On Tue, Oct 21 2014 at 8:57am -0400, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > On Tue, Oct 21, 2014 at 08:48:26AM -0400, Mike Snitzer wrote: > > > - memset(sb + sizeof(*sb), 0, rdev->sb_size - sizeof(*sb)); > > > + memset(sb + 1, 0, rdev->sb_size - sizeof(*sb)); > > > > > > sb->magic = cpu_to_le32(DM_RAID_MAGIC); > > > sb->features = cpu_to_le32(0); /* No features yet */ > > > > Not following... sizeof(*sb) != sizeof(sb). So I'm not seeing a > > problem. > > > > Nor am I seeing how you think sb + 1 is equivalent to what Heinz > > intended (zero the memory following the sizeof(struct dm_raid_superblock)). > > It's pointer math. Yes, I see that now.. > sizeof(*sb) is 512. > > "sb + sizeof(*sb)" is the same as (void *)sb + 512 * 512. > "sb + 1" is the same as (void *)sb + 512. Actually, Heinz removed the 452 bytes of padding from struct dm_raid_superblock, so it is more like: sizeof(*sb) == sizeof(struct dm_raid_super_block) == 60 "sb + sizeof(*sb)" is the same as (void *)sb + 60 * 60 "sb + 1" is the same as (void *)sb + 60. But regardless, your broader point on the math stands. I'll get this fixed up, thanks! Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel