Get system's real page size

unix.Getpagesize use fixed 65536 as pagesize in arm64, but we need real
system pagesize. It usually to be 4096.
Signed-off-by: NWangFengTu <wangfengtu@huawei.com>

iSulad-img.spec

 %global _version 2.0.0
-%global _release 20200407.154716.git43a6aabf
+%global _release 20200420.005423.git3cd302f6
 Name:       iSulad-img
 Version:    %{_version}
 Release:    %{_release}

patch/0051-Get-system-s-real-page-size.patch

+From 484fc2ace248e41fea95c19d6b33684a315b9089 Mon Sep 17 00:00:00 2001
+From: WangFengTu <wangfengtu@huawei.com>
+Date: Mon, 20 Apr 2020 10:35:59 +0800
+Subject: [PATCH] Get system's real page size
+
+unix.Getpagesize use fixed 65536 as pagesize in arm64, but we need real
+system pagesize. It usually to be 4096.
+
+Signed-off-by: WangFengTu <wangfengtu@huawei.com>
+---
+ .../containers/storage/drivers/overlay/overlay.go          | 7 ++++---
+ 1 file changed, 4 insertions(+), 3 deletions(-)
+
+diff --git a/vendor/github.com/containers/storage/drivers/overlay/overlay.go b/vendor/github.com/containers/storage/drivers/overlay/overlay.go
+index 3e9f650..6b7d053 100644
+--- a/vendor/github.com/containers/storage/drivers/overlay/overlay.go
++++ b/vendor/github.com/containers/storage/drivers/overlay/overlay.go
+@@ -14,6 +14,7 @@ import (
+ 	"strconv"
+ 	"strings"
+ 	"sync"
++	"syscall"
+ 
+ 	"bufio"
+ 	"github.com/containers/storage/drivers"
+@@ -344,7 +345,7 @@ func supportsMultipleLowerDir(home string, homeMagic graphdriver.FsMagic, rootUI
+ 		_ = idtools.MkdirAs(lower1Dir, 0700, rootUID, rootGID)
+ 		_ = idtools.MkdirAs(lower2Dir, 0700, rootUID, rootGID)
+ 		flags := fmt.Sprintf("lowerdir=%s:%s", lower1Dir, lower2Dir)
+-		if len(flags) < unix.Getpagesize() {
++		if len(flags) < syscall.Getpagesize() {
+ 			err := mountFrom(filepath.Dir(home), "overlay", mergedDir, "overlay", 0, flags)
+ 			if err == nil {
+ 				logrus.Debugf("overlay test mount with multiple lowers succeeded")
+@@ -354,7 +355,7 @@ func supportsMultipleLowerDir(home string, homeMagic graphdriver.FsMagic, rootUI
+ 			}
+ 		}
+ 		flags = fmt.Sprintf("lowerdir=%s", lower1Dir)
+-		if len(flags) < unix.Getpagesize() {
++		if len(flags) < syscall.Getpagesize() {
+ 			err := mountFrom(filepath.Dir(home), "overlay", mergedDir, "overlay", 0, flags)
+ 			if err == nil {
+ 				logrus.Errorf("overlay test mount with multiple lowers failed, but succeeded with a single lower")
+@@ -815,7 +816,7 @@ func (d *Driver) get(id string, disableShifting bool, options graphdriver.MountO
+ 	mountFunc := unix.Mount
+ 	mountTarget := mergedDir
+ 
+-	pageSize := unix.Getpagesize()
++	pageSize := syscall.Getpagesize()
+ 
+ 	// Use relative paths and mountFrom when the mount data has exceeded
+ 	// the page size. The mount syscall fails if the mount data cannot
+-- 
+2.19.1
+

patch/series-patch.conf

@@ -48,3 +48,4 @@
 0048-Check-all-links-in-lowers-file-but-not-parent-link-o.patch
 0049-Delete-related-names-when-delete-layer.patch
 0050-calculate-target-size-if-layer-blob-is-symlink.patch
+0051-Get-system-s-real-page-size.patch