Commit 72a23c21 authored by Neil Brown's avatar Neil Brown
Browse files

Make sure all changes to md/sync_action are notified. 



When the 'resync' thread starts or stops, when we explicitly
set sync_action, or when we determine that there is definitely nothing
to do, we notify sync_action.

To stop "sync_action" from occasionally showing the wrong value,
we introduce a new flags - MD_RECOVERY_RECOVER - to say that a
recovery is probably needed or happening, and we make sure
that we set MD_RECOVERY_RUNNING before clearing MD_RECOVERY_NEEDED.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
parent 0fd62b86

Documentation/md.txt

+6 −0
Original line number Diff line number Diff line
@@ -386,6 +386,12 @@ also have 
	'check' and 'repair' will start the appropriate process

           providing the current state is 'idle'.



      This file responds to select/poll.  Any important change in the value

      triggers a poll event.  Sometimes the value will briefly be

      "recover" if a recovery seems to be needed, but cannot be

      achieved. In that case, the transition to "recover" isn't

      notified, but the transition away is.



   mismatch_count

      When performing 'check' and 'repair', and possibly when

      performing 'resync', md will count the number of errors that are

drivers/md/md.c

+28 −6
Original line number Diff line number Diff line
@@ -169,7 +169,6 @@ void md_new_event(mddev_t *mddev) 
{

	atomic_inc(&md_event_count);

	wake_up(&md_event_waiters);

	sysfs_notify(&mddev->kobj, NULL, "sync_action");

}

EXPORT_SYMBOL_GPL(md_new_event);
@@ -2936,7 +2935,7 @@ action_show(mddev_t *mddev, char *page) 
				type = "check";

			else

				type = "repair";

		} else

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

			type = "recover";

	}

	return sprintf(page, "%s\n", type);
@@ -2958,9 +2957,12 @@ action_store(mddev_t *mddev, const char *page, size_t len) 
	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||

		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))

		return -EBUSY;

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

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

		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

	else if (cmd_match(page, "recover")) {

		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);

		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

	else if (cmd_match(page, "reshape")) {

	} else if (cmd_match(page, "reshape")) {

		int err;

		if (mddev->pers->start_reshape == NULL)

			return -EINVAL;
@@ -2977,6 +2979,7 @@ action_store(mddev_t *mddev, const char *page, size_t len) 
	}

	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

	md_wakeup_thread(mddev->thread);

	sysfs_notify(&mddev->kobj, NULL, "sync_action");

	return len;

}
@@ -3682,6 +3685,7 @@ static int do_md_run(mddev_t * mddev) 
	mddev->changed = 1;

	md_new_event(mddev);

	sysfs_notify(&mddev->kobj, NULL, "array_state");

	sysfs_notify(&mddev->kobj, NULL, "sync_action");

	kobject_uevent(&mddev->gendisk->dev.kobj, KOBJ_CHANGE);

	return 0;

}
@@ -4252,6 +4256,8 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info) 
			export_rdev(rdev);



		md_update_sb(mddev, 1);

		if (mddev->degraded)

			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);

		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

		md_wakeup_thread(mddev->thread);

		return err;
@@ -5105,6 +5111,8 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev) 
	if (!mddev->pers->error_handler)

		return;

	mddev->pers->error_handler(mddev,rdev);

	if (mddev->degraded)

		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);

	set_bit(MD_RECOVERY_INTR, &mddev->recovery);

	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

	md_wakeup_thread(mddev->thread);
@@ -6055,13 +6063,18 @@ void md_check_recovery(mddev_t *mddev) 
			mddev->recovery = 0;

			/* flag recovery needed just to double check */

			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

			sysfs_notify(&mddev->kobj, NULL, "sync_action");

			md_new_event(mddev);

			goto unlock;

		}

		/* Set RUNNING before clearing NEEDED to avoid

		 * any transients in the value of "sync_action".

		 */

		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);

		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

		/* Clear some bits that don't mean anything, but

		 * might be left set

		 */

		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);

		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
@@ -6079,17 +6092,19 @@ void md_check_recovery(mddev_t *mddev) 
				/* Cannot proceed */

				goto unlock;

			set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);

			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);

		} else if ((spares = remove_and_add_spares(mddev))) {

			clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);

			clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);

			set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);

		} else if (mddev->recovery_cp < MaxSector) {

			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);

			clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);

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

			/* nothing to be done ... */

			goto unlock;



		if (mddev->pers->sync_request) {

			set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);

			if (spares && mddev->bitmap && ! mddev->bitmap->file) {

				/* We are adding a device or devices to an array

				 * which has the bitmap stored on all devices.
@@ -6108,9 +6123,16 @@ void md_check_recovery(mddev_t *mddev) 
				mddev->recovery = 0;

			} else

				md_wakeup_thread(mddev->sync_thread);

			sysfs_notify(&mddev->kobj, NULL, "sync_action");

			md_new_event(mddev);

		}

	unlock:

		if (!mddev->sync_thread) {

			clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);

			if (test_and_clear_bit(MD_RECOVERY_RECOVER,

					       &mddev->recovery))

				sysfs_notify(&mddev->kobj, NULL, "sync_action");

		}

		mddev_unlock(mddev);

	}

}

include/linux/raid/md_k.h

+2 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ struct mddev_s 
	 * NEEDED:   we might need to start a resync/recover

	 * RUNNING:  a thread is running, or about to be started

	 * SYNC:     actually doing a resync, not a recovery

	 * RECOVER:  doing recovery, or need to try it.

	 * INTR:     resync needs to be aborted for some reason

	 * DONE:     thread is done and is waiting to be reaped

	 * REQUEST:  user-space has requested a sync (used with SYNC)
@@ -198,6 +199,7 @@ struct mddev_s 
	 */

#define	MD_RECOVERY_RUNNING	0

#define	MD_RECOVERY_SYNC	1

#define	MD_RECOVERY_RECOVER	2

#define	MD_RECOVERY_INTR	3

#define	MD_RECOVERY_DONE	4

#define	MD_RECOVERY_NEEDED	5

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