Lock the ring with uring_lock in io_fallback_req_func(), which should
make it a bit safer and easier. With that we also don't need refs
pinning as io_ring_exit_work() will wait until uring_lock is freed.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
io_uring/io_uring.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 1b72ff558c17..e690c884dc95 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -245,17 +245,15 @@ static __cold void io_fallback_req_func(struct work_struct *work)
fallback_work.work);
struct llist_node *node = llist_del_all(&ctx->fallback_llist);
struct io_kiocb *req, *tmp;
- bool locked = false;
+ bool locked = true;
- percpu_ref_get(&ctx->refs);
+ mutex_lock(&ctx->uring_lock);
llist_for_each_entry_safe(req, tmp, node, io_task_work.node)
req->io_task_work.func(req, &locked);
-
- if (locked) {
- io_submit_flush_completions(ctx);
- mutex_unlock(&ctx->uring_lock);
- }
- percpu_ref_put(&ctx->refs);
+ if (WARN_ON_ONCE(!locked))
+ return;
+ io_submit_flush_completions(ctx);
+ mutex_unlock(&ctx->uring_lock);
}
static int io_alloc_hash_table(struct io_hash_table *table, unsigned bits)
--
2.38.1
