Merge release-20190806.1-281-g9fb5622 (automated)

1 files changed, 27 insertions, 2 deletions

diff --git a/runsc/cmd/gofer.go b/runsc/cmd/gofer.go
index 4c2fb80bf..4831210c0 100644
--- a/runsc/cmd/gofer.go
+++ b/runsc/cmd/gofer.go
@@ -27,6 +27,7 @@ import (
 	"flag"
 	"github.com/google/subcommands"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/unet"
@@ -135,7 +136,7 @@ func (g *Gofer) Execute(_ context.Context, f *flag.FlagSet, args ...interface{})
 	//
 	// Note that all mount points have been mounted in the proper location in
 	// setupRootFS().
-	cleanMounts, err := resolveMounts(spec.Mounts, root)
+	cleanMounts, err := resolveMounts(conf, spec.Mounts, root)
 	if err != nil {
 		Fatalf("Failure to resolve mounts: %v", err)
 	}
@@ -380,7 +381,7 @@ func setupMounts(mounts []specs.Mount, root string) error {
 // Otherwise, it may follow symlinks to locations that would be overwritten
 // with another mount point and return the wrong location. In short, make sure
 // setupMounts() has been called before.
-func resolveMounts(mounts []specs.Mount, root string) ([]specs.Mount, error) {
+func resolveMounts(conf *boot.Config, mounts []specs.Mount, root string) ([]specs.Mount, error) {
 	cleanMounts := make([]specs.Mount, 0, len(mounts))
 	for _, m := range mounts {
 		if m.Type != "bind" || !specutils.IsSupportedDevMount(m) {
@@ -395,8 +396,15 @@ func resolveMounts(mounts []specs.Mount, root string) ([]specs.Mount, error) {
 		if err != nil {
 			panic(fmt.Sprintf("%q could not be made relative to %q: %v", dst, root, err))
 		}
+
+		opts, err := adjustMountOptions(conf, filepath.Join(root, relDst), m.Options)
+		if err != nil {
+			return nil, err
+		}
+
 		cpy := m
 		cpy.Destination = filepath.Join("/", relDst)
+		cpy.Options = opts
 		cleanMounts = append(cleanMounts, cpy)
 	}
 	return cleanMounts, nil
@@ -453,3 +461,20 @@ func resolveSymlinksImpl(root, base, rel string, followCount uint) (string, erro
 	}
 	return base, nil
 }
+
+// adjustMountOptions adds 'overlayfs_stale_read' if mounting over overlayfs.
+func adjustMountOptions(conf *boot.Config, path string, opts []string) ([]string, error) {
+	rv := make([]string, len(opts))
+	copy(rv, opts)
+
+	if conf.OverlayfsStaleRead {
+		statfs := syscall.Statfs_t{}
+		if err := syscall.Statfs(path, &statfs); err != nil {
+			return nil, err
+		}
+		if statfs.Type == unix.OVERLAYFS_SUPER_MAGIC {
+			rv = append(rv, "overlayfs_stale_read")
+		}
+	}
+	return rv, nil
+}