[PATCH 09/11] vfs, fscache: Add an IS_KERNEL_FILE() macro for the S_KERNEL_FILE flag

[Christoph Hellwig]

On Tue, Jan 18, 2022 at 05:40:14PM +0000, David Howells wrote:
> Christoph Hellwig <hch at infradead.org> wrote:
> 
> > On Tue, Jan 18, 2022 at 01:54:54PM +0000, David Howells wrote:
> > > Add an IS_KERNEL_FILE() macro to test the S_KERNEL_FILE inode flag as is
> > > common practice for the other inode flags[1].
> > 
> > Please fix the flag to have a sensible name first, as the naming of the
> > flag and this new helper is utterly wrong as we already discussed.
> 
> And I suggested a new name, which you didn't comment on.

Again, look at the semantics of the flag:  The only thing it does in the
VFS is to prevent a rmdir.  So you might want to name it after that.

Or in fact drop the flag entirely.  We don't have that kind of
protection for other in-kernel file use or important userspace daemons
either.  I can't see why cachefiles is the magic snowflake here that
suddenly needs semantics no one else has.