nvme-multipath: use vmalloc for ANA log buffer

The ANA log buffer can get really large, as it depends on the
controller configuration. So to avoid an out-of-memory issue
during scanning use kvmalloc() instead of the kmalloc().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Author: hreinecke

drivers/nvme/host/multipath.c

@@ -5,6 +5,7 @@
 
 #include <linux/backing-dev.h>
 #include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
 #include <trace/events/block.h>
 #include "nvme.h"
 
@@ -898,7 +899,7 @@ 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);
 		nvme_mpath_uninit(ctrl);
-		ctrl->ana_log_buf = kmalloc(ana_log_size, GFP_KERNEL);
+		ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL);
 		if (!ctrl->ana_log_buf)
 			return -ENOMEM;
 	}
@@ -915,7 +916,7 @@ int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 
 void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
 {
-	kfree(ctrl->ana_log_buf);
+	kvfree(ctrl->ana_log_buf);
 	ctrl->ana_log_buf = NULL;
 	ctrl->ana_log_size = 0;
 }