u64 start, u64 len)
 {
        u64 offset;
-       int nsectors;
+       u64 nsectors64;
+       u32 nsectors;
        int sectorsize = sparity->sctx->fs_info->sectorsize;
 
        if (len >= sparity->stripe_len) {
        start -= sparity->logic_start;
        start = div64_u64_rem(start, sparity->stripe_len, &offset);
        offset = div_u64(offset, sectorsize);
-       nsectors = (int)len / sectorsize;
+       nsectors64 = div_u64(len, sectorsize);
+
+       ASSERT(nsectors64 < UINT_MAX);
+       nsectors = (u32)nsectors64;
 
        if (offset + nsectors <= sparity->nsectors) {
                bitmap_set(bitmap, offset, nsectors);