Does the CreateDisposition flag of a client depend on Server's response ?

[varun mittal]

Nothing fancy, simple copy command:
robocopy C:\Users\mittal\Downloads Y:\Shared\Folder1\Subfolder <file-name>
/COPY:DAT /R:1 /W:10

On Sat, Feb 4, 2023, 8:05 AM Tom Talpey <tom at talpey.com> wrote:

> On 2/3/2023 12:50 PM, Jeremy Allison via samba-technical wrote:
> > On Fri, Feb 03, 2023 at 08:51:57PM +0530, varun mittal wrote:
> >>   I was able to narrow it down to the "Named Streams" bit in
> >>   "FileFSAttributeInformation" response.
> >>   When this value is toggled from 0 to 1, as is advertised by
> >>   `streams_xattr` VFS module, Robocopy
> >>   switched from FILE_OPEN to FILE_OPEN_IF.
> >>   Thanks
> >
> > Thanks for tracking that down. What strange behavior.
> > I can't see why having a stream would make the open
> > change to optionally creating the file, but it's good
> > info to know. Thanks for posting the follow-up to
> > the list !
>
> It's not the presence af a stream, it's that the fileystem supports
> named streams. It's getting that from a FileFsAttributeInformation
> on the root directory.
>
> Robocopy has a very broad range of OS- and FS-dependent behaviors
> and optimizations. I bet there's some combination of its 1000-odd
> commandline options that can change this.
>
> Varun, what exact robocopy command are you seeing this from?
>
> Tom.
>