From 17c58f5fcef9e75a2880e41bb0e994af1370e836 Mon Sep 17 00:00:00 2001
From: Sujal Shah <sujalshah28092004@gmail.com>
Date: Tue, 5 Aug 2025 22:40:26 +0530
Subject: [PATCH] wal: ignore os.ErrNotExist errors in DirSize during WAL size
 calculation

This change updates `DirSize` to ignore `os.ErrNotExist` errors,
since they are expected during normal WAL cleanup. All other errors
continue to propagate.

Fixes: #17005
Signed-off-by: Sujal Shah <sujalshah28092004@gmail.com>
---
 tsdb/fileutil/dir.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tsdb/fileutil/dir.go b/tsdb/fileutil/dir.go
index 1672a92d4c..ad039d2231 100644
--- a/tsdb/fileutil/dir.go
+++ b/tsdb/fileutil/dir.go
@@ -22,6 +22,10 @@ func DirSize(dir string) (int64, error) {
 	var size int64
 	err := filepath.Walk(dir, func(_ string, info os.FileInfo, err error) error {
 		if err != nil {
+			// Ignore missing files that may have been deleted during the walk.
+			if os.IsNotExist(err) {
+				return nil
+			}
 			return err
 		}
 		if !info.IsDir() {