[lvm-devel] [PATCH] Make _init_rand() thread safe - use rand_r() instead of rand().
Dave Wysochanski
dwysocha at redhat.com
Sat Dec 6 03:27:44 UTC 2008
On Sat, 2008-12-06 at 02:26 +0000, Alasdair G Kergon wrote:
> On Fri, Dec 05, 2008 at 05:52:45PM -0500, Dave Wysochanski wrote:
> > This random code is for temp files. Other code which uses
> > /dev/urandom is used for uuids. Should we be using /dev/urandom
> > everywhere?
>
> Well look what we are using it for - we are not relying on the randomness
> - if the filename is already in use, we just try another one - so it's
> nothing to worry about.
>
> > + if (!create_temp_name(temp_dir, temp_file, sizeof(temp_file), &fd,
> > + &vg->cmd->rand_seed)) {
>
> Just pass 'cmd'? (as first arg)
>
I originally did that but then thought it might be better to avoid
polluting lvm-file.c with includes just so I could dereference cmd.
> Does this patch do enough to ensure each thread will get a different value of
> 'seed'?
>
Probably not. A better seed might use /dev/urandom or gettimeofday()
with tv_usec granularity.
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