Commit 998e9cbc authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

drbd: cleanup decide_on_discard_support 



Sanitize the calling conventions and use a goto label to cleanup the
code flow.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarChristoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20220415045258.199825-8-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c6f23b1a

drivers/block/drbd/drbd_nl.c

+35 −33
Original line number Diff line number Diff line
@@ -1204,39 +1204,43 @@ static unsigned int drbd_max_discard_sectors(struct drbd_connection *connection) 
}



static void decide_on_discard_support(struct drbd_device *device,

			struct request_queue *q,

			struct request_queue *b,

			bool discard_zeroes_if_aligned)

		struct drbd_backing_dev *bdev)

{

	/* q = drbd device queue (device->rq_queue)

	 * b = backing device queue (device->ldev->backing_bdev->bd_disk->queue),

	 *     or NULL if diskless

	struct drbd_connection *connection =

		first_peer_device(device)->connection;

	struct request_queue *q = device->rq_queue;



	if (bdev && !blk_queue_discard(bdev->backing_bdev->bd_disk->queue))

		goto not_supported;



	if (connection->cstate >= C_CONNECTED &&

	    !(connection->agreed_features & DRBD_FF_TRIM)) {

		drbd_info(connection,

			"peer DRBD too old, does not support TRIM: disabling discards\n");

		goto not_supported;

	}



	/*

	 * We don't care for the granularity, really.

	 *

	 * Stacking limits below should fix it for the local device.  Whether or

	 * not it is a suitable granularity on the remote device is not our

	 * problem, really. If you care, you need to use devices with similar

	 * topology on all peers.

	 */

	struct drbd_connection *connection = first_peer_device(device)->connection;

	bool can_do = b ? blk_queue_discard(b) : true;



	if (can_do && connection->cstate >= C_CONNECTED && !(connection->agreed_features & DRBD_FF_TRIM)) {

		can_do = false;

		drbd_info(connection, "peer DRBD too old, does not support TRIM: disabling discards\n");

	}

	if (can_do) {

		/* We don't care for the granularity, really.

		 * Stacking limits below should fix it for the local

		 * device.  Whether or not it is a suitable granularity

		 * on the remote device is not our problem, really. If

		 * you care, you need to use devices with similar

		 * topology on all peers. */

	blk_queue_discard_granularity(q, 512);

	q->limits.max_discard_sectors = drbd_max_discard_sectors(connection);

	blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);

		q->limits.max_write_zeroes_sectors = drbd_max_discard_sectors(connection);

	} else {

	q->limits.max_write_zeroes_sectors =

		drbd_max_discard_sectors(connection);

	return;



not_supported:

	blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);

	blk_queue_discard_granularity(q, 0);

	q->limits.max_discard_sectors = 0;

	q->limits.max_write_zeroes_sectors = 0;

}

}



static void fixup_discard_if_not_supported(struct request_queue *q)

{
@@ -1273,7 +1277,6 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi 
	unsigned int max_segments = 0;

	struct request_queue *b = NULL;

	struct disk_conf *dc;

	bool discard_zeroes_if_aligned = true;



	if (bdev) {

		b = bdev->backing_bdev->bd_disk->queue;
@@ -1282,7 +1285,6 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi 
		rcu_read_lock();

		dc = rcu_dereference(device->ldev->disk_conf);

		max_segments = dc->max_bio_bvecs;

		discard_zeroes_if_aligned = dc->discard_zeroes_if_aligned;

		rcu_read_unlock();



		blk_set_stacking_limits(&q->limits);
@@ -1292,7 +1294,7 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi 
	/* 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_segment_boundary(q, PAGE_SIZE-1);

	decide_on_discard_support(device, q, b, discard_zeroes_if_aligned);

	decide_on_discard_support(device, bdev);



	if (b) {

		blk_stack_limits(&q->limits, &b->limits, 0);