From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) by mail19.linbit.com (LINBIT Mail Daemon) with ESMTP id 622144205A5 for ; Wed, 6 Mar 2024 15:04:18 +0100 (CET) Received: by mail-ed1-f50.google.com with SMTP id 4fb4d7f45d1cf-5643ae47cd3so9033677a12.3 for ; Wed, 06 Mar 2024 06:04:18 -0800 (PST) From: Philipp Reisner To: Jens Axboe Subject: [PATCH 3/7] drbd: refactor the backing dev max_segments calculation Date: Wed, 6 Mar 2024 15:03:28 +0100 Message-Id: <20240306140332.623759-4-philipp.reisner@linbit.com> In-Reply-To: <20240305134041.137006-1-hch@lst.de> References: <20240305134041.137006-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Philipp Reisner , linux-block@vger.kernel.org, Lars Ellenberg , Christoph Hellwig , drbd-dev@lists.linbit.com List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Christoph Hellwig Factor out a drbd_backing_dev_max_segments helper that checks the backing device limitation. Signed-off-by: Christoph Hellwig Reviewed-by: Philipp Reisner Reviewed-by: Lars Ellenberg Tested-by: Christoph Böhmwalder --- 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