loop: aio inherit the ioprio of original request

Set cmd->iocb.ki_ioprio to the ioprio of loop device's request.
The purpose is to inherit the original request ioprio in the aio
flow.

Signed-off-by: Yunlong Xing <yunlong.xing@unisoc.com>
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250414030159.501180-1-yunlong.xing@unisoc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Yunlong Xing

drivers/block/loop.c

@@ -447,7 +447,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
 	cmd->iocb.ki_filp = file;
 	cmd->iocb.ki_complete = lo_rw_aio_complete;
 	cmd->iocb.ki_flags = IOCB_DIRECT;
-	cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0);
+	cmd->iocb.ki_ioprio = req_get_ioprio(rq);
 
 	if (rw == ITER_SOURCE)
 		ret = file->f_op->write_iter(&cmd->iocb, &iter);