| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | File: linux/ext2_xattr.h |
| 3 | |
| 4 | On-disk format of extended attributes for the ext2 filesystem. |
| 5 | |
| 6 | (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> |
| 7 | */ |
| 8 | |
| 9 | #include <linux/config.h> |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/xattr.h> |
| 12 | |
| 13 | /* Magic value in attribute blocks */ |
| 14 | #define EXT2_XATTR_MAGIC 0xEA020000 |
| 15 | |
| 16 | /* Maximum number of references to one attribute block */ |
| 17 | #define EXT2_XATTR_REFCOUNT_MAX 1024 |
| 18 | |
| 19 | /* Name indexes */ |
| 20 | #define EXT2_XATTR_INDEX_USER 1 |
| 21 | #define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2 |
| 22 | #define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3 |
| 23 | #define EXT2_XATTR_INDEX_TRUSTED 4 |
| 24 | #define EXT2_XATTR_INDEX_LUSTRE 5 |
| 25 | #define EXT2_XATTR_INDEX_SECURITY 6 |
| 26 | |
| 27 | struct ext2_xattr_header { |
| 28 | __le32 h_magic; /* magic number for identification */ |
| 29 | __le32 h_refcount; /* reference count */ |
| 30 | __le32 h_blocks; /* number of disk blocks used */ |
| 31 | __le32 h_hash; /* hash value of all attributes */ |
| 32 | __u32 h_reserved[4]; /* zero right now */ |
| 33 | }; |
| 34 | |
| 35 | struct ext2_xattr_entry { |
| 36 | __u8 e_name_len; /* length of name */ |
| 37 | __u8 e_name_index; /* attribute name index */ |
| 38 | __le16 e_value_offs; /* offset in disk block of value */ |
| 39 | __le32 e_value_block; /* disk block attribute is stored on (n/i) */ |
| 40 | __le32 e_value_size; /* size of attribute value */ |
| 41 | __le32 e_hash; /* hash value of name and value */ |
| 42 | char e_name[0]; /* attribute name */ |
| 43 | }; |
| 44 | |
| 45 | #define EXT2_XATTR_PAD_BITS 2 |
| 46 | #define EXT2_XATTR_PAD (1<<EXT2_XATTR_PAD_BITS) |
| 47 | #define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1) |
| 48 | #define EXT2_XATTR_LEN(name_len) \ |
| 49 | (((name_len) + EXT2_XATTR_ROUND + \ |
| 50 | sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND) |
| 51 | #define EXT2_XATTR_NEXT(entry) \ |
| 52 | ( (struct ext2_xattr_entry *)( \ |
| 53 | (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) ) |
| 54 | #define EXT2_XATTR_SIZE(size) \ |
| 55 | (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND) |
| 56 | |
| 57 | # ifdef CONFIG_EXT2_FS_XATTR |
| 58 | |
| 59 | extern struct xattr_handler ext2_xattr_user_handler; |
| 60 | extern struct xattr_handler ext2_xattr_trusted_handler; |
| 61 | extern struct xattr_handler ext2_xattr_acl_access_handler; |
| 62 | extern struct xattr_handler ext2_xattr_acl_default_handler; |
| 63 | extern struct xattr_handler ext2_xattr_security_handler; |
| 64 | |
| 65 | extern ssize_t ext2_listxattr(struct dentry *, char *, size_t); |
| 66 | |
| 67 | extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t); |
| 68 | extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int); |
| 69 | |
| 70 | extern void ext2_xattr_delete_inode(struct inode *); |
| 71 | extern void ext2_xattr_put_super(struct super_block *); |
| 72 | |
| 73 | extern int init_ext2_xattr(void); |
| 74 | extern void exit_ext2_xattr(void); |
| 75 | |
| 76 | extern struct xattr_handler *ext2_xattr_handlers[]; |
| 77 | |
| 78 | # else /* CONFIG_EXT2_FS_XATTR */ |
| 79 | |
| 80 | static inline int |
| 81 | ext2_xattr_get(struct inode *inode, int name_index, |
| 82 | const char *name, void *buffer, size_t size) |
| 83 | { |
| 84 | return -EOPNOTSUPP; |
| 85 | } |
| 86 | |
| 87 | static inline int |
| 88 | ext2_xattr_set(struct inode *inode, int name_index, const char *name, |
| 89 | const void *value, size_t size, int flags) |
| 90 | { |
| 91 | return -EOPNOTSUPP; |
| 92 | } |
| 93 | |
| 94 | static inline void |
| 95 | ext2_xattr_delete_inode(struct inode *inode) |
| 96 | { |
| 97 | } |
| 98 | |
| 99 | static inline void |
| 100 | ext2_xattr_put_super(struct super_block *sb) |
| 101 | { |
| 102 | } |
| 103 | |
| 104 | static inline int |
| 105 | init_ext2_xattr(void) |
| 106 | { |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static inline void |
| 111 | exit_ext2_xattr(void) |
| 112 | { |
| 113 | } |
| 114 | |
| 115 | #define ext2_xattr_handlers NULL |
| 116 | |
| 117 | # endif /* CONFIG_EXT2_FS_XATTR */ |
| 118 | |