virtio_blk: VIRTIO_BLK_F_WCE->VIRTIO_BLK_F_FLUSH

[cascardo/linux.git] / drivers / block / virtio_blk.c

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 6ca3549..28cff0d 100644 (file)
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -477,8 +477,13 @@ static int virtblk_get_cache_mode(struct virtio_device *vdev)
        err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
                                   struct virtio_blk_config, wce,
                                   &writeback);
+
+       /*
+        * If WCE is not configurable and flush is not available,
+        * assume no writeback cache is in use.
+        */
        if (err)
-               writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
+               writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
 
        return writeback;
 }
@@ -833,14 +838,14 @@ static const struct virtio_device_id id_table[] = {
 static unsigned int features_legacy[] = {
        VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
        VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
-       VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
+       VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
        VIRTIO_BLK_F_MQ,
 }
 ;
 static unsigned int features[] = {
        VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
        VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
-       VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
+       VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
        VIRTIO_BLK_F_MQ,
 };