[Devel] [PATCH 1/7] spfs: introduce request_spfs_mngr_sock)() helper

[Andrei Vagin]

On Wed, Dec 20, 2017 at 07:06:51PM +0300, Stanislav Kinsburskiy wrote:
> This generic helper will be responsible for both SPFS manager start via
> usernsd and socket request.
> 
> Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com>
> ---
>  criu/spfs.c |   45 ++++++++++++++++++++++++++-------------------
>  1 file changed, 26 insertions(+), 19 deletions(-)
> 
> diff --git a/criu/spfs.c b/criu/spfs.c
> index a5f6031..fff7b9f 100644
> --- a/criu/spfs.c
> +++ b/criu/spfs.c
> @@ -153,16 +153,38 @@ static int start_spfs_manager(void)
>  	return sock;
>  }
>  
> -static int get_spfs_mngr_sock(void *arg, int fd, pid_t pid)
> +static int get_spfs_mngr_sock(void *start, int fd, pid_t pid)
>  {
>  	int sock;
>  
>  	sock = get_service_fd(SPFS_MNGR_SK);
> -	if (sock < 0)
> +	if (sock < 0 && start)

What does this start mean? You don't use its value.

>  		sock = start_spfs_manager();
>  	return sock;
>  }
>  
> +static int request_spfs_mngr_sock(bool *start_mngr)
> +{
> +	int ns_fd;
> +	int sock;
> +
> +	ns_fd = open_proc(PROC_SELF, "ns");
> +	if (ns_fd < 0)
> +		return ns_fd;

Why do you need this ns fd? ^^^
> +
> +	sock = userns_call(get_spfs_mngr_sock, UNS_FDOUT, start_mngr, 0, ns_fd);
> +
> +	close(ns_fd);
> +	return sock;
> +}
> +
> +static int start_spfs_mngr(void)
> +{
> +	bool start;

^^^^^^^^^ ????

> +
> +	return request_spfs_mngr_sock(&start);
> +}
> +
>  static int spfs_request_mount(int sock, struct mount_info *mi, const char *source,
>  			      const char *type, unsigned long mountflags)
>  {
> @@ -268,15 +290,9 @@ int spfs_mount(struct mount_info *mi, const char *source,
>  	       const char *filesystemtype, unsigned long mountflags)
>  {
>  	int ret;
> -	int ns_fd;
>  	int sock;
>  
> -	ns_fd = open_proc(PROC_SELF, "ns");
> -	if (ns_fd < 0)
> -		return ns_fd;
> -
> -	sock = userns_call(get_spfs_mngr_sock, UNS_FDOUT, NULL, 0, ns_fd);
> -	close(ns_fd);
> +	sock = start_spfs_mngr();
>  	if (sock < 0) {
>  		pr_err("failed to mount NFS to path %s\n", mi->mountpoint);
>  		return sock;
> @@ -345,16 +361,7 @@ int spfs_mngr_status(bool *active)
>  
>  int spfs_mngr_sock(void)
>  {
> -	int ns_fd, fd;
> -
> -	ns_fd = open_proc(PROC_SELF, "ns");
> -	if (ns_fd < 0)
> -		return ns_fd;
> -
> -	fd = userns_call(spfs_service_fd, UNS_FDOUT, NULL, 0, ns_fd);
> -
> -	close(ns_fd);
> -	return fd;
> +	return request_spfs_mngr_sock(NULL);
>  }
>  
>  int spfs_set_mode(int sock, const char *mode)
>