fuse-over-io-uring needs an implicit device clone, which is done per
queue to avoid hanging "umount" when daemon side is already terminated.
Reason is that fuse_dev_release() is not called when there are queued
(waiting) io_uring commands.
Solution is the implicit device clone and an exception in fuse_dev_release
for uring devices to abort the connection when only uring device
are left.
Signed-off-by: Bernd Schubert <bschubert@xxxxxxx>
---
fs/fuse/dev.c | 32 ++++++++++++++++++++++++++++++--
fs/fuse/dev_uring_i.h | 13 +++++++++++++
2 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 78c05516da7f..cd5dc6ae9272 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -2257,6 +2257,8 @@ int fuse_dev_release(struct inode *inode, struct file *file)
struct fuse_pqueue *fpq = &fud->pq;
LIST_HEAD(to_end);
unsigned int i;
+ int dev_cnt;
+ bool abort_conn = false;
spin_lock(&fpq->lock);
WARN_ON(!list_empty(&fpq->io));
@@ -2266,8 +2268,34 @@ int fuse_dev_release(struct inode *inode, struct file *file)
fuse_dev_end_requests(&to_end);
- /* Are we the last open device? */
- if (atomic_dec_and_test(&fc->dev_count)) {
+ /* Are we the last open device? */
+ dev_cnt = atomic_dec_return(&fc->dev_count);
+ if (dev_cnt == 0)
+ abort_conn = true;
+
+ /*
+ * Or is this with io_uring and only ring devices left?
+ * These devices will not receive a ->release() as long as
+ * there are io_uring_cmd's waiting and not completed
+ * with io_uring_cmd_done yet
+ */
+ if (fuse_uring_configured(fc)) {
+ struct fuse_dev *list_dev;
+ bool all_uring = true;
+
+ spin_lock(&fc->lock);
+ list_for_each_entry(list_dev, &fc->devices, entry) {
+ if (list_dev == fud)
+ continue;
+ if (!list_dev->uring_dev)
+ all_uring = false;
+ }
+ spin_unlock(&fc->lock);
+ if (all_uring)
+ abort_conn = true;
+ }
+
+ if (abort_conn) {
WARN_ON(fc->iq.fasync != NULL);
fuse_abort_conn(fc);
}
diff --git a/fs/fuse/dev_uring_i.h b/fs/fuse/dev_uring_i.h
index 7a2f540d3ea5..114e9c008013 100644
--- a/fs/fuse/dev_uring_i.h
+++ b/fs/fuse/dev_uring_i.h
@@ -261,6 +261,14 @@ fuse_uring_get_queue(struct fuse_ring *ring, int qid)
return (struct fuse_ring_queue *)(ptr + qid * ring->queue_size);
}
+static inline bool fuse_uring_configured(struct fuse_conn *fc)
+{
+ if (READ_ONCE(fc->ring) != NULL && fc->ring->configured)
+ return true;
+
+ return false;
+}
+
#else /* CONFIG_FUSE_IO_URING */
struct fuse_ring;
@@ -274,6 +282,11 @@ static inline void fuse_uring_conn_destruct(struct fuse_conn *fc)
{
}
+static inline bool fuse_uring_configured(struct fuse_conn *fc)
+{
+ return false;
+}
+
#endif /* CONFIG_FUSE_IO_URING */
#endif /* _FS_FUSE_DEV_URING_I_H */
--
2.40.1
