dm: inherit QUEUE_FLAG_SG_GAPS flags from underlying queues
A DM device must inherit the QUEUE_FLAG_SG_GAPS flags from its
underlying block devices' request queues.
This fixes problems when submitting cloned requests to multipathed
devices requiring virtually contiguous buffers.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 14954d8..6554d91 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1389,6 +1389,14 @@
return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
}
+static int queue_supports_sg_gaps(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 && !test_bit(QUEUE_FLAG_SG_GAPS, &q->queue_flags);
+}
+
static bool dm_table_all_devices_attribute(struct dm_table *t,
iterate_devices_callout_fn func)
{
@@ -1509,6 +1517,11 @@
else
queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
+ if (dm_table_all_devices_attribute(t, queue_supports_sg_gaps))
+ queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS, q);
+ else
+ queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, q);
+
dm_table_set_integrity(t);
/*
