From fc9739c6d626ee79a148ec367d143b0601299a9d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Mar 2009 14:57:20 +1100 Subject: [PATCH] md: add takeover support for converting raid6 back into raid5 If a raid6 is still in the layout that comes from converting raid5 into a raid6. this will allow us to convert it back again. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 95953273c4d9..70b50af2bcd7 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4912,6 +4912,39 @@ static void *raid5_takeover_raid1(mddev_t *mddev) return setup_conf(mddev); } +static void *raid5_takeover_raid6(mddev_t *mddev) +{ + int new_layout; + + switch (mddev->layout) { + case ALGORITHM_LEFT_ASYMMETRIC_6: + new_layout = ALGORITHM_LEFT_ASYMMETRIC; + break; + case ALGORITHM_RIGHT_ASYMMETRIC_6: + new_layout = ALGORITHM_RIGHT_ASYMMETRIC; + break; + case ALGORITHM_LEFT_SYMMETRIC_6: + new_layout = ALGORITHM_LEFT_SYMMETRIC; + break; + case ALGORITHM_RIGHT_SYMMETRIC_6: + new_layout = ALGORITHM_RIGHT_SYMMETRIC; + break; + case ALGORITHM_PARITY_0_6: + new_layout = ALGORITHM_PARITY_0; + break; + case ALGORITHM_PARITY_N: + new_layout = ALGORITHM_PARITY_N; + break; + default: + return ERR_PTR(-EINVAL); + } + mddev->new_level = 5; + mddev->new_layout = new_layout; + mddev->delta_disks = -1; + mddev->raid_disks -= 1; + return setup_conf(mddev); +} + static int raid5_reconfig(mddev_t *mddev, int new_layout, int new_chunk) { @@ -4972,6 +5005,8 @@ static void *raid5_takeover(mddev_t *mddev) mddev->new_level = 5; return setup_conf(mddev); } + if (mddev->level == 6) + return raid5_takeover_raid6(mddev); return ERR_PTR(-EINVAL); } -- 2.20.1