From nobody Mon Dec 1 23:33:18 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 457A4288517 for ; Mon, 1 Dec 2025 21:43:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764625429; cv=none; b=TUEypiJLid9jvxrKEmXNZyicvdWF0P1FEDaER9lhEkuBRrc/1+LsEW52FGJDQd9gkJ0RuMItWFiiiYegd5ysKLJReMW0DVeXKsqb5QvfQ4q7W2HjaB4qJBVq3QreiKHZIRdERvLXHDW7v0i7KeWZMbjTLlgx/aDObblZ+xiQFf8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764625429; c=relaxed/simple; bh=c9ook15FSerManL9572l4zd35YBmRIHqvbSn6rbz9AM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=szU5XKfb7gcfmOVs/fiB8R72xd5RcmwYzyN2i6M/u8SpiQVZ91iX213nYjeGHeDPZ0oT8EXJUhl7hlHSKX0yBp+JEuONkDXzFAXZk0l7W/4m/0VTPAbQQTk9HpZ4PDxBVc+G5GbRwJWx5zlIqixEv7O8eHDeAHBmRxA2j+04ZYU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=PRexTt2O; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PRexTt2O" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764625426; 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=fKTaK8YQ8JlnEYeloVBNBHe/TIb+9zuKgvDOA4diXFc=; b=PRexTt2O3P9IMTfMqeWu678rP5YhkVN3D9XghEvETFtkHiuBPpX+z8hEuClqFUOKSZWbSn JOj3vKMjv8Jy68XCknFGTt+sv/LQ3w4AG9v3iBeVRq/5AqbmBYtKoLo6eTvBUczsAmk+v1 JW6tadrPbIqaPse8toCdHRIc1fV91Vo= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-108-2KT_SfgRPoq8WMSkKWvSyw-1; Mon, 01 Dec 2025 16:43:43 -0500 X-MC-Unique: 2KT_SfgRPoq8WMSkKWvSyw-1 X-Mimecast-MFC-AGG-ID: 2KT_SfgRPoq8WMSkKWvSyw_1764625421 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 54099195605F; Mon, 1 Dec 2025 21:43:41 +0000 (UTC) Received: from localhost (unknown [10.2.16.172]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 95B711800876; Mon, 1 Dec 2025 21:43:40 +0000 (UTC) From: Stefan Hajnoczi To: linux-block@vger.kernel.org Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, "James E.J. Bottomley" , "Martin K. Petersen" , Keith Busch , Jens Axboe , Sagi Grimberg , Mike Christie , Krzysztof Kozlowski , linux-nvme@lists.infradead.org, Stefan Hajnoczi , Hannes Reinecke Subject: [PATCH v3 4/4] block: add IOC_PR_READ_RESERVATION ioctl Date: Mon, 1 Dec 2025 16:43:29 -0500 Message-ID: <20251201214329.933945-5-stefanha@redhat.com> In-Reply-To: <20251201214329.933945-1-stefanha@redhat.com> References: <20251201214329.933945-1-stefanha@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Content-Type: text/plain; charset="utf-8" Add a Persistent Reservations ioctl to read the current reservation. This calls the pr_ops->read_reservation() function that was previously added in commit c787f1baa503 ("block: Add PR callouts for read keys and reservation") but was only used by the in-kernel SCSI target so far. The IOC_PR_READ_RESERVATION ioctl is necessary so that userspace applications that rely on Persistent Reservations ioctls have a way of inspecting the current state. Cluster managers and validation tests need this functionality. Signed-off-by: Stefan Hajnoczi Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig --- include/uapi/linux/pr.h | 7 +++++++ block/ioctl.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/include/uapi/linux/pr.h b/include/uapi/linux/pr.h index fcb74eab92c80..847f3051057af 100644 --- a/include/uapi/linux/pr.h +++ b/include/uapi/linux/pr.h @@ -62,6 +62,12 @@ struct pr_read_keys { __u64 keys_ptr; }; =20 +struct pr_read_reservation { + __u64 key; + __u32 generation; + __u32 type; +}; + #define PR_FL_IGNORE_KEY (1 << 0) /* ignore existing key */ =20 #define IOC_PR_REGISTER _IOW('p', 200, struct pr_registration) @@ -71,5 +77,6 @@ struct pr_read_keys { #define IOC_PR_PREEMPT_ABORT _IOW('p', 204, struct pr_preempt) #define IOC_PR_CLEAR _IOW('p', 205, struct pr_clear) #define IOC_PR_READ_KEYS _IOWR('p', 206, struct pr_read_keys) +#define IOC_PR_READ_RESERVATION _IOR('p', 207, struct pr_read_reservation) =20 #endif /* _UAPI_PR_H */ diff --git a/block/ioctl.c b/block/ioctl.c index 95ce9aa90bba2..4a55d2e7602e5 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -477,6 +477,32 @@ static int blkdev_pr_read_keys(struct block_device *bd= ev, blk_mode_t mode, return ret; } =20 +static int blkdev_pr_read_reservation(struct block_device *bdev, + blk_mode_t mode, struct pr_read_reservation __user *arg) +{ + const struct pr_ops *ops =3D bdev->bd_disk->fops->pr_ops; + struct pr_held_reservation rsv =3D {}; + struct pr_read_reservation out =3D {}; + int ret; + + if (!blkdev_pr_allowed(bdev, mode)) + return -EPERM; + if (!ops || !ops->pr_read_reservation) + return -EOPNOTSUPP; + + ret =3D ops->pr_read_reservation(bdev, &rsv); + if (ret) + return ret; + + out.key =3D rsv.key; + out.generation =3D rsv.generation; + out.type =3D rsv.type; + + if (copy_to_user(arg, &out, sizeof(out))) + return -EFAULT; + return 0; +} + static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd, unsigned long arg) { @@ -700,6 +726,8 @@ static int blkdev_common_ioctl(struct block_device *bde= v, blk_mode_t mode, return blkdev_pr_clear(bdev, mode, argp); case IOC_PR_READ_KEYS: return blkdev_pr_read_keys(bdev, mode, argp); + case IOC_PR_READ_RESERVATION: + return blkdev_pr_read_reservation(bdev, mode, argp); default: return blk_get_meta_cap(bdev, cmd, argp); } --=20 2.52.0