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* 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 struct cfs_hash_ops 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;
conn = kzalloc(sizeof(*conn), GFP_NOFS);
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) {
kfree(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 = 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));
kfree(conn);
}
static struct cfs_hash_ops 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,
};
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