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

[Andrei Vagin]

On Mon, Feb 13, 2017 at 04:12:15PM +0300, Pavel Emelyanov wrote:
> 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?

Because nobody uses it on restore. We can add it now or wait when it
will be required. What do you prefer?
> 
> >  
> > @@ -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;
> >  }
> > 
>