From 97a16dc89797d88793801ed81e71b69ee138aeec Mon Sep 17 00:00:00 2001
From: Jeremy Kerr <jk@codeconstruct.com.au>
Date: Tue, 21 Jun 2022 16:47:18 +0800
Subject: [PATCH] mi: free endpoints on root destruction

The root_t object needs to persist through the lifetime of an endpoint,
so close the endpoints on nvme_mi_free_root, and track allocated
endpoints in the root->endpoints list.

To do the destruction safely, we need a _safe variant of the endpoint
iterator macro.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
---
 src/nvme/mi.c |  7 +++++++
 src/nvme/mi.h | 12 ++++++++++++
 test/mi.c     | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/src/nvme/mi.c b/src/nvme/mi.c
index b59cacad..1d3162b3 100644
--- a/src/nvme/mi.c
+++ b/src/nvme/mi.c
@@ -39,6 +39,11 @@ nvme_root_t nvme_mi_create_root(FILE *fp, int log_level)
 
 void nvme_mi_free_root(nvme_root_t root)
 {
+	nvme_mi_ep_t ep, tmp;
+
+	nvme_mi_for_each_endpoint_safe(root, ep, tmp)
+		nvme_mi_close(ep);
+
 	free(root);
 }
 
@@ -50,6 +55,8 @@ struct nvme_mi_ep *nvme_mi_init_ep(nvme_root_t root)
 	list_node_init(&ep->root_entry);
 	ep->root = root;
 
+	list_add(&root->endpoints, &ep->root_entry);
+
 	return ep;
 }
 
diff --git a/src/nvme/mi.h b/src/nvme/mi.h
index 57087157..58f3267e 100644
--- a/src/nvme/mi.h
+++ b/src/nvme/mi.h
@@ -317,6 +317,18 @@ nvme_mi_ep_t nvme_mi_next_endpoint(nvme_root_t m, nvme_mi_ep_t e);
 	for (e = nvme_mi_first_endpoint(m); e != NULL;	\
 	     e = nvme_mi_next_endpoint(m, e))
 
+/**
+ * nvme_mi_for_each_endpoint_safe - Iterator for NVMe-MI endpoints, allowing
+ * deletion during traversal
+ * @m: &nvme_root_t containing endpoints
+ * @e: &nvme_mi_ep_t object, set on each iteration
+ * @_e: &nvme_mi_ep_t object used as temporary storage
+ */
+#define nvme_mi_for_each_endpoint_safe(m, e, _e)			      \
+	for (e = nvme_mi_first_endpoint(m), _e = nvme_mi_next_endpoint(m, e); \
+	     e != NULL;							      \
+	     e = _e, _e = nvme_mi_next_endpoint(m, e))
+
 struct nvme_mi_ctrl;
 
 /**
diff --git a/test/mi.c b/test/mi.c
index c45c9d01..5cea68b7 100644
--- a/test/mi.c
+++ b/test/mi.c
@@ -121,6 +121,37 @@ nvme_mi_ep_t nvme_mi_open_test(nvme_root_t root)
 	return ep;
 }
 
+unsigned int count_root_eps(nvme_root_t root)
+{
+	unsigned int i = 0;
+	nvme_mi_ep_t ep;
+
+	nvme_mi_for_each_endpoint(root, ep)
+		i++;
+
+	return i;
+}
+
+/* test that the root->endpoints list is updated on endpoint
+ * creation/destruction */
+static void test_endpoint_lifetime(nvme_mi_ep_t ep)
+{
+	nvme_root_t root = ep->root;
+	unsigned int count;
+	nvme_mi_ep_t ep2;
+
+	count = count_root_eps(root);
+	assert(count == 1);
+
+	ep2 = nvme_mi_open_test(root);
+	count = count_root_eps(root);
+	assert(count == 2);
+
+	nvme_mi_close(ep2);
+	count = count_root_eps(root);
+	assert(count == 1);
+}
+
 /* test: basic read MI datastructure command */
 static int test_read_mi_data_cb(struct nvme_mi_ep *ep,
 				 struct nvme_mi_req *req,
@@ -357,6 +388,7 @@ struct test {
 	const char *name;
 	void (*fn)(nvme_mi_ep_t);
 } tests[] = {
+	DEFINE_TEST(endpoint_lifetime),
 	DEFINE_TEST(read_mi_data),
 	DEFINE_TEST(transport_fail),
 	DEFINE_TEST(transport_describe),
-- 
2.50.1