[CRIU] [PATCH 06/10] util: move open_proc_fd to service_fd

[Pavel Emelyanov]

On 02/13/2017 08:49 AM, Andrei Vagin wrote:
> From: Andrei Vagin <avagin at virtuozzo.com>
> 
> We need this to avoid conflicts with file descriptors,
> which has to be restored.
> 
> Currently open_proc_pid() doesn't used during restoring
> file descriptors, but we are going to use it to restore
> sockets in proper network namespaces.
> 
> Signed-off-by: Andrei Vagin <avagin at virtuozzo.com>
> ---
>  criu/include/servicefd.h |  1 +
>  criu/util.c              | 18 +++++++++++-------
>  2 files changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/criu/include/servicefd.h b/criu/include/servicefd.h
> index c070480..c826d37 100644
> --- a/criu/include/servicefd.h
> +++ b/criu/include/servicefd.h
> @@ -9,6 +9,7 @@ enum sfd_type {
>  	LOG_FD_OFF,
>  	IMG_FD_OFF,
>  	PROC_FD_OFF,	/* fd with /proc for all proc_ calls */
> +	PROC_PID_FD_OFF,
>  	CTL_TTY_OFF,
>  	SELF_STDIN_OFF,
>  	CR_PROC_FD_OFF, /* some other's proc fd.
> diff --git a/criu/util.c b/criu/util.c
> index eb74be7..6b98a08 100644
> --- a/criu/util.c
> +++ b/criu/util.c
> @@ -246,7 +246,6 @@ int move_fd_from(int *img_fd, int want_fd)
>   */
>  
>  static pid_t open_proc_pid = PROC_NONE;
> -static int open_proc_fd = -1;
>  static pid_t open_proc_self_pid;
>  static int open_proc_self_fd = -1;

There's also open_proc_self_fd which works in the same manner, why
not moving it to service set?

>  
> @@ -259,13 +258,18 @@ static inline void set_proc_self_fd(int fd)
>  	open_proc_self_pid = getpid();
>  }
>  
> -static inline void set_proc_pid_fd(int pid, int fd)
> +static inline int set_proc_pid_fd(int pid, int fd)
>  {
> -	if (open_proc_fd >= 0)
> -		close(open_proc_fd);
> +	int ret;
> +
> +	if (fd < 0)
> +		return close_service_fd(PROC_PID_FD_OFF);
>  
>  	open_proc_pid = pid;
> -	open_proc_fd = fd;
> +	ret = install_service_fd(PROC_PID_FD_OFF, fd);
> +	close(fd);
> +
> +	return ret;
>  }
>  
>  static inline int get_proc_fd(int pid)
> @@ -277,7 +281,7 @@ static inline int get_proc_fd(int pid)
>  		}
>  		return open_proc_self_fd;
>  	} else if (pid == open_proc_pid)
> -		return open_proc_fd;
> +		return get_service_fd(PROC_PID_FD_OFF);
>  	else
>  		return -1;
>  }
> @@ -361,7 +365,7 @@ inline int open_pid_proc(pid_t pid)
>  	if (pid == PROC_SELF)
>  		set_proc_self_fd(fd);
>  	else
> -		set_proc_pid_fd(pid, fd);
> +		fd = set_proc_pid_fd(pid, fd);
>  
>  	return fd;
>  }
>