On 22/06/2016 12:12, Changlong Xie wrote: > > commit/mirror/stream/backup use block_job_create(..., cb,..) to create > relevant blockjob. When they finished, these jobs will invoke > block_job_completed, then invoke job->cb() unconditionally. So i think > we need this to avoid segment fault. Actually backup has implemented this.
So this suggests that the right place to put the assertion would be block_job_create. But it's even better to add a #define QEMU_NONNULL __attribute__((__nonnull__)) to include/qemu/compiler.h and declare the arguments as non-null. Paolo
