diff options
| author | Konstantin Neumoin <kneumoin@virtuozzo.com> | 2016-07-11 15:28:59 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-08-01 21:44:51 +0300 |
| commit | 37cf99e08c6fb4dcea0f9ad2b13b6daa8c76a711 (patch) | |
| tree | 59b824e382709a49d4f85fc16ea213106b088b6a /drivers/virtio | |
| parent | 04b96e5528ca97199b429810fe963185a67dd40e (diff) | |
| download | lwn-37cf99e08c6fb4dcea0f9ad2b13b6daa8c76a711.tar.gz lwn-37cf99e08c6fb4dcea0f9ad2b13b6daa8c76a711.zip | |
balloon: check the number of available pages in leak balloon
The balloon has a special mechanism that is subscribed to the oom
notification which leads to deflation for a fixed number of pages.
The number is always fixed even when the balloon is fully deflated.
But leak_balloon did not expect that the pages to deflate will be more
than taken, and raise a "BUG" in balloon_page_dequeue when page list
will be empty.
So, the simplest solution would be to check that the number of releases
pages is less or equal to the number taken pages.
Cc: stable@vger.kernel.org
Signed-off-by: Konstantin Neumoin <kneumoin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_balloon.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 476c0e3a7150..f6ea8f4ba7cf 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -202,6 +202,8 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num) 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); |