WSL2-Linux-Kernel/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-%s", dlm->name);
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);
ocfs2: dlm: fix recovery hung There is a race window in dlm_do_recovery() between dlm_remaster_locks() and dlm_reset_recovery() when the recovery master nearly finish the recovery process for a dead node. After the master sends FINALIZE_RECO message in dlm_remaster_locks(), another node may become the recovery master for another dead node, and then send the BEGIN_RECO message to all the nodes included the old master, in the handler of this message dlm_begin_reco_handler() of old master, dlm->reco.dead_node and dlm->reco.new_master will be set to the second dead node and the new master, then in dlm_reset_recovery(), these two variables will be reset to default value. This will cause new recovery master can not finish the recovery process and hung, at last the whole cluster will hung for recovery. old recovery master: new recovery master: dlm_remaster_locks() become recovery master for another dead node. dlm_send_begin_reco_message() dlm_begin_reco_handler() { if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) { return -EAGAIN; } dlm_set_reco_master(dlm, br->node_idx); dlm_set_reco_dead_node(dlm, br->dead_node); } dlm_reset_recovery() { dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM); dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM); } will hang in dlm_remaster_locks() for request dlm locks info Before send FINALIZE_RECO message, recovery master should set DLM_RECO_STATE_FINALIZE for itself and clear it after the recovery done, this can break the race windows as the BEGIN_RECO messages will not be handled before DLM_RECO_STATE_FINALIZE flag is cleared. A similar race may happen between new recovery master and normal node which is in dlm_finalize_reco_handler(), also fix it. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:51 +04:00
spin_lock(&dlm->spinlock);
__dlm_reset_recovery(dlm);
dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
spin_unlock(&dlm->spinlock);
}
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;
ocfs2: dlm: fix recovery hung There is a race window in dlm_do_recovery() between dlm_remaster_locks() and dlm_reset_recovery() when the recovery master nearly finish the recovery process for a dead node. After the master sends FINALIZE_RECO message in dlm_remaster_locks(), another node may become the recovery master for another dead node, and then send the BEGIN_RECO message to all the nodes included the old master, in the handler of this message dlm_begin_reco_handler() of old master, dlm->reco.dead_node and dlm->reco.new_master will be set to the second dead node and the new master, then in dlm_reset_recovery(), these two variables will be reset to default value. This will cause new recovery master can not finish the recovery process and hung, at last the whole cluster will hung for recovery. old recovery master: new recovery master: dlm_remaster_locks() become recovery master for another dead node. dlm_send_begin_reco_message() dlm_begin_reco_handler() { if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) { return -EAGAIN; } dlm_set_reco_master(dlm, br->node_idx); dlm_set_reco_dead_node(dlm, br->dead_node); } dlm_reset_recovery() { dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM); dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM); } will hang in dlm_remaster_locks() for request dlm locks info Before send FINALIZE_RECO message, recovery master should set DLM_RECO_STATE_FINALIZE for itself and clear it after the recovery done, this can break the race windows as the BEGIN_RECO messages will not be handled before DLM_RECO_STATE_FINALIZE flag is cleared. A similar race may happen between new recovery master and normal node which is in dlm_finalize_reco_handler(), also fix it. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:51 +04:00
/* Set this flag on recovery master to avoid
* a new recovery for another dead node start
* before the recovery is not done. That may
* cause recovery hung.*/
spin_lock(&dlm->spinlock);
dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
spin_unlock(&dlm->spinlock);
/* 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);
/* Can't schedule DLM_UNLOCK_FREE_LOCK
* - do manually */
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;
unsigned int hash;
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. */
hash = dlm_lockid_hash(mres->lockname, mres->lockname_len);
spin_lock(&dlm->spinlock);
res = __dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len,
hash);
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);
spin_unlock(&dlm->spinlock);
dlm_lockres_put(res);
goto leave;
}
res->state |= DLM_LOCK_RES_MIGRATING;
}
spin_unlock(&res->spinlock);
spin_unlock(&dlm->spinlock);
} else {
spin_unlock(&dlm->spinlock);
/* 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);
resend:
ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
&req, sizeof(req), nodenum, &status);
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 if (status == -ENOMEM) {
mlog_errno(status);
msleep(50);
goto resend;
} 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;
int dispatched = 0;
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(ret);
spin_unlock(&res->spinlock);
dlm_lockres_put(res);
spin_unlock(&dlm->spinlock);
dlm_put(dlm);
/* sender will take care of this and retry */
return ret;
} else {
dispatched = 1;
__dlm_lockres_grab_inflight_worker(dlm, res);
spin_unlock(&res->spinlock);
}
} else {
/* put.. incase we are not the master */
spin_unlock(&res->spinlock);
dlm_lockres_put(res);
}
}
spin_unlock(&dlm->spinlock);
if (!dispatched)
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, *iter;
struct list_head *tmpq = NULL;
struct dlm_lock *newlock = NULL;
struct dlm_lockstatus *lksb = NULL;
int ret = 0;
int i, j, bad;
ocfs2: dlm: fix lock migration crash This issue was introduced by commit 800deef3f6f8 ("ocfs2: use list_for_each_entry where benefical") in 2007 where it replaced list_for_each with list_for_each_entry. The variable "lock" will point to invalid data if "tmpq" list is empty and a panic will be triggered due to this. Sunil advised reverting it back, but the old version was also not right. At the end of the outer for loop, that list_for_each_entry will also set "lock" to an invalid data, then in the next loop, if the "tmpq" list is empty, "lock" will be an stale invalid data and cause the panic. So reverting the list_for_each back and reset "lock" to NULL to fix this issue. Another concern is that this seemes can not happen because the "tmpq" list should not be empty. Let me describe how. old lock resource owner(node 1): migratation target(node 2): image there's lockres with a EX lock from node 2 in granted list, a NR lock from node x with convert_type EX in converting list. dlm_empty_lockres() { dlm_pick_migration_target() { pick node 2 as target as its lock is the first one in granted list. } dlm_migrate_lockres() { dlm_mark_lockres_migrating() { res->state |= DLM_LOCK_RES_BLOCK_DIRTY; wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); //after the above code, we can not dirty lockres any more, // so dlm_thread shuffle list will not run downconvert lock from EX to NR upconvert lock from NR to EX <<< migration may schedule out here, then <<< node 2 send down convert request to convert type from EX to <<< NR, then send up convert request to convert type from NR to <<< EX, at this time, lockres granted list is empty, and two locks <<< in the converting list, node x up convert lock followed by <<< node 2 up convert lock. // will set lockres RES_MIGRATING flag, the following // lock/unlock can not run dlm_lockres_release_ast(dlm, res); } dlm_send_one_lockres() dlm_process_recovery_data() for (i=0; i<mres->num_locks; i++) if (ml->node == dlm->node_num) for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) { list_for_each_entry(lock, tmpq, list) if (lock) break; <<< lock is invalid as grant list is empty. } if (lock->ml.node != ml->node) BUG() >>> crash here } I see the above locks status from a vmcore of our internal bug. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:49 +04:00
struct dlm_lock *lock;
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));
ocfs2: dlm: fix lock migration crash This issue was introduced by commit 800deef3f6f8 ("ocfs2: use list_for_each_entry where benefical") in 2007 where it replaced list_for_each with list_for_each_entry. The variable "lock" will point to invalid data if "tmpq" list is empty and a panic will be triggered due to this. Sunil advised reverting it back, but the old version was also not right. At the end of the outer for loop, that list_for_each_entry will also set "lock" to an invalid data, then in the next loop, if the "tmpq" list is empty, "lock" will be an stale invalid data and cause the panic. So reverting the list_for_each back and reset "lock" to NULL to fix this issue. Another concern is that this seemes can not happen because the "tmpq" list should not be empty. Let me describe how. old lock resource owner(node 1): migratation target(node 2): image there's lockres with a EX lock from node 2 in granted list, a NR lock from node x with convert_type EX in converting list. dlm_empty_lockres() { dlm_pick_migration_target() { pick node 2 as target as its lock is the first one in granted list. } dlm_migrate_lockres() { dlm_mark_lockres_migrating() { res->state |= DLM_LOCK_RES_BLOCK_DIRTY; wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); //after the above code, we can not dirty lockres any more, // so dlm_thread shuffle list will not run downconvert lock from EX to NR upconvert lock from NR to EX <<< migration may schedule out here, then <<< node 2 send down convert request to convert type from EX to <<< NR, then send up convert request to convert type from NR to <<< EX, at this time, lockres granted list is empty, and two locks <<< in the converting list, node x up convert lock followed by <<< node 2 up convert lock. // will set lockres RES_MIGRATING flag, the following // lock/unlock can not run dlm_lockres_release_ast(dlm, res); } dlm_send_one_lockres() dlm_process_recovery_data() for (i=0; i<mres->num_locks; i++) if (ml->node == dlm->node_num) for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) { list_for_each_entry(lock, tmpq, list) if (lock) break; <<< lock is invalid as grant list is empty. } if (lock->ml.node != ml->node) BUG() >>> crash here } I see the above locks status from a vmcore of our internal bug. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:49 +04:00
lock = NULL;
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(iter, tmpq) {
lock = list_entry(iter,
struct dlm_lock, list);
ocfs2: dlm: fix lock migration crash This issue was introduced by commit 800deef3f6f8 ("ocfs2: use list_for_each_entry where benefical") in 2007 where it replaced list_for_each with list_for_each_entry. The variable "lock" will point to invalid data if "tmpq" list is empty and a panic will be triggered due to this. Sunil advised reverting it back, but the old version was also not right. At the end of the outer for loop, that list_for_each_entry will also set "lock" to an invalid data, then in the next loop, if the "tmpq" list is empty, "lock" will be an stale invalid data and cause the panic. So reverting the list_for_each back and reset "lock" to NULL to fix this issue. Another concern is that this seemes can not happen because the "tmpq" list should not be empty. Let me describe how. old lock resource owner(node 1): migratation target(node 2): image there's lockres with a EX lock from node 2 in granted list, a NR lock from node x with convert_type EX in converting list. dlm_empty_lockres() { dlm_pick_migration_target() { pick node 2 as target as its lock is the first one in granted list. } dlm_migrate_lockres() { dlm_mark_lockres_migrating() { res->state |= DLM_LOCK_RES_BLOCK_DIRTY; wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); //after the above code, we can not dirty lockres any more, // so dlm_thread shuffle list will not run downconvert lock from EX to NR upconvert lock from NR to EX <<< migration may schedule out here, then <<< node 2 send down convert request to convert type from EX to <<< NR, then send up convert request to convert type from NR to <<< EX, at this time, lockres granted list is empty, and two locks <<< in the converting list, node x up convert lock followed by <<< node 2 up convert lock. // will set lockres RES_MIGRATING flag, the following // lock/unlock can not run dlm_lockres_release_ast(dlm, res); } dlm_send_one_lockres() dlm_process_recovery_data() for (i=0; i<mres->num_locks; i++) if (ml->node == dlm->node_num) for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) { list_for_each_entry(lock, tmpq, list) if (lock) break; <<< lock is invalid as grant list is empty. } if (lock->ml.node != ml->node) BUG() >>> crash here } I see the above locks status from a vmcore of our internal bug. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:49 +04:00
if (lock->ml.cookie == ml->cookie)
break;
ocfs2: dlm: fix lock migration crash This issue was introduced by commit 800deef3f6f8 ("ocfs2: use list_for_each_entry where benefical") in 2007 where it replaced list_for_each with list_for_each_entry. The variable "lock" will point to invalid data if "tmpq" list is empty and a panic will be triggered due to this. Sunil advised reverting it back, but the old version was also not right. At the end of the outer for loop, that list_for_each_entry will also set "lock" to an invalid data, then in the next loop, if the "tmpq" list is empty, "lock" will be an stale invalid data and cause the panic. So reverting the list_for_each back and reset "lock" to NULL to fix this issue. Another concern is that this seemes can not happen because the "tmpq" list should not be empty. Let me describe how. old lock resource owner(node 1): migratation target(node 2): image there's lockres with a EX lock from node 2 in granted list, a NR lock from node x with convert_type EX in converting list. dlm_empty_lockres() { dlm_pick_migration_target() { pick node 2 as target as its lock is the first one in granted list. } dlm_migrate_lockres() { dlm_mark_lockres_migrating() { res->state |= DLM_LOCK_RES_BLOCK_DIRTY; wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); //after the above code, we can not dirty lockres any more, // so dlm_thread shuffle list will not run downconvert lock from EX to NR upconvert lock from NR to EX <<< migration may schedule out here, then <<< node 2 send down convert request to convert type from EX to <<< NR, then send up convert request to convert type from NR to <<< EX, at this time, lockres granted list is empty, and two locks <<< in the converting list, node x up convert lock followed by <<< node 2 up convert lock. // will set lockres RES_MIGRATING flag, the following // lock/unlock can not run dlm_lockres_release_ast(dlm, res); } dlm_send_one_lockres() dlm_process_recovery_data() for (i=0; i<mres->num_locks; i++) if (ml->node == dlm->node_num) for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) { list_for_each_entry(lock, tmpq, list) if (lock) break; <<< lock is invalid as grant list is empty. } if (lock->ml.node != ml->node) BUG() >>> crash here } I see the above locks status from a vmcore of our internal bug. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:49 +04:00
lock = NULL;
}
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);
ocfs2/dlm: fix possible convert=sion deadlock We found there is a conversion deadlock when the owner of lockres happened to crash before send DLM_PROXY_AST_MSG for a downconverting lock. The situation is as follows: Node1 Node2 Node3 the owner of lockresA lock_1 granted at EX mode and call ocfs2_cluster_unlock to decrease ex_holders. converting lock_3 from NL to EX send DLM_PROXY_AST_MSG to Node1, asking Node 1 to downconvert. receiving DLM_PROXY_AST_MSG, thread ocfs2dc send DLM_CONVERT_LOCK_MSG to Node2 to downconvert lock_1(EX->NL). lock_1 can be granted and put it into pending_asts list, return DLM_NORMAL. then something happened and Node2 crashed. received DLM_NORMAL, waiting for DLM_PROXY_AST_MSG. selected as the recovery master, receving migrate lock from Node1, queue lock_1 to the tail of converting list. After dlm recovery, converting list in the master of lockresA(Node3) will be: converting list head <-> lock_3(NL->EX) <->lock_1(EX<->NL). Requested mode of lock_3 is not compatible with the granted mode of lock_1, so it can not be granted. and lock_1 can not downconvert because covnerting queue is strictly FIFO. So a deadlock is created. We think function dlm_process_recovery_data() should queue_ast for lock_1 or alter the order of lock_1 and lock_3, so dlm_thread can process lock_1 first. And if there are multiple downconverting locks, they must convert form PR to NL, so no need to sort them. Signed-off-by: joyce.xue <xuejiufei@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 03:06:10 +04:00
if (mres->flags & DLM_MRES_RECOVERY &&
ml->list == DLM_CONVERTING_LIST &&
newlock->ml.type >
newlock->ml.convert_type) {
/* newlock is doing downconvert, add it to the
* head of converting list */
list_add(&newlock->list, queue);
} else
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);
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: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 05:06:00 +04:00
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: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 05:06:00 +04:00
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);
/* Can't schedule
* DLM_UNLOCK_FREE_LOCK
* - do manually */
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;
ocfs2: dlm: fix recovery hung There is a race window in dlm_do_recovery() between dlm_remaster_locks() and dlm_reset_recovery() when the recovery master nearly finish the recovery process for a dead node. After the master sends FINALIZE_RECO message in dlm_remaster_locks(), another node may become the recovery master for another dead node, and then send the BEGIN_RECO message to all the nodes included the old master, in the handler of this message dlm_begin_reco_handler() of old master, dlm->reco.dead_node and dlm->reco.new_master will be set to the second dead node and the new master, then in dlm_reset_recovery(), these two variables will be reset to default value. This will cause new recovery master can not finish the recovery process and hung, at last the whole cluster will hung for recovery. old recovery master: new recovery master: dlm_remaster_locks() become recovery master for another dead node. dlm_send_begin_reco_message() dlm_begin_reco_handler() { if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) { return -EAGAIN; } dlm_set_reco_master(dlm, br->node_idx); dlm_set_reco_dead_node(dlm, br->dead_node); } dlm_reset_recovery() { dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM); dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM); } will hang in dlm_remaster_locks() for request dlm locks info Before send FINALIZE_RECO message, recovery master should set DLM_RECO_STATE_FINALIZE for itself and clear it after the recovery done, this can break the race windows as the BEGIN_RECO messages will not be handled before DLM_RECO_STATE_FINALIZE flag is cleared. A similar race may happen between new recovery master and normal node which is in dlm_finalize_reco_handler(), also fix it. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 01:46:51 +04:00
__dlm_reset_recovery(dlm);
spin_unlock(&dlm->spinlock);
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;
}