[dm-devel] NULL pointer due to malformed bcache bio

[Kent Overstreet]

On Wed, Apr 10, 2013 at 04:54:40PM -0400, Mike Snitzer wrote:
> Hey,
> 
> So DM core clearly needs to be more defensive about the possibility for
> a NULL return from bio_alloc_bioset() given I'm hitting a NULL pointer
> in DM's alloc_tio() because nr_iovecs=512.  bio_alloc_bioset()'s call to
> bvec_alloc() only supports nr_iovecs up to BIO_MAX_PAGES (256).

I have a fix for this queued up in my bcache-for-upstream, if you want
to check and make sure it works.