* Christoph Hellwig: > On Mon, Jul 29, 2024 at 08:52:00PM +0200, Florian Weimer wrote: >> > supporting fallocate. That's is generally the wrong thing to do, and >> > spectacularly wrong for file systems that write out of place. >> >> In this case, the file system could return another error code besides >> EOPNOTSUPP. > > What error code would that be and how do applications know about it? Anything that's not EOPNOTSUPP will do. EMEDIUMTYPE or ENOTBLK might do it. Any of the many STREAMS error codes could also be re-used quite safely because Linux doesn't do STREAMS. If you remove the fallback code, applications need to be taught about EOPNOTSUPP, so that doesn't really make a difference. Still it needs testing. It's possible that key software doesn't expect posix_fallocate to fail. Thanks, Florian
