> On Mar 3, 2023, at 4:08 PM, Benjamin Coddington <bcodding@xxxxxxxxxx> wrote:
>
> Fix a race where kthread_stop() may prevent the threadfn from ever getting
> called. If that happens the svc_rqst will not be cleaned up.
>
> Fixes: ed6473ddc704 ("NFSv4: Fix callback server shutdown")
> Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
> ---
> net/sunrpc/svc.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> index 1fd3f5e57285..fea7ce8fba14 100644
> --- a/net/sunrpc/svc.c
> +++ b/net/sunrpc/svc.c
> @@ -798,6 +798,7 @@ svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
> static int
> svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
> {
> + struct svc_rqst *rqstp;
> struct task_struct *task;
> unsigned int state = serv->sv_nrthreads-1;
>
> @@ -806,7 +807,10 @@ svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
> task = choose_victim(serv, pool, &state);
> if (task == NULL)
> break;
> - kthread_stop(task);
> + rqstp = kthread_data(task);
> + /* Did we lose a race to svo_function threadfn? */
> + if (kthread_stop(task) == -EINTR)
> + svc_exit_thread(rqstp);
> nrservs++;
> } while (nrservs < 0);
> return 0;
> --
> 2.31.1
>
Seems sensible, applied. Is there a bugzilla link that should be included?
--
Chuck Lever
