Signed-off-by: added [Re: [PATCH]: Flexible timeout infrastructure]

Luben Tuikov
2004-06-15T15:08:57Z

Signed-off-by: Luben Tuikov <luben_tuikov@adaptec.com>

===== drivers/scsi/scsi.c 1.143 vs edited =====
--- 1.143/drivers/scsi/scsi.c 2004-04-28 12:32:09 -04:00
+++ edited/drivers/scsi/scsi.c 2004-06-14 15:13:12 -04:00
@@ -549,7 +549,12 @@
host->resetting = 0;
}

- scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out);
+ /* If the LLDD claims to be able to handle its own command timeout,
+ * don't start the timer. It will start it before sending the command
+ * to the LU.
+ */
+ if (!host->hostt->eh_cmd_timed_out)
+ scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out);

scsi_log_send(cmd);

@@ -699,8 +704,9 @@
* that function could really be. It might be on another processor,
* etc, etc.
*/
- if (!scsi_delete_timer(cmd))
- return;
+ if (!cmd->device->host->hostt->eh_cmd_timed_out)
+ if (!scsi_delete_timer(cmd))
+ return;

/*
* Set the serial numbers back to zero
===== drivers/scsi/scsi_error.c 1.76 vs edited =====
--- 1.76/drivers/scsi/scsi_error.c 2004-06-04 12:54:06 -04:00
+++ edited/drivers/scsi/scsi_error.c 2004-06-14 15:13:53 -04:00
@@ -155,8 +155,8 @@
}

/**
- * scsi_times_out - Timeout function for normal scsi commands.
- * @scmd: Cmd that is timing out.
+ * scsi_times_out - Timeout function for normal SCSI commands.
+ * @scmd: Command that is timing out.
*
* Notes:
* We do not need to lock this. There is the potential for a race
@@ -166,7 +166,16 @@
**/
void scsi_times_out(struct scsi_cmnd *scmd)
{
+ int ret = EH_NONE;
+
scsi_log_completion(scmd, TIMEOUT_ERROR);
+
+ if (scmd->device->host->hostt->eh_cmd_timed_out)
+ ret = scmd->device->host->hostt->eh_cmd_timed_out(scmd);
+
+ if (ret == EH_HANDLED)
+ return;
+
if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
panic("Error handler thread not present at %p %p %s %d",
scmd, scmd->device->host, __FILE__, __LINE__);
===== drivers/scsi/scsi_syms.c 1.47 vs edited =====
--- 1.47/drivers/scsi/scsi_syms.c 2004-05-19 13:46:14 -04:00
+++ edited/drivers/scsi/scsi_syms.c 2004-06-14 11:09:29 -04:00
@@ -107,3 +107,4 @@
*/
EXPORT_SYMBOL(scsi_add_timer);
EXPORT_SYMBOL(scsi_delete_timer);
+EXPORT_SYMBOL(scsi_times_out);
===== include/scsi/scsi.h 1.21 vs edited =====
--- 1.21/include/scsi/scsi.h 2004-04-21 12:54:43 -04:00
+++ edited/include/scsi/scsi.h 2004-06-14 14:33:15 -04:00
@@ -327,6 +327,12 @@
#define SCSI_MLQUEUE_EH_RETRY 0x1057

/*
+ * LLDD timeout handler return values
+ */
+#define EH_NONE (0)
+#define EH_HANDLED (1)
+
+/*
* Use these to separate status msg and our bytes
*
* These are set by:
===== include/scsi/scsi_eh.h 1.2 vs edited =====
--- 1.2/include/scsi/scsi_eh.h 2004-06-04 07:45:01 -04:00
+++ edited/include/scsi/scsi_eh.h 2004-06-14 11:12:13 -04:00
@@ -7,10 +7,11 @@

extern void scsi_add_timer(struct scsi_cmnd *, int,
void (*)(struct scsi_cmnd *));
-extern int scsi_delete_timer(struct scsi_cmnd *);
+extern int scsi_delete_timer(struct scsi_cmnd *);
+extern void scsi_times_out(struct scsi_cmnd *);
extern void scsi_report_bus_reset(struct Scsi_Host *, int);
extern void scsi_report_device_reset(struct Scsi_Host *, int, int);
-extern int scsi_block_when_processing_errors(struct scsi_device *);
+extern int scsi_block_when_processing_errors(struct scsi_device *);
extern void scsi_sleep(int);

/*
===== include/scsi/scsi_host.h 1.17 vs edited =====
--- 1.17/include/scsi/scsi_host.h 2004-06-04 12:51:31 -04:00
+++ edited/include/scsi/scsi_host.h 2004-06-14 15:12:23 -04:00
@@ -125,6 +125,40 @@
int (* eh_bus_reset_handler)(struct scsi_cmnd *);
int (* eh_host_reset_handler)(struct scsi_cmnd *);

+
+ /*
+ * If defined, SCSI Core will leave _all_ command timeout
+ * handling to the LLDD. The LLDD should call
+ * scsi_add_timer(<cmd>,<timeout>,scsi_times_out) when
+ * appropriate, possibly before sending the command to the LU,
+ * and scsi_delete_timer(<cmd>) before returning it to SCSI
+ * Core. That is, a SCSI command is passed to the LLDD (via
+ * queuecommand()) _without_ a timer running and is expected
+ * to be returned to SCSI Core (via scsi_done()) just the
+ * same, without one running.
+ *
+ * This method is called whenever a SCSI command times out, if
+ * the driver had called
+ * scsi_add_timer(<cmd>,<timeout>,scsi_times_out) of course.
+ *
+ * Returns: EH_HANDLED or EH_NONE.
+ * EH_HANDLED -- means that the LLDD has taken all steps
+ * to ensure proper command recovery handling and had
+ * A) either called scsi_done() and set the response/result
+ * properly in the SCSI command structure,
+ * XOR
+ * B) resent the command to the LU.
+ * EH_NONE -- SCSI Core should try to recover the command as
+ * usual (eh recovery thread, etc).
+ *
+ * If this method is not defined, current/old behaviour is assumed.
+ *
+ * NOTE: This runs in interrupt context, so it cannot sleep.
+ *
+ * STATUS: OPTIONAL
+ */
+ int (* eh_cmd_timed_out)(struct scsi_cmnd *);
+
/*
* Old EH handlers, no longer used. Make them warn the user of old
* drivers by using a wrong type