/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * * 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, Whamcloud, Inc. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. */ #define DEBUG_SUBSYSTEM S_RPC #ifdef __KERNEL__ #include #include #include #else #include #endif #include "ptlrpc_internal.h" static cfs_hash_t *conn_hash = NULL; 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; ENTRY; conn = cfs_hash_lookup(conn_hash, &peer); if (conn) GOTO(out, conn); OBD_ALLOC_PTR(conn); if (!conn) RETURN(NULL); conn->c_peer = peer; conn->c_self = self; CFS_INIT_HLIST_NODE(&conn->c_hash); cfs_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. */ conn2 = cfs_hash_findadd_unique(conn_hash, &peer, &conn->c_hash); if (conn != conn2) { OBD_FREE_PTR(conn); conn = conn2; } EXIT; out: CDEBUG(D_INFO, "conn=%p refcount %d to %s\n", conn, cfs_atomic_read(&conn->c_refcount), libcfs_nid2str(conn->c_peer.nid)); return conn; } int ptlrpc_connection_put(struct ptlrpc_connection *conn) { int rc = 0; ENTRY; if (!conn) RETURN(rc); LASSERT(cfs_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 (cfs_atomic_dec_return(&conn->c_refcount) == 1) rc = 1; CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n", conn, cfs_atomic_read(&conn->c_refcount), libcfs_nid2str(conn->c_peer.nid)); RETURN(rc); } struct ptlrpc_connection * ptlrpc_connection_addref(struct ptlrpc_connection *conn) { ENTRY; cfs_atomic_inc(&conn->c_refcount); CDEBUG(D_INFO, "conn=%p refcount %d to %s\n", conn, cfs_atomic_read(&conn->c_refcount), libcfs_nid2str(conn->c_peer.nid)); RETURN(conn); } int ptlrpc_connection_init(void) { ENTRY; 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); } void ptlrpc_connection_fini(void) { ENTRY; cfs_hash_putref(conn_hash); EXIT; } /* * Hash operations for net_peer<->connection */ static unsigned conn_hashfn(cfs_hash_t *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, cfs_hlist_node_t *hnode) { struct ptlrpc_connection *conn; const lnet_process_id_t *conn_key; LASSERT(key != NULL); conn_key = (lnet_process_id_t*)key; conn = cfs_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(cfs_hlist_node_t *hnode) { struct ptlrpc_connection *conn; conn = cfs_hlist_entry(hnode, struct ptlrpc_connection, c_hash); return &conn->c_peer; } static void * conn_object(cfs_hlist_node_t *hnode) { return cfs_hlist_entry(hnode, struct ptlrpc_connection, c_hash); } static void conn_get(cfs_hash_t *hs, cfs_hlist_node_t *hnode) { struct ptlrpc_connection *conn; conn = cfs_hlist_entry(hnode, struct ptlrpc_connection, c_hash); cfs_atomic_inc(&conn->c_refcount); } static void conn_put_locked(cfs_hash_t *hs, cfs_hlist_node_t *hnode) { struct ptlrpc_connection *conn; conn = cfs_hlist_entry(hnode, struct ptlrpc_connection, c_hash); cfs_atomic_dec(&conn->c_refcount); } static void conn_exit(cfs_hash_t *hs, cfs_hlist_node_t *hnode) { struct ptlrpc_connection *conn; conn = cfs_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(cfs_atomic_read(&conn->c_refcount) == 0, "Busy connection with %d refs\n", cfs_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, };