Kindly ping.
Thanks,
Stefano
On Thu, May 09, 2019 at 04:59:27PM +0200, Stefano Garzarella wrote:
> RBD APIs don't allow us to write more than the size set with
> rbd_create() or rbd_resize().
> In order to support growing images (eg. qcow2), we resize the
> image before write operations that exceed the current size.
>
> Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
> ---
> v3:
> - add 'image_size' field in the BDRVRBDState to keep track of the
> current size of the RBD image [Jason, Kevin]
> ---
> block/rbd.c | 42 +++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 39 insertions(+), 3 deletions(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index 0c549c9935..b0355a2ce0 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -102,6 +102,7 @@ typedef struct BDRVRBDState {
> rbd_image_t image;
> char *image_name;
> char *snap;
> + uint64_t image_size;
> } BDRVRBDState;
>
> static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx,
> @@ -777,6 +778,14 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict
> *options, int flags,
> goto failed_open;
> }
>
> + r = rbd_get_size(s->image, &s->image_size);
> + if (r < 0) {
> + error_setg_errno(errp, -r, "error getting image size from %s",
> + s->image_name);
> + rbd_close(s->image);
> + goto failed_open;
> + }
> +
> /* If we are using an rbd snapshot, we must be r/o, otherwise
> * leave as-is */
> if (s->snap != NULL) {
> @@ -833,6 +842,22 @@ static void qemu_rbd_close(BlockDriverState *bs)
> rados_shutdown(s->cluster);
> }
>
> +/* Resize the RBD image and update the 'image_size' with the current size */
> +static int qemu_rbd_resize(BlockDriverState *bs, uint64_t size)
> +{
> + BDRVRBDState *s = bs->opaque;
> + int r;
> +
> + r = rbd_resize(s->image, size);
> + if (r < 0) {
> + return r;
> + }
> +
> + s->image_size = size;
> +
> + return 0;
> +}
> +
> static const AIOCBInfo rbd_aiocb_info = {
> .aiocb_size = sizeof(RBDAIOCB),
> };
> @@ -934,13 +959,25 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
> }
>
> switch (cmd) {
> - case RBD_AIO_WRITE:
> + case RBD_AIO_WRITE: {
> + /*
> + * RBD APIs don't allow us to write more than actual size, so in
> order
> + * to support growing images, we resize the image before write
> + * operations that exceed the current size.
> + */
> + if (off + size > s->image_size) {
> + r = qemu_rbd_resize(bs, off + size);
> + if (r < 0) {
> + goto failed_completion;
> + }
> + }
> #ifdef LIBRBD_SUPPORTS_IOVEC
> r = rbd_aio_writev(s->image, qiov->iov, qiov->niov, off, c);
> #else
> r = rbd_aio_write(s->image, off, size, rcb->buf, c);
> #endif
> break;
> + }
> case RBD_AIO_READ:
> #ifdef LIBRBD_SUPPORTS_IOVEC
> r = rbd_aio_readv(s->image, qiov->iov, qiov->niov, off, c);
> @@ -1051,7 +1088,6 @@ static int coroutine_fn
> qemu_rbd_co_truncate(BlockDriverState *bs,
> PreallocMode prealloc,
> Error **errp)
> {
> - BDRVRBDState *s = bs->opaque;
> int r;
>
> if (prealloc != PREALLOC_MODE_OFF) {
> @@ -1060,7 +1096,7 @@ static int coroutine_fn
> qemu_rbd_co_truncate(BlockDriverState *bs,
> return -ENOTSUP;
> }
>
> - r = rbd_resize(s->image, offset);
> + r = qemu_rbd_resize(bs, offset);
> if (r < 0) {
> error_setg_errno(errp, -r, "Failed to resize file");
> return r;
> --
> 2.20.1
>
>
--
Stefano Garzarella
Software Engineer @ Red Hat
