From patchwork Mon Mar 20 04:54:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Calvin Owens X-Patchwork-Id: 9633037 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9A16D60132 for ; Mon, 20 Mar 2017 04:57:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7CD1827FAC for ; Mon, 20 Mar 2017 04:57:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5F40D2810E; Mon, 20 Mar 2017 04:57:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 97D7727FAC for ; Mon, 20 Mar 2017 04:57:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751255AbdCTE5c (ORCPT ); Mon, 20 Mar 2017 00:57:32 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:47641 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751027AbdCTE5c (ORCPT ); Mon, 20 Mar 2017 00:57:32 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2K4oIMc006278 for ; Sun, 19 Mar 2017 21:54:56 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=3euoisHChHuOYbwPvTCQ2bHHjeD/TNl6XnIAN7lNJYA=; b=M23vQLmvgDBn1GeGB3/GhnuTzsOoD41fcXh9rN0H3jiIvhMIZKfrITlL1zp7vZbfnOAQ So5Yd36Myt6OhTA+ih71sxrBekaYPYBB1Lf/V579kpAGFxWwHrMReOf9EdTaZjAnthwY BKNaYPqvpVf+IOXBw88zYsUjnSN0PdwmU/s= Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 299tbx1nf5-2 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sun, 19 Mar 2017 21:54:56 -0700 Received: from mx-out.facebook.com (192.168.52.123) by PRN-CHUB09.TheFacebook.com (192.168.16.19) with Microsoft SMTP Server (TLS) id 14.3.319.2; Sun, 19 Mar 2017 21:54:54 -0700 Received: from facebook.com (2401:db00:11:d0be:face:0:1b:0) by mx-out.facebook.com (10.223.100.99) with ESMTP id 5b0cda9e0d2911e7a0eb24be05956610-bb3fc9a0 for ; Sun, 19 Mar 2017 21:54:53 -0700 Received: by devbig337.prn1.facebook.com (Postfix, from userid 10532) id 27BE7480EA1; Sun, 19 Mar 2017 21:54:52 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Calvin Owens Smtp-Origin-Hostname: devbig337.prn1.facebook.com To: "Darrick J. Wong" CC: , , Christoph Hellwig , Dave Chinner , , , Smtp-Origin-Cluster: prn1c29 Subject: [PATCH v2] xfs: Honor FALLOC_FL_KEEP_SIZE when punching ends of files Date: Sun, 19 Mar 2017 21:54:51 -0700 Message-ID: <19504ff40a16efff2e51d85388fce5be578edbc3.1489985397.git.calvinowens@fb.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <22a11e65fd5037498a78de61f3ed4dae466ad854.1489791330.git.calvinowens@fb.com> References: <22a11e65fd5037498a78de61f3ed4dae466ad854.1489791330.git.calvinowens@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-03-20_03:, , signatures=0 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When punching past EOF on XFS, fallocate(mode=PUNCH_HOLE|KEEP_SIZE) will round the file size up to the nearest multiple of PAGE_SIZE: calvinow@vm-disks/generic-xfs-1 ~$ dd if=/dev/urandom of=test bs=2048 count=1 calvinow@vm-disks/generic-xfs-1 ~$ stat test Size: 2048 Blocks: 8 IO Block: 4096 regular file calvinow@vm-disks/generic-xfs-1 ~$ fallocate -n -l 2048 -o 2048 -p test calvinow@vm-disks/generic-xfs-1 ~$ stat test Size: 4096 Blocks: 8 IO Block: 4096 regular file Commit 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes") replaced xfs_zero_remaining_bytes() with calls to iomap helpers. The new helpers don't enforce that [pos,offset) lies strictly on [0,i_size) when being called from xfs_free_file_space(), so by "leaking" these ranges into xfs_zero_range() we get this buggy behavior. Fix this by reintroducing the checks xfs_zero_remaining_bytes() did against i_size at the bottom of xfs_free_file_space(). Reported-by: Aaron Gao Fixes: 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes") Cc: Christoph Hellwig Cc: # 4.8+ Signed-off-by: Calvin Owens --- fs/xfs/xfs_bmap_util.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 8b75dce..0796ebc 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1309,6 +1309,17 @@ xfs_free_file_space( } /* + * Avoid doing I/O beyond eof - it's not necessary + * since nothing can read beyond eof. The space will + * be zeroed when the file is extended anyway. + */ + if (offset >= XFS_ISIZE(ip)) + return 0; + + if ((offset + len) >= XFS_ISIZE(ip)) + len = XFS_ISIZE(ip) - offset - 1; + + /* * Now that we've unmap all full blocks we'll have to zero out any * partial block at the beginning and/or end. xfs_zero_range is * smart enough to skip any holes, including those we just created.