releases/4.9.231/cifs-update-ctime-and-mtime-during-truncate.patch

From b8d41ab8b1a2823293543a075345460b38aca61d Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Fri, 19 Jun 2020 22:51:29 -0400
Subject: cifs: update ctime and mtime during truncate

From: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>

[ Upstream commit 5618303d8516f8ac5ecfe53ee8e8bc9a40eaf066 ]

As the man description of the truncate, if the size changed,
then the st_ctime and st_mtime fields should be updated. But
in cifs, we doesn't do it.

It lead the xfstests generic/313 failed.

So, add the ATTR_MTIME|ATTR_CTIME flags on attrs when change
the file size

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/inode.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 3dad943da956f..acd8e0dccab4c 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2194,6 +2194,15 @@ set_size_out:
 	if (rc == 0) {
 		cifsInode->server_eof = attrs->ia_size;
 		cifs_setsize(inode, attrs->ia_size);
+
+		/*
+		 * The man page of truncate says if the size changed,
+		 * then the st_ctime and st_mtime fields for the file
+		 * are updated.
+		 */
+		attrs->ia_ctime = attrs->ia_mtime = current_time(inode);
+		attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME;
+
 		cifs_truncate_page(inode->i_mapping, inode->i_size);
 	}
 
-- 
2.25.1