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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 <linux/file.h>
36 #include <linux/slab.h>
37 #include <linux/namei.h>
38 #include <linux/crypto.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 *, time_t);
62 };
63 
64 /* Globals */
65 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
66 
67 static int
nfs4_save_creds(const struct cred ** original_creds)68 nfs4_save_creds(const struct cred **original_creds)
69 {
70 	struct cred *new;
71 
72 	new = prepare_creds();
73 	if (!new)
74 		return -ENOMEM;
75 
76 	new->fsuid = GLOBAL_ROOT_UID;
77 	new->fsgid = GLOBAL_ROOT_GID;
78 	*original_creds = override_creds(new);
79 	put_cred(new);
80 	return 0;
81 }
82 
83 static void
nfs4_reset_creds(const struct cred * original)84 nfs4_reset_creds(const struct cred *original)
85 {
86 	revert_creds(original);
87 }
88 
89 static void
md5_to_hex(char * out,char * md5)90 md5_to_hex(char *out, char *md5)
91 {
92 	int i;
93 
94 	for (i=0; i<16; i++) {
95 		unsigned char c = md5[i];
96 
97 		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
98 		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
99 	}
100 	*out = '\0';
101 }
102 
103 static int
nfs4_make_rec_clidname(char * dname,const struct xdr_netobj * clname)104 nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
105 {
106 	struct xdr_netobj cksum;
107 	struct hash_desc desc;
108 	struct scatterlist sg;
109 	int status;
110 
111 	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
112 			clname->len, clname->data);
113 	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
114 	desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
115 	if (IS_ERR(desc.tfm)) {
116 		status = PTR_ERR(desc.tfm);
117 		goto out_no_tfm;
118 	}
119 
120 	cksum.len = crypto_hash_digestsize(desc.tfm);
121 	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
122 	if (cksum.data == NULL) {
123 		status = -ENOMEM;
124  		goto out;
125 	}
126 
127 	sg_init_one(&sg, clname->data, clname->len);
128 
129 	status = crypto_hash_digest(&desc, &sg, sg.length, cksum.data);
130 	if (status)
131 		goto out;
132 
133 	md5_to_hex(dname, cksum.data);
134 
135 	status = 0;
136 out:
137 	kfree(cksum.data);
138 	crypto_free_hash(desc.tfm);
139 out_no_tfm:
140 	return status;
141 }
142 
143 /*
144  * If we had an error generating the recdir name for the legacy tracker
145  * then warn the admin. If the error doesn't appear to be transient,
146  * then disable recovery tracking.
147  */
148 static void
legacy_recdir_name_error(struct nfs4_client * clp,int error)149 legacy_recdir_name_error(struct nfs4_client *clp, int error)
150 {
151 	printk(KERN_ERR "NFSD: unable to generate recoverydir "
152 			"name (%d).\n", error);
153 
154 	/*
155 	 * if the algorithm just doesn't exist, then disable the recovery
156 	 * tracker altogether. The crypto libs will generally return this if
157 	 * FIPS is enabled as well.
158 	 */
159 	if (error == -ENOENT) {
160 		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
161 			"Reboot recovery will not function correctly!\n");
162 		nfsd4_client_tracking_exit(clp->net);
163 	}
164 }
165 
166 static void
nfsd4_create_clid_dir(struct nfs4_client * clp)167 nfsd4_create_clid_dir(struct nfs4_client *clp)
168 {
169 	const struct cred *original_cred;
170 	char dname[HEXDIR_LEN];
171 	struct dentry *dir, *dentry;
172 	struct nfs4_client_reclaim *crp;
173 	int status;
174 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
175 
176 	dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
177 
178 	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
179 		return;
180 	if (!nn->rec_file)
181 		return;
182 
183 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
184 	if (status)
185 		return legacy_recdir_name_error(clp, status);
186 
187 	status = nfs4_save_creds(&original_cred);
188 	if (status < 0)
189 		return;
190 
191 	status = mnt_want_write_file(nn->rec_file);
192 	if (status)
193 		return;
194 
195 	dir = nn->rec_file->f_path.dentry;
196 	/* lock the parent */
197 	mutex_lock(&dir->d_inode->i_mutex);
198 
199 	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
200 	if (IS_ERR(dentry)) {
201 		status = PTR_ERR(dentry);
202 		goto out_unlock;
203 	}
204 	if (dentry->d_inode)
205 		/*
206 		 * In the 4.1 case, where we're called from
207 		 * reclaim_complete(), records from the previous reboot
208 		 * may still be left, so this is OK.
209 		 *
210 		 * In the 4.0 case, we should never get here; but we may
211 		 * as well be forgiving and just succeed silently.
212 		 */
213 		goto out_put;
214 	status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
215 out_put:
216 	dput(dentry);
217 out_unlock:
218 	mutex_unlock(&dir->d_inode->i_mutex);
219 	if (status == 0) {
220 		if (nn->in_grace) {
221 			crp = nfs4_client_to_reclaim(dname, nn);
222 			if (crp)
223 				crp->cr_clp = clp;
224 		}
225 		vfs_fsync(nn->rec_file, 0);
226 	} else {
227 		printk(KERN_ERR "NFSD: failed to write recovery record"
228 				" (err %d); please check that %s exists"
229 				" and is writeable", status,
230 				user_recovery_dirname);
231 	}
232 	mnt_drop_write_file(nn->rec_file);
233 	nfs4_reset_creds(original_cred);
234 }
235 
236 typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
237 
238 struct name_list {
239 	char name[HEXDIR_LEN];
240 	struct list_head list;
241 };
242 
243 struct nfs4_dir_ctx {
244 	struct dir_context ctx;
245 	struct list_head names;
246 };
247 
248 static int
nfsd4_build_namelist(void * arg,const char * name,int namlen,loff_t offset,u64 ino,unsigned int d_type)249 nfsd4_build_namelist(void *arg, const char *name, int namlen,
250 		loff_t offset, u64 ino, unsigned int d_type)
251 {
252 	struct nfs4_dir_ctx *ctx = arg;
253 	struct name_list *entry;
254 
255 	if (namlen != HEXDIR_LEN - 1)
256 		return 0;
257 	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
258 	if (entry == NULL)
259 		return -ENOMEM;
260 	memcpy(entry->name, name, HEXDIR_LEN - 1);
261 	entry->name[HEXDIR_LEN - 1] = '\0';
262 	list_add(&entry->list, &ctx->names);
263 	return 0;
264 }
265 
266 static int
nfsd4_list_rec_dir(recdir_func * f,struct nfsd_net * nn)267 nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
268 {
269 	const struct cred *original_cred;
270 	struct dentry *dir = nn->rec_file->f_path.dentry;
271 	struct nfs4_dir_ctx ctx = {
272 		.ctx.actor = nfsd4_build_namelist,
273 		.names = LIST_HEAD_INIT(ctx.names)
274 	};
275 	int status;
276 
277 	status = nfs4_save_creds(&original_cred);
278 	if (status < 0)
279 		return status;
280 
281 	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
282 	if (status < 0) {
283 		nfs4_reset_creds(original_cred);
284 		return status;
285 	}
286 
287 	status = iterate_dir(nn->rec_file, &ctx.ctx);
288 	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
289 	while (!list_empty(&ctx.names)) {
290 		struct name_list *entry;
291 		entry = list_entry(ctx.names.next, struct name_list, list);
292 		if (!status) {
293 			struct dentry *dentry;
294 			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
295 			if (IS_ERR(dentry)) {
296 				status = PTR_ERR(dentry);
297 				break;
298 			}
299 			status = f(dir, dentry, nn);
300 			dput(dentry);
301 		}
302 		list_del(&entry->list);
303 		kfree(entry);
304 	}
305 	mutex_unlock(&dir->d_inode->i_mutex);
306 	nfs4_reset_creds(original_cred);
307 	return status;
308 }
309 
310 static int
nfsd4_unlink_clid_dir(char * name,int namlen,struct nfsd_net * nn)311 nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
312 {
313 	struct dentry *dir, *dentry;
314 	int status;
315 
316 	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
317 
318 	dir = nn->rec_file->f_path.dentry;
319 	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
320 	dentry = lookup_one_len(name, dir, namlen);
321 	if (IS_ERR(dentry)) {
322 		status = PTR_ERR(dentry);
323 		goto out_unlock;
324 	}
325 	status = -ENOENT;
326 	if (!dentry->d_inode)
327 		goto out;
328 	status = vfs_rmdir(dir->d_inode, dentry);
329 out:
330 	dput(dentry);
331 out_unlock:
332 	mutex_unlock(&dir->d_inode->i_mutex);
333 	return status;
334 }
335 
336 static void
nfsd4_remove_clid_dir(struct nfs4_client * clp)337 nfsd4_remove_clid_dir(struct nfs4_client *clp)
338 {
339 	const struct cred *original_cred;
340 	struct nfs4_client_reclaim *crp;
341 	char dname[HEXDIR_LEN];
342 	int status;
343 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
344 
345 	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
346 		return;
347 
348 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
349 	if (status)
350 		return legacy_recdir_name_error(clp, status);
351 
352 	status = mnt_want_write_file(nn->rec_file);
353 	if (status)
354 		goto out;
355 	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
356 
357 	status = nfs4_save_creds(&original_cred);
358 	if (status < 0)
359 		goto out_drop_write;
360 
361 	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
362 	nfs4_reset_creds(original_cred);
363 	if (status == 0) {
364 		vfs_fsync(nn->rec_file, 0);
365 		if (nn->in_grace) {
366 			/* remove reclaim record */
367 			crp = nfsd4_find_reclaim_client(dname, nn);
368 			if (crp)
369 				nfs4_remove_reclaim_record(crp, nn);
370 		}
371 	}
372 out_drop_write:
373 	mnt_drop_write_file(nn->rec_file);
374 out:
375 	if (status)
376 		printk("NFSD: Failed to remove expired client state directory"
377 				" %.*s\n", HEXDIR_LEN, dname);
378 }
379 
380 static int
purge_old(struct dentry * parent,struct dentry * child,struct nfsd_net * nn)381 purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
382 {
383 	int status;
384 
385 	if (nfs4_has_reclaimed_state(child->d_name.name, nn))
386 		return 0;
387 
388 	status = vfs_rmdir(parent->d_inode, child);
389 	if (status)
390 		printk("failed to remove client recovery directory %s\n",
391 				child->d_name.name);
392 	/* Keep trying, success or failure: */
393 	return 0;
394 }
395 
396 static void
nfsd4_recdir_purge_old(struct nfsd_net * nn,time_t boot_time)397 nfsd4_recdir_purge_old(struct nfsd_net *nn, time_t boot_time)
398 {
399 	int status;
400 
401 	nn->in_grace = false;
402 	if (!nn->rec_file)
403 		return;
404 	status = mnt_want_write_file(nn->rec_file);
405 	if (status)
406 		goto out;
407 	status = nfsd4_list_rec_dir(purge_old, nn);
408 	if (status == 0)
409 		vfs_fsync(nn->rec_file, 0);
410 	mnt_drop_write_file(nn->rec_file);
411 out:
412 	nfs4_release_reclaim(nn);
413 	if (status)
414 		printk("nfsd4: failed to purge old clients from recovery"
415 			" directory %s\n", nn->rec_file->f_path.dentry->d_name.name);
416 }
417 
418 static int
load_recdir(struct dentry * parent,struct dentry * child,struct nfsd_net * nn)419 load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
420 {
421 	if (child->d_name.len != HEXDIR_LEN - 1) {
422 		printk("nfsd4: illegal name %s in recovery directory\n",
423 				child->d_name.name);
424 		/* Keep trying; maybe the others are OK: */
425 		return 0;
426 	}
427 	nfs4_client_to_reclaim(child->d_name.name, nn);
428 	return 0;
429 }
430 
431 static int
nfsd4_recdir_load(struct net * net)432 nfsd4_recdir_load(struct net *net) {
433 	int status;
434 	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
435 
436 	if (!nn->rec_file)
437 		return 0;
438 
439 	status = nfsd4_list_rec_dir(load_recdir, nn);
440 	if (status)
441 		printk("nfsd4: failed loading clients from recovery"
442 			" directory %s\n", nn->rec_file->f_path.dentry->d_name.name);
443 	return status;
444 }
445 
446 /*
447  * Hold reference to the recovery directory.
448  */
449 
450 static int
nfsd4_init_recdir(struct net * net)451 nfsd4_init_recdir(struct net *net)
452 {
453 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
454 	const struct cred *original_cred;
455 	int status;
456 
457 	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
458 			user_recovery_dirname);
459 
460 	BUG_ON(nn->rec_file);
461 
462 	status = nfs4_save_creds(&original_cred);
463 	if (status < 0) {
464 		printk("NFSD: Unable to change credentials to find recovery"
465 		       " directory: error %d\n",
466 		       status);
467 		return status;
468 	}
469 
470 	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
471 	if (IS_ERR(nn->rec_file)) {
472 		printk("NFSD: unable to find recovery directory %s\n",
473 				user_recovery_dirname);
474 		status = PTR_ERR(nn->rec_file);
475 		nn->rec_file = NULL;
476 	}
477 
478 	nfs4_reset_creds(original_cred);
479 	if (!status)
480 		nn->in_grace = true;
481 	return status;
482 }
483 
484 
485 static int
nfs4_legacy_state_init(struct net * net)486 nfs4_legacy_state_init(struct net *net)
487 {
488 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
489 	int i;
490 
491 	nn->reclaim_str_hashtbl = kmalloc(sizeof(struct list_head) *
492 					  CLIENT_HASH_SIZE, GFP_KERNEL);
493 	if (!nn->reclaim_str_hashtbl)
494 		return -ENOMEM;
495 
496 	for (i = 0; i < CLIENT_HASH_SIZE; i++)
497 		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
498 	nn->reclaim_str_hashtbl_size = 0;
499 
500 	return 0;
501 }
502 
503 static void
nfs4_legacy_state_shutdown(struct net * net)504 nfs4_legacy_state_shutdown(struct net *net)
505 {
506 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
507 
508 	kfree(nn->reclaim_str_hashtbl);
509 }
510 
511 static int
nfsd4_load_reboot_recovery_data(struct net * net)512 nfsd4_load_reboot_recovery_data(struct net *net)
513 {
514 	int status;
515 
516 	status = nfsd4_init_recdir(net);
517 	if (!status)
518 		status = nfsd4_recdir_load(net);
519 	if (status)
520 		printk(KERN_ERR "NFSD: Failure reading reboot recovery data\n");
521 	return status;
522 }
523 
524 static int
nfsd4_legacy_tracking_init(struct net * net)525 nfsd4_legacy_tracking_init(struct net *net)
526 {
527 	int status;
528 
529 	/* XXX: The legacy code won't work in a container */
530 	if (net != &init_net) {
531 		WARN(1, KERN_ERR "NFSD: attempt to initialize legacy client "
532 			"tracking in a container!\n");
533 		return -EINVAL;
534 	}
535 
536 	status = nfs4_legacy_state_init(net);
537 	if (status)
538 		return status;
539 
540 	status = nfsd4_load_reboot_recovery_data(net);
541 	if (status)
542 		goto err;
543 	return 0;
544 
545 err:
546 	nfs4_legacy_state_shutdown(net);
547 	return status;
548 }
549 
550 static void
nfsd4_shutdown_recdir(struct nfsd_net * nn)551 nfsd4_shutdown_recdir(struct nfsd_net *nn)
552 {
553 	if (!nn->rec_file)
554 		return;
555 	fput(nn->rec_file);
556 	nn->rec_file = NULL;
557 }
558 
559 static void
nfsd4_legacy_tracking_exit(struct net * net)560 nfsd4_legacy_tracking_exit(struct net *net)
561 {
562 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
563 
564 	nfs4_release_reclaim(nn);
565 	nfsd4_shutdown_recdir(nn);
566 	nfs4_legacy_state_shutdown(net);
567 }
568 
569 /*
570  * Change the NFSv4 recovery directory to recdir.
571  */
572 int
nfs4_reset_recoverydir(char * recdir)573 nfs4_reset_recoverydir(char *recdir)
574 {
575 	int status;
576 	struct path path;
577 
578 	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
579 	if (status)
580 		return status;
581 	status = -ENOTDIR;
582 	if (S_ISDIR(path.dentry->d_inode->i_mode)) {
583 		strcpy(user_recovery_dirname, recdir);
584 		status = 0;
585 	}
586 	path_put(&path);
587 	return status;
588 }
589 
590 char *
nfs4_recoverydir(void)591 nfs4_recoverydir(void)
592 {
593 	return user_recovery_dirname;
594 }
595 
596 static int
nfsd4_check_legacy_client(struct nfs4_client * clp)597 nfsd4_check_legacy_client(struct nfs4_client *clp)
598 {
599 	int status;
600 	char dname[HEXDIR_LEN];
601 	struct nfs4_client_reclaim *crp;
602 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
603 
604 	/* did we already find that this client is stable? */
605 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
606 		return 0;
607 
608 	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
609 	if (status) {
610 		legacy_recdir_name_error(clp, status);
611 		return status;
612 	}
613 
614 	/* look for it in the reclaim hashtable otherwise */
615 	crp = nfsd4_find_reclaim_client(dname, nn);
616 	if (crp) {
617 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
618 		crp->cr_clp = clp;
619 		return 0;
620 	}
621 
622 	return -ENOENT;
623 }
624 
625 static struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
626 	.init		= nfsd4_legacy_tracking_init,
627 	.exit		= nfsd4_legacy_tracking_exit,
628 	.create		= nfsd4_create_clid_dir,
629 	.remove		= nfsd4_remove_clid_dir,
630 	.check		= nfsd4_check_legacy_client,
631 	.grace_done	= nfsd4_recdir_purge_old,
632 };
633 
634 /* Globals */
635 #define NFSD_PIPE_DIR		"nfsd"
636 #define NFSD_CLD_PIPE		"cld"
637 
638 /* per-net-ns structure for holding cld upcall info */
639 struct cld_net {
640 	struct rpc_pipe		*cn_pipe;
641 	spinlock_t		 cn_lock;
642 	struct list_head	 cn_list;
643 	unsigned int		 cn_xid;
644 };
645 
646 struct cld_upcall {
647 	struct list_head	 cu_list;
648 	struct cld_net		*cu_net;
649 	struct task_struct	*cu_task;
650 	struct cld_msg		 cu_msg;
651 };
652 
653 static int
__cld_pipe_upcall(struct rpc_pipe * pipe,struct cld_msg * cmsg)654 __cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
655 {
656 	int ret;
657 	struct rpc_pipe_msg msg;
658 
659 	memset(&msg, 0, sizeof(msg));
660 	msg.data = cmsg;
661 	msg.len = sizeof(*cmsg);
662 
663 	/*
664 	 * Set task state before we queue the upcall. That prevents
665 	 * wake_up_process in the downcall from racing with schedule.
666 	 */
667 	set_current_state(TASK_UNINTERRUPTIBLE);
668 	ret = rpc_queue_upcall(pipe, &msg);
669 	if (ret < 0) {
670 		set_current_state(TASK_RUNNING);
671 		goto out;
672 	}
673 
674 	schedule();
675 	set_current_state(TASK_RUNNING);
676 
677 	if (msg.errno < 0)
678 		ret = msg.errno;
679 out:
680 	return ret;
681 }
682 
683 static int
cld_pipe_upcall(struct rpc_pipe * pipe,struct cld_msg * cmsg)684 cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
685 {
686 	int ret;
687 
688 	/*
689 	 * -EAGAIN occurs when pipe is closed and reopened while there are
690 	 *  upcalls queued.
691 	 */
692 	do {
693 		ret = __cld_pipe_upcall(pipe, cmsg);
694 	} while (ret == -EAGAIN);
695 
696 	return ret;
697 }
698 
699 static ssize_t
cld_pipe_downcall(struct file * filp,const char __user * src,size_t mlen)700 cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
701 {
702 	struct cld_upcall *tmp, *cup;
703 	struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
704 	uint32_t xid;
705 	struct nfsd_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,
706 						nfsd_net_id);
707 	struct cld_net *cn = nn->cld_net;
708 
709 	if (mlen != sizeof(*cmsg)) {
710 		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
711 			sizeof(*cmsg));
712 		return -EINVAL;
713 	}
714 
715 	/* copy just the xid so we can try to find that */
716 	if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
717 		dprintk("%s: error when copying xid from userspace", __func__);
718 		return -EFAULT;
719 	}
720 
721 	/* walk the list and find corresponding xid */
722 	cup = NULL;
723 	spin_lock(&cn->cn_lock);
724 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
725 		if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
726 			cup = tmp;
727 			list_del_init(&cup->cu_list);
728 			break;
729 		}
730 	}
731 	spin_unlock(&cn->cn_lock);
732 
733 	/* couldn't find upcall? */
734 	if (!cup) {
735 		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
736 		return -EINVAL;
737 	}
738 
739 	if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
740 		return -EFAULT;
741 
742 	wake_up_process(cup->cu_task);
743 	return mlen;
744 }
745 
746 static void
cld_pipe_destroy_msg(struct rpc_pipe_msg * msg)747 cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
748 {
749 	struct cld_msg *cmsg = msg->data;
750 	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
751 						 cu_msg);
752 
753 	/* errno >= 0 means we got a downcall */
754 	if (msg->errno >= 0)
755 		return;
756 
757 	wake_up_process(cup->cu_task);
758 }
759 
760 static const struct rpc_pipe_ops cld_upcall_ops = {
761 	.upcall		= rpc_pipe_generic_upcall,
762 	.downcall	= cld_pipe_downcall,
763 	.destroy_msg	= cld_pipe_destroy_msg,
764 };
765 
766 static struct dentry *
nfsd4_cld_register_sb(struct super_block * sb,struct rpc_pipe * pipe)767 nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
768 {
769 	struct dentry *dir, *dentry;
770 
771 	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
772 	if (dir == NULL)
773 		return ERR_PTR(-ENOENT);
774 	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
775 	dput(dir);
776 	return dentry;
777 }
778 
779 static void
nfsd4_cld_unregister_sb(struct rpc_pipe * pipe)780 nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
781 {
782 	if (pipe->dentry)
783 		rpc_unlink(pipe->dentry);
784 }
785 
786 static struct dentry *
nfsd4_cld_register_net(struct net * net,struct rpc_pipe * pipe)787 nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
788 {
789 	struct super_block *sb;
790 	struct dentry *dentry;
791 
792 	sb = rpc_get_sb_net(net);
793 	if (!sb)
794 		return NULL;
795 	dentry = nfsd4_cld_register_sb(sb, pipe);
796 	rpc_put_sb_net(net);
797 	return dentry;
798 }
799 
800 static void
nfsd4_cld_unregister_net(struct net * net,struct rpc_pipe * pipe)801 nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
802 {
803 	struct super_block *sb;
804 
805 	sb = rpc_get_sb_net(net);
806 	if (sb) {
807 		nfsd4_cld_unregister_sb(pipe);
808 		rpc_put_sb_net(net);
809 	}
810 }
811 
812 /* Initialize rpc_pipefs pipe for communication with client tracking daemon */
813 static int
nfsd4_init_cld_pipe(struct net * net)814 nfsd4_init_cld_pipe(struct net *net)
815 {
816 	int ret;
817 	struct dentry *dentry;
818 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
819 	struct cld_net *cn;
820 
821 	if (nn->cld_net)
822 		return 0;
823 
824 	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
825 	if (!cn) {
826 		ret = -ENOMEM;
827 		goto err;
828 	}
829 
830 	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
831 	if (IS_ERR(cn->cn_pipe)) {
832 		ret = PTR_ERR(cn->cn_pipe);
833 		goto err;
834 	}
835 	spin_lock_init(&cn->cn_lock);
836 	INIT_LIST_HEAD(&cn->cn_list);
837 
838 	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
839 	if (IS_ERR(dentry)) {
840 		ret = PTR_ERR(dentry);
841 		goto err_destroy_data;
842 	}
843 
844 	cn->cn_pipe->dentry = dentry;
845 	nn->cld_net = cn;
846 	return 0;
847 
848 err_destroy_data:
849 	rpc_destroy_pipe_data(cn->cn_pipe);
850 err:
851 	kfree(cn);
852 	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
853 			ret);
854 	return ret;
855 }
856 
857 static void
nfsd4_remove_cld_pipe(struct net * net)858 nfsd4_remove_cld_pipe(struct net *net)
859 {
860 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
861 	struct cld_net *cn = nn->cld_net;
862 
863 	nfsd4_cld_unregister_net(net, cn->cn_pipe);
864 	rpc_destroy_pipe_data(cn->cn_pipe);
865 	kfree(nn->cld_net);
866 	nn->cld_net = NULL;
867 }
868 
869 static struct cld_upcall *
alloc_cld_upcall(struct cld_net * cn)870 alloc_cld_upcall(struct cld_net *cn)
871 {
872 	struct cld_upcall *new, *tmp;
873 
874 	new = kzalloc(sizeof(*new), GFP_KERNEL);
875 	if (!new)
876 		return new;
877 
878 	/* FIXME: hard cap on number in flight? */
879 restart_search:
880 	spin_lock(&cn->cn_lock);
881 	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
882 		if (tmp->cu_msg.cm_xid == cn->cn_xid) {
883 			cn->cn_xid++;
884 			spin_unlock(&cn->cn_lock);
885 			goto restart_search;
886 		}
887 	}
888 	new->cu_task = current;
889 	new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
890 	put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
891 	new->cu_net = cn;
892 	list_add(&new->cu_list, &cn->cn_list);
893 	spin_unlock(&cn->cn_lock);
894 
895 	dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
896 
897 	return new;
898 }
899 
900 static void
free_cld_upcall(struct cld_upcall * victim)901 free_cld_upcall(struct cld_upcall *victim)
902 {
903 	struct cld_net *cn = victim->cu_net;
904 
905 	spin_lock(&cn->cn_lock);
906 	list_del(&victim->cu_list);
907 	spin_unlock(&cn->cn_lock);
908 	kfree(victim);
909 }
910 
911 /* Ask daemon to create a new record */
912 static void
nfsd4_cld_create(struct nfs4_client * clp)913 nfsd4_cld_create(struct nfs4_client *clp)
914 {
915 	int ret;
916 	struct cld_upcall *cup;
917 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
918 	struct cld_net *cn = nn->cld_net;
919 
920 	/* Don't upcall if it's already stored */
921 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
922 		return;
923 
924 	cup = alloc_cld_upcall(cn);
925 	if (!cup) {
926 		ret = -ENOMEM;
927 		goto out_err;
928 	}
929 
930 	cup->cu_msg.cm_cmd = Cld_Create;
931 	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
932 	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
933 			clp->cl_name.len);
934 
935 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
936 	if (!ret) {
937 		ret = cup->cu_msg.cm_status;
938 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
939 	}
940 
941 	free_cld_upcall(cup);
942 out_err:
943 	if (ret)
944 		printk(KERN_ERR "NFSD: Unable to create client "
945 				"record on stable storage: %d\n", ret);
946 }
947 
948 /* Ask daemon to create a new record */
949 static void
nfsd4_cld_remove(struct nfs4_client * clp)950 nfsd4_cld_remove(struct nfs4_client *clp)
951 {
952 	int ret;
953 	struct cld_upcall *cup;
954 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
955 	struct cld_net *cn = nn->cld_net;
956 
957 	/* Don't upcall if it's already removed */
958 	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
959 		return;
960 
961 	cup = alloc_cld_upcall(cn);
962 	if (!cup) {
963 		ret = -ENOMEM;
964 		goto out_err;
965 	}
966 
967 	cup->cu_msg.cm_cmd = Cld_Remove;
968 	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
969 	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
970 			clp->cl_name.len);
971 
972 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
973 	if (!ret) {
974 		ret = cup->cu_msg.cm_status;
975 		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
976 	}
977 
978 	free_cld_upcall(cup);
979 out_err:
980 	if (ret)
981 		printk(KERN_ERR "NFSD: Unable to remove client "
982 				"record from stable storage: %d\n", ret);
983 }
984 
985 /* Check for presence of a record, and update its timestamp */
986 static int
nfsd4_cld_check(struct nfs4_client * clp)987 nfsd4_cld_check(struct nfs4_client *clp)
988 {
989 	int ret;
990 	struct cld_upcall *cup;
991 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
992 	struct cld_net *cn = nn->cld_net;
993 
994 	/* Don't upcall if one was already stored during this grace pd */
995 	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
996 		return 0;
997 
998 	cup = alloc_cld_upcall(cn);
999 	if (!cup) {
1000 		printk(KERN_ERR "NFSD: Unable to check client record on "
1001 				"stable storage: %d\n", -ENOMEM);
1002 		return -ENOMEM;
1003 	}
1004 
1005 	cup->cu_msg.cm_cmd = Cld_Check;
1006 	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1007 	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1008 			clp->cl_name.len);
1009 
1010 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1011 	if (!ret) {
1012 		ret = cup->cu_msg.cm_status;
1013 		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1014 	}
1015 
1016 	free_cld_upcall(cup);
1017 	return ret;
1018 }
1019 
1020 static void
nfsd4_cld_grace_done(struct nfsd_net * nn,time_t boot_time)1021 nfsd4_cld_grace_done(struct nfsd_net *nn, time_t boot_time)
1022 {
1023 	int ret;
1024 	struct cld_upcall *cup;
1025 	struct cld_net *cn = nn->cld_net;
1026 
1027 	cup = alloc_cld_upcall(cn);
1028 	if (!cup) {
1029 		ret = -ENOMEM;
1030 		goto out_err;
1031 	}
1032 
1033 	cup->cu_msg.cm_cmd = Cld_GraceDone;
1034 	cup->cu_msg.cm_u.cm_gracetime = (int64_t)boot_time;
1035 	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1036 	if (!ret)
1037 		ret = cup->cu_msg.cm_status;
1038 
1039 	free_cld_upcall(cup);
1040 out_err:
1041 	if (ret)
1042 		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1043 }
1044 
1045 static struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1046 	.init		= nfsd4_init_cld_pipe,
1047 	.exit		= nfsd4_remove_cld_pipe,
1048 	.create		= nfsd4_cld_create,
1049 	.remove		= nfsd4_cld_remove,
1050 	.check		= nfsd4_cld_check,
1051 	.grace_done	= nfsd4_cld_grace_done,
1052 };
1053 
1054 /* upcall via usermodehelper */
1055 static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1056 module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1057 			S_IRUGO|S_IWUSR);
1058 MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1059 
1060 static bool cltrack_legacy_disable;
1061 module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1062 MODULE_PARM_DESC(cltrack_legacy_disable,
1063 		"Disable legacy recoverydir conversion. Default: false");
1064 
1065 #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1066 #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1067 
1068 static char *
nfsd4_cltrack_legacy_topdir(void)1069 nfsd4_cltrack_legacy_topdir(void)
1070 {
1071 	int copied;
1072 	size_t len;
1073 	char *result;
1074 
1075 	if (cltrack_legacy_disable)
1076 		return NULL;
1077 
1078 	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1079 		strlen(nfs4_recoverydir()) + 1;
1080 
1081 	result = kmalloc(len, GFP_KERNEL);
1082 	if (!result)
1083 		return result;
1084 
1085 	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1086 				nfs4_recoverydir());
1087 	if (copied >= len) {
1088 		/* just return nothing if output was truncated */
1089 		kfree(result);
1090 		return NULL;
1091 	}
1092 
1093 	return result;
1094 }
1095 
1096 static char *
nfsd4_cltrack_legacy_recdir(const struct xdr_netobj * name)1097 nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1098 {
1099 	int copied;
1100 	size_t len;
1101 	char *result;
1102 
1103 	if (cltrack_legacy_disable)
1104 		return NULL;
1105 
1106 	/* +1 is for '/' between "topdir" and "recdir" */
1107 	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1108 		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1109 
1110 	result = kmalloc(len, GFP_KERNEL);
1111 	if (!result)
1112 		return result;
1113 
1114 	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1115 				nfs4_recoverydir());
1116 	if (copied > (len - HEXDIR_LEN)) {
1117 		/* just return nothing if output will be truncated */
1118 		kfree(result);
1119 		return NULL;
1120 	}
1121 
1122 	copied = nfs4_make_rec_clidname(result + copied, name);
1123 	if (copied) {
1124 		kfree(result);
1125 		return NULL;
1126 	}
1127 
1128 	return result;
1129 }
1130 
1131 static int
nfsd4_umh_cltrack_upcall(char * cmd,char * arg,char * legacy)1132 nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *legacy)
1133 {
1134 	char *envp[2];
1135 	char *argv[4];
1136 	int ret;
1137 
1138 	if (unlikely(!cltrack_prog[0])) {
1139 		dprintk("%s: cltrack_prog is disabled\n", __func__);
1140 		return -EACCES;
1141 	}
1142 
1143 	dprintk("%s: cmd: %s\n", __func__, cmd);
1144 	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1145 	dprintk("%s: legacy: %s\n", __func__, legacy ? legacy : "(null)");
1146 
1147 	envp[0] = legacy;
1148 	envp[1] = NULL;
1149 
1150 	argv[0] = (char *)cltrack_prog;
1151 	argv[1] = cmd;
1152 	argv[2] = arg;
1153 	argv[3] = NULL;
1154 
1155 	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1156 	/*
1157 	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1158 	 * error. The admin can re-enable it on the fly by using sysfs
1159 	 * once the problem has been fixed.
1160 	 */
1161 	if (ret == -ENOENT || ret == -EACCES) {
1162 		dprintk("NFSD: %s was not found or isn't executable (%d). "
1163 			"Setting cltrack_prog to blank string!",
1164 			cltrack_prog, ret);
1165 		cltrack_prog[0] = '\0';
1166 	}
1167 	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1168 
1169 	return ret;
1170 }
1171 
1172 static char *
bin_to_hex_dup(const unsigned char * src,int srclen)1173 bin_to_hex_dup(const unsigned char *src, int srclen)
1174 {
1175 	int i;
1176 	char *buf, *hex;
1177 
1178 	/* +1 for terminating NULL */
1179 	buf = kmalloc((srclen * 2) + 1, GFP_KERNEL);
1180 	if (!buf)
1181 		return buf;
1182 
1183 	hex = buf;
1184 	for (i = 0; i < srclen; i++) {
1185 		sprintf(hex, "%2.2x", *src++);
1186 		hex += 2;
1187 	}
1188 	return buf;
1189 }
1190 
1191 static int
nfsd4_umh_cltrack_init(struct net * net)1192 nfsd4_umh_cltrack_init(struct net __attribute__((unused)) *net)
1193 {
1194 	/* XXX: The usermode helper s not working in container yet. */
1195 	if (net != &init_net) {
1196 		WARN(1, KERN_ERR "NFSD: attempt to initialize umh client "
1197 			"tracking in a container!\n");
1198 		return -EINVAL;
1199 	}
1200 	return nfsd4_umh_cltrack_upcall("init", NULL, NULL);
1201 }
1202 
1203 static void
nfsd4_umh_cltrack_create(struct nfs4_client * clp)1204 nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1205 {
1206 	char *hexid;
1207 
1208 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1209 	if (!hexid) {
1210 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1211 		return;
1212 	}
1213 	nfsd4_umh_cltrack_upcall("create", hexid, NULL);
1214 	kfree(hexid);
1215 }
1216 
1217 static void
nfsd4_umh_cltrack_remove(struct nfs4_client * clp)1218 nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1219 {
1220 	char *hexid;
1221 
1222 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1223 	if (!hexid) {
1224 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1225 		return;
1226 	}
1227 	nfsd4_umh_cltrack_upcall("remove", hexid, NULL);
1228 	kfree(hexid);
1229 }
1230 
1231 static int
nfsd4_umh_cltrack_check(struct nfs4_client * clp)1232 nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1233 {
1234 	int ret;
1235 	char *hexid, *legacy;
1236 
1237 	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1238 	if (!hexid) {
1239 		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1240 		return -ENOMEM;
1241 	}
1242 	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1243 	ret = nfsd4_umh_cltrack_upcall("check", hexid, legacy);
1244 	kfree(legacy);
1245 	kfree(hexid);
1246 	return ret;
1247 }
1248 
1249 static void
nfsd4_umh_cltrack_grace_done(struct nfsd_net * nn,time_t boot_time)1250 nfsd4_umh_cltrack_grace_done(struct nfsd_net __attribute__((unused)) *nn,
1251 				time_t boot_time)
1252 {
1253 	char *legacy;
1254 	char timestr[22]; /* FIXME: better way to determine max size? */
1255 
1256 	sprintf(timestr, "%ld", boot_time);
1257 	legacy = nfsd4_cltrack_legacy_topdir();
1258 	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy);
1259 	kfree(legacy);
1260 }
1261 
1262 static struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1263 	.init		= nfsd4_umh_cltrack_init,
1264 	.exit		= NULL,
1265 	.create		= nfsd4_umh_cltrack_create,
1266 	.remove		= nfsd4_umh_cltrack_remove,
1267 	.check		= nfsd4_umh_cltrack_check,
1268 	.grace_done	= nfsd4_umh_cltrack_grace_done,
1269 };
1270 
1271 int
nfsd4_client_tracking_init(struct net * net)1272 nfsd4_client_tracking_init(struct net *net)
1273 {
1274 	int status;
1275 	struct path path;
1276 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1277 
1278 	/* just run the init if it the method is already decided */
1279 	if (nn->client_tracking_ops)
1280 		goto do_init;
1281 
1282 	/*
1283 	 * First, try a UMH upcall. It should succeed or fail quickly, so
1284 	 * there's little harm in trying that first.
1285 	 */
1286 	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
1287 	status = nn->client_tracking_ops->init(net);
1288 	if (!status)
1289 		return status;
1290 
1291 	/*
1292 	 * See if the recoverydir exists and is a directory. If it is,
1293 	 * then use the legacy ops.
1294 	 */
1295 	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
1296 	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
1297 	if (!status) {
1298 		status = S_ISDIR(path.dentry->d_inode->i_mode);
1299 		path_put(&path);
1300 		if (status)
1301 			goto do_init;
1302 	}
1303 
1304 	/* Finally, try to use nfsdcld */
1305 	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1306 	printk(KERN_WARNING "NFSD: the nfsdcld client tracking upcall will be "
1307 			"removed in 3.10. Please transition to using "
1308 			"nfsdcltrack.\n");
1309 do_init:
1310 	status = nn->client_tracking_ops->init(net);
1311 	if (status) {
1312 		printk(KERN_WARNING "NFSD: Unable to initialize client "
1313 				    "recovery tracking! (%d)\n", status);
1314 		nn->client_tracking_ops = NULL;
1315 	}
1316 	return status;
1317 }
1318 
1319 void
nfsd4_client_tracking_exit(struct net * net)1320 nfsd4_client_tracking_exit(struct net *net)
1321 {
1322 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1323 
1324 	if (nn->client_tracking_ops) {
1325 		if (nn->client_tracking_ops->exit)
1326 			nn->client_tracking_ops->exit(net);
1327 		nn->client_tracking_ops = NULL;
1328 	}
1329 }
1330 
1331 void
nfsd4_client_record_create(struct nfs4_client * clp)1332 nfsd4_client_record_create(struct nfs4_client *clp)
1333 {
1334 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1335 
1336 	if (nn->client_tracking_ops)
1337 		nn->client_tracking_ops->create(clp);
1338 }
1339 
1340 void
nfsd4_client_record_remove(struct nfs4_client * clp)1341 nfsd4_client_record_remove(struct nfs4_client *clp)
1342 {
1343 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1344 
1345 	if (nn->client_tracking_ops)
1346 		nn->client_tracking_ops->remove(clp);
1347 }
1348 
1349 int
nfsd4_client_record_check(struct nfs4_client * clp)1350 nfsd4_client_record_check(struct nfs4_client *clp)
1351 {
1352 	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1353 
1354 	if (nn->client_tracking_ops)
1355 		return nn->client_tracking_ops->check(clp);
1356 
1357 	return -EOPNOTSUPP;
1358 }
1359 
1360 void
nfsd4_record_grace_done(struct nfsd_net * nn,time_t boot_time)1361 nfsd4_record_grace_done(struct nfsd_net *nn, time_t boot_time)
1362 {
1363 	if (nn->client_tracking_ops)
1364 		nn->client_tracking_ops->grace_done(nn, boot_time);
1365 }
1366 
1367 static int
rpc_pipefs_event(struct notifier_block * nb,unsigned long event,void * ptr)1368 rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
1369 {
1370 	struct super_block *sb = ptr;
1371 	struct net *net = sb->s_fs_info;
1372 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1373 	struct cld_net *cn = nn->cld_net;
1374 	struct dentry *dentry;
1375 	int ret = 0;
1376 
1377 	if (!try_module_get(THIS_MODULE))
1378 		return 0;
1379 
1380 	if (!cn) {
1381 		module_put(THIS_MODULE);
1382 		return 0;
1383 	}
1384 
1385 	switch (event) {
1386 	case RPC_PIPEFS_MOUNT:
1387 		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
1388 		if (IS_ERR(dentry)) {
1389 			ret = PTR_ERR(dentry);
1390 			break;
1391 		}
1392 		cn->cn_pipe->dentry = dentry;
1393 		break;
1394 	case RPC_PIPEFS_UMOUNT:
1395 		if (cn->cn_pipe->dentry)
1396 			nfsd4_cld_unregister_sb(cn->cn_pipe);
1397 		break;
1398 	default:
1399 		ret = -ENOTSUPP;
1400 		break;
1401 	}
1402 	module_put(THIS_MODULE);
1403 	return ret;
1404 }
1405 
1406 static struct notifier_block nfsd4_cld_block = {
1407 	.notifier_call = rpc_pipefs_event,
1408 };
1409 
1410 int
register_cld_notifier(void)1411 register_cld_notifier(void)
1412 {
1413 	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
1414 }
1415 
1416 void
unregister_cld_notifier(void)1417 unregister_cld_notifier(void)
1418 {
1419 	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
1420 }
1421