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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
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23 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
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26 * Copyright (c) 2011, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
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33 #define DEBUG_SUBSYSTEM S_RPC
35 #include <linux/delay.h>
36 #include <libcfs/linux/linux-hash.h>
37 #include <obd_support.h>
38 #include <obd_class.h>
39 #include <lustre_net.h>
41 #include "ptlrpc_internal.h"
43 static struct rhashtable conn_hash;
46 * struct lnet_process_id may contain unassigned bytes which might not
47 * be zero, so we cannot just hash and compare bytes.
50 static u32 lnet_process_id_hash(const void *data, u32 len, u32 seed)
52 const struct lnet_process_id *lpi = data;
54 seed = cfs_hash_32(seed ^ lpi->pid, 32);
55 seed ^= cfs_hash_64(lpi->nid, 32);
59 static int lnet_process_id_cmp(struct rhashtable_compare_arg *arg,
62 const struct lnet_process_id *lpi = arg->key;
63 const struct ptlrpc_connection *con = obj;
65 if (lpi->nid == con->c_peer.nid &&
66 lpi->pid == con->c_peer.pid)
71 static const struct rhashtable_params conn_hash_params = {
72 .key_len = 1, /* actually variable-length */
73 .key_offset = offsetof(struct ptlrpc_connection, c_peer),
74 .head_offset = offsetof(struct ptlrpc_connection, c_hash),
75 .hashfn = lnet_process_id_hash,
76 .obj_cmpfn = lnet_process_id_cmp,
79 struct ptlrpc_connection *
80 ptlrpc_connection_get(struct lnet_process_id peer, lnet_nid_t self,
81 struct obd_uuid *uuid)
83 struct ptlrpc_connection *conn, *conn2;
86 peer.nid = LNetPrimaryNID(peer.nid);
87 conn = rhashtable_lookup_fast(&conn_hash, &peer, conn_hash_params);
89 ptlrpc_connection_addref(conn);
99 atomic_set(&conn->c_refcount, 1);
101 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
104 * Add the newly created conn to the hash, on key collision we
105 * lost a racing addition and must destroy our newly allocated
106 * connection. The object which exists in the hash will be
107 * returned,otherwise NULL is returned on success.
110 conn2 = rhashtable_lookup_get_insert_fast(&conn_hash, &conn->c_hash,
113 /* insertion failed */
116 /* hash table could be resizing. */
117 if (PTR_ERR(conn2) == -ENOMEM ||
118 PTR_ERR(conn2) == -EBUSY) {
125 ptlrpc_connection_addref(conn);
129 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
130 conn, atomic_read(&conn->c_refcount),
131 libcfs_nid2str(conn->c_peer.nid));
135 struct ptlrpc_connection *
136 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
140 atomic_inc(&conn->c_refcount);
141 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
142 conn, atomic_read(&conn->c_refcount),
143 libcfs_nid2str(conn->c_peer.nid));
149 conn_exit(void *vconn, void *data)
151 struct ptlrpc_connection *conn = vconn;
154 * Nothing should be left. Connection user put it and
155 * connection also was deleted from table by this time
156 * so we should have 0 refs.
158 LASSERTF(atomic_read(&conn->c_refcount) == 0,
159 "Busy connection with %d refs\n",
160 atomic_read(&conn->c_refcount));
164 int ptlrpc_connection_init(void)
166 return rhashtable_init(&conn_hash, &conn_hash_params);
169 void ptlrpc_connection_fini(void)
171 rhashtable_free_and_destroy(&conn_hash, conn_exit, NULL);