dm kcopyd: add dm_kcopyd_zero to zero an area
This patch introduces dm_kcopyd_zero() to make it easy to use
kcopyd to write zeros into the requested areas instead
instead of copying. It is implemented by passing a NULL
copying source to dm_kcopyd_copy().
The forthcoming thin provisioning target uses this.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h
index 5e54458..47d9d37 100644
--- a/include/linux/dm-kcopyd.h
+++ b/include/linux/dm-kcopyd.h
@@ -57,5 +57,9 @@
dm_kcopyd_notify_fn fn, void *context);
void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err);
+int dm_kcopyd_zero(struct dm_kcopyd_client *kc,
+ unsigned num_dests, struct dm_io_region *dests,
+ unsigned flags, dm_kcopyd_notify_fn fn, void *context);
+
#endif /* __KERNEL__ */
#endif /* _LINUX_DM_KCOPYD_H */