// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
**
**
*******************************************************************************
******************************************************************************/
#include "dlm_internal.h"
#include "lockspace.h"
#include "member.h"
#include "dir.h"
#include "ast.h"
#include "recover.h"
#include "lowcomms.h"
#include "lock.h"
#include "requestqueue.h"
#include "recoverd.h"
static int dlm_create_masters_list(struct dlm_ls *ls)
{
struct dlm_rsb *r;
int error = 0;
write_lock_bh(&ls->ls_masters_lock);
if (!list_empty(&ls->ls_masters_list)) {
log_error(ls, "root list not empty");
error = -EINVAL;
goto out;
}
read_lock_bh(&ls->ls_rsbtbl_lock);
list_for_each_entry(r, &ls->ls_slow_active, res_slow_list) {
if (r->res_nodeid)
continue;
list_add(&r->res_masters_list, &ls->ls_masters_list);
dlm_hold_rsb(r);
}
read_unlock_bh(&ls->ls_rsbtbl_lock);
out:
write_unlock_bh(&ls->ls_masters_lock);
return error;
}
static void dlm_release_masters_list(struct dlm_ls *ls)
{
struct dlm_rsb *r, *safe;
write_lock_bh(&ls->ls_masters_lock);
list_for_each_entry_safe(r, safe, &ls->ls_masters_list, res_masters_list) {
list_del_init(&r->res_masters_list);
dlm_put_rsb(r);
}
write_unlock_bh(&ls->ls_masters_lock);
}
static void dlm_create_root_list(struct dlm_ls *ls, struct list_head *root_list)
{
struct dlm_rsb *r;
read_lock_bh(&ls->ls_rsbtbl_lock);
list_for_each_entry(r, &ls->ls_slow_active, res_slow_list) {
list_add(&r->res_root_list, root_list);
dlm_hold_rsb(r);
}
WARN_ON_ONCE(!list_empty(&ls->ls_slow_inactive));
read_unlock_bh(&ls->ls_rsbtbl_lock);
}
static void dlm_release_root_list(struct list_head *root_list)
{
struct dlm_rsb *r, *safe;
list_for_each_entry_safe(r, safe, root_list, res_root_list) {
list_del_init(&r->res_root_list);
dlm_put_rsb(r);
}
}
/* If the start for which we're re-enabling locking (seq) has been superseded
by a newer stop (ls_recover_seq), we need to leave locking disabled.
We suspend dlm_recv threads here to avoid the race where dlm_recv a) sees
locking stopped and b) adds a message to the requestqueue, but dlm_recoverd
enables locking and clears the requestqueue between a and b. */
static int enable_locking(struct dlm_ls *ls, uint64_t seq)
{
int error = -EINTR;
write_lock_bh(&ls->ls_recv_active);
spin_lock_bh(&ls->ls_recover_lock);
if (ls->ls_recover_seq == seq) {
set_bit(LSFL_RUNNING, &ls->ls_flags);
/* Schedule next timer if recovery put something on inactive.
*
* The rsbs that was queued while recovery on toss hasn't
* started yet because LSFL_RUNNING was set everything
* else recovery hasn't started as well because ls_in_recovery
* is still hold. So we should not run into the case that
* resume_scan_timer() queues a timer that can occur in
* a no op.
*/
resume_scan_timer(ls);
/* unblocks processes waiting to enter the dlm */
up_write(&ls->ls_in_recovery);
clear_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
error = 0;
}
spin_unlock_bh(&ls->ls_recover_lock);
write_unlock_bh(&ls->ls_recv_active);
return error;
}
static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
{
LIST_HEAD(root_list);
unsigned long start;
int error, neg = 0;
log_rinfo(ls, "dlm_recover %llu", (unsigned long long)rv->seq);
mutex_lock(&ls->ls_recoverd_active);
dlm_callback_suspend(ls);
dlm_clear_inactive(ls);
/*
* This list of root rsb's will be the basis of most of the recovery
* routines.
*/
dlm_create_root_list(ls, &root_list);
/*
* Add or remove nodes from the lockspace's ls_nodes list.
*
* Due to the fact that we must report all membership changes to lsops
* or midcomms layer, it is not permitted to abort ls_recover() until
* this is done.
*/
error = dlm_recover_members(ls, rv, &neg);
if (error) {
log_rinfo(ls, "dlm_recover_members error %d", error);
goto fail;
}
dlm_recover_dir_nodeid(ls, &root_list);
/* Create a snapshot of all active rsbs were we are the master of.
* During the barrier between dlm_recover_members_wait() and
* dlm_recover_directory() other nodes can dump their necessary
* directory dlm_rsb (r->res_dir_nodeid == nodeid) in rcom
* communication dlm_copy_master_names() handling.
*
* TODO We should create a per lockspace list that contains rsbs
* that we are the master of. Instead of creating this list while
* recovery we keep track of those rsbs while locking handling and
* recovery can use it when necessary.
*/
error = dlm_create_masters_list(ls);
if (error) {
log_rinfo(ls, "dlm_create_masters_list error %d", error);
goto fail_root_list;
}
ls->ls_recover_locks_in = 0;
dlm_set_recover_status(ls, DLM_RS_NODES);
error = dlm_recover_members_wait(ls, rv->seq);
if (error) {
log_rinfo(ls, "dlm_recover_members_wait error %d", error);
dlm_release_masters_list(ls);
goto fail_root_list;
}
start = jiffies;
/*
* Rebuild our own share of the directory by collecting from all other
* nodes their master rsb names that hash to us.
*/
error = dlm_recover_directory(ls, rv->seq);
if (error) {
log_rinfo(ls, "dlm_recover_directory error %d", error);
dlm_release_masters_list(ls);
goto fail_root_list;
}
dlm_set_recover_status(ls, DLM_RS_DIR);
error = dlm_recover_directory_wait(ls, rv->seq);
if (error) {
log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
dlm_release_masters_list(ls);
goto fail_root_list;
}
dlm_release_masters_list(ls);
/*
* We may have outstanding operations that are waiting for a reply from
* a failed node. Mark these to be resent after recovery. Unlock and
* cancel ops can just be completed.
*/
dlm_recover_waiters_pre(ls);
if (dlm_recovery_stopped(ls)) {
error = -EINTR;
goto fail_root_list;
}
if (neg || dlm_no_directory(ls)) {
/*
* Clear lkb's for departed nodes.
*/
dlm_recover_purge(ls, &root_list);
/*
* Get new master nodeid's for rsb's that were mastered on
* departed nodes.
*/
error = dlm_recover_masters(ls, rv->seq, &root_list);
if (error) {
log_rinfo(ls, "dlm_recover_masters error %d", error);
goto fail_root_list;
}
/*
* Send our locks on remastered rsb's to the new masters.
*/
error = dlm_recover_locks(ls, rv->seq, &root_list);
if (error) {
log_rinfo(ls, "dlm_recover_locks error %d", error);
goto fail_root_list;
}
dlm_set_recover_status(ls, DLM_RS_LOCKS);
error = dlm_recover_locks_wait(ls, rv->seq);
if (error) {
log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
goto fail_root_list;
}
log_rinfo(ls, "dlm_recover_locks %u in",
ls->ls_recover_locks_in);
/*
* Finalize state in master rsb's now that all locks can be
* checked. This includes conversion resolution and lvb
* settings.
*/
dlm_recover_rsbs(ls, &root_list);
} else {
/*
* Other lockspace members may be going through the "neg" steps
* while also adding us to the lockspace, in which case they'll
* be doing the recover_locks (RS_LOCKS) barrier.
*/
dlm_set_recover_status(ls, DLM_RS_LOCKS);
error = dlm_recover_locks_wait(ls, rv->seq);
if (error) {
log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
goto fail_root_list;
}
}
dlm_release_root_list(&root_list);
/*
* Purge directory-related requests that are saved in requestqueue.
* All dir requests from before recovery are invalid now due to the dir
* rebuild and will be resent by the requesting nodes.
*/
dlm_purge_requestqueue(ls);
dlm_set_recover_status(ls, DLM_RS_DONE);
error = dlm_recover_done_wait(ls, rv->seq);
if (error) {
log_rinfo(ls, "dlm_recover_done_wait error %d", error);
goto fail;
}
dlm_clear_members_gone(ls);
dlm_callback_resume(ls);
error = enable_locking(ls, rv->seq);
if (error) {
log_rinfo(ls, "enable_locking error %d", error);
goto fail;
}
error = dlm_process_requestqueue(ls);
if (error) {
log_rinfo(ls, "dlm_process_requestqueue error %d", error);
goto fail;
}
error = dlm_recover_waiters_post(ls);
if (error) {
log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
goto fail;
}
dlm_recover_grant(ls);
log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
(unsigned long long)rv->seq, ls->ls_generation,
jiffies_to_msecs(jiffies - start));
mutex_unlock(&ls->ls_recoverd_active);
return 0;
fail_root_list:
dlm_release_root_list(&root_list);
fail:
mutex_unlock(&ls->ls_recoverd_active);
return error;
}
/* The dlm_ls_start() that created the rv we take here may already have been
stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
flag set. */
static void do_ls_recovery(struct dlm_ls *ls)
{
struct dlm_recover *rv = NULL;
int error;
spin_lock_bh(&ls->ls_recover_lock);
rv = ls->ls_recover_args;
ls->ls_recover_args = NULL;
if (rv && ls->ls_recover_seq == rv->seq)
clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
spin_unlock_bh(&ls->ls_recover_lock);
if (rv) {
error = ls_recover(ls, rv);
switch (error) {
case 0:
ls->ls_recovery_result = 0;
complete(&ls->ls_recovery_done);
dlm_lsop_recover_done(ls);
break;
case -EINTR:
/* if recovery was interrupted -EINTR we wait for the next
* ls_recover() iteration until it hopefully succeeds.
*/
log_rinfo(ls, "%s %llu interrupted and should be queued to run again",
__func__, (unsigned long long)rv->seq);
break;
default:
log_rinfo(ls, "%s %llu error %d", __func__,
(unsigned long long)rv->seq, error);
/* let new_lockspace() get aware of critical error */
ls->ls_recovery_result = error;
complete(&ls->ls_recovery_done);
break;
}
kfree(rv->nodes);
kfree(rv);
}
}
static int dlm_recoverd(void *arg)
{
struct dlm_ls *ls;
ls = dlm_find_lockspace_local(arg);
if (!ls) {
log_print("dlm_recoverd: no lockspace %p", arg);
return -1;
}
down_write(&ls->ls_in_recovery);
set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
wake_up(&ls->ls_recover_lock_wait);
while (1) {
/*
* We call kthread_should_stop() after set_current_state().
* This is because it works correctly if kthread_stop() is
* called just before set_current_state().
*/
set_current_state(TASK_INTERRUPTIBLE);
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
break;
}
if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
!test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
if (kthread_should_stop())
break;
schedule();
}
set_current_state(TASK_RUNNING);
if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
down_write(&ls->ls_in_recovery);
set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
wake_up(&ls->ls_recover_lock_wait);
}
if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
do_ls_recovery(ls);
}
if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
up_write(&ls->ls_in_recovery);
dlm_put_lockspace(ls);
return 0;
}
int dlm_recoverd_start(struct dlm_ls *ls)
{
struct task_struct *p;
int error = 0;
p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
if (IS_ERR(p))
error = PTR_ERR(p);
else
ls->ls_recoverd_task = p;
return error;
}
void dlm_recoverd_stop(struct dlm_ls *ls)
{
kthread_stop(ls->ls_recoverd_task);
}
void dlm_recoverd_suspend(struct dlm_ls *ls)
{
wake_up(&ls->ls_wait_general);
mutex_lock(&ls->ls_recoverd_active);
}
void dlm_recoverd_resume(struct dlm_ls *ls)
{
mutex_unlock(&ls->ls_recoverd_active);
}
Codebase Browser
linux