From: Ming Lei <ming.lei@xxxxxxxxxx> [ Upstream commit fa8e442e832a3647cdd90f3e606c473a51bc1b26 ] Most of control command handlers may sleep, so return -EAGAIN in case of IO_URING_F_NONBLOCK to defer the handling into io wq context. Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Reported-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230104133235.836536-1-ming.lei@xxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/block/ublk_drv.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 31a8715d3a4d..ebb5c846d826 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1718,6 +1718,9 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; int ret = -EINVAL; + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + ublk_ctrl_cmd_dump(cmd); if (!(issue_flags & IO_URING_F_SQE128)) -- 2.35.1