Re: [Qemu-devel] [PATCH v6 2/4] 9p: Added virtfs option 'multidevs=remap|forbid|warn'

[Christian Schoenebeck via Qemu-devel <qemu-devel@nongnu.org>]

On Montag, 2. September 2019 12:16:26 CEST Greg Kurz wrote:
> > > > @@ -571,22 +572,109 @@ static void coroutine_fn virtfs_reset(V9fsPDU
> > > > *pdu)
> > > > 
> > > >                                  P9_STAT_MODE_NAMED_PIPE |   \
> > > >                                  P9_STAT_MODE_SOCKET)
> > > > 
> > > > -/* This is the algorithm from ufs in spfs */
> > > > +
> > > > +/* creative abuse of tb_hash_func7, which is based on xxhash */
> > > > +static uint32_t qpp_hash(QppEntry e)
> > > > +{
> > > > +    return qemu_xxhash7(e.ino_prefix, e.dev, 0, 0, 0);
> > > > +}
> > > > +
> > > > +static bool qpp_lookup_func(const void *obj, const void *userp)
> > > > +{
> > > > +    const QppEntry *e1 = obj, *e2 = userp;
> > > > +    return e1->dev == e2->dev && e1->ino_prefix == e2->ino_prefix;
> > > > +}
> > > > +
> > > > +static void qpp_table_remove(void *p, uint32_t h, void *up)
> > > > +{
> > > > +    g_free(p);
> > > > +}
> > > > +
> > > > +static void qpp_table_destroy(struct qht *ht)
> > > > +{
> > > > +    qht_iter(ht, qpp_table_remove, NULL);
> > > > +    qht_destroy(ht);
> > > > +}
> > > 
> > > Ok to have a function for this instead of open-coding but I'd
> > > like to see qpp_table_init() for consistency.
> > 
> > Well, these are just qht_init() one-liners, but if you really want to have
> > dedicated, local init functions for them, okay.
> 
> Yeah, even if it's a one-liner, I prefer consistency. Alternatively, with
> an idempotent v9fs_device_unrealize_common() like in [1], you'd have
> only one user for qpp_table_destroy() and you can open-code it. This
> would address my consistency concern even better :)
> 
> [1]
> https://github.com/gkurz/qemu/commit/7fc4c49e910df2e155b36bf0a05de9209bd92d

I'll rather add qpp_table_init() then, because grouping the two calls 
qht_iter() and qht_destroy() together to a dedicated function 
qpp_table_destroy() still makes sense semantically IMO.