[cifs-protocol] 119101121001349 MS-SMB2: File.LastModificationTime updates for write IO vs setinfo

[Ralph Boehme]

Am 11/5/19 um 5:22 PM schrieb Sreekanth Nadendla:
> Hello Ralph,
> The differences in LastModificationTime observed by you between Server 2016 and Server 2019 can be explained as follows:
> 
> Up to Server 2016, when a read (write) occurred, NTFS would simply set a flag on the handle saying that a read (write) occurred during the handle's lifetime.  At handle close time, if the read (write) flag was set on the handle, then NTFS would set the LastAccessTime (LastModificationTime) for the file to the time of handle close.

ok, makes sense.


> Starting with Server 2019, when a read (write) occurs, NTFS sets the LastAccessTime (LastModificationTime) for the file immediately at the time of the read (write).
> Note we only made this change in NTFS, not other file systems. There are practical considerations such as performance, memory footprint, etc. that are driving these decisions.

Ok.

> We will update our specs formally in the coming days.

Looks like no update has been published yet. Can you ping me when the
updated docs are available? Or can you share the the updated text excerpt?

Thanks!
-slow

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Ralph Boehme, Samba Team                https://samba.org/
Samba Developer, SerNet GmbH   https://sernet.de/en/samba/
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