fuse: Flush the io-uring bg queue from fuse_uring_flush_bg

From: Bernd Schubert <bschubert@ddn.com>

This is useful to have a unique API to flush background requests.
For example when the bg queue gets flushed before
the remaining of fuse_conn_destroy().

Signed-off-by: Bernd Schubert <bschubert@ddn.com>
---
 fs/fuse/dev.c         |    2 ++
 fs/fuse/dev_uring.c   |    3 +++
 fs/fuse/dev_uring_i.h |   10 +++++++---
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 5387e4239d6a..3f5f168cc28a 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -426,6 +426,8 @@ static void flush_bg_queue(struct fuse_conn *fc)
 		fc->active_background++;
 		fuse_send_one(fiq, req);
 	}
+
+	fuse_uring_flush_bg(fc);
 }
 
 /*
diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
index eca457d1005e..acf11eadbf3b 100644
--- a/fs/fuse/dev_uring.c
+++ b/fs/fuse/dev_uring.c
@@ -123,6 +123,9 @@ void fuse_uring_flush_bg(struct fuse_conn *fc)
 	struct fuse_ring_queue *queue;
 	struct fuse_ring *ring = fc->ring;
 
+	if (!ring)
+		return;
+
 	for (qid = 0; qid < ring->nr_queues; qid++) {
 		queue = READ_ONCE(ring->queues[qid]);
 		if (!queue)
diff --git a/fs/fuse/dev_uring_i.h b/fs/fuse/dev_uring_i.h
index 55f52508de3c..fca2184e8d94 100644
--- a/fs/fuse/dev_uring_i.h
+++ b/fs/fuse/dev_uring_i.h
@@ -152,10 +152,10 @@ static inline void fuse_uring_abort(struct fuse_conn *fc)
 	if (ring == NULL)
 		return;
 
-	if (atomic_read(&ring->queue_refs) > 0) {
-		fuse_uring_flush_bg(fc);
+	/* Assumes bg queues were already flushed before */
+
+	if (atomic_read(&ring->queue_refs) > 0)
 		fuse_uring_stop_queues(ring);
-	}
 }
 
 static inline void fuse_uring_wait_stopped_queues(struct fuse_conn *fc)
@@ -206,6 +206,10 @@ static inline bool fuse_uring_request_expired(struct fuse_conn *fc)
 	return false;
 }
 
+static inline void fuse_uring_flush_bg(struct fuse_conn *fc)
+{
+}
+
 #endif /* CONFIG_FUSE_IO_URING */
 
 #endif /* _FS_FUSE_DEV_URING_I_H */