io_uring: add generic callback_head helpers
We already have helpers to run/add callback_head but taking ctx and
working with ctx->exit_task_work. Extract generic versions of them
implemented in terms of struct callback_head, it will be used later.
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 70ceb8e..5c2de43 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1929,17 +1929,44 @@ static int io_req_task_work_add(struct io_kiocb *req)
return ret;
}
+static bool io_run_task_work_head(struct callback_head **work_head)
+{
+ struct callback_head *work, *next;
+ bool executed = false;
+
+ do {
+ work = xchg(work_head, NULL);
+ if (!work)
+ break;
+
+ do {
+ next = work->next;
+ work->func(work);
+ work = next;
+ cond_resched();
+ } while (work);
+ executed = true;
+ } while (1);
+
+ return executed;
+}
+
+static void io_task_work_add_head(struct callback_head **work_head,
+ struct callback_head *task_work)
+{
+ struct callback_head *head;
+
+ do {
+ head = READ_ONCE(*work_head);
+ task_work->next = head;
+ } while (cmpxchg(work_head, head, task_work) != head);
+}
+
static void io_req_task_work_add_fallback(struct io_kiocb *req,
task_work_func_t cb)
{
- struct io_ring_ctx *ctx = req->ctx;
- struct callback_head *head;
-
init_task_work(&req->task_work, cb);
- do {
- head = READ_ONCE(ctx->exit_task_work);
- req->task_work.next = head;
- } while (cmpxchg(&ctx->exit_task_work, head, &req->task_work) != head);
+ io_task_work_add_head(&req->ctx->exit_task_work, &req->task_work);
}
static void __io_req_task_cancel(struct io_kiocb *req, int error)
@@ -8471,26 +8498,9 @@ static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
return -EINVAL;
}
-static bool io_run_ctx_fallback(struct io_ring_ctx *ctx)
+static inline bool io_run_ctx_fallback(struct io_ring_ctx *ctx)
{
- struct callback_head *work, *next;
- bool executed = false;
-
- do {
- work = xchg(&ctx->exit_task_work, NULL);
- if (!work)
- break;
-
- do {
- next = work->next;
- work->func(work);
- work = next;
- cond_resched();
- } while (work);
- executed = true;
- } while (1);
-
- return executed;
+ return io_run_task_work_head(&ctx->exit_task_work);
}
struct io_tctx_exit {
