Complete pipe support on overlayfs

Get/Set pipe size and ioctl support were missing from
overlayfs. It required moving the pipe.Sizer interface
to fs so that overlay could get access.

Fixes #318

PiperOrigin-RevId: 255511125

1 files changed, 12 insertions, 1 deletions

diff --git a/pkg/sentry/fs/file_operations.go b/pkg/sentry/fs/file_operations.go
index 2c5bd1b19..d86f5bf45 100644
--- a/pkg/sentry/fs/file_operations.go
+++ b/pkg/sentry/fs/file_operations.go
@@ -155,5 +155,16 @@ type FileOperations interface {
 	// refer.
 	//
 	// Preconditions: The AddressSpace (if any) that io refers to is activated.
-	Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error)
+	Ioctl(ctx context.Context, file *File, io usermem.IO, args arch.SyscallArguments) (uintptr, error)
+}
+
+// FifoSizer is an interface for setting and getting the size of a pipe.
+type FifoSizer interface {
+	// FifoSize returns the pipe capacity in bytes.
+	FifoSize(ctx context.Context, file *File) (int64, error)
+
+	// SetFifoSize sets the new pipe capacity in bytes.
+	//
+	// The new size is returned (which may be capped).
+	SetFifoSize(size int64) (int64, error)
 }