From 81fa3275f95ac357188fe3ca81b8e7c75360c88d Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 7 Feb 2017 11:59:04 -0500 Subject: [PATCH] svcrdma: Poll CQs in "workqueue" mode svcrdma calls svc_xprt_put() in its completion handlers, which currently run in IRQ context. However, svc_xprt_put() is meant to be invoked in process context, not in IRQ context. After the last transport reference is gone, it directly calls a transport release function that expects to run in process context. Change the CQ polling modes to IB_POLL_WORKQUEUE so that svcrdma invokes svc_xprt_put() only in process context. As an added benefit, bottom half-disabled spin locking can be eliminated from I/O paths. Signed-off-by: Chuck Lever Reviewed-by: Christoph Hellwig Signed-off-by: J. Bruce Fields --- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 6 +++--- net/sunrpc/xprtrdma/svc_rdma_transport.c | 26 +++++++++++++------------- 2 files changed, 16 insertions(+), 16 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index b9ccd73..f7b2daf 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -606,12 +606,12 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) dprintk("svcrdma: rqstp=%p\n", rqstp); - spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); + spin_lock(&rdma_xprt->sc_rq_dto_lock); if (!list_empty(&rdma_xprt->sc_read_complete_q)) { ctxt = list_first_entry(&rdma_xprt->sc_read_complete_q, struct svc_rdma_op_ctxt, list); list_del(&ctxt->list); - spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); + spin_unlock(&rdma_xprt->sc_rq_dto_lock); rdma_read_complete(rqstp, ctxt); goto complete; } else if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { @@ -623,7 +623,7 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) clear_bit(XPT_DATA, &xprt->xpt_flags); ctxt = NULL; } - spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); + spin_unlock(&rdma_xprt->sc_rq_dto_lock); if (!ctxt) { /* This is the EAGAIN path. The svc_recv routine will * return -EAGAIN, the nfsd thread will go to call into diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 87b8b5a..ab2fd53 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -188,7 +188,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) { struct svc_rdma_op_ctxt *ctxt = NULL; - spin_lock_bh(&xprt->sc_ctxt_lock); + spin_lock(&xprt->sc_ctxt_lock); xprt->sc_ctxt_used++; if (list_empty(&xprt->sc_ctxts)) goto out_empty; @@ -196,7 +196,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) ctxt = list_first_entry(&xprt->sc_ctxts, struct svc_rdma_op_ctxt, list); list_del(&ctxt->list); - spin_unlock_bh(&xprt->sc_ctxt_lock); + spin_unlock(&xprt->sc_ctxt_lock); out: ctxt->count = 0; @@ -208,15 +208,15 @@ out_empty: /* Either pre-allocation missed the mark, or send * queue accounting is broken. */ - spin_unlock_bh(&xprt->sc_ctxt_lock); + spin_unlock(&xprt->sc_ctxt_lock); ctxt = alloc_ctxt(xprt, GFP_NOIO); if (ctxt) goto out; - spin_lock_bh(&xprt->sc_ctxt_lock); + spin_lock(&xprt->sc_ctxt_lock); xprt->sc_ctxt_used--; - spin_unlock_bh(&xprt->sc_ctxt_lock); + spin_unlock(&xprt->sc_ctxt_lock); WARN_ONCE(1, "svcrdma: empty RDMA ctxt list?\n"); return NULL; } @@ -253,10 +253,10 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages) for (i = 0; i < ctxt->count; i++) put_page(ctxt->pages[i]); - spin_lock_bh(&xprt->sc_ctxt_lock); + spin_lock(&xprt->sc_ctxt_lock); xprt->sc_ctxt_used--; list_add(&ctxt->list, &xprt->sc_ctxts); - spin_unlock_bh(&xprt->sc_ctxt_lock); + spin_unlock(&xprt->sc_ctxt_lock); } static void svc_rdma_destroy_ctxts(struct svcxprt_rdma *xprt) @@ -921,14 +921,14 @@ struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma) { struct svc_rdma_fastreg_mr *frmr = NULL; - spin_lock_bh(&rdma->sc_frmr_q_lock); + spin_lock(&rdma->sc_frmr_q_lock); if (!list_empty(&rdma->sc_frmr_q)) { frmr = list_entry(rdma->sc_frmr_q.next, struct svc_rdma_fastreg_mr, frmr_list); list_del_init(&frmr->frmr_list); frmr->sg_nents = 0; } - spin_unlock_bh(&rdma->sc_frmr_q_lock); + spin_unlock(&rdma->sc_frmr_q_lock); if (frmr) return frmr; @@ -941,10 +941,10 @@ void svc_rdma_put_frmr(struct svcxprt_rdma *rdma, if (frmr) { ib_dma_unmap_sg(rdma->sc_cm_id->device, frmr->sg, frmr->sg_nents, frmr->direction); - spin_lock_bh(&rdma->sc_frmr_q_lock); + spin_lock(&rdma->sc_frmr_q_lock); WARN_ON_ONCE(!list_empty(&frmr->frmr_list)); list_add(&frmr->frmr_list, &rdma->sc_frmr_q); - spin_unlock_bh(&rdma->sc_frmr_q_lock); + spin_unlock(&rdma->sc_frmr_q_lock); } } @@ -1026,13 +1026,13 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) goto errout; } newxprt->sc_sq_cq = ib_alloc_cq(dev, newxprt, newxprt->sc_sq_depth, - 0, IB_POLL_SOFTIRQ); + 0, IB_POLL_WORKQUEUE); if (IS_ERR(newxprt->sc_sq_cq)) { dprintk("svcrdma: error creating SQ CQ for connect request\n"); goto errout; } newxprt->sc_rq_cq = ib_alloc_cq(dev, newxprt, newxprt->sc_rq_depth, - 0, IB_POLL_SOFTIRQ); + 0, IB_POLL_WORKQUEUE); if (IS_ERR(newxprt->sc_rq_cq)) { dprintk("svcrdma: error creating RQ CQ for connect request\n"); goto errout; -- 2.7.4