drivers/block/drbd/drbd_state.c

   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
  22 struct 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
  32 enum 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
  41 static 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
  58 static 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
  83 struct 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
 155 static 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
 211 void 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
 254 void 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
 279 static int w_after_state_ch(struct drbd_work *w, int unused);
 280 static 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 *);
 283 static enum drbd_state_rv is_valid_state(struct drbd_device *, union drbd_state);
 284 static enum drbd_state_rv is_valid_soft_transition(union drbd_state, union drbd_state, struct drbd_connection *);
 285 static enum drbd_state_rv is_valid_transition(union drbd_state os, union drbd_state ns);
 286 static union drbd_state sanitize_state(struct drbd_device *device, union drbd_state os,
 287                                        union drbd_state ns, enum sanitize_state_warnings *warn);
 288
 289 static inline bool is_susp(union drbd_state s)
 290 {
 291         return s.susp || s.susp_nod || s.susp_fen;
 292 }
 293
 294 bool 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. */
 317 static 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
 326 static 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
 335 enum 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
 351 enum 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
 367 enum 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
 383 enum 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
 399 enum 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
 415 enum 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
 431 static 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
 448 static 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  */
 467 static 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
 480 static union drbd_state
 481 apply_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
 488 enum drbd_state_rv
 489 drbd_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  */
 510 void 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
 516 static 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  */
 562 static enum drbd_state_rv
 563 drbd_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
 629 abort:
 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  */
 648 enum 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  */
 672 static enum drbd_state_rv
 673 request_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
 679 int 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
 699 enum 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
 715 static 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
 733 void 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
 743 static 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
 774 static 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
 799 static 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  */
 822 static enum drbd_state_rv
 823 is_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
 897 out:
 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  */
 911 static enum drbd_state_rv
 912 is_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
 973 static enum drbd_state_rv
 974 is_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  */
1013 static enum drbd_state_rv
1014 is_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
1027 static 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  */
1052 static 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
1218 void 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 */
1225 static 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  */
1262 enum 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
1489 static 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
1504 static 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
1522 int 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
1543 int notify_resource_state_change(struct sk_buff *skb,
1544                                   unsigned int seq,
1545                                   struct drbd_resource_state_change *resource_state_change,
1546                                   enum drbd_notification_type type)
1547 {
1548         struct drbd_resource *resource = resource_state_change->resource;
1549         struct resource_info resource_info = {
1550                 .res_role = resource_state_change->role[NEW],
1551                 .res_susp = resource_state_change->susp[NEW],
1552                 .res_susp_nod = resource_state_change->susp_nod[NEW],
1553                 .res_susp_fen = resource_state_change->susp_fen[NEW],
1554         };
1555
1556         return notify_resource_state(skb, seq, resource, &resource_info, type);
1557 }
1558
1559 int notify_connection_state_change(struct sk_buff *skb,
1560                                     unsigned int seq,
1561                                     struct drbd_connection_state_change *connection_state_change,
1562                                     enum drbd_notification_type type)
1563 {
1564         struct drbd_connection *connection = connection_state_change->connection;
1565         struct connection_info connection_info = {
1566                 .conn_connection_state = connection_state_change->cstate[NEW],
1567                 .conn_role = connection_state_change->peer_role[NEW],
1568         };
1569
1570         return notify_connection_state(skb, seq, connection, &connection_info, type);
1571 }
1572
1573 int notify_device_state_change(struct sk_buff *skb,
1574                                 unsigned int seq,
1575                                 struct drbd_device_state_change *device_state_change,
1576                                 enum drbd_notification_type type)
1577 {
1578         struct drbd_device *device = device_state_change->device;
1579         struct device_info device_info = {
1580                 .dev_disk_state = device_state_change->disk_state[NEW],
1581         };
1582
1583         return notify_device_state(skb, seq, device, &device_info, type);
1584 }
1585
1586 int notify_peer_device_state_change(struct sk_buff *skb,
1587                                      unsigned int seq,
1588                                      struct drbd_peer_device_state_change *p,
1589                                      enum drbd_notification_type type)
1590 {
1591         struct drbd_peer_device *peer_device = p->peer_device;
1592         struct peer_device_info peer_device_info = {
1593                 .peer_repl_state = p->repl_state[NEW],
1594                 .peer_disk_state = p->disk_state[NEW],
1595                 .peer_resync_susp_user = p->resync_susp_user[NEW],
1596                 .peer_resync_susp_peer = p->resync_susp_peer[NEW],
1597                 .peer_resync_susp_dependency = p->resync_susp_dependency[NEW],
1598         };
1599
1600         return notify_peer_device_state(skb, seq, peer_device, &peer_device_info, type);
1601 }
1602
1603 static void broadcast_state_change(struct drbd_state_change *state_change)
1604 {
1605         struct drbd_resource_state_change *resource_state_change = &state_change->resource[0];
1606         bool resource_state_has_changed;
1607         unsigned int n_device, n_connection, n_peer_device, n_peer_devices;
1608         int (*last_func)(struct sk_buff *, unsigned int, void *,
1609                           enum drbd_notification_type) = NULL;
1610         void *last_arg = NULL;
1611
1612 #define HAS_CHANGED(state) ((state)[OLD] != (state)[NEW])
1613 #define FINAL_STATE_CHANGE(type) \
1614         ({ if (last_func) \
1615                 last_func(NULL, 0, last_arg, type); \
1616         })
1617 #define REMEMBER_STATE_CHANGE(func, arg, type) \
1618         ({ FINAL_STATE_CHANGE(type | NOTIFY_CONTINUES); \
1619            last_func = (typeof(last_func))func; \
1620            last_arg = arg; \
1621          })
1622
1623         mutex_lock(&notification_mutex);
1624
1625         resource_state_has_changed =
1626             HAS_CHANGED(resource_state_change->role) ||
1627             HAS_CHANGED(resource_state_change->susp) ||
1628             HAS_CHANGED(resource_state_change->susp_nod) ||
1629             HAS_CHANGED(resource_state_change->susp_fen);
1630
1631         if (resource_state_has_changed)
1632                 REMEMBER_STATE_CHANGE(notify_resource_state_change,
1633                                       resource_state_change, NOTIFY_CHANGE);
1634
1635         for (n_connection = 0; n_connection < state_change->n_connections; n_connection++) {
1636                 struct drbd_connection_state_change *connection_state_change =
1637                                 &state_change->connections[n_connection];
1638
1639                 if (HAS_CHANGED(connection_state_change->peer_role) ||
1640                     HAS_CHANGED(connection_state_change->cstate))
1641                         REMEMBER_STATE_CHANGE(notify_connection_state_change,
1642                                               connection_state_change, NOTIFY_CHANGE);
1643         }
1644
1645         for (n_device = 0; n_device < state_change->n_devices; n_device++) {
1646                 struct drbd_device_state_change *device_state_change =
1647                         &state_change->devices[n_device];
1648
1649                 if (HAS_CHANGED(device_state_change->disk_state))
1650                         REMEMBER_STATE_CHANGE(notify_device_state_change,
1651                                               device_state_change, NOTIFY_CHANGE);
1652         }
1653
1654         n_peer_devices = state_change->n_devices * state_change->n_connections;
1655         for (n_peer_device = 0; n_peer_device < n_peer_devices; n_peer_device++) {
1656                 struct drbd_peer_device_state_change *p =
1657                         &state_change->peer_devices[n_peer_device];
1658
1659                 if (HAS_CHANGED(p->disk_state) ||
1660                     HAS_CHANGED(p->repl_state) ||
1661                     HAS_CHANGED(p->resync_susp_user) ||
1662                     HAS_CHANGED(p->resync_susp_peer) ||
1663                     HAS_CHANGED(p->resync_susp_dependency))
1664                         REMEMBER_STATE_CHANGE(notify_peer_device_state_change,
1665                                               p, NOTIFY_CHANGE);
1666         }
1667
1668         FINAL_STATE_CHANGE(NOTIFY_CHANGE);
1669         mutex_unlock(&notification_mutex);
1670
1671 #undef HAS_CHANGED
1672 #undef FINAL_STATE_CHANGE
1673 #undef REMEMBER_STATE_CHANGE
1674 }
1675
1676 /* takes old and new peer disk state */
1677 static bool lost_contact_to_peer_data(enum drbd_disk_state os, enum drbd_disk_state ns)
1678 {
1679         if ((os >= D_INCONSISTENT && os != D_UNKNOWN && os != D_OUTDATED)
1680         &&  (ns < D_INCONSISTENT || ns == D_UNKNOWN || ns == D_OUTDATED))
1681                 return true;
1682
1683         /* Scenario, starting with normal operation
1684          * Connected Primary/Secondary UpToDate/UpToDate
1685          * NetworkFailure Primary/Unknown UpToDate/DUnknown (frozen)
1686          * ...
1687          * Connected Primary/Secondary UpToDate/Diskless (resumed; needs to bump uuid!)
1688          */
1689         if (os == D_UNKNOWN
1690         &&  (ns == D_DISKLESS || ns == D_FAILED || ns == D_OUTDATED))
1691                 return true;
1692
1693         return false;
1694 }
1695
1696 /**
1697  * after_state_ch() - Perform after state change actions that may sleep
1698  * @device:     DRBD device.
1699  * @os:         old state.
1700  * @ns:         new state.
1701  * @flags:      Flags
1702  * @state_change: state change to broadcast
1703  */
1704 static void after_state_ch(struct drbd_device *device, union drbd_state os,
1705                            union drbd_state ns, enum chg_state_flags flags,
1706                            struct drbd_state_change *state_change)
1707 {
1708         struct drbd_resource *resource = device->resource;
1709         struct drbd_peer_device *peer_device = first_peer_device(device);
1710         struct drbd_connection *connection = peer_device ? peer_device->connection : NULL;
1711         struct sib_info sib;
1712
1713         broadcast_state_change(state_change);
1714
1715         sib.sib_reason = SIB_STATE_CHANGE;
1716         sib.os = os;
1717         sib.ns = ns;
1718
1719         if ((os.disk != D_UP_TO_DATE || os.pdsk != D_UP_TO_DATE)
1720         &&  (ns.disk == D_UP_TO_DATE && ns.pdsk == D_UP_TO_DATE)) {
1721                 clear_bit(CRASHED_PRIMARY, &device->flags);
1722                 if (device->p_uuid)
1723                         device->p_uuid[UI_FLAGS] &= ~((u64)2);
1724         }
1725
1726         /* Inform userspace about the change... */
1727         drbd_bcast_event(device, &sib);
1728
1729         if (!(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE) &&
1730             (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE))
1731                 drbd_khelper(device, "pri-on-incon-degr");
1732
1733         /* Here we have the actions that are performed after a
1734            state change. This function might sleep */
1735
1736         if (ns.susp_nod) {
1737                 enum drbd_req_event what = NOTHING;
1738
1739                 spin_lock_irq(&device->resource->req_lock);
1740                 if (os.conn < C_CONNECTED && conn_lowest_conn(connection) >= C_CONNECTED)
1741                         what = RESEND;
1742
1743                 if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
1744                     conn_lowest_disk(connection) == D_UP_TO_DATE)
1745                         what = RESTART_FROZEN_DISK_IO;
1746
1747                 if (resource->susp_nod && what != NOTHING) {
1748                         _tl_restart(connection, what);
1749                         _conn_request_state(connection,
1750                                             (union drbd_state) { { .susp_nod = 1 } },
1751                                             (union drbd_state) { { .susp_nod = 0 } },
1752                                             CS_VERBOSE);
1753                 }
1754                 spin_unlock_irq(&device->resource->req_lock);
1755         }
1756
1757         if (ns.susp_fen) {
1758                 spin_lock_irq(&device->resource->req_lock);
1759                 if (resource->susp_fen && conn_lowest_conn(connection) >= C_CONNECTED) {
1760                         /* case2: The connection was established again: */
1761                         struct drbd_peer_device *peer_device;
1762                         int vnr;
1763
1764                         rcu_read_lock();
1765                         idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
1766                                 clear_bit(NEW_CUR_UUID, &peer_device->device->flags);
1767                         rcu_read_unlock();
1768
1769                         /* We should actively create a new uuid, _before_
1770                          * we resume/resent, if the peer is diskless
1771                          * (recovery from a multiple error scenario).
1772                          * Currently, this happens with a slight delay
1773                          * below when checking lost_contact_to_peer_data() ...
1774                          */
1775                         _tl_restart(connection, RESEND);
1776                         _conn_request_state(connection,
1777                                             (union drbd_state) { { .susp_fen = 1 } },
1778                                             (union drbd_state) { { .susp_fen = 0 } },
1779                                             CS_VERBOSE);
1780                 }
1781                 spin_unlock_irq(&device->resource->req_lock);
1782         }
1783
1784         /* Became sync source.  With protocol >= 96, we still need to send out
1785          * the sync uuid now. Need to do that before any drbd_send_state, or
1786          * the other side may go "paused sync" before receiving the sync uuids,
1787          * which is unexpected. */
1788         if ((os.conn != C_SYNC_SOURCE && os.conn != C_PAUSED_SYNC_S) &&
1789             (ns.conn == C_SYNC_SOURCE || ns.conn == C_PAUSED_SYNC_S) &&
1790             connection->agreed_pro_version >= 96 && get_ldev(device)) {
1791                 drbd_gen_and_send_sync_uuid(peer_device);
1792                 put_ldev(device);
1793         }
1794
1795         /* Do not change the order of the if above and the two below... */
1796         if (os.pdsk == D_DISKLESS &&
1797             ns.pdsk > D_DISKLESS && ns.pdsk != D_UNKNOWN) {      /* attach on the peer */
1798                 /* we probably will start a resync soon.
1799                  * make sure those things are properly reset. */
1800                 device->rs_total = 0;
1801                 device->rs_failed = 0;
1802                 atomic_set(&device->rs_pending_cnt, 0);
1803                 drbd_rs_cancel_all(device);
1804
1805                 drbd_send_uuids(peer_device);
1806                 drbd_send_state(peer_device, ns);
1807         }
1808         /* No point in queuing send_bitmap if we don't have a connection
1809          * anymore, so check also the _current_ state, not only the new state
1810          * at the time this work was queued. */
1811         if (os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S &&
1812             device->state.conn == C_WF_BITMAP_S)
1813                 drbd_queue_bitmap_io(device, &drbd_send_bitmap, NULL,
1814                                 "send_bitmap (WFBitMapS)",
1815                                 BM_LOCKED_TEST_ALLOWED, peer_device);
1816
1817         /* Lost contact to peer's copy of the data */
1818         if (lost_contact_to_peer_data(os.pdsk, ns.pdsk)) {
1819                 if (get_ldev(device)) {
1820                         if ((ns.role == R_PRIMARY || ns.peer == R_PRIMARY) &&
1821                             device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
1822                                 if (drbd_suspended(device)) {
1823                                         set_bit(NEW_CUR_UUID, &device->flags);
1824                                 } else {
1825                                         drbd_uuid_new_current(device);
1826                                         drbd_send_uuids(peer_device);
1827                                 }
1828                         }
1829                         put_ldev(device);
1830                 }
1831         }
1832
1833         if (ns.pdsk < D_INCONSISTENT && get_ldev(device)) {
1834                 if (os.peer != R_PRIMARY && ns.peer == R_PRIMARY &&
1835                     device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
1836                         drbd_uuid_new_current(device);
1837                         drbd_send_uuids(peer_device);
1838                 }
1839                 /* D_DISKLESS Peer becomes secondary */
1840                 if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY)
1841                         /* We may still be Primary ourselves.
1842                          * No harm done if the bitmap still changes,
1843                          * redirtied pages will follow later. */
1844                         drbd_bitmap_io_from_worker(device, &drbd_bm_write,
1845                                 "demote diskless peer", BM_LOCKED_SET_ALLOWED, peer_device);
1846                 put_ldev(device);
1847         }
1848
1849         /* Write out all changed bits on demote.
1850          * Though, no need to da that just yet
1851          * if there is a resync going on still */
1852         if (os.role == R_PRIMARY && ns.role == R_SECONDARY &&
1853                 device->state.conn <= C_CONNECTED && get_ldev(device)) {
1854                 /* No changes to the bitmap expected this time, so assert that,
1855                  * even though no harm was done if it did change. */
1856                 drbd_bitmap_io_from_worker(device, &drbd_bm_write,
1857                                 "demote", BM_LOCKED_TEST_ALLOWED, peer_device);
1858                 put_ldev(device);
1859         }
1860
1861         /* Last part of the attaching process ... */
1862         if (ns.conn >= C_CONNECTED &&
1863             os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) {
1864                 drbd_send_sizes(peer_device, 0, 0);  /* to start sync... */
1865                 drbd_send_uuids(peer_device);
1866                 drbd_send_state(peer_device, ns);
1867         }
1868
1869         /* We want to pause/continue resync, tell peer. */
1870         if (ns.conn >= C_CONNECTED &&
1871              ((os.aftr_isp != ns.aftr_isp) ||
1872               (os.user_isp != ns.user_isp)))
1873                 drbd_send_state(peer_device, ns);
1874
1875         /* In case one of the isp bits got set, suspend other devices. */
1876         if ((!os.aftr_isp && !os.peer_isp && !os.user_isp) &&
1877             (ns.aftr_isp || ns.peer_isp || ns.user_isp))
1878                 suspend_other_sg(device);
1879
1880         /* Make sure the peer gets informed about eventual state
1881            changes (ISP bits) while we were in WFReportParams. */
1882         if (os.conn == C_WF_REPORT_PARAMS && ns.conn >= C_CONNECTED)
1883                 drbd_send_state(peer_device, ns);
1884
1885         if (os.conn != C_AHEAD && ns.conn == C_AHEAD)
1886                 drbd_send_state(peer_device, ns);
1887
1888         /* We are in the progress to start a full sync... */
1889         if ((os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
1890             (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S))
1891                 /* no other bitmap changes expected during this phase */
1892                 drbd_queue_bitmap_io(device,
1893                         &drbd_bmio_set_n_write, &abw_start_sync,
1894                         "set_n_write from StartingSync", BM_LOCKED_TEST_ALLOWED,
1895                         peer_device);
1896
1897         /* first half of local IO error, failure to attach,
1898          * or administrative detach */
1899         if (os.disk != D_FAILED && ns.disk == D_FAILED) {
1900                 enum drbd_io_error_p eh = EP_PASS_ON;
1901                 int was_io_error = 0;
1902                 /* corresponding get_ldev was in _drbd_set_state, to serialize
1903                  * our cleanup here with the transition to D_DISKLESS.
1904                  * But is is still not save to dreference ldev here, since
1905                  * we might come from an failed Attach before ldev was set. */
1906                 if (device->ldev) {
1907                         rcu_read_lock();
1908                         eh = rcu_dereference(device->ldev->disk_conf)->on_io_error;
1909                         rcu_read_unlock();
1910
1911                         was_io_error = test_and_clear_bit(WAS_IO_ERROR, &device->flags);
1912
1913                         /* Intentionally call this handler first, before drbd_send_state().
1914                          * See: 2932204 drbd: call local-io-error handler early
1915                          * People may chose to hard-reset the box from this handler.
1916                          * It is useful if this looks like a "regular node crash". */
1917                         if (was_io_error && eh == EP_CALL_HELPER)
1918                                 drbd_khelper(device, "local-io-error");
1919
1920                         /* Immediately allow completion of all application IO,
1921                          * that waits for completion from the local disk,
1922                          * if this was a force-detach due to disk_timeout
1923                          * or administrator request (drbdsetup detach --force).
1924                          * Do NOT abort otherwise.
1925                          * Aborting local requests may cause serious problems,
1926                          * if requests are completed to upper layers already,
1927                          * and then later the already submitted local bio completes.
1928                          * This can cause DMA into former bio pages that meanwhile
1929                          * have been re-used for other things.
1930                          * So aborting local requests may cause crashes,
1931                          * or even worse, silent data corruption.
1932                          */
1933                         if (test_and_clear_bit(FORCE_DETACH, &device->flags))
1934                                 tl_abort_disk_io(device);
1935
1936                         /* current state still has to be D_FAILED,
1937                          * there is only one way out: to D_DISKLESS,
1938                          * and that may only happen after our put_ldev below. */
1939                         if (device->state.disk != D_FAILED)
1940                                 drbd_err(device,
1941                                         "ASSERT FAILED: disk is %s during detach\n",
1942                                         drbd_disk_str(device->state.disk));
1943
1944                         if (ns.conn >= C_CONNECTED)
1945                                 drbd_send_state(peer_device, ns);
1946
1947                         drbd_rs_cancel_all(device);
1948
1949                         /* In case we want to get something to stable storage still,
1950                          * this may be the last chance.
1951                          * Following put_ldev may transition to D_DISKLESS. */
1952                         drbd_md_sync(device);
1953                 }
1954                 put_ldev(device);
1955         }
1956
1957         /* second half of local IO error, failure to attach,
1958          * or administrative detach,
1959          * after local_cnt references have reached zero again */
1960         if (os.disk != D_DISKLESS && ns.disk == D_DISKLESS) {
1961                 /* We must still be diskless,
1962                  * re-attach has to be serialized with this! */
1963                 if (device->state.disk != D_DISKLESS)
1964                         drbd_err(device,
1965                                  "ASSERT FAILED: disk is %s while going diskless\n",
1966                                  drbd_disk_str(device->state.disk));
1967
1968                 if (ns.conn >= C_CONNECTED)
1969                         drbd_send_state(peer_device, ns);
1970                 /* corresponding get_ldev in __drbd_set_state
1971                  * this may finally trigger drbd_ldev_destroy. */
1972                 put_ldev(device);
1973         }
1974
1975         /* Notify peer that I had a local IO error, and did not detached.. */
1976         if (os.disk == D_UP_TO_DATE && ns.disk == D_INCONSISTENT && ns.conn >= C_CONNECTED)
1977                 drbd_send_state(peer_device, ns);
1978
1979         /* Disks got bigger while they were detached */
1980         if (ns.disk > D_NEGOTIATING && ns.pdsk > D_NEGOTIATING &&
1981             test_and_clear_bit(RESYNC_AFTER_NEG, &device->flags)) {
1982                 if (ns.conn == C_CONNECTED)
1983                         resync_after_online_grow(device);
1984         }
1985
1986         /* A resync finished or aborted, wake paused devices... */
1987         if ((os.conn > C_CONNECTED && ns.conn <= C_CONNECTED) ||
1988             (os.peer_isp && !ns.peer_isp) ||
1989             (os.user_isp && !ns.user_isp))
1990                 resume_next_sg(device);
1991
1992         /* sync target done with resync.  Explicitly notify peer, even though
1993          * it should (at least for non-empty resyncs) already know itself. */
1994         if (os.disk < D_UP_TO_DATE && os.conn >= C_SYNC_SOURCE && ns.conn == C_CONNECTED)
1995                 drbd_send_state(peer_device, ns);
1996
1997         /* Verify finished, or reached stop sector.  Peer did not know about
1998          * the stop sector, and we may even have changed the stop sector during
1999          * verify to interrupt/stop early.  Send the new state. */
2000         if (os.conn == C_VERIFY_S && ns.conn == C_CONNECTED
2001         && verify_can_do_stop_sector(device))
2002                 drbd_send_state(peer_device, ns);
2003
2004         /* This triggers bitmap writeout of potentially still unwritten pages
2005          * if the resync finished cleanly, or aborted because of peer disk
2006          * failure, or on transition from resync back to AHEAD/BEHIND.
2007          *
2008          * Connection loss is handled in drbd_disconnected() by the receiver.
2009          *
2010          * For resync aborted because of local disk failure, we cannot do
2011          * any bitmap writeout anymore.
2012          *
2013          * No harm done if some bits change during this phase.
2014          */
2015         if ((os.conn > C_CONNECTED && os.conn < C_AHEAD) &&
2016             (ns.conn == C_CONNECTED || ns.conn >= C_AHEAD) && get_ldev(device)) {
2017                 drbd_queue_bitmap_io(device, &drbd_bm_write_copy_pages, NULL,
2018                         "write from resync_finished", BM_LOCKED_CHANGE_ALLOWED,
2019                         peer_device);
2020                 put_ldev(device);
2021         }
2022
2023         if (ns.disk == D_DISKLESS &&
2024             ns.conn == C_STANDALONE &&
2025             ns.role == R_SECONDARY) {
2026                 if (os.aftr_isp != ns.aftr_isp)
2027                         resume_next_sg(device);
2028         }
2029
2030         drbd_md_sync(device);
2031 }
2032
2033 struct after_conn_state_chg_work {
2034         struct drbd_work w;
2035         enum drbd_conns oc;
2036         union drbd_state ns_min;
2037         union drbd_state ns_max; /* new, max state, over all devices */
2038         enum chg_state_flags flags;
2039         struct drbd_connection *connection;
2040         struct drbd_state_change *state_change;
2041 };
2042
2043 static int w_after_conn_state_ch(struct drbd_work *w, int unused)
2044 {
2045         struct after_conn_state_chg_work *acscw =
2046                 container_of(w, struct after_conn_state_chg_work, w);
2047         struct drbd_connection *connection = acscw->connection;
2048         enum drbd_conns oc = acscw->oc;
2049         union drbd_state ns_max = acscw->ns_max;
2050         struct drbd_peer_device *peer_device;
2051         int vnr;
2052
2053         broadcast_state_change(acscw->state_change);
2054         forget_state_change(acscw->state_change);
2055         kfree(acscw);
2056
2057         /* Upon network configuration, we need to start the receiver */
2058         if (oc == C_STANDALONE && ns_max.conn == C_UNCONNECTED)
2059                 drbd_thread_start(&connection->receiver);
2060
2061         if (oc == C_DISCONNECTING && ns_max.conn == C_STANDALONE) {
2062                 struct net_conf *old_conf;
2063
2064                 mutex_lock(&notification_mutex);
2065                 idr_for_each_entry(&connection->peer_devices, peer_device, vnr)
2066                         notify_peer_device_state(NULL, 0, peer_device, NULL,
2067                                                  NOTIFY_DESTROY | NOTIFY_CONTINUES);
2068                 notify_connection_state(NULL, 0, connection, NULL, NOTIFY_DESTROY);
2069                 mutex_unlock(&notification_mutex);
2070
2071                 mutex_lock(&connection->resource->conf_update);
2072                 old_conf = connection->net_conf;
2073                 connection->my_addr_len = 0;
2074                 connection->peer_addr_len = 0;
2075                 RCU_INIT_POINTER(connection->net_conf, NULL);
2076                 conn_free_crypto(connection);
2077                 mutex_unlock(&connection->resource->conf_update);
2078
2079                 kvfree_rcu_mightsleep(old_conf);
2080         }
2081
2082         if (ns_max.susp_fen) {
2083                 /* case1: The outdate peer handler is successful: */
2084                 if (ns_max.pdsk <= D_OUTDATED) {
2085                         rcu_read_lock();
2086                         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2087                                 struct drbd_device *device = peer_device->device;
2088                                 if (test_bit(NEW_CUR_UUID, &device->flags)) {
2089                                         drbd_uuid_new_current(device);
2090                                         clear_bit(NEW_CUR_UUID, &device->flags);
2091                                 }
2092                         }
2093                         rcu_read_unlock();
2094                         spin_lock_irq(&connection->resource->req_lock);
2095                         _tl_restart(connection, CONNECTION_LOST_WHILE_PENDING);
2096                         _conn_request_state(connection,
2097                                             (union drbd_state) { { .susp_fen = 1 } },
2098                                             (union drbd_state) { { .susp_fen = 0 } },
2099                                             CS_VERBOSE);
2100                         spin_unlock_irq(&connection->resource->req_lock);
2101                 }
2102         }
2103         conn_md_sync(connection);
2104         kref_put(&connection->kref, drbd_destroy_connection);
2105
2106         return 0;
2107 }
2108
2109 static void conn_old_common_state(struct drbd_connection *connection, union drbd_state *pcs, enum chg_state_flags *pf)
2110 {
2111         enum chg_state_flags flags = ~0;
2112         struct drbd_peer_device *peer_device;
2113         int vnr, first_vol = 1;
2114         union drbd_dev_state os, cs = {
2115                 { .role = R_SECONDARY,
2116                   .peer = R_UNKNOWN,
2117                   .conn = connection->cstate,
2118                   .disk = D_DISKLESS,
2119                   .pdsk = D_UNKNOWN,
2120                 } };
2121
2122         rcu_read_lock();
2123         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2124                 struct drbd_device *device = peer_device->device;
2125                 os = device->state;
2126
2127                 if (first_vol) {
2128                         cs = os;
2129                         first_vol = 0;
2130                         continue;
2131                 }
2132
2133                 if (cs.role != os.role)
2134                         flags &= ~CS_DC_ROLE;
2135
2136                 if (cs.peer != os.peer)
2137                         flags &= ~CS_DC_PEER;
2138
2139                 if (cs.conn != os.conn)
2140                         flags &= ~CS_DC_CONN;
2141
2142                 if (cs.disk != os.disk)
2143                         flags &= ~CS_DC_DISK;
2144
2145                 if (cs.pdsk != os.pdsk)
2146                         flags &= ~CS_DC_PDSK;
2147         }
2148         rcu_read_unlock();
2149
2150         *pf |= CS_DC_MASK;
2151         *pf &= flags;
2152         (*pcs).i = cs.i;
2153 }
2154
2155 static enum drbd_state_rv
2156 conn_is_valid_transition(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2157                          enum chg_state_flags flags)
2158 {
2159         enum drbd_state_rv rv = SS_SUCCESS;
2160         union drbd_state ns, os;
2161         struct drbd_peer_device *peer_device;
2162         int vnr;
2163
2164         rcu_read_lock();
2165         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2166                 struct drbd_device *device = peer_device->device;
2167                 os = drbd_read_state(device);
2168                 ns = sanitize_state(device, os, apply_mask_val(os, mask, val), NULL);
2169
2170                 if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
2171                         ns.disk = os.disk;
2172
2173                 if (ns.i == os.i)
2174                         continue;
2175
2176                 rv = is_valid_transition(os, ns);
2177
2178                 if (rv >= SS_SUCCESS && !(flags & CS_HARD)) {
2179                         rv = is_valid_state(device, ns);
2180                         if (rv < SS_SUCCESS) {
2181                                 if (is_valid_state(device, os) == rv)
2182                                         rv = is_valid_soft_transition(os, ns, connection);
2183                         } else
2184                                 rv = is_valid_soft_transition(os, ns, connection);
2185                 }
2186
2187                 if (rv < SS_SUCCESS) {
2188                         if (flags & CS_VERBOSE)
2189                                 print_st_err(device, os, ns, rv);
2190                         break;
2191                 }
2192         }
2193         rcu_read_unlock();
2194
2195         return rv;
2196 }
2197
2198 static void
2199 conn_set_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2200                union drbd_state *pns_min, union drbd_state *pns_max, enum chg_state_flags flags)
2201 {
2202         union drbd_state ns, os, ns_max = { };
2203         union drbd_state ns_min = {
2204                 { .role = R_MASK,
2205                   .peer = R_MASK,
2206                   .conn = val.conn,
2207                   .disk = D_MASK,
2208                   .pdsk = D_MASK
2209                 } };
2210         struct drbd_peer_device *peer_device;
2211         enum drbd_state_rv rv;
2212         int vnr, number_of_volumes = 0;
2213
2214         if (mask.conn == C_MASK) {
2215                 /* remember last connect time so request_timer_fn() won't
2216                  * kill newly established sessions while we are still trying to thaw
2217                  * previously frozen IO */
2218                 if (connection->cstate != C_WF_REPORT_PARAMS && val.conn == C_WF_REPORT_PARAMS)
2219                         connection->last_reconnect_jif = jiffies;
2220
2221                 connection->cstate = val.conn;
2222         }
2223
2224         rcu_read_lock();
2225         idr_for_each_entry(&connection->peer_devices, peer_device, vnr) {
2226                 struct drbd_device *device = peer_device->device;
2227                 number_of_volumes++;
2228                 os = drbd_read_state(device);
2229                 ns = apply_mask_val(os, mask, val);
2230                 ns = sanitize_state(device, os, ns, NULL);
2231
2232                 if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
2233                         ns.disk = os.disk;
2234
2235                 rv = _drbd_set_state(device, ns, flags, NULL);
2236                 BUG_ON(rv < SS_SUCCESS);
2237                 ns.i = device->state.i;
2238                 ns_max.role = max_role(ns.role, ns_max.role);
2239                 ns_max.peer = max_role(ns.peer, ns_max.peer);
2240                 ns_max.conn = max_t(enum drbd_conns, ns.conn, ns_max.conn);
2241                 ns_max.disk = max_t(enum drbd_disk_state, ns.disk, ns_max.disk);
2242                 ns_max.pdsk = max_t(enum drbd_disk_state, ns.pdsk, ns_max.pdsk);
2243
2244                 ns_min.role = min_role(ns.role, ns_min.role);
2245                 ns_min.peer = min_role(ns.peer, ns_min.peer);
2246                 ns_min.conn = min_t(enum drbd_conns, ns.conn, ns_min.conn);
2247                 ns_min.disk = min_t(enum drbd_disk_state, ns.disk, ns_min.disk);
2248                 ns_min.pdsk = min_t(enum drbd_disk_state, ns.pdsk, ns_min.pdsk);
2249         }
2250         rcu_read_unlock();
2251
2252         if (number_of_volumes == 0) {
2253                 ns_min = ns_max = (union drbd_state) { {
2254                                 .role = R_SECONDARY,
2255                                 .peer = R_UNKNOWN,
2256                                 .conn = val.conn,
2257                                 .disk = D_DISKLESS,
2258                                 .pdsk = D_UNKNOWN
2259                         } };
2260         }
2261
2262         ns_min.susp = ns_max.susp = connection->resource->susp;
2263         ns_min.susp_nod = ns_max.susp_nod = connection->resource->susp_nod;
2264         ns_min.susp_fen = ns_max.susp_fen = connection->resource->susp_fen;
2265
2266         *pns_min = ns_min;
2267         *pns_max = ns_max;
2268 }
2269
2270 static enum drbd_state_rv
2271 _conn_rq_cond(struct drbd_connection *connection, union drbd_state mask, union drbd_state val)
2272 {
2273         enum drbd_state_rv err, rv = SS_UNKNOWN_ERROR; /* continue waiting */;
2274
2275         if (test_and_clear_bit(CONN_WD_ST_CHG_OKAY, &connection->flags))
2276                 rv = SS_CW_SUCCESS;
2277
2278         if (test_and_clear_bit(CONN_WD_ST_CHG_FAIL, &connection->flags))
2279                 rv = SS_CW_FAILED_BY_PEER;
2280
2281         err = conn_is_valid_transition(connection, mask, val, 0);
2282         if (err == SS_SUCCESS && connection->cstate == C_WF_REPORT_PARAMS)
2283                 return rv;
2284
2285         return err;
2286 }
2287
2288 enum drbd_state_rv
2289 _conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2290                     enum chg_state_flags flags)
2291 {
2292         enum drbd_state_rv rv = SS_SUCCESS;
2293         struct after_conn_state_chg_work *acscw;
2294         enum drbd_conns oc = connection->cstate;
2295         union drbd_state ns_max, ns_min, os;
2296         bool have_mutex = false;
2297         struct drbd_state_change *state_change;
2298
2299         if (mask.conn) {
2300                 rv = is_valid_conn_transition(oc, val.conn);
2301                 if (rv < SS_SUCCESS)
2302                         goto abort;
2303         }
2304
2305         rv = conn_is_valid_transition(connection, mask, val, flags);
2306         if (rv < SS_SUCCESS)
2307                 goto abort;
2308
2309         if (oc == C_WF_REPORT_PARAMS && val.conn == C_DISCONNECTING &&
2310             !(flags & (CS_LOCAL_ONLY | CS_HARD))) {
2311
2312                 /* This will be a cluster-wide state change.
2313                  * Need to give up the spinlock, grab the mutex,
2314                  * then send the state change request, ... */
2315                 spin_unlock_irq(&connection->resource->req_lock);
2316                 mutex_lock(&connection->cstate_mutex);
2317                 have_mutex = true;
2318
2319                 set_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
2320                 if (conn_send_state_req(connection, mask, val)) {
2321                         /* sending failed. */
2322                         clear_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
2323                         rv = SS_CW_FAILED_BY_PEER;
2324                         /* need to re-aquire the spin lock, though */
2325                         goto abort_unlocked;
2326                 }
2327
2328                 if (val.conn == C_DISCONNECTING)
2329                         set_bit(DISCONNECT_SENT, &connection->flags);
2330
2331                 /* ... and re-aquire the spinlock.
2332                  * If _conn_rq_cond() returned >= SS_SUCCESS, we must call
2333                  * conn_set_state() within the same spinlock. */
2334                 spin_lock_irq(&connection->resource->req_lock);
2335                 wait_event_lock_irq(connection->ping_wait,
2336                                 (rv = _conn_rq_cond(connection, mask, val)),
2337                                 connection->resource->req_lock);
2338                 clear_bit(CONN_WD_ST_CHG_REQ, &connection->flags);
2339                 if (rv < SS_SUCCESS)
2340                         goto abort;
2341         }
2342
2343         state_change = remember_old_state(connection->resource, GFP_ATOMIC);
2344         conn_old_common_state(connection, &os, &flags);
2345         flags |= CS_DC_SUSP;
2346         conn_set_state(connection, mask, val, &ns_min, &ns_max, flags);
2347         conn_pr_state_change(connection, os, ns_max, flags);
2348         remember_new_state(state_change);
2349
2350         acscw = kmalloc(sizeof(*acscw), GFP_ATOMIC);
2351         if (acscw) {
2352                 acscw->oc = os.conn;
2353                 acscw->ns_min = ns_min;
2354                 acscw->ns_max = ns_max;
2355                 acscw->flags = flags;
2356                 acscw->w.cb = w_after_conn_state_ch;
2357                 kref_get(&connection->kref);
2358                 acscw->connection = connection;
2359                 acscw->state_change = state_change;
2360                 drbd_queue_work(&connection->sender_work, &acscw->w);
2361         } else {
2362                 drbd_err(connection, "Could not kmalloc an acscw\n");
2363         }
2364
2365  abort:
2366         if (have_mutex) {
2367                 /* mutex_unlock() "... must not be used in interrupt context.",
2368                  * so give up the spinlock, then re-aquire it */
2369                 spin_unlock_irq(&connection->resource->req_lock);
2370  abort_unlocked:
2371                 mutex_unlock(&connection->cstate_mutex);
2372                 spin_lock_irq(&connection->resource->req_lock);
2373         }
2374         if (rv < SS_SUCCESS && flags & CS_VERBOSE) {
2375                 drbd_err(connection, "State change failed: %s\n", drbd_set_st_err_str(rv));
2376                 drbd_err(connection, " mask = 0x%x val = 0x%x\n", mask.i, val.i);
2377                 drbd_err(connection, " old_conn:%s wanted_conn:%s\n", drbd_conn_str(oc), drbd_conn_str(val.conn));
2378         }
2379         return rv;
2380 }
2381
2382 enum drbd_state_rv
2383 conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,
2384                    enum chg_state_flags flags)
2385 {
2386         enum drbd_state_rv rv;
2387
2388         spin_lock_irq(&connection->resource->req_lock);
2389         rv = _conn_request_state(connection, mask, val, flags);
2390         spin_unlock_irq(&connection->resource->req_lock);
2391
2392         return rv;
2393 }