From 338e9a9be9aae9074d25637d3126f5b93531b6d1 Mon Sep 17 00:00:00 2001
From: Krishna Srinivas <634494+krishnasrinivas@users.noreply.github.com>
Date: Fri, 28 Jun 2019 22:09:17 -0700
Subject: [PATCH] Put object client disconnect (#7824)

Fail putObject  and postpolicy in case client prematurely disconnects
Use request's context to cancel lock requests on client disconnects
---
 cmd/bucket-handlers.go       |  3 +++
 cmd/config-migrate.go        |  4 ++--
 cmd/daily-sweeper.go         |  2 +-
 cmd/disk-cache-fs.go         |  4 ++--
 cmd/format-xl.go             |  2 +-
 cmd/fs-v1-multipart.go       |  2 +-
 cmd/fs-v1.go                 | 20 ++++++++++----------
 cmd/local-locker.go          |  2 +-
 cmd/lock-rest-client.go      |  2 +-
 cmd/lock-rest-client_test.go |  2 +-
 cmd/lock-rest-server.go      |  2 +-
 cmd/namespace-lock.go        | 23 ++++++++++++-----------
 cmd/namespace-lock_test.go   |  7 ++++---
 cmd/notification.go          |  6 +++---
 cmd/object-api-utils.go      | 15 +++++++++++++++
 cmd/object-handlers.go       |  3 +++
 cmd/server-main.go           |  2 +-
 cmd/utils.go                 |  2 +-
 cmd/xl-sets.go               |  8 ++++----
 cmd/xl-v1-bucket.go          |  4 ++--
 cmd/xl-v1-healing.go         |  2 +-
 cmd/xl-v1-multipart.go       | 14 +++++++-------
 cmd/xl-v1-object.go          | 12 ++++++------
 go.mod                       |  4 ++--
 go.sum                       | 15 ++++-----------
 25 files changed, 89 insertions(+), 73 deletions(-)

diff --git a/cmd/bucket-handlers.go b/cmd/bucket-handlers.go
index 9bf4f6e0d..e8b6c9e68 100644
--- a/cmd/bucket-handlers.go
+++ b/cmd/bucket-handlers.go
@@ -498,6 +498,9 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 
 	bucket := mux.Vars(r)["bucket"]
 
+	// To detect if the client has disconnected.
+	r.Body = &detectDisconnect{r.Body, r.Context().Done()}
+
 	// Require Content-Length to be set in the request
 	size := r.ContentLength
 	if size < 0 {
diff --git a/cmd/config-migrate.go b/cmd/config-migrate.go
index 6cf2205cc..028d22e0b 100644
--- a/cmd/config-migrate.go
+++ b/cmd/config-migrate.go
@@ -2440,7 +2440,7 @@ func migrateConfigToMinioSys(objAPI ObjectLayer) (err error) {
 	// As object layer's GetObject() and PutObject() take respective lock on minioMetaBucket
 	// and configFile, take a transaction lock to avoid data race between readConfig()
 	// and saveConfig().
-	objLock := globalNSMutex.NewNSLock(minioMetaBucket, transactionConfigFile)
+	objLock := globalNSMutex.NewNSLock(context.Background(), minioMetaBucket, transactionConfigFile)
 	if err = objLock.GetLock(globalOperationTimeout); err != nil {
 		return err
 	}
@@ -2492,7 +2492,7 @@ func migrateMinioSysConfig(objAPI ObjectLayer) error {
 	// As object layer's GetObject() and PutObject() take respective lock on minioMetaBucket
 	// and configFile, take a transaction lock to avoid data race between readConfig()
 	// and saveConfig().
-	objLock := globalNSMutex.NewNSLock(minioMetaBucket, transactionConfigFile)
+	objLock := globalNSMutex.NewNSLock(context.Background(), minioMetaBucket, transactionConfigFile)
 	if err := objLock.GetLock(globalOperationTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/daily-sweeper.go b/cmd/daily-sweeper.go
index 9ca790a78..e718622f6 100644
--- a/cmd/daily-sweeper.go
+++ b/cmd/daily-sweeper.go
@@ -55,7 +55,7 @@ func sweepRound(ctx context.Context, objAPI ObjectLayer) error {
 	zeroDynamicTimeout := newDynamicTimeout(zeroDuration, zeroDuration)
 
 	// General lock so we avoid parallel daily sweep by different instances.
-	sweepLock := globalNSMutex.NewNSLock("system", "daily-sweep")
+	sweepLock := globalNSMutex.NewNSLock(ctx, "system", "daily-sweep")
 	if err := sweepLock.GetLock(zeroDynamicTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/disk-cache-fs.go b/cmd/disk-cache-fs.go
index 46ec572d0..18aa2d1c8 100644
--- a/cmd/disk-cache-fs.go
+++ b/cmd/disk-cache-fs.go
@@ -303,7 +303,7 @@ func (cfs *cacheFSObjects) PutObject(ctx context.Context, bucket string, object
 	data := r.Reader
 	fs := cfs.FSObjects
 	// Lock the object.
-	objectLock := fs.nsMutex.NewNSLock(bucket, object)
+	objectLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetLock(globalObjectTimeout); err != nil {
 		return objInfo, err
 	}
@@ -489,7 +489,7 @@ func (cfs *cacheFSObjects) NewMultipartUpload(ctx context.Context, bucket, objec
 // moveBucketToTrash clears cacheFSObjects of bucket contents and moves it to trash folder.
 func (cfs *cacheFSObjects) moveBucketToTrash(ctx context.Context, bucket string) (err error) {
 	fs := cfs.FSObjects
-	bucketLock := fs.nsMutex.NewNSLock(bucket, "")
+	bucketLock := fs.nsMutex.NewNSLock(ctx, bucket, "")
 	if err = bucketLock.GetLock(globalObjectTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/format-xl.go b/cmd/format-xl.go
index 31c7c64f1..447752292 100644
--- a/cmd/format-xl.go
+++ b/cmd/format-xl.go
@@ -491,7 +491,7 @@ func formatXLGetDeploymentID(refFormat *formatXLV3, formats []*formatXLV3) (stri
 func formatXLFixDeploymentID(ctx context.Context, endpoints EndpointList, storageDisks []StorageAPI, refFormat *formatXLV3) (err error) {
 	// Acquire lock on format.json
 	mutex := newNSLock(globalIsDistXL)
-	formatLock := mutex.NewNSLock(minioMetaBucket, formatConfigFile)
+	formatLock := mutex.NewNSLock(ctx, minioMetaBucket, formatConfigFile)
 	if err = formatLock.GetLock(globalHealingTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/fs-v1-multipart.go b/cmd/fs-v1-multipart.go
index f6d026cb6..0f66be404 100644
--- a/cmd/fs-v1-multipart.go
+++ b/cmd/fs-v1-multipart.go
@@ -634,7 +634,7 @@ func (fs *FSObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 	}
 
 	// Hold write lock on the object.
-	destLock := fs.nsMutex.NewNSLock(bucket, object)
+	destLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 	if err = destLock.GetLock(globalObjectTimeout); err != nil {
 		return oi, err
 	}
diff --git a/cmd/fs-v1.go b/cmd/fs-v1.go
index 858da8a9f..c44ed072b 100644
--- a/cmd/fs-v1.go
+++ b/cmd/fs-v1.go
@@ -286,7 +286,7 @@ func (fs *FSObjects) statBucketDir(ctx context.Context, bucket string) (os.FileI
 // MakeBucketWithLocation - create a new bucket, returns if it
 // already exists.
 func (fs *FSObjects) MakeBucketWithLocation(ctx context.Context, bucket, location string) error {
-	bucketLock := fs.nsMutex.NewNSLock(bucket, "")
+	bucketLock := fs.nsMutex.NewNSLock(ctx, bucket, "")
 	if err := bucketLock.GetLock(globalObjectTimeout); err != nil {
 		return err
 	}
@@ -309,7 +309,7 @@ func (fs *FSObjects) MakeBucketWithLocation(ctx context.Context, bucket, locatio
 
 // GetBucketInfo - fetch bucket metadata info.
 func (fs *FSObjects) GetBucketInfo(ctx context.Context, bucket string) (bi BucketInfo, e error) {
-	bucketLock := fs.nsMutex.NewNSLock(bucket, "")
+	bucketLock := fs.nsMutex.NewNSLock(ctx, bucket, "")
 	if e := bucketLock.GetRLock(globalObjectTimeout); e != nil {
 		return bi, e
 	}
@@ -372,7 +372,7 @@ func (fs *FSObjects) ListBuckets(ctx context.Context) ([]BucketInfo, error) {
 // DeleteBucket - delete a bucket and all the metadata associated
 // with the bucket including pending multipart, object metadata.
 func (fs *FSObjects) DeleteBucket(ctx context.Context, bucket string) error {
-	bucketLock := fs.nsMutex.NewNSLock(bucket, "")
+	bucketLock := fs.nsMutex.NewNSLock(ctx, bucket, "")
 	if err := bucketLock.GetLock(globalObjectTimeout); err != nil {
 		logger.LogIf(ctx, err)
 		return err
@@ -408,7 +408,7 @@ func (fs *FSObjects) DeleteBucket(ctx context.Context, bucket string) error {
 func (fs *FSObjects) CopyObject(ctx context.Context, srcBucket, srcObject, dstBucket, dstObject string, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (oi ObjectInfo, e error) {
 	cpSrcDstSame := isStringEqual(pathJoin(srcBucket, srcObject), pathJoin(dstBucket, dstObject))
 	if !cpSrcDstSame {
-		objectDWLock := fs.nsMutex.NewNSLock(dstBucket, dstObject)
+		objectDWLock := fs.nsMutex.NewNSLock(ctx, dstBucket, dstObject)
 		if err := objectDWLock.GetLock(globalObjectTimeout); err != nil {
 			return oi, err
 		}
@@ -480,7 +480,7 @@ func (fs *FSObjects) GetObjectNInfo(ctx context.Context, bucket, object string,
 
 	if lockType != noLock {
 		// Lock the object before reading.
-		lock := fs.nsMutex.NewNSLock(bucket, object)
+		lock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 		switch lockType {
 		case writeLock:
 			if err = lock.GetLock(globalObjectTimeout); err != nil {
@@ -567,7 +567,7 @@ func (fs *FSObjects) GetObject(ctx context.Context, bucket, object string, offse
 	}
 
 	// Lock the object before reading.
-	objectLock := fs.nsMutex.NewNSLock(bucket, object)
+	objectLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetRLock(globalObjectTimeout); err != nil {
 		logger.LogIf(ctx, err)
 		return err
@@ -739,7 +739,7 @@ func (fs *FSObjects) getObjectInfo(ctx context.Context, bucket, object string) (
 // getObjectInfoWithLock - reads object metadata and replies back ObjectInfo.
 func (fs *FSObjects) getObjectInfoWithLock(ctx context.Context, bucket, object string) (oi ObjectInfo, e error) {
 	// Lock the object before reading.
-	objectLock := fs.nsMutex.NewNSLock(bucket, object)
+	objectLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetRLock(globalObjectTimeout); err != nil {
 		return oi, err
 	}
@@ -764,7 +764,7 @@ func (fs *FSObjects) getObjectInfoWithLock(ctx context.Context, bucket, object s
 func (fs *FSObjects) GetObjectInfo(ctx context.Context, bucket, object string, opts ObjectOptions) (oi ObjectInfo, e error) {
 	oi, err := fs.getObjectInfoWithLock(ctx, bucket, object)
 	if err == errCorruptedFormat || err == io.EOF {
-		objectLock := fs.nsMutex.NewNSLock(bucket, object)
+		objectLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 		if err = objectLock.GetLock(globalObjectTimeout); err != nil {
 			return oi, toObjectErr(err, bucket, object)
 		}
@@ -810,7 +810,7 @@ func (fs *FSObjects) PutObject(ctx context.Context, bucket string, object string
 		return ObjectInfo{}, err
 	}
 	// Lock the object.
-	objectLock := fs.nsMutex.NewNSLock(bucket, object)
+	objectLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetLock(globalObjectTimeout); err != nil {
 		logger.LogIf(ctx, err)
 		return objInfo, err
@@ -965,7 +965,7 @@ func (fs *FSObjects) DeleteObjects(ctx context.Context, bucket string, objects [
 // and there are no rollbacks supported.
 func (fs *FSObjects) DeleteObject(ctx context.Context, bucket, object string) error {
 	// Acquire a write lock before deleting the object.
-	objectLock := fs.nsMutex.NewNSLock(bucket, object)
+	objectLock := fs.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetLock(globalOperationTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/local-locker.go b/cmd/local-locker.go
index 1b7150b51..960dd001c 100644
--- a/cmd/local-locker.go
+++ b/cmd/local-locker.go
@@ -21,7 +21,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/minio/dsync"
+	"github.com/minio/dsync/v2"
 )
 
 // lockRequesterInfo stores various info from the client for each lock that is requested.
diff --git a/cmd/lock-rest-client.go b/cmd/lock-rest-client.go
index c24322f0c..bdac5daee 100644
--- a/cmd/lock-rest-client.go
+++ b/cmd/lock-rest-client.go
@@ -28,7 +28,7 @@ import (
 
 	"net/url"
 
-	"github.com/minio/dsync"
+	"github.com/minio/dsync/v2"
 	"github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/cmd/rest"
diff --git a/cmd/lock-rest-client_test.go b/cmd/lock-rest-client_test.go
index 4ac04066c..05612848f 100644
--- a/cmd/lock-rest-client_test.go
+++ b/cmd/lock-rest-client_test.go
@@ -19,7 +19,7 @@ package cmd
 import (
 	"testing"
 
-	"github.com/minio/dsync"
+	"github.com/minio/dsync/v2"
 	xnet "github.com/minio/minio/pkg/net"
 )
 
diff --git a/cmd/lock-rest-server.go b/cmd/lock-rest-server.go
index 80c77aa69..1ce80e34b 100644
--- a/cmd/lock-rest-server.go
+++ b/cmd/lock-rest-server.go
@@ -25,7 +25,7 @@ import (
 	"time"
 
 	"github.com/gorilla/mux"
-	"github.com/minio/dsync"
+	"github.com/minio/dsync/v2"
 	"github.com/minio/minio/cmd/logger"
 	xnet "github.com/minio/minio/pkg/net"
 )
diff --git a/cmd/namespace-lock.go b/cmd/namespace-lock.go
index 83920b3a7..65f3c8e60 100644
--- a/cmd/namespace-lock.go
+++ b/cmd/namespace-lock.go
@@ -27,7 +27,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/minio/dsync"
+	"github.com/minio/dsync/v2"
 	"github.com/minio/lsync"
 	"github.com/minio/minio-go/v6/pkg/set"
 	"github.com/minio/minio/cmd/logger"
@@ -127,7 +127,7 @@ type nsLockMap struct {
 }
 
 // Lock the namespace resource.
-func (n *nsLockMap) lock(volume, path string, lockSource, opsID string, readLock bool, timeout time.Duration) (locked bool) {
+func (n *nsLockMap) lock(ctx context.Context, volume, path string, lockSource, opsID string, readLock bool, timeout time.Duration) (locked bool) {
 	var nsLk *nsLock
 
 	n.lockMapMutex.Lock()
@@ -135,7 +135,7 @@ func (n *nsLockMap) lock(volume, path string, lockSource, opsID string, readLock
 	nsLk, found := n.lockMap[param]
 	if !found {
 		n.lockMap[param] = &nsLock{
-			LRWMutex: &lsync.LRWMutex{},
+			LRWMutex: lsync.NewLRWMutex(ctx),
 			ref:      1,
 		}
 		nsLk = n.lockMap[param]
@@ -199,7 +199,7 @@ func (n *nsLockMap) Lock(volume, path, opsID string, timeout time.Duration) (loc
 	readLock := false // This is a write lock.
 
 	lockSource := getSource() // Useful for debugging
-	return n.lock(volume, path, lockSource, opsID, readLock, timeout)
+	return n.lock(context.Background(), volume, path, lockSource, opsID, readLock, timeout)
 }
 
 // Unlock - unlocks any previously acquired write locks.
@@ -213,7 +213,7 @@ func (n *nsLockMap) RLock(volume, path, opsID string, timeout time.Duration) (lo
 	readLock := true
 
 	lockSource := getSource() // Useful for debugging
-	return n.lock(volume, path, lockSource, opsID, readLock, timeout)
+	return n.lock(context.Background(), volume, path, lockSource, opsID, readLock, timeout)
 }
 
 // RUnlock - unlocks any previously acquired read locks.
@@ -241,7 +241,7 @@ func (n *nsLockMap) ForceUnlock(volume, path string) {
 	//   are blocking can now proceed as normal and any new locks will also
 	//   participate normally.
 	if n.isDistXL { // For distributed mode, broadcast ForceUnlock message.
-		dsync.NewDRWMutex(pathJoin(volume, path), globalDsync).ForceUnlock()
+		dsync.NewDRWMutex(context.Background(), pathJoin(volume, path), globalDsync).ForceUnlock()
 	}
 
 	// Remove lock from the map.
@@ -291,6 +291,7 @@ func (di *distLockInstance) RUnlock() {
 
 // localLockInstance - frontend/top-level interface for namespace locks.
 type localLockInstance struct {
+	ctx                 context.Context
 	ns                  *nsLockMap
 	volume, path, opsID string
 }
@@ -298,12 +299,12 @@ type localLockInstance struct {
 // NewNSLock - returns a lock instance for a given volume and
 // path. The returned lockInstance object encapsulates the nsLockMap,
 // volume, path and operation ID.
-func (n *nsLockMap) NewNSLock(volume, path string) RWLocker {
+func (n *nsLockMap) NewNSLock(ctx context.Context, volume, path string) RWLocker {
 	opsID := mustGetUUID()
 	if n.isDistXL {
-		return &distLockInstance{dsync.NewDRWMutex(pathJoin(volume, path), globalDsync), volume, path, opsID}
+		return &distLockInstance{dsync.NewDRWMutex(ctx, pathJoin(volume, path), globalDsync), volume, path, opsID}
 	}
-	return &localLockInstance{n, volume, path, opsID}
+	return &localLockInstance{ctx, n, volume, path, opsID}
 }
 
 // Lock - block until write lock is taken or timeout has occurred.
@@ -311,7 +312,7 @@ func (li *localLockInstance) GetLock(timeout *dynamicTimeout) (timedOutErr error
 	lockSource := getSource()
 	start := UTCNow()
 	readLock := false
-	if !li.ns.lock(li.volume, li.path, lockSource, li.opsID, readLock, timeout.Timeout()) {
+	if !li.ns.lock(li.ctx, li.volume, li.path, lockSource, li.opsID, readLock, timeout.Timeout()) {
 		timeout.LogFailure()
 		return OperationTimedOut{Path: li.path}
 	}
@@ -330,7 +331,7 @@ func (li *localLockInstance) GetRLock(timeout *dynamicTimeout) (timedOutErr erro
 	lockSource := getSource()
 	start := UTCNow()
 	readLock := true
-	if !li.ns.lock(li.volume, li.path, lockSource, li.opsID, readLock, timeout.Timeout()) {
+	if !li.ns.lock(li.ctx, li.volume, li.path, lockSource, li.opsID, readLock, timeout.Timeout()) {
 		timeout.LogFailure()
 		return OperationTimedOut{Path: li.path}
 	}
diff --git a/cmd/namespace-lock_test.go b/cmd/namespace-lock_test.go
index fd9125cbe..52838356b 100644
--- a/cmd/namespace-lock_test.go
+++ b/cmd/namespace-lock_test.go
@@ -17,6 +17,7 @@
 package cmd
 
 import (
+	"context"
 	"testing"
 	"time"
 )
@@ -31,7 +32,7 @@ func TestGetSource(t *testing.T) {
 	currentSource := func() string { return getSource() }
 	gotSource := currentSource()
 	// Hard coded line number, 32, in the "expectedSource" value
-	expectedSource := "[namespace-lock_test.go:32:TestGetSource()]"
+	expectedSource := "[namespace-lock_test.go:33:TestGetSource()]"
 	if gotSource != expectedSource {
 		t.Errorf("expected : %s, got : %s", expectedSource, gotSource)
 	}
@@ -204,7 +205,7 @@ func TestNamespaceForceUnlockTest(t *testing.T) {
 	isDistXL := false
 	initNSLock(isDistXL)
 	// Create lock.
-	lock := globalNSMutex.NewNSLock("bucket", "object")
+	lock := globalNSMutex.NewNSLock(context.Background(), "bucket", "object")
 	if lock.GetLock(newDynamicTimeout(60*time.Second, time.Second)) != nil {
 		t.Fatalf("Failed to get lock")
 	}
@@ -215,7 +216,7 @@ func TestNamespaceForceUnlockTest(t *testing.T) {
 
 	go func() {
 		// Try to claim lock again.
-		anotherLock := globalNSMutex.NewNSLock("bucket", "object")
+		anotherLock := globalNSMutex.NewNSLock(context.Background(), "bucket", "object")
 		if anotherLock.GetLock(newDynamicTimeout(60*time.Second, time.Second)) != nil {
 			t.Errorf("Failed to get lock")
 			return
diff --git a/cmd/notification.go b/cmd/notification.go
index d965e14b2..751aec33d 100644
--- a/cmd/notification.go
+++ b/cmd/notification.go
@@ -602,7 +602,7 @@ func (sys *NotificationSys) initListeners(ctx context.Context, objAPI ObjectLaye
 	// As object layer's GetObject() and PutObject() take respective lock on minioMetaBucket
 	// and configFile, take a transaction lock to avoid data race between readConfig()
 	// and saveConfig().
-	objLock := globalNSMutex.NewNSLock(minioMetaBucket, transactionConfigFile)
+	objLock := globalNSMutex.NewNSLock(ctx, minioMetaBucket, transactionConfigFile)
 	if err := objLock.GetRLock(globalOperationTimeout); err != nil {
 		return err
 	}
@@ -1058,7 +1058,7 @@ func SaveListener(objAPI ObjectLayer, bucketName string, eventNames []event.Name
 	// As object layer's GetObject() and PutObject() take respective lock on minioMetaBucket
 	// and configFile, take a transaction lock to avoid data race between readConfig()
 	// and saveConfig().
-	objLock := globalNSMutex.NewNSLock(minioMetaBucket, transactionConfigFile)
+	objLock := globalNSMutex.NewNSLock(ctx, minioMetaBucket, transactionConfigFile)
 	if err := objLock.GetLock(globalOperationTimeout); err != nil {
 		return err
 	}
@@ -1109,7 +1109,7 @@ func RemoveListener(objAPI ObjectLayer, bucketName string, targetID event.Target
 	// As object layer's GetObject() and PutObject() take respective lock on minioMetaBucket
 	// and configFile, take a transaction lock to avoid data race between readConfig()
 	// and saveConfig().
-	objLock := globalNSMutex.NewNSLock(minioMetaBucket, transactionConfigFile)
+	objLock := globalNSMutex.NewNSLock(ctx, minioMetaBucket, transactionConfigFile)
 	if err := objLock.GetLock(globalOperationTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/object-api-utils.go b/cmd/object-api-utils.go
index 98d087ca1..338494d4f 100644
--- a/cmd/object-api-utils.go
+++ b/cmd/object-api-utils.go
@@ -793,3 +793,18 @@ func (cr *snappyCompressReader) Read(p []byte) (int, error) {
 	}
 	return n, err
 }
+
+// Returns error if the cancelCh has been closed (indicating that S3 client has disconnected)
+type detectDisconnect struct {
+	io.ReadCloser
+	cancelCh <-chan struct{}
+}
+
+func (d *detectDisconnect) Read(p []byte) (int, error) {
+	select {
+	case <-d.cancelCh:
+		return 0, io.ErrUnexpectedEOF
+	default:
+		return d.ReadCloser.Read(p)
+	}
+}
diff --git a/cmd/object-handlers.go b/cmd/object-handlers.go
index 02aeaff3a..7785c022b 100644
--- a/cmd/object-handlers.go
+++ b/cmd/object-handlers.go
@@ -1064,6 +1064,9 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 	bucket := vars["bucket"]
 	object := vars["object"]
 
+	// To detect if the client has disconnected.
+	r.Body = &detectDisconnect{r.Body, r.Context().Done()}
+
 	// X-Amz-Copy-Source shouldn't be set for this call.
 	if _, ok := r.Header["X-Amz-Copy-Source"]; ok {
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidCopySource), r.URL, guessIsBrowserReq(r))
diff --git a/cmd/server-main.go b/cmd/server-main.go
index 76b5eec92..8237472f5 100644
--- a/cmd/server-main.go
+++ b/cmd/server-main.go
@@ -27,7 +27,7 @@ import (
 	"syscall"
 
 	"github.com/minio/cli"
-	"github.com/minio/dsync"
+	"github.com/minio/dsync/v2"
 	xhttp "github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/certs"
diff --git a/cmd/utils.go b/cmd/utils.go
index 5fb01d6bc..70eac2546 100644
--- a/cmd/utils.go
+++ b/cmd/utils.go
@@ -433,7 +433,7 @@ func newContext(r *http.Request, w http.ResponseWriter, api string) context.Cont
 		BucketName:   bucket,
 		ObjectName:   object,
 	}
-	return logger.SetReqInfo(context.Background(), reqInfo)
+	return logger.SetReqInfo(r.Context(), reqInfo)
 }
 
 // isNetworkOrHostDown - if there was a network error or if the host is down.
diff --git a/cmd/xl-sets.go b/cmd/xl-sets.go
index b5071d839..b933205b7 100644
--- a/cmd/xl-sets.go
+++ b/cmd/xl-sets.go
@@ -686,7 +686,7 @@ func (s *xlSets) CopyObject(ctx context.Context, srcBucket, srcObject, destBucke
 	}
 
 	if !cpSrcDstSame {
-		objectDWLock := destSet.nsMutex.NewNSLock(destBucket, destObject)
+		objectDWLock := destSet.nsMutex.NewNSLock(ctx, destBucket, destObject)
 		if err := objectDWLock.GetLock(globalObjectTimeout); err != nil {
 			return objInfo, err
 		}
@@ -1157,7 +1157,7 @@ func formatsToDrivesInfo(endpoints EndpointList, formats []*formatXLV3, sErrs []
 // healing in a distributed setup.
 func (s *xlSets) ReloadFormat(ctx context.Context, dryRun bool) (err error) {
 	// Acquire lock on format.json
-	formatLock := s.getHashedSet(formatConfigFile).nsMutex.NewNSLock(minioMetaBucket, formatConfigFile)
+	formatLock := s.getHashedSet(formatConfigFile).nsMutex.NewNSLock(ctx, minioMetaBucket, formatConfigFile)
 	if err = formatLock.GetRLock(globalHealingTimeout); err != nil {
 		return err
 	}
@@ -1278,7 +1278,7 @@ func markRootDisksAsDown(storageDisks []StorageAPI) {
 // coded data in it.
 func (s *xlSets) HealFormat(ctx context.Context, dryRun bool) (res madmin.HealResultItem, err error) {
 	// Acquire lock on format.json
-	formatLock := s.getHashedSet(formatConfigFile).nsMutex.NewNSLock(minioMetaBucket, formatConfigFile)
+	formatLock := s.getHashedSet(formatConfigFile).nsMutex.NewNSLock(ctx, minioMetaBucket, formatConfigFile)
 	if err = formatLock.GetLock(globalHealingTimeout); err != nil {
 		return madmin.HealResultItem{}, err
 	}
@@ -1431,7 +1431,7 @@ func (s *xlSets) HealFormat(ctx context.Context, dryRun bool) (res madmin.HealRe
 
 // HealBucket - heals inconsistent buckets and bucket metadata on all sets.
 func (s *xlSets) HealBucket(ctx context.Context, bucket string, dryRun, remove bool) (result madmin.HealResultItem, err error) {
-	bucketLock := globalNSMutex.NewNSLock(bucket, "")
+	bucketLock := globalNSMutex.NewNSLock(ctx, bucket, "")
 	if err := bucketLock.GetLock(globalHealingTimeout); err != nil {
 		return result, err
 	}
diff --git a/cmd/xl-v1-bucket.go b/cmd/xl-v1-bucket.go
index 09f05051d..0a96a0721 100644
--- a/cmd/xl-v1-bucket.go
+++ b/cmd/xl-v1-bucket.go
@@ -151,7 +151,7 @@ func (xl xlObjects) getBucketInfo(ctx context.Context, bucketName string) (bucke
 
 // GetBucketInfo - returns BucketInfo for a bucket.
 func (xl xlObjects) GetBucketInfo(ctx context.Context, bucket string) (bi BucketInfo, e error) {
-	bucketLock := xl.nsMutex.NewNSLock(bucket, "")
+	bucketLock := xl.nsMutex.NewNSLock(ctx, bucket, "")
 	if e := bucketLock.GetRLock(globalObjectTimeout); e != nil {
 		return bi, e
 	}
@@ -237,7 +237,7 @@ func deleteDanglingBucket(ctx context.Context, storageDisks []StorageAPI, dErrs
 
 // DeleteBucket - deletes a bucket.
 func (xl xlObjects) DeleteBucket(ctx context.Context, bucket string) error {
-	bucketLock := xl.nsMutex.NewNSLock(bucket, "")
+	bucketLock := xl.nsMutex.NewNSLock(ctx, bucket, "")
 	if err := bucketLock.GetLock(globalObjectTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/xl-v1-healing.go b/cmd/xl-v1-healing.go
index 380397998..f99dddbc9 100644
--- a/cmd/xl-v1-healing.go
+++ b/cmd/xl-v1-healing.go
@@ -717,7 +717,7 @@ func (xl xlObjects) HealObject(ctx context.Context, bucket, object string, dryRu
 	}
 
 	// Lock the object before healing.
-	objectLock := xl.nsMutex.NewNSLock(bucket, object)
+	objectLock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 	if lerr := objectLock.GetRLock(globalHealingTimeout); lerr != nil {
 		return defaultHealResult(latestXLMeta, storageDisks, errs, bucket, object), lerr
 	}
diff --git a/cmd/xl-v1-multipart.go b/cmd/xl-v1-multipart.go
index f9013002c..2f9b352cf 100644
--- a/cmd/xl-v1-multipart.go
+++ b/cmd/xl-v1-multipart.go
@@ -258,7 +258,7 @@ func (xl xlObjects) NewMultipartUpload(ctx context.Context, bucket, object strin
 func (xl xlObjects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, dstBucket, dstObject, uploadID string, partID int, startOffset int64, length int64, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (pi PartInfo, e error) {
 	// Hold read locks on source object only if we are
 	// going to read data from source object.
-	objectSRLock := xl.nsMutex.NewNSLock(srcBucket, srcObject)
+	objectSRLock := xl.nsMutex.NewNSLock(ctx, srcBucket, srcObject)
 	if err := objectSRLock.GetRLock(globalObjectTimeout); err != nil {
 		return pi, err
 	}
@@ -300,7 +300,7 @@ func (xl xlObjects) PutObjectPart(ctx context.Context, bucket, object, uploadID
 	uploadIDLockPath := xl.getUploadIDLockPath(bucket, object, uploadID)
 
 	// pre-check upload id lock.
-	preUploadIDLock := xl.nsMutex.NewNSLock(minioMetaMultipartBucket, uploadIDLockPath)
+	preUploadIDLock := xl.nsMutex.NewNSLock(ctx, minioMetaMultipartBucket, uploadIDLockPath)
 	if err := preUploadIDLock.GetRLock(globalOperationTimeout); err != nil {
 		return pi, err
 	}
@@ -398,7 +398,7 @@ func (xl xlObjects) PutObjectPart(ctx context.Context, bucket, object, uploadID
 	}
 
 	// post-upload check (write) lock
-	postUploadIDLock := xl.nsMutex.NewNSLock(minioMetaMultipartBucket, uploadIDLockPath)
+	postUploadIDLock := xl.nsMutex.NewNSLock(ctx, minioMetaMultipartBucket, uploadIDLockPath)
 	if err = postUploadIDLock.GetLock(globalOperationTimeout); err != nil {
 		return pi, err
 	}
@@ -492,7 +492,7 @@ func (xl xlObjects) ListObjectParts(ctx context.Context, bucket, object, uploadI
 	}
 	// Hold lock so that there is no competing
 	// abort-multipart-upload or complete-multipart-upload.
-	uploadIDLock := xl.nsMutex.NewNSLock(minioMetaMultipartBucket,
+	uploadIDLock := xl.nsMutex.NewNSLock(ctx, minioMetaMultipartBucket,
 		xl.getUploadIDLockPath(bucket, object, uploadID))
 	if err := uploadIDLock.GetLock(globalListingTimeout); err != nil {
 		return result, err
@@ -596,7 +596,7 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 		return oi, err
 	}
 	// Hold write lock on the object.
-	destLock := xl.nsMutex.NewNSLock(bucket, object)
+	destLock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := destLock.GetLock(globalObjectTimeout); err != nil {
 		return oi, err
 	}
@@ -611,7 +611,7 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 	//
 	// 2) no one does a parallel complete-multipart-upload on this
 	// multipart upload
-	uploadIDLock := xl.nsMutex.NewNSLock(minioMetaMultipartBucket, uploadIDLockPath)
+	uploadIDLock := xl.nsMutex.NewNSLock(ctx, minioMetaMultipartBucket, uploadIDLockPath)
 	if err := uploadIDLock.GetLock(globalOperationTimeout); err != nil {
 		return oi, err
 	}
@@ -815,7 +815,7 @@ func (xl xlObjects) AbortMultipartUpload(ctx context.Context, bucket, object, up
 	uploadIDLockPath := xl.getUploadIDLockPath(bucket, object, uploadID)
 	// Hold lock so that there is no competing
 	// complete-multipart-upload or put-object-part.
-	uploadIDLock := xl.nsMutex.NewNSLock(minioMetaMultipartBucket, uploadIDLockPath)
+	uploadIDLock := xl.nsMutex.NewNSLock(ctx, minioMetaMultipartBucket, uploadIDLockPath)
 	if err := uploadIDLock.GetLock(globalOperationTimeout); err != nil {
 		return err
 	}
diff --git a/cmd/xl-v1-object.go b/cmd/xl-v1-object.go
index 15511d511..be54d3083 100644
--- a/cmd/xl-v1-object.go
+++ b/cmd/xl-v1-object.go
@@ -125,7 +125,7 @@ func (xl xlObjects) GetObjectNInfo(ctx context.Context, bucket, object string, r
 
 	// Acquire lock
 	if lockType != noLock {
-		lock := xl.nsMutex.NewNSLock(bucket, object)
+		lock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 		switch lockType {
 		case writeLock:
 			if err = lock.GetLock(globalObjectTimeout); err != nil {
@@ -188,7 +188,7 @@ func (xl xlObjects) GetObjectNInfo(ctx context.Context, bucket, object string, r
 // length indicates the total length of the object.
 func (xl xlObjects) GetObject(ctx context.Context, bucket, object string, startOffset int64, length int64, writer io.Writer, etag string, opts ObjectOptions) error {
 	// Lock the object before reading.
-	objectLock := xl.nsMutex.NewNSLock(bucket, object)
+	objectLock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetRLock(globalObjectTimeout); err != nil {
 		return err
 	}
@@ -369,7 +369,7 @@ func (xl xlObjects) getObjectInfoDir(ctx context.Context, bucket, object string)
 // GetObjectInfo - reads object metadata and replies back ObjectInfo.
 func (xl xlObjects) GetObjectInfo(ctx context.Context, bucket, object string, opts ObjectOptions) (oi ObjectInfo, e error) {
 	// Lock the object before reading.
-	objectLock := xl.nsMutex.NewNSLock(bucket, object)
+	objectLock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetRLock(globalObjectTimeout); err != nil {
 		return oi, err
 	}
@@ -504,7 +504,7 @@ func (xl xlObjects) PutObject(ctx context.Context, bucket string, object string,
 	}
 
 	// Lock the object.
-	objectLock := xl.nsMutex.NewNSLock(bucket, object)
+	objectLock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 	if err := objectLock.GetLock(globalObjectTimeout); err != nil {
 		return objInfo, err
 	}
@@ -857,7 +857,7 @@ func (xl xlObjects) deleteObjects(ctx context.Context, bucket string, objects []
 			continue
 		}
 		// Acquire a write lock before deleting the object.
-		objectLocks[i] = xl.nsMutex.NewNSLock(bucket, object)
+		objectLocks[i] = xl.nsMutex.NewNSLock(ctx, bucket, object)
 		if errs[i] = objectLocks[i].GetLock(globalOperationTimeout); errs[i] != nil {
 			continue
 		}
@@ -961,7 +961,7 @@ func (xl xlObjects) DeleteObjects(ctx context.Context, bucket string, objects []
 // response to the client request.
 func (xl xlObjects) DeleteObject(ctx context.Context, bucket, object string) (err error) {
 	// Acquire a write lock before deleting the object.
-	objectLock := xl.nsMutex.NewNSLock(bucket, object)
+	objectLock := xl.nsMutex.NewNSLock(ctx, bucket, object)
 	if perr := objectLock.GetLock(globalOperationTimeout); perr != nil {
 		return perr
 	}
diff --git a/go.mod b/go.mod
index 174fd2b3d..775c336d8 100644
--- a/go.mod
+++ b/go.mod
@@ -53,10 +53,10 @@ require (
 	github.com/miekg/dns v1.1.8
 	github.com/minio/blazer v0.0.0-20171126203752-2081f5bf0465
 	github.com/minio/cli v1.20.0
-	github.com/minio/dsync v1.0.0
+	github.com/minio/dsync/v2 v2.0.0
 	github.com/minio/hdfs/v3 v3.0.0
 	github.com/minio/highwayhash v1.0.0
-	github.com/minio/lsync v0.1.0
+	github.com/minio/lsync v1.0.1
 	github.com/minio/mc v0.0.0-20190529152718-f4bb0b8850cb
 	github.com/minio/minio-go/v6 v6.0.29
 	github.com/minio/parquet-go v0.0.0-20190318185229-9d767baf1679
diff --git a/go.sum b/go.sum
index b73110046..7536af835 100644
--- a/go.sum
+++ b/go.sum
@@ -411,6 +411,8 @@ github.com/minio/cli v1.20.0/go.mod h1:bYxnK0uS629N3Bq+AOZZ+6lwF77Sodk4+UL9vNuXh
 github.com/minio/dsync v0.0.0-20190104003057-61c41ffdeea2/go.mod h1:eLQe3mXL0h02kNpPtBJiLr1fIEIJftgXRAjncjQbxJo=
 github.com/minio/dsync v1.0.0 h1:l6pQgUPBM41idlR0UOcpAP+EYim9MCwIAUh6sQQI1gk=
 github.com/minio/dsync v1.0.0/go.mod h1:eLQe3mXL0h02kNpPtBJiLr1fIEIJftgXRAjncjQbxJo=
+github.com/minio/dsync/v2 v2.0.0 h1:p353BZ9od4xgHSXHn5GQ9V3WcnsxqH6aaShy0jDSX54=
+github.com/minio/dsync/v2 v2.0.0/go.mod h1:kxZSSQoDZa5OAsfgM8JJ0iRQOkGsg0op9unAnQVMm7o=
 github.com/minio/hdfs/v3 v3.0.0 h1:yHa9ugB2UeazkiphO6Q2dmbqiKR5lZssN/1vda4gwoY=
 github.com/minio/hdfs/v3 v3.0.0/go.mod h1:k04lEYpgeojX3o1vQep6rQs4MCTD+qlh2xHFEa/BH6A=
 github.com/minio/highwayhash v0.0.0-20181220011308-93ed73d64169/go.mod h1:NL8wme5P5MoscwAkXfGroz3VgpCdhBw3KYOu5mEsvpU=
@@ -420,6 +422,8 @@ github.com/minio/lsync v0.0.0-20190207022115-a4e43e3d0887 h1:MIpCDz3d2FR2a+Fjdiz
 github.com/minio/lsync v0.0.0-20190207022115-a4e43e3d0887/go.mod h1:ni10+iSX7FO8N2rv41XM444V6w4rYO0dZo5KIkbn/YA=
 github.com/minio/lsync v0.1.0 h1:VczQvieoFS1Ayyxw6RhODkqN/UhMQXom14oJuSbR7vo=
 github.com/minio/lsync v0.1.0/go.mod h1:ni10+iSX7FO8N2rv41XM444V6w4rYO0dZo5KIkbn/YA=
+github.com/minio/lsync v1.0.1 h1:AVvILxA976xc27hstd1oR+X9PQG0sPSom1MNb1ImfUs=
+github.com/minio/lsync v1.0.1/go.mod h1:tCFzfo0dlvdGl70IT4IAK/5Wtgb0/BrTmo/jE8pArKA=
 github.com/minio/mc v0.0.0-20190311071728-2e612b23d665/go.mod h1:7qLZXNjCD55DJ3iqe1uWoUh1MASRVd1M6wnqSdyhx7Y=
 github.com/minio/mc v0.0.0-20190401030144-a1355e50e2e8 h1:npKHywsxVECDu+YHfR8Sswm3giEdRbCcLRSYudE3UxQ=
 github.com/minio/mc v0.0.0-20190401030144-a1355e50e2e8/go.mod h1:rnJByweU1h98rGmAcWcKen1sCAlekF38kbSrq6OLmAg=
@@ -679,8 +683,6 @@ golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f h1:R423Cnkcp5JABoeemiGEPlt9tHXFfw5kvc0yqlxRPWo=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 h1:1wopBVtVdWnn03fZelqdXTqk7U7zPQCb+T4rbU9ZEoU=
-golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443 h1:IcSOAf4PyMp3U3XbIEj1/xJ2BjNN2jWv7JoyOsMxXUU=
 golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4 h1:ydJNl0ENAG67pFbB+9tfhiL2pYqLhfoaZFw/cjLhY4A=
@@ -693,7 +695,6 @@ golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvx
 golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3 h1:XQyxROzUlZH+WIQwySDgnISgOivlhjIEwaQaJEJrrN0=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
-golang.org/x/lint v0.0.0-20190409202823-959b441ac422 h1:QzoH/1pFpZguR8NrRHLcO6jKqfv2zpuSqZLgdm7ZmjI=
 golang.org/x/lint v0.0.0-20190409202823-959b441ac422/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/net v0.0.0-20180530234432-1e491301e022/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -717,10 +718,6 @@ golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20190424112056-4829fb13d2c6/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092 h1:4QSRKanuywn15aTZvI/mIDEgPQpswuFndXpOj3rKEco=
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
-golang.org/x/net v0.0.0-20190611141213-3f473d35a33a h1:+KkCgOMgnKSgenxTBoiwkMqTiouMIy/3o8RLdmSbGoY=
-golang.org/x/net v0.0.0-20190611141213-3f473d35a33a/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20190613194153-d28f0bde5980 h1:dfGZHvZk057jK2MCeWus/TowKpJ8y4AmooUzdBSR9GU=
-golang.org/x/net v0.0.0-20190613194153-d28f0bde5980/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20190619014844-b5b0513f8c1b h1:lkjdUzSyJ5P1+eal9fxXX9Xg2BTfswsonKUse48C0uE=
 golang.org/x/net v0.0.0-20190619014844-b5b0513f8c1b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859 h1:R/3boaszxrf1GEUWTVDzSKVwLmSJpwZ1yqXm8j0v2QI=
@@ -765,10 +762,6 @@ golang.org/x/sys v0.0.0-20190322080309-f49334f85ddc/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190429190828-d89cdac9e872/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190610200419-93c9922d18ae h1:xiXzMMEQdQcric9hXtr1QU98MHunKK7OTtsoU6bYWs4=
-golang.org/x/sys v0.0.0-20190610200419-93c9922d18ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190614160838-b47fdc937951 h1:ZUgGZ7PSkne6oY+VgAvayrB16owfm9/DKAtgWubzgzU=
-golang.org/x/sys v0.0.0-20190614160838-b47fdc937951/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190618155005-516e3c20635f h1:dHNZYIYdq2QuU6w73vZ/DzesPbVlZVYZTtTZmrnsbQ8=
 golang.org/x/sys v0.0.0-20190618155005-516e3c20635f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190626221950-04f50cda93cb h1:fgwFCsaw9buMuxNd6+DQfAuSFqbNiQZpcgJQAgJsK6k=