Re: [Libguestfs] [PATCH libnbd 2/2] examples: copy-libev.c: Fix error handling

On Thu, Jan 27, 2022 at 01:49:31AM +0200, Nir Soffer wrote: > This example failed to check the *error parameter to the completion and > extent callbacks. > > - If the source NBD server failed a read, we wrote stale data from the > request buffer to the destination image, corrupting the > image. > > - If the destination NBD server failed a write or zero command, we > ignored the error, leaving previous content on the destination image, > corrupting the image. > > - Error in the extents callbacks were ignored. I'm not sure if this was > a real problem, but it is a very bad example. > > In all cases, the copy would end with zero exit code creating a > corrupted image. Oh well. This silent data corruption affects more than copy-libev.c;