On Mon, Jun 4, 2018 at 7:35 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > On Mon, Jun 04, 2018 at 10:16:30AM -0700, Matthew Wilcox wrote: >> On Sun, Jun 03, 2018 at 01:55:37AM +0100, Al Viro wrote: >> > +SYSCALL_DEFINE3(open_tree, int, dfd, const char *, filename, unsigned, flags) >> > +{ >> > + struct file *file; >> > + struct path path; >> > + int lookup_flags = LOOKUP_AUTOMOUNT | LOOKUP_FOLLOW; >> > + bool detached = flags & OPEN_TREE_CLONE; >> > + int error; >> > + int fd; >> > + >> > + BUILD_BUG_ON(OPEN_TREE_CLOEXEC != O_CLOEXEC); >> >> Why do we need OPEN_TREE_CLOEXEC? Wouldn't we be better off just making >> the fd returned by open_tree implicitly close-on-exec? I can think of >> no good reason for these file descriptors to be inherited across exec() > > How are they different from any file descriptor? It's not as if it was > something usable only for mounting stuff - again, you can use them > with any ...at() syscalls. Defaulting to close on exec helps keep out clutter from the API. Is there a disadvantage to needing an explicit fcntl(F_SETFD) call to disable close on exec? Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html