[Libguestfs] [PATCH 2/2] daemon: Change chdir to use openat/fdopendir.

[Jim Meyering]

Richard W.M. Jones wrote:
> Subject: [PATCH 2/2] daemon: Change chdir to use openat/fdopendir.

To make this work on older Linux kernels and on systems
without openat, you can use gnulib's openat module.

...
> +#ifndef _ATFILE_SOURCE
> +#define _ATFILE_SOURCE
> +#endif

In which case, you won't need to do the above.

...
> +  int fd;

I like to call this sort of variable "fd_cwd"
or something similar, so that it's easier to see
that it's more than a "normal" open-on-some-file fd.

Other than that, it looks fine.

> -  /* MUST chdir ("/") before leaving this function. */
> -  if (chdir (sysroot) == -1) {
> +  /* 'fd' here is a surrogate for the current working directory, so
> +   * that we don't have to actually call chdir(2).
> +   */
> +  fd = open (sysroot, O_RDONLY | O_DIRECTORY);
...