nvme: remove indenty ctrl before scan namespace

All nvme host drivers have already identified ctrl beforce scan namespace, so when first time identify ctrl we get the number of namespace and store it into nvme_ctrl. When we scan namespace just use it instead of indentify again.

Signed-off-by weiping zhang <zhangweiping at didichuxing.com>

---
  drivers/nvme/host/core.c | 25 ++++++++++---------------
  drivers/nvme/host/nvme.h |  1 +
  2 files changed, 11 insertions(+), 15 deletions(-)

drivers/nvme/host/core.c +10 -15

index 903d581..34f85df 100644
@@ -1586,6 +1586,7 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
  		ctrl->quirks &= ~NVME_QUIRK_NO_DEEPEST_PS;
  	}
 
+	ctrl->nn = le32_to_cpu(id->nn);
  	ctrl->oacs = le16_to_cpu(id->oacs);
  	ctrl->vid = le16_to_cpu(id->vid);
  	ctrl->oncs = le16_to_cpup(&id->oncs);

@@ -2147,13 +2148,14 @@ static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
  	}
  }
 
-static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn)
+static int nvme_scan_ns_list(struct nvme_ctrl *ctrl)
  {
  	struct nvme_ns *ns;
  	__le32 *ns_list;
-	unsigned i, j, nsid, prev = 0, num_lists = DIV_ROUND_UP(nn, 1024);
+	u32 i, j, nsid, prev = 0, num_lists, nn =  ctrl->nn;
  	int ret = 0;
 
+	num_lists = DIV_ROUND_UP(nn, 1024);
  	ns_list = kzalloc(0x1000, GFP_KERNEL);
  	if (!ns_list)
  		return -ENOMEM;

@@ -2187,41 +2189,34 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn)
  	return ret;
  }
 
-static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl, unsigned nn)
+static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl)
  {
-	unsigned i;
+	u32 i;
 
-	for (i = 1; i <= nn; i++)
+	for (i = 1; i <= ctrl->nn; i++)
  		nvme_validate_ns(ctrl, i);
 
-	nvme_remove_invalid_namespaces(ctrl, nn);
+	nvme_remove_invalid_namespaces(ctrl, ctrl->nn);
  }
 
  static void nvme_scan_work(struct work_struct *work)
  {
  	struct nvme_ctrl *ctrl =
  		container_of(work, struct nvme_ctrl, scan_work);
-	struct nvme_id_ctrl *id;
-	unsigned nn;
 
  	if (ctrl->state != NVME_CTRL_LIVE)
  		return;
 
-	if (nvme_identify_ctrl(ctrl, &id))
-		return;
-
-	nn = le32_to_cpu(id->nn);
  	if (ctrl->vs >= NVME_VS(1, 1, 0) &&
  	    !(ctrl->quirks & NVME_QUIRK_IDENTIFY_CNS)) {
-		if (!nvme_scan_ns_list(ctrl, nn))
+		if (!nvme_scan_ns_list(ctrl))
  			goto done;
  	}
-	nvme_scan_ns_sequential(ctrl, nn);
+	nvme_scan_ns_sequential(ctrl);
   done:
  	mutex_lock(&ctrl->namespaces_mutex);
  	list_sort(NULL, &ctrl->namespaces, ns_cmp);
  	mutex_unlock(&ctrl->namespaces_mutex);
-	kfree(id);
  }
 
  void nvme_queue_scan(struct nvme_ctrl *ctrl)

drivers/nvme/host/nvme.h +1 -0

index 9d6a070..67f373b 100644
@@ -131,6 +131,7 @@ struct nvme_ctrl {
  	struct device *device;	/* char device */
  	struct list_head node;
  	struct ida ns_ida;
+	u32 nn; /* namespace num */
 
  	struct opal_dev *opal_dev;
 

All nvme host drivers have already identified ctrl beforce scan namespace, so when first time identify ctrl we get the number of namespace and store it into nvme_ctrl. When we scan namespace just use it instead of indentify again.

? 2017?6?28??03:39?Keith Busch <keith.busch at intel.com> ???

Quoted 4 lines · weiping zhang

All nvme host drivers have already identified ctrl beforce scan namespace, so when first time identify ctrl we get the number of namespace and store it into nvme_ctrl. When we scan namespace just use it instead of indentify again.

The scan work can be schedule in more than just the reset path, though, which is where ID ctrl is initialized. In those cases, attaching namespaces may stop working.