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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 B84AAC433E9 for ; Sat, 16 Jan 2021 07:16:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 883F423AC0 for ; Sat, 16 Jan 2021 07:16:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726640AbhAPHQn (ORCPT ); Sat, 16 Jan 2021 02:16:43 -0500 Received: from mx2.suse.de ([195.135.220.15]:55960 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726545AbhAPHQe (ORCPT ); Sat, 16 Jan 2021 02:16:34 -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=1610781347; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pwqT+kxeNLaN7MWepezkQc+BA1lzrQHStydNIfTLKMU=; b=Amytb6ExS4g7MuhFDQGftu1rsuf2Ps29dX7Nh7kcqjYPBwbDJLNxwnV/LP10msCdLdI8+a ddv4OjeVXM1KCeVB1AwnozwXMYFhMjNYMyzUQU2jP98XhZ5A/RrphuqbrNBl+SPShTEldZ uWjoKeOBj6dB6mZ2jrqAHnABuQjkegI= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A404FB7F4; Sat, 16 Jan 2021 07:15:47 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: Josef Bacik Subject: [PATCH v4 03/18] btrfs: introduce the skeleton of btrfs_subpage structure Date: Sat, 16 Jan 2021 15:15:18 +0800 Message-Id: <20210116071533.105780-4-wqu@suse.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210116071533.105780-1-wqu@suse.com> References: <20210116071533.105780-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org For btrfs subpage support, we need a structure to record extra info for the status of each sectors of a page. This patch will introduce the skeleton structure for future btrfs subpage support. All subpage related code would go to subpage.[ch] to avoid populating the existing code base. Reviewed-by: Josef Bacik Signed-off-by: Qu Wenruo --- fs/btrfs/Makefile | 3 ++- fs/btrfs/subpage.c | 39 +++++++++++++++++++++++++++++++++++++++ fs/btrfs/subpage.h | 31 +++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 1 deletion(-) create mode 100644 fs/btrfs/subpage.c create mode 100644 fs/btrfs/subpage.h diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index 9f1b1a88e317..942562e11456 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -11,7 +11,8 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \ reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \ - block-rsv.o delalloc-space.o block-group.o discard.o reflink.o + block-rsv.o delalloc-space.o block-group.o discard.o reflink.o \ + subpage.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c new file mode 100644 index 000000000000..c6ab32db3995 --- /dev/null +++ b/fs/btrfs/subpage.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "subpage.h" + +int btrfs_attach_subpage(struct btrfs_fs_info *fs_info, struct page *page) +{ + struct btrfs_subpage *subpage; + + /* + * We have cases like a dummy extent buffer page, which is not + * mappped and doesn't need to be locked. + */ + if (page->mapping) + ASSERT(PageLocked(page)); + /* Either not subpage, or the page already has private attached */ + if (fs_info->sectorsize == PAGE_SIZE || PagePrivate(page)) + return 0; + + subpage = kzalloc(sizeof(*subpage), GFP_NOFS); + if (!subpage) + return -ENOMEM; + + spin_lock_init(&subpage->lock); + attach_page_private(page, subpage); + return 0; +} + +void btrfs_detach_subpage(struct btrfs_fs_info *fs_info, struct page *page) +{ + struct btrfs_subpage *subpage; + + /* Either not subpage, or already detached */ + if (fs_info->sectorsize == PAGE_SIZE || !PagePrivate(page)) + return; + + subpage = (struct btrfs_subpage *)detach_page_private(page); + ASSERT(subpage); + kfree(subpage); +} diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h new file mode 100644 index 000000000000..96f3b226913e --- /dev/null +++ b/fs/btrfs/subpage.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_SUBPAGE_H +#define BTRFS_SUBPAGE_H + +#include +#include "ctree.h" + +/* + * Since the maximum page size btrfs is going to support is 64K while the + * minimum sectorsize is 4K, this means a u16 bitmap is enough. + * + * The regular bitmap requires 32 bits as minimal bitmap size, so we can't use + * existing bitmap_* helpers here. + */ +#define BTRFS_SUBPAGE_BITMAP_SIZE 16 + +/* + * Structure to trace status of each sector inside a page. + * + * Will be attached to page::private for both data and metadata inodes. + */ +struct btrfs_subpage { + /* Common members for both data and metadata pages */ + spinlock_t lock; +}; + +int btrfs_attach_subpage(struct btrfs_fs_info *fs_info, struct page *page); +void btrfs_detach_subpage(struct btrfs_fs_info *fs_info, struct page *page); + +#endif /* BTRFS_SUBPAGE_H */ -- 2.30.0