+void *dm_per_bio_data(struct bio *bio, size_t data_size)
+{
+ struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
+ if (!tio->inside_dm_io)
+ return (char *)bio - offsetof(struct dm_target_io, clone) - data_size;
+ return (char *)bio - offsetof(struct dm_target_io, clone) - offsetof(struct dm_io, tio) - data_size;
+}
+EXPORT_SYMBOL_GPL(dm_per_bio_data);
+
+struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
+{
+ struct dm_io *io = (struct dm_io *)((char *)data + data_size);
+ if (io->magic == DM_IO_MAGIC)
+ return (struct bio *)((char *)io + offsetof(struct dm_io, tio) + offsetof(struct dm_target_io, clone));
+ BUG_ON(io->magic != DM_TIO_MAGIC);
+ return (struct bio *)((char *)io + offsetof(struct dm_target_io, clone));
+}
+EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data);
+
+unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
+{
+ return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
+}
+EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
+