On Wed, Apr 12, 2023 at 01:18:26PM +1000, Dave Chinner wrote: > Right. It's not entirely simple to store metadata on disk beyond EOF > in XFS because of all the assumptions throughout the IO path and > allocator interfaces that it can allocate space beyond EOF at will > and something else will clean it up later if it is not needed. This > impacts on truncate, delayed allocation, writeback, IO completion, > EOF block removal on file close, background garbage collection, > ENOSPC/EDQUOT driven space freeing, etc. Some of these things cross > over into iomap infrastructure, too. To me that actually makes it easier to support the metadata beyond i_size. Remember that the file is immutable after add fsverity hash is added. So basically we just need to skip freeing the eofblocks if that flag is set.
