2005-04-16 22:20:36 +00:00
|
|
|
/*
|
2007-09-20 08:31:38 +00:00
|
|
|
* fs/sysfs/file.c - sysfs regular (text) file implementation
|
|
|
|
*
|
|
|
|
* Copyright (c) 2001-3 Patrick Mochel
|
|
|
|
* Copyright (c) 2007 SUSE Linux Products GmbH
|
|
|
|
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
|
|
|
|
*
|
|
|
|
* This file is released under the GPLv2.
|
|
|
|
*
|
|
|
|
* Please see Documentation/filesystems/sysfs.txt for more information.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/kobject.h>
|
2008-03-04 23:09:07 +00:00
|
|
|
#include <linux/kallsyms.h>
|
2008-03-14 02:41:52 +00:00
|
|
|
#include <linux/slab.h>
|
2008-06-16 11:46:47 +00:00
|
|
|
#include <linux/fsnotify.h>
|
2005-06-23 07:09:12 +00:00
|
|
|
#include <linux/namei.h>
|
2006-03-20 06:53:53 +00:00
|
|
|
#include <linux/poll.h>
|
2006-12-20 09:52:44 +00:00
|
|
|
#include <linux/list.h>
|
2007-07-26 11:03:54 +00:00
|
|
|
#include <linux/mutex.h>
|
2007-08-24 23:11:54 +00:00
|
|
|
#include <linux/limits.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
#include <asm/uaccess.h>
|
|
|
|
|
|
|
|
#include "sysfs.h"
|
|
|
|
|
2007-08-24 23:11:54 +00:00
|
|
|
/* used in crash dumps to help with debugging */
|
|
|
|
static char last_sysfs_file[PATH_MAX];
|
|
|
|
void sysfs_printk_last_file(void)
|
|
|
|
{
|
|
|
|
printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
|
|
|
|
}
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
/*
|
|
|
|
* There's one sysfs_buffer for each open file and one
|
|
|
|
* sysfs_open_dirent for each sysfs_dirent with one or more open
|
|
|
|
* files.
|
|
|
|
*
|
|
|
|
* filp->private_data points to sysfs_buffer and
|
|
|
|
* sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open
|
|
|
|
* is protected by sysfs_open_dirent_lock.
|
|
|
|
*/
|
2007-11-21 22:55:19 +00:00
|
|
|
static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
|
2007-09-20 07:05:12 +00:00
|
|
|
|
|
|
|
struct sysfs_open_dirent {
|
|
|
|
atomic_t refcnt;
|
2007-09-20 07:05:12 +00:00
|
|
|
atomic_t event;
|
|
|
|
wait_queue_head_t poll;
|
2007-09-20 07:05:12 +00:00
|
|
|
struct list_head buffers; /* goes through sysfs_buffer.list */
|
|
|
|
};
|
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
struct sysfs_buffer {
|
|
|
|
size_t count;
|
|
|
|
loff_t pos;
|
|
|
|
char * page;
|
|
|
|
struct sysfs_ops * ops;
|
2007-07-26 11:03:54 +00:00
|
|
|
struct mutex mutex;
|
2007-06-13 18:45:16 +00:00
|
|
|
int needs_read_fill;
|
|
|
|
int event;
|
2007-09-20 07:05:12 +00:00
|
|
|
struct list_head list;
|
2007-06-13 18:45:16 +00:00
|
|
|
};
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/**
|
|
|
|
* fill_read_buffer - allocate and fill buffer from object.
|
|
|
|
* @dentry: dentry pointer.
|
|
|
|
* @buffer: data buffer for file.
|
|
|
|
*
|
|
|
|
* Allocate @buffer->page, if it hasn't been already, then call the
|
|
|
|
* kobject's show() method to fill the buffer with this attribute's
|
|
|
|
* data.
|
2007-01-02 07:48:08 +00:00
|
|
|
* This is called only once, on the file's first read unless an error
|
|
|
|
* is returned.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
|
|
|
static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer)
|
|
|
|
{
|
2007-06-13 18:45:16 +00:00
|
|
|
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
|
2007-09-20 07:05:11 +00:00
|
|
|
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
|
2005-04-16 22:20:36 +00:00
|
|
|
struct sysfs_ops * ops = buffer->ops;
|
|
|
|
int ret = 0;
|
|
|
|
ssize_t count;
|
|
|
|
|
|
|
|
if (!buffer->page)
|
|
|
|
buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
|
|
|
|
if (!buffer->page)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
/* need attr_sd for attr and ops, its parent for kobj */
|
|
|
|
if (!sysfs_get_active_two(attr_sd))
|
|
|
|
return -ENODEV;
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
buffer->event = atomic_read(&attr_sd->s_attr.open->event);
|
2007-09-20 07:05:11 +00:00
|
|
|
count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
|
2007-06-13 18:45:16 +00:00
|
|
|
|
|
|
|
sysfs_put_active_two(attr_sd);
|
|
|
|
|
2007-11-21 22:55:19 +00:00
|
|
|
/*
|
|
|
|
* The code works fine with PAGE_SIZE return but it's likely to
|
|
|
|
* indicate truncated result or overflow in normal use cases.
|
|
|
|
*/
|
2008-03-04 23:09:07 +00:00
|
|
|
if (count >= (ssize_t)PAGE_SIZE) {
|
|
|
|
print_symbol("fill_read_buffer: %s returned bad count\n",
|
|
|
|
(unsigned long)ops->show);
|
|
|
|
/* Try to struggle along */
|
|
|
|
count = PAGE_SIZE - 1;
|
|
|
|
}
|
2007-01-02 07:48:08 +00:00
|
|
|
if (count >= 0) {
|
|
|
|
buffer->needs_read_fill = 0;
|
2005-04-16 22:20:36 +00:00
|
|
|
buffer->count = count;
|
2007-01-02 07:48:08 +00:00
|
|
|
} else {
|
2005-04-16 22:20:36 +00:00
|
|
|
ret = count;
|
2007-01-02 07:48:08 +00:00
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sysfs_read_file - read an attribute.
|
|
|
|
* @file: file pointer.
|
|
|
|
* @buf: buffer to fill.
|
|
|
|
* @count: number of bytes to read.
|
|
|
|
* @ppos: starting offset in file.
|
|
|
|
*
|
|
|
|
* Userspace wants to read an attribute file. The attribute descriptor
|
|
|
|
* is in the file's ->d_fsdata. The target object is in the directory's
|
|
|
|
* ->d_fsdata.
|
|
|
|
*
|
|
|
|
* We call fill_read_buffer() to allocate and fill the buffer from the
|
|
|
|
* object's show() method exactly once (if the read is happening from
|
|
|
|
* the beginning of the file). That should fill the entire buffer with
|
|
|
|
* all the data the object has to offer for that attribute.
|
|
|
|
* We then call flush_read_buffer() to copy the buffer to userspace
|
|
|
|
* in the increments specified.
|
|
|
|
*/
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
|
|
|
|
{
|
|
|
|
struct sysfs_buffer * buffer = file->private_data;
|
|
|
|
ssize_t retval = 0;
|
|
|
|
|
2007-07-26 11:03:54 +00:00
|
|
|
mutex_lock(&buffer->mutex);
|
2008-04-07 22:35:01 +00:00
|
|
|
if (buffer->needs_read_fill || *ppos == 0) {
|
2007-06-13 18:45:16 +00:00
|
|
|
retval = fill_read_buffer(file->f_path.dentry,buffer);
|
2007-03-15 19:51:28 +00:00
|
|
|
if (retval)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto out;
|
|
|
|
}
|
2006-10-03 08:16:06 +00:00
|
|
|
pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
|
2008-04-30 07:55:09 +00:00
|
|
|
__func__, count, *ppos, buffer->page);
|
2007-05-09 09:33:32 +00:00
|
|
|
retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
|
|
|
|
buffer->count);
|
2005-04-16 22:20:36 +00:00
|
|
|
out:
|
2007-07-26 11:03:54 +00:00
|
|
|
mutex_unlock(&buffer->mutex);
|
2005-04-16 22:20:36 +00:00
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* fill_write_buffer - copy buffer from userspace.
|
|
|
|
* @buffer: data buffer for file.
|
2005-05-01 15:59:26 +00:00
|
|
|
* @buf: data from user.
|
2005-04-16 22:20:36 +00:00
|
|
|
* @count: number of bytes in @userbuf.
|
|
|
|
*
|
|
|
|
* Allocate @buffer->page if it hasn't been already, then
|
|
|
|
* copy the user-supplied buffer into it.
|
|
|
|
*/
|
|
|
|
|
|
|
|
static int
|
|
|
|
fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t count)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
|
|
|
if (!buffer->page)
|
|
|
|
buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
|
|
|
|
if (!buffer->page)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
if (count >= PAGE_SIZE)
|
2006-03-31 23:37:06 +00:00
|
|
|
count = PAGE_SIZE - 1;
|
2005-04-16 22:20:36 +00:00
|
|
|
error = copy_from_user(buffer->page,buf,count);
|
|
|
|
buffer->needs_read_fill = 1;
|
2006-10-22 17:17:47 +00:00
|
|
|
/* if buf is assumed to contain a string, terminate it by \0,
|
|
|
|
so e.g. sscanf() can scan the string easily */
|
|
|
|
buffer->page[count] = 0;
|
2005-04-16 22:20:36 +00:00
|
|
|
return error ? -EFAULT : count;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
* flush_write_buffer - push buffer to kobject.
|
2005-06-24 05:05:21 +00:00
|
|
|
* @dentry: dentry to the attribute
|
2005-04-16 22:20:36 +00:00
|
|
|
* @buffer: data buffer for file.
|
2005-06-24 05:05:21 +00:00
|
|
|
* @count: number of bytes
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
|
|
|
* Get the correct pointers for the kobject and the attribute we're
|
|
|
|
* dealing with, then call the store() method for the attribute,
|
|
|
|
* passing the buffer that we acquired in fill_write_buffer().
|
|
|
|
*/
|
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
static int
|
2005-04-16 22:20:36 +00:00
|
|
|
flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count)
|
|
|
|
{
|
2007-06-13 18:45:15 +00:00
|
|
|
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
|
2007-09-20 07:05:11 +00:00
|
|
|
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
|
2005-04-16 22:20:36 +00:00
|
|
|
struct sysfs_ops * ops = buffer->ops;
|
2007-06-13 18:45:16 +00:00
|
|
|
int rc;
|
|
|
|
|
|
|
|
/* need attr_sd for attr and ops, its parent for kobj */
|
|
|
|
if (!sysfs_get_active_two(attr_sd))
|
|
|
|
return -ENODEV;
|
|
|
|
|
2007-09-20 07:05:11 +00:00
|
|
|
rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);
|
2007-06-13 18:45:16 +00:00
|
|
|
|
|
|
|
sysfs_put_active_two(attr_sd);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
return rc;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sysfs_write_file - write an attribute.
|
|
|
|
* @file: file pointer
|
|
|
|
* @buf: data to write
|
|
|
|
* @count: number of bytes
|
|
|
|
* @ppos: starting offset
|
|
|
|
*
|
|
|
|
* Similar to sysfs_read_file(), though working in the opposite direction.
|
|
|
|
* We allocate and fill the data from the user in fill_write_buffer(),
|
|
|
|
* then push it to the kobject in flush_write_buffer().
|
|
|
|
* There is no easy way for us to know if userspace is only doing a partial
|
|
|
|
* write, so we don't support them. We expect the entire buffer to come
|
|
|
|
* on the first write.
|
|
|
|
* Hint: if you're writing a value, first read the file, modify only the
|
|
|
|
* the value you're changing, then write entire buffer back.
|
|
|
|
*/
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
|
|
|
|
{
|
|
|
|
struct sysfs_buffer * buffer = file->private_data;
|
|
|
|
ssize_t len;
|
|
|
|
|
2007-07-26 11:03:54 +00:00
|
|
|
mutex_lock(&buffer->mutex);
|
2005-04-16 22:20:36 +00:00
|
|
|
len = fill_write_buffer(buffer, buf, count);
|
|
|
|
if (len > 0)
|
2006-12-08 10:36:36 +00:00
|
|
|
len = flush_write_buffer(file->f_path.dentry, buffer, len);
|
2005-04-16 22:20:36 +00:00
|
|
|
if (len > 0)
|
|
|
|
*ppos += len;
|
2007-07-26 11:03:54 +00:00
|
|
|
mutex_unlock(&buffer->mutex);
|
2005-04-16 22:20:36 +00:00
|
|
|
return len;
|
|
|
|
}
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
/**
|
|
|
|
* sysfs_get_open_dirent - get or create sysfs_open_dirent
|
|
|
|
* @sd: target sysfs_dirent
|
|
|
|
* @buffer: sysfs_buffer for this instance of open
|
|
|
|
*
|
|
|
|
* If @sd->s_attr.open exists, increment its reference count;
|
|
|
|
* otherwise, create one. @buffer is chained to the buffers
|
|
|
|
* list.
|
|
|
|
*
|
|
|
|
* LOCKING:
|
|
|
|
* Kernel thread context (may sleep).
|
|
|
|
*
|
|
|
|
* RETURNS:
|
|
|
|
* 0 on success, -errno on failure.
|
|
|
|
*/
|
|
|
|
static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
|
|
|
|
struct sysfs_buffer *buffer)
|
|
|
|
{
|
|
|
|
struct sysfs_open_dirent *od, *new_od = NULL;
|
|
|
|
|
|
|
|
retry:
|
|
|
|
spin_lock(&sysfs_open_dirent_lock);
|
|
|
|
|
|
|
|
if (!sd->s_attr.open && new_od) {
|
|
|
|
sd->s_attr.open = new_od;
|
|
|
|
new_od = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
od = sd->s_attr.open;
|
|
|
|
if (od) {
|
|
|
|
atomic_inc(&od->refcnt);
|
|
|
|
list_add_tail(&buffer->list, &od->buffers);
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_unlock(&sysfs_open_dirent_lock);
|
|
|
|
|
|
|
|
if (od) {
|
|
|
|
kfree(new_od);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* not there, initialize a new one and retry */
|
|
|
|
new_od = kmalloc(sizeof(*new_od), GFP_KERNEL);
|
|
|
|
if (!new_od)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
atomic_set(&new_od->refcnt, 0);
|
2007-09-20 07:05:12 +00:00
|
|
|
atomic_set(&new_od->event, 1);
|
|
|
|
init_waitqueue_head(&new_od->poll);
|
2007-09-20 07:05:12 +00:00
|
|
|
INIT_LIST_HEAD(&new_od->buffers);
|
|
|
|
goto retry;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sysfs_put_open_dirent - put sysfs_open_dirent
|
|
|
|
* @sd: target sysfs_dirent
|
|
|
|
* @buffer: associated sysfs_buffer
|
|
|
|
*
|
|
|
|
* Put @sd->s_attr.open and unlink @buffer from the buffers list.
|
|
|
|
* If reference count reaches zero, disassociate and free it.
|
|
|
|
*
|
|
|
|
* LOCKING:
|
|
|
|
* None.
|
|
|
|
*/
|
|
|
|
static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
|
|
|
|
struct sysfs_buffer *buffer)
|
|
|
|
{
|
|
|
|
struct sysfs_open_dirent *od = sd->s_attr.open;
|
|
|
|
|
|
|
|
spin_lock(&sysfs_open_dirent_lock);
|
|
|
|
|
|
|
|
list_del(&buffer->list);
|
|
|
|
if (atomic_dec_and_test(&od->refcnt))
|
|
|
|
sd->s_attr.open = NULL;
|
|
|
|
else
|
|
|
|
od = NULL;
|
|
|
|
|
|
|
|
spin_unlock(&sysfs_open_dirent_lock);
|
|
|
|
|
|
|
|
kfree(od);
|
|
|
|
}
|
|
|
|
|
2006-12-20 09:52:44 +00:00
|
|
|
static int sysfs_open_file(struct inode *inode, struct file *file)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-06-13 18:45:15 +00:00
|
|
|
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
|
2007-09-20 07:05:11 +00:00
|
|
|
struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
|
2007-11-02 12:47:53 +00:00
|
|
|
struct sysfs_buffer *buffer;
|
|
|
|
struct sysfs_ops *ops;
|
|
|
|
int error = -EACCES;
|
2007-08-24 23:11:54 +00:00
|
|
|
char *p;
|
|
|
|
|
|
|
|
p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file));
|
|
|
|
if (p)
|
|
|
|
memmove(last_sysfs_file, p, strlen(p) + 1);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
/* need attr_sd for attr and ops, its parent for kobj */
|
|
|
|
if (!sysfs_get_active_two(attr_sd))
|
|
|
|
return -ENODEV;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-11-02 12:47:53 +00:00
|
|
|
/* every kobject with an attribute needs a ktype assigned */
|
|
|
|
if (kobj->ktype && kobj->ktype->sysfs_ops)
|
2005-04-16 22:20:36 +00:00
|
|
|
ops = kobj->ktype->sysfs_ops;
|
2007-11-02 12:47:53 +00:00
|
|
|
else {
|
2008-07-26 02:45:41 +00:00
|
|
|
WARN(1, KERN_ERR "missing sysfs attribute operations for "
|
2007-11-02 12:47:53 +00:00
|
|
|
"kobject: %s\n", kobject_name(kobj));
|
2007-06-13 18:45:17 +00:00
|
|
|
goto err_out;
|
2007-11-02 12:47:53 +00:00
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
/* File needs write support.
|
|
|
|
* The inode's perms must say it's ok,
|
|
|
|
* and we must have a store method.
|
|
|
|
*/
|
|
|
|
if (file->f_mode & FMODE_WRITE) {
|
|
|
|
if (!(inode->i_mode & S_IWUGO) || !ops->store)
|
2007-06-13 18:45:17 +00:00
|
|
|
goto err_out;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* File needs read support.
|
|
|
|
* The inode's perms must say it's ok, and we there
|
|
|
|
* must be a show method for it.
|
|
|
|
*/
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
|
|
if (!(inode->i_mode & S_IRUGO) || !ops->show)
|
2007-06-13 18:45:17 +00:00
|
|
|
goto err_out;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* No error? Great, allocate a buffer for the file, and store it
|
|
|
|
* it in file->private_data for easy access.
|
|
|
|
*/
|
2007-06-13 18:45:16 +00:00
|
|
|
error = -ENOMEM;
|
2006-02-22 10:18:15 +00:00
|
|
|
buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
|
2007-06-13 18:45:16 +00:00
|
|
|
if (!buffer)
|
2007-06-13 18:45:17 +00:00
|
|
|
goto err_out;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-07-26 11:03:54 +00:00
|
|
|
mutex_init(&buffer->mutex);
|
2007-06-13 18:45:16 +00:00
|
|
|
buffer->needs_read_fill = 1;
|
|
|
|
buffer->ops = ops;
|
|
|
|
file->private_data = buffer;
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
/* make sure we have open dirent struct */
|
|
|
|
error = sysfs_get_open_dirent(attr_sd, buffer);
|
|
|
|
if (error)
|
|
|
|
goto err_free;
|
|
|
|
|
2007-09-20 07:05:10 +00:00
|
|
|
/* open succeeded, put active references */
|
2007-06-13 18:45:16 +00:00
|
|
|
sysfs_put_active_two(attr_sd);
|
|
|
|
return 0;
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
err_free:
|
|
|
|
kfree(buffer);
|
2007-06-13 18:45:17 +00:00
|
|
|
err_out:
|
2007-06-13 18:45:16 +00:00
|
|
|
sysfs_put_active_two(attr_sd);
|
2005-04-16 22:20:36 +00:00
|
|
|
return error;
|
|
|
|
}
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
static int sysfs_release(struct inode *inode, struct file *filp)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2007-09-20 07:05:12 +00:00
|
|
|
struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
|
2007-06-13 18:45:16 +00:00
|
|
|
struct sysfs_buffer *buffer = filp->private_data;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
sysfs_put_open_dirent(sd, buffer);
|
|
|
|
|
2007-09-20 07:05:10 +00:00
|
|
|
if (buffer->page)
|
|
|
|
free_page((unsigned long)buffer->page);
|
|
|
|
kfree(buffer);
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2006-03-20 06:53:53 +00:00
|
|
|
/* Sysfs attribute files are pollable. The idea is that you read
|
|
|
|
* the content and then you use 'poll' or 'select' to wait for
|
|
|
|
* the content to change. When the content changes (assuming the
|
|
|
|
* manager for the kobject supports notification), poll will
|
|
|
|
* return POLLERR|POLLPRI, and select will return the fd whether
|
|
|
|
* it is waiting for read, write, or exceptions.
|
|
|
|
* Once poll/select indicates that the value has changed, you
|
2008-04-07 22:35:01 +00:00
|
|
|
* need to close and re-open the file, or seek to 0 and read again.
|
2006-03-20 06:53:53 +00:00
|
|
|
* Reminder: this only works for attributes which actively support
|
|
|
|
* it, and it is not possible to test an attribute from userspace
|
2007-08-10 20:51:07 +00:00
|
|
|
* to see if it supports poll (Neither 'poll' nor 'select' return
|
2006-03-20 06:53:53 +00:00
|
|
|
* an appropriate error code). When in doubt, set a suitable timeout value.
|
|
|
|
*/
|
|
|
|
static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
|
|
|
|
{
|
|
|
|
struct sysfs_buffer * buffer = filp->private_data;
|
2007-06-13 18:45:16 +00:00
|
|
|
struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
|
2007-09-20 07:05:12 +00:00
|
|
|
struct sysfs_open_dirent *od = attr_sd->s_attr.open;
|
2007-06-13 18:45:16 +00:00
|
|
|
|
|
|
|
/* need parent for the kobj, grab both */
|
|
|
|
if (!sysfs_get_active_two(attr_sd))
|
|
|
|
goto trigger;
|
2006-03-20 06:53:53 +00:00
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
poll_wait(filp, &od->poll, wait);
|
2006-03-20 06:53:53 +00:00
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
sysfs_put_active_two(attr_sd);
|
|
|
|
|
2007-09-20 07:05:12 +00:00
|
|
|
if (buffer->event != atomic_read(&od->event))
|
2007-06-13 18:45:16 +00:00
|
|
|
goto trigger;
|
2006-03-20 06:53:53 +00:00
|
|
|
|
2007-06-13 18:45:16 +00:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
trigger:
|
|
|
|
buffer->needs_read_fill = 1;
|
|
|
|
return POLLERR|POLLPRI;
|
2006-03-20 06:53:53 +00:00
|
|
|
}
|
|
|
|
|
2008-07-15 22:58:04 +00:00
|
|
|
void sysfs_notify_dirent(struct sysfs_dirent *sd)
|
|
|
|
{
|
|
|
|
struct sysfs_open_dirent *od;
|
|
|
|
|
|
|
|
spin_lock(&sysfs_open_dirent_lock);
|
|
|
|
|
|
|
|
od = sd->s_attr.open;
|
|
|
|
if (od) {
|
|
|
|
atomic_inc(&od->event);
|
|
|
|
wake_up_interruptible(&od->poll);
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_unlock(&sysfs_open_dirent_lock);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_notify_dirent);
|
|
|
|
|
2007-06-13 19:27:25 +00:00
|
|
|
void sysfs_notify(struct kobject *k, char *dir, char *attr)
|
2006-03-20 06:53:53 +00:00
|
|
|
{
|
2007-06-13 19:27:25 +00:00
|
|
|
struct sysfs_dirent *sd = k->sd;
|
2006-03-20 06:53:53 +00:00
|
|
|
|
2007-06-13 19:27:25 +00:00
|
|
|
mutex_lock(&sysfs_mutex);
|
|
|
|
|
|
|
|
if (sd && dir)
|
|
|
|
sd = sysfs_find_dirent(sd, dir);
|
|
|
|
if (sd && attr)
|
|
|
|
sd = sysfs_find_dirent(sd, attr);
|
2008-07-15 22:58:04 +00:00
|
|
|
if (sd)
|
|
|
|
sysfs_notify_dirent(sd);
|
2007-06-13 19:27:25 +00:00
|
|
|
|
|
|
|
mutex_unlock(&sysfs_mutex);
|
2006-03-20 06:53:53 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_notify);
|
|
|
|
|
2006-03-28 09:56:42 +00:00
|
|
|
const struct file_operations sysfs_file_operations = {
|
2005-04-16 22:20:36 +00:00
|
|
|
.read = sysfs_read_file,
|
|
|
|
.write = sysfs_write_file,
|
|
|
|
.llseek = generic_file_llseek,
|
|
|
|
.open = sysfs_open_file,
|
|
|
|
.release = sysfs_release,
|
2006-03-20 06:53:53 +00:00
|
|
|
.poll = sysfs_poll,
|
2005-04-16 22:20:36 +00:00
|
|
|
};
|
|
|
|
|
2008-03-21 01:47:52 +00:00
|
|
|
int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
|
|
|
|
const struct attribute *attr, int type, mode_t amode)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2008-03-21 01:47:52 +00:00
|
|
|
umode_t mode = (amode & S_IALLUGO) | S_IFREG;
|
2007-06-13 19:27:24 +00:00
|
|
|
struct sysfs_addrm_cxt acxt;
|
2007-06-13 18:45:14 +00:00
|
|
|
struct sysfs_dirent *sd;
|
2007-08-02 12:38:03 +00:00
|
|
|
int rc;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-06-13 19:27:23 +00:00
|
|
|
sd = sysfs_new_dirent(attr->name, mode, type);
|
|
|
|
if (!sd)
|
|
|
|
return -ENOMEM;
|
2007-09-20 07:05:11 +00:00
|
|
|
sd->s_attr.attr = (void *)attr;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-06-13 19:27:24 +00:00
|
|
|
sysfs_addrm_start(&acxt, dir_sd);
|
2007-08-02 12:38:03 +00:00
|
|
|
rc = sysfs_add_one(&acxt, sd);
|
|
|
|
sysfs_addrm_finish(&acxt);
|
2007-06-13 18:45:14 +00:00
|
|
|
|
2007-08-02 12:38:03 +00:00
|
|
|
if (rc)
|
2007-07-18 07:38:11 +00:00
|
|
|
sysfs_put(sd);
|
2007-06-13 19:27:23 +00:00
|
|
|
|
2007-08-02 12:38:03 +00:00
|
|
|
return rc;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2008-03-21 01:47:52 +00:00
|
|
|
int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,
|
|
|
|
int type)
|
|
|
|
{
|
|
|
|
return sysfs_add_file_mode(dir_sd, attr, type, attr->mode);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/**
|
|
|
|
* sysfs_create_file - create an attribute file for an object.
|
|
|
|
* @kobj: object we're creating for.
|
2007-10-20 01:14:32 +00:00
|
|
|
* @attr: attribute descriptor.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
|
|
|
|
{
|
2007-06-13 19:27:22 +00:00
|
|
|
BUG_ON(!kobj || !kobj->sd || !attr);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2007-06-13 19:27:22 +00:00
|
|
|
return sysfs_add_file(kobj->sd, attr, SYSFS_KOBJ_ATTR);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2007-02-20 20:02:44 +00:00
|
|
|
/**
|
|
|
|
* sysfs_add_file_to_group - add an attribute file to a pre-existing group.
|
|
|
|
* @kobj: object we're acting for.
|
|
|
|
* @attr: attribute descriptor.
|
|
|
|
* @group: group name.
|
|
|
|
*/
|
|
|
|
int sysfs_add_file_to_group(struct kobject *kobj,
|
|
|
|
const struct attribute *attr, const char *group)
|
|
|
|
{
|
2007-06-13 19:27:22 +00:00
|
|
|
struct sysfs_dirent *dir_sd;
|
2007-02-20 20:02:44 +00:00
|
|
|
int error;
|
|
|
|
|
2008-01-03 00:44:05 +00:00
|
|
|
if (group)
|
|
|
|
dir_sd = sysfs_get_dirent(kobj->sd, group);
|
|
|
|
else
|
|
|
|
dir_sd = sysfs_get(kobj->sd);
|
|
|
|
|
2007-06-13 19:27:22 +00:00
|
|
|
if (!dir_sd)
|
|
|
|
return -ENOENT;
|
|
|
|
|
|
|
|
error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR);
|
|
|
|
sysfs_put(dir_sd);
|
|
|
|
|
2007-02-20 20:02:44 +00:00
|
|
|
return error;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
|
|
|
|
|
2005-04-19 04:57:32 +00:00
|
|
|
/**
|
|
|
|
* sysfs_chmod_file - update the modified mode value on an object attribute.
|
|
|
|
* @kobj: object we're acting for.
|
|
|
|
* @attr: attribute descriptor.
|
|
|
|
* @mode: file permissions.
|
|
|
|
*
|
|
|
|
*/
|
|
|
|
int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
|
|
|
|
{
|
2007-06-13 19:27:25 +00:00
|
|
|
struct sysfs_dirent *victim_sd = NULL;
|
|
|
|
struct dentry *victim = NULL;
|
2005-07-29 19:13:35 +00:00
|
|
|
struct inode * inode;
|
|
|
|
struct iattr newattrs;
|
2007-06-13 19:27:25 +00:00
|
|
|
int rc;
|
|
|
|
|
|
|
|
rc = -ENOENT;
|
|
|
|
victim_sd = sysfs_get_dirent(kobj->sd, attr->name);
|
|
|
|
if (!victim_sd)
|
|
|
|
goto out;
|
|
|
|
|
2007-08-20 12:36:30 +00:00
|
|
|
mutex_lock(&sysfs_rename_mutex);
|
2007-06-13 19:27:25 +00:00
|
|
|
victim = sysfs_get_dentry(victim_sd);
|
2007-08-20 12:36:30 +00:00
|
|
|
mutex_unlock(&sysfs_rename_mutex);
|
2007-06-13 19:27:25 +00:00
|
|
|
if (IS_ERR(victim)) {
|
|
|
|
rc = PTR_ERR(victim);
|
|
|
|
victim = NULL;
|
|
|
|
goto out;
|
2005-04-19 04:57:32 +00:00
|
|
|
}
|
|
|
|
|
2007-06-13 19:27:25 +00:00
|
|
|
inode = victim->d_inode;
|
2007-09-20 07:05:10 +00:00
|
|
|
|
2007-06-13 19:27:25 +00:00
|
|
|
mutex_lock(&inode->i_mutex);
|
2007-09-20 07:05:10 +00:00
|
|
|
|
2007-06-13 19:27:25 +00:00
|
|
|
newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
|
|
|
|
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
|
2008-06-16 11:46:47 +00:00
|
|
|
newattrs.ia_ctime = current_fs_time(inode->i_sb);
|
|
|
|
rc = sysfs_setattr(victim, &newattrs);
|
2007-09-20 07:05:10 +00:00
|
|
|
|
|
|
|
if (rc == 0) {
|
2008-06-16 11:46:47 +00:00
|
|
|
fsnotify_change(victim, newattrs.ia_valid);
|
2007-09-20 07:05:10 +00:00
|
|
|
mutex_lock(&sysfs_mutex);
|
|
|
|
victim_sd->s_mode = newattrs.ia_mode;
|
|
|
|
mutex_unlock(&sysfs_mutex);
|
|
|
|
}
|
|
|
|
|
2007-06-13 19:27:25 +00:00
|
|
|
mutex_unlock(&inode->i_mutex);
|
|
|
|
out:
|
|
|
|
dput(victim);
|
|
|
|
sysfs_put(victim_sd);
|
|
|
|
return rc;
|
2005-04-19 04:57:32 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_chmod_file);
|
|
|
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/**
|
|
|
|
* sysfs_remove_file - remove an object attribute.
|
|
|
|
* @kobj: object we're acting for.
|
|
|
|
* @attr: attribute descriptor.
|
|
|
|
*
|
|
|
|
* Hash the attribute name and kill the victim.
|
|
|
|
*/
|
|
|
|
|
|
|
|
void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr)
|
|
|
|
{
|
2007-06-13 19:27:22 +00:00
|
|
|
sysfs_hash_and_remove(kobj->sd, attr->name);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2007-02-20 20:02:44 +00:00
|
|
|
/**
|
|
|
|
* sysfs_remove_file_from_group - remove an attribute file from a group.
|
|
|
|
* @kobj: object we're acting for.
|
|
|
|
* @attr: attribute descriptor.
|
|
|
|
* @group: group name.
|
|
|
|
*/
|
|
|
|
void sysfs_remove_file_from_group(struct kobject *kobj,
|
|
|
|
const struct attribute *attr, const char *group)
|
|
|
|
{
|
2007-06-13 19:27:22 +00:00
|
|
|
struct sysfs_dirent *dir_sd;
|
2007-02-20 20:02:44 +00:00
|
|
|
|
2008-01-03 00:44:05 +00:00
|
|
|
if (group)
|
|
|
|
dir_sd = sysfs_get_dirent(kobj->sd, group);
|
|
|
|
else
|
|
|
|
dir_sd = sysfs_get(kobj->sd);
|
2007-06-13 19:27:22 +00:00
|
|
|
if (dir_sd) {
|
|
|
|
sysfs_hash_and_remove(dir_sd, attr->name);
|
|
|
|
sysfs_put(dir_sd);
|
2007-02-20 20:02:44 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
|
|
|
|
|
2007-03-15 19:50:34 +00:00
|
|
|
struct sysfs_schedule_callback_struct {
|
|
|
|
struct kobject *kobj;
|
|
|
|
void (*func)(void *);
|
|
|
|
void *data;
|
2007-04-26 07:12:04 +00:00
|
|
|
struct module *owner;
|
2007-03-15 19:50:34 +00:00
|
|
|
struct work_struct work;
|
|
|
|
};
|
|
|
|
|
|
|
|
static void sysfs_schedule_callback_work(struct work_struct *work)
|
|
|
|
{
|
|
|
|
struct sysfs_schedule_callback_struct *ss = container_of(work,
|
|
|
|
struct sysfs_schedule_callback_struct, work);
|
|
|
|
|
|
|
|
(ss->func)(ss->data);
|
|
|
|
kobject_put(ss->kobj);
|
2007-04-26 07:12:04 +00:00
|
|
|
module_put(ss->owner);
|
2007-03-15 19:50:34 +00:00
|
|
|
kfree(ss);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sysfs_schedule_callback - helper to schedule a callback for a kobject
|
|
|
|
* @kobj: object we're acting for.
|
|
|
|
* @func: callback function to invoke later.
|
|
|
|
* @data: argument to pass to @func.
|
2007-04-26 07:12:04 +00:00
|
|
|
* @owner: module owning the callback code
|
2007-03-15 19:50:34 +00:00
|
|
|
*
|
|
|
|
* sysfs attribute methods must not unregister themselves or their parent
|
|
|
|
* kobject (which would amount to the same thing). Attempts to do so will
|
|
|
|
* deadlock, since unregistration is mutually exclusive with driver
|
|
|
|
* callbacks.
|
|
|
|
*
|
|
|
|
* Instead methods can call this routine, which will attempt to allocate
|
|
|
|
* and schedule a workqueue request to call back @func with @data as its
|
|
|
|
* argument in the workqueue's process context. @kobj will be pinned
|
|
|
|
* until @func returns.
|
|
|
|
*
|
|
|
|
* Returns 0 if the request was submitted, -ENOMEM if storage could not
|
2007-04-26 07:12:04 +00:00
|
|
|
* be allocated, -ENODEV if a reference to @owner isn't available.
|
2007-03-15 19:50:34 +00:00
|
|
|
*/
|
|
|
|
int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
|
2007-04-26 07:12:04 +00:00
|
|
|
void *data, struct module *owner)
|
2007-03-15 19:50:34 +00:00
|
|
|
{
|
|
|
|
struct sysfs_schedule_callback_struct *ss;
|
|
|
|
|
2007-04-26 07:12:04 +00:00
|
|
|
if (!try_module_get(owner))
|
|
|
|
return -ENODEV;
|
2007-03-15 19:50:34 +00:00
|
|
|
ss = kmalloc(sizeof(*ss), GFP_KERNEL);
|
2007-04-26 07:12:04 +00:00
|
|
|
if (!ss) {
|
|
|
|
module_put(owner);
|
2007-03-15 19:50:34 +00:00
|
|
|
return -ENOMEM;
|
2007-04-26 07:12:04 +00:00
|
|
|
}
|
2007-03-15 19:50:34 +00:00
|
|
|
kobject_get(kobj);
|
|
|
|
ss->kobj = kobj;
|
|
|
|
ss->func = func;
|
|
|
|
ss->data = data;
|
2007-04-26 07:12:04 +00:00
|
|
|
ss->owner = owner;
|
2007-03-15 19:50:34 +00:00
|
|
|
INIT_WORK(&ss->work, sysfs_schedule_callback_work);
|
|
|
|
schedule_work(&ss->work);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_schedule_callback);
|
|
|
|
|
2007-02-20 20:02:44 +00:00
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
EXPORT_SYMBOL_GPL(sysfs_create_file);
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_remove_file);
|