[cifs-protocol] [REG:120030321000983] SMB2: opening file for READ_CONTROL doesn't trigger lease break

Jeff McCashland jeffm at microsoft.com
Tue Mar 3 14:32:52 UTC 2020

[DocHelp to BCC, support on CC, SR ID on Subject]

Hi slow,

Thank you for sending in your question and trace. We have created SR 120030321000983 to track this issue. I will review your trace and follow up.

Best regards,
Jeff McCashland | Senior Escalation Engineer | Microsoft Protocol Open Specifications Team 
Phone: +1 (425) 703-8300 x38300 | Hours: 9am-5pm | Time zone: (UTC-08:00) Pacific Time (US and Canada)
Local country phone number found here: http://support.microsoft.com/globalenglish | Extension 1138300
We value your feedback.  My manager is Jeremy Chapman (jeremyc), +1 (469) 775-2475

-----Original Message-----
From: Ralph Boehme <slow at samba.org> 
Sent: Tuesday, March 3, 2020 2:57 AM
To: Interoperability Documentation Help <dochelp at microsoft.com>
Cc: cifs-protocol at lists.samba.org
Subject: [EXTERNAL] SMB2: opening file for READ_CONTROL doesn't trigger lease break

Hello dochelp,

according to MS-FSA opening a file with at most FILE_READ_ATTRIBUTES, FILE_WRITE_ATTRIBUTES, or SYNCHRONIZE avoids triggering an oplock break:

  If OpParams.DesiredAccess contains no flags other than
  the algorithm returns at this point.

However, testing all valid file access bits individually against a Windows 2016 server reveals that an access mask of READ_CONTROL also doesn't trigger an oplock break.

Attached is a network trace of a testcase that tests all possible file access masks.

The testcase with READ_CONTROL begins in packet 137 (request open with RWH lease), the open with READ_CONTROL is in packet 139.

Can you clarify?


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