Re: [libvirt] [Qemu-devel] [PATCH v2 2/3] monitor: Enable adding an inherited fd to an fd set

On 10/11/2012 07:25 AM, Kevin Wolf wrote: > Am 10.10.2012 16:20, schrieb Corey Bryant: >> qmp_add_fd() gets an fd that was received over a socket with >> SCM_RIGHTS and adds it to an fd set. This patch adds support >> that will enable adding an fd that was inherited on the >> command line to an fd set. >> >> This patch also prevents removal of an fd from an fd set during >> initialization. This allows the fd to remain in the fd set after >> probing of the image file. > > "This patch also..." usually means that it should be split in two > patches. Though in this case I'd vote for immediately dropping the > second patch again: This makes the probing work with file descriptors > using a hack for a certain situation (namely qemu startup) and leaves > other cases (like hotplug) broken. I don't think hotplug is broken. In that case the fd will only be removed from the fd set if the following is true: (mon_fdset_fd->removed || (QLIST_EMPTY(&mon_fdset->dup_fds) && mon_refcount == 0)) We can ignore the removed part for now. What's important here is that if there are no dup_fd references and there is at least one monitor connected, an fd will *not* be removed.