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=-18.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 69B70C07E94 for ; Fri, 4 Jun 2021 11:12:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 538FE6136E for ; Fri, 4 Jun 2021 11:12:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230163AbhFDLOR (ORCPT ); Fri, 4 Jun 2021 07:14:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:53806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230127AbhFDLOP (ORCPT ); Fri, 4 Jun 2021 07:14:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C0130613FF; Fri, 4 Jun 2021 11:12:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622805149; bh=EaamOoaxvp+eQyHQXEhJxeYA2RnZ//SUI/o659y+jJY=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=EWM/2B1XN6YBGSv0Zb0Sc8pn4U8YjYdezg4H7L7uBzpiSzfFE0z22Dkc7AyFPPaUc 2z9ukyY6n1yrPv43KDJNn7uMbtejOTulRr0+EhV8Pprgjrikos6z9/xdUtige+D5Sy Nq2iSa1w0/fjGDTuUOp1NA9UPd+4Oo0b8sZ7iZbJdT4c9vcG9l3ujUFq+S7YfKsnJ7 Sb6cXOYkKdep8n32M2MEvNy5amcjLRX8zT6VSaOWkqvJlRonVqVSd0JYG1Yzo3lqxv rfQvMNAWkk67eTh5RqP6VqQh1AIoRVDuoGCgRY6LAsj1iS+MJaxA49wEZIX3YbF4O+ S4+QYV/TxinbQ== Subject: Re: [PATCH 1/2] f2fs: swap: remove dead codes To: Chao Yu , Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <20210526062927.52629-1-yuchao0@huawei.com> <21ec5a95-bdbc-358d-99c7-e75e91228039@huawei.com> From: Chao Yu Message-ID: Date: Fri, 4 Jun 2021 19:12:27 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <21ec5a95-bdbc-358d-99c7-e75e91228039@huawei.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/5/27 10:12, Chao Yu wrote: > On 2021/5/27 9:40, Jaegeuk Kim wrote: >> On 05/26, Chao Yu wrote: >>> On 2021/5/26 21:30, Jaegeuk Kim wrote: >>>> On 05/26, Chao Yu wrote: >>>>> After commit af4b6b8edf6a ("f2fs: introduce check_swap_activate_fast()"), >>>>> we will never run into original logic of check_swap_activate() before >>>>> f2fs supports non 4k-sized page, so let's delete those dead codes. >>>> >>>> Why not keeping this for large page support in future maybe? >>> >>> Well, if so, at that time, it would be better to refactor >>> check_swap_activate_fast() implementation based on f2fs_map_block() rather >>> than refactoring check_swap_activate() implementation based on low efficient >>> bmap()? >> >> Let's first check whether we support large page. Have you quickly tested it? >> If we support it now and current flow is just inefficient, I'd say keeping but >> refactoring it later. > > Let me check this, but I guess it missed to handle large page in lots of flows, > not sure where we may panic at... :( I've checked f2fs behavior on 64kb page size in arm64 vm, - 'ls -ls' will cause f2fs printing "invalid namelen(0), ino:%u, run fsck to fix." each time. - after touch a file and umount, fsck reports that image is corrupted. F2FS uses PAGE_SIZE and F2FS_BLKSIZE directly in a lot of places, I doubt most of places may not consider large page size condition. So, thoughts? I guess we have to admit we do not support 64KB page right now... :P Thanks, > > Thanks, > >> >>> >>> Thanks, >>> >>>> >>>>> >>>>> Signed-off-by: Chao Yu >>>>> --- >>>>>    fs/f2fs/data.c | 171 +------------------------------------------------ >>>>>    1 file changed, 3 insertions(+), 168 deletions(-) >>>>> >>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c >>>>> index 3058c7e28b11..9c23fde93b76 100644 >>>>> --- a/fs/f2fs/data.c >>>>> +++ b/fs/f2fs/data.c >>>>> @@ -3830,67 +3830,7 @@ int f2fs_migrate_page(struct address_space *mapping, >>>>>    #endif >>>>>    #ifdef CONFIG_SWAP >>>>> -static int f2fs_is_file_aligned(struct inode *inode) >>>>> -{ >>>>> -    struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >>>>> -    block_t main_blkaddr = SM_I(sbi)->main_blkaddr; >>>>> -    block_t cur_lblock; >>>>> -    block_t last_lblock; >>>>> -    block_t pblock; >>>>> -    unsigned long nr_pblocks; >>>>> -    unsigned int blocks_per_sec = BLKS_PER_SEC(sbi); >>>>> -    unsigned int not_aligned = 0; >>>>> -    int ret = 0; >>>>> - >>>>> -    cur_lblock = 0; >>>>> -    last_lblock = bytes_to_blks(inode, i_size_read(inode)); >>>>> - >>>>> -    while (cur_lblock < last_lblock) { >>>>> -        struct f2fs_map_blocks map; >>>>> - >>>>> -        memset(&map, 0, sizeof(map)); >>>>> -        map.m_lblk = cur_lblock; >>>>> -        map.m_len = last_lblock - cur_lblock; >>>>> -        map.m_next_pgofs = NULL; >>>>> -        map.m_next_extent = NULL; >>>>> -        map.m_seg_type = NO_CHECK_TYPE; >>>>> -        map.m_may_create = false; >>>>> - >>>>> -        ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP); >>>>> -        if (ret) >>>>> -            goto out; >>>>> - >>>>> -        /* hole */ >>>>> -        if (!(map.m_flags & F2FS_MAP_FLAGS)) { >>>>> -            f2fs_err(sbi, "Swapfile has holes\n"); >>>>> -            ret = -ENOENT; >>>>> -            goto out; >>>>> -        } >>>>> - >>>>> -        pblock = map.m_pblk; >>>>> -        nr_pblocks = map.m_len; >>>>> - >>>>> -        if ((pblock - main_blkaddr) & (blocks_per_sec - 1) || >>>>> -            nr_pblocks & (blocks_per_sec - 1)) { >>>>> -            if (f2fs_is_pinned_file(inode)) { >>>>> -                f2fs_err(sbi, "Swapfile does not align to section"); >>>>> -                ret = -EINVAL; >>>>> -                goto out; >>>>> -            } >>>>> -            not_aligned++; >>>>> -        } >>>>> - >>>>> -        cur_lblock += nr_pblocks; >>>>> -    } >>>>> -    if (not_aligned) >>>>> -        f2fs_warn(sbi, "Swapfile (%u) is not align to section: \n" >>>>> -            "\t1) creat(), 2) ioctl(F2FS_IOC_SET_PIN_FILE), 3) fallocate()", >>>>> -            not_aligned); >>>>> -out: >>>>> -    return ret; >>>>> -} >>>>> - >>>>> -static int check_swap_activate_fast(struct swap_info_struct *sis, >>>>> +static int check_swap_activate(struct swap_info_struct *sis, >>>>>                    struct file *swap_file, sector_t *span) >>>>>    { >>>>>        struct address_space *mapping = swap_file->f_mapping; >>>>> @@ -3907,6 +3847,8 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, >>>>>        unsigned int not_aligned = 0; >>>>>        int ret = 0; >>>>> +    f2fs_bug_on(sbi, PAGE_SIZE != F2FS_BLKSIZE); >>>>> + >>>>>        /* >>>>>         * Map all the blocks into the extent list.  This code doesn't try >>>>>         * to be very smart. >>>>> @@ -3986,113 +3928,6 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, >>>>>        return ret; >>>>>    } >>>>> -/* Copied from generic_swapfile_activate() to check any holes */ >>>>> -static int check_swap_activate(struct swap_info_struct *sis, >>>>> -                struct file *swap_file, sector_t *span) >>>>> -{ >>>>> -    struct address_space *mapping = swap_file->f_mapping; >>>>> -    struct inode *inode = mapping->host; >>>>> -    struct f2fs_sb_info *sbi = F2FS_I_SB(inode); >>>>> -    unsigned blocks_per_page; >>>>> -    unsigned long page_no; >>>>> -    sector_t probe_block; >>>>> -    sector_t last_block; >>>>> -    sector_t lowest_block = -1; >>>>> -    sector_t highest_block = 0; >>>>> -    int nr_extents = 0; >>>>> -    int ret = 0; >>>>> - >>>>> -    if (PAGE_SIZE == F2FS_BLKSIZE) >>>>> -        return check_swap_activate_fast(sis, swap_file, span); >>>>> - >>>>> -    ret = f2fs_is_file_aligned(inode); >>>>> -    if (ret) >>>>> -        goto out; >>>>> - >>>>> -    blocks_per_page = bytes_to_blks(inode, PAGE_SIZE); >>>>> - >>>>> -    /* >>>>> -     * Map all the blocks into the extent list.  This code doesn't try >>>>> -     * to be very smart. >>>>> -     */ >>>>> -    probe_block = 0; >>>>> -    page_no = 0; >>>>> -    last_block = bytes_to_blks(inode, i_size_read(inode)); >>>>> -    while ((probe_block + blocks_per_page) <= last_block && >>>>> -            page_no < sis->max) { >>>>> -        unsigned block_in_page; >>>>> -        sector_t first_block; >>>>> -        sector_t block = 0; >>>>> - >>>>> -        cond_resched(); >>>>> - >>>>> -        block = probe_block; >>>>> -        ret = bmap(inode, &block); >>>>> -        if (ret) >>>>> -            goto out; >>>>> -        if (!block) >>>>> -            goto bad_bmap; >>>>> -        first_block = block; >>>>> - >>>>> -        /* >>>>> -         * It must be PAGE_SIZE aligned on-disk >>>>> -         */ >>>>> -        if (first_block & (blocks_per_page - 1)) { >>>>> -            probe_block++; >>>>> -            goto reprobe; >>>>> -        } >>>>> - >>>>> -        for (block_in_page = 1; block_in_page < blocks_per_page; >>>>> -                    block_in_page++) { >>>>> - >>>>> -            block = probe_block + block_in_page; >>>>> -            ret = bmap(inode, &block); >>>>> -            if (ret) >>>>> -                goto out; >>>>> -            if (!block) >>>>> -                goto bad_bmap; >>>>> - >>>>> -            if (block != first_block + block_in_page) { >>>>> -                /* Discontiguity */ >>>>> -                probe_block++; >>>>> -                goto reprobe; >>>>> -            } >>>>> -        } >>>>> - >>>>> -        first_block >>= (PAGE_SHIFT - inode->i_blkbits); >>>>> -        if (page_no) {    /* exclude the header page */ >>>>> -            if (first_block < lowest_block) >>>>> -                lowest_block = first_block; >>>>> -            if (first_block > highest_block) >>>>> -                highest_block = first_block; >>>>> -        } >>>>> - >>>>> -        /* >>>>> -         * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks >>>>> -         */ >>>>> -        ret = add_swap_extent(sis, page_no, 1, first_block); >>>>> -        if (ret < 0) >>>>> -            goto out; >>>>> -        nr_extents += ret; >>>>> -        page_no++; >>>>> -        probe_block += blocks_per_page; >>>>> -reprobe: >>>>> -        continue; >>>>> -    } >>>>> -    ret = nr_extents; >>>>> -    *span = 1 + highest_block - lowest_block; >>>>> -    if (page_no == 0) >>>>> -        page_no = 1;    /* force Empty message */ >>>>> -    sis->max = page_no; >>>>> -    sis->pages = page_no - 1; >>>>> -    sis->highest_bit = page_no - 1; >>>>> -out: >>>>> -    return ret; >>>>> -bad_bmap: >>>>> -    f2fs_err(sbi, "Swapfile has holes\n"); >>>>> -    return -EINVAL; >>>>> -} >>>>> - >>>>>    static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file, >>>>>                    sector_t *span) >>>>>    { >>>>> -- >>>>> 2.29.2 >> . >>