Re: [PATCH v9 15/17] fuse: {io-uring} Prevent mount point hang on fuse-server termination

[Pavel Begunkov <asml.silence@gmail.com>]

On 1/7/25 00:25, Bernd Schubert wrote:
> When the fuse-server terminates while the fuse-client or kernel
> still has queued URING_CMDs, these commands retain references
> to the struct file used by the fuse connection. This prevents
> fuse_dev_release() from being invoked, resulting in a hung mount
> point.

lgtm

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # io_uring

> 
> This patch addresses the issue by making queued URING_CMDs
> cancelable, allowing fuse_dev_release() to proceed as expected
> and preventing the mount point from hanging.
> 
> Signed-off-by: Bernd Schubert <bschubert@ddn.com>
> ---
>   fs/fuse/dev.c         |  2 ++
>   fs/fuse/dev_uring.c   | 71 ++++++++++++++++++++++++++++++++++++++++++++++++---
>   fs/fuse/dev_uring_i.h |  9 +++++++
>   3 files changed, 79 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index afafa960d4725d9b64b22f17bf09c846219396d6..1b593b23f7b8c319ec38c7e726dabf516965500e 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -599,8 +599,10 @@ static int fuse_request_queue_background(struct fuse_req *req)
>   	}
>   	__set_bit(FR_ISREPLY, &req->flags);
>   
> +#ifdef CONFIG_FUSE_IO_URING
>   	if (fuse_uring_ready(fc))
>   		return fuse_request_queue_background_uring(fc, req);
> +#endif


Looks like it should've been a part of some earlier commit.

>   
>   	spin_lock(&fc->bg_lock);
>   	if (likely(fc->connected)) {


-- 
Pavel Begunkov