acl.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3   File: fs/ext4/acl.h
   4
   5   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   6 */
   7
   8 #include <linux/posix_acl_xattr.h>
   9
  10 #define EXT4_ACL_VERSION        0x0001
  11
  12 typedef struct {
  13         __le16          e_tag;
  14         __le16          e_perm;
  15         __le32          e_id;
  16 } ext4_acl_entry;
  17
  18 typedef struct {
  19         __le16          e_tag;
  20         __le16          e_perm;
  21 } ext4_acl_entry_short;
  22
  23 typedef struct {
  24         __le32          a_version;
  25 } ext4_acl_header;
  26
  27 static inline size_t ext4_acl_size(int count)
  28 {
  29         if (count <= 4) {
  30                 return sizeof(ext4_acl_header) +
  31                        count * sizeof(ext4_acl_entry_short);
  32         } else {
  33                 return sizeof(ext4_acl_header) +
  34                        4 * sizeof(ext4_acl_entry_short) +
  35                        (count - 4) * sizeof(ext4_acl_entry);
  36         }
  37 }
  38
  39 static inline int ext4_acl_count(size_t size)
  40 {
  41         ssize_t s;
  42         size -= sizeof(ext4_acl_header);
  43         s = size - 4 * sizeof(ext4_acl_entry_short);
  44         if (s < 0) {
  45                 if (size % sizeof(ext4_acl_entry_short))
  46                         return -1;
  47                 return size / sizeof(ext4_acl_entry_short);
  48         } else {
  49                 if (s % sizeof(ext4_acl_entry))
  50                         return -1;
  51                 return s / sizeof(ext4_acl_entry) + 4;
  52         }
  53 }
  54
  55 #ifdef CONFIG_EXT4_FS_POSIX_ACL
  56
  57 /* acl.c */
  58 struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu);
  59 int ext4_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
  60                  struct posix_acl *acl, int type);
  61 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
  62
  63 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
  64 #include <linux/sched.h>
  65 #define ext4_get_acl NULL
  66 #define ext4_set_acl NULL
  67
  68 static inline int
  69 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
  70 {
  71         /* usually, the umask is applied by posix_acl_create(), but if
  72            ext4 ACL support is disabled at compile time, we need to do
  73            it here, because posix_acl_create() will never be called */
  74         inode->i_mode &= ~current_umask();
  75
  76         return 0;
  77 }
  78 #endif  /* CONFIG_EXT4_FS_POSIX_ACL */
  79