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_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 /* 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
  76 #define MIN_OFFSET(i)   XATTR_ALIGN(inline_xattr_size(i) + PAGE_SIZE -  \
  77                                 sizeof(struct node_footer) - sizeof(__u32))
  78
  79 #define MAX_VALUE_LEN(i)        (MIN_OFFSET(i) -                        \
  80                                 sizeof(struct f2fs_xattr_header) -      \
  81                                 sizeof(struct f2fs_xattr_entry))
  82
  83 /*
  84  * On-disk structure of f2fs_xattr
  85  * We use inline xattrs space + 1 block for xattr.
  86  *
  87  * +--------------------+
  88  * | f2fs_xattr_header  |
  89  * |                    |
  90  * +--------------------+
  91  * | f2fs_xattr_entry   |
  92  * | .e_name_index = 1  |
  93  * | .e_name_len = 3    |
  94  * | .e_value_size = 14 |
  95  * | .e_name = "foo"    |
  96  * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
  97  * +--------------------+
  98  * | f2fs_xattr_entry   |
  99  * | .e_name_index = 4  |
 100  * | .e_name = "bar"    |
 101  * +--------------------+
 102  * |                    |
 103  * |        Free        |
 104  * |                    |
 105  * +--------------------+<- MIN_OFFSET
 106  * |   node_footer      |
 107  * | (nid, ino, offset) |
 108  * +--------------------+
 109  *
 110  **/
 111
 112 #ifdef CONFIG_F2FS_FS_XATTR
 113 extern const struct xattr_handler f2fs_xattr_user_handler;
 114 extern const struct xattr_handler f2fs_xattr_trusted_handler;
 115 extern const struct xattr_handler f2fs_xattr_advise_handler;
 116 extern const struct xattr_handler f2fs_xattr_security_handler;
 117
 118 extern const struct xattr_handler *f2fs_xattr_handlers[];
 119
 120 extern int f2fs_setxattr(struct inode *, int, const char *,
 121                                 const void *, size_t, struct page *, int);
 122 extern int f2fs_getxattr(struct inode *, int, const char *, void *,
 123                                                 size_t, struct page *);
 124 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
 125 #else
 126
 127 #define f2fs_xattr_handlers     NULL
 128 static inline int f2fs_setxattr(struct inode *inode, int index,
 129                 const char *name, const void *value, size_t size, int flags)
 130 {
 131         return -EOPNOTSUPP;
 132 }
 133 static inline int f2fs_getxattr(struct inode *inode, int index,
 134                         const char *name, void *buffer,
 135                         size_t buffer_size, struct page *dpage)
 136 {
 137         return -EOPNOTSUPP;
 138 }
 139 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
 140                 size_t buffer_size)
 141 {
 142         return -EOPNOTSUPP;
 143 }
 144 #endif
 145
 146 #ifdef CONFIG_F2FS_FS_SECURITY
 147 extern int f2fs_init_security(struct inode *, struct inode *,
 148                                 const struct qstr *, struct page *);
 149 #else
 150 static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
 151                                 const struct qstr *qstr, struct page *ipage)
 152 {
 153         return 0;
 154 }
 155 #endif
 156 #endif /* __F2FS_XATTR_H__ */