diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2013-07-29 15:02:00 +0200 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2013-08-13 09:30:49 -0500 |
| commit | 390880f3d38b55e5eca07ad8f8683175cb97f5a8 (patch) | |
| tree | 8454e58a3947aa366375eb3aad9363d4c2695f7c | |
| parent | f3249bf62cc2d72399e8df25e554e5e307d7ea06 (diff) | |
| download | qemu-390880f3d38b55e5eca07ad8f8683175cb97f5a8.tar.gz | |
dataplane: refuse to start if device is already in use
Dataplane must check whether a block device is in use before launching
the dataplane thread. This is necessary since the thread does not
synchronize with the main loop and I/O requests could cause corruption.
One example is when a drive is added and a block job is started before
hotplugging the virtio-blk-pci adapter. In this case we must not use
dataplane mode.
Cc: qemu-stable@nongnu.org
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit b0f2027cde31c645524256763672e09eeb204a9a)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | hw/block/dataplane/virtio-blk.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 03566650c6..a58cc53521 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -418,6 +418,14 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, return false; } + /* If dataplane is (re-)enabled while the guest is running there could be + * block jobs that can conflict. + */ + if (bdrv_in_use(blk->conf.bs)) { + error_report("cannot start dataplane thread while device is in use"); + return false; + } + fd = raw_get_aio_fd(blk->conf.bs); if (fd < 0) { error_report("drive is incompatible with x-data-plane, " |