There is no support for writing multiple xattrs in one transaction.
There is no support for writing multiple xattrs and file contents in one transaction.
Journaled filesystems that immediately flush xattrs to the journal do have atomic writes of single xattrs; so you'd need to stuff all data in one xattr value and serialize/deserialize (with e.g JSON, or potentially Arrow IPC with Feather ~mmap'd from xattrs (edit: but getxattr() doesn't support mmap. And xattr storage limits: EXT4: 4K, XFS: 64k, BTRFS: 16K)
There is no support for writing multiple xattrs and file contents in one transaction.
Journaled filesystems that immediately flush xattrs to the journal do have atomic writes of single xattrs; so you'd need to stuff all data in one xattr value and serialize/deserialize (with e.g JSON, or potentially Arrow IPC with Feather ~mmap'd from xattrs (edit: but getxattr() doesn't support mmap. And xattr storage limits: EXT4: 4K, XFS: 64k, BTRFS: 16K)
Atomicity (database systems) https://en.wikipedia.org/wiki/Atomicity_(database_systems)