Re: [PATCH 00/30] virtiofs daemon (base)

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Michael S. Tsirkin (mst@redhat.com) wrote:
> On Mon, Oct 21, 2019 at 11:58:02AM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > 
> > Hi,
> >   This is the 1st set for the virtiofsd - a daemon
> > that implements the user space side of virtiofs.
> > 
> >   The kernel and qemu device parts recently went in,
> > so the daemon is the only thing missing to have a working
> > set.
> > 
> >   This set is the absolute minimal base set of patches;
> > it's not yet safe to use (from security or correctness);
> > 
> > I'll follow up with ~3 more series in the next few days
> > with:
> > 
> >     a) Security patches that add sandboxing and checking
> >        compared with normal fuse - that makes it safe.
> >     b) Performance improvements including threading
> >     c) Other fixes, including correctness.
> > 
> > but, this is a good start and gets things rolling.
> > 
> > The set pulls in a big chunk of the upstream libfuse library
> > (unmodified so that it's easy to check it really is upstream),
> > chops all the stuff out we don't need and then adds the
> > new transport we need.
> > 
> > For new files I've formatted the code according to qemu
> > standards; for files that are from upstream libfuse
> > I've kept with their standards for ease of future updating.
> 
> Thinking of future updates, have you given any thought to
> automating them? Something along the lines of
> update-linux-headers maybe?

The problem is we're changing the code in some of them;
libfuse changes slowly enough that rebasing on a new libfuse isn't too
bad; but once committed, just copying new versions in like update-linux-headers
does isn't going to work because we have to merge in our changes.
I expect to have to cherry-pick changes.  Libfuse has had 75 patches in
the last year; so it doesn't worry me too much.

Dave

> 
> > We can't just link with libfuse, since we have to make ABI incompatible
> > changes for the new transport.
> > 
> > Running this daemon is typically done with:
> > 
> >    ./virtiofsd -o vhost_user_socket=/path/socket -o source=/path/to/fs
> > 
> > connected to a qemu that's then started with:
> >    -chardev socket,id=char0,path=/path/socket -device vhost-user-fs-pci,queue-size=1024,chardev=char0,tag=myfs
> > 
> > and then in the guest mount with:
> >    mount -t virtiofs myfs /mnt
> > 
> > Our development branch is: https://gitlab.com/virtio-fs/qemu/tree/virtio-fs-dev
> > 
> > Dave
> > 
> > 
> > Dr. David Alan Gilbert (22):
> >   virtiofsd: Pull in upstream headers
> >   virtiofsd: Pull in kernel's fuse.h
> >   virtiofsd: Add auxiliary .c's
> >   virtiofsd: Add fuse_lowlevel.c
> >   virtiofsd: Add passthrough_ll
> >   virtiofsd: Trim down imported files
> >   virtiofsd: Fix fuse_daemonize ignored return values
> >   virtiofsd: Fix common header and define for QEMU builds
> >   virtiofsd: fuse: Make iov_length usable outside fuse_lowlevel.c
> >   virtiofsd: Add options for virtio
> >   virtiofsd: Open vhost connection instead of mounting
> >   virtiofsd: Start wiring up vhost-user
> >   virtiofsd: Add main virtio loop
> >   virtiofsd: get/set features callbacks
> >   virtiofsd: Start queue threads
> >   virtiofsd: Poll kick_fd for queue
> >   virtiofsd: Start reading commands from queue
> >   virtiofsd: Send replies to messages
> >   virtiofsd: Keep track of replies
> >   virtiofsd: Add Makefile wiring for virtiofsd contrib
> >   virtiofsd: Fast path for virtio read
> >   virtiofs: Add maintainers entry
> > 
> > Stefan Hajnoczi (7):
> >   virtiofsd: remove mountpoint dummy argument
> >   virtiofsd: remove unused notify reply support
> >   virtiofsd: add -o source=PATH to help output
> >   virtiofsd: add --fd=FDNUM fd passing option
> >   virtiofsd: make -f (foreground) the default
> >   virtiofsd: add vhost-user.json file
> >   virtiofsd: add --print-capabilities option
> > 
> > Vivek Goyal (1):
> >   virtiofsd: Make fsync work even if only inode is passed in
> > 
> >  .gitignore                                  |    1 +
> >  MAINTAINERS                                 |    8 +
> >  Makefile                                    |    9 +
> >  Makefile.objs                               |    1 +
> >  contrib/virtiofsd/50-qemu-virtiofsd.json.in |    5 +
> >  contrib/virtiofsd/Makefile.objs             |   10 +
> >  contrib/virtiofsd/buffer.c                  |  318 +++
> >  contrib/virtiofsd/fuse.h                    | 1268 ++++++++++
> >  contrib/virtiofsd/fuse_common.h             |  823 +++++++
> >  contrib/virtiofsd/fuse_i.h                  |  131 ++
> >  contrib/virtiofsd/fuse_kernel.h             |  858 +++++++
> >  contrib/virtiofsd/fuse_log.c                |   40 +
> >  contrib/virtiofsd/fuse_log.h                |   82 +
> >  contrib/virtiofsd/fuse_loop_mt.c            |   54 +
> >  contrib/virtiofsd/fuse_lowlevel.c           | 2302 +++++++++++++++++++
> >  contrib/virtiofsd/fuse_lowlevel.h           | 2024 ++++++++++++++++
> >  contrib/virtiofsd/fuse_misc.h               |   59 +
> >  contrib/virtiofsd/fuse_opt.c                |  422 ++++
> >  contrib/virtiofsd/fuse_opt.h                |  271 +++
> >  contrib/virtiofsd/fuse_signals.c            |   90 +
> >  contrib/virtiofsd/fuse_virtio.c             |  717 ++++++
> >  contrib/virtiofsd/fuse_virtio.h             |   33 +
> >  contrib/virtiofsd/helper.c                  |  300 +++
> >  contrib/virtiofsd/passthrough_helpers.h     |   76 +
> >  contrib/virtiofsd/passthrough_ll.c          | 1341 +++++++++++
> >  docs/interop/vhost-user.json                |    4 +-
> >  26 files changed, 11246 insertions(+), 1 deletion(-)
> >  create mode 100644 contrib/virtiofsd/50-qemu-virtiofsd.json.in
> >  create mode 100644 contrib/virtiofsd/Makefile.objs
> >  create mode 100644 contrib/virtiofsd/buffer.c
> >  create mode 100644 contrib/virtiofsd/fuse.h
> >  create mode 100644 contrib/virtiofsd/fuse_common.h
> >  create mode 100644 contrib/virtiofsd/fuse_i.h
> >  create mode 100644 contrib/virtiofsd/fuse_kernel.h
> >  create mode 100644 contrib/virtiofsd/fuse_log.c
> >  create mode 100644 contrib/virtiofsd/fuse_log.h
> >  create mode 100644 contrib/virtiofsd/fuse_loop_mt.c
> >  create mode 100644 contrib/virtiofsd/fuse_lowlevel.c
> >  create mode 100644 contrib/virtiofsd/fuse_lowlevel.h
> >  create mode 100644 contrib/virtiofsd/fuse_misc.h
> >  create mode 100644 contrib/virtiofsd/fuse_opt.c
> >  create mode 100644 contrib/virtiofsd/fuse_opt.h
> >  create mode 100644 contrib/virtiofsd/fuse_signals.c
> >  create mode 100644 contrib/virtiofsd/fuse_virtio.c
> >  create mode 100644 contrib/virtiofsd/fuse_virtio.h
> >  create mode 100644 contrib/virtiofsd/helper.c
> >  create mode 100644 contrib/virtiofsd/passthrough_helpers.h
> >  create mode 100644 contrib/virtiofsd/passthrough_ll.c
> > 
> > -- 
> > 2.23.0
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK