/*
- * bin.c - binary file operations for sysfs.
+ * fs/sysfs/bin.c - sysfs binary file implementation
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Matthew Wilcox
* Copyright (c) 2004 Silicon Graphics, Inc.
+ * 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.
*/
#undef DEBUG
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/mutex.h>
#include <asm/uaccess.h>
-#include <asm/semaphore.h>
#include "sysfs.h"
struct bin_buffer {
struct mutex mutex;
void *buffer;
+ int mmapped;
};
static int
fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
{
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
- struct kobject * kobj = to_kobj(dentry->d_parent);
+ struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
+ struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
+ int rc;
+
+ /* need attr_sd for attr, its parent for kobj */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
+
+ rc = -EIO;
+ if (attr->read)
+ rc = attr->read(kobj, attr, buffer, off, count);
- if (!attr->read)
- return -EIO;
+ sysfs_put_active_two(attr_sd);
- return attr->read(kobj, buffer, off, count);
+ return rc;
}
static ssize_t
flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
{
struct sysfs_dirent *attr_sd = dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
- struct kobject *kobj = to_kobj(dentry->d_parent);
+ struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
+ struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
+ int rc;
+
+ /* need attr_sd for attr, its parent for kobj */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
+
+ rc = -EIO;
+ if (attr->write)
+ rc = attr->write(kobj, attr, buffer, offset, count);
- if (!attr->write)
- return -EIO;
+ sysfs_put_active_two(attr_sd);
- return attr->write(kobj, buffer, offset, count);
+ return rc;
}
static ssize_t write(struct file *file, const char __user *userbuf,
{
struct bin_buffer *bb = file->private_data;
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
- struct kobject *kobj = to_kobj(file->f_path.dentry->d_parent);
+ struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
+ struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
int rc;
- if (!attr->mmap)
- return -EINVAL;
-
mutex_lock(&bb->mutex);
- rc = attr->mmap(kobj, attr, vma);
+
+ /* need attr_sd for attr, its parent for kobj */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
+
+ rc = -EINVAL;
+ if (attr->mmap)
+ rc = attr->mmap(kobj, attr, vma);
+
+ if (rc == 0 && !bb->mmapped)
+ bb->mmapped = 1;
+ else
+ sysfs_put_active_two(attr_sd);
+
mutex_unlock(&bb->mutex);
return rc;
static int open(struct inode * inode, struct file * file)
{
- struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+ struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
struct bin_buffer *bb = NULL;
- int error = -EINVAL;
-
- if (!kobj || !attr)
- goto Done;
+ int error;
- /* Grab the module reference for this attribute if we have one */
- error = -ENODEV;
- if (!try_module_get(attr->attr.owner))
- goto Done;
+ /* binary file operations requires both @sd and its parent */
+ if (!sysfs_get_active_two(attr_sd))
+ return -ENODEV;
error = -EACCES;
if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
- goto Error;
+ goto err_out;
if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
- goto Error;
+ goto err_out;
error = -ENOMEM;
bb = kzalloc(sizeof(*bb), GFP_KERNEL);
if (!bb)
- goto Error;
+ goto err_out;
bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!bb->buffer)
- goto Error;
+ goto err_out;
mutex_init(&bb->mutex);
file->private_data = bb;
- error = 0;
- goto Done;
+ /* open succeeded, put active references */
+ sysfs_put_active_two(attr_sd);
+ return 0;
- Error:
+ err_out:
+ sysfs_put_active_two(attr_sd);
kfree(bb);
- module_put(attr->attr.owner);
- Done:
- if (error)
- kobject_put(kobj);
return error;
}
static int release(struct inode * inode, struct file * file)
{
- struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
struct bin_buffer *bb = file->private_data;
- kobject_put(kobj);
- module_put(attr->attr.owner);
+ if (bb->mmapped)
+ sysfs_put_active_two(attr_sd);
kfree(bb->buffer);
kfree(bb);
return 0;
int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
{
- BUG_ON(!kobj || !kobj->dentry || !attr);
+ BUG_ON(!kobj || !kobj->sd || !attr);
- return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
+ return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
}
void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
{
- if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
- printk(KERN_ERR "%s: "
- "bad dentry or inode or no such file: \"%s\"\n",
- __FUNCTION__, attr->attr.name);
- dump_stack();
- }
+ sysfs_hash_and_remove(kobj->sd, attr->attr.name);
}
EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
projects / linux-2.6 / blobdiff