From: Goldwyn Rodrigues <[email protected]> Add support for bio based dm devices, which exclusively sets a make_request_fn(). Request based devices are supported by default.
Signed-off-by: Goldwyn Rodrigues <[email protected]> --- drivers/md/dm.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 6e54145969c5..b721716862a2 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1522,6 +1522,8 @@ static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio) if (!(bio->bi_opf & REQ_RAHEAD)) queue_io(md, bio); + else if (bio->bi_opf & REQ_NOWAIT) + bio_wouldblock_error(bio); else bio_io_error(bio); return BLK_QC_T_NONE; @@ -2011,6 +2013,29 @@ struct queue_limits *dm_get_queue_limits(struct mapped_device *md) } EXPORT_SYMBOL_GPL(dm_get_queue_limits); +static int device_supports_nowait(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + return q && blk_queue_supports_nowait(q); +} + +static bool dm_table_supports_nowait(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i; + + for (i = 0; i < dm_table_get_num_targets(t); i++) { + ti = dm_table_get_target(t, i); + + if (!ti->type->iterate_devices || + !ti->type->iterate_devices(ti, device_supports_nowait, NULL)) + return false; + } + + return true; +} + /* * Setup the DM device's queue based on md's type */ @@ -2044,7 +2069,8 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) */ bioset_free(md->queue->bio_split); md->queue->bio_split = NULL; - + if (dm_table_supports_nowait(t)) + queue_flag_set_unlocked(QUEUE_FLAG_NOWAIT, md->queue); if (type == DM_TYPE_DAX_BIO_BASED) queue_flag_set_unlocked(QUEUE_FLAG_DAX, md->queue); break; -- 2.14.2
