From fd09b7d3b352105f08b8e02f7afecf7e816380ef Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Thu, 2 Aug 2018 20:28:18 -0500
Subject: [PATCH] smb3: Do not send SMB3 SET_INFO if nothing changed
Git-commit: fd09b7d3b352105f08b8e02f7afecf7e816380ef
Patch-mainline: v4.19-rc1
References: bsc#1051510, bsc#1144333

An earlier commit had a typo which prevented the
optimization from working:

commit 18dd8e1a65dd ("Do not send SMB3 SET_INFO request if nothing is changing")

Thank you to Metze for noticing this.  Also clear a
reserved field in the FILE_BASIC_INFO struct we send
that should be zero (all the other fields in that
struct were set or cleared explicitly already in
cifs_set_file_info).

Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> # 4.9.x+
Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/inode.c     | 2 ++
 fs/cifs/smb2inode.c | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 054e880c1dac..d32eaa4b2437 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1120,6 +1120,8 @@ cifs_set_file_info(struct inode *inode, struct iattr *attrs, unsigned int xid,
 	if (!server->ops->set_file_info)
 		return -ENOSYS;
 
+	info_buf.Pad = 0;
+
 	if (attrs->ia_valid & ATTR_ATIME) {
 		set_time = true;
 		info_buf.LastAccessTime =
diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index f22cbc0d1869..1eef1791d0c4 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -283,7 +283,7 @@ smb2_set_file_info(struct inode *inode, const char *full_path,
 	int rc;
 
 	if ((buf->CreationTime == 0) && (buf->LastAccessTime == 0) &&
-	    (buf->LastWriteTime == 0) && (buf->ChangeTime) &&
+	    (buf->LastWriteTime == 0) && (buf->ChangeTime == 0) &&
 	    (buf->Attributes == 0))
 		return 0; /* would be a no op, no sense sending this */
 
-- 
2.16.4