On Fri, 2023-12-08 at 14:19 -0500, Benjamin Coddington wrote:
> After commit 59464b262ff5 ("SUNRPC: SOFTCONN tasks should time out
> when on
> the sending list"), any 4.1 backchannel tasks placed on the sending
> queue
> would immediately return with -ETIMEDOUT since their req timers are
> zero.
> We can fix this by keeping a copy of the rpc_clnt's timeout params on
> the
> transport and using them to properly setup the timeouts on the v4.1
> backchannel tasks' req.
>
> Fixes: 59464b262ff5 ("SUNRPC: SOFTCONN tasks should time out when on
> the sending list")
> Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
> ---
> include/linux/sunrpc/xprt.h | 1 +
> net/sunrpc/clnt.c | 3 +++
> net/sunrpc/xprt.c | 23 ++++++++++++++---------
> 3 files changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/sunrpc/xprt.h
> b/include/linux/sunrpc/xprt.h
> index f85d3a0daca2..7565902053f3 100644
> --- a/include/linux/sunrpc/xprt.h
> +++ b/include/linux/sunrpc/xprt.h
> @@ -285,6 +285,7 @@ struct rpc_xprt {
> * items */
> struct list_head bc_pa_list; /* List of
> preallocated
> * backchannel
> rpc_rqst's */
> + struct rpc_timeout bc_timeout; /* backchannel
> timeout params */
> #endif /* CONFIG_SUNRPC_BACKCHANNEL */
>
> struct rb_root recv_queue; /* Receive queue */
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index d6805c1268a7..5891757c88b1 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -279,6 +279,9 @@ static struct rpc_xprt
> *rpc_clnt_set_transport(struct rpc_clnt *clnt,
> clnt->cl_autobind = 1;
>
> clnt->cl_timeout = timeout;
> +#if defined(CONFIG_SUNRPC_BACKCHANNEL)
> + memcpy(&xprt->bc_timeout, timeout, sizeof(struct
> rpc_timeout));
> +#endif
Hmm... The xprt can and will be shared among a number of rpc_clnt
instances. I therefore think we're better off doing this when we're
setting up the back channel.
i.e. probably doing it in nfs41_init_clientid() after we picked up the
lease time (but before we mark the client as ready), and then doing it
in nfs4_proc_bind_conn_to_session() if ever that gets called.
Note that we have to set the bc_timeout on all xprts that could act as
back channels, so you might want to use
rpc_clnt_iterate_for_each_xprt().
It might also be worth to look at Olga's trunking code, since I suspect
we might need to do something there when adding a new xprt to the
existing set.
> rcu_assign_pointer(clnt->cl_xprt, xprt);
> spin_unlock(&clnt->cl_lock);
>
> diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
> index 92301e32cda4..7dce780869fc 100644
> --- a/net/sunrpc/xprt.c
> +++ b/net/sunrpc/xprt.c
> @@ -653,9 +653,9 @@ static unsigned long
> xprt_abs_ktime_to_jiffies(ktime_t abstime)
> jiffies + nsecs_to_jiffies(-delta);
> }
>
> -static unsigned long xprt_calc_majortimeo(struct rpc_rqst *req)
> +static unsigned long xprt_calc_majortimeo(struct rpc_rqst *req,
> + const struct rpc_timeout *to)
> {
> - const struct rpc_timeout *to = req->rq_task->tk_client-
> >cl_timeout;
> unsigned long majortimeo = req->rq_timeout;
>
> if (to->to_exponential)
> @@ -667,9 +667,10 @@ static unsigned long xprt_calc_majortimeo(struct
> rpc_rqst *req)
> return majortimeo;
> }
>
> -static void xprt_reset_majortimeo(struct rpc_rqst *req)
> +static void xprt_reset_majortimeo(struct rpc_rqst *req,
> + const struct rpc_timeout *to)
> {
> - req->rq_majortimeo += xprt_calc_majortimeo(req);
> + req->rq_majortimeo += xprt_calc_majortimeo(req, to);
> }
>
> static void xprt_reset_minortimeo(struct rpc_rqst *req)
> @@ -677,7 +678,8 @@ static void xprt_reset_minortimeo(struct rpc_rqst
> *req)
> req->rq_minortimeo += req->rq_timeout;
> }
>
> -static void xprt_init_majortimeo(struct rpc_task *task, struct
> rpc_rqst *req)
> +static void xprt_init_majortimeo(struct rpc_task *task, struct
> rpc_rqst *req,
> + const struct rpc_timeout *to)
> {
> unsigned long time_init;
> struct rpc_xprt *xprt = req->rq_xprt;
> @@ -686,8 +688,9 @@ static void xprt_init_majortimeo(struct rpc_task
> *task, struct rpc_rqst *req)
> time_init = jiffies;
> else
> time_init = xprt_abs_ktime_to_jiffies(task-
> >tk_start);
> - req->rq_timeout = task->tk_client->cl_timeout->to_initval;
> - req->rq_majortimeo = time_init + xprt_calc_majortimeo(req);
> +
> + req->rq_timeout = to->to_initval;
> + req->rq_majortimeo = time_init + xprt_calc_majortimeo(req,
> to);
> req->rq_minortimeo = time_init + req->rq_timeout;
> }
>
> @@ -715,7 +718,7 @@ int xprt_adjust_timeout(struct rpc_rqst *req)
> } else {
> req->rq_timeout = to->to_initval;
> req->rq_retries = 0;
> - xprt_reset_majortimeo(req);
> + xprt_reset_majortimeo(req, to);
> /* Reset the RTT counters == "slow start" */
> spin_lock(&xprt->transport_lock);
> rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to-
> >to_initval);
> @@ -1888,7 +1891,7 @@ xprt_request_init(struct rpc_task *task)
> req->rq_snd_buf.bvec = NULL;
> req->rq_rcv_buf.bvec = NULL;
> req->rq_release_snd_buf = NULL;
> - xprt_init_majortimeo(task, req);
> + xprt_init_majortimeo(task, req, task->tk_client-
> >cl_timeout);
>
> trace_xprt_reserve(req);
> }
> @@ -1998,6 +2001,8 @@ xprt_init_bc_request(struct rpc_rqst *req,
> struct rpc_task *task)
> */
> xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
> xbufp->tail[0].iov_len;
> +
> + xprt_init_majortimeo(task, req, &req->rq_xprt->bc_timeout);
> }
> #endif
>
Otherwise, looks good.
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@xxxxxxxxxxxxxxx
