fix(aliyundrive): limit callback concurrency (#3071)

* fix(aliyundrive): limit callback concurrency - Share proxy callback admission by Aliyun user identity and hold permits for complete response-body lifetimes. - Retry only verified callback-capacity rejections while preserving direct redirects and server download limiting. - Map exhausted temporary capacity to S3 SlowDown through the merged OpenListTeam gofakes3 module. - Cover shared limits, lifecycle release, cancellation, retry classification, and the S3 HTTP response. Co-authored-by: Codex <267193182+codex@users.noreply.github.com> # Conflicts: # go.mod # go.sum # server/s3/pager.go * fix(op): separate redirect and proxy link cache entries - Include redirect mode in the link cache key for all drivers. - Cover both redirect-to-proxy and proxy-to-redirect cache reuse. Co-authored-by: Codex <267193182+codex@users.noreply.github.com> * fix(proxy): close range bodies before opening next - make ServeHTTP own each range body and preserve cleanup failures - remove the aggregate range closer and pass range readers directly - replace the obsolete callback transport test with focused lifecycle coverage Co-authored-by: Codex <267193182+codex@users.noreply.github.com> --------- Co-authored-by: nostalume <nostalucent@gmail.com> Co-authored-by: Codex <267193182+codex@users.noreply.github.com>
2026-10-10 04:53:09 +08:00 · 2026-09-24 12:01:50 +08:00
parent 90acfa18e4
commit 893457cd50
16 changed files with 1139 additions and 69 deletions
@@ -0,0 +1,295 @@
+package aliyundrive_open
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"math/rand/v2"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/OpenListTeam/OpenList/v4/internal/conf"
+	"github.com/OpenListTeam/OpenList/v4/internal/errs"
+	anet "github.com/OpenListTeam/OpenList/v4/internal/net"
+	"github.com/OpenListTeam/OpenList/v4/internal/stream"
+	"github.com/OpenListTeam/OpenList/v4/pkg/http_range"
+)
+
+const (
+	defaultCallbackConcurrency = 1
+	callbackAcquireTimeout     = time.Second
+	callbackRequestAttempts    = 3
+	callbackRetryBaseDelay     = 200 * time.Millisecond
+	callbackErrorBodyLimit     = 64 << 10
+)
+
+var callbackLimiters = struct {
+	sync.Mutex
+	byUser map[string]*callbackLimiter
+}{byUser: make(map[string]*callbackLimiter)}
+
+type callbackLimiter struct {
+	userID        string
+	mu            sync.Mutex
+	active        int
+	nextID        uint64
+	registrations map[uint64]int
+	changed       chan struct{}
+}
+
+type callbackRegistration struct {
+	limiter *callbackLimiter
+	id      uint64
+	once    sync.Once
+}
+
+type callbackPermit struct {
+	limiter *callbackLimiter
+	once    sync.Once
+}
+
+func normalizeCallbackConcurrency(limit int) int {
+	if limit <= 0 {
+		return defaultCallbackConcurrency
+	}
+	return limit
+}
+
+func registerCallbackLimiter(userID string, limit int) *callbackRegistration {
+	callbackLimiters.Lock()
+	defer callbackLimiters.Unlock()
+
+	limiter := callbackLimiters.byUser[userID]
+	if limiter == nil {
+		limiter = &callbackLimiter{
+			userID:        userID,
+			registrations: make(map[uint64]int),
+			changed:       make(chan struct{}),
+		}
+		callbackLimiters.byUser[userID] = limiter
+	}
+	limiter.mu.Lock()
+	limiter.nextID++
+	id := limiter.nextID
+	limiter.registrations[id] = normalizeCallbackConcurrency(limit)
+	limiter.signalLocked()
+	limiter.mu.Unlock()
+	return &callbackRegistration{limiter: limiter, id: id}
+}
+
+func (r *callbackRegistration) unregister() {
+	if r == nil || r.limiter == nil {
+		return
+	}
+	r.once.Do(func() {
+		callbackLimiters.Lock()
+		defer callbackLimiters.Unlock()
+		r.limiter.mu.Lock()
+		delete(r.limiter.registrations, r.id)
+		r.limiter.signalLocked()
+		if len(r.limiter.registrations) == 0 && r.limiter.active == 0 {
+			delete(callbackLimiters.byUser, r.limiter.userID)
+		}
+		r.limiter.mu.Unlock()
+	})
+}
+
+func (r *callbackRegistration) acquire(ctx context.Context) (*callbackPermit, error) {
+	if r == nil || r.limiter == nil {
+		return nil, errs.NewErr(errs.TemporaryCapacity, "callback limiter is unavailable")
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	waitCtx, cancel := context.WithTimeout(ctx, callbackAcquireTimeout)
+	defer cancel()
+	for {
+		r.limiter.mu.Lock()
+		if r.limiter.active < r.limiter.limitLocked() {
+			r.limiter.active++
+			r.limiter.mu.Unlock()
+			return &callbackPermit{limiter: r.limiter}, nil
+		}
+		changed := r.limiter.changed
+		r.limiter.mu.Unlock()
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-waitCtx.Done():
+			if err := ctx.Err(); err != nil {
+				return nil, err
+			}
+			return nil, errs.NewErr(errs.TemporaryCapacity, "timed out waiting for callback admission")
+		case <-changed:
+		}
+	}
+}
+
+func (l *callbackLimiter) limitLocked() int {
+	limit := 0
+	for _, registered := range l.registrations {
+		if limit == 0 || registered < limit {
+			limit = registered
+		}
+	}
+	return limit
+}
+
+func (l *callbackLimiter) signalLocked() {
+	close(l.changed)
+	l.changed = make(chan struct{})
+}
+
+func (p *callbackPermit) release() {
+	if p == nil || p.limiter == nil {
+		return
+	}
+	p.once.Do(func() {
+		callbackLimiters.Lock()
+		defer callbackLimiters.Unlock()
+		p.limiter.mu.Lock()
+		p.limiter.active--
+		p.limiter.signalLocked()
+		if len(p.limiter.registrations) == 0 && p.limiter.active == 0 {
+			delete(callbackLimiters.byUser, p.limiter.userID)
+		}
+		p.limiter.mu.Unlock()
+	})
+}
+
+func (d *AliyundriveOpen) callbackRegistration() *callbackRegistration {
+	if d.callback != nil {
+		return d.callback
+	}
+	if d.ref != nil {
+		return d.ref.callbackRegistration()
+	}
+	return nil
+}
+
+func (d *AliyundriveOpen) callbackRangeReader(url string, size int64) stream.RangeReaderFunc {
+	return func(ctx context.Context, requested http_range.Range) (io.ReadCloser, error) {
+		if requested.Length < 0 || requested.Start+requested.Length > size {
+			requested.Length = size - requested.Start
+		}
+		for attempt := 0; attempt < callbackRequestAttempts; attempt++ {
+			permit, err := d.callbackRegistration().acquire(ctx)
+			if err != nil {
+				return nil, err
+			}
+			body, retry, err := openCallbackRange(ctx, url, size, requested)
+			if !retry && err == nil {
+				return newCallbackBody(ctx, body, permit.release), nil
+			}
+			permit.release()
+			if !retry {
+				return nil, err
+			}
+			if attempt+1 == callbackRequestAttempts {
+				return nil, errs.NewErr(errs.TemporaryCapacity, "Aliyun callback concurrency limit rejected %d attempts", callbackRequestAttempts)
+			}
+			delay := callbackRetryBaseDelay << attempt
+			delay += time.Duration(rand.Int64N(int64(delay / 2)))
+			timer := time.NewTimer(delay)
+			select {
+			case <-ctx.Done():
+				timer.Stop()
+				return nil, ctx.Err()
+			case <-timer.C:
+			}
+		}
+		return nil, errs.NewErr(errs.TemporaryCapacity, "callback attempts exhausted")
+	}
+}
+
+func openCallbackRange(ctx context.Context, url string, size int64, requested http_range.Range) (io.ReadCloser, bool, error) {
+	requestHeader, _ := ctx.Value(conf.RequestHeaderKey).(http.Header)
+	header := anet.ProcessHeader(requestHeader, nil)
+	header = http_range.ApplyRangeToHttpHeader(requested, header)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, false, fmt.Errorf("create Aliyun callback request: %w", err)
+	}
+	req.Header = header
+	response, err := anet.HttpClient().Do(req)
+	if err != nil {
+		return nil, false, fmt.Errorf("Aliyun callback request failed: %w", err)
+	}
+	if response.StatusCode >= http.StatusBadRequest {
+		defer response.Body.Close()
+		body, readErr := io.ReadAll(io.LimitReader(response.Body, callbackErrorBodyLimit))
+		if readErr != nil {
+			return nil, false, fmt.Errorf("read Aliyun callback error response: %w", readErr)
+		}
+		if isCallbackCapacityRejection(response.StatusCode, body) {
+			return nil, true, nil
+		}
+		message := strings.ReplaceAll(strings.TrimSpace(string(body)), url, "<redacted>")
+		return nil, false, fmt.Errorf("Aliyun callback request failed: %w; response: %s", anet.HttpStatusCodeError(response.StatusCode), message)
+	}
+	if requested.Start == 0 && requested.Length == size || response.StatusCode == http.StatusPartialContent || callbackContentRangeStartsAt(response.Header, requested.Start) {
+		return response.Body, false, nil
+	}
+	if response.StatusCode == http.StatusOK {
+		body, rangeErr := anet.GetRangedHttpReader(response.Body, requested.Start, requested.Length)
+		if rangeErr != nil {
+			response.Body.Close()
+			return nil, false, rangeErr
+		}
+		return body, false, nil
+	}
+	return response.Body, false, nil
+}
+
+func isCallbackCapacityRejection(status int, body []byte) bool {
+	return status == http.StatusForbidden &&
+		strings.Contains(string(body), "RequestDeniedByCallback") &&
+		strings.Contains(string(body), "ExceedMaxConcurrency")
+}
+
+func callbackContentRangeStartsAt(header http.Header, offset int64) bool {
+	start, _, err := http_range.ParseContentRange(header.Get("Content-Range"))
+	return err == nil && start == offset
+}
+
+type callbackBody struct {
+	body    io.ReadCloser
+	release func()
+	once    sync.Once
+	mu      sync.Mutex
+	stop    func() bool
+}
+
+func newCallbackBody(ctx context.Context, body io.ReadCloser, release func()) *callbackBody {
+	b := &callbackBody{body: body, release: release}
+	stop := context.AfterFunc(ctx, func() { _ = b.Close() })
+	b.mu.Lock()
+	b.stop = stop
+	b.mu.Unlock()
+	return b
+}
+
+func (b *callbackBody) Read(p []byte) (int, error) {
+	n, err := b.body.Read(p)
+	if err != nil {
+		_ = b.Close()
+	}
+	return n, err
+}
+
+func (b *callbackBody) Close() error {
+	var err error
+	b.once.Do(func() {
+		b.mu.Lock()
+		stop := b.stop
+		b.mu.Unlock()
+		if stop != nil {
+			stop()
+		}
+		err = b.body.Close()
+		b.release()
+	})
+	return err
+}
@@ -0,0 +1,365 @@
+package aliyundrive_open
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/OpenListTeam/OpenList/v4/drivers/base"
+	"github.com/OpenListTeam/OpenList/v4/internal/conf"
+	"github.com/OpenListTeam/OpenList/v4/internal/errs"
+	"github.com/OpenListTeam/OpenList/v4/internal/model"
+	"github.com/OpenListTeam/OpenList/v4/internal/stream"
+	"github.com/OpenListTeam/OpenList/v4/pkg/http_range"
+)
+
+func TestLinkSeparatesRedirectAndProxyRepresentations(t *testing.T) {
+	oldConf := conf.Conf
+	conf.Conf = &conf.Config{}
+	t.Cleanup(func() { conf.Conf = oldConf })
+	base.InitClient()
+
+	var server *httptest.Server
+	server = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/adrive/v1.0/user/getDriveInfo":
+			_, _ = fmt.Fprint(w, `{"user_id":"user-1","resource_drive_id":"drive-1"}`)
+		case "/adrive/v1.0/openFile/getDownloadUrl":
+			_, _ = fmt.Fprintf(w, `{"url":%q}`, server.URL+"/callback")
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer server.Close()
+
+	oldAPIURL := API_URL
+	API_URL = server.URL
+	defer func() { API_URL = oldAPIURL }()
+
+	d := &AliyundriveOpen{Addition: Addition{AccessToken: "token"}}
+	if err := d.Init(t.Context()); err != nil {
+		t.Fatal(err)
+	}
+	defer d.Drop(context.Background())
+	if d.CallbackConcurrency != defaultCallbackConcurrency {
+		t.Fatalf("normalized callback concurrency = %d, want %d", d.CallbackConcurrency, defaultCallbackConcurrency)
+	}
+
+	link, err := d.Link(t.Context(), &model.Object{ID: "file-1", Name: "file", Size: 1}, model.LinkArgs{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if link.RangeReader == nil {
+		t.Fatal("proxy link must own callback acquisition through a range reader")
+	}
+	if _, ok := link.RangeReader.(stream.RateLimitRangeReaderFunc); !ok {
+		t.Fatalf("proxy range reader type = %T, want server-rate-limited reader", link.RangeReader)
+	}
+	direct, err := d.Link(t.Context(), &model.Object{ID: "file-1", Name: "file", Size: 1}, model.LinkArgs{Redirect: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if direct.URL == "" || direct.RangeReader != nil {
+		t.Fatal("redirect link must remain URL-only")
+	}
+}
+
+func TestCallbackRangeHoldsPermitUntilBodyClose(t *testing.T) {
+	oldConf := conf.Conf
+	conf.Conf = &conf.Config{}
+	t.Cleanup(func() { conf.Conf = oldConf })
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Length", "1")
+		w.Header().Set("Content-Range", "bytes 0-0/1")
+		w.WriteHeader(http.StatusPartialContent)
+		_, _ = io.WriteString(w, "x")
+	}))
+	defer server.Close()
+
+	registration := registerCallbackLimiter(t.Name(), 1)
+	t.Cleanup(registration.unregister)
+	d := &AliyundriveOpen{callback: registration}
+	body, err := d.callbackRangeReader(server.URL, 1).RangeRead(t.Context(), http_range.Range{Length: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	registration.limiter.mu.Lock()
+	active := registration.limiter.active
+	registration.limiter.mu.Unlock()
+	if active != 1 {
+		t.Fatalf("active callback bodies = %d, want 1", active)
+	}
+	if err := body.Close(); err != nil {
+		t.Fatal(err)
+	}
+	registration.limiter.mu.Lock()
+	active = registration.limiter.active
+	registration.limiter.mu.Unlock()
+	if active != 0 {
+		t.Fatalf("active callback bodies after Close = %d, want 0", active)
+	}
+}
+
+func TestCallbackLimiterUsesMinimumRegisteredLimit(t *testing.T) {
+	firstRegistration := registerCallbackLimiter(t.Name(), 2)
+	t.Cleanup(firstRegistration.unregister)
+	first, err := firstRegistration.acquire(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	second, err := firstRegistration.acquire(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer first.release()
+	defer second.release()
+
+	lowerRegistration := registerCallbackLimiter(t.Name(), 1)
+	t.Cleanup(lowerRegistration.unregister)
+	acquired := make(chan *callbackPermit, 1)
+	go func() {
+		permit, acquireErr := lowerRegistration.acquire(t.Context())
+		if acquireErr == nil {
+			acquired <- permit
+		}
+	}()
+
+	first.release()
+	select {
+	case permit := <-acquired:
+		permit.release()
+		t.Fatal("lowering the shared limit must wait for all excess bodies to drain")
+	case <-time.After(100 * time.Millisecond):
+	}
+	second.release()
+	select {
+	case permit := <-acquired:
+		permit.release()
+	case <-time.After(time.Second):
+		t.Fatal("admission did not resume after active bodies drained below the new limit")
+	}
+}
+
+func TestCallbackLimiterSeparatesUsers(t *testing.T) {
+	firstUser := registerCallbackLimiter(t.Name()+"-first", 1)
+	secondUser := registerCallbackLimiter(t.Name()+"-second", 1)
+	t.Cleanup(firstUser.unregister)
+	t.Cleanup(secondUser.unregister)
+	first, err := firstUser.acquire(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer first.release()
+	second, err := secondUser.acquire(t.Context())
+	if err != nil {
+		t.Fatalf("independent user was blocked: %v", err)
+	}
+	second.release()
+}
+
+func TestCallbackLimiterReconfigureWaitsForOldBodies(t *testing.T) {
+	userID := t.Name()
+	oldRegistration := registerCallbackLimiter(userID, 2)
+	first, err := oldRegistration.acquire(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	second, err := oldRegistration.acquire(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	oldRegistration.unregister()
+
+	newRegistration := registerCallbackLimiter(userID, 1)
+	t.Cleanup(newRegistration.unregister)
+	acquired := make(chan *callbackPermit, 1)
+	go func() {
+		permit, acquireErr := newRegistration.acquire(t.Context())
+		if acquireErr == nil {
+			acquired <- permit
+		}
+	}()
+	first.release()
+	select {
+	case permit := <-acquired:
+		permit.release()
+		t.Fatal("reconfigured limiter admitted while an old body still occupied the new limit")
+	case <-time.After(100 * time.Millisecond):
+	}
+	second.release()
+	select {
+	case permit := <-acquired:
+		permit.release()
+	case <-time.After(time.Second):
+		t.Fatal("reconfigured limiter did not admit after old bodies drained")
+	}
+}
+
+func TestCallbackLimiterDistinguishesTimeoutAndCancellation(t *testing.T) {
+	registration := registerCallbackLimiter(t.Name(), 1)
+	t.Cleanup(registration.unregister)
+	permit, err := registration.acquire(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer permit.release()
+
+	started := time.Now()
+	_, err = registration.acquire(t.Context())
+	if !errors.Is(err, errs.TemporaryCapacity) {
+		t.Fatalf("admission timeout error = %v, want TemporaryCapacity", err)
+	}
+	if time.Since(started) < callbackAcquireTimeout {
+		t.Fatal("admission timed out before the configured wait elapsed")
+	}
+
+	ctx, cancel := context.WithCancel(t.Context())
+	cancel()
+	_, err = registration.acquire(ctx)
+	if !errors.Is(err, context.Canceled) || errors.Is(err, errs.TemporaryCapacity) {
+		t.Fatalf("canceled admission error = %v, want only context.Canceled", err)
+	}
+}
+
+func TestCallbackCapacityRejectionRequiresBothExactMarkers(t *testing.T) {
+	tests := []struct {
+		name string
+		body string
+		want bool
+	}{
+		{name: "both", body: `{"code":"RequestDeniedByCallback","message":"ExceedMaxConcurrency"}`, want: true},
+		{name: "code only", body: `{"code":"RequestDeniedByCallback"}`},
+		{name: "message only", body: `{"message":"ExceedMaxConcurrency"}`},
+		{name: "case differs", body: `{"code":"requestdeniedbycallback","message":"ExceedMaxConcurrency"}`},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got := isCallbackCapacityRejection(http.StatusForbidden, []byte(test.body)); got != test.want {
+				t.Fatalf("classification = %v, want %v", got, test.want)
+			}
+		})
+	}
+	if isCallbackCapacityRejection(http.StatusTooManyRequests, []byte(`RequestDeniedByCallback ExceedMaxConcurrency`)) {
+		t.Fatal("non-403 response must not be classified as callback capacity")
+	}
+}
+
+func TestCallbackRangeRetriesOnlyVerifiedCapacityRejections(t *testing.T) {
+	var requests atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		requests.Add(1)
+		w.WriteHeader(http.StatusForbidden)
+		_, _ = io.WriteString(w, `{"code":"RequestDeniedByCallback","message":"ExceedMaxConcurrency"}`)
+	}))
+	defer server.Close()
+
+	registration := registerCallbackLimiter(t.Name(), 1)
+	t.Cleanup(registration.unregister)
+	d := &AliyundriveOpen{callback: registration}
+	_, err := d.callbackRangeReader(server.URL+"?token=secret", 1).RangeRead(t.Context(), http_range.Range{Length: 1})
+	if !errors.Is(err, errs.TemporaryCapacity) {
+		t.Fatalf("verified rejection error = %v, want TemporaryCapacity", err)
+	}
+	if requests.Load() != callbackRequestAttempts {
+		t.Fatalf("requests = %d, want %d", requests.Load(), callbackRequestAttempts)
+	}
+	if strings.Contains(err.Error(), "secret") {
+		t.Fatal("capacity error leaked the signed callback URL")
+	}
+	permit, acquireErr := registration.acquire(t.Context())
+	if acquireErr != nil {
+		t.Fatalf("capacity retries leaked admission: %v", acquireErr)
+	}
+	permit.release()
+
+	requests.Store(0)
+	permanent := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		requests.Add(1)
+		w.WriteHeader(http.StatusForbidden)
+		_, _ = io.WriteString(w, `{"code":"RequestDeniedByCallback","message":"denied"}`)
+	}))
+	defer permanent.Close()
+	_, err = d.callbackRangeReader(permanent.URL+"?token=secret", 1).RangeRead(t.Context(), http_range.Range{Length: 1})
+	if errors.Is(err, errs.TemporaryCapacity) {
+		t.Fatalf("permanent 403 error = %v, must not be TemporaryCapacity", err)
+	}
+	if requests.Load() != 1 {
+		t.Fatalf("permanent 403 requests = %d, want 1", requests.Load())
+	}
+	if strings.Contains(err.Error(), "secret") {
+		t.Fatal("permanent error leaked the signed callback URL")
+	}
+}
+
+type countingReadCloser struct {
+	reader io.Reader
+	closed atomic.Int32
+}
+
+func (r *countingReadCloser) Read(p []byte) (int, error) { return r.reader.Read(p) }
+func (r *countingReadCloser) Close() error {
+	r.closed.Add(1)
+	return nil
+}
+
+func TestCallbackBodyReleasesExactlyOnce(t *testing.T) {
+	underlying := &countingReadCloser{reader: strings.NewReader("x")}
+	var released atomic.Int32
+	body := newCallbackBody(t.Context(), underlying, func() { released.Add(1) })
+	_, _ = io.ReadAll(body)
+	if err := body.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if err := body.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if underlying.closed.Load() != 1 || released.Load() != 1 {
+		t.Fatalf("close count = %d, release count = %d; want 1, 1", underlying.closed.Load(), released.Load())
+	}
+}
+
+type failingReadCloser struct {
+	closed atomic.Int32
+}
+
+func (*failingReadCloser) Read([]byte) (int, error) { return 0, errors.New("read failed") }
+func (r *failingReadCloser) Close() error {
+	r.closed.Add(1)
+	return nil
+}
+
+func TestCallbackBodyReadFailureReleasesPermit(t *testing.T) {
+	underlying := &failingReadCloser{}
+	var released atomic.Int32
+	body := newCallbackBody(t.Context(), underlying, func() { released.Add(1) })
+	if _, err := body.Read(make([]byte, 1)); err == nil {
+		t.Fatal("read unexpectedly succeeded")
+	}
+	if underlying.closed.Load() != 1 || released.Load() != 1 {
+		t.Fatalf("close count = %d, release count = %d; want 1, 1", underlying.closed.Load(), released.Load())
+	}
+}
+
+func TestCallbackBodyCancellationReleasesPermit(t *testing.T) {
+	ctx, cancel := context.WithCancel(t.Context())
+	underlying := &countingReadCloser{reader: strings.NewReader("x")}
+	released := make(chan struct{}, 1)
+	_ = newCallbackBody(ctx, underlying, func() { released <- struct{}{} })
+	cancel()
+	select {
+	case <-released:
+	case <-time.After(time.Second):
+		t.Fatal("context cancellation did not release callback admission")
+	}
+	if underlying.closed.Load() != 1 {
+		t.Fatalf("underlying close count = %d, want 1", underlying.closed.Load())
+	}
+}
@@ -11,6 +11,7 @@ import (
 	"github.com/OpenListTeam/OpenList/v4/internal/driver"
 	"github.com/OpenListTeam/OpenList/v4/internal/errs"
 	"github.com/OpenListTeam/OpenList/v4/internal/model"
+	"github.com/OpenListTeam/OpenList/v4/internal/stream"
 	"github.com/OpenListTeam/OpenList/v4/pkg/utils"
 	"github.com/go-resty/resty/v2"
 	log "github.com/sirupsen/logrus"
@@ -24,6 +25,7 @@ type AliyundriveOpen struct {

 	limiter  *limiter
 	ref      *AliyundriveOpen
+	callback *callbackRegistration
 }

 func (d *AliyundriveOpen) Config() driver.Config {
@@ -35,6 +37,7 @@ func (d *AliyundriveOpen) GetAddition() driver.Additional {
 }

 func (d *AliyundriveOpen) Init(ctx context.Context) error {
+	d.CallbackConcurrency = normalizeCallbackConcurrency(d.CallbackConcurrency)
 	d.limiter = getLimiterForUser(globalLimiterUserID) // First create a globally shared limiter to limit the initial requests.
 	if d.LIVPDownloadFormat == "" {
 		d.LIVPDownloadFormat = "jpeg"
@@ -52,6 +55,7 @@ func (d *AliyundriveOpen) Init(ctx context.Context) error {
 	userid := utils.Json.Get(res, "user_id").ToString()
 	d.limiter.free()
 	d.limiter = getLimiterForUser(userid) // Allocate a corresponding limiter for each user.
+	d.callback = registerCallbackLimiter(userid, d.CallbackConcurrency)
 	return nil
 }

@@ -65,6 +69,10 @@ func (d *AliyundriveOpen) InitReference(storage driver.Driver) error {
 }

 func (d *AliyundriveOpen) Drop(ctx context.Context) error {
+	if d.callback != nil {
+		d.callback.unregister()
+		d.callback = nil
+	}
 	d.limiter.free()
 	d.limiter = nil
 	d.ref = nil
@@ -119,10 +127,16 @@ func (d *AliyundriveOpen) Link(ctx context.Context, file model.Obj, args model.L
 		url = utils.Json.Get(res, "streamsUrl", d.LIVPDownloadFormat).ToString()
 	}
 	exp := time.Minute
-	return &model.Link{
+	link := &model.Link{
 		URL:        url,
 		Expiration: &exp,
-	}, nil
+	}
+	if args.Redirect {
+		return link, nil
+	}
+	link.URL = ""
+	link.RangeReader = stream.RateLimitRangeReaderFunc(d.callbackRangeReader(url, file.GetSize()))
+	return link, nil
 }

 func (d *AliyundriveOpen) MakeDir(ctx context.Context, parentDir model.Obj, dirName string) (model.Obj, error) {
@@ -20,6 +20,7 @@ type Addition struct {
 	RapidUpload         bool   `json:"rapid_upload" help:"If you enable this option, the file will be uploaded to the server first, so the progress will be incorrect"`
 	InternalUpload      bool   `json:"internal_upload" help:"If you are using Aliyun ECS is located in Beijing, you can turn it on to boost the upload speed"`
 	LIVPDownloadFormat  string `json:"livp_download_format" type:"select" options:"jpeg,mov" default:"jpeg"`
+	CallbackConcurrency int    `json:"callback_concurrency" type:"number" default:"1" help:"Maximum active proxied downloads shared by Aliyun user"`
 	AccessToken         string
 }

@@ -10,7 +10,7 @@ require (
 	github.com/KarpelesLab/reflink v1.0.2
 	github.com/KirCute/zip v1.0.1
 	github.com/OpenListTeam/go-cache v0.1.0
-	github.com/OpenListTeam/gofakes3 v0.8.1
+	github.com/OpenListTeam/gofakes3 v0.8.2-0.20260911142347-cd3c030a83b4
 	github.com/OpenListTeam/sftpd-openlist v1.0.1
 	github.com/OpenListTeam/tache v0.2.2
 	github.com/OpenListTeam/times v0.1.0
@@ -51,8 +51,8 @@ github.com/OpenListTeam/115-sdk-go v0.2.6 h1:ehXyStvncvn4qRBuknor3kyGZtUmHc0+stj
 github.com/OpenListTeam/115-sdk-go v0.2.6/go.mod h1:cfvitk2lwe6036iNi2h+iNxwxWDifKZsSvNtrur5BqU=
 github.com/OpenListTeam/go-cache v0.1.0 h1:eV2+FCP+rt+E4OCJqLUW7wGccWZNJMV0NNkh+uChbAI=
 github.com/OpenListTeam/go-cache v0.1.0/go.mod h1:AHWjKhNK3LE4rorVdKyEALDHoeMnP8SjiNyfVlB+Pz4=
-github.com/OpenListTeam/gofakes3 v0.8.1 h1:uihJ7Zgb4qIafFcXhcm71BzxCyGRIqBVJYg4YOUa6uY=
-github.com/OpenListTeam/gofakes3 v0.8.1/go.mod h1:mS9Ywbo6aId6BrRzeYjOIOpK0QDVnMoKOIb0hpaQZ3U=
+github.com/OpenListTeam/gofakes3 v0.8.2-0.20260911142347-cd3c030a83b4 h1:Zy7/qg6aCS0OF/FPIoJh9/d0IgcIxpWRvn79ACm2R/Y=
+github.com/OpenListTeam/gofakes3 v0.8.2-0.20260911142347-cd3c030a83b4/go.mod h1:mS9Ywbo6aId6BrRzeYjOIOpK0QDVnMoKOIb0hpaQZ3U=
 github.com/OpenListTeam/gsync v0.1.0 h1:ywzGybOvA3lW8K1BUjKZ2IUlT2FSlzPO4DOazfYXjcs=
 github.com/OpenListTeam/gsync v0.1.0/go.mod h1:h/Rvv9aX/6CdW/7B8di3xK3xNV8dUg45Fehrd/ksZ9s=
 github.com/OpenListTeam/reflink v0.0.0-20260701021214-78760eaeafef h1:67uGHancMF/abMrnkc8abVUWQiG73Wk5d8CKt3RzkFo=
@@ -18,6 +18,7 @@ var (
 	StorageNotInit     = errors.New("storage not init")
 	StreamIncomplete   = errors.New("upload/download stream incomplete, possible network issue")
 	StreamPeekFail     = errors.New("StreamPeekFail")
+	TemporaryCapacity  = errors.New("temporary capacity unavailable")

 	UnknownArchiveFormat      = errors.New("unknown archive format")
 	WrongArchivePassword      = errors.New("wrong archive password")
@@ -118,21 +118,3 @@ type SharingLinkArgs struct {
 type RangeReaderIF interface {
 	RangeRead(ctx context.Context, httpRange http_range.Range) (io.ReadCloser, error)
 }
-
-type RangeReadCloserIF interface {
-	RangeReaderIF
-	utils.ClosersIF
-}
-
-var _ RangeReadCloserIF = (*RangeReadCloser)(nil)
-
-type RangeReadCloser struct {
-	RangeReader RangeReaderIF
-	utils.Closers
-}
-
-func (r *RangeReadCloser) RangeRead(ctx context.Context, httpRange http_range.Range) (io.ReadCloser, error) {
-	rc, err := r.RangeReader.RangeRead(ctx, httpRange)
-	r.Add(rc)
-	return rc, err
-}
@@ -4,6 +4,7 @@ import (
 	"compress/gzip"
 	"context"
 	"crypto/tls"
+	stderrors "errors"
 	"fmt"
 	"io"
 	"mime/multipart"
@@ -15,7 +16,6 @@ import (
 	"time"

 	"github.com/OpenListTeam/OpenList/v4/internal/conf"
-	"github.com/OpenListTeam/OpenList/v4/internal/errs"
 	"github.com/OpenListTeam/OpenList/v4/internal/model"
 	"github.com/OpenListTeam/OpenList/v4/pkg/http_range"
 	"github.com/OpenListTeam/OpenList/v4/pkg/utils"
@@ -25,12 +25,8 @@ import (

 //this file is inspired by GO_SDK net.http.ServeContent

-//type RangeReadCloser struct {
-//	GetReaderForRange RangeReaderFunc
-//}
-
 // ServeHTTP replies to the request using the content in the
-// provided RangeReadCloser. The main benefit of ServeHTTP over io.Copy
+// provided range reader. The main benefit of ServeHTTP over io.Copy
 // is that it handles Range requests properly, sets the MIME type, and
 // handles If-Match, If-Unmodified-Since, If-None-Match, If-Modified-Since,
 // and If-Range requests.
@@ -47,13 +43,11 @@ import (
 // request includes an If-Modified-Since header, ServeHTTP uses
 // modtime to decide whether the content needs to be sent at all.
 //
-// The content's RangeReadCloser method must work: ServeHTTP gives a range,
-// caller will give the reader for that Range.
+// The content's RangeRead method must return a reader for the requested range.
 //
 // If the caller has set w's ETag header formatted per RFC 7232, section 2.3,
 // ServeHTTP uses it to handle requests using If-Match, If-None-Match, or If-Range.
-func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time.Time, size int64, RangeReadCloser model.RangeReadCloserIF) error {
-	defer RangeReadCloser.Close()
+func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time.Time, size int64, rangeReader model.RangeReaderIF) (err error) {
 	setLastModified(w, modTime)
 	done, rangeReq := checkPreconditions(w, r, modTime)
 	if done {
@@ -113,10 +107,11 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 	ctx := r.Context()
 	switch {
 	case len(ranges) == 0:
-		reader, err := RangeReadCloser.RangeRead(ctx, http_range.Range{Length: -1})
+		reader, err := openRange(ctx, rangeReader, http_range.Range{Length: -1})
 		if err != nil {
 			code = http.StatusRequestedRangeNotSatisfiable
-			if statusCode, ok := errs.UnwrapOrSelf(err).(HttpStatusCodeError); ok {
+			var statusCode HttpStatusCodeError
+			if errors.As(err, &statusCode) {
 				code = int(statusCode)
 			}
 			http.Error(w, err.Error(), code)
@@ -136,10 +131,11 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 		// does not request multiple parts might not support
 		// multipart responses."
 		ra := ranges[0]
-		sendContent, err = RangeReadCloser.RangeRead(ctx, ra)
+		sendContent, err = openRange(ctx, rangeReader, ra)
 		if err != nil {
 			code = http.StatusRequestedRangeNotSatisfiable
-			if statusCode, ok := errs.UnwrapOrSelf(err).(HttpStatusCodeError); ok {
+			var statusCode HttpStatusCodeError
+			if errors.As(err, &statusCode) {
 				code = int(statusCode)
 			}
 			http.Error(w, err.Error(), code)
@@ -159,7 +155,6 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 		mw := multipart.NewWriter(pw)
 		w.Header().Set("Content-Type", "multipart/byteranges; boundary="+mw.Boundary())
 		sendContent = pr
-		defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish.
 		go func() {
 			for _, ra := range ranges {
 				part, err := mw.CreatePart(ra.MimeHeader(contentType, size))
@@ -167,21 +162,18 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 					pw.CloseWithError(err)
 					return
 				}
-				reader, err := RangeReadCloser.RangeRead(ctx, ra)
-				if err != nil {
-					pw.CloseWithError(err)
-					return
-				}
-				if _, err := utils.CopyWithBufferN(part, reader, ra.Length); err != nil {
+				if err := copyRange(ctx, part, rangeReader, ra); err != nil {
 					pw.CloseWithError(err)
 					return
 				}
 			}

-			mw.Close()
-			pw.Close()
+			_ = pw.CloseWithError(mw.Close())
 		}()
 	}
+	defer func() {
+		err = closeWithError(err, sendContent)
+	}()

 	w.Header().Set("Accept-Ranges", "bytes")
 	if w.Header().Get("Content-Encoding") == "" {
@@ -201,7 +193,8 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 				log.Warnf("Maybe size incorrect or reader not giving correct/full data, or connection closed before finish. written bytes: %d ,sendSize:%d, ", written, sendSize)
 			}
 			code = http.StatusInternalServerError
-			if statusCode, ok := errs.UnwrapOrSelf(err).(HttpStatusCodeError); ok {
+			var statusCode HttpStatusCodeError
+			if errors.As(err, &statusCode) {
 				code = int(statusCode)
 			}
 			w.WriteHeader(code)
@@ -210,6 +203,43 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request, name string, modTime time
 	}
 	return nil
 }
+
+func copyRange(ctx context.Context, dst io.Writer, rangeReader model.RangeReaderIF, requested http_range.Range) (err error) {
+	reader, err := openRange(ctx, rangeReader, requested)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		err = closeWithError(err, reader)
+	}()
+	_, err = utils.CopyWithBufferN(dst, reader, requested.Length)
+	return err
+}
+
+func openRange(ctx context.Context, rangeReader model.RangeReaderIF, requested http_range.Range) (io.ReadCloser, error) {
+	reader, err := rangeReader.RangeRead(ctx, requested)
+	if err != nil {
+		if reader != nil {
+			err = closeWithError(err, reader)
+		}
+		return nil, err
+	}
+	if reader == nil {
+		return nil, errors.New("range reader returned a nil body")
+	}
+	return reader, nil
+}
+
+func closeWithError(err error, closer io.Closer) error {
+	closeErr := closer.Close()
+	if err == nil {
+		return closeErr
+	}
+	if closeErr == nil {
+		return err
+	}
+	return stderrors.Join(err, closeErr)
+}
 func ProcessHeader(origin, override http.Header) http.Header {
 	result := http.Header{}
 	// client header
@@ -0,0 +1,236 @@
+package net
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/OpenListTeam/OpenList/v4/pkg/http_range"
+)
+
+func TestServeHTTPClosesMultipartRangeBeforeOpeningNext(t *testing.T) {
+	source := newSequentialRangeSource("abc")
+	ctx, cancel := context.WithTimeout(t.Context(), 500*time.Millisecond)
+	defer cancel()
+	request := httptest.NewRequest(http.MethodGet, "/file", nil).WithContext(ctx)
+	request.Header.Set("Range", "bytes=0-0,2-2")
+	recorder := httptest.NewRecorder()
+
+	if err := ServeHTTP(recorder, request, "file.txt", time.Time{}, 3, source); err != nil {
+		t.Fatalf("ServeHTTP() error = %v", err)
+	}
+	response := recorder.Result()
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusPartialContent {
+		t.Fatalf("status = %d, want %d", response.StatusCode, http.StatusPartialContent)
+	}
+
+	mediaType, params, err := mime.ParseMediaType(response.Header.Get("Content-Type"))
+	if err != nil {
+		t.Fatalf("parse Content-Type: %v", err)
+	}
+	if mediaType != "multipart/byteranges" {
+		t.Fatalf("Content-Type = %q, want multipart/byteranges", mediaType)
+	}
+	multipartReader := multipart.NewReader(response.Body, params["boundary"])
+	var parts []string
+	for {
+		part, err := multipartReader.NextPart()
+		if errors.Is(err, io.EOF) {
+			break
+		}
+		if err != nil {
+			t.Fatalf("read multipart part: %v", err)
+		}
+		body, err := io.ReadAll(part)
+		if err != nil {
+			t.Fatalf("read multipart body: %v", err)
+		}
+		parts = append(parts, string(body))
+	}
+	if want := []string{"a", "c"}; !reflect.DeepEqual(parts, want) {
+		t.Fatalf("multipart parts = %q, want %q", parts, want)
+	}
+	assertRangeLifecycle(t, source, []string{"open:0", "close:0", "open:2", "close:2"}, []int{1, 1})
+}
+
+func TestServeHTTPClosesSelectedRangeBody(t *testing.T) {
+	tests := []struct {
+		name       string
+		method     string
+		rangeValue string
+		wantStatus int
+		wantEvents []string
+	}{
+		{name: "full", method: http.MethodGet, wantStatus: http.StatusOK, wantEvents: []string{"open:0", "close:0"}},
+		{name: "single range", method: http.MethodGet, rangeValue: "bytes=1-1", wantStatus: http.StatusPartialContent, wantEvents: []string{"open:1", "close:1"}},
+		{name: "head", method: http.MethodHead, wantStatus: http.StatusOK, wantEvents: []string{"open:0", "close:0"}},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			source := newSequentialRangeSource("abc")
+			request := httptest.NewRequest(test.method, "/file", nil)
+			if test.rangeValue != "" {
+				request.Header.Set("Range", test.rangeValue)
+			}
+			recorder := httptest.NewRecorder()
+
+			if err := ServeHTTP(recorder, request, "file.txt", time.Time{}, 3, source); err != nil {
+				t.Fatalf("ServeHTTP() error = %v", err)
+			}
+			if recorder.Code != test.wantStatus {
+				t.Fatalf("status = %d, want %d", recorder.Code, test.wantStatus)
+			}
+			assertRangeLifecycle(t, source, test.wantEvents, []int{1})
+		})
+	}
+}
+
+func TestServeHTTPClosesRangeAfterWriteFailure(t *testing.T) {
+	writeErr := errors.New("write failed")
+	source := newSequentialRangeSource("abc")
+	request := httptest.NewRequest(http.MethodGet, "/file", nil)
+	writer := &failingResponseWriter{header: make(http.Header), err: writeErr}
+
+	err := ServeHTTP(writer, request, "file.txt", time.Time{}, 3, source)
+	if !errors.Is(err, writeErr) {
+		t.Fatalf("ServeHTTP() error = %v, want %v", err, writeErr)
+	}
+	assertRangeLifecycle(t, source, []string{"open:0", "close:0"}, []int{1})
+}
+
+func TestServeHTTPClosesBodyReturnedWithOpenError(t *testing.T) {
+	source := newSequentialRangeSource("abc")
+	source.openErr = HttpStatusCodeError(http.StatusServiceUnavailable)
+	source.closeErr = errors.New("close failed")
+	request := httptest.NewRequest(http.MethodGet, "/file", nil)
+	recorder := httptest.NewRecorder()
+
+	if err := ServeHTTP(recorder, request, "file.txt", time.Time{}, 3, source); err != nil {
+		t.Fatalf("ServeHTTP() error = %v", err)
+	}
+	if recorder.Code != http.StatusServiceUnavailable {
+		t.Fatalf("status = %d, want %d", recorder.Code, http.StatusServiceUnavailable)
+	}
+	assertRangeLifecycle(t, source, []string{"open:0", "close:0"}, []int{1})
+}
+
+func TestServeHTTPStopsMultipartAfterRangeCloseFailure(t *testing.T) {
+	closeErr := errors.New("close failed")
+	source := newSequentialRangeSource("abc")
+	source.closeErr = closeErr
+	request := httptest.NewRequest(http.MethodGet, "/file", nil)
+	request.Header.Set("Range", "bytes=0-0,2-2")
+	recorder := httptest.NewRecorder()
+
+	err := ServeHTTP(recorder, request, "file.txt", time.Time{}, 3, source)
+	if !errors.Is(err, closeErr) {
+		t.Fatalf("ServeHTTP() error = %v, want %v", err, closeErr)
+	}
+	assertRangeLifecycle(t, source, []string{"open:0", "close:0"}, []int{1})
+}
+
+type sequentialRangeSource struct {
+	content []byte
+	permit  chan struct{}
+
+	mu          sync.Mutex
+	events      []string
+	closeCounts []int
+	closeErr    error
+	openErr     error
+}
+
+func newSequentialRangeSource(content string) *sequentialRangeSource {
+	return &sequentialRangeSource{
+		content: []byte(content),
+		permit:  make(chan struct{}, 1),
+	}
+}
+
+func (s *sequentialRangeSource) RangeRead(ctx context.Context, requested http_range.Range) (io.ReadCloser, error) {
+	select {
+	case s.permit <- struct{}{}:
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	}
+
+	start := int(requested.Start)
+	length := int(requested.Length)
+	if length < 0 || start+length > len(s.content) {
+		length = len(s.content) - start
+	}
+	end := start + length
+	s.mu.Lock()
+	index := len(s.closeCounts)
+	s.events = append(s.events, fmt.Sprintf("open:%d", requested.Start))
+	s.closeCounts = append(s.closeCounts, 0)
+	s.mu.Unlock()
+	return &testReadCloser{
+		Reader: bytes.NewReader(s.content[start:end]),
+		close: func() error {
+			s.mu.Lock()
+			s.closeCounts[index]++
+			closeCalls := s.closeCounts[index]
+			if closeCalls == 1 {
+				s.events = append(s.events, fmt.Sprintf("close:%d", requested.Start))
+			}
+			s.mu.Unlock()
+			if closeCalls != 1 {
+				return fmt.Errorf("body closed %d times", closeCalls)
+			}
+			<-s.permit
+			return s.closeErr
+		},
+	}, s.openErr
+}
+
+func (s *sequentialRangeSource) eventsSnapshot() []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return append([]string(nil), s.events...)
+}
+
+func (s *sequentialRangeSource) closeCountsSnapshot() []int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return append([]int(nil), s.closeCounts...)
+}
+
+func assertRangeLifecycle(t *testing.T, source *sequentialRangeSource, wantEvents []string, wantCloseCounts []int) {
+	t.Helper()
+	if got := source.eventsSnapshot(); !reflect.DeepEqual(got, wantEvents) {
+		t.Fatalf("range lifecycle = %v, want %v", got, wantEvents)
+	}
+	if got := source.closeCountsSnapshot(); !reflect.DeepEqual(got, wantCloseCounts) {
+		t.Fatalf("close counts = %v, want %v", got, wantCloseCounts)
+	}
+}
+
+type failingResponseWriter struct {
+	header http.Header
+	err    error
+}
+
+func (w *failingResponseWriter) Header() http.Header { return w.header }
+func (*failingResponseWriter) WriteHeader(int)       {}
+func (w *failingResponseWriter) Write([]byte) (int, error) {
+	return 0, w.err
+}
+
+type testReadCloser struct {
+	io.Reader
+	close func() error
+}
+
+func (b *testReadCloser) Close() error { return b.close() }
@@ -233,7 +233,10 @@ func Link(ctx context.Context, storage driver.Driver, path string, args model.Li
 	if mode == -1 {
 		mode = storage.(driver.LinkCacheModeResolver).ResolveLinkCacheMode(path)
 	}
-	typeKey := args.Type
+	typeKey := "proxy/" + args.Type
+	if args.Redirect {
+		typeKey = "redirect/" + args.Type
+	}
 	if mode&driver.LinkCacheIP != 0 {
 		typeKey += "/" + args.IP
 	}
@@ -0,0 +1,71 @@
+package op
+
+import (
+	"context"
+	"io"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/OpenListTeam/OpenList/v4/internal/driver"
+	"github.com/OpenListTeam/OpenList/v4/internal/model"
+	"github.com/OpenListTeam/OpenList/v4/internal/stream"
+	"github.com/OpenListTeam/OpenList/v4/pkg/http_range"
+)
+
+type linkModeDriver struct {
+	driver.Driver
+	storage model.Storage
+	calls   int
+}
+
+func (d *linkModeDriver) Config() driver.Config { return driver.Config{} }
+
+func (d *linkModeDriver) GetStorage() *model.Storage { return &d.storage }
+
+func (d *linkModeDriver) Get(context.Context, string) (model.Obj, error) {
+	return &model.Object{Name: "file"}, nil
+}
+
+func (d *linkModeDriver) Link(_ context.Context, _ model.Obj, args model.LinkArgs) (*model.Link, error) {
+	d.calls++
+	expiration := time.Minute
+	if args.Redirect {
+		return &model.Link{URL: "https://example.com/file", Expiration: &expiration}, nil
+	}
+	return &model.Link{
+		RangeReader: stream.RangeReaderFunc(func(context.Context, http_range.Range) (io.ReadCloser, error) {
+			return io.NopCloser(strings.NewReader("file")), nil
+		}),
+		Expiration: &expiration,
+	}, nil
+}
+
+func TestLinkCacheSeparatesRedirectAndProxy(t *testing.T) {
+	for _, tc := range []struct {
+		name          string
+		firstRedirect bool
+	}{
+		{name: "redirect then proxy", firstRedirect: true},
+		{name: "proxy then redirect", firstRedirect: false},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			d := &linkModeDriver{storage: model.Storage{MountPath: "/" + t.Name()}}
+			for _, redirect := range []bool{tc.firstRedirect, !tc.firstRedirect, tc.firstRedirect, !tc.firstRedirect} {
+				link, _, err := Link(context.Background(), d, "/file", model.LinkArgs{Redirect: redirect})
+				if err != nil {
+					t.Fatal(err)
+				}
+				if redirect && (link.URL == "" || link.RangeReader != nil) {
+					t.Fatalf("redirect link has wrong shape: %+v", link)
+				}
+				if !redirect && (link.URL != "" || link.RangeReader == nil) {
+					t.Fatalf("proxy link has wrong shape: %+v", link)
+				}
+			}
+			if d.calls != 2 {
+				t.Fatalf("expected one driver call per mode, got %d", d.calls)
+			}
+		})
+	}
+}
@@ -34,9 +34,7 @@ func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.
 		if link.RangeReader == nil {
 			r = r.WithContext(context.WithValue(r.Context(), conf.RequestHeaderKey, r.Header))
 		}
-		return net.ServeHTTP(w, r, file.GetName(), file.ModTime(), size, &model.RangeReadCloser{
-			RangeReader: rrf,
-		})
+		return net.ServeHTTP(w, r, file.GetName(), file.ModTime(), size, rrf)
 	}

 	if link.RangeReader != nil {
@@ -45,9 +43,7 @@ func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.
 		if size <= 0 {
 			size = file.GetSize()
 		}
-		return net.ServeHTTP(w, r, file.GetName(), file.ModTime(), size, &model.RangeReadCloser{
-			RangeReader: link.RangeReader,
-		})
+		return net.ServeHTTP(w, r, file.GetName(), file.ModTime(), size, link.RangeReader)
 	}

 	//transparent proxy
@@ -152,6 +152,8 @@ func (b *s3Backend) HeadObject(ctx context.Context, bucketName, objectName strin

 // GetObject fetchs the object from the filesystem.
 func (b *s3Backend) GetObject(ctx context.Context, bucketName, objectName string, rangeRequest *gofakes3.ObjectRangeRequest) (s3Obj *gofakes3.Object, err error) {
+	defer func() { err = mapBackendError(err) }()
+
 	bucket, err := getBucketByName(bucketName)
 	if err != nil {
 		return nil, err
@@ -0,0 +1,66 @@
+package s3
+
+import (
+	"context"
+	"encoding/xml"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/OpenListTeam/OpenList/v4/internal/errs"
+	"github.com/OpenListTeam/gofakes3"
+	"github.com/OpenListTeam/gofakes3/s3mem"
+)
+
+func TestMapBackendErrorMapsOnlyTemporaryCapacity(t *testing.T) {
+	capacity := errs.NewErr(errs.TemporaryCapacity, "callback admission timed out")
+	if got := mapBackendError(capacity); got != gofakes3.ErrSlowDown {
+		t.Fatalf("capacity error mapped to %v, want %v", got, gofakes3.ErrSlowDown)
+	}
+
+	permanent := errors.New("permission denied")
+	if got := mapBackendError(permanent); got != permanent {
+		t.Fatalf("permanent error mapped to %v, want original error", got)
+	}
+	if got := mapBackendError(nil); got != nil {
+		t.Fatalf("nil error mapped to %v", got)
+	}
+}
+
+type capacityBackend struct {
+	gofakes3.Backend
+}
+
+func (b capacityBackend) GetObject(context.Context, string, string, *gofakes3.ObjectRangeRequest) (*gofakes3.Object, error) {
+	return nil, mapBackendError(errs.NewErr(errs.TemporaryCapacity, "callback admission timed out"))
+}
+
+func TestTemporaryCapacityProducesS3SlowDownResponse(t *testing.T) {
+	memory := s3mem.New()
+	if err := memory.CreateBucket(t.Context(), "bucket"); err != nil {
+		t.Fatal(err)
+	}
+	server := httptest.NewServer(gofakes3.New(capacityBackend{Backend: memory}).Server())
+	defer server.Close()
+
+	request, err := http.NewRequestWithContext(t.Context(), http.MethodGet, server.URL+"/bucket/object", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	response, err := server.Client().Do(request)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusServiceUnavailable {
+		t.Fatalf("status = %d, want %d", response.StatusCode, http.StatusServiceUnavailable)
+	}
+	var result gofakes3.ErrorResult
+	if err := xml.NewDecoder(response.Body).Decode(&result); err != nil {
+		t.Fatal(err)
+	}
+	if result.Code != gofakes3.ErrSlowDown || result.Message != gofakes3.ErrSlowDown.Message() {
+		t.Fatalf("S3 error = %#v, want SlowDown with standard message", result)
+	}
+}
@@ -5,6 +5,7 @@ package s3
 import (
 	"context"
 	"encoding/json"
+	stderrors "errors"
 	"strings"

 	"github.com/OpenListTeam/OpenList/v4/internal/conf"
@@ -21,6 +22,13 @@ type Bucket struct {
 	Path string `json:"path"`
 }

+func mapBackendError(err error) error {
+	if stderrors.Is(err, errs.TemporaryCapacity) {
+		return gofakes3.ErrSlowDown
+	}
+	return err
+}
+
 const emptyObjectName = "ThisIsAnEmptyFolderInTheS3Bucket"

 func getAndParseBuckets() ([]Bucket, error) {