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   1 /*
   2   File: fs/ext4/acl.h
   3
   4   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   5 */
   6
   7 #include <linux/posix_acl_xattr.h>
   8
   9 #define EXT4_ACL_VERSION        0x0001
  10
  11 typedef struct {
  12         __le16          e_tag;
  13         __le16          e_perm;
  14         __le32          e_id;
  15 } ext4_acl_entry;
  16
  17 typedef struct {
  18         __le16          e_tag;
  19         __le16          e_perm;
  20 } ext4_acl_entry_short;
  21
  22 typedef struct {
  23         __le32          a_version;
  24 } ext4_acl_header;
  25
  26 static inline size_t ext4_acl_size(int count)
  27 {
  28         if (count <= 4) {
  29                 return sizeof(ext4_acl_header) +
  30                        count * sizeof(ext4_acl_entry_short);
  31         } else {
  32                 return sizeof(ext4_acl_header) +
  33                        4 * sizeof(ext4_acl_entry_short) +
  34                        (count - 4) * sizeof(ext4_acl_entry);
  35         }
  36 }
  37
  38 static inline int ext4_acl_count(size_t size)
  39 {
  40         ssize_t s;
  41         size -= sizeof(ext4_acl_header);
  42         s = size - 4 * sizeof(ext4_acl_entry_short);
  43         if (s < 0) {
  44                 if (size % sizeof(ext4_acl_entry_short))
  45                         return -1;
  46                 return size / sizeof(ext4_acl_entry_short);
  47         } else {
  48                 if (s % sizeof(ext4_acl_entry))
  49                         return -1;
  50                 return s / sizeof(ext4_acl_entry) + 4;
  51         }
  52 }
  53
  54 #ifdef CONFIG_EXT4_FS_POSIX_ACL
  55
  56 /* Value for inode->u.ext4_i.i_acl and inode->u.ext4_i.i_default_acl
  57    if the ACL has not been cached */
  58 #define EXT4_ACL_NOT_CACHED ((void *)-1)
  59
  60 /* acl.c */
  61 extern int ext4_permission(struct inode *, int);
  62 extern int ext4_acl_chmod(struct inode *);
  63 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
  64
  65 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
  66 #include <linux/sched.h>
  67 #define ext4_permission NULL
  68
  69 static inline int
  70 ext4_acl_chmod(struct inode *inode)
  71 {
  72         return 0;
  73 }
  74
  75 static inline int
  76 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
  77 {
  78         return 0;
  79 }
  80 #endif  /* CONFIG_EXT4_FS_POSIX_ACL */
  81