Re: [PATCH v2] SUNRPC: Fixup v4.1 backchannel request timeouts
From: Trond Myklebust <hidden>
Date: 2023-12-09 09:55:11
On Fri, 2023-12-08 at 14:19 -0500, Benjamin Coddington wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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.hb/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.
quoted hunk ↗ jump to hunk
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 longxprt_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-quoted
cl_timeout;unsigned long majortimeo = req->rq_timeout; if (to->to_exponential)@@ -667,9 +667,10 @@ static unsigned long xprt_calc_majortimeo(structrpc_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-quoted
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-quoted
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-quoted
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@hammerspace.com