From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
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 <rgoldwyn@xxxxxxxx>
---
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
