btrfs: reloc: use wrapper to replace open-coded edge linking
Since backref_edge is used to connect upper and lower backref nodes, and
needs to access both nodes, some code can look pretty nasty:
list_add_tail(&edge->list[LOWER], &cur->upper);
The above code will link @cur to the LOWER side of the edge, while both
"LOWER" and "upper" words show up. This can sometimes be very confusing
for reader to grasp.
This patch introduces a new wrapper, link_backref_edge(), to handle the
linking behavior. Which also has extra ASSERT() to ensure caller won't
pass wrong nodes.
Also, this updates the comment of related lists of backref_node and
backref_edge, to make it more clear that each list points to what.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
1 file changed