[PATCH] usb-storage: remove BUG/BUG_ON

This patch changes BUG and BUG_ON to print error messages.  It is done to
be (a) a little more robust, and (b) complies with Linus' idea of no BUGs
unless absolutely necessary.

drivers/usb/storage/scsiglue.c

@@ -141,13 +141,19 @@ static int usb_storage_release(struct Scsi_Host *psh)
 static int usb_storage_queuecommand( Scsi_Cmnd *srb , void (*done)(Scsi_Cmnd *))
 {
 	struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
+	int state = atomic_read(&us->sm_state);
 
 	US_DEBUGP("queuecommand() called\n");
 	srb->host_scribble = (unsigned char *)us;
 
 	/* enqueue the command */
-	BUG_ON(atomic_read(&us->sm_state) != US_STATE_IDLE);
-	BUG_ON(us->srb != NULL);
+	if (state != US_STATE_IDLE || us->srb != NULL) {
+		printk(KERN_ERR USB_STORAGE "Error in %s: " 
+			"state = %d, us->srb = %p\n",
+			__FUNCTION__, state, us->srb);
+		return SCSI_MLQUEUE_HOST_BUSY;
+	}
+
 	srb->scsi_done = done;
 	us->srb = srb;
 
@@ -175,8 +181,7 @@ static int usb_storage_command_abort( Scsi_Cmnd *srb )
 		return FAILED;
 	}
 
-	usb_stor_abort_transport(us);
-	return SUCCESS;
+	return usb_stor_abort_transport(us);
 }
 
 /* This invokes the transport reset mechanism to reset the state of the
@@ -185,10 +190,15 @@ static int usb_storage_command_abort( Scsi_Cmnd *srb )
 static int usb_storage_device_reset( Scsi_Cmnd *srb )
 {
 	struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
+	int state = atomic_read(&us->sm_state);
 	int result;
 
 	US_DEBUGP("device_reset() called\n" );
-	BUG_ON(atomic_read(&us->sm_state) != US_STATE_IDLE);
+	if (state != US_STATE_IDLE) {
+		printk(KERN_ERR USB_STORAGE "Error in %s: "
+			"invalid state %d\n", __FUNCTION__, state);
+		return FAILED;
+	}
 
 	/* set the state and release the lock */
 	atomic_set(&us->sm_state, US_STATE_RESETTING);

drivers/usb/storage/transport.c

@@ -692,7 +692,7 @@ void usb_stor_invoke_transport(Scsi_Cmnd *srb, struct us_data *us)
 
 /* Abort the currently running scsi command or device reset.
  * This must be called with scsi_lock(us->srb->host) held */
-void usb_stor_abort_transport(struct us_data *us)
+int usb_stor_abort_transport(struct us_data *us)
 {
 	struct Scsi_Host *host;
 	int state = atomic_read(&us->sm_state);
@@ -702,7 +702,11 @@ void usb_stor_abort_transport(struct us_data *us)
 	/* Normally the current state is RUNNING.  If the control thread
 	 * hasn't even started processing this command, the state will be
 	 * IDLE.  Anything else is a bug. */
-	BUG_ON((state != US_STATE_RUNNING && state != US_STATE_IDLE));
+	if (state != US_STATE_RUNNING && state != US_STATE_IDLE) {
+		printk(KERN_ERR USB_STORAGE "Error in %s: "
+			"invalid state %d\n", __FUNCTION__, state);
+		return FAILED;
+	}
 
 	/* set state to abort and release the lock */
 	atomic_set(&us->sm_state, US_STATE_ABORTING);
@@ -731,6 +735,7 @@ void usb_stor_abort_transport(struct us_data *us)
 
 	/* Reacquire the lock: note that us->srb is now NULL */
 	scsi_lock(host);
+	return SUCCESS;
 }
 
 /*

drivers/usb/storage/transport.h

@@ -154,7 +154,7 @@ extern int usb_stor_Bulk_max_lun(struct us_data*);
 extern int usb_stor_Bulk_reset(struct us_data*);
 
 extern void usb_stor_invoke_transport(Scsi_Cmnd*, struct us_data*);
-extern void usb_stor_abort_transport(struct us_data*);
+extern int usb_stor_abort_transport(struct us_data*);
 
 extern int usb_stor_bulk_msg(struct us_data *us, void *data,
 		unsigned int pipe, unsigned int len, unsigned int *act_len);

drivers/usb/storage/usb.c

@@ -935,11 +935,6 @@ static void storage_disconnect(struct usb_interface *intf)
 	us = usb_get_intfdata(intf);
 	usb_set_intfdata(intf, NULL);
 
-	/* serious error -- we're attempting to disconnect an interface but
-	 * cannot locate the local data structure
-	 */
-	BUG_ON(us == NULL);
-
 	/* set devices offline -- need host lock for this */
 	scsi_lock(us->host);
 	list_for_each_entry(sdev, &us->host->my_devices, siblings)