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* WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
@ 2013-04-30  6:37 Alexander Skwar
  2013-04-30  6:55 ` Helmut Hullen
  0 siblings, 1 reply; 14+ messages in thread
From: Alexander Skwar @ 2013-04-30  6:37 UTC (permalink / raw)
  To: linux-btrfs

Hello

On my HP Compaq dc5800 with Ubuntu 13.04 and their 3.8.0-19-lowlatency
kernel, I've got quite some kernel traces in the syslog. You can find
them below or at http://pastebin.com/bLXPBX67 (to avoid line breaks…).

These kernel traces all begin with:

WARNING: at fs/btrfs/free-space-cache.c:921
__btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()


Most of the time, it starts with:

Call Trace:
 [<ffffffff8105a8df>] warn_slowpath_common+0x7f/0xc0

But once, I also had:

Call Trace:
 [<ffffffff81138e59>] warn_alloc_failed+0xe9/0x140



It happens most of the time, when I copied something on a btrfs. But
it also happened right now, when the system was basically idle. The
fs is on a "normal" SATA disk (ie. no SSD or usb or such).


I created the btrfs on the linux 3.8.0-19-lowlatency kernel with:

a@ewzw032:~$ btrfs version
Btrfs v0.20-rc1

Line 921 of free-space-cache.c (-> http://pastebin.com/yNQMPG3P) is
the WARN_ON(1) in this block:


        /* Make sure we can fit our crcs into the first page */
        if (io_ctl.check_crcs &&
            (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) {
                WARN_ON(1);
                goto out_nospc;
        }


Well - what can be done about it?



Here are my kernel traces:

Apr 29 12:59:31 ewzw032 kernel: [ 6275.016478] ------------[ cut here
]------------
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016507] WARNING: at
fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0
[btrfs]()
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016509] Hardware name: HP
Compaq dc5800 Microtower
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016510] Modules linked in: arc4
md4 parport_pc ppdev bnep rfcomm bluetooth nls_utf8 cifs fscache ext2
snd_hda_codec_analog snd_hda_intel snd_hda_codec coretemp tpm_infineon
snd_hwdep snd_pcm snd_page_alloc dm_multipath snd_seq_midi
snd_seq_midi_event snd_rawmidi kvm_intel kvm snd_seq snd_seq_device
snd_timer scsi_dh snd psmouse soundcore gpio_ich hp_wmi sparse_keymap
serio_raw lpc_ich mei wmi microcode tpm_tis nvidia(POF) mac_hid lp
parport btrfs zlib_deflate libcrc32c hid_generic usbhid hid
usb_storage floppy e1000e
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016537] Pid: 4608, comm:
btrfs-transacti Tainted: PF       W  O 3.8.0-19-lowlatency #13-Ubuntu
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016538] Call Trace:
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016544]  [<ffffffff8105a8df>]
warn_slowpath_common+0x7f/0xc0
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016546]  [<ffffffff8105a93a>]
warn_slowpath_null+0x1a/0x20
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016556]  [<ffffffffa0107c29>]
__btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016559]  [<ffffffff81096c40>] ?
set_next_entity+0x80/0x90
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016570]  [<ffffffffa0107fa5>]
btrfs_write_out_cache+0x95/0xf0 [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016579]  [<ffffffffa00bcc07>]
btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016588]  [<ffffffffa012ed52>]
commit_cowonly_roots+0x15a/0x22c [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016598]  [<ffffffffa00cc4ec>]
btrfs_commit_transaction+0x62c/0xb00 [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016601]  [<ffffffff81080070>] ?
finish_wait+0x80/0x80
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016610]  [<ffffffffa00c54cd>]
transaction_kthread+0x1ad/0x230 [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016620]  [<ffffffffa00c5320>] ?
write_dev_flush.part.107+0xc0/0xc0 [btrfs]
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016622]  [<ffffffff8107f890>]
kthread+0xc0/0xd0
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016624]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016628]  [<ffffffff816dfdec>]
ret_from_fork+0x7c/0xb0
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016629]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 12:59:31 ewzw032 kernel: [ 6275.016631] ---[ end trace
3afa1c596d559b57 ]---





Apr 29 13:05:18 ewzw032 kernel: [ 6621.268618] ------------[ cut here
]------------
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268648] WARNING: at
fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0
[btrfs]()
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268650] Hardware name: HP
Compaq dc5800 Microtower
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268651] Modules linked in: arc4
md4 parport_pc ppdev bnep rfcomm bluetooth nls_utf8 cifs fscache ext2
snd_hda_codec_analog snd_hda_intel snd_hda_codec coretemp tpm_infineon
snd_hwdep snd_pcm snd_page_alloc dm_multipath snd_seq_midi
snd_seq_midi_event snd_rawmidi kvm_intel kvm snd_seq snd_seq_device
snd_timer scsi_dh snd psmouse soundcore gpio_ich hp_wmi sparse_keymap
serio_raw lpc_ich mei wmi microcode tpm_tis nvidia(POF) mac_hid lp
parport btrfs zlib_deflate libcrc32c hid_generic usbhid hid
usb_storage floppy e1000e
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268678] Pid: 4608, comm:
btrfs-transacti Tainted: PF       W  O 3.8.0-19-lowlatency #13-Ubuntu
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268679] Call Trace:
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268685]  [<ffffffff8105a8df>]
warn_slowpath_common+0x7f/0xc0
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268687]  [<ffffffff8105a93a>]
warn_slowpath_null+0x1a/0x20
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268698]  [<ffffffffa0107c29>]
__btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268708]  [<ffffffffa00c713d>] ?
btrfs_buffer_uptodate+0x6d/0x80 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268711]  [<ffffffff81096c40>] ?
set_next_entity+0x80/0x90
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268721]  [<ffffffffa0107fa5>]
btrfs_write_out_cache+0x95/0xf0 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268731]  [<ffffffffa00bcc07>]
btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268739]  [<ffffffffa012ed52>]
commit_cowonly_roots+0x15a/0x22c [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268749]  [<ffffffffa00cc4ec>]
btrfs_commit_transaction+0x62c/0xb00 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268752]  [<ffffffff81080070>] ?
finish_wait+0x80/0x80
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268761]  [<ffffffffa00c54cd>]
transaction_kthread+0x1ad/0x230 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268771]  [<ffffffffa00c5320>] ?
write_dev_flush.part.107+0xc0/0xc0 [btrfs]
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268773]  [<ffffffff8107f890>]
kthread+0xc0/0xd0
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268775]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268778]  [<ffffffff816dfdec>]
ret_from_fork+0x7c/0xb0
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268780]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 13:05:18 ewzw032 kernel: [ 6621.268781] ---[ end trace
3afa1c596d559b62 ]---
Apr 29 13:05:55 ewzw032 kernel: [ 6658.063049] ------------[ cut here
]------------




Apr 29 17:29:59 ewzw032 kernel: [22502.923913] ------------[ cut here
]------------
Apr 29 17:29:59 ewzw032 kernel: [22502.923956] WARNING: at
fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0
[btrfs]()
Apr 29 17:29:59 ewzw032 kernel: [22502.923957] Hardware name: HP
Compaq dc5800 Microtower
Apr 29 17:29:59 ewzw032 kernel: [22502.923958] Modules linked in: arc4
md4 parport_pc ppdev bnep rfcomm bluetooth nls_utf8 cifs fscache ext2
snd_hda_codec_analog snd_hda_intel snd_hda_codec coretemp tpm_infineon
snd_hwdep snd_pcm snd_page_alloc dm_multipath snd_seq_midi
snd_seq_midi_event snd_rawmidi kvm_intel kvm snd_seq snd_seq_device
snd_timer scsi_dh snd psmouse soundcore gpio_ich hp_wmi sparse_keymap
serio_raw lpc_ich mei wmi microcode tpm_tis nvidia(POF) mac_hid lp
parport btrfs zlib_deflate libcrc32c hid_generic usbhid hid
usb_storage floppy e1000e
Apr 29 17:29:59 ewzw032 kernel: [22502.923987] Pid: 13579, comm:
btrfs-transacti Tainted: PF       W  O 3.8.0-19-lowlatency #13-Ubuntu
Apr 29 17:29:59 ewzw032 kernel: [22502.923988] Call Trace:
Apr 29 17:29:59 ewzw032 kernel: [22502.923999]  [<ffffffff8105a8df>]
warn_slowpath_common+0x7f/0xc0
Apr 29 17:29:59 ewzw032 kernel: [22502.924013]  [<ffffffff8105a93a>]
warn_slowpath_null+0x1a/0x20
Apr 29 17:29:59 ewzw032 kernel: [22502.924024]  [<ffffffffa0107c29>]
__btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924027]  [<ffffffff810979bc>] ?
update_curr+0xec/0x1a0
Apr 29 17:29:59 ewzw032 kernel: [22502.924029]  [<ffffffff8109d2ee>] ?
dequeue_pushable_task+0x2e/0x70
Apr 29 17:29:59 ewzw032 kernel: [22502.924040]  [<ffffffffa0107fa5>]
btrfs_write_out_cache+0x95/0xf0 [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924050]  [<ffffffffa00bcc07>]
btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924059]  [<ffffffffa012ed52>]
commit_cowonly_roots+0x15a/0x22c [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924069]  [<ffffffffa00cc4ec>]
btrfs_commit_transaction+0x62c/0xb00 [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924072]  [<ffffffff81080070>] ?
finish_wait+0x80/0x80
Apr 29 17:29:59 ewzw032 kernel: [22502.924082]  [<ffffffffa00c54cd>]
transaction_kthread+0x1ad/0x230 [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924091]  [<ffffffffa00c5320>] ?
write_dev_flush.part.107+0xc0/0xc0 [btrfs]
Apr 29 17:29:59 ewzw032 kernel: [22502.924093]  [<ffffffff8107f890>]
kthread+0xc0/0xd0
Apr 29 17:29:59 ewzw032 kernel: [22502.924095]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 17:29:59 ewzw032 kernel: [22502.924099]  [<ffffffff816dfdec>]
ret_from_fork+0x7c/0xb0
Apr 29 17:29:59 ewzw032 kernel: [22502.924101]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 17:29:59 ewzw032 kernel: [22502.924261] ---[ end trace
3afa1c596d559b6b ]---
Apr 29 17:30:45 ewzw032 kernel: [22548.083953] btrfs-transacti: page
allocation failure: order:5, mode:0x10c050
Apr 29 17:30:45 ewzw032 kernel: [22548.083958] Pid: 13579, comm:
btrfs-transacti Tainted: PF       W  O 3.8.0-19-lowlatency #13-Ubuntu
Apr 29 17:30:45 ewzw032 kernel: [22548.083960] Call Trace:
Apr 29 17:30:45 ewzw032 kernel: [22548.083968]  [<ffffffff81138e59>]
warn_alloc_failed+0xe9/0x140
Apr 29 17:30:45 ewzw032 kernel: [22548.083970]  [<ffffffff8113b6e6>] ?
drain_local_pages+0x16/0x20
Apr 29 17:30:45 ewzw032 kernel: [22548.083974]  [<ffffffff810bc82d>] ?
on_each_cpu_mask+0x8d/0xb0
Apr 29 17:30:45 ewzw032 kernel: [22548.083976]  [<ffffffff8113cd5c>]
__alloc_pages_nodemask+0x70c/0x950
Apr 29 17:30:45 ewzw032 kernel: [22548.083979]  [<ffffffff811787d8>]
alloc_pages_current+0xb8/0x180
Apr 29 17:30:45 ewzw032 kernel: [22548.083981]  [<ffffffff81137fce>]
__get_free_pages+0xe/0x50
Apr 29 17:30:45 ewzw032 kernel: [22548.083984]  [<ffffffff811807d9>]
kmalloc_order_trace+0x39/0xf0
Apr 29 17:30:45 ewzw032 kernel: [22548.083986]  [<ffffffff81182fc4>]
__kmalloc+0x184/0x190
Apr 29 17:30:45 ewzw032 kernel: [22548.084004]  [<ffffffffa0106fa1>]
io_ctl_init+0x91/0x140 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084032]  [<ffffffffa01075de>]
__btrfs_write_out_cache+0x6e/0x9a0 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084035]  [<ffffffff81096c40>] ?
set_next_entity+0x80/0x90
Apr 29 17:30:45 ewzw032 kernel: [22548.084045]  [<ffffffffa0107fa5>]
btrfs_write_out_cache+0x95/0xf0 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084055]  [<ffffffffa00bcc07>]
btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084064]  [<ffffffffa012ed52>]
commit_cowonly_roots+0x15a/0x22c [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084074]  [<ffffffffa00cc4ec>]
btrfs_commit_transaction+0x62c/0xb00 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084077]  [<ffffffff81080070>] ?
finish_wait+0x80/0x80
Apr 29 17:30:45 ewzw032 kernel: [22548.084086]  [<ffffffffa00c54cd>]
transaction_kthread+0x1ad/0x230 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084096]  [<ffffffffa00c5320>] ?
write_dev_flush.part.107+0xc0/0xc0 [btrfs]
Apr 29 17:30:45 ewzw032 kernel: [22548.084098]  [<ffffffff8107f890>]
kthread+0xc0/0xd0
Apr 29 17:30:45 ewzw032 kernel: [22548.084103]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 17:30:45 ewzw032 kernel: [22548.084106]  [<ffffffff816dfdec>]
ret_from_fork+0x7c/0xb0
Apr 29 17:30:45 ewzw032 kernel: [22548.084108]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 29 17:30:45 ewzw032 kernel: [22548.084301] Mem-Info:
Apr 29 17:30:45 ewzw032 kernel: [22548.084303] Node 0 DMA per-cpu:
Apr 29 17:30:45 ewzw032 kernel: [22548.084305] CPU    0: hi:    0,
btch:   1 usd:   0
Apr 29 17:30:45 ewzw032 kernel: [22548.084307] CPU    1: hi:    0,
btch:   1 usd:   0
Apr 29 17:30:45 ewzw032 kernel: [22548.084308] Node 0 DMA32 per-cpu:
Apr 29 17:30:45 ewzw032 kernel: [22548.084309] CPU    0: hi:  186,
btch:  31 usd:   0
Apr 29 17:30:45 ewzw032 kernel: [22548.084311] CPU    1: hi:  186,
btch:  31 usd:   0
Apr 29 17:30:45 ewzw032 kernel: [22548.084311] Node 0 Normal per-cpu:
Apr 29 17:30:45 ewzw032 kernel: [22548.084313] CPU    0: hi:  186,
btch:  31 usd:   0
Apr 29 17:30:45 ewzw032 kernel: [22548.084314] CPU    1: hi:  186,
btch:  31 usd: 166
Apr 29 17:30:45 ewzw032 kernel: [22548.084317] active_anon:733665
inactive_anon:281330 isolated_anon:0
Apr 29 17:30:45 ewzw032 kernel: [22548.084317]  active_file:238672
inactive_file:562643 isolated_file:0
Apr 29 17:30:45 ewzw032 kernel: [22548.084317]  unevictable:8
dirty:17770 writeback:48555 unstable:0
Apr 29 17:30:45 ewzw032 kernel: [22548.084317]  free:49760
slab_reclaimable:25129 slab_unreclaimable:14172
Apr 29 17:30:45 ewzw032 kernel: [22548.084317]  mapped:52305
shmem:6399 pagetables:18147 bounce:0
Apr 29 17:30:45 ewzw032 kernel: [22548.084317]  free_cma:0
Apr 29 17:30:45 ewzw032 kernel: [22548.084320] Node 0 DMA free:15900kB
min:128kB low:160kB high:192kB active_anon:0kB inactive_anon:0kB
active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB
isolated(file):0kB present:15652kB managed:15908kB mlocked:0kB
dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB
slab_unreclaimable:8kB kernel_stack:0kB pagetables:0kB unstable:0kB
bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0
all_unreclaimable? yes
Apr 29 17:30:45 ewzw032 kernel: [22548.084324] lowmem_reserve[]: 0
3496 7969 7969
Apr 29 17:30:45 ewzw032 kernel: [22548.084327] Node 0 DMA32
free:99044kB min:29592kB low:36988kB high:44388kB active_anon:478348kB
inactive_anon:501448kB active_file:499548kB inactive_file:1787932kB
unevictable:16kB isolated(anon):0kB isolated(file):0kB
present:3580096kB managed:3539248kB mlocked:16kB dirty:20784kB
writeback:5060kB mapped:68704kB shmem:6976kB slab_reclaimable:29648kB
slab_unreclaimable:9508kB kernel_stack:696kB pagetables:10948kB
unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0
all_unreclaimable? no
Apr 29 17:30:45 ewzw032 kernel: [22548.084332] lowmem_reserve[]: 0 0 4473 4473
Apr 29 17:30:45 ewzw032 kernel: [22548.084334] Node 0 Normal
free:84212kB min:37860kB low:47324kB high:56788kB
active_anon:2456312kB inactive_anon:623872kB active_file:455140kB
inactive_file:462640kB unevictable:16kB isolated(anon):0kB
isolated(file):0kB present:4580352kB managed:4520784kB mlocked:16kB
dirty:50296kB writeback:189160kB mapped:140516kB shmem:18620kB
slab_reclaimable:70868kB slab_unreclaimable:47172kB
kernel_stack:6384kB pagetables:61640kB unstable:0kB bounce:0kB
free_cma:0kB writeback_tmp:0kB pages_scanned:28 all_unreclaimable? no
Apr 29 17:30:45 ewzw032 kernel: [22548.084339] lowmem_reserve[]: 0 0 0 0
Apr 29 17:30:45 ewzw032 kernel: [22548.084341] Node 0 DMA: 1*4kB (U)
1*8kB (U) 1*16kB (U) 0*32kB 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB
1*1024kB (U) 1*2048kB (R) 3*4096kB (M) = 15900kB
Apr 29 17:30:45 ewzw032 kernel: [22548.084351] Node 0 DMA32: 7768*4kB
(UEM) 4055*8kB (UEM) 1990*16kB (UM) 2*32kB (R) 0*64kB 1*128kB (R)
0*256kB 1*512kB (R) 1*1024kB (R) 1*2048kB (R) 0*4096kB = 99128kB
Apr 29 17:30:45 ewzw032 kernel: [22548.084361] Node 0 Normal: 6110*4kB
(UEM) 6160*8kB (UEM) 402*16kB (UEM) 11*32kB (UE) 0*64kB 1*128kB (R)
1*256kB (R) 1*512kB (R) 1*1024kB (R) 1*2048kB (R) 0*4096kB = 84472kB
Apr 29 17:30:45 ewzw032 kernel: [22548.084371] 807776 total pagecache pages
Apr 29 17:30:45 ewzw032 kernel: [22548.084372] 102 pages in swap cache
Apr 29 17:30:45 ewzw032 kernel: [22548.084374] Swap cache stats: add
7253, delete 7151, find 482/495
Apr 29 17:30:45 ewzw032 kernel: [22548.084375] Free swap  = 10068048kB
Apr 29 17:30:45 ewzw032 kernel: [22548.084376] Total swap = 10096632kB
Apr 29 17:30:45 ewzw032 kernel: [22548.114584] 2080752 pages RAM
Apr 29 17:30:45 ewzw032 kernel: [22548.114586] 129680 pages reserved
Apr 29 17:30:45 ewzw032 kernel: [22548.114587] 1156729 pages shared
Apr 29 17:30:45 ewzw032 kernel: [22548.114588] 1386865 pages non-shared
Apr 29 17:31:39 ewzw032 kernel: [22602.788543] device fsid
10fd7c6c-59df-47db-8659-577dd8ff1fd8 devid 1 transid 953 /dev/dm-6
Apr 29 17:31:47 ewzw032 kernel: [22610.323304] btrfs: new size for
/dev/dm-6 is 64424509440






Apr 30 08:07:05 ewzw032 kernel: [75128.655594] ------------[ cut here
]------------
Apr 30 08:07:05 ewzw032 kernel: [75128.655623] WARNING: at
fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0
[btrfs]()
Apr 30 08:07:05 ewzw032 kernel: [75128.655625] Hardware name: HP
Compaq dc5800 Microtower
Apr 30 08:07:05 ewzw032 kernel: [75128.655626] Modules linked in: arc4
md4 parport_pc ppdev bnep rfcomm bluetooth nls_utf8 cifs fscache ext2
snd_hda_codec_analog snd_hda_intel snd_hda_codec coretemp tpm_infineon
snd_hwdep snd_pcm snd_page_alloc dm_multipath snd_seq_midi
snd_seq_midi_event snd_rawmidi kvm_intel kvm snd_seq snd_seq_device
snd_timer scsi_dh snd psmouse soundcore gpio_ich hp_wmi sparse_keymap
serio_raw lpc_ich mei wmi microcode tpm_tis nvidia(POF) mac_hid lp
parport btrfs zlib_deflate libcrc32c hid_generic usbhid hid
usb_storage floppy e1000e
Apr 30 08:07:05 ewzw032 kernel: [75128.655652] Pid: 13579, comm:
btrfs-transacti Tainted: PF       W  O 3.8.0-19-lowlatency #13-Ubuntu
Apr 30 08:07:05 ewzw032 kernel: [75128.655654] Call Trace:
Apr 30 08:07:05 ewzw032 kernel: [75128.655659]  [<ffffffff8105a8df>]
warn_slowpath_common+0x7f/0xc0
Apr 30 08:07:05 ewzw032 kernel: [75128.655662]  [<ffffffff8105a93a>]
warn_slowpath_null+0x1a/0x20
Apr 30 08:07:05 ewzw032 kernel: [75128.655672]  [<ffffffffa0107c29>]
__btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655675]  [<ffffffff81096c40>] ?
set_next_entity+0x80/0x90
Apr 30 08:07:05 ewzw032 kernel: [75128.655686]  [<ffffffffa0107fa5>]
btrfs_write_out_cache+0x95/0xf0 [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655695]  [<ffffffffa00bcc07>]
btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655704]  [<ffffffffa012ed52>]
commit_cowonly_roots+0x15a/0x22c [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655715]  [<ffffffffa00cc4ec>]
btrfs_commit_transaction+0x62c/0xb00 [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655717]  [<ffffffff81080070>] ?
finish_wait+0x80/0x80
Apr 30 08:07:05 ewzw032 kernel: [75128.655727]  [<ffffffffa00c54cd>]
transaction_kthread+0x1ad/0x230 [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655736]  [<ffffffffa00c5320>] ?
write_dev_flush.part.107+0xc0/0xc0 [btrfs]
Apr 30 08:07:05 ewzw032 kernel: [75128.655738]  [<ffffffff8107f890>]
kthread+0xc0/0xd0
Apr 30 08:07:05 ewzw032 kernel: [75128.655740]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 30 08:07:05 ewzw032 kernel: [75128.655743]  [<ffffffff816dfdec>]
ret_from_fork+0x7c/0xb0
Apr 30 08:07:05 ewzw032 kernel: [75128.655745]  [<ffffffff8107f7d0>] ?
kthread_create_on_node+0x120/0x120
Apr 30 08:07:05 ewzw032 kernel: [75128.655747] ---[ end trace
3afa1c596d559b6d ]---



Thanks a lot,

Alexander
--
=>        Google+ => http://plus.skwar.me         <==
=> Chat (Jabber/Google Talk) => a.skwar@gmail.com <==

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30  6:37 WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]() Alexander Skwar
@ 2013-04-30  6:55 ` Helmut Hullen
  2013-04-30  9:41   ` Hugo Mills
  0 siblings, 1 reply; 14+ messages in thread
From: Helmut Hullen @ 2013-04-30  6:55 UTC (permalink / raw)
  To: linux-btrfs

Hallo, Alexander,

Du meintest am 30.04.13:

> On my HP Compaq dc5800 with Ubuntu 13.04 and their
> 3.8.0-19-lowlatency kernel, I've got quite some kernel traces in the
> syslog.

It's a very good idea to use the newest kernel for btrfs. 3.8.0 is  
really old.

Just try kernel 3.8.10.

Viele Gruesse!
Helmut

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30  6:55 ` Helmut Hullen
@ 2013-04-30  9:41   ` Hugo Mills
  2013-04-30 11:51     ` Alexander Skwar
  0 siblings, 1 reply; 14+ messages in thread
From: Hugo Mills @ 2013-04-30  9:41 UTC (permalink / raw)
  To: helmut; +Cc: linux-btrfs

[-- Attachment #1: Type: text/plain, Size: 1142 bytes --]

On Tue, Apr 30, 2013 at 08:55:00AM +0200, Helmut Hullen wrote:
> Hallo, Alexander,
> 
> Du meintest am 30.04.13:
> 
> > On my HP Compaq dc5800 with Ubuntu 13.04 and their
> > 3.8.0-19-lowlatency kernel, I've got quite some kernel traces in the
> > syslog.
> 
> It's a very good idea to use the newest kernel for btrfs. 3.8.0 is  
> really old.
> 
> Just try kernel 3.8.10.

   The differences in btrfs between the two are very small, and even
I(*) wouldn't call 3.8.0 "very old" quite yet, given that 3.9 was only
released yesterday. From memory, there's one btrfs patch in the 3.8
stable series.

   Your problem is "just" a warning, and appears to be something to do
with running out of space, or having too many CRCs... I don't really
know the free space cache code at all well, so I'm mostly guessing
here, from looking at the WARN_ON in __btrfs_write_out_cache.

   Hugo.

(*) High Priest of the Kernel Upgrade.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
                       ---   __(_'>  Squeak!   ---                       

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 828 bytes --]

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30  9:41   ` Hugo Mills
@ 2013-04-30 11:51     ` Alexander Skwar
  2013-04-30 13:58       ` Josef Bacik
  0 siblings, 1 reply; 14+ messages in thread
From: Alexander Skwar @ 2013-04-30 11:51 UTC (permalink / raw)
  To: linux-btrfs

Hugo Mills <hugo <at> carfax.org.uk> writes:

>    The differences in btrfs between the two are very small, and even
> I(*) wouldn't call 3.8.0 "very old" quite yet, given that 3.9 was only
> released yesterday. From memory, there's one btrfs patch in the 3.8
> stable series.
> 
>    Your problem is "just" a warning, and appears to be something to do
> with running out of space, or having too many CRCs... I don't really
> know the free space cache code at all well, so I'm mostly guessing
> here, from looking at the WARN_ON in __btrfs_write_out_cache.

Yes, I'm aware that this just a warning, but I'm a bit scared
because of the big number of those warnings.

FWIW, I also got that exact same kernel trace on the Ubuntu
kernel 3.5.0-28-lowlatency; see http://pastebin.com/rmPAqcTu or here:

------------[ cut here ]------------
WARNING: at fs/btrfs/free-space-cache.c:922 
__btrfs_write_out_cache+0x6b9/0x990 [btrfs]()
Hardware name: HP Compaq dc5800 Microtower
Modules linked in: btrfs zlib_deflate libcrc32c des_generic md4 nvidia(PO) 
snd_hda_codec_analog arc4 tpm_infineon coretemp snd_hda_intel rtl8192cu 
snd_hda_codec kvm_intel rtl8192c_common rtlwifi kvm snd_hwdep snd_pcm 
parport_pc snd_seq_midi bnep rfcomm mac80211 ppdev snd_rawmidi bluetooth 
snd_seq_midi_event snd_seq binfmt_misc snd_timer snd_seq_device cfg80211 
dm_multipath psmouse hp_wmi snd scsi_dh gpio_ich sparse_keymap soundcore 
microcode serio_raw tpm_tis mei mac_hid snd_page_alloc wmi lpc_ich lp 
parport nls_utf8 cifs fscache ext2 hid_generic usbhid hid usb_storage floppy 
e1000e
Pid: 25834, comm: btrfs Tainted: P           O 3.5.0-28-lowlatency #31-
Ubuntu
Call Trace:
 [<ffffffff81053d5f>] warn_slowpath_common+0x7f/0xc0
 [<ffffffff81053dba>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa0f83fd9>] __btrfs_write_out_cache+0x6b9/0x990 [btrfs]
 [<ffffffffa0f29325>] ? __find_space_info+0x85/0xa0 [btrfs]
 [<ffffffff8168f76e>] ? _raw_spin_unlock+0xe/0x40
 [<ffffffffa0f32fbc>] ? btrfs_run_delayed_refs+0x1ec/0x470 [btrfs]
 [<ffffffffa0f84345>] btrfs_write_out_cache+0x95/0xf0 [btrfs]
 [<ffffffffa0f3375f>] btrfs_write_dirty_block_groups+0x51f/0x5f0 [btrfs]
 [<ffffffffa0f9edc2>] commit_cowonly_roots+0xfd/0x1c7 [btrfs]
 [<ffffffffa0f94121>] ? btrfs_run_delayed_items+0xd1/0x150 [btrfs]
 [<ffffffffa0f44725>] btrfs_commit_transaction+0x5d5/0xb00 [btrfs]
 [<ffffffff81078ff0>] ? finish_wait+0x80/0x80
 [<ffffffff8119f122>] ? __d_instantiate+0xd2/0x110
 [<ffffffff812bf11b>] ? security_d_instantiate+0x1b/0x30
 [<ffffffffa0f9f8ab>] create_subvol+0x4d1/0x4f8 [btrfs]
 [<ffffffffa0f794e5>] btrfs_mksubvol+0x3a5/0x400 [btrfs]
 [<ffffffffa0f795fe>] btrfs_ioctl_snap_create_transid+0xbe/0x180 [btrfs]
 [<ffffffffa0f79716>] btrfs_ioctl_snap_create+0x56/0x80 [btrfs]
 [<ffffffffa0f7baba>] btrfs_ioctl+0xc0a/0x1280 [btrfs]
 [<ffffffff81692b84>] ? do_page_fault+0x1b4/0x4b0
 [<ffffffff8119b307>] do_vfs_ioctl+0x97/0x530
 [<ffffffff811898c5>] ? vfs_write+0x105/0x180
 [<ffffffff8119b839>] sys_ioctl+0x99/0xa0
 [<ffffffff8169081e>] ? do_device_not_available+0xe/0x10
 [<ffffffff816969e9>] system_call_fastpath+0x16/0x1b
---[ end trace fadd80d2b7f6ec9f ]---



Both traces (from 3.8.0 and 3.5.0) are in fs/btrfs/free-space-cache.c
and have warn_slowpath_common as the first function. Strange, isn't
it?

Since the problem exists for a long time, I pretty much doubt that
just updating the kernel source would help. I'd rather not, I'd 
rather stay with the kernel of my distribution.

I should have mentioned in my OP, that the btrfs is on a LVM. Right
now, I've got two distinct btrfs filesystems on the system; both
on LVM and on seperate logical volumes.

I get this kernel trace / warning only on one of these filesystems.
The LV existed also "back in kernel 3.5.0 times". I've since ran
a btrfs scrub, but it didn't find any errors:


a@ewzw032:~$ sudo btrfs scrub status -d /data
scrub status for 8009e99c-726d-46fb-b68c-be57fb66ca05
scrub device /dev/mapper/system-Data (id 1) history
	scrub started at Tue Apr 30 08:55:27 2013 and finished after 2989 
seconds
	total bytes scrubbed: 146.82GB with 0 errors
a@ewzw032:~$ sudo btrfs scrub status -R /data
scrub status for 8009e99c-726d-46fb-b68c-be57fb66ca05
	scrub started at Tue Apr 30 08:55:27 2013 and finished after 2989 
seconds
	data_extents_scrubbed: 2564422
	tree_extents_scrubbed: 107996
	data_bytes_scrubbed: 157200080896
	tree_bytes_scrubbed: 442351616
	read_errors: 0
	csum_errors: 0
	verify_errors: 0
	no_csum: 0
	csum_discards: 0
	super_errors: 0
	malloc_errors: 0
	uncorrectable_errors: 0
	unverified_errors: 0
	corrected_errors: 0
	last_physical: 251959246848

Best regards,
Alexander


^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30 11:51     ` Alexander Skwar
@ 2013-04-30 13:58       ` Josef Bacik
  2013-04-30 14:33         ` Alexander Skwar
  0 siblings, 1 reply; 14+ messages in thread
From: Josef Bacik @ 2013-04-30 13:58 UTC (permalink / raw)
  To: Alexander Skwar; +Cc: linux-btrfs

On Tue, Apr 30, 2013 at 05:51:17AM -0600, Alexander Skwar wrote:
> Hugo Mills <hugo <at> carfax.org.uk> writes:
> 
> >    The differences in btrfs between the two are very small, and even
> > I(*) wouldn't call 3.8.0 "very old" quite yet, given that 3.9 was only
> > released yesterday. From memory, there's one btrfs patch in the 3.8
> > stable series.
> > 
> >    Your problem is "just" a warning, and appears to be something to do
> > with running out of space, or having too many CRCs... I don't really
> > know the free space cache code at all well, so I'm mostly guessing
> > here, from looking at the WARN_ON in __btrfs_write_out_cache.
> 
> Yes, I'm aware that this just a warning, but I'm a bit scared
> because of the big number of those warnings.
> 
> FWIW, I also got that exact same kernel trace on the Ubuntu
> kernel 3.5.0-28-lowlatency; see http://pastebin.com/rmPAqcTu or here:
> 
> ------------[ cut here ]------------
> WARNING: at fs/btrfs/free-space-cache.c:922 
> __btrfs_write_out_cache+0x6b9/0x990 [btrfs]()
> Hardware name: HP Compaq dc5800 Microtower
> Modules linked in: btrfs zlib_deflate libcrc32c des_generic md4 nvidia(PO) 
> snd_hda_codec_analog arc4 tpm_infineon coretemp snd_hda_intel rtl8192cu 
> snd_hda_codec kvm_intel rtl8192c_common rtlwifi kvm snd_hwdep snd_pcm 
> parport_pc snd_seq_midi bnep rfcomm mac80211 ppdev snd_rawmidi bluetooth 
> snd_seq_midi_event snd_seq binfmt_misc snd_timer snd_seq_device cfg80211 
> dm_multipath psmouse hp_wmi snd scsi_dh gpio_ich sparse_keymap soundcore 
> microcode serio_raw tpm_tis mei mac_hid snd_page_alloc wmi lpc_ich lp 
> parport nls_utf8 cifs fscache ext2 hid_generic usbhid hid usb_storage floppy 
> e1000e
> Pid: 25834, comm: btrfs Tainted: P           O 3.5.0-28-lowlatency #31-
> Ubuntu
> Call Trace:
>  [<ffffffff81053d5f>] warn_slowpath_common+0x7f/0xc0
>  [<ffffffff81053dba>] warn_slowpath_null+0x1a/0x20
>  [<ffffffffa0f83fd9>] __btrfs_write_out_cache+0x6b9/0x990 [btrfs]
>  [<ffffffffa0f29325>] ? __find_space_info+0x85/0xa0 [btrfs]
>  [<ffffffff8168f76e>] ? _raw_spin_unlock+0xe/0x40
>  [<ffffffffa0f32fbc>] ? btrfs_run_delayed_refs+0x1ec/0x470 [btrfs]
>  [<ffffffffa0f84345>] btrfs_write_out_cache+0x95/0xf0 [btrfs]
>  [<ffffffffa0f3375f>] btrfs_write_dirty_block_groups+0x51f/0x5f0 [btrfs]
>  [<ffffffffa0f9edc2>] commit_cowonly_roots+0xfd/0x1c7 [btrfs]
>  [<ffffffffa0f94121>] ? btrfs_run_delayed_items+0xd1/0x150 [btrfs]
>  [<ffffffffa0f44725>] btrfs_commit_transaction+0x5d5/0xb00 [btrfs]
>  [<ffffffff81078ff0>] ? finish_wait+0x80/0x80
>  [<ffffffff8119f122>] ? __d_instantiate+0xd2/0x110
>  [<ffffffff812bf11b>] ? security_d_instantiate+0x1b/0x30
>  [<ffffffffa0f9f8ab>] create_subvol+0x4d1/0x4f8 [btrfs]
>  [<ffffffffa0f794e5>] btrfs_mksubvol+0x3a5/0x400 [btrfs]
>  [<ffffffffa0f795fe>] btrfs_ioctl_snap_create_transid+0xbe/0x180 [btrfs]
>  [<ffffffffa0f79716>] btrfs_ioctl_snap_create+0x56/0x80 [btrfs]
>  [<ffffffffa0f7baba>] btrfs_ioctl+0xc0a/0x1280 [btrfs]
>  [<ffffffff81692b84>] ? do_page_fault+0x1b4/0x4b0
>  [<ffffffff8119b307>] do_vfs_ioctl+0x97/0x530
>  [<ffffffff811898c5>] ? vfs_write+0x105/0x180
>  [<ffffffff8119b839>] sys_ioctl+0x99/0xa0
>  [<ffffffff8169081e>] ? do_device_not_available+0xe/0x10
>  [<ffffffff816969e9>] system_call_fastpath+0x16/0x1b
> ---[ end trace fadd80d2b7f6ec9f ]---
> 

So we deal with this case fine, but it really shouldn't be happening, it only
happens if your block groups are way too large, which again shouldn't be
happening.  Can you run fsck on this device and see if it complains?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30 13:58       ` Josef Bacik
@ 2013-04-30 14:33         ` Alexander Skwar
  2013-04-30 17:53           ` Josef Bacik
  0 siblings, 1 reply; 14+ messages in thread
From: Alexander Skwar @ 2013-04-30 14:33 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs

Hello Josef

On Tue, Apr 30, 2013 at 3:58 PM, Josef Bacik <jbacik@fusionio.com> wrote:

> So we deal with this case fine, but it really shouldn't be happening, it only
> happens if your block groups are way too large, which again shouldn't be
> happening.  Can you run fsck on this device and see if it complains?  Thanks,


a@ewzw032:~$ sudo btrfsck /dev/system/Data
checking extents
checking fs roots
checking root refs
found 115308904448 bytes used err is 0
total csum bytes: 112056692
total tree bytes: 521891840
total fs tree bytes: 353947648
btree space waste bytes: 122297974
file data blocks allocated: 114787012608
 referenced 114787000320
Btrfs v0.20-rc1


No errors.

Alexander
-- 
=>        Google+ => http://plus.skwar.me         <==
=> Chat (Jabber/Google Talk) => a.skwar@gmail.com <==

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30 14:33         ` Alexander Skwar
@ 2013-04-30 17:53           ` Josef Bacik
  2013-05-01  6:39             ` Alexander Skwar
  0 siblings, 1 reply; 14+ messages in thread
From: Josef Bacik @ 2013-04-30 17:53 UTC (permalink / raw)
  To: Alexander Skwar; +Cc: Josef Bacik, linux-btrfs

On Tue, Apr 30, 2013 at 08:33:38AM -0600, Alexander Skwar wrote:
> Hello Josef
> 
> On Tue, Apr 30, 2013 at 3:58 PM, Josef Bacik <jbacik@fusionio.com> wrote:
> 
> > So we deal with this case fine, but it really shouldn't be happening, it only
> > happens if your block groups are way too large, which again shouldn't be
> > happening.  Can you run fsck on this device and see if it complains?  Thanks,
> 
> 
> a@ewzw032:~$ sudo btrfsck /dev/system/Data
> checking extents
> checking fs roots
> checking root refs
> found 115308904448 bytes used err is 0
> total csum bytes: 112056692
> total tree bytes: 521891840
> total fs tree bytes: 353947648
> btree space waste bytes: 122297974
> file data blocks allocated: 114787012608
>  referenced 114787000320
> Btrfs v0.20-rc1
> 

Can you run this patch and capture the output when you get the warning?  You
should see some mesages before the -- [ cut here ] -- part, make sure to capture
those.  Thanks,

Josef

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index ecca6c7..2e8e098 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -921,6 +921,10 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
 	/* Make sure we can fit our crcs into the first page */
 	if (io_ctl.check_crcs &&
 	    (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) {
+		printk(KERN_ERR "num_pages is %d, blockgroup? %s\n",
+		       io_ctl.num_pages, block_group ? "yes" : "no");
+		if (block_group)
+			printk(KERN_ERR "block group offset=%Lu, size=%Lu\n", block_group->key.objectid, block_group->key.offset);
 		WARN_ON(1);
 		goto out_nospc;
 	}

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-04-30 17:53           ` Josef Bacik
@ 2013-05-01  6:39             ` Alexander Skwar
  2013-05-01 18:57               ` Josef Bacik
  0 siblings, 1 reply; 14+ messages in thread
From: Alexander Skwar @ 2013-05-01  6:39 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs

Hello Josef

On Tue, Apr 30, 2013 at 7:53 PM, Josef Bacik <jbacik@fusionio.com> wrote:

> Can you run this patch and capture the output when you get the warning?  You
> should see some mesages before the -- [ cut here ] -- part, make sure to capture
> those.  Thanks,

Sure.

There you go (also on http://pastebin.com/7MHmgpPU):

 num_pages is 10000, blockgroup? yes
 block group offset=83999326208, size=167959920640
 ------------[ cut here ]------------
 WARNING: at fs/btrfs/free-space-cache.c:925
__btrfs_write_out_cache+0x9e2/0xa10 [btrfs]()
 Hardware name: HP Compaq dc5800 Microtower
 Modules linked in: arc4 md4 parport_pc ppdev rfcomm bnep bluetooth
nls_utf8 cifs fscache ext2 tpm_infineon snd_hda_codec_analog coretemp
kvm_intel kvm hp_wmi sparse_keymap gpio_ich snd_hda_intel
snd_hda_codec snd_hwdep snd_pcm snd_page_alloc dm_multipath
snd_seq_midi scsi_dh tpm_tis wmi snd_seq_midi_event snd_rawmidi
snd_seq snd_seq_device snd_timer nvidia(POF) mac_hid snd psmouse
microcode serio_raw lpc_ich mei soundcore lp parport btrfs
zlib_deflate libcrc32c hid_generic usbhid hid floppy e1000e
usb_storage
 Pid: 2803, comm: sync Tainted: PF          O 3.8.0-19-lowlatency #13
 Call Trace:
  [<ffffffff8105a8df>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8105a93a>] warn_slowpath_null+0x1a/0x20
  [<ffffffffa0103f52>] __btrfs_write_out_cache+0x9e2/0xa10 [btrfs]
  [<ffffffff81094065>] ? cpuacct_charge+0x75/0x80
  [<ffffffff810145d1>] ? __switch_to+0x181/0x4d0
  [<ffffffffa0104015>] btrfs_write_out_cache+0x95/0xf0 [btrfs]
  [<ffffffffa00b8c07>] btrfs_write_dirty_block_groups+0x527/0x620 [btrfs]
  [<ffffffffa012adc2>] commit_cowonly_roots+0x15a/0x22c [btrfs]
  [<ffffffffa00c84ec>] btrfs_commit_transaction+0x62c/0xb00 [btrfs]
  [<ffffffff81080070>] ? finish_wait+0x80/0x80
  [<ffffffff811ca3a0>] ? fdatawait_one_bdev+0x20/0x20
  [<ffffffffa009a9f2>] btrfs_sync_fs+0x62/0x110 [btrfs]
  [<ffffffff811ca3c0>] sync_fs_one_sb+0x20/0x30
  [<ffffffff8119db59>] iterate_supers+0xe9/0xf0
  [<ffffffff811ca555>] sys_sync+0x55/0x90
  [<ffffffff816dfe9d>] system_call_fastpath+0x1a/0x1f
 ---[ end trace 88dd9bc54a43ce1a ]---

I don't think it has to do with how much data I write at that time.
I also get this error, when I copy a 6kb file and then invoke "sync"
to force a write.

But… Hm… No, I think it IS size related. As I said, I get this error
even with a file which is 6520 bytes "big". BUT I do NOT get this
error when I copy a file which is just 1129 bytes "small".

Some more tests - I start to get these errors with
filesizes > 3916 bytes. Filesizes <= 3916 bytes -> no error.

Does that make sense to you?

Alexander
--
=>        Google+ => http://plus.skwar.me         <==
=> Chat (Jabber/Google Talk) => a.skwar@gmail.com <==

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-05-01  6:39             ` Alexander Skwar
@ 2013-05-01 18:57               ` Josef Bacik
  2013-05-01 19:19                 ` Jon Nelson
  2013-05-01 20:08                 ` Alexander Skwar
  0 siblings, 2 replies; 14+ messages in thread
From: Josef Bacik @ 2013-05-01 18:57 UTC (permalink / raw)
  To: Alexander Skwar; +Cc: Josef Bacik, linux-btrfs

On Wed, May 01, 2013 at 12:39:47AM -0600, Alexander Skwar wrote:
> Hello Josef
> 
> On Tue, Apr 30, 2013 at 7:53 PM, Josef Bacik <jbacik@fusionio.com> wrote:
> 
> > Can you run this patch and capture the output when you get the warning?  You
> > should see some mesages before the -- [ cut here ] -- part, make sure to capture
> > those.  Thanks,
> 
> Sure.
> 
> There you go (also on http://pastebin.com/7MHmgpPU):
> 
>  num_pages is 10000, blockgroup? yes
>  block group offset=83999326208, size=167959920640

Ok well that's not good, I'm not sure how you got a 156 gigabyte block group,
but thats why that warning is going off.  Can you pull btrfs-image down from
here

git://github.com/josefbacik/btrfs-progs.git

and build that and then run

./btrfs-image -c 9 -t 4 /dev/whatever somefile.img

and upload the image somewhere so I can take a look at it.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-05-01 18:57               ` Josef Bacik
@ 2013-05-01 19:19                 ` Jon Nelson
  2013-05-01 20:08                 ` Alexander Skwar
  1 sibling, 0 replies; 14+ messages in thread
From: Jon Nelson @ 2013-05-01 19:19 UTC (permalink / raw)
  To: linux-btrfs

Josef Bacik <jbacik <at> fusionio.com> writes:

..
> Ok well that's not good, I'm not sure how you got a 156 gigabyte block 
group,
> but thats why that warning is going off.  Can you pull btrfs-image down 
from
> here
> 
> git://github.com/josefbacik/btrfs-progs.git

What is the difference between this git repo and the one at 
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git

I notice that the former has commits the latter doesn't. Is the latter the 
analogue to btrfs-next ? 




^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-05-01 18:57               ` Josef Bacik
  2013-05-01 19:19                 ` Jon Nelson
@ 2013-05-01 20:08                 ` Alexander Skwar
       [not found]                   ` <CADn-QaPh9EZjnbr9HoRKTMi8OUgnvfRdD7riEDZ0hpkcNRN93Q@mail.gmail.com>
  1 sibling, 1 reply; 14+ messages in thread
From: Alexander Skwar @ 2013-05-01 20:08 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs

Hello Josef

On Wed, May 1, 2013 at 8:57 PM, Josef Bacik <jbacik@fusionio.com> wrote:

> and build that and then run
>
> ./btrfs-image -c 9 -t 4 /dev/whatever somefile.img
>
> and upload the image somewhere so I can take a look at it.  Thanks,

Sure thing ;)

You can download it from my Copy share:

https://copy.com/6UUFqWdalibY

I gpg encrypted it symmetrically; I'll send you the password in private
mail.

Alexander
--
=>        Google+ => http://plus.skwar.me         <==
=> Chat (Jabber/Google Talk) => a.skwar@gmail.com <==

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
       [not found]                   ` <CADn-QaPh9EZjnbr9HoRKTMi8OUgnvfRdD7riEDZ0hpkcNRN93Q@mail.gmail.com>
@ 2013-05-08 20:40                     ` Josef Bacik
  2013-05-08 20:47                     ` Josef Bacik
  1 sibling, 0 replies; 14+ messages in thread
From: Josef Bacik @ 2013-05-08 20:40 UTC (permalink / raw)
  To: Alexander Skwar; +Cc: Josef Bacik, linux-btrfs

On Wed, May 08, 2013 at 11:34:40AM -0600, Alexander Skwar wrote:
> Hello Josef
> 
> Did you have a chance to look at that image? Did you find anything?
> 
> Or should I simply create a new filesystem and forget about the issue?
> 

I haven't looked at it yet, let me run it right now and see if it's something I
can fix quickly.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
       [not found]                   ` <CADn-QaPh9EZjnbr9HoRKTMi8OUgnvfRdD7riEDZ0hpkcNRN93Q@mail.gmail.com>
  2013-05-08 20:40                     ` Josef Bacik
@ 2013-05-08 20:47                     ` Josef Bacik
  2013-05-13  8:33                       ` Alexander Skwar
  1 sibling, 1 reply; 14+ messages in thread
From: Josef Bacik @ 2013-05-08 20:47 UTC (permalink / raw)
  To: Alexander Skwar; +Cc: Josef Bacik, linux-btrfs

On Wed, May 08, 2013 at 11:34:40AM -0600, Alexander Skwar wrote:
> Hello Josef
> 
> Did you have a chance to look at that image? Did you find anything?
> 
> Or should I simply create a new filesystem and forget about the issue?
> 

So the file system isn't corrupt, you just got a giant block group for some
reason.  I've sent a patch to remove the WARN_ON() so that won't bother you
anymore.  You should probably rebalance to try and trim that block group down to
a reasonable size, but other than that your fs is a-ok.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]()
  2013-05-08 20:47                     ` Josef Bacik
@ 2013-05-13  8:33                       ` Alexander Skwar
  0 siblings, 0 replies; 14+ messages in thread
From: Alexander Skwar @ 2013-05-13  8:33 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs

Hello Josef

On Wed, May 8, 2013 at 10:47 PM, Josef Bacik <jbacik@fusionio.com> wrote:
> On Wed, May 08, 2013 at 11:34:40AM -0600, Alexander Skwar wrote:
>> Hello Josef
>>
>> Did you have a chance to look at that image? Did you find anything?
>>
>> Or should I simply create a new filesystem and forget about the issue?
>>
>
> So the file system isn't corrupt, you just got a giant block group for some
> reason.

Hmm...

Sure?

I did start a "btrfs balance" and it consistently fails. See my dmesg
output at http://pastebin.com/7XgAhZ1s

At first, there are a few WARNING messages:

[  300.422702] WARNING: at
/build/buildd/linux-3.8.0/fs/btrfs/delayed-ref.c:454
update_existing_ref+0x119/0x150 [btrfs]()

[  300.422960] WARNING: at
/build/buildd/linux-3.8.0/fs/btrfs/delayed-ref.c:454
update_existing_ref+0x119/0x150 [btrfs]()
…

But there's also an error:

[  300.425633] BTRFS error (device dm-5) in
__btrfs_inc_extent_ref:1935: Object already exists
[  300.425634] btrfs is forced readonly


What can I do? Other than destroying that filesystem?

Regards,

Alexander
-- 
=>        Google+ => http://plus.skwar.me         <==
=> Chat (Jabber/Google Talk) => a.skwar@gmail.com <==

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2013-05-13  8:34 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-04-30  6:37 WARNING: at fs/btrfs/free-space-cache.c:921 __btrfs_write_out_cache+0x6b9/0x9a0 [btrfs]() Alexander Skwar
2013-04-30  6:55 ` Helmut Hullen
2013-04-30  9:41   ` Hugo Mills
2013-04-30 11:51     ` Alexander Skwar
2013-04-30 13:58       ` Josef Bacik
2013-04-30 14:33         ` Alexander Skwar
2013-04-30 17:53           ` Josef Bacik
2013-05-01  6:39             ` Alexander Skwar
2013-05-01 18:57               ` Josef Bacik
2013-05-01 19:19                 ` Jon Nelson
2013-05-01 20:08                 ` Alexander Skwar
     [not found]                   ` <CADn-QaPh9EZjnbr9HoRKTMi8OUgnvfRdD7riEDZ0hpkcNRN93Q@mail.gmail.com>
2013-05-08 20:40                     ` Josef Bacik
2013-05-08 20:47                     ` Josef Bacik
2013-05-13  8:33                       ` Alexander Skwar

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