vfs_crossrename not working in samba-4.15.*

[Jeremy Allison]

On Fri, Oct 07, 2022 at 04:25:19PM +0200, Pavel Filipenský via samba-technical wrote:
>I believe that the bug was introduced in
>
>5c18f07 2021-06-16 21:01 -0700 Jeremy Allison     o s3: VFS: 
>crossrename. Use real dirfsp for SMB_VFS_RENAMEAT()
>
>
>which removes
>
>-       if (unlink (dest) && errno != ENOENT) {
>
>and adss
>
>
>+       ret = SMB_VFS_NEXT_UNLINKAT(handle,..
>+       if (ret == -1) {

Well calling "unlink()" directly is (a) symlink-unsafe,
and (b) means this module is completely unstackable
and not usable on anything other than a local filesystem.

So I stand by the change :-). We just need to figure
out the locking issues.