From 33376dd1362be2f63746a8b2feac2de43ca20dbe Mon Sep 17 00:00:00 2001
From: Ben Walker <benjamin.walker@intel.com>
Date: Mon, 20 Nov 2017 11:16:06 -0700
Subject: [PATCH] nvmf: Add subsystem iterators

Add functions to iterate the list of subsystems for a given
target.

Change-Id: Id3831f656033092224168b353788ae87238bf800
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/388294
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
---
 include/spdk/nvmf.h  | 10 ++++++++++
 lib/nvmf/subsystem.c | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/include/spdk/nvmf.h b/include/spdk/nvmf.h
index da90d03cc..cd5389f4c 100644
--- a/include/spdk/nvmf.h
+++ b/include/spdk/nvmf.h
@@ -148,6 +148,16 @@ struct spdk_nvmf_subsystem *spdk_nvmf_create_subsystem(struct spdk_nvmf_tgt *tgt
 struct spdk_nvmf_subsystem *spdk_nvmf_tgt_find_subsystem(struct spdk_nvmf_tgt *tgt,
 		const char *subnqn);
 
+/**
+ * Begin iterating over all known subsystems. If no subsystems are present, return NULL.
+ */
+struct spdk_nvmf_subsystem *spdk_nvmf_subsystem_get_first(struct spdk_nvmf_tgt *tgt);
+
+/**
+ * Continue iterating over all known subsystems. If no additional subsystems, return NULL.
+ */
+struct spdk_nvmf_subsystem *spdk_nvmf_subsystem_get_next(struct spdk_nvmf_subsystem *subsystem);
+
 void spdk_nvmf_delete_subsystem(struct spdk_nvmf_subsystem *subsystem);
 
 /**
diff --git a/lib/nvmf/subsystem.c b/lib/nvmf/subsystem.c
index c5e544be8..e4be6fbd2 100644
--- a/lib/nvmf/subsystem.c
+++ b/lib/nvmf/subsystem.c
@@ -242,6 +242,43 @@ spdk_nvmf_delete_subsystem(struct spdk_nvmf_subsystem *subsystem)
 			      spdk_nvmf_subsystem_delete_done);
 }
 
+struct spdk_nvmf_subsystem *
+spdk_nvmf_subsystem_get_first(struct spdk_nvmf_tgt *tgt)
+{
+	struct spdk_nvmf_subsystem	*subsystem;
+	uint32_t sid;
+
+	for (sid = 0; sid < tgt->max_sid; sid++) {
+		subsystem = tgt->subsystems[sid];
+		if (subsystem) {
+			return subsystem;
+		}
+	}
+
+	return NULL;
+}
+
+struct spdk_nvmf_subsystem *
+spdk_nvmf_subsystem_get_next(struct spdk_nvmf_subsystem *subsystem)
+{
+	uint32_t sid;
+	struct spdk_nvmf_tgt *tgt;
+
+	if (!subsystem) {
+		return NULL;
+	}
+
+	tgt = subsystem->tgt;
+
+	for (sid = subsystem->id + 1; sid < tgt->max_sid; sid++) {
+		subsystem = tgt->subsystems[sid];
+		if (subsystem) {
+			return subsystem;
+		}
+	}
+
+	return NULL;
+}
 
 int
 spdk_nvmf_subsystem_add_host(struct spdk_nvmf_subsystem *subsystem, const char *hostnqn)