From: Christoph Hellwig <hch@xxxxxx>
Factor out a drbd_backing_dev_max_segments helper that checks the
backing device limitation.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Reviewed-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
Tested-by: Christoph Böhmwalder <christoph.boehmwalder@xxxxxxxxxx>
---
drivers/block/drbd/drbd_nl.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 9135001a8e57..0326b7322ceb 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1295,30 +1295,39 @@ static void fixup_discard_support(struct drbd_device *device, struct request_que
}
}
+/* This is the workaround for "bio would need to, but cannot, be split" */
+static unsigned int drbd_backing_dev_max_segments(struct drbd_device *device)
+{
+ unsigned int max_segments;
+
+ rcu_read_lock();
+ max_segments = rcu_dereference(device->ldev->disk_conf)->max_bio_bvecs;
+ rcu_read_unlock();
+
+ if (!max_segments)
+ return BLK_MAX_SEGMENTS;
+ return max_segments;
+}
+
static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backing_dev *bdev,
unsigned int max_bio_size, struct o_qlim *o)
{
struct request_queue * const q = device->rq_queue;
unsigned int max_hw_sectors = max_bio_size >> 9;
- unsigned int max_segments = 0;
+ unsigned int max_segments = BLK_MAX_SEGMENTS;
struct request_queue *b = NULL;
- struct disk_conf *dc;
if (bdev) {
b = bdev->backing_bdev->bd_disk->queue;
max_hw_sectors = min(queue_max_hw_sectors(b), max_bio_size >> 9);
- rcu_read_lock();
- dc = rcu_dereference(device->ldev->disk_conf);
- max_segments = dc->max_bio_bvecs;
- rcu_read_unlock();
+ max_segments = drbd_backing_dev_max_segments(device);
blk_set_stacking_limits(&q->limits);
}
blk_queue_max_hw_sectors(q, max_hw_sectors);
- /* This is the workaround for "bio would need to, but cannot, be split" */
- blk_queue_max_segments(q, max_segments ? max_segments : BLK_MAX_SEGMENTS);
+ blk_queue_max_segments(q, max_segments);
blk_queue_segment_boundary(q, PAGE_SIZE-1);
decide_on_discard_support(device, bdev);
--
2.40.1
