[CRIU] [PATCH] scripts: set CRIU_IMAGE_DIR when running scripts

[Pavel Emelyanov]

On 08/12/2014 06:22 PM, Tycho Andersen wrote:
> When doing a restore for LXC, we store some other metadata (which bridge a veth
> was on) in the image directory so that the restore script can correctly unlock
> a network device and attach it to the right interface. This patch is needed so
> that the script can find this metadata.
> 
> Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
> ---
>  util.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/util.c b/util.c
> index a180ea5..4ff8768 100644
> --- a/util.c
> +++ b/util.c
> @@ -460,6 +460,7 @@ int run_scripts(char *action)
>  {
>  	struct script *script;
>  	int ret = 0;
> +	char image_dir[PATH_MAX];

Odd enough, but we have a magic constant PSFDS that says "how much 
would the path to /proc/self/fd/%d occupy on the stack" :)

>  
>  	pr_debug("Running %s scripts\n", action);
>  
> @@ -468,6 +469,12 @@ int run_scripts(char *action)
>  		return -1;
>  	}
>  
> +	sprintf(image_dir, "/proc/%ld/fd/%d", (long) getpid(), get_service_fd(IMG_FD_OFF));

Maybe /proc/self/fd/%d would be nicer? This would allow using the
PSFDS above :)

> +	if (setenv("CRTOOLS_IMAGE_DIR", image_dir, 1)) {
> +		pr_perror("Can't set CRTOOLS_IMAGE_DIR=%s", image_dir);
> +		return -1;
> +	}
> +
>  	list_for_each_entry(script, &opts.scripts, node) {
>  		if (script->path == SCRIPT_RPC_NOTIFY) {
>  			pr_debug("\tRPC\n");
>