Attached is an addition to the patches on this driver that

I've been posting recently. This one adds:
   - slave_attach() and slave_detach()
   - code clean up looking for a problem **
   - more debug code allowing scanning cmd sequence to
     be seen in the log (when opts=1)

** after several (never the first) sequences of modprobe/rmmod
on scsi_debug there is either:
   - an oops during modprobe when driverfs tries to create a
     directory
   - or a WARN_ON() at drivers/base/bus.c:277 during rmmod
[examples attached]

I'm not sure whether the problem is in scsi_debug, the
scsi mid level or in the driverfs code. Grepping indicates
that not many people currently utilize per driver parameters
with driverfs (i.e. driver_create_file() and
driver_remove_file()).

drivers/scsi/scsi_debug.h

@@ -3,17 +3,20 @@
 #include <linux/types.h>
 #include <linux/kdev_t.h>
 
-static int scsi_debug_detect(Scsi_Host_Template *);
+static int scsi_debug_detect(struct SHT *);
+static int scsi_debug_slave_attach(struct scsi_device *);
+static void scsi_debug_slave_detach(struct scsi_device *);
 static int scsi_debug_release(struct Scsi_Host *);
-/* static int scsi_debug_command(Scsi_Cmnd *); */
-static int scsi_debug_queuecommand(Scsi_Cmnd *, void (*done) (Scsi_Cmnd *));
-static int scsi_debug_ioctl(Scsi_Device *, int, void *);
+/* static int scsi_debug_command(struct scsi_cmnd *); */
+static int scsi_debug_queuecommand(struct scsi_cmnd *, 
+				   void (*done) (struct scsi_cmnd *));
+static int scsi_debug_ioctl(struct scsi_device *, int, void *);
 static int scsi_debug_biosparam(struct scsi_device *, struct block_device *,
 		sector_t, int[]);
-static int scsi_debug_abort(Scsi_Cmnd *);
-static int scsi_debug_bus_reset(Scsi_Cmnd *);
-static int scsi_debug_device_reset(Scsi_Cmnd *);
-static int scsi_debug_host_reset(Scsi_Cmnd *);
+static int scsi_debug_abort(struct scsi_cmnd *);
+static int scsi_debug_bus_reset(struct scsi_cmnd *);
+static int scsi_debug_device_reset(struct scsi_cmnd *);
+static int scsi_debug_host_reset(struct scsi_cmnd *);
 static int scsi_debug_proc_info(char *, char **, off_t, int, int, int);
 static const char * scsi_debug_info(struct Scsi_Host *);
 
@@ -33,6 +36,8 @@ static Scsi_Host_Template driver_template = {
 	.name =			"SCSI DEBUG",
 	.info =			scsi_debug_info,
 	.detect =		scsi_debug_detect,
+	.slave_attach =		scsi_debug_slave_attach,
+	.slave_detach =		scsi_debug_slave_detach,
 	.release =		scsi_debug_release,
 	.ioctl =		scsi_debug_ioctl,
 	.queuecommand =		scsi_debug_queuecommand,