Re: [PATCH v8 1/7] tests/virtio-9p: added split readdir tests

[Christian Schoenebeck]

On Mittwoch, 29. Juli 2020 17:42:54 CEST Greg Kurz wrote:
> On Wed, 29 Jul 2020 10:10:23 +0200
> 
> Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > The previous, already existing 'basic' readdir test simply used a
> > 'count' parameter big enough to retrieve all directory entries with a
> > single Treaddir request.
> > 
> > In the 3 new 'split' readdir tests added by this patch, directory
> > entries are retrieved, split over several Treaddir requests by picking
> > small 'count' parameters which force the server to truncate the
> > response. So the test client sends as many Treaddir requests as
> > necessary to get all directory entries.
> > 
> > The following 3 new tests are added (executed in this sequence):
> > 
> > 1. Split readdir test with count=512
> > 2. Split readdir test with count=256
> > 3. Split readdir test with count=128
> > 
> > This test case sequence is chosen because the smaller the 'count' value,
> > the higher the chance of errors in case of implementation bugs on server
> > side.
> > 
> > Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > ---
> 
> The existing fs_readdir() function for the 'basic' test is a subset
> of the new fs_readdir_split() introduced by this patch (quite visible
> if you sdiff the code).
> 
> To avoid code duplication, I would have probably tried to do the changes
> in fs_readdir() and implement the 'basic' test as:
> 
> static void fs_readdir_basic(void *obj, void *data,
>                              QGuestAllocator *t_alloc)
> {
>     /*
>      * submit count = msize - 11, because 11 is the header size of Rreaddir
>      */
>     fs_readdir(obj, data, t_alloc, P9_MAX_SIZE - 11);
> }

You are right of course; there is code duplication. My thought was to preserve 
the simple readdir test code (at least at this initial stage) as it is really 
very simple and easy to understand.

The split readdir test code is probably already a tad more tedious to read.

I keep it in mind though and probably deduplicate this test code a bit later 
on. But I think it makes sense to start off with this version for now.

> but anyway this looks good to me so:
> 
> Reviewed-by: Greg Kurz <groug@kaod.org>

Thanks!

> >  tests/qtest/virtio-9p-test.c | 108 +++++++++++++++++++++++++++++++++++
> >  1 file changed, 108 insertions(+)
> > 
> > diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> > index 2167322985..de30b717b6 100644
> > --- a/tests/qtest/virtio-9p-test.c
> > +++ b/tests/qtest/virtio-9p-test.c
> > @@ -578,6 +578,7 @@ static bool fs_dirents_contain_name(struct V9fsDirent
> > *e, const char* name)> 
> >      return false;
> >  
> >  }
> > 
> > +/* basic readdir test where reply fits into a single response message */
> > 
> >  static void fs_readdir(void *obj, void *data, QGuestAllocator *t_alloc)
> >  {
> >  
> >      QVirtio9P *v9p = obj;
> > 
> > @@ -631,6 +632,89 @@ static void fs_readdir(void *obj, void *data,
> > QGuestAllocator *t_alloc)> 
> >      g_free(wnames[0]);
> >  
> >  }
> > 
> > +/* readdir test where overall request is split over several messages */
> > +static void fs_readdir_split(void *obj, void *data, QGuestAllocator
> > *t_alloc, +                             uint32_t count)
> > +{
> > +    QVirtio9P *v9p = obj;
> > +    alloc = t_alloc;
> > +    char *const wnames[] = { g_strdup(QTEST_V9FS_SYNTH_READDIR_DIR) };
> > +    uint16_t nqid;
> > +    v9fs_qid qid;
> > +    uint32_t nentries, npartialentries;
> > +    struct V9fsDirent *entries, *tail, *partialentries;
> > +    P9Req *req;
> > +    int fid;
> > +    uint64_t offset;
> > +
> > +    fs_attach(v9p, NULL, t_alloc);
> > +
> > +    fid = 1;
> > +    offset = 0;
> > +    entries = NULL;
> > +    nentries = 0;
> > +    tail = NULL;
> > +
> > +    req = v9fs_twalk(v9p, 0, fid, 1, wnames, 0);
> > +    v9fs_req_wait_for_reply(req, NULL);
> > +    v9fs_rwalk(req, &nqid, NULL);
> > +    g_assert_cmpint(nqid, ==, 1);
> > +
> > +    req = v9fs_tlopen(v9p, fid, O_DIRECTORY, 0);
> > +    v9fs_req_wait_for_reply(req, NULL);
> > +    v9fs_rlopen(req, &qid, NULL);
> > +
> > +    /*
> > +     * send as many Treaddir requests as required to get all directory
> > +     * entries
> > +     */
> > +    while (true) {
> > +        npartialentries = 0;
> > +        partialentries = NULL;
> > +
> > +        req = v9fs_treaddir(v9p, fid, offset, count, 0);
> > +        v9fs_req_wait_for_reply(req, NULL);
> > +        v9fs_rreaddir(req, &count, &npartialentries, &partialentries);
> > +        if (npartialentries > 0 && partialentries) {
> > +            if (!entries) {
> > +                entries = partialentries;
> > +                nentries = npartialentries;
> > +                tail = partialentries;
> > +            } else {
> > +                tail->next = partialentries;
> > +                nentries += npartialentries;
> > +            }
> > +            while (tail->next) {
> > +                tail = tail->next;
> > +            }
> > +            offset = tail->offset;
> > +        } else {
> > +            break;
> > +        }
> > +    }
> > +
> > +    g_assert_cmpint(
> > +        nentries, ==,
> > +        QTEST_V9FS_SYNTH_READDIR_NFILES + 2 /* "." and ".." */
> > +    );
> > +
> > +    /*
> > +     * Check all file names exist in returned entries, ignore their order
> > +     * though.
> > +     */
> > +    g_assert_cmpint(fs_dirents_contain_name(entries, "."), ==, true);
> > +    g_assert_cmpint(fs_dirents_contain_name(entries, ".."), ==, true);
> > +    for (int i = 0; i < QTEST_V9FS_SYNTH_READDIR_NFILES; ++i) {
> > +        char *name = g_strdup_printf(QTEST_V9FS_SYNTH_READDIR_FILE, i);
> > +        g_assert_cmpint(fs_dirents_contain_name(entries, name), ==,
> > true);
> > +        g_free(name);
> > +    }
> > +
> > +    v9fs_free_dirents(entries);
> > +
> > +    g_free(wnames[0]);
> > +}
> > +
> > 
> >  static void fs_walk_no_slash(void *obj, void *data, QGuestAllocator
> >  *t_alloc) {
> >  
> >      QVirtio9P *v9p = obj;
> > 
> > @@ -793,6 +877,24 @@ static void fs_flush_ignored(void *obj, void *data,
> > QGuestAllocator *t_alloc)> 
> >      g_free(wnames[0]);
> >  
> >  }
> > 
> > +static void fs_readdir_split_128(void *obj, void *data,
> > +                                 QGuestAllocator *t_alloc)
> > +{
> > +    fs_readdir_split(obj, data, t_alloc, 128);
> > +}
> > +
> > +static void fs_readdir_split_256(void *obj, void *data,
> > +                                 QGuestAllocator *t_alloc)
> > +{
> > +    fs_readdir_split(obj, data, t_alloc, 256);
> > +}
> > +
> > +static void fs_readdir_split_512(void *obj, void *data,
> > +                                 QGuestAllocator *t_alloc)
> > +{
> > +    fs_readdir_split(obj, data, t_alloc, 512);
> > +}
> > +
> > 
> >  static void register_virtio_9p_test(void)
> >  {
> >  
> >      qos_add_test("config", "virtio-9p", pci_config, NULL);
> > 
> > @@ -810,6 +912,12 @@ static void register_virtio_9p_test(void)
> > 
> >      qos_add_test("fs/flush/ignored", "virtio-9p", fs_flush_ignored,
> >      
> >                   NULL);
> >      
> >      qos_add_test("fs/readdir/basic", "virtio-9p", fs_readdir, NULL);
> > 
> > +    qos_add_test("fs/readdir/split_512", "virtio-9p",
> > +                 fs_readdir_split_512, NULL);
> > +    qos_add_test("fs/readdir/split_256", "virtio-9p",
> > +                 fs_readdir_split_256, NULL);
> > +    qos_add_test("fs/readdir/split_128", "virtio-9p",
> > +                 fs_readdir_split_128, NULL);
> > 
> >  }
> >  
> >  libqos_init(register_virtio_9p_test);