include/linux/posix_acl.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3   File: linux/posix_acl.h
   4
   5   (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   6 */
   7
   8
   9 #ifndef __LINUX_POSIX_ACL_H
  10 #define __LINUX_POSIX_ACL_H
  11
  12 #include <linux/bug.h>
  13 #include <linux/slab.h>
  14 #include <linux/rcupdate.h>
  15 #include <uapi/linux/posix_acl.h>
  16
  17 struct posix_acl_entry {
  18         short                   e_tag;
  19         unsigned short          e_perm;
  20         union {
  21                 kuid_t          e_uid;
  22                 kgid_t          e_gid;
  23         };
  24 };
  25
  26 struct posix_acl {
  27         atomic_t                a_refcount;
  28         struct rcu_head         a_rcu;
  29         unsigned int            a_count;
  30         struct posix_acl_entry  a_entries[0];
  31 };
  32
  33 #define FOREACH_ACL_ENTRY(pa, acl, pe) \
  34         for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
  35
  36
  37 /*
  38  * Duplicate an ACL handle.
  39  */
  40 static inline struct posix_acl *
  41 posix_acl_dup(struct posix_acl *acl)
  42 {
  43         if (acl)
  44                 atomic_inc(&acl->a_refcount);
  45         return acl;
  46 }
  47
  48 /*
  49  * Free an ACL handle.
  50  */
  51 static inline void
  52 posix_acl_release(struct posix_acl *acl)
  53 {
  54         if (acl && atomic_dec_and_test(&acl->a_refcount))
  55                 kfree_rcu(acl, a_rcu);
  56 }
  57
  58
  59 /* posix_acl.c */
  60
  61 extern void posix_acl_init(struct posix_acl *, int);
  62 extern struct posix_acl *posix_acl_alloc(int, gfp_t);
  63 extern int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
  64 extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
  65 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
  66 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
  67 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
  68 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
  69
  70 extern struct posix_acl *get_posix_acl(struct inode *, int);
  71 extern int set_posix_acl(struct inode *, int, struct posix_acl *);
  72
  73 #ifdef CONFIG_FS_POSIX_ACL
  74 extern int posix_acl_chmod(struct inode *, umode_t);
  75 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
  76                 struct posix_acl **);
  77 extern int posix_acl_update_mode(struct inode *, umode_t *, struct posix_acl **);
  78
  79 extern int simple_set_acl(struct inode *, struct posix_acl *, int);
  80 extern int simple_acl_create(struct inode *, struct inode *);
  81
  82 struct posix_acl *get_cached_acl(struct inode *inode, int type);
  83 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
  84 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
  85 void forget_cached_acl(struct inode *inode, int type);
  86 void forget_all_cached_acls(struct inode *inode);
  87
  88 static inline void cache_no_acl(struct inode *inode)
  89 {
  90         inode->i_acl = NULL;
  91         inode->i_default_acl = NULL;
  92 }
  93 #else
  94 static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
  95 {
  96         return 0;
  97 }
  98
  99 #define simple_set_acl          NULL
 100
 101 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
 102 {
 103         return 0;
 104 }
 105 static inline void cache_no_acl(struct inode *inode)
 106 {
 107 }
 108
 109 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
 110                 struct posix_acl **default_acl, struct posix_acl **acl)
 111 {
 112         *default_acl = *acl = NULL;
 113         return 0;
 114 }
 115
 116 static inline void forget_all_cached_acls(struct inode *inode)
 117 {
 118 }
 119 #endif /* CONFIG_FS_POSIX_ACL */
 120
 121 struct posix_acl *get_acl(struct inode *inode, int type);
 122
 123 #endif  /* __LINUX_POSIX_ACL_H */