Add vfs.Pathname{WithDeleted,ForGetcwd}.

The former is needed for vfs.FileDescription to implement
memmap.MappingIdentity, and the latter is needed to implement getcwd(2).

PiperOrigin-RevId: 285051855

2 files changed, 9 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/memfs/BUILD b/pkg/sentry/fsimpl/memfs/BUILD
index bc5c0b591..0cc751eb8 100644
--- a/pkg/sentry/fsimpl/memfs/BUILD
+++ b/pkg/sentry/fsimpl/memfs/BUILD
@@ -32,6 +32,7 @@ go_library(
     deps = [
         "//pkg/abi/linux",
         "//pkg/amutex",
+        "//pkg/fspath",
         "//pkg/sentry/arch",
         "//pkg/sentry/context",
         "//pkg/sentry/kernel/auth",
diff --git a/pkg/sentry/fsimpl/memfs/filesystem.go b/pkg/sentry/fsimpl/memfs/filesystem.go
index 08a9cb8ef..1f2a5122a 100644
--- a/pkg/sentry/fsimpl/memfs/filesystem.go
+++ b/pkg/sentry/fsimpl/memfs/filesystem.go
@@ -19,6 +19,7 @@ import (
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserror"
@@ -582,3 +583,10 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
 	inode.decLinksLocked()
 	return nil
 }
+
+// PrependPath implements vfs.FilesystemImpl.PrependPath.
+func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDentry, b *fspath.Builder) error {
+	fs.mu.RLock()
+	defer fs.mu.RUnlock()
+	return vfs.GenericPrependPath(vfsroot, vd, b)
+}