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minio/cmd/xl-v1-metadata.go

546 lines
16 KiB

/*
* Minio Cloud Storage, (C) 2016, 2017, 2017 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 cmd
import (
"context"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"path"
"sort"
"sync"
"time"
"github.com/minio/minio/cmd/logger"
)
const erasureAlgorithmKlauspost = "klauspost/reedsolomon/vandermonde"
// ObjectPartInfo Info of each part kept in the multipart metadata
// file after CompleteMultipartUpload() is called.
type ObjectPartInfo struct {
Number int `json:"number"`
Name string `json:"name"`
ETag string `json:"etag"`
Size int64 `json:"size"`
ActualSize int64 `json:"actualSize"`
}
// byObjectPartNumber is a collection satisfying sort.Interface.
type byObjectPartNumber []ObjectPartInfo
func (t byObjectPartNumber) Len() int { return len(t) }
func (t byObjectPartNumber) Swap(i, j int) { t[i], t[j] = t[j], t[i] }
func (t byObjectPartNumber) Less(i, j int) bool { return t[i].Number < t[j].Number }
// ChecksumInfo - carries checksums of individual scattered parts per disk.
type ChecksumInfo struct {
Name string
Algorithm BitrotAlgorithm
Hash []byte
}
type checksumInfoJSON struct {
Name string `json:"name"`
Algorithm string `json:"algorithm"`
Hash string `json:"hash,omitempty"`
}
// MarshalJSON marshals the ChecksumInfo struct
func (c ChecksumInfo) MarshalJSON() ([]byte, error) {
info := checksumInfoJSON{
Name: c.Name,
Algorithm: c.Algorithm.String(),
Hash: hex.EncodeToString(c.Hash),
}
return json.Marshal(info)
}
// UnmarshalJSON - should never be called, instead xlMetaV1UnmarshalJSON() should be used.
func (c *ChecksumInfo) UnmarshalJSON(data []byte) error {
logger.LogIf(context.Background(), errUnexpected)
var info checksumInfoJSON
if err := json.Unmarshal(data, &info); err != nil {
return err
}
sum, err := hex.DecodeString(info.Hash)
if err != nil {
return err
}
c.Name = info.Name
c.Algorithm = BitrotAlgorithmFromString(info.Algorithm)
c.Hash = sum
if !c.Algorithm.Available() {
logger.LogIf(context.Background(), errBitrotHashAlgoInvalid)
return errBitrotHashAlgoInvalid
}
return nil
}
// ErasureInfo holds erasure coding and bitrot related information.
type ErasureInfo struct {
// Algorithm is the string representation of erasure-coding-algorithm
Algorithm string `json:"algorithm"`
// DataBlocks is the number of data blocks for erasure-coding
DataBlocks int `json:"data"`
// ParityBlocks is the number of parity blocks for erasure-coding
ParityBlocks int `json:"parity"`
// BlockSize is the size of one erasure-coded block
BlockSize int64 `json:"blockSize"`
// Index is the index of the current disk
Index int `json:"index"`
// Distribution is the distribution of the data and parity blocks
Distribution []int `json:"distribution"`
// Checksums holds all bitrot checksums of all erasure encoded blocks
Checksums []ChecksumInfo `json:"checksum,omitempty"`
}
// AddChecksumInfo adds a checksum of a part.
func (e *ErasureInfo) AddChecksumInfo(ckSumInfo ChecksumInfo) {
for i, sum := range e.Checksums {
if sum.Name == ckSumInfo.Name {
e.Checksums[i] = ckSumInfo
return
}
}
e.Checksums = append(e.Checksums, ckSumInfo)
}
// GetChecksumInfo - get checksum of a part.
func (e ErasureInfo) GetChecksumInfo(partName string) (ckSum ChecksumInfo) {
// Return the checksum.
for _, sum := range e.Checksums {
if sum.Name == partName {
return sum
}
}
return ChecksumInfo{}
}
// statInfo - carries stat information of the object.
type statInfo struct {
Size int64 `json:"size"` // Size of the object `xl.json`.
ModTime time.Time `json:"modTime"` // ModTime of the object `xl.json`.
}
// A xlMetaV1 represents `xl.json` metadata header.
type xlMetaV1 struct {
Version string `json:"version"` // Version of the current `xl.json`.
Format string `json:"format"` // Format of the current `xl.json`.
Stat statInfo `json:"stat"` // Stat of the current object `xl.json`.
// Erasure coded info for the current object `xl.json`.
Erasure ErasureInfo `json:"erasure"`
// Minio release tag for current object `xl.json`.
Minio struct {
Release string `json:"release"`
} `json:"minio"`
// Metadata map for current object `xl.json`.
Meta map[string]string `json:"meta,omitempty"`
// Captures all the individual object `xl.json`.
Parts []ObjectPartInfo `json:"parts,omitempty"`
}
// XL metadata constants.
const (
// XL meta version.
xlMetaVersion = "1.0.1"
// XL meta version.
xlMetaVersion100 = "1.0.0"
// XL meta format string.
xlMetaFormat = "xl"
// Add new constants here.
)
// newXLMetaV1 - initializes new xlMetaV1, adds version, allocates a fresh erasure info.
func newXLMetaV1(object string, dataBlocks, parityBlocks int) (xlMeta xlMetaV1) {
xlMeta = xlMetaV1{}
xlMeta.Version = xlMetaVersion
xlMeta.Format = xlMetaFormat
xlMeta.Minio.Release = ReleaseTag
xlMeta.Erasure = ErasureInfo{
Algorithm: erasureAlgorithmKlauspost,
DataBlocks: dataBlocks,
ParityBlocks: parityBlocks,
BlockSize: blockSizeV1,
Distribution: hashOrder(object, dataBlocks+parityBlocks),
}
return xlMeta
}
// Return a new xlMetaV1 initialized using the given xlMetaV1. Used in healing to make sure that we do not copy
// over any part's checksum info which will differ for different disks.
func newXLMetaFromXLMeta(meta xlMetaV1) xlMetaV1 {
xlMeta := meta
xlMeta.Erasure.Checksums = nil
xlMeta.Parts = nil
return xlMeta
}
// IsValid - tells if the format is sane by validating the version
// string, format and erasure info fields.
func (m xlMetaV1) IsValid() bool {
return isXLMetaFormatValid(m.Version, m.Format) &&
isXLMetaErasureInfoValid(m.Erasure.DataBlocks, m.Erasure.ParityBlocks)
}
// Verifies if the backend format metadata is sane by validating
// the version string and format style.
func isXLMetaFormatValid(version, format string) bool {
return ((version == xlMetaVersion || version == xlMetaVersion100) &&
format == xlMetaFormat)
}
// Verifies if the backend format metadata is sane by validating
// the ErasureInfo, i.e. data and parity blocks.
func isXLMetaErasureInfoValid(data, parity int) bool {
return ((data >= parity) && (data != 0) && (parity != 0))
}
// Converts metadata to object info.
func (m xlMetaV1) ToObjectInfo(bucket, object string) ObjectInfo {
objInfo := ObjectInfo{
IsDir: false,
Bucket: bucket,
Name: object,
Size: m.Stat.Size,
ModTime: m.Stat.ModTime,
ContentType: m.Meta["content-type"],
ContentEncoding: m.Meta["content-encoding"],
}
objInfo.backendType = BackendErasure
// Extract etag from metadata.
objInfo.ETag = extractETag(m.Meta)
// etag/md5Sum has already been extracted. We need to
// remove to avoid it from appearing as part of
// response headers. e.g, X-Minio-* or X-Amz-*.
objInfo.UserDefined = cleanMetadata(m.Meta)
// All the parts per object.
objInfo.Parts = m.Parts
// Update storage class
if sc, ok := m.Meta[amzStorageClass]; ok {
objInfo.StorageClass = sc
} else {
objInfo.StorageClass = globalMinioDefaultStorageClass
}
// Success.
return objInfo
}
// objectPartIndex - returns the index of matching object part number.
func objectPartIndex(parts []ObjectPartInfo, partNumber int) int {
for i, part := range parts {
if partNumber == part.Number {
return i
}
}
return -1
}
// AddObjectPart - add a new object part in order.
func (m *xlMetaV1) AddObjectPart(partNumber int, partName string, partETag string, partSize int64, actualSize int64) {
partInfo := ObjectPartInfo{
Number: partNumber,
Name: partName,
ETag: partETag,
Size: partSize,
ActualSize: actualSize,
}
// Update part info if it already exists.
for i, part := range m.Parts {
if partNumber == part.Number {
m.Parts[i] = partInfo
return
}
}
// Proceed to include new part info.
m.Parts = append(m.Parts, partInfo)
// Parts in xlMeta should be in sorted order by part number.
sort.Sort(byObjectPartNumber(m.Parts))
}
// ObjectToPartOffset - translate offset of an object to offset of its individual part.
func (m xlMetaV1) ObjectToPartOffset(ctx context.Context, offset int64) (partIndex int, partOffset int64, err error) {
if offset == 0 {
// Special case - if offset is 0, then partIndex and partOffset are always 0.
return 0, 0, nil
}
partOffset = offset
// Seek until object offset maps to a particular part offset.
for i, part := range m.Parts {
partIndex = i
// Offset is smaller than size we have reached the proper part offset.
if partOffset < part.Size {
return partIndex, partOffset, nil
}
// Continue to towards the next part.
partOffset -= part.Size
}
logger.LogIf(ctx, InvalidRange{})
// Offset beyond the size of the object return InvalidRange.
return 0, 0, InvalidRange{}
}
func getXLMetaInQuorum(ctx context.Context, metaArr []xlMetaV1, modTime time.Time, quorum int) (xmv xlMetaV1, e error) {
metaHashes := make([]string, len(metaArr))
for i, meta := range metaArr {
if meta.IsValid() && meta.Stat.ModTime.Equal(modTime) {
h := sha256.New()
for _, p := range meta.Parts {
h.Write([]byte(p.Name))
}
metaHashes[i] = hex.EncodeToString(h.Sum(nil))
}
}
metaHashCountMap := make(map[string]int)
for _, hash := range metaHashes {
if hash == "" {
continue
}
metaHashCountMap[hash]++
}
maxHash := ""
maxCount := 0
for hash, count := range metaHashCountMap {
if count > maxCount {
maxCount = count
maxHash = hash
}
}
if maxCount < quorum {
return xlMetaV1{}, errXLReadQuorum
}
for i, hash := range metaHashes {
if hash == maxHash {
return metaArr[i], nil
}
}
return xlMetaV1{}, errXLReadQuorum
}
// pickValidXLMeta - picks one valid xlMeta content and returns from a
// slice of xlmeta content.
func pickValidXLMeta(ctx context.Context, metaArr []xlMetaV1, modTime time.Time, quorum int) (xmv xlMetaV1, e error) {
return getXLMetaInQuorum(ctx, metaArr, modTime, quorum)
}
// list of all errors that can be ignored in a metadata operation.
var objMetadataOpIgnoredErrs = append(baseIgnoredErrs, errDiskAccessDenied, errVolumeNotFound, errFileNotFound, errFileAccessDenied, errCorruptedFormat)
// readXLMetaParts - returns the XL Metadata Parts from xl.json of one of the disks picked at random.
func (xl xlObjects) readXLMetaParts(ctx context.Context, bucket, object string) (xlMetaParts []ObjectPartInfo, xlMeta map[string]string, err error) {
var ignoredErrs []error
for _, disk := range xl.getLoadBalancedDisks() {
if disk == nil {
ignoredErrs = append(ignoredErrs, errDiskNotFound)
continue
}
xlMetaParts, xlMeta, err = readXLMetaParts(ctx, disk, bucket, object)
if err == nil {
return xlMetaParts, xlMeta, nil
}
// For any reason disk or bucket is not available continue
// and read from other disks.
if IsErrIgnored(err, objMetadataOpIgnoredErrs...) {
ignoredErrs = append(ignoredErrs, err)
continue
}
// Error is not ignored, return right here.
return nil, nil, err
}
// If all errors were ignored, reduce to maximal occurrence
// based on the read quorum.
readQuorum := len(xl.getDisks()) / 2
return nil, nil, reduceReadQuorumErrs(ctx, ignoredErrs, nil, readQuorum)
}
// readXLMetaStat - return xlMetaV1.Stat and xlMetaV1.Meta from one of the disks picked at random.
func (xl xlObjects) readXLMetaStat(ctx context.Context, bucket, object string) (xlStat statInfo, xlMeta map[string]string, err error) {
var ignoredErrs []error
for _, disk := range xl.getLoadBalancedDisks() {
if disk == nil {
ignoredErrs = append(ignoredErrs, errDiskNotFound)
continue
}
// parses only xlMetaV1.Meta and xlMeta.Stat
xlStat, xlMeta, err = readXLMetaStat(ctx, disk, bucket, object)
if err == nil {
return xlStat, xlMeta, nil
}
// For any reason disk or bucket is not available continue
// and read from other disks.
if IsErrIgnored(err, objMetadataOpIgnoredErrs...) {
ignoredErrs = append(ignoredErrs, err)
continue
}
// Error is not ignored, return right here.
return statInfo{}, nil, err
}
// If all errors were ignored, reduce to maximal occurrence
// based on the read quorum.
readQuorum := len(xl.getDisks()) / 2
return statInfo{}, nil, reduceReadQuorumErrs(ctx, ignoredErrs, nil, readQuorum)
}
// deleteXLMetadata - deletes `xl.json` on a single disk.
func deleteXLMetdata(ctx context.Context, disk StorageAPI, bucket, prefix string) error {
jsonFile := path.Join(prefix, xlMetaJSONFile)
err := disk.DeleteFile(bucket, jsonFile)
logger.LogIf(ctx, err)
return err
}
// writeXLMetadata - writes `xl.json` to a single disk.
func writeXLMetadata(ctx context.Context, disk StorageAPI, bucket, prefix string, xlMeta xlMetaV1) error {
jsonFile := path.Join(prefix, xlMetaJSONFile)
// Marshal json.
metadataBytes, err := json.Marshal(&xlMeta)
if err != nil {
logger.LogIf(ctx, err)
return err
}
// Persist marshaled data.
err = disk.WriteAll(bucket, jsonFile, metadataBytes)
logger.LogIf(ctx, err)
return err
}
// deleteAllXLMetadata - deletes all partially written `xl.json` depending on errs.
func deleteAllXLMetadata(ctx context.Context, disks []StorageAPI, bucket, prefix string, errs []error) {
var wg = &sync.WaitGroup{}
// Delete all the `xl.json` left over.
for index, disk := range disks {
if disk == nil {
continue
}
// Undo rename object in parallel.
wg.Add(1)
go func(index int, disk StorageAPI) {
defer wg.Done()
if errs[index] != nil {
return
}
_ = deleteXLMetdata(ctx, disk, bucket, prefix)
}(index, disk)
}
wg.Wait()
}
// Rename `xl.json` content to destination location for each disk in order.
func renameXLMetadata(ctx context.Context, disks []StorageAPI, srcBucket, srcEntry, dstBucket, dstEntry string, quorum int) ([]StorageAPI, error) {
isDir := false
srcXLJSON := path.Join(srcEntry, xlMetaJSONFile)
dstXLJSON := path.Join(dstEntry, xlMetaJSONFile)
return rename(ctx, disks, srcBucket, srcXLJSON, dstBucket, dstXLJSON, isDir, quorum, []error{errFileNotFound})
}
// writeUniqueXLMetadata - writes unique `xl.json` content for each disk in order.
func writeUniqueXLMetadata(ctx context.Context, disks []StorageAPI, bucket, prefix string, xlMetas []xlMetaV1, quorum int) ([]StorageAPI, error) {
var wg = &sync.WaitGroup{}
var mErrs = make([]error, len(disks))
// Start writing `xl.json` to all disks in parallel.
for index, disk := range disks {
if disk == nil {
mErrs[index] = errDiskNotFound
continue
}
wg.Add(1)
// Write `xl.json` in a routine.
go func(index int, disk StorageAPI) {
defer wg.Done()
// Pick one xlMeta for a disk at index.
xlMetas[index].Erasure.Index = index + 1
// Write unique `xl.json` for a disk at index.
err := writeXLMetadata(ctx, disk, bucket, prefix, xlMetas[index])
if err != nil {
mErrs[index] = err
}
}(index, disk)
}
// Wait for all the routines.
wg.Wait()
err := reduceWriteQuorumErrs(ctx, mErrs, objectOpIgnoredErrs, quorum)
if err == errXLWriteQuorum {
// Delete all `xl.json` successfully renamed.
deleteAllXLMetadata(ctx, disks, bucket, prefix, mErrs)
}
return evalDisks(disks, mErrs), err
}
// writeSameXLMetadata - write `xl.json` on all disks in order.
func writeSameXLMetadata(ctx context.Context, disks []StorageAPI, bucket, prefix string, xlMeta xlMetaV1, writeQuorum int) ([]StorageAPI, error) {
var wg = &sync.WaitGroup{}
var mErrs = make([]error, len(disks))
// Start writing `xl.json` to all disks in parallel.
for index, disk := range disks {
if disk == nil {
mErrs[index] = errDiskNotFound
continue
}
wg.Add(1)
// Write `xl.json` in a routine.
go func(index int, disk StorageAPI, metadata xlMetaV1) {
defer wg.Done()
// Save the disk order index.
metadata.Erasure.Index = index + 1
// Write xl metadata.
err := writeXLMetadata(ctx, disk, bucket, prefix, metadata)
if err != nil {
mErrs[index] = err
}
}(index, disk, xlMeta)
}
// Wait for all the routines.
wg.Wait()
err := reduceWriteQuorumErrs(ctx, mErrs, objectOpIgnoredErrs, writeQuorum)
if err == errXLWriteQuorum {
// Delete all `xl.json` successfully renamed.
deleteAllXLMetadata(ctx, disks, bucket, prefix, mErrs)
}
return evalDisks(disks, mErrs), err
}