io_uring: cancel more aggressively in exit_work

While io_ring_exit_work() is running new requests of all sorts may be
issued, so it should do a bit more to cancel them, otherwise they may
just get stuck. e.g. in io-wq, in poll lists, etc.

Signed-off-by: Pavel Begunkov <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 85de42c4243359129b046578b52c856133413288..5bccb235271f7fc60cffefadf5e71f0e0355c49b 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -992,6 +992,9 @@ enum io_mem_account {
        ACCT_PINNED,
 };
 
+static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
+                                           struct task_struct *task);
+
 static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node);
 static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
                        struct io_ring_ctx *ctx);
@@ -8675,7 +8678,7 @@ static void io_ring_exit_work(struct work_struct *work)
         * as nobody else will be looking for them.
         */
        do {
-               io_iopoll_try_reap_events(ctx);
+               __io_uring_cancel_task_requests(ctx, NULL);
        } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
        io_ring_ctx_free(ctx);
 }
@@ -8830,9 +8833,11 @@ static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
                enum io_wq_cancel cret;
                bool ret = false;
 
-               cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
-               if (cret != IO_WQ_CANCEL_NOTFOUND)
-                       ret = true;
+               if (ctx->io_wq) {
+                       cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb,
+                                              &cancel, true);
+                       ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
+               }
 
                /* SQPOLL thread does its own polling */
                if (!(ctx->flags & IORING_SETUP_SQPOLL)) {