From patchwork Sun Aug 28 06:46:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ojaswin Mujoo X-Patchwork-Id: 12957186 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 B9885ECAAD2 for ; Sun, 28 Aug 2022 06:47:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232949AbiH1Gq7 (ORCPT ); Sun, 28 Aug 2022 02:46:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232730AbiH1Gqw (ORCPT ); Sun, 28 Aug 2022 02:46:52 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E9DF4B0C2; Sat, 27 Aug 2022 23:46:51 -0700 (PDT) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27S594fa000407; Sun, 28 Aug 2022 06:46:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=gCCmfy8qvG0d0V1/cAfNdfT3acbWpIQUagPipop3hBo=; b=h3/VTj9RNU0GpVV4/E7GsHWiDe1zeVfDYQ7ssgI3z+pZefNAXHhwL1PkaZ+bQl84ImkS nhN0xeI0iTcu8bTFMaV5B2IoZoCkThHWGzHY18S+859GWLXqkfCfO4UDfU9Gl7W7tFQ0 u4VZGpcBlv1ykskim/k6H9jB3gVShulGxquoZ1th0+xtICPK/CrSa6WLQ7N8jEd/JvSk Xg+TvuU8uDw/t6C7Ze4Wg8pRGJXsq1ZPzMOVbbubG2xhhFfesbUKxM9DhXHVyBDJtE1N KuOpz0gaOjGmyW67y6ha9hDkvsUJcLtu1vjPSrXZSoQQP+ZOrRUMxkuMKyIC57Zd2XIH oQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3j7w6gg2cr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 28 Aug 2022 06:46:48 +0000 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 27S6kmJn030354; Sun, 28 Aug 2022 06:46:48 GMT Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3j7w6gg2c7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 28 Aug 2022 06:46:48 +0000 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 27S6Zuld012785; Sun, 28 Aug 2022 06:46:45 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma06fra.de.ibm.com with ESMTP id 3j7ahhrrdq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 28 Aug 2022 06:46:45 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 27S6l4vH44630502 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 28 Aug 2022 06:47:04 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4C3AC5204F; Sun, 28 Aug 2022 06:46:43 +0000 (GMT) Received: from li-bb2b2a4c-3307-11b2-a85c-8fa5c3a69313.ibm.com (unknown [9.43.118.96]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 3C6E05204E; Sun, 28 Aug 2022 06:46:41 +0000 (GMT) From: Ojaswin Mujoo To: linux-ext4@vger.kernel.org Cc: "Theodore Ts'o" , Ritesh Harjani , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Dilger , Ritesh Harjani Subject: [RFC 5/8] ext4: Abstract out overlap fix/check logic in ext4_mb_normalize_request() Date: Sun, 28 Aug 2022 12:16:18 +0530 Message-Id: <234312071f65ed3a66e9f3472082a745f575e50e.1661632343.git.ojaswin@linux.ibm.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: w_HlLSzDn5xFpW2c58xSqyVV2pcWOGJL X-Proofpoint-GUID: w9W8W0KuijcbBLGgAKEiztP19cd1vwMZ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-27_10,2022-08-25_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 suspectscore=0 phishscore=0 lowpriorityscore=0 priorityscore=1501 impostorscore=0 bulkscore=0 clxscore=1015 spamscore=0 mlxscore=0 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2208280025 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Abstract out the logic of fixing PA overlaps in ext4_mb_normalize_request to improve readability of code. This also makes it easier to make changes to the overlap logic in future. There are no functional changes in this patch Signed-off-by: Ojaswin Mujoo Reviewed-by: Ritesh Harjani (IBM) --- fs/ext4/mballoc.c | 110 +++++++++++++++++++++++++++++----------------- 1 file changed, 69 insertions(+), 41 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 8f5aaff892d4..49bc4b8fd849 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4043,6 +4043,74 @@ ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, rcu_read_unlock(); } +/* + * Given an allocation context "ac" and a range "start", "end", check + * and adjust boundaries if the range overlaps with any of the existing + * preallocatoins stored in the corresponding inode of the allocation context. + * + *Parameters: + * ac allocation context + * start start of the new range + * end end of the new range + */ +static inline void +ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, + ext4_lblk_t *start, ext4_lblk_t *end) +{ + struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); + struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); + struct ext4_prealloc_space *tmp_pa; + ext4_lblk_t new_start, new_end; + ext4_lblk_t tmp_pa_start, tmp_pa_end; + + new_start = *start; + new_end = *end; + + /* check we don't cross already preallocated blocks */ + rcu_read_lock(); + list_for_each_entry_rcu(tmp_pa, &ei->i_prealloc_list, pa_inode_list) { + if (tmp_pa->pa_deleted) + continue; + spin_lock(&tmp_pa->pa_lock); + if (tmp_pa->pa_deleted) { + spin_unlock(&tmp_pa->pa_lock); + continue; + } + + tmp_pa_start = tmp_pa->pa_lstart; + tmp_pa_end = tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); + + /* PA must not overlap original request */ + BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end || + ac->ac_o_ex.fe_logical < tmp_pa_start)); + + /* skip PAs this normalized request doesn't overlap with */ + if (tmp_pa_start >= new_end || tmp_pa_end <= new_start) { + spin_unlock(&tmp_pa->pa_lock); + continue; + } + BUG_ON(tmp_pa_start <= new_start && tmp_pa_end >= new_end); + + /* adjust start or end to be adjacent to this pa */ + if (tmp_pa_end <= ac->ac_o_ex.fe_logical) { + BUG_ON(tmp_pa_end < new_start); + new_start = tmp_pa_end; + } else if (tmp_pa_start > ac->ac_o_ex.fe_logical) { + BUG_ON(tmp_pa_start > new_end); + new_end = tmp_pa_start; + } + spin_unlock(&tmp_pa->pa_lock); + } + rcu_read_unlock(); + + /* XXX: extra loop to check we really don't overlap preallocations */ + ext4_mb_pa_assert_overlap(ac, new_start, new_end); + + *start = new_start; + *end = new_end; + return; +} + /* * Normalization means making request better in terms of * size and alignment @@ -4057,9 +4125,6 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, loff_t size, start_off; loff_t orig_size __maybe_unused; ext4_lblk_t start; - struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); - struct ext4_prealloc_space *tmp_pa; - ext4_lblk_t tmp_pa_start, tmp_pa_end; /* do normalize only data requests, metadata requests do not need preallocation */ @@ -4160,47 +4225,10 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, end = start + size; - /* check we don't cross already preallocated blocks */ - rcu_read_lock(); - list_for_each_entry_rcu(tmp_pa, &ei->i_prealloc_list, pa_inode_list) { - if (tmp_pa->pa_deleted) - continue; - spin_lock(&tmp_pa->pa_lock); - if (tmp_pa->pa_deleted) { - spin_unlock(&tmp_pa->pa_lock); - continue; - } - - tmp_pa_start = tmp_pa->pa_lstart; - tmp_pa_end = tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); - - /* PA must not overlap original request */ - BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end || - ac->ac_o_ex.fe_logical < tmp_pa_start)); - - /* skip PAs this normalized request doesn't overlap with */ - if (tmp_pa_start >= end || tmp_pa_end <= start) { - spin_unlock(&tmp_pa->pa_lock); - continue; - } - BUG_ON(tmp_pa_start <= start && tmp_pa_end >= end); + ext4_mb_pa_adjust_overlap(ac, &start, &end); - /* adjust start or end to be adjacent to this pa */ - if (tmp_pa_end <= ac->ac_o_ex.fe_logical) { - BUG_ON(tmp_pa_end < start); - start = tmp_pa_end; - } else if (tmp_pa_start > ac->ac_o_ex.fe_logical) { - BUG_ON(tmp_pa_start > end); - end = tmp_pa_start; - } - spin_unlock(&tmp_pa->pa_lock); - } - rcu_read_unlock(); size = end - start; - /* XXX: extra loop to check we really don't overlap preallocations */ - ext4_mb_pa_assert_overlap(ac, start, end); - /* * In this function "start" and "size" are normalized for better * alignment and length such that we could preallocate more blocks.