Initial implementation of zed (ZFS Event Daemon)

zed monitors ZFS events.  When a zevent is posted, zed will run any
scripts that have been enabled for the corresponding zevent class.
Multiple scripts may be invoked for a given zevent.  The zevent
nvpairs are passed to the scripts as environment variables.

Events are processed synchronously by the single thread, and there is
no maximum timeout for script execution.  Consequently, a misbehaving
script can delay (or forever block) the processing of subsequent
zevents.  Plans are to address this in future commits.

Initial scripts have been developed to log events to syslog
and send email in response to checksum/data/io errors and
resilver.finish/scrub.finish events.  By default, email will only
be sent if the ZED_EMAIL variable is configured in zed.rc (which is
serving as a config file of sorts until a proper configuration file
is implemented).

Signed-off-by: Chris Dunlap <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Issue #2

1 files changed, 200 insertions, 0 deletions

diff --git a/cmd/zed/zed_strings.c b/cmd/zed/zed_strings.c
new file mode 100644
index 000000000..05a374055
--- /dev/null
+++ b/cmd/zed/zed_strings.c
@@ -0,0 +1,200 @@
+/*
+ * 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 from the top-level
+ * OPENSOLARIS.LICENSE or <http://opensource.org/licenses/CDDL-1.0>.
+ * 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 from the top-level 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
+ */
+
+/*
+ * Developed at Lawrence Livermore National Laboratory (LLNL-CODE-403049).
+ * Copyright (C) 2013-2014 Lawrence Livermore National Security, LLC.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/avl.h>
+#include <sys/sysmacros.h>
+#include "zed_strings.h"
+
+struct zed_strings {
+	avl_tree_t tree;
+	avl_node_t *iteratorp;
+};
+
+struct zed_strings_node {
+	avl_node_t node;
+	char string[];
+};
+
+typedef struct zed_strings_node zed_strings_node_t;
+
+/*
+ * Compare zed_strings_node_t nodes [x1] and [x2].
+ * As required for the AVL tree, return exactly
+ *   -1 for <, 0 for ==, and +1 for >.
+ */
+static int
+_zed_strings_node_compare(const void *x1, const void *x2)
+{
+	const char *s1;
+	const char *s2;
+	int rv;
+
+	assert(x1 != NULL);
+	assert(x2 != NULL);
+
+	s1 = ((const zed_strings_node_t *) x1)->string;
+	assert(s1 != NULL);
+	s2 = ((const zed_strings_node_t *) x2)->string;
+	assert(s2 != NULL);
+	rv = strcmp(s1, s2);
+
+	if (rv < 0)
+		return (-1);
+
+	if (rv > 0)
+		return (1);
+
+	return (0);
+}
+
+/*
+ * Return a new string container, or NULL on error.
+ */
+zed_strings_t *
+zed_strings_create(void)
+{
+	zed_strings_t *zsp;
+
+	zsp = malloc(sizeof (*zsp));
+	if (!zsp)
+		return (NULL);
+
+	memset(zsp, 0, sizeof (*zsp));
+	avl_create(&zsp->tree, _zed_strings_node_compare,
+	    sizeof (zed_strings_node_t), offsetof(zed_strings_node_t, node));
+
+	zsp->iteratorp = NULL;
+	return (zsp);
+}
+
+/*
+ * Destroy the string container [zsp] and all strings within.
+ */
+void
+zed_strings_destroy(zed_strings_t *zsp)
+{
+	void *cookie;
+	zed_strings_node_t *np;
+
+	if (!zsp)
+		return;
+
+	cookie = NULL;
+	while ((np = avl_destroy_nodes(&zsp->tree, &cookie)))
+		free(np);
+
+	avl_destroy(&zsp->tree);
+	free(zsp);
+}
+
+/*
+ * Add a copy of the string [s] to the container [zsp].
+ * Return 0 on success, or -1 on error.
+ * FIXME: Handle dup strings.
+ */
+int
+zed_strings_add(zed_strings_t *zsp, const char *s)
+{
+	size_t len;
+	zed_strings_node_t *np;
+
+	if (!zsp || !s) {
+		errno = EINVAL;
+		return (-1);
+	}
+	len = sizeof (zed_strings_node_t) + strlen(s) + 1;
+	np = malloc(len);
+	if (!np)
+		return (-1);
+
+	memset(np, 0, len);
+	assert((char *) np->string + strlen(s) < (char *) np + len);
+	(void) strcpy(np->string, s);
+	avl_add(&zsp->tree, np);
+	return (0);
+}
+
+/*
+ * Return the first string in container [zsp].
+ * Return NULL if there are no strings, or on error.
+ * This can be called multiple times to re-traverse [zsp].
+ * XXX: Not thread-safe.
+ */
+const char *
+zed_strings_first(zed_strings_t *zsp)
+{
+	if (!zsp) {
+		errno = EINVAL;
+		return (NULL);
+	}
+	zsp->iteratorp = avl_first(&zsp->tree);
+	if (!zsp->iteratorp)
+		return (NULL);
+
+	return (((zed_strings_node_t *) zsp->iteratorp)->string);
+
+}
+
+/*
+ * Return the next string in container [zsp].
+ * Return NULL after the last string, or on error.
+ * This must be called after zed_strings_first().
+ * XXX: Not thread-safe.
+ */
+const char *
+zed_strings_next(zed_strings_t *zsp)
+{
+	if (!zsp) {
+		errno = EINVAL;
+		return (NULL);
+	}
+	if (!zsp->iteratorp)
+		return (NULL);
+
+	zsp->iteratorp = AVL_NEXT(&zsp->tree, zsp->iteratorp);
+	if (!zsp->iteratorp)
+		return (NULL);
+
+	return (((zed_strings_node_t *)zsp->iteratorp)->string);
+}
+
+/*
+ * Return the number of strings in container [zsp], or -1 on error.
+ */
+int
+zed_strings_count(zed_strings_t *zsp)
+{
+	if (!zsp) {
+		errno = EINVAL;
+		return (-1);
+	}
+	return (avl_numnodes(&zsp->tree));
+}