[PATCH] misc scsi bits

Various small bits that make SCSI work well with REQ_BLOCK_PC.

o Use ->errors as the scsi status byte for REQ_BLOCK_PC

o Always call end_io completion, even if 0 sectors, as long as the
  status is good. Otherwise we risk hanging this device if a
  REQ_BLOCK_PC user command didn't specify a transfer size for a command
  that did.

o Remove bouncing checks in scsi_merge for REQ_BLOCK_PC, bio_map_user()
  correctly bounces pages now.

o Decrement req->data_len, it's our residual data count.

o sr/sd: set right transfer and underflow size.

drivers/scsi/scsi_lib.c

@@ -514,6 +514,12 @@ void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
 		}
 	}
 
+	if (blk_pc_request(req)) {
+		req->errors = result & 0xff;
+		if (!result)
+			req->data_len -= SCpnt->bufflen;
+	}
+
 	/*
 	 * Zero these out.  They now point to freed memory, and it is
 	 * dangerous to hang onto the pointers.
@@ -527,7 +533,7 @@ void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
 	 * Next deal with any sectors which we were able to correctly
 	 * handle.
 	 */
-	if (good_sectors > 0) {
+	if (good_sectors >= 0) {
 		SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, %d sectors done.\n",
 					      req->nr_sectors, good_sectors));
 		SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n ", SCpnt->use_sg));

drivers/scsi/scsi_merge.c

@@ -62,15 +62,9 @@ int scsi_init_io(Scsi_Cmnd *SCpnt)
 	int count, gfp_mask;
 
 	/*
-	 * non-sg block request. FIXME: check bouncing for isa hosts!
+	 * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer
 	 */
 	if ((req->flags & REQ_BLOCK_PC) && !req->bio) {
-		/*
-		 * FIXME: isa bouncing
-		 */
-		if (SCpnt->host->unchecked_isa_dma)
-			goto fail;
-
 		SCpnt->request_bufflen = req->data_len;
 		SCpnt->request_buffer = req->data;
 		req->buffer = req->data;
@@ -100,6 +94,8 @@ int scsi_init_io(Scsi_Cmnd *SCpnt)
 
 	SCpnt->request_buffer = (char *) sgpnt;
 	SCpnt->request_bufflen = req->nr_sectors << 9;
+	if (blk_pc_request(req))
+		SCpnt->request_bufflen = req->data_len;
 	req->buffer = NULL;
 
 	/* 
@@ -123,7 +119,6 @@ int scsi_init_io(Scsi_Cmnd *SCpnt)
 	/*
 	 * kill it. there should be no leftover blocks in this request
 	 */
-fail:
 	SCpnt = scsi_end_request(SCpnt, 0, req->nr_sectors);
 	BUG_ON(SCpnt);
 	return 0;

drivers/scsi/sd.c

@@ -308,6 +308,8 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 		if (rq->timeout)
 			timeout = rq->timeout;
 
+		SCpnt->transfersize = rq->data_len;
+		SCpnt->underflow = rq->data_len;
 		goto queue;
 	}
 
@@ -431,10 +433,10 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 	 * host adapter, it's safe to assume that we can at least transfer
 	 * this many bytes between each connect / disconnect.
 	 */
-queue:
 	SCpnt->transfersize = sdp->sector_size;
 	SCpnt->underflow = this_count << 9;
 
+queue:
 	SCpnt->allowed = MAX_RETRIES;
 	SCpnt->timeout_per_command = timeout;
 

drivers/scsi/sr.c

@@ -287,6 +287,8 @@ static int sr_init_command(Scsi_Cmnd * SCpnt)
 		if (rq->timeout)
 			timeout = rq->timeout;
 
+		SCpnt->transfersize = rq->data_len;
+		SCpnt->underflow = rq->data_len;
 		goto queue;
 	}
 
@@ -360,10 +362,10 @@ static int sr_init_command(Scsi_Cmnd * SCpnt)
 	 * host adapter, it's safe to assume that we can at least transfer
 	 * this many bytes between each connect / disconnect.
 	 */
-queue:
 	SCpnt->transfersize = cd->device->sector_size;
 	SCpnt->underflow = this_count << 9;
 
+queue:
 	SCpnt->allowed = MAX_RETRIES;
 	SCpnt->timeout_per_command = timeout;