Re: [RFC] [PATCH] 2.5.35 patch for making DIO async

[Suparna Bhattacharya <suparna@in.ibm.com>]

On Thu, Sep 19, 2002 at 04:22:14PM +0530, Suparna Bhattacharya wrote:
> On Wed, Sep 18, 2002 at 01:47:06PM -0700, Badari Pulavarty wrote:
> > Ben,
> > 
> > aio_read/aio_write() are now working with a minor fix to fs/aio.c
> > 
> > io_submit_one():
> > 	
> > 	if (likely(EIOCBQUEUED == ret))
> > 
> > 		needs to be changed to
> > 
> > 	if (likely(-EIOCBQUEUED == ret))
> > 		  ^^^
> > 
> > 
> > I was wondering what happens to following case (I think this
> > happend in my test program).
> > 
> > Lets say, I did an sys_io_submit() and my test program did exit().
> > When the IO complete happend, it tried to do following and got
> > an OOPS in aio_complete().
> > 
> > 	if (ctx == &ctx->mm->default_kioctx) { 
> > 
> > I think "mm" is freed up, when process exited. Do you think this is
> > possible ?  How do we handle this ?
> 
> Do you see this only in the sync case ?
> init_sync_iocb ought to increment ctx->reqs_active, so that
> exit_aio waits for the iocb's to complete.

Sorry, guess in the sync case, exit_aio shouldn't happen since 
the current thread still has a reference to the mm. 

And your problem is with the io_submit case ... have to look closely
to find out why.

> 
> Regards
> Suparna
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