[dm-devel] [PATCH v3 4/7] multipathd: open client socket early

[Benjamin Marzinski]

On Fri, Nov 02, 2018 at 01:23:59PM +0100, Martin Wilck wrote:
> Open the unix socket in multipathd code and pass the fd to
> uxsock_listen(). This will enable us to make the main thread
> wait for successful socket initialization in a follow-up patch.
> 
 
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>

> Signed-off-by: Martin Wilck <mwilck at suse.com>
> ---
>  multipathd/main.c   | 27 ++++++++++++++++++++++-----
>  multipathd/uxlsnr.c | 14 ++------------
>  multipathd/uxlsnr.h |  5 +++--
>  3 files changed, 27 insertions(+), 19 deletions(-)
> 
> diff --git a/multipathd/main.c b/multipathd/main.c
> index a022bdb5..a91a14c6 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -66,6 +66,7 @@ static int use_watchdog;
>  #include "pgpolicies.h"
>  #include "uevent.h"
>  #include "log.h"
> +#include "uxsock.h"
>  
>  #include "mpath_cmd.h"
>  #include "mpath_persist.h"
> @@ -1496,12 +1497,24 @@ uevqloop (void * ap)
>  static void *
>  uxlsnrloop (void * ap)
>  {
> +	long ux_sock;
> +
> +	pthread_cleanup_push(rcu_unregister, NULL);
> +	rcu_register_thread();
> +
> +	ux_sock = ux_socket_listen(DEFAULT_SOCKET);
> +	if (ux_sock == -1) {
> +		condlog(1, "could not create uxsock: %d", errno);
> +		exit_daemon();
> +		goto out;
> +	}
> +	pthread_cleanup_push(uxsock_cleanup, (void *)ux_sock);
> +
>  	if (cli_init()) {
>  		condlog(1, "Failed to init uxsock listener");
> -		return NULL;
> +		exit_daemon();
> +		goto out_sock;
>  	}
> -	pthread_cleanup_push(rcu_unregister, NULL);
> -	rcu_register_thread();
>  	set_handler_callback(LIST+PATHS, cli_list_paths);
>  	set_handler_callback(LIST+PATHS+FMT, cli_list_paths_fmt);
>  	set_handler_callback(LIST+PATHS+RAW+FMT, cli_list_paths_raw);
> @@ -1556,8 +1569,12 @@ uxlsnrloop (void * ap)
>  	set_handler_callback(UNSETPRKEY+MAP, cli_unsetprkey);
>  
>  	umask(077);
> -	uxsock_listen(&uxsock_trigger, ap);
> -	pthread_cleanup_pop(1);
> +	uxsock_listen(&uxsock_trigger, ux_sock, ap);
> +
> +out_sock:
> +	pthread_cleanup_pop(1); /* uxsock_cleanup */
> +out:
> +	pthread_cleanup_pop(1); /* rcu_unregister */
>  	return NULL;
>  }
>  
> diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c
> index 6f666663..773bc878 100644
> --- a/multipathd/uxlsnr.c
> +++ b/multipathd/uxlsnr.c
> @@ -165,24 +165,15 @@ void uxsock_cleanup(void *arg)
>  /*
>   * entry point
>   */
> -void * uxsock_listen(uxsock_trigger_fn uxsock_trigger, void * trigger_data)
> +void * uxsock_listen(uxsock_trigger_fn uxsock_trigger, long ux_sock,
> +		     void * trigger_data)
>  {
> -	long ux_sock;
>  	int rlen;
>  	char *inbuf;
>  	char *reply;
>  	sigset_t mask;
>  	int old_clients = MIN_POLLS;
>  
> -	ux_sock = ux_socket_listen(DEFAULT_SOCKET);
> -
> -	if (ux_sock == -1) {
> -		condlog(1, "could not create uxsock: %d", errno);
> -		exit_daemon();
> -	}
> -
> -	pthread_cleanup_push(uxsock_cleanup, (void *)ux_sock);
> -
>  	condlog(3, "uxsock: startup listener");
>  	polls = (struct pollfd *)MALLOC((MIN_POLLS + 1) * sizeof(struct pollfd));
>  	if (!polls) {
> @@ -322,6 +313,5 @@ void * uxsock_listen(uxsock_trigger_fn uxsock_trigger, void * trigger_data)
>  		}
>  	}
>  
> -	pthread_cleanup_pop(1);
>  	return NULL;
>  }
> diff --git a/multipathd/uxlsnr.h b/multipathd/uxlsnr.h
> index d51a8f99..18f008d7 100644
> --- a/multipathd/uxlsnr.h
> +++ b/multipathd/uxlsnr.h
> @@ -5,7 +5,8 @@
>  
>  typedef int (uxsock_trigger_fn)(char *, char **, int *, bool, void *);
>  
> -void * uxsock_listen(uxsock_trigger_fn uxsock_trigger,
> -		     void * trigger_data);
> +void uxsock_cleanup(void *arg);
> +void *uxsock_listen(uxsock_trigger_fn uxsock_trigger, long ux_sock,
> +		    void * trigger_data);
>  
>  #endif
> -- 
> 2.19.1