Re: [PATCH v4 7/7] tests/9pfs: check fid being unaffected in fs_walk_2nd_nonexistent

[Greg Kurz <groug@kaod.org>]

On Tue, 15 Mar 2022 11:08:47 +0100
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> Extend previously added test case by checking that fid was unaffected
> by 'Twalk' request (i.e. when 2nd path component of request being
> invalid). Do that by subsequently sending a 'Tgetattr' request with
> the fid previously used for 'Twalk'; that 'Tgetattr' request should
> return an 'Rlerror' response by 9p server with error code ENOENT as
> that fid is basically invalid.
> 
> And as we are at it, also check that the QID returned by 'Twalk' is
> not identical to the root node's QID.
> 
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---

Reviewed-by: Greg Kurz <groug@kaod.org>

>  tests/qtest/virtio-9p-test.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/tests/qtest/virtio-9p-test.c b/tests/qtest/virtio-9p-test.c
> index f6e78d388e..2784ee4b2d 100644
> --- a/tests/qtest/virtio-9p-test.c
> +++ b/tests/qtest/virtio-9p-test.c
> @@ -721,14 +721,19 @@ static void fs_version(void *obj, void *data, QGuestAllocator *t_alloc)
>      do_version(obj);
>  }
>  
> -static void do_attach(QVirtio9P *v9p)
> +static void do_attach_rqid(QVirtio9P *v9p, v9fs_qid *qid)
>  {
>      P9Req *req;
>  
>      do_version(v9p);
>      req = v9fs_tattach(v9p, 0, getuid(), 0);
>      v9fs_req_wait_for_reply(req, NULL);
> -    v9fs_rattach(req, NULL);
> +    v9fs_rattach(req, qid);
> +}
> +
> +static void do_attach(QVirtio9P *v9p)
> +{
> +    do_attach_rqid(v9p, NULL);
>  }
>  
>  static void fs_attach(void *obj, void *data, QGuestAllocator *t_alloc)
> @@ -1101,19 +1106,32 @@ static void fs_walk_2nd_nonexistent(void *obj, void *data,
>  {
>      QVirtio9P *v9p = obj;
>      alloc = t_alloc;
> +    v9fs_qid root_qid;
>      uint16_t nwqid;
> +    uint32_t fid, err;
> +    P9Req *req;
>      g_autofree v9fs_qid *wqid = NULL;
>      g_autofree char *path = g_strdup_printf(
>          QTEST_V9FS_SYNTH_WALK_FILE "/non-existent", 0
>      );
>  
> -    do_attach(v9p);
> -    do_walk_rqids(v9p, path, &nwqid, &wqid);
> +    do_attach_rqid(v9p, &root_qid);
> +    fid = do_walk_rqids(v9p, path, &nwqid, &wqid);
>      /*
>       * The 9p2000 protocol spec says: "nwqid is therefore either nwname or the
>       * index of the first elementwise walk that failed."
>       */
>      assert(nwqid == 1);
> +
> +    /* returned QID wqid[0] is file ID of 1st subdir */
> +    g_assert(wqid && wqid[0] && !is_same_qid(root_qid, wqid[0]));
> +
> +    /* expect fid being unaffected by walk above */
> +    req = v9fs_tgetattr(v9p, fid, P9_GETATTR_BASIC, 0);
> +    v9fs_req_wait_for_reply(req, NULL);
> +    v9fs_rlerror(req, &err);
> +
> +    g_assert_cmpint(err, ==, ENOENT);
>  }
>  
>  static void fs_walk_none(void *obj, void *data, QGuestAllocator *t_alloc)