On Mon, Dec 12, 2022 at 10:48 PM Stefan Hajnoczi <stefa...@gmail.com> wrote:
>
> On Sun, 11 Dec 2022 at 05:49, Jiachen Zhang
> <zhangjiachen.jay...@bytedance.com> wrote:
> >
> > Add an option '-o num_request_queues' to configure the queue number,
> > currently the total number of vqs should be (1 hiprio queue +
> > num_request_queues).
> >
> > The code is based on Connor's previous version in the virtio-fs
> > mailing-list [1], but change the semantic of the new option from total
> > queue number to request queue number.
> >
> > The corresponding virtio-fs kernel part modification can be found at the
> > mail [2].
> >
> > Link:
> > [1] https://www.mail-archive.com/virtio-fs@redhat.com/msg03333.html
> > [2]
> > https://lore.kernel.org/linux-fsdevel/20221211103857.25805-1-zhangjiachen.jay...@bytedance.com/
> > Suggested-by: Stefan Hajnoczi <stefa...@redhat.com>
> > Cc: Connor Kuehl <cku...@redhat.com>
> > Signed-off-by: Jiachen Zhang <zhangjiachen.jay...@bytedance.com>
> > ---
> > tools/virtiofsd/fuse_lowlevel.c | 4 ++--
> > tools/virtiofsd/fuse_lowlevel.h | 2 +-
> > tools/virtiofsd/fuse_virtio.c | 20 +++-----------------
> > tools/virtiofsd/fuse_virtio.h | 2 +-
> > tools/virtiofsd/helper.c | 4 ++++
> > tools/virtiofsd/passthrough_ll.c | 12 +++++++++++-
> > 6 files changed, 22 insertions(+), 22 deletions(-)
>
> QEMU's C virtiofsd is no longer actively developed. New development
> happens in the Rust https://gitlab.com/virtio-fs/virtiofsd codebase.
> Are you sure you want to continue using C virtiofsd?
>
Thanks for the reminder, I thought the C virtiofsd was the reference
implementation.
> >
> > diff --git a/tools/virtiofsd/fuse_lowlevel.c
> > b/tools/virtiofsd/fuse_lowlevel.c
> > index 2f08471627..528492d2cf 100644
> > --- a/tools/virtiofsd/fuse_lowlevel.c
> > +++ b/tools/virtiofsd/fuse_lowlevel.c
> > @@ -2708,9 +2708,9 @@ out1:
> > return NULL;
> > }
> >
> > -int fuse_session_mount(struct fuse_session *se)
> > +int fuse_session_mount(struct fuse_session *se, unsigned int num_queues)
> > {
> > - return virtio_session_mount(se);
> > + return virtio_session_mount(se, num_queues);
> > }
> >
> > int fuse_session_fd(struct fuse_session *se)
> > diff --git a/tools/virtiofsd/fuse_lowlevel.h
> > b/tools/virtiofsd/fuse_lowlevel.h
> > index b889dae4de..aee02d3e91 100644
> > --- a/tools/virtiofsd/fuse_lowlevel.h
> > +++ b/tools/virtiofsd/fuse_lowlevel.h
> > @@ -1856,7 +1856,7 @@ struct fuse_session *fuse_session_new(struct
> > fuse_args *args,
> > *
> > * @return 0 on success, -1 on failure.
> > **/
> > -int fuse_session_mount(struct fuse_session *se);
> > +int fuse_session_mount(struct fuse_session *se, unsigned int num_queues);
> >
> > /**
> > * Enter a single threaded, blocking event loop.
> > diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
> > index 9368e292e4..a3ebcbea8e 100644
> > --- a/tools/virtiofsd/fuse_virtio.c
> > +++ b/tools/virtiofsd/fuse_virtio.c
> > @@ -762,20 +762,6 @@ static void fv_queue_set_started(VuDev *dev, int qidx,
> > bool started)
> > started);
> > assert(qidx >= 0);
> >
> > - /*
> > - * Ignore additional request queues for now. passthrough_ll.c must be
> > - * audited for thread-safety issues first. It was written with a
> > - * well-behaved client in mind and may not protect against all types of
> > - * races yet.
> > - */
> > - if (qidx > 1) {
> > - fuse_log(FUSE_LOG_ERR,
> > - "%s: multiple request queues not yet implemented, please
> > only "
> > - "configure 1 request queue\n",
> > - __func__);
> > - exit(EXIT_FAILURE);
> > - }
>
> Please include an explanation of why it's safe to drop this now. Have
> the thread-safety issues mentioned in the comment been resolved?
The struct fv_VuDev is protected by vu_dispatch_rwlock. Also the fuse
handlers in passthrough_ll.c are already concurrent with a (size > 1)
g_thread_pool.
>
> > -
> > if (started) {
> > /* Fire up a thread to watch this queue */
> > if (qidx >= vud->nqueues) {
> > @@ -1011,7 +997,7 @@ static int fv_create_listen_socket(struct fuse_session
> > *se)
> > return 0;
> > }
> >
> > -int virtio_session_mount(struct fuse_session *se)
> > +int virtio_session_mount(struct fuse_session *se, unsigned int num_queues)
> > {
> > int ret;
> >
> > @@ -1057,8 +1043,8 @@ int virtio_session_mount(struct fuse_session *se)
> > se->vu_socketfd = data_sock;
> > se->virtio_dev->se = se;
> > pthread_rwlock_init(&se->virtio_dev->vu_dispatch_rwlock, NULL);
> > - if (!vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, NULL,
> > - fv_set_watch, fv_remove_watch, &fv_iface)) {
> > + if (!vu_init(&se->virtio_dev->dev, num_queues, se->vu_socketfd,
> > + fv_panic, NULL, fv_set_watch, fv_remove_watch, &fv_iface))
> > {
> > fuse_log(FUSE_LOG_ERR, "%s: vu_init failed\n", __func__);
> > return -1;
> > }
> > diff --git a/tools/virtiofsd/fuse_virtio.h b/tools/virtiofsd/fuse_virtio.h
> > index 111684032c..a0e78b9b84 100644
> > --- a/tools/virtiofsd/fuse_virtio.h
> > +++ b/tools/virtiofsd/fuse_virtio.h
> > @@ -18,7 +18,7 @@
> >
> > struct fuse_session;
> >
> > -int virtio_session_mount(struct fuse_session *se);
> > +int virtio_session_mount(struct fuse_session *se, unsigned int num_queues);
> > void virtio_session_close(struct fuse_session *se);
> > int virtio_loop(struct fuse_session *se);
> >
> > diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c
> > index f5f66f292c..b5138ce17d 100644
> > --- a/tools/virtiofsd/helper.c
> > +++ b/tools/virtiofsd/helper.c
> > @@ -191,6 +191,10 @@ void fuse_cmdline_help(void)
> > " -o killpriv_v2/no_killpriv_v2\n"
> > " Enable/Disable
> > FUSE_HANDLE_KILLPRIV_V2.\n"
> > " (default: enabled as long as
> > client supports it)\n"
> > + " -o num_request_queues=<num>\n"
> > + " set maximum number of request
> > virtqueues\n"
> > + " supported by virtiofsd"
> > + " default: 1\n"
> > );
> > }
> >
> > diff --git a/tools/virtiofsd/passthrough_ll.c
> > b/tools/virtiofsd/passthrough_ll.c
> > index 20f0f41f99..f9d8075835 100644
> > --- a/tools/virtiofsd/passthrough_ll.c
> > +++ b/tools/virtiofsd/passthrough_ll.c
> > @@ -182,6 +182,7 @@ struct lo_data {
> > /* Keeps track if /proc/<pid>/attr/fscreate should be used or not */
> > bool use_fscreate;
> > int user_security_label;
> > + int num_request_queues;
> > };
> >
> > static const struct fuse_opt lo_opts[] = {
> > @@ -218,6 +219,8 @@ static const struct fuse_opt lo_opts[] = {
> > { "no_posix_acl", offsetof(struct lo_data, user_posix_acl), 0 },
> > { "security_label", offsetof(struct lo_data, user_security_label), 1 },
> > { "no_security_label", offsetof(struct lo_data, user_security_label),
> > 0 },
> > + { "num_request_queues=%d",
> > + offsetof(struct lo_data, num_request_queues), 1 },
> > FUSE_OPT_END
> > };
> > static bool use_syslog = false;
> > @@ -4479,6 +4482,12 @@ int main(int argc, char *argv[])
> >
> > lo.use_statx = true;
> >
> > + if (lo.num_request_queues < 1) {
> > + fuse_log(FUSE_LOG_ERR, "num_request_queues must be at least 1 (got
> > %d)"
> > + "\n", lo.num_request_queues);
> > + exit(1);
> > + }
> > +
> > se = fuse_session_new(&args, &lo_oper, sizeof(lo_oper), &lo);
> > if (se == NULL) {
> > goto err_out1;
> > @@ -4488,7 +4497,8 @@ int main(int argc, char *argv[])
> > goto err_out2;
> > }
> >
> > - if (fuse_session_mount(se) != 0) {
> > + /* There will be 1 hirpio queue plus lo.num_request_queues request
> > queues */
>
> s/hirpio/hiprio/
>
Thanks, will fix it.
Best regards,
Jiachen
> > + if (fuse_session_mount(se, lo.num_request_queues + 1) != 0) {
> > goto err_out3;
> > }
> >
> > --
> > 2.20.1
> >
> >
