All REQ_BLOCK_PC requests are bio backed now.
This patch was made against 2.6.12-rc5 but works with scsi-misc.
--- linux-2.6.12-rc5.orig/drivers/scsi/scsi_lib.c 2005-06-03 03:23:47.000000000 -0700
+++ linux-2.6.12-rc5/drivers/scsi/scsi_lib.c 2005-06-03 14:31:41.000000000 -0700
@@ -920,24 +920,19 @@ static int scsi_init_io(struct scsi_cmnd
int count;
/*
- * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer
+ * we use scatter-gather for all requests with data
+ * (it makes highmem I/O easier to support without kmapping pages)
*/
- if ((req->flags & REQ_BLOCK_PC) && !req->bio) {
- cmd->request_bufflen = req->data_len;
- cmd->request_buffer = req->data;
- req->buffer = req->data;
- cmd->use_sg = 0;
+ cmd->use_sg = req->nr_phys_segments;
+ if (!cmd->use_sg) {
+ BUG_ON(req->bio || req->data);
+ cmd->request_bufflen = 0;
+ cmd->request_buffer = NULL;
+ req->buffer = NULL;
return 0;
}
/*
- * we used to not use scatter-gather for single segment request,
- * but now we do (it makes highmem I/O easier to support without
- * kmapping pages)
- */
- cmd->use_sg = req->nr_phys_segments;
-
- /*
* if sg table allocation fails, requeue request later.
*/
sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
