linux-kernel - Re: [PATCH RFC v2 0/2] fuse: compound commands

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Message-ID: <f3418925-6e3a-4593-b6c4-4ac7ad4d6740@bsbernd.com>
Date: Mon, 29 Dec 2025 13:27:26 +0100
From: Bernd Schubert <bernd@...ernd.com>
To: Jingbo Xu <jefflexu@...ux.alibaba.com>,
 Horst Birthelmer <hbirthelmer@...glemail.com>,
 Miklos Szeredi <miklos@...redi.hu>, Joanne Koong <joannelkoong@...il.com>
Cc: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
 Horst Birthelmer <hbirthelmer@....com>, syzbot@...kaller.appspotmail.com
Subject: Re: [PATCH RFC v2 0/2] fuse: compound commands

On 12/29/25 07:03, Jingbo Xu wrote:
> Hi Horst & Bernd,
> 
> On 12/24/25 6:13 AM, Horst Birthelmer wrote:
>> In the discussion about open+getattr here [1] Bernd and Miklos talked
>> about the need for a compound command in fuse that could send multiple
>> commands to a fuse server.
>>     
>> Here's a propsal for exactly that compound command with an example
>> (the mentioned open+getattr).
>>     
>> [1] https://lore.kernel.org/linux-fsdevel/CAJfpegshcrjXJ0USZ8RRdBy=e0MxmBTJSCE0xnxG8LXgXy-xuQ@mail.gmail.com/
>>
> 
> To achieve close-to-open, why not just invalidate the cached attr on
> open so that the following access to the attr would trigger a new
> FUSE_GETATTR request to fetch the latest attr from server?
> 
> 

Hi Jingbo,

because that slows down operation. Doing in 1 step is faster.

https://lore.kernel.org/r/20240820211735.2098951-1-bschubert@ddn.com

https://lore.kernel.org/all/20240813212149.1909627-1-joannelkoong@gmail.com/


Initially Joanne had created the 1st patch and I had asked to do that in
one step and created open+getattr v2 with a new op code. Miklos then
objected and asked for a compound version to avoid too many new op
codes. Horst is in the mean time also working on atomic open using
compounds and I have another use case for attribute updates on writes.
I.e. this is the 3rd attempt.


Thanks,
Bernd