jffs2 filesystem: possible circular locking dependency detected

[Brian Norris]

On Wed, Feb 8, 2012 at 12:09 PM, Thomas Gleixner <tglx at linutronix.de> wrote:
> On Wed, 8 Feb 2012, Darcy Watkins wrote:
>> [   20.932000] =======================================================
>> [   20.932000] [ INFO: possible circular locking dependency detected ]
>> [   20.932000] 3.0.18-rt34 #41
>> [   20.932000] -------------------------------------------------------
>> [   20.932000] depmod/734 is trying to acquire lock:
>> [   20.932000]  (&mm->mmap_sem){++++++}, at: [<800e82d0>] might_fault+0x4c/0xa4
>> [   20.932000]
>> [   20.932000] but task is already holding lock:
>> [   20.932000]  (&f->sem){+.+.+.}, at: [<80184f88>] jffs2_readdir+0x108/0x1c0
>> [   20.932000]
>> [   20.932000] which lock already depends on the new lock.
>
> Classic ABBA deadlock. I don't think it's RT specific, but I might be
> wrong as usual. Will have a look later this week, when noone beats me.

Looks like someone beat you :) Josh Cartwright has a patch here:
http://lists.infradead.org/pipermail/linux-mtd/2012-February/039787.html

Testing is always helpful to the MTD maintainers!

Brian