LXR linux/fs/ext4/xattr

   1/*
   2 * linux/fs/ext4/xattr_user.c
   3 * Handler for extended user attributes.
   4 *
   5 * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/string.h>
  10#include <linux/fs.h>
  11#include <linux/ext4_jbd2.h>
  12#include <linux/ext4_fs.h>
  13#include "xattr.h"
  14
  15#define XATTR_USER_PREFIX "user."
  16
  17static size_t
  18ext4_xattr_user_list(struct inode *inode, char *list, size_t list_size,
  19                     const char *name, size_t name_len)
  20{
  21        const size_t prefix_len = sizeof(XATTR_USER_PREFIX)-1;
  22        const size_t total_len = prefix_len + name_len + 1;
  23
  24        if (!test_opt(inode->i_sb, XATTR_USER))
  25                return 0;
  26
  27        if (list && total_len <= list_size) {
  28                memcpy(list, XATTR_USER_PREFIX, prefix_len);
  29                memcpy(list+prefix_len, name, name_len);
  30                list[prefix_len + name_len] = '\0';
  31        }
  32        return total_len;
  33}
  34
  35static int
  36ext4_xattr_user_get(struct inode *inode, const char *name,
  37                    void *buffer, size_t size)
  38{
  39        if (strcmp(name, "") == 0)
  40                return -EINVAL;
  41        if (!test_opt(inode->i_sb, XATTR_USER))
  42                return -EOPNOTSUPP;
  43        return ext4_xattr_get(inode, EXT4_XATTR_INDEX_USER, name, buffer, size);
  44}
  45
  46static int
  47ext4_xattr_user_set(struct inode *inode, const char *name,
  48                    const void *value, size_t size, int flags)
  49{
  50        if (strcmp(name, "") == 0)
  51                return -EINVAL;
  52        if (!test_opt(inode->i_sb, XATTR_USER))
  53                return -EOPNOTSUPP;
  54        return ext4_xattr_set(inode, EXT4_XATTR_INDEX_USER, name,
  55                              value, size, flags);
  56}
  57
  58struct xattr_handler ext4_xattr_user_handler = {
  59        .prefix = XATTR_USER_PREFIX,
  60        .list   = ext4_xattr_user_list,
  61        .get    = ext4_xattr_user_get,
  62        .set    = ext4_xattr_user_set,
  63};
  64