@@ -2270,8 +2270,9 @@ static void do_loadvm(Monitor *mon, const QDict *qdict)
vm_stop(0);
- if (load_vmstate(name) >= 0 && saved_vm_running)
+ if (load_vmstate(name) == 0 && saved_vm_running) {
vm_start();
+ }
}
int monitor_get_fd(Monitor *mon, const char *fdname)
@@ -1804,12 +1804,27 @@ void do_savevm(Monitor *mon, const QDict *qdict)
int load_vmstate(const char *name)
{
- BlockDriverState *bs, *bs1;
+ BlockDriverState *bs, *bs_vm_state;
QEMUSnapshotInfo sn;
QEMUFile *f;
int ret;
- /* Verify if there is a device that doesn't support snapshots and is writable */
+ bs_vm_state = bdrv_snapshots();
+ if (!bs_vm_state) {
+ error_report("No block device supports snapshots");
+ return -ENOTSUP;
+ }
+
+ /* Don't even try to load empty VM states */
+ ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
+ if (ret < 0) {
+ return ret;
+ } else if (sn.vm_state_size == 0) {
+ return -EINVAL;
+ }
+
+ /* Verify if there is any device that doesn't support snapshots and is
+ writable and check if the requested snapshot is available too. */
bs = NULL;
while ((bs = bdrv_next(bs))) {
@@ -1822,63 +1837,45 @@ int load_vmstate(const char *name)
bdrv_get_device_name(bs));
return -ENOTSUP;
}
- }
- bs = bdrv_snapshots();
- if (!bs) {
- error_report("No block device supports snapshots");
- return -EINVAL;
+ ret = bdrv_snapshot_find(bs, &sn, name);
+ if (ret < 0) {
+ error_report("Device '%s' does not have the requested snapshot '%s'",
+ bdrv_get_device_name(bs), name);
+ return ret;
+ }
}
/* Flush all IO requests so they don't interfere with the new state. */
qemu_aio_flush();
- bs1 = NULL;
- while ((bs1 = bdrv_next(bs1))) {
- if (bdrv_can_snapshot(bs1)) {
- ret = bdrv_snapshot_goto(bs1, name);
+ bs = NULL;
+ while ((bs = bdrv_next(bs))) {
+ if (bdrv_can_snapshot(bs)) {
+ ret = bdrv_snapshot_goto(bs, name);
if (ret < 0) {
- switch(ret) {
- case -ENOTSUP:
- error_report("%sSnapshots not supported on device '%s'",
- bs != bs1 ? "Warning: " : "",
- bdrv_get_device_name(bs1));
- break;
- case -ENOENT:
- error_report("%sCould not find snapshot '%s' on device '%s'",
- bs != bs1 ? "Warning: " : "",
- name, bdrv_get_device_name(bs1));
- break;
- default:
- error_report("%sError %d while activating snapshot on '%s'",
- bs != bs1 ? "Warning: " : "",
- ret, bdrv_get_device_name(bs1));
- break;
- }
- /* fatal on snapshot block device */
- if (bs == bs1)
- return 0;
+ error_report("Error %d while activating snapshot '%s' on '%s'",
+ ret, name, bdrv_get_device_name(bs));
+ return ret;
}
}
}
- /* Don't even try to load empty VM states */
- ret = bdrv_snapshot_find(bs, &sn, name);
- if ((ret >= 0) && (sn.vm_state_size == 0))
- return -EINVAL;
-
/* restore the VM state */
- f = qemu_fopen_bdrv(bs, 0);
+ f = qemu_fopen_bdrv(bs_vm_state, 0);
if (!f) {
error_report("Could not open VM state file");
return -EINVAL;
}
+
ret = qemu_loadvm_state(f);
+
qemu_fclose(f);
if (ret < 0) {
error_report("Error %d while loading VM state", ret);
return ret;
}
+
return 0;
}
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. Changelog from v1 --------------- - Use -ENOTSUP instead of -EINVAL when no device supports snapshots - Split the verification of the existance of an snapshot on the VM state device and the verification of the size of the saved VM state Signed-off-by: Miguel Di Ciurcio Filho <miguel.filho@gmail.com> --- monitor.c | 3 +- savevm.c | 71 +++++++++++++++++++++++++++++------------------------------- 2 files changed, 36 insertions(+), 38 deletions(-)