From 0bd7f5b7a93320178cbe863d102dba70d60190a6 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 10:50:33 +0200
Subject: [PATCH 01/22] add piece buf printers

---
 peer.go           |  1 +
 torrent.go        |  4 ++++
 webseed-peer.go   |  2 +-
 webseed/client.go | 16 ++++++++++++----
 4 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/peer.go b/peer.go
index 29bf8df8e0..4050caa032 100644
--- a/peer.go
+++ b/peer.go
@@ -764,6 +764,7 @@ func (c *Peer) receiveChunk(msg *pp.Message) error {
 	req := c.t.requestIndexFromRequest(ppReq, true)
 
 	recordBlockForSmartBan := sync.OnceFunc(func() {
+		fmt.Println("RCNK", c.t.Name(), msg.Index, len(msg.Piece), c.t.smartBanCache.Hash(msg.Piece))
 		c.recordBlockForSmartBan(req, msg.Piece)
 	})
 	// This needs to occur before we return, but we try to do it when the client is unlocked. It
diff --git a/torrent.go b/torrent.go
index 0e03c218c2..5a84ffc427 100644
--- a/torrent.go
+++ b/torrent.go
@@ -2826,6 +2826,10 @@ func (t *Torrent) tryCreatePieceHasher(lock bool) bool {
 				log.Fmsg("piece %v (%s) hash failure copy error: %v", p, p.hash.HexString(), copyErr).Log(t.logger)
 			}
 
+			buf := bytes.NewBuffer(nil)
+			_, _ = p.Storage().WriteTo(buf)
+			fmt.Println("HSH", t.Name(), p.index, p.length, t.smartBanCache.Hash(buf.Bytes()))
+
 			storageLock.RUnlock()
 
 			p.mu.Lock()
diff --git a/webseed-peer.go b/webseed-peer.go
index b95a33f20d..897cac8055 100644
--- a/webseed-peer.go
+++ b/webseed-peer.go
@@ -156,7 +156,7 @@ func (cn *webseedPeer) nominalMaxRequests(lock bool, lockTorrent bool) maxReques
 var limitedBuffPool = storage.NewLimitedBufferPool(bufPool, 5_000_000_000)
 
 func (ws *webseedPeer) doRequest(r Request) error {
-	webseedRequest := ws.client.NewRequest(ws.intoSpec(r), limitedBuffPool, ws.requestRateLimiter, &ws.receiving)
+	webseedRequest := ws.client.NewRequest(ws.intoSpec(r), limitedBuffPool, ws.requestRateLimiter, &ws.receiving, ws.peer.t.smartBanCache.Hash)
 
 	ws.peer.mu.Lock()
 	ws.activeRequests[r] = webseedRequest
diff --git a/webseed/client.go b/webseed/client.go
index c6b027c1dd..8746301b70 100644
--- a/webseed/client.go
+++ b/webseed/client.go
@@ -1,6 +1,7 @@
 package webseed
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -27,6 +28,7 @@ type requestPart struct {
 	do  func() (*http.Response, io.ReadWriteCloser, error)
 	// Wrap http response bodies for such things as download rate limiting.
 	responseBodyWrapper ResponseBodyWrapper
+	hasher              func(b []byte) uint64 // temp for testing
 }
 
 type Request struct {
@@ -72,7 +74,7 @@ type RequestResult struct {
 	Err     error
 }
 
-func (ws *Client) NewRequest(r RequestSpec, buffers storage.BufferPool, limiter *rate.Limiter, receivingCounter *atomic.Int64) Request {
+func (ws *Client) NewRequest(r RequestSpec, buffers storage.BufferPool, limiter *rate.Limiter, receivingCounter *atomic.Int64, hasher func(b []byte) uint64) Request {
 	ctx, cancel := context.WithCancel(context.Background())
 	var requestParts []requestPart
 	if !ws.fileIndex.Locate(r, func(i int, e segments.Extent) bool {
@@ -110,6 +112,7 @@ func (ws *Client) NewRequest(r RequestSpec, buffers storage.BufferPool, limiter
 
 			return response, buff, err
 		}
+		part.hasher = hasher
 		requestParts = append(requestParts, part)
 		return true
 	}) {
@@ -148,7 +151,7 @@ func (me ErrBadResponse) Error() string {
 	return me.Msg
 }
 
-func recvPartResult(ctx context.Context, buf io.Writer, part requestPart, resp *http.Response) error {
+func recvPartResult(ctx context.Context, writer io.Writer, part requestPart, resp *http.Response) error {
 	defer resp.Body.Close()
 	var body io.Reader = resp.Body
 	if part.responseBodyWrapper != nil {
@@ -161,7 +164,12 @@ func recvPartResult(ctx context.Context, buf io.Writer, part requestPart, resp *
 	}
 	switch resp.StatusCode {
 	case http.StatusPartialContent:
-		copied, err := io.Copy(buf, body)
+		buf, err := io.ReadAll(body)
+		if err != nil {
+			return err
+		}
+		fmt.Println("RECV", part.req.URL, part.e.Start/part.e.Length, len(buf), part.hasher(buf))
+		copied, err := io.Copy(writer, bytes.NewBuffer(buf))
 		if err != nil {
 			return err
 		}
@@ -189,7 +197,7 @@ func recvPartResult(ctx context.Context, buf io.Writer, part requestPart, resp *
 			if discarded != 0 {
 				log.Printf("discarded %v bytes in webseed request response part", discarded)
 			}
-			_, err := io.CopyN(buf, body, part.e.Length)
+			_, err := io.CopyN(writer, body, part.e.Length)
 			return err
 		} else {
 			return ErrBadResponse{"resp status ok but requested range", resp}

From fd900d42788c4c28b127c21f57d0043c6bf576df Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 11:28:32 +0200
Subject: [PATCH 02/22] add piece buf printers

---
 torrent.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/torrent.go b/torrent.go
index 5a84ffc427..866be326f6 100644
--- a/torrent.go
+++ b/torrent.go
@@ -2689,6 +2689,7 @@ func (t *Torrent) pieceHashed(piece pieceIndex, passed bool, hashIoErr error) {
 						// single peer for a piece, and we never progress that piece to completion, we
 						// will never smart-ban them. Discovered in
 						// https://github.com/anacrolix/torrent/issues/715.
+						fmt.Printf("banning %v for being sole dirtier of piece %v after failed piece check", c, piece)
 						t.logger.Levelf(log.Warning, "banning %v for being sole dirtier of piece %v after failed piece check", c, piece)
 						c.ban()
 					}
@@ -2828,7 +2829,7 @@ func (t *Torrent) tryCreatePieceHasher(lock bool) bool {
 
 			buf := bytes.NewBuffer(nil)
 			_, _ = p.Storage().WriteTo(buf)
-			fmt.Println("HSH", t.Name(), p.index, p.length, t.smartBanCache.Hash(buf.Bytes()))
+			fmt.Println("HSH", t.Name(), p.index, p.length(true), t.smartBanCache.Hash(buf.Bytes()), correct, sum, *p.hash)
 
 			storageLock.RUnlock()
 

From b61c24cef76311bafc0382b81edcc5361e8bc037 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 12:06:37 +0200
Subject: [PATCH 03/22] add piece buf printers

---
 torrent.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/torrent.go b/torrent.go
index 866be326f6..124aab20a8 100644
--- a/torrent.go
+++ b/torrent.go
@@ -2689,7 +2689,7 @@ func (t *Torrent) pieceHashed(piece pieceIndex, passed bool, hashIoErr error) {
 						// single peer for a piece, and we never progress that piece to completion, we
 						// will never smart-ban them. Discovered in
 						// https://github.com/anacrolix/torrent/issues/715.
-						fmt.Printf("banning %v for being sole dirtier of piece %v after failed piece check", c, piece)
+						fmt.Printf("banning %v for being sole dirtier of piece %v after failed piece check\n", c, piece)
 						t.logger.Levelf(log.Warning, "banning %v for being sole dirtier of piece %v after failed piece check", c, piece)
 						c.ban()
 					}

From 7215ba7f01fdd6a139c76ff8c19b71a46f20e037 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 18:58:28 +0200
Subject: [PATCH 04/22] restore close on ban

---
 peer.go           |  1 -
 torrent.go        |  4 ----
 webseed-peer.go   |  8 +++++++-
 webseed/client.go | 12 ++----------
 4 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/peer.go b/peer.go
index 4050caa032..29bf8df8e0 100644
--- a/peer.go
+++ b/peer.go
@@ -764,7 +764,6 @@ func (c *Peer) receiveChunk(msg *pp.Message) error {
 	req := c.t.requestIndexFromRequest(ppReq, true)
 
 	recordBlockForSmartBan := sync.OnceFunc(func() {
-		fmt.Println("RCNK", c.t.Name(), msg.Index, len(msg.Piece), c.t.smartBanCache.Hash(msg.Piece))
 		c.recordBlockForSmartBan(req, msg.Piece)
 	})
 	// This needs to occur before we return, but we try to do it when the client is unlocked. It
diff --git a/torrent.go b/torrent.go
index 124aab20a8..2f6eec3aa8 100644
--- a/torrent.go
+++ b/torrent.go
@@ -2827,10 +2827,6 @@ func (t *Torrent) tryCreatePieceHasher(lock bool) bool {
 				log.Fmsg("piece %v (%s) hash failure copy error: %v", p, p.hash.HexString(), copyErr).Log(t.logger)
 			}
 
-			buf := bytes.NewBuffer(nil)
-			_, _ = p.Storage().WriteTo(buf)
-			fmt.Println("HSH", t.Name(), p.index, p.length(true), t.smartBanCache.Hash(buf.Bytes()), correct, sum, *p.hash)
-
 			storageLock.RUnlock()
 
 			p.mu.Lock()
diff --git a/webseed-peer.go b/webseed-peer.go
index 897cac8055..3c50d0ecb0 100644
--- a/webseed-peer.go
+++ b/webseed-peer.go
@@ -156,7 +156,7 @@ func (cn *webseedPeer) nominalMaxRequests(lock bool, lockTorrent bool) maxReques
 var limitedBuffPool = storage.NewLimitedBufferPool(bufPool, 5_000_000_000)
 
 func (ws *webseedPeer) doRequest(r Request) error {
-	webseedRequest := ws.client.NewRequest(ws.intoSpec(r), limitedBuffPool, ws.requestRateLimiter, &ws.receiving, ws.peer.t.smartBanCache.Hash)
+	webseedRequest := ws.client.NewRequest(ws.intoSpec(r), limitedBuffPool, ws.requestRateLimiter, &ws.receiving)
 
 	ws.peer.mu.Lock()
 	ws.activeRequests[r] = webseedRequest
@@ -495,7 +495,13 @@ func (cn *webseedPeer) ban() {
 
 	cn.peer.mu.Lock()
 	cn.peer.banCount++
+	banCount := cn.peer.banCount
 	cn.peer.mu.Unlock()
+
+	if banCount > 5 {
+		cn.peer.close(true)
+		fmt.Println("BCLS", cn.String(), cn.peer.t.numActivePeers(true))
+	}
 }
 
 func (cn *webseedPeer) isLowOnRequests(lock bool, lockTorrent bool) bool {
diff --git a/webseed/client.go b/webseed/client.go
index 8746301b70..4e9781d6e3 100644
--- a/webseed/client.go
+++ b/webseed/client.go
@@ -1,7 +1,6 @@
 package webseed
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -28,7 +27,6 @@ type requestPart struct {
 	do  func() (*http.Response, io.ReadWriteCloser, error)
 	// Wrap http response bodies for such things as download rate limiting.
 	responseBodyWrapper ResponseBodyWrapper
-	hasher              func(b []byte) uint64 // temp for testing
 }
 
 type Request struct {
@@ -74,7 +72,7 @@ type RequestResult struct {
 	Err     error
 }
 
-func (ws *Client) NewRequest(r RequestSpec, buffers storage.BufferPool, limiter *rate.Limiter, receivingCounter *atomic.Int64, hasher func(b []byte) uint64) Request {
+func (ws *Client) NewRequest(r RequestSpec, buffers storage.BufferPool, limiter *rate.Limiter, receivingCounter *atomic.Int64) Request {
 	ctx, cancel := context.WithCancel(context.Background())
 	var requestParts []requestPart
 	if !ws.fileIndex.Locate(r, func(i int, e segments.Extent) bool {
@@ -112,7 +110,6 @@ func (ws *Client) NewRequest(r RequestSpec, buffers storage.BufferPool, limiter
 
 			return response, buff, err
 		}
-		part.hasher = hasher
 		requestParts = append(requestParts, part)
 		return true
 	}) {
@@ -164,12 +161,7 @@ func recvPartResult(ctx context.Context, writer io.Writer, part requestPart, res
 	}
 	switch resp.StatusCode {
 	case http.StatusPartialContent:
-		buf, err := io.ReadAll(body)
-		if err != nil {
-			return err
-		}
-		fmt.Println("RECV", part.req.URL, part.e.Start/part.e.Length, len(buf), part.hasher(buf))
-		copied, err := io.Copy(writer, bytes.NewBuffer(buf))
+		copied, err := io.Copy(writer, body)
 		if err != nil {
 			return err
 		}

From d89315de5773599c7e29f10cbfac4c6bad8966b4 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 19:15:28 +0200
Subject: [PATCH 05/22] add printer status

---
 webseed-peer.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/webseed-peer.go b/webseed-peer.go
index 3c50d0ecb0..8f38973aa5 100644
--- a/webseed-peer.go
+++ b/webseed-peer.go
@@ -499,8 +499,9 @@ func (cn *webseedPeer) ban() {
 	cn.peer.mu.Unlock()
 
 	if banCount > 5 {
+		prev := cn.peer.t.numActivePeers(true)
 		cn.peer.close(true)
-		fmt.Println("BCLS", cn.String(), cn.peer.t.numActivePeers(true))
+		fmt.Println("BCLS", cn.String(), cn.peer.closed.IsSet(), "P", prev, "A", cn.peer.t.numActivePeers(true))
 	}
 }
 

From a5bd06384820b6a9f08f45b18ece506497b09753 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 19:18:43 +0200
Subject: [PATCH 06/22] check closed

---
 webseed-peer.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/webseed-peer.go b/webseed-peer.go
index 8f38973aa5..6ed713c1a1 100644
--- a/webseed-peer.go
+++ b/webseed-peer.go
@@ -498,7 +498,7 @@ func (cn *webseedPeer) ban() {
 	banCount := cn.peer.banCount
 	cn.peer.mu.Unlock()
 
-	if banCount > 5 {
+	if banCount > 5 && !cn.peer.closed.IsSet() {
 		prev := cn.peer.t.numActivePeers(true)
 		cn.peer.close(true)
 		fmt.Println("BCLS", cn.String(), cn.peer.closed.IsSet(), "P", prev, "A", cn.peer.t.numActivePeers(true))

From 6096c4ad058998c8dcacb213599e40d97a2a0a01 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Mon, 8 Jul 2024 19:27:28 +0200
Subject: [PATCH 07/22] add printer status

---
 webseed-peer.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/webseed-peer.go b/webseed-peer.go
index 6ed713c1a1..a98e047cb1 100644
--- a/webseed-peer.go
+++ b/webseed-peer.go
@@ -499,9 +499,9 @@ func (cn *webseedPeer) ban() {
 	cn.peer.mu.Unlock()
 
 	if banCount > 5 && !cn.peer.closed.IsSet() {
-		prev := cn.peer.t.numActivePeers(true)
+		preva, prevc := cn.peer.t.numActivePeers(true), cn.peer.closed.IsSet()
 		cn.peer.close(true)
-		fmt.Println("BCLS", cn.String(), cn.peer.closed.IsSet(), "P", prev, "A", cn.peer.t.numActivePeers(true))
+		fmt.Println("BCLS", cn.String(), "P", prevc, preva, "A", cn.peer.closed.IsSet(), cn.peer.t.numActivePeers(true))
 	}
 }
 

From a37cc0f3846aa2872c4802d37a45f3d5f301e0c8 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Tue, 9 Jul 2024 10:06:35 +0200
Subject: [PATCH 08/22] add lock detection

---
 deferrwl.go |  6 +---
 go.mod      |  3 ++
 go.sum      |  5 ++++
 torrent.go  | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 92 insertions(+), 6 deletions(-)

diff --git a/deferrwl.go b/deferrwl.go
index 2e682f3faf..d398ccc538 100644
--- a/deferrwl.go
+++ b/deferrwl.go
@@ -1,14 +1,10 @@
 package torrent
 
-import (
-	"github.com/anacrolix/sync"
-)
-
 // Runs deferred actions on Unlock. Note that actions are assumed to be the results of changes that
 // would only occur with a write lock at present. The race detector should catch instances of defers
 // without the write lock being held.
 type lockWithDeferreds struct {
-	internal      sync.RWMutex
+	internal      mu //sync.RWMutex
 	unlockActions []func()
 
 	//lc       atomic.Int32
diff --git a/go.mod b/go.mod
index d517ecb213..671e3759cf 100644
--- a/go.mod
+++ b/go.mod
@@ -33,6 +33,7 @@ require (
 	github.com/frankban/quicktest v1.14.6
 	github.com/fsnotify/fsnotify v1.5.4
 	github.com/go-llsqlite/adapter v0.0.0-20230927005056-7f5ce7f0c916
+	github.com/go-stack/stack v1.8.0
 	github.com/google/btree v1.1.2
 	github.com/google/go-cmp v0.5.9
 	github.com/gorilla/websocket v1.5.0
@@ -42,6 +43,7 @@ require (
 	github.com/pion/webrtc/v3 v3.1.42
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.12.2
+	github.com/sasha-s/go-deadlock v0.3.1
 	github.com/stretchr/testify v1.8.4
 	github.com/tidwall/btree v1.6.0
 	go.etcd.io/bbolt v1.3.6
@@ -77,6 +79,7 @@ require (
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/mschoch/smat v0.2.0 // indirect
+	github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 // indirect
 	github.com/pion/dtls/v2 v2.2.4 // indirect
 	github.com/pion/ice/v2 v2.2.6 // indirect
 	github.com/pion/interceptor v0.1.11 // indirect
diff --git a/go.sum b/go.sum
index 98f331c120..b9bb92699b 100644
--- a/go.sum
+++ b/go.sum
@@ -218,6 +218,7 @@ github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
 github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
@@ -364,6 +365,8 @@ github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7J
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
 github.com/onsi/gomega v1.17.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/openzipkin/zipkin-go v0.1.6/go.mod h1:QgAqvLzwWbR/WpD4A3cGpPtJrZXNIiJc5AZX7/PBEpw=
+github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 h1:q2e307iGHPdTGp0hoxKjt1H5pDo6utceo3dQVK3I5XQ=
+github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5/go.mod h1:jvVRKCrJTQWu0XVbaOlby/2lO20uSCHEMzzplHXte1o=
 github.com/philhofer/fwd v1.0.0/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
 github.com/pierrec/lz4 v2.0.5+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pion/datachannel v1.5.2 h1:piB93s8LGmbECrpO84DnkIVWasRMk3IimbcXkTQLE6E=
@@ -463,6 +466,8 @@ github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417 h1:Lt9DzQALzHoDwMBGJ6v
 github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417/go.mod h1:qe5TWALJ8/a1Lqznoc5BDHpYX/8HU60Hm2AwRmqzxqA=
 github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46 h1:GHRpF1pTW19a8tTFrMLUcfWwyC0pnifVo2ClaLq+hP8=
 github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46/go.mod h1:uAQ5PCi+MFsC7HjREoAz1BU+Mq60+05gifQSsHSDG/8=
+github.com/sasha-s/go-deadlock v0.3.1 h1:sqv7fDNShgjcaxkO0JNcOAlr8B9+cV5Ey/OB71efZx0=
+github.com/sasha-s/go-deadlock v0.3.1/go.mod h1:F73l+cr82YSh10GxyRI6qZiCgK64VaZjwesgfQ1/iLM=
 github.com/sclevine/agouti v3.0.0+incompatible/go.mod h1:b4WX9W9L1sfQKXeJf1mUTLZKJ48R1S7H23Ji7oFO5Bw=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
diff --git a/torrent.go b/torrent.go
index 2f6eec3aa8..af1890cb72 100644
--- a/torrent.go
+++ b/torrent.go
@@ -49,10 +49,92 @@ import (
 	typedRoaring "github.com/anacrolix/torrent/typed-roaring"
 	"github.com/anacrolix/torrent/webseed"
 	"github.com/anacrolix/torrent/webtorrent"
+	stack2 "github.com/go-stack/stack"
+	"github.com/sasha-s/go-deadlock"
 )
 
 var bufPool = storage.NewBufferPool()
 
+func stack(skip int) string {
+	return stack2.Trace().TrimBelow(stack2.Caller(skip)).String()
+}
+
+func init() {
+	deadlock.Opts.DeadlockTimeout = 3 * time.Minute
+}
+
+type mu struct {
+	deadlock.RWMutex
+	rlc        atomic.Int32
+	lc         atomic.Int32
+	rlmu       sync.Mutex
+	rlocker    [20]string
+	rlocktime  time.Time
+	locker     string
+	nextlocker string
+	locktime   time.Time
+}
+
+func (m *mu) RLock() {
+	m.RWMutex.RLock()
+	m.rlmu.Lock()
+	rlc := m.rlc.Load()
+	if int(rlc) < len(m.rlocker) {
+		m.rlocker[rlc] = string(stack(2))
+	}
+	if rlc == 0 {
+		m.rlocktime = time.Now()
+	}
+	m.rlc.Add(1)
+	m.rlmu.Unlock()
+	//fmt.Println("R", m.rlc, string(dbg.Stack())[:40])
+
+}
+
+func (m *mu) RUnlock() {
+	m.rlmu.Lock()
+	m.rlc.Add(-1)
+	rlc := m.rlc.Load()
+	if rlc < 0 {
+		panic("lock underflow")
+	}
+	if rlc == 0 {
+		m.rlocktime = time.Time{}
+	}
+	if int(rlc) < len(m.rlocker) {
+		m.rlocker[m.rlc.Load()] = ""
+	}
+	m.rlmu.Unlock()
+	m.RWMutex.RUnlock()
+	//fmt.Println("RUN", m.rlc) //, string(dbg.Stack()))
+}
+
+func (m *mu) Lock() {
+	m.rlmu.Lock()
+	if m.nextlocker == "" {
+		m.nextlocker = string(stack(2))
+	}
+	m.rlmu.Unlock()
+	m.RWMutex.Lock()
+	m.lc.Add(1)
+	m.rlmu.Lock()
+	m.locker = m.nextlocker
+	m.locktime = time.Now()
+	m.nextlocker = ""
+	m.rlmu.Unlock()
+}
+
+func (m *mu) Unlock() {
+	m.lc.Add(-1)
+	if m.lc.Load() < 0 {
+		panic("lock underflow")
+	}
+	m.locker = ""
+	m.locktime = time.Time{}
+	m.RWMutex.Unlock()
+	//fmt.Println("LUN", m.lc) //, string(dbg.Stack()))
+}
+
 // Maintains state of torrent within a Client. Many methods should not be called before the info is
 // available, see .Info and .GotInfo.
 type Torrent struct {
@@ -122,7 +204,7 @@ type Torrent struct {
 	// How many times we've initiated a DHT announce. TODO: Move into stats.
 	numDHTAnnounces int
 
-	mu  sync.RWMutex
+	mu  mu //sync.RWMutex
 	imu sync.RWMutex
 	// Name used if the info name isn't available. Should be cleared when the
 	// Info does become available.

From b654ccb0406ad9d135ce9dde25890274ef34032e Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Tue, 9 Jul 2024 11:10:01 +0200
Subject: [PATCH 09/22] fix torrent deadlock

---
 peerconn.go | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/peerconn.go b/peerconn.go
index 145e907726..9cb7112688 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -674,6 +674,14 @@ func (c *PeerConn) maximumPeerRequestChunkLength() (_ Option[int]) {
 
 // startFetch is for testing purposes currently.
 func (c *PeerConn) onReadRequest(r Request, startFetch bool, lock bool) error {
+	if !c.t.havePiece(pieceIndex(r.Index), true) {
+		// TODO: Tell the peer we don't have the piece, and reject this request.
+		requestsReceivedForMissingPieces.Add(1)
+		return fmt.Errorf("peer requested piece we don't have: %v", r.Index.Int())
+	}
+
+	pieceLength := c.t.pieceLength(pieceIndex(r.Index), true)
+
 	if lock {
 		c.mu.Lock()
 		defer c.mu.Unlock()
@@ -714,12 +722,6 @@ func (c *PeerConn) onReadRequest(r Request, startFetch bool, lock bool) error {
 			return err
 		}
 	}
-	if !c.t.havePiece(pieceIndex(r.Index), true) {
-		// TODO: Tell the peer we don't have the piece, and reject this request.
-		requestsReceivedForMissingPieces.Add(1)
-		return fmt.Errorf("peer requested piece we don't have: %v", r.Index.Int())
-	}
-	pieceLength := c.t.pieceLength(pieceIndex(r.Index), true)
 	// Check this after we know we have the piece, so that the piece length will be known.
 	if chunkOverflowsPiece(r.ChunkSpec, pieceLength) {
 		torrent.Add("bad requests received", 1)

From 34abe352d4cf218b63bcaa702e005a3e92dc4945 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Tue, 9 Jul 2024 19:12:10 +0200
Subject: [PATCH 10/22] add lock to request state data

---
 peerconn.go | 5 ++++-
 torrent.go  | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/peerconn.go b/peerconn.go
index 9cb7112688..70ad5c5e8e 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -759,7 +759,9 @@ func (c *PeerConn) peerRequestDataReader(r Request, prs *peerRequestState) {
 			panic("data must be non-nil to trigger send")
 		}
 		torrent.Add("peer request data read successes", 1)
+		c.mu.Lock()
 		prs.data = b
+		c.mu.Unlock()
 		// This might be required for the error case too (#752 and #753).
 		c.tickleWriter()
 	}
@@ -1213,7 +1215,8 @@ another:
 			}
 			peerRequests = make([]peerRequest, 0, len(c.peerRequests))
 			for r, state := range c.peerRequests {
-				peerRequests = append(peerRequests, peerRequest{r, state})
+				s := *state
+				peerRequests = append(peerRequests, peerRequest{r, &s})
 			}
 		}()
 
diff --git a/torrent.go b/torrent.go
index af1890cb72..266410f084 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1789,6 +1789,9 @@ func (t *Torrent) maxHalfOpen(lock bool) int {
 
 func (t *Torrent) openNewConns(lock bool) (initiated int) {
 	if lock {
+		if t.mu.lc.Load() > 0 || t.mu.rlc.Load() > 0 {
+			fmt.Println("ONC", "L", t.mu.locker, "R", t.mu.rlocker)
+		}
 		t.mu.Lock()
 		defer t.mu.Unlock()
 	}

From 41dd070ca65feadbae34b2d6fa787b68c81ddb0d Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 00:21:39 +0200
Subject: [PATCH 11/22] add printer status

---
 mmap_span/mmap_span.go | 4 ++--
 torrent.go             | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/mmap_span/mmap_span.go b/mmap_span/mmap_span.go
index 067c74e923..adbff4d481 100644
--- a/mmap_span/mmap_span.go
+++ b/mmap_span/mmap_span.go
@@ -154,8 +154,8 @@ func (ms *MMapSpan) locateCopy(copyArgs func(remainingArgument, mmapped []byte)
 func (ms *MMapSpan) WriteAt(index int, p []byte, off int64) (n int, err error) {
 	// log.Printf("writing %v bytes at %v", len(p), off)
 	n, err = func() (n int, err error) {
-		ms.mu.RLock()
-		defer ms.mu.RUnlock()
+		ms.mu.Lock()
+		defer ms.mu.Unlock()
 		n = ms.locateCopy(func(a, b []byte) (_, _ []byte) { return b, a }, p, off)
 		if n != len(p) {
 			err = io.ErrShortWrite
diff --git a/torrent.go b/torrent.go
index 266410f084..3bb70827c3 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1788,14 +1788,19 @@ func (t *Torrent) maxHalfOpen(lock bool) int {
 }
 
 func (t *Torrent) openNewConns(lock bool) (initiated int) {
+	lc := false
 	if lock {
 		if t.mu.lc.Load() > 0 || t.mu.rlc.Load() > 0 {
+			lc = true
 			fmt.Println("ONC", "L", t.mu.locker, "R", t.mu.rlocker)
 		}
 		t.mu.Lock()
 		defer t.mu.Unlock()
 	}
 
+	if lc {
+		fmt.Println("ONC", "LOCKED", "L", t.mu.locker, "R", t.mu.rlocker)
+	}
 	defer t.updateWantPeersEvent(false)
 
 	for t.peers.Len() != 0 {

From d596a63d6c4278c671900dca0401b3058486de03 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 09:52:16 +0200
Subject: [PATCH 12/22] add peer deadlock checker

---
 peer.go    | 2 +-
 torrent.go | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/peer.go b/peer.go
index 29bf8df8e0..5585d30a3d 100644
--- a/peer.go
+++ b/peer.go
@@ -28,7 +28,7 @@ type (
 	Peer struct {
 		// First to ensure 64-bit alignment for atomics. See #262.
 		_stats ConnStats
-		mu     sync.RWMutex
+		mu     mu //sync.RWMutex
 
 		t *Torrent
 
diff --git a/torrent.go b/torrent.go
index 3bb70827c3..507214697b 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1800,6 +1800,7 @@ func (t *Torrent) openNewConns(lock bool) (initiated int) {
 
 	if lc {
 		fmt.Println("ONC", "LOCKED", "L", t.mu.locker, "R", t.mu.rlocker)
+		defer fmt.Println("ONC", "DONE")
 	}
 	defer t.updateWantPeersEvent(false)
 

From 2a7f20d8e4cd3603ae61096411b8635ecff6a978 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 10:27:50 +0200
Subject: [PATCH 13/22] remove lock detector

---
 deferrwl.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/deferrwl.go b/deferrwl.go
index d398ccc538..bddaaf8aa1 100644
--- a/deferrwl.go
+++ b/deferrwl.go
@@ -1,10 +1,12 @@
 package torrent
 
+import "github.com/anacrolix/sync"
+
 // Runs deferred actions on Unlock. Note that actions are assumed to be the results of changes that
 // would only occur with a write lock at present. The race detector should catch instances of defers
 // without the write lock being held.
 type lockWithDeferreds struct {
-	internal      mu //sync.RWMutex
+	internal      sync.RWMutex
 	unlockActions []func()
 
 	//lc       atomic.Int32

From ad9219cd5bad4ead7eeee8de444593dec9c3cb5e Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 13:10:04 +0200
Subject: [PATCH 14/22] re-introduce client lock

---
 deferrwl.go | 35 +----------------------------------
 peer.go     |  2 +-
 2 files changed, 2 insertions(+), 35 deletions(-)

diff --git a/deferrwl.go b/deferrwl.go
index bddaaf8aa1..48bb0b50d2 100644
--- a/deferrwl.go
+++ b/deferrwl.go
@@ -1,40 +1,18 @@
 package torrent
 
-import "github.com/anacrolix/sync"
-
 // Runs deferred actions on Unlock. Note that actions are assumed to be the results of changes that
 // would only occur with a write lock at present. The race detector should catch instances of defers
 // without the write lock being held.
 type lockWithDeferreds struct {
-	internal      sync.RWMutex
+	internal      mu //sync.RWMutex
 	unlockActions []func()
-
-	//lc       atomic.Int32
-	//locker   string
-	//locktime time.Time
-	//rlc      atomic.Int32
-	//rlmu     sync.Mutex
-	//rlocker  [20]string
 }
 
-//func stack(skip int) string {
-//	return stack2.Trace().TrimBelow(stack2.Caller(skip)).String()
-//}
-
 func (me *lockWithDeferreds) Lock() {
 	me.internal.Lock()
-	// me.lc.Add(1)
-	// me.locker = stack(2)
-	// me.locktime = time.Now()
 }
 
 func (me *lockWithDeferreds) Unlock() {
-	//	me.lc.Add(-1)
-	//	if me.lc.Load() < 0 {
-	//		panic("lock underflow")
-	//	}
-	//	me.locker = ""
-	//	me.locktime = time.Time{}
 	unlockActions := me.unlockActions
 	for i := 0; i < len(unlockActions); i += 1 {
 		unlockActions[i]()
@@ -45,20 +23,9 @@ func (me *lockWithDeferreds) Unlock() {
 
 func (me *lockWithDeferreds) RLock() {
 	me.internal.RLock()
-	// me.rlmu.Lock()
-	// me.rlocker[me.rlc.Load()] = string(stack(2))
-	// me.rlc.Add(1)
-	// me.rlmu.Unlock()
 }
 
 func (me *lockWithDeferreds) RUnlock() {
-	//	me.rlmu.Lock()
-	//	me.rlc.Add(-1)
-	//	if me.rlc.Load() < 0 {
-	//		panic("lock underflow")
-	//	}
-	//	me.rlocker[me.rlc.Load()] = ""
-	//	me.rlmu.Unlock()
 	me.internal.RUnlock()
 }
 
diff --git a/peer.go b/peer.go
index 5585d30a3d..29bf8df8e0 100644
--- a/peer.go
+++ b/peer.go
@@ -28,7 +28,7 @@ type (
 	Peer struct {
 		// First to ensure 64-bit alignment for atomics. See #262.
 		_stats ConnStats
-		mu     mu //sync.RWMutex
+		mu     sync.RWMutex
 
 		t *Torrent
 

From 99d65bf510cf5770cc439ef0aae690b91bf7b3d0 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 14:19:29 +0200
Subject: [PATCH 15/22] export status strings

---
 peer.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/peer.go b/peer.go
index 29bf8df8e0..6bfda7958b 100644
--- a/peer.go
+++ b/peer.go
@@ -245,10 +245,16 @@ func eventAgeString(t time.Time) string {
 }
 
 // Inspired by https://github.com/transmission/transmission/wiki/Peer-Status-Text.
-func (cn *Peer) statusFlags() (ret string) {
+func (cn *Peer) StatusFlags() (ret string) {
 	c := func(b byte) {
 		ret += string([]byte{b})
 	}
+	if cn.closed.IsSet() {
+		ret = "op-"
+	} else {
+		ret = "cl-"
+	}
+
 	if cn.requestState.Interested {
 		c('i')
 	}
@@ -354,7 +360,7 @@ func (cn *Peer) writeStatus(w io.Writer, lock bool, lockTorrent bool) {
 		cn.PeerMaxRequests,
 		len(cn.peerRequests),
 		localClientReqq,
-		cn.statusFlags(),
+		cn.StatusFlags(),
 		cn.downloadRate()/(1<<10),
 	)
 	fmt.Fprintf(w, "requested pieces:")

From 1453b96cd4fbdb6b09866681f1d2d26e87e360d8 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 15:24:11 +0200
Subject: [PATCH 16/22] track peer lock not client

---
 deferrwl.go | 4 +++-
 peer.go     | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/deferrwl.go b/deferrwl.go
index 48bb0b50d2..bf95be244f 100644
--- a/deferrwl.go
+++ b/deferrwl.go
@@ -1,10 +1,12 @@
 package torrent
 
+import "github.com/anacrolix/sync"
+
 // Runs deferred actions on Unlock. Note that actions are assumed to be the results of changes that
 // would only occur with a write lock at present. The race detector should catch instances of defers
 // without the write lock being held.
 type lockWithDeferreds struct {
-	internal      mu //sync.RWMutex
+	internal      sync.RWMutex
 	unlockActions []func()
 }
 
diff --git a/peer.go b/peer.go
index 6bfda7958b..da353d7ce6 100644
--- a/peer.go
+++ b/peer.go
@@ -28,7 +28,7 @@ type (
 	Peer struct {
 		// First to ensure 64-bit alignment for atomics. See #262.
 		_stats ConnStats
-		mu     sync.RWMutex
+		mu     mu //sync.RWMutex
 
 		t *Torrent
 

From 10f1ce2b375a2f054119402c8e2dfb35ab3e1e29 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 15:31:19 +0200
Subject: [PATCH 17/22] fix flags

---
 peer.go | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/peer.go b/peer.go
index da353d7ce6..5033a9f149 100644
--- a/peer.go
+++ b/peer.go
@@ -250,9 +250,9 @@ func (cn *Peer) StatusFlags() (ret string) {
 		ret += string([]byte{b})
 	}
 	if cn.closed.IsSet() {
-		ret = "op-"
-	} else {
 		ret = "cl-"
+	} else {
+		ret = "op-"
 	}
 
 	if cn.requestState.Interested {
@@ -263,12 +263,14 @@ func (cn *Peer) StatusFlags() (ret string) {
 	}
 	c('-')
 	ret += cn.connectionFlags()
-	c('-')
-	if cn.peerInterested {
-		c('i')
-	}
-	if cn.peerChoking {
-		c('c')
+	if cn.peerInterested || cn.peerChoking {
+		c('-')
+		if cn.peerInterested {
+			c('i')
+		}
+		if cn.peerChoking {
+			c('c')
+		}
 	}
 	return
 }

From 866f4dce937df13cf2baad42dc54cae12e17928a Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Wed, 10 Jul 2024 18:19:24 +0200
Subject: [PATCH 18/22] fix fastenabled lock param

---
 peer.go     | 4 ++--
 peerconn.go | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/peer.go b/peer.go
index 5033a9f149..3521ec6cd6 100644
--- a/peer.go
+++ b/peer.go
@@ -250,9 +250,9 @@ func (cn *Peer) StatusFlags() (ret string) {
 		ret += string([]byte{b})
 	}
 	if cn.closed.IsSet() {
-		ret = "cl-"
+		ret = "c-"
 	} else {
-		ret = "op-"
+		ret = "o-"
 	}
 
 	if cn.requestState.Interested {
diff --git a/peerconn.go b/peerconn.go
index 70ad5c5e8e..85a0fcc756 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -647,7 +647,7 @@ func (c *PeerConn) fastEnabled(lock bool) bool {
 }
 
 func (c *PeerConn) reject(r Request, lock bool) {
-	if !c.fastEnabled(true) {
+	if !c.fastEnabled(lock) {
 		panic("fast not enabled")
 	}
 	c.write(r.ToMsg(pp.Reject), lock)

From 6b884788291d105706d82e4ad0de8b7846072782 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Thu, 11 Jul 2024 00:36:47 +0200
Subject: [PATCH 19/22] remove printer

---
 torrent.go | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/torrent.go b/torrent.go
index 507214697b..af1890cb72 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1788,20 +1788,11 @@ func (t *Torrent) maxHalfOpen(lock bool) int {
 }
 
 func (t *Torrent) openNewConns(lock bool) (initiated int) {
-	lc := false
 	if lock {
-		if t.mu.lc.Load() > 0 || t.mu.rlc.Load() > 0 {
-			lc = true
-			fmt.Println("ONC", "L", t.mu.locker, "R", t.mu.rlocker)
-		}
 		t.mu.Lock()
 		defer t.mu.Unlock()
 	}
 
-	if lc {
-		fmt.Println("ONC", "LOCKED", "L", t.mu.locker, "R", t.mu.rlocker)
-		defer fmt.Println("ONC", "DONE")
-	}
 	defer t.updateWantPeersEvent(false)
 
 	for t.peers.Len() != 0 {

From 1b56deb061dbf7dd41733aedcc5e37aced8f9e9f Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Thu, 11 Jul 2024 00:41:27 +0200
Subject: [PATCH 20/22] remove printer

---
 torrent.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/torrent.go b/torrent.go
index af1890cb72..a3481a0911 100644
--- a/torrent.go
+++ b/torrent.go
@@ -2771,7 +2771,6 @@ func (t *Torrent) pieceHashed(piece pieceIndex, passed bool, hashIoErr error) {
 						// single peer for a piece, and we never progress that piece to completion, we
 						// will never smart-ban them. Discovered in
 						// https://github.com/anacrolix/torrent/issues/715.
-						fmt.Printf("banning %v for being sole dirtier of piece %v after failed piece check\n", c, piece)
 						t.logger.Levelf(log.Warning, "banning %v for being sole dirtier of piece %v after failed piece check", c, piece)
 						c.ban()
 					}

From 4b6e144f1694d44b586f1fc918ff65e6d631dde3 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Thu, 11 Jul 2024 14:03:08 +0200
Subject: [PATCH 21/22] increase ban count to 16

---
 webseed-peer.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/webseed-peer.go b/webseed-peer.go
index a98e047cb1..a4a8c2e451 100644
--- a/webseed-peer.go
+++ b/webseed-peer.go
@@ -498,10 +498,8 @@ func (cn *webseedPeer) ban() {
 	banCount := cn.peer.banCount
 	cn.peer.mu.Unlock()
 
-	if banCount > 5 && !cn.peer.closed.IsSet() {
-		preva, prevc := cn.peer.t.numActivePeers(true), cn.peer.closed.IsSet()
+	if banCount > 16 && !cn.peer.closed.IsSet() {
 		cn.peer.close(true)
-		fmt.Println("BCLS", cn.String(), "P", prevc, preva, "A", cn.peer.closed.IsSet(), cn.peer.t.numActivePeers(true))
 	}
 }
 

From 7de8739ed3cb07356fb9968bb44e38649a92c4b6 Mon Sep 17 00:00:00 2001
From: Mark Holt <mark@distributed.vision>
Date: Thu, 11 Jul 2024 17:59:25 +0200
Subject: [PATCH 22/22] remove deadlock tests

---
 go.mod     |  3 --
 go.sum     |  5 ----
 peer.go    |  2 +-
 torrent.go | 84 +-----------------------------------------------------
 4 files changed, 2 insertions(+), 92 deletions(-)

diff --git a/go.mod b/go.mod
index 671e3759cf..d517ecb213 100644
--- a/go.mod
+++ b/go.mod
@@ -33,7 +33,6 @@ require (
 	github.com/frankban/quicktest v1.14.6
 	github.com/fsnotify/fsnotify v1.5.4
 	github.com/go-llsqlite/adapter v0.0.0-20230927005056-7f5ce7f0c916
-	github.com/go-stack/stack v1.8.0
 	github.com/google/btree v1.1.2
 	github.com/google/go-cmp v0.5.9
 	github.com/gorilla/websocket v1.5.0
@@ -43,7 +42,6 @@ require (
 	github.com/pion/webrtc/v3 v3.1.42
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.12.2
-	github.com/sasha-s/go-deadlock v0.3.1
 	github.com/stretchr/testify v1.8.4
 	github.com/tidwall/btree v1.6.0
 	go.etcd.io/bbolt v1.3.6
@@ -79,7 +77,6 @@ require (
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/mschoch/smat v0.2.0 // indirect
-	github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 // indirect
 	github.com/pion/dtls/v2 v2.2.4 // indirect
 	github.com/pion/ice/v2 v2.2.6 // indirect
 	github.com/pion/interceptor v0.1.11 // indirect
diff --git a/go.sum b/go.sum
index b9bb92699b..98f331c120 100644
--- a/go.sum
+++ b/go.sum
@@ -218,7 +218,6 @@ github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
 github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
-github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
@@ -365,8 +364,6 @@ github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7J
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
 github.com/onsi/gomega v1.17.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/openzipkin/zipkin-go v0.1.6/go.mod h1:QgAqvLzwWbR/WpD4A3cGpPtJrZXNIiJc5AZX7/PBEpw=
-github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 h1:q2e307iGHPdTGp0hoxKjt1H5pDo6utceo3dQVK3I5XQ=
-github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5/go.mod h1:jvVRKCrJTQWu0XVbaOlby/2lO20uSCHEMzzplHXte1o=
 github.com/philhofer/fwd v1.0.0/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
 github.com/pierrec/lz4 v2.0.5+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pion/datachannel v1.5.2 h1:piB93s8LGmbECrpO84DnkIVWasRMk3IimbcXkTQLE6E=
@@ -466,8 +463,6 @@ github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417 h1:Lt9DzQALzHoDwMBGJ6v
 github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417/go.mod h1:qe5TWALJ8/a1Lqznoc5BDHpYX/8HU60Hm2AwRmqzxqA=
 github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46 h1:GHRpF1pTW19a8tTFrMLUcfWwyC0pnifVo2ClaLq+hP8=
 github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46/go.mod h1:uAQ5PCi+MFsC7HjREoAz1BU+Mq60+05gifQSsHSDG/8=
-github.com/sasha-s/go-deadlock v0.3.1 h1:sqv7fDNShgjcaxkO0JNcOAlr8B9+cV5Ey/OB71efZx0=
-github.com/sasha-s/go-deadlock v0.3.1/go.mod h1:F73l+cr82YSh10GxyRI6qZiCgK64VaZjwesgfQ1/iLM=
 github.com/sclevine/agouti v3.0.0+incompatible/go.mod h1:b4WX9W9L1sfQKXeJf1mUTLZKJ48R1S7H23Ji7oFO5Bw=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
diff --git a/peer.go b/peer.go
index 3521ec6cd6..e2de52bcd4 100644
--- a/peer.go
+++ b/peer.go
@@ -28,7 +28,7 @@ type (
 	Peer struct {
 		// First to ensure 64-bit alignment for atomics. See #262.
 		_stats ConnStats
-		mu     mu //sync.RWMutex
+		mu     sync.RWMutex
 
 		t *Torrent
 
diff --git a/torrent.go b/torrent.go
index a3481a0911..0e03c218c2 100644
--- a/torrent.go
+++ b/torrent.go
@@ -49,92 +49,10 @@ import (
 	typedRoaring "github.com/anacrolix/torrent/typed-roaring"
 	"github.com/anacrolix/torrent/webseed"
 	"github.com/anacrolix/torrent/webtorrent"
-	stack2 "github.com/go-stack/stack"
-	"github.com/sasha-s/go-deadlock"
 )
 
 var bufPool = storage.NewBufferPool()
 
-func stack(skip int) string {
-	return stack2.Trace().TrimBelow(stack2.Caller(skip)).String()
-}
-
-func init() {
-	deadlock.Opts.DeadlockTimeout = 3 * time.Minute
-}
-
-type mu struct {
-	deadlock.RWMutex
-	rlc        atomic.Int32
-	lc         atomic.Int32
-	rlmu       sync.Mutex
-	rlocker    [20]string
-	rlocktime  time.Time
-	locker     string
-	nextlocker string
-	locktime   time.Time
-}
-
-func (m *mu) RLock() {
-	m.RWMutex.RLock()
-	m.rlmu.Lock()
-	rlc := m.rlc.Load()
-	if int(rlc) < len(m.rlocker) {
-		m.rlocker[rlc] = string(stack(2))
-	}
-	if rlc == 0 {
-		m.rlocktime = time.Now()
-	}
-	m.rlc.Add(1)
-	m.rlmu.Unlock()
-	//fmt.Println("R", m.rlc, string(dbg.Stack())[:40])
-
-}
-
-func (m *mu) RUnlock() {
-	m.rlmu.Lock()
-	m.rlc.Add(-1)
-	rlc := m.rlc.Load()
-	if rlc < 0 {
-		panic("lock underflow")
-	}
-	if rlc == 0 {
-		m.rlocktime = time.Time{}
-	}
-	if int(rlc) < len(m.rlocker) {
-		m.rlocker[m.rlc.Load()] = ""
-	}
-	m.rlmu.Unlock()
-	m.RWMutex.RUnlock()
-	//fmt.Println("RUN", m.rlc) //, string(dbg.Stack()))
-}
-
-func (m *mu) Lock() {
-	m.rlmu.Lock()
-	if m.nextlocker == "" {
-		m.nextlocker = string(stack(2))
-	}
-	m.rlmu.Unlock()
-	m.RWMutex.Lock()
-	m.lc.Add(1)
-	m.rlmu.Lock()
-	m.locker = m.nextlocker
-	m.locktime = time.Now()
-	m.nextlocker = ""
-	m.rlmu.Unlock()
-}
-
-func (m *mu) Unlock() {
-	m.lc.Add(-1)
-	if m.lc.Load() < 0 {
-		panic("lock underflow")
-	}
-	m.locker = ""
-	m.locktime = time.Time{}
-	m.RWMutex.Unlock()
-	//fmt.Println("LUN", m.lc) //, string(dbg.Stack()))
-}
-
 // Maintains state of torrent within a Client. Many methods should not be called before the info is
 // available, see .Info and .GotInfo.
 type Torrent struct {
@@ -204,7 +122,7 @@ type Torrent struct {
 	// How many times we've initiated a DHT announce. TODO: Move into stats.
 	numDHTAnnounces int
 
-	mu  mu //sync.RWMutex
+	mu  sync.RWMutex
 	imu sync.RWMutex
 	// Name used if the info name isn't available. Should be cleared when the
 	// Info does become available.