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

[Jeff McCashland]

Hi Ralph,

Presumably the change would be to add READ_CONTROL to the list in the section you referenced. I'll let you know when and if the document is updated. 

However, note that legacy Oplocks do break on READ_CONTROL. If I understand our source code correctly, Leases never broke on READ_CONTROL, but we didn't catch the variance in the doc. 

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 Böhme <slow at samba.org> 
Sent: Tuesday, March 3, 2020 12:42 PM
To: Jeff McCashland <jeffm at microsoft.com>
Cc: cifs-protocol at lists.samba.org; support <support at mail.support.microsoft.com>
Subject: [EXTERNAL] Re: [REG:120030321000983] SMB2: opening file for READ_CONTROL doesn't trigger lease break

Hi Jeff,

thanks for looking into this!

Can you share what the update will be? What is the expected behaviour?

Thanks!
-slow

> Am 03.03.2020 um 21:16 schrieb Jeff McCashland <jeffm at microsoft.com>:
> 
> Hi slow,
> 
> I love the trace you sent, it's beautiful. I've verified that Frame 139 unexpectedly does not break lease. 
> 
> I thought it was interesting that READ_EA access also breaks the lease, but I'm not certain why. 
> 
> Thank you for pointing this out and providing the trace. I will file a request to update the doc.
> 
> 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: 
> https://nam06.safelinks.protection.outlook.com/?url=http%3A%2F%2Fsuppo
> rt.microsoft.com%2Fglobalenglish&data=02%7C01%7Cjeffm%40microsoft.
> com%7C4e4eee108d37458be38408d7bfb35d47%7C72f988bf86f141af91ab2d7cd011d
> b47%7C1%7C0%7C637188649402437847&sdata=VMVfPSpMMeDAbidsEQR3jPgvQCT
> JAsz%2BU%2BRrSfMP6UE%3D&reserved=0 | Extension 1138300 We value 
> your feedback.  My manager is Jeremy Chapman (jeremyc), +1 (469) 
> 775-2475
> 
> -----Original Message-----
> From: Jeff McCashland <jeffm at microsoft.com>
> Sent: Tuesday, March 3, 2020 6:33 AM
> To: Ralph Boehme <slow at samba.org>
> Cc: cifs-protocol at lists.samba.org; support 
> <support at mail.support.microsoft.com>
> Subject: [REG:120030321000983] SMB2: opening file for READ_CONTROL 
> doesn't trigger lease break
> 
> [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: 
> https://nam06.safelinks.protection.outlook.com/?url=http%3A%2F%2Fsuppo
> rt.microsoft.com%2Fglobalenglish&data=02%7C01%7Cjeffm%40microsoft.
> com%7C4e4eee108d37458be38408d7bfb35d47%7C72f988bf86f141af91ab2d7cd011d
> b47%7C1%7C0%7C637188649402437847&sdata=VMVfPSpMMeDAbidsEQR3jPgvQCT
> JAsz%2BU%2BRrSfMP6UE%3D&reserved=0 | 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 2.1.4.12 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  
> FILE_READ_ATTRIBUTES, FILE_WRITE_ATTRIBUTES, or SYNCHRONIZE  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?
> 
> Thanks!
> -slow
> 
> --
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