[PATCH 3/9] libnvme: annotate nvme_subsystem::iopolicy with !accessors:none

[Nilay Shroff <nilay@linux.ibm.com>]

The default accessor generation creates getters that return cached
attribute values. However, for nvme_subsystem::iopolicy, a real-time
(non-cached) value is required.

This is particularly useful for tools such as nvme-top, which rely on
up-to-date information for displaying a real-time dashboard.

Annotate nvme_subsystem::iopolicy with "!accessors:none" to disable the
auto-generated accessor, and provide a custom implementation of
nvme_subsystem_get_iopolicy() that returns the current value.

Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
---
 libnvme/src/accessors.ld     |  2 --
 libnvme/src/libnvme.ld       |  1 +
 libnvme/src/nvme/accessors.c | 13 -------------
 libnvme/src/nvme/accessors.h | 17 -----------------
 libnvme/src/nvme/private.h   |  2 +-
 libnvme/src/nvme/tree.c      | 15 +++++++++++++++
 libnvme/src/nvme/tree.h      |  8 ++++++++
 7 files changed, 25 insertions(+), 33 deletions(-)

diff --git a/libnvme/src/accessors.ld b/libnvme/src/accessors.ld
index 433767191..56348a7e5 100644
--- a/libnvme/src/accessors.ld
+++ b/libnvme/src/accessors.ld
@@ -77,8 +77,6 @@ LIBNVME_ACCESSORS_3 {
 		nvme_subsystem_get_subsystype;
 		nvme_subsystem_get_application;
 		nvme_subsystem_set_application;
-		nvme_subsystem_get_iopolicy;
-		nvme_subsystem_set_iopolicy;
 		nvme_host_get_hostnqn;
 		nvme_host_get_hostid;
 		nvme_host_get_dhchap_host_key;
diff --git a/libnvme/src/libnvme.ld b/libnvme/src/libnvme.ld
index 41a170083..f842eb770 100644
--- a/libnvme/src/libnvme.ld
+++ b/libnvme/src/libnvme.ld
@@ -176,6 +176,7 @@ LIBNVME_3 {
 		nvme_subsystem_first_ns;
 		nvme_get_subsystem;
 		nvme_subsystem_get_host;
+		nvme_subsystem_get_iopolicy;
 		nvme_subsystem_lookup_namespace;
 		nvme_subsystem_next_ctrl;
 		nvme_subsystem_next_ns;
diff --git a/libnvme/src/nvme/accessors.c b/libnvme/src/nvme/accessors.c
index a98f26234..55fd11320 100644
--- a/libnvme/src/nvme/accessors.c
+++ b/libnvme/src/nvme/accessors.c
@@ -404,19 +404,6 @@ __public const char *nvme_subsystem_get_application(
 	return p->application;
 }
 
-__public void nvme_subsystem_set_iopolicy(
-		struct nvme_subsystem *p,
-		const char *iopolicy)
-{
-	free(p->iopolicy);
-	p->iopolicy = iopolicy ? strdup(iopolicy) : NULL;
-}
-
-__public const char *nvme_subsystem_get_iopolicy(const struct nvme_subsystem *p)
-{
-	return p->iopolicy;
-}
-
 /****************************************************************************
  * Accessors for: struct nvme_host
  ****************************************************************************/
diff --git a/libnvme/src/nvme/accessors.h b/libnvme/src/nvme/accessors.h
index f9323ad11..9ea96a634 100644
--- a/libnvme/src/nvme/accessors.h
+++ b/libnvme/src/nvme/accessors.h
@@ -575,23 +575,6 @@ void nvme_subsystem_set_application(
  */
 const char *nvme_subsystem_get_application(const struct nvme_subsystem *p);
 
-/**
- * nvme_subsystem_set_iopolicy() - Set iopolicy.
- * @p: The &struct nvme_subsystem instance to update.
- * @iopolicy: New string; a copy is stored. Pass NULL to clear.
- */
-void nvme_subsystem_set_iopolicy(
-		struct nvme_subsystem *p,
-		const char *iopolicy);
-
-/**
- * nvme_subsystem_get_iopolicy() - Get iopolicy.
- * @p: The &struct nvme_subsystem instance to query.
- *
- * Return: The value of the iopolicy field, or NULL if not set.
- */
-const char *nvme_subsystem_get_iopolicy(const struct nvme_subsystem *p);
-
 /****************************************************************************
  * Accessors for: struct nvme_host
  ****************************************************************************/
diff --git a/libnvme/src/nvme/private.h b/libnvme/src/nvme/private.h
index dcd9079dd..84852c8b0 100644
--- a/libnvme/src/nvme/private.h
+++ b/libnvme/src/nvme/private.h
@@ -230,7 +230,7 @@ struct nvme_subsystem { /*!generate-accessors*/
 	char *firmware; /*!accessors:readonly*/
 	char *subsystype; /*!accessors:readonly*/
 	char *application;
-	char *iopolicy;
+	char *iopolicy; //!accessors:none
 };
 
 struct nvme_host { /*!generate-accessors*/
diff --git a/libnvme/src/nvme/tree.c b/libnvme/src/nvme/tree.c
index 2984d0ff7..18aabe044 100644
--- a/libnvme/src/nvme/tree.c
+++ b/libnvme/src/nvme/tree.c
@@ -445,6 +445,21 @@ __public nvme_host_t nvme_subsystem_get_host(nvme_subsystem_t s)
 	return s->h;
 }
 
+__public char *nvme_subsystem_get_iopolicy(nvme_subsystem_t s)
+{
+	_cleanup_free_ char *iopolicy = NULL;
+
+	iopolicy = nvme_get_subsys_attr(s, "iopolicy");
+	if (iopolicy) {
+		if (!s->iopolicy || strcmp(iopolicy, s->iopolicy)) {
+			free(s->iopolicy);
+			s->iopolicy = strdup(iopolicy);
+		}
+	}
+
+	return s->iopolicy;
+}
+
 __public nvme_ns_t nvme_subsystem_first_ns(nvme_subsystem_t s)
 {
 	return list_top(&s->namespaces, struct nvme_ns, entry);
diff --git a/libnvme/src/nvme/tree.h b/libnvme/src/nvme/tree.h
index 1240f3023..39d715508 100644
--- a/libnvme/src/nvme/tree.h
+++ b/libnvme/src/nvme/tree.h
@@ -212,6 +212,14 @@ void nvme_free_subsystem(struct nvme_subsystem *s);
  */
 nvme_host_t nvme_subsystem_get_host(nvme_subsystem_t s);
 
+/**
+ * nvme_subsystem_get_iopolicy() - Get subsystem iopolicy name
+ * @s:	subsystem
+ *
+ * Return: The iopolicy configured in subsystem @s
+ */
+char *nvme_subsystem_get_iopolicy(nvme_subsystem_t s);
+
 /**
  * nvme_ctrl_first_ns() - Start namespace iterator
  * @c:	Controller instance
-- 
2.53.0