Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752409AbbGRQ2q (ORCPT ); Sat, 18 Jul 2015 12:28:46 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:36121 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751343AbbGRQ2p (ORCPT ); Sat, 18 Jul 2015 12:28:45 -0400 From: Akinobu Mita To: linux-kernel@vger.kernel.org Cc: Akinobu Mita , Jens Axboe , Ming Lei , Tejun Heo , Keith Busch Subject: [PATCH v3 0/7] blk-mq: fix race conditions on cpu hotplug handling Date: Sun, 19 Jul 2015 01:28:16 +0900 Message-Id: <1437236903-31617-1-git-send-email-akinobu.mita@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1884 Lines: 56 This patchset addresses several race conditions on cpu hotplug handling for blk-mq. All problems can be reproducible by the following script. while true; do echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online done & while true; do modprobe -r null_blk modprobe null_blk queue_mode=2 irqmode=1 sleep 0.1 done * Changes from v2 - Add regression fix for hctx->tags->cpumask - Remove BLK_MQ_F_SYSFS_UP per-hctx flag and use mq_sysfs_init_done per-queue flag instead with appropriate locking in order to keep track of 'mq' sysfs entry's life - Add comments on non-trivial stuffs, suggested by Ming * Changes from v1 - Release q->mq_map in blk_mq_release() - Fix deadlock when reading cpu_list - Fix race freeze and unfreeze Akinobu Mita (7): blk-mq: avoid access hctx->tags->cpumask before allocation blk-mq: fix sysfs registration/unregistration race blk-mq: Fix use after of free q->mq_map blk-mq: fix q->mq_usage_counter access race blk-mq: avoid inserting requests before establishing new mapping blk-mq: fix freeze queue race blk-mq: fix deadlock when reading cpu_list block/blk-core.c | 1 + block/blk-mq-cpumap.c | 9 +++-- block/blk-mq-sysfs.c | 36 ++++++++++++------ block/blk-mq.c | 100 +++++++++++++++++++++++++++++++++++++------------ block/blk-mq.h | 3 +- include/linux/blk-mq.h | 1 - include/linux/blkdev.h | 8 ++++ 7 files changed, 116 insertions(+), 42 deletions(-) Cc: Jens Axboe Cc: Ming Lei Cc: Tejun Heo Cc: Keith Busch -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/