io_uring: refactor tctx_task_work

Merge almost identical sections of tctx_task_work(), this will make code
modifications later easier and also inlines handle_tw_list().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d06592d91e3e7559e7a4dbb8907d110863008dc7.1674484266.git.asml.silence@gmail.com
[axboe: fold in setting count to zero patch from Tom Rix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 106cba919023f751b288312ecdbe1300164751f9..55101013f3ee84a3fd9ac8e0858e6a050f34ca79 100644 (file)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1166,7 +1166,7 @@ static unsigned int handle_tw_list(struct llist_node *node,
 {
        unsigned int count = 0;
 
-       while (node != last) {
+       while (node && node != last) {
                struct llist_node *next = node->next;
                struct io_kiocb *req = container_of(node, struct io_kiocb,
                                                    io_task_work.node);
@@ -1226,23 +1226,20 @@ void tctx_task_work(struct callback_head *cb)
                                                  task_work);
        struct llist_node fake = {};
        struct llist_node *node;
-       unsigned int loops = 1;
-       unsigned int count;
+       unsigned int loops = 0;
+       unsigned int count = 0;
 
        if (unlikely(current->flags & PF_EXITING)) {
                io_fallback_tw(tctx);
                return;
        }
 
-       node = io_llist_xchg(&tctx->task_list, &fake);
-       count = handle_tw_list(node, &ctx, &uring_locked, NULL);
-       node = io_llist_cmpxchg(&tctx->task_list, &fake, NULL);
-       while (node != &fake) {
+       do {
                loops++;
                node = io_llist_xchg(&tctx->task_list, &fake);
                count += handle_tw_list(node, &ctx, &uring_locked, &fake);
                node = io_llist_cmpxchg(&tctx->task_list, &fake, NULL);
-       }
+       } while (node != &fake);
 
        ctx_flush_and_put(ctx, &uring_locked);