* Copyright (C) 2002 Cluster File Systems, Inc.
* Author: Phil Schwan <phil@clusterfs.com>
*
- * This file is part of Portals, http://www.sf.net/projects/sandiaportals/
+ * This file is part of the Lustre file system, http://www.lustre.org
+ * Lustre is a trademark of Cluster File Systems, Inc.
*
- * Portals is free software; you can redistribute it and/or
- * modify it under the terms of version 2.1 of the GNU Lesser General
- * Public License as published by the Free Software Foundation.
+ * You may have signed or agreed to another license before downloading
+ * this software. If so, you are bound by the terms and conditions
+ * of that agreement, and the following does not apply to you. See the
+ * LICENSE file included with this distribution for more information.
*
- * Portals 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 Lesser General Public License for more details.
+ * If you did not agree to a different license, then this copy of Lustre
+ * is open source 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.
*
- * You should have received a copy of the GNU Lesser General Public
- * License along with Portals; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * In either case, 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
+ * license text for more details.
*/
-#define DEBUG_SUBSYSTEM S_PORTALS
-#ifdef __KERNEL__
-#include <linux/types.h>
-#include <linux/random.h>
-#else
-#include <liblustre.h>
-#endif
+#define DEBUG_SUBSYSTEM S_CLASS
+#ifndef __KERNEL__
+# include <liblustre.h>
+#endif
+#include <obd_support.h>
+#include <lustre_handles.h>
+#include <lustre_lib.h>
-#include <linux/kp30.h>
-#include <linux/lustre_handles.h>
+#if !defined(HAVE_RCU) || !defined(__KERNEL__)
+# define list_add_rcu list_add
+# define list_del_rcu list_del
+# define list_for_each_rcu list_for_each
+# define list_for_each_safe_rcu list_for_each_safe
+# define rcu_read_lock() spin_lock(&bucket->lock)
+# define rcu_read_unlock() spin_unlock(&bucket->lock)
+#endif /* ifndef HAVE_RCU */
-static spinlock_t handle_lock = SPIN_LOCK_UNLOCKED;
-static spinlock_t random_lock = SPIN_LOCK_UNLOCKED;
-static struct list_head *handle_hash = NULL;
-static int handle_count = 0;
+static __u64 handle_base;
+#define HANDLE_INCR 7
+static spinlock_t handle_base_lock;
+
+static struct handle_bucket {
+ spinlock_t lock;
+ struct list_head head;
+} *handle_hash;
+
+static atomic_t handle_count = ATOMIC_INIT(0);
#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));
- /* My hypothesis is that get_random_bytes, if called from two threads at
- * the same time, will return the same bytes. -phil */
- spin_lock(&random_lock);
- get_random_bytes(&h->h_cookie, sizeof(h->h_cookie));
- spin_unlock(&random_lock);
-
+ /*
+ * This is fast, but simplistic cookie generation algorithm, it will
+ * need a re-do at some point in the future for security.
+ */
+ spin_lock(&handle_base_lock);
+ handle_base += HANDLE_INCR;
+
+ 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;
+ }
+ spin_unlock(&handle_base_lock);
+
+ atomic_inc(&handle_count);
h->h_addref = cb;
+ spin_lock_init(&h->h_lock);
- bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
+ bucket = &handle_hash[h->h_cookie & HANDLE_HASH_MASK];
+ spin_lock(&bucket->lock);
+ list_add_rcu(&h->h_link, &bucket->head);
+ h->h_in = 1;
+ spin_unlock(&bucket->lock);
- CDEBUG(D_INFO, "adding object %p with handle "LPX64" to hash\n",
+ CDEBUG(D_INFO, "added object %p with handle "LPX64" to hash\n",
h, h->h_cookie);
-
- spin_lock(&handle_lock);
- list_add(&h->h_link, bucket);
- handle_count++;
- spin_unlock(&handle_lock);
EXIT;
}
static void class_handle_unhash_nolock(struct portals_handle *h)
{
- LASSERT(!list_empty(&h->h_link));
+ if (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);
+ spin_lock(&h->h_lock);
+ if (h->h_in == 0) {
+ spin_unlock(&h->h_lock);
+ return;
+ }
+ h->h_in = 0;
+ 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);
+
+ spin_lock(&bucket->lock);
class_handle_unhash_nolock(h);
- spin_unlock(&handle_lock);
+ spin_unlock(&bucket->lock);
+
+ atomic_dec(&handle_count);
+}
+
+void class_handle_hash_back(struct portals_handle *h)
+{
+ struct handle_bucket *bucket;
+ ENTRY;
+
+ bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
+
+ atomic_inc(&handle_count);
+ spin_lock(&bucket->lock);
+ list_add_rcu(&h->h_link, &bucket->head);
+ h->h_in = 1;
+ spin_unlock(&bucket->lock);
+
+ EXIT;
}
void *class_handle2object(__u64 cookie)
{
- struct list_head *bucket, *tmp;
+ struct handle_bucket *bucket;
+ struct list_head *tmp;
void *retval = NULL;
ENTRY;
LASSERT(handle_hash != NULL);
- spin_lock(&handle_lock);
+ /* 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);
- list_for_each(tmp, bucket) {
+ rcu_read_lock();
+ list_for_each_rcu(tmp, &bucket->head) {
struct portals_handle *h;
h = list_entry(tmp, struct portals_handle, h_link);
+ if (h->h_cookie != cookie)
+ continue;
- if (h->h_cookie == cookie) {
+ spin_lock(&h->h_lock);
+ if (likely(h->h_cookie != 0)) {
h->h_addref(h);
retval = h;
- break;
}
+ spin_unlock(&h->h_lock);
+ break;
}
- spin_unlock(&handle_lock);
+ rcu_read_unlock();
RETURN(retval);
}
+void class_handle_free_cb(struct rcu_head *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;
LASSERT(handle_hash == NULL);
- PORTAL_ALLOC(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
+ OBD_VMALLOC(handle_hash, sizeof(*bucket) * HANDLE_HASH_SIZE);
if (handle_hash == NULL)
return -ENOMEM;
+ 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);
+ spin_lock_init(&bucket->lock);
+ }
+ ll_get_random_bytes(&handle_base, sizeof(handle_base));
+ LASSERT(handle_base != 0ULL);
return 0;
}
{
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])) {
+ spin_lock(&handle_hash[i].lock);
+ list_for_each_safe_rcu(tmp, pos, &(handle_hash[i].head)) {
struct portals_handle *h;
h = list_entry(tmp, struct portals_handle, h_link);
- CERROR("forcing cleanup for handle "LPX64"\n",
- h->h_cookie);
+ CERROR("force clean handle "LPX64" addr %p addref %p\n",
+ h->h_cookie, h, h->h_addref);
class_handle_unhash_nolock(h);
}
+ spin_unlock(&handle_hash[i].lock);
}
- spin_lock(&handle_lock);
}
void class_handle_cleanup(void)
{
+ int count;
LASSERT(handle_hash != NULL);
- if (handle_count != 0) {
- CERROR("handle_count at cleanup: %d\n", handle_count);
+ count = atomic_read(&handle_count);
+ if (count != 0) {
+ CERROR("handle_count at cleanup: %d\n", count);
cleanup_all_handles();
}
- PORTAL_FREE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
+ OBD_VFREE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
handle_hash = NULL;
- if (handle_count)
- CERROR("leaked %d handles\n", handle_count);
+ if (atomic_read(&handle_count))
+ CERROR("leaked %d handles\n", atomic_read(&handle_count));
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff