+ if (last->ec - first->ec < WL_FREE_MAX_DIFF) {
+ e = rb_entry(root->rb_node, struct ubi_wl_entry, u.rb);
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+ /* If no fastmap has been written and this WL entry can be used
+ * as anchor PEB, hold it back and return the second best
+ * WL entry such that fastmap can use the anchor PEB later. */
+ if (e && !ubi->fm_disabled && !ubi->fm &&
+ e->pnum < UBI_FM_MAX_START)
+ e = rb_entry(rb_next(root->rb_node),
+ struct ubi_wl_entry, u.rb);
+#endif
+ } else
+ e = find_wl_entry(ubi, root, WL_FREE_MAX_DIFF/2);
+
+ return e;
+}
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+/**
+ * find_anchor_wl_entry - find wear-leveling entry to used as anchor PEB.
+ * @root: the RB-tree where to look for
+ */
+static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root)
+{
+ struct rb_node *p;
+ struct ubi_wl_entry *e, *victim = NULL;
+ int max_ec = UBI_MAX_ERASECOUNTER;
+
+ ubi_rb_for_each_entry(p, e, root, u.rb) {
+ if (e->pnum < UBI_FM_MAX_START && e->ec < max_ec) {
+ victim = e;
+ max_ec = e->ec;
+ }
+ }
+
+ return victim;
+}
+
+static int anchor_pebs_avalible(struct rb_root *root)
+{
+ struct rb_node *p;
+ struct ubi_wl_entry *e;
+
+ ubi_rb_for_each_entry(p, e, root, u.rb)
+ if (e->pnum < UBI_FM_MAX_START)
+ return 1;
+
+ return 0;
+}
+
+/**
+ * ubi_wl_get_fm_peb - find a physical erase block with a given maximal number.
+ * @ubi: UBI device description object
+ * @anchor: This PEB will be used as anchor PEB by fastmap
+ *
+ * The function returns a physical erase block with a given maximal number
+ * and removes it from the wl subsystem.
+ * Must be called with wl_lock held!
+ */
+struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor)
+{
+ struct ubi_wl_entry *e = NULL;
+
+ if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1))
+ goto out;
+
+ if (anchor)
+ e = find_anchor_wl_entry(&ubi->free);
+ else
+ e = find_mean_wl_entry(ubi, &ubi->free);
+
+ if (!e)
+ goto out;
+
+ self_check_in_wl_tree(ubi, e, &ubi->free);
+
+ /* remove it from the free list,
+ * the wl subsystem does no longer know this erase block */
+ rb_erase(&e->u.rb, &ubi->free);
+ ubi->free_count--;
+out:
+ return e;
+}
+#endif
+
+/**
+ * __wl_get_peb - get a physical eraseblock.
+ * @ubi: UBI device description object
+ *
+ * This function returns a physical eraseblock in case of success and a
+ * negative error code in case of failure.
+ */
+static int __wl_get_peb(struct ubi_device *ubi)
+{
+ int err;
+ struct ubi_wl_entry *e;