On Tue, Oct 26, 2021 at 01:11:07AM +0300, Dmitry Osipenko wrote: > Hello, > > Recent -next has this new warning splat coming from MMC, please take a look. > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 525 at kernel/sched/core.c:9477 __might_sleep+0x65/0x68 > do not call blocking ops when !TASK_RUNNING; state=2 set at [<4316eb02>] prepare_to_wait+0x2e/0xb8 > Modules linked in: > CPU: 0 PID: 525 Comm: Xorg Tainted: G W 5.15.0-rc6-next-20211025-00226-g89ccd6948ec3 #5 > Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) > (unwind_backtrace) from [<c01089f9>] (show_stack+0x11/0x14) > (show_stack) from [<c0afacb9>] (dump_stack_lvl+0x2b/0x34) > (dump_stack_lvl) from [<c011f689>] (__warn+0xa1/0xe8) > (__warn) from [<c0af6729>] (warn_slowpath_fmt+0x65/0x7c) > (warn_slowpath_fmt) from [<c01421b9>] (__might_sleep+0x65/0x68) > (__might_sleep) from [<c07eb377>] (mmc_blk_rw_wait+0x2f/0x118) > (mmc_blk_rw_wait) from [<c07eba11>] (mmc_blk_mq_issue_rq+0x219/0x71c) > (mmc_blk_mq_issue_rq) from [<c07ec199>] (mmc_mq_queue_rq+0xf9/0x200) > (mmc_mq_queue_rq) from [<c04ad247>] (__blk_mq_try_issue_directly+0xcb/0x100) > (__blk_mq_try_issue_directly) from [<c04adb89>] (blk_mq_request_issue_directly+0x2d/0x48) > (blk_mq_request_issue_directly) from [<c04adcf3>] (blk_mq_flush_plug_list+0x14f/0x1f4) > (blk_mq_flush_plug_list) from [<c04a5313>] (blk_flush_plug+0x83/0xb8) > (blk_flush_plug) from [<c0b013cb>] (io_schedule+0x2b/0x3c) > (io_schedule) from [<c0b01a17>] (bit_wait_io+0xf/0x48) The following patch should fix the issue: diff --git a/block/blk-mq.c b/block/blk-mq.c index a71aeed7b987..bee9cb2a44cb 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2223,7 +2223,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) return; plug->rq_count = 0; - if (!plug->multiple_queues && !plug->has_elevator) { + if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) { blk_mq_plug_issue_direct(plug, from_schedule); if (rq_list_empty(plug->mq_list)) return; -- Ming