/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
- * Copyright (C) 2002 Cluster File Systems, Inc.
- * Author: Phil Schwan <phil@clusterfs.com>
+ * GPL HEADER START
*
- * This file is part of Lustre, http://www.lustre.org/
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
*
- * Lustre is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
*
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/obdclass/lustre_handles.c
+ *
+ * Author: Phil Schwan <phil@clusterfs.com>
*/
#define DEBUG_SUBSYSTEM S_CLASS
-#ifdef __KERNEL__
-# include <linux/types.h>
-# include <linux/random.h>
-#else
+#ifndef __KERNEL__
# include <liblustre.h>
-#endif
+#endif
+
+#include <obd_support.h>
+#include <lustre_handles.h>
+#include <lustre_lib.h>
+
+#if !defined(HAVE_RCU) || !defined(__KERNEL__)
+# define list_add_rcu cfs_list_add
+# define list_del_rcu cfs_list_del
+# define list_for_each_rcu cfs_list_for_each
+# define list_for_each_safe_rcu cfs_list_for_each_safe
+# define list_for_each_entry_rcu cfs_list_for_each_entry
+# define rcu_read_lock() cfs_spin_lock(&bucket->lock)
+# define rcu_read_unlock() cfs_spin_unlock(&bucket->lock)
+#endif /* ifndef HAVE_RCU */
-#include <linux/obd_support.h>
-#include <linux/lustre_handles.h>
-
-static spinlock_t handle_lock = SPIN_LOCK_UNLOCKED;
static __u64 handle_base;
#define HANDLE_INCR 7
-static struct list_head *handle_hash = NULL;
-static int handle_count = 0;
+static cfs_spinlock_t handle_base_lock;
+
+static struct handle_bucket {
+ cfs_spinlock_t lock;
+ cfs_list_t head;
+} *handle_hash;
+
+#ifdef __arch_um__
+/* For unknown reason, UML uses kmalloc rather than vmalloc to allocate
+ * memory(OBD_VMALLOC). Therefore, we have to redefine the
+ * HANDLE_HASH_SIZE to make the hash heads don't exceed 128K.
+ */
+#define HANDLE_HASH_SIZE 4096
+#else
+#define HANDLE_HASH_SIZE (1 << 16)
+#endif /* ifdef __arch_um__ */
-#define HANDLE_HASH_SIZE (1 << 14)
#define HANDLE_HASH_MASK (HANDLE_HASH_SIZE - 1)
+/*
+ * Generate a unique 64bit cookie (hash) for a handle and insert it into
+ * global (per-node) hash-table.
+ */
void class_handle_hash(struct portals_handle *h, portals_handle_addref_cb cb)
{
- struct list_head *bucket;
+ struct handle_bucket *bucket;
ENTRY;
LASSERT(h != NULL);
- LASSERT(list_empty(&h->h_link));
+ LASSERT(cfs_list_empty(&h->h_link));
- spin_lock(&handle_lock);
- h->h_cookie = handle_base;
+ /*
+ * This is fast, but simplistic cookie generation algorithm, it will
+ * need a re-do at some point in the future for security.
+ */
+ cfs_spin_lock(&handle_base_lock);
handle_base += HANDLE_INCR;
- spin_unlock(&handle_lock);
+ h->h_cookie = handle_base;
+ if (unlikely(handle_base == 0)) {
+ /*
+ * Cookie of zero is "dangerous", because in many places it's
+ * assumed that 0 means "unassigned" handle, not bound to any
+ * object.
+ */
+ CWARN("The universe has been exhausted: cookie wrap-around.\n");
+ handle_base += HANDLE_INCR;
+ }
+ cfs_spin_unlock(&handle_base_lock);
+
h->h_addref = cb;
- bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
- CDEBUG(D_INFO, "adding object %p with handle "LPX64" to hash\n",
- h, h->h_cookie);
+ cfs_spin_lock_init(&h->h_lock);
- spin_lock(&handle_lock);
- list_add(&h->h_link, bucket);
- handle_count++;
- spin_unlock(&handle_lock);
+ bucket = &handle_hash[h->h_cookie & HANDLE_HASH_MASK];
+ cfs_spin_lock(&bucket->lock);
+ list_add_rcu(&h->h_link, &bucket->head);
+ h->h_in = 1;
+ cfs_spin_unlock(&bucket->lock);
+
+ CDEBUG(D_INFO, "added object %p with handle "LPX64" to hash\n",
+ h, h->h_cookie);
EXIT;
}
static void class_handle_unhash_nolock(struct portals_handle *h)
{
- if (list_empty(&h->h_link)) {
+ if (cfs_list_empty(&h->h_link)) {
CERROR("removing an already-removed handle ("LPX64")\n",
h->h_cookie);
return;
CDEBUG(D_INFO, "removing object %p with handle "LPX64" from hash\n",
h, h->h_cookie);
- handle_count--;
- list_del_init(&h->h_link);
+ cfs_spin_lock(&h->h_lock);
+ if (h->h_in == 0) {
+ cfs_spin_unlock(&h->h_lock);
+ return;
+ }
+ h->h_in = 0;
+ cfs_spin_unlock(&h->h_lock);
+ list_del_rcu(&h->h_link);
}
void class_handle_unhash(struct portals_handle *h)
{
- spin_lock(&handle_lock);
+ struct handle_bucket *bucket;
+ bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
+
+ cfs_spin_lock(&bucket->lock);
class_handle_unhash_nolock(h);
- spin_unlock(&handle_lock);
+ cfs_spin_unlock(&bucket->lock);
+}
+
+void class_handle_hash_back(struct portals_handle *h)
+{
+ struct handle_bucket *bucket;
+ ENTRY;
+
+ bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
+
+ cfs_spin_lock(&bucket->lock);
+ list_add_rcu(&h->h_link, &bucket->head);
+ h->h_in = 1;
+ cfs_spin_unlock(&bucket->lock);
+
+ EXIT;
}
void *class_handle2object(__u64 cookie)
{
- struct list_head *bucket, *tmp;
+ struct handle_bucket *bucket;
+ struct portals_handle *h;
void *retval = NULL;
ENTRY;
LASSERT(handle_hash != NULL);
+ /* Be careful when you want to change this code. See the
+ * rcu_read_lock() definition on top this file. - jxiong */
bucket = handle_hash + (cookie & HANDLE_HASH_MASK);
- spin_lock(&handle_lock);
- list_for_each(tmp, bucket) {
- struct portals_handle *h;
- h = list_entry(tmp, struct portals_handle, h_link);
+ rcu_read_lock();
+ list_for_each_entry_rcu(h, &bucket->head, h_link) {
+ if (h->h_cookie != cookie)
+ continue;
- if (h->h_cookie == cookie) {
+ cfs_spin_lock(&h->h_lock);
+ if (likely(h->h_in != 0)) {
h->h_addref(h);
retval = h;
- break;
}
+ cfs_spin_unlock(&h->h_lock);
+ break;
}
- spin_unlock(&handle_lock);
+ rcu_read_unlock();
RETURN(retval);
}
+void class_handle_free_cb(cfs_rcu_head_t *rcu)
+{
+ struct portals_handle *h = RCU2HANDLE(rcu);
+ if (h->h_free_cb) {
+ h->h_free_cb(h->h_ptr, h->h_size);
+ } else {
+ void *ptr = h->h_ptr;
+ unsigned int size = h->h_size;
+ OBD_FREE(ptr, size);
+ }
+}
+
int class_handle_init(void)
{
- struct list_head *bucket;
+ struct handle_bucket *bucket;
+ struct timeval tv;
+ int seed[2];
LASSERT(handle_hash == NULL);
- OBD_VMALLOC(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
+ OBD_ALLOC_LARGE(handle_hash, sizeof(*bucket) * HANDLE_HASH_SIZE);
if (handle_hash == NULL)
return -ENOMEM;
+ cfs_spin_lock_init(&handle_base_lock);
for (bucket = handle_hash + HANDLE_HASH_SIZE - 1; bucket >= handle_hash;
- bucket--)
- INIT_LIST_HEAD(bucket);
+ bucket--) {
+ CFS_INIT_LIST_HEAD(&bucket->head);
+ cfs_spin_lock_init(&bucket->lock);
+ }
+
+ /** bug 21430: add randomness to the initial base */
+ cfs_get_random_bytes(seed, sizeof(seed));
+ cfs_gettimeofday(&tv);
+ cfs_srand(tv.tv_sec ^ seed[0], tv.tv_usec ^ seed[1]);
- get_random_bytes(&handle_base, sizeof(handle_base));
+ cfs_get_random_bytes(&handle_base, sizeof(handle_base));
LASSERT(handle_base != 0ULL);
return 0;
}
-static void cleanup_all_handles(void)
+static int cleanup_all_handles(void)
{
+ int rc;
int i;
- spin_lock(&handle_lock);
- for (i = 0; i < HANDLE_HASH_SIZE; i++) {
- struct list_head *tmp, *pos;
- list_for_each_safe(tmp, pos, &(handle_hash[i])) {
- struct portals_handle *h;
- h = list_entry(tmp, struct portals_handle, h_link);
+ for (rc = i = 0; i < HANDLE_HASH_SIZE; i++) {
+ struct portals_handle *h;
- CERROR("forcing cleanup for handle "LPX64"\n",
- h->h_cookie);
+ cfs_spin_lock(&handle_hash[i].lock);
+ list_for_each_entry_rcu(h, &(handle_hash[i].head), h_link) {
+ CERROR("force clean handle "LPX64" addr %p addref %p\n",
+ h->h_cookie, h, h->h_addref);
class_handle_unhash_nolock(h);
+ rc++;
}
+ cfs_spin_unlock(&handle_hash[i].lock);
}
- spin_unlock(&handle_lock);
+
+ return rc;
}
void class_handle_cleanup(void)
{
+ int count;
LASSERT(handle_hash != NULL);
- if (handle_count != 0) {
- CERROR("handle_count at cleanup: %d\n", handle_count);
- cleanup_all_handles();
- }
+ count = cleanup_all_handles();
- OBD_VFREE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
+ OBD_FREE_LARGE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
handle_hash = NULL;
- if (handle_count)
- CERROR("leaked %d handles\n", handle_count);
+ if (count != 0)
+ CERROR("handle_count at cleanup: %d\n", count);
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff