xen/xen-blkback: preq.dev is used without initialized

If call xen_vbd_translate failed, the preq.dev will be not initialized.
Use blkif->vbd.pdevice instead (still better to print relative info).

Note that before commit 01c681d4c70d64cb72142a2823f27c4146a02e63
(xen/blkback: Don't trust the handle from the frontend.)
the value bogus, as it was the guest provided value from req->u.rw.handle
rather than the actual device.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index de1f319f7bd7e0118a960b5bd23fd286a6ba343e..6d1cc3df2ac66706db6029dd1b368c043e7688ed 100644 (file)
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -904,7 +904,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
                pr_debug(DRV_PFX "access denied: %s of [%llu,%llu] on dev=%04x\n",
                         operation == READ ? "read" : "write",
                         preq.sector_number,
-                        preq.sector_number + preq.nr_sects, preq.dev);
+                        preq.sector_number + preq.nr_sects,
+                        blkif->vbd.pdevice);
                goto fail_response;
        }