From: Ming Lei <ming.lei@xxxxxxxxxx> Prepare for supporting IO polling for bio-based driver. Add ->poll_bio callback so that bio-based driver can provide their own logic for polling bio. Also fix ->submit_bio_bio typo in comment block above __submit_bio_noacct. Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> --- block/blk-core.c | 14 +++++++++----- block/genhd.c | 4 ++++ include/linux/blkdev.h | 2 ++ 3 files changed, 15 insertions(+), 5 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 94bf37f8e61d..ce08f0aa9dfc 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -708,7 +708,7 @@ static void __submit_bio(struct bio *bio) * * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio. * bio_list_on_stack[1] contains bios that were submitted before the current - * ->submit_bio_bio, but that haven't been processed yet. + * ->submit_bio, but that haven't been processed yet. */ static void __submit_bio_noacct(struct bio *bio) { @@ -975,7 +975,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); blk_qc_t cookie = READ_ONCE(bio->bi_cookie); - int ret; + int ret = 0; if (cookie == BLK_QC_T_NONE || !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) @@ -985,10 +985,14 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) if (blk_queue_enter(q, BLK_MQ_REQ_NOWAIT)) return 0; - if (WARN_ON_ONCE(!queue_is_mq(q))) - ret = 0; /* not yet implemented, should not happen */ - else + if (queue_is_mq(q)) { ret = blk_mq_poll(q, cookie, iob, flags); + } else { + struct gendisk *disk = q->disk; + + if (disk && disk->fops->poll_bio) + ret = disk->fops->poll_bio(bio, iob, flags); + } blk_queue_exit(q); return ret; } diff --git a/block/genhd.c b/block/genhd.c index e351fac41bf2..1ed46a6f94f5 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -410,6 +410,10 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, struct device *ddev = disk_to_dev(disk); int ret; + /* Only makes sense for bio-based to set ->poll_bio */ + if (queue_is_mq(disk->queue) && disk->fops->poll_bio) + return -EINVAL; + /* * The disk queue should now be all set with enough information about * the device for the elevator code to pick an adequate default diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f757f9c2871f..51f1b1ddbed2 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1455,6 +1455,8 @@ enum blk_unique_id { struct block_device_operations { void (*submit_bio)(struct bio *bio); + int (*poll_bio)(struct bio *bio, struct io_comp_batch *iob, + unsigned int flags); int (*open) (struct block_device *, fmode_t); void (*release) (struct gendisk *, fmode_t); int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int); -- 2.15.0 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel