xref: /linux/drivers/block/drbd/drbd_nl.c (revision a67f7a0b18c09d5b62eafb6d5c2f54e6f6ea6cf1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3    drbd_nl.c
4 
5    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
6 
7    Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
8    Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
9    Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
10 
11 
12  */
13 
14 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
15 
16 #include <linux/module.h>
17 #include <linux/drbd.h>
18 #include <linux/in.h>
19 #include <linux/fs.h>
20 #include <linux/file.h>
21 #include <linux/slab.h>
22 #include <linux/blkpg.h>
23 #include <linux/cpumask.h>
24 #include "drbd_int.h"
25 #include "drbd_protocol.h"
26 #include "drbd_req.h"
27 #include "drbd_state_change.h"
28 #include <asm/unaligned.h>
29 #include <linux/drbd_limits.h>
30 #include <linux/kthread.h>
31 
32 #include <net/genetlink.h>
33 
34 /* .doit */
35 // int drbd_adm_create_resource(struct sk_buff *skb, struct genl_info *info);
36 // int drbd_adm_delete_resource(struct sk_buff *skb, struct genl_info *info);
37 
38 int drbd_adm_new_minor(struct sk_buff *skb, struct genl_info *info);
39 int drbd_adm_del_minor(struct sk_buff *skb, struct genl_info *info);
40 
41 int drbd_adm_new_resource(struct sk_buff *skb, struct genl_info *info);
42 int drbd_adm_del_resource(struct sk_buff *skb, struct genl_info *info);
43 int drbd_adm_down(struct sk_buff *skb, struct genl_info *info);
44 
45 int drbd_adm_set_role(struct sk_buff *skb, struct genl_info *info);
46 int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info);
47 int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info);
48 int drbd_adm_detach(struct sk_buff *skb, struct genl_info *info);
49 int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info);
50 int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info);
51 int drbd_adm_resize(struct sk_buff *skb, struct genl_info *info);
52 int drbd_adm_start_ov(struct sk_buff *skb, struct genl_info *info);
53 int drbd_adm_new_c_uuid(struct sk_buff *skb, struct genl_info *info);
54 int drbd_adm_disconnect(struct sk_buff *skb, struct genl_info *info);
55 int drbd_adm_invalidate(struct sk_buff *skb, struct genl_info *info);
56 int drbd_adm_invalidate_peer(struct sk_buff *skb, struct genl_info *info);
57 int drbd_adm_pause_sync(struct sk_buff *skb, struct genl_info *info);
58 int drbd_adm_resume_sync(struct sk_buff *skb, struct genl_info *info);
59 int drbd_adm_suspend_io(struct sk_buff *skb, struct genl_info *info);
60 int drbd_adm_resume_io(struct sk_buff *skb, struct genl_info *info);
61 int drbd_adm_outdate(struct sk_buff *skb, struct genl_info *info);
62 int drbd_adm_resource_opts(struct sk_buff *skb, struct genl_info *info);
63 int drbd_adm_get_status(struct sk_buff *skb, struct genl_info *info);
64 int drbd_adm_get_timeout_type(struct sk_buff *skb, struct genl_info *info);
65 /* .dumpit */
66 int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb);
67 int drbd_adm_dump_resources(struct sk_buff *skb, struct netlink_callback *cb);
68 int drbd_adm_dump_devices(struct sk_buff *skb, struct netlink_callback *cb);
69 int drbd_adm_dump_devices_done(struct netlink_callback *cb);
70 int drbd_adm_dump_connections(struct sk_buff *skb, struct netlink_callback *cb);
71 int drbd_adm_dump_connections_done(struct netlink_callback *cb);
72 int drbd_adm_dump_peer_devices(struct sk_buff *skb, struct netlink_callback *cb);
73 int drbd_adm_dump_peer_devices_done(struct netlink_callback *cb);
74 int drbd_adm_get_initial_state(struct sk_buff *skb, struct netlink_callback *cb);
75 
76 #include <linux/drbd_genl_api.h>
77 #include "drbd_nla.h"
78 #include <linux/genl_magic_func.h>
79 
80 static atomic_t drbd_genl_seq = ATOMIC_INIT(2); /* two. */
81 static atomic_t notify_genl_seq = ATOMIC_INIT(2); /* two. */
82 
83 DEFINE_MUTEX(notification_mutex);
84 
85 /* used blkdev_get_by_path, to claim our meta data device(s) */
86 static char *drbd_m_holder = "Hands off! this is DRBD's meta data device.";
87 
88 static void drbd_adm_send_reply(struct sk_buff *skb, struct genl_info *info)
89 {
90 	genlmsg_end(skb, genlmsg_data(nlmsg_data(nlmsg_hdr(skb))));
91 	if (genlmsg_reply(skb, info))
92 		pr_err("error sending genl reply\n");
93 }
94 
95 /* Used on a fresh "drbd_adm_prepare"d reply_skb, this cannot fail: The only
96  * reason it could fail was no space in skb, and there are 4k available. */
97 static int drbd_msg_put_info(struct sk_buff *skb, const char *info)
98 {
99 	struct nlattr *nla;
100 	int err = -EMSGSIZE;
101 
102 	if (!info || !info[0])
103 		return 0;
104 
105 	nla = nla_nest_start_noflag(skb, DRBD_NLA_CFG_REPLY);
106 	if (!nla)
107 		return err;
108 
109 	err = nla_put_string(skb, T_info_text, info);
110 	if (err) {
111 		nla_nest_cancel(skb, nla);
112 		return err;
113 	} else
114 		nla_nest_end(skb, nla);
115 	return 0;
116 }
117 
118 __printf(2, 3)
119 static int drbd_msg_sprintf_info(struct sk_buff *skb, const char *fmt, ...)
120 {
121 	va_list args;
122 	struct nlattr *nla, *txt;
123 	int err = -EMSGSIZE;
124 	int len;
125 
126 	nla = nla_nest_start_noflag(skb, DRBD_NLA_CFG_REPLY);
127 	if (!nla)
128 		return err;
129 
130 	txt = nla_reserve(skb, T_info_text, 256);
131 	if (!txt) {
132 		nla_nest_cancel(skb, nla);
133 		return err;
134 	}
135 	va_start(args, fmt);
136 	len = vscnprintf(nla_data(txt), 256, fmt, args);
137 	va_end(args);
138 
139 	/* maybe: retry with larger reserve, if truncated */
140 	txt->nla_len = nla_attr_size(len+1);
141 	nlmsg_trim(skb, (char*)txt + NLA_ALIGN(txt->nla_len));
142 	nla_nest_end(skb, nla);
143 
144 	return 0;
145 }
146 
147 /* This would be a good candidate for a "pre_doit" hook,
148  * and per-family private info->pointers.
149  * But we need to stay compatible with older kernels.
150  * If it returns successfully, adm_ctx members are valid.
151  *
152  * At this point, we still rely on the global genl_lock().
153  * If we want to avoid that, and allow "genl_family.parallel_ops", we may need
154  * to add additional synchronization against object destruction/modification.
155  */
156 #define DRBD_ADM_NEED_MINOR	1
157 #define DRBD_ADM_NEED_RESOURCE	2
158 #define DRBD_ADM_NEED_CONNECTION 4
159 static int drbd_adm_prepare(struct drbd_config_context *adm_ctx,
160 	struct sk_buff *skb, struct genl_info *info, unsigned flags)
161 {
162 	struct drbd_genlmsghdr *d_in = genl_info_userhdr(info);
163 	const u8 cmd = info->genlhdr->cmd;
164 	int err;
165 
166 	memset(adm_ctx, 0, sizeof(*adm_ctx));
167 
168 	/* genl_rcv_msg only checks for CAP_NET_ADMIN on "GENL_ADMIN_PERM" :( */
169 	if (cmd != DRBD_ADM_GET_STATUS && !capable(CAP_NET_ADMIN))
170 	       return -EPERM;
171 
172 	adm_ctx->reply_skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
173 	if (!adm_ctx->reply_skb) {
174 		err = -ENOMEM;
175 		goto fail;
176 	}
177 
178 	adm_ctx->reply_dh = genlmsg_put_reply(adm_ctx->reply_skb,
179 					info, &drbd_genl_family, 0, cmd);
180 	/* put of a few bytes into a fresh skb of >= 4k will always succeed.
181 	 * but anyways */
182 	if (!adm_ctx->reply_dh) {
183 		err = -ENOMEM;
184 		goto fail;
185 	}
186 
187 	adm_ctx->reply_dh->minor = d_in->minor;
188 	adm_ctx->reply_dh->ret_code = NO_ERROR;
189 
190 	adm_ctx->volume = VOLUME_UNSPECIFIED;
191 	if (info->attrs[DRBD_NLA_CFG_CONTEXT]) {
192 		struct nlattr *nla;
193 		/* parse and validate only */
194 		err = drbd_cfg_context_from_attrs(NULL, info);
195 		if (err)
196 			goto fail;
197 
198 		/* It was present, and valid,
199 		 * copy it over to the reply skb. */
200 		err = nla_put_nohdr(adm_ctx->reply_skb,
201 				info->attrs[DRBD_NLA_CFG_CONTEXT]->nla_len,
202 				info->attrs[DRBD_NLA_CFG_CONTEXT]);
203 		if (err)
204 			goto fail;
205 
206 		/* and assign stuff to the adm_ctx */
207 		nla = nested_attr_tb[__nla_type(T_ctx_volume)];
208 		if (nla)
209 			adm_ctx->volume = nla_get_u32(nla);
210 		nla = nested_attr_tb[__nla_type(T_ctx_resource_name)];
211 		if (nla)
212 			adm_ctx->resource_name = nla_data(nla);
213 		adm_ctx->my_addr = nested_attr_tb[__nla_type(T_ctx_my_addr)];
214 		adm_ctx->peer_addr = nested_attr_tb[__nla_type(T_ctx_peer_addr)];
215 		if ((adm_ctx->my_addr &&
216 		     nla_len(adm_ctx->my_addr) > sizeof(adm_ctx->connection->my_addr)) ||
217 		    (adm_ctx->peer_addr &&
218 		     nla_len(adm_ctx->peer_addr) > sizeof(adm_ctx->connection->peer_addr))) {
219 			err = -EINVAL;
220 			goto fail;
221 		}
222 	}
223 
224 	adm_ctx->minor = d_in->minor;
225 	adm_ctx->device = minor_to_device(d_in->minor);
226 
227 	/* We are protected by the global genl_lock().
228 	 * But we may explicitly drop it/retake it in drbd_adm_set_role(),
229 	 * so make sure this object stays around. */
230 	if (adm_ctx->device)
231 		kref_get(&adm_ctx->device->kref);
232 
233 	if (adm_ctx->resource_name) {
234 		adm_ctx->resource = drbd_find_resource(adm_ctx->resource_name);
235 	}
236 
237 	if (!adm_ctx->device && (flags & DRBD_ADM_NEED_MINOR)) {
238 		drbd_msg_put_info(adm_ctx->reply_skb, "unknown minor");
239 		return ERR_MINOR_INVALID;
240 	}
241 	if (!adm_ctx->resource && (flags & DRBD_ADM_NEED_RESOURCE)) {
242 		drbd_msg_put_info(adm_ctx->reply_skb, "unknown resource");
243 		if (adm_ctx->resource_name)
244 			return ERR_RES_NOT_KNOWN;
245 		return ERR_INVALID_REQUEST;
246 	}
247 
248 	if (flags & DRBD_ADM_NEED_CONNECTION) {
249 		if (adm_ctx->resource) {
250 			drbd_msg_put_info(adm_ctx->reply_skb, "no resource name expected");
251 			return ERR_INVALID_REQUEST;
252 		}
253 		if (adm_ctx->device) {
254 			drbd_msg_put_info(adm_ctx->reply_skb, "no minor number expected");
255 			return ERR_INVALID_REQUEST;
256 		}
257 		if (adm_ctx->my_addr && adm_ctx->peer_addr)
258 			adm_ctx->connection = conn_get_by_addrs(nla_data(adm_ctx->my_addr),
259 							  nla_len(adm_ctx->my_addr),
260 							  nla_data(adm_ctx->peer_addr),
261 							  nla_len(adm_ctx->peer_addr));
262 		if (!adm_ctx->connection) {
263 			drbd_msg_put_info(adm_ctx->reply_skb, "unknown connection");
264 			return ERR_INVALID_REQUEST;
265 		}
266 	}
267 
268 	/* some more paranoia, if the request was over-determined */
269 	if (adm_ctx->device && adm_ctx->resource &&
270 	    adm_ctx->device->resource != adm_ctx->resource) {
271 		pr_warn("request: minor=%u, resource=%s; but that minor belongs to resource %s\n",
272 			adm_ctx->minor, adm_ctx->resource->name,
273 			adm_ctx->device->resource->name);
274 		drbd_msg_put_info(adm_ctx->reply_skb, "minor exists in different resource");
275 		return ERR_INVALID_REQUEST;
276 	}
277 	if (adm_ctx->device &&
278 	    adm_ctx->volume != VOLUME_UNSPECIFIED &&
279 	    adm_ctx->volume != adm_ctx->device->vnr) {
280 		pr_warn("request: minor=%u, volume=%u; but that minor is volume %u in %s\n",
281 			adm_ctx->minor, adm_ctx->volume,
282 			adm_ctx->device->vnr, adm_ctx->device->resource->name);
283 		drbd_msg_put_info(adm_ctx->reply_skb, "minor exists as different volume");
284 		return ERR_INVALID_REQUEST;
285 	}
286 
287 	/* still, provide adm_ctx->resource always, if possible. */
288 	if (!adm_ctx->resource) {
289 		adm_ctx->resource = adm_ctx->device ? adm_ctx->device->resource
290 			: adm_ctx->connection ? adm_ctx->connection->resource : NULL;
291 		if (adm_ctx->resource)
292 			kref_get(&adm_ctx->resource->kref);
293 	}
294 
295 	return NO_ERROR;
296 
297 fail:
298 	nlmsg_free(adm_ctx->reply_skb);
299 	adm_ctx->reply_skb = NULL;
300 	return err;
301 }
302 
303 static int drbd_adm_finish(struct drbd_config_context *adm_ctx,
304 	struct genl_info *info, int retcode)
305 {
306 	if (adm_ctx->device) {
307 		kref_put(&adm_ctx->device->kref, drbd_destroy_device);
308 		adm_ctx->device = NULL;
309 	}
310 	if (adm_ctx->connection) {
311 		kref_put(&adm_ctx->connection->kref, &drbd_destroy_connection);
312 		adm_ctx->connection = NULL;
313 	}
314 	if (adm_ctx->resource) {
315 		kref_put(&adm_ctx->resource->kref, drbd_destroy_resource);
316 		adm_ctx->resource = NULL;
317 	}
318 
319 	if (!adm_ctx->reply_skb)
320 		return -ENOMEM;
321 
322 	adm_ctx->reply_dh->ret_code = retcode;
323 	drbd_adm_send_reply(adm_ctx->reply_skb, info);
324 	return 0;
325 }
326 
327 static void setup_khelper_env(struct drbd_connection *connection, char **envp)
328 {
329 	char *afs;
330 
331 	/* FIXME: A future version will not allow this case. */
332 	if (connection->my_addr_len == 0 || connection->peer_addr_len == 0)
333 		return;
334 
335 	switch (((struct sockaddr *)&connection->peer_addr)->sa_family) {
336 	case AF_INET6:
337 		afs = "ipv6";
338 		snprintf(envp[4], 60, "DRBD_PEER_ADDRESS=%pI6",
339 			 &((struct sockaddr_in6 *)&connection->peer_addr)->sin6_addr);
340 		break;
341 	case AF_INET:
342 		afs = "ipv4";
343 		snprintf(envp[4], 60, "DRBD_PEER_ADDRESS=%pI4",
344 			 &((struct sockaddr_in *)&connection->peer_addr)->sin_addr);
345 		break;
346 	default:
347 		afs = "ssocks";
348 		snprintf(envp[4], 60, "DRBD_PEER_ADDRESS=%pI4",
349 			 &((struct sockaddr_in *)&connection->peer_addr)->sin_addr);
350 	}
351 	snprintf(envp[3], 20, "DRBD_PEER_AF=%s", afs);
352 }
353 
354 int drbd_khelper(struct drbd_device *device, char *cmd)
355 {
356 	char *envp[] = { "HOME=/",
357 			"TERM=linux",
358 			"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
359 			 (char[20]) { }, /* address family */
360 			 (char[60]) { }, /* address */
361 			NULL };
362 	char mb[14];
363 	char *argv[] = {drbd_usermode_helper, cmd, mb, NULL };
364 	struct drbd_connection *connection = first_peer_device(device)->connection;
365 	struct sib_info sib;
366 	int ret;
367 
368 	if (current == connection->worker.task)
369 		set_bit(CALLBACK_PENDING, &connection->flags);
370 
371 	snprintf(mb, 14, "minor-%d", device_to_minor(device));
372 	setup_khelper_env(connection, envp);
373 
374 	/* The helper may take some time.
375 	 * write out any unsynced meta data changes now */
376 	drbd_md_sync(device);
377 
378 	drbd_info(device, "helper command: %s %s %s\n", drbd_usermode_helper, cmd, mb);
379 	sib.sib_reason = SIB_HELPER_PRE;
380 	sib.helper_name = cmd;
381 	drbd_bcast_event(device, &sib);
382 	notify_helper(NOTIFY_CALL, device, connection, cmd, 0);
383 	ret = call_usermodehelper(drbd_usermode_helper, argv, envp, UMH_WAIT_PROC);
384 	if (ret)
385 		drbd_warn(device, "helper command: %s %s %s exit code %u (0x%x)\n",
386 				drbd_usermode_helper, cmd, mb,
387 				(ret >> 8) & 0xff, ret);
388 	else
389 		drbd_info(device, "helper command: %s %s %s exit code %u (0x%x)\n",
390 				drbd_usermode_helper, cmd, mb,
391 				(ret >> 8) & 0xff, ret);
392 	sib.sib_reason = SIB_HELPER_POST;
393 	sib.helper_exit_code = ret;
394 	drbd_bcast_event(device, &sib);
395 	notify_helper(NOTIFY_RESPONSE, device, connection, cmd, ret);
396 
397 	if (current == connection->worker.task)
398 		clear_bit(CALLBACK_PENDING, &connection->flags);
399 
400 	if (ret < 0) /* Ignore any ERRNOs we got. */
401 		ret = 0;
402 
403 	return ret;
404 }
405 
406 enum drbd_peer_state conn_khelper(struct drbd_connection *connection, char *cmd)
407 {
408 	char *envp[] = { "HOME=/",
409 			"TERM=linux",
410 			"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
411 			 (char[20]) { }, /* address family */
412 			 (char[60]) { }, /* address */
413 			NULL };
414 	char *resource_name = connection->resource->name;
415 	char *argv[] = {drbd_usermode_helper, cmd, resource_name, NULL };
416 	int ret;
417 
418 	setup_khelper_env(connection, envp);
419 	conn_md_sync(connection);
420 
421 	drbd_info(connection, "helper command: %s %s %s\n", drbd_usermode_helper, cmd, resource_name);
422 	/* TODO: conn_bcast_event() ?? */
423 	notify_helper(NOTIFY_CALL, NULL, connection, cmd, 0);
424 
425 	ret = call_usermodehelper(drbd_usermode_helper, argv, envp, UMH_WAIT_PROC);
426 	if (ret)
427 		drbd_warn(connection, "helper command: %s %s %s exit code %u (0x%x)\n",
428 			  drbd_usermode_helper, cmd, resource_name,
429 			  (ret >> 8) & 0xff, ret);
430 	else
431 		drbd_info(connection, "helper command: %s %s %s exit code %u (0x%x)\n",
432 			  drbd_usermode_helper, cmd, resource_name,
433 			  (ret >> 8) & 0xff, ret);
434 	/* TODO: conn_bcast_event() ?? */
435 	notify_helper(NOTIFY_RESPONSE, NULL, connection, cmd, ret);
436 
437 	if (ret < 0) /* Ignore any ERRNOs we got. */
438 		ret = 0;
439 
440 	return ret;
441 }
442 
443 static enum drbd_fencing_p highest_fencing_policy(struct drbd_connection *connection)
444 {
445 	enum drbd_fencing_p fp = FP_NOT_AVAIL;
446 	struct drbd_peer_device *peer_device;
447 	int vnr;
448 
449 	rcu_read_lock();
450 	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
451 		struct drbd_device *device = peer_device->device;
452 		if (get_ldev_if_state(device, D_CONSISTENT)) {
453 			struct disk_conf *disk_conf =
454 				rcu_dereference(peer_device->device->ldev->disk_conf);
455 			fp = max_t(enum drbd_fencing_p, fp, disk_conf->fencing);
456 			put_ldev(device);
457 		}
458 	}
459 	rcu_read_unlock();
460 
461 	return fp;
462 }
463 
464 static bool resource_is_supended(struct drbd_resource *resource)
465 {
466 	return resource->susp || resource->susp_fen || resource->susp_nod;
467 }
468 
469 bool conn_try_outdate_peer(struct drbd_connection *connection)
470 {
471 	struct drbd_resource * const resource = connection->resource;
472 	unsigned int connect_cnt;
473 	union drbd_state mask = { };
474 	union drbd_state val = { };
475 	enum drbd_fencing_p fp;
476 	char *ex_to_string;
477 	int r;
478 
479 	spin_lock_irq(&resource->req_lock);
480 	if (connection->cstate >= C_WF_REPORT_PARAMS) {
481 		drbd_err(connection, "Expected cstate < C_WF_REPORT_PARAMS\n");
482 		spin_unlock_irq(&resource->req_lock);
483 		return false;
484 	}
485 
486 	connect_cnt = connection->connect_cnt;
487 	spin_unlock_irq(&resource->req_lock);
488 
489 	fp = highest_fencing_policy(connection);
490 	switch (fp) {
491 	case FP_NOT_AVAIL:
492 		drbd_warn(connection, "Not fencing peer, I'm not even Consistent myself.\n");
493 		spin_lock_irq(&resource->req_lock);
494 		if (connection->cstate < C_WF_REPORT_PARAMS) {
495 			_conn_request_state(connection,
496 					    (union drbd_state) { { .susp_fen = 1 } },
497 					    (union drbd_state) { { .susp_fen = 0 } },
498 					    CS_VERBOSE | CS_HARD | CS_DC_SUSP);
499 			/* We are no longer suspended due to the fencing policy.
500 			 * We may still be suspended due to the on-no-data-accessible policy.
501 			 * If that was OND_IO_ERROR, fail pending requests. */
502 			if (!resource_is_supended(resource))
503 				_tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
504 		}
505 		/* Else: in case we raced with a connection handshake,
506 		 * let the handshake figure out if we maybe can RESEND,
507 		 * and do not resume/fail pending requests here.
508 		 * Worst case is we stay suspended for now, which may be
509 		 * resolved by either re-establishing the replication link, or
510 		 * the next link failure, or eventually the administrator.  */
511 		spin_unlock_irq(&resource->req_lock);
512 		return false;
513 
514 	case FP_DONT_CARE:
515 		return true;
516 	default: ;
517 	}
518 
519 	r = conn_khelper(connection, "fence-peer");
520 
521 	switch ((r>>8) & 0xff) {
522 	case P_INCONSISTENT: /* peer is inconsistent */
523 		ex_to_string = "peer is inconsistent or worse";
524 		mask.pdsk = D_MASK;
525 		val.pdsk = D_INCONSISTENT;
526 		break;
527 	case P_OUTDATED: /* peer got outdated, or was already outdated */
528 		ex_to_string = "peer was fenced";
529 		mask.pdsk = D_MASK;
530 		val.pdsk = D_OUTDATED;
531 		break;
532 	case P_DOWN: /* peer was down */
533 		if (conn_highest_disk(connection) == D_UP_TO_DATE) {
534 			/* we will(have) create(d) a new UUID anyways... */
535 			ex_to_string = "peer is unreachable, assumed to be dead";
536 			mask.pdsk = D_MASK;
537 			val.pdsk = D_OUTDATED;
538 		} else {
539 			ex_to_string = "peer unreachable, doing nothing since disk != UpToDate";
540 		}
541 		break;
542 	case P_PRIMARY: /* Peer is primary, voluntarily outdate myself.
543 		 * This is useful when an unconnected R_SECONDARY is asked to
544 		 * become R_PRIMARY, but finds the other peer being active. */
545 		ex_to_string = "peer is active";
546 		drbd_warn(connection, "Peer is primary, outdating myself.\n");
547 		mask.disk = D_MASK;
548 		val.disk = D_OUTDATED;
549 		break;
550 	case P_FENCING:
551 		/* THINK: do we need to handle this
552 		 * like case 4, or more like case 5? */
553 		if (fp != FP_STONITH)
554 			drbd_err(connection, "fence-peer() = 7 && fencing != Stonith !!!\n");
555 		ex_to_string = "peer was stonithed";
556 		mask.pdsk = D_MASK;
557 		val.pdsk = D_OUTDATED;
558 		break;
559 	default:
560 		/* The script is broken ... */
561 		drbd_err(connection, "fence-peer helper broken, returned %d\n", (r>>8)&0xff);
562 		return false; /* Eventually leave IO frozen */
563 	}
564 
565 	drbd_info(connection, "fence-peer helper returned %d (%s)\n",
566 		  (r>>8) & 0xff, ex_to_string);
567 
568 	/* Not using
569 	   conn_request_state(connection, mask, val, CS_VERBOSE);
570 	   here, because we might were able to re-establish the connection in the
571 	   meantime. */
572 	spin_lock_irq(&resource->req_lock);
573 	if (connection->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &connection->flags)) {
574 		if (connection->connect_cnt != connect_cnt)
575 			/* In case the connection was established and droped
576 			   while the fence-peer handler was running, ignore it */
577 			drbd_info(connection, "Ignoring fence-peer exit code\n");
578 		else
579 			_conn_request_state(connection, mask, val, CS_VERBOSE);
580 	}
581 	spin_unlock_irq(&resource->req_lock);
582 
583 	return conn_highest_pdsk(connection) <= D_OUTDATED;
584 }
585 
586 static int _try_outdate_peer_async(void *data)
587 {
588 	struct drbd_connection *connection = (struct drbd_connection *)data;
589 
590 	conn_try_outdate_peer(connection);
591 
592 	kref_put(&connection->kref, drbd_destroy_connection);
593 	return 0;
594 }
595 
596 void conn_try_outdate_peer_async(struct drbd_connection *connection)
597 {
598 	struct task_struct *opa;
599 
600 	kref_get(&connection->kref);
601 	/* We may have just sent a signal to this thread
602 	 * to get it out of some blocking network function.
603 	 * Clear signals; otherwise kthread_run(), which internally uses
604 	 * wait_on_completion_killable(), will mistake our pending signal
605 	 * for a new fatal signal and fail. */
606 	flush_signals(current);
607 	opa = kthread_run(_try_outdate_peer_async, connection, "drbd_async_h");
608 	if (IS_ERR(opa)) {
609 		drbd_err(connection, "out of mem, failed to invoke fence-peer helper\n");
610 		kref_put(&connection->kref, drbd_destroy_connection);
611 	}
612 }
613 
614 enum drbd_state_rv
615 drbd_set_role(struct drbd_device *const device, enum drbd_role new_role, int force)
616 {
617 	struct drbd_peer_device *const peer_device = first_peer_device(device);
618 	struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL;
619 	const int max_tries = 4;
620 	enum drbd_state_rv rv = SS_UNKNOWN_ERROR;
621 	struct net_conf *nc;
622 	int try = 0;
623 	int forced = 0;
624 	union drbd_state mask, val;
625 
626 	if (new_role == R_PRIMARY) {
627 		struct drbd_connection *connection;
628 
629 		/* Detect dead peers as soon as possible.  */
630 
631 		rcu_read_lock();
632 		for_each_connection(connection, device->resource)
633 			request_ping(connection);
634 		rcu_read_unlock();
635 	}
636 
637 	mutex_lock(device->state_mutex);
638 
639 	mask.i = 0; mask.role = R_MASK;
640 	val.i  = 0; val.role  = new_role;
641 
642 	while (try++ < max_tries) {
643 		rv = _drbd_request_state_holding_state_mutex(device, mask, val, CS_WAIT_COMPLETE);
644 
645 		/* in case we first succeeded to outdate,
646 		 * but now suddenly could establish a connection */
647 		if (rv == SS_CW_FAILED_BY_PEER && mask.pdsk != 0) {
648 			val.pdsk = 0;
649 			mask.pdsk = 0;
650 			continue;
651 		}
652 
653 		if (rv == SS_NO_UP_TO_DATE_DISK && force &&
654 		    (device->state.disk < D_UP_TO_DATE &&
655 		     device->state.disk >= D_INCONSISTENT)) {
656 			mask.disk = D_MASK;
657 			val.disk  = D_UP_TO_DATE;
658 			forced = 1;
659 			continue;
660 		}
661 
662 		if (rv == SS_NO_UP_TO_DATE_DISK &&
663 		    device->state.disk == D_CONSISTENT && mask.pdsk == 0) {
664 			D_ASSERT(device, device->state.pdsk == D_UNKNOWN);
665 
666 			if (conn_try_outdate_peer(connection)) {
667 				val.disk = D_UP_TO_DATE;
668 				mask.disk = D_MASK;
669 			}
670 			continue;
671 		}
672 
673 		if (rv == SS_NOTHING_TO_DO)
674 			goto out;
675 		if (rv == SS_PRIMARY_NOP && mask.pdsk == 0) {
676 			if (!conn_try_outdate_peer(connection) && force) {
677 				drbd_warn(device, "Forced into split brain situation!\n");
678 				mask.pdsk = D_MASK;
679 				val.pdsk  = D_OUTDATED;
680 
681 			}
682 			continue;
683 		}
684 		if (rv == SS_TWO_PRIMARIES) {
685 			/* Maybe the peer is detected as dead very soon...
686 			   retry at most once more in this case. */
687 			if (try < max_tries) {
688 				int timeo;
689 				try = max_tries - 1;
690 				rcu_read_lock();
691 				nc = rcu_dereference(connection->net_conf);
692 				timeo = nc ? (nc->ping_timeo + 1) * HZ / 10 : 1;
693 				rcu_read_unlock();
694 				schedule_timeout_interruptible(timeo);
695 			}
696 			continue;
697 		}
698 		if (rv < SS_SUCCESS) {
699 			rv = _drbd_request_state(device, mask, val,
700 						CS_VERBOSE + CS_WAIT_COMPLETE);
701 			if (rv < SS_SUCCESS)
702 				goto out;
703 		}
704 		break;
705 	}
706 
707 	if (rv < SS_SUCCESS)
708 		goto out;
709 
710 	if (forced)
711 		drbd_warn(device, "Forced to consider local data as UpToDate!\n");
712 
713 	/* Wait until nothing is on the fly :) */
714 	wait_event(device->misc_wait, atomic_read(&device->ap_pending_cnt) == 0);
715 
716 	/* FIXME also wait for all pending P_BARRIER_ACK? */
717 
718 	if (new_role == R_SECONDARY) {
719 		if (get_ldev(device)) {
720 			device->ldev->md.uuid[UI_CURRENT] &= ~(u64)1;
721 			put_ldev(device);
722 		}
723 	} else {
724 		mutex_lock(&device->resource->conf_update);
725 		nc = connection->net_conf;
726 		if (nc)
727 			nc->discard_my_data = 0; /* without copy; single bit op is atomic */
728 		mutex_unlock(&device->resource->conf_update);
729 
730 		if (get_ldev(device)) {
731 			if (((device->state.conn < C_CONNECTED ||
732 			       device->state.pdsk <= D_FAILED)
733 			      && device->ldev->md.uuid[UI_BITMAP] == 0) || forced)
734 				drbd_uuid_new_current(device);
735 
736 			device->ldev->md.uuid[UI_CURRENT] |=  (u64)1;
737 			put_ldev(device);
738 		}
739 	}
740 
741 	/* writeout of activity log covered areas of the bitmap
742 	 * to stable storage done in after state change already */
743 
744 	if (device->state.conn >= C_WF_REPORT_PARAMS) {
745 		/* if this was forced, we should consider sync */
746 		if (forced)
747 			drbd_send_uuids(peer_device);
748 		drbd_send_current_state(peer_device);
749 	}
750 
751 	drbd_md_sync(device);
752 	set_disk_ro(device->vdisk, new_role == R_SECONDARY);
753 	kobject_uevent(&disk_to_dev(device->vdisk)->kobj, KOBJ_CHANGE);
754 out:
755 	mutex_unlock(device->state_mutex);
756 	return rv;
757 }
758 
759 static const char *from_attrs_err_to_txt(int err)
760 {
761 	return	err == -ENOMSG ? "required attribute missing" :
762 		err == -EOPNOTSUPP ? "unknown mandatory attribute" :
763 		err == -EEXIST ? "can not change invariant setting" :
764 		"invalid attribute value";
765 }
766 
767 int drbd_adm_set_role(struct sk_buff *skb, struct genl_info *info)
768 {
769 	struct drbd_config_context adm_ctx;
770 	struct set_role_parms parms;
771 	int err;
772 	enum drbd_ret_code retcode;
773 	enum drbd_state_rv rv;
774 
775 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
776 	if (!adm_ctx.reply_skb)
777 		return retcode;
778 	if (retcode != NO_ERROR)
779 		goto out;
780 
781 	memset(&parms, 0, sizeof(parms));
782 	if (info->attrs[DRBD_NLA_SET_ROLE_PARMS]) {
783 		err = set_role_parms_from_attrs(&parms, info);
784 		if (err) {
785 			retcode = ERR_MANDATORY_TAG;
786 			drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
787 			goto out;
788 		}
789 	}
790 	genl_unlock();
791 	mutex_lock(&adm_ctx.resource->adm_mutex);
792 
793 	if (info->genlhdr->cmd == DRBD_ADM_PRIMARY)
794 		rv = drbd_set_role(adm_ctx.device, R_PRIMARY, parms.assume_uptodate);
795 	else
796 		rv = drbd_set_role(adm_ctx.device, R_SECONDARY, 0);
797 
798 	mutex_unlock(&adm_ctx.resource->adm_mutex);
799 	genl_lock();
800 	drbd_adm_finish(&adm_ctx, info, rv);
801 	return 0;
802 out:
803 	drbd_adm_finish(&adm_ctx, info, retcode);
804 	return 0;
805 }
806 
807 /* Initializes the md.*_offset members, so we are able to find
808  * the on disk meta data.
809  *
810  * We currently have two possible layouts:
811  * external:
812  *   |----------- md_size_sect ------------------|
813  *   [ 4k superblock ][ activity log ][  Bitmap  ]
814  *   | al_offset == 8 |
815  *   | bm_offset = al_offset + X      |
816  *  ==> bitmap sectors = md_size_sect - bm_offset
817  *
818  * internal:
819  *            |----------- md_size_sect ------------------|
820  * [data.....][  Bitmap  ][ activity log ][ 4k superblock ]
821  *                        | al_offset < 0 |
822  *            | bm_offset = al_offset - Y |
823  *  ==> bitmap sectors = Y = al_offset - bm_offset
824  *
825  *  Activity log size used to be fixed 32kB,
826  *  but is about to become configurable.
827  */
828 static void drbd_md_set_sector_offsets(struct drbd_device *device,
829 				       struct drbd_backing_dev *bdev)
830 {
831 	sector_t md_size_sect = 0;
832 	unsigned int al_size_sect = bdev->md.al_size_4k * 8;
833 
834 	bdev->md.md_offset = drbd_md_ss(bdev);
835 
836 	switch (bdev->md.meta_dev_idx) {
837 	default:
838 		/* v07 style fixed size indexed meta data */
839 		bdev->md.md_size_sect = MD_128MB_SECT;
840 		bdev->md.al_offset = MD_4kB_SECT;
841 		bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
842 		break;
843 	case DRBD_MD_INDEX_FLEX_EXT:
844 		/* just occupy the full device; unit: sectors */
845 		bdev->md.md_size_sect = drbd_get_capacity(bdev->md_bdev);
846 		bdev->md.al_offset = MD_4kB_SECT;
847 		bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
848 		break;
849 	case DRBD_MD_INDEX_INTERNAL:
850 	case DRBD_MD_INDEX_FLEX_INT:
851 		/* al size is still fixed */
852 		bdev->md.al_offset = -al_size_sect;
853 		/* we need (slightly less than) ~ this much bitmap sectors: */
854 		md_size_sect = drbd_get_capacity(bdev->backing_bdev);
855 		md_size_sect = ALIGN(md_size_sect, BM_SECT_PER_EXT);
856 		md_size_sect = BM_SECT_TO_EXT(md_size_sect);
857 		md_size_sect = ALIGN(md_size_sect, 8);
858 
859 		/* plus the "drbd meta data super block",
860 		 * and the activity log; */
861 		md_size_sect += MD_4kB_SECT + al_size_sect;
862 
863 		bdev->md.md_size_sect = md_size_sect;
864 		/* bitmap offset is adjusted by 'super' block size */
865 		bdev->md.bm_offset   = -md_size_sect + MD_4kB_SECT;
866 		break;
867 	}
868 }
869 
870 /* input size is expected to be in KB */
871 char *ppsize(char *buf, unsigned long long size)
872 {
873 	/* Needs 9 bytes at max including trailing NUL:
874 	 * -1ULL ==> "16384 EB" */
875 	static char units[] = { 'K', 'M', 'G', 'T', 'P', 'E' };
876 	int base = 0;
877 	while (size >= 10000 && base < sizeof(units)-1) {
878 		/* shift + round */
879 		size = (size >> 10) + !!(size & (1<<9));
880 		base++;
881 	}
882 	sprintf(buf, "%u %cB", (unsigned)size, units[base]);
883 
884 	return buf;
885 }
886 
887 /* there is still a theoretical deadlock when called from receiver
888  * on an D_INCONSISTENT R_PRIMARY:
889  *  remote READ does inc_ap_bio, receiver would need to receive answer
890  *  packet from remote to dec_ap_bio again.
891  *  receiver receive_sizes(), comes here,
892  *  waits for ap_bio_cnt == 0. -> deadlock.
893  * but this cannot happen, actually, because:
894  *  R_PRIMARY D_INCONSISTENT, and peer's disk is unreachable
895  *  (not connected, or bad/no disk on peer):
896  *  see drbd_fail_request_early, ap_bio_cnt is zero.
897  *  R_PRIMARY D_INCONSISTENT, and C_SYNC_TARGET:
898  *  peer may not initiate a resize.
899  */
900 /* Note these are not to be confused with
901  * drbd_adm_suspend_io/drbd_adm_resume_io,
902  * which are (sub) state changes triggered by admin (drbdsetup),
903  * and can be long lived.
904  * This changes an device->flag, is triggered by drbd internals,
905  * and should be short-lived. */
906 /* It needs to be a counter, since multiple threads might
907    independently suspend and resume IO. */
908 void drbd_suspend_io(struct drbd_device *device)
909 {
910 	atomic_inc(&device->suspend_cnt);
911 	if (drbd_suspended(device))
912 		return;
913 	wait_event(device->misc_wait, !atomic_read(&device->ap_bio_cnt));
914 }
915 
916 void drbd_resume_io(struct drbd_device *device)
917 {
918 	if (atomic_dec_and_test(&device->suspend_cnt))
919 		wake_up(&device->misc_wait);
920 }
921 
922 /*
923  * drbd_determine_dev_size() -  Sets the right device size obeying all constraints
924  * @device:	DRBD device.
925  *
926  * Returns 0 on success, negative return values indicate errors.
927  * You should call drbd_md_sync() after calling this function.
928  */
929 enum determine_dev_size
930 drbd_determine_dev_size(struct drbd_device *device, enum dds_flags flags, struct resize_parms *rs) __must_hold(local)
931 {
932 	struct md_offsets_and_sizes {
933 		u64 last_agreed_sect;
934 		u64 md_offset;
935 		s32 al_offset;
936 		s32 bm_offset;
937 		u32 md_size_sect;
938 
939 		u32 al_stripes;
940 		u32 al_stripe_size_4k;
941 	} prev;
942 	sector_t u_size, size;
943 	struct drbd_md *md = &device->ldev->md;
944 	void *buffer;
945 
946 	int md_moved, la_size_changed;
947 	enum determine_dev_size rv = DS_UNCHANGED;
948 
949 	/* We may change the on-disk offsets of our meta data below.  Lock out
950 	 * anything that may cause meta data IO, to avoid acting on incomplete
951 	 * layout changes or scribbling over meta data that is in the process
952 	 * of being moved.
953 	 *
954 	 * Move is not exactly correct, btw, currently we have all our meta
955 	 * data in core memory, to "move" it we just write it all out, there
956 	 * are no reads. */
957 	drbd_suspend_io(device);
958 	buffer = drbd_md_get_buffer(device, __func__); /* Lock meta-data IO */
959 	if (!buffer) {
960 		drbd_resume_io(device);
961 		return DS_ERROR;
962 	}
963 
964 	/* remember current offset and sizes */
965 	prev.last_agreed_sect = md->la_size_sect;
966 	prev.md_offset = md->md_offset;
967 	prev.al_offset = md->al_offset;
968 	prev.bm_offset = md->bm_offset;
969 	prev.md_size_sect = md->md_size_sect;
970 	prev.al_stripes = md->al_stripes;
971 	prev.al_stripe_size_4k = md->al_stripe_size_4k;
972 
973 	if (rs) {
974 		/* rs is non NULL if we should change the AL layout only */
975 		md->al_stripes = rs->al_stripes;
976 		md->al_stripe_size_4k = rs->al_stripe_size / 4;
977 		md->al_size_4k = (u64)rs->al_stripes * rs->al_stripe_size / 4;
978 	}
979 
980 	drbd_md_set_sector_offsets(device, device->ldev);
981 
982 	rcu_read_lock();
983 	u_size = rcu_dereference(device->ldev->disk_conf)->disk_size;
984 	rcu_read_unlock();
985 	size = drbd_new_dev_size(device, device->ldev, u_size, flags & DDSF_FORCED);
986 
987 	if (size < prev.last_agreed_sect) {
988 		if (rs && u_size == 0) {
989 			/* Remove "rs &&" later. This check should always be active, but
990 			   right now the receiver expects the permissive behavior */
991 			drbd_warn(device, "Implicit shrink not allowed. "
992 				 "Use --size=%llus for explicit shrink.\n",
993 				 (unsigned long long)size);
994 			rv = DS_ERROR_SHRINK;
995 		}
996 		if (u_size > size)
997 			rv = DS_ERROR_SPACE_MD;
998 		if (rv != DS_UNCHANGED)
999 			goto err_out;
1000 	}
1001 
1002 	if (get_capacity(device->vdisk) != size ||
1003 	    drbd_bm_capacity(device) != size) {
1004 		int err;
1005 		err = drbd_bm_resize(device, size, !(flags & DDSF_NO_RESYNC));
1006 		if (unlikely(err)) {
1007 			/* currently there is only one error: ENOMEM! */
1008 			size = drbd_bm_capacity(device);
1009 			if (size == 0) {
1010 				drbd_err(device, "OUT OF MEMORY! "
1011 				    "Could not allocate bitmap!\n");
1012 			} else {
1013 				drbd_err(device, "BM resizing failed. "
1014 				    "Leaving size unchanged\n");
1015 			}
1016 			rv = DS_ERROR;
1017 		}
1018 		/* racy, see comments above. */
1019 		drbd_set_my_capacity(device, size);
1020 		md->la_size_sect = size;
1021 	}
1022 	if (rv <= DS_ERROR)
1023 		goto err_out;
1024 
1025 	la_size_changed = (prev.last_agreed_sect != md->la_size_sect);
1026 
1027 	md_moved = prev.md_offset    != md->md_offset
1028 		|| prev.md_size_sect != md->md_size_sect;
1029 
1030 	if (la_size_changed || md_moved || rs) {
1031 		u32 prev_flags;
1032 
1033 		/* We do some synchronous IO below, which may take some time.
1034 		 * Clear the timer, to avoid scary "timer expired!" messages,
1035 		 * "Superblock" is written out at least twice below, anyways. */
1036 		del_timer(&device->md_sync_timer);
1037 
1038 		/* We won't change the "al-extents" setting, we just may need
1039 		 * to move the on-disk location of the activity log ringbuffer.
1040 		 * Lock for transaction is good enough, it may well be "dirty"
1041 		 * or even "starving". */
1042 		wait_event(device->al_wait, lc_try_lock_for_transaction(device->act_log));
1043 
1044 		/* mark current on-disk bitmap and activity log as unreliable */
1045 		prev_flags = md->flags;
1046 		md->flags |= MDF_FULL_SYNC | MDF_AL_DISABLED;
1047 		drbd_md_write(device, buffer);
1048 
1049 		drbd_al_initialize(device, buffer);
1050 
1051 		drbd_info(device, "Writing the whole bitmap, %s\n",
1052 			 la_size_changed && md_moved ? "size changed and md moved" :
1053 			 la_size_changed ? "size changed" : "md moved");
1054 		/* next line implicitly does drbd_suspend_io()+drbd_resume_io() */
1055 		drbd_bitmap_io(device, md_moved ? &drbd_bm_write_all : &drbd_bm_write,
1056 			       "size changed", BM_LOCKED_MASK, NULL);
1057 
1058 		/* on-disk bitmap and activity log is authoritative again
1059 		 * (unless there was an IO error meanwhile...) */
1060 		md->flags = prev_flags;
1061 		drbd_md_write(device, buffer);
1062 
1063 		if (rs)
1064 			drbd_info(device, "Changed AL layout to al-stripes = %d, al-stripe-size-kB = %d\n",
1065 				  md->al_stripes, md->al_stripe_size_4k * 4);
1066 	}
1067 
1068 	if (size > prev.last_agreed_sect)
1069 		rv = prev.last_agreed_sect ? DS_GREW : DS_GREW_FROM_ZERO;
1070 	if (size < prev.last_agreed_sect)
1071 		rv = DS_SHRUNK;
1072 
1073 	if (0) {
1074 	err_out:
1075 		/* restore previous offset and sizes */
1076 		md->la_size_sect = prev.last_agreed_sect;
1077 		md->md_offset = prev.md_offset;
1078 		md->al_offset = prev.al_offset;
1079 		md->bm_offset = prev.bm_offset;
1080 		md->md_size_sect = prev.md_size_sect;
1081 		md->al_stripes = prev.al_stripes;
1082 		md->al_stripe_size_4k = prev.al_stripe_size_4k;
1083 		md->al_size_4k = (u64)prev.al_stripes * prev.al_stripe_size_4k;
1084 	}
1085 	lc_unlock(device->act_log);
1086 	wake_up(&device->al_wait);
1087 	drbd_md_put_buffer(device);
1088 	drbd_resume_io(device);
1089 
1090 	return rv;
1091 }
1092 
1093 sector_t
1094 drbd_new_dev_size(struct drbd_device *device, struct drbd_backing_dev *bdev,
1095 		  sector_t u_size, int assume_peer_has_space)
1096 {
1097 	sector_t p_size = device->p_size;   /* partner's disk size. */
1098 	sector_t la_size_sect = bdev->md.la_size_sect; /* last agreed size. */
1099 	sector_t m_size; /* my size */
1100 	sector_t size = 0;
1101 
1102 	m_size = drbd_get_max_capacity(bdev);
1103 
1104 	if (device->state.conn < C_CONNECTED && assume_peer_has_space) {
1105 		drbd_warn(device, "Resize while not connected was forced by the user!\n");
1106 		p_size = m_size;
1107 	}
1108 
1109 	if (p_size && m_size) {
1110 		size = min_t(sector_t, p_size, m_size);
1111 	} else {
1112 		if (la_size_sect) {
1113 			size = la_size_sect;
1114 			if (m_size && m_size < size)
1115 				size = m_size;
1116 			if (p_size && p_size < size)
1117 				size = p_size;
1118 		} else {
1119 			if (m_size)
1120 				size = m_size;
1121 			if (p_size)
1122 				size = p_size;
1123 		}
1124 	}
1125 
1126 	if (size == 0)
1127 		drbd_err(device, "Both nodes diskless!\n");
1128 
1129 	if (u_size) {
1130 		if (u_size > size)
1131 			drbd_err(device, "Requested disk size is too big (%lu > %lu)\n",
1132 			    (unsigned long)u_size>>1, (unsigned long)size>>1);
1133 		else
1134 			size = u_size;
1135 	}
1136 
1137 	return size;
1138 }
1139 
1140 /*
1141  * drbd_check_al_size() - Ensures that the AL is of the right size
1142  * @device:	DRBD device.
1143  *
1144  * Returns -EBUSY if current al lru is still used, -ENOMEM when allocation
1145  * failed, and 0 on success. You should call drbd_md_sync() after you called
1146  * this function.
1147  */
1148 static int drbd_check_al_size(struct drbd_device *device, struct disk_conf *dc)
1149 {
1150 	struct lru_cache *n, *t;
1151 	struct lc_element *e;
1152 	unsigned int in_use;
1153 	int i;
1154 
1155 	if (device->act_log &&
1156 	    device->act_log->nr_elements == dc->al_extents)
1157 		return 0;
1158 
1159 	in_use = 0;
1160 	t = device->act_log;
1161 	n = lc_create("act_log", drbd_al_ext_cache, AL_UPDATES_PER_TRANSACTION,
1162 		dc->al_extents, sizeof(struct lc_element), 0);
1163 
1164 	if (n == NULL) {
1165 		drbd_err(device, "Cannot allocate act_log lru!\n");
1166 		return -ENOMEM;
1167 	}
1168 	spin_lock_irq(&device->al_lock);
1169 	if (t) {
1170 		for (i = 0; i < t->nr_elements; i++) {
1171 			e = lc_element_by_index(t, i);
1172 			if (e->refcnt)
1173 				drbd_err(device, "refcnt(%d)==%d\n",
1174 				    e->lc_number, e->refcnt);
1175 			in_use += e->refcnt;
1176 		}
1177 	}
1178 	if (!in_use)
1179 		device->act_log = n;
1180 	spin_unlock_irq(&device->al_lock);
1181 	if (in_use) {
1182 		drbd_err(device, "Activity log still in use!\n");
1183 		lc_destroy(n);
1184 		return -EBUSY;
1185 	} else {
1186 		lc_destroy(t);
1187 	}
1188 	drbd_md_mark_dirty(device); /* we changed device->act_log->nr_elemens */
1189 	return 0;
1190 }
1191 
1192 static void blk_queue_discard_granularity(struct request_queue *q, unsigned int granularity)
1193 {
1194 	q->limits.discard_granularity = granularity;
1195 }
1196 
1197 static unsigned int drbd_max_discard_sectors(struct drbd_connection *connection)
1198 {
1199 	/* when we introduced REQ_WRITE_SAME support, we also bumped
1200 	 * our maximum supported batch bio size used for discards. */
1201 	if (connection->agreed_features & DRBD_FF_WSAME)
1202 		return DRBD_MAX_BBIO_SECTORS;
1203 	/* before, with DRBD <= 8.4.6, we only allowed up to one AL_EXTENT_SIZE. */
1204 	return AL_EXTENT_SIZE >> 9;
1205 }
1206 
1207 static void decide_on_discard_support(struct drbd_device *device,
1208 		struct drbd_backing_dev *bdev)
1209 {
1210 	struct drbd_connection *connection =
1211 		first_peer_device(device)->connection;
1212 	struct request_queue *q = device->rq_queue;
1213 	unsigned int max_discard_sectors;
1214 
1215 	if (bdev && !bdev_max_discard_sectors(bdev->backing_bdev))
1216 		goto not_supported;
1217 
1218 	if (connection->cstate >= C_CONNECTED &&
1219 	    !(connection->agreed_features & DRBD_FF_TRIM)) {
1220 		drbd_info(connection,
1221 			"peer DRBD too old, does not support TRIM: disabling discards\n");
1222 		goto not_supported;
1223 	}
1224 
1225 	/*
1226 	 * We don't care for the granularity, really.
1227 	 *
1228 	 * Stacking limits below should fix it for the local device.  Whether or
1229 	 * not it is a suitable granularity on the remote device is not our
1230 	 * problem, really. If you care, you need to use devices with similar
1231 	 * topology on all peers.
1232 	 */
1233 	blk_queue_discard_granularity(q, 512);
1234 	max_discard_sectors = drbd_max_discard_sectors(connection);
1235 	blk_queue_max_discard_sectors(q, max_discard_sectors);
1236 	blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
1237 	return;
1238 
1239 not_supported:
1240 	blk_queue_discard_granularity(q, 0);
1241 	blk_queue_max_discard_sectors(q, 0);
1242 }
1243 
1244 static void fixup_write_zeroes(struct drbd_device *device, struct request_queue *q)
1245 {
1246 	/* Fixup max_write_zeroes_sectors after blk_stack_limits():
1247 	 * if we can handle "zeroes" efficiently on the protocol,
1248 	 * we want to do that, even if our backend does not announce
1249 	 * max_write_zeroes_sectors itself. */
1250 	struct drbd_connection *connection = first_peer_device(device)->connection;
1251 	/* If the peer announces WZEROES support, use it.  Otherwise, rather
1252 	 * send explicit zeroes than rely on some discard-zeroes-data magic. */
1253 	if (connection->agreed_features & DRBD_FF_WZEROES)
1254 		q->limits.max_write_zeroes_sectors = DRBD_MAX_BBIO_SECTORS;
1255 	else
1256 		q->limits.max_write_zeroes_sectors = 0;
1257 }
1258 
1259 static void fixup_discard_support(struct drbd_device *device, struct request_queue *q)
1260 {
1261 	unsigned int max_discard = device->rq_queue->limits.max_discard_sectors;
1262 	unsigned int discard_granularity =
1263 		device->rq_queue->limits.discard_granularity >> SECTOR_SHIFT;
1264 
1265 	if (discard_granularity > max_discard) {
1266 		blk_queue_discard_granularity(q, 0);
1267 		blk_queue_max_discard_sectors(q, 0);
1268 	}
1269 }
1270 
1271 static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backing_dev *bdev,
1272 				   unsigned int max_bio_size, struct o_qlim *o)
1273 {
1274 	struct request_queue * const q = device->rq_queue;
1275 	unsigned int max_hw_sectors = max_bio_size >> 9;
1276 	unsigned int max_segments = 0;
1277 	struct request_queue *b = NULL;
1278 	struct disk_conf *dc;
1279 
1280 	if (bdev) {
1281 		b = bdev->backing_bdev->bd_disk->queue;
1282 
1283 		max_hw_sectors = min(queue_max_hw_sectors(b), max_bio_size >> 9);
1284 		rcu_read_lock();
1285 		dc = rcu_dereference(device->ldev->disk_conf);
1286 		max_segments = dc->max_bio_bvecs;
1287 		rcu_read_unlock();
1288 
1289 		blk_set_stacking_limits(&q->limits);
1290 	}
1291 
1292 	blk_queue_max_hw_sectors(q, max_hw_sectors);
1293 	/* This is the workaround for "bio would need to, but cannot, be split" */
1294 	blk_queue_max_segments(q, max_segments ? max_segments : BLK_MAX_SEGMENTS);
1295 	blk_queue_segment_boundary(q, PAGE_SIZE-1);
1296 	decide_on_discard_support(device, bdev);
1297 
1298 	if (b) {
1299 		blk_stack_limits(&q->limits, &b->limits, 0);
1300 		disk_update_readahead(device->vdisk);
1301 	}
1302 	fixup_write_zeroes(device, q);
1303 	fixup_discard_support(device, q);
1304 }
1305 
1306 void drbd_reconsider_queue_parameters(struct drbd_device *device, struct drbd_backing_dev *bdev, struct o_qlim *o)
1307 {
1308 	unsigned int now, new, local, peer;
1309 
1310 	now = queue_max_hw_sectors(device->rq_queue) << 9;
1311 	local = device->local_max_bio_size; /* Eventually last known value, from volatile memory */
1312 	peer = device->peer_max_bio_size; /* Eventually last known value, from meta data */
1313 
1314 	if (bdev) {
1315 		local = queue_max_hw_sectors(bdev->backing_bdev->bd_disk->queue) << 9;
1316 		device->local_max_bio_size = local;
1317 	}
1318 	local = min(local, DRBD_MAX_BIO_SIZE);
1319 
1320 	/* We may ignore peer limits if the peer is modern enough.
1321 	   Because new from 8.3.8 onwards the peer can use multiple
1322 	   BIOs for a single peer_request */
1323 	if (device->state.conn >= C_WF_REPORT_PARAMS) {
1324 		if (first_peer_device(device)->connection->agreed_pro_version < 94)
1325 			peer = min(device->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
1326 			/* Correct old drbd (up to 8.3.7) if it believes it can do more than 32KiB */
1327 		else if (first_peer_device(device)->connection->agreed_pro_version == 94)
1328 			peer = DRBD_MAX_SIZE_H80_PACKET;
1329 		else if (first_peer_device(device)->connection->agreed_pro_version < 100)
1330 			peer = DRBD_MAX_BIO_SIZE_P95;  /* drbd 8.3.8 onwards, before 8.4.0 */
1331 		else
1332 			peer = DRBD_MAX_BIO_SIZE;
1333 
1334 		/* We may later detach and re-attach on a disconnected Primary.
1335 		 * Avoid this setting to jump back in that case.
1336 		 * We want to store what we know the peer DRBD can handle,
1337 		 * not what the peer IO backend can handle. */
1338 		if (peer > device->peer_max_bio_size)
1339 			device->peer_max_bio_size = peer;
1340 	}
1341 	new = min(local, peer);
1342 
1343 	if (device->state.role == R_PRIMARY && new < now)
1344 		drbd_err(device, "ASSERT FAILED new < now; (%u < %u)\n", new, now);
1345 
1346 	if (new != now)
1347 		drbd_info(device, "max BIO size = %u\n", new);
1348 
1349 	drbd_setup_queue_param(device, bdev, new, o);
1350 }
1351 
1352 /* Starts the worker thread */
1353 static void conn_reconfig_start(struct drbd_connection *connection)
1354 {
1355 	drbd_thread_start(&connection->worker);
1356 	drbd_flush_workqueue(&connection->sender_work);
1357 }
1358 
1359 /* if still unconfigured, stops worker again. */
1360 static void conn_reconfig_done(struct drbd_connection *connection)
1361 {
1362 	bool stop_threads;
1363 	spin_lock_irq(&connection->resource->req_lock);
1364 	stop_threads = conn_all_vols_unconf(connection) &&
1365 		connection->cstate == C_STANDALONE;
1366 	spin_unlock_irq(&connection->resource->req_lock);
1367 	if (stop_threads) {
1368 		/* ack_receiver thread and ack_sender workqueue are implicitly
1369 		 * stopped by receiver in conn_disconnect() */
1370 		drbd_thread_stop(&connection->receiver);
1371 		drbd_thread_stop(&connection->worker);
1372 	}
1373 }
1374 
1375 /* Make sure IO is suspended before calling this function(). */
1376 static void drbd_suspend_al(struct drbd_device *device)
1377 {
1378 	int s = 0;
1379 
1380 	if (!lc_try_lock(device->act_log)) {
1381 		drbd_warn(device, "Failed to lock al in drbd_suspend_al()\n");
1382 		return;
1383 	}
1384 
1385 	drbd_al_shrink(device);
1386 	spin_lock_irq(&device->resource->req_lock);
1387 	if (device->state.conn < C_CONNECTED)
1388 		s = !test_and_set_bit(AL_SUSPENDED, &device->flags);
1389 	spin_unlock_irq(&device->resource->req_lock);
1390 	lc_unlock(device->act_log);
1391 
1392 	if (s)
1393 		drbd_info(device, "Suspended AL updates\n");
1394 }
1395 
1396 
1397 static bool should_set_defaults(struct genl_info *info)
1398 {
1399 	struct drbd_genlmsghdr *dh = genl_info_userhdr(info);
1400 
1401 	return 0 != (dh->flags & DRBD_GENL_F_SET_DEFAULTS);
1402 }
1403 
1404 static unsigned int drbd_al_extents_max(struct drbd_backing_dev *bdev)
1405 {
1406 	/* This is limited by 16 bit "slot" numbers,
1407 	 * and by available on-disk context storage.
1408 	 *
1409 	 * Also (u16)~0 is special (denotes a "free" extent).
1410 	 *
1411 	 * One transaction occupies one 4kB on-disk block,
1412 	 * we have n such blocks in the on disk ring buffer,
1413 	 * the "current" transaction may fail (n-1),
1414 	 * and there is 919 slot numbers context information per transaction.
1415 	 *
1416 	 * 72 transaction blocks amounts to more than 2**16 context slots,
1417 	 * so cap there first.
1418 	 */
1419 	const unsigned int max_al_nr = DRBD_AL_EXTENTS_MAX;
1420 	const unsigned int sufficient_on_disk =
1421 		(max_al_nr + AL_CONTEXT_PER_TRANSACTION -1)
1422 		/AL_CONTEXT_PER_TRANSACTION;
1423 
1424 	unsigned int al_size_4k = bdev->md.al_size_4k;
1425 
1426 	if (al_size_4k > sufficient_on_disk)
1427 		return max_al_nr;
1428 
1429 	return (al_size_4k - 1) * AL_CONTEXT_PER_TRANSACTION;
1430 }
1431 
1432 static bool write_ordering_changed(struct disk_conf *a, struct disk_conf *b)
1433 {
1434 	return	a->disk_barrier != b->disk_barrier ||
1435 		a->disk_flushes != b->disk_flushes ||
1436 		a->disk_drain != b->disk_drain;
1437 }
1438 
1439 static void sanitize_disk_conf(struct drbd_device *device, struct disk_conf *disk_conf,
1440 			       struct drbd_backing_dev *nbc)
1441 {
1442 	struct block_device *bdev = nbc->backing_bdev;
1443 
1444 	if (disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
1445 		disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
1446 	if (disk_conf->al_extents > drbd_al_extents_max(nbc))
1447 		disk_conf->al_extents = drbd_al_extents_max(nbc);
1448 
1449 	if (!bdev_max_discard_sectors(bdev)) {
1450 		if (disk_conf->rs_discard_granularity) {
1451 			disk_conf->rs_discard_granularity = 0; /* disable feature */
1452 			drbd_info(device, "rs_discard_granularity feature disabled\n");
1453 		}
1454 	}
1455 
1456 	if (disk_conf->rs_discard_granularity) {
1457 		int orig_value = disk_conf->rs_discard_granularity;
1458 		sector_t discard_size = bdev_max_discard_sectors(bdev) << 9;
1459 		unsigned int discard_granularity = bdev_discard_granularity(bdev);
1460 		int remainder;
1461 
1462 		if (discard_granularity > disk_conf->rs_discard_granularity)
1463 			disk_conf->rs_discard_granularity = discard_granularity;
1464 
1465 		remainder = disk_conf->rs_discard_granularity %
1466 				discard_granularity;
1467 		disk_conf->rs_discard_granularity += remainder;
1468 
1469 		if (disk_conf->rs_discard_granularity > discard_size)
1470 			disk_conf->rs_discard_granularity = discard_size;
1471 
1472 		if (disk_conf->rs_discard_granularity != orig_value)
1473 			drbd_info(device, "rs_discard_granularity changed to %d\n",
1474 				  disk_conf->rs_discard_granularity);
1475 	}
1476 }
1477 
1478 static int disk_opts_check_al_size(struct drbd_device *device, struct disk_conf *dc)
1479 {
1480 	int err = -EBUSY;
1481 
1482 	if (device->act_log &&
1483 	    device->act_log->nr_elements == dc->al_extents)
1484 		return 0;
1485 
1486 	drbd_suspend_io(device);
1487 	/* If IO completion is currently blocked, we would likely wait
1488 	 * "forever" for the activity log to become unused. So we don't. */
1489 	if (atomic_read(&device->ap_bio_cnt))
1490 		goto out;
1491 
1492 	wait_event(device->al_wait, lc_try_lock(device->act_log));
1493 	drbd_al_shrink(device);
1494 	err = drbd_check_al_size(device, dc);
1495 	lc_unlock(device->act_log);
1496 	wake_up(&device->al_wait);
1497 out:
1498 	drbd_resume_io(device);
1499 	return err;
1500 }
1501 
1502 int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
1503 {
1504 	struct drbd_config_context adm_ctx;
1505 	enum drbd_ret_code retcode;
1506 	struct drbd_device *device;
1507 	struct disk_conf *new_disk_conf, *old_disk_conf;
1508 	struct fifo_buffer *old_plan = NULL, *new_plan = NULL;
1509 	int err;
1510 	unsigned int fifo_size;
1511 
1512 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
1513 	if (!adm_ctx.reply_skb)
1514 		return retcode;
1515 	if (retcode != NO_ERROR)
1516 		goto finish;
1517 
1518 	device = adm_ctx.device;
1519 	mutex_lock(&adm_ctx.resource->adm_mutex);
1520 
1521 	/* we also need a disk
1522 	 * to change the options on */
1523 	if (!get_ldev(device)) {
1524 		retcode = ERR_NO_DISK;
1525 		goto out;
1526 	}
1527 
1528 	new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
1529 	if (!new_disk_conf) {
1530 		retcode = ERR_NOMEM;
1531 		goto fail;
1532 	}
1533 
1534 	mutex_lock(&device->resource->conf_update);
1535 	old_disk_conf = device->ldev->disk_conf;
1536 	*new_disk_conf = *old_disk_conf;
1537 	if (should_set_defaults(info))
1538 		set_disk_conf_defaults(new_disk_conf);
1539 
1540 	err = disk_conf_from_attrs_for_change(new_disk_conf, info);
1541 	if (err && err != -ENOMSG) {
1542 		retcode = ERR_MANDATORY_TAG;
1543 		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
1544 		goto fail_unlock;
1545 	}
1546 
1547 	if (!expect(device, new_disk_conf->resync_rate >= 1))
1548 		new_disk_conf->resync_rate = 1;
1549 
1550 	sanitize_disk_conf(device, new_disk_conf, device->ldev);
1551 
1552 	if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
1553 		new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
1554 
1555 	fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ;
1556 	if (fifo_size != device->rs_plan_s->size) {
1557 		new_plan = fifo_alloc(fifo_size);
1558 		if (!new_plan) {
1559 			drbd_err(device, "kmalloc of fifo_buffer failed");
1560 			retcode = ERR_NOMEM;
1561 			goto fail_unlock;
1562 		}
1563 	}
1564 
1565 	err = disk_opts_check_al_size(device, new_disk_conf);
1566 	if (err) {
1567 		/* Could be just "busy". Ignore?
1568 		 * Introduce dedicated error code? */
1569 		drbd_msg_put_info(adm_ctx.reply_skb,
1570 			"Try again without changing current al-extents setting");
1571 		retcode = ERR_NOMEM;
1572 		goto fail_unlock;
1573 	}
1574 
1575 	lock_all_resources();
1576 	retcode = drbd_resync_after_valid(device, new_disk_conf->resync_after);
1577 	if (retcode == NO_ERROR) {
1578 		rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
1579 		drbd_resync_after_changed(device);
1580 	}
1581 	unlock_all_resources();
1582 
1583 	if (retcode != NO_ERROR)
1584 		goto fail_unlock;
1585 
1586 	if (new_plan) {
1587 		old_plan = device->rs_plan_s;
1588 		rcu_assign_pointer(device->rs_plan_s, new_plan);
1589 	}
1590 
1591 	mutex_unlock(&device->resource->conf_update);
1592 
1593 	if (new_disk_conf->al_updates)
1594 		device->ldev->md.flags &= ~MDF_AL_DISABLED;
1595 	else
1596 		device->ldev->md.flags |= MDF_AL_DISABLED;
1597 
1598 	if (new_disk_conf->md_flushes)
1599 		clear_bit(MD_NO_FUA, &device->flags);
1600 	else
1601 		set_bit(MD_NO_FUA, &device->flags);
1602 
1603 	if (write_ordering_changed(old_disk_conf, new_disk_conf))
1604 		drbd_bump_write_ordering(device->resource, NULL, WO_BDEV_FLUSH);
1605 
1606 	if (old_disk_conf->discard_zeroes_if_aligned !=
1607 	    new_disk_conf->discard_zeroes_if_aligned)
1608 		drbd_reconsider_queue_parameters(device, device->ldev, NULL);
1609 
1610 	drbd_md_sync(device);
1611 
1612 	if (device->state.conn >= C_CONNECTED) {
1613 		struct drbd_peer_device *peer_device;
1614 
1615 		for_each_peer_device(peer_device, device)
1616 			drbd_send_sync_param(peer_device);
1617 	}
1618 
1619 	kvfree_rcu_mightsleep(old_disk_conf);
1620 	kfree(old_plan);
1621 	mod_timer(&device->request_timer, jiffies + HZ);
1622 	goto success;
1623 
1624 fail_unlock:
1625 	mutex_unlock(&device->resource->conf_update);
1626  fail:
1627 	kfree(new_disk_conf);
1628 	kfree(new_plan);
1629 success:
1630 	put_ldev(device);
1631  out:
1632 	mutex_unlock(&adm_ctx.resource->adm_mutex);
1633  finish:
1634 	drbd_adm_finish(&adm_ctx, info, retcode);
1635 	return 0;
1636 }
1637 
1638 static struct block_device *open_backing_dev(struct drbd_device *device,
1639 		const char *bdev_path, void *claim_ptr, bool do_bd_link)
1640 {
1641 	struct block_device *bdev;
1642 	int err = 0;
1643 
1644 	bdev = blkdev_get_by_path(bdev_path, BLK_OPEN_READ | BLK_OPEN_WRITE,
1645 				  claim_ptr, NULL);
1646 	if (IS_ERR(bdev)) {
1647 		drbd_err(device, "open(\"%s\") failed with %ld\n",
1648 				bdev_path, PTR_ERR(bdev));
1649 		return bdev;
1650 	}
1651 
1652 	if (!do_bd_link)
1653 		return bdev;
1654 
1655 	err = bd_link_disk_holder(bdev, device->vdisk);
1656 	if (err) {
1657 		blkdev_put(bdev, claim_ptr);
1658 		drbd_err(device, "bd_link_disk_holder(\"%s\", ...) failed with %d\n",
1659 				bdev_path, err);
1660 		bdev = ERR_PTR(err);
1661 	}
1662 	return bdev;
1663 }
1664 
1665 static int open_backing_devices(struct drbd_device *device,
1666 		struct disk_conf *new_disk_conf,
1667 		struct drbd_backing_dev *nbc)
1668 {
1669 	struct block_device *bdev;
1670 
1671 	bdev = open_backing_dev(device, new_disk_conf->backing_dev, device, true);
1672 	if (IS_ERR(bdev))
1673 		return ERR_OPEN_DISK;
1674 	nbc->backing_bdev = bdev;
1675 
1676 	/*
1677 	 * meta_dev_idx >= 0: external fixed size, possibly multiple
1678 	 * drbd sharing one meta device.  TODO in that case, paranoia
1679 	 * check that [md_bdev, meta_dev_idx] is not yet used by some
1680 	 * other drbd minor!  (if you use drbd.conf + drbdadm, that
1681 	 * should check it for you already; but if you don't, or
1682 	 * someone fooled it, we need to double check here)
1683 	 */
1684 	bdev = open_backing_dev(device, new_disk_conf->meta_dev,
1685 		/* claim ptr: device, if claimed exclusively; shared drbd_m_holder,
1686 		 * if potentially shared with other drbd minors */
1687 			(new_disk_conf->meta_dev_idx < 0) ? (void*)device : (void*)drbd_m_holder,
1688 		/* avoid double bd_claim_by_disk() for the same (source,target) tuple,
1689 		 * as would happen with internal metadata. */
1690 			(new_disk_conf->meta_dev_idx != DRBD_MD_INDEX_FLEX_INT &&
1691 			 new_disk_conf->meta_dev_idx != DRBD_MD_INDEX_INTERNAL));
1692 	if (IS_ERR(bdev))
1693 		return ERR_OPEN_MD_DISK;
1694 	nbc->md_bdev = bdev;
1695 	return NO_ERROR;
1696 }
1697 
1698 static void close_backing_dev(struct drbd_device *device, struct block_device *bdev,
1699 		void *claim_ptr, bool do_bd_unlink)
1700 {
1701 	if (!bdev)
1702 		return;
1703 	if (do_bd_unlink)
1704 		bd_unlink_disk_holder(bdev, device->vdisk);
1705 	blkdev_put(bdev, claim_ptr);
1706 }
1707 
1708 void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev)
1709 {
1710 	if (ldev == NULL)
1711 		return;
1712 
1713 	close_backing_dev(device, ldev->md_bdev,
1714 			  ldev->md.meta_dev_idx < 0 ?
1715 				(void *)device : (void *)drbd_m_holder,
1716 			  ldev->md_bdev != ldev->backing_bdev);
1717 	close_backing_dev(device, ldev->backing_bdev, device, true);
1718 
1719 	kfree(ldev->disk_conf);
1720 	kfree(ldev);
1721 }
1722 
1723 int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info)
1724 {
1725 	struct drbd_config_context adm_ctx;
1726 	struct drbd_device *device;
1727 	struct drbd_peer_device *peer_device;
1728 	struct drbd_connection *connection;
1729 	int err;
1730 	enum drbd_ret_code retcode;
1731 	enum determine_dev_size dd;
1732 	sector_t max_possible_sectors;
1733 	sector_t min_md_device_sectors;
1734 	struct drbd_backing_dev *nbc = NULL; /* new_backing_conf */
1735 	struct disk_conf *new_disk_conf = NULL;
1736 	struct lru_cache *resync_lru = NULL;
1737 	struct fifo_buffer *new_plan = NULL;
1738 	union drbd_state ns, os;
1739 	enum drbd_state_rv rv;
1740 	struct net_conf *nc;
1741 
1742 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
1743 	if (!adm_ctx.reply_skb)
1744 		return retcode;
1745 	if (retcode != NO_ERROR)
1746 		goto finish;
1747 
1748 	device = adm_ctx.device;
1749 	mutex_lock(&adm_ctx.resource->adm_mutex);
1750 	peer_device = first_peer_device(device);
1751 	connection = peer_device->connection;
1752 	conn_reconfig_start(connection);
1753 
1754 	/* if you want to reconfigure, please tear down first */
1755 	if (device->state.disk > D_DISKLESS) {
1756 		retcode = ERR_DISK_CONFIGURED;
1757 		goto fail;
1758 	}
1759 	/* It may just now have detached because of IO error.  Make sure
1760 	 * drbd_ldev_destroy is done already, we may end up here very fast,
1761 	 * e.g. if someone calls attach from the on-io-error handler,
1762 	 * to realize a "hot spare" feature (not that I'd recommend that) */
1763 	wait_event(device->misc_wait, !test_bit(GOING_DISKLESS, &device->flags));
1764 
1765 	/* make sure there is no leftover from previous force-detach attempts */
1766 	clear_bit(FORCE_DETACH, &device->flags);
1767 	clear_bit(WAS_IO_ERROR, &device->flags);
1768 	clear_bit(WAS_READ_ERROR, &device->flags);
1769 
1770 	/* and no leftover from previously aborted resync or verify, either */
1771 	device->rs_total = 0;
1772 	device->rs_failed = 0;
1773 	atomic_set(&device->rs_pending_cnt, 0);
1774 
1775 	/* allocation not in the IO path, drbdsetup context */
1776 	nbc = kzalloc(sizeof(struct drbd_backing_dev), GFP_KERNEL);
1777 	if (!nbc) {
1778 		retcode = ERR_NOMEM;
1779 		goto fail;
1780 	}
1781 	spin_lock_init(&nbc->md.uuid_lock);
1782 
1783 	new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
1784 	if (!new_disk_conf) {
1785 		retcode = ERR_NOMEM;
1786 		goto fail;
1787 	}
1788 	nbc->disk_conf = new_disk_conf;
1789 
1790 	set_disk_conf_defaults(new_disk_conf);
1791 	err = disk_conf_from_attrs(new_disk_conf, info);
1792 	if (err) {
1793 		retcode = ERR_MANDATORY_TAG;
1794 		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
1795 		goto fail;
1796 	}
1797 
1798 	if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
1799 		new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
1800 
1801 	new_plan = fifo_alloc((new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ);
1802 	if (!new_plan) {
1803 		retcode = ERR_NOMEM;
1804 		goto fail;
1805 	}
1806 
1807 	if (new_disk_conf->meta_dev_idx < DRBD_MD_INDEX_FLEX_INT) {
1808 		retcode = ERR_MD_IDX_INVALID;
1809 		goto fail;
1810 	}
1811 
1812 	rcu_read_lock();
1813 	nc = rcu_dereference(connection->net_conf);
1814 	if (nc) {
1815 		if (new_disk_conf->fencing == FP_STONITH && nc->wire_protocol == DRBD_PROT_A) {
1816 			rcu_read_unlock();
1817 			retcode = ERR_STONITH_AND_PROT_A;
1818 			goto fail;
1819 		}
1820 	}
1821 	rcu_read_unlock();
1822 
1823 	retcode = open_backing_devices(device, new_disk_conf, nbc);
1824 	if (retcode != NO_ERROR)
1825 		goto fail;
1826 
1827 	if ((nbc->backing_bdev == nbc->md_bdev) !=
1828 	    (new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
1829 	     new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)) {
1830 		retcode = ERR_MD_IDX_INVALID;
1831 		goto fail;
1832 	}
1833 
1834 	resync_lru = lc_create("resync", drbd_bm_ext_cache,
1835 			1, 61, sizeof(struct bm_extent),
1836 			offsetof(struct bm_extent, lce));
1837 	if (!resync_lru) {
1838 		retcode = ERR_NOMEM;
1839 		goto fail;
1840 	}
1841 
1842 	/* Read our meta data super block early.
1843 	 * This also sets other on-disk offsets. */
1844 	retcode = drbd_md_read(device, nbc);
1845 	if (retcode != NO_ERROR)
1846 		goto fail;
1847 
1848 	sanitize_disk_conf(device, new_disk_conf, nbc);
1849 
1850 	if (drbd_get_max_capacity(nbc) < new_disk_conf->disk_size) {
1851 		drbd_err(device, "max capacity %llu smaller than disk size %llu\n",
1852 			(unsigned long long) drbd_get_max_capacity(nbc),
1853 			(unsigned long long) new_disk_conf->disk_size);
1854 		retcode = ERR_DISK_TOO_SMALL;
1855 		goto fail;
1856 	}
1857 
1858 	if (new_disk_conf->meta_dev_idx < 0) {
1859 		max_possible_sectors = DRBD_MAX_SECTORS_FLEX;
1860 		/* at least one MB, otherwise it does not make sense */
1861 		min_md_device_sectors = (2<<10);
1862 	} else {
1863 		max_possible_sectors = DRBD_MAX_SECTORS;
1864 		min_md_device_sectors = MD_128MB_SECT * (new_disk_conf->meta_dev_idx + 1);
1865 	}
1866 
1867 	if (drbd_get_capacity(nbc->md_bdev) < min_md_device_sectors) {
1868 		retcode = ERR_MD_DISK_TOO_SMALL;
1869 		drbd_warn(device, "refusing attach: md-device too small, "
1870 		     "at least %llu sectors needed for this meta-disk type\n",
1871 		     (unsigned long long) min_md_device_sectors);
1872 		goto fail;
1873 	}
1874 
1875 	/* Make sure the new disk is big enough
1876 	 * (we may currently be R_PRIMARY with no local disk...) */
1877 	if (drbd_get_max_capacity(nbc) < get_capacity(device->vdisk)) {
1878 		retcode = ERR_DISK_TOO_SMALL;
1879 		goto fail;
1880 	}
1881 
1882 	nbc->known_size = drbd_get_capacity(nbc->backing_bdev);
1883 
1884 	if (nbc->known_size > max_possible_sectors) {
1885 		drbd_warn(device, "==> truncating very big lower level device "
1886 			"to currently maximum possible %llu sectors <==\n",
1887 			(unsigned long long) max_possible_sectors);
1888 		if (new_disk_conf->meta_dev_idx >= 0)
1889 			drbd_warn(device, "==>> using internal or flexible "
1890 				      "meta data may help <<==\n");
1891 	}
1892 
1893 	drbd_suspend_io(device);
1894 	/* also wait for the last barrier ack. */
1895 	/* FIXME see also https://daiquiri.linbit/cgi-bin/bugzilla/show_bug.cgi?id=171
1896 	 * We need a way to either ignore barrier acks for barriers sent before a device
1897 	 * was attached, or a way to wait for all pending barrier acks to come in.
1898 	 * As barriers are counted per resource,
1899 	 * we'd need to suspend io on all devices of a resource.
1900 	 */
1901 	wait_event(device->misc_wait, !atomic_read(&device->ap_pending_cnt) || drbd_suspended(device));
1902 	/* and for any other previously queued work */
1903 	drbd_flush_workqueue(&connection->sender_work);
1904 
1905 	rv = _drbd_request_state(device, NS(disk, D_ATTACHING), CS_VERBOSE);
1906 	retcode = (enum drbd_ret_code)rv;
1907 	drbd_resume_io(device);
1908 	if (rv < SS_SUCCESS)
1909 		goto fail;
1910 
1911 	if (!get_ldev_if_state(device, D_ATTACHING))
1912 		goto force_diskless;
1913 
1914 	if (!device->bitmap) {
1915 		if (drbd_bm_init(device)) {
1916 			retcode = ERR_NOMEM;
1917 			goto force_diskless_dec;
1918 		}
1919 	}
1920 
1921 	if (device->state.pdsk != D_UP_TO_DATE && device->ed_uuid &&
1922 	    (device->state.role == R_PRIMARY || device->state.peer == R_PRIMARY) &&
1923             (device->ed_uuid & ~((u64)1)) != (nbc->md.uuid[UI_CURRENT] & ~((u64)1))) {
1924 		drbd_err(device, "Can only attach to data with current UUID=%016llX\n",
1925 		    (unsigned long long)device->ed_uuid);
1926 		retcode = ERR_DATA_NOT_CURRENT;
1927 		goto force_diskless_dec;
1928 	}
1929 
1930 	/* Since we are diskless, fix the activity log first... */
1931 	if (drbd_check_al_size(device, new_disk_conf)) {
1932 		retcode = ERR_NOMEM;
1933 		goto force_diskless_dec;
1934 	}
1935 
1936 	/* Prevent shrinking of consistent devices ! */
1937 	{
1938 	unsigned long long nsz = drbd_new_dev_size(device, nbc, nbc->disk_conf->disk_size, 0);
1939 	unsigned long long eff = nbc->md.la_size_sect;
1940 	if (drbd_md_test_flag(nbc, MDF_CONSISTENT) && nsz < eff) {
1941 		if (nsz == nbc->disk_conf->disk_size) {
1942 			drbd_warn(device, "truncating a consistent device during attach (%llu < %llu)\n", nsz, eff);
1943 		} else {
1944 			drbd_warn(device, "refusing to truncate a consistent device (%llu < %llu)\n", nsz, eff);
1945 			drbd_msg_sprintf_info(adm_ctx.reply_skb,
1946 				"To-be-attached device has last effective > current size, and is consistent\n"
1947 				"(%llu > %llu sectors). Refusing to attach.", eff, nsz);
1948 			retcode = ERR_IMPLICIT_SHRINK;
1949 			goto force_diskless_dec;
1950 		}
1951 	}
1952 	}
1953 
1954 	lock_all_resources();
1955 	retcode = drbd_resync_after_valid(device, new_disk_conf->resync_after);
1956 	if (retcode != NO_ERROR) {
1957 		unlock_all_resources();
1958 		goto force_diskless_dec;
1959 	}
1960 
1961 	/* Reset the "barriers don't work" bits here, then force meta data to
1962 	 * be written, to ensure we determine if barriers are supported. */
1963 	if (new_disk_conf->md_flushes)
1964 		clear_bit(MD_NO_FUA, &device->flags);
1965 	else
1966 		set_bit(MD_NO_FUA, &device->flags);
1967 
1968 	/* Point of no return reached.
1969 	 * Devices and memory are no longer released by error cleanup below.
1970 	 * now device takes over responsibility, and the state engine should
1971 	 * clean it up somewhere.  */
1972 	D_ASSERT(device, device->ldev == NULL);
1973 	device->ldev = nbc;
1974 	device->resync = resync_lru;
1975 	device->rs_plan_s = new_plan;
1976 	nbc = NULL;
1977 	resync_lru = NULL;
1978 	new_disk_conf = NULL;
1979 	new_plan = NULL;
1980 
1981 	drbd_resync_after_changed(device);
1982 	drbd_bump_write_ordering(device->resource, device->ldev, WO_BDEV_FLUSH);
1983 	unlock_all_resources();
1984 
1985 	if (drbd_md_test_flag(device->ldev, MDF_CRASHED_PRIMARY))
1986 		set_bit(CRASHED_PRIMARY, &device->flags);
1987 	else
1988 		clear_bit(CRASHED_PRIMARY, &device->flags);
1989 
1990 	if (drbd_md_test_flag(device->ldev, MDF_PRIMARY_IND) &&
1991 	    !(device->state.role == R_PRIMARY && device->resource->susp_nod))
1992 		set_bit(CRASHED_PRIMARY, &device->flags);
1993 
1994 	device->send_cnt = 0;
1995 	device->recv_cnt = 0;
1996 	device->read_cnt = 0;
1997 	device->writ_cnt = 0;
1998 
1999 	drbd_reconsider_queue_parameters(device, device->ldev, NULL);
2000 
2001 	/* If I am currently not R_PRIMARY,
2002 	 * but meta data primary indicator is set,
2003 	 * I just now recover from a hard crash,
2004 	 * and have been R_PRIMARY before that crash.
2005 	 *
2006 	 * Now, if I had no connection before that crash
2007 	 * (have been degraded R_PRIMARY), chances are that
2008 	 * I won't find my peer now either.
2009 	 *
2010 	 * In that case, and _only_ in that case,
2011 	 * we use the degr-wfc-timeout instead of the default,
2012 	 * so we can automatically recover from a crash of a
2013 	 * degraded but active "cluster" after a certain timeout.
2014 	 */
2015 	clear_bit(USE_DEGR_WFC_T, &device->flags);
2016 	if (device->state.role != R_PRIMARY &&
2017 	     drbd_md_test_flag(device->ldev, MDF_PRIMARY_IND) &&
2018 	    !drbd_md_test_flag(device->ldev, MDF_CONNECTED_IND))
2019 		set_bit(USE_DEGR_WFC_T, &device->flags);
2020 
2021 	dd = drbd_determine_dev_size(device, 0, NULL);
2022 	if (dd <= DS_ERROR) {
2023 		retcode = ERR_NOMEM_BITMAP;
2024 		goto force_diskless_dec;
2025 	} else if (dd == DS_GREW)
2026 		set_bit(RESYNC_AFTER_NEG, &device->flags);
2027 
2028 	if (drbd_md_test_flag(device->ldev, MDF_FULL_SYNC) ||
2029 	    (test_bit(CRASHED_PRIMARY, &device->flags) &&
2030 	     drbd_md_test_flag(device->ldev, MDF_AL_DISABLED))) {
2031 		drbd_info(device, "Assuming that all blocks are out of sync "
2032 		     "(aka FullSync)\n");
2033 		if (drbd_bitmap_io(device, &drbd_bmio_set_n_write,
2034 			"set_n_write from attaching", BM_LOCKED_MASK,
2035 			NULL)) {
2036 			retcode = ERR_IO_MD_DISK;
2037 			goto force_diskless_dec;
2038 		}
2039 	} else {
2040 		if (drbd_bitmap_io(device, &drbd_bm_read,
2041 			"read from attaching", BM_LOCKED_MASK,
2042 			NULL)) {
2043 			retcode = ERR_IO_MD_DISK;
2044 			goto force_diskless_dec;
2045 		}
2046 	}
2047 
2048 	if (_drbd_bm_total_weight(device) == drbd_bm_bits(device))
2049 		drbd_suspend_al(device); /* IO is still suspended here... */
2050 
2051 	spin_lock_irq(&device->resource->req_lock);
2052 	os = drbd_read_state(device);
2053 	ns = os;
2054 	/* If MDF_CONSISTENT is not set go into inconsistent state,
2055 	   otherwise investigate MDF_WasUpToDate...
2056 	   If MDF_WAS_UP_TO_DATE is not set go into D_OUTDATED disk state,
2057 	   otherwise into D_CONSISTENT state.
2058 	*/
2059 	if (drbd_md_test_flag(device->ldev, MDF_CONSISTENT)) {
2060 		if (drbd_md_test_flag(device->ldev, MDF_WAS_UP_TO_DATE))
2061 			ns.disk = D_CONSISTENT;
2062 		else
2063 			ns.disk = D_OUTDATED;
2064 	} else {
2065 		ns.disk = D_INCONSISTENT;
2066 	}
2067 
2068 	if (drbd_md_test_flag(device->ldev, MDF_PEER_OUT_DATED))
2069 		ns.pdsk = D_OUTDATED;
2070 
2071 	rcu_read_lock();
2072 	if (ns.disk == D_CONSISTENT &&
2073 	    (ns.pdsk == D_OUTDATED || rcu_dereference(device->ldev->disk_conf)->fencing == FP_DONT_CARE))
2074 		ns.disk = D_UP_TO_DATE;
2075 
2076 	/* All tests on MDF_PRIMARY_IND, MDF_CONNECTED_IND,
2077 	   MDF_CONSISTENT and MDF_WAS_UP_TO_DATE must happen before
2078 	   this point, because drbd_request_state() modifies these
2079 	   flags. */
2080 
2081 	if (rcu_dereference(device->ldev->disk_conf)->al_updates)
2082 		device->ldev->md.flags &= ~MDF_AL_DISABLED;
2083 	else
2084 		device->ldev->md.flags |= MDF_AL_DISABLED;
2085 
2086 	rcu_read_unlock();
2087 
2088 	/* In case we are C_CONNECTED postpone any decision on the new disk
2089 	   state after the negotiation phase. */
2090 	if (device->state.conn == C_CONNECTED) {
2091 		device->new_state_tmp.i = ns.i;
2092 		ns.i = os.i;
2093 		ns.disk = D_NEGOTIATING;
2094 
2095 		/* We expect to receive up-to-date UUIDs soon.
2096 		   To avoid a race in receive_state, free p_uuid while
2097 		   holding req_lock. I.e. atomic with the state change */
2098 		kfree(device->p_uuid);
2099 		device->p_uuid = NULL;
2100 	}
2101 
2102 	rv = _drbd_set_state(device, ns, CS_VERBOSE, NULL);
2103 	spin_unlock_irq(&device->resource->req_lock);
2104 
2105 	if (rv < SS_SUCCESS)
2106 		goto force_diskless_dec;
2107 
2108 	mod_timer(&device->request_timer, jiffies + HZ);
2109 
2110 	if (device->state.role == R_PRIMARY)
2111 		device->ldev->md.uuid[UI_CURRENT] |=  (u64)1;
2112 	else
2113 		device->ldev->md.uuid[UI_CURRENT] &= ~(u64)1;
2114 
2115 	drbd_md_mark_dirty(device);
2116 	drbd_md_sync(device);
2117 
2118 	kobject_uevent(&disk_to_dev(device->vdisk)->kobj, KOBJ_CHANGE);
2119 	put_ldev(device);
2120 	conn_reconfig_done(connection);
2121 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2122 	drbd_adm_finish(&adm_ctx, info, retcode);
2123 	return 0;
2124 
2125  force_diskless_dec:
2126 	put_ldev(device);
2127  force_diskless:
2128 	drbd_force_state(device, NS(disk, D_DISKLESS));
2129 	drbd_md_sync(device);
2130  fail:
2131 	conn_reconfig_done(connection);
2132 	if (nbc) {
2133 		close_backing_dev(device, nbc->md_bdev,
2134 			  nbc->disk_conf->meta_dev_idx < 0 ?
2135 				(void *)device : (void *)drbd_m_holder,
2136 			  nbc->md_bdev != nbc->backing_bdev);
2137 		close_backing_dev(device, nbc->backing_bdev, device, true);
2138 		kfree(nbc);
2139 	}
2140 	kfree(new_disk_conf);
2141 	lc_destroy(resync_lru);
2142 	kfree(new_plan);
2143 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2144  finish:
2145 	drbd_adm_finish(&adm_ctx, info, retcode);
2146 	return 0;
2147 }
2148 
2149 static int adm_detach(struct drbd_device *device, int force)
2150 {
2151 	if (force) {
2152 		set_bit(FORCE_DETACH, &device->flags);
2153 		drbd_force_state(device, NS(disk, D_FAILED));
2154 		return SS_SUCCESS;
2155 	}
2156 
2157 	return drbd_request_detach_interruptible(device);
2158 }
2159 
2160 /* Detaching the disk is a process in multiple stages.  First we need to lock
2161  * out application IO, in-flight IO, IO stuck in drbd_al_begin_io.
2162  * Then we transition to D_DISKLESS, and wait for put_ldev() to return all
2163  * internal references as well.
2164  * Only then we have finally detached. */
2165 int drbd_adm_detach(struct sk_buff *skb, struct genl_info *info)
2166 {
2167 	struct drbd_config_context adm_ctx;
2168 	enum drbd_ret_code retcode;
2169 	struct detach_parms parms = { };
2170 	int err;
2171 
2172 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
2173 	if (!adm_ctx.reply_skb)
2174 		return retcode;
2175 	if (retcode != NO_ERROR)
2176 		goto out;
2177 
2178 	if (info->attrs[DRBD_NLA_DETACH_PARMS]) {
2179 		err = detach_parms_from_attrs(&parms, info);
2180 		if (err) {
2181 			retcode = ERR_MANDATORY_TAG;
2182 			drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
2183 			goto out;
2184 		}
2185 	}
2186 
2187 	mutex_lock(&adm_ctx.resource->adm_mutex);
2188 	retcode = adm_detach(adm_ctx.device, parms.force_detach);
2189 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2190 out:
2191 	drbd_adm_finish(&adm_ctx, info, retcode);
2192 	return 0;
2193 }
2194 
2195 static bool conn_resync_running(struct drbd_connection *connection)
2196 {
2197 	struct drbd_peer_device *peer_device;
2198 	bool rv = false;
2199 	int vnr;
2200 
2201 	rcu_read_lock();
2202 	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2203 		struct drbd_device *device = peer_device->device;
2204 		if (device->state.conn == C_SYNC_SOURCE ||
2205 		    device->state.conn == C_SYNC_TARGET ||
2206 		    device->state.conn == C_PAUSED_SYNC_S ||
2207 		    device->state.conn == C_PAUSED_SYNC_T) {
2208 			rv = true;
2209 			break;
2210 		}
2211 	}
2212 	rcu_read_unlock();
2213 
2214 	return rv;
2215 }
2216 
2217 static bool conn_ov_running(struct drbd_connection *connection)
2218 {
2219 	struct drbd_peer_device *peer_device;
2220 	bool rv = false;
2221 	int vnr;
2222 
2223 	rcu_read_lock();
2224 	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2225 		struct drbd_device *device = peer_device->device;
2226 		if (device->state.conn == C_VERIFY_S ||
2227 		    device->state.conn == C_VERIFY_T) {
2228 			rv = true;
2229 			break;
2230 		}
2231 	}
2232 	rcu_read_unlock();
2233 
2234 	return rv;
2235 }
2236 
2237 static enum drbd_ret_code
2238 _check_net_options(struct drbd_connection *connection, struct net_conf *old_net_conf, struct net_conf *new_net_conf)
2239 {
2240 	struct drbd_peer_device *peer_device;
2241 	int i;
2242 
2243 	if (old_net_conf && connection->cstate == C_WF_REPORT_PARAMS && connection->agreed_pro_version < 100) {
2244 		if (new_net_conf->wire_protocol != old_net_conf->wire_protocol)
2245 			return ERR_NEED_APV_100;
2246 
2247 		if (new_net_conf->two_primaries != old_net_conf->two_primaries)
2248 			return ERR_NEED_APV_100;
2249 
2250 		if (strcmp(new_net_conf->integrity_alg, old_net_conf->integrity_alg))
2251 			return ERR_NEED_APV_100;
2252 	}
2253 
2254 	if (!new_net_conf->two_primaries &&
2255 	    conn_highest_role(connection) == R_PRIMARY &&
2256 	    conn_highest_peer(connection) == R_PRIMARY)
2257 		return ERR_NEED_ALLOW_TWO_PRI;
2258 
2259 	if (new_net_conf->two_primaries &&
2260 	    (new_net_conf->wire_protocol != DRBD_PROT_C))
2261 		return ERR_NOT_PROTO_C;
2262 
2263 	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
2264 		struct drbd_device *device = peer_device->device;
2265 		if (get_ldev(device)) {
2266 			enum drbd_fencing_p fp = rcu_dereference(device->ldev->disk_conf)->fencing;
2267 			put_ldev(device);
2268 			if (new_net_conf->wire_protocol == DRBD_PROT_A && fp == FP_STONITH)
2269 				return ERR_STONITH_AND_PROT_A;
2270 		}
2271 		if (device->state.role == R_PRIMARY && new_net_conf->discard_my_data)
2272 			return ERR_DISCARD_IMPOSSIBLE;
2273 	}
2274 
2275 	if (new_net_conf->on_congestion != OC_BLOCK && new_net_conf->wire_protocol != DRBD_PROT_A)
2276 		return ERR_CONG_NOT_PROTO_A;
2277 
2278 	return NO_ERROR;
2279 }
2280 
2281 static enum drbd_ret_code
2282 check_net_options(struct drbd_connection *connection, struct net_conf *new_net_conf)
2283 {
2284 	enum drbd_ret_code rv;
2285 	struct drbd_peer_device *peer_device;
2286 	int i;
2287 
2288 	rcu_read_lock();
2289 	rv = _check_net_options(connection, rcu_dereference(connection->net_conf), new_net_conf);
2290 	rcu_read_unlock();
2291 
2292 	/* connection->peer_devices protected by genl_lock() here */
2293 	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
2294 		struct drbd_device *device = peer_device->device;
2295 		if (!device->bitmap) {
2296 			if (drbd_bm_init(device))
2297 				return ERR_NOMEM;
2298 		}
2299 	}
2300 
2301 	return rv;
2302 }
2303 
2304 struct crypto {
2305 	struct crypto_shash *verify_tfm;
2306 	struct crypto_shash *csums_tfm;
2307 	struct crypto_shash *cram_hmac_tfm;
2308 	struct crypto_shash *integrity_tfm;
2309 };
2310 
2311 static int
2312 alloc_shash(struct crypto_shash **tfm, char *tfm_name, int err_alg)
2313 {
2314 	if (!tfm_name[0])
2315 		return NO_ERROR;
2316 
2317 	*tfm = crypto_alloc_shash(tfm_name, 0, 0);
2318 	if (IS_ERR(*tfm)) {
2319 		*tfm = NULL;
2320 		return err_alg;
2321 	}
2322 
2323 	return NO_ERROR;
2324 }
2325 
2326 static enum drbd_ret_code
2327 alloc_crypto(struct crypto *crypto, struct net_conf *new_net_conf)
2328 {
2329 	char hmac_name[CRYPTO_MAX_ALG_NAME];
2330 	enum drbd_ret_code rv;
2331 
2332 	rv = alloc_shash(&crypto->csums_tfm, new_net_conf->csums_alg,
2333 			 ERR_CSUMS_ALG);
2334 	if (rv != NO_ERROR)
2335 		return rv;
2336 	rv = alloc_shash(&crypto->verify_tfm, new_net_conf->verify_alg,
2337 			 ERR_VERIFY_ALG);
2338 	if (rv != NO_ERROR)
2339 		return rv;
2340 	rv = alloc_shash(&crypto->integrity_tfm, new_net_conf->integrity_alg,
2341 			 ERR_INTEGRITY_ALG);
2342 	if (rv != NO_ERROR)
2343 		return rv;
2344 	if (new_net_conf->cram_hmac_alg[0] != 0) {
2345 		snprintf(hmac_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)",
2346 			 new_net_conf->cram_hmac_alg);
2347 
2348 		rv = alloc_shash(&crypto->cram_hmac_tfm, hmac_name,
2349 				 ERR_AUTH_ALG);
2350 	}
2351 
2352 	return rv;
2353 }
2354 
2355 static void free_crypto(struct crypto *crypto)
2356 {
2357 	crypto_free_shash(crypto->cram_hmac_tfm);
2358 	crypto_free_shash(crypto->integrity_tfm);
2359 	crypto_free_shash(crypto->csums_tfm);
2360 	crypto_free_shash(crypto->verify_tfm);
2361 }
2362 
2363 int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
2364 {
2365 	struct drbd_config_context adm_ctx;
2366 	enum drbd_ret_code retcode;
2367 	struct drbd_connection *connection;
2368 	struct net_conf *old_net_conf, *new_net_conf = NULL;
2369 	int err;
2370 	int ovr; /* online verify running */
2371 	int rsr; /* re-sync running */
2372 	struct crypto crypto = { };
2373 
2374 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_CONNECTION);
2375 	if (!adm_ctx.reply_skb)
2376 		return retcode;
2377 	if (retcode != NO_ERROR)
2378 		goto finish;
2379 
2380 	connection = adm_ctx.connection;
2381 	mutex_lock(&adm_ctx.resource->adm_mutex);
2382 
2383 	new_net_conf = kzalloc(sizeof(struct net_conf), GFP_KERNEL);
2384 	if (!new_net_conf) {
2385 		retcode = ERR_NOMEM;
2386 		goto out;
2387 	}
2388 
2389 	conn_reconfig_start(connection);
2390 
2391 	mutex_lock(&connection->data.mutex);
2392 	mutex_lock(&connection->resource->conf_update);
2393 	old_net_conf = connection->net_conf;
2394 
2395 	if (!old_net_conf) {
2396 		drbd_msg_put_info(adm_ctx.reply_skb, "net conf missing, try connect");
2397 		retcode = ERR_INVALID_REQUEST;
2398 		goto fail;
2399 	}
2400 
2401 	*new_net_conf = *old_net_conf;
2402 	if (should_set_defaults(info))
2403 		set_net_conf_defaults(new_net_conf);
2404 
2405 	err = net_conf_from_attrs_for_change(new_net_conf, info);
2406 	if (err && err != -ENOMSG) {
2407 		retcode = ERR_MANDATORY_TAG;
2408 		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
2409 		goto fail;
2410 	}
2411 
2412 	retcode = check_net_options(connection, new_net_conf);
2413 	if (retcode != NO_ERROR)
2414 		goto fail;
2415 
2416 	/* re-sync running */
2417 	rsr = conn_resync_running(connection);
2418 	if (rsr && strcmp(new_net_conf->csums_alg, old_net_conf->csums_alg)) {
2419 		retcode = ERR_CSUMS_RESYNC_RUNNING;
2420 		goto fail;
2421 	}
2422 
2423 	/* online verify running */
2424 	ovr = conn_ov_running(connection);
2425 	if (ovr && strcmp(new_net_conf->verify_alg, old_net_conf->verify_alg)) {
2426 		retcode = ERR_VERIFY_RUNNING;
2427 		goto fail;
2428 	}
2429 
2430 	retcode = alloc_crypto(&crypto, new_net_conf);
2431 	if (retcode != NO_ERROR)
2432 		goto fail;
2433 
2434 	rcu_assign_pointer(connection->net_conf, new_net_conf);
2435 
2436 	if (!rsr) {
2437 		crypto_free_shash(connection->csums_tfm);
2438 		connection->csums_tfm = crypto.csums_tfm;
2439 		crypto.csums_tfm = NULL;
2440 	}
2441 	if (!ovr) {
2442 		crypto_free_shash(connection->verify_tfm);
2443 		connection->verify_tfm = crypto.verify_tfm;
2444 		crypto.verify_tfm = NULL;
2445 	}
2446 
2447 	crypto_free_shash(connection->integrity_tfm);
2448 	connection->integrity_tfm = crypto.integrity_tfm;
2449 	if (connection->cstate >= C_WF_REPORT_PARAMS && connection->agreed_pro_version >= 100)
2450 		/* Do this without trying to take connection->data.mutex again.  */
2451 		__drbd_send_protocol(connection, P_PROTOCOL_UPDATE);
2452 
2453 	crypto_free_shash(connection->cram_hmac_tfm);
2454 	connection->cram_hmac_tfm = crypto.cram_hmac_tfm;
2455 
2456 	mutex_unlock(&connection->resource->conf_update);
2457 	mutex_unlock(&connection->data.mutex);
2458 	kvfree_rcu_mightsleep(old_net_conf);
2459 
2460 	if (connection->cstate >= C_WF_REPORT_PARAMS) {
2461 		struct drbd_peer_device *peer_device;
2462 		int vnr;
2463 
2464 		idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
2465 			drbd_send_sync_param(peer_device);
2466 	}
2467 
2468 	goto done;
2469 
2470  fail:
2471 	mutex_unlock(&connection->resource->conf_update);
2472 	mutex_unlock(&connection->data.mutex);
2473 	free_crypto(&crypto);
2474 	kfree(new_net_conf);
2475  done:
2476 	conn_reconfig_done(connection);
2477  out:
2478 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2479  finish:
2480 	drbd_adm_finish(&adm_ctx, info, retcode);
2481 	return 0;
2482 }
2483 
2484 static void connection_to_info(struct connection_info *info,
2485 			       struct drbd_connection *connection)
2486 {
2487 	info->conn_connection_state = connection->cstate;
2488 	info->conn_role = conn_highest_peer(connection);
2489 }
2490 
2491 static void peer_device_to_info(struct peer_device_info *info,
2492 				struct drbd_peer_device *peer_device)
2493 {
2494 	struct drbd_device *device = peer_device->device;
2495 
2496 	info->peer_repl_state =
2497 		max_t(enum drbd_conns, C_WF_REPORT_PARAMS, device->state.conn);
2498 	info->peer_disk_state = device->state.pdsk;
2499 	info->peer_resync_susp_user = device->state.user_isp;
2500 	info->peer_resync_susp_peer = device->state.peer_isp;
2501 	info->peer_resync_susp_dependency = device->state.aftr_isp;
2502 }
2503 
2504 int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
2505 {
2506 	struct connection_info connection_info;
2507 	enum drbd_notification_type flags;
2508 	unsigned int peer_devices = 0;
2509 	struct drbd_config_context adm_ctx;
2510 	struct drbd_peer_device *peer_device;
2511 	struct net_conf *old_net_conf, *new_net_conf = NULL;
2512 	struct crypto crypto = { };
2513 	struct drbd_resource *resource;
2514 	struct drbd_connection *connection;
2515 	enum drbd_ret_code retcode;
2516 	enum drbd_state_rv rv;
2517 	int i;
2518 	int err;
2519 
2520 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);
2521 
2522 	if (!adm_ctx.reply_skb)
2523 		return retcode;
2524 	if (retcode != NO_ERROR)
2525 		goto out;
2526 	if (!(adm_ctx.my_addr && adm_ctx.peer_addr)) {
2527 		drbd_msg_put_info(adm_ctx.reply_skb, "connection endpoint(s) missing");
2528 		retcode = ERR_INVALID_REQUEST;
2529 		goto out;
2530 	}
2531 
2532 	/* No need for _rcu here. All reconfiguration is
2533 	 * strictly serialized on genl_lock(). We are protected against
2534 	 * concurrent reconfiguration/addition/deletion */
2535 	for_each_resource(resource, &drbd_resources) {
2536 		for_each_connection(connection, resource) {
2537 			if (nla_len(adm_ctx.my_addr) == connection->my_addr_len &&
2538 			    !memcmp(nla_data(adm_ctx.my_addr), &connection->my_addr,
2539 				    connection->my_addr_len)) {
2540 				retcode = ERR_LOCAL_ADDR;
2541 				goto out;
2542 			}
2543 
2544 			if (nla_len(adm_ctx.peer_addr) == connection->peer_addr_len &&
2545 			    !memcmp(nla_data(adm_ctx.peer_addr), &connection->peer_addr,
2546 				    connection->peer_addr_len)) {
2547 				retcode = ERR_PEER_ADDR;
2548 				goto out;
2549 			}
2550 		}
2551 	}
2552 
2553 	mutex_lock(&adm_ctx.resource->adm_mutex);
2554 	connection = first_connection(adm_ctx.resource);
2555 	conn_reconfig_start(connection);
2556 
2557 	if (connection->cstate > C_STANDALONE) {
2558 		retcode = ERR_NET_CONFIGURED;
2559 		goto fail;
2560 	}
2561 
2562 	/* allocation not in the IO path, drbdsetup / netlink process context */
2563 	new_net_conf = kzalloc(sizeof(*new_net_conf), GFP_KERNEL);
2564 	if (!new_net_conf) {
2565 		retcode = ERR_NOMEM;
2566 		goto fail;
2567 	}
2568 
2569 	set_net_conf_defaults(new_net_conf);
2570 
2571 	err = net_conf_from_attrs(new_net_conf, info);
2572 	if (err && err != -ENOMSG) {
2573 		retcode = ERR_MANDATORY_TAG;
2574 		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
2575 		goto fail;
2576 	}
2577 
2578 	retcode = check_net_options(connection, new_net_conf);
2579 	if (retcode != NO_ERROR)
2580 		goto fail;
2581 
2582 	retcode = alloc_crypto(&crypto, new_net_conf);
2583 	if (retcode != NO_ERROR)
2584 		goto fail;
2585 
2586 	((char *)new_net_conf->shared_secret)[SHARED_SECRET_MAX-1] = 0;
2587 
2588 	drbd_flush_workqueue(&connection->sender_work);
2589 
2590 	mutex_lock(&adm_ctx.resource->conf_update);
2591 	old_net_conf = connection->net_conf;
2592 	if (old_net_conf) {
2593 		retcode = ERR_NET_CONFIGURED;
2594 		mutex_unlock(&adm_ctx.resource->conf_update);
2595 		goto fail;
2596 	}
2597 	rcu_assign_pointer(connection->net_conf, new_net_conf);
2598 
2599 	conn_free_crypto(connection);
2600 	connection->cram_hmac_tfm = crypto.cram_hmac_tfm;
2601 	connection->integrity_tfm = crypto.integrity_tfm;
2602 	connection->csums_tfm = crypto.csums_tfm;
2603 	connection->verify_tfm = crypto.verify_tfm;
2604 
2605 	connection->my_addr_len = nla_len(adm_ctx.my_addr);
2606 	memcpy(&connection->my_addr, nla_data(adm_ctx.my_addr), connection->my_addr_len);
2607 	connection->peer_addr_len = nla_len(adm_ctx.peer_addr);
2608 	memcpy(&connection->peer_addr, nla_data(adm_ctx.peer_addr), connection->peer_addr_len);
2609 
2610 	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
2611 		peer_devices++;
2612 	}
2613 
2614 	connection_to_info(&connection_info, connection);
2615 	flags = (peer_devices--) ? NOTIFY_CONTINUES : 0;
2616 	mutex_lock(&notification_mutex);
2617 	notify_connection_state(NULL, 0, connection, &connection_info, NOTIFY_CREATE | flags);
2618 	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
2619 		struct peer_device_info peer_device_info;
2620 
2621 		peer_device_to_info(&peer_device_info, peer_device);
2622 		flags = (peer_devices--) ? NOTIFY_CONTINUES : 0;
2623 		notify_peer_device_state(NULL, 0, peer_device, &peer_device_info, NOTIFY_CREATE | flags);
2624 	}
2625 	mutex_unlock(&notification_mutex);
2626 	mutex_unlock(&adm_ctx.resource->conf_update);
2627 
2628 	rcu_read_lock();
2629 	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
2630 		struct drbd_device *device = peer_device->device;
2631 		device->send_cnt = 0;
2632 		device->recv_cnt = 0;
2633 	}
2634 	rcu_read_unlock();
2635 
2636 	rv = conn_request_state(connection, NS(conn, C_UNCONNECTED), CS_VERBOSE);
2637 
2638 	conn_reconfig_done(connection);
2639 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2640 	drbd_adm_finish(&adm_ctx, info, rv);
2641 	return 0;
2642 
2643 fail:
2644 	free_crypto(&crypto);
2645 	kfree(new_net_conf);
2646 
2647 	conn_reconfig_done(connection);
2648 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2649 out:
2650 	drbd_adm_finish(&adm_ctx, info, retcode);
2651 	return 0;
2652 }
2653 
2654 static enum drbd_state_rv conn_try_disconnect(struct drbd_connection *connection, bool force)
2655 {
2656 	enum drbd_conns cstate;
2657 	enum drbd_state_rv rv;
2658 
2659 repeat:
2660 	rv = conn_request_state(connection, NS(conn, C_DISCONNECTING),
2661 			force ? CS_HARD : 0);
2662 
2663 	switch (rv) {
2664 	case SS_NOTHING_TO_DO:
2665 		break;
2666 	case SS_ALREADY_STANDALONE:
2667 		return SS_SUCCESS;
2668 	case SS_PRIMARY_NOP:
2669 		/* Our state checking code wants to see the peer outdated. */
2670 		rv = conn_request_state(connection, NS2(conn, C_DISCONNECTING, pdsk, D_OUTDATED), 0);
2671 
2672 		if (rv == SS_OUTDATE_WO_CONN) /* lost connection before graceful disconnect succeeded */
2673 			rv = conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_VERBOSE);
2674 
2675 		break;
2676 	case SS_CW_FAILED_BY_PEER:
2677 		spin_lock_irq(&connection->resource->req_lock);
2678 		cstate = connection->cstate;
2679 		spin_unlock_irq(&connection->resource->req_lock);
2680 		if (cstate <= C_WF_CONNECTION)
2681 			goto repeat;
2682 		/* The peer probably wants to see us outdated. */
2683 		rv = conn_request_state(connection, NS2(conn, C_DISCONNECTING,
2684 							disk, D_OUTDATED), 0);
2685 		if (rv == SS_IS_DISKLESS || rv == SS_LOWER_THAN_OUTDATED) {
2686 			rv = conn_request_state(connection, NS(conn, C_DISCONNECTING),
2687 					CS_HARD);
2688 		}
2689 		break;
2690 	default:;
2691 		/* no special handling necessary */
2692 	}
2693 
2694 	if (rv >= SS_SUCCESS) {
2695 		enum drbd_state_rv rv2;
2696 		/* No one else can reconfigure the network while I am here.
2697 		 * The state handling only uses drbd_thread_stop_nowait(),
2698 		 * we want to really wait here until the receiver is no more.
2699 		 */
2700 		drbd_thread_stop(&connection->receiver);
2701 
2702 		/* Race breaker.  This additional state change request may be
2703 		 * necessary, if this was a forced disconnect during a receiver
2704 		 * restart.  We may have "killed" the receiver thread just
2705 		 * after drbd_receiver() returned.  Typically, we should be
2706 		 * C_STANDALONE already, now, and this becomes a no-op.
2707 		 */
2708 		rv2 = conn_request_state(connection, NS(conn, C_STANDALONE),
2709 				CS_VERBOSE | CS_HARD);
2710 		if (rv2 < SS_SUCCESS)
2711 			drbd_err(connection,
2712 				"unexpected rv2=%d in conn_try_disconnect()\n",
2713 				rv2);
2714 		/* Unlike in DRBD 9, the state engine has generated
2715 		 * NOTIFY_DESTROY events before clearing connection->net_conf. */
2716 	}
2717 	return rv;
2718 }
2719 
2720 int drbd_adm_disconnect(struct sk_buff *skb, struct genl_info *info)
2721 {
2722 	struct drbd_config_context adm_ctx;
2723 	struct disconnect_parms parms;
2724 	struct drbd_connection *connection;
2725 	enum drbd_state_rv rv;
2726 	enum drbd_ret_code retcode;
2727 	int err;
2728 
2729 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_CONNECTION);
2730 	if (!adm_ctx.reply_skb)
2731 		return retcode;
2732 	if (retcode != NO_ERROR)
2733 		goto fail;
2734 
2735 	connection = adm_ctx.connection;
2736 	memset(&parms, 0, sizeof(parms));
2737 	if (info->attrs[DRBD_NLA_DISCONNECT_PARMS]) {
2738 		err = disconnect_parms_from_attrs(&parms, info);
2739 		if (err) {
2740 			retcode = ERR_MANDATORY_TAG;
2741 			drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
2742 			goto fail;
2743 		}
2744 	}
2745 
2746 	mutex_lock(&adm_ctx.resource->adm_mutex);
2747 	rv = conn_try_disconnect(connection, parms.force_disconnect);
2748 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2749 	if (rv < SS_SUCCESS) {
2750 		drbd_adm_finish(&adm_ctx, info, rv);
2751 		return 0;
2752 	}
2753 	retcode = NO_ERROR;
2754  fail:
2755 	drbd_adm_finish(&adm_ctx, info, retcode);
2756 	return 0;
2757 }
2758 
2759 void resync_after_online_grow(struct drbd_device *device)
2760 {
2761 	int iass; /* I am sync source */
2762 
2763 	drbd_info(device, "Resync of new storage after online grow\n");
2764 	if (device->state.role != device->state.peer)
2765 		iass = (device->state.role == R_PRIMARY);
2766 	else
2767 		iass = test_bit(RESOLVE_CONFLICTS, &first_peer_device(device)->connection->flags);
2768 
2769 	if (iass)
2770 		drbd_start_resync(device, C_SYNC_SOURCE);
2771 	else
2772 		_drbd_request_state(device, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE + CS_SERIALIZE);
2773 }
2774 
2775 int drbd_adm_resize(struct sk_buff *skb, struct genl_info *info)
2776 {
2777 	struct drbd_config_context adm_ctx;
2778 	struct disk_conf *old_disk_conf, *new_disk_conf = NULL;
2779 	struct resize_parms rs;
2780 	struct drbd_device *device;
2781 	enum drbd_ret_code retcode;
2782 	enum determine_dev_size dd;
2783 	bool change_al_layout = false;
2784 	enum dds_flags ddsf;
2785 	sector_t u_size;
2786 	int err;
2787 
2788 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
2789 	if (!adm_ctx.reply_skb)
2790 		return retcode;
2791 	if (retcode != NO_ERROR)
2792 		goto finish;
2793 
2794 	mutex_lock(&adm_ctx.resource->adm_mutex);
2795 	device = adm_ctx.device;
2796 	if (!get_ldev(device)) {
2797 		retcode = ERR_NO_DISK;
2798 		goto fail;
2799 	}
2800 
2801 	memset(&rs, 0, sizeof(struct resize_parms));
2802 	rs.al_stripes = device->ldev->md.al_stripes;
2803 	rs.al_stripe_size = device->ldev->md.al_stripe_size_4k * 4;
2804 	if (info->attrs[DRBD_NLA_RESIZE_PARMS]) {
2805 		err = resize_parms_from_attrs(&rs, info);
2806 		if (err) {
2807 			retcode = ERR_MANDATORY_TAG;
2808 			drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
2809 			goto fail_ldev;
2810 		}
2811 	}
2812 
2813 	if (device->state.conn > C_CONNECTED) {
2814 		retcode = ERR_RESIZE_RESYNC;
2815 		goto fail_ldev;
2816 	}
2817 
2818 	if (device->state.role == R_SECONDARY &&
2819 	    device->state.peer == R_SECONDARY) {
2820 		retcode = ERR_NO_PRIMARY;
2821 		goto fail_ldev;
2822 	}
2823 
2824 	if (rs.no_resync && first_peer_device(device)->connection->agreed_pro_version < 93) {
2825 		retcode = ERR_NEED_APV_93;
2826 		goto fail_ldev;
2827 	}
2828 
2829 	rcu_read_lock();
2830 	u_size = rcu_dereference(device->ldev->disk_conf)->disk_size;
2831 	rcu_read_unlock();
2832 	if (u_size != (sector_t)rs.resize_size) {
2833 		new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
2834 		if (!new_disk_conf) {
2835 			retcode = ERR_NOMEM;
2836 			goto fail_ldev;
2837 		}
2838 	}
2839 
2840 	if (device->ldev->md.al_stripes != rs.al_stripes ||
2841 	    device->ldev->md.al_stripe_size_4k != rs.al_stripe_size / 4) {
2842 		u32 al_size_k = rs.al_stripes * rs.al_stripe_size;
2843 
2844 		if (al_size_k > (16 * 1024 * 1024)) {
2845 			retcode = ERR_MD_LAYOUT_TOO_BIG;
2846 			goto fail_ldev;
2847 		}
2848 
2849 		if (al_size_k < MD_32kB_SECT/2) {
2850 			retcode = ERR_MD_LAYOUT_TOO_SMALL;
2851 			goto fail_ldev;
2852 		}
2853 
2854 		if (device->state.conn != C_CONNECTED && !rs.resize_force) {
2855 			retcode = ERR_MD_LAYOUT_CONNECTED;
2856 			goto fail_ldev;
2857 		}
2858 
2859 		change_al_layout = true;
2860 	}
2861 
2862 	if (device->ldev->known_size != drbd_get_capacity(device->ldev->backing_bdev))
2863 		device->ldev->known_size = drbd_get_capacity(device->ldev->backing_bdev);
2864 
2865 	if (new_disk_conf) {
2866 		mutex_lock(&device->resource->conf_update);
2867 		old_disk_conf = device->ldev->disk_conf;
2868 		*new_disk_conf = *old_disk_conf;
2869 		new_disk_conf->disk_size = (sector_t)rs.resize_size;
2870 		rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
2871 		mutex_unlock(&device->resource->conf_update);
2872 		kvfree_rcu_mightsleep(old_disk_conf);
2873 		new_disk_conf = NULL;
2874 	}
2875 
2876 	ddsf = (rs.resize_force ? DDSF_FORCED : 0) | (rs.no_resync ? DDSF_NO_RESYNC : 0);
2877 	dd = drbd_determine_dev_size(device, ddsf, change_al_layout ? &rs : NULL);
2878 	drbd_md_sync(device);
2879 	put_ldev(device);
2880 	if (dd == DS_ERROR) {
2881 		retcode = ERR_NOMEM_BITMAP;
2882 		goto fail;
2883 	} else if (dd == DS_ERROR_SPACE_MD) {
2884 		retcode = ERR_MD_LAYOUT_NO_FIT;
2885 		goto fail;
2886 	} else if (dd == DS_ERROR_SHRINK) {
2887 		retcode = ERR_IMPLICIT_SHRINK;
2888 		goto fail;
2889 	}
2890 
2891 	if (device->state.conn == C_CONNECTED) {
2892 		if (dd == DS_GREW)
2893 			set_bit(RESIZE_PENDING, &device->flags);
2894 
2895 		drbd_send_uuids(first_peer_device(device));
2896 		drbd_send_sizes(first_peer_device(device), 1, ddsf);
2897 	}
2898 
2899  fail:
2900 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2901  finish:
2902 	drbd_adm_finish(&adm_ctx, info, retcode);
2903 	return 0;
2904 
2905  fail_ldev:
2906 	put_ldev(device);
2907 	kfree(new_disk_conf);
2908 	goto fail;
2909 }
2910 
2911 int drbd_adm_resource_opts(struct sk_buff *skb, struct genl_info *info)
2912 {
2913 	struct drbd_config_context adm_ctx;
2914 	enum drbd_ret_code retcode;
2915 	struct res_opts res_opts;
2916 	int err;
2917 
2918 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);
2919 	if (!adm_ctx.reply_skb)
2920 		return retcode;
2921 	if (retcode != NO_ERROR)
2922 		goto fail;
2923 
2924 	res_opts = adm_ctx.resource->res_opts;
2925 	if (should_set_defaults(info))
2926 		set_res_opts_defaults(&res_opts);
2927 
2928 	err = res_opts_from_attrs(&res_opts, info);
2929 	if (err && err != -ENOMSG) {
2930 		retcode = ERR_MANDATORY_TAG;
2931 		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
2932 		goto fail;
2933 	}
2934 
2935 	mutex_lock(&adm_ctx.resource->adm_mutex);
2936 	err = set_resource_options(adm_ctx.resource, &res_opts);
2937 	if (err) {
2938 		retcode = ERR_INVALID_REQUEST;
2939 		if (err == -ENOMEM)
2940 			retcode = ERR_NOMEM;
2941 	}
2942 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2943 
2944 fail:
2945 	drbd_adm_finish(&adm_ctx, info, retcode);
2946 	return 0;
2947 }
2948 
2949 int drbd_adm_invalidate(struct sk_buff *skb, struct genl_info *info)
2950 {
2951 	struct drbd_config_context adm_ctx;
2952 	struct drbd_device *device;
2953 	int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
2954 
2955 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
2956 	if (!adm_ctx.reply_skb)
2957 		return retcode;
2958 	if (retcode != NO_ERROR)
2959 		goto out;
2960 
2961 	device = adm_ctx.device;
2962 	if (!get_ldev(device)) {
2963 		retcode = ERR_NO_DISK;
2964 		goto out;
2965 	}
2966 
2967 	mutex_lock(&adm_ctx.resource->adm_mutex);
2968 
2969 	/* If there is still bitmap IO pending, probably because of a previous
2970 	 * resync just being finished, wait for it before requesting a new resync.
2971 	 * Also wait for it's after_state_ch(). */
2972 	drbd_suspend_io(device);
2973 	wait_event(device->misc_wait, !test_bit(BITMAP_IO, &device->flags));
2974 	drbd_flush_workqueue(&first_peer_device(device)->connection->sender_work);
2975 
2976 	/* If we happen to be C_STANDALONE R_SECONDARY, just change to
2977 	 * D_INCONSISTENT, and set all bits in the bitmap.  Otherwise,
2978 	 * try to start a resync handshake as sync target for full sync.
2979 	 */
2980 	if (device->state.conn == C_STANDALONE && device->state.role == R_SECONDARY) {
2981 		retcode = drbd_request_state(device, NS(disk, D_INCONSISTENT));
2982 		if (retcode >= SS_SUCCESS) {
2983 			if (drbd_bitmap_io(device, &drbd_bmio_set_n_write,
2984 				"set_n_write from invalidate", BM_LOCKED_MASK, NULL))
2985 				retcode = ERR_IO_MD_DISK;
2986 		}
2987 	} else
2988 		retcode = drbd_request_state(device, NS(conn, C_STARTING_SYNC_T));
2989 	drbd_resume_io(device);
2990 	mutex_unlock(&adm_ctx.resource->adm_mutex);
2991 	put_ldev(device);
2992 out:
2993 	drbd_adm_finish(&adm_ctx, info, retcode);
2994 	return 0;
2995 }
2996 
2997 static int drbd_adm_simple_request_state(struct sk_buff *skb, struct genl_info *info,
2998 		union drbd_state mask, union drbd_state val)
2999 {
3000 	struct drbd_config_context adm_ctx;
3001 	enum drbd_ret_code retcode;
3002 
3003 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
3004 	if (!adm_ctx.reply_skb)
3005 		return retcode;
3006 	if (retcode != NO_ERROR)
3007 		goto out;
3008 
3009 	mutex_lock(&adm_ctx.resource->adm_mutex);
3010 	retcode = drbd_request_state(adm_ctx.device, mask, val);
3011 	mutex_unlock(&adm_ctx.resource->adm_mutex);
3012 out:
3013 	drbd_adm_finish(&adm_ctx, info, retcode);
3014 	return 0;
3015 }
3016 
3017 static int drbd_bmio_set_susp_al(struct drbd_device *device,
3018 		struct drbd_peer_device *peer_device) __must_hold(local)
3019 {
3020 	int rv;
3021 
3022 	rv = drbd_bmio_set_n_write(device, peer_device);
3023 	drbd_suspend_al(device);
3024 	return rv;
3025 }
3026 
3027 int drbd_adm_invalidate_peer(struct sk_buff *skb, struct genl_info *info)
3028 {
3029 	struct drbd_config_context adm_ctx;
3030 	int retcode; /* drbd_ret_code, drbd_state_rv */
3031 	struct drbd_device *device;
3032 
3033 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
3034 	if (!adm_ctx.reply_skb)
3035 		return retcode;
3036 	if (retcode != NO_ERROR)
3037 		goto out;
3038 
3039 	device = adm_ctx.device;
3040 	if (!get_ldev(device)) {
3041 		retcode = ERR_NO_DISK;
3042 		goto out;
3043 	}
3044 
3045 	mutex_lock(&adm_ctx.resource->adm_mutex);
3046 
3047 	/* If there is still bitmap IO pending, probably because of a previous
3048 	 * resync just being finished, wait for it before requesting a new resync.
3049 	 * Also wait for it's after_state_ch(). */
3050 	drbd_suspend_io(device);
3051 	wait_event(device->misc_wait, !test_bit(BITMAP_IO, &device->flags));
3052 	drbd_flush_workqueue(&first_peer_device(device)->connection->sender_work);
3053 
3054 	/* If we happen to be C_STANDALONE R_PRIMARY, just set all bits
3055 	 * in the bitmap.  Otherwise, try to start a resync handshake
3056 	 * as sync source for full sync.
3057 	 */
3058 	if (device->state.conn == C_STANDALONE && device->state.role == R_PRIMARY) {
3059 		/* The peer will get a resync upon connect anyways. Just make that
3060 		   into a full resync. */
3061 		retcode = drbd_request_state(device, NS(pdsk, D_INCONSISTENT));
3062 		if (retcode >= SS_SUCCESS) {
3063 			if (drbd_bitmap_io(device, &drbd_bmio_set_susp_al,
3064 				"set_n_write from invalidate_peer",
3065 				BM_LOCKED_SET_ALLOWED, NULL))
3066 				retcode = ERR_IO_MD_DISK;
3067 		}
3068 	} else
3069 		retcode = drbd_request_state(device, NS(conn, C_STARTING_SYNC_S));
3070 	drbd_resume_io(device);
3071 	mutex_unlock(&adm_ctx.resource->adm_mutex);
3072 	put_ldev(device);
3073 out:
3074 	drbd_adm_finish(&adm_ctx, info, retcode);
3075 	return 0;
3076 }
3077 
3078 int drbd_adm_pause_sync(struct sk_buff *skb, struct genl_info *info)
3079 {
3080 	struct drbd_config_context adm_ctx;
3081 	enum drbd_ret_code retcode;
3082 
3083 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
3084 	if (!adm_ctx.reply_skb)
3085 		return retcode;
3086 	if (retcode != NO_ERROR)
3087 		goto out;
3088 
3089 	mutex_lock(&adm_ctx.resource->adm_mutex);
3090 	if (drbd_request_state(adm_ctx.device, NS(user_isp, 1)) == SS_NOTHING_TO_DO)
3091 		retcode = ERR_PAUSE_IS_SET;
3092 	mutex_unlock(&adm_ctx.resource->adm_mutex);
3093 out:
3094 	drbd_adm_finish(&adm_ctx, info, retcode);
3095 	return 0;
3096 }
3097 
3098 int drbd_adm_resume_sync(struct sk_buff *skb, struct genl_info *info)
3099 {
3100 	struct drbd_config_context adm_ctx;
3101 	union drbd_dev_state s;
3102 	enum drbd_ret_code retcode;
3103 
3104 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
3105 	if (!adm_ctx.reply_skb)
3106 		return retcode;
3107 	if (retcode != NO_ERROR)
3108 		goto out;
3109 
3110 	mutex_lock(&adm_ctx.resource->adm_mutex);
3111 	if (drbd_request_state(adm_ctx.device, NS(user_isp, 0)) == SS_NOTHING_TO_DO) {
3112 		s = adm_ctx.device->state;
3113 		if (s.conn == C_PAUSED_SYNC_S || s.conn == C_PAUSED_SYNC_T) {
3114 			retcode = s.aftr_isp ? ERR_PIC_AFTER_DEP :
3115 				  s.peer_isp ? ERR_PIC_PEER_DEP : ERR_PAUSE_IS_CLEAR;
3116 		} else {
3117 			retcode = ERR_PAUSE_IS_CLEAR;
3118 		}
3119 	}
3120 	mutex_unlock(&adm_ctx.resource->adm_mutex);
3121 out:
3122 	drbd_adm_finish(&adm_ctx, info, retcode);
3123 	return 0;
3124 }
3125 
3126 int drbd_adm_suspend_io(struct sk_buff *skb, struct genl_info *info)
3127 {
3128 	return drbd_adm_simple_request_state(skb, info, NS(susp, 1));
3129 }
3130 
3131 int drbd_adm_resume_io(struct sk_buff *skb, struct genl_info *info)
3132 {
3133 	struct drbd_config_context adm_ctx;
3134 	struct drbd_device *device;
3135 	int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
3136 
3137 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
3138 	if (!adm_ctx.reply_skb)
3139 		return retcode;
3140 	if (retcode != NO_ERROR)
3141 		goto out;
3142 
3143 	mutex_lock(&adm_ctx.resource->adm_mutex);
3144 	device = adm_ctx.device;
3145 	if (test_bit(NEW_CUR_UUID, &device->flags)) {
3146 		if (get_ldev_if_state(device, D_ATTACHING)) {
3147 			drbd_uuid_new_current(device);
3148 			put_ldev(device);
3149 		} else {
3150 			/* This is effectively a multi-stage "forced down".
3151 			 * The NEW_CUR_UUID bit is supposedly only set, if we
3152 			 * lost the replication connection, and are configured
3153 			 * to freeze IO and wait for some fence-peer handler.
3154 			 * So we still don't have a replication connection.
3155 			 * And now we don't have a local disk either.  After
3156 			 * resume, we will fail all pending and new IO, because
3157 			 * we don't have any data anymore.  Which means we will
3158 			 * eventually be able to terminate all users of this
3159 			 * device, and then take it down.  By bumping the
3160 			 * "effective" data uuid, we make sure that you really
3161 			 * need to tear down before you reconfigure, we will
3162 			 * the refuse to re-connect or re-attach (because no
3163 			 * matching real data uuid exists).
3164 			 */
3165 			u64 val;
3166 			get_random_bytes(&val, sizeof(u64));
3167 			drbd_set_ed_uuid(device, val);
3168 			drbd_warn(device, "Resumed without access to data; please tear down before attempting to re-configure.\n");
3169 		}
3170 		clear_bit(NEW_CUR_UUID, &device->flags);
3171 	}
3172 	drbd_suspend_io(device);
3173 	retcode = drbd_request_state(device, NS3(susp, 0, susp_nod, 0, susp_fen, 0));
3174 	if (retcode == SS_SUCCESS) {
3175 		if (device->state.conn < C_CONNECTED)
3176 			tl_clear(first_peer_device(device)->connection);
3177 		if (device->state.disk == D_DISKLESS || device->state.disk == D_FAILED)
3178 			tl_restart(first_peer_device(device)->connection, FAIL_FROZEN_DISK_IO);
3179 	}
3180 	drbd_resume_io(device);
3181 	mutex_unlock(&adm_ctx.resource->adm_mutex);
3182 out:
3183 	drbd_adm_finish(&adm_ctx, info, retcode);
3184 	return 0;
3185 }
3186 
3187 int drbd_adm_outdate(struct sk_buff *skb, struct genl_info *info)
3188 {
3189 	return drbd_adm_simple_request_state(skb, info, NS(disk, D_OUTDATED));
3190 }
3191 
3192 static int nla_put_drbd_cfg_context(struct sk_buff *skb,
3193 				    struct drbd_resource *resource,
3194 				    struct drbd_connection *connection,
3195 				    struct drbd_device *device)
3196 {
3197 	struct nlattr *nla;
3198 	nla = nla_nest_start_noflag(skb, DRBD_NLA_CFG_CONTEXT);
3199 	if (!nla)
3200 		goto nla_put_failure;
3201 	if (device &&
3202 	    nla_put_u32(skb, T_ctx_volume, device->vnr))
3203 		goto nla_put_failure;
3204 	if (nla_put_string(skb, T_ctx_resource_name, resource->name))
3205 		goto nla_put_failure;
3206 	if (connection) {
3207 		if (connection->my_addr_len &&
3208 		    nla_put(skb, T_ctx_my_addr, connection->my_addr_len, &connection->my_addr))
3209 			goto nla_put_failure;
3210 		if (connection->peer_addr_len &&
3211 		    nla_put(skb, T_ctx_peer_addr, connection->peer_addr_len, &connection->peer_addr))
3212 			goto nla_put_failure;
3213 	}
3214 	nla_nest_end(skb, nla);
3215 	return 0;
3216 
3217 nla_put_failure:
3218 	if (nla)
3219 		nla_nest_cancel(skb, nla);
3220 	return -EMSGSIZE;
3221 }
3222 
3223 /*
3224  * The generic netlink dump callbacks are called outside the genl_lock(), so
3225  * they cannot use the simple attribute parsing code which uses global
3226  * attribute tables.
3227  */
3228 static struct nlattr *find_cfg_context_attr(const struct nlmsghdr *nlh, int attr)
3229 {
3230 	const unsigned hdrlen = GENL_HDRLEN + GENL_MAGIC_FAMILY_HDRSZ;
3231 	const int maxtype = ARRAY_SIZE(drbd_cfg_context_nl_policy) - 1;
3232 	struct nlattr *nla;
3233 
3234 	nla = nla_find(nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen),
3235 		       DRBD_NLA_CFG_CONTEXT);
3236 	if (!nla)
3237 		return NULL;
3238 	return drbd_nla_find_nested(maxtype, nla, __nla_type(attr));
3239 }
3240 
3241 static void resource_to_info(struct resource_info *, struct drbd_resource *);
3242 
3243 int drbd_adm_dump_resources(struct sk_buff *skb, struct netlink_callback *cb)
3244 {
3245 	struct drbd_genlmsghdr *dh;
3246 	struct drbd_resource *resource;
3247 	struct resource_info resource_info;
3248 	struct resource_statistics resource_statistics;
3249 	int err;
3250 
3251 	rcu_read_lock();
3252 	if (cb->args[0]) {
3253 		for_each_resource_rcu(resource, &drbd_resources)
3254 			if (resource == (struct drbd_resource *)cb->args[0])
3255 				goto found_resource;
3256 		err = 0;  /* resource was probably deleted */
3257 		goto out;
3258 	}
3259 	resource = list_entry(&drbd_resources,
3260 			      struct drbd_resource, resources);
3261 
3262 found_resource:
3263 	list_for_each_entry_continue_rcu(resource, &drbd_resources, resources) {
3264 		goto put_result;
3265 	}
3266 	err = 0;
3267 	goto out;
3268 
3269 put_result:
3270 	dh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
3271 			cb->nlh->nlmsg_seq, &drbd_genl_family,
3272 			NLM_F_MULTI, DRBD_ADM_GET_RESOURCES);
3273 	err = -ENOMEM;
3274 	if (!dh)
3275 		goto out;
3276 	dh->minor = -1U;
3277 	dh->ret_code = NO_ERROR;
3278 	err = nla_put_drbd_cfg_context(skb, resource, NULL, NULL);
3279 	if (err)
3280 		goto out;
3281 	err = res_opts_to_skb(skb, &resource->res_opts, !capable(CAP_SYS_ADMIN));
3282 	if (err)
3283 		goto out;
3284 	resource_to_info(&resource_info, resource);
3285 	err = resource_info_to_skb(skb, &resource_info, !capable(CAP_SYS_ADMIN));
3286 	if (err)
3287 		goto out;
3288 	resource_statistics.res_stat_write_ordering = resource->write_ordering;
3289 	err = resource_statistics_to_skb(skb, &resource_statistics, !capable(CAP_SYS_ADMIN));
3290 	if (err)
3291 		goto out;
3292 	cb->args[0] = (long)resource;
3293 	genlmsg_end(skb, dh);
3294 	err = 0;
3295 
3296 out:
3297 	rcu_read_unlock();
3298 	if (err)
3299 		return err;
3300 	return skb->len;
3301 }
3302 
3303 static void device_to_statistics(struct device_statistics *s,
3304 				 struct drbd_device *device)
3305 {
3306 	memset(s, 0, sizeof(*s));
3307 	s->dev_upper_blocked = !may_inc_ap_bio(device);
3308 	if (get_ldev(device)) {
3309 		struct drbd_md *md = &device->ldev->md;
3310 		u64 *history_uuids = (u64 *)s->history_uuids;
3311 		int n;
3312 
3313 		spin_lock_irq(&md->uuid_lock);
3314 		s->dev_current_uuid = md->uuid[UI_CURRENT];
3315 		BUILD_BUG_ON(sizeof(s->history_uuids) < UI_HISTORY_END - UI_HISTORY_START + 1);
3316 		for (n = 0; n < UI_HISTORY_END - UI_HISTORY_START + 1; n++)
3317 			history_uuids[n] = md->uuid[UI_HISTORY_START + n];
3318 		for (; n < HISTORY_UUIDS; n++)
3319 			history_uuids[n] = 0;
3320 		s->history_uuids_len = HISTORY_UUIDS;
3321 		spin_unlock_irq(&md->uuid_lock);
3322 
3323 		s->dev_disk_flags = md->flags;
3324 		put_ldev(device);
3325 	}
3326 	s->dev_size = get_capacity(device->vdisk);
3327 	s->dev_read = device->read_cnt;
3328 	s->dev_write = device->writ_cnt;
3329 	s->dev_al_writes = device->al_writ_cnt;
3330 	s->dev_bm_writes = device->bm_writ_cnt;
3331 	s->dev_upper_pending = atomic_read(&device->ap_bio_cnt);
3332 	s->dev_lower_pending = atomic_read(&device->local_cnt);
3333 	s->dev_al_suspended = test_bit(AL_SUSPENDED, &device->flags);
3334 	s->dev_exposed_data_uuid = device->ed_uuid;
3335 }
3336 
3337 static int put_resource_in_arg0(struct netlink_callback *cb, int holder_nr)
3338 {
3339 	if (cb->args[0]) {
3340 		struct drbd_resource *resource =
3341 			(struct drbd_resource *)cb->args[0];
3342 		kref_put(&resource->kref, drbd_destroy_resource);
3343 	}
3344 
3345 	return 0;
3346 }
3347 
3348 int drbd_adm_dump_devices_done(struct netlink_callback *cb) {
3349 	return put_resource_in_arg0(cb, 7);
3350 }
3351 
3352 static void device_to_info(struct device_info *, struct drbd_device *);
3353 
3354 int drbd_adm_dump_devices(struct sk_buff *skb, struct netlink_callback *cb)
3355 {
3356 	struct nlattr *resource_filter;
3357 	struct drbd_resource *resource;
3358 	struct drbd_device *device;
3359 	int minor, err, retcode;
3360 	struct drbd_genlmsghdr *dh;
3361 	struct device_info device_info;
3362 	struct device_statistics device_statistics;
3363 	struct idr *idr_to_search;
3364 
3365 	resource = (struct drbd_resource *)cb->args[0];
3366 	if (!cb->args[0] && !cb->args[1]) {
3367 		resource_filter = find_cfg_context_attr(cb->nlh, T_ctx_resource_name);
3368 		if (resource_filter) {
3369 			retcode = ERR_RES_NOT_KNOWN;
3370 			resource = drbd_find_resource(nla_data(resource_filter));
3371 			if (!resource)
3372 				goto put_result;
3373 			cb->args[0] = (long)resource;
3374 		}
3375 	}
3376 
3377 	rcu_read_lock();
3378 	minor = cb->args[1];
3379 	idr_to_search = resource ? &resource->devices : &drbd_devices;
3380 	device = idr_get_next(idr_to_search, &minor);
3381 	if (!device) {
3382 		err = 0;
3383 		goto out;
3384 	}
3385 	idr_for_each_entry_continue(idr_to_search, device, minor) {
3386 		retcode = NO_ERROR;
3387 		goto put_result;  /* only one iteration */
3388 	}
3389 	err = 0;
3390 	goto out;  /* no more devices */
3391 
3392 put_result:
3393 	dh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
3394 			cb->nlh->nlmsg_seq, &drbd_genl_family,
3395 			NLM_F_MULTI, DRBD_ADM_GET_DEVICES);
3396 	err = -ENOMEM;
3397 	if (!dh)
3398 		goto out;
3399 	dh->ret_code = retcode;
3400 	dh->minor = -1U;
3401 	if (retcode == NO_ERROR) {
3402 		dh->minor = device->minor;
3403 		err = nla_put_drbd_cfg_context(skb, device->resource, NULL, device);
3404 		if (err)
3405 			goto out;
3406 		if (get_ldev(device)) {
3407 			struct disk_conf *disk_conf =
3408 				rcu_dereference(device->ldev->disk_conf);
3409 
3410 			err = disk_conf_to_skb(skb, disk_conf, !capable(CAP_SYS_ADMIN));
3411 			put_ldev(device);
3412 			if (err)
3413 				goto out;
3414 		}
3415 		device_to_info(&device_info, device);
3416 		err = device_info_to_skb(skb, &device_info, !capable(CAP_SYS_ADMIN));
3417 		if (err)
3418 			goto out;
3419 
3420 		device_to_statistics(&device_statistics, device);
3421 		err = device_statistics_to_skb(skb, &device_statistics, !capable(CAP_SYS_ADMIN));
3422 		if (err)
3423 			goto out;
3424 		cb->args[1] = minor + 1;
3425 	}
3426 	genlmsg_end(skb, dh);
3427 	err = 0;
3428 
3429 out:
3430 	rcu_read_unlock();
3431 	if (err)
3432 		return err;
3433 	return skb->len;
3434 }
3435 
3436 int drbd_adm_dump_connections_done(struct netlink_callback *cb)
3437 {
3438 	return put_resource_in_arg0(cb, 6);
3439 }
3440 
3441 enum { SINGLE_RESOURCE, ITERATE_RESOURCES };
3442 
3443 int drbd_adm_dump_connections(struct sk_buff *skb, struct netlink_callback *cb)
3444 {
3445 	struct nlattr *resource_filter;
3446 	struct drbd_resource *resource = NULL, *next_resource;
3447 	struct drbd_connection *connection;
3448 	int err = 0, retcode;
3449 	struct drbd_genlmsghdr *dh;
3450 	struct connection_info connection_info;
3451 	struct connection_statistics connection_statistics;
3452 
3453 	rcu_read_lock();
3454 	resource = (struct drbd_resource *)cb->args[0];
3455 	if (!cb->args[0]) {
3456 		resource_filter = find_cfg_context_attr(cb->nlh, T_ctx_resource_name);
3457 		if (resource_filter) {
3458 			retcode = ERR_RES_NOT_KNOWN;
3459 			resource = drbd_find_resource(nla_data(resource_filter));
3460 			if (!resource)
3461 				goto put_result;
3462 			cb->args[0] = (long)resource;
3463 			cb->args[1] = SINGLE_RESOURCE;
3464 		}
3465 	}
3466 	if (!resource) {
3467 		if (list_empty(&drbd_resources))
3468 			goto out;
3469 		resource = list_first_entry(&drbd_resources, struct drbd_resource, resources);
3470 		kref_get(&resource->kref);
3471 		cb->args[0] = (long)resource;
3472 		cb->args[1] = ITERATE_RESOURCES;
3473 	}
3474 
3475     next_resource:
3476 	rcu_read_unlock();
3477 	mutex_lock(&resource->conf_update);
3478 	rcu_read_lock();
3479 	if (cb->args[2]) {
3480 		for_each_connection_rcu(connection, resource)
3481 			if (connection == (struct drbd_connection *)cb->args[2])
3482 				goto found_connection;
3483 		/* connection was probably deleted */
3484 		goto no_more_connections;
3485 	}
3486 	connection = list_entry(&resource->connections, struct drbd_connection, connections);
3487 
3488 found_connection:
3489 	list_for_each_entry_continue_rcu(connection, &resource->connections, connections) {
3490 		if (!has_net_conf(connection))
3491 			continue;
3492 		retcode = NO_ERROR;
3493 		goto put_result;  /* only one iteration */
3494 	}
3495 
3496 no_more_connections:
3497 	if (cb->args[1] == ITERATE_RESOURCES) {
3498 		for_each_resource_rcu(next_resource, &drbd_resources) {
3499 			if (next_resource == resource)
3500 				goto found_resource;
3501 		}
3502 		/* resource was probably deleted */
3503 	}
3504 	goto out;
3505 
3506 found_resource:
3507 	list_for_each_entry_continue_rcu(next_resource, &drbd_resources, resources) {
3508 		mutex_unlock(&resource->conf_update);
3509 		kref_put(&resource->kref, drbd_destroy_resource);
3510 		resource = next_resource;
3511 		kref_get(&resource->kref);
3512 		cb->args[0] = (long)resource;
3513 		cb->args[2] = 0;
3514 		goto next_resource;
3515 	}
3516 	goto out;  /* no more resources */
3517 
3518 put_result:
3519 	dh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
3520 			cb->nlh->nlmsg_seq, &drbd_genl_family,
3521 			NLM_F_MULTI, DRBD_ADM_GET_CONNECTIONS);
3522 	err = -ENOMEM;
3523 	if (!dh)
3524 		goto out;
3525 	dh->ret_code = retcode;
3526 	dh->minor = -1U;
3527 	if (retcode == NO_ERROR) {
3528 		struct net_conf *net_conf;
3529 
3530 		err = nla_put_drbd_cfg_context(skb, resource, connection, NULL);
3531 		if (err)
3532 			goto out;
3533 		net_conf = rcu_dereference(connection->net_conf);
3534 		if (net_conf) {
3535 			err = net_conf_to_skb(skb, net_conf, !capable(CAP_SYS_ADMIN));
3536 			if (err)
3537 				goto out;
3538 		}
3539 		connection_to_info(&connection_info, connection);
3540 		err = connection_info_to_skb(skb, &connection_info, !capable(CAP_SYS_ADMIN));
3541 		if (err)
3542 			goto out;
3543 		connection_statistics.conn_congested = test_bit(NET_CONGESTED, &connection->flags);
3544 		err = connection_statistics_to_skb(skb, &connection_statistics, !capable(CAP_SYS_ADMIN));
3545 		if (err)
3546 			goto out;
3547 		cb->args[2] = (long)connection;
3548 	}
3549 	genlmsg_end(skb, dh);
3550 	err = 0;
3551 
3552 out:
3553 	rcu_read_unlock();
3554 	if (resource)
3555 		mutex_unlock(&resource->conf_update);
3556 	if (err)
3557 		return err;
3558 	return skb->len;
3559 }
3560 
3561 enum mdf_peer_flag {
3562 	MDF_PEER_CONNECTED =	1 << 0,
3563 	MDF_PEER_OUTDATED =	1 << 1,
3564 	MDF_PEER_FENCING =	1 << 2,
3565 	MDF_PEER_FULL_SYNC =	1 << 3,
3566 };
3567 
3568 static void peer_device_to_statistics(struct peer_device_statistics *s,
3569 				      struct drbd_peer_device *peer_device)
3570 {
3571 	struct drbd_device *device = peer_device->device;
3572 
3573 	memset(s, 0, sizeof(*s));
3574 	s->peer_dev_received = device->recv_cnt;
3575 	s->peer_dev_sent = device->send_cnt;
3576 	s->peer_dev_pending = atomic_read(&device->ap_pending_cnt) +
3577 			      atomic_read(&device->rs_pending_cnt);
3578 	s->peer_dev_unacked = atomic_read(&device->unacked_cnt);
3579 	s->peer_dev_out_of_sync = drbd_bm_total_weight(device) << (BM_BLOCK_SHIFT - 9);
3580 	s->peer_dev_resync_failed = device->rs_failed << (BM_BLOCK_SHIFT - 9);
3581 	if (get_ldev(device)) {
3582 		struct drbd_md *md = &device->ldev->md;
3583 
3584 		spin_lock_irq(&md->uuid_lock);
3585 		s->peer_dev_bitmap_uuid = md->uuid[UI_BITMAP];
3586 		spin_unlock_irq(&md->uuid_lock);
3587 		s->peer_dev_flags =
3588 			(drbd_md_test_flag(device->ldev, MDF_CONNECTED_IND) ?
3589 				MDF_PEER_CONNECTED : 0) +
3590 			(drbd_md_test_flag(device->ldev, MDF_CONSISTENT) &&
3591 			 !drbd_md_test_flag(device->ldev, MDF_WAS_UP_TO_DATE) ?
3592 				MDF_PEER_OUTDATED : 0) +
3593 			/* FIXME: MDF_PEER_FENCING? */
3594 			(drbd_md_test_flag(device->ldev, MDF_FULL_SYNC) ?
3595 				MDF_PEER_FULL_SYNC : 0);
3596 		put_ldev(device);
3597 	}
3598 }
3599 
3600 int drbd_adm_dump_peer_devices_done(struct netlink_callback *cb)
3601 {
3602 	return put_resource_in_arg0(cb, 9);
3603 }
3604 
3605 int drbd_adm_dump_peer_devices(struct sk_buff *skb, struct netlink_callback *cb)
3606 {
3607 	struct nlattr *resource_filter;
3608 	struct drbd_resource *resource;
3609 	struct drbd_device *device;
3610 	struct drbd_peer_device *peer_device = NULL;
3611 	int minor, err, retcode;
3612 	struct drbd_genlmsghdr *dh;
3613 	struct idr *idr_to_search;
3614 
3615 	resource = (struct drbd_resource *)cb->args[0];
3616 	if (!cb->args[0] && !cb->args[1]) {
3617 		resource_filter = find_cfg_context_attr(cb->nlh, T_ctx_resource_name);
3618 		if (resource_filter) {
3619 			retcode = ERR_RES_NOT_KNOWN;
3620 			resource = drbd_find_resource(nla_data(resource_filter));
3621 			if (!resource)
3622 				goto put_result;
3623 		}
3624 		cb->args[0] = (long)resource;
3625 	}
3626 
3627 	rcu_read_lock();
3628 	minor = cb->args[1];
3629 	idr_to_search = resource ? &resource->devices : &drbd_devices;
3630 	device = idr_find(idr_to_search, minor);
3631 	if (!device) {
3632 next_device:
3633 		minor++;
3634 		cb->args[2] = 0;
3635 		device = idr_get_next(idr_to_search, &minor);
3636 		if (!device) {
3637 			err = 0;
3638 			goto out;
3639 		}
3640 	}
3641 	if (cb->args[2]) {
3642 		for_each_peer_device(peer_device, device)
3643 			if (peer_device == (struct drbd_peer_device *)cb->args[2])
3644 				goto found_peer_device;
3645 		/* peer device was probably deleted */
3646 		goto next_device;
3647 	}
3648 	/* Make peer_device point to the list head (not the first entry). */
3649 	peer_device = list_entry(&device->peer_devices, struct drbd_peer_device, peer_devices);
3650 
3651 found_peer_device:
3652 	list_for_each_entry_continue_rcu(peer_device, &device->peer_devices, peer_devices) {
3653 		if (!has_net_conf(peer_device->connection))
3654 			continue;
3655 		retcode = NO_ERROR;
3656 		goto put_result;  /* only one iteration */
3657 	}
3658 	goto next_device;
3659 
3660 put_result:
3661 	dh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
3662 			cb->nlh->nlmsg_seq, &drbd_genl_family,
3663 			NLM_F_MULTI, DRBD_ADM_GET_PEER_DEVICES);
3664 	err = -ENOMEM;
3665 	if (!dh)
3666 		goto out;
3667 	dh->ret_code = retcode;
3668 	dh->minor = -1U;
3669 	if (retcode == NO_ERROR) {
3670 		struct peer_device_info peer_device_info;
3671 		struct peer_device_statistics peer_device_statistics;
3672 
3673 		dh->minor = minor;
3674 		err = nla_put_drbd_cfg_context(skb, device->resource, peer_device->connection, device);
3675 		if (err)
3676 			goto out;
3677 		peer_device_to_info(&peer_device_info, peer_device);
3678 		err = peer_device_info_to_skb(skb, &peer_device_info, !capable(CAP_SYS_ADMIN));
3679 		if (err)
3680 			goto out;
3681 		peer_device_to_statistics(&peer_device_statistics, peer_device);
3682 		err = peer_device_statistics_to_skb(skb, &peer_device_statistics, !capable(CAP_SYS_ADMIN));
3683 		if (err)
3684 			goto out;
3685 		cb->args[1] = minor;
3686 		cb->args[2] = (long)peer_device;
3687 	}
3688 	genlmsg_end(skb, dh);
3689 	err = 0;
3690 
3691 out:
3692 	rcu_read_unlock();
3693 	if (err)
3694 		return err;
3695 	return skb->len;
3696 }
3697 /*
3698  * Return the connection of @resource if @resource has exactly one connection.
3699  */
3700 static struct drbd_connection *the_only_connection(struct drbd_resource *resource)
3701 {
3702 	struct list_head *connections = &resource->connections;
3703 
3704 	if (list_empty(connections) || connections->next->next != connections)
3705 		return NULL;
3706 	return list_first_entry(&resource->connections, struct drbd_connection, connections);
3707 }
3708 
3709 static int nla_put_status_info(struct sk_buff *skb, struct drbd_device *device,
3710 		const struct sib_info *sib)
3711 {
3712 	struct drbd_resource *resource = device->resource;
3713 	struct state_info *si = NULL; /* for sizeof(si->member); */
3714 	struct nlattr *nla;
3715 	int got_ldev;
3716 	int err = 0;
3717 	int exclude_sensitive;
3718 
3719 	/* If sib != NULL, this is drbd_bcast_event, which anyone can listen
3720 	 * to.  So we better exclude_sensitive information.
3721 	 *
3722 	 * If sib == NULL, this is drbd_adm_get_status, executed synchronously
3723 	 * in the context of the requesting user process. Exclude sensitive
3724 	 * information, unless current has superuser.
3725 	 *
3726 	 * NOTE: for drbd_adm_get_status_all(), this is a netlink dump, and
3727 	 * relies on the current implementation of netlink_dump(), which
3728 	 * executes the dump callback successively from netlink_recvmsg(),
3729 	 * always in the context of the receiving process */
3730 	exclude_sensitive = sib || !capable(CAP_SYS_ADMIN);
3731 
3732 	got_ldev = get_ldev(device);
3733 
3734 	/* We need to add connection name and volume number information still.
3735 	 * Minor number is in drbd_genlmsghdr. */
3736 	if (nla_put_drbd_cfg_context(skb, resource, the_only_connection(resource), device))
3737 		goto nla_put_failure;
3738 
3739 	if (res_opts_to_skb(skb, &device->resource->res_opts, exclude_sensitive))
3740 		goto nla_put_failure;
3741 
3742 	rcu_read_lock();
3743 	if (got_ldev) {
3744 		struct disk_conf *disk_conf;
3745 
3746 		disk_conf = rcu_dereference(device->ldev->disk_conf);
3747 		err = disk_conf_to_skb(skb, disk_conf, exclude_sensitive);
3748 	}
3749 	if (!err) {
3750 		struct net_conf *nc;
3751 
3752 		nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
3753 		if (nc)
3754 			err = net_conf_to_skb(skb, nc, exclude_sensitive);
3755 	}
3756 	rcu_read_unlock();
3757 	if (err)
3758 		goto nla_put_failure;
3759 
3760 	nla = nla_nest_start_noflag(skb, DRBD_NLA_STATE_INFO);
3761 	if (!nla)
3762 		goto nla_put_failure;
3763 	if (nla_put_u32(skb, T_sib_reason, sib ? sib->sib_reason : SIB_GET_STATUS_REPLY) ||
3764 	    nla_put_u32(skb, T_current_state, device->state.i) ||
3765 	    nla_put_u64_0pad(skb, T_ed_uuid, device->ed_uuid) ||
3766 	    nla_put_u64_0pad(skb, T_capacity, get_capacity(device->vdisk)) ||
3767 	    nla_put_u64_0pad(skb, T_send_cnt, device->send_cnt) ||
3768 	    nla_put_u64_0pad(skb, T_recv_cnt, device->recv_cnt) ||
3769 	    nla_put_u64_0pad(skb, T_read_cnt, device->read_cnt) ||
3770 	    nla_put_u64_0pad(skb, T_writ_cnt, device->writ_cnt) ||
3771 	    nla_put_u64_0pad(skb, T_al_writ_cnt, device->al_writ_cnt) ||
3772 	    nla_put_u64_0pad(skb, T_bm_writ_cnt, device->bm_writ_cnt) ||
3773 	    nla_put_u32(skb, T_ap_bio_cnt, atomic_read(&device->ap_bio_cnt)) ||
3774 	    nla_put_u32(skb, T_ap_pending_cnt, atomic_read(&device->ap_pending_cnt)) ||
3775 	    nla_put_u32(skb, T_rs_pending_cnt, atomic_read(&device->rs_pending_cnt)))
3776 		goto nla_put_failure;
3777 
3778 	if (got_ldev) {
3779 		int err;
3780 
3781 		spin_lock_irq(&device->ldev->md.uuid_lock);
3782 		err = nla_put(skb, T_uuids, sizeof(si->uuids), device->ldev->md.uuid);
3783 		spin_unlock_irq(&device->ldev->md.uuid_lock);
3784 
3785 		if (err)
3786 			goto nla_put_failure;
3787 
3788 		if (nla_put_u32(skb, T_disk_flags, device->ldev->md.flags) ||
3789 		    nla_put_u64_0pad(skb, T_bits_total, drbd_bm_bits(device)) ||
3790 		    nla_put_u64_0pad(skb, T_bits_oos,
3791 				     drbd_bm_total_weight(device)))
3792 			goto nla_put_failure;
3793 		if (C_SYNC_SOURCE <= device->state.conn &&
3794 		    C_PAUSED_SYNC_T >= device->state.conn) {
3795 			if (nla_put_u64_0pad(skb, T_bits_rs_total,
3796 					     device->rs_total) ||
3797 			    nla_put_u64_0pad(skb, T_bits_rs_failed,
3798 					     device->rs_failed))
3799 				goto nla_put_failure;
3800 		}
3801 	}
3802 
3803 	if (sib) {
3804 		switch(sib->sib_reason) {
3805 		case SIB_SYNC_PROGRESS:
3806 		case SIB_GET_STATUS_REPLY:
3807 			break;
3808 		case SIB_STATE_CHANGE:
3809 			if (nla_put_u32(skb, T_prev_state, sib->os.i) ||
3810 			    nla_put_u32(skb, T_new_state, sib->ns.i))
3811 				goto nla_put_failure;
3812 			break;
3813 		case SIB_HELPER_POST:
3814 			if (nla_put_u32(skb, T_helper_exit_code,
3815 					sib->helper_exit_code))
3816 				goto nla_put_failure;
3817 			fallthrough;
3818 		case SIB_HELPER_PRE:
3819 			if (nla_put_string(skb, T_helper, sib->helper_name))
3820 				goto nla_put_failure;
3821 			break;
3822 		}
3823 	}
3824 	nla_nest_end(skb, nla);
3825 
3826 	if (0)
3827 nla_put_failure:
3828 		err = -EMSGSIZE;
3829 	if (got_ldev)
3830 		put_ldev(device);
3831 	return err;
3832 }
3833 
3834 int drbd_adm_get_status(struct sk_buff *skb, struct genl_info *info)
3835 {
3836 	struct drbd_config_context adm_ctx;
3837 	enum drbd_ret_code retcode;
3838 	int err;
3839 
3840 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
3841 	if (!adm_ctx.reply_skb)
3842 		return retcode;
3843 	if (retcode != NO_ERROR)
3844 		goto out;
3845 
3846 	err = nla_put_status_info(adm_ctx.reply_skb, adm_ctx.device, NULL);
3847 	if (err) {
3848 		nlmsg_free(adm_ctx.reply_skb);
3849 		return err;
3850 	}
3851 out:
3852 	drbd_adm_finish(&adm_ctx, info, retcode);
3853 	return 0;
3854 }
3855 
3856 static int get_one_status(struct sk_buff *skb, struct netlink_callback *cb)
3857 {
3858 	struct drbd_device *device;
3859 	struct drbd_genlmsghdr *dh;
3860 	struct drbd_resource *pos = (struct drbd_resource *)cb->args[0];
3861 	struct drbd_resource *resource = NULL;
3862 	struct drbd_resource *tmp;
3863 	unsigned volume = cb->args[1];
3864 
3865 	/* Open coded, deferred, iteration:
3866 	 * for_each_resource_safe(resource, tmp, &drbd_resources) {
3867 	 *      connection = "first connection of resource or undefined";
3868 	 *	idr_for_each_entry(&resource->devices, device, i) {
3869 	 *	  ...
3870 	 *	}
3871 	 * }
3872 	 * where resource is cb->args[0];
3873 	 * and i is cb->args[1];
3874 	 *
3875 	 * cb->args[2] indicates if we shall loop over all resources,
3876 	 * or just dump all volumes of a single resource.
3877 	 *
3878 	 * This may miss entries inserted after this dump started,
3879 	 * or entries deleted before they are reached.
3880 	 *
3881 	 * We need to make sure the device won't disappear while
3882 	 * we are looking at it, and revalidate our iterators
3883 	 * on each iteration.
3884 	 */
3885 
3886 	/* synchronize with conn_create()/drbd_destroy_connection() */
3887 	rcu_read_lock();
3888 	/* revalidate iterator position */
3889 	for_each_resource_rcu(tmp, &drbd_resources) {
3890 		if (pos == NULL) {
3891 			/* first iteration */
3892 			pos = tmp;
3893 			resource = pos;
3894 			break;
3895 		}
3896 		if (tmp == pos) {
3897 			resource = pos;
3898 			break;
3899 		}
3900 	}
3901 	if (resource) {
3902 next_resource:
3903 		device = idr_get_next(&resource->devices, &volume);
3904 		if (!device) {
3905 			/* No more volumes to dump on this resource.
3906 			 * Advance resource iterator. */
3907 			pos = list_entry_rcu(resource->resources.next,
3908 					     struct drbd_resource, resources);
3909 			/* Did we dump any volume of this resource yet? */
3910 			if (volume != 0) {
3911 				/* If we reached the end of the list,
3912 				 * or only a single resource dump was requested,
3913 				 * we are done. */
3914 				if (&pos->resources == &drbd_resources || cb->args[2])
3915 					goto out;
3916 				volume = 0;
3917 				resource = pos;
3918 				goto next_resource;
3919 			}
3920 		}
3921 
3922 		dh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
3923 				cb->nlh->nlmsg_seq, &drbd_genl_family,
3924 				NLM_F_MULTI, DRBD_ADM_GET_STATUS);
3925 		if (!dh)
3926 			goto out;
3927 
3928 		if (!device) {
3929 			/* This is a connection without a single volume.
3930 			 * Suprisingly enough, it may have a network
3931 			 * configuration. */
3932 			struct drbd_connection *connection;
3933 
3934 			dh->minor = -1U;
3935 			dh->ret_code = NO_ERROR;
3936 			connection = the_only_connection(resource);
3937 			if (nla_put_drbd_cfg_context(skb, resource, connection, NULL))
3938 				goto cancel;
3939 			if (connection) {
3940 				struct net_conf *nc;
3941 
3942 				nc = rcu_dereference(connection->net_conf);
3943 				if (nc && net_conf_to_skb(skb, nc, 1) != 0)
3944 					goto cancel;
3945 			}
3946 			goto done;
3947 		}
3948 
3949 		D_ASSERT(device, device->vnr == volume);
3950 		D_ASSERT(device, device->resource == resource);
3951 
3952 		dh->minor = device_to_minor(device);
3953 		dh->ret_code = NO_ERROR;
3954 
3955 		if (nla_put_status_info(skb, device, NULL)) {
3956 cancel:
3957 			genlmsg_cancel(skb, dh);
3958 			goto out;
3959 		}
3960 done:
3961 		genlmsg_end(skb, dh);
3962 	}
3963 
3964 out:
3965 	rcu_read_unlock();
3966 	/* where to start the next iteration */
3967 	cb->args[0] = (long)pos;
3968 	cb->args[1] = (pos == resource) ? volume + 1 : 0;
3969 
3970 	/* No more resources/volumes/minors found results in an empty skb.
3971 	 * Which will terminate the dump. */
3972         return skb->len;
3973 }
3974 
3975 /*
3976  * Request status of all resources, or of all volumes within a single resource.
3977  *
3978  * This is a dump, as the answer may not fit in a single reply skb otherwise.
3979  * Which means we cannot use the family->attrbuf or other such members, because
3980  * dump is NOT protected by the genl_lock().  During dump, we only have access
3981  * to the incoming skb, and need to opencode "parsing" of the nlattr payload.
3982  *
3983  * Once things are setup properly, we call into get_one_status().
3984  */
3985 int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
3986 {
3987 	const unsigned hdrlen = GENL_HDRLEN + GENL_MAGIC_FAMILY_HDRSZ;
3988 	struct nlattr *nla;
3989 	const char *resource_name;
3990 	struct drbd_resource *resource;
3991 	int maxtype;
3992 
3993 	/* Is this a followup call? */
3994 	if (cb->args[0]) {
3995 		/* ... of a single resource dump,
3996 		 * and the resource iterator has been advanced already? */
3997 		if (cb->args[2] && cb->args[2] != cb->args[0])
3998 			return 0; /* DONE. */
3999 		goto dump;
4000 	}
4001 
4002 	/* First call (from netlink_dump_start).  We need to figure out
4003 	 * which resource(s) the user wants us to dump. */
4004 	nla = nla_find(nlmsg_attrdata(cb->nlh, hdrlen),
4005 			nlmsg_attrlen(cb->nlh, hdrlen),
4006 			DRBD_NLA_CFG_CONTEXT);
4007 
4008 	/* No explicit context given.  Dump all. */
4009 	if (!nla)
4010 		goto dump;
4011 	maxtype = ARRAY_SIZE(drbd_cfg_context_nl_policy) - 1;
4012 	nla = drbd_nla_find_nested(maxtype, nla, __nla_type(T_ctx_resource_name));
4013 	if (IS_ERR(nla))
4014 		return PTR_ERR(nla);
4015 	/* context given, but no name present? */
4016 	if (!nla)
4017 		return -EINVAL;
4018 	resource_name = nla_data(nla);
4019 	if (!*resource_name)
4020 		return -ENODEV;
4021 	resource = drbd_find_resource(resource_name);
4022 	if (!resource)
4023 		return -ENODEV;
4024 
4025 	kref_put(&resource->kref, drbd_destroy_resource); /* get_one_status() revalidates the resource */
4026 
4027 	/* prime iterators, and set "filter" mode mark:
4028 	 * only dump this connection. */
4029 	cb->args[0] = (long)resource;
4030 	/* cb->args[1] = 0; passed in this way. */
4031 	cb->args[2] = (long)resource;
4032 
4033 dump:
4034 	return get_one_status(skb, cb);
4035 }
4036 
4037 int drbd_adm_get_timeout_type(struct sk_buff *skb, struct genl_info *info)
4038 {
4039 	struct drbd_config_context adm_ctx;
4040 	enum drbd_ret_code retcode;
4041 	struct timeout_parms tp;
4042 	int err;
4043 
4044 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
4045 	if (!adm_ctx.reply_skb)
4046 		return retcode;
4047 	if (retcode != NO_ERROR)
4048 		goto out;
4049 
4050 	tp.timeout_type =
4051 		adm_ctx.device->state.pdsk == D_OUTDATED ? UT_PEER_OUTDATED :
4052 		test_bit(USE_DEGR_WFC_T, &adm_ctx.device->flags) ? UT_DEGRADED :
4053 		UT_DEFAULT;
4054 
4055 	err = timeout_parms_to_priv_skb(adm_ctx.reply_skb, &tp);
4056 	if (err) {
4057 		nlmsg_free(adm_ctx.reply_skb);
4058 		return err;
4059 	}
4060 out:
4061 	drbd_adm_finish(&adm_ctx, info, retcode);
4062 	return 0;
4063 }
4064 
4065 int drbd_adm_start_ov(struct sk_buff *skb, struct genl_info *info)
4066 {
4067 	struct drbd_config_context adm_ctx;
4068 	struct drbd_device *device;
4069 	enum drbd_ret_code retcode;
4070 	struct start_ov_parms parms;
4071 
4072 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
4073 	if (!adm_ctx.reply_skb)
4074 		return retcode;
4075 	if (retcode != NO_ERROR)
4076 		goto out;
4077 
4078 	device = adm_ctx.device;
4079 
4080 	/* resume from last known position, if possible */
4081 	parms.ov_start_sector = device->ov_start_sector;
4082 	parms.ov_stop_sector = ULLONG_MAX;
4083 	if (info->attrs[DRBD_NLA_START_OV_PARMS]) {
4084 		int err = start_ov_parms_from_attrs(&parms, info);
4085 		if (err) {
4086 			retcode = ERR_MANDATORY_TAG;
4087 			drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
4088 			goto out;
4089 		}
4090 	}
4091 	mutex_lock(&adm_ctx.resource->adm_mutex);
4092 
4093 	/* w_make_ov_request expects position to be aligned */
4094 	device->ov_start_sector = parms.ov_start_sector & ~(BM_SECT_PER_BIT-1);
4095 	device->ov_stop_sector = parms.ov_stop_sector;
4096 
4097 	/* If there is still bitmap IO pending, e.g. previous resync or verify
4098 	 * just being finished, wait for it before requesting a new resync. */
4099 	drbd_suspend_io(device);
4100 	wait_event(device->misc_wait, !test_bit(BITMAP_IO, &device->flags));
4101 	retcode = drbd_request_state(device, NS(conn, C_VERIFY_S));
4102 	drbd_resume_io(device);
4103 
4104 	mutex_unlock(&adm_ctx.resource->adm_mutex);
4105 out:
4106 	drbd_adm_finish(&adm_ctx, info, retcode);
4107 	return 0;
4108 }
4109 
4110 
4111 int drbd_adm_new_c_uuid(struct sk_buff *skb, struct genl_info *info)
4112 {
4113 	struct drbd_config_context adm_ctx;
4114 	struct drbd_device *device;
4115 	enum drbd_ret_code retcode;
4116 	int skip_initial_sync = 0;
4117 	int err;
4118 	struct new_c_uuid_parms args;
4119 
4120 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
4121 	if (!adm_ctx.reply_skb)
4122 		return retcode;
4123 	if (retcode != NO_ERROR)
4124 		goto out_nolock;
4125 
4126 	device = adm_ctx.device;
4127 	memset(&args, 0, sizeof(args));
4128 	if (info->attrs[DRBD_NLA_NEW_C_UUID_PARMS]) {
4129 		err = new_c_uuid_parms_from_attrs(&args, info);
4130 		if (err) {
4131 			retcode = ERR_MANDATORY_TAG;
4132 			drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
4133 			goto out_nolock;
4134 		}
4135 	}
4136 
4137 	mutex_lock(&adm_ctx.resource->adm_mutex);
4138 	mutex_lock(device->state_mutex); /* Protects us against serialized state changes. */
4139 
4140 	if (!get_ldev(device)) {
4141 		retcode = ERR_NO_DISK;
4142 		goto out;
4143 	}
4144 
4145 	/* this is "skip initial sync", assume to be clean */
4146 	if (device->state.conn == C_CONNECTED &&
4147 	    first_peer_device(device)->connection->agreed_pro_version >= 90 &&
4148 	    device->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED && args.clear_bm) {
4149 		drbd_info(device, "Preparing to skip initial sync\n");
4150 		skip_initial_sync = 1;
4151 	} else if (device->state.conn != C_STANDALONE) {
4152 		retcode = ERR_CONNECTED;
4153 		goto out_dec;
4154 	}
4155 
4156 	drbd_uuid_set(device, UI_BITMAP, 0); /* Rotate UI_BITMAP to History 1, etc... */
4157 	drbd_uuid_new_current(device); /* New current, previous to UI_BITMAP */
4158 
4159 	if (args.clear_bm) {
4160 		err = drbd_bitmap_io(device, &drbd_bmio_clear_n_write,
4161 			"clear_n_write from new_c_uuid", BM_LOCKED_MASK, NULL);
4162 		if (err) {
4163 			drbd_err(device, "Writing bitmap failed with %d\n", err);
4164 			retcode = ERR_IO_MD_DISK;
4165 		}
4166 		if (skip_initial_sync) {
4167 			drbd_send_uuids_skip_initial_sync(first_peer_device(device));
4168 			_drbd_uuid_set(device, UI_BITMAP, 0);
4169 			drbd_print_uuids(device, "cleared bitmap UUID");
4170 			spin_lock_irq(&device->resource->req_lock);
4171 			_drbd_set_state(_NS2(device, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
4172 					CS_VERBOSE, NULL);
4173 			spin_unlock_irq(&device->resource->req_lock);
4174 		}
4175 	}
4176 
4177 	drbd_md_sync(device);
4178 out_dec:
4179 	put_ldev(device);
4180 out:
4181 	mutex_unlock(device->state_mutex);
4182 	mutex_unlock(&adm_ctx.resource->adm_mutex);
4183 out_nolock:
4184 	drbd_adm_finish(&adm_ctx, info, retcode);
4185 	return 0;
4186 }
4187 
4188 static enum drbd_ret_code
4189 drbd_check_resource_name(struct drbd_config_context *adm_ctx)
4190 {
4191 	const char *name = adm_ctx->resource_name;
4192 	if (!name || !name[0]) {
4193 		drbd_msg_put_info(adm_ctx->reply_skb, "resource name missing");
4194 		return ERR_MANDATORY_TAG;
4195 	}
4196 	/* if we want to use these in sysfs/configfs/debugfs some day,
4197 	 * we must not allow slashes */
4198 	if (strchr(name, '/')) {
4199 		drbd_msg_put_info(adm_ctx->reply_skb, "invalid resource name");
4200 		return ERR_INVALID_REQUEST;
4201 	}
4202 	return NO_ERROR;
4203 }
4204 
4205 static void resource_to_info(struct resource_info *info,
4206 			     struct drbd_resource *resource)
4207 {
4208 	info->res_role = conn_highest_role(first_connection(resource));
4209 	info->res_susp = resource->susp;
4210 	info->res_susp_nod = resource->susp_nod;
4211 	info->res_susp_fen = resource->susp_fen;
4212 }
4213 
4214 int drbd_adm_new_resource(struct sk_buff *skb, struct genl_info *info)
4215 {
4216 	struct drbd_connection *connection;
4217 	struct drbd_config_context adm_ctx;
4218 	enum drbd_ret_code retcode;
4219 	struct res_opts res_opts;
4220 	int err;
4221 
4222 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, 0);
4223 	if (!adm_ctx.reply_skb)
4224 		return retcode;
4225 	if (retcode != NO_ERROR)
4226 		goto out;
4227 
4228 	set_res_opts_defaults(&res_opts);
4229 	err = res_opts_from_attrs(&res_opts, info);
4230 	if (err && err != -ENOMSG) {
4231 		retcode = ERR_MANDATORY_TAG;
4232 		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
4233 		goto out;
4234 	}
4235 
4236 	retcode = drbd_check_resource_name(&adm_ctx);
4237 	if (retcode != NO_ERROR)
4238 		goto out;
4239 
4240 	if (adm_ctx.resource) {
4241 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) {
4242 			retcode = ERR_INVALID_REQUEST;
4243 			drbd_msg_put_info(adm_ctx.reply_skb, "resource exists");
4244 		}
4245 		/* else: still NO_ERROR */
4246 		goto out;
4247 	}
4248 
4249 	/* not yet safe for genl_family.parallel_ops */
4250 	mutex_lock(&resources_mutex);
4251 	connection = conn_create(adm_ctx.resource_name, &res_opts);
4252 	mutex_unlock(&resources_mutex);
4253 
4254 	if (connection) {
4255 		struct resource_info resource_info;
4256 
4257 		mutex_lock(&notification_mutex);
4258 		resource_to_info(&resource_info, connection->resource);
4259 		notify_resource_state(NULL, 0, connection->resource,
4260 				      &resource_info, NOTIFY_CREATE);
4261 		mutex_unlock(&notification_mutex);
4262 	} else
4263 		retcode = ERR_NOMEM;
4264 
4265 out:
4266 	drbd_adm_finish(&adm_ctx, info, retcode);
4267 	return 0;
4268 }
4269 
4270 static void device_to_info(struct device_info *info,
4271 			   struct drbd_device *device)
4272 {
4273 	info->dev_disk_state = device->state.disk;
4274 }
4275 
4276 
4277 int drbd_adm_new_minor(struct sk_buff *skb, struct genl_info *info)
4278 {
4279 	struct drbd_config_context adm_ctx;
4280 	struct drbd_genlmsghdr *dh = genl_info_userhdr(info);
4281 	enum drbd_ret_code retcode;
4282 
4283 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);
4284 	if (!adm_ctx.reply_skb)
4285 		return retcode;
4286 	if (retcode != NO_ERROR)
4287 		goto out;
4288 
4289 	if (dh->minor > MINORMASK) {
4290 		drbd_msg_put_info(adm_ctx.reply_skb, "requested minor out of range");
4291 		retcode = ERR_INVALID_REQUEST;
4292 		goto out;
4293 	}
4294 	if (adm_ctx.volume > DRBD_VOLUME_MAX) {
4295 		drbd_msg_put_info(adm_ctx.reply_skb, "requested volume id out of range");
4296 		retcode = ERR_INVALID_REQUEST;
4297 		goto out;
4298 	}
4299 
4300 	/* drbd_adm_prepare made sure already
4301 	 * that first_peer_device(device)->connection and device->vnr match the request. */
4302 	if (adm_ctx.device) {
4303 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
4304 			retcode = ERR_MINOR_OR_VOLUME_EXISTS;
4305 		/* else: still NO_ERROR */
4306 		goto out;
4307 	}
4308 
4309 	mutex_lock(&adm_ctx.resource->adm_mutex);
4310 	retcode = drbd_create_device(&adm_ctx, dh->minor);
4311 	if (retcode == NO_ERROR) {
4312 		struct drbd_device *device;
4313 		struct drbd_peer_device *peer_device;
4314 		struct device_info info;
4315 		unsigned int peer_devices = 0;
4316 		enum drbd_notification_type flags;
4317 
4318 		device = minor_to_device(dh->minor);
4319 		for_each_peer_device(peer_device, device) {
4320 			if (!has_net_conf(peer_device->connection))
4321 				continue;
4322 			peer_devices++;
4323 		}
4324 
4325 		device_to_info(&info, device);
4326 		mutex_lock(&notification_mutex);
4327 		flags = (peer_devices--) ? NOTIFY_CONTINUES : 0;
4328 		notify_device_state(NULL, 0, device, &info, NOTIFY_CREATE | flags);
4329 		for_each_peer_device(peer_device, device) {
4330 			struct peer_device_info peer_device_info;
4331 
4332 			if (!has_net_conf(peer_device->connection))
4333 				continue;
4334 			peer_device_to_info(&peer_device_info, peer_device);
4335 			flags = (peer_devices--) ? NOTIFY_CONTINUES : 0;
4336 			notify_peer_device_state(NULL, 0, peer_device, &peer_device_info,
4337 						 NOTIFY_CREATE | flags);
4338 		}
4339 		mutex_unlock(&notification_mutex);
4340 	}
4341 	mutex_unlock(&adm_ctx.resource->adm_mutex);
4342 out:
4343 	drbd_adm_finish(&adm_ctx, info, retcode);
4344 	return 0;
4345 }
4346 
4347 static enum drbd_ret_code adm_del_minor(struct drbd_device *device)
4348 {
4349 	struct drbd_peer_device *peer_device;
4350 
4351 	if (device->state.disk == D_DISKLESS &&
4352 	    /* no need to be device->state.conn == C_STANDALONE &&
4353 	     * we may want to delete a minor from a live replication group.
4354 	     */
4355 	    device->state.role == R_SECONDARY) {
4356 		struct drbd_connection *connection =
4357 			first_connection(device->resource);
4358 
4359 		_drbd_request_state(device, NS(conn, C_WF_REPORT_PARAMS),
4360 				    CS_VERBOSE + CS_WAIT_COMPLETE);
4361 
4362 		/* If the state engine hasn't stopped the sender thread yet, we
4363 		 * need to flush the sender work queue before generating the
4364 		 * DESTROY events here. */
4365 		if (get_t_state(&connection->worker) == RUNNING)
4366 			drbd_flush_workqueue(&connection->sender_work);
4367 
4368 		mutex_lock(&notification_mutex);
4369 		for_each_peer_device(peer_device, device) {
4370 			if (!has_net_conf(peer_device->connection))
4371 				continue;
4372 			notify_peer_device_state(NULL, 0, peer_device, NULL,
4373 						 NOTIFY_DESTROY | NOTIFY_CONTINUES);
4374 		}
4375 		notify_device_state(NULL, 0, device, NULL, NOTIFY_DESTROY);
4376 		mutex_unlock(&notification_mutex);
4377 
4378 		drbd_delete_device(device);
4379 		return NO_ERROR;
4380 	} else
4381 		return ERR_MINOR_CONFIGURED;
4382 }
4383 
4384 int drbd_adm_del_minor(struct sk_buff *skb, struct genl_info *info)
4385 {
4386 	struct drbd_config_context adm_ctx;
4387 	enum drbd_ret_code retcode;
4388 
4389 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
4390 	if (!adm_ctx.reply_skb)
4391 		return retcode;
4392 	if (retcode != NO_ERROR)
4393 		goto out;
4394 
4395 	mutex_lock(&adm_ctx.resource->adm_mutex);
4396 	retcode = adm_del_minor(adm_ctx.device);
4397 	mutex_unlock(&adm_ctx.resource->adm_mutex);
4398 out:
4399 	drbd_adm_finish(&adm_ctx, info, retcode);
4400 	return 0;
4401 }
4402 
4403 static int adm_del_resource(struct drbd_resource *resource)
4404 {
4405 	struct drbd_connection *connection;
4406 
4407 	for_each_connection(connection, resource) {
4408 		if (connection->cstate > C_STANDALONE)
4409 			return ERR_NET_CONFIGURED;
4410 	}
4411 	if (!idr_is_empty(&resource->devices))
4412 		return ERR_RES_IN_USE;
4413 
4414 	/* The state engine has stopped the sender thread, so we don't
4415 	 * need to flush the sender work queue before generating the
4416 	 * DESTROY event here. */
4417 	mutex_lock(&notification_mutex);
4418 	notify_resource_state(NULL, 0, resource, NULL, NOTIFY_DESTROY);
4419 	mutex_unlock(&notification_mutex);
4420 
4421 	mutex_lock(&resources_mutex);
4422 	list_del_rcu(&resource->resources);
4423 	mutex_unlock(&resources_mutex);
4424 	/* Make sure all threads have actually stopped: state handling only
4425 	 * does drbd_thread_stop_nowait(). */
4426 	list_for_each_entry(connection, &resource->connections, connections)
4427 		drbd_thread_stop(&connection->worker);
4428 	synchronize_rcu();
4429 	drbd_free_resource(resource);
4430 	return NO_ERROR;
4431 }
4432 
4433 int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
4434 {
4435 	struct drbd_config_context adm_ctx;
4436 	struct drbd_resource *resource;
4437 	struct drbd_connection *connection;
4438 	struct drbd_device *device;
4439 	int retcode; /* enum drbd_ret_code rsp. enum drbd_state_rv */
4440 	unsigned i;
4441 
4442 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);
4443 	if (!adm_ctx.reply_skb)
4444 		return retcode;
4445 	if (retcode != NO_ERROR)
4446 		goto finish;
4447 
4448 	resource = adm_ctx.resource;
4449 	mutex_lock(&resource->adm_mutex);
4450 	/* demote */
4451 	for_each_connection(connection, resource) {
4452 		struct drbd_peer_device *peer_device;
4453 
4454 		idr_for_each_entry(&connection->peer_devices, peer_device, i) {
4455 			retcode = drbd_set_role(peer_device->device, R_SECONDARY, 0);
4456 			if (retcode < SS_SUCCESS) {
4457 				drbd_msg_put_info(adm_ctx.reply_skb, "failed to demote");
4458 				goto out;
4459 			}
4460 		}
4461 
4462 		retcode = conn_try_disconnect(connection, 0);
4463 		if (retcode < SS_SUCCESS) {
4464 			drbd_msg_put_info(adm_ctx.reply_skb, "failed to disconnect");
4465 			goto out;
4466 		}
4467 	}
4468 
4469 	/* detach */
4470 	idr_for_each_entry(&resource->devices, device, i) {
4471 		retcode = adm_detach(device, 0);
4472 		if (retcode < SS_SUCCESS || retcode > NO_ERROR) {
4473 			drbd_msg_put_info(adm_ctx.reply_skb, "failed to detach");
4474 			goto out;
4475 		}
4476 	}
4477 
4478 	/* delete volumes */
4479 	idr_for_each_entry(&resource->devices, device, i) {
4480 		retcode = adm_del_minor(device);
4481 		if (retcode != NO_ERROR) {
4482 			/* "can not happen" */
4483 			drbd_msg_put_info(adm_ctx.reply_skb, "failed to delete volume");
4484 			goto out;
4485 		}
4486 	}
4487 
4488 	retcode = adm_del_resource(resource);
4489 out:
4490 	mutex_unlock(&resource->adm_mutex);
4491 finish:
4492 	drbd_adm_finish(&adm_ctx, info, retcode);
4493 	return 0;
4494 }
4495 
4496 int drbd_adm_del_resource(struct sk_buff *skb, struct genl_info *info)
4497 {
4498 	struct drbd_config_context adm_ctx;
4499 	struct drbd_resource *resource;
4500 	enum drbd_ret_code retcode;
4501 
4502 	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);
4503 	if (!adm_ctx.reply_skb)
4504 		return retcode;
4505 	if (retcode != NO_ERROR)
4506 		goto finish;
4507 	resource = adm_ctx.resource;
4508 
4509 	mutex_lock(&resource->adm_mutex);
4510 	retcode = adm_del_resource(resource);
4511 	mutex_unlock(&resource->adm_mutex);
4512 finish:
4513 	drbd_adm_finish(&adm_ctx, info, retcode);
4514 	return 0;
4515 }
4516 
4517 void drbd_bcast_event(struct drbd_device *device, const struct sib_info *sib)
4518 {
4519 	struct sk_buff *msg;
4520 	struct drbd_genlmsghdr *d_out;
4521 	unsigned seq;
4522 	int err = -ENOMEM;
4523 
4524 	seq = atomic_inc_return(&drbd_genl_seq);
4525 	msg = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
4526 	if (!msg)
4527 		goto failed;
4528 
4529 	err = -EMSGSIZE;
4530 	d_out = genlmsg_put(msg, 0, seq, &drbd_genl_family, 0, DRBD_EVENT);
4531 	if (!d_out) /* cannot happen, but anyways. */
4532 		goto nla_put_failure;
4533 	d_out->minor = device_to_minor(device);
4534 	d_out->ret_code = NO_ERROR;
4535 
4536 	if (nla_put_status_info(msg, device, sib))
4537 		goto nla_put_failure;
4538 	genlmsg_end(msg, d_out);
4539 	err = drbd_genl_multicast_events(msg, GFP_NOWAIT);
4540 	/* msg has been consumed or freed in netlink_broadcast() */
4541 	if (err && err != -ESRCH)
4542 		goto failed;
4543 
4544 	return;
4545 
4546 nla_put_failure:
4547 	nlmsg_free(msg);
4548 failed:
4549 	drbd_err(device, "Error %d while broadcasting event. "
4550 			"Event seq:%u sib_reason:%u\n",
4551 			err, seq, sib->sib_reason);
4552 }
4553 
4554 static int nla_put_notification_header(struct sk_buff *msg,
4555 				       enum drbd_notification_type type)
4556 {
4557 	struct drbd_notification_header nh = {
4558 		.nh_type = type,
4559 	};
4560 
4561 	return drbd_notification_header_to_skb(msg, &nh, true);
4562 }
4563 
4564 int notify_resource_state(struct sk_buff *skb,
4565 			   unsigned int seq,
4566 			   struct drbd_resource *resource,
4567 			   struct resource_info *resource_info,
4568 			   enum drbd_notification_type type)
4569 {
4570 	struct resource_statistics resource_statistics;
4571 	struct drbd_genlmsghdr *dh;
4572 	bool multicast = false;
4573 	int err;
4574 
4575 	if (!skb) {
4576 		seq = atomic_inc_return(&notify_genl_seq);
4577 		skb = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
4578 		err = -ENOMEM;
4579 		if (!skb)
4580 			goto failed;
4581 		multicast = true;
4582 	}
4583 
4584 	err = -EMSGSIZE;
4585 	dh = genlmsg_put(skb, 0, seq, &drbd_genl_family, 0, DRBD_RESOURCE_STATE);
4586 	if (!dh)
4587 		goto nla_put_failure;
4588 	dh->minor = -1U;
4589 	dh->ret_code = NO_ERROR;
4590 	if (nla_put_drbd_cfg_context(skb, resource, NULL, NULL) ||
4591 	    nla_put_notification_header(skb, type) ||
4592 	    ((type & ~NOTIFY_FLAGS) != NOTIFY_DESTROY &&
4593 	     resource_info_to_skb(skb, resource_info, true)))
4594 		goto nla_put_failure;
4595 	resource_statistics.res_stat_write_ordering = resource->write_ordering;
4596 	err = resource_statistics_to_skb(skb, &resource_statistics, !capable(CAP_SYS_ADMIN));
4597 	if (err)
4598 		goto nla_put_failure;
4599 	genlmsg_end(skb, dh);
4600 	if (multicast) {
4601 		err = drbd_genl_multicast_events(skb, GFP_NOWAIT);
4602 		/* skb has been consumed or freed in netlink_broadcast() */
4603 		if (err && err != -ESRCH)
4604 			goto failed;
4605 	}
4606 	return 0;
4607 
4608 nla_put_failure:
4609 	nlmsg_free(skb);
4610 failed:
4611 	drbd_err(resource, "Error %d while broadcasting event. Event seq:%u\n",
4612 			err, seq);
4613 	return err;
4614 }
4615 
4616 int notify_device_state(struct sk_buff *skb,
4617 			 unsigned int seq,
4618 			 struct drbd_device *device,
4619 			 struct device_info *device_info,
4620 			 enum drbd_notification_type type)
4621 {
4622 	struct device_statistics device_statistics;
4623 	struct drbd_genlmsghdr *dh;
4624 	bool multicast = false;
4625 	int err;
4626 
4627 	if (!skb) {
4628 		seq = atomic_inc_return(&notify_genl_seq);
4629 		skb = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
4630 		err = -ENOMEM;
4631 		if (!skb)
4632 			goto failed;
4633 		multicast = true;
4634 	}
4635 
4636 	err = -EMSGSIZE;
4637 	dh = genlmsg_put(skb, 0, seq, &drbd_genl_family, 0, DRBD_DEVICE_STATE);
4638 	if (!dh)
4639 		goto nla_put_failure;
4640 	dh->minor = device->minor;
4641 	dh->ret_code = NO_ERROR;
4642 	if (nla_put_drbd_cfg_context(skb, device->resource, NULL, device) ||
4643 	    nla_put_notification_header(skb, type) ||
4644 	    ((type & ~NOTIFY_FLAGS) != NOTIFY_DESTROY &&
4645 	     device_info_to_skb(skb, device_info, true)))
4646 		goto nla_put_failure;
4647 	device_to_statistics(&device_statistics, device);
4648 	device_statistics_to_skb(skb, &device_statistics, !capable(CAP_SYS_ADMIN));
4649 	genlmsg_end(skb, dh);
4650 	if (multicast) {
4651 		err = drbd_genl_multicast_events(skb, GFP_NOWAIT);
4652 		/* skb has been consumed or freed in netlink_broadcast() */
4653 		if (err && err != -ESRCH)
4654 			goto failed;
4655 	}
4656 	return 0;
4657 
4658 nla_put_failure:
4659 	nlmsg_free(skb);
4660 failed:
4661 	drbd_err(device, "Error %d while broadcasting event. Event seq:%u\n",
4662 		 err, seq);
4663 	return err;
4664 }
4665 
4666 int notify_connection_state(struct sk_buff *skb,
4667 			     unsigned int seq,
4668 			     struct drbd_connection *connection,
4669 			     struct connection_info *connection_info,
4670 			     enum drbd_notification_type type)
4671 {
4672 	struct connection_statistics connection_statistics;
4673 	struct drbd_genlmsghdr *dh;
4674 	bool multicast = false;
4675 	int err;
4676 
4677 	if (!skb) {
4678 		seq = atomic_inc_return(&notify_genl_seq);
4679 		skb = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
4680 		err = -ENOMEM;
4681 		if (!skb)
4682 			goto failed;
4683 		multicast = true;
4684 	}
4685 
4686 	err = -EMSGSIZE;
4687 	dh = genlmsg_put(skb, 0, seq, &drbd_genl_family, 0, DRBD_CONNECTION_STATE);
4688 	if (!dh)
4689 		goto nla_put_failure;
4690 	dh->minor = -1U;
4691 	dh->ret_code = NO_ERROR;
4692 	if (nla_put_drbd_cfg_context(skb, connection->resource, connection, NULL) ||
4693 	    nla_put_notification_header(skb, type) ||
4694 	    ((type & ~NOTIFY_FLAGS) != NOTIFY_DESTROY &&
4695 	     connection_info_to_skb(skb, connection_info, true)))
4696 		goto nla_put_failure;
4697 	connection_statistics.conn_congested = test_bit(NET_CONGESTED, &connection->flags);
4698 	connection_statistics_to_skb(skb, &connection_statistics, !capable(CAP_SYS_ADMIN));
4699 	genlmsg_end(skb, dh);
4700 	if (multicast) {
4701 		err = drbd_genl_multicast_events(skb, GFP_NOWAIT);
4702 		/* skb has been consumed or freed in netlink_broadcast() */
4703 		if (err && err != -ESRCH)
4704 			goto failed;
4705 	}
4706 	return 0;
4707 
4708 nla_put_failure:
4709 	nlmsg_free(skb);
4710 failed:
4711 	drbd_err(connection, "Error %d while broadcasting event. Event seq:%u\n",
4712 		 err, seq);
4713 	return err;
4714 }
4715 
4716 int notify_peer_device_state(struct sk_buff *skb,
4717 			      unsigned int seq,
4718 			      struct drbd_peer_device *peer_device,
4719 			      struct peer_device_info *peer_device_info,
4720 			      enum drbd_notification_type type)
4721 {
4722 	struct peer_device_statistics peer_device_statistics;
4723 	struct drbd_resource *resource = peer_device->device->resource;
4724 	struct drbd_genlmsghdr *dh;
4725 	bool multicast = false;
4726 	int err;
4727 
4728 	if (!skb) {
4729 		seq = atomic_inc_return(&notify_genl_seq);
4730 		skb = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
4731 		err = -ENOMEM;
4732 		if (!skb)
4733 			goto failed;
4734 		multicast = true;
4735 	}
4736 
4737 	err = -EMSGSIZE;
4738 	dh = genlmsg_put(skb, 0, seq, &drbd_genl_family, 0, DRBD_PEER_DEVICE_STATE);
4739 	if (!dh)
4740 		goto nla_put_failure;
4741 	dh->minor = -1U;
4742 	dh->ret_code = NO_ERROR;
4743 	if (nla_put_drbd_cfg_context(skb, resource, peer_device->connection, peer_device->device) ||
4744 	    nla_put_notification_header(skb, type) ||
4745 	    ((type & ~NOTIFY_FLAGS) != NOTIFY_DESTROY &&
4746 	     peer_device_info_to_skb(skb, peer_device_info, true)))
4747 		goto nla_put_failure;
4748 	peer_device_to_statistics(&peer_device_statistics, peer_device);
4749 	peer_device_statistics_to_skb(skb, &peer_device_statistics, !capable(CAP_SYS_ADMIN));
4750 	genlmsg_end(skb, dh);
4751 	if (multicast) {
4752 		err = drbd_genl_multicast_events(skb, GFP_NOWAIT);
4753 		/* skb has been consumed or freed in netlink_broadcast() */
4754 		if (err && err != -ESRCH)
4755 			goto failed;
4756 	}
4757 	return 0;
4758 
4759 nla_put_failure:
4760 	nlmsg_free(skb);
4761 failed:
4762 	drbd_err(peer_device, "Error %d while broadcasting event. Event seq:%u\n",
4763 		 err, seq);
4764 	return err;
4765 }
4766 
4767 void notify_helper(enum drbd_notification_type type,
4768 		   struct drbd_device *device, struct drbd_connection *connection,
4769 		   const char *name, int status)
4770 {
4771 	struct drbd_resource *resource = device ? device->resource : connection->resource;
4772 	struct drbd_helper_info helper_info;
4773 	unsigned int seq = atomic_inc_return(&notify_genl_seq);
4774 	struct sk_buff *skb = NULL;
4775 	struct drbd_genlmsghdr *dh;
4776 	int err;
4777 
4778 	strscpy(helper_info.helper_name, name, sizeof(helper_info.helper_name));
4779 	helper_info.helper_name_len = min(strlen(name), sizeof(helper_info.helper_name));
4780 	helper_info.helper_status = status;
4781 
4782 	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_NOIO);
4783 	err = -ENOMEM;
4784 	if (!skb)
4785 		goto fail;
4786 
4787 	err = -EMSGSIZE;
4788 	dh = genlmsg_put(skb, 0, seq, &drbd_genl_family, 0, DRBD_HELPER);
4789 	if (!dh)
4790 		goto fail;
4791 	dh->minor = device ? device->minor : -1;
4792 	dh->ret_code = NO_ERROR;
4793 	mutex_lock(&notification_mutex);
4794 	if (nla_put_drbd_cfg_context(skb, resource, connection, device) ||
4795 	    nla_put_notification_header(skb, type) ||
4796 	    drbd_helper_info_to_skb(skb, &helper_info, true))
4797 		goto unlock_fail;
4798 	genlmsg_end(skb, dh);
4799 	err = drbd_genl_multicast_events(skb, GFP_NOWAIT);
4800 	skb = NULL;
4801 	/* skb has been consumed or freed in netlink_broadcast() */
4802 	if (err && err != -ESRCH)
4803 		goto unlock_fail;
4804 	mutex_unlock(&notification_mutex);
4805 	return;
4806 
4807 unlock_fail:
4808 	mutex_unlock(&notification_mutex);
4809 fail:
4810 	nlmsg_free(skb);
4811 	drbd_err(resource, "Error %d while broadcasting event. Event seq:%u\n",
4812 		 err, seq);
4813 }
4814 
4815 static int notify_initial_state_done(struct sk_buff *skb, unsigned int seq)
4816 {
4817 	struct drbd_genlmsghdr *dh;
4818 	int err;
4819 
4820 	err = -EMSGSIZE;
4821 	dh = genlmsg_put(skb, 0, seq, &drbd_genl_family, 0, DRBD_INITIAL_STATE_DONE);
4822 	if (!dh)
4823 		goto nla_put_failure;
4824 	dh->minor = -1U;
4825 	dh->ret_code = NO_ERROR;
4826 	if (nla_put_notification_header(skb, NOTIFY_EXISTS))
4827 		goto nla_put_failure;
4828 	genlmsg_end(skb, dh);
4829 	return 0;
4830 
4831 nla_put_failure:
4832 	nlmsg_free(skb);
4833 	pr_err("Error %d sending event. Event seq:%u\n", err, seq);
4834 	return err;
4835 }
4836 
4837 static void free_state_changes(struct list_head *list)
4838 {
4839 	while (!list_empty(list)) {
4840 		struct drbd_state_change *state_change =
4841 			list_first_entry(list, struct drbd_state_change, list);
4842 		list_del(&state_change->list);
4843 		forget_state_change(state_change);
4844 	}
4845 }
4846 
4847 static unsigned int notifications_for_state_change(struct drbd_state_change *state_change)
4848 {
4849 	return 1 +
4850 	       state_change->n_connections +
4851 	       state_change->n_devices +
4852 	       state_change->n_devices * state_change->n_connections;
4853 }
4854 
4855 static int get_initial_state(struct sk_buff *skb, struct netlink_callback *cb)
4856 {
4857 	struct drbd_state_change *state_change = (struct drbd_state_change *)cb->args[0];
4858 	unsigned int seq = cb->args[2];
4859 	unsigned int n;
4860 	enum drbd_notification_type flags = 0;
4861 	int err = 0;
4862 
4863 	/* There is no need for taking notification_mutex here: it doesn't
4864 	   matter if the initial state events mix with later state chage
4865 	   events; we can always tell the events apart by the NOTIFY_EXISTS
4866 	   flag. */
4867 
4868 	cb->args[5]--;
4869 	if (cb->args[5] == 1) {
4870 		err = notify_initial_state_done(skb, seq);
4871 		goto out;
4872 	}
4873 	n = cb->args[4]++;
4874 	if (cb->args[4] < cb->args[3])
4875 		flags |= NOTIFY_CONTINUES;
4876 	if (n < 1) {
4877 		err = notify_resource_state_change(skb, seq, state_change->resource,
4878 					     NOTIFY_EXISTS | flags);
4879 		goto next;
4880 	}
4881 	n--;
4882 	if (n < state_change->n_connections) {
4883 		err = notify_connection_state_change(skb, seq, &state_change->connections[n],
4884 					       NOTIFY_EXISTS | flags);
4885 		goto next;
4886 	}
4887 	n -= state_change->n_connections;
4888 	if (n < state_change->n_devices) {
4889 		err = notify_device_state_change(skb, seq, &state_change->devices[n],
4890 					   NOTIFY_EXISTS | flags);
4891 		goto next;
4892 	}
4893 	n -= state_change->n_devices;
4894 	if (n < state_change->n_devices * state_change->n_connections) {
4895 		err = notify_peer_device_state_change(skb, seq, &state_change->peer_devices[n],
4896 						NOTIFY_EXISTS | flags);
4897 		goto next;
4898 	}
4899 
4900 next:
4901 	if (cb->args[4] == cb->args[3]) {
4902 		struct drbd_state_change *next_state_change =
4903 			list_entry(state_change->list.next,
4904 				   struct drbd_state_change, list);
4905 		cb->args[0] = (long)next_state_change;
4906 		cb->args[3] = notifications_for_state_change(next_state_change);
4907 		cb->args[4] = 0;
4908 	}
4909 out:
4910 	if (err)
4911 		return err;
4912 	else
4913 		return skb->len;
4914 }
4915 
4916 int drbd_adm_get_initial_state(struct sk_buff *skb, struct netlink_callback *cb)
4917 {
4918 	struct drbd_resource *resource;
4919 	LIST_HEAD(head);
4920 
4921 	if (cb->args[5] >= 1) {
4922 		if (cb->args[5] > 1)
4923 			return get_initial_state(skb, cb);
4924 		if (cb->args[0]) {
4925 			struct drbd_state_change *state_change =
4926 				(struct drbd_state_change *)cb->args[0];
4927 
4928 			/* connect list to head */
4929 			list_add(&head, &state_change->list);
4930 			free_state_changes(&head);
4931 		}
4932 		return 0;
4933 	}
4934 
4935 	cb->args[5] = 2;  /* number of iterations */
4936 	mutex_lock(&resources_mutex);
4937 	for_each_resource(resource, &drbd_resources) {
4938 		struct drbd_state_change *state_change;
4939 
4940 		state_change = remember_old_state(resource, GFP_KERNEL);
4941 		if (!state_change) {
4942 			if (!list_empty(&head))
4943 				free_state_changes(&head);
4944 			mutex_unlock(&resources_mutex);
4945 			return -ENOMEM;
4946 		}
4947 		copy_old_to_new_state_change(state_change);
4948 		list_add_tail(&state_change->list, &head);
4949 		cb->args[5] += notifications_for_state_change(state_change);
4950 	}
4951 	mutex_unlock(&resources_mutex);
4952 
4953 	if (!list_empty(&head)) {
4954 		struct drbd_state_change *state_change =
4955 			list_entry(head.next, struct drbd_state_change, list);
4956 		cb->args[0] = (long)state_change;
4957 		cb->args[3] = notifications_for_state_change(state_change);
4958 		list_del(&head);  /* detach list from head */
4959 	}
4960 
4961 	cb->args[2] = cb->nlh->nlmsg_seq;
4962 	return get_initial_state(skb, cb);
4963 }
4964