fs/ext4/xattr_user.c

   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/string.h>
   9 #include <linux/fs.h>
  10 #include "ext4_jbd2.h"
  11 #include "ext4.h"
  12 #include "xattr.h"
  13
  14 static size_t
  15 ext4_xattr_user_list(struct dentry *dentry, char *list, size_t list_size,
  16                      const char *name, size_t name_len, int type)
  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 ext4_xattr_user_get(struct dentry *dentry, const char *name,
  34                     void *buffer, size_t size, int type)
  35 {
  36         if (strcmp(name, "") == 0)
  37                 return -EINVAL;
  38         if (!test_opt(dentry->d_sb, XATTR_USER))
  39                 return -EOPNOTSUPP;
  40         return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_USER,
  41                               name, buffer, size);
  42 }
  43
  44 static int
  45 ext4_xattr_user_set(struct dentry *dentry, const char *name,
  46                     const void *value, size_t size, int flags, int type)
  47 {
  48         if (strcmp(name, "") == 0)
  49                 return -EINVAL;
  50         if (!test_opt(dentry->d_sb, XATTR_USER))
  51                 return -EOPNOTSUPP;
  52         return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_USER,
  53                               name, value, size, flags);
  54 }
  55
  56 const struct xattr_handler ext4_xattr_user_handler = {
  57         .prefix = XATTR_USER_PREFIX,
  58         .list   = ext4_xattr_user_list,
  59         .get    = ext4_xattr_user_get,
  60         .set    = ext4_xattr_user_set,
  61 };