On Fri, Dec 13, 2024 at 04:56:38PM -0800, Darrick J. Wong wrote: > > > "If you receive -EBADMAP, then call fallocate(FALLOC_FL_MAKE_OVERWRITE) > > > to force all the mappings to pure overwrites." > > > > Ewwwwwwwwwwwwwwwwwwwww. > > > > That's not a sane API in any way. > > Oh I know, I'd much rather stick to the view that block untorn writes > are a means for programs that only ever do IO in large(ish) blocks to > take advantage of a hardware feature that also wants those large > blocks. I (vaguely) agree ith that. > And only if the file mapping is in the correct state, and the > program is willing to *maintain* them in the correct state to get the > better performance. I kinda agree with that, but the maintain is a bit hard as general rule of thumb as file mappings can change behind the applications back. So building interfaces around the concept that there are entirely stable mappings seems like a bad idea. > I don't want xfs to grow code to write zeroes to > mapped blocks just so it can then write-untorn to the same blocks. Agreed.
