On Fri, 25 Sep 2009, Valdis.Kletnieks wrote: > On Fri, 25 Sep 2009 19:35:23 BST, "Dr. David Alan Gilbert" said: > > > I know it's not possible without this flag, my interest is whether > > it would be possible WITH this flag to promote an fd opened with the > > O_NODE to a normal fd, guaranteeing that it's still operating on the > > same object. > > Well, maybe the question is if we should treat "promote" differently than > "re-open"? > > (And now I'm wondering what happens if you dup() one of these beasts....) dup() only duplicates _references_ to an open file, it does not create a new file. The same applies to fork(). BTW I just checked, and it is possible to re-open or promote an fd opened with O_NODE like this: char tmp[64]; fd = open(filename, O_NODE | O_NOACCESS); /* ... */ sprintf(tmp, "/proc/self/fd/%i", fd); fd_rw = open(tmp, O_RDWR); Now fd_rw is guaranteed to refer to the same inode as fd. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
