named pipes memory leak?

Don Lewis truckman at
Tue Nov 11 12:09:12 PST 2003

On 11 Nov, Don Lewis wrote:
> On 11 Nov, Lukas Ertl wrote:

>> Sorry, I probably missed an important part: we're creating the FIFOs on
>> nullfs mounts - the test script works great on plain UFS mounts, but the
>> null layer seems to VREF the vnode once again, so v_usecount is 2, thus it
>> is missong the check in fifo_cleanup().
> Grrr ...  At least I didn't break this, our fifo implementation would
> have always leaked when used this way.
> Doing the cleanup in fifo_inactive() would have worked better in this
> case.  I think I figured out a way to make that work properly, but I
> really need to test it.
> Is there any particular reason that you are nuking and re-creating the
> fifo?  If you don't delete the fifo, the same sockets will get used each
> time.

Now that I've had some time to think about it, if you reuse the same
fifo, you'll run into the same problem that caused me to abandon my
previous fifo_inactive() version of the cleanup code, which is stale
data being left in the fifo after both ends have been closed.  You may
be stuck with plan B below ...

> As a workaround could you create a little mdfs to hold the fifo?

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