[PATCH v1 13/18] xprtrdma: Remove rpcrdma_buffer::rb_mrlock

[Chuck Lever <chuck.lever@oracle.com>]

Clean up: Now that the free list is used sparingly, get rid of the
separate spin lock protecting it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/frwr_ops.c  |    4 ++--
 net/sunrpc/xprtrdma/verbs.c     |   21 ++++++++++-----------
 net/sunrpc/xprtrdma/xprt_rdma.h |    9 ++++-----
 3 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 0e740ba..368cdf3 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -106,10 +106,10 @@ void frwr_release_mr(struct rpcrdma_mr *mr)
 		mr->mr_dir = DMA_NONE;
 	}
 
-	spin_lock(&r_xprt->rx_buf.rb_mrlock);
+	spin_lock(&r_xprt->rx_buf.rb_lock);
 	list_del(&mr->mr_all);
 	r_xprt->rx_stats.mrs_recycled++;
-	spin_unlock(&r_xprt->rx_buf.rb_mrlock);
+	spin_unlock(&r_xprt->rx_buf.rb_lock);
 
 	frwr_release_mr(mr);
 }
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 1940ffc..15a77b3 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -960,10 +960,10 @@ struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt)
 
 		mr->mr_xprt = r_xprt;
 
-		spin_lock(&buf->rb_mrlock);
+		spin_lock(&buf->rb_lock);
 		list_add(&mr->mr_list, &buf->rb_mrs);
 		list_add(&mr->mr_all, &buf->rb_all_mrs);
-		spin_unlock(&buf->rb_mrlock);
+		spin_unlock(&buf->rb_lock);
 	}
 
 	r_xprt->rx_stats.mrs_allocated += count;
@@ -1076,7 +1076,6 @@ int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 
 	buf->rb_max_requests = r_xprt->rx_ep.rep_max_requests;
 	buf->rb_bc_srv_max_requests = 0;
-	spin_lock_init(&buf->rb_mrlock);
 	spin_lock_init(&buf->rb_lock);
 	INIT_LIST_HEAD(&buf->rb_mrs);
 	INIT_LIST_HEAD(&buf->rb_all_mrs);
@@ -1146,18 +1145,18 @@ void rpcrdma_req_destroy(struct rpcrdma_req *req)
 	unsigned int count;
 
 	count = 0;
-	spin_lock(&buf->rb_mrlock);
+	spin_lock(&buf->rb_lock);
 	while ((mr = list_first_entry_or_null(&buf->rb_all_mrs,
 					      struct rpcrdma_mr,
 					      mr_all)) != NULL) {
 		list_del(&mr->mr_all);
-		spin_unlock(&buf->rb_mrlock);
+		spin_unlock(&buf->rb_lock);
 
 		frwr_release_mr(mr);
 		count++;
-		spin_lock(&buf->rb_mrlock);
+		spin_lock(&buf->rb_lock);
 	}
-	spin_unlock(&buf->rb_mrlock);
+	spin_unlock(&buf->rb_lock);
 	r_xprt->rx_stats.mrs_allocated = 0;
 }
 
@@ -1210,9 +1209,9 @@ struct rpcrdma_mr *
 	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	struct rpcrdma_mr *mr;
 
-	spin_lock(&buf->rb_mrlock);
+	spin_lock(&buf->rb_lock);
 	mr = rpcrdma_mr_pop(&buf->rb_mrs);
-	spin_unlock(&buf->rb_mrlock);
+	spin_unlock(&buf->rb_lock);
 	return mr;
 }
 
@@ -1241,9 +1240,9 @@ static void rpcrdma_mr_free(struct rpcrdma_mr *mr)
 	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 
 	mr->mr_req = NULL;
-	spin_lock(&buf->rb_mrlock);
+	spin_lock(&buf->rb_lock);
 	rpcrdma_mr_push(mr, &buf->rb_mrs);
-	spin_unlock(&buf->rb_mrlock);
+	spin_unlock(&buf->rb_lock);
 }
 
 /**
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 6c9830a..b388bb4 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -365,19 +365,18 @@ struct rpcrdma_req {
  * One of these is associated with a transport instance
  */
 struct rpcrdma_buffer {
-	spinlock_t		rb_mrlock;	/* protect rb_mrs list */
+	spinlock_t		rb_lock;
+	struct list_head	rb_send_bufs;
+	struct list_head	rb_recv_bufs;
 	struct list_head	rb_mrs;
-	struct list_head	rb_all_mrs;
 
 	unsigned long		rb_sc_head;
 	unsigned long		rb_sc_tail;
 	unsigned long		rb_sc_last;
 	struct rpcrdma_sendctx	**rb_sc_ctxs;
 
-	spinlock_t		rb_lock;	/* protect buf lists */
-	struct list_head	rb_send_bufs;
-	struct list_head	rb_recv_bufs;
 	struct list_head	rb_allreqs;
+	struct list_head	rb_all_mrs;
 
 	u32			rb_max_requests;
 	u32			rb_credits;	/* most recent credit grant */