Re: [RFC PATCH 01/10] vfio: Create vfio_fs_type with inode per device

From: Jason Gunthorpe
Date: Fri Feb 26 2021 - 08:16:50 EST


On Fri, Feb 26, 2021 at 05:38:04AM +0000, Christoph Hellwig wrote:
> On Mon, Feb 22, 2021 at 09:50:35AM -0700, Alex Williamson wrote:
> > By linking all the device fds we provide to userspace to an
> > address space through a new pseudo fs, we can use tools like
> > unmap_mapping_range() to zap all vmas associated with a device.
> >
> > Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> > Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
>
> Adding Al:
>
> I hate how we're are growing these tiny file systems just to allocate an
> anonymous inode all over. Shouldn't we allow to enhance fs/anon_inodes.c
> to add a new API to allocate a new specific inode from anon_inodefs
> instead?

+1 when I was researching this I also felt this was alot of
boilerplate to just get an inode. With vfio and rdma getting this it
is at least 5 places now.

Jason