A possible step toward integrity measurement for Fedora

fs-verity is mainly a way of hashing files, while IMA is mainly a policy for what to do with file hashes.

fs-verity does have optional support for storing signatures with files and having the kernel verify that all fs-verity files are signed by a trusted key. This is much simpler than an IMA policy but also much less flexible; e.g., userspace still needs to check which files have fs-verity enabled. It's really more a proof-of-concept, which happens to be enough for some users who don't want to use IMA.

At some point it's likely that IMA will support fs-verity hashes, so that IMA and fs-verity can be used together. They're not mutually exclusive.