Re: [fs] inode_lru_isolate(): Move counter increment into spinlocksection

[Dave Chinner]

On Wed, Dec 18, 2013 at 07:24:46PM +0000, Christoph Lameter wrote:
> The counter increment in inode_lru_isolate is happening after
> spinlocks have been dropped with preemption on using __count_vm_events
> making counter increment races possible.

That's a nasty, undocumented problem that __count_vm_events() has.
Nobody who is modifying the fs/inode.c code is likely to know about
this, so just moving the code under an unrelated lock is not
sufficient to prevent this from happening again. Hence I'd prefer
that you just change it to use count_vm_events() rather than try to
be tricksy by replacing the landmine in the code that we've already
stepped on once.

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx
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