Re: kernel BUG at fs/btrfs/extent-tree.c:6164!

[liubo <liubo2009@cn.fujitsu.com>]

On 06/06/2011 04:33 PM, Tsutomu Itoh wrote:
> Hi,
> 
> I encountered following panic using 'btrfs-unstable + for-linus'
> kernel.
> 
> I ran "btrfs fi bal /test5" command, and mount option of /test5
> is as follows:
> 
>  /dev/sdc3 on /test5 type btrfs (rw,space_cache,compress=lzo,inode_cache)
> 

So, just a "btrfs fi bal" would lead to the bug?

I've figured out the warnings, but not reproduced the bug yet...
I used 'btrfs-unstable + for-linus" whose top commit is

commit aa0467d8d2a00e75b2bb6a56a4ee6d70c5d1928f
Author: David Sterba <dsterba@suse.cz>
Date:   Fri Jun 3 16:29:08 2011 +0200

    btrfs: fix uninitialized variable warning
    
and tried on 1) a single disk, 2) 2 disks and 3) 4 disks respectively,
but none of them leaded to the below bug.

I guess maybe I miss something to reproduce it?

thanks,
liubo

> Thanks,
> Tsutomu
> 
> =================================================================
> 
> btrfs: relocating block group 23383244800 flags 20
> btrfs: found 2959 extents
> ------------[ cut here ]------------
> WARNING: at fs/btrfs/transaction.c:213 start_transaction+0x2a7/0x2b0 [btrfs]()
> Hardware name: PRIMERGY
> Modules linked in: autofs4 sunrpc 8021q garp stp llc cpufreq_ondemand acpi_cpufr
> eq freq_table mperf ipv6 btrfs zlib_deflate crc32c libcrc32c ext3 jbd dm_mirror
> dm_region_hash dm_log dm_mod kvm uinput ppdev parport_pc parport sg pcspkr i2c_i
> 801 i2c_core iTCO_wdt iTCO_vendor_support tg3 shpchp pci_hotplug i3000_edac edac
> _core ext4 mbcache jbd2 crc16 sd_mod crc_t10dif sr_mod cdrom megaraid_sas pata_a
> cpi ata_generic ata_piix libata scsi_mod floppy [last unloaded: microcode]
> Pid: 23781, comm: btrfs Tainted: G        W   2.6.39btrfs-test+ #4
> Call Trace:
>  [<ffffffff8106004f>] warn_slowpath_common+0x7f/0xc0
>  [<ffffffff810600aa>] warn_slowpath_null+0x1a/0x20
>  [<ffffffffa0337047>] start_transaction+0x2a7/0x2b0 [btrfs]
>  [<ffffffffa035498d>] ? btrfs_wait_ordered_range+0x10d/0x160 [btrfs]
>  [<ffffffffa0337323>] btrfs_start_transaction+0x13/0x20 [btrfs]
>  [<ffffffffa033bbca>] btrfs_evict_inode+0x11a/0x260 [btrfs]
>  [<ffffffff811687f8>] evict+0x78/0x170
>  [<ffffffff81168c92>] iput+0xe2/0x1a0
>  [<ffffffffa031f171>] btrfs_remove_block_group+0x141/0x3c0 [btrfs]
>  [<ffffffffa035e6ea>] btrfs_relocate_chunk+0x54a/0x670 [btrfs]
>  [<ffffffffa0357668>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
>  [<ffffffffa031be51>] ? btrfs_previous_item+0xb1/0x150 [btrfs]
>  [<ffffffffa035f43a>] btrfs_balance+0x21a/0x2b0 [btrfs]
>  [<ffffffff8115dc41>] ? path_openat+0x101/0x3d0
>  [<ffffffffa03685bc>] btrfs_ioctl+0x51c/0xc40 [btrfs]
>  [<ffffffff8111e358>] ? handle_mm_fault+0x148/0x270
>  [<ffffffff814809e8>] ? do_page_fault+0x1d8/0x4b0
>  [<ffffffff81160d6a>] do_vfs_ioctl+0x9a/0x540
>  [<ffffffff811612b1>] sys_ioctl+0xa1/0xb0
>  [<ffffffff81484ec2>] system_call_fastpath+0x16/0x1b
> ---[ end trace e5c5cb2e98a3cd1a ]---
> btrfs: relocating block group 20971520 flags 18
> btrfs: relocating block group 34925969408 flags 18
> btrfs: found 1 extents
> ------------[ cut here ]------------
> kernel BUG at fs/btrfs/extent-tree.c:6164!
> invalid opcode: 0000 [#1] SMP
> last sysfs file: /sys/kernel/mm/ksm/run
> CPU 0
> Modules linked in: autofs4 sunrpc 8021q garp stp llc cpufreq_ondemand acpi_cpufreq freq_table mperf ipv6 btrfs zlib_deflate crc32c libcrc32c ext3 jbd dm_mirror dm_region_hash dm_log dm_mod kvm uinput ppdev parport_pc parport sg pcspkr i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support tg3 shpchp pci_hotplug i3000_edac edac_core ext4 mbcache jbd2 crc16 sd_mod crc_t10dif sr_mod cdrom megaraid_sas pata_acpi ata_generic ata_piix libata scsi_mod floppy [last unloaded: microcode]
> 
> Pid: 4109, comm: btrfs Tainted: G        W   2.6.39btrfs-test+ #4 FUJITSU-SV      PRIMERGY            /D2399
> RIP: 0010:[<ffffffffa0325b95>]  [<ffffffffa0325b95>] walk_up_proc+0x375/0x420 [btrfs]
> RSP: 0018:ffff8801801eb9c8  EFLAGS: 00010286
> RAX: 0000000000000005 RBX: ffff880167a70140 RCX: fffffffffffffff8
> RDX: ffff8801801ea000 RSI: ffff880000000000 RDI: ffff880194909fa8
> RBP: ffff8801801eba18 R08: 0000000000000000 R09: 0000000000000005
> R10: 0000000000000001 R11: ffff880194909fa8 R12: 0000000000000000
> R13: ffff88013973d000 R14: ffff88015ad4d9a0 R15: ffff880042203920
> FS:  00007fa86bcb9740(0000) GS:ffff88019fc00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: 00000033cf60b0c0 CR3: 0000000181cf7000 CR4: 00000000000006f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process btrfs (pid: 4109, threadinfo ffff8801801ea000, task ffff88011a4914a0)
> Stack:
>  ffff8801801eba18 ffff880194909fa8 ffff880100000000 ffffffffa03280e8
>  ffff8801801eba58 ffff88015ad4d9a0 0000000000000000 0000000000000000
>  ffff8801801ea000 ffff880167a70140 ffff8801801eba78 ffffffffa0325d71
> Call Trace:
>  [<ffffffffa03280e8>] ? btrfs_run_delayed_refs+0xc8/0x210 [btrfs]
>  [<ffffffffa0325d71>] walk_up_tree+0x131/0x1b0 [btrfs]
>  [<ffffffffa03260b0>] btrfs_drop_snapshot+0x2c0/0x5c0 [btrfs]
>  [<ffffffffa03328b0>] ? btrfs_read_fs_root_no_name+0x1b0/0x280 [btrfs]
>  [<ffffffffa037b45f>] merge_reloc_roots+0xdf/0x150 [btrfs]
>  [<ffffffffa037f311>] relocate_block_group+0x481/0x660 [btrfs]
>  [<ffffffffa0334d15>] ? btrfs_clean_old_snapshots+0x35/0x150 [btrfs]
>  [<ffffffffa037f6a3>] btrfs_relocate_block_group+0x1b3/0x2e0 [btrfs]
>  [<ffffffffa0368d80>] ? btrfs_tree_unlock+0x50/0x50 [btrfs]
>  [<ffffffffa035e22b>] btrfs_relocate_chunk+0x8b/0x670 [btrfs]
>  [<ffffffffa031303d>] ? btrfs_set_path_blocking+0x3d/0x50 [btrfs]
>  [<ffffffffa0357668>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
>  [<ffffffffa031be51>] ? btrfs_previous_item+0xb1/0x150 [btrfs]
>  [<ffffffffa0357668>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
>  [<ffffffffa035f43a>] btrfs_balance+0x21a/0x2b0 [btrfs]
>  [<ffffffff8115dc41>] ? path_openat+0x101/0x3d0
>  [<ffffffffa03685bc>] btrfs_ioctl+0x51c/0xc40 [btrfs]
>  [<ffffffff8111e358>] ? handle_mm_fault+0x148/0x270
>  [<ffffffff814809e8>] ? do_page_fault+0x1d8/0x4b0
>  [<ffffffff81160d6a>] do_vfs_ioctl+0x9a/0x540
>  [<ffffffff811612b1>] sys_ioctl+0xa1/0xb0
>  [<ffffffff81484ec2>] system_call_fastpath+0x16/0x1b
> Code: fe ff ff 0f 1f 00 4c 89 df 31 c9 4c 89 fa 4c 89 ee 44 89 55 c0 4c 89 5d b8 e8 c8 d5 ff ff 4c 8b 5d b8 44 8b 55 c0 e9 85 fe ff ff <0f> 0b eb fe 0f 1f 80 00 00 00 00 65 48 8b 14 25 c8 cc 00 00 48
> RIP  [<ffffffffa0325b95>] walk_up_proc+0x375/0x420 [btrfs]
>  RSP <ffff8801801eb9c8>
> 
> 
>