nvme-multipath: set ana_log_size to 0 after free ana_log_buf

Set ana_log_size to 0 when ana_log_buf is freed to make sure
nvme_mpath_init_identify will do the right thing when retrying
after an earlier failure.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Author: Hou Tao

drivers/nvme/host/multipath.c

@@ -866,7 +866,7 @@ int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 	}
 	if (ana_log_size > ctrl->ana_log_size) {
 		nvme_mpath_stop(ctrl);
-		kfree(ctrl->ana_log_buf);
+		nvme_mpath_uninit(ctrl);
 		ctrl->ana_log_buf = kmalloc(ana_log_size, GFP_KERNEL);
 		if (!ctrl->ana_log_buf)
 			return -ENOMEM;
@@ -886,4 +886,5 @@ void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
 {
 	kfree(ctrl->ana_log_buf);
 	ctrl->ana_log_buf = NULL;
+	ctrl->ana_log_size = 0;
 }