Merge branch 'stable/for-jens-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus

Pull xen-blkback fix from Konrad:

"[...] A bug-fix when shutting down xen block backend driver with
 multiple queues and the driver not clearing all of them."

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 792da683e70d..2adb8599be93 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -244,6 +244,7 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
 {
         struct pending_req *req, *n;
         unsigned int j, r;
+        bool busy = false;
 
         for (r = 0; r < blkif->nr_rings; r++) {
                 struct xen_blkif_ring *ring = &blkif->rings[r];
@@ -261,8 +262,10 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
                  * don't have any discard_io or other_io requests. So, checking
                  * for inflight IO is enough.
                  */
-                if (atomic_read(&ring->inflight) > 0)
-                        return -EBUSY;
+                if (atomic_read(&ring->inflight) > 0) {
+                        busy = true;
+                        continue;
+                }
 
                 if (ring->irq) {
                         unbind_from_irqhandler(ring->irq, ring);
@@ -300,6 +303,9 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
                 WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages));
                 ring->active = false;
         }
+        if (busy)
+                return -EBUSY;
+
         blkif->nr_ring_pages = 0;
         /*
          * blkif->rings was allocated in connect_ring, so we should free it in