cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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drbd_state.c (75098B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      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_device *device, enum drbd_conns cs)
   1226{
   1227	if (first_peer_device(device)->connection->agreed_pro_version < 90)
   1228		device->ov_start_sector = 0;
   1229	device->rs_total = drbd_bm_bits(device);
   1230	device->ov_position = 0;
   1231	if (cs == C_VERIFY_T) {
   1232		/* starting online verify from an arbitrary position
   1233		 * does not fit well into the existing protocol.
   1234		 * on C_VERIFY_T, we initialize ov_left and friends
   1235		 * implicitly in receive_DataRequest once the
   1236		 * first P_OV_REQUEST is received */
   1237		device->ov_start_sector = ~(sector_t)0;
   1238	} else {
   1239		unsigned long bit = BM_SECT_TO_BIT(device->ov_start_sector);
   1240		if (bit >= device->rs_total) {
   1241			device->ov_start_sector =
   1242				BM_BIT_TO_SECT(device->rs_total - 1);
   1243			device->rs_total = 1;
   1244		} else
   1245			device->rs_total -= bit;
   1246		device->ov_position = device->ov_start_sector;
   1247	}
   1248	device->ov_left = device->rs_total;
   1249}
   1250
   1251/**
   1252 * _drbd_set_state() - Set a new DRBD state
   1253 * @device:	DRBD device.
   1254 * @ns:		new state.
   1255 * @flags:	Flags
   1256 * @done:	Optional completion, that will get completed after the after_state_ch() finished
   1257 *
   1258 * Caller needs to hold req_lock. Do not call directly.
   1259 */
   1260enum drbd_state_rv
   1261_drbd_set_state(struct drbd_device *device, union drbd_state ns,
   1262	        enum chg_state_flags flags, struct completion *done)
   1263{
   1264	struct drbd_peer_device *peer_device = first_peer_device(device);
   1265	struct drbd_connection *connection = peer_device ? peer_device->connection : NULL;
   1266	union drbd_state os;
   1267	enum drbd_state_rv rv = SS_SUCCESS;
   1268	enum sanitize_state_warnings ssw;
   1269	struct after_state_chg_work *ascw;
   1270	struct drbd_state_change *state_change;
   1271
   1272	os = drbd_read_state(device);
   1273
   1274	ns = sanitize_state(device, os, ns, &ssw);
   1275	if (ns.i == os.i)
   1276		return SS_NOTHING_TO_DO;
   1277
   1278	rv = is_valid_transition(os, ns);
   1279	if (rv < SS_SUCCESS)
   1280		return rv;
   1281
   1282	if (!(flags & CS_HARD)) {
   1283		/*  pre-state-change checks ; only look at ns  */
   1284		/* See drbd_state_sw_errors in drbd_strings.c */
   1285
   1286		rv = is_valid_state(device, ns);
   1287		if (rv < SS_SUCCESS) {
   1288			/* If the old state was illegal as well, then let
   1289			   this happen...*/
   1290
   1291			if (is_valid_state(device, os) == rv)
   1292				rv = is_valid_soft_transition(os, ns, connection);
   1293		} else
   1294			rv = is_valid_soft_transition(os, ns, connection);
   1295	}
   1296
   1297	if (rv < SS_SUCCESS) {
   1298		if (flags & CS_VERBOSE)
   1299			print_st_err(device, os, ns, rv);
   1300		return rv;
   1301	}
   1302
   1303	print_sanitize_warnings(device, ssw);
   1304
   1305	drbd_pr_state_change(device, os, ns, flags);
   1306
   1307	/* Display changes to the susp* flags that where caused by the call to
   1308	   sanitize_state(). Only display it here if we where not called from
   1309	   _conn_request_state() */
   1310	if (!(flags & CS_DC_SUSP))
   1311		conn_pr_state_change(connection, os, ns,
   1312				     (flags & ~CS_DC_MASK) | CS_DC_SUSP);
   1313
   1314	/* if we are going -> D_FAILED or D_DISKLESS, grab one extra reference
   1315	 * on the ldev here, to be sure the transition -> D_DISKLESS resp.
   1316	 * drbd_ldev_destroy() won't happen before our corresponding
   1317	 * after_state_ch works run, where we put_ldev again. */
   1318	if ((os.disk != D_FAILED && ns.disk == D_FAILED) ||
   1319	    (os.disk != D_DISKLESS && ns.disk == D_DISKLESS))
   1320		atomic_inc(&device->local_cnt);
   1321
   1322	if (!is_sync_state(os.conn) && is_sync_state(ns.conn))
   1323		clear_bit(RS_DONE, &device->flags);
   1324
   1325	/* FIXME: Have any flags been set earlier in this function already? */
   1326	state_change = remember_old_state(device->resource, GFP_ATOMIC);
   1327
   1328	/* changes to local_cnt and device flags should be visible before
   1329	 * changes to state, which again should be visible before anything else
   1330	 * depending on that change happens. */
   1331	smp_wmb();
   1332	device->state.i = ns.i;
   1333	device->resource->susp = ns.susp;
   1334	device->resource->susp_nod = ns.susp_nod;
   1335	device->resource->susp_fen = ns.susp_fen;
   1336	smp_wmb();
   1337
   1338	remember_new_state(state_change);
   1339
   1340	/* put replicated vs not-replicated requests in seperate epochs */
   1341	if (drbd_should_do_remote((union drbd_dev_state)os.i) !=
   1342	    drbd_should_do_remote((union drbd_dev_state)ns.i))
   1343		start_new_tl_epoch(connection);
   1344
   1345	if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
   1346		drbd_print_uuids(device, "attached to UUIDs");
   1347
   1348	/* Wake up role changes, that were delayed because of connection establishing */
   1349	if (os.conn == C_WF_REPORT_PARAMS && ns.conn != C_WF_REPORT_PARAMS &&
   1350	    no_peer_wf_report_params(connection)) {
   1351		clear_bit(STATE_SENT, &connection->flags);
   1352		wake_up_all_devices(connection);
   1353	}
   1354
   1355	wake_up(&device->misc_wait);
   1356	wake_up(&device->state_wait);
   1357	wake_up(&connection->ping_wait);
   1358
   1359	/* Aborted verify run, or we reached the stop sector.
   1360	 * Log the last position, unless end-of-device. */
   1361	if ((os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) &&
   1362	    ns.conn <= C_CONNECTED) {
   1363		device->ov_start_sector =
   1364			BM_BIT_TO_SECT(drbd_bm_bits(device) - device->ov_left);
   1365		if (device->ov_left)
   1366			drbd_info(device, "Online Verify reached sector %llu\n",
   1367				(unsigned long long)device->ov_start_sector);
   1368	}
   1369
   1370	if ((os.conn == C_PAUSED_SYNC_T || os.conn == C_PAUSED_SYNC_S) &&
   1371	    (ns.conn == C_SYNC_TARGET  || ns.conn == C_SYNC_SOURCE)) {
   1372		drbd_info(device, "Syncer continues.\n");
   1373		device->rs_paused += (long)jiffies
   1374				  -(long)device->rs_mark_time[device->rs_last_mark];
   1375		if (ns.conn == C_SYNC_TARGET)
   1376			mod_timer(&device->resync_timer, jiffies);
   1377	}
   1378
   1379	if ((os.conn == C_SYNC_TARGET  || os.conn == C_SYNC_SOURCE) &&
   1380	    (ns.conn == C_PAUSED_SYNC_T || ns.conn == C_PAUSED_SYNC_S)) {
   1381		drbd_info(device, "Resync suspended\n");
   1382		device->rs_mark_time[device->rs_last_mark] = jiffies;
   1383	}
   1384
   1385	if (os.conn == C_CONNECTED &&
   1386	    (ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T)) {
   1387		unsigned long now = jiffies;
   1388		int i;
   1389
   1390		set_ov_position(device, ns.conn);
   1391		device->rs_start = now;
   1392		device->rs_last_sect_ev = 0;
   1393		device->ov_last_oos_size = 0;
   1394		device->ov_last_oos_start = 0;
   1395
   1396		for (i = 0; i < DRBD_SYNC_MARKS; i++) {
   1397			device->rs_mark_left[i] = device->ov_left;
   1398			device->rs_mark_time[i] = now;
   1399		}
   1400
   1401		drbd_rs_controller_reset(device);
   1402
   1403		if (ns.conn == C_VERIFY_S) {
   1404			drbd_info(device, "Starting Online Verify from sector %llu\n",
   1405					(unsigned long long)device->ov_position);
   1406			mod_timer(&device->resync_timer, jiffies);
   1407		}
   1408	}
   1409
   1410	if (get_ldev(device)) {
   1411		u32 mdf = device->ldev->md.flags & ~(MDF_CONSISTENT|MDF_PRIMARY_IND|
   1412						 MDF_CONNECTED_IND|MDF_WAS_UP_TO_DATE|
   1413						 MDF_PEER_OUT_DATED|MDF_CRASHED_PRIMARY);
   1414
   1415		mdf &= ~MDF_AL_CLEAN;
   1416		if (test_bit(CRASHED_PRIMARY, &device->flags))
   1417			mdf |= MDF_CRASHED_PRIMARY;
   1418		if (device->state.role == R_PRIMARY ||
   1419		    (device->state.pdsk < D_INCONSISTENT && device->state.peer == R_PRIMARY))
   1420			mdf |= MDF_PRIMARY_IND;
   1421		if (device->state.conn > C_WF_REPORT_PARAMS)
   1422			mdf |= MDF_CONNECTED_IND;
   1423		if (device->state.disk > D_INCONSISTENT)
   1424			mdf |= MDF_CONSISTENT;
   1425		if (device->state.disk > D_OUTDATED)
   1426			mdf |= MDF_WAS_UP_TO_DATE;
   1427		if (device->state.pdsk <= D_OUTDATED && device->state.pdsk >= D_INCONSISTENT)
   1428			mdf |= MDF_PEER_OUT_DATED;
   1429		if (mdf != device->ldev->md.flags) {
   1430			device->ldev->md.flags = mdf;
   1431			drbd_md_mark_dirty(device);
   1432		}
   1433		if (os.disk < D_CONSISTENT && ns.disk >= D_CONSISTENT)
   1434			drbd_set_ed_uuid(device, device->ldev->md.uuid[UI_CURRENT]);
   1435		put_ldev(device);
   1436	}
   1437
   1438	/* Peer was forced D_UP_TO_DATE & R_PRIMARY, consider to resync */
   1439	if (os.disk == D_INCONSISTENT && os.pdsk == D_INCONSISTENT &&
   1440	    os.peer == R_SECONDARY && ns.peer == R_PRIMARY)
   1441		set_bit(CONSIDER_RESYNC, &device->flags);
   1442
   1443	/* Receiver should clean up itself */
   1444	if (os.conn != C_DISCONNECTING && ns.conn == C_DISCONNECTING)
   1445		drbd_thread_stop_nowait(&connection->receiver);
   1446
   1447	/* Now the receiver finished cleaning up itself, it should die */
   1448	if (os.conn != C_STANDALONE && ns.conn == C_STANDALONE)
   1449		drbd_thread_stop_nowait(&connection->receiver);
   1450
   1451	/* Upon network failure, we need to restart the receiver. */
   1452	if (os.conn > C_WF_CONNECTION &&
   1453	    ns.conn <= C_TEAR_DOWN && ns.conn >= C_TIMEOUT)
   1454		drbd_thread_restart_nowait(&connection->receiver);
   1455
   1456	/* Resume AL writing if we get a connection */
   1457	if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED) {
   1458		drbd_resume_al(device);
   1459		connection->connect_cnt++;
   1460	}
   1461
   1462	/* remember last attach time so request_timer_fn() won't
   1463	 * kill newly established sessions while we are still trying to thaw
   1464	 * previously frozen IO */
   1465	if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
   1466	    ns.disk > D_NEGOTIATING)
   1467		device->last_reattach_jif = jiffies;
   1468
   1469	ascw = kmalloc(sizeof(*ascw), GFP_ATOMIC);
   1470	if (ascw) {
   1471		ascw->os = os;
   1472		ascw->ns = ns;
   1473		ascw->flags = flags;
   1474		ascw->w.cb = w_after_state_ch;
   1475		ascw->device = device;
   1476		ascw->done = done;
   1477		ascw->state_change = state_change;
   1478		drbd_queue_work(&connection->sender_work,
   1479				&ascw->w);
   1480	} else {
   1481		drbd_err(device, "Could not kmalloc an ascw\n");
   1482	}
   1483
   1484	return rv;
   1485}
   1486
   1487static int w_after_state_ch(struct drbd_work *w, int unused)
   1488{
   1489	struct after_state_chg_work *ascw =
   1490		container_of(w, struct after_state_chg_work, w);
   1491	struct drbd_device *device = ascw->device;
   1492
   1493	after_state_ch(device, ascw->os, ascw->ns, ascw->flags, ascw->state_change);
   1494	forget_state_change(ascw->state_change);
   1495	if (ascw->flags & CS_WAIT_COMPLETE)
   1496		complete(ascw->done);
   1497	kfree(ascw);
   1498
   1499	return 0;
   1500}
   1501
   1502static void abw_start_sync(struct drbd_device *device, int rv)
   1503{
   1504	if (rv) {
   1505		drbd_err(device, "Writing the bitmap failed not starting resync.\n");
   1506		_drbd_request_state(device, NS(conn, C_CONNECTED), CS_VERBOSE);
   1507		return;
   1508	}
   1509
   1510	switch (device->state.conn) {
   1511	case C_STARTING_SYNC_T:
   1512		_drbd_request_state(device, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
   1513		break;
   1514	case C_STARTING_SYNC_S:
   1515		drbd_start_resync(device, C_SYNC_SOURCE);
   1516		break;
   1517	}
   1518}
   1519
   1520int drbd_bitmap_io_from_worker(struct drbd_device *device,
   1521		int (*io_fn)(struct drbd_device *),
   1522		char *why, enum bm_flag flags)
   1523{
   1524	int rv;
   1525
   1526	D_ASSERT(device, current == first_peer_device(device)->connection->worker.task);
   1527
   1528	/* open coded non-blocking drbd_suspend_io(device); */
   1529	atomic_inc(&device->suspend_cnt);
   1530
   1531	drbd_bm_lock(device, why, flags);
   1532	rv = io_fn(device);
   1533	drbd_bm_unlock(device);
   1534
   1535	drbd_resume_io(device);
   1536
   1537	return rv;
   1538}
   1539
   1540int notify_resource_state_change(struct sk_buff *skb,
   1541				  unsigned int seq,
   1542				  struct drbd_resource_state_change *resource_state_change,
   1543				  enum drbd_notification_type type)
   1544{
   1545	struct drbd_resource *resource = resource_state_change->resource;
   1546	struct resource_info resource_info = {
   1547		.res_role = resource_state_change->role[NEW],
   1548		.res_susp = resource_state_change->susp[NEW],
   1549		.res_susp_nod = resource_state_change->susp_nod[NEW],
   1550		.res_susp_fen = resource_state_change->susp_fen[NEW],
   1551	};
   1552
   1553	return notify_resource_state(skb, seq, resource, &resource_info, type);
   1554}
   1555
   1556int notify_connection_state_change(struct sk_buff *skb,
   1557				    unsigned int seq,
   1558				    struct drbd_connection_state_change *connection_state_change,
   1559				    enum drbd_notification_type type)
   1560{
   1561	struct drbd_connection *connection = connection_state_change->connection;
   1562	struct connection_info connection_info = {
   1563		.conn_connection_state = connection_state_change->cstate[NEW],
   1564		.conn_role = connection_state_change->peer_role[NEW],
   1565	};
   1566
   1567	return notify_connection_state(skb, seq, connection, &connection_info, type);
   1568}
   1569
   1570int notify_device_state_change(struct sk_buff *skb,
   1571				unsigned int seq,
   1572				struct drbd_device_state_change *device_state_change,
   1573				enum drbd_notification_type type)
   1574{
   1575	struct drbd_device *device = device_state_change->device;
   1576	struct device_info device_info = {
   1577		.dev_disk_state = device_state_change->disk_state[NEW],
   1578	};
   1579
   1580	return notify_device_state(skb, seq, device, &device_info, type);
   1581}
   1582
   1583int notify_peer_device_state_change(struct sk_buff *skb,
   1584				     unsigned int seq,
   1585				     struct drbd_peer_device_state_change *p,
   1586				     enum drbd_notification_type type)
   1587{
   1588	struct drbd_peer_device *peer_device = p->peer_device;
   1589	struct peer_device_info peer_device_info = {
   1590		.peer_repl_state = p->repl_state[NEW],
   1591		.peer_disk_state = p->disk_state[NEW],
   1592		.peer_resync_susp_user = p->resync_susp_user[NEW],
   1593		.peer_resync_susp_peer = p->resync_susp_peer[NEW],
   1594		.peer_resync_susp_dependency = p->resync_susp_dependency[NEW],
   1595	};
   1596
   1597	return notify_peer_device_state(skb, seq, peer_device, &peer_device_info, type);
   1598}
   1599
   1600static void broadcast_state_change(struct drbd_state_change *state_change)
   1601{
   1602	struct drbd_resource_state_change *resource_state_change = &state_change->resource[0];
   1603	bool resource_state_has_changed;
   1604	unsigned int n_device, n_connection, n_peer_device, n_peer_devices;
   1605	int (*last_func)(struct sk_buff *, unsigned int, void *,
   1606			  enum drbd_notification_type) = NULL;
   1607	void *last_arg = NULL;
   1608
   1609#define HAS_CHANGED(state) ((state)[OLD] != (state)[NEW])
   1610#define FINAL_STATE_CHANGE(type) \
   1611	({ if (last_func) \
   1612		last_func(NULL, 0, last_arg, type); \
   1613	})
   1614#define REMEMBER_STATE_CHANGE(func, arg, type) \
   1615	({ FINAL_STATE_CHANGE(type | NOTIFY_CONTINUES); \
   1616	   last_func = (typeof(last_func))func; \
   1617	   last_arg = arg; \
   1618	 })
   1619
   1620	mutex_lock(&notification_mutex);
   1621
   1622	resource_state_has_changed =
   1623	    HAS_CHANGED(resource_state_change->role) ||
   1624	    HAS_CHANGED(resource_state_change->susp) ||
   1625	    HAS_CHANGED(resource_state_change->susp_nod) ||
   1626	    HAS_CHANGED(resource_state_change->susp_fen);
   1627
   1628	if (resource_state_has_changed)
   1629		REMEMBER_STATE_CHANGE(notify_resource_state_change,
   1630				      resource_state_change, NOTIFY_CHANGE);
   1631
   1632	for (n_connection = 0; n_connection < state_change->n_connections; n_connection++) {
   1633		struct drbd_connection_state_change *connection_state_change =
   1634				&state_change->connections[n_connection];
   1635
   1636		if (HAS_CHANGED(connection_state_change->peer_role) ||
   1637		    HAS_CHANGED(connection_state_change->cstate))
   1638			REMEMBER_STATE_CHANGE(notify_connection_state_change,
   1639					      connection_state_change, NOTIFY_CHANGE);
   1640	}
   1641
   1642	for (n_device = 0; n_device < state_change->n_devices; n_device++) {
   1643		struct drbd_device_state_change *device_state_change =
   1644			&state_change->devices[n_device];
   1645
   1646		if (HAS_CHANGED(device_state_change->disk_state))
   1647			REMEMBER_STATE_CHANGE(notify_device_state_change,
   1648					      device_state_change, NOTIFY_CHANGE);
   1649	}
   1650
   1651	n_peer_devices = state_change->n_devices * state_change->n_connections;
   1652	for (n_peer_device = 0; n_peer_device < n_peer_devices; n_peer_device++) {
   1653		struct drbd_peer_device_state_change *p =
   1654			&state_change->peer_devices[n_peer_device];
   1655
   1656		if (HAS_CHANGED(p->disk_state) ||
   1657		    HAS_CHANGED(p->repl_state) ||
   1658		    HAS_CHANGED(p->resync_susp_user) ||
   1659		    HAS_CHANGED(p->resync_susp_peer) ||
   1660		    HAS_CHANGED(p->resync_susp_dependency))
   1661			REMEMBER_STATE_CHANGE(notify_peer_device_state_change,
   1662					      p, NOTIFY_CHANGE);
   1663	}
   1664
   1665	FINAL_STATE_CHANGE(NOTIFY_CHANGE);
   1666	mutex_unlock(&notification_mutex);
   1667
   1668#undef HAS_CHANGED
   1669#undef FINAL_STATE_CHANGE
   1670#undef REMEMBER_STATE_CHANGE
   1671}
   1672
   1673/* takes old and new peer disk state */
   1674static bool lost_contact_to_peer_data(enum drbd_disk_state os, enum drbd_disk_state ns)
   1675{
   1676	if ((os >= D_INCONSISTENT && os != D_UNKNOWN && os != D_OUTDATED)
   1677	&&  (ns < D_INCONSISTENT || ns == D_UNKNOWN || ns == D_OUTDATED))
   1678		return true;
   1679
   1680	/* Scenario, starting with normal operation
   1681	 * Connected Primary/Secondary UpToDate/UpToDate
   1682	 * NetworkFailure Primary/Unknown UpToDate/DUnknown (frozen)
   1683	 * ...
   1684	 * Connected Primary/Secondary UpToDate/Diskless (resumed; needs to bump uuid!)
   1685	 */
   1686	if (os == D_UNKNOWN
   1687	&&  (ns == D_DISKLESS || ns == D_FAILED || ns == D_OUTDATED))
   1688		return true;
   1689
   1690	return false;
   1691}
   1692
   1693/**
   1694 * after_state_ch() - Perform after state change actions that may sleep
   1695 * @device:	DRBD device.
   1696 * @os:		old state.
   1697 * @ns:		new state.
   1698 * @flags:	Flags
   1699 * @state_change: state change to broadcast
   1700 */
   1701static void after_state_ch(struct drbd_device *device, union drbd_state os,
   1702			   union drbd_state ns, enum chg_state_flags flags,
   1703			   struct drbd_state_change *state_change)
   1704{
   1705	struct drbd_resource *resource = device->resource;
   1706	struct drbd_peer_device *peer_device = first_peer_device(device);
   1707	struct drbd_connection *connection = peer_device ? peer_device->connection : NULL;
   1708	struct sib_info sib;
   1709
   1710	broadcast_state_change(state_change);
   1711
   1712	sib.sib_reason = SIB_STATE_CHANGE;
   1713	sib.os = os;
   1714	sib.ns = ns;
   1715
   1716	if ((os.disk != D_UP_TO_DATE || os.pdsk != D_UP_TO_DATE)
   1717	&&  (ns.disk == D_UP_TO_DATE && ns.pdsk == D_UP_TO_DATE)) {
   1718		clear_bit(CRASHED_PRIMARY, &device->flags);
   1719		if (device->p_uuid)
   1720			device->p_uuid[UI_FLAGS] &= ~((u64)2);
   1721	}
   1722
   1723	/* Inform userspace about the change... */
   1724	drbd_bcast_event(device, &sib);
   1725
   1726	if (!(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE) &&
   1727	    (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE))
   1728		drbd_khelper(device, "pri-on-incon-degr");
   1729
   1730	/* Here we have the actions that are performed after a
   1731	   state change. This function might sleep */
   1732
   1733	if (ns.susp_nod) {
   1734		enum drbd_req_event what = NOTHING;
   1735
   1736		spin_lock_irq(&device->resource->req_lock);
   1737		if (os.conn < C_CONNECTED && conn_lowest_conn(connection) >= C_CONNECTED)
   1738			what = RESEND;
   1739
   1740		if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
   1741		    conn_lowest_disk(connection) == D_UP_TO_DATE)
   1742			what = RESTART_FROZEN_DISK_IO;
   1743
   1744		if (resource->susp_nod && what != NOTHING) {
   1745			_tl_restart(connection, what);
   1746			_conn_request_state(connection,
   1747					    (union drbd_state) { { .susp_nod = 1 } },
   1748					    (union drbd_state) { { .susp_nod = 0 } },
   1749					    CS_VERBOSE);
   1750		}
   1751		spin_unlock_irq(&device->resource->req_lock);
   1752	}
   1753
   1754	if (ns.susp_fen) {
   1755		spin_lock_irq(&device->resource->req_lock);
   1756		if (resource->susp_fen && conn_lowest_conn(connection) >= C_CONNECTED) {
   1757			/* case2: The connection was established again: */
   1758			struct drbd_peer_device *peer_device;
   1759			int vnr;
   1760
   1761			rcu_read_lock();
   1762			idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
   1763				clear_bit(NEW_CUR_UUID, &peer_device->device->flags);
   1764			rcu_read_unlock();
   1765
   1766			/* We should actively create a new uuid, _before_
   1767			 * we resume/resent, if the peer is diskless
   1768			 * (recovery from a multiple error scenario).
   1769			 * Currently, this happens with a slight delay
   1770			 * below when checking lost_contact_to_peer_data() ...
   1771			 */
   1772			_tl_restart(connection, RESEND);
   1773			_conn_request_state(connection,
   1774					    (union drbd_state) { { .susp_fen = 1 } },
   1775					    (union drbd_state) { { .susp_fen = 0 } },
   1776					    CS_VERBOSE);
   1777		}
   1778		spin_unlock_irq(&device->resource->req_lock);
   1779	}
   1780
   1781	/* Became sync source.  With protocol >= 96, we still need to send out
   1782	 * the sync uuid now. Need to do that before any drbd_send_state, or
   1783	 * the other side may go "paused sync" before receiving the sync uuids,
   1784	 * which is unexpected. */
   1785	if ((os.conn != C_SYNC_SOURCE && os.conn != C_PAUSED_SYNC_S) &&
   1786	    (ns.conn == C_SYNC_SOURCE || ns.conn == C_PAUSED_SYNC_S) &&
   1787	    connection->agreed_pro_version >= 96 && get_ldev(device)) {
   1788		drbd_gen_and_send_sync_uuid(peer_device);
   1789		put_ldev(device);
   1790	}
   1791
   1792	/* Do not change the order of the if above and the two below... */
   1793	if (os.pdsk == D_DISKLESS &&
   1794	    ns.pdsk > D_DISKLESS && ns.pdsk != D_UNKNOWN) {      /* attach on the peer */
   1795		/* we probably will start a resync soon.
   1796		 * make sure those things are properly reset. */
   1797		device->rs_total = 0;
   1798		device->rs_failed = 0;
   1799		atomic_set(&device->rs_pending_cnt, 0);
   1800		drbd_rs_cancel_all(device);
   1801
   1802		drbd_send_uuids(peer_device);
   1803		drbd_send_state(peer_device, ns);
   1804	}
   1805	/* No point in queuing send_bitmap if we don't have a connection
   1806	 * anymore, so check also the _current_ state, not only the new state
   1807	 * at the time this work was queued. */
   1808	if (os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S &&
   1809	    device->state.conn == C_WF_BITMAP_S)
   1810		drbd_queue_bitmap_io(device, &drbd_send_bitmap, NULL,
   1811				"send_bitmap (WFBitMapS)",
   1812				BM_LOCKED_TEST_ALLOWED);
   1813
   1814	/* Lost contact to peer's copy of the data */
   1815	if (lost_contact_to_peer_data(os.pdsk, ns.pdsk)) {
   1816		if (get_ldev(device)) {
   1817			if ((ns.role == R_PRIMARY || ns.peer == R_PRIMARY) &&
   1818			    device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
   1819				if (drbd_suspended(device)) {
   1820					set_bit(NEW_CUR_UUID, &device->flags);
   1821				} else {
   1822					drbd_uuid_new_current(device);
   1823					drbd_send_uuids(peer_device);
   1824				}
   1825			}
   1826			put_ldev(device);
   1827		}
   1828	}
   1829
   1830	if (ns.pdsk < D_INCONSISTENT && get_ldev(device)) {
   1831		if (os.peer != R_PRIMARY && ns.peer == R_PRIMARY &&
   1832		    device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
   1833			drbd_uuid_new_current(device);
   1834			drbd_send_uuids(peer_device);
   1835		}
   1836		/* D_DISKLESS Peer becomes secondary */
   1837		if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY)
   1838			/* We may still be Primary ourselves.
   1839			 * No harm done if the bitmap still changes,
   1840			 * redirtied pages will follow later. */
   1841			drbd_bitmap_io_from_worker(device, &drbd_bm_write,
   1842				"demote diskless peer", BM_LOCKED_SET_ALLOWED);
   1843		put_ldev(device);
   1844	}
   1845
   1846	/* Write out all changed bits on demote.
   1847	 * Though, no need to da that just yet
   1848	 * if there is a resync going on still */
   1849	if (os.role == R_PRIMARY && ns.role == R_SECONDARY &&
   1850		device->state.conn <= C_CONNECTED && get_ldev(device)) {
   1851		/* No changes to the bitmap expected this time, so assert that,
   1852		 * even though no harm was done if it did change. */
   1853		drbd_bitmap_io_from_worker(device, &drbd_bm_write,
   1854				"demote", BM_LOCKED_TEST_ALLOWED);
   1855		put_ldev(device);
   1856	}
   1857
   1858	/* Last part of the attaching process ... */
   1859	if (ns.conn >= C_CONNECTED &&
   1860	    os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) {
   1861		drbd_send_sizes(peer_device, 0, 0);  /* to start sync... */
   1862		drbd_send_uuids(peer_device);
   1863		drbd_send_state(peer_device, ns);
   1864	}
   1865
   1866	/* We want to pause/continue resync, tell peer. */
   1867	if (ns.conn >= C_CONNECTED &&
   1868	     ((os.aftr_isp != ns.aftr_isp) ||
   1869	      (os.user_isp != ns.user_isp)))
   1870		drbd_send_state(peer_device, ns);
   1871
   1872	/* In case one of the isp bits got set, suspend other devices. */
   1873	if ((!os.aftr_isp && !os.peer_isp && !os.user_isp) &&
   1874	    (ns.aftr_isp || ns.peer_isp || ns.user_isp))
   1875		suspend_other_sg(device);
   1876
   1877	/* Make sure the peer gets informed about eventual state
   1878	   changes (ISP bits) while we were in WFReportParams. */
   1879	if (os.conn == C_WF_REPORT_PARAMS && ns.conn >= C_CONNECTED)
   1880		drbd_send_state(peer_device, ns);
   1881
   1882	if (os.conn != C_AHEAD && ns.conn == C_AHEAD)
   1883		drbd_send_state(peer_device, ns);
   1884
   1885	/* We are in the progress to start a full sync... */
   1886	if ((os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
   1887	    (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S))
   1888		/* no other bitmap changes expected during this phase */
   1889		drbd_queue_bitmap_io(device,
   1890			&drbd_bmio_set_n_write, &abw_start_sync,
   1891			"set_n_write from StartingSync", BM_LOCKED_TEST_ALLOWED);
   1892
   1893	/* first half of local IO error, failure to attach,
   1894	 * or administrative detach */
   1895	if (os.disk != D_FAILED && ns.disk == D_FAILED) {
   1896		enum drbd_io_error_p eh = EP_PASS_ON;
   1897		int was_io_error = 0;
   1898		/* corresponding get_ldev was in _drbd_set_state, to serialize
   1899		 * our cleanup here with the transition to D_DISKLESS.
   1900		 * But is is still not save to dreference ldev here, since
   1901		 * we might come from an failed Attach before ldev was set. */
   1902		if (device->ldev) {
   1903			rcu_read_lock();
   1904			eh = rcu_dereference(device->ldev->disk_conf)->on_io_error;
   1905			rcu_read_unlock();
   1906
   1907			was_io_error = test_and_clear_bit(WAS_IO_ERROR, &device->flags);
   1908
   1909			/* Intentionally call this handler first, before drbd_send_state().
   1910			 * See: 2932204 drbd: call local-io-error handler early
   1911			 * People may chose to hard-reset the box from this handler.
   1912			 * It is useful if this looks like a "regular node crash". */
   1913			if (was_io_error && eh == EP_CALL_HELPER)
   1914				drbd_khelper(device, "local-io-error");
   1915
   1916			/* Immediately allow completion of all application IO,
   1917			 * that waits for completion from the local disk,
   1918			 * if this was a force-detach due to disk_timeout
   1919			 * or administrator request (drbdsetup detach --force).
   1920			 * Do NOT abort otherwise.
   1921			 * Aborting local requests may cause serious problems,
   1922			 * if requests are completed to upper layers already,
   1923			 * and then later the already submitted local bio completes.
   1924			 * This can cause DMA into former bio pages that meanwhile
   1925			 * have been re-used for other things.
   1926			 * So aborting local requests may cause crashes,
   1927			 * or even worse, silent data corruption.
   1928			 */
   1929			if (test_and_clear_bit(FORCE_DETACH, &device->flags))
   1930				tl_abort_disk_io(device);
   1931
   1932			/* current state still has to be D_FAILED,
   1933			 * there is only one way out: to D_DISKLESS,
   1934			 * and that may only happen after our put_ldev below. */
   1935			if (device->state.disk != D_FAILED)
   1936				drbd_err(device,
   1937					"ASSERT FAILED: disk is %s during detach\n",
   1938					drbd_disk_str(device->state.disk));
   1939
   1940			if (ns.conn >= C_CONNECTED)
   1941				drbd_send_state(peer_device, ns);
   1942
   1943			drbd_rs_cancel_all(device);
   1944
   1945			/* In case we want to get something to stable storage still,
   1946			 * this may be the last chance.
   1947			 * Following put_ldev may transition to D_DISKLESS. */
   1948			drbd_md_sync(device);
   1949		}
   1950		put_ldev(device);
   1951	}
   1952
   1953	/* second half of local IO error, failure to attach,
   1954	 * or administrative detach,
   1955	 * after local_cnt references have reached zero again */
   1956	if (os.disk != D_DISKLESS && ns.disk == D_DISKLESS) {
   1957		/* We must still be diskless,
   1958		 * re-attach has to be serialized with this! */
   1959		if (device->state.disk != D_DISKLESS)
   1960			drbd_err(device,
   1961				 "ASSERT FAILED: disk is %s while going diskless\n",
   1962				 drbd_disk_str(device->state.disk));
   1963
   1964		if (ns.conn >= C_CONNECTED)
   1965			drbd_send_state(peer_device, ns);
   1966		/* corresponding get_ldev in __drbd_set_state
   1967		 * this may finally trigger drbd_ldev_destroy. */
   1968		put_ldev(device);
   1969	}
   1970
   1971	/* Notify peer that I had a local IO error, and did not detached.. */
   1972	if (os.disk == D_UP_TO_DATE && ns.disk == D_INCONSISTENT && ns.conn >= C_CONNECTED)
   1973		drbd_send_state(peer_device, ns);
   1974
   1975	/* Disks got bigger while they were detached */
   1976	if (ns.disk > D_NEGOTIATING && ns.pdsk > D_NEGOTIATING &&
   1977	    test_and_clear_bit(RESYNC_AFTER_NEG, &device->flags)) {
   1978		if (ns.conn == C_CONNECTED)
   1979			resync_after_online_grow(device);
   1980	}
   1981
   1982	/* A resync finished or aborted, wake paused devices... */
   1983	if ((os.conn > C_CONNECTED && ns.conn <= C_CONNECTED) ||
   1984	    (os.peer_isp && !ns.peer_isp) ||
   1985	    (os.user_isp && !ns.user_isp))
   1986		resume_next_sg(device);
   1987
   1988	/* sync target done with resync.  Explicitly notify peer, even though
   1989	 * it should (at least for non-empty resyncs) already know itself. */
   1990	if (os.disk < D_UP_TO_DATE && os.conn >= C_SYNC_SOURCE && ns.conn == C_CONNECTED)
   1991		drbd_send_state(peer_device, ns);
   1992
   1993	/* Verify finished, or reached stop sector.  Peer did not know about
   1994	 * the stop sector, and we may even have changed the stop sector during
   1995	 * verify to interrupt/stop early.  Send the new state. */
   1996	if (os.conn == C_VERIFY_S && ns.conn == C_CONNECTED
   1997	&& verify_can_do_stop_sector(device))
   1998		drbd_send_state(peer_device, ns);
   1999
   2000	/* This triggers bitmap writeout of potentially still unwritten pages
   2001	 * if the resync finished cleanly, or aborted because of peer disk
   2002	 * failure, or on transition from resync back to AHEAD/BEHIND.
   2003	 *
   2004	 * Connection loss is handled in drbd_disconnected() by the receiver.
   2005	 *
   2006	 * For resync aborted because of local disk failure, we cannot do
   2007	 * any bitmap writeout anymore.
   2008	 *
   2009	 * No harm done if some bits change during this phase.
   2010	 */
   2011	if ((os.conn > C_CONNECTED && os.conn < C_AHEAD) &&
   2012	    (ns.conn == C_CONNECTED || ns.conn >= C_AHEAD) && get_ldev(device)) {
   2013		drbd_queue_bitmap_io(device, &drbd_bm_write_copy_pages, NULL,
   2014			"write from resync_finished", BM_LOCKED_CHANGE_ALLOWED);
   2015		put_ldev(device);
   2016	}
   2017
   2018	if (ns.disk == D_DISKLESS &&
   2019	    ns.conn == C_STANDALONE &&
   2020	    ns.role == R_SECONDARY) {
   2021		if (os.aftr_isp != ns.aftr_isp)
   2022			resume_next_sg(device);
   2023	}
   2024
   2025	drbd_md_sync(device);
   2026}
   2027
   2028struct after_conn_state_chg_work {
   2029	struct drbd_work w;
   2030	enum drbd_conns oc;
   2031	union drbd_state ns_min;
   2032	union drbd_state ns_max; /* new, max state, over all devices */
   2033	enum chg_state_flags flags;
   2034	struct drbd_connection *connection;
   2035	struct drbd_state_change *state_change;
   2036};
   2037
   2038static int w_after_conn_state_ch(struct drbd_work *w, int unused)
   2039{
   2040	struct after_conn_state_chg_work *acscw =
   2041		container_of(w, struct after_conn_state_chg_work, w);
   2042	struct drbd_connection *connection = acscw->connection;
   2043	enum drbd_conns oc = acscw->oc;
   2044	union drbd_state ns_max = acscw->ns_max;
   2045	struct drbd_peer_device *peer_device;
   2046	int vnr;
   2047
   2048	broadcast_state_change(acscw->state_change);
   2049	forget_state_change(acscw->state_change);
   2050	kfree(acscw);
   2051
   2052	/* Upon network configuration, we need to start the receiver */
   2053	if (oc == C_STANDALONE && ns_max.conn == C_UNCONNECTED)
   2054		drbd_thread_start(&connection->receiver);
   2055
   2056	if (oc == C_DISCONNECTING && ns_max.conn == C_STANDALONE) {
   2057		struct net_conf *old_conf;
   2058
   2059		mutex_lock(&notification_mutex);
   2060		idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
   2061			notify_peer_device_state(NULL, 0, peer_device, NULL,
   2062						 NOTIFY_DESTROY | NOTIFY_CONTINUES);
   2063		notify_connection_state(NULL, 0, connection, NULL, NOTIFY_DESTROY);
   2064		mutex_unlock(&notification_mutex);
   2065
   2066		mutex_lock(&connection->resource->conf_update);
   2067		old_conf = connection->net_conf;
   2068		connection->my_addr_len = 0;
   2069		connection->peer_addr_len = 0;
   2070		RCU_INIT_POINTER(connection->net_conf, NULL);
   2071		conn_free_crypto(connection);
   2072		mutex_unlock(&connection->resource->conf_update);
   2073
   2074		kvfree_rcu(old_conf);
   2075	}
   2076
   2077	if (ns_max.susp_fen) {
   2078		/* case1: The outdate peer handler is successful: */
   2079		if (ns_max.pdsk <= D_OUTDATED) {
   2080			rcu_read_lock();
   2081			idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
   2082				struct drbd_device *device = peer_device->device;
   2083				if (test_bit(NEW_CUR_UUID, &device->flags)) {
   2084					drbd_uuid_new_current(device);
   2085					clear_bit(NEW_CUR_UUID, &device->flags);
   2086				}
   2087			}
   2088			rcu_read_unlock();
   2089			spin_lock_irq(&connection->resource->req_lock);
   2090			_tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
   2091			_conn_request_state(connection,
   2092					    (union drbd_state) { { .susp_fen = 1 } },
   2093					    (union drbd_state) { { .susp_fen = 0 } },
   2094					    CS_VERBOSE);
   2095			spin_unlock_irq(&connection->resource->req_lock);
   2096		}
   2097	}
   2098	conn_md_sync(connection);
   2099	kref_put(&connection->kref, drbd_destroy_connection);
   2100
   2101	return 0;
   2102}
   2103
   2104static void conn_old_common_state(struct drbd_connection *connection, union drbd_state *pcs, enum chg_state_flags *pf)
   2105{
   2106	enum chg_state_flags flags = ~0;
   2107	struct drbd_peer_device *peer_device;
   2108	int vnr, first_vol = 1;
   2109	union drbd_dev_state os, cs = {
   2110		{ .role = R_SECONDARY,
   2111		  .peer = R_UNKNOWN,
   2112		  .conn = connection->cstate,
   2113		  .disk = D_DISKLESS,
   2114		  .pdsk = D_UNKNOWN,
   2115		} };
   2116
   2117	rcu_read_lock();
   2118	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
   2119		struct drbd_device *device = peer_device->device;
   2120		os = device->state;
   2121
   2122		if (first_vol) {
   2123			cs = os;
   2124			first_vol = 0;
   2125			continue;
   2126		}
   2127
   2128		if (cs.role != os.role)
   2129			flags &= ~CS_DC_ROLE;
   2130
   2131		if (cs.peer != os.peer)
   2132			flags &= ~CS_DC_PEER;
   2133
   2134		if (cs.conn != os.conn)
   2135			flags &= ~CS_DC_CONN;
   2136
   2137		if (cs.disk != os.disk)
   2138			flags &= ~CS_DC_DISK;
   2139
   2140		if (cs.pdsk != os.pdsk)
   2141			flags &= ~CS_DC_PDSK;
   2142	}
   2143	rcu_read_unlock();
   2144
   2145	*pf |= CS_DC_MASK;
   2146	*pf &= flags;
   2147	(*pcs).i = cs.i;
   2148}
   2149
   2150static enum drbd_state_rv
   2151conn_is_valid_transition(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
   2152			 enum chg_state_flags flags)
   2153{
   2154	enum drbd_state_rv rv = SS_SUCCESS;
   2155	union drbd_state ns, os;
   2156	struct drbd_peer_device *peer_device;
   2157	int vnr;
   2158
   2159	rcu_read_lock();
   2160	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
   2161		struct drbd_device *device = peer_device->device;
   2162		os = drbd_read_state(device);
   2163		ns = sanitize_state(device, os, apply_mask_val(os, mask, val), NULL);
   2164
   2165		if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
   2166			ns.disk = os.disk;
   2167
   2168		if (ns.i == os.i)
   2169			continue;
   2170
   2171		rv = is_valid_transition(os, ns);
   2172
   2173		if (rv >= SS_SUCCESS && !(flags & CS_HARD)) {
   2174			rv = is_valid_state(device, ns);
   2175			if (rv < SS_SUCCESS) {
   2176				if (is_valid_state(device, os) == rv)
   2177					rv = is_valid_soft_transition(os, ns, connection);
   2178			} else
   2179				rv = is_valid_soft_transition(os, ns, connection);
   2180		}
   2181
   2182		if (rv < SS_SUCCESS) {
   2183			if (flags & CS_VERBOSE)
   2184				print_st_err(device, os, ns, rv);
   2185			break;
   2186		}
   2187	}
   2188	rcu_read_unlock();
   2189
   2190	return rv;
   2191}
   2192
   2193static void
   2194conn_set_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
   2195	       union drbd_state *pns_min, union drbd_state *pns_max, enum chg_state_flags flags)
   2196{
   2197	union drbd_state ns, os, ns_max = { };
   2198	union drbd_state ns_min = {
   2199		{ .role = R_MASK,
   2200		  .peer = R_MASK,
   2201		  .conn = val.conn,
   2202		  .disk = D_MASK,
   2203		  .pdsk = D_MASK
   2204		} };
   2205	struct drbd_peer_device *peer_device;
   2206	enum drbd_state_rv rv;
   2207	int vnr, number_of_volumes = 0;
   2208
   2209	if (mask.conn == C_MASK) {
   2210		/* remember last connect time so request_timer_fn() won't
   2211		 * kill newly established sessions while we are still trying to thaw
   2212		 * previously frozen IO */
   2213		if (connection->cstate != C_WF_REPORT_PARAMS && val.conn == C_WF_REPORT_PARAMS)
   2214			connection->last_reconnect_jif = jiffies;
   2215
   2216		connection->cstate = val.conn;
   2217	}
   2218
   2219	rcu_read_lock();
   2220	idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
   2221		struct drbd_device *device = peer_device->device;
   2222		number_of_volumes++;
   2223		os = drbd_read_state(device);
   2224		ns = apply_mask_val(os, mask, val);
   2225		ns = sanitize_state(device, os, ns, NULL);
   2226
   2227		if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
   2228			ns.disk = os.disk;
   2229
   2230		rv = _drbd_set_state(device, ns, flags, NULL);
   2231		BUG_ON(rv < SS_SUCCESS);
   2232		ns.i = device->state.i;
   2233		ns_max.role = max_role(ns.role, ns_max.role);
   2234		ns_max.peer = max_role(ns.peer, ns_max.peer);
   2235		ns_max.conn = max_t(enum drbd_conns, ns.conn, ns_max.conn);
   2236		ns_max.disk = max_t(enum drbd_disk_state, ns.disk, ns_max.disk);
   2237		ns_max.pdsk = max_t(enum drbd_disk_state, ns.pdsk, ns_max.pdsk);
   2238
   2239		ns_min.role = min_role(ns.role, ns_min.role);
   2240		ns_min.peer = min_role(ns.peer, ns_min.peer);
   2241		ns_min.conn = min_t(enum drbd_conns, ns.conn, ns_min.conn);
   2242		ns_min.disk = min_t(enum drbd_disk_state, ns.disk, ns_min.disk);
   2243		ns_min.pdsk = min_t(enum drbd_disk_state, ns.pdsk, ns_min.pdsk);
   2244	}
   2245	rcu_read_unlock();
   2246
   2247	if (number_of_volumes == 0) {
   2248		ns_min = ns_max = (union drbd_state) { {
   2249				.role = R_SECONDARY,
   2250				.peer = R_UNKNOWN,
   2251				.conn = val.conn,
   2252				.disk = D_DISKLESS,
   2253				.pdsk = D_UNKNOWN
   2254			} };
   2255	}
   2256
   2257	ns_min.susp = ns_max.susp = connection->resource->susp;
   2258	ns_min.susp_nod = ns_max.susp_nod = connection->resource->susp_nod;
   2259	ns_min.susp_fen = ns_max.susp_fen = connection->resource->susp_fen;
   2260
   2261	*pns_min = ns_min;
   2262	*pns_max = ns_max;
   2263}
   2264
   2265static enum drbd_state_rv
   2266_conn_rq_cond(struct drbd_connection *connection, union drbd_state mask, union drbd_state val)
   2267{
   2268	enum drbd_state_rv err, rv = SS_UNKNOWN_ERROR; /* continue waiting */;
   2269
   2270	if (test_and_clear_bit(CONN_WD_ST_CHG_OKAY, &connection->flags))
   2271		rv = SS_CW_SUCCESS;
   2272
   2273	if (test_and_clear_bit(CONN_WD_ST_CHG_FAIL, &connection->flags))
   2274		rv = SS_CW_FAILED_BY_PEER;
   2275
   2276	err = conn_is_valid_transition(connection, mask, val, 0);
   2277	if (err == SS_SUCCESS && connection->cstate == C_WF_REPORT_PARAMS)
   2278		return rv;
   2279
   2280	return err;
   2281}
   2282
   2283enum drbd_state_rv
   2284_conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
   2285		    enum chg_state_flags flags)
   2286{
   2287	enum drbd_state_rv rv = SS_SUCCESS;
   2288	struct after_conn_state_chg_work *acscw;
   2289	enum drbd_conns oc = connection->cstate;
   2290	union drbd_state ns_max, ns_min, os;
   2291	bool have_mutex = false;
   2292	struct drbd_state_change *state_change;
   2293
   2294	if (mask.conn) {
   2295		rv = is_valid_conn_transition(oc, val.conn);
   2296		if (rv < SS_SUCCESS)
   2297			goto abort;
   2298	}
   2299
   2300	rv = conn_is_valid_transition(connection, mask, val, flags);
   2301	if (rv < SS_SUCCESS)
   2302		goto abort;
   2303
   2304	if (oc == C_WF_REPORT_PARAMS && val.conn == C_DISCONNECTING &&
   2305	    !(flags & (CS_LOCAL_ONLY | CS_HARD))) {
   2306
   2307		/* This will be a cluster-wide state change.
   2308		 * Need to give up the spinlock, grab the mutex,
   2309		 * then send the state change request, ... */
   2310		spin_unlock_irq(&connection->resource->req_lock);
   2311		mutex_lock(&connection->cstate_mutex);
   2312		have_mutex = true;
   2313
   2314		set_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
   2315		if (conn_send_state_req(connection, mask, val)) {
   2316			/* sending failed. */
   2317			clear_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
   2318			rv = SS_CW_FAILED_BY_PEER;
   2319			/* need to re-aquire the spin lock, though */
   2320			goto abort_unlocked;
   2321		}
   2322
   2323		if (val.conn == C_DISCONNECTING)
   2324			set_bit(DISCONNECT_SENT, &connection->flags);
   2325
   2326		/* ... and re-aquire the spinlock.
   2327		 * If _conn_rq_cond() returned >= SS_SUCCESS, we must call
   2328		 * conn_set_state() within the same spinlock. */
   2329		spin_lock_irq(&connection->resource->req_lock);
   2330		wait_event_lock_irq(connection->ping_wait,
   2331				(rv = _conn_rq_cond(connection, mask, val)),
   2332				connection->resource->req_lock);
   2333		clear_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
   2334		if (rv < SS_SUCCESS)
   2335			goto abort;
   2336	}
   2337
   2338	state_change = remember_old_state(connection->resource, GFP_ATOMIC);
   2339	conn_old_common_state(connection, &os, &flags);
   2340	flags |= CS_DC_SUSP;
   2341	conn_set_state(connection, mask, val, &ns_min, &ns_max, flags);
   2342	conn_pr_state_change(connection, os, ns_max, flags);
   2343	remember_new_state(state_change);
   2344
   2345	acscw = kmalloc(sizeof(*acscw), GFP_ATOMIC);
   2346	if (acscw) {
   2347		acscw->oc = os.conn;
   2348		acscw->ns_min = ns_min;
   2349		acscw->ns_max = ns_max;
   2350		acscw->flags = flags;
   2351		acscw->w.cb = w_after_conn_state_ch;
   2352		kref_get(&connection->kref);
   2353		acscw->connection = connection;
   2354		acscw->state_change = state_change;
   2355		drbd_queue_work(&connection->sender_work, &acscw->w);
   2356	} else {
   2357		drbd_err(connection, "Could not kmalloc an acscw\n");
   2358	}
   2359
   2360 abort:
   2361	if (have_mutex) {
   2362		/* mutex_unlock() "... must not be used in interrupt context.",
   2363		 * so give up the spinlock, then re-aquire it */
   2364		spin_unlock_irq(&connection->resource->req_lock);
   2365 abort_unlocked:
   2366		mutex_unlock(&connection->cstate_mutex);
   2367		spin_lock_irq(&connection->resource->req_lock);
   2368	}
   2369	if (rv < SS_SUCCESS && flags & CS_VERBOSE) {
   2370		drbd_err(connection, "State change failed: %s\n", drbd_set_st_err_str(rv));
   2371		drbd_err(connection, " mask = 0x%x val = 0x%x\n", mask.i, val.i);
   2372		drbd_err(connection, " old_conn:%s wanted_conn:%s\n", drbd_conn_str(oc), drbd_conn_str(val.conn));
   2373	}
   2374	return rv;
   2375}
   2376
   2377enum drbd_state_rv
   2378conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
   2379		   enum chg_state_flags flags)
   2380{
   2381	enum drbd_state_rv rv;
   2382
   2383	spin_lock_irq(&connection->resource->req_lock);
   2384	rv = _conn_request_state(connection, mask, val, flags);
   2385	spin_unlock_irq(&connection->resource->req_lock);
   2386
   2387	return rv;
   2388}