add copy test for ext4

filesystem/ext4/checksum.go

@@ -29,8 +29,6 @@ func directoryChecksummer(seed, inodeNumber, inodeGeneration uint32) checksummer
 // directoryChecksumAppender returns a function that implements checksumAppender for a directory entries block
 // original calculations can be seen for e2fsprogs https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/tree/lib/ext2fs/csum.c#n301
 // and in the linux tree https://github.com/torvalds/linux/blob/master/fs/ext4/namei.c#L376-L384
-//
-//nolint:unparam // inodeGeneration is always 0
 func directoryChecksumAppender(seed, inodeNumber, inodeGeneration uint32) checksumAppender {
 	fn := directoryChecksummer(seed, inodeNumber, inodeGeneration)
 	return func(b []byte) []byte {

filesystem/ext4/directory.go

@@ -19,7 +19,7 @@ type Directory struct {
 }
 
 // toBytes convert our entries to raw bytes. Provides checksum as well. Final returned byte slice will be a multiple of bytesPerBlock.
-func (d *Directory) toBytes(bytesPerBlock uint32, checksumFunc checksumAppender) []byte {
+func (d *Directory) toBytes(bytesPerBlock uint32, checksumFunc checksumAppender, withChecksums bool) []byte {
 	b := make([]byte, 0)
 	var (
 		previousLength int
@@ -30,26 +30,47 @@ func (d *Directory) toBytes(bytesPerBlock uint32, checksumFunc checksumAppender)
 	if len(d.entries) == 0 {
 		return b
 	}
+	checksumSize := 0
+	if withChecksums {
+		checksumSize = minDirEntryLength
+	}
+	blockLimit := int(bytesPerBlock) - checksumSize
 	lastEntryCount = len(d.entries) - 1
 	for i, de := range d.entries {
 		b2 := de.toBytes(0)
 		switch {
-		case len(block)+len(b2) > int(bytesPerBlock)-minDirEntryLength:
+		case len(block)+len(b2) > blockLimit:
 			// if adding this one will go past the end of the block, pad out the previous
 			block = block[:len(block)-previousLength]
-			previousB := previousEntry.toBytes(uint16(int(bytesPerBlock) - len(block) - minDirEntryLength))
+			previousB := previousEntry.toBytes(uint16(blockLimit - len(block)))
 			block = append(block, previousB...)
 			// add the checksum
-			block = checksumFunc(block)
+			if withChecksums {
+				block = checksumFunc(block)
+			}
 			b = append(b, block...)
 			// start a new block
 			block = make([]byte, 0)
+			// add current entry to the new block
+			if i == lastEntryCount {
+				b2 = de.toBytes(uint16(blockLimit - len(block)))
+				block = append(block, b2...)
+				if withChecksums {
+					block = checksumFunc(block)
+				}
+				b = append(b, block...)
+				block = make([]byte, 0)
+			} else {
+				block = append(block, b2...)
+			}
 		case i == lastEntryCount:
 			// if this is the last one, pad it out
-			b2 = de.toBytes(uint16(int(bytesPerBlock) - len(block) - minDirEntryLength))
+			b2 = de.toBytes(uint16(blockLimit - len(block)))
 			block = append(block, b2...)
 			// add the checksum
-			block = checksumFunc(block)
+			if withChecksums {
+				block = checksumFunc(block)
+			}
 			b = append(b, block...)
 			// start a new block
 			block = make([]byte, 0)

filesystem/ext4/directory_test.go

@@ -16,7 +16,7 @@ func TestDirectoryToBytes(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	b := dir.toBytes(bytesPerBlock, directoryChecksumAppender(sb.checksumSeed, 2, 0))
+	b := dir.toBytes(bytesPerBlock, directoryChecksumAppender(sb.checksumSeed, 2, 0), true)
 
 	// read the bytes from the disk
 	diff, diffString := testhelper.DumpByteSlicesWithDiffs(b, expected, 32, false, true, true)

filesystem/ext4/directoryentry.go

@@ -184,19 +184,32 @@ type directoryEntryInfo struct {
 }
 
 func (de *directoryEntryInfo) Info() (iofs.FileInfo, error) {
+	mode := iofs.FileMode(0)
+	isDir := de.directoryEntry.fileType == dirFileTypeDirectory
+	if isDir {
+		mode |= iofs.ModeDir
+	}
+	if de.inode != nil && de.inode.fileType == fileTypeSymbolicLink {
+		mode |= iofs.ModeSymlink
+	}
 	return &FileInfo{
 		modTime: de.modifyTime,
 		name:    de.filename,
 		size:    int64(de.size),
-		isDir:   de.directoryEntry.fileType == dirFileTypeDirectory,
+		isDir:   isDir,
+		mode:    mode,
 	}, nil
 }
 
 func (de *directoryEntryInfo) Type() iofs.FileMode {
+	mode := iofs.FileMode(0)
 	if de.directoryEntry.fileType == dirFileTypeDirectory {
-		return iofs.ModeDir
+		mode |= iofs.ModeDir
+	}
+	if de.inode != nil && de.inode.fileType == fileTypeSymbolicLink {
+		mode |= iofs.ModeSymlink
 	}
-	return 0
+	return mode
 }
 
 func (de *directoryEntryInfo) IsDir() bool {