On Mon, Apr 06, 2020 at 06:40:57PM +0200, Dominique Martinet wrote: > The use-case here is stuff like reading from synthetic files (think fake > pipes) where data comes in like a pipe and one would want read to return > as soon as data is available. > Just thinking out loud it might be possible to make pipes go through the > server and somewhat work, but this might bring its own share of other > problems and existing programs would need to be changed (e.g. wmii's > synthetic filesystem exposes this kind of files as well as regular > files, which works fine for their userspace client (wmiir) but can't > really be used with a linux client) > Anyway, I agree looking at O_NONBLOCK for that isn't obvious. > I agree with the usecase here and posix allows short reads regardless of > the flag so the behaviour is legal either way ; the filesystem is > allowed to return whenever it wants on a whim - let's just add some docs > as you suggest unless Sergey has something to add. In fact i would prefer disabling the full reads unconditionally, but AFAIR some userspace programs might interpret a short read as EOF (and also would need to check the logic that motivated the kernel-side looping). -- () ascii ribbon campaign - against html mail /\ http://arc.pasp.de/ - against proprietary attachments
