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,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 D0286C2BB40 for ; Thu, 10 Dec 2020 06:40:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5D0E23B98 for ; Thu, 10 Dec 2020 06:40:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387517AbgLJGko (ORCPT ); Thu, 10 Dec 2020 01:40:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:44480 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387509AbgLJGkn (ORCPT ); Thu, 10 Dec 2020 01:40:43 -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=1607582365; 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=ZnCrpoA00SFFkg7Z7w3jxgyxla+miDCFxeSFMF/iyK8=; b=VlZNw5izXftxjPpIYM/UkVFp9gQyq794AFy8eJjmIdsLXG9gZsTC8fAbJP3NkHRPoOcFE+ Vxm0LxErgO/2neVXG1N03rSA+1VxJ7JebgRQzZ7dTraYDY5pGj55H/9+QOT/QRQrJl2Z1P bHUVgZRbc3iV1IDjoeDlh9xJ0cZWa8M= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C9398AD2B for ; Thu, 10 Dec 2020 06:39:25 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 08/18] btrfs: extent_io: support subpage for extent buffer page release Date: Thu, 10 Dec 2020 14:38:55 +0800 Message-Id: <20201210063905.75727-9-wqu@suse.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210063905.75727-1-wqu@suse.com> References: <20201210063905.75727-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org In btrfs_release_extent_buffer_pages(), we need to add extra handling for subpage. To do so, introduce a new helper, detach_extent_buffer_page(), to do different handling for regular and subpage cases. For subpage case, the new trick is to clear the range of current extent buffer, and detach page private if and only if we're the last tree block of the page. This part is handled by the subpage helper, btrfs_subpage_clear_and_test_tree_block(). Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 59 +++++++++++++++++++++++++++++++------------- fs/btrfs/subpage.h | 24 ++++++++++++++++++ 2 files changed, 66 insertions(+), 17 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index b99bd0402130..ee81a2a1baa2 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4994,25 +4994,12 @@ int extent_buffer_under_io(const struct extent_buffer *eb) test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); } -/* - * Release all pages attached to the extent buffer. - */ -static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) +static void detach_extent_buffer_page(struct extent_buffer *eb, + struct page *page) { - int i; - int num_pages; - int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); - - BUG_ON(extent_buffer_under_io(eb)); - - num_pages = num_extent_pages(eb); - for (i = 0; i < num_pages; i++) { - struct page *page = eb->pages[i]; + struct btrfs_fs_info *fs_info = eb->fs_info; - if (!page) - continue; - if (mapped) - spin_lock(&page->mapping->private_lock); + if (fs_info->sectorsize == PAGE_SIZE) { /* * We do this since we'll remove the pages after we've * removed the eb from the radix tree, so we could race @@ -5031,6 +5018,44 @@ static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) */ detach_page_private(page); } + return; + } + + /* + * For subpage case, clear the range in tree_block_bitmap, + * and if we're the last one, detach private completely. + */ + if (PagePrivate(page)) { + bool last = false; + + last = btrfs_subpage_clear_and_test_tree_block(fs_info, page, + eb->start, eb->len); + if (last) + btrfs_detach_subpage(fs_info, page); + } +} + +/* + * Release all pages attached to the extent buffer. + */ +static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb) +{ + int i; + int num_pages; + int mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); + + ASSERT(!extent_buffer_under_io(eb)); + + num_pages = num_extent_pages(eb); + for (i = 0; i < num_pages; i++) { + struct page *page = eb->pages[i]; + + if (!page) + continue; + if (mapped) + spin_lock(&page->mapping->private_lock); + + detach_extent_buffer_page(eb, page); if (mapped) spin_unlock(&page->mapping->private_lock); diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index c2ce603e7848..87b4e028ae18 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -72,4 +72,28 @@ static inline void btrfs_subpage_set_tree_block(struct btrfs_fs_info *fs_info, spin_unlock_irqrestore(&subpage->lock, flags); } +/* + * Clear the bits in tree_block_bitmap and return if we're the last bit set + * int tree_block_bitmap. + * + * Return true if we're the last bits in the tree_block_bitmap. + * Return false otherwise. + */ +static inline bool btrfs_subpage_clear_and_test_tree_block( + 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 last = false; + + spin_lock_irqsave(&subpage->lock, flags); + subpage->tree_block_bitmap &= ~tmp; + if (subpage->tree_block_bitmap == 0) + last = true; + spin_unlock_irqrestore(&subpage->lock, flags); + return last; +} + #endif /* BTRFS_SUBPAGE_H */ -- 2.29.2