Jffs2 soft lockup on 2.6.31-rc5

[Felix Radensky]

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  ?

Thanks.

Felix.