Subject: Re: linux-next: manual merge of the block tree with the tree

From: Kent Overstreet <[email-masked]>
Date: Thu, 7 Nov 2013 23:56:17 -0800

On Thu, Nov 07, 2013 at 11:44:45PM -0800, Christoph Hellwig wrote:
> On Thu, Nov 07, 2013 at 11:39:59PM -0800, Kent Overstreet wrote:
> > On Thu, Nov 07, 2013 at 11:33:24PM -0800, Christoph Hellwig wrote:
> > > The changes for direct I/O from kernel space have been in for a long
> > > time, and they are blocking multiple consumers of the interface from
> > > getting submitted for about a year now.  Even if the guts of the
> > > direct-io code will get a write based on another patchset from Kent
> > > that will go on top of the immutable iovec changes we need the
> > > interfaces now and not another year down the road.
> > 
> > What else is blocked on this patch series? Honest question.
> 
> 
> From me alone:
>   Support for ecryptfs to not double cache.
>   AIO support for target_core_file.
> 
> To replace code in staging:
>   Removal of the lustre-specific loop driver.
> 
> And I remember others claiming to want to submit bits, too.

So, I don't think the iov_iter stuff is the right approach for solving
the loop issue; it's an ugly hack and after immutable biovecs we're
pretty close to a better solution and some major cleanups too.

I don't know about ecryptfs and AIO for target, though - are there
patches for those you could point me at so I can have a look? I can
believe the iov_iter stuff is necessary for those, but I'd like to
convince myself there isn't a cleaner solution.

Regardless, I don't want to be blocking anyone else's work; if we do
want the iov_iter stuff in now (I'm not arguing one way or the other
till I look at the issues you pointed out) I can write a small patch to
correctly merge with immutable bvecs; I looked at it today and it's
pretty straightforward (if somewhat ugly).