From patchwork Tue Sep 22 08:27:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 11791833 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 284DB112C for ; Tue, 22 Sep 2020 08:28:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBC78239E5 for ; Tue, 22 Sep 2020 08:28:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="AU9Rtd/M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726789AbgIVI2E (ORCPT ); Tue, 22 Sep 2020 04:28:04 -0400 Received: from esa5.hgst.iphmx.com ([216.71.153.144]:45254 "EHLO esa5.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726537AbgIVI2E (ORCPT ); Tue, 22 Sep 2020 04:28:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1600763285; x=1632299285; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=AQkOyEKRLSc+Vr3jY0wPdwR5EUwS2wbYEl2sfH05dwA=; b=AU9Rtd/MeZn8IxgKChQvwQHQrjx468B4PMsatSDZdx0M+D9VKdMGPQBs nf3Bsn2f4tA3ibFU572kiPqiFNtWaKX/Dh4yAt+z6aM24h+aBfnIIr6M9 aqPigSdmS8wERshJ+hwgcPJKHXPklW8855OVewgxGoXnah/hT1ZHWROMY 2qnEsRPSpIie1TCPhn95aWDZW1VNq3I3LW4HMgUK0nGlFQsA4JoOpvhgf MgyzvvR8m07U8HgSipAe+hW7r3X2Zo0+biMndug0lT1n777S/B5LLxEPn HvsR9MeE1Tnn0i6Q86JQSDI85kz3AdroTu+WYPpdeEkH4qTH8sHyh4lGN Q==; IronPort-SDR: slzkhDGyQWvGZFktBC0as25cukXJ73L6pggc6IWKFbOjhmDUHvfLA7OlWjlZQxrTNzO5bQ9aoH 4y+m005QVrCoV2MNxFx7F5b/4zNAE3TNezT9xeg454MPXX4F+sWMdQmF3EONEq5ilOHU2J+PkK MQ/ClDFjsT0IKFbCI+ZJX+CAT4ZpvaB9ieRKCrE2d0iSRqykRi4++mcUIitb0W73VabDiJR+Dr Gwa7hQJDhmlfpBg9F8AtteyIsnOZIsQP2x9a+X3PMdg/vZUM7C9/9V+lrGdXAgmiuFUP5hACFY 4bA= X-IronPort-AV: E=Sophos;i="5.77,290,1596470400"; d="scan'208";a="147982336" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 22 Sep 2020 16:28:04 +0800 IronPort-SDR: rq5SOrhPHZ1VnuXy2OyO96WjxFQRNxGJhqYZJxryNI1hOM1k2e0MbWN5qZtTKUYKQikytU9O0x But6VMxUjFsA== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2020 01:14:12 -0700 IronPort-SDR: 5SS+Ld5eLaUF3XpcuPgGBZAXx/vT4BrtOHplFInl4OxeZG/VzqtDMPyLtK1n9R1e7pJUajHTH3 fw6HsudZ5Q+Q== WDCIronportException: Internal Received: from unknown (HELO redsun60.ssa.fujisawa.hgst.com) ([10.149.66.36]) by uls-op-cesaip02.wdc.com with ESMTP; 22 Sep 2020 01:28:02 -0700 From: Johannes Thumshirn To: David Sterba Cc: linux-btrfs@vger.kernel.org, Johannes Thumshirn Subject: [PATCH v2] btrfs: reschedule when cloning lots of extents Date: Tue, 22 Sep 2020 17:27:29 +0900 Message-Id: <42f05219ee6dfd612fe38f0ec6209d5a2c6c23dc.1600763203.git.johannes.thumshirn@wdc.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org We have several occurrences of a soft lockup from xfstest's generic/175 test-case, 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] Code: 85 1e 01 00 00 c7 83 84 00 00 00 00 00 00 00 f0 83 44 24 fc 00 48 8b 83 10 01 00 00 48 8d bb d0 00 00 00 48 81 c3 10 01 00 00 <48> 39 d8 74 63 5b 31 c9 5d ba 01 00 00 00 be 03 00 00 00 41 5c e9 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 Code: 00 00 90 48 8b 05 49 8c 0c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 19 8c 0c 00 f7 d8 64 89 01 48 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. Signed-off-by: Johannes Thumshirn Reviewed-by: Josef Bacik --- Changes to v1: - Update changelog --- fs/btrfs/reflink.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c index 39b3269e5760..99aa87c08912 100644 --- a/fs/btrfs/reflink.c +++ b/fs/btrfs/reflink.c @@ -520,6 +520,8 @@ static int btrfs_clone(struct inode *src, struct inode *inode, ret = -EINTR; goto out; } + + cond_resched(); } ret = 0;