dirent.h: Add missing field d_ino

[no1wudi]

Summary

Currently implementations of dirent.h do not have a field for the inode number, but it is required by POSIX.

For better compatibility with POSIX based applications, it is should be added even if it is not actually implemented.

PR coupled with nuttx-apps PR apache/nuttx-apps#2593.

Impact

• include/dirent.h.
• include/nuttx/fs/hostfs.h.
• Makes implementation compatible with POSIX.

Testing

CI and local machine

[yamt]

if we add the field, i guess we should set a sane value.
at least it should be consistent with st_ino.

[no1wudi]

if we add the field, i guess we should set a sane value. at least it should be consistent with st_ino.

I'm not familiar with implementations of VFS, did you mean something like this?

static ssize_t dir_read(FAR struct file *filep, FAR char *buffer,
                        size_t buflen)
{
  FAR struct fs_dirent_s *dir = filep->f_priv;
#ifndef CONFIG_DISABLE_MOUNTPOINT
  FAR struct inode *inode = dir->fd_root;
#endif
  FAR struct dirent *dirent = (FAR struct dirent *)buffer;
  int ret;

  /* Verify that we were provided with a valid directory structure */

  if (buffer == NULL || buflen < sizeof(struct dirent))
    {
      return -EINVAL;
    }

  /* The way we handle the readdir depends on the type of inode
   * that we are dealing with.
   */

#ifndef CONFIG_DISABLE_MOUNTPOINT
  if (INODE_IS_MOUNTPT(inode))
    {
      ret = inode->u.i_mops->readdir(inode, dir, dirent);
    }
  else
#endif
    {
      /* The node is part of the root pseudo file system */

      ret = read_pseudodir(dir, dirent);
    }

  /* ret < 0 is an error. Special case: ret = -ENOENT is end of file */

  if (ret < 0)
    {
      if (ret == -ENOENT)
        {
          ret = 0;
        }

      return ret;
    }

  >>> New added  here <<<

  dirent->d_ino = dir->fd_root->i_ino;


  filep->f_pos++;
  return sizeof(struct dirent);
}