Implement splice methods for pipes and sockets.

This also allows the tee(2) implementation to be enabled, since dup can now be
properly supported via WriteTo.

Note that this change necessitated some minor restructoring with the
fs.FileOperations splice methods. If the *fs.File is passed through directly,
then only public API methods are accessible, which will deadlock immediately
since the locking is already done by fs.Splice. Instead, we pass through an
abstract io.Reader or io.Writer, which elide locks and use the underlying
fs.FileOperations directly.

PiperOrigin-RevId: 268805207

1 files changed, 3 insertions, 2 deletions

diff --git a/pkg/sentry/fs/inotify.go b/pkg/sentry/fs/inotify.go
index c7f4e2d13..ba3e0233d 100644
--- a/pkg/sentry/fs/inotify.go
+++ b/pkg/sentry/fs/inotify.go
@@ -15,6 +15,7 @@
 package fs
 
 import (
+	"io"
 	"sync"
 	"sync/atomic"
 
@@ -172,7 +173,7 @@ func (i *Inotify) Read(ctx context.Context, _ *File, dst usermem.IOSequence, _ i
 }
 
 // WriteTo implements FileOperations.WriteTo.
-func (*Inotify) WriteTo(context.Context, *File, *File, SpliceOpts) (int64, error) {
+func (*Inotify) WriteTo(context.Context, *File, io.Writer, int64, bool) (int64, error) {
 	return 0, syserror.ENOSYS
 }
 
@@ -182,7 +183,7 @@ func (*Inotify) Fsync(context.Context, *File, int64, int64, SyncType) error {
 }
 
 // ReadFrom implements FileOperations.ReadFrom.
-func (*Inotify) ReadFrom(context.Context, *File, *File, SpliceOpts) (int64, error) {
+func (*Inotify) ReadFrom(context.Context, *File, io.Reader, int64) (int64, error) {
 	return 0, syserror.ENOSYS
 }