> On Sep 7, 2019, at 9:58 AM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > >> On Sat, Sep 7, 2019 at 5:40 AM Jeff Layton <jlayton@xxxxxxxxxx> wrote: >> >> After thinking about this a bit, I wonder if we might be better served >> with a new set of OA2_* flags instead of repurposing the O_* flags? > > I'd hate to have yet _another_ set of translation functions, and > another chance of people just getting it wrong either in user space or > the kernel. > > So no. Let's not make another set of flags that has no sane way to > have type-safety to avoid more confusion. > > The new flags that _only_ work with openat2() might be named with a > prefix/suffix to mark that, but I'm not sure it's a huge deal. > > I agree with the philosophy, but I think it doesn’t apply in this case. Here are the flags: O_RDONLY, O_WRONLY, O_RDWR: not even a proper bitmask. The kernel already has the FMODE_ bits to make this make sense. How about we make the openat2 permission bits consistent with the internal representation and let the O_ permission bits remain as an awful translation. The kernel already translates like this, and it already sucks. O_CREAT, O_TMPFILE, O_NOCTTY, O_TRUNC: not modes on the fd at all. These affect the meaning of open(). Heck, for openat2, NOCTTY should be this default. O_EXCL: hopelessly overloaded. O_APPEND, O_DIRECT, O_SYNC, O_DSYNC, O_LARGEFILE, O_NOATIME, O_PATH, O_NONBLOCK: genuine mode bits O_CLOEXEC: special because it affects the fd, not the struct file. Linus, you rejected resolveat() because you wanted a *nice* API that people would use and that might even be adopted by other OSes. Let’s please not make openat2() be a giant pile of crap in the name of consistency with open(). open(), frankly, is horrible.
