1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (C) 2002 Cluster File Systems, Inc.
5 * Author: Phil Schwan <phil@clusterfs.com>
7 * This file is part of the Lustre file system, http://www.lustre.org
8 * Lustre is a trademark of Cluster File Systems, Inc.
10 * You may have signed or agreed to another license before downloading
11 * this software. If so, you are bound by the terms and conditions
12 * of that agreement, and the following does not apply to you. See the
13 * LICENSE file included with this distribution for more information.
15 * If you did not agree to a different license, then this copy of Lustre
16 * is open source software; you can redistribute it and/or modify it
17 * under the terms of version 2 of the GNU General Public License as
18 * published by the Free Software Foundation.
20 * In either case, Lustre is distributed in the hope that it will be
21 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
22 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * license text for more details.
26 #define DEBUG_SUBSYSTEM S_CLASS
28 # include <liblustre.h>
31 #include <obd_support.h>
32 #include <lustre_handles.h>
33 #include <lustre_lib.h>
35 #if !defined(HAVE_RCU) || !defined(__KERNEL__)
36 # define list_add_rcu list_add
37 # define list_del_rcu list_del
38 # define list_for_each_rcu list_for_each
39 # define list_for_each_safe_rcu list_for_each_safe
40 # define rcu_read_lock() spin_lock(&bucket->lock)
41 # define rcu_read_unlock() spin_unlock(&bucket->lock)
42 #endif /* ifndef HAVE_RCU */
44 static __u64 handle_base;
46 static spinlock_t handle_base_lock;
48 static struct handle_bucket {
50 struct list_head head;
53 static atomic_t handle_count = ATOMIC_INIT(0);
55 #define HANDLE_HASH_SIZE (1 << 14)
56 #define HANDLE_HASH_MASK (HANDLE_HASH_SIZE - 1)
59 * Generate a unique 64bit cookie (hash) for a handle and insert it into
60 * global (per-node) hash-table.
62 void class_handle_hash(struct portals_handle *h, portals_handle_addref_cb cb)
64 struct handle_bucket *bucket;
68 LASSERT(list_empty(&h->h_link));
71 * This is fast, but simplistic cookie generation algorithm, it will
72 * need a re-do at some point in the future for security.
74 spin_lock(&handle_base_lock);
75 handle_base += HANDLE_INCR;
77 h->h_cookie = handle_base;
78 if (unlikely(handle_base == 0)) {
80 * Cookie of zero is "dangerous", because in many places it's
81 * assumed that 0 means "unassigned" handle, not bound to any
84 CWARN("The universe has been exhausted: cookie wrap-around.\n");
85 handle_base += HANDLE_INCR;
87 spin_unlock(&handle_base_lock);
89 atomic_inc(&handle_count);
91 spin_lock_init(&h->h_lock);
93 bucket = &handle_hash[h->h_cookie & HANDLE_HASH_MASK];
94 spin_lock(&bucket->lock);
95 list_add_rcu(&h->h_link, &bucket->head);
97 spin_unlock(&bucket->lock);
99 CDEBUG(D_INFO, "added object %p with handle "LPX64" to hash\n",
104 static void class_handle_unhash_nolock(struct portals_handle *h)
106 if (list_empty(&h->h_link)) {
107 CERROR("removing an already-removed handle ("LPX64")\n",
112 CDEBUG(D_INFO, "removing object %p with handle "LPX64" from hash\n",
115 spin_lock(&h->h_lock);
117 spin_unlock(&h->h_lock);
121 spin_unlock(&h->h_lock);
122 list_del_rcu(&h->h_link);
125 void class_handle_unhash(struct portals_handle *h)
127 struct handle_bucket *bucket;
128 bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
130 spin_lock(&bucket->lock);
131 class_handle_unhash_nolock(h);
132 spin_unlock(&bucket->lock);
134 atomic_dec(&handle_count);
137 void class_handle_hash_back(struct portals_handle *h)
139 struct handle_bucket *bucket;
142 bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
144 atomic_inc(&handle_count);
145 spin_lock(&bucket->lock);
146 list_add_rcu(&h->h_link, &bucket->head);
148 spin_unlock(&bucket->lock);
153 void *class_handle2object(__u64 cookie)
155 struct handle_bucket *bucket;
156 struct list_head *tmp;
160 LASSERT(handle_hash != NULL);
162 /* Be careful when you want to change this code. See the
163 * rcu_read_lock() definition on top this file. - jxiong */
164 bucket = handle_hash + (cookie & HANDLE_HASH_MASK);
167 list_for_each_rcu(tmp, &bucket->head) {
168 struct portals_handle *h;
169 h = list_entry(tmp, struct portals_handle, h_link);
170 if (h->h_cookie != cookie)
173 spin_lock(&h->h_lock);
174 if (likely(h->h_cookie != 0)) {
178 spin_unlock(&h->h_lock);
186 void class_handle_free_cb(struct rcu_head *rcu)
188 struct portals_handle *h = RCU2HANDLE(rcu);
190 h->h_free_cb(h->h_ptr, h->h_size);
192 void *ptr = h->h_ptr;
193 unsigned int size = h->h_size;
198 int class_handle_init(void)
200 struct handle_bucket *bucket;
202 LASSERT(handle_hash == NULL);
204 OBD_VMALLOC(handle_hash, sizeof(*bucket) * HANDLE_HASH_SIZE);
205 if (handle_hash == NULL)
208 spin_lock_init(&handle_base_lock);
209 for (bucket = handle_hash + HANDLE_HASH_SIZE - 1; bucket >= handle_hash;
211 CFS_INIT_LIST_HEAD(&bucket->head);
212 spin_lock_init(&bucket->lock);
214 ll_get_random_bytes(&handle_base, sizeof(handle_base));
215 LASSERT(handle_base != 0ULL);
220 static void cleanup_all_handles(void)
224 for (i = 0; i < HANDLE_HASH_SIZE; i++) {
225 struct list_head *tmp, *pos;
226 spin_lock(&handle_hash[i].lock);
227 list_for_each_safe_rcu(tmp, pos, &(handle_hash[i].head)) {
228 struct portals_handle *h;
229 h = list_entry(tmp, struct portals_handle, h_link);
231 CERROR("force clean handle "LPX64" addr %p addref %p\n",
232 h->h_cookie, h, h->h_addref);
234 class_handle_unhash_nolock(h);
236 spin_unlock(&handle_hash[i].lock);
240 void class_handle_cleanup(void)
243 LASSERT(handle_hash != NULL);
245 count = atomic_read(&handle_count);
247 CERROR("handle_count at cleanup: %d\n", count);
248 cleanup_all_handles();
251 OBD_VFREE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
254 if (atomic_read(&handle_count))
255 CERROR("leaked %d handles\n", atomic_read(&handle_count));