fs/ext2/acl.h

   1 /*
   2   File: fs/ext2/acl.h
   3
   4   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   5 */
   6
   7 #include <linux/xattr_acl.h>
   8
   9 #define EXT2_ACL_VERSION        0x0001
  10 #define EXT2_ACL_MAX_ENTRIES    32
  11
  12 typedef struct {
  13         __le16          e_tag;
  14         __le16          e_perm;
  15         __le32          e_id;
  16 } ext2_acl_entry;
  17
  18 typedef struct {
  19         __le16          e_tag;
  20         __le16          e_perm;
  21 } ext2_acl_entry_short;
  22
  23 typedef struct {
  24         __le32          a_version;
  25 } ext2_acl_header;
  26
  27 static inline size_t ext2_acl_size(int count)
  28 {
  29         if (count <= 4) {
  30                 return sizeof(ext2_acl_header) +
  31                        count * sizeof(ext2_acl_entry_short);
  32         } else {
  33                 return sizeof(ext2_acl_header) +
  34                        4 * sizeof(ext2_acl_entry_short) +
  35                        (count - 4) * sizeof(ext2_acl_entry);
  36         }
  37 }
  38
  39 static inline int ext2_acl_count(size_t size)
  40 {
  41         ssize_t s;
  42         size -= sizeof(ext2_acl_header);
  43         s = size - 4 * sizeof(ext2_acl_entry_short);
  44         if (s < 0) {
  45                 if (size % sizeof(ext2_acl_entry_short))
  46                         return -1;
  47                 return size / sizeof(ext2_acl_entry_short);
  48         } else {
  49                 if (s % sizeof(ext2_acl_entry))
  50                         return -1;
  51                 return s / sizeof(ext2_acl_entry) + 4;
  52         }
  53 }
  54
  55 #ifdef CONFIG_EXT2_FS_POSIX_ACL
  56
  57 /* Value for inode->u.ext2_i.i_acl and inode->u.ext2_i.i_default_acl
  58    if the ACL has not been cached */
  59 #define EXT2_ACL_NOT_CACHED ((void *)-1)
  60
  61 /* acl.c */
  62 extern int ext2_permission (struct inode *, int, struct nameidata *);
  63 extern int ext2_acl_chmod (struct inode *);
  64 extern int ext2_init_acl (struct inode *, struct inode *);
  65
  66 extern int init_ext2_acl(void);
  67 extern void exit_ext2_acl(void);
  68
  69 #else
  70 #include <linux/sched.h>
  71 #define ext2_permission NULL
  72 #define ext2_get_acl    NULL
  73 #define ext2_set_acl    NULL
  74
  75 static inline int
  76 ext2_acl_chmod (struct inode *inode)
  77 {
  78         return 0;
  79 }
  80
  81 static inline int ext2_init_acl (struct inode *inode, struct inode *dir)
  82 {
  83         inode->i_mode &= ~current->fs->umask;
  84         return 0;
  85 }
  86 #endif
  87