Re: [PATCH v2 4/9] tests/virtio-9p: added readdir test

[Greg Kurz <groug@kaod.org>]

On Wed, 18 Dec 2019 14:30:43 +0100
Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:

> This first readdir test simply checks the amount of directory
> entries returned by 9pfs server, according to the created amount
> of virtual files on 9pfs synth driver side.
> 
> Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> ---

More comments below.

>  tests/virtio-9p-test.c | 124 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 124 insertions(+)
> 
> diff --git a/tests/virtio-9p-test.c b/tests/virtio-9p-test.c
> index 06263edb53..48c0eca292 100644
> --- a/tests/virtio-9p-test.c
> +++ b/tests/virtio-9p-test.c
> @@ -68,6 +68,11 @@ static void v9fs_memread(P9Req *req, void *addr, size_t len)
>      req->r_off += len;
>  }
>  
> +static void v9fs_uint8_read(P9Req *req, uint8_t *val)
> +{
> +    v9fs_memread(req, val, 1);
> +}
> +
>  static void v9fs_uint16_write(P9Req *req, uint16_t val)
>  {
>      uint16_t le_val = cpu_to_le16(val);
> @@ -101,6 +106,12 @@ static void v9fs_uint32_read(P9Req *req, uint32_t *val)
>      le32_to_cpus(val);
>  }
>  
> +static void v9fs_uint64_read(P9Req *req, uint64_t *val)
> +{
> +    v9fs_memread(req, val, 8);
> +    le64_to_cpus(val);
> +}
> +
>  /* len[2] string[len] */
>  static uint16_t v9fs_string_size(const char *string)
>  {
> @@ -191,6 +202,7 @@ static const char *rmessage_name(uint8_t id)
>          id == P9_RLOPEN ? "RLOPEN" :
>          id == P9_RWRITE ? "RWRITE" :
>          id == P9_RFLUSH ? "RFLUSH" :
> +        id == P9_RREADDIR ? "READDIR" :
>          "<unknown>";
>  }
>  
> @@ -348,6 +360,79 @@ static void v9fs_rwalk(P9Req *req, uint16_t *nwqid, v9fs_qid **wqid)
>      v9fs_req_free(req);
>  }
>  
> +/* size[4] Treaddir tag[2] fid[4] offset[8] count[4] */
> +static P9Req *v9fs_treaddir(QVirtio9P *v9p, uint32_t fid, uint64_t offset,
> +                            uint32_t count, uint16_t tag)
> +{
> +    P9Req *req;
> +
> +    req = v9fs_req_init(v9p, 4 + 8 + 4, P9_TREADDIR, tag);
> +    v9fs_uint32_write(req, fid);
> +    v9fs_uint64_write(req, offset);
> +    v9fs_uint32_write(req, count);
> +    v9fs_req_send(req);
> +    return req;
> +}
> +
> +struct v9fs_dirent {
> +    v9fs_qid qid;
> +    uint64_t offset;
> +    uint8_t type;
> +    char *name;
> +    struct v9fs_dirent *next;
> +};
> +
> +/* size[4] Rreaddir tag[2] count[4] data[count] */
> +static void v9fs_rreaddir(P9Req *req, uint32_t *count, uint32_t *nentries,
> +                          struct v9fs_dirent **entries)
> +{
> +    uint32_t sz;

Even if this is a size indeed, the 9p spec uses the wording "count" and
so does the function signature. Please rename this variable to local_count.
Some other functions that return server originated data already use this
naming scheme.

> +    struct v9fs_dirent *e = NULL;
> +    uint16_t slen;
> +    uint32_t n = 0;
> +
> +    v9fs_req_recv(req, P9_RREADDIR);
> +    v9fs_uint32_read(req, &sz);
> +
> +    if (count) {
> +        *count = sz;
> +    }
> +
> +    for (int32_t togo = (int32_t)sz;
> +         togo >= 13 + 8 + 1 + 2;
> +         togo -= 13 + 8 + 1 + 2 + slen, ++n)
> +    {
> +        if (!e) {
> +            e = g_malloc(sizeof(struct v9fs_dirent));
> +            if (entries)

ERROR: braces {} are necessary for all arms of this statement
#98: FILE: tests/virtio-9p-test.c:407:
+            if (entries)
[...]

> +                *entries = e;
> +        } else {
> +            e = e->next = g_malloc(sizeof(struct v9fs_dirent));
> +        }
> +        e->next = NULL;
> +        /* qid[13] offset[8] type[1] name[s] */
> +        v9fs_memread(req, &e->qid, 13);
> +        v9fs_uint64_read(req, &e->offset);
> +        v9fs_uint8_read(req, &e->type);
> +        v9fs_string_read(req, &slen, &e->name);
> +    }
> +
> +    if (nentries) {
> +        *nentries = n;
> +    }
> +}
> +
> +static void v9fs_free_dirents(struct v9fs_dirent *e)
> +{
> +    struct v9fs_dirent *next = NULL;
> +
> +    for (; e; e = next) {
> +        next = e->next;
> +        g_free(e->name);
> +        g_free(e);
> +    }
> +}
> +
>  /* size[4] Tlopen tag[2] fid[4] flags[4] */
>  static P9Req *v9fs_tlopen(QVirtio9P *v9p, uint32_t fid, uint32_t flags,
>                            uint16_t tag)
> @@ -480,6 +565,44 @@ static void fs_walk(void *obj, void *data, QGuestAllocator *t_alloc)
>      g_free(wqid);
>  }
>  
> +static void fs_readdir(void *obj, void *data, QGuestAllocator *t_alloc)
> +{
> +    QVirtio9P *v9p = obj;
> +    alloc = t_alloc;
> +    char *const wnames[] = { g_strdup(QTEST_V9FS_SYNTH_READDIR_DIR) };
> +    uint16_t nqid;
> +    v9fs_qid qid;
> +    uint32_t count, nentries;
> +    struct v9fs_dirent *entries = NULL;
> +    P9Req *req;
> +
> +    fs_attach(v9p, NULL, t_alloc);
> +    req = v9fs_twalk(v9p, 0, 1, 1, wnames, 0);
> +    v9fs_req_wait_for_reply(req, NULL);
> +    v9fs_rwalk(req, &nqid, NULL);
> +    g_assert_cmpint(nqid, ==, 1);
> +
> +    req = v9fs_tlopen(v9p, 1, O_DIRECTORY, 0);
> +    v9fs_req_wait_for_reply(req, NULL);
> +    v9fs_rlopen(req, &qid, NULL);
> +
> +    req = v9fs_treaddir(v9p, 1, 0, P9_MAX_SIZE - P9_IOHDRSZ, 0);
> +    v9fs_req_wait_for_reply(req, NULL);
> +    v9fs_rreaddir(req, &count, &nentries, &entries);
> +
> +    /*
> +     * Assuming msize (P9_MAX_SIZE) is large enough so we can retrieve all
> +     * dir entries with only one readdir request.
> +     */
> +    g_assert_cmpint(
> +        nentries, ==,
> +        QTEST_V9FS_SYNTH_READDIR_NFILES + 2 /* "." and ".." */
> +    );
> +
> +    v9fs_free_dirents(entries);
> +    g_free(wnames[0]);
> +}
> +
>  static void fs_walk_no_slash(void *obj, void *data, QGuestAllocator *t_alloc)
>  {
>      QVirtio9P *v9p = obj;
> @@ -658,6 +781,7 @@ static void register_virtio_9p_test(void)
>                   NULL);
>      qos_add_test("fs/flush/ignored", "virtio-9p", fs_flush_ignored,
>                   NULL);
> +    qos_add_test("fs/readdir/basic", "virtio-9p", fs_readdir, NULL);
>  }
>  
>  libqos_init(register_virtio_9p_test);