minio/cmd/bucket-meta.go

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/*
* MinIO Cloud Storage, (C) 2020 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/binary"
"errors"
"fmt"
"path"
"time"
"github.com/minio/minio/cmd/logger"
)
const (
legacyBucketObjectLockEnabledConfigFile = "object-lock-enabled.json"
legacyBucketObjectLockEnabledConfig = `{"x-amz-bucket-object-lock-enabled":true}`
bucketMetadataFile = ".metadata.bin"
bucketMetadataFormat = 1
bucketMetadataVersion = 1
)
//go:generate msgp -file $GOFILE -unexported
// bucketMetadata contains bucket metadata.
// When adding/removing fields, regenerate the marshal code using the go generate above.
// Only changing meaning of fields requires a version bump.
// bucketMetadataFormat refers to the format.
// bucketMetadataVersion can be used to track a rolling upgrade of a field.
type bucketMetadata struct {
Name string
Created time.Time
LockEnabled bool
}
// newBucketMetadata creates bucketMetadata with the supplied name and Created to Now.
func newBucketMetadata(name string) bucketMetadata {
return bucketMetadata{
Name: name,
Created: UTCNow(),
}
}
// loadBucketMeta loads the metadata of bucket by name from ObjectLayer o.
// If an error is returned the returned metadata will be default initialized.
func loadBucketMeta(ctx context.Context, o ObjectLayer, name string) (bucketMetadata, error) {
b := newBucketMetadata(name)
configFile := path.Join(bucketConfigPrefix, name, bucketMetadataFile)
data, err := readConfig(ctx, o, configFile)
if err != nil {
return b, err
}
if len(data) <= 4 {
return b, fmt.Errorf("loadBucketMetadata: no data")
}
// Read header
switch binary.LittleEndian.Uint16(data[0:2]) {
case bucketMetadataFormat:
default:
return b, fmt.Errorf("loadBucketMetadata: unknown format: %d", binary.LittleEndian.Uint16(data[0:2]))
}
switch binary.LittleEndian.Uint16(data[2:4]) {
case bucketMetadataVersion:
default:
return b, fmt.Errorf("loadBucketMetadata: unknown version: %d", binary.LittleEndian.Uint16(data[2:4]))
}
// OK, parse data.
_, err = b.UnmarshalMsg(data[4:])
return b, err
}
var errMetaDataConverted = errors.New("metadata converted")
// loadBucketMetadata loads and migrates to bucket metadata.
func loadBucketMetadata(ctx context.Context, objectAPI ObjectLayer, bucket string) (bucketMetadata, error) {
meta, err := loadBucketMeta(ctx, objectAPI, bucket)
if err == nil {
return meta, nil
}
if err != errConfigNotFound {
return meta, err
}
// Control here means old bucket without bucket metadata. Hence we migrate existing settings.
if err = meta.convertLegacyLockconfig(ctx, objectAPI); err != nil {
return meta, err
}
return meta, errMetaDataConverted
}
func (b *bucketMetadata) convertLegacyLockconfig(ctx context.Context, objectAPI ObjectLayer) error {
configFile := path.Join(bucketConfigPrefix, b.Name, legacyBucketObjectLockEnabledConfigFile)
save := func() error {
if err := b.save(ctx, objectAPI); err != nil {
return err
}
if err := deleteConfig(ctx, objectAPI, configFile); err != nil && !errors.Is(err, errConfigNotFound) {
logger.LogIf(ctx, err)
}
return nil
}
configData, err := readConfig(ctx, objectAPI, configFile)
if err != nil {
if !errors.Is(err, errConfigNotFound) {
return err
}
return save()
}
if string(configData) != legacyBucketObjectLockEnabledConfig {
return fmt.Errorf("content mismatch in config file %v", configFile)
}
b.LockEnabled = true
return save()
}
// save config to supplied ObjectLayer o.
func (b *bucketMetadata) save(ctx context.Context, o ObjectLayer) error {
data := make([]byte, 4, b.Msgsize()+4)
// Put header
binary.LittleEndian.PutUint16(data[0:2], bucketMetadataFormat)
binary.LittleEndian.PutUint16(data[2:4], bucketMetadataVersion)
// Add data
data, err := b.MarshalMsg(data)
if err != nil {
return err
}
configFile := path.Join(bucketConfigPrefix, b.Name, bucketMetadataFile)
return saveConfig(ctx, o, configFile, data)
}
// delete the config metadata.
// If config does not exist no error is returned.
func (b bucketMetadata) delete(ctx context.Context, o ObjectLayer) error {
configFile := path.Join(bucketConfigPrefix, b.Name, bucketMetadataFile)
err := deleteConfig(ctx, o, configFile)
if err == errConfigNotFound {
// We don't care
err = nil
}
return err
}