From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit e86be3a04bc4aeaf12f93af35f08f8d4385bcd98 ]
Ensure that we fix the XPRT_CONGESTED starvation issue for RDMA as well as socket based transports. Ensure we always initialise the request after waking up from the backlog list.
Fixes: e877a88d1f06 ("SUNRPC in case of backlog, hand free slots directly to waiting task") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/sunrpc/xprt.h | 2 ++ net/sunrpc/xprt.c | 58 ++++++++++++++++----------------- net/sunrpc/xprtrdma/transport.c | 12 +++---- net/sunrpc/xprtrdma/verbs.c | 18 ++++++++-- net/sunrpc/xprtrdma/xprt_rdma.h | 1 + 5 files changed, 52 insertions(+), 39 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index d2e97ee802af..8a063b2b944d 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -367,6 +367,8 @@ struct rpc_xprt * xprt_alloc(struct net *net, size_t size, unsigned int num_prealloc, unsigned int max_req); void xprt_free(struct rpc_xprt *); +void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task); +bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
static inline int xprt_enable_swap(struct rpc_xprt *xprt) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 7f9fa1c66627..dc9207c1ff07 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1603,11 +1603,18 @@ xprt_transmit(struct rpc_task *task) spin_unlock(&xprt->queue_lock); }
-static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) +static void xprt_complete_request_init(struct rpc_task *task) +{ + if (task->tk_rqstp) + xprt_request_init(task); +} + +void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) { set_bit(XPRT_CONGESTED, &xprt->state); - rpc_sleep_on(&xprt->backlog, task, NULL); + rpc_sleep_on(&xprt->backlog, task, xprt_complete_request_init); } +EXPORT_SYMBOL_GPL(xprt_add_backlog);
static bool __xprt_set_rq(struct rpc_task *task, void *data) { @@ -1615,14 +1622,13 @@ static bool __xprt_set_rq(struct rpc_task *task, void *data)
if (task->tk_rqstp == NULL) { memset(req, 0, sizeof(*req)); /* mark unused */ - task->tk_status = -EAGAIN; task->tk_rqstp = req; return true; } return false; }
-static bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req) +bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req) { if (rpc_wake_up_first(&xprt->backlog, __xprt_set_rq, req) == NULL) { clear_bit(XPRT_CONGESTED, &xprt->state); @@ -1630,6 +1636,7 @@ static bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req) } return true; } +EXPORT_SYMBOL_GPL(xprt_wake_up_backlog);
static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) { @@ -1639,7 +1646,7 @@ static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task goto out; spin_lock(&xprt->reserve_lock); if (test_bit(XPRT_CONGESTED, &xprt->state)) { - rpc_sleep_on(&xprt->backlog, task, NULL); + xprt_add_backlog(xprt, task); ret = true; } spin_unlock(&xprt->reserve_lock); @@ -1808,10 +1815,6 @@ xprt_request_init(struct rpc_task *task) struct rpc_xprt *xprt = task->tk_xprt; struct rpc_rqst *req = task->tk_rqstp;
- if (req->rq_task) - /* Already initialized */ - return; - req->rq_task = task; req->rq_xprt = xprt; req->rq_buffer = NULL; @@ -1872,10 +1875,8 @@ void xprt_retry_reserve(struct rpc_task *task) struct rpc_xprt *xprt = task->tk_xprt;
task->tk_status = 0; - if (task->tk_rqstp != NULL) { - xprt_request_init(task); + if (task->tk_rqstp != NULL) return; - }
task->tk_status = -EAGAIN; xprt_do_reserve(xprt, task); @@ -1900,24 +1901,21 @@ void xprt_release(struct rpc_task *task) }
xprt = req->rq_xprt; - if (xprt) { - xprt_request_dequeue_xprt(task); - spin_lock(&xprt->transport_lock); - xprt->ops->release_xprt(xprt, task); - if (xprt->ops->release_request) - xprt->ops->release_request(task); - xprt_schedule_autodisconnect(xprt); - spin_unlock(&xprt->transport_lock); - if (req->rq_buffer) - xprt->ops->buf_free(task); - xdr_free_bvec(&req->rq_rcv_buf); - xdr_free_bvec(&req->rq_snd_buf); - if (req->rq_cred != NULL) - put_rpccred(req->rq_cred); - if (req->rq_release_snd_buf) - req->rq_release_snd_buf(req); - } else - xprt = task->tk_xprt; + xprt_request_dequeue_xprt(task); + spin_lock(&xprt->transport_lock); + xprt->ops->release_xprt(xprt, task); + if (xprt->ops->release_request) + xprt->ops->release_request(task); + xprt_schedule_autodisconnect(xprt); + spin_unlock(&xprt->transport_lock); + if (req->rq_buffer) + xprt->ops->buf_free(task); + xdr_free_bvec(&req->rq_rcv_buf); + xdr_free_bvec(&req->rq_snd_buf); + if (req->rq_cred != NULL) + put_rpccred(req->rq_cred); + if (req->rq_release_snd_buf) + req->rq_release_snd_buf(req);
task->tk_rqstp = NULL; if (likely(!bc_prealloc(req))) diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index 09953597d055..19a49d26b1e4 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -520,9 +520,8 @@ xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) return;
out_sleep: - set_bit(XPRT_CONGESTED, &xprt->state); - rpc_sleep_on(&xprt->backlog, task, NULL); task->tk_status = -EAGAIN; + xprt_add_backlog(xprt, task); }
/** @@ -537,10 +536,11 @@ xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst) struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt, rx_xprt);
- memset(rqst, 0, sizeof(*rqst)); - rpcrdma_buffer_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst)); - if (unlikely(!rpc_wake_up_next(&xprt->backlog))) - clear_bit(XPRT_CONGESTED, &xprt->state); + rpcrdma_reply_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst)); + if (!xprt_wake_up_backlog(xprt, rqst)) { + memset(rqst, 0, sizeof(*rqst)); + rpcrdma_buffer_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst)); + } }
static bool rpcrdma_check_regbuf(struct rpcrdma_xprt *r_xprt, diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index f3fffc74ab0f..0731b4756c49 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1184,6 +1184,20 @@ rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt) return mr; }
+/** + * rpcrdma_reply_put - Put reply buffers back into pool + * @buffers: buffer pool + * @req: object to return + * + */ +void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req) +{ + if (req->rl_reply) { + rpcrdma_rep_put(buffers, req->rl_reply); + req->rl_reply = NULL; + } +} + /** * rpcrdma_buffer_get - Get a request buffer * @buffers: Buffer pool from which to obtain a buffer @@ -1212,9 +1226,7 @@ rpcrdma_buffer_get(struct rpcrdma_buffer *buffers) */ void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req) { - if (req->rl_reply) - rpcrdma_rep_put(buffers, req->rl_reply); - req->rl_reply = NULL; + rpcrdma_reply_put(buffers, req);
spin_lock(&buffers->rb_lock); list_add(&req->rl_list, &buffers->rb_send_bufs); diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 28af11fbe643..ac13b93af9bd 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -481,6 +481,7 @@ struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req); void rpcrdma_recv_buffer_put(struct rpcrdma_rep *); +void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req);
bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags);