RE: [patch] aio: fix buggy put_ioctx call in aio_complete

["Chen, Kenneth W" <kenneth.w.chen@intel.com>]

jmoyer@redhat.com wrote on Thursday, December 21, 2006 8:56 AM
> kenneth.w.chen> I think I'm going to abandon this whole synchronize thing
> kenneth.w.chen> and going to put the wake up call inside ioctx_lock spin
> kenneth.w.chen> lock along with the other patch you mentioned above in the
> kenneth.w.chen> waiter path.  On top of that, I have another patch attempts
> kenneth.w.chen> to perform wake-up only when the waiter can truly proceed
> kenneth.w.chen> in aio_read_evt so dribbling I/O completion doesn't
> kenneth.w.chen> inefficiently waking up waiter too frequently and only to
> kenneth.w.chen> have waiter put back to sleep again. I will dig that up and
> kenneth.w.chen> experiment.
> 
> In the mean time, can't we simply take the context lock in
> wait_for_all_aios?  Unless I missed something, I think that will address
> the reference count problem.

Take ioctx_lock is one part, the other part is to move

	spin_unlock_irqrestore(&ctx->ctx_lock, flags);

in aio_complete all the way down to the end of the function, after wakeup
and put_ioctx.  But then the ref counting on ioctx in aio_complete path is
Meaningless, which is the thing I'm trying to remove.