1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
30 * Use is subject to license terms.
32 * Copyright (c) 2011, Whamcloud, Inc.
35 * This file is part of Lustre, http://www.lustre.org/
36 * Lustre is a trademark of Sun Microsystems, Inc.
38 * lustre/obdclass/lustre_handles.c
40 * Author: Phil Schwan <phil@clusterfs.com>
43 #define DEBUG_SUBSYSTEM S_CLASS
45 # include <liblustre.h>
48 #include <obd_support.h>
49 #include <lustre_handles.h>
50 #include <lustre_lib.h>
52 #if !defined(HAVE_RCU) || !defined(__KERNEL__)
53 # define list_add_rcu cfs_list_add
54 # define list_del_rcu cfs_list_del
55 # define list_for_each_rcu cfs_list_for_each
56 # define list_for_each_safe_rcu cfs_list_for_each_safe
57 # define list_for_each_entry_rcu cfs_list_for_each_entry
58 # define rcu_read_lock() cfs_spin_lock(&bucket->lock)
59 # define rcu_read_unlock() cfs_spin_unlock(&bucket->lock)
60 #endif /* ifndef HAVE_RCU */
62 static __u64 handle_base;
64 static cfs_spinlock_t handle_base_lock;
66 static struct handle_bucket {
72 /* For unknown reason, UML uses kmalloc rather than vmalloc to allocate
73 * memory(OBD_VMALLOC). Therefore, we have to redefine the
74 * HANDLE_HASH_SIZE to make the hash heads don't exceed 128K.
76 #define HANDLE_HASH_SIZE 4096
78 #define HANDLE_HASH_SIZE (1 << 16)
79 #endif /* ifdef __arch_um__ */
81 #define HANDLE_HASH_MASK (HANDLE_HASH_SIZE - 1)
84 * Generate a unique 64bit cookie (hash) for a handle and insert it into
85 * global (per-node) hash-table.
87 void class_handle_hash(struct portals_handle *h, portals_handle_addref_cb cb)
89 struct handle_bucket *bucket;
93 LASSERT(cfs_list_empty(&h->h_link));
96 * This is fast, but simplistic cookie generation algorithm, it will
97 * need a re-do at some point in the future for security.
99 cfs_spin_lock(&handle_base_lock);
100 handle_base += HANDLE_INCR;
102 h->h_cookie = handle_base;
103 if (unlikely(handle_base == 0)) {
105 * Cookie of zero is "dangerous", because in many places it's
106 * assumed that 0 means "unassigned" handle, not bound to any
109 CWARN("The universe has been exhausted: cookie wrap-around.\n");
110 handle_base += HANDLE_INCR;
112 cfs_spin_unlock(&handle_base_lock);
115 cfs_spin_lock_init(&h->h_lock);
117 bucket = &handle_hash[h->h_cookie & HANDLE_HASH_MASK];
118 cfs_spin_lock(&bucket->lock);
119 list_add_rcu(&h->h_link, &bucket->head);
121 cfs_spin_unlock(&bucket->lock);
123 CDEBUG(D_INFO, "added object %p with handle "LPX64" to hash\n",
128 static void class_handle_unhash_nolock(struct portals_handle *h)
130 if (cfs_list_empty(&h->h_link)) {
131 CERROR("removing an already-removed handle ("LPX64")\n",
136 CDEBUG(D_INFO, "removing object %p with handle "LPX64" from hash\n",
139 cfs_spin_lock(&h->h_lock);
141 cfs_spin_unlock(&h->h_lock);
145 cfs_spin_unlock(&h->h_lock);
146 list_del_rcu(&h->h_link);
149 void class_handle_unhash(struct portals_handle *h)
151 struct handle_bucket *bucket;
152 bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
154 cfs_spin_lock(&bucket->lock);
155 class_handle_unhash_nolock(h);
156 cfs_spin_unlock(&bucket->lock);
159 void class_handle_hash_back(struct portals_handle *h)
161 struct handle_bucket *bucket;
164 bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
166 cfs_spin_lock(&bucket->lock);
167 list_add_rcu(&h->h_link, &bucket->head);
169 cfs_spin_unlock(&bucket->lock);
174 void *class_handle2object(__u64 cookie)
176 struct handle_bucket *bucket;
177 struct portals_handle *h;
181 LASSERT(handle_hash != NULL);
183 /* Be careful when you want to change this code. See the
184 * rcu_read_lock() definition on top this file. - jxiong */
185 bucket = handle_hash + (cookie & HANDLE_HASH_MASK);
188 list_for_each_entry_rcu(h, &bucket->head, h_link) {
189 if (h->h_cookie != cookie)
192 cfs_spin_lock(&h->h_lock);
193 if (likely(h->h_in != 0)) {
197 cfs_spin_unlock(&h->h_lock);
205 void class_handle_free_cb(cfs_rcu_head_t *rcu)
207 struct portals_handle *h = RCU2HANDLE(rcu);
209 h->h_free_cb(h->h_ptr, h->h_size);
211 void *ptr = h->h_ptr;
212 unsigned int size = h->h_size;
217 int class_handle_init(void)
219 struct handle_bucket *bucket;
223 LASSERT(handle_hash == NULL);
225 OBD_ALLOC_LARGE(handle_hash, sizeof(*bucket) * HANDLE_HASH_SIZE);
226 if (handle_hash == NULL)
229 cfs_spin_lock_init(&handle_base_lock);
230 for (bucket = handle_hash + HANDLE_HASH_SIZE - 1; bucket >= handle_hash;
232 CFS_INIT_LIST_HEAD(&bucket->head);
233 cfs_spin_lock_init(&bucket->lock);
236 /** bug 21430: add randomness to the initial base */
237 cfs_get_random_bytes(seed, sizeof(seed));
238 cfs_gettimeofday(&tv);
239 cfs_srand(tv.tv_sec ^ seed[0], tv.tv_usec ^ seed[1]);
241 cfs_get_random_bytes(&handle_base, sizeof(handle_base));
242 LASSERT(handle_base != 0ULL);
247 static int cleanup_all_handles(void)
252 for (rc = i = 0; i < HANDLE_HASH_SIZE; i++) {
253 struct portals_handle *h;
255 cfs_spin_lock(&handle_hash[i].lock);
256 list_for_each_entry_rcu(h, &(handle_hash[i].head), h_link) {
257 CERROR("force clean handle "LPX64" addr %p addref %p\n",
258 h->h_cookie, h, h->h_addref);
260 class_handle_unhash_nolock(h);
263 cfs_spin_unlock(&handle_hash[i].lock);
269 void class_handle_cleanup(void)
272 LASSERT(handle_hash != NULL);
274 count = cleanup_all_handles();
276 OBD_FREE_LARGE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
280 CERROR("handle_count at cleanup: %d\n", count);