lvconvert: libdm RAID API compatibility versioning

Commit 27384c52cf6a lowered the maximum number of devices
back to 64 for compatibility.

Because more members have been added to the API in
'struct dm_tree_node_raid_params *', we have to version
the public libdm RAID API to not break any existing users.

Changes:

- keep the previous 'struct dm_tree_node_raid_params' and
  dm_tree_node_add_raid_target_with_params()/dm_tree_node_add_raid_target()
  in order to expose the already released public RAID API

- introduce 'struct dm_tree_node_raid_params_v2' and additional functions
  dm_tree_node_add_raid_target_with_params_v2()/dm_tree_node_add_raid_target_v2()
  to be used by the new lvm2 lib reshape extentions

With this new API, the bitfields for rebuild/writemostly legs in
'struct dm_tree_node_raid_params_v2' can be raised to 256 bits
again (253 legs maximum supported in MD kernel).

Mind that we can limit the maximum usable number via the
DEFAULT_RAID{1}_MAX_IMAGES definition in defaults.h.

Related: rhbz834579
Related: rhbz1191935
Related: rhbz1191978

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/raid/raid.c b/lib/raid/raid.c
index 59db43793..9ab2e6c6f 100644
--- a/lib/raid/raid.c
+++ b/lib/raid/raid.c
@@ -242,7 +242,7 @@ static int _raid_add_target_line(struct dev_manager *dm __attribute__((unused)),
 	uint64_t flags = 0;
 	uint64_t rebuilds[RAID_BITMAP_SIZE];
 	uint64_t writemostly[RAID_BITMAP_SIZE];
-	struct dm_tree_node_raid_params params;
+	struct dm_tree_node_raid_params_v2 params;
 
 	memset(&params, 0, sizeof(params));
 	memset(&rebuilds, 0, sizeof(rebuilds));
@@ -333,7 +333,7 @@ static int _raid_add_target_line(struct dev_manager *dm __attribute__((unused)),
 	params.stripe_size = seg->stripe_size;
 	params.flags = flags;
 
-	if (!dm_tree_node_add_raid_target_with_params(node, len, &params))
+	if (!dm_tree_node_add_raid_target_with_params_v2(node, len, &params))
 		return_0;
 
 	return add_areas_line(dm, seg, node, 0u, seg->area_count);