khenaidoo | 2672188 | 2021-08-11 17:42:52 -0400 | [diff] [blame] | 1 | // Copyright 2015 The etcd Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package wal |
| 16 | |
| 17 | import ( |
| 18 | "io" |
| 19 | "os" |
| 20 | "path/filepath" |
| 21 | "time" |
| 22 | |
| 23 | "github.com/coreos/etcd/pkg/fileutil" |
| 24 | "github.com/coreos/etcd/wal/walpb" |
| 25 | ) |
| 26 | |
| 27 | // Repair tries to repair ErrUnexpectedEOF in the |
| 28 | // last wal file by truncating. |
| 29 | func Repair(dirpath string) bool { |
| 30 | f, err := openLast(dirpath) |
| 31 | if err != nil { |
| 32 | return false |
| 33 | } |
| 34 | defer f.Close() |
| 35 | |
| 36 | rec := &walpb.Record{} |
| 37 | decoder := newDecoder(f) |
| 38 | for { |
| 39 | lastOffset := decoder.lastOffset() |
| 40 | err := decoder.decode(rec) |
| 41 | switch err { |
| 42 | case nil: |
| 43 | // update crc of the decoder when necessary |
| 44 | switch rec.Type { |
| 45 | case crcType: |
| 46 | crc := decoder.crc.Sum32() |
| 47 | // current crc of decoder must match the crc of the record. |
| 48 | // do no need to match 0 crc, since the decoder is a new one at this case. |
| 49 | if crc != 0 && rec.Validate(crc) != nil { |
| 50 | return false |
| 51 | } |
| 52 | decoder.updateCRC(rec.Crc) |
| 53 | } |
| 54 | continue |
| 55 | case io.EOF: |
| 56 | return true |
| 57 | case io.ErrUnexpectedEOF: |
| 58 | plog.Noticef("repairing %v", f.Name()) |
| 59 | bf, bferr := os.Create(f.Name() + ".broken") |
| 60 | if bferr != nil { |
| 61 | plog.Errorf("could not repair %v, failed to create backup file", f.Name()) |
| 62 | return false |
| 63 | } |
| 64 | defer bf.Close() |
| 65 | |
| 66 | if _, err = f.Seek(0, io.SeekStart); err != nil { |
| 67 | plog.Errorf("could not repair %v, failed to read file", f.Name()) |
| 68 | return false |
| 69 | } |
| 70 | |
| 71 | if _, err = io.Copy(bf, f); err != nil { |
| 72 | plog.Errorf("could not repair %v, failed to copy file", f.Name()) |
| 73 | return false |
| 74 | } |
| 75 | |
| 76 | if err = f.Truncate(int64(lastOffset)); err != nil { |
| 77 | plog.Errorf("could not repair %v, failed to truncate file", f.Name()) |
| 78 | return false |
| 79 | } |
| 80 | |
| 81 | start := time.Now() |
| 82 | if err = fileutil.Fsync(f.File); err != nil { |
| 83 | plog.Errorf("could not repair %v, failed to sync file", f.Name()) |
| 84 | return false |
| 85 | } |
| 86 | syncDurations.Observe(time.Since(start).Seconds()) |
| 87 | |
| 88 | return true |
| 89 | default: |
| 90 | plog.Errorf("could not repair error (%v)", err) |
| 91 | return false |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | // openLast opens the last wal file for read and write. |
| 97 | func openLast(dirpath string) (*fileutil.LockedFile, error) { |
| 98 | names, err := readWalNames(dirpath) |
| 99 | if err != nil { |
| 100 | return nil, err |
| 101 | } |
| 102 | last := filepath.Join(dirpath, names[len(names)-1]) |
| 103 | return fileutil.LockFile(last, os.O_RDWR, fileutil.PrivateFileMode) |
| 104 | } |