From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=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, URIBL_BLOCKED,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 0A5D2C35254 for ; Mon, 17 Feb 2020 11:13:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4F4720836 for ; Mon, 17 Feb 2020 11:13:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="mDStmlSw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728262AbgBQLNI (ORCPT ); Mon, 17 Feb 2020 06:13:08 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:52510 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726823AbgBQLNH (ORCPT ); Mon, 17 Feb 2020 06:13:07 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01HB3nCl016652; Mon, 17 Feb 2020 11:13:03 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; s=corp-2020-01-29; bh=cFFXCnj1TRI/srMbEsfjx/ptP6483/G2MBBt06FE14c=; b=mDStmlSwf3wqrf8M7C6l7t+sJw94r68ieo90DlUuyrCdvenLNjLvayKzhXjthamjZmCY S+bVh4dLM4+wpDLDU+CYZe4QWNgxgSKRtaZO9RrhXt3TgAcoT3IcQjg2gBmAI52ULEqI uDFM1oAkVKW/Db68OIz4Z1NFhnl5xZDEaclWoohO0pREnuWLs+LXA5rSI8qYgoUgAG1U EHHKKRK7eBA5lgBOBMGAKLDeXfHIHcg/QipAzeuzv0xKO8wKEgHQQGZz6PIpNLMx2uTI gmCeT5gf2Rv+GdVmvdC6I72oqK660HBJ4jh1aJ3+C8tzIkC8MBYvzgQIUZR5lcsp/7rK ag== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 2y699rfhfs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 17 Feb 2020 11:13:03 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01HBC43V101911; Mon, 17 Feb 2020 11:13:02 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 2y6teheyfe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 17 Feb 2020 11:13:02 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 01HBD1IL027548; Mon, 17 Feb 2020 11:13:01 GMT Received: from tp.localdomain (/39.109.145.141) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 17 Feb 2020 03:13:01 -0800 From: Anand Jain To: linux-btrfs@vger.kernel.org Cc: josef@toxicpanda.com, dsterba@suse.com Subject: [PATCH v5 3/5] btrfs: create read policy sysfs attribute, pid Date: Mon, 17 Feb 2020 19:12:43 +0800 Message-Id: <1581937965-16569-4-git-send-email-anand.jain@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1581937965-16569-1-git-send-email-anand.jain@oracle.com> References: <1581937965-16569-1-git-send-email-anand.jain@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9533 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 phishscore=0 bulkscore=0 suspectscore=1 mlxscore=0 mlxlogscore=999 adultscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002170097 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9533 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 suspectscore=1 malwarescore=0 priorityscore=1501 adultscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 lowpriorityscore=0 spamscore=0 clxscore=1015 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002170096 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Add /sys/fs/btrfs/UUID/read_policy attribute so that the read policy for the raid1 and raid10 chunks can be tuned. When this attribute is read, it shall show all available policies, with active policy being with in [ ]. The read_policy attribute can be written using one of the items listed in there. For example: $cat /sys/fs/btrfs/UUID/read_policy [pid] $echo pid > /sys/fs/btrfs/UUID/read_policy Signed-off-by: Anand Jain Reviewed-by: Josef Bacik --- v5: Title rename: old: btrfs: sysfs, add read_policy attribute Uses the btrfs_strmatch() helper (BTRFS_READ_POLICY_NAME_MAX dropped). Use the table for the policy names. Rename len to ret. Use a simple logic to prefix space in btrfs_read_policy_show() v4:- v3: rename [by_pid] to [pid] v2: v2: check input len before strip and kstrdup fs/btrfs/sysfs.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 7bb68cef98ab..c9a8850b186a 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -832,6 +832,54 @@ static int btrfs_strmatch(const char *given, const char *golden) return -EINVAL; } +static const char* const btrfs_read_policy_name[] = { "pid" }; + +static ssize_t btrfs_read_policy_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + int i; + ssize_t ret = 0; + struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj); + + for (i = 0; i < BTRFS_NR_READ_POLICY; i++) { + if (fs_devices->read_policy == i) + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]", + (ret == 0 ? "" : " "), + btrfs_read_policy_name[i]); + else + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s", + (ret == 0 ? "" : " "), + btrfs_read_policy_name[i]); + } + + ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n"); + + return ret; +} + +static ssize_t btrfs_read_policy_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + int i; + struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj); + + for (i = 0; i < BTRFS_NR_READ_POLICY; i++) { + if (btrfs_strmatch(buf, btrfs_read_policy_name[i]) == 0) { + if (i != fs_devices->read_policy) { + fs_devices->read_policy = i; + btrfs_info(fs_devices->fs_info, + "read policy set to '%s'", + btrfs_read_policy_name[i]); + } + return len; + } + } + + return -EINVAL; +} +BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store); + static const struct attribute *btrfs_attrs[] = { BTRFS_ATTR_PTR(, label), BTRFS_ATTR_PTR(, nodesize), @@ -840,6 +888,7 @@ static int btrfs_strmatch(const char *given, const char *golden) BTRFS_ATTR_PTR(, quota_override), BTRFS_ATTR_PTR(, metadata_uuid), BTRFS_ATTR_PTR(, checksum), + BTRFS_ATTR_PTR(, read_policy), NULL, }; -- 1.8.3.1