185 lines
4.6 KiB
Go
185 lines
4.6 KiB
Go
|
// Copyright 2019 The gVisor 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 ext
|
||
|
|
||
|
import (
|
||
|
"bytes"
|
||
|
"testing"
|
||
|
|
||
|
"github.com/google/go-cmp/cmp"
|
||
|
"github.com/google/go-cmp/cmp/cmpopts"
|
||
|
"gvisor.dev/gvisor/pkg/binary"
|
||
|
"gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout"
|
||
|
)
|
||
|
|
||
|
// TestExtentTree tests the extent tree building logic.
|
||
|
//
|
||
|
// Test tree:
|
||
|
// 0.{Head}[Idx][Idx]
|
||
|
// / \
|
||
|
// / \
|
||
|
// 1.{Head}[Ext][Ext] 2.{Head}[Idx]
|
||
|
// / | \
|
||
|
// [Phy] [Phy, Phy] 3.{Head}[Ext]
|
||
|
// |
|
||
|
// [Phy, Phy, Phy]
|
||
|
//
|
||
|
// Legend:
|
||
|
// - Head = ExtentHeader
|
||
|
// - Idx = ExtentIdx
|
||
|
// - Ext = Extent
|
||
|
// - Phy = Physical Block
|
||
|
//
|
||
|
// Please note that ext4 might not construct extent trees looking like this.
|
||
|
// This is purely for testing the tree traversal logic.
|
||
|
func TestExtentTree(t *testing.T) {
|
||
|
blkSize := uint64(64) // No block has more than 1 header + 4 entries.
|
||
|
mockDisk := make([]byte, blkSize*10)
|
||
|
mockInode := &inode{diskInode: &disklayout.InodeNew{}}
|
||
|
|
||
|
node3 := &disklayout.ExtentNode{
|
||
|
Header: disklayout.ExtentHeader{
|
||
|
Magic: disklayout.ExtentMagic,
|
||
|
NumEntries: 1,
|
||
|
MaxEntries: 4,
|
||
|
Height: 0,
|
||
|
},
|
||
|
Entries: []disklayout.ExtentEntryPair{
|
||
|
{
|
||
|
Entry: &disklayout.Extent{
|
||
|
FirstFileBlock: 3,
|
||
|
Length: 3,
|
||
|
StartBlockLo: 6,
|
||
|
},
|
||
|
Node: nil,
|
||
|
},
|
||
|
},
|
||
|
}
|
||
|
|
||
|
node2 := &disklayout.ExtentNode{
|
||
|
Header: disklayout.ExtentHeader{
|
||
|
Magic: disklayout.ExtentMagic,
|
||
|
NumEntries: 1,
|
||
|
MaxEntries: 4,
|
||
|
Height: 1,
|
||
|
},
|
||
|
Entries: []disklayout.ExtentEntryPair{
|
||
|
{
|
||
|
Entry: &disklayout.ExtentIdx{
|
||
|
FirstFileBlock: 3,
|
||
|
ChildBlockLo: 2,
|
||
|
},
|
||
|
Node: node3,
|
||
|
},
|
||
|
},
|
||
|
}
|
||
|
|
||
|
node1 := &disklayout.ExtentNode{
|
||
|
Header: disklayout.ExtentHeader{
|
||
|
Magic: disklayout.ExtentMagic,
|
||
|
NumEntries: 2,
|
||
|
MaxEntries: 4,
|
||
|
Height: 0,
|
||
|
},
|
||
|
Entries: []disklayout.ExtentEntryPair{
|
||
|
{
|
||
|
Entry: &disklayout.Extent{
|
||
|
FirstFileBlock: 0,
|
||
|
Length: 1,
|
||
|
StartBlockLo: 3,
|
||
|
},
|
||
|
Node: nil,
|
||
|
},
|
||
|
{
|
||
|
Entry: &disklayout.Extent{
|
||
|
FirstFileBlock: 1,
|
||
|
Length: 2,
|
||
|
StartBlockLo: 4,
|
||
|
},
|
||
|
Node: nil,
|
||
|
},
|
||
|
},
|
||
|
}
|
||
|
|
||
|
node0 := &disklayout.ExtentNode{
|
||
|
Header: disklayout.ExtentHeader{
|
||
|
Magic: disklayout.ExtentMagic,
|
||
|
NumEntries: 2,
|
||
|
MaxEntries: 4,
|
||
|
Height: 2,
|
||
|
},
|
||
|
Entries: []disklayout.ExtentEntryPair{
|
||
|
{
|
||
|
Entry: &disklayout.ExtentIdx{
|
||
|
FirstFileBlock: 0,
|
||
|
ChildBlockLo: 0,
|
||
|
},
|
||
|
Node: node1,
|
||
|
},
|
||
|
{
|
||
|
Entry: &disklayout.ExtentIdx{
|
||
|
FirstFileBlock: 3,
|
||
|
ChildBlockLo: 1,
|
||
|
},
|
||
|
Node: node2,
|
||
|
},
|
||
|
},
|
||
|
}
|
||
|
|
||
|
writeTree(mockInode, mockDisk, node0, blkSize)
|
||
|
|
||
|
r := bytes.NewReader(mockDisk)
|
||
|
if err := mockInode.buildExtTree(r, blkSize); err != nil {
|
||
|
t.Fatalf("inode.buildExtTree failed: %v", err)
|
||
|
}
|
||
|
|
||
|
if diff := cmp.Diff(&mockInode.root, node0, cmpopts.IgnoreUnexported(disklayout.ExtentNode{})); diff != "" {
|
||
|
t.Errorf("extent tree mismatch (-want +got):\n%s", diff)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// writeTree writes the tree represented by `root` to the inode and disk passed.
|
||
|
func writeTree(in *inode, disk []byte, root *disklayout.ExtentNode, blkSize uint64) {
|
||
|
rootData := binary.Marshal(nil, binary.LittleEndian, root.Header)
|
||
|
for _, ep := range root.Entries {
|
||
|
rootData = binary.Marshal(rootData, binary.LittleEndian, ep.Entry)
|
||
|
}
|
||
|
|
||
|
copy(in.diskInode.Data(), rootData)
|
||
|
|
||
|
if root.Header.Height > 0 {
|
||
|
for _, ep := range root.Entries {
|
||
|
writeTreeToDisk(disk, ep, blkSize)
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// writeTreeToDisk is the recursive step for writeTree which writes the tree
|
||
|
// on the disk only.
|
||
|
func writeTreeToDisk(disk []byte, curNode disklayout.ExtentEntryPair, blkSize uint64) {
|
||
|
nodeData := binary.Marshal(nil, binary.LittleEndian, curNode.Node.Header)
|
||
|
for _, ep := range curNode.Node.Entries {
|
||
|
nodeData = binary.Marshal(nodeData, binary.LittleEndian, ep.Entry)
|
||
|
}
|
||
|
|
||
|
copy(disk[curNode.Entry.PhysicalBlock()*blkSize:], nodeData)
|
||
|
|
||
|
if curNode.Node.Header.Height > 0 {
|
||
|
for _, ep := range curNode.Node.Entries {
|
||
|
writeTreeToDisk(disk, ep, blkSize)
|
||
|
}
|
||
|
}
|
||
|
}
|