Commit e98a235f authored by Yu Kuai's avatar Yu Kuai Committed by Jialin Zhang
Browse files

md: refactor action_store() for 'idle' and 'frozen' 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6OMCC


CVE: NA

--------------------------------

Prepare to handle 'idle' and 'frozen' differently to fix a deadlock, there
are no functional changes except that MD_RECOVERY_RUNNING is checked
again after 'reconfig_mutex' is held.

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarHou Tao <houtao1@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parent 4a53e631

drivers/md/md.c

+45 −16
Original line number Diff line number Diff line
@@ -4855,29 +4855,58 @@ action_show(struct mddev *mddev, char *page) 
	return sprintf(page, "%s\n", type);

}



static ssize_t

action_store(struct mddev *mddev, const char *page, size_t len)

static void stop_sync_thread(struct mddev *mddev)

{

	if (!mddev->pers || !mddev->pers->sync_request)

		return -EINVAL;

	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))

		return;



	if (mddev_lock(mddev))

		return;



	/*

	 * Check again in case MD_RECOVERY_RUNNING is cleared before lock is

	 * held.

	 */

	if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {

		mddev_unlock(mddev);

		return;

	}



	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {

		if (cmd_match(page, "frozen"))

			set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);

		else

			clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);

		if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&

		    mddev_lock(mddev) == 0) {

	if (work_pending(&mddev->del_work))

		flush_workqueue(md_misc_wq);



	if (mddev->sync_thread) {

		set_bit(MD_RECOVERY_INTR, &mddev->recovery);

		md_reap_sync_thread(mddev);

	}



	mddev_unlock(mddev);

}

	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))



static void idle_sync_thread(struct mddev *mddev)

{

	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);

	stop_sync_thread(mddev);

}



static void frozen_sync_thread(struct mddev *mddev)

{

	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);

	stop_sync_thread(mddev);

}



static ssize_t

action_store(struct mddev *mddev, const char *page, size_t len)

{

	if (!mddev->pers || !mddev->pers->sync_request)

		return -EINVAL;





	if (cmd_match(page, "idle"))

		idle_sync_thread(mddev);

	else if (cmd_match(page, "frozen"))

		frozen_sync_thread(mddev);

	else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))

		return -EBUSY;

	else if (cmd_match(page, "resync"))

		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);