[pve-devel] [[PATCH kernel]] fix 5683: netfs: reset subreq iov iter before tail clean

[Christian Ebner]

On 10/23/24 10:28, Thomas Lamprecht wrote:
> Am 22/10/2024 um 17:46 schrieb Christian Ebner:
>> I refrained from doing so as I saw that typically fixes to mainline are
>> back-ported to stable, but since this is already fixed in the latest
>> version, I was hoping for upstream guidance on how to proceed
>> (unfortunately without reply).
> 
> Hmm, true, this makes it a bit more complicated.
> If you submit it then to stable and the maintainers should definitively should
> add the context for why a 1:1 cherry-pick is not an option, like it being rather
> huge and the fixing the misalignment as side effect of correcting the tracking
> of subreq->transferred where sensible before calling into the new
> netfs_read_subreq_terminated helper that replaced the netfs_subreq_terminated
> one you're adapting here, at least FWICT.

Yeah, I will definitely include more detailed reasoning and the context 
on why this applies to stable only.
Unfortunately I do not have my reproducer cluster with me this week, so 
I would do this first thing on Monday next week. I do wanted to double 
check and test with current stable, also hopefully gaining some more 
insides with your and Fiona's feedback.

> So FWIW, while I also would prefer some comment from upstream, I'm also fine
> with applying this now, as it seems reasonable workaround and letting the kernel
> through to the test repo to allow those affected to test it would also to get us
> some more QA out of this patch before moving it to more stable repos.

That would be great, at least to see if this really also fixes the 
issues customers see with the fixed index files being corrupted on their 
CephFS located datastores, e.g. [0]. Since I never reproduced that exact 
issue (I only reproduced the corrupt checksum after file upload [1]), 
confirmation that this is fixed would be a big plus.

[0] https://forum.proxmox.com/threads/149249/
[1] https://forum.proxmox.com/threads/151291/