OP#792 initial commit after fork

internal/disk/fdatasync_linux.go

@@ -0,0 +1,47 @@
+//go:build linux
+// +build linux
+
+// Copyright (c) 2015-2021 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package disk
+
+import (
+	"os"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// Fdatasync - fdatasync() is similar to fsync(), but does not flush modified metadata
+// unless that metadata is needed in order to allow a subsequent data retrieval
+// to  be  correctly  handled.   For example, changes to st_atime or st_mtime
+// (respectively, time of last access and time of last modification; see inode(7))
+// do not require flushing because they are not necessary for a subsequent data
+// read to be handled correctly. On the other hand, a change to the file size
+// (st_size, as made by say ftruncate(2)), would require a metadata flush.
+//
+// The aim of fdatasync() is to reduce disk activity for applications that
+// do not require all metadata to be synchronized with the disk.
+func Fdatasync(f *os.File) error {
+	return syscall.Fdatasync(int(f.Fd()))
+}
+
+// FadviseDontNeed invalidates page-cache
+func FadviseDontNeed(f *os.File) error {
+	return unix.Fadvise(int(f.Fd()), 0, 0, unix.FADV_DONTNEED)
+}