| Message ID | 20181212230959.69975-3-dennis@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add scsi-stress-remove to blktests | expand |
On Wed, Dec 12, 2018 at 06:09:59PM -0500, Dennis Zhou wrote: > This test exposed a race condition with shutting down a request_queue > and the new blkg association. The issue ended up being that while the > request_queue will just start failing requests, blkg destruction sets > the q->root_blkg to %NULL. This caused a NPE when trying to reference > it. So to help prevent this from happening again, integrate Ming's test > into blktests so that it can more easily be ran. > > Signed-off-by: Dennis Zhou <dennis@kernel.org> > Cc: Ming Lei <ming.lei@redhat.com> > --- > tests/block/022 | 96 +++++++++++++++++++++++++++++++++++++++++++++ > tests/block/022.out | 2 + > 2 files changed, 98 insertions(+) > create mode 100755 tests/block/022 > create mode 100644 tests/block/022.out > > diff --git a/tests/block/022 b/tests/block/022 > new file mode 100755 > index 0000000..45bfff7 > --- /dev/null > +++ b/tests/block/022 > @@ -0,0 +1,96 @@ > +#!/bin/bash > +# SPDX-License-Identifier: GPL-3.0+ > +# Copyright (C) 2018 Ming Lei > +# > +# Regression test for patch "blkcg: handle dying request_queue when associating > +# a blkg" > +# > +# This tries to expose the race condition between blkg association and > +# request_queue shutdown. When a request_queue is shutdown, the corresponding > +# blkgs are destroyed. Any further associations should fail gracefully and not > +# cause a kernel panic. > + > +. tests/block/rc > +. common/scsi_debug > +. common/cgroup > + > +DESCRIPTION="test graceful shutdown of scsi_debug devices with running fio jobs" > +QUICK=1 > + > +requires() { > + _have_cgroup2_controller io && _have_scsi_debug && _have_fio > +} > + > +scsi_debug_stress_remove() { > + scsi_debug_path="/sys/bus/pseudo/drivers/scsi_debug" > + count=21 > + > + runtime=12 > + nr_fio_jobs=8 > + scsi_dbg_ndelay=10000 > + > + # set higher aio limit > + echo 524288 > /proc/sys/fs/aio-max-nr > + > + #figure out the CAN_QUEUE > + can_queue=$(((count + 1) * (count / 2) / 2)) > + > + rmmod scsi_debug > /dev/null 2>&1 > + modprobe scsi_debug virtual_gb=128 max_luns=$count \ > + ndelay=$scsi_dbg_ndelay max_queue=$can_queue > + > + # figure out scsi_debug disks > + hosts=$(ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter0/host*) > + hostname=$(basename "$hosts") > + host=$(echo "$hostname" | grep -o -E '[0-9]+') > + > + sdisks=$(ls -d $scsi_debug_path/adapter*/"$hostname"/target*/*/block/*) > + disks="" > + for sd in $sdisks; do > + disks+="/dev/"$(basename "$sd") > + disks+=" " > + done > + > + use_mq=$(cat /sys/module/scsi_mod/parameters/use_blk_mq) > + if [[ $use_mq = "Y" ]]; then > + scheds=("none" "mq-deadline" "kyber") > + else > + scheds=("noop" "deadline" "cfq") > + fi You may use the following to figure out all supported io schedulers, especially we have removed all legacy io schedulers. IOSCHEDS=`sed 's/[][]//g' $Q_PATH/scheduler` Thanks, Ming
On Thu, Dec 13, 2018 at 09:24:09AM +0800, Ming Lei wrote: > On Wed, Dec 12, 2018 at 06:09:59PM -0500, Dennis Zhou wrote: > > This test exposed a race condition with shutting down a request_queue > > and the new blkg association. The issue ended up being that while the > > request_queue will just start failing requests, blkg destruction sets > > the q->root_blkg to %NULL. This caused a NPE when trying to reference > > it. So to help prevent this from happening again, integrate Ming's test > > into blktests so that it can more easily be ran. > > > > Signed-off-by: Dennis Zhou <dennis@kernel.org> > > Cc: Ming Lei <ming.lei@redhat.com> > > --- > > tests/block/022 | 96 +++++++++++++++++++++++++++++++++++++++++++++ > > tests/block/022.out | 2 + > > 2 files changed, 98 insertions(+) > > create mode 100755 tests/block/022 > > create mode 100644 tests/block/022.out > > > > diff --git a/tests/block/022 b/tests/block/022 > > new file mode 100755 > > index 0000000..45bfff7 > > --- /dev/null > > +++ b/tests/block/022 > > @@ -0,0 +1,96 @@ > > +#!/bin/bash > > +# SPDX-License-Identifier: GPL-3.0+ > > +# Copyright (C) 2018 Ming Lei > > +# > > +# Regression test for patch "blkcg: handle dying request_queue when associating > > +# a blkg" > > +# > > +# This tries to expose the race condition between blkg association and > > +# request_queue shutdown. When a request_queue is shutdown, the corresponding > > +# blkgs are destroyed. Any further associations should fail gracefully and not > > +# cause a kernel panic. > > + > > +. tests/block/rc > > +. common/scsi_debug > > +. common/cgroup > > + > > +DESCRIPTION="test graceful shutdown of scsi_debug devices with running fio jobs" > > +QUICK=1 > > + > > +requires() { > > + _have_cgroup2_controller io && _have_scsi_debug && _have_fio > > +} > > + > > +scsi_debug_stress_remove() { > > + scsi_debug_path="/sys/bus/pseudo/drivers/scsi_debug" > > + count=21 > > + > > + runtime=12 > > + nr_fio_jobs=8 > > + scsi_dbg_ndelay=10000 > > + > > + # set higher aio limit > > + echo 524288 > /proc/sys/fs/aio-max-nr > > + > > + #figure out the CAN_QUEUE > > + can_queue=$(((count + 1) * (count / 2) / 2)) > > + > > + rmmod scsi_debug > /dev/null 2>&1 > > + modprobe scsi_debug virtual_gb=128 max_luns=$count \ > > + ndelay=$scsi_dbg_ndelay max_queue=$can_queue > > + > > + # figure out scsi_debug disks > > + hosts=$(ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter0/host*) > > + hostname=$(basename "$hosts") > > + host=$(echo "$hostname" | grep -o -E '[0-9]+') > > + > > + sdisks=$(ls -d $scsi_debug_path/adapter*/"$hostname"/target*/*/block/*) > > + disks="" > > + for sd in $sdisks; do > > + disks+="/dev/"$(basename "$sd") > > + disks+=" " > > + done > > + > > + use_mq=$(cat /sys/module/scsi_mod/parameters/use_blk_mq) > > + if [[ $use_mq = "Y" ]]; then > > + scheds=("none" "mq-deadline" "kyber") > > + else > > + scheds=("noop" "deadline" "cfq") > > + fi > > You may use the following to figure out all supported io schedulers, > especially we have removed all legacy io schedulers. > > IOSCHEDS=`sed 's/[][]//g' $Q_PATH/scheduler` > > > Thanks, > Ming Thanks Ming! I'll post a v2 update for this patch. Thanks, Dennis
diff --git a/tests/block/022 b/tests/block/022 new file mode 100755 index 0000000..45bfff7 --- /dev/null +++ b/tests/block/022 @@ -0,0 +1,96 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-3.0+ +# Copyright (C) 2018 Ming Lei +# +# Regression test for patch "blkcg: handle dying request_queue when associating +# a blkg" +# +# This tries to expose the race condition between blkg association and +# request_queue shutdown. When a request_queue is shutdown, the corresponding +# blkgs are destroyed. Any further associations should fail gracefully and not +# cause a kernel panic. + +. tests/block/rc +. common/scsi_debug +. common/cgroup + +DESCRIPTION="test graceful shutdown of scsi_debug devices with running fio jobs" +QUICK=1 + +requires() { + _have_cgroup2_controller io && _have_scsi_debug && _have_fio +} + +scsi_debug_stress_remove() { + scsi_debug_path="/sys/bus/pseudo/drivers/scsi_debug" + count=21 + + runtime=12 + nr_fio_jobs=8 + scsi_dbg_ndelay=10000 + + # set higher aio limit + echo 524288 > /proc/sys/fs/aio-max-nr + + #figure out the CAN_QUEUE + can_queue=$(((count + 1) * (count / 2) / 2)) + + rmmod scsi_debug > /dev/null 2>&1 + modprobe scsi_debug virtual_gb=128 max_luns=$count \ + ndelay=$scsi_dbg_ndelay max_queue=$can_queue + + # figure out scsi_debug disks + hosts=$(ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter0/host*) + hostname=$(basename "$hosts") + host=$(echo "$hostname" | grep -o -E '[0-9]+') + + sdisks=$(ls -d $scsi_debug_path/adapter*/"$hostname"/target*/*/block/*) + disks="" + for sd in $sdisks; do + disks+="/dev/"$(basename "$sd") + disks+=" " + done + + use_mq=$(cat /sys/module/scsi_mod/parameters/use_blk_mq) + if [[ $use_mq = "Y" ]]; then + scheds=("none" "mq-deadline" "kyber") + else + scheds=("noop" "deadline" "cfq") + fi + + fio_jobs="" + cnt=0 + for sd in $disks; do + cnt=$((cnt+1)) + fio_jobs=$fio_jobs" --name=job1 --filename=$sd: " + dev_name=$(basename "$sd") + q_path=/sys/block/$dev_name/queue + + sched_idx=$((cnt % ${#scheds[@]})) + echo "${scheds[$sched_idx]}" > "$q_path/scheduler" + echo $cnt > "$q_path/../device/queue_depth" + done + + fio --rw=randread --size=128G --direct=1 --ioengine=libaio \ + --iodepth=2048 --numjobs=$nr_fio_jobs --bs=4k \ + --group_reporting=1 --group_reporting=1 --runtime=$runtime \ + --loops=10000 "$fio_jobs" > "$FULL" 2>&1 & + + sleep 7 + for sd in $disks; do + dev_name=$(basename "$sd") + dpath=/sys/block/$dev_name/device + [ -f "$dpath/delete" ] && echo 1 > "$dpath/delete" + done + + wait +} + + +test() { + echo "Running ${TEST_NAME}" + + scsi_debug_stress_remove + + echo "Test complete" +} diff --git a/tests/block/022.out b/tests/block/022.out new file mode 100644 index 0000000..14d43cb --- /dev/null +++ b/tests/block/022.out @@ -0,0 +1,2 @@ +Running block/022 +Test complete
This test exposed a race condition with shutting down a request_queue and the new blkg association. The issue ended up being that while the request_queue will just start failing requests, blkg destruction sets the q->root_blkg to %NULL. This caused a NPE when trying to reference it. So to help prevent this from happening again, integrate Ming's test into blktests so that it can more easily be ran. Signed-off-by: Dennis Zhou <dennis@kernel.org> Cc: Ming Lei <ming.lei@redhat.com> --- tests/block/022 | 96 +++++++++++++++++++++++++++++++++++++++++++++ tests/block/022.out | 2 + 2 files changed, 98 insertions(+) create mode 100755 tests/block/022 create mode 100644 tests/block/022.out