Clear Merkle files before measuring verity fs

PiperOrigin-RevId: 390467957

runsc/cmd/verity_prepare.go

@@ -82,7 +82,7 @@ func (c *VerityPrepare) Execute(_ context.Context, f *flag.FlagSet, args ...inte
 		},
 		Process: &specs.Process{
 			Cwd:          absRoot,
-			Args:         []string{c.tool, "--path", "/verityroot"},
+			Args:         []string{c.tool, "--path", "/verityroot", "--rawpath", "/rawroot"},
 			Env:          os.Environ(),
 			Capabilities: specutils.AllCapabilities(),
 		},
@@ -94,6 +94,11 @@ func (c *VerityPrepare) Execute(_ context.Context, f *flag.FlagSet, args ...inte
 				Type:        "bind",
 				Options:     []string{"verity.roothash="},
 			},
+			{
+				Source:      c.dir,
+				Destination: "/rawroot",
+				Type:        "bind",
+			},
 		},
 	}
 

tools/verity/measure_tool.go

@@ -21,12 +21,14 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"strings"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 )
 
 var path = flag.String("path", "", "path to the verity file system.")
+var rawpath = flag.String("rawpath", "", "path to the raw file system.")
 
 const maxDigestSize = 64
 
@@ -40,6 +42,14 @@ func main() {
 	if *path == "" {
 		log.Fatalf("no path provided")
 	}
+	if *rawpath == "" {
+		log.Fatalf("no rawpath provided")
+	}
+	// TODO(b/182315468): Optimize the Merkle tree generate process to
+	// allow only updating certain files/directories.
+	if err := clearMerkle(*rawpath); err != nil {
+		log.Fatalf("Failed to clear merkle files in %s: %v", *rawpath, err)
+	}
 	if err := enableDir(*path); err != nil {
 		log.Fatalf("Failed to enable file system %s: %v", *path, err)
 	}
@@ -49,6 +59,26 @@ func main() {
 	}
 }
 
+func clearMerkle(path string) error {
+	files, err := ioutil.ReadDir(path)
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		if file.IsDir() {
+			if err := clearMerkle(path + "/" + file.Name()); err != nil {
+				return err
+			}
+		} else if strings.HasPrefix(file.Name(), ".merkle.verity") {
+			if err := os.Remove(path + "/" + file.Name()); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 // enableDir enables verity features on all the files and sub-directories within
 // path.
 func enableDir(path string) error {