similar to: virtq questions

* Miklos Szeredi (miklos at szeredi.hu) wrote: > Looking at the ugly retry logic in virtiofs and have some questions. > First one is, where do these features come from: > > VIRTIO_F_RING_PACKED > VIRTIO_RING_F_INDIRECT_DESC > > I see that in virtiofs "packed" is off and "indirect" is on. Is this > guaranteed? I think the xdindirect is coming from

On Thu, Sep 12, 2019 at 04:19:31PM +0200, Miklos Szeredi wrote: > From: Stefan Hajnoczi <stefanha at redhat.com> > > Michael, > > Here's a v6 of the virtiofs code (fuse.git#virtiofs-v6). I think we've > addressed all your comments. > > Would you mind giving it another look, and if you're satisfied acking this > patch? > > Thanks, > Miklos

On Tue, Sep 03, 2019 at 01:42:02PM +0200, Miklos Szeredi wrote: > From: Stefan Hajnoczi <stefanha at redhat.com> > > Add a basic file system module for virtio-fs. This does not yet contain > shared data support between host and guest or metadata coherency speedups. > However it is already significantly faster than virtio-9p. > > Design Overview > ===============

On Tue, Sep 03, 2019 at 01:42:02PM +0200, Miklos Szeredi wrote: > From: Stefan Hajnoczi <stefanha at redhat.com> > > Add a basic file system module for virtio-fs. This does not yet contain > shared data support between host and guest or metadata coherency speedups. > However it is already significantly faster than virtio-9p. > > Design Overview > ===============

On Wed, Oct 02, 2019 at 09:40:11AM +0200, Miklos Szeredi wrote: > Looking at the ugly retry logic in virtiofs and have some questions. Hi Miklos, What are you thinking w.r.t cleanup of retry logic. As of now we put requests in a list and retry later with the help of a worker. Other option will probably be block the submitter if queue is full. Make it sleep, wake up after a while and retry

From: Vivek Goyal <vgoyal at redhat.com> [ Upstream commit bb737bbe48bea9854455cb61ea1dc06e92ce586c ] In virtiofs (unlike in regular fuse) processing of async replies is serialized. This can result in a deadlock in rare corner cases when there's a circular dependency between the completion of two or more async replies. Such a deadlock can be reproduced with xfstests:generic/503 if

From: Vivek Goyal <vgoyal at redhat.com> [ Upstream commit bb737bbe48bea9854455cb61ea1dc06e92ce586c ] In virtiofs (unlike in regular fuse) processing of async replies is serialized. This can result in a deadlock in rare corner cases when there's a circular dependency between the completion of two or more async replies. Such a deadlock can be reproduced with xfstests:generic/503 if

On Tue, Sep 03, 2019 at 09:55:49AM -0400, Michael S. Tsirkin wrote: [..] > What's with all of the TODOs? Some of these are really scary, > looks like they need to be figured out before this is merged. Hi Michael, One of the issue I noticed is races w.r.t device removal and super block initialization. I am about to post a set of patches which take care of these races and also get rid of

On Mon, Oct 21, 2019 at 10:03:39AM +0200, Miklos Szeredi wrote: [..] > > static void virtio_fs_hiprio_dispatch_work(struct work_struct *work) > > @@ -502,6 +522,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev, > > names[VQ_HIPRIO] = fs->vqs[VQ_HIPRIO].name; > > INIT_WORK(&fs->vqs[VQ_HIPRIO].done_work, virtio_fs_hiprio_done_work);

On Mon, Oct 21, 2019 at 10:15:18AM +0200, Miklos Szeredi wrote: [..] > > @@ -268,13 +272,43 @@ static void virtio_fs_request_dispatch_work(struct work_struct *work) > > list); > > if (!req) { > > spin_unlock(&fsvq->lock); > > - return; > > +

Pass fsvq instead of vq as parameter to virtio_fs_enqueue_req(). We will retrieve vq from fsvq under spin lock. Later in the patch series we will retrieve vq only if fsvq is still connected other vq might have been cleaned up by device ->remove code and we will return error. Signed-off-by: Vivek Goyal <vgoyal at redhat.com> --- fs/fuse/virtio_fs.c | 9 +++++---- 1 file changed, 5

On Sun, Sep 08, 2019 at 07:53:55PM +0800, piaojun wrote: > > > On 2019/9/6 19:52, Miklos Szeredi wrote: > > On Fri, Sep 6, 2019 at 12:36 PM Stefan Hajnoczi <stefanha at redhat.com> wrote: > >> > >> On Fri, Sep 06, 2019 at 10:15:14AM +0200, Miklos Szeredi wrote: > >>> On Thu, Sep 5, 2019 at 9:49 PM Vivek Goyal <vgoyal at redhat.com> wrote:

On Fri, Sep 06, 2019 at 01:52:41PM +0200, Miklos Szeredi wrote: > On Fri, Sep 6, 2019 at 12:36 PM Stefan Hajnoczi <stefanha at redhat.com> wrote: > > > > On Fri, Sep 06, 2019 at 10:15:14AM +0200, Miklos Szeredi wrote: > > > On Thu, Sep 5, 2019 at 9:49 PM Vivek Goyal <vgoyal at redhat.com> wrote: > > > > > > > > Hi, > > > >

On Fri, Sep 06, 2019 at 01:52:41PM +0200, Miklos Szeredi wrote: > On Fri, Sep 6, 2019 at 12:36 PM Stefan Hajnoczi <stefanha at redhat.com> wrote: > > > > On Fri, Sep 06, 2019 at 10:15:14AM +0200, Miklos Szeredi wrote: > > > On Thu, Sep 5, 2019 at 9:49 PM Vivek Goyal <vgoyal at redhat.com> wrote: > > > > > > > > Hi, > > > >

On Tue, Sep 10, 2019 at 05:12:02PM +0200, Miklos Szeredi wrote: > Git tree for this version is available here: > > git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git#virtiofs-v5 > > Only post patches that actually add virtiofs (virtiofs-v5-base..virtiofs-v5). > > I've folded the series from Vivek and fixed a couple of TODO comments > myself. AFAICS two

On Tue, Sep 03, 2019 at 10:05:02AM +0200, Miklos Szeredi wrote: > [Cc: virtualization at lists.linux-foundation.org, "Michael S. Tsirkin" > <mst at redhat.com>, Jason Wang <jasowang at redhat.com>] > > It'd be nice to have an ACK for this from the virtio maintainers. > > Thanks, > Miklos Can the patches themselves be posted to the relevant list(s)

On Tue, Sep 03, 2019 at 10:05:02AM +0200, Miklos Szeredi wrote: > [Cc: virtualization at lists.linux-foundation.org, "Michael S. Tsirkin" > <mst at redhat.com>, Jason Wang <jasowang at redhat.com>] > > It'd be nice to have an ACK for this from the virtio maintainers. > > Thanks, > Miklos Can the patches themselves be posted to the relevant list(s)

On Tue, Sep 10, 2019 at 05:12:02PM +0200, Miklos Szeredi wrote: > Git tree for this version is available here: > > git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git#virtiofs-v5 > > Only post patches that actually add virtiofs (virtiofs-v5-base..virtiofs-v5). > > I've folded the series from Vivek and fixed a couple of TODO comments > myself. AFAICS two

Hi, We have couple of places which can result in deadlock. This patch series fixes these. We can be called with fc->bg_lock (for background requests) while submitting a request. This leads to two constraints. - We can't end requests in submitter's context and call fuse_end_request() as it tries to take fc->bg_lock as well. So queue these requests on a list and use a worker to

On Fri, Sep 06, 2019 at 10:15:14AM +0200, Miklos Szeredi wrote: > On Thu, Sep 5, 2019 at 9:49 PM Vivek Goyal <vgoyal at redhat.com> wrote: > > > > Hi, > > > > Michael Tsirkin pointed out issues w.r.t various locking related TODO > > items and races w.r.t device removal. > > > > In this first round of cleanups, I have taken care of most pressing