Re: [PATCH] xprtrdma: Ensure connect worker is awoken after connect error

[Chuck Lever <chuck.lever@oracle.com>]

Anna, please drop this one. It appears to trigger a particularly nasty
use-after-free. I'll follow up with a more complete fix soon.

(Yes, a wake-up on connect errors is indeed necessary... but the connect
worker needs to be re-organized to deal properly with it).


> On Jun 21, 2020, at 10:59 AM, Chuck Lever <chuck.lever@oracle.com> wrote:
> 
> From: Dan Aloni <dan@kernelim.com>
> 
> The connect worker sleeps waiting for either successful connection
> establishment or an error. Commit e28ce90083f0 ("xprtrdma: kmalloc
> rpcrdma_ep separate from rpcrdma_xprt") mistakenly removed the
> wake-up in cases when connection establishment fails.
> 
> Fixes: e28ce90083f0 ("xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt")
> Signed-off-by: Dan Aloni <dan@kernelim.com>
> [ cel: rebased on recent fixes to 5.8-rc; patch description rewritten ]
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
> net/sunrpc/xprtrdma/verbs.c |    1 +
> 1 file changed, 1 insertion(+)
> 
> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
> index 2198c8ec8dff..54c6809bf06e 100644
> --- a/net/sunrpc/xprtrdma/verbs.c
> +++ b/net/sunrpc/xprtrdma/verbs.c
> @@ -296,6 +296,7 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
> 		ep->re_connect_status = -ECONNABORTED;
> disconnected:
> 		rpcrdma_force_disconnect(ep);
> +		wake_up_all(&ep->re_connect_wait);
> 		return rpcrdma_ep_put(ep);
> 	default:
> 		break;
> 

--
Chuck Lever