From: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Hi,
Virtiofs is a fuse-over-virtio filesystem to allow
virtual machines to access a fileystem easily, it's
currently in development, and we'd like to try and
get some of our structures and commands stabilised.
Since it runs over virtio, a spec is currently running through
the virtio standardisation process, and they'd like to
see the additional Fuse commands nailed down. Also we'd
like to stop chasing bit/command number allocation.
The additions included here provide a performance feature
that lets the daemon map files into the hypervisor and thus
guests address space, allowing a DAX like mapping.
Note:
For you following these patches in virtiofs, I've
made three changes:
a) Remove the unused 'fh' field from removemapping
b) Change the 'map_alignment' field to be log2(size) and
use up the current uint16_t padding rather than eating
a fresh uint32_t
c) Moved FUSE_MAP_ALIGNMENT along one bit since
FUSE_EXPLICIT_INVAL_DATA used up bit 25.
References:
virtiofs home page: https://virtio-fs.gitlab.io/
virtio-fs specification patches: https://lists.oasis-open.org/archives/virtio-dev/201907/msg00052.html
Dave
Dr. David Alan Gilbert (3):
fuse: Add 'setupmapping'
fuse: add 'removemapping'
fuse: Add map_alignment for setup/remove mapping
include/uapi/linux/fuse.h | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
--
2.21.0
