1 files changed, 137 insertions, 0 deletions
diff --git a/sbin/hastd/rangelock.c b/sbin/hastd/rangelock.c
new file mode 100644
index 0000000..02247d6
--- /dev/null
+++ b/sbin/hastd/rangelock.c
@@ -0,0 +1,137 @@
+/*-
+ * Copyright (c) 2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/queue.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "rangelock.h"
+
+#define	RANGELOCKS_MAGIC	0x94310c
+struct rangelocks {
+	int	 rls_magic;		/* Magic value. */
+	TAILQ_HEAD(, rlock) rls_locks;	/* List of locked ranges. */
+};
+
+struct rlock {
+	off_t	rl_start;
+	off_t	rl_end;
+	TAILQ_ENTRY(rlock) rl_next;
+};
+
+int
+rangelock_init(struct rangelocks **rlsp)
+{
+	struct rangelocks *rls;
+
+	assert(rlsp != NULL);
+
+	rls = malloc(sizeof(*rls));
+	if (rls == NULL)
+		return (-1);
+
+	TAILQ_INIT(&rls->rls_locks);
+
+	rls->rls_magic = RANGELOCKS_MAGIC;
+	*rlsp = rls;
+
+	return (0);
+}
+
+void
+rangelock_free(struct rangelocks *rls)
+{
+	struct rlock *rl;
+
+	assert(rls->rls_magic == RANGELOCKS_MAGIC);
+
+	rls->rls_magic = 0;
+
+	while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) {
+		TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
+		free(rl);
+	}
+	free(rls);
+}
+
+int
+rangelock_add(struct rangelocks *rls, off_t offset, off_t length)
+{
+	struct rlock *rl;
+
+	assert(rls->rls_magic == RANGELOCKS_MAGIC);
+
+	rl = malloc(sizeof(*rl));
+	if (rl == NULL)
+		return (-1);
+	rl->rl_start = offset;
+	rl->rl_end = offset + length;
+	TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next);
+	return (0);
+}
+
+void
+rangelock_del(struct rangelocks *rls, off_t offset, off_t length)
+{
+	struct rlock *rl;
+
+	assert(rls->rls_magic == RANGELOCKS_MAGIC);
+
+	TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
+		if (rl->rl_start == offset && rl->rl_end == offset + length)
+			break;
+	}
+	assert(rl != NULL);
+	TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
+	free(rl);
+}
+
+bool
+rangelock_islocked(struct rangelocks *rls, off_t offset, off_t length)
+{
+	struct rlock *rl;
+
+	assert(rls->rls_magic == RANGELOCKS_MAGIC);
+
+	TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
+		if (rl->rl_start >= offset && rl->rl_start < offset + length)
+			break;
+		else if (rl->rl_end > offset && rl->rl_end <= offset + length)
+			break;
+		else if (rl->rl_start < offset && rl->rl_end > offset + length)
+			break;
+	}
+	return (rl != NULL);
+}