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 865C3C433EF for ; Tue, 2 Nov 2021 06:47:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57D4260F58 for ; Tue, 2 Nov 2021 06:47:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229933AbhKBGuK (ORCPT ); Tue, 2 Nov 2021 02:50:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:46954 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbhKBGuI (ORCPT ); Tue, 2 Nov 2021 02:50:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C889260E8C; Tue, 2 Nov 2021 06:47:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635835653; bh=ZcWf/uumK2zsWoVDh/CeelKvA1JNtdQOPNoEoVKMohs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SeuXyTWP+sAPtAvLUB0OtEvFqEQl3MwnFCmVUXzeMp9XKll9RI43mYm/eFIux78Ef tQ6UY7F5kAfsCAwuEcVZZxvwrxFnYYg7DDldWgYdA7LITyXM3vP34X8yoz/P4VZG2V sc/RzI1vKiT1Gq+UcA1Eu37ct2RYv0MU5KuPbonokzxWZWKWDT0MtGfJ8up7cYPRZJ QiIoXGFPc0oPoq5yW7p8+p9V329FJR9rAmCZQVxUnREinQEnc2wgbzgXOikdX/zCHy OYNGFTfXOldkDxlaDIFjF1fpaGv99wFcIOWnaKuUNYAIzB0IZLBmt1xZXTuEFHjhXR AsA9x5iEqAOOA== Message-ID: <9ee5741f-35f8-c0b9-f045-fb70aa49f6de@kernel.org> Date: Tue, 2 Nov 2021 14:47:30 +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 v3] F2FS: invalidate META_MAPPING before IPU/DIO write Content-Language: en-US To: Hyeong-Jun Kim , Jaegeuk Kim Cc: sj1557.seo@samsung.com, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <20211102045949.63530-1-hj514.kim@samsung.com> From: Chao Yu In-Reply-To: <20211102045949.63530-1-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 2021/11/2 12:59, 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 - f2fs_gc() Thread B > /* phase 3 */ > down_write(i_gc_rwsem) > ra_data_block() ---- (a) > up_write(i_gc_rwsem) > f2fs_direct_IO() : > - down_read(i_gc_rwsem) > - __blockdev_direct_io() > - get_data_block_dio_write() > - f2fs_dio_submit_bio() ---- (b) > - up_read(i_gc_rwsem) > /* phase 4 */ > down_write(i_gc_rwsem) > move_data_block() ---- (c) > up_write(i_gc_rwsem) > > (a) In phase 3 of f2fs_gc(), up-to-date page is read from storage and > cached in META_MAPPING. > (b) In thread B, writing new data by IPU or DIO write on same blkaddr as > read in (a). cached page in META_MAPPING become out-dated. > (c) In phase 4 of f2fs_gc(), out-dated page in META_MAPPING is copied to > new blkaddr. In conclusion, the newly written data in (b) is lost. > > To address this issue, invalidating pages in META_MAPPING before IPU or > DIO write. > > --- > v3: > - Use sbi instead of fio->sbi in f2fs_inplace_write_data() > v2: > - Update patch description with race condition > > Fixes: 6aa58d8ad20a ("f2fs: readahead encrypted block during GC") > Signed-off-by: Hyeong-Jun Kim > --- Change log should be attached here, otherwise Fixes & Signed-off-by tag will be lost after applying this patch. Thanks, > 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..df9ed75f0b7a 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(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))) >