On Thu, 22 Mar 2012 17:15:53 +0100 Jes.Sorensen@xxxxxxxxxx wrote: > From: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> > > raid1 arrays do not have the notion of chunk size. Set the existing > chunk size of the new raid0 to the same as the proposed new chunk size > to avoid a divide by zero OOPS when aligning the size of the new array > to that of the chunk size. This oops happens in create_strip_zones at sector_div(sectors, mddev->chunk_sectors); correct? > > Signed-off-by: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> > --- > drivers/md/raid0.c | 8 ++++++++ > 1 files changed, 8 insertions(+), 0 deletions(-) > > diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c > index 6f31f55..dff8d6b 100644 > --- a/drivers/md/raid0.c > +++ b/drivers/md/raid0.c > @@ -639,6 +639,14 @@ static void *raid0_takeover_raid1(struct mddev *mddev) > mddev->new_level = 0; > mddev->new_layout = 0; > mddev->new_chunk_sectors = 128; /* by default set chunk size to 64k */ > + mddev->chunk_sectors = 128; /* > + * a raid1 one doesn't have the > + * notion of chunk size, so set > + * existing chunk_sector to match the > + * new size to avoid divide by zero > + * when aligning the size of the new > + * raid0 to the existing chunk size. > + */ But what if the RAID1 is not a multiple of 64K ? Then you will lose data. We probably want the same thing we have in RAID5: 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) < STRIPE_SIZE) /* array size does not allow a suitable chunk size */ return ERR_PTR(-EINVAL); ?? Do you want to make a patch, or shall I? Ofcouse, RAID0 have have non-power-of-2 chunk sizes, so we could just hunt for a small factor... probably not worth it though. Thanks, NeilBrown
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