File 0017-tree-make-nvme_subsystem_scan_namespace-idempotent.patch of Package libnvme.27881

From: Hannes Reinecke <hare@suse.de>
Date: Fri, 10 Jun 2022 10:19:01 +0200
Subject: tree: make nvme_subsystem_scan_namespace() idempotent
Git-commit: 70946ce055892869730f9a19a0f0e73e85fbaa13
References: git-fixes

When issuing a rescan the list of namespaces is not cleared, so
just blindly adding new entries might not yield the expected result.
This patch clears out old entries from the subsystem namespace list
before adding new ones, ensuring that we only ever have one namespace
with a given name in the list of subsystem namespaces.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 src/nvme/tree.c |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

--- a/src/nvme/tree.c
+++ b/src/nvme/tree.c
@@ -1910,7 +1910,7 @@ static void nvme_subsystem_set_ns_path(n
 static int nvme_subsystem_scan_namespace(nvme_root_t r, nvme_subsystem_t s,
 		char *name, nvme_scan_filter_t f, void *f_args)
 {
-	struct nvme_ns *n;
+	struct nvme_ns *n, *_n, *__n;
 
 	nvme_msg(r, LOG_DEBUG, "scan subsystem %s namespace %s\n",
 		 s->name, name);
@@ -1924,6 +1924,19 @@ static int nvme_subsystem_scan_namespace
 		__nvme_free_ns(n);
 		return 0;
 	}
+	nvme_subsystem_for_each_ns_safe(s, _n, __n) {
+		struct nvme_path *p, *_p;
+
+		if (strcmp(n->name, _n->name))
+			continue;
+		/* Detach paths */
+		nvme_namespace_for_each_path_safe(_n, p, _p) {
+			list_del_init(&p->nentry);
+			p->n = NULL;
+		}
+		list_head_init(&_n->paths);
+		__nvme_free_ns(_n);
+	}
 	n->s = s;
 	list_add(&s->namespaces, &n->entry);
 	nvme_subsystem_set_ns_path(s, n);