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 <[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
Thanks Ming! I'll post a v2 update for this patch. Thanks, Dennis
