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

@@ -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