multipath-tools: kpartx: fix partition calculations of DASD partitions

 This patch fixes the offset and length calcuations for DASD partitions
 with either CMS (without explicit offset), the old linux disk layout or
 no partition information at all if the devices are using a blocksize bigger
 than 512B.
 In the cases mentioned above the offset was normalized (to the number of
 512B sectors) twice and the size reduced by the normalized offset and again
 by the double normalized offset later.
 This leads to kpartx defining the wrong limits in these cases.

 Signed-off-by: Stefan Bader <shbader@de.ibm.com>

 dasd.c |   28 ++++++++++++++++------------
 1 files changed, 16 insertions(+), 12 deletions(-)

diff -Nurp multipath-tools-0.4.5.59/kpartx/dasd.c multipath-tools-0.4.5.59-kpartx/kpartx/dasd.c
--- multipath-tools-0.4.5.59/kpartx/dasd.c	2006-12-07 12:52:21.000000000 +0100
+++ multipath-tools-0.4.5.59-kpartx/kpartx/dasd.c	2006-12-07 13:59:14.000000000 +0100
@@ -40,14 +40,20 @@
 #include "byteorder.h"
 #include "dasd.h"
 
+unsigned long sectors512(unsigned long sectors, int blocksize)
+{
+	return sectors * (blocksize >> 9);
+}
+
 /*
  */
 int 
 read_dasd_pt(int fd, struct slice all, struct slice *sp, int ns)
 {
 	int retval = -1;
-	int blocksize, offset, size;
+	int blocksize;
 	long disksize;
+	unsigned long offset, size;
 	dasd_information_t info;
 	struct hd_geometry geo;
 	char type[5] = {0,};
@@ -172,13 +178,13 @@ read_dasd_pt(int fd, struct slice all, s
 			/* disk is reserved minidisk */
 			blocksize = label[3];
 			offset = label[13];
-			size = (label[7] - 1)*(blocksize >> 9);
+			size   = sectors512(label[7] - 1, blocksize);
 		} else {
-			offset = (info.label_block + 1) * (blocksize >> 9);
-			size = disksize - offset;
+			offset = info.label_block + 1;
+			size   = disksize;
 		}
-		sp[0].start = offset * (blocksize >> 9);
-		sp[0].size = size - offset * (blocksize >> 9);
+		sp[0].start = sectors512(offset, blocksize);
+		sp[0].size  = size - sp[0].start;
 		retval = 1;
 	} else if ((strncmp(type, "VOL1", 4) == 0) &&
 		(!info.FBA_layout) && (!strcmp(info.type, "ECKD"))) {
@@ -214,8 +220,8 @@ read_dasd_pt(int fd, struct slice all, s
 		        offset = cchh2blk(&f1.DS1EXT1.llimit, &geo);
 			size  = cchh2blk(&f1.DS1EXT1.ulimit, &geo) - 
 				offset + geo.sectors;
-			sp[counter].start = offset * (blocksize >> 9);
-			sp[counter].size = size * (blocksize >> 9);
+			sp[counter].start = sectors512(offset, blocksize);
+			sp[counter].size  = sectors512(size, blocksize);
 			counter++;
 			blk++;
 		}
@@ -224,10 +230,8 @@ read_dasd_pt(int fd, struct slice all, s
 		/*
 		 * Old style LNX1 or unlabeled disk
 		 */
-		offset = (info.label_block + 1) * (blocksize >> 9);
-		size = disksize - offset;
-		sp[0].start = offset * (blocksize >> 9);
-		sp[0].size = size - offset * (blocksize >> 9);
+		sp[0].start = sectors512(info.label_block + 1, blocksize);
+		sp[0].size  = disksize - sp[0].start;
 		retval = 1;
 	}