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

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) 2005-2008 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 "rcom.h"
  19 #include "config.h"
  20
  21 static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
  22 {
  23         struct dlm_member *memb = NULL;
  24         struct list_head *tmp;
  25         struct list_head *newlist = &new->list;
  26         struct list_head *head = &ls->ls_nodes;
  27
  28         list_for_each(tmp, head) {
  29                 memb = list_entry(tmp, struct dlm_member, list);
  30                 if (new->nodeid < memb->nodeid)
  31                         break;
  32         }
  33
  34         if (!memb)
  35                 list_add_tail(newlist, head);
  36         else {
  37                 /* FIXME: can use list macro here */
  38                 newlist->prev = tmp->prev;
  39                 newlist->next = tmp;
  40                 tmp->prev->next = newlist;
  41                 tmp->prev = newlist;
  42         }
  43 }
  44
  45 static int dlm_add_member(struct dlm_ls *ls, int nodeid)
  46 {
  47         struct dlm_member *memb;
  48         int w;
  49
  50         memb = kzalloc(sizeof(struct dlm_member), GFP_KERNEL);
  51         if (!memb)
  52                 return -ENOMEM;
  53
  54         w = dlm_node_weight(ls->ls_name, nodeid);
  55         if (w < 0) {
  56                 kfree(memb);
  57                 return w;
  58         }
  59
  60         memb->nodeid = nodeid;
  61         memb->weight = w;
  62         add_ordered_member(ls, memb);
  63         ls->ls_num_nodes++;
  64         return 0;
  65 }
  66
  67 static void dlm_remove_member(struct dlm_ls *ls, struct dlm_member *memb)
  68 {
  69         list_move(&memb->list, &ls->ls_nodes_gone);
  70         ls->ls_num_nodes--;
  71 }
  72
  73 int dlm_is_member(struct dlm_ls *ls, int nodeid)
  74 {
  75         struct dlm_member *memb;
  76
  77         list_for_each_entry(memb, &ls->ls_nodes, list) {
  78                 if (memb->nodeid == nodeid)
  79                         return 1;
  80         }
  81         return 0;
  82 }
  83
  84 int dlm_is_removed(struct dlm_ls *ls, int nodeid)
  85 {
  86         struct dlm_member *memb;
  87
  88         list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
  89                 if (memb->nodeid == nodeid)
  90                         return 1;
  91         }
  92         return 0;
  93 }
  94
  95 static void clear_memb_list(struct list_head *head)
  96 {
  97         struct dlm_member *memb;
  98
  99         while (!list_empty(head)) {
 100                 memb = list_entry(head->next, struct dlm_member, list);
 101                 list_del(&memb->list);
 102                 kfree(memb);
 103         }
 104 }
 105
 106 void dlm_clear_members(struct dlm_ls *ls)
 107 {
 108         clear_memb_list(&ls->ls_nodes);
 109         ls->ls_num_nodes = 0;
 110 }
 111
 112 void dlm_clear_members_gone(struct dlm_ls *ls)
 113 {
 114         clear_memb_list(&ls->ls_nodes_gone);
 115 }
 116
 117 static void make_member_array(struct dlm_ls *ls)
 118 {
 119         struct dlm_member *memb;
 120         int i, w, x = 0, total = 0, all_zero = 0, *array;
 121
 122         kfree(ls->ls_node_array);
 123         ls->ls_node_array = NULL;
 124
 125         list_for_each_entry(memb, &ls->ls_nodes, list) {
 126                 if (memb->weight)
 127                         total += memb->weight;
 128         }
 129
 130         /* all nodes revert to weight of 1 if all have weight 0 */
 131
 132         if (!total) {
 133                 total = ls->ls_num_nodes;
 134                 all_zero = 1;
 135         }
 136
 137         ls->ls_total_weight = total;
 138
 139         array = kmalloc(sizeof(int) * total, GFP_KERNEL);
 140         if (!array)
 141                 return;
 142
 143         list_for_each_entry(memb, &ls->ls_nodes, list) {
 144                 if (!all_zero && !memb->weight)
 145                         continue;
 146
 147                 if (all_zero)
 148                         w = 1;
 149                 else
 150                         w = memb->weight;
 151
 152                 DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
 153
 154                 for (i = 0; i < w; i++)
 155                         array[x++] = memb->nodeid;
 156         }
 157
 158         ls->ls_node_array = array;
 159 }
 160
 161 /* send a status request to all members just to establish comms connections */
 162
 163 static int ping_members(struct dlm_ls *ls)
 164 {
 165         struct dlm_member *memb;
 166         int error = 0;
 167
 168         list_for_each_entry(memb, &ls->ls_nodes, list) {
 169                 error = dlm_recovery_stopped(ls);
 170                 if (error)
 171                         break;
 172                 error = dlm_rcom_status(ls, memb->nodeid);
 173                 if (error)
 174                         break;
 175         }
 176         if (error)
 177                 log_debug(ls, "ping_members aborted %d last nodeid %d",
 178                           error, ls->ls_recover_nodeid);
 179         return error;
 180 }
 181
 182 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
 183 {
 184         struct dlm_member *memb, *safe;
 185         int i, error, found, pos = 0, neg = 0, low = -1;
 186
 187         /* previously removed members that we've not finished removing need to
 188            count as a negative change so the "neg" recovery steps will happen */
 189
 190         list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
 191                 log_debug(ls, "prev removed member %d", memb->nodeid);
 192                 neg++;
 193         }
 194
 195         /* move departed members from ls_nodes to ls_nodes_gone */
 196
 197         list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
 198                 found = 0;
 199                 for (i = 0; i < rv->node_count; i++) {
 200                         if (memb->nodeid == rv->nodeids[i]) {
 201                                 found = 1;
 202                                 break;
 203                         }
 204                 }
 205
 206                 if (!found) {
 207                         neg++;
 208                         dlm_remove_member(ls, memb);
 209                         log_debug(ls, "remove member %d", memb->nodeid);
 210                 }
 211         }
 212
 213         /* add new members to ls_nodes */
 214
 215         for (i = 0; i < rv->node_count; i++) {
 216                 if (dlm_is_member(ls, rv->nodeids[i]))
 217                         continue;
 218                 dlm_add_member(ls, rv->nodeids[i]);
 219                 pos++;
 220                 log_debug(ls, "add member %d", rv->nodeids[i]);
 221         }
 222
 223         list_for_each_entry(memb, &ls->ls_nodes, list) {
 224                 if (low == -1 || memb->nodeid < low)
 225                         low = memb->nodeid;
 226         }
 227         ls->ls_low_nodeid = low;
 228
 229         make_member_array(ls);
 230         dlm_set_recover_status(ls, DLM_RS_NODES);
 231         *neg_out = neg;
 232
 233         error = ping_members(ls);
 234         if (!error || error == -EPROTO) {
 235                 /* new_lockspace() may be waiting to know if the config
 236                    is good or bad */
 237                 ls->ls_members_result = error;
 238                 complete(&ls->ls_members_done);
 239         }
 240         if (error)
 241                 goto out;
 242
 243         error = dlm_recover_members_wait(ls);
 244  out:
 245         log_debug(ls, "total members %d error %d", ls->ls_num_nodes, error);
 246         return error;
 247 }
 248
 249 /* Userspace guarantees that dlm_ls_stop() has completed on all nodes before
 250    dlm_ls_start() is called on any of them to start the new recovery. */
 251
 252 int dlm_ls_stop(struct dlm_ls *ls)
 253 {
 254         int new;
 255
 256         /*
 257          * Prevent dlm_recv from being in the middle of something when we do
 258          * the stop.  This includes ensuring dlm_recv isn't processing a
 259          * recovery message (rcom), while dlm_recoverd is aborting and
 260          * resetting things from an in-progress recovery.  i.e. we want
 261          * dlm_recoverd to abort its recovery without worrying about dlm_recv
 262          * processing an rcom at the same time.  Stopping dlm_recv also makes
 263          * it easy for dlm_receive_message() to check locking stopped and add a
 264          * message to the requestqueue without races.
 265          */
 266
 267         down_write(&ls->ls_recv_active);
 268
 269         /*
 270          * Abort any recovery that's in progress (see RECOVERY_STOP,
 271          * dlm_recovery_stopped()) and tell any other threads running in the
 272          * dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
 273          */
 274
 275         spin_lock(&ls->ls_recover_lock);
 276         set_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
 277         new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
 278         ls->ls_recover_seq++;
 279         spin_unlock(&ls->ls_recover_lock);
 280
 281         /*
 282          * Let dlm_recv run again, now any normal messages will be saved on the
 283          * requestqueue for later.
 284          */
 285
 286         up_write(&ls->ls_recv_active);
 287
 288         /*
 289          * This in_recovery lock does two things:
 290          * 1) Keeps this function from returning until all threads are out
 291          *    of locking routines and locking is truely stopped.
 292          * 2) Keeps any new requests from being processed until it's unlocked
 293          *    when recovery is complete.
 294          */
 295
 296         if (new)
 297                 down_write(&ls->ls_in_recovery);
 298
 299         /*
 300          * The recoverd suspend/resume makes sure that dlm_recoverd (if
 301          * running) has noticed RECOVERY_STOP above and quit processing the
 302          * previous recovery.
 303          */
 304
 305         dlm_recoverd_suspend(ls);
 306         ls->ls_recover_status = 0;
 307         dlm_recoverd_resume(ls);
 308
 309         if (!ls->ls_recover_begin)
 310                 ls->ls_recover_begin = jiffies;
 311         return 0;
 312 }
 313
 314 int dlm_ls_start(struct dlm_ls *ls)
 315 {
 316         struct dlm_recover *rv = NULL, *rv_old;
 317         int *ids = NULL;
 318         int error, count;
 319
 320         rv = kzalloc(sizeof(struct dlm_recover), GFP_KERNEL);
 321         if (!rv)
 322                 return -ENOMEM;
 323
 324         error = count = dlm_nodeid_list(ls->ls_name, &ids);
 325         if (error <= 0)
 326                 goto fail;
 327
 328         spin_lock(&ls->ls_recover_lock);
 329
 330         /* the lockspace needs to be stopped before it can be started */
 331
 332         if (!dlm_locking_stopped(ls)) {
 333                 spin_unlock(&ls->ls_recover_lock);
 334                 log_error(ls, "start ignored: lockspace running");
 335                 error = -EINVAL;
 336                 goto fail;
 337         }
 338
 339         rv->nodeids = ids;
 340         rv->node_count = count;
 341         rv->seq = ++ls->ls_recover_seq;
 342         rv_old = ls->ls_recover_args;
 343         ls->ls_recover_args = rv;
 344         spin_unlock(&ls->ls_recover_lock);
 345
 346         if (rv_old) {
 347                 kfree(rv_old->nodeids);
 348                 kfree(rv_old);
 349         }
 350
 351         dlm_recoverd_kick(ls);
 352         return 0;
 353
 354  fail:
 355         kfree(rv);
 356         kfree(ids);
 357         return error;
 358 }
 359