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 <[email protected]> > Cc: Ming Lei <[email protected]> > --- > 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
