On Thu, Sep 30, 2021 at 11:30:36AM -0400, Vivek Goyal wrote: > As of now we don't support fcntl(F_SETLKW) and if we see one, we return > -EOPNOTSUPP. > > Change that by accepting these requests and returning a reply > immediately asking caller to wait. Once lock is available, send a > notification to the waiter indicating lock is available. > > In response to lock request, we are returning error value as "1", which > signals to client to queue the lock request internally and later client > will get a notification which will signal lock is taken (or error). And > then fuse client should wake up the guest process. > > Signed-off-by: Vivek Goyal <[email protected]> > Signed-off-by: Ioannis Angelakopoulos <[email protected]> > --- > tools/virtiofsd/fuse_lowlevel.c | 37 ++++++++++++++++- > tools/virtiofsd/fuse_lowlevel.h | 26 ++++++++++++ > tools/virtiofsd/fuse_virtio.c | 50 ++++++++++++++++++++--- > tools/virtiofsd/passthrough_ll.c | 70 ++++++++++++++++++++++++++++---- > 4 files changed, 167 insertions(+), 16 deletions(-) > > diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c > index e4679c73ab..2e7f4b786d 100644 > --- a/tools/virtiofsd/fuse_lowlevel.c > +++ b/tools/virtiofsd/fuse_lowlevel.c > @@ -179,8 +179,8 @@ int fuse_send_reply_iov_nofree(fuse_req_t req, int error, > struct iovec *iov, > .unique = req->unique, > .error = error, > }; > - > - if (error <= -1000 || error > 0) { > + /* error = 1 has been used to signal client to wait for notificaiton */
s/notificaiton/notification/
> + if (error <= -1000 || error > 1) {
> fuse_log(FUSE_LOG_ERR, "fuse: bad error value: %i\n", error);
> out.error = -ERANGE;
> }
> @@ -290,6 +290,11 @@ int fuse_reply_err(fuse_req_t req, int err)
> return send_reply(req, -err, NULL, 0);
> }
>
> +int fuse_reply_wait(fuse_req_t req)
> +{
> + return send_reply(req, 1, NULL, 0);
> +}
> +
> void fuse_reply_none(fuse_req_t req)
> {
> fuse_free_req(req);
> @@ -2165,6 +2170,34 @@ static void do_destroy(fuse_req_t req, fuse_ino_t
> nodeid,
> send_reply_ok(req, NULL, 0);
> }
>
> +static int send_notify_iov(struct fuse_session *se, int notify_code,
> + struct iovec *iov, int count)
> +{
> + struct fuse_out_header out;
> + if (!se->got_init) {
> + return -ENOTCONN;
> + }
> + out.unique = 0;
> + out.error = notify_code;
Please fully initialize all fuse_out_header fields so it's obvious that
there is no accidental information leak from virtiofsd to the guest:
struct fuse_out_header out = {
.error = notify_code,
};
The host must not expose uninitialized memory to the guest (just like
the kernel vs userspace). fuse_send_msg() initializes out.len later, but
to be on the safe side I think we should be explicit here.
signature.asc
Description: PGP signature
_______________________________________________ Virtio-fs mailing list [email protected] https://listman.redhat.com/mailman/listinfo/virtio-fs
