blob: f75548b8ed7a3f97aa445ba4b756a58d414dd835 [file] [log] [blame]
/*
* kernfs.h - pseudo filesystem decoupled from vfs locking
*
* This file is released under the GPLv2.
*/
#ifndef __LINUX_KERNFS_H
#define __LINUX_KERNFS_H
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/lockdep.h>
struct file;
struct iattr;
struct seq_file;
struct vm_area_struct;
struct sysfs_dirent;
struct kernfs_root {
/* published fields */
struct sysfs_dirent *sd;
};
struct sysfs_open_file {
/* published fields */
struct sysfs_dirent *sd;
struct file *file;
/* private fields, do not use outside kernfs proper */
struct mutex mutex;
int event;
struct list_head list;
bool mmapped;
const struct vm_operations_struct *vm_ops;
};
struct kernfs_ops {
/*
* Read is handled by either seq_file or raw_read().
*
* If seq_show() is present, seq_file path is active. Other seq
* operations are optional and if not implemented, the behavior is
* equivalent to single_open(). @sf->private points to the
* associated sysfs_open_file.
*
* read() is bounced through kernel buffer and a read larger than
* PAGE_SIZE results in partial operation of PAGE_SIZE.
*/
int (*seq_show)(struct seq_file *sf, void *v);
void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
void (*seq_stop)(struct seq_file *sf, void *v);
ssize_t (*read)(struct sysfs_open_file *of, char *buf, size_t bytes,
loff_t off);
/*
* write() is bounced through kernel buffer and a write larger than
* PAGE_SIZE results in partial operation of PAGE_SIZE.
*/
ssize_t (*write)(struct sysfs_open_file *of, char *buf, size_t bytes,
loff_t off);
int (*mmap)(struct sysfs_open_file *of, struct vm_area_struct *vma);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lock_class_key lockdep_key;
#endif
};
#ifdef CONFIG_SYSFS
struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
const char *name, const void *ns);
void kernfs_get(struct sysfs_dirent *sd);
void kernfs_put(struct sysfs_dirent *sd);
struct kernfs_root *kernfs_create_root(void *priv);
void kernfs_destroy_root(struct kernfs_root *root);
struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
const char *name, void *priv,
const void *ns);
struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent,
const char *name,
umode_t mode, loff_t size,
const struct kernfs_ops *ops,
void *priv, const void *ns,
struct lock_class_key *key);
struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
const char *name,
struct sysfs_dirent *target);
void kernfs_remove(struct sysfs_dirent *sd);
int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name,
const void *ns);
int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
const char *new_name, const void *new_ns);
void kernfs_enable_ns(struct sysfs_dirent *sd);
int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
void kernfs_notify(struct sysfs_dirent *sd);
#else /* CONFIG_SYSFS */
static inline struct sysfs_dirent *
kernfs_find_and_get_ns(struct sysfs_dirent *parent, const char *name,
const void *ns)
{ return NULL; }
static inline void kernfs_get(struct sysfs_dirent *sd) { }
static inline void kernfs_put(struct sysfs_dirent *sd) { }
static inline struct kernfs_root *kernfs_create_root(void *priv)
{ return ERR_PTR(-ENOSYS); }
static inline void kernfs_destroy_root(struct kernfs_root *root) { }
static inline struct sysfs_dirent *
kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv,
const void *ns)
{ return ERR_PTR(-ENOSYS); }
static inline struct sysfs_dirent *
kernfs_create_file_ns_key(struct sysfs_dirent *parent, const char *name,
umode_t mode, loff_t size,
const struct kernfs_ops *ops, void *priv,
const void *ns, struct lock_class_key *key)
{ return ERR_PTR(-ENOSYS); }
static inline struct sysfs_dirent *
kernfs_create_link(struct sysfs_dirent *parent, const char *name,
struct sysfs_dirent *target)
{ return ERR_PTR(-ENOSYS); }
static inline void kernfs_remove(struct sysfs_dirent *sd) { }
static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,
const char *name, const void *ns)
{ return -ENOSYS; }
static inline int kernfs_rename_ns(struct sysfs_dirent *sd,
struct sysfs_dirent *new_parent,
const char *new_name, const void *new_ns)
{ return -ENOSYS; }
static inline void kernfs_enable_ns(struct sysfs_dirent *sd) { }
static inline int kernfs_setattr(struct sysfs_dirent *sd,
const struct iattr *iattr)
{ return -ENOSYS; }
static inline void kernfs_notify(struct sysfs_dirent *sd) { }
#endif /* CONFIG_SYSFS */
static inline struct sysfs_dirent *
kernfs_find_and_get(struct sysfs_dirent *sd, const char *name)
{
return kernfs_find_and_get_ns(sd, name, NULL);
}
static inline struct sysfs_dirent *
kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv)
{
return kernfs_create_dir_ns(parent, name, priv, NULL);
}
static inline struct sysfs_dirent *
kernfs_create_file_ns(struct sysfs_dirent *parent, const char *name,
umode_t mode, loff_t size, const struct kernfs_ops *ops,
void *priv, const void *ns)
{
struct lock_class_key *key = NULL;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
key = (struct lock_class_key *)&ops->lockdep_key;
#endif
return kernfs_create_file_ns_key(parent, name, mode, size, ops, priv,
ns, key);
}
static inline struct sysfs_dirent *
kernfs_create_file(struct sysfs_dirent *parent, const char *name, umode_t mode,
loff_t size, const struct kernfs_ops *ops, void *priv)
{
return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
}
static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
const char *name)
{
return kernfs_remove_by_name_ns(parent, name, NULL);
}
#endif /* __LINUX_KERNFS_H */