[SCSI] add global timeout to the scsi mid-layer
There are certain rogue devices (and the aic7xxx driver) that return
BUSY or QUEUE_FULL forever. This code will apply a global timeout (of
the total number of retries times the per command timer) to a given
command. If it is exceeded, the command is completed regardless of its
state.
The patch also removes the unused field in the command: timeout and
timeout_total.
This solves the problem of detecting an endless loop in the mid-layer
because of BUSY/QUEUE_FULL bouncing, but will not recover the device.
In the aic7xxx case, the driver can be recovered by sending a bus reset,
so possibly this should be tied into the error handler?
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 9957f16..bed4b7c 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -51,12 +51,16 @@
* printk's to use ->pid, so that we can kill this field.
*/
unsigned long serial_number;
+ /*
+ * This is set to jiffies as it was when the command was first
+ * allocated. It is used to time how long the command has
+ * been outstanding
+ */
+ unsigned long jiffies_at_alloc;
int retries;
int allowed;
int timeout_per_command;
- int timeout_total;
- int timeout;
unsigned char cmd_len;
unsigned char old_cmd_len;