From ba8805b97320416e7c5bb8f55d2bd06d5c319e7d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 14 Nov 2013 15:16:15 +1100 Subject: [PATCH] md/raid5.c: add proper locking to error path of raid5_start_reshape. 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 --- drivers/md/raid5.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index f013d36..4bbcb7e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -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; } -- 2.7.4