From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6F14C433F5 for ; Mon, 13 Dec 2021 12:40:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236822AbhLMMkG (ORCPT ); Mon, 13 Dec 2021 07:40:06 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:45978 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231831AbhLMMkE (ORCPT ); Mon, 13 Dec 2021 07:40:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1639399204; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lQVfgXvUEecz1ew4Duj5H2gRLrd/qk8IbwHLmWuD9+M=; b=YcYMb3Ooq5ul+xqjDjnfPVo0Xo8nhSp0Tu6HomjAtRKBb6cpIvFIMsjFTLGlgMPwjyT0sw R0d41OjBI5mTQRZHmUvocLRKVNt7cTyrdOv1dw9nmlhlKF4Lj3ce8hJn18gwarwZqvX1qZ hRGce/yvQbN+9VEtCJpKj0SnCaHMIZQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-573-Z9Exka3VP_ezK-DSLUs5Dw-1; Mon, 13 Dec 2021 07:40:03 -0500 X-MC-Unique: Z9Exka3VP_ezK-DSLUs5Dw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C32461926DA3; Mon, 13 Dec 2021 12:40:01 +0000 (UTC) Received: from wcosta.com (ovpn-116-142.gru2.redhat.com [10.97.116.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 11895694D8; Mon, 13 Dec 2021 12:39:53 +0000 (UTC) From: Wander Lairson Costa To: linux-kernel@vger.kernel.org Cc: Steven Rostedt , Thomas Gleixner , Sebastian Andrzej Siewior , linux-rt-users@vger.kernel.org, Wander Lairson Costa Subject: [PATCH v2 1/2] block: Avoid sleeping function called from invalid context bug Date: Mon, 13 Dec 2021 09:37:36 -0300 Message-Id: <20211213123737.9147-2-wander@redhat.com> In-Reply-To: <20211213123737.9147-1-wander@redhat.com> References: <20211213123737.9147-1-wander@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This was caught during QA test: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:942 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 243401, name: sed INFO: lockdep is turned off. Preemption disabled at: [] blk_cgroup_bio_start+0x28/0xd0 CPU: 2 PID: 243401 Comm: sed Kdump: loaded Not tainted 4.18.0-353.rt7.138.el8.x86_64+debug #1 Hardware name: HP ProLiant DL380 Gen9, BIOS P89 05/06/2015 Call Trace: dump_stack+0x5c/0x80 ___might_sleep.cold.89+0xf5/0x109 rt_spin_lock+0x3e/0xd0 ? __blk_add_trace+0x428/0x4b0 __blk_add_trace+0x428/0x4b0 blk_add_trace_bio+0x16e/0x1c0 generic_make_request_checks+0x7e8/0x8c0 generic_make_request+0x3c/0x420 ? membarrier_private_expedited+0xd0/0x2b0 ? lock_release+0x1ca/0x450 ? submit_bio+0x3c/0x160 ? _raw_spin_unlock_irqrestore+0x3c/0x80 submit_bio+0x3c/0x160 ? rt_mutex_futex_unlock+0x66/0xa0 iomap_submit_ioend.isra.36+0x4a/0x70 xfs_vm_writepages+0x65/0x90 [xfs] do_writepages+0x41/0xe0 ? rt_mutex_futex_unlock+0x66/0xa0 __filemap_fdatawrite_range+0xce/0x110 xfs_release+0x11c/0x160 [xfs] __fput+0xd5/0x270 task_work_run+0xa1/0xd0 exit_to_usermode_loop+0x14d/0x160 do_syscall_64+0x23b/0x240 entry_SYSCALL_64_after_hwframe+0x6a/0xdf We replace the get/put_cpu() call by get/put_cpu_light to avoid this bug. Signed-off-by: Wander Lairson Costa --- block/blk-cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 663aabfeba18..0a532bb3003c 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1911,7 +1911,7 @@ void blk_cgroup_bio_start(struct bio *bio) struct blkg_iostat_set *bis; unsigned long flags; - cpu = get_cpu(); + cpu = get_cpu_light(); bis = per_cpu_ptr(bio->bi_blkg->iostat_cpu, cpu); flags = u64_stats_update_begin_irqsave(&bis->sync); @@ -1928,7 +1928,7 @@ void blk_cgroup_bio_start(struct bio *bio) u64_stats_update_end_irqrestore(&bis->sync, flags); if (cgroup_subsys_on_dfl(io_cgrp_subsys)) cgroup_rstat_updated(bio->bi_blkg->blkcg->css.cgroup, cpu); - put_cpu(); + put_cpu_light(); } static int __init blkcg_init(void) -- 2.27.0