Fix a braino: the partition size in the PMBR is in sectors, not bytes

and 'mediasz' is in bytes. As it so happens, we define 'last' as the
sector number of the last sector on the medium which also is the size
of the PMBR partition. Therefore, use 'last' instead of 'mediasz'.

Submitted by: Dan Markarian <markarian at apple dot com>

2 files changed, 8 insertions, 8 deletions

diff --git a/sbin/gpt/create.c b/sbin/gpt/create.c
index 47c47fd..6591b93 100644
--- a/sbin/gpt/create.c
+++ b/sbin/gpt/create.c
@@ -63,6 +63,8 @@ create(int fd)
 	struct gpt_ent *ent;
 	unsigned int i;
 
+	last = mediasz / secsz - 1LL;
+
 	if (map_find(MAP_TYPE_PRI_GPT_HDR) != NULL ||
 	    map_find(MAP_TYPE_SEC_GPT_HDR) != NULL) {
 		warnx("%s: error: device already contains a GPT", device_name);
@@ -92,12 +94,12 @@ create(int fd)
 		mbr->mbr_part[0].part_esect = 0xff;
 		mbr->mbr_part[0].part_ecyl = 0xff;
 		mbr->mbr_part[0].part_start_lo = htole16(1);
-		if (mediasz > 0xffffffff) {
+		if (last > 0xffffffff) {
 			mbr->mbr_part[0].part_size_lo = htole16(0xffff);
 			mbr->mbr_part[0].part_size_hi = htole16(0xffff);
 		} else {
-			mbr->mbr_part[0].part_size_lo = htole16(mediasz);
-			mbr->mbr_part[0].part_size_hi = htole16(mediasz >> 16);
+			mbr->mbr_part[0].part_size_lo = htole16(last);
+			mbr->mbr_part[0].part_size_hi = htole16(last >> 16);
 		}
 		map = map_add(0LL, 1LL, MAP_TYPE_PMBR, mbr);
 		gpt_write(fd, map);
@@ -118,8 +120,6 @@ create(int fd)
 		blocks++;		/* Don't forget the header itself */
 	}
 
-	last = mediasz / secsz - 1LL;
-
 	/* Never cross the median of the device. */
 	if ((blocks + 1LL) > ((last + 1LL) >> 1))
 		blocks = ((last + 1LL) >> 1) - 1LL;
diff --git a/sbin/gpt/migrate.c b/sbin/gpt/migrate.c
index d9f4074..d0f1485 100644
--- a/sbin/gpt/migrate.c
+++ b/sbin/gpt/migrate.c
@@ -313,12 +313,12 @@ migrate(int fd)
 	mbr->mbr_part[0].part_esect = 0xff;
 	mbr->mbr_part[0].part_ecyl = 0xff;
 	mbr->mbr_part[0].part_start_lo = htole16(1);
-	if (mediasz > 0xffffffff) {
+	if (last > 0xffffffff) {
 		mbr->mbr_part[0].part_size_lo = htole16(0xffff);
 		mbr->mbr_part[0].part_size_hi = htole16(0xffff);
 	} else {
-		mbr->mbr_part[0].part_size_lo = htole16(mediasz);
-		mbr->mbr_part[0].part_size_hi = htole16(mediasz >> 16);
+		mbr->mbr_part[0].part_size_lo = htole16(last);
+		mbr->mbr_part[0].part_size_hi = htole16(last >> 16);
 	}
 	gpt_write(fd, map);
 }