From nobody Mon Dec 1 23:05:19 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 327AA285C89 for ; Mon, 1 Dec 2025 21:43:42 +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=1764625424; cv=none; b=YJXJSWJhNeAVNElCsGfT1HVzOoS9uuOughmQeR2Eripzqfd0DaCNA9d1UBO7LwdSk+LY9T6Ga20zN/BsSsYKY04uSguJWLS3gfY3EQeKIqQzxRPIpONfD/NZrOsyHQifxa2vc/KdXN+Q2bFKrbaYJtPxZBWUNa82ezikCdbgZ34= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764625424; c=relaxed/simple; bh=TR0EdIYUty1k7XAJrVdGgQmooXt5n/aX214Ma7BluEA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DNkKHpR9W1pYJn5nIcHBpPIm4kxPUSBu1PMxvo3lCmDu8f+3oqgf1wJdl+Mqys2cA56Yq87rE27R/yAVG5nU9uA9ItvWrQWwNzaq0cy4uZcW8lhSYhXzL+zVglEVRg+YrVIDNelf6yB2awzwT84CEfTqRu0KpBC0I+TrhBZ1aMw= 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=TzhYJigm; 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="TzhYJigm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764625422; 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=PU3aIbnMU+BuREK+bEcl6eAdFWIrI+XOFPkJF/Fkm1k=; b=TzhYJigmjLBYeoDv2DQ/27soAHAQz4hrh2zu5LZWHHcFCbzzpwl6q+XhKlbLdF+QSZmRtX Y+Gje7mQPiGa2cRC/yhEU8LEeZrsv+UqFLDeLSYbJ/Fc3B9dpwCK5nqRNtrKSQNjvseele fxzFV5McIpT+HmnJbnTP2PFO7eqLrms= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-684-_SWH00H-NZm_sx_DcSsCYA-1; Mon, 01 Dec 2025 16:43:37 -0500 X-MC-Unique: _SWH00H-NZm_sx_DcSsCYA-1 X-Mimecast-MFC-AGG-ID: _SWH00H-NZm_sx_DcSsCYA_1764625415 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 021DA180048E; Mon, 1 Dec 2025 21:43:35 +0000 (UTC) Received: from localhost (unknown [10.2.16.172]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7D34330001A4; Mon, 1 Dec 2025 21:43:33 +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 Subject: [PATCH v3 1/4] scsi: sd: reject invalid pr_read_keys() num_keys values Date: Mon, 1 Dec 2025 16:43:26 -0500 Message-ID: <20251201214329.933945-2-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 10.30.177.4 Content-Type: text/plain; charset="utf-8" The pr_read_keys() interface has a u32 num_keys parameter. The SCSI PERSISTENT RESERVE IN command has a maximum READ KEYS service action size of 65536 bytes. Reject num_keys values that are too large to fit into the SCSI command. This will become important when pr_read_keys() is exposed to untrusted userspace via an ioctl. Signed-off-by: Stefan Hajnoczi --- drivers/scsi/sd.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 0252d3f6bed17..32ae4898cea7c 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1974,9 +1974,19 @@ static int sd_pr_read_keys(struct block_device *bdev= , struct pr_keys *keys_info) { int result, i, data_offset, num_copy_keys; u32 num_keys =3D keys_info->num_keys; - int data_len =3D num_keys * 8 + 8; + int data_len; u8 *data; =20 + /* + * Each reservation key takes 8 bytes and there is an 8-byte header + * before the reservation key list. The total size must fit into the + * 16-bit ALLOCATION LENGTH field. + */ + if (check_mul_overflow(num_keys, 8, &data_len) || + check_add_overflow(data_len, 8, &data_len) || + data_len > USHRT_MAX) + return -EINVAL; + data =3D kzalloc(data_len, GFP_KERNEL); if (!data) return -ENOMEM; --=20 2.52.0 From nobody Mon Dec 1 23:05:19 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 3281B285C8C for ; Mon, 1 Dec 2025 21:43:42 +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=1764625424; cv=none; b=DkKo7r1+QufSE2Ly+gwcyhlm5iWQ/378zck64E+kur2glW6Nc42yZ21CeEaPbYsW5N/3dFyR0npGV8BPyFP8xwFIXX3Nz3Aoc7HfAB6yHJfe0gftl3JR4uZnKDSz8y1yTP+2efmJc6vdbaJRzmQMqLuY1uZij4tXg8DV2yqKLIs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764625424; c=relaxed/simple; bh=49L/LnDII58bUSi0yl2+j9Hx3Cuk6PLob2aDru1JQdY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KmIyzzjE45Okb87YivUBlHACtgoYp/GOu7Pk/KfTdWOy7rbO+QvVZvnvryoD6I/srTovSeil47UuFXZNePw+ftT9/cY/3Gv1SqzCdf6aRSntOT1hmIkj/rpJgBlidyQ4PGVYb1faDhWCB4CngrAQAmVXu8tF2O/eBFAkHo1aVpA= 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=eAWLZzBe; 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="eAWLZzBe" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764625422; 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=jMFwoOksHHE5cqY2VlDWWpug5apQFnrEoUUMM1BHdZM=; b=eAWLZzBeBfjP49ZqkYITU7FeNncOTCh17LNpsfWIcBaSkB8D0ElWkSRqxgFBGeHxHZ0+HW fYTXBfRTU8DyvuAqtB6fiu7wFRZ5eJsKSlltw8y8uStqVxfd9zZYGbPHdJIQGuOGk9mxok XHcD3Pue4U379RpfvLAld9Ylb/pRRxA= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-528-l0f1X0LbMJCJ0PRFNBW5jQ-1; Mon, 01 Dec 2025 16:43:39 -0500 X-MC-Unique: l0f1X0LbMJCJ0PRFNBW5jQ-1 X-Mimecast-MFC-AGG-ID: l0f1X0LbMJCJ0PRFNBW5jQ_1764625417 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 25C4F1800343; Mon, 1 Dec 2025 21:43:37 +0000 (UTC) Received: from localhost (unknown [10.2.16.172]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7E79A19560A7; Mon, 1 Dec 2025 21:43:36 +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 Subject: [PATCH v3 2/4] nvme: reject invalid pr_read_keys() num_keys values Date: Mon, 1 Dec 2025 16:43:27 -0500 Message-ID: <20251201214329.933945-3-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 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" The pr_read_keys() interface has a u32 num_keys parameter. The NVMe Reservation Report command has a u32 maximum length. Reject num_keys values that are too large to fit. This will become important when pr_read_keys() is exposed to untrusted userspace via an ioctl. Signed-off-by: Stefan Hajnoczi --- drivers/nvme/host/pr.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c index ca6a74607b139..ad2ecc2f49a97 100644 --- a/drivers/nvme/host/pr.c +++ b/drivers/nvme/host/pr.c @@ -228,7 +228,8 @@ static int nvme_pr_resv_report(struct block_device *bde= v, void *data, static int nvme_pr_read_keys(struct block_device *bdev, struct pr_keys *keys_info) { - u32 rse_len, num_keys =3D keys_info->num_keys; + size_t rse_len; + u32 num_keys =3D keys_info->num_keys; struct nvme_reservation_status_ext *rse; int ret, i; bool eds; @@ -238,6 +239,9 @@ static int nvme_pr_read_keys(struct block_device *bdev, * enough to get enough keys to fill the return keys buffer. */ rse_len =3D struct_size(rse, regctl_eds, num_keys); + if (rse_len > U32_MAX) + return -EINVAL; + rse =3D kzalloc(rse_len, GFP_KERNEL); if (!rse) return -ENOMEM; --=20 2.52.0 From nobody Mon Dec 1 23:05:19 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 03F9F28727A for ; Mon, 1 Dec 2025 21:43:45 +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=1764625427; cv=none; b=AirGw+Xqs+/hDTnwQhBxVJGXxZreryWjemUIJkd5Yd/RftxDRMLCjBewxqTNc2+3wvm5XGdbZWmm9NWlJsFbY+VGu+2wL1a9HkJe++577BQMe1bdfZ5t+J7RgBs9NNLTMZaTg40l4TMcTZPsHJ2DGtirAMW7xmsXVOJJVsXrFHE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764625427; c=relaxed/simple; bh=NqAD7IKNmEKH9tDaD4XtjDhDUpCRgB85D8rfNscxioY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mwIrTwIcX/j2+zCQedSMDA/1/wPfvQW+FnUP9enSS7YHmxGgLwE70PlopLyWdVd6yZOk7LxnINZw5UQRpv/A44nRSwRdItXp7DjP3WdQEaIBlJ/q7+PKY0s7RhfoP1bDIsj2LFRBuFo/ttfCPJsGLf+fnbw1DQrmzZ88jtq3sFM= 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=Uwaf86gP; 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="Uwaf86gP" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764625425; 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=tmEzslKSkhmC0gLB9i+o3Qufbcn1D02jCo9kyVUqdsk=; b=Uwaf86gPuYM42tuzBPXA7K+xYlLitW9R70AsnmvssM1z6uZJRyTFvQBPi5vNFHxOtDeF+O jOyWgOAiXP+EHY4HWtnmIVE3MicywvpWU+M5b8H3a6cGa3oyfbLobAf2AdlU3pwFGR+/zM 1DxTaCSwQfmcs6pxp8qApoXYXd6iFRc= Received: from mx-prod-mc-05.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-296-pvHD_HxaPw-VDLFQazgHzw-1; Mon, 01 Dec 2025 16:43:41 -0500 X-MC-Unique: pvHD_HxaPw-VDLFQazgHzw-1 X-Mimecast-MFC-AGG-ID: pvHD_HxaPw-VDLFQazgHzw_1764625419 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1B9A719560A1; Mon, 1 Dec 2025 21:43:39 +0000 (UTC) Received: from localhost (unknown [10.2.16.172]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8BCA71956095; Mon, 1 Dec 2025 21:43:38 +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 Subject: [PATCH v3 3/4] block: add IOC_PR_READ_KEYS ioctl Date: Mon, 1 Dec 2025 16:43:28 -0500 Message-ID: <20251201214329.933945-4-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 3.0 on 10.30.177.17 Content-Type: text/plain; charset="utf-8" Add a Persistent Reservations ioctl to read the list of currently registered reservation keys. This calls the pr_ops->read_keys() 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_KEYS 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 --- include/uapi/linux/pr.h | 7 ++++++ block/ioctl.c | 56 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 63 insertions(+) diff --git a/include/uapi/linux/pr.h b/include/uapi/linux/pr.h index d8126415966f3..fcb74eab92c80 100644 --- a/include/uapi/linux/pr.h +++ b/include/uapi/linux/pr.h @@ -56,6 +56,12 @@ struct pr_clear { __u32 __pad; }; =20 +struct pr_read_keys { + __u32 generation; + __u32 num_keys; + __u64 keys_ptr; +}; + #define PR_FL_IGNORE_KEY (1 << 0) /* ignore existing key */ =20 #define IOC_PR_REGISTER _IOW('p', 200, struct pr_registration) @@ -64,5 +70,6 @@ struct pr_clear { #define IOC_PR_PREEMPT _IOW('p', 203, struct pr_preempt) #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) =20 #endif /* _UAPI_PR_H */ diff --git a/block/ioctl.c b/block/ioctl.c index d7489a56b33c3..95ce9aa90bba2 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -423,6 +423,60 @@ static int blkdev_pr_clear(struct block_device *bdev, = blk_mode_t mode, return ops->pr_clear(bdev, c.key); } =20 +static int blkdev_pr_read_keys(struct block_device *bdev, blk_mode_t mode, + struct pr_read_keys __user *arg) +{ + const struct pr_ops *ops =3D bdev->bd_disk->fops->pr_ops; + struct pr_keys *keys_info; + struct pr_read_keys read_keys; + u64 __user *keys_ptr; + size_t keys_info_len; + size_t keys_copy_len; + int ret; + + if (!blkdev_pr_allowed(bdev, mode)) + return -EPERM; + if (!ops || !ops->pr_read_keys) + return -EOPNOTSUPP; + + if (copy_from_user(&read_keys, arg, sizeof(read_keys))) + return -EFAULT; + + keys_info_len =3D struct_size(keys_info, keys, read_keys.num_keys); + if (keys_info_len =3D=3D SIZE_MAX) + return -EINVAL; + + keys_info =3D kzalloc(keys_info_len, GFP_KERNEL); + if (!keys_info) + return -ENOMEM; + + keys_info->num_keys =3D read_keys.num_keys; + + ret =3D ops->pr_read_keys(bdev, keys_info); + if (ret) + goto out; + + /* Copy out individual keys */ + keys_ptr =3D u64_to_user_ptr(read_keys.keys_ptr); + keys_copy_len =3D min(read_keys.num_keys, keys_info->num_keys) * + sizeof(keys_info->keys[0]); + + if (copy_to_user(keys_ptr, keys_info->keys, keys_copy_len)) { + ret =3D -EFAULT; + goto out; + } + + /* Copy out the arg struct */ + read_keys.generation =3D keys_info->generation; + read_keys.num_keys =3D keys_info->num_keys; + + if (copy_to_user(arg, &read_keys, sizeof(read_keys))) + ret =3D -EFAULT; +out: + kfree(keys_info); + return ret; +} + static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd, unsigned long arg) { @@ -644,6 +698,8 @@ static int blkdev_common_ioctl(struct block_device *bde= v, blk_mode_t mode, return blkdev_pr_preempt(bdev, mode, argp, true); case IOC_PR_CLEAR: return blkdev_pr_clear(bdev, mode, argp); + case IOC_PR_READ_KEYS: + return blkdev_pr_read_keys(bdev, mode, argp); default: return blk_get_meta_cap(bdev, cmd, argp); } --=20 2.52.0 From nobody Mon Dec 1 23:05:19 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 ; 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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