fs/dlm/recoverd.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /******************************************************************************
   3 *******************************************************************************
   4 **
   5 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   6 **  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
   7 **
   8 **
   9 *******************************************************************************
  10 ******************************************************************************/
  11
  12 #include "dlm_internal.h"
  13 #include "lockspace.h"
  14 #include "member.h"
  15 #include "dir.h"
  16 #include "ast.h"
  17 #include "recover.h"
  18 #include "lowcomms.h"
  19 #include "lock.h"
  20 #include "requestqueue.h"
  21 #include "recoverd.h"
  22
  23
  24 /* If the start for which we're re-enabling locking (seq) has been superseded
  25    by a newer stop (ls_recover_seq), we need to leave locking disabled.
  26
  27    We suspend dlm_recv threads here to avoid the race where dlm_recv a) sees
  28    locking stopped and b) adds a message to the requestqueue, but dlm_recoverd
  29    enables locking and clears the requestqueue between a and b. */
  30
  31 static int enable_locking(struct dlm_ls *ls, uint64_t seq)
  32 {
  33         int error = -EINTR;
  34
  35         down_write(&ls->ls_recv_active);
  36
  37         spin_lock(&ls->ls_recover_lock);
  38         if (ls->ls_recover_seq == seq) {
  39                 set_bit(LSFL_RUNNING, &ls->ls_flags);
  40                 /* unblocks processes waiting to enter the dlm */
  41                 up_write(&ls->ls_in_recovery);
  42                 clear_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
  43                 error = 0;
  44         }
  45         spin_unlock(&ls->ls_recover_lock);
  46
  47         up_write(&ls->ls_recv_active);
  48         return error;
  49 }
  50
  51 static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
  52 {
  53         unsigned long start;
  54         int error, neg = 0;
  55
  56         log_rinfo(ls, "dlm_recover %llu", (unsigned long long)rv->seq);
  57
  58         mutex_lock(&ls->ls_recoverd_active);
  59
  60         dlm_callback_suspend(ls);
  61
  62         dlm_clear_toss(ls);
  63
  64         /*
  65          * This list of root rsb's will be the basis of most of the recovery
  66          * routines.
  67          */
  68
  69         dlm_create_root_list(ls);
  70
  71         /*
  72          * Add or remove nodes from the lockspace's ls_nodes list.
  73          *
  74          * Due to the fact that we must report all membership changes to lsops
  75          * or midcomms layer, it is not permitted to abort ls_recover() until
  76          * this is done.
  77          */
  78
  79         error = dlm_recover_members(ls, rv, &neg);
  80         if (error) {
  81                 log_rinfo(ls, "dlm_recover_members error %d", error);
  82                 goto fail;
  83         }
  84
  85         dlm_recover_dir_nodeid(ls);
  86
  87         ls->ls_recover_dir_sent_res = 0;
  88         ls->ls_recover_dir_sent_msg = 0;
  89         ls->ls_recover_locks_in = 0;
  90
  91         dlm_set_recover_status(ls, DLM_RS_NODES);
  92
  93         error = dlm_recover_members_wait(ls);
  94         if (error) {
  95                 log_rinfo(ls, "dlm_recover_members_wait error %d", error);
  96                 goto fail;
  97         }
  98
  99         start = jiffies;
 100
 101         /*
 102          * Rebuild our own share of the directory by collecting from all other
 103          * nodes their master rsb names that hash to us.
 104          */
 105
 106         error = dlm_recover_directory(ls);
 107         if (error) {
 108                 log_rinfo(ls, "dlm_recover_directory error %d", error);
 109                 goto fail;
 110         }
 111
 112         dlm_set_recover_status(ls, DLM_RS_DIR);
 113
 114         error = dlm_recover_directory_wait(ls);
 115         if (error) {
 116                 log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
 117                 goto fail;
 118         }
 119
 120         log_rinfo(ls, "dlm_recover_directory %u out %u messages",
 121                   ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);
 122
 123         /*
 124          * We may have outstanding operations that are waiting for a reply from
 125          * a failed node.  Mark these to be resent after recovery.  Unlock and
 126          * cancel ops can just be completed.
 127          */
 128
 129         dlm_recover_waiters_pre(ls);
 130
 131         if (dlm_recovery_stopped(ls)) {
 132                 error = -EINTR;
 133                 goto fail;
 134         }
 135
 136         if (neg || dlm_no_directory(ls)) {
 137                 /*
 138                  * Clear lkb's for departed nodes.
 139                  */
 140
 141                 dlm_recover_purge(ls);
 142
 143                 /*
 144                  * Get new master nodeid's for rsb's that were mastered on
 145                  * departed nodes.
 146                  */
 147
 148                 error = dlm_recover_masters(ls);
 149                 if (error) {
 150                         log_rinfo(ls, "dlm_recover_masters error %d", error);
 151                         goto fail;
 152                 }
 153
 154                 /*
 155                  * Send our locks on remastered rsb's to the new masters.
 156                  */
 157
 158                 error = dlm_recover_locks(ls);
 159                 if (error) {
 160                         log_rinfo(ls, "dlm_recover_locks error %d", error);
 161                         goto fail;
 162                 }
 163
 164                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
 165
 166                 error = dlm_recover_locks_wait(ls);
 167                 if (error) {
 168                         log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
 169                         goto fail;
 170                 }
 171
 172                 log_rinfo(ls, "dlm_recover_locks %u in",
 173                           ls->ls_recover_locks_in);
 174
 175                 /*
 176                  * Finalize state in master rsb's now that all locks can be
 177                  * checked.  This includes conversion resolution and lvb
 178                  * settings.
 179                  */
 180
 181                 dlm_recover_rsbs(ls);
 182         } else {
 183                 /*
 184                  * Other lockspace members may be going through the "neg" steps
 185                  * while also adding us to the lockspace, in which case they'll
 186                  * be doing the recover_locks (RS_LOCKS) barrier.
 187                  */
 188                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
 189
 190                 error = dlm_recover_locks_wait(ls);
 191                 if (error) {
 192                         log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
 193                         goto fail;
 194                 }
 195         }
 196
 197         dlm_release_root_list(ls);
 198
 199         /*
 200          * Purge directory-related requests that are saved in requestqueue.
 201          * All dir requests from before recovery are invalid now due to the dir
 202          * rebuild and will be resent by the requesting nodes.
 203          */
 204
 205         dlm_purge_requestqueue(ls);
 206
 207         dlm_set_recover_status(ls, DLM_RS_DONE);
 208
 209         error = dlm_recover_done_wait(ls);
 210         if (error) {
 211                 log_rinfo(ls, "dlm_recover_done_wait error %d", error);
 212                 goto fail;
 213         }
 214
 215         dlm_clear_members_gone(ls);
 216
 217         dlm_callback_resume(ls);
 218
 219         error = enable_locking(ls, rv->seq);
 220         if (error) {
 221                 log_rinfo(ls, "enable_locking error %d", error);
 222                 goto fail;
 223         }
 224
 225         error = dlm_process_requestqueue(ls);
 226         if (error) {
 227                 log_rinfo(ls, "dlm_process_requestqueue error %d", error);
 228                 goto fail;
 229         }
 230
 231         error = dlm_recover_waiters_post(ls);
 232         if (error) {
 233                 log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
 234                 goto fail;
 235         }
 236
 237         dlm_recover_grant(ls);
 238
 239         log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
 240                   (unsigned long long)rv->seq, ls->ls_generation,
 241                   jiffies_to_msecs(jiffies - start));
 242         mutex_unlock(&ls->ls_recoverd_active);
 243
 244         return 0;
 245
 246  fail:
 247         dlm_release_root_list(ls);
 248         mutex_unlock(&ls->ls_recoverd_active);
 249
 250         return error;
 251 }
 252
 253 /* The dlm_ls_start() that created the rv we take here may already have been
 254    stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
 255    flag set. */
 256
 257 static void do_ls_recovery(struct dlm_ls *ls)
 258 {
 259         struct dlm_recover *rv = NULL;
 260         int error;
 261
 262         spin_lock(&ls->ls_recover_lock);
 263         rv = ls->ls_recover_args;
 264         ls->ls_recover_args = NULL;
 265         if (rv && ls->ls_recover_seq == rv->seq)
 266                 clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
 267         spin_unlock(&ls->ls_recover_lock);
 268
 269         if (rv) {
 270                 error = ls_recover(ls, rv);
 271                 switch (error) {
 272                 case 0:
 273                         ls->ls_recovery_result = 0;
 274                         complete(&ls->ls_recovery_done);
 275
 276                         dlm_lsop_recover_done(ls);
 277                         break;
 278                 case -EINTR:
 279                         /* if recovery was interrupted -EINTR we wait for the next
 280                          * ls_recover() iteration until it hopefully succeeds.
 281                          */
 282                         log_rinfo(ls, "%s %llu interrupted and should be queued to run again",
 283                                   __func__, (unsigned long long)rv->seq);
 284                         break;
 285                 default:
 286                         log_rinfo(ls, "%s %llu error %d", __func__,
 287                                   (unsigned long long)rv->seq, error);
 288
 289                         /* let new_lockspace() get aware of critical error */
 290                         ls->ls_recovery_result = error;
 291                         complete(&ls->ls_recovery_done);
 292                         break;
 293                 }
 294
 295                 kfree(rv->nodes);
 296                 kfree(rv);
 297         }
 298 }
 299
 300 static int dlm_recoverd(void *arg)
 301 {
 302         struct dlm_ls *ls;
 303
 304         ls = dlm_find_lockspace_local(arg);
 305         if (!ls) {
 306                 log_print("dlm_recoverd: no lockspace %p", arg);
 307                 return -1;
 308         }
 309
 310         down_write(&ls->ls_in_recovery);
 311         set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
 312         wake_up(&ls->ls_recover_lock_wait);
 313
 314         while (1) {
 315                 /*
 316                  * We call kthread_should_stop() after set_current_state().
 317                  * This is because it works correctly if kthread_stop() is
 318                  * called just before set_current_state().
 319                  */
 320                 set_current_state(TASK_INTERRUPTIBLE);
 321                 if (kthread_should_stop()) {
 322                         set_current_state(TASK_RUNNING);
 323                         break;
 324                 }
 325                 if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
 326                     !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
 327                         if (kthread_should_stop())
 328                                 break;
 329                         schedule();
 330                 }
 331                 set_current_state(TASK_RUNNING);
 332
 333                 if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
 334                         down_write(&ls->ls_in_recovery);
 335                         set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
 336                         wake_up(&ls->ls_recover_lock_wait);
 337                 }
 338
 339                 if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
 340                         do_ls_recovery(ls);
 341         }
 342
 343         if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
 344                 up_write(&ls->ls_in_recovery);
 345
 346         dlm_put_lockspace(ls);
 347         return 0;
 348 }
 349
 350 int dlm_recoverd_start(struct dlm_ls *ls)
 351 {
 352         struct task_struct *p;
 353         int error = 0;
 354
 355         p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
 356         if (IS_ERR(p))
 357                 error = PTR_ERR(p);
 358         else
 359                 ls->ls_recoverd_task = p;
 360         return error;
 361 }
 362
 363 void dlm_recoverd_stop(struct dlm_ls *ls)
 364 {
 365         kthread_stop(ls->ls_recoverd_task);
 366 }
 367
 368 void dlm_recoverd_suspend(struct dlm_ls *ls)
 369 {
 370         wake_up(&ls->ls_wait_general);
 371         mutex_lock(&ls->ls_recoverd_active);
 372 }
 373
 374 void dlm_recoverd_resume(struct dlm_ls *ls)
 375 {
 376         mutex_unlock(&ls->ls_recoverd_active);
 377 }
 378