[dm-devel] [PATCH RFC 5/7] dm: always return BLK_QC_T_NONE for bio-based device
Mike Snitzer
snitzer at redhat.com
Thu Jan 7 21:54:15 UTC 2021
On Wed, Dec 23 2020 at 6:26am -0500,
Jeffle Xu <jefflexu at linux.alibaba.com> wrote:
> Currently the returned cookie of bio-based device is not used at all.
>
> In the following patches, bio-based device will actually return a
> pointer to a specific object as the returned cookie.
In the following patch, ...
> Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
Reviewed-by: Mike Snitzer <snitzer at redhat.com>
> ---
> drivers/md/dm.c | 26 ++++++++++----------------
> 1 file changed, 10 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index 5b2f371ec4bb..03c2b867acaa 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -1252,14 +1252,13 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
> }
> EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
>
> -static blk_qc_t __map_bio(struct dm_target_io *tio)
> +static void __map_bio(struct dm_target_io *tio)
> {
> int r;
> sector_t sector;
> struct bio *clone = &tio->clone;
> struct dm_io *io = tio->io;
> struct dm_target *ti = tio->ti;
> - blk_qc_t ret = BLK_QC_T_NONE;
>
> clone->bi_end_io = clone_endio;
>
> @@ -1278,7 +1277,7 @@ static blk_qc_t __map_bio(struct dm_target_io *tio)
> case DM_MAPIO_REMAPPED:
> /* the bio has been remapped so dispatch it */
> trace_block_bio_remap(clone, bio_dev(io->orig_bio), sector);
> - ret = submit_bio_noacct(clone);
> + submit_bio_noacct(clone);
> break;
> case DM_MAPIO_KILL:
> free_tio(tio);
> @@ -1292,8 +1291,6 @@ static blk_qc_t __map_bio(struct dm_target_io *tio)
> DMWARN("unimplemented target map return value: %d", r);
> BUG();
> }
> -
> - return ret;
> }
>
> static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
> @@ -1380,7 +1377,7 @@ static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
> }
> }
>
> -static blk_qc_t __clone_and_map_simple_bio(struct clone_info *ci,
> +static void __clone_and_map_simple_bio(struct clone_info *ci,
> struct dm_target_io *tio, unsigned *len)
> {
> struct bio *clone = &tio->clone;
> @@ -1391,7 +1388,7 @@ static blk_qc_t __clone_and_map_simple_bio(struct clone_info *ci,
> if (len)
> bio_setup_sector(clone, ci->sector, *len);
>
> - return __map_bio(tio);
> + __map_bio(tio);
> }
>
> static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
> @@ -1405,7 +1402,7 @@ static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
>
> while ((bio = bio_list_pop(&blist))) {
> tio = container_of(bio, struct dm_target_io, clone);
> - (void) __clone_and_map_simple_bio(ci, tio, len);
> + __clone_and_map_simple_bio(ci, tio, len);
> }
> }
>
> @@ -1450,7 +1447,7 @@ static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
> free_tio(tio);
> return r;
> }
> - (void) __map_bio(tio);
> + __map_bio(tio);
>
> return 0;
> }
> @@ -1565,11 +1562,10 @@ static void init_clone_info(struct clone_info *ci, struct mapped_device *md,
> /*
> * Entry point to split a bio into clones and submit them to the targets.
> */
> -static blk_qc_t __split_and_process_bio(struct mapped_device *md,
> +static void __split_and_process_bio(struct mapped_device *md,
> struct dm_table *map, struct bio *bio)
> {
> struct clone_info ci;
> - blk_qc_t ret = BLK_QC_T_NONE;
> int error = 0;
>
> init_clone_info(&ci, md, map, bio);
> @@ -1613,7 +1609,7 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
>
> bio_chain(b, bio);
> trace_block_split(b, bio->bi_iter.bi_sector);
> - ret = submit_bio_noacct(bio);
> + submit_bio_noacct(bio);
> break;
> }
> }
> @@ -1621,13 +1617,11 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
>
> /* drop the extra reference count */
> dec_pending(ci.io, errno_to_blk_status(error));
> - return ret;
> }
>
> static blk_qc_t dm_submit_bio(struct bio *bio)
> {
> struct mapped_device *md = bio->bi_disk->private_data;
> - blk_qc_t ret = BLK_QC_T_NONE;
> int srcu_idx;
> struct dm_table *map;
>
> @@ -1657,10 +1651,10 @@ static blk_qc_t dm_submit_bio(struct bio *bio)
> if (is_abnormal_io(bio))
> blk_queue_split(&bio);
>
> - ret = __split_and_process_bio(md, map, bio);
> + __split_and_process_bio(md, map, bio);
> out:
> dm_put_live_table(md, srcu_idx);
> - return ret;
> + return BLK_QC_T_NONE;
> }
>
> /*-----------------------------------------------------------------
> --
> 2.27.0
>
> --
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