Re: [libvirt] [Qemu-devel] [RFC PATCH 0/4] block: file descriptor passing using -filefd and getfd_file

On 05/22/2012 02:18 AM, Kevin Wolf wrote: >> This patch series adds the -filefd command-line option and the >> getfd_file monitor command. This will enable libvirt to open a >> file and push the corresponding filename and file descriptor to >> QEMU. When QEMU needs to "open" a file, it will first check if the >> file descriptor was passed by either of these methods before >> attempting to actually open the file. > > I thought we decided to avoid making some file names magic, and instead > go for the obvious /dev/fd/42? This doesn't make "some file names magic", it makes "all file names magic". In other words, _every_ call to open() first checks the database for an existing fd for the same file name.