From mboxrd@z Thu Jan 1 00:00:00 1970 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 508D2C433FE for ; Thu, 24 Nov 2022 03:06:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229894AbiKXDGe (ORCPT ); Wed, 23 Nov 2022 22:06:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbiKXDGa (ORCPT ); Wed, 23 Nov 2022 22:06:30 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69E41C6887 for ; Wed, 23 Nov 2022 19:05:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669259129; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=73UQaimFCtbZe847Yx5Niggl9PUfx0OrnjEdDaQzOlM=; b=at6st/0nuHKsv3qJej3zBhTQWtNZ+4OPlFwhpIK5nizMEKrhTzH2hM5hSaP6BLw4++blDJ DALudxf9wFDPxKrXTQCi53rPWZ1LFKgRpRX0u//lyz4r32uKkBLHFm6Z4GeWU2N+mbEA3K Ec/fugUhE/XgBayGxXFeppIwvvHqCfE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-584-rh-Dt_n1M0me1cwanIDD5g-1; Wed, 23 Nov 2022 22:05:25 -0500 X-MC-Unique: rh-Dt_n1M0me1cwanIDD5g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 28BEA101A528; Thu, 24 Nov 2022 03:05:25 +0000 (UTC) Received: from localhost (ovpn-8-23.pek2.redhat.com [10.72.8.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id DBC50141511E; Thu, 24 Nov 2022 03:05:21 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, ZiyangZhang , Dan Carpenter , Ming Lei Subject: [PATCH V2 4/6] ublk_drv: add device parameter UBLK_PARAM_TYPE_DEVT Date: Thu, 24 Nov 2022 11:04:52 +0800 Message-Id: <20221124030454.476152-5-ming.lei@redhat.com> In-Reply-To: <20221124030454.476152-1-ming.lei@redhat.com> References: <20221124030454.476152-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Userspace side only knows device ID, but the associated path of ublkc* and ublkb* could be changed by udev, and that depends on userspace's policy, so add parameter of UBLK_PARAM_TYPE_DEVT for retrieving major/minor of the ublkc* and ublkb*, then user may figure out major/minor of the ublk disks he/she owns. With major/minor, it is easy to find the device node path. Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 24 +++++++++++++++++++++++- include/uapi/linux/ublk_cmd.h | 13 +++++++++++++ 2 files changed, 36 insertions(+), 1 deletion(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 9d1578384cba..04a28a2f2e1f 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -54,7 +54,8 @@ | UBLK_F_USER_RECOVERY_REISSUE) /* All UBLK_PARAM_TYPE_* should be included here */ -#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD) +#define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | \ + UBLK_PARAM_TYPE_DISCARD | UBLK_PARAM_TYPE_DEVT) struct ublk_rq_data { struct llist_node node; @@ -255,6 +256,10 @@ static int ublk_validate_params(const struct ublk_device *ub) return -EINVAL; } + /* dev_t is read-only */ + if (ub->params.types & UBLK_PARAM_TYPE_DEVT) + WARN_ON_ONCE(1); + return 0; } @@ -1777,6 +1782,22 @@ static int ublk_ctrl_get_dev_info(struct ublk_device *ub, return 0; } +/* TYPE_DEVT is readonly, so fill it up before returning to userspace */ +static void ublk_ctrl_fill_params_devt(struct ublk_device *ub) +{ + ub->params.devt.char_major = MAJOR(ub->cdev_dev.devt); + ub->params.devt.char_minor = MINOR(ub->cdev_dev.devt); + + if (ub->ub_disk) { + ub->params.devt.disk_major = MAJOR(disk_devt(ub->ub_disk)); + ub->params.devt.disk_minor = MINOR(disk_devt(ub->ub_disk)); + } else { + ub->params.devt.disk_major = 0; + ub->params.devt.disk_minor = 0; + } + ub->params.types |= UBLK_PARAM_TYPE_DEVT; +} + static int ublk_ctrl_get_params(struct ublk_device *ub, struct io_uring_cmd *cmd) { @@ -1798,6 +1819,7 @@ static int ublk_ctrl_get_params(struct ublk_device *ub, ph.len = sizeof(struct ublk_params); mutex_lock(&ub->mutex); + ublk_ctrl_fill_params_devt(ub); if (copy_to_user(argp, &ub->params, ph.len)) ret = -EFAULT; else diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index 8f88e3a29998..4e38b9aa0293 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -214,6 +214,17 @@ struct ublk_param_discard { __u16 reserved0; }; +/* + * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available + * after device is started + */ +struct ublk_param_devt { + __u32 char_major; + __u32 char_minor; + __u32 disk_major; + __u32 disk_minor; +}; + struct ublk_params { /* * Total length of parameters, userspace has to set 'len' for both @@ -224,10 +235,12 @@ struct ublk_params { __u32 len; #define UBLK_PARAM_TYPE_BASIC (1 << 0) #define UBLK_PARAM_TYPE_DISCARD (1 << 1) +#define UBLK_PARAM_TYPE_DEVT (1 << 2) __u32 types; /* types of parameter included */ struct ublk_param_basic basic; struct ublk_param_discard discard; + struct ublk_param_devt devt; }; #endif -- 2.31.1