Commit acb180b0 authored by NeilBrown's avatar NeilBrown
Browse files

md: improve usefulness and accuracy of sysfs file md/sync_completed. 



The sync_completed file reports how much of a resync (or recovery or
reshape) has been completed.
However due to the possibility of out-of-order completion of writes,
it is not certain to be accurate.

We have an internal value - mddev->curr_resync_completed - which is an
accurate value (though it might not always be quite so uptodate).

So:
 - make curr_resync_completed be uptodate a little more often,
   particularly when raid5 reshape updates status in the metadata
 - report curr_resync_completed in the sysfs file
 - allow poll/select to report all updates to md/sync_completed.

This makes sync_completed completed usable by any external metadata
handler that wants to record this status information in its metadata.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 6d56e278

drivers/md/bitmap.c

+1 −0
Original line number Diff line number Diff line
@@ -1479,6 +1479,7 @@ void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector) 
		s += blocks;

	}

	bitmap->last_end_sync = jiffies;

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

}



static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)

drivers/md/md.c

+22 −12
Original line number Diff line number Diff line
@@ -2017,6 +2017,8 @@ repeat: 
	clear_bit(MD_CHANGE_PENDING, &mddev->flags);

	spin_unlock_irq(&mddev->write_lock);

	wake_up(&mddev->sb_wait);

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

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



}
@@ -3486,12 +3488,15 @@ sync_completed_show(mddev_t *mddev, char *page) 
{

	unsigned long max_sectors, resync;



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

		return sprintf(page, "none\n");



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

		max_sectors = mddev->resync_max_sectors;

	else

		max_sectors = mddev->dev_sectors;



	resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));

	resync = mddev->curr_resync_completed;

	return sprintf(page, "%lu / %lu\n", resync, max_sectors);

}
@@ -6338,18 +6343,12 @@ void md_do_sync(mddev_t *mddev) 
		sector_t sectors;



		skipped = 0;

		if (j >= mddev->resync_max) {

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

			wait_event(mddev->recovery_wait,

				   mddev->resync_max > j

				   || kthread_should_stop());

		}

		if (kthread_should_stop())

			goto interrupted;



		if (mddev->curr_resync > mddev->curr_resync_completed &&

		if ((mddev->curr_resync > mddev->curr_resync_completed &&

		     (mddev->curr_resync - mddev->curr_resync_completed)

		    > (max_sectors >> 4)) {

		    > (max_sectors >> 4)) ||

		    j >= mddev->resync_max

			) {

			/* time to update curr_resync_completed */

			blk_unplug(mddev->queue);

			wait_event(mddev->recovery_wait,
@@ -6357,7 +6356,17 @@ void md_do_sync(mddev_t *mddev) 
			mddev->curr_resync_completed =

				mddev->curr_resync;

			set_bit(MD_CHANGE_CLEAN, &mddev->flags);

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

		}



		if (j >= mddev->resync_max)

			wait_event(mddev->recovery_wait,

				   mddev->resync_max > j

				   || kthread_should_stop());



		if (kthread_should_stop())

			goto interrupted;



		sectors = mddev->pers->sync_request(mddev, j, &skipped,

						  currspeed < speed_min(mddev));

		if (sectors == 0) {
@@ -6465,6 +6474,7 @@ void md_do_sync(mddev_t *mddev) 


 skip:

	mddev->curr_resync = 0;

	mddev->curr_resync_completed = 0;

	mddev->resync_min = 0;

	mddev->resync_max = MaxSector;

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

drivers/md/raid5.c

+4 −0
Original line number Diff line number Diff line
@@ -3845,6 +3845,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped 
		wait_event(conf->wait_for_overlap,

			   atomic_read(&conf->reshape_stripes)==0);

		mddev->reshape_position = conf->reshape_progress;

		mddev->curr_resync_completed = mddev->curr_resync;

		conf->reshape_checkpoint = jiffies;

		set_bit(MD_CHANGE_DEVS, &mddev->flags);

		md_wakeup_thread(mddev->thread);
@@ -3854,6 +3855,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped 
		conf->reshape_safe = mddev->reshape_position;

		spin_unlock_irq(&conf->device_lock);

		wake_up(&conf->wait_for_overlap);

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

	}



	if (mddev->delta_disks < 0) {
@@ -3943,6 +3945,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped 
		wait_event(conf->wait_for_overlap,

			   atomic_read(&conf->reshape_stripes) == 0);

		mddev->reshape_position = conf->reshape_progress;

		mddev->curr_resync_completed = mddev->curr_resync;

		conf->reshape_checkpoint = jiffies;

		set_bit(MD_CHANGE_DEVS, &mddev->flags);

		md_wakeup_thread(mddev->thread);
@@ -3953,6 +3956,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped 
		conf->reshape_safe = mddev->reshape_position;

		spin_unlock_irq(&conf->device_lock);

		wake_up(&conf->wait_for_overlap);

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

	}

	return reshape_sectors;

}

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