Implement facility based logger, debugging via REST API

This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
2015-10-03 17:25:21 +02:00
parent 2de364414f
commit 76af9ba53d
62 changed files with 796 additions and 1383 deletions
--- a/lib/model/debug.go
+++ b/lib/model/debug.go
@@ -10,10 +10,17 @@ import (
 	"os"
 	"strings"

-	"github.com/calmh/logger"
+	"github.com/syncthing/syncthing/lib/logger"
 )

 var (
-	debug = strings.Contains(os.Getenv("STTRACE"), "model") || os.Getenv("STTRACE") == "all"
-	l     = logger.DefaultLogger
+	l = logger.DefaultLogger.NewFacility("model", "The root hub")
 )
+
+func init() {
+	l.SetDebug("model", strings.Contains(os.Getenv("STTRACE"), "model") || os.Getenv("STTRACE") == "all")
+}
+
+func shouldDebug() bool {
+	return l.ShouldDebug("model")
+}
--- a/lib/model/model.go
+++ b/lib/model/model.go
@@ -107,9 +107,7 @@ func NewModel(cfg *config.Wrapper, id protocol.DeviceID, deviceName, clientName,
 	m := &Model{
 		Supervisor: suture.New("model", suture.Spec{
 			Log: func(line string) {
-				if debug {
-					l.Debugln(line)
-				}
+				l.Debugln(line)
 			},
 		}),
 		cfg:                cfg,
@@ -335,9 +333,7 @@ func (m *Model) Completion(device protocol.DeviceID, folder string) float64 {
 	})

 	res := 100 * (1 - float64(need)/float64(tot))
-	if debug {
-		l.Debugf("%v Completion(%s, %q): %f (%d / %d)", m, device, folder, res, need, tot)
-	}
+	l.Debugf("%v Completion(%s, %q): %f (%d / %d)", m, device, folder, res, need, tot)

 	return res
 }
@@ -412,9 +408,7 @@ func (m *Model) NeedSize(folder string) (nfiles int, bytes int64) {
 		})
 	}
 	bytes -= m.progressEmitter.BytesCompleted(folder)
-	if debug {
-		l.Debugf("%v NeedSize(%q): %d %d", m, folder, nfiles, bytes)
-	}
+	l.Debugf("%v NeedSize(%q): %d %d", m, folder, nfiles, bytes)
 	return
 }

@@ -493,9 +487,7 @@ func (m *Model) Index(deviceID protocol.DeviceID, folder string, fs []protocol.F
 		return
 	}

-	if debug {
-		l.Debugf("IDX(in): %s %q: %d files", deviceID, folder, len(fs))
-	}
+	l.Debugf("IDX(in): %s %q: %d files", deviceID, folder, len(fs))

 	if !m.folderSharedWith(folder, deviceID) {
 		events.Default.Log(events.FolderRejected, map[string]string{
@@ -541,9 +533,7 @@ func (m *Model) IndexUpdate(deviceID protocol.DeviceID, folder string, fs []prot
 		return
 	}

-	if debug {
-		l.Debugf("%v IDXUP(in): %s / %q: %d files", m, deviceID, folder, len(fs))
-	}
+	l.Debugf("%v IDXUP(in): %s / %q: %d files", m, deviceID, folder, len(fs))

 	if !m.folderSharedWith(folder, deviceID) {
 		l.Infof("Update for unexpected folder ID %q sent from device %q; ensure that the folder exists and that this device is selected under \"Share With\" in the folder configuration.", folder, deviceID)
@@ -766,16 +756,12 @@ func (m *Model) Request(deviceID protocol.DeviceID, folder, name string, offset
 		}

 		if lf.IsInvalid() || lf.IsDeleted() {
-			if debug {
-				l.Debugf("%v REQ(in): %s: %q / %q o=%d s=%d; invalid: %v", m, deviceID, folder, name, offset, len(buf), lf)
-			}
+			l.Debugf("%v REQ(in): %s: %q / %q o=%d s=%d; invalid: %v", m, deviceID, folder, name, offset, len(buf), lf)
 			return protocol.ErrInvalid
 		}

 		if offset > lf.Size() {
-			if debug {
-				l.Debugf("%v REQ(in; nonexistent): %s: %q o=%d s=%d", m, deviceID, name, offset, len(buf))
-			}
+			l.Debugf("%v REQ(in; nonexistent): %s: %q o=%d s=%d", m, deviceID, name, offset, len(buf))
 			return protocol.ErrNoSuchFile
 		}

@@ -806,7 +792,7 @@ func (m *Model) Request(deviceID protocol.DeviceID, folder, name string, offset
 		m.rvmut.Unlock()
 	}

-	if debug && deviceID != protocol.LocalDeviceID {
+	if deviceID != protocol.LocalDeviceID {
 		l.Debugf("%v REQ(in): %s: %q / %q o=%d s=%d", m, deviceID, folder, name, offset, len(buf))
 	}
 	m.fmut.RLock()
@@ -1033,9 +1019,8 @@ func sendIndexes(conn protocol.Connection, folder string, fs *db.FileSet, ignore
 	name := conn.Name()
 	var err error

-	if debug {
-		l.Debugf("sendIndexes for %s-%s/%q starting", deviceID, name, folder)
-	}
+	l.Debugf("sendIndexes for %s-%s/%q starting", deviceID, name, folder)
+	defer l.Debugf("sendIndexes for %s-%s/%q exiting: %v", deviceID, name, folder, err)

 	minLocalVer, err := sendIndexTo(true, 0, conn, folder, fs, ignores)

@@ -1060,9 +1045,6 @@ func sendIndexes(conn protocol.Connection, folder string, fs *db.FileSet, ignore
 		time.Sleep(250 * time.Millisecond)
 	}

-	if debug {
-		l.Debugf("sendIndexes for %s-%s/%q exiting: %v", deviceID, name, folder, err)
-	}
 }

 func sendIndexTo(initial bool, minLocalVer int64, conn protocol.Connection, folder string, fs *db.FileSet, ignores *ignore.Matcher) (int64, error) {
@@ -1084,9 +1066,7 @@ func sendIndexTo(initial bool, minLocalVer int64, conn protocol.Connection, fold
 		}

 		if ignores.Match(f.Name) || symlinkInvalid(folder, f) {
-			if debug {
-				l.Debugln("not sending update for ignored/unsupported symlink", f)
-			}
+			l.Debugln("not sending update for ignored/unsupported symlink", f)
 			return true
 		}

@@ -1095,17 +1075,13 @@ func sendIndexTo(initial bool, minLocalVer int64, conn protocol.Connection, fold
 				if err = conn.Index(folder, batch, 0, nil); err != nil {
 					return false
 				}
-				if debug {
-					l.Debugf("sendIndexes for %s-%s/%q: %d files (<%d bytes) (initial index)", deviceID, name, folder, len(batch), currentBatchSize)
-				}
+				l.Debugf("sendIndexes for %s-%s/%q: %d files (<%d bytes) (initial index)", deviceID, name, folder, len(batch), currentBatchSize)
 				initial = false
 			} else {
 				if err = conn.IndexUpdate(folder, batch, 0, nil); err != nil {
 					return false
 				}
-				if debug {
-					l.Debugf("sendIndexes for %s-%s/%q: %d files (<%d bytes) (batched update)", deviceID, name, folder, len(batch), currentBatchSize)
-				}
+				l.Debugf("sendIndexes for %s-%s/%q: %d files (<%d bytes) (batched update)", deviceID, name, folder, len(batch), currentBatchSize)
 			}

 			batch = make([]protocol.FileInfo, 0, indexBatchSize)
@@ -1119,12 +1095,12 @@ func sendIndexTo(initial bool, minLocalVer int64, conn protocol.Connection, fold

 	if initial && err == nil {
 		err = conn.Index(folder, batch, 0, nil)
-		if debug && err == nil {
+		if err == nil {
 			l.Debugf("sendIndexes for %s-%s/%q: %d files (small initial index)", deviceID, name, folder, len(batch))
 		}
 	} else if len(batch) > 0 && err == nil {
 		err = conn.IndexUpdate(folder, batch, 0, nil)
-		if debug && err == nil {
+		if err == nil {
 			l.Debugf("sendIndexes for %s-%s/%q: %d files (last batch)", deviceID, name, folder, len(batch))
 		}
 	}
@@ -1160,9 +1136,7 @@ func (m *Model) requestGlobal(deviceID protocol.DeviceID, folder, name string, o
 		return nil, fmt.Errorf("requestGlobal: no such device: %s", deviceID)
 	}

-	if debug {
-		l.Debugf("%v REQ(out): %s: %q / %q o=%d s=%d h=%x f=%x op=%s", m, deviceID, folder, name, offset, size, hash, flags, options)
-	}
+	l.Debugf("%v REQ(out): %s: %q / %q o=%d s=%d h=%x f=%x op=%s", m, deviceID, folder, name, offset, size, hash, flags, options)

 	return nc.Request(folder, name, offset, size, hash, flags, options)
 }
@@ -1403,9 +1377,7 @@ nextSub:

 			if ignores.Match(f.Name) || symlinkInvalid(folder, f) {
 				// File has been ignored or an unsupported symlink. Set invalid bit.
-				if debug {
-					l.Debugln("setting invalid bit on ignored", f)
-				}
+				l.Debugln("setting invalid bit on ignored", f)
 				nf := protocol.FileInfo{
 					Name:     f.Name,
 					Flags:    f.Flags | protocol.FlagInvalid,
@@ -1820,9 +1792,7 @@ func (m *Model) CommitConfiguration(from, to config.Configuration) bool {
 	for folderID, cfg := range toFolders {
 		if _, ok := fromFolders[folderID]; !ok {
 			// A folder was added.
-			if debug {
-				l.Debugln(m, "adding folder", folderID)
-			}
+			l.Debugln(m, "adding folder", folderID)
 			m.AddFolder(cfg)
 			if cfg.ReadOnly {
 				m.StartFolderRO(folderID)
@@ -1846,9 +1816,7 @@ func (m *Model) CommitConfiguration(from, to config.Configuration) bool {
 		toCfg, ok := toFolders[folderID]
 		if !ok {
 			// A folder was removed. Requires restart.
-			if debug {
-				l.Debugln(m, "requires restart, removing folder", folderID)
-			}
+			l.Debugln(m, "requires restart, removing folder", folderID)
 			return false
 		}

@@ -1860,9 +1828,7 @@ func (m *Model) CommitConfiguration(from, to config.Configuration) bool {
 		for dev := range fromDevs {
 			if _, ok := toDevs[dev]; !ok {
 				// A device was removed. Requires restart.
-				if debug {
-					l.Debugln(m, "requires restart, removing device", dev, "from folder", folderID)
-				}
+				l.Debugln(m, "requires restart, removing device", dev, "from folder", folderID)
 				return false
 			}
 		}
@@ -1895,9 +1861,7 @@ func (m *Model) CommitConfiguration(from, to config.Configuration) bool {
 		fromCfg.Devices = nil
 		toCfg.Devices = nil
 		if !reflect.DeepEqual(fromCfg, toCfg) {
-			if debug {
-				l.Debugln(m, "requires restart, folder", folderID, "configuration differs")
-			}
+			l.Debugln(m, "requires restart, folder", folderID, "configuration differs")
 			return false
 		}
 	}
@@ -1906,18 +1870,14 @@ func (m *Model) CommitConfiguration(from, to config.Configuration) bool {
 	toDevs := mapDeviceCfgs(from.Devices)
 	for _, dev := range from.Devices {
 		if _, ok := toDevs[dev.DeviceID]; !ok {
-			if debug {
-				l.Debugln(m, "requires restart, device", dev.DeviceID, "was removed")
-			}
+			l.Debugln(m, "requires restart, device", dev.DeviceID, "was removed")
 			return false
 		}
 	}

 	// All of the generic options require restart
 	if !reflect.DeepEqual(from.Options, to.Options) {
-		if debug {
-			l.Debugln(m, "requires restart, options differ")
-		}
+		l.Debugln(m, "requires restart, options differ")
 		return false
 	}

@@ -1957,21 +1917,15 @@ func mapDeviceCfgs(devices []config.DeviceConfiguration) map[protocol.DeviceID]s
 func filterIndex(folder string, fs []protocol.FileInfo, dropDeletes bool) []protocol.FileInfo {
 	for i := 0; i < len(fs); {
 		if fs[i].Flags&^protocol.FlagsAll != 0 {
-			if debug {
-				l.Debugln("dropping update for file with unknown bits set", fs[i])
-			}
+			l.Debugln("dropping update for file with unknown bits set", fs[i])
 			fs[i] = fs[len(fs)-1]
 			fs = fs[:len(fs)-1]
 		} else if fs[i].IsDeleted() && dropDeletes {
-			if debug {
-				l.Debugln("dropping update for undesired delete", fs[i])
-			}
+			l.Debugln("dropping update for undesired delete", fs[i])
 			fs[i] = fs[len(fs)-1]
 			fs = fs[:len(fs)-1]
 		} else if symlinkInvalid(folder, fs[i]) {
-			if debug {
-				l.Debugln("dropping update for unsupported symlink", fs[i])
-			}
+			l.Debugln("dropping update for unsupported symlink", fs[i])
 			fs[i] = fs[len(fs)-1]
 			fs = fs[:len(fs)-1]
 		} else {
--- a/lib/model/progressemitter.go
+++ b/lib/model/progressemitter.go
@@ -51,15 +51,11 @@ func (t *ProgressEmitter) Serve() {
 	for {
 		select {
 		case <-t.stop:
-			if debug {
-				l.Debugln("progress emitter: stopping")
-			}
+			l.Debugln("progress emitter: stopping")
 			return
 		case <-t.timer.C:
 			t.mut.Lock()
-			if debug {
-				l.Debugln("progress emitter: timer - looking after", len(t.registry))
-			}
+			l.Debugln("progress emitter: timer - looking after", len(t.registry))
 			output := make(map[string]map[string]*pullerProgress)
 			for _, puller := range t.registry {
 				if output[puller.folder] == nil {
@@ -70,10 +66,8 @@ func (t *ProgressEmitter) Serve() {
 			if !reflect.DeepEqual(t.last, output) {
 				events.Default.Log(events.DownloadProgress, output)
 				t.last = output
-				if debug {
-					l.Debugf("progress emitter: emitting %#v", output)
-				}
-			} else if debug {
+				l.Debugf("progress emitter: emitting %#v", output)
+			} else {
 				l.Debugln("progress emitter: nothing new")
 			}
 			if len(t.registry) != 0 {
@@ -95,9 +89,7 @@ func (t *ProgressEmitter) CommitConfiguration(from, to config.Configuration) boo
 	defer t.mut.Unlock()

 	t.interval = time.Duration(to.Options.ProgressUpdateIntervalS) * time.Second
-	if debug {
-		l.Debugln("progress emitter: updated interval", t.interval)
-	}
+	l.Debugln("progress emitter: updated interval", t.interval)

 	return true
 }
@@ -112,9 +104,7 @@ func (t *ProgressEmitter) Stop() {
 func (t *ProgressEmitter) Register(s *sharedPullerState) {
 	t.mut.Lock()
 	defer t.mut.Unlock()
-	if debug {
-		l.Debugln("progress emitter: registering", s.folder, s.file.Name)
-	}
+	l.Debugln("progress emitter: registering", s.folder, s.file.Name)
 	if len(t.registry) == 0 {
 		t.timer.Reset(t.interval)
 	}
@@ -125,9 +115,7 @@ func (t *ProgressEmitter) Register(s *sharedPullerState) {
 func (t *ProgressEmitter) Deregister(s *sharedPullerState) {
 	t.mut.Lock()
 	defer t.mut.Unlock()
-	if debug {
-		l.Debugln("progress emitter: deregistering", s.folder, s.file.Name)
-	}
+	l.Debugln("progress emitter: deregistering", s.folder, s.file.Name)
 	delete(t.registry, filepath.Join(s.folder, s.file.Name))
 }

@@ -141,9 +129,7 @@ func (t *ProgressEmitter) BytesCompleted(folder string) (bytes int64) {
 			bytes += s.Progress().BytesDone
 		}
 	}
-	if debug {
-		l.Debugf("progress emitter: bytes completed for %s: %d", folder, bytes)
-	}
+	l.Debugf("progress emitter: bytes completed for %s: %d", folder, bytes)
 	return
 }

--- a/lib/model/rofolder.go
+++ b/lib/model/rofolder.go
@@ -48,10 +48,8 @@ func newROFolder(model *Model, folder string, interval time.Duration) *roFolder
 }

 func (s *roFolder) Serve() {
-	if debug {
-		l.Debugln(s, "starting")
-		defer l.Debugln(s, "exiting")
-	}
+	l.Debugln(s, "starting")
+	defer l.Debugln(s, "exiting")

 	defer func() {
 		s.timer.Stop()
@@ -79,9 +77,7 @@ func (s *roFolder) Serve() {
 				continue
 			}

-			if debug {
-				l.Debugln(s, "rescan")
-			}
+			l.Debugln(s, "rescan")

 			if err := s.model.internalScanFolderSubs(s.folder, nil); err != nil {
 				// Potentially sets the error twice, once in the scanner just
@@ -111,9 +107,7 @@ func (s *roFolder) Serve() {
 				continue
 			}

-			if debug {
-				l.Debugln(s, "forced rescan")
-			}
+			l.Debugln(s, "forced rescan")

 			if err := s.model.internalScanFolderSubs(s.folder, req.subs); err != nil {
 				// Potentially sets the error twice, once in the scanner just
--- a/lib/model/rwfolder.go
+++ b/lib/model/rwfolder.go
@@ -157,10 +157,8 @@ func (p *rwFolder) ignorePermissions(file protocol.FileInfo) bool {
 // Serve will run scans and pulls. It will return when Stop()ed or on a
 // critical error.
 func (p *rwFolder) Serve() {
-	if debug {
-		l.Debugln(p, "starting")
-		defer l.Debugln(p, "exiting")
-	}
+	l.Debugln(p, "starting")
+	defer l.Debugln(p, "exiting")

 	defer func() {
 		p.pullTimer.Stop()
@@ -182,9 +180,7 @@ func (p *rwFolder) Serve() {
 		sleepNanos := (p.scanIntv.Nanoseconds()*3 + rand.Int63n(2*p.scanIntv.Nanoseconds())) / 4
 		intv := time.Duration(sleepNanos) * time.Nanosecond

-		if debug {
-			l.Debugln(p, "next rescan in", intv)
-		}
+		l.Debugln(p, "next rescan in", intv)
 		p.scanTimer.Reset(intv)
 	}

@@ -199,15 +195,11 @@ func (p *rwFolder) Serve() {
 		case <-p.remoteIndex:
 			prevVer = 0
 			p.pullTimer.Reset(shortPullIntv)
-			if debug {
-				l.Debugln(p, "remote index updated, rescheduling pull")
-			}
+			l.Debugln(p, "remote index updated, rescheduling pull")

 		case <-p.pullTimer.C:
 			if !initialScanCompleted {
-				if debug {
-					l.Debugln(p, "skip (initial)")
-				}
+				l.Debugln(p, "skip (initial)")
 				p.pullTimer.Reset(nextPullIntv)
 				continue
 			}
@@ -225,9 +217,7 @@ func (p *rwFolder) Serve() {
 			if newHash := curIgnores.Hash(); newHash != prevIgnoreHash {
 				// The ignore patterns have changed. We need to re-evaluate if
 				// there are files we need now that were ignored before.
-				if debug {
-					l.Debugln(p, "ignore patterns have changed, resetting prevVer")
-				}
+				l.Debugln(p, "ignore patterns have changed, resetting prevVer")
 				prevVer = 0
 				prevIgnoreHash = newHash
 			}
@@ -235,16 +225,12 @@ func (p *rwFolder) Serve() {
 			// RemoteLocalVersion() is a fast call, doesn't touch the database.
 			curVer, ok := p.model.RemoteLocalVersion(p.folder)
 			if !ok || curVer == prevVer {
-				if debug {
-					l.Debugln(p, "skip (curVer == prevVer)", prevVer, ok)
-				}
+				l.Debugln(p, "skip (curVer == prevVer)", prevVer, ok)
 				p.pullTimer.Reset(nextPullIntv)
 				continue
 			}

-			if debug {
-				l.Debugln(p, "pulling", prevVer, curVer)
-			}
+			l.Debugln(p, "pulling", prevVer, curVer)

 			p.setState(FolderSyncing)
 			p.clearErrors()
@@ -254,9 +240,7 @@ func (p *rwFolder) Serve() {
 				tries++

 				changed := p.pullerIteration(curIgnores)
-				if debug {
-					l.Debugln(p, "changed", changed)
-				}
+				l.Debugln(p, "changed", changed)

 				if changed == 0 {
 					// No files were changed by the puller, so we are in
@@ -276,9 +260,7 @@ func (p *rwFolder) Serve() {
 						curVer = lv
 					}
 					prevVer = curVer
-					if debug {
-						l.Debugln(p, "next pull in", nextPullIntv)
-					}
+					l.Debugln(p, "next pull in", nextPullIntv)
 					p.pullTimer.Reset(nextPullIntv)
 					break
 				}
@@ -289,9 +271,7 @@ func (p *rwFolder) Serve() {
 					// errors preventing us. Flag this with a warning and
 					// wait a bit longer before retrying.
 					l.Infof("Folder %q isn't making progress. Pausing puller for %v.", p.folder, pauseIntv)
-					if debug {
-						l.Debugln(p, "next pull in", pauseIntv)
-					}
+					l.Debugln(p, "next pull in", pauseIntv)

 					if folderErrors := p.currentErrors(); len(folderErrors) > 0 {
 						events.Default.Log(events.FolderErrors, map[string]interface{}{
@@ -316,9 +296,7 @@ func (p *rwFolder) Serve() {
 				continue
 			}

-			if debug {
-				l.Debugln(p, "rescan")
-			}
+			l.Debugln(p, "rescan")

 			if err := p.model.internalScanFolderSubs(p.folder, nil); err != nil {
 				// Potentially sets the error twice, once in the scanner just
@@ -345,9 +323,7 @@ func (p *rwFolder) Serve() {
 				continue
 			}

-			if debug {
-				l.Debugln(p, "forced rescan")
-			}
+			l.Debugln(p, "forced rescan")

 			if err := p.model.internalScanFolderSubs(p.folder, req.subs); err != nil {
 				// Potentially sets the error twice, once in the scanner just
@@ -409,9 +385,7 @@ func (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
 	pullWg := sync.NewWaitGroup()
 	doneWg := sync.NewWaitGroup()

-	if debug {
-		l.Debugln(p, "c", p.copiers, "p", p.pullers)
-	}
+	l.Debugln(p, "c", p.copiers, "p", p.pullers)

 	p.dbUpdates = make(chan dbUpdateJob)
 	updateWg.Add(1)
@@ -474,9 +448,7 @@ func (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
 			return true
 		}

-		if debug {
-			l.Debugln(p, "handling", file.Name)
-		}
+		l.Debugln(p, "handling", file.Name)

 		switch {
 		case file.IsDeleted():
@@ -498,9 +470,7 @@ func (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
 			}
 		case file.IsDirectory() && !file.IsSymlink():
 			// A new or changed directory
-			if debug {
-				l.Debugln("Creating directory", file.Name)
-			}
+			l.Debugln("Creating directory", file.Name)
 			p.handleDir(file)
 		default:
 			// A new or changed file or symlink. This is the only case where we
@@ -591,17 +561,13 @@ nextFile:
 	doneWg.Wait()

 	for _, file := range fileDeletions {
-		if debug {
-			l.Debugln("Deleting file", file.Name)
-		}
+		l.Debugln("Deleting file", file.Name)
 		p.deleteFile(file)
 	}

 	for i := range dirDeletions {
 		dir := dirDeletions[len(dirDeletions)-i-1]
-		if debug {
-			l.Debugln("Deleting dir", dir.Name)
-		}
+		l.Debugln("Deleting dir", dir.Name)
 		p.deleteDir(dir)
 	}

@@ -638,7 +604,7 @@ func (p *rwFolder) handleDir(file protocol.FileInfo) {
 		mode = 0777
 	}

-	if debug {
+	if shouldDebug() {
 		curFile, _ := p.model.CurrentFolderFile(p.folder, file.Name)
 		l.Debugf("need dir\n\t%v\n\t%v", file, curFile)
 	}
@@ -836,9 +802,7 @@ func (p *rwFolder) renameFile(source, target protocol.FileInfo) {
 		})
 	}()

-	if debug {
-		l.Debugln(p, "taking rename shortcut", source.Name, "->", target.Name)
-	}
+	l.Debugln(p, "taking rename shortcut", source.Name, "->", target.Name)

 	from := filepath.Join(p.dir, source.Name)
 	to := filepath.Join(p.dir, target.Name)
@@ -926,9 +890,7 @@ func (p *rwFolder) handleFile(file protocol.FileInfo, copyChan chan<- copyBlocks
 		// We are supposed to copy the entire file, and then fetch nothing. We
 		// are only updating metadata, so we don't actually *need* to make the
 		// copy.
-		if debug {
-			l.Debugln(p, "taking shortcut on", file.Name)
-		}
+		l.Debugln(p, "taking shortcut on", file.Name)

 		events.Default.Log(events.ItemStarted, map[string]string{
 			"folder": p.folder,
@@ -1033,9 +995,7 @@ func (p *rwFolder) handleFile(file protocol.FileInfo, copyChan chan<- copyBlocks
 		mut:         sync.NewMutex(),
 	}

-	if debug {
-		l.Debugf("%v need file %s; copy %d, reused %v", p, file.Name, len(blocks), reused)
-	}
+	l.Debugf("%v need file %s; copy %d, reused %v", p, file.Name, len(blocks), reused)

 	cs := copyBlocksState{
 		sharedPullerState: &s,
@@ -1135,14 +1095,12 @@ func (p *rwFolder) copierRoutine(in <-chan copyBlocksState, pullChan chan<- pull
 				hash, err := scanner.VerifyBuffer(buf, block)
 				if err != nil {
 					if hash != nil {
-						if debug {
-							l.Debugf("Finder block mismatch in %s:%s:%d expected %q got %q", folder, file, index, block.Hash, hash)
-						}
+						l.Debugf("Finder block mismatch in %s:%s:%d expected %q got %q", folder, file, index, block.Hash, hash)
 						err = p.model.finder.Fix(folder, file, index, block.Hash, hash)
 						if err != nil {
 							l.Warnln("finder fix:", err)
 						}
-					} else if debug {
+					} else {
 						l.Debugln("Finder failed to verify buffer", err)
 					}
 					return false
@@ -1217,9 +1175,7 @@ func (p *rwFolder) pullerRoutine(in <-chan pullBlockState, out chan<- *sharedPul
 			buf, lastError := p.model.requestGlobal(selected, p.folder, state.file.Name, state.block.Offset, int(state.block.Size), state.block.Hash, 0, nil)
 			activity.done(selected)
 			if lastError != nil {
-				if debug {
-					l.Debugln("request:", p.folder, state.file.Name, state.block.Offset, state.block.Size, "returned error:", lastError)
-				}
+				l.Debugln("request:", p.folder, state.file.Name, state.block.Offset, state.block.Size, "returned error:", lastError)
 				continue
 			}

@@ -1227,9 +1183,7 @@ func (p *rwFolder) pullerRoutine(in <-chan pullBlockState, out chan<- *sharedPul
 			// try pulling it from another device.
 			_, lastError = scanner.VerifyBuffer(buf, state.block)
 			if lastError != nil {
-				if debug {
-					l.Debugln("request:", p.folder, state.file.Name, state.block.Offset, state.block.Size, "hash mismatch")
-				}
+				l.Debugln("request:", p.folder, state.file.Name, state.block.Offset, state.block.Size, "hash mismatch")
 				continue
 			}

@@ -1339,9 +1293,7 @@ func (p *rwFolder) performFinish(state *sharedPullerState) error {
 func (p *rwFolder) finisherRoutine(in <-chan *sharedPullerState) {
 	for state := range in {
 		if closed, err := state.finalClose(); closed {
-			if debug {
-				l.Debugln(p, "closing", state.file.Name)
-			}
+			l.Debugln(p, "closing", state.file.Name)

 			p.queue.Done(state.file.Name)

--- a/lib/model/sharedpullerstate.go
+++ b/lib/model/sharedpullerstate.go
@@ -193,9 +193,7 @@ func (s *sharedPullerState) failed() error {
 func (s *sharedPullerState) copyDone() {
 	s.mut.Lock()
 	s.copyNeeded--
-	if debug {
-		l.Debugln("sharedPullerState", s.folder, s.file.Name, "copyNeeded ->", s.copyNeeded)
-	}
+	l.Debugln("sharedPullerState", s.folder, s.file.Name, "copyNeeded ->", s.copyNeeded)
 	s.mut.Unlock()
 }

@@ -211,18 +209,14 @@ func (s *sharedPullerState) pullStarted() {
 	s.copyNeeded--
 	s.pullTotal++
 	s.pullNeeded++
-	if debug {
-		l.Debugln("sharedPullerState", s.folder, s.file.Name, "pullNeeded start ->", s.pullNeeded)
-	}
+	l.Debugln("sharedPullerState", s.folder, s.file.Name, "pullNeeded start ->", s.pullNeeded)
 	s.mut.Unlock()
 }

 func (s *sharedPullerState) pullDone() {
 	s.mut.Lock()
 	s.pullNeeded--
-	if debug {
-		l.Debugln("sharedPullerState", s.folder, s.file.Name, "pullNeeded done ->", s.pullNeeded)
-	}
+	l.Debugln("sharedPullerState", s.folder, s.file.Name, "pullNeeded done ->", s.pullNeeded)
 	s.mut.Unlock()
 }