On Tue, Mar 18, 2025 at 03:35:42PM +0800, Zhang Yi wrote: > Users can check the disk support of unmap write zeroes command by > querying: > > /sys/block/<disk>/queue/write_zeroes_unmap No, that is not in any way a good user interface. Users need to be able to query this on a per-file basis. > Finally, this flag should not be specified in conjunction with the > FALLOC_FL_KEEP_SIZE since allocating written extents beyond file EOF is > not permitted, and filesystems that always require out-of-place writes > should not support this flag since they still need to allocated new > blocks during subsequent overwrites. Should not or can't? You're returning an error if this happens, so it doesn't look like should is the right word here.
