[dm-devel] [PATCH 3/3] block: Improve bio_set_op_attrs() robustness

[Christoph Hellwig]

On Wed, Sep 14, 2016 at 10:46:22AM +0200, Bart Van Assche wrote:
> Since REQ_OP_BITS == 3 and __REQ_NR_BITS == 30 it is not that hard
> to pass an op_flags argument to bio_set_op_attrs() that is larger
> than the number of bits reserved for the op_flags argument. Complain
> if this happens. Additionally, ensure that negative arguments trigger
> a complaint (1 << ... is signed while 1U << ... is unsigned; adding
> 0U to an integer expression causes it to be promoted to an unsigned
> type).

And this does the proper check.

Reviewed-by: Christoph Hellwig <hch at lst.de>