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37 #define DEBUG_SUBSYSTEM S_RPC
38 #include "../include/obd_support.h"
39 #include "../include/obd_class.h"
40 #include "../include/lustre_net.h"
42 #include "ptlrpc_internal.h"
44 static struct cfs_hash *conn_hash;
45 static struct cfs_hash_ops conn_hash_ops;
47 struct ptlrpc_connection *
48 ptlrpc_connection_get(lnet_process_id_t peer, lnet_nid_t self,
49 struct obd_uuid *uuid)
51 struct ptlrpc_connection *conn, *conn2;
53 conn = cfs_hash_lookup(conn_hash, &peer);
57 conn = kzalloc(sizeof(*conn), GFP_NOFS);
63 INIT_HLIST_NODE(&conn->c_hash);
64 atomic_set(&conn->c_refcount, 1);
66 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
69 * Add the newly created conn to the hash, on key collision we
70 * lost a racing addition and must destroy our newly allocated
71 * connection. The object which exists in the has will be
72 * returned and may be compared against out object.
74 /* In the function below, .hs_keycmp resolves to
77 /* coverity[overrun-buffer-val] */
78 conn2 = cfs_hash_findadd_unique(conn_hash, &peer, &conn->c_hash);
84 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
85 conn, atomic_read(&conn->c_refcount),
86 libcfs_nid2str(conn->c_peer.nid));
89 EXPORT_SYMBOL(ptlrpc_connection_get);
91 int ptlrpc_connection_put(struct ptlrpc_connection *conn)
98 LASSERT(atomic_read(&conn->c_refcount) > 1);
101 * We do not remove connection from hashtable and
102 * do not free it even if last caller released ref,
103 * as we want to have it cached for the case it is
106 * Deallocating it and later creating new connection
107 * again would be wastful. This way we also avoid
108 * expensive locking to protect things from get/put
109 * race when found cached connection is freed by
110 * ptlrpc_connection_put().
112 * It will be freed later in module unload time,
113 * when ptlrpc_connection_fini()->lh_exit->conn_exit()
116 if (atomic_dec_return(&conn->c_refcount) == 1)
119 CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n",
120 conn, atomic_read(&conn->c_refcount),
121 libcfs_nid2str(conn->c_peer.nid));
125 EXPORT_SYMBOL(ptlrpc_connection_put);
127 struct ptlrpc_connection *
128 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
130 atomic_inc(&conn->c_refcount);
131 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
132 conn, atomic_read(&conn->c_refcount),
133 libcfs_nid2str(conn->c_peer.nid));
137 EXPORT_SYMBOL(ptlrpc_connection_addref);
139 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);
153 EXPORT_SYMBOL(ptlrpc_connection_init);
155 void ptlrpc_connection_fini(void)
157 cfs_hash_putref(conn_hash);
159 EXPORT_SYMBOL(ptlrpc_connection_fini);
162 * Hash operations for net_peer<->connection
165 conn_hashfn(struct cfs_hash *hs, const void *key, unsigned mask)
167 return cfs_hash_djb2_hash(key, sizeof(lnet_process_id_t), mask);
171 conn_keycmp(const void *key, struct hlist_node *hnode)
173 struct ptlrpc_connection *conn;
174 const lnet_process_id_t *conn_key;
178 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
180 return conn_key->nid == conn->c_peer.nid &&
181 conn_key->pid == conn->c_peer.pid;
185 conn_key(struct hlist_node *hnode)
187 struct ptlrpc_connection *conn;
189 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
190 return &conn->c_peer;
194 conn_object(struct hlist_node *hnode)
196 return hlist_entry(hnode, struct ptlrpc_connection, c_hash);
200 conn_get(struct cfs_hash *hs, struct hlist_node *hnode)
202 struct ptlrpc_connection *conn;
204 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
205 atomic_inc(&conn->c_refcount);
209 conn_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
211 struct ptlrpc_connection *conn;
213 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
214 atomic_dec(&conn->c_refcount);
218 conn_exit(struct cfs_hash *hs, struct hlist_node *hnode)
220 struct ptlrpc_connection *conn;
222 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
224 * Nothing should be left. Connection user put it and
225 * connection also was deleted from table by this time
226 * so we should have 0 refs.
228 LASSERTF(atomic_read(&conn->c_refcount) == 0,
229 "Busy connection with %d refs\n",
230 atomic_read(&conn->c_refcount));
234 static struct cfs_hash_ops conn_hash_ops = {
235 .hs_hash = conn_hashfn,
236 .hs_keycmp = conn_keycmp,
238 .hs_object = conn_object,
240 .hs_put_locked = conn_put_locked,
241 .hs_exit = conn_exit,