lkml.org 
[lkml]   [2020]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [GIT PULL] 9p update for 5.7
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

\
 
 \ /
  Last update: 2020-04-07 04:26    [W:0.167 / U:0.748 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site