diff options
Diffstat (limited to 'pkg/sentry/fs/ext/extent_test.go')
| -rw-r--r-- | pkg/sentry/fs/ext/extent_test.go | 165 |
1 files changed, 133 insertions, 32 deletions
diff --git a/pkg/sentry/fs/ext/extent_test.go b/pkg/sentry/fs/ext/extent_test.go index 01251d0a7..fb7921add 100644 --- a/pkg/sentry/fs/ext/extent_test.go +++ b/pkg/sentry/fs/ext/extent_test.go @@ -16,6 +16,8 @@ package ext import ( "bytes" + "io" + "math/rand" "testing" "github.com/google/go-cmp/cmp" @@ -24,9 +26,14 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout" ) -// TestExtentTree tests the extent tree building logic. +const ( + // mockExtentBlkSize is the mock block size used for testing. + // No block has more than 1 header + 4 entries. + mockExtentBlkSize = uint64(64) +) + +// The tree described below looks like: // -// Test tree: // 0.{Head}[Idx][Idx] // / \ // / \ @@ -44,18 +51,8 @@ import ( // // 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) - mockExtentFile := extentFile{ - regFile: regularFile{ - inode: inode{ - diskInode: &disklayout.InodeNew{}, - }, - }, - } - - node3 := &disklayout.ExtentNode{ +var ( + node3 = &disklayout.ExtentNode{ Header: disklayout.ExtentHeader{ Magic: disklayout.ExtentMagic, NumEntries: 1, @@ -74,7 +71,7 @@ func TestExtentTree(t *testing.T) { }, } - node2 := &disklayout.ExtentNode{ + node2 = &disklayout.ExtentNode{ Header: disklayout.ExtentHeader{ Magic: disklayout.ExtentMagic, NumEntries: 1, @@ -92,7 +89,7 @@ func TestExtentTree(t *testing.T) { }, } - node1 := &disklayout.ExtentNode{ + node1 = &disklayout.ExtentNode{ Header: disklayout.ExtentHeader{ Magic: disklayout.ExtentMagic, NumEntries: 2, @@ -119,7 +116,7 @@ func TestExtentTree(t *testing.T) { }, } - node0 := &disklayout.ExtentNode{ + node0 = &disklayout.ExtentNode{ Header: disklayout.ExtentHeader{ Magic: disklayout.ExtentMagic, NumEntries: 2, @@ -143,22 +140,95 @@ func TestExtentTree(t *testing.T) { }, }, } +) - writeTree(&mockExtentFile.regFile.inode, mockDisk, node0, blkSize) +// TestExtentReader tests extentReader functionality. We should be able to use +// the file reader like any other io.Reader. +func TestExtentReader(t *testing.T) { + type extentReaderTest struct { + name string + from func(uint64) uint64 + to func(uint64) uint64 + } - r := bytes.NewReader(mockDisk) - if err := mockExtentFile.buildExtTree(r, blkSize); err != nil { - t.Fatalf("inode.buildExtTree failed: %v", err) + tests := []extentReaderTest{ + { + name: "read first half", + from: beginning, + to: middle, + }, + { + name: "read entire file", + from: beginning, + to: end, + }, + { + name: "read second half", + from: middle, + to: end, + }, } + dev, mockExtentFile, want := extentTreeSetUp(t, node0) + size := mockExtentFile.regFile.inode.diskInode.Size() + + for _, test := range tests { + from := test.from(size) + to := test.to(size) + fileReader := mockExtentFile.getFileReader(dev, mockExtentBlkSize, from) + + got := make([]byte, to-from) + if _, err := io.ReadFull(fileReader, got); err != nil { + t.Errorf("file read failed: %v", err) + } + + if diff := cmp.Diff(got, want[from:to]); diff != "" { + t.Errorf("file data mismatch (-want +got):\n%s", diff) + } + } +} + +// TestBuildExtentTree tests the extent tree building logic. +func TestBuildExtentTree(t *testing.T) { + _, mockExtentFile, _ := extentTreeSetUp(t, node0) + opt := cmpopts.IgnoreUnexported(disklayout.ExtentIdx{}, disklayout.ExtentHeader{}) if diff := cmp.Diff(&mockExtentFile.root, node0, opt); 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) { +// extentTreeSetUp writes the passed extent tree to a mock disk as an extent +// tree. It also constucts a mock extent file with the same tree built in it. +// It also writes random data file data and returns it. +func extentTreeSetUp(t *testing.T, root *disklayout.ExtentNode) (io.ReadSeeker, *extentFile, []byte) { + t.Helper() + + mockDisk := make([]byte, mockExtentBlkSize*10) + mockExtentFile := &extentFile{ + regFile: regularFile{ + inode: inode{ + diskInode: &disklayout.InodeNew{ + InodeOld: disklayout.InodeOld{ + SizeLo: uint32(mockExtentBlkSize) * getNumPhyBlks(root), + }, + }, + }, + }, + } + + fileData := writeTree(&mockExtentFile.regFile.inode, mockDisk, node0, mockExtentBlkSize) + + r := bytes.NewReader(mockDisk) + if err := mockExtentFile.buildExtTree(r, mockExtentBlkSize); err != nil { + t.Fatalf("inode.buildExtTree failed: %v", err) + } + return r, mockExtentFile, fileData +} + +// writeTree writes the tree represented by `root` to the inode and disk. It +// also writes random file data on disk. +func writeTree(in *inode, disk []byte, root *disklayout.ExtentNode, mockExtentBlkSize uint64) []byte { rootData := binary.Marshal(nil, binary.LittleEndian, root.Header) for _, ep := range root.Entries { rootData = binary.Marshal(rootData, binary.LittleEndian, ep.Entry) @@ -166,26 +236,57 @@ func writeTree(in *inode, disk []byte, root *disklayout.ExtentNode, blkSize uint copy(in.diskInode.Data(), rootData) - if root.Header.Height > 0 { - for _, ep := range root.Entries { - writeTreeToDisk(disk, ep, blkSize) + var fileData []byte + for _, ep := range root.Entries { + if root.Header.Height == 0 { + fileData = append(fileData, writeRandomFileData(disk, ep.Entry.(*disklayout.Extent))...) + } else { + fileData = append(fileData, writeTreeToDisk(disk, ep)...) } } + return fileData } // writeTreeToDisk is the recursive step for writeTree which writes the tree -// on the disk only. -func writeTreeToDisk(disk []byte, curNode disklayout.ExtentEntryPair, blkSize uint64) { +// on the disk only. Also writes random file data on disk. +func writeTreeToDisk(disk []byte, curNode disklayout.ExtentEntryPair) []byte { 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) + copy(disk[curNode.Entry.PhysicalBlock()*mockExtentBlkSize:], nodeData) + + var fileData []byte + for _, ep := range curNode.Node.Entries { + if curNode.Node.Header.Height == 0 { + fileData = append(fileData, writeRandomFileData(disk, ep.Entry.(*disklayout.Extent))...) + } else { + fileData = append(fileData, writeTreeToDisk(disk, ep)...) + } + } + return fileData +} + +// writeRandomFileData writes random bytes to the blocks on disk that the +// passed extent points to. +func writeRandomFileData(disk []byte, ex *disklayout.Extent) []byte { + phyExStartBlk := ex.PhysicalBlock() + phyExStartOff := phyExStartBlk * mockExtentBlkSize + phyExEndOff := phyExStartOff + uint64(ex.Length)*mockExtentBlkSize + rand.Read(disk[phyExStartOff:phyExEndOff]) + return disk[phyExStartOff:phyExEndOff] +} - if curNode.Node.Header.Height > 0 { - for _, ep := range curNode.Node.Entries { - writeTreeToDisk(disk, ep, blkSize) +// getNumPhyBlks returns the number of physical blocks covered under the node. +func getNumPhyBlks(node *disklayout.ExtentNode) uint32 { + var res uint32 + for _, ep := range node.Entries { + if node.Header.Height == 0 { + res += uint32(ep.Entry.(*disklayout.Extent).Length) + } else { + res += getNumPhyBlks(ep.Node) } } + return res } |