LXR linux/fs/ext4/xattr.h

   1/*
   2  File: fs/ext4/xattr.h
   3
   4  On-disk format of extended attributes for the ext4 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 EXT4_XATTR_MAGIC                0xEA020000
  13
  14/* Maximum number of references to one attribute block */
  15#define EXT4_XATTR_REFCOUNT_MAX         1024
  16
  17/* Name indexes */
  18#define EXT4_XATTR_INDEX_USER                   1
  19#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS       2
  20#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  21#define EXT4_XATTR_INDEX_TRUSTED                4
  22#define EXT4_XATTR_INDEX_LUSTRE                 5
  23#define EXT4_XATTR_INDEX_SECURITY               6
  24
  25struct ext4_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
  33struct ext4_xattr_ibody_header {
  34        __le32  h_magic;        /* magic number for identification */
  35};
  36
  37struct ext4_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 EXT4_XATTR_PAD_BITS             2
  48#define EXT4_XATTR_PAD          (1<<EXT4_XATTR_PAD_BITS)
  49#define EXT4_XATTR_ROUND                (EXT4_XATTR_PAD-1)
  50#define EXT4_XATTR_LEN(name_len) \
  51        (((name_len) + EXT4_XATTR_ROUND + \
  52        sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
  53#define EXT4_XATTR_NEXT(entry) \
  54        ((struct ext4_xattr_entry *)( \
  55         (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
  56#define EXT4_XATTR_SIZE(size) \
  57        (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
  58
  59#define IHDR(inode, raw_inode) \
  60        ((struct ext4_xattr_ibody_header *) \
  61                ((void *)raw_inode + \
  62                EXT4_GOOD_OLD_INODE_SIZE + \
  63                EXT4_I(inode)->i_extra_isize))
  64#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
  65
  66# ifdef CONFIG_EXT4_FS_XATTR
  67
  68extern struct xattr_handler ext4_xattr_user_handler;
  69extern struct xattr_handler ext4_xattr_trusted_handler;
  70extern struct xattr_handler ext4_xattr_acl_access_handler;
  71extern struct xattr_handler ext4_xattr_acl_default_handler;
  72extern struct xattr_handler ext4_xattr_security_handler;
  73
  74extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
  75
  76extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
  77extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  78extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
  79
  80extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
  81extern void ext4_xattr_put_super(struct super_block *);
  82
  83extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
  84                            struct ext4_inode *raw_inode, handle_t *handle);
  85
  86extern int init_ext4_xattr(void);
  87extern void exit_ext4_xattr(void);
  88
  89extern struct xattr_handler *ext4_xattr_handlers[];
  90
  91# else  /* CONFIG_EXT4_FS_XATTR */
  92
  93static inline int
  94ext4_xattr_get(struct inode *inode, int name_index, const char *name,
  95               void *buffer, size_t size, int flags)
  96{
  97        return -EOPNOTSUPP;
  98}
  99
 100static inline int
 101ext4_xattr_set(struct inode *inode, int name_index, const char *name,
 102               const void *value, size_t size, int flags)
 103{
 104        return -EOPNOTSUPP;
 105}
 106
 107static inline int
 108ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 109               const char *name, const void *value, size_t size, int flags)
 110{
 111        return -EOPNOTSUPP;
 112}
 113
 114static inline void
 115ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
 116{
 117}
 118
 119static inline void
 120ext4_xattr_put_super(struct super_block *sb)
 121{
 122}
 123
 124static inline int
 125init_ext4_xattr(void)
 126{
 127        return 0;
 128}
 129
 130static inline void
 131exit_ext4_xattr(void)
 132{
 133}
 134
 135static inline int
 136ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 137                            struct ext4_inode *raw_inode, handle_t *handle)
 138{
 139        return -EOPNOTSUPP;
 140}
 141
 142#define ext4_xattr_handlers     NULL
 143
 144# endif  /* CONFIG_EXT4_FS_XATTR */
 145
 146#ifdef CONFIG_EXT4_FS_SECURITY
 147extern int ext4_init_security(handle_t *handle, struct inode *inode,
 148                                struct inode *dir);
 149#else
 150static inline int ext4_init_security(handle_t *handle, struct inode *inode,
 151                                struct inode *dir)
 152{
 153        return 0;
 154}
 155#endif
 156