From a4afe76b2b922e6197944d7be0be7a18b53175ae Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Sat, 24 Jan 2015 15:10:49 -0700 Subject: [PATCH] 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 Signed-off-by: Mike Snitzer --- drivers/md/dm-table.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 14954d844668..6554d9148927 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -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); /*