status of bugzilla #99171 - mdraid broken for O_DIRECT

[Roland <devzero@web.de>]

Hello,

as proxmox hypervisor does not offer mdadm software raid at installation
time because of this bugticket

"MD RAID or DRBD can be broken from userspace when using O_DIRECT"
https://bugzilla.kernel.org/show_bug.cgi?id=99171

i tried to find some more references besides the kernel bugzilla entry -
and  - besides some discussion in the proxmox community - i did not succeed.

why is this apparent fundamental design flaw (should we call it that?)
so damn unknown ?

and what about O_DIRECT with other software raid solutions like btrfs or
zfs ?

how/why do they right but not mdraid ?  the latter exists for much
longer time and afaik is offered as install-time option for RHEL
(enterprise linux) for example, where people use oracle on top - which
IS using O_DIRECT very often/likely.

not accusing anyone - just being curious why totally unknown/unpopular
bugticket #99171 bitrots for nearly a decade now...

regards
Roland

Sysadmin

ps:
also see "qemu cache=none should not be used with mdadm"
https://bugzilla.proxmox.com/show_bug.cgi?id=5235