* [PATCH v2] generic/563: use a loop device to avoid partition incompatibility
@ 2020-12-14 17:18 Brian Foster
2020-12-15 0:13 ` Zorro Lang
0 siblings, 1 reply; 2+ messages in thread
From: Brian Foster @ 2020-12-14 17:18 UTC (permalink / raw)
To: fstests
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@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
---
v2:
- Use _require_scratch_nocheck() since the scratch device is not used
directly.
v1: https://lore.kernel.org/fstests/20201210161426.1927144-1-bfoster@redhat.com/
tests/generic/563 | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/tests/generic/563 b/tests/generic/563
index 51deaa2f..b113eacf 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
@@ -40,16 +42,14 @@ rm -f $seqres.full
# Modify as appropriate.
_supported_fs generic
-_require_scratch
+_require_scratch_nocheck
_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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] generic/563: use a loop device to avoid partition incompatibility
2020-12-14 17:18 [PATCH v2] generic/563: use a loop device to avoid partition incompatibility Brian Foster
@ 2020-12-15 0:13 ` Zorro Lang
0 siblings, 0 replies; 2+ messages in thread
From: Zorro Lang @ 2020-12-15 0:13 UTC (permalink / raw)
To: Brian Foster; +Cc: fstests
On Mon, Dec 14, 2020 at 12:18:54PM -0500, Brian Foster wrote:
> 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@redhat.com>
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> ---
>
> v2:
> - Use _require_scratch_nocheck() since the scratch device is not used
> directly.
V2 looks good to me, thanks Brian.
Reviewed-by: Zorro Lang <zlang@redhat.com>
> v1: https://lore.kernel.org/fstests/20201210161426.1927144-1-bfoster@redhat.com/
>
> tests/generic/563 | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/tests/generic/563 b/tests/generic/563
> index 51deaa2f..b113eacf 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
> @@ -40,16 +42,14 @@ rm -f $seqres.full
>
> # Modify as appropriate.
> _supported_fs generic
> -_require_scratch
> +_require_scratch_nocheck
> _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
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2020-12-15 0:00 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-14 17:18 [PATCH v2] generic/563: use a loop device to avoid partition incompatibility Brian Foster
2020-12-15 0:13 ` Zorro Lang
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.