[PATCH 3/3] discover: Add disable param for dm-snapshots

[Samuel Mendoza-Jonas]

Add a debug-style nvram parameter to disallow the use of device-mapper
snapshots.

Signed-off-by: Samuel Mendoza-Jonas <sam.mj at au1.ibm.com>
---
 discover/devmapper.c        | 4 ++++
 discover/platform-powerpc.c | 5 +++++
 discover/platform.c         | 4 ++++
 lib/types/types.h           | 1 +
 utils/pb-config.c           | 2 ++
 5 files changed, 16 insertions(+)

diff --git a/discover/devmapper.c b/discover/devmapper.c
index 1fd1215..e2ef0b5 100644
--- a/discover/devmapper.c
+++ b/discover/devmapper.c
@@ -6,6 +6,7 @@
 
 #include "libdevmapper.h"
 #include "devmapper.h"
+#include "platform.h"
 
 #define MERGE_INTERVAL_US	200000
 
@@ -320,6 +321,9 @@ int devmapper_init_snapshot(struct device_handler *handler,
 {
 	struct ramdisk_device *ramdisk;
 
+	if (config_get()->disable_snapshots)
+		return 0;
+
 	ramdisk = device_handler_get_ramdisk(handler);
 	if (!ramdisk) {
 		pb_log("No ramdisk available for snapshot %s\n",
diff --git a/discover/platform-powerpc.c b/discover/platform-powerpc.c
index fc96305..d45cced 100644
--- a/discover/platform-powerpc.c
+++ b/discover/platform-powerpc.c
@@ -54,6 +54,7 @@ static const char *known_params[] = {
 	"petitboot,language",
 	"petitboot,debug?",
 	"petitboot,write?",
+	"petitboot,snapshots?",
 	NULL,
 };
 
@@ -553,6 +554,10 @@ static void populate_config(struct platform_powerpc *platform,
 	val = get_param(platform, "petitboot,write?");
 	if (val)
 		config->allow_writes = !strcmp(val, "true");
+
+	val = get_param(platform, "petitboot,snapshots?");
+	if (val)
+		config->disable_snapshots = !strcmp(val, "false");
 }
 
 static char *iface_config_str(void *ctx, struct interface_config *config)
diff --git a/discover/platform.c b/discover/platform.c
index b1d0f19..a6bd74c 100644
--- a/discover/platform.c
+++ b/discover/platform.c
@@ -35,6 +35,9 @@ static void dump_config(struct config *config)
 	if (config->safe_mode)
 		pb_log(" safe mode: active\n");
 
+	if (config->disable_snapshots)
+		pb_log(" dm-snapshots disabled\n");
+
 	for (i = 0; i < config->network.n_interfaces; i++) {
 		struct interface_config *ifconf =
 			config->network.interfaces[i];
@@ -109,6 +112,7 @@ void config_set_defaults(struct config *config)
 	config->safe_mode = false;
 	config->lang = NULL;
 	config->allow_writes = true;
+	config->disable_snapshots = false;
 
 	config->n_autoboot_opts = 2;
 	config->autoboot_opts = talloc_array(config, struct autoboot_option,
diff --git a/lib/types/types.h b/lib/types/types.h
index f7e4752..0415206 100644
--- a/lib/types/types.h
+++ b/lib/types/types.h
@@ -151,6 +151,7 @@ struct config {
 	char			*lang;
 
 	/* not user-settable */
+	bool			disable_snapshots;
 	bool			safe_mode;
 	bool			debug;
 };
diff --git a/utils/pb-config.c b/utils/pb-config.c
index 009bec7..c52180b 100644
--- a/utils/pb-config.c
+++ b/utils/pb-config.c
@@ -79,6 +79,8 @@ static void print_config(void *ctx, struct config *config, const char *var)
 			config->safe_mode ? "enabled" : "disabled");
 	print_one_config(ctx, var, "debug", "%s",
 			config->debug ? "enabled" : "disabled");
+	print_one_config(ctx, var, "dm-snapshots", "%s",
+			config->disable_snapshots ? "disabled" : "enabled");
 }
 
 int main(int argc, char **argv)
-- 
2.5.0