mtd: nftl: fix offset alignments

Arithmetic conversion in the mask computation makes the upper word
of the second argument passed down to mtd->read_oob(), be always 0
(assuming 'offs' being a 64-bit signed long long type, and
'mtd->writesize' being a 32-bit unsigned int type).

This patch applies over the other one adding masking in nftl_write,
"nftl: write support is broken".
Signed-off-by: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: Scott James Remnant <scott@canonical.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nftlcore.c

@@ -135,16 +135,17 @@ static void nftl_remove_dev(struct mtd_blktrans_dev *dev)
 int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
 		  size_t *retlen, uint8_t *buf)
 {
+	loff_t mask = mtd->writesize - 1;
 	struct mtd_oob_ops ops;
 	int res;
 
 	ops.mode = MTD_OOB_PLACE;
-	ops.ooboffs = offs & (mtd->writesize - 1);
+	ops.ooboffs = offs & mask;
 	ops.ooblen = len;
 	ops.oobbuf = buf;
 	ops.datbuf = NULL;
 
-	res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+	res = mtd->read_oob(mtd, offs & ~mask, &ops);
 	*retlen = ops.oobretlen;
 	return res;
 }
@@ -155,16 +156,17 @@ int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
 int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
 		   size_t *retlen, uint8_t *buf)
 {
+	loff_t mask = mtd->writesize - 1;
 	struct mtd_oob_ops ops;
 	int res;
 
 	ops.mode = MTD_OOB_PLACE;
-	ops.ooboffs = offs & (mtd->writesize - 1);
+	ops.ooboffs = offs & mask;
 	ops.ooblen = len;
 	ops.oobbuf = buf;
 	ops.datbuf = NULL;
 
-	res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+	res = mtd->write_oob(mtd, offs & ~mask, &ops);
 	*retlen = ops.oobretlen;
 	return res;
 }
@@ -177,17 +179,18 @@ int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
 static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
 		      size_t *retlen, uint8_t *buf, uint8_t *oob)
 {
+	loff_t mask = mtd->writesize - 1;
 	struct mtd_oob_ops ops;
 	int res;
 
 	ops.mode = MTD_OOB_PLACE;
-	ops.ooboffs = offs & (mtd->writesize - 1);
+	ops.ooboffs = offs & mask;
 	ops.ooblen = mtd->oobsize;
 	ops.oobbuf = oob;
 	ops.datbuf = buf;
 	ops.len = len;
 
-	res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+	res = mtd->write_oob(mtd, offs & ~mask, &ops);
 	*retlen = ops.retlen;
 	return res;
 }