On Fri, 07/06 17:09, Eric Blake wrote: > On 07/05/2018 02:37 AM, Fam Zheng wrote: > > If we are growing the image and potentially using preallocation for the > > new area, we need to make sure that no write requests are made to the > > "preallocated" area which [@old_size, @offset), not [@offset, offset * 2 > > s/which/which is/ > > > - @old_size). > > > > Signed-off-by: Fam Zheng <f...@redhat.com> > > --- > > block/io.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > Reviewed-by: Eric Blake <ebl...@redhat.com> > > > > > diff --git a/block/io.c b/block/io.c > > index d07849fa96..ed18eb0ca3 100644 > > --- a/block/io.c > > +++ b/block/io.c > > @@ -3070,7 +3070,8 @@ int coroutine_fn bdrv_co_truncate(BdrvChild *child, > > int64_t offset, > > } > > bdrv_inc_in_flight(bs); > > - tracked_request_begin(&req, bs, offset, new_bytes, > > BDRV_TRACKED_TRUNCATE); > > + tracked_request_begin(&req, bs, offset - new_bytes, new_bytes, > > + BDRV_TRACKED_TRUNCATE); > > Is it any more legible to do s/offset - new_bytes/old_size/, since those are > equivalent?
No they are not. offset - new_bytes is either old_size (if expanding), or smaller than old_size (if shrinking). Fam > > > /* If we are growing the image and potentially using preallocation > > for the > > * new area, we need to make sure that no write requests are made to > > it > > > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org
