static void leak_balloon(struct virtio_balloon *vb, size_t num) { struct page *page; struct balloon_dev_info *vb_dev_info = vb->vb_dev_info; /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); mutex_lock(&vb->balloon_lock); for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { page = balloon_page_dequeue(vb_dev_info); if (!page) break; set_page_pfns(vb->pfns + vb->num_pfns, page); vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE; } /* * Note that if * virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST); * is true, we *have* to do it in this order */ if (vb->num_pfns != 0) tell_host(vb, vb->deflate_vq); mutex_unlock(&vb->balloon_lock); release_pages_by_pfn(vb->pfns, vb->num_pfns); }
static unsigned leak_balloon(struct virtio_balloon *vb, size_t num) { unsigned num_freed_pages; struct page *page; struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info; LIST_HEAD(pages); /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); mutex_lock(&vb->balloon_lock); /* We can't release more pages than taken */ num = min(num, (size_t)vb->num_pages); for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { page = balloon_page_dequeue(vb_dev_info); if (!page) break; set_page_pfns(vb, vb->pfns + vb->num_pfns, page); list_add(&page->lru, &pages); vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE; } num_freed_pages = vb->num_pfns; /* * Note that if * virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST); * is true, we *have* to do it in this order */ if (vb->num_pfns != 0) tell_host(vb, vb->deflate_vq); release_pages_balloon(vb, &pages); mutex_unlock(&vb->balloon_lock); return num_freed_pages; }