[PATCH] scsi: remove meaningless scsi_cmnd->serial_number_at_timeout field
scsi_cmnd->serial_number_at_timeout doesn't serve any purpose
anymore. All serial_number == serial_number_at_timeout tests
are always true in abort callbacks. Kill the field. Also, as
->pid always equals ->serial_number and ->serial_number
doesn't have any special meaning anymore, update comments
above ->serial_number accordingly. Once we remove all uses of
this field from all lldd's, this field should go.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index ae45d6f..07f5c69 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -43,21 +43,17 @@
void (*done) (struct scsi_cmnd *); /* Mid-level done function */
/*
- * A SCSI Command is assigned a nonzero serial_number when internal_cmnd
- * passes it to the driver's queue command function. The serial_number
- * is cleared when scsi_done is entered indicating that the command has
- * been completed. If a timeout occurs, the serial number at the moment
- * of timeout is copied into serial_number_at_timeout. By subsequently
- * comparing the serial_number and serial_number_at_timeout fields
- * during abort or reset processing, we can detect whether the command
- * has already completed. This also detects cases where the command has
- * completed and the SCSI Command structure has already being reused
- * for another command, so that we can avoid incorrectly aborting or
- * resetting the new command.
- * The serial number is only unique per host.
+ * A SCSI Command is assigned a nonzero serial_number before passed
+ * to the driver's queue command function. The serial_number is
+ * cleared when scsi_done is entered indicating that the command
+ * has been completed. It currently doesn't have much use other
+ * than printk's. Some lldd's use this number for other purposes.
+ * It's almost certain that such usages are either incorrect or
+ * meaningless. Please kill all usages other than printk's. Also,
+ * as this number is always identical to ->pid, please convert
+ * printk's to use ->pid, so that we can kill this field.
*/
unsigned long serial_number;
- unsigned long serial_number_at_timeout;
int retries;
int allowed;