Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Lawrence , NeilBrown Subject: [ 45/99] md: Remove recent change which allows devices to skip recovery. Date: Fri, 2 Aug 2013 18:07:58 +0800 Message-Id: <20130802100232.361687043@linuxfoundation.org> In-Reply-To: <20130802100225.478715166@linuxfoundation.org> References: <20130802100225.478715166@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit 5024c298311f3b97c85cb034f9edaa333fdb9338 upstream. commit 7ceb17e87bde79d285a8b988cfed9eaeebe60b86 md: Allow devices to be re-added to a read-only array. allowed a bit more than just that. It also allows devices to be added to a read-write array and to end up skipping recovery. This patch removes the offending piece of code pending a rewrite for a subsequent release. More specifically: If the array has a bitmap, then the device will still need a bitmap based resync ('saved_raid_disk' is set under different conditions is a bitmap is present). If the array doesn't have a bitmap, then this is correct as long as nothing has been written to the array since the metadata was checked by ->validate_super. However there is no locking to ensure that there was no write. Bug was introduced in 3.10 and causes data corruption so patch is suitable for 3.10-stable. Reported-by: Joe Lawrence Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 14 -------------- 1 file changed, 14 deletions(-) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7697,20 +7697,6 @@ static int remove_and_add_spares(struct continue; rdev->recovery_offset = 0; - if (rdev->saved_raid_disk >= 0 && mddev->in_sync) { - spin_lock_irq(&mddev->write_lock); - if (mddev->in_sync) - /* OK, this device, which is in_sync, - * will definitely be noticed before - * the next write, so recovery isn't - * needed. - */ - rdev->recovery_offset = mddev->recovery_cp; - spin_unlock_irq(&mddev->write_lock); - } - if (mddev->ro && rdev->recovery_offset != MaxSector) - /* not safe to add this disk now */ - continue; if (mddev->pers-> hot_add_disk(mddev, rdev) == 0) { if (sysfs_link_rdev(mddev, rdev))