fs/dlm/recoverd.c - linux - Git at Google

 // 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"


 /* If the start for which we're re-enabling locking (seq) has been superseded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;

 	down_write(&ls->ls_recv_active);

 	spin_lock(&ls->ls_recover_lock);
 	if (ls->ls_recover_seq == seq) {
 		set_bit(LSFL_RUNNING, &ls->ls_flags);
 		/* 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(&ls->ls_recover_lock);

 	up_write(&ls->ls_recv_active);
 	return error;
 }

 static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 {
 	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_toss(ls);

 	/*
 	 * This list of root rsb's will be the basis of most of the recovery
 	 * routines.
 	 */

 	dlm_create_root_list(ls);

 	/*
 	 * 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);

 	ls->ls_recover_dir_sent_res = 0;
 	ls->ls_recover_dir_sent_msg = 0;
 	ls->ls_recover_locks_in = 0;

 	dlm_set_recover_status(ls, DLM_RS_NODES);

 	error = dlm_recover_members_wait(ls);
 	if (error) {
 		log_rinfo(ls, "dlm_recover_members_wait error %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_rinfo(ls, "dlm_recover_directory error %d", error);
 		goto fail;
 	}

 	dlm_set_recover_status(ls, DLM_RS_DIR);

 	error = dlm_recover_directory_wait(ls);
 	if (error) {
 		log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
 		goto fail;
 	}

 	log_rinfo(ls, "dlm_recover_directory %u out %u messages",
 		  ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);

 	/*
 	 * 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;
 	}

 	if (neg || dlm_no_directory(ls)) {
 		/*
 		 * Clear lkb's for departed nodes.
 		 */

 		dlm_recover_purge(ls);

 		/*
 		 * Get new master nodeid's for rsb's that were mastered on
 		 * departed nodes.
 		 */

 		error = dlm_recover_masters(ls);
 		if (error) {
 			log_rinfo(ls, "dlm_recover_masters error %d", error);
 			goto fail;
 		}

 		/*
 		 * Send our locks on remastered rsb's to the new masters.
 		 */

 		error = dlm_recover_locks(ls);
 		if (error) {
 			log_rinfo(ls, "dlm_recover_locks error %d", error);
 			goto fail;
 		}

 		dlm_set_recover_status(ls, DLM_RS_LOCKS);

 		error = dlm_recover_locks_wait(ls);
 		if (error) {
 			log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
 			goto fail;
 		}

 		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);
 	} 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_rinfo(ls, "dlm_recover_locks_wait error %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_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:
 	dlm_release_root_list(ls);
 	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(&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(&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);
 }
	// 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"


	/* 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;

	down_write(&ls->ls_recv_active);

	spin_lock(&ls->ls_recover_lock);
	if (ls->ls_recover_seq == seq) {
	set_bit(LSFL_RUNNING, &ls->ls_flags);
	/* 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(&ls->ls_recover_lock);

	up_write(&ls->ls_recv_active);
	return error;
	}

	static int ls_recover(struct dlm_ls ls, struct dlm_recover rv)
	{
	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_toss(ls);

	/*
	* This list of root rsb's will be the basis of most of the recovery
	* routines.
	*/

	dlm_create_root_list(ls);

	/*
	* 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);

	ls->ls_recover_dir_sent_res = 0;
	ls->ls_recover_dir_sent_msg = 0;
	ls->ls_recover_locks_in = 0;

	dlm_set_recover_status(ls, DLM_RS_NODES);

	error = dlm_recover_members_wait(ls);
	if (error) {
	log_rinfo(ls, "dlm_recover_members_wait error %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_rinfo(ls, "dlm_recover_directory error %d", error);
	goto fail;
	}

	dlm_set_recover_status(ls, DLM_RS_DIR);

	error = dlm_recover_directory_wait(ls);
	if (error) {
	log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
	goto fail;
	}

	log_rinfo(ls, "dlm_recover_directory %u out %u messages",
	ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);

	/*
	* 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;
	}

	if (neg \|\| dlm_no_directory(ls)) {
	/*
	* Clear lkb's for departed nodes.
	*/

	dlm_recover_purge(ls);

	/*
	* Get new master nodeid's for rsb's that were mastered on
	* departed nodes.
	*/

	error = dlm_recover_masters(ls);
	if (error) {
	log_rinfo(ls, "dlm_recover_masters error %d", error);
	goto fail;
	}

	/*
	* Send our locks on remastered rsb's to the new masters.
	*/

	error = dlm_recover_locks(ls);
	if (error) {
	log_rinfo(ls, "dlm_recover_locks error %d", error);
	goto fail;
	}

	dlm_set_recover_status(ls, DLM_RS_LOCKS);

	error = dlm_recover_locks_wait(ls);
	if (error) {
	log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
	goto fail;
	}

	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);
	} 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_rinfo(ls, "dlm_recover_locks_wait error %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_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:
	dlm_release_root_list(ls);
	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(&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(&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);
	}