Re: [PATCH v2] vfs: prevent copy_file_range to copy across devices

[Luis Henriques]

Amir Goldstein <amir73il@xxxxxxxxx> writes:

> On Thu, Feb 18, 2021 at 9:42 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>>
>> Looks good:
>>
>> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
>>
>> This whole idea of cross-device copie has always been a horrible idea,
>> and I've been arguing against it since the patches were posted.
>
> Ok. I'm good with this v2 as well, but need to add the fallback to
> do_splice_direct()
> in nfsd_copy_file_range(), because this patch breaks it.
>
> And the commit message of v3 is better in describing the reported issue.

Except that, as I said in a previous email, v2 doesn't really fix the
issue: all the checks need to be done earlier in generic_copy_file_checks().

I'll work on getting v4, based on v2 and but moving the checks and
implementing your review suggestions to v3 (plus this nfs change).

Cheers,
-- 
Luis