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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 F2F2BC76191 for ; Thu, 18 Jul 2019 06:16:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0E5721019 for ; Thu, 18 Jul 2019 06:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727640AbfGRGQi (ORCPT ); Thu, 18 Jul 2019 02:16:38 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:2282 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726376AbfGRGQi (ORCPT ); Thu, 18 Jul 2019 02:16:38 -0400 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id E07F390A37039B666C61; Thu, 18 Jul 2019 14:16:35 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.214) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 18 Jul 2019 14:16:32 +0800 Subject: Re: [f2fs-dev] [PATCH v2] f2fs: fix to read source block before invalidating it To: Jaegeuk Kim CC: , References: <20190718013718.70335-1-jaegeuk@kernel.org> <20190718031214.GA78336@jaegeuk-macbookpro.roam.corp.google.com> <19a25101-da74-de98-6ca4-a9fd9fa09ef2@huawei.com> <20190718040005.GA81995@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: <91dbfa33-cda0-e6e7-d62f-6604939142d4@huawei.com> Date: Thu, 18 Jul 2019 14:16:29 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190718040005.GA81995@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/7/18 12:00, Jaegeuk Kim wrote: > On 07/18, Chao Yu wrote: >> On 2019/7/18 11:12, Jaegeuk Kim wrote: >>> f2fs_allocate_data_block() invalidates old block address and enable new block >>> address. Then, if we try to read old block by f2fs_submit_page_bio(), it will >>> give WARN due to reading invalid blocks. >>> >>> Let's make the order sanely back. >> >> Hmm.. to avoid WARM, we may suffer one more memcpy, I suspect this can reduce >> online resize or foreground gc ioctl performance... > > I worried about performance tho, more concern came to me that there may exist a > chance that other thread can allocate and write something in old block address. Me too, however, previous invalid block address should be reused after a checkpoint, and checkpoint should have invalidated meta cache already, so there shouldn't be any race here. /* * invalidate intermediate page cache borrowed from meta inode * which are used for migration of encrypted inode's blocks. */ if (f2fs_sb_has_encrypt(sbi)) invalidate_mapping_pages(META_MAPPING(sbi), MAIN_BLKADDR(sbi), MAX_BLKADDR(sbi) - 1); Thanks, > >> >> Can we just relief to use DATA_GENERIC_ENHANCE_READ for this case...? > > We need to keep consistency for this api. > > Thanks, > >> >>> >>> Signed-off-by: Jaegeuk Kim >> >> Except performance, I'm okay with this change. >> >> Reviewed-by: Chao Yu >> >> Thanks, >> >>> --- >>> v2: >>> I was fixing the comments. :) >>> >>> fs/f2fs/gc.c | 70 +++++++++++++++++++++++++--------------------------- >>> 1 file changed, 34 insertions(+), 36 deletions(-) >>> >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>> index 6691f526fa40..8974672db78f 100644 >>> --- a/fs/f2fs/gc.c >>> +++ b/fs/f2fs/gc.c >>> @@ -796,6 +796,29 @@ static int move_data_block(struct inode *inode, block_t bidx, >>> if (lfs_mode) >>> down_write(&fio.sbi->io_order_lock); >>> >>> + mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi), >>> + fio.old_blkaddr, false); >>> + if (!mpage) >>> + goto up_out; >>> + >>> + fio.encrypted_page = mpage; >>> + >>> + /* read source block in mpage */ >>> + if (!PageUptodate(mpage)) { >>> + err = f2fs_submit_page_bio(&fio); >>> + if (err) { >>> + f2fs_put_page(mpage, 1); >>> + goto up_out; >>> + } >>> + lock_page(mpage); >>> + if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) || >>> + !PageUptodate(mpage))) { >>> + err = -EIO; >>> + f2fs_put_page(mpage, 1); >>> + goto up_out; >>> + } >>> + } >>> + >>> f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, >>> &sum, CURSEG_COLD_DATA, NULL, false); >>> >>> @@ -803,44 +826,18 @@ static int move_data_block(struct inode *inode, block_t bidx, >>> newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS); >>> if (!fio.encrypted_page) { >>> err = -ENOMEM; >>> - goto recover_block; >>> - } >>> - >>> - mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi), >>> - fio.old_blkaddr, FGP_LOCK, GFP_NOFS); >>> - if (mpage) { >>> - bool updated = false; >>> - >>> - if (PageUptodate(mpage)) { >>> - memcpy(page_address(fio.encrypted_page), >>> - page_address(mpage), PAGE_SIZE); >>> - updated = true; >>> - } >>> f2fs_put_page(mpage, 1); >>> - invalidate_mapping_pages(META_MAPPING(fio.sbi), >>> - fio.old_blkaddr, fio.old_blkaddr); >>> - if (updated) >>> - goto write_page; >>> - } >>> - >>> - err = f2fs_submit_page_bio(&fio); >>> - if (err) >>> - goto put_page_out; >>> - >>> - /* write page */ >>> - lock_page(fio.encrypted_page); >>> - >>> - if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) { >>> - err = -EIO; >>> - goto put_page_out; >>> - } >>> - if (unlikely(!PageUptodate(fio.encrypted_page))) { >>> - err = -EIO; >>> - goto put_page_out; >>> + goto recover_block; >>> } >>> >>> -write_page: >>> + /* write target block */ >>> f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true); >>> + memcpy(page_address(fio.encrypted_page), >>> + page_address(mpage), PAGE_SIZE); >>> + f2fs_put_page(mpage, 1); >>> + invalidate_mapping_pages(META_MAPPING(fio.sbi), >>> + fio.old_blkaddr, fio.old_blkaddr); >>> + >>> set_page_dirty(fio.encrypted_page); >>> if (clear_page_dirty_for_io(fio.encrypted_page)) >>> dec_page_count(fio.sbi, F2FS_DIRTY_META); >>> @@ -871,11 +868,12 @@ static int move_data_block(struct inode *inode, block_t bidx, >>> put_page_out: >>> f2fs_put_page(fio.encrypted_page, 1); >>> recover_block: >>> - if (lfs_mode) >>> - up_write(&fio.sbi->io_order_lock); >>> if (err) >>> f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr, >>> true, true); >>> +up_out: >>> + if (lfs_mode) >>> + up_write(&fio.sbi->io_order_lock); >>> put_out: >>> f2fs_put_dnode(&dn); >>> out: >>> >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > . >