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(const struct xattr_handler *handler,
  16                      struct dentry *dentry, char *list, size_t list_size,
  17                      const char *name, size_t name_len)
  18 {
  19         const size_t prefix_len = XATTR_USER_PREFIX_LEN;
  20         const size_t total_len = prefix_len + name_len + 1;
  21
  22         if (!test_opt(dentry->d_sb, XATTR_USER))
  23                 return 0;
  24
  25         if (list && total_len <= list_size) {
  26                 memcpy(list, XATTR_USER_PREFIX, prefix_len);
  27                 memcpy(list+prefix_len, name, name_len);
  28                 list[prefix_len + name_len] = '\0';
  29         }
  30         return total_len;
  31 }
  32
  33 static int
  34 ext4_xattr_user_get(const struct xattr_handler *handler,
  35                     struct dentry *dentry, const char *name,
  36                     void *buffer, size_t size)
  37 {
  38         if (strcmp(name, "") == 0)
  39                 return -EINVAL;
  40         if (!test_opt(dentry->d_sb, XATTR_USER))
  41                 return -EOPNOTSUPP;
  42         return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_USER,
  43                               name, buffer, size);
  44 }
  45
  46 static int
  47 ext4_xattr_user_set(const struct xattr_handler *handler,
  48                     struct dentry *dentry, const char *name,
  49                     const void *value, size_t size, int flags)
  50 {
  51         if (strcmp(name, "") == 0)
  52                 return -EINVAL;
  53         if (!test_opt(dentry->d_sb, XATTR_USER))
  54                 return -EOPNOTSUPP;
  55         return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_USER,
  56                               name, value, size, flags);
  57 }
  58
  59 const struct xattr_handler ext4_xattr_user_handler = {
  60         .prefix = XATTR_USER_PREFIX,
  61         .list   = ext4_xattr_user_list,
  62         .get    = ext4_xattr_user_get,
  63         .set    = ext4_xattr_user_set,
  64 };