On 3/17/24 8:23 PM, Ming Lei wrote: > On Mon, Mar 18, 2024 at 12:41:47AM +0000, Pavel Begunkov wrote: >> !IO_URING_F_UNLOCKED does not translate to availability of the deferred >> completion infra, IO_URING_F_COMPLETE_DEFER does, that what we should >> pass and look for to use io_req_complete_defer() and other variants. >> >> Luckily, it's not a real problem as two wrongs actually made it right, >> at least as far as io_uring_cmd_work() goes. >> >> Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> >> Link: https://lore.kernel.org/r/eb08e72e837106963bc7bc7dccfd93d646cc7f36.1710514702.git.asml.silence@xxxxxxxxx >> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> >> --- >> io_uring/uring_cmd.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c >> index f197e8c22965..ec38a8d4836d 100644 >> --- a/io_uring/uring_cmd.c >> +++ b/io_uring/uring_cmd.c >> @@ -56,7 +56,11 @@ EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); >> static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts) >> { >> struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); >> - unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED; >> + unsigned issue_flags = IO_URING_F_UNLOCKED; >> + >> + /* locked task_work executor checks the deffered list completion */ >> + if (ts->locked) >> + issue_flags = IO_URING_F_COMPLETE_DEFER; >> >> ioucmd->task_work_cb(ioucmd, issue_flags); >> } >> @@ -100,7 +104,9 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2, >> if (req->ctx->flags & IORING_SETUP_IOPOLL) { >> /* order with io_iopoll_req_issued() checking ->iopoll_complete */ >> smp_store_release(&req->iopoll_completed, 1); >> - } else if (!(issue_flags & IO_URING_F_UNLOCKED)) { >> + } else if (issue_flags & IO_URING_F_COMPLETE_DEFER) { >> + if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED)) >> + return; >> io_req_complete_defer(req); >> } else { >> req->io_task_work.func = io_req_task_complete; > > 'git-bisect' shows the reported warning starts from this patch. That does make sense, as probably: + /* locked task_work executor checks the deffered list completion */ + if (ts->locked) + issue_flags = IO_URING_F_COMPLETE_DEFER; this assumption isn't true, and that would mess with the task management (which is in your oops). -- Jens Axboe
