svn commit: r256377 - in head: etc/defaults etc/rc.d share/examples/kld/random_adaptor share/man/man4 sys/boot/forth sys/conf sys/dev/glxsb sys/dev/hifn sys/dev/random sys/dev/rndtest sys/dev/safe ...

[Ian Lepore]

On Sun, 2013-10-13 at 16:18 +0100, Mark R V Murray wrote:
> On 13 Oct 2013, at 16:13, Konstantin Belousov <kostikbel at gmail.com> wrote:
> > Surely this works, thank you. The rwfile.c content probably should be
> > taken under the #ifdef RANDOM_RWFILE.
> 
> OK - thanks for the feedback!
> 
> > But I do not see much use for the randomdev_read_file() and
> > randomdev_write_file() functions. It would be better to directly code
> > the VFS calls in the random_harvestq_cache(). For one thing, it would
> > eliminate unneccessary close and open of the entropy file.
> 
> There is some uncertainty about the future of that code, so I want
> to keep it that way for now. Writing files from the kernel is making so@
> very uncomfortable, and there is too much scope for error there.
> 

Indeed, it makes me nervous too, as a heavy user of readonly root
filesystems.  If writing this file is so critical that it has to be done
by the kernel, then what happens when it fails?  Right now it prints an
error and continues -- if it is not so critical that failure means
panic, then why is the kernel doing it at all?

Why is the file even in the root filesystem?  /var/db seems to be the
right place for a transient file needed by the system.

Speaking of errors, that might include things like the current code
calling vn_close() with the FREAD flag on a file open for writing.

-- Ian

> We'll settle it down properly in 11.*.
> 
> M