From nobody Fri Feb 13 06:42:04 2026 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 0FECAE71D42 for ; Fri, 29 Sep 2023 14:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233160AbjI2OLP (ORCPT ); Fri, 29 Sep 2023 10:11:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233149AbjI2OLJ (ORCPT ); Fri, 29 Sep 2023 10:11:09 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D61931B2; Fri, 29 Sep 2023 07:11:05 -0700 (PDT) Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 38TE9vFa031221; Fri, 29 Sep 2023 14:11:00 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=/MJo3EBySglF0dpjswUzhDX1+E3ul8XFL5YMWvHDjOE=; b=ClyEUSukJLtC8MQucAef2XrzV2fJ8q+8J5uJPcHkN16d9LRJA6fIi137AkPzXT/bMl5w KCWBtCWUE3xJoBUAX5SUXFj8fyjO1n622C1IH/+nO4O+YozI2C24Zton7ywUOt8X6V1W tubiPsytmqZlQGcLCMIfmi79CWWeflaPUL4yF0uLh/G0CaBb9DDPdLWOLvtLQdB75jKn zWgZpNtFpI1lvMd29/eRNkEK9N5xEhy9gW80/rdRLm+ArQltVKpf8VQAA8hlj+1Gw+t5 KskR0fi12+LdWRyiE6AchhcY9DfC7db+T/yO93DNwDBLmVRiP+y68O+hty5kNSx8zQlx fA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3tdw5uvyp2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 29 Sep 2023 14:10:59 +0000 Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 38TEAxuN003610; Fri, 29 Sep 2023 14:10:59 GMT Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3tdw5uvynp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 29 Sep 2023 14:10:59 +0000 Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 38TCOnKK008234; Fri, 29 Sep 2023 14:10:58 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 3tabbnw47r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 29 Sep 2023 14:10:58 +0000 Received: from smtpav07.fra02v.mail.ibm.com (smtpav07.fra02v.mail.ibm.com [10.20.54.106]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 38TEAutc19399208 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 29 Sep 2023 14:10:56 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 596D42004B; Fri, 29 Sep 2023 14:10:56 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C46E320040; Fri, 29 Sep 2023 14:10:54 +0000 (GMT) Received: from li-bb2b2a4c-3307-11b2-a85c-8fa5c3a69313.ibm.com.com (unknown [9.43.84.228]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTP; Fri, 29 Sep 2023 14:10:54 +0000 (GMT) From: Ojaswin Mujoo To: linux-ext4@vger.kernel.org, "Theodore Ts'o" Cc: Ritesh Harjani , linux-kernel@vger.kernel.org, Jan Kara Subject: [PATCH 3/3] ext4: Skip unwritten buffers in __ext4_block_zero_page_range() Date: Fri, 29 Sep 2023 19:40:45 +0530 Message-Id: <143d41362a57e453f5a2cb00dc71e38e020c1c20.1695987265.git.ojaswin@linux.ibm.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 3cq2_C6yRHtd3NCt_JcnXW6tzwBTPs7a X-Proofpoint-ORIG-GUID: tlX1vHivoJaFdXqACsLF9u4Od2_qYlOg X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-09-29_11,2023-09-28_03,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 lowpriorityscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 mlxscore=0 bulkscore=0 impostorscore=0 clxscore=1015 adultscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2309290120 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If the buffer is unwritten then the underlying block should already return = zero for reads. Further, if it is not dirty then we can be sure that there is no= data on the folio that might get written back later. Hence we skip zeroing out t= he folio and underlying block in this case. Suggested-by: Jan Kara Signed-off-by: Ojaswin Mujoo --- fs/ext4/inode.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index de8ea8430d30..75a951ffa3cb 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3659,6 +3659,10 @@ static int __ext4_block_zero_page_range(handle_t *ha= ndle, BUFFER_TRACE(bh, "freed: skip"); goto unlock; } + if (buffer_unwritten(bh) && !buffer_dirty(bh)) { + BUFFER_TRACE(bh, "unwritten and non-dirty: skip"); + goto unlock; + } if (!buffer_mapped(bh)) { BUFFER_TRACE(bh, "unmapped"); ext4_get_block(inode, iblock, bh, 0); --=20 2.39.3