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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07475C433EF for ; Mon, 27 Sep 2021 07:22:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7AE06023D for ; Mon, 27 Sep 2021 07:22:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233299AbhI0HYa (ORCPT ); Mon, 27 Sep 2021 03:24:30 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:56886 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233252AbhI0HYZ (ORCPT ); Mon, 27 Sep 2021 03:24:25 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 77D1720090 for ; Mon, 27 Sep 2021 07:22:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1632727367; 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=1Y1xBM+1fKq1UBRTgrciERuOKE6ZnVr2dGNTsLQ3Btg=; b=iHkHF0kmrilgqPNcjz/93KZ7vvEehl2LZmKdPFaB+xouyJ0x0hLQYPN47+sQhKyqSOeRN2 lo2p6Cp2jvD8wJckjsRWa1tJgM7vq2W+8DsnNU32oIcAI0xzezTi6Wu+ACL/PHRzWSb2F1 0jh/C/cp8y810JtxCL1r8D32DUMefWs= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id D284F13A1E for ; Mon, 27 Sep 2021 07:22:46 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GNErJ0ZxUWEVLAAAMHmgww (envelope-from ) for ; Mon, 27 Sep 2021 07:22:46 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v3 20/26] btrfs: make extent_write_locked_range() to be subpage compatible Date: Mon, 27 Sep 2021 15:22:02 +0800 Message-Id: <20210927072208.21634-21-wqu@suse.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927072208.21634-1-wqu@suse.com> References: <20210927072208.21634-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org There are two sites are not subpage compatible yet for extent_write_locked_range(): - How @nr_pages are calculated For subpage we can have the following range with 64K page size: 0 32K 64K 96K 128K | |////|/////| | In that case, although 96K - 32K == 64K, thus it looks like one page is enough, but the range spans across two pages, not one. Fix it by doing proper round_up() and round_down() to calculate @nr_pages. Also add some extra ASSERT()s to ensure the range passed in is already aligned. - How the page end is calculated Currently we just use cur + PAGE_SIZE - 1 to calculate the page end. Which can't handle above range layout, and will trigger ASSERT() in btrfs_writepage_endio_finish_ordered(), as the range is no longer covered by the page range. Fix it by take page end into consideration. Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 825917f1b623..f05d8896d1ad 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5087,15 +5087,14 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end) struct address_space *mapping = inode->i_mapping; struct page *page; u64 cur = start; - unsigned long nr_pages = (end - start + PAGE_SIZE) >> - PAGE_SHIFT; + unsigned long nr_pages; + const u32 sectorsize = btrfs_sb(inode->i_sb)->sectorsize; struct extent_page_data epd = { .bio_ctrl = { 0 }, .extent_locked = 1, .sync_io = 1, }; struct writeback_control wbc_writepages = { - .nr_to_write = nr_pages * 2, .sync_mode = WB_SYNC_ALL, .range_start = start, .range_end = end + 1, @@ -5104,14 +5103,24 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end) .no_cgroup_owner = 1, }; + ASSERT(IS_ALIGNED(start, sectorsize) && + IS_ALIGNED(end + 1, sectorsize)); + nr_pages = (round_up(end, PAGE_SIZE) - round_down(start, PAGE_SIZE)) >> + PAGE_SHIFT; + wbc_writepages.nr_to_write = nr_pages * 2; + wbc_attach_fdatawrite_inode(&wbc_writepages, inode); while (cur <= end) { + u64 cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, + end); + page = find_get_page(mapping, cur >> PAGE_SHIFT); /* * All pages in the range are locked since * btrfs_run_delalloc_range(), thus there is no way to clear * the page dirty flag. */ + ASSERT(PageLocked(page)); ASSERT(PageDirty(page)); clear_page_dirty_for_io(page); ret = __extent_writepage(page, &wbc_writepages, &epd); @@ -5121,7 +5130,7 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end) first_error = ret; } put_page(page); - cur += PAGE_SIZE; + cur = cur_end + 1; } if (!found_error) -- 2.33.0