[PATCH] Make udev/udevstart be one binary

Hi,

The following patch makes udev/udevstart be a common binary.  First,
doing this grows udev by a total of 1.8kB (ppc32, stripped) whereas
udevstart by itself is 6.4kB.  I know you mentioned being able to
replace udevstart with a script, but at 1.8kB I don't think it'll be
easy to beat this with size there.  Next, the following are by-eye
timings of before, after, and with devfs on a slow, but still usable
embedded platform (config stripped down to more-or-less bare for
ramdisk):
-- Embedded Planet RPX LITE, 64Mhz MPC 823e --
devfs         : 15.333s, 15.253s, 14.988s (15.191s avg)
udev-pristine : 18.675s, 18.079s, 18.418s (18.390s avg)
udev-multi    : 14.587s, 14.747s, 14.868s (14.734s avg)

The patch ends up being rather large to add this, as in doing so I ended
up making all refs (that I hit..) to devpath/subsystem be marked as
'const'.


Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

7 files changed, 67 insertions, 80 deletions

diff --git a/Makefile b/Makefile
index f4f371d463..d4d3ac8b05 100644
--- a/Makefile
+++ b/Makefile
@@ -172,7 +172,7 @@ endif
 
 CFLAGS += -I$(PWD)/libsysfs
 
-all: $(ROOT) $(SENDER) $(DAEMON) $(INFO) $(TESTER) $(STARTER)
+all: $(ROOT) $(SENDER) $(DAEMON) $(INFO) $(TESTER)
 	@extras="$(EXTRAS)" ; for target in $$extras ; do \
 		echo $$target ; \
 		$(MAKE) prefix=$(prefix) \
@@ -261,8 +261,8 @@ $(DAEMON).o: $(GEN_HEADERS)
 $(SENDER).o: $(GEN_HEADERS)
 $(STARTER).o: $(GEN_HEADERS)
 
-$(ROOT): $(ROOT).o $(OBJS) $(HEADERS) $(LIBC) $(GEN_MANPAGES)
-	$(LD) $(LDFLAGS) -o $@ $(CRT0) udev.o $(OBJS) $(LIB_OBJS) $(ARCH_LIB_OBJS)
+$(ROOT): $(ROOT).o $(STARTER).o $(OBJS) $(HEADERS) $(LIBC) $(GEN_MANPAGES)
+	$(LD) $(LDFLAGS) -o $@ $(CRT0) udev.o udevstart.o $(OBJS) $(LIB_OBJS) $(ARCH_LIB_OBJS)
 	$(STRIPCMD) $@
 
 $(TESTER): $(TESTER).o $(OBJS) $(HEADERS) $(LIBC)
@@ -281,10 +281,6 @@ $(SENDER): $(SENDER).o udevd.h $(LIBC)
 	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevsend.o udev_lib.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
 	$(STRIPCMD) $@
 
-$(STARTER): $(STARTER).o $(HEADERS) $(LIBC)
-	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevstart.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
-	$(STRIPCMD) $@
-
 $(RULER): $(RULER).o $(OBJS) $(HEADERS) $(LIBC)
 	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevruler.o udev_lib.o udev_config.o udevdb.o $(SYSFS) $(TDB) $(LIB_OBJS) $(ARCH_LIB_OBJS) -lnewt
 	$(STRIPCMD) $@
@@ -292,7 +288,7 @@ $(RULER): $(RULER).o $(OBJS) $(HEADERS) $(LIBC)
 clean:
 	-find . \( -not -type d \) -and \( -name '*~' -o -name '*.[oas]' \) -type f -print \
 	 | xargs rm -f 
-	-rm -f core $(ROOT) $(GEN_HEADERS) $(GEN_CONFIGS) $(GEN_MANPAGES) $(INFO) $(DAEMON) $(SENDER) $(TESTER) $(STARTER) $(RULER)
+	-rm -f core $(ROOT) $(GEN_HEADERS) $(GEN_CONFIGS) $(GEN_MANPAGES) $(INFO) $(DAEMON) $(SENDER) $(TESTER) $(RULER)
 	$(MAKE) -C klibc clean
 	@extras="$(EXTRAS)" ; for target in $$extras ; do \
 		echo $$target ; \
@@ -392,7 +388,7 @@ install: install-initscript install-config install-man install-dev.d all
 	$(INSTALL_PROGRAM) -D $(SENDER) $(DESTDIR)$(sbindir)/$(SENDER)
 	$(INSTALL_PROGRAM) -D $(INFO) $(DESTDIR)$(usrbindir)/$(INFO)
 	$(INSTALL_PROGRAM) -D $(TESTER) $(DESTDIR)$(usrbindir)/$(TESTER)
-	$(INSTALL_PROGRAM) -D $(STARTER) $(DESTDIR)$(sbindir)/$(STARTER)
+	ln -sf $(sbindir)/udev $(DESTDIR)$(sbindir)/$(STARTER)
 	- ln -f -s $(sbindir)/$(SENDER) $(DESTDIR)$(hotplugdir)/$(ROOT).hotplug
 ifndef DESTDIR
 	- killall udevd
diff --git a/dev_d.c b/dev_d.c
index 97c552647b..1ad599ead5 100644
--- a/dev_d.c
+++ b/dev_d.c
@@ -61,7 +61,7 @@ static int run_program(char *name)
  * 	subsystem/
  * 	default/
  */
-void dev_d_send(struct udevice *dev, char *subsystem, char *devpath)
+void dev_d_send(struct udevice *dev, const char *subsystem, const char *devpath)
 {
 	char dirname[256];
 	char env_devname[NAME_SIZE];
diff --git a/udev-add.c b/udev-add.c
index 900e4795aa..1f69329788 100644
--- a/udev-add.c
+++ b/udev-add.c
@@ -316,7 +316,7 @@ error:
 	return -1;
 }
 
-static struct sysfs_class_device *get_class_dev(char *device_name)
+static struct sysfs_class_device *get_class_dev(const char *device_name)
 {
 	char dev_path[SYSFS_PATH_MAX];
 	struct sysfs_class_device *class_dev = NULL;
@@ -341,7 +341,7 @@ exit:
  * If it doesn't happen in about 10 seconds, give up.
  */
 #define SECONDS_TO_WAIT_FOR_FILE	10
-static int sleep_for_file(char *path, char* file)
+static int sleep_for_file(const char *path, char* file)
 {
 	char filename[SYSFS_PATH_MAX + 6];
 	int loop = SECONDS_TO_WAIT_FOR_FILE;
@@ -395,7 +395,7 @@ static int rename_net_if(struct udevice *dev, int fake)
 	return retval;
 }
 
-int udev_add_device(char *path, char *subsystem, int fake)
+int udev_add_device(const char *path, const char *subsystem, int fake)
 {
 	struct sysfs_class_device *class_dev;
 	struct udevice dev;
diff --git a/udev-remove.c b/udev-remove.c
index 4f2cd479c0..7ad7c2402a 100644
--- a/udev-remove.c
+++ b/udev-remove.c
@@ -159,7 +159,7 @@ static int delete_node(struct udevice *dev)
  * something different from the kernel name.  If we have, us it.  If not, use
  * the default kernel name for lack of anything else to know to do.
  */
-int udev_remove_device(char *path, char *subsystem)
+int udev_remove_device(const char *path, const char *subsystem)
 {
 	struct udevice dev;
 	char *temp;
diff --git a/udev.c b/udev.c
index cc6ce10542..0ef4cf8657 100644
--- a/udev.c
+++ b/udev.c
@@ -40,6 +40,9 @@
 char **main_argv;
 char **main_envp;
 
+/* local variables */
+static int is_udevstart;
+
 #ifdef LOG
 unsigned char logname[LOGNAME_SIZE];
 void log_message(int level, const char *format, ...)
@@ -76,27 +79,13 @@ static char *subsystem_blacklist[] = {
 	""
 };
 
-static int udev_hotplug(void)
+int __udev_hotplug(char *action, const char *devpath, const char *subsystem)
 {
-	char *action;
-	char *devpath;
-	char *subsystem;
 	int retval = -EINVAL;
 	int i;
 	struct sigaction act;
 	const int nofake = 0;
 
-	action = get_action();
-	if (!action) {
-		dbg("no action?");
-		goto exit;
-	}
-
-	devpath = get_devpath();
-	if (!devpath) {
-		dbg("no devpath?");
-		goto exit;
-	}
 	dbg("looking at '%s'", devpath);
 
 	/* we only care about class devices and block stuff */
@@ -106,12 +95,6 @@ static int udev_hotplug(void)
 		goto exit;
 	}
 
-	/* skip blacklisted subsystems */
-	subsystem = get_subsystem(main_argv[1]);
-	if (!subsystem) {
-		dbg("no subsystem?");
-		goto exit;
-	}
 	i = 0;
 	while (subsystem_blacklist[i][0] != '\0') {
 		if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
@@ -136,7 +119,9 @@ static int udev_hotplug(void)
 	sigaction(SIGTERM, &act, NULL);
 
 	if (strcmp(action, "add") == 0) {
-		namedev_init();
+		/* Already done. */
+		if (!is_udevstart)
+			namedev_init();
 		retval = udev_add_device(devpath, subsystem, nofake);
 		goto action_done;
 	}
@@ -156,17 +141,50 @@ exit:
 	return retval;
 }
 
+static int udev_hotplug(void)
+{
+	char *action;
+	char *devpath;
+	char *subsystem;
+
+	action = get_action();
+	if (!action) {
+		dbg("no action?");
+		return -EINVAL;
+	}
+
+	devpath = get_devpath();
+	if (!devpath) {
+		dbg("no devpath?");
+		return -EINVAL;
+	}
+
+	/* skip blacklisted subsystems */
+	subsystem = get_subsystem(main_argv[1]);
+	if (!subsystem) {
+		dbg("no subsystem?");
+		return -EINVAL;
+	}
+
+	return __udev_hotplug(action, devpath, subsystem);
+}
+
 int main(int argc, char *argv[], char *envp[])
 {
 	main_argv = argv;
 	main_envp = envp;
 
-	init_logging("udev");
+	if (strstr(argv[0], "udevstart"))
+		is_udevstart = 1;
 
 	/* initialize our configuration */
 	udev_init_config();
 
 	dbg("version %s", UDEV_VERSION);
 
-	return udev_hotplug();
+	if (is_udevstart) {
+		namedev_init();
+		return udev_start();
+	} else
+		return udev_hotplug();
 }
diff --git a/udev.h b/udev.h
index da02e26bba..310154f55d 100644
--- a/udev.h
+++ b/udev.h
@@ -61,11 +61,15 @@ struct udevice {
 	char kernel_name[NAME_SIZE];
 };
 
-extern int udev_add_device(char *path, char *subsystem, int fake);
-extern int udev_remove_device(char *path, char *subsystem);
+extern int udev_add_device(const char *path, const char *subsystem, int fake);
+extern int udev_remove_device(const char *path, const char *subsystem);
 extern void udev_init_config(void);
+extern int udev_start(void);
+extern int __udev_hotplug(char *action, const char *devpath,
+	const char *subsystem);
 extern int parse_get_pair(char **orig_string, char **left, char **right);
-extern void dev_d_send(struct udevice *dev, char *subsystem, char *devpath);
+extern void dev_d_send(struct udevice *dev, const char *subsystem,
+	const char *devpath);
 
 extern char **main_argv;
 extern char **main_envp;
diff --git a/udevstart.c b/udevstart.c
index 3ecfd4cb61..d94c9501c9 100644
--- a/udevstart.c
+++ b/udevstart.c
@@ -36,25 +36,12 @@
 #include "logging.h"
 #include "udev_lib.h"
 #include "list.h"
-
-
-#ifdef LOG
-unsigned char logname[LOGNAME_SIZE];
-void log_message(int level, const char *format, ...)
-{
-	va_list args;
-
-	va_start(args, format);
-	vsyslog(level, format, args);
-	va_end(args);
-}
-#endif
+#include "udev.h"
 
 
 #define MAX_PATHLEN		1024
 #define SYSBLOCK		"/sys/block"
 #define SYSCLASS		"/sys/class"
-#define UDEV_BIN		"/sbin/udev"
 
 struct device {
 	struct list_head list;
@@ -88,28 +75,13 @@ static int device_list_insert(char *path, char *subsystem, struct list_head *dev
 
 static void udev_exec(const char *path, const char* subsystem)
 {
-	pid_t pid;
-	char action[] = "ACTION=add";
-	char devpath[MAX_PATHLEN];
-	char nosleep[] = "UDEV_NO_SLEEP=1";
-	char *env[] = { action, devpath, nosleep, NULL };
-
-	strcpy(devpath, "DEVPATH=");
-	strfieldcat(devpath, path);
-
-	pid = fork();
-	switch (pid) {
-	case 0:
-		/* child */
-		execle(UDEV_BIN, "udev", subsystem, NULL, env);
-		dbg("exec of child failed");
+	/* Setup env variables. */
+	setenv("UDEV_NO_SLEEP", "1", 1);
+
+	/* Now call __udev_hotplug(). */
+	if (__udev_hotplug("add", path, subsystem)) {
+		dbg("Calling of udev_hotplug failed");
 		exit(1);
-		break;
-	case -1:
-		dbg("fork of child failed");
-		break;
-	default:
-		wait(NULL);
 	}
 }
 
@@ -267,12 +239,9 @@ static void udev_scan_class(void)
 	exec_list(&device_list);
 }
 
-int main(int argc, char *argv[], char *envp[])
+int udev_start(void)
 {
-	init_logging("udevstart");
-
 	udev_scan_class();
 	udev_scan_block();
-
 	return 0;
 }