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/xattr.h>
  10
  11 /* Magic value in attribute blocks */
  12 #define EXT3_XATTR_MAGIC                0xEA020000
  13
  14 /* Maximum number of references to one attribute block */
  15 #define EXT3_XATTR_REFCOUNT_MAX         1024
  16
  17 /* Name indexes */
  18 #define EXT3_XATTR_INDEX_USER                   1
  19 #define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS       2
  20 #define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  21 #define EXT3_XATTR_INDEX_TRUSTED                4
  22 #define EXT3_XATTR_INDEX_LUSTRE                 5
  23 #define EXT3_XATTR_INDEX_SECURITY               6
  24
  25 struct ext3_xattr_header {
  26         __le32  h_magic;        /* magic number for identification */
  27         __le32  h_refcount;     /* reference count */
  28         __le32  h_blocks;       /* number of disk blocks used */
  29         __le32  h_hash;         /* hash value of all attributes */
  30         __u32   h_reserved[4];  /* zero right now */
  31 };
  32
  33 struct ext3_xattr_ibody_header {
  34         __le32  h_magic;        /* magic number for identification */
  35 };
  36
  37 struct ext3_xattr_entry {
  38         __u8    e_name_len;     /* length of name */
  39         __u8    e_name_index;   /* attribute name index */
  40         __le16  e_value_offs;   /* offset in disk block of value */
  41         __le32  e_value_block;  /* disk block attribute is stored on (n/i) */
  42         __le32  e_value_size;   /* size of attribute value */
  43         __le32  e_hash;         /* hash value of name and value */
  44         char    e_name[0];      /* attribute name */
  45 };
  46
  47 #define EXT3_XATTR_PAD_BITS             2
  48 #define EXT3_XATTR_PAD          (1<<EXT3_XATTR_PAD_BITS)
  49 #define EXT3_XATTR_ROUND                (EXT3_XATTR_PAD-1)
  50 #define EXT3_XATTR_LEN(name_len) \
  51         (((name_len) + EXT3_XATTR_ROUND + \
  52         sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
  53 #define EXT3_XATTR_NEXT(entry) \
  54         ( (struct ext3_xattr_entry *)( \
  55           (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
  56 #define EXT3_XATTR_SIZE(size) \
  57         (((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
  58
  59 # ifdef CONFIG_EXT3_FS_XATTR
  60
  61 extern const struct xattr_handler ext3_xattr_user_handler;
  62 extern const struct xattr_handler ext3_xattr_trusted_handler;
  63 extern const struct xattr_handler ext3_xattr_acl_access_handler;
  64 extern const struct xattr_handler ext3_xattr_acl_default_handler;
  65 extern const struct xattr_handler ext3_xattr_security_handler;
  66
  67 extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
  68
  69 extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
  70 extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  71 extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
  72
  73 extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
  74 extern void ext3_xattr_put_super(struct super_block *);
  75
  76 extern int init_ext3_xattr(void);
  77 extern void exit_ext3_xattr(void);
  78
  79 extern const struct xattr_handler *ext3_xattr_handlers[];
  80
  81 # else  /* CONFIG_EXT3_FS_XATTR */
  82
  83 static inline int
  84 ext3_xattr_get(struct inode *inode, int name_index, const char *name,
  85                void *buffer, size_t size, int flags)
  86 {
  87         return -EOPNOTSUPP;
  88 }
  89
  90 static inline int
  91 ext3_xattr_set(struct inode *inode, int name_index, const char *name,
  92                const void *value, size_t size, int flags)
  93 {
  94         return -EOPNOTSUPP;
  95 }
  96
  97 static inline int
  98 ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
  99                const char *name, const void *value, size_t size, int flags)
 100 {
 101         return -EOPNOTSUPP;
 102 }
 103
 104 static inline void
 105 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
 106 {
 107 }
 108
 109 static inline void
 110 ext3_xattr_put_super(struct super_block *sb)
 111 {
 112 }
 113
 114 static inline int
 115 init_ext3_xattr(void)
 116 {
 117         return 0;
 118 }
 119
 120 static inline void
 121 exit_ext3_xattr(void)
 122 {
 123 }
 124
 125 #define ext3_xattr_handlers     NULL
 126
 127 # endif  /* CONFIG_EXT3_FS_XATTR */
 128
 129 #ifdef CONFIG_EXT3_FS_SECURITY
 130 extern int ext3_init_security(handle_t *handle, struct inode *inode,
 131                                 struct inode *dir);
 132 #else
 133 static inline int ext3_init_security(handle_t *handle, struct inode *inode,
 134                                 struct inode *dir)
 135 {
 136         return 0;
 137 }
 138 #endif