[CRIU] [PATCH v2 14/28] files: Kill fd_open_state::receive_fd stage

[Pavel Emelyanov]

On 11/30/2016 07:31 PM, Kirill Tkhai wrote:
> Since "receive" stage is used only for slave fds
> and nobody depends on slave fds receiving is finished,
> we may move it functionality in "post_open" stage.
> This just makes slave fds to be received a little bit later.

This requires clarification.

Consider we have files A and B in current.

Before the patch the opening of them looked like

A->open
B->open
A->recv
B->recv
A->post_open
B->post_open

now it is like

A->open
B->open
A->recv
A->post_open
B->recv
B->post_open

Where did we remove the dependency between A->post_open and B->recv ?

-- Pavel

> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
> ---
>  criu/files.c |   22 +++++++++-------------
>  1 file changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/criu/files.c b/criu/files.c
> index 8a07da6..23ff3f9 100644
> --- a/criu/files.c
> +++ b/criu/files.c
> @@ -865,7 +865,6 @@ static int post_open_fd(int pid, struct fdinfo_list_entry *fle);
>  
>  static struct fd_open_state states[] = {
>  	{ "create",		open_fd,	},
> -	{ "receive",		receive_fd,	},
>  	{ "post_create",	post_open_fd,	},
>  };
>  
> @@ -971,15 +970,17 @@ static int post_open_fd(int pid, struct fdinfo_list_entry *fle)
>  {
>  	struct file_desc *d = fle->desc;
>  
> -	if (!d->ops->post_open)
> -		return 0;
> -
> -	if (is_service_fd(fle->fe->fd, CTL_TTY_OFF))
> -		return d->ops->post_open(d, fle->fe->fd);
> +	if (fle != file_master(d)) {
> +		if (receive_fd(pid, fle) < 0) {
> +			pr_err("Can't receive\n");
> +			return -1;
> +		}
> +		if (!is_service_fd(fle->fe->fd, CTL_TTY_OFF))
> +			return 0;
> +	}
>  
> -	if (fle != file_master(d))
> +	if (!d->ops->post_open)
>  		return 0;
> -
>  	return d->ops->post_open(d, fle->fe->fd);
>  }
>  
> @@ -1034,11 +1035,6 @@ static int open_fd(int pid, struct fdinfo_list_entry *fle)
>  static int receive_fd(int pid, struct fdinfo_list_entry *fle)
>  {
>  	int fd;
> -	struct fdinfo_list_entry *flem;
> -
> -	flem = file_master(fle->desc);
> -	if (flem->pid == pid)
> -		return 0;
>  
>  	pr_info("\tReceive fd for %d\n", fle->fe->fd);
>  
> 
> .
>