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  24 /* If the start for which we're re-enabling locking (seq) has been superseded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
  75         error = dlm_recover_members(ls, rv, &neg);
  76         if (error) {
  77                 log_rinfo(ls, "dlm_recover_members error %d", error);
  78                 goto fail;
  79         }
  80
  81         dlm_recover_dir_nodeid(ls);
  82
  83         ls->ls_recover_dir_sent_res = 0;
  84         ls->ls_recover_dir_sent_msg = 0;
  85         ls->ls_recover_locks_in = 0;
  86
  87         dlm_set_recover_status(ls, DLM_RS_NODES);
  88
  89         error = dlm_recover_members_wait(ls);
  90         if (error) {
  91                 log_rinfo(ls, "dlm_recover_members_wait error %d", error);
  92                 goto fail;
  93         }
  94
  95         start = jiffies;
  96
  97         /*
  98          * Rebuild our own share of the directory by collecting from all other
  99          * nodes their master rsb names that hash to us.
 100          */
 101
 102         error = dlm_recover_directory(ls);
 103         if (error) {
 104                 log_rinfo(ls, "dlm_recover_directory error %d", error);
 105                 goto fail;
 106         }
 107
 108         dlm_set_recover_status(ls, DLM_RS_DIR);
 109
 110         error = dlm_recover_directory_wait(ls);
 111         if (error) {
 112                 log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
 113                 goto fail;
 114         }
 115
 116         log_rinfo(ls, "dlm_recover_directory %u out %u messages",
 117                   ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);
 118
 119         /*
 120          * We may have outstanding operations that are waiting for a reply from
 121          * a failed node.  Mark these to be resent after recovery.  Unlock and
 122          * cancel ops can just be completed.
 123          */
 124
 125         dlm_recover_waiters_pre(ls);
 126
 127         if (dlm_recovery_stopped(ls)) {
 128                 error = -EINTR;
 129                 goto fail;
 130         }
 131
 132         if (neg || dlm_no_directory(ls)) {
 133                 /*
 134                  * Clear lkb's for departed nodes.
 135                  */
 136
 137                 dlm_recover_purge(ls);
 138
 139                 /*
 140                  * Get new master nodeid's for rsb's that were mastered on
 141                  * departed nodes.
 142                  */
 143
 144                 error = dlm_recover_masters(ls);
 145                 if (error) {
 146                         log_rinfo(ls, "dlm_recover_masters error %d", error);
 147                         goto fail;
 148                 }
 149
 150                 /*
 151                  * Send our locks on remastered rsb's to the new masters.
 152                  */
 153
 154                 error = dlm_recover_locks(ls);
 155                 if (error) {
 156                         log_rinfo(ls, "dlm_recover_locks error %d", error);
 157                         goto fail;
 158                 }
 159
 160                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
 161
 162                 error = dlm_recover_locks_wait(ls);
 163                 if (error) {
 164                         log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
 165                         goto fail;
 166                 }
 167
 168                 log_rinfo(ls, "dlm_recover_locks %u in",
 169                           ls->ls_recover_locks_in);
 170
 171                 /*
 172                  * Finalize state in master rsb's now that all locks can be
 173                  * checked.  This includes conversion resolution and lvb
 174                  * settings.
 175                  */
 176
 177                 dlm_recover_rsbs(ls);
 178         } else {
 179                 /*
 180                  * Other lockspace members may be going through the "neg" steps
 181                  * while also adding us to the lockspace, in which case they'll
 182                  * be doing the recover_locks (RS_LOCKS) barrier.
 183                  */
 184                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
 185
 186                 error = dlm_recover_locks_wait(ls);
 187                 if (error) {
 188                         log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
 189                         goto fail;
 190                 }
 191         }
 192
 193         dlm_release_root_list(ls);
 194
 195         /*
 196          * Purge directory-related requests that are saved in requestqueue.
 197          * All dir requests from before recovery are invalid now due to the dir
 198          * rebuild and will be resent by the requesting nodes.
 199          */
 200
 201         dlm_purge_requestqueue(ls);
 202
 203         dlm_set_recover_status(ls, DLM_RS_DONE);
 204
 205         error = dlm_recover_done_wait(ls);
 206         if (error) {
 207                 log_rinfo(ls, "dlm_recover_done_wait error %d", error);
 208                 goto fail;
 209         }
 210
 211         dlm_clear_members_gone(ls);
 212
 213         dlm_adjust_timeouts(ls);
 214
 215         dlm_callback_resume(ls);
 216
 217         error = enable_locking(ls, rv->seq);
 218         if (error) {
 219                 log_rinfo(ls, "enable_locking error %d", error);
 220                 goto fail;
 221         }
 222
 223         error = dlm_process_requestqueue(ls);
 224         if (error) {
 225                 log_rinfo(ls, "dlm_process_requestqueue error %d", error);
 226                 goto fail;
 227         }
 228
 229         error = dlm_recover_waiters_post(ls);
 230         if (error) {
 231                 log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
 232                 goto fail;
 233         }
 234
 235         dlm_recover_grant(ls);
 236
 237         log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
 238                   (unsigned long long)rv->seq, ls->ls_generation,
 239                   jiffies_to_msecs(jiffies - start));
 240         mutex_unlock(&ls->ls_recoverd_active);
 241
 242         dlm_lsop_recover_done(ls);
 243         return 0;
 244
 245  fail:
 246         dlm_release_root_list(ls);
 247         log_rinfo(ls, "dlm_recover %llu error %d",
 248                   (unsigned long long)rv->seq, error);
 249         mutex_unlock(&ls->ls_recoverd_active);
 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
 261         spin_lock(&ls->ls_recover_lock);
 262         rv = ls->ls_recover_args;
 263         ls->ls_recover_args = NULL;
 264         if (rv && ls->ls_recover_seq == rv->seq)
 265                 clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
 266         spin_unlock(&ls->ls_recover_lock);
 267
 268         if (rv) {
 269                 ls_recover(ls, rv);
 270                 kfree(rv->nodes);
 271                 kfree(rv);
 272         }
 273 }
 274
 275 static int dlm_recoverd(void *arg)
 276 {
 277         struct dlm_ls *ls;
 278
 279         ls = dlm_find_lockspace_local(arg);
 280         if (!ls) {
 281                 log_print("dlm_recoverd: no lockspace %p", arg);
 282                 return -1;
 283         }
 284
 285         down_write(&ls->ls_in_recovery);
 286         set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
 287         wake_up(&ls->ls_recover_lock_wait);
 288
 289         while (1) {
 290                 /*
 291                  * We call kthread_should_stop() after set_current_state().
 292                  * This is because it works correctly if kthread_stop() is
 293                  * called just before set_current_state().
 294                  */
 295                 set_current_state(TASK_INTERRUPTIBLE);
 296                 if (kthread_should_stop()) {
 297                         set_current_state(TASK_RUNNING);
 298                         break;
 299                 }
 300                 if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
 301                     !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
 302                         if (kthread_should_stop())
 303                                 break;
 304                         schedule();
 305                 }
 306                 set_current_state(TASK_RUNNING);
 307
 308                 if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
 309                         down_write(&ls->ls_in_recovery);
 310                         set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
 311                         wake_up(&ls->ls_recover_lock_wait);
 312                 }
 313
 314                 if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
 315                         do_ls_recovery(ls);
 316         }
 317
 318         if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
 319                 up_write(&ls->ls_in_recovery);
 320
 321         dlm_put_lockspace(ls);
 322         return 0;
 323 }
 324
 325 int dlm_recoverd_start(struct dlm_ls *ls)
 326 {
 327         struct task_struct *p;
 328         int error = 0;
 329
 330         p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
 331         if (IS_ERR(p))
 332                 error = PTR_ERR(p);
 333         else
 334                 ls->ls_recoverd_task = p;
 335         return error;
 336 }
 337
 338 void dlm_recoverd_stop(struct dlm_ls *ls)
 339 {
 340         kthread_stop(ls->ls_recoverd_task);
 341 }
 342
 343 void dlm_recoverd_suspend(struct dlm_ls *ls)
 344 {
 345         wake_up(&ls->ls_wait_general);
 346         mutex_lock(&ls->ls_recoverd_active);
 347 }
 348
 349 void dlm_recoverd_resume(struct dlm_ls *ls)
 350 {
 351         mutex_unlock(&ls->ls_recoverd_active);
 352 }
 353