I see this was fixed in today's linux-next. That was quick. :)
regards,
dan caprenter
On Thu, Dec 05, 2019 at 02:00:35PM +0300, Dan Carpenter wrote:
> Hello Jens Axboe,
>
> The patch f67676d160c6: "io_uring: ensure async punted read/write
> requests copy iovec" from Dec 2, 2019, leads to the following static
> checker warning:
>
> fs/io_uring.c:2919 io_req_defer()
> warn: inconsistent returns 'irq'.
>
> fs/io_uring.c
> 2891 static int io_req_defer(struct io_kiocb *req)
> 2892 {
> 2893 struct io_ring_ctx *ctx = req->ctx;
> 2894 struct io_async_ctx *io;
> 2895 int ret;
> 2896
> 2897 /* Still need defer if there is pending req in defer list. */
> 2898 if (!req_need_defer(req) && list_empty(&ctx->defer_list))
> 2899 return 0;
> 2900
> 2901 io = kmalloc(sizeof(*io), GFP_KERNEL);
> 2902 if (!io)
> 2903 return -EAGAIN;
> 2904
> 2905 spin_lock_irq(&ctx->completion_lock);
> 2906 if (!req_need_defer(req) && list_empty(&ctx->defer_list)) {
> 2907 spin_unlock_irq(&ctx->completion_lock);
> 2908 kfree(io);
> 2909 return 0;
> 2910 }
> 2911
> 2912 ret = io_req_defer_prep(req, io);
> 2913 if (ret < 0)
> 2914 return ret;
>
> We need to spin_unlock_irq(&ctx->completion_lock); before returning.
> The question of if we need to kfree(io) is more complicated to me
> because I'm not sure how kiocb->ki_complete gets called...
>
> 2915
> 2916 trace_io_uring_defer(ctx, req, req->user_data);
> 2917 list_add_tail(&req->list, &ctx->defer_list);
> 2918 spin_unlock_irq(&ctx->completion_lock);
> 2919 return -EIOCBQUEUED;
> 2920 }
>
> regards,
> dan carpenter
