linux/fs/dlm/member.c
David Teigland d44e0fc704 dlm: recover nodes that are removed and re-added
If a node is removed from a lockspace, and then added back before the
dlm is notified of the removal, the dlm will not detect the removal
and won't clear the old state from the node.  This is fixed by using a
list of added nodes so the membership recovery can detect when a newly
added node is already in the member list.

Signed-off-by: David Teigland <teigland@redhat.com>
2008-04-21 11:18:01 -05:00

384 lines
8.9 KiB
C

/******************************************************************************
*******************************************************************************
**
** Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
** of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/
#include "dlm_internal.h"
#include "lockspace.h"
#include "member.h"
#include "recoverd.h"
#include "recover.h"
#include "rcom.h"
#include "config.h"
static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
{
struct dlm_member *memb = NULL;
struct list_head *tmp;
struct list_head *newlist = &new->list;
struct list_head *head = &ls->ls_nodes;
list_for_each(tmp, head) {
memb = list_entry(tmp, struct dlm_member, list);
if (new->nodeid < memb->nodeid)
break;
}
if (!memb)
list_add_tail(newlist, head);
else {
/* FIXME: can use list macro here */
newlist->prev = tmp->prev;
newlist->next = tmp;
tmp->prev->next = newlist;
tmp->prev = newlist;
}
}
static int dlm_add_member(struct dlm_ls *ls, int nodeid)
{
struct dlm_member *memb;
int w;
memb = kzalloc(sizeof(struct dlm_member), GFP_KERNEL);
if (!memb)
return -ENOMEM;
w = dlm_node_weight(ls->ls_name, nodeid);
if (w < 0) {
kfree(memb);
return w;
}
memb->nodeid = nodeid;
memb->weight = w;
add_ordered_member(ls, memb);
ls->ls_num_nodes++;
return 0;
}
static void dlm_remove_member(struct dlm_ls *ls, struct dlm_member *memb)
{
list_move(&memb->list, &ls->ls_nodes_gone);
ls->ls_num_nodes--;
}
int dlm_is_member(struct dlm_ls *ls, int nodeid)
{
struct dlm_member *memb;
list_for_each_entry(memb, &ls->ls_nodes, list) {
if (memb->nodeid == nodeid)
return 1;
}
return 0;
}
int dlm_is_removed(struct dlm_ls *ls, int nodeid)
{
struct dlm_member *memb;
list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
if (memb->nodeid == nodeid)
return 1;
}
return 0;
}
static void clear_memb_list(struct list_head *head)
{
struct dlm_member *memb;
while (!list_empty(head)) {
memb = list_entry(head->next, struct dlm_member, list);
list_del(&memb->list);
kfree(memb);
}
}
void dlm_clear_members(struct dlm_ls *ls)
{
clear_memb_list(&ls->ls_nodes);
ls->ls_num_nodes = 0;
}
void dlm_clear_members_gone(struct dlm_ls *ls)
{
clear_memb_list(&ls->ls_nodes_gone);
}
static void make_member_array(struct dlm_ls *ls)
{
struct dlm_member *memb;
int i, w, x = 0, total = 0, all_zero = 0, *array;
kfree(ls->ls_node_array);
ls->ls_node_array = NULL;
list_for_each_entry(memb, &ls->ls_nodes, list) {
if (memb->weight)
total += memb->weight;
}
/* all nodes revert to weight of 1 if all have weight 0 */
if (!total) {
total = ls->ls_num_nodes;
all_zero = 1;
}
ls->ls_total_weight = total;
array = kmalloc(sizeof(int) * total, GFP_KERNEL);
if (!array)
return;
list_for_each_entry(memb, &ls->ls_nodes, list) {
if (!all_zero && !memb->weight)
continue;
if (all_zero)
w = 1;
else
w = memb->weight;
DLM_ASSERT(x < total, printk("total %d x %d\n", total, x););
for (i = 0; i < w; i++)
array[x++] = memb->nodeid;
}
ls->ls_node_array = array;
}
/* send a status request to all members just to establish comms connections */
static int ping_members(struct dlm_ls *ls)
{
struct dlm_member *memb;
int error = 0;
list_for_each_entry(memb, &ls->ls_nodes, list) {
error = dlm_recovery_stopped(ls);
if (error)
break;
error = dlm_rcom_status(ls, memb->nodeid);
if (error)
break;
}
if (error)
log_debug(ls, "ping_members aborted %d last nodeid %d",
error, ls->ls_recover_nodeid);
return error;
}
int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
{
struct dlm_member *memb, *safe;
int i, error, found, pos = 0, neg = 0, low = -1;
/* previously removed members that we've not finished removing need to
count as a negative change so the "neg" recovery steps will happen */
list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
log_debug(ls, "prev removed member %d", memb->nodeid);
neg++;
}
/* move departed members from ls_nodes to ls_nodes_gone */
list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
found = 0;
for (i = 0; i < rv->node_count; i++) {
if (memb->nodeid == rv->nodeids[i]) {
found = 1;
break;
}
}
if (!found) {
neg++;
dlm_remove_member(ls, memb);
log_debug(ls, "remove member %d", memb->nodeid);
}
}
/* Add an entry to ls_nodes_gone for members that were removed and
then added again, so that previous state for these nodes will be
cleared during recovery. */
for (i = 0; i < rv->new_count; i++) {
if (!dlm_is_member(ls, rv->new[i]))
continue;
log_debug(ls, "new nodeid %d is a re-added member", rv->new[i]);
memb = kzalloc(sizeof(struct dlm_member), GFP_KERNEL);
if (!memb)
return -ENOMEM;
memb->nodeid = rv->new[i];
list_add_tail(&memb->list, &ls->ls_nodes_gone);
neg++;
}
/* add new members to ls_nodes */
for (i = 0; i < rv->node_count; i++) {
if (dlm_is_member(ls, rv->nodeids[i]))
continue;
dlm_add_member(ls, rv->nodeids[i]);
pos++;
log_debug(ls, "add member %d", rv->nodeids[i]);
}
list_for_each_entry(memb, &ls->ls_nodes, list) {
if (low == -1 || memb->nodeid < low)
low = memb->nodeid;
}
ls->ls_low_nodeid = low;
make_member_array(ls);
dlm_set_recover_status(ls, DLM_RS_NODES);
*neg_out = neg;
error = ping_members(ls);
if (!error || error == -EPROTO) {
/* new_lockspace() may be waiting to know if the config
is good or bad */
ls->ls_members_result = error;
complete(&ls->ls_members_done);
}
if (error)
goto out;
error = dlm_recover_members_wait(ls);
out:
log_debug(ls, "total members %d error %d", ls->ls_num_nodes, error);
return error;
}
/* Userspace guarantees that dlm_ls_stop() has completed on all nodes before
dlm_ls_start() is called on any of them to start the new recovery. */
int dlm_ls_stop(struct dlm_ls *ls)
{
int new;
/*
* Prevent dlm_recv from being in the middle of something when we do
* the stop. This includes ensuring dlm_recv isn't processing a
* recovery message (rcom), while dlm_recoverd is aborting and
* resetting things from an in-progress recovery. i.e. we want
* dlm_recoverd to abort its recovery without worrying about dlm_recv
* processing an rcom at the same time. Stopping dlm_recv also makes
* it easy for dlm_receive_message() to check locking stopped and add a
* message to the requestqueue without races.
*/
down_write(&ls->ls_recv_active);
/*
* Abort any recovery that's in progress (see RECOVERY_STOP,
* dlm_recovery_stopped()) and tell any other threads running in the
* dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
*/
spin_lock(&ls->ls_recover_lock);
set_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
ls->ls_recover_seq++;
spin_unlock(&ls->ls_recover_lock);
/*
* Let dlm_recv run again, now any normal messages will be saved on the
* requestqueue for later.
*/
up_write(&ls->ls_recv_active);
/*
* This in_recovery lock does two things:
* 1) Keeps this function from returning until all threads are out
* of locking routines and locking is truely stopped.
* 2) Keeps any new requests from being processed until it's unlocked
* when recovery is complete.
*/
if (new)
down_write(&ls->ls_in_recovery);
/*
* The recoverd suspend/resume makes sure that dlm_recoverd (if
* running) has noticed RECOVERY_STOP above and quit processing the
* previous recovery.
*/
dlm_recoverd_suspend(ls);
ls->ls_recover_status = 0;
dlm_recoverd_resume(ls);
if (!ls->ls_recover_begin)
ls->ls_recover_begin = jiffies;
return 0;
}
int dlm_ls_start(struct dlm_ls *ls)
{
struct dlm_recover *rv = NULL, *rv_old;
int *ids = NULL, *new = NULL;
int error, ids_count = 0, new_count = 0;
rv = kzalloc(sizeof(struct dlm_recover), GFP_KERNEL);
if (!rv)
return -ENOMEM;
error = dlm_nodeid_list(ls->ls_name, &ids, &ids_count,
&new, &new_count);
if (error < 0)
goto fail;
spin_lock(&ls->ls_recover_lock);
/* the lockspace needs to be stopped before it can be started */
if (!dlm_locking_stopped(ls)) {
spin_unlock(&ls->ls_recover_lock);
log_error(ls, "start ignored: lockspace running");
error = -EINVAL;
goto fail;
}
rv->nodeids = ids;
rv->node_count = ids_count;
rv->new = new;
rv->new_count = new_count;
rv->seq = ++ls->ls_recover_seq;
rv_old = ls->ls_recover_args;
ls->ls_recover_args = rv;
spin_unlock(&ls->ls_recover_lock);
if (rv_old) {
log_error(ls, "unused recovery %llx %d",
(unsigned long long)rv_old->seq, rv_old->node_count);
kfree(rv_old->nodeids);
kfree(rv_old->new);
kfree(rv_old);
}
dlm_recoverd_kick(ls);
return 0;
fail:
kfree(rv);
kfree(ids);
kfree(new);
return error;
}