From patchwork Wed Feb 9 08:21:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 541312 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 997E0C433FE for ; Wed, 9 Feb 2022 08:21:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241081AbiBIIVs (ORCPT ); Wed, 9 Feb 2022 03:21:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241009AbiBIIVo (ORCPT ); Wed, 9 Feb 2022 03:21:44 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0617C05CB8C; Wed, 9 Feb 2022 00:21:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=F2lIZdBncpE9NDo/cYhvW0BcY5k8p1Xy0zkeny0OuCE=; b=pm8/6EA1MklZpU91ac7ttgR1yv iAfCmchEDh+O3/gwYXKpLpPMsl2q/V6G+Df+WJKA72rIpcKNiR7t4M3DBX99tiPC1A94F/OQAIzfj ii6UisZBqnzWVLpgzoxAKknFdJEbj03W3INLbruwZ6VCzLlUElFxG05UNQy4Ys2ycsStkDggzrlku /nFPUvV86l1axSa4JUkZ3yh/GKtKF5UXVjk4KEI8gIGzK0efZ7z6zg/Pmv8QRUYSWNekmU02F5mp1 K77f4vMG0I8emFqrR+tkvwQLzn12m7XsvUCYeOVEbzld+txku58ng5tOj5TOwlV10qa8uiAzUIvZ9 dHhpmhhQ==; Received: from [2001:4bb8:188:3efc:ea2:7599:7eeb:4b5a] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHiEM-00GbCA-Cj; Wed, 09 Feb 2022 08:21:38 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Maxim Levitsky , Alex Dubov , Ulf Hansson , linux-block@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mmc@vger.kernel.org Subject: [PATCH 5/5] virtio_blk: simplify refcounting Date: Wed, 9 Feb 2022 09:21:20 +0100 Message-Id: <20220209082121.2628452-6-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209082121.2628452-1-hch@lst.de> References: <20220209082121.2628452-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Implement the ->free_disk method to free the virtio_blk structure only once the last gendisk reference goes away instead of keeping a local refcount. Signed-off-by: Christoph Hellwig Acked-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi --- drivers/block/virtio_blk.c | 74 +++++++++++--------------------------- 1 file changed, 21 insertions(+), 53 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c443cd64fc9b4..05cc5451d6cc1 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -69,13 +69,6 @@ struct virtio_blk { /* Process context for config space updates */ struct work_struct config_work; - /* - * Tracks references from block_device_operations open/release and - * virtio_driver probe/remove so this object can be freed once no - * longer in use. - */ - refcount_t refs; - /* What host tells us, plus 2 for header & tailer. */ unsigned int sg_elems; @@ -391,43 +384,6 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str) return err; } -static void virtblk_get(struct virtio_blk *vblk) -{ - refcount_inc(&vblk->refs); -} - -static void virtblk_put(struct virtio_blk *vblk) -{ - if (refcount_dec_and_test(&vblk->refs)) { - ida_simple_remove(&vd_index_ida, vblk->index); - mutex_destroy(&vblk->vdev_mutex); - kfree(vblk); - } -} - -static int virtblk_open(struct block_device *bd, fmode_t mode) -{ - struct virtio_blk *vblk = bd->bd_disk->private_data; - int ret = 0; - - mutex_lock(&vblk->vdev_mutex); - - if (vblk->vdev) - virtblk_get(vblk); - else - ret = -ENXIO; - - mutex_unlock(&vblk->vdev_mutex); - return ret; -} - -static void virtblk_release(struct gendisk *disk, fmode_t mode) -{ - struct virtio_blk *vblk = disk->private_data; - - virtblk_put(vblk); -} - /* We provide getgeo only to please some old bootloader/partitioning tools */ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) { @@ -460,11 +416,19 @@ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) return ret; } +static void virtblk_free_disk(struct gendisk *disk) +{ + struct virtio_blk *vblk = disk->private_data; + + ida_simple_remove(&vd_index_ida, vblk->index); + mutex_destroy(&vblk->vdev_mutex); + kfree(vblk); +} + static const struct block_device_operations virtblk_fops = { - .owner = THIS_MODULE, - .open = virtblk_open, - .release = virtblk_release, - .getgeo = virtblk_getgeo, + .owner = THIS_MODULE, + .getgeo = virtblk_getgeo, + .free_disk = virtblk_free_disk, }; static int index_to_minor(int index) @@ -791,8 +755,6 @@ static int virtblk_probe(struct virtio_device *vdev) goto out_free_index; } - /* This reference is dropped in virtblk_remove(). */ - refcount_set(&vblk->refs, 1); mutex_init(&vblk->vdev_mutex); vblk->vdev = vdev; @@ -948,7 +910,13 @@ static int virtblk_probe(struct virtio_device *vdev) return 0; out_cleanup_disk: - blk_cleanup_disk(vblk->disk); + blk_cleanup_queue(vblk->disk->queue); + blk_mq_free_tag_set(&vblk->tag_set); + vdev->config->del_vqs(vdev); + kfree(vblk->vqs); + put_disk(vblk->disk); + return err; + out_free_tags: blk_mq_free_tag_set(&vblk->tag_set); out_free_vq: @@ -970,7 +938,7 @@ static void virtblk_remove(struct virtio_device *vdev) flush_work(&vblk->config_work); del_gendisk(vblk->disk); - blk_cleanup_disk(vblk->disk); + blk_cleanup_queue(vblk->disk->queue); blk_mq_free_tag_set(&vblk->tag_set); mutex_lock(&vblk->vdev_mutex); @@ -986,7 +954,7 @@ static void virtblk_remove(struct virtio_device *vdev) mutex_unlock(&vblk->vdev_mutex); - virtblk_put(vblk); + put_disk(vblk->disk); } #ifdef CONFIG_PM_SLEEP