[PULL,7/8] migration: Fail migration on bdrv_flush_all() error

Submitted by Kevin Wolf on July 15, 2013, 11:16 a.m.

Details

Message ID 1373887000-4488-8-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf July 15, 2013, 11:16 a.m.
If bdrv_flush_all() returns an error, there is an inconsistency in the
view of an image file between the source and the destination host.
Completing the migration would lead to corruption. Better abort
migration in this case.

To reproduce this case, try the following (ensures that there is
something to flush, and then fails that flush):

$ qemu-img create -f qcow2 test.qcow2 1G
$ cat blkdebug.cfg
[inject-error]
event = "flush_to_os"
errno = "5"
$ qemu-system-x86_64 -hda blkdebug:blkdebug.cfg:test.qcow2 -monitor stdio
(qemu) qemu-io ide0-hd0 "write 0 4k"
(qemu) migrate ...

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 migration.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

Patch hide | download patch | download mbox

diff --git a/migration.c b/migration.c
index 635a7e7..0681d8e 100644
--- a/migration.c
+++ b/migration.c
@@ -527,15 +527,26 @@  static void *migration_thread(void *opaque)
             if (pending_size && pending_size >= max_size) {
                 qemu_savevm_state_iterate(s->file);
             } else {
+                int ret;
+
                 DPRINTF("done iterating\n");
                 qemu_mutex_lock_iothread();
                 start_time = qemu_get_clock_ms(rt_clock);
                 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
                 old_vm_running = runstate_is_running();
-                vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
-                qemu_file_set_rate_limit(s->file, INT_MAX);
-                qemu_savevm_state_complete(s->file);
+
+                ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+                if (ret >= 0) {
+                    qemu_file_set_rate_limit(s->file, INT_MAX);
+                    qemu_savevm_state_complete(s->file);
+                }
                 qemu_mutex_unlock_iothread();
+
+                if (ret < 0) {
+                    migrate_finish_set_state(s, MIG_STATE_ERROR);
+                    break;
+                }
+
                 if (!qemu_file_get_error(s->file)) {
                     migrate_finish_set_state(s, MIG_STATE_COMPLETED);
                     break;