lib/fs, lib/model: Add warning about kqueue resource usage (fixes #7855) (#8249)

go.mod

@@ -53,7 +53,7 @@ require (
 	golang.org/x/sys v0.0.0-20211013075003-97ac67df715c
 	golang.org/x/text v0.3.7
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac
-	golang.org/x/tools v0.1.6
+	golang.org/x/tools v0.1.7
 	google.golang.org/protobuf v1.27.1
 )
 

go.sum

@@ -654,6 +654,8 @@ golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.6 h1:SIasE1FVIQOWz2GEAHFOmoW7xchJcqlucjSULTL0Ag4=
 golang.org/x/tools v0.1.6/go.mod h1:LGqMHiF4EqQNHR1JncWGqT5BVaXmza+X+BDGol+dOxo=
+golang.org/x/tools v0.1.7 h1:6j8CgantCy3yc8JGBqkDLMKWqZ0RDU2g1HVgacojGWQ=
+golang.org/x/tools v0.1.7/go.mod h1:LGqMHiF4EqQNHR1JncWGqT5BVaXmza+X+BDGol+dOxo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

lib/api/api_test.go

@@ -35,6 +35,7 @@ import (
 	"github.com/syncthing/syncthing/lib/locations"
 	"github.com/syncthing/syncthing/lib/logger"
 	loggermocks "github.com/syncthing/syncthing/lib/logger/mocks"
+	"github.com/syncthing/syncthing/lib/model"
 	modelmocks "github.com/syncthing/syncthing/lib/model/mocks"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/svcutil"
@@ -260,7 +261,7 @@ func TestAPIServiceRequests(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer cancel()
+	t.Cleanup(cancel)
 
 	cases := []httpTestCase{
 		// /rest/db
@@ -298,6 +299,12 @@ func TestAPIServiceRequests(t *testing.T) {
 			Type:   "application/json",
 			Prefix: "null",
 		},
+		{
+			URL:    "/rest/db/status?folder=default",
+			Code:   200,
+			Type:   "application/json",
+			Prefix: "",
+		},
 
 		// /rest/stats
 		{
@@ -466,14 +473,17 @@ func TestAPIServiceRequests(t *testing.T) {
 	}
 
 	for _, tc := range cases {
-		t.Log("Testing", tc.URL, "...")
-		testHTTPRequest(t, baseURL, tc, testAPIKey)
+		t.Run(cases[0].URL, func(t *testing.T) {
+			testHTTPRequest(t, baseURL, tc, testAPIKey)
+		})
 	}
 }
 
 // testHTTPRequest tries the given test case, comparing the result code,
 // content type, and result prefix.
 func testHTTPRequest(t *testing.T, baseURL string, tc httpTestCase, apikey string) {
+	t.Parallel()
+
 	timeout := time.Second
 	if tc.Timeout > 0 {
 		timeout = tc.Timeout
@@ -608,7 +618,7 @@ func startHTTP(cfg config.Wrapper) (string, context.CancelFunc, error) {
 	}
 	addrChan := make(chan string)
 	mockedSummary := &modelmocks.FolderSummaryService{}
-	mockedSummary.SummaryReturns(map[string]interface{}{"mocked": true}, nil)
+	mockedSummary.SummaryReturns(new(model.FolderSummary), nil)
 
 	// Instantiate the API service
 	urService := ur.New(cfg, m, connections, false)

lib/fs/basicfs_watch_eventtypes_kqueue.go

@@ -18,4 +18,7 @@ const (
 	subEventMask  = notify.NoteDelete | notify.NoteWrite | notify.NoteRename | notify.Create | notify.NoteAttrib | notify.NoteExtend
 	permEventMask = 0
 	rmEventMask   = notify.NoteDelete | notify.NoteRename
+
+	// WatchKqueue indicates if kqueue is used for filesystem watching
+	WatchKqueue = true
 )

lib/fs/basicfs_watch_notkqueue.go

@@ -0,0 +1,13 @@
+// Copyright (C) 2022 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//go:build !dragonfly && !freebsd && !netbsd && !openbsd
+// +build !dragonfly,!freebsd,!netbsd,!openbsd
+
+package fs
+
+// WatchKqueue indicates if kqueue is used for filesystem watching
+const WatchKqueue = false

lib/model/folder.go

@@ -34,6 +34,9 @@ import (
 	"github.com/syncthing/syncthing/lib/watchaggregator"
 )
 
+// Arbitrary limit that triggers a warning on kqueue systems
+const kqueueItemCountThreshold = 10000
+
 type folder struct {
 	stateTracker
 	config.FolderConfiguration
@@ -81,6 +84,8 @@ type folder struct {
 
 	puller    puller
 	versioner versioner.Versioner
+
+	warnedKqueue bool
 }
 
 type syncRequest struct {
@@ -980,6 +985,19 @@ func (f *folder) monitorWatch(ctx context.Context) {
 	warnedOutside := false
 	var lastWatch time.Time
 	pause := time.Minute
+	// Subscribe to folder summaries only on kqueue systems, to warn about potential high resource usage
+	var summarySub events.Subscription
+	var summaryChan <-chan events.Event
+	if fs.WatchKqueue && !f.warnedKqueue {
+		summarySub = f.evLogger.Subscribe(events.FolderCompletion)
+		summaryChan = summarySub.C()
+	}
+	defer func() {
+		aggrCancel() // aggrCancel might e re-assigned -> call within closure
+		if summaryChan != nil {
+			summarySub.Unsubscribe()
+		}
+	}()
 	for {
 		select {
 		case <-failTimer.C:
@@ -1024,6 +1042,15 @@ func (f *folder) monitorWatch(ctx context.Context) {
 			aggrCancel()
 			errChan = nil
 			aggrCtx, aggrCancel = context.WithCancel(ctx)
+		case ev := <-summaryChan:
+			if data, ok := ev.Data.(FolderSummaryEventData); !ok {
+				f.evLogger.Log(events.Failure, "Unexpected type of folder-summary event in folder.monitorWatch")
+			} else if data.Summary.LocalTotalItems > kqueueItemCountThreshold {
+				f.warnedKqueue = true
+				summarySub.Unsubscribe()
+				summaryChan = nil
+				l.Warnf("Filesystem watching (kqueue) is enabled on %v with a lot of files/directories, and that requires a lot of resources and might slow down your system significantly", f.Description())
+			}
 		case <-ctx.Done():
 			return
 		}

lib/model/folder_summary.go

@@ -29,7 +29,7 @@ const maxDurationSinceLastEventReq = time.Minute
 
 type FolderSummaryService interface {
 	suture.Service
-	Summary(folder string) (map[string]interface{}, error)
+	Summary(folder string) (*FolderSummary, error)
 	OnEventRequest()
 }
 
@@ -76,8 +76,58 @@ func (c *folderSummaryService) String() string {
 	return fmt.Sprintf("FolderSummaryService@%p", c)
 }
 
-func (c *folderSummaryService) Summary(folder string) (map[string]interface{}, error) {
-	var res = make(map[string]interface{})
+// FolderSummary replaces the previously used map[string]interface{}, and needs
+// to keep the structure/naming for api backwards compatibility
+type FolderSummary struct {
+	Errors     int `json:"errors"`
+	PullErrors int `json:"pullErrors"` // deprecated
+
+	Invalid string `json:"invalid"` // deprecated
+
+	GlobalFiles       int   `json:"globalFiles"`
+	GlobalDirectories int   `json:"globalDirectories"`
+	GlobalSymlinks    int   `json:"globalSymlinks"`
+	GlobalDeleted     int   `json:"globalDeleted"`
+	GlobalBytes       int64 `json:"globalBytes"`
+	GlobalTotalItems  int   `json:"globalTotalItems"`
+
+	LocalFiles       int   `json:"localFiles"`
+	LocalDirectories int   `json:"localDirectories"`
+	LocalSymlinks    int   `json:"localSymlinks"`
+	LocalDeleted     int   `json:"localDeleted"`
+	LocalBytes       int64 `json:"localBytes"`
+	LocalTotalItems  int   `json:"localTotalItems"`
+
+	NeedFiles       int   `json:"needFiles"`
+	NeedDirectories int   `json:"needDirectories"`
+	NeedSymlinks    int   `json:"needSymlinks"`
+	NeedDeletes     int   `json:"needDeletes"`
+	NeedBytes       int64 `json:"needBytes"`
+	NeedTotalItems  int   `json:"needTotalItems"`
+
+	ReceiveOnlyChangedFiles       int   `json:"receiveOnlyChangedFiles"`
+	ReceiveOnlyChangedDirectories int   `json:"receiveOnlyChangedDirectories"`
+	ReceiveOnlyChangedSymlinks    int   `json:"receiveOnlyChangedSymlinks"`
+	ReceiveOnlyChangedDeletes     int   `json:"receiveOnlyChangedDeletes"`
+	ReceiveOnlyChangedBytes       int64 `json:"receiveOnlyChangedBytes"`
+	ReceiveOnlyTotalItems         int   `json:"receiveOnlyTotalItems"`
+
+	InSyncFiles int   `json:"inSyncFiles"`
+	InSyncBytes int64 `json:"inSyncBytes"`
+
+	State        string    `json:"state"`
+	StateChanged time.Time `json:"stateChanged"`
+	Error        string    `json:"error"`
+
+	Version  int64 `json:"version"` // deprecated
+	Sequence int64 `json:"sequence"`
+
+	IgnorePatterns bool   `json:"ignorePatterns"`
+	WatchError     string `json:"watchError"`
+}
+
+func (c *folderSummaryService) Summary(folder string) (*FolderSummary, error) {
+	res := new(FolderSummary)
 
 	var local, global, need, ro db.Counts
 	var ourSeq, remoteSeq int64
@@ -101,14 +151,14 @@ func (c *folderSummaryService) Summary(folder string) (map[string]interface{}, e
 		return nil, err
 	}
 
-	res["errors"] = len(errors)
-	res["pullErrors"] = len(errors) // deprecated
+	res.Errors = len(errors)
+	res.PullErrors = len(errors) // deprecated
 
-	res["invalid"] = "" // Deprecated, retains external API for now
+	res.Invalid = "" // Deprecated, retains external API for now
 
-	res["globalFiles"], res["globalDirectories"], res["globalSymlinks"], res["globalDeleted"], res["globalBytes"], res["globalTotalItems"] = global.Files, global.Directories, global.Symlinks, global.Deleted, global.Bytes, global.TotalItems()
+	res.GlobalFiles, res.GlobalDirectories, res.GlobalSymlinks, res.GlobalDeleted, res.GlobalBytes, res.GlobalTotalItems = global.Files, global.Directories, global.Symlinks, global.Deleted, global.Bytes, global.TotalItems()
 
-	res["localFiles"], res["localDirectories"], res["localSymlinks"], res["localDeleted"], res["localBytes"], res["localTotalItems"] = local.Files, local.Directories, local.Symlinks, local.Deleted, local.Bytes, local.TotalItems()
+	res.LocalFiles, res.LocalDirectories, res.LocalSymlinks, res.LocalDeleted, res.LocalBytes, res.LocalTotalItems = local.Files, local.Directories, local.Symlinks, local.Deleted, local.Bytes, local.TotalItems()
 
 	fcfg, haveFcfg := c.cfg.Folder(folder)
 
@@ -122,41 +172,41 @@ func (c *folderSummaryService) Summary(folder string) (map[string]interface{}, e
 	if need.Bytes < 0 {
 		need.Bytes = 0
 	}
-	res["needFiles"], res["needDirectories"], res["needSymlinks"], res["needDeletes"], res["needBytes"], res["needTotalItems"] = need.Files, need.Directories, need.Symlinks, need.Deleted, need.Bytes, need.TotalItems()
+	res.NeedFiles, res.NeedDirectories, res.NeedSymlinks, res.NeedDeletes, res.NeedBytes, res.NeedTotalItems = need.Files, need.Directories, need.Symlinks, need.Deleted, need.Bytes, need.TotalItems()
 
 	if haveFcfg && (fcfg.Type == config.FolderTypeReceiveOnly || fcfg.Type == config.FolderTypeReceiveEncrypted) {
 		// Add statistics for things that have changed locally in a receive
 		// only or receive encrypted folder.
-		res["receiveOnlyChangedFiles"] = ro.Files
-		res["receiveOnlyChangedDirectories"] = ro.Directories
-		res["receiveOnlyChangedSymlinks"] = ro.Symlinks
-		res["receiveOnlyChangedDeletes"] = ro.Deleted
-		res["receiveOnlyChangedBytes"] = ro.Bytes
-		res["receiveOnlyTotalItems"] = ro.TotalItems()
+		res.ReceiveOnlyChangedFiles = ro.Files
+		res.ReceiveOnlyChangedDirectories = ro.Directories
+		res.ReceiveOnlyChangedSymlinks = ro.Symlinks
+		res.ReceiveOnlyChangedDeletes = ro.Deleted
+		res.ReceiveOnlyChangedBytes = ro.Bytes
+		res.ReceiveOnlyTotalItems = ro.TotalItems()
 	}
 
-	res["inSyncFiles"], res["inSyncBytes"] = global.Files-need.Files, global.Bytes-need.Bytes
+	res.InSyncFiles, res.InSyncBytes = global.Files-need.Files, global.Bytes-need.Bytes
 
-	res["state"], res["stateChanged"], err = c.model.State(folder)
+	res.State, res.StateChanged, err = c.model.State(folder)
 	if err != nil {
-		res["error"] = err.Error()
+		res.Error = err.Error()
 	}
 
-	res["version"] = ourSeq + remoteSeq  // legacy
-	res["sequence"] = ourSeq + remoteSeq // new name
+	res.Version = ourSeq + remoteSeq  // legacy
+	res.Sequence = ourSeq + remoteSeq // new name
 
 	ignorePatterns, _, _ := c.model.CurrentIgnores(folder)
-	res["ignorePatterns"] = false
+	res.IgnorePatterns = false
 	for _, line := range ignorePatterns {
 		if len(line) > 0 && !strings.HasPrefix(line, "//") {
-			res["ignorePatterns"] = true
+			res.IgnorePatterns = true
 			break
 		}
 	}
 
 	err = c.model.WatchError(folder)
 	if err != nil {
-		res["watchError"] = err.Error()
+		res.WatchError = err.Error()
 	}
 
 	return res, nil
@@ -322,6 +372,11 @@ func (c *folderSummaryService) foldersToHandle() []string {
 	return res
 }
 
+type FolderSummaryEventData struct {
+	Folder  string         `json:"folder"`
+	Summary *FolderSummary `json:"summary"`
+}
+
 // sendSummary send the summary events for a single folder
 func (c *folderSummaryService) sendSummary(ctx context.Context, folder string) {
 	// The folder summary contains how many bytes, files etc
@@ -330,9 +385,9 @@ func (c *folderSummaryService) sendSummary(ctx context.Context, folder string) {
 	if err != nil {
 		return
 	}
-	c.evLogger.Log(events.FolderSummary, map[string]interface{}{
-		"folder":  folder,
-		"summary": data,
+	c.evLogger.Log(events.FolderSummary, FolderSummaryEventData{
+		Folder:  folder,
+		Summary: data,
 	})
 
 	for _, devCfg := range c.cfg.Folders()[folder].Devices {

lib/model/mocks/folderSummaryService.go

@@ -24,17 +24,17 @@ type FolderSummaryService struct {
 	serveReturnsOnCall map[int]struct {
 		result1 error
 	}
-	SummaryStub        func(string) (map[string]interface{}, error)
+	SummaryStub        func(string) (*model.FolderSummary, error)
 	summaryMutex       sync.RWMutex
 	summaryArgsForCall []struct {
 		arg1 string
 	}
 	summaryReturns struct {
-		result1 map[string]interface{}
+		result1 *model.FolderSummary
 		result2 error
 	}
 	summaryReturnsOnCall map[int]struct {
-		result1 map[string]interface{}
+		result1 *model.FolderSummary
 		result2 error
 	}
 	invocations      map[string][][]interface{}
@@ -126,7 +126,7 @@ func (fake *FolderSummaryService) ServeReturnsOnCall(i int, result1 error) {
 	}{result1}
 }
 
-func (fake *FolderSummaryService) Summary(arg1 string) (map[string]interface{}, error) {
+func (fake *FolderSummaryService) Summary(arg1 string) (*model.FolderSummary, error) {
 	fake.summaryMutex.Lock()
 	ret, specificReturn := fake.summaryReturnsOnCall[len(fake.summaryArgsForCall)]
 	fake.summaryArgsForCall = append(fake.summaryArgsForCall, struct {
@@ -151,7 +151,7 @@ func (fake *FolderSummaryService) SummaryCallCount() int {
 	return len(fake.summaryArgsForCall)
 }
 
-func (fake *FolderSummaryService) SummaryCalls(stub func(string) (map[string]interface{}, error)) {
+func (fake *FolderSummaryService) SummaryCalls(stub func(string) (*model.FolderSummary, error)) {
 	fake.summaryMutex.Lock()
 	defer fake.summaryMutex.Unlock()
 	fake.SummaryStub = stub
@@ -164,28 +164,28 @@ func (fake *FolderSummaryService) SummaryArgsForCall(i int) string {
 	return argsForCall.arg1
 }
 
-func (fake *FolderSummaryService) SummaryReturns(result1 map[string]interface{}, result2 error) {
+func (fake *FolderSummaryService) SummaryReturns(result1 *model.FolderSummary, result2 error) {
 	fake.summaryMutex.Lock()
 	defer fake.summaryMutex.Unlock()
 	fake.SummaryStub = nil
 	fake.summaryReturns = struct {
-		result1 map[string]interface{}
+		result1 *model.FolderSummary
 		result2 error
 	}{result1, result2}
 }
 
-func (fake *FolderSummaryService) SummaryReturnsOnCall(i int, result1 map[string]interface{}, result2 error) {
+func (fake *FolderSummaryService) SummaryReturnsOnCall(i int, result1 *model.FolderSummary, result2 error) {
 	fake.summaryMutex.Lock()
 	defer fake.summaryMutex.Unlock()
 	fake.SummaryStub = nil
 	if fake.summaryReturnsOnCall == nil {
 		fake.summaryReturnsOnCall = make(map[int]struct {
-			result1 map[string]interface{}
+			result1 *model.FolderSummary
 			result2 error
 		})
 	}
 	fake.summaryReturnsOnCall[i] = struct {
-		result1 map[string]interface{}
+		result1 *model.FolderSummary
 		result2 error
 	}{result1, result2}
 }

lib/syncthing/verboseservice.go

@@ -9,8 +9,10 @@ package syncthing
 import (
 	"context"
 	"fmt"
+	"regexp"
 
 	"github.com/syncthing/syncthing/lib/events"
+	"github.com/syncthing/syncthing/lib/model"
 )
 
 // The verbose logging service subscribes to events and prints these in
@@ -46,6 +48,8 @@ func (s *verboseService) Serve(ctx context.Context) error {
 	}
 }
 
+var folderSummaryRemoveDeprecatedRe = regexp.MustCompile(`(Invalid|IgnorePatterns|StateChanged):\S+\s?`)
+
 func (s *verboseService) formatEvent(ev events.Event) string {
 	switch ev.Type {
 	case events.DownloadProgress, events.LocalIndexUpdated:
@@ -116,15 +120,8 @@ func (s *verboseService) formatEvent(ev events.Event) string {
 		return fmt.Sprintf("Completion for folder %q on device %v is %v%%", data["folder"], data["device"], data["completion"])
 
 	case events.FolderSummary:
-		data := ev.Data.(map[string]interface{})
-		sum := make(map[string]interface{})
-		for k, v := range data["summary"].(map[string]interface{}) {
-			if k == "invalid" || k == "ignorePatterns" || k == "stateChanged" {
-				continue
-			}
-			sum[k] = v
-		}
-		return fmt.Sprintf("Summary for folder %q is %v", data["folder"], sum)
+		data := ev.Data.(model.FolderSummaryEventData)
+		return folderSummaryRemoveDeprecatedRe.ReplaceAllString(fmt.Sprintf("Summary for folder %q is %+v", data.Folder, data.Summary), "")
 
 	case events.FolderScanProgress:
 		data := ev.Data.(map[string]interface{})