From patchwork Thu Oct 29 07:54:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anand Jain X-Patchwork-Id: 11865521 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3632C55179 for ; Thu, 29 Oct 2020 07:55:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E3AC20EDD for ; Thu, 29 Oct 2020 07:55:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="rqdQlKB+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732254AbgJ2Hz4 (ORCPT ); Thu, 29 Oct 2020 03:55:56 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:44732 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731545AbgJ2Hyd (ORCPT ); Thu, 29 Oct 2020 03:54:33 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09T7nqd3191521; Thu, 29 Oct 2020 07:54:28 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-2020-01-29; bh=pTItwU2Y1igUaa3htElfHQaTdC9GCWUVYlnjExglRy8=; b=rqdQlKB+hVkpJD0hg9GqYw7OLAiEUCUq9dvaQuSaCi2BMuEfBeRdq1NQY9Lf/EaftXEW rPg/+0QeX3cb8WNyqIBh0QJNiIPclx3108ZI/gLgIOimNnDSo/IJoJoP8IOOLu90wOs2 nHuE2ld1T5dNej75DrXCe14MhsoiCAfzwhYwrrg5XOCGT+DuIVAg1DC47AIkpfyv4/OC C7jj/FkiJRhwRai/91hsnq2CRTLb42PUG0wmXQ7/xBh5We0JXWGnINcPMK0DHGA1Bn5u qCDE3gXJLlslXtYsIp8zJUUcBnsaz21Aty0BuWuDIPRo7uZNDCs7dtvVx9ZpqQCYBw75 IA== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2130.oracle.com with ESMTP id 34c9sb3dp9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 29 Oct 2020 07:54:28 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09T7pPSZ050377; Thu, 29 Oct 2020 07:54:27 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 34cx6y5y2w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Oct 2020 07:54:27 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 09T7sQOJ004458; Thu, 29 Oct 2020 07:54:26 GMT Received: from localhost.localdomain (/39.109.231.106) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 29 Oct 2020 00:54:26 -0700 From: Anand Jain To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.com, josef@toxicpanda.com Subject: [PATCH v2 2/4] btrfs: introduce new device-state read_preferred Date: Thu, 29 Oct 2020 15:54:09 +0800 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9788 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 phishscore=0 spamscore=0 bulkscore=0 malwarescore=0 mlxlogscore=999 mlxscore=0 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010290056 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9788 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 impostorscore=0 mlxlogscore=999 malwarescore=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 spamscore=0 phishscore=0 clxscore=1015 suspectscore=1 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010290055 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is a preparatory patch and introduces a new device flag 'read_preferred', RW-able using sysfs interface. Signed-off-by: Anand Jain --- v2: C style fixes. Drop space in between '! test_bit' and extra lines after it. fs/btrfs/sysfs.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.h | 1 + 2 files changed, 54 insertions(+) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 88cbf7b2edf0..35f4642a0468 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -1413,11 +1413,64 @@ static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj, } BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show); +static ssize_t btrfs_devinfo_read_pref_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + int val; + struct btrfs_device *device = container_of(kobj, struct btrfs_device, + devid_kobj); + + val = !!test_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state); + + return snprintf(buf, PAGE_SIZE, "%d\n", val); +} + +static ssize_t btrfs_devinfo_read_pref_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + int ret; + unsigned long val; + struct btrfs_device *device; + + ret = kstrtoul(skip_spaces(buf), 0, &val); + if (ret) + return ret; + + if (val != 0 && val != 1) + return -EINVAL; + + /* + * lock is not required, the btrfs_device struct can't be freed while + * its kobject btrfs_device::devid_kobj is still open. + */ + device = container_of(kobj, struct btrfs_device, devid_kobj); + + if (val && + !test_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state)) { + set_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state); + btrfs_info(device->fs_devices->fs_info, + "set read preferred on devid %llu (%d)", + device->devid, task_pid_nr(current)); + } else if (!val && + test_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state)) { + clear_bit(BTRFS_DEV_STATE_READ_PREFERRED, &device->dev_state); + btrfs_info(device->fs_devices->fs_info, + "reset read preferred on devid %llu (%d)", + device->devid, task_pid_nr(current)); + } + + return len; +} +BTRFS_ATTR_RW(devid, read_preferred, btrfs_devinfo_read_pref_show, + btrfs_devinfo_read_pref_store); + static struct attribute *devid_attrs[] = { BTRFS_ATTR_PTR(devid, in_fs_metadata), BTRFS_ATTR_PTR(devid, missing), BTRFS_ATTR_PTR(devid, replace_target), BTRFS_ATTR_PTR(devid, writeable), + BTRFS_ATTR_PTR(devid, read_preferred), NULL }; ATTRIBUTE_GROUPS(devid); diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 24db586a9837..f1cbbb18f5ef 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -51,6 +51,7 @@ struct btrfs_io_geometry { #define BTRFS_DEV_STATE_REPLACE_TGT (3) #define BTRFS_DEV_STATE_FLUSH_SENT (4) #define BTRFS_DEV_STATE_NO_READA (5) +#define BTRFS_DEV_STATE_READ_PREFERRED (6) struct btrfs_device { struct list_head dev_list; /* device_list_mutex */