[dm-devel] [PATCH 5/6] multipath.conf: add all_devs device option

[Benjamin Marzinski]

Sometimes users want to to be able to set a configuration value for all
their devices (for instance, they may want all devices to set no_path_retry
to fail). The builtin device configurations make this tricky, since
they need to change each one device configuration individually.  To avoid
that, this patch adds a new device config option, "all_devs". When this is
set to "yes", the options set in this devices section will override those
values in all the builtin configs.

For instance, to make all builtin configs set no_path_retry to fail, you
could add:

devices {
	device {
		all_devs yes
		no_path_retry fail
	}
}


Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
 libmultipath/config.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++
 libmultipath/config.h |  1 +
 libmultipath/dict.c   | 38 +++++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+)

diff --git a/libmultipath/config.c b/libmultipath/config.c
index 39963b4..d326765 100644
--- a/libmultipath/config.c
+++ b/libmultipath/config.c
@@ -112,6 +112,8 @@ find_hwe (vector hwtable, char * vendor, char * product, char * revision)
 	 * continuing to the generic entries
 	 */
 	vector_foreach_slot_backwards (hwtable, tmp, i) {
+		if (tmp->all_devs == 1)
+			continue;
 		if (hwe_regmatch(tmp, &hwe))
 			continue;
 		ret = tmp;
@@ -353,6 +355,59 @@ merge_hwe (struct hwentry * dst, struct hwentry * src)
 	return 0;
 }
 
+#define overwrite_str(s) \
+do { \
+	if (src->s) { \
+		if (dst->s) \
+			FREE(dst->s); \
+		if (!(dst->s = set_param_str(src->s))) \
+			return 1; \
+	} \
+} while(0)
+
+#define overwrite_num(s) \
+do { \
+	if (src->s) \
+		dst->s = src->s; \
+} while(0)
+
+static int
+overwrite_hwe (struct hwentry * dst, struct hwentry * src)
+{
+	/* don't overwrite vendor, product, revision or all_devs */
+	overwrite_str(uid_attribute);
+	overwrite_str(features);
+	overwrite_str(hwhandler);
+	overwrite_str(selector);
+	overwrite_str(checker_name);
+	overwrite_str(prio_name);
+	overwrite_str(prio_args);
+	overwrite_str(alias_prefix);
+	overwrite_str(bl_product);
+	overwrite_num(pgpolicy);
+	overwrite_num(pgfailback);
+	overwrite_num(rr_weight);
+	overwrite_num(no_path_retry);
+	overwrite_num(minio);
+	overwrite_num(minio_rq);
+	overwrite_num(flush_on_last_del);
+	overwrite_num(fast_io_fail);
+	overwrite_num(dev_loss);
+	overwrite_num(user_friendly_names);
+	overwrite_num(retain_hwhandler);
+	overwrite_num(detect_prio);
+
+	/*
+	 * Make sure features is consistent with
+	 * no_path_retry
+	 */
+	if (dst->no_path_retry == NO_PATH_RETRY_FAIL)
+		remove_feature(&dst->features, "queue_if_no_path");
+	else if (dst->no_path_retry != NO_PATH_RETRY_UNDEF)
+		add_feature(&dst->features, "queue_if_no_path");
+	return 0;
+}
+
 int
 store_hwe (vector hwtable, struct hwentry * dhwe)
 {
@@ -438,6 +493,10 @@ restart:
 			break;
 		j = n;
 		vector_foreach_slot_after(hw, hwe2, j) {
+			if (hwe2->all_devs == 1) {
+				overwrite_hwe(hwe1, hwe2);
+				continue;
+			}
 			if (hwe_regmatch(hwe1, hwe2))
 				continue;
 			/* dup */
diff --git a/libmultipath/config.h b/libmultipath/config.h
index 844ee12..2097879 100644
--- a/libmultipath/config.h
+++ b/libmultipath/config.h
@@ -47,6 +47,7 @@ struct hwentry {
 	char * prio_args;
 	char * alias_prefix;
 
+	int all_devs;
 	int pgpolicy;
 	int pgfailback;
 	int rr_weight;
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index 7de7a67..5b4fbe6 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -918,6 +918,32 @@ device_handler(vector strvec)
 }
 
 static int
+all_devs_handler(vector strvec)
+{
+	char * buff;
+	struct hwentry *hwe = VECTOR_LAST_SLOT(conf->hwtable);
+
+	if (!hwe)
+		return 1;
+
+	buff = set_value(strvec);
+	if (!buff)
+		return 1;
+
+	if ((strlen(buff) == 2 && !strcmp(buff, "no")) ||
+	    (strlen(buff) == 1 && !strcmp(buff, "0")))
+		hwe->all_devs = 0;
+	else if ((strlen(buff) == 3 && !strcmp(buff, "yes")) ||
+		 (strlen(buff) == 1 && !strcmp(buff, "1")))
+		hwe->all_devs = 1;
+	else
+		hwe->all_devs = 0;
+
+	FREE(buff);
+	return 0;
+}
+
+static int
 vendor_handler(vector strvec)
 {
 	struct hwentry * hwe = VECTOR_LAST_SLOT(conf->hwtable);
@@ -2151,6 +2177,17 @@ snprint_hw_dev_loss(char * buff, int len, void * data)
 }
 
 static int
+snprint_hw_all_devs (char *buff, int len, void *data)
+{
+	struct hwentry * hwe = (struct hwentry *)data;
+
+	if (!hwe->all_devs)
+		return 0;
+
+	return snprintf(buff, len, "yes");
+}
+
+static int
 snprint_hw_vendor (char * buff, int len, void * data)
 {
 	struct hwentry * hwe = (struct hwentry *)data;
@@ -2922,6 +2959,7 @@ init_keywords(void)
 	install_keyword_root("devices", &devices_handler);
 	install_keyword_multi("device", &device_handler, NULL);
 	install_sublevel();
+	install_keyword("all_devs", &all_devs_handler, &snprint_hw_all_devs);
 	install_keyword("vendor", &vendor_handler, &snprint_hw_vendor);
 	install_keyword("product", &product_handler, &snprint_hw_product);
 	install_keyword("revision", &revision_handler, &snprint_hw_revision);
-- 
1.8.3.1