4185 New hash algorithm support

*** 978,988 ****
          if (buf->b_hdr->b_freeze_cksum == NULL ||
              (buf->b_hdr->b_flags & ARC_IO_ERROR)) {
                  mutex_exit(&buf->b_hdr->b_freeze_lock);
                  return;
          }
!         fletcher_2_native(buf->b_data, buf->b_hdr->b_size, &zc);
          if (!ZIO_CHECKSUM_EQUAL(*buf->b_hdr->b_freeze_cksum, zc))
                  panic("buffer modified while frozen!");
          mutex_exit(&buf->b_hdr->b_freeze_lock);
  }
  
--- 978,988 ----
          if (buf->b_hdr->b_freeze_cksum == NULL ||
              (buf->b_hdr->b_flags & ARC_IO_ERROR)) {
                  mutex_exit(&buf->b_hdr->b_freeze_lock);
                  return;
          }
!         fletcher_2_native(buf->b_data, buf->b_hdr->b_size, NULL, NULL, &zc);
          if (!ZIO_CHECKSUM_EQUAL(*buf->b_hdr->b_freeze_cksum, zc))
                  panic("buffer modified while frozen!");
          mutex_exit(&buf->b_hdr->b_freeze_lock);
  }
  
*** 991,1001 ****
  {
          zio_cksum_t zc;
          int equal;
  
          mutex_enter(&buf->b_hdr->b_freeze_lock);
!         fletcher_2_native(buf->b_data, buf->b_hdr->b_size, &zc);
          equal = ZIO_CHECKSUM_EQUAL(*buf->b_hdr->b_freeze_cksum, zc);
          mutex_exit(&buf->b_hdr->b_freeze_lock);
  
          return (equal);
  }
--- 991,1001 ----
  {
          zio_cksum_t zc;
          int equal;
  
          mutex_enter(&buf->b_hdr->b_freeze_lock);
!         fletcher_2_native(buf->b_data, buf->b_hdr->b_size, NULL, NULL, &zc);
          equal = ZIO_CHECKSUM_EQUAL(*buf->b_hdr->b_freeze_cksum, zc);
          mutex_exit(&buf->b_hdr->b_freeze_lock);
  
          return (equal);
  }
*** 1010,1020 ****
          if (buf->b_hdr->b_freeze_cksum != NULL) {
                  mutex_exit(&buf->b_hdr->b_freeze_lock);
                  return;
          }
          buf->b_hdr->b_freeze_cksum = kmem_alloc(sizeof (zio_cksum_t), KM_SLEEP);
!         fletcher_2_native(buf->b_data, buf->b_hdr->b_size,
              buf->b_hdr->b_freeze_cksum);
          mutex_exit(&buf->b_hdr->b_freeze_lock);
          arc_buf_watch(buf);
  }
  
--- 1010,1020 ----
          if (buf->b_hdr->b_freeze_cksum != NULL) {
                  mutex_exit(&buf->b_hdr->b_freeze_lock);
                  return;
          }
          buf->b_hdr->b_freeze_cksum = kmem_alloc(sizeof (zio_cksum_t), KM_SLEEP);
!         fletcher_2_native(buf->b_data, buf->b_hdr->b_size, NULL, NULL,
              buf->b_hdr->b_freeze_cksum);
          mutex_exit(&buf->b_hdr->b_freeze_lock);
          arc_buf_watch(buf);
  }