Probably depends a lot on what options you had enabled on BTRFS. Metadata (i.e. what files are stored where) is normally replicated so you may be able to rebuild the information.
Step 1 is always to copy the filesystem somewhere else, and then work on the copy. That way, if you screw up, you can always make a new copy and start over. Don’t write anything to the drive you’re trying to fix. Always work on the copy. In fact, once you’ve made the copy, disconnect the original.
Probably depends a lot on what options you had enabled on BTRFS. Metadata (i.e. what files are stored where) is normally replicated so you may be able to rebuild the information.
Step 1 is always to copy the filesystem somewhere else, and then work on the copy. That way, if you screw up, you can always make a new copy and start over. Don’t write anything to the drive you’re trying to fix. Always work on the copy. In fact, once you’ve made the copy, disconnect the original.