@@ -118,7 +118,7 @@ google.golang.org/genproto                          694d95ba50e67b2e363f3483057d

 # containerd

 github.com/containerd/containerd                    36cf5b690dcc00ff0f34ff7799209050c3d0c59a # v1.3.0

-github.com/containerd/fifo                          a9fb20d87448d386e6d50b1f2e1fa70dcf0de43c

+github.com/containerd/fifo                          bda0ff6ed73c67bfb5e62bc9c697f146b7fd7f13

 github.com/containerd/continuity                    f2a389ac0a02ce21c09edd7344677a601970f41c

 github.com/containerd/cgroups                       c4b9ac5c7601384c965b9646fc515884e091ebb9

 github.com/containerd/console                       0650fd9eeb50bab4fc99dceb9f2e14cf58f36e7f

new file mode 100644

@@ -0,0 +1,30 @@

+/*

+   Copyright The containerd Authors.

+

+   Licensed under the Apache License, Version 2.0 (the "License");

+   you may not use this file except in compliance with the License.

+   You may obtain a copy of the License at

+

+       http://www.apache.org/licenses/LICENSE-2.0

+

+   Unless required by applicable law or agreed to in writing, software

+   distributed under the License is distributed on an "AS IS" BASIS,

+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

+   See the License for the specific language governing permissions and

+   limitations under the License.

+*/

+

+package fifo

+

+import (

+	"errors"

+)

+

+var (

+	ErrClosed       = errors.New("fifo closed")

+	ErrCtrlClosed   = errors.New("control of closed fifo")

+	ErrRdFrmWRONLY  = errors.New("reading from write-only fifo")

+	ErrReadClosed   = errors.New("reading from a closed fifo")

+	ErrWrToRDONLY   = errors.New("writing to read-only fifo")

+	ErrWriteClosed  = errors.New("writing to a closed fifo")

+)

@@ -147,7 +147,7 @@ func OpenFifo(ctx context.Context, fn string, flag int, perm os.FileMode) (io.Re

 // Read from a fifo to a byte array.

 func (f *fifo) Read(b []byte) (int, error) {

 	if f.flag&syscall.O_WRONLY > 0 {

-		return 0, errors.New("reading from write-only fifo")

+		return 0, ErrRdFrmWRONLY

 	}

 	select {

 	case <-f.opened:

@@ -158,14 +158,14 @@ func (f *fifo) Read(b []byte) (int, error) {

 	case <-f.opened:

 		return f.file.Read(b)

 	case <-f.closed:

-		return 0, errors.New("reading from a closed fifo")

+		return 0, ErrReadClosed

 	}

 }

 // Write from byte array to a fifo.

 func (f *fifo) Write(b []byte) (int, error) {

 	if f.flag&(syscall.O_WRONLY|syscall.O_RDWR) == 0 {

-		return 0, errors.New("writing to read-only fifo")

+		return 0, ErrWrToRDONLY

 	}

 	select {

 	case <-f.opened:

@@ -176,7 +176,7 @@ func (f *fifo) Write(b []byte) (int, error) {

 	case <-f.opened:

 		return f.file.Write(b)

 	case <-f.closed:

-		return 0, errors.New("writing to a closed fifo")

+		return 0, ErrWriteClosed

 	}

 }

@@ -20,8 +20,6 @@ package fifo

 import (

 	"syscall"

-

-	"github.com/pkg/errors"

 )

 // SyscallConn provides raw access to the fifo's underlying filedescrptor.

@@ -30,13 +28,13 @@ func (f *fifo) SyscallConn() (syscall.RawConn, error) {

 	// deterministic check for closed

 	select {

 	case <-f.closed:

-		return nil, errors.New("fifo closed")

+		return nil, ErrClosed

 	default:

 	}

 	select {

 	case <-f.closed:

-		return nil, errors.New("fifo closed")

+		return nil, ErrClosed

 	case <-f.opened:

 		return f.file.SyscallConn()

 	default:

@@ -68,7 +66,7 @@ type rawConn struct {

 func (r *rawConn) Control(f func(fd uintptr)) error {

 	select {

 	case <-r.f.closed:

-		return errors.New("control of closed fifo")

+		return ErrCtrlClosed

 	case <-r.ready:

 	}

@@ -81,12 +79,12 @@ func (r *rawConn) Control(f func(fd uintptr)) error {

 func (r *rawConn) Read(f func(fd uintptr) (done bool)) error {

 	if r.f.flag&syscall.O_WRONLY > 0 {

-		return errors.New("reading from write-only fifo")

+		return ErrRdFrmWRONLY

 	}

 	select {

 	case <-r.f.closed:

-		return errors.New("reading of a closed fifo")

+		return ErrReadClosed

 	case <-r.ready:

 	}

@@ -99,12 +97,12 @@ func (r *rawConn) Read(f func(fd uintptr) (done bool)) error {

 func (r *rawConn) Write(f func(fd uintptr) (done bool)) error {

 	if r.f.flag&(syscall.O_WRONLY|syscall.O_RDWR) == 0 {

-		return errors.New("writing to read-only fifo")

+		return ErrWrToRDONLY

 	}

 	select {

 	case <-r.f.closed:

-		return errors.New("writing to a closed fifo")

+		return ErrWriteClosed

 	case <-r.ready:

 	}