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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 D39FCC43461 for ; Wed, 9 Sep 2020 17:35:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8197206D4 for ; Wed, 9 Sep 2020 17:35:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729911AbgIIRfD (ORCPT ); Wed, 9 Sep 2020 13:35:03 -0400 Received: from mx2.suse.de ([195.135.220.15]:58724 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726415AbgIIRfB (ORCPT ); Wed, 9 Sep 2020 13:35:01 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 795ABB36E; Wed, 9 Sep 2020 17:35:16 +0000 (UTC) Date: Wed, 9 Sep 2020 12:34:57 -0500 From: Goldwyn Rodrigues To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH 14/17] btrfs: make btrfs_readpage_end_io_hook() follow sector size Message-ID: <20200909173457.e4gpsbwkcsxtdo4g@fiona> References: <20200908075230.86856-1-wqu@suse.com> <20200908075230.86856-15-wqu@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200908075230.86856-15-wqu@suse.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 15:52 08/09, Qu Wenruo wrote: > Currently btrfs_readpage_end_io_hook() just pass the whole page to > check_data_csum(), which is fine since we only support sectorsize == > PAGE_SIZE. > > To support subpage RO support, we need to properly honor per-sector > checksum verification, just like what we did in dio read path. > > This patch will do the csum verification in a for loop, starts with > pg_off == start - page_offset(page), with sectorsize increasement for > each loop. > > For sectorsize == PAGE_SIZE case, the pg_off will always be 0, and we > will only finish with just one loop. > > For subpage, we do the proper loop. > > Signed-off-by: Goldwyn Rodrigues > Signed-off-by: Qu Wenruo > --- > fs/btrfs/inode.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 078735aa0f68..8bd14dda2067 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -2851,9 +2851,12 @@ static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, > u64 start, u64 end, int mirror) > { > size_t offset = start - page_offset(page); > + size_t pg_off; > struct inode *inode = page->mapping->host; > struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; > struct btrfs_root *root = BTRFS_I(inode)->root; > + u32 sectorsize = root->fs_info->sectorsize; > + bool found_err = false; > > if (PageChecked(page)) { > ClearPageChecked(page); > @@ -2870,7 +2873,17 @@ static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, > } > > phy_offset >>= inode->i_sb->s_blocksize_bits; > - return check_data_csum(inode, io_bio, phy_offset, page, offset); > + for (pg_off = offset; pg_off < end - page_offset(page); > + pg_off += sectorsize, phy_offset++) { > + int ret; > + > + ret = check_data_csum(inode, io_bio, phy_offset, page, pg_off); > + if (ret < 0) > + found_err = true; > + } > + if (found_err) > + return -EIO; > + return 0; > } We don't need found_err here. Just return ret when you encounter the first error. -- Goldwyn