Re: [RFC PATCHv5 0/6] zram: introduce writeback bio batching

[Gao Xiang]

On 2025/11/23 08:08, Sergey Senozhatsky wrote:
> On (25/11/22 22:09), Gao Xiang wrote:
> > > I thought you were talking about the backing device being
> > > ext4/btrfs.  Sorry, I don't have enough context/knowledge
> > > to understand what you're getting at.  zram has been doing
> > > writeback for ages, I really don't know what you mean by
> > > "to act like this".
> >
> > I mean, if zram is formatted as ext4, and then mount it;
> > and then there is a backing file which is also in another
> > ext4, you'd need a workqueue to do writeback I/Os (or needs
> > a loop device to transit), was that the original question
> > raised by Yuwen?
>
> We take pages of data from zram0 and write them straight to
> the backing device.  Those writes don't go through vfs/fs so
> fs on the backing device will simply be corrupted, as far as
> I can tell.  This is not intendant use case for zram writeback.

I'm pretty sure you don't understand what I meant.

I won't reply this anymore, good luck.

Thanks,
Gao Xiang