repart: report vendor/model/subsystem fields in ListCandidateDevices

Prompted by: #39435

src/shared/blockdev-list.c

@@ -8,6 +8,8 @@
 #include "blockdev-util.h"
 #include "device-private.h"
 #include "device-util.h"
+#include "errno-util.h"
+#include "string-util.h"
 #include "strv.h"
 #include "terminal-util.h"
 
@@ -16,6 +18,9 @@ void block_device_done(BlockDevice *d) {
 
         d->node = mfree(d->node);
         d->symlinks = strv_free(d->symlinks);
+        d->model = mfree(d->model);
+        d->vendor = mfree(d->vendor);
+        d->subsystem = mfree(d->subsystem);
  }
 
 void block_device_array_free(BlockDevice *d, size_t n_devices) {
@@ -26,6 +31,61 @@ void block_device_array_free(BlockDevice *d, size_t n_devices) {
         free(d);
 }
 
+static int blockdev_get_prop(sd_device *d, const char *prop1, const char *prop2, char **ret_value) {
+        int r, ret = 0;
+
+        assert(d);
+        assert(prop1);
+        assert(ret_value);
+
+        FOREACH_STRING(prop, prop1, prop2) {
+                const char *m = NULL;
+                r = sd_device_get_property_value(d, prop, &m);
+                if (r < 0 && r != -ENOENT)
+                        RET_GATHER(ret, log_device_debug_errno(d, r, "Failed to acquire '%s' from device, ignoring: %m", prop));
+                else if (!isempty(m))
+                        return strdup_to(ret_value, m);
+        }
+
+        return ret < 0 ? ret : -ENOENT;
+}
+
+static int blockdev_get_subsystem(sd_device *d, char **ret_subsystem) {
+        int r;
+
+        assert(d);
+        assert(ret_subsystem);
+
+        /* We prefer the explicitly set block device subsystem property, because if it is set it's generally
+         * the most useful. If it's not set we'll look for the subsystem of the first parent device that
+         * isn't of subsystem 'block'. The former covers 'virtual' block devices such as loopback, device
+         * mapper, zram, while the latter covers physical block devices such as USB or NVME. */
+
+        r = blockdev_get_prop(d, "ID_BLOCK_SUBSYSTEM", /* prop2= */ NULL, ret_subsystem);
+        if (r >= 0)
+                return r;
+
+        int ret = r != -ENOENT ? r : 0;
+        sd_device *q = d;
+        for (;;) {
+                r = sd_device_get_parent(q, &q);
+                if (r < 0) {
+                        if (r != -ENOENT)
+                                RET_GATHER(ret, log_device_debug_errno(q, r, "Failed to get parent device, ignoring: %m"));
+                        break;
+                }
+
+                const char *s = NULL;
+                r = sd_device_get_subsystem(q, &s);
+                if (r < 0)
+                        RET_GATHER(ret, log_device_debug_errno(q, r, "Failed to get subsystem of device, ignoring: %m"));
+                else if (!isempty(s) && !streq(s, "block"))
+                        return strdup_to(ret_subsystem, s);
+        }
+
+        return ret < 0 ? ret : -ENOENT;
+}
+
 int blockdev_list(BlockDevListFlags flags, BlockDevice **ret_devices, size_t *ret_n_devices) {
         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
         int r;
@@ -128,6 +188,13 @@ int blockdev_list(BlockDevListFlags flags, BlockDevice **ret_devices, size_t *re
                         strv_sort(list);
                 }
 
+                _cleanup_free_ char *model = NULL, *vendor = NULL, *subsystem = NULL;
+                if (FLAGS_SET(flags, BLOCKDEV_LIST_METADATA)) {
+                        (void) blockdev_get_prop(dev, "ID_MODEL_FROM_DATABASE", "ID_MODEL", &model);
+                        (void) blockdev_get_prop(dev, "ID_VENDOR_FROM_DATABASE", "ID_VENDOR", &vendor);
+                        (void) blockdev_get_subsystem(dev, &subsystem);
+                }
+
                 if (ret_devices) {
                         uint64_t diskseq = UINT64_MAX;
                         r = sd_device_get_diskseq(dev, &diskseq);
@@ -146,6 +213,9 @@ int blockdev_list(BlockDevListFlags flags, BlockDevice **ret_devices, size_t *re
                                 .symlinks = TAKE_PTR(list),
                                 .diskseq = diskseq,
                                 .size = size,
+                                .model = TAKE_PTR(model),
+                                .vendor = TAKE_PTR(vendor),
+                                .subsystem = TAKE_PTR(subsystem),
                         };
 
                 } else {