svn commit: r273958 - head/sys/dev/random

[Konstantin Belousov]

On Mon, Nov 03, 2014 at 11:53:26AM +1100, Bruce Evans wrote:
> On Sun, 2 Nov 2014, Ian Lepore wrote:
> 
> > On Sun, 2014-11-02 at 12:27 -0800, Xin Li wrote:
> >> -----BEGIN PGP SIGNED MESSAGE-----
> >> Hash: SHA512
> >>
> >> Hi, Mark,
> >>
> >> I'd like to propose the attached patch for review.  It replaces
> >> tsleep's with sx_sleep's, then checks the return value and quit the loop.
> >
> > It still doesn't handle the partial read/write case Kostik mentioned,
> > but there are plenty of other drivers that don't get that right.
> 
> Returning an error for a partial read is good enough for random devices,
> since there is no problem with discarding the input.  Upper layers are
> still broken, so this (discarding the input is what happens automatically
> except for ERESTART, EINTR and EWOULDBLOCK.
But usermode buffer is already partially accessed and modified.
Yes, I am picky about it after vn_io_fault() work.

Also, it reminds me about the pipe EPIPE fix.  I will commit it in a
minute, finally.