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

2 files changed, 5 insertions, 3 deletions

diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD
index b06e46c03..b5f89033b 100644
--- a/test/syscalls/BUILD
+++ b/test/syscalls/BUILD
@@ -255,7 +255,7 @@ syscall_test(test = "//test/syscalls/linux:pause_test")
 
 syscall_test(
     size = "large",
-    add_overlay = False,  # TODO(gvisor.dev/issue/318): enable when fixed.
+    add_overlay = True,
     shard_count = 5,
     test = "//test/syscalls/linux:pipe_test",
 )
diff --git a/test/syscalls/linux/pipe.cc b/test/syscalls/linux/pipe.cc
index 1f4422f4e..65afb90f3 100644
--- a/test/syscalls/linux/pipe.cc
+++ b/test/syscalls/linux/pipe.cc
@@ -339,11 +339,13 @@ TEST_P(PipeTest, BlockPartialWriteClosed) {
   SKIP_IF(!CreateBlocking());
 
   ScopedThread t([this]() {
-    std::vector<char> buf(2 * Size());
+    const int pipe_size = Size();
+    std::vector<char> buf(2 * pipe_size);
+
     // Write more than fits in the buffer. Blocks then returns partial write
     // when the other end is closed. The next call returns EPIPE.
     ASSERT_THAT(write(wfd_.get(), buf.data(), buf.size()),
-                SyscallSucceedsWithValue(Size()));
+                SyscallSucceedsWithValue(pipe_size));
     EXPECT_THAT(write(wfd_.get(), buf.data(), buf.size()),
                 SyscallFailsWithErrno(EPIPE));
   });