fabrics: print an error for ENOENT too

Many nvme commands such as discover, connect, connect-all, etc.
simply return to the prompt without printing any useful error
message when the respective nvme driver modules are not loaded in
the kernel. This is because nothing gets printed when
nvme_scan_topology() returns an ENOENT due to missing nvme system
files stemming from not loading the appropriate nvme modules.
Fix the same. Please note, we want to suppress this ENOENT error
for disconnect-all, hence this change doesn't apply to
disconnect-all here. And while we are it, ensure a zero is returned
if the errno is a ENOENT in this case.

Signed-off-by: Martin George <[email protected]>

fabrics.c

@@ -738,9 +738,8 @@ int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
 	nvme_root_skip_namespaces(r);
 	ret = nvme_scan_topology(r, NULL, NULL);
 	if (ret < 0) {
-		if (errno != ENOENT)
-			fprintf(stderr, "Failed to scan topology: %s\n",
-				nvme_strerror(errno));
+		fprintf(stderr, "Failed to scan topology: %s\n",
+			nvme_strerror(errno));
 		return ret;
 	}
 
@@ -958,9 +957,8 @@ int nvmf_connect(const char *desc, int argc, char **argv)
 	nvme_root_skip_namespaces(r);
 	ret = nvme_scan_topology(r, NULL, NULL);
 	if (ret < 0) {
-		if (errno != ENOENT)
-			fprintf(stderr, "Failed to scan topology: %s\n",
-				nvme_strerror(errno));
+		fprintf(stderr, "Failed to scan topology: %s\n",
+			nvme_strerror(errno));
 		return ret;
 	}
 
@@ -1107,9 +1105,8 @@ int nvmf_disconnect(const char *desc, int argc, char **argv)
 	nvme_root_skip_namespaces(r);
 	ret = nvme_scan_topology(r, NULL, NULL);
 	if (ret < 0) {
-		if (errno != ENOENT)
-			fprintf(stderr, "Failed to scan topology: %s\n",
-				nvme_strerror(errno));
+		fprintf(stderr, "Failed to scan topology: %s\n",
+			nvme_strerror(errno));
 		nvme_free_tree(r);
 		return ret;
 	}
@@ -1183,7 +1180,10 @@ int nvmf_disconnect_all(const char *desc, int argc, char **argv)
 			fprintf(stderr, "Failed to scan topology: %s\n",
 				nvme_strerror(errno));
 		nvme_free_tree(r);
-		return ret;
+		if (errno != ENOENT)
+			return ret;
+		else
+			return 0;
 	}
 
 	nvme_for_each_host(r, h) {
@@ -1255,9 +1255,8 @@ int nvmf_config(const char *desc, int argc, char **argv)
 		nvme_root_skip_namespaces(r);
 		ret = nvme_scan_topology(r, NULL, NULL);
 		if (ret < 0) {
-			if (errno != ENOENT)
-				fprintf(stderr, "Failed to scan topology: %s\n",
-					nvme_strerror(errno));
+			fprintf(stderr, "Failed to scan topology: %s\n",
+				nvme_strerror(errno));
 			nvme_free_tree(r);
 			return ret;
 		}
@@ -1409,9 +1408,8 @@ int nvmf_dim(const char *desc, int argc, char **argv)
 	nvme_root_skip_namespaces(r);
 	ret = nvme_scan_topology(r, NULL, NULL);
 	if (ret < 0) {
-		if (errno != ENOENT)
-			fprintf(stderr, "Failed to scan topology: %s\n",
-				nvme_strerror(errno));
+		fprintf(stderr, "Failed to scan topology: %s\n",
+			nvme_strerror(errno));
 		nvme_free_tree(r);
 		return ret;
 	}

nvme.c

@@ -3331,8 +3331,7 @@ static int list_subsys(int argc, char **argv, struct command *cmd,
 
 	err = nvme_scan_topology(r, filter, (void *)devname);
 	if (err) {
-		if (errno != ENOENT)
-			nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
+		nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
 		return -errno;
 	}
 
@@ -3370,8 +3369,7 @@ static int list(int argc, char **argv, struct command *cmd, struct plugin *plugi
 	}
 	err = nvme_scan_topology(r, NULL, NULL);
 	if (err < 0) {
-		if (errno != ENOENT)
-			nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
+		nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
 		return err;
 	}
 
@@ -9588,8 +9586,7 @@ static int show_topology_cmd(int argc, char **argv, struct command *command, str
 
 	err = nvme_scan_topology(r, NULL, NULL);
 	if (err < 0) {
-		if (errno != ENOENT)
-			nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
+		nvme_show_error("Failed to scan topology: %s", nvme_strerror(errno));
 		nvme_free_tree(r);
 		return err;
 	}