On Wed, 29 Nov 2023 at 10:43, Zhao Chen <winters.zc@xxxxxxxxxxxx> wrote:
>
> From: Peng Tao <bergwolf@xxxxxxxxxxxx>
>
> When a FUSE daemon panic and failover, we aim to minimize the impact on
> applications by reusing the existing FUSE connection. During this
> process, another daemon is employed to preserve the FUSE connection's file
> descriptor.
>
> However, it is possible for some inflight requests to be lost and never
> returned. As a result, applications awaiting replies would become stuck
> forever. To address this, we can resend these pending requests to the
> FUSE daemon, which is done by fuse_resend_pqueue(), ensuring they are
> properly processed again.
>
> Signed-off-by: Peng Tao <bergwolf@xxxxxxxxxxxx>
> Signed-off-by: Zhao Chen <winters.zc@xxxxxxxxxxxx>
> ---
> fs/fuse/control.c | 20 ++++++++++++++++
> fs/fuse/dev.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++
> fs/fuse/fuse_i.h | 5 +++-
> 3 files changed, 83 insertions(+), 1 deletion(-)
>
> diff --git a/fs/fuse/control.c b/fs/fuse/control.c
> index 284a35006462..fd2258d701dd 100644
> --- a/fs/fuse/control.c
> +++ b/fs/fuse/control.c
> @@ -44,6 +44,18 @@ static ssize_t fuse_conn_abort_write(struct file *file, const char __user *buf,
> return count;
> }
>
> +static ssize_t fuse_conn_resend_write(struct file *file, const char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
> +
> + if (fc) {
> + fuse_resend_pqueue(fc);
> + fuse_conn_put(fc);
> + }
> + return count;
> +}
> +
How about triggering this with a notification (FUSE_NOTIFY_RESEND)?
Thanks,
Miklos
