--- loop.c.orig	Sun Feb  2 21:14:34 2003
+++ loop.c	Sun Feb  2 21:34:01 2003
@@ -79,6 +79,8 @@
 
 #include <asm/uaccess.h>
 
+#define LOOP_IV_SECTOR_BITS 9
+
 static int max_loop = 8;
 static struct loop_device *loop_dev;
 static struct gendisk **disks;
@@ -196,7 +198,7 @@
 	data = kmap(bvec->bv_page) + bvec->bv_offset;
 	len = bvec->bv_len;
 	while (len > 0) {
-		sector_t IV = index * (PAGE_CACHE_SIZE/bsize) + offset/bsize;
+		sector_t IV = (index << (PAGE_CACHE_SHIFT - LOOP_IV_SECTOR_BITS)) + (offset >> LOOP_IV_SECTOR_BITS);
 		int transfer_result;
 
 		size = PAGE_CACHE_SIZE - offset;
@@ -276,7 +278,7 @@
 	unsigned long count = desc->count;
 	struct lo_read_data *p = (struct lo_read_data*)desc->buf;
 	struct loop_device *lo = p->lo;
-	int IV = page->index * (PAGE_CACHE_SIZE/p->bsize) + offset/p->bsize;
+	int IV =  (page->index << (PAGE_CACHE_SHIFT - LOOP_IV_SECTOR_BITS)) + (offset >> LOOP_IV_SECTOR_BITS);
 
 	if (size > count)
 		size = count;
@@ -469,7 +471,7 @@
 bio_transfer(struct loop_device *lo, struct bio *to_bio,
 			      struct bio *from_bio)
 {
-	unsigned long IV = loop_get_iv(lo, from_bio->bi_sector);
+	unsigned long IV = from_bio->bi_sector + (lo->lo_offset >> LOOP_IV_SECTOR_BITS);
 	struct bio_vec *from_bvec, *to_bvec;
 	char *vto, *vfrom;
 	int ret = 0, i;
@@ -530,7 +532,7 @@
 	 * piggy old buffer on original, and submit for I/O
 	 */
 	new_bio = loop_get_buffer(lo, old_bio);
-	IV = loop_get_iv(lo, old_bio->bi_sector);
+	IV = old_bio->bi_sector + (lo->lo_offset >> LOOP_IV_SECTOR_BITS);
 	if (rw == WRITE) {
 		if (bio_transfer(lo, new_bio, old_bio))
 			goto err;