[mirror_ubuntu-zesty-kernel.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/slab.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;
	unsigned int		e_id;
};

struct posix_acl {
	atomic_t		a_refcount;
	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(acl);
}


/* posix_acl.c */

extern void posix_acl_init(struct posix_acl *, int);
extern struct posix_acl *posix_acl_alloc(int, gfp_t);
extern struct posix_acl *posix_acl_clone(const struct posix_acl *, 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(mode_t, gfp_t);
extern int posix_acl_equiv_mode(const struct posix_acl *, mode_t *);
extern int posix_acl_create_masq(struct posix_acl *, mode_t *);
extern int posix_acl_chmod_masq(struct posix_acl *, mode_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
static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
{
	struct posix_acl **p, *acl;
	switch (type) {
	case ACL_TYPE_ACCESS:
		p = &inode->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		p = &inode->i_default_acl;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}
	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 int negative_cached_acl(struct inode *inode, int type)
{
	struct posix_acl **p, *acl;
	switch (type) {
	case ACL_TYPE_ACCESS:
		p = &inode->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		p = &inode->i_default_acl;
		break;
	default:
		BUG();
	}
	acl = ACCESS_ONCE(*p);
	if (acl)
		return 0;
	return 1;
}

static inline void set_cached_acl(struct inode *inode,
				  int type,
				  struct posix_acl *acl)
{
	struct posix_acl *old = NULL;
	spin_lock(&inode->i_lock);
	switch (type) {
	case ACL_TYPE_ACCESS:
		old = inode->i_acl;
		inode->i_acl = posix_acl_dup(acl);
		break;
	case ACL_TYPE_DEFAULT:
		old = inode->i_default_acl;
		inode->i_default_acl = posix_acl_dup(acl);
		break;
	}
	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 *old = NULL;
	spin_lock(&inode->i_lock);
	switch (type) {
	case ACL_TYPE_ACCESS:
		old = inode->i_acl;
		inode->i_acl = ACL_NOT_CACHED;
		break;
	case ACL_TYPE_DEFAULT:
		old = inode->i_default_acl;
		inode->i_default_acl = ACL_NOT_CACHED;
		break;
	}
	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);
}
#endif

static inline void cache_no_acl(struct inode *inode)
{
#ifdef CONFIG_FS_POSIX_ACL
	inode->i_acl = NULL;
	inode->i_default_acl = NULL;
#endif
}

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