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kolibrios/drivers/include/linux/kernfs.h
Sergey Semyonov (Serge) 66fbaa74b0 ddk: v4.6.7
git-svn-id: svn://kolibrios.org@7143 a494cfbc-eb01-0410-851d-a64ba20cac60
2018-02-02 14:53:42 +00:00

141 lines
3.5 KiB
C

/*
* 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/idr.h>
#include <linux/lockdep.h>
#include <linux/rbtree.h>
#include <linux/atomic.h>
#include <linux/wait.h>
struct file;
struct dentry;
struct iattr;
struct seq_file;
struct vm_area_struct;
struct super_block;
struct file_system_type;
struct kernfs_open_node;
struct kernfs_iattrs;
enum kernfs_node_type {
KERNFS_DIR = 0x0001,
KERNFS_FILE = 0x0002,
KERNFS_LINK = 0x0004,
};
#define KERNFS_TYPE_MASK 0x000f
#define KERNFS_FLAG_MASK ~KERNFS_TYPE_MASK
enum kernfs_node_flag {
KERNFS_ACTIVATED = 0x0010,
KERNFS_NS = 0x0020,
KERNFS_HAS_SEQ_SHOW = 0x0040,
KERNFS_HAS_MMAP = 0x0080,
KERNFS_LOCKDEP = 0x0100,
KERNFS_SUICIDAL = 0x0400,
KERNFS_SUICIDED = 0x0800,
KERNFS_EMPTY_DIR = 0x1000,
};
/* @flags for kernfs_create_root() */
enum kernfs_root_flag {
/*
* kernfs_nodes are created in the deactivated state and invisible.
* They require explicit kernfs_activate() to become visible. This
* can be used to make related nodes become visible atomically
* after all nodes are created successfully.
*/
KERNFS_ROOT_CREATE_DEACTIVATED = 0x0001,
/*
* For regular flies, if the opener has CAP_DAC_OVERRIDE, open(2)
* succeeds regardless of the RW permissions. sysfs had an extra
* layer of enforcement where open(2) fails with -EACCES regardless
* of CAP_DAC_OVERRIDE if the permission doesn't have the
* respective read or write access at all (none of S_IRUGO or
* S_IWUGO) or the respective operation isn't implemented. The
* following flag enables that behavior.
*/
KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK = 0x0002,
};
/* type-specific structures for kernfs_node union members */
struct kernfs_elem_dir {
unsigned long subdirs;
/* children rbtree starts here and goes through kn->rb */
struct rb_root children;
/*
* The kernfs hierarchy this directory belongs to. This fits
* better directly in kernfs_node but is here to save space.
*/
struct kernfs_root *root;
};
struct kernfs_elem_symlink {
struct kernfs_node *target_kn;
};
struct kernfs_elem_attr {
const struct kernfs_ops *ops;
struct kernfs_open_node *open;
loff_t size;
struct kernfs_node *notify_next; /* for kernfs_notify() */
};
/*
* kernfs_node - the building block of kernfs hierarchy. Each and every
* kernfs node is represented by single kernfs_node. Most fields are
* private to kernfs and shouldn't be accessed directly by kernfs users.
*
* As long as s_count reference is held, the kernfs_node itself is
* accessible. Dereferencing elem or any other outer entity requires
* active reference.
*/
struct kernfs_node {
atomic_t count;
atomic_t active;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
/*
* Use kernfs_get_parent() and kernfs_name/path() instead of
* accessing the following two fields directly. If the node is
* never moved to a different parent, it is safe to access the
* parent directly.
*/
struct kernfs_node *parent;
const char *name;
struct rb_node rb;
const void *ns; /* namespace tag */
unsigned int hash; /* ns + name hash */
union {
struct kernfs_elem_dir dir;
struct kernfs_elem_symlink symlink;
struct kernfs_elem_attr attr;
};
void *priv;
unsigned short flags;
umode_t mode;
unsigned int ino;
struct kernfs_iattrs *iattr;
};
#endif /* __LINUX_KERNFS_H */