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  26 /* If the start for which we're re-enabling locking (seq) has been superseded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