x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 65 insertions, 0 deletions

diff --git a/fs/ocfs2/cluster/sys.c b/fs/ocfs2/cluster/sys.c
new file mode 100644
index 000000000..022f716c7
--- /dev/null
+++ b/fs/ocfs2/cluster/sys.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sys.c
+ *
+ * OCFS2 cluster sysfs interface
+ *
+ * Copyright (C) 2005 Oracle.  All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/fs.h>
+
+#include "ocfs2_nodemanager.h"
+#include "masklog.h"
+#include "sys.h"
+
+
+static ssize_t version_show(struct kobject *kobj, struct kobj_attribute *attr,
+			    char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%u\n", O2NM_API_VERSION);
+}
+static struct kobj_attribute attr_version =
+	__ATTR(interface_revision, S_IRUGO, version_show, NULL);
+
+static struct attribute *o2cb_attrs[] = {
+	&attr_version.attr,
+	NULL,
+};
+
+static struct attribute_group o2cb_attr_group = {
+	.attrs = o2cb_attrs,
+};
+
+static struct kset *o2cb_kset;
+
+void o2cb_sys_shutdown(void)
+{
+	mlog_sys_shutdown();
+	kset_unregister(o2cb_kset);
+}
+
+int o2cb_sys_init(void)
+{
+	int ret;
+
+	o2cb_kset = kset_create_and_add("o2cb", NULL, fs_kobj);
+	if (!o2cb_kset)
+		return -ENOMEM;
+
+	ret = sysfs_create_group(&o2cb_kset->kobj, &o2cb_attr_group);
+	if (ret)
+		goto error;
+
+	ret = mlog_sys_init(o2cb_kset);
+	if (ret)
+		goto error;
+	return 0;
+error:
+	kset_unregister(o2cb_kset);
+	return ret;
+}