From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-gh0-f180.google.com ([209.85.160.180]:46807 "EHLO mail-gh0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754614Ab2EaA6v convert rfc822-to-8bit (ORCPT ); Wed, 30 May 2012 20:58:51 -0400 Received: by ghbz12 with SMTP id z12so457007ghb.11 for ; Wed, 30 May 2012 17:58:50 -0700 (PDT) MIME-Version: 1.0 From: Sebastian Jensen Date: Thu, 31 May 2012 02:58:29 +0200 Message-ID: Subject: Task blocked, happens almost daily during heavy disk I/O To: linux-btrfs Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hey guys, (first of all, please include me in the re as I am not subscribed to the list) For the past few months, I've had issues with my two BTRFS drives during heavy disk I/O, often resulting in my server not being connectable via SSH and I have to reboot it manually by pulling the power plug. This is very annoying, and I fear for the almost 4TB data I have laying around on these 2 drives being lost some day, because I have to restart an unsynced fs. Today I managed to grab a dmesg output, sometimes I get a task blocked, and sometimes I get a kernel BUG error in dmesg, although the former tends to be the most common. I've yet to be unable to grab a readable screencap of the BUG reports, so I'll follow up with that as soon as I get one of those - both incidents block writing to the FS. Here is the output (as you can see the system has been running for less than half a day): [37590.706230] INFO: task flush-btrfs-1:390 blocked for more than 120 seconds. [37590.706249] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [37590.706261] flush-btrfs-1 D ffff8801d32ffa18 0 390 2 0x00000000 [37590.706267] ffff8801d32ff970 0000000000000046 ffff8801d510d800 ffff8801d32fffd8 [37590.706273] ffff8801d32fffd8 ffff8801d32fffd8 ffff8801d6439800 ffff8801d510d800 [37590.706278] ffff8801d32ff940 ffffffffa00c39e1 0000000000000000 ffff880100000050 [37590.706283] Call Trace: [37590.706311] [] ? run_delalloc_range+0x191/0x3a0 [btrfs] [37590.706317] [] ? read_tsc+0x9/0x20 [37590.706322] [] ? ktime_get_ts+0xb0/0xf0 [37590.706327] [] ? __lock_page+0x70/0x70 [37590.706332] [] schedule+0x3f/0x60 [37590.706336] [] io_schedule+0x8f/0xd0 [37590.706339] [] sleep_on_page+0xe/0x20 [37590.706343] [] __wait_on_bit_lock+0x5b/0xc0 [37590.706347] [] __lock_page+0x67/0x70 [37590.706353] [] ? autoremove_wake_function+0x40/0x40 [37590.706369] [] extent_write_cache_pages.isra.22.constprop.35+0x221/0x3f0 [btrfs] [37590.706385] [] extent_writepages+0x45/0x60 [btrfs] [37590.706400] [] ? btrfs_writepage+0x70/0x70 [btrfs] [37590.706405] [] ? bit_waitqueue+0x14/0xc0 [37590.706420] [] btrfs_writepages+0x28/0x30 [btrfs] [37590.706424] [] do_writepages+0x22/0x50 [37590.706430] [] writeback_single_inode+0x113/0x3b0 [37590.706435] [] writeback_sb_inodes+0x1d2/0x2b0 [37590.706440] [] __writeback_inodes_wb+0x9f/0xd0 [37590.706445] [] wb_writeback+0x313/0x340 [37590.706448] [] wb_do_writeback+0x268/0x270 [37590.706452] [] bdi_writeback_thread+0x93/0x2d0 [37590.706456] [] ? wb_do_writeback+0x270/0x270 [37590.706460] [] kthread+0x93/0xa0 [37590.706465] [] kernel_thread_helper+0x4/0x10 [37590.706470] [] ? kthread_freezable_should_stop+0x70/0x70 [37590.706473] [] ? gs_change+0x13/0x13 uname -r: 3.3.7-1-ARCH Regards -- Sebastian J.