search for: fr_sent

...itter can't make progress. Deadlock. Fix this by punting the requests to a list and retry submission later with the help of a worker. Thanks Vivek Vivek Goyal (5): virtiofs: Do not end request in submission context virtiofs: No need to check fpq->connected state virtiofs: Set FR_SENT flag only after request has been sent virtiofs: Count pending forgets as in_flight forgets virtiofs: Retry request submission from worker context fs/fuse/virtio_fs.c | 165 +++++++++++++++++++++++++++++--------------- 1 file changed, 111 insertions(+), 54 deletions(-) -- 2.20.1

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 --git a/fs/fuse/virtio_fs.c b/fs/fu...

...pages; i++) { + thislen = ap->descs[i].length; + if (len < 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 = + contai...

...pages; i++) { + thislen = ap->descs[i].length; + if (len < 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 = + contai...

...irtio_fs_enqueue_req(fsvq, req); > > if (ret < 0) { > > if (ret == -ENOMEM || ret == -ENOSPC) { > > /* Virtqueue 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 */ >...

...; + 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(); > > > + /* TODO check for FR_INTERRUPTED? */ > > > > > > ? > > hmm... we don't support FR_INTERRUPTED. Stefan, do you remember why &...

...islen) { > + 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); > + 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...

...{ > + WARN_ON(req->page_descs[i].offset); > + page = req->pages[i]; > + zero_user_segment(page, len, 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...

...{ > + WARN_ON(req->page_descs[i].offset); > + page = req->pages[i]; > + zero_user_segment(page, len, 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...

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

...ut.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(); > > + /* TODO check for FR_INTERRUPTED? */ > > > ? hmm... we don't support FR_INTERRUPTED. Stefan, do you remember why this TODO is here. If not, I will get rid...