[PATCH] mtdpart: Avoid divide-by-zero on out-of-reach path

[Atsushi Nemoto]

On "partition is out of reach" path, slave->mtd.erasesize will be zero
and it leads division by zero.  This patch makes calculation of the
slave erasesize more robust.

This patch also contains some cleanups.  Do not shadow symbol 'i',
fold long lines, etc.

Signed-off-by: Atsushi Nemoto <anemo at mba.ocn.ne.jp>
---
 drivers/mtd/mtdpart.c |   25 +++++++++++++++----------
 1 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index c66902d..9a0bbae 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -445,17 +445,22 @@ int add_mtd_partitions(struct mtd_info *master,
 		}
 		if (master->numeraseregions>1) {
 			/* Deal with variable erase size stuff */
-			int i;
-			struct mtd_erase_region_info *regions = master->eraseregions;
-
-			/* Find the first erase regions which is part of this partition. */
-			for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
+			int j, num = master->numeraseregions;
+			struct mtd_erase_region_info *r = master->eraseregions;
+			/*
+			 * Find the first erase region which is part
+			 * of this partition.
+			 */
+			for (j = 0; j < num && slave->offset >= r[j].offset;
+				j++)
 				;
-
-			for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
-				if (slave->mtd.erasesize < regions[i].erasesize) {
-					slave->mtd.erasesize = regions[i].erasesize;
-				}
+			j--;
+			slave->mtd.erasesize = r[j].erasesize;
+			for (; j < num &&
+				slave->offset + slave->mtd.size > r[j].offset;
+				j++) {
+				if (slave->mtd.erasesize < r[j].erasesize)
+					slave->mtd.erasesize = r[j].erasesize;
 			}
 		} else {
 			/* Single erase size */