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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1217BC433EF for ; Mon, 1 Nov 2021 06:28:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D74B961077 for ; Mon, 1 Nov 2021 06:28:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230289AbhKAGbL (ORCPT ); Mon, 1 Nov 2021 02:31:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:51774 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229958AbhKAGbJ (ORCPT ); Mon, 1 Nov 2021 02:31:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7CB9160F45; Mon, 1 Nov 2021 06:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635748116; bh=Q35jh+CN4KR3qBGtwUC476UVincVnoNSqWeaxprxOfI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=R2IlUzHUzSP/BewvftxjuQt8MwiNhPrq/OUyksH0OCvt2gQUexj7tfumXGgRJ5ysH rBdJn/1Gt+FB9eFiy5mUlc4U3OVocTYbGeqknoXVBdq9kMK7EFI5ENtdPrXHVnjMxP w+guFrtqhmIBZsm+TVMetoH6eHpGE9AAOoL0H4t/138d5cH884XqggGw24uc1UbVHW vX5tmklSWetaX6jRIRn8PIbp7NY201+TBIYrqzKmNAke05Xdycho+1M6YHQSHYmeh0 PPz3mFkWFRA9M4JQVyAFYglf/1ro/KbYmJ++ULKiP1gycUDDjCN0M7O3NTvLCOHHiC T0HvGDOfZfXFQ== Message-ID: Date: Mon, 1 Nov 2021 14:28:32 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [PATCH] F2FS: invalidate META_MAPPING before IPU/DIO write Content-Language: en-US To: Hyeong-Jun Kim , Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <20211101054214.24456-1-hj514.kim@samsung.com> From: Chao Yu In-Reply-To: <20211101054214.24456-1-hj514.kim@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/11/1 13:42, Hyeong-Jun Kim wrote: > Encrypted pages during GC are read and cached in META_MAPPING. > However, due to cached pages in META_MAPPING, there is an issue where > newly written pages are lost by IPU or DIO writes. > > Thread A Thread B > - f2fs_gc(): blk 0x10 -> 0x20 (a) > - IPU or DIO write on blk 0x20 (b) > - f2fs_gc(): blk 0x20 -> 0x30 (c) > > (a) page for blk 0x20 is cached in META_MAPPING and page for blk 0x10 > is invalidated from META_MAPPING. > (b) write new data to blk 0x200 using IPU or DIO, but outdated data > still remains in META_MAPPING. > (c) f2fs_gc() try to move blk from 0x20 to 0x30 using cached page in > META_MAPPING. In conclusion, the newly written data in (b) is lost. In c), f2fs_gc() will readahead encrypted block from disk via ra_data_block() anyway, not matter cached encrypted page of meta inode is uptodate or not, so it's safe, right? Am I missing anything? Thanks, > > To address this issue, invalidating pages in META_MAPPING before IPU or > DIO write. > > Signed-off-by: Hyeong-Jun Kim > --- > fs/f2fs/data.c | 2 ++ > fs/f2fs/segment.c | 3 +++ > 2 files changed, 5 insertions(+) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 74e1a350c1d8..9f754aaef558 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1708,6 +1708,8 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, > */ > f2fs_wait_on_block_writeback_range(inode, > map->m_pblk, map->m_len); > + invalidate_mapping_pages(META_MAPPING(sbi), > + map->m_pblk, map->m_pblk); > > if (map->m_multidev_dio) { > block_t blk_addr = map->m_pblk; > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 526423fe84ce..f57c55190f9e 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3652,6 +3652,9 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio) > goto drop_bio; > } > > + invalidate_mapping_pages(META_MAPPING(fio->sbi), > + fio->new_blkaddr, fio->new_blkaddr); > + > stat_inc_inplace_blocks(fio->sbi); > > if (fio->bio && !(SM_I(sbi)->ipu_policy & (1 << F2FS_IPU_NOCACHE))) >