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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B5FDCC4743C for ; Fri, 4 Jun 2021 23:52:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93A0261402 for ; Fri, 4 Jun 2021 23:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230185AbhFDXxt (ORCPT ); Fri, 4 Jun 2021 19:53:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:58378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229847AbhFDXxs (ORCPT ); Fri, 4 Jun 2021 19:53:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EBD6D610A1; Fri, 4 Jun 2021 23:52:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622850721; bh=qCjXgnCl9FdZQfRULw5SBfr3fWTQZ1wasT9D3vMby5U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oHTJrLgtTvGCAl9x9HsDbdhvPbSjhalRsvKvmZ3WctEqQUcnUMnCQIqtNjpXOYKtE 6rCz8Iu8sKftaF45WN+nYXK5qx5IHpRHcDERMoaH7wu1QQyXF5mF5jqkBY1n3N6rKT djtaLdX0CTmmmDhz2nmGfhsJgXEHvBmdSAYwmnrW7lgxUyHuDgKH8D0dCydf4arevk uBCr8MIqc08u88x+pwq5hLjaLWkOaab6S4qxg1jCfyumgcylE3aoLv2HUHRsS7gPJQ De0onxAl6mBnXXTC6LAJ4pI+smQDaLswydbIW/HNVy+SMMNFrxjb+QT0I/y33R++bo 5xvaFQw8o55GQ== Date: Fri, 4 Jun 2021 16:51:58 -0700 From: Jaegeuk Kim To: Chao Yu Cc: Chao Yu , linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] f2fs: swap: remove dead codes Message-ID: References: <20210526062927.52629-1-yuchao0@huawei.com> <21ec5a95-bdbc-358d-99c7-e75e91228039@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/04, Chao Yu wrote: > 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 Yeah, we need to block the large page support unfortunately. :( > > 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 > > > . > > >