ext4: make running and commit transaction have their own freed_data_list

When releasing space in jbd, we traverse s_freed_data_list to get the
free range belonging to the current commit transaction. In extreme cases,
the time spent may not be small, and we have observed cases exceeding
10ms. This patch makes running and commit transactions manage their own
free_data_list respectively, eliminating unnecessary traversal.

And in the callback phase of the commit transaction, no one will touch
it except the jbd thread itself, so s_md_lock is no longer needed.

Signed-off-by: Jinke Han <hanjinke.666@bytedance.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20230612124017.14115-1-hanjinke.666@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>