containerd/mount/mount_linux_test.go
Wei Fu 67b54c6670 Support >= 128 layers in overlayfs snapshots
Auto-detect longest common dir in lowerdir option and compact it if the
option size is hitting one page size. If does, Use chdir + CLONE to do
mount thing to avoid hitting one page argument buffer in linux kernel
mount.

Signed-off-by: Wei Fu <fhfuwei@163.com>
2018-08-07 10:59:36 +08:00

95 lines
2.2 KiB
Go

// +build linux
/*
Copyright The containerd Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package mount
import (
"reflect"
"testing"
)
func TestLongestCommonPrefix(t *testing.T) {
tcases := []struct {
in []string
expected string
}{
{[]string{}, ""},
{[]string{"foo"}, "foo"},
{[]string{"foo", "bar"}, ""},
{[]string{"foo", "foo"}, "foo"},
{[]string{"foo", "foobar"}, "foo"},
{[]string{"foo", "", "foobar"}, ""},
}
for i, tc := range tcases {
if got := longestCommonPrefix(tc.in); got != tc.expected {
t.Fatalf("[%d case] expected (%s), but got (%s)", i+1, tc.expected, got)
}
}
}
func TestCompactLowerdirOption(t *testing.T) {
tcases := []struct {
opts []string
commondir string
newopts []string
}{
// no lowerdir or only one
{
[]string{"workdir=a"},
"",
[]string{"workdir=a"},
},
{
[]string{"workdir=a", "lowerdir=b"},
"",
[]string{"workdir=a", "lowerdir=b"},
},
// >= 2 lowerdir
{
[]string{"lowerdir=/snapshots/1/fs:/snapshots/10/fs"},
"/snapshots/",
[]string{"lowerdir=1/fs:10/fs"},
},
{
[]string{"lowerdir=/snapshots/1/fs:/snapshots/10/fs:/snapshots/2/fs"},
"/snapshots/",
[]string{"lowerdir=1/fs:10/fs:2/fs"},
},
// if common dir is /
{
[]string{"lowerdir=/snapshots/1/fs:/other_snapshots/1/fs"},
"",
[]string{"lowerdir=/snapshots/1/fs:/other_snapshots/1/fs"},
},
}
for i, tc := range tcases {
dir, opts := compactLowerdirOption(tc.opts)
if dir != tc.commondir {
t.Fatalf("[%d case] expected common dir (%s), but got (%s)", i+1, tc.commondir, dir)
}
if !reflect.DeepEqual(opts, tc.newopts) {
t.Fatalf("[%d case] expected options (%v), but got (%v)", i+1, tc.newopts, opts)
}
}
}