1// SPDX-License-Identifier: GPL-2.0-only
2/*
3   drbd_state.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   Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev
12   from Logicworks, Inc. for making SDP replication support possible.
13
14 */
15
16#include <linux/drbd_limits.h>
17#include "drbd_int.h"
18#include "drbd_protocol.h"
19#include "drbd_req.h"
20#include "drbd_state_change.h"
21
22struct after_state_chg_work {
23	struct drbd_work w;
24	struct drbd_device *device;
25	union drbd_state os;
26	union drbd_state ns;
27	enum chg_state_flags flags;
28	struct completion *done;
29	struct drbd_state_change *state_change;
30};
31
32enum sanitize_state_warnings {
33	NO_WARNING,
34	ABORTED_ONLINE_VERIFY,
35	ABORTED_RESYNC,
36	CONNECTION_LOST_NEGOTIATING,
37	IMPLICITLY_UPGRADED_DISK,
38	IMPLICITLY_UPGRADED_PDSK,
39};
40
41static void count_objects(struct drbd_resource *resource,
42			  unsigned int *n_devices,
43			  unsigned int *n_connections)
44{
45	struct drbd_device *device;
46	struct drbd_connection *connection;
47	int vnr;
48
49	*n_devices = 0;
50	*n_connections = 0;
51
52	idr_for_each_entry(&resource->devices, device, vnr)
53		(*n_devices)++;
54	for_each_connection(connection, resource)
55		(*n_connections)++;
56}
57
58static struct drbd_state_change *alloc_state_change(unsigned int n_devices, unsigned int n_connections, gfp_t gfp)
59{
60	struct drbd_state_change *state_change;
61	unsigned int size, n;
62
63	size = sizeof(struct drbd_state_change) +
64	       n_devices * sizeof(struct drbd_device_state_change) +
65	       n_connections * sizeof(struct drbd_connection_state_change) +
66	       n_devices * n_connections * sizeof(struct drbd_peer_device_state_change);
67	state_change = kmalloc(size, gfp);
68	if (!state_change)
69		return NULL;
70	state_change->n_devices = n_devices;
71	state_change->n_connections = n_connections;
72	state_change->devices = (void *)(state_change + 1);
73	state_change->connections = (void *)&state_change->devices[n_devices];
74	state_change->peer_devices = (void *)&state_change->connections[n_connections];
75	state_change->resource->resource = NULL;
76	for (n = 0; n < n_devices; n++)
77		state_change->devices[n].device = NULL;
78	for (n = 0; n < n_connections; n++)
79		state_change->connections[n].connection = NULL;
80	return state_change;
81}
82
83struct drbd_state_change *remember_old_state(struct drbd_resource *resource, gfp_t gfp)
84{
85	struct drbd_state_change *state_change;
86	struct drbd_device *device;
87	unsigned int n_devices;
88	struct drbd_connection *connection;
89	unsigned int n_connections;
90	int vnr;
91
92	struct drbd_device_state_change *device_state_change;
93	struct drbd_peer_device_state_change *peer_device_state_change;
94	struct drbd_connection_state_change *connection_state_change;
95
96	/* Caller holds req_lock spinlock.
97	 * No state, no device IDR, no connections lists can change. */
98	count_objects(resource, &n_devices, &n_connections);
99	state_change = alloc_state_change(n_devices, n_connections, gfp);
100	if (!state_change)
101		return NULL;
102
103	kref_get(&resource->kref);
104	state_change->resource->resource = resource;
105	state_change->resource->role[OLD] =
106		conn_highest_role(first_connection(resource));
107	state_change->resource->susp[OLD] = resource->susp;
108	state_change->resource->susp_nod[OLD] = resource->susp_nod;
109	state_change->resource->susp_fen[OLD] = resource->susp_fen;
110
111	connection_state_change = state_change->connections;
112	for_each_connection(connection, resource) {
113		kref_get(&connection->kref);
114		connection_state_change->connection = connection;
115		connection_state_change->cstate[OLD] =
116			connection->cstate;
117		connection_state_change->peer_role[OLD] =
118			conn_highest_peer(connection);
119		connection_state_change++;
120	}
121
122	device_state_change = state_change->devices;
123	peer_device_state_change = state_change->peer_devices;
124	idr_for_each_entry(&resource->devices, device, vnr) {
125		kref_get(&device->kref);
126		device_state_change->device = device;
127		device_state_change->disk_state[OLD] = device->state.disk;
128
129		/* The peer_devices for each device have to be enumerated in
130		   the order of the connections. We may not use for_each_peer_device() here. */
131		for_each_connection(connection, resource) {
132			struct drbd_peer_device *peer_device;
133
134			peer_device = conn_peer_device(connection, device->vnr);
135			peer_device_state_change->peer_device = peer_device;
136			peer_device_state_change->disk_state[OLD] =
137				device->state.pdsk;
138			peer_device_state_change->repl_state[OLD] =
139				max_t(enum drbd_conns,
140				      C_WF_REPORT_PARAMS, device->state.conn);
141			peer_device_state_change->resync_susp_user[OLD] =
142				device->state.user_isp;
143			peer_device_state_change->resync_susp_peer[OLD] =
144				device->state.peer_isp;
145			peer_device_state_change->resync_susp_dependency[OLD] =
146				device->state.aftr_isp;
147			peer_device_state_change++;
148		}
149		device_state_change++;
150	}
151
152	return state_change;
153}
154
155static void remember_new_state(struct drbd_state_change *state_change)
156{
157	struct drbd_resource_state_change *resource_state_change;
158	struct drbd_resource *resource;
159	unsigned int n;
160
161	if (!state_change)
162		return;
163
164	resource_state_change = &state_change->resource[0];
165	resource = resource_state_change->resource;
166
167	resource_state_change->role[NEW] =
168		conn_highest_role(first_connection(resource));
169	resource_state_change->susp[NEW] = resource->susp;
170	resource_state_change->susp_nod[NEW] = resource->susp_nod;
171	resource_state_change->susp_fen[NEW] = resource->susp_fen;
172
173	for (n = 0; n < state_change->n_devices; n++) {
174		struct drbd_device_state_change *device_state_change =
175			&state_change->devices[n];
176		struct drbd_device *device = device_state_change->device;
177
178		device_state_change->disk_state[NEW] = device->state.disk;
179	}
180
181	for (n = 0; n < state_change->n_connections; n++) {
182		struct drbd_connection_state_change *connection_state_change =
183			&state_change->connections[n];
184		struct drbd_connection *connection =
185			connection_state_change->connection;
186
187		connection_state_change->cstate[NEW] = connection->cstate;
188		connection_state_change->peer_role[NEW] =
189			conn_highest_peer(connection);
190	}
191
192	for (n = 0; n < state_change->n_devices * state_change->n_connections; n++) {
193		struct drbd_peer_device_state_change *peer_device_state_change =
194			&state_change->peer_devices[n];
195		struct drbd_device *device =
196			peer_device_state_change->peer_device->device;
197		union drbd_dev_state state = device->state;
198
199		peer_device_state_change->disk_state[NEW] = state.pdsk;
200		peer_device_state_change->repl_state[NEW] =
201			max_t(enum drbd_conns, C_WF_REPORT_PARAMS, state.conn);
202		peer_device_state_change->resync_susp_user[NEW] =
203			state.user_isp;
204		peer_device_state_change->resync_susp_peer[NEW] =
205			state.peer_isp;
206		peer_device_state_change->resync_susp_dependency[NEW] =
207			state.aftr_isp;
208	}
209}
210
211void copy_old_to_new_state_change(struct drbd_state_change *state_change)
212{
213	struct drbd_resource_state_change *resource_state_change = &state_change->resource[0];
214	unsigned int n_device, n_connection, n_peer_device, n_peer_devices;
215
216#define OLD_TO_NEW(x) \
217	(x[NEW] = x[OLD])
218
219	OLD_TO_NEW(resource_state_change->role);
220	OLD_TO_NEW(resource_state_change->susp);
221	OLD_TO_NEW(resource_state_change->susp_nod);
222	OLD_TO_NEW(resource_state_change->susp_fen);
223
224	for (n_connection = 0; n_connection < state_change->n_connections; n_connection++) {
225		struct drbd_connection_state_change *connection_state_change =
226				&state_change->connections[n_connection];
227
228		OLD_TO_NEW(connection_state_change->peer_role);
229		OLD_TO_NEW(connection_state_change->cstate);
230	}
231
232	for (n_device = 0; n_device < state_change->n_devices; n_device++) {
233		struct drbd_device_state_change *device_state_change =
234			&state_change->devices[n_device];
235
236		OLD_TO_NEW(device_state_change->disk_state);
237	}
238
239	n_peer_devices = state_change->n_devices * state_change->n_connections;
240	for (n_peer_device = 0; n_peer_device < n_peer_devices; n_peer_device++) {
241		struct drbd_peer_device_state_change *p =
242			&state_change->peer_devices[n_peer_device];
243
244		OLD_TO_NEW(p->disk_state);
245		OLD_TO_NEW(p->repl_state);
246		OLD_TO_NEW(p->resync_susp_user);
247		OLD_TO_NEW(p->resync_susp_peer);
248		OLD_TO_NEW(p->resync_susp_dependency);
249	}
250
251#undef OLD_TO_NEW
252}
253
254void forget_state_change(struct drbd_state_change *state_change)
255{
256	unsigned int n;
257
258	if (!state_change)
259		return;
260
261	if (state_change->resource->resource)
262		kref_put(&state_change->resource->resource->kref, drbd_destroy_resource);
263	for (n = 0; n < state_change->n_devices; n++) {
264		struct drbd_device *device = state_change->devices[n].device;
265
266		if (device)
267			kref_put(&device->kref, drbd_destroy_device);
268	}
269	for (n = 0; n < state_change->n_connections; n++) {
270		struct drbd_connection *connection =
271			state_change->connections[n].connection;
272
273		if (connection)
274			kref_put(&connection->kref, drbd_destroy_connection);
275	}
276	kfree(state_change);
277}
278
279static int w_after_state_ch(struct drbd_work *w, int unused);
280static void after_state_ch(struct drbd_device *device, union drbd_state os,
281			   union drbd_state ns, enum chg_state_flags flags,
282			   struct drbd_state_change *);
283static enum drbd_state_rv is_valid_state(struct drbd_device *, union drbd_state);
284static enum drbd_state_rv is_valid_soft_transition(union drbd_state, union drbd_state, struct drbd_connection *);
285static enum drbd_state_rv is_valid_transition(union drbd_state os, union drbd_state ns);
286static union drbd_state sanitize_state(struct drbd_device *device, union drbd_state os,
287				       union drbd_state ns, enum sanitize_state_warnings *warn);
288
289static inline bool is_susp(union drbd_state s)
290{
291        return s.susp || s.susp_nod || s.susp_fen;
292}
293
294bool conn_all_vols_unconf(struct drbd_connection *connection)
295{
296	struct drbd_peer_device *peer_device;
297	bool rv = true;
298	int vnr;
299
300	rcu_read_lock();
301	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
302		struct drbd_device *device = peer_device->device;
303		if (device->state.disk != D_DISKLESS ||
304		    device->state.conn != C_STANDALONE ||
305		    device->state.role != R_SECONDARY) {
306			rv = false;
307			break;
308		}
309	}
310	rcu_read_unlock();
311
312	return rv;
313}
314
315/* Unfortunately the states where not correctly ordered, when
316   they where defined. therefore can not use max_t() here. */
317static enum drbd_role max_role(enum drbd_role role1, enum drbd_role role2)
318{
319	if (role1 == R_PRIMARY || role2 == R_PRIMARY)
320		return R_PRIMARY;
321	if (role1 == R_SECONDARY || role2 == R_SECONDARY)
322		return R_SECONDARY;
323	return R_UNKNOWN;
324}
325
326static enum drbd_role min_role(enum drbd_role role1, enum drbd_role role2)
327{
328	if (role1 == R_UNKNOWN || role2 == R_UNKNOWN)
329		return R_UNKNOWN;
330	if (role1 == R_SECONDARY || role2 == R_SECONDARY)
331		return R_SECONDARY;
332	return R_PRIMARY;
333}
334
335enum drbd_role conn_highest_role(struct drbd_connection *connection)
336{
337	enum drbd_role role = R_SECONDARY;
338	struct drbd_peer_device *peer_device;
339	int vnr;
340
341	rcu_read_lock();
342	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
343		struct drbd_device *device = peer_device->device;
344		role = max_role(role, device->state.role);
345	}
346	rcu_read_unlock();
347
348	return role;
349}
350
351enum drbd_role conn_highest_peer(struct drbd_connection *connection)
352{
353	enum drbd_role peer = R_UNKNOWN;
354	struct drbd_peer_device *peer_device;
355	int vnr;
356
357	rcu_read_lock();
358	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
359		struct drbd_device *device = peer_device->device;
360		peer = max_role(peer, device->state.peer);
361	}
362	rcu_read_unlock();
363
364	return peer;
365}
366
367enum drbd_disk_state conn_highest_disk(struct drbd_connection *connection)
368{
369	enum drbd_disk_state disk_state = D_DISKLESS;
370	struct drbd_peer_device *peer_device;
371	int vnr;
372
373	rcu_read_lock();
374	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
375		struct drbd_device *device = peer_device->device;
376		disk_state = max_t(enum drbd_disk_state, disk_state, device->state.disk);
377	}
378	rcu_read_unlock();
379
380	return disk_state;
381}
382
383enum drbd_disk_state conn_lowest_disk(struct drbd_connection *connection)
384{
385	enum drbd_disk_state disk_state = D_MASK;
386	struct drbd_peer_device *peer_device;
387	int vnr;
388
389	rcu_read_lock();
390	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
391		struct drbd_device *device = peer_device->device;
392		disk_state = min_t(enum drbd_disk_state, disk_state, device->state.disk);
393	}
394	rcu_read_unlock();
395
396	return disk_state;
397}
398
399enum drbd_disk_state conn_highest_pdsk(struct drbd_connection *connection)
400{
401	enum drbd_disk_state disk_state = D_DISKLESS;
402	struct drbd_peer_device *peer_device;
403	int vnr;
404
405	rcu_read_lock();
406	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
407		struct drbd_device *device = peer_device->device;
408		disk_state = max_t(enum drbd_disk_state, disk_state, device->state.pdsk);
409	}
410	rcu_read_unlock();
411
412	return disk_state;
413}
414
415enum drbd_conns conn_lowest_conn(struct drbd_connection *connection)
416{
417	enum drbd_conns conn = C_MASK;
418	struct drbd_peer_device *peer_device;
419	int vnr;
420
421	rcu_read_lock();
422	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
423		struct drbd_device *device = peer_device->device;
424		conn = min_t(enum drbd_conns, conn, device->state.conn);
425	}
426	rcu_read_unlock();
427
428	return conn;
429}
430
431static bool no_peer_wf_report_params(struct drbd_connection *connection)
432{
433	struct drbd_peer_device *peer_device;
434	int vnr;
435	bool rv = true;
436
437	rcu_read_lock();
438	idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
439		if (peer_device->device->state.conn == C_WF_REPORT_PARAMS) {
440			rv = false;
441			break;
442		}
443	rcu_read_unlock();
444
445	return rv;
446}
447
448static void wake_up_all_devices(struct drbd_connection *connection)
449{
450	struct drbd_peer_device *peer_device;
451	int vnr;
452
453	rcu_read_lock();
454	idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
455		wake_up(&peer_device->device->state_wait);
456	rcu_read_unlock();
457
458}
459
460
461/**
462 * cl_wide_st_chg() - true if the state change is a cluster wide one
463 * @device:	DRBD device.
464 * @os:		old (current) state.
465 * @ns:		new (wanted) state.
466 */
467static int cl_wide_st_chg(struct drbd_device *device,
468			  union drbd_state os, union drbd_state ns)
469{
470	return (os.conn >= C_CONNECTED && ns.conn >= C_CONNECTED &&
471		 ((os.role != R_PRIMARY && ns.role == R_PRIMARY) ||
472		  (os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
473		  (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S) ||
474		  (os.disk != D_FAILED && ns.disk == D_FAILED))) ||
475		(os.conn >= C_CONNECTED && ns.conn == C_DISCONNECTING) ||
476		(os.conn == C_CONNECTED && ns.conn == C_VERIFY_S) ||
477		(os.conn == C_CONNECTED && ns.conn == C_WF_REPORT_PARAMS);
478}
479
480static union drbd_state
481apply_mask_val(union drbd_state os, union drbd_state mask, union drbd_state val)
482{
483	union drbd_state ns;
484	ns.i = (os.i & ~mask.i) | val.i;
485	return ns;
486}
487
488enum drbd_state_rv
489drbd_change_state(struct drbd_device *device, enum chg_state_flags f,
490		  union drbd_state mask, union drbd_state val)
491{
492	unsigned long flags;
493	union drbd_state ns;
494	enum drbd_state_rv rv;
495
496	spin_lock_irqsave(&device->resource->req_lock, flags);
497	ns = apply_mask_val(drbd_read_state(device), mask, val);
498	rv = _drbd_set_state(device, ns, f, NULL);
499	spin_unlock_irqrestore(&device->resource->req_lock, flags);
500
501	return rv;
502}
503
504/**
505 * drbd_force_state() - Impose a change which happens outside our control on our state
506 * @device:	DRBD device.
507 * @mask:	mask of state bits to change.
508 * @val:	value of new state bits.
509 */
510void drbd_force_state(struct drbd_device *device,
511	union drbd_state mask, union drbd_state val)
512{
513	drbd_change_state(device, CS_HARD, mask, val);
514}
515
516static enum drbd_state_rv
517_req_st_cond(struct drbd_device *device, union drbd_state mask,
518	     union drbd_state val)
519{
520	union drbd_state os, ns;
521	unsigned long flags;
522	enum drbd_state_rv rv;
523
524	if (test_and_clear_bit(CL_ST_CHG_SUCCESS, &device->flags))
525		return SS_CW_SUCCESS;
526
527	if (test_and_clear_bit(CL_ST_CHG_FAIL, &device->flags))
528		return SS_CW_FAILED_BY_PEER;
529
530	spin_lock_irqsave(&device->resource->req_lock, flags);
531	os = drbd_read_state(device);
532	ns = sanitize_state(device, os, apply_mask_val(os, mask, val), NULL);
533	rv = is_valid_transition(os, ns);
534	if (rv >= SS_SUCCESS)
535		rv = SS_UNKNOWN_ERROR;  /* cont waiting, otherwise fail. */
536
537	if (!cl_wide_st_chg(device, os, ns))
538		rv = SS_CW_NO_NEED;
539	if (rv == SS_UNKNOWN_ERROR) {
540		rv = is_valid_state(device, ns);
541		if (rv >= SS_SUCCESS) {
542			rv = is_valid_soft_transition(os, ns, first_peer_device(device)->connection);
543			if (rv >= SS_SUCCESS)
544				rv = SS_UNKNOWN_ERROR; /* cont waiting, otherwise fail. */
545		}
546	}
547	spin_unlock_irqrestore(&device->resource->req_lock, flags);
548
549	return rv;
550}
551
552/**
553 * drbd_req_state() - Perform an eventually cluster wide state change
554 * @device:	DRBD device.
555 * @mask:	mask of state bits to change.
556 * @val:	value of new state bits.
557 * @f:		flags
558 *
559 * Should not be called directly, use drbd_request_state() or
560 * _drbd_request_state().
561 */
562static enum drbd_state_rv
563drbd_req_state(struct drbd_device *device, union drbd_state mask,
564	       union drbd_state val, enum chg_state_flags f)
565{
566	struct completion done;
567	unsigned long flags;
568	union drbd_state os, ns;
569	enum drbd_state_rv rv;
570	void *buffer = NULL;
571
572	init_completion(&done);
573
574	if (f & CS_SERIALIZE)
575		mutex_lock(device->state_mutex);
576	if (f & CS_INHIBIT_MD_IO)
577		buffer = drbd_md_get_buffer(device, __func__);
578
579	spin_lock_irqsave(&device->resource->req_lock, flags);
580	os = drbd_read_state(device);
581	ns = sanitize_state(device, os, apply_mask_val(os, mask, val), NULL);
582	rv = is_valid_transition(os, ns);
583	if (rv < SS_SUCCESS) {
584		spin_unlock_irqrestore(&device->resource->req_lock, flags);
585		goto abort;
586	}
587
588	if (cl_wide_st_chg(device, os, ns)) {
589		rv = is_valid_state(device, ns);
590		if (rv == SS_SUCCESS)
591			rv = is_valid_soft_transition(os, ns, first_peer_device(device)->connection);
592		spin_unlock_irqrestore(&device->resource->req_lock, flags);
593
594		if (rv < SS_SUCCESS) {
595			if (f & CS_VERBOSE)
596				print_st_err(device, os, ns, rv);
597			goto abort;
598		}
599
600		if (drbd_send_state_req(first_peer_device(device), mask, val)) {
601			rv = SS_CW_FAILED_BY_PEER;
602			if (f & CS_VERBOSE)
603				print_st_err(device, os, ns, rv);
604			goto abort;
605		}
606
607		wait_event(device->state_wait,
608			(rv = _req_st_cond(device, mask, val)));
609
610		if (rv < SS_SUCCESS) {
611			if (f & CS_VERBOSE)
612				print_st_err(device, os, ns, rv);
613			goto abort;
614		}
615		spin_lock_irqsave(&device->resource->req_lock, flags);
616		ns = apply_mask_val(drbd_read_state(device), mask, val);
617		rv = _drbd_set_state(device, ns, f, &done);
618	} else {
619		rv = _drbd_set_state(device, ns, f, &done);
620	}
621
622	spin_unlock_irqrestore(&device->resource->req_lock, flags);
623
624	if (f & CS_WAIT_COMPLETE && rv == SS_SUCCESS) {
625		D_ASSERT(device, current != first_peer_device(device)->connection->worker.task);
626		wait_for_completion(&done);
627	}
628
629abort:
630	if (buffer)
631		drbd_md_put_buffer(device);
632	if (f & CS_SERIALIZE)
633		mutex_unlock(device->state_mutex);
634
635	return rv;
636}
637
638/**
639 * _drbd_request_state() - Request a state change (with flags)
640 * @device:	DRBD device.
641 * @mask:	mask of state bits to change.
642 * @val:	value of new state bits.
643 * @f:		flags
644 *
645 * Cousin of drbd_request_state(), useful with the CS_WAIT_COMPLETE
646 * flag, or when logging of failed state change requests is not desired.
647 */
648enum drbd_state_rv
649_drbd_request_state(struct drbd_device *device, union drbd_state mask,
650		    union drbd_state val, enum chg_state_flags f)
651{
652	enum drbd_state_rv rv;
653
654	wait_event(device->state_wait,
655		   (rv = drbd_req_state(device, mask, val, f)) != SS_IN_TRANSIENT_STATE);
656
657	return rv;
658}
659
660/*
661 * We grab drbd_md_get_buffer(), because we don't want to "fail" the disk while
662 * there is IO in-flight: the transition into D_FAILED for detach purposes
663 * may get misinterpreted as actual IO error in a confused endio function.
664 *
665 * We wrap it all into wait_event(), to retry in case the drbd_req_state()
666 * returns SS_IN_TRANSIENT_STATE.
667 *
668 * To avoid potential deadlock with e.g. the receiver thread trying to grab
669 * drbd_md_get_buffer() while trying to get out of the "transient state", we
670 * need to grab and release the meta data buffer inside of that wait_event loop.
671 */
672static enum drbd_state_rv
673request_detach(struct drbd_device *device)
674{
675	return drbd_req_state(device, NS(disk, D_FAILED),
676			CS_VERBOSE | CS_ORDERED | CS_INHIBIT_MD_IO);
677}
678
679int drbd_request_detach_interruptible(struct drbd_device *device)
680{
681	int ret, rv;
682
683	drbd_suspend_io(device); /* so no-one is stuck in drbd_al_begin_io */
684	wait_event_interruptible(device->state_wait,
685		(rv = request_detach(device)) != SS_IN_TRANSIENT_STATE);
686	drbd_resume_io(device);
687
688	ret = wait_event_interruptible(device->misc_wait,
689			device->state.disk != D_FAILED);
690
691	if (rv == SS_IS_DISKLESS)
692		rv = SS_NOTHING_TO_DO;
693	if (ret)
694		rv = ERR_INTR;
695
696	return rv;
697}
698
699enum drbd_state_rv
700_drbd_request_state_holding_state_mutex(struct drbd_device *device, union drbd_state mask,
701		    union drbd_state val, enum chg_state_flags f)
702{
703	enum drbd_state_rv rv;
704
705	BUG_ON(f & CS_SERIALIZE);
706
707	wait_event_cmd(device->state_wait,
708		       (rv = drbd_req_state(device, mask, val, f)) != SS_IN_TRANSIENT_STATE,
709		       mutex_unlock(device->state_mutex),
710		       mutex_lock(device->state_mutex));
711
712	return rv;
713}
714
715static void print_st(struct drbd_device *device, const char *name, union drbd_state ns)
716{
717	drbd_err(device, " %s = { cs:%s ro:%s/%s ds:%s/%s %c%c%c%c%c%c }\n",
718	    name,
719	    drbd_conn_str(ns.conn),
720	    drbd_role_str(ns.role),
721	    drbd_role_str(ns.peer),
722	    drbd_disk_str(ns.disk),
723	    drbd_disk_str(ns.pdsk),
724	    is_susp(ns) ? 's' : 'r',
725	    ns.aftr_isp ? 'a' : '-',
726	    ns.peer_isp ? 'p' : '-',
727	    ns.user_isp ? 'u' : '-',
728	    ns.susp_fen ? 'F' : '-',
729	    ns.susp_nod ? 'N' : '-'
730	    );
731}
732
733void print_st_err(struct drbd_device *device, union drbd_state os,
734	          union drbd_state ns, enum drbd_state_rv err)
735{
736	if (err == SS_IN_TRANSIENT_STATE)
737		return;
738	drbd_err(device, "State change failed: %s\n", drbd_set_st_err_str(err));
739	print_st(device, " state", os);
740	print_st(device, "wanted", ns);
741}
742
743static long print_state_change(char *pb, union drbd_state os, union drbd_state ns,
744			       enum chg_state_flags flags)
745{
746	char *pbp;
747	pbp = pb;
748	*pbp = 0;
749
750	if (ns.role != os.role && flags & CS_DC_ROLE)
751		pbp += sprintf(pbp, "role( %s -> %s ) ",
752			       drbd_role_str(os.role),
753			       drbd_role_str(ns.role));
754	if (ns.peer != os.peer && flags & CS_DC_PEER)
755		pbp += sprintf(pbp, "peer( %s -> %s ) ",
756			       drbd_role_str(os.peer),
757			       drbd_role_str(ns.peer));
758	if (ns.conn != os.conn && flags & CS_DC_CONN)
759		pbp += sprintf(pbp, "conn( %s -> %s ) ",
760			       drbd_conn_str(os.conn),
761			       drbd_conn_str(ns.conn));
762	if (ns.disk != os.disk && flags & CS_DC_DISK)
763		pbp += sprintf(pbp, "disk( %s -> %s ) ",
764			       drbd_disk_str(os.disk),
765			       drbd_disk_str(ns.disk));
766	if (ns.pdsk != os.pdsk && flags & CS_DC_PDSK)
767		pbp += sprintf(pbp, "pdsk( %s -> %s ) ",
768			       drbd_disk_str(os.pdsk),
769			       drbd_disk_str(ns.pdsk));
770
771	return pbp - pb;
772}
773
774static void drbd_pr_state_change(struct drbd_device *device, union drbd_state os, union drbd_state ns,
775				 enum chg_state_flags flags)
776{
777	char pb[300];
778	char *pbp = pb;
779
780	pbp += print_state_change(pbp, os, ns, flags ^ CS_DC_MASK);
781
782	if (ns.aftr_isp != os.aftr_isp)
783		pbp += sprintf(pbp, "aftr_isp( %d -> %d ) ",
784			       os.aftr_isp,
785			       ns.aftr_isp);
786	if (ns.peer_isp != os.peer_isp)
787		pbp += sprintf(pbp, "peer_isp( %d -> %d ) ",
788			       os.peer_isp,
789			       ns.peer_isp);
790	if (ns.user_isp != os.user_isp)
791		pbp += sprintf(pbp, "user_isp( %d -> %d ) ",
792			       os.user_isp,
793			       ns.user_isp);
794
795	if (pbp != pb)
796		drbd_info(device, "%s\n", pb);
797}
798
799static void conn_pr_state_change(struct drbd_connection *connection, union drbd_state os, union drbd_state ns,
800				 enum chg_state_flags flags)
801{
802	char pb[300];
803	char *pbp = pb;
804
805	pbp += print_state_change(pbp, os, ns, flags);
806
807	if (is_susp(ns) != is_susp(os) && flags & CS_DC_SUSP)
808		pbp += sprintf(pbp, "susp( %d -> %d ) ",
809			       is_susp(os),
810			       is_susp(ns));
811
812	if (pbp != pb)
813		drbd_info(connection, "%s\n", pb);
814}
815
816
817/**
818 * is_valid_state() - Returns an SS_ error code if ns is not valid
819 * @device:	DRBD device.
820 * @ns:		State to consider.
821 */
822static enum drbd_state_rv
823is_valid_state(struct drbd_device *device, union drbd_state ns)
824{
825	/* See drbd_state_sw_errors in drbd_strings.c */
826
827	enum drbd_fencing_p fp;
828	enum drbd_state_rv rv = SS_SUCCESS;
829	struct net_conf *nc;
830
831	rcu_read_lock();
832	fp = FP_DONT_CARE;
833	if (get_ldev(device)) {
834		fp = rcu_dereference(device->ldev->disk_conf)->fencing;
835		put_ldev(device);
836	}
837
838	nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
839	if (nc) {
840		if (!nc->two_primaries && ns.role == R_PRIMARY) {
841			if (ns.peer == R_PRIMARY)
842				rv = SS_TWO_PRIMARIES;
843			else if (conn_highest_peer(first_peer_device(device)->connection) == R_PRIMARY)
844				rv = SS_O_VOL_PEER_PRI;
845		}
846	}
847
848	if (rv <= 0)
849		goto out; /* already found a reason to abort */
850	else if (ns.role == R_SECONDARY && device->open_cnt)
851		rv = SS_DEVICE_IN_USE;
852
853	else if (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.disk < D_UP_TO_DATE)
854		rv = SS_NO_UP_TO_DATE_DISK;
855
856	else if (fp >= FP_RESOURCE &&
857		 ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk >= D_UNKNOWN)
858		rv = SS_PRIMARY_NOP;
859
860	else if (ns.role == R_PRIMARY && ns.disk <= D_INCONSISTENT && ns.pdsk <= D_INCONSISTENT)
861		rv = SS_NO_UP_TO_DATE_DISK;
862
863	else if (ns.conn > C_CONNECTED && ns.disk < D_INCONSISTENT)
864		rv = SS_NO_LOCAL_DISK;
865
866	else if (ns.conn > C_CONNECTED && ns.pdsk < D_INCONSISTENT)
867		rv = SS_NO_REMOTE_DISK;
868
869	else if (ns.conn > C_CONNECTED && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)
870		rv = SS_NO_UP_TO_DATE_DISK;
871
872	else if ((ns.conn == C_CONNECTED ||
873		  ns.conn == C_WF_BITMAP_S ||
874		  ns.conn == C_SYNC_SOURCE ||
875		  ns.conn == C_PAUSED_SYNC_S) &&
876		  ns.disk == D_OUTDATED)
877		rv = SS_CONNECTED_OUTDATES;
878
879	else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
880		 (nc->verify_alg[0] == 0))
881		rv = SS_NO_VERIFY_ALG;
882
883	else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
884		  first_peer_device(device)->connection->agreed_pro_version < 88)
885		rv = SS_NOT_SUPPORTED;
886
887	else if (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)
888		rv = SS_NO_UP_TO_DATE_DISK;
889
890	else if ((ns.conn == C_STARTING_SYNC_S || ns.conn == C_STARTING_SYNC_T) &&
891                 ns.pdsk == D_UNKNOWN)
892		rv = SS_NEED_CONNECTION;
893
894	else if (ns.conn >= C_CONNECTED && ns.pdsk == D_UNKNOWN)
895		rv = SS_CONNECTED_OUTDATES;
896
897out:
898	rcu_read_unlock();
899
900	return rv;
901}
902
903/**
904 * is_valid_soft_transition() - Returns an SS_ error code if the state transition is not possible
905 * This function limits state transitions that may be declined by DRBD. I.e.
906 * user requests (aka soft transitions).
907 * @os:		old state.
908 * @ns:		new state.
909 * @connection:  DRBD connection.
910 */
911static enum drbd_state_rv
912is_valid_soft_transition(union drbd_state os, union drbd_state ns, struct drbd_connection *connection)
913{
914	enum drbd_state_rv rv = SS_SUCCESS;
915
916	if ((ns.conn == C_STARTING_SYNC_T || ns.conn == C_STARTING_SYNC_S) &&
917	    os.conn > C_CONNECTED)
918		rv = SS_RESYNC_RUNNING;
919
920	if (ns.conn == C_DISCONNECTING && os.conn == C_STANDALONE)
921		rv = SS_ALREADY_STANDALONE;
922
923	if (ns.disk > D_ATTACHING && os.disk == D_DISKLESS)
924		rv = SS_IS_DISKLESS;
925
926	if (ns.conn == C_WF_CONNECTION && os.conn < C_UNCONNECTED)
927		rv = SS_NO_NET_CONFIG;
928
929	if (ns.disk == D_OUTDATED && os.disk < D_OUTDATED && os.disk != D_ATTACHING)
930		rv = SS_LOWER_THAN_OUTDATED;
931
932	if (ns.conn == C_DISCONNECTING && os.conn == C_UNCONNECTED)
933		rv = SS_IN_TRANSIENT_STATE;
934
935	/* While establishing a connection only allow cstate to change.
936	   Delay/refuse role changes, detach attach etc... (they do not touch cstate) */
937	if (test_bit(STATE_SENT, &connection->flags) &&
938	    !((ns.conn == C_WF_REPORT_PARAMS && os.conn == C_WF_CONNECTION) ||
939	      (ns.conn >= C_CONNECTED && os.conn == C_WF_REPORT_PARAMS)))
940		rv = SS_IN_TRANSIENT_STATE;
941
942	/* Do not promote during resync handshake triggered by "force primary".
943	 * This is a hack. It should really be rejected by the peer during the
944	 * cluster wide state change request. */
945	if (os.role != R_PRIMARY && ns.role == R_PRIMARY
946		&& ns.pdsk == D_UP_TO_DATE
947		&& ns.disk != D_UP_TO_DATE && ns.disk != D_DISKLESS
948		&& (ns.conn <= C_WF_SYNC_UUID || ns.conn != os.conn))
949			rv = SS_IN_TRANSIENT_STATE;
950
951	if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && os.conn < C_CONNECTED)
952		rv = SS_NEED_CONNECTION;
953
954	if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
955	    ns.conn != os.conn && os.conn > C_CONNECTED)
956		rv = SS_RESYNC_RUNNING;
957
958	if ((ns.conn == C_STARTING_SYNC_S || ns.conn == C_STARTING_SYNC_T) &&
959	    os.conn < C_CONNECTED)
960		rv = SS_NEED_CONNECTION;
961
962	if ((ns.conn == C_SYNC_TARGET || ns.conn == C_SYNC_SOURCE)
963	    && os.conn < C_WF_REPORT_PARAMS)
964		rv = SS_NEED_CONNECTION; /* No NetworkFailure -> SyncTarget etc... */
965
966	if (ns.conn == C_DISCONNECTING && ns.pdsk == D_OUTDATED &&
967	    os.conn < C_CONNECTED && os.pdsk > D_OUTDATED)
968		rv = SS_OUTDATE_WO_CONN;
969
970	return rv;
971}
972
973static enum drbd_state_rv
974is_valid_conn_transition(enum drbd_conns oc, enum drbd_conns nc)
975{
976	/* no change -> nothing to do, at least for the connection part */
977	if (oc == nc)
978		return SS_NOTHING_TO_DO;
979
980	/* disconnect of an unconfigured connection does not make sense */
981	if (oc == C_STANDALONE && nc == C_DISCONNECTING)
982		return SS_ALREADY_STANDALONE;
983
984	/* from C_STANDALONE, we start with C_UNCONNECTED */
985	if (oc == C_STANDALONE && nc != C_UNCONNECTED)
986		return SS_NEED_CONNECTION;
987
988	/* When establishing a connection we need to go through WF_REPORT_PARAMS!
989	   Necessary to do the right thing upon invalidate-remote on a disconnected resource */
990	if (oc < C_WF_REPORT_PARAMS && nc >= C_CONNECTED)
991		return SS_NEED_CONNECTION;
992
993	/* After a network error only C_UNCONNECTED or C_DISCONNECTING may follow. */
994	if (oc >= C_TIMEOUT && oc <= C_TEAR_DOWN && nc != C_UNCONNECTED && nc != C_DISCONNECTING)
995		return SS_IN_TRANSIENT_STATE;
996
997	/* After C_DISCONNECTING only C_STANDALONE may follow */
998	if (oc == C_DISCONNECTING && nc != C_STANDALONE)
999		return SS_IN_TRANSIENT_STATE;
1000
1001	return SS_SUCCESS;
1002}
1003
1004
1005/**
1006 * is_valid_transition() - Returns an SS_ error code if the state transition is not possible
1007 * This limits hard state transitions. Hard state transitions are facts there are
1008 * imposed on DRBD by the environment. E.g. disk broke or network broke down.
1009 * But those hard state transitions are still not allowed to do everything.
1010 * @ns:		new state.
1011 * @os:		old state.
1012 */
1013static enum drbd_state_rv
1014is_valid_transition(union drbd_state os, union drbd_state ns)
1015{
1016	enum drbd_state_rv rv;
1017
1018	rv = is_valid_conn_transition(os.conn, ns.conn);
1019
1020	/* we cannot fail (again) if we already detached */
1021	if (ns.disk == D_FAILED && os.disk == D_DISKLESS)
1022		rv = SS_IS_DISKLESS;
1023
1024	return rv;
1025}
1026
1027static void print_sanitize_warnings(struct drbd_device *device, enum sanitize_state_warnings warn)
1028{
1029	static const char *msg_table[] = {
1030		[NO_WARNING] = "",
1031		[ABORTED_ONLINE_VERIFY] = "Online-verify aborted.",
1032		[ABORTED_RESYNC] = "Resync aborted.",
1033		[CONNECTION_LOST_NEGOTIATING] = "Connection lost while negotiating, no data!",
1034		[IMPLICITLY_UPGRADED_DISK] = "Implicitly upgraded disk",
1035		[IMPLICITLY_UPGRADED_PDSK] = "Implicitly upgraded pdsk",
1036	};
1037
1038	if (warn != NO_WARNING)
1039		drbd_warn(device, "%s\n", msg_table[warn]);
1040}
1041
1042/**
1043 * sanitize_state() - Resolves implicitly necessary additional changes to a state transition
1044 * @device:	DRBD device.
1045 * @os:		old state.
1046 * @ns:		new state.
1047 * @warn:	placeholder for returned state warning.
1048 *
1049 * When we loose connection, we have to set the state of the peers disk (pdsk)
1050 * to D_UNKNOWN. This rule and many more along those lines are in this function.
1051 */
1052static union drbd_state sanitize_state(struct drbd_device *device, union drbd_state os,
1053				       union drbd_state ns, enum sanitize_state_warnings *warn)
1054{
1055	enum drbd_fencing_p fp;
1056	enum drbd_disk_state disk_min, disk_max, pdsk_min, pdsk_max;
1057
1058	if (warn)
1059		*warn = NO_WARNING;
1060
1061	fp = FP_DONT_CARE;
1062	if (get_ldev(device)) {
1063		rcu_read_lock();
1064		fp = rcu_dereference(device->ldev->disk_conf)->fencing;
1065		rcu_read_unlock();
1066		put_ldev(device);
1067	}
1068
1069	/* Implications from connection to peer and peer_isp */
1070	if (ns.conn < C_CONNECTED) {
1071		ns.peer_isp = 0;
1072		ns.peer = R_UNKNOWN;
1073		if (ns.pdsk > D_UNKNOWN || ns.pdsk < D_INCONSISTENT)
1074			ns.pdsk = D_UNKNOWN;
1075	}
1076
1077	/* Clear the aftr_isp when becoming unconfigured */
1078	if (ns.conn == C_STANDALONE && ns.disk == D_DISKLESS && ns.role == R_SECONDARY)
1079		ns.aftr_isp = 0;
1080
1081	/* An implication of the disk states onto the connection state */
1082	/* Abort resync if a disk fails/detaches */
1083	if (ns.conn > C_CONNECTED && (ns.disk <= D_FAILED || ns.pdsk <= D_FAILED)) {
1084		if (warn)
1085			*warn = ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T ?
1086				ABORTED_ONLINE_VERIFY : ABORTED_RESYNC;
1087		ns.conn = C_CONNECTED;
1088	}
1089
1090	/* Connection breaks down before we finished "Negotiating" */
1091	if (ns.conn < C_CONNECTED && ns.disk == D_NEGOTIATING &&
1092	    get_ldev_if_state(device, D_NEGOTIATING)) {
1093		if (device->ed_uuid == device->ldev->md.uuid[UI_CURRENT]) {
1094			ns.disk = device->new_state_tmp.disk;
1095			ns.pdsk = device->new_state_tmp.pdsk;
1096		} else {
1097			if (warn)
1098				*warn = CONNECTION_LOST_NEGOTIATING;
1099			ns.disk = D_DISKLESS;
1100			ns.pdsk = D_UNKNOWN;
1101		}
1102		put_ldev(device);
1103	}
1104
1105	/* D_CONSISTENT and D_OUTDATED vanish when we get connected */
1106	if (ns.conn >= C_CONNECTED && ns.conn < C_AHEAD) {
1107		if (ns.disk == D_CONSISTENT || ns.disk == D_OUTDATED)
1108			ns.disk = D_UP_TO_DATE;
1109		if (ns.pdsk == D_CONSISTENT || ns.pdsk == D_OUTDATED)
1110			ns.pdsk = D_UP_TO_DATE;
1111	}
1112
1113	/* Implications of the connection state on the disk states */
1114	disk_min = D_DISKLESS;
1115	disk_max = D_UP_TO_DATE;
1116	pdsk_min = D_INCONSISTENT;
1117	pdsk_max = D_UNKNOWN;
1118	switch ((enum drbd_conns)ns.conn) {
1119	case C_WF_BITMAP_T:
1120	case C_PAUSED_SYNC_T:
1121	case C_STARTING_SYNC_T:
1122	case C_WF_SYNC_UUID:
1123	case C_BEHIND:
1124		disk_min = D_INCONSISTENT;
1125		disk_max = D_OUTDATED;
1126		pdsk_min = D_UP_TO_DATE;
1127		pdsk_max = D_UP_TO_DATE;
1128		break;
1129	case C_VERIFY_S:
1130	case C_VERIFY_T:
1131		disk_min = D_UP_TO_DATE;
1132		disk_max = D_UP_TO_DATE;
1133		pdsk_min = D_UP_TO_DATE;
1134		pdsk_max = D_UP_TO_DATE;
1135		break;
1136	case C_CONNECTED:
1137		disk_min = D_DISKLESS;
1138		disk_max = D_UP_TO_DATE;
1139		pdsk_min = D_DISKLESS;
1140		pdsk_max = D_UP_TO_DATE;
1141		break;
1142	case C_WF_BITMAP_S:
1143	case C_PAUSED_SYNC_S:
1144	case C_STARTING_SYNC_S:
1145	case C_AHEAD:
1146		disk_min = D_UP_TO_DATE;
1147		disk_max = D_UP_TO_DATE;
1148		pdsk_min = D_INCONSISTENT;
1149		pdsk_max = D_CONSISTENT; /* D_OUTDATED would be nice. But explicit outdate necessary*/
1150		break;
1151	case C_SYNC_TARGET:
1152		disk_min = D_INCONSISTENT;
1153		disk_max = D_INCONSISTENT;
1154		pdsk_min = D_UP_TO_DATE;
1155		pdsk_max = D_UP_TO_DATE;
1156		break;
1157	case C_SYNC_SOURCE:
1158		disk_min = D_UP_TO_DATE;
1159		disk_max = D_UP_TO_DATE;
1160		pdsk_min = D_INCONSISTENT;
1161		pdsk_max = D_INCONSISTENT;
1162		break;
1163	case C_STANDALONE:
1164	case C_DISCONNECTING:
1165	case C_UNCONNECTED:
1166	case C_TIMEOUT:
1167	case C_BROKEN_PIPE:
1168	case C_NETWORK_FAILURE:
1169	case C_PROTOCOL_ERROR:
1170	case C_TEAR_DOWN:
1171	case C_WF_CONNECTION:
1172	case C_WF_REPORT_PARAMS:
1173	case C_MASK:
1174		break;
1175	}
1176	if (ns.disk > disk_max)
1177		ns.disk = disk_max;
1178
1179	if (ns.disk < disk_min) {
1180		if (warn)
1181			*warn = IMPLICITLY_UPGRADED_DISK;
1182		ns.disk = disk_min;
1183	}
1184	if (ns.pdsk > pdsk_max)
1185		ns.pdsk = pdsk_max;
1186
1187	if (ns.pdsk < pdsk_min) {
1188		if (warn)
1189			*warn = IMPLICITLY_UPGRADED_PDSK;
1190		ns.pdsk = pdsk_min;
1191	}
1192
1193	if (fp == FP_STONITH &&
1194	    (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk > D_OUTDATED) &&
1195	    !(os.role == R_PRIMARY && os.conn < C_CONNECTED && os.pdsk > D_OUTDATED))
1196		ns.susp_fen = 1; /* Suspend IO while fence-peer handler runs (peer lost) */
1197
1198	if (device->resource->res_opts.on_no_data == OND_SUSPEND_IO &&
1199	    (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE) &&
1200	    !(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE))
1201		ns.susp_nod = 1; /* Suspend IO while no data available (no accessible data available) */
1202
1203	if (ns.aftr_isp || ns.peer_isp || ns.user_isp) {
1204		if (ns.conn == C_SYNC_SOURCE)
1205			ns.conn = C_PAUSED_SYNC_S;
1206		if (ns.conn == C_SYNC_TARGET)
1207			ns.conn = C_PAUSED_SYNC_T;
1208	} else {
1209		if (ns.conn == C_PAUSED_SYNC_S)
1210			ns.conn = C_SYNC_SOURCE;
1211		if (ns.conn == C_PAUSED_SYNC_T)
1212			ns.conn = C_SYNC_TARGET;
1213	}
1214
1215	return ns;
1216}
1217
1218void drbd_resume_al(struct drbd_device *device)
1219{
1220	if (test_and_clear_bit(AL_SUSPENDED, &device->flags))
1221		drbd_info(device, "Resumed AL updates\n");
1222}
1223
1224/* helper for _drbd_set_state */
1225static void set_ov_position(struct drbd_peer_device *peer_device, enum drbd_conns cs)
1226{
1227	struct drbd_device *device = peer_device->device;
1228
1229	if (peer_device->connection->agreed_pro_version < 90)
1230		device->ov_start_sector = 0;
1231	device->rs_total = drbd_bm_bits(device);
1232	device->ov_position = 0;
1233	if (cs == C_VERIFY_T) {
1234		/* starting online verify from an arbitrary position
1235		 * does not fit well into the existing protocol.
1236		 * on C_VERIFY_T, we initialize ov_left and friends
1237		 * implicitly in receive_DataRequest once the
1238		 * first P_OV_REQUEST is received */
1239		device->ov_start_sector = ~(sector_t)0;
1240	} else {
1241		unsigned long bit = BM_SECT_TO_BIT(device->ov_start_sector);
1242		if (bit >= device->rs_total) {
1243			device->ov_start_sector =
1244				BM_BIT_TO_SECT(device->rs_total - 1);
1245			device->rs_total = 1;
1246		} else
1247			device->rs_total -= bit;
1248		device->ov_position = device->ov_start_sector;
1249	}
1250	device->ov_left = device->rs_total;
1251}
1252
1253/**
1254 * _drbd_set_state() - Set a new DRBD state
1255 * @device:	DRBD device.
1256 * @ns:		new state.
1257 * @flags:	Flags
1258 * @done:	Optional completion, that will get completed after the after_state_ch() finished
1259 *
1260 * Caller needs to hold req_lock. Do not call directly.
1261 */
1262enum drbd_state_rv
1263_drbd_set_state(struct drbd_device *device, union drbd_state ns,
1264	        enum chg_state_flags flags, struct completion *done)
1265{
1266	struct drbd_peer_device *peer_device = first_peer_device(device);
1267	struct drbd_connection *connection = peer_device ? peer_device->connection : NULL;
1268	union drbd_state os;
1269	enum drbd_state_rv rv = SS_SUCCESS;
1270	enum sanitize_state_warnings ssw;
1271	struct after_state_chg_work *ascw;
1272	struct drbd_state_change *state_change;
1273
1274	os = drbd_read_state(device);
1275
1276	ns = sanitize_state(device, os, ns, &ssw);
1277	if (ns.i == os.i)
1278		return SS_NOTHING_TO_DO;
1279
1280	rv = is_valid_transition(os, ns);
1281	if (rv < SS_SUCCESS)
1282		return rv;
1283
1284	if (!(flags & CS_HARD)) {
1285		/*  pre-state-change checks ; only look at ns  */
1286		/* See drbd_state_sw_errors in drbd_strings.c */
1287
1288		rv = is_valid_state(device, ns);
1289		if (rv < SS_SUCCESS) {
1290			/* If the old state was illegal as well, then let
1291			   this happen...*/
1292
1293			if (is_valid_state(device, os) == rv)
1294				rv = is_valid_soft_transition(os, ns, connection);
1295		} else
1296			rv = is_valid_soft_transition(os, ns, connection);
1297	}
1298
1299	if (rv < SS_SUCCESS) {
1300		if (flags & CS_VERBOSE)
1301			print_st_err(device, os, ns, rv);
1302		return rv;
1303	}
1304
1305	print_sanitize_warnings(device, ssw);
1306
1307	drbd_pr_state_change(device, os, ns, flags);
1308
1309	/* Display changes to the susp* flags that where caused by the call to
1310	   sanitize_state(). Only display it here if we where not called from
1311	   _conn_request_state() */
1312	if (!(flags & CS_DC_SUSP))
1313		conn_pr_state_change(connection, os, ns,
1314				     (flags & ~CS_DC_MASK) | CS_DC_SUSP);
1315
1316	/* if we are going -> D_FAILED or D_DISKLESS, grab one extra reference
1317	 * on the ldev here, to be sure the transition -> D_DISKLESS resp.
1318	 * drbd_ldev_destroy() won't happen before our corresponding
1319	 * after_state_ch works run, where we put_ldev again. */
1320	if ((os.disk != D_FAILED && ns.disk == D_FAILED) ||
1321	    (os.disk != D_DISKLESS && ns.disk == D_DISKLESS))
1322		atomic_inc(&device->local_cnt);
1323
1324	if (!is_sync_state(os.conn) && is_sync_state(ns.conn))
1325		clear_bit(RS_DONE, &device->flags);
1326
1327	/* FIXME: Have any flags been set earlier in this function already? */
1328	state_change = remember_old_state(device->resource, GFP_ATOMIC);
1329
1330	/* changes to local_cnt and device flags should be visible before
1331	 * changes to state, which again should be visible before anything else
1332	 * depending on that change happens. */
1333	smp_wmb();
1334	device->state.i = ns.i;
1335	device->resource->susp = ns.susp;
1336	device->resource->susp_nod = ns.susp_nod;
1337	device->resource->susp_fen = ns.susp_fen;
1338	smp_wmb();
1339
1340	remember_new_state(state_change);
1341
1342	/* put replicated vs not-replicated requests in seperate epochs */
1343	if (drbd_should_do_remote((union drbd_dev_state)os.i) !=
1344	    drbd_should_do_remote((union drbd_dev_state)ns.i))
1345		start_new_tl_epoch(connection);
1346
1347	if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
1348		drbd_print_uuids(device, "attached to UUIDs");
1349
1350	/* Wake up role changes, that were delayed because of connection establishing */
1351	if (os.conn == C_WF_REPORT_PARAMS && ns.conn != C_WF_REPORT_PARAMS &&
1352	    no_peer_wf_report_params(connection)) {
1353		clear_bit(STATE_SENT, &connection->flags);
1354		wake_up_all_devices(connection);
1355	}
1356
1357	wake_up(&device->misc_wait);
1358	wake_up(&device->state_wait);
1359	wake_up(&connection->ping_wait);
1360
1361	/* Aborted verify run, or we reached the stop sector.
1362	 * Log the last position, unless end-of-device. */
1363	if ((os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) &&
1364	    ns.conn <= C_CONNECTED) {
1365		device->ov_start_sector =
1366			BM_BIT_TO_SECT(drbd_bm_bits(device) - device->ov_left);
1367		if (device->ov_left)
1368			drbd_info(device, "Online Verify reached sector %llu\n",
1369				(unsigned long long)device->ov_start_sector);
1370	}
1371
1372	if ((os.conn == C_PAUSED_SYNC_T || os.conn == C_PAUSED_SYNC_S) &&
1373	    (ns.conn == C_SYNC_TARGET  || ns.conn == C_SYNC_SOURCE)) {
1374		drbd_info(device, "Syncer continues.\n");
1375		device->rs_paused += (long)jiffies
1376				  -(long)device->rs_mark_time[device->rs_last_mark];
1377		if (ns.conn == C_SYNC_TARGET)
1378			mod_timer(&device->resync_timer, jiffies);
1379	}
1380
1381	if ((os.conn == C_SYNC_TARGET  || os.conn == C_SYNC_SOURCE) &&
1382	    (ns.conn == C_PAUSED_SYNC_T || ns.conn == C_PAUSED_SYNC_S)) {
1383		drbd_info(device, "Resync suspended\n");
1384		device->rs_mark_time[device->rs_last_mark] = jiffies;
1385	}
1386
1387	if (os.conn == C_CONNECTED &&
1388	    (ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T)) {
1389		unsigned long now = jiffies;
1390		int i;
1391
1392		set_ov_position(peer_device, ns.conn);
1393		device->rs_start = now;
1394		device->rs_last_sect_ev = 0;
1395		device->ov_last_oos_size = 0;
1396		device->ov_last_oos_start = 0;
1397
1398		for (i = 0; i < DRBD_SYNC_MARKS; i++) {
1399			device->rs_mark_left[i] = device->ov_left;
1400			device->rs_mark_time[i] = now;
1401		}
1402
1403		drbd_rs_controller_reset(peer_device);
1404
1405		if (ns.conn == C_VERIFY_S) {
1406			drbd_info(device, "Starting Online Verify from sector %llu\n",
1407					(unsigned long long)device->ov_position);
1408			mod_timer(&device->resync_timer, jiffies);
1409		}
1410	}
1411
1412	if (get_ldev(device)) {
1413		u32 mdf = device->ldev->md.flags & ~(MDF_CONSISTENT|MDF_PRIMARY_IND|
1414						 MDF_CONNECTED_IND|MDF_WAS_UP_TO_DATE|
1415						 MDF_PEER_OUT_DATED|MDF_CRASHED_PRIMARY);
1416
1417		mdf &= ~MDF_AL_CLEAN;
1418		if (test_bit(CRASHED_PRIMARY, &device->flags))
1419			mdf |= MDF_CRASHED_PRIMARY;
1420		if (device->state.role == R_PRIMARY ||
1421		    (device->state.pdsk < D_INCONSISTENT && device->state.peer == R_PRIMARY))
1422			mdf |= MDF_PRIMARY_IND;
1423		if (device->state.conn > C_WF_REPORT_PARAMS)
1424			mdf |= MDF_CONNECTED_IND;
1425		if (device->state.disk > D_INCONSISTENT)
1426			mdf |= MDF_CONSISTENT;
1427		if (device->state.disk > D_OUTDATED)
1428			mdf |= MDF_WAS_UP_TO_DATE;
1429		if (device->state.pdsk <= D_OUTDATED && device->state.pdsk >= D_INCONSISTENT)
1430			mdf |= MDF_PEER_OUT_DATED;
1431		if (mdf != device->ldev->md.flags) {
1432			device->ldev->md.flags = mdf;
1433			drbd_md_mark_dirty(device);
1434		}
1435		if (os.disk < D_CONSISTENT && ns.disk >= D_CONSISTENT)
1436			drbd_set_ed_uuid(device, device->ldev->md.uuid[UI_CURRENT]);
1437		put_ldev(device);
1438	}
1439
1440	/* Peer was forced D_UP_TO_DATE & R_PRIMARY, consider to resync */
1441	if (os.disk == D_INCONSISTENT && os.pdsk == D_INCONSISTENT &&
1442	    os.peer == R_SECONDARY && ns.peer == R_PRIMARY)
1443		set_bit(CONSIDER_RESYNC, &device->flags);
1444
1445	/* Receiver should clean up itself */
1446	if (os.conn != C_DISCONNECTING && ns.conn == C_DISCONNECTING)
1447		drbd_thread_stop_nowait(&connection->receiver);
1448
1449	/* Now the receiver finished cleaning up itself, it should die */
1450	if (os.conn != C_STANDALONE && ns.conn == C_STANDALONE)
1451		drbd_thread_stop_nowait(&connection->receiver);
1452
1453	/* Upon network failure, we need to restart the receiver. */
1454	if (os.conn > C_WF_CONNECTION &&
1455	    ns.conn <= C_TEAR_DOWN && ns.conn >= C_TIMEOUT)
1456		drbd_thread_restart_nowait(&connection->receiver);
1457
1458	/* Resume AL writing if we get a connection */
1459	if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED) {
1460		drbd_resume_al(device);
1461		connection->connect_cnt++;
1462	}
1463
1464	/* remember last attach time so request_timer_fn() won't
1465	 * kill newly established sessions while we are still trying to thaw
1466	 * previously frozen IO */
1467	if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
1468	    ns.disk > D_NEGOTIATING)
1469		device->last_reattach_jif = jiffies;
1470
1471	ascw = kmalloc(sizeof(*ascw), GFP_ATOMIC);
1472	if (ascw) {
1473		ascw->os = os;
1474		ascw->ns = ns;
1475		ascw->flags = flags;
1476		ascw->w.cb = w_after_state_ch;
1477		ascw->device = device;
1478		ascw->done = done;
1479		ascw->state_change = state_change;
1480		drbd_queue_work(&connection->sender_work,
1481				&ascw->w);
1482	} else {
1483		drbd_err(device, "Could not kmalloc an ascw\n");
1484	}
1485
1486	return rv;
1487}
1488
1489static int w_after_state_ch(struct drbd_work *w, int unused)
1490{
1491	struct after_state_chg_work *ascw =
1492		container_of(w, struct after_state_chg_work, w);
1493	struct drbd_device *device = ascw->device;
1494
1495	after_state_ch(device, ascw->os, ascw->ns, ascw->flags, ascw->state_change);
1496	forget_state_change(ascw->state_change);
1497	if (ascw->flags & CS_WAIT_COMPLETE)
1498		complete(ascw->done);
1499	kfree(ascw);
1500
1501	return 0;
1502}
1503
1504static void abw_start_sync(struct drbd_device *device, int rv)
1505{
1506	if (rv) {
1507		drbd_err(device, "Writing the bitmap failed not starting resync.\n");
1508		_drbd_request_state(device, NS(conn, C_CONNECTED), CS_VERBOSE);
1509		return;
1510	}
1511
1512	switch (device->state.conn) {
1513	case C_STARTING_SYNC_T:
1514		_drbd_request_state(device, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
1515		break;
1516	case C_STARTING_SYNC_S:
1517		drbd_start_resync(device, C_SYNC_SOURCE);
1518		break;
1519	}
1520}
1521
1522int drbd_bitmap_io_from_worker(struct drbd_device *device,
1523		int (*io_fn)(struct drbd_device *, struct drbd_peer_device *),
1524		char *why, enum bm_flag flags,
1525		struct drbd_peer_device *peer_device)
1526{
1527	int rv;
1528
1529	D_ASSERT(device, current == first_peer_device(device)->connection->worker.task);
1530
1531	/* open coded non-blocking drbd_suspend_io(device); */
1532	atomic_inc(&device->suspend_cnt);
1533
1534	drbd_bm_lock(device, why, flags);
1535	rv = io_fn(device, peer_device);
1536	drbd_bm_unlock(device);
1537
1538	drbd_resume_io(device);
1539
1540	return rv;
1541}
1542
1543int notify_resource_state_change(struct sk_buff *skb,
1544				  unsigned int seq,
1545				  void *state_change,
1546				  enum drbd_notification_type type)
1547{
1548	struct drbd_resource_state_change *resource_state_change = state_change;
1549	struct drbd_resource *resource = resource_state_change->resource;
1550	struct resource_info resource_info = {
1551		.res_role = resource_state_change->role[NEW],
1552		.res_susp = resource_state_change->susp[NEW],
1553		.res_susp_nod = resource_state_change->susp_nod[NEW],
1554		.res_susp_fen = resource_state_change->susp_fen[NEW],
1555	};
1556
1557	return notify_resource_state(skb, seq, resource, &resource_info, type);
1558}
1559
1560int notify_connection_state_change(struct sk_buff *skb,
1561				    unsigned int seq,
1562				    void *state_change,
1563				    enum drbd_notification_type type)
1564{
1565	struct drbd_connection_state_change *p = state_change;
1566	struct drbd_connection *connection = p->connection;
1567	struct connection_info connection_info = {
1568		.conn_connection_state = p->cstate[NEW],
1569		.conn_role = p->peer_role[NEW],
1570	};
1571
1572	return notify_connection_state(skb, seq, connection, &connection_info, type);
1573}
1574
1575int notify_device_state_change(struct sk_buff *skb,
1576				unsigned int seq,
1577				void *state_change,
1578				enum drbd_notification_type type)
1579{
1580	struct drbd_device_state_change *device_state_change = state_change;
1581	struct drbd_device *device = device_state_change->device;
1582	struct device_info device_info = {
1583		.dev_disk_state = device_state_change->disk_state[NEW],
1584	};
1585
1586	return notify_device_state(skb, seq, device, &device_info, type);
1587}
1588
1589int notify_peer_device_state_change(struct sk_buff *skb,
1590				     unsigned int seq,
1591				     void *state_change,
1592				     enum drbd_notification_type type)
1593{
1594	struct drbd_peer_device_state_change *p = state_change;
1595	struct drbd_peer_device *peer_device = p->peer_device;
1596	struct peer_device_info peer_device_info = {
1597		.peer_repl_state = p->repl_state[NEW],
1598		.peer_disk_state = p->disk_state[NEW],
1599		.peer_resync_susp_user = p->resync_susp_user[NEW],
1600		.peer_resync_susp_peer = p->resync_susp_peer[NEW],
1601		.peer_resync_susp_dependency = p->resync_susp_dependency[NEW],
1602	};
1603
1604	return notify_peer_device_state(skb, seq, peer_device, &peer_device_info, type);
1605}
1606
1607static void broadcast_state_change(struct drbd_state_change *state_change)
1608{
1609	struct drbd_resource_state_change *resource_state_change = &state_change->resource[0];
1610	bool resource_state_has_changed;
1611	unsigned int n_device, n_connection, n_peer_device, n_peer_devices;
1612	int (*last_func)(struct sk_buff *, unsigned int,
1613		void *, enum drbd_notification_type) = NULL;
1614	void *last_arg = NULL;
1615
1616#define HAS_CHANGED(state) ((state)[OLD] != (state)[NEW])
1617#define FINAL_STATE_CHANGE(type) \
1618	({ if (last_func) \
1619		last_func(NULL, 0, last_arg, type); \
1620	})
1621#define REMEMBER_STATE_CHANGE(func, arg, type) \
1622	({ FINAL_STATE_CHANGE(type | NOTIFY_CONTINUES); \
1623	   last_func = func; \
1624	   last_arg = arg; \
1625	 })
1626
1627	mutex_lock(&notification_mutex);
1628
1629	resource_state_has_changed =
1630	    HAS_CHANGED(resource_state_change->role) ||
1631	    HAS_CHANGED(resource_state_change->susp) ||
1632	    HAS_CHANGED(resource_state_change->susp_nod) ||
1633	    HAS_CHANGED(resource_state_change->susp_fen);
1634
1635	if (resource_state_has_changed)
1636		REMEMBER_STATE_CHANGE(notify_resource_state_change,
1637				      resource_state_change, NOTIFY_CHANGE);
1638
1639	for (n_connection = 0; n_connection < state_change->n_connections; n_connection++) {
1640		struct drbd_connection_state_change *connection_state_change =
1641				&state_change->connections[n_connection];
1642
1643		if (HAS_CHANGED(connection_state_change->peer_role) ||
1644		    HAS_CHANGED(connection_state_change->cstate))
1645			REMEMBER_STATE_CHANGE(notify_connection_state_change,
1646					      connection_state_change, NOTIFY_CHANGE);
1647	}
1648
1649	for (n_device = 0; n_device < state_change->n_devices; n_device++) {
1650		struct drbd_device_state_change *device_state_change =
1651			&state_change->devices[n_device];
1652
1653		if (HAS_CHANGED(device_state_change->disk_state))
1654			REMEMBER_STATE_CHANGE(notify_device_state_change,
1655					      device_state_change, NOTIFY_CHANGE);
1656	}
1657
1658	n_peer_devices = state_change->n_devices * state_change->n_connections;
1659	for (n_peer_device = 0; n_peer_device < n_peer_devices; n_peer_device++) {
1660		struct drbd_peer_device_state_change *p =
1661			&state_change->peer_devices[n_peer_device];
1662
1663		if (HAS_CHANGED(p->disk_state) ||
1664		    HAS_CHANGED(p->repl_state) ||
1665		    HAS_CHANGED(p->resync_susp_user) ||
1666		    HAS_CHANGED(p->resync_susp_peer) ||
1667		    HAS_CHANGED(p->resync_susp_dependency))
1668			REMEMBER_STATE_CHANGE(notify_peer_device_state_change,
1669					      p, NOTIFY_CHANGE);
1670	}
1671
1672	FINAL_STATE_CHANGE(NOTIFY_CHANGE);
1673	mutex_unlock(&notification_mutex);
1674
1675#undef HAS_CHANGED
1676#undef FINAL_STATE_CHANGE
1677#undef REMEMBER_STATE_CHANGE
1678}
1679
1680/* takes old and new peer disk state */
1681static bool lost_contact_to_peer_data(enum drbd_disk_state os, enum drbd_disk_state ns)
1682{
1683	if ((os >= D_INCONSISTENT && os != D_UNKNOWN && os != D_OUTDATED)
1684	&&  (ns < D_INCONSISTENT || ns == D_UNKNOWN || ns == D_OUTDATED))
1685		return true;
1686
1687	/* Scenario, starting with normal operation
1688	 * Connected Primary/Secondary UpToDate/UpToDate
1689	 * NetworkFailure Primary/Unknown UpToDate/DUnknown (frozen)
1690	 * ...
1691	 * Connected Primary/Secondary UpToDate/Diskless (resumed; needs to bump uuid!)
1692	 */
1693	if (os == D_UNKNOWN
1694	&&  (ns == D_DISKLESS || ns == D_FAILED || ns == D_OUTDATED))
1695		return true;
1696
1697	return false;
1698}
1699
1700/**
1701 * after_state_ch() - Perform after state change actions that may sleep
1702 * @device:	DRBD device.
1703 * @os:		old state.
1704 * @ns:		new state.
1705 * @flags:	Flags
1706 * @state_change: state change to broadcast
1707 */
1708static void after_state_ch(struct drbd_device *device, union drbd_state os,
1709			   union drbd_state ns, enum chg_state_flags flags,
1710			   struct drbd_state_change *state_change)
1711{
1712	struct drbd_resource *resource = device->resource;
1713	struct drbd_peer_device *peer_device = first_peer_device(device);
1714	struct drbd_connection *connection = peer_device ? peer_device->connection : NULL;
1715	struct sib_info sib;
1716
1717	broadcast_state_change(state_change);
1718
1719	sib.sib_reason = SIB_STATE_CHANGE;
1720	sib.os = os;
1721	sib.ns = ns;
1722
1723	if ((os.disk != D_UP_TO_DATE || os.pdsk != D_UP_TO_DATE)
1724	&&  (ns.disk == D_UP_TO_DATE && ns.pdsk == D_UP_TO_DATE)) {
1725		clear_bit(CRASHED_PRIMARY, &device->flags);
1726		if (device->p_uuid)
1727			device->p_uuid[UI_FLAGS] &= ~((u64)2);
1728	}
1729
1730	/* Inform userspace about the change... */
1731	drbd_bcast_event(device, &sib);
1732
1733	if (!(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE) &&
1734	    (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE))
1735		drbd_khelper(device, "pri-on-incon-degr");
1736
1737	/* Here we have the actions that are performed after a
1738	   state change. This function might sleep */
1739
1740	if (ns.susp_nod) {
1741		enum drbd_req_event what = NOTHING;
1742
1743		spin_lock_irq(&device->resource->req_lock);
1744		if (os.conn < C_CONNECTED && conn_lowest_conn(connection) >= C_CONNECTED)
1745			what = RESEND;
1746
1747		if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
1748		    conn_lowest_disk(connection) == D_UP_TO_DATE)
1749			what = RESTART_FROZEN_DISK_IO;
1750
1751		if (resource->susp_nod && what != NOTHING) {
1752			_tl_restart(connection, what);
1753			_conn_request_state(connection,
1754					    (union drbd_state) { { .susp_nod = 1 } },
1755					    (union drbd_state) { { .susp_nod = 0 } },
1756					    CS_VERBOSE);
1757		}
1758		spin_unlock_irq(&device->resource->req_lock);
1759	}
1760
1761	if (ns.susp_fen) {
1762		spin_lock_irq(&device->resource->req_lock);
1763		if (resource->susp_fen && conn_lowest_conn(connection) >= C_CONNECTED) {
1764			/* case2: The connection was established again: */
1765			struct drbd_peer_device *peer_device;
1766			int vnr;
1767
1768			rcu_read_lock();
1769			idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
1770				clear_bit(NEW_CUR_UUID, &peer_device->device->flags);
1771			rcu_read_unlock();
1772
1773			/* We should actively create a new uuid, _before_
1774			 * we resume/resent, if the peer is diskless
1775			 * (recovery from a multiple error scenario).
1776			 * Currently, this happens with a slight delay
1777			 * below when checking lost_contact_to_peer_data() ...
1778			 */
1779			_tl_restart(connection, RESEND);
1780			_conn_request_state(connection,
1781					    (union drbd_state) { { .susp_fen = 1 } },
1782					    (union drbd_state) { { .susp_fen = 0 } },
1783					    CS_VERBOSE);
1784		}
1785		spin_unlock_irq(&device->resource->req_lock);
1786	}
1787
1788	/* Became sync source.  With protocol >= 96, we still need to send out
1789	 * the sync uuid now. Need to do that before any drbd_send_state, or
1790	 * the other side may go "paused sync" before receiving the sync uuids,
1791	 * which is unexpected. */
1792	if ((os.conn != C_SYNC_SOURCE && os.conn != C_PAUSED_SYNC_S) &&
1793	    (ns.conn == C_SYNC_SOURCE || ns.conn == C_PAUSED_SYNC_S) &&
1794	    connection->agreed_pro_version >= 96 && get_ldev(device)) {
1795		drbd_gen_and_send_sync_uuid(peer_device);
1796		put_ldev(device);
1797	}
1798
1799	/* Do not change the order of the if above and the two below... */
1800	if (os.pdsk == D_DISKLESS &&
1801	    ns.pdsk > D_DISKLESS && ns.pdsk != D_UNKNOWN) {      /* attach on the peer */
1802		/* we probably will start a resync soon.
1803		 * make sure those things are properly reset. */
1804		device->rs_total = 0;
1805		device->rs_failed = 0;
1806		atomic_set(&device->rs_pending_cnt, 0);
1807		drbd_rs_cancel_all(device);
1808
1809		drbd_send_uuids(peer_device);
1810		drbd_send_state(peer_device, ns);
1811	}
1812	/* No point in queuing send_bitmap if we don't have a connection
1813	 * anymore, so check also the _current_ state, not only the new state
1814	 * at the time this work was queued. */
1815	if (os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S &&
1816	    device->state.conn == C_WF_BITMAP_S)
1817		drbd_queue_bitmap_io(device, &drbd_send_bitmap, NULL,
1818				"send_bitmap (WFBitMapS)",
1819				BM_LOCKED_TEST_ALLOWED, peer_device);
1820
1821	/* Lost contact to peer's copy of the data */
1822	if (lost_contact_to_peer_data(os.pdsk, ns.pdsk)) {
1823		if (get_ldev(device)) {
1824			if ((ns.role == R_PRIMARY || ns.peer == R_PRIMARY) &&
1825			    device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
1826				if (drbd_suspended(device)) {
1827					set_bit(NEW_CUR_UUID, &device->flags);
1828				} else {
1829					drbd_uuid_new_current(device);
1830					drbd_send_uuids(peer_device);
1831				}
1832			}
1833			put_ldev(device);
1834		}
1835	}
1836
1837	if (ns.pdsk < D_INCONSISTENT && get_ldev(device)) {
1838		if (os.peer != R_PRIMARY && ns.peer == R_PRIMARY &&
1839		    device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
1840			drbd_uuid_new_current(device);
1841			drbd_send_uuids(peer_device);
1842		}
1843		/* D_DISKLESS Peer becomes secondary */
1844		if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY)
1845			/* We may still be Primary ourselves.
1846			 * No harm done if the bitmap still changes,
1847			 * redirtied pages will follow later. */
1848			drbd_bitmap_io_from_worker(device, &drbd_bm_write,
1849				"demote diskless peer", BM_LOCKED_SET_ALLOWED, peer_device);
1850		put_ldev(device);
1851	}
1852
1853	/* Write out all changed bits on demote.
1854	 * Though, no need to da that just yet
1855	 * if there is a resync going on still */
1856	if (os.role == R_PRIMARY && ns.role == R_SECONDARY &&
1857		device->state.conn <= C_CONNECTED && get_ldev(device)) {
1858		/* No changes to the bitmap expected this time, so assert that,
1859		 * even though no harm was done if it did change. */
1860		drbd_bitmap_io_from_worker(device, &drbd_bm_write,
1861				"demote", BM_LOCKED_TEST_ALLOWED, peer_device);
1862		put_ldev(device);
1863	}
1864
1865	/* Last part of the attaching process ... */
1866	if (ns.conn >= C_CONNECTED &&
1867	    os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) {
1868		drbd_send_sizes(peer_device, 0, 0);  /* to start sync... */
1869		drbd_send_uuids(peer_device);
1870		drbd_send_state(peer_device, ns);
1871	}
1872
1873	/* We want to pause/continue resync, tell peer. */
1874	if (ns.conn >= C_CONNECTED &&
1875	     ((os.aftr_isp != ns.aftr_isp) ||
1876	      (os.user_isp != ns.user_isp)))
1877		drbd_send_state(peer_device, ns);
1878
1879	/* In case one of the isp bits got set, suspend other devices. */
1880	if ((!os.aftr_isp && !os.peer_isp && !os.user_isp) &&
1881	    (ns.aftr_isp || ns.peer_isp || ns.user_isp))
1882		suspend_other_sg(device);
1883
1884	/* Make sure the peer gets informed about eventual state
1885	   changes (ISP bits) while we were in WFReportParams. */
1886	if (os.conn == C_WF_REPORT_PARAMS && ns.conn >= C_CONNECTED)
1887		drbd_send_state(peer_device, ns);
1888
1889	if (os.conn != C_AHEAD && ns.conn == C_AHEAD)
1890		drbd_send_state(peer_device, ns);
1891
1892	/* We are in the progress to start a full sync... */
1893	if ((os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
1894	    (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S))
1895		/* no other bitmap changes expected during this phase */
1896		drbd_queue_bitmap_io(device,
1897			&drbd_bmio_set_n_write, &abw_start_sync,
1898			"set_n_write from StartingSync", BM_LOCKED_TEST_ALLOWED,
1899			peer_device);
1900
1901	/* first half of local IO error, failure to attach,
1902	 * or administrative detach */
1903	if (os.disk != D_FAILED && ns.disk == D_FAILED) {
1904		enum drbd_io_error_p eh = EP_PASS_ON;
1905		int was_io_error = 0;
1906		/* corresponding get_ldev was in _drbd_set_state, to serialize
1907		 * our cleanup here with the transition to D_DISKLESS.
1908		 * But is is still not save to dreference ldev here, since
1909		 * we might come from an failed Attach before ldev was set. */
1910		if (device->ldev) {
1911			rcu_read_lock();
1912			eh = rcu_dereference(device->ldev->disk_conf)->on_io_error;
1913			rcu_read_unlock();
1914
1915			was_io_error = test_and_clear_bit(WAS_IO_ERROR, &device->flags);
1916
1917			/* Intentionally call this handler first, before drbd_send_state().
1918			 * See: 2932204 drbd: call local-io-error handler early
1919			 * People may chose to hard-reset the box from this handler.
1920			 * It is useful if this looks like a "regular node crash". */
1921			if (was_io_error && eh == EP_CALL_HELPER)
1922				drbd_khelper(device, "local-io-error");
1923
1924			/* Immediately allow completion of all application IO,
1925			 * that waits for completion from the local disk,
1926			 * if this was a force-detach due to disk_timeout
1927			 * or administrator request (drbdsetup detach --force).
1928			 * Do NOT abort otherwise.
1929			 * Aborting local requests may cause serious problems,
1930			 * if requests are completed to upper layers already,
1931			 * and then later the already submitted local bio completes.
1932			 * This can cause DMA into former bio pages that meanwhile
1933			 * have been re-used for other things.
1934			 * So aborting local requests may cause crashes,
1935			 * or even worse, silent data corruption.
1936			 */
1937			if (test_and_clear_bit(FORCE_DETACH, &device->flags))
1938				tl_abort_disk_io(device);
1939
1940			/* current state still has to be D_FAILED,
1941			 * there is only one way out: to D_DISKLESS,
1942			 * and that may only happen after our put_ldev below. */
1943			if (device->state.disk != D_FAILED)
1944				drbd_err(device,
1945					"ASSERT FAILED: disk is %s during detach\n",
1946					drbd_disk_str(device->state.disk));
1947
1948			if (ns.conn >= C_CONNECTED)
1949				drbd_send_state(peer_device, ns);
1950
1951			drbd_rs_cancel_all(device);
1952
1953			/* In case we want to get something to stable storage still,
1954			 * this may be the last chance.
1955			 * Following put_ldev may transition to D_DISKLESS. */
1956			drbd_md_sync(device);
1957		}
1958		put_ldev(device);
1959	}
1960
1961	/* second half of local IO error, failure to attach,
1962	 * or administrative detach,
1963	 * after local_cnt references have reached zero again */
1964	if (os.disk != D_DISKLESS && ns.disk == D_DISKLESS) {
1965		/* We must still be diskless,
1966		 * re-attach has to be serialized with this! */
1967		if (device->state.disk != D_DISKLESS)
1968			drbd_err(device,
1969				 "ASSERT FAILED: disk is %s while going diskless\n",
1970				 drbd_disk_str(device->state.disk));
1971
1972		if (ns.conn >= C_CONNECTED)
1973			drbd_send_state(peer_device, ns);
1974		/* corresponding get_ldev in __drbd_set_state
1975		 * this may finally trigger drbd_ldev_destroy. */
1976		put_ldev(device);
1977	}
1978
1979	/* Notify peer that I had a local IO error, and did not detached.. */
1980	if (os.disk == D_UP_TO_DATE && ns.disk == D_INCONSISTENT && ns.conn >= C_CONNECTED)
1981		drbd_send_state(peer_device, ns);
1982
1983	/* Disks got bigger while they were detached */
1984	if (ns.disk > D_NEGOTIATING && ns.pdsk > D_NEGOTIATING &&
1985	    test_and_clear_bit(RESYNC_AFTER_NEG, &device->flags)) {
1986		if (ns.conn == C_CONNECTED)
1987			resync_after_online_grow(device);
1988	}
1989
1990	/* A resync finished or aborted, wake paused devices... */
1991	if ((os.conn > C_CONNECTED && ns.conn <= C_CONNECTED) ||
1992	    (os.peer_isp && !ns.peer_isp) ||
1993	    (os.user_isp && !ns.user_isp))
1994		resume_next_sg(device);
1995
1996	/* sync target done with resync.  Explicitly notify peer, even though
1997	 * it should (at least for non-empty resyncs) already know itself. */
1998	if (os.disk < D_UP_TO_DATE && os.conn >= C_SYNC_SOURCE && ns.conn == C_CONNECTED)
1999		drbd_send_state(peer_device, ns);
2000
2001	/* Verify finished, or reached stop sector.  Peer did not know about
2002	 * the stop sector, and we may even have changed the stop sector during
2003	 * verify to interrupt/stop early.  Send the new state. */
2004	if (os.conn == C_VERIFY_S && ns.conn == C_CONNECTED
2005	&& verify_can_do_stop_sector(device))
2006		drbd_send_state(peer_device, ns);
2007
2008	/* This triggers bitmap writeout of potentially still unwritten pages
2009	 * if the resync finished cleanly, or aborted because of peer disk
2010	 * failure, or on transition from resync back to AHEAD/BEHIND.
2011	 *
2012	 * Connection loss is handled in drbd_disconnected() by the receiver.
2013	 *
2014	 * For resync aborted because of local disk failure, we cannot do
2015	 * any bitmap writeout anymore.
2016	 *
2017	 * No harm done if some bits change during this phase.
2018	 */
2019	if ((os.conn > C_CONNECTED && os.conn < C_AHEAD) &&
2020	    (ns.conn == C_CONNECTED || ns.conn >= C_AHEAD) && get_ldev(device)) {
2021		drbd_queue_bitmap_io(device, &drbd_bm_write_copy_pages, NULL,
2022			"write from resync_finished", BM_LOCKED_CHANGE_ALLOWED,
2023			peer_device);
2024		put_ldev(device);
2025	}
2026
2027	if (ns.disk == D_DISKLESS &&
2028	    ns.conn == C_STANDALONE &&
2029	    ns.role == R_SECONDARY) {
2030		if (os.aftr_isp != ns.aftr_isp)
2031			resume_next_sg(device);
2032	}
2033
2034	drbd_md_sync(device);
2035}
2036
2037struct after_conn_state_chg_work {
2038	struct drbd_work w;
2039	enum drbd_conns oc;
2040	union drbd_state ns_min;
2041	union drbd_state ns_max; /* new, max state, over all devices */
2042	enum chg_state_flags flags;
2043	struct drbd_connection *connection;
2044	struct drbd_state_change *state_change;
2045};
2046
2047static int w_after_conn_state_ch(struct drbd_work *w, int unused)
2048{
2049	struct after_conn_state_chg_work *acscw =
2050		container_of(w, struct after_conn_state_chg_work, w);
2051	struct drbd_connection *connection = acscw->connection;
2052	enum drbd_conns oc = acscw->oc;
2053	union drbd_state ns_max = acscw->ns_max;
2054	struct drbd_peer_device *peer_device;
2055	int vnr;
2056
2057	broadcast_state_change(acscw->state_change);
2058	forget_state_change(acscw->state_change);
2059	kfree(acscw);
2060
2061	/* Upon network configuration, we need to start the receiver */
2062	if (oc == C_STANDALONE && ns_max.conn == C_UNCONNECTED)
2063		drbd_thread_start(&connection->receiver);
2064
2065	if (oc == C_DISCONNECTING && ns_max.conn == C_STANDALONE) {
2066		struct net_conf *old_conf;
2067
2068		mutex_lock(&notification_mutex);
2069		idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
2070			notify_peer_device_state(NULL, 0, peer_device, NULL,
2071						 NOTIFY_DESTROY | NOTIFY_CONTINUES);
2072		notify_connection_state(NULL, 0, connection, NULL, NOTIFY_DESTROY);
2073		mutex_unlock(&notification_mutex);
2074
2075		mutex_lock(&connection->resource->conf_update);
2076		old_conf = connection->net_conf;
2077		connection->my_addr_len = 0;
2078		connection->peer_addr_len = 0;
2079		RCU_INIT_POINTER(connection->net_conf, NULL);
2080		conn_free_crypto(connection);
2081		mutex_unlock(&connection->resource->conf_update);
2082
2083		kvfree_rcu_mightsleep(old_conf);
2084	}
2085
2086	if (ns_max.susp_fen) {
2087		/* case1: The outdate peer handler is successful: */
2088		if (ns_max.pdsk <= D_OUTDATED) {
2089			rcu_read_lock();
2090			idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2091				struct drbd_device *device = peer_device->device;
2092				if (test_bit(NEW_CUR_UUID, &device->flags)) {
2093					drbd_uuid_new_current(device);
2094					clear_bit(NEW_CUR_UUID, &device->flags);
2095				}
2096			}
2097			rcu_read_unlock();
2098			spin_lock_irq(&connection->resource->req_lock);
2099			_tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
2100			_conn_request_state(connection,
2101					    (union drbd_state) { { .susp_fen = 1 } },
2102					    (union drbd_state) { { .susp_fen = 0 } },
2103					    CS_VERBOSE);
2104			spin_unlock_irq(&connection->resource->req_lock);
2105		}
2106	}
2107	conn_md_sync(connection);
2108	kref_put(&connection->kref, drbd_destroy_connection);
2109
2110	return 0;
2111}
2112
2113static void conn_old_common_state(struct drbd_connection *connection, union drbd_state *pcs, enum chg_state_flags *pf)
2114{
2115	enum chg_state_flags flags = ~0;
2116	struct drbd_peer_device *peer_device;
2117	int vnr, first_vol = 1;
2118	union drbd_dev_state os, cs = {
2119		{ .role = R_SECONDARY,
2120		  .peer = R_UNKNOWN,
2121		  .conn = connection->cstate,
2122		  .disk = D_DISKLESS,
2123		  .pdsk = D_UNKNOWN,
2124		} };
2125
2126	rcu_read_lock();
2127	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2128		struct drbd_device *device = peer_device->device;
2129		os = device->state;
2130
2131		if (first_vol) {
2132			cs = os;
2133			first_vol = 0;
2134			continue;
2135		}
2136
2137		if (cs.role != os.role)
2138			flags &= ~CS_DC_ROLE;
2139
2140		if (cs.peer != os.peer)
2141			flags &= ~CS_DC_PEER;
2142
2143		if (cs.conn != os.conn)
2144			flags &= ~CS_DC_CONN;
2145
2146		if (cs.disk != os.disk)
2147			flags &= ~CS_DC_DISK;
2148
2149		if (cs.pdsk != os.pdsk)
2150			flags &= ~CS_DC_PDSK;
2151	}
2152	rcu_read_unlock();
2153
2154	*pf |= CS_DC_MASK;
2155	*pf &= flags;
2156	(*pcs).i = cs.i;
2157}
2158
2159static enum drbd_state_rv
2160conn_is_valid_transition(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2161			 enum chg_state_flags flags)
2162{
2163	enum drbd_state_rv rv = SS_SUCCESS;
2164	union drbd_state ns, os;
2165	struct drbd_peer_device *peer_device;
2166	int vnr;
2167
2168	rcu_read_lock();
2169	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2170		struct drbd_device *device = peer_device->device;
2171		os = drbd_read_state(device);
2172		ns = sanitize_state(device, os, apply_mask_val(os, mask, val), NULL);
2173
2174		if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
2175			ns.disk = os.disk;
2176
2177		if (ns.i == os.i)
2178			continue;
2179
2180		rv = is_valid_transition(os, ns);
2181
2182		if (rv >= SS_SUCCESS && !(flags & CS_HARD)) {
2183			rv = is_valid_state(device, ns);
2184			if (rv < SS_SUCCESS) {
2185				if (is_valid_state(device, os) == rv)
2186					rv = is_valid_soft_transition(os, ns, connection);
2187			} else
2188				rv = is_valid_soft_transition(os, ns, connection);
2189		}
2190
2191		if (rv < SS_SUCCESS) {
2192			if (flags & CS_VERBOSE)
2193				print_st_err(device, os, ns, rv);
2194			break;
2195		}
2196	}
2197	rcu_read_unlock();
2198
2199	return rv;
2200}
2201
2202static void
2203conn_set_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2204	       union drbd_state *pns_min, union drbd_state *pns_max, enum chg_state_flags flags)
2205{
2206	union drbd_state ns, os, ns_max = { };
2207	union drbd_state ns_min = {
2208		{ .role = R_MASK,
2209		  .peer = R_MASK,
2210		  .conn = val.conn,
2211		  .disk = D_MASK,
2212		  .pdsk = D_MASK
2213		} };
2214	struct drbd_peer_device *peer_device;
2215	enum drbd_state_rv rv;
2216	int vnr, number_of_volumes = 0;
2217
2218	if (mask.conn == C_MASK) {
2219		/* remember last connect time so request_timer_fn() won't
2220		 * kill newly established sessions while we are still trying to thaw
2221		 * previously frozen IO */
2222		if (connection->cstate != C_WF_REPORT_PARAMS && val.conn == C_WF_REPORT_PARAMS)
2223			connection->last_reconnect_jif = jiffies;
2224
2225		connection->cstate = val.conn;
2226	}
2227
2228	rcu_read_lock();
2229	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2230		struct drbd_device *device = peer_device->device;
2231		number_of_volumes++;
2232		os = drbd_read_state(device);
2233		ns = apply_mask_val(os, mask, val);
2234		ns = sanitize_state(device, os, ns, NULL);
2235
2236		if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
2237			ns.disk = os.disk;
2238
2239		rv = _drbd_set_state(device, ns, flags, NULL);
2240		BUG_ON(rv < SS_SUCCESS);
2241		ns.i = device->state.i;
2242		ns_max.role = max_role(ns.role, ns_max.role);
2243		ns_max.peer = max_role(ns.peer, ns_max.peer);
2244		ns_max.conn = max_t(enum drbd_conns, ns.conn, ns_max.conn);
2245		ns_max.disk = max_t(enum drbd_disk_state, ns.disk, ns_max.disk);
2246		ns_max.pdsk = max_t(enum drbd_disk_state, ns.pdsk, ns_max.pdsk);
2247
2248		ns_min.role = min_role(ns.role, ns_min.role);
2249		ns_min.peer = min_role(ns.peer, ns_min.peer);
2250		ns_min.conn = min_t(enum drbd_conns, ns.conn, ns_min.conn);
2251		ns_min.disk = min_t(enum drbd_disk_state, ns.disk, ns_min.disk);
2252		ns_min.pdsk = min_t(enum drbd_disk_state, ns.pdsk, ns_min.pdsk);
2253	}
2254	rcu_read_unlock();
2255
2256	if (number_of_volumes == 0) {
2257		ns_min = ns_max = (union drbd_state) { {
2258				.role = R_SECONDARY,
2259				.peer = R_UNKNOWN,
2260				.conn = val.conn,
2261				.disk = D_DISKLESS,
2262				.pdsk = D_UNKNOWN
2263			} };
2264	}
2265
2266	ns_min.susp = ns_max.susp = connection->resource->susp;
2267	ns_min.susp_nod = ns_max.susp_nod = connection->resource->susp_nod;
2268	ns_min.susp_fen = ns_max.susp_fen = connection->resource->susp_fen;
2269
2270	*pns_min = ns_min;
2271	*pns_max = ns_max;
2272}
2273
2274static enum drbd_state_rv
2275_conn_rq_cond(struct drbd_connection *connection, union drbd_state mask, union drbd_state val)
2276{
2277	enum drbd_state_rv err, rv = SS_UNKNOWN_ERROR; /* continue waiting */;
2278
2279	if (test_and_clear_bit(CONN_WD_ST_CHG_OKAY, &connection->flags))
2280		rv = SS_CW_SUCCESS;
2281
2282	if (test_and_clear_bit(CONN_WD_ST_CHG_FAIL, &connection->flags))
2283		rv = SS_CW_FAILED_BY_PEER;
2284
2285	err = conn_is_valid_transition(connection, mask, val, 0);
2286	if (err == SS_SUCCESS && connection->cstate == C_WF_REPORT_PARAMS)
2287		return rv;
2288
2289	return err;
2290}
2291
2292enum drbd_state_rv
2293_conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2294		    enum chg_state_flags flags)
2295{
2296	enum drbd_state_rv rv = SS_SUCCESS;
2297	struct after_conn_state_chg_work *acscw;
2298	enum drbd_conns oc = connection->cstate;
2299	union drbd_state ns_max, ns_min, os;
2300	bool have_mutex = false;
2301	struct drbd_state_change *state_change;
2302
2303	if (mask.conn) {
2304		rv = is_valid_conn_transition(oc, val.conn);
2305		if (rv < SS_SUCCESS)
2306			goto abort;
2307	}
2308
2309	rv = conn_is_valid_transition(connection, mask, val, flags);
2310	if (rv < SS_SUCCESS)
2311		goto abort;
2312
2313	if (oc == C_WF_REPORT_PARAMS && val.conn == C_DISCONNECTING &&
2314	    !(flags & (CS_LOCAL_ONLY | CS_HARD))) {
2315
2316		/* This will be a cluster-wide state change.
2317		 * Need to give up the spinlock, grab the mutex,
2318		 * then send the state change request, ... */
2319		spin_unlock_irq(&connection->resource->req_lock);
2320		mutex_lock(&connection->cstate_mutex);
2321		have_mutex = true;
2322
2323		set_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
2324		if (conn_send_state_req(connection, mask, val)) {
2325			/* sending failed. */
2326			clear_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
2327			rv = SS_CW_FAILED_BY_PEER;
2328			/* need to re-aquire the spin lock, though */
2329			goto abort_unlocked;
2330		}
2331
2332		if (val.conn == C_DISCONNECTING)
2333			set_bit(DISCONNECT_SENT, &connection->flags);
2334
2335		/* ... and re-aquire the spinlock.
2336		 * If _conn_rq_cond() returned >= SS_SUCCESS, we must call
2337		 * conn_set_state() within the same spinlock. */
2338		spin_lock_irq(&connection->resource->req_lock);
2339		wait_event_lock_irq(connection->ping_wait,
2340				(rv = _conn_rq_cond(connection, mask, val)),
2341				connection->resource->req_lock);
2342		clear_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
2343		if (rv < SS_SUCCESS)
2344			goto abort;
2345	}
2346
2347	state_change = remember_old_state(connection->resource, GFP_ATOMIC);
2348	conn_old_common_state(connection, &os, &flags);
2349	flags |= CS_DC_SUSP;
2350	conn_set_state(connection, mask, val, &ns_min, &ns_max, flags);
2351	conn_pr_state_change(connection, os, ns_max, flags);
2352	remember_new_state(state_change);
2353
2354	acscw = kmalloc(sizeof(*acscw), GFP_ATOMIC);
2355	if (acscw) {
2356		acscw->oc = os.conn;
2357		acscw->ns_min = ns_min;
2358		acscw->ns_max = ns_max;
2359		acscw->flags = flags;
2360		acscw->w.cb = w_after_conn_state_ch;
2361		kref_get(&connection->kref);
2362		acscw->connection = connection;
2363		acscw->state_change = state_change;
2364		drbd_queue_work(&connection->sender_work, &acscw->w);
2365	} else {
2366		drbd_err(connection, "Could not kmalloc an acscw\n");
2367	}
2368
2369 abort:
2370	if (have_mutex) {
2371		/* mutex_unlock() "... must not be used in interrupt context.",
2372		 * so give up the spinlock, then re-aquire it */
2373		spin_unlock_irq(&connection->resource->req_lock);
2374 abort_unlocked:
2375		mutex_unlock(&connection->cstate_mutex);
2376		spin_lock_irq(&connection->resource->req_lock);
2377	}
2378	if (rv < SS_SUCCESS && flags & CS_VERBOSE) {
2379		drbd_err(connection, "State change failed: %s\n", drbd_set_st_err_str(rv));
2380		drbd_err(connection, " mask = 0x%x val = 0x%x\n", mask.i, val.i);
2381		drbd_err(connection, " old_conn:%s wanted_conn:%s\n", drbd_conn_str(oc), drbd_conn_str(val.conn));
2382	}
2383	return rv;
2384}
2385
2386enum drbd_state_rv
2387conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2388		   enum chg_state_flags flags)
2389{
2390	enum drbd_state_rv rv;
2391
2392	spin_lock_irq(&connection->resource->req_lock);
2393	rv = _conn_request_state(connection, mask, val, flags);
2394	spin_unlock_irq(&connection->resource->req_lock);
2395
2396	return rv;
2397}
2398