On 28/01/2019 15:57, Christoph Hellwig wrote:
On Mon, Jan 28, 2019 at 03:36:58PM +0000, John Garry wrote:
As I understood, the problem is the scenario of calling
blk_mq_make_request()->bio_integrity_prep() where we then allocate a bio
integrity payload in calling bio_integrity_alloc().

In this case, bio_integrity_alloc() sets bio->bi_opf |= REQ_INTEGRITY, which
is no longer consistent with data.cmd_flags.

I don't see how that could happen:

static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
{
        ...

        if (!bio_integrity_prep(bio))
                return BLK_QC_T_NONE;

        ...

        data.cmd_flags = bio->bi_opf;
        rq = blk_mq_get_request(q, bio, &data);



Your code is different to mine, then I see that this has been fixed in 5.0-rc3:

commit 7809167da5c86fd6bf309b33dee7a797e263342f
Author: Ming Lei <ming....@redhat.com>
Date:   Wed Jan 16 19:08:15 2019 +0800

    block: don't lose track of REQ_INTEGRITY flag

    We need to pass bio->bi_opf after bio intergrity preparing, otherwise
    the flag of REQ_INTEGRITY may not be set on the allocated request, then
    breaks block integrity.

Fixes: f9afca4d367b ("blk-mq: pass in request/bio flags to queue mapping")
    Cc: Hannes Reinecke <h...@suse.com>
    Cc: Keith Busch <keith.bu...@intel.com>
    Signed-off-by: Ming Lei <ming....@redhat.com>
    Signed-off-by: Jens Axboe <ax...@kernel.dk>


Sorry for the noise,
John

.



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