io_uring: safer fallback_work free

Add extra wq flushing for fallback_work, that's not necessary but safer
if invariants of io_fallback_req_func() change.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/24179419d6748516299600bc914f50b9e0b02275.1633532552.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 7759fabf9ae017b1cafbdf3d5d054b782af2b2b6..90bef813556e352674df63ab29c58288cad3bb96 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1262,7 +1262,6 @@ static __cold void io_fallback_req_func(struct work_struct *work)
                mutex_unlock(&ctx->uring_lock);
        }
        percpu_ref_put(&ctx->refs);
-
 }
 
 static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
@@ -9212,6 +9211,7 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
        if (ctx->rsrc_backup_node)
                io_rsrc_node_destroy(ctx->rsrc_backup_node);
        flush_delayed_work(&ctx->rsrc_put_work);
+       flush_delayed_work(&ctx->fallback_work);
 
        WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
        WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));