From: Zorro Lang Date: Thu, 12 Jul 2018 05:08:50 +0000 (+0800) Subject: generic: test dm-thin running out of data space vs concurrent discard X-Git-Tag: v2022.05.01~1457 X-Git-Url: http://git.apps.os.sepia.ceph.com/?p=xfstests-dev.git;a=commitdiff_plain;h=2c14233d9175ec6f026af3bbdfd236178490089b generic: test dm-thin running out of data space vs concurrent discard If a user constructs a test that loops repeatedly over below steps on dm-thin, block allocation can fail due to discards not having completed yet (Fixed by a685557 dm thin: handle running out of data space vs concurrent discard): 1) fill thin device via filesystem file 2) remove file 3) fstrim And this maybe cause a deadlock (fast device likes ramdisk can help a lot) when racing a fstrim with a filesystem (XFS) shutdown. (Fixed by 8c81dd46ef3c Force log to disk before reading the AGF during a fstrim) This case can reproduce both two bugs if they're not fixed. If only the dm-thin bug is fixed, then the test will pass. If only the fs bug is fixed, then the test will fail. If both of bugs aren't fixed, the test will hang. Signed-off-by: Zorro Lang Reviewed-by: Eryu Guan Signed-off-by: Eryu Guan --- diff --git a/tests/generic/500 b/tests/generic/500 new file mode 100755 index 00000000..201d8b9f --- /dev/null +++ b/tests/generic/500 @@ -0,0 +1,92 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2018 Red Hat Inc. All Rights Reserved. +# +# FS QA Test No. 500 +# +# Race test running out of data space with concurrent discard operation on +# dm-thin. +# +# If a user constructs a test that loops repeatedly over below steps on +# dm-thin, block allocation can fail due to discards not having completed +# yet (Fixed by a685557 dm thin: handle running out of data space vs +# concurrent discard): +# 1) fill thin device via filesystem file +# 2) remove file +# 3) fstrim +# +# And this maybe cause a deadlock when racing a fstrim with a filesystem +# (XFS) shutdown. (Fixed by 8c81dd46ef3c Force log to disk before reading +# the AGF during a fstrim) +# +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +here=`pwd` +tmp=/tmp/$$ +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + +_cleanup() +{ + cd / + rm -f $tmp.* + _dmthin_cleanup +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter +. ./common/dmthin + +# remove previous $seqres.full before test +rm -f $seqres.full + +# real QA test starts here +_supported_fs generic +_supported_os Linux +_require_scratch_nocheck +_require_dm_target thin-pool + +# Require underlying device support discard +_scratch_mkfs >>$seqres.full 2>&1 +_scratch_mount +_require_batched_discard $SCRATCH_MNT +_scratch_unmount + +# Create a thin pool and a *slightly smaller* thin volume, it's helpful +# to reproduce the bug +BACKING_SIZE=$((128 * 1024 * 1024 / 512)) # 128M +VIRTUAL_SIZE=$((BACKING_SIZE + 1024)) # 128M + 1k +CLUSTER_SIZE=$((64 * 1024 / 512)) # 64K + +_dmthin_init $BACKING_SIZE $VIRTUAL_SIZE $CLUSTER_SIZE 0 +_dmthin_set_fail +_mkfs_dev $DMTHIN_VOL_DEV +_dmthin_mount + +# There're two bugs at here, one is dm-thin bug, the other is filesystem +# (XFS especially) bug. The dm-thin bug can't handle running out of data +# space with concurrent discard well. Then the dm-thin bug cause fs unmount +# hang when racing a fstrim with a filesystem shutdown. +# +# If both of two bugs haven't been fixed, below test maybe cause deadlock. +# Else if the fs bug has been fixed, but the dm-thin bug hasn't. below test +# will cause the test fail (no deadlock). +# Else the test will pass. +for ((i=0; i<20; i++)); do + $XFS_IO_PROG -f -c "pwrite -b 64k 0 256M" \ + $SCRATCH_MNT/testfile &>/dev/null + rm -f $SCRATCH_MNT/testfile + $FSTRIM_PROG $SCRATCH_MNT +done + +_dmthin_check_fs +_dmthin_cleanup + +echo "Silence is golden" + +# success, all done +status=0 +exit diff --git a/tests/generic/500.out b/tests/generic/500.out new file mode 100644 index 00000000..883b2caf --- /dev/null +++ b/tests/generic/500.out @@ -0,0 +1,2 @@ +QA output created by 500 +Silence is golden diff --git a/tests/generic/group b/tests/generic/group index b2a093f4..e130cba4 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -502,3 +502,4 @@ 497 auto quick swap collapse 498 auto quick log 499 auto quick rw collapse zero +500 auto thin trim