This bz is being created for a patch I requested for merge at
https://gitlab.com/samba-team/samba/-/merge_requests/1826

Copying over the summary:

Commit - 405d1164 smbd: open a pathref fsp on the parent directory

adds a TALLOC_FREE() call which clears out the errno required by the subsequent map_nt_error_from_unix() call. The errno is possibly cleared by a destructor called by the TALLOC_FREE(). This results in an incorrect nt_status being returned.

This is causing failures in smb2.create.mkdir-dup with glusterfs as the backing fs.

Fix this by calling map_nt_error_from_unix(errno) before the TALLOC_FREE() call is made.

I have tested this patch using smbtorture smb2.create.mkdir-dup test with glusterfs as the backend filesystem for both replicate and disperse volumes.