From patchwork Wed Oct 28 08:10:25 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandan Rajendra X-Patchwork-Id: 7508201 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6524D9F2F7 for ; Wed, 28 Oct 2015 08:11:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 85043205E5 for ; Wed, 28 Oct 2015 08:11:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D624205CA for ; Wed, 28 Oct 2015 08:11:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755717AbbJ1ILc (ORCPT ); Wed, 28 Oct 2015 04:11:32 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:49208 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755164AbbJ1IKp (ORCPT ); Wed, 28 Oct 2015 04:10:45 -0400 Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 28 Oct 2015 13:40:40 +0530 X-Helo: d28dlp02.in.ibm.com X-MailFrom: chandan@linux.vnet.ibm.com X-RcptTo: linux-btrfs@vger.kernel.org Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 46C9B3940019 for ; Wed, 28 Oct 2015 13:40:40 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay03.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t9S8Ae7J66978028 for ; Wed, 28 Oct 2015 13:40:40 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t9S8AbRq003579 for ; Wed, 28 Oct 2015 13:40:38 +0530 Received: from localhost.in.ibm.com ([9.124.35.170]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id t9S8AZk7003373; Wed, 28 Oct 2015 13:40:37 +0530 From: Chandan Rajendra To: linux-btrfs@vger.kernel.org Cc: Chandan Rajendra , clm@fb.com, jbacik@fb.com, bo.li.liu@oracle.com, dsterba@suse.cz, quwenruo@cn.fujitsu.com, chandan@mykolab.com Subject: [PATCH V8 11/13] Btrfs: Clean pte corresponding to page straddling i_size Date: Wed, 28 Oct 2015 13:40:25 +0530 Message-Id: <1446019827-685-12-git-send-email-chandan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1446019827-685-1-git-send-email-chandan@linux.vnet.ibm.com> References: <1446019827-685-1-git-send-email-chandan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15102808-0029-0000-0000-000008DED3D9 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When extending a file by either "truncate up" or by writing beyond i_size, the page which had i_size needs to be marked "read only" so that future writes to the page via mmap interface causes btrfs_page_mkwrite() to be invoked. If not, a write performed after extending the file via the mmap interface will find the page to be writaeable and continue writing to the page without invoking btrfs_page_mkwrite() i.e. we end up writing to a file without reserving disk space. Signed-off-by: Chandan Rajendra --- fs/btrfs/file.c | 12 ++++++++++-- fs/btrfs/inode.c | 2 +- 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 81df4fa..5a7551c 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1757,6 +1757,8 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, ssize_t err; loff_t pos; size_t count; + loff_t oldsize; + int clean_page = 0; mutex_lock(&inode->i_mutex); err = generic_write_checks(iocb, from); @@ -1795,14 +1797,17 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, pos = iocb->ki_pos; count = iov_iter_count(from); start_pos = round_down(pos, root->sectorsize); - if (start_pos > i_size_read(inode)) { + oldsize = i_size_read(inode); + if (start_pos > oldsize) { /* Expand hole size to cover write data, preventing empty gap */ end_pos = round_up(pos + count, root->sectorsize); - err = btrfs_cont_expand(inode, i_size_read(inode), end_pos); + err = btrfs_cont_expand(inode, oldsize, end_pos); if (err) { mutex_unlock(&inode->i_mutex); goto out; } + if (start_pos > round_up(oldsize, root->sectorsize)) + clean_page = 1; } if (sync) @@ -1814,6 +1819,9 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, num_written = __btrfs_buffered_write(file, from, pos); if (num_written > 0) iocb->ki_pos = pos + num_written; + if (clean_page) + pagecache_isize_extended(inode, oldsize, + i_size_read(inode)); } mutex_unlock(&inode->i_mutex); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index af24f8c..38149f4 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4943,7 +4943,6 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) } if (newsize > oldsize) { - truncate_pagecache(inode, newsize); /* * Don't do an expanding truncate while snapshoting is ongoing. * This is to ensure the snapshot captures a fully consistent @@ -4966,6 +4965,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) i_size_write(inode, newsize); btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); + pagecache_isize_extended(inode, oldsize, newsize); ret = btrfs_update_inode(trans, root, inode); btrfs_end_write_no_snapshoting(root); btrfs_end_transaction(trans, root);