fix db.grow is unusable when NoFreelistSync is on

Signed-off-by: tian <[email protected]>

db.go

@@ -1120,7 +1120,7 @@ func (db *DB) grow(sz int) error {
 
  // If the data is smaller than the alloc size then only allocate what's needed.
  // Once it goes over the allocation size then allocate in chunks.
- if db.datasz < db.AllocSize {
+ if db.datasz <= db.AllocSize {
  sz = db.datasz
  } else {
  sz += db.AllocSize

tx.go

@@ -156,6 +156,8 @@ func (tx *Tx) Commit() error {
  tx.stats.IncRebalanceTime(time.Since(startTime))
  }
 
+ opgid := tx.meta.pgid
+
  // spill data onto dirty pages.
  startTime = time.Now()
  if err := tx.root.spill(); err != nil {
@@ -181,6 +183,14 @@ func (tx *Tx) Commit() error {
  tx.meta.freelist = pgidNoFreelist
  }
 
+ // If the high water mark has moved up then attempt to grow the database.
+ if tx.meta.pgid > opgid {
+ if err := tx.db.grow(int(tx.meta.pgid+1) * tx.db.pageSize); err != nil {
+ tx.rollback()
+ return err
+ }
+ }
+
  // Write dirty pages to disk.
  startTime = time.Now()
  if err := tx.write(); err != nil {
@@ -225,7 +235,6 @@ func (tx *Tx) Commit() error {
 func (tx *Tx) commitFreelist() error {
  // Allocate new pages for the new free list. This will overestimate
  // the size of the freelist but not underestimate the size (which would be bad).
- opgid := tx.meta.pgid
  p, err := tx.allocate((tx.db.freelist.size() / tx.db.pageSize) + 1)
  if err != nil {
  tx.rollback()
@@ -236,13 +245,6 @@ func (tx *Tx) commitFreelist() error {
  return err
  }
  tx.meta.freelist = p.id
- // If the high water mark has moved up then attempt to grow the database.
- if tx.meta.pgid > opgid {
- if err := tx.db.grow(int(tx.meta.pgid+1) * tx.db.pageSize); err != nil {
- tx.rollback()
- return err
- }
- }
 
  return nil
 }

tx_test.go

@@ -6,10 +6,12 @@ import (
  "fmt"
  "log"
  "os"
+ "runtime"
  "testing"
  "time"
 
  "github.com/stretchr/testify/assert"
+ "github.com/stretchr/testify/require"
 
  bolt "go.etcd.io/bbolt"
  "go.etcd.io/bbolt/internal/btesting"
@@ -1009,3 +1011,45 @@ func TestTxStats_Sub(t *testing.T) {
  assert.Equal(t, int64(10001), diff.GetWrite())
  assert.Equal(t, 10009*time.Second, diff.GetWriteTime())
 }
+
+// TestTx_TruncateBeforeWrite ensures the file is truncated ahead whether we sync freelist or not.
+func TestTx_TruncateBeforeWrite(t *testing.T) {
+ if runtime.GOOS == "windows" {
+ return
+ }
+ for _, isSyncFreelist := range []bool{false, true} {
+ t.Run(fmt.Sprintf("isSyncFreelist:%v", isSyncFreelist), func(t *testing.T) {
+ // Open the database.
+ db := btesting.MustCreateDBWithOption(t, &bolt.Options{
+ NoFreelistSync: isSyncFreelist,
+ })
+
+ bigvalue := make([]byte, db.AllocSize/100)
+ count := 0
+ for {
+ count++
+ tx, err := db.Begin(true)
+ require.NoError(t, err)
+ b, err := tx.CreateBucketIfNotExists([]byte("bucket"))
+ require.NoError(t, err)
+ err = b.Put([]byte{byte(count)}, bigvalue)
+ require.NoError(t, err)
+ err = tx.Commit()
+ require.NoError(t, err)
+
+ size := fileSize(db.Path())
+
+ if size > int64(db.AllocSize) && size < int64(db.AllocSize)*2 {
+ // db.grow expands the file aggresively, that double the size while smaller than db.AllocSize,
+ // or increase with a step of db.AllocSize if larger, by which we can test if db.grow has run.
+ t.Fatalf("db.grow doesn't run when file size changes. file size: %d", size)
+ }
+ if size > int64(db.AllocSize) {
+ break
+ }
+ }
+ db.MustClose()
+ db.MustDeleteFile()
+ })
+ }
+}