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 73 #define MIN_OFFSET XATTR_ALIGN(PAGE_SIZE - \ 74 sizeof(struct node_footer) - \ 75 sizeof(__u32)) 76 77 #define MAX_VALUE_LEN (MIN_OFFSET - sizeof(struct f2fs_xattr_header) - \ 78 sizeof(struct f2fs_xattr_entry)) 79 80 /* 81 * On-disk structure of f2fs_xattr 82 * We use only 1 block for xattr. 83 * 84 * +--------------------+ 85 * | f2fs_xattr_header | 86 * | | 87 * +--------------------+ 88 * | f2fs_xattr_entry | 89 * | .e_name_index = 1 | 90 * | .e_name_len = 3 | 91 * | .e_value_size = 14 | 92 * | .e_name = "foo" | 93 * | "value_of_xattr" |<- value_offs = e_name + e_name_len 94 * +--------------------+ 95 * | f2fs_xattr_entry | 96 * | .e_name_index = 4 | 97 * | .e_name = "bar" | 98 * +--------------------+ 99 * | | 100 * | Free | 101 * | | 102 * +--------------------+<- MIN_OFFSET 103 * | node_footer | 104 * | (nid, ino, offset) | 105 * +--------------------+ 106 * 107 **/ 108 109 #ifdef CONFIG_F2FS_FS_XATTR 110 extern const struct xattr_handler f2fs_xattr_user_handler; 111 extern const struct xattr_handler f2fs_xattr_trusted_handler; 112 extern const struct xattr_handler f2fs_xattr_acl_access_handler; 113 extern const struct xattr_handler f2fs_xattr_acl_default_handler; 114 extern const struct xattr_handler f2fs_xattr_advise_handler; 115 116 extern const struct xattr_handler *f2fs_xattr_handlers[]; 117 118 extern int f2fs_setxattr(struct inode *inode, int name_index, const char *name, 119 const void *value, size_t value_len); 120 extern int f2fs_getxattr(struct inode *inode, int name_index, const char *name, 121 void *buffer, size_t buffer_size); 122 extern ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, 123 size_t buffer_size); 124 125 #else 126 127 #define f2fs_xattr_handlers NULL 128 static inline int f2fs_setxattr(struct inode *inode, int name_index, 129 const char *name, const void *value, size_t value_len) 130 { 131 return -EOPNOTSUPP; 132 } 133 static inline int f2fs_getxattr(struct inode *inode, int name_index, 134 const char *name, void *buffer, size_t buffer_size) 135 { 136 return -EOPNOTSUPP; 137 } 138 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, 139 size_t buffer_size) 140 { 141 return -EOPNOTSUPP; 142 } 143 #endif 144 145 #endif /* __F2FS_XATTR_H__ */ 146