On Tue, Feb 07, 2017 at 08:36:13PM -0800, Darrick J. Wong wrote: > As one of 'those people', I think I'm well qualified to say that a fake > xattr having side effects that doesn't behave in quite the same ways as > regular xattrs is setting up other programs (the ones that listxattr all > the attrs and getxattrs them) for all kinds of weird yuckiness. And by > 'weird yuckiness' I mean "this one magic xattr returned EOPNOTSUPP and > the whole backup program exploded". > > Now granted you can argue that we're just shifting that into an ioctl, > but ioctls are already weird and yucky. :) If we were going to do anything at all, it would be to move it to a syscall. But given that it took ***years*** for the glibc developers to get around to adding getrandom(2) to glibc, we'd be stuck using the syscall(3) interface and having to deal with different syscall numbers for different architectures (in case we're compiling on a system which hadn't update the kernel headers in /usr/include), and so at least in the short term it would actually be worse than using ioctl's. For similar reasons I don't think there's going to be that much interest in adding a syscall to replace XFS_IOC_GOINGDOWN. We'll probably go with FS_IOC_GOINGDOWN, just as we have with FS_IOC_SETFLAGS, etc. Speaking of XFS_IOC_GOINGDOWN, I'm sure the name was coined many, many years agoo, back when concerns such as "avoiding a hostile working environment" were much of an issue. Even so, I note that *someone* decided that the name that should be exposed to customer (in the xfs_io man page), was "shutdown", and not "goingdown". So is there any objection if we use the name FS_IOC_SHUTDOWN moving forward? Some might accuse us of being overly concerned about political correctness, but I have to admit I did have a slight twinge when I checked in the ext4 shutdown changes into our internal kernel. I was worried that there might be some folks who might have found the name at least a tiny bit offensive. (Not that anyone complained, but I'd much rather be conservative in what we send, and liberal in what we accept.) - Ted
