blk_iopoll_enabled

[Sagi Grimberg <sagig@dev.mellanox.co.il>]

Hey Jens,

So I'm looking at blk_iopoll for iSER & SRP and I have one gap I would 
like to get your input on.

In blk-iopoll.c I see:
int blk_iopoll_enabled = 1;
EXPORT_SYMBOL(blk_iopoll_enabled);

This is set to 1 and exported for everyone to condition and *modify* it.
The documentation says the user must check this when using blk_iopoll.

My question is why? it should always be true shouldn't it?
Moreover, isn't it better to protect it using a get() function of it?
can't someone set it to 0 and shutdown the lights on everyone else?

Thanks,

Sagi.