scsi-reset-2.4.18.diff

SCSI reservation/reset handling

- Make both the old and the new error handlers respond correctly
  to reservation conflicts (i.e. return an I/O error).

- Add a scsi_reset_provider() function for use by the sg driver
  SCSI reset facility.

drivers/scsi/scsi.c

@@ -156,7 +156,12 @@ void scsi_build_commandblocks(Scsi_Device * SDpnt);
  */
 extern void scsi_old_done(Scsi_Cmnd * SCpnt);
 extern void scsi_old_times_out(Scsi_Cmnd * SCpnt);
+extern int scsi_old_reset(Scsi_Cmnd *SCpnt, unsigned int flag);
 
+/* 
+ * Private interface into the new error handling code.
+ */
+extern int scsi_new_reset(Scsi_Cmnd *SCpnt, unsigned int flag);
 
 /*
  * Function:    scsi_initialize_queue()
@@ -2722,6 +2727,102 @@ void scsi_free_host_dev(Scsi_Device * SDpnt)
         kfree(SDpnt);
 }
 
+/*
+ * Function:	scsi_reset_provider_done_command
+ *
+ * Purpose:	Dummy done routine.
+ *
+ * Notes:	Some low level drivers will call scsi_done and end up here,
+ *		others won't bother.
+ *		We don't want the bogus command used for the bus/device
+ *		reset to find its way into the mid-layer so we intercept
+ *		it here.
+ */
+static void
+scsi_reset_provider_done_command(Scsi_Cmnd *SCpnt)
+{
+}
+
+/*
+ * Function:	scsi_reset_provider
+ *
+ * Purpose:	Send requested reset to a bus or device at any phase.
+ *
+ * Arguments:	device	- device to send reset to
+ *		flag - reset type (see scsi.h)
+ *
+ * Returns:	SUCCESS/FAILURE.
+ *
+ * Notes:	This is used by the SCSI Generic driver to provide
+ *		Bus/Device reset capability.
+ */
+int
+scsi_reset_provider(Scsi_Device *dev, int flag)
+{
+	Scsi_Cmnd SC, *SCpnt = ≻
+	int rtn;
+
+	memset(&SCpnt->eh_timeout, 0, sizeof(SCpnt->eh_timeout));
+	SCpnt->host                    	= dev->host;
+	SCpnt->device                  	= dev;
+	SCpnt->target                  	= dev->id;
+	SCpnt->lun                     	= dev->lun;
+	SCpnt->channel                 	= dev->channel;
+	SCpnt->request.rq_status       	= RQ_SCSI_BUSY;
+	SCpnt->request.waiting        	= NULL;
+	SCpnt->use_sg                  	= 0;
+	SCpnt->old_use_sg              	= 0;
+	SCpnt->old_cmd_len             	= 0;
+	SCpnt->underflow               	= 0;
+	SCpnt->transfersize            	= 0;
+	SCpnt->resid			= 0;
+	SCpnt->serial_number           	= 0;
+	SCpnt->serial_number_at_timeout	= 0;
+	SCpnt->host_scribble           	= NULL;
+	SCpnt->next                    	= NULL;
+	SCpnt->state                   	= SCSI_STATE_INITIALIZING;
+	SCpnt->owner	     		= SCSI_OWNER_MIDLEVEL;
+    
+	memset(&SCpnt->cmnd, '\0', sizeof(SCpnt->cmnd));
+    
+	SCpnt->scsi_done		= scsi_reset_provider_done_command;
+	SCpnt->done			= NULL;
+	SCpnt->reset_chain		= NULL;
+        
+	SCpnt->buffer			= NULL;
+	SCpnt->bufflen			= 0;
+	SCpnt->request_buffer		= NULL;
+	SCpnt->request_bufflen		= 0;
+
+	SCpnt->internal_timeout		= NORMAL_TIMEOUT;
+	SCpnt->abort_reason		= DID_ABORT;
+
+	SCpnt->cmd_len			= 0;
+
+	SCpnt->sc_data_direction	= SCSI_DATA_UNKNOWN;
+	SCpnt->sc_request		= NULL;
+	SCpnt->sc_magic			= SCSI_CMND_MAGIC;
+
+	/*
+	 * Sometimes the command can get back into the timer chain,
+	 * so use the pid as an identifier.
+	 */
+	SCpnt->pid			= 0;
+
+	if (dev->host->hostt->use_new_eh_code) {
+		rtn = scsi_new_reset(SCpnt, flag);
+	} else {
+		unsigned long flags;
+
+		spin_lock_irqsave(&io_request_lock, flags);
+		rtn = scsi_old_reset(SCpnt, flag);
+		spin_unlock_irqrestore(&io_request_lock, flags);
+	}
+
+	scsi_delete_timer(SCpnt);
+	return rtn;
+}
+
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically

drivers/scsi/scsi.h

@@ -849,6 +849,16 @@ struct scsi_cmnd {
 	current->state = TASK_RUNNING;	\
     }; }
 
+/*
+ * old style reset request from external source
+ * (private to sg.c and scsi_error.c, supplied by scsi_obsolete.c)
+ */
+#define SCSI_TRY_RESET_DEVICE	1
+#define SCSI_TRY_RESET_BUS	2
+#define SCSI_TRY_RESET_HOST	3
+
+extern int scsi_reset_provider(Scsi_Device *, int);
+
 #endif
 
 /*

drivers/scsi/scsi_error.c

@@ -984,15 +984,24 @@ int scsi_decide_disposition(Scsi_Cmnd * SCpnt)
 	case DID_SOFT_ERROR:
 		goto maybe_retry;
 
+	case DID_ERROR:
+		if (msg_byte(SCpnt->result) == COMMAND_COMPLETE &&
+		    status_byte(SCpnt->result) == RESERVATION_CONFLICT)
+			/*
+			 * execute reservation conflict processing code
+			 * lower down
+			 */
+			break;
+		/* FALLTHROUGH */
+
 	case DID_BUS_BUSY:
 	case DID_PARITY:
-	case DID_ERROR:
 		goto maybe_retry;
 	case DID_TIME_OUT:
 		/*
-		   * When we scan the bus, we get timeout messages for
-		   * these commands if there is no device available.
-		   * Other hosts report DID_NO_CONNECT for the same thing.
+		 * When we scan the bus, we get timeout messages for
+		 * these commands if there is no device available.
+		 * Other hosts report DID_NO_CONNECT for the same thing.
 		 */
 		if ((SCpnt->cmnd[0] == TEST_UNIT_READY ||
 		     SCpnt->cmnd[0] == INQUIRY)) {
@@ -1053,8 +1062,13 @@ int scsi_decide_disposition(Scsi_Cmnd * SCpnt)
 		 */
 		return SUCCESS;
 	case BUSY:
-	case RESERVATION_CONFLICT:
 		goto maybe_retry;
+
+	case RESERVATION_CONFLICT:
+		printk("scsi%d (%d,%d,%d) : RESERVATION CONFLICT\n", 
+		       SCpnt->host->host_no, SCpnt->channel,
+		       SCpnt->device->id, SCpnt->device->lun);
+		return SUCCESS; /* causes immediate I/O error */
 	default:
 		return FAILED;
 	}
@@ -1959,6 +1973,45 @@ void scsi_error_handler(void *data)
 		up(host->eh_notify);
 }
 
+/*
+ * Function:	scsi_new_reset
+ *
+ * Purpose:	Send requested reset to a bus or device at any phase.
+ *
+ * Arguments:	SCpnt	- command ptr to send reset with (usually a dummy)
+ *		flag - reset type (see scsi.h)
+ *
+ * Returns:	SUCCESS/FAILURE.
+ *
+ * Notes:	This is used by the SCSI Generic driver to provide
+ *		Bus/Device reset capability.
+ */
+int
+scsi_new_reset(Scsi_Cmnd *SCpnt, int flag)
+{
+	int rtn;
+
+	switch(flag) {
+	case SCSI_TRY_RESET_DEVICE:
+		rtn = scsi_try_bus_device_reset(SCpnt, 0);
+		if (rtn == SUCCESS)
+			break;
+		/* FALLTHROUGH */
+	case SCSI_TRY_RESET_BUS:
+		rtn = scsi_try_bus_reset(SCpnt);
+		if (rtn == SUCCESS)
+			break;
+		/* FALLTHROUGH */
+	case SCSI_TRY_RESET_HOST:
+		rtn = scsi_try_host_reset(SCpnt);
+		break;
+	default:
+		rtn = FAILED;
+	}
+
+	return rtn;
+}
+
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically

drivers/scsi/scsi_obsolete.c

@@ -503,11 +503,18 @@ void scsi_old_done(Scsi_Cmnd * SCpnt)
 					break;
 
 				case RESERVATION_CONFLICT:
-					printk("scsi%d, channel %d : RESERVATION CONFLICT performing"
-					       " reset.\n", SCpnt->host->host_no, SCpnt->channel);
-					scsi_reset(SCpnt, SCSI_RESET_SYNCHRONOUS);
-					status = REDO;
+					/*
+					 * Most HAs will return an error for
+					 * this, so usually reservation
+					 * conflicts will  be processed under
+					 * DID_ERROR code
+					 */
+					printk("scsi%d (%d,%d,%d) : RESERVATION CONFLICT\n", 
+					       SCpnt->host->host_no, SCpnt->channel,
+					       SCpnt->device->id, SCpnt->device->lun);
+					status = CMD_FINISHED; /* returns I/O error */
 					break;
+                                        
 				default:
 					printk("Internal error %s %d \n"
 					 "status byte = %d \n", __FILE__,
@@ -557,6 +564,14 @@ void scsi_old_done(Scsi_Cmnd * SCpnt)
 		exit = (DRIVER_HARD | SUGGEST_ABORT);
 		break;
 	case DID_ERROR:
+		if (msg_byte(result) == COMMAND_COMPLETE &&
+		    status_byte(result) == RESERVATION_CONFLICT) {
+			printk("scsi%d (%d,%d,%d) : RESERVATION CONFLICT\n", 
+			       SCpnt->host->host_no, SCpnt->channel,
+			       SCpnt->device->id, SCpnt->device->lun);
+			status = CMD_FINISHED; /* returns I/O error */
+			break;
+		}
 		status = MAYREDO;
 		exit = (DRIVER_HARD | SUGGEST_ABORT);
 		break;
@@ -1099,6 +1114,34 @@ int update_timeout(Scsi_Cmnd * SCset, int timeout)
 }
 
 
+/*
+ * This function exports SCSI Bus, Device or Host reset capability
+ * and is for use with the SCSI generic driver.
+ */
+int
+scsi_old_reset(Scsi_Cmnd *SCpnt, unsigned int flag)
+{
+	unsigned int old_flags = SCSI_RESET_SYNCHRONOUS;
+
+	switch(flag) {
+	case SCSI_TRY_RESET_DEVICE:
+		/* no suggestion flags to add, device reset is default */
+		break;
+	case SCSI_TRY_RESET_BUS:
+		old_flags |= SCSI_RESET_SUGGEST_BUS_RESET;
+		break;
+	case SCSI_TRY_RESET_HOST:
+		old_flags |= SCSI_RESET_SUGGEST_HOST_RESET;
+		break;
+	default:
+		return FAILED;
+	}
+
+	if (scsi_reset(SCpnt, old_flags))
+		return FAILED;
+	return SUCCESS;
+}
+
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically

drivers/scsi/scsi_syms.c

@@ -83,6 +83,11 @@ EXPORT_SYMBOL(scsi_end_request);
 EXPORT_SYMBOL(scsi_register_blocked_host);
 EXPORT_SYMBOL(scsi_deregister_blocked_host);
 
+/*
+ * This symbol is for the highlevel drivers (e.g. sg) only.
+ */
+EXPORT_SYMBOL(scsi_reset_provider);
+
 /*
  * These are here only while I debug the rest of the scsi stuff.
  */