diff --git a/src/analyze/analyze-chid.c b/src/analyze/analyze-chid.c
index 6d2c74345f..e691a7d9a5 100644
--- a/src/analyze/analyze-chid.c
+++ b/src/analyze/analyze-chid.c
@@ -361,7 +361,10 @@ int verb_chid(int argc, char *argv[], void *userdata) {
                 if (r < 0)
                         return log_error_errno(r, "Failed to open device %s: %m", arg_drm_device_path);
 
-                if (!device_in_subsystem(drm_dev, "drm"))
+                r = device_in_subsystem(drm_dev, "drm");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to check if the device is a DRM device: %m");
+                if (r == 0)
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot read EDID from a non-DRM device '%s'", arg_drm_device_path);
 
                 r = edid_parse(drm_dev, &smbios_fields[CHID_EDID_PANEL]);
diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index a39398a638..0fa5209305 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -8,6 +8,7 @@
 
 #include "alloc-util.h"
 #include "argv-util.h"
+#include "device-private.h"
 #include "device-util.h"
 #include "escape.h"
 #include "fileio.h"
@@ -92,53 +93,65 @@ static int has_multiple_graphics_cards(void) {
 }
 
 static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
-        sd_device *parent;
-        const char *s;
         int r;
 
         assert(device);
         assert(ret);
 
-        r = sd_device_get_parent(device, &parent);
-        if (r < 0)
-                return r;
-
-        if (device_in_subsystem(parent, "drm")) {
-
-                r = sd_device_get_sysname(parent, &s);
+        for (;;) {
+                r = sd_device_get_parent(device, &device);
                 if (r < 0)
                         return r;
 
-                s = startswith(s, "card");
-                if (!s)
-                        return -ENODATA;
-
-                s += strspn(s, DIGITS);
-                if (*s == '-' && !STARTSWITH_SET(s, "-LVDS-", "-Embedded DisplayPort-", "-eDP-"))
-                        /* A connector DRM device, let's ignore all but LVDS and eDP! */
-                        return -EOPNOTSUPP;
-
-        } else if (device_in_subsystem(parent, "pci") &&
-                   sd_device_get_sysattr_value(parent, "class", &s)) {
-
-                unsigned long class;
-
-                r = safe_atolu(s, &class);
+                r = device_in_subsystem(device, "drm");
                 if (r < 0)
-                        return log_device_warning_errno(parent, r, "Cannot parse PCI class '%s': %m", s);
+                        return r;
+                if (r > 0) {
+                        const char *s;
 
-                /* Graphics card */
-                if (class == PCI_CLASS_GRAPHICS_CARD) {
-                        *ret = parent;
-                        return 0;
+                        r = device_sysname_startswith_strv(device, STRV_MAKE("card"), &s);
+                        if (r < 0)
+                                return r;
+                        if (r == 0)
+                                return -ENODATA;
+
+                        s += strspn(s, DIGITS);
+                        if (*s == '-' && !STARTSWITH_SET(s, "-LVDS-", "-Embedded DisplayPort-", "-eDP-"))
+                                /* A connector DRM device, let's ignore all but LVDS and eDP! */
+                                return -EOPNOTSUPP;
+
+                        continue;
                 }
 
-        } else if (device_in_subsystem(parent, "platform")) {
-                *ret = parent;
-                return 0;
-        }
+                r = device_in_subsystem(device, "pci");
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        uint32_t class;
 
-        return find_pci_or_platform_parent(parent, ret);
+                        r = device_get_sysattr_u32(device, "class", &class);
+                        if (r == -ENOENT)
+                                continue;
+                        if (r < 0)
+                                return r;
+
+                        /* Graphics card */
+                        if (class == PCI_CLASS_GRAPHICS_CARD) {
+                                *ret = device;
+                                return 0;
+                        }
+
+                        continue;
+                }
+
+                r = device_in_subsystem(device, "platform");
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        *ret = device;
+                        return 0;
+                }
+        }
 }
 
 static int same_device(sd_device *a, sd_device *b) {
@@ -191,7 +204,10 @@ static int validate_device(sd_device *device) {
         if (r < 0)
                 return log_device_debug_errno(device, r, "Failed to get sysname: %m");
 
-        if (!device_in_subsystem(device, "backlight"))
+        r = device_in_subsystem(device, "leds");
+        if (r < 0)
+                return log_device_debug_errno(device, r, "Failed to check if device is in backlight subsystem: %m");
+        if (r > 0)
                 return true; /* We assume LED device is always valid. */
 
         r = sd_device_get_sysattr_value(device, "type", &v);
@@ -236,7 +252,7 @@ static int validate_device(sd_device *device) {
         if (r < 0)
                 return log_debug_errno(r, "Failed to add sysattr match: %m");
 
-        if (device_in_subsystem(parent, "pci")) {
+        if (device_in_subsystem(parent, "pci") > 0) {
                 r = has_multiple_graphics_cards();
                 if (r < 0)
                         return log_debug_errno(r, "Failed to check if the system has multiple graphics cards: %m");
@@ -278,7 +294,7 @@ static int validate_device(sd_device *device) {
                         return false;
                 }
 
-                if (device_in_subsystem(other_parent, "platform") && device_in_subsystem(parent, "pci")) {
+                if (device_in_subsystem(other_parent, "platform") > 0 && device_in_subsystem(parent, "pci") > 0) {
                         /* The other is connected to the platform bus and we are a PCI device, that also means we are out. */
                         if (DEBUG_LOGGING) {
                                 const char *other_sysname = NULL, *other_type = NULL;
@@ -298,19 +314,14 @@ static int validate_device(sd_device *device) {
 
 static int read_max_brightness(sd_device *device, unsigned *ret) {
         unsigned max_brightness;
-        const char *s;
         int r;
 
         assert(device);
         assert(ret);
 
-        r = sd_device_get_sysattr_value(device, "max_brightness", &s);
+        r = device_get_sysattr_unsigned(device, "max_brightness", &max_brightness);
         if (r < 0)
-                return log_device_warning_errno(device, r, "Failed to read 'max_brightness' attribute: %m");
-
-        r = safe_atou(s, &max_brightness);
-        if (r < 0)
-                return log_device_warning_errno(device, r, "Failed to parse 'max_brightness' \"%s\": %m", s);
+                return log_device_warning_errno(device, r, "Failed to read/parse 'max_brightness' attribute: %m");
 
         /* If max_brightness is 0, then there is no actual backlight device. This happens on desktops
          * with Asus mainboards that load the eeepc-wmi module. */
@@ -334,6 +345,7 @@ static int clamp_brightness(
                 unsigned *brightness) {
 
         unsigned new_brightness, min_brightness;
+        int r;
 
         assert(device);
         assert(brightness);
@@ -344,7 +356,10 @@ static int clamp_brightness(
          * state restoration. */
 
         min_brightness = (unsigned) ((double) max_brightness * percent / 100);
-        if (device_in_subsystem(device, "backlight"))
+        r = device_in_subsystem(device, "backlight");
+        if (r < 0)
+                return r;
+        if (r > 0)
                 min_brightness = MAX(1U, min_brightness);
 
         new_brightness = CLAMP(*brightness, min_brightness, max_brightness);
@@ -360,7 +375,7 @@ static int clamp_brightness(
         return 0;
 }
 
-static bool shall_clamp(sd_device *device, unsigned *ret) {
+static int shall_clamp(sd_device *device, unsigned *ret) {
         const char *property, *s;
         unsigned default_percent;
         int r;
@@ -368,7 +383,10 @@ static bool shall_clamp(sd_device *device, unsigned *ret) {
         assert(device);
         assert(ret);
 
-        if (device_in_subsystem(device, "backlight")) {
+        r = device_in_subsystem(device, "backlight");
+        if (r < 0)
+                return r;
+        if (r > 0) {
                 property = "ID_BACKLIGHT_CLAMP";
                 default_percent = 5;
         } else {
@@ -560,7 +578,10 @@ static int verb_load(int argc, char *argv[], void *userdata) {
         if (validate_device(device) == 0)
                 return 0;
 
-        clamp = shall_clamp(device, &percent);
+        r = shall_clamp(device, &percent);
+        if (r < 0)
+                return r;
+        clamp = r;
 
         r = read_saved_brightness(device, &brightness);
         if (r < 0) {
diff --git a/src/dissect/dissect.c b/src/dissect/dissect.c
index 09cc90cf02..5db462f4ff 100644
--- a/src/dissect/dissect.c
+++ b/src/dissect/dissect.c
@@ -2084,8 +2084,13 @@ static int action_detach(const char *path) {
                 FOREACH_DEVICE(e, d) {
                         _cleanup_(loop_device_unrefp) LoopDevice *entry_loop = NULL;
 
-                        if (!device_is_devtype(d, "disk")) /* Filter out partition block devices */
+                        r = device_is_devtype(d, "disk");
+                        if (r < 0) {
+                                log_device_warning_errno(d, r, "Failed to check if device is a whole disk, skipping: %m");
                                 continue;
+                        }
+                        if (r == 0)
+                                continue; /* Filter out partition block devices */
 
                         r = loop_device_open(d, O_RDONLY, LOCK_SH, &entry_loop);
                         if (r < 0) {
diff --git a/src/home/homed-home.c b/src/home/homed-home.c
index da5e304f1b..58a8ffff83 100644
--- a/src/home/homed-home.c
+++ b/src/home/homed-home.c
@@ -9,6 +9,7 @@
 #include "build-path.h"
 #include "bus-common-errors.h"
 #include "bus-locator.h"
+#include "device-util.h"
 #include "env-util.h"
 #include "errno-list.h"
 #include "errno-util.h"
@@ -3206,10 +3207,8 @@ static int home_get_image_path_seat(Home *h, char **ret) {
         if (r < 0)
                 return r;
 
-        r = sd_device_get_property_value(d, "ID_SEAT", &seat);
-        if (r == -ENOENT) /* no property means seat0 */
-                seat = "seat0";
-        else if (r < 0)
+        r = device_get_seat(d, &seat);
+        if (r < 0)
                 return r;
 
         return strdup_to(ret, seat);
diff --git a/src/libsystemd/sd-device/device-enumerator.c b/src/libsystemd/sd-device/device-enumerator.c
index d2faff4ae3..8230763ddd 100644
--- a/src/libsystemd/sd-device/device-enumerator.c
+++ b/src/libsystemd/sd-device/device-enumerator.c
@@ -394,7 +394,10 @@ static int enumerator_sort_devices(sd_device_enumerator *enumerator) {
                         HASHMAP_FOREACH_KEY(device, syspath, enumerator->devices_by_syspath) {
                                 _cleanup_free_ char *p = NULL;
 
-                                if (!device_in_subsystem(device, *prioritized_subsystem))
+                                r = device_in_subsystem(device, *prioritized_subsystem);
+                                if (r < 0)
+                                        return r;
+                                if (r == 0)
                                         continue;
 
                                 devices[n++] = sd_device_ref(device);
diff --git a/src/libsystemd/sd-device/device-monitor.c b/src/libsystemd/sd-device/device-monitor.c
index 992f531be2..99bdc7f342 100644
--- a/src/libsystemd/sd-device/device-monitor.c
+++ b/src/libsystemd/sd-device/device-monitor.c
@@ -471,6 +471,7 @@ DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_device_monitor, sd_device_monitor, devic
 
 static int check_subsystem_filter(sd_device_monitor *m, sd_device *device) {
         const char *s, *d;
+        int r;
 
         assert(m);
         assert(device);
@@ -479,13 +480,9 @@ static int check_subsystem_filter(sd_device_monitor *m, sd_device *device) {
                 return true;
 
         HASHMAP_FOREACH_KEY(d, s, m->subsystem_filter) {
-                if (!device_in_subsystem(device, s))
-                        continue;
-
-                if (d && !device_is_devtype(device, d))
-                        continue;
-
-                return true;
+                r = device_is_subsystem_devtype(device, s, d);
+                if (r != 0)
+                        return r;
         }
 
         return false;
diff --git a/src/libsystemd/sd-device/device-private.c b/src/libsystemd/sd-device/device-private.c
index 3ce87690b3..270e0293e1 100644
--- a/src/libsystemd/sd-device/device-private.c
+++ b/src/libsystemd/sd-device/device-private.c
@@ -441,7 +441,10 @@ static int device_verify(sd_device *device) {
                 return log_device_debug_errno(device, SYNTHETIC_ERRNO(EINVAL),
                                               "sd-device: Device created from strv or nulstr lacks devpath, subsystem, action or seqnum.");
 
-        if (device_in_subsystem(device, "drivers")) {
+        r = device_in_subsystem(device, "drivers");
+        if (r < 0)
+                return log_device_debug_errno(device, r, "sd-device: Failed to check if the device is a driver: %m");
+        if (r > 0) {
                 r = device_set_drivers_subsystem(device);
                 if (r < 0)
                         return log_device_debug_errno(device, r,
diff --git a/src/libsystemd/sd-device/device-util.c b/src/libsystemd/sd-device/device-util.c
index b0475c5ca3..5169c24d84 100644
--- a/src/libsystemd/sd-device/device-util.c
+++ b/src/libsystemd/sd-device/device-util.c
@@ -132,24 +132,80 @@ char** device_make_log_fields(sd_device *device) {
         return TAKE_PTR(strv);
 }
 
-bool device_in_subsystem(sd_device *device, const char *subsystem) {
-        const char *s = NULL;
+int device_in_subsystem_strv(sd_device *device, char * const *subsystems) {
+        const char *s;
+        int r;
 
         assert(device);
 
-        (void) sd_device_get_subsystem(device, &s);
-        return streq_ptr(s, subsystem);
+        r = sd_device_get_subsystem(device, &s);
+        if (r == -ENOENT)
+                return strv_isempty(subsystems);
+        if (r < 0)
+                return r;
+        return strv_contains(subsystems, s);
 }
 
-bool device_is_devtype(sd_device *device, const char *devtype) {
-        const char *s = NULL;
+int device_is_devtype(sd_device *device, const char *devtype) {
+        const char *s;
+        int r;
 
         assert(device);
 
-        (void) sd_device_get_devtype(device, &s);
+        r = sd_device_get_devtype(device, &s);
+        if (r == -ENOENT)
+                return !devtype;
+        if (r < 0)
+                return r;
         return streq_ptr(s, devtype);
 }
 
+int device_is_subsystem_devtype(sd_device *device, const char *subsystem, const char *devtype) {
+        int r;
+
+        assert(device);
+
+        r = device_in_subsystem(device, subsystem);
+        if (r <= 0)
+                return r;
+
+        if (!devtype)
+                return true;
+
+        return device_is_devtype(device, devtype);
+}
+
+int device_sysname_startswith_strv(sd_device *device, char * const *prefixes, const char **ret_suffix) {
+        const char *sysname;
+        int r;
+
+        assert(device);
+
+        r = sd_device_get_sysname(device, &sysname);
+        if (r < 0)
+                return r;
+
+        const char *suffix = startswith_strv(sysname, prefixes);
+        if (ret_suffix)
+                *ret_suffix = suffix;
+        return !!suffix;
+}
+
+int device_get_seat(sd_device *device, const char **ret) {
+        const char *seat = NULL;
+        int r;
+
+        assert(device);
+        assert(ret);
+
+        r = sd_device_get_property_value(device, "ID_SEAT", &seat);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        *ret = isempty(seat) ? "seat0" : seat;
+        return 0;
+}
+
 bool device_property_can_set(const char *property) {
         return property &&
                 !STR_IN_SET(property,
diff --git a/src/libsystemd/sd-device/device-util.h b/src/libsystemd/sd-device/device-util.h
index 0a740ede32..5b899ecfcd 100644
--- a/src/libsystemd/sd-device/device-util.h
+++ b/src/libsystemd/sd-device/device-util.h
@@ -103,7 +103,18 @@ int device_open_from_devnum(mode_t mode, dev_t devnum, int flags, char **ret_dev
 
 char** device_make_log_fields(sd_device *device);
 
-bool device_in_subsystem(sd_device *device, const char *subsystem);
-bool device_is_devtype(sd_device *device, const char *devtype);
+int device_in_subsystem_strv(sd_device *device, char * const *subsystems);
+#define device_in_subsystem(device, ...) \
+        device_in_subsystem_strv(device, STRV_MAKE(__VA_ARGS__))
+
+int device_is_devtype(sd_device *device, const char *devtype);
+
+int device_is_subsystem_devtype(sd_device *device, const char *subsystem, const char *devtype);
+
+int device_get_seat(sd_device *device, const char **ret);
+
+int device_sysname_startswith_strv(sd_device *device, char * const *prefixes, const char **ret_suffix);
+#define device_sysname_startswith(device, ...) \
+        device_sysname_startswith_strv(device, STRV_MAKE(__VA_ARGS__), NULL)
 
 bool device_property_can_set(const char *property) _pure_;
diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index 12763f53b5..37de2b9e60 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -314,7 +314,10 @@ int device_new_from_mode_and_devnum(sd_device **ret, mode_t mode, dev_t devnum)
         if (n != devnum)
                 return -ENXIO;
 
-        if (device_in_subsystem(dev, "block") != !!S_ISBLK(mode))
+        r = device_in_subsystem(dev, "block");
+        if (r < 0)
+                return r;
+        if (r > 0 ? !S_ISBLK(mode) : !S_ISCHR(mode))
                 return -ENXIO;
 
         *ret = TAKE_PTR(dev);
@@ -414,8 +417,9 @@ static int device_new_from_path_join(
                 return r;
 
         /* Check if the found device really has the expected subsystem and sysname, for safety. */
-        if (!device_in_subsystem(new_device, subsystem))
-                return 0;
+        r = device_in_subsystem(new_device, subsystem);
+        if (r <= 0)
+                return r;
 
         const char *new_driver_subsystem = NULL;
         (void) sd_device_get_driver_subsystem(new_device, &new_driver_subsystem);
@@ -843,7 +847,10 @@ int device_read_uevent_file(sd_device *device) {
                                                major, strna(minor));
         }
 
-        if (device_in_subsystem(device, "drivers")) {
+        r = device_in_subsystem(device, "drivers");
+        if (r < 0)
+                log_device_debug_errno(device, r, "Failed to check if the device is a driver, ignoring: %m");
+        if (r > 0) {
                 r = device_set_drivers_subsystem(device);
                 if (r < 0)
                         log_device_debug_errno(device, r,
@@ -1245,9 +1252,14 @@ _public_ int sd_device_get_subsystem(sd_device *device, const char **ret) {
 }
 
 _public_ int sd_device_get_driver_subsystem(sd_device *device, const char **ret) {
+        int r;
+
         assert_return(device, -EINVAL);
 
-        if (!device_in_subsystem(device, "drivers"))
+        r = device_in_subsystem(device, "drivers");
+        if (r < 0)
+                return r;
+        if (r == 0)
                 return -ENOENT;
 
         assert(device->driver_subsystem);
@@ -1287,10 +1299,10 @@ _public_ int sd_device_get_parent_with_subsystem_devtype(sd_device *device, cons
                 if (r < 0)
                         return r;
 
-                if (!device_in_subsystem(device, subsystem))
-                        continue;
-
-                if (devtype && !device_is_devtype(device, devtype))
+                r = device_is_subsystem_devtype(device, subsystem, devtype);
+                if (r < 0)
+                        return r;
+                if (r == 0)
                         continue;
 
                 if (ret)
@@ -1710,15 +1722,20 @@ _public_ int sd_device_get_device_id(sd_device *device, const char **ret) {
                 int ifindex, r;
 
                 if (sd_device_get_devnum(device, &devnum) >= 0) {
+                        r = device_in_subsystem(device, "block");
+                        if (r < 0)
+                                return r;
+                        char t = r > 0 ? 'b' : 'c';
+
                         /* use dev_t — b259:131072, c254:0 */
-                        if (asprintf(&id, "%c" DEVNUM_FORMAT_STR,
-                                     device_in_subsystem(device, "block") ? 'b' : 'c',
-                                     DEVNUM_FORMAT_VAL(devnum)) < 0)
+                        if (asprintf(&id, "%c" DEVNUM_FORMAT_STR, t, DEVNUM_FORMAT_VAL(devnum)) < 0)
                                 return -ENOMEM;
+
                 } else if (sd_device_get_ifindex(device, &ifindex) >= 0) {
                         /* use netdev ifindex — n3 */
                         if (asprintf(&id, "n%u", (unsigned) ifindex) < 0)
                                 return -ENOMEM;
+
                 } else {
                         _cleanup_free_ char *sysname = NULL;
 
@@ -1730,7 +1747,10 @@ _public_ int sd_device_get_device_id(sd_device *device, const char **ret) {
                         if (r == O_DIRECTORY)
                                 return -EINVAL;
 
-                        if (device_in_subsystem(device, "drivers"))
+                        r = device_in_subsystem(device, "drivers");
+                        if (r < 0)
+                                return r;
+                        if (r > 0)
                                 /* the 'drivers' pseudo-subsystem is special, and needs the real
                                  * subsystem encoded as well */
                                 id = strjoin("+drivers:", ASSERT_PTR(device->driver_subsystem), ":", sysname);
@@ -2797,7 +2817,10 @@ _public_ int sd_device_open(sd_device *device, int flags) {
         if (st.st_rdev != devnum)
                 return -ENXIO;
 
-        if (device_in_subsystem(device, "block") ? !S_ISBLK(st.st_mode) : !S_ISCHR(st.st_mode))
+        r = device_in_subsystem(device, "block");
+        if (r < 0)
+                return r;
+        if (r > 0 ? !S_ISBLK(st.st_mode) : !S_ISCHR(st.st_mode))
                 return -ENXIO;
 
         /* If flags has O_PATH, then we cannot check diskseq. Let's return earlier. */
diff --git a/src/libsystemd/sd-device/test-device-util.c b/src/libsystemd/sd-device/test-device-util.c
index f7c9deb45c..aa3fb8215f 100644
--- a/src/libsystemd/sd-device/test-device-util.c
+++ b/src/libsystemd/sd-device/test-device-util.c
@@ -6,79 +6,203 @@
 
 TEST(log_device_full) {
         _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
-        int r;
 
         (void) sd_device_new_from_subsystem_sysname(&dev, "net", "lo");
 
         for (int level = LOG_ERR; level <= LOG_DEBUG; level++) {
                 log_device_full(dev, level, "test level=%d: %m", level);
 
-                r = log_device_full_errno(dev, level, EUCLEAN, "test level=%d errno=EUCLEAN: %m", level);
-                assert_se(r == -EUCLEAN);
-
-                r = log_device_full_errno(dev, level, 0, "test level=%d errno=0: %m", level);
-                assert_se(r == 0);
-
-                r = log_device_full_errno(dev, level, SYNTHETIC_ERRNO(ENODATA), "test level=%d errno=S(ENODATA).", level);
-                assert_se(r == -ENODATA);
+                ASSERT_EQ(log_device_full_errno(dev, level, EUCLEAN, "test level=%d errno=EUCLEAN: %m", level), -EUCLEAN);
+                ASSERT_EQ(log_device_full_errno(dev, level, 0, "test level=%d errno=0: %m", level), 0);
+                ASSERT_EQ(log_device_full_errno(dev, level, SYNTHETIC_ERRNO(ENODATA), "test level=%d errno=S(ENODATA).", level), -ENODATA);
         }
 }
 
-TEST(device_in_subsystem) {
-        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
-        int r;
-
-        r = sd_device_new_from_subsystem_sysname(&dev, "net", "lo");
-        if (r == -ENODEV)
-                return (void) log_tests_skipped("net/lo does not exist");
-        assert_se(r >= 0);
-
-        assert_se(device_in_subsystem(dev, "net"));
-        assert_se(!device_in_subsystem(dev, "disk"));
-        assert_se(!device_in_subsystem(dev, "subsystem"));
-        assert_se(!device_in_subsystem(dev, ""));
-        assert_se(!device_in_subsystem(dev, NULL));
-
-        dev = sd_device_unref(dev);
-
-        assert_se(sd_device_new_from_syspath(&dev, "/sys/class/net") >= 0);
-        assert_se(!device_in_subsystem(dev, "net"));
-        assert_se(!device_in_subsystem(dev, "disk"));
-        assert_se(device_in_subsystem(dev, "subsystem"));
-        assert_se(!device_in_subsystem(dev, ""));
-        assert_se(!device_in_subsystem(dev, NULL));
-
-        dev = sd_device_unref(dev);
-
-        assert_se(sd_device_new_from_syspath(&dev, "/sys/class") >= 0);
-        assert_se(!device_in_subsystem(dev, "net"));
-        assert_se(!device_in_subsystem(dev, "disk"));
-        assert_se(!device_in_subsystem(dev, "subsystem"));
-        assert_se(!device_in_subsystem(dev, ""));
-        assert_se(device_in_subsystem(dev, NULL));
-}
-
-TEST(device_is_devtype) {
+TEST(device_in_subsystem_devtype_sysname_startswith) {
         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
-        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
 
-        assert_se(sd_device_enumerator_new(&e) >= 0);
-        assert_se(sd_device_enumerator_add_match_subsystem(e, "disk", true) >= 0);
+        ASSERT_OK(sd_device_enumerator_new(&e));
+        ASSERT_OK(sd_device_enumerator_allow_uninitialized(e));
+        ASSERT_OK(sd_device_enumerator_add_match_subsystem(e, "block", true));
 
         FOREACH_DEVICE(e, d) {
-                const char *t;
+                ASSERT_OK_ZERO(device_in_subsystem(d, "net"));
+                ASSERT_OK_POSITIVE(device_in_subsystem(d, "block"));
+                ASSERT_OK_ZERO(device_in_subsystem(d, "subsystem"));
+                ASSERT_OK_ZERO(device_in_subsystem(d, "", "net"));
+                ASSERT_OK_POSITIVE(device_in_subsystem(d, "net", "block"));
+                ASSERT_OK_POSITIVE(device_in_subsystem(d, "block", "subsystem"));
+                ASSERT_OK_POSITIVE(device_in_subsystem(d, "block", ""));
+                ASSERT_OK_ZERO(device_in_subsystem(d, ""));
+                ASSERT_OK_ZERO(device_in_subsystem(d, NULL));
 
-                assert_se(sd_device_get_devtype(d, &t) >= 0);
-                assert_se(device_is_devtype(d, t));
-                assert_se(!device_is_devtype(d, "hoge"));
-                assert_se(!device_is_devtype(d, ""));
-                assert_se(!device_is_devtype(d, NULL));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(d, STRV_MAKE("net")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(d, STRV_MAKE("", "net")));
+                ASSERT_OK_POSITIVE(device_in_subsystem_strv(d, STRV_MAKE("net", "block")));
+                ASSERT_OK_POSITIVE(device_in_subsystem_strv(d, STRV_MAKE("block", "subsystem")));
+                ASSERT_OK_POSITIVE(device_in_subsystem_strv(d, STRV_MAKE("block", "")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(d, STRV_MAKE("")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(d, STRV_MAKE(NULL)));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(d, NULL));
+
+                const char *t;
+                ASSERT_OK(sd_device_get_devtype(d, &t));
+                ASSERT_OK_POSITIVE(device_is_devtype(d, t));
+                ASSERT_OK_ZERO(device_is_devtype(d, "hoge"));
+                ASSERT_OK_ZERO(device_is_devtype(d, ""));
+                ASSERT_OK_ZERO(device_is_devtype(d, NULL));
+
+                ASSERT_OK_POSITIVE(device_is_subsystem_devtype(d, "block", t));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "block", "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "block", ""));
+                ASSERT_OK_POSITIVE(device_is_subsystem_devtype(d, "block", NULL));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "net", t));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "net", "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "net", ""));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "net", NULL));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "subsystem", t));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "subsystem", "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "subsystem", ""));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, "subsystem", NULL));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, NULL, t));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, NULL, "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, NULL, ""));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(d, NULL, NULL));
+
+                const char *s;
+                ASSERT_OK(sd_device_get_sysname(d, &s));
+                ASSERT_OK_POSITIVE(device_sysname_startswith(d, s));
+                ASSERT_OK_POSITIVE(device_sysname_startswith(d, CHAR_TO_STR(s[0])));
+                ASSERT_OK_POSITIVE(device_sysname_startswith(d, ""));
+                ASSERT_OK_ZERO(device_sysname_startswith(d, "00"));
         }
 
-        assert_se(sd_device_new_from_syspath(&dev, "/sys/class/net") >= 0);
-        assert_se(!device_is_devtype(dev, "hoge"));
-        assert_se(!device_is_devtype(dev, ""));
-        assert_se(device_is_devtype(dev, NULL));
+        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+
+        if (sd_device_new_from_subsystem_sysname(&dev, "net", "lo") >= 0) {
+                ASSERT_OK_POSITIVE(device_in_subsystem(dev, "net"));
+                ASSERT_OK_ZERO(device_in_subsystem(dev, "block"));
+                ASSERT_OK_ZERO(device_in_subsystem(dev, "subsystem"));
+                ASSERT_OK_POSITIVE(device_in_subsystem(dev, "", "net"));
+                ASSERT_OK_POSITIVE(device_in_subsystem(dev, "net", "block"));
+                ASSERT_OK_ZERO(device_in_subsystem(dev, "block", "subsystem"));
+                ASSERT_OK_ZERO(device_in_subsystem(dev, "block", ""));
+                ASSERT_OK_ZERO(device_in_subsystem(dev, ""));
+                ASSERT_OK_ZERO(device_in_subsystem(dev, NULL));
+
+                ASSERT_OK_POSITIVE(device_in_subsystem_strv(dev, STRV_MAKE("net")));
+                ASSERT_OK_POSITIVE(device_in_subsystem_strv(dev, STRV_MAKE("", "net")));
+                ASSERT_OK_POSITIVE(device_in_subsystem_strv(dev, STRV_MAKE("net", "block")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("block", "subsystem")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("block", "")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("")));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE(NULL)));
+                ASSERT_OK_ZERO(device_in_subsystem_strv(dev, NULL));
+
+                ASSERT_OK_ZERO(device_is_devtype(dev, "hoge"));
+                ASSERT_OK_ZERO(device_is_devtype(dev, ""));
+                ASSERT_OK_POSITIVE(device_is_devtype(dev, NULL));
+
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", ""));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", NULL));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "net", "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "net", ""));
+                ASSERT_OK_POSITIVE(device_is_subsystem_devtype(dev, "net", NULL));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", ""));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", NULL));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, "hoge"));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, ""));
+                ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, NULL));
+
+                ASSERT_OK_POSITIVE(device_sysname_startswith(dev, "lo"));
+                ASSERT_OK_POSITIVE(device_sysname_startswith(dev, "l"));
+                ASSERT_OK_POSITIVE(device_sysname_startswith(dev, ""));
+                ASSERT_OK_ZERO(device_sysname_startswith(dev, "00"));
+
+                dev = sd_device_unref(dev);
+        }
+
+        ASSERT_OK(sd_device_new_from_syspath(&dev, "/sys/class/net"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "net"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "block"));
+        ASSERT_OK_POSITIVE(device_in_subsystem(dev, "subsystem"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "", "net"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "net", "block"));
+        ASSERT_OK_POSITIVE(device_in_subsystem(dev, "block", "subsystem"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "block", ""));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, ""));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, NULL));
+
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("net")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("", "net")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("net", "block")));
+        ASSERT_OK_POSITIVE(device_in_subsystem_strv(dev, STRV_MAKE("block", "subsystem")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("block", "")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE(NULL)));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, NULL));
+
+        ASSERT_OK_ZERO(device_is_devtype(dev, "hoge"));
+        ASSERT_OK_ZERO(device_is_devtype(dev, ""));
+        ASSERT_OK_POSITIVE(device_is_devtype(dev, NULL));
+
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", "hoge"));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", ""));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", NULL));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", "hoge"));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", ""));
+        ASSERT_OK_POSITIVE(device_is_subsystem_devtype(dev, "subsystem", NULL));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, "hoge"));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, ""));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, NULL));
+
+        ASSERT_OK_POSITIVE(device_sysname_startswith(dev, "net"));
+        ASSERT_OK_POSITIVE(device_sysname_startswith(dev, "n"));
+        ASSERT_OK_POSITIVE(device_sysname_startswith(dev, ""));
+        ASSERT_OK_ZERO(device_sysname_startswith(dev, "00"));
+
+        dev = sd_device_unref(dev);
+
+        ASSERT_OK(sd_device_new_from_syspath(&dev, "/sys/class"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "net"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "block"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "subsystem"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "", "net"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "net", "block"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "block", "subsystem"));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, "block", ""));
+        ASSERT_OK_ZERO(device_in_subsystem(dev, ""));
+        ASSERT_OK_POSITIVE(device_in_subsystem(dev, NULL));
+
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("net")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("", "net")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("net", "block")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("block", "subsystem")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("block", "")));
+        ASSERT_OK_ZERO(device_in_subsystem_strv(dev, STRV_MAKE("")));
+        ASSERT_OK_POSITIVE(device_in_subsystem_strv(dev, STRV_MAKE(NULL)));
+        ASSERT_OK_POSITIVE(device_in_subsystem_strv(dev, NULL));
+
+        ASSERT_OK_ZERO(device_is_devtype(dev, "hoge"));
+        ASSERT_OK_ZERO(device_is_devtype(dev, ""));
+        ASSERT_OK_POSITIVE(device_is_devtype(dev, NULL));
+
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", "hoge"));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", ""));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "block", NULL));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", "hoge"));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", ""));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, "subsystem", NULL));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, "hoge"));
+        ASSERT_OK_ZERO(device_is_subsystem_devtype(dev, NULL, ""));
+        ASSERT_OK_POSITIVE(device_is_subsystem_devtype(dev, NULL, NULL));
+
+        ASSERT_OK_POSITIVE(device_sysname_startswith(dev, "class"));
+        ASSERT_OK_POSITIVE(device_sysname_startswith(dev, "c"));
+        ASSERT_OK_POSITIVE(device_sysname_startswith(dev, ""));
+        ASSERT_OK_ZERO(device_sysname_startswith(dev, "00"));
 }
 
 static int intro(void) {
diff --git a/src/libsystemd/sd-device/test-sd-device.c b/src/libsystemd/sd-device/test-sd-device.c
index 2db4f42c74..ff59d3bd50 100644
--- a/src/libsystemd/sd-device/test-sd-device.c
+++ b/src/libsystemd/sd-device/test-sd-device.c
@@ -539,6 +539,7 @@ TEST(sd_device_enumerator_add_match_parent) {
 
 TEST(sd_device_enumerator_add_all_parents) {
         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+        int r;
 
         /* STEP 1: enumerate all block devices without all_parents() */
         ASSERT_OK(sd_device_enumerator_new(&e));
@@ -552,8 +553,7 @@ TEST(sd_device_enumerator_add_all_parents) {
         unsigned devices_count_with_parents = 0;
         unsigned devices_count_without_parents = 0;
         FOREACH_DEVICE(e, dev) {
-                ASSERT_TRUE(device_in_subsystem(dev, "block"));
-                ASSERT_TRUE(device_is_devtype(dev, "partition"));
+                ASSERT_OK_POSITIVE(device_is_subsystem_devtype(dev, "block", "partition"));
                 devices_count_without_parents++;
         }
 
@@ -564,7 +564,8 @@ TEST(sd_device_enumerator_add_all_parents) {
 
         unsigned not_filtered_parent_count = 0;
         FOREACH_DEVICE(e, dev) {
-                if (!device_in_subsystem(dev, "block") || !device_is_devtype(dev, "partition"))
+                ASSERT_OK(r = device_is_subsystem_devtype(dev, "block", "partition"));
+                if (r == 0)
                         not_filtered_parent_count++;
                 devices_count_with_parents++;
         }
diff --git a/src/login/logind-core.c b/src/login/logind-core.c
index 75fd0a2d87..0208c74233 100644
--- a/src/login/logind-core.c
+++ b/src/login/logind-core.c
@@ -289,8 +289,9 @@ int manager_process_seat_device(Manager *m, sd_device *d) {
                 bool master;
                 Seat *seat;
 
-                if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
-                        sn = "seat0";
+                r = device_get_seat(d, &sn);
+                if (r < 0)
+                        return r;
 
                 if (!seat_name_is_valid(sn)) {
                         log_device_warning(d, "Device with invalid seat name %s found, ignoring.", sn);
@@ -352,8 +353,9 @@ int manager_process_button_device(Manager *m, sd_device *d) {
                 if (r < 0)
                         return r;
 
-                if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
-                        sn = "seat0";
+                r = device_get_seat(d, &sn);
+                if (r < 0)
+                        return r;
 
                 button_set_seat(b, sn);
 
@@ -608,7 +610,6 @@ static int manager_count_external_displays(Manager *m) {
                 return r;
 
         FOREACH_DEVICE(e, d) {
-                const char *status, *enabled, *dash, *nn;
                 sd_device *p;
 
                 if (sd_device_get_parent(d, &p) < 0)
@@ -617,17 +618,22 @@ static int manager_count_external_displays(Manager *m) {
                 /* If the parent shares the same subsystem as the
                  * device we are looking at then it is a connector,
                  * which is what we are interested in. */
-                if (!device_in_subsystem(p, "drm"))
+                r = device_in_subsystem(p, "drm");
+                if (r < 0)
+                        return r;
+                if (r == 0)
                         continue;
 
-                if (sd_device_get_sysname(d, &nn) < 0)
-                        continue;
+                const char *nn;
+                r = sd_device_get_sysname(d, &nn);
+                if (r < 0)
+                        return r;
 
                 /* Ignore internal displays: the type is encoded in the sysfs name, as the second dash
                  * separated item (the first is the card name, the last the connector number). We implement a
                  * deny list of external displays here, rather than an allow list of internal ones, to ensure
                  * we don't block suspends too eagerly. */
-                dash = strchr(nn, '-');
+                const char *dash = strchr(nn, '-');
                 if (!dash)
                         continue;
 
@@ -639,12 +645,21 @@ static int manager_count_external_displays(Manager *m) {
                         continue;
 
                 /* Ignore ports that are not enabled */
-                if (sd_device_get_sysattr_value(d, "enabled", &enabled) < 0 || !streq(enabled, "enabled"))
+                const char *enabled;
+                r = sd_device_get_sysattr_value(d, "enabled", &enabled);
+                if (r == -ENOENT)
+                        continue;
+                if (r < 0)
+                        return r;
+                if (!streq(enabled, "enabled"))
                         continue;
 
-                /* We count any connector which is not explicitly
-                 * "disconnected" as connected. */
-                if (sd_device_get_sysattr_value(d, "status", &status) < 0 || !streq(status, "disconnected"))
+                /* We count any connector which is not explicitly "disconnected" as connected. */
+                const char *status = NULL;
+                r = sd_device_get_sysattr_value(d, "status", &status);
+                if (r < 0 && r != -ENOENT)
+                        return r;
+                if (!streq_ptr(status, "disconnected"))
                         n++;
         }
 
diff --git a/src/login/logind-seat.c b/src/login/logind-seat.c
index 2c0905e64d..fb52c5475e 100644
--- a/src/login/logind-seat.c
+++ b/src/login/logind-seat.c
@@ -8,12 +8,13 @@
 #include "sd-messages.h"
 
 #include "alloc-util.h"
-#include "devnode-acl.h"
+#include "device-util.h"
 #include "errno-util.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "format-util.h"
 #include "fs-util.h"
+#include "id128-util.h"
 #include "logind.h"
 #include "logind-device.h"
 #include "logind-seat.h"
@@ -78,6 +79,7 @@ Seat* seat_free(Seat *s) {
 
         hashmap_remove(s->manager->seats, s->id);
 
+        set_free(s->uevents);
         free(s->positions);
         free(s->state_file);
         free(s->id);
@@ -207,19 +209,120 @@ int seat_preallocate_vts(Seat *s) {
         return r;
 }
 
-int seat_apply_acls(Seat *s, Session *old_active) {
+static void seat_triggered_uevents_done(Seat *s) {
+        assert(s);
+
+        if (!set_isempty(s->uevents))
+                return;
+
+        Session *session = s->active;
+
+        if (session) {
+                session_save(session);
+                user_save(session->user);
+        }
+
+        if (session && session->started) {
+                session_send_changed(session, "Active");
+                session_device_resume_all(session);
+        }
+
+        if (!session || session->started)
+                seat_send_changed(s, "ActiveSession");
+}
+
+int manager_process_device_triggered_by_seat(Manager *m, sd_device *dev) {
+        int r;
+
+        assert(m);
+        assert(dev);
+
+        sd_id128_t uuid;
+        r = sd_device_get_trigger_uuid(dev, &uuid);
+        if (IN_SET(r, -ENOENT, -ENODATA))
+                return 0;
+        if (r < 0)
+                return r;
+
+        Seat *s;
+        HASHMAP_FOREACH(s, m->seats)
+                if (set_contains(s->uevents, &uuid))
+                        break;
+        if (!s)
+                return 0;
+
+        free(ASSERT_PTR(set_remove(s->uevents, &uuid)));
+        seat_triggered_uevents_done(s);
+
+        const char *id;
+        r = device_get_seat(dev, &id);
+        if (r < 0)
+                return r;
+
+        if (!streq(id, s->id)) {
+                log_device_debug(dev, "ID_SEAT is changed in the triggered uevent: \"%s\" -> \"%s\"", s->id, id);
+                return 0;
+        }
+
+        return 1; /* The uevent is triggered by the relevant seat. */
+}
+
+static int seat_trigger_devices(Seat *s) {
         int r;
 
         assert(s);
 
-        r = devnode_acl_all(s->id,
-                            false,
-                            !!old_active, old_active ? old_active->user->user_record->uid : 0,
-                            !!s->active, s->active ? s->active->user->user_record->uid : 0);
+        set_clear(s->uevents);
 
+        _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+        r = sd_device_enumerator_new(&e);
         if (r < 0)
-                return log_error_errno(r, "Failed to apply ACLs: %m");
+                return r;
 
+        r = sd_device_enumerator_add_match_tag(e, "uaccess");
+        if (r < 0)
+                return r;
+
+        FOREACH_DEVICE(e, d) {
+                /* Verify that the tag is still in place. */
+                r = sd_device_has_current_tag(d, "uaccess");
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                /* In case people mistag devices without nodes, we need to ignore this. */
+                r = sd_device_get_devname(d, NULL);
+                if (r == -ENOENT)
+                        continue;
+                if (r < 0)
+                        return r;
+
+                const char *id;
+                r = device_get_seat(d, &id);
+                if (r < 0)
+                        return r;
+
+                if (!streq(id, s->id))
+                        continue;
+
+                sd_id128_t uuid;
+                r = sd_device_trigger_with_uuid(d, SD_DEVICE_CHANGE, &uuid);
+                if (r < 0) {
+                        log_device_debug_errno(d, r, "Failed to trigger 'change' event, ignoring: %m");
+                        continue;
+                }
+
+                _cleanup_free_ sd_id128_t *copy = newdup(sd_id128_t, &uuid, 1);
+                if (!copy)
+                        return -ENOMEM;
+
+                r = set_ensure_consume(&s->uevents, &id128_hash_ops_free, TAKE_PTR(copy));
+                if (r < 0)
+                        return r;
+        }
+
+        seat_triggered_uevents_done(s);
         return 0;
 }
 
@@ -237,7 +340,7 @@ int seat_set_active(Seat *s, Session *session) {
          * Therefore, if the active session has executed session_leave_vt ,
          * A resume is required here. */
         if (session == s->active) {
-                if (session) {
+                if (session && set_isempty(s->uevents)) {
                         log_debug("Active session remains unchanged, resuming session devices.");
                         session_device_resume_all(session);
                 }
@@ -250,32 +353,13 @@ int seat_set_active(Seat *s, Session *session) {
         seat_save(s);
 
         if (old_active) {
+                user_save(old_active->user);
+                session_save(old_active);
                 session_device_pause_all(old_active);
                 session_send_changed(old_active, "Active");
         }
 
-        (void) seat_apply_acls(s, old_active);
-
-        if (session && session->started) {
-                session_send_changed(session, "Active");
-                session_device_resume_all(session);
-        }
-
-        if (!session || session->started)
-                seat_send_changed(s, "ActiveSession");
-
-        if (session) {
-                session_save(session);
-                user_save(session->user);
-        }
-
-        if (old_active) {
-                session_save(old_active);
-                if (!session || session->user != old_active->user)
-                        user_save(old_active->user);
-        }
-
-        return 0;
+        return seat_trigger_devices(s);
 }
 
 static Session* seat_get_position(Seat *s, unsigned pos) {
diff --git a/src/login/logind-seat.h b/src/login/logind-seat.h
index 4c4a6fa6bd..2dc57686e9 100644
--- a/src/login/logind-seat.h
+++ b/src/login/logind-seat.h
@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#include "sd-device.h"
+
 #include "list.h"
 #include "memory-util.h"
 #include "string-util.h"
@@ -19,6 +21,8 @@ struct Seat {
 
         LIST_HEAD(Device, devices);
 
+        Set *uevents;
+
         Session *active;
         Session *pending_switch;
         LIST_HEAD(Session, sessions);
@@ -39,7 +43,8 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(Seat*, seat_free);
 int seat_save(Seat *s);
 int seat_load(Seat *s);
 
-int seat_apply_acls(Seat *s, Session *old_active);
+int manager_process_device_triggered_by_seat(Manager *m, sd_device *dev);
+
 int seat_set_active(Seat *s, Session *session);
 int seat_switch_to(Seat *s, unsigned num);
 int seat_switch_to_next(Seat *s);
diff --git a/src/login/logind-session-dbus.c b/src/login/logind-session-dbus.c
index f3fe877a2c..50a965c5ff 100644
--- a/src/login/logind-session-dbus.c
+++ b/src/login/logind-session-dbus.c
@@ -9,6 +9,7 @@
 #include "bus-label.h"
 #include "bus-polkit.h"
 #include "bus-util.h"
+#include "device-util.h"
 #include "devnum-util.h"
 #include "fd-util.h"
 #include "format-util.h"
@@ -705,7 +706,10 @@ static int method_set_brightness(sd_bus_message *message, void *userdata, sd_bus
         if (r < 0)
                 return sd_bus_error_set_errnof(error, r, "Failed to open device %s:%s: %m", subsystem, name);
 
-        if (sd_device_get_property_value(d, "ID_SEAT", &seat) >= 0 && !streq_ptr(seat, s->seat->id))
+        r = device_get_seat(d, &seat);
+        if (r < 0)
+                return sd_bus_error_set_errnof(error, r, "Failed to get seat of %s:%s: %m", subsystem, name);
+        if (!streq(seat, s->seat->id))
                 return sd_bus_error_setf(error, BUS_ERROR_NOT_YOUR_DEVICE, "Device %s:%s does not belong to your seat %s, refusing.", subsystem, name, s->seat->id);
 
         r = manager_write_brightness(s->manager, d, brightness, message);
diff --git a/src/login/logind-session-device.c b/src/login/logind-session-device.c
index c51660540d..9e592740e8 100644
--- a/src/login/logind-session-device.c
+++ b/src/login/logind-session-device.c
@@ -273,21 +273,22 @@ static void session_device_stop(SessionDevice *sd) {
 }
 
 static DeviceType detect_device_type(sd_device *dev) {
-        const char *sysname;
-
-        if (sd_device_get_sysname(dev, &sysname) < 0)
-                return DEVICE_TYPE_UNKNOWN;
-
-        if (device_in_subsystem(dev, "drm")) {
-                if (startswith(sysname, "card"))
+        if (device_in_subsystem(dev, "drm") > 0) {
+                if (device_sysname_startswith(dev, "card") > 0)
                         return DEVICE_TYPE_DRM;
+                return DEVICE_TYPE_UNKNOWN;
+        }
 
-        } else if (device_in_subsystem(dev, "input")) {
-                if (startswith(sysname, "event"))
+        if (device_in_subsystem(dev, "input") > 0) {
+                if (device_sysname_startswith(dev, "event") > 0)
                         return DEVICE_TYPE_EVDEV;
-        } else if (device_in_subsystem(dev, "hidraw")) {
-                if (startswith(sysname, "hidraw"))
+                return DEVICE_TYPE_UNKNOWN;
+        }
+
+        if (device_in_subsystem(dev, "hidraw") > 0) {
+                if (device_sysname_startswith(dev, "hidraw") > 0)
                         return DEVICE_TYPE_HIDRAW;
+                return DEVICE_TYPE_UNKNOWN;
         }
 
         return DEVICE_TYPE_UNKNOWN;
diff --git a/src/login/logind.c b/src/login/logind.c
index aeace67315..2a59c4af52 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -610,34 +610,72 @@ static int manager_enumerate_inhibitors(Manager *m) {
 
 static int manager_dispatch_seat_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
         Manager *m = ASSERT_PTR(userdata);
+        int r;
 
         assert(device);
 
-        manager_process_seat_device(m, device);
+        /* If the event is triggered by us, do not try to start the relevant seat again. Otherwise, starting
+         * the seat may trigger uevents again again again... */
+        r = manager_process_device_triggered_by_seat(m, device);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Failed to process seat device event triggered by us, ignoring: %m");
+        if (r != 0)
+                return 0;
+
+        r = manager_process_seat_device(m, device);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Failed to process seat device, ignoring: %m");
+
         return 0;
 }
 
 static int manager_dispatch_device_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
         Manager *m = ASSERT_PTR(userdata);
+        int r;
 
         assert(device);
 
-        manager_process_seat_device(m, device);
+        /* If the device currently has "master-of-seat" tag, then it has been or will be processed by
+         * manager_dispatch_seat_udev(). */
+        r = sd_device_has_current_tag(device, "master-of-seat");
+        if (r < 0)
+                log_device_warning_errno(device, r, "Failed to check if the device currently has master-of-seat tag, ignoring: %m");
+        if (r != 0)
+                return 0;
+
+        /* If the event is triggered by us, do not try to start the relevant seat again. Otherwise, starting
+         * the seat may trigger uevents again again again... */
+        r = manager_process_device_triggered_by_seat(m, device);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Failed to process seat device event triggered by us, ignoring: %m");
+        if (r != 0)
+                return 0;
+
+        r = manager_process_seat_device(m, device);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Failed to process seat device, ignoring: %m");
+
         return 0;
 }
 
 static int manager_dispatch_vcsa_udev(sd_device_monitor *monitor, sd_device *device, void *userdata) {
         Manager *m = ASSERT_PTR(userdata);
-        const char *name;
+        int r;
 
         assert(device);
 
         /* Whenever a VCSA device is removed try to reallocate our
          * VTs, to make sure our auto VTs never go away. */
 
-        if (sd_device_get_sysname(device, &name) >= 0 &&
-            startswith(name, "vcsa") &&
-            device_for_action(device, SD_DEVICE_REMOVE))
+        r = device_sysname_startswith(device, "vcsa");
+        if (r < 0) {
+                log_device_debug_errno(device, r, "Failed to check device sysname, ignoring: %m");
+                return 0;
+        }
+        if (r == 0)
+                return 0;
+
+        if (device_for_action(device, SD_DEVICE_REMOVE))
                 seat_preallocate_vts(m->seat0);
 
         return 0;
@@ -883,17 +921,11 @@ static int manager_connect_udev(Manager *m) {
         if (r < 0)
                 return r;
 
-        r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "input", NULL);
-        if (r < 0)
-                return r;
-
-        r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "graphics", NULL);
-        if (r < 0)
-                return r;
-
-        r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, "drm", NULL);
-        if (r < 0)
-                return r;
+        FOREACH_STRING(s, "input", "graphics", "drm") {
+                r = sd_device_monitor_filter_add_match_subsystem_devtype(m->device_monitor, s, /* devtype = */ NULL);
+                if (r < 0)
+                        return r;
+        }
 
         r = sd_device_monitor_attach_event(m->device_monitor, m->event);
         if (r < 0)
diff --git a/src/login/sysfs-show.c b/src/login/sysfs-show.c
index 43eb13ac83..d1f105b1e3 100644
--- a/src/login/sysfs-show.c
+++ b/src/login/sysfs-show.c
@@ -6,6 +6,7 @@
 
 #include "alloc-util.h"
 #include "device-enumerator-private.h"
+#include "device-util.h"
 #include "glyph-util.h"
 #include "path-util.h"
 #include "string-util.h"
@@ -47,8 +48,9 @@ static int show_sysfs_one(
                     !path_startswith(sysfs, sub))
                         return 0;
 
-                if (sd_device_get_property_value(dev_list[*i_dev], "ID_SEAT", &sn) < 0 || isempty(sn))
-                        sn = "seat0";
+                r = device_get_seat(dev_list[*i_dev], &sn);
+                if (r < 0)
+                        return r;
 
                 /* Explicitly also check for tag 'seat' here */
                 if (!streq(seat, sn) ||
@@ -75,9 +77,9 @@ static int show_sysfs_one(
                             !path_startswith(lookahead_sysfs, sysfs)) {
                                 const char *lookahead_sn;
 
-                                if (sd_device_get_property_value(dev_list[lookahead], "ID_SEAT", &lookahead_sn) < 0 ||
-                                    isempty(lookahead_sn))
-                                        lookahead_sn = "seat0";
+                                r = device_get_seat(dev_list[lookahead], &lookahead_sn);
+                                if (r < 0)
+                                        return r;
 
                                 if (streq(seat, lookahead_sn) && sd_device_has_current_tag(dev_list[lookahead], "seat") > 0)
                                         break;
diff --git a/src/mount/mount-tool.c b/src/mount/mount-tool.c
index 2c64ccdf30..71fe112702 100644
--- a/src/mount/mount-tool.c
+++ b/src/mount/mount-tool.c
@@ -1302,6 +1302,7 @@ static int acquire_description(sd_device *d) {
 
 static int acquire_removable(sd_device *d) {
         const char *v;
+        int r;
 
         assert(d);
 
@@ -1313,10 +1314,16 @@ static int acquire_removable(sd_device *d) {
                 if (sd_device_get_sysattr_value(d, "removable", &v) >= 0)
                         break;
 
-                if (sd_device_get_parent(d, &d) < 0)
+                r = sd_device_get_parent(d, &d);
+                if (r == -ENODEV)
                         return 0;
+                if (r < 0)
+                        return r;
 
-                if (!device_in_subsystem(d, "block"))
+                r = device_in_subsystem(d, "block");
+                if (r < 0)
+                        return r;
+                if (r == 0)
                         return 0;
         }
 
diff --git a/src/network/networkctl-link-info.c b/src/network/networkctl-link-info.c
index 1768688980..c687da9e0f 100644
--- a/src/network/networkctl-link-info.c
+++ b/src/network/networkctl-link-info.c
@@ -327,7 +327,7 @@ static void acquire_wlan_link_info(LinkInfo *link) {
         if (!link->sd_device)
                 return;
 
-        if (!device_is_devtype(link->sd_device, "wlan"))
+        if (device_is_devtype(link->sd_device, "wlan") <= 0)
                 return;
 
         r = sd_genl_socket_open(&genl);
diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
index cf713f3ffe..7d29298d83 100644
--- a/src/network/networkd-manager.c
+++ b/src/network/networkd-manager.c
@@ -170,11 +170,11 @@ static int manager_process_uevent(sd_device_monitor *monitor, sd_device *device,
         if (r < 0)
                 return log_device_warning_errno(device, r, "Failed to get udev action, ignoring: %m");
 
-        if (device_in_subsystem(device, "net"))
+        if (device_in_subsystem(device, "net") > 0)
                 r = manager_udev_process_link(m, device, action);
-        else if (device_in_subsystem(device, "ieee80211"))
+        else if (device_in_subsystem(device, "ieee80211") > 0)
                 r = manager_udev_process_wiphy(m, device, action);
-        else if (device_in_subsystem(device, "rfkill"))
+        else if (device_in_subsystem(device, "rfkill") > 0)
                 r = manager_udev_process_rfkill(m, device, action);
         if (r < 0)
                 log_device_warning_errno(device, r, "Failed to process \"%s\" uevent, ignoring: %m",
diff --git a/src/network/networkd-wiphy.c b/src/network/networkd-wiphy.c
index 0641fea370..33f7fe680f 100644
--- a/src/network/networkd-wiphy.c
+++ b/src/network/networkd-wiphy.c
@@ -126,7 +126,10 @@ static int link_get_wiphy(Link *link, Wiphy **ret) {
         if (!link->dev)
                 return -ENODEV;
 
-        if (!device_is_devtype(link->dev, "wlan"))
+        r = device_is_devtype(link->dev, "wlan");
+        if (r < 0)
+                return r;
+        if (r == 0)
                 return -EOPNOTSUPP;
 
         r = sd_device_new_child(&phy, link->dev, "phy80211");
diff --git a/src/shared/acl-util.c b/src/shared/acl-util.c
index db3341d083..b5c8fa0135 100644
--- a/src/shared/acl-util.c
+++ b/src/shared/acl-util.c
@@ -16,7 +16,7 @@
 
 #if HAVE_ACL
 
-int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *ret_entry) {
+static int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *ret_entry) {
         acl_entry_t i;
         int r;
 
diff --git a/src/shared/acl-util.h b/src/shared/acl-util.h
index 3fe3d6c735..8d62e6460f 100644
--- a/src/shared/acl-util.h
+++ b/src/shared/acl-util.h
@@ -15,7 +15,6 @@ int fd_acl_make_writable_fallback(int fd);
 #include "macro.h"
 #include "memory-util.h"
 
-int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry);
 int calc_acl_mask_if_needed(acl_t *acl_p);
 int add_base_acls_if_needed(acl_t *acl_p, const char *path);
 int acl_search_groups(const char* path, char ***ret_groups);
diff --git a/src/shared/blockdev-list.c b/src/shared/blockdev-list.c
index d38f1e4b2c..4c43fb6762 100644
--- a/src/shared/blockdev-list.c
+++ b/src/shared/blockdev-list.c
@@ -37,15 +37,12 @@ int blockdev_list(BlockDevListFlags flags) {
                 }
 
                 if (FLAGS_SET(flags, BLOCKDEV_LIST_IGNORE_ZRAM)) {
-                        const char *dn;
-
-                        r = sd_device_get_sysname(dev, &dn);
+                        r = device_sysname_startswith(dev, "zram");
                         if (r < 0) {
-                                log_warning_errno(r, "Failed to get device name of discovered block device '%s', ignoring: %m", node);
+                                log_warning_errno(r, "Failed to check device name of discovered block device '%s', ignoring: %m", node);
                                 continue;
                         }
-
-                        if (startswith(dn, "zram"))
+                        if (r > 0)
                                 continue;
                 }
 
diff --git a/src/shared/blockdev-util.c b/src/shared/blockdev-util.c
index 968ff6adc3..fc3c3e7d14 100644
--- a/src/shared/blockdev-util.c
+++ b/src/shared/blockdev-util.c
@@ -57,9 +57,14 @@ static int fd_get_devnum(int fd, BlockDeviceLookupFlag flags, dev_t *ret) {
 }
 
 int block_device_is_whole_disk(sd_device *dev) {
+        int r;
+
         assert(dev);
 
-        if (!device_in_subsystem(dev, "block"))
+        r = device_in_subsystem(dev, "block");
+        if (r < 0)
+                return r;
+        if (r == 0)
                 return -ENOTBLK;
 
         return device_is_devtype(dev, "disk");
@@ -414,7 +419,10 @@ int blockdev_partscan_enabled(sd_device *dev) {
 
         /* Partition block devices never have partition scanning on, there's no concept of sub-partitions for
          * partitions. */
-        if (device_is_devtype(dev, "partition"))
+        r = device_is_devtype(dev, "partition");
+        if (r < 0)
+                return r;
+        if (r > 0)
                 return false;
 
         /* For loopback block device, especially for v5.19 or newer. Even if this is enabled, we also need to
diff --git a/src/shared/devnode-acl.c b/src/shared/devnode-acl.c
deleted file mode 100644
index 81961c5b05..0000000000
--- a/src/shared/devnode-acl.c
+++ /dev/null
@@ -1,227 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-
-#include <errno.h>
-
-#include "sd-device.h"
-
-#include "acl-util.h"
-#include "alloc-util.h"
-#include "device-util.h"
-#include "devnode-acl.h"
-#include "dirent-util.h"
-#include "errno-util.h"
-#include "fd-util.h"
-#include "format-util.h"
-#include "fs-util.h"
-#include "glyph-util.h"
-#include "set.h"
-#include "string-util.h"
-
-static int flush_acl(acl_t acl) {
-        acl_entry_t i;
-        int found;
-        bool changed = false;
-
-        assert(acl);
-
-        for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
-             found > 0;
-             found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
-
-                acl_tag_t tag;
-
-                if (acl_get_tag_type(i, &tag) < 0)
-                        return -errno;
-
-                if (tag != ACL_USER)
-                        continue;
-
-                if (acl_delete_entry(acl, i) < 0)
-                        return -errno;
-
-                changed = true;
-        }
-
-        if (found < 0)
-                return -errno;
-
-        return changed;
-}
-
-int devnode_acl(const char *path,
-                bool flush,
-                bool del, uid_t old_uid,
-                bool add, uid_t new_uid) {
-
-        _cleanup_(acl_freep) acl_t acl = NULL;
-        int r;
-        bool changed = false;
-
-        assert(path);
-
-        acl = acl_get_file(path, ACL_TYPE_ACCESS);
-        if (!acl)
-                return -errno;
-
-        if (flush) {
-
-                r = flush_acl(acl);
-                if (r < 0)
-                        return r;
-                if (r > 0)
-                        changed = true;
-
-        } else if (del && old_uid > 0) {
-                acl_entry_t entry;
-
-                r = acl_find_uid(acl, old_uid, &entry);
-                if (r < 0)
-                        return r;
-
-                if (r > 0) {
-                        if (acl_delete_entry(acl, entry) < 0)
-                                return -errno;
-
-                        changed = true;
-                }
-        }
-
-        if (add && new_uid > 0) {
-                acl_entry_t entry;
-                acl_permset_t permset;
-                int rd, wt;
-
-                r = acl_find_uid(acl, new_uid, &entry);
-                if (r < 0)
-                        return r;
-
-                if (r == 0) {
-                        if (acl_create_entry(&acl, &entry) < 0)
-                                return -errno;
-
-                        if (acl_set_tag_type(entry, ACL_USER) < 0 ||
-                            acl_set_qualifier(entry, &new_uid) < 0)
-                                return -errno;
-                }
-
-                if (acl_get_permset(entry, &permset) < 0)
-                        return -errno;
-
-                rd = acl_get_perm(permset, ACL_READ);
-                if (rd < 0)
-                        return -errno;
-
-                wt = acl_get_perm(permset, ACL_WRITE);
-                if (wt < 0)
-                        return -errno;
-
-                if (!rd || !wt) {
-
-                        if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0)
-                                return -errno;
-
-                        changed = true;
-                }
-        }
-
-        if (!changed)
-                return 0;
-
-        if (acl_calc_mask(&acl) < 0)
-                return -errno;
-
-        if (acl_set_file(path, ACL_TYPE_ACCESS, acl) < 0)
-                return -errno;
-
-        return 0;
-}
-
-int devnode_acl_all(const char *seat,
-                    bool flush,
-                    bool del, uid_t old_uid,
-                    bool add, uid_t new_uid) {
-
-        _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
-        _cleanup_set_free_ Set *nodes = NULL;
-        _cleanup_closedir_ DIR *dir = NULL;
-        char *n;
-        int r;
-
-        r = sd_device_enumerator_new(&e);
-        if (r < 0)
-                return r;
-
-        if (isempty(seat))
-                seat = "seat0";
-
-        /* We can only match by one tag in libudev. We choose
-         * "uaccess" for that. If we could match for two tags here we
-         * could add the seat name as second match tag, but this would
-         * be hardly optimizable in libudev, and hence checking the
-         * second tag manually in our loop is a good solution. */
-        r = sd_device_enumerator_add_match_tag(e, "uaccess");
-        if (r < 0)
-                return r;
-
-        FOREACH_DEVICE(e, d) {
-                const char *node, *sn;
-
-                /* Make sure the tag is still in place */
-                if (sd_device_has_current_tag(d, "uaccess") <= 0)
-                        continue;
-
-                if (sd_device_get_property_value(d, "ID_SEAT", &sn) < 0 || isempty(sn))
-                        sn = "seat0";
-
-                if (!streq(seat, sn))
-                        continue;
-
-                /* In case people mistag devices with nodes, we need to ignore this */
-                if (sd_device_get_devname(d, &node) < 0)
-                        continue;
-
-                log_device_debug(d, "Found udev node %s for seat %s", node, seat);
-                r = set_put_strdup_full(&nodes, &path_hash_ops_free, node);
-                if (r < 0)
-                        return r;
-        }
-
-        /* udev exports "dead" device nodes to allow module on-demand loading,
-         * these devices are not known to the kernel at this moment */
-        dir = opendir("/run/udev/static_node-tags/uaccess");
-        if (dir) {
-                FOREACH_DIRENT(de, dir, return -errno) {
-                        r = readlinkat_malloc(dirfd(dir), de->d_name, &n);
-                        if (r == -ENOENT)
-                                continue;
-                        if (r < 0) {
-                                log_debug_errno(r,
-                                                "Unable to read symlink '/run/udev/static_node-tags/uaccess/%s', ignoring: %m",
-                                                de->d_name);
-                                continue;
-                        }
-
-                        log_debug("Found static node %s for seat %s", n, seat);
-                        r = set_ensure_consume(&nodes, &path_hash_ops_free, n);
-                        if (r < 0)
-                                return r;
-                }
-        }
-
-        r = 0;
-        SET_FOREACH(n, nodes) {
-                int k;
-
-                log_debug("Changing ACLs at %s for seat %s (uid "UID_FMT"%s"UID_FMT"%s%s)",
-                          n, seat, old_uid, glyph(GLYPH_ARROW_RIGHT), new_uid,
-                          del ? " del" : "", add ? " add" : "");
-
-                k = devnode_acl(n, flush, del, old_uid, add, new_uid);
-                if (k == -ENOENT)
-                        log_debug("Device %s disappeared while setting ACLs", n);
-                else
-                        RET_GATHER(r, k);
-        }
-
-        return r;
-}
diff --git a/src/shared/devnode-acl.h b/src/shared/devnode-acl.h
deleted file mode 100644
index c88f3c0cf3..0000000000
--- a/src/shared/devnode-acl.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-#pragma once
-
-#include <stdbool.h>
-#include <sys/types.h>
-
-#if HAVE_ACL
-
-int devnode_acl(const char *path,
-                bool flush,
-                bool del, uid_t old_uid,
-                bool add, uid_t new_uid);
-
-int devnode_acl_all(const char *seat,
-                    bool flush,
-                    bool del, uid_t old_uid,
-                    bool add, uid_t new_uid);
-#else
-
-static inline int devnode_acl(const char *path,
-                bool flush,
-                bool del, uid_t old_uid,
-                bool add, uid_t new_uid) {
-        return 0;
-}
-
-static inline int devnode_acl_all(const char *seat,
-                                  bool flush,
-                                  bool del, uid_t old_uid,
-                                  bool add, uid_t new_uid) {
-        return 0;
-}
-
-#endif
diff --git a/src/shared/meson.build b/src/shared/meson.build
index b5522637f0..d57bd93da1 100644
--- a/src/shared/meson.build
+++ b/src/shared/meson.build
@@ -238,10 +238,6 @@ syscall_list_h = custom_target(
 
 generated_sources += syscall_list_h
 
-if conf.get('HAVE_ACL') == 1
-        shared_sources += files('devnode-acl.c')
-endif
-
 if conf.get('ENABLE_UTMP') == 1
         shared_sources += files('utmp-wtmp.c')
 endif
diff --git a/src/udev/test-udev-rule-runner.c b/src/udev/test-udev-rule-runner.c
index 9ad446aa2d..3371892ec4 100644
--- a/src/udev/test-udev-rule-runner.c
+++ b/src/udev/test-udev-rule-runner.c
@@ -151,7 +151,10 @@ static int run(int argc, char *argv[]) {
         if (sd_device_get_devname(dev, &devname) >= 0) {
                 mode_t mode = 0600;
 
-                if (device_in_subsystem(dev, "block"))
+                r = device_in_subsystem(dev, "block");
+                if (r < 0)
+                        return r;
+                if (r > 0)
                         mode |= S_IFBLK;
                 else
                         mode |= S_IFCHR;
diff --git a/src/udev/udev-builtin-blkid.c b/src/udev/udev-builtin-blkid.c
index 1448fa3f04..6cd738c3a5 100644
--- a/src/udev/udev-builtin-blkid.c
+++ b/src/udev/udev-builtin-blkid.c
@@ -364,7 +364,6 @@ static int read_loopback_backing_inode(
 
         _cleanup_free_ char *fn = NULL;
         struct loop_info64 info;
-        const char *name;
         int r;
 
         assert(dev);
@@ -381,11 +380,10 @@ static int read_loopback_backing_inode(
          * sometimes, depending on context, it's a good thing to return the string userspace can freely pick
          * over the string automatically generated by the kernel. */
 
-        r = sd_device_get_sysname(dev, &name);
+        r = device_sysname_startswith(dev, "loop");
         if (r < 0)
                 return r;
-
-        if (!startswith(name, "loop"))
+        if (r == 0)
                 goto notloop;
 
         if (ioctl(fd, LOOP_GET_STATUS64, &info) < 0) {
diff --git a/src/udev/udev-builtin-dissect_image.c b/src/udev/udev-builtin-dissect_image.c
index 8bc8df990c..5d6b0d8fce 100644
--- a/src/udev/udev-builtin-dissect_image.c
+++ b/src/udev/udev-builtin-dissect_image.c
@@ -318,20 +318,22 @@ static int verb_copy(UdevEvent *event, sd_device *dev) {
         if (r < 0)
                 return log_device_debug_errno(dev, r, "Failed to get device node: %m");
 
-        if (!device_in_subsystem(dev, "block"))
-                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Invoked on non-block device '%s', refusing: %m", devnode);
-        if (!device_is_devtype(dev, "partition"))
-                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Invoked on non-partition block device '%s', refusing: %m", devnode);
+        r = device_is_subsystem_devtype(dev, "block", "partition");
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to check if the device '%s' is a partition, refusing: %m", devnode);
+        if (r == 0)
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Invoked on non-partition device '%s', refusing.", devnode);
 
         sd_device *parent;
         r = sd_device_get_parent(dev, &parent);
         if (r < 0)
                 return log_error_errno(r, "Failed to get parent of device '%s': %m", devnode);
 
-        if (!device_in_subsystem(parent, "block"))
-                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Parent of block device '%s' is not a block device, refusing: %m", devnode);
-        if (!device_is_devtype(parent, "disk"))
-                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Parent of block device '%s' is not a whole block device, refusing: %m", devnode);
+        r = device_is_subsystem_devtype(parent, "block", "disk");
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to check if the parent of block device '%s' is a whole block device, refusing: %m", devnode);
+        if (r == 0)
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Parent of block device '%s' is not a whole block device, refusing.", devnode);
 
         const char *partn;
         r = sd_device_get_property_value(dev, "PARTN", &partn);
diff --git a/src/udev/udev-builtin-hwdb.c b/src/udev/udev-builtin-hwdb.c
index 458ce6968a..6e82ad8c75 100644
--- a/src/udev/udev-builtin-hwdb.c
+++ b/src/udev/udev-builtin-hwdb.c
@@ -88,12 +88,20 @@ static int udev_builtin_hwdb_search(
                 const char *modalias = NULL;
 
                 /* look only at devices of a specific subsystem */
-                if (subsystem && !device_in_subsystem(d, subsystem))
-                        goto next;
+                if (subsystem) {
+                        r = device_in_subsystem(d, subsystem);
+                        if (r < 0)
+                                return r;
+                        if (r == 0)
+                                goto next;
+                }
 
                 (void) sd_device_get_property_value(d, "MODALIAS", &modalias);
 
-                if (device_in_subsystem(d, "usb") && device_is_devtype(d, "usb_device")) {
+                r = device_is_subsystem_devtype(d, "usb", "usb_device");
+                if (r < 0)
+                        return r;
+                if (r > 0) {
                         /* if the usb_device does not have a modalias, compose one */
                         if (!modalias)
                                 modalias = modalias_usb(d, s, sizeof(s));
diff --git a/src/udev/udev-builtin-input_id.c b/src/udev/udev-builtin-input_id.c
index 60fc95e0d2..f8ac6d5517 100644
--- a/src/udev/udev-builtin-input_id.c
+++ b/src/udev/udev-builtin-input_id.c
@@ -384,8 +384,8 @@ static int builtin_input_id(UdevEvent *event, int argc, char *argv[]) {
                 bitmask_key[NBITS(KEY_MAX)],
                 bitmask_rel[NBITS(REL_MAX)],
                 bitmask_props[NBITS(INPUT_PROP_MAX)];
-        const char *sysname;
         bool is_pointer, is_key;
+        int r;
 
         /* walk up the parental chain until we find the real input device; the
          * argument is very likely a subdevice of this, like eventN */
@@ -425,8 +425,10 @@ static int builtin_input_id(UdevEvent *event, int argc, char *argv[]) {
                         udev_builtin_add_property(event, "ID_INPUT_SWITCH", "1");
         }
 
-        if (sd_device_get_sysname(dev, &sysname) >= 0 &&
-            startswith(sysname, "event"))
+        r = device_sysname_startswith(dev, "event");
+        if (r < 0)
+                return r;
+        if (r > 0)
                 extract_info(event);
 
         return 0;
diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index e20faae8df..a5ace58db6 100644
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -43,20 +43,29 @@
 #define ONBOARD_14BIT_INDEX_MAX ((1U << 14) - 1)
 #define ONBOARD_16BIT_INDEX_MAX ((1U << 16) - 1)
 
-/* skip intermediate virtio devices */
-static sd_device *device_skip_virtio(sd_device *dev) {
-        /* there can only ever be one virtio bus per parent device, so we can
-         * safely ignore any virtio buses. see
+static int device_get_parent_skip_virtio(sd_device *dev, sd_device **ret) {
+        int r;
+
+        assert(dev);
+        assert(ret);
+
+        /* This provides the parent device, but skips intermediate virtio devices. There can only ever be one
+         * virtio bus per parent device, so we can safely ignore any virtio buses. See
          * https://lore.kernel.org/virtualization/CAPXgP137A=CdmggtVPUZXbnpTbU9Tewq-sOjg9T8ohYktct1kQ@mail.gmail.com/ */
-        while (dev) {
-                if (!device_in_subsystem(dev, "virtio"))
-                        break;
 
-                if (sd_device_get_parent(dev, &dev) < 0)
-                        return NULL;
+        for (;;) {
+                r = sd_device_get_parent(dev, &dev);
+                if (r < 0)
+                        return r;
+
+                r = device_in_subsystem(dev, "virtio");
+                if (r < 0)
+                        return r;
+                if (r == 0) {
+                        *ret = dev;
+                        return 0;
+                }
         }
-
-        return dev;
 }
 
 static int get_matching_parent(
@@ -70,26 +79,23 @@ static int get_matching_parent(
 
         assert(dev);
 
-        r = sd_device_get_parent(dev, &parent);
+        if (skip_virtio)
+                r = device_get_parent_skip_virtio(dev, &parent);
+        else
+                r = sd_device_get_parent(dev, &parent);
         if (r < 0)
                 return r;
 
-        if (skip_virtio) {
-                /* skip virtio subsystem if present */
-                parent = device_skip_virtio(parent);
-                if (!parent)
-                        return -ENODEV;
-        }
-
         /* check if our direct parent is in an expected subsystem. */
-        STRV_FOREACH(s, parent_subsystems)
-                if (device_in_subsystem(parent, *s)) {
-                        if (ret)
-                                *ret = parent;
-                        return 0;
-                }
+        r = device_in_subsystem_strv(parent, parent_subsystems);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ENODEV;
 
-        return -ENODEV;
+        if (ret)
+                *ret = parent;
+        return 0;
 }
 
 static int get_first_syspath_component(sd_device *dev, const char *prefix, char **ret) {
@@ -1284,9 +1290,9 @@ static int get_ifname_prefix(sd_device *dev, const char **ret) {
         /* handle only ARPHRD_ETHER, ARPHRD_SLIP and ARPHRD_INFINIBAND devices */
         switch (iftype) {
         case ARPHRD_ETHER: {
-                if (device_is_devtype(dev, "wlan"))
+                if (device_is_devtype(dev, "wlan") > 0)
                         *ret = "wl";
-                else if (device_is_devtype(dev, "wwan"))
+                else if (device_is_devtype(dev, "wwan") > 0)
                         *ret = "ww";
                 else
                         *ret = "en";
diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c
index 5237ae3090..27897b461f 100644
--- a/src/udev/udev-builtin-path_id.c
+++ b/src/udev/udev-builtin-path_id.c
@@ -89,7 +89,7 @@ static sd_device* skip_subsystem(sd_device *dev, const char *subsys) {
          */
 
         for (parent = dev; ; ) {
-                if (!device_in_subsystem(parent, subsys))
+                if (device_in_subsystem(parent, subsys) <= 0)
                         break;
 
                 dev = parent;
@@ -404,7 +404,7 @@ static sd_device* handle_scsi_hyperv(sd_device *parent, char **path, size_t guid
 static sd_device* handle_scsi(sd_device *parent, char **path, char **compat_path, bool *supported_parent) {
         const char *id, *name;
 
-        if (!device_is_devtype(parent, "scsi_device"))
+        if (device_is_devtype(parent, "scsi_device") <= 0)
                 return parent;
 
         /* firewire */
@@ -519,7 +519,7 @@ static sd_device* handle_usb(sd_device *parent, char **path) {
         const char *str, *port;
         int r;
 
-        if (!device_is_devtype(parent, "usb_interface") && !device_is_devtype(parent, "usb_device"))
+        if (device_is_devtype(parent, "usb_interface") <= 0 && device_is_devtype(parent, "usb_device") <= 0)
                 return parent;
 
         if (sd_device_get_sysname(parent, &str) < 0)
@@ -699,95 +699,95 @@ static int builtin_path_id(UdevEvent *event, int argc, char *argv[]) {
 
                 if (sd_device_get_sysname(parent, &sysname) < 0) {
                         ;
-                } else if (device_in_subsystem(parent, "scsi_tape")) {
+                } else if (device_in_subsystem(parent, "scsi_tape") > 0) {
                         handle_scsi_tape(parent, &path);
-                } else if (device_in_subsystem(parent, "scsi")) {
+                } else if (device_in_subsystem(parent, "scsi") > 0) {
                         parent = handle_scsi(parent, &path, &compat_path, &supported_parent);
                         supported_transport = true;
-                } else if (device_in_subsystem(parent, "cciss")) {
+                } else if (device_in_subsystem(parent, "cciss") > 0) {
                         parent = handle_cciss(parent, &path);
                         supported_transport = true;
-                } else if (device_in_subsystem(parent, "usb")) {
+                } else if (device_in_subsystem(parent, "usb") > 0) {
                         parent = handle_usb(parent, &path);
                         supported_transport = true;
-                } else if (device_in_subsystem(parent, "bcma")) {
+                } else if (device_in_subsystem(parent, "bcma") > 0) {
                         parent = handle_bcma(parent, &path);
                         supported_transport = true;
-                } else if (device_in_subsystem(parent, "serio")) {
+                } else if (device_in_subsystem(parent, "serio") > 0) {
                         const char *sysnum;
 
                         if (sd_device_get_sysnum(parent, &sysnum) >= 0) {
                                 path_prepend(&path, "serio-%s", sysnum);
                                 parent = skip_subsystem(parent, "serio");
                         }
-                } else if (device_in_subsystem(parent, "pci")) {
+                } else if (device_in_subsystem(parent, "pci") > 0) {
                         path_prepend(&path, "pci-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "pci-%s", sysname);
                         parent = skip_subsystem(parent, "pci");
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "platform")) {
+                } else if (device_in_subsystem(parent, "platform") > 0) {
                         path_prepend(&path, "platform-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "platform-%s", sysname);
                         parent = skip_subsystem(parent, "platform");
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "amba")) {
+                } else if (device_in_subsystem(parent, "amba") > 0) {
                         path_prepend(&path, "amba-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "amba-%s", sysname);
                         parent = skip_subsystem(parent, "amba");
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "acpi")) {
+                } else if (device_in_subsystem(parent, "acpi") > 0) {
                         path_prepend(&path, "acpi-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "acpi-%s", sysname);
                         parent = skip_subsystem(parent, "acpi");
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "xen")) {
+                } else if (device_in_subsystem(parent, "xen") > 0) {
                         path_prepend(&path, "xen-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "xen-%s", sysname);
                         parent = skip_subsystem(parent, "xen");
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "virtio")) {
+                } else if (device_in_subsystem(parent, "virtio") > 0) {
                         parent = skip_subsystem(parent, "virtio");
                         supported_transport = true;
-                } else if (device_in_subsystem(parent, "scm")) {
+                } else if (device_in_subsystem(parent, "scm") > 0) {
                         path_prepend(&path, "scm-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "scm-%s", sysname);
                         parent = skip_subsystem(parent, "scm");
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "ccw")) {
+                } else if (device_in_subsystem(parent, "ccw") > 0) {
                         path_prepend(&path, "ccw-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "ccw-%s", sysname);
                         parent = skip_subsystem(parent, "ccw");
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "ccwgroup")) {
+                } else if (device_in_subsystem(parent, "ccwgroup") > 0) {
                         path_prepend(&path, "ccwgroup-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "ccwgroup-%s", sysname);
                         parent = skip_subsystem(parent, "ccwgroup");
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "ap")) {
+                } else if (device_in_subsystem(parent, "ap") > 0) {
                         parent = handle_ap(parent, &path);
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "iucv")) {
+                } else if (device_in_subsystem(parent, "iucv") > 0) {
                         path_prepend(&path, "iucv-%s", sysname);
                         if (compat_path)
                                 path_prepend(&compat_path, "iucv-%s", sysname);
                         parent = skip_subsystem(parent, "iucv");
                         supported_transport = true;
                         supported_parent = true;
-                } else if (device_in_subsystem(parent, "nvme") || device_in_subsystem(parent, "nvme-subsystem")) {
+                } else if (device_in_subsystem(parent, "nvme", "nvme-subsystem") > 0) {
                         const char *nsid;
 
                         if (sd_device_get_sysattr_value(dev, "nsid", &nsid) >= 0) {
@@ -795,7 +795,7 @@ static int builtin_path_id(UdevEvent *event, int argc, char *argv[]) {
                                 if (compat_path)
                                         path_prepend(&compat_path, "nvme-%s", nsid);
 
-                                if (device_in_subsystem(parent, "nvme-subsystem")) {
+                                if (device_in_subsystem(parent, "nvme-subsystem") > 0) {
                                         r = find_real_nvme_parent(dev, &dev_other_branch);
                                         if (r < 0)
                                                 return r;
@@ -807,7 +807,7 @@ static int builtin_path_id(UdevEvent *event, int argc, char *argv[]) {
                                 supported_parent = true;
                                 supported_transport = true;
                         }
-                } else if (device_in_subsystem(parent, "spi")) {
+                } else if (device_in_subsystem(parent, "spi") > 0) {
                         const char *sysnum;
 
                         if (sd_device_get_sysnum(parent, &sysnum) >= 0) {
@@ -838,7 +838,7 @@ static int builtin_path_id(UdevEvent *event, int argc, char *argv[]) {
          * devices do not expose their buses and do not provide a unique
          * and predictable name that way.
          */
-        if (device_in_subsystem(dev, "block") && !supported_transport)
+        if (device_in_subsystem(dev, "block") > 0 && !supported_transport)
                 return -ENOENT;
 
         add_id_with_usb_revision(event, path);
diff --git a/src/udev/udev-builtin-uaccess.c b/src/udev/udev-builtin-uaccess.c
index 7fbd91a5c2..9a9ba43b1c 100644
--- a/src/udev/udev-builtin-uaccess.c
+++ b/src/udev/udev-builtin-uaccess.c
@@ -5,12 +5,106 @@
 
 #include "sd-login.h"
 
+#include "acl-util.h"
 #include "device-util.h"
-#include "devnode-acl.h"
 #include "errno-util.h"
+#include "fd-util.h"
 #include "login-util.h"
 #include "udev-builtin.h"
 
+static int devnode_acl(int fd, uid_t uid) {
+        bool changed = false, found = false;
+        int r;
+
+        assert(fd >= 0);
+
+        _cleanup_(acl_freep) acl_t acl = NULL;
+        acl = acl_get_fd(fd);
+        if (!acl)
+                return -errno;
+
+        acl_entry_t entry;
+        for (r = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry);
+             r > 0;
+             r = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry)) {
+
+                acl_tag_t tag;
+                if (acl_get_tag_type(entry, &tag) < 0)
+                        return -errno;
+
+                if (tag != ACL_USER)
+                        continue;
+
+                if (uid > 0) {
+                        uid_t *u = acl_get_qualifier(entry);
+                        if (!u)
+                                return -errno;
+
+                        if (*u == uid) {
+                                acl_permset_t permset;
+                                if (acl_get_permset(entry, &permset) < 0)
+                                        return -errno;
+
+                                int rd = acl_get_perm(permset, ACL_READ);
+                                if (rd < 0)
+                                        return -errno;
+
+                                int wt = acl_get_perm(permset, ACL_WRITE);
+                                if (wt < 0)
+                                        return -errno;
+
+                                if (!rd || !wt) {
+                                        if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0)
+                                                return -errno;
+
+                                        changed = true;
+                                }
+
+                                found = true;
+                                continue;
+                        }
+                }
+
+                if (acl_delete_entry(acl, entry) < 0)
+                        return -errno;
+
+                changed = true;
+        }
+        if (r < 0)
+                return -errno;
+
+        if (!found && uid > 0) {
+                if (acl_create_entry(&acl, &entry) < 0)
+                        return -errno;
+
+                if (acl_set_tag_type(entry, ACL_USER) < 0)
+                        return -errno;
+
+                if (acl_set_qualifier(entry, &uid) < 0)
+                        return -errno;
+
+                acl_permset_t permset;
+                if (acl_get_permset(entry, &permset) < 0)
+                        return -errno;
+
+                if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0)
+                        return -errno;
+
+                changed = true;
+        }
+
+        if (!changed)
+                return 0;
+
+        if (acl_calc_mask(&acl) < 0)
+                return -errno;
+
+        if (acl_set_fd(fd, acl) < 0)
+                return -errno;
+
+        return 0;
+}
+
 static int builtin_uaccess(UdevEvent *event, int argc, char *argv[]) {
         sd_device *dev = ASSERT_PTR(ASSERT_PTR(event)->dev);
         int r, k;
@@ -26,14 +120,14 @@ static int builtin_uaccess(UdevEvent *event, int argc, char *argv[]) {
         if (!logind_running())
                 return 0;
 
-        const char *node;
-        r = sd_device_get_devname(dev, &node);
-        if (r < 0)
-                return log_device_error_errno(dev, r, "Failed to get device node: %m");
+        _cleanup_close_ int fd = sd_device_open(dev, O_CLOEXEC|O_RDWR);
+        if (fd < 0)
+                return log_device_error_errno(dev, fd, "Failed to open device node: %m");
 
         const char *seat;
-        if (sd_device_get_property_value(dev, "ID_SEAT", &seat) < 0)
-                seat = "seat0";
+        r = device_get_seat(dev, &seat);
+        if (r < 0)
+                return log_device_error_errno(dev, r, "Failed to get seat: %m");
 
         uid_t uid;
         r = sd_seat_get_active(seat, /* ret_session = */ NULL, &uid);
@@ -47,10 +141,7 @@ static int builtin_uaccess(UdevEvent *event, int argc, char *argv[]) {
                 goto reset;
         }
 
-        r = devnode_acl(node,
-                        /* flush = */ true,
-                        /* del = */ false, /* old_uid = */ 0,
-                        /* add = */ true, /* new_uid = */ uid);
+        r = devnode_acl(fd, uid);
         if (r < 0) {
                 log_device_full_errno(dev, r == -ENOENT ? LOG_DEBUG : LOG_ERR, r, "Failed to apply ACL: %m");
                 goto reset;
@@ -60,10 +151,7 @@ static int builtin_uaccess(UdevEvent *event, int argc, char *argv[]) {
 
 reset:
         /* Better be safe than sorry and reset ACL */
-        k = devnode_acl(node,
-                        /* flush = */ true,
-                        /* del = */ false, /* old_uid = */ 0,
-                        /* add = */ false, /* new_uid = */ 0);
+        k = devnode_acl(fd, /* uid = */ 0);
         if (k < 0)
                 RET_GATHER(r, log_device_full_errno(dev, k == -ENOENT ? LOG_DEBUG : LOG_ERR, k, "Failed to flush ACLs: %m"));
 
diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c
index 08ce26a0c5..957f028f17 100644
--- a/src/udev/udev-node.c
+++ b/src/udev/udev-node.c
@@ -506,7 +506,11 @@ static int device_get_devpath_by_devnum(sd_device *dev, char **ret) {
         if (r < 0)
                 return r;
 
-        return device_path_make_major_minor(device_in_subsystem(dev, "block") ? S_IFBLK : S_IFCHR, devnum, ret);
+        r = device_in_subsystem(dev, "block");
+        if (r < 0)
+                return r;
+
+        return device_path_make_major_minor(r > 0 ? S_IFBLK : S_IFCHR, devnum, ret);
 }
 
 int udev_node_update(sd_device *dev, sd_device *dev_old) {
diff --git a/src/udev/udev-watch.c b/src/udev/udev-watch.c
index 455ebd40e5..945bf0b8ca 100644
--- a/src/udev/udev-watch.c
+++ b/src/udev/udev-watch.c
@@ -199,12 +199,16 @@ static int synthesize_change(Manager *manager, sd_device *dev) {
         assert(manager);
         assert(dev);
 
-        const char *sysname;
-        r = sd_device_get_sysname(dev, &sysname);
+        r = device_sysname_startswith(dev, "dm-");
         if (r < 0)
                 return r;
+        if (r > 0)
+                return synthesize_change_one(dev, dev);
 
-        if (startswith(sysname, "dm-") || block_device_is_whole_disk(dev) <= 0)
+        r = block_device_is_whole_disk(dev);
+        if (r < 0)
+                return r;
+        if (r == 0)
                 return synthesize_change_one(dev, dev);
 
         _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
diff --git a/src/udev/udev-worker.c b/src/udev/udev-worker.c
index ba3c18c534..1f00606d87 100644
--- a/src/udev/udev-worker.c
+++ b/src/udev/udev-worker.c
@@ -47,17 +47,16 @@ int udev_get_whole_disk(sd_device *dev, sd_device **ret_device, const char **ret
         if (device_for_action(dev, SD_DEVICE_REMOVE))
                 goto irrelevant;
 
-        r = sd_device_get_sysname(dev, &val);
-        if (r < 0)
-                return log_device_debug_errno(dev, r, "Failed to get sysname: %m");
-
         /* Exclude the following devices:
          * For "dm-", see the comment added by e918a1b5a94f270186dca59156354acd2a596494.
          * For "md", see the commit message of 2e5b17d01347d3c3118be2b8ad63d20415dbb1f0,
          * but not sure the assumption is still valid even when partitions are created on the md
          * devices, surprisingly which seems to be possible, see PR #22973.
          * For "drbd", see the commit message of fee854ee8ccde0cd28e0f925dea18cce35f3993d. */
-        if (STARTSWITH_SET(val, "dm-", "md", "drbd"))
+        r = device_sysname_startswith(dev, "dm-", "md", "drbd");
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to check sysname: %m");
+        if (r > 0)
                 goto irrelevant;
 
         r = block_device_get_whole_disk(dev, &dev);
@@ -149,9 +148,7 @@ nolock:
 }
 
 static int worker_mark_block_device_read_only(sd_device *dev) {
-        _cleanup_close_ int fd = -EBADF;
-        const char *val;
-        int state = 1, r;
+        int r;
 
         assert(dev);
 
@@ -161,23 +158,31 @@ static int worker_mark_block_device_read_only(sd_device *dev) {
         if (!device_for_action(dev, SD_DEVICE_ADD))
                 return 0;
 
-        if (!device_in_subsystem(dev, "block"))
-                return 0;
-
-        r = sd_device_get_sysname(dev, &val);
+        r = device_in_subsystem(dev, "block");
         if (r < 0)
-                return log_device_debug_errno(dev, r, "Failed to get sysname: %m");
+                return r;
+        if (r == 0)
+                return 0;
 
         /* Exclude synthetic devices for now, this is supposed to be a safety feature to avoid modification
          * of physical devices, and what sits on top of those doesn't really matter if we don't allow the
          * underlying block devices to receive changes. */
-        if (STARTSWITH_SET(val, "dm-", "md", "drbd", "loop", "nbd", "zram"))
+        r = device_sysname_startswith(dev, "dm-", "md", "drbd", "loop", "nbd", "zram");
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to check sysname: %m");
+        if (r > 0)
                 return 0;
 
-        fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+        const char *val;
+        r = sd_device_get_devname(dev, &val);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get device node: %m");
+
+        _cleanup_close_ int fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
         if (fd < 0)
                 return log_device_debug_errno(dev, fd, "Failed to open '%s', ignoring: %m", val);
 
+        int state = 1;
         if (ioctl(fd, BLKROSET, &state) < 0)
                 return log_device_warning_errno(dev, errno, "Failed to mark block device '%s' read-only: %m", val);