Kernel 3.3.0, 64bit. Reproduce: mkfs.btrfs /dev/foo -s 16k -l 16k -n16k mount /dev/foo /mnt/foo cd /mnt/foo btrfs su create test hangs hard here, any attempt to access that fs also hangs hard.
Workaround: Don't do it. :) If it makes a difference, it was a logical volume on top of MD, not a raw partition. It also may be more than just subvolume create that locks up ran across this entirely by accident, I was creating a test partition to see if raising my sector size had a performance impact. [ 236.386751] btrfs: disk space caching is enabled [ 480.936040] INFO: task btrfs-transacti:3325 blocked for more than 120 seconds. [ 480.936082] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 480.936121] btrfs-transacti D ffff88022fc12380 0 3325 2 0x00000000 [ 480.936126] ffff880213ddbd80 0000000000000046 ffff880218410780 0000000000012380 [ 480.936131] ffff880213ddbfd8 ffff880213dda000 0000000000012380 0000000000004000 [ 480.936135] ffff880213ddbfd8 0000000000012380 ffffffff81945020 ffff880218410780 [ 480.936139] Call Trace: [ 480.936147] [<ffffffff8168d33a>] schedule+0x3a/0x50 [ 480.936151] [<ffffffff8134d7dd>] wait_current_trans.clone.22+0x8d/0xf0 [ 480.936155] [<ffffffff81055390>] ? wake_up_bit+0x40/0x40 [ 480.936158] [<ffffffff8134d862>] ? join_transaction.clone.24+0x22/0x270 [ 480.936162] [<ffffffff8134edc8>] start_transaction+0x1f8/0x300 [ 480.936165] [<ffffffff8134ef20>] btrfs_join_transaction+0x10/0x20 [ 480.936168] [<ffffffff81346f7a>] transaction_kthread+0x14a/0x2a0 [ 480.936171] [<ffffffff81346e30>] ? btrfs_alloc_root+0x40/0x40 [ 480.936173] [<ffffffff81346e30>] ? btrfs_alloc_root+0x40/0x40 [ 480.936176] [<ffffffff81346e30>] ? btrfs_alloc_root+0x40/0x40 [ 480.936179] [<ffffffff81054e46>] kthread+0x96/0xa0 [ 480.936183] [<ffffffff816970c4>] kernel_thread_helper+0x4/0x10 [ 480.936186] [<ffffffff8168e6ca>] ? retint_restore_args+0xe/0xe [ 480.936189] [<ffffffff81054db0>] ? kthread_freezable_should_stop+0x60/0x60 [ 480.936192] [<ffffffff816970c0>] ? gs_change+0xb/0xb [ 480.936410] INFO: task flush-btrfs-5:3329 blocked for more than 120 seconds. [ 480.936446] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 480.936484] flush-btrfs-5 D ffff88022fc12380 0 3329 2 0x00000000 [ 480.936488] ffff880215105980 0000000000000046 ffff880213de27c0 0000000000012380 [ 480.936492] ffff880215105fd8 ffff880215104000 0000000000012380 0000000000004000 [ 480.936496] ffff880215105fd8 0000000000012380 ffffffff81945020 ffff880213de27c0 [ 480.936499] Call Trace: [ 480.936503] [<ffffffff810ce096>] ? get_page_from_freelist+0x336/0x790 [ 480.936506] [<ffffffff810c6630>] ? __lock_page+0x70/0x70 [ 480.936509] [<ffffffff81071488>] ? ktime_get_ts+0xa8/0xe0 [ 480.936512] [<ffffffff810c6630>] ? __lock_page+0x70/0x70 [ 480.936515] [<ffffffff8168d33a>] schedule+0x3a/0x50 [ 480.936518] [<ffffffff8168d3d7>] io_schedule+0x87/0xd0 [ 480.936521] [<ffffffff810c6639>] sleep_on_page+0x9/0x10 [ 480.936523] [<ffffffff8168b772>] __wait_on_bit_lock+0x52/0xb0 [ 480.936526] [<ffffffff810c6622>] __lock_page+0x62/0x70 [ 480.936529] [<ffffffff810553d0>] ? autoremove_wake_function+0x40/0x40 [ 480.936532] [<ffffffff8136cdfe>] extent_write_cache_pages.clone.18.clone.29+0x1fe/0x3d0 [ 480.936536] [<ffffffff8136d233>] extent_writepages+0x43/0x60 [ 480.936539] [<ffffffff813525f0>] ? uncompress_inline.clone.36+0x1c0/0x1c0 [ 480.936542] [<ffffffff81055264>] ? bit_waitqueue+0x14/0xd0 [ 480.936546] [<ffffffff81351e22>] btrfs_writepages+0x22/0x30 [ 480.936548] [<ffffffff810d133c>] do_writepages+0x1c/0x30 [ 480.936552] [<ffffffff8113d4f2>] writeback_single_inode+0x102/0x320 [ 480.936555] [<ffffffff8113db80>] writeback_sb_inodes+0x1f0/0x2b0 [ 480.936558] [<ffffffff8113e0d6>] __writeback_inodes_wb+0x96/0xc0 [ 480.936560] [<ffffffff8113e573>] wb_writeback+0x233/0x2c0 [ 480.936563] [<ffffffff8113ee5e>] wb_do_writeback+0x14e/0x200 [ 480.936566] [<ffffffff8113ef10>] ? wb_do_writeback+0x200/0x200 [ 480.936569] [<ffffffff8113efaa>] bdi_writeback_thread+0x9a/0x250 [ 480.936572] [<ffffffff8113ef10>] ? wb_do_writeback+0x200/0x200 [ 480.936574] [<ffffffff8113ef10>] ? wb_do_writeback+0x200/0x200 [ 480.936577] [<ffffffff81054e46>] kthread+0x96/0xa0 [ 480.936580] [<ffffffff816970c4>] kernel_thread_helper+0x4/0x10 [ 480.936583] [<ffffffff8168e6ca>] ? retint_restore_args+0xe/0xe [ 480.936587] [<ffffffff81054db0>] ? kthread_freezable_should_stop+0x60/0x60 [ 480.936590] [<ffffffff816970c0>] ? gs_change+0xb/0xb [ 600.936181] INFO: task btrfs:3327 blocked for more than 120 seconds. [ 600.936214] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 600.936250] btrfs D ffff88022fd12380 0 3327 1 0x00000004 [ 600.936254] ffff880213e334d8 0000000000000082 ffff880213e24200 0000000000012380 [ 600.936257] ffff880213e33fd8 ffff880213e32000 0000000000012380 0000000000004000 [ 600.936261] ffff880213e33fd8 0000000000012380 ffff8802270f0300 ffff880213e24200 [ 600.936264] Call Trace: [ 600.936267] [<ffffffff813c4f44>] ? submit_bio+0x84/0x110 [ 600.936271] [<ffffffff81375bcb>] ? btrfs_map_bio+0x15b/0x230 [ 600.936275] [<ffffffff81071488>] ? ktime_get_ts+0xa8/0xe0 [ 600.936279] [<ffffffff810c6630>] ? __lock_page+0x70/0x70 [ 600.936281] [<ffffffff8168d33a>] schedule+0x3a/0x50 [ 600.936284] [<ffffffff8168d3d7>] io_schedule+0x87/0xd0 [ 600.936287] [<ffffffff810c6639>] sleep_on_page+0x9/0x10 [ 600.936289] [<ffffffff8168b8a7>] __wait_on_bit+0x57/0x80 [ 600.936292] [<ffffffff810c685e>] wait_on_page_bit+0x6e/0x80 [ 600.936294] [<ffffffff810553d0>] ? autoremove_wake_function+0x40/0x40 [ 600.936298] [<ffffffff8136ce85>] extent_write_cache_pages.clone.18.clone.29+0x285/0x3d0 [ 600.936302] [<ffffffff8136d233>] extent_writepages+0x43/0x60 [ 600.936306] [<ffffffff813525f0>] ? uncompress_inline.clone.36+0x1c0/0x1c0 [ 600.936309] [<ffffffff81351e22>] btrfs_writepages+0x22/0x30 [ 600.936311] [<ffffffff810d133c>] do_writepages+0x1c/0x30 [ 600.936314] [<ffffffff810c7318>] __filemap_fdatawrite_range+0x88/0x90 [ 600.936317] [<ffffffff810c81ba>] filemap_fdatawrite+0x1a/0x20 [ 600.936320] [<ffffffff810c81f5>] filemap_write_and_wait+0x35/0x60 [ 600.936323] [<ffffffff813874a7>] __btrfs_write_out_cache+0x8c7/0xb10 [ 600.936326] [<ffffffff8137e9c3>] ? btrfs_tree_unlock+0x23/0xb0 [ 600.936331] [<ffffffff8133d66c>] ? btrfs_run_delayed_refs+0x27c/0x490 [ 600.936334] [<ffffffff81387799>] btrfs_write_out_cache+0xa9/0xe0 [ 600.936337] [<ffffffff8133dccf>] btrfs_write_dirty_block_groups+0x44f/0x520 [ 600.936340] [<ffffffff8134cebd>] commit_cowonly_roots+0x10d/0x1d0 [ 600.936343] [<ffffffff8134e47b>] btrfs_commit_transaction+0x3eb/0x860 [ 600.936346] [<ffffffff81055390>] ? wake_up_bit+0x40/0x40 [ 600.936349] [<ffffffff81378f43>] create_subvol+0x493/0x4d0 [ 600.936353] [<ffffffff8137a6ff>] btrfs_mksubvol+0x16f/0x390 [ 600.936356] [<ffffffff8137aa55>] btrfs_ioctl_snap_create_transid+0x135/0x190 [ 600.936359] [<ffffffff8137ab01>] btrfs_ioctl_snap_create+0x51/0x70 [ 600.936362] [<ffffffff8137d510>] btrfs_ioctl+0x320/0x1220 [ 600.936366] [<ffffffff810ea769>] ? handle_mm_fault+0x159/0x2b0 [ 600.936369] [<ffffffff81691b94>] ? do_page_fault+0x1e4/0x490 [ 600.936373] [<ffffffff81128546>] do_vfs_ioctl+0x96/0x4f0 [ 600.936377] [<ffffffff813ea41a>] ? trace_hardirqs_off_thunk+0x3a/0x6c [ 600.936380] [<ffffffff81128a29>] sys_ioctl+0x89/0x90 [ 600.936383] [<ffffffff81695ee2>] system_call_fastpath+0x16/0x1b -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
