[people/ms/linux.git] / include / linux / posix_acl.h

/*
  File: linux/posix_acl.h

  (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/


#ifndef __LINUX_POSIX_ACL_H
#define __LINUX_POSIX_ACL_H

#include <linux/bug.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>

#define ACL_UNDEFINED_ID	(-1)

/* a_type field in acl_user_posix_entry_t */
#define ACL_TYPE_ACCESS		(0x8000)
#define ACL_TYPE_DEFAULT	(0x4000)

/* e_tag entry in struct posix_acl_entry */
#define ACL_USER_OBJ		(0x01)
#define ACL_USER		(0x02)
#define ACL_GROUP_OBJ		(0x04)
#define ACL_GROUP		(0x08)
#define ACL_MASK		(0x10)
#define ACL_OTHER		(0x20)

/* permissions in the e_perm field */
#define ACL_READ		(0x04)
#define ACL_WRITE		(0x02)
#define ACL_EXECUTE		(0x01)
//#define ACL_ADD		(0x08)
//#define ACL_DELETE		(0x10)

struct posix_acl_entry {
	short			e_tag;
	unsigned short		e_perm;
	union {
		kuid_t		e_uid;
		kgid_t		e_gid;
#ifndef CONFIG_UIDGID_STRICT_TYPE_CHECKS
		unsigned int	e_id;
#endif
	};
};

struct posix_acl {
	union {
		atomic_t		a_refcount;
		struct rcu_head		a_rcu;
	};
	unsigned int		a_count;
	struct posix_acl_entry	a_entries[0];
};

#define FOREACH_ACL_ENTRY(pa, acl, pe) \
	for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)


/*
 * Duplicate an ACL handle.
 */
static inline struct posix_acl *
posix_acl_dup(struct posix_acl *acl)
{
	if (acl)
		atomic_inc(&acl->a_refcount);
	return acl;
}

/*
 * Free an ACL handle.
 */
static inline void
posix_acl_release(struct posix_acl *acl)
{
	if (acl && atomic_dec_and_test(&acl->a_refcount))
		kfree_rcu(acl, a_rcu);
}


/* posix_acl.c */

extern void posix_acl_init(struct posix_acl *, int);
extern struct posix_acl *posix_acl_alloc(int, gfp_t);
extern int posix_acl_valid(const struct posix_acl *);
extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);

extern struct posix_acl *get_posix_acl(struct inode *, int);
extern int set_posix_acl(struct inode *, int, struct posix_acl *);

#ifdef CONFIG_FS_POSIX_ACL
extern int posix_acl_chmod(struct inode *, umode_t);
extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
		struct posix_acl **);

static inline struct posix_acl **acl_by_type(struct inode *inode, int type)
{
	switch (type) {
	case ACL_TYPE_ACCESS:
		return &inode->i_acl;
	case ACL_TYPE_DEFAULT:
		return &inode->i_default_acl;
	default:
		BUG();
	}
}

static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
{
	struct posix_acl **p = acl_by_type(inode, type);
	struct posix_acl *acl = ACCESS_ONCE(*p);
	if (acl) {
		spin_lock(&inode->i_lock);
		acl = *p;
		if (acl != ACL_NOT_CACHED)
			acl = posix_acl_dup(acl);
		spin_unlock(&inode->i_lock);
	}
	return acl;
}

static inline struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
{
	return rcu_dereference(*acl_by_type(inode, type));
}

static inline void set_cached_acl(struct inode *inode,
				  int type,
				  struct posix_acl *acl)
{
	struct posix_acl **p = acl_by_type(inode, type);
	struct posix_acl *old;
	spin_lock(&inode->i_lock);
	old = *p;
	rcu_assign_pointer(*p, posix_acl_dup(acl));
	spin_unlock(&inode->i_lock);
	if (old != ACL_NOT_CACHED)
		posix_acl_release(old);
}

static inline void forget_cached_acl(struct inode *inode, int type)
{
	struct posix_acl **p = acl_by_type(inode, type);
	struct posix_acl *old;
	spin_lock(&inode->i_lock);
	old = *p;
	*p = ACL_NOT_CACHED;
	spin_unlock(&inode->i_lock);
	if (old != ACL_NOT_CACHED)
		posix_acl_release(old);
}

static inline void forget_all_cached_acls(struct inode *inode)
{
	struct posix_acl *old_access, *old_default;
	spin_lock(&inode->i_lock);
	old_access = inode->i_acl;
	old_default = inode->i_default_acl;
	inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
	spin_unlock(&inode->i_lock);
	if (old_access != ACL_NOT_CACHED)
		posix_acl_release(old_access);
	if (old_default != ACL_NOT_CACHED)
		posix_acl_release(old_default);
}

static inline void cache_no_acl(struct inode *inode)
{
	inode->i_acl = NULL;
	inode->i_default_acl = NULL;
}
#else
static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
{
	return 0;
}

static inline void cache_no_acl(struct inode *inode)
{
}

static inline int posix_acl_create(struct inode *inode, umode_t *mode,
		struct posix_acl **default_acl, struct posix_acl **acl)
{
	*default_acl = *acl = NULL;
	return 0;
}

static inline void forget_all_cached_acls(struct inode *inode)
{
}
#endif /* CONFIG_FS_POSIX_ACL */

struct posix_acl *get_acl(struct inode *inode, int type);

#endif  /* __LINUX_POSIX_ACL_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	File: linux/posix_acl.h
	3
	4	(C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
	5	*/
	6
	7
	8	#ifndef __LINUX_POSIX_ACL_H
	9	#define __LINUX_POSIX_ACL_H
	10
187f1882	11	#include <linux/bug.h>
1da177e4	12	#include <linux/slab.h>
3567866b	13	#include <linux/rcupdate.h>
1da177e4 LT	14
	15	#define ACL_UNDEFINED_ID (-1)
	16
	17	/* a_type field in acl_user_posix_entry_t */
	18	#define ACL_TYPE_ACCESS (0x8000)
	19	#define ACL_TYPE_DEFAULT (0x4000)
	20
	21	/* e_tag entry in struct posix_acl_entry */
	22	#define ACL_USER_OBJ (0x01)
	23	#define ACL_USER (0x02)
	24	#define ACL_GROUP_OBJ (0x04)
	25	#define ACL_GROUP (0x08)
	26	#define ACL_MASK (0x10)
	27	#define ACL_OTHER (0x20)
	28
	29	/* permissions in the e_perm field */
	30	#define ACL_READ (0x04)
	31	#define ACL_WRITE (0x02)
	32	#define ACL_EXECUTE (0x01)
	33	//#define ACL_ADD (0x08)
	34	//#define ACL_DELETE (0x10)
	35
	36	struct posix_acl_entry {
	37	short e_tag;
	38	unsigned short e_perm;
2f6f0654 EB	39	union {
	40	kuid_t e_uid;
	41	kgid_t e_gid;
	42	#ifndef CONFIG_UIDGID_STRICT_TYPE_CHECKS
	43	unsigned int e_id;
	44	#endif
	45	};
1da177e4 LT	46	};
	47
	48	struct posix_acl {
3567866b AV	49	union {
	50	atomic_t a_refcount;
	51	struct rcu_head a_rcu;
	52	};
1da177e4 LT	53	unsigned int a_count;
	54	struct posix_acl_entry a_entries[0];
	55	};
	56
	57	#define FOREACH_ACL_ENTRY(pa, acl, pe) \
	58	for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
	59
	60
	61	/*
	62	* Duplicate an ACL handle.
	63	*/
	64	static inline struct posix_acl *
	65	posix_acl_dup(struct posix_acl *acl)
	66	{
	67	if (acl)
	68	atomic_inc(&acl->a_refcount);
	69	return acl;
	70	}
	71
	72	/*
	73	* Free an ACL handle.
	74	*/
	75	static inline void
	76	posix_acl_release(struct posix_acl *acl)
	77	{
	78	if (acl && atomic_dec_and_test(&acl->a_refcount))
3567866b	79	kfree_rcu(acl, a_rcu);
1da177e4 LT	80	}
	81
	82
	83	/* posix_acl.c */
	84
f61f6da0	85	extern void posix_acl_init(struct posix_acl *, int);
dd0fc66f	86	extern struct posix_acl *posix_acl_alloc(int, gfp_t);
1da177e4 LT	87	extern int posix_acl_valid(const struct posix_acl *);
1da177e4 LT	88	extern int posix_acl_permission(struct inode , const struct posix_acl , int);
3a5fba19	89	extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
d6952123	90	extern int posix_acl_equiv_mode(const struct posix_acl , umode_t );
37bc1539	91	extern int __posix_acl_create(struct posix_acl *, gfp_t, umode_t );
5bf3258f	92	extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
1da177e4 LT	93
	94	extern struct posix_acl get_posix_acl(struct inode , int);
	95	extern int set_posix_acl(struct inode , int, struct posix_acl );
	96
641cf4a6	97	#ifdef CONFIG_FS_POSIX_ACL
37bc1539 CH	98	extern int posix_acl_chmod(struct inode *, umode_t);
	99	extern int posix_acl_create(struct inode , umode_t , struct posix_acl **,
	100	struct posix_acl **);
5bf3258f	101
951c0d66	102	static inline struct posix_acl *acl_by_type(struct inode inode, int type)
073aaa1b	103	{
073aaa1b AV	104	switch (type) {
073aaa1b AV	105	case ACL_TYPE_ACCESS:
951c0d66	106	return &inode->i_acl;
073aaa1b	107	case ACL_TYPE_DEFAULT:
951c0d66	108	return &inode->i_default_acl;
073aaa1b	109	default:
951c0d66	110	BUG();
073aaa1b	111	}
951c0d66 AV	112	}
	113
	114	static inline struct posix_acl get_cached_acl(struct inode inode, int type)
	115	{
	116	struct posix_acl **p = acl_by_type(inode, type);
	117	struct posix_acl acl = ACCESS_ONCE(p);
073aaa1b AV	118	if (acl) {
	119	spin_lock(&inode->i_lock);
	120	acl = *p;
	121	if (acl != ACL_NOT_CACHED)
	122	acl = posix_acl_dup(acl);
	123	spin_unlock(&inode->i_lock);
	124	}
	125	return acl;
	126	}
	127
3567866b	128	static inline struct posix_acl get_cached_acl_rcu(struct inode inode, int type)
1e1743eb	129	{
3567866b	130	return rcu_dereference(*acl_by_type(inode, type));
1e1743eb NP	131	}
1e1743eb NP	132
073aaa1b AV	133	static inline void set_cached_acl(struct inode *inode,
	134	int type,
	135	struct posix_acl *acl)
	136	{
951c0d66 AV	137	struct posix_acl **p = acl_by_type(inode, type);
951c0d66 AV	138	struct posix_acl *old;
073aaa1b	139	spin_lock(&inode->i_lock);
951c0d66	140	old = *p;
3567866b	141	rcu_assign_pointer(*p, posix_acl_dup(acl));
073aaa1b AV	142	spin_unlock(&inode->i_lock);
	143	if (old != ACL_NOT_CACHED)
	144	posix_acl_release(old);
	145	}
	146
	147	static inline void forget_cached_acl(struct inode *inode, int type)
	148	{
951c0d66 AV	149	struct posix_acl **p = acl_by_type(inode, type);
951c0d66 AV	150	struct posix_acl *old;
073aaa1b	151	spin_lock(&inode->i_lock);
951c0d66 AV	152	old = *p;
951c0d66 AV	153	*p = ACL_NOT_CACHED;
073aaa1b AV	154	spin_unlock(&inode->i_lock);
	155	if (old != ACL_NOT_CACHED)
	156	posix_acl_release(old);
	157	}
796bd952 SW	158
	159	static inline void forget_all_cached_acls(struct inode *inode)
	160	{
	161	struct posix_acl old_access, old_default;
	162	spin_lock(&inode->i_lock);
	163	old_access = inode->i_acl;
	164	old_default = inode->i_default_acl;
	165	inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
	166	spin_unlock(&inode->i_lock);
	167	if (old_access != ACL_NOT_CACHED)
	168	posix_acl_release(old_access);
	169	if (old_default != ACL_NOT_CACHED)
	170	posix_acl_release(old_default);
	171	}
72c04902 AV	172
	173	static inline void cache_no_acl(struct inode *inode)
	174	{
72c04902 AV	175	inode->i_acl = NULL;
72c04902 AV	176	inode->i_default_acl = NULL;
72c04902	177	}
5bf3258f	178	#else
37bc1539	179	static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
5bf3258f CH	180	{
	181	return 0;
	182	}
	183
	184	static inline void cache_no_acl(struct inode *inode)
	185	{
	186	}
37bc1539 CH	187
	188	static inline int posix_acl_create(struct inode inode, umode_t mode,
	189	struct posix_acl default_acl, struct posix_acl acl)
	190	{
	191	default_acl = acl = NULL;
	192	return 0;
	193	}
013cdf10 CH	194
	195	static inline void forget_all_cached_acls(struct inode *inode)
	196	{
	197	}
5bf3258f	198	#endif /* CONFIG_FS_POSIX_ACL */
72c04902	199
2982baa2 CH	200	struct posix_acl get_acl(struct inode inode, int type);
2982baa2 CH	201
1da177e4	202	#endif /* __LINUX_POSIX_ACL_H */