From patchwork Tue Dec 3 12:14:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ferry Meng X-Patchwork-Id: 13892294 Received: from out30-119.freemail.mail.aliyun.com (out30-119.freemail.mail.aliyun.com [115.124.30.119]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE3F11E5005; Tue, 3 Dec 2024 12:14:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.119 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733228081; cv=none; b=cGpDptA4Zt9vc8FZqdCKEj7BlTVpHg4geNKDl8bqRGFO26Q5buaR8XG2yOJLuzkEgUSF/MsHIA7vte9yfUutuComxoi+Y9os1Pd9YH0rwnXM/jsoA6TURAsB06fJPWlwGluE9Yb0rilFgXRz0XkQKXYtLy4BlQHg3JyoWDWMg+A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733228081; c=relaxed/simple; bh=suVFN18f6l88ll5bXCZiLUvgX6JmXNTjyUNOVTCHtl8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=SxUqUDEL80S9+Jr9SQO+9PnQypJ39Nywgbu1IhKe+1tB+ykb3CuyGNqYmOTZoVBXQ5EyXXsoChscHwtEh6+3RuRbnh+PBIDv+5iliY1Sw978XYjsOn9OjYJOYBxWWDdjkV9F7wjWhN3KejEbF9ELEJaPiPGicIIf1+ugMERXRKo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=HLr11tAw; arc=none smtp.client-ip=115.124.30.119 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="HLr11tAw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1733228074; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=hM3NMjNyhiKp7OTl4GYAGnFmUrECoxmiKjcfQlgfIyg=; b=HLr11tAwKXIWlPOIlUM5m8OCYcgca8hF1UT9h3Ppo0srhfE6a2bO73TzX3O91D0JjcPxvn+bU+q+j7UippDvGVImlRpGTvgapUd5M0a9pCZlEdUGEi9GR4uy7RvNxZKS+z1j3fxyIwfSGDOryyaoiRldWlBtJOD4+cPwkLraRNg= Received: from j66c13357.sqa.eu95.tbsite.net(mailfrom:mengferry@linux.alibaba.com fp:SMTPD_---0WKmboUc_1733228073 cluster:ay36) by smtp.aliyun-inc.com; Tue, 03 Dec 2024 20:14:34 +0800 From: Ferry Meng To: "Michael S . Tsirkin" , Jason Wang , linux-block@vger.kernel.org, Jens Axboe , virtualization@lists.linux.dev Cc: linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, Joseph Qi , Jeffle Xu , Ferry Meng Subject: [PATCH 1/3] virtio-blk: add virtio-blk chardev support. Date: Tue, 3 Dec 2024 20:14:22 +0800 Message-Id: <20241203121424.19887-2-mengferry@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20241203121424.19887-1-mengferry@linux.alibaba.com> References: <20241203121424.19887-1-mengferry@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Introduce character interfaces for block device (per-device), facilitating access to block devices through io_uring I/O passsthrough. Besides, vblk initialize only use kmalloc with GFP_KERNEL flag, but for char device support, we should ensure cdev kobj must be zero before initialize. So better initial this struct with __GFP_ZERO flag. Now the character devices only named as - /dev/vdXc0 Currently, only one character interface is created for one actual virtblk device, although it has been partitioned. Signed-off-by: Ferry Meng --- drivers/block/virtio_blk.c | 84 +++++++++++++++++++++++++++++++++++++- 1 file changed, 83 insertions(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 194417abc105..3487aaa67514 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -17,6 +17,7 @@ #include #include #include +#include #define PART_BITS 4 #define VQ_NAME_LEN 16 @@ -25,6 +26,8 @@ /* The maximum number of sg elements that fit into a virtqueue */ #define VIRTIO_BLK_MAX_SG_ELEMS 32768 +#define VIRTBLK_MINORS (1U << MINORBITS) + #ifdef CONFIG_ARCH_NO_SG_CHAIN #define VIRTIO_BLK_INLINE_SG_CNT 0 #else @@ -45,6 +48,10 @@ MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/ static int major; static DEFINE_IDA(vd_index_ida); +static DEFINE_IDA(vd_chr_minor_ida); +static dev_t vd_chr_devt; +static struct class *vd_chr_class; + static struct workqueue_struct *virtblk_wq; struct virtio_blk_vq { @@ -84,6 +91,10 @@ struct virtio_blk { /* For zoned device */ unsigned int zone_sectors; + + /* For passthrough cmd */ + struct cdev cdev; + struct device cdev_device; }; struct virtblk_req { @@ -1239,6 +1250,55 @@ static const struct blk_mq_ops virtio_mq_ops = { .poll = virtblk_poll, }; +static void virtblk_cdev_rel(struct device *dev) +{ + ida_free(&vd_chr_minor_ida, MINOR(dev->devt)); +} + +static void virtblk_cdev_del(struct cdev *cdev, struct device *cdev_device) +{ + cdev_device_del(cdev, cdev_device); + put_device(cdev_device); +} + +static int virtblk_cdev_add(struct virtio_blk *vblk, + const struct file_operations *fops) +{ + struct cdev *cdev = &vblk->cdev; + struct device *cdev_device = &vblk->cdev_device; + int minor, ret; + + minor = ida_alloc(&vd_chr_minor_ida, GFP_KERNEL); + if (minor < 0) + return minor; + + cdev_device->parent = &vblk->vdev->dev; + cdev_device->devt = MKDEV(MAJOR(vd_chr_devt), minor); + cdev_device->class = vd_chr_class; + cdev_device->release = virtblk_cdev_rel; + device_initialize(cdev_device); + + ret = dev_set_name(cdev_device, "%sc0", vblk->disk->disk_name); + if (ret) + goto err; + + cdev_init(cdev, fops); + ret = cdev_device_add(cdev, cdev_device); + if (ret) { + put_device(cdev_device); + goto err; + } + return ret; + +err: + ida_free(&vd_chr_minor_ida, minor); + return ret; +} + +static const struct file_operations virtblk_chr_fops = { + .owner = THIS_MODULE, +}; + static unsigned int virtblk_queue_depth; module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); @@ -1456,7 +1516,7 @@ static int virtblk_probe(struct virtio_device *vdev) goto out; index = err; - vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); + vdev->priv = vblk = kzalloc(sizeof(*vblk), GFP_KERNEL); if (!vblk) { err = -ENOMEM; goto out_free_index; @@ -1544,6 +1604,10 @@ static int virtblk_probe(struct virtio_device *vdev) if (err) goto out_cleanup_disk; + err = virtblk_cdev_add(vblk, &virtblk_chr_fops); + if (err) + goto out_cleanup_disk; + return 0; out_cleanup_disk: @@ -1568,6 +1632,8 @@ static void virtblk_remove(struct virtio_device *vdev) /* Make sure no work handler is accessing the device. */ flush_work(&vblk->config_work); + virtblk_cdev_del(&vblk->cdev, &vblk->cdev_device); + del_gendisk(vblk->disk); blk_mq_free_tag_set(&vblk->tag_set); @@ -1674,13 +1740,27 @@ static int __init virtio_blk_init(void) goto out_destroy_workqueue; } + error = alloc_chrdev_region(&vd_chr_devt, 0, VIRTBLK_MINORS, + "vblk-generic"); + if (error < 0) + goto unregister_chrdev; + + vd_chr_class = class_create("vblk-generic"); + if (IS_ERR(vd_chr_class)) { + error = PTR_ERR(vd_chr_class); + goto unregister_chrdev; + } + error = register_virtio_driver(&virtio_blk); if (error) goto out_unregister_blkdev; + return 0; out_unregister_blkdev: unregister_blkdev(major, "virtblk"); +unregister_chrdev: + unregister_chrdev_region(vd_chr_devt, VIRTBLK_MINORS); out_destroy_workqueue: destroy_workqueue(virtblk_wq); return error; @@ -1690,7 +1770,9 @@ static void __exit virtio_blk_fini(void) { unregister_virtio_driver(&virtio_blk); unregister_blkdev(major, "virtblk"); + unregister_chrdev_region(vd_chr_devt, VIRTBLK_MINORS); destroy_workqueue(virtblk_wq); + ida_destroy(&vd_chr_minor_ida); } module_init(virtio_blk_init); module_exit(virtio_blk_fini);