+static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
+ const u8 *a2, unsigned a2_len)
+{
+ if (!a2_len) /* User string is Empty means don't care */
+ return true;
+
+ if (a1_len != a2_len)
+ return false;
+
+ return 0 == memcmp(a1, a2, a1_len);
+}
+
+struct find_oud_t {
+ const struct osd_dev_info *odi;
+ struct device *dev;
+ struct osd_uld_device *oud;
+} ;
+
+int _mach_odi(struct device *dev, void *find_data)
+{
+ struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
+ class_dev);
+ struct find_oud_t *fot = find_data;
+ const struct osd_dev_info *odi = fot->odi;
+
+ if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
+ odi->systemid, odi->systemid_len) &&
+ _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
+ odi->osdname, odi->osdname_len)) {
+ OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
+ odi->systemid_len, odi->osdname_len);
+ fot->oud = oud;
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/* osduld_info_lookup - Loop through all devices, return the requested osd_dev.
+ *
+ * if @odi->systemid_len and/or @odi->osdname_len are zero, they act as a don't
+ * care. .e.g if they're both zero /dev/osd0 is returned.
+ */
+struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
+{
+ struct find_oud_t find = {.odi = odi};
+
+ find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
+ if (likely(find.dev)) {
+ struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
+
+ if (unlikely(!odh)) {
+ put_device(find.dev);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ odh->od = find.oud->od;
+ odh->oud = find.oud;
+
+ return &odh->od;
+ }
+
+ return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL(osduld_info_lookup);
+