Re: 2.6.33-rc1: kernel BUG at fs/ext4/inode.c:1063 (sparc)

[Alexander Beregalov <a.beregalov@gmail.com>]

It seems Dmitry Torokhov has the same issue, Cc'ed.

2009/12/26 Dmitry Monakhov <dmonakhov@openvz.org>:
> Alexander Beregalov <a.beregalov@gmail.com> writes:
>
>>>> It seems I can easily reproduce it.
>>>> But I can't compile 2.6.33-rc2 :)
> BTW what sha1 of the git-commit you have used to reproduce
> the bug (2.6.33-rc1 HEAD has no this BUG_ON).
> This is important to me to know it, or just post the
> fs/ext4/inode.c file.

It was in the first post - 2f99f5c
There is only OCFS update between it and -rc2.

>>>>
>>>> scripts/kconfig/conf -s arch/sparc/Kconfig
>>>>   CHK     include/linux/version.h
>>>>   CHK     include/generated/utsrelease.h
>>>>   CALL    scripts/checksyscalls.sh
>>>>   CHK     include/generated/compile.h
>>>>   GZIP    kernel/config_data.gz
>>>>   CC      fs/configfs/inode.o
>>>>   IKCFG   kernel/config_data.h
>>>>   LD [M]  fs/btrfs/btrfs.o
>>>>   CC      kernel/configs.o
>>>> fs/btrfs/sysfs.o: file not recognized: File truncated
>>> This happens because of  delayed allocation. Each time BUG or
>>> unexpected power off happens during object files usually becomes
>>> broken. IMHO this is expected issue. Just recompile from beginning
>>> # make clean; make -j4
>>
>> It does not help, it still fails.
> Again strange, please run fsck. What about compile it from very
> beginning (start from unpacking tar-ball from kernel.org)
> Or may be compile it on another file-system(ext3 or
> ext4 with nodelalloc option)

I tried fsck, it did not find any problem, kernel build still fails after it.

>> I will try to crosscompile the kernel with Ted's patch on another host.

Here is output of 2.6.33-rc2 plus Ted's patch

EXT4-fs (sda1): inode #1387643: mdb_free (1) < mdb_claim (2) BUG

------------[ cut here ]------------
WARNING: at fs/ext4/inode.c:1067 ext4_get_blocks+0x3f0/0x440()
Modules linked in:
Call Trace:
 [0000000000456bb0] warn_slowpath_common+0x50/0xa0
 [0000000000456c1c] warn_slowpath_null+0x1c/0x40
 [0000000000545010] ext4_get_blocks+0x3f0/0x440
 [0000000000545420] mpage_da_map_blocks+0x80/0x800
 [0000000000546260] mpage_add_bh_to_extent+0x40/0x100
 [00000000005464cc] __mpage_da_writepage+0x1ac/0x220
 [00000000004a957c] write_cache_pages+0x19c/0x380
 [0000000000545e1c] ext4_da_writepages+0x27c/0x680
 [00000000004a97ec] do_writepages+0x2c/0x60
 [00000000004f952c] writeback_single_inode+0xcc/0x3c0
 [00000000004fa438] writeback_inodes_wb+0x338/0x500
 [00000000004fa748] wb_writeback+0x148/0x220
 [00000000004fab60] wb_do_writeback+0x240/0x260
 [00000000004fabec] bdi_writeback_task+0x6c/0xc0
 [00000000004b6fb0] bdi_start_fn+0x70/0xe0
 [000000000047036c] kthread+0x6c/0x80
---[ end trace 46a56c443941c84d ]---

>>
> It is sad, but i still can not reproduce your bug.
> At this time i've tested following configurations:
> system   :    2.6.33-rc2, x86 two cores cpu with 2GB of ram
> block dev: real sata drive, loopdev over tmpfs
> mkfs     : 4k and 1k blocksize
> mount    : w/o quota, quota, journaled quota
> quota    : both ON and OFF states
> fs-load  : - fsstress with 1,4,16,32 concurrent tasks
>           - kernel compilation -j4, -j32
>           - In fact currently my mail-dir is under quota control.
> Please clarify your use-case:
> 0) Your system speciffication: cpu_num, mem_size, page_size(i guess 8k)
>   block device.
UltraSparc IIe, UP, 2Gb, 8kb, real SCSI disk (sym53c8xx driver)
> 1) mkfs options
I do not remember.
Perhaps dumpe2fs can help

root@v120 ~ # dumpe2fs -h /dev/sda1
dumpe2fs 1.41.9 (22-Aug-2009)
Filesystem volume name:   <none>
Last mounted on:          /
Filesystem UUID:          b34f302e-78a3-4f80-bae6-31639456216c
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index
filetype needs_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              2113536
Block count:              8448000
Reserved block count:     422400
Free blocks:              6661110
Free inodes:              1861302
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      1021
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Filesystem created:       Tue Nov 10 00:44:17 2009
Last mount time:          Sun Dec 27 20:05:48 2009
Last write time:          Sat Dec 26 10:59:00 2009
Mount count:              3
Maximum mount count:      21
Last checked:             Sat Dec 26 06:07:50 2009
Check interval:           15552000 (6 months)
Next check after:         Thu Jun 24 07:07:50 2010
Lifetime writes:          30 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      ae1ec2f1-0f86-4f26-ace5-eb656fd25709
Journal backup:           inode blocks
Journal size:             128M


> 2) mount options
noatime
> 3) quota options (if any)
No
> 4) your fs load test-case
Have not tried to find a simpler testcase yet.
make CROSS_COMPILE="ccache sparc64-unknown-linux-gnu-" -j4 zImage modules

Hm, perhaps ccache is the real trigger of the problem.

> 5) How long does it takes you to reproduce the bug.
Few seconds (~5)