kernel-ark/fs/dlm/recoverd.c
David Teigland 3ae1acf93a [DLM] add lock timeouts and warnings [2/6]
New features: lock timeouts and time warnings.  If the DLM_LKF_TIMEOUT
flag is set, then the request/conversion will be canceled after waiting
the specified number of centiseconds (specified per lock).  This feature
is only available for locks requested through libdlm (can be enabled for
kernel dlm users if there's a use for it.)

If the new DLM_LSFL_TIMEWARN flag is set when creating the lockspace, then
a warning message will be sent to userspace (using genetlink) after a
request/conversion has been waiting for a given number of centiseconds
(configurable per node).  The time warnings will be used in the future
to do deadlock detection in userspace.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09 08:22:33 +01:00

313 lines
6.9 KiB
C

/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
** of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/
#include "dlm_internal.h"
#include "lockspace.h"
#include "member.h"
#include "dir.h"
#include "ast.h"
#include "recover.h"
#include "lowcomms.h"
#include "lock.h"
#include "requestqueue.h"
#include "recoverd.h"
/* If the start for which we're re-enabling locking (seq) has been superseded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. */
static int enable_locking(struct dlm_ls *ls, uint64_t seq)
{
int error = -EINTR;
spin_lock(&ls->ls_recover_lock);
if (ls->ls_recover_seq == seq) {
set_bit(LSFL_RUNNING, &ls->ls_flags);
up_write(&ls->ls_in_recovery);
error = 0;
}
spin_unlock(&ls->ls_recover_lock);
return error;
}
static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
{
unsigned long start;
int error, neg = 0;
log_debug(ls, "recover %llx", (unsigned long long)rv->seq);
mutex_lock(&ls->ls_recoverd_active);
/*
* Suspending and resuming dlm_astd ensures that no lkb's from this ls
* will be processed by dlm_astd during recovery.
*/
dlm_astd_suspend();
dlm_astd_resume();
/*
* This list of root rsb's will be the basis of most of the recovery
* routines.
*/
dlm_create_root_list(ls);
/*
* Free all the tossed rsb's so we don't have to recover them.
*/
dlm_clear_toss_list(ls);
/*
* Add or remove nodes from the lockspace's ls_nodes list.
* Also waits for all nodes to complete dlm_recover_members.
*/
error = dlm_recover_members(ls, rv, &neg);
if (error) {
log_debug(ls, "recover_members failed %d", error);
goto fail;
}
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);
if (error) {
log_debug(ls, "recover_directory failed %d", error);
goto fail;
}
/*
* Wait for all nodes to complete directory rebuild.
*/
error = dlm_recover_directory_wait(ls);
if (error) {
log_debug(ls, "recover_directory_wait failed %d", error);
goto fail;
}
/*
* 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);
error = dlm_recovery_stopped(ls);
if (error)
goto fail;
if (neg || dlm_no_directory(ls)) {
/*
* Clear lkb's for departed nodes.
*/
dlm_purge_locks(ls);
/*
* Get new master nodeid's for rsb's that were mastered on
* departed nodes.
*/
error = dlm_recover_masters(ls);
if (error) {
log_debug(ls, "recover_masters failed %d", error);
goto fail;
}
/*
* Send our locks on remastered rsb's to the new masters.
*/
error = dlm_recover_locks(ls);
if (error) {
log_debug(ls, "recover_locks failed %d", error);
goto fail;
}
error = dlm_recover_locks_wait(ls);
if (error) {
log_debug(ls, "recover_locks_wait failed %d", error);
goto fail;
}
/*
* Finalize state in master rsb's now that all locks can be
* checked. This includes conversion resolution and lvb
* settings.
*/
dlm_recover_rsbs(ls);
} 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);
if (error) {
log_debug(ls, "recover_locks_wait failed %d", error);
goto fail;
}
}
dlm_release_root_list(ls);
/*
* 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);
if (error) {
log_debug(ls, "recover_done_wait failed %d", error);
goto fail;
}
dlm_clear_members_gone(ls);
dlm_adjust_timeouts(ls);
error = enable_locking(ls, rv->seq);
if (error) {
log_debug(ls, "enable_locking failed %d", error);
goto fail;
}
error = dlm_process_requestqueue(ls);
if (error) {
log_debug(ls, "process_requestqueue failed %d", error);
goto fail;
}
error = dlm_recover_waiters_post(ls);
if (error) {
log_debug(ls, "recover_waiters_post failed %d", error);
goto fail;
}
dlm_grant_after_purge(ls);
dlm_astd_wake();
log_debug(ls, "recover %llx done: %u ms",
(unsigned long long)rv->seq,
jiffies_to_msecs(jiffies - start));
mutex_unlock(&ls->ls_recoverd_active);
return 0;
fail:
dlm_release_root_list(ls);
log_debug(ls, "recover %llx error %d",
(unsigned long long)rv->seq, error);
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;
spin_lock(&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_RECOVERY_STOP, &ls->ls_flags);
spin_unlock(&ls->ls_recover_lock);
if (rv) {
ls_recover(ls, rv);
kfree(rv->nodeids);
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;
}
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (!test_bit(LSFL_WORK, &ls->ls_flags))
schedule();
set_current_state(TASK_RUNNING);
if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags))
do_ls_recovery(ls);
}
dlm_put_lockspace(ls);
return 0;
}
void dlm_recoverd_kick(struct dlm_ls *ls)
{
set_bit(LSFL_WORK, &ls->ls_flags);
wake_up_process(ls->ls_recoverd_task);
}
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);
}