Re: [PATCH v3 1/1] block/rbd: Add support for ceph namespaces

[Stefano Garzarella <sgarzare@redhat.com>]

On Fri, Jan 10, 2020 at 12:15:13PM +0100, Florian Florensa wrote:
> Starting from ceph Nautilus, RBD has support for namespaces, allowing
> for finer grain ACLs on images inside a pool, and tenant isolation.
> 
> In the rbd cli tool documentation, the new image-spec and snap-spec are :
>  - [pool-name/[namespace-name/]]image-name
>  - [pool-name/[namespace-name/]]image-name@snap-name
> 
> When using an non namespace's enabled qemu, it complains about not
> finding the image called namespace-name/image-name, thus we only need to
> parse the image once again to find if there is a '/' in its name, and if
> there is, use what is before it as the name of the namespace to later
> pass it to rados_ioctx_set_namespace.
> rados_ioctx_set_namespace if called with en empty string or a null
> pointer as the namespace parameters pretty much does nothing, as it then
> defaults to the default namespace.
> 
> The namespace is extracted inside qemu_rbd_parse_filename, stored in the
> qdict, and used in qemu_rbd_connect to make it work with both qemu-img,
> and qemu itself.
> 
> Signed-off-by: Florian Florensa <fflorensa@online.net>
> ---
>  block/rbd.c          | 44 +++++++++++++++++++++++++++++++-------------
>  qapi/block-core.json |  4 ++++
>  2 files changed, 35 insertions(+), 13 deletions(-)

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Thanks,
Stefano

> 
> diff --git a/block/rbd.c b/block/rbd.c
> index 027cbcc695..84115d34b4 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -104,6 +104,7 @@ typedef struct BDRVRBDState {
>      rbd_image_t image;
>      char *image_name;
>      char *snap;
> +    char *namespace;
>      uint64_t image_size;
>  } BDRVRBDState;
>  
> @@ -152,7 +153,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
>      const char *start;
>      char *p, *buf;
>      QList *keypairs = NULL;
> -    char *found_str;
> +    char *found_str, *image_name;
>  
>      if (!strstart(filename, "rbd:", &start)) {
>          error_setg(errp, "File name must start with 'rbd:'");
> @@ -171,18 +172,24 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
>      qdict_put_str(options, "pool", found_str);
>  
>      if (strchr(p, '@')) {
> -        found_str = qemu_rbd_next_tok(p, '@', &p);
> -        qemu_rbd_unescape(found_str);
> -        qdict_put_str(options, "image", found_str);
> +        image_name = qemu_rbd_next_tok(p, '@', &p);
>  
>          found_str = qemu_rbd_next_tok(p, ':', &p);
>          qemu_rbd_unescape(found_str);
>          qdict_put_str(options, "snapshot", found_str);
>      } else {
> -        found_str = qemu_rbd_next_tok(p, ':', &p);
> +        image_name = qemu_rbd_next_tok(p, ':', &p);
> +    }
> +    /* Check for namespace in the image_name */
> +    if (strchr(image_name, '/')) {
> +        found_str = qemu_rbd_next_tok(image_name, '/', &image_name);
>          qemu_rbd_unescape(found_str);
> -        qdict_put_str(options, "image", found_str);
> +        qdict_put_str(options, "namespace", found_str);
> +    } else {
> +        qdict_put_str(options, "namespace", "");
>      }
> +    qemu_rbd_unescape(image_name);
> +    qdict_put_str(options, "image", image_name);
>      if (!p) {
>          goto done;
>      }
> @@ -343,6 +350,11 @@ static QemuOptsList runtime_opts = {
>              .type = QEMU_OPT_STRING,
>              .help = "Rados pool name",
>          },
> +        {
> +            .name = "namespace",
> +            .type = QEMU_OPT_STRING,
> +            .help = "Rados namespace name in the pool",
> +        },
>          {
>              .name = "image",
>              .type = QEMU_OPT_STRING,
> @@ -467,13 +479,14 @@ static int coroutine_fn qemu_rbd_co_create_opts(const char *filename,
>       * schema, but when they come from -drive, they're all QString.
>       */
>      loc = rbd_opts->location;
> -    loc->pool     = g_strdup(qdict_get_try_str(options, "pool"));
> -    loc->conf     = g_strdup(qdict_get_try_str(options, "conf"));
> -    loc->has_conf = !!loc->conf;
> -    loc->user     = g_strdup(qdict_get_try_str(options, "user"));
> -    loc->has_user = !!loc->user;
> -    loc->image    = g_strdup(qdict_get_try_str(options, "image"));
> -    keypairs      = qdict_get_try_str(options, "=keyvalue-pairs");
> +    loc->pool        = g_strdup(qdict_get_try_str(options, "pool"));
> +    loc->conf        = g_strdup(qdict_get_try_str(options, "conf"));
> +    loc->has_conf    = !!loc->conf;
> +    loc->user        = g_strdup(qdict_get_try_str(options, "user"));
> +    loc->has_user    = !!loc->user;
> +    loc->q_namespace = g_strdup(qdict_get_try_str(options, "namespace"));
> +    loc->image       = g_strdup(qdict_get_try_str(options, "image"));
> +    keypairs         = qdict_get_try_str(options, "=keyvalue-pairs");
>  
>      ret = qemu_rbd_do_create(create_options, keypairs, password_secret, errp);
>      if (ret < 0) {
> @@ -648,6 +661,11 @@ static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx,
>          error_setg_errno(errp, -r, "error opening pool %s", opts->pool);
>          goto failed_shutdown;
>      }
> +    /*
> +     * Set the namespace after opening the io context on the pool,
> +     * if nspace == NULL or if nspace == "", it is just as we did nothing
> +     */
> +    rados_ioctx_set_namespace(*io_ctx, opts->q_namespace);
>  
>      return 0;
>  
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index fcb52ec24f..c6f187ec9b 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -3661,6 +3661,9 @@
>  #
>  # @pool:               Ceph pool name.
>  #
> +# @namespace:          Rados namespace name in the Ceph pool.
> +#                      (Since 5.0)
> +#
>  # @image:              Image name in the Ceph pool.
>  #
>  # @conf:               path to Ceph configuration file.  Values
> @@ -3687,6 +3690,7 @@
>  ##
>  { 'struct': 'BlockdevOptionsRbd',
>    'data': { 'pool': 'str',
> +            '*namespace': 'str',
>              'image': 'str',
>              '*conf': 'str',
>              '*snapshot': 'str',
> -- 
> 2.24.1
>