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Commit db0505d3 authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li
Browse files

md: be cautious about using ->curr_resync_completed for ->recovery_offset 



The ->recovery_offset shows how much of a non-InSync device is actually
in sync - how much has been recoveryed.

When performing a recovery, ->curr_resync and ->curr_resync_completed
follow the device address being recovered and so can be used to update
->recovery_offset.

When performing a reshape, ->curr_resync* might follow the device
addresses (raid5) or might follow array addresses (raid10), so cannot
in general be used to set ->recovery_offset.  When reshaping backwards,
->curre_resync* measures from the *end* of the array-or-device, so is
particularly unhelpful.

So change the common code in md.c to only use ->curr_resync_complete
for the simple recovery case, and add code to raid5.c to update
->recovery_offset during a forwards reshape.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 39b4954c

drivers/md/md.c

+22 −11
Original line number Diff line number Diff line
@@ -2454,10 +2454,18 @@ void md_update_sb(struct mddev *mddev, int force_change) 
		}

	}



	/* First make sure individual recovery_offsets are correct */

	/*

	 * First make sure individual recovery_offsets are correct

	 * curr_resync_completed can only be used during recovery.

	 * During reshape/resync it might use array-addresses rather

	 * that device addresses.

	 */

	rdev_for_each(rdev, mddev) {

		if (rdev->raid_disk >= 0 &&

		    mddev->delta_disks >= 0 &&

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

		    test_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&

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

		    !test_bit(Journal, &rdev->flags) &&

		    !test_bit(In_sync, &rdev->flags) &&

		    mddev->curr_resync_completed > rdev->recovery_offset)
@@ -8491,6 +8499,8 @@ void md_do_sync(struct md_thread *thread) 
		} else {

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

				mddev->curr_resync = MaxSector;

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

			    test_bit(MD_RECOVERY_RECOVER, &mddev->recovery)) {

				rcu_read_lock();

				rdev_for_each_rcu(rdev, mddev)

					if (rdev->raid_disk >= 0 &&
@@ -8503,6 +8513,7 @@ void md_do_sync(struct md_thread *thread) 
				rcu_read_unlock();

			}

		}

	}

 skip:

	/* set CHANGE_PENDING here since maybe another update is needed,

	 * so other nodes are informed. It should be harmless for normal

drivers/md/raid5.c

+24 −0
Original line number Diff line number Diff line
@@ -5738,6 +5738,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk 
	 */

	struct r5conf *conf = mddev->private;

	struct stripe_head *sh;

	struct md_rdev *rdev;

	sector_t first_sector, last_sector;

	int raid_disks = conf->previous_raid_disks;

	int data_disks = raid_disks - conf->max_degraded;
@@ -5860,6 +5861,15 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk 
			return 0;

		mddev->reshape_position = conf->reshape_progress;

		mddev->curr_resync_completed = sector_nr;

		if (!mddev->reshape_backwards)

			/* Can update recovery_offset */

			rdev_for_each(rdev, mddev)

				if (rdev->raid_disk >= 0 &&

				    !test_bit(Journal, &rdev->flags) &&

				    !test_bit(In_sync, &rdev->flags) &&

				    rdev->recovery_offset < sector_nr)

					rdev->recovery_offset = sector_nr;



		conf->reshape_checkpoint = jiffies;

		set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);

		md_wakeup_thread(mddev->thread);
@@ -5958,6 +5968,14 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk 
			goto ret;

		mddev->reshape_position = conf->reshape_progress;

		mddev->curr_resync_completed = sector_nr;

		if (!mddev->reshape_backwards)

			/* Can update recovery_offset */

			rdev_for_each(rdev, mddev)

				if (rdev->raid_disk >= 0 &&

				    !test_bit(Journal, &rdev->flags) &&

				    !test_bit(In_sync, &rdev->flags) &&

				    rdev->recovery_offset < sector_nr)

					rdev->recovery_offset = sector_nr;

		conf->reshape_checkpoint = jiffies;

		set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);

		md_wakeup_thread(mddev->thread);
@@ -7945,6 +7963,7 @@ static void end_reshape(struct r5conf *conf) 
{



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

		struct md_rdev *rdev;



		spin_lock_irq(&conf->device_lock);

		conf->previous_raid_disks = conf->raid_disks;
@@ -7952,6 +7971,11 @@ static void end_reshape(struct r5conf *conf) 
		smp_wmb();

		conf->reshape_progress = MaxSector;

		conf->mddev->reshape_position = MaxSector;

		rdev_for_each(rdev, conf->mddev)

			if (rdev->raid_disk >= 0 &&

			    !test_bit(Journal, &rdev->flags) &&

			    !test_bit(In_sync, &rdev->flags))

				rdev->recovery_offset = MaxSector;

		spin_unlock_irq(&conf->device_lock);

		wake_up(&conf->wait_for_overlap);