md/raid5.c: add proper locking to error path of raid5_start_reshape. (ba8805b9) · Commits · 戴 / test

If raid5_start_reshape errors out, we need to reset all the fields that were updated (not just some), and need to use the seq_counter to ensure make_request() doesn't use an inconsitent state. Signed-off-by:

NeilBrown <neilb@suse.de>

drivers/md/raid5.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -6384,12 +6384,18 @@ static int raid5_start_reshape(struct mddev *mddev)
		if (!mddev->sync_thread) {
		mddev->recovery = 0;
		spin_lock_irq(&conf->device_lock);
		write_seqcount_begin(&conf->gen_lock);
		mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
		mddev->new_chunk_sectors =
		conf->chunk_sectors = conf->prev_chunk_sectors;
		mddev->new_layout = conf->algorithm = conf->prev_algo;
		rdev_for_each(rdev, mddev)
		rdev->new_data_offset = rdev->data_offset;
		smp_wmb();
		conf->generation --;
		conf->reshape_progress = MaxSector;
		mddev->reshape_position = MaxSector;
		write_seqcount_end(&conf->gen_lock);
		spin_unlock_irq(&conf->device_lock);
		return -EAGAIN;
		}

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