io_uring: fix clear IORING_SETUP_R_DISABLED in wrong function

stable inclusion
from stable-5.10.51
commit 090588059c30ef1b49b82da96bfaead8f430c48e
bugzilla: 175263 https://gitee.com/openeuler/kernel/issues/I4DT6F

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=090588059c30ef1b49b82da96bfaead8f430c48e

--------------------------------

In commit 3ebba796 ("io_uring: ensure that SQPOLL thread is started for exit"),
the IORING_SETUP_R_DISABLED is cleared in io_sq_offload_start(), but when backport
it to stable-5.10, IORING_SETUP_R_DISABLED is cleared in __io_req_task_submit(),
move clearing IORING_SETUP_R_DISABLED to io_sq_offload_start() to fix this.

Fixes: 6cae8095490ca ("io_uring: ensure that SQPOLL thread is started for exit")
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/io_uring.c

@@ -2087,7 +2087,6 @@ static void __io_req_task_submit(struct io_kiocb *req)
 		__io_req_task_cancel(req, -EFAULT);
 	mutex_unlock(&ctx->uring_lock);
 
-	ctx->flags &= ~IORING_SETUP_R_DISABLED;
 	if (ctx->flags & IORING_SETUP_SQPOLL)
 		io_sq_thread_drop_mm();
 }
@@ -7992,6 +7991,7 @@ static void io_sq_offload_start(struct io_ring_ctx *ctx)
 {
 	struct io_sq_data *sqd = ctx->sq_data;
 
+	ctx->flags &= ~IORING_SETUP_R_DISABLED;
 	if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd->thread)
 		wake_up_process(sqd->thread);
 }