Commit 342d81fd authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

drbd: refactor drbd_reconsider_queue_parameters 



Split out a drbd_max_peer_bio_size helper for the peer I/O size,
and condense the various checks to a nested min3(..., max())) instead
of using a lot of local variables.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240305134041.137006-3-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent aa067325

drivers/block/drbd/drbd_nl.c

+49 −35
Original line number Diff line number Diff line
@@ -1189,6 +1189,33 @@ static int drbd_check_al_size(struct drbd_device *device, struct disk_conf *dc) 
	return 0;

}



static unsigned int drbd_max_peer_bio_size(struct drbd_device *device)

{

	/*

	 * We may ignore peer limits if the peer is modern enough.  From 8.3.8

	 * onwards the peer can use multiple BIOs for a single peer_request.

	 */

	if (device->state.conn < C_WF_REPORT_PARAMS)

		return device->peer_max_bio_size;



	if (first_peer_device(device)->connection->agreed_pro_version < 94)

		return min(device->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);



	/*

	 * Correct old drbd (up to 8.3.7) if it believes it can do more than

	 * 32KiB.

	 */

	if (first_peer_device(device)->connection->agreed_pro_version == 94)

		return DRBD_MAX_SIZE_H80_PACKET;



	/*

	 * drbd 8.3.8 onwards, before 8.4.0

	 */

	if (first_peer_device(device)->connection->agreed_pro_version < 100)

		return DRBD_MAX_BIO_SIZE_P95;

	return DRBD_MAX_BIO_SIZE;

}



static void blk_queue_discard_granularity(struct request_queue *q, unsigned int granularity)

{

	q->limits.discard_granularity = granularity;
@@ -1303,48 +1330,35 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi 
	fixup_discard_support(device, q);

}



void drbd_reconsider_queue_parameters(struct drbd_device *device, struct drbd_backing_dev *bdev, struct o_qlim *o)

void drbd_reconsider_queue_parameters(struct drbd_device *device,

		struct drbd_backing_dev *bdev, struct o_qlim *o)

{

	unsigned int now, new, local, peer;



	now = queue_max_hw_sectors(device->rq_queue) << 9;

	local = device->local_max_bio_size; /* Eventually last known value, from volatile memory */

	peer = device->peer_max_bio_size; /* Eventually last known value, from meta data */

	unsigned int now = queue_max_hw_sectors(device->rq_queue) <<

			SECTOR_SHIFT;

	unsigned int new;



	if (bdev) {

		local = queue_max_hw_sectors(bdev->backing_bdev->bd_disk->queue) << 9;

		device->local_max_bio_size = local;

	}

	local = min(local, DRBD_MAX_BIO_SIZE);



	/* We may ignore peer limits if the peer is modern enough.

	   Because new from 8.3.8 onwards the peer can use multiple

	   BIOs for a single peer_request */

	if (device->state.conn >= C_WF_REPORT_PARAMS) {

		if (first_peer_device(device)->connection->agreed_pro_version < 94)

			peer = min(device->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);

			/* Correct old drbd (up to 8.3.7) if it believes it can do more than 32KiB */

		else if (first_peer_device(device)->connection->agreed_pro_version == 94)

			peer = DRBD_MAX_SIZE_H80_PACKET;

		else if (first_peer_device(device)->connection->agreed_pro_version < 100)

			peer = DRBD_MAX_BIO_SIZE_P95;  /* drbd 8.3.8 onwards, before 8.4.0 */

		else

			peer = DRBD_MAX_BIO_SIZE;

		struct request_queue *b = bdev->backing_bdev->bd_disk->queue;



		/* We may later detach and re-attach on a disconnected Primary.

		 * Avoid this setting to jump back in that case.

		 * We want to store what we know the peer DRBD can handle,

		 * not what the peer IO backend can handle. */

		if (peer > device->peer_max_bio_size)

			device->peer_max_bio_size = peer;

		device->local_max_bio_size =

			queue_max_hw_sectors(b) << SECTOR_SHIFT;

	}

	new = min(local, peer);



	/*

	 * We may later detach and re-attach on a disconnected Primary.  Avoid

	 * decreasing the value in this case.

	 *

	 * We want to store what we know the peer DRBD can handle, not what the

	 * peer IO backend can handle.

	 */

	new = min3(DRBD_MAX_BIO_SIZE, device->local_max_bio_size,

		max(drbd_max_peer_bio_size(device), device->peer_max_bio_size));

	if (new != now) {

		if (device->state.role == R_PRIMARY && new < now)

		drbd_err(device, "ASSERT FAILED new < now; (%u < %u)\n", new, now);



	if (new != now)

			drbd_err(device, "ASSERT FAILED new < now; (%u < %u)\n",

					new, now);

		drbd_info(device, "max BIO size = %u\n", new);

	}



	drbd_setup_queue_param(device, bdev, new, o);

}