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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;
49 conn = cfs_hash_lookup(conn_hash, &peer);
53 conn = kzalloc(sizeof(*conn), GFP_NOFS);
59 INIT_HLIST_NODE(&conn->c_hash);
60 atomic_set(&conn->c_refcount, 1);
62 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
65 * Add the newly created conn to the hash, on key collision we
66 * lost a racing addition and must destroy our newly allocated
67 * connection. The object which exists in the has will be
68 * returned and may be compared against out object.
70 /* 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);
80 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
81 conn, atomic_read(&conn->c_refcount),
82 libcfs_nid2str(conn->c_peer.nid));
86 int ptlrpc_connection_put(struct ptlrpc_connection *conn)
93 LASSERT(atomic_read(&conn->c_refcount) > 1);
96 * We do not remove connection from hashtable and
97 * do not free it even if last caller released ref,
98 * as we want to have it cached for the case it is
101 * Deallocating it and later creating new connection
102 * again would be wastful. This way we also avoid
103 * expensive locking to protect things from get/put
104 * race when found cached connection is freed by
105 * ptlrpc_connection_put().
107 * It will be freed later in module unload time,
108 * when ptlrpc_connection_fini()->lh_exit->conn_exit()
111 if (atomic_dec_return(&conn->c_refcount) == 1)
114 CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n",
115 conn, atomic_read(&conn->c_refcount),
116 libcfs_nid2str(conn->c_peer.nid));
121 struct ptlrpc_connection *
122 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
124 atomic_inc(&conn->c_refcount);
125 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
126 conn, atomic_read(&conn->c_refcount),
127 libcfs_nid2str(conn->c_peer.nid));
132 int ptlrpc_connection_init(void)
134 conn_hash = cfs_hash_create("CONN_HASH",
137 HASH_CONN_BKT_BITS, 0,
140 &conn_hash_ops, CFS_HASH_DEFAULT);
147 void ptlrpc_connection_fini(void)
149 cfs_hash_putref(conn_hash);
153 * Hash operations for net_peer<->connection
156 conn_hashfn(struct cfs_hash *hs, const void *key, unsigned int mask)
158 return cfs_hash_djb2_hash(key, sizeof(struct lnet_process_id), mask);
162 conn_keycmp(const void *key, struct hlist_node *hnode)
164 struct ptlrpc_connection *conn;
165 const struct lnet_process_id *conn_key;
169 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
171 return conn_key->nid == conn->c_peer.nid &&
172 conn_key->pid == conn->c_peer.pid;
176 conn_key(struct hlist_node *hnode)
178 struct ptlrpc_connection *conn;
180 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
181 return &conn->c_peer;
185 conn_object(struct hlist_node *hnode)
187 return hlist_entry(hnode, struct ptlrpc_connection, c_hash);
191 conn_get(struct cfs_hash *hs, struct hlist_node *hnode)
193 struct ptlrpc_connection *conn;
195 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
196 atomic_inc(&conn->c_refcount);
200 conn_put_locked(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_dec(&conn->c_refcount);
209 conn_exit(struct cfs_hash *hs, struct hlist_node *hnode)
211 struct ptlrpc_connection *conn;
213 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
215 * Nothing should be left. Connection user put it and
216 * connection also was deleted from table by this time
217 * so we should have 0 refs.
219 LASSERTF(atomic_read(&conn->c_refcount) == 0,
220 "Busy connection with %d refs\n",
221 atomic_read(&conn->c_refcount));
225 static struct cfs_hash_ops conn_hash_ops = {
226 .hs_hash = conn_hashfn,
227 .hs_keycmp = conn_keycmp,
229 .hs_object = conn_object,
231 .hs_put_locked = conn_put_locked,
232 .hs_exit = conn_exit,