migration: Clear error at entry of migrate_fd_connect()

For each "migrate" command, remember to clear the s->error before going on.
For one reason, when there's a new error it'll be still remembered; see
migrate_set_error() who only sets the error if error==NULL.  Meanwhile if a
failed migration completes (e.g., postcopy recovered and finished), we
shouldn't dump an error when calling migrate_fd_cleanup() at last.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210708190653.252961-4-peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Peter Xu 2021-07-08 15:06:53 -04:00 committed by Dr. David Alan Gilbert
parent ca30f24d12
commit ca7bd0821b

View File

@ -1855,6 +1855,15 @@ void migrate_set_error(MigrationState *s, const Error *error)
}
}
static void migrate_error_free(MigrationState *s)
{
QEMU_LOCK_GUARD(&s->error_mutex);
if (s->error) {
error_free(s->error);
s->error = NULL;
}
}
void migrate_fd_error(MigrationState *s, const Error *error)
{
trace_migrate_fd_error(error_get_pretty(error));
@ -3970,6 +3979,13 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
int64_t rate_limit;
bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
/*
* If there's a previous error, free it and prepare for another one.
* Meanwhile if migration completes successfully, there won't have an error
* dumped when calling migrate_fd_cleanup().
*/
migrate_error_free(s);
s->expected_downtime = s->parameters.downtime_limit;
if (resume) {
assert(s->cleanup_bh);