hello, I'm running into btrfs-transaction hang issue with below call trace from dmesg[1]. when this issue happens, all filesystem r/w access will be blocked and no response in terminal. I'm using Ubuntu raring(linux 3.2 kernel) 64bit kernel as below: Linux dpu-e6410 3.2.0-36-generic #57-Ubuntu SMP Tue Jan 8 21:44:52 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux is it a known issue? How to recover from such task hung status? Thanks! David [1] ---- [ 1080.532172] INFO: task tar:3368 blocked for more than 120 seconds. [ 1080.532178] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1080.532181] tar D ffff88043fc53ec0 0 3368 3269 0x00000000 [ 1080.532188] ffff8803fe42ddc8 0000000000000082 ffff88040d9745c0 ffff8803fe42dfd8 [ 1080.532194] ffff8803fe42dfd8 ffff8803fe42dfd8 ffff880429542e80 ffff88040d9745c0 [ 1080.532200] ffff880415321d00 ffff8804289241e8 ffff8804289241e8 0000000000000000 [ 1080.532206] Call Trace: [ 1080.532219] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1080.532257] [<ffffffffa00bf23d>] wait_current_trans.isra.28+0x9d/0x100 [btrfs] [ 1080.532264] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1080.532285] [<ffffffffa00c09a8>] start_transaction+0x158/0x460 [btrfs] [ 1080.532290] [<ffffffff811a3040>] ? kern_path_create+0x90/0x170 [ 1080.532310] [<ffffffffa00c0fe8>] btrfs_start_transaction+0x18/0x20 [btrfs] [ 1080.532330] [<ffffffffa00cd91e>] btrfs_mkdir+0x4e/0x1d0 [btrfs] [ 1080.532338] [<ffffffff812cefec>] ? security_inode_permission+0x1c/0x30 [ 1080.532343] [<ffffffff8119f3e6>] vfs_mkdir+0xa6/0x130 [ 1080.532348] [<ffffffff811a44ba>] sys_mkdirat+0xaa/0xf0 [ 1080.532353] [<ffffffff816d59dd>] system_call_fastpath+0x1a/0x1f [ 1200.532111] INFO: task btrfs-transacti:1076 blocked for more than 120 seconds. [ 1200.532117] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1200.532120] btrfs-transacti D ffff88043fc13ec0 0 1076 2 0x00000000 [ 1200.532127] ffff88041bb73d38 0000000000000046 ffff88042576ae80 ffff88041bb73fd8 [ 1200.532134] ffff88041bb73fd8 ffff88041bb73fd8 ffffffff81c15440 ffff88042576ae80 [ 1200.532139] ffff8804289a4800 ffff880409819130 ffff880415321d00 0000000000000000 [ 1200.532145] Call Trace: [ 1200.532159] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1200.532165] [<ffffffff816ca68c>] schedule_timeout+0x1ec/0x2b0 [ 1200.532205] [<ffffffffa00d6929>] ? btrfs_run_ordered_operations+0x2b9/0x2f0 [btrfs] [ 1200.532213] [<ffffffff81044b49>] ? default_spin_lock_flags+0x9/0x10 [ 1200.532235] [<ffffffffa00bfc8a>] btrfs_commit_transaction+0x38a/0xac0 [btrfs] [ 1200.532241] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1200.532261] [<ffffffffa00b8ecd>] transaction_kthread+0x1bd/0x240 [btrfs] [ 1200.532279] [<ffffffffa00b8d10>] ? write_dev_flush.part.107+0xc0/0xc0 [btrfs] [ 1200.532284] [<ffffffff8107d580>] kthread+0xc0/0xd0 [ 1200.532289] [<ffffffff8107d4c0>] ? kthread_create_on_node+0x120/0x120 [ 1200.532294] [<ffffffff816d592c>] ret_from_fork+0x7c/0xb0 [ 1200.532298] [<ffffffff8107d4c0>] ? kthread_create_on_node+0x120/0x120 [ 1200.532325] INFO: task tar:3368 blocked for more than 120 seconds. [ 1200.532327] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1200.532329] tar D ffff88043fc53ec0 0 3368 3269 0x00000000 [ 1200.532333] ffff8803fe42ddc8 0000000000000082 ffff88040d9745c0 ffff8803fe42dfd8 [ 1200.532339] ffff8803fe42dfd8 ffff8803fe42dfd8 ffff880429542e80 ffff88040d9745c0 [ 1200.532344] ffff880415321d00 ffff8804289241e8 ffff8804289241e8 0000000000000000 [ 1200.532350] Call Trace: [ 1200.532356] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1200.532376] [<ffffffffa00bf23d>] wait_current_trans.isra.28+0x9d/0x100 [btrfs] [ 1200.532380] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1200.532399] [<ffffffffa00c09a8>] start_transaction+0x158/0x460 [btrfs] [ 1200.532406] [<ffffffff811a3040>] ? kern_path_create+0x90/0x170 [ 1200.532424] [<ffffffffa00c0fe8>] btrfs_start_transaction+0x18/0x20 [btrfs] [ 1200.532444] [<ffffffffa00cd91e>] btrfs_mkdir+0x4e/0x1d0 [btrfs] [ 1200.532452] [<ffffffff812cefec>] ? security_inode_permission+0x1c/0x30 [ 1200.532457] [<ffffffff8119f3e6>] vfs_mkdir+0xa6/0x130 [ 1200.532462] [<ffffffff811a44ba>] sys_mkdirat+0xaa/0xf0 [ 1200.532467] [<ffffffff816d59dd>] system_call_fastpath+0x1a/0x1f [ 1200.532471] INFO: task aptitude:3586 blocked for more than 120 seconds. [ 1200.532474] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1200.532476] aptitude D ffff88043fc53ec0 0 3586 3585 0x00000000 [ 1200.532480] ffff8803f7d71b80 0000000000000082 ffff88041ba32e80 ffff8803f7d71fd8 [ 1200.532485] ffff8803f7d71fd8 ffff8803f7d71fd8 ffff880429542e80 ffff88041ba32e80 [ 1200.532491] ffff880415321d00 ffff8804289241e8 ffff8804289241e8 0000000000000000 [ 1200.532496] Call Trace: [ 1200.532502] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1200.532521] [<ffffffffa00bf23d>] wait_current_trans.isra.28+0x9d/0x100 [btrfs] [ 1200.532525] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1200.532542] [<ffffffffa00c09a8>] start_transaction+0x158/0x460 [btrfs] [ 1200.532548] [<ffffffff81065639>] ? ns_capable+0x29/0x50 [ 1200.532565] [<ffffffffa00c0fe8>] btrfs_start_transaction+0x18/0x20 [btrfs] [ 1200.532584] [<ffffffffa00cdc96>] btrfs_create+0x46/0x220 [btrfs] [ 1200.532590] [<ffffffff812cefec>] ? security_inode_permission+0x1c/0x30 [ 1200.532595] [<ffffffff8119f032>] ? __inode_permission+0x62/0xe0 [ 1200.532599] [<ffffffff811a0975>] vfs_create+0xb5/0x120 [ 1200.532604] [<ffffffff811a2254>] do_last+0xd74/0xea0 [ 1200.532609] [<ffffffff811a3293>] path_openat+0xb3/0x4b0 [ 1200.532616] [<ffffffff81159239>] ? handle_mm_fault+0x299/0x670 [ 1200.532623] [<ffffffff8117d00f>] ? kmem_cache_free+0x2f/0x130 [ 1200.532628] [<ffffffff811a4091>] do_filp_open+0x41/0xa0 [ 1200.532634] [<ffffffff811b1819>] ? __alloc_fd+0xd9/0x130 [ 1200.532640] [<ffffffff81193e73>] do_sys_open+0xf3/0x230 [ 1200.532644] [<ffffffff81193fd1>] sys_open+0x21/0x30 [ 1200.532648] [<ffffffff816d59dd>] system_call_fastpath+0x1a/0x1f [ 1320.532214] INFO: task btrfs-transacti:1076 blocked for more than 120 seconds. [ 1320.532220] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1320.532223] btrfs-transacti D ffff88043fc13ec0 0 1076 2 0x00000000 [ 1320.532230] ffff88041bb73d38 0000000000000046 ffff88042576ae80 ffff88041bb73fd8 [ 1320.532236] ffff88041bb73fd8 ffff88041bb73fd8 ffffffff81c15440 ffff88042576ae80 [ 1320.532242] ffff8804289a4800 ffff880409819130 ffff880415321d00 0000000000000000 [ 1320.532248] Call Trace: [ 1320.532261] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1320.532268] [<ffffffff816ca68c>] schedule_timeout+0x1ec/0x2b0 [ 1320.532307] [<ffffffffa00d6929>] ? btrfs_run_ordered_operations+0x2b9/0x2f0 [btrfs] [ 1320.532315] [<ffffffff81044b49>] ? default_spin_lock_flags+0x9/0x10 [ 1320.532337] [<ffffffffa00bfc8a>] btrfs_commit_transaction+0x38a/0xac0 [btrfs] [ 1320.532343] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1320.532363] [<ffffffffa00b8ecd>] transaction_kthread+0x1bd/0x240 [btrfs] [ 1320.532381] [<ffffffffa00b8d10>] ? write_dev_flush.part.107+0xc0/0xc0 [btrfs] [ 1320.532385] [<ffffffff8107d580>] kthread+0xc0/0xd0 [ 1320.532390] [<ffffffff8107d4c0>] ? kthread_create_on_node+0x120/0x120 [ 1320.532395] [<ffffffff816d592c>] ret_from_fork+0x7c/0xb0 [ 1320.532400] [<ffffffff8107d4c0>] ? kthread_create_on_node+0x120/0x120 [ 1320.532425] INFO: task tar:3368 blocked for more than 120 seconds. [ 1320.532427] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1320.532429] tar D ffff88043fc53ec0 0 3368 3269 0x00000000 [ 1320.532433] ffff8803fe42ddc8 0000000000000082 ffff88040d9745c0 ffff8803fe42dfd8 [ 1320.532439] ffff8803fe42dfd8 ffff8803fe42dfd8 ffff880429542e80 ffff88040d9745c0 [ 1320.532444] ffff880415321d00 ffff8804289241e8 ffff8804289241e8 0000000000000000 [ 1320.532450] Call Trace: [ 1320.532456] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1320.532476] [<ffffffffa00bf23d>] wait_current_trans.isra.28+0x9d/0x100 [btrfs] [ 1320.532480] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1320.532499] [<ffffffffa00c09a8>] start_transaction+0x158/0x460 [btrfs] [ 1320.532505] [<ffffffff811a3040>] ? kern_path_create+0x90/0x170 [ 1320.532523] [<ffffffffa00c0fe8>] btrfs_start_transaction+0x18/0x20 [btrfs] [ 1320.532543] [<ffffffffa00cd91e>] btrfs_mkdir+0x4e/0x1d0 [btrfs] [ 1320.532551] [<ffffffff812cefec>] ? security_inode_permission+0x1c/0x30 [ 1320.532555] [<ffffffff8119f3e6>] vfs_mkdir+0xa6/0x130 [ 1320.532560] [<ffffffff811a44ba>] sys_mkdirat+0xaa/0xf0 [ 1320.532565] [<ffffffff816d59dd>] system_call_fastpath+0x1a/0x1f [ 1320.532570] INFO: task aptitude:3586 blocked for more than 120 seconds. [ 1320.532572] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1320.532574] aptitude D ffff88043fc53ec0 0 3586 3585 0x00000000 [ 1320.532578] ffff8803f7d71b80 0000000000000082 ffff88041ba32e80 ffff8803f7d71fd8 [ 1320.532583] ffff8803f7d71fd8 ffff8803f7d71fd8 ffff880429542e80 ffff88041ba32e80 [ 1320.532589] ffff880415321d00 ffff8804289241e8 ffff8804289241e8 0000000000000000 [ 1320.532594] Call Trace: [ 1320.532601] [<ffffffff816cc219>] schedule+0x29/0x70 [ 1320.532619] [<ffffffffa00bf23d>] wait_current_trans.isra.28+0x9d/0x100 [btrfs] [ 1320.532623] [<ffffffff8107de90>] ? finish_wait+0x80/0x80 [ 1320.532640] [<ffffffffa00c09a8>] start_transaction+0x158/0x460 [btrfs] [ 1320.532646] [<ffffffff81065639>] ? ns_capable+0x29/0x50 [ 1320.532663] [<ffffffffa00c0fe8>] btrfs_start_transaction+0x18/0x20 [btrfs] [ 1320.532682] [<ffffffffa00cdc96>] btrfs_create+0x46/0x220 [btrfs] [ 1320.532689] [<ffffffff812cefec>] ? security_inode_permission+0x1c/0x30 [ 1320.532693] [<ffffffff8119f032>] ? __inode_permission+0x62/0xe0 [ 1320.532698] [<ffffffff811a0975>] vfs_create+0xb5/0x120 [ 1320.532703] [<ffffffff811a2254>] do_last+0xd74/0xea0 [ 1320.532708] [<ffffffff811a3293>] path_openat+0xb3/0x4b0 [ 1320.532715] [<ffffffff81159239>] ? handle_mm_fault+0x299/0x670 [ 1320.532722] [<ffffffff8117d00f>] ? kmem_cache_free+0x2f/0x130 [ 1320.532727] [<ffffffff811a4091>] do_filp_open+0x41/0xa0 [ 1320.532732] [<ffffffff811b1819>] ? __alloc_fd+0xd9/0x130 [ 1320.532737] [<ffffffff81193e73>] do_sys_open+0xf3/0x230 [ 1320.532742] [<ffffffff81193fd1>] sys_open+0x21/0x30 [ 1320.532746] [<ffffffff816d59dd>] system_call_fastpath+0x1a/0x1f ---- -- () ASCII Ribbon Campaign /\ Keep it simple! -- 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