1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 File: linux/ext2_xattr.h 4 5 On-disk format of extended attributes for the ext2 filesystem. 6 7 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> 8 */ 9 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[]; /* 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 struct mb_cache; 58 59 # ifdef CONFIG_EXT2_FS_XATTR 60 61 extern const struct xattr_handler ext2_xattr_user_handler; 62 extern const struct xattr_handler ext2_xattr_trusted_handler; 63 extern const 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 72 extern struct mb_cache *ext2_xattr_create_cache(void); 73 extern void ext2_xattr_destroy_cache(struct mb_cache *cache); 74 75 extern const struct xattr_handler * const ext2_xattr_handlers[]; 76 77 # else /* CONFIG_EXT2_FS_XATTR */ 78 79 static inline int 80 ext2_xattr_get(struct inode *inode, int name_index, 81 const char *name, void *buffer, size_t size) 82 { 83 return -EOPNOTSUPP; 84 } 85 86 static inline int 87 ext2_xattr_set(struct inode *inode, int name_index, const char *name, 88 const void *value, size_t size, int flags) 89 { 90 return -EOPNOTSUPP; 91 } 92 93 static inline void 94 ext2_xattr_delete_inode(struct inode *inode) 95 { 96 } 97 98 static inline void ext2_xattr_destroy_cache(struct mb_cache *cache) 99 { 100 } 101 102 #define ext2_xattr_handlers NULL 103 #define ext2_listxattr NULL 104 105 # endif /* CONFIG_EXT2_FS_XATTR */ 106 107 #ifdef CONFIG_EXT2_FS_SECURITY 108 extern int ext2_init_security(struct inode *inode, struct inode *dir, 109 const struct qstr *qstr); 110 #else 111 static inline int ext2_init_security(struct inode *inode, struct inode *dir, 112 const struct qstr *qstr) 113 { 114 return 0; 115 } 116 #endif 117