LXR linux/fs/ext2/xattr.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3  File: linux/ext2_xattr.h
   4
   5  On-disk format of extended attributes for the ext2 filesystem.
   6
   7  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   8*/
   9
  10#include <linux/init.h>
  11#include <linux/xattr.h>
  12
  13/* Magic value in attribute blocks */
  14#define EXT2_XATTR_MAGIC                0xEA020000
  15
  16/* Maximum number of references to one attribute block */
  17#define EXT2_XATTR_REFCOUNT_MAX         1024
  18
  19/* Name indexes */
  20#define EXT2_XATTR_INDEX_USER                   1
  21#define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS       2
  22#define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  23#define EXT2_XATTR_INDEX_TRUSTED                4
  24#define EXT2_XATTR_INDEX_LUSTRE                 5
  25#define EXT2_XATTR_INDEX_SECURITY               6
  26
  27struct ext2_xattr_header {
  28        __le32  h_magic;        /* magic number for identification */
  29        __le32  h_refcount;     /* reference count */
  30        __le32  h_blocks;       /* number of disk blocks used */
  31        __le32  h_hash;         /* hash value of all attributes */
  32        __u32   h_reserved[4];  /* zero right now */
  33};
  34
  35struct ext2_xattr_entry {
  36        __u8    e_name_len;     /* length of name */
  37        __u8    e_name_index;   /* attribute name index */
  38        __le16  e_value_offs;   /* offset in disk block of value */
  39        __le32  e_value_block;  /* disk block attribute is stored on (n/i) */
  40        __le32  e_value_size;   /* size of attribute value */
  41        __le32  e_hash;         /* hash value of name and value */
  42        char    e_name[0];      /* attribute name */
  43};
  44
  45#define EXT2_XATTR_PAD_BITS             2
  46#define EXT2_XATTR_PAD          (1<<EXT2_XATTR_PAD_BITS)
  47#define EXT2_XATTR_ROUND                (EXT2_XATTR_PAD-1)
  48#define EXT2_XATTR_LEN(name_len) \
  49        (((name_len) + EXT2_XATTR_ROUND + \
  50        sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
  51#define EXT2_XATTR_NEXT(entry) \
  52        ( (struct ext2_xattr_entry *)( \
  53          (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
  54#define EXT2_XATTR_SIZE(size) \
  55        (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)
  56
  57struct mb_cache;
  58
  59# ifdef CONFIG_EXT2_FS_XATTR
  60
  61extern const struct xattr_handler ext2_xattr_user_handler;
  62extern const struct xattr_handler ext2_xattr_trusted_handler;
  63extern const struct xattr_handler ext2_xattr_security_handler;
  64
  65extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
  66
  67extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
  68extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  69
  70extern void ext2_xattr_delete_inode(struct inode *);
  71
  72extern struct mb_cache *ext2_xattr_create_cache(void);
  73extern void ext2_xattr_destroy_cache(struct mb_cache *cache);
  74
  75extern const struct xattr_handler *ext2_xattr_handlers[];
  76
  77# else  /* CONFIG_EXT2_FS_XATTR */
  78
  79static inline int
  80ext2_xattr_get(struct inode *inode, int name_index,
  81               const char *name, void *buffer, size_t size)
  82{
  83        return -EOPNOTSUPP;
  84}
  85
  86static inline int
  87ext2_xattr_set(struct inode *inode, int name_index, const char *name,
  88               const void *value, size_t size, int flags)
  89{
  90        return -EOPNOTSUPP;
  91}
  92
  93static inline void
  94ext2_xattr_delete_inode(struct inode *inode)
  95{
  96}
  97
  98static inline void ext2_xattr_destroy_cache(struct mb_cache *cache)
  99{
 100}
 101
 102#define ext2_xattr_handlers NULL
 103
 104# endif  /* CONFIG_EXT2_FS_XATTR */
 105
 106#ifdef CONFIG_EXT2_FS_SECURITY
 107extern int ext2_init_security(struct inode *inode, struct inode *dir,
 108                              const struct qstr *qstr);
 109#else
 110static inline int ext2_init_security(struct inode *inode, struct inode *dir,
 111                                     const struct qstr *qstr)
 112{
 113        return 0;
 114}
 115#endif
 116