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linux-next/fs/sysfs/sysfs.h
Rafael J. Wysocki 0bb8f3d6ae sysfs: Functions for adding/removing symlinks to/from attribute groups
The most convenient way to expose ACPI power resources lists of a
device is to put symbolic links to sysfs directories representing
those resources into special attribute groups in the device's sysfs
directory.  For this purpose, it is necessary to be able to add
symbolic links to attribute groups.

For this reason, add sysfs helper functions for adding/removing
symbolic links to/from attribute groups, sysfs_add_link_to_group()
and sysfs_remove_link_from_group(), respectively.

This change set includes a build fix from David Rientjes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25 21:51:13 +01:00

245 lines
6.6 KiB
C

/*
* fs/sysfs/sysfs.h - sysfs internal header file
*
* Copyright (c) 2001-3 Patrick Mochel
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*
* This file is released under the GPLv2.
*/
#include <linux/lockdep.h>
#include <linux/kobject_ns.h>
#include <linux/fs.h>
#include <linux/rbtree.h>
struct sysfs_open_dirent;
/* type-specific structures for sysfs_dirent->s_* union members */
struct sysfs_elem_dir {
struct kobject *kobj;
unsigned long subdirs;
/* children rbtree starts here and goes through sd->s_rb */
struct rb_root children;
};
struct sysfs_elem_symlink {
struct sysfs_dirent *target_sd;
};
struct sysfs_elem_attr {
struct attribute *attr;
struct sysfs_open_dirent *open;
};
struct sysfs_elem_bin_attr {
struct bin_attribute *bin_attr;
struct hlist_head buffers;
};
struct sysfs_inode_attrs {
struct iattr ia_iattr;
void *ia_secdata;
u32 ia_secdata_len;
};
/*
* sysfs_dirent - the building block of sysfs hierarchy. Each and
* every sysfs node is represented by single sysfs_dirent.
*
* As long as s_count reference is held, the sysfs_dirent itself is
* accessible. Dereferencing s_elem or any other outer entity
* requires s_active reference.
*/
struct sysfs_dirent {
atomic_t s_count;
atomic_t s_active;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
struct sysfs_dirent *s_parent;
const char *s_name;
struct rb_node s_rb;
union {
struct completion *completion;
struct sysfs_dirent *removed_list;
} u;
const void *s_ns; /* namespace tag */
unsigned int s_hash; /* ns + name hash */
union {
struct sysfs_elem_dir s_dir;
struct sysfs_elem_symlink s_symlink;
struct sysfs_elem_attr s_attr;
struct sysfs_elem_bin_attr s_bin_attr;
};
unsigned short s_flags;
umode_t s_mode;
unsigned int s_ino;
struct sysfs_inode_attrs *s_iattr;
};
#define SD_DEACTIVATED_BIAS INT_MIN
#define SYSFS_TYPE_MASK 0x00ff
#define SYSFS_DIR 0x0001
#define SYSFS_KOBJ_ATTR 0x0002
#define SYSFS_KOBJ_BIN_ATTR 0x0004
#define SYSFS_KOBJ_LINK 0x0008
#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
/* identify any namespace tag on sysfs_dirents */
#define SYSFS_NS_TYPE_MASK 0xf00
#define SYSFS_NS_TYPE_SHIFT 8
#define SYSFS_FLAG_MASK ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
#define SYSFS_FLAG_REMOVED 0x02000
static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
{
return sd->s_flags & SYSFS_TYPE_MASK;
}
/*
* Return any namespace tags on this dirent.
* enum kobj_ns_type is defined in linux/kobject.h
*/
static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
{
return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define sysfs_dirent_init_lockdep(sd) \
do { \
struct attribute *attr = sd->s_attr.attr; \
struct lock_class_key *key = attr->key; \
if (!key) \
key = &attr->skey; \
\
lockdep_init_map(&sd->dep_map, "s_active", key, 0); \
} while(0)
#else
#define sysfs_dirent_init_lockdep(sd) do {} while(0)
#endif
/*
* Context structure to be used while adding/removing nodes.
*/
struct sysfs_addrm_cxt {
struct sysfs_dirent *parent_sd;
struct sysfs_dirent *removed;
};
/*
* mount.c
*/
/*
* Each sb is associated with a set of namespace tags (i.e.
* the network namespace of the task which mounted this sysfs
* instance).
*/
struct sysfs_super_info {
void *ns[KOBJ_NS_TYPES];
};
#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
extern struct sysfs_dirent sysfs_root;
extern struct kmem_cache *sysfs_dir_cachep;
/*
* dir.c
*/
extern struct mutex sysfs_mutex;
extern spinlock_t sysfs_assoc_lock;
extern const struct dentry_operations sysfs_dentry_ops;
extern const struct file_operations sysfs_dir_operations;
extern const struct inode_operations sysfs_dir_inode_operations;
struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
void sysfs_put_active(struct sysfs_dirent *sd);
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
struct sysfs_dirent *parent_sd);
int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
const void *ns,
const unsigned char *name);
struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
const void *ns,
const unsigned char *name);
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
void release_sysfs_dirent(struct sysfs_dirent *sd);
int sysfs_create_subdir(struct kobject *kobj, const char *name,
struct sysfs_dirent **p_sd);
void sysfs_remove_subdir(struct sysfs_dirent *sd);
int sysfs_rename(struct sysfs_dirent *sd,
struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);
static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
{
if (sd) {
WARN_ON(!atomic_read(&sd->s_count));
atomic_inc(&sd->s_count);
}
return sd;
}
#define sysfs_get(sd) __sysfs_get(sd)
static inline void __sysfs_put(struct sysfs_dirent *sd)
{
if (sd && atomic_dec_and_test(&sd->s_count))
release_sysfs_dirent(sd);
}
#define sysfs_put(sd) __sysfs_put(sd)
/*
* inode.c
*/
struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
void sysfs_evict_inode(struct inode *inode);
int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
int sysfs_permission(struct inode *inode, int mask);
int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags);
int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
int sysfs_inode_init(void);
/*
* file.c
*/
extern const struct file_operations sysfs_file_operations;
int sysfs_add_file(struct sysfs_dirent *dir_sd,
const struct attribute *attr, int type);
int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
const struct attribute *attr, int type, umode_t amode);
/*
* bin.c
*/
extern const struct file_operations bin_fops;
void unmap_bin_file(struct sysfs_dirent *attr_sd);
/*
* symlink.c
*/
extern const struct inode_operations sysfs_symlink_inode_operations;
int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
const char *name);