Re: [Virtio-fs] [PATCH 3/3] virtio-fs: Waiting for pending forget requests to finish

[Peng Tao]

On 2019/6/1 02:57, Vivek Goyal wrote:

Keep a track of pending forget requests and wait for these to finish
during ->kill_sb()

Signed-off-by: Vivek Goyal <vgo...@redhat.com>
---
  fs/fuse/virtio_fs.c | 38 +++++++++++++++++++++++++++++++++++++-
  1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 737e92cdc5ed..abdb58285805 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -32,6 +32,7 @@ struct virtio_fs_vq {
        struct delayed_work dispatch_work;
        struct fuse_dev *fud;
        bool connected;
+       long in_flight;
        char name[24];
  } ____cacheline_aligned_in_smp;

@@ -183,8 +184,10 @@ static void virtio_fs_hiprio_done_work(struct work_struct *work) virtqueue_disable_cb(vq); - while ((req = virtqueue_get_buf(vq, &len)) != NULL)

+               while ((req = virtqueue_get_buf(vq, &len)) != NULL) {
                        kfree(req);
+                       fsvq->in_flight--;
+               }
        } while (!virtqueue_enable_cb(vq) && likely(!virtqueue_is_broken(vq)));
        spin_unlock(&fsvq->lock);
  }
@@ -244,6 +247,7 @@ static void virtio_fs_hiprio_dispatch_work(struct 
work_struct *work)
                        return;
                }

+ fsvq->in_flight++;

                notify = virtqueue_kick_prepare(vq);
                spin_unlock(&fsvq->lock);

@@ -753,6 +757,7 @@ __releases(fiq->waitq.lock)

                goto out;
        }

+ fsvq->in_flight++;

        notify = virtqueue_kick_prepare(vq);

spin_unlock(&fsvq->lock);

@@ -982,6 +987,36 @@ __releases(fiq->waitq.lock)
        }
  }

+static void virtio_fs_flush_hiprio_queue(struct virtio_fs_vq *fsvq)

+{
+       struct virtio_fs_forget *forget;
+
+       WARN_ON(fsvq->in_flight < 0);
+
+       /* Go through pending forget reuests and free them */
+       spin_lock(&fsvq->lock);
+       while(1) {
+               forget = list_first_entry_or_null(&fsvq->queued_reqs,
+                                       struct virtio_fs_forget, list);
+               if (!forget)
+                       break;

missing list_del()?

Cheers,
Tao