minio/cmd/erasure-metadata.go

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/*
* MinIO Cloud Storage, (C) 2016-2019 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"
"encoding/hex"
"fmt"
"net/http"
"sort"
"time"
xhttp "github.com/minio/minio/cmd/http"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/bucket/replication"
"github.com/minio/minio/pkg/sync/errgroup"
"github.com/minio/sha256-simd"
)
const erasureAlgorithm = "rs-vandermonde"
// 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 }
// AddChecksumInfo adds a checksum of a part.
func (e *ErasureInfo) AddChecksumInfo(ckSumInfo ChecksumInfo) {
for i, sum := range e.Checksums {
if sum.PartNumber == ckSumInfo.PartNumber {
e.Checksums[i] = ckSumInfo
return
}
}
e.Checksums = append(e.Checksums, ckSumInfo)
}
// GetChecksumInfo - get checksum of a part.
func (e ErasureInfo) GetChecksumInfo(partNumber int) (ckSum ChecksumInfo) {
for _, sum := range e.Checksums {
if sum.PartNumber == partNumber {
// Return the checksum
return sum
}
}
return ChecksumInfo{}
}
// ShardFileSize - returns final erasure size from original size.
func (e ErasureInfo) ShardFileSize(totalLength int64) int64 {
if totalLength == 0 {
return 0
}
if totalLength == -1 {
return -1
}
numShards := totalLength / e.BlockSize
lastBlockSize := totalLength % e.BlockSize
lastShardSize := ceilFrac(lastBlockSize, int64(e.DataBlocks))
return numShards*e.ShardSize() + lastShardSize
}
// ShardSize - returns actual shared size from erasure blockSize.
func (e ErasureInfo) ShardSize() int64 {
return ceilFrac(e.BlockSize, int64(e.DataBlocks))
}
// IsValid - tells if erasure info fields are valid.
func (fi FileInfo) IsValid() bool {
if fi.Deleted {
// Delete marker has no data, no need to check
// for erasure coding information
return true
}
dataBlocks := fi.Erasure.DataBlocks
parityBlocks := fi.Erasure.ParityBlocks
return ((dataBlocks >= parityBlocks) &&
(dataBlocks != 0) && (parityBlocks != 0))
}
// ToObjectInfo - Converts metadata to object info.
func (fi FileInfo) ToObjectInfo(bucket, object string) ObjectInfo {
object = decodeDirObject(object)
versionID := fi.VersionID
if globalBucketVersioningSys.Enabled(bucket) && versionID == "" {
versionID = nullVersionID
}
objInfo := ObjectInfo{
IsDir: HasSuffix(object, SlashSeparator),
Bucket: bucket,
Name: object,
VersionID: versionID,
IsLatest: fi.IsLatest,
DeleteMarker: fi.Deleted,
Size: fi.Size,
ModTime: fi.ModTime,
Legacy: fi.XLV1,
ContentType: fi.Metadata["content-type"],
ContentEncoding: fi.Metadata["content-encoding"],
}
// Update expires
var (
t time.Time
e error
)
if exp, ok := fi.Metadata["expires"]; ok {
if t, e = time.Parse(http.TimeFormat, exp); e == nil {
objInfo.Expires = t.UTC()
}
}
objInfo.backendType = BackendErasure
// Extract etag from metadata.
objInfo.ETag = extractETag(fi.Metadata)
// Add user tags to the object info
objInfo.UserTags = fi.Metadata[xhttp.AmzObjectTagging]
// Add replication status to the object info
objInfo.ReplicationStatus = replication.StatusType(fi.Metadata[xhttp.AmzBucketReplicationStatus])
// 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-*.
// Tags have also been extracted, we remove that as well.
objInfo.UserDefined = cleanMetadata(fi.Metadata)
// All the parts per object.
objInfo.Parts = fi.Parts
// Update storage class
if sc, ok := fi.Metadata[xhttp.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 (fi *FileInfo) AddObjectPart(partNumber int, partETag string, partSize int64, actualSize int64) {
partInfo := ObjectPartInfo{
Number: partNumber,
ETag: partETag,
Size: partSize,
ActualSize: actualSize,
}
// Update part info if it already exists.
for i, part := range fi.Parts {
if partNumber == part.Number {
fi.Parts[i] = partInfo
return
}
}
// Proceed to include new part info.
fi.Parts = append(fi.Parts, partInfo)
// Parts in FileInfo should be in sorted order by part number.
sort.Sort(byObjectPartNumber(fi.Parts))
}
// ObjectToPartOffset - translate offset of an object to offset of its individual part.
func (fi FileInfo) 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 fi.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 findFileInfoInQuorum(ctx context.Context, metaArr []FileInfo, modTime time.Time, quorum int) (xmv FileInfo, e error) {
metaHashes := make([]string, len(metaArr))
for i, meta := range metaArr {
if meta.IsValid() && meta.ModTime.Equal(modTime) {
h := sha256.New()
for _, part := range meta.Parts {
h.Write([]byte(fmt.Sprintf("part.%d", part.Number)))
}
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 FileInfo{}, errErasureReadQuorum
}
for i, hash := range metaHashes {
if hash == maxHash {
return metaArr[i], nil
}
}
return FileInfo{}, errErasureReadQuorum
}
// pickValidFileInfo - picks one valid FileInfo content and returns from a
// slice of FileInfo.
func pickValidFileInfo(ctx context.Context, metaArr []FileInfo, modTime time.Time, quorum int) (xmv FileInfo, e error) {
return findFileInfoInQuorum(ctx, metaArr, modTime, quorum)
}
// Rename metadata content to destination location for each disk concurrently.
func renameFileInfo(ctx context.Context, disks []StorageAPI, srcBucket, srcEntry, dstBucket, dstEntry string, quorum int) ([]StorageAPI, error) {
ignoredErr := []error{errFileNotFound}
g := errgroup.WithNErrs(len(disks))
// Rename file on all underlying storage disks.
for index := range disks {
index := index
g.Go(func() error {
if disks[index] == nil {
return errDiskNotFound
}
if err := disks[index].RenameData(ctx, srcBucket, srcEntry, "", dstBucket, dstEntry); err != nil {
if !IsErrIgnored(err, ignoredErr...) {
return err
}
}
return nil
}, index)
}
// Wait for all renames to finish.
errs := g.Wait()
// We can safely allow RenameData errors up to len(er.getDisks()) - writeQuorum
// otherwise return failure. Cleanup successful renames.
err := reduceWriteQuorumErrs(ctx, errs, objectOpIgnoredErrs, quorum)
return evalDisks(disks, errs), err
}
// writeUniqueFileInfo - writes unique `xl.meta` content for each disk concurrently.
func writeUniqueFileInfo(ctx context.Context, disks []StorageAPI, bucket, prefix string, files []FileInfo, quorum int) ([]StorageAPI, error) {
g := errgroup.WithNErrs(len(disks))
// Start writing `xl.meta` to all disks in parallel.
for index := range disks {
index := index
g.Go(func() error {
if disks[index] == nil {
return errDiskNotFound
}
// Pick one FileInfo for a disk at index.
files[index].Erasure.Index = index + 1
return disks[index].WriteMetadata(ctx, bucket, prefix, files[index])
}, index)
}
// Wait for all the routines.
mErrs := g.Wait()
err := reduceWriteQuorumErrs(ctx, mErrs, objectOpIgnoredErrs, quorum)
return evalDisks(disks, mErrs), err
}
// Returns per object readQuorum and writeQuorum
// readQuorum is the min required disks to read data.
// writeQuorum is the min required disks to write data.
func objectQuorumFromMeta(ctx context.Context, er erasureObjects, partsMetaData []FileInfo, errs []error) (objectReadQuorum, objectWriteQuorum int, err error) {
// get the latest updated Metadata and a count of all the latest updated FileInfo(s)
latestFileInfo, err := getLatestFileInfo(ctx, partsMetaData, errs)
if err != nil {
return 0, 0, err
}
dataBlocks := latestFileInfo.Erasure.DataBlocks
parityBlocks := globalStorageClass.GetParityForSC(latestFileInfo.Metadata[xhttp.AmzStorageClass])
if parityBlocks == 0 {
parityBlocks = dataBlocks
}
writeQuorum := dataBlocks
if dataBlocks == parityBlocks {
writeQuorum = dataBlocks + 1
}
// Since all the valid erasure code meta updated at the same time are equivalent, pass dataBlocks
// from latestFileInfo to get the quorum
return dataBlocks, writeQuorum, nil
}