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 15package wal 16 17import ( 18 "fmt" 19 "io" 20 "io/ioutil" 21 "os" 22 "testing" 23 24 "github.com/coreos/etcd/raft/raftpb" 25 "github.com/coreos/etcd/wal/walpb" 26) 27 28type corruptFunc func(string, int64) error 29 30// TestRepairTruncate ensures a truncated file can be repaired 31func TestRepairTruncate(t *testing.T) { 32 corruptf := func(p string, offset int64) error { 33 f, err := openLast(p) 34 if err != nil { 35 return err 36 } 37 defer f.Close() 38 return f.Truncate(offset - 4) 39 } 40 41 testRepair(t, makeEnts(10), corruptf, 9) 42} 43 44func testRepair(t *testing.T, ents [][]raftpb.Entry, corrupt corruptFunc, expectedEnts int) { 45 p, err := ioutil.TempDir(os.TempDir(), "waltest") 46 if err != nil { 47 t.Fatal(err) 48 } 49 defer os.RemoveAll(p) 50 // create WAL 51 w, err := Create(p, nil) 52 defer func() { 53 if err = w.Close(); err != nil { 54 t.Fatal(err) 55 } 56 }() 57 if err != nil { 58 t.Fatal(err) 59 } 60 61 for _, es := range ents { 62 if err = w.Save(raftpb.HardState{}, es); err != nil { 63 t.Fatal(err) 64 } 65 } 66 67 offset, err := w.tail().Seek(0, io.SeekCurrent) 68 if err != nil { 69 t.Fatal(err) 70 } 71 w.Close() 72 73 err = corrupt(p, offset) 74 if err != nil { 75 t.Fatal(err) 76 } 77 78 // verify we broke the wal 79 w, err = Open(p, walpb.Snapshot{}) 80 if err != nil { 81 t.Fatal(err) 82 } 83 _, _, _, err = w.ReadAll() 84 if err != io.ErrUnexpectedEOF { 85 t.Fatalf("err = %v, want error %v", err, io.ErrUnexpectedEOF) 86 } 87 w.Close() 88 89 // repair the wal 90 if ok := Repair(p); !ok { 91 t.Fatalf("fix = %t, want %t", ok, true) 92 } 93 94 // read it back 95 w, err = Open(p, walpb.Snapshot{}) 96 if err != nil { 97 t.Fatal(err) 98 } 99 _, _, walEnts, err := w.ReadAll() 100 if err != nil { 101 t.Fatal(err) 102 } 103 if len(walEnts) != expectedEnts { 104 t.Fatalf("len(ents) = %d, want %d", len(walEnts), expectedEnts) 105 } 106 107 // write some more entries to repaired log 108 for i := 1; i <= 10; i++ { 109 es := []raftpb.Entry{{Index: uint64(expectedEnts + i)}} 110 if err = w.Save(raftpb.HardState{}, es); err != nil { 111 t.Fatal(err) 112 } 113 } 114 w.Close() 115 116 // read back entries following repair, ensure it's all there 117 w, err = Open(p, walpb.Snapshot{}) 118 if err != nil { 119 t.Fatal(err) 120 } 121 _, _, walEnts, err = w.ReadAll() 122 if err != nil { 123 t.Fatal(err) 124 } 125 if len(walEnts) != expectedEnts+10 { 126 t.Fatalf("len(ents) = %d, want %d", len(walEnts), expectedEnts+10) 127 } 128} 129 130func makeEnts(ents int) (ret [][]raftpb.Entry) { 131 for i := 1; i <= ents; i++ { 132 ret = append(ret, []raftpb.Entry{{Index: uint64(i)}}) 133 } 134 return ret 135} 136 137// TestRepairWriteTearLast repairs the WAL in case the last record is a torn write 138// that straddled two sectors. 139func TestRepairWriteTearLast(t *testing.T) { 140 corruptf := func(p string, offset int64) error { 141 f, err := openLast(p) 142 if err != nil { 143 return err 144 } 145 defer f.Close() 146 // 512 bytes perfectly aligns the last record, so use 1024 147 if offset < 1024 { 148 return fmt.Errorf("got offset %d, expected >1024", offset) 149 } 150 if terr := f.Truncate(1024); terr != nil { 151 return terr 152 } 153 if terr := f.Truncate(offset); terr != nil { 154 return terr 155 } 156 return nil 157 } 158 testRepair(t, makeEnts(50), corruptf, 40) 159} 160 161// TestRepairWriteTearMiddle repairs the WAL when there is write tearing 162// in the middle of a record. 163func TestRepairWriteTearMiddle(t *testing.T) { 164 corruptf := func(p string, offset int64) error { 165 f, err := openLast(p) 166 if err != nil { 167 return err 168 } 169 defer f.Close() 170 // corrupt middle of 2nd record 171 _, werr := f.WriteAt(make([]byte, 512), 4096+512) 172 return werr 173 } 174 ents := makeEnts(5) 175 // 4096 bytes of data so a middle sector is easy to corrupt 176 dat := make([]byte, 4096) 177 for i := range dat { 178 dat[i] = byte(i) 179 } 180 for i := range ents { 181 ents[i][0].Data = dat 182 } 183 testRepair(t, ents, corruptf, 1) 184} 185