From patchwork Thu Apr 16 13:23:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 227929 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 4C01AC2BB85 for ; Thu, 16 Apr 2020 13:29:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2749F217D8 for ; Thu, 16 Apr 2020 13:29:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587043779; bh=0CSh/3iuY/hLOBpsWWHw2RMNg5o9HoNcm5Ux17DNj/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aoMmwJIZ58gymx2PYPDQTOXjVX2vSz0PCGzPYsoXw8fU7BEWMcfKn6kXVmYPfa2KX Jm6vVHJ4JB0e5zHkcprg06lnz0gMC2V21kfUPaoZeZRoscpaHqkxN+7hoQFRNtL23U GZR3uVNbd9kMc4EkBuMBMj+TYY46Q+O6rQrwWr+s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2895403AbgDPN3h (ORCPT ); Thu, 16 Apr 2020 09:29:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:39286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2895195AbgDPN33 (ORCPT ); Thu, 16 Apr 2020 09:29:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 D9DFC208E4; Thu, 16 Apr 2020 13:29:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587043766; bh=0CSh/3iuY/hLOBpsWWHw2RMNg5o9HoNcm5Ux17DNj/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vPNRDfgfjsXaeGzp+lCG+4XQbtI0P94mE56S/J9lX3VpMopO8p4P31IwguDpUTnaQ 6sakn4oPcJkyIDT8GaiSKAXGXb8nzjzpXyHVsTnZlDlFKVeWAbGSTRKzmv/PX+k6SW CZ7hMpkmPZ5LO+ZTwf3s5FAMoPEaz79hO1puuuzg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josef Bacik , Filipe Manana , David Sterba Subject: [PATCH 4.19 092/146] btrfs: fix missing file extent item for hole after ranged fsync Date: Thu, 16 Apr 2020 15:23:53 +0200 Message-Id: <20200416131255.350339700@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131242.353444678@linuxfoundation.org> References: <20200416131242.353444678@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Filipe Manana commit 95418ed1d10774cd9a49af6f39e216c1256f1eeb upstream. When doing a fast fsync for a range that starts at an offset greater than zero, we can end up with a log that when replayed causes the respective inode miss a file extent item representing a hole if we are not using the NO_HOLES feature. This is because for fast fsyncs we don't log any extents that cover a range different from the one requested in the fsync. Example scenario to trigger it: $ mkfs.btrfs -O ^no-holes -f /dev/sdd $ mount /dev/sdd /mnt # Create a file with a single 256K and fsync it to clear to full sync # bit in the inode - we want the msync below to trigger a fast fsync. $ xfs_io -f -c "pwrite -S 0xab 0 256K" -c "fsync" /mnt/foo # Force a transaction commit and wipe out the log tree. $ sync # Dirty 768K of data, increasing the file size to 1Mb, and flush only # the range from 256K to 512K without updating the log tree # (sync_file_range() does not trigger fsync, it only starts writeback # and waits for it to finish). $ xfs_io -c "pwrite -S 0xcd 256K 768K" /mnt/foo $ xfs_io -c "sync_range -abw 256K 256K" /mnt/foo # Now dirty the range from 768K to 1M again and sync that range. $ xfs_io -c "mmap -w 768K 256K" \ -c "mwrite -S 0xef 768K 256K" \ -c "msync -s 768K 256K" \ -c "munmap" \ /mnt/foo # Mount to replay the log. $ mount /dev/sdd /mnt $ umount /mnt $ btrfs check /dev/sdd Opening filesystem to check... Checking filesystem on /dev/sdd UUID: 482fb574-b288-478e-a190-a9c44a78fca6 [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 257 errors 100, file extent discount Found file extent holes: start: 262144, len: 524288 ERROR: errors found in fs roots found 720896 bytes used, error(s) found total csum bytes: 512 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 123514 file data blocks allocated: 589824 referenced 589824 Fix this issue by setting the range to full (0 to LLONG_MAX) when the NO_HOLES feature is not enabled. This results in extra work being done but it gives the guarantee we don't end up with missing holes after replaying the log. CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/file.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2074,6 +2074,16 @@ int btrfs_sync_file(struct file *file, l btrfs_init_log_ctx(&ctx, inode); /* + * Set the range to full if the NO_HOLES feature is not enabled. + * This is to avoid missing file extent items representing holes after + * replaying the log. + */ + if (!btrfs_fs_incompat(fs_info, NO_HOLES)) { + start = 0; + end = LLONG_MAX; + } + + /* * We write the dirty pages in the range and wait until they complete * out of the ->i_mutex. If so, we can flush the dirty pages by * multi-task, and make the performance up. See