From b4080fb52b70406b1ebb3c0ffa09c836fbf2bd7f Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Tue, 1 Feb 2022 13:49:04 +0100
Subject: [PATCH] Return error from nvme_read_config()

nvme_read_config() can fail, so we should be returning an error code
to inform the caller about it.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 src/nvme/json.c    | 15 ++++++++++-----
 src/nvme/private.h |  2 +-
 src/nvme/tree.c    | 11 ++++++++---
 src/nvme/tree.h    |  4 +++-
 4 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/src/nvme/json.c b/src/nvme/json.c
index ebc1ae4f..c4375d9f 100644
--- a/src/nvme/json.c
+++ b/src/nvme/json.c
@@ -126,7 +126,8 @@ static void json_parse_subsys(nvme_host_t h, struct json_object *subsys_obj)
 		struct json_object *port_obj;
 
 		port_obj = json_object_array_get_idx(port_array, p);
-		json_parse_port(s, port_obj);
+		if (port_obj)
+			json_parse_port(s, port_obj);
 	}
 }
 
@@ -153,11 +154,12 @@ static void json_parse_host(nvme_root_t r, struct json_object *host_obj)
 		return;
 	for (s = 0; s < json_object_array_length(subsys_array); s++) {
 		subsys_obj = json_object_array_get_idx(subsys_array, s);
-		json_parse_subsys(h, subsys_obj);
+		if (subsys_obj)
+			json_parse_subsys(h, subsys_obj);
 	}
 }
 
-void json_read_config(nvme_root_t r, const char *config_file)
+int json_read_config(nvme_root_t r, const char *config_file)
 {
 	struct json_object *json_root, *host_obj;
 	int h;
@@ -166,13 +168,16 @@ void json_read_config(nvme_root_t r, const char *config_file)
 	if (!json_root) {
 		nvme_msg(r, LOG_DEBUG, "Failed to read %s, %s\n",
 			config_file, json_util_get_last_err());
-		return;
+		errno = EAGAIN;
+		return -1;
 	}
 	for (h = 0; h < json_object_array_length(json_root); h++) {
 		host_obj = json_object_array_get_idx(json_root, h);
-		json_parse_host(r, host_obj);
+		if (host_obj)
+			json_parse_host(r, host_obj);
 	}
 	json_object_put(json_root);
+	return 0;
 }
 
 #define JSON_STRING_OPTION(c, p, o)				\
diff --git a/src/nvme/private.h b/src/nvme/private.h
index 945b453a..356cae30 100644
--- a/src/nvme/private.h
+++ b/src/nvme/private.h
@@ -129,7 +129,7 @@ struct nvme_root {
 
 int nvme_set_attr(const char *dir, const char *attr, const char *value);
 
-void json_read_config(nvme_root_t r, const char *config_file);
+int json_read_config(nvme_root_t r, const char *config_file);
 
 int json_update_config(nvme_root_t r, const char *config_file);
 
diff --git a/src/nvme/tree.c b/src/nvme/tree.c
index a2fe5335..0acc045e 100644
--- a/src/nvme/tree.c
+++ b/src/nvme/tree.c
@@ -137,14 +137,19 @@ nvme_root_t nvme_create_root(FILE *fp, int log_level)
 	return r;
 }
 
-void nvme_read_config(nvme_root_t r, const char *config_file)
+int nvme_read_config(nvme_root_t r, const char *config_file)
 {
+	int err = -1;
 #ifdef CONFIG_JSONC
 	if (r && config_file) {
-		json_read_config(r, config_file);
-		r->config_file = strdup(config_file);
+		err = json_read_config(r, config_file);
+		if (!err)
+			r->config_file = strdup(config_file);
 	}
+#else
+	errno = ENOTSUP;
 #endif
+	return err;
 }
 
 nvme_root_t nvme_scan(const char *config_file)
diff --git a/src/nvme/tree.h b/src/nvme/tree.h
index 00b75b00..1f9703fb 100644
--- a/src/nvme/tree.h
+++ b/src/nvme/tree.h
@@ -1040,8 +1040,10 @@ nvme_root_t nvme_scan(const char *config_file);
  *
  * Read in the contents of @config_file and merge them with
  * the elements in @r.
+ *
+ * Returns: 0 on success, -1 on failure with errno set.
  */
-void nvme_read_config(nvme_root_t r, const char *config_file);
+int nvme_read_config(nvme_root_t r, const char *config_file);
 
 /**
  * nvme_refresh_topology() -
-- 
2.50.1