According to https://unix.stackexchange.com/a/501454/674,
parted's resizepart does not care about the filesystem at all. It just changes the partition table to specify a new location where the partition now ends. It does not overwrite anything at or near that location. After modifying the partition table, it will signal the kernel that the partition table has been changed. The kernel will read the new table and apply it if possible.
resize2fs change the size of a file system? Does it also do it in a similar way to
parted resizepart? Specially:
https://unix.stackexchange.com/a/231623/674 says it extends a file system, by
writing additional filesystem metadata to the newly available storage.
What filesystem metadata does it write to "the newly available storage"? Does writing to "the newly available storage" in the sense of writing zeros all over "the newly available storage"? Or does it change some value stored in the superblock of the file system only?
https://unix.stackexchange.com/a/231623/674 says it shrinks a file system
by moving both filesystem metadata and your data around.
Does it not write some "filesystem metadata" to somewhere?