*: replace os.FileInfo with os.DirEntry where possible

Previously, in a few places, we converted os.DirEntry to os.FileInfo by
calling entry.Info(), which triggers a stat syscall for each entry.

Most callers only needed the entry name, which is directly available from
os.DirEntry via Name(). This patch switches to os.DirEntry throughout the
codebase, avoiding unnecessary stat syscalls. In the few places where file
size or mode is needed, we now call Info() only when required.

Epic: none
Release note: None
Fixes: none

Author: shubhamdhama

pkg/security/securityassets/security_assets.go

@@ -6,22 +6,21 @@
 package securityassets
 
 import (
-	"io/fs"
 	"os"
 
 	"github.com/cockroachdb/errors/oserror"
 )
 
 // Loader describes the functions necessary to read certificate and key files.
 type Loader struct {
-	ReadDir  func(dirname string) ([]os.FileInfo, error)
+	ReadDir  func(dirname string) ([]os.DirEntry, error)
 	ReadFile func(filename string) ([]byte, error)
 	Stat     func(name string) (os.FileInfo, error)
 }
 
 // defaultLoader uses real filesystem calls.
 var defaultLoader = Loader{
-	ReadDir:  readDir,
+	ReadDir:  os.ReadDir,
 	ReadFile: os.ReadFile,
 	Stat:     os.Stat,
 }
@@ -55,29 +54,3 @@ func (al Loader) FileExists(filename string) (bool, error) {
 	}
 	return true, nil
 }
-
-// readDir reads the directory named by dirname and returns a list of
-// fs.FileInfo for the directory's contents, sorted by filename. If an error
-// occurs reading the directory, ReadDir returns no directory entries along with
-// the error.
-func readDir(dirname string) ([]os.FileInfo, error) {
-	entries, err := os.ReadDir(dirname)
-	if err != nil {
-		return nil, err
-	}
-	infos := make([]fs.FileInfo, 0, len(entries))
-	for _, entry := range entries {
-		info, err := entry.Info()
-		if err != nil {
-			// Skip files that disappeared between ReadDir and Info().
-			// This can happen when the directory contains transient files
-			// like Unix socket lock files that are created/deleted rapidly.
-			if oserror.IsNotExist(err) {
-				continue
-			}
-			return nil, err
-		}
-		infos = append(infos, info)
-	}
-	return infos, nil
-}

pkg/security/securitytest/securitytest.go

@@ -96,27 +96,23 @@ func AppendFile(assetPath, dstPath string) error {
 	return errors.CombineErrors(err, f.Close())
 }
 
-// AssetReadDir mimics ioutil.ReadDir, returning a list of []os.FileInfo for
-// the specified directory.
-func AssetReadDir(name string) ([]os.FileInfo, error) {
+// AssetReadDir mimics os.ReadDir, returning a list of []os.DirEntry for the
+// specified directory.
+func AssetReadDir(name string) ([]os.DirEntry, error) {
 	entries, err := testCerts.ReadDir(name)
 	if err != nil {
 		return nil, err
 	}
-	infos := make([]os.FileInfo, 0, len(entries))
+	filtered_entries := make([]os.DirEntry, 0, len(entries))
 	for _, e := range entries {
-		info, err := e.Info()
-		if err != nil {
-			return nil, err
-		}
 		if strings.HasSuffix(e.Name(), ".md") ||
 			strings.HasSuffix(e.Name(), ".sh") ||
 			strings.HasSuffix(e.Name(), ".cnf") {
 			continue
 		}
-		infos = append(infos, &fileInfo{inner: info})
+		filtered_entries = append(filtered_entries, e)
 	}
-	return infos, nil
+	return filtered_entries, nil
 }
 
 // AssetStat wraps Stat().

pkg/server/dumpstore/BUILD.bazel

@@ -9,6 +9,7 @@ go_library(
         "//pkg/settings",
         "//pkg/settings/cluster",
         "//pkg/util/log",
+        "@com_github_cockroachdb_errors//oserror",
     ],
 )
 

pkg/server/dumpstore/dumpstore.go

@@ -7,14 +7,14 @@ package dumpstore
 
 import (
 	"context"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/settings"
 	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
+	"github.com/cockroachdb/errors/oserror"
 )
 
 // DumpStore represents a store for dump files.
@@ -59,10 +59,10 @@ type Dumper interface {
 	//
 	// There may be files not owned by this dumper in the files array;
 	// these should be ignored.
-	PreFilter(ctx context.Context, files []os.FileInfo, cleanupFn func(fileName string) error) (preserved map[int]bool, err error)
+	PreFilter(ctx context.Context, files []os.DirEntry, cleanupFn func(fileName string) error) (preserved map[int]bool, err error)
 
 	// CheckOwnsFile returns true iff the dumper owns the given file.
-	CheckOwnsFile(ctx context.Context, fi os.FileInfo) bool
+	CheckOwnsFile(ctx context.Context, fi os.DirEntry) bool
 }
 
 // NewStore creates a new DumpStore.
@@ -83,22 +83,13 @@ func (s *DumpStore) GetFullPath(fileName string) string {
 
 // GC runs the GC policy on this store.
 func (s *DumpStore) GC(ctx context.Context, now time.Time, dumper Dumper) {
-	// NB: ioutil.ReadDir sorts the file names in ascending order.
+	// NB: os.ReadDir sorts the file names in ascending order.
 	// This brings the oldest files first.
-	entries, err := os.ReadDir(s.dir)
+	files, err := os.ReadDir(s.dir)
 	if err != nil {
 		log.Dev.Warningf(ctx, "%v", err)
 		return
 	}
-	files := make([]fs.FileInfo, 0, len(entries))
-	for _, entry := range entries {
-		info, err := entry.Info()
-		if err != nil {
-			log.Dev.Warningf(ctx, "%v", err)
-			return
-		}
-		files = append(files, info)
-	}
 
 	maxS := s.maxCombinedFileSizeSetting.Get(&s.st.SV)
 
@@ -129,7 +120,7 @@ func (s *DumpStore) GC(ctx context.Context, now time.Time, dumper Dumper) {
 func removeOldAndTooBigExcept(
 	ctx context.Context,
 	dumper Dumper,
-	files []os.FileInfo,
+	files []os.DirEntry,
 	now time.Time,
 	maxS int64,
 	preserved map[int]bool,
@@ -144,8 +135,16 @@ func removeOldAndTooBigExcept(
 			continue
 		}
 
+		info, err := fi.Info()
+		if err != nil {
+			if !oserror.IsNotExist(err) {
+				log.Dev.Warningf(ctx, "%v", err)
+			}
+			continue
+		}
+
 		// Note: we are counting preserved files against the maximum.
-		actualSize += fi.Size()
+		actualSize += info.Size()
 
 		// Ignore all the preserved entries, even if they are "too old".
 		if preserved[i] {

pkg/server/dumpstore/dumpstore_test.go

@@ -8,7 +8,6 @@ package dumpstore
 import (
 	"context"
 	"fmt"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -156,16 +155,16 @@ func TestRemoveOldAndTooBig(t *testing.T) {
 type myDumper struct{}
 
 func (myDumper) PreFilter(
-	_ context.Context, files []os.FileInfo, cleanupFn func(fileName string) error,
+	_ context.Context, files []os.DirEntry, cleanupFn func(fileName string) error,
 ) (preserved map[int]bool, err error) {
 	panic("unimplemented")
 }
 
-func (myDumper) CheckOwnsFile(_ context.Context, fi os.FileInfo) bool {
+func (myDumper) CheckOwnsFile(_ context.Context, fi os.DirEntry) bool {
 	return strings.HasPrefix(fi.Name(), "memprof")
 }
 
-func populate(t *testing.T, dirName string, fileNames []string, sizes []int64) []os.FileInfo {
+func populate(t *testing.T, dirName string, fileNames []string, sizes []int64) []os.DirEntry {
 	if len(sizes) > 0 {
 		require.Equal(t, len(fileNames), len(sizes))
 	}
@@ -187,17 +186,9 @@ func populate(t *testing.T, dirName string, fileNames []string, sizes []int64) [
 	}
 
 	// Retrieve the file list for the remainder of the test.
-	entries, err := os.ReadDir(dirName)
+	files, err := os.ReadDir(dirName)
 	if err != nil {
 		t.Fatal(err)
 	}
-	files := make([]fs.FileInfo, 0, len(entries))
-	for _, entry := range entries {
-		info, err := entry.Info()
-		if err != nil {
-			t.Fatal(err)
-		}
-		files = append(files, info)
-	}
 	return files
 }

pkg/server/goroutinedumper/goroutinedumper.go

@@ -136,7 +136,7 @@ func (gd *GoroutineDumper) gcDumps(ctx context.Context, now time.Time) {
 
 // PreFilter is part of the dumpstore.Dumper interface.
 func (gd *GoroutineDumper) PreFilter(
-	ctx context.Context, files []os.FileInfo, cleanupFn func(fileName string) error,
+	ctx context.Context, files []os.DirEntry, cleanupFn func(fileName string) error,
 ) (preserved map[int]bool, _ error) {
 	preserved = make(map[int]bool)
 	for i := len(files) - 1; i >= 0; i-- {
@@ -150,7 +150,7 @@ func (gd *GoroutineDumper) PreFilter(
 }
 
 // CheckOwnsFile is part of the dumpstore.Dumper interface.
-func (gd *GoroutineDumper) CheckOwnsFile(_ context.Context, fi os.FileInfo) bool {
+func (gd *GoroutineDumper) CheckOwnsFile(_ context.Context, fi os.DirEntry) bool {
 	return strings.HasPrefix(fi.Name(), goroutineDumpPrefix)
 }
 

pkg/server/profiler/profilestore.go

@@ -67,15 +67,15 @@ func (s *profileStore) makeNewFileName(timestamp time.Time, curHeap int64) strin
 
 // PreFilter is part of the dumpstore.Dumper interface.
 func (s *profileStore) PreFilter(
-	ctx context.Context, files []os.FileInfo, cleanupFn func(fileName string) error,
+	ctx context.Context, files []os.DirEntry, cleanupFn func(fileName string) error,
 ) (preserved map[int]bool, _ error) {
 	maxP := maxProfiles.Get(&s.st.SV)
 	preserved = s.cleanupLastRampup(ctx, files, maxP, cleanupFn)
 	return
 }
 
 // CheckOwnsFile is part of the dumpstore.Dumper interface.
-func (s *profileStore) CheckOwnsFile(ctx context.Context, fi os.FileInfo) bool {
+func (s *profileStore) CheckOwnsFile(ctx context.Context, fi os.DirEntry) bool {
 	ok, _, _ := s.parseFileName(ctx, fi.Name())
 	return ok
 }
@@ -91,7 +91,7 @@ func (s *profileStore) CheckOwnsFile(ctx context.Context, fi os.FileInfo) bool {
 // The preserved return value contains the indexes in files
 // corresponding to the last ramp-up that were not passed to fn.
 func (s *profileStore) cleanupLastRampup(
-	ctx context.Context, files []os.FileInfo, maxP int64, fn func(string) error,
+	ctx context.Context, files []os.DirEntry, maxP int64, fn func(string) error,
 ) (preserved map[int]bool) {
 	preserved = make(map[int]bool)
 	curMaxHeap := uint64(math.MaxUint64)

pkg/server/profiler/profilestore_test.go

@@ -8,7 +8,6 @@ package profiler
 import (
 	"context"
 	"fmt"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"testing"
@@ -208,7 +207,7 @@ func TestCleanupLastRampup(t *testing.T) {
 	}
 }
 
-func populate(t *testing.T, dirName string, fileNames []string) []os.FileInfo {
+func populate(t *testing.T, dirName string, fileNames []string) []os.DirEntry {
 	for _, fn := range fileNames {
 		f, err := os.Create(filepath.Join(dirName, fn))
 		if err != nil {
@@ -221,17 +220,9 @@ func populate(t *testing.T, dirName string, fileNames []string) []os.FileInfo {
 	}
 
 	// Retrieve the file list for the remainder of the test.
-	entries, err := os.ReadDir(dirName)
+	files, err := os.ReadDir(dirName)
 	if err != nil {
 		t.Fatal(err)
 	}
-	files := make([]fs.FileInfo, 0, len(entries))
-	for _, entry := range entries {
-		info, err := entry.Info()
-		if err != nil {
-			t.Fatal(err)
-		}
-		files = append(files, info)
-	}
 	return files
 }

pkg/server/tracedumper/tracedumper.go

@@ -33,7 +33,7 @@ type TraceDumper struct {
 
 // PreFilter is part of the dumpstore.Dumper interface.
 func (t *TraceDumper) PreFilter(
-	ctx context.Context, files []os.FileInfo, _ func(fileName string) error,
+	ctx context.Context, files []os.DirEntry, _ func(fileName string) error,
 ) (preserved map[int]bool, err error) {
 	preserved = make(map[int]bool)
 	for i := len(files) - 1; i >= 0; i-- {
@@ -47,7 +47,7 @@ func (t *TraceDumper) PreFilter(
 }
 
 // CheckOwnsFile is part of the dumpstore.Dumper interface.
-func (t *TraceDumper) CheckOwnsFile(ctx context.Context, fi os.FileInfo) bool {
+func (t *TraceDumper) CheckOwnsFile(ctx context.Context, fi os.DirEntry) bool {
 	return strings.HasPrefix(fi.Name(), jobTraceDumpPrefix)
 }
 

pkg/util/tracing/goexectrace/simple_flight_recorder.go

@@ -103,14 +103,14 @@ func (sfr *SimpleFlightRecorder) TimestampedFilename() string {
 var fileMatchRegexp = regexp.MustCompile("^executiontrace.*out$")
 
 // CheckOwnsFile is part of the `Dumper` interface.
-func (sfr *SimpleFlightRecorder) CheckOwnsFile(ctx context.Context, fi os.FileInfo) bool {
+func (sfr *SimpleFlightRecorder) CheckOwnsFile(ctx context.Context, fi os.DirEntry) bool {
 	return fileMatchRegexp.MatchString(fi.Name())
 }
 
 // PreFilter is part of the `Dumper` interface. In this case we do not mark any
 // files for preservation.
 func (sfr *SimpleFlightRecorder) PreFilter(
-	ctx context.Context, files []os.FileInfo, cleanupFn func(fileName string) error,
+	ctx context.Context, files []os.DirEntry, cleanupFn func(fileName string) error,
 ) (preserved map[int]bool, err error) {
 	return nil, nil
 }