From e7fd41792fc0ee52a05fcaac87511f118328d147 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Wed, 18 Jan 2006 09:30:29 +0000 Subject: [DLM] The core of the DLM for GFS2/CLVM This is the core of the distributed lock manager which is required to use GFS2 as a cluster filesystem. It is also used by CLVM and can be used as a standalone lock manager independantly of either of these two projects. It implements VAX-style locking modes. Signed-off-by: David Teigland Signed-off-by: Steve Whitehouse --- fs/dlm/member.c | 314 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 314 insertions(+) create mode 100644 fs/dlm/member.c (limited to 'fs/dlm/member.c') diff --git a/fs/dlm/member.c b/fs/dlm/member.c new file mode 100644 index 00000000000..439249b62a5 --- /dev/null +++ b/fs/dlm/member.c @@ -0,0 +1,314 @@ +/****************************************************************************** +******************************************************************************* +** +** Copyright (C) 2005 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 "lowcomms.h" +#include "rcom.h" +#include "config.h" + +/* + * Following called by dlm_recoverd thread + */ + +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 = kmalloc(sizeof(struct dlm_member), GFP_KERNEL); + if (!memb) + return -ENOMEM; + + w = dlm_node_weight(ls->ls_name, nodeid); + if (w < 0) + 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--; +} + +static 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 TRUE; + } + return FALSE; +} + +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 TRUE; + } + return FALSE; +} + +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 void ping_members(struct dlm_ls *ls) +{ + struct dlm_member *memb; + list_for_each_entry(memb, &ls->ls_nodes, list) + dlm_rcom_status(ls, memb->nodeid); +} + +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; + + /* move departed members from ls_nodes to ls_nodes_gone */ + + list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) { + found = FALSE; + for (i = 0; i < rv->node_count; i++) { + if (memb->nodeid == rv->nodeids[i]) { + found = TRUE; + break; + } + } + + if (!found) { + neg++; + dlm_remove_member(ls, memb); + log_debug(ls, "remove member %d", memb->nodeid); + } + } + + /* 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; + + ping_members(ls); + + error = dlm_recover_members_wait(ls); + log_debug(ls, "total members %d", ls->ls_num_nodes); + return error; +} + +/* + * Following called from lockspace.c + */ + +int dlm_ls_stop(struct dlm_ls *ls) +{ + int new; + + /* + * A stop cancels any recovery that's in progress (see RECOVERY_STOP, + * dlm_recovery_stopped()) and prevents any new locks from being + * processed (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); + + /* + * 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 the clearing of RUNNING above and quit + * processing the previous recovery. This will be true for all nodes + * before any nodes start the new recovery. + */ + + dlm_recoverd_suspend(ls); + ls->ls_recover_status = 0; + dlm_recoverd_resume(ls); + return 0; +} + +int dlm_ls_start(struct dlm_ls *ls) +{ + struct dlm_recover *rv = NULL, *rv_old; + int *ids = NULL; + int error, count; + + rv = kmalloc(sizeof(struct dlm_recover), GFP_KERNEL); + if (!rv) + return -ENOMEM; + memset(rv, 0, sizeof(struct dlm_recover)); + + error = count = dlm_nodeid_list(ls->ls_name, &ids); + 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 = 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) { + kfree(rv_old->nodeids); + kfree(rv_old); + } + + dlm_recoverd_kick(ls); + return 0; + + fail: + kfree(rv); + kfree(ids); + return error; +} + -- cgit v1.2.3