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linux-sg2042/fs/ocfs2/dlm/dlmrecovery.c

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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dlmrecovery.c
*
* recovery stuff
*
* Copyright (C) 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/random.h>
#include <linux/blkdev.h>
#include <linux/socket.h>
#include <linux/inet.h>
#include <linux/timer.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include "cluster/heartbeat.h"
#include "cluster/nodemanager.h"
#include "cluster/tcp.h"
#include "dlmapi.h"
#include "dlmcommon.h"
#include "dlmdomain.h"
#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
#include "cluster/masklog.h"
static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
static int dlm_recovery_thread(void *data);
static int dlm_do_recovery(struct dlm_ctxt *dlm);
static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
static int dlm_request_all_locks(struct dlm_ctxt *dlm,
u8 request_from, u8 dead_node);
static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
const char *lockname, int namelen,
int total_locks, u64 cookie,
u8 flags, u8 master);
static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
struct dlm_migratable_lockres *mres,
u8 send_to,
struct dlm_lock_resource *res,
int total_locks);
static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_migratable_lockres *mres);
static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
u8 dead_node, u8 send_to);
static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
struct list_head *list, u8 dead_node);
static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
u8 dead_node, u8 new_master);
static void dlm_reco_ast(void *astdata);
static void dlm_reco_bast(void *astdata, int blocked_type);
static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
static void dlm_request_all_locks_worker(struct dlm_work_item *item,
void *data);
static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
u8 *real_master);
static u64 dlm_get_next_mig_cookie(void);
static DEFINE_SPINLOCK(dlm_reco_state_lock);
static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
static u64 dlm_mig_cookie = 1;
static u64 dlm_get_next_mig_cookie(void)
{
u64 c;
spin_lock(&dlm_mig_cookie_lock);
c = dlm_mig_cookie;
if (dlm_mig_cookie == (~0ULL))
dlm_mig_cookie = 1;
else
dlm_mig_cookie++;
spin_unlock(&dlm_mig_cookie_lock);
return c;
}
static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
u8 dead_node)
{
assert_spin_locked(&dlm->spinlock);
if (dlm->reco.dead_node != dead_node)
mlog(0, "%s: changing dead_node from %u to %u\n",
dlm->name, dlm->reco.dead_node, dead_node);
dlm->reco.dead_node = dead_node;
}
static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
u8 master)
{
assert_spin_locked(&dlm->spinlock);
mlog(0, "%s: changing new_master from %u to %u\n",
dlm->name, dlm->reco.new_master, master);
dlm->reco.new_master = master;
}
static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
{
assert_spin_locked(&dlm->spinlock);
clear_bit(dlm->reco.dead_node, dlm->recovery_map);
dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
}
static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
{
spin_lock(&dlm->spinlock);
__dlm_reset_recovery(dlm);
spin_unlock(&dlm->spinlock);
}
/* Worker function used during recovery. */
void dlm_dispatch_work(struct work_struct *work)
{
struct dlm_ctxt *dlm =
container_of(work, struct dlm_ctxt, dispatched_work);
LIST_HEAD(tmp_list);
struct dlm_work_item *item, *next;
dlm_workfunc_t *workfunc;
int tot=0;
spin_lock(&dlm->work_lock);
list_splice_init(&dlm->work_list, &tmp_list);
spin_unlock(&dlm->work_lock);
list_for_each_entry(item, &tmp_list, list) {
tot++;
}
mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
list_for_each_entry_safe(item, next, &tmp_list, list) {
workfunc = item->func;
list_del_init(&item->list);
/* already have ref on dlm to avoid having
* it disappear. just double-check. */
BUG_ON(item->dlm != dlm);
/* this is allowed to sleep and
* call network stuff */
workfunc(item, item->data);
dlm_put(dlm);
kfree(item);
}
}
/*
* RECOVERY THREAD
*/
void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
{
/* wake the recovery thread
* this will wake the reco thread in one of three places
* 1) sleeping with no recovery happening
* 2) sleeping with recovery mastered elsewhere
* 3) recovery mastered here, waiting on reco data */
wake_up(&dlm->dlm_reco_thread_wq);
}
/* Launch the recovery thread */
int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
{
mlog(0, "starting dlm recovery thread...\n");
dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
"dlm_reco_thread");
if (IS_ERR(dlm->dlm_reco_thread_task)) {
mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
dlm->dlm_reco_thread_task = NULL;
return -EINVAL;
}
return 0;
}
void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
{
if (dlm->dlm_reco_thread_task) {
mlog(0, "waiting for dlm recovery thread to exit\n");
kthread_stop(dlm->dlm_reco_thread_task);
dlm->dlm_reco_thread_task = NULL;
}
}
/*
* this is lame, but here's how recovery works...
* 1) all recovery threads cluster wide will work on recovering
* ONE node at a time
* 2) negotiate who will take over all the locks for the dead node.
* thats right... ALL the locks.
* 3) once a new master is chosen, everyone scans all locks
* and moves aside those mastered by the dead guy
* 4) each of these locks should be locked until recovery is done
* 5) the new master collects up all of secondary lock queue info
* one lock at a time, forcing each node to communicate back
* before continuing
* 6) each secondary lock queue responds with the full known lock info
* 7) once the new master has run all its locks, it sends a ALLDONE!
* message to everyone
* 8) upon receiving this message, the secondary queue node unlocks
* and responds to the ALLDONE
* 9) once the new master gets responses from everyone, he unlocks
* everything and recovery for this dead node is done
*10) go back to 2) while there are still dead nodes
*
*/
static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
{
struct dlm_reco_node_data *ndata;
struct dlm_lock_resource *res;
mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
dlm->reco.dead_node, dlm->reco.new_master);
list_for_each_entry(ndata, &dlm->reco.node_data, list) {
char *st = "unknown";
switch (ndata->state) {
case DLM_RECO_NODE_DATA_INIT:
st = "init";
break;
case DLM_RECO_NODE_DATA_REQUESTING:
st = "requesting";
break;
case DLM_RECO_NODE_DATA_DEAD:
st = "dead";
break;
case DLM_RECO_NODE_DATA_RECEIVING:
st = "receiving";
break;
case DLM_RECO_NODE_DATA_REQUESTED:
st = "requested";
break;
case DLM_RECO_NODE_DATA_DONE:
st = "done";
break;
case DLM_RECO_NODE_DATA_FINALIZE_SENT:
st = "finalize-sent";
break;
default:
st = "bad";
break;
}
mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
dlm->name, ndata->node_num, st);
}
list_for_each_entry(res, &dlm->reco.resources, recovering) {
mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
dlm->name, res->lockname.len, res->lockname.name);
}
}
#define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
static int dlm_recovery_thread(void *data)
{
int status;
struct dlm_ctxt *dlm = data;
unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
mlog(0, "dlm thread running for %s...\n", dlm->name);
while (!kthread_should_stop()) {
if (dlm_domain_fully_joined(dlm)) {
status = dlm_do_recovery(dlm);
if (status == -EAGAIN) {
/* do not sleep, recheck immediately. */
continue;
}
if (status < 0)
mlog_errno(status);
}
wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
kthread_should_stop(),
timeout);
}
mlog(0, "quitting DLM recovery thread\n");
return 0;
}
/* returns true when the recovery master has contacted us */
static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
{
int ready;
spin_lock(&dlm->spinlock);
ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
spin_unlock(&dlm->spinlock);
return ready;
}
/* returns true if node is no longer in the domain
* could be dead or just not joined */
int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
{
int dead;
spin_lock(&dlm->spinlock);
dead = !test_bit(node, dlm->domain_map);
spin_unlock(&dlm->spinlock);
return dead;
}
/* returns true if node is no longer in the domain
* could be dead or just not joined */
static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
{
int recovered;
spin_lock(&dlm->spinlock);
recovered = !test_bit(node, dlm->recovery_map);
spin_unlock(&dlm->spinlock);
return recovered;
}
void dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
{
if (dlm_is_node_dead(dlm, node))
return;
printk(KERN_NOTICE "o2dlm: Waiting on the death of node %u in "
"domain %s\n", node, dlm->name);
if (timeout)
wait_event_timeout(dlm->dlm_reco_thread_wq,
dlm_is_node_dead(dlm, node),
msecs_to_jiffies(timeout));
else
wait_event(dlm->dlm_reco_thread_wq,
dlm_is_node_dead(dlm, node));
}
void dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
{
if (dlm_is_node_recovered(dlm, node))
return;
printk(KERN_NOTICE "o2dlm: Waiting on the recovery of node %u in "
"domain %s\n", node, dlm->name);
if (timeout)
wait_event_timeout(dlm->dlm_reco_thread_wq,
dlm_is_node_recovered(dlm, node),
msecs_to_jiffies(timeout));
else
wait_event(dlm->dlm_reco_thread_wq,
dlm_is_node_recovered(dlm, node));
}
/* callers of the top-level api calls (dlmlock/dlmunlock) should
* block on the dlm->reco.event when recovery is in progress.
* the dlm recovery thread will set this state when it begins
* recovering a dead node (as the new master or not) and clear
* the state and wake as soon as all affected lock resources have
* been marked with the RECOVERY flag */
static int dlm_in_recovery(struct dlm_ctxt *dlm)
{
int in_recovery;
spin_lock(&dlm->spinlock);
in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
spin_unlock(&dlm->spinlock);
return in_recovery;
}
void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
{
if (dlm_in_recovery(dlm)) {
mlog(0, "%s: reco thread %d in recovery: "
"state=%d, master=%u, dead=%u\n",
dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
dlm->reco.state, dlm->reco.new_master,
dlm->reco.dead_node);
}
wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
}
static void dlm_begin_recovery(struct dlm_ctxt *dlm)
{
spin_lock(&dlm->spinlock);
BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node %u\n",
dlm->name, dlm->reco.dead_node);
dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
spin_unlock(&dlm->spinlock);
}
static void dlm_end_recovery(struct dlm_ctxt *dlm)
{
spin_lock(&dlm->spinlock);
BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
spin_unlock(&dlm->spinlock);
printk(KERN_NOTICE "o2dlm: End recovery on domain %s\n", dlm->name);
wake_up(&dlm->reco.event);
}
static void dlm_print_recovery_master(struct dlm_ctxt *dlm)
{
printk(KERN_NOTICE "o2dlm: Node %u (%s) is the Recovery Master for the "
"dead node %u in domain %s\n", dlm->reco.new_master,
(dlm->node_num == dlm->reco.new_master ? "me" : "he"),
dlm->reco.dead_node, dlm->name);
}
static int dlm_do_recovery(struct dlm_ctxt *dlm)
{
int status = 0;
int ret;
spin_lock(&dlm->spinlock);
/* check to see if the new master has died */
if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
test_bit(dlm->reco.new_master, dlm->recovery_map)) {
mlog(0, "new master %u died while recovering %u!\n",
dlm->reco.new_master, dlm->reco.dead_node);
/* unset the new_master, leave dead_node */
dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
}
/* select a target to recover */
if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
int bit;
bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
if (bit >= O2NM_MAX_NODES || bit < 0)
dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
else
dlm_set_reco_dead_node(dlm, bit);
} else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
/* BUG? */
mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
dlm->reco.dead_node);
dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
}
if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
// mlog(0, "nothing to recover! sleeping now!\n");
spin_unlock(&dlm->spinlock);
/* return to main thread loop and sleep. */
return 0;
}
mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
dlm->reco.dead_node);
spin_unlock(&dlm->spinlock);
/* take write barrier */
/* (stops the list reshuffling thread, proxy ast handling) */
dlm_begin_recovery(dlm);
if (dlm->reco.new_master == dlm->node_num)
goto master_here;
if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
/* choose a new master, returns 0 if this node
* is the master, -EEXIST if it's another node.
* this does not return until a new master is chosen
* or recovery completes entirely. */
ret = dlm_pick_recovery_master(dlm);
if (!ret) {
/* already notified everyone. go. */
goto master_here;
}
mlog(0, "another node will master this recovery session.\n");
}
dlm_print_recovery_master(dlm);
/* it is safe to start everything back up here
* because all of the dead node's lock resources
* have been marked as in-recovery */
dlm_end_recovery(dlm);
/* sleep out in main dlm_recovery_thread loop. */
return 0;
master_here:
dlm_print_recovery_master(dlm);
status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
if (status < 0) {
/* we should never hit this anymore */
mlog(ML_ERROR, "%s: Error %d remastering locks for node %u, "
"retrying.\n", dlm->name, status, dlm->reco.dead_node);
/* yield a bit to allow any final network messages
* to get handled on remaining nodes */
msleep(100);
} else {
/* success! see if any other nodes need recovery */
mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
dlm->name, dlm->reco.dead_node, dlm->node_num);
dlm_reset_recovery(dlm);
}
dlm_end_recovery(dlm);
/* continue and look for another dead node */
return -EAGAIN;
}
static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
{
int status = 0;
struct dlm_reco_node_data *ndata;
int all_nodes_done;
int destroy = 0;
int pass = 0;
do {
/* we have become recovery master. there is no escaping
* this, so just keep trying until we get it. */
status = dlm_init_recovery_area(dlm, dead_node);
if (status < 0) {
mlog(ML_ERROR, "%s: failed to alloc recovery area, "
"retrying\n", dlm->name);
msleep(1000);
}
} while (status != 0);
/* safe to access the node data list without a lock, since this
* process is the only one to change the list */
list_for_each_entry(ndata, &dlm->reco.node_data, list) {
BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
mlog(0, "%s: Requesting lock info from node %u\n", dlm->name,
ndata->node_num);
if (ndata->node_num == dlm->node_num) {
ndata->state = DLM_RECO_NODE_DATA_DONE;
continue;
}
do {
status = dlm_request_all_locks(dlm, ndata->node_num,
dead_node);
if (status < 0) {
mlog_errno(status);
if (dlm_is_host_down(status)) {
/* node died, ignore it for recovery */
status = 0;
ndata->state = DLM_RECO_NODE_DATA_DEAD;
/* wait for the domain map to catch up
* with the network state. */
wait_event_timeout(dlm->dlm_reco_thread_wq,
dlm_is_node_dead(dlm,
ndata->node_num),
msecs_to_jiffies(1000));
mlog(0, "waited 1 sec for %u, "
"dead? %s\n", ndata->node_num,
dlm_is_node_dead(dlm, ndata->node_num) ?
"yes" : "no");
} else {
/* -ENOMEM on the other node */
mlog(0, "%s: node %u returned "
"%d during recovery, retrying "
"after a short wait\n",
dlm->name, ndata->node_num,
status);
msleep(100);
}
}
} while (status != 0);
spin_lock(&dlm_reco_state_lock);
switch (ndata->state) {
case DLM_RECO_NODE_DATA_INIT:
case DLM_RECO_NODE_DATA_FINALIZE_SENT:
case DLM_RECO_NODE_DATA_REQUESTED:
BUG();
break;
case DLM_RECO_NODE_DATA_DEAD:
mlog(0, "node %u died after requesting "
"recovery info for node %u\n",
ndata->node_num, dead_node);
/* fine. don't need this node's info.
* continue without it. */
break;
case DLM_RECO_NODE_DATA_REQUESTING:
ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
mlog(0, "now receiving recovery data from "
"node %u for dead node %u\n",
ndata->node_num, dead_node);
break;
case DLM_RECO_NODE_DATA_RECEIVING:
mlog(0, "already receiving recovery data from "
"node %u for dead node %u\n",
ndata->node_num, dead_node);
break;
case DLM_RECO_NODE_DATA_DONE:
mlog(0, "already DONE receiving recovery data "
"from node %u for dead node %u\n",
ndata->node_num, dead_node);
break;
}
spin_unlock(&dlm_reco_state_lock);
}
mlog(0, "%s: Done requesting all lock info\n", dlm->name);
/* nodes should be sending reco data now
* just need to wait */
while (1) {
/* check all the nodes now to see if we are
* done, or if anyone died */
all_nodes_done = 1;
spin_lock(&dlm_reco_state_lock);
list_for_each_entry(ndata, &dlm->reco.node_data, list) {
mlog(0, "checking recovery state of node %u\n",
ndata->node_num);
switch (ndata->state) {
case DLM_RECO_NODE_DATA_INIT:
case DLM_RECO_NODE_DATA_REQUESTING:
mlog(ML_ERROR, "bad ndata state for "
"node %u: state=%d\n",
ndata->node_num, ndata->state);
BUG();
break;
case DLM_RECO_NODE_DATA_DEAD:
mlog(0, "node %u died after "
"requesting recovery info for "
"node %u\n", ndata->node_num,
dead_node);
break;
case DLM_RECO_NODE_DATA_RECEIVING:
case DLM_RECO_NODE_DATA_REQUESTED:
mlog(0, "%s: node %u still in state %s\n",
dlm->name, ndata->node_num,
ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
"receiving" : "requested");
all_nodes_done = 0;
break;
case DLM_RECO_NODE_DATA_DONE:
mlog(0, "%s: node %u state is done\n",
dlm->name, ndata->node_num);
break;
case DLM_RECO_NODE_DATA_FINALIZE_SENT:
mlog(0, "%s: node %u state is finalize\n",
dlm->name, ndata->node_num);
break;
}
}
spin_unlock(&dlm_reco_state_lock);
mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
all_nodes_done?"yes":"no");
if (all_nodes_done) {
int ret;
/* all nodes are now in DLM_RECO_NODE_DATA_DONE state
* just send a finalize message to everyone and
* clean up */
mlog(0, "all nodes are done! send finalize\n");
ret = dlm_send_finalize_reco_message(dlm);
if (ret < 0)
mlog_errno(ret);
spin_lock(&dlm->spinlock);
dlm_finish_local_lockres_recovery(dlm, dead_node,
dlm->node_num);
spin_unlock(&dlm->spinlock);
mlog(0, "should be done with recovery!\n");
mlog(0, "finishing recovery of %s at %lu, "
"dead=%u, this=%u, new=%u\n", dlm->name,
jiffies, dlm->reco.dead_node,
dlm->node_num, dlm->reco.new_master);
destroy = 1;
status = 0;
/* rescan everything marked dirty along the way */
dlm_kick_thread(dlm, NULL);
break;
}
/* wait to be signalled, with periodic timeout
* to check for node death */
wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
kthread_should_stop(),
msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
}
if (destroy)
dlm_destroy_recovery_area(dlm, dead_node);
return status;
}
static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
{
int num=0;
struct dlm_reco_node_data *ndata;
spin_lock(&dlm->spinlock);
memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
/* nodes can only be removed (by dying) after dropping
* this lock, and death will be trapped later, so this should do */
spin_unlock(&dlm->spinlock);
while (1) {
num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
if (num >= O2NM_MAX_NODES) {
break;
}
BUG_ON(num == dead_node);
ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
if (!ndata) {
dlm_destroy_recovery_area(dlm, dead_node);
return -ENOMEM;
}
ndata->node_num = num;
ndata->state = DLM_RECO_NODE_DATA_INIT;
spin_lock(&dlm_reco_state_lock);
list_add_tail(&ndata->list, &dlm->reco.node_data);
spin_unlock(&dlm_reco_state_lock);
num++;
}
return 0;
}
static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
{
struct dlm_reco_node_data *ndata, *next;
LIST_HEAD(tmplist);
spin_lock(&dlm_reco_state_lock);
list_splice_init(&dlm->reco.node_data, &tmplist);
spin_unlock(&dlm_reco_state_lock);
list_for_each_entry_safe(ndata, next, &tmplist, list) {
list_del_init(&ndata->list);
kfree(ndata);
}
}
static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
u8 dead_node)
{
struct dlm_lock_request lr;
int ret;
int status;
mlog(0, "\n");
mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
"to %u\n", dead_node, request_from);
memset(&lr, 0, sizeof(lr));
lr.node_idx = dlm->node_num;
lr.dead_node = dead_node;
// send message
ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
&lr, sizeof(lr), request_from, &status);
/* negative status is handled by caller */
if (ret < 0)
mlog(ML_ERROR, "%s: Error %d send LOCK_REQUEST to node %u "
"to recover dead node %u\n", dlm->name, ret,
request_from, dead_node);
else
ret = status;
// return from here, then
// sleep until all received or error
return ret;
}
int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
char *buf = NULL;
struct dlm_work_item *item = NULL;
if (!dlm_grab(dlm))
return -EINVAL;
if (lr->dead_node != dlm->reco.dead_node) {
mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
"dead_node is %u\n", dlm->name, lr->node_idx,
lr->dead_node, dlm->reco.dead_node);
dlm_print_reco_node_status(dlm);
/* this is a hack */
dlm_put(dlm);
return -ENOMEM;
}
BUG_ON(lr->dead_node != dlm->reco.dead_node);
item = kzalloc(sizeof(*item), GFP_NOFS);
if (!item) {
dlm_put(dlm);
return -ENOMEM;
}
/* this will get freed by dlm_request_all_locks_worker */
buf = (char *) __get_free_page(GFP_NOFS);
if (!buf) {
kfree(item);
dlm_put(dlm);
return -ENOMEM;
}
/* queue up work for dlm_request_all_locks_worker */
dlm_grab(dlm); /* get an extra ref for the work item */
dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
item->u.ral.reco_master = lr->node_idx;
item->u.ral.dead_node = lr->dead_node;
spin_lock(&dlm->work_lock);
list_add_tail(&item->list, &dlm->work_list);
spin_unlock(&dlm->work_lock);
queue_work(dlm->dlm_worker, &dlm->dispatched_work);
dlm_put(dlm);
return 0;
}
static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
{
struct dlm_migratable_lockres *mres;
struct dlm_lock_resource *res;
struct dlm_ctxt *dlm;
LIST_HEAD(resources);
int ret;
u8 dead_node, reco_master;
int skip_all_done = 0;
dlm = item->dlm;
dead_node = item->u.ral.dead_node;
reco_master = item->u.ral.reco_master;
mres = (struct dlm_migratable_lockres *)data;
mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
dlm->name, dead_node, reco_master);
if (dead_node != dlm->reco.dead_node ||
reco_master != dlm->reco.new_master) {
/* worker could have been created before the recovery master
* died. if so, do not continue, but do not error. */
if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
mlog(ML_NOTICE, "%s: will not send recovery state, "
"recovery master %u died, thread=(dead=%u,mas=%u)"
" current=(dead=%u,mas=%u)\n", dlm->name,
reco_master, dead_node, reco_master,
dlm->reco.dead_node, dlm->reco.new_master);
} else {
mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
"master=%u), request(dead=%u, master=%u)\n",
dlm->name, dlm->reco.dead_node,
dlm->reco.new_master, dead_node, reco_master);
}
goto leave;
}
/* lock resources should have already been moved to the
* dlm->reco.resources list. now move items from that list
* to a temp list if the dead owner matches. note that the
* whole cluster recovers only one node at a time, so we
* can safely move UNKNOWN lock resources for each recovery
* session. */
dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
/* now we can begin blasting lockreses without the dlm lock */
/* any errors returned will be due to the new_master dying,
* the dlm_reco_thread should detect this */
list_for_each_entry(res, &resources, recovering) {
ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
DLM_MRES_RECOVERY);
if (ret < 0) {
mlog(ML_ERROR, "%s: node %u went down while sending "
"recovery state for dead node %u, ret=%d\n", dlm->name,
reco_master, dead_node, ret);
skip_all_done = 1;
break;
}
}
/* move the resources back to the list */
spin_lock(&dlm->spinlock);
list_splice_init(&resources, &dlm->reco.resources);
spin_unlock(&dlm->spinlock);
if (!skip_all_done) {
ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
if (ret < 0) {
mlog(ML_ERROR, "%s: node %u went down while sending "
"recovery all-done for dead node %u, ret=%d\n",
dlm->name, reco_master, dead_node, ret);
}
}
leave:
free_page((unsigned long)data);
}
static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
{
int ret, tmpret;
struct dlm_reco_data_done done_msg;
memset(&done_msg, 0, sizeof(done_msg));
done_msg.node_idx = dlm->node_num;
done_msg.dead_node = dead_node;
mlog(0, "sending DATA DONE message to %u, "
"my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
done_msg.dead_node);
ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
sizeof(done_msg), send_to, &tmpret);
if (ret < 0) {
mlog(ML_ERROR, "%s: Error %d send RECO_DATA_DONE to node %u "
"to recover dead node %u\n", dlm->name, ret, send_to,
dead_node);
if (!dlm_is_host_down(ret)) {
BUG();
}
} else
ret = tmpret;
return ret;
}
int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
struct dlm_reco_node_data *ndata = NULL;
int ret = -EINVAL;
if (!dlm_grab(dlm))
return -EINVAL;
mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
"node_idx=%u, this node=%u\n", done->dead_node,
dlm->reco.dead_node, done->node_idx, dlm->node_num);
mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
"Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
"node_idx=%u, this node=%u\n", done->dead_node,
dlm->reco.dead_node, done->node_idx, dlm->node_num);
spin_lock(&dlm_reco_state_lock);
list_for_each_entry(ndata, &dlm->reco.node_data, list) {
if (ndata->node_num != done->node_idx)
continue;
switch (ndata->state) {
/* should have moved beyond INIT but not to FINALIZE yet */
case DLM_RECO_NODE_DATA_INIT:
case DLM_RECO_NODE_DATA_DEAD:
case DLM_RECO_NODE_DATA_FINALIZE_SENT:
mlog(ML_ERROR, "bad ndata state for node %u:"
" state=%d\n", ndata->node_num,
ndata->state);
BUG();
break;
/* these states are possible at this point, anywhere along
* the line of recovery */
case DLM_RECO_NODE_DATA_DONE:
case DLM_RECO_NODE_DATA_RECEIVING:
case DLM_RECO_NODE_DATA_REQUESTED:
case DLM_RECO_NODE_DATA_REQUESTING:
mlog(0, "node %u is DONE sending "
"recovery data!\n",
ndata->node_num);
ndata->state = DLM_RECO_NODE_DATA_DONE;
ret = 0;
break;
}
}
spin_unlock(&dlm_reco_state_lock);
/* wake the recovery thread, some node is done */
if (!ret)
dlm_kick_recovery_thread(dlm);
if (ret < 0)
mlog(ML_ERROR, "failed to find recovery node data for node "
"%u\n", done->node_idx);
dlm_put(dlm);
mlog(0, "leaving reco data done handler, ret=%d\n", ret);
return ret;
}
static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
struct list_head *list,
u8 dead_node)
{
struct dlm_lock_resource *res, *next;
struct dlm_lock *lock;
spin_lock(&dlm->spinlock);
list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
/* always prune any $RECOVERY entries for dead nodes,
* otherwise hangs can occur during later recovery */
if (dlm_is_recovery_lock(res->lockname.name,
res->lockname.len)) {
spin_lock(&res->spinlock);
list_for_each_entry(lock, &res->granted, list) {
if (lock->ml.node == dead_node) {
mlog(0, "AHA! there was "
"a $RECOVERY lock for dead "
"node %u (%s)!\n",
dead_node, dlm->name);
list_del_init(&lock->list);
dlm_lock_put(lock);
break;
}
}
spin_unlock(&res->spinlock);
continue;
}
if (res->owner == dead_node) {
mlog(0, "found lockres owned by dead node while "
"doing recovery for node %u. sending it.\n",
dead_node);
list_move_tail(&res->recovering, list);
} else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
mlog(0, "found UNKNOWN owner while doing recovery "
"for node %u. sending it.\n", dead_node);
list_move_tail(&res->recovering, list);
}
}
spin_unlock(&dlm->spinlock);
}
static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
{
int total_locks = 0;
struct list_head *iter, *queue = &res->granted;
int i;
for (i=0; i<3; i++) {
list_for_each(iter, queue)
total_locks++;
queue++;
}
return total_locks;
}
static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
struct dlm_migratable_lockres *mres,
u8 send_to,
struct dlm_lock_resource *res,
int total_locks)
{
u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
int mres_total_locks = be32_to_cpu(mres->total_locks);
int sz, ret = 0, status = 0;
u8 orig_flags = mres->flags,
orig_master = mres->master;
BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
if (!mres->num_locks)
return 0;
sz = sizeof(struct dlm_migratable_lockres) +
(mres->num_locks * sizeof(struct dlm_migratable_lock));
/* add an all-done flag if we reached the last lock */
orig_flags = mres->flags;
BUG_ON(total_locks > mres_total_locks);
if (total_locks == mres_total_locks)
mres->flags |= DLM_MRES_ALL_DONE;
mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
dlm->name, res->lockname.len, res->lockname.name,
orig_flags & DLM_MRES_MIGRATION ? "migration" : "recovery",
send_to);
/* send it */
ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
sz, send_to, &status);
if (ret < 0) {
/* XXX: negative status is not handled.
* this will end up killing this node. */
mlog(ML_ERROR, "%s: res %.*s, Error %d send MIG_LOCKRES to "
"node %u (%s)\n", dlm->name, mres->lockname_len,
mres->lockname, ret, send_to,
(orig_flags & DLM_MRES_MIGRATION ?
"migration" : "recovery"));
} else {
/* might get an -ENOMEM back here */
ret = status;
if (ret < 0) {
mlog_errno(ret);
if (ret == -EFAULT) {
mlog(ML_ERROR, "node %u told me to kill "
"myself!\n", send_to);
BUG();
}
}
}
/* zero and reinit the message buffer */
dlm_init_migratable_lockres(mres, res->lockname.name,
res->lockname.len, mres_total_locks,
mig_cookie, orig_flags, orig_master);
return ret;
}
static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
const char *lockname, int namelen,
int total_locks, u64 cookie,
u8 flags, u8 master)
{
/* mres here is one full page */
clear_page(mres);
mres->lockname_len = namelen;
memcpy(mres->lockname, lockname, namelen);
mres->num_locks = 0;
mres->total_locks = cpu_to_be32(total_locks);
mres->mig_cookie = cpu_to_be64(cookie);
mres->flags = flags;
mres->master = master;
}
static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
struct dlm_migratable_lockres *mres,
int queue)
{
if (!lock->lksb)
return;
/* Ignore lvb in all locks in the blocked list */
if (queue == DLM_BLOCKED_LIST)
return;
/* Only consider lvbs in locks with granted EX or PR lock levels */
if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
return;
if (dlm_lvb_is_empty(mres->lvb)) {
memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
return;
}
/* Ensure the lvb copied for migration matches in other valid locks */
if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
return;
mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
"node=%u\n",
dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
lock->lockres->lockname.len, lock->lockres->lockname.name,
lock->ml.node);
dlm_print_one_lock_resource(lock->lockres);
BUG();
}
/* returns 1 if this lock fills the network structure,
* 0 otherwise */
static int dlm_add_lock_to_array(struct dlm_lock *lock,
struct dlm_migratable_lockres *mres, int queue)
{
struct dlm_migratable_lock *ml;
int lock_num = mres->num_locks;
ml = &(mres->ml[lock_num]);
ml->cookie = lock->ml.cookie;
ml->type = lock->ml.type;
ml->convert_type = lock->ml.convert_type;
ml->highest_blocked = lock->ml.highest_blocked;
ml->list = queue;
if (lock->lksb) {
ml->flags = lock->lksb->flags;
dlm_prepare_lvb_for_migration(lock, mres, queue);
}
ml->node = lock->ml.node;
mres->num_locks++;
/* we reached the max, send this network message */
if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
return 1;
return 0;
}
static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
struct dlm_migratable_lockres *mres)
{
struct dlm_lock dummy;
memset(&dummy, 0, sizeof(dummy));
dummy.ml.cookie = 0;
dummy.ml.type = LKM_IVMODE;
dummy.ml.convert_type = LKM_IVMODE;
dummy.ml.highest_blocked = LKM_IVMODE;
dummy.lksb = NULL;
dummy.ml.node = dlm->node_num;
dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
}
static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
struct dlm_migratable_lock *ml,
u8 *nodenum)
{
if (unlikely(ml->cookie == 0 &&
ml->type == LKM_IVMODE &&
ml->convert_type == LKM_IVMODE &&
ml->highest_blocked == LKM_IVMODE &&
ml->list == DLM_BLOCKED_LIST)) {
*nodenum = ml->node;
return 1;
}
return 0;
}
int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
struct dlm_migratable_lockres *mres,
u8 send_to, u8 flags)
{
struct list_head *queue;
int total_locks, i;
u64 mig_cookie = 0;
struct dlm_lock *lock;
int ret = 0;
BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
mlog(0, "sending to %u\n", send_to);
total_locks = dlm_num_locks_in_lockres(res);
if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
/* rare, but possible */
mlog(0, "argh. lockres has %d locks. this will "
"require more than one network packet to "
"migrate\n", total_locks);
mig_cookie = dlm_get_next_mig_cookie();
}
dlm_init_migratable_lockres(mres, res->lockname.name,
res->lockname.len, total_locks,
mig_cookie, flags, res->owner);
total_locks = 0;
for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
queue = dlm_list_idx_to_ptr(res, i);
list_for_each_entry(lock, queue, list) {
/* add another lock. */
total_locks++;
if (!dlm_add_lock_to_array(lock, mres, i))
continue;
/* this filled the lock message,
* we must send it immediately. */
ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
res, total_locks);
if (ret < 0)
goto error;
}
}
if (total_locks == 0) {
/* send a dummy lock to indicate a mastery reference only */
mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
dlm->name, res->lockname.len, res->lockname.name,
send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
"migration");
dlm_add_dummy_lock(dlm, mres);
}
/* flush any remaining locks */
ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
if (ret < 0)
goto error;
return ret;
error:
mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
dlm->name, ret);
if (!dlm_is_host_down(ret))
BUG();
mlog(0, "%s: node %u went down while sending %s "
"lockres %.*s\n", dlm->name, send_to,
flags & DLM_MRES_RECOVERY ? "recovery" : "migration",
res->lockname.len, res->lockname.name);
return ret;
}
/*
* this message will contain no more than one page worth of
* recovery data, and it will work on only one lockres.
* there may be many locks in this page, and we may need to wait
* for additional packets to complete all the locks (rare, but
* possible).
*/
/*
* NOTE: the allocation error cases here are scary
* we really cannot afford to fail an alloc in recovery
* do we spin? returning an error only delays the problem really
*/
int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_migratable_lockres *mres =
(struct dlm_migratable_lockres *)msg->buf;
int ret = 0;
u8 real_master;
u8 extra_refs = 0;
char *buf = NULL;
struct dlm_work_item *item = NULL;
struct dlm_lock_resource *res = NULL;
if (!dlm_grab(dlm))
return -EINVAL;
BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
real_master = mres->master;
if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
/* cannot migrate a lockres with no master */
BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
}
mlog(0, "%s message received from node %u\n",
(mres->flags & DLM_MRES_RECOVERY) ?
"recovery" : "migration", mres->master);
if (mres->flags & DLM_MRES_ALL_DONE)
mlog(0, "all done flag. all lockres data received!\n");
ret = -ENOMEM;
buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
item = kzalloc(sizeof(*item), GFP_NOFS);
if (!buf || !item)
goto leave;
/* lookup the lock to see if we have a secondary queue for this
* already... just add the locks in and this will have its owner
* and RECOVERY flag changed when it completes. */
res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
if (res) {
/* this will get a ref on res */
/* mark it as recovering/migrating and hash it */
spin_lock(&res->spinlock);
if (mres->flags & DLM_MRES_RECOVERY) {
res->state |= DLM_LOCK_RES_RECOVERING;
} else {
if (res->state & DLM_LOCK_RES_MIGRATING) {
/* this is at least the second
* lockres message */
mlog(0, "lock %.*s is already migrating\n",
mres->lockname_len,
mres->lockname);
} else if (res->state & DLM_LOCK_RES_RECOVERING) {
/* caller should BUG */
mlog(ML_ERROR, "node is attempting to migrate "
"lock %.*s, but marked as recovering!\n",
mres->lockname_len, mres->lockname);
ret = -EFAULT;
spin_unlock(&res->spinlock);
dlm_lockres_put(res);
goto leave;
}
res->state |= DLM_LOCK_RES_MIGRATING;
}
spin_unlock(&res->spinlock);
} else {
/* need to allocate, just like if it was
* mastered here normally */
res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
if (!res)
goto leave;
/* to match the ref that we would have gotten if
* dlm_lookup_lockres had succeeded */
dlm_lockres_get(res);
/* mark it as recovering/migrating and hash it */
if (mres->flags & DLM_MRES_RECOVERY)
res->state |= DLM_LOCK_RES_RECOVERING;
else
res->state |= DLM_LOCK_RES_MIGRATING;
spin_lock(&dlm->spinlock);
__dlm_insert_lockres(dlm, res);
spin_unlock(&dlm->spinlock);
/* Add an extra ref for this lock-less lockres lest the
* dlm_thread purges it before we get the chance to add
* locks to it */
dlm_lockres_get(res);
/* There are three refs that need to be put.
* 1. Taken above.
* 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
* 3. dlm_lookup_lockres()
* The first one is handled at the end of this function. The
* other two are handled in the worker thread after locks have
* been attached. Yes, we don't wait for purge time to match
* kref_init. The lockres will still have atleast one ref
* added because it is in the hash __dlm_insert_lockres() */
extra_refs++;
/* now that the new lockres is inserted,
* make it usable by other processes */
spin_lock(&res->spinlock);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
spin_unlock(&res->spinlock);
wake_up(&res->wq);
}
/* at this point we have allocated everything we need,
* and we have a hashed lockres with an extra ref and
* the proper res->state flags. */
ret = 0;
spin_lock(&res->spinlock);
/* drop this either when master requery finds a different master
* or when a lock is added by the recovery worker */
dlm_lockres_grab_inflight_ref(dlm, res);
if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
/* migration cannot have an unknown master */
BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
mlog(0, "recovery has passed me a lockres with an "
"unknown owner.. will need to requery: "
"%.*s\n", mres->lockname_len, mres->lockname);
} else {
/* take a reference now to pin the lockres, drop it
* when locks are added in the worker */
dlm_change_lockres_owner(dlm, res, dlm->node_num);
}
spin_unlock(&res->spinlock);
/* queue up work for dlm_mig_lockres_worker */
dlm_grab(dlm); /* get an extra ref for the work item */
memcpy(buf, msg->buf, be16_to_cpu(msg->data_len)); /* copy the whole message */
dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
item->u.ml.lockres = res; /* already have a ref */
item->u.ml.real_master = real_master;
item->u.ml.extra_ref = extra_refs;
spin_lock(&dlm->work_lock);
list_add_tail(&item->list, &dlm->work_list);
spin_unlock(&dlm->work_lock);
queue_work(dlm->dlm_worker, &dlm->dispatched_work);
leave:
/* One extra ref taken needs to be put here */
if (extra_refs)
dlm_lockres_put(res);
dlm_put(dlm);
if (ret < 0) {
kfree(buf);
kfree(item);
mlog_errno(ret);
}
return ret;
}
static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
{
struct dlm_ctxt *dlm;
struct dlm_migratable_lockres *mres;
int ret = 0;
struct dlm_lock_resource *res;
u8 real_master;
u8 extra_ref;
dlm = item->dlm;
mres = (struct dlm_migratable_lockres *)data;
res = item->u.ml.lockres;
real_master = item->u.ml.real_master;
extra_ref = item->u.ml.extra_ref;
if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
/* this case is super-rare. only occurs if
* node death happens during migration. */
again:
ret = dlm_lockres_master_requery(dlm, res, &real_master);
if (ret < 0) {
mlog(0, "dlm_lockres_master_requery ret=%d\n",
ret);
goto again;
}
if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
mlog(0, "lockres %.*s not claimed. "
"this node will take it.\n",
res->lockname.len, res->lockname.name);
} else {
spin_lock(&res->spinlock);
dlm_lockres_drop_inflight_ref(dlm, res);
spin_unlock(&res->spinlock);
mlog(0, "master needs to respond to sender "
"that node %u still owns %.*s\n",
real_master, res->lockname.len,
res->lockname.name);
/* cannot touch this lockres */
goto leave;
}
}
ret = dlm_process_recovery_data(dlm, res, mres);
if (ret < 0)
mlog(0, "dlm_process_recovery_data returned %d\n", ret);
else
mlog(0, "dlm_process_recovery_data succeeded\n");
if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
(DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
ret = dlm_finish_migration(dlm, res, mres->master);
if (ret < 0)
mlog_errno(ret);
}
leave:
/* See comment in dlm_mig_lockres_handler() */
if (res) {
if (extra_ref)
dlm_lockres_put(res);
dlm_lockres_put(res);
}
kfree(data);
}
static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
u8 *real_master)
{
struct dlm_node_iter iter;
int nodenum;
int ret = 0;
*real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
/* we only reach here if one of the two nodes in a
* migration died while the migration was in progress.
* at this point we need to requery the master. we
* know that the new_master got as far as creating
* an mle on at least one node, but we do not know
* if any nodes had actually cleared the mle and set
* the master to the new_master. the old master
* is supposed to set the owner to UNKNOWN in the
* event of a new_master death, so the only possible
* responses that we can get from nodes here are
* that the master is new_master, or that the master
* is UNKNOWN.
* if all nodes come back with UNKNOWN then we know
* the lock needs remastering here.
* if any node comes back with a valid master, check
* to see if that master is the one that we are
* recovering. if so, then the new_master died and
* we need to remaster this lock. if not, then the
* new_master survived and that node will respond to
* other nodes about the owner.
* if there is an owner, this node needs to dump this
* lockres and alert the sender that this lockres
* was rejected. */
spin_lock(&dlm->spinlock);
dlm_node_iter_init(dlm->domain_map, &iter);
spin_unlock(&dlm->spinlock);
while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
/* do not send to self */
if (nodenum == dlm->node_num)
continue;
ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
if (ret < 0) {
mlog_errno(ret);
if (!dlm_is_host_down(ret))
BUG();
/* host is down, so answer for that node would be
* DLM_LOCK_RES_OWNER_UNKNOWN. continue. */
}
if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
mlog(0, "lock master is %u\n", *real_master);
break;
}
}
return ret;
}
int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
u8 nodenum, u8 *real_master)
{
int ret = -EINVAL;
struct dlm_master_requery req;
int status = DLM_LOCK_RES_OWNER_UNKNOWN;
memset(&req, 0, sizeof(req));
req.node_idx = dlm->node_num;
req.namelen = res->lockname.len;
memcpy(req.name, res->lockname.name, res->lockname.len);
ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
&req, sizeof(req), nodenum, &status);
/* XXX: negative status not handled properly here. */
if (ret < 0)
mlog(ML_ERROR, "Error %d when sending message %u (key "
"0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
dlm->key, nodenum);
else {
BUG_ON(status < 0);
BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
*real_master = (u8) (status & 0xff);
mlog(0, "node %u responded to master requery with %u\n",
nodenum, *real_master);
ret = 0;
}
return ret;
}
/* this function cannot error, so unless the sending
* or receiving of the message failed, the owner can
* be trusted */
int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
struct dlm_lock_resource *res = NULL;
unsigned int hash;
int master = DLM_LOCK_RES_OWNER_UNKNOWN;
u32 flags = DLM_ASSERT_MASTER_REQUERY;
if (!dlm_grab(dlm)) {
/* since the domain has gone away on this
* node, the proper response is UNKNOWN */
return master;
}
hash = dlm_lockid_hash(req->name, req->namelen);
spin_lock(&dlm->spinlock);
res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
if (res) {
spin_lock(&res->spinlock);
master = res->owner;
if (master == dlm->node_num) {
int ret = dlm_dispatch_assert_master(dlm, res,
0, 0, flags);
if (ret < 0) {
mlog_errno(-ENOMEM);
/* retry!? */
BUG();
}
} else /* put.. incase we are not the master */
dlm_lockres_put(res);
spin_unlock(&res->spinlock);
}
spin_unlock(&dlm->spinlock);
dlm_put(dlm);
return master;
}
static inline struct list_head *
dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
{
struct list_head *ret;
BUG_ON(list_num < 0);
BUG_ON(list_num > 2);
ret = &(res->granted);
ret += list_num;
return ret;
}
/* TODO: do ast flush business
* TODO: do MIGRATING and RECOVERING spinning
*/
/*
* NOTE about in-flight requests during migration:
*
* Before attempting the migrate, the master has marked the lockres as
* MIGRATING and then flushed all of its pending ASTS. So any in-flight
* requests either got queued before the MIGRATING flag got set, in which
* case the lock data will reflect the change and a return message is on
* the way, or the request failed to get in before MIGRATING got set. In
* this case, the caller will be told to spin and wait for the MIGRATING
* flag to be dropped, then recheck the master.
* This holds true for the convert, cancel and unlock cases, and since lvb
* updates are tied to these same messages, it applies to lvb updates as
* well. For the lock case, there is no way a lock can be on the master
* queue and not be on the secondary queue since the lock is always added
* locally first. This means that the new target node will never be sent
* a lock that he doesn't already have on the list.
* In total, this means that the local lock is correct and should not be
* updated to match the one sent by the master. Any messages sent back
* from the master before the MIGRATING flag will bring the lock properly
* up-to-date, and the change will be ordered properly for the waiter.
* We will *not* attempt to modify the lock underneath the waiter.
*/
static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res,
struct dlm_migratable_lockres *mres)
{
struct dlm_migratable_lock *ml;
struct list_head *queue;
struct list_head *tmpq = NULL;
struct dlm_lock *newlock = NULL;
struct dlm_lockstatus *lksb = NULL;
int ret = 0;
int i, j, bad;
struct dlm_lock *lock = NULL;
u8 from = O2NM_MAX_NODES;
unsigned int added = 0;
__be64 c;
mlog(0, "running %d locks for this lockres\n", mres->num_locks);
for (i=0; i<mres->num_locks; i++) {
ml = &(mres->ml[i]);
if (dlm_is_dummy_lock(dlm, ml, &from)) {
/* placeholder, just need to set the refmap bit */
BUG_ON(mres->num_locks != 1);
mlog(0, "%s:%.*s: dummy lock for %u\n",
dlm->name, mres->lockname_len, mres->lockname,
from);
spin_lock(&res->spinlock);
dlm_lockres_set_refmap_bit(dlm, res, from);
spin_unlock(&res->spinlock);
added++;
break;
}
BUG_ON(ml->highest_blocked != LKM_IVMODE);
newlock = NULL;
lksb = NULL;
queue = dlm_list_num_to_pointer(res, ml->list);
tmpq = NULL;
/* if the lock is for the local node it needs to
* be moved to the proper location within the queue.
* do not allocate a new lock structure. */
if (ml->node == dlm->node_num) {
/* MIGRATION ONLY! */
BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
spin_lock(&res->spinlock);
for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
tmpq = dlm_list_idx_to_ptr(res, j);
list_for_each_entry(lock, tmpq, list) {
if (lock->ml.cookie != ml->cookie)
lock = NULL;
else
break;
}
if (lock)
break;
}
/* lock is always created locally first, and
* destroyed locally last. it must be on the list */
if (!lock) {
c = ml->cookie;
mlog(ML_ERROR, "Could not find local lock "
"with cookie %u:%llu, node %u, "
"list %u, flags 0x%x, type %d, "
"conv %d, highest blocked %d\n",
dlm_get_lock_cookie_node(be64_to_cpu(c)),
dlm_get_lock_cookie_seq(be64_to_cpu(c)),
ml->node, ml->list, ml->flags, ml->type,
ml->convert_type, ml->highest_blocked);
__dlm_print_one_lock_resource(res);
BUG();
}
if (lock->ml.node != ml->node) {
c = lock->ml.cookie;
mlog(ML_ERROR, "Mismatched node# in lock "
"cookie %u:%llu, name %.*s, node %u\n",
dlm_get_lock_cookie_node(be64_to_cpu(c)),
dlm_get_lock_cookie_seq(be64_to_cpu(c)),
res->lockname.len, res->lockname.name,
lock->ml.node);
c = ml->cookie;
mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
"node %u, list %u, flags 0x%x, type %d, "
"conv %d, highest blocked %d\n",
dlm_get_lock_cookie_node(be64_to_cpu(c)),
dlm_get_lock_cookie_seq(be64_to_cpu(c)),
ml->node, ml->list, ml->flags, ml->type,
ml->convert_type, ml->highest_blocked);
__dlm_print_one_lock_resource(res);
BUG();
}
if (tmpq != queue) {
c = ml->cookie;
mlog(0, "Lock cookie %u:%llu was on list %u "
"instead of list %u for %.*s\n",
dlm_get_lock_cookie_node(be64_to_cpu(c)),
dlm_get_lock_cookie_seq(be64_to_cpu(c)),
j, ml->list, res->lockname.len,
res->lockname.name);
__dlm_print_one_lock_resource(res);
spin_unlock(&res->spinlock);
continue;
}
/* see NOTE above about why we do not update
* to match the master here */
/* move the lock to its proper place */
/* do not alter lock refcount. switching lists. */
list_move_tail(&lock->list, queue);
spin_unlock(&res->spinlock);
added++;
mlog(0, "just reordered a local lock!\n");
continue;
}
/* lock is for another node. */
newlock = dlm_new_lock(ml->type, ml->node,
be64_to_cpu(ml->cookie), NULL);
if (!newlock) {
ret = -ENOMEM;
goto leave;
}
lksb = newlock->lksb;
dlm_lock_attach_lockres(newlock, res);
if (ml->convert_type != LKM_IVMODE) {
BUG_ON(queue != &res->converting);
newlock->ml.convert_type = ml->convert_type;
}
lksb->flags |= (ml->flags &
(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
if (ml->type == LKM_NLMODE)
goto skip_lvb;
/*
* If the lock is in the blocked list it can't have a valid lvb,
* so skip it
*/
if (ml->list == DLM_BLOCKED_LIST)
goto skip_lvb;
if (!dlm_lvb_is_empty(mres->lvb)) {
if (lksb->flags & DLM_LKSB_PUT_LVB) {
/* other node was trying to update
* lvb when node died. recreate the
* lksb with the updated lvb. */
memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
/* the lock resource lvb update must happen
* NOW, before the spinlock is dropped.
* we no longer wait for the AST to update
* the lvb. */
memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
} else {
/* otherwise, the node is sending its
* most recent valid lvb info */
BUG_ON(ml->type != LKM_EXMODE &&
ml->type != LKM_PRMODE);
if (!dlm_lvb_is_empty(res->lvb) &&
(ml->type == LKM_EXMODE ||
memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
int i;
mlog(ML_ERROR, "%s:%.*s: received bad "
"lvb! type=%d\n", dlm->name,
res->lockname.len,
res->lockname.name, ml->type);
printk("lockres lvb=[");
for (i=0; i<DLM_LVB_LEN; i++)
printk("%02x", res->lvb[i]);
printk("]\nmigrated lvb=[");
for (i=0; i<DLM_LVB_LEN; i++)
printk("%02x", mres->lvb[i]);
printk("]\n");
dlm_print_one_lock_resource(res);
BUG();
}
memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
}
}
skip_lvb:
/* NOTE:
* wrt lock queue ordering and recovery:
* 1. order of locks on granted queue is
* meaningless.
* 2. order of locks on converting queue is
* LOST with the node death. sorry charlie.
* 3. order of locks on the blocked queue is
* also LOST.
* order of locks does not affect integrity, it
* just means that a lock request may get pushed
* back in line as a result of the node death.
* also note that for a given node the lock order
* for its secondary queue locks is preserved
* relative to each other, but clearly *not*
* preserved relative to locks from other nodes.
*/
bad = 0;
spin_lock(&res->spinlock);
list_for_each_entry(lock, queue, list) {
if (lock->ml.cookie == ml->cookie) {
c = lock->ml.cookie;
mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
"exists on this lockres!\n", dlm->name,
res->lockname.len, res->lockname.name,
dlm_get_lock_cookie_node(be64_to_cpu(c)),
dlm_get_lock_cookie_seq(be64_to_cpu(c)));
mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
"node=%u, cookie=%u:%llu, queue=%d\n",
ml->type, ml->convert_type, ml->node,
dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
ml->list);
__dlm_print_one_lock_resource(res);
bad = 1;
break;
}
}
if (!bad) {
dlm_lock_get(newlock);
list_add_tail(&newlock->list, queue);
mlog(0, "%s:%.*s: added lock for node %u, "
"setting refmap bit\n", dlm->name,
res->lockname.len, res->lockname.name, ml->node);
dlm_lockres_set_refmap_bit(dlm, res, ml->node);
added++;
}
spin_unlock(&res->spinlock);
}
mlog(0, "done running all the locks\n");
leave:
/* balance the ref taken when the work was queued */
spin_lock(&res->spinlock);
dlm_lockres_drop_inflight_ref(dlm, res);
spin_unlock(&res->spinlock);
if (ret < 0) {
mlog_errno(ret);
if (newlock)
dlm_lock_put(newlock);
}
return ret;
}
void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res)
{
int i;
struct list_head *queue;
struct dlm_lock *lock, *next;
assert_spin_locked(&dlm->spinlock);
assert_spin_locked(&res->spinlock);
res->state |= DLM_LOCK_RES_RECOVERING;
if (!list_empty(&res->recovering)) {
mlog(0,
"Recovering res %s:%.*s, is already on recovery list!\n",
dlm->name, res->lockname.len, res->lockname.name);
list_del_init(&res->recovering);
dlm_lockres_put(res);
}
/* We need to hold a reference while on the recovery list */
dlm_lockres_get(res);
list_add_tail(&res->recovering, &dlm->reco.resources);
/* find any pending locks and put them back on proper list */
for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
queue = dlm_list_idx_to_ptr(res, i);
list_for_each_entry_safe(lock, next, queue, list) {
dlm_lock_get(lock);
if (lock->convert_pending) {
/* move converting lock back to granted */
BUG_ON(i != DLM_CONVERTING_LIST);
mlog(0, "node died with convert pending "
"on %.*s. move back to granted list.\n",
res->lockname.len, res->lockname.name);
dlm_revert_pending_convert(res, lock);
lock->convert_pending = 0;
} else if (lock->lock_pending) {
/* remove pending lock requests completely */
BUG_ON(i != DLM_BLOCKED_LIST);
mlog(0, "node died with lock pending "
"on %.*s. remove from blocked list and skip.\n",
res->lockname.len, res->lockname.name);
/* lock will be floating until ref in
* dlmlock_remote is freed after the network
* call returns. ok for it to not be on any
* list since no ast can be called
* (the master is dead). */
dlm_revert_pending_lock(res, lock);
lock->lock_pending = 0;
} else if (lock->unlock_pending) {
/* if an unlock was in progress, treat as
* if this had completed successfully
* before sending this lock state to the
* new master. note that the dlm_unlock
* call is still responsible for calling
* the unlockast. that will happen after
* the network call times out. for now,
* just move lists to prepare the new
* recovery master. */
BUG_ON(i != DLM_GRANTED_LIST);
mlog(0, "node died with unlock pending "
"on %.*s. remove from blocked list and skip.\n",
res->lockname.len, res->lockname.name);
dlm_commit_pending_unlock(res, lock);
lock->unlock_pending = 0;
} else if (lock->cancel_pending) {
/* if a cancel was in progress, treat as
* if this had completed successfully
* before sending this lock state to the
* new master */
BUG_ON(i != DLM_CONVERTING_LIST);
mlog(0, "node died with cancel pending "
"on %.*s. move back to granted list.\n",
res->lockname.len, res->lockname.name);
dlm_commit_pending_cancel(res, lock);
lock->cancel_pending = 0;
}
dlm_lock_put(lock);
}
}
}
/* removes all recovered locks from the recovery list.
* sets the res->owner to the new master.
* unsets the RECOVERY flag and wakes waiters. */
static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
u8 dead_node, u8 new_master)
{
int i;
struct hlist_head *bucket;
struct dlm_lock_resource *res, *next;
assert_spin_locked(&dlm->spinlock);
list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
if (res->owner == dead_node) {
mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
dlm->name, res->lockname.len, res->lockname.name,
res->owner, new_master);
list_del_init(&res->recovering);
spin_lock(&res->spinlock);
/* new_master has our reference from
* the lock state sent during recovery */
dlm_change_lockres_owner(dlm, res, new_master);
res->state &= ~DLM_LOCK_RES_RECOVERING;
if (__dlm_lockres_has_locks(res))
__dlm_dirty_lockres(dlm, res);
spin_unlock(&res->spinlock);
wake_up(&res->wq);
dlm_lockres_put(res);
}
}
/* this will become unnecessary eventually, but
* for now we need to run the whole hash, clear
* the RECOVERING state and set the owner
* if necessary */
for (i = 0; i < DLM_HASH_BUCKETS; i++) {
bucket = dlm_lockres_hash(dlm, i);
hlist_for_each_entry(res, bucket, hash_node) {
if (!(res->state & DLM_LOCK_RES_RECOVERING))
continue;
if (res->owner != dead_node &&
res->owner != dlm->node_num)
continue;
if (!list_empty(&res->recovering)) {
list_del_init(&res->recovering);
dlm_lockres_put(res);
}
/* new_master has our reference from
* the lock state sent during recovery */
mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
dlm->name, res->lockname.len, res->lockname.name,
res->owner, new_master);
spin_lock(&res->spinlock);
dlm_change_lockres_owner(dlm, res, new_master);
res->state &= ~DLM_LOCK_RES_RECOVERING;
if (__dlm_lockres_has_locks(res))
__dlm_dirty_lockres(dlm, res);
spin_unlock(&res->spinlock);
wake_up(&res->wq);
}
}
}
static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
{
if (local) {
if (lock->ml.type != LKM_EXMODE &&
lock->ml.type != LKM_PRMODE)
return 1;
} else if (lock->ml.type == LKM_EXMODE)
return 1;
return 0;
}
static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res, u8 dead_node)
{
struct list_head *queue;
struct dlm_lock *lock;
int blank_lvb = 0, local = 0;
int i;
u8 search_node;
assert_spin_locked(&dlm->spinlock);
assert_spin_locked(&res->spinlock);
if (res->owner == dlm->node_num)
/* if this node owned the lockres, and if the dead node
* had an EX when he died, blank out the lvb */
search_node = dead_node;
else {
/* if this is a secondary lockres, and we had no EX or PR
* locks granted, we can no longer trust the lvb */
search_node = dlm->node_num;
local = 1; /* check local state for valid lvb */
}
for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
queue = dlm_list_idx_to_ptr(res, i);
list_for_each_entry(lock, queue, list) {
if (lock->ml.node == search_node) {
if (dlm_lvb_needs_invalidation(lock, local)) {
/* zero the lksb lvb and lockres lvb */
blank_lvb = 1;
memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
}
}
}
}
if (blank_lvb) {
mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
res->lockname.len, res->lockname.name, dead_node);
memset(res->lvb, 0, DLM_LVB_LEN);
}
}
static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res, u8 dead_node)
{
struct dlm_lock *lock, *next;
unsigned int freed = 0;
/* this node is the lockres master:
* 1) remove any stale locks for the dead node
* 2) if the dead node had an EX when he died, blank out the lvb
*/
assert_spin_locked(&dlm->spinlock);
assert_spin_locked(&res->spinlock);
/* We do two dlm_lock_put(). One for removing from list and the other is
* to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
/* TODO: check pending_asts, pending_basts here */
list_for_each_entry_safe(lock, next, &res->granted, list) {
if (lock->ml.node == dead_node) {
list_del_init(&lock->list);
dlm_lock_put(lock);
/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
dlm_lock_put(lock);
freed++;
}
}
list_for_each_entry_safe(lock, next, &res->converting, list) {
if (lock->ml.node == dead_node) {
list_del_init(&lock->list);
dlm_lock_put(lock);
/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
dlm_lock_put(lock);
freed++;
}
}
list_for_each_entry_safe(lock, next, &res->blocked, list) {
if (lock->ml.node == dead_node) {
list_del_init(&lock->list);
dlm_lock_put(lock);
/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
dlm_lock_put(lock);
freed++;
}
}
if (freed) {
mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
"dropping ref from lockres\n", dlm->name,
res->lockname.len, res->lockname.name, freed, dead_node);
if(!test_bit(dead_node, res->refmap)) {
mlog(ML_ERROR, "%s:%.*s: freed %u locks for dead node %u, "
"but ref was not set\n", dlm->name,
res->lockname.len, res->lockname.name, freed, dead_node);
__dlm_print_one_lock_resource(res);
}
dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
} else if (test_bit(dead_node, res->refmap)) {
mlog(0, "%s:%.*s: dead node %u had a ref, but had "
"no locks and had not purged before dying\n", dlm->name,
res->lockname.len, res->lockname.name, dead_node);
dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
}
/* do not kick thread yet */
__dlm_dirty_lockres(dlm, res);
}
/* if this node is the recovery master, and there are no
* locks for a given lockres owned by this node that are in
* either PR or EX mode, zero out the lvb before requesting.
*
*/
static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
{
struct dlm_lock_resource *res;
int i;
struct hlist_head *bucket;
struct dlm_lock *lock;
/* purge any stale mles */
dlm_clean_master_list(dlm, dead_node);
/*
* now clean up all lock resources. there are two rules:
*
* 1) if the dead node was the master, move the lockres
* to the recovering list. set the RECOVERING flag.
* this lockres needs to be cleaned up before it can
* be used further.
*
* 2) if this node was the master, remove all locks from
* each of the lockres queues that were owned by the
* dead node. once recovery finishes, the dlm thread
* can be kicked again to see if any ASTs or BASTs
* need to be fired as a result.
*/
for (i = 0; i < DLM_HASH_BUCKETS; i++) {
bucket = dlm_lockres_hash(dlm, i);
hlist_for_each_entry(res, bucket, hash_node) {
/* always prune any $RECOVERY entries for dead nodes,
* otherwise hangs can occur during later recovery */
if (dlm_is_recovery_lock(res->lockname.name,
res->lockname.len)) {
spin_lock(&res->spinlock);
list_for_each_entry(lock, &res->granted, list) {
if (lock->ml.node == dead_node) {
mlog(0, "AHA! there was "
"a $RECOVERY lock for dead "
"node %u (%s)!\n",
dead_node, dlm->name);
list_del_init(&lock->list);
dlm_lock_put(lock);
break;
}
}
spin_unlock(&res->spinlock);
continue;
}
spin_lock(&res->spinlock);
/* zero the lvb if necessary */
dlm_revalidate_lvb(dlm, res, dead_node);
if (res->owner == dead_node) {
if (res->state & DLM_LOCK_RES_DROPPING_REF) {
mlog(ML_NOTICE, "%s: res %.*s, Skip "
"recovery as it is being freed\n",
dlm->name, res->lockname.len,
res->lockname.name);
} else
dlm_move_lockres_to_recovery_list(dlm,
res);
} else if (res->owner == dlm->node_num) {
dlm_free_dead_locks(dlm, res, dead_node);
__dlm_lockres_calc_usage(dlm, res);
} else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
if (test_bit(dead_node, res->refmap)) {
mlog(0, "%s:%.*s: dead node %u had a ref, but had "
"no locks and had not purged before dying\n",
dlm->name, res->lockname.len,
res->lockname.name, dead_node);
dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
}
}
spin_unlock(&res->spinlock);
}
}
}
static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
{
assert_spin_locked(&dlm->spinlock);
if (dlm->reco.new_master == idx) {
mlog(0, "%s: recovery master %d just died\n",
dlm->name, idx);
if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
/* finalize1 was reached, so it is safe to clear
* the new_master and dead_node. that recovery
* is complete. */
mlog(0, "%s: dead master %d had reached "
"finalize1 state, clearing\n", dlm->name, idx);
dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
__dlm_reset_recovery(dlm);
}
}
/* Clean up join state on node death. */
if (dlm->joining_node == idx) {
mlog(0, "Clearing join state for node %u\n", idx);
__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
}
/* check to see if the node is already considered dead */
if (!test_bit(idx, dlm->live_nodes_map)) {
mlog(0, "for domain %s, node %d is already dead. "
"another node likely did recovery already.\n",
dlm->name, idx);
return;
}
/* check to see if we do not care about this node */
if (!test_bit(idx, dlm->domain_map)) {
/* This also catches the case that we get a node down
* but haven't joined the domain yet. */
mlog(0, "node %u already removed from domain!\n", idx);
return;
}
clear_bit(idx, dlm->live_nodes_map);
/* make sure local cleanup occurs before the heartbeat events */
if (!test_bit(idx, dlm->recovery_map))
dlm_do_local_recovery_cleanup(dlm, idx);
/* notify anything attached to the heartbeat events */
dlm_hb_event_notify_attached(dlm, idx, 0);
mlog(0, "node %u being removed from domain map!\n", idx);
clear_bit(idx, dlm->domain_map);
clear_bit(idx, dlm->exit_domain_map);
/* wake up migration waiters if a node goes down.
* perhaps later we can genericize this for other waiters. */
wake_up(&dlm->migration_wq);
if (test_bit(idx, dlm->recovery_map))
mlog(0, "domain %s, node %u already added "
"to recovery map!\n", dlm->name, idx);
else
set_bit(idx, dlm->recovery_map);
}
void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
{
struct dlm_ctxt *dlm = data;
if (!dlm_grab(dlm))
return;
/*
* This will notify any dlm users that a node in our domain
* went away without notifying us first.
*/
if (test_bit(idx, dlm->domain_map))
dlm_fire_domain_eviction_callbacks(dlm, idx);
spin_lock(&dlm->spinlock);
__dlm_hb_node_down(dlm, idx);
spin_unlock(&dlm->spinlock);
dlm_put(dlm);
}
void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
{
struct dlm_ctxt *dlm = data;
if (!dlm_grab(dlm))
return;
spin_lock(&dlm->spinlock);
set_bit(idx, dlm->live_nodes_map);
/* do NOT notify mle attached to the heartbeat events.
* new nodes are not interesting in mastery until joined. */
spin_unlock(&dlm->spinlock);
dlm_put(dlm);
}
static void dlm_reco_ast(void *astdata)
{
struct dlm_ctxt *dlm = astdata;
mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
dlm->node_num, dlm->name);
}
static void dlm_reco_bast(void *astdata, int blocked_type)
{
struct dlm_ctxt *dlm = astdata;
mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
dlm->node_num, dlm->name);
}
static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
{
mlog(0, "unlockast for recovery lock fired!\n");
}
/*
* dlm_pick_recovery_master will continually attempt to use
* dlmlock() on the special "$RECOVERY" lockres with the
* LKM_NOQUEUE flag to get an EX. every thread that enters
* this function on each node racing to become the recovery
* master will not stop attempting this until either:
* a) this node gets the EX (and becomes the recovery master),
* or b) dlm->reco.new_master gets set to some nodenum
* != O2NM_INVALID_NODE_NUM (another node will do the reco).
* so each time a recovery master is needed, the entire cluster
* will sync at this point. if the new master dies, that will
* be detected in dlm_do_recovery */
static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
{
enum dlm_status ret;
struct dlm_lockstatus lksb;
int status = -EINVAL;
mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
again:
memset(&lksb, 0, sizeof(lksb));
ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
dlm_reco_ast, dlm, dlm_reco_bast);
mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
dlm->name, ret, lksb.status);
if (ret == DLM_NORMAL) {
mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
dlm->name, dlm->node_num);
/* got the EX lock. check to see if another node
* just became the reco master */
if (dlm_reco_master_ready(dlm)) {
mlog(0, "%s: got reco EX lock, but %u will "
"do the recovery\n", dlm->name,
dlm->reco.new_master);
status = -EEXIST;
} else {
status = 0;
/* see if recovery was already finished elsewhere */
spin_lock(&dlm->spinlock);
if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
status = -EINVAL;
mlog(0, "%s: got reco EX lock, but "
"node got recovered already\n", dlm->name);
if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
mlog(ML_ERROR, "%s: new master is %u "
"but no dead node!\n",
dlm->name, dlm->reco.new_master);
BUG();
}
}
spin_unlock(&dlm->spinlock);
}
/* if this node has actually become the recovery master,
* set the master and send the messages to begin recovery */
if (!status) {
mlog(0, "%s: dead=%u, this=%u, sending "
"begin_reco now\n", dlm->name,
dlm->reco.dead_node, dlm->node_num);
status = dlm_send_begin_reco_message(dlm,
dlm->reco.dead_node);
/* this always succeeds */
BUG_ON(status);
/* set the new_master to this node */
spin_lock(&dlm->spinlock);
dlm_set_reco_master(dlm, dlm->node_num);
spin_unlock(&dlm->spinlock);
}
/* recovery lock is a special case. ast will not get fired,
* so just go ahead and unlock it. */
ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
if (ret == DLM_DENIED) {
mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
}
if (ret != DLM_NORMAL) {
/* this would really suck. this could only happen
* if there was a network error during the unlock
* because of node death. this means the unlock
* is actually "done" and the lock structure is
* even freed. we can continue, but only
* because this specific lock name is special. */
mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
}
} else if (ret == DLM_NOTQUEUED) {
mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
dlm->name, dlm->node_num);
/* another node is master. wait on
* reco.new_master != O2NM_INVALID_NODE_NUM
* for at most one second */
wait_event_timeout(dlm->dlm_reco_thread_wq,
dlm_reco_master_ready(dlm),
msecs_to_jiffies(1000));
if (!dlm_reco_master_ready(dlm)) {
mlog(0, "%s: reco master taking awhile\n",
dlm->name);
goto again;
}
/* another node has informed this one that it is reco master */
mlog(0, "%s: reco master %u is ready to recover %u\n",
dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
status = -EEXIST;
} else if (ret == DLM_RECOVERING) {
mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
dlm->name, dlm->node_num);
goto again;
} else {
struct dlm_lock_resource *res;
/* dlmlock returned something other than NOTQUEUED or NORMAL */
mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
"lksb.status=%s\n", dlm->name, dlm_errname(ret),
dlm_errname(lksb.status));
res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
DLM_RECOVERY_LOCK_NAME_LEN);
if (res) {
dlm_print_one_lock_resource(res);
dlm_lockres_put(res);
} else {
mlog(ML_ERROR, "recovery lock not found\n");
}
BUG();
}
return status;
}
static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
{
struct dlm_begin_reco br;
int ret = 0;
struct dlm_node_iter iter;
int nodenum;
int status;
mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
spin_lock(&dlm->spinlock);
dlm_node_iter_init(dlm->domain_map, &iter);
spin_unlock(&dlm->spinlock);
clear_bit(dead_node, iter.node_map);
memset(&br, 0, sizeof(br));
br.node_idx = dlm->node_num;
br.dead_node = dead_node;
while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
ret = 0;
if (nodenum == dead_node) {
mlog(0, "not sending begin reco to dead node "
"%u\n", dead_node);
continue;
}
if (nodenum == dlm->node_num) {
mlog(0, "not sending begin reco to self\n");
continue;
}
retry:
ret = -EINVAL;
mlog(0, "attempting to send begin reco msg to %d\n",
nodenum);
ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
&br, sizeof(br), nodenum, &status);
/* negative status is handled ok by caller here */
if (ret >= 0)
ret = status;
if (dlm_is_host_down(ret)) {
/* node is down. not involved in recovery
* so just keep going */
mlog(ML_NOTICE, "%s: node %u was down when sending "
"begin reco msg (%d)\n", dlm->name, nodenum, ret);
ret = 0;
}
/*
* Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
* dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
* We are handling both for compatibility reasons.
*/
if (ret == -EAGAIN || ret == EAGAIN) {
mlog(0, "%s: trying to start recovery of node "
"%u, but node %u is waiting for last recovery "
"to complete, backoff for a bit\n", dlm->name,
dead_node, nodenum);
msleep(100);
goto retry;
}
if (ret < 0) {
struct dlm_lock_resource *res;
/* this is now a serious problem, possibly ENOMEM
* in the network stack. must retry */
mlog_errno(ret);
mlog(ML_ERROR, "begin reco of dlm %s to node %u "
"returned %d\n", dlm->name, nodenum, ret);
res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
DLM_RECOVERY_LOCK_NAME_LEN);
if (res) {
dlm_print_one_lock_resource(res);
dlm_lockres_put(res);
} else {
mlog(ML_ERROR, "recovery lock not found\n");
}
/* sleep for a bit in hopes that we can avoid
* another ENOMEM */
msleep(100);
goto retry;
}
}
return ret;
}
int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
/* ok to return 0, domain has gone away */
if (!dlm_grab(dlm))
return 0;
spin_lock(&dlm->spinlock);
if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
"but this node is in finalize state, waiting on finalize2\n",
dlm->name, br->node_idx, br->dead_node,
dlm->reco.dead_node, dlm->reco.new_master);
spin_unlock(&dlm->spinlock);
dlm_put(dlm);
return -EAGAIN;
}
spin_unlock(&dlm->spinlock);
mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
dlm->name, br->node_idx, br->dead_node,
dlm->reco.dead_node, dlm->reco.new_master);
dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
spin_lock(&dlm->spinlock);
if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
mlog(0, "%s: new_master %u died, changing "
"to %u\n", dlm->name, dlm->reco.new_master,
br->node_idx);
} else {
mlog(0, "%s: new_master %u NOT DEAD, changing "
"to %u\n", dlm->name, dlm->reco.new_master,
br->node_idx);
/* may not have seen the new master as dead yet */
}
}
if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
"node %u changing it to %u\n", dlm->name,
dlm->reco.dead_node, br->node_idx, br->dead_node);
}
dlm_set_reco_master(dlm, br->node_idx);
dlm_set_reco_dead_node(dlm, br->dead_node);
if (!test_bit(br->dead_node, dlm->recovery_map)) {
mlog(0, "recovery master %u sees %u as dead, but this "
"node has not yet. marking %u as dead\n",
br->node_idx, br->dead_node, br->dead_node);
if (!test_bit(br->dead_node, dlm->domain_map) ||
!test_bit(br->dead_node, dlm->live_nodes_map))
mlog(0, "%u not in domain/live_nodes map "
"so setting it in reco map manually\n",
br->dead_node);
/* force the recovery cleanup in __dlm_hb_node_down
* both of these will be cleared in a moment */
set_bit(br->dead_node, dlm->domain_map);
set_bit(br->dead_node, dlm->live_nodes_map);
__dlm_hb_node_down(dlm, br->dead_node);
}
spin_unlock(&dlm->spinlock);
dlm_kick_recovery_thread(dlm);
mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
dlm->name, br->node_idx, br->dead_node,
dlm->reco.dead_node, dlm->reco.new_master);
dlm_put(dlm);
return 0;
}
#define DLM_FINALIZE_STAGE2 0x01
static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
{
int ret = 0;
struct dlm_finalize_reco fr;
struct dlm_node_iter iter;
int nodenum;
int status;
int stage = 1;
mlog(0, "finishing recovery for node %s:%u, "
"stage %d\n", dlm->name, dlm->reco.dead_node, stage);
spin_lock(&dlm->spinlock);
dlm_node_iter_init(dlm->domain_map, &iter);
spin_unlock(&dlm->spinlock);
stage2:
memset(&fr, 0, sizeof(fr));
fr.node_idx = dlm->node_num;
fr.dead_node = dlm->reco.dead_node;
if (stage == 2)
fr.flags |= DLM_FINALIZE_STAGE2;
while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
if (nodenum == dlm->node_num)
continue;
ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
&fr, sizeof(fr), nodenum, &status);
if (ret >= 0)
ret = status;
if (ret < 0) {
mlog(ML_ERROR, "Error %d when sending message %u (key "
"0x%x) to node %u\n", ret, DLM_FINALIZE_RECO_MSG,
dlm->key, nodenum);
if (dlm_is_host_down(ret)) {
/* this has no effect on this recovery
* session, so set the status to zero to
* finish out the last recovery */
mlog(ML_ERROR, "node %u went down after this "
"node finished recovery.\n", nodenum);
ret = 0;
continue;
}
break;
}
}
if (stage == 1) {
/* reset the node_iter back to the top and send finalize2 */
iter.curnode = -1;
stage = 2;
goto stage2;
}
return ret;
}
int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_ctxt *dlm = data;
struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
int stage = 1;
/* ok to return 0, domain has gone away */
if (!dlm_grab(dlm))
return 0;
if (fr->flags & DLM_FINALIZE_STAGE2)
stage = 2;
mlog(0, "%s: node %u finalizing recovery stage%d of "
"node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
spin_lock(&dlm->spinlock);
if (dlm->reco.new_master != fr->node_idx) {
mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
"%u is supposed to be the new master, dead=%u\n",
fr->node_idx, dlm->reco.new_master, fr->dead_node);
BUG();
}
if (dlm->reco.dead_node != fr->dead_node) {
mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
"node %u, but node %u is supposed to be dead\n",
fr->node_idx, fr->dead_node, dlm->reco.dead_node);
BUG();
}
switch (stage) {
case 1:
dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
mlog(ML_ERROR, "%s: received finalize1 from "
"new master %u for dead node %u, but "
"this node has already received it!\n",
dlm->name, fr->node_idx, fr->dead_node);
dlm_print_reco_node_status(dlm);
BUG();
}
dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
spin_unlock(&dlm->spinlock);
break;
case 2:
if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
mlog(ML_ERROR, "%s: received finalize2 from "
"new master %u for dead node %u, but "
"this node did not have finalize1!\n",
dlm->name, fr->node_idx, fr->dead_node);
dlm_print_reco_node_status(dlm);
BUG();
}
dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
spin_unlock(&dlm->spinlock);
dlm_reset_recovery(dlm);
dlm_kick_recovery_thread(dlm);
break;
default:
BUG();
}
mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
dlm_put(dlm);
return 0;
}
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