From patchwork Sat Sep 5 12:12:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mikulas Patocka X-Patchwork-Id: 11759035 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 0690913B1 for ; Sat, 5 Sep 2020 12:12:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A421720757 for ; Sat, 5 Sep 2020 12:12:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="O+p11ljy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A421720757 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CC8E76B0037; Sat, 5 Sep 2020 08:12:13 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id C9DEB6B0055; Sat, 5 Sep 2020 08:12:13 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BB61A6B005A; Sat, 5 Sep 2020 08:12:13 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0056.hostedemail.com [216.40.44.56]) by kanga.kvack.org (Postfix) with ESMTP id A11666B0037 for ; Sat, 5 Sep 2020 08:12:13 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 64885362D for ; Sat, 5 Sep 2020 12:12:13 +0000 (UTC) X-FDA: 77228894946.15.net61_2d06979270ba Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id 35D721814B0C1 for ; Sat, 5 Sep 2020 12:12:13 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,mpatocka@redhat.com,,RULES_HIT:30051:30054:30070:30090,0,RBL:205.139.110.120:@redhat.com:.lbl8.mailshell.net-62.18.0.100 66.10.201.10;04ygmuqajjosc85ecbi1c4i46otdgopneces3zg8kgu786n7ioexdjnoghntrko.drbwo6amhzuzg3qhup8u4n4akczffahurjreuu1gcygwxstc5bgzzyxw1m3yt5z.a-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: net61_2d06979270ba X-Filterd-Recvd-Size: 5370 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Sat, 5 Sep 2020 12:12:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599307932; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=qJZq+Utr2MNF3iSeTd5whZpczkdnhNmjJK+ZipavdxI=; b=O+p11ljyC84KgFJuqGCJ7x2WiO6VDUM25r9o/4sLWs66fIbsc4baxBBqyFXKkuPAjJJR/Z mgJlFwBjj6cZZqL7gfxEiSeuCkC/nf4D0E0p8vYEC4sUjyH4OYfvIVyUb0mZVAVW+Hx0vk No0L1nEmfLu/EmF5Mq3lPEAPnrCTsHQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-496-wmpBuOf2PGeDWX7-G1ZQ0g-1; Sat, 05 Sep 2020 08:12:07 -0400 X-MC-Unique: wmpBuOf2PGeDWX7-G1ZQ0g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6BE0B1074643; Sat, 5 Sep 2020 12:12:05 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4CF9F7ED86; Sat, 5 Sep 2020 12:12:02 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id 085CC1XE012789; Sat, 5 Sep 2020 08:12:01 -0400 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id 085CC19D012786; Sat, 5 Sep 2020 08:12:01 -0400 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Sat, 5 Sep 2020 08:12:01 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Linus Torvalds , Jan Kara , "Darrick J. Wong" , Dave Chinner cc: Jann Horn , Christoph Hellwig , Oleg Nesterov , Kirill Shutemov , "Theodore Ts'o" , Andrea Arcangeli , Matthew Wilcox , Andrew Morton , Dan Williams , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH 1/2] ext2: don't update mtime on COW faults In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Rspamd-Queue-Id: 35D721814B0C1 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When running in a dax mode, if the user maps a page with MAP_PRIVATE and PROT_WRITE, the ext2 filesystem would incorrectly update ctime and mtime when the user hits a COW fault. This breaks building of the Linux kernel. How to reproduce: 1. extract the Linux kernel tree on dax-mounted ext2 filesystem 2. run make clean 3. run make -j12 4. run make -j12 - at step 4, make would incorrectly rebuild the whole kernel (although it was already built in step 3). The reason for the breakage is that almost all object files depend on objtool. When we run objtool, it takes COW page fault on its .data section, and these faults will incorrectly update the timestamp of the objtool binary. The updated timestamp causes make to rebuild the whole tree. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org --- fs/ext2/file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Index: linux-2.6/fs/ext2/file.c =================================================================== --- linux-2.6.orig/fs/ext2/file.c 2020-09-05 10:01:41.000000000 +0200 +++ linux-2.6/fs/ext2/file.c 2020-09-05 13:09:50.000000000 +0200 @@ -93,8 +93,10 @@ static vm_fault_t ext2_dax_fault(struct struct inode *inode = file_inode(vmf->vma->vm_file); struct ext2_inode_info *ei = EXT2_I(inode); vm_fault_t ret; + bool write = (vmf->flags & FAULT_FLAG_WRITE) && + (vmf->vma->vm_flags & VM_SHARED); - if (vmf->flags & FAULT_FLAG_WRITE) { + if (write) { sb_start_pagefault(inode->i_sb); file_update_time(vmf->vma->vm_file); } @@ -103,7 +105,7 @@ static vm_fault_t ext2_dax_fault(struct ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops); up_read(&ei->dax_sem); - if (vmf->flags & FAULT_FLAG_WRITE) + if (write) sb_end_pagefault(inode->i_sb); return ret; } From patchwork Sat Sep 5 12:13:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mikulas Patocka X-Patchwork-Id: 11759041 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 3E610618 for ; Sat, 5 Sep 2020 12:13:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D4E1520796 for ; Sat, 5 Sep 2020 12:13:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g4nUQhhl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D4E1520796 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 104496B0003; 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Sat, 5 Sep 2020 08:13:02 -0400 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id 085CD2uR012810; Sat, 5 Sep 2020 08:13:02 -0400 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Sat, 5 Sep 2020 08:13:02 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Linus Torvalds , Jan Kara , "Darrick J. Wong" , Dave Chinner cc: Jann Horn , Christoph Hellwig , Oleg Nesterov , Kirill Shutemov , "Theodore Ts'o" , Andrea Arcangeli , Matthew Wilcox , Andrew Morton , Dan Williams , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH 2/2] xfs: don't update mtime on COW faults In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Rspamd-Queue-Id: 6BE9C16A07F X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When running in a dax mode, if the user maps a page with MAP_PRIVATE and PROT_WRITE, the xfs filesystem would incorrectly update ctime and mtime when the user hits a COW fault. This breaks building of the Linux kernel. How to reproduce: 1. extract the Linux kernel tree on dax-mounted xfs filesystem 2. run make clean 3. run make -j12 4. run make -j12 - at step 4, make would incorrectly rebuild the whole kernel (although it was already built in step 3). The reason for the breakage is that almost all object files depend on objtool. When we run objtool, it takes COW page fault on its .data section, and these faults will incorrectly update the timestamp of the objtool binary. The updated timestamp causes make to rebuild the whole tree. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka --- fs/xfs/xfs_file.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) Index: linux-2.6/fs/xfs/xfs_file.c =================================================================== --- linux-2.6.orig/fs/xfs/xfs_file.c 2020-09-05 10:01:42.000000000 +0200 +++ linux-2.6/fs/xfs/xfs_file.c 2020-09-05 13:59:12.000000000 +0200 @@ -1223,6 +1223,13 @@ __xfs_filemap_fault( return ret; } +static bool +xfs_is_write_fault( + struct vm_fault *vmf) +{ + return vmf->flags & FAULT_FLAG_WRITE && vmf->vma->vm_flags & VM_SHARED; +} + static vm_fault_t xfs_filemap_fault( struct vm_fault *vmf) @@ -1230,7 +1237,7 @@ xfs_filemap_fault( /* DAX can shortcut the normal fault path on write faults! */ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, IS_DAX(file_inode(vmf->vma->vm_file)) && - (vmf->flags & FAULT_FLAG_WRITE)); + xfs_is_write_fault(vmf)); } static vm_fault_t @@ -1243,7 +1250,7 @@ xfs_filemap_huge_fault( /* DAX can shortcut the normal fault path on write faults! */ return __xfs_filemap_fault(vmf, pe_size, - (vmf->flags & FAULT_FLAG_WRITE)); + xfs_is_write_fault(vmf)); } static vm_fault_t