On Thu, Dec 13, 2018 at 01:28:44PM -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@xxxxxxxxxx> > Cc: Ming Lei <ming.lei@xxxxxxxxxx> > --- > v2: > - Change scheduler retrieving logic based on Ming's comment > > tests/block/022 | 90 +++++++++++++++++++++++++++++++++++++++++++++ > tests/block/022.out | 2 + > 2 files changed, 92 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..84336e0 > --- /dev/null > +++ b/tests/block/022 > @@ -0,0 +1,90 @@ > +#!/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 > + > + 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/$dev_name/queue > + > + scheds=($(sed 's/[][]//g' "$q_path/scheduler")) > + sched_idx=$((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 > -- > 2.17.1 > Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> thanks, Ming