From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45E9BC33CA1 for ; Thu, 9 Jan 2020 13:35:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E7A52077C for ; Thu, 9 Jan 2020 13:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578576906; bh=B5yzemeRMvzL4pKKGwpH7BIBwVJZXFC+F4JbFhOpfek=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=SeHnsTwSO1aRfQ01LA4qVECQAIu4Bcbu2T9QF1Qyyx6mdHBKTD7VWdhu+OemdYg3Z oVwa/rnJ5u2q/zBdB/yuxPFgb7XDNg5XXtL9+Yh0MPPb9dB91YkgAqcdZ92ALGUeQb peZB8kA7iD6HfCaRZ1Y5bmsrU32P54GCp9GDsXcI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730542AbgAINfA (ORCPT ); Thu, 9 Jan 2020 08:35:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:34354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728974AbgAINfA (ORCPT ); Thu, 9 Jan 2020 08:35:00 -0500 Received: from tleilax.poochiereds.net (68-20-15-154.lightspeed.rlghnc.sbcglobal.net [68.20.15.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0E05F20661; Thu, 9 Jan 2020 13:34:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578576899; bh=B5yzemeRMvzL4pKKGwpH7BIBwVJZXFC+F4JbFhOpfek=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=FP854yG1iF6PZ3f6ByuN1p2Ck1GBxOzQ7bJVht0FIaYDlv1ZpMklxdzoRLjXc24xu yLKaBtnOxLxgrrHRlvX1FPMkTu5c2imI1AWkgiKt56QokkSQZHzV5fJTLYZBVp6zDp o7s2RWwZqfybKsBicS2CNXr6XgOrIP1D8y9ov0kg= Message-ID: <03e0e79fefcd9e7985a5defce5d5833d3175847a.camel@kernel.org> Subject: Re: [PATCH v4] fs: Fix page_mkwrite off-by-one errors From: Jeff Layton To: Andreas Gruenbacher , "Darrick J. Wong" Cc: Alexander Viro , Christoph Hellwig , Linus Torvalds , linux-kernel@vger.kernel.org, Sage Weil , Ilya Dryomov , Theodore Ts'o , Andreas Dilger , Jaegeuk Kim , Chao Yu , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Richard Weinberger , Artem Bityutskiy , Adrian Hunter , ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, Jan Kara , YueHaibing , Arnd Bergmann , Chao Yu Date: Thu, 09 Jan 2020 08:34:56 -0500 In-Reply-To: <20200108131528.4279-1-agruenba@redhat.com> References: <20200108131528.4279-1-agruenba@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.2 (3.34.2-1.fc31) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, 2020-01-08 at 14:15 +0100, Andreas Gruenbacher wrote: > Hi Darrick, > > here's an updated version with the latest feedback incorporated. Hope > you find that useful. > > As far as the f2fs merge conflict goes, I've been told by Linus not to > resolve those kinds of conflicts but to point them out when sending the > merge request. So this shouldn't be a big deal. > > Changes: > > * Turn page_mkwrite_check_truncate into a non-inline function. > * Get rid of now-unused mapping variable in ext4_page_mkwrite. > * In btrfs_page_mkwrite, don't ignore the return value of > block_page_mkwrite_return (no change in behavior). > * Clean up the f2fs_vm_page_mkwrite changes as suggested by > Jaegeuk Kim. > > Thanks, > Andreas > > -- > > The check in block_page_mkwrite that is meant to determine whether an > offset is within the inode size is off by one. This bug has been copied > into iomap_page_mkwrite and several filesystems (ubifs, ext4, f2fs, > ceph). > > Fix that by introducing a new page_mkwrite_check_truncate helper that > checks for truncate and computes the bytes in the page up to EOF. Use > the helper in the above mentioned filesystems. > > In addition, use the new helper in btrfs as well. > > Signed-off-by: Andreas Gruenbacher > Acked-by: David Sterba (btrfs) > Acked-by: Richard Weinberger (ubifs) > Acked-by: Theodore Ts'o (ext4) > Acked-by: Chao Yu (f2fs) > --- > fs/btrfs/inode.c | 16 +++++----------- > fs/buffer.c | 16 +++------------- > fs/ceph/addr.c | 2 +- > fs/ext4/inode.c | 15 ++++----------- > fs/f2fs/file.c | 19 +++++++------------ > fs/iomap/buffered-io.c | 18 +++++------------- > fs/ubifs/file.c | 3 +-- > include/linux/pagemap.h | 2 ++ > mm/filemap.c | 28 ++++++++++++++++++++++++++++ > 9 files changed, 56 insertions(+), 63 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index e3c76645cad7..23e6f614e000 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -9011,16 +9011,15 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) > goto out_noreserve; > } > > - ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ > again: > lock_page(page); > - size = i_size_read(inode); > > - if ((page->mapping != inode->i_mapping) || > - (page_start >= size)) { > - /* page got truncated out from underneath us */ > + ret2 = page_mkwrite_check_truncate(page, inode); > + if (ret2 < 0) { > + ret = block_page_mkwrite_return(ret2); > goto out_unlock; > } > + zero_start = ret2; > wait_on_page_writeback(page); > > lock_extent_bits(io_tree, page_start, page_end, &cached_state); > @@ -9041,6 +9040,7 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) > goto again; > } > > + size = i_size_read(inode); > if (page->index == ((size - 1) >> PAGE_SHIFT)) { > reserved_space = round_up(size - page_start, > fs_info->sectorsize); > @@ -9073,12 +9073,6 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) > } > ret2 = 0; > > - /* page is wholly or partially inside EOF */ > - if (page_start + PAGE_SIZE > size) > - zero_start = offset_in_page(size); > - else > - zero_start = PAGE_SIZE; > - > if (zero_start != PAGE_SIZE) { > kaddr = kmap(page); > memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start); > diff --git a/fs/buffer.c b/fs/buffer.c > index d8c7242426bb..53aabde57ca7 100644 > --- a/fs/buffer.c > +++ b/fs/buffer.c > @@ -2499,23 +2499,13 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, > struct page *page = vmf->page; > struct inode *inode = file_inode(vma->vm_file); > unsigned long end; > - loff_t size; > int ret; > > lock_page(page); > - size = i_size_read(inode); > - if ((page->mapping != inode->i_mapping) || > - (page_offset(page) > size)) { > - /* We overload EFAULT to mean page got truncated */ > - ret = -EFAULT; > + ret = page_mkwrite_check_truncate(page, inode); > + if (ret < 0) > goto out_unlock; > - } > - > - /* page is wholly or partially inside EOF */ > - if (((page->index + 1) << PAGE_SHIFT) > size) > - end = size & ~PAGE_MASK; > - else > - end = PAGE_SIZE; > + end = ret; > > ret = __block_write_begin(page, 0, end, get_block); > if (!ret) > diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c > index 7ab616601141..ef958aa4adb4 100644 > --- a/fs/ceph/addr.c > +++ b/fs/ceph/addr.c > @@ -1575,7 +1575,7 @@ static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf) > do { > lock_page(page); > > - if ((off > size) || (page->mapping != inode->i_mapping)) { > + if (page_mkwrite_check_truncate(page, inode) < 0) { > unlock_page(page); > ret = VM_FAULT_NOPAGE; > break; You can add my Acked-by on the ceph part. -- Jeff Layton