run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "errors"
  25         "flag"
  26         "fmt"
  27         "io"
  28         "log"
  29         "os"
  30         "os/exec"
  31         "path"
  32         "path/filepath"
  33         "strconv"
  34         "strings"
  35         "sync"
  36         "syscall"
  37         "time"
  38
  39         "go.cypherpunks.ru/recfile"
  40         "go.cypherpunks.ru/tai64n/v2"
  41         "golang.org/x/sys/unix"
  42 )
  43
  44 const (
  45         EnvDepFd        = "REDO_DEP_FD"
  46         EnvDirPrefix    = "REDO_DIRPREFIX"
  47         EnvDepCwd       = "REDO_DEP_CWD"
  48         EnvBuildUUID    = "REDO_BUILD_UUID"
  49         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  50         EnvTrace        = "REDO_TRACE"
  51         EnvStderrKeep   = "REDO_LOGS"
  52         EnvStderrSilent = "REDO_SILENT"
  53         EnvNoSync       = "REDO_NO_SYNC"
  54
  55         RedoDir    = ".redo"
  56         LockSuffix = ".lock"
  57         DepSuffix  = ".rec"
  58         TmpPrefix  = ".redo."
  59         LogSuffix  = ".log"
  60 )
  61
  62 var (
  63         NoSync       bool = false
  64         StderrKeep   bool = false
  65         StderrSilent bool = false
  66         StderrPrefix string
  67         Jobs         sync.WaitGroup
  68
  69         flagTrace        *bool
  70         flagTraceAll     *bool
  71         flagStderrKeep   *bool
  72         flagStderrSilent *bool
  73
  74         TracedAll bool
  75 )
  76
  77 func init() {
  78         cmdName := CmdName()
  79         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  80                 return
  81         }
  82         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  83         flagTraceAll = flag.Bool("xx", false,
  84                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  85         flagStderrKeep = flag.Bool("k", false,
  86                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  87         flagStderrSilent = flag.Bool("s", false,
  88                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
  89 }
  90
  91 type RunErr struct {
  92         Tgt      string
  93         DoFile   string
  94         Started  *time.Time
  95         Finished *time.Time
  96         Err      error
  97 }
  98
  99 func (e *RunErr) Name() string {
 100         var name string
 101         if e.DoFile == "" {
 102                 name = e.Tgt
 103         } else {
 104                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 105         }
 106         if e.Finished == nil {
 107                 return name
 108         }
 109         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 110 }
 111
 112 func (e RunErr) Error() string {
 113         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 114 }
 115
 116 func mkdirs(pth string) error {
 117         if _, err := os.Stat(pth); err == nil {
 118                 return nil
 119         }
 120         return os.MkdirAll(pth, os.FileMode(0777))
 121 }
 122
 123 func isModified(cwd, redoDir, tgt string) (bool, *Inode, error) {
 124         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 125         if err != nil {
 126                 if os.IsNotExist(err) {
 127                         return false, nil, nil
 128                 }
 129                 return false, nil, err
 130         }
 131         defer fdDep.Close()
 132         r := recfile.NewReader(fdDep)
 133         var ourInode *Inode
 134         for {
 135                 m, err := r.NextMap()
 136                 if err != nil {
 137                         if err == io.EOF {
 138                                 break
 139                         }
 140                         return false, nil, err
 141                 }
 142                 if m["Target"] != tgt {
 143                         continue
 144                 }
 145                 fd, err := os.Open(path.Join(cwd, tgt))
 146                 if err != nil {
 147                         if os.IsNotExist(err) {
 148                                 return false, nil, nil
 149                         }
 150                         return false, nil, err
 151                 }
 152                 ourInode, err = inodeFromFile(fd)
 153                 fd.Close()
 154                 if err != nil {
 155                         return false, nil, err
 156                 }
 157                 theirInode, err := inodeFromRec(m)
 158                 if err != nil {
 159                         return false, nil, err
 160                 }
 161                 if !ourInode.Equals(theirInode) {
 162                         return true, ourInode, nil
 163                 }
 164                 break
 165         }
 166         return false, ourInode, nil
 167 }
 168
 169 func syncDir(dir string) error {
 170         fd, err := os.Open(dir)
 171         if err != nil {
 172                 return err
 173         }
 174         err = fd.Sync()
 175         fd.Close()
 176         return err
 177 }
 178
 179 func runScript(tgtOrig string, errs chan error, traced bool) error {
 180         cwd, tgt := cwdAndTgt(tgtOrig)
 181         redoDir := path.Join(cwd, RedoDir)
 182         if err := mkdirs(redoDir); err != nil {
 183                 return TgtErr{tgtOrig, err}
 184         }
 185
 186         // Acquire lock
 187         fdLock, err := os.OpenFile(
 188                 path.Join(redoDir, tgt+LockSuffix),
 189                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 190                 os.FileMode(0666),
 191         )
 192         if err != nil {
 193                 return TgtErr{tgtOrig, err}
 194         }
 195         lockRelease := func() {
 196                 trace(CLock, "LOCK_UN: %s", fdLock.Name())
 197                 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
 198                 fdLock.Close()
 199         }
 200         trace(CLock, "LOCK_NB: %s", fdLock.Name())
 201
 202         // Waiting for job completion, already taken by someone else
 203         if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
 204                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
 205                         fdLock.Close()
 206                         return TgtErr{tgtOrig, err}
 207                 }
 208                 Jobs.Add(1)
 209                 trace(CDebug, "waiting: %s", tgtOrig)
 210                 if FdStatus != nil {
 211                         FdStatus.Write([]byte{StatusWait})
 212                 }
 213                 go func() {
 214                         defer Jobs.Done()
 215                         trace(CLock, "LOCK_EX: %s", fdLock.Name())
 216                         unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
 217                         lockRelease()
 218                         trace(CDebug, "waiting done: %s", tgtOrig)
 219                         if FdStatus != nil {
 220                                 FdStatus.Write([]byte{StatusWaited})
 221                         }
 222                         var depInfo *DepInfo
 223                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 224                         if err != nil {
 225                                 if os.IsNotExist(err) {
 226                                         err = errors.New("was not built: no .rec")
 227                                 }
 228                                 goto Finish
 229                         }
 230                         defer fdDep.Close()
 231                         depInfo, err = depRead(fdDep)
 232                         if err != nil {
 233                                 goto Finish
 234                         }
 235                         if depInfo.build != BuildUUID {
 236                                 err = errors.New("was not built: build differs")
 237                         }
 238                 Finish:
 239                         if err != nil {
 240                                 err = TgtErr{tgtOrig, err}
 241                         }
 242                         errs <- err
 243                 }()
 244                 return nil
 245         }
 246
 247         // Check if target is not modified externally
 248         modified, inodePrev, err := isModified(cwd, redoDir, tgt)
 249         if err != nil {
 250                 lockRelease()
 251                 return TgtErr{tgtOrig, err}
 252         }
 253         if modified {
 254                 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
 255                 lockRelease()
 256                 go func() {
 257                         errs <- nil
 258                 }()
 259                 return nil
 260         }
 261
 262         // Start preparing .rec
 263         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 264         if err != nil {
 265                 lockRelease()
 266                 return TgtErr{tgtOrig, err}
 267         }
 268         fdDepPath := fdDep.Name()
 269         cleanup := func() {
 270                 lockRelease()
 271                 fdDep.Close()
 272                 os.Remove(fdDep.Name())
 273         }
 274         if _, err = recfile.NewWriter(fdDep).WriteFields(
 275                 recfile.Field{Name: "Build", Value: BuildUUID},
 276         ); err != nil {
 277                 cleanup()
 278                 return TgtErr{tgtOrig, err}
 279         }
 280
 281         // Find .do
 282         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 283         if err != nil {
 284                 cleanup()
 285                 return TgtErr{tgtOrig, err}
 286         }
 287         if doFile == "" {
 288                 cleanup()
 289                 return TgtErr{tgtOrig, errors.New("no .do found")}
 290         }
 291
 292         // Determine basename and DIRPREFIX
 293         doFileRelPath := doFile
 294         ents := strings.Split(cwd, "/")
 295         ents = ents[len(ents)-upLevels:]
 296         dirPrefix := path.Join(ents...)
 297         cwdOrig := cwd
 298         for i := 0; i < upLevels; i++ {
 299                 cwd = path.Join(cwd, "..")
 300                 doFileRelPath = path.Join("..", doFileRelPath)
 301         }
 302         cwd = path.Clean(cwd)
 303         doFilePath := path.Join(cwd, doFile)
 304         basename := tgt
 305         runErr := RunErr{Tgt: tgtOrig}
 306         if strings.HasPrefix(doFile, "default.") {
 307                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 308                 runErr.DoFile = doFileRelPath
 309         }
 310
 311         if err = writeDep(fdDep, cwdOrig, doFileRelPath); err != nil {
 312                 cleanup()
 313                 return TgtErr{tgtOrig, err}
 314         }
 315         fdDep.Close()
 316         trace(CWait, "%s", runErr.Name())
 317
 318         // Prepare command line
 319         var cmdName string
 320         var args []string
 321         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 322                 cmdName = doFilePath
 323                 args = make([]string, 0, 3)
 324         } else {
 325                 cmdName = "/bin/sh"
 326                 if traced || TracedAll {
 327                         args = append(args, "-ex")
 328                 } else {
 329                         args = append(args, "-e")
 330                 }
 331                 args = append(args, doFile)
 332         }
 333
 334         // Temporary file for stdout
 335         fdStdout, err := tempfile(cwdOrig, tgt)
 336         if err != nil {
 337                 cleanup()
 338                 return TgtErr{tgtOrig, err}
 339         }
 340         stdoutPath := fdStdout.Name()
 341         fdStdout.Close()
 342         tmpPath := stdoutPath + ".3" // and for $3
 343         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 344         if err != nil {
 345                 panic(err)
 346         }
 347         args = append(
 348                 args,
 349                 path.Join(dirPrefix, tgt),
 350                 path.Join(dirPrefix, basename),
 351                 tmpPathRel,
 352         )
 353
 354         cmd := exec.Command(cmdName, args...)
 355         cmd.Dir = cwd
 356         // cmd.Stdin reads from /dev/null by default
 357         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 358         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 359         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 360
 361         childStderrPrefix := tempsuffix()
 362         cmd.Env = append(cmd.Env, fmt.Sprintf(
 363                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 364         ))
 365
 366         fdNum := 0
 367         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 368         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 369         fdNum++
 370         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 371         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 372         fdNum++
 373
 374         if FdStatus == nil {
 375                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 376         } else {
 377                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 378                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 379                 fdNum++
 380         }
 381
 382         // Preparing stderr
 383         var fdStderr *os.File
 384         if StderrKeep {
 385                 fdStderr, err = os.OpenFile(
 386                         path.Join(redoDir, tgt+LogSuffix),
 387                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 388                         os.FileMode(0666),
 389                 )
 390                 if err != nil {
 391                         cleanup()
 392                         return TgtErr{tgtOrig, err}
 393                 }
 394         }
 395         shCtx := fmt.Sprintf(
 396                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 397                 tgtOrig, cmdName, args, cwd, dirPrefix,
 398         )
 399         trace(CDebug, "%s", shCtx)
 400
 401         Jobs.Add(1)
 402         go func() {
 403                 jsToken := jsAcquire(shCtx)
 404                 if JSR == nil {
 405                         // infinite jobs
 406                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 407                 } else {
 408                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 409                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 410                         cmd.Env = append(cmd.Env, fmt.Sprintf(
 411                                 "%s=%s %s%d,%d",
 412                                 MakeFlagsName, MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 413                         ))
 414                         fdNum += 2
 415                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 416                 }
 417
 418                 if FdStatus != nil {
 419                         FdStatus.Write([]byte{StatusRun})
 420                 }
 421
 422                 var finished time.Time
 423                 var exitErr *exec.ExitError
 424                 started := time.Now()
 425                 runErr.Started = &started
 426                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 427                 if err != nil {
 428                         runErr.Err = err
 429                         errs <- runErr
 430                         return
 431                 }
 432                 cmd.Stdout = fdStdout
 433                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 434                 if err != nil {
 435                         runErr.Err = err
 436                         errs <- runErr
 437                         return
 438                 }
 439                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 440                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 441                 fdNum++
 442                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 443
 444                 defer func() {
 445                         jsRelease(shCtx, jsToken)
 446                         fdDep.Close()
 447                         fdStdout.Close()
 448                         if fdStderr != nil {
 449                                 fdStderr.Close()
 450                                 logRecPath := path.Join(redoDir, tgt+LogSuffix+DepSuffix)
 451                                 if fdStderr, err = os.OpenFile(
 452                                         logRecPath,
 453                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 454                                         os.FileMode(0666),
 455                                 ); err == nil {
 456                                         fields := []recfile.Field{
 457                                                 {Name: "Build", Value: BuildUUID},
 458                                                 {Name: "PID", Value: strconv.Itoa(cmd.Process.Pid)},
 459                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 460                                                 {Name: "Cwd", Value: cwd},
 461                                         }
 462                                         ts := new(tai64n.TAI64N)
 463                                         ts.FromTime(started)
 464                                         fields = append(fields,
 465                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 466                                         )
 467                                         ts.FromTime(finished)
 468                                         fields = append(fields,
 469                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 470                                         fields = append(fields, recfile.Field{
 471                                                 Name:  "Duration",
 472                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 473                                         })
 474                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 475                                         for _, arg := range args {
 476                                                 fields = append(fields, recfile.Field{Name: "Cmd", Value: arg})
 477                                         }
 478                                         for _, env := range cmd.Env {
 479                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 480                                         }
 481                                         if exitErr != nil {
 482                                                 fields = append(fields, recfile.Field{
 483                                                         Name:  "ExitCode",
 484                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 485                                                 })
 486                                         }
 487                                         w := bufio.NewWriter(fdStderr)
 488
 489                                         var depInfo *DepInfo
 490                                         fdDep, err := os.Open(fdDepPath)
 491                                         if err != nil {
 492                                                 goto Err
 493                                         }
 494                                         depInfo, err = depRead(fdDep)
 495                                         fdDep.Close()
 496                                         if err != nil {
 497                                                 goto Err
 498                                         }
 499                                         for _, dep := range depInfo.ifchanges {
 500                                                 fields = append(fields, recfile.Field{
 501                                                         Name:  "Ifchange",
 502                                                         Value: dep["Target"],
 503                                                 })
 504                                         }
 505                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 506                                         if err != nil {
 507                                                 goto Err
 508                                         }
 509                                         err = w.Flush()
 510                                 Err:
 511                                         if err != nil {
 512                                                 log.Println(err)
 513                                                 os.Remove(logRecPath)
 514                                         }
 515                                         fdStderr.Close()
 516                                 } else {
 517                                         log.Println("can not open", logRecPath, ":", err)
 518                                 }
 519                         }
 520                         lockRelease()
 521                         os.Remove(fdDep.Name())
 522                         os.Remove(fdStdout.Name())
 523                         os.Remove(tmpPath)
 524                         os.Remove(fdLock.Name())
 525                         if FdStatus != nil {
 526                                 FdStatus.Write([]byte{StatusDone})
 527                         }
 528                         Jobs.Done()
 529                 }()
 530                 stderr, err := cmd.StderrPipe()
 531                 if err != nil {
 532                         runErr.Err = err
 533                         errs <- runErr
 534                         return
 535                 }
 536                 started = time.Now()
 537                 err = cmd.Start()
 538                 if err != nil {
 539                         runErr.Err = err
 540                         errs <- runErr
 541                         return
 542                 }
 543                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 544                 trace(CDebug, "%s runs %s", tgtOrig, pid)
 545
 546                 stderrTerm := make(chan struct{}, 0)
 547                 go func() {
 548                         scanner := bufio.NewScanner(stderr)
 549                         var line string
 550                         ts := new(tai64n.TAI64N)
 551                         for scanner.Scan() {
 552                                 line = scanner.Text()
 553                                 if strings.HasPrefix(line, childStderrPrefix) {
 554                                         line = line[len(childStderrPrefix):]
 555                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 556                                         continue
 557                                 }
 558                                 if fdStderr != nil {
 559                                         ts.FromTime(time.Now())
 560                                         LogMutex.Lock()
 561                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 562                                         LogMutex.Unlock()
 563                                 }
 564                                 if StderrSilent {
 565                                         continue
 566                                 }
 567                                 if MyPid == 0 {
 568                                         trace(CNone, "%s", line)
 569                                 } else {
 570                                         trace(CNone, "%s %s", pid, line)
 571                                 }
 572                         }
 573                         close(stderrTerm)
 574                 }()
 575
 576                 // Wait for job completion
 577                 <-stderrTerm
 578                 err = cmd.Wait()
 579                 finished = time.Now()
 580                 runErr.Finished = &finished
 581                 if err != nil {
 582                         exitErr = err.(*exec.ExitError)
 583                         runErr.Err = err
 584                         errs <- runErr
 585                         return
 586                 }
 587
 588                 // Was $1 touched?
 589                 if inodePrev != nil {
 590                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 591                                 inode, err := inodeFromFile(fd)
 592                                 fd.Close()
 593                                 if err == nil && !inode.Equals(inodePrev) {
 594                                         runErr.Err = errors.New("$1 was explicitly touched")
 595                                         errs <- runErr
 596                                         return
 597                                 }
 598                         }
 599                 }
 600
 601                 // Does it produce both stdout and tmp?
 602                 fiStdout, err := os.Stat(fdStdout.Name())
 603                 if err != nil {
 604                         runErr.Err = err
 605                         errs <- runErr
 606                         return
 607                 }
 608                 tmpExists := false
 609                 _, err = os.Stat(tmpPath)
 610                 if err == nil {
 611                         if fiStdout.Size() > 0 {
 612                                 runErr.Err = errors.New("created both tmp and stdout")
 613                                 errs <- runErr
 614                                 return
 615                         }
 616                         tmpExists = true
 617                 } else if !os.IsNotExist(err) {
 618                         runErr.Err = err
 619                         errs <- runErr
 620                         return
 621                 }
 622
 623                 // Determine what file we must process at last
 624                 var fd *os.File
 625                 if tmpExists {
 626                         fd, err = os.Open(tmpPath)
 627                         if err != nil {
 628                                 goto Finish
 629                         }
 630                         defer fd.Close()
 631                 } else if fiStdout.Size() > 0 {
 632                         fd = fdStdout
 633                 }
 634
 635                 // Do we need to ifcreate it, of ifchange with renaming?
 636                 if fd == nil {
 637                         os.Remove(path.Join(cwdOrig, tgt))
 638                         err = ifcreate(fdDep, tgt)
 639                         if err != nil {
 640                                 goto Finish
 641                         }
 642                 } else {
 643                         if !NoSync {
 644                                 err = fd.Sync()
 645                                 if err != nil {
 646                                         goto Finish
 647                                 }
 648                         }
 649                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 650                         if err != nil {
 651                                 goto Finish
 652                         }
 653                         if !NoSync {
 654                                 err = syncDir(cwdOrig)
 655                                 if err != nil {
 656                                         goto Finish
 657                                 }
 658                         }
 659                         err = writeDep(fdDep, cwdOrig, tgt)
 660                         if err != nil {
 661                                 goto Finish
 662                         }
 663                 }
 664
 665                 // Commit .rec
 666                 if !NoSync {
 667                         err = fdDep.Sync()
 668                         if err != nil {
 669                                 goto Finish
 670                         }
 671                 }
 672                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 673                 err = os.Rename(fdDep.Name(), fdDepPath)
 674                 if err != nil {
 675                         goto Finish
 676                 }
 677                 if !NoSync {
 678                         err = syncDir(redoDir)
 679                         if err != nil {
 680                                 goto Finish
 681                         }
 682                 }
 683         Finish:
 684                 runErr.Err = err
 685                 errs <- runErr
 686         }()
 687         return nil
 688 }
 689
 690 func isOkRun(err error) bool {
 691         if err == nil {
 692                 return true
 693         }
 694         if err, ok := err.(RunErr); ok && err.Err == nil {
 695                 trace(CRedo, "%s", err.Name())
 696                 return true
 697         }
 698         trace(CErr, "%s", err)
 699         return false
 700 }