[CRIU] [PATCH] image: do_open_remote_image: Move the unix sockets to workdir

[Pavel Emelyanov]

On 07/17/2017 09:49 PM, Omri Kramer wrote:
> It's better to open the unix sockets for dump and restore
> inside the workdir. See TODO item 1 in:
> https://github.com/xemul/criu/commit/037b2e3c95e098d63a3500834681543da544840e
> 
> Signed-off-by: Omri Kramer <omri.kramer at gmail.com>
> Signed-off-by: Lior Fisch <fischlior at gmail.com>
> ---
>  criu/image.c             | 32 +++++++++++++++++++++++++++++++-
>  criu/include/servicefd.h |  1 +
>  2 files changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/criu/image.c b/criu/image.c
> index 62e8e71..7c21178 100644
> --- a/criu/image.c
> +++ b/criu/image.c
> @@ -338,7 +338,7 @@ int do_open_remote_image(int dfd, char *path, int flags)
>  		return -1;
>  	}
>  
> -	if (fchdir(get_service_fd(IMG_FD_OFF)) < 0) {
> +	if (fchdir(get_service_fd(WRK_FD_OFF)) < 0) {
>  		pr_perror("fchdir to dfd failed!");
>  		close(save);
>  		return -1;
> @@ -465,6 +465,32 @@ struct cr_img *img_from_fd(int fd)
>  	return img;
>  }
>  
> +static void close_work_dir(void)
> +{
> +	close_service_fd(WRK_FD_OFF);
> +}
> +
> +static int open_work_dir(char *dir)
> +{
> +	int fd;
> +
> +	fd = open(dir, O_RDONLY);
> +	if (fd < 0) {
> +		pr_perror("Can't open dir %s", dir);
> +		return -1;
> +	}
> +
> +	if (install_service_fd(WRK_FD_OFF, fd) < 0) {
> +		pr_perror("Can't install work_fd\n");
> +		close(fd);
> +		return -1;
> +	}

Right now all the code in criu assumes, that workdir is cwd. Why do we
need to introduce a service descriptor for that?

> +
> +	close(fd);
> +	
> +	return 0;
> +}
> +
>  int open_image_dir(char *dir)
>  {
>  	int fd, ret;
> @@ -481,6 +507,8 @@ int open_image_dir(char *dir)
>  
>  	if (opts.remote) {
>  		init_snapshot_id(dir);
> +		if (open_work_dir(opts.work_dir) < 0)
> +			goto err;
>  	} else if (opts.img_parent) {
>  		ret = symlinkat(opts.img_parent, fd, CR_PARENT_LINK);
>  		if (ret < 0 && errno != EEXIST) {
> @@ -503,6 +531,8 @@ err:
>  void close_image_dir(void)
>  {
>  	close_service_fd(IMG_FD_OFF);
> +	if(opts.remote)
> +		close_work_dir();
>  }
>  
>  static unsigned long page_ids = 1;
> diff --git a/criu/include/servicefd.h b/criu/include/servicefd.h
> index b779223..66e4aeb 100644
> --- a/criu/include/servicefd.h
> +++ b/criu/include/servicefd.h
> @@ -8,6 +8,7 @@ enum sfd_type {
>  
>  	LOG_FD_OFF,
>  	IMG_FD_OFF,
> +	WRK_FD_OFF,
>  	PROC_FD_OFF,	/* fd with /proc for all proc_ calls */
>  	PROC_PID_FD_OFF,
>  	CTL_TTY_OFF,
>