From patchwork Sat Jan 16 07:15:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 12024645 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,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 CD8ABC433E9 for ; Sat, 16 Jan 2021 07:17:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F02F23AC4 for ; Sat, 16 Jan 2021 07:17:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726722AbhAPHRP (ORCPT ); Sat, 16 Jan 2021 02:17:15 -0500 Received: from mx2.suse.de ([195.135.220.15]:56154 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726653AbhAPHRP (ORCPT ); Sat, 16 Jan 2021 02:17:15 -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=1610781365; h=from:from:reply-to: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=0uWXYvTEdjZsKzp6m1nuGl0nVLq/mq2rMKyNgnW8ysQ=; b=adOSqopPrt8QW7SUYfgu2UMXnyR3NYWS4GmJ+TWwUHelDpgVvnbalCn8GmaVPUsvpg/+1x RsEETtKvft3qO5vUwVB2jc4tXOfwYhC86DwDbZ//YCdZ+kZ2o7G8Z9h4RIIXtIU9tZifPH cNecLEnQcxldcgCv0MlwofoTqR4FuPM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1AB42B7F9 for ; Sat, 16 Jan 2021 07:16:05 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v4 08/18] btrfs: introduce helper for subpage uptodate status Date: Sat, 16 Jan 2021 15:15:23 +0800 Message-Id: <20210116071533.105780-9-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 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This patch introduce the following functions to handle btrfs subpage uptodate status: - btrfs_subpage_set_uptodate() - btrfs_subpage_clear_uptodate() - btrfs_subpage_test_uptodate() Those helpers can only be called when the range is ensured to be inside the page. - btrfs_page_set_uptodate() - btrfs_page_clear_uptodate() - btrfs_page_test_uptodate() Those helpers can handle both regular sector size and subpage without problem. Although caller should still ensure that the range is inside the page. Signed-off-by: Qu Wenruo --- fs/btrfs/subpage.h | 115 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index d8b34879368d..3373ef4ffec1 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -23,6 +23,7 @@ struct btrfs_subpage { /* Common members for both data and metadata pages */ spinlock_t lock; + u16 uptodate_bitmap; union { /* Structures only used by metadata */ bool under_alloc; @@ -78,4 +79,118 @@ static inline void btrfs_page_end_meta_alloc(struct btrfs_fs_info *fs_info, 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); +/* + * Convert the [start, start + len) range into a u16 bitmap + * + * E.g. if start == page_offset() + 16K, len = 16K, we get 0x00f0. + */ +static inline u16 btrfs_subpage_calc_bitmap(struct btrfs_fs_info *fs_info, + struct page *page, u64 start, u32 len) +{ + int bit_start = offset_in_page(start) >> fs_info->sectorsize_bits; + int nbits = len >> fs_info->sectorsize_bits; + + /* Basic checks */ + ASSERT(PagePrivate(page) && page->private); + ASSERT(IS_ALIGNED(start, fs_info->sectorsize) && + IS_ALIGNED(len, fs_info->sectorsize)); + + /* + * The range check only works for mapped page, we can + * still have unampped page like dummy extent buffer pages. + */ + if (page->mapping) + ASSERT(page_offset(page) <= start && + start + len <= page_offset(page) + PAGE_SIZE); + /* + * Here nbits can be 16, thus can go beyond u16 range. Here we make the + * first left shift to be calculated in unsigned long (u32), then + * truncate the result to u16. + */ + return (u16)(((1UL << nbits) - 1) << bit_start); +} + +static inline void btrfs_subpage_set_uptodate(struct btrfs_fs_info *fs_info, + struct page *page, u64 start, u32 len) +{ + struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; + u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len); + unsigned long flags; + + spin_lock_irqsave(&subpage->lock, flags); + subpage->uptodate_bitmap |= tmp; + if (subpage->uptodate_bitmap == U16_MAX) + SetPageUptodate(page); + spin_unlock_irqrestore(&subpage->lock, flags); +} + +static inline void btrfs_subpage_clear_uptodate(struct btrfs_fs_info *fs_info, + struct page *page, u64 start, u32 len) +{ + struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; + u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len); + unsigned long flags; + + spin_lock_irqsave(&subpage->lock, flags); + subpage->uptodate_bitmap &= ~tmp; + ClearPageUptodate(page); + spin_unlock_irqrestore(&subpage->lock, flags); +} + +/* + * Unlike set/clear which is dependent on each page status, for test all bits + * are tested in the same way. + */ +#define DECLARE_BTRFS_SUBPAGE_TEST_OP(name) \ +static inline bool btrfs_subpage_test_##name(struct btrfs_fs_info *fs_info, \ + struct page *page, u64 start, u32 len) \ +{ \ + struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; \ + u16 tmp = btrfs_subpage_calc_bitmap(fs_info, page, start, len); \ + unsigned long flags; \ + bool ret; \ + \ + spin_lock_irqsave(&subpage->lock, flags); \ + ret = ((subpage->name##_bitmap & tmp) == tmp); \ + spin_unlock_irqrestore(&subpage->lock, flags); \ + return ret; \ +} +DECLARE_BTRFS_SUBPAGE_TEST_OP(uptodate); + +/* + * Note that, in selftest, especially extent-io-tests, we can have empty + * fs_info passed in. + * Thankfully in selftest, we only test sectorsize == PAGE_SIZE cases so far, + * thus we can fall back to regular sectorsize branch. + */ +#define DECLARE_BTRFS_PAGE_OPS(name, set_page_func, clear_page_func, \ + test_page_func) \ +static inline void btrfs_page_set_##name(struct btrfs_fs_info *fs_info, \ + struct page *page, u64 start, u32 len) \ +{ \ + if (unlikely(!fs_info) || fs_info->sectorsize == PAGE_SIZE) { \ + set_page_func(page); \ + return; \ + } \ + btrfs_subpage_set_##name(fs_info, page, start, len); \ +} \ +static inline void btrfs_page_clear_##name(struct btrfs_fs_info *fs_info, \ + struct page *page, u64 start, u32 len) \ +{ \ + if (unlikely(!fs_info) || fs_info->sectorsize == PAGE_SIZE) { \ + clear_page_func(page); \ + return; \ + } \ + btrfs_subpage_clear_##name(fs_info, page, start, len); \ +} \ +static inline bool btrfs_page_test_##name(struct btrfs_fs_info *fs_info, \ + struct page *page, u64 start, u32 len) \ +{ \ + if (unlikely(!fs_info) || fs_info->sectorsize == PAGE_SIZE) \ + return test_page_func(page); \ + return btrfs_subpage_test_##name(fs_info, page, start, len); \ +} +DECLARE_BTRFS_PAGE_OPS(uptodate, SetPageUptodate, ClearPageUptodate, + PageUptodate); + #endif /* BTRFS_SUBPAGE_H */