Jffs2 soft lockup on 2.6.31-rc5

[Felix Radensky]

Joakim Tjernlund wrote:
>> Hi,
>>
>> I'm getting soft lockups on Freescale MPC8536DS board running 2.6.31-rc5.
>> MTD device is 60M partition on Spansion 128MB NOR flash (S29GL01GP).
>>
>> To reproduce the problem, I run
>>
>> flash_eraseall /dev/mtd4
>> mount -t jffs2 /dev/mtdblock4 /mnt
>> sync
>>
>> The lockup messages look like this:
>>
>> INFO: task sync:1096 blocked for more than 120 seconds.
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
>> Call Trace:
>> [df04dd50] [28022248] 0x28022248 (unreliable)
>> [df04de10] [c00078e4] __switch_to+0x64/0xd0
>> [df04de20] [c029df08] schedule+0x188/0x2e0
>> [df04de50] [c029ebc8] __mutex_lock_slowpath+0xd4/0x1f8
>> [df04dea0] [c029ed04] mutex_lock+0x18/0x34
>> [df04dec0] [c007ed64] lock_super+0x28/0x38
>> [df04ded0] [c0111148] jffs2_write_super+0x1c/0x6c
>> [df04dee0] [c01111b0] jffs2_sync_fs+0x18/0x4c
>> [df04df00] [c009e70c] __sync_filesystem+0x3c/0x5c
>> [df04df10] [c009e7f8] sync_filesystems+0xcc/0x10c
>> [df04df30] [c009e91c] sys_sync+0x1c/0x50
>> [df04df40] [c000f7e4] ret_from_syscall+0x0/0x3c
>>
>>
>> The system does not lock completely, the sync returns after 2 lockup
>> messages
>> and jffs2 partition is fully  usable.
>>
>> The problem is not reproducible if I use ubifs or just copy data to
>> /dev/mtd4.
>> So it seems the problem is related to jffs2.  Any ideas what can be
>> wrong and
>> how to fix it  ?
>>     
>
> My guess is that jffs2 is busy reerasing all blocks and marking them with clean markers.
> Can you make flash_eraseall write JFFS2 clean markers after erasing the block?
>   
You mean, using flash_eraseall -j ? I thought it's always safer to use 
erase+mount+sync,
as this way there's no chance to have mismatch in clean marker layout. 
Also, there
are no lockups with 2.6.28.

Felix.
>       Jocke
>
>