From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48490 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932761AbcIENzb (ORCPT ); Mon, 5 Sep 2016 09:55:31 -0400 Subject: Patch "dm round robin: do not use this_cpu_ptr() without having preemption disabled" has been added to the 4.7-stable tree To: snitzer@redhat.com, axboe@kernel.dk, bblock@linux.vnet.ibm.com, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 05 Sep 2016 15:55:08 +0200 Message-ID: <1473083708120122@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dm round robin: do not use this_cpu_ptr() without having preemption disabled to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-round-robin-do-not-use-this_cpu_ptr-without-having-preemption-disabled.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 802934b2cfde463b72cc1b9bc1c081895a90be53 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 5 Aug 2016 12:29:06 -0400 Subject: dm round robin: do not use this_cpu_ptr() without having preemption disabled From: Mike Snitzer commit 802934b2cfde463b72cc1b9bc1c081895a90be53 upstream. Use local_irq_save() to disable preemption before calling this_cpu_ptr(). Reported-by: Benjamin Block Fixes: b0b477c7e0dd ("dm round robin: use percpu 'repeat_count' and 'current_path'") Suggested-by: Jens Axboe Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-round-robin.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/md/dm-round-robin.c +++ b/drivers/md/dm-round-robin.c @@ -210,14 +210,17 @@ static struct dm_path *rr_select_path(st struct path_info *pi = NULL; struct dm_path *current_path = NULL; + local_irq_save(flags); current_path = *this_cpu_ptr(s->current_path); if (current_path) { percpu_counter_dec(&s->repeat_count); - if (percpu_counter_read_positive(&s->repeat_count) > 0) + if (percpu_counter_read_positive(&s->repeat_count) > 0) { + local_irq_restore(flags); return current_path; + } } - spin_lock_irqsave(&s->lock, flags); + spin_lock(&s->lock); if (!list_empty(&s->valid_paths)) { pi = list_entry(s->valid_paths.next, struct path_info, list); list_move_tail(&pi->list, &s->valid_paths); Patches currently in stable-queue which might be from snitzer@redhat.com are queue-4.7/dm-round-robin-do-not-use-this_cpu_ptr-without-having-preemption-disabled.patch