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Diffstat (limited to 'drivers/md/persistent-data/dm-btree-internal.h')
-rw-r--r--drivers/md/persistent-data/dm-btree-internal.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index b1788853a355..893edb426dba 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -144,4 +144,17 @@ extern struct dm_block_validator btree_node_validator;
extern void init_le64_type(struct dm_transaction_manager *tm,
struct dm_btree_value_type *vt);
+/*
+ * This returns a shadowed btree leaf that you may modify. In practise
+ * this means overwrites only, since an insert could cause a node to
+ * be split. Useful if you need access to the old value to calculate the
+ * new one.
+ *
+ * This only works with single level btrees. The given key must be present in
+ * the tree, otherwise -EINVAL will be returned.
+ */
+int btree_get_overwrite_leaf(struct dm_btree_info *info, dm_block_t root,
+ uint64_t key, int *index,
+ dm_block_t *new_root, struct dm_block **leaf);
+
#endif /* DM_BTREE_INTERNAL_H */