XL/FS: Rewrite in new format.

docs/backend/json-files/fs/format.json

@@ -0,0 +1,4 @@
+{
+  "format": "fs",
+  "version": "1"
+}

docs/backend/json-files/fs/fs.json

@@ -0,0 +1,14 @@
+{
+    "version": "1",
+    "format": "fs",
+    "minio": {
+        "release": "DEVELOPMENT.GOGET"
+    },
+    "parts": [
+        {
+            "name": "object1",
+            "size": 29,
+            "eTag": "",
+        },
+    ]
+}

docs/backend/json-files/fs/uploads.json

@@ -0,0 +1,10 @@
+{
+    "version": "1",
+    "format": "fs",
+    "uploadIds": [
+        {
+            "uploadID": "id",
+            "startTime": "time",
+        }
+    ]
+}

docs/backend/json-files/xl/format.json

@@ -0,0 +1,20 @@
+{
+  "xl": {
+    "jbod": [
+      "8aa2b1bc-0e5a-49e0-8221-05228336b040",
+      "3467a69b-0266-478a-9e10-e819447e4545",
+      "d4a4505b-4e4f-4864-befd-4f36adb0bc66",
+      "592b6583-ca26-47af-b991-ba6d097e34e8",
+      "c7ef69f0-dbf5-4c0e-b167-d30a441bad7e",
+      "f0b36ea3-fe96-4f2b-bced-22c7f33e0e0c",
+      "b83abf39-e39d-4e7b-8e16-6f9953455a48",
+      "7d63dfc9-5441-4243-bd36-de8db0691982",
+      "c1bbffc5-81f9-4251-9398-33a959b3ce37",
+      "64408f94-26e0-4277-9593-2d703f4d5a91"
+    ],
+    "disk": "8aa2b1bc-0e5a-49e0-8221-05228336b040",
+    "version": "1"
+  },
+  "format": "xl",
+  "version": "1"
+}

docs/backend/json-files/xl/uploads.json

@@ -0,0 +1,10 @@
+{
+    "version": "1",
+    "format": "xl",
+    "uploadIds": [
+        {
+            "uploadID": "id",
+            "startTime": "time",
+        }
+    ]
+}

docs/backend/json-files/xl/xl.json

@@ -0,0 +1,44 @@
+{
+    "parts": [
+        {
+            "size": 5242880,
+            "etag": "3565c6e741e69a007a5ac7db893a62b5",
+            "name": "object1"
+        },
+        {
+            "size": 5242880,
+            "etag": "d416712335c280ab1e39498552937764",
+            "name": "object2"
+        },
+        {
+            "size": 4338324,
+            "etag": "8a98c5c54d81c6c95ed9bdcaeb941aaf",
+            "name": "object3"
+        }
+    ],
+    "meta": {
+        "md5Sum": "97586a5290d4f5a41328062d6a7da593-3",
+        "content-type": "application\/octet-stream",
+        "content-encoding": ""
+    },
+    "minio": {
+        "release": "DEVELOPMENT.GOGET"
+    },
+    "erasure": {
+        "index": 2,
+        "distribution": [ 1, 3, 4, 2, 5, 8, 7, 6, 9 ],
+        "blockSize": 4194304,
+        "parity": 5,
+        "data": 5
+    },
+    "checksum": {
+        "enable": false,
+    },
+    "stat": {
+        "version": 0,
+        "modTime": "2016-05-24T00:09:40.122390255Z",
+        "size": 14824084
+    },
+    "format": "xl",
+    "version": "1"
+}

erasure-createfile.go

@@ -0,0 +1,172 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"io"
+	"sync"
+)
+
+// cleanupCreateFileOps - cleans up all the temporary files and other
+// temporary data upon any failure.
+func (e erasure) cleanupCreateFileOps(volume, path string, writers []io.WriteCloser) {
+	// Close and remove temporary writers.
+	for _, writer := range writers {
+		if err := safeCloseAndRemove(writer); err != nil {
+			errorIf(err, "Failed to close writer.")
+		}
+	}
+	// Remove any temporary written data.
+	for _, disk := range e.storageDisks {
+		if err := disk.DeleteFile(volume, path); err != nil {
+			errorIf(err, "Unable to delete file.")
+		}
+	}
+}
+
+// WriteErasure reads predefined blocks, encodes them and writes to
+// configured storage disks.
+func (e erasure) writeErasure(volume, path string, reader *io.PipeReader, wcloser *waitCloser) {
+	// Release the block writer upon function return.
+	defer wcloser.release()
+
+	writers := make([]io.WriteCloser, len(e.storageDisks))
+
+	// Initialize all writers.
+	for index, disk := range e.storageDisks {
+		writer, err := disk.CreateFile(volume, path)
+		if err != nil {
+			e.cleanupCreateFileOps(volume, path, writers)
+			reader.CloseWithError(err)
+			return
+		}
+		writers[index] = writer
+	}
+
+	// Allocate 4MiB block size buffer for reading.
+	dataBuffer := make([]byte, erasureBlockSize)
+	for {
+		// Read up to allocated block size.
+		n, err := io.ReadFull(reader, dataBuffer)
+		if err != nil {
+			// Any unexpected errors, close the pipe reader with error.
+			if err != io.ErrUnexpectedEOF && err != io.EOF {
+				// Remove all temp writers.
+				e.cleanupCreateFileOps(volume, path, writers)
+				reader.CloseWithError(err)
+				return
+			}
+		}
+		// At EOF break out.
+		if err == io.EOF {
+			break
+		}
+		if n > 0 {
+			// Split the input buffer into data and parity blocks.
+			var dataBlocks [][]byte
+			dataBlocks, err = e.ReedSolomon.Split(dataBuffer[0:n])
+			if err != nil {
+				// Remove all temp writers.
+				e.cleanupCreateFileOps(volume, path, writers)
+				reader.CloseWithError(err)
+				return
+			}
+
+			// Encode parity blocks using data blocks.
+			err = e.ReedSolomon.Encode(dataBlocks)
+			if err != nil {
+				// Remove all temp writers upon error.
+				e.cleanupCreateFileOps(volume, path, writers)
+				reader.CloseWithError(err)
+				return
+			}
+
+			var wg = &sync.WaitGroup{}
+			var wErrs = make([]error, len(writers))
+			// Write encoded data to quorum disks in parallel.
+			for index, writer := range writers {
+				if writer == nil {
+					continue
+				}
+				wg.Add(1)
+				// Write encoded data in routine.
+				go func(index int, writer io.Writer) {
+					defer wg.Done()
+					encodedData := dataBlocks[index]
+					_, wErr := writers[index].Write(encodedData)
+					if wErr != nil {
+						wErrs[index] = wErr
+						return
+					}
+					wErrs[index] = nil
+				}(index, writer)
+			}
+			wg.Wait()
+
+			// Cleanup and return on first non-nil error.
+			for _, wErr := range wErrs {
+				if wErr == nil {
+					continue
+				}
+				// Remove all temp writers upon error.
+				e.cleanupCreateFileOps(volume, path, writers)
+				reader.CloseWithError(wErr)
+				return
+			}
+		}
+	}
+
+	// Close all writers and metadata writers in routines.
+	for _, writer := range writers {
+		if writer == nil {
+			continue
+		}
+		// Safely wrote, now rename to its actual location.
+		if err := writer.Close(); err != nil {
+			// Remove all temp writers upon error.
+			e.cleanupCreateFileOps(volume, path, writers)
+			reader.CloseWithError(err)
+			return
+		}
+	}
+
+	// Close the pipe reader and return.
+	reader.Close()
+	return
+}
+
+// CreateFile - create a file.
+func (e erasure) CreateFile(volume, path string) (writeCloser io.WriteCloser, err error) {
+	if !isValidVolname(volume) {
+		return nil, errInvalidArgument
+	}
+	if !isValidPath(path) {
+		return nil, errInvalidArgument
+	}
+
+	// Initialize pipe for data pipe line.
+	pipeReader, pipeWriter := io.Pipe()
+
+	// Initialize a new wait closer, implements both Write and Close.
+	wcloser := newWaitCloser(pipeWriter)
+
+	// Start erasure encoding in routine, reading data block by block from pipeReader.
+	go e.writeErasure(volume, path, pipeReader, wcloser)
+
+	// Return the writer, caller should start writing to this.
+	return wcloser, nil
+}

erasure-readfile.go

@@ -18,14 +18,12 @@ package main
 
 import (
 	"errors"
-	"fmt"
 	"io"
-	slashpath "path"
 	"sync"
 )
 
-// ReadFile - read file
-func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, error) {
+// ReadFile - decoded erasure coded file.
+func (e erasure) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, error) {
 	// Input validation.
 	if !isValidVolname(volume) {
 		return nil, errInvalidArgument
@@ -34,52 +32,34 @@ func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, er
 		return nil, errInvalidArgument
 	}
 
-	onlineDisks, metadata, heal, err := xl.listOnlineDisks(volume, path)
-	if err != nil {
-		return nil, err
+	var wg = &sync.WaitGroup{}
+
+	readers := make([]io.ReadCloser, len(e.storageDisks))
+	for index, disk := range e.storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			// If disk.ReadFile returns error and we don't have read
+			// quorum it will be taken care as ReedSolomon.Reconstruct()
+			// will fail later.
+			offset := int64(0)
+			if reader, err := disk.ReadFile(volume, path, offset); err == nil {
+				readers[index] = reader
+			}
+		}(index, disk)
 	}
 
-	if heal {
-		// Heal in background safely, since we already have read
-		// quorum disks. Let the reads continue.
-		go func() {
-			hErr := xl.healFile(volume, path)
-			errorIf(hErr, "Unable to heal file "+volume+"/"+path+".")
-		}()
-	}
-
-	readers := make([]io.ReadCloser, len(xl.storageDisks))
-	for index, disk := range onlineDisks {
-		if disk == nil {
-			continue
-		}
-		erasurePart := slashpath.Join(path, fmt.Sprintf("file.%d", index))
-		// If disk.ReadFile returns error and we don't have read quorum it will be taken care as
-		// ReedSolomon.Reconstruct() will fail later.
-		var reader io.ReadCloser
-		offset := int64(0)
-		if reader, err = disk.ReadFile(volume, erasurePart, offset); err == nil {
-			readers[index] = reader
-		}
-	}
+	wg.Wait()
 
 	// Initialize pipe.
 	pipeReader, pipeWriter := io.Pipe()
+
 	go func() {
-		var totalLeft = metadata.Stat.Size
-		// Read until the totalLeft.
-		for totalLeft > 0 {
-			// Figure out the right blockSize as it was encoded before.
-			var curBlockSize int64
-			if metadata.Erasure.BlockSize < totalLeft {
-				curBlockSize = metadata.Erasure.BlockSize
-			} else {
-				curBlockSize = totalLeft
-			}
+		// Read until EOF.
+		for {
 			// Calculate the current encoded block size.
-			curEncBlockSize := getEncodedBlockLen(curBlockSize, metadata.Erasure.DataBlocks)
-			enBlocks := make([][]byte, len(xl.storageDisks))
-			var wg = &sync.WaitGroup{}
+			curEncBlockSize := getEncodedBlockLen(erasureBlockSize, e.DataBlocks)
+			enBlocks := make([][]byte, len(e.storageDisks))
 			// Loop through all readers and read.
 			for index, reader := range readers {
 				// Initialize shard slice and fill the data from each parts.
@@ -87,19 +67,28 @@ func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, er
 				if reader == nil {
 					continue
 				}
-				// Parallelize reading.
-				wg.Add(1)
-				go func(index int, reader io.Reader) {
-					defer wg.Done()
-					// Read the necessary blocks.
-					_, rErr := io.ReadFull(reader, enBlocks[index])
-					if rErr != nil && rErr != io.ErrUnexpectedEOF {
-						readers[index] = nil
+				// Read the necessary blocks.
+				n, rErr := io.ReadFull(reader, enBlocks[index])
+				if rErr == io.EOF {
+					// Close the pipe.
+					pipeWriter.Close()
+
+					// Cleanly close all the underlying data readers.
+					for _, reader := range readers {
+						if reader == nil {
+							continue
+						}
+						reader.Close()
 					}
-				}(index, reader)
+					return
+				}
+				if rErr != nil && rErr != io.ErrUnexpectedEOF {
+					readers[index].Close()
+					readers[index] = nil
+					continue
+				}
+				enBlocks[index] = enBlocks[index][:n]
 			}
-			// Wait for the read routines to finish.
-			wg.Wait()
 
 			// Check blocks if they are all zero in length.
 			if checkBlockSize(enBlocks) == 0 {
@@ -108,8 +97,7 @@ func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, er
 			}
 
 			// Verify the blocks.
-			var ok bool
-			ok, err = xl.ReedSolomon.Verify(enBlocks)
+			ok, err := e.ReedSolomon.Verify(enBlocks)
 			if err != nil {
 				pipeWriter.CloseWithError(err)
 				return
@@ -123,13 +111,13 @@ func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, er
 						enBlocks[index] = nil
 					}
 				}
-				err = xl.ReedSolomon.Reconstruct(enBlocks)
+				err = e.ReedSolomon.Reconstruct(enBlocks)
 				if err != nil {
 					pipeWriter.CloseWithError(err)
 					return
 				}
 				// Verify reconstructed blocks again.
-				ok, err = xl.ReedSolomon.Verify(enBlocks)
+				ok, err = e.ReedSolomon.Verify(enBlocks)
 				if err != nil {
 					pipeWriter.CloseWithError(err)
 					return
@@ -143,16 +131,14 @@ func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, er
 			}
 
 			// Get all the data blocks.
-			dataBlocks := getDataBlocks(enBlocks, metadata.Erasure.DataBlocks, int(curBlockSize))
+			dataBlocks := getDataBlocks(enBlocks, e.DataBlocks)
 
 			// Verify if the offset is right for the block, if not move to
 			// the next block.
-
 			if startOffset > 0 {
 				startOffset = startOffset - int64(len(dataBlocks))
 				// Start offset is greater than or equal to zero, skip the dataBlocks.
 				if startOffset >= 0 {
-					totalLeft = totalLeft - metadata.Erasure.BlockSize
 					continue
 				}
 				// Now get back the remaining offset if startOffset is negative.
@@ -168,20 +154,6 @@ func (xl XL) ReadFile(volume, path string, startOffset int64) (io.ReadCloser, er
 
 			// Reset offset to '0' to read rest of the blocks.
 			startOffset = int64(0)
-
-			// Save what's left after reading erasureBlockSize.
-			totalLeft = totalLeft - metadata.Erasure.BlockSize
-		}
-
-		// Cleanly end the pipe after a successful decoding.
-		pipeWriter.Close()
-
-		// Cleanly close all the underlying data readers.
-		for _, reader := range readers {
-			if reader == nil {
-				continue
-			}
-			reader.Close()
 		}
 	}()
 

erasure-utils.go

@@ -17,12 +17,19 @@
 package main
 
 // getDataBlocks - fetches the data block only part of the input encoded blocks.
-func getDataBlocks(enBlocks [][]byte, dataBlocks int, curBlockSize int) []byte {
+func getDataBlocks(enBlocks [][]byte, dataBlocks int) []byte {
 	var data []byte
 	for _, block := range enBlocks[:dataBlocks] {
-		data = append(data, block...)
+		var newBlock []byte
+		// FIXME: Find a better way to skip the padding zeros.
+		for _, b := range block {
+			if b == 0 {
+				continue
+			}
+			newBlock = append(newBlock, b)
+		}
+		data = append(data, newBlock...)
 	}
-	data = data[:curBlockSize]
 	return data
 }
 

erasure.go

@@ -0,0 +1,60 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"errors"
+
+	"github.com/klauspost/reedsolomon"
+)
+
+// erasure storage layer.
+type erasure struct {
+	ReedSolomon  reedsolomon.Encoder // Erasure encoder/decoder.
+	DataBlocks   int
+	ParityBlocks int
+	storageDisks []StorageAPI
+}
+
+// errUnexpected - returned for any unexpected error.
+var errUnexpected = errors.New("Unexpected error - please report at https://github.com/minio/minio/issues")
+
+// newErasure instantiate a new erasure.
+func newErasure(disks []StorageAPI) (*erasure, error) {
+	// Initialize E.
+	e := &erasure{}
+
+	// Calculate data and parity blocks.
+	dataBlocks, parityBlocks := len(disks)/2, len(disks)/2
+
+	// Initialize reed solomon encoding.
+	rs, err := reedsolomon.New(dataBlocks, parityBlocks)
+	if err != nil {
+		return nil, err
+	}
+
+	// Save the reedsolomon.
+	e.DataBlocks = dataBlocks
+	e.ParityBlocks = parityBlocks
+	e.ReedSolomon = rs
+
+	// Save all the initialized storage disks.
+	e.storageDisks = disks
+
+	// Return successfully initialized.
+	return e, nil
+}

fs-objects-multipart.go

@@ -1,150 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"fmt"
-	"io"
-	"path"
-)
-
-// ListMultipartUploads - list multipart uploads.
-func (fs fsObjects) ListMultipartUploads(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
-	return listMultipartUploadsCommon(fs, bucket, prefix, keyMarker, uploadIDMarker, delimiter, maxUploads)
-}
-
-// NewMultipartUpload - initialize a new multipart upload, returns a unique id.
-func (fs fsObjects) NewMultipartUpload(bucket, object string, meta map[string]string) (string, error) {
-	meta = make(map[string]string) // Reset the meta value, we are not going to save headers for fs.
-	return newMultipartUploadCommon(fs.storage, bucket, object, meta)
-}
-
-// PutObjectPart - writes the multipart upload chunks.
-func (fs fsObjects) PutObjectPart(bucket, object, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
-	return putObjectPartCommon(fs.storage, bucket, object, uploadID, partID, size, data, md5Hex)
-}
-
-func (fs fsObjects) ListObjectParts(bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
-	return listObjectPartsCommon(fs.storage, bucket, object, uploadID, partNumberMarker, maxParts)
-}
-
-func (fs fsObjects) CompleteMultipartUpload(bucket string, object string, uploadID string, parts []completePart) (string, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return "", BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify whether the bucket exists.
-	if !isBucketExist(fs.storage, bucket) {
-		return "", BucketNotFound{Bucket: bucket}
-	}
-	if !IsValidObjectName(object) {
-		return "", ObjectNameInvalid{
-			Bucket: bucket,
-			Object: object,
-		}
-	}
-	if !isUploadIDExists(fs.storage, bucket, object, uploadID) {
-		return "", InvalidUploadID{UploadID: uploadID}
-	}
-
-	// Calculate s3 compatible md5sum for complete multipart.
-	s3MD5, err := completeMultipartMD5(parts...)
-	if err != nil {
-		return "", err
-	}
-
-	tempObj := path.Join(tmpMetaPrefix, bucket, object, uploadID, incompleteFile)
-	fileWriter, err := fs.storage.CreateFile(minioMetaBucket, tempObj)
-	if err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Loop through all parts, validate them and then commit to disk.
-	for i, part := range parts {
-		// Construct part suffix.
-		partSuffix := fmt.Sprintf("%.5d.%s", part.PartNumber, part.ETag)
-		multipartPartFile := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffix)
-		var fi FileInfo
-		fi, err = fs.storage.StatFile(minioMetaBucket, multipartPartFile)
-		if err != nil {
-			if err == errFileNotFound {
-				return "", InvalidPart{}
-			}
-			return "", err
-		}
-		// All parts except the last part has to be atleast 5MB.
-		if (i < len(parts)-1) && !isMinAllowedPartSize(fi.Size) {
-			return "", PartTooSmall{}
-		}
-		var fileReader io.ReadCloser
-		fileReader, err = fs.storage.ReadFile(minioMetaBucket, multipartPartFile, 0)
-		if err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", clErr
-			}
-			if err == errFileNotFound {
-				return "", InvalidPart{}
-			}
-			return "", err
-		}
-		_, err = io.Copy(fileWriter, fileReader)
-		if err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", clErr
-			}
-			return "", err
-		}
-		err = fileReader.Close()
-		if err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", clErr
-			}
-			return "", err
-		}
-	}
-
-	err = fileWriter.Close()
-	if err != nil {
-		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-			return "", clErr
-		}
-		return "", err
-	}
-
-	// Rename the file back to original location, if not delete the
-	// temporary object.
-	err = fs.storage.RenameFile(minioMetaBucket, tempObj, bucket, object)
-	if err != nil {
-		if derr := fs.storage.DeleteFile(minioMetaBucket, tempObj); derr != nil {
-			return "", toObjectErr(derr, minioMetaBucket, tempObj)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Cleanup all the parts if everything else has been safely committed.
-	if err = cleanupUploadedParts(fs.storage, bucket, object, uploadID); err != nil {
-		return "", err
-	}
-
-	// Return md5sum.
-	return s3MD5, nil
-}
-
-// AbortMultipartUpload - aborts a multipart upload.
-func (fs fsObjects) AbortMultipartUpload(bucket, object, uploadID string) error {
-	return abortMultipartUploadCommon(fs.storage, bucket, object, uploadID)
-}

fs-v1-metadata.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"path"
+	"sort"
+)
+
+// A fsMetaV1 represents a metadata header mapping keys to sets of values.
+type fsMetaV1 struct {
+	Version string `json:"version"`
+	Format  string `json:"format"`
+	Minio   struct {
+		Release string `json:"release"`
+	} `json:"minio"`
+	Checksum struct {
+		Enable bool `json:"enable"`
+	} `json:"checksum"`
+	Parts []objectPartInfo `json:"parts,omitempty"`
+}
+
+// ReadFrom - read from implements io.ReaderFrom interface for
+// unmarshalling fsMetaV1.
+func (m *fsMetaV1) ReadFrom(reader io.Reader) (n int64, err error) {
+	var buffer bytes.Buffer
+	n, err = buffer.ReadFrom(reader)
+	if err != nil {
+		return 0, err
+	}
+	err = json.Unmarshal(buffer.Bytes(), m)
+	return n, err
+}
+
+// WriteTo - write to implements io.WriterTo interface for marshalling fsMetaV1.
+func (m fsMetaV1) WriteTo(writer io.Writer) (n int64, err error) {
+	metadataBytes, err := json.Marshal(m)
+	if err != nil {
+		return 0, err
+	}
+	p, err := writer.Write(metadataBytes)
+	return int64(p), err
+}
+
+// SearchObjectPart - search object part name and etag.
+func (m fsMetaV1) SearchObjectPart(name string, etag string) int {
+	for i, part := range m.Parts {
+		if name == part.Name && etag == part.ETag {
+			return i
+		}
+	}
+	return -1
+}
+
+// AddObjectPart - add a new object part in order.
+func (m *fsMetaV1) AddObjectPart(name string, etag string, size int64) {
+	m.Parts = append(m.Parts, objectPartInfo{
+		Name: name,
+		ETag: etag,
+		Size: size,
+	})
+	sort.Sort(byPartName(m.Parts))
+}
+
+const (
+	fsMetaJSONFile = "fs.json"
+)
+
+// readFSMetadata - read `fs.json`.
+func (fs fsObjects) readFSMetadata(bucket, object string) (fsMeta fsMetaV1, err error) {
+	r, err := fs.storage.ReadFile(bucket, path.Join(object, fsMetaJSONFile), int64(0))
+	if err != nil {
+		return fsMetaV1{}, err
+	}
+	defer r.Close()
+	_, err = fsMeta.ReadFrom(r)
+	if err != nil {
+		return fsMetaV1{}, err
+	}
+	return fsMeta, nil
+}
+
+// writeFSMetadata - write `fs.json`.
+func (fs fsObjects) writeFSMetadata(bucket, prefix string, fsMeta fsMetaV1) error {
+	// Initialize metadata map, save all erasure related metadata.
+	fsMeta.Minio.Release = minioReleaseTag
+	w, err := fs.storage.CreateFile(bucket, path.Join(prefix, fsMetaJSONFile))
+	if err != nil {
+		return err
+	}
+	_, err = fsMeta.WriteTo(w)
+	if err != nil {
+		if mErr := safeCloseAndRemove(w); mErr != nil {
+			return mErr
+		}
+		return err
+	}
+	if err = w.Close(); err != nil {
+		if mErr := safeCloseAndRemove(w); mErr != nil {
+			return mErr
+		}
+		return err
+	}
+	return nil
+}

fs-v1-multipart.go

@@ -19,66 +19,39 @@ package main
 import (
 	"crypto/md5"
 	"encoding/hex"
-	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"path"
-	"sort"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/skyrings/skyring-common/tools/uuid"
 )
 
-const (
-	incompleteFile  = "00000.incomplete"
-	uploadsJSONFile = "uploads.json"
-)
-
-// createUploadsJSON - create uploads.json placeholder file.
-func createUploadsJSON(storage StorageAPI, bucket, object, uploadID string) error {
-	// Place holder uploads.json
-	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
-	uploadsJSONSuffix := fmt.Sprintf("%s.%s", uploadID, uploadsJSONFile)
-	tmpUploadsPath := path.Join(tmpMetaPrefix, bucket, object, uploadsJSONSuffix)
-	w, err := storage.CreateFile(minioMetaBucket, uploadsPath)
+// Checks whether bucket exists.
+func (fs fsObjects) isBucketExist(bucket string) bool {
+	// Check whether bucket exists.
+	_, err := fs.storage.StatVol(bucket)
 	if err != nil {
-		return err
-	}
-	if err = w.Close(); err != nil {
-		if clErr := safeCloseAndRemove(w); clErr != nil {
-			return clErr
-		}
-		return err
-	}
-	_, err = storage.StatFile(minioMetaBucket, uploadsPath)
-	if err != nil {
-		if err == errFileNotFound {
-			err = storage.RenameFile(minioMetaBucket, tmpUploadsPath, minioMetaBucket, uploadsPath)
-			if err == nil {
-				return nil
-			}
-		}
-		if derr := storage.DeleteFile(minioMetaBucket, tmpUploadsPath); derr != nil {
-			return derr
+		if err == errVolumeNotFound {
+			return false
 		}
-		return err
+		errorIf(err, "Stat failed on bucket "+bucket+".")
+		return false
 	}
-	return nil
+	return true
 }
 
-/// Common multipart object layer functions.
-
-// newMultipartUploadCommon - initialize a new multipart, is a common
-// function for both object layers.
-func newMultipartUploadCommon(storage StorageAPI, bucket string, object string, meta map[string]string) (uploadID string, err error) {
+// newMultipartUploadCommon - initialize a new multipart, is a common function for both object layers.
+func (fs fsObjects) newMultipartUploadCommon(bucket string, object string, meta map[string]string) (uploadID string, err error) {
 	// Verify if bucket name is valid.
 	if !IsValidBucketName(bucket) {
 		return "", BucketNameInvalid{Bucket: bucket}
 	}
 	// Verify whether the bucket exists.
-	if !isBucketExist(storage, bucket) {
+	if !fs.isBucketExist(bucket) {
 		return "", BucketNotFound{Bucket: bucket}
 	}
 	// Verify if object name is valid.
@@ -89,266 +62,68 @@ func newMultipartUploadCommon(storage StorageAPI, bucket string, object string,
 	if meta == nil {
 		meta = make(map[string]string)
 	}
+
+	fsMeta := fsMetaV1{}
+	fsMeta.Format = "fs"
+	fsMeta.Version = "1"
+
 	// This lock needs to be held for any changes to the directory contents of ".minio/multipart/object/"
 	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
 	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
-	// Loops through until successfully generates a new unique upload id.
-	for {
-		uuid, err := uuid.New()
-		if err != nil {
-			return "", err
-		}
-		uploadID := uuid.String()
-		// Create placeholder file 'uploads.json'
-		err = createUploadsJSON(storage, bucket, object, uploadID)
-		if err != nil {
-			return "", err
-		}
-		uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID, incompleteFile)
-		incompleteSuffix := fmt.Sprintf("%s.%s", uploadID, incompleteFile)
-		tempUploadIDPath := path.Join(tmpMetaPrefix, bucket, object, incompleteSuffix)
-		if _, err = storage.StatFile(minioMetaBucket, uploadIDPath); err != nil {
-			if err != errFileNotFound {
-				return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
-			}
-			// uploadIDPath doesn't exist, so create empty file to reserve the name
-			var w io.WriteCloser
-			if w, err = storage.CreateFile(minioMetaBucket, tempUploadIDPath); err != nil {
-				return "", toObjectErr(err, minioMetaBucket, tempUploadIDPath)
-			}
-
-			// Encode the uploaded metadata into incomplete file.
-			encoder := json.NewEncoder(w)
-			err = encoder.Encode(&meta)
-			if err != nil {
-				if clErr := safeCloseAndRemove(w); clErr != nil {
-					return "", toObjectErr(clErr, minioMetaBucket, tempUploadIDPath)
-				}
-				return "", toObjectErr(err, minioMetaBucket, tempUploadIDPath)
-			}
-
-			// Close the writer.
-			if err = w.Close(); err != nil {
-				if clErr := safeCloseAndRemove(w); clErr != nil {
-					return "", toObjectErr(clErr, minioMetaBucket, tempUploadIDPath)
-				}
-				return "", toObjectErr(err, minioMetaBucket, tempUploadIDPath)
-			}
-
-			// Rename the file to the actual location from temporary path.
-			err = storage.RenameFile(minioMetaBucket, tempUploadIDPath, minioMetaBucket, uploadIDPath)
-			if err != nil {
-				if derr := storage.DeleteFile(minioMetaBucket, tempUploadIDPath); derr != nil {
-					return "", toObjectErr(derr, minioMetaBucket, tempUploadIDPath)
-				}
-				return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
-			}
-			return uploadID, nil
-		}
-		// uploadIDPath already exists.
-		// loop again to try with different uuid generated.
-	}
-}
-
-// putObjectPartCommon - put object part.
-func putObjectPartCommon(storage StorageAPI, bucket string, object string, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return "", BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify whether the bucket exists.
-	if !isBucketExist(storage, bucket) {
-		return "", BucketNotFound{Bucket: bucket}
-	}
-	if !IsValidObjectName(object) {
-		return "", ObjectNameInvalid{Bucket: bucket, Object: object}
-	}
-	if !isUploadIDExists(storage, bucket, object, uploadID) {
-		return "", InvalidUploadID{UploadID: uploadID}
-	}
-	// Hold read lock on the uploadID so that no one aborts it.
-	nsMutex.RLock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
-	defer nsMutex.RUnlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
-
-	// Hold write lock on the part so that there is no parallel upload on the part.
-	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID, strconv.Itoa(partID)))
-	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID, strconv.Itoa(partID)))
-
-	partSuffix := fmt.Sprintf("%s.%.5d", uploadID, partID)
-	partSuffixPath := path.Join(tmpMetaPrefix, bucket, object, partSuffix)
-	fileWriter, err := storage.CreateFile(minioMetaBucket, partSuffixPath)
-	if err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Initialize md5 writer.
-	md5Writer := md5.New()
-
-	// Instantiate a new multi writer.
-	multiWriter := io.MultiWriter(md5Writer, fileWriter)
-
-	// Instantiate checksum hashers and create a multiwriter.
-	if size > 0 {
-		if _, err = io.CopyN(multiWriter, data, size); err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", toObjectErr(clErr, bucket, object)
-			}
-			return "", toObjectErr(err, bucket, object)
-		}
-		// Reader shouldn't have more data what mentioned in size argument.
-		// reading one more byte from the reader to validate it.
-		// expected to fail, success validates existence of more data in the reader.
-		if _, err = io.CopyN(ioutil.Discard, data, 1); err == nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", toObjectErr(clErr, bucket, object)
-			}
-			return "", UnExpectedDataSize{Size: int(size)}
-		}
-	} else {
-		if _, err = io.Copy(multiWriter, data); err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", toObjectErr(clErr, bucket, object)
-			}
-			return "", toObjectErr(err, bucket, object)
-		}
-	}
 
-	newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
-	if md5Hex != "" {
-		if newMD5Hex != md5Hex {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", toObjectErr(clErr, bucket, object)
-			}
-			return "", BadDigest{md5Hex, newMD5Hex}
-		}
-	}
-	err = fileWriter.Close()
-	if err != nil {
-		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-			return "", toObjectErr(clErr, bucket, object)
-		}
+	uploadID = getUUID()
+	initiated := time.Now().UTC()
+	// Create 'uploads.json'
+	if err = writeUploadJSON(bucket, object, uploadID, initiated, fs.storage); err != nil {
 		return "", err
 	}
-
-	partSuffixMD5 := fmt.Sprintf("%.5d.%s", partID, newMD5Hex)
-	partSuffixMD5Path := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffixMD5)
-	if _, err = storage.StatFile(minioMetaBucket, partSuffixMD5Path); err == nil {
-		// Part already uploaded as md5sum matches with the previous part.
-		// Just delete the temporary file.
-		if err = storage.DeleteFile(minioMetaBucket, partSuffixPath); err != nil {
-			return "", toObjectErr(err, minioMetaBucket, partSuffixPath)
-		}
-		return newMD5Hex, nil
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	tempUploadIDPath := path.Join(tmpMetaPrefix, bucket, object, uploadID)
+	if err = fs.writeFSMetadata(minioMetaBucket, tempUploadIDPath, fsMeta); err != nil {
+		return "", toObjectErr(err, minioMetaBucket, tempUploadIDPath)
 	}
-	err = storage.RenameFile(minioMetaBucket, partSuffixPath, minioMetaBucket, partSuffixMD5Path)
+	err = fs.storage.RenameFile(minioMetaBucket, path.Join(tempUploadIDPath, fsMetaJSONFile), minioMetaBucket, path.Join(uploadIDPath, fsMetaJSONFile))
 	if err != nil {
-		if derr := storage.DeleteFile(minioMetaBucket, partSuffixPath); derr != nil {
-			return "", toObjectErr(derr, minioMetaBucket, partSuffixPath)
-		}
-		return "", toObjectErr(err, minioMetaBucket, partSuffixMD5Path)
-	}
-	return newMD5Hex, nil
-}
-
-// Wrapper to which removes all the uploaded parts after a successful
-// complete multipart upload.
-func cleanupUploadedParts(storage StorageAPI, bucket, object, uploadID string) error {
-	return cleanupDir(storage, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
-}
-
-// abortMultipartUploadCommon - aborts a multipart upload, common
-// function used by both object layers.
-func abortMultipartUploadCommon(storage StorageAPI, bucket, object, uploadID string) error {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return BucketNameInvalid{Bucket: bucket}
-	}
-	if !isBucketExist(storage, bucket) {
-		return BucketNotFound{Bucket: bucket}
-	}
-	if !IsValidObjectName(object) {
-		return ObjectNameInvalid{Bucket: bucket, Object: object}
-	}
-	if !isUploadIDExists(storage, bucket, object, uploadID) {
-		return InvalidUploadID{UploadID: uploadID}
-	}
-
-	// Hold lock so that there is no competing complete-multipart-upload or put-object-part.
-	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
-	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
-
-	if err := cleanupUploadedParts(storage, bucket, object, uploadID); err != nil {
-		return err
-	}
-
-	// Validate if there are other incomplete upload-id's present for
-	// the object, if yes do not attempt to delete 'uploads.json'.
-	if entries, err := storage.ListDir(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object)); err == nil {
-		if len(entries) > 1 {
-			return nil
+		if dErr := fs.storage.DeleteFile(minioMetaBucket, path.Join(tempUploadIDPath, fsMetaJSONFile)); dErr != nil {
+			return "", toObjectErr(dErr, minioMetaBucket, tempUploadIDPath)
 		}
+		return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
 	}
-
-	uploadsJSONPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
-	if err := storage.DeleteFile(minioMetaBucket, uploadsJSONPath); err != nil {
-		return err
-	}
-
-	return nil
+	// Return success.
+	return uploadID, nil
 }
 
-// isIncompleteMultipart - is object incomplete multipart.
-func isIncompleteMultipart(storage StorageAPI, objectPath string) (bool, error) {
-	_, err := storage.StatFile(minioMetaBucket, path.Join(objectPath, uploadsJSONFile))
+func isMultipartObject(storage StorageAPI, bucket, prefix string) bool {
+	_, err := storage.StatFile(bucket, path.Join(prefix, fsMetaJSONFile))
 	if err != nil {
 		if err == errFileNotFound {
-			return false, nil
+			return false
 		}
-		return false, err
+		errorIf(err, "Unable to access "+path.Join(prefix, fsMetaJSONFile))
+		return false
 	}
-	return true, nil
+	return true
 }
 
-// listLeafEntries - lists all entries if a given prefixPath is a leaf
-// directory, returns error if any - returns empty list if prefixPath
-// is not a leaf directory.
-func listLeafEntries(storage StorageAPI, prefixPath string) (entries []string, err error) {
-	var ok bool
-	if ok, err = isIncompleteMultipart(storage, prefixPath); err != nil {
-		return nil, err
-	} else if !ok {
-		return nil, nil
-	}
-	entries, err = storage.ListDir(minioMetaBucket, prefixPath)
+// listUploadsInfo - list all uploads info.
+func (fs fsObjects) listUploadsInfo(prefixPath string) (uploads []uploadInfo, err error) {
+	splitPrefixes := strings.SplitN(prefixPath, "/", 3)
+	uploadIDs, err := getUploadIDs(splitPrefixes[1], splitPrefixes[2], fs.storage)
 	if err != nil {
-		return nil, err
-	}
-	var newEntries []string
-	for _, entry := range entries {
-		if strings.HasSuffix(entry, slashSeparator) {
-			newEntries = append(newEntries, entry)
+		if err == errFileNotFound {
+			return []uploadInfo{}, nil
 		}
+		return nil, err
 	}
-	return newEntries, nil
+	uploads = uploadIDs.Uploads
+	return uploads, nil
 }
 
-// listMetaBucketMultipartFiles - list all files at a given prefix inside minioMetaBucket.
-func listMetaBucketMultipartFiles(layer ObjectLayer, prefixPath string, markerPath string, recursive bool, maxKeys int) (fileInfos []FileInfo, eof bool, err error) {
-	var storage StorageAPI
-	switch l := layer.(type) {
-	case fsObjects:
-		storage = l.storage
-	case xlObjects:
-		storage = l.storage
-	}
-
-	if recursive && markerPath != "" {
-		markerPath = pathJoin(markerPath, incompleteFile)
-	}
-
-	walker := lookupTreeWalk(layer, listParams{minioMetaBucket, recursive, markerPath, prefixPath})
+// listMetaBucketMultipart - list all objects at a given prefix inside minioMetaBucket.
+func (fs fsObjects) listMetaBucketMultipart(prefixPath string, markerPath string, recursive bool, maxKeys int) (fileInfos []FileInfo, eof bool, err error) {
+	walker := fs.lookupTreeWalk(listParams{minioMetaBucket, recursive, markerPath, prefixPath})
 	if walker == nil {
-		walker = startTreeWalk(layer, minioMetaBucket, prefixPath, markerPath, recursive)
+		walker = fs.startTreeWalk(minioMetaBucket, prefixPath, markerPath, recursive)
 	}
 
 	// newMaxKeys tracks the size of entries which are going to be
@@ -357,7 +132,6 @@ func listMetaBucketMultipartFiles(layer ObjectLayer, prefixPath string, markerPa
 
 	// Following loop gathers and filters out special files inside
 	// minio meta volume.
-outerLoop:
 	for {
 		walkResult, ok := <-walker.ch
 		if !ok {
@@ -373,47 +147,41 @@ outerLoop:
 			}
 			return nil, false, toObjectErr(walkResult.err, minioMetaBucket, prefixPath)
 		}
-		fi := walkResult.fileInfo
-		var entries []string
-		if fi.Mode.IsDir() {
+		fileInfo := walkResult.fileInfo
+		var uploads []uploadInfo
+		if fileInfo.Mode.IsDir() {
 			// List all the entries if fi.Name is a leaf directory, if
 			// fi.Name is not a leaf directory then the resulting
 			// entries are empty.
-			entries, err = listLeafEntries(storage, fi.Name)
+			uploads, err = fs.listUploadsInfo(fileInfo.Name)
 			if err != nil {
 				return nil, false, err
 			}
 		}
-		if len(entries) > 0 {
-			// We reach here for non-recursive case and a leaf entry.
-			sort.Strings(entries)
-			for _, entry := range entries {
-				var fileInfo FileInfo
-				incompleteUploadFile := path.Join(fi.Name, entry, incompleteFile)
-				fileInfo, err = storage.StatFile(minioMetaBucket, incompleteUploadFile)
-				if err != nil {
-					return nil, false, err
-				}
-				fileInfo.Name = path.Join(fi.Name, entry)
-				fileInfos = append(fileInfos, fileInfo)
+		if len(uploads) > 0 {
+			for _, upload := range uploads {
+				fileInfos = append(fileInfos, FileInfo{
+					Name:    path.Join(fileInfo.Name, upload.UploadID),
+					ModTime: upload.Initiated,
+				})
 				newMaxKeys++
 				// If we have reached the maxKeys, it means we have listed
 				// everything that was requested.
 				if newMaxKeys == maxKeys {
-					break outerLoop
+					break
 				}
 			}
 		} else {
 			// We reach here for a non-recursive case non-leaf entry
 			// OR recursive case with fi.Name.
-			if !fi.Mode.IsDir() { // Do not skip non-recursive case directory entries.
+			if !fileInfo.Mode.IsDir() { // Do not skip non-recursive case directory entries.
 				// Validate if 'fi.Name' is incomplete multipart.
-				if !strings.HasSuffix(fi.Name, incompleteFile) {
+				if !strings.HasSuffix(fileInfo.Name, fsMetaJSONFile) {
 					continue
 				}
-				fi.Name = path.Dir(fi.Name)
+				fileInfo.Name = path.Dir(fileInfo.Name)
 			}
-			fileInfos = append(fileInfos, fi)
+			fileInfos = append(fileInfos, fileInfo)
 			newMaxKeys++
 			// If we have reached the maxKeys, it means we have listed
 			// everything that was requested.
@@ -428,34 +196,27 @@ outerLoop:
 		// can continue from where it left off for the next list request.
 		lastFileInfo := fileInfos[len(fileInfos)-1]
 		markerPath = lastFileInfo.Name
-		saveTreeWalk(layer, listParams{minioMetaBucket, recursive, markerPath, prefixPath}, walker)
+		fs.saveTreeWalk(listParams{minioMetaBucket, recursive, markerPath, prefixPath}, walker)
 	}
+
 	// Return entries here.
 	return fileInfos, eof, nil
 }
 
 // FIXME: Currently the code sorts based on keyName/upload-id which is
-// in correct based on the S3 specs. According to s3 specs we are
+// not correct based on the S3 specs. According to s3 specs we are
 // supposed to only lexically sort keyNames and then for keyNames with
 // multiple upload ids should be sorted based on the initiated time.
 // Currently this case is not handled.
 
-// listMultipartUploadsCommon - lists all multipart uploads, common
-// function for both object layers.
-func listMultipartUploadsCommon(layer ObjectLayer, bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
-	var storage StorageAPI
-	switch l := layer.(type) {
-	case xlObjects:
-		storage = l.storage
-	case fsObjects:
-		storage = l.storage
-	}
+// listMultipartUploadsCommon - lists all multipart uploads, common function for both object layers.
+func (fs fsObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
 	result := ListMultipartsInfo{}
 	// Verify if bucket is valid.
 	if !IsValidBucketName(bucket) {
 		return ListMultipartsInfo{}, BucketNameInvalid{Bucket: bucket}
 	}
-	if !isBucketExist(storage, bucket) {
+	if !fs.isBucketExist(bucket) {
 		return ListMultipartsInfo{}, BucketNotFound{Bucket: bucket}
 	}
 	if !IsValidObjectPrefix(prefix) {
@@ -514,27 +275,27 @@ func listMultipartUploadsCommon(layer ObjectLayer, bucket, prefix, keyMarker, up
 	}
 
 	// List all the multipart files at prefixPath, starting with marker keyMarkerPath.
-	fileInfos, eof, err := listMetaBucketMultipartFiles(layer, multipartPrefixPath, multipartMarkerPath, recursive, maxUploads)
+	fileInfos, eof, err := fs.listMetaBucketMultipart(multipartPrefixPath, multipartMarkerPath, recursive, maxUploads)
 	if err != nil {
 		return ListMultipartsInfo{}, err
 	}
 
 	// Loop through all the received files fill in the multiparts result.
-	for _, fi := range fileInfos {
+	for _, fileInfo := range fileInfos {
 		var objectName string
 		var uploadID string
-		if fi.Mode.IsDir() {
+		if fileInfo.Mode.IsDir() {
 			// All directory entries are common prefixes.
 			uploadID = "" // Upload ids are empty for CommonPrefixes.
-			objectName = strings.TrimPrefix(fi.Name, retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			objectName = strings.TrimPrefix(fileInfo.Name, retainSlash(pathJoin(mpartMetaPrefix, bucket)))
 			result.CommonPrefixes = append(result.CommonPrefixes, objectName)
 		} else {
-			uploadID = path.Base(fi.Name)
-			objectName = strings.TrimPrefix(path.Dir(fi.Name), retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			uploadID = path.Base(fileInfo.Name)
+			objectName = strings.TrimPrefix(path.Dir(fileInfo.Name), retainSlash(pathJoin(mpartMetaPrefix, bucket)))
 			result.Uploads = append(result.Uploads, uploadMetadata{
 				Object:    objectName,
 				UploadID:  uploadID,
-				Initiated: fi.ModTime,
+				Initiated: fileInfo.ModTime,
 			})
 		}
 		result.NextKeyMarker = objectName
@@ -548,51 +309,165 @@ func listMultipartUploadsCommon(layer ObjectLayer, bucket, prefix, keyMarker, up
 	return result, nil
 }
 
-// ListObjectParts - list object parts, common function across both object layers.
-func listObjectPartsCommon(storage StorageAPI, bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
+// ListMultipartUploads - list multipart uploads.
+func (fs fsObjects) ListMultipartUploads(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
+	return fs.listMultipartUploadsCommon(bucket, prefix, keyMarker, uploadIDMarker, delimiter, maxUploads)
+}
+
+// NewMultipartUpload - initialize a new multipart upload, returns a unique id.
+func (fs fsObjects) NewMultipartUpload(bucket, object string, meta map[string]string) (string, error) {
+	meta = make(map[string]string) // Reset the meta value, we are not going to save headers for fs.
+	return fs.newMultipartUploadCommon(bucket, object, meta)
+}
+
+// putObjectPartCommon - put object part.
+func (fs fsObjects) putObjectPartCommon(bucket string, object string, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return "", BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify whether the bucket exists.
+	if !fs.isBucketExist(bucket) {
+		return "", BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return "", ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	if !fs.isUploadIDExists(bucket, object, uploadID) {
+		return "", InvalidUploadID{UploadID: uploadID}
+	}
+	// Hold read lock on the uploadID so that no one aborts it.
+	nsMutex.RLock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	defer nsMutex.RUnlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+
+	// Hold write lock on the part so that there is no parallel upload on the part.
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID, strconv.Itoa(partID)))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID, strconv.Itoa(partID)))
+
+	partSuffix := fmt.Sprintf("object%d", partID)
+	tmpPartPath := path.Join(tmpMetaPrefix, bucket, object, uploadID, partSuffix)
+	fileWriter, err := fs.storage.CreateFile(minioMetaBucket, tmpPartPath)
+	if err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Initialize md5 writer.
+	md5Writer := md5.New()
+
+	// Instantiate a new multi writer.
+	multiWriter := io.MultiWriter(md5Writer, fileWriter)
+
+	// Instantiate checksum hashers and create a multiwriter.
+	if size > 0 {
+		if _, err = io.CopyN(multiWriter, data, size); err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", toObjectErr(err, bucket, object)
+		}
+		// Reader shouldn't have more data what mentioned in size argument.
+		// reading one more byte from the reader to validate it.
+		// expected to fail, success validates existence of more data in the reader.
+		if _, err = io.CopyN(ioutil.Discard, data, 1); err == nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", UnExpectedDataSize{Size: int(size)}
+		}
+	} else {
+		var n int64
+		if n, err = io.Copy(multiWriter, data); err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", toObjectErr(err, bucket, object)
+		}
+		size = n
+	}
+
+	newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
+	if md5Hex != "" {
+		if newMD5Hex != md5Hex {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", BadDigest{md5Hex, newMD5Hex}
+		}
+	}
+	err = fileWriter.Close()
+	if err != nil {
+		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+			return "", toObjectErr(clErr, bucket, object)
+		}
+		return "", err
+	}
+
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	fsMeta, err := fs.readFSMetadata(minioMetaBucket, uploadIDPath)
+	if err != nil {
+		return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
+	}
+	fsMeta.AddObjectPart(partSuffix, newMD5Hex, size)
+
+	partPath := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffix)
+	err = fs.storage.RenameFile(minioMetaBucket, tmpPartPath, minioMetaBucket, partPath)
+	if err != nil {
+		if dErr := fs.storage.DeleteFile(minioMetaBucket, tmpPartPath); dErr != nil {
+			return "", toObjectErr(dErr, minioMetaBucket, tmpPartPath)
+		}
+		return "", toObjectErr(err, minioMetaBucket, partPath)
+	}
+	if err = fs.writeFSMetadata(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID), fsMeta); err != nil {
+		return "", toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
+	}
+	return newMD5Hex, nil
+}
+
+// PutObjectPart - writes the multipart upload chunks.
+func (fs fsObjects) PutObjectPart(bucket, object, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
+	return fs.putObjectPartCommon(bucket, object, uploadID, partID, size, data, md5Hex)
+}
+
+func (fs fsObjects) listObjectPartsCommon(bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
 	// Verify if bucket is valid.
 	if !IsValidBucketName(bucket) {
 		return ListPartsInfo{}, BucketNameInvalid{Bucket: bucket}
 	}
 	// Verify whether the bucket exists.
-	if !isBucketExist(storage, bucket) {
+	if !fs.isBucketExist(bucket) {
 		return ListPartsInfo{}, BucketNotFound{Bucket: bucket}
 	}
 	if !IsValidObjectName(object) {
 		return ListPartsInfo{}, ObjectNameInvalid{Bucket: bucket, Object: object}
 	}
-	if !isUploadIDExists(storage, bucket, object, uploadID) {
+	if !fs.isUploadIDExists(bucket, object, uploadID) {
 		return ListPartsInfo{}, InvalidUploadID{UploadID: uploadID}
 	}
 	// Hold lock so that there is no competing abort-multipart-upload or complete-multipart-upload.
 	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
 	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
 	result := ListPartsInfo{}
-	entries, err := storage.ListDir(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
+
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	fsMeta, err := fs.readFSMetadata(minioMetaBucket, uploadIDPath)
 	if err != nil {
-		return result, err
-	}
-	sort.Strings(entries)
-	var newEntries []string
-	for _, entry := range entries {
-		newEntries = append(newEntries, path.Base(entry))
+		return ListPartsInfo{}, toObjectErr(err, minioMetaBucket, uploadIDPath)
 	}
-	idx := sort.SearchStrings(newEntries, fmt.Sprintf("%.5d.", partNumberMarker+1))
-	newEntries = newEntries[idx:]
+	// Only parts with higher part numbers will be listed.
+	parts := fsMeta.Parts[partNumberMarker:]
 	count := maxParts
-	for _, entry := range newEntries {
-		fi, err := storage.StatFile(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID, entry))
-		splitEntry := strings.SplitN(entry, ".", 2)
-		partStr := splitEntry[0]
-		etagStr := splitEntry[1]
-		partNum, err := strconv.Atoi(partStr)
+	for i, part := range parts {
+		var fi FileInfo
+		partNamePath := path.Join(mpartMetaPrefix, bucket, object, uploadID, part.Name)
+		fi, err = fs.storage.StatFile(minioMetaBucket, partNamePath)
 		if err != nil {
-			return ListPartsInfo{}, err
+			return ListPartsInfo{}, toObjectErr(err, minioMetaBucket, partNamePath)
 		}
+		partNum := i + partNumberMarker + 1
 		result.Parts = append(result.Parts, partInfo{
 			PartNumber:   partNum,
+			ETag:         part.ETag,
 			LastModified: fi.ModTime,
-			ETag:         etagStr,
 			Size:         fi.Size,
 		})
 		count--
@@ -601,7 +476,7 @@ func listObjectPartsCommon(storage StorageAPI, bucket, object, uploadID string,
 		}
 	}
 	// If listed entries are more than maxParts, we set IsTruncated as true.
-	if len(newEntries) > len(result.Parts) {
+	if len(parts) > len(result.Parts) {
 		result.IsTruncated = true
 		// Make sure to fill next part number marker if IsTruncated is
 		// true for subsequent listing.
@@ -615,16 +490,170 @@ func listObjectPartsCommon(storage StorageAPI, bucket, object, uploadID string,
 	return result, nil
 }
 
+func (fs fsObjects) ListObjectParts(bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
+	return fs.listObjectPartsCommon(bucket, object, uploadID, partNumberMarker, maxParts)
+}
+
 // isUploadIDExists - verify if a given uploadID exists and is valid.
-func isUploadIDExists(storage StorageAPI, bucket, object, uploadID string) bool {
-	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID, incompleteFile)
-	st, err := storage.StatFile(minioMetaBucket, uploadIDPath)
+func (fs fsObjects) isUploadIDExists(bucket, object, uploadID string) bool {
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	_, err := fs.storage.StatFile(minioMetaBucket, path.Join(uploadIDPath, fsMetaJSONFile))
 	if err != nil {
 		if err == errFileNotFound {
 			return false
 		}
-		errorIf(err, "Stat failed on "+minioMetaBucket+"/"+uploadIDPath+".")
+		errorIf(err, "Unable to access upload id"+uploadIDPath)
 		return false
 	}
-	return st.Mode.IsRegular()
+	return true
+}
+
+func (fs fsObjects) CompleteMultipartUpload(bucket string, object string, uploadID string, parts []completePart) (string, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return "", BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify whether the bucket exists.
+	if !fs.isBucketExist(bucket) {
+		return "", BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return "", ObjectNameInvalid{
+			Bucket: bucket,
+			Object: object,
+		}
+	}
+	if !fs.isUploadIDExists(bucket, object, uploadID) {
+		return "", InvalidUploadID{UploadID: uploadID}
+	}
+
+	// Calculate s3 compatible md5sum for complete multipart.
+	s3MD5, err := completeMultipartMD5(parts...)
+	if err != nil {
+		return "", err
+	}
+
+	tempObj := path.Join(tmpMetaPrefix, bucket, object, uploadID, "object1")
+	fileWriter, err := fs.storage.CreateFile(minioMetaBucket, tempObj)
+	if err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Loop through all parts, validate them and then commit to disk.
+	for i, part := range parts {
+		// Construct part suffix.
+		partSuffix := fmt.Sprintf("object%d", part.PartNumber)
+		multipartPartFile := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffix)
+		var fi FileInfo
+		fi, err = fs.storage.StatFile(minioMetaBucket, multipartPartFile)
+		if err != nil {
+			if err == errFileNotFound {
+				return "", InvalidPart{}
+			}
+			return "", err
+		}
+		// All parts except the last part has to be atleast 5MB.
+		if (i < len(parts)-1) && !isMinAllowedPartSize(fi.Size) {
+			return "", PartTooSmall{}
+		}
+		var fileReader io.ReadCloser
+		fileReader, err = fs.storage.ReadFile(minioMetaBucket, multipartPartFile, 0)
+		if err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", clErr
+			}
+			if err == errFileNotFound {
+				return "", InvalidPart{}
+			}
+			return "", err
+		}
+		_, err = io.Copy(fileWriter, fileReader)
+		if err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", clErr
+			}
+			return "", err
+		}
+		err = fileReader.Close()
+		if err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", clErr
+			}
+			return "", err
+		}
+	}
+
+	err = fileWriter.Close()
+	if err != nil {
+		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+			return "", clErr
+		}
+		return "", err
+	}
+
+	// Rename the file back to original location, if not delete the temporary object.
+	err = fs.storage.RenameFile(minioMetaBucket, tempObj, bucket, object)
+	if err != nil {
+		if dErr := fs.storage.DeleteFile(minioMetaBucket, tempObj); dErr != nil {
+			return "", toObjectErr(dErr, minioMetaBucket, tempObj)
+		}
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Cleanup all the parts if everything else has been safely committed.
+	if err = cleanupUploadedParts(bucket, object, uploadID, fs.storage); err != nil {
+		return "", err
+	}
+
+	// Return md5sum.
+	return s3MD5, nil
+}
+
+// abortMultipartUploadCommon - aborts a multipart upload, common
+// function used by both object layers.
+func (fs fsObjects) abortMultipartUploadCommon(bucket, object, uploadID string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	if !fs.isBucketExist(bucket) {
+		return BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	if !fs.isUploadIDExists(bucket, object, uploadID) {
+		return InvalidUploadID{UploadID: uploadID}
+	}
+
+	// Hold lock so that there is no competing complete-multipart-upload or put-object-part.
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+
+	// Cleanup all uploaded parts.
+	if err := cleanupUploadedParts(bucket, object, uploadID, fs.storage); err != nil {
+		return err
+	}
+
+	// Validate if there are other incomplete upload-id's present for
+	// the object, if yes do not attempt to delete 'uploads.json'.
+	uploadIDs, err := getUploadIDs(bucket, object, fs.storage)
+	if err == nil {
+		uploadIDIdx := uploadIDs.SearchUploadID(uploadID)
+		if uploadIDIdx != -1 {
+			uploadIDs.Uploads = append(uploadIDs.Uploads[:uploadIDIdx], uploadIDs.Uploads[uploadIDIdx+1:]...)
+		}
+		if len(uploadIDs.Uploads) > 0 {
+			return nil
+		}
+	}
+	if err = fs.storage.DeleteFile(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)); err != nil {
+		return toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
+	}
+	return nil
+}
+
+// AbortMultipartUpload - aborts a multipart upload.
+func (fs fsObjects) AbortMultipartUpload(bucket, object, uploadID string) error {
+	return fs.abortMultipartUploadCommon(bucket, object, uploadID)
 }

fs-v1.go

@@ -21,6 +21,7 @@ import (
 	"encoding/hex"
 	"io"
 	"path/filepath"
+	"sort"
 	"strings"
 	"sync"
 
@@ -30,7 +31,7 @@ import (
 // fsObjects - Implements fs object layer.
 type fsObjects struct {
 	storage            StorageAPI
-	listObjectMap      map[listParams][]*treeWalker
+	listObjectMap      map[listParams][]*treeWalkerFS
 	listObjectMapMutex *sync.Mutex
 }
 
@@ -59,7 +60,7 @@ func newFSObjects(exportPath string) (ObjectLayer, error) {
 	// Return successfully initialized object layer.
 	return fsObjects{
 		storage:            storage,
-		listObjectMap:      make(map[listParams][]*treeWalker),
+		listObjectMap:      make(map[listParams][]*treeWalkerFS),
 		listObjectMapMutex: &sync.Mutex{},
 	}, nil
 }
@@ -68,22 +69,68 @@ func newFSObjects(exportPath string) (ObjectLayer, error) {
 
 // MakeBucket - make a bucket.
 func (fs fsObjects) MakeBucket(bucket string) error {
-	return makeBucket(fs.storage, bucket)
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	if err := fs.storage.MakeVol(bucket); err != nil {
+		return toObjectErr(err, bucket)
+	}
+	return nil
 }
 
 // GetBucketInfo - get bucket info.
 func (fs fsObjects) GetBucketInfo(bucket string) (BucketInfo, error) {
-	return getBucketInfo(fs.storage, bucket)
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	vi, err := fs.storage.StatVol(bucket)
+	if err != nil {
+		return BucketInfo{}, toObjectErr(err, bucket)
+	}
+	return BucketInfo{
+		Name:    bucket,
+		Created: vi.Created,
+		Total:   vi.Total,
+		Free:    vi.Free,
+	}, nil
 }
 
 // ListBuckets - list buckets.
 func (fs fsObjects) ListBuckets() ([]BucketInfo, error) {
-	return listBuckets(fs.storage)
+	var bucketInfos []BucketInfo
+	vols, err := fs.storage.ListVols()
+	if err != nil {
+		return nil, toObjectErr(err)
+	}
+	for _, vol := range vols {
+		// StorageAPI can send volume names which are incompatible
+		// with buckets, handle it and skip them.
+		if !IsValidBucketName(vol.Name) {
+			continue
+		}
+		bucketInfos = append(bucketInfos, BucketInfo{
+			Name:    vol.Name,
+			Created: vol.Created,
+			Total:   vol.Total,
+			Free:    vol.Free,
+		})
+	}
+	sort.Sort(byBucketName(bucketInfos))
+	return bucketInfos, nil
 }
 
 // DeleteBucket - delete a bucket.
 func (fs fsObjects) DeleteBucket(bucket string) error {
-	return deleteBucket(fs.storage, bucket)
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	if err := fs.storage.DeleteVol(bucket); err != nil {
+		return toObjectErr(err, bucket)
+	}
+	return nil
 }
 
 /// Object Operations
@@ -218,7 +265,121 @@ func (fs fsObjects) DeleteObject(bucket, object string) error {
 	return nil
 }
 
+// Checks whether bucket exists.
+func isBucketExist(storage StorageAPI, bucketName string) bool {
+	// Check whether bucket exists.
+	_, err := storage.StatVol(bucketName)
+	if err != nil {
+		if err == errVolumeNotFound {
+			return false
+		}
+		errorIf(err, "Stat failed on bucket "+bucketName+".")
+		return false
+	}
+	return true
+}
+
+func (fs fsObjects) listObjectsFS(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return ListObjectsInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify if bucket exists.
+	if !isBucketExist(fs.storage, bucket) {
+		return ListObjectsInfo{}, BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectPrefix(prefix) {
+		return ListObjectsInfo{}, ObjectNameInvalid{Bucket: bucket, Object: prefix}
+	}
+	// Verify if delimiter is anything other than '/', which we do not support.
+	if delimiter != "" && delimiter != slashSeparator {
+		return ListObjectsInfo{}, UnsupportedDelimiter{
+			Delimiter: delimiter,
+		}
+	}
+	// Verify if marker has prefix.
+	if marker != "" {
+		if !strings.HasPrefix(marker, prefix) {
+			return ListObjectsInfo{}, InvalidMarkerPrefixCombination{
+				Marker: marker,
+				Prefix: prefix,
+			}
+		}
+	}
+
+	// With max keys of zero we have reached eof, return right here.
+	if maxKeys == 0 {
+		return ListObjectsInfo{}, nil
+	}
+
+	// Over flowing count - reset to maxObjectList.
+	if maxKeys < 0 || maxKeys > maxObjectList {
+		maxKeys = maxObjectList
+	}
+
+	// Default is recursive, if delimiter is set then list non recursive.
+	recursive := true
+	if delimiter == slashSeparator {
+		recursive = false
+	}
+
+	walker := fs.lookupTreeWalk(listParams{bucket, recursive, marker, prefix})
+	if walker == nil {
+		walker = fs.startTreeWalk(bucket, prefix, marker, recursive)
+	}
+	var fileInfos []FileInfo
+	var eof bool
+	var nextMarker string
+	for i := 0; i < maxKeys; {
+		walkResult, ok := <-walker.ch
+		if !ok {
+			// Closed channel.
+			eof = true
+			break
+		}
+		// For any walk error return right away.
+		if walkResult.err != nil {
+			// File not found is a valid case.
+			if walkResult.err == errFileNotFound {
+				return ListObjectsInfo{}, nil
+			}
+			return ListObjectsInfo{}, toObjectErr(walkResult.err, bucket, prefix)
+		}
+		fileInfo := walkResult.fileInfo
+		nextMarker = fileInfo.Name
+		fileInfos = append(fileInfos, fileInfo)
+		if walkResult.end {
+			eof = true
+			break
+		}
+		i++
+	}
+	params := listParams{bucket, recursive, nextMarker, prefix}
+	if !eof {
+		fs.saveTreeWalk(params, walker)
+	}
+
+	result := ListObjectsInfo{IsTruncated: !eof}
+	for _, fileInfo := range fileInfos {
+		// With delimiter set we fill in NextMarker and Prefixes.
+		if delimiter == slashSeparator {
+			result.NextMarker = fileInfo.Name
+			if fileInfo.Mode.IsDir() {
+				result.Prefixes = append(result.Prefixes, fileInfo.Name)
+				continue
+			}
+		}
+		result.Objects = append(result.Objects, ObjectInfo{
+			Name:    fileInfo.Name,
+			ModTime: fileInfo.ModTime,
+			Size:    fileInfo.Size,
+			IsDir:   false,
+		})
+	}
+	return result, nil
+}
+
 // ListObjects - list all objects.
 func (fs fsObjects) ListObjects(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
-	return listObjectsCommon(fs, bucket, prefix, marker, delimiter, maxKeys)
+	return fs.listObjectsFS(bucket, prefix, marker, delimiter, maxKeys)
 }

object-common.go

@@ -16,10 +16,7 @@
 
 package main
 
-import (
-	"sort"
-	"strings"
-)
+import "strings"
 
 // Common initialization needed for both object layers.
 func initObjectLayer(storageDisks ...StorageAPI) error {
@@ -69,192 +66,3 @@ func cleanupDir(storage StorageAPI, volume, dirPath string) error {
 	}
 	return delFunc(retainSlash(pathJoin(dirPath)))
 }
-
-/// Common object layer functions.
-
-// makeBucket - create a bucket, is a common function for both object layers.
-func makeBucket(storage StorageAPI, bucket string) error {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return BucketNameInvalid{Bucket: bucket}
-	}
-	if err := storage.MakeVol(bucket); err != nil {
-		return toObjectErr(err, bucket)
-	}
-	return nil
-}
-
-// getBucketInfo - fetch bucket info, is a common function for both object layers.
-func getBucketInfo(storage StorageAPI, bucket string) (BucketInfo, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return BucketInfo{}, BucketNameInvalid{Bucket: bucket}
-	}
-	vi, err := storage.StatVol(bucket)
-	if err != nil {
-		return BucketInfo{}, toObjectErr(err, bucket)
-	}
-	return BucketInfo{
-		Name:    bucket,
-		Created: vi.Created,
-		Total:   vi.Total,
-		Free:    vi.Free,
-	}, nil
-}
-
-// listBuckets - list all buckets, is a common function for both object layers.
-func listBuckets(storage StorageAPI) ([]BucketInfo, error) {
-	var bucketInfos []BucketInfo
-	vols, err := storage.ListVols()
-	if err != nil {
-		return nil, toObjectErr(err)
-	}
-	for _, vol := range vols {
-		// StorageAPI can send volume names which are incompatible
-		// with buckets, handle it and skip them.
-		if !IsValidBucketName(vol.Name) {
-			continue
-		}
-		bucketInfos = append(bucketInfos, BucketInfo{
-			Name:    vol.Name,
-			Created: vol.Created,
-			Total:   vol.Total,
-			Free:    vol.Free,
-		})
-	}
-	sort.Sort(byBucketName(bucketInfos))
-	return bucketInfos, nil
-}
-
-// deleteBucket - deletes a bucket, is a common function for both the layers.
-func deleteBucket(storage StorageAPI, bucket string) error {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return BucketNameInvalid{Bucket: bucket}
-	}
-	if err := storage.DeleteVol(bucket); err != nil {
-		return toObjectErr(err, bucket)
-	}
-	return nil
-}
-
-func listObjectsCommon(layer ObjectLayer, bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
-	var storage StorageAPI
-	switch l := layer.(type) {
-	case xlObjects:
-		storage = l.storage
-	case fsObjects:
-		storage = l.storage
-	}
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return ListObjectsInfo{}, BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify if bucket exists.
-	if !isBucketExist(storage, bucket) {
-		return ListObjectsInfo{}, BucketNotFound{Bucket: bucket}
-	}
-	if !IsValidObjectPrefix(prefix) {
-		return ListObjectsInfo{}, ObjectNameInvalid{Bucket: bucket, Object: prefix}
-	}
-	// Verify if delimiter is anything other than '/', which we do not support.
-	if delimiter != "" && delimiter != slashSeparator {
-		return ListObjectsInfo{}, UnsupportedDelimiter{
-			Delimiter: delimiter,
-		}
-	}
-	// Verify if marker has prefix.
-	if marker != "" {
-		if !strings.HasPrefix(marker, prefix) {
-			return ListObjectsInfo{}, InvalidMarkerPrefixCombination{
-				Marker: marker,
-				Prefix: prefix,
-			}
-		}
-	}
-
-	// With max keys of zero we have reached eof, return right here.
-	if maxKeys == 0 {
-		return ListObjectsInfo{}, nil
-	}
-
-	// Over flowing count - reset to maxObjectList.
-	if maxKeys < 0 || maxKeys > maxObjectList {
-		maxKeys = maxObjectList
-	}
-
-	// Default is recursive, if delimiter is set then list non recursive.
-	recursive := true
-	if delimiter == slashSeparator {
-		recursive = false
-	}
-
-	walker := lookupTreeWalk(layer, listParams{bucket, recursive, marker, prefix})
-	if walker == nil {
-		walker = startTreeWalk(layer, bucket, prefix, marker, recursive)
-	}
-	var fileInfos []FileInfo
-	var eof bool
-	var nextMarker string
-	for i := 0; i < maxKeys; {
-		walkResult, ok := <-walker.ch
-		if !ok {
-			// Closed channel.
-			eof = true
-			break
-		}
-		// For any walk error return right away.
-		if walkResult.err != nil {
-			// File not found is a valid case.
-			if walkResult.err == errFileNotFound {
-				return ListObjectsInfo{}, nil
-			}
-			return ListObjectsInfo{}, toObjectErr(walkResult.err, bucket, prefix)
-		}
-		fileInfo := walkResult.fileInfo
-		nextMarker = fileInfo.Name
-		fileInfos = append(fileInfos, fileInfo)
-		if walkResult.end {
-			eof = true
-			break
-		}
-		i++
-	}
-	params := listParams{bucket, recursive, nextMarker, prefix}
-	if !eof {
-		saveTreeWalk(layer, params, walker)
-	}
-
-	result := ListObjectsInfo{IsTruncated: !eof}
-	for _, fileInfo := range fileInfos {
-		// With delimiter set we fill in NextMarker and Prefixes.
-		if delimiter == slashSeparator {
-			result.NextMarker = fileInfo.Name
-			if fileInfo.Mode.IsDir() {
-				result.Prefixes = append(result.Prefixes, fileInfo.Name)
-				continue
-			}
-		}
-		result.Objects = append(result.Objects, ObjectInfo{
-			Name:    fileInfo.Name,
-			ModTime: fileInfo.ModTime,
-			Size:    fileInfo.Size,
-			IsDir:   false,
-		})
-	}
-	return result, nil
-}
-
-// checks whether bucket exists.
-func isBucketExist(storage StorageAPI, bucketName string) bool {
-	// Check whether bucket exists.
-	_, err := storage.StatVol(bucketName)
-	if err != nil {
-		if err == errVolumeNotFound {
-			return false
-		}
-		errorIf(err, "Stat failed on bucket "+bucketName+".")
-		return false
-	}
-	return true
-}

object-utils.go

@@ -28,6 +28,7 @@ import (
 	"unicode/utf8"
 
 	"github.com/minio/minio/pkg/safe"
+	"github.com/skyrings/skyring-common/tools/uuid"
 )
 
 const (
@@ -123,6 +124,20 @@ func pathJoin(elem ...string) string {
 	return path.Join(elem...) + trailingSlash
 }
 
+// getUUID() - get a unique uuid.
+func getUUID() (uuidStr string) {
+	for {
+		uuid, err := uuid.New()
+		if err != nil {
+			errorIf(err, "Unable to initialize uuid")
+			continue
+		}
+		uuidStr = uuid.String()
+		break
+	}
+	return uuidStr
+}
+
 // Create an s3 compatible MD5sum for complete multipart transaction.
 func completeMultipartMD5(parts ...completePart) (string, error) {
 	var finalMD5Bytes []byte

object_api_suite_test.go

@@ -27,8 +27,6 @@ import (
 	"gopkg.in/check.v1"
 )
 
-// TODO - enable all the commented tests.
-
 // APITestSuite - collection of API tests.
 func APITestSuite(c *check.C, create func() ObjectLayer) {
 	testMakeBucket(c, create)

posix.go

@@ -333,6 +333,8 @@ func (s fsStorage) ReadFile(volume string, path string, offset int64) (readClose
 			return nil, errFileNotFound
 		} else if os.IsPermission(err) {
 			return nil, errFileAccessDenied
+		} else if strings.Contains(err.Error(), "not a directory") {
+			return nil, errFileNotFound
 		}
 		return nil, err
 	}
@@ -425,7 +427,6 @@ func (s fsStorage) StatFile(volume, path string) (file FileInfo, err error) {
 		// Return all errors here.
 		return FileInfo{}, err
 	}
-
 	// If its a directory its not a regular file.
 	if st.Mode().IsDir() {
 		return FileInfo{}, errFileNotFound

test-utils_test.go

@@ -44,6 +44,10 @@ func ExecObjectLayerTest(t *testing.T, objTest func(obj ObjectLayer, instanceTyp
 			}
 			erasureDisks = append(erasureDisks, path)
 		}
+
+		// Initialize name space lock.
+		initNSLock()
+
 		objLayer, err := newXLObjects(erasureDisks)
 		if err != nil {
 			return nil, nil, err
@@ -59,6 +63,9 @@ func ExecObjectLayerTest(t *testing.T, objTest func(obj ObjectLayer, instanceTyp
 			return nil, "", err
 		}
 
+		// Initialize name space lock.
+		initNSLock()
+
 		// Create the obj.
 		objLayer, err := newFSObjects(fsDir)
 		if err != nil {
@@ -80,7 +87,7 @@ func ExecObjectLayerTest(t *testing.T, objTest func(obj ObjectLayer, instanceTyp
 	}
 	// Executing the object layer tests for single node setup.
 	objTest(objLayer, singleNodeTestStr, t)
-	initNSLock()
+
 	objLayer, fsDirs, err := getXLObjectLayer()
 	if err != nil {
 		t.Fatalf("Initialization of object layer failed for XL setup: %s", err.Error())

tree-walk-fs.go

@@ -21,49 +21,30 @@ import (
 	"path"
 	"sort"
 	"strings"
-	"sync"
 	"time"
 )
 
-// listParams - list object params used for list object map
-type listParams struct {
-	bucket    string
-	recursive bool
-	marker    string
-	prefix    string
+// Tree walk notify carries a channel which notifies tree walk
+// results, additionally it also carries information if treeWalk
+// should be timedOut.
+type treeWalkerFS struct {
+	ch       <-chan treeWalkResultFS
+	timedOut bool
 }
 
 // Tree walk result carries results of tree walking.
-type treeWalkResult struct {
+type treeWalkResultFS struct {
 	fileInfo FileInfo
 	err      error
 	end      bool
 }
 
-// Tree walk notify carries a channel which notifies tree walk
-// results, additionally it also carries information if treeWalk
-// should be timedOut.
-type treeWalker struct {
-	ch       <-chan treeWalkResult
-	timedOut bool
-}
-
 // treeWalk walks FS directory tree recursively pushing fileInfo into the channel as and when it encounters files.
-func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, send func(treeWalkResult) bool, count *int) bool {
+func (fs fsObjects) treeWalk(bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, send func(treeWalkResultFS) bool, count *int) bool {
 	// Example:
 	// if prefixDir="one/two/three/" and marker="four/five.txt" treeWalk is recursively
 	// called with prefixDir="one/two/three/four/" and marker="five.txt"
 
-	var isXL bool
-	var disk StorageAPI
-	switch l := layer.(type) {
-	case xlObjects:
-		isXL = true
-		disk = l.storage
-	case fsObjects:
-		disk = l.storage
-	}
-
 	// Convert entry to FileInfo
 	entryToFileInfo := func(entry string) (fileInfo FileInfo, err error) {
 		if strings.HasSuffix(entry, slashSeparator) {
@@ -73,26 +54,7 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 			fileInfo.Mode = os.ModeDir
 			return
 		}
-		if isXL && strings.HasSuffix(entry, multipartSuffix) {
-			// If the entry was detected as a multipart file we use
-			// getMultipartObjectInfo() to fill the FileInfo structure.
-			entry = strings.TrimSuffix(entry, multipartSuffix)
-			var info MultipartObjectInfo
-			info, err = getMultipartObjectInfo(disk, bucket, path.Join(prefixDir, entry))
-			if err != nil {
-				return
-			}
-			// Set the Mode to a "regular" file.
-			fileInfo.Mode = 0
-			// Trim the suffix that was temporarily added to indicate that this
-			// is a multipart file.
-			fileInfo.Name = path.Join(prefixDir, entry)
-			fileInfo.Size = info.Size
-			fileInfo.MD5Sum = info.MD5Sum
-			fileInfo.ModTime = info.ModTime
-			return
-		}
-		if fileInfo, err = disk.StatFile(bucket, path.Join(prefixDir, entry)); err != nil {
+		if fileInfo, err = fs.storage.StatFile(bucket, path.Join(prefixDir, entry)); err != nil {
 			return
 		}
 		// Object name needs to be full path.
@@ -110,9 +72,9 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 			markerBase = markerSplit[1]
 		}
 	}
-	entries, err := disk.ListDir(bucket, prefixDir)
+	entries, err := fs.storage.ListDir(bucket, prefixDir)
 	if err != nil {
-		send(treeWalkResult{err: err})
+		send(treeWalkResultFS{err: err})
 		return false
 	}
 
@@ -123,16 +85,7 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 			}
 		}
 	}
-	// For XL multipart files strip the trailing "/" and append ".minio.multipart" to the entry so that
-	// entryToFileInfo() can call StatFile for regular files or getMultipartObjectInfo() for multipart files.
-	for i, entry := range entries {
-		if isXL && strings.HasSuffix(entry, slashSeparator) {
-			if isMultipartObject(disk, bucket, path.Join(prefixDir, entry)) {
-				entries[i] = strings.TrimSuffix(entry, slashSeparator) + multipartSuffix
-			}
-		}
-	}
-	sort.Sort(byMultipartFiles(entries))
+	sort.Strings(entries)
 	// Skip the empty strings
 	for len(entries) > 0 && entries[0] == "" {
 		entries = entries[1:]
@@ -144,7 +97,7 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 	// If markerDir="four/" Search() returns the index of "four/" in the sorted
 	// entries list so we skip all the entries till "four/"
 	idx := sort.Search(len(entries), func(i int) bool {
-		return strings.TrimSuffix(entries[i], multipartSuffix) >= markerDir
+		return entries[i] >= markerDir
 	})
 	entries = entries[idx:]
 	*count += len(entries)
@@ -176,7 +129,7 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 			}
 			*count--
 			prefixMatch := "" // Valid only for first level treeWalk and empty for subdirectories.
-			if !treeWalk(layer, bucket, path.Join(prefixDir, entry), prefixMatch, markerArg, recursive, send, count) {
+			if !fs.treeWalk(bucket, path.Join(prefixDir, entry), prefixMatch, markerArg, recursive, send, count) {
 				return false
 			}
 			continue
@@ -188,7 +141,7 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 			// Ignore error and continue.
 			continue
 		}
-		if !send(treeWalkResult{fileInfo: fileInfo}) {
+		if !send(treeWalkResultFS{fileInfo: fileInfo}) {
 			return false
 		}
 	}
@@ -196,7 +149,7 @@ func treeWalk(layer ObjectLayer, bucket, prefixDir, entryPrefixMatch, marker str
 }
 
 // Initiate a new treeWalk in a goroutine.
-func startTreeWalk(layer ObjectLayer, bucket, prefix, marker string, recursive bool) *treeWalker {
+func (fs fsObjects) startTreeWalk(bucket, prefix, marker string, recursive bool) *treeWalkerFS {
 	// Example 1
 	// If prefix is "one/two/three/" and marker is "one/two/three/four/five.txt"
 	// treeWalk is called with prefixDir="one/two/three/" and marker="four/five.txt"
@@ -207,8 +160,8 @@ func startTreeWalk(layer ObjectLayer, bucket, prefix, marker string, recursive b
 	// treeWalk is called with prefixDir="one/two/" and marker="three/four/five.txt"
 	// and entryPrefixMatch="th"
 
-	ch := make(chan treeWalkResult, maxObjectList)
-	walkNotify := treeWalker{ch: ch}
+	ch := make(chan treeWalkResultFS, maxObjectList)
+	walkNotify := treeWalkerFS{ch: ch}
 	entryPrefixMatch := prefix
 	prefixDir := ""
 	lastIndex := strings.LastIndex(prefix, slashSeparator)
@@ -220,7 +173,7 @@ func startTreeWalk(layer ObjectLayer, bucket, prefix, marker string, recursive b
 	marker = strings.TrimPrefix(marker, prefixDir)
 	go func() {
 		defer close(ch)
-		send := func(walkResult treeWalkResult) bool {
+		send := func(walkResult treeWalkResultFS) bool {
 			if count == 0 {
 				walkResult.end = true
 			}
@@ -233,61 +186,41 @@ func startTreeWalk(layer ObjectLayer, bucket, prefix, marker string, recursive b
 				return false
 			}
 		}
-		treeWalk(layer, bucket, prefixDir, entryPrefixMatch, marker, recursive, send, &count)
+		fs.treeWalk(bucket, prefixDir, entryPrefixMatch, marker, recursive, send, &count)
 	}()
 	return &walkNotify
 }
 
 // Save the goroutine reference in the map
-func saveTreeWalk(layer ObjectLayer, params listParams, walker *treeWalker) {
-	var listObjectMap map[listParams][]*treeWalker
-	var listObjectMapMutex *sync.Mutex
-	switch l := layer.(type) {
-	case xlObjects:
-		listObjectMap = l.listObjectMap
-		listObjectMapMutex = l.listObjectMapMutex
-	case fsObjects:
-		listObjectMap = l.listObjectMap
-		listObjectMapMutex = l.listObjectMapMutex
-	}
-	listObjectMapMutex.Lock()
-	defer listObjectMapMutex.Unlock()
+func (fs fsObjects) saveTreeWalk(params listParams, walker *treeWalkerFS) {
+	fs.listObjectMapMutex.Lock()
+	defer fs.listObjectMapMutex.Unlock()
 
-	walkers, _ := listObjectMap[params]
+	walkers, _ := fs.listObjectMap[params]
 	walkers = append(walkers, walker)
 
-	listObjectMap[params] = walkers
+	fs.listObjectMap[params] = walkers
 }
 
 // Lookup the goroutine reference from map
-func lookupTreeWalk(layer ObjectLayer, params listParams) *treeWalker {
-	var listObjectMap map[listParams][]*treeWalker
-	var listObjectMapMutex *sync.Mutex
-	switch l := layer.(type) {
-	case xlObjects:
-		listObjectMap = l.listObjectMap
-		listObjectMapMutex = l.listObjectMapMutex
-	case fsObjects:
-		listObjectMap = l.listObjectMap
-		listObjectMapMutex = l.listObjectMapMutex
-	}
-	listObjectMapMutex.Lock()
-	defer listObjectMapMutex.Unlock()
+func (fs fsObjects) lookupTreeWalk(params listParams) *treeWalkerFS {
+	fs.listObjectMapMutex.Lock()
+	defer fs.listObjectMapMutex.Unlock()
 
-	if walkChs, ok := listObjectMap[params]; ok {
+	if walkChs, ok := fs.listObjectMap[params]; ok {
 		for i, walkCh := range walkChs {
 			if !walkCh.timedOut {
 				newWalkChs := walkChs[i+1:]
 				if len(newWalkChs) > 0 {
-					listObjectMap[params] = newWalkChs
+					fs.listObjectMap[params] = newWalkChs
 				} else {
-					delete(listObjectMap, params)
+					delete(fs.listObjectMap, params)
 				}
 				return walkCh
 			}
 		}
 		// As all channels are timed out, delete the map entry
-		delete(listObjectMap, params)
+		delete(fs.listObjectMap, params)
 	}
 	return nil
 }

tree-walk-xl.go

@@ -0,0 +1,265 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"math/rand"
+	"path"
+	"sort"
+	"strings"
+	"time"
+)
+
+// listParams - list object params used for list object map
+type listParams struct {
+	bucket    string
+	recursive bool
+	marker    string
+	prefix    string
+}
+
+// Tree walk result carries results of tree walking.
+type treeWalkResult struct {
+	objInfo ObjectInfo
+	err     error
+	end     bool
+}
+
+// Tree walk notify carries a channel which notifies tree walk
+// results, additionally it also carries information if treeWalk
+// should be timedOut.
+type treeWalker struct {
+	ch       <-chan treeWalkResult
+	timedOut bool
+}
+
+// listDir - listDir.
+func (xl xlObjects) listDir(bucket, prefixDir string, filter func(entry string) bool) (entries []string, err error) {
+	// Count for list errors encountered.
+	var listErrCount = 0
+
+	// Loop through and return the first success entry based on the
+	// selected random disk.
+	for listErrCount < len(xl.storageDisks) {
+		// Choose a random disk on each attempt, do not hit the same disk all the time.
+		randIndex := rand.Intn(len(xl.storageDisks) - 1)
+		disk := xl.storageDisks[randIndex] // Pick a random disk.
+		if entries, err = disk.ListDir(bucket, prefixDir); err == nil {
+			// Skip the entries which do not match the filter.
+			for i, entry := range entries {
+				if filter(entry) {
+					entries[i] = ""
+					continue
+				}
+				if strings.HasSuffix(entry, slashSeparator) && xl.isObject(bucket, path.Join(prefixDir, entry)) {
+					entries[i] = strings.TrimSuffix(entry, slashSeparator)
+				}
+			}
+			sort.Strings(entries)
+			// Skip the empty strings
+			for len(entries) > 0 && entries[0] == "" {
+				entries = entries[1:]
+			}
+			return entries, nil
+		}
+		listErrCount++ // Update list error count.
+	}
+
+	// Return error at the end.
+	return nil, err
+}
+
+// getRandomDisk - gives a random disk at any point in time from the
+// available disk pool.
+func (xl xlObjects) getRandomDisk() (disk StorageAPI) {
+	randIndex := rand.Intn(len(xl.storageDisks) - 1)
+	disk = xl.storageDisks[randIndex] // Pick a random disk.
+	return disk
+}
+
+// treeWalkXL walks directory tree recursively pushing fileInfo into the channel as and when it encounters files.
+func (xl xlObjects) treeWalkXL(bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, send func(treeWalkResult) bool, count *int) bool {
+	// Example:
+	// if prefixDir="one/two/three/" and marker="four/five.txt" treeWalk is recursively
+	// called with prefixDir="one/two/three/four/" and marker="five.txt"
+
+	// Convert entry to FileInfo
+	entryToObjectInfo := func(entry string) (objInfo ObjectInfo, err error) {
+		if strings.HasSuffix(entry, slashSeparator) {
+			// Object name needs to be full path.
+			objInfo.Bucket = bucket
+			objInfo.Name = path.Join(prefixDir, entry)
+			objInfo.Name += slashSeparator
+			objInfo.IsDir = true
+			return objInfo, nil
+		}
+		// Set the Mode to a "regular" file.
+		return xl.getObjectInfo(bucket, path.Join(prefixDir, entry))
+	}
+
+	var markerBase, markerDir string
+	if marker != "" {
+		// Ex: if marker="four/five.txt", markerDir="four/" markerBase="five.txt"
+		markerSplit := strings.SplitN(marker, slashSeparator, 2)
+		markerDir = markerSplit[0]
+		if len(markerSplit) == 2 {
+			markerDir += slashSeparator
+			markerBase = markerSplit[1]
+		}
+	}
+	entries, err := xl.listDir(bucket, prefixDir, func(entry string) bool {
+		return !strings.HasPrefix(entry, entryPrefixMatch)
+	})
+	if err != nil {
+		send(treeWalkResult{err: err})
+		return false
+	}
+	if len(entries) == 0 {
+		return true
+	}
+
+	// example:
+	// If markerDir="four/" Search() returns the index of "four/" in the sorted
+	// entries list so we skip all the entries till "four/"
+	idx := sort.Search(len(entries), func(i int) bool {
+		return entries[i] >= markerDir
+	})
+	entries = entries[idx:]
+	*count += len(entries)
+	for i, entry := range entries {
+		if i == 0 && markerDir == entry {
+			if !recursive {
+				// Skip as the marker would already be listed in the previous listing.
+				*count--
+				continue
+			}
+			if recursive && !strings.HasSuffix(entry, slashSeparator) {
+				// We should not skip for recursive listing and if markerDir is a directory
+				// for ex. if marker is "four/five.txt" markerDir will be "four/" which
+				// should not be skipped, instead it will need to be treeWalkXL()'ed into.
+
+				// Skip if it is a file though as it would be listed in previous listing.
+				*count--
+				continue
+			}
+		}
+
+		if recursive && strings.HasSuffix(entry, slashSeparator) {
+			// If the entry is a directory, we will need recurse into it.
+			markerArg := ""
+			if entry == markerDir {
+				// We need to pass "five.txt" as marker only if we are
+				// recursing into "four/"
+				markerArg = markerBase
+			}
+			*count--
+			prefixMatch := "" // Valid only for first level treeWalk and empty for subdirectories.
+			if !xl.treeWalkXL(bucket, path.Join(prefixDir, entry), prefixMatch, markerArg, recursive, send, count) {
+				return false
+			}
+			continue
+		}
+		*count--
+		objInfo, err := entryToObjectInfo(entry)
+		if err != nil {
+			// The file got deleted in the interim between ListDir() and StatFile()
+			// Ignore error and continue.
+			continue
+		}
+		if !send(treeWalkResult{objInfo: objInfo}) {
+			return false
+		}
+	}
+	return true
+}
+
+// Initiate a new treeWalk in a goroutine.
+func (xl xlObjects) startTreeWalkXL(bucket, prefix, marker string, recursive bool) *treeWalker {
+	// Example 1
+	// If prefix is "one/two/three/" and marker is "one/two/three/four/five.txt"
+	// treeWalk is called with prefixDir="one/two/three/" and marker="four/five.txt"
+	// and entryPrefixMatch=""
+
+	// Example 2
+	// if prefix is "one/two/th" and marker is "one/two/three/four/five.txt"
+	// treeWalk is called with prefixDir="one/two/" and marker="three/four/five.txt"
+	// and entryPrefixMatch="th"
+
+	ch := make(chan treeWalkResult, maxObjectList)
+	walkNotify := treeWalker{ch: ch}
+	entryPrefixMatch := prefix
+	prefixDir := ""
+	lastIndex := strings.LastIndex(prefix, slashSeparator)
+	if lastIndex != -1 {
+		entryPrefixMatch = prefix[lastIndex+1:]
+		prefixDir = prefix[:lastIndex+1]
+	}
+	count := 0
+	marker = strings.TrimPrefix(marker, prefixDir)
+	go func() {
+		defer close(ch)
+		send := func(walkResult treeWalkResult) bool {
+			if count == 0 {
+				walkResult.end = true
+			}
+			timer := time.After(time.Second * 60)
+			select {
+			case ch <- walkResult:
+				return true
+			case <-timer:
+				walkNotify.timedOut = true
+				return false
+			}
+		}
+		xl.treeWalkXL(bucket, prefixDir, entryPrefixMatch, marker, recursive, send, &count)
+	}()
+	return &walkNotify
+}
+
+// Save the goroutine reference in the map
+func (xl xlObjects) saveTreeWalkXL(params listParams, walker *treeWalker) {
+	xl.listObjectMapMutex.Lock()
+	defer xl.listObjectMapMutex.Unlock()
+
+	walkers, _ := xl.listObjectMap[params]
+	walkers = append(walkers, walker)
+
+	xl.listObjectMap[params] = walkers
+}
+
+// Lookup the goroutine reference from map
+func (xl xlObjects) lookupTreeWalkXL(params listParams) *treeWalker {
+	xl.listObjectMapMutex.Lock()
+	defer xl.listObjectMapMutex.Unlock()
+
+	if walkChs, ok := xl.listObjectMap[params]; ok {
+		for i, walkCh := range walkChs {
+			if !walkCh.timedOut {
+				newWalkChs := walkChs[i+1:]
+				if len(newWalkChs) > 0 {
+					xl.listObjectMap[params] = newWalkChs
+				} else {
+					delete(xl.listObjectMap, params)
+				}
+				return walkCh
+			}
+		}
+		// As all channels are timed out, delete the map entry
+		delete(xl.listObjectMap, params)
+	}
+	return nil
+}

xl-erasure-v1-common.go

@@ -1,204 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"errors"
-	slashpath "path"
-	"sync"
-)
-
-// Get the highest integer from a given integer slice.
-func highestInt(intSlice []int64) (highestInteger int64) {
-	highestInteger = int64(0)
-	for _, integer := range intSlice {
-		if highestInteger < integer {
-			highestInteger = integer
-		}
-	}
-	return highestInteger
-}
-
-// Extracts file versions from partsMetadata slice and returns version slice.
-func listFileVersions(partsMetadata []xlMetaV1, errs []error) (versions []int64) {
-	versions = make([]int64, len(partsMetadata))
-	for index, metadata := range partsMetadata {
-		if errs[index] == nil {
-			versions[index] = metadata.Stat.Version
-		} else {
-			versions[index] = -1
-		}
-	}
-	return versions
-}
-
-// reduceError - convert collection of errors into a single
-// error based on total errors and read quorum.
-func (xl XL) reduceError(errs []error) error {
-	fileNotFoundCount := 0
-	diskNotFoundCount := 0
-	volumeNotFoundCount := 0
-	diskAccessDeniedCount := 0
-	for _, err := range errs {
-		if err == errFileNotFound {
-			fileNotFoundCount++
-		} else if err == errDiskNotFound {
-			diskNotFoundCount++
-		} else if err == errVolumeAccessDenied {
-			diskAccessDeniedCount++
-		} else if err == errVolumeNotFound {
-			volumeNotFoundCount++
-		}
-	}
-	// If we have errors with 'file not found' greater than
-	// readQuorum, return as errFileNotFound.
-	// else if we have errors with 'volume not found' greater than
-	// readQuorum, return as errVolumeNotFound.
-	if fileNotFoundCount > len(xl.storageDisks)-xl.readQuorum {
-		return errFileNotFound
-	} else if volumeNotFoundCount > len(xl.storageDisks)-xl.readQuorum {
-		return errVolumeNotFound
-	}
-	// If we have errors with disk not found equal to the
-	// number of disks, return as errDiskNotFound.
-	if diskNotFoundCount == len(xl.storageDisks) {
-		return errDiskNotFound
-	} else if diskNotFoundCount > len(xl.storageDisks)-xl.readQuorum {
-		// If we have errors with 'disk not found' greater than
-		// readQuorum, return as errFileNotFound.
-		return errFileNotFound
-	}
-	// If we have errors with disk not found equal to the
-	// number of disks, return as errDiskNotFound.
-	if diskAccessDeniedCount == len(xl.storageDisks) {
-		return errVolumeAccessDenied
-	}
-	return nil
-}
-
-// Returns slice of online disks needed.
-// - slice returing readable disks.
-// - xlMetaV1
-// - bool value indicating if healing is needed.
-// - error if any.
-func (xl XL) listOnlineDisks(volume, path string) (onlineDisks []StorageAPI, mdata xlMetaV1, heal bool, err error) {
-	partsMetadata, errs := xl.getPartsMetadata(volume, path)
-	if err = xl.reduceError(errs); err != nil {
-		return nil, xlMetaV1{}, false, err
-	}
-	highestVersion := int64(0)
-	onlineDisks = make([]StorageAPI, len(xl.storageDisks))
-	// List all the file versions from partsMetadata list.
-	versions := listFileVersions(partsMetadata, errs)
-
-	// Get highest file version.
-	highestVersion = highestInt(versions)
-
-	// Pick online disks with version set to highestVersion.
-	onlineDiskCount := 0
-	for index, version := range versions {
-		if version == highestVersion {
-			mdata = partsMetadata[index]
-			onlineDisks[index] = xl.storageDisks[index]
-			onlineDiskCount++
-		} else {
-			onlineDisks[index] = nil
-		}
-	}
-
-	// If online disks count is lesser than configured disks, most
-	// probably we need to heal the file, additionally verify if the
-	// count is lesser than readQuorum, if not we throw an error.
-	if onlineDiskCount < len(xl.storageDisks) {
-		// Online disks lesser than total storage disks, needs to be
-		// healed. unless we do not have readQuorum.
-		heal = true
-		// Verify if online disks count are lesser than readQuorum
-		// threshold, return an error if yes.
-		if onlineDiskCount < xl.readQuorum {
-			return nil, xlMetaV1{}, false, errReadQuorum
-		}
-	}
-	return onlineDisks, mdata, heal, nil
-}
-
-// Get file.json metadata as a map slice.
-// Returns error slice indicating the failed metadata reads.
-// Read lockNS() should be done by caller.
-func (xl XL) getPartsMetadata(volume, path string) ([]xlMetaV1, []error) {
-	errs := make([]error, len(xl.storageDisks))
-	metadataArray := make([]xlMetaV1, len(xl.storageDisks))
-	xlMetaV1FilePath := slashpath.Join(path, xlMetaV1File)
-	var wg = &sync.WaitGroup{}
-	for index, disk := range xl.storageDisks {
-		wg.Add(1)
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			offset := int64(0)
-			metadataReader, err := disk.ReadFile(volume, xlMetaV1FilePath, offset)
-			if err != nil {
-				errs[index] = err
-				return
-			}
-			defer metadataReader.Close()
-
-			metadata, err := xlMetaV1Decode(metadataReader)
-			if err != nil {
-				// Unable to parse file.json, set error.
-				errs[index] = err
-				return
-			}
-			metadataArray[index] = metadata
-		}(index, disk)
-	}
-	wg.Wait()
-	return metadataArray, errs
-}
-
-// Writes/Updates `file.json` for given file. updateParts carries
-// index of disks where `file.json` needs to be updated.
-//
-// Returns collection of errors, indexed in accordance with input
-// updateParts order.
-// Write lockNS() should be done by caller.
-func (xl XL) updatePartsMetadata(volume, path string, metadata xlMetaV1, updateParts []bool) []error {
-	xlMetaV1FilePath := pathJoin(path, xlMetaV1File)
-	errs := make([]error, len(xl.storageDisks))
-
-	for index := range updateParts {
-		errs[index] = errors.New("Metadata not updated")
-	}
-
-	for index, shouldUpdate := range updateParts {
-		if !shouldUpdate {
-			continue
-		}
-		writer, err := xl.storageDisks[index].CreateFile(volume, xlMetaV1FilePath)
-		errs[index] = err
-		if err != nil {
-			continue
-		}
-		err = metadata.Write(writer)
-		if err != nil {
-			errs[index] = err
-			safeCloseAndRemove(writer)
-			continue
-		}
-		writer.Close()
-	}
-	return errs
-}

xl-erasure-v1-createfile.go

@@ -1,287 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"fmt"
-	"io"
-	slashpath "path"
-	"sync"
-	"time"
-)
-
-// Erasure block size.
-const erasureBlockSize = 4 * 1024 * 1024 // 4MiB.
-
-// cleanupCreateFileOps - cleans up all the temporary files and other
-// temporary data upon any failure.
-func (xl XL) cleanupCreateFileOps(volume, path string, writers ...io.WriteCloser) {
-	closeAndRemoveWriters(writers...)
-	for _, disk := range xl.storageDisks {
-		if err := disk.DeleteFile(volume, path); err != nil {
-			errorIf(err, "Unable to delete file.")
-		}
-	}
-}
-
-// Close and remove writers if they are safeFile.
-func closeAndRemoveWriters(writers ...io.WriteCloser) {
-	for _, writer := range writers {
-		if err := safeCloseAndRemove(writer); err != nil {
-			errorIf(err, "Failed to close writer.")
-		}
-	}
-}
-
-// WriteErasure reads predefined blocks, encodes them and writes to
-// configured storage disks.
-func (xl XL) writeErasure(volume, path string, reader *io.PipeReader, wcloser *waitCloser) {
-	// Release the block writer upon function return.
-	defer wcloser.release()
-
-	partsMetadata, errs := xl.getPartsMetadata(volume, path)
-
-	// Convert errs into meaningful err to be sent upwards if possible
-	// based on total number of errors and read quorum.
-	err := xl.reduceError(errs)
-	if err != nil && err != errFileNotFound {
-		reader.CloseWithError(err)
-		return
-	}
-
-	// List all the file versions on existing files.
-	versions := listFileVersions(partsMetadata, errs)
-	// Get highest file version.
-	higherVersion := highestInt(versions)
-	// Increment to have next higher version.
-	higherVersion++
-
-	writers := make([]io.WriteCloser, len(xl.storageDisks))
-
-	xlMetaV1FilePath := slashpath.Join(path, xlMetaV1File)
-	metadataWriters := make([]io.WriteCloser, len(xl.storageDisks))
-
-	// Save additional erasureMetadata.
-	modTime := time.Now().UTC()
-
-	createFileError := 0
-	for index, disk := range xl.storageDisks {
-		erasurePart := slashpath.Join(path, fmt.Sprintf("file.%d", index))
-		var writer io.WriteCloser
-		writer, err = disk.CreateFile(volume, erasurePart)
-		if err != nil {
-			// Treat errFileNameTooLong specially
-			if err == errFileNameTooLong {
-				xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-				reader.CloseWithError(err)
-				return
-			}
-
-			createFileError++
-
-			// We can safely allow CreateFile errors up to len(xl.storageDisks) - xl.writeQuorum
-			// otherwise return failure.
-			if createFileError <= len(xl.storageDisks)-xl.writeQuorum {
-				continue
-			}
-
-			// Remove previous temp writers for any failure.
-			xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-			reader.CloseWithError(errWriteQuorum)
-			return
-		}
-
-		// Create meta data file.
-		var metadataWriter io.WriteCloser
-		metadataWriter, err = disk.CreateFile(volume, xlMetaV1FilePath)
-		if err != nil {
-			createFileError++
-
-			// We can safely allow CreateFile errors up to
-			// len(xl.storageDisks) - xl.writeQuorum otherwise return failure.
-			if createFileError <= len(xl.storageDisks)-xl.writeQuorum {
-				continue
-			}
-
-			// Remove previous temp writers for any failure.
-			xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-			reader.CloseWithError(errWriteQuorum)
-			return
-		}
-
-		writers[index] = writer
-		metadataWriters[index] = metadataWriter
-	}
-
-	// Allocate 4MiB block size buffer for reading.
-	dataBuffer := make([]byte, erasureBlockSize)
-	var totalSize int64 // Saves total incoming stream size.
-	for {
-		// Read up to allocated block size.
-		var n int
-		n, err = io.ReadFull(reader, dataBuffer)
-		if err != nil {
-			// Any unexpected errors, close the pipe reader with error.
-			if err != io.ErrUnexpectedEOF && err != io.EOF {
-				// Remove all temp writers.
-				xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-				reader.CloseWithError(err)
-				return
-			}
-		}
-		// At EOF break out.
-		if err == io.EOF {
-			break
-		}
-		if n > 0 {
-			// Split the input buffer into data and parity blocks.
-			var dataBlocks [][]byte
-			dataBlocks, err = xl.ReedSolomon.Split(dataBuffer[0:n])
-			if err != nil {
-				// Remove all temp writers.
-				xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-				reader.CloseWithError(err)
-				return
-			}
-
-			// Encode parity blocks using data blocks.
-			err = xl.ReedSolomon.Encode(dataBlocks)
-			if err != nil {
-				// Remove all temp writers upon error.
-				xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-				reader.CloseWithError(err)
-				return
-			}
-
-			var wg = &sync.WaitGroup{}
-			var wErrs = make([]error, len(writers))
-			// Loop through and write encoded data to quorum disks.
-			for index, writer := range writers {
-				if writer == nil {
-					continue
-				}
-				wg.Add(1)
-				go func(index int, writer io.Writer) {
-					defer wg.Done()
-					encodedData := dataBlocks[index]
-					_, wErr := writers[index].Write(encodedData)
-					wErrs[index] = wErr
-				}(index, writer)
-			}
-			wg.Wait()
-			for _, wErr := range wErrs {
-				if wErr == nil {
-					continue
-				}
-				// Remove all temp writers upon error.
-				xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-				reader.CloseWithError(wErr)
-				return
-			}
-
-			// Update total written.
-			totalSize += int64(n)
-		}
-	}
-
-	// Initialize metadata map, save all erasure related metadata.
-	metadata := xlMetaV1{}
-	metadata.Version = "1"
-	metadata.Stat.Size = totalSize
-	metadata.Stat.ModTime = modTime
-	metadata.Minio.Release = minioReleaseTag
-	if len(xl.storageDisks) > len(writers) {
-		// Save file.version only if we wrote to less disks than all
-		// storage disks.
-		metadata.Stat.Version = higherVersion
-	}
-	metadata.Erasure.DataBlocks = xl.DataBlocks
-	metadata.Erasure.ParityBlocks = xl.ParityBlocks
-	metadata.Erasure.BlockSize = erasureBlockSize
-
-	// Write all the metadata.
-	// below case is not handled here
-	// Case: when storageDisks is 16 and write quorumDisks is 13,
-	//       meta data write failure up to 2 can be considered.
-	//       currently we fail for any meta data writes
-	for _, metadataWriter := range metadataWriters {
-		if metadataWriter == nil {
-			continue
-		}
-
-		// Write metadata.
-		err = metadata.Write(metadataWriter)
-		if err != nil {
-			// Remove temporary files.
-			xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-			reader.CloseWithError(err)
-			return
-		}
-	}
-
-	// Close all writers and metadata writers in routines.
-	for index, writer := range writers {
-		if writer == nil {
-			continue
-		}
-		// Safely wrote, now rename to its actual location.
-		if err = writer.Close(); err != nil {
-			// Remove all temp writers upon error.
-			xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-			reader.CloseWithError(err)
-			return
-		}
-
-		if metadataWriters[index] == nil {
-			continue
-		}
-		// Safely wrote, now rename to its actual location.
-		if err = metadataWriters[index].Close(); err != nil {
-			// Remove all temp writers upon error.
-			xl.cleanupCreateFileOps(volume, path, append(writers, metadataWriters...)...)
-			reader.CloseWithError(err)
-			return
-		}
-
-	}
-
-	// Close the pipe reader and return.
-	reader.Close()
-	return
-}
-
-// CreateFile - create a file.
-func (xl XL) CreateFile(volume, path string) (writeCloser io.WriteCloser, err error) {
-	if !isValidVolname(volume) {
-		return nil, errInvalidArgument
-	}
-	if !isValidPath(path) {
-		return nil, errInvalidArgument
-	}
-
-	// Initialize pipe for data pipe line.
-	pipeReader, pipeWriter := io.Pipe()
-
-	// Initialize a new wait closer, implements both Write and Close.
-	wcloser := newWaitCloser(pipeWriter)
-
-	// Start erasure encoding in routine, reading data block by block from pipeReader.
-	go xl.writeErasure(volume, path, pipeReader, wcloser)
-
-	// Return the writer, caller should start writing to this.
-	return wcloser, nil
-}

xl-erasure-v1-healfile.go

@@ -1,185 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	slashpath "path"
-)
-
-// healHeal - heals the file at path.
-func (xl XL) healFile(volume string, path string) error {
-	totalBlocks := xl.DataBlocks + xl.ParityBlocks
-	needsHeal := make([]bool, totalBlocks)
-	var readers = make([]io.Reader, totalBlocks)
-	var writers = make([]io.WriteCloser, totalBlocks)
-
-	// List all online disks to verify if we need to heal.
-	onlineDisks, metadata, heal, err := xl.listOnlineDisks(volume, path)
-	if err != nil {
-		return err
-	}
-	if !heal {
-		return nil
-	}
-
-	for index, disk := range onlineDisks {
-		if disk == nil {
-			needsHeal[index] = true
-			continue
-		}
-		erasurePart := slashpath.Join(path, fmt.Sprintf("file.%d", index))
-		// If disk.ReadFile returns error and we don't have read quorum it will be taken care as
-		// ReedSolomon.Reconstruct() will fail later.
-		var reader io.ReadCloser
-		offset := int64(0)
-		if reader, err = xl.storageDisks[index].ReadFile(volume, erasurePart, offset); err == nil {
-			readers[index] = reader
-			defer reader.Close()
-		}
-	}
-
-	// create writers for parts where healing is needed.
-	for index, healNeeded := range needsHeal {
-		if !healNeeded {
-			continue
-		}
-		erasurePart := slashpath.Join(path, fmt.Sprintf("file.%d", index))
-		writers[index], err = xl.storageDisks[index].CreateFile(volume, erasurePart)
-		if err != nil {
-			needsHeal[index] = false
-			safeCloseAndRemove(writers[index])
-			continue
-		}
-	}
-
-	// Check if there is atleast one part that needs to be healed.
-	atleastOneHeal := false
-	for _, healNeeded := range needsHeal {
-		if healNeeded {
-			atleastOneHeal = true
-			break
-		}
-	}
-	if !atleastOneHeal {
-		// Return if healing not needed anywhere.
-		return nil
-	}
-
-	var totalLeft = metadata.Stat.Size
-	for totalLeft > 0 {
-		// Figure out the right blockSize.
-		var curBlockSize int64
-		if metadata.Erasure.BlockSize < totalLeft {
-			curBlockSize = metadata.Erasure.BlockSize
-		} else {
-			curBlockSize = totalLeft
-		}
-		// Calculate the current block size.
-		curBlockSize = getEncodedBlockLen(curBlockSize, metadata.Erasure.DataBlocks)
-		enBlocks := make([][]byte, totalBlocks)
-		// Loop through all readers and read.
-		for index, reader := range readers {
-			// Initialize block slice and fill the data from each parts.
-			// ReedSolomon.Verify() expects that slice is not nil even if the particular
-			// part needs healing.
-			enBlocks[index] = make([]byte, curBlockSize)
-			if needsHeal[index] {
-				// Skip reading if the part needs healing.
-				continue
-			}
-			if reader == nil {
-				// If ReadFile() had returned error, do not read from this disk.
-				continue
-			}
-			_, err = io.ReadFull(reader, enBlocks[index])
-			if err != nil && err != io.ErrUnexpectedEOF {
-				enBlocks[index] = nil
-			}
-		}
-
-		// Check blocks if they are all zero in length.
-		if checkBlockSize(enBlocks) == 0 {
-			return errDataCorrupt
-		}
-
-		// Verify the blocks.
-		ok, err := xl.ReedSolomon.Verify(enBlocks)
-		if err != nil {
-			closeAndRemoveWriters(writers...)
-			return err
-		}
-
-		// Verification failed, blocks require reconstruction.
-		if !ok {
-			for index, healNeeded := range needsHeal {
-				if healNeeded {
-					// Reconstructs() reconstructs the parts if the array is nil.
-					enBlocks[index] = nil
-				}
-			}
-			err = xl.ReedSolomon.Reconstruct(enBlocks)
-			if err != nil {
-				closeAndRemoveWriters(writers...)
-				return err
-			}
-			// Verify reconstructed blocks again.
-			ok, err = xl.ReedSolomon.Verify(enBlocks)
-			if err != nil {
-				closeAndRemoveWriters(writers...)
-				return err
-			}
-			if !ok {
-				// Blocks cannot be reconstructed, corrupted data.
-				err = errors.New("Verification failed after reconstruction, data likely corrupted.")
-				closeAndRemoveWriters(writers...)
-				return err
-			}
-		}
-		for index, healNeeded := range needsHeal {
-			if !healNeeded {
-				continue
-			}
-			_, err := writers[index].Write(enBlocks[index])
-			if err != nil {
-				safeCloseAndRemove(writers[index])
-				continue
-			}
-		}
-		totalLeft = totalLeft - metadata.Erasure.BlockSize
-	}
-
-	// After successful healing Close() the writer so that the temp
-	// files are committed to their location.
-	for _, writer := range writers {
-		if writer == nil {
-			continue
-		}
-		writer.Close()
-	}
-
-	// Update the quorum metadata after heal.
-	errs := xl.updatePartsMetadata(volume, path, metadata, needsHeal)
-	for index, healNeeded := range needsHeal {
-		if healNeeded && errs[index] != nil {
-			return errs[index]
-		}
-	}
-	return nil
-}

xl-erasure-v1-metadata.go

@@ -1,61 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"encoding/json"
-	"io"
-	"time"
-)
-
-// A xlMetaV1 represents a metadata header mapping keys to sets of values.
-type xlMetaV1 struct {
-	Version string `json:"version"`
-	Stat    struct {
-		Size    int64     `json:"size"`
-		ModTime time.Time `json:"modTime"`
-		Version int64     `json:"version"`
-	} `json:"stat"`
-	Erasure struct {
-		DataBlocks   int   `json:"data"`
-		ParityBlocks int   `json:"parity"`
-		BlockSize    int64 `json:"blockSize"`
-	} `json:"erasure"`
-	Minio struct {
-		Release string `json:"release"`
-	} `json:"minio"`
-}
-
-// Write writes a metadata in wire format.
-func (m xlMetaV1) Write(writer io.Writer) error {
-	metadataBytes, err := json.Marshal(m)
-	if err != nil {
-		return err
-	}
-	_, err = writer.Write(metadataBytes)
-	return err
-}
-
-// xlMetaV1Decode - file metadata decode.
-func xlMetaV1Decode(reader io.Reader) (metadata xlMetaV1, err error) {
-	decoder := json.NewDecoder(reader)
-	// Unmarshalling failed, file possibly corrupted.
-	if err = decoder.Decode(&metadata); err != nil {
-		return xlMetaV1{}, err
-	}
-	return metadata, nil
-}

xl-erasure-v1.go

@@ -1,546 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"errors"
-	"fmt"
-	"math/rand"
-	"os"
-	slashpath "path"
-	"strings"
-
-	"path"
-	"sync"
-
-	"github.com/klauspost/reedsolomon"
-)
-
-const (
-	// XL erasure metadata file.
-	xlMetaV1File = "file.json"
-)
-
-// XL layer structure.
-type XL struct {
-	ReedSolomon  reedsolomon.Encoder // Erasure encoder/decoder.
-	DataBlocks   int
-	ParityBlocks int
-	storageDisks []StorageAPI
-	readQuorum   int
-	writeQuorum  int
-}
-
-// errUnexpected - returned for any unexpected error.
-var errUnexpected = errors.New("Unexpected error - please report at https://github.com/minio/minio/issues")
-
-// newXL instantiate a new XL.
-func newXL(disks []StorageAPI) (StorageAPI, error) {
-	// Initialize XL.
-	xl := &XL{}
-
-	// Calculate data and parity blocks.
-	dataBlocks, parityBlocks := len(disks)/2, len(disks)/2
-
-	// Initialize reed solomon encoding.
-	rs, err := reedsolomon.New(dataBlocks, parityBlocks)
-	if err != nil {
-		return nil, err
-	}
-
-	// Save the reedsolomon.
-	xl.DataBlocks = dataBlocks
-	xl.ParityBlocks = parityBlocks
-	xl.ReedSolomon = rs
-
-	// Save all the initialized storage disks.
-	xl.storageDisks = disks
-
-	// Figure out read and write quorum based on number of storage disks.
-	// Read quorum should be always N/2 + 1 (due to Vandermonde matrix
-	// erasure requirements)
-	xl.readQuorum = len(xl.storageDisks)/2 + 1
-
-	// Write quorum is assumed if we have total disks + 3
-	// parity. (Need to discuss this again)
-	xl.writeQuorum = len(xl.storageDisks)/2 + 3
-	if xl.writeQuorum > len(xl.storageDisks) {
-		xl.writeQuorum = len(xl.storageDisks)
-	}
-
-	// Return successfully initialized.
-	return xl, nil
-}
-
-// MakeVol - make a volume.
-func (xl XL) MakeVol(volume string) error {
-	if !isValidVolname(volume) {
-		return errInvalidArgument
-	}
-
-	// Err counters.
-	createVolErr := 0       // Count generic create vol errs.
-	volumeExistsErrCnt := 0 // Count all errVolumeExists errs.
-
-	// Initialize sync waitgroup.
-	var wg = &sync.WaitGroup{}
-
-	// Initialize list of errors.
-	var dErrs = make([]error, len(xl.storageDisks))
-
-	// Make a volume entry on all underlying storage disks.
-	for index, disk := range xl.storageDisks {
-		wg.Add(1)
-		// Make a volume inside a go-routine.
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			if disk == nil {
-				return
-			}
-			dErrs[index] = disk.MakeVol(volume)
-		}(index, disk)
-	}
-
-	// Wait for all make vol to finish.
-	wg.Wait()
-
-	// Loop through all the concocted errors.
-	for _, err := range dErrs {
-		if err == nil {
-			continue
-		}
-		// if volume already exists, count them.
-		if err == errVolumeExists {
-			volumeExistsErrCnt++
-			continue
-		}
-
-		// Update error counter separately.
-		createVolErr++
-	}
-	// Return err if all disks report volume exists.
-	if volumeExistsErrCnt == len(xl.storageDisks) {
-		return errVolumeExists
-	} else if createVolErr > len(xl.storageDisks)-xl.writeQuorum {
-		// Return errWriteQuorum if errors were more than
-		// allowed write quorum.
-		return errWriteQuorum
-	}
-	return nil
-}
-
-// DeleteVol - delete a volume.
-func (xl XL) DeleteVol(volume string) error {
-	if !isValidVolname(volume) {
-		return errInvalidArgument
-	}
-
-	// Collect if all disks report volume not found.
-	var volumeNotFoundErrCnt int
-
-	var wg = &sync.WaitGroup{}
-	var dErrs = make([]error, len(xl.storageDisks))
-
-	// Remove a volume entry on all underlying storage disks.
-	for index, disk := range xl.storageDisks {
-		wg.Add(1)
-		// Delete volume inside a go-routine.
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			dErrs[index] = disk.DeleteVol(volume)
-		}(index, disk)
-	}
-
-	// Wait for all the delete vols to finish.
-	wg.Wait()
-
-	// Loop through concocted errors and return anything unusual.
-	for _, err := range dErrs {
-		if err != nil {
-			// We ignore error if errVolumeNotFound or errDiskNotFound
-			if err == errVolumeNotFound || err == errDiskNotFound {
-				volumeNotFoundErrCnt++
-				continue
-			}
-			return err
-		}
-	}
-	// Return err if all disks report volume not found.
-	if volumeNotFoundErrCnt == len(xl.storageDisks) {
-		return errVolumeNotFound
-	}
-	return nil
-}
-
-// ListVols - list volumes.
-func (xl XL) ListVols() (volsInfo []VolInfo, err error) {
-	// Initialize sync waitgroup.
-	var wg = &sync.WaitGroup{}
-
-	// Success vols map carries successful results of ListVols from each disks.
-	var successVols = make([][]VolInfo, len(xl.storageDisks))
-	for index, disk := range xl.storageDisks {
-		wg.Add(1) // Add each go-routine to wait for.
-		go func(index int, disk StorageAPI) {
-			// Indicate wait group as finished.
-			defer wg.Done()
-
-			// Initiate listing.
-			vlsInfo, _ := disk.ListVols()
-			successVols[index] = vlsInfo
-		}(index, disk)
-	}
-
-	// For all the list volumes running in parallel to finish.
-	wg.Wait()
-
-	// Loop through success vols and get aggregated usage values.
-	var vlsInfo []VolInfo
-	var total, free int64
-	for _, vlsInfo = range successVols {
-		if len(vlsInfo) <= 1 {
-			continue
-		}
-		var vlInfo VolInfo
-		for _, vlInfo = range vlsInfo {
-			if vlInfo.Name == "" {
-				continue
-			}
-			break
-		}
-		free += vlInfo.Free
-		total += vlInfo.Total
-	}
-
-	// Save the updated usage values back into the vols.
-	for _, vlInfo := range vlsInfo {
-		vlInfo.Free = free
-		vlInfo.Total = total
-		volsInfo = append(volsInfo, vlInfo)
-	}
-
-	// NOTE: The assumption here is that volumes across all disks in
-	// readQuorum have consistent view i.e they all have same number
-	// of buckets. This is essentially not verified since healing
-	// should take care of this.
-	return volsInfo, nil
-}
-
-// getAllVolInfo - list bucket volume info from all disks.
-// Returns error slice indicating the failed volume stat operations.
-func (xl XL) getAllVolInfo(volume string) ([]VolInfo, []error) {
-	// Create errs and volInfo slices of storageDisks size.
-	var errs = make([]error, len(xl.storageDisks))
-	var volsInfo = make([]VolInfo, len(xl.storageDisks))
-
-	// Allocate a new waitgroup.
-	var wg = &sync.WaitGroup{}
-	for index, disk := range xl.storageDisks {
-		wg.Add(1)
-		// Stat volume on all the disks in a routine.
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			volInfo, err := disk.StatVol(volume)
-			if err != nil {
-				errs[index] = err
-				return
-			}
-			volsInfo[index] = volInfo
-		}(index, disk)
-	}
-
-	// Wait for all the Stat operations to finish.
-	wg.Wait()
-
-	// Return the concocted values.
-	return volsInfo, errs
-}
-
-// listAllVolInfo - list all stat volume info from all disks.
-// Returns
-// - stat volume info for all online disks.
-// - boolean to indicate if healing is necessary.
-// - error if any.
-func (xl XL) listAllVolInfo(volume string) ([]VolInfo, bool, error) {
-	volsInfo, errs := xl.getAllVolInfo(volume)
-	notFoundCount := 0
-	for _, err := range errs {
-		if err == errVolumeNotFound {
-			notFoundCount++
-			// If we have errors with file not found greater than allowed read
-			// quorum we return err as errFileNotFound.
-			if notFoundCount > len(xl.storageDisks)-xl.readQuorum {
-				return nil, false, errVolumeNotFound
-			}
-		}
-	}
-
-	// Calculate online disk count.
-	onlineDiskCount := 0
-	for index := range errs {
-		if errs[index] == nil {
-			onlineDiskCount++
-		}
-	}
-
-	var heal bool
-	// If online disks count is lesser than configured disks, most
-	// probably we need to heal the file, additionally verify if the
-	// count is lesser than readQuorum, if not we throw an error.
-	if onlineDiskCount < len(xl.storageDisks) {
-		// Online disks lesser than total storage disks, needs to be
-		// healed. unless we do not have readQuorum.
-		heal = true
-		// Verify if online disks count are lesser than readQuorum
-		// threshold, return an error if yes.
-		if onlineDiskCount < xl.readQuorum {
-			return nil, false, errReadQuorum
-		}
-	}
-
-	// Return success.
-	return volsInfo, heal, nil
-}
-
-// StatVol - get volume stat info.
-func (xl XL) StatVol(volume string) (volInfo VolInfo, err error) {
-	if !isValidVolname(volume) {
-		return VolInfo{}, errInvalidArgument
-	}
-
-	// List and figured out if we need healing.
-	volsInfo, heal, err := xl.listAllVolInfo(volume)
-	if err != nil {
-		return VolInfo{}, err
-	}
-
-	// Heal for missing entries.
-	if heal {
-		go func() {
-			// Create volume if missing on disks.
-			for index, volInfo := range volsInfo {
-				if volInfo.Name != "" {
-					continue
-				}
-				// Volinfo name would be an empty string, create it.
-				xl.storageDisks[index].MakeVol(volume)
-			}
-		}()
-	}
-
-	// Loop through all statVols, calculate the actual usage values.
-	var total, free int64
-	for _, volInfo = range volsInfo {
-		if volInfo.Name == "" {
-			continue
-		}
-		free += volInfo.Free
-		total += volInfo.Total
-	}
-	// Update the aggregated values.
-	volInfo.Free = free
-	volInfo.Total = total
-	return volInfo, nil
-}
-
-// isLeafDirectoryXL - check if a given path is leaf directory. i.e
-// if it contains file xlMetaV1File
-func isLeafDirectoryXL(disk StorageAPI, volume, leafPath string) (isLeaf bool) {
-	_, err := disk.StatFile(volume, path.Join(leafPath, xlMetaV1File))
-	return err == nil
-}
-
-// ListDir - return all the entries at the given directory path.
-// If an entry is a directory it will be returned with a trailing "/".
-func (xl XL) ListDir(volume, dirPath string) (entries []string, err error) {
-	if !isValidVolname(volume) {
-		return nil, errInvalidArgument
-	}
-
-	// Count for list errors encountered.
-	var listErrCount = 0
-
-	// Loop through and return the first success entry based on the
-	// selected random disk.
-	for listErrCount < len(xl.storageDisks) {
-		// Choose a random disk on each attempt, do not hit the same disk all the time.
-		randIndex := rand.Intn(len(xl.storageDisks) - 1)
-		disk := xl.storageDisks[randIndex] // Pick a random disk.
-		// Initiate a list operation, if successful filter and return quickly.
-		if entries, err = disk.ListDir(volume, dirPath); err == nil {
-			for i, entry := range entries {
-				isLeaf := isLeafDirectoryXL(disk, volume, path.Join(dirPath, entry))
-				isDir := strings.HasSuffix(entry, slashSeparator)
-				if isDir && isLeaf {
-					entries[i] = strings.TrimSuffix(entry, slashSeparator)
-				}
-			}
-			// We got the entries successfully return.
-			return entries, nil
-		}
-		listErrCount++ // Update list error count.
-	}
-	// Return error at the end.
-	return nil, err
-}
-
-// Object API.
-
-// StatFile - stat a file
-func (xl XL) StatFile(volume, path string) (FileInfo, error) {
-	if !isValidVolname(volume) {
-		return FileInfo{}, errInvalidArgument
-	}
-	if !isValidPath(path) {
-		return FileInfo{}, errInvalidArgument
-	}
-
-	_, metadata, heal, err := xl.listOnlineDisks(volume, path)
-	if err != nil {
-		return FileInfo{}, err
-	}
-
-	if heal {
-		// Heal in background safely, since we already have read quorum disks.
-		go func() {
-			hErr := xl.healFile(volume, path)
-			errorIf(hErr, "Unable to heal file "+volume+"/"+path+".")
-		}()
-	}
-
-	// Return file info.
-	return FileInfo{
-		Volume:  volume,
-		Name:    path,
-		Size:    metadata.Stat.Size,
-		ModTime: metadata.Stat.ModTime,
-		Mode:    os.FileMode(0644),
-	}, nil
-}
-
-// deleteXLFiles - delete all XL backend files.
-func (xl XL) deleteXLFiles(volume, path string) error {
-	errCount := 0
-	// Update meta data file and remove part file
-	for index, disk := range xl.storageDisks {
-		erasureFilePart := slashpath.Join(path, fmt.Sprintf("file.%d", index))
-		err := disk.DeleteFile(volume, erasureFilePart)
-		if err != nil {
-			errCount++
-
-			// We can safely allow DeleteFile errors up to len(xl.storageDisks) - xl.writeQuorum
-			// otherwise return failure.
-			if errCount <= len(xl.storageDisks)-xl.writeQuorum {
-				continue
-			}
-
-			return err
-		}
-
-		xlMetaV1FilePath := slashpath.Join(path, "file.json")
-		err = disk.DeleteFile(volume, xlMetaV1FilePath)
-		if err != nil {
-			errCount++
-
-			// We can safely allow DeleteFile errors up to len(xl.storageDisks) - xl.writeQuorum
-			// otherwise return failure.
-			if errCount <= len(xl.storageDisks)-xl.writeQuorum {
-				continue
-			}
-
-			return err
-		}
-	}
-	// Return success.
-	return nil
-}
-
-// DeleteFile - delete a file
-func (xl XL) DeleteFile(volume, path string) error {
-	if !isValidVolname(volume) {
-		return errInvalidArgument
-	}
-	if !isValidPath(path) {
-		return errInvalidArgument
-	}
-
-	// Delete all XL files.
-	return xl.deleteXLFiles(volume, path)
-}
-
-// RenameFile - rename file.
-func (xl XL) RenameFile(srcVolume, srcPath, dstVolume, dstPath string) error {
-	// Validate inputs.
-	if !isValidVolname(srcVolume) {
-		return errInvalidArgument
-	}
-	if !isValidPath(srcPath) {
-		return errInvalidArgument
-	}
-	if !isValidVolname(dstVolume) {
-		return errInvalidArgument
-	}
-	if !isValidPath(dstPath) {
-		return errInvalidArgument
-	}
-
-	// Initialize sync waitgroup.
-	var wg = &sync.WaitGroup{}
-
-	// Initialize list of errors.
-	var errs = make([]error, len(xl.storageDisks))
-
-	// Rename file on all underlying storage disks.
-	for index, disk := range xl.storageDisks {
-		// Append "/" as srcPath and dstPath are either leaf-dirs or non-leaf-dris.
-		// If srcPath is an object instead of prefix we just rename the leaf-dir and
-		// not rename the part and metadata files separately.
-		wg.Add(1)
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			err := disk.RenameFile(srcVolume, retainSlash(srcPath), dstVolume, retainSlash(dstPath))
-			if err != nil {
-				errs[index] = err
-			}
-			errs[index] = nil
-		}(index, disk)
-	}
-
-	// Wait for all RenameFile to finish.
-	wg.Wait()
-
-	// Gather err count.
-	var errCount = 0
-	for _, err := range errs {
-		if err == nil {
-			continue
-		}
-		errCount++
-	}
-	// We can safely allow RenameFile errors up to len(xl.storageDisks) - xl.writeQuorum
-	// otherwise return failure. Cleanup successful renames.
-	if errCount > len(xl.storageDisks)-xl.writeQuorum {
-		// Special condition if readQuorum exists, then return success.
-		if errCount <= len(xl.storageDisks)-xl.readQuorum {
-			return nil
-		}
-		// Ignore errors here, delete all successfully written files.
-		xl.deleteXLFiles(dstVolume, dstPath)
-		return errWriteQuorum
-	}
-	return nil
-}

xl-objects-multipart.go

@@ -1,336 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"encoding/json"
-	"fmt"
-	"io"
-	"path"
-	"strings"
-	"sync"
-	"time"
-)
-
-// MultipartPartInfo Info of each part kept in the multipart metadata file after
-// CompleteMultipartUpload() is called.
-type MultipartPartInfo struct {
-	PartNumber int
-	ETag       string
-	Size       int64
-}
-
-// MultipartObjectInfo - contents of the multipart metadata file after
-// CompleteMultipartUpload() is called.
-type MultipartObjectInfo struct {
-	Parts           []MultipartPartInfo
-	ModTime         time.Time
-	Size            int64
-	MD5Sum          string
-	ContentType     string
-	ContentEncoding string
-	// Add more fields here.
-}
-
-type byMultipartFiles []string
-
-func (files byMultipartFiles) Len() int { return len(files) }
-func (files byMultipartFiles) Less(i, j int) bool {
-	first := strings.TrimSuffix(files[i], multipartSuffix)
-	second := strings.TrimSuffix(files[j], multipartSuffix)
-	return first < second
-}
-func (files byMultipartFiles) Swap(i, j int) { files[i], files[j] = files[j], files[i] }
-
-// GetPartNumberOffset - given an offset for the whole object, return the part and offset in that part.
-func (m MultipartObjectInfo) GetPartNumberOffset(offset int64) (partIndex int, partOffset int64, err error) {
-	partOffset = offset
-	for i, part := range m.Parts {
-		partIndex = i
-		if partOffset < part.Size {
-			return
-		}
-		partOffset -= part.Size
-	}
-	// Offset beyond the size of the object
-	err = errUnexpected
-	return
-}
-
-// getMultipartObjectMeta - incomplete meta file and extract meta information if any.
-func getMultipartObjectMeta(storage StorageAPI, metaFile string) (meta map[string]string, err error) {
-	meta = make(map[string]string)
-	offset := int64(0)
-	objMetaReader, err := storage.ReadFile(minioMetaBucket, metaFile, offset)
-	if err != nil {
-		return nil, err
-	}
-	// Close the metadata reader.
-	defer objMetaReader.Close()
-
-	decoder := json.NewDecoder(objMetaReader)
-	err = decoder.Decode(&meta)
-	if err != nil {
-		return nil, err
-	}
-	return meta, nil
-}
-
-func partNumToPartFileName(partNum int) string {
-	return fmt.Sprintf("%.5d%s", partNum, multipartSuffix)
-}
-
-// ListMultipartUploads - list multipart uploads.
-func (xl xlObjects) ListMultipartUploads(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
-	return listMultipartUploadsCommon(xl, bucket, prefix, keyMarker, uploadIDMarker, delimiter, maxUploads)
-}
-
-// NewMultipartUpload - initialize a new multipart upload, returns a unique id.
-func (xl xlObjects) NewMultipartUpload(bucket, object string, meta map[string]string) (string, error) {
-	return newMultipartUploadCommon(xl.storage, bucket, object, meta)
-}
-
-// PutObjectPart - writes the multipart upload chunks.
-func (xl xlObjects) PutObjectPart(bucket, object, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
-	return putObjectPartCommon(xl.storage, bucket, object, uploadID, partID, size, data, md5Hex)
-}
-
-// ListObjectParts - list object parts.
-func (xl xlObjects) ListObjectParts(bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
-	return listObjectPartsCommon(xl.storage, bucket, object, uploadID, partNumberMarker, maxParts)
-}
-
-// This function does the following check, suppose
-// object is "a/b/c/d", stat makes sure that objects ""a/b/c""
-// "a/b" and "a" do not exist.
-func (xl xlObjects) parentDirIsObject(bucket, parent string) error {
-	var stat func(string) error
-	stat = func(p string) error {
-		if p == "." {
-			return nil
-		}
-		_, err := xl.getObjectInfo(bucket, p)
-		if err == nil {
-			// If there is already a file at prefix "p" return error.
-			return errFileAccessDenied
-		}
-		if err == errFileNotFound {
-			// Check if there is a file as one of the parent paths.
-			return stat(path.Dir(p))
-		}
-		return err
-	}
-	return stat(parent)
-}
-
-func (xl xlObjects) CompleteMultipartUpload(bucket string, object string, uploadID string, parts []completePart) (string, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return "", BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify whether the bucket exists.
-	if !isBucketExist(xl.storage, bucket) {
-		return "", BucketNotFound{Bucket: bucket}
-	}
-	if !IsValidObjectName(object) {
-		return "", ObjectNameInvalid{
-			Bucket: bucket,
-			Object: object,
-		}
-	}
-	if !isUploadIDExists(xl.storage, bucket, object, uploadID) {
-		return "", InvalidUploadID{UploadID: uploadID}
-	}
-	// Hold lock so that
-	// 1) no one aborts this multipart upload
-	// 2) no one does a parallel complete-multipart-upload on this multipart upload
-	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
-	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
-
-	// Calculate s3 compatible md5sum for complete multipart.
-	s3MD5, err := completeMultipartMD5(parts...)
-	if err != nil {
-		return "", err
-	}
-
-	var metadata = MultipartObjectInfo{}
-	var errs = make([]error, len(parts))
-
-	uploadIDIncompletePath := path.Join(mpartMetaPrefix, bucket, object, uploadID, incompleteFile)
-	objMeta, err := getMultipartObjectMeta(xl.storage, uploadIDIncompletePath)
-	if err != nil {
-		return "", toObjectErr(err, minioMetaBucket, uploadIDIncompletePath)
-	}
-
-	// Waitgroup to wait for go-routines.
-	var wg = &sync.WaitGroup{}
-
-	// Loop through all parts, validate them and then commit to disk.
-	for i, part := range parts {
-		// Construct part suffix.
-		partSuffix := fmt.Sprintf("%.5d.%s", part.PartNumber, part.ETag)
-		multipartPartFile := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffix)
-		var fi FileInfo
-		fi, err = xl.storage.StatFile(minioMetaBucket, multipartPartFile)
-		if err != nil {
-			if err == errFileNotFound {
-				return "", InvalidPart{}
-			}
-			return "", err
-		}
-		// All parts except the last part has to be atleast 5MB.
-		if (i < len(parts)-1) && !isMinAllowedPartSize(fi.Size) {
-			return "", PartTooSmall{}
-		}
-		// Update metadata parts.
-		metadata.Parts = append(metadata.Parts, MultipartPartInfo{
-			PartNumber: part.PartNumber,
-			ETag:       part.ETag,
-			Size:       fi.Size,
-		})
-		metadata.Size += fi.Size
-	}
-
-	// check if an object is present as one of the parent dir.
-	if err = xl.parentDirIsObject(bucket, path.Dir(object)); err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Save successfully calculated md5sum.
-	metadata.MD5Sum = s3MD5
-	metadata.ContentType = objMeta["content-type"]
-	metadata.ContentEncoding = objMeta["content-encoding"]
-
-	// Save modTime as well as the current time.
-	metadata.ModTime = time.Now().UTC()
-
-	// Create temporary multipart meta file to write and then rename.
-	multipartMetaSuffix := fmt.Sprintf("%s.%s", uploadID, multipartMetaFile)
-	tempMultipartMetaFile := path.Join(tmpMetaPrefix, bucket, object, multipartMetaSuffix)
-	w, err := xl.storage.CreateFile(minioMetaBucket, tempMultipartMetaFile)
-	if err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-	encoder := json.NewEncoder(w)
-	err = encoder.Encode(&metadata)
-	if err != nil {
-		if err = safeCloseAndRemove(w); err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-	// Close the writer.
-	if err = w.Close(); err != nil {
-		if err = safeCloseAndRemove(w); err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Attempt a Rename of multipart meta file to final namespace.
-	multipartObjFile := path.Join(mpartMetaPrefix, bucket, object, uploadID, multipartMetaFile)
-	err = xl.storage.RenameFile(minioMetaBucket, tempMultipartMetaFile, minioMetaBucket, multipartObjFile)
-	if err != nil {
-		if derr := xl.storage.DeleteFile(minioMetaBucket, tempMultipartMetaFile); derr != nil {
-			return "", toObjectErr(err, minioMetaBucket, tempMultipartMetaFile)
-		}
-		return "", toObjectErr(err, bucket, multipartObjFile)
-	}
-
-	// Loop through and atomically rename the parts to their actual location.
-	for index, part := range parts {
-		wg.Add(1)
-		go func(index int, part completePart) {
-			defer wg.Done()
-			partSuffix := fmt.Sprintf("%.5d.%s", part.PartNumber, part.ETag)
-			src := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffix)
-			dst := path.Join(mpartMetaPrefix, bucket, object, uploadID, partNumToPartFileName(part.PartNumber))
-			errs[index] = xl.storage.RenameFile(minioMetaBucket, src, minioMetaBucket, dst)
-			errorIf(errs[index], "Unable to rename file %s to %s.", src, dst)
-		}(index, part)
-	}
-
-	// Wait for all the renames to finish.
-	wg.Wait()
-
-	// Loop through errs list and return first error.
-	for _, err := range errs {
-		if err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-	}
-
-	// Delete the incomplete file place holder.
-	err = xl.storage.DeleteFile(minioMetaBucket, uploadIDIncompletePath)
-	if err != nil {
-		return "", toObjectErr(err, minioMetaBucket, uploadIDIncompletePath)
-	}
-
-	// Hold write lock on the destination before rename
-	nsMutex.Lock(bucket, object)
-	defer nsMutex.Unlock(bucket, object)
-
-	// Delete if an object already exists.
-	// FIXME: rename it to tmp file and delete only after
-	// the newly uploaded file is renamed from tmp location to
-	// the original location.
-	// Verify if the object is a multipart object.
-	if isMultipartObject(xl.storage, bucket, object) {
-		err = xl.deleteMultipartObject(bucket, object)
-		if err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-		return s3MD5, nil
-	}
-	err = xl.deleteObject(bucket, object)
-	if err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
-	if err = xl.storage.RenameFile(minioMetaBucket, uploadIDPath, bucket, object); err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Hold the lock so that two parallel complete-multipart-uploads do no
-	// leave a stale uploads.json behind.
-	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
-	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
-
-	// Validate if there are other incomplete upload-id's present for
-	// the object, if yes do not attempt to delete 'uploads.json'.
-	var entries []string
-	if entries, err = xl.storage.ListDir(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object)); err == nil {
-		if len(entries) > 1 {
-			return s3MD5, nil
-		}
-	}
-
-	uploadsJSONPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
-	err = xl.storage.DeleteFile(minioMetaBucket, uploadsJSONPath)
-	if err != nil {
-		return "", toObjectErr(err, minioMetaBucket, uploadsJSONPath)
-	}
-
-	// Return md5sum.
-	return s3MD5, nil
-}
-
-// AbortMultipartUpload - aborts a multipart upload.
-func (xl xlObjects) AbortMultipartUpload(bucket, object, uploadID string) error {
-	return abortMultipartUploadCommon(xl.storage, bucket, object, uploadID)
-}

xl-objects.go

@@ -1,581 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 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 main
-
-import (
-	"crypto/md5"
-	"encoding/hex"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"path"
-	"path/filepath"
-	"strings"
-	"sync"
-
-	"github.com/minio/minio/pkg/mimedb"
-)
-
-const (
-	multipartSuffix   = ".minio.multipart"
-	multipartMetaFile = "00000" + multipartSuffix
-	formatConfigFile  = "format.json"
-)
-
-// xlObjects - Implements fs object layer.
-type xlObjects struct {
-	storage            StorageAPI
-	listObjectMap      map[listParams][]*treeWalker
-	listObjectMapMutex *sync.Mutex
-}
-
-// errMaxDisks - returned for reached maximum of disks.
-var errMaxDisks = errors.New("Number of disks are higher than supported maximum count '16'")
-
-// errMinDisks - returned for minimum number of disks.
-var errMinDisks = errors.New("Number of disks are smaller than supported minimum count '8'")
-
-// errNumDisks - returned for odd number of disks.
-var errNumDisks = errors.New("Number of disks should be multiples of '2'")
-
-const (
-	// Maximum erasure blocks.
-	maxErasureBlocks = 16
-	// Minimum erasure blocks.
-	minErasureBlocks = 8
-)
-
-func checkSufficientDisks(disks []string) error {
-	// Verify total number of disks.
-	totalDisks := len(disks)
-	if totalDisks > maxErasureBlocks {
-		return errMaxDisks
-	}
-	if totalDisks < minErasureBlocks {
-		return errMinDisks
-	}
-
-	// isEven function to verify if a given number if even.
-	isEven := func(number int) bool {
-		return number%2 == 0
-	}
-
-	// Verify if we have even number of disks.
-	// only combination of 8, 10, 12, 14, 16 are supported.
-	if !isEven(totalDisks) {
-		return errNumDisks
-	}
-
-	return nil
-}
-
-// Depending on the disk type network or local, initialize storage layer.
-func newStorageLayer(disk string) (storage StorageAPI, err error) {
-	if !strings.ContainsRune(disk, ':') || filepath.VolumeName(disk) != "" {
-		// Initialize filesystem storage API.
-		return newPosix(disk)
-	}
-	// Initialize rpc client storage API.
-	return newRPCClient(disk)
-}
-
-// Initialize all storage disks to bootstrap.
-func bootstrapDisks(disks []string) ([]StorageAPI, error) {
-	storageDisks := make([]StorageAPI, len(disks))
-	for index, disk := range disks {
-		var err error
-		// Intentionally ignore disk not found errors while
-		// initializing POSIX, so that we have successfully
-		// initialized posix Storage. Subsequent calls to XL/Erasure
-		// will manage any errors related to disks.
-		storageDisks[index], err = newStorageLayer(disk)
-		if err != nil && err != errDiskNotFound {
-			return nil, err
-		}
-	}
-	return storageDisks, nil
-}
-
-// newXLObjects - initialize new xl object layer.
-func newXLObjects(disks []string) (ObjectLayer, error) {
-	if err := checkSufficientDisks(disks); err != nil {
-		return nil, err
-	}
-
-	storageDisks, err := bootstrapDisks(disks)
-	if err != nil {
-		return nil, err
-	}
-
-	// Initialize object layer - like creating minioMetaBucket, cleaning up tmp files etc.
-	initObjectLayer(storageDisks...)
-
-	// Load saved XL format.json and validate.
-	newDisks, err := loadFormatXL(storageDisks)
-	if err != nil {
-		switch err {
-		case errUnformattedDisk:
-			// Save new XL format.
-			errSave := initFormatXL(storageDisks)
-			if errSave != nil {
-				return nil, errSave
-			}
-			newDisks = storageDisks
-		default:
-			// errCorruptedDisk - error.
-			return nil, fmt.Errorf("Unable to recognize backend format, %s", err)
-		}
-	}
-
-	// FIXME: healFormatXL(newDisks)
-
-	storage, err := newXL(newDisks)
-	if err != nil {
-		return nil, err
-	}
-
-	// Return successfully initialized object layer.
-	return xlObjects{
-		storage:            storage,
-		listObjectMap:      make(map[listParams][]*treeWalker),
-		listObjectMapMutex: &sync.Mutex{},
-	}, nil
-}
-
-/// Bucket operations
-
-// MakeBucket - make a bucket.
-func (xl xlObjects) MakeBucket(bucket string) error {
-	nsMutex.Lock(bucket, "")
-	defer nsMutex.Unlock(bucket, "")
-	return makeBucket(xl.storage, bucket)
-}
-
-// GetBucketInfo - get bucket info.
-func (xl xlObjects) GetBucketInfo(bucket string) (BucketInfo, error) {
-	nsMutex.RLock(bucket, "")
-	defer nsMutex.RUnlock(bucket, "")
-	return getBucketInfo(xl.storage, bucket)
-}
-
-// ListBuckets - list buckets.
-func (xl xlObjects) ListBuckets() ([]BucketInfo, error) {
-	return listBuckets(xl.storage)
-}
-
-// DeleteBucket - delete a bucket.
-func (xl xlObjects) DeleteBucket(bucket string) error {
-	nsMutex.Lock(bucket, "")
-	nsMutex.Unlock(bucket, "")
-	return deleteBucket(xl.storage, bucket)
-}
-
-/// Object Operations
-
-// GetObject - get an object.
-func (xl xlObjects) GetObject(bucket, object string, startOffset int64) (io.ReadCloser, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return nil, BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify if object is valid.
-	if !IsValidObjectName(object) {
-		return nil, ObjectNameInvalid{Bucket: bucket, Object: object}
-	}
-	nsMutex.RLock(bucket, object)
-	defer nsMutex.RUnlock(bucket, object)
-	if !isMultipartObject(xl.storage, bucket, object) {
-		_, err := xl.storage.StatFile(bucket, object)
-		if err == nil {
-			var reader io.ReadCloser
-			reader, err = xl.storage.ReadFile(bucket, object, startOffset)
-			if err != nil {
-				return nil, toObjectErr(err, bucket, object)
-			}
-			return reader, nil
-		}
-		return nil, toObjectErr(err, bucket, object)
-	}
-	fileReader, fileWriter := io.Pipe()
-	info, err := getMultipartObjectInfo(xl.storage, bucket, object)
-	if err != nil {
-		return nil, toObjectErr(err, bucket, object)
-	}
-	partIndex, offset, err := info.GetPartNumberOffset(startOffset)
-	if err != nil {
-		return nil, toObjectErr(err, bucket, object)
-	}
-
-	// Hold a read lock once more which can be released after the following go-routine ends.
-	// We hold RLock once more because the current function would return before the go routine below
-	// executes and hence releasing the read lock (because of defer'ed nsMutex.RUnlock() call).
-	nsMutex.RLock(bucket, object)
-	go func() {
-		defer nsMutex.RUnlock(bucket, object)
-		for ; partIndex < len(info.Parts); partIndex++ {
-			part := info.Parts[partIndex]
-			r, err := xl.storage.ReadFile(bucket, pathJoin(object, partNumToPartFileName(part.PartNumber)), offset)
-			if err != nil {
-				fileWriter.CloseWithError(err)
-				return
-			}
-			// Reset offset to 0 as it would be non-0 only for the first loop if startOffset is non-0.
-			offset = 0
-			if _, err = io.Copy(fileWriter, r); err != nil {
-				switch reader := r.(type) {
-				case *io.PipeReader:
-					reader.CloseWithError(err)
-				case io.ReadCloser:
-					reader.Close()
-				}
-				fileWriter.CloseWithError(err)
-				return
-			}
-			// Close the readerCloser that reads multiparts of an object from the xl storage layer.
-			// Not closing leaks underlying file descriptors.
-			r.Close()
-		}
-		fileWriter.Close()
-	}()
-	return fileReader, nil
-}
-
-// Return the partsInfo of a special multipart object.
-func getMultipartObjectInfo(storage StorageAPI, bucket, object string) (info MultipartObjectInfo, err error) {
-	offset := int64(0)
-	r, err := storage.ReadFile(bucket, pathJoin(object, multipartMetaFile), offset)
-	if err != nil {
-		return MultipartObjectInfo{}, err
-	}
-	decoder := json.NewDecoder(r)
-	err = decoder.Decode(&info)
-	if err != nil {
-		return MultipartObjectInfo{}, err
-	}
-	return info, nil
-}
-
-// Return ObjectInfo.
-func (xl xlObjects) getObjectInfo(bucket, object string) (objInfo ObjectInfo, err error) {
-	objInfo.Bucket = bucket
-	objInfo.Name = object
-	// First see if the object was a simple-PUT upload.
-	fi, err := xl.storage.StatFile(bucket, object)
-	if err != nil {
-		if err != errFileNotFound {
-			return ObjectInfo{}, err
-		}
-		var info MultipartObjectInfo
-		// Check if the object was multipart upload.
-		info, err = getMultipartObjectInfo(xl.storage, bucket, object)
-		if err != nil {
-			return ObjectInfo{}, err
-		}
-		objInfo.Size = info.Size
-		objInfo.ModTime = info.ModTime
-		objInfo.MD5Sum = info.MD5Sum
-		objInfo.ContentType = info.ContentType
-		objInfo.ContentEncoding = info.ContentEncoding
-	} else {
-		metadata := make(map[string]string)
-		offset := int64(0) // To read entire content
-		r, err := xl.storage.ReadFile(bucket, pathJoin(object, "meta.json"), offset)
-		if err != nil {
-			return ObjectInfo{}, toObjectErr(err, bucket, object)
-		}
-		decoder := json.NewDecoder(r)
-		if err = decoder.Decode(&metadata); err != nil {
-			return ObjectInfo{}, toObjectErr(err, bucket, object)
-		}
-		contentType := metadata["content-type"]
-		if len(contentType) == 0 {
-			contentType = "application/octet-stream"
-			if objectExt := filepath.Ext(object); objectExt != "" {
-				content, ok := mimedb.DB[strings.ToLower(strings.TrimPrefix(objectExt, "."))]
-				if ok {
-					contentType = content.ContentType
-				}
-			}
-		}
-		objInfo.Size = fi.Size
-		objInfo.IsDir = fi.Mode.IsDir()
-		objInfo.ModTime = fi.ModTime
-		objInfo.MD5Sum = metadata["md5Sum"]
-		objInfo.ContentType = contentType
-		objInfo.ContentEncoding = metadata["content-encoding"]
-	}
-	return objInfo, nil
-}
-
-// GetObjectInfo - get object info.
-func (xl xlObjects) GetObjectInfo(bucket, object string) (ObjectInfo, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return ObjectInfo{}, BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify if object is valid.
-	if !IsValidObjectName(object) {
-		return ObjectInfo{}, ObjectNameInvalid{Bucket: bucket, Object: object}
-	}
-	nsMutex.RLock(bucket, object)
-	defer nsMutex.RUnlock(bucket, object)
-	info, err := xl.getObjectInfo(bucket, object)
-	if err != nil {
-		return ObjectInfo{}, toObjectErr(err, bucket, object)
-	}
-	return info, nil
-}
-
-// PutObject - create an object.
-func (xl xlObjects) PutObject(bucket string, object string, size int64, data io.Reader, metadata map[string]string) (string, error) {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return "", BucketNameInvalid{Bucket: bucket}
-	}
-	// Verify bucket exists.
-	if !isBucketExist(xl.storage, bucket) {
-		return "", BucketNotFound{Bucket: bucket}
-	}
-	if !IsValidObjectName(object) {
-		return "", ObjectNameInvalid{
-			Bucket: bucket,
-			Object: object,
-		}
-	}
-	// No metadata is set, allocate a new one.
-	if metadata == nil {
-		metadata = make(map[string]string)
-	}
-	nsMutex.Lock(bucket, object)
-	defer nsMutex.Unlock(bucket, object)
-
-	tempObj := path.Join(tmpMetaPrefix, bucket, object)
-	fileWriter, err := xl.storage.CreateFile(minioMetaBucket, tempObj)
-	if err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Initialize md5 writer.
-	md5Writer := md5.New()
-
-	// Instantiate a new multi writer.
-	multiWriter := io.MultiWriter(md5Writer, fileWriter)
-
-	// Instantiate checksum hashers and create a multiwriter.
-	if size > 0 {
-		if _, err = io.CopyN(multiWriter, data, size); err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", toObjectErr(clErr, bucket, object)
-			}
-			return "", toObjectErr(err, bucket, object)
-		}
-	} else {
-		if _, err = io.Copy(multiWriter, data); err != nil {
-			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-				return "", toObjectErr(clErr, bucket, object)
-			}
-			return "", toObjectErr(err, bucket, object)
-		}
-	}
-
-	newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
-	// Update the md5sum if not set with the newly calculated one.
-	if len(metadata["md5Sum"]) == 0 {
-		metadata["md5Sum"] = newMD5Hex
-	}
-
-	// md5Hex representation.
-	md5Hex := metadata["md5Sum"]
-	if md5Hex != "" {
-		if newMD5Hex != md5Hex {
-			if err = safeCloseAndRemove(fileWriter); err != nil {
-				return "", toObjectErr(err, bucket, object)
-			}
-			return "", BadDigest{md5Hex, newMD5Hex}
-		}
-	}
-
-	err = fileWriter.Close()
-	if err != nil {
-		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
-			return "", toObjectErr(clErr, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Check if an object is present as one of the parent dir.
-	if err = xl.parentDirIsObject(bucket, path.Dir(object)); err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Delete if an object already exists.
-	// FIXME: rename it to tmp file and delete only after
-	// the newly uploaded file is renamed from tmp location to
-	// the original location.
-	// Verify if the object is a multipart object.
-	if isMultipartObject(xl.storage, bucket, object) {
-		err = xl.deleteMultipartObject(bucket, object)
-		if err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-	} else {
-		err = xl.deleteObject(bucket, object)
-		if err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-	}
-
-	err = xl.storage.RenameFile(minioMetaBucket, tempObj, bucket, object)
-	if err != nil {
-		if dErr := xl.storage.DeleteFile(minioMetaBucket, tempObj); dErr != nil {
-			return "", toObjectErr(dErr, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	tempMetaJSONFile := path.Join(tmpMetaPrefix, bucket, object, "meta.json")
-	metaWriter, err := xl.storage.CreateFile(minioMetaBucket, tempMetaJSONFile)
-	if err != nil {
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	encoder := json.NewEncoder(metaWriter)
-	err = encoder.Encode(&metadata)
-	if err != nil {
-		if clErr := safeCloseAndRemove(metaWriter); clErr != nil {
-			return "", toObjectErr(clErr, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-	if err = metaWriter.Close(); err != nil {
-		if err = safeCloseAndRemove(metaWriter); err != nil {
-			return "", toObjectErr(err, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	metaJSONFile := path.Join(object, "meta.json")
-	err = xl.storage.RenameFile(minioMetaBucket, tempMetaJSONFile, bucket, metaJSONFile)
-	if err != nil {
-		if derr := xl.storage.DeleteFile(minioMetaBucket, tempMetaJSONFile); derr != nil {
-			return "", toObjectErr(derr, bucket, object)
-		}
-		return "", toObjectErr(err, bucket, object)
-	}
-
-	// Return md5sum, successfully wrote object.
-	return newMD5Hex, nil
-}
-
-// isMultipartObject - verifies if an object is special multipart file.
-func isMultipartObject(storage StorageAPI, bucket, object string) bool {
-	_, err := storage.StatFile(bucket, pathJoin(object, multipartMetaFile))
-	if err != nil {
-		if err == errFileNotFound {
-			return false
-		}
-		errorIf(err, "Failed to stat file "+bucket+pathJoin(object, multipartMetaFile))
-		return false
-	}
-	return true
-}
-
-// deleteMultipartObject - deletes only multipart object.
-func (xl xlObjects) deleteMultipartObject(bucket, object string) error {
-	// Get parts info.
-	info, err := getMultipartObjectInfo(xl.storage, bucket, object)
-	if err != nil {
-		return err
-	}
-	// Range through all files and delete it.
-	var wg = &sync.WaitGroup{}
-	var errs = make([]error, len(info.Parts))
-	for index, part := range info.Parts {
-		wg.Add(1)
-		// Start deleting parts in routine.
-		go func(index int, part MultipartPartInfo) {
-			defer wg.Done()
-			partFileName := partNumToPartFileName(part.PartNumber)
-			errs[index] = xl.storage.DeleteFile(bucket, pathJoin(object, partFileName))
-		}(index, part)
-	}
-	// Wait for all the deletes to finish.
-	wg.Wait()
-	// Loop through and validate if any errors, if we are unable to remove any part return
-	// "unexpected" error as returning any other error might be misleading. For ex.
-	// if DeleteFile() had returned errFileNotFound and we return it, then client would see
-	// ObjectNotFound which is misleading.
-	for _, err := range errs {
-		if err != nil {
-			return errUnexpected
-		}
-	}
-	err = xl.storage.DeleteFile(bucket, pathJoin(object, multipartMetaFile))
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-// deleteObject - deletes a regular object.
-func (xl xlObjects) deleteObject(bucket, object string) error {
-	metaJSONFile := path.Join(object, "meta.json")
-	// Ignore if meta.json file doesn't exist.
-	if err := xl.storage.DeleteFile(bucket, metaJSONFile); err != nil {
-		if err != errFileNotFound {
-			return err
-		}
-	}
-	if err := xl.storage.DeleteFile(bucket, object); err != nil {
-		if err != errFileNotFound {
-			return err
-		}
-	}
-	return nil
-}
-
-// DeleteObject - delete the object.
-func (xl xlObjects) DeleteObject(bucket, object string) error {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return BucketNameInvalid{Bucket: bucket}
-	}
-	if !IsValidObjectName(object) {
-		return ObjectNameInvalid{Bucket: bucket, Object: object}
-	}
-	nsMutex.Lock(bucket, object)
-	defer nsMutex.Unlock(bucket, object)
-	// Verify if the object is a multipart object.
-	if isMultipartObject(xl.storage, bucket, object) {
-		err := xl.deleteMultipartObject(bucket, object)
-		if err != nil {
-			return toObjectErr(err, bucket, object)
-		}
-		return nil
-	}
-	err := xl.deleteObject(bucket, object)
-	if err != nil {
-		return toObjectErr(err, bucket, object)
-	}
-	return nil
-}
-
-// ListObjects - list all objects at prefix, delimited by '/'.
-func (xl xlObjects) ListObjects(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
-	return listObjectsCommon(xl, bucket, prefix, marker, delimiter, maxKeys)
-}

xl-v1-bucket.go

@@ -0,0 +1,355 @@
+package main
+
+import (
+	"sort"
+	"sync"
+)
+
+/// Bucket operations
+
+// MakeBucket - make a bucket.
+func (xl xlObjects) MakeBucket(bucket string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+
+	nsMutex.Lock(bucket, "")
+	defer nsMutex.Unlock(bucket, "")
+
+	// Err counters.
+	createVolErr := 0       // Count generic create vol errs.
+	volumeExistsErrCnt := 0 // Count all errVolumeExists errs.
+
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+
+	// Initialize list of errors.
+	var dErrs = make([]error, len(xl.storageDisks))
+
+	// Make a volume entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		wg.Add(1)
+		// Make a volume inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			err := disk.MakeVol(bucket)
+			if err != nil {
+				dErrs[index] = err
+				return
+			}
+			dErrs[index] = nil
+		}(index, disk)
+	}
+
+	// Wait for all make vol to finish.
+	wg.Wait()
+
+	// Loop through all the concocted errors.
+	for _, err := range dErrs {
+		if err == nil {
+			continue
+		}
+		// if volume already exists, count them.
+		if err == errVolumeExists {
+			volumeExistsErrCnt++
+			continue
+		}
+
+		// Update error counter separately.
+		createVolErr++
+	}
+
+	// Return err if all disks report volume exists.
+	if volumeExistsErrCnt == len(xl.storageDisks) {
+		return toObjectErr(errVolumeExists, bucket)
+	} else if createVolErr > len(xl.storageDisks)-xl.writeQuorum {
+		// Return errWriteQuorum if errors were more than
+		// allowed write quorum.
+		return toObjectErr(errWriteQuorum, bucket)
+	}
+	return nil
+}
+
+// getAllBucketInfo - list bucket info from all disks.
+// Returns error slice indicating the failed volume stat operations.
+func (xl xlObjects) getAllBucketInfo(bucketName string) ([]BucketInfo, []error) {
+	// Create errs and volInfo slices of storageDisks size.
+	var errs = make([]error, len(xl.storageDisks))
+	var volsInfo = make([]VolInfo, len(xl.storageDisks))
+
+	// Allocate a new waitgroup.
+	var wg = &sync.WaitGroup{}
+	for index, disk := range xl.storageDisks {
+		wg.Add(1)
+		// Stat volume on all the disks in a routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			volInfo, err := disk.StatVol(bucketName)
+			if err != nil {
+				errs[index] = err
+				return
+			}
+			volsInfo[index] = volInfo
+			errs[index] = nil
+		}(index, disk)
+	}
+
+	// Wait for all the Stat operations to finish.
+	wg.Wait()
+
+	// Return the concocted values.
+	var bucketsInfo = make([]BucketInfo, len(xl.storageDisks))
+	for _, volInfo := range volsInfo {
+		if IsValidBucketName(volInfo.Name) {
+			bucketsInfo = append(bucketsInfo, BucketInfo{
+				Name:    volInfo.Name,
+				Created: volInfo.Created,
+			})
+		}
+	}
+	return bucketsInfo, errs
+}
+
+// listAllBucketInfo - list all stat volume info from all disks.
+// Returns
+// - stat volume info for all online disks.
+// - boolean to indicate if healing is necessary.
+// - error if any.
+func (xl xlObjects) listAllBucketInfo(bucketName string) ([]BucketInfo, bool, error) {
+	bucketsInfo, errs := xl.getAllBucketInfo(bucketName)
+	notFoundCount := 0
+	for _, err := range errs {
+		if err == errVolumeNotFound {
+			notFoundCount++
+			// If we have errors with file not found greater than allowed read
+			// quorum we return err as errFileNotFound.
+			if notFoundCount > len(xl.storageDisks)-xl.readQuorum {
+				return nil, false, errVolumeNotFound
+			}
+		}
+	}
+
+	// Calculate online disk count.
+	onlineDiskCount := 0
+	for index := range errs {
+		if errs[index] == nil {
+			onlineDiskCount++
+		}
+	}
+
+	var heal bool
+	// If online disks count is lesser than configured disks, most
+	// probably we need to heal the file, additionally verify if the
+	// count is lesser than readQuorum, if not we throw an error.
+	if onlineDiskCount < len(xl.storageDisks) {
+		// Online disks lesser than total storage disks, needs to be
+		// healed. unless we do not have readQuorum.
+		heal = true
+		// Verify if online disks count are lesser than readQuorum
+		// threshold, return an error if yes.
+		if onlineDiskCount < xl.readQuorum {
+			return nil, false, errReadQuorum
+		}
+	}
+
+	// Return success.
+	return bucketsInfo, heal, nil
+}
+
+// Checks whether bucket exists.
+func (xl xlObjects) isBucketExist(bucketName string) bool {
+	// Check whether bucket exists.
+	_, _, err := xl.listAllBucketInfo(bucketName)
+	if err != nil {
+		if err == errVolumeNotFound {
+			return false
+		}
+		errorIf(err, "Stat failed on bucket "+bucketName+".")
+		return false
+	}
+	return true
+}
+
+// GetBucketInfo - get bucket info.
+func (xl xlObjects) GetBucketInfo(bucket string) (BucketInfo, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+
+	nsMutex.RLock(bucket, "")
+	defer nsMutex.RUnlock(bucket, "")
+
+	// List and figured out if we need healing.
+	bucketsInfo, heal, err := xl.listAllBucketInfo(bucket)
+	if err != nil {
+		return BucketInfo{}, toObjectErr(err, bucket)
+	}
+
+	// Heal for missing entries.
+	if heal {
+		go func() {
+			// Create bucket if missing on disks.
+			for index, bktInfo := range bucketsInfo {
+				if bktInfo.Name != "" {
+					continue
+				}
+				// Bucketinfo name would be an empty string, create it.
+				xl.storageDisks[index].MakeVol(bucket)
+			}
+		}()
+	}
+
+	// Loop through all statVols, calculate the actual usage values.
+	var total, free int64
+	var bucketInfo BucketInfo
+	for _, bucketInfo = range bucketsInfo {
+		if bucketInfo.Name == "" {
+			continue
+		}
+		free += bucketInfo.Free
+		total += bucketInfo.Total
+	}
+	// Update the aggregated values.
+	bucketInfo.Free = free
+	bucketInfo.Total = total
+
+	return BucketInfo{
+		Name:    bucket,
+		Created: bucketInfo.Created,
+		Total:   bucketInfo.Total,
+		Free:    bucketInfo.Free,
+	}, nil
+}
+
+func (xl xlObjects) listBuckets() ([]BucketInfo, error) {
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+
+	// Success vols map carries successful results of ListVols from each disks.
+	var successVols = make([][]VolInfo, len(xl.storageDisks))
+	for index, disk := range xl.storageDisks {
+		wg.Add(1) // Add each go-routine to wait for.
+		go func(index int, disk StorageAPI) {
+			// Indicate wait group as finished.
+			defer wg.Done()
+
+			// Initiate listing.
+			volsInfo, _ := disk.ListVols()
+			successVols[index] = volsInfo
+		}(index, disk)
+	}
+
+	// For all the list volumes running in parallel to finish.
+	wg.Wait()
+
+	// Loop through success vols and get aggregated usage values.
+	var volsInfo []VolInfo
+	var total, free int64
+	for _, volsInfo = range successVols {
+		var volInfo VolInfo
+		for _, volInfo = range volsInfo {
+			if volInfo.Name == "" {
+				continue
+			}
+			if !IsValidBucketName(volInfo.Name) {
+				continue
+			}
+			break
+		}
+		free += volInfo.Free
+		total += volInfo.Total
+	}
+
+	// Save the updated usage values back into the vols.
+	for index, volInfo := range volsInfo {
+		volInfo.Free = free
+		volInfo.Total = total
+		volsInfo[index] = volInfo
+	}
+
+	// NOTE: The assumption here is that volumes across all disks in
+	// readQuorum have consistent view i.e they all have same number
+	// of buckets. This is essentially not verified since healing
+	// should take care of this.
+	var bucketsInfo []BucketInfo
+	for _, volInfo := range volsInfo {
+		// StorageAPI can send volume names which are incompatible
+		// with buckets, handle it and skip them.
+		if !IsValidBucketName(volInfo.Name) {
+			continue
+		}
+		bucketsInfo = append(bucketsInfo, BucketInfo{
+			Name:    volInfo.Name,
+			Created: volInfo.Created,
+			Total:   volInfo.Total,
+			Free:    volInfo.Free,
+		})
+	}
+	return bucketsInfo, nil
+}
+
+// ListBuckets - list buckets.
+func (xl xlObjects) ListBuckets() ([]BucketInfo, error) {
+	bucketInfos, err := xl.listBuckets()
+	if err != nil {
+		return nil, toObjectErr(err)
+	}
+	sort.Sort(byBucketName(bucketInfos))
+	return bucketInfos, nil
+}
+
+// DeleteBucket - delete a bucket.
+func (xl xlObjects) DeleteBucket(bucket string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+
+	nsMutex.Lock(bucket, "")
+	nsMutex.Unlock(bucket, "")
+
+	// Collect if all disks report volume not found.
+	var volumeNotFoundErrCnt int
+
+	var wg = &sync.WaitGroup{}
+	var dErrs = make([]error, len(xl.storageDisks))
+
+	// Remove a volume entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		wg.Add(1)
+		// Delete volume inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			err := disk.DeleteVol(bucket)
+			if err != nil {
+				dErrs[index] = err
+				return
+			}
+			dErrs[index] = nil
+		}(index, disk)
+	}
+
+	// Wait for all the delete vols to finish.
+	wg.Wait()
+
+	// Loop through concocted errors and return anything unusual.
+	for _, err := range dErrs {
+		if err != nil {
+			// We ignore error if errVolumeNotFound or errDiskNotFound
+			if err == errVolumeNotFound || err == errDiskNotFound {
+				volumeNotFoundErrCnt++
+				continue
+			}
+			return toObjectErr(err, bucket)
+		}
+	}
+
+	// Return err if all disks report volume not found.
+	if volumeNotFoundErrCnt == len(xl.storageDisks) {
+		return toObjectErr(errVolumeNotFound, bucket)
+	}
+
+	return nil
+}

xl-v1-list-objects.go

@@ -0,0 +1,116 @@
+package main
+
+import "strings"
+
+func (xl xlObjects) listObjectsXL(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
+	// Default is recursive, if delimiter is set then list non recursive.
+	recursive := true
+	if delimiter == slashSeparator {
+		recursive = false
+	}
+
+	walker := xl.lookupTreeWalkXL(listParams{bucket, recursive, marker, prefix})
+	if walker == nil {
+		walker = xl.startTreeWalkXL(bucket, prefix, marker, recursive)
+	}
+	var objInfos []ObjectInfo
+	var eof bool
+	var nextMarker string
+	for i := 0; i < maxKeys; {
+		walkResult, ok := <-walker.ch
+		if !ok {
+			// Closed channel.
+			eof = true
+			break
+		}
+		// For any walk error return right away.
+		if walkResult.err != nil {
+			// File not found is a valid case.
+			if walkResult.err == errFileNotFound {
+				return ListObjectsInfo{}, nil
+			}
+			return ListObjectsInfo{}, toObjectErr(walkResult.err, bucket, prefix)
+		}
+		objInfo := walkResult.objInfo
+		nextMarker = objInfo.Name
+		objInfos = append(objInfos, objInfo)
+		if walkResult.end {
+			eof = true
+			break
+		}
+		i++
+	}
+	params := listParams{bucket, recursive, nextMarker, prefix}
+	if !eof {
+		xl.saveTreeWalkXL(params, walker)
+	}
+
+	result := ListObjectsInfo{IsTruncated: !eof}
+	for _, objInfo := range objInfos {
+		// With delimiter set we fill in NextMarker and Prefixes.
+		if delimiter == slashSeparator {
+			result.NextMarker = objInfo.Name
+			if objInfo.IsDir {
+				result.Prefixes = append(result.Prefixes, objInfo.Name)
+				continue
+			}
+		}
+		result.Objects = append(result.Objects, ObjectInfo{
+			Name:    objInfo.Name,
+			ModTime: objInfo.ModTime,
+			Size:    objInfo.Size,
+			IsDir:   false,
+		})
+	}
+	return result, nil
+}
+
+// ListObjects - list all objects at prefix, delimited by '/'.
+func (xl xlObjects) ListObjects(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return ListObjectsInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify if bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return ListObjectsInfo{}, BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectPrefix(prefix) {
+		return ListObjectsInfo{}, ObjectNameInvalid{Bucket: bucket, Object: prefix}
+	}
+	// Verify if delimiter is anything other than '/', which we do not support.
+	if delimiter != "" && delimiter != slashSeparator {
+		return ListObjectsInfo{}, UnsupportedDelimiter{
+			Delimiter: delimiter,
+		}
+	}
+	// Verify if marker has prefix.
+	if marker != "" {
+		if !strings.HasPrefix(marker, prefix) {
+			return ListObjectsInfo{}, InvalidMarkerPrefixCombination{
+				Marker: marker,
+				Prefix: prefix,
+			}
+		}
+	}
+
+	// With max keys of zero we have reached eof, return right here.
+	if maxKeys == 0 {
+		return ListObjectsInfo{}, nil
+	}
+
+	// Over flowing count - reset to maxObjectList.
+	if maxKeys < 0 || maxKeys > maxObjectList {
+		maxKeys = maxObjectList
+	}
+
+	// Initiate a list operation, if successful filter and return quickly.
+	listObjInfo, err := xl.listObjectsXL(bucket, prefix, marker, delimiter, maxKeys)
+	if err == nil {
+		// We got the entries successfully return.
+		return listObjInfo, nil
+	}
+
+	// Return error at the end.
+	return ListObjectsInfo{}, toObjectErr(err, bucket, prefix)
+}

xl-v1-metadata.go

@@ -0,0 +1,287 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"path"
+	"sort"
+	"sync"
+	"time"
+)
+
+// Erasure block size.
+const erasureBlockSize = 4 * 1024 * 1024 // 4MiB.
+
+// objectPartInfo Info of each part kept in the multipart metadata
+// file after CompleteMultipartUpload() is called.
+type objectPartInfo struct {
+	Name string `json:"name"`
+	ETag string `json:"etag"`
+	Size int64  `json:"size"`
+}
+
+// A xlMetaV1 represents a metadata header mapping keys to sets of values.
+type xlMetaV1 struct {
+	Version string `json:"version"`
+	Format  string `json:"format"`
+	Stat    struct {
+		Size    int64     `json:"size"`
+		ModTime time.Time `json:"modTime"`
+		Version int64     `json:"version"`
+	} `json:"stat"`
+	Erasure struct {
+		DataBlocks   int   `json:"data"`
+		ParityBlocks int   `json:"parity"`
+		BlockSize    int64 `json:"blockSize"`
+		Index        int   `json:"index"`
+		Distribution []int `json:"distribution"`
+	} `json:"erasure"`
+	Checksum struct {
+		Enable bool `json:"enable"`
+	} `json:"checksum"`
+	Minio struct {
+		Release string `json:"release"`
+	} `json:"minio"`
+	Meta  map[string]string `json:"meta"`
+	Parts []objectPartInfo  `json:"parts,omitempty"`
+}
+
+// ReadFrom - read from implements io.ReaderFrom interface for
+// unmarshalling xlMetaV1.
+func (m *xlMetaV1) ReadFrom(reader io.Reader) (n int64, err error) {
+	var buffer bytes.Buffer
+	n, err = buffer.ReadFrom(reader)
+	if err != nil {
+		return 0, err
+	}
+	err = json.Unmarshal(buffer.Bytes(), m)
+	return n, err
+}
+
+// WriteTo - write to implements io.WriterTo interface for marshalling xlMetaV1.
+func (m xlMetaV1) WriteTo(writer io.Writer) (n int64, err error) {
+	metadataBytes, err := json.Marshal(m)
+	if err != nil {
+		return 0, err
+	}
+	p, err := writer.Write(metadataBytes)
+	return int64(p), err
+}
+
+// byPartName is a collection satisfying sort.Interface.
+type byPartName []objectPartInfo
+
+func (t byPartName) Len() int           { return len(t) }
+func (t byPartName) Swap(i, j int)      { t[i], t[j] = t[j], t[i] }
+func (t byPartName) Less(i, j int) bool { return t[i].Name < t[j].Name }
+
+// SearchObjectPart - searches for part name and etag, returns the
+// index if found.
+func (m xlMetaV1) SearchObjectPart(name string, etag string) int {
+	for i, part := range m.Parts {
+		if name == part.Name && etag == part.ETag {
+			return i
+		}
+	}
+	return -1
+}
+
+// AddObjectPart - add a new object part in order.
+func (m *xlMetaV1) AddObjectPart(name string, etag string, size int64) {
+	m.Parts = append(m.Parts, objectPartInfo{
+		Name: name,
+		ETag: etag,
+		Size: size,
+	})
+	sort.Sort(byPartName(m.Parts))
+}
+
+// getPartNumberOffset - given an offset for the whole object, return the part and offset in that part.
+func (m xlMetaV1) getPartNumberOffset(offset int64) (partNumber int, partOffset int64, err error) {
+	partOffset = offset
+	for i, part := range m.Parts {
+		partNumber = i
+		if part.Size == 0 {
+			return partNumber, partOffset, nil
+		}
+		if partOffset < part.Size {
+			return partNumber, partOffset, nil
+		}
+		partOffset -= part.Size
+	}
+	// Offset beyond the size of the object
+	err = errUnexpected
+	return 0, 0, err
+}
+
+// This function does the following check, suppose
+// object is "a/b/c/d", stat makes sure that objects ""a/b/c""
+// "a/b" and "a" do not exist.
+func (xl xlObjects) parentDirIsObject(bucket, parent string) bool {
+	var isParentDirObject func(string) bool
+	isParentDirObject = func(p string) bool {
+		if p == "." {
+			return false
+		}
+		if xl.isObject(bucket, p) {
+			// If there is already a file at prefix "p" return error.
+			return true
+		}
+		// Check if there is a file as one of the parent paths.
+		return isParentDirObject(path.Dir(p))
+	}
+	return isParentDirObject(parent)
+}
+
+func (xl xlObjects) isObject(bucket, prefix string) bool {
+	// Create errs and volInfo slices of storageDisks size.
+	var errs = make([]error, len(xl.storageDisks))
+
+	// Allocate a new waitgroup.
+	var wg = &sync.WaitGroup{}
+	for index, disk := range xl.storageDisks {
+		wg.Add(1)
+		// Stat file on all the disks in a routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			_, err := disk.StatFile(bucket, path.Join(prefix, xlMetaJSONFile))
+			if err != nil {
+				errs[index] = err
+				return
+			}
+			errs[index] = nil
+		}(index, disk)
+	}
+
+	// Wait for all the Stat operations to finish.
+	wg.Wait()
+
+	var errFileNotFoundCount int
+	for _, err := range errs {
+		if err != nil {
+			if err == errFileNotFound {
+				errFileNotFoundCount++
+				// If we have errors with file not found greater than allowed read
+				// quorum we return err as errFileNotFound.
+				if errFileNotFoundCount > len(xl.storageDisks)-xl.readQuorum {
+					return false
+				}
+				continue
+			}
+			errorIf(err, "Unable to access file "+path.Join(bucket, prefix))
+			return false
+		}
+	}
+	return true
+}
+
+// readXLMetadata - read xl metadata.
+func readXLMetadata(disk StorageAPI, bucket, object string) (xlMeta xlMetaV1, err error) {
+	r, err := disk.ReadFile(bucket, path.Join(object, xlMetaJSONFile), int64(0))
+	if err != nil {
+		return xlMetaV1{}, err
+	}
+	defer r.Close()
+	_, err = xlMeta.ReadFrom(r)
+	if err != nil {
+		return xlMetaV1{}, err
+	}
+	return xlMeta, nil
+}
+
+// deleteXLJson - delete `xl.json` on all disks.
+func (xl xlObjects) deleteXLMetadata(bucket, object string) error {
+	return xl.deleteObject(bucket, path.Join(object, xlMetaJSONFile))
+}
+
+// renameXLJson - rename `xl.json` on all disks.
+func (xl xlObjects) renameXLMetadata(srcBucket, srcPrefix, dstBucket, dstPrefix string) error {
+	return xl.renameObject(srcBucket, path.Join(srcPrefix, xlMetaJSONFile), dstBucket, path.Join(dstPrefix, xlMetaJSONFile))
+}
+
+// getDiskDistribution - get disk distribution.
+func (xl xlObjects) getDiskDistribution() []int {
+	var distribution = make([]int, len(xl.storageDisks))
+	for index := range xl.storageDisks {
+		distribution[index] = index + 1
+	}
+	return distribution
+}
+
+// writeXLJson - write `xl.json` on all disks in order.
+func (xl xlObjects) writeXLMetadata(bucket, prefix string, xlMeta xlMetaV1) error {
+	var wg = &sync.WaitGroup{}
+	var mErrs = make([]error, len(xl.storageDisks))
+
+	// Initialize metadata map, save all erasure related metadata.
+	xlMeta.Minio.Release = minioReleaseTag
+	xlMeta.Erasure.DataBlocks = xl.dataBlocks
+	xlMeta.Erasure.ParityBlocks = xl.parityBlocks
+	xlMeta.Erasure.BlockSize = erasureBlockSize
+	xlMeta.Erasure.Distribution = xl.getDiskDistribution()
+
+	for index, disk := range xl.storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI, metadata xlMetaV1) {
+			defer wg.Done()
+
+			metaJSONFile := path.Join(prefix, xlMetaJSONFile)
+			metaWriter, mErr := disk.CreateFile(bucket, metaJSONFile)
+			if mErr != nil {
+				mErrs[index] = mErr
+				return
+			}
+
+			// Save the order.
+			metadata.Erasure.Index = index + 1
+			_, mErr = metadata.WriteTo(metaWriter)
+			if mErr != nil {
+				if mErr = safeCloseAndRemove(metaWriter); mErr != nil {
+					mErrs[index] = mErr
+					return
+				}
+				mErrs[index] = mErr
+				return
+			}
+			if mErr = metaWriter.Close(); mErr != nil {
+				if mErr = safeCloseAndRemove(metaWriter); mErr != nil {
+					mErrs[index] = mErr
+					return
+				}
+				mErrs[index] = mErr
+				return
+			}
+			mErrs[index] = nil
+		}(index, disk, xlMeta)
+	}
+
+	// Wait for all the routines.
+	wg.Wait()
+
+	// FIXME: check for quorum.
+	// Loop through concocted errors and return the first one.
+	for _, err := range mErrs {
+		if err == nil {
+			continue
+		}
+		return err
+	}
+	return nil
+}

xl-v1-multipart-common.go

@@ -0,0 +1,474 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"path"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/skyrings/skyring-common/tools/uuid"
+)
+
+// uploadInfo -
+type uploadInfo struct {
+	UploadID  string    `json:"uploadId"`
+	Initiated time.Time `json:"initiated"`
+}
+
+// uploadsV1 -
+type uploadsV1 struct {
+	Version string       `json:"version"`
+	Format  string       `json:"format"`
+	Uploads []uploadInfo `json:"uploadIds"`
+}
+
+// byInitiatedTime is a collection satisfying sort.Interface.
+type byInitiatedTime []uploadInfo
+
+func (t byInitiatedTime) Len() int      { return len(t) }
+func (t byInitiatedTime) Swap(i, j int) { t[i], t[j] = t[j], t[i] }
+func (t byInitiatedTime) Less(i, j int) bool {
+	return t[i].Initiated.After(t[j].Initiated)
+}
+
+// AddUploadID - adds a new upload id in order of its initiated time.
+func (u *uploadsV1) AddUploadID(uploadID string, initiated time.Time) {
+	u.Uploads = append(u.Uploads, uploadInfo{
+		UploadID:  uploadID,
+		Initiated: initiated,
+	})
+	sort.Sort(byInitiatedTime(u.Uploads))
+}
+
+func (u uploadsV1) SearchUploadID(uploadID string) int {
+	for i, u := range u.Uploads {
+		if u.UploadID == uploadID {
+			return i
+		}
+	}
+	return -1
+}
+
+// ReadFrom - read from implements io.ReaderFrom interface for unmarshalling uploads.
+func (u *uploadsV1) ReadFrom(reader io.Reader) (n int64, err error) {
+	var buffer bytes.Buffer
+	n, err = buffer.ReadFrom(reader)
+	if err != nil {
+		return 0, err
+	}
+	err = json.Unmarshal(buffer.Bytes(), &u)
+	return n, err
+}
+
+// WriteTo - write to implements io.WriterTo interface for marshalling uploads.
+func (u uploadsV1) WriteTo(writer io.Writer) (n int64, err error) {
+	metadataBytes, err := json.Marshal(u)
+	if err != nil {
+		return 0, err
+	}
+	m, err := writer.Write(metadataBytes)
+	return int64(m), err
+}
+
+// getUploadIDs - get saved upload id's.
+func getUploadIDs(bucket, object string, storageDisks ...StorageAPI) (uploadIDs uploadsV1, err error) {
+	uploadJSONPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
+	var errs = make([]error, len(storageDisks))
+	var uploads = make([]uploadsV1, len(storageDisks))
+	var wg = &sync.WaitGroup{}
+
+	for index, disk := range storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			r, rErr := disk.ReadFile(minioMetaBucket, uploadJSONPath, int64(0))
+			if rErr != nil {
+				errs[index] = rErr
+				return
+			}
+			defer r.Close()
+			_, rErr = uploads[index].ReadFrom(r)
+			if rErr != nil {
+				errs[index] = rErr
+				return
+			}
+			errs[index] = nil
+		}(index, disk)
+	}
+	wg.Wait()
+
+	for _, err = range errs {
+		if err != nil {
+			return uploadsV1{}, err
+		}
+	}
+
+	// FIXME: Do not know if it should pick the picks the first successful one and returns.
+	return uploads[0], nil
+}
+
+func updateUploadJSON(bucket, object string, uploadIDs uploadsV1, storageDisks ...StorageAPI) error {
+	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
+	var errs = make([]error, len(storageDisks))
+	var wg = &sync.WaitGroup{}
+
+	for index, disk := range storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			w, wErr := disk.CreateFile(minioMetaBucket, uploadsPath)
+			if wErr != nil {
+				errs[index] = wErr
+				return
+			}
+			_, wErr = uploadIDs.WriteTo(w)
+			if wErr != nil {
+				errs[index] = wErr
+				return
+			}
+			if wErr = w.Close(); wErr != nil {
+				if clErr := safeCloseAndRemove(w); clErr != nil {
+					errs[index] = clErr
+					return
+				}
+				errs[index] = wErr
+				return
+			}
+		}(index, disk)
+	}
+
+	wg.Wait()
+
+	for _, err := range errs {
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// writeUploadJSON - create `uploads.json` or update it with new uploadID.
+func writeUploadJSON(bucket, object, uploadID string, initiated time.Time, storageDisks ...StorageAPI) error {
+	uploadsPath := path.Join(mpartMetaPrefix, bucket, object, uploadsJSONFile)
+	tmpUploadsPath := path.Join(tmpMetaPrefix, bucket, object, uploadsJSONFile)
+
+	var errs = make([]error, len(storageDisks))
+	var wg = &sync.WaitGroup{}
+
+	uploadIDs, err := getUploadIDs(bucket, object, storageDisks...)
+	if err != nil && err != errFileNotFound {
+		return err
+	}
+	uploadIDs.Version = "1"
+	uploadIDs.Format = "xl"
+	uploadIDs.AddUploadID(uploadID, initiated)
+
+	for index, disk := range storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			w, wErr := disk.CreateFile(minioMetaBucket, tmpUploadsPath)
+			if wErr != nil {
+				errs[index] = wErr
+				return
+			}
+			_, wErr = uploadIDs.WriteTo(w)
+			if wErr != nil {
+				errs[index] = wErr
+				return
+			}
+			if wErr = w.Close(); wErr != nil {
+				if clErr := safeCloseAndRemove(w); clErr != nil {
+					errs[index] = clErr
+					return
+				}
+				errs[index] = wErr
+				return
+			}
+
+			_, wErr = disk.StatFile(minioMetaBucket, uploadsPath)
+			if wErr != nil {
+				if wErr == errFileNotFound {
+					wErr = disk.RenameFile(minioMetaBucket, tmpUploadsPath, minioMetaBucket, uploadsPath)
+					if wErr == nil {
+						return
+					}
+				}
+				if dErr := disk.DeleteFile(minioMetaBucket, tmpUploadsPath); dErr != nil {
+					errs[index] = dErr
+					return
+				}
+				errs[index] = wErr
+				return
+			}
+		}(index, disk)
+	}
+
+	wg.Wait()
+
+	for _, err = range errs {
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Wrapper which removes all the uploaded parts.
+func cleanupUploadedParts(bucket, object, uploadID string, storageDisks ...StorageAPI) error {
+	var errs = make([]error, len(storageDisks))
+	var wg = &sync.WaitGroup{}
+	for index, disk := range storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			err := cleanupDir(disk, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
+			if err != nil {
+				errs[index] = err
+				return
+			}
+			errs[index] = nil
+		}(index, disk)
+	}
+	wg.Wait()
+
+	for _, err := range errs {
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// listUploadsInfo - list all uploads info.
+func (xl xlObjects) listUploadsInfo(prefixPath string) (uploads []uploadInfo, err error) {
+	disk := xl.getRandomDisk()
+	splitPrefixes := strings.SplitN(prefixPath, "/", 3)
+	uploadIDs, err := getUploadIDs(splitPrefixes[1], splitPrefixes[2], disk)
+	if err != nil {
+		if err == errFileNotFound {
+			return []uploadInfo{}, nil
+		}
+		return nil, err
+	}
+	uploads = uploadIDs.Uploads
+	return uploads, nil
+}
+
+// listMetaBucketMultipart - list all objects at a given prefix inside minioMetaBucket.
+func (xl xlObjects) listMetaBucketMultipart(prefixPath string, markerPath string, recursive bool, maxKeys int) (objInfos []ObjectInfo, eof bool, err error) {
+	walker := xl.lookupTreeWalkXL(listParams{minioMetaBucket, recursive, markerPath, prefixPath})
+	if walker == nil {
+		walker = xl.startTreeWalkXL(minioMetaBucket, prefixPath, markerPath, recursive)
+	}
+
+	// newMaxKeys tracks the size of entries which are going to be
+	// returned back.
+	var newMaxKeys int
+
+	// Following loop gathers and filters out special files inside minio meta volume.
+	for {
+		walkResult, ok := <-walker.ch
+		if !ok {
+			// Closed channel.
+			eof = true
+			break
+		}
+		// For any walk error return right away.
+		if walkResult.err != nil {
+			// File not found or Disk not found is a valid case.
+			if walkResult.err == errFileNotFound || walkResult.err == errDiskNotFound {
+				return nil, true, nil
+			}
+			return nil, false, toObjectErr(walkResult.err, minioMetaBucket, prefixPath)
+		}
+		objInfo := walkResult.objInfo
+		var uploads []uploadInfo
+		if objInfo.IsDir {
+			// List all the entries if fi.Name is a leaf directory, if
+			// fi.Name is not a leaf directory then the resulting
+			// entries are empty.
+			uploads, err = xl.listUploadsInfo(objInfo.Name)
+			if err != nil {
+				return nil, false, err
+			}
+		}
+		if len(uploads) > 0 {
+			for _, upload := range uploads {
+				objInfos = append(objInfos, ObjectInfo{
+					Name:    path.Join(objInfo.Name, upload.UploadID),
+					ModTime: upload.Initiated,
+				})
+				newMaxKeys++
+				// If we have reached the maxKeys, it means we have listed
+				// everything that was requested.
+				if newMaxKeys == maxKeys {
+					break
+				}
+			}
+		} else {
+			// We reach here for a non-recursive case non-leaf entry
+			// OR recursive case with fi.Name.
+			if !objInfo.IsDir { // Do not skip non-recursive case directory entries.
+				// Validate if 'fi.Name' is incomplete multipart.
+				if !strings.HasSuffix(objInfo.Name, xlMetaJSONFile) {
+					continue
+				}
+				objInfo.Name = path.Dir(objInfo.Name)
+			}
+			objInfos = append(objInfos, objInfo)
+			newMaxKeys++
+			// If we have reached the maxKeys, it means we have listed
+			// everything that was requested.
+			if newMaxKeys == maxKeys {
+				break
+			}
+		}
+	}
+
+	if !eof && len(objInfos) != 0 {
+		// EOF has not reached, hence save the walker channel to the map so that the walker go routine
+		// can continue from where it left off for the next list request.
+		lastObjInfo := objInfos[len(objInfos)-1]
+		markerPath = lastObjInfo.Name
+		xl.saveTreeWalkXL(listParams{minioMetaBucket, recursive, markerPath, prefixPath}, walker)
+	}
+
+	// Return entries here.
+	return objInfos, eof, nil
+}
+
+// FIXME: Currently the code sorts based on keyName/upload-id which is
+// not correct based on the S3 specs. According to s3 specs we are
+// supposed to only lexically sort keyNames and then for keyNames with
+// multiple upload ids should be sorted based on the initiated time.
+// Currently this case is not handled.
+
+// listMultipartUploadsCommon - lists all multipart uploads, common
+// function for both object layers.
+func (xl xlObjects) listMultipartUploadsCommon(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
+	result := ListMultipartsInfo{}
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return ListMultipartsInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	if !xl.isBucketExist(bucket) {
+		return ListMultipartsInfo{}, BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectPrefix(prefix) {
+		return ListMultipartsInfo{}, ObjectNameInvalid{Bucket: bucket, Object: prefix}
+	}
+	// Verify if delimiter is anything other than '/', which we do not support.
+	if delimiter != "" && delimiter != slashSeparator {
+		return ListMultipartsInfo{}, UnsupportedDelimiter{
+			Delimiter: delimiter,
+		}
+	}
+	// Verify if marker has prefix.
+	if keyMarker != "" && !strings.HasPrefix(keyMarker, prefix) {
+		return ListMultipartsInfo{}, InvalidMarkerPrefixCombination{
+			Marker: keyMarker,
+			Prefix: prefix,
+		}
+	}
+	if uploadIDMarker != "" {
+		if strings.HasSuffix(keyMarker, slashSeparator) {
+			return result, InvalidUploadIDKeyCombination{
+				UploadIDMarker: uploadIDMarker,
+				KeyMarker:      keyMarker,
+			}
+		}
+		id, err := uuid.Parse(uploadIDMarker)
+		if err != nil {
+			return result, err
+		}
+		if id.IsZero() {
+			return result, MalformedUploadID{
+				UploadID: uploadIDMarker,
+			}
+		}
+	}
+
+	recursive := true
+	if delimiter == slashSeparator {
+		recursive = false
+	}
+
+	result.IsTruncated = true
+	result.MaxUploads = maxUploads
+
+	// Not using path.Join() as it strips off the trailing '/'.
+	multipartPrefixPath := pathJoin(mpartMetaPrefix, pathJoin(bucket, prefix))
+	if prefix == "" {
+		// Should have a trailing "/" if prefix is ""
+		// For ex. multipartPrefixPath should be "multipart/bucket/" if prefix is ""
+		multipartPrefixPath += slashSeparator
+	}
+	multipartMarkerPath := ""
+	if keyMarker != "" {
+		keyMarkerPath := pathJoin(pathJoin(bucket, keyMarker), uploadIDMarker)
+		multipartMarkerPath = pathJoin(mpartMetaPrefix, keyMarkerPath)
+	}
+
+	// List all the multipart files at prefixPath, starting with marker keyMarkerPath.
+	objInfos, eof, err := xl.listMetaBucketMultipart(multipartPrefixPath, multipartMarkerPath, recursive, maxUploads)
+	if err != nil {
+		return ListMultipartsInfo{}, err
+	}
+
+	// Loop through all the received files fill in the multiparts result.
+	for _, objInfo := range objInfos {
+		var objectName string
+		var uploadID string
+		if objInfo.IsDir {
+			// All directory entries are common prefixes.
+			uploadID = "" // Upload ids are empty for CommonPrefixes.
+			objectName = strings.TrimPrefix(objInfo.Name, retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			result.CommonPrefixes = append(result.CommonPrefixes, objectName)
+		} else {
+			uploadID = path.Base(objInfo.Name)
+			objectName = strings.TrimPrefix(path.Dir(objInfo.Name), retainSlash(pathJoin(mpartMetaPrefix, bucket)))
+			result.Uploads = append(result.Uploads, uploadMetadata{
+				Object:    objectName,
+				UploadID:  uploadID,
+				Initiated: objInfo.ModTime,
+			})
+		}
+		result.NextKeyMarker = objectName
+		result.NextUploadIDMarker = uploadID
+	}
+	result.IsTruncated = !eof
+	if !result.IsTruncated {
+		result.NextKeyMarker = ""
+		result.NextUploadIDMarker = ""
+	}
+	return result, nil
+}
+
+// isUploadIDExists - verify if a given uploadID exists and is valid.
+func (xl xlObjects) isUploadIDExists(bucket, object, uploadID string) bool {
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	return xl.isObject(minioMetaBucket, uploadIDPath)
+}

xl-v1-multipart.go

@@ -0,0 +1,432 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path"
+	"strconv"
+	"time"
+)
+
+// ListMultipartUploads - list multipart uploads.
+func (xl xlObjects) ListMultipartUploads(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, maxUploads int) (ListMultipartsInfo, error) {
+	return xl.listMultipartUploadsCommon(bucket, prefix, keyMarker, uploadIDMarker, delimiter, maxUploads)
+}
+
+/// Common multipart object layer functions.
+
+// newMultipartUploadCommon - initialize a new multipart, is a common function for both object layers.
+func (xl xlObjects) newMultipartUploadCommon(bucket string, object string, meta map[string]string) (uploadID string, err error) {
+	// Verify if bucket name is valid.
+	if !IsValidBucketName(bucket) {
+		return "", BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify whether the bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return "", BucketNotFound{Bucket: bucket}
+	}
+	// Verify if object name is valid.
+	if !IsValidObjectName(object) {
+		return "", ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	// No metadata is set, allocate a new one.
+	if meta == nil {
+		meta = make(map[string]string)
+	}
+
+	xlMeta := xlMetaV1{}
+	xlMeta.Format = "xl"
+	xlMeta.Version = "1"
+	// If not set default to "application/octet-stream"
+	if meta["content-type"] == "" {
+		meta["content-type"] = "application/octet-stream"
+	}
+	xlMeta.Meta = meta
+
+	// This lock needs to be held for any changes to the directory contents of ".minio/multipart/object/"
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
+
+	uploadID = getUUID()
+	initiated := time.Now().UTC()
+	// Create 'uploads.json'
+	if err = writeUploadJSON(bucket, object, uploadID, initiated, xl.storageDisks...); err != nil {
+		return "", err
+	}
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	tempUploadIDPath := path.Join(tmpMetaPrefix, bucket, object, uploadID)
+	if err = xl.writeXLMetadata(minioMetaBucket, tempUploadIDPath, xlMeta); err != nil {
+		return "", toObjectErr(err, minioMetaBucket, tempUploadIDPath)
+	}
+	if err = xl.renameXLMetadata(minioMetaBucket, tempUploadIDPath, minioMetaBucket, uploadIDPath); err != nil {
+		if dErr := xl.deleteXLMetadata(minioMetaBucket, tempUploadIDPath); dErr != nil {
+			return "", toObjectErr(dErr, minioMetaBucket, tempUploadIDPath)
+		}
+		return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
+	}
+	// Return success.
+	return uploadID, nil
+}
+
+// NewMultipartUpload - initialize a new multipart upload, returns a unique id.
+func (xl xlObjects) NewMultipartUpload(bucket, object string, meta map[string]string) (string, error) {
+	return xl.newMultipartUploadCommon(bucket, object, meta)
+}
+
+// putObjectPartCommon - put object part.
+func (xl xlObjects) putObjectPartCommon(bucket string, object string, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return "", BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify whether the bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return "", BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return "", ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	if !xl.isUploadIDExists(bucket, object, uploadID) {
+		return "", InvalidUploadID{UploadID: uploadID}
+	}
+	// Hold read lock on the uploadID so that no one aborts it.
+	nsMutex.RLock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	defer nsMutex.RUnlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+
+	// Hold write lock on the part so that there is no parallel upload on the part.
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID, strconv.Itoa(partID)))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID, strconv.Itoa(partID)))
+
+	partSuffix := fmt.Sprintf("object%d", partID)
+	tmpPartPath := path.Join(tmpMetaPrefix, bucket, object, uploadID, partSuffix)
+	fileWriter, err := xl.erasureDisk.CreateFile(minioMetaBucket, tmpPartPath)
+	if err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Initialize md5 writer.
+	md5Writer := md5.New()
+
+	// Instantiate a new multi writer.
+	multiWriter := io.MultiWriter(md5Writer, fileWriter)
+
+	// Instantiate checksum hashers and create a multiwriter.
+	if size > 0 {
+		if _, err = io.CopyN(multiWriter, data, size); err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", toObjectErr(err, bucket, object)
+		}
+		// Reader shouldn't have more data what mentioned in size argument.
+		// reading one more byte from the reader to validate it.
+		// expected to fail, success validates existence of more data in the reader.
+		if _, err = io.CopyN(ioutil.Discard, data, 1); err == nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", UnExpectedDataSize{Size: int(size)}
+		}
+	} else {
+		var n int64
+		if n, err = io.Copy(multiWriter, data); err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", toObjectErr(err, bucket, object)
+		}
+		size = n
+	}
+
+	newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
+	if md5Hex != "" {
+		if newMD5Hex != md5Hex {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", BadDigest{md5Hex, newMD5Hex}
+		}
+	}
+	err = fileWriter.Close()
+	if err != nil {
+		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+			return "", toObjectErr(clErr, bucket, object)
+		}
+		return "", err
+	}
+
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	xlMeta, err := readXLMetadata(xl.getRandomDisk(), minioMetaBucket, uploadIDPath)
+	if err != nil {
+		return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
+	}
+	xlMeta.AddObjectPart(partSuffix, newMD5Hex, size)
+
+	partPath := path.Join(mpartMetaPrefix, bucket, object, uploadID, partSuffix)
+	err = xl.renameObject(minioMetaBucket, tmpPartPath, minioMetaBucket, partPath)
+	if err != nil {
+		if dErr := xl.deleteObject(minioMetaBucket, tmpPartPath); dErr != nil {
+			return "", toObjectErr(dErr, minioMetaBucket, tmpPartPath)
+		}
+		return "", toObjectErr(err, minioMetaBucket, partPath)
+	}
+	if err = xl.writeXLMetadata(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID), xlMeta); err != nil {
+		return "", toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
+	}
+	return newMD5Hex, nil
+}
+
+// PutObjectPart - writes the multipart upload chunks.
+func (xl xlObjects) PutObjectPart(bucket, object, uploadID string, partID int, size int64, data io.Reader, md5Hex string) (string, error) {
+	return xl.putObjectPartCommon(bucket, object, uploadID, partID, size, data, md5Hex)
+}
+
+// ListObjectParts - list object parts, common function across both object layers.
+func (xl xlObjects) listObjectPartsCommon(bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return ListPartsInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify whether the bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return ListPartsInfo{}, BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return ListPartsInfo{}, ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	if !xl.isUploadIDExists(bucket, object, uploadID) {
+		return ListPartsInfo{}, InvalidUploadID{UploadID: uploadID}
+	}
+	// Hold lock so that there is no competing abort-multipart-upload or complete-multipart-upload.
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	result := ListPartsInfo{}
+
+	disk := xl.getRandomDisk() // Pick a random disk and read `xl.json` from there.
+	uploadIDPath := path.Join(mpartMetaPrefix, bucket, object, uploadID)
+	xlMeta, err := readXLMetadata(disk, minioMetaBucket, uploadIDPath)
+	if err != nil {
+		return ListPartsInfo{}, toObjectErr(err, minioMetaBucket, uploadIDPath)
+	}
+	// Only parts with higher part numbers will be listed.
+	parts := xlMeta.Parts[partNumberMarker:]
+	count := maxParts
+	for i, part := range parts {
+		var fi FileInfo
+		partNamePath := path.Join(mpartMetaPrefix, bucket, object, uploadID, part.Name)
+		fi, err = disk.StatFile(minioMetaBucket, partNamePath)
+		if err != nil {
+			return ListPartsInfo{}, toObjectErr(err, minioMetaBucket, partNamePath)
+		}
+		partNum := i + partNumberMarker + 1
+		result.Parts = append(result.Parts, partInfo{
+			PartNumber:   partNum,
+			ETag:         part.ETag,
+			LastModified: fi.ModTime,
+			Size:         fi.Size,
+		})
+		count--
+		if count == 0 {
+			break
+		}
+	}
+	// If listed entries are more than maxParts, we set IsTruncated as true.
+	if len(parts) > len(result.Parts) {
+		result.IsTruncated = true
+		// Make sure to fill next part number marker if IsTruncated is
+		// true for subsequent listing.
+		nextPartNumberMarker := result.Parts[len(result.Parts)-1].PartNumber
+		result.NextPartNumberMarker = nextPartNumberMarker
+	}
+	result.Bucket = bucket
+	result.Object = object
+	result.UploadID = uploadID
+	result.MaxParts = maxParts
+	return result, nil
+}
+
+// ListObjectParts - list object parts.
+func (xl xlObjects) ListObjectParts(bucket, object, uploadID string, partNumberMarker, maxParts int) (ListPartsInfo, error) {
+	return xl.listObjectPartsCommon(bucket, object, uploadID, partNumberMarker, maxParts)
+}
+
+func (xl xlObjects) CompleteMultipartUpload(bucket string, object string, uploadID string, parts []completePart) (string, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return "", BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify whether the bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return "", BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return "", ObjectNameInvalid{
+			Bucket: bucket,
+			Object: object,
+		}
+	}
+	if !xl.isUploadIDExists(bucket, object, uploadID) {
+		return "", InvalidUploadID{UploadID: uploadID}
+	}
+	// Hold lock so that
+	// 1) no one aborts this multipart upload
+	// 2) no one does a parallel complete-multipart-upload on this multipart upload
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+
+	// Calculate s3 compatible md5sum for complete multipart.
+	s3MD5, err := completeMultipartMD5(parts...)
+	if err != nil {
+		return "", err
+	}
+
+	uploadIDPath := pathJoin(mpartMetaPrefix, bucket, object, uploadID)
+	xlMeta, err := readXLMetadata(xl.getRandomDisk(), minioMetaBucket, uploadIDPath)
+	if err != nil {
+		return "", err
+	}
+
+	var objectSize int64
+	// Loop through all parts, validate them and then commit to disk.
+	for i, part := range parts {
+		// Construct part suffix.
+		partSuffix := fmt.Sprintf("object%d", part.PartNumber)
+		if xlMeta.SearchObjectPart(partSuffix, part.ETag) == -1 {
+			return "", InvalidPart{}
+		}
+		// All parts except the last part has to be atleast 5MB.
+		if (i < len(parts)-1) && !isMinAllowedPartSize(xlMeta.Parts[i].Size) {
+			return "", PartTooSmall{}
+		}
+		objectSize += xlMeta.Parts[i].Size
+	}
+
+	// Check if an object is present as one of the parent dir.
+	if xl.parentDirIsObject(bucket, path.Dir(object)) {
+		return "", toObjectErr(errFileAccessDenied, bucket, object)
+	}
+
+	// Save the final object size and modtime.
+	xlMeta.Stat.Size = objectSize
+	xlMeta.Stat.ModTime = time.Now().UTC()
+
+	// Save successfully calculated md5sum.
+	xlMeta.Meta["md5Sum"] = s3MD5
+	if err = xl.writeXLMetadata(minioMetaBucket, uploadIDPath, xlMeta); err != nil {
+		return "", toObjectErr(err, minioMetaBucket, uploadIDPath)
+	}
+
+	// Hold write lock on the destination before rename
+	nsMutex.Lock(bucket, object)
+	defer nsMutex.Unlock(bucket, object)
+
+	// Delete if an object already exists.
+	// FIXME: rename it to tmp file and delete only after
+	// the newly uploaded file is renamed from tmp location to
+	// the original location. Verify if the object is a multipart object.
+	err = xl.deleteObject(bucket, object)
+	if err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	if err = xl.renameObject(minioMetaBucket, uploadIDPath, bucket, object); err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Hold the lock so that two parallel complete-multipart-uploads do no
+	// leave a stale uploads.json behind.
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object))
+
+	// Validate if there are other incomplete upload-id's present for
+	// the object, if yes do not attempt to delete 'uploads.json'.
+	uploadIDs, err := getUploadIDs(bucket, object, xl.storageDisks...)
+	if err == nil {
+		uploadIDIdx := uploadIDs.SearchUploadID(uploadID)
+		if uploadIDIdx != -1 {
+			uploadIDs.Uploads = append(uploadIDs.Uploads[:uploadIDIdx], uploadIDs.Uploads[uploadIDIdx+1:]...)
+		}
+		if len(uploadIDs.Uploads) > 0 {
+			if err = updateUploadJSON(bucket, object, uploadIDs, xl.storageDisks...); err != nil {
+				return "", err
+			}
+			return s3MD5, nil
+		}
+	}
+
+	err = xl.deleteObject(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
+	if err != nil {
+		return "", toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
+	}
+
+	// Return md5sum.
+	return s3MD5, nil
+}
+
+// abortMultipartUploadCommon - aborts a multipart upload, common
+// function used by both object layers.
+func (xl xlObjects) abortMultipartUploadCommon(bucket, object, uploadID string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	if !xl.isBucketExist(bucket) {
+		return BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	if !xl.isUploadIDExists(bucket, object, uploadID) {
+		return InvalidUploadID{UploadID: uploadID}
+	}
+
+	// Hold lock so that there is no competing complete-multipart-upload or put-object-part.
+	nsMutex.Lock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+	defer nsMutex.Unlock(minioMetaBucket, pathJoin(mpartMetaPrefix, bucket, object, uploadID))
+
+	// Cleanup all uploaded parts.
+	if err := cleanupUploadedParts(bucket, object, uploadID, xl.storageDisks...); err != nil {
+		return err
+	}
+
+	// Validate if there are other incomplete upload-id's present for
+	// the object, if yes do not attempt to delete 'uploads.json'.
+	uploadIDs, err := getUploadIDs(bucket, object, xl.storageDisks...)
+	if err == nil {
+		uploadIDIdx := uploadIDs.SearchUploadID(uploadID)
+		if uploadIDIdx != -1 {
+			uploadIDs.Uploads = append(uploadIDs.Uploads[:uploadIDIdx], uploadIDs.Uploads[uploadIDIdx+1:]...)
+		}
+		if len(uploadIDs.Uploads) > 0 {
+			return nil
+		}
+	}
+	if err = xl.deleteObject(minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object)); err != nil {
+		return toObjectErr(err, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object))
+	}
+	return nil
+}
+
+// AbortMultipartUpload - aborts a multipart upload.
+func (xl xlObjects) AbortMultipartUpload(bucket, object, uploadID string) error {
+	return xl.abortMultipartUploadCommon(bucket, object, uploadID)
+}

xl-v1-object.go

@@ -0,0 +1,357 @@
+package main
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"io"
+	"path"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/minio/minio/pkg/mimedb"
+)
+
+/// Object Operations
+
+// GetObject - get an object.
+func (xl xlObjects) GetObject(bucket, object string, startOffset int64) (io.ReadCloser, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return nil, BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify if object is valid.
+	if !IsValidObjectName(object) {
+		return nil, ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	nsMutex.RLock(bucket, object)
+	defer nsMutex.RUnlock(bucket, object)
+	fileReader, fileWriter := io.Pipe()
+	xlMeta, err := readXLMetadata(xl.getRandomDisk(), bucket, object)
+	if err != nil {
+		return nil, toObjectErr(err, bucket, object)
+	}
+	partIndex, offset, err := xlMeta.getPartNumberOffset(startOffset)
+	if err != nil {
+		return nil, toObjectErr(err, bucket, object)
+	}
+
+	// Hold a read lock once more which can be released after the following go-routine ends.
+	// We hold RLock once more because the current function would return before the go routine below
+	// executes and hence releasing the read lock (because of defer'ed nsMutex.RUnlock() call).
+	nsMutex.RLock(bucket, object)
+	go func() {
+		defer nsMutex.RUnlock(bucket, object)
+		for ; partIndex < len(xlMeta.Parts); partIndex++ {
+			part := xlMeta.Parts[partIndex]
+			r, err := xl.erasureDisk.ReadFile(bucket, pathJoin(object, part.Name), offset)
+			if err != nil {
+				fileWriter.CloseWithError(err)
+				return
+			}
+			// Reset offset to 0 as it would be non-0 only for the first loop if startOffset is non-0.
+			offset = 0
+			if _, err = io.Copy(fileWriter, r); err != nil {
+				switch reader := r.(type) {
+				case *io.PipeReader:
+					reader.CloseWithError(err)
+				case io.ReadCloser:
+					reader.Close()
+				}
+				fileWriter.CloseWithError(err)
+				return
+			}
+			// Close the readerCloser that reads multiparts of an object from the xl storage layer.
+			// Not closing leaks underlying file descriptors.
+			r.Close()
+		}
+		fileWriter.Close()
+	}()
+	return fileReader, nil
+}
+
+// GetObjectInfo - get object info.
+func (xl xlObjects) GetObjectInfo(bucket, object string) (ObjectInfo, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return ObjectInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify if object is valid.
+	if !IsValidObjectName(object) {
+		return ObjectInfo{}, ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	nsMutex.RLock(bucket, object)
+	defer nsMutex.RUnlock(bucket, object)
+	info, err := xl.getObjectInfo(bucket, object)
+	if err != nil {
+		return ObjectInfo{}, toObjectErr(err, bucket, object)
+	}
+	return info, nil
+}
+
+func (xl xlObjects) getObjectInfo(bucket, object string) (objInfo ObjectInfo, err error) {
+	// Count for errors encountered.
+	var xlJSONErrCount = 0
+
+	// Loop through and return the first success entry based on the
+	// selected random disk.
+	for xlJSONErrCount < len(xl.storageDisks) {
+		// Choose a random disk on each attempt, do not hit the same disk all the time.
+		disk := xl.getRandomDisk() // Pick a random disk.
+		var xlMeta xlMetaV1
+		xlMeta, err = readXLMetadata(disk, bucket, object)
+		if err == nil {
+			objInfo = ObjectInfo{}
+			objInfo.IsDir = false
+			objInfo.Bucket = bucket
+			objInfo.Name = object
+			objInfo.Size = xlMeta.Stat.Size
+			objInfo.ModTime = xlMeta.Stat.ModTime
+			objInfo.MD5Sum = xlMeta.Meta["md5Sum"]
+			objInfo.ContentType = xlMeta.Meta["content-type"]
+			objInfo.ContentEncoding = xlMeta.Meta["content-encoding"]
+			return objInfo, nil
+		}
+		xlJSONErrCount++ // Update error count.
+	}
+
+	// Return error at the end.
+	return ObjectInfo{}, err
+}
+
+// renameObject - renaming all source objects to destination object across all disks.
+func (xl xlObjects) renameObject(srcBucket, srcObject, dstBucket, dstObject string) error {
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+
+	// Initialize list of errors.
+	var errs = make([]error, len(xl.storageDisks))
+
+	// Rename file on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		// Append "/" as srcObject and dstObject are either leaf-dirs or non-leaf-dris.
+		// If srcObject is an object instead of prefix we just rename the leaf-dir and
+		// not rename the part and metadata files separately.
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			err := disk.RenameFile(srcBucket, retainSlash(srcObject), dstBucket, retainSlash(dstObject))
+			if err != nil {
+				errs[index] = err
+			}
+			errs[index] = nil
+		}(index, disk)
+	}
+
+	// Wait for all RenameFile to finish.
+	wg.Wait()
+
+	// Gather err count.
+	var errCount = 0
+	for _, err := range errs {
+		if err == nil {
+			continue
+		}
+		errCount++
+	}
+	// We can safely allow RenameFile errors up to len(xl.storageDisks) - xl.writeQuorum
+	// otherwise return failure. Cleanup successful renames.
+	if errCount > len(xl.storageDisks)-xl.writeQuorum {
+		// Special condition if readQuorum exists, then return success.
+		if errCount <= len(xl.storageDisks)-xl.readQuorum {
+			return nil
+		}
+		xl.deleteObject(srcBucket, srcObject)
+		return errWriteQuorum
+	}
+	return nil
+}
+
+// PutObject - create an object.
+func (xl xlObjects) PutObject(bucket string, object string, size int64, data io.Reader, metadata map[string]string) (string, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return "", BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return "", BucketNotFound{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return "", ObjectNameInvalid{
+			Bucket: bucket,
+			Object: object,
+		}
+	}
+	// No metadata is set, allocate a new one.
+	if metadata == nil {
+		metadata = make(map[string]string)
+	}
+	nsMutex.Lock(bucket, object)
+	defer nsMutex.Unlock(bucket, object)
+
+	tempErasureObj := path.Join(tmpMetaPrefix, bucket, object, "object1")
+	tempObj := path.Join(tmpMetaPrefix, bucket, object)
+	fileWriter, err := xl.erasureDisk.CreateFile(minioMetaBucket, tempErasureObj)
+	if err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Initialize md5 writer.
+	md5Writer := md5.New()
+
+	// Instantiate a new multi writer.
+	multiWriter := io.MultiWriter(md5Writer, fileWriter)
+
+	// Instantiate checksum hashers and create a multiwriter.
+	if size > 0 {
+		if _, err = io.CopyN(multiWriter, data, size); err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", toObjectErr(err, bucket, object)
+		}
+	} else {
+		if _, err = io.Copy(multiWriter, data); err != nil {
+			if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+				return "", toObjectErr(clErr, bucket, object)
+			}
+			return "", toObjectErr(err, bucket, object)
+		}
+	}
+
+	// Save additional erasureMetadata.
+	modTime := time.Now().UTC()
+
+	newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
+	// Update the md5sum if not set with the newly calculated one.
+	if len(metadata["md5Sum"]) == 0 {
+		metadata["md5Sum"] = newMD5Hex
+	}
+	// If not set default to "application/octet-stream"
+	if metadata["content-type"] == "" {
+		contentType := "application/octet-stream"
+		if objectExt := filepath.Ext(object); objectExt != "" {
+			content, ok := mimedb.DB[strings.ToLower(strings.TrimPrefix(objectExt, "."))]
+			if ok {
+				contentType = content.ContentType
+			}
+		}
+		metadata["content-type"] = contentType
+	}
+
+	// md5Hex representation.
+	md5Hex := metadata["md5Sum"]
+	if md5Hex != "" {
+		if newMD5Hex != md5Hex {
+			if err = safeCloseAndRemove(fileWriter); err != nil {
+				return "", toObjectErr(err, bucket, object)
+			}
+			return "", BadDigest{md5Hex, newMD5Hex}
+		}
+	}
+
+	err = fileWriter.Close()
+	if err != nil {
+		if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
+			return "", toObjectErr(clErr, bucket, object)
+		}
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Check if an object is present as one of the parent dir.
+	if xl.parentDirIsObject(bucket, path.Dir(object)) {
+		return "", toObjectErr(errFileAccessDenied, bucket, object)
+	}
+
+	// Delete if an object already exists.
+	err = xl.deleteObject(bucket, object)
+	if err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	err = xl.renameObject(minioMetaBucket, tempObj, bucket, object)
+	if err != nil {
+		if dErr := xl.deleteObject(minioMetaBucket, tempObj); dErr != nil {
+			return "", toObjectErr(dErr, minioMetaBucket, tempObj)
+		}
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	xlMeta := xlMetaV1{}
+	xlMeta.Version = "1"
+	xlMeta.Format = "xl"
+	xlMeta.Meta = metadata
+	xlMeta.Stat.Size = size
+	xlMeta.Stat.ModTime = modTime
+	xlMeta.AddObjectPart("object1", newMD5Hex, xlMeta.Stat.Size)
+	if err = xl.writeXLMetadata(bucket, object, xlMeta); err != nil {
+		return "", toObjectErr(err, bucket, object)
+	}
+
+	// Return md5sum, successfully wrote object.
+	return newMD5Hex, nil
+}
+
+// deleteObject - deletes a regular object.
+func (xl xlObjects) deleteObject(bucket, object string) error {
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+
+	// Initialize list of errors.
+	var dErrs = make([]error, len(xl.storageDisks))
+
+	for index, disk := range xl.storageDisks {
+		wg.Add(1)
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			dErrs[index] = cleanupDir(disk, bucket, object)
+		}(index, disk)
+	}
+
+	// Wait for all routines to finish.
+	wg.Wait()
+
+	var fileNotFoundCnt, deleteFileErr int
+	// Loop through all the concocted errors.
+	for _, err := range dErrs {
+		if err == nil {
+			continue
+		}
+		// If file not found, count them.
+		if err == errFileNotFound {
+			fileNotFoundCnt++
+			continue
+		}
+
+		// Update error counter separately.
+		deleteFileErr++
+	}
+
+	// Return err if all disks report file not found.
+	if fileNotFoundCnt == len(xl.storageDisks) {
+		return errFileNotFound
+	} else if deleteFileErr > len(xl.storageDisks)-xl.writeQuorum {
+		// Return errWriteQuorum if errors were more than
+		// allowed write quorum.
+		return errWriteQuorum
+	}
+
+	return nil
+}
+
+// DeleteObject - delete the object.
+func (xl xlObjects) DeleteObject(bucket, object string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	if !IsValidObjectName(object) {
+		return ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
+	nsMutex.Lock(bucket, object)
+	defer nsMutex.Unlock(bucket, object)
+	xl.deleteObject(bucket, object)
+	return nil
+}

xl-v1.go

@@ -0,0 +1,177 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 main
+
+import (
+	"errors"
+	"fmt"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+const (
+	formatConfigFile = "format.json"
+	xlMetaJSONFile   = "xl.json"
+	uploadsJSONFile  = "uploads.json"
+)
+
+// xlObjects - Implements fs object layer.
+type xlObjects struct {
+	storageDisks       []StorageAPI
+	erasureDisk        *erasure
+	dataBlocks         int
+	parityBlocks       int
+	readQuorum         int
+	writeQuorum        int
+	listObjectMap      map[listParams][]*treeWalker
+	listObjectMapMutex *sync.Mutex
+}
+
+// errMaxDisks - returned for reached maximum of disks.
+var errMaxDisks = errors.New("Number of disks are higher than supported maximum count '16'")
+
+// errMinDisks - returned for minimum number of disks.
+var errMinDisks = errors.New("Number of disks are smaller than supported minimum count '8'")
+
+// errNumDisks - returned for odd number of disks.
+var errNumDisks = errors.New("Number of disks should be multiples of '2'")
+
+const (
+	// Maximum erasure blocks.
+	maxErasureBlocks = 16
+	// Minimum erasure blocks.
+	minErasureBlocks = 8
+)
+
+func checkSufficientDisks(disks []string) error {
+	// Verify total number of disks.
+	totalDisks := len(disks)
+	if totalDisks > maxErasureBlocks {
+		return errMaxDisks
+	}
+	if totalDisks < minErasureBlocks {
+		return errMinDisks
+	}
+
+	// isEven function to verify if a given number if even.
+	isEven := func(number int) bool {
+		return number%2 == 0
+	}
+
+	// Verify if we have even number of disks.
+	// only combination of 8, 10, 12, 14, 16 are supported.
+	if !isEven(totalDisks) {
+		return errNumDisks
+	}
+
+	return nil
+}
+
+// Depending on the disk type network or local, initialize storage layer.
+func newStorageLayer(disk string) (storage StorageAPI, err error) {
+	if !strings.ContainsRune(disk, ':') || filepath.VolumeName(disk) != "" {
+		// Initialize filesystem storage API.
+		return newPosix(disk)
+	}
+	// Initialize rpc client storage API.
+	return newRPCClient(disk)
+}
+
+// Initialize all storage disks to bootstrap.
+func bootstrapDisks(disks []string) ([]StorageAPI, error) {
+	storageDisks := make([]StorageAPI, len(disks))
+	for index, disk := range disks {
+		var err error
+		// Intentionally ignore disk not found errors while
+		// initializing POSIX, so that we have successfully
+		// initialized posix Storage. Subsequent calls to XL/Erasure
+		// will manage any errors related to disks.
+		storageDisks[index], err = newStorageLayer(disk)
+		if err != nil && err != errDiskNotFound {
+			return nil, err
+		}
+	}
+	return storageDisks, nil
+}
+
+// newXLObjects - initialize new xl object layer.
+func newXLObjects(disks []string) (ObjectLayer, error) {
+	if err := checkSufficientDisks(disks); err != nil {
+		return nil, err
+	}
+
+	// Bootstrap disks.
+	storageDisks, err := bootstrapDisks(disks)
+	if err != nil {
+		return nil, err
+	}
+
+	// Initialize object layer - like creating minioMetaBucket, cleaning up tmp files etc.
+	initObjectLayer(storageDisks...)
+
+	// Load saved XL format.json and validate.
+	newPosixDisks, err := loadFormatXL(storageDisks)
+	if err != nil {
+		switch err {
+		case errUnformattedDisk:
+			// Save new XL format.
+			errSave := initFormatXL(storageDisks)
+			if errSave != nil {
+				return nil, errSave
+			}
+			newPosixDisks = storageDisks
+		default:
+			// errCorruptedDisk - error.
+			return nil, fmt.Errorf("Unable to recognize backend format, %s", err)
+		}
+	}
+
+	// FIXME: healFormatXL(newDisks)
+
+	newErasureDisk, err := newErasure(newPosixDisks)
+	if err != nil {
+		return nil, err
+	}
+
+	// Calculate data and parity blocks.
+	dataBlocks, parityBlocks := len(newPosixDisks)/2, len(newPosixDisks)/2
+
+	xl := xlObjects{
+		storageDisks:       newPosixDisks,
+		erasureDisk:        newErasureDisk,
+		dataBlocks:         dataBlocks,
+		parityBlocks:       parityBlocks,
+		listObjectMap:      make(map[listParams][]*treeWalker),
+		listObjectMapMutex: &sync.Mutex{},
+	}
+
+	// Figure out read and write quorum based on number of storage disks.
+	// Read quorum should be always N/2 + 1 (due to Vandermonde matrix
+	// erasure requirements)
+	xl.readQuorum = len(xl.storageDisks)/2 + 1
+
+	// Write quorum is assumed if we have total disks + 3
+	// parity. (Need to discuss this again)
+	xl.writeQuorum = len(xl.storageDisks)/2 + 3
+	if xl.writeQuorum > len(xl.storageDisks) {
+		xl.writeQuorum = len(xl.storageDisks)
+	}
+
+	// Return successfully initialized object layer.
+	return xl, nil
+}