Re: kernel BUG at /home/apw/COD/linux/fs/btrfs/inode.c:3123!

[Tomasz Chmielewski <tch@virtall.com>]

On 2015-01-07 15:58, Satoru Takeuchi wrote:

>> Create subvolume './subvolume'
>> # dd if=/dev/urandom of=bigfile.img bs=64k
> 
> Does it really this command? I consider it will fill up
> whole /dev/vdb.

It normally would fill the fs if left for long, but I've pressed ctrl+c 
after about 6 GB.


> And is it not subvolume/bigfile.img
> but bigfile.img?

If I recall correctly, it was not inside the subvolume.


(...)

>> 3127377920 bytes (3.1 GB) copied, 194.641 s, 16.1 MB/s
> 
> If bigfile.img is just under /mnt/test, I can't understand
> why this command succeeded to write more 3 GiB.

The previous command wrote 6 GB, this one wrote 3.1 GB - there was still 
plenty of free space.


(...)

>> # dd if=/dev/urandom of=bigfile3.img bs=64k
>> ^C3617580+0 records in
>> 3617579+0 records out
>> 237081657344 bytes (237 GB) copied, 14796 s, 16.0 MB/s
> 
> It's too.

This one was also left running for long, followed by ctrl+c (note the ^C 
in my pasted output).
We didn't fill the fs 100% in any of these cases.


>> # df -h
>> Filesystem      Size  Used Avail Use% Mounted on
>> (...)
>> /dev/vdb        256G  230G   25G  91% /mnt/test
>> 
>> 
>> # btrfs qgroup show /mnt/test
>> qgroupid rfer         excl
>> -------- ----         ----
>> 0/5      16384        16384
>> 0/257    245960245248 245960245248
>> 
>> # ls -l
>> total 240451584
>> -rw-r--r-- 1 root root   3127377920 Dec 19 20:06 bigfile2.img
>> -rw-r--r-- 1 root root 237081657344 Dec 20 00:15 bigfile3.img
>> -rw-r--r-- 1 root root   6013386752 Dec 19 20:02 bigfile.img
>> 
>> # rm bigfile3.img
>> 
>> # sync
>> 
>> # dmesg
>> (...)
>> [   95.055420] BTRFS: device fsid 97f98279-21e7-4822-89be-3aed9dc05f2c 
>> devid 1 transid 3 /dev/vdb
>> [  118.446509] BTRFS info (device vdb): disk space caching is enabled
>> [  118.446518] BTRFS: flagging fs with big metadata feature
>> [  118.452176] BTRFS: creating UUID tree
>> [  575.189412] BTRFS info (device vdb): qgroup scan completed
>> [15948.234826] ------------[ cut here ]------------
>> [15948.234883] kernel BUG at 
>> /home/apw/COD/linux/fs/btrfs/inode.c:3123!
>> [15948.234906] invalid opcode: 0000 [#1] SMP
>> [15948.234925] Modules linked in: nf_log_ipv6 ip6t_REJECT 
>> nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter 
>> ip6_tables nf_log_ipv4 nf_log_common xt_LOG ipt_REJECT nf_reject_ipv4 
>> xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack 
>> iptable_filter ip_tables x_tables dm_crypt btrfs xor crct10dif_pclmul 
>> crc32_pclmul ghash_clmulni_intel aesni_intel ppdev aes_x86_64 lrw 
>> raid6_pq gf128mul glue_helper ablk_helper cryptd serio_raw mac_hid 
>> pvpanic 8250_fintek parport_pc i2c_piix4 lp parport psmouse qxl ttm 
>> floppy drm_kms_helper drm
>> [15948.235172] CPU: 0 PID: 3274 Comm: btrfs-cleaner Not tainted 
>> 3.18.1-031801-generic #201412170637
>> [15948.235193] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), 
>> BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 
>> 04/01/2014
>> [15948.235222] task: ffff880036708a00 ti: ffff88007b97c000 task.ti: 
>> ffff88007b97c000
>> [15948.235240] RIP: 0010:[<ffffffffc0458ec9>]  [<ffffffffc0458ec9>] 
>> btrfs_orphan_add+0x1a9/0x1c0 [btrfs]
>> [15948.235305] RSP: 0018:ffff88007b97fc98  EFLAGS: 00010286
>> [15948.235318] RAX: 00000000ffffffe4 RBX: ffff88007b80a800 RCX: 
>> 0000000000000000
>> [15948.235333] RDX: 000000000000219e RSI: 0000000000040000 RDI: 
>> ffff880079418138
>> [15948.235349] RBP: ffff88007b97fcd8 R08: ffff88007fc1cae0 R09: 
>> ffff88007ad272d0
>> [15948.235366] R10: 0000000000000000 R11: 0000000000000010 R12: 
>> ffff88007a2d9500
>> [15948.235381] R13: ffff8800027d60e0 R14: ffff88007b80ac58 R15: 
>> 0000000000000001
>> [15948.235401] FS:  0000000000000000(0000) GS:ffff88007fc00000(0000) 
>> knlGS:0000000000000000
>> [15948.235418] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [15948.235432] CR2: 00007f0489ff0000 CR3: 000000007a5e0000 CR4: 
>> 00000000001407f0
>> [15948.235464] Stack:
>> [15948.235473]  ffff88007b97fcd8 ffffffffc0497acf ffff88007b809800 
>> ffff88003c207400
>> [15948.235498]  ffff88007b809800 ffff88007ad272d0 ffff88007a2d9500 
>> 0000000000000001
>> [15948.235521]  ffff88007b97fd58 ffffffffc04412e0 ffff880079418000 
>> 00000004c0427fea
>> [15948.235551] Call Trace:
>> [15948.235601]  [<ffffffffc0497acf>] ? 
>> lookup_free_space_inode+0x4f/0x100 [btrfs]
>> [15948.235642]  [<ffffffffc04412e0>] 
>> btrfs_remove_block_group+0x140/0x490 [btrfs]
>> [15948.235693]  [<ffffffffc047bde5>] btrfs_remove_chunk+0x245/0x380 
>> [btrfs]
>> [15948.235731]  [<ffffffffc0441866>] 
>> btrfs_delete_unused_bgs+0x236/0x270 [btrfs]
>> [15948.235771]  [<ffffffffc044ad6c>] cleaner_kthread+0x12c/0x190 
>> [btrfs]
>> [15948.235806]  [<ffffffffc044ac40>] ? 
>> btrfs_destroy_all_delalloc_inodes+0x120/0x120 [btrfs]
>> [15948.235844]  [<ffffffff81093a09>] kthread+0xc9/0xe0
>> [15948.235872]  [<ffffffff81093940>] ? flush_kthread_worker+0x90/0x90
>> [15948.235900]  [<ffffffff817b36bc>] ret_from_fork+0x7c/0xb0
>> [15948.235919]  [<ffffffff81093940>] ? flush_kthread_worker+0x90/0x90
>> [15948.235933] Code: e8 7d a1 fc ff 8b 45 c8 e9 6d ff ff ff 0f 1f 44 
>> 00 00 f0 41 80 65 80 fd 4c 89 ef 89 45 c8 e8 cf 20 fe ff 8b 45 c8 e9 
>> 48 ff ff ff <0f> 0b 4c 89 f7 45 31 f6 e8 8a a2 35 c1 e9 f9 fe ff ff 0f 
>> 1f 44
>> [15948.236017] RIP  [<ffffffffc0458ec9>] btrfs_orphan_add+0x1a9/0x1c0 
>> [btrfs]
>> [15948.236017]  RSP <ffff88007b97fc98>
>> [15948.761942] ---[ end trace 0ccd21c265dce56b ]---
>> 
>> # ls
>> bigfile2.img  bigfile.img
>> 
>> # touch 1
>> (...never returned...)
>> 

Tomasz Chmielewski
http://www.sslrack.com