svcrdma: Add a type for keeping NFS RPC mapping

Create a new data structure to hold the remote client address space
to local server address space mapping.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>

2 files changed, 45 insertions, 0 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
index 88c0ca2..171f205 100644
--- a/net/sunrpc/xprtrdma/svc_rdma.c
+++ b/net/sunrpc/xprtrdma/svc_rdma.c
@@ -69,6 +69,9 @@ atomic_t rdma_stat_rq_prod;
 atomic_t rdma_stat_sq_poll;
 atomic_t rdma_stat_sq_prod;
 
+/* Temporary NFS request map cache */
+struct kmem_cache *svc_rdma_map_cachep;
+
 /*
  * This function implements reading and resetting an atomic_t stat
  * variable through read/write to a proc file. Any write to the file
@@ -241,6 +244,7 @@ void svc_rdma_cleanup(void)
 		svcrdma_table_header = NULL;
 	}
 	svc_unreg_xprt_class(&svc_rdma_class);
+	kmem_cache_destroy(svc_rdma_map_cachep);
 }
 
 int svc_rdma_init(void)
@@ -255,9 +259,24 @@ int svc_rdma_init(void)
 		svcrdma_table_header =
 			register_sysctl_table(svcrdma_root_table);
 
+	/* Create the temporary map cache */
+	svc_rdma_map_cachep = kmem_cache_create("svc_rdma_map_cache",
+						sizeof(struct svc_rdma_req_map),
+						0,
+						SLAB_HWCACHE_ALIGN,
+						NULL);
+	if (!svc_rdma_map_cachep) {
+		printk(KERN_INFO "Could not allocate map cache.\n");
+		goto err;
+	}
+
 	/* Register RDMA with the SVC transport switch */
 	svc_reg_xprt_class(&svc_rdma_class);
 	return 0;
+
+ err:
+	unregister_sysctl_table(svcrdma_table_header);
+	return -ENOMEM;
 }
 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
 MODULE_DESCRIPTION("SVC RDMA Transport");
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index e132509..ae90758 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -173,6 +173,32 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
 	atomic_dec(&xprt->sc_ctxt_used);
 }
 
+/* Temporary NFS request map cache. Created in svc_rdma.c  */
+extern struct kmem_cache *svc_rdma_map_cachep;
+
+/*
+ * Temporary NFS req mappings are shared across all transport
+ * instances. These are short lived and should be bounded by the number
+ * of concurrent server threads * depth of the SQ.
+ */
+struct svc_rdma_req_map *svc_rdma_get_req_map(void)
+{
+	struct svc_rdma_req_map *map;
+	while (1) {
+		map = kmem_cache_alloc(svc_rdma_map_cachep, GFP_KERNEL);
+		if (map)
+			break;
+		schedule_timeout_uninterruptible(msecs_to_jiffies(500));
+	}
+	map->count = 0;
+	return map;
+}
+
+void svc_rdma_put_req_map(struct svc_rdma_req_map *map)
+{
+	kmem_cache_free(svc_rdma_map_cachep, map);
+}
+
 /* ib_cq event handler */
 static void cq_event_handler(struct ib_event *event, void *context)
 {