--- linux/drivers/scsi/sd.c	2005-05-07 16:18:00.000000000 +1000
+++ linux/drivers/scsi/sd.c2612rc4resid	2005-05-08 12:36:34.000000000 +1000
@@ -843,6 +843,9 @@
 {
 	int result = SCpnt->result;
 	int this_count = SCpnt->bufflen;
+	int resid = SCpnt->resid;
+	int opcode = SCpnt->cmnd[0];
+	struct request * req = SCpnt->request;
 	int good_bytes = (result == 0 ? this_count : 0);
 	sector_t block_sectors = 1;
 	u64 first_err_block;
@@ -859,12 +862,18 @@
 	}
 
 #ifdef CONFIG_SCSI_LOGGING
-	SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 
-				SCpnt->request->rq_disk->disk_name, result));
+	SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: opcode=0x%x "
+				"res=0x%x\n", req->rq_disk->disk_name,
+				opcode, result));
 	if (sense_valid) {
-		SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc,"
-				"ascq]=%x,%x,%x,%x\n", sshdr.response_code,
-				sshdr.sense_key, sshdr.asc, sshdr.ascq));
+		SCSI_LOG_HLCOMPLETE(1, printk("  sd_rw_intr: sb[respc,sk,asc,"
+				"ascq]=%x,%x,%x,%x  %s\n",
+			sshdr.response_code, sshdr.sense_key, sshdr.asc,
+			sshdr.ascq, (sense_deferred ? "DEFERRED" : "")));
+	}
+	if (resid) {
+		SCSI_LOG_HLCOMPLETE(1, printk("  sd_rw_intr: resid=%d\n",
+					resid));
 	}
 #endif
 	/*
@@ -878,13 +887,13 @@
 	 * else if errors, check them, and if necessary prepare for
 	 * (partial) retries.
 	 */
-	if (blk_pc_request(SCpnt->request))
+	if (blk_pc_request(req))
 		good_bytes = this_count;
 	else if (driver_byte(result) != 0 &&
 		 sense_valid && !sense_deferred) {
 		switch (sshdr.sense_key) {
 		case MEDIUM_ERROR:
-			if (!blk_fs_request(SCpnt->request))
+			if (!blk_fs_request(req))
 				break;
 			info_valid = scsi_get_sense_info_fld(
 				SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE,
@@ -894,8 +903,8 @@
 			 * in actual truncation (if sector_t < 64 bits)
 			 */
 			error_sector = (sector_t)first_err_block;
-			if (SCpnt->request->bio != NULL)
-				block_sectors = bio_sectors(SCpnt->request->bio);
+			if (req->bio != NULL)
+				block_sectors = bio_sectors(req->bio);
 			switch (SCpnt->device->sector_size) {
 			case 1024:
 				error_sector <<= 1;
@@ -920,7 +929,7 @@
 			}
 
 			error_sector &= ~(block_sectors - 1);
-			good_bytes = (error_sector - SCpnt->request->sector) << 9;
+			good_bytes = (error_sector - req->sector) << 9;
 			if (good_bytes < 0 || good_bytes >= this_count)
 				good_bytes = 0;
 			break;
@@ -930,6 +939,10 @@
 			/*
 			 * Inform the user, but make sure that it's not treated
 			 * as a hard error.
+			 * N.B. This could be a "Failure prediction threshold
+			 * exceeded" type message (depending on MRIE setting
+			 * in IEC mode page). Ignore such a message at your
+			 * peril.
 			 */
 			scsi_print_sense("sd", SCpnt);
 			SCpnt->result = 0;
@@ -939,18 +952,45 @@
 
 		case ILLEGAL_REQUEST:
 			if (SCpnt->device->use_10_for_rw &&
-			    (SCpnt->cmnd[0] == READ_10 ||
-			     SCpnt->cmnd[0] == WRITE_10))
+			    (opcode == READ_10 || opcode == WRITE_10))
 				SCpnt->device->use_10_for_rw = 0;
 			if (SCpnt->device->use_10_for_ms &&
-			    (SCpnt->cmnd[0] == MODE_SENSE_10 ||
-			     SCpnt->cmnd[0] == MODE_SELECT_10))
+			    (opcode == MODE_SENSE_10 ||
+			     opcode == MODE_SELECT_10))
 				SCpnt->device->use_10_for_ms = 0;
 			break;
 
 		default:
 			break;
 		}
+	} else if ((resid > 0) &&
+		((opcode == READ_6) || (opcode == READ_10) ||
+		 (opcode == READ_16))) {
+		/*
+		 * During a read operation the LLD DMA element has indicated
+		 * that less bytes were read than requested.
+		 * Assume truncated DMA transfers on WRITE operations
+		 * are reported by device.
+		 */
+		if (req->bio != NULL)
+			block_sectors = bio_sectors(req->bio);
+		switch (SCpnt->device->sector_size) {
+		case 1024:
+			if (block_sectors < 2)
+				block_sectors = 2;
+			break;
+		case 2048:
+			if (block_sectors < 4)
+				block_sectors = 4;
+			break;
+		case 4096:
+			if (block_sectors < 8)
+				block_sectors = 8;
+			break;
+		default:
+			break;
+		}
+		good_bytes = (this_count > resid) ? (this_count - resid) : 0;
 	}
 	/*
 	 * This calls the generic completion function, now that we know