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go/src/os/path_test.go
David du Colombier 32f994acc6 os: fix RemoveAll on large directories on Plan 9 and NaCl
On Plan 9, some file servers, like ramfs, handle the read
offset when reading directories. However, the offset isn't
valid anymore after directory entries have been removed
between successive calls to read.

This issue happens when os.RemoveAll is called on a
directory that doesn't fit on a single 9P response message.

In this case, the first part of the directory is read,
then directory entries are removed and the second read
will be incomplete because the read offset won't be valid
anymore. Consequently, the content of the directory will
only be partially removed.

We change RemoveAll to call fd.Seek(0, 0) before calling
fd.Readdirnames, so the read offset will always be reset
after removing the directory entries.

After adding TestRemoveAllLarge, we noticed the same issue
appears on NaCl and the same fix applies as well.

Fixes #22572.

Change-Id: Ifc76ea7ccaf0168c34dc8ec0f400dc04db1baf8f
Reviewed-on: https://go-review.googlesource.com/75974
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-11-06 07:09:50 +00:00

254 lines
6.3 KiB
Go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package os_test
import (
"fmt"
"internal/testenv"
"io/ioutil"
. "os"
"path/filepath"
"runtime"
"syscall"
"testing"
)
var isReadonlyError = func(error) bool { return false }
func TestMkdirAll(t *testing.T) {
tmpDir := TempDir()
path := tmpDir + "/_TestMkdirAll_/dir/./dir2"
err := MkdirAll(path, 0777)
if err != nil {
t.Fatalf("MkdirAll %q: %s", path, err)
}
defer RemoveAll(tmpDir + "/_TestMkdirAll_")
// Already exists, should succeed.
err = MkdirAll(path, 0777)
if err != nil {
t.Fatalf("MkdirAll %q (second time): %s", path, err)
}
// Make file.
fpath := path + "/file"
f, err := Create(fpath)
if err != nil {
t.Fatalf("create %q: %s", fpath, err)
}
defer f.Close()
// Can't make directory named after file.
err = MkdirAll(fpath, 0777)
if err == nil {
t.Fatalf("MkdirAll %q: no error", fpath)
}
perr, ok := err.(*PathError)
if !ok {
t.Fatalf("MkdirAll %q returned %T, not *PathError", fpath, err)
}
if filepath.Clean(perr.Path) != filepath.Clean(fpath) {
t.Fatalf("MkdirAll %q returned wrong error path: %q not %q", fpath, filepath.Clean(perr.Path), filepath.Clean(fpath))
}
// Can't make subdirectory of file.
ffpath := fpath + "/subdir"
err = MkdirAll(ffpath, 0777)
if err == nil {
t.Fatalf("MkdirAll %q: no error", ffpath)
}
perr, ok = err.(*PathError)
if !ok {
t.Fatalf("MkdirAll %q returned %T, not *PathError", ffpath, err)
}
if filepath.Clean(perr.Path) != filepath.Clean(fpath) {
t.Fatalf("MkdirAll %q returned wrong error path: %q not %q", ffpath, filepath.Clean(perr.Path), filepath.Clean(fpath))
}
if runtime.GOOS == "windows" {
path := tmpDir + `\_TestMkdirAll_\dir\.\dir2\`
err := MkdirAll(path, 0777)
if err != nil {
t.Fatalf("MkdirAll %q: %s", path, err)
}
}
}
func TestRemoveAll(t *testing.T) {
tmpDir := TempDir()
// Work directory.
path := tmpDir + "/_TestRemoveAll_"
fpath := path + "/file"
dpath := path + "/dir"
// Make directory with 1 file and remove.
if err := MkdirAll(path, 0777); err != nil {
t.Fatalf("MkdirAll %q: %s", path, err)
}
fd, err := Create(fpath)
if err != nil {
t.Fatalf("create %q: %s", fpath, err)
}
fd.Close()
if err = RemoveAll(path); err != nil {
t.Fatalf("RemoveAll %q (first): %s", path, err)
}
if _, err = Lstat(path); err == nil {
t.Fatalf("Lstat %q succeeded after RemoveAll (first)", path)
}
// Make directory with file and subdirectory and remove.
if err = MkdirAll(dpath, 0777); err != nil {
t.Fatalf("MkdirAll %q: %s", dpath, err)
}
fd, err = Create(fpath)
if err != nil {
t.Fatalf("create %q: %s", fpath, err)
}
fd.Close()
fd, err = Create(dpath + "/file")
if err != nil {
t.Fatalf("create %q: %s", fpath, err)
}
fd.Close()
if err = RemoveAll(path); err != nil {
t.Fatalf("RemoveAll %q (second): %s", path, err)
}
if _, err := Lstat(path); err == nil {
t.Fatalf("Lstat %q succeeded after RemoveAll (second)", path)
}
// Determine if we should run the following test.
testit := true
if runtime.GOOS == "windows" {
// Chmod is not supported under windows.
testit = false
} else {
// Test fails as root.
testit = Getuid() != 0
}
if testit {
// Make directory with file and subdirectory and trigger error.
if err = MkdirAll(dpath, 0777); err != nil {
t.Fatalf("MkdirAll %q: %s", dpath, err)
}
for _, s := range []string{fpath, dpath + "/file1", path + "/zzz"} {
fd, err = Create(s)
if err != nil {
t.Fatalf("create %q: %s", s, err)
}
fd.Close()
}
if err = Chmod(dpath, 0); err != nil {
t.Fatalf("Chmod %q 0: %s", dpath, err)
}
// No error checking here: either RemoveAll
// will or won't be able to remove dpath;
// either way we want to see if it removes fpath
// and path/zzz. Reasons why RemoveAll might
// succeed in removing dpath as well include:
// * running as root
// * running on a file system without permissions (FAT)
RemoveAll(path)
Chmod(dpath, 0777)
for _, s := range []string{fpath, path + "/zzz"} {
if _, err = Lstat(s); err == nil {
t.Fatalf("Lstat %q succeeded after partial RemoveAll", s)
}
}
}
if err = RemoveAll(path); err != nil {
t.Fatalf("RemoveAll %q after partial RemoveAll: %s", path, err)
}
if _, err = Lstat(path); err == nil {
t.Fatalf("Lstat %q succeeded after RemoveAll (final)", path)
}
}
// Test RemoveAll on a large directory.
func TestRemoveAllLarge(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
tmpDir := TempDir()
// Work directory.
path := tmpDir + "/_TestRemoveAllLarge_"
// Make directory with 1000 files and remove.
if err := MkdirAll(path, 0777); err != nil {
t.Fatalf("MkdirAll %q: %s", path, err)
}
for i := 0; i < 1000; i++ {
fpath := fmt.Sprintf("%s/file%d", path, i)
fd, err := Create(fpath)
if err != nil {
t.Fatalf("create %q: %s", fpath, err)
}
fd.Close()
}
if err := RemoveAll(path); err != nil {
t.Fatalf("RemoveAll %q: %s", path, err)
}
if _, err := Lstat(path); err == nil {
t.Fatalf("Lstat %q succeeded after RemoveAll", path)
}
}
func TestMkdirAllWithSymlink(t *testing.T) {
testenv.MustHaveSymlink(t)
tmpDir, err := ioutil.TempDir("", "TestMkdirAllWithSymlink-")
if err != nil {
t.Fatal(err)
}
defer RemoveAll(tmpDir)
dir := tmpDir + "/dir"
err = Mkdir(dir, 0755)
if err != nil {
t.Fatalf("Mkdir %s: %s", dir, err)
}
link := tmpDir + "/link"
err = Symlink("dir", link)
if err != nil {
t.Fatalf("Symlink %s: %s", link, err)
}
path := link + "/foo"
err = MkdirAll(path, 0755)
if err != nil {
t.Errorf("MkdirAll %q: %s", path, err)
}
}
func TestMkdirAllAtSlash(t *testing.T) {
switch runtime.GOOS {
case "android", "plan9", "windows":
t.Skipf("skipping on %s", runtime.GOOS)
case "darwin":
switch runtime.GOARCH {
case "arm", "arm64":
t.Skipf("skipping on darwin/%s, mkdir returns EPERM", runtime.GOARCH)
}
}
RemoveAll("/_go_os_test")
const dir = "/_go_os_test/dir"
err := MkdirAll(dir, 0777)
if err != nil {
pathErr, ok := err.(*PathError)
// common for users not to be able to write to /
if ok && (pathErr.Err == syscall.EACCES || isReadonlyError(pathErr.Err)) {
t.Skipf("could not create %v: %v", dir, err)
}
t.Fatalf(`MkdirAll "/_go_os_test/dir": %v, %s`, err, pathErr.Err)
}
RemoveAll("/_go_os_test")
}