linux-kernel - Re: [PATCH V3 1/1] ublk: add io_uring based userspace block driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87a69oamap.fsf@collabora.com>
Date:   Mon, 04 Jul 2022 12:13:18 -0400
From:   Gabriel Krisman Bertazi <krisman@...labora.com>
To:     Sagi Grimberg <sagi@...mberg.me>
Cc:     Ming Lei <ming.lei@...hat.com>, Jens Axboe <axboe@...nel.dk>,
        linux-block@...r.kernel.org,
        Harris James R <james.r.harris@...el.com>,
        linux-kernel@...r.kernel.org, io-uring@...r.kernel.org,
        ZiyangZhang <ZiyangZhang@...ux.alibaba.com>,
        Xiaoguang Wang <xiaoguang.wang@...ux.alibaba.com>,
        Stefan Hajnoczi <stefanha@...hat.com>
Subject: Re: [PATCH V3 1/1] ublk: add io_uring based userspace block driver

Sagi Grimberg <sagi@...mberg.me> writes:

>>>> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
>>>> index fdb81f2794cd..d218089cdbec 100644
>>>> --- a/drivers/block/Kconfig
>>>> +++ b/drivers/block/Kconfig
>>>> @@ -408,6 +408,12 @@ config BLK_DEV_RBD
>>>>    	  If unsure, say N.
>>>> +config BLK_DEV_UBLK
>>>> +	bool "Userspace block driver"
>>>
>>> Really? why compile this to the kernel and not tristate as loadable
>>> module?
>> So far, this is only one reason: task_work_add() is required, which
>> isn't exported for modules.
>
> So why not exporting it?
> Doesn't seem like a good justification to build it into the kernel.

Sagi,

If I understand correctly, the task_work_add function is quite a core
API that we probably want to avoid exposing directly to (out-of-tree)
modules?  I agree, though, it would be great to have this buildable as a
module for general use cases.  Would it make sense to have it exposed
through a thin built-in wrapper, specific to UBD, which is exported, and
therefore able to invoke that function?  Is it a reasonable approach?

-- 
Gabriel Krisman Bertazi