Re: [PATCHv5 3/3] dm-crypt: allow unaligned bio_vecs for direct io

[Keith Busch <kbusch@kernel.org>]

On Sat, Jul 11, 2026 at 12:30:18AM -0400, Eric Biggers wrote:
> On Fri, Jul 10, 2026 at 10:14:19PM -0600, Keith Busch wrote:
> 
> I don't think patch 2 is sufficient, as BLK_STS_RESOURCE is often not
> going to get handled correctly.

In practice, I could only get the memory allocation failure to happen in
interrupt context due to the GFP_ATOMIC use, and that appears to be
handled correctly. If I synthesize memory failure in the process
context, then that is getting sent back to the application, so I assume
that's what you mean about BLK_STS_RESOURCE not always handled
correctly. I'll get that fixed up.
 
> > > I think you'll need to take the limitations of crypto_skcipher into
> > > account.  See the comment above CRYPTO_ALG_ALLOCATES_MEMORY.
> > 
> > The block layer's queue limits is the single source of truth for what
> > the backing device at any layer can accept. If you've some constraints
> > that are not appropriately described there, then let's fix that.
> 
> I agree that dm-crypt's queue limits should accurately describe its
> constraints.  This patch makes it no longer do so.

Which one(s)?