying xid from userspace", __func__);
887 		return -EFAULT;
888 	}
889 
890 	/*
891 	 * copy the status so we know whether to remove the upcall from the
892 	 * list (for -EINPROGRESS, we just want to make sure the xid is
893 	 * valid, not remove the upcall from the list)
894 	 */
895 	if (get_user(status, &hdr->cm_status)) {
896 		dprintk("%s: error when copying status from userspace", __func__);
897 		return -EFAULT;
898 	}
899 
900 	/* walk the list and find corresponding xid */
901 	cup = NULL;
902 	spin_lock(&cn->cn_lock);
903 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
904 		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
905 			cup = tmp;
906 			if (status != -EINPROGRESS)
907 				list_del_init(&cup->cu_list);
908 			break;
909 		}
910 	}
911 	spin_unlock(&cn->cn_lock);
912 
913 	/* couldn't find upcall? */
914 	if (!cup) {
915 		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
916 		return -EINVAL;
917 	}
918 
919 	if (status == -EINPROGRESS)
920 		return __cld_pipe_inprogress_downcall(cmsg, nn);
921 
922 	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
923 		return -EFAULT;
924 
925 	complete(&cup->cu_done);
926 	return mlen;
927 }
928 
929 static void
930 cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
931 {
932 	struct cld_msg *cmsg = msg->data;
933 	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
934 						 cu_u.cu_msg);
935 
936 	/* errno >= 0 means we got a downcall */
937 	if (msg->errno >= 0)
938 		return;
939 
940 	complete(&cup->cu_done);
941 }
942 
943 static const struct rpc_pipe_ops cld_upcall_ops = {
944 	.upcall		= rpc_pipe_generic_upcall,
945 	.downcall	= cld_pipe_downcall,
946 	.destroy_msg	= cld_pipe_destroy_msg,
947 };
948 
949 static struct dentry *
950 nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
951 {
952 	struct dentry *dir, *dentry;
953 
954 	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
955 	if (dir == NULL)
956 		return ERR_PTR(-ENOENT);
957 	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
958 	dput(dir);
959 	return dentry;
960 }
961 
962 static void
963 nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
964 {
965 	if (pipe->dentry)
966 		rpc_unlink(pipe->dentry);
967 }
968 
969 static struct dentry *
970 nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
971 {
972 	struct super_block *sb;
973 	struct dentry *dentry;
974 
975 	sb = rpc_get_sb_net(net);
976 	if (!sb)
977 		return NULL;
978 	dentry = nfsd4_cld_register_sb(sb, pipe);
979 	rpc_put_sb_net(net);
980 	return dentry;
981 }
982 
983 static void
984 nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
985 {
986 	struct super_block *sb;
987 
988 	sb = rpc_get_sb_net(net);
989 	if (sb) {
990 		nfsd4_cld_unregister_sb(pipe);
991 		rpc_put_sb_net(net);
992 	}
993 }
994 
995 /* Initialize rpc_pipefs pipe for communication with client tracking daemon */
996 static int
997 __nfsd4_init_cld_pipe(struct net *net)
998 {
999 	int ret;
1000 	struct dentry *dentry;
1001 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1002 	struct cld_net *cn;
1003 
1004 	if (nn->cld_net)
1005 		return 0;
1006 
1007 	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
1008 	if (!cn) {
1009 		ret = -ENOMEM;
1010 		goto err;
1011 	}
1012 
1013 	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
1014 	if (IS_ERR(cn->cn_pipe)) {
1015 		ret = PTR_ERR(cn->cn_pipe);
1016 		goto err;
1017 	}
1018 	spin_lock_init(&cn->cn_lock);
1019 	INIT_LIST_HEAD(&cn->cn_list);
1020 
1021 	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
1022 	if (IS_ERR(dentry)) {
1023 		ret = PTR_ERR(dentry);
1024 		goto err_destroy_data;
1025 	}
1026 
1027 	cn->cn_pipe->dentry = dentry;
1028 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1029 	cn->cn_has_legacy = false;
1030 #endif
1031 	nn->cld_net = cn;
1032 	return 0;
1033 
1034 err_destroy_data:
1035 	rpc_destroy_pipe_data(cn->cn_pipe);
1036 err:
1037 	kfree(cn);
1038 	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
1039 			ret);
1040 	return ret;
1041 }
1042 
1043 static int
1044 nfsd4_init_cld_pipe(struct net *net)
1045 {
1046 	int status;
1047 
1048 	status = __nfsd4_init_cld_pipe(net);
1049 	if (!status)
1050 		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
1051 	return status;
1052 }
1053 
1054 static void
1055 nfsd4_remove_cld_pipe(struct net *net)
1056 {
1057 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1058 	struct cld_net *cn = nn->cld_net;
1059 
1060 	nfsd4_cld_unregister_net(net, cn->cn_pipe);
1061 	rpc_destroy_pipe_data(cn->cn_pipe);
1062 	if (cn->cn_tfm)
1063 		crypto_free_shash(cn->cn_tfm);
1064 	kfree(nn->cld_net);
1065 	nn->cld_net = NULL;
1066 }
1067 
1068 static struct cld_upcall *
1069 alloc_cld_upcall(struct nfsd_net *nn)
1070 {
1071 	struct cld_upcall *new, *tmp;
1072 	struct cld_net *cn = nn->cld_net;
1073 
1074 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1075 	if (!new)
1076 		return new;
1077 
1078 	/* FIXME: hard cap on number in flight? */
1079 restart_search:
1080 	spin_lock(&cn->cn_lock);
1081 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
1082 		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
1083 			cn->cn_xid++;
1084 			spin_unlock(&cn->cn_lock);
1085 			goto restart_search;
1086 		}
1087 	}
1088 	init_completion(&new->cu_done);
1089 	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
1090 	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
1091 	new->cu_net = cn;
1092 	list_add(&new->cu_list, &cn->cn_list);
1093 	spin_unlock(&cn->cn_lock);
1094 
1095 	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
1096 
1097 	return new;
1098 }
1099 
1100 static void
1101 free_cld_upcall(struct cld_upcall *victim)
1102 {
1103 	struct cld_net *cn = victim->cu_net;
1104 
1105 	spin_lock(&cn->cn_lock);
1106 	list_del(&victim->cu_list);
1107 	spin_unlock(&cn->cn_lock);
1108 	kfree(victim);
1109 }
1110 
1111 /* Ask daemon to create a new record */
1112 static void
1113 nfsd4_cld_create(struct nfs4_client *clp)
1114 {
1115 	int ret;
1116 	struct cld_upcall *cup;
1117 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1118 	struct cld_net *cn = nn->cld_net;
1119 
1120 	/* Don't upcall if it's already stored */
1121 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1122 		return;
1123 
1124 	cup = alloc_cld_upcall(nn);
1125 	if (!cup) {
1126 		ret = -ENOMEM;
1127 		goto out_err;
1128 	}
1129 
1130 	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
1131 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1132 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1133 			clp->cl_name.len);
1134 
1135 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1136 	if (!ret) {
1137 		ret = cup->cu_u.cu_msg.cm_status;
1138 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1139 	}
1140 
1141 	free_cld_upcall(cup);
1142 out_err:
1143 	if (ret)
1144 		printk(KERN_ERR "NFSD: Unable to create client "
1145 				"record on stable storage: %d\n", ret);
1146 }
1147 
1148 /* Ask daemon to create a new record */
1149 static void
1150 nfsd4_cld_create_v2(struct nfs4_client *clp)
1151 {
1152 	int ret;
1153 	struct cld_upcall *cup;
1154 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1155 	struct cld_net *cn = nn->cld_net;
1156 	struct cld_msg_v2 *cmsg;
1157 	struct crypto_shash *tfm = cn->cn_tfm;
1158 	struct xdr_netobj cksum;
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 		cksum.len = crypto_shash_digestsize(tfm);
1182 		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1183 		if (cksum.data == NULL) {
1184 			ret = -ENOMEM;
1185 			goto out;
1186 		}
1187 		ret = crypto_shash_tfm_digest(tfm, principal, strlen(principal),
1188 					      cksum.data);
1189 		if (ret) {
1190 			kfree(cksum.data);
1191 			goto out;
1192 		}
1193 		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = cksum.len;
1194 		memcpy(cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data,
1195 		       cksum.data, cksum.len);
1196 		kfree(cksum.data);
1197 	} else
1198 		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
1199 
1200 	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
1201 	if (!ret) {
1202 		ret = cmsg->cm_status;
1203 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1204 	}
1205 
1206 out:
1207 	free_cld_upcall(cup);
1208 out_err:
1209 	if (ret)
1210 		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
1211 				ret);
1212 }
1213 
1214 /* Ask daemon to create a new record */
1215 static void
1216 nfsd4_cld_remove(struct nfs4_client *clp)
1217 {
1218 	int ret;
1219 	struct cld_upcall *cup;
1220 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1221 	struct cld_net *cn = nn->cld_net;
1222 
1223 	/* Don't upcall if it's already removed */
1224 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1225 		return;
1226 
1227 	cup = alloc_cld_upcall(nn);
1228 	if (!cup) {
1229 		ret = -ENOMEM;
1230 		goto out_err;
1231 	}
1232 
1233 	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
1234 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1235 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1236 			clp->cl_name.len);
1237 
1238 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1239 	if (!ret) {
1240 		ret = cup->cu_u.cu_msg.cm_status;
1241 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1242 	}
1243 
1244 	free_cld_upcall(cup);
1245 out_err:
1246 	if (ret)
1247 		printk(KERN_ERR "NFSD: Unable to remove client "
1248 				"record from stable storage: %d\n", ret);
1249 }
1250 
1251 /*
1252  * For older nfsdcld's that do not allow us to "slurp" the clients
1253  * from the tracking database during startup.
1254  *
1255  * Check for presence of a record, and update its timestamp
1256  */
1257 static int
1258 nfsd4_cld_check_v0(struct nfs4_client *clp)
1259 {
1260 	int ret;
1261 	struct cld_upcall *cup;
1262 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1263 	struct cld_net *cn = nn->cld_net;
1264 
1265 	/* Don't upcall if one was already stored during this grace pd */
1266 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1267 		return 0;
1268 
1269 	cup = alloc_cld_upcall(nn);
1270 	if (!cup) {
1271 		printk(KERN_ERR "NFSD: Unable to check client record on "
1272 				"stable storage: %d\n", -ENOMEM);
1273 		return -ENOMEM;
1274 	}
1275 
1276 	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
1277 	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1278 	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1279 			clp->cl_name.len);
1280 
1281 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1282 	if (!ret) {
1283 		ret = cup->cu_u.cu_msg.cm_status;
1284 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1285 	}
1286 
1287 	free_cld_upcall(cup);
1288 	return ret;
1289 }
1290 
1291 /*
1292  * For newer nfsdcld's that allow us to "slurp" the clients
1293  * from the tracking database during startup.
1294  *
1295  * Check for presence of a record in the reclaim_str_hashtbl
1296  */
1297 static int
1298 nfsd4_cld_check(struct nfs4_client *clp)
1299 {
1300 	struct nfs4_client_reclaim *crp;
1301 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1302 
1303 	/* did we already find that this client is stable? */
1304 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1305 		return 0;
1306 
1307 	/* look for it in the reclaim hashtable otherwise */
1308 	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1309 	if (crp)
1310 		goto found;
1311 
1312 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1313 	if (nn->cld_net->cn_has_legacy) {
1314 		int status;
1315 		char dname[HEXDIR_LEN];
1316 		struct xdr_netobj name;
1317 
1318 		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1319 		if (status)
1320 			return -ENOENT;
1321 
1322 		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1323 		if (!name.data) {
1324 			dprintk("%s: failed to allocate memory for name.data!\n",
1325 				__func__);
1326 			return -ENOENT;
1327 		}
1328 		name.len = HEXDIR_LEN;
1329 		crp = nfsd4_find_reclaim_client(name, nn);
1330 		kfree(name.data);
1331 		if (crp)
1332 			goto found;
1333 
1334 	}
1335 #endif
1336 	return -ENOENT;
1337 found:
1338 	crp->cr_clp = clp;
1339 	return 0;
1340 }
1341 
1342 static int
1343 nfsd4_cld_check_v2(struct nfs4_client *clp)
1344 {
1345 	struct nfs4_client_reclaim *crp;
1346 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1347 	struct cld_net *cn = nn->cld_net;
1348 	int status;
1349 	struct crypto_shash *tfm = cn->cn_tfm;
1350 	struct xdr_netobj cksum;
1351 	char *principal = NULL;
1352 
1353 	/* did we already find that this client is stable? */
1354 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1355 		return 0;
1356 
1357 	/* look for it in the reclaim hashtable otherwise */
1358 	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1359 	if (crp)
1360 		goto found;
1361 
1362 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1363 	if (cn->cn_has_legacy) {
1364 		struct xdr_netobj name;
1365 		char dname[HEXDIR_LEN];
1366 
1367 		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1368 		if (status)
1369 			return -ENOENT;
1370 
1371 		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1372 		if (!name.data) {
1373 			dprintk("%s: failed to allocate memory for name.data\n",
1374 					__func__);
1375 			return -ENOENT;
1376 		}
1377 		name.len = HEXDIR_LEN;
1378 		crp = nfsd4_find_reclaim_client(name, nn);
1379 		kfree(name.data);
1380 		if (crp)
1381 			goto found;
1382 
1383 	}
1384 #endif
1385 	return -ENOENT;
1386 found:
1387 	if (crp->cr_princhash.len) {
1388 		if (clp->cl_cred.cr_raw_principal)
1389 			principal = clp->cl_cred.cr_raw_principal;
1390 		else if (clp->cl_cred.cr_principal)
1391 			principal = clp->cl_cred.cr_principal;
1392 		if (principal == NULL)
1393 			return -ENOENT;
1394 		cksum.len = crypto_shash_digestsize(tfm);
1395 		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1396 		if (cksum.data == NULL)
1397 			return -ENOENT;
1398 		status = crypto_shash_tfm_digest(tfm, principal,
1399 						 strlen(principal), cksum.data);
1400 		if (status) {
1401 			kfree(cksum.data);
1402 			return -ENOENT;
1403 		}
1404 		if (memcmp(crp->cr_princhash.data, cksum.data,
1405 				crp->cr_princhash.len)) {
1406 			kfree(cksum.data);
1407 			return -ENOENT;
1408 		}
1409 		kfree(cksum.data);
1410 	}
1411 	crp->cr_clp = clp;
1412 	return 0;
1413 }
1414 
1415 static int
1416 nfsd4_cld_grace_start(struct nfsd_net *nn)
1417 {
1418 	int ret;
1419 	struct cld_upcall *cup;
1420 	struct cld_net *cn = nn->cld_net;
1421 
1422 	cup = alloc_cld_upcall(nn);
1423 	if (!cup) {
1424 		ret = -ENOMEM;
1425 		goto out_err;
1426 	}
1427 
1428 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
1429 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1430 	if (!ret)
1431 		ret = cup->cu_u.cu_msg.cm_status;
1432 
1433 	free_cld_upcall(cup);
1434 out_err:
1435 	if (ret)
1436 		dprintk("%s: Unable to get clients from userspace: %d\n",
1437 			__func__, ret);
1438 	return ret;
1439 }
1440 
1441 /* For older nfsdcld's that need cm_gracetime */
1442 static void
1443 nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
1444 {
1445 	int ret;
1446 	struct cld_upcall *cup;
1447 	struct cld_net *cn = nn->cld_net;
1448 
1449 	cup = alloc_cld_upcall(nn);
1450 	if (!cup) {
1451 		ret = -ENOMEM;
1452 		goto out_err;
1453 	}
1454 
1455 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1456 	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
1457 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1458 	if (!ret)
1459 		ret = cup->cu_u.cu_msg.cm_status;
1460 
1461 	free_cld_upcall(cup);
1462 out_err:
1463 	if (ret)
1464 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1465 }
1466 
1467 /*
1468  * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
1469  * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
1470  */
1471 static void
1472 nfsd4_cld_grace_done(struct nfsd_net *nn)
1473 {
1474 	int ret;
1475 	struct cld_upcall *cup;
1476 	struct cld_net *cn = nn->cld_net;
1477 
1478 	cup = alloc_cld_upcall(nn);
1479 	if (!cup) {
1480 		ret = -ENOMEM;
1481 		goto out_err;
1482 	}
1483 
1484 	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1485 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1486 	if (!ret)
1487 		ret = cup->cu_u.cu_msg.cm_status;
1488 
1489 	free_cld_upcall(cup);
1490 out_err:
1491 	nfs4_release_reclaim(nn);
1492 	if (ret)
1493 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1494 }
1495 
1496 static int
1497 nfs4_cld_state_init(struct net *net)
1498 {
1499 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1500 	int i;
1501 
1502 	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
1503 						sizeof(struct list_head),
1504 						GFP_KERNEL);
1505 	if (!nn->reclaim_str_hashtbl)
1506 		return -ENOMEM;
1507 
1508 	for (i = 0; i < CLIENT_HASH_SIZE; i++)
1509 		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
1510 	nn->reclaim_str_hashtbl_size = 0;
1511 	nn->track_reclaim_completes = true;
1512 	atomic_set(&nn->nr_reclaim_complete, 0);
1513 
1514 	return 0;
1515 }
1516 
1517 static void
1518 nfs4_cld_state_shutdown(struct net *net)
1519 {
1520 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1521 
1522 	nn->track_reclaim_completes = false;
1523 	kfree(nn->reclaim_str_hashtbl);
1524 }
1525 
1526 static bool
1527 cld_running(struct nfsd_net *nn)
1528 {
1529 	struct cld_net *cn = nn->cld_net;
1530 	struct rpc_pipe *pipe = cn->cn_pipe;
1531 
1532 	return pipe->nreaders || pipe->nwriters;
1533 }
1534 
1535 static int
1536 nfsd4_cld_get_version(struct nfsd_net *nn)
1537 {
1538 	int ret = 0;
1539 	struct cld_upcall *cup;
1540 	struct cld_net *cn = nn->cld_net;
1541 	uint8_t version;
1542 
1543 	cup = alloc_cld_upcall(nn);
1544 	if (!cup) {
1545 		ret = -ENOMEM;
1546 		goto out_err;
1547 	}
1548 	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
1549 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1550 	if (!ret) {
1551 		ret = cup->cu_u.cu_msg.cm_status;
1552 		if (ret)
1553 			goto out_free;
1554 		version = cup->cu_u.cu_msg.cm_u.cm_version;
1555 		dprintk("%s: userspace returned version %u\n",
1556 				__func__, version);
1557 		if (version < 1)
1558 			version = 1;
1559 		else if (version > CLD_UPCALL_VERSION)
1560 			version = CLD_UPCALL_VERSION;
1561 
1562 		switch (version) {
1563 		case 1:
1564 			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1565 			break;
1566 		case 2:
1567 			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
1568 			break;
1569 		default:
1570 			break;
1571 		}
1572 	}
1573 out_free:
1574 	free_cld_upcall(cup);
1575 out_err:
1576 	if (ret)
1577 		dprintk("%s: Unable to get version from userspace: %d\n",
1578 			__func__, ret);
1579 	return ret;
1580 }
1581 
1582 static int
1583 nfsd4_cld_tracking_init(struct net *net)
1584 {
1585 	int status;
1586 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1587 	bool running;
1588 	int retries = 10;
1589 	struct crypto_shash *tfm;
1590 
1591 	status = nfs4_cld_state_init(net);
1592 	if (status)
1593 		return status;
1594 
1595 	status = __nfsd4_init_cld_pipe(net);
1596 	if (status)
1597 		goto err_shutdown;
1598 
1599 	/*
1600 	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
1601 	 * queue an upcall unless we know that nfsdcld is running (because we
1602 	 * want this to fail fast so that nfsd4_client_tracking_init() can try
1603 	 * the next client tracking method).  nfsdcld should already be running
1604 	 * before nfsd is started, so the wait here is for nfsdcld to open the
1605 	 * pipefs file we just created.
1606 	 */
1607 	while (!(running = cld_running(nn)) && retries--)
1608 		msleep(100);
1609 
1610 	if (!running) {
1611 		status = -ETIMEDOUT;
1612 		goto err_remove;
1613 	}
1614 	tfm = crypto_alloc_shash("sha256", 0, 0);
1615 	if (IS_ERR(tfm)) {
1616 		status = PTR_ERR(tfm);
1617 		goto err_remove;
1618 	}
1619 	nn->cld_net->cn_tfm = tfm;
1620 
1621 	status = nfsd4_cld_get_version(nn);
1622 	if (status == -EOPNOTSUPP)
1623 		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
1624 
1625 	status = nfsd4_cld_grace_start(nn);
1626 	if (status) {
1627 		if (status == -EOPNOTSUPP)
1628 			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
1629 		nfs4_release_reclaim(nn);
1630 		goto err_remove;
1631 	} else
1632 		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
1633 	return 0;
1634 
1635 err_remove:
1636 	nfsd4_remove_cld_pipe(net);
1637 err_shutdown:
1638 	nfs4_cld_state_shutdown(net);
1639 	return status;
1640 }
1641 
1642 static void
1643 nfsd4_cld_tracking_exit(struct net *net)
1644 {
1645 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1646 
1647 	nfs4_release_reclaim(nn);
1648 	nfsd4_remove_cld_pipe(net);
1649 	nfs4_cld_state_shutdown(net);
1650 }
1651 
1652 /* For older nfsdcld's */
1653 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
1654 	.init		= nfsd4_init_cld_pipe,
1655 	.exit		= nfsd4_remove_cld_pipe,
1656 	.create		= nfsd4_cld_create,
1657 	.remove		= nfsd4_cld_remove,
1658 	.check		= nfsd4_cld_check_v0,
1659 	.grace_done	= nfsd4_cld_grace_done_v0,
1660 	.version	= 1,
1661 	.msglen		= sizeof(struct cld_msg),
1662 };
1663 
1664 /* For newer nfsdcld's */
1665 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1666 	.init		= nfsd4_cld_tracking_init,
1667 	.exit		= nfsd4_cld_tracking_exit,
1668 	.create		= nfsd4_cld_create,
1669 	.remove		= nfsd4_cld_remove,
1670 	.check		= nfsd4_cld_check,
1671 	.grace_done	= nfsd4_cld_grace_done,
1672 	.version	= 1,
1673 	.msglen		= sizeof(struct cld_msg),
1674 };
1675 
1676 /* v2 create/check ops include the principal, if available */
1677 static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
1678 	.init		= nfsd4_cld_tracking_init,
1679 	.exit		= nfsd4_cld_tracking_exit,
1680 	.create		= nfsd4_cld_create_v2,
1681 	.remove		= nfsd4_cld_remove,
1682 	.check		= nfsd4_cld_check_v2,
1683 	.grace_done	= nfsd4_cld_grace_done,
1684 	.version	= 2,
1685 	.msglen		= sizeof(struct cld_msg_v2),
1686 };
1687 
1688 #ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1689 /* upcall via usermodehelper */
1690 static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1691 module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1692 			S_IRUGO|S_IWUSR);
1693 MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1694 
1695 static bool cltrack_legacy_disable;
1696 module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1697 MODULE_PARM_DESC(cltrack_legacy_disable,
1698 		"Disable legacy recoverydir conversion. Default: false");
1699 
1700 #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1701 #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1702 #define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1703 #define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1704 
1705 static char *
1706 nfsd4_cltrack_legacy_topdir(void)
1707 {
1708 	int copied;
1709 	size_t len;
1710 	char *result;
1711 
1712 	if (cltrack_legacy_disable)
1713 		return NULL;
1714 
1715 	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1716 		strlen(nfs4_recoverydir()) + 1;
1717 
1718 	result = kmalloc(len, GFP_KERNEL);
1719 	if (!result)
1720 		return result;
1721 
1722 	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1723 				nfs4_recoverydir());
1724 	if (copied >= len) {
1725 		/* just return nothing if output was truncated */
1726 		kfree(result);
1727 		return NULL;
1728 	}
1729 
1730 	return result;
1731 }
1732 
1733 static char *
1734 nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1735 {
1736 	int copied;
1737 	size_t len;
1738 	char *result;
1739 
1740 	if (cltrack_legacy_disable)
1741 		return NULL;
1742 
1743 	/* +1 is for '/' between "topdir" and "recdir" */
1744 	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1745 		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1746 
1747 	result = kmalloc(len, GFP_KERNEL);
1748 	if (!result)
1749 		return result;
1750 
1751 	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1752 				nfs4_recoverydir());
1753 	if (copied > (len - HEXDIR_LEN)) {
1754 		/* just return nothing if output will be truncated */
1755 		kfree(result);
1756 		return NULL;
1757 	}
1758 
1759 	copied = nfs4_make_rec_clidname(result + copied, name);
1760 	if (copied) {
1761 		kfree(result);
1762 		return NULL;
1763 	}
1764 
1765 	return result;
1766 }
1767 
1768 static char *
1769 nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1770 {
1771 	int copied;
1772 	size_t len;
1773 	char *result;
1774 
1775 	/* prefix + Y/N character + terminating NULL */
1776 	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1777 
1778 	result = kmalloc(len, GFP_KERNEL);
1779 	if (!result)
1780 		return result;
1781 
1782 	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1783 				clp->cl_minorversion ? 'Y' : 'N');
1784 	if (copied >= len) {
1785 		/* just return nothing if output was truncated */
1786 		kfree(result);
1787 		return NULL;
1788 	}
1789 
1790 	return result;
1791 }
1792 
1793 static char *
1794 nfsd4_cltrack_grace_start(time64_t grace_start)
1795 {
1796 	int copied;
1797 	size_t len;
1798 	char *result;
1799 
1800 	/* prefix + max width of int64_t string + terminating NULL */
1801 	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1802 
1803 	result = kmalloc(len, GFP_KERNEL);
1804 	if (!result)
1805 		return result;
1806 
1807 	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
1808 				grace_start);
1809 	if (copied >= len) {
1810 		/* just return nothing if output was truncated */
1811 		kfree(result);
1812 		return NULL;
1813 	}
1814 
1815 	return result;
1816 }
1817 
1818 static int
1819 nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1820 {
1821 	char *envp[3];
1822 	char *argv[4];
1823 	int ret;
1824 
1825 	if (unlikely(!cltrack_prog[0])) {
1826 		dprintk("%s: cltrack_prog is disabled\n", __func__);
1827 		return -EACCES;
1828 	}
1829 
1830 	dprintk("%s: cmd: %s\n", __func__, cmd);
1831 	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1832 	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1833 	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1834 
1835 	envp[0] = env0;
1836 	envp[1] = env1;
1837 	envp[2] = NULL;
1838 
1839 	argv[0] = (char *)cltrack_prog;
1840 	argv[1] = cmd;
1841 	argv[2] = arg;
1842 	argv[3] = NULL;
1843 
1844 	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1845 	/*
1846 	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1847 	 * error. The admin can re-enable it on the fly by using sysfs
1848 	 * once the problem has been fixed.
1849 	 */
1850 	if (ret == -ENOENT || ret == -EACCES) {
1851 		dprintk("NFSD: %s was not found or isn't executable (%d). "
1852 			"Setting cltrack_prog to blank string!",
1853 			cltrack_prog, ret);
1854 		cltrack_prog[0] = '\0';
1855 	}
1856 	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1857 
1858 	return ret;
1859 }
1860 
1861 static char *
1862 bin_to_hex_dup(const unsigned char *src, int srclen)
1863 {
1864 	char *buf;
1865 
1866 	/* +1 for terminating NULL */
1867 	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
1868 	if (!buf)
1869 		return buf;
1870 
1871 	bin2hex(buf, src, srclen);
1872 	return buf;
1873 }
1874 
1875 static int
1876 nfsd4_umh_cltrack_init(struct net *net)
1877 {
1878 	int ret;
1879 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1880 	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1881 
1882 	/* XXX: The usermode helper s not working in container yet. */
1883 	if (net != &init_net) {
1884 		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1885 		kfree(grace_start);
1886 		return -EINVAL;
1887 	}
1888 
1889 	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1890 	kfree(grace_start);
1891 	if (!ret)
1892 		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
1893 	return ret;
1894 }
1895 
1896 static void
1897 nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1898 {
1899 	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1900 			 TASK_UNINTERRUPTIBLE);
1901 }
1902 
1903 static void
1904 nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1905 {
1906 	clear_and_wake_up_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1907 }
1908 
1909 static void
1910 nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1911 {
1912 	char *hexid, *has_session, *grace_start;
1913 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1914 
1915 	/*
1916 	 * With v4.0 clients, there's little difference in outcome between a
1917 	 * create and check operation, and we can end up calling into this
1918 	 * function multiple times per client (once for each openowner). So,
1919 	 * for v4.0 clients skip upcalling once the client has been recorded
1920 	 * on stable storage.
1921 	 *
1922 	 * For v4.1+ clients, the outcome of the two operations is different,
1923 	 * so we must ensure that we upcall for the create operation. v4.1+
1924 	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1925 	 * up doing a single create upcall per client.
1926 	 */
1927 	if (clp->cl_minorversion == 0 &&
1928 	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1929 		return;
1930 
1931 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1932 	if (!hexid) {
1933 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1934 		return;
1935 	}
1936 
1937 	has_session = nfsd4_cltrack_client_has_session(clp);
1938 	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1939 
1940 	nfsd4_cltrack_upcall_lock(clp);
1941 	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1942 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1943 	nfsd4_cltrack_upcall_unlock(clp);
1944 
1945 	kfree(has_session);
1946 	kfree(grace_start);
1947 	kfree(hexid);
1948 }
1949 
1950 static void
1951 nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1952 {
1953 	char *hexid;
1954 
1955 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1956 		return;
1957 
1958 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1959 	if (!hexid) {
1960 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1961 		return;
1962 	}
1963 
1964 	nfsd4_cltrack_upcall_lock(clp);
1965 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1966 	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1967 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1968 	nfsd4_cltrack_upcall_unlock(clp);
1969 
1970 	kfree(hexid);
1971 }
1972 
1973 static int
1974 nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1975 {
1976 	int ret;
1977 	char *hexid, *has_session, *legacy;
1978 
1979 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1980 		return 0;
1981 
1982 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1983 	if (!hexid) {
1984 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1985 		return -ENOMEM;
1986 	}
1987 
1988 	has_session = nfsd4_cltrack_client_has_session(clp);
1989 	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1990 
1991 	nfsd4_cltrack_upcall_lock(clp);
1992 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1993 		ret = 0;
1994 	} else {
1995 		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1996 		if (ret == 0)
1997 			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1998 	}
1999 	nfsd4_cltrack_upcall_unlock(clp);
2000 	kfree(has_session);
2001 	kfree(legacy);
2002 	kfree(hexid);
2003 
2004 	return ret;
2005 }
2006 
2007 static void
2008 nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
2009 {
2010 	char *legacy;
2011 	char timestr[22]; /* FIXME: better way to determine max size? */
2012 
2013 	sprintf(timestr, "%lld", nn->boot_time);
2014 	legacy = nfsd4_cltrack_legacy_topdir();
2015 	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
2016 	kfree(legacy);
2017 }
2018 
2019 static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
2020 	.init		= nfsd4_umh_cltrack_init,
2021 	.exit		= NULL,
2022 	.create		= nfsd4_umh_cltrack_create,
2023 	.remove		= nfsd4_umh_cltrack_remove,
2024 	.check		= nfsd4_umh_cltrack_check,
2025 	.grace_done	= nfsd4_umh_cltrack_grace_done,
2026 	.version	= 1,
2027 	.msglen		= 0,
2028 };
2029 
2030 static inline int check_for_legacy_methods(int status, struct net *net)
2031 {
2032 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2033 	struct path path;
2034 
2035 	/*
2036 	 * Next, try the UMH upcall.
2037 	 */
2038 	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
2039 	status = nn->client_tracking_ops->init(net);
2040 	if (!status)
2041 		return status;
2042 
2043 	/*
2044 	 * Finally, See if the recoverydir exists and is a directory.
2045 	 * If it is, then use the legacy ops.
2046 	 */
2047 	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
2048 	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
2049 	if (!status) {
2050 		status = !d_is_dir(path.dentry);
2051 		path_put(&path);
2052 		if (status)
2053 			return -ENOTDIR;
2054 		status = nn->client_tracking_ops->init(net);
2055 	}
2056 	return status;
2057 }
2058 #else
2059 static inline int check_for_legacy_methods(int status, struct net *net)
2060 {
2061 	return status;
2062 }
2063 #endif /* CONFIG_LEGACY_NFSD_CLIENT_TRACKING */
2064 
2065 int
2066 nfsd4_client_tracking_init(struct net *net)
2067 {
2068 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2069 	int status;
2070 
2071 	/* just run the init if it the method is already decided */
2072 	if (nn->client_tracking_ops)
2073 		goto do_init;
2074 
2075 	/* First, try to use nfsdcld */
2076 	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
2077 	status = nn->client_tracking_ops->init(net);
2078 	if (!status)
2079 		return status;
2080 	if (status != -ETIMEDOUT) {
2081 		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
2082 		status = nn->client_tracking_ops->init(net);
2083 		if (!status)
2084 			return status;
2085 	}
2086 
2087 	status = check_for_legacy_methods(status, net);
2088 	if (status)
2089 		goto out;
2090 do_init:
2091 	status = nn->client_tracking_ops->init(net);
2092 out:
2093 	if (status) {
2094 		pr_warn("NFSD: Unable to initialize client recovery tracking! (%d)\n", status);
2095 		pr_warn("NFSD: Is nfsdcld running? If not, enable CONFIG_NFSD_LEGACY_CLIENT_TRACKING.\n");
2096 		nn->client_tracking_ops = NULL;
2097 	}
2098 	return status;
2099 }
2100 
2101 void
2102 nfsd4_client_tracking_exit(struct net *net)
2103 {
2104 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2105 
2106 	if (nn->client_tracking_ops) {
2107 		if (nn->client_tracking_ops->exit)
2108 			nn->client_tracking_ops->exit(net);
2109 		nn->client_tracking_ops = NULL;
2110 	}
2111 }
2112 
2113 void
2114 nfsd4_client_record_create(struct nfs4_client *clp)
2115 {
2116 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2117 
2118 	if (nn->client_tracking_ops)
2119 		nn->client_tracking_ops->create(clp);
2120 }
2121 
2122 void
2123 nfsd4_client_record_remove(struct nfs4_client *clp)
2124 {
2125 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2126 
2127 	if (nn->client_tracking_ops)
2128 		nn->client_tracking_ops->remove(clp);
2129 }
2130 
2131 int
2132 nfsd4_client_record_check(struct nfs4_client *clp)
2133 {
2134 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2135 
2136 	if (nn->client_tracking_ops)
2137 		return nn->client_tracking_ops->check(clp);
2138 
2139 	return -EOPNOTSUPP;
2140 }
2141 
2142 void
2143 nfsd4_record_grace_done(struct nfsd_net *nn)
2144 {
2145 	if (nn->client_tracking_ops)
2146 		nn->client_tracking_ops->grace_done(nn);
2147 }
2148 
2149 static int
2150 rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
2151 {
2152 	struct super_block *sb = ptr;
2153 	struct net *net = sb->s_fs_info;
2154 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2155 	struct cld_net *cn = nn->cld_net;
2156 	struct dentry *dentry;
2157 	int ret = 0;
2158 
2159 	if (!try_module_get(THIS_MODULE))
2160 		return 0;
2161 
2162 	if (!cn) {
2163 		module_put(THIS_MODULE);
2164 		return 0;
2165 	}
2166 
2167 	switch (event) {
2168 	case RPC_PIPEFS_MOUNT:
2169 		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
2170 		if (IS_ERR(dentry)) {
2171 			ret = PTR_ERR(dentry);
2172 			break;
2173 		}
2174 		cn->cn_pipe->dentry = dentry;
2175 		break;
2176 	case RPC_PIPEFS_UMOUNT:
2177 		if (cn->cn_pipe->dentry)
2178 			nfsd4_cld_unregister_sb(cn->cn_pipe);
2179 		break;
2180 	default:
2181 		ret = -ENOTSUPP;
2182 		break;
2183 	}
2184 	module_put(THIS_MODULE);
2185 	return ret;
2186 }
2187 
2188 static struct notifier_block nfsd4_cld_block = {
2189 	.notifier_call = rpc_pipefs_event,
2190 };
2191 
2192 int
2193 register_cld_notifier(void)
2194 {
2195 	WARN_ON(!nfsd_net_id);
2196 	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
2197 }
2198 
2199 void
2200 unregister_cld_notifier(void)
2201 {
2202 	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
2203 }
2204