From befce7ca99bb54d35a9c8113707e24ec1adba3b6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Mar 2026 12:36:09 +0000
Subject: [PATCH 1/2] Initial plan


From 0da083436f456dfd6c561c24ebc670490caecc84 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Mar 2026 12:44:16 +0000
Subject: [PATCH 2/2] libnvme: fix nvme_scan_topology to handle missing NVMe
 sysfs dirs gracefully

When no NVMe devices are present, /sys/class/nvme and /sys/class/nvme-subsystem
directories may not exist. scandir() returns -1 with errno=ENOENT in this case.
Previously, nvme_scan_topology() treated this as a fatal error, causing nvme_scan()
to fail and the Python global_ctx() constructor to return NULL.

Fix: treat ENOENT from scandir as "no devices found" (0 entries) rather than an
error. Only treat other errno values as actual failures. Also fix error messages
to use strerror(errno) instead of nvme_strerror(-ctrls.num) which was computing
the wrong error code.

This fixes the python-create-ctrl-object and python-sigsegv-during-gc tests
that fail when no NVMe devices are present in the test environment.

Co-authored-by: igaw <1050803+igaw@users.noreply.github.com>
---
 libnvme/src/nvme/tree.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/libnvme/src/nvme/tree.c b/libnvme/src/nvme/tree.c
index 8cdc1321ef..90e64dce48 100644
--- a/libnvme/src/nvme/tree.c
+++ b/libnvme/src/nvme/tree.c
@@ -282,9 +282,14 @@ int nvme_scan_topology(struct nvme_global_ctx *ctx, nvme_scan_filter_t f, void *
 
 	ctrls.num = nvme_scan_ctrls(&ctrls.ents);
 	if (ctrls.num < 0) {
-		nvme_msg(ctx, LOG_DEBUG, "failed to scan ctrls: %s\n",
-			 nvme_strerror(-ctrls.num));
-		return ctrls.num;
+		int err = errno;
+
+		if (err != ENOENT) {
+			nvme_msg(ctx, LOG_DEBUG, "failed to scan ctrls: %s\n",
+				 strerror(err));
+			return -err;
+		}
+		ctrls.num = 0;
 	}
 
 	for (i = 0; i < ctrls.num; i++) {
@@ -300,9 +305,14 @@ int nvme_scan_topology(struct nvme_global_ctx *ctx, nvme_scan_filter_t f, void *
 
 	subsys.num = nvme_scan_subsystems(&subsys.ents);
 	if (subsys.num < 0) {
-		nvme_msg(ctx, LOG_DEBUG, "failed to scan subsystems: %s\n",
-			 nvme_strerror(-subsys.num));
-		return subsys.num;
+		int err = errno;
+
+		if (err != ENOENT) {
+			nvme_msg(ctx, LOG_DEBUG, "failed to scan subsystems: %s\n",
+				 strerror(err));
+			return -err;
+		}
+		subsys.num = 0;
 	}
 
 	for (i = 0; i < subsys.num; i++) {