Hi Jun, On Wed, Jul 31, 2019 at 08:05:03PM +0800, piaojun wrote: > Hi liubo, > > This change has already committed in rhvgoyal's branch: > > https://github.com/rhvgoyal/linux/tree/virtio-fs-dev-5.1 >
Thanks for the link, the patch here does one more thing beyond Vivek's current code, i.e. the lock protection around req is also removed as it's not necessary. thanks, -liubo > Thanks, > Jun > > On 2019/7/30 13:51, Liu Bo wrote: > > Right now within virtio_fs_requests_done_work(), virtqueue is protected by > > both fsvq->lock and fpq->lock for processing both virtqueue and > > fpq->processing_list, however, it is fine for them to be protected > > separately. > > > > Also since %req has been removed from fpq->processing_list, no one except > > request_wait_answer() is looking at this %req and request_wait_answer() > > waits only on FINISH flag, it's OK to remove fpq->lock after %req is > > dropped from the list. > > > > Signed-off-by: Liu Bo <[email protected]> > > --- > > fs/fuse/virtio_fs.c | 13 ++++++------- > > 1 file changed, 6 insertions(+), 7 deletions(-) > > > > diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c > > index 9b3f2e9..d88bb6c 100644 > > --- a/fs/fuse/virtio_fs.c > > +++ b/fs/fuse/virtio_fs.c > > @@ -347,21 +347,22 @@ static void virtio_fs_requests_done_work(struct > > work_struct *work) > > > > /* Collect completed requests off the virtqueue */ > > spin_lock(&fsvq->lock); > > - /* grab fpq->lock as req is on fpq->processing list */ > > - spin_lock(&fpq->lock); > > do { > > unsigned len; > > > > virtqueue_disable_cb(vq); > > > > while ((req = virtqueue_get_buf(vq, &len)) != NULL) { > > + /* grab fpq->lock as req is on fpq->processing list */ > > + spin_lock(&fpq->lock); > > + > > /* If !connected, req is freed by fuse_abort_conn. */ > > - if (fpq->connected) { > > + if (fpq->connected) > > list_move_tail(&req->list, &reqs); > > - } > > + > > + spin_unlock(&fpq->lock); > > } > > } while (!virtqueue_enable_cb(vq) && likely(!virtqueue_is_broken(vq))); > > - spin_unlock(&fpq->lock); > > spin_unlock(&fsvq->lock); > > > > /* End requests */ > > @@ -373,10 +374,8 @@ static void virtio_fs_requests_done_work(struct > > work_struct *work) > > > > /* TODO zeroing? */ > > > > - spin_lock(&fpq->lock); > > clear_bit(FR_SENT, &req->flags); > > list_del_init(&req->list); > > - spin_unlock(&fpq->lock); > > > > fuse_request_end(fc, req); > > } > >
