virtio-blk: handle NULL returns from bdrv_aio_{read, write}

The bdrv_aio_{read,write} routines can return a NULL pointer when the
I/O submission fails.  Currently we ignore this and will wait forever
for an I/O completion and leading to a hang of the guest.

I can easily reproduce this using the native Linux AIO patch, but it's
also possible using normal pthreads-based AIO.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Christoph Hellwig 2009-08-13 16:49:56 +02:00 committed by Anthony Liguori
parent 5c6c3a6c54
commit 87b245db05

View File

@ -254,14 +254,24 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
static void virtio_blk_handle_write(VirtIOBlockReq *req)
{
bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
BlockDriverAIOCB *acb;
acb = bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
req->qiov.size / 512, virtio_blk_rw_complete, req);
if (!acb) {
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
}
}
static void virtio_blk_handle_read(VirtIOBlockReq *req)
{
bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
BlockDriverAIOCB *acb;
acb = bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
req->qiov.size / 512, virtio_blk_rw_complete, req);
if (!acb) {
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
}
}
static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)