Merge pull request #41274 from thaJeztah/19.03_backport_Double_RLock

[19.03 backport] plugin: fix a double RLock bug
diff --git a/hack/dockerfile/install/rootlesskit.installer b/hack/dockerfile/install/rootlesskit.installer
index 950c7c2..590fb90 100755
--- a/hack/dockerfile/install/rootlesskit.installer
+++ b/hack/dockerfile/install/rootlesskit.installer
@@ -1,7 +1,7 @@
 #!/bin/sh
 
-# v0.9.5
-: ${ROOTLESSKIT_COMMIT:=3f5728fbb2b6abdc63d59759e72735442ce6424e}
+# v0.10.0
+: ${ROOTLESSKIT_COMMIT:=f766387c3b360bc6dc6c2f353e9e630cf2c6ee86}
 
 install_rootlesskit() {
 	case "$1" in
diff --git a/integration-cli/docker_cli_run_test.go b/integration-cli/docker_cli_run_test.go
index b0473a4..cd7c716 100644
--- a/integration-cli/docker_cli_run_test.go
+++ b/integration-cli/docker_cli_run_test.go
@@ -1403,7 +1403,7 @@
 	// Not applicable on Windows as Windows does not support --user
 	testRequires(c, testEnv.IsLocalDaemon, Network, DaemonIsLinux, NotArm)
 
-	dockerCmd(c, "run", "--name=testperm", "--user=nobody", "busybox", "nslookup", "apt.dockerproject.org")
+	dockerCmd(c, "run", "--name=testperm", "--user=nobody", "busybox", "nslookup", "example.com")
 
 	cID := getIDByName(c, "testperm")
 
diff --git a/vendor.conf b/vendor.conf
index 8eda471..3c6e1be 100644
--- a/vendor.conf
+++ b/vendor.conf
@@ -26,7 +26,7 @@
 golang.org/x/sync                                   e225da77a7e68af35c70ccbf71af2b83e6acac3c
 
 # buildkit
-github.com/moby/buildkit                            a1e4f48e712360e6292819e55285e1bbacce99d4 # v0.6.4-26-ga1e4f48e
+github.com/moby/buildkit                            da1f4bf179dcc972d023f30c0d5b4a6576ff385f # v0.6.4-28-gda1f4bf1
 github.com/tonistiigi/fsutil                        6c909ab392c173a4264ae1bfcbc0450b9aac0c7d
 github.com/grpc-ecosystem/grpc-opentracing          8e809c8a86450a29b90dcc9efbf062d0fe6d9746
 github.com/opentracing/opentracing-go               1361b9cd60be79c4c3a7fa9841b3c132e40066a7
diff --git a/vendor/github.com/moby/buildkit/cache/refs.go b/vendor/github.com/moby/buildkit/cache/refs.go
index 3f9d282..782cbba 100644
--- a/vendor/github.com/moby/buildkit/cache/refs.go
+++ b/vendor/github.com/moby/buildkit/cache/refs.go
@@ -123,7 +123,10 @@
 		cr.mu.Unlock()
 		return usage.Size, nil
 	})
-	return s.(int64), err
+	if err != nil {
+		return 0, err
+	}
+	return s.(int64), nil
 }
 
 func (cr *cacheRecord) Parent() ImmutableRef {