diff --git a/vendor/go.etcd.io/etcd/clientv3/concurrency/mutex.go b/vendor/go.etcd.io/etcd/clientv3/concurrency/mutex.go
index 0135341..306470b 100644
--- a/vendor/go.etcd.io/etcd/clientv3/concurrency/mutex.go
+++ b/vendor/go.etcd.io/etcd/clientv3/concurrency/mutex.go
@@ -16,6 +16,7 @@
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"sync"
 
@@ -23,6 +24,9 @@
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
 )
 
+// ErrLocked is returned by TryLock when Mutex is already locked by another session.
+var ErrLocked = errors.New("mutex: Locked by another session")
+
 // Mutex implements the sync Locker interface with etcd
 type Mutex struct {
 	s *Session
@@ -37,9 +41,56 @@
 	return &Mutex{s, pfx + "/", "", -1, nil}
 }
 
+// TryLock locks the mutex if not already locked by another session.
+// If lock is held by another session, return immediately after attempting necessary cleanup
+// The ctx argument is used for the sending/receiving Txn RPC.
+func (m *Mutex) TryLock(ctx context.Context) error {
+	resp, err := m.tryAcquire(ctx)
+	if err != nil {
+		return err
+	}
+	// if no key on prefix / the minimum rev is key, already hold the lock
+	ownerKey := resp.Responses[1].GetResponseRange().Kvs
+	if len(ownerKey) == 0 || ownerKey[0].CreateRevision == m.myRev {
+		m.hdr = resp.Header
+		return nil
+	}
+	client := m.s.Client()
+	// Cannot lock, so delete the key
+	if _, err := client.Delete(ctx, m.myKey); err != nil {
+		return err
+	}
+	m.myKey = "\x00"
+	m.myRev = -1
+	return ErrLocked
+}
+
 // Lock locks the mutex with a cancelable context. If the context is canceled
 // while trying to acquire the lock, the mutex tries to clean its stale lock entry.
 func (m *Mutex) Lock(ctx context.Context) error {
+	resp, err := m.tryAcquire(ctx)
+	if err != nil {
+		return err
+	}
+	// if no key on prefix / the minimum rev is key, already hold the lock
+	ownerKey := resp.Responses[1].GetResponseRange().Kvs
+	if len(ownerKey) == 0 || ownerKey[0].CreateRevision == m.myRev {
+		m.hdr = resp.Header
+		return nil
+	}
+	client := m.s.Client()
+	// wait for deletion revisions prior to myKey
+	hdr, werr := waitDeletes(ctx, client, m.pfx, m.myRev-1)
+	// release lock key if wait failed
+	if werr != nil {
+		m.Unlock(client.Ctx())
+	} else {
+		m.hdr = hdr
+	}
+	return werr
+}
+
+func (m *Mutex) tryAcquire(ctx context.Context) (*v3.TxnResponse, error) {
 	s := m.s
 	client := m.s.Client()
 
@@ -53,28 +104,13 @@
 	getOwner := v3.OpGet(m.pfx, v3.WithFirstCreate()...)
 	resp, err := client.Txn(ctx).If(cmp).Then(put, getOwner).Else(get, getOwner).Commit()
 	if err != nil {
-		return err
+		return nil, err
 	}
 	m.myRev = resp.Header.Revision
 	if !resp.Succeeded {
 		m.myRev = resp.Responses[0].GetResponseRange().Kvs[0].CreateRevision
 	}
-	// if no key on prefix / the minimum rev is key, already hold the lock
-	ownerKey := resp.Responses[1].GetResponseRange().Kvs
-	if len(ownerKey) == 0 || ownerKey[0].CreateRevision == m.myRev {
-		m.hdr = resp.Header
-		return nil
-	}
-
-	// wait for deletion revisions prior to myKey
-	hdr, werr := waitDeletes(ctx, client, m.pfx, m.myRev-1)
-	// release lock key if wait failed
-	if werr != nil {
-		m.Unlock(client.Ctx())
-	} else {
-		m.hdr = hdr
-	}
-	return werr
+	return resp, nil
 }
 
 func (m *Mutex) Unlock(ctx context.Context) error {