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29 * This file is part of Lustre, http://www.lustre.org/
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33 #define DEBUG_SUBSYSTEM S_RPC
34 #include <obd_support.h>
35 #include <obd_class.h>
36 #include <lustre_net.h>
38 #include "ptlrpc_internal.h"
40 static struct cfs_hash *conn_hash;
41 static struct cfs_hash_ops conn_hash_ops;
43 struct ptlrpc_connection *
44 ptlrpc_connection_get(struct lnet_process_id peer, lnet_nid_t self,
45 struct obd_uuid *uuid)
47 struct ptlrpc_connection *conn, *conn2;
50 peer.nid = LNetPrimaryNID(peer.nid);
51 conn = cfs_hash_lookup(conn_hash, &peer);
61 INIT_HLIST_NODE(&conn->c_hash);
62 atomic_set(&conn->c_refcount, 1);
64 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
67 * Add the newly created conn to the hash, on key collision we
68 * lost a racing addition and must destroy our newly allocated
69 * connection. The object which exists in the hash will be
70 * returned and may be compared against out object.
72 /* In the function below, .hs_keycmp resolves to
74 /* coverity[overrun-buffer-val] */
75 conn2 = cfs_hash_findadd_unique(conn_hash, &peer, &conn->c_hash);
82 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
83 conn, atomic_read(&conn->c_refcount),
84 libcfs_nid2str(conn->c_peer.nid));
88 int ptlrpc_connection_put(struct ptlrpc_connection *conn)
96 LASSERT(atomic_read(&conn->c_refcount) > 1);
99 * We do not remove connection from hashtable and
100 * do not free it even if last caller released ref,
101 * as we want to have it cached for the case it is
104 * Deallocating it and later creating new connection
105 * again would be wastful. This way we also avoid
106 * expensive locking to protect things from get/put
107 * race when found cached connection is freed by
108 * ptlrpc_connection_put().
110 * It will be freed later in module unload time,
111 * when ptlrpc_connection_fini()->lh_exit->conn_exit()
114 if (atomic_dec_return(&conn->c_refcount) == 1)
117 CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n",
118 conn, atomic_read(&conn->c_refcount),
119 libcfs_nid2str(conn->c_peer.nid));
124 struct ptlrpc_connection *
125 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
129 atomic_inc(&conn->c_refcount);
130 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
131 conn, atomic_read(&conn->c_refcount),
132 libcfs_nid2str(conn->c_peer.nid));
137 int ptlrpc_connection_init(void)
141 conn_hash = cfs_hash_create("CONN_HASH",
144 HASH_CONN_BKT_BITS, 0,
147 &conn_hash_ops, CFS_HASH_DEFAULT);
154 void ptlrpc_connection_fini(void) {
156 cfs_hash_putref(conn_hash);
161 * Hash operations for net_peer<->connection
164 conn_hashfn(struct cfs_hash *hs, const void *key, unsigned mask)
166 return cfs_hash_djb2_hash(key, sizeof(struct lnet_process_id), mask);
170 conn_keycmp(const void *key, struct hlist_node *hnode)
172 struct ptlrpc_connection *conn;
173 const struct lnet_process_id *conn_key;
175 LASSERT(key != NULL);
176 conn_key = (struct lnet_process_id *)key;
177 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
179 return conn_key->nid == conn->c_peer.nid &&
180 conn_key->pid == conn->c_peer.pid;
184 conn_key(struct hlist_node *hnode)
186 struct ptlrpc_connection *conn;
187 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
188 return &conn->c_peer;
192 conn_object(struct hlist_node *hnode)
194 return hlist_entry(hnode, struct ptlrpc_connection, c_hash);
198 conn_get(struct cfs_hash *hs, struct hlist_node *hnode)
200 struct ptlrpc_connection *conn;
202 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
203 atomic_inc(&conn->c_refcount);
207 conn_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
209 struct ptlrpc_connection *conn;
211 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
212 atomic_dec(&conn->c_refcount);
216 conn_exit(struct cfs_hash *hs, struct hlist_node *hnode)
218 struct ptlrpc_connection *conn;
220 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
222 * Nothing should be left. Connection user put it and
223 * connection also was deleted from table by this time
224 * so we should have 0 refs.
226 LASSERTF(atomic_read(&conn->c_refcount) == 0,
227 "Busy connection with %d refs\n",
228 atomic_read(&conn->c_refcount));
232 static struct cfs_hash_ops conn_hash_ops = {
233 .hs_hash = conn_hashfn,
234 .hs_keycmp = conn_keycmp,
236 .hs_object = conn_object,
238 .hs_put_locked = conn_put_locked,
239 .hs_exit = conn_exit,