Merge pull request #792 from harshavardhana/pr_out_migrate_from_iodine_to_probe

Migrate from iodine to probe

commands.go

@@ -18,7 +18,6 @@ package main
 
 import (
 	"os"
-	"os/user"
 	"path/filepath"
 
 	"github.com/minio/cli"
@@ -163,22 +162,14 @@ func runServer(c *cli.Context) {
 	if c.Args().Present() {
 		cli.ShowCommandHelpAndExit(c, "server", 1)
 	}
-	_, err := user.Current()
-	if err != nil {
-		Fatalf("Unable to determine current user. Reason: %s\n", err)
-	}
 	apiServerConfig := getServerConfig(c)
-	err = server.StartServices(apiServerConfig)
+	err := server.StartServices(apiServerConfig)
 	if err != nil {
 		Fatalln(err)
 	}
 }
 
 func runController(c *cli.Context) {
-	_, err := user.Current()
-	if err != nil {
-		Fatalf("Unable to determine current user. Reason: %s\n", err)
-	}
 	if len(c.Args()) < 2 || c.Args().First() == "help" {
 		cli.ShowCommandHelpAndExit(c, "controller", 1) // last argument is exit code
 	}

disks.go

@@ -22,34 +22,34 @@ import (
 	"os"
 	"syscall"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // isUsable provides a comprehensive way of knowing if the provided mountPath is mounted and writable
-func isUsable(mountPath string) (bool, error) {
+func isUsable(mountPath string) (bool, *probe.Error) {
 	mntpoint, err := os.Stat(mountPath)
 	if err != nil {
-		return false, iodine.New(err, nil)
+		return false, probe.New(err)
 	}
 	parent, err := os.Stat("/")
 	if err != nil {
-		return false, iodine.New(err, nil)
+		return false, probe.New(err)
 	}
 	mntpointSt := mntpoint.Sys().(*syscall.Stat_t)
 	parentSt := parent.Sys().(*syscall.Stat_t)
 
 	if mntpointSt.Dev == parentSt.Dev {
-		return false, iodine.New(fmt.Errorf("Not mounted %s", mountPath), nil)
+		return false, probe.New(fmt.Errorf("Not mounted %s", mountPath))
 	}
 	testFile, err := ioutil.TempFile(mountPath, "writetest-")
 	if err != nil {
-		return false, iodine.New(err, nil)
+		return false, probe.New(err)
 	}
-	testFileName := testFile.Name()
 	// close the file, to avoid leaky fd's
-	testFile.Close()
+	defer testFile.Close()
+	testFileName := testFile.Name()
 	if err := os.Remove(testFileName); err != nil {
-		return false, iodine.New(err, nil)
+		return false, probe.New(err)
 	}
 	return true, nil
 }

main.go

@@ -22,11 +22,9 @@ import (
 	"os/user"
 	"runtime"
 	"strconv"
-	"time"
 
 	"github.com/dustin/go-humanize"
 	"github.com/minio/cli"
-	"github.com/minio/minio/pkg/iodine"
 )
 
 var globalDebugFlag = false
@@ -96,11 +94,13 @@ func getSystemData() map[string]string {
 	}
 }
 
-func main() {
-	// set up iodine
-	iodine.SetGlobalState("minio.version", Version)
-	iodine.SetGlobalState("minio.starttime", time.Now().Format(time.RFC3339))
+func init() {
+	if _, err := user.Current(); err != nil {
+		Fatalf("Unable to determine current user. Reason: %s\n", err)
+	}
+}
 
+func main() {
 	// set up go max processes
 	runtime.GOMAXPROCS(runtime.NumCPU())
 

pkg/auth/auth.go

@@ -19,6 +19,8 @@ package auth
 import (
 	"crypto/rand"
 	"encoding/base64"
+
+	"github.com/minio/minio/pkg/probe"
 )
 
 // Static alphaNumeric table used for generating unique keys
@@ -26,11 +28,11 @@ var alphaNumericTable = []byte("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ")
 
 // GenerateAccessKeyID - generate random alpha numeric value using only uppercase characters
 // takes input as size in integer
-func GenerateAccessKeyID() ([]byte, error) {
+func GenerateAccessKeyID() ([]byte, *probe.Error) {
 	alpha := make([]byte, MinioAccessID)
 	_, err := rand.Read(alpha)
 	if err != nil {
-		return nil, err
+		return nil, probe.New(err)
 	}
 	for i := 0; i < MinioAccessID; i++ {
 		alpha[i] = alphaNumericTable[alpha[i]%byte(len(alphaNumericTable))]
@@ -39,11 +41,11 @@ func GenerateAccessKeyID() ([]byte, error) {
 }
 
 // GenerateSecretAccessKey - generate random base64 numeric value from a random seed.
-func GenerateSecretAccessKey() ([]byte, error) {
+func GenerateSecretAccessKey() ([]byte, *probe.Error) {
 	rb := make([]byte, MinioSecretID)
 	_, err := rand.Read(rb)
 	if err != nil {
-		return nil, err
+		return nil, probe.New(err)
 	}
 	return []byte(base64.StdEncoding.EncodeToString(rb))[:MinioSecretID], nil
 }

pkg/auth/config.go

@@ -20,7 +20,7 @@ import (
 	"os/user"
 	"path/filepath"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/quick"
 )
 
@@ -38,13 +38,13 @@ type Config struct {
 }
 
 // getAuthConfigPath get donut config file path
-func getAuthConfigPath() (string, error) {
+func getAuthConfigPath() (string, *probe.Error) {
 	if customConfigPath != "" {
 		return customConfigPath, nil
 	}
 	u, err := user.Current()
 	if err != nil {
-		return "", iodine.New(err, nil)
+		return "", probe.New(err)
 	}
 	authConfigPath := filepath.Join(u.HomeDir, ".minio", "users.json")
 	return authConfigPath, nil
@@ -59,36 +59,36 @@ func SetAuthConfigPath(configPath string) {
 }
 
 // SaveConfig save donut config
-func SaveConfig(a *Config) error {
+func SaveConfig(a *Config) *probe.Error {
 	authConfigPath, err := getAuthConfigPath()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	qc, err := quick.New(a)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	if err := qc.Save(authConfigPath); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	return nil
 }
 
 // LoadConfig load donut config
-func LoadConfig() (*Config, error) {
+func LoadConfig() (*Config, *probe.Error) {
 	authConfigPath, err := getAuthConfigPath()
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	a := &Config{}
 	a.Version = "0.0.1"
 	a.Users = make(map[string]*User)
 	qc, err := quick.New(a)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	if err := qc.Load(authConfigPath); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	return qc.Data().(*Config), nil
 }

pkg/controller/client.go

@@ -22,7 +22,7 @@ import (
 
 	jsonrpc "github.com/gorilla/rpc/v2/json"
 	"github.com/minio/minio/pkg/auth"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/server/rpc"
 )
 
@@ -33,25 +33,31 @@ func closeResp(resp *http.Response) {
 }
 
 // GetMemStats get memory status of the server at given url
-func GetMemStats(url string) ([]byte, error) {
+func GetMemStats(url string) ([]byte, *probe.Error) {
 	op := RPCOps{
 		Method:  "MemStats.Get",
 		Request: rpc.Args{Request: ""},
 	}
 	req, err := NewRequest(url, op, http.DefaultTransport)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	resp, err := req.Do()
 	defer closeResp(resp)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	var reply rpc.MemStatsReply
 	if err := jsonrpc.DecodeClientResponse(resp.Body, &reply); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
+	}
+	{
+		jsonRespBytes, err := json.MarshalIndent(reply, "", "\t")
+		if err != nil {
+			return nil, probe.New(err)
+		}
+		return jsonRespBytes, nil
 	}
-	return json.MarshalIndent(reply, "", "\t")
 }
 
 // GetSysInfo get system status of the server at given url
@@ -62,18 +68,24 @@ func GetSysInfo(url string) ([]byte, error) {
 	}
 	req, err := NewRequest(url, op, http.DefaultTransport)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	resp, err := req.Do()
 	defer closeResp(resp)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	var reply rpc.SysInfoReply
 	if err := jsonrpc.DecodeClientResponse(resp.Body, &reply); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
+	}
+	{
+		jsonRespBytes, err := json.MarshalIndent(reply, "", "\t")
+		if err != nil {
+			return nil, probe.New(err)
+		}
+		return jsonRespBytes, nil
 	}
-	return json.MarshalIndent(reply, "", "\t")
 }
 
 // GetAuthKeys get access key id and secret access key
@@ -84,16 +96,16 @@ func GetAuthKeys(url string) ([]byte, error) {
 	}
 	req, err := NewRequest(url, op, http.DefaultTransport)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	resp, err := req.Do()
 	defer closeResp(resp)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	var reply rpc.AuthReply
 	if err := jsonrpc.DecodeClientResponse(resp.Body, &reply); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	authConfig := &auth.Config{}
 	authConfig.Version = "0.0.1"
@@ -104,9 +116,15 @@ func GetAuthKeys(url string) ([]byte, error) {
 	user.SecretAccessKey = reply.SecretAccessKey
 	authConfig.Users[reply.AccessKeyID] = user
 	if err := auth.SaveConfig(authConfig); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
+	}
+	{
+		jsonRespBytes, err := json.MarshalIndent(reply, "", "\t")
+		if err != nil {
+			return nil, probe.New(err)
+		}
+		return jsonRespBytes, nil
 	}
-	return json.MarshalIndent(reply, "", "\t")
 }
 
 // Add more functions here for other RPC messages

pkg/controller/rpc.go

@@ -21,7 +21,7 @@ import (
 	"net/http"
 
 	"github.com/gorilla/rpc/v2/json"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // RPCOps RPC operation
@@ -37,14 +37,14 @@ type RPCRequest struct {
 }
 
 // NewRequest initiate a new client RPC request
-func NewRequest(url string, op RPCOps, transport http.RoundTripper) (*RPCRequest, error) {
+func NewRequest(url string, op RPCOps, transport http.RoundTripper) (*RPCRequest, *probe.Error) {
 	params, err := json.EncodeClientRequest(op.Method, op.Request)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	req, err := http.NewRequest("POST", url, bytes.NewReader(params))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	rpcReq := &RPCRequest{}
 	rpcReq.req = req
@@ -57,10 +57,10 @@ func NewRequest(url string, op RPCOps, transport http.RoundTripper) (*RPCRequest
 }
 
 // Do - make a http connection
-func (r RPCRequest) Do() (*http.Response, error) {
+func (r RPCRequest) Do() (*http.Response, *probe.Error) {
 	resp, err := r.transport.RoundTrip(r.req)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	return resp, nil
 }

pkg/donut/bucket.go

@@ -34,7 +34,7 @@ import (
 	"github.com/minio/minio/pkg/crypto/sha256"
 	"github.com/minio/minio/pkg/crypto/sha512"
 	"github.com/minio/minio/pkg/donut/disk"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 const (
@@ -52,15 +52,9 @@ type bucket struct {
 }
 
 // newBucket - instantiate a new bucket
-func newBucket(bucketName, aclType, donutName string, nodes map[string]node) (bucket, BucketMetadata, error) {
-	errParams := map[string]string{
-		"bucketName": bucketName,
-		"donutName":  donutName,
-		"aclType":    aclType,
-	}
-
+func newBucket(bucketName, aclType, donutName string, nodes map[string]node) (bucket, BucketMetadata, *probe.Error) {
 	if strings.TrimSpace(bucketName) == "" || strings.TrimSpace(donutName) == "" {
-		return bucket{}, BucketMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return bucket{}, BucketMetadata{}, probe.New(InvalidArgument{})
 	}
 
 	b := bucket{}
@@ -89,14 +83,14 @@ func (b bucket) getBucketName() string {
 }
 
 // getBucketMetadataReaders -
-func (b bucket) getBucketMetadataReaders() (map[int]io.ReadCloser, error) {
+func (b bucket) getBucketMetadataReaders() (map[int]io.ReadCloser, *probe.Error) {
 	readers := make(map[int]io.ReadCloser)
 	var disks map[int]disk.Disk
-	var err error
+	var err *probe.Error
 	for _, node := range b.nodes {
 		disks, err = node.ListDisks()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 	}
 	var bucketMetaDataReader io.ReadCloser
@@ -108,40 +102,44 @@ func (b bucket) getBucketMetadataReaders() (map[int]io.ReadCloser, error) {
 		readers[order] = bucketMetaDataReader
 	}
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	return readers, nil
 }
 
 // getBucketMetadata -
-func (b bucket) getBucketMetadata() (*AllBuckets, error) {
-	var err error
+func (b bucket) getBucketMetadata() (*AllBuckets, *probe.Error) {
 	metadata := new(AllBuckets)
-	readers, err := b.getBucketMetadataReaders()
-	if err != nil {
-		return nil, iodine.New(err, nil)
+	var readers map[int]io.ReadCloser
+	{
+		var err *probe.Error
+		readers, err = b.getBucketMetadataReaders()
+		if err != nil {
+			return nil, err.Trace()
+		}
 	}
 	for _, reader := range readers {
 		defer reader.Close()
 	}
+	var err error
 	for _, reader := range readers {
 		jenc := json.NewDecoder(reader)
 		if err = jenc.Decode(metadata); err == nil {
 			return metadata, nil
 		}
 	}
-	return nil, iodine.New(err, nil)
+	return nil, probe.New(err)
 }
 
 // GetObjectMetadata - get metadata for an object
-func (b bucket) GetObjectMetadata(objectName string) (ObjectMetadata, error) {
+func (b bucket) GetObjectMetadata(objectName string) (ObjectMetadata, *probe.Error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 	return b.readObjectMetadata(objectName)
 }
 
 // ListObjects - list all objects
-func (b bucket) ListObjects(prefix, marker, delimiter string, maxkeys int) (ListObjectsResults, error) {
+func (b bucket) ListObjects(prefix, marker, delimiter string, maxkeys int) (ListObjectsResults, *probe.Error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 	if maxkeys <= 0 {
@@ -151,7 +149,7 @@ func (b bucket) ListObjects(prefix, marker, delimiter string, maxkeys int) (List
 	var objects []string
 	bucketMetadata, err := b.getBucketMetadata()
 	if err != nil {
-		return ListObjectsResults{}, iodine.New(err, nil)
+		return ListObjectsResults{}, err.Trace()
 	}
 	for objectName := range bucketMetadata.Buckets[b.getBucketName()].Multiparts {
 		if strings.HasPrefix(objectName, strings.TrimSpace(prefix)) {
@@ -206,7 +204,7 @@ func (b bucket) ListObjects(prefix, marker, delimiter string, maxkeys int) (List
 	for _, objectName := range results {
 		objMetadata, err := b.readObjectMetadata(normalizeObjectName(objectName))
 		if err != nil {
-			return ListObjectsResults{}, iodine.New(err, nil)
+			return ListObjectsResults{}, err.Trace()
 		}
 		listObjects.Objects[objectName] = objMetadata
 	}
@@ -214,22 +212,22 @@ func (b bucket) ListObjects(prefix, marker, delimiter string, maxkeys int) (List
 }
 
 // ReadObject - open an object to read
-func (b bucket) ReadObject(objectName string) (reader io.ReadCloser, size int64, err error) {
+func (b bucket) ReadObject(objectName string) (reader io.ReadCloser, size int64, err *probe.Error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 	reader, writer := io.Pipe()
 	// get list of objects
 	bucketMetadata, err := b.getBucketMetadata()
 	if err != nil {
-		return nil, 0, iodine.New(err, nil)
+		return nil, 0, err.Trace()
 	}
 	// check if object exists
 	if _, ok := bucketMetadata.Buckets[b.getBucketName()].BucketObjects[objectName]; !ok {
-		return nil, 0, iodine.New(ObjectNotFound{Object: objectName}, nil)
+		return nil, 0, probe.New(ObjectNotFound{Object: objectName})
 	}
 	objMetadata, err := b.readObjectMetadata(normalizeObjectName(objectName))
 	if err != nil {
-		return nil, 0, iodine.New(err, nil)
+		return nil, 0, err.Trace()
 	}
 	// read and reply back to GetObject() request in a go-routine
 	go b.readObjectData(normalizeObjectName(objectName), writer, objMetadata)
@@ -237,15 +235,15 @@ func (b bucket) ReadObject(objectName string) (reader io.ReadCloser, size int64,
 }
 
 // WriteObject - write a new object into bucket
-func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64, expectedMD5Sum string, metadata map[string]string, signature *Signature) (ObjectMetadata, error) {
+func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64, expectedMD5Sum string, metadata map[string]string, signature *Signature) (ObjectMetadata, *probe.Error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 	if objectName == "" || objectData == nil {
-		return ObjectMetadata{}, iodine.New(InvalidArgument{}, nil)
+		return ObjectMetadata{}, probe.New(InvalidArgument{})
 	}
 	writers, err := b.getObjectWriters(normalizeObjectName(objectName), "data")
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, nil)
+		return ObjectMetadata{}, err.Trace()
 	}
 	sumMD5 := md5.New()
 	sum512 := sha512.New()
@@ -268,7 +266,7 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64,
 		totalLength, err := io.Copy(mw, objectData)
 		if err != nil {
 			CleanupWritersOnError(writers)
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, probe.New(err)
 		}
 		objMetadata.Size = totalLength
 	case false:
@@ -276,13 +274,13 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64,
 		k, m, err := b.getDataAndParity(len(writers))
 		if err != nil {
 			CleanupWritersOnError(writers)
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		// write encoded data with k, m and writers
 		chunkCount, totalLength, err := b.writeObjectData(k, m, writers, objectData, size, mwriter)
 		if err != nil {
 			CleanupWritersOnError(writers)
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		/// donutMetadata section
 		objMetadata.BlockSize = blockSize
@@ -301,14 +299,14 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64,
 		if err != nil {
 			// error occurred while doing signature calculation, we return and also cleanup any temporary writers.
 			CleanupWritersOnError(writers)
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		if !ok {
 			// purge all writers, when control flow reaches here
 			//
 			// Signature mismatch occurred all temp files to be removed and all data purged.
 			CleanupWritersOnError(writers)
-			return ObjectMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return ObjectMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 	objMetadata.MD5Sum = hex.EncodeToString(dataMD5sum)
@@ -317,7 +315,7 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64,
 	// Verify if the written object is equal to what is expected, only if it is requested as such
 	if strings.TrimSpace(expectedMD5Sum) != "" {
 		if err := b.isMD5SumEqual(strings.TrimSpace(expectedMD5Sum), objMetadata.MD5Sum); err != nil {
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 	}
 	objMetadata.Metadata = metadata
@@ -325,7 +323,7 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64,
 	if err := b.writeObjectMetadata(normalizeObjectName(objectName), objMetadata); err != nil {
 		// purge all writers, when control flow reaches here
 		CleanupWritersOnError(writers)
-		return ObjectMetadata{}, iodine.New(err, nil)
+		return ObjectMetadata{}, err.Trace()
 	}
 	// close all writers, when control flow reaches here
 	for _, writer := range writers {
@@ -335,39 +333,39 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, size int64,
 }
 
 // isMD5SumEqual - returns error if md5sum mismatches, other its `nil`
-func (b bucket) isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) error {
+func (b bucket) isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) *probe.Error {
 	if strings.TrimSpace(expectedMD5Sum) != "" && strings.TrimSpace(actualMD5Sum) != "" {
 		expectedMD5SumBytes, err := hex.DecodeString(expectedMD5Sum)
 		if err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 		actualMD5SumBytes, err := hex.DecodeString(actualMD5Sum)
 		if err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 		if !bytes.Equal(expectedMD5SumBytes, actualMD5SumBytes) {
-			return iodine.New(BadDigest{}, nil)
+			return probe.New(BadDigest{})
 		}
 		return nil
 	}
-	return iodine.New(InvalidArgument{}, nil)
+	return probe.New(InvalidArgument{})
 }
 
 // writeObjectMetadata - write additional object metadata
-func (b bucket) writeObjectMetadata(objectName string, objMetadata ObjectMetadata) error {
+func (b bucket) writeObjectMetadata(objectName string, objMetadata ObjectMetadata) *probe.Error {
 	if objMetadata.Object == "" {
-		return iodine.New(InvalidArgument{}, nil)
+		return probe.New(InvalidArgument{})
 	}
 	objMetadataWriters, err := b.getObjectWriters(objectName, objectMetadataConfig)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	for _, objMetadataWriter := range objMetadataWriters {
 		jenc := json.NewEncoder(objMetadataWriter)
 		if err := jenc.Encode(&objMetadata); err != nil {
 			// Close writers and purge all temporary entries
 			CleanupWritersOnError(objMetadataWriters)
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 	}
 	for _, objMetadataWriter := range objMetadataWriters {
@@ -377,26 +375,28 @@ func (b bucket) writeObjectMetadata(objectName string, objMetadata ObjectMetadat
 }
 
 // readObjectMetadata - read object metadata
-func (b bucket) readObjectMetadata(objectName string) (ObjectMetadata, error) {
+func (b bucket) readObjectMetadata(objectName string) (ObjectMetadata, *probe.Error) {
 	if objectName == "" {
-		return ObjectMetadata{}, iodine.New(InvalidArgument{}, nil)
+		return ObjectMetadata{}, probe.New(InvalidArgument{})
 	}
-	var err error
 	objMetadata := ObjectMetadata{}
 	objMetadataReaders, err := b.getObjectReaders(objectName, objectMetadataConfig)
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, nil)
+		return ObjectMetadata{}, err.Trace()
 	}
 	for _, objMetadataReader := range objMetadataReaders {
 		defer objMetadataReader.Close()
 	}
-	for _, objMetadataReader := range objMetadataReaders {
-		jdec := json.NewDecoder(objMetadataReader)
-		if err = jdec.Decode(&objMetadata); err == nil {
-			return objMetadata, nil
+	{
+		var err error
+		for _, objMetadataReader := range objMetadataReaders {
+			jdec := json.NewDecoder(objMetadataReader)
+			if err = jdec.Decode(&objMetadata); err == nil {
+				return objMetadata, nil
+			}
 		}
+		return ObjectMetadata{}, probe.New(err)
 	}
-	return ObjectMetadata{}, iodine.New(err, nil)
 }
 
 // TODO - This a temporary normalization of objectNames, need to find a better way
@@ -413,14 +413,14 @@ func normalizeObjectName(objectName string) string {
 }
 
 // getDataAndParity - calculate k, m (data and parity) values from number of disks
-func (b bucket) getDataAndParity(totalWriters int) (k uint8, m uint8, err error) {
+func (b bucket) getDataAndParity(totalWriters int) (k uint8, m uint8, err *probe.Error) {
 	if totalWriters <= 1 {
-		return 0, 0, iodine.New(InvalidArgument{}, nil)
+		return 0, 0, probe.New(InvalidArgument{})
 	}
 	quotient := totalWriters / 2 // not using float or abs to let integer round off to lower value
 	// quotient cannot be bigger than (255 / 2) = 127
 	if quotient > 127 {
-		return 0, 0, iodine.New(ParityOverflow{}, nil)
+		return 0, 0, probe.New(ParityOverflow{})
 	}
 	remainder := totalWriters % 2 // will be 1 for odd and 0 for even numbers
 	k = uint8(quotient + remainder)
@@ -429,11 +429,11 @@ func (b bucket) getDataAndParity(totalWriters int) (k uint8, m uint8, err error)
 }
 
 // writeObjectData -
-func (b bucket) writeObjectData(k, m uint8, writers []io.WriteCloser, objectData io.Reader, size int64, writer io.Writer) (int, int, error) {
+func (b bucket) writeObjectData(k, m uint8, writers []io.WriteCloser, objectData io.Reader, size int64, writer io.Writer) (int, int, *probe.Error) {
 	encoder, err := newEncoder(k, m, "Cauchy")
 	chunkSize := int64(10 * 1024 * 1024)
 	if err != nil {
-		return 0, 0, iodine.New(err, nil)
+		return 0, 0, err.Trace()
 	}
 	chunkCount := 0
 	totalLength := 0
@@ -447,11 +447,10 @@ func (b bucket) writeObjectData(k, m uint8, writers []io.WriteCloser, objectData
 		totalLength = totalLength + int(readSize)
 		encodedBlocks, inputData, err := encoder.EncodeStream(objectData, readSize)
 		if err != nil {
-			return 0, 0, iodine.New(err, nil)
+			return 0, 0, err.Trace()
 		}
-		_, err = writer.Write(inputData)
-		if err != nil {
-			return 0, 0, iodine.New(err, nil)
+		if _, err := writer.Write(inputData); err != nil {
+			return 0, 0, probe.New(err)
 		}
 		for blockIndex, block := range encodedBlocks {
 			errCh := make(chan error, 1)
@@ -462,7 +461,7 @@ func (b bucket) writeObjectData(k, m uint8, writers []io.WriteCloser, objectData
 			}(writers[blockIndex], bytes.NewReader(block), errCh)
 			if err := <-errCh; err != nil {
 				// Returning error is fine here CleanupErrors() would cleanup writers
-				return 0, 0, iodine.New(err, nil)
+				return 0, 0, probe.New(err)
 			}
 		}
 		chunkCount = chunkCount + 1
@@ -474,21 +473,25 @@ func (b bucket) writeObjectData(k, m uint8, writers []io.WriteCloser, objectData
 func (b bucket) readObjectData(objectName string, writer *io.PipeWriter, objMetadata ObjectMetadata) {
 	readers, err := b.getObjectReaders(objectName, "data")
 	if err != nil {
-		writer.CloseWithError(iodine.New(err, nil))
+		writer.CloseWithError(err.Trace())
 		return
 	}
 	for _, reader := range readers {
 		defer reader.Close()
 	}
-	expectedMd5sum, err := hex.DecodeString(objMetadata.MD5Sum)
-	if err != nil {
-		writer.CloseWithError(iodine.New(err, nil))
-		return
-	}
-	expected512Sum, err := hex.DecodeString(objMetadata.SHA512Sum)
-	if err != nil {
-		writer.CloseWithError(iodine.New(err, nil))
-		return
+	var expected512Sum, expectedMd5sum []byte
+	{
+		var err error
+		expectedMd5sum, err = hex.DecodeString(objMetadata.MD5Sum)
+		if err != nil {
+			writer.CloseWithError(probe.New(err))
+			return
+		}
+		expected512Sum, err = hex.DecodeString(objMetadata.SHA512Sum)
+		if err != nil {
+			writer.CloseWithError(probe.New(err))
+			return
+		}
 	}
 	hasher := md5.New()
 	sum512hasher := sha256.New()
@@ -496,24 +499,23 @@ func (b bucket) readObjectData(objectName string, writer *io.PipeWriter, objMeta
 	switch len(readers) > 1 {
 	case true:
 		if objMetadata.ErasureTechnique == "" {
-			writer.CloseWithError(iodine.New(MissingErasureTechnique{}, nil))
+			writer.CloseWithError(probe.New(MissingErasureTechnique{}))
 			return
 		}
 		encoder, err := newEncoder(objMetadata.DataDisks, objMetadata.ParityDisks, objMetadata.ErasureTechnique)
 		if err != nil {
-			writer.CloseWithError(iodine.New(err, nil))
+			writer.CloseWithError(err.Trace())
 			return
 		}
 		totalLeft := objMetadata.Size
 		for i := 0; i < objMetadata.ChunkCount; i++ {
 			decodedData, err := b.decodeEncodedData(totalLeft, int64(objMetadata.BlockSize), readers, encoder, writer)
 			if err != nil {
-				writer.CloseWithError(iodine.New(err, nil))
+				writer.CloseWithError(err.Trace())
 				return
 			}
-			_, err = io.Copy(mwriter, bytes.NewReader(decodedData))
-			if err != nil {
-				writer.CloseWithError(iodine.New(err, nil))
+			if _, err := io.Copy(mwriter, bytes.NewReader(decodedData)); err != nil {
+				writer.CloseWithError(probe.New(err))
 				return
 			}
 			totalLeft = totalLeft - int64(objMetadata.BlockSize)
@@ -521,17 +523,17 @@ func (b bucket) readObjectData(objectName string, writer *io.PipeWriter, objMeta
 	case false:
 		_, err := io.Copy(writer, readers[0])
 		if err != nil {
-			writer.CloseWithError(iodine.New(err, nil))
+			writer.CloseWithError(probe.New(err))
 			return
 		}
 	}
 	// check if decodedData md5sum matches
 	if !bytes.Equal(expectedMd5sum, hasher.Sum(nil)) {
-		writer.CloseWithError(iodine.New(ChecksumMismatch{}, nil))
+		writer.CloseWithError(probe.New(ChecksumMismatch{}))
 		return
 	}
 	if !bytes.Equal(expected512Sum, sum512hasher.Sum(nil)) {
-		writer.CloseWithError(iodine.New(ChecksumMismatch{}, nil))
+		writer.CloseWithError(probe.New(ChecksumMismatch{}))
 		return
 	}
 	writer.Close()
@@ -539,7 +541,7 @@ func (b bucket) readObjectData(objectName string, writer *io.PipeWriter, objMeta
 }
 
 // decodeEncodedData -
-func (b bucket) decodeEncodedData(totalLeft, blockSize int64, readers map[int]io.ReadCloser, encoder encoder, writer *io.PipeWriter) ([]byte, error) {
+func (b bucket) decodeEncodedData(totalLeft, blockSize int64, readers map[int]io.ReadCloser, encoder encoder, writer *io.PipeWriter) ([]byte, *probe.Error) {
 	var curBlockSize int64
 	if blockSize < totalLeft {
 		curBlockSize = blockSize
@@ -548,34 +550,34 @@ func (b bucket) decodeEncodedData(totalLeft, blockSize int64, readers map[int]io
 	}
 	curChunkSize, err := encoder.GetEncodedBlockLen(int(curBlockSize))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	encodedBytes := make([][]byte, encoder.k+encoder.m)
 	for i, reader := range readers {
 		var bytesBuffer bytes.Buffer
 		_, err := io.CopyN(&bytesBuffer, reader, int64(curChunkSize))
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 		encodedBytes[i] = bytesBuffer.Bytes()
 	}
 	decodedData, err := encoder.Decode(encodedBytes, int(curBlockSize))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	return decodedData, nil
 }
 
 // getObjectReaders -
-func (b bucket) getObjectReaders(objectName, objectMeta string) (map[int]io.ReadCloser, error) {
+func (b bucket) getObjectReaders(objectName, objectMeta string) (map[int]io.ReadCloser, *probe.Error) {
 	readers := make(map[int]io.ReadCloser)
 	var disks map[int]disk.Disk
-	var err error
+	var err *probe.Error
 	nodeSlice := 0
 	for _, node := range b.nodes {
 		disks, err = node.ListDisks()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 		for order, disk := range disks {
 			var objectSlice io.ReadCloser
@@ -589,19 +591,19 @@ func (b bucket) getObjectReaders(objectName, objectMeta string) (map[int]io.Read
 		nodeSlice = nodeSlice + 1
 	}
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	return readers, nil
 }
 
 // getObjectWriters -
-func (b bucket) getObjectWriters(objectName, objectMeta string) ([]io.WriteCloser, error) {
+func (b bucket) getObjectWriters(objectName, objectMeta string) ([]io.WriteCloser, *probe.Error) {
 	var writers []io.WriteCloser
 	nodeSlice := 0
 	for _, node := range b.nodes {
 		disks, err := node.ListDisks()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 		writers = make([]io.WriteCloser, len(disks))
 		for order, disk := range disks {
@@ -609,7 +611,7 @@ func (b bucket) getObjectWriters(objectName, objectMeta string) ([]io.WriteClose
 			objectPath := filepath.Join(b.donutName, bucketSlice, objectName, objectMeta)
 			objectSlice, err := disk.CreateFile(objectPath)
 			if err != nil {
-				return nil, iodine.New(err, nil)
+				return nil, err.Trace()
 			}
 			writers[order] = objectSlice
 		}

pkg/donut/config.go

@@ -20,18 +20,18 @@ import (
 	"os/user"
 	"path/filepath"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/quick"
 )
 
 // getDonutConfigPath get donut config file path
-func getDonutConfigPath() (string, error) {
+func getDonutConfigPath() (string, *probe.Error) {
 	if customConfigPath != "" {
 		return customConfigPath, nil
 	}
 	u, err := user.Current()
 	if err != nil {
-		return "", iodine.New(err, nil)
+		return "", probe.New(err)
 	}
 	donutConfigPath := filepath.Join(u.HomeDir, ".minio", "donut.json")
 	return donutConfigPath, nil
@@ -46,35 +46,35 @@ func SetDonutConfigPath(configPath string) {
 }
 
 // SaveConfig save donut config
-func SaveConfig(a *Config) error {
+func SaveConfig(a *Config) *probe.Error {
 	donutConfigPath, err := getDonutConfigPath()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	qc, err := quick.New(a)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	if err := qc.Save(donutConfigPath); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	return nil
 }
 
 // LoadConfig load donut config
-func LoadConfig() (*Config, error) {
+func LoadConfig() (*Config, *probe.Error) {
 	donutConfigPath, err := getDonutConfigPath()
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	a := &Config{}
 	a.Version = "0.0.1"
 	qc, err := quick.New(a)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	if err := qc.Load(donutConfigPath); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	return qc.Data().(*Config), nil
 }

pkg/donut/disk/disk.go

@@ -25,7 +25,7 @@ import (
 	"sync"
 	"syscall"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/utils/atomic"
 )
 
@@ -37,21 +37,22 @@ type Disk struct {
 }
 
 // New - instantiate new disk
-func New(diskPath string) (Disk, error) {
+func New(diskPath string) (Disk, *probe.Error) {
 	if diskPath == "" {
-		return Disk{}, iodine.New(InvalidArgument{}, nil)
+		return Disk{}, probe.New(InvalidArgument{})
 	}
 	st, err := os.Stat(diskPath)
 	if err != nil {
-		return Disk{}, iodine.New(err, nil)
+		return Disk{}, probe.New(err)
 	}
+
 	if !st.IsDir() {
-		return Disk{}, iodine.New(syscall.ENOTDIR, nil)
+		return Disk{}, probe.New(syscall.ENOTDIR)
 	}
 	s := syscall.Statfs_t{}
 	err = syscall.Statfs(diskPath, &s)
 	if err != nil {
-		return Disk{}, iodine.New(err, nil)
+		return Disk{}, probe.New(err)
 	}
 	disk := Disk{
 		lock:   &sync.Mutex{},
@@ -63,8 +64,7 @@ func New(diskPath string) (Disk, error) {
 		disk.fsInfo["MountPoint"] = disk.path
 		return disk, nil
 	}
-	return Disk{}, iodine.New(UnsupportedFilesystem{Type: strconv.FormatInt(int64(s.Type), 10)},
-		map[string]string{"Type": strconv.FormatInt(int64(s.Type), 10)})
+	return Disk{}, probe.New(UnsupportedFilesystem{Type: strconv.FormatInt(int64(s.Type), 10)})
 }
 
 // IsUsable - is disk usable, alive
@@ -99,25 +99,28 @@ func (disk Disk) GetFSInfo() map[string]string {
 }
 
 // MakeDir - make a directory inside disk root path
-func (disk Disk) MakeDir(dirname string) error {
+func (disk Disk) MakeDir(dirname string) *probe.Error {
 	disk.lock.Lock()
 	defer disk.lock.Unlock()
-	return os.MkdirAll(filepath.Join(disk.path, dirname), 0700)
+	if err := os.MkdirAll(filepath.Join(disk.path, dirname), 0700); err != nil {
+		return probe.New(err)
+	}
+	return nil
 }
 
 // ListDir - list a directory inside disk root path, get only directories
-func (disk Disk) ListDir(dirname string) ([]os.FileInfo, error) {
+func (disk Disk) ListDir(dirname string) ([]os.FileInfo, *probe.Error) {
 	disk.lock.Lock()
 	defer disk.lock.Unlock()
 
 	dir, err := os.Open(filepath.Join(disk.path, dirname))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	defer dir.Close()
 	contents, err := dir.Readdir(-1)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	var directories []os.FileInfo
 	for _, content := range contents {
@@ -130,18 +133,18 @@ func (disk Disk) ListDir(dirname string) ([]os.FileInfo, error) {
 }
 
 // ListFiles - list a directory inside disk root path, get only files
-func (disk Disk) ListFiles(dirname string) ([]os.FileInfo, error) {
+func (disk Disk) ListFiles(dirname string) ([]os.FileInfo, *probe.Error) {
 	disk.lock.Lock()
 	defer disk.lock.Unlock()
 
 	dir, err := os.Open(filepath.Join(disk.path, dirname))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	defer dir.Close()
 	contents, err := dir.Readdir(-1)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	var files []os.FileInfo
 	for _, content := range contents {
@@ -154,48 +157,48 @@ func (disk Disk) ListFiles(dirname string) ([]os.FileInfo, error) {
 }
 
 // CreateFile - create a file inside disk root path, replies with custome disk.File which provides atomic writes
-func (disk Disk) CreateFile(filename string) (*atomic.File, error) {
+func (disk Disk) CreateFile(filename string) (*atomic.File, *probe.Error) {
 	disk.lock.Lock()
 	defer disk.lock.Unlock()
 
 	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
+		return nil, probe.New(InvalidArgument{})
 	}
 
 	f, err := atomic.FileCreate(filepath.Join(disk.path, filename))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 
 	return f, nil
 }
 
 // Open - read a file inside disk root path
-func (disk Disk) Open(filename string) (*os.File, error) {
+func (disk Disk) Open(filename string) (*os.File, *probe.Error) {
 	disk.lock.Lock()
 	defer disk.lock.Unlock()
 
 	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
+		return nil, probe.New(InvalidArgument{})
 	}
 	dataFile, err := os.Open(filepath.Join(disk.path, filename))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	return dataFile, nil
 }
 
 // OpenFile - Use with caution
-func (disk Disk) OpenFile(filename string, flags int, perm os.FileMode) (*os.File, error) {
+func (disk Disk) OpenFile(filename string, flags int, perm os.FileMode) (*os.File, *probe.Error) {
 	disk.lock.Lock()
 	defer disk.lock.Unlock()
 
 	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
+		return nil, probe.New(InvalidArgument{})
 	}
 	dataFile, err := os.OpenFile(filepath.Join(disk.path, filename), flags, perm)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	return dataFile, nil
 }

pkg/donut/donut-v1.go

@@ -35,7 +35,7 @@ import (
 	"github.com/minio/minio/pkg/crypto/sha256"
 	"github.com/minio/minio/pkg/crypto/sha512"
 	"github.com/minio/minio/pkg/donut/disk"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // config files used inside Donut
@@ -52,41 +52,41 @@ const (
 /// v1 API functions
 
 // makeBucket - make a new bucket
-func (donut API) makeBucket(bucket string, acl BucketACL) error {
+func (donut API) makeBucket(bucket string, acl BucketACL) *probe.Error {
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return iodine.New(InvalidArgument{}, nil)
+		return probe.New(InvalidArgument{})
 	}
 	return donut.makeDonutBucket(bucket, acl.String())
 }
 
 // getBucketMetadata - get bucket metadata
-func (donut API) getBucketMetadata(bucketName string) (BucketMetadata, error) {
+func (donut API) getBucketMetadata(bucketName string) (BucketMetadata, *probe.Error) {
 	if err := donut.listDonutBuckets(); err != nil {
-		return BucketMetadata{}, iodine.New(err, nil)
+		return BucketMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucketName]; !ok {
-		return BucketMetadata{}, iodine.New(BucketNotFound{Bucket: bucketName}, nil)
+		return BucketMetadata{}, probe.New(BucketNotFound{Bucket: bucketName})
 	}
 	metadata, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return BucketMetadata{}, iodine.New(err, nil)
+		return BucketMetadata{}, err.Trace()
 	}
 	return metadata.Buckets[bucketName], nil
 }
 
 // setBucketMetadata - set bucket metadata
-func (donut API) setBucketMetadata(bucketName string, bucketMetadata map[string]string) error {
+func (donut API) setBucketMetadata(bucketName string, bucketMetadata map[string]string) *probe.Error {
 	if err := donut.listDonutBuckets(); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	metadata, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	oldBucketMetadata := metadata.Buckets[bucketName]
 	acl, ok := bucketMetadata["acl"]
 	if !ok {
-		return iodine.New(InvalidArgument{}, nil)
+		return probe.New(InvalidArgument{})
 	}
 	oldBucketMetadata.ACL = BucketACL(acl)
 	metadata.Buckets[bucketName] = oldBucketMetadata
@@ -94,9 +94,9 @@ func (donut API) setBucketMetadata(bucketName string, bucketMetadata map[string]
 }
 
 // listBuckets - return list of buckets
-func (donut API) listBuckets() (map[string]BucketMetadata, error) {
+func (donut API) listBuckets() (map[string]BucketMetadata, *probe.Error) {
 	if err := donut.listDonutBuckets(); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	metadata, err := donut.getDonutBucketMetadata()
 	if err != nil {
@@ -112,95 +112,80 @@ func (donut API) listBuckets() (map[string]BucketMetadata, error) {
 }
 
 // listObjects - return list of objects
-func (donut API) listObjects(bucket, prefix, marker, delimiter string, maxkeys int) (ListObjectsResults, error) {
-	errParams := map[string]string{
-		"bucket":    bucket,
-		"prefix":    prefix,
-		"marker":    marker,
-		"delimiter": delimiter,
-		"maxkeys":   strconv.Itoa(maxkeys),
-	}
+func (donut API) listObjects(bucket, prefix, marker, delimiter string, maxkeys int) (ListObjectsResults, *probe.Error) {
 	if err := donut.listDonutBuckets(); err != nil {
-		return ListObjectsResults{}, iodine.New(err, errParams)
+		return ListObjectsResults{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return ListObjectsResults{}, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return ListObjectsResults{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	listObjects, err := donut.buckets[bucket].ListObjects(prefix, marker, delimiter, maxkeys)
 	if err != nil {
-		return ListObjectsResults{}, iodine.New(err, errParams)
+		return ListObjectsResults{}, err.Trace()
 	}
 	return listObjects, nil
 }
 
 // putObject - put object
-func (donut API) putObject(bucket, object, expectedMD5Sum string, reader io.Reader, size int64, metadata map[string]string, signature *Signature) (ObjectMetadata, error) {
-	errParams := map[string]string{
-		"bucket": bucket,
-		"object": object,
-	}
+func (donut API) putObject(bucket, object, expectedMD5Sum string, reader io.Reader, size int64, metadata map[string]string, signature *Signature) (ObjectMetadata, *probe.Error) {
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return ObjectMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidArgument{})
 	}
 	if object == "" || strings.TrimSpace(object) == "" {
-		return ObjectMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidArgument{})
 	}
 	if err := donut.listDonutBuckets(); err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	bucketMeta, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	if _, ok := bucketMeta.Buckets[bucket].BucketObjects[object]; ok {
-		return ObjectMetadata{}, iodine.New(ObjectExists{Object: object}, errParams)
+		return ObjectMetadata{}, probe.New(ObjectExists{Object: object})
 	}
 	objMetadata, err := donut.buckets[bucket].WriteObject(object, reader, size, expectedMD5Sum, metadata, signature)
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	bucketMeta.Buckets[bucket].BucketObjects[object] = struct{}{}
 	if err := donut.setDonutBucketMetadata(bucketMeta); err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	return objMetadata, nil
 }
 
 // putObject - put object
-func (donut API) putObjectPart(bucket, object, expectedMD5Sum, uploadID string, partID int, reader io.Reader, size int64, metadata map[string]string, signature *Signature) (PartMetadata, error) {
-	errParams := map[string]string{
-		"bucket": bucket,
-		"object": object,
-	}
+func (donut API) putObjectPart(bucket, object, expectedMD5Sum, uploadID string, partID int, reader io.Reader, size int64, metadata map[string]string, signature *Signature) (PartMetadata, *probe.Error) {
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return PartMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return PartMetadata{}, probe.New(InvalidArgument{})
 	}
 	if object == "" || strings.TrimSpace(object) == "" {
-		return PartMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return PartMetadata{}, probe.New(InvalidArgument{})
 	}
 	if err := donut.listDonutBuckets(); err != nil {
-		return PartMetadata{}, iodine.New(err, errParams)
+		return PartMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return PartMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return PartMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	bucketMeta, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return PartMetadata{}, iodine.New(err, errParams)
+		return PartMetadata{}, err.Trace()
 	}
 	if _, ok := bucketMeta.Buckets[bucket].Multiparts[object]; !ok {
-		return PartMetadata{}, iodine.New(InvalidUploadID{UploadID: uploadID}, nil)
+		return PartMetadata{}, probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 	if _, ok := bucketMeta.Buckets[bucket].BucketObjects[object]; ok {
-		return PartMetadata{}, iodine.New(ObjectExists{Object: object}, errParams)
+		return PartMetadata{}, probe.New(ObjectExists{Object: object})
 	}
 	objectPart := object + "/" + "multipart" + "/" + strconv.Itoa(partID)
 	objmetadata, err := donut.buckets[bucket].WriteObject(objectPart, reader, size, expectedMD5Sum, metadata, signature)
 	if err != nil {
-		return PartMetadata{}, iodine.New(err, errParams)
+		return PartMetadata{}, err.Trace()
 	}
 	partMetadata := PartMetadata{
 		PartNumber:   partID,
@@ -212,74 +197,61 @@ func (donut API) putObjectPart(bucket, object, expectedMD5Sum, uploadID string,
 	multipartSession.Parts[strconv.Itoa(partID)] = partMetadata
 	bucketMeta.Buckets[bucket].Multiparts[object] = multipartSession
 	if err := donut.setDonutBucketMetadata(bucketMeta); err != nil {
-		return PartMetadata{}, iodine.New(err, errParams)
+		return PartMetadata{}, err.Trace()
 	}
 	return partMetadata, nil
 }
 
 // getObject - get object
-func (donut API) getObject(bucket, object string) (reader io.ReadCloser, size int64, err error) {
-	errParams := map[string]string{
-		"bucket": bucket,
-		"object": object,
-	}
+func (donut API) getObject(bucket, object string) (reader io.ReadCloser, size int64, err *probe.Error) {
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return nil, 0, iodine.New(InvalidArgument{}, errParams)
+		return nil, 0, probe.New(InvalidArgument{})
 	}
 	if object == "" || strings.TrimSpace(object) == "" {
-		return nil, 0, iodine.New(InvalidArgument{}, errParams)
+		return nil, 0, probe.New(InvalidArgument{})
 	}
 	if err := donut.listDonutBuckets(); err != nil {
-		return nil, 0, iodine.New(err, nil)
+		return nil, 0, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return nil, 0, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return nil, 0, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	return donut.buckets[bucket].ReadObject(object)
 }
 
 // getObjectMetadata - get object metadata
-func (donut API) getObjectMetadata(bucket, object string) (ObjectMetadata, error) {
-	errParams := map[string]string{
-		"bucket": bucket,
-		"object": object,
-	}
+func (donut API) getObjectMetadata(bucket, object string) (ObjectMetadata, *probe.Error) {
 	if err := donut.listDonutBuckets(); err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return ObjectMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	bucketMeta, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	if _, ok := bucketMeta.Buckets[bucket].BucketObjects[object]; !ok {
-		return ObjectMetadata{}, iodine.New(ObjectNotFound{Object: object}, errParams)
+		return ObjectMetadata{}, probe.New(ObjectNotFound{Object: object})
 	}
 	objectMetadata, err := donut.buckets[bucket].GetObjectMetadata(object)
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, nil)
+		return ObjectMetadata{}, err.Trace()
 	}
 	return objectMetadata, nil
 }
 
 // newMultipartUpload - new multipart upload request
-func (donut API) newMultipartUpload(bucket, object, contentType string) (string, error) {
-	errParams := map[string]string{
-		"bucket":      bucket,
-		"object":      object,
-		"contentType": contentType,
-	}
+func (donut API) newMultipartUpload(bucket, object, contentType string) (string, *probe.Error) {
 	if err := donut.listDonutBuckets(); err != nil {
-		return "", iodine.New(err, errParams)
+		return "", err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return "", iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return "", probe.New(BucketNotFound{Bucket: bucket})
 	}
 	allbuckets, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return "", iodine.New(err, errParams)
+		return "", err.Trace()
 	}
 	bucketMetadata := allbuckets.Buckets[bucket]
 	multiparts := make(map[string]MultiPartSession)
@@ -302,40 +274,36 @@ func (donut API) newMultipartUpload(bucket, object, contentType string) (string,
 	allbuckets.Buckets[bucket] = bucketMetadata
 
 	if err := donut.setDonutBucketMetadata(allbuckets); err != nil {
-		return "", iodine.New(err, errParams)
+		return "", err.Trace()
 	}
 
 	return uploadID, nil
 }
 
 // listObjectParts list all object parts
-func (donut API) listObjectParts(bucket, object string, resources ObjectResourcesMetadata) (ObjectResourcesMetadata, error) {
-	errParams := map[string]string{
-		"bucket": bucket,
-		"object": object,
-	}
+func (donut API) listObjectParts(bucket, object string, resources ObjectResourcesMetadata) (ObjectResourcesMetadata, *probe.Error) {
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return ObjectResourcesMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return ObjectResourcesMetadata{}, probe.New(InvalidArgument{})
 	}
 	if object == "" || strings.TrimSpace(object) == "" {
-		return ObjectResourcesMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return ObjectResourcesMetadata{}, probe.New(InvalidArgument{})
 	}
 	if err := donut.listDonutBuckets(); err != nil {
-		return ObjectResourcesMetadata{}, iodine.New(err, nil)
+		return ObjectResourcesMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return ObjectResourcesMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return ObjectResourcesMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	allBuckets, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return ObjectResourcesMetadata{}, iodine.New(err, errParams)
+		return ObjectResourcesMetadata{}, err.Trace()
 	}
 	bucketMetadata := allBuckets.Buckets[bucket]
 	if _, ok := bucketMetadata.Multiparts[object]; !ok {
-		return ObjectResourcesMetadata{}, iodine.New(InvalidUploadID{UploadID: resources.UploadID}, errParams)
+		return ObjectResourcesMetadata{}, probe.New(InvalidUploadID{UploadID: resources.UploadID})
 	}
 	if bucketMetadata.Multiparts[object].UploadID != resources.UploadID {
-		return ObjectResourcesMetadata{}, iodine.New(InvalidUploadID{UploadID: resources.UploadID}, errParams)
+		return ObjectResourcesMetadata{}, probe.New(InvalidUploadID{UploadID: resources.UploadID})
 	}
 	objectResourcesMetadata := resources
 	objectResourcesMetadata.Bucket = bucket
@@ -358,7 +326,7 @@ func (donut API) listObjectParts(bucket, object string, resources ObjectResource
 		}
 		part, ok := bucketMetadata.Multiparts[object].Parts[strconv.Itoa(i)]
 		if !ok {
-			return ObjectResourcesMetadata{}, iodine.New(InvalidPart{}, nil)
+			return ObjectResourcesMetadata{}, probe.New(InvalidPart{})
 		}
 		parts = append(parts, &part)
 	}
@@ -368,58 +336,57 @@ func (donut API) listObjectParts(bucket, object string, resources ObjectResource
 }
 
 // completeMultipartUpload complete an incomplete multipart upload
-func (donut API) completeMultipartUpload(bucket, object, uploadID string, data io.Reader, signature *Signature) (ObjectMetadata, error) {
-	errParams := map[string]string{
-		"bucket":   bucket,
-		"object":   object,
-		"uploadID": uploadID,
-	}
+func (donut API) completeMultipartUpload(bucket, object, uploadID string, data io.Reader, signature *Signature) (ObjectMetadata, *probe.Error) {
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return ObjectMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidArgument{})
 	}
 	if object == "" || strings.TrimSpace(object) == "" {
-		return ObjectMetadata{}, iodine.New(InvalidArgument{}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidArgument{})
 	}
 	if err := donut.listDonutBuckets(); err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return ObjectMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	allBuckets, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+		return ObjectMetadata{}, err.Trace()
 	}
 	bucketMetadata := allBuckets.Buckets[bucket]
 	if _, ok := bucketMetadata.Multiparts[object]; !ok {
-		return ObjectMetadata{}, iodine.New(InvalidUploadID{UploadID: uploadID}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 	if bucketMetadata.Multiparts[object].UploadID != uploadID {
-		return ObjectMetadata{}, iodine.New(InvalidUploadID{UploadID: uploadID}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidUploadID{UploadID: uploadID})
 	}
-	partBytes, err := ioutil.ReadAll(data)
-	if err != nil {
-		return ObjectMetadata{}, iodine.New(err, errParams)
+	var partBytes []byte
+	{
+		var err error
+		partBytes, err = ioutil.ReadAll(data)
+		if err != nil {
+			return ObjectMetadata{}, probe.New(err)
+		}
 	}
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch(hex.EncodeToString(sha256.Sum256(partBytes)[:]))
 		if err != nil {
-			return ObjectMetadata{}, iodine.New(err, errParams)
+			return ObjectMetadata{}, err.Trace()
 		}
 		if !ok {
-			return ObjectMetadata{}, iodine.New(SignatureDoesNotMatch{}, errParams)
+			return ObjectMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 	parts := &CompleteMultipartUpload{}
 	if err := xml.Unmarshal(partBytes, parts); err != nil {
-		return ObjectMetadata{}, iodine.New(MalformedXML{}, errParams)
+		return ObjectMetadata{}, probe.New(MalformedXML{})
 	}
 	if !sort.IsSorted(completedParts(parts.Part)) {
-		return ObjectMetadata{}, iodine.New(InvalidPartOrder{}, errParams)
+		return ObjectMetadata{}, probe.New(InvalidPartOrder{})
 	}
 	for _, part := range parts.Part {
 		if strings.Trim(part.ETag, "\"") != bucketMetadata.Multiparts[object].Parts[strconv.Itoa(part.PartNumber)].ETag {
-			return ObjectMetadata{}, iodine.New(InvalidPart{}, errParams)
+			return ObjectMetadata{}, probe.New(InvalidPart{})
 		}
 	}
 	var finalETagBytes []byte
@@ -428,7 +395,7 @@ func (donut API) completeMultipartUpload(bucket, object, uploadID string, data i
 	for _, part := range bucketMetadata.Multiparts[object].Parts {
 		partETagBytes, err := hex.DecodeString(part.ETag)
 		if err != nil {
-			return ObjectMetadata{}, iodine.New(err, errParams)
+			return ObjectMetadata{}, probe.New(err)
 		}
 		finalETagBytes = append(finalETagBytes, partETagBytes...)
 		finalSize += part.Size
@@ -444,19 +411,16 @@ func (donut API) completeMultipartUpload(bucket, object, uploadID string, data i
 }
 
 // listMultipartUploads list all multipart uploads
-func (donut API) listMultipartUploads(bucket string, resources BucketMultipartResourcesMetadata) (BucketMultipartResourcesMetadata, error) {
-	errParams := map[string]string{
-		"bucket": bucket,
-	}
+func (donut API) listMultipartUploads(bucket string, resources BucketMultipartResourcesMetadata) (BucketMultipartResourcesMetadata, *probe.Error) {
 	if err := donut.listDonutBuckets(); err != nil {
-		return BucketMultipartResourcesMetadata{}, iodine.New(err, errParams)
+		return BucketMultipartResourcesMetadata{}, err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return BucketMultipartResourcesMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return BucketMultipartResourcesMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	allbuckets, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return BucketMultipartResourcesMetadata{}, iodine.New(err, errParams)
+		return BucketMultipartResourcesMetadata{}, err.Trace()
 	}
 	bucketMetadata := allbuckets.Buckets[bucket]
 	var uploads []*UploadMetadata
@@ -505,34 +469,29 @@ func (donut API) listMultipartUploads(bucket string, resources BucketMultipartRe
 }
 
 // abortMultipartUpload - abort a incomplete multipart upload
-func (donut API) abortMultipartUpload(bucket, object, uploadID string) error {
-	errParams := map[string]string{
-		"bucket":   bucket,
-		"object":   object,
-		"uploadID": uploadID,
-	}
+func (donut API) abortMultipartUpload(bucket, object, uploadID string) *probe.Error {
 	if err := donut.listDonutBuckets(); err != nil {
-		return iodine.New(err, errParams)
+		return err.Trace()
 	}
 	if _, ok := donut.buckets[bucket]; !ok {
-		return iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return probe.New(BucketNotFound{Bucket: bucket})
 	}
 	allbuckets, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return iodine.New(err, errParams)
+		return err.Trace()
 	}
 	bucketMetadata := allbuckets.Buckets[bucket]
 	if _, ok := bucketMetadata.Multiparts[object]; !ok {
-		return iodine.New(InvalidUploadID{UploadID: uploadID}, errParams)
+		return probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 	if bucketMetadata.Multiparts[object].UploadID != uploadID {
-		return iodine.New(InvalidUploadID{UploadID: uploadID}, errParams)
+		return probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 	delete(bucketMetadata.Multiparts, object)
 
 	allbuckets.Buckets[bucket] = bucketMetadata
 	if err := donut.setDonutBucketMetadata(allbuckets); err != nil {
-		return iodine.New(err, errParams)
+		return err.Trace()
 	}
 
 	return nil
@@ -541,18 +500,18 @@ func (donut API) abortMultipartUpload(bucket, object, uploadID string) error {
 //// internal functions
 
 // getBucketMetadataWriters -
-func (donut API) getBucketMetadataWriters() ([]io.WriteCloser, error) {
+func (donut API) getBucketMetadataWriters() ([]io.WriteCloser, *probe.Error) {
 	var writers []io.WriteCloser
 	for _, node := range donut.nodes {
 		disks, err := node.ListDisks()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 		writers = make([]io.WriteCloser, len(disks))
 		for order, disk := range disks {
 			bucketMetaDataWriter, err := disk.CreateFile(filepath.Join(donut.config.DonutName, bucketMetadataConfig))
 			if err != nil {
-				return nil, iodine.New(err, nil)
+				return nil, err.Trace()
 			}
 			writers[order] = bucketMetaDataWriter
 		}
@@ -561,14 +520,14 @@ func (donut API) getBucketMetadataWriters() ([]io.WriteCloser, error) {
 }
 
 // getBucketMetadataReaders - readers are returned in map rather than slice
-func (donut API) getBucketMetadataReaders() (map[int]io.ReadCloser, error) {
+func (donut API) getBucketMetadataReaders() (map[int]io.ReadCloser, *probe.Error) {
 	readers := make(map[int]io.ReadCloser)
 	disks := make(map[int]disk.Disk)
-	var err error
+	var err *probe.Error
 	for _, node := range donut.nodes {
 		nDisks, err := node.ListDisks()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 		for k, v := range nDisks {
 			disks[k] = v
@@ -583,22 +542,22 @@ func (donut API) getBucketMetadataReaders() (map[int]io.ReadCloser, error) {
 		readers[order] = bucketMetaDataReader
 	}
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	return readers, nil
 }
 
 // setDonutBucketMetadata -
-func (donut API) setDonutBucketMetadata(metadata *AllBuckets) error {
+func (donut API) setDonutBucketMetadata(metadata *AllBuckets) *probe.Error {
 	writers, err := donut.getBucketMetadataWriters()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	for _, writer := range writers {
 		jenc := json.NewEncoder(writer)
 		if err := jenc.Encode(metadata); err != nil {
 			CleanupWritersOnError(writers)
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 	}
 	for _, writer := range writers {
@@ -608,83 +567,85 @@ func (donut API) setDonutBucketMetadata(metadata *AllBuckets) error {
 }
 
 // getDonutBucketMetadata -
-func (donut API) getDonutBucketMetadata() (*AllBuckets, error) {
+func (donut API) getDonutBucketMetadata() (*AllBuckets, *probe.Error) {
 	metadata := &AllBuckets{}
-	var err error
 	readers, err := donut.getBucketMetadataReaders()
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 	for _, reader := range readers {
 		defer reader.Close()
 	}
-	for _, reader := range readers {
-		jenc := json.NewDecoder(reader)
-		if err = jenc.Decode(metadata); err == nil {
-			return metadata, nil
+	{
+		var err error
+		for _, reader := range readers {
+			jenc := json.NewDecoder(reader)
+			if err = jenc.Decode(metadata); err == nil {
+				return metadata, nil
+			}
 		}
+		return nil, probe.New(err)
 	}
-	return nil, iodine.New(err, nil)
 }
 
 // makeDonutBucket -
-func (donut API) makeDonutBucket(bucketName, acl string) error {
+func (donut API) makeDonutBucket(bucketName, acl string) *probe.Error {
 	if err := donut.listDonutBuckets(); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	if _, ok := donut.buckets[bucketName]; ok {
-		return iodine.New(BucketExists{Bucket: bucketName}, nil)
+		return probe.New(BucketExists{Bucket: bucketName})
 	}
 	bucket, bucketMetadata, err := newBucket(bucketName, acl, donut.config.DonutName, donut.nodes)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	nodeNumber := 0
 	donut.buckets[bucketName] = bucket
 	for _, node := range donut.nodes {
 		disks, err := node.ListDisks()
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		for order, disk := range disks {
 			bucketSlice := fmt.Sprintf("%s$%d$%d", bucketName, nodeNumber, order)
 			err := disk.MakeDir(filepath.Join(donut.config.DonutName, bucketSlice))
 			if err != nil {
-				return iodine.New(err, nil)
+				return err.Trace()
 			}
 		}
 		nodeNumber = nodeNumber + 1
 	}
 	metadata, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		if os.IsNotExist(iodine.ToError(err)) {
+		if os.IsNotExist(err.ToError()) {
 			metadata := new(AllBuckets)
 			metadata.Buckets = make(map[string]BucketMetadata)
 			metadata.Buckets[bucketName] = bucketMetadata
 			err = donut.setDonutBucketMetadata(metadata)
 			if err != nil {
-				return iodine.New(err, nil)
+				return err.Trace()
 			}
 			return nil
 		}
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	metadata.Buckets[bucketName] = bucketMetadata
 	err = donut.setDonutBucketMetadata(metadata)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	return nil
 }
 
 // listDonutBuckets -
-func (donut API) listDonutBuckets() error {
+func (donut API) listDonutBuckets() *probe.Error {
 	var disks map[int]disk.Disk
-	var err error
+	var err *probe.Error
 	for _, node := range donut.nodes {
 		disks, err = node.ListDisks()
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 	}
 	var dirs []os.FileInfo
@@ -696,18 +657,18 @@ func (donut API) listDonutBuckets() error {
 	}
 	// if all disks are missing then return error
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	for _, dir := range dirs {
 		splitDir := strings.Split(dir.Name(), "$")
 		if len(splitDir) < 3 {
-			return iodine.New(CorruptedBackend{Backend: dir.Name()}, nil)
+			return probe.New(CorruptedBackend{Backend: dir.Name()})
 		}
 		bucketName := splitDir[0]
 		// we dont need this once we cache from makeDonutBucket()
 		bucket, _, err := newBucket(bucketName, "private", donut.config.DonutName, donut.nodes)
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		donut.buckets[bucketName] = bucket
 	}

pkg/donut/donut-v2.go

@@ -34,7 +34,7 @@ import (
 	"github.com/minio/minio/pkg/crypto/sha256"
 	"github.com/minio/minio/pkg/donut/cache/data"
 	"github.com/minio/minio/pkg/donut/cache/metadata"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/quick"
 )
 
@@ -71,9 +71,9 @@ type storedBucket struct {
 }
 
 // New instantiate a new donut
-func New() (Interface, error) {
+func New() (Interface, *probe.Error) {
 	var conf *Config
-	var err error
+	var err *probe.Error
 	conf, err = LoadConfig()
 	if err != nil {
 		conf = &Config{
@@ -83,7 +83,7 @@ func New() (Interface, error) {
 			DonutName:   "",
 		}
 		if err := quick.CheckData(conf); err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 	}
 	a := API{config: conf}
@@ -98,17 +98,17 @@ func New() (Interface, error) {
 	if len(a.config.NodeDiskMap) > 0 {
 		for k, v := range a.config.NodeDiskMap {
 			if len(v) == 0 {
-				return nil, iodine.New(InvalidDisksArgument{}, nil)
+				return nil, probe.New(InvalidDisksArgument{})
 			}
 			err := a.AttachNode(k, v)
 			if err != nil {
-				return nil, iodine.New(err, nil)
+				return nil, err.Trace()
 			}
 		}
 		/// Initialization, populate all buckets into memory
 		buckets, err := a.listBuckets()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 		for k, v := range buckets {
 			var newBucket = storedBucket{}
@@ -126,58 +126,53 @@ func New() (Interface, error) {
 /// V2 API functions
 
 // GetObject - GET object from cache buffer
-func (donut API) GetObject(w io.Writer, bucket string, object string, start, length int64) (int64, error) {
+func (donut API) GetObject(w io.Writer, bucket string, object string, start, length int64) (int64, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
-	errParams := map[string]string{
-		"bucket": bucket,
-		"object": object,
-		"start":  strconv.FormatInt(start, 10),
-		"length": strconv.FormatInt(length, 10),
-	}
-
 	if !IsValidBucket(bucket) {
-		return 0, iodine.New(BucketNameInvalid{Bucket: bucket}, errParams)
+		return 0, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(object) {
-		return 0, iodine.New(ObjectNameInvalid{Object: object}, errParams)
+		return 0, probe.New(ObjectNameInvalid{Object: object})
 	}
 	if start < 0 {
-		return 0, iodine.New(InvalidRange{
+		return 0, probe.New(InvalidRange{
 			Start:  start,
 			Length: length,
-		}, errParams)
+		})
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return 0, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
+		return 0, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	objectKey := bucket + "/" + object
 	data, ok := donut.objects.Get(objectKey)
 	var written int64
-	var err error
 	if !ok {
 		if len(donut.config.NodeDiskMap) > 0 {
 			reader, size, err := donut.getObject(bucket, object)
 			if err != nil {
-				return 0, iodine.New(err, nil)
+				return 0, err.Trace()
 			}
 			if start > 0 {
 				if _, err := io.CopyN(ioutil.Discard, reader, start); err != nil {
-					return 0, iodine.New(err, errParams)
+					return 0, probe.New(err)
 				}
 			}
 			// new proxy writer to capture data read from disk
 			pw := NewProxyWriter(w)
-			if length > 0 {
-				written, err = io.CopyN(pw, reader, length)
-				if err != nil {
-					return 0, iodine.New(err, errParams)
-				}
-			} else {
-				written, err = io.CopyN(pw, reader, size)
-				if err != nil {
-					return 0, iodine.New(err, errParams)
+			{
+				var err error
+				if length > 0 {
+					written, err = io.CopyN(pw, reader, length)
+					if err != nil {
+						return 0, probe.New(err)
+					}
+				} else {
+					written, err = io.CopyN(pw, reader, size)
+					if err != nil {
+						return 0, probe.New(err)
+					}
 				}
 			}
 			/// cache object read from disk
@@ -185,83 +180,86 @@ func (donut API) GetObject(w io.Writer, bucket string, object string, start, len
 			pw.writtenBytes = nil
 			go debug.FreeOSMemory()
 			if !ok {
-				return 0, iodine.New(InternalError{}, errParams)
+				return 0, probe.New(InternalError{})
 			}
 			return written, nil
 		}
-		return 0, iodine.New(ObjectNotFound{Object: object}, errParams)
+		return 0, probe.New(ObjectNotFound{Object: object})
 	}
-	if start == 0 && length == 0 {
-		written, err = io.CopyN(w, bytes.NewBuffer(data), int64(donut.objects.Len(objectKey)))
-		if err != nil {
-			return 0, iodine.New(err, nil)
-		}
-	} else {
-		written, err = io.CopyN(w, bytes.NewBuffer(data[start:]), length)
-		if err != nil {
-			return 0, iodine.New(err, nil)
+	{
+		var err error
+		if start == 0 && length == 0 {
+			written, err = io.CopyN(w, bytes.NewBuffer(data), int64(donut.objects.Len(objectKey)))
+			if err != nil {
+				return 0, probe.New(err)
+			}
+		} else {
+			written, err = io.CopyN(w, bytes.NewBuffer(data[start:]), length)
+			if err != nil {
+				return 0, probe.New(err)
+			}
 		}
+		return written, nil
 	}
-	return written, nil
 }
 
 // GetBucketMetadata -
-func (donut API) GetBucketMetadata(bucket string, signature *Signature) (BucketMetadata, error) {
+func (donut API) GetBucketMetadata(bucket string, signature *Signature) (BucketMetadata, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return BucketMetadata{}, iodine.New(err, nil)
+			return BucketMetadata{}, err.Trace()
 		}
 		if !ok {
-			return BucketMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return BucketMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	if !IsValidBucket(bucket) {
-		return BucketMetadata{}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return BucketMetadata{}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !donut.storedBuckets.Exists(bucket) {
 		if len(donut.config.NodeDiskMap) > 0 {
 			bucketMetadata, err := donut.getBucketMetadata(bucket)
 			if err != nil {
-				return BucketMetadata{}, iodine.New(err, nil)
+				return BucketMetadata{}, err.Trace()
 			}
 			storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 			storedBucket.bucketMetadata = bucketMetadata
 			donut.storedBuckets.Set(bucket, storedBucket)
 		}
-		return BucketMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return BucketMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	return donut.storedBuckets.Get(bucket).(storedBucket).bucketMetadata, nil
 }
 
 // SetBucketMetadata -
-func (donut API) SetBucketMetadata(bucket string, metadata map[string]string, signature *Signature) error {
+func (donut API) SetBucketMetadata(bucket string, metadata map[string]string, signature *Signature) *probe.Error {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		if !ok {
-			return iodine.New(SignatureDoesNotMatch{}, nil)
+			return probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	if !IsValidBucket(bucket) {
-		return iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return probe.New(BucketNotFound{Bucket: bucket})
 	}
 	if len(donut.config.NodeDiskMap) > 0 {
 		if err := donut.setBucketMetadata(bucket, metadata); err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
@@ -271,26 +269,26 @@ func (donut API) SetBucketMetadata(bucket string, metadata map[string]string, si
 }
 
 // isMD5SumEqual - returns error if md5sum mismatches, success its `nil`
-func isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) error {
+func isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) *probe.Error {
 	if strings.TrimSpace(expectedMD5Sum) != "" && strings.TrimSpace(actualMD5Sum) != "" {
 		expectedMD5SumBytes, err := hex.DecodeString(expectedMD5Sum)
 		if err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 		actualMD5SumBytes, err := hex.DecodeString(actualMD5Sum)
 		if err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 		if !bytes.Equal(expectedMD5SumBytes, actualMD5SumBytes) {
-			return iodine.New(BadDigest{}, nil)
+			return probe.New(BadDigest{})
 		}
 		return nil
 	}
-	return iodine.New(InvalidArgument{}, nil)
+	return probe.New(InvalidArgument{})
 }
 
 // CreateObject - create an object
-func (donut API) CreateObject(bucket, key, expectedMD5Sum string, size int64, data io.Reader, metadata map[string]string, signature *Signature) (ObjectMetadata, error) {
+func (donut API) CreateObject(bucket, key, expectedMD5Sum string, size int64, data io.Reader, metadata map[string]string, signature *Signature) (ObjectMetadata, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
@@ -299,35 +297,35 @@ func (donut API) CreateObject(bucket, key, expectedMD5Sum string, size int64, da
 	// free
 	debug.FreeOSMemory()
 
-	return objectMetadata, iodine.New(err, nil)
+	return objectMetadata, err.Trace()
 }
 
 // createObject - PUT object to cache buffer
-func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, size int64, data io.Reader, signature *Signature) (ObjectMetadata, error) {
+func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, size int64, data io.Reader, signature *Signature) (ObjectMetadata, *probe.Error) {
 	if len(donut.config.NodeDiskMap) == 0 {
 		if size > int64(donut.config.MaxSize) {
 			generic := GenericObjectError{Bucket: bucket, Object: key}
-			return ObjectMetadata{}, iodine.New(EntityTooLarge{
+			return ObjectMetadata{}, probe.New(EntityTooLarge{
 				GenericObjectError: generic,
 				Size:               strconv.FormatInt(size, 10),
 				MaxSize:            strconv.FormatUint(donut.config.MaxSize, 10),
-			}, nil)
+			})
 		}
 	}
 	if !IsValidBucket(bucket) {
-		return ObjectMetadata{}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
-		return ObjectMetadata{}, iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return ObjectMetadata{}, probe.New(ObjectNameInvalid{Object: key})
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	// get object key
 	objectKey := bucket + "/" + key
 	if _, ok := storedBucket.objectMetadata[objectKey]; ok == true {
-		return ObjectMetadata{}, iodine.New(ObjectExists{Object: key}, nil)
+		return ObjectMetadata{}, probe.New(ObjectExists{Object: key})
 	}
 
 	if contentType == "" {
@@ -338,7 +336,7 @@ func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, s
 		expectedMD5SumBytes, err := base64.StdEncoding.DecodeString(strings.TrimSpace(expectedMD5Sum))
 		if err != nil {
 			// pro-actively close the connection
-			return ObjectMetadata{}, iodine.New(InvalidDigest{Md5: expectedMD5Sum}, nil)
+			return ObjectMetadata{}, probe.New(InvalidDigest{Md5: expectedMD5Sum})
 		}
 		expectedMD5Sum = hex.EncodeToString(expectedMD5SumBytes)
 	}
@@ -357,7 +355,7 @@ func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, s
 			signature,
 		)
 		if err != nil {
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		storedBucket.objectMetadata[objectKey] = objMetadata
 		donut.storedBuckets.Set(bucket, storedBucket)
@@ -377,7 +375,7 @@ func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, s
 		sha256hash.Write(byteBuffer[0:length])
 		ok := donut.objects.Append(objectKey, byteBuffer[0:length])
 		if !ok {
-			return ObjectMetadata{}, iodine.New(InternalError{}, nil)
+			return ObjectMetadata{}, probe.New(InternalError{})
 		}
 		totalLength += int64(length)
 		go debug.FreeOSMemory()
@@ -385,26 +383,26 @@ func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, s
 	if totalLength != size {
 		// Delete perhaps the object is already saved, due to the nature of append()
 		donut.objects.Delete(objectKey)
-		return ObjectMetadata{}, iodine.New(IncompleteBody{Bucket: bucket, Object: key}, nil)
+		return ObjectMetadata{}, probe.New(IncompleteBody{Bucket: bucket, Object: key})
 	}
 	if err != io.EOF {
-		return ObjectMetadata{}, iodine.New(err, nil)
+		return ObjectMetadata{}, probe.New(err)
 	}
 	md5SumBytes := hash.Sum(nil)
 	md5Sum := hex.EncodeToString(md5SumBytes)
 	// Verify if the written object is equal to what is expected, only if it is requested as such
 	if strings.TrimSpace(expectedMD5Sum) != "" {
 		if err := isMD5SumEqual(strings.TrimSpace(expectedMD5Sum), md5Sum); err != nil {
-			return ObjectMetadata{}, iodine.New(BadDigest{}, nil)
+			return ObjectMetadata{}, probe.New(BadDigest{})
 		}
 	}
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch(hex.EncodeToString(sha256hash.Sum(nil)))
 		if err != nil {
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		if !ok {
-			return ObjectMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return ObjectMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
@@ -426,7 +424,7 @@ func (donut API) createObject(bucket, key, contentType, expectedMD5Sum string, s
 }
 
 // MakeBucket - create bucket in cache
-func (donut API) MakeBucket(bucketName, acl string, location io.Reader, signature *Signature) error {
+func (donut API) MakeBucket(bucketName, acl string, location io.Reader, signature *Signature) *probe.Error {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
@@ -435,7 +433,7 @@ func (donut API) MakeBucket(bucketName, acl string, location io.Reader, signatur
 	if location != nil {
 		locationConstraintBytes, err := ioutil.ReadAll(location)
 		if err != nil {
-			return iodine.New(InternalError{}, nil)
+			return probe.New(InternalError{})
 		}
 		locationSum = hex.EncodeToString(sha256.Sum256(locationConstraintBytes)[:])
 	}
@@ -443,24 +441,24 @@ func (donut API) MakeBucket(bucketName, acl string, location io.Reader, signatur
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch(locationSum)
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		if !ok {
-			return iodine.New(SignatureDoesNotMatch{}, nil)
+			return probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	if donut.storedBuckets.Stats().Items == totalBuckets {
-		return iodine.New(TooManyBuckets{Bucket: bucketName}, nil)
+		return probe.New(TooManyBuckets{Bucket: bucketName})
 	}
 	if !IsValidBucket(bucketName) {
-		return iodine.New(BucketNameInvalid{Bucket: bucketName}, nil)
+		return probe.New(BucketNameInvalid{Bucket: bucketName})
 	}
 	if !IsValidBucketACL(acl) {
-		return iodine.New(InvalidACL{ACL: acl}, nil)
+		return probe.New(InvalidACL{ACL: acl})
 	}
 	if donut.storedBuckets.Exists(bucketName) {
-		return iodine.New(BucketExists{Bucket: bucketName}, nil)
+		return probe.New(BucketExists{Bucket: bucketName})
 	}
 
 	if strings.TrimSpace(acl) == "" {
@@ -469,7 +467,7 @@ func (donut API) MakeBucket(bucketName, acl string, location io.Reader, signatur
 	}
 	if len(donut.config.NodeDiskMap) > 0 {
 		if err := donut.makeBucket(bucketName, BucketACL(acl)); err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 	}
 	var newBucket = storedBucket{}
@@ -485,28 +483,28 @@ func (donut API) MakeBucket(bucketName, acl string, location io.Reader, signatur
 }
 
 // ListObjects - list objects from cache
-func (donut API) ListObjects(bucket string, resources BucketResourcesMetadata, signature *Signature) ([]ObjectMetadata, BucketResourcesMetadata, error) {
+func (donut API) ListObjects(bucket string, resources BucketResourcesMetadata, signature *Signature) ([]ObjectMetadata, BucketResourcesMetadata, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return nil, BucketResourcesMetadata{}, iodine.New(err, nil)
+			return nil, BucketResourcesMetadata{}, err.Trace()
 		}
 		if !ok {
-			return nil, BucketResourcesMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return nil, BucketResourcesMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	if !IsValidBucket(bucket) {
-		return nil, BucketResourcesMetadata{IsTruncated: false}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return nil, BucketResourcesMetadata{IsTruncated: false}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidPrefix(resources.Prefix) {
-		return nil, BucketResourcesMetadata{IsTruncated: false}, iodine.New(ObjectNameInvalid{Object: resources.Prefix}, nil)
+		return nil, BucketResourcesMetadata{IsTruncated: false}, probe.New(ObjectNameInvalid{Object: resources.Prefix})
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return nil, BucketResourcesMetadata{IsTruncated: false}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return nil, BucketResourcesMetadata{IsTruncated: false}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	var results []ObjectMetadata
 	var keys []string
@@ -519,7 +517,7 @@ func (donut API) ListObjects(bucket string, resources BucketResourcesMetadata, s
 			resources.Maxkeys,
 		)
 		if err != nil {
-			return nil, BucketResourcesMetadata{IsTruncated: false}, iodine.New(err, nil)
+			return nil, BucketResourcesMetadata{IsTruncated: false}, probe.New(err)
 		}
 		resources.CommonPrefixes = listObjects.CommonPrefixes
 		resources.IsTruncated = listObjects.IsTruncated
@@ -588,17 +586,17 @@ func (b byBucketName) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }
 func (b byBucketName) Less(i, j int) bool { return b[i].Name < b[j].Name }
 
 // ListBuckets - List buckets from cache
-func (donut API) ListBuckets(signature *Signature) ([]BucketMetadata, error) {
+func (donut API) ListBuckets(signature *Signature) ([]BucketMetadata, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 		if !ok {
-			return nil, iodine.New(SignatureDoesNotMatch{}, nil)
+			return nil, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
@@ -606,7 +604,7 @@ func (donut API) ListBuckets(signature *Signature) ([]BucketMetadata, error) {
 	if len(donut.config.NodeDiskMap) > 0 {
 		buckets, err := donut.listBuckets()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 		for _, bucketMetadata := range buckets {
 			results = append(results, bucketMetadata)
@@ -622,29 +620,29 @@ func (donut API) ListBuckets(signature *Signature) ([]BucketMetadata, error) {
 }
 
 // GetObjectMetadata - get object metadata from cache
-func (donut API) GetObjectMetadata(bucket, key string, signature *Signature) (ObjectMetadata, error) {
+func (donut API) GetObjectMetadata(bucket, key string, signature *Signature) (ObjectMetadata, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		if !ok {
-			return ObjectMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return ObjectMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	// check if bucket exists
 	if !IsValidBucket(bucket) {
-		return ObjectMetadata{}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
-		return ObjectMetadata{}, iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return ObjectMetadata{}, probe.New(ObjectNameInvalid{Object: key})
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	objectKey := bucket + "/" + key
@@ -654,14 +652,14 @@ func (donut API) GetObjectMetadata(bucket, key string, signature *Signature) (Ob
 	if len(donut.config.NodeDiskMap) > 0 {
 		objMetadata, err := donut.getObjectMetadata(bucket, key)
 		if err != nil {
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		// update
 		storedBucket.objectMetadata[objectKey] = objMetadata
 		donut.storedBuckets.Set(bucket, storedBucket)
 		return objMetadata, nil
 	}
-	return ObjectMetadata{}, iodine.New(ObjectNotFound{Object: key}, nil)
+	return ObjectMetadata{}, probe.New(ObjectNotFound{Object: key})
 }
 
 // evictedObject callback function called when an item is evicted from memory

pkg/donut/encoder.go

@@ -18,10 +18,9 @@ package donut
 
 import (
 	"io"
-	"strconv"
 
 	encoding "github.com/minio/minio/pkg/erasure"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // encoder internal struct
@@ -32,74 +31,71 @@ type encoder struct {
 }
 
 // getErasureTechnique - convert technique string into Technique type
-func getErasureTechnique(technique string) (encoding.Technique, error) {
+func getErasureTechnique(technique string) (encoding.Technique, *probe.Error) {
 	switch true {
 	case technique == "Cauchy":
 		return encoding.Cauchy, nil
 	case technique == "Vandermonde":
 		return encoding.Cauchy, nil
 	default:
-		return encoding.None, iodine.New(InvalidErasureTechnique{Technique: technique}, nil)
+		return encoding.None, probe.New(InvalidErasureTechnique{Technique: technique})
 	}
 }
 
 // newEncoder - instantiate a new encoder
-func newEncoder(k, m uint8, technique string) (encoder, error) {
-	errParams := map[string]string{
-		"k":         strconv.FormatUint(uint64(k), 10),
-		"m":         strconv.FormatUint(uint64(m), 10),
-		"technique": technique,
-	}
+func newEncoder(k, m uint8, technique string) (encoder, *probe.Error) {
 	e := encoder{}
 	t, err := getErasureTechnique(technique)
 	if err != nil {
-		return encoder{}, iodine.New(err, errParams)
+		return encoder{}, err.Trace()
 	}
-	params, err := encoding.ValidateParams(k, m, t)
-	if err != nil {
-		return encoder{}, iodine.New(err, errParams)
+	{
+		params, err := encoding.ValidateParams(k, m, t)
+		if err != nil {
+			return encoder{}, probe.New(err)
+		}
+		e.encoder = encoding.NewErasure(params)
+		e.k = k
+		e.m = m
+		e.technique = t
+		return e, nil
 	}
-	e.encoder = encoding.NewErasure(params)
-	e.k = k
-	e.m = m
-	e.technique = t
-	return e, nil
 }
 
 // TODO - think again if this is needed
 // GetEncodedBlockLen - wrapper around erasure function with the same name
-func (e encoder) GetEncodedBlockLen(dataLength int) (int, error) {
+func (e encoder) GetEncodedBlockLen(dataLength int) (int, *probe.Error) {
 	if dataLength <= 0 {
-		return 0, iodine.New(InvalidArgument{}, nil)
+		return 0, probe.New(InvalidArgument{})
 	}
 	return encoding.GetEncodedBlockLen(dataLength, e.k), nil
 }
 
 // Encode - erasure code input bytes
-func (e encoder) Encode(data []byte) (encodedData [][]byte, err error) {
+func (e encoder) Encode(data []byte) ([][]byte, *probe.Error) {
 	if data == nil {
-		return nil, iodine.New(InvalidArgument{}, nil)
+		return nil, probe.New(InvalidArgument{})
 	}
-	encodedData, err = e.encoder.Encode(data)
+	encodedData, err := e.encoder.Encode(data)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	return encodedData, nil
 }
 
-func (e encoder) EncodeStream(data io.Reader, size int64) (encodedData [][]byte, inputData []byte, err error) {
-	encodedData, inputData, err = e.encoder.EncodeStream(data, size)
+func (e encoder) EncodeStream(data io.Reader, size int64) ([][]byte, []byte, *probe.Error) {
+	encodedData, inputData, err := e.encoder.EncodeStream(data, size)
 	if err != nil {
-		return nil, nil, iodine.New(err, nil)
+		return nil, nil, probe.New(err)
 	}
 	return encodedData, inputData, nil
 }
 
 // Decode - erasure decode input encoded bytes
-func (e encoder) Decode(encodedData [][]byte, dataLength int) (data []byte, err error) {
+func (e encoder) Decode(encodedData [][]byte, dataLength int) ([]byte, *probe.Error) {
 	decodedData, err := e.encoder.Decode(encodedData, dataLength)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	return decodedData, nil
 }

pkg/donut/heal.go

@@ -22,23 +22,23 @@ import (
 	"path/filepath"
 
 	"github.com/minio/minio/pkg/donut/disk"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // healBuckets heal bucket slices
-func (donut API) healBuckets() error {
+func (donut API) healBuckets() *probe.Error {
 	if err := donut.listDonutBuckets(); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	bucketMetadata, err := donut.getDonutBucketMetadata()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	disks := make(map[int]disk.Disk)
 	for _, node := range donut.nodes {
 		nDisks, err := node.ListDisks()
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		for k, v := range nDisks {
 			disks[k] = v
@@ -49,18 +49,18 @@ func (donut API) healBuckets() error {
 			disk.MakeDir(donut.config.DonutName)
 			bucketMetadataWriter, err := disk.CreateFile(filepath.Join(donut.config.DonutName, bucketMetadataConfig))
 			if err != nil {
-				return iodine.New(err, nil)
+				return err.Trace()
 			}
 			defer bucketMetadataWriter.Close()
 			jenc := json.NewEncoder(bucketMetadataWriter)
 			if err := jenc.Encode(bucketMetadata); err != nil {
-				return iodine.New(err, nil)
+				return probe.New(err)
 			}
 			for bucket := range bucketMetadata.Buckets {
 				bucketSlice := fmt.Sprintf("%s$0$%d", bucket, order) // TODO handle node slices
 				err := disk.MakeDir(filepath.Join(donut.config.DonutName, bucketSlice))
 				if err != nil {
-					return iodine.New(err, nil)
+					return err.Trace()
 				}
 			}
 		}

pkg/donut/interfaces.go

@@ -16,7 +16,11 @@
 
 package donut
 
-import "io"
+import (
+	"io"
+
+	"github.com/minio/minio/pkg/probe"
+)
 
 // Collection of Donut specification interfaces
 
@@ -29,39 +33,39 @@ type Interface interface {
 // CloudStorage is a donut cloud storage interface
 type CloudStorage interface {
 	// Storage service operations
-	GetBucketMetadata(bucket string, signature *Signature) (BucketMetadata, error)
-	SetBucketMetadata(bucket string, metadata map[string]string, signature *Signature) error
-	ListBuckets(signature *Signature) ([]BucketMetadata, error)
-	MakeBucket(bucket string, ACL string, location io.Reader, signature *Signature) error
+	GetBucketMetadata(bucket string, signature *Signature) (BucketMetadata, *probe.Error)
+	SetBucketMetadata(bucket string, metadata map[string]string, signature *Signature) *probe.Error
+	ListBuckets(signature *Signature) ([]BucketMetadata, *probe.Error)
+	MakeBucket(bucket string, ACL string, location io.Reader, signature *Signature) *probe.Error
 
 	// Bucket operations
-	ListObjects(string, BucketResourcesMetadata, *Signature) ([]ObjectMetadata, BucketResourcesMetadata, error)
+	ListObjects(string, BucketResourcesMetadata, *Signature) ([]ObjectMetadata, BucketResourcesMetadata, *probe.Error)
 
 	// Object operations
-	GetObject(w io.Writer, bucket, object string, start, length int64) (int64, error)
-	GetObjectMetadata(bucket, object string, signature *Signature) (ObjectMetadata, error)
+	GetObject(w io.Writer, bucket, object string, start, length int64) (int64, *probe.Error)
+	GetObjectMetadata(bucket, object string, signature *Signature) (ObjectMetadata, *probe.Error)
 	// bucket, object, expectedMD5Sum, size, reader, metadata, signature
-	CreateObject(string, string, string, int64, io.Reader, map[string]string, *Signature) (ObjectMetadata, error)
+	CreateObject(string, string, string, int64, io.Reader, map[string]string, *Signature) (ObjectMetadata, *probe.Error)
 
 	Multipart
 }
 
 // Multipart API
 type Multipart interface {
-	NewMultipartUpload(bucket, key, contentType string, signature *Signature) (string, error)
-	AbortMultipartUpload(bucket, key, uploadID string, signature *Signature) error
-	CreateObjectPart(string, string, string, int, string, string, int64, io.Reader, *Signature) (string, error)
-	CompleteMultipartUpload(bucket, key, uploadID string, data io.Reader, signature *Signature) (ObjectMetadata, error)
-	ListMultipartUploads(string, BucketMultipartResourcesMetadata, *Signature) (BucketMultipartResourcesMetadata, error)
-	ListObjectParts(string, string, ObjectResourcesMetadata, *Signature) (ObjectResourcesMetadata, error)
+	NewMultipartUpload(bucket, key, contentType string, signature *Signature) (string, *probe.Error)
+	AbortMultipartUpload(bucket, key, uploadID string, signature *Signature) *probe.Error
+	CreateObjectPart(string, string, string, int, string, string, int64, io.Reader, *Signature) (string, *probe.Error)
+	CompleteMultipartUpload(bucket, key, uploadID string, data io.Reader, signature *Signature) (ObjectMetadata, *probe.Error)
+	ListMultipartUploads(string, BucketMultipartResourcesMetadata, *Signature) (BucketMultipartResourcesMetadata, *probe.Error)
+	ListObjectParts(string, string, ObjectResourcesMetadata, *Signature) (ObjectResourcesMetadata, *probe.Error)
 }
 
 // Management is a donut management system interface
 type Management interface {
-	Heal() error
-	Rebalance() error
-	Info() (map[string][]string, error)
+	Heal() *probe.Error
+	Rebalance() *probe.Error
+	Info() (map[string][]string, *probe.Error)
 
-	AttachNode(hostname string, disks []string) error
-	DetachNode(hostname string) error
+	AttachNode(hostname string, disks []string) *probe.Error
+	DetachNode(hostname string) *probe.Error
 }

pkg/donut/management.go

@@ -18,16 +18,16 @@ package donut
 
 import (
 	"github.com/minio/minio/pkg/donut/disk"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // Info - return info about donut configuration
-func (donut API) Info() (nodeDiskMap map[string][]string, err error) {
+func (donut API) Info() (nodeDiskMap map[string][]string, err *probe.Error) {
 	nodeDiskMap = make(map[string][]string)
 	for nodeName, node := range donut.nodes {
 		disks, err := node.ListDisks()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err.Trace()
 		}
 		diskList := make([]string, len(disks))
 		for diskOrder, disk := range disks {
@@ -39,13 +39,13 @@ func (donut API) Info() (nodeDiskMap map[string][]string, err error) {
 }
 
 // AttachNode - attach node
-func (donut API) AttachNode(hostname string, disks []string) error {
+func (donut API) AttachNode(hostname string, disks []string) *probe.Error {
 	if hostname == "" || len(disks) == 0 {
-		return iodine.New(InvalidArgument{}, nil)
+		return probe.New(InvalidArgument{})
 	}
 	node, err := newNode(hostname)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	donut.nodes[hostname] = node
 	for i, d := range disks {
@@ -54,28 +54,28 @@ func (donut API) AttachNode(hostname string, disks []string) error {
 			continue
 		}
 		if err := newDisk.MakeDir(donut.config.DonutName); err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		if err := node.AttachDisk(newDisk, i); err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 	}
 	return nil
 }
 
 // DetachNode - detach node
-func (donut API) DetachNode(hostname string) error {
+func (donut API) DetachNode(hostname string) *probe.Error {
 	delete(donut.nodes, hostname)
 	return nil
 }
 
 // Rebalance - rebalance an existing donut with new disks and nodes
-func (donut API) Rebalance() error {
-	return iodine.New(APINotImplemented{API: "management.Rebalance"}, nil)
+func (donut API) Rebalance() *probe.Error {
+	return probe.New(APINotImplemented{API: "management.Rebalance"})
 }
 
 // Heal - heal your donuts
-func (donut API) Heal() error {
+func (donut API) Heal() *probe.Error {
 	// TODO handle data heal
 	return donut.healBuckets()
 }

pkg/donut/multipart.go

@@ -34,41 +34,41 @@ import (
 
 	"github.com/minio/minio/pkg/crypto/sha256"
 	"github.com/minio/minio/pkg/donut/cache/data"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 /// V2 API functions
 
 // NewMultipartUpload - initiate a new multipart session
-func (donut API) NewMultipartUpload(bucket, key, contentType string, signature *Signature) (string, error) {
+func (donut API) NewMultipartUpload(bucket, key, contentType string, signature *Signature) (string, *probe.Error) {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if !IsValidBucket(bucket) {
-		return "", iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return "", probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
-		return "", iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return "", probe.New(ObjectNameInvalid{Object: key})
 	}
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return "", iodine.New(err, nil)
+			return "", err.Trace()
 		}
 		if !ok {
-			return "", iodine.New(SignatureDoesNotMatch{}, nil)
+			return "", probe.New(SignatureDoesNotMatch{})
 		}
 	}
 	if len(donut.config.NodeDiskMap) > 0 {
 		return donut.newMultipartUpload(bucket, key, contentType)
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return "", iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return "", probe.New(BucketNotFound{Bucket: bucket})
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	objectKey := bucket + "/" + key
 	if _, ok := storedBucket.objectMetadata[objectKey]; ok == true {
-		return "", iodine.New(ObjectExists{Object: key}, nil)
+		return "", probe.New(ObjectExists{Object: key})
 	}
 	id := []byte(strconv.Itoa(rand.Int()) + bucket + key + time.Now().UTC().String())
 	uploadIDSum := sha512.Sum512(id)
@@ -88,57 +88,57 @@ func (donut API) NewMultipartUpload(bucket, key, contentType string, signature *
 }
 
 // AbortMultipartUpload - abort an incomplete multipart session
-func (donut API) AbortMultipartUpload(bucket, key, uploadID string, signature *Signature) error {
+func (donut API) AbortMultipartUpload(bucket, key, uploadID string, signature *Signature) *probe.Error {
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
 
 	if !IsValidBucket(bucket) {
-		return iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
-		return iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return probe.New(ObjectNameInvalid{Object: key})
 	}
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return iodine.New(err, nil)
+			return err.Trace()
 		}
 		if !ok {
-			return iodine.New(SignatureDoesNotMatch{}, nil)
+			return probe.New(SignatureDoesNotMatch{})
 		}
 	}
 	if len(donut.config.NodeDiskMap) > 0 {
 		return donut.abortMultipartUpload(bucket, key, uploadID)
 	}
 	if !donut.storedBuckets.Exists(bucket) {
-		return iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return probe.New(BucketNotFound{Bucket: bucket})
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	if storedBucket.multiPartSession[key].UploadID != uploadID {
-		return iodine.New(InvalidUploadID{UploadID: uploadID}, nil)
+		return probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 	donut.cleanupMultipartSession(bucket, key, uploadID)
 	return nil
 }
 
 // CreateObjectPart - create a part in a multipart session
-func (donut API) CreateObjectPart(bucket, key, uploadID string, partID int, contentType, expectedMD5Sum string, size int64, data io.Reader, signature *Signature) (string, error) {
+func (donut API) CreateObjectPart(bucket, key, uploadID string, partID int, contentType, expectedMD5Sum string, size int64, data io.Reader, signature *Signature) (string, *probe.Error) {
 	donut.lock.Lock()
 	etag, err := donut.createObjectPart(bucket, key, uploadID, partID, "", expectedMD5Sum, size, data, signature)
 	donut.lock.Unlock()
 	// possible free
 	debug.FreeOSMemory()
 
-	return etag, iodine.New(err, nil)
+	return etag, err.Trace()
 }
 
 // createObject - internal wrapper function called by CreateObjectPart
-func (donut API) createObjectPart(bucket, key, uploadID string, partID int, contentType, expectedMD5Sum string, size int64, data io.Reader, signature *Signature) (string, error) {
+func (donut API) createObjectPart(bucket, key, uploadID string, partID int, contentType, expectedMD5Sum string, size int64, data io.Reader, signature *Signature) (string, *probe.Error) {
 	if !IsValidBucket(bucket) {
-		return "", iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return "", probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
-		return "", iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return "", probe.New(ObjectNameInvalid{Object: key})
 	}
 	if len(donut.config.NodeDiskMap) > 0 {
 		metadata := make(map[string]string)
@@ -151,24 +151,24 @@ func (donut API) createObjectPart(bucket, key, uploadID string, partID int, cont
 			expectedMD5SumBytes, err := base64.StdEncoding.DecodeString(strings.TrimSpace(expectedMD5Sum))
 			if err != nil {
 				// pro-actively close the connection
-				return "", iodine.New(InvalidDigest{Md5: expectedMD5Sum}, nil)
+				return "", probe.New(InvalidDigest{Md5: expectedMD5Sum})
 			}
 			expectedMD5Sum = hex.EncodeToString(expectedMD5SumBytes)
 		}
 		partMetadata, err := donut.putObjectPart(bucket, key, expectedMD5Sum, uploadID, partID, data, size, metadata, signature)
 		if err != nil {
-			return "", iodine.New(err, nil)
+			return "", err.Trace()
 		}
 		return partMetadata.ETag, nil
 	}
 
 	if !donut.storedBuckets.Exists(bucket) {
-		return "", iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return "", probe.New(BucketNotFound{Bucket: bucket})
 	}
 	strBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	// Verify upload id
 	if strBucket.multiPartSession[key].UploadID != uploadID {
-		return "", iodine.New(InvalidUploadID{UploadID: uploadID}, nil)
+		return "", probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 
 	// get object key
@@ -185,7 +185,7 @@ func (donut API) createObjectPart(bucket, key, uploadID string, partID int, cont
 		expectedMD5SumBytes, err := base64.StdEncoding.DecodeString(strings.TrimSpace(expectedMD5Sum))
 		if err != nil {
 			// pro-actively close the connection
-			return "", iodine.New(InvalidDigest{Md5: expectedMD5Sum}, nil)
+			return "", probe.New(InvalidDigest{Md5: expectedMD5Sum})
 		}
 		expectedMD5Sum = hex.EncodeToString(expectedMD5SumBytes)
 	}
@@ -194,27 +194,27 @@ func (donut API) createObjectPart(bucket, key, uploadID string, partID int, cont
 	hash := md5.New()
 	sha256hash := sha256.New()
 
-	var err error
 	var totalLength int64
+	var err error
 	for err == nil {
 		var length int
 		byteBuffer := make([]byte, 1024*1024)
-		length, err = data.Read(byteBuffer)
+		length, err = data.Read(byteBuffer) // do not read error return error here, we will handle this error later
 		hash.Write(byteBuffer[0:length])
 		sha256hash.Write(byteBuffer[0:length])
 		ok := donut.multiPartObjects[uploadID].Append(partID, byteBuffer[0:length])
 		if !ok {
-			return "", iodine.New(InternalError{}, nil)
+			return "", probe.New(InternalError{})
 		}
 		totalLength += int64(length)
 		go debug.FreeOSMemory()
 	}
 	if totalLength != size {
 		donut.multiPartObjects[uploadID].Delete(partID)
-		return "", iodine.New(IncompleteBody{Bucket: bucket, Object: key}, nil)
+		return "", probe.New(IncompleteBody{Bucket: bucket, Object: key})
 	}
 	if err != io.EOF {
-		return "", iodine.New(err, nil)
+		return "", probe.New(err)
 	}
 
 	md5SumBytes := hash.Sum(nil)
@@ -222,17 +222,19 @@ func (donut API) createObjectPart(bucket, key, uploadID string, partID int, cont
 	// Verify if the written object is equal to what is expected, only if it is requested as such
 	if strings.TrimSpace(expectedMD5Sum) != "" {
 		if err := isMD5SumEqual(strings.TrimSpace(expectedMD5Sum), md5Sum); err != nil {
-			return "", iodine.New(BadDigest{}, nil)
+			return "", err.Trace()
 		}
 	}
 
 	if signature != nil {
-		ok, err := signature.DoesSignatureMatch(hex.EncodeToString(sha256hash.Sum(nil)))
-		if err != nil {
-			return "", iodine.New(err, nil)
-		}
-		if !ok {
-			return "", iodine.New(SignatureDoesNotMatch{}, nil)
+		{
+			ok, err := signature.DoesSignatureMatch(hex.EncodeToString(sha256hash.Sum(nil)))
+			if err != nil {
+				return "", err.Trace()
+			}
+			if !ok {
+				return "", probe.New(SignatureDoesNotMatch{})
+			}
 		}
 	}
 
@@ -264,16 +266,16 @@ func (donut API) cleanupMultipartSession(bucket, key, uploadID string) {
 }
 
 // CompleteMultipartUpload - complete a multipart upload and persist the data
-func (donut API) CompleteMultipartUpload(bucket, key, uploadID string, data io.Reader, signature *Signature) (ObjectMetadata, error) {
+func (donut API) CompleteMultipartUpload(bucket, key, uploadID string, data io.Reader, signature *Signature) (ObjectMetadata, *probe.Error) {
 	donut.lock.Lock()
 
 	if !IsValidBucket(bucket) {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return ObjectMetadata{}, probe.New(ObjectNameInvalid{Object: key})
 	}
 	if len(donut.config.NodeDiskMap) > 0 {
 		donut.lock.Unlock()
@@ -282,38 +284,38 @@ func (donut API) CompleteMultipartUpload(bucket, key, uploadID string, data io.R
 
 	if !donut.storedBuckets.Exists(bucket) {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return ObjectMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	// Verify upload id
 	if storedBucket.multiPartSession[key].UploadID != uploadID {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(InvalidUploadID{UploadID: uploadID}, nil)
+		return ObjectMetadata{}, probe.New(InvalidUploadID{UploadID: uploadID})
 	}
 	partBytes, err := ioutil.ReadAll(data)
 	if err != nil {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(err, nil)
+		return ObjectMetadata{}, probe.New(err)
 	}
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch(hex.EncodeToString(sha256.Sum256(partBytes)[:]))
 		if err != nil {
 			donut.lock.Unlock()
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, err.Trace()
 		}
 		if !ok {
 			donut.lock.Unlock()
-			return ObjectMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return ObjectMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 	parts := &CompleteMultipartUpload{}
 	if err := xml.Unmarshal(partBytes, parts); err != nil {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(MalformedXML{}, nil)
+		return ObjectMetadata{}, probe.New(MalformedXML{})
 	}
 	if !sort.IsSorted(completedParts(parts.Part)) {
 		donut.lock.Unlock()
-		return ObjectMetadata{}, iodine.New(InvalidPartOrder{}, nil)
+		return ObjectMetadata{}, probe.New(InvalidPartOrder{})
 	}
 
 	var size int64
@@ -323,7 +325,7 @@ func (donut API) CompleteMultipartUpload(bucket, key, uploadID string, data io.R
 		object, ok := donut.multiPartObjects[uploadID].Get(parts.Part[i].PartNumber)
 		if ok == false {
 			donut.lock.Unlock()
-			return ObjectMetadata{}, iodine.New(InvalidPart{}, nil)
+			return ObjectMetadata{}, probe.New(InvalidPart{})
 		}
 		size += int64(len(object))
 		calcMD5Bytes := md5.Sum(object)
@@ -331,16 +333,15 @@ func (donut API) CompleteMultipartUpload(bucket, key, uploadID string, data io.R
 		recvMD5Bytes, err := hex.DecodeString(strings.Trim(recvMD5, "\""))
 		if err != nil {
 			donut.lock.Unlock()
-			return ObjectMetadata{}, iodine.New(InvalidDigest{Md5: recvMD5}, nil)
+			return ObjectMetadata{}, probe.New(InvalidDigest{Md5: recvMD5})
 		}
 		if !bytes.Equal(recvMD5Bytes, calcMD5Bytes[:]) {
 			donut.lock.Unlock()
-			return ObjectMetadata{}, iodine.New(BadDigest{}, nil)
+			return ObjectMetadata{}, probe.New(BadDigest{})
 		}
-		_, err = io.Copy(&fullObject, bytes.NewBuffer(object))
-		if err != nil {
+		if _, err := io.Copy(&fullObject, bytes.NewBuffer(object)); err != nil {
 			donut.lock.Unlock()
-			return ObjectMetadata{}, iodine.New(err, nil)
+			return ObjectMetadata{}, probe.New(err)
 		}
 		object = nil
 		go debug.FreeOSMemory()
@@ -350,18 +351,20 @@ func (donut API) CompleteMultipartUpload(bucket, key, uploadID string, data io.R
 	// this is needed for final verification inside CreateObject, do not convert this to hex
 	md5sum := base64.StdEncoding.EncodeToString(md5sumSlice[:])
 	donut.lock.Unlock()
-	objectMetadata, err := donut.CreateObject(bucket, key, md5sum, size, &fullObject, nil, nil)
-	if err != nil {
-		// No need to call internal cleanup functions here, caller will call AbortMultipartUpload()
-		// which would in-turn cleanup properly in accordance with S3 Spec
-		return ObjectMetadata{}, iodine.New(err, nil)
-	}
-	fullObject.Reset()
+	{
+		objectMetadata, err := donut.CreateObject(bucket, key, md5sum, size, &fullObject, nil, nil)
+		if err != nil {
+			// No need to call internal cleanup functions here, caller should call AbortMultipartUpload()
+			// which would in-turn cleanup properly in accordance with S3 Spec
+			return ObjectMetadata{}, err.Trace()
+		}
+		fullObject.Reset()
 
-	donut.lock.Lock()
-	donut.cleanupMultipartSession(bucket, key, uploadID)
-	donut.lock.Unlock()
-	return objectMetadata, nil
+		donut.lock.Lock()
+		donut.cleanupMultipartSession(bucket, key, uploadID)
+		donut.lock.Unlock()
+		return objectMetadata, nil
+	}
 }
 
 // byKey is a sortable interface for UploadMetadata slice
@@ -372,7 +375,7 @@ func (a byKey) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 func (a byKey) Less(i, j int) bool { return a[i].Key < a[j].Key }
 
 // ListMultipartUploads - list incomplete multipart sessions for a given bucket
-func (donut API) ListMultipartUploads(bucket string, resources BucketMultipartResourcesMetadata, signature *Signature) (BucketMultipartResourcesMetadata, error) {
+func (donut API) ListMultipartUploads(bucket string, resources BucketMultipartResourcesMetadata, signature *Signature) (BucketMultipartResourcesMetadata, *probe.Error) {
 	// TODO handle delimiter
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
@@ -380,15 +383,15 @@ func (donut API) ListMultipartUploads(bucket string, resources BucketMultipartRe
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return BucketMultipartResourcesMetadata{}, iodine.New(err, nil)
+			return BucketMultipartResourcesMetadata{}, err.Trace()
 		}
 		if !ok {
-			return BucketMultipartResourcesMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return BucketMultipartResourcesMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	if !IsValidBucket(bucket) {
-		return BucketMultipartResourcesMetadata{}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return BucketMultipartResourcesMetadata{}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 
 	if len(donut.config.NodeDiskMap) > 0 {
@@ -396,7 +399,7 @@ func (donut API) ListMultipartUploads(bucket string, resources BucketMultipartRe
 	}
 
 	if !donut.storedBuckets.Exists(bucket) {
-		return BucketMultipartResourcesMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return BucketMultipartResourcesMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
@@ -454,7 +457,7 @@ func (a partNumber) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 func (a partNumber) Less(i, j int) bool { return a[i].PartNumber < a[j].PartNumber }
 
 // ListObjectParts - list parts from incomplete multipart session for a given object
-func (donut API) ListObjectParts(bucket, key string, resources ObjectResourcesMetadata, signature *Signature) (ObjectResourcesMetadata, error) {
+func (donut API) ListObjectParts(bucket, key string, resources ObjectResourcesMetadata, signature *Signature) (ObjectResourcesMetadata, *probe.Error) {
 	// Verify upload id
 	donut.lock.Lock()
 	defer donut.lock.Unlock()
@@ -462,18 +465,18 @@ func (donut API) ListObjectParts(bucket, key string, resources ObjectResourcesMe
 	if signature != nil {
 		ok, err := signature.DoesSignatureMatch("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
-			return ObjectResourcesMetadata{}, iodine.New(err, nil)
+			return ObjectResourcesMetadata{}, err.Trace()
 		}
 		if !ok {
-			return ObjectResourcesMetadata{}, iodine.New(SignatureDoesNotMatch{}, nil)
+			return ObjectResourcesMetadata{}, probe.New(SignatureDoesNotMatch{})
 		}
 	}
 
 	if !IsValidBucket(bucket) {
-		return ObjectResourcesMetadata{}, iodine.New(BucketNameInvalid{Bucket: bucket}, nil)
+		return ObjectResourcesMetadata{}, probe.New(BucketNameInvalid{Bucket: bucket})
 	}
 	if !IsValidObjectName(key) {
-		return ObjectResourcesMetadata{}, iodine.New(ObjectNameInvalid{Object: key}, nil)
+		return ObjectResourcesMetadata{}, probe.New(ObjectNameInvalid{Object: key})
 	}
 
 	if len(donut.config.NodeDiskMap) > 0 {
@@ -481,14 +484,14 @@ func (donut API) ListObjectParts(bucket, key string, resources ObjectResourcesMe
 	}
 
 	if !donut.storedBuckets.Exists(bucket) {
-		return ObjectResourcesMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return ObjectResourcesMetadata{}, probe.New(BucketNotFound{Bucket: bucket})
 	}
 	storedBucket := donut.storedBuckets.Get(bucket).(storedBucket)
 	if _, ok := storedBucket.multiPartSession[key]; ok == false {
-		return ObjectResourcesMetadata{}, iodine.New(ObjectNotFound{Object: key}, nil)
+		return ObjectResourcesMetadata{}, probe.New(ObjectNotFound{Object: key})
 	}
 	if storedBucket.multiPartSession[key].UploadID != resources.UploadID {
-		return ObjectResourcesMetadata{}, iodine.New(InvalidUploadID{UploadID: resources.UploadID}, nil)
+		return ObjectResourcesMetadata{}, probe.New(InvalidUploadID{UploadID: resources.UploadID})
 	}
 	storedParts := storedBucket.partMetadata[key]
 	objectResourcesMetadata := resources
@@ -512,7 +515,7 @@ func (donut API) ListObjectParts(bucket, key string, resources ObjectResourcesMe
 		}
 		part, ok := storedParts[i]
 		if !ok {
-			return ObjectResourcesMetadata{}, iodine.New(InvalidPart{}, nil)
+			return ObjectResourcesMetadata{}, probe.New(InvalidPart{})
 		}
 		parts = append(parts, &part)
 	}

pkg/donut/node.go

@@ -18,7 +18,7 @@ package donut
 
 import (
 	"github.com/minio/minio/pkg/donut/disk"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // node struct internal
@@ -28,9 +28,9 @@ type node struct {
 }
 
 // newNode - instantiates a new node
-func newNode(hostname string) (node, error) {
+func newNode(hostname string) (node, *probe.Error) {
 	if hostname == "" {
-		return node{}, iodine.New(InvalidArgument{}, nil)
+		return node{}, probe.New(InvalidArgument{})
 	}
 	disks := make(map[int]disk.Disk)
 	n := node{
@@ -46,31 +46,31 @@ func (n node) GetHostname() string {
 }
 
 // ListDisks - return number of disks
-func (n node) ListDisks() (map[int]disk.Disk, error) {
+func (n node) ListDisks() (map[int]disk.Disk, *probe.Error) {
 	return n.disks, nil
 }
 
 // AttachDisk - attach a disk
-func (n node) AttachDisk(disk disk.Disk, diskOrder int) error {
+func (n node) AttachDisk(disk disk.Disk, diskOrder int) *probe.Error {
 	if diskOrder < 0 {
-		return iodine.New(InvalidArgument{}, nil)
+		return probe.New(InvalidArgument{})
 	}
 	n.disks[diskOrder] = disk
 	return nil
 }
 
 // DetachDisk - detach a disk
-func (n node) DetachDisk(diskOrder int) error {
+func (n node) DetachDisk(diskOrder int) *probe.Error {
 	delete(n.disks, diskOrder)
 	return nil
 }
 
 // SaveConfig - save node configuration
-func (n node) SaveConfig() error {
-	return iodine.New(NotImplemented{Function: "SaveConfig"}, nil)
+func (n node) SaveConfig() *probe.Error {
+	return probe.New(NotImplemented{Function: "SaveConfig"})
 }
 
 // LoadConfig - load node configuration from saved configs
-func (n node) LoadConfig() error {
-	return iodine.New(NotImplemented{Function: "LoadConfig"}, nil)
+func (n node) LoadConfig() *probe.Error {
+	return probe.New(NotImplemented{Function: "LoadConfig"})
 }

pkg/donut/signature-v4.go

@@ -28,7 +28,7 @@ import (
 	"unicode/utf8"
 
 	"github.com/minio/minio/pkg/crypto/sha256"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // Signature - local variables
@@ -59,7 +59,7 @@ func sumHMAC(key []byte, data []byte) []byte {
 //
 // This function on the other hand is a direct replacement for url.Encode() technique to support
 // pretty much every UTF-8 character.
-func urlEncodeName(name string) (string, error) {
+func urlEncodeName(name string) (string, *probe.Error) {
 	// if object matches reserved string, no need to encode them
 	reservedNames := regexp.MustCompile("^[a-zA-Z0-9-_.~/]+$")
 	if reservedNames.MatchString(name) {
@@ -78,7 +78,7 @@ func urlEncodeName(name string) (string, error) {
 		default:
 			len := utf8.RuneLen(s)
 			if len < 0 {
-				return "", iodine.New(InvalidArgument{}, nil)
+				return "", probe.New(InvalidArgument{})
 			}
 			u := make([]byte, len)
 			utf8.EncodeRune(u, s)
@@ -212,7 +212,7 @@ func (r *Signature) getSignature(signingKey []byte, stringToSign string) string
 
 // DoesSignatureMatch - Verify authorization header with calculated header in accordance with - http://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html
 // returns true if matches, false other wise if error is not nil then it is always false
-func (r *Signature) DoesSignatureMatch(hashedPayload string) (bool, error) {
+func (r *Signature) DoesSignatureMatch(hashedPayload string) (bool, *probe.Error) {
 	// set new calulated payload
 	r.Request.Header.Set("X-Amz-Content-Sha256", hashedPayload)
 
@@ -220,12 +220,12 @@ func (r *Signature) DoesSignatureMatch(hashedPayload string) (bool, error) {
 	var date string
 	if date = r.Request.Header.Get(http.CanonicalHeaderKey("x-amz-date")); date == "" {
 		if date = r.Request.Header.Get("Date"); date == "" {
-			return false, iodine.New(MissingDateHeader{}, nil)
+			return false, probe.New(MissingDateHeader{})
 		}
 	}
 	t, err := time.Parse(iso8601Format, date)
 	if err != nil {
-		return false, iodine.New(err, nil)
+		return false, probe.New(err)
 	}
 	canonicalRequest := r.getCanonicalRequest()
 	stringToSign := r.getStringToSign(canonicalRequest, t)

pkg/iodine/iodine.go

@@ -1,232 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2015 Minio, Inc.
- *
- * 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 iodine
-
-import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"os"
-	"path/filepath"
-	"reflect"
-	"runtime"
-	"strconv"
-	"strings"
-	"sync"
-
-	"github.com/dustin/go-humanize"
-)
-
-// Error is the iodine error which contains a pointer to the original error
-// and stack traces.
-type Error struct {
-	EmbeddedError error `json:"-"`
-	ErrorMessage  string
-	ErrorType     string
-
-	Stack []StackEntry
-}
-
-// StackEntry contains the entry in the stack trace
-type StackEntry struct {
-	Host string
-	File string
-	Func string
-	Line int
-	Data map[string]string
-}
-
-var gopathSource string
-
-var globalState = struct {
-	sync.RWMutex
-	m map[string]string
-}{m: make(map[string]string)}
-
-// SetGlobalState - set global state
-func SetGlobalState(key, value string) {
-	globalState.Lock()
-	globalState.m[key] = value
-	globalState.Unlock()
-}
-
-// ClearGlobalState - clear info in globalState struct
-func ClearGlobalState() {
-	globalState.Lock()
-	for k := range globalState.m {
-		delete(globalState.m, k)
-	}
-	globalState.Unlock()
-}
-
-// GetGlobalState - get map from globalState struct
-func GetGlobalState() map[string]string {
-	result := make(map[string]string)
-	globalState.RLock()
-	for k, v := range globalState.m {
-		result[k] = v
-	}
-	globalState.RUnlock()
-	return result
-}
-
-// GetGlobalStateKey - get value for key from globalState struct
-func GetGlobalStateKey(k string) string {
-	globalState.RLock()
-	result, _ := globalState.m[k]
-	globalState.RUnlock()
-	return result
-}
-
-// ToError returns the input if it is not an iodine error. It returns the embedded error if it is an iodine error. If nil, returns nil.
-func ToError(err error) error {
-	switch err := err.(type) {
-	case nil:
-		{
-			return nil
-		}
-	case Error:
-		{
-			if err.EmbeddedError != nil {
-				return err.EmbeddedError
-			}
-			return errors.New(err.ErrorMessage)
-		}
-	default:
-		{
-			return err
-		}
-	}
-}
-
-// New - instantiate an error, turning it into an iodine error.
-// Adds an initial stack trace.
-func New(err error, data map[string]string) error {
-	if err != nil {
-		entry := createStackEntry()
-		var newErr Error
-
-		// check if error is wrapped
-		switch typedError := err.(type) {
-		case Error:
-			{
-				newErr = typedError
-			}
-		default:
-			{
-				newErr = Error{
-					EmbeddedError: err,
-					ErrorMessage:  err.Error(),
-					ErrorType:     reflect.TypeOf(err).String(),
-					Stack:         []StackEntry{},
-				}
-			}
-		}
-		for k, v := range data {
-			entry.Data[k] = v
-		}
-		newErr.Stack = append(newErr.Stack, entry)
-		return newErr
-	}
-	return nil
-}
-
-// createStackEntry - create stack entries
-func createStackEntry() StackEntry {
-	host, _ := os.Hostname()
-	pc, file, line, _ := runtime.Caller(2)
-	function := runtime.FuncForPC(pc).Name()
-	_, function = filepath.Split(function)
-	file = strings.TrimPrefix(file, gopathSource) // trim gopathSource from file
-
-	data := GetGlobalState()
-	for k, v := range getSystemData() {
-		data[k] = v
-	}
-
-	entry := StackEntry{
-		Host: host,
-		File: file,
-		Func: function,
-		Line: line,
-		Data: data,
-	}
-	return entry
-}
-
-func getSystemData() map[string]string {
-	host, err := os.Hostname()
-	if err != nil {
-		host = ""
-	}
-	memstats := &runtime.MemStats{}
-	runtime.ReadMemStats(memstats)
-	return map[string]string{
-		"sys.host":               host,
-		"sys.os":                 runtime.GOOS,
-		"sys.arch":               runtime.GOARCH,
-		"sys.go":                 runtime.Version(),
-		"sys.cpus":               strconv.Itoa(runtime.NumCPU()),
-		"sys.mem.used":           humanize.Bytes(memstats.Alloc),
-		"sys.mem.allocated":      humanize.Bytes(memstats.TotalAlloc),
-		"sys.mem.heap.used":      humanize.Bytes(memstats.HeapAlloc),
-		"sys.mem.heap.allocated": humanize.Bytes(memstats.HeapSys),
-	}
-}
-
-// Annotate an error with a stack entry and returns itself
-//
-//  func (err *WrappedError) Annotate(info map[string]string) *WrappedError {
-//       entry := createStackEntry()
-//       for k, v := range info {
-// 		 entry.Data[k] = v
-//       }
-//       err.Stack = append(err.Stack, entry)
-//       return err
-//  }
-
-// EmitJSON writes JSON output for the error
-func (err Error) EmitJSON() ([]byte, error) {
-	return json.MarshalIndent(err, "", "\t")
-}
-
-// EmitHumanReadable returns a human readable error message
-func (err Error) EmitHumanReadable() string {
-	var errorBuffer bytes.Buffer
-	fmt.Fprintln(&errorBuffer, err.ErrorMessage)
-	for i, entry := range err.Stack {
-		prettyData, _ := json.Marshal(entry.Data)
-		fmt.Fprintln(&errorBuffer, "-", i, entry.Host+":"+entry.File+":"+strconv.Itoa(entry.Line)+" "+entry.Func+"():", string(prettyData))
-	}
-	return string(errorBuffer.Bytes())
-}
-
-// Emits the original error message
-func (err Error) Error() string {
-	return err.EmitHumanReadable()
-}
-
-func init() {
-	_, iodineFile, _, _ := runtime.Caller(0)
-	iodineFile = filepath.Dir(iodineFile)         // trim iodine.go
-	iodineFile = filepath.Dir(iodineFile)         // trim iodine
-	iodineFile = filepath.Dir(iodineFile)         // trim pkg
-	iodineFile = filepath.Dir(iodineFile)         // trim minio
-	iodineFile = filepath.Dir(iodineFile)         // trim minio
-	gopathSource = filepath.Dir(iodineFile) + "/" // trim github.com
-}

pkg/iodine/iodine_test.go

@@ -1,116 +0,0 @@
-/*
- * Iodine, (C) 2015 Minio, Inc.
- *
- * 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 iodine
-
-import (
-	"errors"
-	"fmt"
-	"testing"
-
-	"encoding/json"
-	"os"
-)
-
-func TestIodine(t *testing.T) {
-	iodineError := New(errors.New("Hello"), nil)
-	iodineError = New(iodineError, nil)
-	iodineError = New(iodineError, nil)
-	iodineError = New(iodineError, nil)
-
-	switch typedError := iodineError.(type) {
-	case Error:
-		{
-			// Visually watch out for formating errors
-			fmt.Println(typedError.EmitHumanReadable())
-
-			if len(typedError.Stack) != 4 {
-				t.Fail()
-			}
-			_, err := json.MarshalIndent(typedError, "", "  ")
-			if err != nil {
-				t.Fail()
-			}
-		}
-	default:
-		{
-			t.Fail()
-		}
-	}
-}
-
-func TestState(t *testing.T) {
-	SetGlobalState("hello", "world")
-	result := GetGlobalStateKey("hello")
-	if result != "world" {
-		t.Error("global state not set: hello->world")
-		t.Fail()
-	}
-	ClearGlobalState()
-	if len(GetGlobalState()) != 0 {
-		t.Fail()
-	}
-	SetGlobalState("foo", "bar")
-	err := New(errors.New("a simple error"), nil)
-	switch typedError := err.(type) {
-	case Error:
-		{
-			if res, ok := typedError.Stack[0].Data["foo"]; ok {
-				if res != "bar" {
-					t.Error("global state not set: foo->bar")
-				}
-			} else {
-				t.Fail()
-			}
-			typedError = New(typedError, map[string]string{"foo2": "bar2"}).(Error)
-			if res, ok := typedError.Stack[0].Data["foo"]; ok {
-				if res != "bar" {
-					t.Error("annotate should not modify previous data entries")
-				}
-			} else {
-				t.Error("annotate should not remove previous data entries")
-			}
-			if res, ok := typedError.Stack[1].Data["foo"]; ok {
-				if res != "bar" {
-					t.Error("global state should set value properly in annotate")
-				}
-			} else {
-				t.Error("global state should set key properly in annotate")
-			}
-			if res, ok := typedError.Stack[1].Data["foo2"]; ok {
-				if res != "bar2" {
-					//					typedError = Error(typedError, nil).(WrappedError)
-					t.Error("foo2 -> bar should be set")
-				}
-			} else {
-				//				typedError = Error(typedError, nil).(WrappedError)
-				t.Error("foo2 should be set")
-			}
-		}
-	}
-}
-
-func TestToError(t *testing.T) {
-	_, err := os.Stat("hello")
-	ierr := New(err, nil)
-	if ToError(ierr) != err {
-		t.Error("Error is not the same")
-	}
-	ierr = New(ierr, nil)
-	if ToError(ierr) != err {
-		t.Error("Stacked Error is not the same")
-	}
-}

pkg/probe/probe.go

@@ -71,6 +71,9 @@ type Error struct {
 // trace the return path with Probe.Trace and finally handle reporting or quitting
 // at the top level.
 func New(e error) *Error {
+	if e == nil {
+		return nil
+	}
 	Err := Error{sync.RWMutex{}, e, GetSysInfo(), []tracePoint{}}
 	return Err.trace()
 }

pkg/quick/quick.go

@@ -20,7 +20,6 @@ package quick
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -30,19 +29,18 @@ import (
 	"sync"
 
 	"github.com/fatih/structs"
-	"github.com/minio/minio/pkg/iodine"
-	"github.com/minio/minio/pkg/utils/atomic"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // Config - generic config interface functions
 type Config interface {
 	String() string
 	Version() string
-	Save(string) error
-	Load(string) error
+	Save(string) *probe.Error
+	Load(string) *probe.Error
 	Data() interface{}
-	Diff(Config) ([]structs.Field, error)
-	DeepDiff(Config) ([]structs.Field, error)
+	Diff(Config) ([]structs.Field, *probe.Error)
+	DeepDiff(Config) ([]structs.Field, *probe.Error)
 }
 
 // config - implements quick.Config interface
@@ -52,29 +50,29 @@ type config struct {
 }
 
 // CheckData - checks the validity of config data. Data sould be of type struct and contain a string type field called "Version"
-func CheckData(data interface{}) error {
+func CheckData(data interface{}) *probe.Error {
 	if !structs.IsStruct(data) {
-		return iodine.New(errors.New("Invalid argument type. Expecing \"struct\" type."), nil)
+		return probe.New(fmt.Errorf("Invalid argument type. Expecing \"struct\" type."))
 	}
 
 	st := structs.New(data)
 	f, ok := st.FieldOk("Version")
 	if !ok {
-		return iodine.New(fmt.Errorf("Invalid type of struct argument. No [%s.Version] field found.", st.Name()), nil)
+		return probe.New(fmt.Errorf("Invalid type of struct argument. No [%s.Version] field found.", st.Name()))
 	}
 
 	if f.Kind() != reflect.String {
-		return iodine.New(fmt.Errorf("Invalid type of struct argument. Expecting \"string\" type [%s.Version] field.", st.Name()), nil)
+		return probe.New(fmt.Errorf("Invalid type of struct argument. Expecting \"string\" type [%s.Version] field.", st.Name()))
 	}
 
 	return nil
 }
 
 // New - instantiate a new config
-func New(data interface{}) (Config, error) {
+func New(data interface{}) (Config, *probe.Error) {
 	err := CheckData(data)
 	if err != nil {
-		return nil, err
+		return nil, err.Trace()
 	}
 
 	d := new(config)
@@ -107,47 +105,40 @@ func (d config) String() string {
 }
 
 // Save writes config data in JSON format to a file.
-func (d config) Save(filename string) (err error) {
+func (d config) Save(filename string) *probe.Error {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
 	jsonData, err := json.MarshalIndent(d.data, "", "\t")
 	if err != nil {
-		return iodine.New(err, nil)
-	}
-
-	file, err := atomic.FileCreate(filename)
-	if err != nil {
-		return iodine.New(err, nil)
+		return probe.New(err)
 	}
 
 	if runtime.GOOS == "windows" {
 		jsonData = []byte(strings.Replace(string(jsonData), "\n", "\r\n", -1))
 	}
-	_, err = file.Write(jsonData)
+
+	err = ioutil.WriteFile(filename, jsonData, 0600)
 	if err != nil {
-		return iodine.New(err, nil)
+		return probe.New(err)
 	}
 
-	if err := file.Close(); err != nil {
-		return iodine.New(err, nil)
-	}
 	return nil
 }
 
 // Load - loads JSON config from file and merge with currently set values
-func (d *config) Load(filename string) (err error) {
+func (d *config) Load(filename string) *probe.Error {
 	(*d).lock.Lock()
 	defer (*d).lock.Unlock()
 
-	_, err = os.Stat(filename)
+	_, err := os.Stat(filename)
 	if err != nil {
-		return iodine.New(err, nil)
+		return probe.New(err)
 	}
 
 	fileData, err := ioutil.ReadFile(filename)
 	if err != nil {
-		return iodine.New(err, nil)
+		return probe.New(err)
 	}
 
 	if runtime.GOOS == "windows" {
@@ -156,22 +147,21 @@ func (d *config) Load(filename string) (err error) {
 
 	err = json.Unmarshal(fileData, (*d).data)
 	if err != nil {
-		return iodine.New(err, nil)
+		return probe.New(err)
 	}
 
-	err = CheckData(*(*d).data)
-	if err != nil {
-		return iodine.New(err, nil)
+	if err := CheckData(*(*d).data); err != nil {
+		return err.Trace()
 	}
 
 	st := structs.New(*(*d).data)
 	f, ok := st.FieldOk("Version")
 	if !ok {
-		return iodine.New(fmt.Errorf("Argument struct [%s] does not contain field \"Version\".", st.Name()), nil)
+		return probe.New(fmt.Errorf("Argument struct [%s] does not contain field \"Version\".", st.Name()))
 	}
 
 	if (*d).Version() != f.Value() {
-		return iodine.New(errors.New("Version mismatch"), nil)
+		return probe.New(fmt.Errorf("Version mismatch"))
 	}
 
 	return nil
@@ -183,10 +173,11 @@ func (d config) Data() interface{} {
 }
 
 //Diff  - list fields that are in A but not in B
-func (d config) Diff(c Config) (fields []structs.Field, err error) {
-	err = CheckData(c.Data())
+func (d config) Diff(c Config) ([]structs.Field, *probe.Error) {
+	var fields []structs.Field
+	err := CheckData(c.Data())
 	if err != nil {
-		return []structs.Field{}, iodine.New(err, nil)
+		return []structs.Field{}, err.Trace()
 	}
 
 	currFields := structs.Fields(d.Data())
@@ -208,10 +199,11 @@ func (d config) Diff(c Config) (fields []structs.Field, err error) {
 }
 
 //DeepDiff  - list fields in A that are missing or not equal to fields in B
-func (d config) DeepDiff(c Config) (fields []structs.Field, err error) {
-	err = CheckData(c.Data())
+func (d config) DeepDiff(c Config) ([]structs.Field, *probe.Error) {
+	var fields []structs.Field
+	err := CheckData(c.Data())
 	if err != nil {
-		return []structs.Field{}, iodine.New(err, nil)
+		return []structs.Field{}, err.Trace()
 	}
 
 	currFields := structs.Fields(d.Data())

pkg/server/api/bucket-handlers.go

@@ -21,7 +21,7 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/minio/minio/pkg/donut"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/utils/log"
 )
 
@@ -30,18 +30,7 @@ func (api Minio) isValidOp(w http.ResponseWriter, req *http.Request, acceptsCont
 	bucket := vars["bucket"]
 
 	bucketMetadata, err := api.Donut.GetBucketMetadata(bucket, nil)
-	switch iodine.ToError(err).(type) {
-	case donut.BucketNotFound:
-		{
-			writeErrorResponse(w, req, NoSuchBucket, acceptsContentType, req.URL.Path)
-			return false
-		}
-	case donut.BucketNameInvalid:
-		{
-			writeErrorResponse(w, req, InvalidBucketName, acceptsContentType, req.URL.Path)
-			return false
-		}
-	case nil:
+	if err == nil {
 		if _, err := StripAccessKeyID(req.Header.Get("Authorization")); err != nil {
 			if bucketMetadata.ACL.IsPrivate() {
 				return true
@@ -56,13 +45,20 @@ func (api Minio) isValidOp(w http.ResponseWriter, req *http.Request, acceptsCont
 				//return false
 			}
 		}
-	default:
-		{
-			log.Error.Println(iodine.New(err, nil))
-			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
-		}
+		return true
+	}
+	switch err.ToError().(type) {
+	case donut.BucketNotFound:
+		writeErrorResponse(w, req, NoSuchBucket, acceptsContentType, req.URL.Path)
+		return false
+	case donut.BucketNameInvalid:
+		writeErrorResponse(w, req, InvalidBucketName, acceptsContentType, req.URL.Path)
+		return false
+	default:
+		log.Error.Println(err.Trace())
+		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
+		return false
 	}
-	return true
 }
 
 // ListMultipartUploadsHandler - GET Bucket (List Multipart uploads)
@@ -102,7 +98,7 @@ func (api Minio) ListMultipartUploadsHandler(w http.ResponseWriter, req *http.Re
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -111,23 +107,23 @@ func (api Minio) ListMultipartUploadsHandler(w http.ResponseWriter, req *http.Re
 	}
 
 	resources, err := api.Donut.ListMultipartUploads(bucket, resources, signature)
-	switch iodine.ToError(err).(type) {
-	case nil: // success
-		{
-			// generate response
-			response := generateListMultipartUploadsResponse(bucket, resources)
-			encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
-			// write headers
-			setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
-			// write body
-			w.Write(encodedSuccessResponse)
-		}
+	if err == nil {
+		// generate response
+		response := generateListMultipartUploadsResponse(bucket, resources)
+		encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
+		// write headers
+		setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
+		// write body
+		w.Write(encodedSuccessResponse)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.BucketNotFound:
 		writeErrorResponse(w, req, NoSuchBucket, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -173,7 +169,7 @@ func (api Minio) ListObjectsHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -182,8 +178,7 @@ func (api Minio) ListObjectsHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	objects, resources, err := api.Donut.ListObjects(bucket, resources, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		// generate response
 		response := generateListObjectsResponse(bucket, objects, resources)
 		encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
@@ -191,6 +186,9 @@ func (api Minio) ListObjectsHandler(w http.ResponseWriter, req *http.Request) {
 		setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
 		// write body
 		w.Write(encodedSuccessResponse)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.BucketNameInvalid:
@@ -202,7 +200,7 @@ func (api Minio) ListObjectsHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.ObjectNameInvalid:
 		writeErrorResponse(w, req, NoSuchKey, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -232,7 +230,7 @@ func (api Minio) ListBucketsHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -241,8 +239,7 @@ func (api Minio) ListBucketsHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	buckets, err := api.Donut.ListBuckets(signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		// generate response
 		response := generateListBucketsResponse(buckets)
 		encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
@@ -250,10 +247,13 @@ func (api Minio) ListBucketsHandler(w http.ResponseWriter, req *http.Request) {
 		setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
 		// write response
 		w.Write(encodedSuccessResponse)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -296,7 +296,7 @@ func (api Minio) PutBucketHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -315,11 +315,13 @@ func (api Minio) PutBucketHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	err := api.Donut.MakeBucket(bucket, getACLTypeString(aclType), req.Body, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		// Make sure to add Location information here only for bucket
 		w.Header().Set("Location", "/"+bucket)
 		writeSuccessResponse(w, acceptsContentType)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.TooManyBuckets:
@@ -329,7 +331,7 @@ func (api Minio) PutBucketHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.BucketExists:
 		writeErrorResponse(w, req, BucketAlreadyExists, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -362,7 +364,7 @@ func (api Minio) PutBucketACLHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -371,9 +373,11 @@ func (api Minio) PutBucketACLHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	err := api.Donut.SetBucketMetadata(bucket, map[string]string{"acl": getACLTypeString(aclType)}, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		writeSuccessResponse(w, acceptsContentType)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.BucketNameInvalid:
@@ -381,7 +385,7 @@ func (api Minio) PutBucketACLHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.BucketNotFound:
 		writeErrorResponse(w, req, NoSuchBucket, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -410,7 +414,7 @@ func (api Minio) HeadBucketHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -419,9 +423,11 @@ func (api Minio) HeadBucketHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	_, err := api.Donut.GetBucketMetadata(bucket, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		writeSuccessResponse(w, acceptsContentType)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.BucketNotFound:
@@ -429,7 +435,7 @@ func (api Minio) HeadBucketHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.BucketNameInvalid:
 		writeErrorResponse(w, req, InvalidBucketName, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }

pkg/server/api/logging-handlers.go

@@ -24,7 +24,7 @@ import (
 	"os"
 	"time"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/utils/log"
 )
 
@@ -99,12 +99,12 @@ func fileLogger(filename string) (chan<- []byte, error) {
 	ch := make(chan []byte)
 	file, err := os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
 	if err != nil {
-		return nil, iodine.New(err, map[string]string{"logfile": filename})
+		return nil, probe.New(err)
 	}
 	go func() {
 		for message := range ch {
 			if _, err := io.Copy(file, bytes.NewBuffer(message)); err != nil {
-				log.Errorln(iodine.New(err, nil))
+				log.Errorln(probe.New(err))
 			}
 		}
 	}()

pkg/server/api/object-handlers.go

@@ -22,7 +22,7 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/minio/minio/pkg/donut"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/utils/log"
 )
 
@@ -57,7 +57,7 @@ func (api Minio) GetObjectHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -66,21 +66,21 @@ func (api Minio) GetObjectHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	metadata, err := api.Donut.GetObjectMetadata(bucket, object, signature)
-	switch iodine.ToError(err).(type) {
-	case nil: // success
-		{
-			httpRange, err := getRequestedRange(req.Header.Get("Range"), metadata.Size)
-			if err != nil {
-				writeErrorResponse(w, req, InvalidRange, acceptsContentType, req.URL.Path)
-				return
-			}
-			setObjectHeaders(w, metadata, httpRange)
-			if _, err := api.Donut.GetObject(w, bucket, object, httpRange.start, httpRange.length); err != nil {
-				// unable to write headers, we've already printed data. Just close the connection.
-				log.Error.Println(iodine.New(err, nil))
-				return
-			}
+	if err == nil {
+		httpRange, err := getRequestedRange(req.Header.Get("Range"), metadata.Size)
+		if err != nil {
+			writeErrorResponse(w, req, InvalidRange, acceptsContentType, req.URL.Path)
+			return
 		}
+		setObjectHeaders(w, metadata, httpRange)
+		if _, err := api.Donut.GetObject(w, bucket, object, httpRange.start, httpRange.length); err != nil {
+			// unable to write headers, we've already printed data. Just close the connection.
+			log.Error.Println(err.Trace())
+			return
+		}
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.BucketNameInvalid:
@@ -92,7 +92,7 @@ func (api Minio) GetObjectHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.ObjectNameInvalid:
 		writeErrorResponse(w, req, NoSuchKey, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -123,7 +123,7 @@ func (api Minio) HeadObjectHandler(w http.ResponseWriter, req *http.Request) {
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -132,10 +132,12 @@ func (api Minio) HeadObjectHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	metadata, err := api.Donut.GetObjectMetadata(bucket, object, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		setObjectHeaders(w, metadata, nil)
 		w.WriteHeader(http.StatusOK)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.BucketNameInvalid:
@@ -147,7 +149,7 @@ func (api Minio) HeadObjectHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.ObjectNameInvalid:
 		writeErrorResponse(w, req, NoSuchKey, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -202,16 +204,20 @@ func (api Minio) PutObjectHandler(w http.ResponseWriter, req *http.Request) {
 	//      writeErrorResponse(w, req, EntityTooSmall, acceptsContentType, req.URL.Path)
 	//	return
 	// }
-	sizeInt64, err := strconv.ParseInt(size, 10, 64)
-	if err != nil {
-		writeErrorResponse(w, req, InvalidRequest, acceptsContentType, req.URL.Path)
-		return
+	var sizeInt64 int64
+	{
+		var err error
+		sizeInt64, err = strconv.ParseInt(size, 10, 64)
+		if err != nil {
+			writeErrorResponse(w, req, InvalidRequest, acceptsContentType, req.URL.Path)
+			return
+		}
 	}
 
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -220,10 +226,12 @@ func (api Minio) PutObjectHandler(w http.ResponseWriter, req *http.Request) {
 	}
 
 	metadata, err := api.Donut.CreateObject(bucket, object, md5, sizeInt64, req.Body, nil, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		w.Header().Set("ETag", metadata.MD5Sum)
 		writeSuccessResponse(w, acceptsContentType)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.BucketNotFound:
 		writeErrorResponse(w, req, NoSuchBucket, acceptsContentType, req.URL.Path)
 	case donut.BucketNameInvalid:
@@ -243,7 +251,7 @@ func (api Minio) PutObjectHandler(w http.ResponseWriter, req *http.Request) {
 	case donut.InvalidDigest:
 		writeErrorResponse(w, req, InvalidDigest, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -279,7 +287,7 @@ func (api Minio) NewMultipartUploadHandler(w http.ResponseWriter, req *http.Requ
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -288,22 +296,22 @@ func (api Minio) NewMultipartUploadHandler(w http.ResponseWriter, req *http.Requ
 	}
 
 	uploadID, err := api.Donut.NewMultipartUpload(bucket, object, req.Header.Get("Content-Type"), signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
-		{
-			response := generateInitiateMultipartUploadResponse(bucket, object, uploadID)
-			encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
-			// write headers
-			setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
-			// write body
-			w.Write(encodedSuccessResponse)
-		}
+	if err == nil {
+		response := generateInitiateMultipartUploadResponse(bucket, object, uploadID)
+		encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
+		// write headers
+		setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
+		// write body
+		w.Write(encodedSuccessResponse)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.ObjectExists:
 		writeErrorResponse(w, req, MethodNotAllowed, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -344,10 +352,14 @@ func (api Minio) PutObjectPartHandler(w http.ResponseWriter, req *http.Request)
 		return
 	}
 
-	sizeInt64, err := strconv.ParseInt(size, 10, 64)
-	if err != nil {
-		writeErrorResponse(w, req, InvalidRequest, acceptsContentType, req.URL.Path)
-		return
+	var sizeInt64 int64
+	{
+		var err error
+		sizeInt64, err = strconv.ParseInt(size, 10, 64)
+		if err != nil {
+			writeErrorResponse(w, req, InvalidRequest, acceptsContentType, req.URL.Path)
+			return
+		}
 	}
 
 	vars := mux.Vars(req)
@@ -357,15 +369,19 @@ func (api Minio) PutObjectPartHandler(w http.ResponseWriter, req *http.Request)
 	uploadID := req.URL.Query().Get("uploadId")
 	partIDString := req.URL.Query().Get("partNumber")
 
-	partID, err := strconv.Atoi(partIDString)
-	if err != nil {
-		writeErrorResponse(w, req, InvalidPart, acceptsContentType, req.URL.Path)
+	var partID int
+	{
+		var err error
+		partID, err = strconv.Atoi(partIDString)
+		if err != nil {
+			writeErrorResponse(w, req, InvalidPart, acceptsContentType, req.URL.Path)
+		}
 	}
 
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -374,10 +390,12 @@ func (api Minio) PutObjectPartHandler(w http.ResponseWriter, req *http.Request)
 	}
 
 	calculatedMD5, err := api.Donut.CreateObjectPart(bucket, object, uploadID, partID, "", md5, sizeInt64, req.Body, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		w.Header().Set("ETag", calculatedMD5)
 		writeSuccessResponse(w, acceptsContentType)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.InvalidUploadID:
 		writeErrorResponse(w, req, NoSuchUpload, acceptsContentType, req.URL.Path)
 	case donut.ObjectExists:
@@ -393,7 +411,7 @@ func (api Minio) PutObjectPartHandler(w http.ResponseWriter, req *http.Request)
 	case donut.InvalidDigest:
 		writeErrorResponse(w, req, InvalidDigest, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -423,7 +441,7 @@ func (api Minio) AbortMultipartUploadHandler(w http.ResponseWriter, req *http.Re
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -432,16 +450,18 @@ func (api Minio) AbortMultipartUploadHandler(w http.ResponseWriter, req *http.Re
 	}
 
 	err := api.Donut.AbortMultipartUpload(bucket, object, objectResourcesMetadata.UploadID, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
+	if err == nil {
 		setCommonHeaders(w, getContentTypeString(acceptsContentType), 0)
 		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.InvalidUploadID:
 		writeErrorResponse(w, req, NoSuchUpload, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -482,7 +502,7 @@ func (api Minio) ListObjectPartsHandler(w http.ResponseWriter, req *http.Request
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -491,22 +511,22 @@ func (api Minio) ListObjectPartsHandler(w http.ResponseWriter, req *http.Request
 	}
 
 	objectResourcesMetadata, err := api.Donut.ListObjectParts(bucket, object, objectResourcesMetadata, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
-		{
-			response := generateListPartsResponse(objectResourcesMetadata)
-			encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
-			// write headers
-			setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
-			// write body
-			w.Write(encodedSuccessResponse)
-		}
+	if err == nil {
+		response := generateListPartsResponse(objectResourcesMetadata)
+		encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
+		// write headers
+		setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
+		// write body
+		w.Write(encodedSuccessResponse)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.SignatureDoesNotMatch:
 		writeErrorResponse(w, req, SignatureDoesNotMatch, acceptsContentType, req.URL.Path)
 	case donut.InvalidUploadID:
 		writeErrorResponse(w, req, NoSuchUpload, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }
@@ -536,7 +556,7 @@ func (api Minio) CompleteMultipartUploadHandler(w http.ResponseWriter, req *http
 	var signature *donut.Signature
 	if _, ok := req.Header["Authorization"]; ok {
 		// Init signature V4 verification
-		var err error
+		var err *probe.Error
 		signature, err = InitSignatureV4(req)
 		if err != nil {
 			writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
@@ -544,16 +564,16 @@ func (api Minio) CompleteMultipartUploadHandler(w http.ResponseWriter, req *http
 		}
 	}
 	metadata, err := api.Donut.CompleteMultipartUpload(bucket, object, objectResourcesMetadata.UploadID, req.Body, signature)
-	switch iodine.ToError(err).(type) {
-	case nil:
-		{
-			response := generateCompleteMultpartUploadResponse(bucket, object, "", metadata.MD5Sum)
-			encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
-			// write headers
-			setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
-			// write body
-			w.Write(encodedSuccessResponse)
-		}
+	if err == nil {
+		response := generateCompleteMultpartUploadResponse(bucket, object, "", metadata.MD5Sum)
+		encodedSuccessResponse := encodeSuccessResponse(response, acceptsContentType)
+		// write headers
+		setCommonHeaders(w, getContentTypeString(acceptsContentType), len(encodedSuccessResponse))
+		// write body
+		w.Write(encodedSuccessResponse)
+		return
+	}
+	switch err.ToError().(type) {
 	case donut.InvalidUploadID:
 		writeErrorResponse(w, req, NoSuchUpload, acceptsContentType, req.URL.Path)
 	case donut.InvalidPart:
@@ -569,7 +589,7 @@ func (api Minio) CompleteMultipartUploadHandler(w http.ResponseWriter, req *http
 	case donut.MalformedXML:
 		writeErrorResponse(w, req, MalformedXML, acceptsContentType, req.URL.Path)
 	default:
-		log.Error.Println(iodine.New(err, nil))
+		log.Error.Println(err.Trace())
 		writeErrorResponse(w, req, InternalError, acceptsContentType, req.URL.Path)
 	}
 }

pkg/server/api/range.go

@@ -23,7 +23,7 @@ import (
 	"strings"
 
 	"github.com/minio/minio/pkg/donut"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 const (
@@ -51,7 +51,7 @@ func getRequestedRange(hrange string, size int64) (*httpRange, error) {
 	if hrange != "" {
 		err := r.parseRange(hrange)
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 	}
 	return r, nil
@@ -60,7 +60,7 @@ func getRequestedRange(hrange string, size int64) (*httpRange, error) {
 func (r *httpRange) parse(ra string) error {
 	i := strings.Index(ra, "-")
 	if i < 0 {
-		return iodine.New(donut.InvalidRange{}, nil)
+		return probe.New(donut.InvalidRange{})
 	}
 	start, end := strings.TrimSpace(ra[:i]), strings.TrimSpace(ra[i+1:])
 	if start == "" {
@@ -68,7 +68,7 @@ func (r *httpRange) parse(ra string) error {
 		// range start relative to the end of the file.
 		i, err := strconv.ParseInt(end, 10, 64)
 		if err != nil {
-			return iodine.New(donut.InvalidRange{}, nil)
+			return probe.New(donut.InvalidRange{})
 		}
 		if i > r.size {
 			i = r.size
@@ -78,7 +78,7 @@ func (r *httpRange) parse(ra string) error {
 	} else {
 		i, err := strconv.ParseInt(start, 10, 64)
 		if err != nil || i > r.size || i < 0 {
-			return iodine.New(donut.InvalidRange{}, nil)
+			return probe.New(donut.InvalidRange{})
 		}
 		r.start = i
 		if end == "" {
@@ -87,7 +87,7 @@ func (r *httpRange) parse(ra string) error {
 		} else {
 			i, err := strconv.ParseInt(end, 10, 64)
 			if err != nil || r.start > i {
-				return iodine.New(donut.InvalidRange{}, nil)
+				return probe.New(donut.InvalidRange{})
 			}
 			if i >= r.size {
 				i = r.size - 1
@@ -101,24 +101,24 @@ func (r *httpRange) parse(ra string) error {
 // parseRange parses a Range header string as per RFC 2616.
 func (r *httpRange) parseRange(s string) error {
 	if s == "" {
-		return iodine.New(errors.New("header not present"), nil)
+		return probe.New(errors.New("header not present"))
 	}
 	if !strings.HasPrefix(s, b) {
-		return iodine.New(donut.InvalidRange{}, nil)
+		return probe.New(donut.InvalidRange{})
 	}
 
 	ras := strings.Split(s[len(b):], ",")
 	if len(ras) == 0 {
-		return iodine.New(errors.New("invalid request"), nil)
+		return probe.New(errors.New("invalid request"))
 	}
 	// Just pick the first one and ignore the rest, we only support one range per object
 	if len(ras) > 1 {
-		return iodine.New(errors.New("multiple ranges specified"), nil)
+		return probe.New(errors.New("multiple ranges specified"))
 	}
 
 	ra := strings.TrimSpace(ras[0])
 	if ra == "" {
-		return iodine.New(donut.InvalidRange{}, nil)
+		return probe.New(donut.InvalidRange{})
 	}
 	return r.parse(ra)
 }

pkg/server/api/signature.go

@@ -23,7 +23,7 @@ import (
 
 	"github.com/minio/minio/pkg/auth"
 	"github.com/minio/minio/pkg/donut"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 const (
@@ -64,16 +64,23 @@ func StripAccessKeyID(ah string) (string, error) {
 }
 
 // InitSignatureV4 initializing signature verification
-func InitSignatureV4(req *http.Request) (*donut.Signature, error) {
+func InitSignatureV4(req *http.Request) (*donut.Signature, *probe.Error) {
 	// strip auth from authorization header
 	ah := req.Header.Get("Authorization")
-	accessKeyID, err := StripAccessKeyID(ah)
-	if err != nil {
-		return nil, iodine.New(err, nil)
+	var accessKeyID string
+	{
+		var err error
+		accessKeyID, err = StripAccessKeyID(ah)
+		if err != nil {
+			return nil, probe.New(err)
+		}
 	}
 	authConfig, err := auth.LoadConfig()
+	if err != nil {
+		return nil, err.Trace()
+	}
 	if _, ok := authConfig.Users[accessKeyID]; !ok {
-		return nil, errors.New("Access ID not found")
+		return nil, probe.New(errors.New("AccessID not found"))
 	}
 	signature := &donut.Signature{
 		AccessKeyID:     authConfig.Users[accessKeyID].AccessKeyID,

pkg/server/minhttp/http.go

@@ -32,7 +32,7 @@ import (
 	"time"
 
 	"github.com/facebookgo/httpdown"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // An app contains one or more servers and their associated configuration.
@@ -45,11 +45,11 @@ type app struct {
 }
 
 // listen initailize listeners
-func (a *app) listen() error {
+func (a *app) listen() *probe.Error {
 	for _, s := range a.servers {
 		l, err := a.net.Listen("tcp", s.Addr)
 		if err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 		if s.TLSConfig != nil {
 			l = tls.NewListener(l, s.TLSConfig)
@@ -79,7 +79,7 @@ func (a *app) wait() {
 		go func(s httpdown.Server) {
 			defer wg.Done()
 			if err := s.Wait(); err != nil {
-				a.errors <- iodine.New(err, nil)
+				a.errors <- probe.New(err)
 			}
 		}(s)
 	}
@@ -101,7 +101,7 @@ func (a *app) trapSignal(wg *sync.WaitGroup) {
 				go func(s httpdown.Server) {
 					defer wg.Done()
 					if err := s.Stop(); err != nil {
-						a.errors <- iodine.New(err, nil)
+						a.errors <- probe.New(err)
 					}
 				}(s)
 			}
@@ -112,7 +112,7 @@ func (a *app) trapSignal(wg *sync.WaitGroup) {
 			// we only return here if there's an error, otherwise the new process
 			// will send us a TERM when it's ready to trigger the actual shutdown.
 			if _, err := a.net.StartProcess(); err != nil {
-				a.errors <- iodine.New(err, nil)
+				a.errors <- probe.New(err)
 			}
 		}
 	}
@@ -120,7 +120,7 @@ func (a *app) trapSignal(wg *sync.WaitGroup) {
 
 // ListenAndServe will serve the given http.Servers and will monitor for signals
 // allowing for graceful termination (SIGTERM) or restart (SIGUSR2/SIGHUP).
-func ListenAndServe(servers ...*http.Server) error {
+func ListenAndServe(servers ...*http.Server) *probe.Error {
 	// get parent process id
 	ppid := os.Getppid()
 
@@ -134,7 +134,7 @@ func ListenAndServe(servers ...*http.Server) error {
 
 	// Acquire Listeners
 	if err := a.listen(); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 
 	// Start serving.
@@ -143,7 +143,7 @@ func ListenAndServe(servers ...*http.Server) error {
 	// Close the parent if we inherited and it wasn't init that started us.
 	if os.Getenv("LISTEN_FDS") != "" && ppid != 1 {
 		if err := syscall.Kill(ppid, syscall.SIGTERM); err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 	}
 
@@ -160,14 +160,14 @@ func ListenAndServe(servers ...*http.Server) error {
 		if err == nil {
 			panic("unexpected nil error")
 		}
-		return iodine.New(err, nil)
+		return probe.New(err)
 	case <-waitdone:
 		return nil
 	}
 }
 
 // ListenAndServeLimited is similar to ListenAndServe but ratelimited with connLimit value
-func ListenAndServeLimited(connLimit int, servers ...*http.Server) error {
+func ListenAndServeLimited(connLimit int, servers ...*http.Server) *probe.Error {
 	// get parent process id
 	ppid := os.Getppid()
 
@@ -181,7 +181,7 @@ func ListenAndServeLimited(connLimit int, servers ...*http.Server) error {
 
 	// Acquire Listeners
 	if err := a.listen(); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 
 	// Start serving.
@@ -190,7 +190,7 @@ func ListenAndServeLimited(connLimit int, servers ...*http.Server) error {
 	// Close the parent if we inherited and it wasn't init that started us.
 	if os.Getenv("LISTEN_FDS") != "" && ppid != 1 {
 		if err := syscall.Kill(ppid, syscall.SIGTERM); err != nil {
-			return iodine.New(err, nil)
+			return probe.New(err)
 		}
 	}
 
@@ -207,7 +207,7 @@ func ListenAndServeLimited(connLimit int, servers ...*http.Server) error {
 		if err == nil {
 			panic("unexpected nil error")
 		}
-		return iodine.New(err, nil)
+		return probe.New(err)
 	case <-waitdone:
 		return nil
 	}

pkg/server/minhttp/listen.go

@@ -20,8 +20,6 @@ import (
 	"net"
 	"os"
 	"sync"
-
-	"github.com/minio/minio/pkg/iodine"
 )
 
 // rateLimitedListener returns a Listener that accepts at most n simultaneous
@@ -53,7 +51,7 @@ func (l *rateLimitListener) Accept() (net.Conn, error) {
 	c, err := l.Listener.Accept()
 	if err != nil {
 		l.release()
-		return nil, iodine.New(err, nil)
+		return nil, err
 	}
 	return &rateLimitListenerConn{Conn: c, release: l.release}, nil
 }
@@ -67,5 +65,5 @@ type rateLimitListenerConn struct {
 func (l *rateLimitListenerConn) Close() error {
 	err := l.Conn.Close()
 	l.releaseOnce.Do(l.release)
-	return iodine.New(err, nil)
+	return err
 }

pkg/server/minhttp/net.go

@@ -25,7 +25,7 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // This package is a fork https://github.com/facebookgo/grace
@@ -71,8 +71,8 @@ type fileListener interface {
 }
 
 // getInheritedListeners - look for LISTEN_FDS in environment variables and populate listeners accordingly
-func (n *minNet) getInheritedListeners() error {
-	var retErr error
+func (n *minNet) getInheritedListeners() *probe.Error {
+	var retErr *probe.Error
 	n.inheritOnce.Do(func() {
 		n.mutex.Lock()
 		defer n.mutex.Unlock()
@@ -82,7 +82,7 @@ func (n *minNet) getInheritedListeners() error {
 		}
 		count, err := strconv.Atoi(countStr)
 		if err != nil {
-			retErr = fmt.Errorf("found invalid count value: %s=%s", envCountKey, countStr)
+			retErr = probe.New(fmt.Errorf("found invalid count value: %s=%s", envCountKey, countStr))
 			return
 		}
 
@@ -92,37 +92,40 @@ func (n *minNet) getInheritedListeners() error {
 			l, err := net.FileListener(file)
 			if err != nil {
 				file.Close()
-				retErr = iodine.New(fmt.Errorf("error inheriting socket fd %d: %s", i, err), nil)
+				retErr = probe.New(err)
 				return
 			}
 			if err := file.Close(); err != nil {
-				retErr = iodine.New(fmt.Errorf("error closing inherited socket fd %d: %s", i, err), nil)
+				retErr = probe.New(err)
 				return
 			}
 			n.inheritedListeners = append(n.inheritedListeners, l)
 		}
 	})
-	return iodine.New(retErr, nil)
+	if retErr != nil {
+		return probe.New(retErr)
+	}
+	return nil
 }
 
 // Listen announces on the local network address laddr. The network net must be
 // a stream-oriented network: "tcp", "tcp4", "tcp6", "unix" or "unixpacket". It
 // returns an inherited net.Listener for the matching network and address, or
 // creates a new one using net.Listen()
-func (n *minNet) Listen(nett, laddr string) (net.Listener, error) {
+func (n *minNet) Listen(nett, laddr string) (net.Listener, *probe.Error) {
 	switch nett {
 	default:
-		return nil, net.UnknownNetworkError(nett)
+		return nil, probe.New(net.UnknownNetworkError(nett))
 	case "tcp", "tcp4", "tcp6":
 		addr, err := net.ResolveTCPAddr(nett, laddr)
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 		return n.ListenTCP(nett, addr)
 	case "unix", "unixpacket":
 		addr, err := net.ResolveUnixAddr(nett, laddr)
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 		return n.ListenUnix(nett, addr)
 	}
@@ -131,10 +134,9 @@ func (n *minNet) Listen(nett, laddr string) (net.Listener, error) {
 // ListenTCP announces on the local network address laddr. The network net must
 // be: "tcp", "tcp4" or "tcp6". It returns an inherited net.Listener for the
 // matching network and address, or creates a new one using net.ListenTCP.
-func (n *minNet) ListenTCP(nett string, laddr *net.TCPAddr) (net.Listener, error) {
-	var err error
+func (n *minNet) ListenTCP(nett string, laddr *net.TCPAddr) (net.Listener, *probe.Error) {
 	if err := n.getInheritedListeners(); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 
 	n.mutex.Lock()
@@ -153,11 +155,10 @@ func (n *minNet) ListenTCP(nett string, laddr *net.TCPAddr) (net.Listener, error
 		}
 	}
 
-	var l net.Listener
 	// make a fresh listener
-	l, err = net.ListenTCP(nett, laddr)
+	l, err := net.ListenTCP(nett, laddr)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	n.activeListeners = append(n.activeListeners, rateLimitedListener(l, n.connLimit))
 	return l, nil
@@ -166,10 +167,9 @@ func (n *minNet) ListenTCP(nett string, laddr *net.TCPAddr) (net.Listener, error
 // ListenUnix announces on the local network address laddr. The network net
 // must be a: "unix" or "unixpacket". It returns an inherited net.Listener for
 // the matching network and address, or creates a new one using net.ListenUnix.
-func (n *minNet) ListenUnix(nett string, laddr *net.UnixAddr) (net.Listener, error) {
-	var err error
+func (n *minNet) ListenUnix(nett string, laddr *net.UnixAddr) (net.Listener, *probe.Error) {
 	if err := n.getInheritedListeners(); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err.Trace()
 	}
 
 	n.mutex.Lock()
@@ -188,23 +188,22 @@ func (n *minNet) ListenUnix(nett string, laddr *net.UnixAddr) (net.Listener, err
 		}
 	}
 
-	var l net.Listener
 	// make a fresh listener
-	l, err = net.ListenUnix(nett, laddr)
+	l, err := net.ListenUnix(nett, laddr)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 	n.activeListeners = append(n.activeListeners, rateLimitedListener(l, n.connLimit))
 	return l, nil
 }
 
 // activeListeners returns a snapshot copy of the active listeners.
-func (n *minNet) getActiveListeners() ([]net.Listener, error) {
+func (n *minNet) getActiveListeners() []net.Listener {
 	n.mutex.Lock()
 	defer n.mutex.Unlock()
 	ls := make([]net.Listener, len(n.activeListeners))
 	copy(ls, n.activeListeners)
-	return ls, nil
+	return ls
 }
 
 // IsEqual is synonymous with IP.IsEqual() method, here IsEqual matches net.Addr instead of net.IP
@@ -233,18 +232,15 @@ func (n1 minAddr) IsEqual(n2 net.Addr) bool {
 // arguments as when it was originally started. This allows for a newly
 // deployed binary to be started. It returns the pid of the newly started
 // process when successful.
-func (n *minNet) StartProcess() (int, error) {
-	listeners, err := n.getActiveListeners()
-	if err != nil {
-		return 0, iodine.New(err, nil)
-	}
-
+func (n *minNet) StartProcess() (int, *probe.Error) {
+	listeners := n.getActiveListeners()
 	// Extract the fds from the listeners.
 	files := make([]*os.File, len(listeners))
 	for i, l := range listeners {
+		var err error
 		files[i], err = l.(fileListener).File()
 		if err != nil {
-			return 0, iodine.New(err, nil)
+			return 0, probe.New(err)
 		}
 		defer files[i].Close()
 	}
@@ -253,7 +249,7 @@ func (n *minNet) StartProcess() (int, error) {
 	// the file it points to has been changed we will use the updated symlink.
 	argv0, err := exec.LookPath(os.Args[0])
 	if err != nil {
-		return 0, iodine.New(err, nil)
+		return 0, probe.New(err)
 	}
 
 	// Pass on the environment and replace the old count key with the new one.
@@ -272,7 +268,7 @@ func (n *minNet) StartProcess() (int, error) {
 		Files: allFiles,
 	})
 	if err != nil {
-		return 0, iodine.New(err, nil)
+		return 0, probe.New(err)
 	}
 	return process.Pid, nil
 }

pkg/server/minhttp/net_test.go

@@ -1,78 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2015 Minio, Inc.
- *
- * 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 minhttp
-
-import (
-	"os"
-	"regexp"
-	"testing"
-
-	"github.com/minio/minio/pkg/iodine"
-	. "gopkg.in/check.v1"
-)
-
-func Test(t *testing.T) { TestingT(t) }
-
-type MySuite struct{}
-
-var _ = Suite(&MySuite{})
-
-func (s *MySuite) TestEmptyCountEnvVariable(c *C) {
-	os.Setenv(envCountKey, "")
-	n := &minNet{}
-	c.Assert(n.getInheritedListeners(), IsNil)
-}
-
-func (s *MySuite) TestZeroCountEnvVariable(c *C) {
-	os.Setenv(envCountKey, "0")
-	n := &minNet{}
-	c.Assert(n.getInheritedListeners(), IsNil)
-}
-
-func (s *MySuite) TestInvalidCountEnvVariable(c *C) {
-	os.Setenv(envCountKey, "a")
-	n := &minNet{}
-	expected := regexp.MustCompile("^found invalid count value: LISTEN_FDS=a$")
-	err := n.getInheritedListeners()
-	c.Assert(err, Not(IsNil))
-	c.Assert(expected.MatchString(iodine.ToError(err).Error()), Equals, true)
-}
-
-func (s *MySuite) TestInheritErrorOnListenTCPWithInvalidCount(c *C) {
-	os.Setenv(envCountKey, "a")
-	n := &minNet{}
-	expected := regexp.MustCompile("^found invalid count value: LISTEN_FDS=a$")
-	_, err := n.Listen("tcp", ":0")
-	c.Assert(err, Not(IsNil))
-	c.Assert(expected.MatchString(iodine.ToError(err).Error()), Equals, true)
-}
-
-func (s *MySuite) TestInvalidNetwork(c *C) {
-	os.Setenv(envCountKey, "")
-	n := &minNet{}
-	_, err := n.Listen("foo", "")
-	c.Assert(err, Not(IsNil))
-	c.Assert(regexp.MustCompile("^unknown network foo$").MatchString(iodine.ToError(err).Error()), Equals, true)
-}
-
-func (s *MySuite) TestInvalidTcpAddr(c *C) {
-	os.Setenv(envCountKey, "")
-	n := &minNet{}
-	_, err := n.Listen("tcp", "abc")
-	c.Assert(err, Not(IsNil))
-	c.Assert(regexp.MustCompile("^missing port in address abc$").MatchString(iodine.ToError(err).Error()), Equals, true)
-}

pkg/server/rpc/auth.go

@@ -20,7 +20,7 @@ import (
 	"net/http"
 
 	"github.com/minio/minio/pkg/auth"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // AuthService auth service
@@ -32,15 +32,15 @@ type AuthReply struct {
 	SecretAccessKey string `json:"secretaccesskey"`
 }
 
-func getAuth(reply *AuthReply) error {
+func getAuth(reply *AuthReply) *probe.Error {
 	accessID, err := auth.GenerateAccessKeyID()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	reply.AccessKeyID = string(accessID)
 	secretID, err := auth.GenerateSecretAccessKey()
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	reply.SecretAccessKey = string(secretID)
 	return nil
@@ -48,5 +48,8 @@ func getAuth(reply *AuthReply) error {
 
 // Get auth keys
 func (s *AuthService) Get(r *http.Request, args *Args, reply *AuthReply) error {
-	return getAuth(reply)
+	if err := getAuth(reply); err != nil {
+		return err
+	}
+	return nil
 }

pkg/server/rpc/donut.go

@@ -20,7 +20,7 @@ import (
 	"net/http"
 
 	"github.com/minio/minio/pkg/donut"
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // DonutService donut service
@@ -40,14 +40,14 @@ type Reply struct {
 	Error   error  `json:"error"`
 }
 
-func setDonut(args *DonutArgs, reply *Reply) error {
+func setDonut(args *DonutArgs, reply *Reply) *probe.Error {
 	conf := &donut.Config{Version: "0.0.1"}
 	conf.DonutName = args.Name
 	conf.MaxSize = args.MaxSize
 	conf.NodeDiskMap = make(map[string][]string)
 	conf.NodeDiskMap[args.Hostname] = args.Disks
 	if err := donut.SaveConfig(conf); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	reply.Message = "success"
 	reply.Error = nil

pkg/server/rpc/sysinfo.go

@@ -21,7 +21,7 @@ import (
 	"os"
 	"runtime"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 )
 
 // SysInfoService -
@@ -45,7 +45,7 @@ type MemStatsReply struct {
 	runtime.MemStats `json:"memstats"`
 }
 
-func setSysInfoReply(sis *SysInfoReply) error {
+func setSysInfoReply(sis *SysInfoReply) *probe.Error {
 	sis.SysARCH = runtime.GOARCH
 	sis.SysOS = runtime.GOOS
 	sis.SysCPUS = runtime.NumCPU()
@@ -55,12 +55,12 @@ func setSysInfoReply(sis *SysInfoReply) error {
 	var err error
 	sis.Hostname, err = os.Hostname()
 	if err != nil {
-		return iodine.New(err, nil)
+		return probe.New(err)
 	}
 	return nil
 }
 
-func setMemStatsReply(sis *MemStatsReply) error {
+func setMemStatsReply(sis *MemStatsReply) *probe.Error {
 	var memStats runtime.MemStats
 	runtime.ReadMemStats(&memStats)
 	sis.MemStats = memStats
@@ -69,10 +69,16 @@ func setMemStatsReply(sis *MemStatsReply) error {
 
 // Get method
 func (s *SysInfoService) Get(r *http.Request, args *Args, reply *SysInfoReply) error {
-	return setSysInfoReply(reply)
+	if err := setSysInfoReply(reply); err != nil {
+		return err
+	}
+	return nil
 }
 
 // Get method
 func (s *MemStatsService) Get(r *http.Request, args *Args, reply *MemStatsReply) error {
-	return setMemStatsReply(reply)
+	if err := setMemStatsReply(reply); err != nil {
+		return err
+	}
+	return nil
 }

pkg/server/rpc_test.go

@@ -56,8 +56,7 @@ func (s *MyRPCSuite) TestMemStats(c *C) {
 	c.Assert(resp.StatusCode, Equals, http.StatusOK)
 
 	var reply rpc.MemStatsReply
-	err = jsonrpc.DecodeClientResponse(resp.Body, &reply)
-	c.Assert(err, IsNil)
+	c.Assert(jsonrpc.DecodeClientResponse(resp.Body, &reply), IsNil)
 	resp.Body.Close()
 	c.Assert(reply, Not(DeepEquals), rpc.MemStatsReply{})
 }
@@ -75,8 +74,7 @@ func (s *MyRPCSuite) TestSysInfo(c *C) {
 	c.Assert(resp.StatusCode, Equals, http.StatusOK)
 
 	var reply rpc.SysInfoReply
-	err = jsonrpc.DecodeClientResponse(resp.Body, &reply)
-	c.Assert(err, IsNil)
+	c.Assert(jsonrpc.DecodeClientResponse(resp.Body, &reply), IsNil)
 	resp.Body.Close()
 	c.Assert(reply, Not(DeepEquals), rpc.SysInfoReply{})
 }
@@ -94,8 +92,7 @@ func (s *MyRPCSuite) TestAuth(c *C) {
 	c.Assert(resp.StatusCode, Equals, http.StatusOK)
 
 	var reply rpc.AuthReply
-	err = jsonrpc.DecodeClientResponse(resp.Body, &reply)
-	c.Assert(err, IsNil)
+	c.Assert(jsonrpc.DecodeClientResponse(resp.Body, &reply), IsNil)
 	resp.Body.Close()
 	c.Assert(reply, Not(DeepEquals), rpc.AuthReply{})
 	c.Assert(len(reply.AccessKeyID), Equals, 20)

pkg/server/server.go

@@ -24,13 +24,13 @@ import (
 	"os"
 	"strings"
 
-	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/probe"
 	"github.com/minio/minio/pkg/server/api"
 	"github.com/minio/minio/pkg/server/minhttp"
 )
 
 // getAPI server instance
-func getAPIServer(conf api.Config, apiHandler http.Handler) (*http.Server, error) {
+func getAPIServer(conf api.Config, apiHandler http.Handler) (*http.Server, *probe.Error) {
 	// Minio server config
 	httpServer := &http.Server{
 		Addr:           conf.Address,
@@ -44,13 +44,13 @@ func getAPIServer(conf api.Config, apiHandler http.Handler) (*http.Server, error
 		httpServer.TLSConfig.Certificates = make([]tls.Certificate, 1)
 		httpServer.TLSConfig.Certificates[0], err = tls.LoadX509KeyPair(conf.CertFile, conf.KeyFile)
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 	}
 
 	host, port, err := net.SplitHostPort(conf.Address)
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, probe.New(err)
 	}
 
 	var hosts []string
@@ -60,7 +60,7 @@ func getAPIServer(conf api.Config, apiHandler http.Handler) (*http.Server, error
 	default:
 		addrs, err := net.InterfaceAddrs()
 		if err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, probe.New(err)
 		}
 		for _, addr := range addrs {
 			if addr.Network() == "ip+net" {
@@ -104,18 +104,18 @@ func startTM(a api.Minio) {
 }
 
 // StartServices starts basic services for a server
-func StartServices(conf api.Config) error {
+func StartServices(conf api.Config) *probe.Error {
 	apiHandler, minioAPI := getAPIHandler(conf)
 	apiServer, err := getAPIServer(conf, apiHandler)
 	if err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	rpcServer := getRPCServer(getRPCHandler())
 	// start ticket master
 	go startTM(minioAPI)
 
 	if err := minhttp.ListenAndServeLimited(conf.RateLimit, apiServer, rpcServer); err != nil {
-		return iodine.New(err, nil)
+		return err.Trace()
 	}
 	return nil
 }

pkg/utils/atomic/atomic.go

@@ -23,8 +23,6 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
-
-	"github.com/minio/minio/pkg/iodine"
 )
 
 // File container provided for atomic file writes
@@ -37,11 +35,11 @@ type File struct {
 func (f *File) Close() error {
 	// close the embedded fd
 	if err := f.File.Close(); err != nil {
-		return iodine.New(err, nil)
+		return err
 	}
 	// atomic rename to final destination
 	if err := os.Rename(f.Name(), f.file); err != nil {
-		return iodine.New(err, nil)
+		return err
 	}
 	return nil
 }
@@ -50,7 +48,7 @@ func (f *File) Close() error {
 func (f *File) CloseAndPurge() error {
 	// close the embedded fd
 	if err := f.File.Close(); err != nil {
-		return iodine.New(err, nil)
+		return err
 	}
 	if err := os.Remove(f.Name()); err != nil {
 		return err
@@ -63,17 +61,17 @@ func FileCreate(filePath string) (*File, error) {
 	// if parent directories do not exist, ioutil.TempFile doesn't create them
 	// handle such a case with os.MkdirAll()
 	if err := os.MkdirAll(filepath.Dir(filePath), 0700); err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err
 	}
 	f, err := ioutil.TempFile(filepath.Dir(filePath), filepath.Base(filePath))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, err
 	}
 	if err := os.Chmod(f.Name(), 0600); err != nil {
 		if err := os.Remove(f.Name()); err != nil {
-			return nil, iodine.New(err, nil)
+			return nil, err
 		}
-		return nil, iodine.New(err, nil)
+		return nil, err
 	}
 	return &File{File: f, file: filePath}, nil
 }