k3s/vendor/go.etcd.io/etcd/wal/repair.go

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2020-05-07 05:09:19 +00:00
// Copyright 2015 The etcd Authors
//
// 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 wal
import (
"io"
"os"
"path/filepath"
"time"
"go.etcd.io/etcd/pkg/fileutil"
"go.etcd.io/etcd/wal/walpb"
"go.uber.org/zap"
)
// Repair tries to repair ErrUnexpectedEOF in the
// last wal file by truncating.
func Repair(lg *zap.Logger, dirpath string) bool {
f, err := openLast(lg, dirpath)
if err != nil {
return false
}
defer f.Close()
if lg != nil {
lg.Info("repairing", zap.String("path", f.Name()))
} else {
plog.Noticef("repairing %v", f.Name())
}
rec := &walpb.Record{}
decoder := newDecoder(f)
for {
lastOffset := decoder.lastOffset()
err := decoder.decode(rec)
switch err {
case nil:
// update crc of the decoder when necessary
switch rec.Type {
case crcType:
crc := decoder.crc.Sum32()
// current crc of decoder must match the crc of the record.
// do no need to match 0 crc, since the decoder is a new one at this case.
if crc != 0 && rec.Validate(crc) != nil {
return false
}
decoder.updateCRC(rec.Crc)
}
continue
case io.EOF:
if lg != nil {
lg.Info("repaired", zap.String("path", f.Name()), zap.Error(io.EOF))
}
return true
case io.ErrUnexpectedEOF:
bf, bferr := os.Create(f.Name() + ".broken")
if bferr != nil {
if lg != nil {
lg.Warn("failed to create backup file", zap.String("path", f.Name()+".broken"), zap.Error(bferr))
} else {
plog.Errorf("could not repair %v, failed to create backup file", f.Name())
}
return false
}
defer bf.Close()
if _, err = f.Seek(0, io.SeekStart); err != nil {
if lg != nil {
lg.Warn("failed to read file", zap.String("path", f.Name()), zap.Error(err))
} else {
plog.Errorf("could not repair %v, failed to read file", f.Name())
}
return false
}
if _, err = io.Copy(bf, f); err != nil {
if lg != nil {
lg.Warn("failed to copy", zap.String("from", f.Name()+".broken"), zap.String("to", f.Name()), zap.Error(err))
} else {
plog.Errorf("could not repair %v, failed to copy file", f.Name())
}
return false
}
if err = f.Truncate(lastOffset); err != nil {
if lg != nil {
lg.Warn("failed to truncate", zap.String("path", f.Name()), zap.Error(err))
} else {
plog.Errorf("could not repair %v, failed to truncate file", f.Name())
}
return false
}
start := time.Now()
if err = fileutil.Fsync(f.File); err != nil {
if lg != nil {
lg.Warn("failed to fsync", zap.String("path", f.Name()), zap.Error(err))
} else {
plog.Errorf("could not repair %v, failed to sync file", f.Name())
}
return false
}
walFsyncSec.Observe(time.Since(start).Seconds())
if lg != nil {
lg.Info("repaired", zap.String("path", f.Name()), zap.Error(io.ErrUnexpectedEOF))
}
return true
default:
if lg != nil {
lg.Warn("failed to repair", zap.String("path", f.Name()), zap.Error(err))
} else {
plog.Errorf("could not repair error (%v)", err)
}
return false
}
}
}
// openLast opens the last wal file for read and write.
func openLast(lg *zap.Logger, dirpath string) (*fileutil.LockedFile, error) {
names, err := readWALNames(lg, dirpath)
if err != nil {
return nil, err
}
last := filepath.Join(dirpath, names[len(names)-1])
return fileutil.LockFile(last, os.O_RDWR, fileutil.PrivateFileMode)
}