PSARC/2006/519 Metadevice Names in iostat/vmstat Output

4981132 iostat -Ecte header mal-formed
6402814 Solaris 10 vmstat performance degradation, due to excessive calls to libdevinfo
6464368 iostat and mpstat call kstat_open, but not kstat_close
6466406 kstat: default_kstat_snapshot() should only set lastupdate for incomplete transactions.
6467122 di_devlink_init leaks, missing free of db_dir in handle_free

1 files changed, 149 insertions, 0 deletions

diff --git a/usr/src/lib/libdevinfo/devinfo_dim.c b/usr/src/lib/libdevinfo/devinfo_dim.c
new file mode 100644
index 0000000000..141f5a9514
--- /dev/null
+++ b/usr/src/lib/libdevinfo/devinfo_dim.c
@@ -0,0 +1,149 @@
+/*
+ * 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 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include "libdevinfo.h"
+#include <strings.h>
+#include <sys/modctl.h>
+
+/*
+ *
+ * This file contains interfaces to translate <driver><instance><minorname>
+ * information into /devices and /dev paths.  It does this using interfaces to
+ * the kernel instance tree so that it can provide translations for devices
+ * which are no longer present. An example consumer of these interfaces is
+ * iostat(1M) - which shows, in its first iteration, activity since reboot.
+ * With persistant kstats, a device which was busy a long time ago can still
+ * have a decaying presence in iostat output, and that output, when '-n' is
+ * used, should show the public name.
+ */
+
+typedef	struct {
+	di_devlink_handle_t	i_devlink_hdl;
+} *idim_t;
+
+di_dim_t
+di_dim_init()
+{
+	idim_t		idim;
+
+	if ((idim = (idim_t)malloc(sizeof (*idim))) == NULL)
+		return (NULL);
+	idim->i_devlink_hdl = di_devlink_init(NULL, 0);
+	if (idim->i_devlink_hdl == NULL) {
+		free(idim);
+		return (NULL);
+	}
+	return ((di_dim_t)idim);
+}
+
+void
+di_dim_fini(di_dim_t dim)
+{
+	idim_t	idim = (idim_t)dim;
+
+	if (idim->i_devlink_hdl) {
+		(void) di_devlink_fini(&idim->i_devlink_hdl);
+	}
+	free(idim);
+}
+
+/*ARGSUSED*/
+char *
+di_dim_path_devices(di_dim_t dim, char *drv_name, int instance,
+    char *minor_name)
+{
+	major_t	major;
+	int	len;
+	int	mlen;
+	char	*devices;
+
+	/* convert drv_name to major_t */
+	if (modctl(MODGETMAJBIND, drv_name, strlen(drv_name) + 1, &major) < 0)
+		return (NULL);
+
+	/* find the length of the devices path given major,instance */
+	if (modctl(MODGETDEVFSPATH_MI_LEN, major, instance, &len) != 0)
+		return (NULL);
+
+	/*
+	 * MODGETDEVFSPATH_MI_LEN result includes '\0' termination, but we
+	 * may need to add space for ":<minor_name>"
+	 */
+	if (minor_name)
+		mlen = len + 1 + strlen(minor_name);
+	else
+		mlen = len;
+	if ((devices = (char *)malloc(mlen)) == NULL)
+		return (NULL);
+
+	if (modctl(MODGETDEVFSPATH_MI, major, instance, len, devices) != 0) {
+		free(devices);
+		return (NULL);
+	}
+
+	if (minor_name) {
+		/* add ':<minot_name>' to the end of /devices path */
+		(void) strcat(devices, ":");
+		(void) strcat(devices, minor_name);
+	}
+	return (devices);
+}
+
+/* di_dim_path_dev di_devlink callback */
+static int
+di_dim_path_dev_callback(di_devlink_t dl, void *arg)
+{
+	char		**devp = (char **)arg;
+	char		*devpath = (char *)di_devlink_path(dl);
+
+	if (devpath)
+		*devp = strdup(devpath);
+	return (DI_WALK_TERMINATE);
+}
+
+char *
+di_dim_path_dev(di_dim_t dim, char *drv_name, int instance, char *minor_name)
+{
+	idim_t	idim = (idim_t)dim;
+	char	*devices;
+	char	*dev = NULL;
+
+	/* we must have a minor_name to resolve to a public name */
+	if (minor_name == NULL)
+		return (NULL);
+
+	/* convert <driver><instance><minor_name> to /devices path */
+	devices = di_dim_path_devices(dim, drv_name, instance, minor_name);
+	if (devices == NULL)
+		return (NULL);
+
+	/* convert /devices path to /dev path */
+	(void) di_devlink_walk(idim->i_devlink_hdl, NULL,
+	    devices, DI_PRIMARY_LINK, (void *)&dev, di_dim_path_dev_callback);
+	free(devices);
+	return (dev);
+}