 67b54c6670
			
		
	
	67b54c6670
	
	
	
		
			
			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>
		
			
				
	
	
		
			95 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // +build linux
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| 
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| /*
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|    Copyright The containerd Authors.
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| 
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|    Licensed under the Apache License, Version 2.0 (the "License");
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|    you may not use this file except in compliance with the License.
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|    You may obtain a copy of the License at
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| 
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|        http://www.apache.org/licenses/LICENSE-2.0
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| 
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|    Unless required by applicable law or agreed to in writing, software
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|    distributed under the License is distributed on an "AS IS" BASIS,
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|    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|    See the License for the specific language governing permissions and
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|    limitations under the License.
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| */
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| 
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| package mount
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| 
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| import (
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| 	"reflect"
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| 	"testing"
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| )
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| 
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| func TestLongestCommonPrefix(t *testing.T) {
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| 	tcases := []struct {
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| 		in       []string
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| 		expected string
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| 	}{
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| 		{[]string{}, ""},
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| 		{[]string{"foo"}, "foo"},
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| 		{[]string{"foo", "bar"}, ""},
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| 		{[]string{"foo", "foo"}, "foo"},
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| 		{[]string{"foo", "foobar"}, "foo"},
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| 		{[]string{"foo", "", "foobar"}, ""},
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| 	}
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| 
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| 	for i, tc := range tcases {
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| 		if got := longestCommonPrefix(tc.in); got != tc.expected {
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| 			t.Fatalf("[%d case] expected (%s), but got (%s)", i+1, tc.expected, got)
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| 		}
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| 	}
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| }
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| 
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| func TestCompactLowerdirOption(t *testing.T) {
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| 	tcases := []struct {
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| 		opts      []string
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| 		commondir string
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| 		newopts   []string
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| 	}{
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| 		// no lowerdir or only one
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| 		{
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| 			[]string{"workdir=a"},
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| 			"",
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| 			[]string{"workdir=a"},
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| 		},
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| 		{
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| 			[]string{"workdir=a", "lowerdir=b"},
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| 			"",
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| 			[]string{"workdir=a", "lowerdir=b"},
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| 		},
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| 
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| 		// >= 2 lowerdir
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| 		{
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| 			[]string{"lowerdir=/snapshots/1/fs:/snapshots/10/fs"},
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| 			"/snapshots/",
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| 			[]string{"lowerdir=1/fs:10/fs"},
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| 		},
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| 		{
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| 			[]string{"lowerdir=/snapshots/1/fs:/snapshots/10/fs:/snapshots/2/fs"},
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| 			"/snapshots/",
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| 			[]string{"lowerdir=1/fs:10/fs:2/fs"},
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| 		},
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| 
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| 		// if common dir is /
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| 		{
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| 			[]string{"lowerdir=/snapshots/1/fs:/other_snapshots/1/fs"},
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| 			"",
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| 			[]string{"lowerdir=/snapshots/1/fs:/other_snapshots/1/fs"},
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| 		},
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| 	}
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| 
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| 	for i, tc := range tcases {
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| 		dir, opts := compactLowerdirOption(tc.opts)
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| 		if dir != tc.commondir {
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| 			t.Fatalf("[%d case] expected common dir (%s), but got (%s)", i+1, tc.commondir, dir)
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| 		}
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| 
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| 		if !reflect.DeepEqual(opts, tc.newopts) {
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| 			t.Fatalf("[%d case] expected options (%v), but got (%v)", i+1, tc.newopts, opts)
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| 		}
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| 	}
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| }
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