On Thu, Jan 20, 2011 at 10:49 AM, Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> wrote: > On Thu, 2011-01-20 at 10:37 +1100, Nick Piggin wrote: >> On Thu, Jan 20, 2011 at 10:31 AM, Trond Myklebust >> <Trond.Myklebust@xxxxxxxxxx> wrote: >> > On Thu, 2011-01-20 at 10:26 +1100, Nick Piggin wrote: >> >> On Thu, Jan 20, 2011 at 10:25 AM, Trond Myklebust >> >> >> > Also, why is EIO the correct reply when no bytes were read/written? Why >> >> > shouldn't the VFS aio code be able to cope with a zero byte reply? >> >> >> >> What would it do? >> > >> > Just return that zero byte reply to userland. >> > >> > zero bytes is a valid reply for ordinary read() and write(), so why >> > should we have to do anything different for aio_read()/aio_write()? >> >> It doesn't give userspace much to do. zero reply from read means >> EOF. Zero reply from write is pretty useless, I don't think we do it >> in the buffered write path -- we either ensure we write at least >> something or have a meaningful error to return. > > zero reply from read means EOF _or_ user supplied a zero length buffer. > > zero reply from write may also be useless, but it is a valid value. It > can simply mean the user supplied a zero length buffer. OK, yes. I'm ignoring zero length request. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
