From patchwork Fri Mar 24 18:17:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Christie X-Patchwork-Id: 13187206 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 2E00DC77B61 for ; Fri, 24 Mar 2023 18:18:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231545AbjCXSSP (ORCPT ); Fri, 24 Mar 2023 14:18:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230190AbjCXSSN (ORCPT ); Fri, 24 Mar 2023 14:18:13 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D78A6A70; Fri, 24 Mar 2023 11:18:09 -0700 (PDT) Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 32OIE3SS011947; Fri, 24 Mar 2023 18:17:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2022-7-12; bh=rej/w0yBsHdzYkty3qZTIcOQI1jK0Mox+FFsFSqnNv8=; b=gXFXWo/U0+9qr8zzpk2eVkhZYJ0FEExjLYE76ljJb7XbRJHt++867XhEtalaLdjzQt33 DGhWysLVjM7lSKd+LenNxuv2xfmMg8wq8bwIyX/aLd7vgmtownAjsiGdqGCuUmF7IdG/ QuVRh2VqITgGosOL1d5BC38XrkvraJa2g9rMXBjFPYfSGy4UzzihURW/JJaIWtz2qJPZ DZcc5gCh1BpWJqbPxuaRydMHRZ38BXWmFRyMmjDqdPJ8Z3MlvfTvclvhB9sAsH2N+H5E ZSLKKTG1paaHvPfmlempPIP+emhucUY2JJHd7YsTElrQR+SEZ8tMjGomuYqxE28ojr9L Dw== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3phgy9g08a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 24 Mar 2023 18:17:49 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.5/8.17.1.5) with ESMTP id 32OGnJYx001315; Fri, 24 Mar 2023 18:17:48 GMT Received: from pps.reinject (localhost [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3pgxk4bx3x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 24 Mar 2023 18:17:48 +0000 Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 32OIHiEL021017; Fri, 24 Mar 2023 18:17:47 GMT Received: from mnchrist-mac.us.oracle.com (dhcp-10-154-153-54.vpn.oracle.com [10.154.153.54]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3pgxk4bx19-2; Fri, 24 Mar 2023 18:17:47 +0000 From: Mike Christie To: bvanassche@acm.org, hch@lst.de, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, james.bottomley@hansenpartnership.com, linux-block@vger.kernel.org, dm-devel@redhat.com, snitzer@kernel.org, axboe@kernel.dk, linux-nvme@lists.infradead.org, chaitanyak@nvidia.com, kbusch@kernel.org, target-devel@vger.kernel.org Cc: Mike Christie , Chaitanya Kulkarni Subject: [PATCH v5 01/18] block: Add PR callouts for read keys and reservation Date: Fri, 24 Mar 2023 13:17:24 -0500 Message-Id: <20230324181741.13908-2-michael.christie@oracle.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230324181741.13908-1-michael.christie@oracle.com> References: <20230324181741.13908-1-michael.christie@oracle.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-24_11,2023-03-24_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 adultscore=0 bulkscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2303240143 X-Proofpoint-GUID: SEAyr6A4ObJgZIJbyXP6stjTQzwUjTEA X-Proofpoint-ORIG-GUID: SEAyr6A4ObJgZIJbyXP6stjTQzwUjTEA Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org Add callouts for reading keys and reservations. This allows LIO to support the READ_KEYS and READ_RESERVATION commands and will allow dm-multipath to optimize it's error handling so it can check if it's getting an error because there's an existing reservation or if we need to retry different paths. Note: This only initially adds the struct definitions in the kernel as I'm not sure if we wanted to export the interface to userspace yet. read_keys and read_reservation are exactly what dm-multipath and LIO need, but for a userspace interface we may want something like SCSI's READ_FULL_STATUS and NVMe's report reservation commands. Those are overkill for dm/LIO and READ_FULL_STATUS is sometimes broken for SCSI devices. Signed-off-by: Mike Christie Reviewed-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche --- include/linux/pr.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/linux/pr.h b/include/linux/pr.h index 94ceec713afe..3003daec28a5 100644 --- a/include/linux/pr.h +++ b/include/linux/pr.h @@ -4,6 +4,18 @@ #include +struct pr_keys { + u32 generation; + u32 num_keys; + u64 keys[]; +}; + +struct pr_held_reservation { + u64 key; + u32 generation; + enum pr_type type; +}; + struct pr_ops { int (*pr_register)(struct block_device *bdev, u64 old_key, u64 new_key, u32 flags); @@ -14,6 +26,19 @@ struct pr_ops { int (*pr_preempt)(struct block_device *bdev, u64 old_key, u64 new_key, enum pr_type type, bool abort); int (*pr_clear)(struct block_device *bdev, u64 key); + /* + * pr_read_keys - Read the registered keys and return them in the + * pr_keys->keys array. The keys array will have been allocated at the + * end of the pr_keys struct, and pr_keys->num_keys must be set to the + * number of keys the array can hold. If there are more than can fit + * in the array, success will still be returned and pr_keys->num_keys + * will reflect the total number of keys the device contains, so the + * caller can retry with a larger array. + */ + int (*pr_read_keys)(struct block_device *bdev, + struct pr_keys *keys_info); + int (*pr_read_reservation)(struct block_device *bdev, + struct pr_held_reservation *rsv); }; #endif /* LINUX_PR_H */