all: use consistent file permissions

Currently we have unix permissions for new files/dirs
hardcoded throughout the code base. Some places use 0644,
some - 0640, some - 0600 and a variety of other constants.

Introduce osutil.MkdirAll/WriteFile that use the default
permissions and use them throughout the code base.

This makes permissions consistent and also allows to easily
change the permissions later if we change our minds.

Also merge pkg/fileutil into pkg/osutil as they become
dependent on each other. The line between them was poorly
defined anyway as both operate on files.

3 files changed, 0 insertions, 196 deletions

diff --git a/pkg/fileutil/fileutil.go b/pkg/fileutil/fileutil.go
deleted file mode 100644
index 056eee50f..000000000
--- a/pkg/fileutil/fileutil.go
+++ /dev/null
@@ -1,107 +0,0 @@
-// Copyright 2015 syzkaller project authors. All rights reserved.
-// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
-
-package fileutil
-
-import (
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"strconv"
-	"syscall"
-)
-
-// CopyFile atomically copies oldFile to newFile preserving permissions and modification time.
-func CopyFile(oldFile, newFile string) error {
-	oldf, err := os.Open(oldFile)
-	if err != nil {
-		return err
-	}
-	defer oldf.Close()
-	stat, err := oldf.Stat()
-	if err != nil {
-		return err
-	}
-	tmpFile := newFile + ".tmp"
-	newf, err := os.OpenFile(tmpFile, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, stat.Mode()&os.ModePerm)
-	if err != nil {
-		return err
-	}
-	defer newf.Close()
-	_, err = io.Copy(newf, oldf)
-	if err != nil {
-		return err
-	}
-	if err := newf.Close(); err != nil {
-		return err
-	}
-	if err := os.Chtimes(tmpFile, stat.ModTime(), stat.ModTime()); err != nil {
-		return err
-	}
-	return os.Rename(tmpFile, newFile)
-}
-
-// WriteTempFile writes data to a temp file and returns its name.
-func WriteTempFile(data []byte) (string, error) {
-	f, err := ioutil.TempFile("", "syzkaller")
-	if err != nil {
-		return "", fmt.Errorf("failed to create a temp file: %v", err)
-	}
-	if _, err := f.Write(data); err != nil {
-		f.Close()
-		os.Remove(f.Name())
-		return "", fmt.Errorf("failed to write a temp file: %v", err)
-	}
-	f.Close()
-	return f.Name(), nil
-}
-
-// ProcessTempDir creates a new temp dir in where and returns its path and an unique index.
-// It also cleans up old, unused temp dirs after dead processes.
-func ProcessTempDir(where string) (string, error) {
-	lk := filepath.Join(where, "instance-lock")
-	lkf, err := syscall.Open(lk, syscall.O_RDWR|syscall.O_CREAT, 0600)
-	if err != nil {
-		return "", err
-	}
-	defer syscall.Close(lkf)
-	if err := syscall.Flock(lkf, syscall.LOCK_EX); err != nil {
-		return "", err
-	}
-	defer syscall.Flock(lkf, syscall.LOCK_UN)
-
-	for i := 0; i < 1e3; i++ {
-		path := filepath.Join(where, fmt.Sprintf("instance-%v", i))
-		pidfile := filepath.Join(path, ".pid")
-		err := os.Mkdir(path, 0700)
-		if os.IsExist(err) {
-			// Try to clean up.
-			data, err := ioutil.ReadFile(pidfile)
-			if err == nil && len(data) > 0 {
-				pid, err := strconv.Atoi(string(data))
-				if err == nil && pid > 1 {
-					if err := syscall.Kill(pid, 0); err == syscall.ESRCH {
-						if os.Remove(pidfile) == nil {
-							if os.RemoveAll(path) == nil {
-								i--
-								continue
-							}
-						}
-					}
-				}
-			}
-			// If err != nil, assume that the pid file is not created yet.
-			continue
-		}
-		if err != nil {
-			return "", err
-		}
-		if err := ioutil.WriteFile(pidfile, []byte(strconv.Itoa(syscall.Getpid())), 0600); err != nil {
-			return "", err
-		}
-		return path, nil
-	}
-	return "", fmt.Errorf("too many live instances")
-}
diff --git a/pkg/fileutil/fileutil_linux.go b/pkg/fileutil/fileutil_linux.go
deleted file mode 100644
index 217036256..000000000
--- a/pkg/fileutil/fileutil_linux.go
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright 2017 syzkaller project authors. All rights reserved.
-// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
-
-package fileutil
-
-import (
-	"io/ioutil"
-	"path/filepath"
-	"syscall"
-	"unsafe"
-)
-
-// UmountAll recurusively unmounts all mounts in dir.
-func UmountAll(dir string) {
-	files, _ := ioutil.ReadDir(dir)
-	for _, f := range files {
-		name := filepath.Join(dir, f.Name())
-		if f.IsDir() {
-			UmountAll(name)
-		}
-		fn := []byte(name + "\x00")
-		syscall.Syscall(syscall.SYS_UMOUNT2, uintptr(unsafe.Pointer(&fn[0])), syscall.MNT_FORCE, 0)
-	}
-}
diff --git a/pkg/fileutil/fileutil_test.go b/pkg/fileutil/fileutil_test.go
deleted file mode 100644
index d432ef5e7..000000000
--- a/pkg/fileutil/fileutil_test.go
+++ /dev/null
@@ -1,65 +0,0 @@
-// Copyright 2015 syzkaller project authors. All rights reserved.
-// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
-
-package fileutil
-
-import (
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"strconv"
-	"sync"
-	"testing"
-)
-
-func TestProcessTempDir(t *testing.T) {
-	for try := 0; try < 10; try++ {
-		func() {
-			tmp, err := ioutil.TempDir("", "syz")
-			if err != nil {
-				t.Fatalf("failed to create a temp dir: %v", err)
-			}
-			defer os.RemoveAll(tmp)
-			const P = 16
-			// Pre-create half of the instances with stale pid.
-			var dirs []string
-			for i := 0; i < P/2; i++ {
-				dir, err := ProcessTempDir(tmp)
-				if err != nil {
-					t.Fatalf("failed to create process temp dir")
-				}
-				dirs = append(dirs, dir)
-			}
-			for _, dir := range dirs {
-				if err := ioutil.WriteFile(filepath.Join(dir, ".pid"), []byte(strconv.Itoa(999999999)), 0600); err != nil {
-					t.Fatalf("failed to write pid file: %v", err)
-				}
-			}
-			// Now request a bunch of instances concurrently.
-			done := make(chan bool)
-			allDirs := make(map[string]bool)
-			var mu sync.Mutex
-			for p := 0; p < P; p++ {
-				go func() {
-					defer func() {
-						done <- true
-					}()
-					dir, err := ProcessTempDir(tmp)
-					if err != nil {
-						t.Fatalf("failed to create process temp dir")
-					}
-					mu.Lock()
-					present := allDirs[dir]
-					allDirs[dir] = true
-					mu.Unlock()
-					if present {
-						t.Fatalf("duplicate dir %v", dir)
-					}
-				}()
-			}
-			for p := 0; p < P; p++ {
-				<-done
-			}
-		}()
-	}
-}