From: Chuck Lever <chuck.lever@oracle.com>
Date: Fri, 4 May 2018 15:34:59 -0400
Subject: SUNRPC: Add a ->free_slot transport callout
Patch-mainline: v4.18-rc1
Git-commit: a9cde23ab7cdf5e4e93432dffd0e734267f2b745
References: bsc#1103992 FATE#326009

Refactor: xprtrdma needs to have better control over when RPCs are
awoken from the backlog queue, so replace xprt_free_slot with a
transport op callout.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/sunrpc/xprt.h                |    4 ++++
 net/sunrpc/xprt.c                          |    5 +++--
 net/sunrpc/xprtrdma/svc_rdma_backchannel.c |    1 +
 net/sunrpc/xprtrdma/transport.c            |    1 +
 net/sunrpc/xprtsock.c                      |    4 ++++
 5 files changed, 13 insertions(+), 2 deletions(-)

--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -126,6 +126,8 @@ struct rpc_xprt_ops {
 	int		(*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 	void		(*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 	void		(*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
+	void		(*free_slot)(struct rpc_xprt *xprt,
+				     struct rpc_rqst *req);
 	void		(*rpcbind)(struct rpc_task *task);
 	void		(*set_port)(struct rpc_xprt *xprt, unsigned short port);
 	void		(*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
@@ -327,6 +329,8 @@ void			xprt_retry_reserve(struct rpc_tas
 int			xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 int			xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 void			xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
+void			xprt_free_slot(struct rpc_xprt *xprt,
+				       struct rpc_rqst *req);
 void			xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 bool			xprt_prepare_transmit(struct rpc_task *task);
 void			xprt_transmit(struct rpc_task *task);
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1164,7 +1164,7 @@ void xprt_lock_and_alloc_slot(struct rpc
 }
 EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot);
 
-static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
+void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
 {
 	spin_lock(&xprt->reserve_lock);
 	if (!xprt_dynamic_free_slot(xprt, req)) {
@@ -1174,6 +1174,7 @@ static void xprt_free_slot(struct rpc_xp
 	xprt_wake_up_backlog(xprt);
 	spin_unlock(&xprt->reserve_lock);
 }
+EXPORT_SYMBOL_GPL(xprt_free_slot);
 
 static void xprt_free_all_slots(struct rpc_xprt *xprt)
 {
@@ -1353,7 +1354,7 @@ void xprt_release(struct rpc_task *task)
 
 	dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
 	if (likely(!bc_prealloc(req)))
-		xprt_free_slot(xprt, req);
+		xprt->ops->free_slot(xprt, req);
 	else
 		xprt_free_bc_request(req);
 }
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -262,6 +262,7 @@ static const struct rpc_xprt_ops xprt_rd
 	.reserve_xprt		= xprt_reserve_xprt_cong,
 	.release_xprt		= xprt_release_xprt_cong,
 	.alloc_slot		= xprt_alloc_slot,
+	.free_slot		= xprt_free_slot,
 	.release_request	= xprt_release_rqst_cong,
 	.buf_alloc		= xprt_rdma_bc_allocate,
 	.buf_free		= xprt_rdma_bc_free,
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -786,6 +786,7 @@ static const struct rpc_xprt_ops xprt_rd
 	.reserve_xprt		= xprt_reserve_xprt_cong,
 	.release_xprt		= xprt_release_xprt_cong, /* sunrpc/xprt.c */
 	.alloc_slot		= xprt_alloc_slot,
+	.free_slot		= xprt_free_slot,
 	.release_request	= xprt_release_rqst_cong,       /* ditto */
 	.set_retrans_timeout	= xprt_set_retrans_timeout_def, /* ditto */
 	.timer			= xprt_rdma_timer,
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2744,6 +2744,7 @@ static const struct rpc_xprt_ops xs_loca
 	.reserve_xprt		= xprt_reserve_xprt,
 	.release_xprt		= xs_tcp_release_xprt,
 	.alloc_slot		= xprt_alloc_slot,
+	.free_slot		= xprt_free_slot,
 	.rpcbind		= xs_local_rpcbind,
 	.set_port		= xs_local_set_port,
 	.connect		= xs_local_connect,
@@ -2763,6 +2764,7 @@ static const struct rpc_xprt_ops xs_udp_
 	.reserve_xprt		= xprt_reserve_xprt_cong,
 	.release_xprt		= xprt_release_xprt_cong,
 	.alloc_slot		= xprt_alloc_slot,
+	.free_slot		= xprt_free_slot,
 	.rpcbind		= rpcb_getport_async,
 	.set_port		= xs_set_port,
 	.connect		= xs_connect,
@@ -2784,6 +2786,7 @@ static const struct rpc_xprt_ops xs_tcp_
 	.reserve_xprt		= xprt_reserve_xprt,
 	.release_xprt		= xs_tcp_release_xprt,
 	.alloc_slot		= xprt_lock_and_alloc_slot,
+	.free_slot		= xprt_free_slot,
 	.rpcbind		= rpcb_getport_async,
 	.set_port		= xs_set_port,
 	.connect		= xs_connect,
@@ -2815,6 +2818,7 @@ static const struct rpc_xprt_ops bc_tcp_
 	.reserve_xprt		= xprt_reserve_xprt,
 	.release_xprt		= xprt_release_xprt,
 	.alloc_slot		= xprt_alloc_slot,
+	.free_slot		= xprt_free_slot,
 	.buf_alloc		= bc_malloc,
 	.buf_free		= bc_free,
 	.send_request		= bc_send_request,