From: NeilBrown Date: Tue, 17 Oct 2017 05:18:36 +0000 (+1100) Subject: raid5: Set R5_Expanded on parity devices as well as data. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=24bc48af0aee2e144655b3b1d36a96def03480d0;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git raid5: Set R5_Expanded on parity devices as well as data. [ Upstream commit 235b6003fb28f0dd8e7ed8fbdb088bb548291766 ] When reshaping a fully degraded raid5/raid6 to a larger nubmer of devices, the new device(s) are not in-sync and so that can make the newly grown stripe appear to be "failed". To avoid this, we set the R5_Expanded flag to say "Even though this device is not fully in-sync, this block is safe so don't treat the device as failed for this stripe". This flag is set for data devices, not not for parity devices. Consequently, if you have a RAID6 with two devices that are partly recovered and a spare, and start a reshape to include the spare, then when the reshape gets past the point where the recovery was up to, it will think the stripes are failed and will get into an infinite loop, failing to make progress. So when contructing parity on an EXPAND_READY stripe, set R5_Expanded. Reported-by: Curt Signed-off-by: NeilBrown Signed-off-by: Shaohua Li Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index d55bf85b76ce..86ab6d14d782 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1681,8 +1681,11 @@ static void ops_complete_reconstruct(void *stripe_head_ref) struct r5dev *dev = &sh->dev[i]; if (dev->written || i == pd_idx || i == qd_idx) { - if (!discard && !test_bit(R5_SkipCopy, &dev->flags)) + if (!discard && !test_bit(R5_SkipCopy, &dev->flags)) { set_bit(R5_UPTODATE, &dev->flags); + if (test_bit(STRIPE_EXPAND_READY, &sh->state)) + set_bit(R5_Expanded, &dev->flags); + } if (fua) set_bit(R5_WantFUA, &dev->flags); if (sync)