Lightning: Skip apply ioworkers when seek(0, io.SeekCurrent) (#57454) (…

…#59544) close #57413
pingcap · Feb 17, 2025 · 017dd17 · 017dd17
1 parent 19843ce
commit 017dd17
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/br/pkg/lightning/mydump/reader.go b/br/pkg/lightning/mydump/reader.go
@@ -170,8 +170,11 @@ func (pr PooledReader) Read(p []byte) (n int, err error) {
 
 // Seek implements io.Seeker
 func (pr PooledReader) Seek(offset int64, whence int) (int64, error) {
-	w := pr.ioWorkers.Apply()
-	defer pr.ioWorkers.Recycle(w)
+	// Seek(0, io.SeekCurrent) is used to get the current offset, which will not cause any Disk I/O.
+	if pr.ioWorkers != nil && !(offset == 0 && whence == io.SeekCurrent) {
+		w := pr.ioWorkers.Apply()
+		defer pr.ioWorkers.Recycle(w)
+	}
 	return pr.reader.Seek(offset, whence)
 }