git.oblomov.eu Git - linux-2.6/blob - fs/dlm/recoverd.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5 **  Copyright (C) 2004-2007 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  26 /* If the start for which we're re-enabling locking (seq) has been superseded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, "recover %llx", (unsigned long long)rv->seq);
  58
  59         mutex_lock(&ls->ls_recoverd_active);
  60
  61         /*
  62          * Suspending and resuming dlm_astd ensures that no lkb's from this ls
  63          * will be processed by dlm_astd during recovery.
  64          */
  65
  66         dlm_astd_suspend();
  67         dlm_astd_resume();
  68
  69         /*
  70          * Free non-master tossed rsb's.  Master rsb's are kept on toss
  71          * list and put on root list to be included in resdir recovery.
  72          */
  73
  74         dlm_clear_toss_list(ls);
  75
  76         /*
  77          * This list of root rsb's will be the basis of most of the recovery
  78          * routines.
  79          */
  80
  81         dlm_create_root_list(ls);
  82
  83         /*
  84          * Add or remove nodes from the lockspace's ls_nodes list.
  85          * Also waits for all nodes to complete dlm_recover_members.
  86          */
  87
  88         error = dlm_recover_members(ls, rv, &neg);
  89         if (error) {
  90                 log_debug(ls, "recover_members failed %d", error);
  91                 goto fail;
  92         }
  93         start = jiffies;
  94
  95         /*
  96          * Rebuild our own share of the directory by collecting from all other
  97          * nodes their master rsb names that hash to us.
  98          */
  99
 100         error = dlm_recover_directory(ls);
 101         if (error) {
 102                 log_debug(ls, "recover_directory failed %d", error);
 103                 goto fail;
 104         }
 105
 106         /*
 107          * Wait for all nodes to complete directory rebuild.
 108          */
 109
 110         error = dlm_recover_directory_wait(ls);
 111         if (error) {
 112                 log_debug(ls, "recover_directory_wait failed %d", error);
 113                 goto fail;
 114         }
 115
 116         /*
 117          * We may have outstanding operations that are waiting for a reply from
 118          * a failed node.  Mark these to be resent after recovery.  Unlock and
 119          * cancel ops can just be completed.
 120          */
 121
 122         dlm_recover_waiters_pre(ls);
 123
 124         error = dlm_recovery_stopped(ls);
 125         if (error)
 126                 goto fail;
 127
 128         if (neg || dlm_no_directory(ls)) {
 129                 /*
 130                  * Clear lkb's for departed nodes.
 131                  */
 132
 133                 dlm_purge_locks(ls);
 134
 135                 /*
 136                  * Get new master nodeid's for rsb's that were mastered on
 137                  * departed nodes.
 138                  */
 139
 140                 error = dlm_recover_masters(ls);
 141                 if (error) {
 142                         log_debug(ls, "recover_masters failed %d", error);
 143                         goto fail;
 144                 }
 145
 146                 /*
 147                  * Send our locks on remastered rsb's to the new masters.
 148                  */
 149
 150                 error = dlm_recover_locks(ls);
 151                 if (error) {
 152                         log_debug(ls, "recover_locks failed %d", error);
 153                         goto fail;
 154                 }
 155
 156                 error = dlm_recover_locks_wait(ls);
 157                 if (error) {
 158                         log_debug(ls, "recover_locks_wait failed %d", error);
 159                         goto fail;
 160                 }
 161
 162                 /*
 163                  * Finalize state in master rsb's now that all locks can be
 164                  * checked.  This includes conversion resolution and lvb
 165                  * settings.
 166                  */
 167
 168                 dlm_recover_rsbs(ls);
 169         } else {
 170                 /*
 171                  * Other lockspace members may be going through the "neg" steps
 172                  * while also adding us to the lockspace, in which case they'll
 173                  * be doing the recover_locks (RS_LOCKS) barrier.
 174                  */
 175                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
 176
 177                 error = dlm_recover_locks_wait(ls);
 178                 if (error) {
 179                         log_debug(ls, "recover_locks_wait failed %d", error);
 180                         goto fail;
 181                 }
 182         }
 183
 184         dlm_release_root_list(ls);
 185
 186         /*
 187          * Purge directory-related requests that are saved in requestqueue.
 188          * All dir requests from before recovery are invalid now due to the dir
 189          * rebuild and will be resent by the requesting nodes.
 190          */
 191
 192         dlm_purge_requestqueue(ls);
 193
 194         dlm_set_recover_status(ls, DLM_RS_DONE);
 195         error = dlm_recover_done_wait(ls);
 196         if (error) {
 197                 log_debug(ls, "recover_done_wait failed %d", error);
 198                 goto fail;
 199         }
 200
 201         dlm_clear_members_gone(ls);
 202
 203         dlm_adjust_timeouts(ls);
 204
 205         error = enable_locking(ls, rv->seq);
 206         if (error) {
 207                 log_debug(ls, "enable_locking failed %d", error);
 208                 goto fail;
 209         }
 210
 211         error = dlm_process_requestqueue(ls);
 212         if (error) {
 213                 log_debug(ls, "process_requestqueue failed %d", error);
 214                 goto fail;
 215         }
 216
 217         error = dlm_recover_waiters_post(ls);
 218         if (error) {
 219                 log_debug(ls, "recover_waiters_post failed %d", error);
 220                 goto fail;
 221         }
 222
 223         dlm_grant_after_purge(ls);
 224
 225         dlm_astd_wake();
 226
 227         log_debug(ls, "recover %llx done: %u ms",
 228                   (unsigned long long)rv->seq,
 229                   jiffies_to_msecs(jiffies - start));
 230         mutex_unlock(&ls->ls_recoverd_active);
 231
 232         return 0;
 233
 234  fail:
 235         dlm_release_root_list(ls);
 236         log_debug(ls, "recover %llx error %d",
 237                   (unsigned long long)rv->seq, error);
 238         mutex_unlock(&ls->ls_recoverd_active);
 239         return error;
 240 }
 241
 242 /* The dlm_ls_start() that created the rv we take here may already have been
 243    stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
 244    flag set. */
 245
 246 static void do_ls_recovery(struct dlm_ls *ls)
 247 {
 248         struct dlm_recover *rv = NULL;
 249
 250         spin_lock(&ls->ls_recover_lock);
 251         rv = ls->ls_recover_args;
 252         ls->ls_recover_args = NULL;
 253         if (rv && ls->ls_recover_seq == rv->seq)
 254                 clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
 255         spin_unlock(&ls->ls_recover_lock);
 256
 257         if (rv) {
 258                 ls_recover(ls, rv);
 259                 kfree(rv->nodeids);
 260                 kfree(rv);
 261         }
 262 }
 263
 264 static int dlm_recoverd(void *arg)
 265 {
 266         struct dlm_ls *ls;
 267
 268         ls = dlm_find_lockspace_local(arg);
 269         if (!ls) {
 270                 log_print("dlm_recoverd: no lockspace %p", arg);
 271                 return -1;
 272         }
 273
 274         while (!kthread_should_stop()) {
 275                 set_current_state(TASK_INTERRUPTIBLE);
 276                 if (!test_bit(LSFL_WORK, &ls->ls_flags))
 277                         schedule();
 278                 set_current_state(TASK_RUNNING);
 279
 280                 if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags))
 281                         do_ls_recovery(ls);
 282         }
 283
 284         dlm_put_lockspace(ls);
 285         return 0;
 286 }
 287
 288 void dlm_recoverd_kick(struct dlm_ls *ls)
 289 {
 290         set_bit(LSFL_WORK, &ls->ls_flags);
 291         wake_up_process(ls->ls_recoverd_task);
 292 }
 293
 294 int dlm_recoverd_start(struct dlm_ls *ls)
 295 {
 296         struct task_struct *p;
 297         int error = 0;
 298
 299         p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
 300         if (IS_ERR(p))
 301                 error = PTR_ERR(p);
 302         else
 303                 ls->ls_recoverd_task = p;
 304         return error;
 305 }
 306
 307 void dlm_recoverd_stop(struct dlm_ls *ls)
 308 {
 309         kthread_stop(ls->ls_recoverd_task);
 310 }
 311
 312 void dlm_recoverd_suspend(struct dlm_ls *ls)
 313 {
 314         wake_up(&ls->ls_wait_general);
 315         mutex_lock(&ls->ls_recoverd_active);
 316 }
 317
 318 void dlm_recoverd_resume(struct dlm_ls *ls)
 319 {
 320         mutex_unlock(&ls->ls_recoverd_active);
 321 }
 322