GetDeviceLogicalBlockSize impl for Linux and macOS

osspecifics/osspecifics_cross.go

@@ -0,0 +1,44 @@
+// Linsk - A utility to access Linux-native file systems on non-Linux operating systems.
+// Copyright (c) 2023 The Linsk Authors.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+package osspecifics
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/pkg/errors"
+)
+
+func GetDeviceLogicalBlockSize(devPath string) (uint64, error) {
+	fd, err := os.Open(devPath)
+	if err != nil {
+		return 0, errors.Wrap(err, "open device")
+	}
+
+	defer func() { _ = fd.Close() }()
+
+	bs, err := getDeviceLogicalBlockSizeInner(fd.Fd())
+	if err != nil {
+		return 0, errors.Wrap(err, "get block size inner")
+	}
+
+	if bs <= 0 {
+		return 0, fmt.Errorf("retrieved block size is zero (or negative): '%v'", bs)
+	}
+
+	return uint64(bs), nil
+}

osspecifics/osspecifics_darwin.go

@@ -0,0 +1,26 @@
+// Linsk - A utility to access Linux-native file systems on non-Linux operating systems.
+// Copyright (c) 2023 The Linsk Authors.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+// go:build darwin
+
+func getDeviceLogicalBlockSizeInner(fd uintptr) (int64, error) {
+	bs, err := unix.IoctlGetInt(int(fd.Fd()), 0x40046418) // Syscall code for DKIOGETBLOCKSIZE
+	if err != nil {
+		return 0, errors.Wrap(err, "ioctl get logical block size")
+	}
+
+	return int64(bs), nil
+}

osspecifics/osspecifics_linux.go

@@ -0,0 +1,36 @@
+// Linsk - A utility to access Linux-native file systems on non-Linux operating systems.
+// Copyright (c) 2023 The Linsk Authors.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+// go:build linux
+
+package osspecifics
+
+import (
+	"unsafe"
+
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
+)
+
+func getDeviceLogicalBlockSizeInner(fd uintptr) (int64, error) {
+	var bs int64
+	_, _, serr := unix.Syscall(unix.SYS_IOCTL, fd, unix.BLKSSZGET, uintptr(unsafe.Pointer(&bs)))
+	if serr != 0 {
+		return 0, errors.Wrap(serr, "syscall get logical block size")
+	}
+
+	return int64(bs), nil
+}