Re: [PATCH v5 00/10] ceph: convert writeback path to folios

[Tal Zussman]

H

On 10/8/26 12:00 PM, David Howells wrote:
> Hi Tal,
> 
> Apologies for not reaching out to you before, but I keep getting diverted on
> to other thing - usually by AI patch reviews.
> 
> Just to note that I have patches in the works to convert ceph to use netfslib
> and thus strip out all the dealing with pages/folios as much as possible -
> even getting down into the protocol and replacing the five different page
> carrying types with the same structure as is at the core of netfslib (bvecq
> chains) and pass the bvecq chains all the way into sendmsg() for transmission.
> 
> This also lets me remove ceph's use of the PG_private_2 flag which the MM
> people would really like back.  That's then replaced - transparently inside of
> netfslib - by setting a special ->private value on folios read from the
> server, marking them dirty and then having writeback write them to the cache.
> 
> It's unfortunately stalled on getting some netfslib changes in, though there
> may be hope for making some progress in this merge window.
> 
> If you go to my tree here:
> 
> 	https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/
> 
> The netfs-next[12345] branches are the prerequisite patches I'm trying to get
> in at the moment, divided into five batches.
> 
> On top of that is my netfs-crypt branch that has content crypto support
> 
> And then on top of that is my ceph-iter branch.  Note that it's not fully
> working as yet and I'm still testing and fixing bits of it.
> 

That's great, I see it removes the ceph pagelist and with it the last couple
callers of __page_cache_alloc(). I wasn't planning on sending additional ceph
patches in the near future, as they would all require getting into the
protocol, so it's great to hear you're working on this!

> If you want to push these patches first, I can always adapt my patches to take
> account of them.
> 

It'd be great to get this series in sooner rather than later. I think it's
ready to be merged and it would let us remove five page wrappers of folio
functions immediately. Hopefully since it's fairly small it won't cause you
too much trouble.

Thanks,
Tal