From a64685399181780998281fe07309a94b25dd24c3 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 21 Feb 2013 14:33:17 +1100 Subject: md: fix two bugs when attempting to resize RAID0 array. You cannot resize a RAID0 array (in terms of making the devices bigger), but the code doesn't entirely stop you. So: disable setting of the available size on each device for RAID0 and Linear devices. This must not change as doing so can change the effective layout of data. Make sure that the size that raid0_size() reports is accurate, but rounding devices sizes to chunk sizes. As the device sizes cannot change now, this isn't so important, but it is best to be safe. Without this change: mdadm --grow /dev/md0 -z max mdadm --grow /dev/md0 -Z max then read to the end of the array can cause a BUG in a RAID0 array. These bugs have been present ever since it became possible to resize any device, which is a long time. So the fix is suitable for any -stable kerenl. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown --- drivers/md/md.c | 3 +++ drivers/md/raid0.c | 3 ++- 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/md') diff --git a/drivers/md/md.c b/drivers/md/md.c index 1e634a68541e..f363135144f6 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2998,6 +2998,9 @@ rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len) } else if (!sectors) sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) - rdev->data_offset; + if (!my_mddev->pers->resize) + /* Cannot change size for RAID0 or Linear etc */ + return -EINVAL; } if (sectors < my_mddev->dev_sectors) return -EINVAL; /* component must fit device */ diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 24b359717a7e..15c8d3505450 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -411,7 +411,8 @@ static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks "%s does not support generic reshape\n", __func__); rdev_for_each(rdev, mddev) - array_sectors += rdev->sectors; + array_sectors += (rdev->sectors & + ~(sector_t)(mddev->chunk_sectors-1)); return array_sectors; } -- cgit v1.2.3