3268 lines
94 KiB
C
Executable File
3268 lines
94 KiB
C
Executable File
/*
|
||
*
|
||
* Copyright (c) 2003 The Regents of the University of California. All
|
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* rights reserved.
|
||
*
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||
* Redistribution and use in source and binary forms, with or without
|
||
* modification, are permitted provided that the following conditions
|
||
* are met:
|
||
*
|
||
* - Redistributions of source code must retain the above copyright
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||
* notice, this list of conditions and the following disclaimer.
|
||
*
|
||
* - Neither the name of the University nor the names of its
|
||
* contributors may be used to endorse or promote products derived
|
||
* from this software without specific prior written permission.
|
||
*
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||
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
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||
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
||
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
|
||
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
|
||
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
||
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
||
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
|
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* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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||
*/
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||
|
||
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/*
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||
* FUSD: the Framework for User-Space Devices
|
||
*
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||
* Linux Kernel Module
|
||
*
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||
* Jeremy Elson <jelson@circlemud.org>
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* Copyright (c) 2001, Sensoria Corporation
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* Copyright (c) 2002-2003, Regents of the University of California
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* Copyright (c) 2007 Monty and Xiph.Org
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*
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* $Id$
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||
*/
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||
|
||
/*
|
||
* Note on debugging messages: Unexpected errors (i.e., indicators of
|
||
* bugs in this kernel module) should always contain '!'. Expected
|
||
* conditions, even if exceptional (e.g., the device-driver-provider
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||
* disappears while a file is waiting for a return from a system call)
|
||
* must NOT contain '!'.
|
||
*/
|
||
|
||
#ifndef __KERNEL__
|
||
# define __KERNEL__
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||
#endif
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||
|
||
#ifdef MODVERSIONS
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||
# include <linux/modversions.h>
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||
#endif
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||
|
||
//#include <linux/config.h>
|
||
#include <linux/stddef.h>
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||
#include <linux/kernel.h>
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||
#include <linux/module.h>
|
||
#include <linux/list.h>
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||
#include <linux/init.h>
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||
#include <linux/fs.h>
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||
#include <linux/mm.h>
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||
#include <linux/slab.h>
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||
#include <linux/vmalloc.h>
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||
//#include <linux/devfs_fs_kernel.h>
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||
#include <linux/poll.h>
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#include <linux/version.h>
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||
#include <linux/major.h>
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||
#include <linux/uio.h>
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||
#include <linux/cdev.h>
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||
#include <linux/device.h>
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||
#include <linux/highmem.h>
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||
|
||
#include <asm/atomic.h>
|
||
#include <asm/uaccess.h>
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||
#include <asm/ioctl.h>
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||
#include <asm/pgtable.h>
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||
#include <asm/pgalloc.h>
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||
|
||
#define STATIC
|
||
|
||
/* Define this if you want to emit debug messages (adds ~8K) */
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||
#define CONFIG_FUSD_DEBUG
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||
|
||
/* Default debug level for FUSD messages. Has no effect unless
|
||
* CONFIG_FUSD_DEBUG is defined. */
|
||
#ifndef CONFIG_FUSD_DEBUGLEVEL
|
||
# define CONFIG_FUSD_DEBUGLEVEL 4
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||
#endif
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||
|
||
/* Define this to check for memory leaks */
|
||
/*#define CONFIG_FUSD_MEMDEBUG*/
|
||
|
||
/* Define this to use the faster wake_up_interruptible_sync instead of
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||
* the normal wake_up_interruptible. Note: you can't do this unless
|
||
* you're bulding fusd as part of the kernel (not a module); or you've
|
||
* patched kernel/ksyms.s to add __wake_up_sync in addition to
|
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* __wake_up. */
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/* #define CONFIG_FUSD_USE_WAKEUPSYNC */
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||
|
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
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|
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# define CLASS class_simple
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||
# define class_create class_simple_create
|
||
# define class_destroy class_simple_destroy
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||
# define CLASS_DEVICE_CREATE(a, b, c, d, e) class_simple_device_add(a, c, d, e)
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||
# define CLASS_DEVICE_DESTROY(a, b) class_simple_device_remove(b)
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||
|
||
#else
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||
|
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# define CLASS class
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||
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# if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)
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||
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||
# define CLASS_DEVICE_CREATE(a, b, c, d, e) device_create(a, c, d, e)
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||
|
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# else
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||
|
||
# if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,30)
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||
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# define CLASS_DEVICE_CREATE(a, b, c, d, e) device_create(a, b, c, d, e)
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||
|
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# else
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||
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# define CLASS_DEVICE_CREATE(a, b, c, d, e) device_create(a, b, c, d, e)
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||
|
||
# endif
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||
|
||
# endif
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||
|
||
#endif
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||
|
||
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,30)
|
||
|
||
# define CLASS_DEVICE_DESTROY(a, b) device_destroy(a, b)
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||
|
||
#else
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||
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# define CLASS_DEVICE_DESTROY(a, b) device_destroy(a, b)
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||
|
||
#endif
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||
|
||
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,19)
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||
|
||
struct sysfs_elem_dir
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||
{
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||
struct kobject *kobj;
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||
/* children list starts here and goes through sd->s_sibling */
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||
struct sysfs_dirent *children;
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||
};
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||
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struct sysfs_elem_symlink
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||
{
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||
struct sysfs_dirent *target_sd;
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||
};
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||
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||
struct sysfs_elem_attr
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||
{
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||
struct attribute *attr;
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||
struct sysfs_open_dirent *open;
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||
};
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||
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||
struct sysfs_elem_bin_attr
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||
{
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||
struct bin_attribute *bin_attr;
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||
struct hlist_head buffers;
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||
};
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||
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||
struct sysfs_dirent
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||
{
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||
atomic_t s_count;
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||
atomic_t s_active;
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||
struct sysfs_dirent *s_parent;
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||
struct sysfs_dirent *s_sibling;
|
||
const char *s_name;
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||
|
||
union
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||
{
|
||
struct sysfs_elem_dir s_dir;
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||
struct sysfs_elem_symlink s_symlink;
|
||
struct sysfs_elem_attr s_attr;
|
||
struct sysfs_elem_bin_attr s_bin_attr;
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||
};
|
||
|
||
unsigned int s_flags;
|
||
ino_t s_ino;
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||
umode_t s_mode;
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||
struct sysfs_inode_attrs *s_iattr;
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||
};
|
||
|
||
struct class_private {
|
||
struct kset class_subsys;
|
||
struct klist class_devices;
|
||
struct list_head class_interfaces;
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||
struct kset class_dirs;
|
||
struct mutex class_mutex;
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||
struct class *class;
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||
};
|
||
|
||
#define to_class(obj) \
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container_of(obj, struct class_private, class_subsys.kobj)
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||
|
||
#endif
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||
|
||
static inline struct kobject * to_kobj (struct dentry * dentry)
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||
{
|
||
struct sysfs_dirent * sd = dentry->d_fsdata;
|
||
if ( sd )
|
||
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
|
||
return ((struct kobject *) sd->s_element );
|
||
#else
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||
return ((struct kobject *) sd->s_dir.kobj );
|
||
#endif
|
||
else
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||
return NULL;
|
||
}
|
||
|
||
//#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
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||
|
||
/**************************************************************************/
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||
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||
#include "fusd.h"
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#include "fusd_msg.h"
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#include "kfusd.h"
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||
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||
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
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||
# error "***FUSD doesn't work before Linux Kernel v2.6.13"
|
||
#endif
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||
|
||
STATIC struct cdev* fusd_control_cdev;
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||
STATIC struct cdev* fusd_status_cdev;
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||
|
||
STATIC dev_t control_id;
|
||
STATIC dev_t status_id;
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||
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||
static struct CLASS *fusd_class;
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||
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||
static struct device *fusd_control_device;
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||
static struct device *fusd_status_device;
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||
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||
extern struct CLASS *sound_class;
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||
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||
/* version number incremented for each registered device */
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||
STATIC int last_version = 1;
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||
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||
/* version number incremented for each transaction to userspace */
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||
STATIC int last_transid = 1;
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||
|
||
/* wait queue that is awakened when new devices are registered */
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||
STATIC DECLARE_WAIT_QUEUE_HEAD (new_device_wait);
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||
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||
/* the list of valid devices, and sem to protect it */
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||
LIST_HEAD (fusd_devlist_head);
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||
DECLARE_MUTEX (fusd_devlist_sem);
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||
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||
//#ifdef MODULE_LICENSE
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||
MODULE_AUTHOR ("Jeremy Elson <jelson@acm.org> (c)2001");
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||
MODULE_LICENSE ("GPL");
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||
//#endif
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||
|
||
/***************************Debugging Support*****************************/
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||
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||
#ifdef CONFIG_FUSD_DEBUG
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||
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STATIC int fusd_debug_level = CONFIG_FUSD_DEBUGLEVEL;
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module_param (fusd_debug_level, int, S_IRUGO);
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||
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||
# define BUFSIZE 1000 /* kernel's kmalloc pool has a 1012-sized bucket */
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||
static int debug_throttle = 0; /* emit a maximum number of debug
|
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messages, else it's possible to take
|
||
out the machine accidentally if a
|
||
daemon disappears with open files */
|
||
|
||
STATIC void rdebug_real (char *fmt, ...)
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||
{
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||
va_list ap;
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||
int len;
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||
char *message;
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||
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||
if ( debug_throttle > 100 ) return;
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||
debug_throttle++;
|
||
|
||
/* I'm kmallocing since you don't really want 1k on the stack. I've
|
||
* had stack overflow problems before; the kernel stack is quite
|
||
* small... */
|
||
if ( ( message = KMALLOC(BUFSIZE, GFP_KERNEL) ) == NULL )
|
||
return;
|
||
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||
va_start(ap, fmt);
|
||
len = vsnprintf(message, BUFSIZE - 1, fmt, ap);
|
||
va_end(ap);
|
||
|
||
if ( len >= BUFSIZE )
|
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{
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printk("WARNING: POSSIBLE KERNEL CORRUPTION; MESSAGE TOO LONG\n");
|
||
}
|
||
else
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||
{
|
||
printk("fusd: %.975s\n", message); /* note msgs are truncated at
|
||
* ~1000 chars to fit inside the 1024 printk
|
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* limit imposed by the kernel */
|
||
}
|
||
|
||
KFREE(message);
|
||
}
|
||
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||
#endif /* CONFIG_FUSD_DEBUG */
|
||
|
||
/******************** Memory Debugging ************************************/
|
||
|
||
#ifdef CONFIG_FUSD_MEMDEBUG
|
||
|
||
# define MAX_MEM_DEBUG 10000
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||
|
||
DECLARE_MUTEX (fusd_memdebug_sem);
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||
|
||
typedef struct
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||
{
|
||
void *ptr;
|
||
int line;
|
||
int size;
|
||
} mem_debug_t;
|
||
|
||
mem_debug_t *mem_debug;
|
||
|
||
STATIC int fusd_mem_init (void)
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||
{
|
||
int i;
|
||
|
||
mem_debug = kmalloc(sizeof (mem_debug_t ) * MAX_MEM_DEBUG, GFP_KERNEL);
|
||
|
||
if ( mem_debug == NULL )
|
||
{
|
||
RDEBUG(2, "argh - memdebug malloc failed!");
|
||
return -ENOMEM;
|
||
}
|
||
|
||
/* initialize */
|
||
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
|
||
mem_debug[i].ptr = NULL;
|
||
|
||
RDEBUG(2, "FUSD memory debugger activated");
|
||
return 0;
|
||
}
|
||
|
||
STATIC void fusd_mem_cleanup (void)
|
||
{
|
||
int i;
|
||
int count = 0;
|
||
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
|
||
if ( mem_debug[i].ptr != NULL )
|
||
{
|
||
RDEBUG(0, "memdebug: failed to free memory allocated at line %d (%d b)",
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||
mem_debug[i].line, mem_debug[i].size);
|
||
count++;
|
||
}
|
||
if ( !count )
|
||
RDEBUG(2, "congratulations - memory debugger is happy!");
|
||
kfree(mem_debug);
|
||
}
|
||
|
||
STATIC void fusd_mem_add (void *ptr, int line, int size)
|
||
{
|
||
int i;
|
||
|
||
if ( ptr == NULL )
|
||
return;
|
||
|
||
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
|
||
{
|
||
if ( mem_debug[i].ptr == NULL )
|
||
{
|
||
mem_debug[i].ptr = ptr;
|
||
mem_debug[i].line = line;
|
||
mem_debug[i].size = size;
|
||
return;
|
||
}
|
||
}
|
||
RDEBUG(1, "WARNING - memdebug out of space!!!!");
|
||
}
|
||
|
||
STATIC void fusd_mem_del (void *ptr)
|
||
{
|
||
int i;
|
||
for ( i = 0; i < MAX_MEM_DEBUG; i++ )
|
||
{
|
||
if ( mem_debug[i].ptr == ptr )
|
||
{
|
||
mem_debug[i].ptr = NULL;
|
||
return;
|
||
}
|
||
}
|
||
RDEBUG(2, "WARNING - memdebug is confused!!!!");
|
||
}
|
||
|
||
STATIC void *fusd_kmalloc (size_t size, int type, int line)
|
||
{
|
||
void *ptr = kmalloc(size, type);
|
||
down(&fusd_memdebug_sem);
|
||
fusd_mem_add(ptr, line, size);
|
||
up(&fusd_memdebug_sem);
|
||
return ptr;
|
||
}
|
||
|
||
STATIC void fusd_kfree (void *ptr)
|
||
{
|
||
down(&fusd_memdebug_sem);
|
||
fusd_mem_del(ptr);
|
||
kfree(ptr);
|
||
up(&fusd_memdebug_sem);
|
||
}
|
||
|
||
STATIC void *fusd_vmalloc (size_t size, int line)
|
||
{
|
||
void *ptr = vmalloc(size);
|
||
down(&fusd_memdebug_sem);
|
||
fusd_mem_add(ptr, line, size);
|
||
up(&fusd_memdebug_sem);
|
||
return ptr;
|
||
}
|
||
|
||
STATIC void fusd_vfree (void *ptr)
|
||
{
|
||
down(&fusd_memdebug_sem);
|
||
fusd_mem_del(ptr);
|
||
vfree(ptr);
|
||
up(&fusd_memdebug_sem);
|
||
}
|
||
|
||
#endif /* CONFIG_FUSD_MEMDEBUG */
|
||
|
||
|
||
/********************* FUSD Device List ***************************/
|
||
|
||
|
||
|
||
/*************************************************************************/
|
||
/************** STATE MANAGEMENT AND BOOKKEEPING UTILITIES ***************/
|
||
/*************************************************************************/
|
||
|
||
STATIC inline void init_fusd_msg (fusd_msg_t *fusd_msg)
|
||
{
|
||
if ( fusd_msg == NULL )
|
||
return;
|
||
|
||
memset(fusd_msg, 0, sizeof (fusd_msg_t ));
|
||
fusd_msg->magic = FUSD_MSG_MAGIC;
|
||
fusd_msg->cmd = FUSD_FOPS_CALL; /* typical, but can be overwritten */
|
||
}
|
||
|
||
/*
|
||
* free a fusd_msg, and NULL out the pointer that points to that fusd_msg.
|
||
*/
|
||
STATIC inline void free_fusd_msg (fusd_msg_t **fusd_msg)
|
||
{
|
||
if ( fusd_msg == NULL || *fusd_msg == NULL )
|
||
return;
|
||
|
||
if ( ( *fusd_msg )->data != NULL )
|
||
{
|
||
VFREE(( *fusd_msg )->data);
|
||
( *fusd_msg )->data = NULL;
|
||
}
|
||
KFREE(*fusd_msg);
|
||
*fusd_msg = NULL;
|
||
}
|
||
|
||
/* adjust the size of the 'files' array attached to the device to
|
||
* better match the number of files. In all cases, size must be at
|
||
* least MIN_ARRAY_SIZE. Subject to that constraint: if
|
||
* num_files==array_size, the size is doubled; if
|
||
* num_files<array_size/4, the size is halved. Array is kept as is if
|
||
* the malloc fails. Returns a pointer to the new file struct or NULL
|
||
* if there isn't one. */
|
||
STATIC fusd_file_t **fusd_dev_adjsize (fusd_dev_t *fusd_dev)
|
||
{
|
||
fusd_file_t **old_array;
|
||
int old_size;
|
||
|
||
old_array = fusd_dev->files;
|
||
old_size = fusd_dev->array_size;
|
||
|
||
/* compute the new size of the array */
|
||
if ( fusd_dev->array_size > 4 * fusd_dev->num_files )
|
||
fusd_dev->array_size /= 2;
|
||
else if ( fusd_dev->array_size == fusd_dev->num_files )
|
||
fusd_dev->array_size *= 2;
|
||
|
||
/* respect the minimums and maximums (policy) */
|
||
if ( fusd_dev->array_size < MIN_FILEARRAY_SIZE )
|
||
fusd_dev->array_size = MIN_FILEARRAY_SIZE;
|
||
if ( fusd_dev->array_size > MAX_FILEARRAY_SIZE )
|
||
fusd_dev->array_size = MAX_FILEARRAY_SIZE;
|
||
|
||
/* make sure it's sane */
|
||
if ( fusd_dev->array_size < fusd_dev->num_files )
|
||
{
|
||
RDEBUG(0, "fusd_dev_adjsize is royally screwed up!!!!!");
|
||
return fusd_dev->files;
|
||
}
|
||
|
||
/* create a new array. if successful, copy the contents of the old
|
||
* one. if not, revert back to the old. */
|
||
fusd_dev->files = KMALLOC(fusd_dev->array_size * sizeof (fusd_file_t * ),
|
||
GFP_KERNEL);
|
||
if ( fusd_dev->files == NULL )
|
||
{
|
||
RDEBUG(1, "malloc failed in fusd_dev_adjsize!");
|
||
fusd_dev->files = old_array;
|
||
fusd_dev->array_size = old_size;
|
||
}
|
||
else
|
||
{
|
||
RDEBUG(10, "/dev/%s now has space for %d files (had %d)", NAME(fusd_dev),
|
||
fusd_dev->array_size, old_size);
|
||
memset(fusd_dev->files, 0, fusd_dev->array_size * sizeof (fusd_file_t * ));
|
||
memcpy(fusd_dev->files, old_array,
|
||
fusd_dev->num_files * sizeof (fusd_file_t * ));
|
||
KFREE(old_array);
|
||
}
|
||
|
||
return fusd_dev->files;
|
||
}
|
||
|
||
/*
|
||
* DEVICE LOCK MUST BE HELD TO CALL THIS FUNCTION
|
||
*
|
||
* This function frees a device IF there is nothing left that is
|
||
* referencing it.
|
||
*
|
||
* Specifically, we do not free the device if:
|
||
* - The driver is still active (i.e. device is not a zombie)
|
||
* - There are still files with the device open
|
||
* - There is an open in progress, i.e. a client has verified that
|
||
* this is a valid device and is getting ready to add itself as an
|
||
* open file.
|
||
*
|
||
* If the device is safe to free, it is removed from the valid list
|
||
* (in verysafe mode only) and freed.
|
||
*
|
||
* Returns: 1 if the device was freed
|
||
* 0 if the device still exists (and can be unlocked) */
|
||
STATIC int maybe_free_fusd_dev (fusd_dev_t *fusd_dev)
|
||
{
|
||
fusd_msgC_t *ptr, *next;
|
||
|
||
down(&fusd_devlist_sem);
|
||
|
||
/* DON'T free the device under conditions listed above */
|
||
if ( !fusd_dev->zombie || fusd_dev->num_files || fusd_dev->open_in_progress )
|
||
{
|
||
up(&fusd_devlist_sem);
|
||
return 0;
|
||
}
|
||
|
||
/* OK - bombs away! This fusd_dev_t is on its way out the door! */
|
||
|
||
RDEBUG(8, "freeing state associated with /dev/%s", NAME(fusd_dev));
|
||
|
||
/* delete it off the list of valid devices, and unlock */
|
||
list_del(&fusd_dev->devlist);
|
||
up(&fusd_devlist_sem);
|
||
|
||
/* free any outgoing messages that the device might have waiting */
|
||
for ( ptr = fusd_dev->msg_head; ptr != NULL; ptr = next )
|
||
{
|
||
next = ptr->next;
|
||
FREE_FUSD_MSGC(ptr);
|
||
}
|
||
|
||
/* free the device's dev name */
|
||
if ( fusd_dev->dev_name != NULL )
|
||
{
|
||
KFREE(fusd_dev->dev_name);
|
||
fusd_dev->dev_name = NULL;
|
||
}
|
||
|
||
/* free the device's class name */
|
||
if ( fusd_dev->class_name != NULL )
|
||
{
|
||
KFREE(fusd_dev->class_name);
|
||
fusd_dev->class_name = NULL;
|
||
}
|
||
|
||
/* free the device's name */
|
||
if ( fusd_dev->name != NULL )
|
||
{
|
||
KFREE(fusd_dev->name);
|
||
fusd_dev->name = NULL;
|
||
}
|
||
|
||
|
||
/* free the array used to store pointers to fusd_file_t's */
|
||
if ( fusd_dev->files != NULL )
|
||
{
|
||
KFREE(fusd_dev->files);
|
||
fusd_dev->files = NULL;
|
||
}
|
||
|
||
/* clear the structure and free it! */
|
||
memset(fusd_dev, 0, sizeof (fusd_dev_t ));
|
||
KFREE(fusd_dev);
|
||
|
||
/* notify fusd_status readers that there has been a change in the
|
||
* list of registered devices */
|
||
atomic_inc_and_ret(&last_version);
|
||
wake_up_interruptible(&new_device_wait);
|
||
|
||
//MOD_DEC_USE_COUNT;
|
||
return 1;
|
||
}
|
||
|
||
/*
|
||
*
|
||
* DO NOT CALL THIS FUNCTION UNLESS THE DEVICE IS ALREADY LOCKED
|
||
*
|
||
* zombify_device: called when the driver disappears. Indicates that
|
||
* the driver is no longer available to service requests. If there
|
||
* are no outstanding system calls waiting for the fusd_dev state, the
|
||
* device state itself is freed.
|
||
*
|
||
*/
|
||
STATIC void zombify_dev (fusd_dev_t *fusd_dev)
|
||
{
|
||
int i;
|
||
|
||
if ( fusd_dev->zombie )
|
||
{
|
||
RDEBUG(1, "zombify_device called on a zombie!!");
|
||
return;
|
||
}
|
||
|
||
fusd_dev->zombie = 1;
|
||
|
||
RDEBUG(3, "/dev/%s turning into a zombie (%d open files)", NAME(fusd_dev),
|
||
fusd_dev->num_files);
|
||
|
||
/* If there are files holding this device open, wake them up. */
|
||
for ( i = 0; i < fusd_dev->num_files; i++ )
|
||
{
|
||
wake_up_interruptible(&fusd_dev->files[i]->file_wait);
|
||
wake_up_interruptible(&fusd_dev->files[i]->poll_wait);
|
||
}
|
||
}
|
||
|
||
/* utility function to find the index of a fusd_file in a fusd_dev.
|
||
* returns index if found, -1 if not found. ASSUMES WE HAVE A VALID
|
||
* fusd_dev. fusd_file may be NULL if we are searching for an empty
|
||
* slot. */
|
||
STATIC int find_fusd_file (fusd_dev_t *fusd_dev, fusd_file_t *fusd_file)
|
||
{
|
||
int i, num_files = fusd_dev->num_files;
|
||
fusd_file_t **files = fusd_dev->files;
|
||
|
||
for ( i = 0; i < num_files; i++ )
|
||
if ( files[i] == fusd_file )
|
||
return i;
|
||
|
||
return -1;
|
||
}
|
||
|
||
/*
|
||
* DEVICE LOCK MUST BE HELD BEFORE THIS IS CALLED
|
||
*
|
||
* Returns 1 if the device was also freed. 0 if only the file was
|
||
* freed. If the device is freed, then do not try to unlock it!
|
||
* (Callers: Check the return value before unlocking!)
|
||
*/
|
||
STATIC int free_fusd_file (fusd_dev_t *fusd_dev, fusd_file_t *fusd_file)
|
||
{
|
||
int i;
|
||
struct list_head *tmp, *it;
|
||
|
||
/* find the index of the file in the device's file-list... */
|
||
if ( ( i = find_fusd_file(fusd_dev, fusd_file) ) < 0 )
|
||
panic("corrupted fusd_dev: releasing a file that we think is closed");
|
||
|
||
/* ...and remove it (by putting the last entry into its place) */
|
||
fusd_dev->files[i] = fusd_dev->files[--( fusd_dev->num_files )];
|
||
|
||
/* there might be an incoming message waiting for a restarted system
|
||
* call. free it -- after possibly forging a close (see
|
||
* fusd_forge_close). */
|
||
|
||
|
||
list_for_each_safe(it, tmp, &fusd_file->transactions)
|
||
{
|
||
struct fusd_transaction* transaction = list_entry(it, struct fusd_transaction, list);
|
||
if ( transaction->msg_in )
|
||
{
|
||
if ( transaction->msg_in->subcmd == FUSD_OPEN && transaction->msg_in->parm.fops_msg.retval == 0 )
|
||
fusd_forge_close(transaction->msg_in, fusd_dev);
|
||
free_fusd_msg(&transaction->msg_in);
|
||
}
|
||
KFREE(transaction);
|
||
}
|
||
|
||
/* free state associated with this file */
|
||
memset(fusd_file, 0, sizeof (fusd_file_t ));
|
||
KFREE(fusd_file);
|
||
|
||
/* reduce the size of the file array if necessary */
|
||
if ( fusd_dev->array_size > MIN_FILEARRAY_SIZE &&
|
||
fusd_dev->array_size > 4 * fusd_dev->num_files )
|
||
fusd_dev_adjsize(fusd_dev);
|
||
|
||
/* renumber the array */
|
||
for ( i = 0; i < fusd_dev->num_files; i++ )
|
||
fusd_dev->files[i]->index = i;
|
||
|
||
/* try to free the device -- this may have been its last file */
|
||
return maybe_free_fusd_dev(fusd_dev);
|
||
}
|
||
|
||
|
||
/****************************************************************************/
|
||
/********************** CLIENT CALLBACK FUNCTIONS ***************************/
|
||
/****************************************************************************/
|
||
|
||
/* todo
|
||
* fusd_restart_check: Called from the beginning of most system calls
|
||
* to see if we are restarting a system call.
|
||
*
|
||
* In the common case -- that this is NOT a restarted syscall -- we
|
||
* return 0.
|
||
*
|
||
* In the much less common case, we return ERESTARTSYS, and expect the
|
||
* caller to jump right to its fusd_fops_call() call.
|
||
*
|
||
* In the even LESS (hopefully very rare) case when one PID had an
|
||
* interrupted syscall, but a different PID is the next to do a system
|
||
* call on that file descriptor -- well, we lose. Clear state of that
|
||
* old syscall out and continue as usual.
|
||
*/
|
||
STATIC struct fusd_transaction* fusd_find_incomplete_transaction (fusd_file_t *fusd_file, int subcmd)
|
||
{
|
||
struct fusd_transaction* transaction = fusd_find_transaction_by_pid(fusd_file, current->pid);
|
||
if ( transaction == NULL )
|
||
return NULL;
|
||
|
||
|
||
if ( transaction->subcmd != subcmd )
|
||
{
|
||
RDEBUG(2, "Incomplete transaction %ld thrown out, was expecting subcmd %d but received %d",
|
||
transaction->transid, transaction->subcmd, subcmd);
|
||
fusd_cleanup_transaction(fusd_file, transaction);
|
||
return NULL;
|
||
}
|
||
|
||
RDEBUG(4, "pid %d restarting system call with transid %ld", current->pid,
|
||
transaction->transid);
|
||
return transaction;
|
||
}
|
||
|
||
STATIC int send_to_dev (fusd_dev_t *fusd_dev, fusd_msg_t *fusd_msg, int locked)
|
||
{
|
||
fusd_msgC_t *fusd_msgC;
|
||
|
||
/* allocate a container for the message */
|
||
if ( ( fusd_msgC = KMALLOC(sizeof (fusd_msgC_t ), GFP_KERNEL) ) == NULL )
|
||
return -ENOMEM;
|
||
|
||
memset(fusd_msgC, 0, sizeof (fusd_msgC_t ));
|
||
memcpy(&fusd_msgC->fusd_msg, fusd_msg, sizeof (fusd_msg_t ));
|
||
|
||
if ( !locked )
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* put the message in the device's outgoing queue. */
|
||
if ( fusd_dev->msg_head == NULL )
|
||
{
|
||
fusd_dev->msg_head = fusd_dev->msg_tail = fusd_msgC;
|
||
}
|
||
else
|
||
{
|
||
fusd_dev->msg_tail->next = fusd_msgC;
|
||
fusd_dev->msg_tail = fusd_msgC;
|
||
}
|
||
|
||
if ( !locked )
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* wake up the driver, which now has a message waiting in its queue */
|
||
WAKE_UP_INTERRUPTIBLE_SYNC(&fusd_dev->dev_wait);
|
||
|
||
return 0;
|
||
|
||
zombie_dev:
|
||
KFREE(fusd_msgC);
|
||
return -EPIPE;
|
||
}
|
||
|
||
/*
|
||
* special case: if the driver sent back a successful "open", but
|
||
* there is no file that is actually open, we forge a "close" so that
|
||
* the driver can maintain balanced open/close pairs. We put calls to
|
||
* this in fusd_fops_reply, when the reply first comes in; and,
|
||
* free_fusd_file, when we throw away a reply that had been
|
||
* pending for a restart.
|
||
*/
|
||
STATIC void fusd_forge_close (fusd_msg_t *msg, fusd_dev_t *fusd_dev)
|
||
{
|
||
RDEBUG(2, "/dev/%s tried to complete an open for transid %ld, "
|
||
"forging a close", NAME(fusd_dev), msg->parm.fops_msg.transid);
|
||
msg->cmd = FUSD_FOPS_CALL_DROPREPLY;
|
||
msg->subcmd = FUSD_CLOSE;
|
||
msg->parm.fops_msg.transid = atomic_inc_and_ret(&last_transid);
|
||
send_to_dev(fusd_dev, msg, 1);
|
||
}
|
||
|
||
/*
|
||
* fusd_fops_call_send: send a fusd_msg into userspace.
|
||
*
|
||
* NOTE - we are already holding the lock on fusd_file_arg when this
|
||
* function is called, but NOT the lock on the fusd_dev
|
||
*/
|
||
STATIC int fusd_fops_call_send (fusd_file_t *fusd_file_arg,
|
||
fusd_msg_t *fusd_msg, struct fusd_transaction** transaction)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
|
||
/* I check this just in case, shouldn't be necessary. */
|
||
GET_FUSD_FILE_AND_DEV(fusd_file_arg, fusd_file, fusd_dev);
|
||
|
||
/* make sure message is sane */
|
||
if ( ( fusd_msg->data == NULL ) != ( fusd_msg->datalen == 0 ) )
|
||
{
|
||
RDEBUG(2, "fusd_fops_call: data pointer and datalen mismatch");
|
||
return -EINVAL;
|
||
}
|
||
|
||
/* fill the rest of the structure */
|
||
fusd_msg->parm.fops_msg.pid = current->pid;
|
||
// fusd_msg->parm.fops_msg.uid = current_uid();
|
||
// fusd_msg->parm.fops_msg.gid = current_gid();
|
||
fusd_msg->parm.fops_msg.flags = fusd_file->file->f_flags;
|
||
fusd_msg->parm.fops_msg.offset = fusd_file->file->f_pos;
|
||
fusd_msg->parm.fops_msg.device_info = fusd_dev->private_data;
|
||
fusd_msg->parm.fops_msg.private_info = fusd_file->private_data;
|
||
fusd_msg->parm.fops_msg.fusd_file = fusd_file;
|
||
fusd_msg->parm.fops_msg.transid = atomic_inc_and_ret(&last_transid);
|
||
|
||
/* set up certain state depending on if we expect a reply */
|
||
switch ( fusd_msg->cmd )
|
||
{
|
||
|
||
case FUSD_FOPS_CALL: /* common case */
|
||
fusd_msg->parm.fops_msg.hint = fusd_file->index;
|
||
|
||
break;
|
||
|
||
case FUSD_FOPS_CALL_DROPREPLY:
|
||
/* nothing needed */
|
||
break;
|
||
|
||
case FUSD_FOPS_NONBLOCK:
|
||
fusd_msg->parm.fops_msg.hint = fusd_file->index;
|
||
break;
|
||
|
||
default:
|
||
RDEBUG(0, "whoa - fusd_fops_call_send got msg with unknown cmd!");
|
||
break;
|
||
}
|
||
|
||
if ( transaction != NULL )
|
||
{
|
||
int retval;
|
||
retval = fusd_add_transaction(fusd_file, fusd_msg->parm.fops_msg.transid, fusd_msg->subcmd,
|
||
fusd_msg->parm.fops_msg.length, transaction);
|
||
if ( retval < 0 )
|
||
return retval;
|
||
}
|
||
|
||
/* now add the message to the device's outgoing queue! */
|
||
return send_to_dev(fusd_dev, fusd_msg, 0);
|
||
|
||
|
||
/* bizarre errors go straight here */
|
||
invalid_dev:
|
||
invalid_file :
|
||
RDEBUG(0, "fusd_fops_call: got invalid device or file!!!!");
|
||
return -EPIPE;
|
||
}
|
||
|
||
/*
|
||
* fusd_fops_call_wait: wait for a driver to reply to a message
|
||
*
|
||
* NOTE - we are already holding the lock on fusd_file_arg when this
|
||
* function is called, but NOT the lock on the fusd_dev
|
||
*/
|
||
STATIC int fusd_fops_call_wait (fusd_file_t *fusd_file_arg,
|
||
fusd_msg_t **fusd_msg_reply, struct fusd_transaction* transaction)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
int retval;
|
||
|
||
/* I check this just in case, shouldn't be necessary. */
|
||
GET_FUSD_FILE_AND_DEV(fusd_file_arg, fusd_file, fusd_dev);
|
||
|
||
/* initialize first to tell callers there is no reply (yet) */
|
||
if ( fusd_msg_reply != NULL )
|
||
*fusd_msg_reply = NULL;
|
||
|
||
/*
|
||
* Now, lock the device, check for an incoming message, and sleep if
|
||
* there is not a message already waiting for us. Note that we are
|
||
* unrolling the interruptible_sleep_on, as in the kernel's
|
||
* fs/pipe.c, to avoid race conditions between checking for the
|
||
* sleep condition and sleeping.
|
||
*/
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
while ( transaction->msg_in == NULL )
|
||
{
|
||
DECLARE_WAITQUEUE(wait, current);
|
||
|
||
RDEBUG(10, "pid %d blocking on transid %ld", current->pid, transaction->transid);
|
||
current->state = TASK_INTERRUPTIBLE;
|
||
add_wait_queue(&fusd_file->file_wait, &wait);
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
|
||
schedule();
|
||
remove_wait_queue(&fusd_file->file_wait, &wait);
|
||
current->state = TASK_RUNNING;
|
||
|
||
/*
|
||
* If we woke up due to a signal -- and not due to a reply message
|
||
* coming in -- then we are in some trouble. The driver is already
|
||
* processing the request and might have changed some state that is
|
||
* hard to roll back. So, we'll tell the process to restart the
|
||
* system call, and come back to this point when the system call is
|
||
* restarted. We need to remember the PID to avoid confusion in
|
||
* case there is another process holding this file descriptor that
|
||
* is also trying to make a call.
|
||
*/
|
||
if ( signal_pending(current) )
|
||
{
|
||
RDEBUG(5, "blocked pid %d got a signal; sending -ERESTARTSYS",
|
||
current->pid);
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
return -ERESTARTSYS;
|
||
}
|
||
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
/* re-lock the device, so we can do our msg_in check again */
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
}
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* ok - at this point we are awake due to a message received. */
|
||
|
||
if ( transaction->msg_in->cmd != FUSD_FOPS_REPLY ||
|
||
transaction->msg_in->subcmd != transaction->subcmd ||
|
||
transaction->msg_in->parm.fops_msg.transid != transaction->transid ||
|
||
transaction->msg_in->parm.fops_msg.fusd_file != fusd_file )
|
||
{
|
||
RDEBUG(2, "fusd_fops_call: invalid reply!");
|
||
goto invalid_reply;
|
||
}
|
||
|
||
/* copy metadata back from userspace */
|
||
fusd_file->file->f_flags = transaction->msg_in->parm.fops_msg.flags;
|
||
fusd_file->private_data = transaction->msg_in->parm.fops_msg.private_info;
|
||
/* note, changes to device_info are NO LONGER honored here */
|
||
|
||
/* if everything's okay, return the return value. if caller is
|
||
* willing to take responsibility for freeing the message itself, we
|
||
* return the message too. */
|
||
retval = transaction->msg_in->parm.fops_msg.retval;
|
||
if ( fusd_msg_reply != NULL )
|
||
{
|
||
/* NOW TRANSFERRING RESPONSIBILITY FOR FREEING THIS DATA TO THE CALLER */
|
||
*fusd_msg_reply = transaction->msg_in;
|
||
transaction->msg_in = NULL;
|
||
}
|
||
else
|
||
{
|
||
/* free the message ourselves */
|
||
free_fusd_msg(&transaction->msg_in);
|
||
}
|
||
|
||
/* success */
|
||
fusd_cleanup_transaction(fusd_file, transaction);
|
||
return retval;
|
||
|
||
invalid_reply:
|
||
fusd_cleanup_transaction(fusd_file, transaction);
|
||
return -EPIPE;
|
||
|
||
/* bizarre errors go straight here */
|
||
invalid_dev:
|
||
invalid_file :
|
||
RDEBUG(0, "fusd_fops_call: got invalid device or file!!!!");
|
||
return -EPIPE;
|
||
|
||
zombie_dev:
|
||
RDEBUG(2, "fusd_fops_call: %s zombified while waiting for reply",
|
||
NAME(fusd_dev));
|
||
return -EPIPE;
|
||
}
|
||
|
||
/* fusd client system call handlers should call this after they call
|
||
* fops_call, to destroy the message that was returned to them. */
|
||
STATIC void fusd_transaction_done (struct fusd_transaction *transaction)
|
||
{
|
||
transaction->transid = -1;
|
||
transaction->pid = 0;
|
||
}
|
||
|
||
|
||
|
||
/********* Functions for opening a FUSD device *******************/
|
||
|
||
|
||
/*
|
||
* The process of having a client open a FUSD device is surprisingly
|
||
* tricky -- perhaps the most complex piece of FUSD (or, a close
|
||
* second to poll_diffs). Race conditions are rampant here.
|
||
*
|
||
* The main problem is that there is a race between clients trying to
|
||
* open the FUSD device, and providers unregistering it (e.g., the
|
||
* driver dying). If the device-unregister callback starts, and is
|
||
* scheduled out after it locks the fusd device but before it
|
||
* unregisters the device with devfs, the open callback might be
|
||
* invoked in this interval. This means the client will down() on a
|
||
* semaphore that is about to be freed when the device is destroyed.
|
||
*
|
||
* The only way to fix this, as far as I can tell, is for device
|
||
* registration and unregistration to both share a global lock; the
|
||
* client checks its 'private_data' pointer to make sure it's on the
|
||
* list of valid devices. If so, it sets a flag (open_in_progress)
|
||
* which means "Don't free this device yet!". Then, it releases the
|
||
* global lock, grabs the device lock, and tries to add itself as a
|
||
* "file" to the device array. It is then safe to decrement
|
||
* open_in_progress, because being a member of the file array will
|
||
* guarantee that the device will zombify instead of being freed.
|
||
*
|
||
* Another gotcha: To avoid infinitely dining with philosophers, the
|
||
* global lock (fusd_devlist_sem) should always be acquired AFTER a
|
||
* fusd device is locked. The code path that frees devices acquires
|
||
* the device lock FIRST, so the code here must do the same.
|
||
*
|
||
* Because of the complexity of opening a file, I've broken it up into
|
||
* multiple sub-functions.
|
||
*/
|
||
|
||
/*
|
||
* fusd_dev_is_valid: If a fusd device is valid, returns 1, and will have
|
||
* set the "open_in_progress" flag on the device.
|
||
*/
|
||
int fusd_dev_is_valid (fusd_dev_t *fusd_dev)
|
||
{
|
||
struct list_head *tmp;
|
||
int dev_found = 0;
|
||
|
||
/* The first thing we must do is acquire the global lock on the
|
||
* device list, and make sure this device is valid; if so, mark it
|
||
* as being "in use". If we don't do this, there's a race: after we
|
||
* enter this function, the device may be unregistered. */
|
||
down(&fusd_devlist_sem);
|
||
|
||
list_for_each(tmp, &fusd_devlist_head)
|
||
{
|
||
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
|
||
|
||
if ( d == fusd_dev && d->magic == FUSD_DEV_MAGIC && !ZOMBIE(d) )
|
||
{
|
||
dev_found = 1;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* A device will not be deallocated when this counter is >0 */
|
||
if ( dev_found )
|
||
fusd_dev->open_in_progress++;
|
||
|
||
up(&fusd_devlist_sem);
|
||
|
||
return dev_found;
|
||
}
|
||
|
||
int fusd_dev_add_file (struct file *file, fusd_dev_t *fusd_dev, fusd_file_t **fusd_file_ret)
|
||
{
|
||
fusd_file_t *fusd_file;
|
||
int i;
|
||
|
||
/* Make sure the device didn't become a zombie while we were waiting
|
||
* for the device lock */
|
||
if ( ZOMBIE(fusd_dev) )
|
||
return -ENOENT;
|
||
|
||
/* this shouldn't happen. maybe i'm insane, but i check anyway. */
|
||
for ( i = 0; i < fusd_dev->num_files; i++ )
|
||
if ( fusd_dev->files[i]->file == file )
|
||
{
|
||
RDEBUG(1, "warning: fusd_client_open got open for already-open file!?");
|
||
return -EIO;
|
||
}
|
||
|
||
/* You can't open your own file! Return -EDEADLOCK if someone tries to.
|
||
*
|
||
* XXX - TODO - FIXME - This should eventually be more general
|
||
* deadlock detection of arbitrary length cycles */
|
||
if ( current->pid == fusd_dev->pid )
|
||
{
|
||
RDEBUG(3, "pid %d tried to open its own device (/dev/%s)",
|
||
fusd_dev->pid, NAME(fusd_dev));
|
||
return -EDEADLOCK;
|
||
}
|
||
|
||
/* make more space in the file array if we need it */
|
||
if ( fusd_dev->num_files == fusd_dev->array_size &&
|
||
fusd_dev->array_size < MAX_FILEARRAY_SIZE )
|
||
fusd_dev_adjsize(fusd_dev);
|
||
|
||
/* make sure we have room... adjsize may have failed */
|
||
if ( fusd_dev->num_files >= fusd_dev->array_size )
|
||
{
|
||
RDEBUG(1, "/dev/%s out of state space for open files!", NAME(fusd_dev));
|
||
return -ENOMEM;
|
||
}
|
||
|
||
/* create state for this file */
|
||
if ( ( fusd_file = KMALLOC(sizeof (fusd_file_t ), GFP_KERNEL) ) == NULL )
|
||
{
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
return -ENOMEM;
|
||
}
|
||
memset(fusd_file, 0, sizeof (fusd_file_t ));
|
||
init_waitqueue_head(&fusd_file->file_wait);
|
||
init_waitqueue_head(&fusd_file->poll_wait);
|
||
INIT_LIST_HEAD(&fusd_file->transactions);
|
||
init_MUTEX(&fusd_file->file_sem);
|
||
init_MUTEX(&fusd_file->transactions_sem);
|
||
fusd_file->last_poll_sent = -1;
|
||
fusd_file->magic = FUSD_FILE_MAGIC;
|
||
fusd_file->fusd_dev = fusd_dev;
|
||
fusd_file->fusd_dev_version = fusd_dev->version;
|
||
fusd_file->file = file;
|
||
|
||
/* add this file to the list of files managed by the device */
|
||
fusd_file->index = fusd_dev->num_files++;
|
||
fusd_dev->files[fusd_file->index] = fusd_file;
|
||
|
||
/* store the pointer to this file with the kernel */
|
||
file->private_data = fusd_file;
|
||
*fusd_file_ret = fusd_file;
|
||
|
||
/* success! */
|
||
return 0;
|
||
}
|
||
|
||
STATIC struct fusd_dev_t_s* find_user_device (int dev_id)
|
||
{
|
||
struct list_head* entry;
|
||
down(&fusd_devlist_sem);
|
||
|
||
list_for_each(entry, &fusd_devlist_head)
|
||
{
|
||
fusd_dev_t *d = list_entry(entry, fusd_dev_t, devlist);
|
||
if ( d->dev_id == dev_id )
|
||
{
|
||
up(&fusd_devlist_sem);
|
||
return d;
|
||
}
|
||
}
|
||
up(&fusd_devlist_sem);
|
||
return NULL;
|
||
}
|
||
|
||
/*
|
||
* A client has called open() has been called on a registered device.
|
||
* See comment higher up for detailed notes on this function.
|
||
*/
|
||
STATIC int fusd_client_open (struct inode *inode, struct file *file)
|
||
{
|
||
int retval;
|
||
int device_freed = 0;
|
||
fusd_dev_t *fusd_dev = find_user_device(inode->i_rdev);
|
||
fusd_file_t *fusd_file;
|
||
fusd_msg_t fusd_msg;
|
||
struct fusd_transaction* transaction;
|
||
|
||
/* If the device wasn't on our valid list, stop here. */
|
||
if ( !fusd_dev_is_valid(fusd_dev) )
|
||
return -ENOENT;
|
||
|
||
/* fusd_dev->open_in_progress now set */
|
||
|
||
/* Lock the fusd device. Note, when we finally do acquire the lock,
|
||
* the device might be a zombie (driver disappeared). */
|
||
RAWLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
RDEBUG(3, "got an open for /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
/* Try to add ourselves to the device's file list. If retval==0, we
|
||
are now part of the file array. */
|
||
retval = fusd_dev_add_file(file, fusd_dev, &fusd_file);
|
||
|
||
/*
|
||
* It is now safe to unset the open_in_progress flag. Either:
|
||
* 1) We are part of the file array, so dev won't be freed, or;
|
||
* 2) Something failed, so we are returning a failure now and no
|
||
* longer need the device.
|
||
* Note, open_in_progress must be protected by the global sem, not
|
||
* the device lock, due to the access of it in fusd_dev_is_valid().
|
||
*/
|
||
down(&fusd_devlist_sem);
|
||
fusd_dev->open_in_progress--;
|
||
up(&fusd_devlist_sem);
|
||
|
||
/* If adding ourselves to the device list failed, give up. Possibly
|
||
* free the device if it was a zombie and waiting for us to complete
|
||
* our open. */
|
||
if ( retval < 0 )
|
||
{
|
||
if ( !maybe_free_fusd_dev(fusd_dev) )
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
return retval;
|
||
}
|
||
|
||
/* send message to userspace and get retval */
|
||
init_fusd_msg(&fusd_msg);
|
||
fusd_msg.subcmd = FUSD_OPEN;
|
||
|
||
/* send message to userspace and get the reply. Device can't be
|
||
* locked during that operation. */
|
||
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction);
|
||
|
||
if ( retval >= 0 )
|
||
retval = fusd_fops_call_wait(fusd_file, NULL, transaction);
|
||
RAWLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* If the device zombified (while we were waiting to reacquire the
|
||
* lock)... consider that a failure */
|
||
if ( ZOMBIE(fusd_dev) )
|
||
retval = -ENOENT;
|
||
|
||
/* if retval is negative, throw away state... the file open failed */
|
||
if ( retval < 0 )
|
||
{
|
||
RDEBUG(3, "...open failed for /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
device_freed = free_fusd_file(fusd_dev, fusd_file);
|
||
}
|
||
|
||
/* Now unlock the device, if it still exists. (It may have been
|
||
* freed if the open failed, and we were the last outstanding
|
||
* request for it.) */
|
||
if ( !device_freed )
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
return retval;
|
||
}
|
||
|
||
/* close() has been called on a registered device. like
|
||
* fusd_client_open, we must lock the entire device. */
|
||
STATIC int fusd_client_release (struct inode *inode, struct file *file)
|
||
{
|
||
int retval;
|
||
fusd_file_t *fusd_file;
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_msg_t fusd_msg;
|
||
struct fusd_transaction* transaction;
|
||
|
||
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
|
||
RDEBUG(3, "got a close on /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
/* Tell the driver that the file closed, if it still exists. */
|
||
init_fusd_msg(&fusd_msg);
|
||
fusd_msg.subcmd = FUSD_CLOSE;
|
||
retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction);
|
||
RDEBUG(5, "fusd_client_release: send returned %d", retval);
|
||
if ( retval >= 0 )
|
||
retval = fusd_fops_call_wait(fusd_file, NULL, transaction);
|
||
|
||
RDEBUG(5, "fusd_client_release: call_wait %d", retval);
|
||
/* delete the file off the device's file-list, and free it. note
|
||
* that device may be a zombie right now and may be freed when we
|
||
* come back from free_fusd_file. we only release the lock if the
|
||
* device still exists. */
|
||
RAWLOCK_FUSD_DEV(fusd_dev);
|
||
if ( !free_fusd_file(fusd_dev, fusd_file) )
|
||
{
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
}
|
||
|
||
return retval;
|
||
|
||
invalid_dev:
|
||
invalid_file :
|
||
RDEBUG(1, "got a close on client file from pid %d, INVALID DEVICE!",
|
||
current->pid);
|
||
return -EPIPE;
|
||
}
|
||
|
||
STATIC ssize_t fusd_client_read (struct file *file, char *buf,
|
||
size_t count, loff_t *offset)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
struct fusd_transaction* transaction;
|
||
fusd_msg_t fusd_msg, *reply = NULL;
|
||
int retval = -EPIPE;
|
||
|
||
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
|
||
|
||
if ( ZOMBIE(fusd_dev) )
|
||
goto zombie_dev;
|
||
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
|
||
RDEBUG(3, "got a read on /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_READ);
|
||
if ( transaction && transaction->size > count )
|
||
{
|
||
RDEBUG(2, "Incomplete I/O transaction %ld thrown out, as the transaction's size of %d bytes was greater than "
|
||
"the retry's size of %d bytes", transaction->transid, transaction->size, (int) count);
|
||
|
||
fusd_cleanup_transaction(fusd_file, transaction);
|
||
transaction = NULL;
|
||
}
|
||
|
||
if ( transaction == NULL )
|
||
{
|
||
/* make sure we aren't trying to read too big of a buffer */
|
||
if ( count > MAX_RW_SIZE )
|
||
count = MAX_RW_SIZE;
|
||
|
||
/* send the message */
|
||
init_fusd_msg(&fusd_msg);
|
||
fusd_msg.subcmd = FUSD_READ;
|
||
fusd_msg.parm.fops_msg.length = count;
|
||
|
||
/* send message to userspace */
|
||
if ( ( retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction) ) < 0 )
|
||
goto done;
|
||
}
|
||
|
||
/* and wait for the reply */
|
||
/* todo: store and retrieve the transid from the interrupted messsage */
|
||
retval = fusd_fops_call_wait(fusd_file, &reply, transaction);
|
||
|
||
/* return immediately in case of error */
|
||
if ( retval < 0 || reply == NULL )
|
||
goto done;
|
||
|
||
/* adjust the reval if the retval indicates a larger read than the
|
||
* data that was actually provided */
|
||
if ( reply->datalen != retval )
|
||
{
|
||
RDEBUG(1, "warning: /dev/%s driver (pid %d) claimed it returned %d bytes "
|
||
"on read but actually returned %d",
|
||
NAME(fusd_dev), fusd_dev->pid, retval, reply->datalen);
|
||
retval = reply->datalen;
|
||
}
|
||
|
||
/* adjust if the device driver gave us more data than the user asked for
|
||
* (bad! bad! why is the driver broken???) */
|
||
if ( retval > count )
|
||
{
|
||
RDEBUG(1, "warning: /dev/%s driver (pid %d) returned %d bytes on read but "
|
||
"the user only asked for %d",
|
||
NAME(fusd_dev), fusd_dev->pid, retval, (int) count);
|
||
retval = count;
|
||
}
|
||
|
||
/* copy the offset back from the message */
|
||
*offset = reply->parm.fops_msg.offset;
|
||
|
||
/* IFF return value indicates data present, copy it back */
|
||
if ( retval > 0 )
|
||
{
|
||
if ( copy_to_user(buf, reply->data, retval) )
|
||
{
|
||
retval = -EFAULT;
|
||
goto done;
|
||
}
|
||
}
|
||
|
||
done:
|
||
/* clear the readable bit of our cached poll state */
|
||
fusd_file->cached_poll_state &= ~( FUSD_NOTIFY_INPUT );
|
||
|
||
free_fusd_msg(&reply);
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
return retval;
|
||
|
||
invalid_file:
|
||
invalid_dev :
|
||
zombie_dev :
|
||
RDEBUG(3, "got a read on client file from pid %d, driver has disappeared",
|
||
current->pid);
|
||
return -EPIPE;
|
||
}
|
||
|
||
STATIC int fusd_add_transaction (fusd_file_t *fusd_file, int transid, int subcmd, int size, struct fusd_transaction** out_transaction)
|
||
{
|
||
struct fusd_transaction* transaction = (struct fusd_transaction*) KMALLOC(sizeof (struct fusd_transaction), GFP_KERNEL);
|
||
if ( transaction == NULL )
|
||
return -ENOMEM;
|
||
|
||
transaction->msg_in = NULL;
|
||
transaction->transid = transid;
|
||
transaction->subcmd = subcmd;
|
||
transaction->pid = current->pid;
|
||
transaction->size = size;
|
||
|
||
down(&fusd_file->transactions_sem);
|
||
list_add_tail(&transaction->list, &fusd_file->transactions);
|
||
up(&fusd_file->transactions_sem);
|
||
|
||
if ( out_transaction != NULL )
|
||
*out_transaction = transaction;
|
||
|
||
return 0;
|
||
}
|
||
|
||
STATIC void fusd_cleanup_transaction (fusd_file_t *fusd_file, struct fusd_transaction* transaction)
|
||
{
|
||
free_fusd_msg(&transaction->msg_in);
|
||
fusd_remove_transaction(fusd_file, transaction);
|
||
}
|
||
|
||
STATIC void fusd_remove_transaction (fusd_file_t *fusd_file, struct fusd_transaction* transaction)
|
||
{
|
||
down(&fusd_file->transactions_sem);
|
||
list_del(&transaction->list);
|
||
up(&fusd_file->transactions_sem);
|
||
|
||
KFREE(transaction);
|
||
}
|
||
|
||
STATIC struct fusd_transaction* fusd_find_transaction (fusd_file_t *fusd_file, int transid)
|
||
{
|
||
struct list_head* i;
|
||
down(&fusd_file->transactions_sem);
|
||
|
||
list_for_each(i, &fusd_file->transactions)
|
||
{
|
||
struct fusd_transaction* transaction = list_entry(i, struct fusd_transaction, list);
|
||
if ( transaction->transid == transid )
|
||
{
|
||
up(&fusd_file->transactions_sem);
|
||
return transaction;
|
||
}
|
||
}
|
||
up(&fusd_file->transactions_sem);
|
||
return NULL;
|
||
}
|
||
|
||
STATIC struct fusd_transaction* fusd_find_transaction_by_pid (fusd_file_t *fusd_file, int pid)
|
||
{
|
||
struct list_head* i;
|
||
down(&fusd_file->transactions_sem);
|
||
|
||
list_for_each(i, &fusd_file->transactions)
|
||
{
|
||
struct fusd_transaction* transaction = list_entry(i, struct fusd_transaction, list);
|
||
if ( transaction->pid == pid )
|
||
{
|
||
up(&fusd_file->transactions_sem);
|
||
return transaction;
|
||
}
|
||
}
|
||
up(&fusd_file->transactions_sem);
|
||
return NULL;
|
||
}
|
||
|
||
STATIC ssize_t fusd_client_write (struct file *file,
|
||
const char *buffer,
|
||
size_t length,
|
||
loff_t *offset)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
fusd_msg_t fusd_msg;
|
||
fusd_msg_t *reply = NULL;
|
||
int retval = -EPIPE;
|
||
struct fusd_transaction* transaction;
|
||
|
||
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
|
||
|
||
if ( ZOMBIE(fusd_dev) )
|
||
goto zombie_dev;
|
||
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
|
||
RDEBUG(3, "got a write on /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_WRITE);
|
||
if ( transaction && transaction->size != length )
|
||
{
|
||
RDEBUG(2, "Incomplete I/O transaction %ld thrown out, as the transaction's size of %d bytes was not equal to "
|
||
"the retry's size of %d bytes", transaction->transid, transaction->size, (int) length);
|
||
|
||
fusd_cleanup_transaction(fusd_file, transaction);
|
||
transaction = NULL;
|
||
}
|
||
if ( transaction == NULL )
|
||
{
|
||
if ( length < 0 )
|
||
{
|
||
RDEBUG(2, "fusd_client_write: got invalid length %d", (int) length);
|
||
retval = -EINVAL;
|
||
goto done;
|
||
}
|
||
|
||
if ( length > MAX_RW_SIZE )
|
||
length = MAX_RW_SIZE;
|
||
|
||
init_fusd_msg(&fusd_msg);
|
||
|
||
/* sigh.. i guess zero length writes should be legal */
|
||
if ( length > 0 )
|
||
{
|
||
if ( ( fusd_msg.data = VMALLOC(length) ) == NULL )
|
||
{
|
||
retval = -ENOMEM;
|
||
goto done;
|
||
}
|
||
|
||
if ( copy_from_user(fusd_msg.data, buffer, length) )
|
||
{
|
||
retval = -EFAULT;
|
||
goto done;
|
||
}
|
||
fusd_msg.datalen = length;
|
||
}
|
||
|
||
fusd_msg.subcmd = FUSD_WRITE;
|
||
fusd_msg.parm.fops_msg.length = length;
|
||
|
||
if ( ( retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction) ) < 0 )
|
||
goto done;
|
||
}
|
||
/* todo: fix transid on restart */
|
||
retval = fusd_fops_call_wait(fusd_file, &reply, transaction);
|
||
|
||
if ( retval < 0 || reply == NULL )
|
||
goto done;
|
||
|
||
/* drivers should not write more bytes than they were asked to! */
|
||
if ( retval > length )
|
||
{
|
||
RDEBUG(1, "warning: /dev/%s driver (pid %d) returned %d bytes on write; "
|
||
"the user only wanted %d",
|
||
NAME(fusd_dev), fusd_dev->pid, retval, (int) length);
|
||
retval = length;
|
||
}
|
||
|
||
*offset = reply->parm.fops_msg.offset;
|
||
|
||
/* all done! */
|
||
|
||
done:
|
||
/* clear the writable bit of our cached poll state */
|
||
fusd_file->cached_poll_state &= ~( FUSD_NOTIFY_OUTPUT );
|
||
|
||
free_fusd_msg(&reply);
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
return retval;
|
||
|
||
invalid_file:
|
||
invalid_dev :
|
||
zombie_dev :
|
||
RDEBUG(3, "got a write on client file from pid %d, driver has disappeared",
|
||
current->pid);
|
||
return -EPIPE;
|
||
}
|
||
|
||
STATIC int fusd_client_ioctl (struct inode *inode, struct file *file,
|
||
unsigned int cmd, unsigned long arg)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
fusd_msg_t fusd_msg, *reply = NULL;
|
||
int retval = -EPIPE, dir, length;
|
||
struct fusd_transaction* transaction;
|
||
|
||
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
|
||
|
||
if ( ZOMBIE(fusd_dev) )
|
||
goto zombie_dev;
|
||
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
|
||
RDEBUG(3, "got an ioctl on /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
dir = _IOC_DIR(cmd);
|
||
length = _IOC_SIZE(cmd);
|
||
|
||
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_IOCTL);
|
||
// todo: Check to make sure the transaction is for the same IOCTL
|
||
|
||
if ( transaction == NULL )
|
||
{
|
||
/* if we're trying to read or write, make sure length is sane */
|
||
if ( ( dir & ( _IOC_WRITE | _IOC_READ ) ) &&
|
||
( length <= 0 || length > MAX_RW_SIZE ) )
|
||
{
|
||
RDEBUG(2, "client ioctl got crazy IOC_SIZE of %d", length);
|
||
retval = -EINVAL;
|
||
goto done;
|
||
}
|
||
|
||
/* fill the struct */
|
||
init_fusd_msg(&fusd_msg);
|
||
fusd_msg.subcmd = FUSD_IOCTL;
|
||
fusd_msg.parm.fops_msg.cmd = cmd;
|
||
fusd_msg.parm.fops_msg.arg.arg = arg;
|
||
|
||
/* get the data if user is trying to write to the driver */
|
||
if ( dir & _IOC_WRITE )
|
||
{
|
||
if ( ( fusd_msg.data = VMALLOC(length) ) == NULL )
|
||
{
|
||
RDEBUG(2, "can't vmalloc for client ioctl!");
|
||
retval = -ENOMEM;
|
||
goto done;
|
||
}
|
||
|
||
if ( copy_from_user(fusd_msg.data, (void *) arg, length) )
|
||
{
|
||
retval = -EFAULT;
|
||
goto done;
|
||
}
|
||
fusd_msg.datalen = length;
|
||
}
|
||
|
||
/* send request to the driver */
|
||
if ( ( retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction) ) < 0 )
|
||
goto done;
|
||
}
|
||
/* get the response */
|
||
/* todo: fix transid on restart */
|
||
if ( ( retval = fusd_fops_call_wait(fusd_file, &reply, transaction) ) < 0 || reply == NULL )
|
||
goto done;
|
||
|
||
/* if user is trying to read from the driver, copy data back */
|
||
if ( dir & _IOC_READ )
|
||
{
|
||
if ( reply->data == NULL || reply->datalen != length )
|
||
{
|
||
RDEBUG(2, "client_ioctl read reply with screwy data (%d, %d)",
|
||
reply->datalen, length);
|
||
retval = -EIO;
|
||
goto done;
|
||
}
|
||
if ( copy_to_user((void *) arg, reply->data, length) )
|
||
{
|
||
retval = -EFAULT;
|
||
goto done;
|
||
}
|
||
}
|
||
|
||
/* all done! */
|
||
done:
|
||
free_fusd_msg(&reply);
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
return retval;
|
||
|
||
invalid_file:
|
||
invalid_dev :
|
||
zombie_dev :
|
||
RDEBUG(3, "got an ioctl on client file from pid %d, driver has disappeared",
|
||
current->pid);
|
||
return -EPIPE;
|
||
}
|
||
static void fusd_client_mm_open (struct vm_area_struct * vma);
|
||
static void fusd_client_mm_close (struct vm_area_struct * vma);
|
||
static int fusd_client_fault (struct vm_area_struct *vma, struct vm_fault *vmf, int *type);
|
||
static struct vm_operations_struct fusd_remap_vm_ops ={
|
||
open : fusd_client_mm_open,
|
||
close : fusd_client_mm_close,
|
||
fault : fusd_client_fault,
|
||
};
|
||
|
||
struct fusd_mmap_instance
|
||
{
|
||
fusd_dev_t* fusd_dev;
|
||
fusd_file_t* fusd_file;
|
||
unsigned long addr;
|
||
int size;
|
||
atomic_t refcount;
|
||
};
|
||
|
||
static void fusd_client_mm_open (struct vm_area_struct * vma)
|
||
{
|
||
struct fusd_mmap_instance* mmap_instance = (struct fusd_mmap_instance*) vma->vm_private_data;
|
||
atomic_inc(&mmap_instance->refcount);
|
||
|
||
}
|
||
|
||
static void fusd_client_mm_close (struct vm_area_struct * vma)
|
||
{
|
||
struct fusd_mmap_instance* mmap_instance = (struct fusd_mmap_instance*) vma->vm_private_data;
|
||
if ( atomic_dec_and_test(&mmap_instance->refcount) )
|
||
{
|
||
KFREE(mmap_instance);
|
||
}
|
||
}
|
||
|
||
static int fusd_client_mmap (struct file *file, struct vm_area_struct * vma)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
struct fusd_transaction* transaction;
|
||
fusd_msg_t fusd_msg, *reply = NULL;
|
||
int retval = -EPIPE;
|
||
struct fusd_mmap_instance* mmap_instance;
|
||
|
||
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
|
||
|
||
if ( ZOMBIE(fusd_dev) )
|
||
goto zombie_dev;
|
||
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
|
||
RDEBUG(3, "got a mmap on /dev/%s (owned by pid %d) from pid %d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid);
|
||
|
||
transaction = fusd_find_incomplete_transaction(fusd_file, FUSD_MMAP);
|
||
|
||
if ( transaction == NULL )
|
||
{
|
||
/* send the message */
|
||
init_fusd_msg(&fusd_msg);
|
||
fusd_msg.subcmd = FUSD_MMAP;
|
||
fusd_msg.parm.fops_msg.offset = vma->vm_pgoff << PAGE_SHIFT;
|
||
fusd_msg.parm.fops_msg.flags = vma->vm_flags;
|
||
fusd_msg.parm.fops_msg.length = vma->vm_end - vma->vm_start;
|
||
|
||
/* send message to userspace */
|
||
if ( ( retval = fusd_fops_call_send(fusd_file, &fusd_msg, &transaction) ) < 0 )
|
||
goto done;
|
||
}
|
||
|
||
/* and wait for the reply */
|
||
/* todo: store and retrieve the transid from the interrupted messsage */
|
||
retval = fusd_fops_call_wait(fusd_file, &reply, transaction);
|
||
|
||
mmap_instance =
|
||
(struct fusd_mmap_instance*) KMALLOC(sizeof (struct fusd_mmap_instance), GFP_KERNEL);
|
||
// todo: free this thing at some point
|
||
|
||
mmap_instance->fusd_dev = fusd_dev;
|
||
mmap_instance->fusd_file = fusd_file;
|
||
mmap_instance->addr = reply->parm.fops_msg.arg.arg;
|
||
mmap_instance->size = reply->parm.fops_msg.length;
|
||
atomic_set(&mmap_instance->refcount, 0);
|
||
|
||
retval = reply->parm.fops_msg.retval;
|
||
|
||
vma->vm_private_data = mmap_instance;
|
||
vma->vm_ops = &fusd_remap_vm_ops;
|
||
vma->vm_flags |= VM_RESERVED;
|
||
|
||
fusd_client_mm_open(vma);
|
||
|
||
done:
|
||
free_fusd_msg(&reply);
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
return retval;
|
||
|
||
invalid_file:
|
||
invalid_dev :
|
||
zombie_dev :
|
||
RDEBUG(3, "got a mmap on client file from pid %d, driver has disappeared",
|
||
current->pid);
|
||
return -EPIPE;
|
||
}
|
||
|
||
static int fusd_client_fault (struct vm_area_struct *vma, struct vm_fault *vmf, int *type)
|
||
{
|
||
struct fusd_mmap_instance* mmap_instance = (struct fusd_mmap_instance*) vma->vm_private_data;
|
||
unsigned long offset;
|
||
struct page *page = NULL;
|
||
int result;
|
||
|
||
offset = ( (unsigned long) vmf->virtual_address - vma->vm_start ) + ( vma->vm_pgoff << PAGE_SHIFT );
|
||
// todo: worry about size
|
||
if ( offset > mmap_instance->size )
|
||
goto out;
|
||
|
||
down_read(&mmap_instance->fusd_dev->task->mm->mmap_sem);
|
||
result = get_user_pages(mmap_instance->fusd_dev->task, mmap_instance->fusd_dev->task->mm, mmap_instance->addr + offset, 1, 1, 0, &page, NULL);
|
||
up_read(&mmap_instance->fusd_dev->task->mm->mmap_sem);
|
||
|
||
|
||
if ( PageAnon(vmf->page) )
|
||
{
|
||
RDEBUG(2, "Cannot mmap anonymous pages. Be sure to allocate your shared buffer with MAP_SHARED | MAP_ANONYMOUS");
|
||
return VM_FAULT_SIGBUS;
|
||
}
|
||
|
||
if ( result > 0 )
|
||
{
|
||
get_page(page);
|
||
vmf->page = page;
|
||
if ( type )
|
||
*type = VM_FAULT_MINOR;
|
||
}
|
||
out:
|
||
return 0;
|
||
}
|
||
|
||
/*
|
||
* The design of poll for clients is a bit subtle.
|
||
*
|
||
* We don't want the select() call itself to block, so we keep a cache
|
||
* of the most recently known state supplied by the driver. The cache
|
||
* is initialized to 0 (meaning: nothing readable/writable).
|
||
*
|
||
* When a poll comes in, we do a non-blocking (!) dispatch of a
|
||
* command telling the driver "This is the state we have cached, reply
|
||
* to this call when the state changes.", and then immediately return
|
||
* the cached state. We tell the kernel's select to sleep on our
|
||
* poll_wait wait queue.
|
||
*
|
||
* When the driver replies, we update our cached info and wake up the
|
||
* wait queue. Waking up the wait queue will most likely immediately
|
||
* effect a poll again, in which case we will reply whatever we just
|
||
* cached from the driver.
|
||
*
|
||
*/
|
||
STATIC unsigned int fusd_client_poll (struct file *file, poll_table *wait)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_file_t *fusd_file;
|
||
int kernel_bits = 0;
|
||
int send_poll = 0;
|
||
|
||
GET_FUSD_FILE_AND_DEV(file->private_data, fusd_file, fusd_dev);
|
||
LOCK_FUSD_FILE(fusd_file);
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
|
||
RDEBUG(3, "got a select on /dev/%s (owned by pid %d) from pid %d, cps=%d",
|
||
NAME(fusd_dev), fusd_dev->pid, current->pid,
|
||
fusd_file->cached_poll_state);
|
||
|
||
poll_wait(file, &fusd_file->poll_wait, wait);
|
||
|
||
/*
|
||
* If our currently cached poll state is not the same as the
|
||
* most-recently-sent polldiff request, then, dispatch a new
|
||
* request. (We DO NOT wait for a reply, but just dispatch the
|
||
* request).
|
||
*
|
||
* Also, don't send a new polldiff if the most recent one resulted
|
||
* in an error.
|
||
*/
|
||
if ( fusd_file->last_poll_sent != fusd_file->cached_poll_state &&
|
||
fusd_file->cached_poll_state >= 0 )
|
||
{
|
||
RDEBUG(3, "sending polldiff request because lps=%d, cps=%d",
|
||
fusd_file->last_poll_sent, fusd_file->cached_poll_state);
|
||
send_poll = 1;
|
||
fusd_file->last_poll_sent = fusd_file->cached_poll_state;
|
||
}
|
||
|
||
/* compute what to return for the state we had cached, converting to
|
||
* bits that have meaning to the kernel */
|
||
if ( fusd_file->cached_poll_state > 0 )
|
||
{
|
||
if ( fusd_file->cached_poll_state & FUSD_NOTIFY_INPUT )
|
||
kernel_bits |= POLLIN;
|
||
if ( fusd_file->cached_poll_state & FUSD_NOTIFY_OUTPUT )
|
||
kernel_bits |= POLLOUT;
|
||
if ( fusd_file->cached_poll_state & FUSD_NOTIFY_EXCEPT )
|
||
kernel_bits |= POLLPRI;
|
||
}
|
||
|
||
/* Now that we've committed to sending the poll, etc., it should be
|
||
* safe to unlock the device */
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
|
||
if ( send_poll )
|
||
{
|
||
fusd_msg_t fusd_msg;
|
||
|
||
init_fusd_msg(&fusd_msg);
|
||
fusd_msg.cmd = FUSD_FOPS_NONBLOCK;
|
||
fusd_msg.subcmd = FUSD_POLL_DIFF;
|
||
fusd_msg.parm.fops_msg.cmd = fusd_file->cached_poll_state;
|
||
if ( fusd_fops_call_send(fusd_file, &fusd_msg, NULL) < 0 )
|
||
{
|
||
/* If poll dispatched failed, set back to -1 so we try again.
|
||
* Not a race (I think), since sending an *extra* polldiff never
|
||
* hurts anything. */
|
||
fusd_file->last_poll_sent = -1;
|
||
}
|
||
}
|
||
return kernel_bits;
|
||
|
||
zombie_dev:
|
||
/* might jump here from LOCK_FUSD_DEV */
|
||
UNLOCK_FUSD_FILE(fusd_file);
|
||
invalid_dev:
|
||
invalid_file :
|
||
RDEBUG(3, "got a select on client file from pid %d, driver has disappeared",
|
||
current->pid);
|
||
return POLLPRI;
|
||
}
|
||
|
||
|
||
|
||
STATIC struct file_operations fusd_client_fops = {
|
||
owner : THIS_MODULE,
|
||
open : fusd_client_open,
|
||
release : fusd_client_release,
|
||
read : fusd_client_read,
|
||
write : fusd_client_write,
|
||
ioctl : fusd_client_ioctl,
|
||
poll : fusd_client_poll,
|
||
mmap : fusd_client_mmap
|
||
};
|
||
|
||
|
||
/*************************************************************************/
|
||
/*************************************************************************/
|
||
/*************************************************************************/
|
||
|
||
|
||
STATIC fusd_file_t *find_fusd_reply_file (fusd_dev_t *fusd_dev, fusd_msg_t *msg)
|
||
{
|
||
/* first, try the hint */
|
||
int i = msg->parm.fops_msg.hint;
|
||
if ( i >= 0 &&
|
||
i < fusd_dev->num_files &&
|
||
fusd_dev->files[i] == msg->parm.fops_msg.fusd_file )
|
||
{
|
||
RDEBUG(15, "find_fusd_reply_file: hint worked");
|
||
}
|
||
else
|
||
{
|
||
/* hint didn't work, fall back to a search of the whole array */
|
||
i = find_fusd_file(fusd_dev, msg->parm.fops_msg.fusd_file);
|
||
RDEBUG(15, "find_fusd_reply_file: hint failed");
|
||
}
|
||
|
||
/* we couldn't find anyone waiting for this message! */
|
||
if ( i < 0 )
|
||
{
|
||
return NULL;
|
||
}
|
||
else
|
||
{
|
||
return fusd_dev->files[i];
|
||
}
|
||
}
|
||
|
||
/* Process an incoming reply to a message dispatched by
|
||
* fusd_fops_call. Called by fusd_write when a driver writes to
|
||
* /dev/fusd. */
|
||
STATIC int fusd_fops_reply (fusd_dev_t *fusd_dev, fusd_msg_t *msg)
|
||
{
|
||
fusd_file_t *fusd_file;
|
||
struct fusd_transaction *transaction;
|
||
|
||
/* figure out the index of the file we are replying to. usually
|
||
* very fast (uses a hint) */
|
||
if ( ( fusd_file = find_fusd_reply_file(fusd_dev, msg) ) == NULL )
|
||
{
|
||
RDEBUG(2, "fusd_fops_reply: got a reply on /dev/%s with no connection",
|
||
NAME(fusd_dev));
|
||
goto discard;
|
||
}
|
||
|
||
/* make sure this is not an old reply going to an old instance that's gone */
|
||
/* todo: kor fix this */
|
||
/*
|
||
if (fusd_file->fusd_dev_version != fusd_dev->version ||
|
||
msg->parm.fops_msg.transid != fusd_file->transid_outstanding) {
|
||
RDEBUG(2, "fusd_fops_reply: got an old message, discarding");
|
||
goto discard;
|
||
}*/
|
||
|
||
transaction = fusd_find_transaction(fusd_file, msg->parm.fops_msg.transid);
|
||
if ( transaction == NULL )
|
||
{
|
||
RDEBUG(2, "fusd_fops_reply: No transaction found with transid %ld", msg->parm.fops_msg.transid);
|
||
goto discard;
|
||
}
|
||
|
||
RDEBUG(10, "fusd_fops_reply: /dev/%s completed transid %ld (retval %d)",
|
||
NAME(fusd_dev), msg->parm.fops_msg.transid,
|
||
(int) msg->parm.fops_msg.retval);
|
||
|
||
transaction->msg_in = msg;
|
||
mb();
|
||
|
||
WAKE_UP_INTERRUPTIBLE_SYNC(&fusd_file->file_wait);
|
||
|
||
return 0;
|
||
|
||
discard:
|
||
if ( msg->subcmd == FUSD_OPEN && msg->parm.fops_msg.retval == 0 )
|
||
{
|
||
fusd_forge_close(msg, fusd_dev);
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
return -EPIPE;
|
||
}
|
||
}
|
||
|
||
/* special function to process responses to POLL_DIFF */
|
||
STATIC int fusd_polldiff_reply (fusd_dev_t *fusd_dev, fusd_msg_t *msg)
|
||
{
|
||
fusd_file_t *fusd_file;
|
||
|
||
/* figure out the index of the file we are replying to. usually
|
||
* very fast (uses a hint) */
|
||
if ( ( fusd_file = find_fusd_reply_file(fusd_dev, msg) ) == NULL )
|
||
return -EPIPE;
|
||
|
||
/* record the poll state returned. convert all negative retvals to -1. */
|
||
if ( ( fusd_file->cached_poll_state = msg->parm.fops_msg.retval ) < 0 )
|
||
fusd_file->cached_poll_state = -1;
|
||
|
||
RDEBUG(3, "got updated poll state from /dev/%s driver: %d", NAME(fusd_dev),
|
||
fusd_file->cached_poll_state);
|
||
|
||
/* since the client has returned the polldiff we sent, set
|
||
* last_poll_sent to -1, so that we'll send a polldiff request on
|
||
* the next select. */
|
||
fusd_file->last_poll_sent = -1;
|
||
|
||
/* wake up select's queue so that a new polldiff is generated */
|
||
wake_up_interruptible(&fusd_file->poll_wait);
|
||
|
||
return 0;
|
||
}
|
||
|
||
STATIC int systest (struct super_block *sb, void *data)
|
||
{
|
||
return 1;
|
||
|
||
}
|
||
|
||
STATIC int fusd_register_device (fusd_dev_t *fusd_dev,
|
||
register_msg_t register_msg)
|
||
{
|
||
int error = 0;
|
||
struct list_head *tmp;
|
||
int dev_id;
|
||
|
||
/* make sure args are valid */
|
||
if ( fusd_dev == NULL )
|
||
{
|
||
RDEBUG(0, "fusd_register_device: bug in arguments!");
|
||
return -EINVAL;
|
||
}
|
||
|
||
register_msg.name[FUSD_MAX_NAME_LENGTH] = '\0';
|
||
|
||
/* make sure that there isn't already a device by this name */
|
||
down(&fusd_devlist_sem);
|
||
|
||
list_for_each(tmp, &fusd_devlist_head)
|
||
{
|
||
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
|
||
|
||
|
||
if ( d && d->name && !d->zombie && !strcmp(d->name, register_msg.name) )
|
||
{
|
||
error = -EEXIST;
|
||
break;
|
||
}
|
||
}
|
||
|
||
up(&fusd_devlist_sem);
|
||
|
||
if ( error )
|
||
return error;
|
||
|
||
/* allocate memory for the name, and copy */
|
||
if ( ( fusd_dev->name = KMALLOC(strlen(register_msg.name) + 1, GFP_KERNEL) ) == NULL )
|
||
{
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
return -ENOMEM;
|
||
}
|
||
|
||
strcpy(fusd_dev->name, register_msg.name);
|
||
|
||
/* allocate memory for the class name, and copy */
|
||
if ( ( fusd_dev->class_name = KMALLOC(strlen(register_msg.clazz) + 1, GFP_KERNEL) ) == NULL )
|
||
{
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
return -ENOMEM;
|
||
}
|
||
|
||
strcpy(fusd_dev->class_name, register_msg.clazz);
|
||
|
||
/* allocate memory for the class name, and copy */
|
||
if ( ( fusd_dev->dev_name = KMALLOC(strlen(register_msg.devname) + 1, GFP_KERNEL) ) == NULL )
|
||
{
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
return -ENOMEM;
|
||
}
|
||
|
||
strcpy(fusd_dev->dev_name, register_msg.devname);
|
||
|
||
dev_id = 0;
|
||
|
||
if ( ( error = alloc_chrdev_region(&dev_id, 0, 1, fusd_dev->name) ) < 0 )
|
||
{
|
||
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", error);
|
||
goto register_failed;
|
||
}
|
||
|
||
fusd_dev->dev_id = dev_id;
|
||
|
||
fusd_dev->handle = cdev_alloc();
|
||
if ( fusd_dev->handle == NULL )
|
||
{
|
||
printk(KERN_ERR "cdev_alloc() failed\n");
|
||
error = -ENOMEM;
|
||
goto register_failed3;
|
||
}
|
||
|
||
fusd_dev->handle->owner = THIS_MODULE;
|
||
fusd_dev->handle->ops = &fusd_client_fops;
|
||
|
||
kobject_set_name(&fusd_dev->handle->kobj, fusd_dev->name);
|
||
|
||
if ( ( error = cdev_add(fusd_dev->handle, dev_id, 1) ) < 0 )
|
||
{
|
||
printk(KERN_ERR "cdev_add failed status: %d\n", error);
|
||
kobject_put(&fusd_dev->handle->kobj);
|
||
goto register_failed3;
|
||
}
|
||
|
||
/* look up class in sysfs */
|
||
{
|
||
struct CLASS *sys_class = NULL;
|
||
struct file_system_type *sysfs = get_fs_type("sysfs");
|
||
struct dentry *classdir = NULL;
|
||
struct dentry *classdir2 = NULL;
|
||
struct super_block *sb = NULL;
|
||
|
||
if ( sysfs )
|
||
{
|
||
/* Get FS superblock */
|
||
sb = sget(sysfs, systest, NULL, NULL);
|
||
|
||
/* because put_filesystem isn't exported */
|
||
module_put(sysfs->owner);
|
||
|
||
if ( sb )
|
||
{
|
||
/* Take root entry from SuperBlock */
|
||
struct dentry *root = sb->s_root;
|
||
|
||
if ( root )
|
||
{
|
||
struct qstr name;
|
||
|
||
/* Search for directory "class" in the root of this filesystem */
|
||
name.name = "class";
|
||
name.len = 5;
|
||
name.hash = full_name_hash(name.name, name.len);
|
||
classdir = d_lookup(root, &name);
|
||
|
||
if ( classdir )
|
||
{
|
||
/* Found, now search for class wanted name */
|
||
name.name = register_msg.clazz;
|
||
name.len = strlen(name.name);
|
||
name.hash = full_name_hash(name.name, name.len);
|
||
classdir2 = d_lookup(classdir, &name);
|
||
|
||
if ( classdir2 )
|
||
{
|
||
// jackpot. extract the class.
|
||
struct kobject *ko = to_kobj(classdir2);
|
||
sys_class = ( ko ? to_class(ko)->class : NULL );
|
||
|
||
if ( sys_class )
|
||
{
|
||
/* W T F ???? Using an existing sys_class will led to a NULL pointer crash
|
||
* during device creation.. Need more investigation, this comportement is clearly not
|
||
* normal. */
|
||
RDEBUG(1, "ERROR: Using existing class name is currently unsported !!!");
|
||
goto register_failed4;
|
||
}
|
||
|
||
if ( !sys_class )
|
||
RDEBUG(2, "WARNING: sysfs entry for %s has no kobject!\n", register_msg.clazz);
|
||
}
|
||
|
||
}
|
||
else
|
||
{
|
||
RDEBUG(2, "WARNING: sysfs does not list a class directory!\n");
|
||
}
|
||
}
|
||
else
|
||
{
|
||
RDEBUG(2, "WARNING: unable to access root firectory in sysfs!\n");
|
||
}
|
||
}
|
||
else
|
||
{
|
||
RDEBUG(2, "WARNING: unable to access superblock for sysfs!\n");
|
||
}
|
||
}
|
||
else
|
||
{
|
||
RDEBUG(2, "WARNING: sysfs not mounted or unavailable!\n");
|
||
}
|
||
|
||
if ( sys_class )
|
||
{
|
||
RDEBUG(3, "Found entry for class '%s' in sysfs\n", register_msg.clazz);
|
||
fusd_dev->clazz = sys_class;
|
||
fusd_dev->owns_class = 0;
|
||
}
|
||
else
|
||
{
|
||
RDEBUG(3, "Sysfs has no entry for '%s'; registering new class\n", register_msg.clazz);
|
||
fusd_dev->clazz = class_create(THIS_MODULE, fusd_dev->class_name);
|
||
if ( IS_ERR(fusd_dev->clazz) )
|
||
{
|
||
error = PTR_ERR(fusd_dev->clazz);
|
||
printk(KERN_ERR "class_create failed status: %d\n", error);
|
||
goto register_failed4;
|
||
}
|
||
fusd_dev->owns_class = 1;
|
||
}
|
||
|
||
if ( classdir )
|
||
dput(classdir);
|
||
if ( classdir2 )
|
||
dput(classdir2);
|
||
|
||
if ( sb )
|
||
{
|
||
up_write(&sb->s_umount);
|
||
deactivate_super(sb);
|
||
}
|
||
}
|
||
|
||
/* Dump sys_class */
|
||
RDEBUG(9, "fusd_dev->clazz = { .name='%s' .owner=%p .class_attrs=%p\n"
|
||
".dev_attrs=%p .dev_kobj=%p .dev_uevent=%p\n"
|
||
".devnode=%p .class_release=%p .dev_release=%p\n"
|
||
".suspend=%p .resume=%p .pm=%p\n"
|
||
".p = %p };",
|
||
fusd_dev->clazz->name, fusd_dev->clazz->owner, fusd_dev->clazz->class_attrs,
|
||
fusd_dev->clazz->dev_attrs, fusd_dev->clazz->dev_kobj, fusd_dev->clazz->dev_uevent,
|
||
fusd_dev->clazz->devnode, fusd_dev->clazz->class_release, fusd_dev->clazz->dev_release,
|
||
fusd_dev->clazz->suspend, fusd_dev->clazz->resume, fusd_dev->clazz->pm, fusd_dev->clazz->p);
|
||
fusd_dev->device = CLASS_DEVICE_CREATE(fusd_dev->clazz, NULL, fusd_dev->dev_id, NULL, fusd_dev->dev_name);
|
||
if ( fusd_dev->device == NULL )
|
||
{
|
||
error = PTR_ERR(fusd_dev->device);
|
||
printk(KERN_ERR "device_create failed status: %d\n", error);
|
||
goto register_failed5;
|
||
}
|
||
|
||
/* make sure the registration was successful */
|
||
if ( fusd_dev->handle == 0 )
|
||
{
|
||
error = -EIO;
|
||
goto register_failed;
|
||
}
|
||
|
||
/* remember the user's private data so we can pass it back later */
|
||
fusd_dev->private_data = register_msg.device_info;
|
||
|
||
/* everything ok */
|
||
fusd_dev->version = atomic_inc_and_ret(&last_version);
|
||
RDEBUG(3, "pid %d registered /dev/%s v%ld", fusd_dev->pid, NAME(fusd_dev),
|
||
fusd_dev->version);
|
||
wake_up_interruptible(&new_device_wait);
|
||
return 0;
|
||
|
||
register_failed5:
|
||
class_destroy(fusd_dev->clazz);
|
||
fusd_dev->clazz = NULL;
|
||
register_failed4:
|
||
cdev_del(fusd_dev->handle);
|
||
fusd_dev->handle = NULL;
|
||
register_failed3:
|
||
|
||
//register_failed2:
|
||
unregister_chrdev_region(dev_id, 1);
|
||
register_failed:
|
||
KFREE(fusd_dev->name);
|
||
fusd_dev->name = NULL;
|
||
return error;
|
||
}
|
||
|
||
|
||
/****************************************************************************/
|
||
/******************** CONTROL CHANNEL CALLBACK FUNCTIONS ********************/
|
||
/****************************************************************************/
|
||
|
||
/* open() called on /dev/fusd itself */
|
||
STATIC int fusd_open (struct inode *inode, struct file *file)
|
||
{
|
||
fusd_dev_t *fusd_dev = NULL;
|
||
fusd_file_t **file_array = NULL;
|
||
|
||
/* keep the module from being unloaded during initialization! */
|
||
//MOD_INC_USE_COUNT;
|
||
|
||
/* allocate memory for the device state */
|
||
if ( ( fusd_dev = KMALLOC(sizeof (fusd_dev_t ), GFP_KERNEL) ) == NULL )
|
||
goto dev_malloc_failed;
|
||
memset(fusd_dev, 0, sizeof (fusd_dev_t ));
|
||
|
||
if ( ( file_array = fusd_dev_adjsize(fusd_dev) ) == NULL )
|
||
goto file_malloc_failed;
|
||
|
||
init_waitqueue_head(&fusd_dev->dev_wait);
|
||
init_MUTEX(&fusd_dev->dev_sem);
|
||
fusd_dev->magic = FUSD_DEV_MAGIC;
|
||
fusd_dev->pid = current->pid;
|
||
fusd_dev->task = current;
|
||
file->private_data = fusd_dev;
|
||
|
||
/* add to the list of valid devices */
|
||
down(&fusd_devlist_sem);
|
||
list_add(&fusd_dev->devlist, &fusd_devlist_head);
|
||
up(&fusd_devlist_sem);
|
||
|
||
RDEBUG(3, "pid %d opened /dev/fusd", fusd_dev->pid);
|
||
return 0;
|
||
|
||
file_malloc_failed:
|
||
KFREE(fusd_dev);
|
||
dev_malloc_failed:
|
||
RDEBUG(1, "out of memory in fusd_open!");
|
||
//MOD_DEC_USE_COUNT;
|
||
return -ENOMEM;
|
||
}
|
||
|
||
/* close() called on /dev/fusd itself. destroy the device that
|
||
* was registered by it, if any. */
|
||
STATIC int fusd_release (struct inode *inode, struct file *file)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
|
||
GET_FUSD_DEV(file->private_data, fusd_dev);
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
|
||
if ( fusd_dev->pid != current->pid )
|
||
{
|
||
RDEBUG(2, "yikes!: when releasing device, pid mismatch");
|
||
}
|
||
|
||
RDEBUG(3, "pid %d closing /dev/fusd", current->pid);
|
||
|
||
#if 0
|
||
/* This delay is needed to exercise the openrace.c race condition,
|
||
* i.e. testing to make sure that our open_in_progress stuff works */
|
||
{
|
||
int target = jiffies + 10 * HZ;
|
||
|
||
RDEBUG(1, "starting to wait");
|
||
while ( jiffies < target )
|
||
schedule();
|
||
RDEBUG(1, "stopping wait");
|
||
}
|
||
#endif
|
||
|
||
if ( fusd_dev->handle )
|
||
{
|
||
CLASS_DEVICE_DESTROY(fusd_dev->clazz, fusd_dev->dev_id);
|
||
if ( fusd_dev->owns_class )
|
||
{
|
||
class_destroy(fusd_dev->clazz);
|
||
}
|
||
cdev_del(fusd_dev->handle);
|
||
unregister_chrdev_region(fusd_dev->dev_id, 1);
|
||
}
|
||
|
||
/* mark the driver as being gone */
|
||
zombify_dev(fusd_dev);
|
||
|
||
/* ...and possibly free it. (Release lock if it hasn't been freed) */
|
||
if ( !maybe_free_fusd_dev(fusd_dev) )
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* notify fusd_status readers that there has been a change in the
|
||
* list of registered devices */
|
||
atomic_inc_and_ret(&last_version);
|
||
wake_up_interruptible(&new_device_wait);
|
||
|
||
return 0;
|
||
|
||
zombie_dev:
|
||
invalid_dev :
|
||
RDEBUG(1, "invalid device found in fusd_release!!");
|
||
return -ENODEV;
|
||
}
|
||
|
||
/*
|
||
* This function processes messages coming from userspace device drivers
|
||
* (i.e., writes to the /dev/fusd control channel.)
|
||
*/
|
||
STATIC ssize_t fusd_process_write (struct file *file,
|
||
const char *user_msg_buffer, size_t user_msg_len,
|
||
const char *user_data_buffer, size_t user_data_len)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_msg_t *msg = NULL;
|
||
int retval = 0;
|
||
int yield = 0;
|
||
|
||
GET_FUSD_DEV(file->private_data, fusd_dev);
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* get the header from userspace (first make sure there's enough data) */
|
||
if ( user_msg_len != sizeof (fusd_msg_t ) )
|
||
{
|
||
RDEBUG(6, "control channel got bad write of %d bytes (wanted %d)",
|
||
(int) user_msg_len, (int) sizeof (fusd_msg_t ));
|
||
retval = -EINVAL;
|
||
goto out_no_free;
|
||
}
|
||
if ( ( msg = KMALLOC(sizeof (fusd_msg_t ), GFP_KERNEL) ) == NULL )
|
||
{
|
||
retval = -ENOMEM;
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
goto out;
|
||
}
|
||
memset(msg, 0, sizeof (fusd_msg_t ));
|
||
|
||
if ( copy_from_user(msg, user_msg_buffer, sizeof (fusd_msg_t )) )
|
||
{
|
||
retval = -EFAULT;
|
||
goto out;
|
||
}
|
||
msg->data = NULL; /* pointers from userspace have no meaning */
|
||
|
||
/* check the magic number before acting on the message at all */
|
||
if ( msg->magic != FUSD_MSG_MAGIC )
|
||
{
|
||
RDEBUG(2, "got invalid magic number on /dev/fusd write from pid %d",
|
||
current->pid);
|
||
retval = -EIO;
|
||
goto out;
|
||
}
|
||
|
||
/* now get data portion of the message */
|
||
if ( user_data_len < 0 || user_data_len > MAX_RW_SIZE )
|
||
{
|
||
RDEBUG(2, "fusd_process_write: got invalid length %d", (int) user_data_len);
|
||
retval = -EINVAL;
|
||
goto out;
|
||
}
|
||
if ( msg->datalen != user_data_len )
|
||
{
|
||
RDEBUG(2, "%s : msg->datalen(%d) != user_data_len(%d), sigh!", __func__,
|
||
msg->datalen, (int) user_data_len);
|
||
retval = -EINVAL;
|
||
goto out;
|
||
}
|
||
if ( user_data_len > 0 )
|
||
{
|
||
if ( user_data_buffer == NULL )
|
||
{
|
||
RDEBUG(2, "msg->datalen and no data buffer, sigh!");
|
||
retval = -EINVAL;
|
||
goto out;
|
||
}
|
||
if ( ( msg->data = VMALLOC(user_data_len) ) == NULL )
|
||
{
|
||
retval = -ENOMEM;
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
goto out;
|
||
}
|
||
if ( copy_from_user(msg->data, user_data_buffer, user_data_len) )
|
||
{
|
||
retval = -EFAULT;
|
||
goto out;
|
||
}
|
||
}
|
||
|
||
/* before device registration, the only command allowed is 'register'. */
|
||
/*
|
||
if (!fusd_dev->handle && msg->cmd != FUSD_REGISTER_DEVICE) {
|
||
RDEBUG(2, "got a message other than 'register' on a new device!");
|
||
retval = -EINVAL;
|
||
goto out;
|
||
}
|
||
*/
|
||
|
||
/* now dispatch the command to the appropriate handler */
|
||
switch ( msg->cmd )
|
||
{
|
||
case FUSD_REGISTER_DEVICE:
|
||
retval = fusd_register_device(fusd_dev, msg->parm.register_msg);
|
||
goto out;
|
||
break;
|
||
case FUSD_FOPS_REPLY:
|
||
/* if reply is successful, DO NOT free the message */
|
||
if ( ( retval = fusd_fops_reply(fusd_dev, msg) ) == 0 )
|
||
{
|
||
yield = 1;
|
||
goto out_no_free;
|
||
}
|
||
break;
|
||
case FUSD_FOPS_NONBLOCK_REPLY:
|
||
switch ( msg->subcmd )
|
||
{
|
||
case FUSD_POLL_DIFF:
|
||
retval = fusd_polldiff_reply(fusd_dev, msg);
|
||
break;
|
||
default:
|
||
RDEBUG(2, "fusd_fops_nonblock got unknown subcmd %d", msg->subcmd);
|
||
retval = -EINVAL;
|
||
}
|
||
break;
|
||
default:
|
||
RDEBUG(2, "warning: unknown message type of %d received!", msg->cmd);
|
||
retval = -EINVAL;
|
||
goto out;
|
||
break;
|
||
}
|
||
|
||
|
||
out:
|
||
if ( msg && msg->data )
|
||
{
|
||
VFREE(msg->data);
|
||
msg->data = NULL;
|
||
}
|
||
if ( msg != NULL )
|
||
{
|
||
KFREE(msg);
|
||
msg = NULL;
|
||
}
|
||
|
||
out_no_free:
|
||
|
||
/* the functions we call indicate success by returning 0. we
|
||
* convert that into a success indication by changing the retval to
|
||
* the length of the write. */
|
||
if ( retval == 0 )
|
||
retval = user_data_len + user_msg_len;
|
||
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* if we successfully completed someone's syscall, yield the
|
||
* processor to them immediately as a throughput optimization. we
|
||
* also hope that in the case of bulk data transfer, their next
|
||
* syscall will come in before we are scheduled again. */
|
||
if ( yield )
|
||
{
|
||
#ifdef SCHED_YIELD
|
||
current->policy |= SCHED_YIELD;
|
||
#endif
|
||
schedule();
|
||
}
|
||
|
||
return retval;
|
||
|
||
zombie_dev:
|
||
invalid_dev :
|
||
RDEBUG(1, "fusd_process_write: got invalid device!");
|
||
return -EPIPE;
|
||
}
|
||
|
||
STATIC ssize_t fusd_write (struct file *file,
|
||
const char *buffer,
|
||
size_t length,
|
||
loff_t *offset)
|
||
{
|
||
RDEBUG(1, "%s: [%p:%p:%d:%p] [sl: %d]!!", __func__, file, buffer, length, offset, sizeof (fusd_msg_t ));
|
||
return fusd_process_write(file, buffer, length, NULL, 0);
|
||
}
|
||
|
||
STATIC ssize_t fusd_writev (struct file *file,
|
||
const struct iovec *iov,
|
||
unsigned long count,
|
||
loff_t *offset)
|
||
{
|
||
if ( count != 2 )
|
||
{
|
||
RDEBUG(2, "fusd_writev: got illegal iov count of %ld", count);
|
||
return -EINVAL;
|
||
}
|
||
|
||
return fusd_process_write(file,
|
||
iov[0].iov_base, iov[0].iov_len,
|
||
iov[1].iov_base, iov[1].iov_len);
|
||
}
|
||
|
||
STATIC int fusd_ioctl (struct inode *inode, struct file *file,
|
||
unsigned int cmd, unsigned long arg)
|
||
{
|
||
void __user *argp = (void __user *) arg;
|
||
struct iovec iov;
|
||
|
||
if ( ( argp != NULL ) && ( cmd == 0xb16b00b5 ) )
|
||
{
|
||
RDEBUG(9, "%s: !!!!!!! ( o )( o ) !!!!!!!", __func__);
|
||
|
||
/* Act like writev... */
|
||
copy_from_user(&iov, argp, sizeof (struct iovec) * 2);
|
||
return fusd_writev(file, &iov, 2, NULL);
|
||
}
|
||
RDEBUG(2, "%s: got illegal ioctl #%08X# Or ARG is null [%p]", __func__, cmd, argp);
|
||
return -EINVAL;
|
||
}
|
||
|
||
/* fusd_read: a process is reading on /dev/fusd. return any messages
|
||
* waiting to go from kernel to userspace.
|
||
*
|
||
* Important note: there are 2 possible read modes;
|
||
* 1) header-read mode; just the fusd_msg structure is returned.
|
||
*
|
||
* 2) data-read mode; the data portion of a call (NOT including the
|
||
* fusd_msg structure) is returned.
|
||
*
|
||
* The protocol this function expects the user-space library to follow
|
||
* is:
|
||
* 1) Userspace library reads header.
|
||
* 2) If fusd_msg->datalen == 0, goto step 4.
|
||
* 3) Userspace library reads data.
|
||
* 4) Message gets dequeued by the kernel.
|
||
*
|
||
* In other words, userspace first reads the header. Then, if and
|
||
* only if the header you read indicates that data follows, userspace
|
||
* follows with a read for that data.
|
||
*
|
||
* For the header read, the length requested MUST be the exact length
|
||
* sizeof(fusd_msg_t). The corresponding data read must request
|
||
* exactly the number of bytes in the data portion of the message. NO
|
||
* OTHER READ LENGTHS ARE ALLOWED - ALL OTHER READ LENGTHS WILL GET AN
|
||
* -EINVAL. This is done as a basic safety measure to make sure we're
|
||
* talking to a userspace library that understands our protocol, and
|
||
* to detect framing errors.
|
||
*
|
||
* (note: normally you'd have to worry about reentrancy in a function
|
||
* like this because the process can block on the userspace access and
|
||
* another might try to read. usually we would copy the message into
|
||
* a temp location to make sure two processes don't get the same
|
||
* message. however in this very specialized case, we're okay,
|
||
* because each instance of /dev/fusd has a completely independent
|
||
* message queue.) */
|
||
|
||
/* do a "header" read: used by fusd_read */
|
||
STATIC int fusd_read_header (char *user_buffer, size_t user_length, fusd_msg_t *msg)
|
||
{
|
||
int len = sizeof (fusd_msg_t );
|
||
|
||
if ( user_length != len )
|
||
{
|
||
RDEBUG(4, "bad length of %d sent to /dev/fusd for peek", (int) user_length);
|
||
return -EINVAL;
|
||
}
|
||
|
||
if ( copy_to_user(user_buffer, msg, len) )
|
||
return -EFAULT;
|
||
|
||
return sizeof (fusd_msg_t );
|
||
}
|
||
|
||
/* do a "data" read: used by fusd_read */
|
||
STATIC int fusd_read_data (char *user_buffer, size_t user_length, fusd_msg_t *msg)
|
||
{
|
||
int len = msg->datalen;
|
||
|
||
if ( len == 0 || msg->data == NULL )
|
||
{
|
||
RDEBUG(1, "fusd_read_data: no data to send!");
|
||
return -EIO;
|
||
}
|
||
|
||
/* make sure the user is requesting exactly the right amount (as a
|
||
sanity check) */
|
||
if ( user_length != len )
|
||
{
|
||
RDEBUG(4, "bad read for %d bytes on /dev/fusd (need %d)", (int) user_length, len);
|
||
return -EINVAL;
|
||
}
|
||
|
||
/* now copy to userspace */
|
||
if ( copy_to_user(user_buffer, msg->data, len) )
|
||
return -EFAULT;
|
||
|
||
/* done! */
|
||
return len;
|
||
}
|
||
|
||
STATIC ssize_t fusd_read (struct file *file,
|
||
char *user_buffer, /* The buffer to fill with data */
|
||
size_t user_length, /* The length of the buffer */
|
||
loff_t *offset) /* Our offset in the file */
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
fusd_msgC_t *msg_out;
|
||
int retval, dequeue = 0;
|
||
|
||
GET_FUSD_DEV(file->private_data, fusd_dev);
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
|
||
RDEBUG(15, "driver pid %d (/dev/%s) entering fusd_read", current->pid,
|
||
NAME(fusd_dev));
|
||
|
||
/* if no messages are waiting, either block or return EAGAIN */
|
||
while ( ( msg_out = fusd_dev->msg_head ) == NULL )
|
||
{
|
||
DECLARE_WAITQUEUE(wait, current);
|
||
|
||
if ( file->f_flags & O_NONBLOCK )
|
||
{
|
||
retval = -EAGAIN;
|
||
goto out;
|
||
}
|
||
|
||
/*
|
||
* sleep, waiting for a message to arrive. we are unrolling
|
||
* interruptible_sleep_on to avoid a race between unlocking the
|
||
* device and sleeping (what if a message arrives in that
|
||
* interval?)
|
||
*/
|
||
current->state = TASK_INTERRUPTIBLE;
|
||
add_wait_queue(&fusd_dev->dev_wait, &wait);
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
schedule();
|
||
remove_wait_queue(&fusd_dev->dev_wait, &wait);
|
||
LOCK_FUSD_DEV(fusd_dev);
|
||
|
||
/* we're back awake! --see if a signal woke us up */
|
||
if ( signal_pending(current) )
|
||
{
|
||
retval = -ERESTARTSYS;
|
||
goto out;
|
||
}
|
||
}
|
||
|
||
/* is this a header read or data read? */
|
||
if ( !msg_out->peeked )
|
||
{
|
||
/* this is a header read (first read) */
|
||
retval = fusd_read_header(user_buffer, user_length, &msg_out->fusd_msg);
|
||
|
||
/* is there data? if so, make sure next read gets data. if not,
|
||
* make sure message is dequeued now.*/
|
||
if ( msg_out->fusd_msg.datalen )
|
||
{
|
||
msg_out->peeked = 1;
|
||
dequeue = 0;
|
||
}
|
||
else
|
||
{
|
||
dequeue = 1;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* this is a data read (second read) */
|
||
retval = fusd_read_data(user_buffer, user_length, &msg_out->fusd_msg);
|
||
dequeue = 1; /* message should be dequeued */
|
||
}
|
||
|
||
/* if this message is done, take it out of the outgoing queue */
|
||
if ( dequeue )
|
||
{
|
||
if ( fusd_dev->msg_tail == fusd_dev->msg_head )
|
||
fusd_dev->msg_tail = fusd_dev->msg_head = NULL;
|
||
else
|
||
fusd_dev->msg_head = msg_out->next;
|
||
FREE_FUSD_MSGC(msg_out);
|
||
}
|
||
|
||
out:
|
||
UNLOCK_FUSD_DEV(fusd_dev);
|
||
return retval;
|
||
|
||
zombie_dev:
|
||
invalid_dev :
|
||
RDEBUG(2, "got read on /dev/fusd for unknown device!");
|
||
return -EPIPE;
|
||
}
|
||
|
||
/* a poll on /dev/fusd itself (the control channel) */
|
||
STATIC unsigned int fusd_poll (struct file *file, poll_table *wait)
|
||
{
|
||
fusd_dev_t *fusd_dev;
|
||
GET_FUSD_DEV(file->private_data, fusd_dev);
|
||
|
||
poll_wait(file, &fusd_dev->dev_wait, wait);
|
||
|
||
if ( fusd_dev->msg_head != NULL )
|
||
{
|
||
return POLLIN | POLLRDNORM;
|
||
}
|
||
|
||
invalid_dev:
|
||
return 0;
|
||
}
|
||
|
||
|
||
STATIC struct file_operations fusd_fops = {
|
||
owner : THIS_MODULE,
|
||
open : fusd_open,
|
||
read : fusd_read,
|
||
write : fusd_write,
|
||
//writev: fusd_writev,
|
||
ioctl : fusd_ioctl,
|
||
release : fusd_release,
|
||
poll : fusd_poll,
|
||
};
|
||
|
||
/*************************************************************************/
|
||
|
||
typedef struct fusd_status_state
|
||
{
|
||
int binary_status;
|
||
int need_new_status;
|
||
char *curr_status;
|
||
int curr_status_len;
|
||
int last_version_seen;
|
||
} fusd_statcontext_t;
|
||
|
||
/* open() called on /dev/fusd/status */
|
||
STATIC int fusd_status_open (struct inode *inode, struct file *file)
|
||
{
|
||
int error = 0;
|
||
fusd_statcontext_t *fs;
|
||
|
||
//MOD_INC_USE_COUNT;
|
||
|
||
if ( ( fs = KMALLOC(sizeof (fusd_statcontext_t ), GFP_KERNEL) ) == NULL )
|
||
{
|
||
RDEBUG(1, "yikes! kernel can't allocate memory");
|
||
error = -ENOMEM;
|
||
goto out;
|
||
}
|
||
|
||
memset(fs, 0, sizeof (fusd_statcontext_t ));
|
||
fs->need_new_status = 1;
|
||
file->private_data = (void *) fs;
|
||
|
||
out:
|
||
//if (error)
|
||
// MOD_DEC_USE_COUNT;
|
||
return error;
|
||
}
|
||
|
||
/* close on /dev/fusd_status */
|
||
STATIC int fusd_status_release (struct inode *inode, struct file *file)
|
||
{
|
||
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
|
||
|
||
if ( fs )
|
||
{
|
||
if ( fs->curr_status )
|
||
KFREE(fs->curr_status);
|
||
KFREE(fs);
|
||
}
|
||
|
||
//MOD_DEC_USE_COUNT;
|
||
return 0;
|
||
}
|
||
|
||
/* ioctl() on /dev/fusd/status */
|
||
STATIC int fusd_status_ioctl (struct inode *inode, struct file *file,
|
||
unsigned int cmd, unsigned long arg)
|
||
{
|
||
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
|
||
|
||
if ( !fs )
|
||
return -EIO;
|
||
|
||
switch ( cmd )
|
||
{
|
||
case FUSD_STATUS_USE_BINARY:
|
||
fs->binary_status = 1;
|
||
return 0;
|
||
default:
|
||
return -EINVAL;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/*
|
||
* maybe_expand_buffer: expand a buffer exponentially as it fills. We
|
||
* are given:
|
||
*
|
||
* - A reference to a pointer to a buffer (buf)
|
||
* - A reference to the buffer's current capacity (buf_size)
|
||
* - The current amount of buffer space used (len)
|
||
* - The amount of space we want to ensure is free in the buffer (space_needed)
|
||
*
|
||
* If there isn't at least space_needed difference between buf_size
|
||
* and len, the existing contents are moved into a larger buffer.
|
||
*/
|
||
STATIC int maybe_expand_buffer (char **buf, int *buf_size, int len,
|
||
int space_needed)
|
||
{
|
||
if ( *buf_size - len < space_needed )
|
||
{
|
||
char *old_buf = *buf;
|
||
|
||
*buf_size *= 2;
|
||
*buf = KMALLOC(*buf_size, GFP_KERNEL);
|
||
|
||
if ( *buf != NULL )
|
||
memmove(*buf, old_buf, len);
|
||
KFREE(old_buf);
|
||
if ( *buf == NULL )
|
||
{
|
||
RDEBUG(1, "out of memory!");
|
||
return -1;
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* Build a text buffer containing current fusd status. */
|
||
STATIC void fusd_status_build_text (fusd_statcontext_t *fs)
|
||
{
|
||
int buf_size = 512;
|
||
char *buf = KMALLOC(buf_size, GFP_KERNEL);
|
||
int len = 0, total_clients = 0, total_files = 0;
|
||
struct list_head *tmp;
|
||
|
||
if ( buf == NULL )
|
||
{
|
||
RDEBUG(1, "fusd_status_build: out of memory!");
|
||
return;
|
||
}
|
||
|
||
len += snprintf(buf + len, buf_size - len,
|
||
" PID Open Name\n"
|
||
"------ ---- -----------------\n");
|
||
|
||
down(&fusd_devlist_sem);
|
||
|
||
list_for_each(tmp, &fusd_devlist_head)
|
||
{
|
||
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
|
||
|
||
if ( !d )
|
||
continue;
|
||
|
||
/* Possibly expand the buffer if we need more space */
|
||
if ( maybe_expand_buffer(&buf, &buf_size, len, FUSD_MAX_NAME_LENGTH + 120) < 0 )
|
||
goto out;
|
||
|
||
len += snprintf(buf + len, buf_size - len,
|
||
"%6d %4d %s%s\n", d->pid, d->num_files,
|
||
d->zombie ? "<zombie>" : "", NAME(d));
|
||
|
||
total_files++;
|
||
total_clients += d->num_files;
|
||
}
|
||
|
||
len += snprintf(buf + len, buf_size - len,
|
||
"\nFUSD $Id$ - %d devices used by %d clients\n",
|
||
total_files, total_clients);
|
||
|
||
out:
|
||
fs->last_version_seen = last_version;
|
||
up(&fusd_devlist_sem);
|
||
|
||
if ( fs->curr_status )
|
||
KFREE(fs->curr_status);
|
||
|
||
fs->curr_status = buf;
|
||
fs->curr_status_len = len;
|
||
fs->need_new_status = 0;
|
||
}
|
||
|
||
/* Build the binary version of status */
|
||
STATIC void fusd_status_build_binary (fusd_statcontext_t *fs)
|
||
{
|
||
int buf_size = 512;
|
||
char *buf = KMALLOC(buf_size, GFP_KERNEL);
|
||
int len = 0, i = 0;
|
||
struct list_head *tmp;
|
||
fusd_status_t *s;
|
||
|
||
if ( buf == NULL )
|
||
{
|
||
RDEBUG(1, "out of memory!");
|
||
return;
|
||
}
|
||
|
||
down(&fusd_devlist_sem);
|
||
|
||
list_for_each(tmp, &fusd_devlist_head)
|
||
{
|
||
fusd_dev_t *d = list_entry(tmp, fusd_dev_t, devlist);
|
||
|
||
if ( !d )
|
||
continue;
|
||
|
||
/* Possibly expand the buffer if we need more space */
|
||
if ( maybe_expand_buffer(&buf, &buf_size, len, sizeof (fusd_status_t )) < 0 )
|
||
goto out;
|
||
|
||
s = &( (fusd_status_t *) buf )[i];
|
||
|
||
/* construct this status entry */
|
||
memset(s, 0, sizeof (fusd_status_t ));
|
||
strncpy(s->name, NAME(d), FUSD_MAX_NAME_LENGTH);
|
||
s->zombie = d->zombie;
|
||
s->pid = d->pid;
|
||
s->num_open = d->num_files;
|
||
|
||
i++;
|
||
len += sizeof (fusd_status_t );
|
||
}
|
||
|
||
out:
|
||
fs->last_version_seen = last_version;
|
||
up(&fusd_devlist_sem);
|
||
|
||
if ( fs->curr_status )
|
||
KFREE(fs->curr_status);
|
||
|
||
fs->curr_status = buf;
|
||
fs->curr_status_len = len;
|
||
fs->need_new_status = 0;
|
||
}
|
||
|
||
STATIC ssize_t fusd_status_read (struct file *file,
|
||
char *user_buffer, /* The buffer to fill with data */
|
||
size_t user_length, /* The length of the buffer */
|
||
loff_t *offset) /* Our offset in the file */
|
||
{
|
||
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
|
||
|
||
if ( !fs )
|
||
return -EIO;
|
||
|
||
/* create a new status page, if we aren't in the middle of one */
|
||
if ( fs->need_new_status )
|
||
{
|
||
if ( fs->binary_status )
|
||
fusd_status_build_binary(fs);
|
||
else
|
||
fusd_status_build_text(fs);
|
||
}
|
||
|
||
/* return EOF if we're at the end */
|
||
if ( fs->curr_status == NULL || fs->curr_status_len == 0 )
|
||
{
|
||
fs->need_new_status = 1;
|
||
return 0;
|
||
}
|
||
|
||
/* return only as much data as we have */
|
||
if ( fs->curr_status_len < user_length )
|
||
user_length = fs->curr_status_len;
|
||
if ( copy_to_user(user_buffer, fs->curr_status, user_length) )
|
||
return -EFAULT;
|
||
|
||
/* update fs, so we don't return the same data next time */
|
||
fs->curr_status_len -= user_length;
|
||
if ( fs->curr_status_len )
|
||
memmove(fs->curr_status, fs->curr_status + user_length, fs->curr_status_len);
|
||
else
|
||
{
|
||
KFREE(fs->curr_status);
|
||
fs->curr_status = NULL;
|
||
}
|
||
|
||
return user_length;
|
||
}
|
||
|
||
/* a poll on /dev/fusd itself (the control channel) */
|
||
STATIC unsigned int fusd_status_poll (struct file *file, poll_table *wait)
|
||
{
|
||
fusd_statcontext_t *fs = (fusd_statcontext_t *) file->private_data;
|
||
|
||
poll_wait(file, &new_device_wait, wait);
|
||
|
||
if ( fs->last_version_seen < last_version )
|
||
return POLLIN | POLLRDNORM;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
|
||
STATIC struct file_operations fusd_status_fops = {
|
||
owner : THIS_MODULE,
|
||
open : fusd_status_open,
|
||
ioctl : fusd_status_ioctl,
|
||
read : fusd_status_read,
|
||
release : fusd_status_release,
|
||
poll : fusd_status_poll,
|
||
};
|
||
|
||
/*************************************************************************/
|
||
|
||
|
||
STATIC int init_fusd (void)
|
||
{
|
||
int retval;
|
||
|
||
#ifdef CONFIG_FUSD_MEMDEBUG
|
||
if ( ( retval = fusd_mem_init() ) < 0 )
|
||
return retval;
|
||
#endif
|
||
|
||
|
||
printk(KERN_INFO
|
||
"fusd: starting, $Id$");
|
||
#ifdef CVSTAG
|
||
printk(", release %s", CVSTAG);
|
||
#endif
|
||
#ifdef CONFIG_FUSD_DEBUG
|
||
printk(", debuglevel=%d\n", fusd_debug_level);
|
||
#else
|
||
printk(", debugging messages disabled\n");
|
||
#endif
|
||
|
||
fusd_control_cdev = NULL;
|
||
fusd_status_cdev = NULL;
|
||
|
||
fusd_class = class_create(THIS_MODULE, "fusd");
|
||
if ( IS_ERR(fusd_class) )
|
||
{
|
||
retval = PTR_ERR(fusd_class);
|
||
printk(KERN_ERR "class_create failed status: %d\n", retval);
|
||
goto fail0;
|
||
}
|
||
|
||
control_id = 0;
|
||
|
||
if ( ( retval = alloc_chrdev_region(&control_id, 0, 1, FUSD_CONTROL_FILENAME) ) < 0 )
|
||
{
|
||
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", retval);
|
||
goto fail1;
|
||
}
|
||
|
||
fusd_control_cdev = cdev_alloc();
|
||
if ( fusd_control_cdev == NULL )
|
||
{
|
||
printk(KERN_ERR "cdev-alloc failed\n");
|
||
retval = -ENOMEM;
|
||
goto fail3;
|
||
}
|
||
|
||
fusd_control_cdev->owner = THIS_MODULE;
|
||
fusd_control_cdev->ops = &fusd_fops;
|
||
kobject_set_name(&fusd_control_cdev->kobj, FUSD_CONTROL_FILENAME);
|
||
|
||
printk(KERN_ERR "cdev control id: %d\n", control_id);
|
||
if ( ( retval = cdev_add(fusd_control_cdev, control_id, 1) ) < 0 )
|
||
{
|
||
printk(KERN_ERR "cdev_add failed status: %d\n", retval);
|
||
kobject_put(&fusd_control_cdev->kobj);
|
||
goto fail4;
|
||
}
|
||
|
||
fusd_control_device = CLASS_DEVICE_CREATE(fusd_class, NULL, control_id, NULL, "control");
|
||
if ( fusd_control_device == NULL )
|
||
{
|
||
retval = PTR_ERR(fusd_control_device);
|
||
printk("device_create failed status: %d\n", retval);
|
||
goto fail5;
|
||
}
|
||
|
||
status_id = 0;
|
||
|
||
if ( ( retval = alloc_chrdev_region(&status_id, 0, 1, FUSD_STATUS_FILENAME) ) < 0 )
|
||
{
|
||
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", retval);
|
||
goto fail6;
|
||
}
|
||
|
||
fusd_status_cdev = cdev_alloc();
|
||
if ( fusd_status_cdev == NULL )
|
||
{
|
||
retval = -ENOMEM;
|
||
goto fail8;
|
||
}
|
||
|
||
fusd_status_cdev->owner = THIS_MODULE;
|
||
fusd_status_cdev->ops = &fusd_status_fops;
|
||
kobject_set_name(&fusd_status_cdev->kobj, FUSD_STATUS_FILENAME);
|
||
|
||
if ( ( retval = cdev_add(fusd_status_cdev, status_id, 1) ) < 0 )
|
||
{
|
||
printk(KERN_ERR "cdev_add failed status: %d\n", retval);
|
||
kobject_put(&fusd_status_cdev->kobj);
|
||
goto fail9;
|
||
}
|
||
|
||
fusd_status_device = CLASS_DEVICE_CREATE(fusd_class, NULL, status_id, NULL, "status");
|
||
if ( fusd_status_device == NULL )
|
||
{
|
||
printk(KERN_ERR "device_create failed status: %d\n", retval);
|
||
retval = PTR_ERR(fusd_status_device);
|
||
goto fail10;
|
||
}
|
||
|
||
RDEBUG(1, "registration successful");
|
||
return 0;
|
||
|
||
fail10:
|
||
cdev_del(fusd_status_cdev);
|
||
fail9:
|
||
kfree(fusd_status_cdev);
|
||
fail8:
|
||
|
||
//fail7:
|
||
unregister_chrdev_region(status_id, 1);
|
||
fail6:
|
||
CLASS_DEVICE_DESTROY(fusd_class, control_id);
|
||
fail5:
|
||
cdev_del(fusd_control_cdev);
|
||
fail4:
|
||
kfree(fusd_control_cdev);
|
||
fail3:
|
||
|
||
//fail2:
|
||
unregister_chrdev_region(control_id, 1);
|
||
|
||
fail1:
|
||
class_destroy(fusd_class);
|
||
fail0:
|
||
return retval;
|
||
}
|
||
|
||
STATIC void cleanup_fusd (void)
|
||
{
|
||
RDEBUG(1, "cleaning up");
|
||
|
||
CLASS_DEVICE_DESTROY(fusd_class, status_id);
|
||
CLASS_DEVICE_DESTROY(fusd_class, control_id);
|
||
|
||
cdev_del(fusd_control_cdev);
|
||
cdev_del(fusd_status_cdev);
|
||
|
||
class_destroy(fusd_class);
|
||
|
||
#ifdef CONFIG_FUSD_MEMDEBUG
|
||
fusd_mem_cleanup();
|
||
#endif
|
||
}
|
||
|
||
module_init (init_fusd);
|
||
module_exit (cleanup_fusd);
|