When attempting to rebuild a softraid volume, use the actual data offset

from the volume metadata rather than the currently defined data offset.
This allows rebuilds to work correctly when the volume metadata has a
different data offset to that currently in use (for example, volumes
created prior to softraid gaining boot support).

Found the hard way by henning@

ok deraadt@

diff --git a/sys/dev/softraid.c b/sys/dev/softraid.c
index eea7261..f20c107 100644 (file)
--- a/sys/dev/softraid.c
+++ b/sys/dev/softraid.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: softraid.c,v 1.337 2014/07/20 18:10:15 deraadt Exp $ */
+/* $OpenBSD: softraid.c,v 1.338 2014/08/01 01:32:09 jsing Exp $ */
 /*
  * Copyright (c) 2007, 2008, 2009 Marco Peereboom <marco@peereboom.us>
  * Copyright (c) 2008 Chris Kuethe <ckuethe@openbsd.org>
@@ -3183,7 +3183,7 @@ sr_rebuild_init(struct sr_discipline *sd, dev_t dev, int hotspare)
 
        /* Is the partition large enough? */
        size = DL_SECTOBLK(&label, DL_GETPSIZE(&label.d_partitions[part])) -
-           SR_DATA_OFFSET;
+           sd->sd_meta->ssd_data_offset;
        if (size < csize) {
                sr_error(sc, "%s partition too small, at least %lld bytes "
                    "required", devname, (long long)(csize << DEV_BSHIFT));