From d9442aab885149147ef0df7bb7468370b3ee67bd Mon Sep 17 00:00:00 2001
From: Sebastiaan van Stijn <github@gone.nl>
Date: Thu, 3 Aug 2023 01:45:45 +0200
Subject: [PATCH] libnetwork/osl: nwIface: remove mutex altogether

The mutex is only used on reads, but there's nothing protecting writes,
and it looks like nothing is mutating fields after creation, so let's
remove this altogether.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
---
 libnetwork/osl/interface_linux.go | 70 ++++++-------------------------
 1 file changed, 12 insertions(+), 58 deletions(-)

diff --git a/libnetwork/osl/interface_linux.go b/libnetwork/osl/interface_linux.go
index 886291a13f..450d78b9fd 100644
--- a/libnetwork/osl/interface_linux.go
+++ b/libnetwork/osl/interface_linux.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"sync"
 	"syscall"
 	"time"
 
@@ -27,107 +26,66 @@ type nwIface struct {
 	routes      []*net.IPNet
 	bridge      bool
 	ns          *networkNamespace
-	mu          sync.Mutex
 }
 
 func (i *nwIface) SrcName() string {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return i.srcName
 }
 
 func (i *nwIface) DstName() string {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return i.dstName
 }
 
 func (i *nwIface) DstMaster() string {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return i.dstMaster
 }
 
 func (i *nwIface) Bridge() bool {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return i.bridge
 }
 
 func (i *nwIface) Master() string {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return i.master
 }
 
 func (i *nwIface) MacAddress() net.HardwareAddr {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return types.GetMacCopy(i.mac)
 }
 
 func (i *nwIface) Address() *net.IPNet {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return types.GetIPNetCopy(i.address)
 }
 
 func (i *nwIface) AddressIPv6() *net.IPNet {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return types.GetIPNetCopy(i.addressIPv6)
 }
 
 func (i *nwIface) LinkLocalAddresses() []*net.IPNet {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	return i.llAddrs
 }
 
 func (i *nwIface) Routes() []*net.IPNet {
-	i.mu.Lock()
-	defer i.mu.Unlock()
-
 	routes := make([]*net.IPNet, len(i.routes))
 	for index, route := range i.routes {
-		r := types.GetIPNetCopy(route)
-		routes[index] = r
+		routes[index] = types.GetIPNetCopy(route)
 	}
 
 	return routes
 }
 
 func (n *networkNamespace) Interfaces() []Interface {
-	n.Lock()
-	defer n.Unlock()
-
 	ifaces := make([]Interface, len(n.iFaces))
-
 	for i, iface := range n.iFaces {
 		ifaces[i] = iface
 	}
-
 	return ifaces
 }
 
 func (i *nwIface) Remove() error {
-	i.mu.Lock()
-	n := i.ns
-	i.mu.Unlock()
-
-	n.Lock()
-	isDefault := n.isDefault
-	nlh := n.nlHandle
-	n.Unlock()
+	i.ns.Lock()
+	isDefault := i.ns.isDefault
+	nlh := i.ns.nlHandle
+	i.ns.Unlock()
 
 	// Find the network interface identified by the DstName attribute.
 	iface, err := nlh.LinkByName(i.DstName())
@@ -159,29 +117,25 @@ func (i *nwIface) Remove() error {
 		}
 	}
 
-	n.Lock()
-	for index, intf := range n.iFaces {
+	i.ns.Lock()
+	for index, intf := range i.ns.iFaces {
 		if intf == i {
-			n.iFaces = append(n.iFaces[:index], n.iFaces[index+1:]...)
+			i.ns.iFaces = append(i.ns.iFaces[:index], i.ns.iFaces[index+1:]...)
 			break
 		}
 	}
-	n.Unlock()
+	i.ns.Unlock()
 
-	n.checkLoV6()
+	i.ns.checkLoV6()
 
 	return nil
 }
 
 // Returns the sandbox's side veth interface statistics
 func (i *nwIface) Statistics() (*types.InterfaceStatistics, error) {
-	i.mu.Lock()
-	n := i.ns
-	i.mu.Unlock()
-
-	l, err := n.nlHandle.LinkByName(i.DstName())
+	l, err := i.ns.nlHandle.LinkByName(i.DstName())
 	if err != nil {
-		return nil, fmt.Errorf("failed to retrieve the statistics for %s in netns %s: %v", i.DstName(), n.path, err)
+		return nil, fmt.Errorf("failed to retrieve the statistics for %s in netns %s: %v", i.DstName(), i.ns.path, err)
 	}
 
 	stats := l.Attrs().Statistics