linux/drivers/usb/gadget/mass_storage.c
Michal Nazarewicz 7f1ee82695 USB: mass_storage: eject LUNs on thread exit
Adds a fallback which forces all LUNs ejection (including
non-removable and with prevent_medium_removal flag) when mass storage
function (MSF) worker thread exits and gadget fails to handle the
situation.

Previously, if thread_exits was not specified mass storage function
(MSF) did nothing when exiting thread as it's unclear for *function*
what to do when it's thread terminates so responsibility of handling
this situation was left to the *gadget* using the function.

The g_mass_storage handled the situation by unregistering itself (the
same thing that file storage gadget does).  However, g_multi did
nothing and so MSF did not eject LUNs which prevented file system
unmounting.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-02 14:54:49 -08:00

247 lines
6.6 KiB
C

/*
* mass_storage.c -- Mass Storage USB Gadget
*
* Copyright (C) 2003-2008 Alan Stern
* Copyright (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* The Mass Storage Gadget acts as a USB Mass Storage device,
* appearing to the host as a disk drive or as a CD-ROM drive. In
* addition to providing an example of a genuinely useful gadget
* driver for a USB device, it also illustrates a technique of
* double-buffering for increased throughput. Last but not least, it
* gives an easy way to probe the behavior of the Mass Storage drivers
* in a USB host.
*
* Since this file serves only administrative purposes and all the
* business logic is implemented in f_mass_storage.* file. Read
* comments in this file for more detailed description.
*/
#include <linux/kernel.h>
#include <linux/utsname.h>
#include <linux/usb/ch9.h>
/*-------------------------------------------------------------------------*/
#define DRIVER_DESC "Mass Storage Gadget"
#define DRIVER_VERSION "2009/09/11"
/*-------------------------------------------------------------------------*/
/*
* kbuild is not very cooperative with respect to linking separately
* compiled library objects into one module. So for now we won't use
* separate compilation ... ensuring init/exit sections work to shrink
* the runtime footprint, and giving us at least some parts of what
* a "gcc --combine ... part1.c part2.c part3.c ... " build would.
*/
#include "composite.c"
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"
#include "f_mass_storage.c"
/*-------------------------------------------------------------------------*/
static struct usb_device_descriptor msg_device_desc = {
.bLength = sizeof msg_device_desc,
.bDescriptorType = USB_DT_DEVICE,
.bcdUSB = cpu_to_le16(0x0200),
.bDeviceClass = USB_CLASS_PER_INTERFACE,
/* Vendor and product id can be overridden by module parameters. */
.idVendor = cpu_to_le16(FSG_VENDOR_ID),
.idProduct = cpu_to_le16(FSG_PRODUCT_ID),
/* .bcdDevice = f(hardware) */
/* .iManufacturer = DYNAMIC */
/* .iProduct = DYNAMIC */
/* NO SERIAL NUMBER */
.bNumConfigurations = 1,
};
static struct usb_otg_descriptor otg_descriptor = {
.bLength = sizeof otg_descriptor,
.bDescriptorType = USB_DT_OTG,
/* REVISIT SRP-only hardware is possible, although
* it would not be called "OTG" ...
*/
.bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
};
static const struct usb_descriptor_header *otg_desc[] = {
(struct usb_descriptor_header *) &otg_descriptor,
NULL,
};
/* string IDs are assigned dynamically */
#define STRING_MANUFACTURER_IDX 0
#define STRING_PRODUCT_IDX 1
#define STRING_CONFIGURATION_IDX 2
static char manufacturer[50];
static struct usb_string strings_dev[] = {
[STRING_MANUFACTURER_IDX].s = manufacturer,
[STRING_PRODUCT_IDX].s = DRIVER_DESC,
[STRING_CONFIGURATION_IDX].s = "Self Powered",
{ } /* end of list */
};
static struct usb_gadget_strings stringtab_dev = {
.language = 0x0409, /* en-us */
.strings = strings_dev,
};
static struct usb_gadget_strings *dev_strings[] = {
&stringtab_dev,
NULL,
};
/****************************** Configurations ******************************/
static struct fsg_module_parameters mod_data = {
.stall = 1
};
FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
static unsigned long msg_registered = 0;
static void msg_cleanup(void);
static int msg_thread_exits(struct fsg_common *common)
{
msg_cleanup();
return 0;
}
static int __init msg_do_config(struct usb_configuration *c)
{
struct fsg_common *common;
struct fsg_config config;
int ret;
if (gadget_is_otg(c->cdev->gadget)) {
c->descriptors = otg_desc;
c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
}
fsg_config_from_params(&config, &mod_data);
config.thread_exits = msg_thread_exits;
common = fsg_common_init(0, c->cdev, &config);
if (IS_ERR(common))
return PTR_ERR(common);
ret = fsg_add(c->cdev, c, common);
fsg_common_put(common);
return ret;
}
static struct usb_configuration msg_config_driver = {
.label = "Linux File-Backed Storage",
.bind = msg_do_config,
.bConfigurationValue = 1,
/* .iConfiguration = DYNAMIC */
.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
};
/****************************** Gadget Bind ******************************/
static int __init msg_bind(struct usb_composite_dev *cdev)
{
struct usb_gadget *gadget = cdev->gadget;
int status;
/* Allocate string descriptor numbers ... note that string
* contents can be overridden by the composite_dev glue.
*/
/* device descriptor strings: manufacturer, product */
snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
init_utsname()->sysname, init_utsname()->release,
gadget->name);
status = usb_string_id(cdev);
if (status < 0)
return status;
strings_dev[STRING_MANUFACTURER_IDX].id = status;
msg_device_desc.iManufacturer = status;
status = usb_string_id(cdev);
if (status < 0)
return status;
strings_dev[STRING_PRODUCT_IDX].id = status;
msg_device_desc.iProduct = status;
status = usb_string_id(cdev);
if (status < 0)
return status;
strings_dev[STRING_CONFIGURATION_IDX].id = status;
msg_config_driver.iConfiguration = status;
/* register our second configuration */
status = usb_add_config(cdev, &msg_config_driver);
if (status < 0)
return status;
dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
set_bit(0, &msg_registered);
return 0;
}
/****************************** Some noise ******************************/
static struct usb_composite_driver msg_driver = {
.name = "g_mass_storage",
.dev = &msg_device_desc,
.strings = dev_strings,
.bind = msg_bind,
};
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Michal Nazarewicz");
MODULE_LICENSE("GPL");
static int __init msg_init(void)
{
return usb_composite_register(&msg_driver);
}
module_init(msg_init);
static void msg_cleanup(void)
{
if (test_and_clear_bit(0, &msg_registered))
usb_composite_unregister(&msg_driver);
}
module_exit(msg_cleanup);