From 471b15b212831af31c2fe36cd42cea7ec7b7785b Mon Sep 17 00:00:00 2001
From: Jamie Liu <jamieliu@google.com>
Date: Tue, 25 Feb 2020 13:25:36 -0800
Subject: Port most syscalls to VFS2.

pipe and pipe2 aren't ported, pending a slight rework of pipe FDs for VFS2.
mount and umount2 aren't ported out of temporary laziness. access and faccessat
need additional FSImpl methods to implement properly, but are stubbed to
prevent googletest from CHECK-failing. Other syscalls require additional
plumbing.

Updates #1623

PiperOrigin-RevId: 297188448
---
 pkg/sentry/syscalls/linux/vfs2/sync.go | 87 ++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 pkg/sentry/syscalls/linux/vfs2/sync.go

(limited to 'pkg/sentry/syscalls/linux/vfs2/sync.go')

diff --git a/pkg/sentry/syscalls/linux/vfs2/sync.go b/pkg/sentry/syscalls/linux/vfs2/sync.go
new file mode 100644
index 000000000..365250b0b
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/sync.go
@@ -0,0 +1,87 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Sync implements Linux syscall sync(2).
+func Sync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	return 0, nil, t.Kernel().VFS().SyncAllFilesystems(t)
+}
+
+// Syncfs implements Linux syscall syncfs(2).
+func Syncfs(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	fd := args[0].Int()
+
+	file := t.GetFileVFS2(fd)
+	if file == nil {
+		return 0, nil, syserror.EBADF
+	}
+	defer file.DecRef()
+
+	return 0, nil, file.SyncFS(t)
+}
+
+// Fsync implements Linux syscall fsync(2).
+func Fsync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	fd := args[0].Int()
+
+	file := t.GetFileVFS2(fd)
+	if file == nil {
+		return 0, nil, syserror.EBADF
+	}
+	defer file.DecRef()
+
+	return 0, nil, file.Sync(t)
+}
+
+// Fdatasync implements Linux syscall fdatasync(2).
+func Fdatasync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	// TODO(gvisor.dev/issue/1897): Avoid writeback of unnecessary metadata.
+	return Fsync(t, args)
+}
+
+// SyncFileRange implements Linux syscall sync_file_range(2).
+func SyncFileRange(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	fd := args[0].Int()
+	offset := args[1].Int64()
+	nbytes := args[2].Int64()
+	flags := args[3].Uint()
+
+	if offset < 0 {
+		return 0, nil, syserror.EINVAL
+	}
+	if nbytes < 0 {
+		return 0, nil, syserror.EINVAL
+	}
+	if flags&^(linux.SYNC_FILE_RANGE_WAIT_BEFORE|linux.SYNC_FILE_RANGE_WRITE|linux.SYNC_FILE_RANGE_WAIT_AFTER) != 0 {
+		return 0, nil, syserror.EINVAL
+	}
+
+	file := t.GetFileVFS2(fd)
+	if file == nil {
+		return 0, nil, syserror.EBADF
+	}
+	defer file.DecRef()
+
+	// TODO(gvisor.dev/issue/1897): Avoid writeback of data ranges outside of
+	// [offset, offset+nbytes).
+	return 0, nil, file.Sync(t)
+}
-- 
cgit v1.2.3