refactor: replace filepath.Walk with filepath.WalkDir

filepath.WalkDir, introduced in Go 1.16, is more performant as it avoids creating
unnecessary intermediate os.FileInfo objects. While filepath.Walk calls os.Lstat for every file or directory
to retrieve os.FileInfo, filepath.WalkDir provides a fs.DirEntry, which includes file
type information without requiring a stat call.

This change reduces unnecessary system calls and aligns with modern Go practices
for directory traversal.

Epic: None

Release note (performance improvement): Improved directory traversal performance by switching from filepath.Walk to filepath.WalkDir.

pkg/backup/full_cluster_backup_restore_test.go

@@ -10,6 +10,7 @@ import (
 	gosql "database/sql"
 	"fmt"
 	"os"
+	"io/fs"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -667,14 +668,14 @@ func TestClusterRestoreFailCleanup(t *testing.T) {
 
 	// Bugger the backup by removing the SST files. (Note this messes up all of
 	// the backups, but there is only one at this point.)
-	if err := filepath.Walk(tempDir, func(path string, info os.FileInfo, err error) error {
+	if err := filepath.WalkDir(tempDir, func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
 			t.Fatal(err)
 		}
-		if info.Name() == backupbase.BackupManifestName ||
+		if d.Name() == backupbase.BackupManifestName ||
 			!strings.HasSuffix(path, ".sst") ||
-			info.Name() == backupinfo.BackupMetadataDescriptorsListPath ||
-			info.Name() == backupinfo.BackupMetadataFilesListPath {
+			d.Name() == backupinfo.BackupMetadataDescriptorsListPath ||
+			d.Name() == backupinfo.BackupMetadataFilesListPath {
 			return nil
 		}
 		return os.Remove(path)

pkg/blobs/local_storage.go

@@ -8,6 +8,7 @@ package blobs
 import (
 	"context"
 	"io"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -186,11 +187,11 @@ func (l *LocalStorage) List(pattern string) ([]string, error) {
 			}
 		}
 
-		if err := filepath.Walk(walkRoot, func(p string, f os.FileInfo, err error) error {
+		if err := filepath.WalkDir(walkRoot, func(p string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
-			if f.IsDir() {
+			if d.IsDir() {
 				return nil
 			}
 			if listingParent && !strings.HasPrefix(p, fullPath) {

pkg/ccl/changefeedccl/sink_cloudstorage_test.go

@@ -10,6 +10,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"io/fs"
 	"math"
 	"net/url"
 	"os"
@@ -111,33 +112,33 @@ func TestCloudStorageSink(t *testing.T) {
 			return false
 		}
 
-		walkFn := func(path string, info os.FileInfo, err error) error {
+		walkDirFn := func(path string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
 			if path == absRoot {
 				return nil
 			}
-			if info.IsDir() && !hasChildDirs(path) {
+			if d.IsDir() && !hasChildDirs(path) {
 				relPath, _ := filepath.Rel(absRoot, path)
 				folders = append(folders, relPath)
 			}
 			return nil
 		}
 
-		require.NoError(t, filepath.Walk(absRoot, walkFn))
+		require.NoError(t, filepath.WalkDir(absRoot, walkDirFn))
 		return folders
 	}
 
 	// slurpDir returns the contents of every file under root (relative to the
 	// temp dir created above), sorted by the name of the file.
 	slurpDir := func(t *testing.T) []string {
 		var files []string
-		walkFn := func(path string, info os.FileInfo, err error) error {
+		walkDirFn := func(path string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
-			if info.IsDir() {
+			if d.IsDir() {
 				return nil
 			}
 			file, err := os.ReadFile(path)
@@ -152,7 +153,7 @@ func TestCloudStorageSink(t *testing.T) {
 		}
 		absRoot := filepath.Join(externalIODir, testDir(t))
 		require.NoError(t, os.MkdirAll(absRoot, 0755))
-		require.NoError(t, filepath.Walk(absRoot, walkFn))
+		require.NoError(t, filepath.WalkDir(absRoot, walkDirFn))
 		return files
 	}
 

pkg/ccl/changefeedccl/testfeed_test.go

@@ -13,6 +13,7 @@ import (
 	"encoding/base64"
 	gojson "encoding/json"
 	"fmt"
+	"io/fs"
 	"math/rand"
 	"net/url"
 	"os"
@@ -1493,13 +1494,13 @@ func (c *cloudFeed) Next() (*cdctest.TestFeedMessage, error) {
 			return nil, err
 		}
 
-		if err := filepath.Walk(c.dir, c.walkDir); err != nil {
+		if err := filepath.WalkDir(c.dir, c.walkDir); err != nil {
 			return nil, err
 		}
 	}
 }
 
-func (c *cloudFeed) walkDir(path string, info os.FileInfo, err error) error {
+func (c *cloudFeed) walkDir(path string, d fs.DirEntry, err error) error {
 	if strings.HasSuffix(path, `.tmp`) {
 		// File in the process of being written by ExternalStorage. Ignore.
 		return nil
@@ -1520,7 +1521,7 @@ func (c *cloudFeed) walkDir(path string, info os.FileInfo, err error) error {
 		return err
 	}
 
-	if info.IsDir() {
+	if d.IsDir() {
 		// Nothing to do for directories.
 		return nil
 	}

pkg/cli/debug_merge_logs.go

@@ -11,6 +11,7 @@ import (
 	"container/heap"
 	"context"
 	"io"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -349,12 +350,11 @@ func findLogFiles(
 	}
 	var files []fileInfo
 	for _, p := range paths {
-		// NB: come go1.16, we should use WalkDir here as it is more efficient.
-		if err := filepath.Walk(p, func(p string, info os.FileInfo, err error) error {
+		if err := filepath.WalkDir(p, func(p string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
-			if info.IsDir() {
+			if d.IsDir() {
 				// Don't act on the directory itself, Walk will visit it for us.
 				return nil
 			}

pkg/cli/gen_test.go

@@ -7,6 +7,7 @@ package cli
 
 import (
 	"os"
+	"io/fs"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -28,8 +29,8 @@ func TestGenMan(t *testing.T) {
 
 	// Ensure we have a sane number of man pages.
 	count := 0
-	err := filepath.Walk(manpath, func(path string, info os.FileInfo, err error) error {
-		if strings.HasSuffix(path, ".1") && !info.IsDir() {
+	err := filepath.WalkDir(manpath, func(path string, d fs.DirEntry, err error) error {
+		if strings.HasSuffix(path, ".1") && !d.IsDir() {
 			count++
 		}
 		return nil

pkg/cli/userfiletable_test.go

@@ -10,6 +10,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"io/fs"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -446,12 +447,12 @@ func TestUserFileUploadRecursive(t *testing.T) {
 					dstDir = tc.destination + "/" + filepath.Base(testDir)
 				}
 
-				err = filepath.Walk(testDir,
-					func(path string, info os.FileInfo, err error) error {
+				err = filepath.WalkDir(testDir,
+					func(path string, d fs.DirEntry, err error) error {
 						if err != nil {
 							return err
 						}
-						if info.IsDir() {
+						if d.IsDir() {
 							return nil
 						}
 						relPath := strings.TrimPrefix(path, testDir+"/")

pkg/cmd/dev/io/os/os.go

@@ -459,10 +459,10 @@ func (o *OS) ListFilesWithSuffix(root, suffix string) ([]string, error) {
 
 	output, err := o.Next(command, func() (output string, err error) {
 		var ret []string
-		if err := filepath.Walk(root, func(path string, info fs.FileInfo, err error) error {
+		if err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
 			// If there's an error walking the tree, throw it away -- there's
 			// nothing interesting we can do with it.
-			if err != nil || info.IsDir() {
+			if err != nil || d.IsDir() {
 				//nolint:returnerrcheck
 				return nil
 			}

pkg/cmd/roachtest/cluster.go

@@ -2333,11 +2333,11 @@ func (c *clusterImpl) RefetchCertsFromNode(ctx context.Context, node int) error
 		return errors.Wrap(err, "cluster.StartE")
 	}
 	// Need to prevent world readable files or lib/pq will complain.
-	return filepath.Walk(c.localCertsDir, func(path string, info fs.FileInfo, err error) error {
+	return filepath.WalkDir(c.localCertsDir, func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
 			return errors.Wrap(err, "walking localCertsDir failed")
 		}
-		if info.IsDir() {
+		if d.IsDir() {
 			return nil
 		}
 		return os.Chmod(path, 0600)

pkg/cmd/roachtest/tests/network.go

@@ -8,6 +8,7 @@ package tests
 import (
 	"context"
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -87,7 +88,7 @@ func runNetworkAuthentication(ctx context.Context, t test.Test, c cluster.Cluste
 	require.NoError(t, err)
 	require.NoError(t, os.RemoveAll(localCertsDir))
 	require.NoError(t, c.Get(ctx, t.L(), certsDir, localCertsDir, c.Node(1)))
-	require.NoError(t, filepath.Walk(localCertsDir, func(path string, info os.FileInfo, err error) error {
+	require.NoError(t, filepath.WalkDir(localCertsDir, func(path string, d fs.DirEntry, err error) error {
 		// Don't change permissions for the certs directory.
 		if path == localCertsDir {
 			return nil

pkg/cmd/roachtest/zip_util_test.go

@@ -8,6 +8,7 @@ package main
 import (
 	"archive/zip"
 	"os"
+	"io/fs"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -31,9 +32,9 @@ func TestMoveToZipArchive(t *testing.T) {
 	expectLs := func(expected ...string) {
 		t.Helper()
 		var actual []string
-		require.NoError(t, filepath.Walk(baseDir, func(path string, info os.FileInfo, err error) error {
+		require.NoError(t, filepath.WalkDir(baseDir, func(path string, d fs.DirEntry, err error) error {
 			require.NoError(t, err)
-			if !info.IsDir() {
+			if !d.IsDir() {
 				rel, err := filepath.Rel(baseDir, path)
 				require.NoError(t, err)
 				actual = append(actual, rel)

pkg/cmd/whoownsit/whoownsit.go

@@ -13,6 +13,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -41,11 +42,11 @@ func main() {
 				os.Exit(1)
 			}
 		}
-		if err := filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
+		if err := filepath.WalkDir(path, func(path string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
-			if !*dirsOnly || info.IsDir() {
+			if !*dirsOnly || d.IsDir() {
 				matches := codeOwners.Match(path)
 				var aliases []string
 				for _, match := range matches {

pkg/internal/codeowners/lint.go

@@ -7,7 +7,7 @@ package codeowners
 
 import (
 	"fmt"
-	"os"
+	"io/fs"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -72,14 +72,14 @@ func LintEverythingIsOwned(
 
 	walkRoot := filepath.Join(repoRoot, walkDir)
 
-	unownedWalkFn := func(path string, info os.FileInfo) error {
+	unownedWalkFn := func(path string, d fs.DirEntry) error {
 		teams := co.Match(path)
 		if len(teams) > 0 {
 			// The file has an owner, so nothing to report.
 			debug("%s <- has team(s) %v", path, teams)
 			return nil
 		}
-		if !info.IsDir() {
+		if !d.IsDir() {
 			// We're looking at a file that has no owner.
 			//
 			// Let's say `path = ./pkg/foo/bar/baz.go`.
@@ -113,7 +113,7 @@ func LintEverythingIsOwned(
 	for len(dirsToWalk) != 0 {
 		// We first visit each directory's files, and then the subdirectories.
 		// See TestLintEverythingIsOwned for details.
-		require.NoError(t, filepath.Walk(dirsToWalk[0], func(path string, info os.FileInfo, err error) error {
+		require.NoError(t, filepath.WalkDir(dirsToWalk[0], func(path string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
@@ -132,7 +132,7 @@ func LintEverythingIsOwned(
 
 				if _, ok := skip[relPath]; ok {
 					debug("skipping %s", relPath)
-					if info.IsDir() {
+					if d.IsDir() {
 						return filepath.SkipDir
 					}
 					return nil
@@ -144,7 +144,7 @@ func LintEverythingIsOwned(
 					}
 					if ok {
 						debug("skipping %s", relPath)
-						if info.IsDir() {
+						if d.IsDir() {
 							return filepath.SkipDir
 						}
 						return nil
@@ -153,21 +153,21 @@ func LintEverythingIsOwned(
 				fname := filepath.Base(relPath)
 				if _, ok := skip[fname]; ok {
 					debug("skipping %s", relPath)
-					if info.IsDir() {
+					if d.IsDir() {
 						return filepath.SkipDir
 					}
 					return nil
 				}
 			}
 
-			if info.IsDir() {
+			if d.IsDir() {
 				if path == dirsToWalk[0] {
 					return nil
 				}
 				dirsToWalk = append(dirsToWalk, path)
 				return filepath.SkipDir
 			}
-			return unownedWalkFn(filepath.Join(walkDir, relPath), info)
+			return unownedWalkFn(filepath.Join(walkDir, relPath), d)
 		}))
 		dirsToWalk = dirsToWalk[1:]
 	}

pkg/storage/pebble_iterator_test.go

@@ -49,11 +49,11 @@ func TestPebbleIterator_Corruption(t *testing.T) {
 	require.NoError(t, p.Flush())
 
 	// Corrupt the SSTs in the DB.
-	err = filepath.Walk(dataDir, func(path string, info stdfs.FileInfo, err error) error {
+	err = filepath.WalkDir(dataDir, func(path string, d stdfs.DirEntry, err error) error {
 		if err != nil {
 			return err
 		}
-		if !strings.HasSuffix(info.Name(), ".sst") {
+		if !strings.HasSuffix(d.Name(), ".sst") {
 			return nil
 		}
 		file, err := os.OpenFile(path, os.O_WRONLY, 0600)