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>
This commit is contained in:
Keith Busch 2015-01-24 15:10:49 -07:00 committed by Mike Snitzer
parent 0c8f86322f
commit a4afe76b2b
1 changed files with 13 additions and 0 deletions

View File

@ -1389,6 +1389,14 @@ static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
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 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
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);
/*