fs/ext2/xattr_user.c

   1 /*
   2  * linux/fs/ext2/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/init.h>
   9 #include <linux/string.h>
  10 #include "ext2.h"
  11 #include "xattr.h"
  12
  13 static size_t
  14 ext2_xattr_user_list(struct dentry *dentry, char *list, size_t list_size,
  15                 const char *name, size_t name_len, int type)
  16 {
  17         const size_t prefix_len = XATTR_USER_PREFIX_LEN;
  18         const size_t total_len = prefix_len + name_len + 1;
  19
  20         if (!test_opt(dentry->d_sb, XATTR_USER))
  21                 return 0;
  22
  23         if (list && total_len <= list_size) {
  24                 memcpy(list, XATTR_USER_PREFIX, prefix_len);
  25                 memcpy(list+prefix_len, name, name_len);
  26                 list[prefix_len + name_len] = '\0';
  27         }
  28         return total_len;
  29 }
  30
  31 static int
  32 ext2_xattr_user_get(struct dentry *dentry, const char *name,
  33                 void *buffer, size_t size, int type)
  34 {
  35         if (strcmp(name, "") == 0)
  36                 return -EINVAL;
  37         if (!test_opt(dentry->d_sb, XATTR_USER))
  38                 return -EOPNOTSUPP;
  39         return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_USER,
  40                               name, buffer, size);
  41 }
  42
  43 static int
  44 ext2_xattr_user_set(struct dentry *dentry, const char *name,
  45                 const void *value, size_t size, int flags, int type)
  46 {
  47         if (strcmp(name, "") == 0)
  48                 return -EINVAL;
  49         if (!test_opt(dentry->d_sb, XATTR_USER))
  50                 return -EOPNOTSUPP;
  51
  52         return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_USER,
  53                               name, value, size, flags);
  54 }
  55
  56 const struct xattr_handler ext2_xattr_user_handler = {
  57         .prefix = XATTR_USER_PREFIX,
  58         .list   = ext2_xattr_user_list,
  59         .get    = ext2_xattr_user_get,
  60         .set    = ext2_xattr_user_set,
  61 };