Test case misc/038 uses hard coded backup slot number, this means if we
change how many transactions we commit during mkfs, it will immediately
break the tests.
Such hard coded tests will be a big pain for later btrfs-progs updates.
Update it with runtime backup slot search.
Such search is done by using current filesystem generation as a search
target and grab the slot number.
By this, no matter how many transactions we commit during mkfs, the test
case should be able to handle it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
db8c9a420c