Re: [Virtio-fs] [PATCH 2/3] Do not dispatch forget requests once queue is disconnected

[Tao Peng]

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

Keep track of virtiofs queue status and once queue is disconnected do
not dispatch any more forget reuqests. Queue is disconnected once unmount
request comes in.

Reviewed-and-tested-by: Peng Tao <tao.p...@linux.alibaba.com>

Signed-off-by: Vivek Goyal <vgo...@redhat.com>
---
  fs/fuse/virtio_fs.c | 25 +++++++++++++++++++------
  1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index cbda7ebd5bf9..737e92cdc5ed 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -31,6 +31,7 @@ struct virtio_fs_vq {
        struct list_head queued_reqs;
        struct delayed_work dispatch_work;
        struct fuse_dev *fud;
+       bool connected;
        char name[24];
  } ____cacheline_aligned_in_smp;

@@ -215,6 +216,12 @@ static void virtio_fs_hiprio_dispatch_work(struct work_struct *work)

                }

list_del(&forget->list);

+               if (!fsvq->connected) {
+                       spin_unlock(&fsvq->lock);
+                       kfree(forget);
+                       continue;
+               }
+
                sg_init_one(&sg, forget, sizeof(*forget));

/* Enqueue the request */

@@ -425,9 +432,10 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev,
        if (ret < 0)
                goto out;

- for (i = 0; i < fs->nvqs; i++)

+       for (i = 0; i < fs->nvqs; i++) {
                fs->vqs[i].vq = vqs[i];
-
+               fs->vqs[i].connected = true;
+       }
  out:
        kfree(names);
        kfree(callbacks);
@@ -1071,11 +1079,16 @@ static int virtio_fs_fill_super(struct super_block *sb, 
void *data,
  static void virtio_kill_sb(struct super_block *sb)
  {
        struct fuse_conn *fc = get_fuse_conn_super(sb);
+       struct virtio_fs *vfs = fc->iq.priv;
+       struct virtio_fs_vq *fsvq = &vfs->vqs[VQ_HIPRIO];
+
+       /* Stop forget queue. Soon destroy will be sent */
+       spin_lock(&fsvq->lock);
+       fsvq->connected = false;
+       spin_unlock(&fsvq->lock);
+
        fuse_kill_sb_anon(sb);
-       if (fc) {
-               struct virtio_fs *vfs = fc->iq.priv;
-               virtio_fs_free_devs(vfs);
-       }
+       virtio_fs_free_devs(vfs);
  }

static struct dentry *virtio_fs_mount(struct file_system_type *fs_type,