Commit 7ebc0be7 authored by NeilBrown's avatar NeilBrown
Browse files

md: Be more careful about clearing flags bit in ->recovery 



Setting ->recovery to 0 is generally not a good idea as it could clear
bits that shouldn't be cleared.  In particular, MD_RECOVERY_FROZEN
should only be cleared on explicit request from user-space.

So when we need to clear things, just clear the bits that need
clearing.

As there are a few different places which reap a resync process - and
some do an incomplte job - factor out the code for doing the from
md_check_recovery and call that function instead of open coding part
of it.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Reported-by: default avatarJonathan Brassow <jbrassow@redhat.com>
parent defad61a

drivers/md/md.c

+49 −37
Original line number Diff line number Diff line
@@ -3746,6 +3746,8 @@ action_show(mddev_t *mddev, char *page) 
	return sprintf(page, "%s\n", type);

}



static void reap_sync_thread(mddev_t *mddev);



static ssize_t

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

{
@@ -3760,9 +3762,7 @@ action_store(mddev_t *mddev, const char *page, size_t len) 
	if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {

		if (mddev->sync_thread) {

			set_bit(MD_RECOVERY_INTR, &mddev->recovery);

			md_unregister_thread(mddev->sync_thread);

			mddev->sync_thread = NULL;

			mddev->recovery = 0;

			reap_sync_thread(mddev);

		}

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

		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
@@ -4709,8 +4709,7 @@ static void __md_stop_writes(mddev_t *mddev) 
	if (mddev->sync_thread) {

		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);

		set_bit(MD_RECOVERY_INTR, &mddev->recovery);

		md_unregister_thread(mddev->sync_thread);

		mddev->sync_thread = NULL;

		reap_sync_thread(mddev);

	}



	del_timer_sync(&mddev->safemode_timer);
@@ -7044,6 +7043,45 @@ static int remove_and_add_spares(mddev_t *mddev) 
	}

	return spares;

}



static void reap_sync_thread(mddev_t *mddev)

{

	mdk_rdev_t *rdev;



	/* resync has finished, collect result */

	md_unregister_thread(mddev->sync_thread);

	mddev->sync_thread = NULL;

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

	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {

		/* success...*/

		/* activate any spares */

		if (mddev->pers->spare_active(mddev))

			sysfs_notify(&mddev->kobj, NULL,

				     "degraded");

	}

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

	    mddev->pers->finish_reshape)

		mddev->pers->finish_reshape(mddev);

	md_update_sb(mddev, 1);



	/* if array is no-longer degraded, then any saved_raid_disk

	 * information must be scrapped

	 */

	if (!mddev->degraded)

		list_for_each_entry(rdev, &mddev->disks, same_set)

			rdev->saved_raid_disk = -1;



	clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);

	clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);

	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);

	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);

	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);

	/* flag recovery needed just to double check */

	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

	sysfs_notify_dirent_safe(mddev->sysfs_action);

	md_new_event(mddev);

}



/*

 * This routine is regularly called by all per-raid-array threads to

 * deal with generic issues like resync and super-block update.
@@ -7068,9 +7106,6 @@ static int remove_and_add_spares(mddev_t *mddev) 
 */

void md_check_recovery(mddev_t *mddev)

{

	mdk_rdev_t *rdev;





	if (mddev->bitmap)

		bitmap_daemon_work(mddev);
@@ -7138,34 +7173,7 @@ void md_check_recovery(mddev_t *mddev) 
			goto unlock;

		}

		if (mddev->sync_thread) {

			/* resync has finished, collect result */

			md_unregister_thread(mddev->sync_thread);

			mddev->sync_thread = NULL;

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

			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {

				/* success...*/

				/* activate any spares */

				if (mddev->pers->spare_active(mddev))

					sysfs_notify(&mddev->kobj, NULL,

						     "degraded");

			}

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

			    mddev->pers->finish_reshape)

				mddev->pers->finish_reshape(mddev);

			md_update_sb(mddev, 1);



			/* if array is no-longer degraded, then any saved_raid_disk

			 * information must be scrapped

			 */

			if (!mddev->degraded)

				list_for_each_entry(rdev, &mddev->disks, same_set)

					rdev->saved_raid_disk = -1;



			mddev->recovery = 0;

			/* flag recovery needed just to double check */

			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

			sysfs_notify_dirent_safe(mddev->sysfs_action);

			md_new_event(mddev);

			reap_sync_thread(mddev);

			goto unlock;

		}

		/* Set RUNNING before clearing NEEDED to avoid
@@ -7223,7 +7231,11 @@ void md_check_recovery(mddev_t *mddev) 
					" thread...\n", 

					mdname(mddev));

				/* leave the spares where they are, it shouldn't hurt */

				mddev->recovery = 0;

				clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);

				clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);

				clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);

				clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);

				clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);

			} else

				md_wakeup_thread(mddev->sync_thread);

			sysfs_notify_dirent_safe(mddev->sysfs_action);

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