--- /dev/null
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
+#define DEBUG_SUBSYSTEM S_RPC
+#include "../include/obd_support.h"
+#include "../include/obd_class.h"
+#include "../include/lustre_net.h"
+
+#include "ptlrpc_internal.h"
+
+static struct cfs_hash *conn_hash;
+static cfs_hash_ops_t conn_hash_ops;
+
+struct ptlrpc_connection *
+ptlrpc_connection_get(lnet_process_id_t peer, lnet_nid_t self,
+ struct obd_uuid *uuid)
+{
+ struct ptlrpc_connection *conn, *conn2;
+
+ conn = cfs_hash_lookup(conn_hash, &peer);
+ if (conn)
+ goto out;
+
+ OBD_ALLOC_PTR(conn);
+ if (!conn)
+ return NULL;
+
+ conn->c_peer = peer;
+ conn->c_self = self;
+ INIT_HLIST_NODE(&conn->c_hash);
+ atomic_set(&conn->c_refcount, 1);
+ if (uuid)
+ obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
+
+ /*
+ * Add the newly created conn to the hash, on key collision we
+ * lost a racing addition and must destroy our newly allocated
+ * connection. The object which exists in the has will be
+ * returned and may be compared against out object.
+ */
+ /* In the function below, .hs_keycmp resolves to
+ * conn_keycmp() */
+ /* coverity[overrun-buffer-val] */
+ conn2 = cfs_hash_findadd_unique(conn_hash, &peer, &conn->c_hash);
+ if (conn != conn2) {
+ OBD_FREE_PTR(conn);
+ conn = conn2;
+ }
+out:
+ CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
+ conn, atomic_read(&conn->c_refcount),
+ libcfs_nid2str(conn->c_peer.nid));
+ return conn;
+}
+EXPORT_SYMBOL(ptlrpc_connection_get);
+
+int ptlrpc_connection_put(struct ptlrpc_connection *conn)
+{
+ int rc = 0;
+
+ if (!conn)
+ return rc;
+
+ LASSERT(atomic_read(&conn->c_refcount) > 1);
+
+ /*
+ * We do not remove connection from hashtable and
+ * do not free it even if last caller released ref,
+ * as we want to have it cached for the case it is
+ * needed again.
+ *
+ * Deallocating it and later creating new connection
+ * again would be wastful. This way we also avoid
+ * expensive locking to protect things from get/put
+ * race when found cached connection is freed by
+ * ptlrpc_connection_put().
+ *
+ * It will be freed later in module unload time,
+ * when ptlrpc_connection_fini()->lh_exit->conn_exit()
+ * path is called.
+ */
+ if (atomic_dec_return(&conn->c_refcount) == 1)
+ rc = 1;
+
+ CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n",
+ conn, atomic_read(&conn->c_refcount),
+ libcfs_nid2str(conn->c_peer.nid));
+
+ return rc;
+}
+EXPORT_SYMBOL(ptlrpc_connection_put);
+
+struct ptlrpc_connection *
+ptlrpc_connection_addref(struct ptlrpc_connection *conn)
+{
+ atomic_inc(&conn->c_refcount);
+ CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
+ conn, atomic_read(&conn->c_refcount),
+ libcfs_nid2str(conn->c_peer.nid));
+
+ return conn;
+}
+EXPORT_SYMBOL(ptlrpc_connection_addref);
+
+int ptlrpc_connection_init(void)
+{
+ conn_hash = cfs_hash_create("CONN_HASH",
+ HASH_CONN_CUR_BITS,
+ HASH_CONN_MAX_BITS,
+ HASH_CONN_BKT_BITS, 0,
+ CFS_HASH_MIN_THETA,
+ CFS_HASH_MAX_THETA,
+ &conn_hash_ops, CFS_HASH_DEFAULT);
+ if (!conn_hash)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL(ptlrpc_connection_init);
+
+void ptlrpc_connection_fini(void)
+{
+ cfs_hash_putref(conn_hash);
+}
+EXPORT_SYMBOL(ptlrpc_connection_fini);
+
+/*
+ * Hash operations for net_peer<->connection
+ */
+static unsigned
+conn_hashfn(struct cfs_hash *hs, const void *key, unsigned mask)
+{
+ return cfs_hash_djb2_hash(key, sizeof(lnet_process_id_t), mask);
+}
+
+static int
+conn_keycmp(const void *key, struct hlist_node *hnode)
+{
+ struct ptlrpc_connection *conn;
+ const lnet_process_id_t *conn_key;
+
+ LASSERT(key != NULL);
+ conn_key = (lnet_process_id_t *)key;
+ conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
+
+ return conn_key->nid == conn->c_peer.nid &&
+ conn_key->pid == conn->c_peer.pid;
+}
+
+static void *
+conn_key(struct hlist_node *hnode)
+{
+ struct ptlrpc_connection *conn;
+
+ conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
+ return &conn->c_peer;
+}
+
+static void *
+conn_object(struct hlist_node *hnode)
+{
+ return hlist_entry(hnode, struct ptlrpc_connection, c_hash);
+}
+
+static void
+conn_get(struct cfs_hash *hs, struct hlist_node *hnode)
+{
+ struct ptlrpc_connection *conn;
+
+ conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
+ atomic_inc(&conn->c_refcount);
+}
+
+static void
+conn_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
+{
+ struct ptlrpc_connection *conn;
+
+ conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
+ atomic_dec(&conn->c_refcount);
+}
+
+static void
+conn_exit(struct cfs_hash *hs, struct hlist_node *hnode)
+{
+ struct ptlrpc_connection *conn;
+
+ conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
+ /*
+ * Nothing should be left. Connection user put it and
+ * connection also was deleted from table by this time
+ * so we should have 0 refs.
+ */
+ LASSERTF(atomic_read(&conn->c_refcount) == 0,
+ "Busy connection with %d refs\n",
+ atomic_read(&conn->c_refcount));
+ OBD_FREE_PTR(conn);
+}
+
+static cfs_hash_ops_t conn_hash_ops = {
+ .hs_hash = conn_hashfn,
+ .hs_keycmp = conn_keycmp,
+ .hs_key = conn_key,
+ .hs_object = conn_object,
+ .hs_get = conn_get,
+ .hs_put_locked = conn_put_locked,
+ .hs_exit = conn_exit,
+};
Code Review / kvmfornfv.git / blobdiff