From 89a79b03cfcdd07a11b799fd4612e57d35d659f7 Mon Sep 17 00:00:00 2001
From: SPRESENSE <41312067+SPRESENSE@users.noreply.github.com>
Date: Wed, 22 Jul 2020 14:41:40 +0900
Subject: [PATCH] fs/smartfs: Fix file size corruption when opening with
 overwriting mode

If a existing file is opened with overwriting mode e.g. fopen(file, "w+"),
the file size will be incorrect after writing any data to the file.
This bug is caused by previous commit 10903b5, and its changes should be
limited to only O_APPEND mode.
---
 fs/smartfs/smartfs_smart.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/smartfs/smartfs_smart.c b/fs/smartfs/smartfs_smart.c
index 60c591babb..dca3b8b9d5 100644
--- a/fs/smartfs/smartfs_smart.c
+++ b/fs/smartfs/smartfs_smart.c
@@ -331,10 +331,11 @@ static int smartfs_open(FAR struct file *filep, const char *relpath,
 
   /* When using sector buffering, current sector with its header should
    * always be present in sf->buffer. Otherwise data corruption may arise
-   * when writing.
+   * when writing. However, this does not apply when overwriting without
+   * append mode.
    */
 
-  if (sf->currsector != SMARTFS_ERASEDSTATE_16BIT)
+  if ((sf->currsector != SMARTFS_ERASEDSTATE_16BIT) && (oflags & O_APPEND))
     {
       readwrite.logsector = sf->currsector;
       readwrite.offset    = 0;