From patchwork Wed Aug 19 10:28:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anju T Sudhakar X-Patchwork-Id: 11723451 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 406E0618 for ; Wed, 19 Aug 2020 10:29:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1944C207FB for ; Wed, 19 Aug 2020 10:29:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="lRjpuSCp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726970AbgHSK3D (ORCPT ); Wed, 19 Aug 2020 06:29:03 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:18594 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726642AbgHSK3A (ORCPT ); Wed, 19 Aug 2020 06:29:00 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07JA1a06146945; Wed, 19 Aug 2020 06:28:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=vAVx19PN5evAuL1yft8QctVm3MEbjgVTzM0AEmd3lu8=; b=lRjpuSCp10DoMysfqOcmcU5aufeygLjPEgxdiJ8jV5YUS4CgcCkxwzVaSaLD/9UtEnnI VDpJ73Npda2qV4zp9hHT+04djr14hFHB42sM+CPXjCfPc77mOSMf7ueX6Xuj5EBr6ZTP YCoJhjDzDVdaNSgbfYnKc2JSjqDCPiU89jnjxWTf/5WKD6MiebeDLiBgSXXKbbm0qljL DK9gnm6nA8LHUxfSTUtGTYOUtQa18Xm6jY3W3+0HLPMj8M1yTkZWwdTetIEnz2Xh/Bp0 MNmUhiz19X5EGHEvAgZzmtjGCg/MTf6xzWEqtHmikvYkSeLRDKkZxP1yAYXq7w0rDMpN pg== Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 3304ru5fny-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 19 Aug 2020 06:28:51 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 07JAPIms005141; Wed, 19 Aug 2020 10:28:49 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma03ams.nl.ibm.com with ESMTP id 3304um1q59-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 19 Aug 2020 10:28:49 +0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 07JASkkB21365094 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 Aug 2020 10:28:46 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B0BBA42064; Wed, 19 Aug 2020 10:28:46 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0409242041; Wed, 19 Aug 2020 10:28:45 +0000 (GMT) Received: from localhost.localdomain.com (unknown [9.85.116.28]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 19 Aug 2020 10:28:44 +0000 (GMT) From: Anju T Sudhakar To: hch@infradead.org, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, willy@infradead.org, riteshh@linux.ibm.com, anju@linux.vnet.ibm.com Subject: [PATCH] iomap: Fix the write_count in iomap_add_to_ioend(). Date: Wed, 19 Aug 2020 15:58:41 +0530 Message-Id: <20200819102841.481461-1-anju@linux.vnet.ibm.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-19_04:2020-08-19,2020-08-19 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxlogscore=708 priorityscore=1501 suspectscore=0 phishscore=0 spamscore=0 impostorscore=0 adultscore=0 mlxscore=0 clxscore=1011 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008190082 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Ritesh Harjani __bio_try_merge_page() may return same_page = 1 and merged = 0. This could happen when bio->bi_iter.bi_size + len > UINT_MAX. Handle this case in iomap_add_to_ioend() by incrementing write_count. This scenario mostly happens where we have too much dirty data accumulated. w/o the patch we hit below kernel warning, WARNING: CPU: 18 PID: 5130 at fs/iomap/buffered-io.c:74 iomap_page_release+0x120/0x150 CPU: 18 PID: 5130 Comm: fio Kdump: loaded Tainted: G W 5.8.0-rc3 #6 Call Trace: __remove_mapping+0x154/0x320 (unreliable) iomap_releasepage+0x80/0x180 try_to_release_page+0x94/0xe0 invalidate_inode_page+0xc8/0x110 invalidate_mapping_pages+0x1dc/0x540 generic_fadvise+0x3c8/0x450 xfs_file_fadvise+0x2c/0xe0 [xfs] vfs_fadvise+0x3c/0x60 ksys_fadvise64_64+0x68/0xe0 sys_fadvise64+0x28/0x40 system_call_exception+0xf8/0x1c0 system_call_common+0xf0/0x278 Reported-by: Shivaprasad G Bhat Signed-off-by: Ritesh Harjani Signed-off-by: Anju T Sudhakar --- fs/iomap/buffered-io.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index bcfc288dba3f..4e8062279e66 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1332,10 +1332,12 @@ iomap_add_to_ioend(struct inode *inode, loff_t offset, struct page *page, merged = __bio_try_merge_page(wpc->ioend->io_bio, page, len, poff, &same_page); - if (iop && !same_page) + if (iop && merged && !same_page) atomic_inc(&iop->write_count); if (!merged) { + if (iop) + atomic_inc(&iop->write_count); if (bio_full(wpc->ioend->io_bio, len)) { wpc->ioend->io_bio = iomap_chain_bio(wpc->ioend->io_bio);