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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT 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 9E254C10F03 for ; Tue, 23 Apr 2019 20:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CFE9218C3 for ; Tue, 23 Apr 2019 20:43:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556052237; bh=iZcjfKLoyfuYnmOUWC4K0MAFDsL7Zw7tp4jJqBMS+e8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=yo2wp99vfDZrq5KTQBWA2vhtIgFw9BAfNpqrl97UGLofKpc7y+SqDqMNyWxiuZOO1 HiHwPxqNxNMeexEspvZWxwjJuzOnYZLcf8Mr1AZqj3YFKNpEVHf4NQswp90Ni1tPzm 2/qdRbEs8zu3Ahs2UT0Z6B9Ek6FyZ555hWiQ7BK4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727187AbfDWUn4 (ORCPT ); Tue, 23 Apr 2019 16:43:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:48716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726075AbfDWUn4 (ORCPT ); Tue, 23 Apr 2019 16:43:56 -0400 Received: from localhost (unknown [92.54.175.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A5C5E217D9; Tue, 23 Apr 2019 20:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556052235; bh=iZcjfKLoyfuYnmOUWC4K0MAFDsL7Zw7tp4jJqBMS+e8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WTUg3V9wEcvbaRKi+qIskCk7Bmerv6E3JfIL2RPMgxsq/XP1rfiQmDLVfFt7pdfmW FSl8DGcClxygS87yEx0PTfCwV5smLeNYFxx5npdunXMbwADMQYGXgpdBOFNJ3qdZB5 K4ELVmdAn3EO5Q9Hf+Wkdym5QO5EbChHLoXIDqyY= Date: Tue, 23 Apr 2019 21:43:51 +0100 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org Subject: Re: [PATCH 1/2] f2fs: allow unfixed f2fs_checkpoint.checksum_offset Message-ID: <20190423204351.GA87257@jaegeuk-macbookpro.roam.corp.google.com> References: <20190422093353.61014-1-yuchao0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190422093353.61014-1-yuchao0@huawei.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/22, Chao Yu wrote: > Previously, f2fs_checkpoint.checksum_offset points fixed position of > f2fs_checkpoint structure: > > "#define CP_CHKSUM_OFFSET 4092" > > It is unnecessary, and it breaks the consecutiveness of nat and sit > bitmap stored across checkpoint park block and payload blocks. > > This patch allows f2fs to handle unfixed .checksum_offset. > > In addition, for the case checksum value is stored in the middle of > checkpoint park, calculating checksum value with superposition method > like we did for inode_checksum. > > Signed-off-by: Chao Yu > --- > fs/f2fs/checkpoint.c | 27 +++++++++++++++++++++------ > include/linux/f2fs_fs.h | 4 ++++ > 2 files changed, 25 insertions(+), 6 deletions(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index 441814607b13..a25556aef8cc 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -794,13 +794,27 @@ static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk) > } > } > > +static __u32 f2fs_checkpoint_chksum(struct f2fs_sb_info *sbi, > + struct f2fs_checkpoint *ckpt) > +{ > + unsigned int chksum_ofs = le32_to_cpu(ckpt->checksum_offset); > + __u32 chksum; > + > + chksum = f2fs_crc32(sbi, ckpt, chksum_ofs); > + if (chksum_ofs < CP_CHKSUM_OFFSET) { > + chksum_ofs += sizeof(chksum); > + chksum = f2fs_chksum(sbi, chksum, (__u8 *)ckpt + chksum_ofs, > + F2FS_BLKSIZE - chksum_ofs); Do we need to cover __cp_payload(sbi) * blksize - chksum_ofs? > + } > + return chksum; > +} > + > static int get_checkpoint_version(struct f2fs_sb_info *sbi, block_t cp_addr, > struct f2fs_checkpoint **cp_block, struct page **cp_page, > unsigned long long *version) > { > - unsigned long blk_size = sbi->blocksize; > size_t crc_offset = 0; > - __u32 crc = 0; > + __u32 crc; > > *cp_page = f2fs_get_meta_page(sbi, cp_addr); > if (IS_ERR(*cp_page)) > @@ -809,15 +823,16 @@ static int get_checkpoint_version(struct f2fs_sb_info *sbi, block_t cp_addr, > *cp_block = (struct f2fs_checkpoint *)page_address(*cp_page); > > crc_offset = le32_to_cpu((*cp_block)->checksum_offset); > - if (crc_offset > (blk_size - sizeof(__le32))) { > + if (crc_offset < CP_MIN_CHKSUM_OFFSET || > + crc_offset > CP_CHKSUM_OFFSET) { > f2fs_put_page(*cp_page, 1); > f2fs_msg(sbi->sb, KERN_WARNING, > "invalid crc_offset: %zu", crc_offset); > return -EINVAL; > } > > - crc = cur_cp_crc(*cp_block); > - if (!f2fs_crc_valid(sbi, crc, *cp_block, crc_offset)) { > + crc = f2fs_checkpoint_chksum(sbi, *cp_block); > + if (crc != cur_cp_crc(*cp_block)) { > f2fs_put_page(*cp_page, 1); > f2fs_msg(sbi->sb, KERN_WARNING, "invalid crc value"); > return -EINVAL; > @@ -1425,7 +1440,7 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP)); > get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP)); > > - crc32 = f2fs_crc32(sbi, ckpt, le32_to_cpu(ckpt->checksum_offset)); > + crc32 = f2fs_checkpoint_chksum(sbi, ckpt); > *((__le32 *)((unsigned char *)ckpt + > le32_to_cpu(ckpt->checksum_offset))) > = cpu_to_le32(crc32); > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h > index 55da9abed023..65559900d4d7 100644 > --- a/include/linux/f2fs_fs.h > +++ b/include/linux/f2fs_fs.h > @@ -164,6 +164,10 @@ struct f2fs_checkpoint { > unsigned char sit_nat_version_bitmap[1]; > } __packed; > > +#define CP_CHKSUM_OFFSET 4092 /* default chksum offset in checkpoint */ > +#define CP_MIN_CHKSUM_OFFSET \ > + (offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap)) > + > /* > * For orphan inode management > */ > -- > 2.18.0.rc1