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 34struct posix_acl_entry { 35 short e_tag; 36 unsigned short e_perm; 37 unsigned int e_id; 38}; 39 40struct 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 */ 53static inline struct posix_acl * 54posix_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 */ 64static inline void 65posix_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 74extern struct posix_acl *posix_acl_alloc(int, gfp_t); 75extern struct posix_acl *posix_acl_clone(const struct posix_acl *, gfp_t); 76extern int posix_acl_valid(const struct posix_acl *); 77extern int posix_acl_permission(struct inode *, const struct posix_acl *, int); 78extern struct posix_acl *posix_acl_from_mode(mode_t, gfp_t); 79extern int posix_acl_equiv_mode(const struct posix_acl *, mode_t *); 80extern int posix_acl_create_masq(struct posix_acl *, mode_t *); 81extern int posix_acl_chmod_masq(struct posix_acl *, mode_t); 82 83extern struct posix_acl *get_posix_acl(struct inode *, int); 84extern int set_posix_acl(struct inode *, int, struct posix_acl *); 85 86#ifdef CONFIG_FS_POSIX_ACL 87static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) 88{ 89 struct posix_acl **p, *acl; 90 switch (type) { 91 case ACL_TYPE_ACCESS: 92 p = &inode->i_acl; 93 break; 94 case ACL_TYPE_DEFAULT: 95 p = &inode->i_default_acl; 96 break; 97 default: 98 return ERR_PTR(-EINVAL); 99 } 100 acl = ACCESS_ONCE(*p); 101 if (acl) { 102 spin_lock(&inode->i_lock); 103 acl = *p; 104 if (acl != ACL_NOT_CACHED) 105 acl = posix_acl_dup(acl); 106 spin_unlock(&inode->i_lock); 107 } 108 return acl; 109} 110 111static inline void set_cached_acl(struct inode *inode, 112 int type, 113 struct posix_acl *acl) 114{ 115 struct posix_acl *old = NULL; 116 spin_lock(&inode->i_lock); 117 switch (type) { 118 case ACL_TYPE_ACCESS: 119 old = inode->i_acl; 120 inode->i_acl = posix_acl_dup(acl); 121 break; 122 case ACL_TYPE_DEFAULT: 123 old = inode->i_default_acl; 124 inode->i_default_acl = posix_acl_dup(acl); 125 break; 126 } 127 spin_unlock(&inode->i_lock); 128 if (old != ACL_NOT_CACHED) 129 posix_acl_release(old); 130} 131 132static inline void forget_cached_acl(struct inode *inode, int type) 133{ 134 struct posix_acl *old = NULL; 135 spin_lock(&inode->i_lock); 136 switch (type) { 137 case ACL_TYPE_ACCESS: 138 old = inode->i_acl; 139 inode->i_acl = ACL_NOT_CACHED; 140 break; 141 case ACL_TYPE_DEFAULT: 142 old = inode->i_default_acl; 143 inode->i_default_acl = ACL_NOT_CACHED; 144 break; 145 } 146 spin_unlock(&inode->i_lock); 147 if (old != ACL_NOT_CACHED) 148 posix_acl_release(old); 149} 150 151static inline void forget_all_cached_acls(struct inode *inode) 152{ 153 struct posix_acl *old_access, *old_default; 154 spin_lock(&inode->i_lock); 155 old_access = inode->i_acl; 156 old_default = inode->i_default_acl; 157 inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; 158 spin_unlock(&inode->i_lock); 159 if (old_access != ACL_NOT_CACHED) 160 posix_acl_release(old_access); 161 if (old_default != ACL_NOT_CACHED) 162 posix_acl_release(old_default); 163} 164#endif 165 166static inline void cache_no_acl(struct inode *inode) 167{ 168#ifdef CONFIG_FS_POSIX_ACL 169 inode->i_acl = NULL; 170 inode->i_default_acl = NULL; 171#endif 172} 173 174#endif /* __LINUX_POSIX_ACL_H */ 175