It looks like this has hit a 30 day expiration without any reviews or being merged; do we still want this? If so, can you please resend?
On 5/10/19 11:33 AM, Stefano Garzarella wrote: > This patch allows 'qemu-img info' to show the 'disk size' for > the RBD images that have the fast-diff feature enabled. > > If this feature is enabled, we use the rbd_diff_iterate2() API > to calculate the allocated size for the image. > > Signed-off-by: Stefano Garzarella <sgarz...@redhat.com> > --- > v2: > - calculate the actual usage only if the fast-diff feature is > enabled [Jason] > --- > block/rbd.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 54 insertions(+) > > diff --git a/block/rbd.c b/block/rbd.c > index 0c549c9935..f1bc76ab80 100644 > --- a/block/rbd.c > +++ b/block/rbd.c > @@ -1046,6 +1046,59 @@ static int64_t qemu_rbd_getlength(BlockDriverState *bs) > return info.size; > } > > +static int rbd_allocated_size_cb(uint64_t offset, size_t len, int exists, > + void *arg) > +{ > + int64_t *alloc_size = (int64_t *) arg; > + > + if (exists) { > + (*alloc_size) += len; > + } > + > + return 0; > +} > + > +static int64_t qemu_rbd_get_allocated_file_size(BlockDriverState *bs) > +{ > + BDRVRBDState *s = bs->opaque; > + uint64_t flags, features; > + int64_t alloc_size = 0; > + int r; > + > + r = rbd_get_flags(s->image, &flags); > + if (r < 0) { > + return r; > + } > + Do you know where rbd_get_flags is documented? I can't seem to quickly find a reference that tells me what to expect from calling it. It returns an int, I guess an error code, but how can I confirm this? *clones the ceph repository* src/librbd/internal.cc get_flags convinces me it probably works like I think, but is there not a reference here? > + r = rbd_get_features(s->image, &features); > + if (r < 0) { > + return r; > + } > + > + /* > + * We use rbd_diff_iterate2() only if the RBD image have fast-diff > + * feature enabled. If it is disabled, rbd_diff_iterate2() could be > + * very slow on a big image. > + */ > + if (!(features & RBD_FEATURE_FAST_DIFF) || > + (flags & RBD_FLAG_FAST_DIFF_INVALID)) { > + return -1; > + } > + (Is there a reference for the list of flags to make sure there aren't other cases we might want to skip this?) It looks reasonable at a glance, but maybe let's return -ENOTSUP instead of -1, based on the idea that bdrv_get_allocated_file_size returns -ENOMEDIUM in a prominent error case -- let's match that error convention. (Well, I wonder what the librbd calls are returning and if THOSE mean anything.) > + /* > + * rbd_diff_iterate2(), if the source snapshot name is NULL, invokes > + * the callback on all allocated regions of the image. > + */ > + r = rbd_diff_iterate2(s->image, NULL, 0, > + bs->total_sectors * BDRV_SECTOR_SIZE, 0, 1, > + &rbd_allocated_size_cb, &alloc_size); > + if (r < 0) { > + return r; > + } > + I guess I'll take your word for it. ¯\_(ツ)_/¯ > + return alloc_size; > +} > + > static int coroutine_fn qemu_rbd_co_truncate(BlockDriverState *bs, > int64_t offset, > PreallocMode prealloc, > @@ -1254,6 +1307,7 @@ static BlockDriver bdrv_rbd = { > .bdrv_get_info = qemu_rbd_getinfo, > .create_opts = &qemu_rbd_create_opts, > .bdrv_getlength = qemu_rbd_getlength, > + .bdrv_get_allocated_file_size = qemu_rbd_get_allocated_file_size, > .bdrv_co_truncate = qemu_rbd_co_truncate, > .protocol_name = "rbd", > >