usbmon: bus zero

Add the "bus zero" feature to the usbmon. If a user process specifies bus
with number zero, it receives events from all buses. This is useful when
we wish to see initial enumeration when a bus is created, typically after
a modprobe. Until now, an application had to loop until a new bus could
be open, then start capturing on it. This procedure was cumbersome and
could lose initial events. Also, often it's too bothersome to find exactly
to which bus a specific device is attached.

Paolo Albeni provided the original concept implementation. I added the
handling of "bus->monitored" flag and generally fixed it up.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index a1e2b8e9d77..13d63255283 100644
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -23,7 +23,6 @@ struct mon_bus {
 	struct dentry *dent_s;		/* Debugging file */
 	struct dentry *dent_t;		/* Text interface file */
 	struct dentry *dent_u;		/* Second text interface file */
-	int uses_dma;
 
 	/* Ref */
 	int nreaders;			/* Under mon_lock AND mbus->lock */
@@ -53,7 +52,7 @@ void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r);
 
 struct mon_bus *mon_bus_lookup(unsigned int num);
 
-int /*bool*/ mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus);
+int /*bool*/ mon_text_add(struct mon_bus *mbus, int busnum);
 void mon_text_del(struct mon_bus *mbus);
 // void mon_bin_add(struct mon_bus *);
 
@@ -82,4 +81,6 @@ extern struct mutex mon_lock;
 
 extern const struct file_operations mon_fops_stat;
 
+extern struct mon_bus mon_bus0;		/* Only for redundant checks */
+
 #endif /* __USB_MON_H */