Move the world out of /zfs/ and seperate out module build tree

[zfs.git] / module / zfs / refcount.c

diff --git a/module/zfs/refcount.c b/module/zfs/refcount.c
new file mode 100644 (file)
index 0000000..f1b3b23
--- /dev/null
+++ b/module/zfs/refcount.c
@@ -0,0 +1,195 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident  "%Z%%M% %I%     %E% SMI"
+
+#include <sys/zfs_context.h>
+#include <sys/refcount.h>
+
+#if defined(DEBUG) || !defined(_KERNEL)
+
+#ifdef _KERNEL
+int reference_tracking_enable = FALSE; /* runs out of memory too easily */
+#else
+int reference_tracking_enable = TRUE;
+#endif
+int reference_history = 4; /* tunable */
+
+static kmem_cache_t *reference_cache;
+static kmem_cache_t *reference_history_cache;
+
+void
+refcount_init(void)
+{
+       reference_cache = kmem_cache_create("reference_cache",
+           sizeof (reference_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
+
+       reference_history_cache = kmem_cache_create("reference_history_cache",
+           sizeof (uint64_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
+}
+
+void
+refcount_fini(void)
+{
+       kmem_cache_destroy(reference_cache);
+       kmem_cache_destroy(reference_history_cache);
+}
+
+void
+refcount_create(refcount_t *rc)
+{
+       mutex_init(&rc->rc_mtx, NULL, MUTEX_DEFAULT, NULL);
+       list_create(&rc->rc_list, sizeof (reference_t),
+           offsetof(reference_t, ref_link));
+       list_create(&rc->rc_removed, sizeof (reference_t),
+           offsetof(reference_t, ref_link));
+       rc->rc_count = 0;
+       rc->rc_removed_count = 0;
+}
+
+void
+refcount_destroy_many(refcount_t *rc, uint64_t number)
+{
+       reference_t *ref;
+
+       ASSERT(rc->rc_count == number);
+       while (ref = list_head(&rc->rc_list)) {
+               list_remove(&rc->rc_list, ref);
+               kmem_cache_free(reference_cache, ref);
+       }
+       list_destroy(&rc->rc_list);
+
+       while (ref = list_head(&rc->rc_removed)) {
+               list_remove(&rc->rc_removed, ref);
+               kmem_cache_free(reference_history_cache, ref->ref_removed);
+               kmem_cache_free(reference_cache, ref);
+       }
+       list_destroy(&rc->rc_removed);
+       mutex_destroy(&rc->rc_mtx);
+}
+
+void
+refcount_destroy(refcount_t *rc)
+{
+       refcount_destroy_many(rc, 0);
+}
+
+int
+refcount_is_zero(refcount_t *rc)
+{
+       ASSERT(rc->rc_count >= 0);
+       return (rc->rc_count == 0);
+}
+
+int64_t
+refcount_count(refcount_t *rc)
+{
+       ASSERT(rc->rc_count >= 0);
+       return (rc->rc_count);
+}
+
+int64_t
+refcount_add_many(refcount_t *rc, uint64_t number, void *holder)
+{
+       reference_t *ref;
+       int64_t count;
+
+       if (reference_tracking_enable) {
+               ref = kmem_cache_alloc(reference_cache, KM_SLEEP);
+               ref->ref_holder = holder;
+               ref->ref_number = number;
+       }
+       mutex_enter(&rc->rc_mtx);
+       ASSERT(rc->rc_count >= 0);
+       if (reference_tracking_enable)
+               list_insert_head(&rc->rc_list, ref);
+       rc->rc_count += number;
+       count = rc->rc_count;
+       mutex_exit(&rc->rc_mtx);
+
+       return (count);
+}
+
+int64_t
+refcount_add(refcount_t *rc, void *holder)
+{
+       return (refcount_add_many(rc, 1, holder));
+}
+
+int64_t
+refcount_remove_many(refcount_t *rc, uint64_t number, void *holder)
+{
+       reference_t *ref;
+       int64_t count;
+
+       mutex_enter(&rc->rc_mtx);
+       ASSERT(rc->rc_count >= number);
+
+       if (!reference_tracking_enable) {
+               rc->rc_count -= number;
+               count = rc->rc_count;
+               mutex_exit(&rc->rc_mtx);
+               return (count);
+       }
+
+       for (ref = list_head(&rc->rc_list); ref;
+           ref = list_next(&rc->rc_list, ref)) {
+               if (ref->ref_holder == holder && ref->ref_number == number) {
+                       list_remove(&rc->rc_list, ref);
+                       if (reference_history > 0) {
+                               ref->ref_removed =
+                                   kmem_cache_alloc(reference_history_cache,
+                                   KM_SLEEP);
+                               list_insert_head(&rc->rc_removed, ref);
+                               rc->rc_removed_count++;
+                               if (rc->rc_removed_count >= reference_history) {
+                                       ref = list_tail(&rc->rc_removed);
+                                       list_remove(&rc->rc_removed, ref);
+                                       kmem_cache_free(reference_history_cache,
+                                           ref->ref_removed);
+                                       kmem_cache_free(reference_cache, ref);
+                                       rc->rc_removed_count--;
+                               }
+                       } else {
+                               kmem_cache_free(reference_cache, ref);
+                       }
+                       rc->rc_count -= number;
+                       count = rc->rc_count;
+                       mutex_exit(&rc->rc_mtx);
+                       return (count);
+               }
+       }
+       panic("No such hold %p on refcount %llx", holder,
+           (u_longlong_t)(uintptr_t)rc);
+       return (-1);
+}
+
+int64_t
+refcount_remove(refcount_t *rc, void *holder)
+{
+       return (refcount_remove_many(rc, 1, holder));
+}
+
+#endif