drivers/block/drbd/drbd_state.c

   1 /*
   2    drbd_state.c
   3
   4    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   5
   6    Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   7    Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   8    Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
   9
  10    Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev
  11    from Logicworks, Inc. for making SDP replication support possible.
  12
  13    drbd is free software; you can redistribute it and/or modify
  14    it under the terms of the GNU General Public License as published by
  15    the Free Software Foundation; either version 2, or (at your option)
  16    any later version.
  17
  18    drbd is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with drbd; see the file COPYING.  If not, write to
  25    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include <linux/drbd_limits.h>
  29 #include "drbd_int.h"
  30 #include "drbd_req.h"
  31
  32 /* in drbd_main.c */
  33 extern void tl_abort_disk_io(struct drbd_conf *mdev);
  34
  35 struct after_state_chg_work {
  36         struct drbd_work w;
  37         union drbd_state os;
  38         union drbd_state ns;
  39         enum chg_state_flags flags;
  40         struct completion *done;
  41 };
  42
  43 enum sanitize_state_warnings {
  44         NO_WARNING,
  45         ABORTED_ONLINE_VERIFY,
  46         ABORTED_RESYNC,
  47         CONNECTION_LOST_NEGOTIATING,
  48         IMPLICITLY_UPGRADED_DISK,
  49         IMPLICITLY_UPGRADED_PDSK,
  50 };
  51
  52 static int w_after_state_ch(struct drbd_work *w, int unused);
  53 static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
  54                            union drbd_state ns, enum chg_state_flags flags);
  55 static enum drbd_state_rv is_valid_state(struct drbd_conf *, union drbd_state);
  56 static enum drbd_state_rv is_valid_soft_transition(union drbd_state, union drbd_state, struct drbd_tconn *);
  57 static enum drbd_state_rv is_valid_transition(union drbd_state os, union drbd_state ns);
  58 static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state ns,
  59                                        enum sanitize_state_warnings *warn);
  60
  61 static inline bool is_susp(union drbd_state s)
  62 {
  63         return s.susp || s.susp_nod || s.susp_fen;
  64 }
  65
  66 bool conn_all_vols_unconf(struct drbd_tconn *tconn)
  67 {
  68         struct drbd_conf *mdev;
  69         bool rv = true;
  70         int vnr;
  71
  72         rcu_read_lock();
  73         idr_for_each_entry(&tconn->volumes, mdev, vnr) {
  74                 if (mdev->state.disk != D_DISKLESS ||
  75                     mdev->state.conn != C_STANDALONE ||
  76                     mdev->state.role != R_SECONDARY) {
  77                         rv = false;
  78                         break;
  79                 }
  80         }
  81         rcu_read_unlock();
  82
  83         return rv;
  84 }
  85
  86 /* Unfortunately the states where not correctly ordered, when
  87    they where defined. therefore can not use max_t() here. */
  88 static enum drbd_role max_role(enum drbd_role role1, enum drbd_role role2)
  89 {
  90         if (role1 == R_PRIMARY || role2 == R_PRIMARY)
  91                 return R_PRIMARY;
  92         if (role1 == R_SECONDARY || role2 == R_SECONDARY)
  93                 return R_SECONDARY;
  94         return R_UNKNOWN;
  95 }
  96 static enum drbd_role min_role(enum drbd_role role1, enum drbd_role role2)
  97 {
  98         if (role1 == R_UNKNOWN || role2 == R_UNKNOWN)
  99                 return R_UNKNOWN;
 100         if (role1 == R_SECONDARY || role2 == R_SECONDARY)
 101                 return R_SECONDARY;
 102         return R_PRIMARY;
 103 }
 104
 105 enum drbd_role conn_highest_role(struct drbd_tconn *tconn)
 106 {
 107         enum drbd_role role = R_UNKNOWN;
 108         struct drbd_conf *mdev;
 109         int vnr;
 110
 111         rcu_read_lock();
 112         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 113                 role = max_role(role, mdev->state.role);
 114         rcu_read_unlock();
 115
 116         return role;
 117 }
 118
 119 enum drbd_role conn_highest_peer(struct drbd_tconn *tconn)
 120 {
 121         enum drbd_role peer = R_UNKNOWN;
 122         struct drbd_conf *mdev;
 123         int vnr;
 124
 125         rcu_read_lock();
 126         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 127                 peer = max_role(peer, mdev->state.peer);
 128         rcu_read_unlock();
 129
 130         return peer;
 131 }
 132
 133 enum drbd_disk_state conn_highest_disk(struct drbd_tconn *tconn)
 134 {
 135         enum drbd_disk_state ds = D_DISKLESS;
 136         struct drbd_conf *mdev;
 137         int vnr;
 138
 139         rcu_read_lock();
 140         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 141                 ds = max_t(enum drbd_disk_state, ds, mdev->state.disk);
 142         rcu_read_unlock();
 143
 144         return ds;
 145 }
 146
 147 enum drbd_disk_state conn_lowest_disk(struct drbd_tconn *tconn)
 148 {
 149         enum drbd_disk_state ds = D_MASK;
 150         struct drbd_conf *mdev;
 151         int vnr;
 152
 153         rcu_read_lock();
 154         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 155                 ds = min_t(enum drbd_disk_state, ds, mdev->state.disk);
 156         rcu_read_unlock();
 157
 158         return ds;
 159 }
 160
 161 enum drbd_disk_state conn_highest_pdsk(struct drbd_tconn *tconn)
 162 {
 163         enum drbd_disk_state ds = D_DISKLESS;
 164         struct drbd_conf *mdev;
 165         int vnr;
 166
 167         rcu_read_lock();
 168         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 169                 ds = max_t(enum drbd_disk_state, ds, mdev->state.pdsk);
 170         rcu_read_unlock();
 171
 172         return ds;
 173 }
 174
 175 enum drbd_conns conn_lowest_conn(struct drbd_tconn *tconn)
 176 {
 177         enum drbd_conns conn = C_MASK;
 178         struct drbd_conf *mdev;
 179         int vnr;
 180
 181         rcu_read_lock();
 182         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 183                 conn = min_t(enum drbd_conns, conn, mdev->state.conn);
 184         rcu_read_unlock();
 185
 186         return conn;
 187 }
 188
 189 static bool no_peer_wf_report_params(struct drbd_tconn *tconn)
 190 {
 191         struct drbd_conf *mdev;
 192         int vnr;
 193         bool rv = true;
 194
 195         rcu_read_lock();
 196         idr_for_each_entry(&tconn->volumes, mdev, vnr)
 197                 if (mdev->state.conn == C_WF_REPORT_PARAMS) {
 198                         rv = false;
 199                         break;
 200                 }
 201         rcu_read_unlock();
 202
 203         return rv;
 204 }
 205
 206
 207 /**
 208  * cl_wide_st_chg() - true if the state change is a cluster wide one
 209  * @mdev:       DRBD device.
 210  * @os:         old (current) state.
 211  * @ns:         new (wanted) state.
 212  */
 213 static int cl_wide_st_chg(struct drbd_conf *mdev,
 214                           union drbd_state os, union drbd_state ns)
 215 {
 216         return (os.conn >= C_CONNECTED && ns.conn >= C_CONNECTED &&
 217                  ((os.role != R_PRIMARY && ns.role == R_PRIMARY) ||
 218                   (os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
 219                   (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S) ||
 220                   (os.disk != D_FAILED && ns.disk == D_FAILED))) ||
 221                 (os.conn >= C_CONNECTED && ns.conn == C_DISCONNECTING) ||
 222                 (os.conn == C_CONNECTED && ns.conn == C_VERIFY_S) ||
 223                 (os.conn == C_CONNECTED && ns.conn == C_WF_REPORT_PARAMS);
 224 }
 225
 226 static union drbd_state
 227 apply_mask_val(union drbd_state os, union drbd_state mask, union drbd_state val)
 228 {
 229         union drbd_state ns;
 230         ns.i = (os.i & ~mask.i) | val.i;
 231         return ns;
 232 }
 233
 234 enum drbd_state_rv
 235 drbd_change_state(struct drbd_conf *mdev, enum chg_state_flags f,
 236                   union drbd_state mask, union drbd_state val)
 237 {
 238         unsigned long flags;
 239         union drbd_state ns;
 240         enum drbd_state_rv rv;
 241
 242         spin_lock_irqsave(&mdev->tconn->req_lock, flags);
 243         ns = apply_mask_val(drbd_read_state(mdev), mask, val);
 244         rv = _drbd_set_state(mdev, ns, f, NULL);
 245         spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 246
 247         return rv;
 248 }
 249
 250 /**
 251  * drbd_force_state() - Impose a change which happens outside our control on our state
 252  * @mdev:       DRBD device.
 253  * @mask:       mask of state bits to change.
 254  * @val:        value of new state bits.
 255  */
 256 void drbd_force_state(struct drbd_conf *mdev,
 257         union drbd_state mask, union drbd_state val)
 258 {
 259         drbd_change_state(mdev, CS_HARD, mask, val);
 260 }
 261
 262 static enum drbd_state_rv
 263 _req_st_cond(struct drbd_conf *mdev, union drbd_state mask,
 264              union drbd_state val)
 265 {
 266         union drbd_state os, ns;
 267         unsigned long flags;
 268         enum drbd_state_rv rv;
 269
 270         if (test_and_clear_bit(CL_ST_CHG_SUCCESS, &mdev->flags))
 271                 return SS_CW_SUCCESS;
 272
 273         if (test_and_clear_bit(CL_ST_CHG_FAIL, &mdev->flags))
 274                 return SS_CW_FAILED_BY_PEER;
 275
 276         spin_lock_irqsave(&mdev->tconn->req_lock, flags);
 277         os = drbd_read_state(mdev);
 278         ns = sanitize_state(mdev, apply_mask_val(os, mask, val), NULL);
 279         rv = is_valid_transition(os, ns);
 280         if (rv >= SS_SUCCESS)
 281                 rv = SS_UNKNOWN_ERROR;  /* cont waiting, otherwise fail. */
 282
 283         if (!cl_wide_st_chg(mdev, os, ns))
 284                 rv = SS_CW_NO_NEED;
 285         if (rv == SS_UNKNOWN_ERROR) {
 286                 rv = is_valid_state(mdev, ns);
 287                 if (rv >= SS_SUCCESS) {
 288                         rv = is_valid_soft_transition(os, ns, mdev->tconn);
 289                         if (rv >= SS_SUCCESS)
 290                                 rv = SS_UNKNOWN_ERROR; /* cont waiting, otherwise fail. */
 291                 }
 292         }
 293         spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 294
 295         return rv;
 296 }
 297
 298 /**
 299  * drbd_req_state() - Perform an eventually cluster wide state change
 300  * @mdev:       DRBD device.
 301  * @mask:       mask of state bits to change.
 302  * @val:        value of new state bits.
 303  * @f:          flags
 304  *
 305  * Should not be called directly, use drbd_request_state() or
 306  * _drbd_request_state().
 307  */
 308 static enum drbd_state_rv
 309 drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
 310                union drbd_state val, enum chg_state_flags f)
 311 {
 312         struct completion done;
 313         unsigned long flags;
 314         union drbd_state os, ns;
 315         enum drbd_state_rv rv;
 316
 317         init_completion(&done);
 318
 319         if (f & CS_SERIALIZE)
 320                 mutex_lock(mdev->state_mutex);
 321
 322         spin_lock_irqsave(&mdev->tconn->req_lock, flags);
 323         os = drbd_read_state(mdev);
 324         ns = sanitize_state(mdev, apply_mask_val(os, mask, val), NULL);
 325         rv = is_valid_transition(os, ns);
 326         if (rv < SS_SUCCESS) {
 327                 spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 328                 goto abort;
 329         }
 330
 331         if (cl_wide_st_chg(mdev, os, ns)) {
 332                 rv = is_valid_state(mdev, ns);
 333                 if (rv == SS_SUCCESS)
 334                         rv = is_valid_soft_transition(os, ns, mdev->tconn);
 335                 spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 336
 337                 if (rv < SS_SUCCESS) {
 338                         if (f & CS_VERBOSE)
 339                                 print_st_err(mdev, os, ns, rv);
 340                         goto abort;
 341                 }
 342
 343                 if (drbd_send_state_req(mdev, mask, val)) {
 344                         rv = SS_CW_FAILED_BY_PEER;
 345                         if (f & CS_VERBOSE)
 346                                 print_st_err(mdev, os, ns, rv);
 347                         goto abort;
 348                 }
 349
 350                 wait_event(mdev->state_wait,
 351                         (rv = _req_st_cond(mdev, mask, val)));
 352
 353                 if (rv < SS_SUCCESS) {
 354                         if (f & CS_VERBOSE)
 355                                 print_st_err(mdev, os, ns, rv);
 356                         goto abort;
 357                 }
 358                 spin_lock_irqsave(&mdev->tconn->req_lock, flags);
 359                 ns = apply_mask_val(drbd_read_state(mdev), mask, val);
 360                 rv = _drbd_set_state(mdev, ns, f, &done);
 361         } else {
 362                 rv = _drbd_set_state(mdev, ns, f, &done);
 363         }
 364
 365         spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
 366
 367         if (f & CS_WAIT_COMPLETE && rv == SS_SUCCESS) {
 368                 D_ASSERT(current != mdev->tconn->worker.task);
 369                 wait_for_completion(&done);
 370         }
 371
 372 abort:
 373         if (f & CS_SERIALIZE)
 374                 mutex_unlock(mdev->state_mutex);
 375
 376         return rv;
 377 }
 378
 379 /**
 380  * _drbd_request_state() - Request a state change (with flags)
 381  * @mdev:       DRBD device.
 382  * @mask:       mask of state bits to change.
 383  * @val:        value of new state bits.
 384  * @f:          flags
 385  *
 386  * Cousin of drbd_request_state(), useful with the CS_WAIT_COMPLETE
 387  * flag, or when logging of failed state change requests is not desired.
 388  */
 389 enum drbd_state_rv
 390 _drbd_request_state(struct drbd_conf *mdev, union drbd_state mask,
 391                     union drbd_state val, enum chg_state_flags f)
 392 {
 393         enum drbd_state_rv rv;
 394
 395         wait_event(mdev->state_wait,
 396                    (rv = drbd_req_state(mdev, mask, val, f)) != SS_IN_TRANSIENT_STATE);
 397
 398         return rv;
 399 }
 400
 401 static void print_st(struct drbd_conf *mdev, char *name, union drbd_state ns)
 402 {
 403         dev_err(DEV, " %s = { cs:%s ro:%s/%s ds:%s/%s %c%c%c%c%c%c }\n",
 404             name,
 405             drbd_conn_str(ns.conn),
 406             drbd_role_str(ns.role),
 407             drbd_role_str(ns.peer),
 408             drbd_disk_str(ns.disk),
 409             drbd_disk_str(ns.pdsk),
 410             is_susp(ns) ? 's' : 'r',
 411             ns.aftr_isp ? 'a' : '-',
 412             ns.peer_isp ? 'p' : '-',
 413             ns.user_isp ? 'u' : '-',
 414             ns.susp_fen ? 'F' : '-',
 415             ns.susp_nod ? 'N' : '-'
 416             );
 417 }
 418
 419 void print_st_err(struct drbd_conf *mdev, union drbd_state os,
 420                   union drbd_state ns, enum drbd_state_rv err)
 421 {
 422         if (err == SS_IN_TRANSIENT_STATE)
 423                 return;
 424         dev_err(DEV, "State change failed: %s\n", drbd_set_st_err_str(err));
 425         print_st(mdev, " state", os);
 426         print_st(mdev, "wanted", ns);
 427 }
 428
 429 static long print_state_change(char *pb, union drbd_state os, union drbd_state ns,
 430                                enum chg_state_flags flags)
 431 {
 432         char *pbp;
 433         pbp = pb;
 434         *pbp = 0;
 435
 436         if (ns.role != os.role && flags & CS_DC_ROLE)
 437                 pbp += sprintf(pbp, "role( %s -> %s ) ",
 438                                drbd_role_str(os.role),
 439                                drbd_role_str(ns.role));
 440         if (ns.peer != os.peer && flags & CS_DC_PEER)
 441                 pbp += sprintf(pbp, "peer( %s -> %s ) ",
 442                                drbd_role_str(os.peer),
 443                                drbd_role_str(ns.peer));
 444         if (ns.conn != os.conn && flags & CS_DC_CONN)
 445                 pbp += sprintf(pbp, "conn( %s -> %s ) ",
 446                                drbd_conn_str(os.conn),
 447                                drbd_conn_str(ns.conn));
 448         if (ns.disk != os.disk && flags & CS_DC_DISK)
 449                 pbp += sprintf(pbp, "disk( %s -> %s ) ",
 450                                drbd_disk_str(os.disk),
 451                                drbd_disk_str(ns.disk));
 452         if (ns.pdsk != os.pdsk && flags & CS_DC_PDSK)
 453                 pbp += sprintf(pbp, "pdsk( %s -> %s ) ",
 454                                drbd_disk_str(os.pdsk),
 455                                drbd_disk_str(ns.pdsk));
 456
 457         return pbp - pb;
 458 }
 459
 460 static void drbd_pr_state_change(struct drbd_conf *mdev, union drbd_state os, union drbd_state ns,
 461                                  enum chg_state_flags flags)
 462 {
 463         char pb[300];
 464         char *pbp = pb;
 465
 466         pbp += print_state_change(pbp, os, ns, flags ^ CS_DC_MASK);
 467
 468         if (ns.aftr_isp != os.aftr_isp)
 469                 pbp += sprintf(pbp, "aftr_isp( %d -> %d ) ",
 470                                os.aftr_isp,
 471                                ns.aftr_isp);
 472         if (ns.peer_isp != os.peer_isp)
 473                 pbp += sprintf(pbp, "peer_isp( %d -> %d ) ",
 474                                os.peer_isp,
 475                                ns.peer_isp);
 476         if (ns.user_isp != os.user_isp)
 477                 pbp += sprintf(pbp, "user_isp( %d -> %d ) ",
 478                                os.user_isp,
 479                                ns.user_isp);
 480
 481         if (pbp != pb)
 482                 dev_info(DEV, "%s\n", pb);
 483 }
 484
 485 static void conn_pr_state_change(struct drbd_tconn *tconn, union drbd_state os, union drbd_state ns,
 486                                  enum chg_state_flags flags)
 487 {
 488         char pb[300];
 489         char *pbp = pb;
 490
 491         pbp += print_state_change(pbp, os, ns, flags);
 492
 493         if (is_susp(ns) != is_susp(os) && flags & CS_DC_SUSP)
 494                 pbp += sprintf(pbp, "susp( %d -> %d ) ",
 495                                is_susp(os),
 496                                is_susp(ns));
 497
 498         if (pbp != pb)
 499                 conn_info(tconn, "%s\n", pb);
 500 }
 501
 502
 503 /**
 504  * is_valid_state() - Returns an SS_ error code if ns is not valid
 505  * @mdev:       DRBD device.
 506  * @ns:         State to consider.
 507  */
 508 static enum drbd_state_rv
 509 is_valid_state(struct drbd_conf *mdev, union drbd_state ns)
 510 {
 511         /* See drbd_state_sw_errors in drbd_strings.c */
 512
 513         enum drbd_fencing_p fp;
 514         enum drbd_state_rv rv = SS_SUCCESS;
 515         struct net_conf *nc;
 516
 517         rcu_read_lock();
 518         fp = FP_DONT_CARE;
 519         if (get_ldev(mdev)) {
 520                 fp = rcu_dereference(mdev->ldev->disk_conf)->fencing;
 521                 put_ldev(mdev);
 522         }
 523
 524         nc = rcu_dereference(mdev->tconn->net_conf);
 525         if (nc) {
 526                 if (!nc->two_primaries && ns.role == R_PRIMARY) {
 527                         if (ns.peer == R_PRIMARY)
 528                                 rv = SS_TWO_PRIMARIES;
 529                         else if (conn_highest_peer(mdev->tconn) == R_PRIMARY)
 530                                 rv = SS_O_VOL_PEER_PRI;
 531                 }
 532         }
 533
 534         if (rv <= 0)
 535                 /* already found a reason to abort */;
 536         else if (ns.role == R_SECONDARY && mdev->open_cnt)
 537                 rv = SS_DEVICE_IN_USE;
 538
 539         else if (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.disk < D_UP_TO_DATE)
 540                 rv = SS_NO_UP_TO_DATE_DISK;
 541
 542         else if (fp >= FP_RESOURCE &&
 543                  ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk >= D_UNKNOWN)
 544                 rv = SS_PRIMARY_NOP;
 545
 546         else if (ns.role == R_PRIMARY && ns.disk <= D_INCONSISTENT && ns.pdsk <= D_INCONSISTENT)
 547                 rv = SS_NO_UP_TO_DATE_DISK;
 548
 549         else if (ns.conn > C_CONNECTED && ns.disk < D_INCONSISTENT)
 550                 rv = SS_NO_LOCAL_DISK;
 551
 552         else if (ns.conn > C_CONNECTED && ns.pdsk < D_INCONSISTENT)
 553                 rv = SS_NO_REMOTE_DISK;
 554
 555         else if (ns.conn > C_CONNECTED && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)
 556                 rv = SS_NO_UP_TO_DATE_DISK;
 557
 558         else if ((ns.conn == C_CONNECTED ||
 559                   ns.conn == C_WF_BITMAP_S ||
 560                   ns.conn == C_SYNC_SOURCE ||
 561                   ns.conn == C_PAUSED_SYNC_S) &&
 562                   ns.disk == D_OUTDATED)
 563                 rv = SS_CONNECTED_OUTDATES;
 564
 565         else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
 566                  (nc->verify_alg[0] == 0))
 567                 rv = SS_NO_VERIFY_ALG;
 568
 569         else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
 570                   mdev->tconn->agreed_pro_version < 88)
 571                 rv = SS_NOT_SUPPORTED;
 572
 573         else if (ns.conn >= C_CONNECTED && ns.pdsk == D_UNKNOWN)
 574                 rv = SS_CONNECTED_OUTDATES;
 575
 576         rcu_read_unlock();
 577
 578         return rv;
 579 }
 580
 581 /**
 582  * is_valid_soft_transition() - Returns an SS_ error code if the state transition is not possible
 583  * This function limits state transitions that may be declined by DRBD. I.e.
 584  * user requests (aka soft transitions).
 585  * @mdev:       DRBD device.
 586  * @ns:         new state.
 587  * @os:         old state.
 588  */
 589 static enum drbd_state_rv
 590 is_valid_soft_transition(union drbd_state os, union drbd_state ns, struct drbd_tconn *tconn)
 591 {
 592         enum drbd_state_rv rv = SS_SUCCESS;
 593
 594         if ((ns.conn == C_STARTING_SYNC_T || ns.conn == C_STARTING_SYNC_S) &&
 595             os.conn > C_CONNECTED)
 596                 rv = SS_RESYNC_RUNNING;
 597
 598         if (ns.conn == C_DISCONNECTING && os.conn == C_STANDALONE)
 599                 rv = SS_ALREADY_STANDALONE;
 600
 601         if (ns.disk > D_ATTACHING && os.disk == D_DISKLESS)
 602                 rv = SS_IS_DISKLESS;
 603
 604         if (ns.conn == C_WF_CONNECTION && os.conn < C_UNCONNECTED)
 605                 rv = SS_NO_NET_CONFIG;
 606
 607         if (ns.disk == D_OUTDATED && os.disk < D_OUTDATED && os.disk != D_ATTACHING)
 608                 rv = SS_LOWER_THAN_OUTDATED;
 609
 610         if (ns.conn == C_DISCONNECTING && os.conn == C_UNCONNECTED)
 611                 rv = SS_IN_TRANSIENT_STATE;
 612
 613         /* if (ns.conn == os.conn && ns.conn == C_WF_REPORT_PARAMS)
 614            rv = SS_IN_TRANSIENT_STATE; */
 615
 616         /* While establishing a connection only allow cstate to change.
 617            Delay/refuse role changes, detach attach etc... */
 618         if (test_bit(STATE_SENT, &tconn->flags) &&
 619             !(os.conn == C_WF_REPORT_PARAMS ||
 620               (ns.conn == C_WF_REPORT_PARAMS && os.conn == C_WF_CONNECTION)))
 621                 rv = SS_IN_TRANSIENT_STATE;
 622
 623         if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && os.conn < C_CONNECTED)
 624                 rv = SS_NEED_CONNECTION;
 625
 626         if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
 627             ns.conn != os.conn && os.conn > C_CONNECTED)
 628                 rv = SS_RESYNC_RUNNING;
 629
 630         if ((ns.conn == C_STARTING_SYNC_S || ns.conn == C_STARTING_SYNC_T) &&
 631             os.conn < C_CONNECTED)
 632                 rv = SS_NEED_CONNECTION;
 633
 634         if ((ns.conn == C_SYNC_TARGET || ns.conn == C_SYNC_SOURCE)
 635             && os.conn < C_WF_REPORT_PARAMS)
 636                 rv = SS_NEED_CONNECTION; /* No NetworkFailure -> SyncTarget etc... */
 637
 638         return rv;
 639 }
 640
 641 static enum drbd_state_rv
 642 is_valid_conn_transition(enum drbd_conns oc, enum drbd_conns nc)
 643 {
 644         /* no change -> nothing to do, at least for the connection part */
 645         if (oc == nc)
 646                 return SS_NOTHING_TO_DO;
 647
 648         /* disconnect of an unconfigured connection does not make sense */
 649         if (oc == C_STANDALONE && nc == C_DISCONNECTING)
 650                 return SS_ALREADY_STANDALONE;
 651
 652         /* from C_STANDALONE, we start with C_UNCONNECTED */
 653         if (oc == C_STANDALONE && nc != C_UNCONNECTED)
 654                 return SS_NEED_CONNECTION;
 655
 656         /* When establishing a connection we need to go through WF_REPORT_PARAMS!
 657            Necessary to do the right thing upon invalidate-remote on a disconnected resource */
 658         if (oc < C_WF_REPORT_PARAMS && nc >= C_CONNECTED)
 659                 return SS_NEED_CONNECTION;
 660
 661         /* After a network error only C_UNCONNECTED or C_DISCONNECTING may follow. */
 662         if (oc >= C_TIMEOUT && oc <= C_TEAR_DOWN && nc != C_UNCONNECTED && nc != C_DISCONNECTING)
 663                 return SS_IN_TRANSIENT_STATE;
 664
 665         /* After C_DISCONNECTING only C_STANDALONE may follow */
 666         if (oc == C_DISCONNECTING && nc != C_STANDALONE)
 667                 return SS_IN_TRANSIENT_STATE;
 668
 669         return SS_SUCCESS;
 670 }
 671
 672
 673 /**
 674  * is_valid_transition() - Returns an SS_ error code if the state transition is not possible
 675  * This limits hard state transitions. Hard state transitions are facts there are
 676  * imposed on DRBD by the environment. E.g. disk broke or network broke down.
 677  * But those hard state transitions are still not allowed to do everything.
 678  * @ns:         new state.
 679  * @os:         old state.
 680  */
 681 static enum drbd_state_rv
 682 is_valid_transition(union drbd_state os, union drbd_state ns)
 683 {
 684         enum drbd_state_rv rv;
 685
 686         rv = is_valid_conn_transition(os.conn, ns.conn);
 687
 688         /* we cannot fail (again) if we already detached */
 689         if (ns.disk == D_FAILED && os.disk == D_DISKLESS)
 690                 rv = SS_IS_DISKLESS;
 691
 692         return rv;
 693 }
 694
 695 static void print_sanitize_warnings(struct drbd_conf *mdev, enum sanitize_state_warnings warn)
 696 {
 697         static const char *msg_table[] = {
 698                 [NO_WARNING] = "",
 699                 [ABORTED_ONLINE_VERIFY] = "Online-verify aborted.",
 700                 [ABORTED_RESYNC] = "Resync aborted.",
 701                 [CONNECTION_LOST_NEGOTIATING] = "Connection lost while negotiating, no data!",
 702                 [IMPLICITLY_UPGRADED_DISK] = "Implicitly upgraded disk",
 703                 [IMPLICITLY_UPGRADED_PDSK] = "Implicitly upgraded pdsk",
 704         };
 705
 706         if (warn != NO_WARNING)
 707                 dev_warn(DEV, "%s\n", msg_table[warn]);
 708 }
 709
 710 /**
 711  * sanitize_state() - Resolves implicitly necessary additional changes to a state transition
 712  * @mdev:       DRBD device.
 713  * @os:         old state.
 714  * @ns:         new state.
 715  * @warn_sync_abort:
 716  *
 717  * When we loose connection, we have to set the state of the peers disk (pdsk)
 718  * to D_UNKNOWN. This rule and many more along those lines are in this function.
 719  */
 720 static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state ns,
 721                                        enum sanitize_state_warnings *warn)
 722 {
 723         enum drbd_fencing_p fp;
 724         enum drbd_disk_state disk_min, disk_max, pdsk_min, pdsk_max;
 725
 726         if (warn)
 727                 *warn = NO_WARNING;
 728
 729         fp = FP_DONT_CARE;
 730         if (get_ldev(mdev)) {
 731                 rcu_read_lock();
 732                 fp = rcu_dereference(mdev->ldev->disk_conf)->fencing;
 733                 rcu_read_unlock();
 734                 put_ldev(mdev);
 735         }
 736
 737         /* Implications from connection to peer and peer_isp */
 738         if (ns.conn < C_CONNECTED) {
 739                 ns.peer_isp = 0;
 740                 ns.peer = R_UNKNOWN;
 741                 if (ns.pdsk > D_UNKNOWN || ns.pdsk < D_INCONSISTENT)
 742                         ns.pdsk = D_UNKNOWN;
 743         }
 744
 745         /* Clear the aftr_isp when becoming unconfigured */
 746         if (ns.conn == C_STANDALONE && ns.disk == D_DISKLESS && ns.role == R_SECONDARY)
 747                 ns.aftr_isp = 0;
 748
 749         /* An implication of the disk states onto the connection state */
 750         /* Abort resync if a disk fails/detaches */
 751         if (ns.conn > C_CONNECTED && (ns.disk <= D_FAILED || ns.pdsk <= D_FAILED)) {
 752                 if (warn)
 753                         *warn = ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T ?
 754                                 ABORTED_ONLINE_VERIFY : ABORTED_RESYNC;
 755                 ns.conn = C_CONNECTED;
 756         }
 757
 758         /* Connection breaks down before we finished "Negotiating" */
 759         if (ns.conn < C_CONNECTED && ns.disk == D_NEGOTIATING &&
 760             get_ldev_if_state(mdev, D_NEGOTIATING)) {
 761                 if (mdev->ed_uuid == mdev->ldev->md.uuid[UI_CURRENT]) {
 762                         ns.disk = mdev->new_state_tmp.disk;
 763                         ns.pdsk = mdev->new_state_tmp.pdsk;
 764                 } else {
 765                         if (warn)
 766                                 *warn = CONNECTION_LOST_NEGOTIATING;
 767                         ns.disk = D_DISKLESS;
 768                         ns.pdsk = D_UNKNOWN;
 769                 }
 770                 put_ldev(mdev);
 771         }
 772
 773         /* D_CONSISTENT and D_OUTDATED vanish when we get connected */
 774         if (ns.conn >= C_CONNECTED && ns.conn < C_AHEAD) {
 775                 if (ns.disk == D_CONSISTENT || ns.disk == D_OUTDATED)
 776                         ns.disk = D_UP_TO_DATE;
 777                 if (ns.pdsk == D_CONSISTENT || ns.pdsk == D_OUTDATED)
 778                         ns.pdsk = D_UP_TO_DATE;
 779         }
 780
 781         /* Implications of the connection stat on the disk states */
 782         disk_min = D_DISKLESS;
 783         disk_max = D_UP_TO_DATE;
 784         pdsk_min = D_INCONSISTENT;
 785         pdsk_max = D_UNKNOWN;
 786         switch ((enum drbd_conns)ns.conn) {
 787         case C_WF_BITMAP_T:
 788         case C_PAUSED_SYNC_T:
 789         case C_STARTING_SYNC_T:
 790         case C_WF_SYNC_UUID:
 791         case C_BEHIND:
 792                 disk_min = D_INCONSISTENT;
 793                 disk_max = D_OUTDATED;
 794                 pdsk_min = D_UP_TO_DATE;
 795                 pdsk_max = D_UP_TO_DATE;
 796                 break;
 797         case C_VERIFY_S:
 798         case C_VERIFY_T:
 799                 disk_min = D_UP_TO_DATE;
 800                 disk_max = D_UP_TO_DATE;
 801                 pdsk_min = D_UP_TO_DATE;
 802                 pdsk_max = D_UP_TO_DATE;
 803                 break;
 804         case C_CONNECTED:
 805                 disk_min = D_DISKLESS;
 806                 disk_max = D_UP_TO_DATE;
 807                 pdsk_min = D_DISKLESS;
 808                 pdsk_max = D_UP_TO_DATE;
 809                 break;
 810         case C_WF_BITMAP_S:
 811         case C_PAUSED_SYNC_S:
 812         case C_STARTING_SYNC_S:
 813         case C_AHEAD:
 814                 disk_min = D_UP_TO_DATE;
 815                 disk_max = D_UP_TO_DATE;
 816                 pdsk_min = D_INCONSISTENT;
 817                 pdsk_max = D_CONSISTENT; /* D_OUTDATED would be nice. But explicit outdate necessary*/
 818                 break;
 819         case C_SYNC_TARGET:
 820                 disk_min = D_INCONSISTENT;
 821                 disk_max = D_INCONSISTENT;
 822                 pdsk_min = D_UP_TO_DATE;
 823                 pdsk_max = D_UP_TO_DATE;
 824                 break;
 825         case C_SYNC_SOURCE:
 826                 disk_min = D_UP_TO_DATE;
 827                 disk_max = D_UP_TO_DATE;
 828                 pdsk_min = D_INCONSISTENT;
 829                 pdsk_max = D_INCONSISTENT;
 830                 break;
 831         case C_STANDALONE:
 832         case C_DISCONNECTING:
 833         case C_UNCONNECTED:
 834         case C_TIMEOUT:
 835         case C_BROKEN_PIPE:
 836         case C_NETWORK_FAILURE:
 837         case C_PROTOCOL_ERROR:
 838         case C_TEAR_DOWN:
 839         case C_WF_CONNECTION:
 840         case C_WF_REPORT_PARAMS:
 841         case C_MASK:
 842                 break;
 843         }
 844         if (ns.disk > disk_max)
 845                 ns.disk = disk_max;
 846
 847         if (ns.disk < disk_min) {
 848                 if (warn)
 849                         *warn = IMPLICITLY_UPGRADED_DISK;
 850                 ns.disk = disk_min;
 851         }
 852         if (ns.pdsk > pdsk_max)
 853                 ns.pdsk = pdsk_max;
 854
 855         if (ns.pdsk < pdsk_min) {
 856                 if (warn)
 857                         *warn = IMPLICITLY_UPGRADED_PDSK;
 858                 ns.pdsk = pdsk_min;
 859         }
 860
 861         if (fp == FP_STONITH &&
 862             (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk > D_OUTDATED))
 863                 ns.susp_fen = 1; /* Suspend IO while fence-peer handler runs (peer lost) */
 864
 865         if (mdev->tconn->res_opts.on_no_data == OND_SUSPEND_IO &&
 866             (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE))
 867                 ns.susp_nod = 1; /* Suspend IO while no data available (no accessible data available) */
 868
 869         if (ns.aftr_isp || ns.peer_isp || ns.user_isp) {
 870                 if (ns.conn == C_SYNC_SOURCE)
 871                         ns.conn = C_PAUSED_SYNC_S;
 872                 if (ns.conn == C_SYNC_TARGET)
 873                         ns.conn = C_PAUSED_SYNC_T;
 874         } else {
 875                 if (ns.conn == C_PAUSED_SYNC_S)
 876                         ns.conn = C_SYNC_SOURCE;
 877                 if (ns.conn == C_PAUSED_SYNC_T)
 878                         ns.conn = C_SYNC_TARGET;
 879         }
 880
 881         return ns;
 882 }
 883
 884 void drbd_resume_al(struct drbd_conf *mdev)
 885 {
 886         if (test_and_clear_bit(AL_SUSPENDED, &mdev->flags))
 887                 dev_info(DEV, "Resumed AL updates\n");
 888 }
 889
 890 /* helper for __drbd_set_state */
 891 static void set_ov_position(struct drbd_conf *mdev, enum drbd_conns cs)
 892 {
 893         if (mdev->tconn->agreed_pro_version < 90)
 894                 mdev->ov_start_sector = 0;
 895         mdev->rs_total = drbd_bm_bits(mdev);
 896         mdev->ov_position = 0;
 897         if (cs == C_VERIFY_T) {
 898                 /* starting online verify from an arbitrary position
 899                  * does not fit well into the existing protocol.
 900                  * on C_VERIFY_T, we initialize ov_left and friends
 901                  * implicitly in receive_DataRequest once the
 902                  * first P_OV_REQUEST is received */
 903                 mdev->ov_start_sector = ~(sector_t)0;
 904         } else {
 905                 unsigned long bit = BM_SECT_TO_BIT(mdev->ov_start_sector);
 906                 if (bit >= mdev->rs_total) {
 907                         mdev->ov_start_sector =
 908                                 BM_BIT_TO_SECT(mdev->rs_total - 1);
 909                         mdev->rs_total = 1;
 910                 } else
 911                         mdev->rs_total -= bit;
 912                 mdev->ov_position = mdev->ov_start_sector;
 913         }
 914         mdev->ov_left = mdev->rs_total;
 915 }
 916
 917 /**
 918  * __drbd_set_state() - Set a new DRBD state
 919  * @mdev:       DRBD device.
 920  * @ns:         new state.
 921  * @flags:      Flags
 922  * @done:       Optional completion, that will get completed after the after_state_ch() finished
 923  *
 924  * Caller needs to hold req_lock, and global_state_lock. Do not call directly.
 925  */
 926 enum drbd_state_rv
 927 __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
 928                  enum chg_state_flags flags, struct completion *done)
 929 {
 930         union drbd_state os;
 931         enum drbd_state_rv rv = SS_SUCCESS;
 932         enum sanitize_state_warnings ssw;
 933         struct after_state_chg_work *ascw;
 934
 935         os = drbd_read_state(mdev);
 936
 937         ns = sanitize_state(mdev, ns, &ssw);
 938         if (ns.i == os.i)
 939                 return SS_NOTHING_TO_DO;
 940
 941         rv = is_valid_transition(os, ns);
 942         if (rv < SS_SUCCESS)
 943                 return rv;
 944
 945         if (!(flags & CS_HARD)) {
 946                 /*  pre-state-change checks ; only look at ns  */
 947                 /* See drbd_state_sw_errors in drbd_strings.c */
 948
 949                 rv = is_valid_state(mdev, ns);
 950                 if (rv < SS_SUCCESS) {
 951                         /* If the old state was illegal as well, then let
 952                            this happen...*/
 953
 954                         if (is_valid_state(mdev, os) == rv)
 955                                 rv = is_valid_soft_transition(os, ns, mdev->tconn);
 956                 } else
 957                         rv = is_valid_soft_transition(os, ns, mdev->tconn);
 958         }
 959
 960         if (rv < SS_SUCCESS) {
 961                 if (flags & CS_VERBOSE)
 962                         print_st_err(mdev, os, ns, rv);
 963                 return rv;
 964         }
 965
 966         print_sanitize_warnings(mdev, ssw);
 967
 968         drbd_pr_state_change(mdev, os, ns, flags);
 969
 970         /* Display changes to the susp* flags that where caused by the call to
 971            sanitize_state(). Only display it here if we where not called from
 972            _conn_request_state() */
 973         if (!(flags & CS_DC_SUSP))
 974                 conn_pr_state_change(mdev->tconn, os, ns, (flags & ~CS_DC_MASK) | CS_DC_SUSP);
 975
 976         /* if we are going -> D_FAILED or D_DISKLESS, grab one extra reference
 977          * on the ldev here, to be sure the transition -> D_DISKLESS resp.
 978          * drbd_ldev_destroy() won't happen before our corresponding
 979          * after_state_ch works run, where we put_ldev again. */
 980         if ((os.disk != D_FAILED && ns.disk == D_FAILED) ||
 981             (os.disk != D_DISKLESS && ns.disk == D_DISKLESS))
 982                 atomic_inc(&mdev->local_cnt);
 983
 984         mdev->state.i = ns.i;
 985         mdev->tconn->susp = ns.susp;
 986         mdev->tconn->susp_nod = ns.susp_nod;
 987         mdev->tconn->susp_fen = ns.susp_fen;
 988
 989         if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
 990                 drbd_print_uuids(mdev, "attached to UUIDs");
 991
 992         /* Wake up role changes, that were delayed because of connection establishing */
 993         if (os.conn == C_WF_REPORT_PARAMS && ns.conn != C_WF_REPORT_PARAMS &&
 994             no_peer_wf_report_params(mdev->tconn))
 995                 clear_bit(STATE_SENT, &mdev->tconn->flags);
 996
 997         wake_up(&mdev->misc_wait);
 998         wake_up(&mdev->state_wait);
 999         wake_up(&mdev->tconn->ping_wait);
1000
1001         /* Aborted verify run, or we reached the stop sector.
1002          * Log the last position, unless end-of-device. */
1003         if ((os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) &&
1004             ns.conn <= C_CONNECTED) {
1005                 mdev->ov_start_sector =
1006                         BM_BIT_TO_SECT(drbd_bm_bits(mdev) - mdev->ov_left);
1007                 if (mdev->ov_left)
1008                         dev_info(DEV, "Online Verify reached sector %llu\n",
1009                                 (unsigned long long)mdev->ov_start_sector);
1010         }
1011
1012         if ((os.conn == C_PAUSED_SYNC_T || os.conn == C_PAUSED_SYNC_S) &&
1013             (ns.conn == C_SYNC_TARGET  || ns.conn == C_SYNC_SOURCE)) {
1014                 dev_info(DEV, "Syncer continues.\n");
1015                 mdev->rs_paused += (long)jiffies
1016                                   -(long)mdev->rs_mark_time[mdev->rs_last_mark];
1017                 if (ns.conn == C_SYNC_TARGET)
1018                         mod_timer(&mdev->resync_timer, jiffies);
1019         }
1020
1021         if ((os.conn == C_SYNC_TARGET  || os.conn == C_SYNC_SOURCE) &&
1022             (ns.conn == C_PAUSED_SYNC_T || ns.conn == C_PAUSED_SYNC_S)) {
1023                 dev_info(DEV, "Resync suspended\n");
1024                 mdev->rs_mark_time[mdev->rs_last_mark] = jiffies;
1025         }
1026
1027         if (os.conn == C_CONNECTED &&
1028             (ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T)) {
1029                 unsigned long now = jiffies;
1030                 int i;
1031
1032                 set_ov_position(mdev, ns.conn);
1033                 mdev->rs_start = now;
1034                 mdev->rs_last_events = 0;
1035                 mdev->rs_last_sect_ev = 0;
1036                 mdev->ov_last_oos_size = 0;
1037                 mdev->ov_last_oos_start = 0;
1038
1039                 for (i = 0; i < DRBD_SYNC_MARKS; i++) {
1040                         mdev->rs_mark_left[i] = mdev->ov_left;
1041                         mdev->rs_mark_time[i] = now;
1042                 }
1043
1044                 drbd_rs_controller_reset(mdev);
1045
1046                 if (ns.conn == C_VERIFY_S) {
1047                         dev_info(DEV, "Starting Online Verify from sector %llu\n",
1048                                         (unsigned long long)mdev->ov_position);
1049                         mod_timer(&mdev->resync_timer, jiffies);
1050                 }
1051         }
1052
1053         if (get_ldev(mdev)) {
1054                 u32 mdf = mdev->ldev->md.flags & ~(MDF_CONSISTENT|MDF_PRIMARY_IND|
1055                                                  MDF_CONNECTED_IND|MDF_WAS_UP_TO_DATE|
1056                                                  MDF_PEER_OUT_DATED|MDF_CRASHED_PRIMARY);
1057
1058                 mdf &= ~MDF_AL_CLEAN;
1059                 if (test_bit(CRASHED_PRIMARY, &mdev->flags))
1060                         mdf |= MDF_CRASHED_PRIMARY;
1061                 if (mdev->state.role == R_PRIMARY ||
1062                     (mdev->state.pdsk < D_INCONSISTENT && mdev->state.peer == R_PRIMARY))
1063                         mdf |= MDF_PRIMARY_IND;
1064                 if (mdev->state.conn > C_WF_REPORT_PARAMS)
1065                         mdf |= MDF_CONNECTED_IND;
1066                 if (mdev->state.disk > D_INCONSISTENT)
1067                         mdf |= MDF_CONSISTENT;
1068                 if (mdev->state.disk > D_OUTDATED)
1069                         mdf |= MDF_WAS_UP_TO_DATE;
1070                 if (mdev->state.pdsk <= D_OUTDATED && mdev->state.pdsk >= D_INCONSISTENT)
1071                         mdf |= MDF_PEER_OUT_DATED;
1072                 if (mdf != mdev->ldev->md.flags) {
1073                         mdev->ldev->md.flags = mdf;
1074                         drbd_md_mark_dirty(mdev);
1075                 }
1076                 if (os.disk < D_CONSISTENT && ns.disk >= D_CONSISTENT)
1077                         drbd_set_ed_uuid(mdev, mdev->ldev->md.uuid[UI_CURRENT]);
1078                 put_ldev(mdev);
1079         }
1080
1081         /* Peer was forced D_UP_TO_DATE & R_PRIMARY, consider to resync */
1082         if (os.disk == D_INCONSISTENT && os.pdsk == D_INCONSISTENT &&
1083             os.peer == R_SECONDARY && ns.peer == R_PRIMARY)
1084                 set_bit(CONSIDER_RESYNC, &mdev->flags);
1085
1086         /* Receiver should clean up itself */
1087         if (os.conn != C_DISCONNECTING && ns.conn == C_DISCONNECTING)
1088                 drbd_thread_stop_nowait(&mdev->tconn->receiver);
1089
1090         /* Now the receiver finished cleaning up itself, it should die */
1091         if (os.conn != C_STANDALONE && ns.conn == C_STANDALONE)
1092                 drbd_thread_stop_nowait(&mdev->tconn->receiver);
1093
1094         /* Upon network failure, we need to restart the receiver. */
1095         if (os.conn > C_WF_CONNECTION &&
1096             ns.conn <= C_TEAR_DOWN && ns.conn >= C_TIMEOUT)
1097                 drbd_thread_restart_nowait(&mdev->tconn->receiver);
1098
1099         /* Resume AL writing if we get a connection */
1100         if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED)
1101                 drbd_resume_al(mdev);
1102
1103         /* remember last attach time so request_timer_fn() won't
1104          * kill newly established sessions while we are still trying to thaw
1105          * previously frozen IO */
1106         if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
1107             ns.disk > D_NEGOTIATING)
1108                 mdev->last_reattach_jif = jiffies;
1109
1110         ascw = kmalloc(sizeof(*ascw), GFP_ATOMIC);
1111         if (ascw) {
1112                 ascw->os = os;
1113                 ascw->ns = ns;
1114                 ascw->flags = flags;
1115                 ascw->w.cb = w_after_state_ch;
1116                 ascw->w.mdev = mdev;
1117                 ascw->done = done;
1118                 drbd_queue_work(&mdev->tconn->sender_work, &ascw->w);
1119         } else {
1120                 dev_err(DEV, "Could not kmalloc an ascw\n");
1121         }
1122
1123         return rv;
1124 }
1125
1126 static int w_after_state_ch(struct drbd_work *w, int unused)
1127 {
1128         struct after_state_chg_work *ascw =
1129                 container_of(w, struct after_state_chg_work, w);
1130         struct drbd_conf *mdev = w->mdev;
1131
1132         after_state_ch(mdev, ascw->os, ascw->ns, ascw->flags);
1133         if (ascw->flags & CS_WAIT_COMPLETE) {
1134                 D_ASSERT(ascw->done != NULL);
1135                 complete(ascw->done);
1136         }
1137         kfree(ascw);
1138
1139         return 0;
1140 }
1141
1142 static void abw_start_sync(struct drbd_conf *mdev, int rv)
1143 {
1144         if (rv) {
1145                 dev_err(DEV, "Writing the bitmap failed not starting resync.\n");
1146                 _drbd_request_state(mdev, NS(conn, C_CONNECTED), CS_VERBOSE);
1147                 return;
1148         }
1149
1150         switch (mdev->state.conn) {
1151         case C_STARTING_SYNC_T:
1152                 _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
1153                 break;
1154         case C_STARTING_SYNC_S:
1155                 drbd_start_resync(mdev, C_SYNC_SOURCE);
1156                 break;
1157         }
1158 }
1159
1160 int drbd_bitmap_io_from_worker(struct drbd_conf *mdev,
1161                 int (*io_fn)(struct drbd_conf *),
1162                 char *why, enum bm_flag flags)
1163 {
1164         int rv;
1165
1166         D_ASSERT(current == mdev->tconn->worker.task);
1167
1168         /* open coded non-blocking drbd_suspend_io(mdev); */
1169         set_bit(SUSPEND_IO, &mdev->flags);
1170
1171         drbd_bm_lock(mdev, why, flags);
1172         rv = io_fn(mdev);
1173         drbd_bm_unlock(mdev);
1174
1175         drbd_resume_io(mdev);
1176
1177         return rv;
1178 }
1179
1180 /**
1181  * after_state_ch() - Perform after state change actions that may sleep
1182  * @mdev:       DRBD device.
1183  * @os:         old state.
1184  * @ns:         new state.
1185  * @flags:      Flags
1186  */
1187 static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
1188                            union drbd_state ns, enum chg_state_flags flags)
1189 {
1190         struct sib_info sib;
1191
1192         sib.sib_reason = SIB_STATE_CHANGE;
1193         sib.os = os;
1194         sib.ns = ns;
1195
1196         if (os.conn != C_CONNECTED && ns.conn == C_CONNECTED) {
1197                 clear_bit(CRASHED_PRIMARY, &mdev->flags);
1198                 if (mdev->p_uuid)
1199                         mdev->p_uuid[UI_FLAGS] &= ~((u64)2);
1200         }
1201
1202         /* Inform userspace about the change... */
1203         drbd_bcast_event(mdev, &sib);
1204
1205         if (!(os.role == R_PRIMARY && os.disk < D_UP_TO_DATE && os.pdsk < D_UP_TO_DATE) &&
1206             (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE))
1207                 drbd_khelper(mdev, "pri-on-incon-degr");
1208
1209         /* Here we have the actions that are performed after a
1210            state change. This function might sleep */
1211
1212         if (ns.susp_nod) {
1213                 struct drbd_tconn *tconn = mdev->tconn;
1214                 enum drbd_req_event what = NOTHING;
1215
1216                 spin_lock_irq(&tconn->req_lock);
1217                 if (os.conn < C_CONNECTED && conn_lowest_conn(tconn) >= C_CONNECTED)
1218                         what = RESEND;
1219
1220                 if ((os.disk == D_ATTACHING || os.disk == D_NEGOTIATING) &&
1221                     conn_lowest_disk(tconn) > D_NEGOTIATING)
1222                         what = RESTART_FROZEN_DISK_IO;
1223
1224                 if (tconn->susp_nod && what != NOTHING) {
1225                         _tl_restart(tconn, what);
1226                         _conn_request_state(tconn,
1227                                             (union drbd_state) { { .susp_nod = 1 } },
1228                                             (union drbd_state) { { .susp_nod = 0 } },
1229                                             CS_VERBOSE);
1230                 }
1231                 spin_unlock_irq(&tconn->req_lock);
1232         }
1233
1234         if (ns.susp_fen) {
1235                 struct drbd_tconn *tconn = mdev->tconn;
1236
1237                 spin_lock_irq(&tconn->req_lock);
1238                 if (tconn->susp_fen && conn_lowest_conn(tconn) >= C_CONNECTED) {
1239                         /* case2: The connection was established again: */
1240                         struct drbd_conf *odev;
1241                         int vnr;
1242
1243                         rcu_read_lock();
1244                         idr_for_each_entry(&tconn->volumes, odev, vnr)
1245                                 clear_bit(NEW_CUR_UUID, &odev->flags);
1246                         rcu_read_unlock();
1247                         _tl_restart(tconn, RESEND);
1248                         _conn_request_state(tconn,
1249                                             (union drbd_state) { { .susp_fen = 1 } },
1250                                             (union drbd_state) { { .susp_fen = 0 } },
1251                                             CS_VERBOSE);
1252                 }
1253                 spin_unlock_irq(&tconn->req_lock);
1254         }
1255
1256         /* Became sync source.  With protocol >= 96, we still need to send out
1257          * the sync uuid now. Need to do that before any drbd_send_state, or
1258          * the other side may go "paused sync" before receiving the sync uuids,
1259          * which is unexpected. */
1260         if ((os.conn != C_SYNC_SOURCE && os.conn != C_PAUSED_SYNC_S) &&
1261             (ns.conn == C_SYNC_SOURCE || ns.conn == C_PAUSED_SYNC_S) &&
1262             mdev->tconn->agreed_pro_version >= 96 && get_ldev(mdev)) {
1263                 drbd_gen_and_send_sync_uuid(mdev);
1264                 put_ldev(mdev);
1265         }
1266
1267         /* Do not change the order of the if above and the two below... */
1268         if (os.pdsk == D_DISKLESS &&
1269             ns.pdsk > D_DISKLESS && ns.pdsk != D_UNKNOWN) {      /* attach on the peer */
1270                 /* we probably will start a resync soon.
1271                  * make sure those things are properly reset. */
1272                 mdev->rs_total = 0;
1273                 mdev->rs_failed = 0;
1274                 atomic_set(&mdev->rs_pending_cnt, 0);
1275                 drbd_rs_cancel_all(mdev);
1276
1277                 drbd_send_uuids(mdev);
1278                 drbd_send_state(mdev, ns);
1279         }
1280         /* No point in queuing send_bitmap if we don't have a connection
1281          * anymore, so check also the _current_ state, not only the new state
1282          * at the time this work was queued. */
1283         if (os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S &&
1284             mdev->state.conn == C_WF_BITMAP_S)
1285                 drbd_queue_bitmap_io(mdev, &drbd_send_bitmap, NULL,
1286                                 "send_bitmap (WFBitMapS)",
1287                                 BM_LOCKED_TEST_ALLOWED);
1288
1289         /* Lost contact to peer's copy of the data */
1290         if ((os.pdsk >= D_INCONSISTENT &&
1291              os.pdsk != D_UNKNOWN &&
1292              os.pdsk != D_OUTDATED)
1293         &&  (ns.pdsk < D_INCONSISTENT ||
1294              ns.pdsk == D_UNKNOWN ||
1295              ns.pdsk == D_OUTDATED)) {
1296                 if (get_ldev(mdev)) {
1297                         if ((ns.role == R_PRIMARY || ns.peer == R_PRIMARY) &&
1298                             mdev->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
1299                                 if (drbd_suspended(mdev)) {
1300                                         set_bit(NEW_CUR_UUID, &mdev->flags);
1301                                 } else {
1302                                         drbd_uuid_new_current(mdev);
1303                                         drbd_send_uuids(mdev);
1304                                 }
1305                         }
1306                         put_ldev(mdev);
1307                 }
1308         }
1309
1310         if (ns.pdsk < D_INCONSISTENT && get_ldev(mdev)) {
1311                 if (os.peer == R_SECONDARY && ns.peer == R_PRIMARY &&
1312                     mdev->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
1313                         drbd_uuid_new_current(mdev);
1314                         drbd_send_uuids(mdev);
1315                 }
1316                 /* D_DISKLESS Peer becomes secondary */
1317                 if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY)
1318                         /* We may still be Primary ourselves.
1319                          * No harm done if the bitmap still changes,
1320                          * redirtied pages will follow later. */
1321                         drbd_bitmap_io_from_worker(mdev, &drbd_bm_write,
1322                                 "demote diskless peer", BM_LOCKED_SET_ALLOWED);
1323                 put_ldev(mdev);
1324         }
1325
1326         /* Write out all changed bits on demote.
1327          * Though, no need to da that just yet
1328          * if there is a resync going on still */
1329         if (os.role == R_PRIMARY && ns.role == R_SECONDARY &&
1330                 mdev->state.conn <= C_CONNECTED && get_ldev(mdev)) {
1331                 /* No changes to the bitmap expected this time, so assert that,
1332                  * even though no harm was done if it did change. */
1333                 drbd_bitmap_io_from_worker(mdev, &drbd_bm_write,
1334                                 "demote", BM_LOCKED_TEST_ALLOWED);
1335                 put_ldev(mdev);
1336         }
1337
1338         /* Last part of the attaching process ... */
1339         if (ns.conn >= C_CONNECTED &&
1340             os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) {
1341                 drbd_send_sizes(mdev, 0, 0);  /* to start sync... */
1342                 drbd_send_uuids(mdev);
1343                 drbd_send_state(mdev, ns);
1344         }
1345
1346         /* We want to pause/continue resync, tell peer. */
1347         if (ns.conn >= C_CONNECTED &&
1348              ((os.aftr_isp != ns.aftr_isp) ||
1349               (os.user_isp != ns.user_isp)))
1350                 drbd_send_state(mdev, ns);
1351
1352         /* In case one of the isp bits got set, suspend other devices. */
1353         if ((!os.aftr_isp && !os.peer_isp && !os.user_isp) &&
1354             (ns.aftr_isp || ns.peer_isp || ns.user_isp))
1355                 suspend_other_sg(mdev);
1356
1357         /* Make sure the peer gets informed about eventual state
1358            changes (ISP bits) while we were in WFReportParams. */
1359         if (os.conn == C_WF_REPORT_PARAMS && ns.conn >= C_CONNECTED)
1360                 drbd_send_state(mdev, ns);
1361
1362         if (os.conn != C_AHEAD && ns.conn == C_AHEAD)
1363                 drbd_send_state(mdev, ns);
1364
1365         /* We are in the progress to start a full sync... */
1366         if ((os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
1367             (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S))
1368                 /* no other bitmap changes expected during this phase */
1369                 drbd_queue_bitmap_io(mdev,
1370                         &drbd_bmio_set_n_write, &abw_start_sync,
1371                         "set_n_write from StartingSync", BM_LOCKED_TEST_ALLOWED);
1372
1373         /* We are invalidating our self... */
1374         if (os.conn < C_CONNECTED && ns.conn < C_CONNECTED &&
1375             os.disk > D_INCONSISTENT && ns.disk == D_INCONSISTENT)
1376                 /* other bitmap operation expected during this phase */
1377                 drbd_queue_bitmap_io(mdev, &drbd_bmio_set_n_write, NULL,
1378                         "set_n_write from invalidate", BM_LOCKED_MASK);
1379
1380         /* first half of local IO error, failure to attach,
1381          * or administrative detach */
1382         if (os.disk != D_FAILED && ns.disk == D_FAILED) {
1383                 enum drbd_io_error_p eh = EP_PASS_ON;
1384                 int was_io_error = 0;
1385                 /* corresponding get_ldev was in __drbd_set_state, to serialize
1386                  * our cleanup here with the transition to D_DISKLESS.
1387                  * But is is still not save to dreference ldev here, since
1388                  * we might come from an failed Attach before ldev was set. */
1389                 if (mdev->ldev) {
1390                         rcu_read_lock();
1391                         eh = rcu_dereference(mdev->ldev->disk_conf)->on_io_error;
1392                         rcu_read_unlock();
1393
1394                         was_io_error = test_and_clear_bit(WAS_IO_ERROR, &mdev->flags);
1395
1396                         if (was_io_error && eh == EP_CALL_HELPER)
1397                                 drbd_khelper(mdev, "local-io-error");
1398
1399                         /* Immediately allow completion of all application IO,
1400                          * that waits for completion from the local disk,
1401                          * if this was a force-detach due to disk_timeout
1402                          * or administrator request (drbdsetup detach --force).
1403                          * Do NOT abort otherwise.
1404                          * Aborting local requests may cause serious problems,
1405                          * if requests are completed to upper layers already,
1406                          * and then later the already submitted local bio completes.
1407                          * This can cause DMA into former bio pages that meanwhile
1408                          * have been re-used for other things.
1409                          * So aborting local requests may cause crashes,
1410                          * or even worse, silent data corruption.
1411                          */
1412                         if (test_and_clear_bit(FORCE_DETACH, &mdev->flags))
1413                                 tl_abort_disk_io(mdev);
1414
1415                         /* current state still has to be D_FAILED,
1416                          * there is only one way out: to D_DISKLESS,
1417                          * and that may only happen after our put_ldev below. */
1418                         if (mdev->state.disk != D_FAILED)
1419                                 dev_err(DEV,
1420                                         "ASSERT FAILED: disk is %s during detach\n",
1421                                         drbd_disk_str(mdev->state.disk));
1422
1423                         if (ns.conn >= C_CONNECTED)
1424                                 drbd_send_state(mdev, ns);
1425
1426                         drbd_rs_cancel_all(mdev);
1427
1428                         /* In case we want to get something to stable storage still,
1429                          * this may be the last chance.
1430                          * Following put_ldev may transition to D_DISKLESS. */
1431                         drbd_md_sync(mdev);
1432                 }
1433                 put_ldev(mdev);
1434         }
1435
1436         /* second half of local IO error, failure to attach,
1437          * or administrative detach,
1438          * after local_cnt references have reached zero again */
1439         if (os.disk != D_DISKLESS && ns.disk == D_DISKLESS) {
1440                 /* We must still be diskless,
1441                  * re-attach has to be serialized with this! */
1442                 if (mdev->state.disk != D_DISKLESS)
1443                         dev_err(DEV,
1444                                 "ASSERT FAILED: disk is %s while going diskless\n",
1445                                 drbd_disk_str(mdev->state.disk));
1446
1447                 if (ns.conn >= C_CONNECTED)
1448                         drbd_send_state(mdev, ns);
1449                 /* corresponding get_ldev in __drbd_set_state
1450                  * this may finally trigger drbd_ldev_destroy. */
1451                 put_ldev(mdev);
1452         }
1453
1454         /* Notify peer that I had a local IO error, and did not detached.. */
1455         if (os.disk == D_UP_TO_DATE && ns.disk == D_INCONSISTENT && ns.conn >= C_CONNECTED)
1456                 drbd_send_state(mdev, ns);
1457
1458         /* Disks got bigger while they were detached */
1459         if (ns.disk > D_NEGOTIATING && ns.pdsk > D_NEGOTIATING &&
1460             test_and_clear_bit(RESYNC_AFTER_NEG, &mdev->flags)) {
1461                 if (ns.conn == C_CONNECTED)
1462                         resync_after_online_grow(mdev);
1463         }
1464
1465         /* A resync finished or aborted, wake paused devices... */
1466         if ((os.conn > C_CONNECTED && ns.conn <= C_CONNECTED) ||
1467             (os.peer_isp && !ns.peer_isp) ||
1468             (os.user_isp && !ns.user_isp))
1469                 resume_next_sg(mdev);
1470
1471         /* sync target done with resync.  Explicitly notify peer, even though
1472          * it should (at least for non-empty resyncs) already know itself. */
1473         if (os.disk < D_UP_TO_DATE && os.conn >= C_SYNC_SOURCE && ns.conn == C_CONNECTED)
1474                 drbd_send_state(mdev, ns);
1475
1476         /* Verify finished, or reached stop sector.  Peer did not know about
1477          * the stop sector, and we may even have changed the stop sector during
1478          * verify to interrupt/stop early.  Send the new state. */
1479         if (os.conn == C_VERIFY_S && ns.conn == C_CONNECTED
1480         && verify_can_do_stop_sector(mdev))
1481                 drbd_send_state(mdev, ns);
1482
1483         /* This triggers bitmap writeout of potentially still unwritten pages
1484          * if the resync finished cleanly, or aborted because of peer disk
1485          * failure, or because of connection loss.
1486          * For resync aborted because of local disk failure, we cannot do
1487          * any bitmap writeout anymore.
1488          * No harm done if some bits change during this phase.
1489          */
1490         if (os.conn > C_CONNECTED && ns.conn <= C_CONNECTED && get_ldev(mdev)) {
1491                 drbd_queue_bitmap_io(mdev, &drbd_bm_write_copy_pages, NULL,
1492                         "write from resync_finished", BM_LOCKED_CHANGE_ALLOWED);
1493                 put_ldev(mdev);
1494         }
1495
1496         if (ns.disk == D_DISKLESS &&
1497             ns.conn == C_STANDALONE &&
1498             ns.role == R_SECONDARY) {
1499                 if (os.aftr_isp != ns.aftr_isp)
1500                         resume_next_sg(mdev);
1501         }
1502
1503         drbd_md_sync(mdev);
1504 }
1505
1506 struct after_conn_state_chg_work {
1507         struct drbd_work w;
1508         enum drbd_conns oc;
1509         union drbd_state ns_min;
1510         union drbd_state ns_max; /* new, max state, over all mdevs */
1511         enum chg_state_flags flags;
1512 };
1513
1514 static int w_after_conn_state_ch(struct drbd_work *w, int unused)
1515 {
1516         struct after_conn_state_chg_work *acscw =
1517                 container_of(w, struct after_conn_state_chg_work, w);
1518         struct drbd_tconn *tconn = w->tconn;
1519         enum drbd_conns oc = acscw->oc;
1520         union drbd_state ns_max = acscw->ns_max;
1521         struct drbd_conf *mdev;
1522         int vnr;
1523
1524         kfree(acscw);
1525
1526         /* Upon network configuration, we need to start the receiver */
1527         if (oc == C_STANDALONE && ns_max.conn == C_UNCONNECTED)
1528                 drbd_thread_start(&tconn->receiver);
1529
1530         if (oc == C_DISCONNECTING && ns_max.conn == C_STANDALONE) {
1531                 struct net_conf *old_conf;
1532
1533                 mutex_lock(&tconn->conf_update);
1534                 old_conf = tconn->net_conf;
1535                 tconn->my_addr_len = 0;
1536                 tconn->peer_addr_len = 0;
1537                 rcu_assign_pointer(tconn->net_conf, NULL);
1538                 conn_free_crypto(tconn);
1539                 mutex_unlock(&tconn->conf_update);
1540
1541                 synchronize_rcu();
1542                 kfree(old_conf);
1543         }
1544
1545         if (ns_max.susp_fen) {
1546                 /* case1: The outdate peer handler is successful: */
1547                 if (ns_max.pdsk <= D_OUTDATED) {
1548                         rcu_read_lock();
1549                         idr_for_each_entry(&tconn->volumes, mdev, vnr) {
1550                                 if (test_bit(NEW_CUR_UUID, &mdev->flags)) {
1551                                         drbd_uuid_new_current(mdev);
1552                                         clear_bit(NEW_CUR_UUID, &mdev->flags);
1553                                 }
1554                         }
1555                         rcu_read_unlock();
1556                         spin_lock_irq(&tconn->req_lock);
1557                         _tl_restart(tconn, CONNECTION_LOST_WHILE_PENDING);
1558                         _conn_request_state(tconn,
1559                                             (union drbd_state) { { .susp_fen = 1 } },
1560                                             (union drbd_state) { { .susp_fen = 0 } },
1561                                             CS_VERBOSE);
1562                         spin_unlock_irq(&tconn->req_lock);
1563                 }
1564         }
1565         kref_put(&tconn->kref, &conn_destroy);
1566
1567         conn_md_sync(tconn);
1568
1569         return 0;
1570 }
1571
1572 void conn_old_common_state(struct drbd_tconn *tconn, union drbd_state *pcs, enum chg_state_flags *pf)
1573 {
1574         enum chg_state_flags flags = ~0;
1575         struct drbd_conf *mdev;
1576         int vnr, first_vol = 1;
1577         union drbd_dev_state os, cs = {
1578                 { .role = R_SECONDARY,
1579                   .peer = R_UNKNOWN,
1580                   .conn = tconn->cstate,
1581                   .disk = D_DISKLESS,
1582                   .pdsk = D_UNKNOWN,
1583                 } };
1584
1585         rcu_read_lock();
1586         idr_for_each_entry(&tconn->volumes, mdev, vnr) {
1587                 os = mdev->state;
1588
1589                 if (first_vol) {
1590                         cs = os;
1591                         first_vol = 0;
1592                         continue;
1593                 }
1594
1595                 if (cs.role != os.role)
1596                         flags &= ~CS_DC_ROLE;
1597
1598                 if (cs.peer != os.peer)
1599                         flags &= ~CS_DC_PEER;
1600
1601                 if (cs.conn != os.conn)
1602                         flags &= ~CS_DC_CONN;
1603
1604                 if (cs.disk != os.disk)
1605                         flags &= ~CS_DC_DISK;
1606
1607                 if (cs.pdsk != os.pdsk)
1608                         flags &= ~CS_DC_PDSK;
1609         }
1610         rcu_read_unlock();
1611
1612         *pf |= CS_DC_MASK;
1613         *pf &= flags;
1614         (*pcs).i = cs.i;
1615 }
1616
1617 static enum drbd_state_rv
1618 conn_is_valid_transition(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val,
1619                          enum chg_state_flags flags)
1620 {
1621         enum drbd_state_rv rv = SS_SUCCESS;
1622         union drbd_state ns, os;
1623         struct drbd_conf *mdev;
1624         int vnr;
1625
1626         rcu_read_lock();
1627         idr_for_each_entry(&tconn->volumes, mdev, vnr) {
1628                 os = drbd_read_state(mdev);
1629                 ns = sanitize_state(mdev, apply_mask_val(os, mask, val), NULL);
1630
1631                 if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
1632                         ns.disk = os.disk;
1633
1634                 if (ns.i == os.i)
1635                         continue;
1636
1637                 rv = is_valid_transition(os, ns);
1638                 if (rv < SS_SUCCESS)
1639                         break;
1640
1641                 if (!(flags & CS_HARD)) {
1642                         rv = is_valid_state(mdev, ns);
1643                         if (rv < SS_SUCCESS) {
1644                                 if (is_valid_state(mdev, os) == rv)
1645                                         rv = is_valid_soft_transition(os, ns, tconn);
1646                         } else
1647                                 rv = is_valid_soft_transition(os, ns, tconn);
1648                 }
1649                 if (rv < SS_SUCCESS)
1650                         break;
1651         }
1652         rcu_read_unlock();
1653
1654         if (rv < SS_SUCCESS && flags & CS_VERBOSE)
1655                 print_st_err(mdev, os, ns, rv);
1656
1657         return rv;
1658 }
1659
1660 void
1661 conn_set_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val,
1662                union drbd_state *pns_min, union drbd_state *pns_max, enum chg_state_flags flags)
1663 {
1664         union drbd_state ns, os, ns_max = { };
1665         union drbd_state ns_min = {
1666                 { .role = R_MASK,
1667                   .peer = R_MASK,
1668                   .conn = val.conn,
1669                   .disk = D_MASK,
1670                   .pdsk = D_MASK
1671                 } };
1672         struct drbd_conf *mdev;
1673         enum drbd_state_rv rv;
1674         int vnr, number_of_volumes = 0;
1675
1676         if (mask.conn == C_MASK) {
1677                 /* remember last connect time so request_timer_fn() won't
1678                  * kill newly established sessions while we are still trying to thaw
1679                  * previously frozen IO */
1680                 if (tconn->cstate != C_WF_REPORT_PARAMS && val.conn == C_WF_REPORT_PARAMS)
1681                         tconn->last_reconnect_jif = jiffies;
1682
1683                 tconn->cstate = val.conn;
1684         }
1685
1686         rcu_read_lock();
1687         idr_for_each_entry(&tconn->volumes, mdev, vnr) {
1688                 number_of_volumes++;
1689                 os = drbd_read_state(mdev);
1690                 ns = apply_mask_val(os, mask, val);
1691                 ns = sanitize_state(mdev, ns, NULL);
1692
1693                 if (flags & CS_IGN_OUTD_FAIL && ns.disk == D_OUTDATED && os.disk < D_OUTDATED)
1694                         ns.disk = os.disk;
1695
1696                 rv = __drbd_set_state(mdev, ns, flags, NULL);
1697                 if (rv < SS_SUCCESS)
1698                         BUG();
1699
1700                 ns.i = mdev->state.i;
1701                 ns_max.role = max_role(ns.role, ns_max.role);
1702                 ns_max.peer = max_role(ns.peer, ns_max.peer);
1703                 ns_max.conn = max_t(enum drbd_conns, ns.conn, ns_max.conn);
1704                 ns_max.disk = max_t(enum drbd_disk_state, ns.disk, ns_max.disk);
1705                 ns_max.pdsk = max_t(enum drbd_disk_state, ns.pdsk, ns_max.pdsk);
1706
1707                 ns_min.role = min_role(ns.role, ns_min.role);
1708                 ns_min.peer = min_role(ns.peer, ns_min.peer);
1709                 ns_min.conn = min_t(enum drbd_conns, ns.conn, ns_min.conn);
1710                 ns_min.disk = min_t(enum drbd_disk_state, ns.disk, ns_min.disk);
1711                 ns_min.pdsk = min_t(enum drbd_disk_state, ns.pdsk, ns_min.pdsk);
1712         }
1713         rcu_read_unlock();
1714
1715         if (number_of_volumes == 0) {
1716                 ns_min = ns_max = (union drbd_state) { {
1717                                 .role = R_SECONDARY,
1718                                 .peer = R_UNKNOWN,
1719                                 .conn = val.conn,
1720                                 .disk = D_DISKLESS,
1721                                 .pdsk = D_UNKNOWN
1722                         } };
1723         }
1724
1725         ns_min.susp = ns_max.susp = tconn->susp;
1726         ns_min.susp_nod = ns_max.susp_nod = tconn->susp_nod;
1727         ns_min.susp_fen = ns_max.susp_fen = tconn->susp_fen;
1728
1729         *pns_min = ns_min;
1730         *pns_max = ns_max;
1731 }
1732
1733 static enum drbd_state_rv
1734 _conn_rq_cond(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val)
1735 {
1736         enum drbd_state_rv rv;
1737
1738         if (test_and_clear_bit(CONN_WD_ST_CHG_OKAY, &tconn->flags))
1739                 return SS_CW_SUCCESS;
1740
1741         if (test_and_clear_bit(CONN_WD_ST_CHG_FAIL, &tconn->flags))
1742                 return SS_CW_FAILED_BY_PEER;
1743
1744         rv = tconn->cstate != C_WF_REPORT_PARAMS ? SS_CW_NO_NEED : SS_UNKNOWN_ERROR;
1745
1746         if (rv == SS_UNKNOWN_ERROR)
1747                 rv = conn_is_valid_transition(tconn, mask, val, 0);
1748
1749         if (rv == SS_SUCCESS)
1750                 rv = SS_UNKNOWN_ERROR; /* cont waiting, otherwise fail. */
1751
1752         return rv;
1753 }
1754
1755 enum drbd_state_rv
1756 _conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val,
1757                     enum chg_state_flags flags)
1758 {
1759         enum drbd_state_rv rv = SS_SUCCESS;
1760         struct after_conn_state_chg_work *acscw;
1761         enum drbd_conns oc = tconn->cstate;
1762         union drbd_state ns_max, ns_min, os;
1763         bool have_mutex = false;
1764
1765         if (mask.conn) {
1766                 rv = is_valid_conn_transition(oc, val.conn);
1767                 if (rv < SS_SUCCESS)
1768                         goto abort;
1769         }
1770
1771         rv = conn_is_valid_transition(tconn, mask, val, flags);
1772         if (rv < SS_SUCCESS)
1773                 goto abort;
1774
1775         if (oc == C_WF_REPORT_PARAMS && val.conn == C_DISCONNECTING &&
1776             !(flags & (CS_LOCAL_ONLY | CS_HARD))) {
1777
1778                 /* This will be a cluster-wide state change.
1779                  * Need to give up the spinlock, grab the mutex,
1780                  * then send the state change request, ... */
1781                 spin_unlock_irq(&tconn->req_lock);
1782                 mutex_lock(&tconn->cstate_mutex);
1783                 have_mutex = true;
1784
1785                 set_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);
1786                 if (conn_send_state_req(tconn, mask, val)) {
1787                         /* sending failed. */
1788                         clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);
1789                         rv = SS_CW_FAILED_BY_PEER;
1790                         /* need to re-aquire the spin lock, though */
1791                         goto abort_unlocked;
1792                 }
1793
1794                 if (val.conn == C_DISCONNECTING)
1795                         set_bit(DISCONNECT_SENT, &tconn->flags);
1796
1797                 /* ... and re-aquire the spinlock.
1798                  * If _conn_rq_cond() returned >= SS_SUCCESS, we must call
1799                  * conn_set_state() within the same spinlock. */
1800                 spin_lock_irq(&tconn->req_lock);
1801                 wait_event_lock_irq(tconn->ping_wait,
1802                                 (rv = _conn_rq_cond(tconn, mask, val)),
1803                                 tconn->req_lock);
1804                 clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);
1805                 if (rv < SS_SUCCESS)
1806                         goto abort;
1807         }
1808
1809         conn_old_common_state(tconn, &os, &flags);
1810         flags |= CS_DC_SUSP;
1811         conn_set_state(tconn, mask, val, &ns_min, &ns_max, flags);
1812         conn_pr_state_change(tconn, os, ns_max, flags);
1813
1814         acscw = kmalloc(sizeof(*acscw), GFP_ATOMIC);
1815         if (acscw) {
1816                 acscw->oc = os.conn;
1817                 acscw->ns_min = ns_min;
1818                 acscw->ns_max = ns_max;
1819                 acscw->flags = flags;
1820                 acscw->w.cb = w_after_conn_state_ch;
1821                 kref_get(&tconn->kref);
1822                 acscw->w.tconn = tconn;
1823                 drbd_queue_work(&tconn->sender_work, &acscw->w);
1824         } else {
1825                 conn_err(tconn, "Could not kmalloc an acscw\n");
1826         }
1827
1828  abort:
1829         if (have_mutex) {
1830                 /* mutex_unlock() "... must not be used in interrupt context.",
1831                  * so give up the spinlock, then re-aquire it */
1832                 spin_unlock_irq(&tconn->req_lock);
1833  abort_unlocked:
1834                 mutex_unlock(&tconn->cstate_mutex);
1835                 spin_lock_irq(&tconn->req_lock);
1836         }
1837         if (rv < SS_SUCCESS && flags & CS_VERBOSE) {
1838                 conn_err(tconn, "State change failed: %s\n", drbd_set_st_err_str(rv));
1839                 conn_err(tconn, " mask = 0x%x val = 0x%x\n", mask.i, val.i);
1840                 conn_err(tconn, " old_conn:%s wanted_conn:%s\n", drbd_conn_str(oc), drbd_conn_str(val.conn));
1841         }
1842         return rv;
1843 }
1844
1845 enum drbd_state_rv
1846 conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val,
1847                    enum chg_state_flags flags)
1848 {
1849         enum drbd_state_rv rv;
1850
1851         spin_lock_irq(&tconn->req_lock);
1852         rv = _conn_request_state(tconn, mask, val, flags);
1853         spin_unlock_irq(&tconn->req_lock);
1854
1855         return rv;
1856 }