Hello, On a server running Linux kernel 3.8.4-1-ARCH I''m periodically getting the following warnings (see below) while copying data onto the filesystem. The setup is btrfs -> LUKS -> md raid5 -> several regular HDDs. Interested to know if anyone has any info on what might cause this and whether it''s harmful or not. Thanks, Kyle 00:00:33 kernel: INFO: task btrfs-endio-wri:1371 blocked for more than 120 seconds. 00:00:33 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 00:00:33 kernel: btrfs-endio-wri D ffff8801cb4ae2f8 0 1371 2 0x00000000 00:00:33 kernel: ffff88013b76dc98 0000000000000046 ffff8801d5ed0000 ffff88013b76dfd8 00:00:33 kernel: ffff88013b76dfd8 ffff88013b76dfd8 ffff8801d5cc0860 ffff8801d5ed0000 00:00:33 kernel: ffff88013b76dc18 ffffffff81014570 ffff8801dfdd3f80 0000000000000001 00:00:33 kernel: Call Trace: 00:00:33 kernel: [<ffffffff81014570>] ? __switch_to+0x120/0x4e0 00:00:33 kernel: [<ffffffff81088659>] ? finish_task_switch+0x49/0xe0 00:00:33 kernel: [<ffffffffa03f1888>] ? tree_insert+0x58/0x70 [btrfs] 00:00:33 kernel: [<ffffffffa03f11fb>] ? set_state_bits+0x4b/0x90 [btrfs] 00:00:33 kernel: [<ffffffff814d1d59>] schedule+0x29/0x70 00:00:33 kernel: [<ffffffffa03d8c25>] wait_current_trans.isra.28+0xa5/0xf0 [btrfs] 00:00:33 kernel: [<ffffffff8107bff0>] ? abort_exclusive_wait+0xb0/0xb0 00:00:33 kernel: [<ffffffffa03da418>] start_transaction+0x158/0x4a0 [btrfs] 00:00:33 kernel: [<ffffffffa03f3824>] ? lock_extent_bits+0x74/0xa0 [btrfs] 00:00:33 kernel: [<ffffffffa03da7d7>] btrfs_join_transaction+0x17/0x20 [btrfs] 00:00:33 kernel: [<ffffffffa03e2cca>] btrfs_finish_ordered_io+0x1aa/0x3f0 [btrfs] 00:00:33 kernel: [<ffffffffa03e2f25>] finish_ordered_fn+0x15/0x20 [btrfs] 00:00:33 kernel: [<ffffffffa040460d>] worker_loop+0x13d/0x570 [btrfs] 00:00:33 kernel: [<ffffffff814d1d09>] ? preempt_schedule+0x49/0x70 00:00:33 kernel: [<ffffffffa04044d0>] ? btrfs_queue_worker+0x320/0x320 [btrfs] 00:00:33 kernel: [<ffffffff8107b300>] kthread+0xc0/0xd0 00:00:33 kernel: [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pte_at+0x10/0x100 00:00:33 kernel: [<ffffffff8107b240>] ? kthread_freezable_should_stop+0x70/0x70 00:00:33 kernel: [<ffffffff814da76c>] ret_from_fork+0x7c/0xb0 00:00:33 kernel: [<ffffffff8107b240>] ? kthread_freezable_should_stop+0x70/0x70 00:00:33 kernel: INFO: task btrfs-endio-wri:1380 blocked for more than 120 seconds. 00:00:33 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 00:00:33 kernel: btrfs-endio-wri D ffff880193381850 0 1380 2 0x00000000 00:00:33 kernel: ffff88010cb5dc98 0000000000000046 ffff8801d5c87540 ffff88010cb5dfd8 00:00:33 kernel: ffff88010cb5dfd8 ffff88010cb5dfd8 ffff8801c4b629e0 ffff8801d5c87540 00:00:33 kernel: ffff88010cb5dc18 ffffffff81014570 ffff8801dfc93f80 0000000000000001 00:00:33 kernel: Call Trace: 00:00:33 kernel: [<ffffffff81014570>] ? __switch_to+0x120/0x4e0 00:00:33 kernel: [<ffffffff81088659>] ? finish_task_switch+0x49/0xe0 00:00:33 kernel: [<ffffffff81174758>] ? kmem_cache_free+0x38/0x1d0 00:00:33 kernel: [<ffffffffa03f22fe>] ? free_extent_state+0x1e/0x30 [btrfs] 00:00:33 kernel: [<ffffffffa03f1d24>] ? free_extent_state.part.33+0x34/0xb0 [btrfs] 00:00:33 kernel: [<ffffffff814d1d59>] schedule+0x29/0x70 00:00:33 kernel: [<ffffffffa03d8c25>] wait_current_trans.isra.28+0xa5/0xf0 [btrfs] 00:00:33 kernel: [<ffffffff8107bff0>] ? abort_exclusive_wait+0xb0/0xb0 00:00:33 kernel: [<ffffffffa03da418>] start_transaction+0x158/0x4a0 [btrfs] 00:00:33 kernel: [<ffffffffa03f3824>] ? lock_extent_bits+0x74/0xa0 [btrfs] 00:00:33 kernel: [<ffffffffa03da7d7>] btrfs_join_transaction+0x17/0x20 [btrfs] 00:00:33 kernel: [<ffffffffa03e2cca>] btrfs_finish_ordered_io+0x1aa/0x3f0 [btrfs] 00:00:33 kernel: [<ffffffffa03e2f25>] finish_ordered_fn+0x15/0x20 [btrfs] 00:00:33 kernel: [<ffffffffa040460d>] worker_loop+0x13d/0x570 [btrfs] 00:00:33 kernel: [<ffffffff814d1d09>] ? preempt_schedule+0x49/0x70 00:00:33 kernel: [<ffffffffa04044d0>] ? btrfs_queue_worker+0x320/0x320 [btrfs] 00:00:33 kernel: [<ffffffff8107b300>] kthread+0xc0/0xd0 00:00:33 kernel: [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pte_at+0x10/0x100 00:00:33 kernel: [<ffffffff8107b240>] ? kthread_freezable_should_stop+0x70/0x70 00:00:33 kernel: [<ffffffff814da76c>] ret_from_fork+0x7c/0xb0 00:00:33 kernel: [<ffffffff8107b240>] ? kthread_freezable_should_stop+0x70/0x70 06:00:32 kernel: INFO: task btrfs-endio-wri:4162 blocked for more than 120 seconds. 06:00:32 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 06:00:32 kernel: btrfs-endio-wri D ffff8801501e1940 0 4162 2 0x00000000 06:00:32 kernel: ffff8801501e1898 0000000000000046 ffff8801c9f410c0 ffff8801501e1fd8 06:00:32 kernel: ffff8801501e1fd8 ffff8801501e1fd8 ffffffff81815440 ffff8801c9f410c0 06:00:32 kernel: ffff8801501e1808 ffffffffa02b6783 ffff8801501e1808 0000000053135079 06:00:32 kernel: Call Trace: 06:00:32 kernel: [<ffffffffa02b6783>] ? dm_merge_bvec+0xb3/0x110 [dm_mod] 06:00:32 kernel: [<ffffffffa03fbfd8>] ? submit_stripe_bio+0x58/0x80 [btrfs] 06:00:32 kernel: [<ffffffffa0400b7f>] ? btrfs_map_bio+0x24f/0x400 [btrfs] 06:00:32 kernel: [<ffffffff8101c9e9>] ? read_tsc+0x9/0x20 06:00:32 kernel: [<ffffffff81123fd0>] ? __lock_page+0x70/0x70 06:00:32 kernel: [<ffffffff814d1d59>] schedule+0x29/0x70 06:00:32 kernel: [<ffffffff814d1e2f>] io_schedule+0x8f/0xd0 06:00:32 kernel: [<ffffffff81123fde>] sleep_on_page+0xe/0x20 06:00:32 kernel: [<ffffffff814cf870>] __wait_on_bit+0x60/0x90 06:00:32 kernel: [<ffffffff81124270>] wait_on_page_bit+0x80/0x90 06:00:32 kernel: [<ffffffff8107c030>] ? autoremove_wake_function+0x40/0x40 06:00:32 kernel: [<ffffffffa03f86c5>] read_extent_buffer_pages+0x335/0x370 [btrfs] 06:00:32 kernel: [<ffffffffa03d0c80>] ? verify_parent_transid+0x170/0x170 [btrfs] 06:00:32 kernel: [<ffffffffa03d29d1>] btree_read_extent_buffer_pages.constprop.117+0xb1/0x110 [btrfs] 06:00:32 kernel: [<ffffffffa03d324a>] read_tree_block+0x3a/0x50 [btrfs] 06:00:32 kernel: [<ffffffffa03b61b4>] read_block_for_search.isra.47+0x134/0x410 [btrfs] 06:00:32 kernel: [<ffffffffa03b593b>] ? generic_bin_search.constprop.49+0x6b/0x180 [btrfs] 06:00:32 kernel: [<ffffffffa03b86a4>] btrfs_search_slot+0x2b4/0x780 [btrfs] 06:00:32 kernel: [<ffffffffa041af8b>] ? tree_insert+0x7b/0xa0 [btrfs] 06:00:32 kernel: [<ffffffffa03cd436>] btrfs_lookup_csum+0x76/0x180 [btrfs] 06:00:32 kernel: [<ffffffffa03ce720>] btrfs_csum_file_blocks+0xd0/0x6c0 [btrfs] 06:00:32 kernel: [<ffffffffa03b332a>] ? btrfs_free_path+0x2a/0x40 [btrfs] 06:00:32 kernel: [<ffffffffa03dec2d>] ? insert_reserved_file_extent.constprop.58+0x8d/0x2c0 [btrfs] 06:00:32 kernel: [<ffffffffa03ede09>] ? try_merge_map+0x49/0x200 [btrfs] 06:00:32 kernel: [<ffffffffa03dd445>] add_pending_csums.isra.43+0x45/0x60 [btrfs] 06:00:32 kernel: [<ffffffffa03e2d5b>] btrfs_finish_ordered_io+0x23b/0x3f0 [btrfs] 06:00:32 kernel: [<ffffffffa03e2f25>] finish_ordered_fn+0x15/0x20 [btrfs] 06:00:32 kernel: [<ffffffffa040460d>] worker_loop+0x13d/0x570 [btrfs] 06:00:32 kernel: [<ffffffffa04044d0>] ? btrfs_queue_worker+0x320/0x320 [btrfs] 06:00:32 kernel: [<ffffffff8107b300>] kthread+0xc0/0xd0 06:00:33 kernel: [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pte_at+0x10/0x100 06:00:33 kernel: [<ffffffff8107b240>] ? kthread_freezable_should_stop+0x70/0x70 06:00:33 kernel: [<ffffffff814da76c>] ret_from_fork+0x7c/0xb0 06:00:33 kernel: [<ffffffff8107b240>] ? kthread_freezable_should_stop+0x70/0x70 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html