fs/ext3/xattr.h

   1 /*
   2   File: fs/ext3/xattr.h
   3
   4   On-disk format of extended attributes for the ext3 filesystem.
   5
   6   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   7 */
   8
   9 #include <linux/config.h>
  10 #include <linux/xattr.h>
  11
  12 /* Magic value in attribute blocks */
  13 #define EXT3_XATTR_MAGIC                0xEA020000
  14
  15 /* Maximum number of references to one attribute block */
  16 #define EXT3_XATTR_REFCOUNT_MAX         1024
  17
  18 /* Name indexes */
  19 #define EXT3_XATTR_INDEX_USER                   1
  20 #define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS       2
  21 #define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  22 #define EXT3_XATTR_INDEX_TRUSTED                4
  23 #define EXT3_XATTR_INDEX_LUSTRE                 5
  24 #define EXT3_XATTR_INDEX_SECURITY               6
  25
  26 struct ext3_xattr_header {
  27         __le32  h_magic;        /* magic number for identification */
  28         __le32  h_refcount;     /* reference count */
  29         __le32  h_blocks;       /* number of disk blocks used */
  30         __le32  h_hash;         /* hash value of all attributes */
  31         __u32   h_reserved[4];  /* zero right now */
  32 };
  33
  34 struct ext3_xattr_ibody_header {
  35         __le32  h_magic;        /* magic number for identification */
  36 };
  37
  38 struct ext3_xattr_entry {
  39         __u8    e_name_len;     /* length of name */
  40         __u8    e_name_index;   /* attribute name index */
  41         __le16  e_value_offs;   /* offset in disk block of value */
  42         __le32  e_value_block;  /* disk block attribute is stored on (n/i) */
  43         __le32  e_value_size;   /* size of attribute value */
  44         __le32  e_hash;         /* hash value of name and value */
  45         char    e_name[0];      /* attribute name */
  46 };
  47
  48 #define EXT3_XATTR_PAD_BITS             2
  49 #define EXT3_XATTR_PAD          (1<<EXT3_XATTR_PAD_BITS)
  50 #define EXT3_XATTR_ROUND                (EXT3_XATTR_PAD-1)
  51 #define EXT3_XATTR_LEN(name_len) \
  52         (((name_len) + EXT3_XATTR_ROUND + \
  53         sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
  54 #define EXT3_XATTR_NEXT(entry) \
  55         ( (struct ext3_xattr_entry *)( \
  56           (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
  57 #define EXT3_XATTR_SIZE(size) \
  58         (((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
  59
  60 # ifdef CONFIG_EXT3_FS_XATTR
  61
  62 extern struct xattr_handler ext3_xattr_user_handler;
  63 extern struct xattr_handler ext3_xattr_trusted_handler;
  64 extern struct xattr_handler ext3_xattr_acl_access_handler;
  65 extern struct xattr_handler ext3_xattr_acl_default_handler;
  66 extern struct xattr_handler ext3_xattr_security_handler;
  67
  68 extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
  69
  70 extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
  71 extern int ext3_xattr_list(struct inode *, char *, size_t);
  72 extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  73 extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
  74
  75 extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
  76 extern void ext3_xattr_put_super(struct super_block *);
  77
  78 extern int init_ext3_xattr(void);
  79 extern void exit_ext3_xattr(void);
  80
  81 extern struct xattr_handler *ext3_xattr_handlers[];
  82
  83 # else  /* CONFIG_EXT3_FS_XATTR */
  84
  85 static inline int
  86 ext3_xattr_get(struct inode *inode, int name_index, const char *name,
  87                void *buffer, size_t size, int flags)
  88 {
  89         return -EOPNOTSUPP;
  90 }
  91
  92 static inline int
  93 ext3_xattr_list(struct inode *inode, void *buffer, size_t size)
  94 {
  95         return -EOPNOTSUPP;
  96 }
  97
  98 static inline int
  99 ext3_xattr_set(struct inode *inode, int name_index, const char *name,
 100                const void *value, size_t size, int flags)
 101 {
 102         return -EOPNOTSUPP;
 103 }
 104
 105 static inline int
 106 ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 107                const char *name, const void *value, size_t size, int flags)
 108 {
 109         return -EOPNOTSUPP;
 110 }
 111
 112 static inline void
 113 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
 114 {
 115 }
 116
 117 static inline void
 118 ext3_xattr_put_super(struct super_block *sb)
 119 {
 120 }
 121
 122 static inline int
 123 init_ext3_xattr(void)
 124 {
 125         return 0;
 126 }
 127
 128 static inline void
 129 exit_ext3_xattr(void)
 130 {
 131 }
 132
 133 #define ext3_xattr_handlers     NULL
 134
 135 # endif  /* CONFIG_EXT3_FS_XATTR */