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_security_handler;
  64
  65 extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
  66
  67 extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
  68 extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  69 extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
  70
  71 extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
  72 extern void ext3_xattr_put_super(struct super_block *);
  73
  74 extern int init_ext3_xattr(void);
  75 extern void exit_ext3_xattr(void);
  76
  77 extern const struct xattr_handler *ext3_xattr_handlers[];
  78
  79 # else  /* CONFIG_EXT3_FS_XATTR */
  80
  81 static inline int
  82 ext3_xattr_get(struct inode *inode, int name_index, const char *name,
  83                void *buffer, size_t size, int flags)
  84 {
  85         return -EOPNOTSUPP;
  86 }
  87
  88 static inline int
  89 ext3_xattr_set(struct inode *inode, int name_index, const char *name,
  90                const void *value, size_t size, int flags)
  91 {
  92         return -EOPNOTSUPP;
  93 }
  94
  95 static inline int
  96 ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
  97                const char *name, const void *value, size_t size, int flags)
  98 {
  99         return -EOPNOTSUPP;
 100 }
 101
 102 static inline void
 103 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
 104 {
 105 }
 106
 107 static inline void
 108 ext3_xattr_put_super(struct super_block *sb)
 109 {
 110 }
 111
 112 static inline int
 113 init_ext3_xattr(void)
 114 {
 115         return 0;
 116 }
 117
 118 static inline void
 119 exit_ext3_xattr(void)
 120 {
 121 }
 122
 123 #define ext3_xattr_handlers     NULL
 124
 125 # endif  /* CONFIG_EXT3_FS_XATTR */
 126
 127 #ifdef CONFIG_EXT3_FS_SECURITY
 128 extern int ext3_init_security(handle_t *handle, struct inode *inode,
 129                               struct inode *dir, const struct qstr *qstr);
 130 #else
 131 static inline int ext3_init_security(handle_t *handle, struct inode *inode,
 132                                      struct inode *dir, const struct qstr *qstr)
 133 {
 134         return 0;
 135 }
 136 #endif