From patchwork Thu Jun 29 00:10:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 13296436 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10B3FEB64DD for ; Thu, 29 Jun 2023 00:10:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232199AbjF2AKe (ORCPT ); Wed, 28 Jun 2023 20:10:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232196AbjF2AKc (ORCPT ); Wed, 28 Jun 2023 20:10:32 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 670E926B6; Wed, 28 Jun 2023 17:10:30 -0700 (PDT) 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-out1.suse.de (Postfix) with ESMTPS id A03122185C; Thu, 29 Jun 2023 00:10:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1687997428; 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; bh=oWyWVgTSEV3MFabbeKzbDXd1Vdi5iQSxxpY/L5jsuOw=; b=s8V4Sn1YTgDq+wvR65+wfyyCHeEq9f5ubYgjQqr3cb1NEuxpXKCCnIl7d0IJEC9oE9dlGS 3uONLBzGHXxtgYtMcMhejeBMyJf0Es6kOEwRbPuIimwBIprVW1rZXD5rLBHusSq58opF+p gPExEqka2TN9dGEKMx2JNZiSCsLnw58= 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 8E5181348C; Thu, 29 Jun 2023 00:10:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 5dYvFvPLnGRTFQAAMHmgww (envelope-from ); Thu, 29 Jun 2023 00:10:27 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org, fstests@vger.kernel.org Cc: Filipe Manana Subject: [PATCH v2] common/btrfs: handle dmdust as mounted device in _btrfs_buffered_read_on_mirror() Date: Thu, 29 Jun 2023 08:10:10 +0800 Message-ID: <20230629001010.36235-1-wqu@suse.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org [BUG] After commit ab41f0bddb73 ("common/btrfs: use _scratch_cycle_mount to ensure all page caches are dropped"), the test case btrfs/143 can fail like below: btrfs/143 6s ... [failed, exit status 1]- output mismatch (see ~/xfstests/results//btrfs/143.out.bad) --- tests/btrfs/143.out 2020-06-10 19:29:03.818519162 +0100 +++ ~/xfstests/results//btrfs/143.out.bad 2023-06-19 17:04:00.575033899 +0100 @@ -1,37 +1,6 @@ QA output created by 143 wrote 131072/131072 bytes XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................ -XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................ -XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................ -XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................ [CAUSE] Test case btrfs/143 uses dm-dust device to emulate read errors, this means we can not use _scratch_cycle_mount to cycle mount $SCRATCH_MNT. As it would go mount $SCRATCH_DEV, not the dm-dust device to $SCRATCH_MNT. This prevents us to trigger read-repair (since no error would be hit) thus fail the test. [FIX] Since we can mount whatever device at $SCRATCH_MNT, we can not use _scratch_cycle_mount in this case. Instead implement a small helper to grab the mounted device and its mount options, and use the same device and mount options to cycle $SCRATCH_MNT mount. This would fix btrfs/143 and hopefully future test cases which use dm devices. Reported-by: Filipe Manana Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: Zorro Lang --- Changelog: v2: - Use findmnt command to grab mount options and source device --- common/btrfs | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/common/btrfs b/common/btrfs index 175b33ae..0fec093d 100644 --- a/common/btrfs +++ b/common/btrfs @@ -601,8 +601,17 @@ _btrfs_buffered_read_on_mirror() # The drop_caches doesn't seem to drop every pages on aarch64 with # 64K page size. # So here as another workaround, cycle mount the SCRATCH_MNT to ensure - # the cache are dropped. - _scratch_cycle_mount + # the cache are dropped, but we can not use _scratch_cycle_mount, as + # we may mount whatever dm device at SCRATCH_MNT. + # So here we grab the mounted block device and its mount options, then + # unmount and re-mount with the same device and options. + local dev=$(findmnt -n -T $SCRATCH_MNT -o SOURCE) + local opts=$(findmnt -n -T $SCRATCH_MNT -o OPTIONS) + if [ -z "$dev" -o -z "$opts" ]; then + _fail "failed to grab mount info of $SCRATCH_MNT" + fi + _scratch_unmount + _mount $dev -o $opts $SCRATCH_MNT while [[ -z $( (( BASHPID % nr_mirrors == mirror )) && exec $XFS_IO_PROG \ -c "pread -b $size $offset $size" $file) ]]; do