Merge 4.4.258 into android-4.4-p

Changes in 4.4.258
	tracing: Do not count ftrace events in top level enable output
	fgraph: Initialize tracing_graph_pause at task creation
	af_key: relax availability checks for skb size calculation
	iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap
	iwlwifi: mvm: guard against device removal in reprobe
	SUNRPC: Move simple_get_bytes and simple_get_netobj into private header
	SUNRPC: Handle 0 length opaque XDR object data properly
	lib/string: Add strscpy_pad() function
	include/trace/events/writeback.h: fix -Wstringop-truncation warnings
	memcg: fix a crash in wb_workfn when a device disappears
	squashfs: add more sanity checks in id lookup
	squashfs: add more sanity checks in inode lookup
	squashfs: add more sanity checks in xattr id lookup
	memblock: do not start bottom-up allocations with kernel_end
	netfilter: xt_recent: Fix attempt to update deleted entry
	h8300: fix PREEMPTION build, TI_PRE_COUNT undefined
	usb: dwc3: ulpi: fix checkpatch warning
	usb: dwc3: ulpi: Replace CPU-based busyloop with Protocol-based one
	net: watchdog: hold device global xmit lock during tx disable
	vsock: fix locking in vsock_shutdown()
	x86/build: Disable CET instrumentation in the kernel for 32-bit too
	trace: Use -mcount-record for dynamic ftrace
	tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount
	tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
	Xen/x86: don't bail early from clear_foreign_p2m_mapping()
	Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()
	Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()
	Xen/gntdev: correct error checking in gntdev_map_grant_pages()
	xen/arm: don't ignore return errors from set_phys_to_machine
	xen-blkback: don't "handle" error by BUG()
	xen-netback: don't "handle" error by BUG()
	xen-scsiback: don't "handle" error by BUG()
	xen-blkback: fix error handling in xen_blkbk_map()
	scsi: qla2xxx: Fix crash during driver load on big endian machines
	kvm: check tlbs_dirty directly
	Linux 4.4.258

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ie1125773ccbc457f93c639c420dedf2c38a5e65a

1 files changed, 16 insertions, 12 deletions

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 8dbdd156e0d3..f9dfcd8872af 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -825,8 +825,11 @@ again:
 			pages[i]->page = persistent_gnt->page;
 			pages[i]->persistent_gnt = persistent_gnt;
 		} else {
-			if (get_free_page(blkif, &pages[i]->page))
-				goto out_of_memory;
+			if (get_free_page(blkif, &pages[i]->page)) {
+				put_free_pages(blkif, pages_to_gnt, segs_to_map);
+				ret = -ENOMEM;
+				goto out;
+			}
 			addr = vaddr(pages[i]->page);
 			pages_to_gnt[segs_to_map] = pages[i]->page;
 			pages[i]->persistent_gnt = NULL;
@@ -842,10 +845,8 @@ again:
 			break;
 	}
 
-	if (segs_to_map) {
+	if (segs_to_map)
 		ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
-		BUG_ON(ret);
-	}
 
 	/*
 	 * Now swizzle the MFN in our domain with the MFN from the other domain
@@ -860,7 +861,7 @@ again:
 				pr_debug("invalid buffer -- could not remap it\n");
 				put_free_pages(blkif, &pages[seg_idx]->page, 1);
 				pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
-				ret |= 1;
+				ret |= !ret;
 				goto next;
 			}
 			pages[seg_idx]->handle = map[new_map_idx].handle;
@@ -912,15 +913,18 @@ next:
 	}
 	segs_to_map = 0;
 	last_map = map_until;
-	if (map_until != num)
+	if (!ret && map_until != num)
 		goto again;
 
-	return ret;
+out:
+	for (i = last_map; i < num; i++) {
+		/* Don't zap current batch's valid persistent grants. */
+		if(i >= last_map + segs_to_map)
+			pages[i]->persistent_gnt = NULL;
+		pages[i]->handle = BLKBACK_INVALID_HANDLE;
+	}
 
-out_of_memory:
-	pr_alert("%s: out of memory\n", __func__);
-	put_free_pages(blkif, pages_to_gnt, segs_to_map);
-	return -ENOMEM;
+	return ret;
 }
 
 static int xen_blkbk_map_seg(struct pending_req *pending_req)