[dm-devel] [PATCH] libmultipath: fix multipath -q command logic

[Christophe Varoqui]

Hannes, Ben,

are you ok with the solution to these two issues.
Seems sane to me.

Thanks,
Christophe

On Tue, Oct 11, 2016 at 8:46 AM, <tang.junhui at zte.com.cn> wrote:

> Please have a review for this patch, any comment will be highly
> appreciated.
>
>
>
>
> 发件人:         tang.junhui at zte.com.cn
> 收件人:         christophe varoqui <christophe.varoqui at free.fr>,
> 抄送:        dm-devel at redhat.com, zhang.kai16 at zte.com.cn, "tang.junhui" <
> tang.junhui at zte.com.cn>
> 日期:         2016/08/16 19:33
> 主题:        [PATCH] libmultipath: fix multipath -q command logic
> ------------------------------
>
>
>
> From: "tang.junhui" <tang.junhui at zte.com.cn>
>
> multipath judged whether multipathd service in running by check_daemon()
> when executing
> mutipath commands, check_daemon() try to connect to the multipathd service
> and execute
> "show dameon" command. The expected result is that the command will be
> failed when the
> service is not running, however, mpath_connect() will activate the
> multipathd service when
> the service is not running, so check_daemon() always return with true.
> Another problem is that
> multipath command with -q parameter is not processed in coalesce_paths().
> This patch fix for
> those two problems.
>
> Signed-off-by: tang.junhui <tang.junhui at zte.com.cn>
> ---
> libmultipath/configure.c | 85 +++++++++++++++++++++++++++---
> ------------------
> 1 file changed, 48 insertions(+), 37 deletions(-)
>
> diff --git a/libmultipath/configure.c b/libmultipath/configure.c
> index 707e6be..d8a17a6 100644
> --- a/libmultipath/configure.c
> +++ b/libmultipath/configure.c
> @@ -715,36 +715,36 @@ deadmap (struct multipath * mpp)
>                  return 1; /* dead */
> }
>
> -int check_daemon(void)
> +static int
> +check_daemon(void)
> {
>                  int fd;
> -                 char *reply;
> -                 int ret = 0;
> -                 unsigned int timeout;
> -                 struct config *conf;
> -
> -                 fd = mpath_connect();
> -                 if (fd == -1)
> -                                  return 0;
> +                 struct flock lock;
>
> -                 if (send_packet(fd, "show daemon") != 0)
> -                                  goto out;
> -                 conf = get_multipath_config();
> -                 timeout = conf->uxsock_timeout;
> -                 put_multipath_config(conf);
> -                 if (recv_packet(fd, &reply, timeout) != 0)
> -                                  goto out;
> -
> -                 if (strstr(reply, "shutdown"))
> -                                  goto out_free;
> -
> -                 ret = 1;
> +                 fd = open(DEFAULT_PIDFILE, O_RDONLY);
> +                 if (fd < 0) {
> +                                  if (errno == ENOENT)
> +                                                   return 0;
> +                                  if (errno == EMFILE)
> +                                                   condlog(0, "failed to
> open file, increase max_fds at %s", DEFAULT_CONFIGFILE);
> +                                  else
> +                                                   condlog(0, "can not
> open pidfile %s: %s", DEFAULT_PIDFILE, strerror(errno));
> +                                  return -1;
> +                 }
>
> -out_free:
> -                 FREE(reply);
> -out:
> -                 mpath_disconnect(fd);
> -                 return ret;
> +                 lock.l_type = F_WRLCK;
> +                 lock.l_start = 0;
> +                 lock.l_whence = SEEK_SET;
> +                 lock.l_len = 0;
> +                 if (fcntl(fd, F_GETLK, &lock) < 0) {
> +                                  condlog(0, "can not get file locker,
> %s: %s", DEFAULT_PIDFILE, strerror(errno));
> +                                  close(fd);
> +                                  return -1;
> +                 }
> +                 close(fd);
> +                 if (lock.l_type == F_UNLCK)
> +                                  return 0;
> +                 return 1;
> }
>
> extern int
> @@ -873,17 +873,28 @@ coalesce_paths (struct vectors * vecs, vector newmp,
> char * refwwid, int force_r
>                                   if (r == DOMAP_DRY)
>                                                    continue;
>
> -                                  conf = get_multipath_config();
> -                                  allow_queueing = conf->allow_queueing;
> -                                  put_multipath_config(conf);
> -                                  if (!is_daemon && !allow_queueing &&
> !check_daemon()) {
> -                                                   if (mpp->no_path_retry
> != NO_PATH_RETRY_UNDEF &&
> -                                                       mpp->no_path_retry
> != NO_PATH_RETRY_FAIL)
> -
>  condlog(3, "%s: multipathd not running, unset "
> -
>             "queue_if_no_path feature", mpp->alias);
> -                                                   if
> (!dm_queue_if_no_path(mpp->alias, 0))
> -
>  remove_feature(&mpp->features,
> -
>                    "queue_if_no_path");
> +                                  /* run as multipath command and the
> service is not running */
> +                                  if (!is_daemon && !check_daemon()) {
> +                                                   conf =
> get_multipath_config();
> +                                                   allow_queueing =
> conf->allow_queueing;
> +
> put_multipath_config(conf);
> +                                                   /* no -q choice */
> +                                                   if (!allow_queueing) {
> +                                                                    if
> (mpp->no_path_retry != NO_PATH_RETRY_UNDEF &&
> +
>             mpp->no_path_retry != NO_PATH_RETRY_FAIL)
> +
>             condlog(3, "%s: multipathd not running, unset "
> +
>                              "queue_if_no_path feature", mpp->alias);
> +                                                                    if
> (!dm_queue_if_no_path(mpp->alias, 0))
> +
>             remove_feature(&mpp->features,
> +
>                                               "queue_if_no_path");
> +                                                   } else { /* with -q
> choice */
> +                                                                    if
> (mpp->no_path_retry == NO_PATH_RETRY_UNDEF ||
> +
>             mpp->no_path_retry == NO_PATH_RETRY_FAIL)
> +
>             condlog(3, "%s: multipathd not running, set "
> +
>                              "queue_if_no_path feature", mpp->alias);
> +                                                                    if
> (!dm_queue_if_no_path(mpp->alias, 1))
> +
>             add_feature(&mpp->features, "queue_if_no_path");
> +                                                   }
>                                   }
>                                   else if (mpp->no_path_retry !=
> NO_PATH_RETRY_UNDEF) {
>                                                    if (mpp->no_path_retry
> == NO_PATH_RETRY_FAIL) {
> --
> 2.8.1.windows.1
>
>
>
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