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=-18.7 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 68A77C432BE for ; Mon, 2 Aug 2021 06:54:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48892610A0 for ; Mon, 2 Aug 2021 06:54:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232384AbhHBGzC (ORCPT ); Mon, 2 Aug 2021 02:55:02 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:50012 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231410AbhHBGzB (ORCPT ); Mon, 2 Aug 2021 02:55:01 -0400 Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (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-out1.suse.de (Postfix) with ESMTPS id 1340C21FC1 for ; Mon, 2 Aug 2021 06:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627887292; 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=rdVCkzE0+C+RsCL1j955ktF9woLX4lv0dnOdt5/8VEw=; b=f70F68iwc9nfN0QSZ7rKqeAzPNL1aqkoeafcyHepVfV5Y7LGlwanTpdvUAIvTJ6do+PBwr +ATNbUZKnK7nR0bj2KxgjSegZ2s8ULHuT7dmZakLN4QQ721lS6N6rqA0rcq61cJrplcnMa dluFoTWCv1yFglhtn5UGwXqY6I6h+Ss= Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (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 imap1.suse-dmz.suse.de (Postfix) with ESMTPS id 4B1471371C for ; Mon, 2 Aug 2021 06:54:51 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap1.suse-dmz.suse.de with ESMTPSA id uNVzA7uWB2FtawAAGKfGzw (envelope-from ) for ; Mon, 02 Aug 2021 06:54:51 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 1/2] btrfs: don't try to flush data write bio if we hit error preparing it Date: Mon, 2 Aug 2021 14:54:46 +0800 Message-Id: <20210802065447.178726-2-wqu@suse.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210802065447.178726-1-wqu@suse.com> References: <20210802065447.178726-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org [BUG] When running with 64K page size and 4K sectorsize (aka, subpage), there is a chance that generic/475 would crash with the following BUG_ON() in btrfs_csum_one_bio() triggered: if (!ordered) { ordered = btrfs_lookup_ordered_extent(inode, offset); BUG_ON(!ordered); /* Logic error */ } [CAUSE] Test case generic/475 is doing dm-error testing, while for subpage case we could hit error caused by dm-errors. In that case, we will proper call end_extent_writepage() with @err = 1 to do the cleanup, including finishing the ordered extent. In that case, the assembled bio still needs to be finished, by end_write_bio() function. But there are call sites that doesn't properly call end_write_bio(), but go flush_write_bio() to submit the assembled bio. In that case, we will call btrfs_csum_one_bio() even the ordered extent is already cleaned up, and trigger the BUG_ON(). [FIX] There are two call sites where we still try to call flush_write_bio() even if we hit error: - extent_write_cache_pages() - extent_write_locked_range() Fix both of them by calling end_write_bio() if we hit error. Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index e82328bcb281..49f7dbbb2d73 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5035,9 +5035,13 @@ static int extent_write_cache_pages(struct address_space *mapping, * page in our current bio, and thus deadlock, so flush the * write bio here. */ - ret = flush_write_bio(epd); - if (!ret) - goto retry; + if (ret < 0) { + end_write_bio(epd, ret); + } else { + ret = flush_write_bio(epd); + if (!ret) + goto retry; + } } if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole)) @@ -5095,9 +5099,11 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end, wbc_attach_fdatawrite_inode(&wbc_writepages, inode); while (start <= end) { page = find_get_page(mapping, start >> PAGE_SHIFT); - if (clear_page_dirty_for_io(page)) + if (clear_page_dirty_for_io(page)) { ret = __extent_writepage(page, &wbc_writepages, &epd); - else { + if (ret < 0) + goto out; + } else { btrfs_writepage_endio_finish_ordered(BTRFS_I(inode), page, start, start + PAGE_SIZE - 1, true); unlock_page(page); @@ -5106,6 +5112,7 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end, start += PAGE_SIZE; } +out: ASSERT(ret <= 0); if (ret == 0) ret = flush_write_bio(&epd); -- 2.32.0