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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(lnet_process_id_t peer, lnet_nid_t self,
45 struct obd_uuid *uuid)
47 struct ptlrpc_connection *conn, *conn2;
50 conn = cfs_hash_lookup(conn_hash, &peer);
60 INIT_HLIST_NODE(&conn->c_hash);
61 atomic_set(&conn->c_refcount, 1);
63 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
66 * Add the newly created conn to the hash, on key collision we
67 * lost a racing addition and must destroy our newly allocated
68 * connection. The object which exists in the has will be
69 * returned and may be compared against out object.
71 /* In the function below, .hs_keycmp resolves to
73 /* coverity[overrun-buffer-val] */
74 conn2 = cfs_hash_findadd_unique(conn_hash, &peer, &conn->c_hash);
81 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
82 conn, atomic_read(&conn->c_refcount),
83 libcfs_nid2str(conn->c_peer.nid));
87 int ptlrpc_connection_put(struct ptlrpc_connection *conn)
95 LASSERT(atomic_read(&conn->c_refcount) > 1);
98 * We do not remove connection from hashtable and
99 * do not free it even if last caller released ref,
100 * as we want to have it cached for the case it is
103 * Deallocating it and later creating new connection
104 * again would be wastful. This way we also avoid
105 * expensive locking to protect things from get/put
106 * race when found cached connection is freed by
107 * ptlrpc_connection_put().
109 * It will be freed later in module unload time,
110 * when ptlrpc_connection_fini()->lh_exit->conn_exit()
113 if (atomic_dec_return(&conn->c_refcount) == 1)
116 CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n",
117 conn, atomic_read(&conn->c_refcount),
118 libcfs_nid2str(conn->c_peer.nid));
123 struct ptlrpc_connection *
124 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
128 atomic_inc(&conn->c_refcount);
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));
136 int ptlrpc_connection_init(void)
140 conn_hash = cfs_hash_create("CONN_HASH",
143 HASH_CONN_BKT_BITS, 0,
146 &conn_hash_ops, CFS_HASH_DEFAULT);
153 void ptlrpc_connection_fini(void) {
155 cfs_hash_putref(conn_hash);
160 * Hash operations for net_peer<->connection
163 conn_hashfn(struct cfs_hash *hs, const void *key, unsigned mask)
165 return cfs_hash_djb2_hash(key, sizeof(lnet_process_id_t), mask);
169 conn_keycmp(const void *key, struct hlist_node *hnode)
171 struct ptlrpc_connection *conn;
172 const lnet_process_id_t *conn_key;
174 LASSERT(key != NULL);
175 conn_key = (lnet_process_id_t *)key;
176 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
178 return conn_key->nid == conn->c_peer.nid &&
179 conn_key->pid == conn->c_peer.pid;
183 conn_key(struct hlist_node *hnode)
185 struct ptlrpc_connection *conn;
186 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
187 return &conn->c_peer;
191 conn_object(struct hlist_node *hnode)
193 return hlist_entry(hnode, struct ptlrpc_connection, c_hash);
197 conn_get(struct cfs_hash *hs, struct hlist_node *hnode)
199 struct ptlrpc_connection *conn;
201 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
202 atomic_inc(&conn->c_refcount);
206 conn_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
208 struct ptlrpc_connection *conn;
210 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
211 atomic_dec(&conn->c_refcount);
215 conn_exit(struct cfs_hash *hs, struct hlist_node *hnode)
217 struct ptlrpc_connection *conn;
219 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
221 * Nothing should be left. Connection user put it and
222 * connection also was deleted from table by this time
223 * so we should have 0 refs.
225 LASSERTF(atomic_read(&conn->c_refcount) == 0,
226 "Busy connection with %d refs\n",
227 atomic_read(&conn->c_refcount));
231 static struct cfs_hash_ops conn_hash_ops = {
232 .hs_hash = conn_hashfn,
233 .hs_keycmp = conn_keycmp,
235 .hs_object = conn_object,
237 .hs_put_locked = conn_put_locked,
238 .hs_exit = conn_exit,