cgroup writeback accounting does not track partition level statistics. Instead, I/O is accounted against the parent device. As a result, the test fails if the scratch device happens to be a device partition. Since parent level stats are potentially polluted by factors external to the test, wrap the scratch device in a loopback device to guarantee the test always runs on a top-level block device. Reported-by: Boyang Xue <bxue@xxxxxxxxxx> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> --- tests/generic/563 | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/tests/generic/563 b/tests/generic/563 index 51deaa2f..9292dece 100755 --- a/tests/generic/563 +++ b/tests/generic/563 @@ -2,7 +2,7 @@ # SPDX-License-Identifier: GPL-2.0 # Copyright (c) 2019 Red Hat, Inc. All Rights Reserved. # -# FS QA Test No. 011 +# FS QA Test No. 563 # # This test verifies that cgroup aware writeback properly accounts I/Os in # various scenarios. We perform reads/writes from different combinations of @@ -26,6 +26,8 @@ _cleanup() echo $$ > $cgdir/cgroup.procs rmdir $cgdir/$seq-cg* > /dev/null 2>&1 + umount $SCRATCH_MNT > /dev/null 2>&1 + _destroy_loop_device $LOOP_DEV > /dev/null 2>&1 } # get standard environment, filters and checks @@ -42,14 +44,12 @@ rm -f $seqres.full _supported_fs generic _require_scratch _require_cgroup2 io +_require_loop # cgroup v2 writeback is only support on block devices so far _require_block_device $SCRATCH_DEV -smajor=$((0x`stat -L -c %t $SCRATCH_DEV`)) -sminor=$((0x`stat -L -c %T $SCRATCH_DEV`)) cgdir=$CGROUP2_PATH - iosize=$((1024 * 1024 * 8)) # Check cgroup read/write charges against expected values. Allow for some @@ -89,12 +89,19 @@ reset() rmdir $cgdir/$seq-cg* > /dev/null 2>&1 $XFS_IO_PROG -fc "pwrite 0 $iosize" $SCRATCH_MNT/file \ >> $seqres.full 2>&1 - _scratch_cycle_mount || _fail "mount failed" + umount $SCRATCH_MNT || _fail "umount failed" + _mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed" stat $SCRATCH_MNT/file > /dev/null } -_scratch_mkfs >> $seqres.full 2>&1 -_scratch_mount +# cgroup I/O accounting doesn't work on partitions. Use a loop device to rule +# that out. +LOOP_DEV=$(_create_loop_device $SCRATCH_DEV) +smajor=$((0x`stat -L -c %t $LOOP_DEV`)) +sminor=$((0x`stat -L -c %T $LOOP_DEV`)) + +_mkfs_dev $LOOP_DEV >> $seqres.full 2>&1 +_mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed" echo "+io" > $cgdir/cgroup.subtree_control || _fail "subtree control" -- 2.26.2
