From patchwork Tue Sep 8 07:52:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11762761 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 16C40746 for ; Tue, 8 Sep 2020 07:53:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3A1320C09 for ; Tue, 8 Sep 2020 07:53:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729586AbgIHHxC (ORCPT ); Tue, 8 Sep 2020 03:53:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:51070 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729576AbgIHHxB (ORCPT ); Tue, 8 Sep 2020 03:53:01 -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 6183BAE24; Tue, 8 Sep 2020 07:53:01 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: Goldwyn Rodrigues Subject: [PATCH 07/17] btrfs: make csum_tree_block() handle sectorsize smaller than page size Date: Tue, 8 Sep 2020 15:52:20 +0800 Message-Id: <20200908075230.86856-8-wqu@suse.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908075230.86856-1-wqu@suse.com> References: <20200908075230.86856-1-wqu@suse.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org For subpage size support, we only need to handle the first page. To make the code work for both cases, we modify the following behaviors: - num_pages calcuation Instead of "nodesize >> PAGE_SHIFT", we go "DIV_ROUND_UP(nodesize, PAGE_SIZE)", this ensures we get at least one page for subpage size support, while still get the same result for reguar page size. - The length for the first run Instead of PAGE_SIZE - BTRFS_CSUM_SIZE, we go min(PAGE_SIZE, nodesize) - BTRFS_CSUM_SIZE. This allows us to handle both cases well. - The start location of the first run Instead of always use BTRFS_CSUM_SIZE as csum start position, add offset_in_page(eb->start) to get proper offset for both cases. Signed-off-by: Goldwyn Rodrigues Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov --- fs/btrfs/disk-io.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index f6bba7eb1fa1..62dbd9bbd381 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -257,16 +257,16 @@ struct extent_map *btree_get_extent(struct btrfs_inode *inode, static void csum_tree_block(struct extent_buffer *buf, u8 *result) { struct btrfs_fs_info *fs_info = buf->fs_info; - const int num_pages = fs_info->nodesize >> PAGE_SHIFT; + const int num_pages = DIV_ROUND_UP(fs_info->nodesize, PAGE_SIZE); SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); char *kaddr; int i; shash->tfm = fs_info->csum_shash; crypto_shash_init(shash); - kaddr = page_address(buf->pages[0]); + kaddr = page_address(buf->pages[0]) + offset_in_page(buf->start); crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE, - PAGE_SIZE - BTRFS_CSUM_SIZE); + min_t(u32, PAGE_SIZE, fs_info->nodesize) - BTRFS_CSUM_SIZE); for (i = 1; i < num_pages; i++) { kaddr = page_address(buf->pages[i]);