[dm-devel] [PATCH 3/7] libmultipath: clarify option conflicts for "features"

[Martin Wilck]

The "features" option in multipath.conf can possibly conflict
with the "no_path_retry" and "retain_attached_hw_handler" options.

Currently, "no_path_retry" takes precedence, unless it is set to
"fail", in which case it's overridden. No precedence rules are
defined for "retain_attached_hw_handler".

Make this behavior more consistent by always giving precedence
to the explicit config file options, and improve logging.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmultipath/configure.c |  4 ++--
 libmultipath/propsel.c   | 37 ++++++++++++++++++++++++-------------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index bd090d9a..fd4721dd 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -280,11 +280,11 @@ int setup_map(struct multipath *mpp, char *params, int params_size)
 	select_pgfailback(conf, mpp);
 	select_pgpolicy(conf, mpp);
 	select_selector(conf, mpp);
-	select_features(conf, mpp);
 	select_hwhandler(conf, mpp);
+	select_no_path_retry(conf, mpp);
+	select_features(conf, mpp);
 	select_rr_weight(conf, mpp);
 	select_minio(conf, mpp);
-	select_no_path_retry(conf, mpp);
 	select_mode(conf, mpp);
 	select_uid(conf, mpp);
 	select_gid(conf, mpp);
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 99d17e65..4267aa04 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -272,6 +272,9 @@ out:
 int select_features(struct config *conf, struct multipath *mp)
 {
 	char *origin;
+	char buff[12];
+	static const char q_i_n_p[] = "queue_if_no_path";
+	static const char r_a_h_h[] = "retain_attached_hw_handler";
 
 	mp_set_mpe(features);
 	mp_set_ovr(features);
@@ -280,19 +283,30 @@ int select_features(struct config *conf, struct multipath *mp)
 	mp_set_default(features, DEFAULT_FEATURES);
 out:
 	mp->features = STRDUP(mp->features);
-	condlog(3, "%s: features = \"%s\" %s", mp->alias, mp->features, origin);
 
-	if (strstr(mp->features, "queue_if_no_path")) {
-		if (mp->no_path_retry == NO_PATH_RETRY_UNDEF)
+	if (strstr(mp->features, q_i_n_p)) {
+		if (mp->no_path_retry == NO_PATH_RETRY_UNDEF) {
 			mp->no_path_retry = NO_PATH_RETRY_QUEUE;
-		else if (mp->no_path_retry == NO_PATH_RETRY_FAIL) {
-			condlog(1, "%s: config error, overriding 'no_path_retry' value",
-				mp->alias);
-			mp->no_path_retry = NO_PATH_RETRY_QUEUE;
-		} else if (mp->no_path_retry != NO_PATH_RETRY_QUEUE)
-			condlog(1, "%s: config error, ignoring 'queue_if_no_path' because no_path_retry=%d",
-				mp->alias, mp->no_path_retry);
+			print_no_path_retry(buff, sizeof(buff),
+					    &mp->no_path_retry);
+			condlog(3, "%s: no_path_retry = %s (inherited setting from feature '%s')",
+				mp->alias, buff, q_i_n_p);
+		} else {
+			print_no_path_retry(buff, sizeof(buff),
+					    &mp->no_path_retry);
+			condlog(2, "%s: ignoring feature '%s' because no_path_retry is set to '%s'",
+				mp->alias, q_i_n_p, buff);
+			remove_feature(&mp->features, q_i_n_p);
+		};
 	}
+	if (strstr(mp->features, r_a_h_h) &&
+	    mp->retain_hwhandler == RETAIN_HWHANDLER_OFF) {
+		condlog(2, "%s: ignoring feature '%s' because %s is set to 'off'",
+			mp->alias, r_a_h_h, r_a_h_h);
+		remove_feature(&mp->features, r_a_h_h);
+	}
+
+	condlog(3, "%s: features = \"%s\" %s", mp->alias, mp->features, origin);
 	return 0;
 }
 
@@ -469,9 +483,6 @@ out:
 	if (origin)
 		condlog(3, "%s: no_path_retry = %s %s", mp->alias, buff,
 			origin);
-	else if (mp->no_path_retry != NO_PATH_RETRY_UNDEF)
-		condlog(3, "%s: no_path_retry = %s (inherited setting)",
-			mp->alias, buff);
 	else
 		condlog(3, "%s: no_path_retry = undef (setting: multipath internal)",
 			mp->alias);
-- 
2.13.0