USB: core: Remove usbfs_mutex

Commit 4a2a8a2cce86 ("usbfs: private mutex for open, release, and
remove") is now obsolete.  The commit was created back when we had
to handle both usbfs device nodes and the old usbdevfs filesystem
(/proc/bus/usb/), but usbdevfs no longer exists.

This means there's no longer any need to hold a mutex during two
separate removal operations (and thus during an entire notifier chain
call).  Furthermore, the one remaining remove/release pair doesn't
race with open thanks to the synchronization provided by the device
model core in bus_find_device().  Remove and release don't race with
each other because they both run with the device lock held.

The upshot is that usbfs_mutex isn't needed any more.  This patch
removes it entirely.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index d95a5358f73d..bd8d01f85a13 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -169,7 +169,6 @@ extern const struct attribute_group *usb_device_groups[];
 extern const struct attribute_group *usb_interface_groups[];
 
 /* usbfs stuff */
-extern struct mutex usbfs_mutex;
 extern struct usb_driver usbfs_driver;
 extern const struct file_operations usbfs_devices_fops;
 extern const struct file_operations usbdev_file_operations;