On Tue, Jan 07, 2014 at 07:49:35AM -0800, Christoph Hellwig wrote: > On Tue, Jan 07, 2014 at 01:48:31PM +0100, Jan Kara wrote: > > I have to say I'm not thrilled by the idea of juggling strings in > > userspace and in kernel to set a flag for an inode... > > Nevermind the massive amounts of code that sit in the filesystem. The reason for this patch was to address what Dave Chinner has called "a shitty interface"[1]. Using bitfields that need to be coordinated across file systems, when sometimes a bit assignment is validly a fs specific thing, and then later becomes something that gets shared across file systems. [1] http://thread.gmane.org/gmane.linux.file-systems/80164/focus=80396 If we don't go about it this way, there are alternatives: we could create new ioctls (or a new syscall) as we start running out of bits used by FS_IOC_[GS]ETFLAGS. We can create new ioctls for bits which are intended for fs-specific flags, which then later get promoted to the new syscall when some functionality starts to get shared accross other file systems (probably with a different bit assignment). This is certainly less code, but it does mean more complexity outside of the code when we try to coordinate new functionality across file systems. Personally, I don't mind dealing with codepoint assignments, but my impression is that this is a minority viewpoint. Al and Linus have historically hated bitfields, and Al in the past has spoken favorably of Plan 9's approach of using strings for the system interface. So while I have a preference towards using bitfields, as opposed to using the xattr approach, what I'd really like is that we make a decision, one way or another, about what's the best way to move forward. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
