search for: fuse_request_end

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

In error path we are calling fuse_request_end() but we need to clear FR_SENT bit as well as remove request from processing queue. Otherwise fuse_request_end() triggers a warning as well as other issues show up. Signed-off-by: Vivek Goyal <vgoyal at redhat.com> --- fs/fuse/virtio_fs.c | 4 ++++ 1 file changed, 4 insertions(+) diff --gi...

...thislen) { + WARN_ON(ap->descs[i].offset); + page = ap->pages[i]; + zero_user_segment(page, len, thislen); + len = 0; + } else { + len -= thislen; + } + } + } + + spin_lock(&fpq->lock); + clear_bit(FR_SENT, &req->flags); + spin_unlock(&fpq->lock); + + fuse_request_end(fc, req); + spin_lock(&fsvq->lock); + dec_in_flight_req(fsvq); + spin_unlock(&fsvq->lock); +} + +static void virtio_fs_complete_req_work(struct work_struct *work) +{ + struct virtio_fs_req_work *w = + container_of(work, typeof(*w), done_work); + + virtio_fs_request_complete(w->req...

...thislen) { + WARN_ON(ap->descs[i].offset); + page = ap->pages[i]; + zero_user_segment(page, len, thislen); + len = 0; + } else { + len -= thislen; + } + } + } + + spin_lock(&fpq->lock); + clear_bit(FR_SENT, &req->flags); + spin_unlock(&fpq->lock); + + fuse_request_end(fc, req); + spin_lock(&fsvq->lock); + dec_in_flight_req(fsvq); + spin_unlock(&fsvq->lock); +} + +static void virtio_fs_complete_req_work(struct work_struct *work) +{ + struct virtio_fs_req_work *w = + container_of(work, typeof(*w), done_work); + + virtio_fs_request_complete(w->req...

...changed, 4 insertions(+) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index c46dd4d284d6..5df97dfee37d 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -360,6 +360,9 @@ static void virtio_fs_requests_done_work(struct work_struct *work) spin_unlock(&fpq->lock); fuse_request_end(fc, req); + spin_lock(&fsvq->lock); + fsvq->in_flight--; + spin_unlock(&fsvq->lock); } } @@ -769,6 +772,7 @@ static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, goto out; } + fsvq->in_flight++; notify = virtqueue_kick_prepare(vq); spin_unlock(&fs...

...rtqueue full. Retry submission */ > > @@ -965,7 +989,13 @@ __releases(fiq->lock) > > clear_bit(FR_SENT, &req->flags); > > list_del_init(&req->list); > > spin_unlock(&fpq->lock); > > - fuse_request_end(fc, req); > > + > > + /* Can't end request in submission context. Use a worker */ > > + spin_lock(&fsvq->lock); > > + list_add_tail(&req->list, &fsvq->end_reqs); > > + schedule_delayed_wor...

...spin_unlock(&fsvq->lock); > > - return; > > + break; > > } > > > > list_del_init(&req->list); > > spin_unlock(&fsvq->lock); > > fuse_request_end(fc, req); > > } > > + > > + /* Dispatch pending requests */ > > + while (1) { > > + spin_lock(&fsvq->lock); > > + req = list_first_entry_or_null(&fsvq->queued_reqs, > > +...

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 issues. These patches apply on top of following. git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git#virtiofs-v4 I have tested these patches with mount/umount and device removal using qemu monitor. For

...fpq = &fs->vqs[queue_id].fud->pq; > > + spin_lock(&fpq->lock); > > + if (!fpq->connected) { > > + spin_unlock(&fpq->lock); > > + req->out.h.error = -ENODEV; > > + pr_err("virtio-fs: %s disconnected\n", __func__); > > + fuse_request_end(fc, req); > > + return; > > + } > > + list_add_tail(&req->list, fpq->processing); > > + spin_unlock(&fpq->lock); > > + set_bit(FR_SENT, &req->flags); > > + /* matches barrier in request_wait_answer() */ > > + smp_mb__after_atomic();...

...thislen); > + len = 0; > + } else { > + len -= thislen; > + } > + } > + } > + > + spin_lock(&fpq->lock); > + clear_bit(FR_SENT, &req->flags); > + list_del_init(&req->list); > + spin_unlock(&fpq->lock); > + > + fuse_request_end(fc, req); > + } > +} > + > +/* Virtqueue interrupt handler */ > +static void virtio_fs_vq_done(struct virtqueue *vq) > +{ > + struct virtio_fs_vq *fsvq = vq_to_fsvq(vq); > + > + dev_dbg(&vq->vdev->dev, "%s %s\n", __func__, fsvq->name); > + > +...

...thislen); > + len = 0; > + } else { > + len -= thislen; > + } > + } > + } > + > + spin_lock(&fpq->lock); > + clear_bit(FR_SENT, &req->flags); > + list_del_init(&req->list); > + spin_unlock(&fpq->lock); > + > + fuse_request_end(fc, req); > + } > +} > + > +/* Virtqueue interrupt handler */ > +static void virtio_fs_vq_done(struct virtqueue *vq) > +{ > + struct virtio_fs_vq *fsvq = vq_to_fsvq(vq); > + > + dev_dbg(&vq->vdev->dev, "%s %s\n", __func__, fsvq->name); > + > +...

...c_in_flight_req(fsvq); kfree(forget); } spin_unlock(&fsvq->lock); return; } - fsvq->in_flight++; notify = virtqueue_kick_prepare(vq); spin_unlock(&fsvq->lock); @@ -472,7 +467,7 @@ static void virtio_fs_requests_done_work(struct work_struct *work) fuse_request_end(fc, req); spin_lock(&fsvq->lock); - fsvq->in_flight--; + dec_in_flight_req(fsvq); spin_unlock(&fsvq->lock); } } @@ -730,6 +725,7 @@ __releases(fiq->lock) list_add_tail(&forget->list, &fsvq->queued_reqs); schedule_delayed_work(&fsvq->dispat...

...d].fud->pq; > > > + spin_lock(&fpq->lock); > > > + if (!fpq->connected) { > > > + spin_unlock(&fpq->lock); > > > + req->out.h.error = -ENODEV; > > > + pr_err("virtio-fs: %s disconnected\n", __func__); > > > + fuse_request_end(fc, req); > > > + return; > > > + } > > > + list_add_tail(&req->list, fpq->processing); > > > + spin_unlock(&fpq->lock); > > > + set_bit(FR_SENT, &req->flags); > > > + /* matches barrier in request_wait_answer() */ >...

...thislen); > + len = 0; > + } else { > + len -= thislen; > + } > + } > + } > + > + spin_lock(&fpq->lock); > + clear_bit(FR_SENT, &req->flags); > + list_del_init(&req->list); > + spin_unlock(&fpq->lock); > + > + fuse_request_end(fc, req); > + spin_lock(&fsvq->lock); > + fsvq->in_flight--; > + spin_unlock(&fsvq->lock); > + } > +} > + > +/* Virtqueue interrupt handler */ > +static void virtio_fs_vq_done(struct virtqueue *vq) > +{ > + struct virtio_fs_vq *fsvq = vq_to_fsvq(vq)...