[PATCH v2 rfc 1/3] nvme: split nvme_remove_namespaces

[Sagi Grimberg]

In controller deletion we will need to add a state transition
after we flush the namespace scanning, and continue to the
namespace removal afterwards. Hence, split nvme_remove_namespaces
so that we can add this change only in the nvme_do_delete_ctrl
call site.

Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
---
 drivers/nvme/host/core.c | 29 ++++++++++++++++++++---------
 drivers/nvme/host/nvme.h |  3 ++-
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 509bf4e1d423..f1bb2a522cf0 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4091,16 +4091,8 @@ static void nvme_scan_work(struct work_struct *work)
 	up_write(&ctrl->namespaces_rwsem);
 }
 
-/*
- * This function iterates the namespace list unlocked to allow recovery from
- * controller failure. It is up to the caller to ensure the namespace list is
- * not modified by scan work while this function is executing.
- */
-void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
+void nvme_prep_remove_namespaces(struct nvme_ctrl *ctrl)
 {
-	struct nvme_ns *ns, *next;
-	LIST_HEAD(ns_list);
-
 	/*
 	 * make sure to requeue I/O to all namespaces as these
 	 * might result from the scan itself and must complete
@@ -4119,6 +4111,13 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
 	 */
 	if (ctrl->state == NVME_CTRL_DEAD)
 		nvme_kill_queues(ctrl);
+}
+EXPORT_SYMBOL_GPL(nvme_prep_remove_namespaces);
+
+void nvme_do_remove_namespaces(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns, *next;
+	LIST_HEAD(ns_list);
 
 	down_write(&ctrl->namespaces_rwsem);
 	list_splice_init(&ctrl->namespaces, &ns_list);
@@ -4127,6 +4126,18 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
 	list_for_each_entry_safe(ns, next, &ns_list, list)
 		nvme_ns_remove(ns);
 }
+EXPORT_SYMBOL_GPL(nvme_do_remove_namespaces);
+
+/*
+ * This function iterates the namespace list unlocked to allow recovery from
+ * controller failure. It is up to the caller to ensure the namespace list is
+ * not modified by scan work while this function is executing.
+ */
+void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
+{
+	nvme_prep_remove_namespaces(ctrl);
+	nvme_do_remove_namespaces(ctrl);
+}
 EXPORT_SYMBOL_GPL(nvme_remove_namespaces);
 
 static int nvme_class_uevent(struct device *dev, struct kobj_uevent_env *env)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 85d76981b66e..f184ae623f12 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -530,7 +530,8 @@ void nvme_uninit_ctrl(struct nvme_ctrl *ctrl);
 void nvme_start_ctrl(struct nvme_ctrl *ctrl);
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_identify(struct nvme_ctrl *ctrl);
-
+void nvme_prep_remove_namespaces(struct nvme_ctrl *ctrl);
+void nvme_do_remove_namespaces(struct nvme_ctrl *ctrl);
 void nvme_remove_namespaces(struct nvme_ctrl *ctrl);
 
 int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len,
-- 
2.25.1