From: Jes Sorensen Date: Sun, 1 Apr 2012 13:48:38 +0000 (+1000) Subject: md: Avoid OOPS when reshaping raid1 to raid0 X-Git-Tag: v3.4-rc2~27^2~3 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=24b961f811a3e790a9b93604d2594bfb6cce4fa4;p=pandora-kernel.git md: Avoid OOPS when reshaping raid1 to raid0 raid1 arrays do not have the notion of chunk size. Calculate the largest chunk sector size we can use to avoid a divide by zero OOPS when aligning the size of the new array to the chunk size. Signed-off-by: Jes Sorensen Signed-off-by: NeilBrown --- diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index c9809453a346..de63a1fc3737 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -632,6 +632,7 @@ static void *raid0_takeover_raid10(struct mddev *mddev) static void *raid0_takeover_raid1(struct mddev *mddev) { struct r0conf *priv_conf; + int chunksect; /* Check layout: * - (N - 1) mirror drives must be already faulty @@ -642,10 +643,25 @@ static void *raid0_takeover_raid1(struct mddev *mddev) return ERR_PTR(-EINVAL); } + /* + * a raid1 doesn't have the notion of chunk size, so + * figure out the largest suitable size we can use. + */ + chunksect = 64 * 2; /* 64K by default */ + + /* The array must be an exact multiple of chunksize */ + while (chunksect && (mddev->array_sectors & (chunksect - 1))) + chunksect >>= 1; + + if ((chunksect << 9) < PAGE_SIZE) + /* array size does not allow a suitable chunk size */ + return ERR_PTR(-EINVAL); + /* Set new parameters */ mddev->new_level = 0; mddev->new_layout = 0; - mddev->new_chunk_sectors = 128; /* by default set chunk size to 64k */ + mddev->new_chunk_sectors = chunksect; + mddev->chunk_sectors = chunksect; mddev->delta_disks = 1 - mddev->raid_disks; mddev->raid_disks = 1; /* make sure it will be not marked as dirty */