3 files changed, 34 insertions, 61 deletions

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 70caa896997..73f196ca713 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -398,21 +398,18 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
 	int err = 0;
 	int status = BLKIF_RSP_OKAY;
 	struct block_device *bdev = blkif->vbd.bdev;
+	unsigned long secure;
 
 	blkif->st_ds_req++;
 
 	xen_blkif_get(blkif);
-	if (blkif->blk_backend_type == BLKIF_BACKEND_PHY ||
-	    blkif->blk_backend_type == BLKIF_BACKEND_FILE) {
-		unsigned long secure = (blkif->vbd.discard_secure &&
-			(req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
-			BLKDEV_DISCARD_SECURE : 0;
-		err = blkdev_issue_discard(bdev,
-				req->u.discard.sector_number,
-				req->u.discard.nr_sectors,
-				GFP_KERNEL, secure);
-	} else
-		err = -EOPNOTSUPP;
+	secure = (blkif->vbd.discard_secure &&
+		 (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
+		 BLKDEV_DISCARD_SECURE : 0;
+
+	err = blkdev_issue_discard(bdev, req->u.discard.sector_number,
+				   req->u.discard.nr_sectors,
+				   GFP_KERNEL, secure);
 
 	if (err == -EOPNOTSUPP) {
 		pr_debug(DRV_PFX "discard op failed, not supported\n");
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index d0ee7edc9be..773cf27dc23 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -146,11 +146,6 @@ enum blkif_protocol {
 	BLKIF_PROTOCOL_X86_64 = 3,
 };
 
-enum blkif_backend_type {
-	BLKIF_BACKEND_PHY  = 1,
-	BLKIF_BACKEND_FILE = 2,
-};
-
 struct xen_vbd {
 	/* What the domain refers to this vbd as. */
 	blkif_vdev_t		handle;
@@ -177,7 +172,6 @@ struct xen_blkif {
 	unsigned int		irq;
 	/* Comms information. */
 	enum blkif_protocol	blk_protocol;
-	enum blkif_backend_type blk_backend_type;
 	union blkif_back_rings	blk_rings;
 	void			*blk_ring;
 	/* The VBD attached to this interface. */
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 24a2fb57e5d..d417c13e027 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -390,61 +390,43 @@ int xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be)
 {
 	struct xenbus_device *dev = be->dev;
 	struct xen_blkif *blkif = be->blkif;
-	char *type;
 	int err;
 	int state = 0;
+	struct block_device *bdev = be->blkif->vbd.bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
 
-	type = xenbus_read(XBT_NIL, dev->nodename, "type", NULL);
-	if (!IS_ERR(type)) {
-		if (strncmp(type, "file", 4) == 0) {
-			state = 1;
-			blkif->blk_backend_type = BLKIF_BACKEND_FILE;
+	if (blk_queue_discard(q)) {
+		err = xenbus_printf(xbt, dev->nodename,
+			"discard-granularity", "%u",
+			q->limits.discard_granularity);
+		if (err) {
+			xenbus_dev_fatal(dev, err,
+				"writing discard-granularity");
+			goto out;
+		}
+		err = xenbus_printf(xbt, dev->nodename,
+			"discard-alignment", "%u",
+			q->limits.discard_alignment);
+		if (err) {
+			xenbus_dev_fatal(dev, err,
+				"writing discard-alignment");
+			goto out;
 		}
-		if (strncmp(type, "phy", 3) == 0) {
-			struct block_device *bdev = be->blkif->vbd.bdev;
-			struct request_queue *q = bdev_get_queue(bdev);
-			if (blk_queue_discard(q)) {
-				err = xenbus_printf(xbt, dev->nodename,
-					"discard-granularity", "%u",
-					q->limits.discard_granularity);
-				if (err) {
-					xenbus_dev_fatal(dev, err,
-						"writing discard-granularity");
-					goto kfree;
-				}
-				err = xenbus_printf(xbt, dev->nodename,
-					"discard-alignment", "%u",
-					q->limits.discard_alignment);
-				if (err) {
-					xenbus_dev_fatal(dev, err,
-						"writing discard-alignment");
-					goto kfree;
-				}
-				state = 1;
-				blkif->blk_backend_type = BLKIF_BACKEND_PHY;
-			}
-			/* Optional. */
-			err = xenbus_printf(xbt, dev->nodename,
-				"discard-secure", "%d",
-				blkif->vbd.discard_secure);
-			if (err) {
-				xenbus_dev_fatal(dev, err,
+		state = 1;
+		/* Optional. */
+		err = xenbus_printf(xbt, dev->nodename,
+				    "discard-secure", "%d",
+				    blkif->vbd.discard_secure);
+		if (err) {
+			xenbus_dev_fatal(dev, err,
 					"writting discard-secure");
-				goto kfree;
-			}
+			goto out;
 		}
-	} else {
-		err = PTR_ERR(type);
-		xenbus_dev_fatal(dev, err, "reading type");
-		goto out;
 	}
-
 	err = xenbus_printf(xbt, dev->nodename, "feature-discard",
 			    "%d", state);
 	if (err)
 		xenbus_dev_fatal(dev, err, "writing feature-discard");
-kfree:
-	kfree(type);
 out:
 	return err;
 }