fs/dlm/recoverd.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5 **  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
   6 **
   7 **  This copyrighted material is made available to anyone wishing to use,
   8 **  modify, copy, or redistribute it subject to the terms and conditions
   9 **  of the GNU General Public License v.2.
  10 **
  11 *******************************************************************************
  12 ******************************************************************************/
  13
  14 #include "dlm_internal.h"
  15 #include "lockspace.h"
  16 #include "member.h"
  17 #include "dir.h"
  18 #include "ast.h"
  19 #include "recover.h"
  20 #include "lowcomms.h"
  21 #include "lock.h"
  22 #include "requestqueue.h"
  23 #include "recoverd.h"
  24
  25
  26 /* If the start for which we're re-enabling locking (seq) has been superseded
  27    by a newer stop (ls_recover_seq), we need to leave locking disabled.
  28
  29    We suspend dlm_recv threads here to avoid the race where dlm_recv a) sees
  30    locking stopped and b) adds a message to the requestqueue, but dlm_recoverd
  31    enables locking and clears the requestqueue between a and b. */
  32
  33 static int enable_locking(struct dlm_ls *ls, uint64_t seq)
  34 {
  35         int error = -EINTR;
  36
  37         down_write(&ls->ls_recv_active);
  38
  39         spin_lock(&ls->ls_recover_lock);
  40         if (ls->ls_recover_seq == seq) {
  41                 set_bit(LSFL_RUNNING, &ls->ls_flags);
  42                 /* unblocks processes waiting to enter the dlm */
  43                 up_write(&ls->ls_in_recovery);
  44                 error = 0;
  45         }
  46         spin_unlock(&ls->ls_recover_lock);
  47
  48         up_write(&ls->ls_recv_active);
  49         return error;
  50 }
  51
  52 static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
  53 {
  54         unsigned long start;
  55         int error, neg = 0;
  56
  57         log_debug(ls, "dlm_recover %llu", (unsigned long long)rv->seq);
  58
  59         mutex_lock(&ls->ls_recoverd_active);
  60
  61         dlm_callback_suspend(ls);
  62
  63         dlm_clear_toss(ls);
  64
  65         /*
  66          * This list of root rsb's will be the basis of most of the recovery
  67          * routines.
  68          */
  69
  70         dlm_create_root_list(ls);
  71
  72         /*
  73          * Add or remove nodes from the lockspace's ls_nodes list.
  74          */
  75
  76         error = dlm_recover_members(ls, rv, &neg);
  77         if (error) {
  78                 log_debug(ls, "dlm_recover_members error %d", error);
  79                 goto fail;
  80         }
  81
  82         dlm_recover_dir_nodeid(ls);
  83
  84         ls->ls_recover_dir_sent_res = 0;
  85         ls->ls_recover_dir_sent_msg = 0;
  86         ls->ls_recover_locks_in = 0;
  87
  88         dlm_set_recover_status(ls, DLM_RS_NODES);
  89
  90         error = dlm_recover_members_wait(ls);
  91         if (error) {
  92                 log_debug(ls, "dlm_recover_members_wait error %d", error);
  93                 goto fail;
  94         }
  95
  96         start = jiffies;
  97
  98         /*
  99          * Rebuild our own share of the directory by collecting from all other
 100          * nodes their master rsb names that hash to us.
 101          */
 102
 103         error = dlm_recover_directory(ls);
 104         if (error) {
 105                 log_debug(ls, "dlm_recover_directory error %d", error);
 106                 goto fail;
 107         }
 108
 109         dlm_set_recover_status(ls, DLM_RS_DIR);
 110
 111         error = dlm_recover_directory_wait(ls);
 112         if (error) {
 113                 log_debug(ls, "dlm_recover_directory_wait error %d", error);
 114                 goto fail;
 115         }
 116
 117         log_debug(ls, "dlm_recover_directory %u out %u messages",
 118                   ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);
 119
 120         /*
 121          * We may have outstanding operations that are waiting for a reply from
 122          * a failed node.  Mark these to be resent after recovery.  Unlock and
 123          * cancel ops can just be completed.
 124          */
 125
 126         dlm_recover_waiters_pre(ls);
 127
 128         error = dlm_recovery_stopped(ls);
 129         if (error)
 130                 goto fail;
 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_debug(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_debug(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_debug(ls, "dlm_recover_locks_wait error %d", error);
 165                         goto fail;
 166                 }
 167
 168                 log_debug(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_debug(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_debug(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_debug(ls, "enable_locking error %d", error);
 220                 goto fail;
 221         }
 222
 223         error = dlm_process_requestqueue(ls);
 224         if (error) {
 225                 log_debug(ls, "dlm_process_requestqueue error %d", error);
 226                 goto fail;
 227         }
 228
 229         error = dlm_recover_waiters_post(ls);
 230         if (error) {
 231                 log_debug(ls, "dlm_recover_waiters_post error %d", error);
 232                 goto fail;
 233         }
 234
 235         dlm_recover_grant(ls);
 236
 237         log_debug(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_debug(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_RECOVERY_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         while (!kthread_should_stop()) {
 286                 set_current_state(TASK_INTERRUPTIBLE);
 287                 if (!test_bit(LSFL_WORK, &ls->ls_flags))
 288                         schedule();
 289                 set_current_state(TASK_RUNNING);
 290
 291                 if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags))
 292                         do_ls_recovery(ls);
 293         }
 294
 295         dlm_put_lockspace(ls);
 296         return 0;
 297 }
 298
 299 void dlm_recoverd_kick(struct dlm_ls *ls)
 300 {
 301         set_bit(LSFL_WORK, &ls->ls_flags);
 302         wake_up_process(ls->ls_recoverd_task);
 303 }
 304
 305 int dlm_recoverd_start(struct dlm_ls *ls)
 306 {
 307         struct task_struct *p;
 308         int error = 0;
 309
 310         p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
 311         if (IS_ERR(p))
 312                 error = PTR_ERR(p);
 313         else
 314                 ls->ls_recoverd_task = p;
 315         return error;
 316 }
 317
 318 void dlm_recoverd_stop(struct dlm_ls *ls)
 319 {
 320         kthread_stop(ls->ls_recoverd_task);
 321 }
 322
 323 void dlm_recoverd_suspend(struct dlm_ls *ls)
 324 {
 325         wake_up(&ls->ls_wait_general);
 326         mutex_lock(&ls->ls_recoverd_active);
 327 }
 328
 329 void dlm_recoverd_resume(struct dlm_ls *ls)
 330 {
 331         mutex_unlock(&ls->ls_recoverd_active);
 332 }
 333