Re: [patch 0/8] Nesting class_device patches that actually work

Kay Sievers
2005-10-13T23:38:18Z

On Wed, Oct 12, 2005 at 07:10:01PM -0700, Greg KH wrote:
> On Wed, Oct 12, 2005 at 07:08:44PM -0700, Greg KH wrote:
> > Ok, finally. Here's a set of _working_ patches that properly implement
> > nesting class_device structures, and the follow-on patches to move the
> > input subsystem to use them. Hotplug and release functions work
> > properly now, and this will let us move /sys/block/ to use class and
> > class_device structures soon.
>
> Oh, Kay, do you have a public patch to udevstart/udev that can handle
> this nested structure? It might be good to have that so people can test
> these in the next -mm.

Sure, here is an still untested hack. Sorry, I'm "busy" at a conference this
week. Anyhow, I still think that we really don't want to nest classes this way. :)

Thanks,
Kay

---
diff --git a/libsysfs/sysfs_class.c b/libsysfs/sysfs_class.c
index edf751b..e95c919 100644
--- a/libsysfs/sysfs_class.c
+++ b/libsysfs/sysfs_class.c
@@ -227,16 +227,46 @@ struct sysfs_class_device *sysfs_get_cla
if (clsdev->parent)
return (clsdev->parent);

- /*
- * As of now, only block devices have a parent child heirarchy in sysfs
- * We do not know, if, in the future, more classes will have a similar
- * structure. Hence, we now call a specialized function for block and
- * later we can add support functions for other subsystems as required.
- */
- if (!(strncmp(clsdev->classname, SYSFS_BLOCK_NAME,
- sizeof(SYSFS_BLOCK_NAME)))) {
- if ((get_blockdev_parent(clsdev)) == 0)
+ if (!strncmp(clsdev->classname, SYSFS_BLOCK_NAME, sizeof(SYSFS_BLOCK_NAME))) {
+ if ((get_blockdev_parent(clsdev)) == 0)
return (clsdev->parent);
+ } else if (!strncmp(clsdev->classname, SYSFS_CLASS_NAME, sizeof(SYSFS_CLASS_NAME))) {
+ char ppath[SYSFS_PATH_MAX];
+ char dpath[SYSFS_PATH_MAX];
+ char *tmp;
+
+ memset(ppath, 0, SYSFS_PATH_MAX);
+ memset(dpath, 0, SYSFS_PATH_MAX);
+ safestrcpy(ppath, clsdev->path);
+ tmp = strrchr(ppath, '/');
+ if (!tmp) {
+ dprintf("Invalid path to device %s\n", ppath);
+ return NULL;
+ }
+ if (*(tmp + 1) == '\0') {
+ *tmp = '\0';
+ tmp = strrchr(tmp, '/');
+ if (tmp == NULL) {
+ dprintf("Invalid path to device %s\n", ppath);
+ return NULL;
+ }
+ }
+ *tmp = '\0';
+
+ /* Make sure we're not at the top of the device tree */
+ sysfs_get_mnt_path(dpath, SYSFS_PATH_MAX);
+ safestrcat(dpath, "/" SYSFS_CLASS_NAME);
+ if (strcmp(dpath, ppath) == 0) {
+ dprintf("Device at %s does not have a parent\n", clsdev->path);
+ return NULL;
+ }
+
+ clsdev->parent = sysfs_open_class_device_path(ppath);
+ if (!clsdev->parent) {
+ dprintf("Error opening device %s's parent at %s\n", clsdev->name, ppath);
+ return NULL;
+ }
+ return (clsdev->parent);
}
return NULL;
}
diff --git a/udevstart.c b/udevstart.c
index ce96f38..09f0e5d 100644
--- a/udevstart.c
+++ b/udevstart.c
@@ -79,7 +79,7 @@ static int device_list_insert(const char
struct device *new_device;
const char *devpath = &path[strlen(sysfs_path)];

- dbg("insert: '%s'\n", devpath);
+ dbg("insert: '%s'", devpath);

list_for_each_entry(loop_device, device_list, node) {
if (strcmp(loop_device->path, devpath) > 0) {
@@ -296,7 +296,6 @@ static void udev_scan_class(struct list_
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
char dirname[PATH_SIZE];
DIR *dir2;
- struct dirent *dent2;

if (dent->d_name[0] == '.')
continue;
@@ -306,6 +305,9 @@ static void udev_scan_class(struct list_

dir2 = opendir(dirname);
if (dir2 != NULL) {
+ DIR *dir3;
+ struct dirent *dent2;
+
for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
char dirname2[PATH_SIZE];

@@ -317,6 +319,25 @@ static void udev_scan_class(struct list_

if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
device_list_insert(dirname2, dent->d_name, device_list);
+
+ dir3 = opendir(dirname2);
+ if (dir3 != NULL) {
+ struct dirent *dent3;
+
+ for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
+ char dirname3[PATH_SIZE];
+
+ if (dent3->d_name[0] == '.')
+ continue;
+
+ snprintf(dirname3, sizeof(dirname3), "%s/%s", dirname2, dent3->d_name);
+ dirname3[sizeof(dirname3)-1] = '\0';
+
+ if (has_devt(dirname3))
+ device_list_insert(dirname3, dent->d_name, device_list);
+ }
+ closedir(dir3);
+ }
}
closedir(dir2);
}