tree: remove nvme_scan

The problem with this function is that it does several things at once
which prevents fine grained error handling. And almost every user of
this function was not interested in reading a config file.

Thus open code this and handle the ENOENT and EACCES case. For the

Python binding we just ignore any nvme_scan_topology and
nvme_read_config error because this happens inside the global context
constructor

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

Author: igaw

libnvme/examples/discover-loop.c

@@ -50,7 +50,7 @@ static void print_discover_log(struct nvmf_discovery_log *log)
 
 int main()
 {
-	struct nvmf_discovery_log *log = NULL;
+	struct nvmf_discovery_log *log;
 	struct nvme_global_ctx *ctx;
 	nvme_host_t h;
 	nvme_ctrl_t c;
@@ -59,24 +59,30 @@ int main()
 
 	nvmf_default_config(&cfg);
 
-	ret = nvme_scan(NULL, &ctx);
-	if (ret)
-		return ret;
+	ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
+	if (!ctx)
+		return 1;
+
+	ret = nvme_scan_topology(ctx, NULL, NULL);
+	if (ret) {
+		nvme_free_global_ctx(ctx);
+		return 1;
+	}
 	ret = nvme_host_get(ctx, NULL, NULL, &h);
 	if (ret) {
 		fprintf(stderr, "Failed to allocated memory\n");
-		return ret;
+		return 1;
 	}
 	ret = nvme_create_ctrl(ctx, NVME_DISC_SUBSYS_NAME, "loop",
 			       NULL, NULL, NULL, NULL, &c);
 	if (ret) {
 		fprintf(stderr, "Failed to allocate memory\n");
-		return ENOMEM;
+		return 1;
 	}
 	ret = nvmf_add_ctrl(h, c, &cfg);
 	if (ret) {
 		fprintf(stderr, "no controller found\n");
-		return ret;
+		return 1;
 	}
 
 	ret = nvmf_get_discovery_log(c, &log, 4);

libnvme/examples/display-columnar.c

@@ -23,9 +23,17 @@ int main()
 	nvme_ctrl_t c;
 	nvme_path_t p;
 	nvme_ns_t n;
+	int err;
 
-	if (nvme_scan(NULL, &ctx))
-		return -1;
+	ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
+	if (!ctx)
+		return 1;
+
+	err = nvme_scan_topology(ctx, NULL, NULL);
+	if (err) {
+		nvme_free_global_ctx(ctx);
+		return 1;
+	}
 
 	printf("%-16s %-96s %-.16s\n", "Subsystem", "Subsystem-NQN", "Controllers");
 	printf("%-.16s %-.96s %-.16s\n", dash, dash, dash);

libnvme/examples/display-tree.c

@@ -22,9 +22,17 @@ int main()
 	nvme_ctrl_t c, _c;
 	nvme_path_t p, _p;
 	nvme_ns_t n, _n;
+	int err;
 
-	if (nvme_scan(NULL, &ctx))
-		return -1;
+	ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
+	if (!ctx)
+		return 1;
+
+	err = nvme_scan_topology(ctx, NULL, NULL);
+	if (err) {
+		nvme_free_global_ctx(ctx);
+		return 1;
+	}
 
 	printf(".\n");
 	nvme_for_each_host(ctx, h) {

libnvme/examples/telemetry-listen.c

@@ -135,8 +135,14 @@ int main()
 	nvme_ctrl_t c;
 	nvme_host_t h;
 
-	if (nvme_scan(NULL, &ctx))
+	ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
+	if (!ctx)
+		return 1;
+
+	if (nvme_scan_topology(ctx, NULL, NULL)) {
+		nvme_free_global_ctx(ctx);
 		return EXIT_FAILURE;
+	}
 
 	nvme_for_each_host(ctx, h)
 		nvme_for_each_subsystem(h, s)

libnvme/libnvme/nvme.i

@@ -487,8 +487,14 @@ struct nvme_ns {
 %extend nvme_global_ctx {
 	nvme_global_ctx(const char *config_file = NULL) {
 		struct nvme_global_ctx *ctx;
-		if (nvme_scan(config_file, &ctx))
+
+		ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
+		if (!ctx)
 			return NULL;
+
+		nvme_scan_topology(ctx, NULL, NULL);
+		nvme_read_config(ctx, config_file);
+
 		return ctx;
 	}
 	~nvme_global_ctx() {

libnvme/src/libnvme.ld

@@ -208,7 +208,6 @@ LIBNVME_2_0 {
 		nvme_release_fds;
 		nvme_rescan_ctrl;
 		nvme_revoke_tls_key;
-		nvme_scan;
 		nvme_scan_ctrl;
 		nvme_scan_ctrl_namespace_paths;
 		nvme_scan_ctrl_namespaces;

libnvme/src/nvme/tree.c

@@ -345,32 +345,6 @@ int nvme_read_config(struct nvme_global_ctx *ctx, const char *config_file)
 	return err;
 }
 
-int nvme_scan(const char *config_file, struct nvme_global_ctx **ctxp)
-{
-	struct nvme_global_ctx *ctx =
-		nvme_create_global_ctx(NULL, DEFAULT_LOGLEVEL);
-	int ret;
-
-	if (!ctx)
-		return -ENOMEM;
-
-	ret = nvme_scan_topology(ctx, NULL, NULL);
-	if (ret && ret != -ENOENT)
-		goto err;
-	if (config_file) {
-		ret = nvme_read_config(ctx, config_file);
-		if (ret)
-			goto err;
-	}
-
-	*ctxp = ctx;
-	return 0;
-
-err:
-	nvme_free_global_ctx(ctx);
-	return ret;
-}
-
 int nvme_dump_config(struct nvme_global_ctx *ctx, int fd)
 {
 	return json_update_config(ctx, fd);

libnvme/src/nvme/tree.h

@@ -1339,15 +1339,6 @@ void nvme_host_release_fds(struct nvme_host *h);
  */
 void nvme_free_host(nvme_host_t h);
 
-/**
- * nvme_scan() - Scan NVMe topology
- * @config_file:	Configuration file
- * @ctx:		&nvme_global_ctx object to return
- *
- * Return: 0 on success or negative error code otherwise
- */
-int nvme_scan(const char *config_file, struct nvme_global_ctx **ctx);
-
 /**
  * nvme_read_config() - Read NVMe JSON configuration file
  * @ctx:		&struct nvme_global_ctx object

libnvme/test/test.c

@@ -387,14 +387,22 @@ int main(int argc, char **argv)
 	nvme_ctrl_t c;
 	nvme_path_t p;
 	nvme_ns_t n;
+	int err;
 	const char *ctrl = "nvme4";
 	const char *nqn_match = "testnqn";
 
 	printf("Test filter for common loop back target\n");
-	ctx = nvme_create_global_ctx(NULL, DEFAULT_LOGLEVEL);
+	ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
 	if (!ctx)
 		return 1;
-	nvme_scan_topology(ctx, nvme_match_subsysnqn_filter, (void *)nqn_match);
+
+	err = nvme_scan_topology(ctx, nvme_match_subsysnqn_filter,
+		(void *)nqn_match);
+	if (err && !(err == ENOENT || err == EACCES)) {
+		nvme_free_global_ctx(ctx);
+		return 1;
+	}
+
 	nvme_for_each_host(ctx, h) {
 		nvme_for_each_subsystem(h, s) {
 			printf("%s - NQN=%s\n", nvme_subsystem_get_name(s),
@@ -421,10 +429,6 @@ int main(int argc, char **argv)
 		nvme_free_ctrl(c);
 	}
 	printf("\n");
-	nvme_free_global_ctx(ctx);
-
-	if (nvme_scan(NULL, &ctx))
-		return -1;
 
 	printf("Test walking the topology\n");
 	nvme_for_each_host(ctx, h) {

libnvme/test/zns.c

@@ -80,9 +80,17 @@ int main()
 	nvme_host_t h;
 	nvme_ctrl_t c;
 	nvme_ns_t n;
+	int err;
+
+	ctx = nvme_create_global_ctx(stdout, DEFAULT_LOGLEVEL);
+	if (!ctx)
+		return 1;
 
-	if (nvme_scan(NULL, &ctx))
-		return -1;
+	err = nvme_scan_topology(ctx, NULL, NULL);
+	if (err && !(err == -ENOENT || err == -EACCES)) {
+		nvme_free_global_ctx(ctx);
+		return 1;
+	}
 
 	nvme_for_each_host(ctx, h) {
 		nvme_for_each_subsystem(h, s) {