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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 84922C388F9 for ; Tue, 3 Nov 2020 13:32:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D37C20786 for ; Tue, 3 Nov 2020 13:32:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="LcNy6ozA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729259AbgKCNcI (ORCPT ); Tue, 3 Nov 2020 08:32:08 -0500 Received: from mx2.suse.de ([195.135.220.15]:44928 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729379AbgKCNcF (ORCPT ); Tue, 3 Nov 2020 08:32:05 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1604410324; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4HW27xl7bSd1rK7DTNw+O3TLbSc5iwCo3WqwAwm6x0w=; b=LcNy6ozAY4/xtC27YhzvMA0DRpjCImHze3rTLqkgjy1NrKiWm9JSfOVaHw6L3PDrpw0jRH ClK80ozY1VSjtlvUiFHlBBs/HAACbZ9EyevOC4nWm47RaK0TlPN1pNHTm7q7Q2BLFHQe+P 3d2gDso1lREoax1lWNZJtLKlyTK8oik= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 51F1FAF95 for ; Tue, 3 Nov 2020 13:32:04 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 17/32] btrfs: extent_io: don't allow tree block to cross page boundary for subpage support Date: Tue, 3 Nov 2020 21:30:53 +0800 Message-Id: <20201103133108.148112-18-wqu@suse.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103133108.148112-1-wqu@suse.com> References: <20201103133108.148112-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org As a preparation for subpage sector size support (allowing filesystem with sector size smaller than page size to be mounted) if the sector size is smaller than page size, we don't allow tree block to be read if it crosses 64K(*) boundary. The 64K is selected because: - We are only going to support 64K page size for subpage for now - 64K is also the max node size btrfs supports This ensures that, tree blocks are always contained in one page for a system with 64K page size, which can greatly simplify the handling. Or we need to do complex multi-page handling for tree blocks. Currently the only way to create such tree blocks crossing 64K boundary is by btrfs-convert, which will get fixed soon and doesn't get wide-spread usage. Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 30768e49cf47..30bbaeaa129a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5261,6 +5261,13 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, btrfs_err(fs_info, "bad tree block start %llu", start); return ERR_PTR(-EINVAL); } + if (btrfs_is_subpage(fs_info) && round_down(start, PAGE_SIZE) != + round_down(start + len - 1, PAGE_SIZE)) { + btrfs_err(fs_info, + "tree block crosses page boundary, start %llu nodesize %lu", + start, len); + return ERR_PTR(-EINVAL); + } eb = find_extent_buffer(fs_info, start); if (eb) -- 2.29.2