[PATCH 3/5] io_uring: Convert to use setup_thread_fn callout

[Mike Christie <michael.christie@oracle.com>]

This converts io_uring to use the setup_thread_fn callout so it can set
the task's name during copy_process. It then doesn't need the temp buffer
and will work like kthread and vhost.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 io_uring/io-wq.c  | 11 +++++++----
 io_uring/sqpoll.c | 13 +++++++++----
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index 455df0c0deb5..4981bfd5581f 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -617,13 +617,9 @@ static int io_wqe_worker(void *data)
 	struct io_wqe *wqe = worker->wqe;
 	struct io_wq *wq = wqe->wq;
 	bool last_timeout = false;
-	char buf[TASK_COMM_LEN];
 
 	worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
 
-	snprintf(buf, sizeof(buf), "iou-wrk-%d", wq->task->pid);
-	set_task_comm(current, buf);
-
 	while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
 		long ret;
 
@@ -739,8 +735,15 @@ static inline bool io_should_retry_thread(long err)
 	}
 }
 
+static int io_wqe_setup_thread(struct task_struct *tsk, void *data)
+{
+	snprintf(tsk->comm, TASK_COMM_LEN, "iou-wrk-%d", tsk->pid);
+	return 0;
+}
+
 static struct kernel_clone_fns io_wqe_clone_fns = {
 	.thread_fn	= io_wqe_worker,
+	.setup_thread_fn = io_wqe_setup_thread,
 };
 
 static void create_worker_cont(struct callback_head *cb)
diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c
index 8d60b9775798..373067a714dc 100644
--- a/io_uring/sqpoll.c
+++ b/io_uring/sqpoll.c
@@ -223,12 +223,8 @@ static int io_sq_thread(void *data)
 	struct io_sq_data *sqd = data;
 	struct io_ring_ctx *ctx;
 	unsigned long timeout = 0;
-	char buf[TASK_COMM_LEN];
 	DEFINE_WAIT(wait);
 
-	snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid);
-	set_task_comm(current, buf);
-
 	if (sqd->sq_cpu != -1)
 		set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
 	else
@@ -312,8 +308,17 @@ static int io_sq_thread(void *data)
 	do_exit(0);
 }
 
+static int io_sq_setup_thread(struct task_struct *tsk, void *data)
+{
+	struct io_sq_data *sqd = data;
+
+	snprintf(tsk->comm, TASK_COMM_LEN, "iou-sqp-%d", sqd->task_pid);
+	return 0;
+}
+
 static struct kernel_clone_fns io_sq_clone_fns = {
 	.thread_fn	= io_sq_thread,
+	.setup_thread_fn = io_sq_setup_thread,
 };
 
 int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
-- 
2.25.1