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(const struct xattr_handler *handler,
  15                      struct dentry *dentry, char *list, size_t list_size,
  16                      const char *name, size_t name_len)
  17 {
  18         const size_t prefix_len = XATTR_USER_PREFIX_LEN;
  19         const size_t total_len = prefix_len + name_len + 1;
  20
  21         if (!test_opt(dentry->d_sb, XATTR_USER))
  22                 return 0;
  23
  24         if (list && total_len <= list_size) {
  25                 memcpy(list, XATTR_USER_PREFIX, prefix_len);
  26                 memcpy(list+prefix_len, name, name_len);
  27                 list[prefix_len + name_len] = '\0';
  28         }
  29         return total_len;
  30 }
  31
  32 static int
  33 ext2_xattr_user_get(const struct xattr_handler *handler,
  34                     struct dentry *dentry, const char *name,
  35                     void *buffer, size_t size)
  36 {
  37         if (strcmp(name, "") == 0)
  38                 return -EINVAL;
  39         if (!test_opt(dentry->d_sb, XATTR_USER))
  40                 return -EOPNOTSUPP;
  41         return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_USER,
  42                               name, buffer, size);
  43 }
  44
  45 static int
  46 ext2_xattr_user_set(const struct xattr_handler *handler,
  47                     struct dentry *dentry, 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(dentry->d_sb, XATTR_USER))
  53                 return -EOPNOTSUPP;
  54
  55         return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_USER,
  56                               name, value, size, flags);
  57 }
  58
  59 const struct xattr_handler ext2_xattr_user_handler = {
  60         .prefix = XATTR_USER_PREFIX,
  61         .list   = ext2_xattr_user_list,
  62         .get    = ext2_xattr_user_get,
  63         .set    = ext2_xattr_user_set,
  64 };