[PATCH] disable logging for udevstart

The slow logging facilites on some systems are a reason for
the reported slowness of udevstart. On one of my boxes udevstart
is down from 9 second to 0.3 seconds.

1 files changed, 300 insertions, 0 deletions

diff --git a/udev_start.c b/udev_start.c
new file mode 100644
index 0000000000..c1d877fb37
--- /dev/null
+++ b/udev_start.c
@@ -0,0 +1,300 @@
+/*
+ * udevstart.c
+ *
+ * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ * 
+ * Quick and dirty way to populate a /dev with udev if your system
+ * does not have access to a shell.  Based originally on a patch to udev 
+ * from Harald Hoyer <harald@redhat.com>
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License as published by the
+ *	Free Software Foundation version 2 of the License.
+ * 
+ *	This program 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
+ *	General Public License for more details.
+ * 
+ *	You should have received a copy of the GNU General Public License along
+ *	with this program; if not, write to the Free Software Foundation, Inc.,
+ *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "libsysfs/sysfs/libsysfs.h"
+#include "logging.h"
+#include "udev_lib.h"
+#include "list.h"
+#include "udev.h"
+
+
+#define MAX_PATHLEN		1024
+#define SYSBLOCK		"/sys/block"
+#define SYSCLASS		"/sys/class"
+
+struct device {
+	struct list_head list;
+	char path[MAX_PATHLEN];
+	char subsys[MAX_PATHLEN];
+};
+
+/* sort files in lexical order */
+static int device_list_insert(char *path, char *subsystem, struct list_head *device_list)
+{
+	struct device *loop_device;
+	struct device *new_device;
+
+	list_for_each_entry(loop_device, device_list, list) {
+		if (strcmp(loop_device->path, path) > 0) {
+			break;
+		}
+	}
+
+	new_device = malloc(sizeof(struct device));
+	if (new_device == NULL) {
+		dbg("error malloc");
+		return -ENOMEM;
+	}
+
+	strfieldcpy(new_device->path, path);
+	strfieldcpy(new_device->subsys, subsystem);
+	list_add_tail(&new_device->list, &loop_device->list);
+	dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
+	return 0;
+}
+
+/* list of devices that we should run last due to any one of a number of reasons */
+static char *last_list[] = {
+	"/block/dm",	/* on here because dm wants to have the block devices around before it */
+	NULL,
+};
+
+/* list of devices that we should run first due to any one of a number of reasons */
+static char *first_list[] = {
+	"/class/mem",	/* people tend to like their memory devices around first... */
+	NULL,
+};
+
+static int add_device(char *devpath, char *subsystem)
+{
+	struct udevice udev;
+	char path[SYSFS_PATH_MAX];
+	struct sysfs_class_device *class_dev;
+
+	/* set environment for callouts and dev.d/ */
+	setenv("DEVPATH", devpath, 1);
+	setenv("SUBSYSTEM", subsystem, 1);
+
+	snprintf(path, SYSFS_PATH_MAX, "%s%s", sysfs_path, devpath);
+	path[SYSFS_PATH_MAX-1] = '\0';
+	class_dev = sysfs_open_class_device_path(path);
+	if (class_dev == NULL) {
+		dbg ("sysfs_open_class_device_path failed");
+		return -ENODEV;
+	}
+
+	udev_set_values(&udev, devpath, subsystem, "add");
+	udev_add_device(&udev, class_dev);
+
+	/* run dev.d/ scripts if we created a node or changed a netif name */
+	if (udev.devname[0] != '\0') {
+		setenv("DEVNAME", udev.devname, 1);
+		dev_d_execute(&udev, DEVD_DIR, DEVD_SUFFIX);
+	}
+
+	sysfs_close_class_device(class_dev);
+
+	return 0;
+}
+
+static void exec_list(struct list_head *device_list)
+{
+	struct device *loop_device;
+	struct device *tmp_device;
+	int i;
+
+	/* handle the "first" type devices first */
+	list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
+		for (i=0; first_list[i] != NULL; i++) {
+			if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
+				add_device(loop_device->path, loop_device->subsys);
+				list_del(&loop_device->list);
+				free(loop_device);
+				break;
+			}
+		}
+	}
+
+	/* handle the devices we are allowed to, excluding the "last" type devices */
+	list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
+		int found = 0;
+		for (i=0; last_list[i] != NULL; i++) {
+			if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
+				found = 1;
+				break;
+			}
+		}
+		if (found)
+			continue;
+
+		add_device(loop_device->path, loop_device->subsys);
+		list_del(&loop_device->list);
+		free(loop_device);
+	}
+
+	/* handle the rest of the devices left over, if any */
+	list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
+		add_device(loop_device->path, loop_device->subsys);
+		list_del(&loop_device->list);
+		free(loop_device);
+	}
+}
+
+static void udev_scan_block(void)
+{
+	DIR *dir;
+	struct dirent *dent;
+	LIST_HEAD(device_list);
+
+	dir = opendir(SYSBLOCK);
+	if (dir != NULL) {
+		for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+			char dirname[MAX_PATHLEN];
+			DIR *dir2;
+			struct dirent *dent2;
+
+			if ((strcmp(dent->d_name, ".") == 0) ||
+			    (strcmp(dent->d_name, "..") == 0))
+				continue;
+
+			snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
+			dirname[MAX_PATHLEN-1] = '\0';
+			device_list_insert(dirname, "block", &device_list);
+
+			snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
+			dir2 = opendir(dirname);
+			if (dir2 != NULL) {
+				for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
+					char dirname2[MAX_PATHLEN];
+					DIR *dir3;
+					struct dirent *dent3;
+
+					if ((strcmp(dent2->d_name, ".") == 0) ||
+					    (strcmp(dent2->d_name, "..") == 0))
+						continue;
+
+					snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
+					dirname2[MAX_PATHLEN-1] = '\0';
+
+					dir3 = opendir(dirname2);
+					if (dir3 != NULL) {
+						for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
+							char filename[MAX_PATHLEN];
+
+							if (strcmp(dent3->d_name, "dev") == 0) {
+								snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
+									 dent->d_name, dent2->d_name);
+								filename[MAX_PATHLEN-1] = '\0';
+								device_list_insert(filename, "block", &device_list);
+							}
+						}
+						closedir(dir3);
+					}
+				}
+				closedir(dir2);
+			}
+		}
+		closedir(dir);
+	}
+
+	exec_list(&device_list);
+}
+
+static void udev_scan_class(void)
+{
+	DIR *dir;
+	struct dirent *dent;
+	LIST_HEAD(device_list);
+
+	dir = opendir(SYSCLASS);
+	if (dir != NULL) {
+		for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+			char dirname[MAX_PATHLEN];
+			DIR *dir2;
+			struct dirent *dent2;
+
+			if ((strcmp(dent->d_name, ".") == 0) ||
+			    (strcmp(dent->d_name, "..") == 0))
+				continue;
+
+			snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
+			dirname[MAX_PATHLEN-1] = '\0';
+			dir2 = opendir(dirname);
+			if (dir2 != NULL) {
+				for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
+					char dirname2[MAX_PATHLEN];
+					DIR *dir3;
+					struct dirent *dent3;
+
+					if ((strcmp(dent2->d_name, ".") == 0) ||
+					    (strcmp(dent2->d_name, "..") == 0))
+						continue;
+
+					/* pass the net class as it is */
+					if (strcmp(dent->d_name, "net") == 0) {
+						snprintf(dirname2, MAX_PATHLEN, "/class/net/%s", dent2->d_name);
+						device_list_insert(dirname2, "net", &device_list);
+						continue;
+					}
+
+					snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
+					dirname2[MAX_PATHLEN-1] = '\0';
+					dir3 = opendir(dirname2);
+					if (dir3 != NULL) {
+						for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
+							char filename[MAX_PATHLEN];
+
+							/* pass devices with a "dev" file */
+							if (strcmp(dent3->d_name, "dev") == 0) {
+								snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
+									 dent->d_name, dent2->d_name);
+								filename[MAX_PATHLEN-1] = '\0';
+								device_list_insert(filename, dent->d_name, &device_list);
+								break;
+							}
+						}
+						closedir(dir3);
+					}
+				}
+				closedir(dir2);
+			}
+		}
+		closedir(dir);
+	}
+
+	exec_list(&device_list);
+}
+
+int udev_start(void)
+{
+	/* set environment for callouts and dev.d/ */
+	setenv("ACTION", "add", 1);
+	setenv("UDEVSTART", "1", 1);
+
+	udev_scan_class();
+	udev_scan_block();
+
+	return 0;
+}