fs/f2fs/xattr.h

   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_NAME                 "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 /* Should be same as EXT4_XATTR_INDEX_ENCRYPTION */
  39 #define F2FS_XATTR_INDEX_ENCRYPTION             9
  40
  41 #define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT      "c"
  42
  43 struct f2fs_xattr_header {
  44         __le32  h_magic;        /* magic number for identification */
  45         __le32  h_refcount;     /* reference count */
  46         __u32   h_reserved[4];  /* zero right now */
  47 };
  48
  49 struct f2fs_xattr_entry {
  50         __u8    e_name_index;
  51         __u8    e_name_len;
  52         __le16  e_value_size;   /* size of attribute value */
  53         char    e_name[0];      /* attribute name */
  54 };
  55
  56 #define XATTR_HDR(ptr)          ((struct f2fs_xattr_header *)(ptr))
  57 #define XATTR_ENTRY(ptr)        ((struct f2fs_xattr_entry *)(ptr))
  58 #define XATTR_FIRST_ENTRY(ptr)  (XATTR_ENTRY(XATTR_HDR(ptr) + 1))
  59 #define XATTR_ROUND             (3)
  60
  61 #define XATTR_ALIGN(size)       (((size) + XATTR_ROUND) & ~XATTR_ROUND)
  62
  63 #define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
  64                         (entry)->e_name_len + le16_to_cpu((entry)->e_value_size)))
  65
  66 #define XATTR_NEXT_ENTRY(entry) ((struct f2fs_xattr_entry *)((char *)(entry) +\
  67                         ENTRY_SIZE(entry)))
  68
  69 #define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
  70
  71 #define list_for_each_xattr(entry, addr) \
  72                 for (entry = XATTR_FIRST_ENTRY(addr);\
  73                                 !IS_XATTR_LAST_ENTRY(entry);\
  74                                 entry = XATTR_NEXT_ENTRY(entry))
  75 #define VALID_XATTR_BLOCK_SIZE  (PAGE_SIZE - sizeof(struct node_footer))
  76 #define XATTR_PADDING_SIZE      (sizeof(__u32))
  77 #define MIN_OFFSET(i)           XATTR_ALIGN(inline_xattr_size(i) +      \
  78                                                 VALID_XATTR_BLOCK_SIZE)
  79
  80 #define MAX_VALUE_LEN(i)        (MIN_OFFSET(i) -                        \
  81                                 sizeof(struct f2fs_xattr_header) -      \
  82                                 sizeof(struct f2fs_xattr_entry))
  83
  84 /*
  85  * On-disk structure of f2fs_xattr
  86  * We use inline xattrs space + 1 block for xattr.
  87  *
  88  * +--------------------+
  89  * | f2fs_xattr_header  |
  90  * |                    |
  91  * +--------------------+
  92  * | f2fs_xattr_entry   |
  93  * | .e_name_index = 1  |
  94  * | .e_name_len = 3    |
  95  * | .e_value_size = 14 |
  96  * | .e_name = "foo"    |
  97  * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
  98  * +--------------------+
  99  * | f2fs_xattr_entry   |
 100  * | .e_name_index = 4  |
 101  * | .e_name = "bar"    |
 102  * +--------------------+
 103  * |                    |
 104  * |        Free        |
 105  * |                    |
 106  * +--------------------+<- MIN_OFFSET
 107  * |   node_footer      |
 108  * | (nid, ino, offset) |
 109  * +--------------------+
 110  *
 111  **/
 112
 113 #ifdef CONFIG_F2FS_FS_XATTR
 114 extern const struct xattr_handler f2fs_xattr_user_handler;
 115 extern const struct xattr_handler f2fs_xattr_trusted_handler;
 116 extern const struct xattr_handler f2fs_xattr_advise_handler;
 117 extern const struct xattr_handler f2fs_xattr_security_handler;
 118
 119 extern const struct xattr_handler *f2fs_xattr_handlers[];
 120
 121 extern int f2fs_setxattr(struct inode *, int, const char *,
 122                                 const void *, size_t, struct page *, int);
 123 extern int f2fs_getxattr(struct inode *, int, const char *, void *,
 124                                                 size_t, struct page *);
 125 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
 126 #else
 127
 128 #define f2fs_xattr_handlers     NULL
 129 static inline int f2fs_setxattr(struct inode *inode, int index,
 130                 const char *name, const void *value, size_t size,
 131                 struct page *page, int flags)
 132 {
 133         return -EOPNOTSUPP;
 134 }
 135 static inline int f2fs_getxattr(struct inode *inode, int index,
 136                         const char *name, void *buffer,
 137                         size_t buffer_size, struct page *dpage)
 138 {
 139         return -EOPNOTSUPP;
 140 }
 141 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
 142                 size_t buffer_size)
 143 {
 144         return -EOPNOTSUPP;
 145 }
 146 #endif
 147
 148 #ifdef CONFIG_F2FS_FS_SECURITY
 149 extern int f2fs_init_security(struct inode *, struct inode *,
 150                                 const struct qstr *, struct page *);
 151 #else
 152 static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
 153                                 const struct qstr *qstr, struct page *ipage)
 154 {
 155         return 0;
 156 }
 157 #endif
 158 #endif /* __F2FS_XATTR_H__ */