Return-Path: Received: from mail-qc0-f177.google.com ([209.85.216.177]:34760 "EHLO mail-qc0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178AbbEKSEH (ORCPT ); Mon, 11 May 2015 14:04:07 -0400 Subject: [PATCH v2 11/16] xprtrdma: Remove ->ro_reset From: Chuck Lever To: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Mon, 11 May 2015 14:04:01 -0400 Message-ID: <20150511180401.31263.9823.stgit@manet.1015granger.net> In-Reply-To: <20150511174401.31263.79596.stgit@manet.1015granger.net> References: <20150511174401.31263.79596.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: An RPC can exit at any time. When it does so, xprt_rdma_free() is called, and it calls ->op_unmap(). If ->ro_reset() is running due to a transport disconnect, the two methods can race while processing the same rpcrdma_mw. The results are unpredictable. Because of this, in previous patches I've altered ->ro_map() to handle MR reset. ->ro_reset() is no longer needed and can be removed. Signed-off-by: Chuck Lever Reviewed-by: Steve Wise Reviewed-by: Sagi Grimberg Reviewed-by: Devesh Sharma --- net/sunrpc/xprtrdma/fmr_ops.c | 23 --------------------- net/sunrpc/xprtrdma/frwr_ops.c | 39 ------------------------------------ net/sunrpc/xprtrdma/physical_ops.c | 6 ------ net/sunrpc/xprtrdma/verbs.c | 2 -- net/sunrpc/xprtrdma/xprt_rdma.h | 1 - 5 files changed, 71 deletions(-) diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c index 53fb649..5dd77da 100644 --- a/net/sunrpc/xprtrdma/fmr_ops.c +++ b/net/sunrpc/xprtrdma/fmr_ops.c @@ -197,28 +197,6 @@ out_err: return nsegs; } -/* After a disconnect, unmap all FMRs. - * - * This is invoked only in the transport connect worker in order - * to serialize with rpcrdma_register_fmr_external(). - */ -static void -fmr_op_reset(struct rpcrdma_xprt *r_xprt) -{ - struct rpcrdma_buffer *buf = &r_xprt->rx_buf; - struct rpcrdma_mw *r; - LIST_HEAD(list); - int rc; - - list_for_each_entry(r, &buf->rb_all, mw_all) - list_add(&r->r.fmr->list, &list); - - rc = ib_unmap_fmr(&list); - if (rc) - dprintk("RPC: %s: ib_unmap_fmr failed %i\n", - __func__, rc); -} - static void fmr_op_destroy(struct rpcrdma_buffer *buf) { @@ -242,7 +220,6 @@ const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = { .ro_open = fmr_op_open, .ro_maxpages = fmr_op_maxpages, .ro_init = fmr_op_init, - .ro_reset = fmr_op_reset, .ro_destroy = fmr_op_destroy, .ro_displayname = "fmr", }; diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c index 133edf6..8622792 100644 --- a/net/sunrpc/xprtrdma/frwr_ops.c +++ b/net/sunrpc/xprtrdma/frwr_ops.c @@ -430,44 +430,6 @@ out_err: return nsegs; } -/* After a disconnect, a flushed FAST_REG_MR can leave an FRMR in - * an unusable state. Find FRMRs in this state and dereg / reg - * each. FRMRs that are VALID and attached to an rpcrdma_req are - * also torn down. - * - * This gives all in-use FRMRs a fresh rkey and leaves them INVALID. - * - * This is invoked only in the transport connect worker in order - * to serialize with rpcrdma_register_frmr_external(). - */ -static void -frwr_op_reset(struct rpcrdma_xprt *r_xprt) -{ - struct rpcrdma_buffer *buf = &r_xprt->rx_buf; - struct ib_device *device = r_xprt->rx_ia.ri_device; - unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth; - struct ib_pd *pd = r_xprt->rx_ia.ri_pd; - struct rpcrdma_mw *r; - int rc; - - list_for_each_entry(r, &buf->rb_all, mw_all) { - if (r->r.frmr.fr_state == FRMR_IS_INVALID) - continue; - - __frwr_release(r); - rc = __frwr_init(r, pd, device, depth); - if (rc) { - dprintk("RPC: %s: mw %p left %s\n", - __func__, r, - (r->r.frmr.fr_state == FRMR_IS_STALE ? - "stale" : "valid")); - continue; - } - - r->r.frmr.fr_state = FRMR_IS_INVALID; - } -} - static void frwr_op_destroy(struct rpcrdma_buffer *buf) { @@ -490,7 +452,6 @@ const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = { .ro_open = frwr_op_open, .ro_maxpages = frwr_op_maxpages, .ro_init = frwr_op_init, - .ro_reset = frwr_op_reset, .ro_destroy = frwr_op_destroy, .ro_displayname = "frwr", }; diff --git a/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c index da149e8..41985d0 100644 --- a/net/sunrpc/xprtrdma/physical_ops.c +++ b/net/sunrpc/xprtrdma/physical_ops.c @@ -69,11 +69,6 @@ physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg) } static void -physical_op_reset(struct rpcrdma_xprt *r_xprt) -{ -} - -static void physical_op_destroy(struct rpcrdma_buffer *buf) { } @@ -84,7 +79,6 @@ const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = { .ro_open = physical_op_open, .ro_maxpages = physical_op_maxpages, .ro_init = physical_op_init, - .ro_reset = physical_op_reset, .ro_destroy = physical_op_destroy, .ro_displayname = "physical", }; diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index a891cf7..db9303a 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -891,8 +891,6 @@ retry: rpcrdma_flush_cqs(ep); xprt = container_of(ia, struct rpcrdma_xprt, rx_ia); - ia->ri_ops->ro_reset(xprt); - id = rpcrdma_create_id(xprt, ia, (struct sockaddr *)&xprt->rx_data.addr); if (IS_ERR(id)) { diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index c5862a4..f19376d 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -352,7 +352,6 @@ struct rpcrdma_memreg_ops { struct rpcrdma_create_data_internal *); size_t (*ro_maxpages)(struct rpcrdma_xprt *); int (*ro_init)(struct rpcrdma_xprt *); - void (*ro_reset)(struct rpcrdma_xprt *); void (*ro_destroy)(struct rpcrdma_buffer *); const char *ro_displayname; };