smb3: Do not send SMB3 SET_INFO if nothing changed

commit fd09b7d3b352105f08b8e02f7afecf7e816380ef upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 0c7b7e2a0919a9a8c219543f5febe79c9dd6195b..caf9cf91b825a85aac13fc37684ae9181d1f94bb 100644 (file)
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1122,6 +1122,8 @@ 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 1238cd3552f9cc8e8f8fc560117af37cd224aa13..0267d8cbc9966cd7e2327ee98f014344ce5d7c0c 100644 (file)
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -267,7 +267,7 @@ 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 */