From patchwork Sat Mar 18 01:24:48 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Calvin Owens X-Patchwork-Id: 9631993 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 1134B60245 for ; Sat, 18 Mar 2017 03:05:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CD957284C2 for ; Sat, 18 Mar 2017 03:05:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AF71D284FA; Sat, 18 Mar 2017 03:05:34 +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 27CB2284C2 for ; Sat, 18 Mar 2017 03:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751101AbdCRDFb (ORCPT ); Fri, 17 Mar 2017 23:05:31 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:57665 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751185AbdCRDFa (ORCPT ); Fri, 17 Mar 2017 23:05:30 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2I1NePq002889 for ; Fri, 17 Mar 2017 18:24:50 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=facebook; bh=cmfplVw3dsTyW5m+Wd7lwh2uV9iM6S8wj9gSqP6uA58=; b=rcX9c7d3ggzk2QY9udUU6JDJnl6rAemiJvAgPjLdJm/AZIPd8nLSLnY7HjotDAnX5S/T +IkEee/LOYCJq6lyBmmKGS0rw1cIsyq1Kj1QynpVTroMNIDz8hqSm4TtW0H6Pv6nFpJ+ Z5yLN1qOHcNHHJpmK2PM2sHWtZLGGCctEw4= Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 298seyr8j3-2 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Fri, 17 Mar 2017 18:24:50 -0700 Received: from mx-out.facebook.com (192.168.52.123) by PRN-CHUB06.TheFacebook.com (192.168.16.16) with Microsoft SMTP Server (TLS) id 14.3.319.2; Fri, 17 Mar 2017 18:24:49 -0700 Received: from facebook.com (2401:db00:11:d0be:face:0:1b:0) by mx-out.facebook.com (10.103.99.97) with ESMTP id ad750c5e0b7911e7b58b0002c9931860-df9f89a0 for ; Fri, 17 Mar 2017 18:24:48 -0700 Received: by devbig337.prn1.facebook.com (Postfix, from userid 10532) id 9D74365C0D53; Fri, 17 Mar 2017 18:24:48 -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] xfs: Honor FALLOC_FL_KEEP_SIZE when punching ends of files Date: Fri, 17 Mar 2017 18:24:48 -0700 Message-ID: <22a11e65fd5037498a78de61f3ed4dae466ad854.1489791330.git.calvinowens@fb.com> X-Mailer: git-send-email 2.9.3 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=2017-03-17_21:, , 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 Commit 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes") replaced xfs_zero_remaining_bytes() with calls to iomap helpers. Unfortunately the new iomap helpers don't enforce that [pos,count) lies strictly on [0,i_size). This causes fallocate(mode=PUNCH_HOLE|KEEP_SIZE) calls touching [i_size & ~PAGE_MASK, OFF_T_MAX] to round i_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 Fix this by reintroducing the checks xfs_zero_remaining_bytes() did against i_size into xfs_zero_range(). 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_file.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 35703a8..da7cd27 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -58,6 +58,17 @@ xfs_zero_range( xfs_off_t count, bool *did_zero) { + /* + * 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 (pos >= XFS_ISIZE(ip)) + return 0; + + if ((pos + count) >= XFS_ISIZE(ip)) + count = XFS_ISIZE(ip) - pos - 1; + return iomap_zero_range(VFS_I(ip), pos, count, NULL, &xfs_iomap_ops); }