fs/f2fs/xattr.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * fs/f2fs/xattr.h
   4  *
   5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6  *             http://www.samsung.com/
   7  *
   8  * Portions of this code from linux/fs/ext2/xattr.h
   9  *
  10  * On-disk format of extended attributes for the ext2 filesystem.
  11  *
  12  * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
  13  */
  14 #ifndef __F2FS_XATTR_H__
  15 #define __F2FS_XATTR_H__
  16
  17 #include <linux/init.h>
  18 #include <linux/xattr.h>
  19
  20 /* Magic value in attribute blocks */
  21 #define F2FS_XATTR_MAGIC                0xF2F52011
  22
  23 /* Maximum number of references to one attribute block */
  24 #define F2FS_XATTR_REFCOUNT_MAX         1024
  25
  26 /* Name indexes */
  27 #define F2FS_SYSTEM_ADVISE_NAME                 "system.advise"
  28 #define F2FS_XATTR_INDEX_USER                   1
  29 #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS       2
  30 #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  31 #define F2FS_XATTR_INDEX_TRUSTED                4
  32 #define F2FS_XATTR_INDEX_LUSTRE                 5
  33 #define F2FS_XATTR_INDEX_SECURITY               6
  34 #define F2FS_XATTR_INDEX_ADVISE                 7
  35 /* Should be same as EXT4_XATTR_INDEX_ENCRYPTION */
  36 #define F2FS_XATTR_INDEX_ENCRYPTION             9
  37
  38 #define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT      "c"
  39
  40 struct f2fs_xattr_header {
  41         __le32  h_magic;        /* magic number for identification */
  42         __le32  h_refcount;     /* reference count */
  43         __u32   h_reserved[4];  /* zero right now */
  44 };
  45
  46 struct f2fs_xattr_entry {
  47         __u8    e_name_index;
  48         __u8    e_name_len;
  49         __le16  e_value_size;   /* size of attribute value */
  50         char    e_name[0];      /* attribute name */
  51 };
  52
  53 #define XATTR_HDR(ptr)          ((struct f2fs_xattr_header *)(ptr))
  54 #define XATTR_ENTRY(ptr)        ((struct f2fs_xattr_entry *)(ptr))
  55 #define XATTR_FIRST_ENTRY(ptr)  (XATTR_ENTRY(XATTR_HDR(ptr) + 1))
  56 #define XATTR_ROUND             (3)
  57
  58 #define XATTR_ALIGN(size)       (((size) + XATTR_ROUND) & ~XATTR_ROUND)
  59
  60 #define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
  61                         (entry)->e_name_len + le16_to_cpu((entry)->e_value_size)))
  62
  63 #define XATTR_NEXT_ENTRY(entry) ((struct f2fs_xattr_entry *)((char *)(entry) +\
  64                         ENTRY_SIZE(entry)))
  65
  66 #define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
  67
  68 #define list_for_each_xattr(entry, addr) \
  69                 for (entry = XATTR_FIRST_ENTRY(addr);\
  70                                 !IS_XATTR_LAST_ENTRY(entry);\
  71                                 entry = XATTR_NEXT_ENTRY(entry))
  72 #define VALID_XATTR_BLOCK_SIZE  (PAGE_SIZE - sizeof(struct node_footer))
  73 #define XATTR_PADDING_SIZE      (sizeof(__u32))
  74 #define MIN_OFFSET(i)           XATTR_ALIGN(inline_xattr_size(i) +      \
  75                                                 VALID_XATTR_BLOCK_SIZE)
  76
  77 #define MAX_VALUE_LEN(i)        (MIN_OFFSET(i) -                        \
  78                                 sizeof(struct f2fs_xattr_header) -      \
  79                                 sizeof(struct f2fs_xattr_entry))
  80
  81 /*
  82  * On-disk structure of f2fs_xattr
  83  * We use inline xattrs space + 1 block for xattr.
  84  *
  85  * +--------------------+
  86  * | f2fs_xattr_header  |
  87  * |                    |
  88  * +--------------------+
  89  * | f2fs_xattr_entry   |
  90  * | .e_name_index = 1  |
  91  * | .e_name_len = 3    |
  92  * | .e_value_size = 14 |
  93  * | .e_name = "foo"    |
  94  * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
  95  * +--------------------+
  96  * | f2fs_xattr_entry   |
  97  * | .e_name_index = 4  |
  98  * | .e_name = "bar"    |
  99  * +--------------------+
 100  * |                    |
 101  * |        Free        |
 102  * |                    |
 103  * +--------------------+<- MIN_OFFSET
 104  * |   node_footer      |
 105  * | (nid, ino, offset) |
 106  * +--------------------+
 107  *
 108  **/
 109
 110 #ifdef CONFIG_F2FS_FS_XATTR
 111 extern const struct xattr_handler f2fs_xattr_user_handler;
 112 extern const struct xattr_handler f2fs_xattr_trusted_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 *, int);
 120 extern int f2fs_getxattr(struct inode *, int, const char *, void *,
 121                                                 size_t, struct page *);
 122 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
 123 #else
 124
 125 #define f2fs_xattr_handlers     NULL
 126 static inline int f2fs_setxattr(struct inode *inode, int index,
 127                 const char *name, const void *value, size_t size,
 128                 struct page *page, int flags)
 129 {
 130         return -EOPNOTSUPP;
 131 }
 132 static inline int f2fs_getxattr(struct inode *inode, int index,
 133                         const char *name, void *buffer,
 134                         size_t buffer_size, struct page *dpage)
 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 #ifdef CONFIG_F2FS_FS_SECURITY
 146 extern int f2fs_init_security(struct inode *, struct inode *,
 147                                 const struct qstr *, struct page *);
 148 #else
 149 static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
 150                                 const struct qstr *qstr, struct page *ipage)
 151 {
 152         return 0;
 153 }
 154 #endif
 155 #endif /* __F2FS_XATTR_H__ */