1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index e79ab4559233..4119bcdefd1a 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -876,7 +876,18 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
         int status = BLKIF_RSP_OKAY;
         struct block_device *bdev = blkif->vbd.bdev;
         unsigned long secure;
+        struct phys_req preq;
+
+        preq.sector_number = req->u.discard.sector_number;
+        preq.nr_sects      = req->u.discard.nr_sectors;
 
+        err = xen_vbd_translate(&preq, blkif, WRITE);
+        if (err) {
+                pr_warn(DRV_PFX "access denied: DISCARD [%llu->%llu] on dev=%04x\n",
+                        preq.sector_number,
+                        preq.sector_number + preq.nr_sects, blkif->vbd.pdevice);
+                goto fail_response;
+        }
         blkif->st_ds_req++;
 
         xen_blkif_get(blkif);
@@ -887,7 +898,7 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
         err = blkdev_issue_discard(bdev, req->u.discard.sector_number,
                                    req->u.discard.nr_sectors,
                                    GFP_KERNEL, secure);
-
+fail_response:
         if (err == -EOPNOTSUPP) {
                 pr_debug(DRV_PFX "discard op failed, not supported\n");
                 status = BLKIF_RSP_EOPNOTSUPP;