Re: [PATCH 10/33] aio: do fget() after aio_get_req()

[Jeff Moyer]

Kent Overstreet <koverstreet@xxxxxxxxxx> writes:

> aio_get_req() will fail if we have the maximum number of requests
> outstanding, which depending on the application may not be uncommon.  So
> avoid doing an unnecessary fget().


> diff --git a/fs/aio.c b/fs/aio.c
> index 2637555..4f23d43 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -587,6 +587,8 @@ static inline void really_put_req(struct kioctx *ctx, struct kiocb *req)
>  {
>  	assert_spin_locked(&ctx->ctx_lock);
>  
> +	if (req->ki_filp)
> +		fput(req->ki_filp);
>  	if (req->ki_eventfd != NULL)
>  		eventfd_ctx_put(req->ki_eventfd);
>  	if (req->ki_dtor)
[snip]
> @@ -618,8 +617,6 @@ static void __aio_put_req(struct kioctx *ctx, struct kiocb *req)
>  	req->ki_cancel = NULL;
>  	req->ki_retry = NULL;
>  
> -	fput(req->ki_filp);
> -	req->ki_filp = NULL;
>  	really_put_req(ctx, req);
>  }

So you've removed the setting of req->ki_filp to NULL here, and I think
it's okay.  The only function called after that which could possibly be
tripped up is req->ki_dtor.  That function has no business looking at
ki_filp, I think (and the only in-tree user does not look at it).

Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/