I could swear we had the sizes right but I'll have another look at this.
What raid type did you test this with?
On Sun, Dec 19, 2010 at 02:17:46PM +0100, Andreas Bartelt wrote:
> Hello,
>
> I've noticed that the size of softraid(4) disks is one sector too large.
>
> In the following description, the native disk is sd4c (which is of type
> RAID), and the corresponding virtual softraid(4) disk will be sd5. I
> will assume that sd5 is of discipline CRYPTO, but the problem should be
> the same for all disciplines.
>
> The size for sd5 gets eventually stored in struct sr_metadata as
> sd_meta->ssdi.ssd_size in function sr_crypto_create
> (dev/softraid_crypto.c). Its value gets initially calculated in function
> sr_meta_native_probe (dev/softraid.c):
> size = DL_GETPSIZE(&label.d_partitions[part]) - SR_DATA_OFFSET;
> where SR_DATA_OFFSET = 528
>
> If the size (as shown via disklabel(8)) of the underlying disk sd4c is
> 'n', the variable 'size' will be calculated as 'n - 528'. However,
> according to disklabel(8), the resulting softraid(4) disk sd5c will be
> of size 'n - 528 + 1'. I think this is because function scsi_size in
> scsi/scsi_base.c returns 'max_addr + 1' where max_addr corresponds to
> sd_meta->ssdi.ssd_size.
>
> For example, newfs(8) on /dev/rsd5c tries to write to the last sector of
> sd5 (first wtfs call in mkfs.c) which is one sector beyond the native
> disk size of sd4. This gives an error if label sd4c was used as the
> native device. It results in a kernel panic in case another label of sd4
> was used as the underlying native device (i.e., sd4a).
>
> The attached diff fixes the problem for all newly created softraid volumes.
>
> TODO: fixing the problem for existing softraid(4) volumes would require
> to update sd_meta->ssdi.ssd_size to the correct size (and probably some
> other metadata for consistency).
>
> Best regards
> Andreas
> Index: softraid.c
> ===================================================================
> RCS file: /usr/cvsync/cvs/src/sys/dev/softraid.c,v
> retrieving revision 1.216
> diff -u -r1.216 softraid.c
> --- softraid.c 6 Nov 2010 23:01:56 -0000 1.216
> +++ softraid.c 19 Dec 2010 13:01:14 -0000
> @@ -1386,7 +1386,7 @@
> goto unwind;
> }
>
> - size = DL_GETPSIZE(&label.d_partitions[part]) - SR_DATA_OFFSET;
> + size = DL_GETPSIZE(&label.d_partitions[part]) - SR_DATA_OFFSET - 1;
> if (size <= 0) {
> DNPRINTF(SR_D_META, "%s: %s partition too small\n", DEVNAME(sc),
> devname);
