1 /* 2 * fs/f2fs/xattr.h 3 * 4 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 5 * http://www.samsung.com/ 6 * 7 * Portions of this code from linux/fs/ext2/xattr.h 8 * 9 * On-disk format of extended attributes for the ext2 filesystem. 10 * 11 * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License version 2 as 15 * published by the Free Software Foundation. 16 */ 17 #ifndef __F2FS_XATTR_H__ 18 #define __F2FS_XATTR_H__ 19 20 #include <linux/init.h> 21 #include <linux/xattr.h> 22 23 /* Magic value in attribute blocks */ 24 #define F2FS_XATTR_MAGIC 0xF2F52011 25 26 /* Maximum number of references to one attribute block */ 27 #define F2FS_XATTR_REFCOUNT_MAX 1024 28 29 /* Name indexes */ 30 #define F2FS_SYSTEM_ADVISE_PREFIX "system.advise" 31 #define F2FS_XATTR_INDEX_USER 1 32 #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS 2 33 #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT 3 34 #define F2FS_XATTR_INDEX_TRUSTED 4 35 #define F2FS_XATTR_INDEX_LUSTRE 5 36 #define F2FS_XATTR_INDEX_SECURITY 6 37 #define F2FS_XATTR_INDEX_ADVISE 7 38 39 struct f2fs_xattr_header { 40 __le32 h_magic; /* magic number for identification */ 41 __le32 h_refcount; /* reference count */ 42 __u32 h_reserved[4]; /* zero right now */ 43 }; 44 45 struct f2fs_xattr_entry { 46 __u8 e_name_index; 47 __u8 e_name_len; 48 __le16 e_value_size; /* size of attribute value */ 49 char e_name[0]; /* attribute name */ 50 }; 51 52 #define XATTR_HDR(ptr) ((struct f2fs_xattr_header *)(ptr)) 53 #define XATTR_ENTRY(ptr) ((struct f2fs_xattr_entry *)(ptr)) 54 #define XATTR_FIRST_ENTRY(ptr) (XATTR_ENTRY(XATTR_HDR(ptr) + 1)) 55 #define XATTR_ROUND (3) 56 57 #define XATTR_ALIGN(size) ((size + XATTR_ROUND) & ~XATTR_ROUND) 58 59 #define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \ 60 entry->e_name_len + le16_to_cpu(entry->e_value_size))) 61 62 #define XATTR_NEXT_ENTRY(entry) ((struct f2fs_xattr_entry *)((char *)(entry) +\ 63 ENTRY_SIZE(entry))) 64 65 #define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) 66 67 #define list_for_each_xattr(entry, addr) \ 68 for (entry = XATTR_FIRST_ENTRY(addr);\ 69 !IS_XATTR_LAST_ENTRY(entry);\ 70 entry = XATTR_NEXT_ENTRY(entry)) 71 72 #define MIN_OFFSET(i) XATTR_ALIGN(inline_xattr_size(i) + PAGE_SIZE - \ 73 sizeof(struct node_footer) - sizeof(__u32)) 74 75 #define MAX_VALUE_LEN(i) (MIN_OFFSET(i) - \ 76 sizeof(struct f2fs_xattr_header) - \ 77 sizeof(struct f2fs_xattr_entry)) 78 79 /* 80 * On-disk structure of f2fs_xattr 81 * We use inline xattrs space + 1 block for xattr. 82 * 83 * +--------------------+ 84 * | f2fs_xattr_header | 85 * | | 86 * +--------------------+ 87 * | f2fs_xattr_entry | 88 * | .e_name_index = 1 | 89 * | .e_name_len = 3 | 90 * | .e_value_size = 14 | 91 * | .e_name = "foo" | 92 * | "value_of_xattr" |<- value_offs = e_name + e_name_len 93 * +--------------------+ 94 * | f2fs_xattr_entry | 95 * | .e_name_index = 4 | 96 * | .e_name = "bar" | 97 * +--------------------+ 98 * | | 99 * | Free | 100 * | | 101 * +--------------------+<- MIN_OFFSET 102 * | node_footer | 103 * | (nid, ino, offset) | 104 * +--------------------+ 105 * 106 **/ 107 108 #ifdef CONFIG_F2FS_FS_XATTR 109 extern const struct xattr_handler f2fs_xattr_user_handler; 110 extern const struct xattr_handler f2fs_xattr_trusted_handler; 111 extern const struct xattr_handler f2fs_xattr_acl_access_handler; 112 extern const struct xattr_handler f2fs_xattr_acl_default_handler; 113 extern const struct xattr_handler f2fs_xattr_advise_handler; 114 extern const struct xattr_handler f2fs_xattr_security_handler; 115 116 extern const struct xattr_handler *f2fs_xattr_handlers[]; 117 118 extern int f2fs_setxattr(struct inode *, int, const char *, 119 const void *, size_t, struct page *); 120 extern int f2fs_getxattr(struct inode *, int, const char *, void *, size_t); 121 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t); 122 #else 123 124 #define f2fs_xattr_handlers NULL 125 static inline int f2fs_setxattr(struct inode *inode, int name_index, 126 const char *name, const void *value, size_t value_len) 127 { 128 return -EOPNOTSUPP; 129 } 130 static inline int f2fs_getxattr(struct inode *inode, int name_index, 131 const char *name, void *buffer, size_t buffer_size) 132 { 133 return -EOPNOTSUPP; 134 } 135 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, 136 size_t buffer_size) 137 { 138 return -EOPNOTSUPP; 139 } 140 #endif 141 142 #ifdef CONFIG_F2FS_FS_SECURITY 143 extern int f2fs_init_security(struct inode *, struct inode *, 144 const struct qstr *, struct page *); 145 #else 146 static inline int f2fs_init_security(struct inode *inode, struct inode *dir, 147 const struct qstr *qstr, struct page *ipage) 148 { 149 return 0; 150 } 151 #endif 152 #endif /* __F2FS_XATTR_H__ */ 153