libudev-device: fix lazy loading of devlinks, properties and tags

If the underlying device has not read in the properties yet, the generation will be 0, so
make sure we trigger the reading at least once.

2 files changed, 12 insertions, 3 deletions

diff --git a/src/libudev/libudev-device-internal.h b/src/libudev/libudev-device-internal.h
index 3f93fda545..aa36b8cb12 100644
--- a/src/libudev/libudev-device-internal.h
+++ b/src/libudev/libudev-device-internal.h
@@ -47,6 +47,9 @@ struct udev_device {
         uint64_t tags_generation;
         struct udev_list devlinks;
         uint64_t devlinks_generation;
+        bool properties_read:1;
+        bool tags_read:1;
+        bool devlinks_read:1;
         struct udev_list sysattrs;
         bool sysattrs_read;
 };
diff --git a/src/libudev/libudev-device.c b/src/libudev/libudev-device.c
index a55cd258f4..893d72c19f 100644
--- a/src/libudev/libudev-device.c
+++ b/src/libudev/libudev-device.c
@@ -700,7 +700,8 @@ _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev
 {
         assert_return_errno(udev_device, NULL, EINVAL);
 
-        if (device_get_devlinks_generation(udev_device->device) != udev_device->devlinks_generation) {
+        if (device_get_devlinks_generation(udev_device->device) != udev_device->devlinks_generation ||
+            !udev_device->devlinks_read) {
                 const char *devlink;
 
                 udev_list_cleanup(&udev_device->devlinks);
@@ -708,6 +709,7 @@ _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev
                 FOREACH_DEVICE_DEVLINK(udev_device->device, devlink)
                         udev_list_entry_add(&udev_device->devlinks, devlink, NULL);
 
+                udev_device->devlinks_read = true;
                 udev_device->devlinks_generation = device_get_devlinks_generation(udev_device->device);
         }
 
@@ -730,7 +732,8 @@ _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct ud
 {
         assert_return_errno(udev_device, NULL, EINVAL);
 
-        if (device_get_properties_generation(udev_device->device) != udev_device->properties_generation) {
+        if (device_get_properties_generation(udev_device->device) != udev_device->properties_generation ||
+            !udev_device->properties_read) {
                 const char *key, *value;
 
                 udev_list_cleanup(&udev_device->properties);
@@ -738,6 +741,7 @@ _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct ud
                 FOREACH_DEVICE_PROPERTY(udev_device->device, key, value)
                         udev_list_entry_add(&udev_device->properties, key, value);
 
+                udev_device->properties_read = true;
                 udev_device->properties_generation = device_get_properties_generation(udev_device->device);
         }
 
@@ -918,7 +922,8 @@ _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_dev
 {
         assert_return_errno(udev_device, NULL, EINVAL);
 
-        if (device_get_tags_generation(udev_device->device) != udev_device->tags_generation) {
+        if (device_get_tags_generation(udev_device->device) != udev_device->tags_generation ||
+            !udev_device->tags_read) {
                 const char *tag;
 
                 udev_list_cleanup(&udev_device->tags);
@@ -926,6 +931,7 @@ _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_dev
                 FOREACH_DEVICE_TAG(udev_device->device, tag)
                         udev_list_entry_add(&udev_device->tags, tag, NULL);
 
+                udev_device->tags_read = true;
                 udev_device->tags_generation = device_get_tags_generation(udev_device->device);
         }