/* * bin.c - binary file operations for sysfs. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Matthew Wilcox * Copyright (c) 2004 Silicon Graphics, Inc. */ #undef DEBUG #include <linux/errno.h> #include <linux/fs.h> #include <linux/kobject.h> #include <linux/module.h> #include <linux/slab.h> #include <asm/uaccess.h> #include "sysfs.h" static int fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) { struct bin_attribute * attr = to_bin_attr(dentry); struct kobject * kobj = to_kobj(dentry->d_parent); if (!attr->read) return -EIO; return attr->read(kobj, buffer, off, count); } static ssize_t read(struct file * file, char __user * userbuf, size_t count, loff_t * off) { char *buffer = file->private_data; struct dentry *dentry = file->f_dentry; int size = dentry->d_inode->i_size; loff_t offs = *off; int ret; if (count > PAGE_SIZE) count = PAGE_SIZE; if (size) { if (offs > size) return 0; if (offs + count > size) count = size - offs; } ret = fill_read(dentry, buffer, offs, count); if (ret < 0) return ret; count = ret; if (copy_to_user(userbuf, buffer, count)) return -EFAULT; pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count); *off = offs + count; return count; } static int flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) { struct bin_attribute *attr = to_bin_attr(dentry); struct kobject *kobj = to_kobj(dentry->d_parent); if (!attr->write) return -EIO; return attr->write(kobj, buffer, offset, count); } static ssize_t write(struct file * file, const char __user * userbuf, size_t count, loff_t * off) { char *buffer = file->private_data; struct dentry *dentry = file->f_dentry; int size = dentry->d_inode->i_size; loff_t offs = *off; if (count > PAGE_SIZE) count = PAGE_SIZE; if (size) { if (offs > size) return 0; if (offs + count > size) count = size - offs; } if (copy_from_user(buffer, userbuf, count)) return -EFAULT; count = flush_write(dentry, buffer, offs, count); if (count > 0) *off = offs + count; return count; } static int mmap(struct file *file, struct vm_area_struct *vma) { struct dentry *dentry = file->f_dentry; struct bin_attribute *attr = to_bin_attr(dentry); struct kobject *kobj = to_kobj(dentry->d_parent); if (!attr->mmap) return -EINVAL; return attr->mmap(kobj, attr, vma); } static int open(struct inode * inode, struct file * file) { struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent); struct bin_attribute * attr = to_bin_attr(file->f_dentry); int error = -EINVAL; if (!kobj || !attr) goto Done; /* Grab the module reference for this attribute if we have one */ error = -ENODEV; if (!try_module_get(attr->attr.owner)) goto Done; error = -EACCES; if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) goto Error; if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) goto Error; error = -ENOMEM; file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!file->private_data) goto Error; error = 0; goto Done; Error: module_put(attr->attr.owner); Done: if (error && kobj) kobject_put(kobj); return error; } static int release(struct inode * inode, struct file * file) { struct kobject * kobj = to_kobj(file->f_dentry->d_parent); struct bin_attribute * attr = to_bin_attr(file->f_dentry); u8 * buffer = file->private_data; if (kobj) kobject_put(kobj); module_put(attr->attr.owner); kfree(buffer); return 0; } const struct file_operations bin_fops = { .read = read, .write = write, .mmap = mmap, .llseek = generic_file_llseek, .open = open, .release = release, }; /** * sysfs_create_bin_file - create binary file for object. * @kobj: object. * @attr: attribute descriptor. * */ int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr) { BUG_ON(!kobj || !kobj->dentry || !attr); return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR); } /** * sysfs_remove_bin_file - remove binary file for object. * @kobj: object. * @attr: attribute descriptor. * */ int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr) { sysfs_hash_and_remove(kobj->dentry,attr->attr.name); return 0; } EXPORT_SYMBOL_GPL(sysfs_create_bin_file); EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);