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13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
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17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
32 #define DEBUG_SUBSYSTEM S_RPC
34 #include <linux/delay.h>
35 #include <libcfs/linux/linux-hash.h>
36 #include <obd_support.h>
37 #include <obd_class.h>
38 #include <lustre_net.h>
40 #include "ptlrpc_internal.h"
42 static struct rhashtable conn_hash;
45 * struct lnet_process_id may contain unassigned bytes which might not
46 * be zero, so we cannot just hash and compare bytes.
49 static u32 lnet_process_id_hash(const void *data, u32 len, u32 seed)
51 const struct lnet_processid *lpi = data;
53 seed = cfs_hash_32(seed ^ lpi->pid, 32);
54 seed = cfs_hash_32(nidhash(&lpi->nid) ^ seed, 32);
58 static int lnet_process_id_cmp(struct rhashtable_compare_arg *arg,
61 const struct lnet_processid *lpi = arg->key;
62 const struct ptlrpc_connection *con = obj;
64 if (nid_same(&lpi->nid, &con->c_peer.nid) &&
65 lpi->pid == con->c_peer.pid)
70 static const struct rhashtable_params conn_hash_params = {
71 .key_len = 1, /* actually variable-length */
72 .key_offset = offsetof(struct ptlrpc_connection, c_peer),
73 .head_offset = offsetof(struct ptlrpc_connection, c_hash),
74 .hashfn = lnet_process_id_hash,
75 .obj_cmpfn = lnet_process_id_cmp,
78 struct ptlrpc_connection *
79 ptlrpc_connection_get(struct lnet_process_id peer4, lnet_nid_t self,
80 struct obd_uuid *uuid)
82 struct ptlrpc_connection *conn, *conn2;
83 struct lnet_processid peer;
86 lnet_pid4_to_pid(peer4, &peer);
87 LNetPrimaryNID(&peer.nid);
88 conn = rhashtable_lookup_fast(&conn_hash, &peer, conn_hash_params);
90 ptlrpc_connection_addref(conn);
99 lnet_nid4_to_nid(self, &conn->c_self);
100 atomic_set(&conn->c_refcount, 1);
102 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
105 * Add the newly created conn to the hash, on key collision we
106 * lost a racing addition and must destroy our newly allocated
107 * connection. The object which exists in the hash will be
108 * returned,otherwise NULL is returned on success.
111 conn2 = rhashtable_lookup_get_insert_fast(&conn_hash, &conn->c_hash,
114 /* insertion failed */
116 /* hash table could be resizing. */
117 if (PTR_ERR(conn2) == -ENOMEM ||
118 PTR_ERR(conn2) == -EBUSY) {
127 ptlrpc_connection_addref(conn);
131 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
132 conn, atomic_read(&conn->c_refcount),
133 libcfs_nidstr(&conn->c_peer.nid));
137 struct ptlrpc_connection *
138 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
142 atomic_inc(&conn->c_refcount);
143 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
144 conn, atomic_read(&conn->c_refcount),
145 libcfs_nidstr(&conn->c_peer.nid));
151 conn_exit(void *vconn, void *data)
153 struct ptlrpc_connection *conn = vconn;
156 * Nothing should be left. Connection user put it and
157 * connection also was deleted from table by this time
158 * so we should have 0 refs.
160 LASSERTF(atomic_read(&conn->c_refcount) == 0,
161 "Busy connection with %d refs\n",
162 atomic_read(&conn->c_refcount));
166 int ptlrpc_connection_init(void)
168 return rhashtable_init(&conn_hash, &conn_hash_params);
171 void ptlrpc_connection_fini(void)
173 rhashtable_free_and_destroy(&conn_hash, conn_exit, NULL);