Merge tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Xen features and fixes for 4.10

  These are some fixes, a move of some arm related headers to share them
  between arm and arm64 and a series introducing a helper to make code
  more readable.

  The most notable change is David stepping down as maintainer of the
  Xen hypervisor interface. This results in me sending you the pull
  requests for Xen related code from now on"

* tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits)
  xen/balloon: Only mark a page as managed when it is released
  xenbus: fix deadlock on writes to /proc/xen/xenbus
  xen/scsifront: don't request a slot on the ring until request is ready
  xen/x86: Increase xen_e820_map to E820_X_MAX possible entries
  x86: Make E820_X_MAX unconditionally larger than E820MAX
  xen/pci: Bubble up error and fix description.
  xen: xenbus: set error code on failure
  xen: set error code on failures
  arm/xen: Use alloc_percpu rather than __alloc_percpu
  arm/arm64: xen: Move shared architecture headers to include/xen/arm
  xen/events: use xen_vcpu_id mapping for EVTCHNOP_status
  xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing
  xen-scsifront: Add a missing call to kfree
  MAINTAINERS: update XEN HYPERVISOR INTERFACE
  xenfs: Use proc_create_mount_point() to create /proc/xen
  xen-platform: use builtin_pci_driver
  xen-netback: fix error handling output
  xen: make use of xenbus_read_unsigned() in xenbus
  xen: make use of xenbus_read_unsigned() in xen-pciback
  xen: make use of xenbus_read_unsigned() in xen-fbfront
  ...

1 files changed, 14 insertions, 22 deletions

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 3cc6d1d86f1e..415e79b69d34 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -533,13 +533,11 @@ static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info
 	struct xenbus_device *dev = be->dev;
 	struct xen_blkif *blkif = be->blkif;
 	int err;
-	int state = 0, discard_enable;
+	int state = 0;
 	struct block_device *bdev = be->blkif->vbd.bdev;
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	err = xenbus_scanf(XBT_NIL, dev->nodename, "discard-enable", "%d",
-			   &discard_enable);
-	if (err == 1 && !discard_enable)
+	if (!xenbus_read_unsigned(dev->nodename, "discard-enable", 1))
 		return;
 
 	if (blk_queue_discard(q)) {
@@ -1039,30 +1037,24 @@ static int connect_ring(struct backend_info *be)
 		xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol);
 		return -ENOSYS;
 	}
-	err = xenbus_scanf(XBT_NIL, dev->otherend,
-			   "feature-persistent", "%u", &pers_grants);
-	if (err <= 0)
-		pers_grants = 0;
-
+	pers_grants = xenbus_read_unsigned(dev->otherend, "feature-persistent",
+					   0);
 	be->blkif->vbd.feature_gnt_persistent = pers_grants;
 	be->blkif->vbd.overflow_max_grants = 0;
 
 	/*
 	 * Read the number of hardware queues from frontend.
 	 */
-	err = xenbus_scanf(XBT_NIL, dev->otherend, "multi-queue-num-queues",
-			   "%u", &requested_num_queues);
-	if (err < 0) {
-		requested_num_queues = 1;
-	} else {
-		if (requested_num_queues > xenblk_max_queues
-		    || requested_num_queues == 0) {
-			/* Buggy or malicious guest. */
-			xenbus_dev_fatal(dev, err,
-					"guest requested %u queues, exceeding the maximum of %u.",
-					requested_num_queues, xenblk_max_queues);
-			return -ENOSYS;
-		}
+	requested_num_queues = xenbus_read_unsigned(dev->otherend,
+						    "multi-queue-num-queues",
+						    1);
+	if (requested_num_queues > xenblk_max_queues
+	    || requested_num_queues == 0) {
+		/* Buggy or malicious guest. */
+		xenbus_dev_fatal(dev, err,
+				"guest requested %u queues, exceeding the maximum of %u.",
+				requested_num_queues, xenblk_max_queues);
+		return -ENOSYS;
 	}
 	be->blkif->nr_rings = requested_num_queues;
 	if (xen_blkif_alloc_rings(be->blkif))