On 08/06/2014 10:43 AM, Martin Steigerwald wrote: > Am Mittwoch, 6. August 2014, 09:35:51 schrieb Chris Mason: >> On 08/06/2014 06:21 AM, Martin Steigerwald wrote: >>>> I think this should go to stable. Thanks, Liu. >> >> I'm definitely tagging this for stable. >> >>> Unfortunately this fix does not seem to fix all lockups. >> >> The traces below are a little different, could you please send the whole >> file? > > Will paste it at the end. [90496.156016] kworker/u8:14 D ffff880044e38540 0 21050 2 0x00000000 [90496.157683] Workqueue: btrfs-delalloc normal_work_helper [btrfs] [90496.159320] ffff88022880f990 0000000000000002 ffff880407f649b0 ffff88022880ffd8 [90496.160997] ffff880044e38000 0000000000013040 ffff880044e38000 7fffffffffffffff [90496.162686] ffff880301383aa0 0000000000000002 ffffffff814705d0 ffff880301383a98 [90496.164360] Call Trace: [90496.166028] [<ffffffff814705d0>] ? michael_mic.part.6+0x21/0x21 [90496.167854] [<ffffffff81470fd0>] schedule+0x64/0x66 [90496.169574] [<ffffffff814705ff>] schedule_timeout+0x2f/0x114 [90496.171221] [<ffffffff8106479a>] ? wake_up_process+0x2f/0x32 [90496.172867] [<ffffffff81062c3b>] ? get_parent_ip+0xd/0x3c [90496.174472] [<ffffffff81062ce5>] ? preempt_count_add+0x7b/0x8e [90496.176053] [<ffffffff814717f3>] __wait_for_common+0x11e/0x163 [90496.177619] [<ffffffff814717f3>] ? __wait_for_common+0x11e/0x163 [90496.179173] [<ffffffff810647aa>] ? wake_up_state+0xd/0xd [90496.180728] [<ffffffff81471857>] wait_for_completion+0x1f/0x21 [90496.182285] [<ffffffffc044e3b3>] btrfs_async_run_delayed_refs+0xbf/0xd9 [btrfs] [90496.183833] [<ffffffffc04624e1>] __btrfs_end_transaction+0x2b6/0x2ec [btrfs] [90496.185380] [<ffffffffc0462522>] btrfs_end_transaction+0xb/0xd [btrfs] [90496.186940] [<ffffffffc0451742>] find_free_extent+0x8a9/0x976 [btrfs] [90496.189464] [<ffffffffc0451990>] btrfs_reserve_extent+0x6f/0x119 [btrfs] [90496.191326] [<ffffffffc0466b45>] cow_file_range+0x1a6/0x377 [btrfs] [90496.193080] [<ffffffffc047adc4>] ? extent_write_locked_range+0x10c/0x11e [btrfs] [90496.194659] [<ffffffffc04677e4>] submit_compressed_extents+0x100/0x412 [btrfs] [90496.196225] [<ffffffff8120e344>] ? debug_smp_processor_id+0x17/0x19 [90496.197776] [<ffffffffc0467b78>] async_cow_submit+0x82/0x87 [btrfs] [90496.199383] [<ffffffffc048644b>] normal_work_helper+0x153/0x224 [btrfs] [90496.200944] [<ffffffff81052d8c>] process_one_work+0x16f/0x2b8 [90496.202483] [<ffffffff81053636>] worker_thread+0x27b/0x32e [90496.204000] [<ffffffff810533bb>] ? cancel_delayed_work_sync+0x10/0x10 [90496.205514] [<ffffffff81058012>] kthread+0xb2/0xba [90496.207040] [<ffffffff81470000>] ? ap_handle_dropped_data+0xf/0xc8 [90496.208565] [<ffffffff81057f60>] ? __kthread_parkme+0x62/0x62 [90496.210096] [<ffffffff81473f6c>] ret_from_fork+0x7c/0xb0 [90496.211618] [<ffffffff81057f60>] ? __kthread_parkme+0x62/0x62 Ok, this should explain the hang. submit_compressed_extents is calling cow_file_range with a locked page. cow_file_range is trying to find a free extent and in the process is calling btrfs_end_transaction, which is running the async delayed refs, which is trying to write dirty pages, which is waiting for your locked page. I should be able to reproduce this ;) -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
