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