xref: /openbmc/linux/drivers/block/drbd/drbd_nl.c (revision f35e839a)
1 /*
2    drbd_nl.c
3 
4    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
5 
6    Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
7    Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
8    Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
9 
10    drbd is free software; you can redistribute it and/or modify
11    it under the terms of the GNU General Public License as published by
12    the Free Software Foundation; either version 2, or (at your option)
13    any later version.
14 
15    drbd is distributed in the hope that it will be useful,
16    but WITHOUT ANY WARRANTY; without even the implied warranty of
17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18    GNU General Public License for more details.
19 
20    You should have received a copy of the GNU General Public License
21    along with drbd; see the file COPYING.  If not, write to
22    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23 
24  */
25 
26 #include <linux/module.h>
27 #include <linux/drbd.h>
28 #include <linux/in.h>
29 #include <linux/fs.h>
30 #include <linux/file.h>
31 #include <linux/slab.h>
32 #include <linux/blkpg.h>
33 #include <linux/cpumask.h>
34 #include "drbd_int.h"
35 #include "drbd_req.h"
36 #include "drbd_wrappers.h"
37 #include <asm/unaligned.h>
38 #include <linux/drbd_limits.h>
39 #include <linux/kthread.h>
40 
41 #include <net/genetlink.h>
42 
43 /* .doit */
44 // int drbd_adm_create_resource(struct sk_buff *skb, struct genl_info *info);
45 // int drbd_adm_delete_resource(struct sk_buff *skb, struct genl_info *info);
46 
47 int drbd_adm_add_minor(struct sk_buff *skb, struct genl_info *info);
48 int drbd_adm_delete_minor(struct sk_buff *skb, struct genl_info *info);
49 
50 int drbd_adm_new_resource(struct sk_buff *skb, struct genl_info *info);
51 int drbd_adm_del_resource(struct sk_buff *skb, struct genl_info *info);
52 int drbd_adm_down(struct sk_buff *skb, struct genl_info *info);
53 
54 int drbd_adm_set_role(struct sk_buff *skb, struct genl_info *info);
55 int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info);
56 int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info);
57 int drbd_adm_detach(struct sk_buff *skb, struct genl_info *info);
58 int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info);
59 int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info);
60 int drbd_adm_resize(struct sk_buff *skb, struct genl_info *info);
61 int drbd_adm_start_ov(struct sk_buff *skb, struct genl_info *info);
62 int drbd_adm_new_c_uuid(struct sk_buff *skb, struct genl_info *info);
63 int drbd_adm_disconnect(struct sk_buff *skb, struct genl_info *info);
64 int drbd_adm_invalidate(struct sk_buff *skb, struct genl_info *info);
65 int drbd_adm_invalidate_peer(struct sk_buff *skb, struct genl_info *info);
66 int drbd_adm_pause_sync(struct sk_buff *skb, struct genl_info *info);
67 int drbd_adm_resume_sync(struct sk_buff *skb, struct genl_info *info);
68 int drbd_adm_suspend_io(struct sk_buff *skb, struct genl_info *info);
69 int drbd_adm_resume_io(struct sk_buff *skb, struct genl_info *info);
70 int drbd_adm_outdate(struct sk_buff *skb, struct genl_info *info);
71 int drbd_adm_resource_opts(struct sk_buff *skb, struct genl_info *info);
72 int drbd_adm_get_status(struct sk_buff *skb, struct genl_info *info);
73 int drbd_adm_get_timeout_type(struct sk_buff *skb, struct genl_info *info);
74 /* .dumpit */
75 int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb);
76 
77 #include <linux/drbd_genl_api.h>
78 #include "drbd_nla.h"
79 #include <linux/genl_magic_func.h>
80 
81 /* used blkdev_get_by_path, to claim our meta data device(s) */
82 static char *drbd_m_holder = "Hands off! this is DRBD's meta data device.";
83 
84 /* Configuration is strictly serialized, because generic netlink message
85  * processing is strictly serialized by the genl_lock().
86  * Which means we can use one static global drbd_config_context struct.
87  */
88 static struct drbd_config_context {
89 	/* assigned from drbd_genlmsghdr */
90 	unsigned int minor;
91 	/* assigned from request attributes, if present */
92 	unsigned int volume;
93 #define VOLUME_UNSPECIFIED		(-1U)
94 	/* pointer into the request skb,
95 	 * limited lifetime! */
96 	char *resource_name;
97 	struct nlattr *my_addr;
98 	struct nlattr *peer_addr;
99 
100 	/* reply buffer */
101 	struct sk_buff *reply_skb;
102 	/* pointer into reply buffer */
103 	struct drbd_genlmsghdr *reply_dh;
104 	/* resolved from attributes, if possible */
105 	struct drbd_conf *mdev;
106 	struct drbd_tconn *tconn;
107 } adm_ctx;
108 
109 static void drbd_adm_send_reply(struct sk_buff *skb, struct genl_info *info)
110 {
111 	genlmsg_end(skb, genlmsg_data(nlmsg_data(nlmsg_hdr(skb))));
112 	if (genlmsg_reply(skb, info))
113 		printk(KERN_ERR "drbd: error sending genl reply\n");
114 }
115 
116 /* Used on a fresh "drbd_adm_prepare"d reply_skb, this cannot fail: The only
117  * reason it could fail was no space in skb, and there are 4k available. */
118 int drbd_msg_put_info(const char *info)
119 {
120 	struct sk_buff *skb = adm_ctx.reply_skb;
121 	struct nlattr *nla;
122 	int err = -EMSGSIZE;
123 
124 	if (!info || !info[0])
125 		return 0;
126 
127 	nla = nla_nest_start(skb, DRBD_NLA_CFG_REPLY);
128 	if (!nla)
129 		return err;
130 
131 	err = nla_put_string(skb, T_info_text, info);
132 	if (err) {
133 		nla_nest_cancel(skb, nla);
134 		return err;
135 	} else
136 		nla_nest_end(skb, nla);
137 	return 0;
138 }
139 
140 /* This would be a good candidate for a "pre_doit" hook,
141  * and per-family private info->pointers.
142  * But we need to stay compatible with older kernels.
143  * If it returns successfully, adm_ctx members are valid.
144  */
145 #define DRBD_ADM_NEED_MINOR	1
146 #define DRBD_ADM_NEED_RESOURCE	2
147 #define DRBD_ADM_NEED_CONNECTION 4
148 static int drbd_adm_prepare(struct sk_buff *skb, struct genl_info *info,
149 		unsigned flags)
150 {
151 	struct drbd_genlmsghdr *d_in = info->userhdr;
152 	const u8 cmd = info->genlhdr->cmd;
153 	int err;
154 
155 	memset(&adm_ctx, 0, sizeof(adm_ctx));
156 
157 	/* genl_rcv_msg only checks for CAP_NET_ADMIN on "GENL_ADMIN_PERM" :( */
158 	if (cmd != DRBD_ADM_GET_STATUS && !capable(CAP_NET_ADMIN))
159 	       return -EPERM;
160 
161 	adm_ctx.reply_skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
162 	if (!adm_ctx.reply_skb) {
163 		err = -ENOMEM;
164 		goto fail;
165 	}
166 
167 	adm_ctx.reply_dh = genlmsg_put_reply(adm_ctx.reply_skb,
168 					info, &drbd_genl_family, 0, cmd);
169 	/* put of a few bytes into a fresh skb of >= 4k will always succeed.
170 	 * but anyways */
171 	if (!adm_ctx.reply_dh) {
172 		err = -ENOMEM;
173 		goto fail;
174 	}
175 
176 	adm_ctx.reply_dh->minor = d_in->minor;
177 	adm_ctx.reply_dh->ret_code = NO_ERROR;
178 
179 	adm_ctx.volume = VOLUME_UNSPECIFIED;
180 	if (info->attrs[DRBD_NLA_CFG_CONTEXT]) {
181 		struct nlattr *nla;
182 		/* parse and validate only */
183 		err = drbd_cfg_context_from_attrs(NULL, info);
184 		if (err)
185 			goto fail;
186 
187 		/* It was present, and valid,
188 		 * copy it over to the reply skb. */
189 		err = nla_put_nohdr(adm_ctx.reply_skb,
190 				info->attrs[DRBD_NLA_CFG_CONTEXT]->nla_len,
191 				info->attrs[DRBD_NLA_CFG_CONTEXT]);
192 		if (err)
193 			goto fail;
194 
195 		/* and assign stuff to the global adm_ctx */
196 		nla = nested_attr_tb[__nla_type(T_ctx_volume)];
197 		if (nla)
198 			adm_ctx.volume = nla_get_u32(nla);
199 		nla = nested_attr_tb[__nla_type(T_ctx_resource_name)];
200 		if (nla)
201 			adm_ctx.resource_name = nla_data(nla);
202 		adm_ctx.my_addr = nested_attr_tb[__nla_type(T_ctx_my_addr)];
203 		adm_ctx.peer_addr = nested_attr_tb[__nla_type(T_ctx_peer_addr)];
204 		if ((adm_ctx.my_addr &&
205 		     nla_len(adm_ctx.my_addr) > sizeof(adm_ctx.tconn->my_addr)) ||
206 		    (adm_ctx.peer_addr &&
207 		     nla_len(adm_ctx.peer_addr) > sizeof(adm_ctx.tconn->peer_addr))) {
208 			err = -EINVAL;
209 			goto fail;
210 		}
211 	}
212 
213 	adm_ctx.minor = d_in->minor;
214 	adm_ctx.mdev = minor_to_mdev(d_in->minor);
215 	adm_ctx.tconn = conn_get_by_name(adm_ctx.resource_name);
216 
217 	if (!adm_ctx.mdev && (flags & DRBD_ADM_NEED_MINOR)) {
218 		drbd_msg_put_info("unknown minor");
219 		return ERR_MINOR_INVALID;
220 	}
221 	if (!adm_ctx.tconn && (flags & DRBD_ADM_NEED_RESOURCE)) {
222 		drbd_msg_put_info("unknown resource");
223 		return ERR_INVALID_REQUEST;
224 	}
225 
226 	if (flags & DRBD_ADM_NEED_CONNECTION) {
227 		if (adm_ctx.tconn && !(flags & DRBD_ADM_NEED_RESOURCE)) {
228 			drbd_msg_put_info("no resource name expected");
229 			return ERR_INVALID_REQUEST;
230 		}
231 		if (adm_ctx.mdev) {
232 			drbd_msg_put_info("no minor number expected");
233 			return ERR_INVALID_REQUEST;
234 		}
235 		if (adm_ctx.my_addr && adm_ctx.peer_addr)
236 			adm_ctx.tconn = conn_get_by_addrs(nla_data(adm_ctx.my_addr),
237 							  nla_len(adm_ctx.my_addr),
238 							  nla_data(adm_ctx.peer_addr),
239 							  nla_len(adm_ctx.peer_addr));
240 		if (!adm_ctx.tconn) {
241 			drbd_msg_put_info("unknown connection");
242 			return ERR_INVALID_REQUEST;
243 		}
244 	}
245 
246 	/* some more paranoia, if the request was over-determined */
247 	if (adm_ctx.mdev && adm_ctx.tconn &&
248 	    adm_ctx.mdev->tconn != adm_ctx.tconn) {
249 		pr_warning("request: minor=%u, resource=%s; but that minor belongs to connection %s\n",
250 				adm_ctx.minor, adm_ctx.resource_name,
251 				adm_ctx.mdev->tconn->name);
252 		drbd_msg_put_info("minor exists in different resource");
253 		return ERR_INVALID_REQUEST;
254 	}
255 	if (adm_ctx.mdev &&
256 	    adm_ctx.volume != VOLUME_UNSPECIFIED &&
257 	    adm_ctx.volume != adm_ctx.mdev->vnr) {
258 		pr_warning("request: minor=%u, volume=%u; but that minor is volume %u in %s\n",
259 				adm_ctx.minor, adm_ctx.volume,
260 				adm_ctx.mdev->vnr, adm_ctx.mdev->tconn->name);
261 		drbd_msg_put_info("minor exists as different volume");
262 		return ERR_INVALID_REQUEST;
263 	}
264 
265 	return NO_ERROR;
266 
267 fail:
268 	nlmsg_free(adm_ctx.reply_skb);
269 	adm_ctx.reply_skb = NULL;
270 	return err;
271 }
272 
273 static int drbd_adm_finish(struct genl_info *info, int retcode)
274 {
275 	if (adm_ctx.tconn) {
276 		kref_put(&adm_ctx.tconn->kref, &conn_destroy);
277 		adm_ctx.tconn = NULL;
278 	}
279 
280 	if (!adm_ctx.reply_skb)
281 		return -ENOMEM;
282 
283 	adm_ctx.reply_dh->ret_code = retcode;
284 	drbd_adm_send_reply(adm_ctx.reply_skb, info);
285 	return 0;
286 }
287 
288 static void setup_khelper_env(struct drbd_tconn *tconn, char **envp)
289 {
290 	char *afs;
291 
292 	/* FIXME: A future version will not allow this case. */
293 	if (tconn->my_addr_len == 0 || tconn->peer_addr_len == 0)
294 		return;
295 
296 	switch (((struct sockaddr *)&tconn->peer_addr)->sa_family) {
297 	case AF_INET6:
298 		afs = "ipv6";
299 		snprintf(envp[4], 60, "DRBD_PEER_ADDRESS=%pI6",
300 			 &((struct sockaddr_in6 *)&tconn->peer_addr)->sin6_addr);
301 		break;
302 	case AF_INET:
303 		afs = "ipv4";
304 		snprintf(envp[4], 60, "DRBD_PEER_ADDRESS=%pI4",
305 			 &((struct sockaddr_in *)&tconn->peer_addr)->sin_addr);
306 		break;
307 	default:
308 		afs = "ssocks";
309 		snprintf(envp[4], 60, "DRBD_PEER_ADDRESS=%pI4",
310 			 &((struct sockaddr_in *)&tconn->peer_addr)->sin_addr);
311 	}
312 	snprintf(envp[3], 20, "DRBD_PEER_AF=%s", afs);
313 }
314 
315 int drbd_khelper(struct drbd_conf *mdev, char *cmd)
316 {
317 	char *envp[] = { "HOME=/",
318 			"TERM=linux",
319 			"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
320 			 (char[20]) { }, /* address family */
321 			 (char[60]) { }, /* address */
322 			NULL };
323 	char mb[12];
324 	char *argv[] = {usermode_helper, cmd, mb, NULL };
325 	struct drbd_tconn *tconn = mdev->tconn;
326 	struct sib_info sib;
327 	int ret;
328 
329 	if (current == tconn->worker.task)
330 		set_bit(CALLBACK_PENDING, &tconn->flags);
331 
332 	snprintf(mb, 12, "minor-%d", mdev_to_minor(mdev));
333 	setup_khelper_env(tconn, envp);
334 
335 	/* The helper may take some time.
336 	 * write out any unsynced meta data changes now */
337 	drbd_md_sync(mdev);
338 
339 	dev_info(DEV, "helper command: %s %s %s\n", usermode_helper, cmd, mb);
340 	sib.sib_reason = SIB_HELPER_PRE;
341 	sib.helper_name = cmd;
342 	drbd_bcast_event(mdev, &sib);
343 	ret = call_usermodehelper(usermode_helper, argv, envp, UMH_WAIT_PROC);
344 	if (ret)
345 		dev_warn(DEV, "helper command: %s %s %s exit code %u (0x%x)\n",
346 				usermode_helper, cmd, mb,
347 				(ret >> 8) & 0xff, ret);
348 	else
349 		dev_info(DEV, "helper command: %s %s %s exit code %u (0x%x)\n",
350 				usermode_helper, cmd, mb,
351 				(ret >> 8) & 0xff, ret);
352 	sib.sib_reason = SIB_HELPER_POST;
353 	sib.helper_exit_code = ret;
354 	drbd_bcast_event(mdev, &sib);
355 
356 	if (current == tconn->worker.task)
357 		clear_bit(CALLBACK_PENDING, &tconn->flags);
358 
359 	if (ret < 0) /* Ignore any ERRNOs we got. */
360 		ret = 0;
361 
362 	return ret;
363 }
364 
365 int conn_khelper(struct drbd_tconn *tconn, char *cmd)
366 {
367 	char *envp[] = { "HOME=/",
368 			"TERM=linux",
369 			"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
370 			 (char[20]) { }, /* address family */
371 			 (char[60]) { }, /* address */
372 			NULL };
373 	char *argv[] = {usermode_helper, cmd, tconn->name, NULL };
374 	int ret;
375 
376 	setup_khelper_env(tconn, envp);
377 	conn_md_sync(tconn);
378 
379 	conn_info(tconn, "helper command: %s %s %s\n", usermode_helper, cmd, tconn->name);
380 	/* TODO: conn_bcast_event() ?? */
381 
382 	ret = call_usermodehelper(usermode_helper, argv, envp, UMH_WAIT_PROC);
383 	if (ret)
384 		conn_warn(tconn, "helper command: %s %s %s exit code %u (0x%x)\n",
385 			  usermode_helper, cmd, tconn->name,
386 			  (ret >> 8) & 0xff, ret);
387 	else
388 		conn_info(tconn, "helper command: %s %s %s exit code %u (0x%x)\n",
389 			  usermode_helper, cmd, tconn->name,
390 			  (ret >> 8) & 0xff, ret);
391 	/* TODO: conn_bcast_event() ?? */
392 
393 	if (ret < 0) /* Ignore any ERRNOs we got. */
394 		ret = 0;
395 
396 	return ret;
397 }
398 
399 static enum drbd_fencing_p highest_fencing_policy(struct drbd_tconn *tconn)
400 {
401 	enum drbd_fencing_p fp = FP_NOT_AVAIL;
402 	struct drbd_conf *mdev;
403 	int vnr;
404 
405 	rcu_read_lock();
406 	idr_for_each_entry(&tconn->volumes, mdev, vnr) {
407 		if (get_ldev_if_state(mdev, D_CONSISTENT)) {
408 			fp = max_t(enum drbd_fencing_p, fp,
409 				   rcu_dereference(mdev->ldev->disk_conf)->fencing);
410 			put_ldev(mdev);
411 		}
412 	}
413 	rcu_read_unlock();
414 
415 	return fp;
416 }
417 
418 bool conn_try_outdate_peer(struct drbd_tconn *tconn)
419 {
420 	union drbd_state mask = { };
421 	union drbd_state val = { };
422 	enum drbd_fencing_p fp;
423 	char *ex_to_string;
424 	int r;
425 
426 	if (tconn->cstate >= C_WF_REPORT_PARAMS) {
427 		conn_err(tconn, "Expected cstate < C_WF_REPORT_PARAMS\n");
428 		return false;
429 	}
430 
431 	fp = highest_fencing_policy(tconn);
432 	switch (fp) {
433 	case FP_NOT_AVAIL:
434 		conn_warn(tconn, "Not fencing peer, I'm not even Consistent myself.\n");
435 		goto out;
436 	case FP_DONT_CARE:
437 		return true;
438 	default: ;
439 	}
440 
441 	r = conn_khelper(tconn, "fence-peer");
442 
443 	switch ((r>>8) & 0xff) {
444 	case 3: /* peer is inconsistent */
445 		ex_to_string = "peer is inconsistent or worse";
446 		mask.pdsk = D_MASK;
447 		val.pdsk = D_INCONSISTENT;
448 		break;
449 	case 4: /* peer got outdated, or was already outdated */
450 		ex_to_string = "peer was fenced";
451 		mask.pdsk = D_MASK;
452 		val.pdsk = D_OUTDATED;
453 		break;
454 	case 5: /* peer was down */
455 		if (conn_highest_disk(tconn) == D_UP_TO_DATE) {
456 			/* we will(have) create(d) a new UUID anyways... */
457 			ex_to_string = "peer is unreachable, assumed to be dead";
458 			mask.pdsk = D_MASK;
459 			val.pdsk = D_OUTDATED;
460 		} else {
461 			ex_to_string = "peer unreachable, doing nothing since disk != UpToDate";
462 		}
463 		break;
464 	case 6: /* Peer is primary, voluntarily outdate myself.
465 		 * This is useful when an unconnected R_SECONDARY is asked to
466 		 * become R_PRIMARY, but finds the other peer being active. */
467 		ex_to_string = "peer is active";
468 		conn_warn(tconn, "Peer is primary, outdating myself.\n");
469 		mask.disk = D_MASK;
470 		val.disk = D_OUTDATED;
471 		break;
472 	case 7:
473 		if (fp != FP_STONITH)
474 			conn_err(tconn, "fence-peer() = 7 && fencing != Stonith !!!\n");
475 		ex_to_string = "peer was stonithed";
476 		mask.pdsk = D_MASK;
477 		val.pdsk = D_OUTDATED;
478 		break;
479 	default:
480 		/* The script is broken ... */
481 		conn_err(tconn, "fence-peer helper broken, returned %d\n", (r>>8)&0xff);
482 		return false; /* Eventually leave IO frozen */
483 	}
484 
485 	conn_info(tconn, "fence-peer helper returned %d (%s)\n",
486 		  (r>>8) & 0xff, ex_to_string);
487 
488  out:
489 
490 	/* Not using
491 	   conn_request_state(tconn, mask, val, CS_VERBOSE);
492 	   here, because we might were able to re-establish the connection in the
493 	   meantime. */
494 	spin_lock_irq(&tconn->req_lock);
495 	if (tconn->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &tconn->flags))
496 		_conn_request_state(tconn, mask, val, CS_VERBOSE);
497 	spin_unlock_irq(&tconn->req_lock);
498 
499 	return conn_highest_pdsk(tconn) <= D_OUTDATED;
500 }
501 
502 static int _try_outdate_peer_async(void *data)
503 {
504 	struct drbd_tconn *tconn = (struct drbd_tconn *)data;
505 
506 	conn_try_outdate_peer(tconn);
507 
508 	kref_put(&tconn->kref, &conn_destroy);
509 	return 0;
510 }
511 
512 void conn_try_outdate_peer_async(struct drbd_tconn *tconn)
513 {
514 	struct task_struct *opa;
515 
516 	kref_get(&tconn->kref);
517 	opa = kthread_run(_try_outdate_peer_async, tconn, "drbd_async_h");
518 	if (IS_ERR(opa)) {
519 		conn_err(tconn, "out of mem, failed to invoke fence-peer helper\n");
520 		kref_put(&tconn->kref, &conn_destroy);
521 	}
522 }
523 
524 enum drbd_state_rv
525 drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force)
526 {
527 	const int max_tries = 4;
528 	enum drbd_state_rv rv = SS_UNKNOWN_ERROR;
529 	struct net_conf *nc;
530 	int try = 0;
531 	int forced = 0;
532 	union drbd_state mask, val;
533 
534 	if (new_role == R_PRIMARY)
535 		request_ping(mdev->tconn); /* Detect a dead peer ASAP */
536 
537 	mutex_lock(mdev->state_mutex);
538 
539 	mask.i = 0; mask.role = R_MASK;
540 	val.i  = 0; val.role  = new_role;
541 
542 	while (try++ < max_tries) {
543 		rv = _drbd_request_state(mdev, mask, val, CS_WAIT_COMPLETE);
544 
545 		/* in case we first succeeded to outdate,
546 		 * but now suddenly could establish a connection */
547 		if (rv == SS_CW_FAILED_BY_PEER && mask.pdsk != 0) {
548 			val.pdsk = 0;
549 			mask.pdsk = 0;
550 			continue;
551 		}
552 
553 		if (rv == SS_NO_UP_TO_DATE_DISK && force &&
554 		    (mdev->state.disk < D_UP_TO_DATE &&
555 		     mdev->state.disk >= D_INCONSISTENT)) {
556 			mask.disk = D_MASK;
557 			val.disk  = D_UP_TO_DATE;
558 			forced = 1;
559 			continue;
560 		}
561 
562 		if (rv == SS_NO_UP_TO_DATE_DISK &&
563 		    mdev->state.disk == D_CONSISTENT && mask.pdsk == 0) {
564 			D_ASSERT(mdev->state.pdsk == D_UNKNOWN);
565 
566 			if (conn_try_outdate_peer(mdev->tconn)) {
567 				val.disk = D_UP_TO_DATE;
568 				mask.disk = D_MASK;
569 			}
570 			continue;
571 		}
572 
573 		if (rv == SS_NOTHING_TO_DO)
574 			goto out;
575 		if (rv == SS_PRIMARY_NOP && mask.pdsk == 0) {
576 			if (!conn_try_outdate_peer(mdev->tconn) && force) {
577 				dev_warn(DEV, "Forced into split brain situation!\n");
578 				mask.pdsk = D_MASK;
579 				val.pdsk  = D_OUTDATED;
580 
581 			}
582 			continue;
583 		}
584 		if (rv == SS_TWO_PRIMARIES) {
585 			/* Maybe the peer is detected as dead very soon...
586 			   retry at most once more in this case. */
587 			int timeo;
588 			rcu_read_lock();
589 			nc = rcu_dereference(mdev->tconn->net_conf);
590 			timeo = nc ? (nc->ping_timeo + 1) * HZ / 10 : 1;
591 			rcu_read_unlock();
592 			schedule_timeout_interruptible(timeo);
593 			if (try < max_tries)
594 				try = max_tries - 1;
595 			continue;
596 		}
597 		if (rv < SS_SUCCESS) {
598 			rv = _drbd_request_state(mdev, mask, val,
599 						CS_VERBOSE + CS_WAIT_COMPLETE);
600 			if (rv < SS_SUCCESS)
601 				goto out;
602 		}
603 		break;
604 	}
605 
606 	if (rv < SS_SUCCESS)
607 		goto out;
608 
609 	if (forced)
610 		dev_warn(DEV, "Forced to consider local data as UpToDate!\n");
611 
612 	/* Wait until nothing is on the fly :) */
613 	wait_event(mdev->misc_wait, atomic_read(&mdev->ap_pending_cnt) == 0);
614 
615 	/* FIXME also wait for all pending P_BARRIER_ACK? */
616 
617 	if (new_role == R_SECONDARY) {
618 		set_disk_ro(mdev->vdisk, true);
619 		if (get_ldev(mdev)) {
620 			mdev->ldev->md.uuid[UI_CURRENT] &= ~(u64)1;
621 			put_ldev(mdev);
622 		}
623 	} else {
624 		mutex_lock(&mdev->tconn->conf_update);
625 		nc = mdev->tconn->net_conf;
626 		if (nc)
627 			nc->discard_my_data = 0; /* without copy; single bit op is atomic */
628 		mutex_unlock(&mdev->tconn->conf_update);
629 
630 		set_disk_ro(mdev->vdisk, false);
631 		if (get_ldev(mdev)) {
632 			if (((mdev->state.conn < C_CONNECTED ||
633 			       mdev->state.pdsk <= D_FAILED)
634 			      && mdev->ldev->md.uuid[UI_BITMAP] == 0) || forced)
635 				drbd_uuid_new_current(mdev);
636 
637 			mdev->ldev->md.uuid[UI_CURRENT] |=  (u64)1;
638 			put_ldev(mdev);
639 		}
640 	}
641 
642 	/* writeout of activity log covered areas of the bitmap
643 	 * to stable storage done in after state change already */
644 
645 	if (mdev->state.conn >= C_WF_REPORT_PARAMS) {
646 		/* if this was forced, we should consider sync */
647 		if (forced)
648 			drbd_send_uuids(mdev);
649 		drbd_send_current_state(mdev);
650 	}
651 
652 	drbd_md_sync(mdev);
653 
654 	kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
655 out:
656 	mutex_unlock(mdev->state_mutex);
657 	return rv;
658 }
659 
660 static const char *from_attrs_err_to_txt(int err)
661 {
662 	return	err == -ENOMSG ? "required attribute missing" :
663 		err == -EOPNOTSUPP ? "unknown mandatory attribute" :
664 		err == -EEXIST ? "can not change invariant setting" :
665 		"invalid attribute value";
666 }
667 
668 int drbd_adm_set_role(struct sk_buff *skb, struct genl_info *info)
669 {
670 	struct set_role_parms parms;
671 	int err;
672 	enum drbd_ret_code retcode;
673 
674 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
675 	if (!adm_ctx.reply_skb)
676 		return retcode;
677 	if (retcode != NO_ERROR)
678 		goto out;
679 
680 	memset(&parms, 0, sizeof(parms));
681 	if (info->attrs[DRBD_NLA_SET_ROLE_PARMS]) {
682 		err = set_role_parms_from_attrs(&parms, info);
683 		if (err) {
684 			retcode = ERR_MANDATORY_TAG;
685 			drbd_msg_put_info(from_attrs_err_to_txt(err));
686 			goto out;
687 		}
688 	}
689 
690 	if (info->genlhdr->cmd == DRBD_ADM_PRIMARY)
691 		retcode = drbd_set_role(adm_ctx.mdev, R_PRIMARY, parms.assume_uptodate);
692 	else
693 		retcode = drbd_set_role(adm_ctx.mdev, R_SECONDARY, 0);
694 out:
695 	drbd_adm_finish(info, retcode);
696 	return 0;
697 }
698 
699 /* Initializes the md.*_offset members, so we are able to find
700  * the on disk meta data.
701  *
702  * We currently have two possible layouts:
703  * external:
704  *   |----------- md_size_sect ------------------|
705  *   [ 4k superblock ][ activity log ][  Bitmap  ]
706  *   | al_offset == 8 |
707  *   | bm_offset = al_offset + X      |
708  *  ==> bitmap sectors = md_size_sect - bm_offset
709  *
710  * internal:
711  *            |----------- md_size_sect ------------------|
712  * [data.....][  Bitmap  ][ activity log ][ 4k superblock ]
713  *                        | al_offset < 0 |
714  *            | bm_offset = al_offset - Y |
715  *  ==> bitmap sectors = Y = al_offset - bm_offset
716  *
717  *  Activity log size used to be fixed 32kB,
718  *  but is about to become configurable.
719  */
720 static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
721 				       struct drbd_backing_dev *bdev)
722 {
723 	sector_t md_size_sect = 0;
724 	unsigned int al_size_sect = bdev->md.al_size_4k * 8;
725 
726 	bdev->md.md_offset = drbd_md_ss(bdev);
727 
728 	switch (bdev->md.meta_dev_idx) {
729 	default:
730 		/* v07 style fixed size indexed meta data */
731 		bdev->md.md_size_sect = MD_128MB_SECT;
732 		bdev->md.al_offset = MD_4kB_SECT;
733 		bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
734 		break;
735 	case DRBD_MD_INDEX_FLEX_EXT:
736 		/* just occupy the full device; unit: sectors */
737 		bdev->md.md_size_sect = drbd_get_capacity(bdev->md_bdev);
738 		bdev->md.al_offset = MD_4kB_SECT;
739 		bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
740 		break;
741 	case DRBD_MD_INDEX_INTERNAL:
742 	case DRBD_MD_INDEX_FLEX_INT:
743 		/* al size is still fixed */
744 		bdev->md.al_offset = -al_size_sect;
745 		/* we need (slightly less than) ~ this much bitmap sectors: */
746 		md_size_sect = drbd_get_capacity(bdev->backing_bdev);
747 		md_size_sect = ALIGN(md_size_sect, BM_SECT_PER_EXT);
748 		md_size_sect = BM_SECT_TO_EXT(md_size_sect);
749 		md_size_sect = ALIGN(md_size_sect, 8);
750 
751 		/* plus the "drbd meta data super block",
752 		 * and the activity log; */
753 		md_size_sect += MD_4kB_SECT + al_size_sect;
754 
755 		bdev->md.md_size_sect = md_size_sect;
756 		/* bitmap offset is adjusted by 'super' block size */
757 		bdev->md.bm_offset   = -md_size_sect + MD_4kB_SECT;
758 		break;
759 	}
760 }
761 
762 /* input size is expected to be in KB */
763 char *ppsize(char *buf, unsigned long long size)
764 {
765 	/* Needs 9 bytes at max including trailing NUL:
766 	 * -1ULL ==> "16384 EB" */
767 	static char units[] = { 'K', 'M', 'G', 'T', 'P', 'E' };
768 	int base = 0;
769 	while (size >= 10000 && base < sizeof(units)-1) {
770 		/* shift + round */
771 		size = (size >> 10) + !!(size & (1<<9));
772 		base++;
773 	}
774 	sprintf(buf, "%u %cB", (unsigned)size, units[base]);
775 
776 	return buf;
777 }
778 
779 /* there is still a theoretical deadlock when called from receiver
780  * on an D_INCONSISTENT R_PRIMARY:
781  *  remote READ does inc_ap_bio, receiver would need to receive answer
782  *  packet from remote to dec_ap_bio again.
783  *  receiver receive_sizes(), comes here,
784  *  waits for ap_bio_cnt == 0. -> deadlock.
785  * but this cannot happen, actually, because:
786  *  R_PRIMARY D_INCONSISTENT, and peer's disk is unreachable
787  *  (not connected, or bad/no disk on peer):
788  *  see drbd_fail_request_early, ap_bio_cnt is zero.
789  *  R_PRIMARY D_INCONSISTENT, and C_SYNC_TARGET:
790  *  peer may not initiate a resize.
791  */
792 /* Note these are not to be confused with
793  * drbd_adm_suspend_io/drbd_adm_resume_io,
794  * which are (sub) state changes triggered by admin (drbdsetup),
795  * and can be long lived.
796  * This changes an mdev->flag, is triggered by drbd internals,
797  * and should be short-lived. */
798 void drbd_suspend_io(struct drbd_conf *mdev)
799 {
800 	set_bit(SUSPEND_IO, &mdev->flags);
801 	if (drbd_suspended(mdev))
802 		return;
803 	wait_event(mdev->misc_wait, !atomic_read(&mdev->ap_bio_cnt));
804 }
805 
806 void drbd_resume_io(struct drbd_conf *mdev)
807 {
808 	clear_bit(SUSPEND_IO, &mdev->flags);
809 	wake_up(&mdev->misc_wait);
810 }
811 
812 /**
813  * drbd_determine_dev_size() -  Sets the right device size obeying all constraints
814  * @mdev:	DRBD device.
815  *
816  * Returns 0 on success, negative return values indicate errors.
817  * You should call drbd_md_sync() after calling this function.
818  */
819 enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *mdev, enum dds_flags flags) __must_hold(local)
820 {
821 	sector_t prev_first_sect, prev_size; /* previous meta location */
822 	sector_t la_size_sect, u_size;
823 	sector_t size;
824 	char ppb[10];
825 
826 	int md_moved, la_size_changed;
827 	enum determine_dev_size rv = unchanged;
828 
829 	/* race:
830 	 * application request passes inc_ap_bio,
831 	 * but then cannot get an AL-reference.
832 	 * this function later may wait on ap_bio_cnt == 0. -> deadlock.
833 	 *
834 	 * to avoid that:
835 	 * Suspend IO right here.
836 	 * still lock the act_log to not trigger ASSERTs there.
837 	 */
838 	drbd_suspend_io(mdev);
839 
840 	/* no wait necessary anymore, actually we could assert that */
841 	wait_event(mdev->al_wait, lc_try_lock(mdev->act_log));
842 
843 	prev_first_sect = drbd_md_first_sector(mdev->ldev);
844 	prev_size = mdev->ldev->md.md_size_sect;
845 	la_size_sect = mdev->ldev->md.la_size_sect;
846 
847 	/* TODO: should only be some assert here, not (re)init... */
848 	drbd_md_set_sector_offsets(mdev, mdev->ldev);
849 
850 	rcu_read_lock();
851 	u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
852 	rcu_read_unlock();
853 	size = drbd_new_dev_size(mdev, mdev->ldev, u_size, flags & DDSF_FORCED);
854 
855 	if (drbd_get_capacity(mdev->this_bdev) != size ||
856 	    drbd_bm_capacity(mdev) != size) {
857 		int err;
858 		err = drbd_bm_resize(mdev, size, !(flags & DDSF_NO_RESYNC));
859 		if (unlikely(err)) {
860 			/* currently there is only one error: ENOMEM! */
861 			size = drbd_bm_capacity(mdev)>>1;
862 			if (size == 0) {
863 				dev_err(DEV, "OUT OF MEMORY! "
864 				    "Could not allocate bitmap!\n");
865 			} else {
866 				dev_err(DEV, "BM resizing failed. "
867 				    "Leaving size unchanged at size = %lu KB\n",
868 				    (unsigned long)size);
869 			}
870 			rv = dev_size_error;
871 		}
872 		/* racy, see comments above. */
873 		drbd_set_my_capacity(mdev, size);
874 		mdev->ldev->md.la_size_sect = size;
875 		dev_info(DEV, "size = %s (%llu KB)\n", ppsize(ppb, size>>1),
876 		     (unsigned long long)size>>1);
877 	}
878 	if (rv == dev_size_error)
879 		goto out;
880 
881 	la_size_changed = (la_size_sect != mdev->ldev->md.la_size_sect);
882 
883 	md_moved = prev_first_sect != drbd_md_first_sector(mdev->ldev)
884 		|| prev_size	   != mdev->ldev->md.md_size_sect;
885 
886 	if (la_size_changed || md_moved) {
887 		int err;
888 
889 		drbd_al_shrink(mdev); /* All extents inactive. */
890 		dev_info(DEV, "Writing the whole bitmap, %s\n",
891 			 la_size_changed && md_moved ? "size changed and md moved" :
892 			 la_size_changed ? "size changed" : "md moved");
893 		/* next line implicitly does drbd_suspend_io()+drbd_resume_io() */
894 		err = drbd_bitmap_io(mdev, md_moved ? &drbd_bm_write_all : &drbd_bm_write,
895 				     "size changed", BM_LOCKED_MASK);
896 		if (err) {
897 			rv = dev_size_error;
898 			goto out;
899 		}
900 		drbd_md_mark_dirty(mdev);
901 	}
902 
903 	if (size > la_size_sect)
904 		rv = grew;
905 	if (size < la_size_sect)
906 		rv = shrunk;
907 out:
908 	lc_unlock(mdev->act_log);
909 	wake_up(&mdev->al_wait);
910 	drbd_resume_io(mdev);
911 
912 	return rv;
913 }
914 
915 sector_t
916 drbd_new_dev_size(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
917 		  sector_t u_size, int assume_peer_has_space)
918 {
919 	sector_t p_size = mdev->p_size;   /* partner's disk size. */
920 	sector_t la_size_sect = bdev->md.la_size_sect; /* last agreed size. */
921 	sector_t m_size; /* my size */
922 	sector_t size = 0;
923 
924 	m_size = drbd_get_max_capacity(bdev);
925 
926 	if (mdev->state.conn < C_CONNECTED && assume_peer_has_space) {
927 		dev_warn(DEV, "Resize while not connected was forced by the user!\n");
928 		p_size = m_size;
929 	}
930 
931 	if (p_size && m_size) {
932 		size = min_t(sector_t, p_size, m_size);
933 	} else {
934 		if (la_size_sect) {
935 			size = la_size_sect;
936 			if (m_size && m_size < size)
937 				size = m_size;
938 			if (p_size && p_size < size)
939 				size = p_size;
940 		} else {
941 			if (m_size)
942 				size = m_size;
943 			if (p_size)
944 				size = p_size;
945 		}
946 	}
947 
948 	if (size == 0)
949 		dev_err(DEV, "Both nodes diskless!\n");
950 
951 	if (u_size) {
952 		if (u_size > size)
953 			dev_err(DEV, "Requested disk size is too big (%lu > %lu)\n",
954 			    (unsigned long)u_size>>1, (unsigned long)size>>1);
955 		else
956 			size = u_size;
957 	}
958 
959 	return size;
960 }
961 
962 /**
963  * drbd_check_al_size() - Ensures that the AL is of the right size
964  * @mdev:	DRBD device.
965  *
966  * Returns -EBUSY if current al lru is still used, -ENOMEM when allocation
967  * failed, and 0 on success. You should call drbd_md_sync() after you called
968  * this function.
969  */
970 static int drbd_check_al_size(struct drbd_conf *mdev, struct disk_conf *dc)
971 {
972 	struct lru_cache *n, *t;
973 	struct lc_element *e;
974 	unsigned int in_use;
975 	int i;
976 
977 	if (mdev->act_log &&
978 	    mdev->act_log->nr_elements == dc->al_extents)
979 		return 0;
980 
981 	in_use = 0;
982 	t = mdev->act_log;
983 	n = lc_create("act_log", drbd_al_ext_cache, AL_UPDATES_PER_TRANSACTION,
984 		dc->al_extents, sizeof(struct lc_element), 0);
985 
986 	if (n == NULL) {
987 		dev_err(DEV, "Cannot allocate act_log lru!\n");
988 		return -ENOMEM;
989 	}
990 	spin_lock_irq(&mdev->al_lock);
991 	if (t) {
992 		for (i = 0; i < t->nr_elements; i++) {
993 			e = lc_element_by_index(t, i);
994 			if (e->refcnt)
995 				dev_err(DEV, "refcnt(%d)==%d\n",
996 				    e->lc_number, e->refcnt);
997 			in_use += e->refcnt;
998 		}
999 	}
1000 	if (!in_use)
1001 		mdev->act_log = n;
1002 	spin_unlock_irq(&mdev->al_lock);
1003 	if (in_use) {
1004 		dev_err(DEV, "Activity log still in use!\n");
1005 		lc_destroy(n);
1006 		return -EBUSY;
1007 	} else {
1008 		if (t)
1009 			lc_destroy(t);
1010 	}
1011 	drbd_md_mark_dirty(mdev); /* we changed mdev->act_log->nr_elemens */
1012 	return 0;
1013 }
1014 
1015 static void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int max_bio_size)
1016 {
1017 	struct request_queue * const q = mdev->rq_queue;
1018 	unsigned int max_hw_sectors = max_bio_size >> 9;
1019 	unsigned int max_segments = 0;
1020 
1021 	if (get_ldev_if_state(mdev, D_ATTACHING)) {
1022 		struct request_queue * const b = mdev->ldev->backing_bdev->bd_disk->queue;
1023 
1024 		max_hw_sectors = min(queue_max_hw_sectors(b), max_bio_size >> 9);
1025 		rcu_read_lock();
1026 		max_segments = rcu_dereference(mdev->ldev->disk_conf)->max_bio_bvecs;
1027 		rcu_read_unlock();
1028 		put_ldev(mdev);
1029 	}
1030 
1031 	blk_queue_logical_block_size(q, 512);
1032 	blk_queue_max_hw_sectors(q, max_hw_sectors);
1033 	/* This is the workaround for "bio would need to, but cannot, be split" */
1034 	blk_queue_max_segments(q, max_segments ? max_segments : BLK_MAX_SEGMENTS);
1035 	blk_queue_segment_boundary(q, PAGE_CACHE_SIZE-1);
1036 
1037 	if (get_ldev_if_state(mdev, D_ATTACHING)) {
1038 		struct request_queue * const b = mdev->ldev->backing_bdev->bd_disk->queue;
1039 
1040 		blk_queue_stack_limits(q, b);
1041 
1042 		if (q->backing_dev_info.ra_pages != b->backing_dev_info.ra_pages) {
1043 			dev_info(DEV, "Adjusting my ra_pages to backing device's (%lu -> %lu)\n",
1044 				 q->backing_dev_info.ra_pages,
1045 				 b->backing_dev_info.ra_pages);
1046 			q->backing_dev_info.ra_pages = b->backing_dev_info.ra_pages;
1047 		}
1048 		put_ldev(mdev);
1049 	}
1050 }
1051 
1052 void drbd_reconsider_max_bio_size(struct drbd_conf *mdev)
1053 {
1054 	unsigned int now, new, local, peer;
1055 
1056 	now = queue_max_hw_sectors(mdev->rq_queue) << 9;
1057 	local = mdev->local_max_bio_size; /* Eventually last known value, from volatile memory */
1058 	peer = mdev->peer_max_bio_size; /* Eventually last known value, from meta data */
1059 
1060 	if (get_ldev_if_state(mdev, D_ATTACHING)) {
1061 		local = queue_max_hw_sectors(mdev->ldev->backing_bdev->bd_disk->queue) << 9;
1062 		mdev->local_max_bio_size = local;
1063 		put_ldev(mdev);
1064 	}
1065 	local = min(local, DRBD_MAX_BIO_SIZE);
1066 
1067 	/* We may ignore peer limits if the peer is modern enough.
1068 	   Because new from 8.3.8 onwards the peer can use multiple
1069 	   BIOs for a single peer_request */
1070 	if (mdev->state.conn >= C_CONNECTED) {
1071 		if (mdev->tconn->agreed_pro_version < 94)
1072 			peer = min( mdev->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
1073 			/* Correct old drbd (up to 8.3.7) if it believes it can do more than 32KiB */
1074 		else if (mdev->tconn->agreed_pro_version == 94)
1075 			peer = DRBD_MAX_SIZE_H80_PACKET;
1076 		else if (mdev->tconn->agreed_pro_version < 100)
1077 			peer = DRBD_MAX_BIO_SIZE_P95;  /* drbd 8.3.8 onwards, before 8.4.0 */
1078 		else
1079 			peer = DRBD_MAX_BIO_SIZE;
1080 	}
1081 
1082 	new = min(local, peer);
1083 
1084 	if (mdev->state.role == R_PRIMARY && new < now)
1085 		dev_err(DEV, "ASSERT FAILED new < now; (%u < %u)\n", new, now);
1086 
1087 	if (new != now)
1088 		dev_info(DEV, "max BIO size = %u\n", new);
1089 
1090 	drbd_setup_queue_param(mdev, new);
1091 }
1092 
1093 /* Starts the worker thread */
1094 static void conn_reconfig_start(struct drbd_tconn *tconn)
1095 {
1096 	drbd_thread_start(&tconn->worker);
1097 	conn_flush_workqueue(tconn);
1098 }
1099 
1100 /* if still unconfigured, stops worker again. */
1101 static void conn_reconfig_done(struct drbd_tconn *tconn)
1102 {
1103 	bool stop_threads;
1104 	spin_lock_irq(&tconn->req_lock);
1105 	stop_threads = conn_all_vols_unconf(tconn) &&
1106 		tconn->cstate == C_STANDALONE;
1107 	spin_unlock_irq(&tconn->req_lock);
1108 	if (stop_threads) {
1109 		/* asender is implicitly stopped by receiver
1110 		 * in conn_disconnect() */
1111 		drbd_thread_stop(&tconn->receiver);
1112 		drbd_thread_stop(&tconn->worker);
1113 	}
1114 }
1115 
1116 /* Make sure IO is suspended before calling this function(). */
1117 static void drbd_suspend_al(struct drbd_conf *mdev)
1118 {
1119 	int s = 0;
1120 
1121 	if (!lc_try_lock(mdev->act_log)) {
1122 		dev_warn(DEV, "Failed to lock al in drbd_suspend_al()\n");
1123 		return;
1124 	}
1125 
1126 	drbd_al_shrink(mdev);
1127 	spin_lock_irq(&mdev->tconn->req_lock);
1128 	if (mdev->state.conn < C_CONNECTED)
1129 		s = !test_and_set_bit(AL_SUSPENDED, &mdev->flags);
1130 	spin_unlock_irq(&mdev->tconn->req_lock);
1131 	lc_unlock(mdev->act_log);
1132 
1133 	if (s)
1134 		dev_info(DEV, "Suspended AL updates\n");
1135 }
1136 
1137 
1138 static bool should_set_defaults(struct genl_info *info)
1139 {
1140 	unsigned flags = ((struct drbd_genlmsghdr*)info->userhdr)->flags;
1141 	return 0 != (flags & DRBD_GENL_F_SET_DEFAULTS);
1142 }
1143 
1144 static unsigned int drbd_al_extents_max(struct drbd_backing_dev *bdev)
1145 {
1146 	/* This is limited by 16 bit "slot" numbers,
1147 	 * and by available on-disk context storage.
1148 	 *
1149 	 * Also (u16)~0 is special (denotes a "free" extent).
1150 	 *
1151 	 * One transaction occupies one 4kB on-disk block,
1152 	 * we have n such blocks in the on disk ring buffer,
1153 	 * the "current" transaction may fail (n-1),
1154 	 * and there is 919 slot numbers context information per transaction.
1155 	 *
1156 	 * 72 transaction blocks amounts to more than 2**16 context slots,
1157 	 * so cap there first.
1158 	 */
1159 	const unsigned int max_al_nr = DRBD_AL_EXTENTS_MAX;
1160 	const unsigned int sufficient_on_disk =
1161 		(max_al_nr + AL_CONTEXT_PER_TRANSACTION -1)
1162 		/AL_CONTEXT_PER_TRANSACTION;
1163 
1164 	unsigned int al_size_4k = bdev->md.al_size_4k;
1165 
1166 	if (al_size_4k > sufficient_on_disk)
1167 		return max_al_nr;
1168 
1169 	return (al_size_4k - 1) * AL_CONTEXT_PER_TRANSACTION;
1170 }
1171 
1172 int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
1173 {
1174 	enum drbd_ret_code retcode;
1175 	struct drbd_conf *mdev;
1176 	struct disk_conf *new_disk_conf, *old_disk_conf;
1177 	struct fifo_buffer *old_plan = NULL, *new_plan = NULL;
1178 	int err, fifo_size;
1179 
1180 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
1181 	if (!adm_ctx.reply_skb)
1182 		return retcode;
1183 	if (retcode != NO_ERROR)
1184 		goto out;
1185 
1186 	mdev = adm_ctx.mdev;
1187 
1188 	/* we also need a disk
1189 	 * to change the options on */
1190 	if (!get_ldev(mdev)) {
1191 		retcode = ERR_NO_DISK;
1192 		goto out;
1193 	}
1194 
1195 	new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
1196 	if (!new_disk_conf) {
1197 		retcode = ERR_NOMEM;
1198 		goto fail;
1199 	}
1200 
1201 	mutex_lock(&mdev->tconn->conf_update);
1202 	old_disk_conf = mdev->ldev->disk_conf;
1203 	*new_disk_conf = *old_disk_conf;
1204 	if (should_set_defaults(info))
1205 		set_disk_conf_defaults(new_disk_conf);
1206 
1207 	err = disk_conf_from_attrs_for_change(new_disk_conf, info);
1208 	if (err && err != -ENOMSG) {
1209 		retcode = ERR_MANDATORY_TAG;
1210 		drbd_msg_put_info(from_attrs_err_to_txt(err));
1211 	}
1212 
1213 	if (!expect(new_disk_conf->resync_rate >= 1))
1214 		new_disk_conf->resync_rate = 1;
1215 
1216 	if (new_disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
1217 		new_disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
1218 	if (new_disk_conf->al_extents > drbd_al_extents_max(mdev->ldev))
1219 		new_disk_conf->al_extents = drbd_al_extents_max(mdev->ldev);
1220 
1221 	if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
1222 		new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
1223 
1224 	fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ;
1225 	if (fifo_size != mdev->rs_plan_s->size) {
1226 		new_plan = fifo_alloc(fifo_size);
1227 		if (!new_plan) {
1228 			dev_err(DEV, "kmalloc of fifo_buffer failed");
1229 			retcode = ERR_NOMEM;
1230 			goto fail_unlock;
1231 		}
1232 	}
1233 
1234 	drbd_suspend_io(mdev);
1235 	wait_event(mdev->al_wait, lc_try_lock(mdev->act_log));
1236 	drbd_al_shrink(mdev);
1237 	err = drbd_check_al_size(mdev, new_disk_conf);
1238 	lc_unlock(mdev->act_log);
1239 	wake_up(&mdev->al_wait);
1240 	drbd_resume_io(mdev);
1241 
1242 	if (err) {
1243 		retcode = ERR_NOMEM;
1244 		goto fail_unlock;
1245 	}
1246 
1247 	write_lock_irq(&global_state_lock);
1248 	retcode = drbd_resync_after_valid(mdev, new_disk_conf->resync_after);
1249 	if (retcode == NO_ERROR) {
1250 		rcu_assign_pointer(mdev->ldev->disk_conf, new_disk_conf);
1251 		drbd_resync_after_changed(mdev);
1252 	}
1253 	write_unlock_irq(&global_state_lock);
1254 
1255 	if (retcode != NO_ERROR)
1256 		goto fail_unlock;
1257 
1258 	if (new_plan) {
1259 		old_plan = mdev->rs_plan_s;
1260 		rcu_assign_pointer(mdev->rs_plan_s, new_plan);
1261 	}
1262 
1263 	mutex_unlock(&mdev->tconn->conf_update);
1264 
1265 	if (new_disk_conf->al_updates)
1266 		mdev->ldev->md.flags &= ~MDF_AL_DISABLED;
1267 	else
1268 		mdev->ldev->md.flags |= MDF_AL_DISABLED;
1269 
1270 	if (new_disk_conf->md_flushes)
1271 		clear_bit(MD_NO_FUA, &mdev->flags);
1272 	else
1273 		set_bit(MD_NO_FUA, &mdev->flags);
1274 
1275 	drbd_bump_write_ordering(mdev->tconn, WO_bdev_flush);
1276 
1277 	drbd_md_sync(mdev);
1278 
1279 	if (mdev->state.conn >= C_CONNECTED)
1280 		drbd_send_sync_param(mdev);
1281 
1282 	synchronize_rcu();
1283 	kfree(old_disk_conf);
1284 	kfree(old_plan);
1285 	mod_timer(&mdev->request_timer, jiffies + HZ);
1286 	goto success;
1287 
1288 fail_unlock:
1289 	mutex_unlock(&mdev->tconn->conf_update);
1290  fail:
1291 	kfree(new_disk_conf);
1292 	kfree(new_plan);
1293 success:
1294 	put_ldev(mdev);
1295  out:
1296 	drbd_adm_finish(info, retcode);
1297 	return 0;
1298 }
1299 
1300 int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
1301 {
1302 	struct drbd_conf *mdev;
1303 	int err;
1304 	enum drbd_ret_code retcode;
1305 	enum determine_dev_size dd;
1306 	sector_t max_possible_sectors;
1307 	sector_t min_md_device_sectors;
1308 	struct drbd_backing_dev *nbc = NULL; /* new_backing_conf */
1309 	struct disk_conf *new_disk_conf = NULL;
1310 	struct block_device *bdev;
1311 	struct lru_cache *resync_lru = NULL;
1312 	struct fifo_buffer *new_plan = NULL;
1313 	union drbd_state ns, os;
1314 	enum drbd_state_rv rv;
1315 	struct net_conf *nc;
1316 
1317 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
1318 	if (!adm_ctx.reply_skb)
1319 		return retcode;
1320 	if (retcode != NO_ERROR)
1321 		goto finish;
1322 
1323 	mdev = adm_ctx.mdev;
1324 	conn_reconfig_start(mdev->tconn);
1325 
1326 	/* if you want to reconfigure, please tear down first */
1327 	if (mdev->state.disk > D_DISKLESS) {
1328 		retcode = ERR_DISK_CONFIGURED;
1329 		goto fail;
1330 	}
1331 	/* It may just now have detached because of IO error.  Make sure
1332 	 * drbd_ldev_destroy is done already, we may end up here very fast,
1333 	 * e.g. if someone calls attach from the on-io-error handler,
1334 	 * to realize a "hot spare" feature (not that I'd recommend that) */
1335 	wait_event(mdev->misc_wait, !atomic_read(&mdev->local_cnt));
1336 
1337 	/* make sure there is no leftover from previous force-detach attempts */
1338 	clear_bit(FORCE_DETACH, &mdev->flags);
1339 	clear_bit(WAS_IO_ERROR, &mdev->flags);
1340 	clear_bit(WAS_READ_ERROR, &mdev->flags);
1341 
1342 	/* and no leftover from previously aborted resync or verify, either */
1343 	mdev->rs_total = 0;
1344 	mdev->rs_failed = 0;
1345 	atomic_set(&mdev->rs_pending_cnt, 0);
1346 
1347 	/* allocation not in the IO path, drbdsetup context */
1348 	nbc = kzalloc(sizeof(struct drbd_backing_dev), GFP_KERNEL);
1349 	if (!nbc) {
1350 		retcode = ERR_NOMEM;
1351 		goto fail;
1352 	}
1353 	spin_lock_init(&nbc->md.uuid_lock);
1354 
1355 	new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
1356 	if (!new_disk_conf) {
1357 		retcode = ERR_NOMEM;
1358 		goto fail;
1359 	}
1360 	nbc->disk_conf = new_disk_conf;
1361 
1362 	set_disk_conf_defaults(new_disk_conf);
1363 	err = disk_conf_from_attrs(new_disk_conf, info);
1364 	if (err) {
1365 		retcode = ERR_MANDATORY_TAG;
1366 		drbd_msg_put_info(from_attrs_err_to_txt(err));
1367 		goto fail;
1368 	}
1369 
1370 	if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
1371 		new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
1372 
1373 	new_plan = fifo_alloc((new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ);
1374 	if (!new_plan) {
1375 		retcode = ERR_NOMEM;
1376 		goto fail;
1377 	}
1378 
1379 	if (new_disk_conf->meta_dev_idx < DRBD_MD_INDEX_FLEX_INT) {
1380 		retcode = ERR_MD_IDX_INVALID;
1381 		goto fail;
1382 	}
1383 
1384 	write_lock_irq(&global_state_lock);
1385 	retcode = drbd_resync_after_valid(mdev, new_disk_conf->resync_after);
1386 	write_unlock_irq(&global_state_lock);
1387 	if (retcode != NO_ERROR)
1388 		goto fail;
1389 
1390 	rcu_read_lock();
1391 	nc = rcu_dereference(mdev->tconn->net_conf);
1392 	if (nc) {
1393 		if (new_disk_conf->fencing == FP_STONITH && nc->wire_protocol == DRBD_PROT_A) {
1394 			rcu_read_unlock();
1395 			retcode = ERR_STONITH_AND_PROT_A;
1396 			goto fail;
1397 		}
1398 	}
1399 	rcu_read_unlock();
1400 
1401 	bdev = blkdev_get_by_path(new_disk_conf->backing_dev,
1402 				  FMODE_READ | FMODE_WRITE | FMODE_EXCL, mdev);
1403 	if (IS_ERR(bdev)) {
1404 		dev_err(DEV, "open(\"%s\") failed with %ld\n", new_disk_conf->backing_dev,
1405 			PTR_ERR(bdev));
1406 		retcode = ERR_OPEN_DISK;
1407 		goto fail;
1408 	}
1409 	nbc->backing_bdev = bdev;
1410 
1411 	/*
1412 	 * meta_dev_idx >= 0: external fixed size, possibly multiple
1413 	 * drbd sharing one meta device.  TODO in that case, paranoia
1414 	 * check that [md_bdev, meta_dev_idx] is not yet used by some
1415 	 * other drbd minor!  (if you use drbd.conf + drbdadm, that
1416 	 * should check it for you already; but if you don't, or
1417 	 * someone fooled it, we need to double check here)
1418 	 */
1419 	bdev = blkdev_get_by_path(new_disk_conf->meta_dev,
1420 				  FMODE_READ | FMODE_WRITE | FMODE_EXCL,
1421 				  (new_disk_conf->meta_dev_idx < 0) ?
1422 				  (void *)mdev : (void *)drbd_m_holder);
1423 	if (IS_ERR(bdev)) {
1424 		dev_err(DEV, "open(\"%s\") failed with %ld\n", new_disk_conf->meta_dev,
1425 			PTR_ERR(bdev));
1426 		retcode = ERR_OPEN_MD_DISK;
1427 		goto fail;
1428 	}
1429 	nbc->md_bdev = bdev;
1430 
1431 	if ((nbc->backing_bdev == nbc->md_bdev) !=
1432 	    (new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
1433 	     new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)) {
1434 		retcode = ERR_MD_IDX_INVALID;
1435 		goto fail;
1436 	}
1437 
1438 	resync_lru = lc_create("resync", drbd_bm_ext_cache,
1439 			1, 61, sizeof(struct bm_extent),
1440 			offsetof(struct bm_extent, lce));
1441 	if (!resync_lru) {
1442 		retcode = ERR_NOMEM;
1443 		goto fail;
1444 	}
1445 
1446 	/* Read our meta data super block early.
1447 	 * This also sets other on-disk offsets. */
1448 	retcode = drbd_md_read(mdev, nbc);
1449 	if (retcode != NO_ERROR)
1450 		goto fail;
1451 
1452 	if (new_disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
1453 		new_disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
1454 	if (new_disk_conf->al_extents > drbd_al_extents_max(nbc))
1455 		new_disk_conf->al_extents = drbd_al_extents_max(nbc);
1456 
1457 	if (drbd_get_max_capacity(nbc) < new_disk_conf->disk_size) {
1458 		dev_err(DEV, "max capacity %llu smaller than disk size %llu\n",
1459 			(unsigned long long) drbd_get_max_capacity(nbc),
1460 			(unsigned long long) new_disk_conf->disk_size);
1461 		retcode = ERR_DISK_TOO_SMALL;
1462 		goto fail;
1463 	}
1464 
1465 	if (new_disk_conf->meta_dev_idx < 0) {
1466 		max_possible_sectors = DRBD_MAX_SECTORS_FLEX;
1467 		/* at least one MB, otherwise it does not make sense */
1468 		min_md_device_sectors = (2<<10);
1469 	} else {
1470 		max_possible_sectors = DRBD_MAX_SECTORS;
1471 		min_md_device_sectors = MD_128MB_SECT * (new_disk_conf->meta_dev_idx + 1);
1472 	}
1473 
1474 	if (drbd_get_capacity(nbc->md_bdev) < min_md_device_sectors) {
1475 		retcode = ERR_MD_DISK_TOO_SMALL;
1476 		dev_warn(DEV, "refusing attach: md-device too small, "
1477 		     "at least %llu sectors needed for this meta-disk type\n",
1478 		     (unsigned long long) min_md_device_sectors);
1479 		goto fail;
1480 	}
1481 
1482 	/* Make sure the new disk is big enough
1483 	 * (we may currently be R_PRIMARY with no local disk...) */
1484 	if (drbd_get_max_capacity(nbc) <
1485 	    drbd_get_capacity(mdev->this_bdev)) {
1486 		retcode = ERR_DISK_TOO_SMALL;
1487 		goto fail;
1488 	}
1489 
1490 	nbc->known_size = drbd_get_capacity(nbc->backing_bdev);
1491 
1492 	if (nbc->known_size > max_possible_sectors) {
1493 		dev_warn(DEV, "==> truncating very big lower level device "
1494 			"to currently maximum possible %llu sectors <==\n",
1495 			(unsigned long long) max_possible_sectors);
1496 		if (new_disk_conf->meta_dev_idx >= 0)
1497 			dev_warn(DEV, "==>> using internal or flexible "
1498 				      "meta data may help <<==\n");
1499 	}
1500 
1501 	drbd_suspend_io(mdev);
1502 	/* also wait for the last barrier ack. */
1503 	/* FIXME see also https://daiquiri.linbit/cgi-bin/bugzilla/show_bug.cgi?id=171
1504 	 * We need a way to either ignore barrier acks for barriers sent before a device
1505 	 * was attached, or a way to wait for all pending barrier acks to come in.
1506 	 * As barriers are counted per resource,
1507 	 * we'd need to suspend io on all devices of a resource.
1508 	 */
1509 	wait_event(mdev->misc_wait, !atomic_read(&mdev->ap_pending_cnt) || drbd_suspended(mdev));
1510 	/* and for any other previously queued work */
1511 	drbd_flush_workqueue(mdev);
1512 
1513 	rv = _drbd_request_state(mdev, NS(disk, D_ATTACHING), CS_VERBOSE);
1514 	retcode = rv;  /* FIXME: Type mismatch. */
1515 	drbd_resume_io(mdev);
1516 	if (rv < SS_SUCCESS)
1517 		goto fail;
1518 
1519 	if (!get_ldev_if_state(mdev, D_ATTACHING))
1520 		goto force_diskless;
1521 
1522 	if (!mdev->bitmap) {
1523 		if (drbd_bm_init(mdev)) {
1524 			retcode = ERR_NOMEM;
1525 			goto force_diskless_dec;
1526 		}
1527 	}
1528 
1529 	if (mdev->state.conn < C_CONNECTED &&
1530 	    mdev->state.role == R_PRIMARY &&
1531 	    (mdev->ed_uuid & ~((u64)1)) != (nbc->md.uuid[UI_CURRENT] & ~((u64)1))) {
1532 		dev_err(DEV, "Can only attach to data with current UUID=%016llX\n",
1533 		    (unsigned long long)mdev->ed_uuid);
1534 		retcode = ERR_DATA_NOT_CURRENT;
1535 		goto force_diskless_dec;
1536 	}
1537 
1538 	/* Since we are diskless, fix the activity log first... */
1539 	if (drbd_check_al_size(mdev, new_disk_conf)) {
1540 		retcode = ERR_NOMEM;
1541 		goto force_diskless_dec;
1542 	}
1543 
1544 	/* Prevent shrinking of consistent devices ! */
1545 	if (drbd_md_test_flag(nbc, MDF_CONSISTENT) &&
1546 	    drbd_new_dev_size(mdev, nbc, nbc->disk_conf->disk_size, 0) < nbc->md.la_size_sect) {
1547 		dev_warn(DEV, "refusing to truncate a consistent device\n");
1548 		retcode = ERR_DISK_TOO_SMALL;
1549 		goto force_diskless_dec;
1550 	}
1551 
1552 	/* Reset the "barriers don't work" bits here, then force meta data to
1553 	 * be written, to ensure we determine if barriers are supported. */
1554 	if (new_disk_conf->md_flushes)
1555 		clear_bit(MD_NO_FUA, &mdev->flags);
1556 	else
1557 		set_bit(MD_NO_FUA, &mdev->flags);
1558 
1559 	/* Point of no return reached.
1560 	 * Devices and memory are no longer released by error cleanup below.
1561 	 * now mdev takes over responsibility, and the state engine should
1562 	 * clean it up somewhere.  */
1563 	D_ASSERT(mdev->ldev == NULL);
1564 	mdev->ldev = nbc;
1565 	mdev->resync = resync_lru;
1566 	mdev->rs_plan_s = new_plan;
1567 	nbc = NULL;
1568 	resync_lru = NULL;
1569 	new_disk_conf = NULL;
1570 	new_plan = NULL;
1571 
1572 	drbd_bump_write_ordering(mdev->tconn, WO_bdev_flush);
1573 
1574 	if (drbd_md_test_flag(mdev->ldev, MDF_CRASHED_PRIMARY))
1575 		set_bit(CRASHED_PRIMARY, &mdev->flags);
1576 	else
1577 		clear_bit(CRASHED_PRIMARY, &mdev->flags);
1578 
1579 	if (drbd_md_test_flag(mdev->ldev, MDF_PRIMARY_IND) &&
1580 	    !(mdev->state.role == R_PRIMARY && mdev->tconn->susp_nod))
1581 		set_bit(CRASHED_PRIMARY, &mdev->flags);
1582 
1583 	mdev->send_cnt = 0;
1584 	mdev->recv_cnt = 0;
1585 	mdev->read_cnt = 0;
1586 	mdev->writ_cnt = 0;
1587 
1588 	drbd_reconsider_max_bio_size(mdev);
1589 
1590 	/* If I am currently not R_PRIMARY,
1591 	 * but meta data primary indicator is set,
1592 	 * I just now recover from a hard crash,
1593 	 * and have been R_PRIMARY before that crash.
1594 	 *
1595 	 * Now, if I had no connection before that crash
1596 	 * (have been degraded R_PRIMARY), chances are that
1597 	 * I won't find my peer now either.
1598 	 *
1599 	 * In that case, and _only_ in that case,
1600 	 * we use the degr-wfc-timeout instead of the default,
1601 	 * so we can automatically recover from a crash of a
1602 	 * degraded but active "cluster" after a certain timeout.
1603 	 */
1604 	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
1605 	if (mdev->state.role != R_PRIMARY &&
1606 	     drbd_md_test_flag(mdev->ldev, MDF_PRIMARY_IND) &&
1607 	    !drbd_md_test_flag(mdev->ldev, MDF_CONNECTED_IND))
1608 		set_bit(USE_DEGR_WFC_T, &mdev->flags);
1609 
1610 	dd = drbd_determine_dev_size(mdev, 0);
1611 	if (dd == dev_size_error) {
1612 		retcode = ERR_NOMEM_BITMAP;
1613 		goto force_diskless_dec;
1614 	} else if (dd == grew)
1615 		set_bit(RESYNC_AFTER_NEG, &mdev->flags);
1616 
1617 	if (drbd_md_test_flag(mdev->ldev, MDF_FULL_SYNC) ||
1618 	    (test_bit(CRASHED_PRIMARY, &mdev->flags) &&
1619 	     drbd_md_test_flag(mdev->ldev, MDF_AL_DISABLED))) {
1620 		dev_info(DEV, "Assuming that all blocks are out of sync "
1621 		     "(aka FullSync)\n");
1622 		if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write,
1623 			"set_n_write from attaching", BM_LOCKED_MASK)) {
1624 			retcode = ERR_IO_MD_DISK;
1625 			goto force_diskless_dec;
1626 		}
1627 	} else {
1628 		if (drbd_bitmap_io(mdev, &drbd_bm_read,
1629 			"read from attaching", BM_LOCKED_MASK)) {
1630 			retcode = ERR_IO_MD_DISK;
1631 			goto force_diskless_dec;
1632 		}
1633 	}
1634 
1635 	if (_drbd_bm_total_weight(mdev) == drbd_bm_bits(mdev))
1636 		drbd_suspend_al(mdev); /* IO is still suspended here... */
1637 
1638 	spin_lock_irq(&mdev->tconn->req_lock);
1639 	os = drbd_read_state(mdev);
1640 	ns = os;
1641 	/* If MDF_CONSISTENT is not set go into inconsistent state,
1642 	   otherwise investigate MDF_WasUpToDate...
1643 	   If MDF_WAS_UP_TO_DATE is not set go into D_OUTDATED disk state,
1644 	   otherwise into D_CONSISTENT state.
1645 	*/
1646 	if (drbd_md_test_flag(mdev->ldev, MDF_CONSISTENT)) {
1647 		if (drbd_md_test_flag(mdev->ldev, MDF_WAS_UP_TO_DATE))
1648 			ns.disk = D_CONSISTENT;
1649 		else
1650 			ns.disk = D_OUTDATED;
1651 	} else {
1652 		ns.disk = D_INCONSISTENT;
1653 	}
1654 
1655 	if (drbd_md_test_flag(mdev->ldev, MDF_PEER_OUT_DATED))
1656 		ns.pdsk = D_OUTDATED;
1657 
1658 	rcu_read_lock();
1659 	if (ns.disk == D_CONSISTENT &&
1660 	    (ns.pdsk == D_OUTDATED || rcu_dereference(mdev->ldev->disk_conf)->fencing == FP_DONT_CARE))
1661 		ns.disk = D_UP_TO_DATE;
1662 
1663 	/* All tests on MDF_PRIMARY_IND, MDF_CONNECTED_IND,
1664 	   MDF_CONSISTENT and MDF_WAS_UP_TO_DATE must happen before
1665 	   this point, because drbd_request_state() modifies these
1666 	   flags. */
1667 
1668 	if (rcu_dereference(mdev->ldev->disk_conf)->al_updates)
1669 		mdev->ldev->md.flags &= ~MDF_AL_DISABLED;
1670 	else
1671 		mdev->ldev->md.flags |= MDF_AL_DISABLED;
1672 
1673 	rcu_read_unlock();
1674 
1675 	/* In case we are C_CONNECTED postpone any decision on the new disk
1676 	   state after the negotiation phase. */
1677 	if (mdev->state.conn == C_CONNECTED) {
1678 		mdev->new_state_tmp.i = ns.i;
1679 		ns.i = os.i;
1680 		ns.disk = D_NEGOTIATING;
1681 
1682 		/* We expect to receive up-to-date UUIDs soon.
1683 		   To avoid a race in receive_state, free p_uuid while
1684 		   holding req_lock. I.e. atomic with the state change */
1685 		kfree(mdev->p_uuid);
1686 		mdev->p_uuid = NULL;
1687 	}
1688 
1689 	rv = _drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
1690 	spin_unlock_irq(&mdev->tconn->req_lock);
1691 
1692 	if (rv < SS_SUCCESS)
1693 		goto force_diskless_dec;
1694 
1695 	mod_timer(&mdev->request_timer, jiffies + HZ);
1696 
1697 	if (mdev->state.role == R_PRIMARY)
1698 		mdev->ldev->md.uuid[UI_CURRENT] |=  (u64)1;
1699 	else
1700 		mdev->ldev->md.uuid[UI_CURRENT] &= ~(u64)1;
1701 
1702 	drbd_md_mark_dirty(mdev);
1703 	drbd_md_sync(mdev);
1704 
1705 	kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
1706 	put_ldev(mdev);
1707 	conn_reconfig_done(mdev->tconn);
1708 	drbd_adm_finish(info, retcode);
1709 	return 0;
1710 
1711  force_diskless_dec:
1712 	put_ldev(mdev);
1713  force_diskless:
1714 	drbd_force_state(mdev, NS(disk, D_DISKLESS));
1715 	drbd_md_sync(mdev);
1716  fail:
1717 	conn_reconfig_done(mdev->tconn);
1718 	if (nbc) {
1719 		if (nbc->backing_bdev)
1720 			blkdev_put(nbc->backing_bdev,
1721 				   FMODE_READ | FMODE_WRITE | FMODE_EXCL);
1722 		if (nbc->md_bdev)
1723 			blkdev_put(nbc->md_bdev,
1724 				   FMODE_READ | FMODE_WRITE | FMODE_EXCL);
1725 		kfree(nbc);
1726 	}
1727 	kfree(new_disk_conf);
1728 	lc_destroy(resync_lru);
1729 	kfree(new_plan);
1730 
1731  finish:
1732 	drbd_adm_finish(info, retcode);
1733 	return 0;
1734 }
1735 
1736 static int adm_detach(struct drbd_conf *mdev, int force)
1737 {
1738 	enum drbd_state_rv retcode;
1739 	int ret;
1740 
1741 	if (force) {
1742 		set_bit(FORCE_DETACH, &mdev->flags);
1743 		drbd_force_state(mdev, NS(disk, D_FAILED));
1744 		retcode = SS_SUCCESS;
1745 		goto out;
1746 	}
1747 
1748 	drbd_suspend_io(mdev); /* so no-one is stuck in drbd_al_begin_io */
1749 	drbd_md_get_buffer(mdev); /* make sure there is no in-flight meta-data IO */
1750 	retcode = drbd_request_state(mdev, NS(disk, D_FAILED));
1751 	drbd_md_put_buffer(mdev);
1752 	/* D_FAILED will transition to DISKLESS. */
1753 	ret = wait_event_interruptible(mdev->misc_wait,
1754 			mdev->state.disk != D_FAILED);
1755 	drbd_resume_io(mdev);
1756 	if ((int)retcode == (int)SS_IS_DISKLESS)
1757 		retcode = SS_NOTHING_TO_DO;
1758 	if (ret)
1759 		retcode = ERR_INTR;
1760 out:
1761 	return retcode;
1762 }
1763 
1764 /* Detaching the disk is a process in multiple stages.  First we need to lock
1765  * out application IO, in-flight IO, IO stuck in drbd_al_begin_io.
1766  * Then we transition to D_DISKLESS, and wait for put_ldev() to return all
1767  * internal references as well.
1768  * Only then we have finally detached. */
1769 int drbd_adm_detach(struct sk_buff *skb, struct genl_info *info)
1770 {
1771 	enum drbd_ret_code retcode;
1772 	struct detach_parms parms = { };
1773 	int err;
1774 
1775 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
1776 	if (!adm_ctx.reply_skb)
1777 		return retcode;
1778 	if (retcode != NO_ERROR)
1779 		goto out;
1780 
1781 	if (info->attrs[DRBD_NLA_DETACH_PARMS]) {
1782 		err = detach_parms_from_attrs(&parms, info);
1783 		if (err) {
1784 			retcode = ERR_MANDATORY_TAG;
1785 			drbd_msg_put_info(from_attrs_err_to_txt(err));
1786 			goto out;
1787 		}
1788 	}
1789 
1790 	retcode = adm_detach(adm_ctx.mdev, parms.force_detach);
1791 out:
1792 	drbd_adm_finish(info, retcode);
1793 	return 0;
1794 }
1795 
1796 static bool conn_resync_running(struct drbd_tconn *tconn)
1797 {
1798 	struct drbd_conf *mdev;
1799 	bool rv = false;
1800 	int vnr;
1801 
1802 	rcu_read_lock();
1803 	idr_for_each_entry(&tconn->volumes, mdev, vnr) {
1804 		if (mdev->state.conn == C_SYNC_SOURCE ||
1805 		    mdev->state.conn == C_SYNC_TARGET ||
1806 		    mdev->state.conn == C_PAUSED_SYNC_S ||
1807 		    mdev->state.conn == C_PAUSED_SYNC_T) {
1808 			rv = true;
1809 			break;
1810 		}
1811 	}
1812 	rcu_read_unlock();
1813 
1814 	return rv;
1815 }
1816 
1817 static bool conn_ov_running(struct drbd_tconn *tconn)
1818 {
1819 	struct drbd_conf *mdev;
1820 	bool rv = false;
1821 	int vnr;
1822 
1823 	rcu_read_lock();
1824 	idr_for_each_entry(&tconn->volumes, mdev, vnr) {
1825 		if (mdev->state.conn == C_VERIFY_S ||
1826 		    mdev->state.conn == C_VERIFY_T) {
1827 			rv = true;
1828 			break;
1829 		}
1830 	}
1831 	rcu_read_unlock();
1832 
1833 	return rv;
1834 }
1835 
1836 static enum drbd_ret_code
1837 _check_net_options(struct drbd_tconn *tconn, struct net_conf *old_conf, struct net_conf *new_conf)
1838 {
1839 	struct drbd_conf *mdev;
1840 	int i;
1841 
1842 	if (old_conf && tconn->cstate == C_WF_REPORT_PARAMS && tconn->agreed_pro_version < 100) {
1843 		if (new_conf->wire_protocol != old_conf->wire_protocol)
1844 			return ERR_NEED_APV_100;
1845 
1846 		if (new_conf->two_primaries != old_conf->two_primaries)
1847 			return ERR_NEED_APV_100;
1848 
1849 		if (strcmp(new_conf->integrity_alg, old_conf->integrity_alg))
1850 			return ERR_NEED_APV_100;
1851 	}
1852 
1853 	if (!new_conf->two_primaries &&
1854 	    conn_highest_role(tconn) == R_PRIMARY &&
1855 	    conn_highest_peer(tconn) == R_PRIMARY)
1856 		return ERR_NEED_ALLOW_TWO_PRI;
1857 
1858 	if (new_conf->two_primaries &&
1859 	    (new_conf->wire_protocol != DRBD_PROT_C))
1860 		return ERR_NOT_PROTO_C;
1861 
1862 	idr_for_each_entry(&tconn->volumes, mdev, i) {
1863 		if (get_ldev(mdev)) {
1864 			enum drbd_fencing_p fp = rcu_dereference(mdev->ldev->disk_conf)->fencing;
1865 			put_ldev(mdev);
1866 			if (new_conf->wire_protocol == DRBD_PROT_A && fp == FP_STONITH)
1867 				return ERR_STONITH_AND_PROT_A;
1868 		}
1869 		if (mdev->state.role == R_PRIMARY && new_conf->discard_my_data)
1870 			return ERR_DISCARD_IMPOSSIBLE;
1871 	}
1872 
1873 	if (new_conf->on_congestion != OC_BLOCK && new_conf->wire_protocol != DRBD_PROT_A)
1874 		return ERR_CONG_NOT_PROTO_A;
1875 
1876 	return NO_ERROR;
1877 }
1878 
1879 static enum drbd_ret_code
1880 check_net_options(struct drbd_tconn *tconn, struct net_conf *new_conf)
1881 {
1882 	static enum drbd_ret_code rv;
1883 	struct drbd_conf *mdev;
1884 	int i;
1885 
1886 	rcu_read_lock();
1887 	rv = _check_net_options(tconn, rcu_dereference(tconn->net_conf), new_conf);
1888 	rcu_read_unlock();
1889 
1890 	/* tconn->volumes protected by genl_lock() here */
1891 	idr_for_each_entry(&tconn->volumes, mdev, i) {
1892 		if (!mdev->bitmap) {
1893 			if(drbd_bm_init(mdev))
1894 				return ERR_NOMEM;
1895 		}
1896 	}
1897 
1898 	return rv;
1899 }
1900 
1901 struct crypto {
1902 	struct crypto_hash *verify_tfm;
1903 	struct crypto_hash *csums_tfm;
1904 	struct crypto_hash *cram_hmac_tfm;
1905 	struct crypto_hash *integrity_tfm;
1906 };
1907 
1908 static int
1909 alloc_hash(struct crypto_hash **tfm, char *tfm_name, int err_alg)
1910 {
1911 	if (!tfm_name[0])
1912 		return NO_ERROR;
1913 
1914 	*tfm = crypto_alloc_hash(tfm_name, 0, CRYPTO_ALG_ASYNC);
1915 	if (IS_ERR(*tfm)) {
1916 		*tfm = NULL;
1917 		return err_alg;
1918 	}
1919 
1920 	return NO_ERROR;
1921 }
1922 
1923 static enum drbd_ret_code
1924 alloc_crypto(struct crypto *crypto, struct net_conf *new_conf)
1925 {
1926 	char hmac_name[CRYPTO_MAX_ALG_NAME];
1927 	enum drbd_ret_code rv;
1928 
1929 	rv = alloc_hash(&crypto->csums_tfm, new_conf->csums_alg,
1930 		       ERR_CSUMS_ALG);
1931 	if (rv != NO_ERROR)
1932 		return rv;
1933 	rv = alloc_hash(&crypto->verify_tfm, new_conf->verify_alg,
1934 		       ERR_VERIFY_ALG);
1935 	if (rv != NO_ERROR)
1936 		return rv;
1937 	rv = alloc_hash(&crypto->integrity_tfm, new_conf->integrity_alg,
1938 		       ERR_INTEGRITY_ALG);
1939 	if (rv != NO_ERROR)
1940 		return rv;
1941 	if (new_conf->cram_hmac_alg[0] != 0) {
1942 		snprintf(hmac_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)",
1943 			 new_conf->cram_hmac_alg);
1944 
1945 		rv = alloc_hash(&crypto->cram_hmac_tfm, hmac_name,
1946 			       ERR_AUTH_ALG);
1947 	}
1948 
1949 	return rv;
1950 }
1951 
1952 static void free_crypto(struct crypto *crypto)
1953 {
1954 	crypto_free_hash(crypto->cram_hmac_tfm);
1955 	crypto_free_hash(crypto->integrity_tfm);
1956 	crypto_free_hash(crypto->csums_tfm);
1957 	crypto_free_hash(crypto->verify_tfm);
1958 }
1959 
1960 int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
1961 {
1962 	enum drbd_ret_code retcode;
1963 	struct drbd_tconn *tconn;
1964 	struct net_conf *old_conf, *new_conf = NULL;
1965 	int err;
1966 	int ovr; /* online verify running */
1967 	int rsr; /* re-sync running */
1968 	struct crypto crypto = { };
1969 
1970 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_CONNECTION);
1971 	if (!adm_ctx.reply_skb)
1972 		return retcode;
1973 	if (retcode != NO_ERROR)
1974 		goto out;
1975 
1976 	tconn = adm_ctx.tconn;
1977 
1978 	new_conf = kzalloc(sizeof(struct net_conf), GFP_KERNEL);
1979 	if (!new_conf) {
1980 		retcode = ERR_NOMEM;
1981 		goto out;
1982 	}
1983 
1984 	conn_reconfig_start(tconn);
1985 
1986 	mutex_lock(&tconn->data.mutex);
1987 	mutex_lock(&tconn->conf_update);
1988 	old_conf = tconn->net_conf;
1989 
1990 	if (!old_conf) {
1991 		drbd_msg_put_info("net conf missing, try connect");
1992 		retcode = ERR_INVALID_REQUEST;
1993 		goto fail;
1994 	}
1995 
1996 	*new_conf = *old_conf;
1997 	if (should_set_defaults(info))
1998 		set_net_conf_defaults(new_conf);
1999 
2000 	err = net_conf_from_attrs_for_change(new_conf, info);
2001 	if (err && err != -ENOMSG) {
2002 		retcode = ERR_MANDATORY_TAG;
2003 		drbd_msg_put_info(from_attrs_err_to_txt(err));
2004 		goto fail;
2005 	}
2006 
2007 	retcode = check_net_options(tconn, new_conf);
2008 	if (retcode != NO_ERROR)
2009 		goto fail;
2010 
2011 	/* re-sync running */
2012 	rsr = conn_resync_running(tconn);
2013 	if (rsr && strcmp(new_conf->csums_alg, old_conf->csums_alg)) {
2014 		retcode = ERR_CSUMS_RESYNC_RUNNING;
2015 		goto fail;
2016 	}
2017 
2018 	/* online verify running */
2019 	ovr = conn_ov_running(tconn);
2020 	if (ovr && strcmp(new_conf->verify_alg, old_conf->verify_alg)) {
2021 		retcode = ERR_VERIFY_RUNNING;
2022 		goto fail;
2023 	}
2024 
2025 	retcode = alloc_crypto(&crypto, new_conf);
2026 	if (retcode != NO_ERROR)
2027 		goto fail;
2028 
2029 	rcu_assign_pointer(tconn->net_conf, new_conf);
2030 
2031 	if (!rsr) {
2032 		crypto_free_hash(tconn->csums_tfm);
2033 		tconn->csums_tfm = crypto.csums_tfm;
2034 		crypto.csums_tfm = NULL;
2035 	}
2036 	if (!ovr) {
2037 		crypto_free_hash(tconn->verify_tfm);
2038 		tconn->verify_tfm = crypto.verify_tfm;
2039 		crypto.verify_tfm = NULL;
2040 	}
2041 
2042 	crypto_free_hash(tconn->integrity_tfm);
2043 	tconn->integrity_tfm = crypto.integrity_tfm;
2044 	if (tconn->cstate >= C_WF_REPORT_PARAMS && tconn->agreed_pro_version >= 100)
2045 		/* Do this without trying to take tconn->data.mutex again.  */
2046 		__drbd_send_protocol(tconn, P_PROTOCOL_UPDATE);
2047 
2048 	crypto_free_hash(tconn->cram_hmac_tfm);
2049 	tconn->cram_hmac_tfm = crypto.cram_hmac_tfm;
2050 
2051 	mutex_unlock(&tconn->conf_update);
2052 	mutex_unlock(&tconn->data.mutex);
2053 	synchronize_rcu();
2054 	kfree(old_conf);
2055 
2056 	if (tconn->cstate >= C_WF_REPORT_PARAMS)
2057 		drbd_send_sync_param(minor_to_mdev(conn_lowest_minor(tconn)));
2058 
2059 	goto done;
2060 
2061  fail:
2062 	mutex_unlock(&tconn->conf_update);
2063 	mutex_unlock(&tconn->data.mutex);
2064 	free_crypto(&crypto);
2065 	kfree(new_conf);
2066  done:
2067 	conn_reconfig_done(tconn);
2068  out:
2069 	drbd_adm_finish(info, retcode);
2070 	return 0;
2071 }
2072 
2073 int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
2074 {
2075 	struct drbd_conf *mdev;
2076 	struct net_conf *old_conf, *new_conf = NULL;
2077 	struct crypto crypto = { };
2078 	struct drbd_tconn *tconn;
2079 	enum drbd_ret_code retcode;
2080 	int i;
2081 	int err;
2082 
2083 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_RESOURCE);
2084 
2085 	if (!adm_ctx.reply_skb)
2086 		return retcode;
2087 	if (retcode != NO_ERROR)
2088 		goto out;
2089 	if (!(adm_ctx.my_addr && adm_ctx.peer_addr)) {
2090 		drbd_msg_put_info("connection endpoint(s) missing");
2091 		retcode = ERR_INVALID_REQUEST;
2092 		goto out;
2093 	}
2094 
2095 	/* No need for _rcu here. All reconfiguration is
2096 	 * strictly serialized on genl_lock(). We are protected against
2097 	 * concurrent reconfiguration/addition/deletion */
2098 	list_for_each_entry(tconn, &drbd_tconns, all_tconn) {
2099 		if (nla_len(adm_ctx.my_addr) == tconn->my_addr_len &&
2100 		    !memcmp(nla_data(adm_ctx.my_addr), &tconn->my_addr, tconn->my_addr_len)) {
2101 			retcode = ERR_LOCAL_ADDR;
2102 			goto out;
2103 		}
2104 
2105 		if (nla_len(adm_ctx.peer_addr) == tconn->peer_addr_len &&
2106 		    !memcmp(nla_data(adm_ctx.peer_addr), &tconn->peer_addr, tconn->peer_addr_len)) {
2107 			retcode = ERR_PEER_ADDR;
2108 			goto out;
2109 		}
2110 	}
2111 
2112 	tconn = adm_ctx.tconn;
2113 	conn_reconfig_start(tconn);
2114 
2115 	if (tconn->cstate > C_STANDALONE) {
2116 		retcode = ERR_NET_CONFIGURED;
2117 		goto fail;
2118 	}
2119 
2120 	/* allocation not in the IO path, drbdsetup / netlink process context */
2121 	new_conf = kzalloc(sizeof(*new_conf), GFP_KERNEL);
2122 	if (!new_conf) {
2123 		retcode = ERR_NOMEM;
2124 		goto fail;
2125 	}
2126 
2127 	set_net_conf_defaults(new_conf);
2128 
2129 	err = net_conf_from_attrs(new_conf, info);
2130 	if (err && err != -ENOMSG) {
2131 		retcode = ERR_MANDATORY_TAG;
2132 		drbd_msg_put_info(from_attrs_err_to_txt(err));
2133 		goto fail;
2134 	}
2135 
2136 	retcode = check_net_options(tconn, new_conf);
2137 	if (retcode != NO_ERROR)
2138 		goto fail;
2139 
2140 	retcode = alloc_crypto(&crypto, new_conf);
2141 	if (retcode != NO_ERROR)
2142 		goto fail;
2143 
2144 	((char *)new_conf->shared_secret)[SHARED_SECRET_MAX-1] = 0;
2145 
2146 	conn_flush_workqueue(tconn);
2147 
2148 	mutex_lock(&tconn->conf_update);
2149 	old_conf = tconn->net_conf;
2150 	if (old_conf) {
2151 		retcode = ERR_NET_CONFIGURED;
2152 		mutex_unlock(&tconn->conf_update);
2153 		goto fail;
2154 	}
2155 	rcu_assign_pointer(tconn->net_conf, new_conf);
2156 
2157 	conn_free_crypto(tconn);
2158 	tconn->cram_hmac_tfm = crypto.cram_hmac_tfm;
2159 	tconn->integrity_tfm = crypto.integrity_tfm;
2160 	tconn->csums_tfm = crypto.csums_tfm;
2161 	tconn->verify_tfm = crypto.verify_tfm;
2162 
2163 	tconn->my_addr_len = nla_len(adm_ctx.my_addr);
2164 	memcpy(&tconn->my_addr, nla_data(adm_ctx.my_addr), tconn->my_addr_len);
2165 	tconn->peer_addr_len = nla_len(adm_ctx.peer_addr);
2166 	memcpy(&tconn->peer_addr, nla_data(adm_ctx.peer_addr), tconn->peer_addr_len);
2167 
2168 	mutex_unlock(&tconn->conf_update);
2169 
2170 	rcu_read_lock();
2171 	idr_for_each_entry(&tconn->volumes, mdev, i) {
2172 		mdev->send_cnt = 0;
2173 		mdev->recv_cnt = 0;
2174 	}
2175 	rcu_read_unlock();
2176 
2177 	retcode = conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);
2178 
2179 	conn_reconfig_done(tconn);
2180 	drbd_adm_finish(info, retcode);
2181 	return 0;
2182 
2183 fail:
2184 	free_crypto(&crypto);
2185 	kfree(new_conf);
2186 
2187 	conn_reconfig_done(tconn);
2188 out:
2189 	drbd_adm_finish(info, retcode);
2190 	return 0;
2191 }
2192 
2193 static enum drbd_state_rv conn_try_disconnect(struct drbd_tconn *tconn, bool force)
2194 {
2195 	enum drbd_state_rv rv;
2196 
2197 	rv = conn_request_state(tconn, NS(conn, C_DISCONNECTING),
2198 			force ? CS_HARD : 0);
2199 
2200 	switch (rv) {
2201 	case SS_NOTHING_TO_DO:
2202 		break;
2203 	case SS_ALREADY_STANDALONE:
2204 		return SS_SUCCESS;
2205 	case SS_PRIMARY_NOP:
2206 		/* Our state checking code wants to see the peer outdated. */
2207 		rv = conn_request_state(tconn, NS2(conn, C_DISCONNECTING, pdsk, D_OUTDATED), 0);
2208 
2209 		if (rv == SS_OUTDATE_WO_CONN) /* lost connection before graceful disconnect succeeded */
2210 			rv = conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_VERBOSE);
2211 
2212 		break;
2213 	case SS_CW_FAILED_BY_PEER:
2214 		/* The peer probably wants to see us outdated. */
2215 		rv = conn_request_state(tconn, NS2(conn, C_DISCONNECTING,
2216 							disk, D_OUTDATED), 0);
2217 		if (rv == SS_IS_DISKLESS || rv == SS_LOWER_THAN_OUTDATED) {
2218 			rv = conn_request_state(tconn, NS(conn, C_DISCONNECTING),
2219 					CS_HARD);
2220 		}
2221 		break;
2222 	default:;
2223 		/* no special handling necessary */
2224 	}
2225 
2226 	if (rv >= SS_SUCCESS) {
2227 		enum drbd_state_rv rv2;
2228 		/* No one else can reconfigure the network while I am here.
2229 		 * The state handling only uses drbd_thread_stop_nowait(),
2230 		 * we want to really wait here until the receiver is no more.
2231 		 */
2232 		drbd_thread_stop(&adm_ctx.tconn->receiver);
2233 
2234 		/* Race breaker.  This additional state change request may be
2235 		 * necessary, if this was a forced disconnect during a receiver
2236 		 * restart.  We may have "killed" the receiver thread just
2237 		 * after drbdd_init() returned.  Typically, we should be
2238 		 * C_STANDALONE already, now, and this becomes a no-op.
2239 		 */
2240 		rv2 = conn_request_state(tconn, NS(conn, C_STANDALONE),
2241 				CS_VERBOSE | CS_HARD);
2242 		if (rv2 < SS_SUCCESS)
2243 			conn_err(tconn,
2244 				"unexpected rv2=%d in conn_try_disconnect()\n",
2245 				rv2);
2246 	}
2247 	return rv;
2248 }
2249 
2250 int drbd_adm_disconnect(struct sk_buff *skb, struct genl_info *info)
2251 {
2252 	struct disconnect_parms parms;
2253 	struct drbd_tconn *tconn;
2254 	enum drbd_state_rv rv;
2255 	enum drbd_ret_code retcode;
2256 	int err;
2257 
2258 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_CONNECTION);
2259 	if (!adm_ctx.reply_skb)
2260 		return retcode;
2261 	if (retcode != NO_ERROR)
2262 		goto fail;
2263 
2264 	tconn = adm_ctx.tconn;
2265 	memset(&parms, 0, sizeof(parms));
2266 	if (info->attrs[DRBD_NLA_DISCONNECT_PARMS]) {
2267 		err = disconnect_parms_from_attrs(&parms, info);
2268 		if (err) {
2269 			retcode = ERR_MANDATORY_TAG;
2270 			drbd_msg_put_info(from_attrs_err_to_txt(err));
2271 			goto fail;
2272 		}
2273 	}
2274 
2275 	rv = conn_try_disconnect(tconn, parms.force_disconnect);
2276 	if (rv < SS_SUCCESS)
2277 		retcode = rv;  /* FIXME: Type mismatch. */
2278 	else
2279 		retcode = NO_ERROR;
2280  fail:
2281 	drbd_adm_finish(info, retcode);
2282 	return 0;
2283 }
2284 
2285 void resync_after_online_grow(struct drbd_conf *mdev)
2286 {
2287 	int iass; /* I am sync source */
2288 
2289 	dev_info(DEV, "Resync of new storage after online grow\n");
2290 	if (mdev->state.role != mdev->state.peer)
2291 		iass = (mdev->state.role == R_PRIMARY);
2292 	else
2293 		iass = test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags);
2294 
2295 	if (iass)
2296 		drbd_start_resync(mdev, C_SYNC_SOURCE);
2297 	else
2298 		_drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE + CS_SERIALIZE);
2299 }
2300 
2301 int drbd_adm_resize(struct sk_buff *skb, struct genl_info *info)
2302 {
2303 	struct disk_conf *old_disk_conf, *new_disk_conf = NULL;
2304 	struct resize_parms rs;
2305 	struct drbd_conf *mdev;
2306 	enum drbd_ret_code retcode;
2307 	enum determine_dev_size dd;
2308 	enum dds_flags ddsf;
2309 	sector_t u_size;
2310 	int err;
2311 
2312 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2313 	if (!adm_ctx.reply_skb)
2314 		return retcode;
2315 	if (retcode != NO_ERROR)
2316 		goto fail;
2317 
2318 	memset(&rs, 0, sizeof(struct resize_parms));
2319 	if (info->attrs[DRBD_NLA_RESIZE_PARMS]) {
2320 		err = resize_parms_from_attrs(&rs, info);
2321 		if (err) {
2322 			retcode = ERR_MANDATORY_TAG;
2323 			drbd_msg_put_info(from_attrs_err_to_txt(err));
2324 			goto fail;
2325 		}
2326 	}
2327 
2328 	mdev = adm_ctx.mdev;
2329 	if (mdev->state.conn > C_CONNECTED) {
2330 		retcode = ERR_RESIZE_RESYNC;
2331 		goto fail;
2332 	}
2333 
2334 	if (mdev->state.role == R_SECONDARY &&
2335 	    mdev->state.peer == R_SECONDARY) {
2336 		retcode = ERR_NO_PRIMARY;
2337 		goto fail;
2338 	}
2339 
2340 	if (!get_ldev(mdev)) {
2341 		retcode = ERR_NO_DISK;
2342 		goto fail;
2343 	}
2344 
2345 	if (rs.no_resync && mdev->tconn->agreed_pro_version < 93) {
2346 		retcode = ERR_NEED_APV_93;
2347 		goto fail_ldev;
2348 	}
2349 
2350 	rcu_read_lock();
2351 	u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
2352 	rcu_read_unlock();
2353 	if (u_size != (sector_t)rs.resize_size) {
2354 		new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
2355 		if (!new_disk_conf) {
2356 			retcode = ERR_NOMEM;
2357 			goto fail_ldev;
2358 		}
2359 	}
2360 
2361 	if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev))
2362 		mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
2363 
2364 	if (new_disk_conf) {
2365 		mutex_lock(&mdev->tconn->conf_update);
2366 		old_disk_conf = mdev->ldev->disk_conf;
2367 		*new_disk_conf = *old_disk_conf;
2368 		new_disk_conf->disk_size = (sector_t)rs.resize_size;
2369 		rcu_assign_pointer(mdev->ldev->disk_conf, new_disk_conf);
2370 		mutex_unlock(&mdev->tconn->conf_update);
2371 		synchronize_rcu();
2372 		kfree(old_disk_conf);
2373 	}
2374 
2375 	ddsf = (rs.resize_force ? DDSF_FORCED : 0) | (rs.no_resync ? DDSF_NO_RESYNC : 0);
2376 	dd = drbd_determine_dev_size(mdev, ddsf);
2377 	drbd_md_sync(mdev);
2378 	put_ldev(mdev);
2379 	if (dd == dev_size_error) {
2380 		retcode = ERR_NOMEM_BITMAP;
2381 		goto fail;
2382 	}
2383 
2384 	if (mdev->state.conn == C_CONNECTED) {
2385 		if (dd == grew)
2386 			set_bit(RESIZE_PENDING, &mdev->flags);
2387 
2388 		drbd_send_uuids(mdev);
2389 		drbd_send_sizes(mdev, 1, ddsf);
2390 	}
2391 
2392  fail:
2393 	drbd_adm_finish(info, retcode);
2394 	return 0;
2395 
2396  fail_ldev:
2397 	put_ldev(mdev);
2398 	goto fail;
2399 }
2400 
2401 int drbd_adm_resource_opts(struct sk_buff *skb, struct genl_info *info)
2402 {
2403 	enum drbd_ret_code retcode;
2404 	struct drbd_tconn *tconn;
2405 	struct res_opts res_opts;
2406 	int err;
2407 
2408 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_RESOURCE);
2409 	if (!adm_ctx.reply_skb)
2410 		return retcode;
2411 	if (retcode != NO_ERROR)
2412 		goto fail;
2413 	tconn = adm_ctx.tconn;
2414 
2415 	res_opts = tconn->res_opts;
2416 	if (should_set_defaults(info))
2417 		set_res_opts_defaults(&res_opts);
2418 
2419 	err = res_opts_from_attrs(&res_opts, info);
2420 	if (err && err != -ENOMSG) {
2421 		retcode = ERR_MANDATORY_TAG;
2422 		drbd_msg_put_info(from_attrs_err_to_txt(err));
2423 		goto fail;
2424 	}
2425 
2426 	err = set_resource_options(tconn, &res_opts);
2427 	if (err) {
2428 		retcode = ERR_INVALID_REQUEST;
2429 		if (err == -ENOMEM)
2430 			retcode = ERR_NOMEM;
2431 	}
2432 
2433 fail:
2434 	drbd_adm_finish(info, retcode);
2435 	return 0;
2436 }
2437 
2438 int drbd_adm_invalidate(struct sk_buff *skb, struct genl_info *info)
2439 {
2440 	struct drbd_conf *mdev;
2441 	int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
2442 
2443 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2444 	if (!adm_ctx.reply_skb)
2445 		return retcode;
2446 	if (retcode != NO_ERROR)
2447 		goto out;
2448 
2449 	mdev = adm_ctx.mdev;
2450 
2451 	/* If there is still bitmap IO pending, probably because of a previous
2452 	 * resync just being finished, wait for it before requesting a new resync.
2453 	 * Also wait for it's after_state_ch(). */
2454 	drbd_suspend_io(mdev);
2455 	wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
2456 	drbd_flush_workqueue(mdev);
2457 
2458 	/* If we happen to be C_STANDALONE R_SECONDARY, just change to
2459 	 * D_INCONSISTENT, and set all bits in the bitmap.  Otherwise,
2460 	 * try to start a resync handshake as sync target for full sync.
2461 	 */
2462 	if (mdev->state.conn == C_STANDALONE && mdev->state.role == R_SECONDARY) {
2463 		retcode = drbd_request_state(mdev, NS(disk, D_INCONSISTENT));
2464 		if (retcode >= SS_SUCCESS) {
2465 			if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write,
2466 				"set_n_write from invalidate", BM_LOCKED_MASK))
2467 				retcode = ERR_IO_MD_DISK;
2468 		}
2469 	} else
2470 		retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T));
2471 	drbd_resume_io(mdev);
2472 
2473 out:
2474 	drbd_adm_finish(info, retcode);
2475 	return 0;
2476 }
2477 
2478 static int drbd_adm_simple_request_state(struct sk_buff *skb, struct genl_info *info,
2479 		union drbd_state mask, union drbd_state val)
2480 {
2481 	enum drbd_ret_code retcode;
2482 
2483 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2484 	if (!adm_ctx.reply_skb)
2485 		return retcode;
2486 	if (retcode != NO_ERROR)
2487 		goto out;
2488 
2489 	retcode = drbd_request_state(adm_ctx.mdev, mask, val);
2490 out:
2491 	drbd_adm_finish(info, retcode);
2492 	return 0;
2493 }
2494 
2495 static int drbd_bmio_set_susp_al(struct drbd_conf *mdev)
2496 {
2497 	int rv;
2498 
2499 	rv = drbd_bmio_set_n_write(mdev);
2500 	drbd_suspend_al(mdev);
2501 	return rv;
2502 }
2503 
2504 int drbd_adm_invalidate_peer(struct sk_buff *skb, struct genl_info *info)
2505 {
2506 	int retcode; /* drbd_ret_code, drbd_state_rv */
2507 	struct drbd_conf *mdev;
2508 
2509 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2510 	if (!adm_ctx.reply_skb)
2511 		return retcode;
2512 	if (retcode != NO_ERROR)
2513 		goto out;
2514 
2515 	mdev = adm_ctx.mdev;
2516 
2517 	/* If there is still bitmap IO pending, probably because of a previous
2518 	 * resync just being finished, wait for it before requesting a new resync.
2519 	 * Also wait for it's after_state_ch(). */
2520 	drbd_suspend_io(mdev);
2521 	wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
2522 	drbd_flush_workqueue(mdev);
2523 
2524 	/* If we happen to be C_STANDALONE R_PRIMARY, just set all bits
2525 	 * in the bitmap.  Otherwise, try to start a resync handshake
2526 	 * as sync source for full sync.
2527 	 */
2528 	if (mdev->state.conn == C_STANDALONE && mdev->state.role == R_PRIMARY) {
2529 		/* The peer will get a resync upon connect anyways. Just make that
2530 		   into a full resync. */
2531 		retcode = drbd_request_state(mdev, NS(pdsk, D_INCONSISTENT));
2532 		if (retcode >= SS_SUCCESS) {
2533 			if (drbd_bitmap_io(mdev, &drbd_bmio_set_susp_al,
2534 				"set_n_write from invalidate_peer",
2535 				BM_LOCKED_SET_ALLOWED))
2536 				retcode = ERR_IO_MD_DISK;
2537 		}
2538 	} else
2539 		retcode = drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S));
2540 	drbd_resume_io(mdev);
2541 
2542 out:
2543 	drbd_adm_finish(info, retcode);
2544 	return 0;
2545 }
2546 
2547 int drbd_adm_pause_sync(struct sk_buff *skb, struct genl_info *info)
2548 {
2549 	enum drbd_ret_code retcode;
2550 
2551 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2552 	if (!adm_ctx.reply_skb)
2553 		return retcode;
2554 	if (retcode != NO_ERROR)
2555 		goto out;
2556 
2557 	if (drbd_request_state(adm_ctx.mdev, NS(user_isp, 1)) == SS_NOTHING_TO_DO)
2558 		retcode = ERR_PAUSE_IS_SET;
2559 out:
2560 	drbd_adm_finish(info, retcode);
2561 	return 0;
2562 }
2563 
2564 int drbd_adm_resume_sync(struct sk_buff *skb, struct genl_info *info)
2565 {
2566 	union drbd_dev_state s;
2567 	enum drbd_ret_code retcode;
2568 
2569 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2570 	if (!adm_ctx.reply_skb)
2571 		return retcode;
2572 	if (retcode != NO_ERROR)
2573 		goto out;
2574 
2575 	if (drbd_request_state(adm_ctx.mdev, NS(user_isp, 0)) == SS_NOTHING_TO_DO) {
2576 		s = adm_ctx.mdev->state;
2577 		if (s.conn == C_PAUSED_SYNC_S || s.conn == C_PAUSED_SYNC_T) {
2578 			retcode = s.aftr_isp ? ERR_PIC_AFTER_DEP :
2579 				  s.peer_isp ? ERR_PIC_PEER_DEP : ERR_PAUSE_IS_CLEAR;
2580 		} else {
2581 			retcode = ERR_PAUSE_IS_CLEAR;
2582 		}
2583 	}
2584 
2585 out:
2586 	drbd_adm_finish(info, retcode);
2587 	return 0;
2588 }
2589 
2590 int drbd_adm_suspend_io(struct sk_buff *skb, struct genl_info *info)
2591 {
2592 	return drbd_adm_simple_request_state(skb, info, NS(susp, 1));
2593 }
2594 
2595 int drbd_adm_resume_io(struct sk_buff *skb, struct genl_info *info)
2596 {
2597 	struct drbd_conf *mdev;
2598 	int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
2599 
2600 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2601 	if (!adm_ctx.reply_skb)
2602 		return retcode;
2603 	if (retcode != NO_ERROR)
2604 		goto out;
2605 
2606 	mdev = adm_ctx.mdev;
2607 	if (test_bit(NEW_CUR_UUID, &mdev->flags)) {
2608 		drbd_uuid_new_current(mdev);
2609 		clear_bit(NEW_CUR_UUID, &mdev->flags);
2610 	}
2611 	drbd_suspend_io(mdev);
2612 	retcode = drbd_request_state(mdev, NS3(susp, 0, susp_nod, 0, susp_fen, 0));
2613 	if (retcode == SS_SUCCESS) {
2614 		if (mdev->state.conn < C_CONNECTED)
2615 			tl_clear(mdev->tconn);
2616 		if (mdev->state.disk == D_DISKLESS || mdev->state.disk == D_FAILED)
2617 			tl_restart(mdev->tconn, FAIL_FROZEN_DISK_IO);
2618 	}
2619 	drbd_resume_io(mdev);
2620 
2621 out:
2622 	drbd_adm_finish(info, retcode);
2623 	return 0;
2624 }
2625 
2626 int drbd_adm_outdate(struct sk_buff *skb, struct genl_info *info)
2627 {
2628 	return drbd_adm_simple_request_state(skb, info, NS(disk, D_OUTDATED));
2629 }
2630 
2631 int nla_put_drbd_cfg_context(struct sk_buff *skb, struct drbd_tconn *tconn, unsigned vnr)
2632 {
2633 	struct nlattr *nla;
2634 	nla = nla_nest_start(skb, DRBD_NLA_CFG_CONTEXT);
2635 	if (!nla)
2636 		goto nla_put_failure;
2637 	if (vnr != VOLUME_UNSPECIFIED &&
2638 	    nla_put_u32(skb, T_ctx_volume, vnr))
2639 		goto nla_put_failure;
2640 	if (nla_put_string(skb, T_ctx_resource_name, tconn->name))
2641 		goto nla_put_failure;
2642 	if (tconn->my_addr_len &&
2643 	    nla_put(skb, T_ctx_my_addr, tconn->my_addr_len, &tconn->my_addr))
2644 		goto nla_put_failure;
2645 	if (tconn->peer_addr_len &&
2646 	    nla_put(skb, T_ctx_peer_addr, tconn->peer_addr_len, &tconn->peer_addr))
2647 		goto nla_put_failure;
2648 	nla_nest_end(skb, nla);
2649 	return 0;
2650 
2651 nla_put_failure:
2652 	if (nla)
2653 		nla_nest_cancel(skb, nla);
2654 	return -EMSGSIZE;
2655 }
2656 
2657 int nla_put_status_info(struct sk_buff *skb, struct drbd_conf *mdev,
2658 		const struct sib_info *sib)
2659 {
2660 	struct state_info *si = NULL; /* for sizeof(si->member); */
2661 	struct net_conf *nc;
2662 	struct nlattr *nla;
2663 	int got_ldev;
2664 	int err = 0;
2665 	int exclude_sensitive;
2666 
2667 	/* If sib != NULL, this is drbd_bcast_event, which anyone can listen
2668 	 * to.  So we better exclude_sensitive information.
2669 	 *
2670 	 * If sib == NULL, this is drbd_adm_get_status, executed synchronously
2671 	 * in the context of the requesting user process. Exclude sensitive
2672 	 * information, unless current has superuser.
2673 	 *
2674 	 * NOTE: for drbd_adm_get_status_all(), this is a netlink dump, and
2675 	 * relies on the current implementation of netlink_dump(), which
2676 	 * executes the dump callback successively from netlink_recvmsg(),
2677 	 * always in the context of the receiving process */
2678 	exclude_sensitive = sib || !capable(CAP_SYS_ADMIN);
2679 
2680 	got_ldev = get_ldev(mdev);
2681 
2682 	/* We need to add connection name and volume number information still.
2683 	 * Minor number is in drbd_genlmsghdr. */
2684 	if (nla_put_drbd_cfg_context(skb, mdev->tconn, mdev->vnr))
2685 		goto nla_put_failure;
2686 
2687 	if (res_opts_to_skb(skb, &mdev->tconn->res_opts, exclude_sensitive))
2688 		goto nla_put_failure;
2689 
2690 	rcu_read_lock();
2691 	if (got_ldev)
2692 		if (disk_conf_to_skb(skb, rcu_dereference(mdev->ldev->disk_conf), exclude_sensitive))
2693 			goto nla_put_failure;
2694 
2695 	nc = rcu_dereference(mdev->tconn->net_conf);
2696 	if (nc)
2697 		err = net_conf_to_skb(skb, nc, exclude_sensitive);
2698 	rcu_read_unlock();
2699 	if (err)
2700 		goto nla_put_failure;
2701 
2702 	nla = nla_nest_start(skb, DRBD_NLA_STATE_INFO);
2703 	if (!nla)
2704 		goto nla_put_failure;
2705 	if (nla_put_u32(skb, T_sib_reason, sib ? sib->sib_reason : SIB_GET_STATUS_REPLY) ||
2706 	    nla_put_u32(skb, T_current_state, mdev->state.i) ||
2707 	    nla_put_u64(skb, T_ed_uuid, mdev->ed_uuid) ||
2708 	    nla_put_u64(skb, T_capacity, drbd_get_capacity(mdev->this_bdev)) ||
2709 	    nla_put_u64(skb, T_send_cnt, mdev->send_cnt) ||
2710 	    nla_put_u64(skb, T_recv_cnt, mdev->recv_cnt) ||
2711 	    nla_put_u64(skb, T_read_cnt, mdev->read_cnt) ||
2712 	    nla_put_u64(skb, T_writ_cnt, mdev->writ_cnt) ||
2713 	    nla_put_u64(skb, T_al_writ_cnt, mdev->al_writ_cnt) ||
2714 	    nla_put_u64(skb, T_bm_writ_cnt, mdev->bm_writ_cnt) ||
2715 	    nla_put_u32(skb, T_ap_bio_cnt, atomic_read(&mdev->ap_bio_cnt)) ||
2716 	    nla_put_u32(skb, T_ap_pending_cnt, atomic_read(&mdev->ap_pending_cnt)) ||
2717 	    nla_put_u32(skb, T_rs_pending_cnt, atomic_read(&mdev->rs_pending_cnt)))
2718 		goto nla_put_failure;
2719 
2720 	if (got_ldev) {
2721 		int err;
2722 
2723 		spin_lock_irq(&mdev->ldev->md.uuid_lock);
2724 		err = nla_put(skb, T_uuids, sizeof(si->uuids), mdev->ldev->md.uuid);
2725 		spin_unlock_irq(&mdev->ldev->md.uuid_lock);
2726 
2727 		if (err)
2728 			goto nla_put_failure;
2729 
2730 		if (nla_put_u32(skb, T_disk_flags, mdev->ldev->md.flags) ||
2731 		    nla_put_u64(skb, T_bits_total, drbd_bm_bits(mdev)) ||
2732 		    nla_put_u64(skb, T_bits_oos, drbd_bm_total_weight(mdev)))
2733 			goto nla_put_failure;
2734 		if (C_SYNC_SOURCE <= mdev->state.conn &&
2735 		    C_PAUSED_SYNC_T >= mdev->state.conn) {
2736 			if (nla_put_u64(skb, T_bits_rs_total, mdev->rs_total) ||
2737 			    nla_put_u64(skb, T_bits_rs_failed, mdev->rs_failed))
2738 				goto nla_put_failure;
2739 		}
2740 	}
2741 
2742 	if (sib) {
2743 		switch(sib->sib_reason) {
2744 		case SIB_SYNC_PROGRESS:
2745 		case SIB_GET_STATUS_REPLY:
2746 			break;
2747 		case SIB_STATE_CHANGE:
2748 			if (nla_put_u32(skb, T_prev_state, sib->os.i) ||
2749 			    nla_put_u32(skb, T_new_state, sib->ns.i))
2750 				goto nla_put_failure;
2751 			break;
2752 		case SIB_HELPER_POST:
2753 			if (nla_put_u32(skb, T_helper_exit_code,
2754 					sib->helper_exit_code))
2755 				goto nla_put_failure;
2756 			/* fall through */
2757 		case SIB_HELPER_PRE:
2758 			if (nla_put_string(skb, T_helper, sib->helper_name))
2759 				goto nla_put_failure;
2760 			break;
2761 		}
2762 	}
2763 	nla_nest_end(skb, nla);
2764 
2765 	if (0)
2766 nla_put_failure:
2767 		err = -EMSGSIZE;
2768 	if (got_ldev)
2769 		put_ldev(mdev);
2770 	return err;
2771 }
2772 
2773 int drbd_adm_get_status(struct sk_buff *skb, struct genl_info *info)
2774 {
2775 	enum drbd_ret_code retcode;
2776 	int err;
2777 
2778 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2779 	if (!adm_ctx.reply_skb)
2780 		return retcode;
2781 	if (retcode != NO_ERROR)
2782 		goto out;
2783 
2784 	err = nla_put_status_info(adm_ctx.reply_skb, adm_ctx.mdev, NULL);
2785 	if (err) {
2786 		nlmsg_free(adm_ctx.reply_skb);
2787 		return err;
2788 	}
2789 out:
2790 	drbd_adm_finish(info, retcode);
2791 	return 0;
2792 }
2793 
2794 int get_one_status(struct sk_buff *skb, struct netlink_callback *cb)
2795 {
2796 	struct drbd_conf *mdev;
2797 	struct drbd_genlmsghdr *dh;
2798 	struct drbd_tconn *pos = (struct drbd_tconn*)cb->args[0];
2799 	struct drbd_tconn *tconn = NULL;
2800 	struct drbd_tconn *tmp;
2801 	unsigned volume = cb->args[1];
2802 
2803 	/* Open coded, deferred, iteration:
2804 	 * list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
2805 	 *	idr_for_each_entry(&tconn->volumes, mdev, i) {
2806 	 *	  ...
2807 	 *	}
2808 	 * }
2809 	 * where tconn is cb->args[0];
2810 	 * and i is cb->args[1];
2811 	 *
2812 	 * cb->args[2] indicates if we shall loop over all resources,
2813 	 * or just dump all volumes of a single resource.
2814 	 *
2815 	 * This may miss entries inserted after this dump started,
2816 	 * or entries deleted before they are reached.
2817 	 *
2818 	 * We need to make sure the mdev won't disappear while
2819 	 * we are looking at it, and revalidate our iterators
2820 	 * on each iteration.
2821 	 */
2822 
2823 	/* synchronize with conn_create()/conn_destroy() */
2824 	rcu_read_lock();
2825 	/* revalidate iterator position */
2826 	list_for_each_entry_rcu(tmp, &drbd_tconns, all_tconn) {
2827 		if (pos == NULL) {
2828 			/* first iteration */
2829 			pos = tmp;
2830 			tconn = pos;
2831 			break;
2832 		}
2833 		if (tmp == pos) {
2834 			tconn = pos;
2835 			break;
2836 		}
2837 	}
2838 	if (tconn) {
2839 next_tconn:
2840 		mdev = idr_get_next(&tconn->volumes, &volume);
2841 		if (!mdev) {
2842 			/* No more volumes to dump on this tconn.
2843 			 * Advance tconn iterator. */
2844 			pos = list_entry_rcu(tconn->all_tconn.next,
2845 					     struct drbd_tconn, all_tconn);
2846 			/* Did we dump any volume on this tconn yet? */
2847 			if (volume != 0) {
2848 				/* If we reached the end of the list,
2849 				 * or only a single resource dump was requested,
2850 				 * we are done. */
2851 				if (&pos->all_tconn == &drbd_tconns || cb->args[2])
2852 					goto out;
2853 				volume = 0;
2854 				tconn = pos;
2855 				goto next_tconn;
2856 			}
2857 		}
2858 
2859 		dh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2860 				cb->nlh->nlmsg_seq, &drbd_genl_family,
2861 				NLM_F_MULTI, DRBD_ADM_GET_STATUS);
2862 		if (!dh)
2863 			goto out;
2864 
2865 		if (!mdev) {
2866 			/* This is a tconn without a single volume.
2867 			 * Suprisingly enough, it may have a network
2868 			 * configuration. */
2869 			struct net_conf *nc;
2870 			dh->minor = -1U;
2871 			dh->ret_code = NO_ERROR;
2872 			if (nla_put_drbd_cfg_context(skb, tconn, VOLUME_UNSPECIFIED))
2873 				goto cancel;
2874 			nc = rcu_dereference(tconn->net_conf);
2875 			if (nc && net_conf_to_skb(skb, nc, 1) != 0)
2876 				goto cancel;
2877 			goto done;
2878 		}
2879 
2880 		D_ASSERT(mdev->vnr == volume);
2881 		D_ASSERT(mdev->tconn == tconn);
2882 
2883 		dh->minor = mdev_to_minor(mdev);
2884 		dh->ret_code = NO_ERROR;
2885 
2886 		if (nla_put_status_info(skb, mdev, NULL)) {
2887 cancel:
2888 			genlmsg_cancel(skb, dh);
2889 			goto out;
2890 		}
2891 done:
2892 		genlmsg_end(skb, dh);
2893         }
2894 
2895 out:
2896 	rcu_read_unlock();
2897 	/* where to start the next iteration */
2898         cb->args[0] = (long)pos;
2899         cb->args[1] = (pos == tconn) ? volume + 1 : 0;
2900 
2901 	/* No more tconns/volumes/minors found results in an empty skb.
2902 	 * Which will terminate the dump. */
2903         return skb->len;
2904 }
2905 
2906 /*
2907  * Request status of all resources, or of all volumes within a single resource.
2908  *
2909  * This is a dump, as the answer may not fit in a single reply skb otherwise.
2910  * Which means we cannot use the family->attrbuf or other such members, because
2911  * dump is NOT protected by the genl_lock().  During dump, we only have access
2912  * to the incoming skb, and need to opencode "parsing" of the nlattr payload.
2913  *
2914  * Once things are setup properly, we call into get_one_status().
2915  */
2916 int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
2917 {
2918 	const unsigned hdrlen = GENL_HDRLEN + GENL_MAGIC_FAMILY_HDRSZ;
2919 	struct nlattr *nla;
2920 	const char *resource_name;
2921 	struct drbd_tconn *tconn;
2922 	int maxtype;
2923 
2924 	/* Is this a followup call? */
2925 	if (cb->args[0]) {
2926 		/* ... of a single resource dump,
2927 		 * and the resource iterator has been advanced already? */
2928 		if (cb->args[2] && cb->args[2] != cb->args[0])
2929 			return 0; /* DONE. */
2930 		goto dump;
2931 	}
2932 
2933 	/* First call (from netlink_dump_start).  We need to figure out
2934 	 * which resource(s) the user wants us to dump. */
2935 	nla = nla_find(nlmsg_attrdata(cb->nlh, hdrlen),
2936 			nlmsg_attrlen(cb->nlh, hdrlen),
2937 			DRBD_NLA_CFG_CONTEXT);
2938 
2939 	/* No explicit context given.  Dump all. */
2940 	if (!nla)
2941 		goto dump;
2942 	maxtype = ARRAY_SIZE(drbd_cfg_context_nl_policy) - 1;
2943 	nla = drbd_nla_find_nested(maxtype, nla, __nla_type(T_ctx_resource_name));
2944 	if (IS_ERR(nla))
2945 		return PTR_ERR(nla);
2946 	/* context given, but no name present? */
2947 	if (!nla)
2948 		return -EINVAL;
2949 	resource_name = nla_data(nla);
2950 	tconn = conn_get_by_name(resource_name);
2951 
2952 	if (!tconn)
2953 		return -ENODEV;
2954 
2955 	kref_put(&tconn->kref, &conn_destroy); /* get_one_status() (re)validates tconn by itself */
2956 
2957 	/* prime iterators, and set "filter" mode mark:
2958 	 * only dump this tconn. */
2959 	cb->args[0] = (long)tconn;
2960 	/* cb->args[1] = 0; passed in this way. */
2961 	cb->args[2] = (long)tconn;
2962 
2963 dump:
2964 	return get_one_status(skb, cb);
2965 }
2966 
2967 int drbd_adm_get_timeout_type(struct sk_buff *skb, struct genl_info *info)
2968 {
2969 	enum drbd_ret_code retcode;
2970 	struct timeout_parms tp;
2971 	int err;
2972 
2973 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
2974 	if (!adm_ctx.reply_skb)
2975 		return retcode;
2976 	if (retcode != NO_ERROR)
2977 		goto out;
2978 
2979 	tp.timeout_type =
2980 		adm_ctx.mdev->state.pdsk == D_OUTDATED ? UT_PEER_OUTDATED :
2981 		test_bit(USE_DEGR_WFC_T, &adm_ctx.mdev->flags) ? UT_DEGRADED :
2982 		UT_DEFAULT;
2983 
2984 	err = timeout_parms_to_priv_skb(adm_ctx.reply_skb, &tp);
2985 	if (err) {
2986 		nlmsg_free(adm_ctx.reply_skb);
2987 		return err;
2988 	}
2989 out:
2990 	drbd_adm_finish(info, retcode);
2991 	return 0;
2992 }
2993 
2994 int drbd_adm_start_ov(struct sk_buff *skb, struct genl_info *info)
2995 {
2996 	struct drbd_conf *mdev;
2997 	enum drbd_ret_code retcode;
2998 	struct start_ov_parms parms;
2999 
3000 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
3001 	if (!adm_ctx.reply_skb)
3002 		return retcode;
3003 	if (retcode != NO_ERROR)
3004 		goto out;
3005 
3006 	mdev = adm_ctx.mdev;
3007 
3008 	/* resume from last known position, if possible */
3009 	parms.ov_start_sector = mdev->ov_start_sector;
3010 	parms.ov_stop_sector = ULLONG_MAX;
3011 	if (info->attrs[DRBD_NLA_START_OV_PARMS]) {
3012 		int err = start_ov_parms_from_attrs(&parms, info);
3013 		if (err) {
3014 			retcode = ERR_MANDATORY_TAG;
3015 			drbd_msg_put_info(from_attrs_err_to_txt(err));
3016 			goto out;
3017 		}
3018 	}
3019 	/* w_make_ov_request expects position to be aligned */
3020 	mdev->ov_start_sector = parms.ov_start_sector & ~(BM_SECT_PER_BIT-1);
3021 	mdev->ov_stop_sector = parms.ov_stop_sector;
3022 
3023 	/* If there is still bitmap IO pending, e.g. previous resync or verify
3024 	 * just being finished, wait for it before requesting a new resync. */
3025 	drbd_suspend_io(mdev);
3026 	wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
3027 	retcode = drbd_request_state(mdev,NS(conn,C_VERIFY_S));
3028 	drbd_resume_io(mdev);
3029 out:
3030 	drbd_adm_finish(info, retcode);
3031 	return 0;
3032 }
3033 
3034 
3035 int drbd_adm_new_c_uuid(struct sk_buff *skb, struct genl_info *info)
3036 {
3037 	struct drbd_conf *mdev;
3038 	enum drbd_ret_code retcode;
3039 	int skip_initial_sync = 0;
3040 	int err;
3041 	struct new_c_uuid_parms args;
3042 
3043 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
3044 	if (!adm_ctx.reply_skb)
3045 		return retcode;
3046 	if (retcode != NO_ERROR)
3047 		goto out_nolock;
3048 
3049 	mdev = adm_ctx.mdev;
3050 	memset(&args, 0, sizeof(args));
3051 	if (info->attrs[DRBD_NLA_NEW_C_UUID_PARMS]) {
3052 		err = new_c_uuid_parms_from_attrs(&args, info);
3053 		if (err) {
3054 			retcode = ERR_MANDATORY_TAG;
3055 			drbd_msg_put_info(from_attrs_err_to_txt(err));
3056 			goto out_nolock;
3057 		}
3058 	}
3059 
3060 	mutex_lock(mdev->state_mutex); /* Protects us against serialized state changes. */
3061 
3062 	if (!get_ldev(mdev)) {
3063 		retcode = ERR_NO_DISK;
3064 		goto out;
3065 	}
3066 
3067 	/* this is "skip initial sync", assume to be clean */
3068 	if (mdev->state.conn == C_CONNECTED && mdev->tconn->agreed_pro_version >= 90 &&
3069 	    mdev->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED && args.clear_bm) {
3070 		dev_info(DEV, "Preparing to skip initial sync\n");
3071 		skip_initial_sync = 1;
3072 	} else if (mdev->state.conn != C_STANDALONE) {
3073 		retcode = ERR_CONNECTED;
3074 		goto out_dec;
3075 	}
3076 
3077 	drbd_uuid_set(mdev, UI_BITMAP, 0); /* Rotate UI_BITMAP to History 1, etc... */
3078 	drbd_uuid_new_current(mdev); /* New current, previous to UI_BITMAP */
3079 
3080 	if (args.clear_bm) {
3081 		err = drbd_bitmap_io(mdev, &drbd_bmio_clear_n_write,
3082 			"clear_n_write from new_c_uuid", BM_LOCKED_MASK);
3083 		if (err) {
3084 			dev_err(DEV, "Writing bitmap failed with %d\n",err);
3085 			retcode = ERR_IO_MD_DISK;
3086 		}
3087 		if (skip_initial_sync) {
3088 			drbd_send_uuids_skip_initial_sync(mdev);
3089 			_drbd_uuid_set(mdev, UI_BITMAP, 0);
3090 			drbd_print_uuids(mdev, "cleared bitmap UUID");
3091 			spin_lock_irq(&mdev->tconn->req_lock);
3092 			_drbd_set_state(_NS2(mdev, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
3093 					CS_VERBOSE, NULL);
3094 			spin_unlock_irq(&mdev->tconn->req_lock);
3095 		}
3096 	}
3097 
3098 	drbd_md_sync(mdev);
3099 out_dec:
3100 	put_ldev(mdev);
3101 out:
3102 	mutex_unlock(mdev->state_mutex);
3103 out_nolock:
3104 	drbd_adm_finish(info, retcode);
3105 	return 0;
3106 }
3107 
3108 static enum drbd_ret_code
3109 drbd_check_resource_name(const char *name)
3110 {
3111 	if (!name || !name[0]) {
3112 		drbd_msg_put_info("resource name missing");
3113 		return ERR_MANDATORY_TAG;
3114 	}
3115 	/* if we want to use these in sysfs/configfs/debugfs some day,
3116 	 * we must not allow slashes */
3117 	if (strchr(name, '/')) {
3118 		drbd_msg_put_info("invalid resource name");
3119 		return ERR_INVALID_REQUEST;
3120 	}
3121 	return NO_ERROR;
3122 }
3123 
3124 int drbd_adm_new_resource(struct sk_buff *skb, struct genl_info *info)
3125 {
3126 	enum drbd_ret_code retcode;
3127 	struct res_opts res_opts;
3128 	int err;
3129 
3130 	retcode = drbd_adm_prepare(skb, info, 0);
3131 	if (!adm_ctx.reply_skb)
3132 		return retcode;
3133 	if (retcode != NO_ERROR)
3134 		goto out;
3135 
3136 	set_res_opts_defaults(&res_opts);
3137 	err = res_opts_from_attrs(&res_opts, info);
3138 	if (err && err != -ENOMSG) {
3139 		retcode = ERR_MANDATORY_TAG;
3140 		drbd_msg_put_info(from_attrs_err_to_txt(err));
3141 		goto out;
3142 	}
3143 
3144 	retcode = drbd_check_resource_name(adm_ctx.resource_name);
3145 	if (retcode != NO_ERROR)
3146 		goto out;
3147 
3148 	if (adm_ctx.tconn) {
3149 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) {
3150 			retcode = ERR_INVALID_REQUEST;
3151 			drbd_msg_put_info("resource exists");
3152 		}
3153 		/* else: still NO_ERROR */
3154 		goto out;
3155 	}
3156 
3157 	if (!conn_create(adm_ctx.resource_name, &res_opts))
3158 		retcode = ERR_NOMEM;
3159 out:
3160 	drbd_adm_finish(info, retcode);
3161 	return 0;
3162 }
3163 
3164 int drbd_adm_add_minor(struct sk_buff *skb, struct genl_info *info)
3165 {
3166 	struct drbd_genlmsghdr *dh = info->userhdr;
3167 	enum drbd_ret_code retcode;
3168 
3169 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_RESOURCE);
3170 	if (!adm_ctx.reply_skb)
3171 		return retcode;
3172 	if (retcode != NO_ERROR)
3173 		goto out;
3174 
3175 	if (dh->minor > MINORMASK) {
3176 		drbd_msg_put_info("requested minor out of range");
3177 		retcode = ERR_INVALID_REQUEST;
3178 		goto out;
3179 	}
3180 	if (adm_ctx.volume > DRBD_VOLUME_MAX) {
3181 		drbd_msg_put_info("requested volume id out of range");
3182 		retcode = ERR_INVALID_REQUEST;
3183 		goto out;
3184 	}
3185 
3186 	/* drbd_adm_prepare made sure already
3187 	 * that mdev->tconn and mdev->vnr match the request. */
3188 	if (adm_ctx.mdev) {
3189 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
3190 			retcode = ERR_MINOR_EXISTS;
3191 		/* else: still NO_ERROR */
3192 		goto out;
3193 	}
3194 
3195 	retcode = conn_new_minor(adm_ctx.tconn, dh->minor, adm_ctx.volume);
3196 out:
3197 	drbd_adm_finish(info, retcode);
3198 	return 0;
3199 }
3200 
3201 static enum drbd_ret_code adm_delete_minor(struct drbd_conf *mdev)
3202 {
3203 	if (mdev->state.disk == D_DISKLESS &&
3204 	    /* no need to be mdev->state.conn == C_STANDALONE &&
3205 	     * we may want to delete a minor from a live replication group.
3206 	     */
3207 	    mdev->state.role == R_SECONDARY) {
3208 		_drbd_request_state(mdev, NS(conn, C_WF_REPORT_PARAMS),
3209 				    CS_VERBOSE + CS_WAIT_COMPLETE);
3210 		idr_remove(&mdev->tconn->volumes, mdev->vnr);
3211 		idr_remove(&minors, mdev_to_minor(mdev));
3212 		destroy_workqueue(mdev->submit.wq);
3213 		del_gendisk(mdev->vdisk);
3214 		synchronize_rcu();
3215 		kref_put(&mdev->kref, &drbd_minor_destroy);
3216 		return NO_ERROR;
3217 	} else
3218 		return ERR_MINOR_CONFIGURED;
3219 }
3220 
3221 int drbd_adm_delete_minor(struct sk_buff *skb, struct genl_info *info)
3222 {
3223 	enum drbd_ret_code retcode;
3224 
3225 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
3226 	if (!adm_ctx.reply_skb)
3227 		return retcode;
3228 	if (retcode != NO_ERROR)
3229 		goto out;
3230 
3231 	retcode = adm_delete_minor(adm_ctx.mdev);
3232 out:
3233 	drbd_adm_finish(info, retcode);
3234 	return 0;
3235 }
3236 
3237 int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
3238 {
3239 	int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
3240 	struct drbd_conf *mdev;
3241 	unsigned i;
3242 
3243 	retcode = drbd_adm_prepare(skb, info, 0);
3244 	if (!adm_ctx.reply_skb)
3245 		return retcode;
3246 	if (retcode != NO_ERROR)
3247 		goto out;
3248 
3249 	if (!adm_ctx.tconn) {
3250 		retcode = ERR_RES_NOT_KNOWN;
3251 		goto out;
3252 	}
3253 
3254 	/* demote */
3255 	idr_for_each_entry(&adm_ctx.tconn->volumes, mdev, i) {
3256 		retcode = drbd_set_role(mdev, R_SECONDARY, 0);
3257 		if (retcode < SS_SUCCESS) {
3258 			drbd_msg_put_info("failed to demote");
3259 			goto out;
3260 		}
3261 	}
3262 
3263 	retcode = conn_try_disconnect(adm_ctx.tconn, 0);
3264 	if (retcode < SS_SUCCESS) {
3265 		drbd_msg_put_info("failed to disconnect");
3266 		goto out;
3267 	}
3268 
3269 	/* detach */
3270 	idr_for_each_entry(&adm_ctx.tconn->volumes, mdev, i) {
3271 		retcode = adm_detach(mdev, 0);
3272 		if (retcode < SS_SUCCESS || retcode > NO_ERROR) {
3273 			drbd_msg_put_info("failed to detach");
3274 			goto out;
3275 		}
3276 	}
3277 
3278 	/* If we reach this, all volumes (of this tconn) are Secondary,
3279 	 * Disconnected, Diskless, aka Unconfigured. Make sure all threads have
3280 	 * actually stopped, state handling only does drbd_thread_stop_nowait(). */
3281 	drbd_thread_stop(&adm_ctx.tconn->worker);
3282 
3283 	/* Now, nothing can fail anymore */
3284 
3285 	/* delete volumes */
3286 	idr_for_each_entry(&adm_ctx.tconn->volumes, mdev, i) {
3287 		retcode = adm_delete_minor(mdev);
3288 		if (retcode != NO_ERROR) {
3289 			/* "can not happen" */
3290 			drbd_msg_put_info("failed to delete volume");
3291 			goto out;
3292 		}
3293 	}
3294 
3295 	/* delete connection */
3296 	if (conn_lowest_minor(adm_ctx.tconn) < 0) {
3297 		list_del_rcu(&adm_ctx.tconn->all_tconn);
3298 		synchronize_rcu();
3299 		kref_put(&adm_ctx.tconn->kref, &conn_destroy);
3300 
3301 		retcode = NO_ERROR;
3302 	} else {
3303 		/* "can not happen" */
3304 		retcode = ERR_RES_IN_USE;
3305 		drbd_msg_put_info("failed to delete connection");
3306 	}
3307 	goto out;
3308 out:
3309 	drbd_adm_finish(info, retcode);
3310 	return 0;
3311 }
3312 
3313 int drbd_adm_del_resource(struct sk_buff *skb, struct genl_info *info)
3314 {
3315 	enum drbd_ret_code retcode;
3316 
3317 	retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_RESOURCE);
3318 	if (!adm_ctx.reply_skb)
3319 		return retcode;
3320 	if (retcode != NO_ERROR)
3321 		goto out;
3322 
3323 	if (conn_lowest_minor(adm_ctx.tconn) < 0) {
3324 		list_del_rcu(&adm_ctx.tconn->all_tconn);
3325 		synchronize_rcu();
3326 		kref_put(&adm_ctx.tconn->kref, &conn_destroy);
3327 
3328 		retcode = NO_ERROR;
3329 	} else {
3330 		retcode = ERR_RES_IN_USE;
3331 	}
3332 
3333 	if (retcode == NO_ERROR)
3334 		drbd_thread_stop(&adm_ctx.tconn->worker);
3335 out:
3336 	drbd_adm_finish(info, retcode);
3337 	return 0;
3338 }
3339 
3340 void drbd_bcast_event(struct drbd_conf *mdev, const struct sib_info *sib)
3341 {
3342 	static atomic_t drbd_genl_seq = ATOMIC_INIT(2); /* two. */
3343 	struct sk_buff *msg;
3344 	struct drbd_genlmsghdr *d_out;
3345 	unsigned seq;
3346 	int err = -ENOMEM;
3347 
3348 	if (sib->sib_reason == SIB_SYNC_PROGRESS) {
3349 		if (time_after(jiffies, mdev->rs_last_bcast + HZ))
3350 			mdev->rs_last_bcast = jiffies;
3351 		else
3352 			return;
3353 	}
3354 
3355 	seq = atomic_inc_return(&drbd_genl_seq);
3356 	msg = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
3357 	if (!msg)
3358 		goto failed;
3359 
3360 	err = -EMSGSIZE;
3361 	d_out = genlmsg_put(msg, 0, seq, &drbd_genl_family, 0, DRBD_EVENT);
3362 	if (!d_out) /* cannot happen, but anyways. */
3363 		goto nla_put_failure;
3364 	d_out->minor = mdev_to_minor(mdev);
3365 	d_out->ret_code = NO_ERROR;
3366 
3367 	if (nla_put_status_info(msg, mdev, sib))
3368 		goto nla_put_failure;
3369 	genlmsg_end(msg, d_out);
3370 	err = drbd_genl_multicast_events(msg, 0);
3371 	/* msg has been consumed or freed in netlink_broadcast() */
3372 	if (err && err != -ESRCH)
3373 		goto failed;
3374 
3375 	return;
3376 
3377 nla_put_failure:
3378 	nlmsg_free(msg);
3379 failed:
3380 	dev_err(DEV, "Error %d while broadcasting event. "
3381 			"Event seq:%u sib_reason:%u\n",
3382 			err, seq, sib->sib_reason);
3383 }
3384