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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C183C64E75 for ; Tue, 17 Nov 2020 14:04:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A89820729 for ; Tue, 17 Nov 2020 14:04:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rIl1mGtL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731500AbgKQOEQ (ORCPT ); Tue, 17 Nov 2020 09:04:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:40082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729511AbgKQNKm (ORCPT ); Tue, 17 Nov 2020 08:10:42 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C5D602468F; Tue, 17 Nov 2020 13:10:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605618641; bh=4MWjxL41VJlyoglMYG/I/ktiUlwPkSDhz9VK7vITy18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rIl1mGtLQjDyilUiv3t0eZpxE0lBixGk7zVND7pdi+5BDR1GjkJgdE5r6NFh/72zF vEK7oW8MPYXyHQDU74StLiO4umsVAjJB2zhj8UdpQmLmstVBU4df16YMMczJcQaCek IjFL7phN0LSIeIiGaSoD8B2puDQuZpxJufp56CP0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josef Bacik , Johannes Thumshirn , David Sterba , Sasha Levin Subject: [PATCH 4.9 06/78] btrfs: reschedule when cloning lots of extents Date: Tue, 17 Nov 2020 14:04:32 +0100 Message-Id: <20201117122109.413113375@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122109.116890262@linuxfoundation.org> References: <20201117122109.116890262@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Thumshirn [ Upstream commit 6b613cc97f0ace77f92f7bc112b8f6ad3f52baf8 ] We have several occurrences of a soft lockup from fstest's generic/175 testcase, which look more or less like this one: watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [xfs_io:10030] Kernel panic - not syncing: softlockup: hung tasks CPU: 0 PID: 10030 Comm: xfs_io Tainted: G L 5.9.0-rc5+ #768 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0x77/0xa0 panic+0xfa/0x2cb watchdog_timer_fn.cold+0x85/0xa5 ? lockup_detector_update_enable+0x50/0x50 __hrtimer_run_queues+0x99/0x4c0 ? recalibrate_cpu_khz+0x10/0x10 hrtimer_run_queues+0x9f/0xb0 update_process_times+0x28/0x80 tick_handle_periodic+0x1b/0x60 __sysvec_apic_timer_interrupt+0x76/0x210 asm_call_on_stack+0x12/0x20 sysvec_apic_timer_interrupt+0x7f/0x90 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:btrfs_tree_unlock+0x91/0x1a0 [btrfs] RSP: 0018:ffffc90007123a58 EFLAGS: 00000282 RAX: ffff8881cea2fbe0 RBX: ffff8881cea2fbe0 RCX: 0000000000000000 RDX: ffff8881d23fd200 RSI: ffffffff82045220 RDI: ffff8881cea2fba0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000032 R10: 0000160000000000 R11: 0000000000001000 R12: 0000000000001000 R13: ffff8882357fd5b0 R14: ffff88816fa76e70 R15: ffff8881cea2fad0 ? btrfs_tree_unlock+0x15b/0x1a0 [btrfs] btrfs_release_path+0x67/0x80 [btrfs] btrfs_insert_replace_extent+0x177/0x2c0 [btrfs] btrfs_replace_file_extents+0x472/0x7c0 [btrfs] btrfs_clone+0x9ba/0xbd0 [btrfs] btrfs_clone_files.isra.0+0xeb/0x140 [btrfs] ? file_update_time+0xcd/0x120 btrfs_remap_file_range+0x322/0x3b0 [btrfs] do_clone_file_range+0xb7/0x1e0 vfs_clone_file_range+0x30/0xa0 ioctl_file_clone+0x8a/0xc0 do_vfs_ioctl+0x5b2/0x6f0 __x64_sys_ioctl+0x37/0xa0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f87977fc247 RSP: 002b:00007ffd51a2f6d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f87977fc247 RDX: 00007ffd51a2f710 RSI: 000000004020940d RDI: 0000000000000003 RBP: 0000000000000004 R08: 00007ffd51a79080 R09: 0000000000000000 R10: 00005621f11352f2 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00005621f128b958 R15: 0000000080000000 Kernel Offset: disabled ---[ end Kernel panic - not syncing: softlockup: hung tasks ]--- All of these lockup reports have the call chain btrfs_clone_files() -> btrfs_clone() in common. btrfs_clone_files() calls btrfs_clone() with both source and destination extents locked and loops over the source extent to create the clones. Conditionally reschedule in the btrfs_clone() loop, to give some time back to other processes. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/ioctl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 981091bd6c3c4..ebca009030c3a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3854,6 +3854,8 @@ process_slot: ret = -EINTR; goto out; } + + cond_resched(); } ret = 0; -- 2.27.0