Am 11.10.2012 17:04, schrieb Corey Bryant:
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.
Ah yes, that's the part I missed. Then your approach of special-casing the command line is probably okay, though I'd still want to change the probing mechanism to avoid the reopen. Seems I need to find a better excuse to make someone do it. Meh. ;-) Kevin