[dm-devel] [PATCH v4 10/12] multipathd: exec multipathc in interactive mode

[Benjamin Marzinski]

On Tue, Aug 30, 2022 at 09:27:11PM +0200, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
> 
> A previous patch disabled interactive mode in multipathd, because
> uxclnt() would return immediately without an input command.
> 
> With this patch, we reinstate interactive mode for "multipath -k",
> by just exec()ing the multipathc client.
> 
> Signed-off-by: Martin Wilck <mwilck at suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  multipathd/Makefile     |  3 ++-
>  multipathd/main.c       | 15 +++++++++++++--
>  multipathd/multipathc.c | 25 +++++++++++++++++++++----
>  3 files changed, 36 insertions(+), 7 deletions(-)
> 
> diff --git a/multipathd/Makefile b/multipathd/Makefile
> index 19ab2e9..8a56304 100644
> --- a/multipathd/Makefile
> +++ b/multipathd/Makefile
> @@ -17,7 +17,8 @@ endif
>  
>  CPPFLAGS += -I$(multipathdir) -I$(mpathutildir) -I$(mpathpersistdir) -I$(mpathcmddir) -I$(thirdpartydir) \
>  	$(shell $(PKGCONFIG) --modversion liburcu 2>/dev/null | \
> -		awk -F. '{ printf("-DURCU_VERSION=0x%06x", 256 * ( 256 * $$1 + $$2) + $$3); }')
> +		awk -F. '{ printf("-DURCU_VERSION=0x%06x", 256 * ( 256 * $$1 + $$2) + $$3); }') \
> +	-DBINDIR='"$(bindir)"'
>  CFLAGS += $(BIN_CFLAGS)
>  LDFLAGS += $(BIN_LDFLAGS)
>  
> diff --git a/multipathd/main.c b/multipathd/main.c
> index 5a40894..66177cd 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -3616,7 +3616,7 @@ main (int argc, char *argv[])
>  	extern char *optarg;
>  	extern int optind;
>  	int arg;
> -	int err;
> +	int err = 0;
>  	int foreground = 0;
>  	struct config *conf;
>  	char *opt_k_arg = NULL;
> @@ -3710,7 +3710,18 @@ main (int argc, char *argv[])
>  			}
>  			c += snprintf(c, s + CMDSIZE - c, "\n");
>  		}
> -		err = uxclnt(s, uxsock_timeout + 100);
> +		if (!s) {
> +			char tmo_buf[16];
> +
> +			snprintf(tmo_buf, sizeof(tmo_buf), "%d",
> +				 uxsock_timeout + 100);
> +			if (execl(BINDIR "/multipathc", "multipathc",
> +				  tmo_buf, NULL) == -1) {
> +				condlog(0, "ERROR: failed to execute multipathc: %m");
> +				err = 1;
> +			}
> +		} else
> +			err = uxclnt(s, uxsock_timeout + 100);
>  		free_config(conf);
>  		return err;
>  	}
> diff --git a/multipathd/multipathc.c b/multipathd/multipathc.c
> index a4f9023..9d49655 100644
> --- a/multipathd/multipathc.c
> +++ b/multipathd/multipathc.c
> @@ -246,14 +246,31 @@ static void process(int fd, unsigned int timeout)
>  	}
>  }
>  
> -int main (void)
> +int main (int argc, const char * const argv[])
>  {
> -	int fd = mpath_connect();
> +	int fd;
> +	int tmo = DEFAULT_REPLY_TIMEOUT + 100;
> +	char *ep;
>  
> -	if (fd == -1)
> +	if (argc > 2) {
> +		fprintf(stderr, "Usage: %s [timeout]\n", argv[0]);
>  		return 1;
> +	}
> +	if (argc == 2) {
> +		tmo = strtol(argv[1], &ep, 10);
> +		if (*argv[1] == '\0' || *ep != '\0' || tmo < 0) {
> +			fprintf(stderr, "ERROR: invalid timeout value\n");
> +			return 1;
> +		}
> +	}
>  
> -	process(fd, DEFAULT_REPLY_TIMEOUT + 100);
> +	fd = mpath_connect();
> +	if (fd == -1) {
> +		fprintf(stderr, "ERROR: failed to connect to multipathd\n");
> +		return 1;
> +	}
> +
> +	process(fd, tmo);
>  	mpath_disconnect(fd);
>  	return 0;
>  }
> -- 
> 2.37.1