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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2013-07-29 15:02:00 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2013-07-29 17:19:15 +0200 |
| commit | b0f2027cde31c645524256763672e09eeb204a9a (patch) | |
| tree | 3a2bcfa400a11a01bfdab4299da63ea88f8deece /hw | |
| parent | 84db52d059f3296abf7783968645c4a96d21b099 (diff) | |
| download | qemu-b0f2027cde31c645524256763672e09eeb204a9a.zip qemu-b0f2027cde31c645524256763672e09eeb204a9a.tar.gz qemu-b0f2027cde31c645524256763672e09eeb204a9a.tar.bz2 | |
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>
Diffstat (limited to 'hw')
| -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 63c3ffa..411becc 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -415,6 +415,14 @@ 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, " |