From 9a00c17555e00e6c3b05c93add9042a3293cfb19 Mon Sep 17 00:00:00 2001
From: chrislu <chris.lu@gmail.com>
Date: Tue, 28 Dec 2021 16:30:33 -0800
Subject: [PATCH] reader: avoid wrong pattern detection due to lock waiting

---
 weed/filer/reader_at.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/weed/filer/reader_at.go b/weed/filer/reader_at.go
index b73526761..670de382c 100644
--- a/weed/filer/reader_at.go
+++ b/weed/filer/reader_at.go
@@ -105,11 +105,11 @@ func (c *ChunkReadAt) Close() error {
 
 func (c *ChunkReadAt) ReadAt(p []byte, offset int64) (n int, err error) {
 
+	c.readerPattern.MonitorReadAt(offset, len(p))
+
 	c.readerLock.Lock()
 	defer c.readerLock.Unlock()
 
-	c.readerPattern.MonitorReadAt(offset, len(p))
-
 	// glog.V(4).Infof("ReadAt [%d,%d) of total file size %d bytes %d chunk views", offset, offset+int64(len(p)), c.fileSize, len(c.chunkViews))
 	return c.doReadAt(p, offset)
 }