Re: [libvirt] [Qemu-devel] [PATCH v4 7/7] osdep: Enable qemu_open to dup pre-opened fd

Am 25.06.2012 16:34, schrieb Eric Blake: >> Also, I noticed in the fnctl man page that F_SETFL: "On Linux this >> command can change only the O_APPEND, O_ASYNC, O_DIRECT, O_NOATIME, and >> O_NONBLOCK flags." So I'll only set/unset these flags. > > O_NDELAY is the obsolete spelling of O_NONBLOCK; which means the only > other flags in your list not supported by Linux are O_LARGEFILE (which I > said was pointless), O_NOCTTY (which only has an impact at open() and > not later on, so it is not worth worrying about), and O_SYNC (so for > that one, you should error out if not set correctly, as the difference > between O_SYNC on vs. off is significant). As far as I know, newer kernels can change O_SYNC with fcntl, so it's probably worth trying, but you'd have to check if it has really been set. Kevin