xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing)

[linux-2.6-block.git] / drivers / block / xen-blkfront.c

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index fc770b7d3beb1951e80c2f16956f3dd0897efe48..c8fdbc77f9b1774c259f62b82ba2e03b302001d7 100644 (file)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1074,12 +1074,6 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
                s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments;
 
        if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
-               /*
-                * Copy the data received from the backend into the bvec.
-                * Since bv_offset can be different than 0, and bv_len different
-                * than PAGE_SIZE, we have to keep track of the current offset,
-                * to be sure we are copying the data from the right shared page.
-                */
                for_each_sg(s->sg, sg, nseg, i) {
                        BUG_ON(sg->offset + sg->length > PAGE_SIZE);
                        shared_data = kmap_atomic(
@@ -1974,7 +1968,8 @@ static void blkback_changed(struct xenbus_device *dev,
                        break;
                /* Missed the backend's Closing state -- fallthrough */
        case XenbusStateClosing:
-               blkfront_closing(info);
+               if (info)
+                       blkfront_closing(info);
                break;
        }
 }