+++ /dev/null
-/*
- * 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/errno.h>
-#include <linux/fs.h>
-#include <linux/kernel.h>
-#include <linux/kobject.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/mutex.h>
-#include <linux/mm.h>
-#include <linux/uaccess.h>
-
-#include "sysfs.h"
-
-/*
- * There's one bin_buffer for each open file.
- *
- * filp->private_data points to bin_buffer and
- * sysfs_dirent->s_bin_attr.buffers points to a the bin_buffer s
- * sysfs_dirent->s_bin_attr.buffers is protected by sysfs_bin_lock
- */
-static DEFINE_MUTEX(sysfs_bin_lock);
-
-struct bin_buffer {
- struct mutex mutex;
- void *buffer;
- int mmapped;
- const struct vm_operations_struct *vm_ops;
- struct file *file;
- struct hlist_node list;
-};
-
-static ssize_t
-read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
-{
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
- struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
- struct bin_buffer *bb = file->private_data;
- int size = file_inode(file)->i_size;
- loff_t offs = *off;
- int count = min_t(size_t, bytes, PAGE_SIZE);
- char *buf;
-
- if (!bytes)
- return 0;
-
- if (size) {
- if (offs > size)
- return 0;
- if (offs + count > size)
- count = size - offs;
- }
-
- buf = kmalloc(count, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- /* need attr_sd for attr, its parent for kobj */
- mutex_lock(&bb->mutex);
- if (!sysfs_get_active(attr_sd)) {
- count = -ENODEV;
- mutex_unlock(&bb->mutex);
- goto out_free;
- }
-
- if (attr->read)
- count = attr->read(file, kobj, attr, buf, offs, count);
- else
- count = -EIO;
-
- sysfs_put_active(attr_sd);
- mutex_unlock(&bb->mutex);
-
- if (count < 0)
- goto out_free;
-
- if (copy_to_user(userbuf, buf, count)) {
- count = -EFAULT;
- goto out_free;
- }
-
- pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
-
- *off = offs + count;
-
- out_free:
- kfree(buf);
- return count;
-}
-
-static int
-flush_write(struct file *file, char *buffer, loff_t offset, size_t count)
-{
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- 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(attr_sd))
- return -ENODEV;
-
- rc = -EIO;
- if (attr->write)
- rc = attr->write(file, kobj, attr, buffer, offset, count);
-
- sysfs_put_active(attr_sd);
-
- return rc;
-}
-
-static ssize_t write(struct file *file, const char __user *userbuf,
- size_t bytes, loff_t *off)
-{
- struct bin_buffer *bb = file->private_data;
- int size = file_inode(file)->i_size;
- loff_t offs = *off;
- int count = min_t(size_t, bytes, PAGE_SIZE);
- char *temp;
-
- if (!bytes)
- return 0;
-
- if (size) {
- if (offs > size)
- return 0;
- if (offs + count > size)
- count = size - offs;
- }
-
- temp = memdup_user(userbuf, count);
- if (IS_ERR(temp))
- return PTR_ERR(temp);
-
- mutex_lock(&bb->mutex);
-
- memcpy(bb->buffer, temp, count);
-
- count = flush_write(file, bb->buffer, offs, count);
- mutex_unlock(&bb->mutex);
-
- if (count > 0)
- *off = offs + count;
-
- kfree(temp);
- return count;
-}
-
-static void bin_vma_open(struct vm_area_struct *vma)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
-
- if (!bb->vm_ops)
- return;
-
- if (!sysfs_get_active(attr_sd))
- return;
-
- if (bb->vm_ops->open)
- bb->vm_ops->open(vma);
-
- sysfs_put_active(attr_sd);
-}
-
-static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- int ret;
-
- if (!bb->vm_ops)
- return VM_FAULT_SIGBUS;
-
- if (!sysfs_get_active(attr_sd))
- return VM_FAULT_SIGBUS;
-
- ret = VM_FAULT_SIGBUS;
- if (bb->vm_ops->fault)
- ret = bb->vm_ops->fault(vma, vmf);
-
- sysfs_put_active(attr_sd);
- return ret;
-}
-
-static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- int ret;
-
- if (!bb->vm_ops)
- return VM_FAULT_SIGBUS;
-
- if (!sysfs_get_active(attr_sd))
- return VM_FAULT_SIGBUS;
-
- ret = 0;
- if (bb->vm_ops->page_mkwrite)
- ret = bb->vm_ops->page_mkwrite(vma, vmf);
- else
- file_update_time(file);
-
- sysfs_put_active(attr_sd);
- return ret;
-}
-
-static int bin_access(struct vm_area_struct *vma, unsigned long addr,
- void *buf, int len, int write)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- int ret;
-
- if (!bb->vm_ops)
- return -EINVAL;
-
- if (!sysfs_get_active(attr_sd))
- return -EINVAL;
-
- ret = -EINVAL;
- if (bb->vm_ops->access)
- ret = bb->vm_ops->access(vma, addr, buf, len, write);
-
- sysfs_put_active(attr_sd);
- return ret;
-}
-
-#ifdef CONFIG_NUMA
-static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- int ret;
-
- if (!bb->vm_ops)
- return 0;
-
- if (!sysfs_get_active(attr_sd))
- return -EINVAL;
-
- ret = 0;
- if (bb->vm_ops->set_policy)
- ret = bb->vm_ops->set_policy(vma, new);
-
- sysfs_put_active(attr_sd);
- return ret;
-}
-
-static struct mempolicy *bin_get_policy(struct vm_area_struct *vma,
- unsigned long addr)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- struct mempolicy *pol;
-
- if (!bb->vm_ops)
- return vma->vm_policy;
-
- if (!sysfs_get_active(attr_sd))
- return vma->vm_policy;
-
- pol = vma->vm_policy;
- if (bb->vm_ops->get_policy)
- pol = bb->vm_ops->get_policy(vma, addr);
-
- sysfs_put_active(attr_sd);
- return pol;
-}
-
-static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
- const nodemask_t *to, unsigned long flags)
-{
- struct file *file = vma->vm_file;
- struct bin_buffer *bb = file->private_data;
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- int ret;
-
- if (!bb->vm_ops)
- return 0;
-
- if (!sysfs_get_active(attr_sd))
- return 0;
-
- ret = 0;
- if (bb->vm_ops->migrate)
- ret = bb->vm_ops->migrate(vma, from, to, flags);
-
- sysfs_put_active(attr_sd);
- return ret;
-}
-#endif
-
-static const struct vm_operations_struct bin_vm_ops = {
- .open = bin_vma_open,
- .fault = bin_fault,
- .page_mkwrite = bin_page_mkwrite,
- .access = bin_access,
-#ifdef CONFIG_NUMA
- .set_policy = bin_set_policy,
- .get_policy = bin_get_policy,
- .migrate = bin_migrate,
-#endif
-};
-
-static int mmap(struct file *file, struct vm_area_struct *vma)
-{
- 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_bin_attr.bin_attr;
- struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
- int rc;
-
- mutex_lock(&bb->mutex);
-
- /* need attr_sd for attr, its parent for kobj */
- rc = -ENODEV;
- if (!sysfs_get_active(attr_sd))
- goto out_unlock;
-
- rc = -EINVAL;
- if (!attr->mmap)
- goto out_put;
-
- rc = attr->mmap(file, kobj, attr, vma);
- if (rc)
- goto out_put;
-
- /*
- * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup()
- * to satisfy versions of X which crash if the mmap fails: that
- * substitutes a new vm_file, and we don't then want bin_vm_ops.
- */
- if (vma->vm_file != file)
- goto out_put;
-
- rc = -EINVAL;
- if (bb->mmapped && bb->vm_ops != vma->vm_ops)
- goto out_put;
-
- /*
- * It is not possible to successfully wrap close.
- * So error if someone is trying to use close.
- */
- rc = -EINVAL;
- if (vma->vm_ops && vma->vm_ops->close)
- goto out_put;
-
- rc = 0;
- bb->mmapped = 1;
- bb->vm_ops = vma->vm_ops;
- vma->vm_ops = &bin_vm_ops;
-out_put:
- sysfs_put_active(attr_sd);
-out_unlock:
- mutex_unlock(&bb->mutex);
-
- return rc;
-}
-
-static int open(struct inode *inode, struct file *file)
-{
- struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
- struct bin_buffer *bb = NULL;
- int error;
-
- /* binary file operations requires both @sd and its parent */
- if (!sysfs_get_active(attr_sd))
- return -ENODEV;
-
- error = -EACCES;
- if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
- goto err_out;
- if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
- goto err_out;
-
- error = -ENOMEM;
- bb = kzalloc(sizeof(*bb), GFP_KERNEL);
- if (!bb)
- goto err_out;
-
- bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!bb->buffer)
- goto err_out;
-
- mutex_init(&bb->mutex);
- bb->file = file;
- file->private_data = bb;
-
- mutex_lock(&sysfs_bin_lock);
- hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers);
- mutex_unlock(&sysfs_bin_lock);
-
- /* open succeeded, put active references */
- sysfs_put_active(attr_sd);
- return 0;
-
- err_out:
- sysfs_put_active(attr_sd);
- kfree(bb);
- return error;
-}
-
-static int release(struct inode *inode, struct file *file)
-{
- struct bin_buffer *bb = file->private_data;
-
- mutex_lock(&sysfs_bin_lock);
- hlist_del(&bb->list);
- mutex_unlock(&sysfs_bin_lock);
-
- kfree(bb->buffer);
- kfree(bb);
- return 0;
-}
-
-const struct file_operations bin_fops = {
- .read = read,
- .write = write,
- .mmap = mmap,
- .llseek = generic_file_llseek,
- .open = open,
- .release = release,
-};
-
-
-void unmap_bin_file(struct sysfs_dirent *attr_sd)
-{
- struct bin_buffer *bb;
-
- if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR)
- return;
-
- mutex_lock(&sysfs_bin_lock);
-
- hlist_for_each_entry(bb, &attr_sd->s_bin_attr.buffers, list) {
- struct inode *inode = file_inode(bb->file);
-
- unmap_mapping_range(inode->i_mapping, 0, 0, 1);
- }
-
- mutex_unlock(&sysfs_bin_lock);
-}
-
-/**
- * sysfs_create_bin_file - create binary file for object.
- * @kobj: object.
- * @attr: attribute descriptor.
- */
-int sysfs_create_bin_file(struct kobject *kobj,
- const struct bin_attribute *attr)
-{
- BUG_ON(!kobj || !kobj->sd || !attr);
-
- return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
-}
-EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
-
-/**
- * sysfs_remove_bin_file - remove binary file for object.
- * @kobj: object.
- * @attr: attribute descriptor.
- */
-void sysfs_remove_bin_file(struct kobject *kobj,
- const struct bin_attribute *attr)
-{
- sysfs_hash_and_remove(kobj->sd, attr->attr.name, NULL);
-}
-EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
projects / linux-beck.git / commitdiff