mirror of https://gitee.com/openkylin/linux.git
512 lines
11 KiB
C
512 lines
11 KiB
C
/*
|
|
* dir.c - Operations for sysfs directories.
|
|
*/
|
|
|
|
#undef DEBUG
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kobject.h>
|
|
#include <linux/namei.h>
|
|
#include "sysfs.h"
|
|
|
|
DECLARE_RWSEM(sysfs_rename_sem);
|
|
|
|
static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
|
|
{
|
|
struct sysfs_dirent * sd = dentry->d_fsdata;
|
|
|
|
if (sd) {
|
|
BUG_ON(sd->s_dentry != dentry);
|
|
sd->s_dentry = NULL;
|
|
sysfs_put(sd);
|
|
}
|
|
iput(inode);
|
|
}
|
|
|
|
static struct dentry_operations sysfs_dentry_ops = {
|
|
.d_iput = sysfs_d_iput,
|
|
};
|
|
|
|
/*
|
|
* Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
|
|
*/
|
|
static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
|
|
void * element)
|
|
{
|
|
struct sysfs_dirent * sd;
|
|
|
|
sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL);
|
|
if (!sd)
|
|
return NULL;
|
|
|
|
memset(sd, 0, sizeof(*sd));
|
|
atomic_set(&sd->s_count, 1);
|
|
atomic_set(&sd->s_event, 0);
|
|
INIT_LIST_HEAD(&sd->s_children);
|
|
list_add(&sd->s_sibling, &parent_sd->s_children);
|
|
sd->s_element = element;
|
|
|
|
return sd;
|
|
}
|
|
|
|
/*
|
|
*
|
|
* Return -EEXIST if there is already a sysfs element with the same name for
|
|
* the same parent.
|
|
*
|
|
* called with parent inode's i_mutex held
|
|
*/
|
|
int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
|
|
const unsigned char *new)
|
|
{
|
|
struct sysfs_dirent * sd;
|
|
|
|
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
|
|
if (sd->s_element) {
|
|
const unsigned char *existing = sysfs_get_name(sd);
|
|
if (strcmp(existing, new))
|
|
continue;
|
|
else
|
|
return -EEXIST;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
|
|
void * element, umode_t mode, int type)
|
|
{
|
|
struct sysfs_dirent * sd;
|
|
|
|
sd = sysfs_new_dirent(parent_sd, element);
|
|
if (!sd)
|
|
return -ENOMEM;
|
|
|
|
sd->s_mode = mode;
|
|
sd->s_type = type;
|
|
sd->s_dentry = dentry;
|
|
if (dentry) {
|
|
dentry->d_fsdata = sysfs_get(sd);
|
|
dentry->d_op = &sysfs_dentry_ops;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int init_dir(struct inode * inode)
|
|
{
|
|
inode->i_op = &sysfs_dir_inode_operations;
|
|
inode->i_fop = &sysfs_dir_operations;
|
|
|
|
/* directory inodes start off with i_nlink == 2 (for "." entry) */
|
|
inode->i_nlink++;
|
|
return 0;
|
|
}
|
|
|
|
static int init_file(struct inode * inode)
|
|
{
|
|
inode->i_size = PAGE_SIZE;
|
|
inode->i_fop = &sysfs_file_operations;
|
|
return 0;
|
|
}
|
|
|
|
static int init_symlink(struct inode * inode)
|
|
{
|
|
inode->i_op = &sysfs_symlink_inode_operations;
|
|
return 0;
|
|
}
|
|
|
|
static int create_dir(struct kobject * k, struct dentry * p,
|
|
const char * n, struct dentry ** d)
|
|
{
|
|
int error;
|
|
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
|
|
|
|
mutex_lock(&p->d_inode->i_mutex);
|
|
*d = lookup_one_len(n, p, strlen(n));
|
|
if (!IS_ERR(*d)) {
|
|
if (sysfs_dirent_exist(p->d_fsdata, n))
|
|
error = -EEXIST;
|
|
else
|
|
error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
|
|
SYSFS_DIR);
|
|
if (!error) {
|
|
error = sysfs_create(*d, mode, init_dir);
|
|
if (!error) {
|
|
p->d_inode->i_nlink++;
|
|
(*d)->d_op = &sysfs_dentry_ops;
|
|
d_rehash(*d);
|
|
}
|
|
}
|
|
if (error && (error != -EEXIST)) {
|
|
struct sysfs_dirent *sd = (*d)->d_fsdata;
|
|
if (sd) {
|
|
list_del_init(&sd->s_sibling);
|
|
sysfs_put(sd);
|
|
}
|
|
d_drop(*d);
|
|
}
|
|
dput(*d);
|
|
} else
|
|
error = PTR_ERR(*d);
|
|
mutex_unlock(&p->d_inode->i_mutex);
|
|
return error;
|
|
}
|
|
|
|
|
|
int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
|
|
{
|
|
return create_dir(k,k->dentry,n,d);
|
|
}
|
|
|
|
/**
|
|
* sysfs_create_dir - create a directory for an object.
|
|
* @parent: parent parent object.
|
|
* @kobj: object we're creating directory for.
|
|
*/
|
|
|
|
int sysfs_create_dir(struct kobject * kobj)
|
|
{
|
|
struct dentry * dentry = NULL;
|
|
struct dentry * parent;
|
|
int error = 0;
|
|
|
|
BUG_ON(!kobj);
|
|
|
|
if (kobj->parent)
|
|
parent = kobj->parent->dentry;
|
|
else if (sysfs_mount && sysfs_mount->mnt_sb)
|
|
parent = sysfs_mount->mnt_sb->s_root;
|
|
else
|
|
return -EFAULT;
|
|
|
|
error = create_dir(kobj,parent,kobject_name(kobj),&dentry);
|
|
if (!error)
|
|
kobj->dentry = dentry;
|
|
return error;
|
|
}
|
|
|
|
/* attaches attribute's sysfs_dirent to the dentry corresponding to the
|
|
* attribute file
|
|
*/
|
|
static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
|
|
{
|
|
struct attribute * attr = NULL;
|
|
struct bin_attribute * bin_attr = NULL;
|
|
int (* init) (struct inode *) = NULL;
|
|
int error = 0;
|
|
|
|
if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
|
|
bin_attr = sd->s_element;
|
|
attr = &bin_attr->attr;
|
|
} else {
|
|
attr = sd->s_element;
|
|
init = init_file;
|
|
}
|
|
|
|
dentry->d_fsdata = sysfs_get(sd);
|
|
sd->s_dentry = dentry;
|
|
error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
|
|
if (error) {
|
|
sysfs_put(sd);
|
|
return error;
|
|
}
|
|
|
|
if (bin_attr) {
|
|
dentry->d_inode->i_size = bin_attr->size;
|
|
dentry->d_inode->i_fop = &bin_fops;
|
|
}
|
|
dentry->d_op = &sysfs_dentry_ops;
|
|
d_rehash(dentry);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
|
|
{
|
|
int err = 0;
|
|
|
|
dentry->d_fsdata = sysfs_get(sd);
|
|
sd->s_dentry = dentry;
|
|
err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
|
|
if (!err) {
|
|
dentry->d_op = &sysfs_dentry_ops;
|
|
d_rehash(dentry);
|
|
} else
|
|
sysfs_put(sd);
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
|
|
struct nameidata *nd)
|
|
{
|
|
struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
|
|
struct sysfs_dirent * sd;
|
|
int err = 0;
|
|
|
|
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
|
|
if (sd->s_type & SYSFS_NOT_PINNED) {
|
|
const unsigned char * name = sysfs_get_name(sd);
|
|
|
|
if (strcmp(name, dentry->d_name.name))
|
|
continue;
|
|
|
|
if (sd->s_type & SYSFS_KOBJ_LINK)
|
|
err = sysfs_attach_link(sd, dentry);
|
|
else
|
|
err = sysfs_attach_attr(sd, dentry);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
struct inode_operations sysfs_dir_inode_operations = {
|
|
.lookup = sysfs_lookup,
|
|
.setattr = sysfs_setattr,
|
|
};
|
|
|
|
static void remove_dir(struct dentry * d)
|
|
{
|
|
struct dentry * parent = dget(d->d_parent);
|
|
struct sysfs_dirent * sd;
|
|
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
d_delete(d);
|
|
sd = d->d_fsdata;
|
|
list_del_init(&sd->s_sibling);
|
|
sysfs_put(sd);
|
|
if (d->d_inode)
|
|
simple_rmdir(parent->d_inode,d);
|
|
|
|
pr_debug(" o %s removing done (%d)\n",d->d_name.name,
|
|
atomic_read(&d->d_count));
|
|
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
dput(parent);
|
|
}
|
|
|
|
void sysfs_remove_subdir(struct dentry * d)
|
|
{
|
|
remove_dir(d);
|
|
}
|
|
|
|
|
|
/**
|
|
* sysfs_remove_dir - remove an object's directory.
|
|
* @kobj: object.
|
|
*
|
|
* The only thing special about this is that we remove any files in
|
|
* the directory before we remove the directory, and we've inlined
|
|
* what used to be sysfs_rmdir() below, instead of calling separately.
|
|
*/
|
|
|
|
void sysfs_remove_dir(struct kobject * kobj)
|
|
{
|
|
struct dentry * dentry = dget(kobj->dentry);
|
|
struct sysfs_dirent * parent_sd;
|
|
struct sysfs_dirent * sd, * tmp;
|
|
|
|
if (!dentry)
|
|
return;
|
|
|
|
pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
|
|
mutex_lock(&dentry->d_inode->i_mutex);
|
|
parent_sd = dentry->d_fsdata;
|
|
list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
|
|
if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
|
|
continue;
|
|
list_del_init(&sd->s_sibling);
|
|
sysfs_drop_dentry(sd, dentry);
|
|
sysfs_put(sd);
|
|
}
|
|
mutex_unlock(&dentry->d_inode->i_mutex);
|
|
|
|
remove_dir(dentry);
|
|
/**
|
|
* Drop reference from dget() on entrance.
|
|
*/
|
|
dput(dentry);
|
|
kobj->dentry = NULL;
|
|
}
|
|
|
|
int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
|
|
{
|
|
int error = 0;
|
|
struct dentry * new_dentry, * parent;
|
|
|
|
if (!strcmp(kobject_name(kobj), new_name))
|
|
return -EINVAL;
|
|
|
|
if (!kobj->parent)
|
|
return -EINVAL;
|
|
|
|
down_write(&sysfs_rename_sem);
|
|
parent = kobj->parent->dentry;
|
|
|
|
mutex_lock(&parent->d_inode->i_mutex);
|
|
|
|
new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
|
|
if (!IS_ERR(new_dentry)) {
|
|
if (!new_dentry->d_inode) {
|
|
error = kobject_set_name(kobj, "%s", new_name);
|
|
if (!error) {
|
|
d_add(new_dentry, NULL);
|
|
d_move(kobj->dentry, new_dentry);
|
|
}
|
|
else
|
|
d_drop(new_dentry);
|
|
} else
|
|
error = -EEXIST;
|
|
dput(new_dentry);
|
|
}
|
|
mutex_unlock(&parent->d_inode->i_mutex);
|
|
up_write(&sysfs_rename_sem);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int sysfs_dir_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct dentry * dentry = file->f_dentry;
|
|
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
|
|
|
|
mutex_lock(&dentry->d_inode->i_mutex);
|
|
file->private_data = sysfs_new_dirent(parent_sd, NULL);
|
|
mutex_unlock(&dentry->d_inode->i_mutex);
|
|
|
|
return file->private_data ? 0 : -ENOMEM;
|
|
|
|
}
|
|
|
|
static int sysfs_dir_close(struct inode *inode, struct file *file)
|
|
{
|
|
struct dentry * dentry = file->f_dentry;
|
|
struct sysfs_dirent * cursor = file->private_data;
|
|
|
|
mutex_lock(&dentry->d_inode->i_mutex);
|
|
list_del_init(&cursor->s_sibling);
|
|
mutex_unlock(&dentry->d_inode->i_mutex);
|
|
|
|
release_sysfs_dirent(cursor);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Relationship between s_mode and the DT_xxx types */
|
|
static inline unsigned char dt_type(struct sysfs_dirent *sd)
|
|
{
|
|
return (sd->s_mode >> 12) & 15;
|
|
}
|
|
|
|
static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
|
|
{
|
|
struct dentry *dentry = filp->f_dentry;
|
|
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
|
|
struct sysfs_dirent *cursor = filp->private_data;
|
|
struct list_head *p, *q = &cursor->s_sibling;
|
|
ino_t ino;
|
|
int i = filp->f_pos;
|
|
|
|
switch (i) {
|
|
case 0:
|
|
ino = dentry->d_inode->i_ino;
|
|
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
|
|
break;
|
|
filp->f_pos++;
|
|
i++;
|
|
/* fallthrough */
|
|
case 1:
|
|
ino = parent_ino(dentry);
|
|
if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
|
|
break;
|
|
filp->f_pos++;
|
|
i++;
|
|
/* fallthrough */
|
|
default:
|
|
if (filp->f_pos == 2)
|
|
list_move(q, &parent_sd->s_children);
|
|
|
|
for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
|
|
struct sysfs_dirent *next;
|
|
const char * name;
|
|
int len;
|
|
|
|
next = list_entry(p, struct sysfs_dirent,
|
|
s_sibling);
|
|
if (!next->s_element)
|
|
continue;
|
|
|
|
name = sysfs_get_name(next);
|
|
len = strlen(name);
|
|
if (next->s_dentry)
|
|
ino = next->s_dentry->d_inode->i_ino;
|
|
else
|
|
ino = iunique(sysfs_sb, 2);
|
|
|
|
if (filldir(dirent, name, len, filp->f_pos, ino,
|
|
dt_type(next)) < 0)
|
|
return 0;
|
|
|
|
list_move(q, p);
|
|
p = q;
|
|
filp->f_pos++;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
|
|
{
|
|
struct dentry * dentry = file->f_dentry;
|
|
|
|
mutex_lock(&dentry->d_inode->i_mutex);
|
|
switch (origin) {
|
|
case 1:
|
|
offset += file->f_pos;
|
|
case 0:
|
|
if (offset >= 0)
|
|
break;
|
|
default:
|
|
mutex_unlock(&file->f_dentry->d_inode->i_mutex);
|
|
return -EINVAL;
|
|
}
|
|
if (offset != file->f_pos) {
|
|
file->f_pos = offset;
|
|
if (file->f_pos >= 2) {
|
|
struct sysfs_dirent *sd = dentry->d_fsdata;
|
|
struct sysfs_dirent *cursor = file->private_data;
|
|
struct list_head *p;
|
|
loff_t n = file->f_pos - 2;
|
|
|
|
list_del(&cursor->s_sibling);
|
|
p = sd->s_children.next;
|
|
while (n && p != &sd->s_children) {
|
|
struct sysfs_dirent *next;
|
|
next = list_entry(p, struct sysfs_dirent,
|
|
s_sibling);
|
|
if (next->s_element)
|
|
n--;
|
|
p = p->next;
|
|
}
|
|
list_add_tail(&cursor->s_sibling, p);
|
|
}
|
|
}
|
|
mutex_unlock(&dentry->d_inode->i_mutex);
|
|
return offset;
|
|
}
|
|
|
|
const struct file_operations sysfs_dir_operations = {
|
|
.open = sysfs_dir_open,
|
|
.release = sysfs_dir_close,
|
|
.llseek = sysfs_dir_lseek,
|
|
.read = generic_read_dir,
|
|
.readdir = sysfs_readdir,
|
|
};
|