[Samba] Odd "File exists" behavior when copy-pasting many files to an SMB exported Lustre FS

[Jeremy Allison]

On Mon, Apr 04, 2022 at 03:26:03PM -0700, Christian Kuntz via samba wrote:
>Hi all,
>
>Resident wild-guy Christian here. In summary, I'm seeing an odd problem
>from both Windows Explorer and Mac Finder when copy-pasting a large batch
>of files to a Lustre-backed SMB share wherein the file manager appears to
>enumerate over all the files to determine if they can be made in the
>destination, makes 0-byte stubs of each file, and then proudly states that
>the files already exist in the destination. This behavior is
>less-than-desirable and I was hoping someone else here had run into it, or
>someone better than I at diagnosing SMB weirdness could give me a hand
>debugging. I'm inclined to think it's a Lustre idiosyncracy, since this
>does not occur on a ZFS share.

If it doesn't happen on a ZFS share, but does on a Lustre one then
it's certainly a Lustre oddity. Try looking at debug logs to figure
out what Lustre is doing that smbd doesn't like.