Re: [PATCH 11/16] io_uring: batch io_kiocb allocation

On 1/9/19 12:03 PM, Christoph Hellwig wrote:

On Wed, Jan 09, 2019 at 09:57:59AM -0700, Jens Axboe wrote:

quoted

On 1/9/19 5:13 AM, Christoph Hellwig wrote:

quoted

quoted

+	if (!state)
+		req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);

Just return an error here if kmem_cache_alloc fails.

quoted

+	if (req)
+		io_req_init(ctx, req);

Because all the other ones can't reached this with a NULL req.

This is different in the current tree, since I properly fixed the
ctx ref issue.

Your tree does a percpu_ref_tryget very first, and then leaks that if
kmem_cache_alloc_bulk fails, and also is inconsistent for NULL vs
ERR_PTR returns.  I think you want something like this on top:

I fixed it up while doing the rebase already. Just haven't pushed anything
out until I've had a chance to run it through testing.

-- 
Jens Axboe