qemu /
qemu /
f0aa7a8b2d518c54430e4382309281b93e51981a loadvm: improve tests before bdrv_snapshot_goto()
This patch improves the resilience of the load_vmstate() function, doing
further and better ordered tests.
In load_vmstate(), if there is any error on bdrv_snapshot_goto(), except if the
error is on VM state device, load_vmstate() will return zero and the VM will be
started with major corruption chances.
The current process:
- test if there is any writable device without snapshot support
- if exists return -error
- get the device that saves the VM state, possible return -error but unlikely
because it was tested earlier
- flush I/O
- run bdrv_snapshot_goto() on devices
- if fails, give an warning and goes to the next (not good!)
- if fails on the VM state device, return zero (not good!)
- check if the requested snapshot exists on the device that saves the VM state
and the state is not zero
- if fails return -error
- open the file with the VM state
- if fails return -error
- load the VM state
- if fails return -error
- return zero
New behavior:
- get the device that saves the VM state
- if fails return -error
- check if the requested snapshot exists on the device that saves the VM state
and the state is not zero
- if fails return -error
- test if there is any writable device without snapshot support
- if exists return -error
- test if the devices with snapshot support have the requested snapshot
- if anyone fails, return -error
- flush I/O
- run snapshot_goto() on devices
- if anyone fails, return -error
- open the file with the VM state
- if fails return -error
- load the VM state
- if fails return -error
- return zero
do_loadvm must not call vm_start if any error has occurred in load_vmstate.
Signed-off-by: Miguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2 files changed
