Re: [PATCH v2 11/11] tests/9pfs: add local Tmkdir test

[Christian Schoenebeck]

On Freitag, 2. Oktober 2020 16:32:55 CEST Greg Kurz wrote:
> On Fri, 2 Oct 2020 13:56:14 +0100
> 
> Daniel P. Berrangé <berrange@redhat.com> wrote:
> > On Fri, Oct 02, 2020 at 01:51:54PM +0200, Christian Schoenebeck wrote:
> > > This test case uses the 9pfs 'local' driver to create a directory
> > > and then checks if the expected directory was actually created
> > > (as real directory) on host side.
> > > 
> > > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > > ---
> > > 
> > >  tests/qtest/virtio-9p-test.c | 139 +++++++++++++++++++++++++++++++++++
> > >  1 file changed, 139 insertions(+)
> > > 
> > > diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> > > index af7e169d3a..93161a4b35 100644
> > > --- a/tests/qtest/virtio-9p-test.c
> > > +++ b/tests/qtest/virtio-9p-test.c
> > > @@ -18,6 +18,62 @@
> > > 
> > >  #define QVIRTIO_9P_TIMEOUT_US (10 * 1000 * 1000)
> > >  static QGuestAllocator *alloc;
> > > 
> > > +/*
> > > + * Used to auto generate new fids. Start with arbitrary high value to
> > > avoid + * collision with hard coded fids in basic test code.
> > > + */
> > > +static uint32_t fid_generator = 1000;
> > > +
> > > +static uint32_t genfid(void)
> > > +{
> > > +    return fid_generator++;
> > > +}
> > > +
> > > +/**
> > > + * Splits the @a in string by @a delim into individual (non empty)
> > > strings
> > > + * and outputs them to @a out. The output array @a out is NULL
> > > terminated.
> > > + *
> > > + * Output array @a out must be freed by calling split_free().
> > > + *
> > > + * @returns number of individual elements in output array @a out
> > > (without the + *          final NULL terminating element)
> > > + */
> > > +static int split(const char *in, const char *delim, char ***out)
> > > +{
> > > +    int n = 0, i = 0;
> > > +    char *tmp, *p;
> > > +
> > > +    tmp = g_strdup(in);
> > > +    for (p = strtok(tmp, delim); p != NULL; p = strtok(NULL, delim)) {
> > > +        if (strlen(p) > 0) {
> > > +            ++n;
> > > +        }
> > > +    }
> > > +    g_free(tmp);
> > > +
> > > +    *out = g_malloc0(n * sizeof(char *) + 1); /* last element NULL
> > > delimiter */> 
> > Surely this should be  (n + 1) * sizeof(char *), because the last
> > element still needs to be large enough to hold a pointer, not a
> > single extra byte.
> 
> If you decide to keep this split() function, maybe use g_new0(char *, n + 1)
> ? This buys you the math and does type checking as an extra.

Yes, that was my plan B.

But if Daniel sais its long-term safe to pass a re-shuffled array to 
g_strfreev(), well then I go that route.

Best regards,
Christian Schoenebeck