File system locking when snapshotting?

I have not seen any explicit mention of file system locking when doing a snapshot. I have been looking at https://github.com/alestic/ec2-consistent-snapshot as a possible solution for snapshotting AWS EBS volumes. That program is backed with a lot of discussion about file system locking to try to achieve consistent backups. I prefer something like convoy which I might be able to use in AWS as well as on-premise, but I’d feel better if there was some attempt at consistency when taking snapshots. Or is this really my concern?