fs/dlm/member.c

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) 2005 Red Hat, Inc.  All rights reserved.
   5 **
   6 **  This copyrighted material is made available to anyone wishing to use,
   7 **  modify, copy, or redistribute it subject to the terms and conditions
   8 **  of the GNU General Public License v.2.
   9 **
  10 *******************************************************************************
  11 ******************************************************************************/
  12
  13 #include "dlm_internal.h"
  14 #include "lockspace.h"
  15 #include "member.h"
  16 #include "recoverd.h"
  17 #include "recover.h"
  18 #include "lowcomms.h"
  19 #include "rcom.h"
  20 #include "config.h"
  21
  22 /*
  23  * Following called by dlm_recoverd thread
  24  */
  25
  26 static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
  27 {
  28         struct dlm_member *memb = NULL;
  29         struct list_head *tmp;
  30         struct list_head *newlist = &new->list;
  31         struct list_head *head = &ls->ls_nodes;
  32
  33         list_for_each(tmp, head) {
  34                 memb = list_entry(tmp, struct dlm_member, list);
  35                 if (new->nodeid < memb->nodeid)
  36                         break;
  37         }
  38
  39         if (!memb)
  40                 list_add_tail(newlist, head);
  41         else {
  42                 /* FIXME: can use list macro here */
  43                 newlist->prev = tmp->prev;
  44                 newlist->next = tmp;
  45                 tmp->prev->next = newlist;
  46                 tmp->prev = newlist;
  47         }
  48 }
  49
  50 static int dlm_add_member(struct dlm_ls *ls, int nodeid)
  51 {
  52         struct dlm_member *memb;
  53         int w;
  54
  55         memb = kmalloc(sizeof(struct dlm_member), GFP_KERNEL);
  56         if (!memb)
  57                 return -ENOMEM;
  58
  59         w = dlm_node_weight(ls->ls_name, nodeid);
  60         if (w < 0)
  61                 return w;
  62
  63         memb->nodeid = nodeid;
  64         memb->weight = w;
  65         add_ordered_member(ls, memb);
  66         ls->ls_num_nodes++;
  67         return 0;
  68 }
  69
  70 static void dlm_remove_member(struct dlm_ls *ls, struct dlm_member *memb)
  71 {
  72         list_move(&memb->list, &ls->ls_nodes_gone);
  73         ls->ls_num_nodes--;
  74 }
  75
  76 static int dlm_is_member(struct dlm_ls *ls, int nodeid)
  77 {
  78         struct dlm_member *memb;
  79
  80         list_for_each_entry(memb, &ls->ls_nodes, list) {
  81                 if (memb->nodeid == nodeid)
  82                         return TRUE;
  83         }
  84         return FALSE;
  85 }
  86
  87 int dlm_is_removed(struct dlm_ls *ls, int nodeid)
  88 {
  89         struct dlm_member *memb;
  90
  91         list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
  92                 if (memb->nodeid == nodeid)
  93                         return TRUE;
  94         }
  95         return FALSE;
  96 }
  97
  98 static void clear_memb_list(struct list_head *head)
  99 {
 100         struct dlm_member *memb;
 101
 102         while (!list_empty(head)) {
 103                 memb = list_entry(head->next, struct dlm_member, list);
 104                 list_del(&memb->list);
 105                 kfree(memb);
 106         }
 107 }
 108
 109 void dlm_clear_members(struct dlm_ls *ls)
 110 {
 111         clear_memb_list(&ls->ls_nodes);
 112         ls->ls_num_nodes = 0;
 113 }
 114
 115 void dlm_clear_members_gone(struct dlm_ls *ls)
 116 {
 117         clear_memb_list(&ls->ls_nodes_gone);
 118 }
 119
 120 static void make_member_array(struct dlm_ls *ls)
 121 {
 122         struct dlm_member *memb;
 123         int i, w, x = 0, total = 0, all_zero = 0, *array;
 124
 125         kfree(ls->ls_node_array);
 126         ls->ls_node_array = NULL;
 127
 128         list_for_each_entry(memb, &ls->ls_nodes, list) {
 129                 if (memb->weight)
 130                         total += memb->weight;
 131         }
 132
 133         /* all nodes revert to weight of 1 if all have weight 0 */
 134
 135         if (!total) {
 136                 total = ls->ls_num_nodes;
 137                 all_zero = 1;
 138         }
 139
 140         ls->ls_total_weight = total;
 141
 142         array = kmalloc(sizeof(int) * total, GFP_KERNEL);
 143         if (!array)
 144                 return;
 145
 146         list_for_each_entry(memb, &ls->ls_nodes, list) {
 147                 if (!all_zero && !memb->weight)
 148                         continue;
 149
 150                 if (all_zero)
 151                         w = 1;
 152                 else
 153                         w = memb->weight;
 154
 155                 DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
 156
 157                 for (i = 0; i < w; i++)
 158                         array[x++] = memb->nodeid;
 159         }
 160
 161         ls->ls_node_array = array;
 162 }
 163
 164 /* send a status request to all members just to establish comms connections */
 165
 166 static void ping_members(struct dlm_ls *ls)
 167 {
 168         struct dlm_member *memb;
 169         list_for_each_entry(memb, &ls->ls_nodes, list)
 170                 dlm_rcom_status(ls, memb->nodeid);
 171 }
 172
 173 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
 174 {
 175         struct dlm_member *memb, *safe;
 176         int i, error, found, pos = 0, neg = 0, low = -1;
 177
 178         /* move departed members from ls_nodes to ls_nodes_gone */
 179
 180         list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
 181                 found = FALSE;
 182                 for (i = 0; i < rv->node_count; i++) {
 183                         if (memb->nodeid == rv->nodeids[i]) {
 184                                 found = TRUE;
 185                                 break;
 186                         }
 187                 }
 188
 189                 if (!found) {
 190                         neg++;
 191                         dlm_remove_member(ls, memb);
 192                         log_debug(ls, "remove member %d", memb->nodeid);
 193                 }
 194         }
 195
 196         /* add new members to ls_nodes */
 197
 198         for (i = 0; i < rv->node_count; i++) {
 199                 if (dlm_is_member(ls, rv->nodeids[i]))
 200                         continue;
 201                 dlm_add_member(ls, rv->nodeids[i]);
 202                 pos++;
 203                 log_debug(ls, "add member %d", rv->nodeids[i]);
 204         }
 205
 206         list_for_each_entry(memb, &ls->ls_nodes, list) {
 207                 if (low == -1 || memb->nodeid < low)
 208                         low = memb->nodeid;
 209         }
 210         ls->ls_low_nodeid = low;
 211
 212         make_member_array(ls);
 213         dlm_set_recover_status(ls, DLM_RS_NODES);
 214         *neg_out = neg;
 215
 216         ping_members(ls);
 217
 218         error = dlm_recover_members_wait(ls);
 219         log_debug(ls, "total members %d", ls->ls_num_nodes);
 220         return error;
 221 }
 222
 223 /*
 224  * Following called from lockspace.c
 225  */
 226
 227 int dlm_ls_stop(struct dlm_ls *ls)
 228 {
 229         int new;
 230
 231         /*
 232          * A stop cancels any recovery that's in progress (see RECOVERY_STOP,
 233          * dlm_recovery_stopped()) and prevents any new locks from being
 234          * processed (see RUNNING, dlm_locking_stopped()).
 235          */
 236
 237         spin_lock(&ls->ls_recover_lock);
 238         set_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
 239         new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
 240         ls->ls_recover_seq++;
 241         spin_unlock(&ls->ls_recover_lock);
 242
 243         /*
 244          * This in_recovery lock does two things:
 245          *
 246          * 1) Keeps this function from returning until all threads are out
 247          *    of locking routines and locking is truely stopped.
 248          * 2) Keeps any new requests from being processed until it's unlocked
 249          *    when recovery is complete.
 250          */
 251
 252         if (new)
 253                 down_write(&ls->ls_in_recovery);
 254
 255         /*
 256          * The recoverd suspend/resume makes sure that dlm_recoverd (if
 257          * running) has noticed the clearing of RUNNING above and quit
 258          * processing the previous recovery.  This will be true for all nodes
 259          * before any nodes start the new recovery.
 260          */
 261
 262         dlm_recoverd_suspend(ls);
 263         ls->ls_recover_status = 0;
 264         dlm_recoverd_resume(ls);
 265         return 0;
 266 }
 267
 268 int dlm_ls_start(struct dlm_ls *ls)
 269 {
 270         struct dlm_recover *rv = NULL, *rv_old;
 271         int *ids = NULL;
 272         int error, count;
 273
 274         rv = kmalloc(sizeof(struct dlm_recover), GFP_KERNEL);
 275         if (!rv)
 276                 return -ENOMEM;
 277         memset(rv, 0, sizeof(struct dlm_recover));
 278
 279         error = count = dlm_nodeid_list(ls->ls_name, &ids);
 280         if (error <= 0)
 281                 goto fail;
 282
 283         spin_lock(&ls->ls_recover_lock);
 284
 285         /* the lockspace needs to be stopped before it can be started */
 286
 287         if (!dlm_locking_stopped(ls)) {
 288                 spin_unlock(&ls->ls_recover_lock);
 289                 log_error(ls, "start ignored: lockspace running");
 290                 error = -EINVAL;
 291                 goto fail;
 292         }
 293
 294         rv->nodeids = ids;
 295         rv->node_count = count;
 296         rv->seq = ++ls->ls_recover_seq;
 297         rv_old = ls->ls_recover_args;
 298         ls->ls_recover_args = rv;
 299         spin_unlock(&ls->ls_recover_lock);
 300
 301         if (rv_old) {
 302                 kfree(rv_old->nodeids);
 303                 kfree(rv_old);
 304         }
 305
 306         dlm_recoverd_kick(ls);
 307         return 0;
 308
 309  fail:
 310         kfree(rv);
 311         kfree(ids);
 312         return error;
 313 }
 314