[PATCH] don't wait for sysfs if the kernel(2.6.10-rc2) tells us what not to expect

Newer kernels will tell us if we should wait for the "device" or
the "bus" link. So don't waste the time with our lists or wait
for the timeout.

1 files changed, 38 insertions, 25 deletions

diff --git a/udev_sysfs.c b/udev_sysfs.c
index a11c430d..1953dd77 100644
--- a/udev_sysfs.c
+++ b/udev_sysfs.c
@@ -28,14 +28,13 @@
 #include <errno.h>
 #include <sys/stat.h>
 
-#include "logging.h"
+#include "libsysfs/sysfs/libsysfs.h"
 #include "udev_version.h"
 #include "udev_sysfs.h"
-#include "libsysfs/sysfs/libsysfs.h"
+#include "udev_lib.h"
+#include "logging.h"
 
-/* list of subsystem specific files
- * NULL if there is no file to wait for
- */
+/* list of subsystem specific files, NULL if there is no file to wait for */
 static struct subsystem_file {
 	char *subsystem;
 	char *file;
@@ -204,6 +203,13 @@ static int class_device_expect_no_device_link(struct sysfs_class_device *class_d
 	struct class_device *classdevice;
 	int len;
 
+	/* the kernel may tell us what to wait for */
+	if (kernel_release_satisfactory(2,6,10) > 0)
+		if (getenv("PHYSDEVPATH") == NULL) {
+			dbg("the kernel says, that there is no physical device for '%s'", class_dev->path);
+			return 1;
+		}
+
 	for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
 		if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
 			/* see if no device in this class is expected to have a device-link */
@@ -229,7 +235,7 @@ static int class_device_expect_no_device_link(struct sysfs_class_device *class_d
 	return 0;
 }
 
-/* skip waiting for the bus */
+/* skip waiting for the bus of the devices device */
 static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
 {
 	static char *devices_without_bus[] = {
@@ -250,14 +256,14 @@ static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
 	return 0;
 }
 
-/* wait for the bus and for a bus specific file to show up */
-int wait_for_bus_device(struct sysfs_device *devices_dev,
+/* wait for a devices device specific file to show up */
+int wait_for_devices_device(struct sysfs_device *devices_dev,
 			const char **error)
 {
-	static struct bus_file {
+	static struct device_file {
 		char *bus;
 		char *file;
-	} bus_files[] = {
+	} device_files[] = {
 		{ .bus = "scsi",	.file = "vendor" },
 		{ .bus = "usb",		.file = "idVendor" },
 		{ .bus = "usb",		.file = "iInterface" },
@@ -272,9 +278,16 @@ int wait_for_bus_device(struct sysfs_device *devices_dev,
 		{ .bus = "ieee1394",	.file = "address" },
 		{ NULL, NULL }
 	};
-	struct bus_file *busfile;
+	struct device_file *devicefile;
 	int loop;
 
+	/* the kernel may tell us what to wait for */
+	if (kernel_release_satisfactory(2,6,10) > 0)
+		if (getenv("PHYSDEVBUS") == NULL) {
+			dbg("the kernel says, that there is no bus for '%s'", devices_dev->path);
+			return 0;
+		}
+
 	/* wait for the bus device link to the devices device */
 	loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 	while (--loop) {
@@ -291,22 +304,22 @@ int wait_for_bus_device(struct sysfs_device *devices_dev,
 	}
 	dbg("bus device link found for bus '%s'", devices_dev->bus);
 
-	/* wait for a bus specific file to show up */
+	/* wait for a bus device specific file to show up */
 	loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
 	while (--loop) {
 		int found_bus_type = 0;
 
-		for (busfile = bus_files; busfile->bus != NULL; busfile++) {
-			if (strcmp(devices_dev->bus, busfile->bus) == 0) {
+		for (devicefile = device_files; devicefile->bus != NULL; devicefile++) {
+			if (strcmp(devices_dev->bus, devicefile->bus) == 0) {
 				char filename[SYSFS_PATH_MAX];
 				struct stat stats;
 
 				found_bus_type = 1;
-				snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", devices_dev->path, busfile->file);
-				dbg("looking at bus '%s' for specific file '%s'", devices_dev->bus, filename);
+				snprintf(filename, SYSFS_PATH_MAX-1, "%s/%s", devices_dev->path, devicefile->file);
+				dbg("looking at bus '%s' device for specific file '%s'", devices_dev->bus, filename);
 
 				if (stat(filename, &stats) == 0) {
-					dbg("bus '%s' specific file '%s' found", devices_dev->bus, busfile->file);
+					dbg("bus '%s' device specific file '%s' found", devices_dev->bus, devicefile->file);
 					return 0;
 				}
 			}
@@ -321,14 +334,14 @@ int wait_for_bus_device(struct sysfs_device *devices_dev,
 		usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
 	}
 
-	dbg("error: getting bus '%s' specific file '%s'", devices_dev->bus, busfile->file);
+	dbg("error: getting '%s' device specific file '%s'", devices_dev->bus, devicefile->file);
 	if (error)
-		*error = "bus specific file unavailable";
+		*error = "bus device specific file unavailable";
 	return -1;
 }
 
 
-struct sysfs_class_device *open_class_device_wait(const char *path)
+struct sysfs_class_device *wait_class_device_open(const char *path)
 {
 	struct sysfs_class_device *class_dev;
 	int loop;
@@ -358,7 +371,7 @@ int wait_for_class_device(struct sysfs_class_device *class_dev,
 	/* skip devices without devices-link */
 	if (class_device_expect_no_device_link(class_dev)) {
 		dbg("no device symlink expected for '%s', ", class_dev->name);
-		return -ENODEV;
+		return 0;
 	}
 
 	/* the symlink may be on the parent device */
@@ -388,16 +401,16 @@ int wait_for_class_device(struct sysfs_class_device *class_dev,
 	}
 	dbg("device symlink found pointing to '%s'", devices_dev->path);
 
-	/* wait for the bus value */
+	/* wait for the devices device */
 	if (class_device_expect_no_bus(class_dev)) {
 		dbg("no bus device expected for '%s', ", class_dev->classname);
 		return 0;
-	} else {
-		return wait_for_bus_device(devices_dev, error);
 	}
+
+	return wait_for_devices_device(devices_dev, error);
 }
 
-struct sysfs_device *open_devices_device_wait(const char *path)
+struct sysfs_device *wait_devices_device_open(const char *path)
 {
 	struct sysfs_device *devices_dev;
 	int loop;