[PATCH 1/2] mtd: use refcount to prevent corruption

[Miquel Raynal]

Hi Alexander,

alexander.usyskin at intel.com wrote on Sun, 16 Jul 2023 06:29:02 +0000:

> > > With this patch applied, when I load up the module, I get the same 3
> > > devices:
> > > /dev/mtd0
> > > /dev/mtd0ro
> > > /dev/mtdblock0
> > >
> > > Upon removal, the below 2 devices still hang around:
> > > /dev/mtd0
> > > /dev/mtd0ro  
> >   
> Our use-case do not produce mtdblock, maybe there are some imbalances of get/put?
> I have somewhere version with pr_debug after every kref_get/put. That may help to catch where
> it missed, I hope.

I believe mtdblock is the good citizen here. Just disable
CONFIG_MTD_BLOCK from your configuration and you will likely observe
the same issue, just a bit narrowed, perhaps. Indeed, if you manage to
follow all the get/put calls it can help to find an imbalance.

Thanks,
Miquèl