From nobody Mon Dec 1 22:35:05 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 B1F603385A0 for ; Thu, 27 Nov 2025 15:54:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764258886; cv=none; b=ji5NyYg0w7p94zIzjcMxSJvHwoNGD2CFRRn9KKGfqLN8eNTNlW/20mg8cg4XQyMYJet7K99AO4f1fhDxJiXna8yoEPtL7CZiG0rqVm2qRDYXJbpZsrfkFTYbbCVw7qUlsCwqm/taTfU/Q0y+ldSQIR7K5ppX6O7coQG6DQiPtm4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764258886; c=relaxed/simple; bh=egCb4rKT0BX/LR4YMOIGxOs2/u5oGoqgTPsZiXW4/1M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kJL6r4fnPEQ9tqOW/JtJCR6CKZVSvhXIkxdv2aboD5IYS1fUGkhmnm/wVppabd19nJ+bG2Gd7ZLk+e+C9SgwnHv46N9z5f8X1Q2skcKvwGd+BHYBd1VyQ8zc+u2pkXv+4pa4kM9euB2fdcXSd3rt1X4zxCVlAlccp/a13Rz34m8= 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=Xe/aq+Vh; arc=none smtp.client-ip=170.10.129.124 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="Xe/aq+Vh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764258883; 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=Or+hOooxS4SFn2ETCxdT77BmFRIW+dZi7o2KBfzpbfo=; b=Xe/aq+VhiNa4gPaeN6C7pA3a0S9wRaRTN1t2MBI53ryW119dYdVOhV+L0hAhvqjyKAe0IP SuYVDplQKoX3rPySS3Xz3oYmLIbRNg2TD6IvZ97UFt/ZNnRPb5ffSkFxHP2KhjUwS5NZMp DG7//Yl7426liLCjctBLCJ4YNRM/iKQ= 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-59-jbZUp9cMNLmpgzKEOzE8Kw-1; Thu, 27 Nov 2025 10:54:38 -0500 X-MC-Unique: jbZUp9cMNLmpgzKEOzE8Kw-1 X-Mimecast-MFC-AGG-ID: jbZUp9cMNLmpgzKEOzE8Kw_1764258875 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1A7E61800342; Thu, 27 Nov 2025 15:54:35 +0000 (UTC) Received: from localhost (unknown [10.2.16.53]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 737531800451; Thu, 27 Nov 2025 15:54:34 +0000 (UTC) From: Stefan Hajnoczi To: linux-block@vger.kernel.org Cc: Keith Busch , "Martin K. Petersen" , linux-kernel@vger.kernel.org, "James E.J. Bottomley" , Christoph Hellwig , Mike Christie , linux-nvme@lists.infradead.org, Jens Axboe , linux-scsi@vger.kernel.org, Sagi Grimberg , Stefan Hajnoczi Subject: [PATCH v2 3/4] block: add IOC_PR_READ_KEYS ioctl Date: Thu, 27 Nov 2025 10:54:23 -0500 Message-ID: <20251127155424.617569-4-stefanha@redhat.com> In-Reply-To: <20251127155424.617569-1-stefanha@redhat.com> References: <20251127155424.617569-1-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 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 Reviewed-by: Hannes Reinecke --- include/uapi/linux/pr.h | 7 +++++ block/ioctl.c | 59 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 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..63b942392b234 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include #include #include @@ -423,6 +424,62 @@ 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 __free(kfree) =3D NULL; + struct pr_read_keys inout; + u64 __user *keys_ptr; + size_t keys_info_len; + size_t keys_copy_len; + u32 num_copy_keys; + int ret; + + if (!blkdev_pr_allowed(bdev, mode)) + return -EPERM; + if (!ops || !ops->pr_read_keys) + return -EOPNOTSUPP; + + if (copy_from_user(&inout, arg, sizeof(inout))) + return -EFAULT; + + /* + * 64-bit hosts could handle more keys than 32-bit hosts, but this + * limit is more than enough in practice. + */ + if (inout.num_keys > (U32_MAX - sizeof(*keys_info)) / + sizeof(keys_info->keys[0])) + return -EINVAL; + + keys_info_len =3D struct_size(keys_info, keys, inout.num_keys); + keys_info =3D kzalloc(keys_info_len, GFP_KERNEL); + if (!keys_info) + return -ENOMEM; + + keys_info->num_keys =3D inout.num_keys; + + ret =3D ops->pr_read_keys(bdev, keys_info); + if (ret) + return ret; + + /* Copy out individual keys */ + keys_ptr =3D u64_to_user_ptr(inout.keys_ptr); + num_copy_keys =3D min(inout.num_keys, keys_info->num_keys); + keys_copy_len =3D num_copy_keys * sizeof(keys_info->keys[0]); + + if (copy_to_user(keys_ptr, keys_info->keys, keys_copy_len)) + return -EFAULT; + + /* Copy out the arg struct */ + inout.generation =3D keys_info->generation; + inout.num_keys =3D keys_info->num_keys; + + if (copy_to_user(arg, &inout, sizeof(inout))) + return -EFAULT; + return ret; +} + static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd, unsigned long arg) { @@ -644,6 +701,8 @@ 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