Do not assume all HTTP errors as Network errors (#7983)

In situations such as when client uploading data,
prematurely disconnects from server such as pressing
ctrl-c before uploading all the data. Under this
situation in distributed setup we prematurely
disconnect disks causing a reconnect loop. This has
an adverse affect we end up leaving a lot of files
in temporary location which ideally should have been
cleaned up when Put() prematurely fails.

This is also a regression which got introduced in #7610

cmd/object-api-common.go

@@ -129,7 +129,7 @@ func cleanupDir(ctx context.Context, storage StorageAPI, volume, dirPath string)
 
 		// Entry path is empty, just delete it.
 		if len(entries) == 0 {
-			err = storage.DeleteFile(volume, path.Clean(entryPath))
+			err = storage.DeleteFile(volume, entryPath)
 			logger.LogIf(ctx, err)
 			return err
 		}

cmd/storage-rest-client.go

@@ -44,8 +44,8 @@ func isNetworkError(err error) bool {
 	if err.Error() == errConnectionStale.Error() {
 		return true
 	}
-	if _, ok := err.(*rest.NetworkError); ok {
-		return true
+	if nerr, ok := err.(*rest.NetworkError); ok {
+		return isNetworkOrHostDown(nerr.Err)
 	}
 	return false
 }

cmd/utils.go

@@ -29,7 +29,6 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
-	"net/url"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -443,30 +442,21 @@ func isNetworkOrHostDown(err error) bool {
 	if err == nil {
 		return false
 	}
-	switch err.(type) {
-	case *net.DNSError, *net.OpError, net.UnknownNetworkError:
-		return true
-	case *url.Error:
-		// For a URL error, where it replies back "connection closed"
-		if strings.Contains(err.Error(), "Connection closed by foreign host") {
-			return true
-		}
-		return true
-	default:
-		if strings.Contains(err.Error(), "net/http: TLS handshake timeout") {
-			// If error is - tlsHandshakeTimeoutError,.
-			return true
-		} else if strings.Contains(err.Error(), "i/o timeout") {
-			// If error is - tcp timeoutError.
-			return true
-		} else if strings.Contains(err.Error(), "connection timed out") {
-			// If err is a net.Dial timeout.
-			return true
-		} else if strings.Contains(err.Error(), "net/http: HTTP/1.x transport connection broken") {
-			return true
-		}
+	// We need to figure if the error either a timeout
+	// or a non-temporary error.
+	e, ok := err.(net.Error)
+	if ok {
+		return e.Timeout()
 	}
-	return false
+	// Fallback to other mechanisms.
+	if strings.Contains(err.Error(), "i/o timeout") {
+		// If error is - tcp timeoutError.
+		ok = true
+	} else if strings.Contains(err.Error(), "connection timed out") {
+		// If err is a net.Dial timeout.
+		ok = true
+	}
+	return ok
 }
 
 // Used for registering with rest handlers (have a look at registerStorageRESTHandlers for usage example)