Re: [PATCH V4 10/12] block: call __bio_free in bio_endio

Shaohua Li
2017-06-29T18:35:57Z

On Thu, Jun 29, 2017 at 07:15:52PM +0200, Christoph Hellwig wrote:
> On Wed, Jun 28, 2017 at 02:42:49PM -0700, Shaohua Li wrote:
> > > bio_integrity_endio -> bio_integrity_verify_fn -> bio_integrity_process
> > > access the integrity data, so I don't think this works as-is.
> >
> > oh, I probably missed the integrity endio. could we let bio_integrity_verify_fn
> > free integrity info and and bio_endio free cgroup info?
>
> something like this (will need the cgroup fixes from you still) should
> do the trick, although it's completely untested:
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index b8a3a65f7364..b66eb92b5a00 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -102,7 +102,7 @@ EXPORT_SYMBOL(bio_integrity_alloc);
> * Description: Used to free the integrity portion of a bio. Usually
> * called from bio_free().
> */
> -void bio_integrity_free(struct bio *bio)
> +static void bio_integrity_free(struct bio *bio)
> {
> struct bio_integrity_payload *bip = bio_integrity(bio);
> struct bio_set *bs = bio->bi_pool;
> @@ -120,8 +120,8 @@ void bio_integrity_free(struct bio *bio)
> }
>
> bio->bi_integrity = NULL;
> + bio->bi_opf &= ~REQ_INTEGRITY;
> }
> -EXPORT_SYMBOL(bio_integrity_free);
>
> /**
> * bio_integrity_add_page - Attach integrity metadata
> @@ -340,12 +340,6 @@ int bio_integrity_prep(struct bio *bio)
> offset = 0;
> }
>
> - /* Install custom I/O completion handler if read verify is enabled */
> - if (bio_data_dir(bio) == READ) {
> - bip->bip_end_io = bio->bi_end_io;
> - bio->bi_end_io = bio_integrity_endio;
> - }
> -
> /* Auto-generate integrity metadata if this is a write */
> if (bio_data_dir(bio) == WRITE)
> bio_integrity_process(bio, bi->profile->generate_fn);
> @@ -370,14 +364,12 @@ static void bio_integrity_verify_fn(struct work_struct *work)
> struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
>
> bio->bi_status = bio_integrity_process(bio, bi->profile->verify_fn);
> -
> - /* Restore original bio completion handler */
> - bio->bi_end_io = bip->bip_end_io;
> + bio_integrity_free(bio);
> bio_endio(bio);

should we directly call bi_end_io here? Otherwise, looks reasonable to me.

Thanks,
Shaohua