[PATCH v1 19/23] cachefiles: implement .demand_read() for demand read

[Matthew Wilcox]

On Mon, Dec 27, 2021 at 08:54:40PM +0800, Jeffle Xu wrote:
> +	spin_lock(&cache->reqs_lock);
> +	ret = idr_alloc(&cache->reqs, req, 0, 0, GFP_KERNEL);

GFP_KERNEL while holding a spinlock?

You should be using an XArray instead of an IDR in new code anyway.