nvme: use cleanup helper for nvme_root_t objects

Use a cleanup helper for the nvme_root_t objects which simplifies the
error paths and ensures we are always removing all the allocated
resources.

Signed-off-by: Daniel Wagner <[email protected]>

nvme.c

@@ -3269,7 +3269,7 @@ static bool nvme_match_device_filter(nvme_subsystem_t s,
 static int list_subsys(int argc, char **argv, struct command *cmd,
 		struct plugin *plugin)
 {
-	nvme_root_t r = NULL;
+	_cleanup_nvme_root_ nvme_root_t r = NULL;
 	enum nvme_print_flags flags;
 	const char *desc = "Retrieve information for subsystems";
 	nvme_scan_filter_t filter = NULL;
@@ -3281,7 +3281,7 @@ static int list_subsys(int argc, char **argv, struct command *cmd,
 
 	err = argconfig_parse(argc, argv, desc, opts);
 	if (err < 0)
-		goto ret;
+		return err;
 
 	devname = NULL;
 	if (optind < argc)
@@ -3303,17 +3303,15 @@ static int list_subsys(int argc, char **argv, struct command *cmd,
 			nvme_show_error("Failed to scan nvme subsystem for %s", devname);
 		else
 			nvme_show_error("Failed to scan nvme subsystem");
-		err = -errno;
-		goto ret;
+		return -errno;
 	}
 
 	if (devname) {
 		int subsys_num;
 
 		if (sscanf(devname, "nvme%dn%d", &subsys_num, &nsid) != 2) {
 			nvme_show_error("Invalid device name %s", devname);
-			err = -EINVAL;
-			goto ret;
+			return -EINVAL;
 		}
 		filter = nvme_match_device_filter;
 	}
@@ -3322,22 +3320,19 @@ static int list_subsys(int argc, char **argv, struct command *cmd,
 	if (err) {
 		if (errno != ENOENT)
 			nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
-		goto ret;
+		return -errno;
 	}
 
 	nvme_show_subsystem_list(r, nsid != NVME_NSID_ALL, flags);
 
-ret:
-	if (r)
-		nvme_free_tree(r);
-	return err;
+	return 0;
 }
 
 static int list(int argc, char **argv, struct command *cmd, struct plugin *plugin)
 {
 	const char *desc = "Retrieve basic information for all NVMe namespaces";
 	enum nvme_print_flags flags;
-	nvme_root_t r;
+	_cleanup_nvme_root_ nvme_root_t r = NULL;
 	int err = 0;
 
 	NVME_ARGS(opts);
@@ -3364,12 +3359,10 @@ static int list(int argc, char **argv, struct command *cmd, struct plugin *plugi
 	if (err < 0) {
 		if (errno != ENOENT)
 			nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
-		nvme_free_tree(r);
 		return err;
 	}
 
 	nvme_show_list_items(r, flags);
-	nvme_free_tree(r);
 
 	return err;
 }
@@ -9508,7 +9501,7 @@ static int show_topology_cmd(int argc, char **argv, struct command *command, str
 	const char *desc = "Show the topology\n";
 	const char *ranking = "Ranking order: namespace|ctrl";
 	enum nvme_print_flags flags;
-	nvme_root_t r;
+	_cleanup_nvme_root_ nvme_root_t r = NULL;
 	enum nvme_cli_topo_ranking rank;
 	int err;
 
@@ -9560,7 +9553,6 @@ static int show_topology_cmd(int argc, char **argv, struct command *command, str
 	}
 
 	nvme_show_topology(r, rank, flags);
-	nvme_free_tree(r);
 
 	return err;
 }

util/cleanup.h

@@ -5,6 +5,8 @@
 #include <unistd.h>
 #include <stdlib.h>
 
+#include <libnvme.h>
+
 #include "util/mem.h"
 
 #define __cleanup__(fn) __attribute__((cleanup(fn)))
@@ -34,4 +36,11 @@ static inline void close_file(int *f)
 }
 #define _cleanup_file_ __cleanup__(close_file)
 
+static inline void cleanup_nvme_root(nvme_root_t *r)
+{
+	if (r)
+		nvme_free_tree(*r);
+}
+#define _cleanup_nvme_root_ __cleanup__(cleanup_nvme_root)
+
 #endif