pNFS: Fix disk addr range check in block/scsi layout

At the end of the isect translation, disc_addr represents the physical
disk offset. Thus, end calculated from disk_addr is also a physical disk
offset. Therefore, range checking should be done using map->disk_offset,
not map->start.

Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250702133226.212537-1-sergeybashirov@gmail.com
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Author: sbashiro

fs/nfs/blocklayout/blocklayout.c

@@ -149,8 +149,8 @@ do_add_page_to_bio(struct bio *bio, int npg, enum req_op op, sector_t isect,
 
 	/* limit length to what the device mapping allows */
 	end = disk_addr + *len;
-	if (end >= map->start + map->len)
-		*len = map->start + map->len - disk_addr;
+	if (end >= map->disk_offset + map->len)
+		*len = map->disk_offset + map->len - disk_addr;
 
 retry:
 	if (!bio) {